Sample records for inhibit stimulated lipolysis

  1. Inhibition of hormone-stimulated lipolysis by clofibrate. A possible mechanism for its hypolipidemic action.

    PubMed Central

    D'Costa, M A; Angel, A

    1975-01-01

    The present study was undertaken to investigate the mechanism of the antilipolytic action of clofibrate (p-chlorophenoxyisobutyrate). Clofibrate, in the dose range of 10-80 mg/199 ml, inhibited the initial rate of norepinephrine-stimulated lipolysis 17-44 percent in isolated rat fat cells. At a dose corresponding to therapeutic levels in vivo (10 mg/100 ml) clofibrate also inhibited hormone-stimulated lipolysis by 20-30 percent in fragments of human subcutaneous fat. Inhibition of lipolysis by clofibrate occurred at all concentrations of norepinephrine and ACTH (0.02-0.1 mug/ml) but did not occur with equilipolytic concentrations of dibutyryl cyclic AMP, suggesting a proximal site of action on the lipolytic sequence. Clofibrate reduced by 60 percent (315plus or minus40 vs. 120plus or minus25 pmol/g lipid; meanplus or minusSEM) the norepinephrine-stimulated initial rise in cyclic AMP, measured 10 min after addition of hormone. Because the antilipolytic effect occurred in the presence of glucose and without altering cellular ATP levels, the reduction in intracellular cyclic AMP levels could not be attributed to uncoupling of oxidative metabolism or to secondary effects of free fatty acid accumulation. In the secondary effects of free fatty acid accumulation. In the presence of procaine-HC1, which blocks hormone-stimulated lipolysis without inhibiting cyclic AMP accumulation, addition of clofibrate prevented the hormone-stimulated rise in cyclic AMP. Clofibrate did not affect the activity of the low-Km 3',5'-cyclic AMP phosphodiesterase in norepinephrine-stimulated adipocytes. These data suggest that the antilipolytic effect of clofibrate is due to its suppression of cyclic AMP production by inhibition of adenylate cyclase. The drug's hypolipidemic action may in part be explained by its antilipolytic effect, which deprives the liver of free fatty acid substrate for lipoprotein synthesis. Images PMID:162783

  2. Propionic acid and butyric acid inhibit lipolysis and de novo lipogenesis and increase insulin-stimulated glucose uptake in primary rat adipocytes

    PubMed Central

    Heimann, Emilia; Nyman, Margareta; Degerman, Eva

    2014-01-01

    Fermentation of dietary fibers by colonic microbiota generates short-chain fatty acids (SCFAs), e.g., propionic acid and butyric acid, which have been described to have “anti-obesity properties” by ameliorating fasting glycaemia, body weight and insulin tolerance in animal models. In the present study, we therefore investigate if propionic acid and butyric acid have effects on lipolysis, de novo lipogenesis and glucose uptake in primary rat adipocytes. We show that both propionic acid and butyric acid inhibit isoproterenol- and adenosine deaminase-stimulated lipolysis as well as isoproterenol-stimulated lipolysis in the presence of a phosphodiesterase (PDE3) inhibitor. In addition, we show that propionic acid and butyric acid inhibit basal and insulin-stimulated de novo lipogenesis, which is associated with increased phosphorylation and thus inhibition of acetyl CoA carboxylase, a rate-limiting enzyme in fatty acid synthesis. Furthermore, we show that propionic acid and butyric acid increase insulin-stimulated glucose uptake. To conclude, our study shows that SCFAs have effects on fat storage and mobilization as well as glucose uptake in rat primary adipocytes. Thus, the SCFAs might contribute to healthier adipocytes and subsequently also to improved energy metabolism with for example less circulating free fatty acids, which is beneficial in the context of obesity and type 2 diabetes. PMID:26167409

  3. Propionic acid and butyric acid inhibit lipolysis and de novo lipogenesis and increase insulin-stimulated glucose uptake in primary rat adipocytes.

    PubMed

    Heimann, Emilia; Nyman, Margareta; Degerman, Eva

    2015-01-01

    Fermentation of dietary fibers by colonic microbiota generates short-chain fatty acids (SCFAs), e.g., propionic acid and butyric acid, which have been described to have "anti-obesity properties" by ameliorating fasting glycaemia, body weight and insulin tolerance in animal models. In the present study, we therefore investigate if propionic acid and butyric acid have effects on lipolysis, de novo lipogenesis and glucose uptake in primary rat adipocytes. We show that both propionic acid and butyric acid inhibit isoproterenol- and adenosine deaminase-stimulated lipolysis as well as isoproterenol-stimulated lipolysis in the presence of a phosphodiesterase (PDE3) inhibitor. In addition, we show that propionic acid and butyric acid inhibit basal and insulin-stimulated de novo lipogenesis, which is associated with increased phosphorylation and thus inhibition of acetyl CoA carboxylase, a rate-limiting enzyme in fatty acid synthesis. Furthermore, we show that propionic acid and butyric acid increase insulin-stimulated glucose uptake. To conclude, our study shows that SCFAs have effects on fat storage and mobilization as well as glucose uptake in rat primary adipocytes. Thus, the SCFAs might contribute to healthier adipocytes and subsequently also to improved energy metabolism with for example less circulating free fatty acids, which is beneficial in the context of obesity and type 2 diabetes.

  4. 18{beta}-Glycyrrhetinic acid inhibits adipogenic differentiation and stimulates lipolysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moon, Myung-Hee; Jeong, Jae-Kyo; Lee, You-Jin

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer 18{beta}-GA inhibits adipogenic differentiation in 3T3-L1 preadipocytes and stimulates lipolysis in differentiated adipocytes. Black-Right-Pointing-Pointer Anti-adipogenic effect of 18{beta}-GA is caused by down-regulation of PPAR{gamma} and inactivation of Akt signalling. Black-Right-Pointing-Pointer Lipolytic effect of 18{beta}-GA is mediated by up-regulation of HSL, ATGL and perilipin and activation of HSL. -- Abstract: 18{beta}-Glycyrrhetinic acid (18{beta}-GA) obtained from the herb liquorice has various pharmacological properties including anti-inflammatory and anti-bacterial activities. However, potential biological anti-obesity activities are unclear. In this study, novel biological activities of 18{beta}-GA in the adipogenesis of 3T3-L1 preadipocytes and in lipolysis of differentiated adipocytes were identified. Mouse 3T3-L1 cellsmore » were used as an in vitro model of adipogenesis and lipolysis, using a mixture of insulin/dexamethasone/3-isobutyl-1-methylxanthine (IBMX) to induce differentiation. The amount of lipid droplet accumulation was determined by an AdipoRed assay. The expression of several adipogenic transcription factors and enzymes was investigated using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. 18{beta}-GA dose-dependently (1-40 {mu}M) significantly decreased lipid accumulation in maturing preadipocytes. In 3T3-L1 preadipocytes, 10 {mu}M of 18{beta}-GA down-regulated the transcriptional levels of the peroxisome proliferator-activated receptor {gamma}, CCAAT/enhancer-binding protein {alpha} and adiponectin, which are markers of adipogenic differentiation via Akt phosphorylation. Also, in differentiated adipocytes, 18{beta}-GA increased the level of glycerol release and up-regulated the mRNA of hormone-sensitive lipase, adipose TG lipase and perilipin, as well as the phosphorylation of hormone-sensitive lipase at Serine 563. The results indicate that 18

  5. EPA-enriched phospholipids ameliorate cancer-associated cachexia mainly via inhibiting lipolysis.

    PubMed

    Du, Lei; Yang, Yu-Hong; Wang, Yu-Ming; Xue, Chang-Hu; Kurihara, Hideyuki; Takahashi, Koretaro

    2015-12-01

    Excessive loss of fat mass is considered as a key feature of body weight loss in cancer-associated cachexia (CAC). It affects the efficacy and tolerability of cancer therapy and reduces the quality and length of cancer patients' lives. The aim of the present study was to evaluate the effects of EPA-enriched phospholipids (EPA-PL) derived from starfish Asterias amurensis on cachectic weight loss in mice bearing S180 ascitic tumor, and TNF-α-stimulated lipolysis in 3T3-L1 adipocytes and to elucidate the possible mechanisms involved. Our findings revealed that oral administration of EPA-PL at 100 mg per kg body weight (BW) per day for 14 days prevented body weight loss in CAC mice by preserving the white adipose tissue (WAT) mass. We found that serum levels of nonesterified fatty acid (NEFA) and pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α) and interleukin (IL)-6 increased in CAC mice but decreased significantly after oral treatment of EPA-PL. In addition, EPA-PL treatment also suppressed the overexpression of several key lipolytic factors and raised the mRNA levels of some adipogenic factors in the WAT of CAC mice. Moreover, treatment of EPA-PL (200 and 400 μM) markedly inhibited TNF-α-stimulated lipolysis in adipocytes. Furthermore, the antilipolytic effects of EPA-PL were stimulated by the extracellular signal-regulated kinase 1/2 (ERK 1/2) inhibitor PD 98059 and blocked via the AMP-activated protein kinase (AMPK) inhibitor compound C and the phosphoinositide-3-kinase (PI3K) inhibitor LY 294002. Taken together, these data suggest that the dietary EPA-PL ameliorates CAC mainly via inhibiting lipolysis and at least in part for recovering the function of adipogenesis.

  6. Measurement of Basal and Forskolin-stimulated Lipolysis in Inguinal Adipose Fat Pads.

    PubMed

    Baskaran, Padmamalini; Thyagarajan, Baskaran

    2017-07-21

    Lipolysis is a process by which the lipid stored as triglycerides in adipose tissues are hydrolyzed into glycerol and fatty acids. This article describes the method for the measurement of basal and forskolin (FSK)-stimulated lipolysis in the inguinal fat pads isolated from wild type mice fed either normal chow diet (NCD), high fat diet (HFD) or a high fat diet containing 0.01% of capsaicin (CAP; transient receptor potential vanilloid subfamily 1 (TRPV1) agonist) for 32 weeks. The method described here for performing ex vivo lipolysis is adopted from Schweiger et al. 1 We present a detailed protocol for measuring glycerol levels by UV-Visible (UV/VIS) spectrophotometry. The method described here can be used to successfully isolate inguinal fat pads for lipolysis measurements to obtain consistent results. The protocol described for inguinal fat pads can readily be extended to measure lipolysis in other tissues.

  7. Butyrate and other short-chain fatty acids increase the rate of lipolysis in 3T3-L1 adipocytes

    PubMed Central

    Rumberger, John M.; Arch, Jonathan R.S.

    2014-01-01

    We determined the effect of butyrate and other short-chain fatty acids (SCFA) on rates of lipolysis in 3T3-L1 adipocytes. Prolonged treatment with butyrate (5 mM) increased the rate of lipolysis approximately 2–3-fold. Aminobutyric acid and acetate had little or no effect on lipolysis, however propionate stimulated lipolysis, suggesting that butyrate and propionate act through their shared activity as histone deacetylase (HDAC) inhibitors. Consistent with this, the HDAC inhibitor trichostatin A (1 µM) also stimulated lipolysis to a similar extent as did butyrate. Western blot data suggested that neither mitogen-activated protein kinase (MAPK) activation nor perilipin down-regulation are necessary for SCFA-induced lipolysis. Stimulation of lipolysis with butyrate and trichostatin A was glucose-dependent. Changes in AMP-activated protein kinase (AMPK) phosphorylation mediated by glucose were independent of changes in rates of lipolysis. The glycolytic inhibitor iodoacetate prevented both butyrate- and tumor necrosis factor-alpha-(TNF-α) mediated increases in rates of lipolysis indicating glucose metabolism is required. However, unlike TNF-α– , butyrate-stimulated lipolysis was not associated with increased lactate release or inhibited by activation of pyruvate dehydrogenase (PDH) with dichloroacetate. These data demonstrate an important relationship between lipolytic activity and reported HDAC inhibitory activity of butyrate, other short-chain fatty acids and trichostatin A. Given that HDAC inhibitors are presently being evaluated for the treatment of diabetes and other disorders, more work will be essential to determine if these effects on lipolysis are due to inhibition of HDAC. PMID:25320679

  8. Partial inhibition of adipose tissue lipolysis improves glucose metabolism and insulin sensitivity without alteration of fat mass.

    PubMed

    Girousse, Amandine; Tavernier, Geneviève; Valle, Carine; Moro, Cedric; Mejhert, Niklas; Dinel, Anne-Laure; Houssier, Marianne; Roussel, Balbine; Besse-Patin, Aurèle; Combes, Marion; Mir, Lucile; Monbrun, Laurent; Bézaire, Véronic; Prunet-Marcassus, Bénédicte; Waget, Aurélie; Vila, Isabelle; Caspar-Bauguil, Sylvie; Louche, Katie; Marques, Marie-Adeline; Mairal, Aline; Renoud, Marie-Laure; Galitzky, Jean; Holm, Cecilia; Mouisel, Etienne; Thalamas, Claire; Viguerie, Nathalie; Sulpice, Thierry; Burcelin, Rémy; Arner, Peter; Langin, Dominique

    2013-01-01

    When energy is needed, white adipose tissue (WAT) provides fatty acids (FAs) for use in peripheral tissues via stimulation of fat cell lipolysis. FAs have been postulated to play a critical role in the development of obesity-induced insulin resistance, a major risk factor for diabetes and cardiovascular disease. However, whether and how chronic inhibition of fat mobilization from WAT modulates insulin sensitivity remains elusive. Hormone-sensitive lipase (HSL) participates in the breakdown of WAT triacylglycerol into FAs. HSL haploinsufficiency and treatment with a HSL inhibitor resulted in improvement of insulin tolerance without impact on body weight, fat mass, and WAT inflammation in high-fat-diet-fed mice. In vivo palmitate turnover analysis revealed that blunted lipolytic capacity is associated with diminution in FA uptake and storage in peripheral tissues of obese HSL haploinsufficient mice. The reduction in FA turnover was accompanied by an improvement of glucose metabolism with a shift in respiratory quotient, increase of glucose uptake in WAT and skeletal muscle, and enhancement of de novo lipogenesis and insulin signalling in liver. In human adipocytes, HSL gene silencing led to improved insulin-stimulated glucose uptake, resulting in increased de novo lipogenesis and activation of cognate gene expression. In clinical studies, WAT lipolytic rate was positively and negatively correlated with indexes of insulin resistance and WAT de novo lipogenesis gene expression, respectively. In obese individuals, chronic inhibition of lipolysis resulted in induction of WAT de novo lipogenesis gene expression. Thus, reduction in WAT lipolysis reshapes FA fluxes without increase of fat mass and improves glucose metabolism through cell-autonomous induction of fat cell de novo lipogenesis, which contributes to improved insulin sensitivity.

  9. β-Adrenergic induction of lipolysis in hepatocytes is inhibited by ethanol exposure.

    PubMed

    Schott, Micah B; Rasineni, Karuna; Weller, Shaun G; Schulze, Ryan J; Sletten, Arthur C; Casey, Carol A; McNiven, Mark A

    2017-07-14

    In liver steatosis ( i.e. fatty liver), hepatocytes accumulate many large neutral lipid storage organelles known as lipid droplets (LDs). LDs are important in the maintenance of energy homeostasis, but the signaling mechanisms that stimulate LD metabolism in hepatocytes are poorly defined. In adipocytes, catecholamines target the β-adrenergic (β-AR)/cAMP pathway to activate cytosolic lipases and induce their recruitment to the LD surface. Therefore, the goal of this study was to determine whether hepatocytes, like adipocytes, also undergo cAMP-mediated lipolysis in response to β-AR stimulation. Using primary rat hepatocytes and human hepatoma cells, we found that treatment with the β-AR agent isoproterenol caused substantial LD loss via activation of cytosolic lipases adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). β-Adrenergic stimulation rapidly activated PKA, which led to the phosphorylation of ATGL and HSL and their recruitment to the LD surface. To test whether this β-AR-dependent lipolysis pathway was altered in a model of alcoholic fatty liver, primary hepatocytes from rats fed a 6-week EtOH-containing Lieber-DeCarli diet were treated with cAMP agonists. Compared with controls, EtOH-exposed hepatocytes showed a drastic inhibition in β-AR/cAMP-induced LD breakdown and the phosphorylation of PKA substrates, including HSL. This observation was supported in VA-13 cells, an EtOH-metabolizing human hepatoma cell line, which displayed marked defects in both PKA activation and isoproterenol-induced ATGL translocation to the LD periphery. In summary, these findings suggest that β-AR stimulation mobilizes cytosolic lipases for LD breakdown in hepatocytes, and perturbation of this pathway could be a major consequence of chronic EtOH insult leading to fatty liver.

  10. mTORC1 Inhibition via Rapamycin Promotes Triacylglycerol Lipolysis and Release of Free Fatty Acids in 3T3-L1 Adipocytes

    PubMed Central

    Soliman, Ghada A.; Acosta-Jaquez, Hugo A.; Fingar, Diane C.

    2017-01-01

    Signaling by mTOR complex 1 (mTORC1) promotes anabolic cellular processes in response to growth factors, nutrients, and hormonal cues. Numerous clinical trials employing the mTORC1 inhibitor rapamycin (aka sirolimus) to immuno-suppress patients following organ transplantation have documented the development of hypertriglyceridemia and elevated serum free fatty acids (FFA). We therefore investigated the cellular role of mTORC1 in control of triacylglycerol (TAG) metabolism using cultured murine 3T3-L1 adipocytes. We found that treatment of adipocytes with rapamycin reduced insulin-stimulated TAG storage ~50%. To determine whether rapamycin reduces TAG storage by upregulating lipolytic rate, we treated adipocytes in the absence and presence of rapamycin and isoproterenol, a β2-adrenergic agonist that activates the cAMP/protein kinase A (PKA) pathway to promote lipolysis. We found that rapamycin augmented isoproterenol-induced lipolysis without altering cAMP levels. Rapamycin enhanced the isoproterenol-stimulated phosphorylation of hormone sensitive lipase (HSL) on Ser-563 (a PKA site), but had no effect on the phosphorylation of HSL S565 (an AMPK site). Additionally, rapamycin did not affect the isoproterenol-mediated phosphorylation of perilipin, a protein that coats the lipid droplet to initiate lipolysis upon phosphorylation by PKA. These data demonstrate that inhibition of mTORC1 signaling synergizes with the β-adrenergic-cAMP/PKA pathway to augment phosphorylation of HSL to promote hormone-induced lipolysis. Moreover, they reveal a novel metabolic function for mTORC1; mTORC1 signaling suppresses lipolysis, thus augmenting TAG storage. PMID:21042876

  11. Phloretin and phlorizin promote lipolysis and inhibit inflammation in mouse 3T3-L1 cells and in macrophage-adipocyte co-cultures.

    PubMed

    Huang, Wen-Chung; Chang, Wei-Tien; Wu, Shu-Ju; Xu, Pei-Yin; Ting, Nai-Chun; Liou, Chian-Jiun

    2013-10-01

    Previous studies found that phloretin (PT) and phlorizin (PZ) could inhibit glucose transport, with PT being a better inhibitor of lipid peroxidation. This study aimed to evaluate the antiobesity effects of PT and PZ in 3T3-L1 cells and if they can modulate the relationship between adipocytes and macrophages. Differentiated 3T3-L1 cells were treated with PT or PZ. Subsequently, transcription factors of adipogenesis and lipolysis proteins were measured. In addition, RAW 264.7 macrophages treated with PT or PZ were cultured in differentiated media from 3T3-L1 cells to analyze inflammatory mediators and signaling pathways. PT significantly enhanced glycerol release and inhibited the adipogenesis-related transcription factors. PT also promoted phosphorylation of AMP-activated protein kinase and increased activity of adipose triglyceride lipase and hormone-sensitive lipase. PT suppressed the nuclear transcription factor kappa-B and mitogen-activated protein kinase pathways when RAW 264.7 cells were cultured in differentiated media from 3T3-L1 cells. PZ improved lipolysis and inhibited the macrophage inflammatory response less effectively than PT. This study suggests that PT is more effective than PZ at increasing lipolysis in adipocytes. In addition, PT also suppresses inflammatory response in macrophage that is stimulated by differentiated media from 3T3-L1 cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Bone marrow adipocytes resist lipolysis and remodeling in response to β-adrenergic stimulation.

    PubMed

    Scheller, Erica L; Khandaker, Shaima; Learman, Brian S; Cawthorn, William P; Anderson, Lindsay M; Pham, H A; Robles, Hero; Wang, Zhaohua; Li, Ziru; Parlee, Sebastian D; Simon, Becky R; Mori, Hiroyuki; Bree, Adam J; Craft, Clarissa S; MacDougald, Ormond A

    2018-01-26

    Bone marrow adipose tissue (BMAT) is preserved or increased in states of caloric restriction. Similarly, we found that BMAT in the tail vertebrae, but not the red marrow in the tibia, resists loss of neutral lipid with acute, 48-hour fasting in rats. The mechanisms underlying this phenomenon and its seemingly distinct regulation from peripheral white adipose tissue (WAT) remain unknown. To test the role of β-adrenergic stimulation, a major regulator of adipose tissue lipolysis, we examined the responses of BMAT to β-adrenergic agonists. Relative to inguinal WAT, BMAT had reduced phosphorylation of hormone sensitive lipase (HSL) after treatment with pan-β-adrenergic agonist isoproterenol. Phosphorylation of HSL in response to β3-adrenergic agonist CL316,243 was decreased by an additional ~90% (distal tibia BMAT) or could not be detected (tail vertebrae). Ex vivo, adrenergic stimulation of lipolysis in purified BMAT adipocytes was also substantially less than iWAT adipocytes and had site-specific properties. Specifically, regulated bone marrow adipocytes (rBMAs) from proximal tibia and femur underwent lipolysis in response to both CL316,243 and forskolin, while constitutive BMAs from the tail responded only to forskolin. This occurred independently of changes in gene expression of β-adrenergic receptors, which were similar between adipocytes from iWAT and BMAT, and could not be explained by defective coupling of β-adrenergic receptors to lipolytic machinery through caveolin 1. Specifically, we found that whereas caveolin 1 was necessary to mediate maximal stimulation of lipolysis in iWAT, overexpression of caveolin 1 was insufficient to rescue impaired BMAT signaling. Lastly, we tested the ability of BMAT to respond to 72-hour treatment with CL316,243 in vivo. This was sufficient to cause beiging of iWAT adipocytes and a decrease in iWAT adipocyte cell size. By contrast, adipocyte size in the tail BMAT and distal tibia remained unchanged. However, within the

  13. Caveolin-1 regulates lipid droplet metabolism in endothelial cells via autocrine prostacyclin-stimulated, cAMP-mediated lipolysis.

    PubMed

    Kuo, Andrew; Lee, Monica Y; Yang, Kui; Gross, Richard W; Sessa, William C

    2018-01-19

    Lipid droplets (LD) are dynamic organelles involved in intracellular lipid metabolism in almost all eukaryotic cells, and LD-associated proteins tightly regulate their dynamics. One LD coat protein is caveolin-1 (Cav-1), an essential component for caveola assembly in highly differentiated cells, including adipocytes, smooth muscle cells, and endothelial cells (EC). However, the role of Cav-1 in LD dynamics is unclear. Here we report that EC lacking Cav-1 exhibit impaired LD formation. The decreased LD formation is due to enhanced lipolysis and not caused by reduced triglyceride synthesis or fatty acid uptake. Mechanistically, the absence of Cav-1 increased cAMP/PKA signaling in EC, as indicated by elevated phosphorylation of hormone-sensitive lipase and increased lipolysis. Unexpectedly, we also observed enhanced autocrine production of prostaglandin I 2 (PGI 2 , also called prostacyclin) in Cav-1 KO EC, and this PGI 2 increase appeared to stimulate cAMP/PKA pathways, contributing to the enhanced lipolysis in Cav-1 KO cells. Our results reveal an unanticipated role of Cav-1 in regulating lipolysis in non-adipose tissue, indicating that Cav-1 is required for LD metabolism in EC and that it regulates cAMP-dependent lipolysis in part via the autocrine production of PGI 2 .

  14. Rosmarinic acid suppresses adipogenesis, lipolysis in 3T3-L1 adipocytes, lipopolysaccharide-stimulated tumor necrosis factor-α secretion in macrophages, and inflammatory mediators in 3T3-L1 adipocytes

    PubMed Central

    Rui, Yehua; Tong, Lingxia; Cheng, Jinbo; Wang, Guiping; Qin, Liqiang; Wan, Zhongxiao

    2017-01-01

    ABSTRACT Background: Rosmarinic acid (RA) is a natural phenol carboxylic acid with many promising biological effects. It may be a suitable candidate for improving obesity-related adipose tissue dysfunction. Objective: We aimed to investigate the therapeutic use of RA as an anti-obesity agent by measuring its effects on adipogenesis, lipolysis, and messenger RNA (mRNA) expression of major adipokines in 3T3-L1 adipocytes; and its effects on lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) secretion in macrophages and inflammatory mediators in 3T3-L1 adipocytes incubated with macrophage-conditioned medium (MCM). Methods: 3T3-L1 preadipocytes were used to explore how RA affects adipogenesis, as well as the involvement of phosphorylated extracellular signal-regulated kinase-1/2 (p-ERK1/2) and mothers against decapentaplegic homolog 3 (p-Smad3). 3T3-L1 preadipocytes were also differentiated into mature adipocytes to explore how RA affects basal and isoproterenol- and forskolin-stimulated lipolysis; and how RA affects key adipokines’ mRNA expression. RAW 264.7 macrophages were stimulated with LPS in the absence or presence of RA to explore RA’s effects on TNF-α secretion. MCM was collected and 3T3-L1 adipocytes were incubated with MCM to explore RA’s effects on interleukin-6 (IL-6), IL-1β, monocyte chemoattractant protein-1 (MCP-1), and RANTES mRNA expression. Results: During the preadipocyte differentiation process, RA suppressed peroxisome proliferator-activated receptor-γ and CCAAT/enhancer binding protein-α, and activated p-ERK1/2 and p-Smad3; inhibition of adipogenesis by RA was partially restored following treatment with p-ERK1/2 and p-Smad3 inhibitors. In mature adipocytes, RA inhibited basal lipolysis; phosphodiesterase-3 inhibitor reversed this. RA also inhibited isoproterenol- and forskolin-stimulated glycerol and free fatty acid release, and the phosphorylation of hormone-sensitive lipase and perilipin. RA had no effects on leptin

  15. Lipid droplet meets a mitochondrial protein to regulate adipocyte lipolysis

    USDA-ARS?s Scientific Manuscript database

    In response to adrenergic stimulation, adipocytes undergo protein kinase A (PKA)-stimulated lipolysis. A key PKA target in this context is perilipin 1, a major regulator of lipolysis on lipid droplets (LDs). A study published in this issue of The EMBO Journal (Pidoux et al, 2011) identifies optic at...

  16. Conjugated linoleic acid supplementation caused reduction of perilipin1 and aberrant lipolysis in epididymal adipose tissue

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Demin; Li, Hongji; Zhou, Bo

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Conjugated linoleic acid supplementation suppresses perilipin1 in epididymal fat. Black-Right-Pointing-Pointer Conjugated linoleic acid inhibits promoter activity of perilipin1 in 3T3-L1 cells. Black-Right-Pointing-Pointer Conjugated linoleic acids elevate basal but blunt hormone-stimulated lipolysis. -- Abstract: Perilipin1, a coat protein of lipid droplet, plays a key role in adipocyte lipolysis and fat formation of adipose tissues. However, it is not clear how the expression of perilipin1 is affected in the decreased white adipose tissues (WAT) of mice treated with dietary supplement of conjugated linoleic acids (CLA). Here we obtained lipodystrophic mice by dietary administration of CLA which exhibited reduced epididymal (EPI)more » WAT, aberrant adipocytes and decreased expression of leptin in this tissue. We found both transcription and translation of perilipin1 was suppressed significantly in EPI WAT of CLA-treated mice compared to that of control mice. The gene expression of negative regulator tumor necrosis factor {alpha} (TNF{alpha}) and the positive regulator Peroxisome Proliferator-Activated Receptor-{gamma} (PPAR{gamma}) of perilipin1 was up-regulated and down-regulated, respectively. In cultured 3T3-L1 cells the promoter activity of perilipin1 was dramatically inhibited in the presence of CLA. Using ex vivo experiment we found that the basal lipolysis was elevated but the hormone-stimulated lipolysis blunted in adipose explants of CLA-treated mice compared to that of control mice, suggesting that the reduction of perilipin1 in white adipose tissues may at least in part contribute to CLA-mediated alternation of lipolysis of WAT.« less

  17. Branched Chain Amino Acids Cause Liver Injury in Obese/Diabetic Mice by Promoting Adipocyte Lipolysis and Inhibiting Hepatic Autophagy.

    PubMed

    Zhang, Fuyang; Zhao, Shihao; Yan, Wenjun; Xia, Yunlong; Chen, Xiyao; Wang, Wei; Zhang, Jinglong; Gao, Chao; Peng, Cheng; Yan, Feng; Zhao, Huishou; Lian, Kun; Lee, Yan; Zhang, Ling; Lau, Wayne Bond; Ma, Xinliang; Tao, Ling

    2016-11-01

    The Western meat-rich diet is both high in protein and fat. Although the hazardous effect of a high fat diet (HFD) upon liver structure and function is well recognized, whether the co-presence of high protein intake contributes to, or protects against, HF-induced hepatic injury remains unclear. Increased intake of branched chain amino acids (BCAA, essential amino acids compromising 20% of total protein intake) reduces body weight. However, elevated circulating BCAA is associated with non-alcoholic fatty liver disease and injury. The mechanisms responsible for this quandary remain unknown; the role of BCAA in HF-induced liver injury is unclear. Utilizing HFD or HFD+BCAA models, we demonstrated BCAA supplementation attenuated HFD-induced weight gain, decreased fat mass, activated mammalian target of rapamycin (mTOR), inhibited hepatic lipogenic enzymes, and reduced hepatic triglyceride content. However, BCAA caused significant hepatic damage in HFD mice, evidenced by exacerbated hepatic oxidative stress, increased hepatic apoptosis, and elevated circulation hepatic enzymes. Compared to solely HFD-fed animals, plasma levels of free fatty acids (FFA) in the HFD+BCAA group are significantly further increased, due largely to AMPKα2-mediated adipocyte lipolysis. Lipolysis inhibition normalized plasma FFA levels, and improved insulin sensitivity. Surprisingly, blocking lipolysis failed to abolish BCAA-induced liver injury. Mechanistically, hepatic mTOR activation by BCAA inhibited lipid-induced hepatic autophagy, increased hepatic apoptosis, blocked hepatic FFA/triglyceride conversion, and increased hepatocyte susceptibility to FFA-mediated lipotoxicity. These data demonstrated that BCAA reduces HFD-induced body weight, at the expense of abnormal lipolysis and hyperlipidemia, causing hepatic lipotoxicity. Furthermore, BCAA directly exacerbate hepatic lipotoxicity by reducing lipogenesis and inhibiting autophagy in the hepatocyte. Copyright © 2016. Published by Elsevier

  18. On the suppression of plasma nonesterified fatty acids by insulin during enhanced intravascular lipolysis in humans.

    PubMed

    Carpentier, André C; Frisch, Frédérique; Cyr, Denis; Généreux, Philippe; Patterson, Bruce W; Giguère, Robert; Baillargeon, Jean-Patrice

    2005-11-01

    During the fasting state, insulin reduces nonesterified fatty acid (NEFA) appearance in the systemic circulation mostly by suppressing intracellular lipolysis in the adipose tissue. In the postprandial state, insulin may also control NEFA appearance through enhanced trapping into the adipose tissue of NEFA derived from intravascular triglyceride lipolysis. To determine the contribution of suppression of intracellular lipolysis in the modulation of plasma NEFA metabolism by insulin during enhanced intravascular triglyceride lipolysis, 10 healthy nonobese subjects underwent pancreatic clamps at fasting vs. high physiological insulin level with intravenous infusion of heparin plus Intralipid. Nicotinic acid was administered orally during the last 2 h of each 4-h clamp to inhibit intracellular lipolysis and assess insulin's effect on plasma NEFA metabolism independently of its effect on intracellular lipolysis. Stable isotope tracers of palmitate, acetate, and glycerol were used to assess plasma NEFA metabolism and total triglyceride lipolysis in each participant. The glycerol appearance rate was similar during fasting vs. high insulin level, but plasma NEFA levels were significantly lowered by insulin. Nicotinic acid significantly blunted the insulin-mediated suppression of plasma palmitate appearance and oxidation rates by approximately 60 and approximately 70%, respectively. In contrast, nicotinic acid did not affect the marked stimulation of palmitate clearance by insulin. Thus most of the insulin-mediated reduction of plasma NEFA appearance and oxidation can be explained by suppression of intracellular lipolysis during enhanced intravascular triglyceride lipolysis in healthy humans. Our results also suggest that insulin may affect plasma NEFA clearance independently of the suppression of intracellular lipolysis.

  19. Adipose triglyceride lipase protein abundance and translocation to the lipid droplet increase during leptin-induced lipolysis in bovine adipocytes.

    PubMed

    Koltes, D A; Spurlock, M E; Spurlock, D M

    2017-10-01

    Proper regulation of lipid metabolism is critical for preventing the development of metabolic diseases. It is clear that leptin plays a critical role in the regulation of energy homeostasis by regulating energy intake. However, leptin can also regulate energy homeostasis by inducing lipolysis in adipocytes, but it is unclear how the major lipases are involved in leptin-stimulated lipolysis. Therefore, the objectives of this study were to determine if (1) leptin acts directly to induce lipolysis in bovine adipocytes, (2) the potential lipases involved in leptin-induced lipolysis in bovine adipocytes, and (3) increases translocation of adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL) during leptin-stimulated lipolysis in bovine stromal vascular cell-derived adipocytes. As hypothesized, leptin induced a lipolytic response (P = 0.02) in isolated adipocytes which was accompanied by an increase in phosphorylation of signal transducer and activator of transcription (STAT)3 (P = 0.03), a well-documented secondary messenger of leptin, and ATGL protein abundance (P < 0.01). Protein abundance of STAT3, perilipin, HSL, and phosphorylation of HSL by PKA and AMPK were not altered during leptin-stimulated lipolysis (P > 0.05). Immunostaining techniques were employed to determine the location of HSL and ATGL. Both lipases translocated to the lipid droplet after 2 h of exposure to isoproterenol (P < 0.02). However, only ATGL was translocated to the lipid droplet during leptin-stimulated lipolysis (P = 0.04), indicating ATGL may be the active lipase in leptin-stimulated lipolysis. In summary, leptin stimulates lipolysis in bovine adipocytes. The lack of phosphorylated HSL and translocation of HSL to the lipid droplet during leptin-stimulated lipolysis suggest minimal activity by PKA. Interestingly, leptin-stimulated lipolysis is accompanied by an increase in ATGL protein abundance and translocation to the lipid droplet, indicating its involvement in leptin-stimulated

  20. Lipolysis Response to Endoplasmic Reticulum Stress in Adipose Cells*

    PubMed Central

    Deng, Jingna; Liu, Shangxin; Zou, Liangqiang; Xu, Chong; Geng, Bin; Xu, Guoheng

    2012-01-01

    In obesity and diabetes, adipocytes show significant endoplasmic reticulum (ER) stress, which triggers a series of responses. This study aimed to investigate the lipolysis response to ER stress in rat adipocytes. Thapsigargin, tunicamycin, and brefeldin A, which induce ER stress through different pathways, efficiently activated a time-dependent lipolytic reaction. The lipolytic effect of ER stress occurred with elevated cAMP production and protein kinase A (PKA) activity. Inhibition of PKA reduced PKA phosphosubstrates and attenuated the lipolysis. Although both ERK1/2 and JNK are activated during ER stress, lipolysis is partially suppressed by inhibiting ERK1/2 but not JNK and p38 MAPK and PKC. Thus, ER stress induces lipolysis by activating cAMP/PKA and ERK1/2. In the downstream lipolytic cascade, phosphorylation of lipid droplet-associated protein perilipin was significantly promoted during ER stress but attenuated on PKA inhibition. Furthermore, ER stress stimuli did not alter the levels of hormone-sensitive lipase and adipose triglyceride lipase but caused Ser-563 and Ser-660 phosphorylation of hormone-sensitive lipase and moderately elevated its translocation from the cytosol to lipid droplets. Accompanying these changes, total activity of cellular lipases was promoted to confer the lipolysis. These findings suggest a novel pathway of the lipolysis response to ER stress in adipocytes. This lipolytic activation may be an adaptive response that regulates energy homeostasis but with sustained ER stress challenge could contribute to lipotoxicity, dyslipidemia, and insulin resistance because of persistently accelerated free fatty acid efflux from adipocytes to the bloodstream and other tissues. PMID:22223650

  1. Artificial Sweeteners Stimulate Adipogenesis and Suppress Lipolysis Independently of Sweet Taste Receptors*

    PubMed Central

    Simon, Becky R.; Parlee, Sebastian D.; Learman, Brian S.; Mori, Hiroyuki; Scheller, Erica L.; Cawthorn, William P.; Ning, Xiaomin; Gallagher, Katherine; Tyrberg, Björn; Assadi-Porter, Fariba M.; Evans, Charles R.; MacDougald, Ormond A.

    2013-01-01

    G protein-coupled receptors mediate responses to a myriad of ligands, some of which regulate adipocyte differentiation and metabolism. The sweet taste receptors T1R2 and T1R3 are G protein-coupled receptors that function as carbohydrate sensors in taste buds, gut, and pancreas. Here we report that sweet taste receptors T1R2 and T1R3 are expressed throughout adipogenesis and in adipose tissues. Treatment of mouse and human precursor cells with artificial sweeteners, saccharin and acesulfame potassium, enhanced adipogenesis. Saccharin treatment of 3T3-L1 cells and primary mesenchymal stem cells rapidly stimulated phosphorylation of Akt and downstream targets with functions in adipogenesis such as cAMP-response element-binding protein and FOXO1; however, increased expression of peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α was not observed until relatively late in differentiation. Saccharin-stimulated Akt phosphorylation at Thr-308 occurred within 5 min, was phosphatidylinositol 3-kinase-dependent, and occurred in the presence of high concentrations of insulin and dexamethasone; phosphorylation of Ser-473 occurred more gradually. Surprisingly, neither saccharin-stimulated adipogenesis nor Thr-308 phosphorylation was dependent on expression of T1R2 and/or T1R3, although Ser-473 phosphorylation was impaired in T1R2/T1R3 double knock-out precursors. In mature adipocytes, artificial sweetener treatment suppressed lipolysis even in the presence of forskolin, and lipolytic responses were correlated with phosphorylation of hormone-sensitive lipase. Suppression of lipolysis by saccharin in adipocytes was also independent of T1R2 and T1R3. These results suggest that some artificial sweeteners have previously uncharacterized metabolic effects on adipocyte differentiation and metabolism and that effects of artificial sweeteners on adipose tissue biology may be largely independent of the classical sweet taste receptors, T1R2 and T1R3. PMID

  2. Artificial sweeteners stimulate adipogenesis and suppress lipolysis independently of sweet taste receptors.

    PubMed

    Simon, Becky R; Parlee, Sebastian D; Learman, Brian S; Mori, Hiroyuki; Scheller, Erica L; Cawthorn, William P; Ning, Xiaomin; Gallagher, Katherine; Tyrberg, Björn; Assadi-Porter, Fariba M; Evans, Charles R; MacDougald, Ormond A

    2013-11-08

    G protein-coupled receptors mediate responses to a myriad of ligands, some of which regulate adipocyte differentiation and metabolism. The sweet taste receptors T1R2 and T1R3 are G protein-coupled receptors that function as carbohydrate sensors in taste buds, gut, and pancreas. Here we report that sweet taste receptors T1R2 and T1R3 are expressed throughout adipogenesis and in adipose tissues. Treatment of mouse and human precursor cells with artificial sweeteners, saccharin and acesulfame potassium, enhanced adipogenesis. Saccharin treatment of 3T3-L1 cells and primary mesenchymal stem cells rapidly stimulated phosphorylation of Akt and downstream targets with functions in adipogenesis such as cAMP-response element-binding protein and FOXO1; however, increased expression of peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α was not observed until relatively late in differentiation. Saccharin-stimulated Akt phosphorylation at Thr-308 occurred within 5 min, was phosphatidylinositol 3-kinase-dependent, and occurred in the presence of high concentrations of insulin and dexamethasone; phosphorylation of Ser-473 occurred more gradually. Surprisingly, neither saccharin-stimulated adipogenesis nor Thr-308 phosphorylation was dependent on expression of T1R2 and/or T1R3, although Ser-473 phosphorylation was impaired in T1R2/T1R3 double knock-out precursors. In mature adipocytes, artificial sweetener treatment suppressed lipolysis even in the presence of forskolin, and lipolytic responses were correlated with phosphorylation of hormone-sensitive lipase. Suppression of lipolysis by saccharin in adipocytes was also independent of T1R2 and T1R3. These results suggest that some artificial sweeteners have previously uncharacterized metabolic effects on adipocyte differentiation and metabolism and that effects of artificial sweeteners on adipose tissue biology may be largely independent of the classical sweet taste receptors, T1R2 and T1R3.

  3. Purple corn silk: A potential anti-obesity agent with inhibition on adipogenesis and induction on lipolysis and apoptosis in adipocytes.

    PubMed

    Chaiittianan, Rungsiri; Sutthanut, Khaetthareeya; Rattanathongkom, Ariya

    2017-04-06

    Corn silk or the stigma of Zea mays L. has traditionally been used in weight loss stimulation and treatment of cystitis, urinary infections and obesity. Purple corn silk, rich of polyphenolic substances, was reported on anti-diabetic and anti-obesity effect in animal studies. However, scientific evidence on mechanisms and targets of action of purple corn silk related to adipocyte life cycle has been limited. To determine phytochemical compositions and investigate anti-obesity potential of the purple corn silk focusing on interruption of adipocyte life cycle; effect on pre-adipocyte proliferation, adipogenesis, adipocyte lipolysis, and apoptosis. The ethanolic purple corn silk extract (PCS) was prepared and investigated for phytochemical compositions by LC/MS/MS technique and anti-obesity potential using murine 3T3-L1 cell line. Using methyl thiazole tetrazolium (MTT) assay, the effects on pre-adipocytes and adipocyte viability and on pre-adipocytes proliferation at 24-, 48-, and 72-h incubation period were evaluated. In addition, anti-adipogenesis via inhibition on adipocyte differentiation and reduction of total lipid accumulation was evaluated using Oil Red O staining and spectrophotometric methods, respectively. The lipolysis effect was determined by measurement of glycerol released content using glycerol test kit after 48-h treatment of PCS to adipocytes. Apoptosis inductive effect was done by using 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride (DAPI) staining method. The polyphenols including anthocyanins, quercetin and phenolic acids and derivatives were found as the major chemical compositions of the PCS. With multiple-stages interruption on the adipocyte life cycle, anti-obesity effect of PCS was interestingly demonstrated. When compared to the control, the PCS at concentration range between 250-1000 μg/mL showed anti-adipogenesis effect as expressing of significant inhibition on pre-adipocyte proliferation at all incubation period (43.52±5

  4. Mathematical modeling of laser lipolysis

    PubMed Central

    Mordon, Serge R; Wassmer, Benjamin; Reynaud, Jean Pascal; Zemmouri, Jaouad

    2008-01-01

    energy, typically 5 cm3 for 3000 J. At last, skin retraction was observed in patients at 6-month follow up. This observation can be easily explained by mathematical modeling showing that the temperature increase inside the lower dermis is sufficient (48–50°C) to induce skin tightening Discussion and Conclusion Laser lipolysis can be described by a theoretical model. Fat volume reduction observed in patients is in accordance with model calculations. Due to heat diffusion, temperature elevation is also produced inside the lower reticular dermis. This interesting observation can explain remodeling of the collagenous tissue, with clinically evident skin tightening. In conclusion, while the heat generated by interstitial laser irradiation provides stimulate lipolysis of the fat cells, the collagen and elastin are also stimulated resulting in a tightening in the skin. This mathematical model should serve as a useful tool to simulate and better understand the mechanism of action of the laser lipolysis PMID:18312643

  5. Inhibition of Adipogenesis and Induction of Apoptosis and Lipolysis by Stem Bromelain in 3T3-L1 Adipocytes

    PubMed Central

    Dave, Sandeep; Kaur, Naval Jit; Nanduri, Ravikanth; Dkhar, H. Kitdorlang; Kumar, Ashwani; Gupta, Pawan

    2012-01-01

    The phytotherapeutic protein stem bromelain (SBM) is used as an anti-obesity alternative medicine. We show at the cellular level that SBM irreversibly inhibits 3T3-L1 adipocyte differentiation by reducing adipogenic gene expression and induces apoptosis and lipolysis in mature adipocytes. At the molecular level, SBM suppressed adipogenesis by downregulating C/EBPα and PPARγ independent of C/EBPβ gene expression. Moreover, mRNA levels of adipocyte fatty acid-binding protein (ap2), fatty acid synthase (FAS), lipoprotein lipase (LPL), CD36, and acetyl-CoA carboxylase (ACC) were also downregulated by SBM. Additionally, SBM reduced adiponectin expression and secretion. SBM's ability to repress PPARγ expression seems to stem from its ability to inhibit Akt and augment the TNFα pathway. The Akt–TSC2–mTORC1 pathway has recently been described for PPARγ expression in adipocytes. In our experiments, TNFα upregulation compromised cell viability of mature adipocytes (via apoptosis) and induced lipolysis. Lipolytic response was evident by downregulation of anti-lipolytic genes perilipin, phosphodiestersae-3B (PDE3B), and GTP binding protein Giα1, as well as sustained expression of hormone sensitive lipase (HSL). These data indicate that SBM, together with all-trans retinoic-acid (atRA), may be a potent modulator of obesity by repressing the PPARγ-regulated adipogenesis pathway at all stages and by augmenting TNFα-induced lipolysis and apoptosis in mature adipocytes. PMID:22292054

  6. QRFP-43 inhibits lipolysis by preventing ligand-induced complex formation between perilipin A, caveolin-1, the catalytic subunit of protein kinase and hormone-sensitive lipase in 3T3-L1 adipocytes.

    PubMed

    Mulumba, Mukandila; Granata, Riccarda; Marleau, Sylvie; Ong, Huy

    2015-05-01

    QRFP (RFamide) peptides are neuropeptides involved in food intake and adiposity regulation in rodents. We have previously shown that QRFP-43 (43RFa) and QRFP-26 (26RFa) inhibited isoproterenol (ISO)-induced lipolysis in adipocytes. However, the antilipolytic signaling pathways activated by QRFP peptides have not been investigated. In the present study, 3T3-L1 adipocytes were used to identify the main pathways involved in QRFP-43 decreasing ISO-induced lipolysis. Our results show that QRFP-43 reduced ISO-induced phosphorylation of perilipin A (PLIN) and hormone-sensitive lipase (HSL) on Ser660 by 43 and 25%, respectively, but increased Akt phosphorylation by 44%. However, the inhibition of phosphodiesterase 3B (PDE3B), a regulator of lipolysis activated by Akt, did not reverse the antilipolytic effect of QRFP-43. PDE3B inhibition reversed the decrease of Ser660 HSL phosphorylation associated with QRFP-43 antilipolytic effect. QRFP-43 also prevented PKC activation and ISO-induced Src kinases activation leading to the inhibition of the caveolin-1 (CAV-1) translocation on lipid droplets. Indeed, QRFP-43 attenuated phorbol 12-myristate 13-acetate-induced lipolysis and ISO-induced extracellular signal-regulated and Src kinases by 28, 37 and 48%, respectively. The attenuation of ISO-induced lipolysis by QRFP-43 was associated with a decrease of phosphorylated Ser660 HSL, PKA-catalytic (PKA-c) subunit and CAV-1 translocation on lipid droplets by 37, 50 and 46%, respectively. The decrease in ISO-induced CAV-1 and PKA-c translocation was associated with a reduction of PLIN phosphorylation by 44% in QRFP-43-treated adipocytes. These results suggest that QRFP-43 attenuated ISO-induced lipolysis by preventing the formation of an active complex on lipid droplets and the activation of Src kinases and PKC. Copyright © 2015. Published by Elsevier B.V.

  7. PD-1 alters T-cell metabolic reprogramming by inhibiting glycolysis and promoting lipolysis and fatty acid oxidation

    PubMed Central

    Patsoukis, Nikolaos; Bardhan, Kankana; Chatterjee, Pranam; Sari, Duygu; Liu, Bianling; Bell, Lauren N.; Karoly, Edward D.; Freeman, Gordon J.; Petkova, Victoria; Seth, Pankaj; Li, Lequn; Boussiotis, Vassiliki A.

    2015-01-01

    During activation, T cells undergo metabolic reprogramming, which imprints distinct functional fates. We determined that on PD-1 ligation, activated T cells are unable to engage in glycolysis or amino acid metabolism but have an increased rate of fatty acid β-oxidation (FAO). PD-1 promotes FAO of endogenous lipids by increasing expression of CPT1A, and inducing lipolysis as indicated by elevation of the lipase ATGL, the lipolysis marker glycerol and release of fatty acids. Conversely, CTLA-4 inhibits glycolysis without augmenting FAO, suggesting that CTLA-4 sustains the metabolic profile of non-activated cells. Because T cells utilize glycolysis during differentiation to effectors, our findings reveal a metabolic mechanism responsible for PD-1-mediated blockade of T-effector cell differentiation. The enhancement of FAO provides a mechanistic explanation for the longevity of T cells receiving PD-1 signals in patients with chronic infections and cancer, and for their capacity to be reinvigorated by PD-1 blockade. PMID:25809635

  8. Inhibition of intracellular lipolysis promotes human cancer cell adaptation to hypoxia

    PubMed Central

    Zhang, Xiaodong; Saarinen, Alicia M; Hitosugi, Taro; Wang, Zhenghe; Wang, Liguo; Ho, Thai H

    2017-01-01

    Tumor tissues are chronically exposed to hypoxia owing to aberrant vascularity. Lipid droplet (LD) accumulation is a hallmark of hypoxic cancer cells, yet how LDs form and function during hypoxia remains poorly understood. Herein, we report that in various cancer cells upon oxygen deprivation, HIF-1 activation down-modulates LD catabolism mediated by adipose triglyceride lipase (ATGL), the key enzyme for intracellular lipolysis. Proteomics and functional analyses identified hypoxia-inducible gene 2 (HIG2), a HIF-1 target, as a new inhibitor of ATGL. Knockout of HIG2 enhanced LD breakdown and fatty acid (FA) oxidation, leading to increased ROS production and apoptosis in hypoxic cancer cells as well as impaired growth of tumor xenografts. All of these effects were reversed by co-ablation of ATGL. Thus, by inhibiting ATGL, HIG2 acts downstream of HIF-1 to sequester FAs in LDs away from the mitochondrial pathways for oxidation and ROS generation, thereby sustaining cancer cell survival in hypoxia. PMID:29256392

  9. Adrenergic control of lipolysis in women compared with men

    PubMed Central

    Bessesen, Daniel H.; Stotz, Sarah; Peelor, Frederick F.; Miller, Benjamin F.; Horton, Tracy J.

    2014-01-01

    Data suggest women are more sensitive to the lipolytic action of epinephrine compared with men while maintaining similar glucoregulatory effects (Horton et al. J Appl Physiol 107: 200–210, 2009). This study aimed to determine the specific adrenergic receptor(s) that may mediate these sex differences. Lean women (n = 14) and men (n = 16) were studied on 4 nonconsecutive days during the following treatment infusions: saline (S: control), epinephrine [E: mixed β-adrenergic (lipolytic) and α2-adrenergic (antilipolytic) stimulation], epinephrine + phentolamine (E + P: mixed β-adrenergic stimulation only), and terbutaline (T: selective β2-adrenergic stimulation). Tracer infusions of glycerol, palmitate, and glucose were administered to determine systemic lipolysis, free fatty acid (FFA) release, and glucose turnover, respectively. Following basal measurements, substrate and hormone concentrations were measured in all subjects over 90 min of treatment and tracer infusion. Women had greater increases in glycerol and FFA concentrations with all three hormone infusions compared with men (P < 0.01). Glycerol and palmitate rate of appearance (Ra) and rate of disappearance (Rd) per kilogram body weight were greater with E infusion in women compared with men (P < 0.05), whereas no sex differences were observed with other treatments. Glucose concentration and kinetics were not different between sexes with any infusion. In conclusion, these data support the hypothesis that the greater rate of lipolysis in women with infusion of E was likely due to lesser α2 antilipolytic activation. These findings may help explain why women have greater lipolysis and fat oxidation during exercise, a time when epinephrine concentration is elevated. PMID:25190743

  10. Adipocyte triglyceride turnover and lipolysis in lean and overweight subjects.

    PubMed

    Rydén, Mikael; Andersson, Daniel P; Bernard, Samuel; Spalding, Kirsty; Arner, Peter

    2013-10-01

    Human obesity is associated with decreased triglyceride turnover and impaired lipolysis in adipocytes. We determined whether such defects also occur in subjects with only moderate increase in fat mass. Human abdominal subcutaneous adipose tissue was investigated in healthy, nonobese subjects [body mass index (BMI) > 17 kg/m(2) and BMI < 30 kg/m(2)]. Triglyceride age, reflecting lipid turnover, was examined in 41 subjects by assessing the incorporation of atmospheric (14)C into adipose lipids. Adipocyte lipolysis was examined as the ability of lipolytic agents to stimulate glycerol release in 333 subjects. Adipocyte triglyceride age was markedly increased in overweight (BMI ≥ 25 kg/m(2)) compared with lean subjects (P = 0.017) with triglyceride T1/2 of 14 and 9 months, respectively (P = 0.04). Triglyceride age correlated positively with BMI (P = 0.002) but not with adipocyte volume (P = 0.2). Noradrenaline-, isoprenaline- or dibutyryl cyclic AMP-induced lipolysis was inversely correlated with triglyceride age (P < 0.01) and BMI (P < 0.0001) independently of basal lipolysis, gender, and nicotine use. Current, but not the highest or lowest BMI in adult life, correlated significantly (inversely) with lipolysis. In conclusion, adipocyte triglyceride turnover and lipolytic activity are decreased in overweight subjects and reflect the current BMI status. These changes may confer an increased risk for early development and/or maintenance of excess body fat.

  11. Hydrolysis of bovine and caprine milk fat globules by lipoprotein lipase. Effects of heparin and skim milk on lipase distribution and on lipolysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sundheim, G.; Bengtsson-Olivecrona, G.

    1987-12-01

    Heparin can dissociate lipoprotein lipase from casein micelles, and addition of heparin enhances lipolysis in bovine but not in caprine milk. Heparin shortened the lag-time for binding of lipoprotein lipase to milk fat globules and for lipolysis. Heparin counteracted the inhibitory effects of skim milk on binding of lipase and on lipolysis. Heparin stimulated lipolysis in all bovine milk samples when added before cooling and in spontaneously lipolytic milk samples also when added after cooling. Heparin enhanced lipolysis of isolated milk fat globules. Hence, its effect is not solely due to dissociation of lipoprotein lipase from the casein micelles. Coolingmore » of goat milk caused more marked changes in the distribution of lipase than cooling of bovine milk; the fraction of added /sup 125/I-labeled lipase that bound to cream increased from about 8 to 60%. In addition, caprine skim milk caused less inhibition of lipolysis than bovine skim milk. These observations provide an explanation for the high degree of cold storage lipolysis in goat milk. Heparin had only small effects on the distribution of lipoprotein lipase in caprine milk, which explains why heparin has so little effect on lipolysis in caprine milk. The distribution of /sup 35/S-labeled heparin in bovine milk was studied. In warm milk less than 10% bound to the cream fraction, but when milk was cooled, binding of heparin to cream increased to 45%. These results suggest that there exists in the skim fraction a relatively small amount of a heparin-binding protein, which on cooling of milk adsorbs to the milk fat, or suggests that cooling induces a conformational change in a membrane protein such that its affinity for heparin increases.« less

  12. TGRL Lipolysis Products Induce Stress Protein ATF3 via the TGF-β Receptor Pathway in Human Aortic Endothelial Cells

    PubMed Central

    Eiselein, Larissa; Nyunt, Tun; Lamé, Michael W.; Ng, Kit F.; Wilson, Dennis W.; Rutledge, John C.; Aung, Hnin H.

    2015-01-01

    Studies have suggested a link between the transforming growth factor beta 1 (TGF-β1) signaling cascade and the stress-inducible activating transcription factor 3 (ATF3). We have demonstrated that triglyceride-rich lipoproteins (TGRL) lipolysis products activate MAP kinase stress associated JNK/c-Jun pathways resulting in up-regulation of ATF3, pro-inflammatory genes and induction of apoptosis in human aortic endothelial cells. Here we demonstrate increased release of active TGF-β at 15 min, phosphorylation of Smad2 and translocation of co-Smad4 from cytosol to nucleus after a 1.5 h treatment with lipolysis products. Activation and translocation of Smad2 and 4 was blocked by addition of SB431542 (10 μM), a specific inhibitor of TGF-β-activin receptor ALKs 4, 5, 7. Both ALK receptor inhibition and anti TGF-β1 antibody prevented lipolysis product induced up-regulation of ATF3 mRNA and protein. ALK inhibition prevented lipolysis product-induced nuclear accumulation of ATF3. ALKs 4, 5, 7 inhibition also prevented phosphorylation of c-Jun and TGRL lipolysis product-induced p53 and caspase-3 protein expression. These findings demonstrate that TGRL lipolysis products cause release of active TGF-β and lipolysis product-induced apoptosis is dependent on TGF-β signaling. Furthermore, signaling through the stress associated JNK/c-Jun pathway is dependent on TGF-β signaling suggesting that TGF-β signaling is necessary for nuclear accumulation of the ATF3/cJun transcription complex and induction of pro-inflammatory responses. PMID:26709509

  13. Inflammasome-driven catecholamine catabolism in macrophages blunts lipolysis in the aged

    PubMed Central

    Camell, Christina D.; Sander, Jil; Spadaro, Olga; Lee, Aileen; Nguyen, Kim Y.; Wing, Allison; Goldberg, Emily L.; Youm, Yun-Hee; Brown, Chester W.; Elsworth, John; Rodeheffer, Matthew S.; Schultze, Joachim L.; Dixit, Vishwa Deep

    2017-01-01

    Catecholamine-induced lipolysis, the first step in generation of energy substrates through hydrolysis of triglycerides (TGs) 1, declines with age 2,3. The defect in mobilization of free fatty acids (FFA) in elderly is accompanied with increased visceral adiposity, lower exercise capacity, failure to maintain core body temperature during cold stress, and reduced ability to survive starvation. While catecholamine signaling in adipocytes is normal in elderly, how lipolysis is impaired in aging remains unknown 2,4. Here we uncover that the adipose tissue macrophages (ATMs) regulate age-related reduction in adipocyte lipolysis by lowering the bioavailability of norepinephrine (NE). Unexpectedly, unbiased whole transcriptome analyses of adipose macrophages revealed that aging upregulates genes controlling catecholamine degradation in an NLRP3 inflammasome-dependent manner. Deletion of NLRP3 in aging restored catecholamine-induced lipolysis through downregulation of growth differentiation factor-3 (GDF3) and monoamine oxidase-a (MAOA) that is known to degrade NE. Consistent with this, deletion of GDF3 in inflammasome-activated macrophages improved lipolysis by decreasing MAOA and caspase-1. Furthermore, inhibition of MAOA reversed age-related reduction in adipose tissue NE concentration and restored lipolysis with increased levels of key lipolytic enzymes, adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL). Our study reveals that targeting neuro-innate signaling between sympathetic nervous system and macrophages may offer new approaches to mitigate chronic inflammation-induced metabolic impairment and functional decline. PMID:28953873

  14. Copper Regulates Cyclic AMP-Dependent Lipolysis

    PubMed Central

    Krishnamoorthy, Lakshmi; Cotruvo, Joseph A.; Chan, Jefferson; Kaluarachchi, Harini; Muchenditsi, Abigael; Pendyala, Venkata S.; Jia, Shang; Aron, Allegra T.; Ackerman, Cheri M.; Vander Wal, Mark N.; Guan, Timothy; Smaga, Lukas P.; Farhi, Samouil L.; New, Elizabeth J.; Lutsenko, Svetlana; Chang, Christopher J.

    2016-01-01

    Cell signaling relies extensively on dynamic pools of redox-inactive metal ions such as sodium, potassium, calcium, and zinc, but their redox-active transition metal counterparts such as copper and iron have been studied primarily as static enzyme cofactors. Here we report that copper is an endogenous regulator of lipolysis, the breakdown of fat, which is an essential process in maintaining the body's weight and energy stores. Utilizing a murine model of genetic copper misregulation, in combination with pharmacological alterations in copper status and imaging studies in a 3T3-L1 white adipocyte model, we demonstrate that copper regulates lipolysis at the level of the second messenger, cyclic AMP (cAMP), by altering the activity of the cAMP-degrading phosphodiesterase PDE3B. Biochemical studies of the copper-PDE3B interaction establish copper-dependent inhibition of enzyme activity and identify a key conserved cysteine residue within a PDE3-specific loop that is essential for the observed copper-dependent lipolytic phenotype. PMID:27272565

  15. Inhibition of lipolysis in the novel transgenic quail model overexpressing G0/G1 switch gene 2 in the adipose tissue during feed restriction.

    PubMed

    Shin, Sangsu; Choi, Young Min; Han, Jae Yong; Lee, Kichoon

    2014-01-01

    In addition to the issue of obesity in humans, the production of low-fat meat from domestic animals is important in the agricultural industry to satisfy consumer demand. Understanding the regulation of lipolysis in adipose tissue could advance our knowledge to potentially solve both issues. Although the G0/G1 switch gene 2 (G0S2) was recently identified as an inhibitor of adipose triglyceride lipase (ATGL) in vitro, its role in vivo has not been fully clarified. This study was conducted to investigate the role of G0S2 gene in vivo by using two independent transgenic quail lines during different energy conditions. Unexpectedly, G0S2 overexpression had a negligible effect on plasma NEFA concentration, fat cell size and fat pad weight under ad libitum feeding condition when adipose lipolytic activity is minimal. A two-week feed restriction in non-transgenic quail expectedly caused increased plasma NEFA concentration and dramatically reduced fat cell size and fat pad weight. Contrary, G0S2 overexpression under a feed restriction resulted in a significantly less elevation of plasma NEFA concentration and smaller reductions in fat pad weights and fat cell size compared to non-transgenic quail, demonstrating inhibition of lipolysis and resistance to loss of fat by G0S2. Excessive G0S2 inhibits lipolysis in vivo during active lipolytic conditions, such as food restriction and fasting, suggesting G0S2 as a potential target for treatment of obesity. In addition, transgenic quail are novel models for studying lipid metabolism and mechanisms of obesity.

  16. Changes of noradrenergic activity and lipolysis in the subcutaneous abdominal adipose tissue of hypo- and hyperthyroid patients: an in vivo microdialysis study.

    PubMed

    Nedvidkova, Jara; Haluzik, Martin; Bartak, Vladimir; Dostalova, Ivana; Vlcek, Petr; Racek, Pavel; Taus, Michal; Behanova, Magdalena; Svacina, Stepan; Alesci, Salvatore; Pacak, Karel

    2004-06-01

    Thyroid function plays an important role in the regulation of overall metabolic rate and lipid metabolism. However, it is uncertain whether thyroid hormones directly affect lipolysis in adipose tissue and to what extent those changes contribute to overall metabolic phenotype. Our study was designed, using the microdialysis technique, to determine basal and isoprenaline-stimulated local lipolysis and to determine local concentrations of lipolysis-regulating catecholamines in abdominal subcutaneous adipose tissue in 12 patients with hypothyroidism, 6 patients with hyperthyroidism, and 12 healthy control subjects. Plasma norepinephrine (NE) concentrations in hypothyroid subjects were significantly higher than in the control and hyperthyroid groups. In contrast, systemic, adipose NE levels in hypothyroid patients were decreased relative to controls. Hyperthyroidism, on the other hand, resulted in four-fold higher adipose NE levels. Basal lipolysis measured by glycerol concentrations in adipose tissue was significantly attenuated in hypothyroid patients and markedly increased in hyperthyroid patients in comparison with the control group. In addition to differences in basal lipolysis, hypothyroidism resulted in attenuated, and hyperthyroidism in enhanced, lipolytic response to local stimulation with beta(1,2)-adrenergic agonist isoprenaline. These results demonstrate that lipolysis in abdominal subcutaneous adipose tissue is strongly modulated by thyroid function. We suggest that thyroid hormones regulate lipolysis primarily by affecting local NE concentration and/or adrenergic postreceptor signaling.

  17. The effect of insulin, TNFα and DHA on the proliferation, differentiation and lipolysis of preadipocytes isolated from large yellow croaker (Pseudosciaena Crocea R.).

    PubMed

    Wang, Xinxia; Huang, Ming; Wang, Yizhen

    2012-01-01

    Fish final product can be affected by excessive lipid accumulation. Therefore, it is important to develop strategies to control obesity in cultivated fish to strengthen the sustainability of the aquaculture industry. As in mammals, the development of adiposity in fish depends on hormonal, cytokine and dietary factors. In this study, we investigated the proliferation and differentiation of preadipocytes isolated from the large yellow croaker and examined the effects of critical factors such as insulin, TNFα and DHA on the proliferation, differentiation and lipolysis of adipocytes. Preadipocytes were isolated by collagenase digestion, after which their proliferation was evaluated. The differentiation process was optimized by assaying glycerol-3-phosphate dehydrogenase (GPDH) activity. Oil red O staining and electron microscopy were performed to visualize the accumulated triacylglycerol. Gene transcript levels were measured using SYBR green quantitative real-time PCR. Insulin promoted preadipocytes proliferation, stimulated cell differentiation and decreased lipolysis of mature adipocytes. TNFα and DHA inhibited cell proliferation and differentiation. While TNFα stimulated mature adipocyte lipolysis, DHA showed no lipolytic effect on adipocytes. The expressions of adipose triglyceride lipase (ATGL), fatty acid synthase (FAS), lipoprotein lipase (LPL) and peroxisome proliferator-activated receptor α, γ (PPARα, PPARγ) were quantified during preadipocytes differentiation and adipocytes lipolysis to partly explain the regulation mechanisms. In summary, the results of this study indicated that although preadipocytes proliferation and the differentiation process in large yellow croaker are similar to these processes in mammals, the effects of critical factors such as insulin, TNFα and DHA on fish adipocytes development are not exactly the same. Our findings fill in the gaps in the basic data regarding the effects of critical factors on adiposity development in fish

  18. The lipolysis/esterification cycle of hepatic triacylglycerol. Its role in the secretion of very-low-density lipoprotein and its response to hormones and sulphonylureas.

    PubMed Central

    Wiggins, D; Gibbons, G F

    1992-01-01

    In hepatocyte cultures maintained in the absence of extracellular fatty acids, at least 70% of the secreted very-low-density lipoprotein (VLDL) triacylglycerol was derived via lipolysis of intracellular triacylglycerol. This proportion was unchanged when the cells were exposed for 24 h to insulin or glucagon, hormones which decreased the overall secretion of intracellular triacylglycerol, or to chloroquine or tolbutamide, agents which inhibit lysosomal lipolysis. The rate of intracellular lipolysis was 2-3-fold greater than that required to maintain the observed rate of triacylglycerol secretion. Most of the fatty acids released were returned to the intracellular pool. Neither insulin nor glucagon had any significant effect on the overall lipolysis and re-esterification of intracellular triacylglycerol. In these cases a greater proportion of the released fatty acids re-entered the cellular pool, rather than being recruited for VLDL assembly. Tolbutamide inhibited intracellular lipolysis, but suppressed VLDL secretion to a greater extent. 3,5-Dimethylpyrazole did not affect lipolysis or VLDL secretion. The increased secretion of VLDL triacylglycerol observed after exposure of cells to insulin for 3 days was not accompanied by an increased rate of intracellular lipolysis. However, a larger proportion of the triacylglycerol secreted under these conditions may not have undergone prior lipolysis. PMID:1599431

  19. Effects of Eucommia leaf extracts on autonomic nerves, body temperature, lipolysis, food intake, and body weight.

    PubMed

    Horii, Yuko; Tanida, Mamoru; Shen, Jiao; Hirata, Tetsuya; Kawamura, Naomi; Wada, Atsunori; Nagai, Katsuya

    2010-08-02

    Eucommia ulmoides Oliver leaf extracts (ELE) have been shown to exert a hypolipidemic effect in hamsters. Therefore, it was hypothesized that ELE might affect lipid metabolism via changes in autonomic nerve activities and causes changes in thermogenesis and body weight. We examined this hypothesis, and found that intraduodenal (ID) injection of ELE elevated epididymal white adipose tissue sympathetic nerve activity (WAT-SNA) and interscapular brown adipose tissue sympathetic nerve activity (BAT-SNA) in urethane-anesthetized rats and elevated the plasma concentration of free fatty acids (FFA) (a marker of lipolysis) and body temperature (BT) (a marker of thermogenesis) in conscious rats. Furthermore, it was observed that ID administration of ELE decreased gastric vagal nerve activity (GVNA) in urethane-anesthetized rats, and that ELE given as food reduced food intake, body and abdominal adipose tissue weights and decreased plasma triglyceride level. These findings suggest that ELE stimulates lipolysis and thermogenesis through elevations in WAT-SNA and BAT-SNA, respectively, suppresses appetite by inhibiting the activities of the parasympathetic nerves innervating the gastrointestinal tract, including GVNA, and decreases the amount of abdominal fat and body weight via these changes. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Jueming prescription and its ingredients, semen cassiae and Rhizoma Curcumae Longae, stimulate lipolysis and enhance the phosphorylation of hormone‑sensitive lipase in cultured rat white adipose tissue.

    PubMed

    Zhang, Yue; Li, Jiaojiao; Wen, Xiuying

    2017-11-01

    The present study aimed to investigate the effect of jueming prescription (JMP) and its ingredients, semen cassiae (SC) and Rhizoma Curcumae Longae (RCL), on lipolysis, and to examine their effect on the phosphorylation of hormone‑sensitive lipase (HSL) in cultured rat white adipose tissue (WAT). Retroperitoneal WAT was aseptically excised from adult male Sprague‑Dawley rats, minced into uniform sections and subjected to ex vivo culture for 24 h. The tissue sections were then distributed into a 24‑well culture plate and treated with normal saline (vehicle), isoproterenol (ISO), JMP, SC and RCL. Non‑esterified fatty acid (NEFA) and glycerol release from the intact WAT explants were determined as a measurement of lipolysis, which were measured using NEFA and glycerol assay kits. The phosphorylation of HSL at Ser563 (P‑HSL S563) and 660 residues (P‑HSL S660) were determined using western blot analysis. The size of the adipocytes was visualized using hematoxylin and eosin (H&E) staining. It was found that JMP‑, SC‑ and RCL‑stimulated lipolysis was responsible for increasing the release of NEFAs and glycerol from the intact WAT in vitro. In addition, JMP, SC and RCL increased the levels of P‑HSL Ser563: JMP water (JW) extract, 3.52‑fold; JMP ethanol (JE) extract, 3.38‑fold; SC water (SW) extract, 4.60‑fold; SC ethanol (SE) extract, 4.20‑fold; RCL water (RW) extract, 6.98‑fold; RCL ethanol (RE) extract, 6.60‑fold. JMP, SC and RCL also increased the levels of P‑HSL Ser660: JW extract, 3.16‑fold; JE extract, 2.92‑fold; SW extract, 4.57‑fold; SE extract, 4.13‑fold; RW extract, 5.41‑fold; RE 4.96‑fold) in the WAT. The RW extract had the most marked effect. The HE staining revealed that JMP, SC and RCL reduced the size of adipocytes in the WAT. In conclusion, JMP and its ingredients, SC and RC, stimulated lipolysis and reduced the size of adipocytes, possibly via the phosphorylation of HSL in cultured rat WAT.

  1. Lipolysis-Stimulating Peptide from Soybean Protects Against High Fat Diet-Induced Apoptosis in Skeletal Muscles.

    PubMed

    Marthandam Asokan, Shibu; Hung, Tsu-Han; Chiang, Wen-Dee; Lin, Wan-Teng

    2018-03-01

    Obesity is generally associated with low-grade chronic inflammation that involves the recruitment of macrophages and other inflammation factors to the adipocytes of obese individuals. Tumor necrosis factor-alpha (TNF-α), a cytokine associated with systemic inflammation, is elevated in conditions of obesity. TNF-α is an important factor that plays an important role in skeletal muscle wasting. Apoptosis of myonuclei contributes to the loss of muscle mass and therefore plays an important role in skeletal muscle atrophy. In mouse models that were fed a high fat diet (HFD), a lipolysis-stimulating peptide-VHVV (purified from hydrolysate resulting from flavourzyme treatment of soy protein) was found to reduce HFD-related apoptotic effects in mice skeletal muscle and potentially control atrophy. HFD fed mice had heavier body weight than those fed with normal chow, and VHVV administration restricted lipid accumulation in muscle tissues of mice fed with HFD but increased nutrient uptake. Moreover, specific concentrations of VHVV regulated TNF-α expression that was elevated by HFD, suppressed apoptosis-related proteins and regulated the proteins of lipid metabolism.

  2. Germline ablation of VGF increases lipolysis in white adipose tissue.

    PubMed

    Fargali, Samira; Scherer, Thomas; Shin, Andrew C; Sadahiro, Masato; Buettner, Christoph; Salton, Stephen R

    2012-11-01

    Targeted deletion of VGF, a neuronal and endocrine secreted protein and neuropeptide precursor, produces a lean, hypermetabolic mouse that is resistant to diet-, lesion-, and genetically induced obesity and diabetes. We hypothesized that increased sympathetic nervous system activity in Vgf-/Vgf- knockout mice is responsible for increased energy expenditure and decreased fat storage and that increased β-adrenergic receptor stimulation induces lipolysis in white adipose tissue (WAT) of Vgf-/Vgf- mice. We found that fat mass was markedly reduced in Vgf-/Vgf- mice. Within knockout WAT, phosphorylation of protein kinase A substrate increased in males and females, phosphorylation of hormone-sensitive lipase (HSL) (ser563) increased in females, and levels of adipose triglyceride lipase, comparative gene identification-58, and phospho-perilipin were higher in male Vgf-/Vgf- WAT compared with wild-type, consistent with increased lipolysis. The phosphorylation of AMP-activated protein kinase (AMPK) (Thr172) and levels of the AMPK kinase, transforming growth factor β-activated kinase 1, were decreased. This was associated with a decrease in HSL ser565 phosphorylation, the site phosphorylated by AMPK, in both male and female Vgf-/Vgf- WAT. No significant differences in phosphorylation of CREB or the p42/44 MAPK were noted. Despite this evidence supporting increased cAMP signaling and lipolysis, lipogenesis as assessed by fatty acid synthase protein expression and phosphorylated acetyl-CoA carboxylase was not decreased. Our data suggest that the VGF precursor or selected VGF-derived peptides dampen sympathetic outflow pathway activity to WAT to regulate fat storage and lipolysis.

  3. Microbial lipolysis at low temperatures.

    PubMed Central

    Andersson, R E

    1980-01-01

    It was found that lipase production during the growth of Pseudomonas fluorescens was not a function of the total number of bacteria. The optimal temperatures for bacterial growth and lipase production were determined as 20 and 8 degrees C, respectively. The lipolytic activity was studied in emulsions of olive oil at temperatures ranging from +8 to -30 degrees C. After an initially rapid lipolysis, the reactions retarded at different levels depending on storage temperature. Transference to a higher temperature resulted in a resumed lipolysis. Also, at low temperatures, lipolysis was studied as a function of water activity and was found to occur in dehydrated substrates. PMID:6766702

  4. Nobiletin enhances differentiation and lipolysis of 3T3-L1 adipocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saito, Takeshi; Abe, Daigo; Sekiya, Keizo

    2007-06-01

    Nobiletin is a polymethoxylated flavone found in certain citrus fruits. Here we demonstrate that nobiletin enhance differentiation of 3T3-L1 preadipocytes. Nobiletin dose-dependently increased accumulation of lipid droplets in adipocytes. Quantitative RT-PCR analyses indicated that nobiletin increased the expression of genes critical for acquisition of the adipocyte phenotype. Some of them were known peroxisome proliferator activated receptor {gamma} (PPAR{gamma}) targets and PPAR{gamma} itself, however, nobiletin did not exhibit PPAR{gamma} ligand activity. We observed the expression of CCAAT/enhancer binding protein {beta} (C/EBP{beta}), a transcription factor for PPAR{gamma}, was increased by nobiletin. The activation of cAMP-responsive element binding protein (CREB) and extracellular signal-regulatedmore » kinase (ERK), which play important roles in C/EBP{beta} expression were also potentiated by nobiletin. Furthermore, nobiletin stimulated lipolysis in differentiated adipocytes, which is known to be stimulated by cAMP pathway. These results suggested that nobiletin enhanced both differentiation and lipolysis of adipocyte through activation of signaling cascades mediated by cAMP/CREB.« less

  5. 11β-Hydroxysteroid dehydrogenase type 1 shRNA ameliorates glucocorticoid-induced insulin resistance and lipolysis in mouse abdominal adipose tissue.

    PubMed

    Wang, Ying; Yan, Chaoying; Liu, Limei; Wang, Wei; Du, Hanze; Fan, Winnie; Lutfy, Kabirullah; Jiang, Meisheng; Friedman, Theodore C; Liu, Yanjun

    2015-01-01

    Long-term glucocorticoid exposure increases the risk for developing type 2 diabetes. Prereceptor activation of glucocorticoid availability in target tissue by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) coupled with hexose-6-phosphate dehydrogenase (H6PDH) is an important mediator of the metabolic syndrome. We explored whether the tissue-specific modulation of 11β-HSD1 and H6PDH in adipose tissue mediates glucocorticoid-induced insulin resistance and lipolysis and analyzed the effects of 11β-HSD1 inhibition on the key lipid metabolism genes and insulin-signaling cascade. We observed that corticosterone (CORT) treatment increased expression of 11β-HSD1 and H6PDH and induced lipase HSL and ATGL with suppression of p-Thr(172) AMPK in adipose tissue of C57BL/6J mice. In contrast, CORT induced adipose insulin resistance, as reflected by a marked decrease in IR and IRS-1 gene expression with a reduction in p-Thr(308) Akt/PKB. Furthermore, 11β-HSD1 shRNA attenuated CORT-induced 11β-HSD1 and lipase expression and improved insulin sensitivity with a concomitant stimulation of pThr(308) Akt/PKB and p-Thr(172) AMPK within adipose tissue. Addition of CORT to 3T3-L1 adipocytes enhanced 11β-HSD1 and H6PDH and impaired p-Thr(308) Akt/PKB, leading to lipolysis. Knockdown of 11β-HSD1 by shRNA attenuated CORT-induced lipolysis and reversed CORT-mediated inhibition of pThr(172) AMPK, which was accompanied by a parallel improvement of insulin signaling response in these cells. These findings suggest that elevated adipose 11β-HSD1 expression may contribute to glucocorticoid-induced insulin resistance and adipolysis. Copyright © 2015 the American Physiological Society.

  6. Germline Ablation of VGF Increases Lipolysis in White Adipose Tissue

    PubMed Central

    Fargali, Samira; Scherer, Thomas; Shin, Andrew C.; Sadahiro, Masato; Buettner, Christoph; Salton, Stephen R.

    2012-01-01

    Targeted deletion of VGF, a neuronal and endocrine secreted protein and neuropeptide precursor, produces a lean, hypermetabolic mouse that is resistant to diet-, lesion-, and genetically-induced obesity and diabetes. We hypothesized that increased sympathetic nervous system activity in Vgf−/Vgf− knockout mice is responsible for increased energy expenditure and decreased fat storage, and that increased beta-adrenergic receptor stimulation induces lipolysis in white adipose tissue (WAT) of Vgf−/Vgf− mice. We found that fat mass was markedly reduced in Vgf−/Vgf− mice. Within knockout WAT, phosphorylation of protein kinase A (PKA) substrate increased in males and females, phosphorylation of hormone sensitive lipase (HSL) (Ser563) increased in females, and levels of adipose triglyceride lipase (ATGL), comparative gene identification-58 (CGI-58), and phospho-perilipin, were higher in male Vgf−/Vgf− WAT compared to wild type, consistent with increased lipolysis. The phosphorylation of AMP-activated protein kinase (AMPK) (Thr172) and levels of the AMPK kinase, transforming growth factor β-activated kinase 1 (TAK-1), were decreased. This was associated with a decrease in HSL Ser565 phosphorylation, the site phosphorylated by AMPK, in both male and female Vgf−/Vgf− WAT. No significant differences in phosphorylation of cAMP response element binding protein (CREB) or the p42/44 mitogen-activated protein kinase (MAPK) were noted. Despite this evidence supporting increased cAMP signaling and lipolysis, lipogenesis as assessed by fatty acid synthase (FAS) protein expression and phosphorylated acetyl-CoA carboxylase (pACC) was not decreased. Our data suggest that the VGF precursor or selected VGF-derived peptides dampen sympathetic outflow pathway activity to WAT to regulate fat storage and lipolysis. PMID:22942234

  7. Challenging the roles of CD44 and lipolysis stimulated lipoprotein receptor in conveying Clostridium perfringens iota toxin cytotoxicity in breast cancer.

    PubMed

    Fagan-Solis, Katerina D; Reaves, Denise K; Rangel, M Cristina; Popoff, Michel R; Stiles, Bradley G; Fleming, Jodie M

    2014-07-02

    Translational exploration of bacterial toxins has come to the forefront of research given their potential as a chemotherapeutic tool. Studies in select tissues have demonstrated that Clostridium perfringens iota toxin binds to CD44 and lipolysis stimulated lipoprotein receptor (LSR) cell-surface proteins. We recently demonstrated that LSR expression correlates with estrogen receptor positive breast cancers and that LSR signaling directs aggressive, tumor-initiating cell behaviors. Herein, we identify the mechanisms of iota toxin cytotoxicity in a tissue-specific, breast cancer model with the ultimate goal of laying the foundation for using iota toxin as a targeted breast cancer therapy. In vitro model systems were used to determine the cytotoxic effect of iota toxin on breast cancer intrinsic subtypes. The use of overexpression and knockdown technologies confirmed the roles of LSR and CD44 in regulating iota toxin endocytosis and induction of cell death. Lastly, cytotoxicity assays were used to demonstrate the effect of iota toxin on a validated set of tamoxifen resistant breast cancer cell lines. Treatment of 14 breast cancer cell lines revealed that LSR+/CD44- lines were highly sensitive, LSR+/CD44+ lines were slightly sensitive, and LSR-/CD44+ lines were resistant to iota cytotoxicity. Reduction in LSR expression resulted in a significant decrease in toxin sensitivity; however, overexpression of CD44 conveyed toxin resistance. CD44 overexpression was correlated with decreased toxin-stimulated lysosome formation and decreased cytosolic levels of iota toxin. These findings indicated that expression of CD44 drives iota toxin resistance through inhibition of endocytosis in breast cancer cells, a role not previously defined for CD44. Moreover, tamoxifen-resistant breast cancer cells exhibited robust expression of LSR and were highly sensitive to iota-induced cytotoxicity. Collectively, these data are the first to show that iota toxin has the potential to be an

  8. Effects of β-hydroxybutyrate and isoproterenol on lipolysis in isolated adipocytes from periparturient dairy cows and cows with clinical ketosis.

    PubMed

    van der Drift, S G A; Everts, R R; Houweling, M; van Leengoed, L A M G; Stegeman, J A; Tielens, A G M; Jorritsma, R

    2013-06-01

    An in vitro model was used to investigate effects of β-hydroxybutyrate and isoproterenol (β-adrenergic receptor agonist) on lipolysis in isolated adipocytes from late pregnant and recently calved dairy cows (n=5) and cows with clinical ketosis (n=3). Incubation with 3.0 mmol/L β-hydroxybutyrate reduced lipolysis in isolated adipocytes. This inhibitory effect was lower in the first lactation week (47%±16%) compared with late pregnancy (71%±6.5%). Incubation with 0.3 μmol/L isoproterenol stimulated lipolysis in isolated adipocytes from periparturient dairy cows. Basal lipolysis resulted in non-esterified fatty acid to glycerol ratios in the incubation media of 2.0±0.23 in prepartum samples, 2.1±0.23 in the first lactation week and 2.2±0.09 in cows with clinical ketosis. β-Hydroxybutyrate reduced lipolysis by 45%±9.6% in isolated adipocytes from cows with clinical ketosis, indicating that impaired feedback of β-hydroxybutyrate may not play a role in the disease etiology. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Periparturient lipolysis and oxylipid biosynthesis in bovine adipose tissues.

    PubMed

    Contreras, G Andres; Strieder-Barboza, Clarissa; de Souza, Jonas; Gandy, Jeff; Mavangira, Vengai; Lock, Adam L; Sordillo, Lorraine M

    2017-01-01

    The periparturient period of dairy cows is characterized by intense lipolysis in adipose tissues (AT), which induces the release of free fatty acids (FFA) into circulation. Among FFA, polyunsaturated fatty acids are susceptible to oxidation and can modulate inflammatory responses during lipolysis within AT. Linoleic and arachidonic acid oxidized products (oxylipids) such as hydroxy-octadecadienoic acids (HODE) and hydroxy-eicosatetraenoic acids (HETE), were recently identified as products of lipolysis that could modulate AT inflammation during lipolysis. However, the effect of lipolysis intensity during the transition from gestation to lactation on fatty acid substrate availability and subsequent AT oxylipid biosynthesis is currently unknown. We hypothesized that in periparturient dairy cows, alterations in AT and plasma fatty acids and oxylipid profiles coincide with changes in lipolysis intensity and stage of lactation. Blood and subcutaneous AT samples were collected from periparturient cows at -27±7 (G1) and -10±5 (G2) d prepartum and at 8±3 d postpartum (PP). Targeted lipidomic analysis was performed on plasma and AT using HPLC-MS/MS. We report that FFA concentrations increased as parturition approached and were highest at PP. Cows exhibiting high lipolysis rate at PP (FFA>1.0 mEq/L) had higher body condition scores at G1 compared to cows with low lipolysis rate (FFA<1.0 mEq/L). Concentrations of plasma linoleic and arachidonic acids were increased at PP. In AT, 13-HODE, and 5-, 11- and 15-HETE were increased at PP compared to G1 and G2. Concentrations of beta hydroxybutyrate were positively correlated with those of 13-HODE and 15-HETE in AT. Plasma concentrations of 5- and 20-HETE were increased at PP. These data demonstrate that prepartum adiposity predisposes cows to intense lipolysis post-partum and may exacerbate AT inflammation because of increased production of pro-inflammatory oxylipids including 5- and 15-HETE and 13-HODE. These results support a

  10. Periparturient lipolysis and oxylipid biosynthesis in bovine adipose tissues

    PubMed Central

    Strieder-Barboza, Clarissa; de Souza, Jonas; Gandy, Jeff; Mavangira, Vengai; Lock, Adam L.; Sordillo, Lorraine M.

    2017-01-01

    The periparturient period of dairy cows is characterized by intense lipolysis in adipose tissues (AT), which induces the release of free fatty acids (FFA) into circulation. Among FFA, polyunsaturated fatty acids are susceptible to oxidation and can modulate inflammatory responses during lipolysis within AT. Linoleic and arachidonic acid oxidized products (oxylipids) such as hydroxy-octadecadienoic acids (HODE) and hydroxy-eicosatetraenoic acids (HETE), were recently identified as products of lipolysis that could modulate AT inflammation during lipolysis. However, the effect of lipolysis intensity during the transition from gestation to lactation on fatty acid substrate availability and subsequent AT oxylipid biosynthesis is currently unknown. We hypothesized that in periparturient dairy cows, alterations in AT and plasma fatty acids and oxylipid profiles coincide with changes in lipolysis intensity and stage of lactation. Blood and subcutaneous AT samples were collected from periparturient cows at -27±7 (G1) and -10±5 (G2) d prepartum and at 8±3 d postpartum (PP). Targeted lipidomic analysis was performed on plasma and AT using HPLC-MS/MS. We report that FFA concentrations increased as parturition approached and were highest at PP. Cows exhibiting high lipolysis rate at PP (FFA>1.0 mEq/L) had higher body condition scores at G1 compared to cows with low lipolysis rate (FFA<1.0 mEq/L). Concentrations of plasma linoleic and arachidonic acids were increased at PP. In AT, 13-HODE, and 5-, 11- and 15-HETE were increased at PP compared to G1 and G2. Concentrations of beta hydroxybutyrate were positively correlated with those of 13-HODE and 15-HETE in AT. Plasma concentrations of 5- and 20-HETE were increased at PP. These data demonstrate that prepartum adiposity predisposes cows to intense lipolysis post-partum and may exacerbate AT inflammation because of increased production of pro-inflammatory oxylipids including 5- and 15-HETE and 13-HODE. These results support a

  11. The skeletal and heart muscle triacylglycerol lipolysis revisited.

    PubMed

    Knapp, M; Gorski, J

    2017-02-01

    For 40 years, the enzyme hormone sensitive lipase was considered to hydrolyze the first ester bond of the triacylglycerol moiety and thus initiate hydrolysis. However, 12 years ago a new lipolytic enzyme, termed adipose triglyceride lipase was discovered. It was further shown that the process of lipolysis of triacylglycerol to diacylglycerol and fatty acid is initiated by adipose triglyceride lipase and not by hormone sensitive lipase, responsible for hydrolysis of diacylglycerol to monoacyglycerol and fatty acid. Adipose triglyceride lipase is present in all types of cells containing neutral fat. The enzyme is activated by a protein called comparative gene identification-58 and inhibited by a protein called G0/G1 switch protein 2. It has also been discovered that perilipins, the main proteins coating lipid droplets in the cells, are involved in the process of triacylglycerol lipolysis. Five perilipins (1-5) were identified, however, up to now their role has been poorly assessed. In skeletal muscles, exercise and training affect the mRNA expression and protein content of adipose triglyceride lipase, comparative gene identification-58, G0/G1 switch protein 2, perilipin 2 and 5. The effect of exercise/training depends on exercise intensity and type of muscle fiber. An interaction between comparative gene identification-58 and adipose triglyceride lipase seems to be responsible for the enzyme activation during contractile activity. Adipose triglyceride lipase is also responsible for the activation of the first step of triacylglycerol lipolysis in the heart. There is substantial evidence that cardiac triacylglycerol metabolism affects the function of the heart. ATGL gene mutations leads to the development of neutral lipid storage diseases.

  12. Skeletal muscle PLIN3 and PLIN5 are serine phosphorylated at rest and following lipolysis during adrenergic or contractile stimulation

    PubMed Central

    MacPherson, Rebecca E K; Vandenboom, Rene; Roy, Brian D; Peters, Sandra J

    2013-01-01

    In adipose tissue, access of adipose triglyceride and hormone-sensitive lipases (ATGL and HSL) to the lipid droplet depends on PLIN1 phosphorylation, however, PLIN1 is not expressed in skeletal muscle and the phosphorylation of the expressed PLINs has yet to be investigated. Further, direct interactions between skeletal muscle PLINs and HSL are unknown. We investigated the isolated and combined effects of epinephrine and contraction on PLIN-to-lipase interactions as well as phosphorylation. Isolated rat solei were assigned to one of four 30 min in vitro conditions (25°C): (1) rest; (2) intermittent tetanic stimulation (60 Hz for 150 msec; train rate 20/min); (3) 5 nmol/L epinephrine; (4) intermittent tetanic stimulation and 5 nmol/L epinephrine. Immunoprecipitation of serine phosphorylated proteins followed by Western blotting for PLIN2, PLIN3, PLIN5, revealed that only PLIN2 is not phosphorylated under any of the experimental conditions. This is the first study to show that in whole rat skeletal muscle PLIN3 and PLIN5 are serine phosphorylated. The degree of serine phosphorylation remained unchanged following adrenergic and/or contractile stimulation. Oil red O staining of muscle sections for lipid content shows a significant decrease following each condition, confirming lipolysis occurred (P < 0.05). PLIN2, 3, and 5 all interact with HSL and ATGL, but these interactions were unchanged following treatments. Our results show that in skeletal muscle, PLIN2 is not serine phosphorylated at rest or with lipolytic stimulation and that while PLIN3, PLIN5 are serine phosphorylated at rest, the degree of phosphorylation does not change with lipolytic stimulation. PMID:24303154

  13. [Effect of the nonspecific biogenic stimulators pentoxyl and mumie on metabolic processes].

    PubMed

    Shvetskiĭ, A G; Vorob'eva, L M

    1978-01-01

    Unspecific biogenic stimulants (pentoxyl and mummie) accelerated metabolism of nucleic acids and protein in rat liver tissue. After the treatment with the stimulants the rate of lipolysis exceeded that of lipogenesis. Increase in content of lactate was similar if glycogen and glucose-6-phosphate were used as substrates of glycolysis, but it was stimulated 2-3-fold, when glucose was used; the phenomenon appears to be due to activation of hexokinase. As shown by polarographic measurements mitochondrial respiration was increased in all the metabolic states, but increased doses caused an inhibition of phosphorylation apparently due to functional overstrain of mitochondria. Increased doses of the stimulants accelerated also some other metabolic processes studied, but the effects were not dose-dependent. Pentoxyl and mummie apparently increased processes of protein and nuclei acid metabolism and stimulated the energy-providing reactions.

  14. Effect of beta-adrenergic stimulation on whole-body and abdominal subcutaneous adipose tissue lipolysis in lean and obese men.

    PubMed

    Jocken, J W E; Goossens, G H; van Hees, A M J; Frayn, K N; van Baak, M; Stegen, J; Pakbiers, M T W; Saris, W H M; Blaak, E E

    2008-02-01

    Obesity is characterised by increased triacylglycerol storage in adipose tissue. There is in vitro evidence for a blunted beta-adrenergically mediated lipolytic response in abdominal subcutaneous adipose tissue (SAT) of obese individuals and evidence for this at the whole-body level in vivo. We hypothesised that the beta-adrenergically mediated effect on lipolysis in abdominal SAT is also impaired in vivo in obese humans. We investigated whole-body and abdominal SAT glycerol metabolism in vivo during 3 h and 6 h [2H5]glycerol infusions. Arterio-venous concentration differences were measured in 13 lean and ten obese men after an overnight fast and during intravenous infusion of the non-selective beta-adrenergic agonist isoprenaline [20 ng (kg fat free mass)(-1) min(-1)]. Lean and obese participants showed comparable fasting glycerol uptake by SAT (9.7+/-3.4 vs 9.3+/-2.5% of total release, p=0.92). Furthermore, obese participants showed an increased whole-body beta-adrenergically mediated lipolytic response versus lean participants. However, their fasting lipolysis was blunted [glycerol rate of appearance: 7.3+/-0.6 vs 13.1+/-0.9 micromol (kg fat mass)(-1) min(-1), p<0.01], as was the beta-adrenergically mediated lipolytic response per unit SAT [Delta total glycerol release: 140+/-71 vs 394+/-112 nmol (100 g tissue)(-1) min(-1), p<0.05] compared with lean participants. Net triacylglycerol flux tended to increase in obese compared with lean participants during beta-adrenergic stimulation [Delta net triacylglycerol flux: 75+/-32 vs 16+/-11 nmol (100 g tissue)(-1) min(-1), p=0.06]. We demonstrated in vivo that beta-adrenergically mediated lipolytic response is impaired systematically and in abdominal SAT of obese versus lean men. This may be important in the development or maintenance of increased triacylglycerol stores and obesity.

  15. Challenging the roles of CD44 and lipolysis stimulated lipoprotein receptor in conveying Clostridium perfringens iota toxin cytotoxicity in breast cancer

    PubMed Central

    2014-01-01

    Background Translational exploration of bacterial toxins has come to the forefront of research given their potential as a chemotherapeutic tool. Studies in select tissues have demonstrated that Clostridium perfringens iota toxin binds to CD44 and lipolysis stimulated lipoprotein receptor (LSR) cell-surface proteins. We recently demonstrated that LSR expression correlates with estrogen receptor positive breast cancers and that LSR signaling directs aggressive, tumor-initiating cell behaviors. Herein, we identify the mechanisms of iota toxin cytotoxicity in a tissue-specific, breast cancer model with the ultimate goal of laying the foundation for using iota toxin as a targeted breast cancer therapy. Methods In vitro model systems were used to determine the cytotoxic effect of iota toxin on breast cancer intrinsic subtypes. The use of overexpression and knockdown technologies confirmed the roles of LSR and CD44 in regulating iota toxin endocytosis and induction of cell death. Lastly, cytotoxicity assays were used to demonstrate the effect of iota toxin on a validated set of tamoxifen resistant breast cancer cell lines. Results Treatment of 14 breast cancer cell lines revealed that LSR+/CD44- lines were highly sensitive, LSR+/CD44+ lines were slightly sensitive, and LSR-/CD44+ lines were resistant to iota cytotoxicity. Reduction in LSR expression resulted in a significant decrease in toxin sensitivity; however, overexpression of CD44 conveyed toxin resistance. CD44 overexpression was correlated with decreased toxin-stimulated lysosome formation and decreased cytosolic levels of iota toxin. These findings indicated that expression of CD44 drives iota toxin resistance through inhibition of endocytosis in breast cancer cells, a role not previously defined for CD44. Moreover, tamoxifen-resistant breast cancer cells exhibited robust expression of LSR and were highly sensitive to iota-induced cytotoxicity. Conclusions Collectively, these data are the first to show that iota

  16. Association of a beta-2 adrenoceptor (ADRB2) gene variant with a blunted in vivo lipolysis and fat oxidation.

    PubMed

    Jocken, J W E; Blaak, E E; Schiffelers, S; Arner, P; van Baak, M A; Saris, W H M

    2007-05-01

    Obesity is associated with a blunted beta-adrenoceptor-mediated lipolysis and fat oxidation. We investigated whether polymorphisms in codon 16, 27 and 164 of the beta (2)-adrenoceptor gene (ADRB2) and exon 10 of the G protein beta (3)-subunit gene (GNB3) are associated with alterations in in vivo lipolysis and fat oxidation. Sixty-five male and 43 female overweight and obese subjects (body mass index (BMI) range: 26.1-48.4 kg/m(2)) were included. Energy expenditure (EE), respiratory quotient (RQ), circulating free fatty acid (FFA) and glycerol levels were determined after stepwise infusion of increasing doses of the non-selective beta-agonist isoprenaline (ISO). In women, the Arg16 allele of the ADRB2 gene was associated with a blunted increase in circulating FFA, glycerol and a decreased fat oxidation during ISO stimulation. In men, the Arg16 allele was significantly associated with a blunted increase in FFA but not in glycerol or fat oxidation. These results suggest that genetic variation in the ADRB2 gene is associated with disturbances in in vivo beta-adrenoceptor-mediated lipolysis and fat oxidation during beta-adrenergic stimulation in overweight and obese subjects; these effects are influenced by gene-gender interactions.

  17. Beta cell compensation for insulin resistance in Zucker fatty rats: increased lipolysis and fatty acid signalling.

    PubMed

    Nolan, C J; Leahy, J L; Delghingaro-Augusto, V; Moibi, J; Soni, K; Peyot, M-L; Fortier, M; Guay, C; Lamontagne, J; Barbeau, A; Przybytkowski, E; Joly, E; Masiello, P; Wang, S; Mitchell, G A; Prentki, M

    2006-09-01

    The aim of this study was to determine the role of fatty acid signalling in islet beta cell compensation for insulin resistance in the Zucker fatty fa/fa (ZF) rat, a genetic model of severe obesity, hyperlipidaemia and insulin resistance that does not develop diabetes. NEFA augmentation of insulin secretion and fatty acid metabolism were studied in isolated islets from ZF and Zucker lean (ZL) control rats. Exogenous palmitate markedly potentiated glucose-stimulated insulin secretion (GSIS) in ZF islets, allowing robust secretion at physiological glucose levels (5-8 mmol/l). Exogenous palmitate also synergised with glucagon-like peptide-1 and the cyclic AMP-raising agent forskolin to enhance GSIS in ZF islets only. In assessing islet fatty acid metabolism, we found increased glucose-responsive palmitate esterification and lipolysis processes in ZF islets, suggestive of enhanced triglyceride-fatty acid cycling. Interruption of glucose-stimulated lipolysis by the lipase inhibitor Orlistat (tetrahydrolipstatin) blunted palmitate-augmented GSIS in ZF islets. Fatty acid oxidation was also higher at intermediate glucose levels in ZF islets and steatotic triglyceride accumulation was absent. The results highlight the potential importance of NEFA and glucoincretin enhancement of insulin secretion in beta cell compensation for insulin resistance. We propose that coordinated glucose-responsive fatty acid esterification and lipolysis processes, suggestive of triglyceride-fatty acid cycling, play a role in the coupling mechanisms of glucose-induced insulin secretion as well as in beta cell compensation and the hypersecretion of insulin in obesity.

  18. Study of drug concentration effects on in vitro lipolysis kinetics in medium-chain triglycerides by considering oil viscosity and surface tension.

    PubMed

    Arnold, Yvonne Elisabeth; Imanidis, Georgios; Kuentz, Martin

    2011-10-09

    Simple oil formulations are widely used in oral drug delivery and the fate of these systems is governed mainly by the dispersion and digestion process. The current work aimed to study concentration effects of six poorly water-soluble drugs on the in vitro lipolysis rate of medium-chain triglycerides. The results were compared with drug effects on oil viscosity and surface tension. First the different drugs were characterized by molecular modeling and their influence on physical oil properties was assessed. Herein capillary viscosimetry was employed as well as dynamic surface tensiometry. Subsequently, an apparent in vitro lipolysis rate was determined in biorelevant medium using an automated pH stat titrator linked to a thermo-controlled vessel. The different drugs exhibited varying effects on oil viscosity and surface tension. However, all drugs significantly lowered the apparent lipolysis rate of the oil. This effect was very similar among the different compounds with exception of orlistat, which practically blocked lipolysis because of a potent direct inhibition. The other drugs affected lipolysis kinetics most likely by different mechanism(s). In light of the obtained results, a drug effect on oil viscosity or surface tension appeared to play a minor role in reducing the lipolysis rate. The lipolysis kinetics was further not affected by the drug load, which was deemed advantageous from a pharmaceutical viewpoint. Different dose strengths are therefore not assumed to alter lipolysis kinetics, which is beneficial for limiting the variability of in vivo drug release. Further studies of drug solubility kinetics in the evolving digestion phases are, however, needed to finally assess potential effects of dosage strength in simple oil formulations. Copyright © 2011. Published by Elsevier B.V.

  19. Emodin up-regulates glucose metabolism, decreases lipolysis, and attenuates inflammation in vitro.

    PubMed

    Zhang, Xiaoyan; Zhang, Rong; Lv, Pengfei; Yang, Jian; Deng, Yujie; Xu, Jun; Zhu, Rongfeng; Zhang, Di; Yang, Ying

    2015-05-01

    Emodin, the major bioactive component of Rheum palmatum, has many different activities, including antitumor, anti-inflammatory, and antidiabetes effects. Recently, emodin was reported to regulate energy metabolism. In the present study, we further explored the effects of emodin on glucose and lipid metabolism. Differentiated C2C12 myotubes and 3T3-L1 adipocytes were treated with or without different concentrations of emodin (6.25, 12.5, 25 or 50 μmol/L) for different time (1 h, 3 h, 12 h, 24 h or 48 h). Glucose metabolism, oxygen consumption, lactic acid levels, glycerol levels, and inflammation pathways were then evaluated. Cells were collected for quantitative polymerase chain reaction (PCR) and western blot analysis. Emodin upregulated glucose uptake and consumption in both C2C12 myotubes and 3T3-L1 adipocytes, with glycolysis increased. Furthermore, emodin inhibited lipolysis under basal conditions (as well as in the presence of 10 ng/ml tumor necrosis factor (TNF-)-α in 3T3-L1 adipocytes) and significantly decreased phosphorylated perilipin. Moreover, emodin inhibited the nuclear factor-κB and extracellular signal-regulated kinase pathways in C2C12 myotubes and 3T3-L1 adipocytes. Emodin upregulates glucose metabolism, decreases lipolysis, and inhibits inflammation in C2C12 myotubes and 3T3-L1 adipocytes. © 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  20. Time course and specificity of lipolysis in Swiss cheese.

    PubMed

    Dherbécourt, Julien; Bourlieu, Claire; Maillard, Marie-Bernadette; Aubert-Frogerais, Lydie; Richoux, Romain; Thierry, Anne

    2010-11-24

    Controlling lipolysis in cheese is necessary to ensure the formation of desirable flavor. To get a better understanding of the mechanism of lipolysis in Swiss cheese, cheeses were manufactured with and without (control) the addition of Propionibacterium freudenreichii. Products of lipolysis were quantified throughout ripening. Half of the free fatty acids (FFA) released in milk (3.66 mg/g fat), in particular the short-chain FFA, were lost in the whey during curd drainage, whereas diglycerides and monoglycerides were retained within the curd. P. freudenreichii was responsible for the release of most FFA during ripening (10.84 and 0.39 mg/g fat in propionibacteria-containing and control cheeses, respectively). Indices of lipolysis displayed low specificity. All types of FFA were released, but butyric and palmitic acids more significantly, which could be due to a low sn-1,3 regioselectivity. All glycerides were hydrolyzed in the following order: monoglycerides>diglycerides>triglycerides. The results of this study show the quantitative and qualitative contributions of the different lipolytic agents to Swiss cheese lipolysis.

  1. Phosphatidic acid inhibits ceramide 1-phosphate-stimulated macrophage migration.

    PubMed

    Ouro, Alberto; Arana, Lide; Rivera, Io-Guané; Ordoñez, Marta; Gomez-Larrauri, Ana; Presa, Natalia; Simón, Jorge; Trueba, Miguel; Gangoiti, Patricia; Bittman, Robert; Gomez-Muñoz, Antonio

    2014-12-15

    Ceramide 1-phosphate (C1P) was recently demonstrated to potently induce cell migration. This action could only be observed when C1P was applied exogenously to cells in culture, and was inhibited by pertussis toxin. However, the mechanisms involved in this process are poorly understood. In this work, we found that phosphatidic acid (PA), which is structurally related to C1P, displaced radiolabeled C1P from its membrane-binding site and inhibited C1P-stimulated macrophage migration. This effect was independent of the saturated fatty acid chain length or the presence of a double bond in each of the fatty acyl chains of PA. Treatment of RAW264.7 macrophages with exogenous phospholipase D (PLD), an enzyme that produces PA from membrane phospholipids, also inhibited C1P-stimulated cell migration. Likewise, PA or exogenous PLD inhibited C1P-stimulated extracellularly regulated kinases (ERK) 1 and 2 phosphorylation, leading to inhibition of cell migration. However, PA did not inhibit C1P-stimulated Akt phosphorylation. It is concluded that PA is a physiological regulator of C1P-stimulated macrophage migration. These actions of PA may have important implications in the control of pathophysiological functions that are regulated by C1P, including inflammation and various cellular processes associated with cell migration such as organogenesis or tumor metastasis. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Immunogenic inhibition of prominent ruminal bacteria as a means to reduce lipolysis and biohydrogenation activity in vitro

    USDA-ARS?s Scientific Manuscript database

    Through the microbial processes of lipolysis and biohydrogenation, ruminal animals promote the accumulation of saturated fatty acids in their meat and milk. Anaerovibrio lipolyticus, Butyrivibrio fibrisolvens, and Propionibacterium avidum and acnes have been identified as contributors to ruminal li...

  3. Mesencephalic stimulation elicits inhibition of phrenic nerve activity in cat.

    PubMed Central

    Gallman, E A; Lawing, W L; Millhorn, D E

    1991-01-01

    1. Previous work from this laboratory has indicated that the mesencephalon is the anatomical substrate for a mechanism capable of inhibiting central respiratory drive in glomectomized cats for periods of up to 1 h or more following brief exposure to systemic hypoxia; phrenic nerve activity was used as an index of central respiratory drive. 2. The present study was undertaken to further localize the region responsible for the observed post-hypoxic inhibition of respiratory drive. We studied the phrenic nerve response to stimulations of the mesencephalon in anaesthetized, paralysed peripherally chemo-denervated cats with end-expired PCO2 and body temperature servo-controlled. 3. Stimulations of two types were employed. Electrical stimulation allowed rapid determination of sites from which phrenic inhibition could be elicited. Microinjections of excitatory amino acids were used subsequently in order to confine excitation to neuronal cell bodies and not axons of passage. 4. Stimulation of discrete regions of the ventromedial aspect of the mesencephalon in the vicinity of the red nucleus produced substantial inhibition of phrenic activity which lasted up to 45 min. Stimulation of other areas of the mesencephalon either produced no phrenic inhibition or resulted in a slight stimulation of phrenic activity. 5. The results are discussed in the context of the central respiratory response to hypoxia. PMID:1676420

  4. The effect of vagus nerve stimulation on response inhibition.

    PubMed

    Schevernels, Hanne; van Bochove, Marlies E; De Taeye, Leen; Bombeke, Klaas; Vonck, Kristl; Van Roost, Dirk; De Herdt, Veerle; Santens, Patrick; Raedt, Robrecht; Boehler, C Nico

    2016-11-01

    In the current study, we explored whether vagus nerve stimulation (VNS) in patients with epilepsy, which is believed to increase norepinephrine (NE) levels via activation of the locus coeruleus, would positively affect response inhibition. Moreover, we tried to identify the dynamics of the underlying neural processes by investigating event-related potentials (ERPs) and pupil size. Patients performed a stop-signal task once when stimulation was switched on and once when it was switched off. We found a correlational pattern suggesting that patients who clinically benefit more from VNS treatment also show a larger behavioral advantage, in terms of faster response inhibition, when the vagus nerve is being stimulated. Event-related potential (ERP) results suggested more pronounced reactive inhibition when stimulation was switched on, independent of the individual amount of seizure reduction. Transient go-locked pupil size was increased from go trials to successful stop trials to unsuccessful stop trials but without displaying a clear VNS effect, which however, might relate to limited sensitivity. We conclude that VNS likely has a positive effect on response inhibition, at least in patients with epilepsy that benefit clinically from the treatment, presumably relating to enhancements of response-inhibition mechanisms and, therefore, identify enhanced response inhibition as a possible cognitive benefit of VNS. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Pyrrolidine Dithiocarbamate (PDTC) Attenuates Cancer Cachexia by Affecting Muscle Atrophy and Fat Lipolysis

    PubMed Central

    Miao, Chunxiao; Lv, Yuanyuan; Zhang, Wanli; Chai, Xiaoping; Feng, Lixing; Fang, Yanfen; Liu, Xuan; Zhang, Xiongwen

    2017-01-01

    Cancer cachexia is a kind of whole body metabolic disorder syndrome accompanied with severe wasting of muscle and adipose tissue. NF-κB signaling plays an important role during skeletal muscle atrophy and fat lipolysis. As an inhibitor of NF-κB signaling, Pyrrolidine dithiocarbamate (PDTC) was reported to relieve cancer cachexia; however, its mechanism remains largely unknown. In our study, we showed that PDTC attenuated cancer cachexia symptom in C26 tumor bearing mice models in vivo without influencing tumor volume. What’s more, PDTC inhibited muscle atrophy and lipolysis in cells models in vitro induced by TNFα and C26 tumor medium. PDTC suppressed atrophy of myotubes differentiated from C2C12 by reducing MyoD and upregulating MuRF1, and preserving the expression of perilipin as well as blocking the activation of HSL in 3T3-L1 mature adipocytes. Meaningfully, we observed that PDTC also inhibited p38 MAPK signaling besides the NF-κB signaling in cancer cachexia in vitro models. In addition, PDTC also influenced the protein synthesis of skeletal muscle by activating AKT signaling and regulated fat energy metabolism by inhibiting AMPK signaling. Therefore, PDTC primarily influenced different pathways in different tissues. The study not only established a simple and reliable screening drugs model of cancer cachexia in vitro but also provided new theoretical basis for future treatment of cancer cachexia. PMID:29311924

  6. Effects of arecoline on adipogenesis, lipolysis, and glucose uptake of adipocytes-A possible role of betel-quid chewing in metabolic syndrome

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hsu, Hsin-Fen; Tsou, Tsui-Chun, E-mail: tctsou@nhri.org.t; Chao, How-Ran

    To investigate the possible involvement of betel-quid chewing in adipocyte dysfunction, we determined the effects of arecoline, a major alkaloid in areca nuts, on adipogenic differentiation (adipogenesis), lipolysis, and glucose uptake by fat cells. Using mouse 3T3-L1 preadipocytes, we showed that arecoline inhibited adipogenesis as determined by oil droplet formation and adipogenic marker gene expression. The effects of arecoline on lipolysis of differentiated 3T3-L1 adipocytes were determined by the glycerol release assay, indicating that arecoline induced lipolysis in an adenylyl cyclase-dependent manner. The diabetogenic effects of arecoline on differentiated 3T3-L1 adipocytes were evaluated by the glucose uptake assay, revealing thatmore » {>=} 300 {mu}M arecoline significantly attenuated insulin-induced glucose uptake; however, no marked effect on basal glucose uptake was detected. Moreover, using 94 subjects that were randomly selected from a health check-up, we determined the association of betel-quid chewing with hyperlipidemia and its related risk factors. Hyperlipidemia frequency and serum triglyceride levels of betel-quid chewers were significantly higher than those of non-betel-quid chewers. In this study, we demonstrated that arecoline inhibits adipogenic differentiation, induces adenylyl cyclase-dependent lipolysis, and interferes with insulin-induced glucose uptake. Arecoline-induced fat cell dysfunction may lead to hyperlipidemia and hyperglycemia/insulin-resistance. These findings provide the first in vitro evidence of betel-quid chewing modulation of adipose cell metabolism that could contribute to the explanation of the association of this habit with metabolic syndrome disorders.« less

  7. Piecing together the puzzle of perilipin proteins and skeletal muscle lipolysis.

    PubMed

    MacPherson, Rebecca E K; Peters, Sandra J

    2015-07-01

    The regulation of skeletal muscle lipolysis and fat oxidation is a complex process involving multiple proteins and enzymes. Emerging work indicates that skeletal muscle PLIN proteins likely play a role in the hydrolysis of triglycerides stored in lipid droplets and the passage of fatty acids to the mitochondria for oxidation. In adipocytes, PLIN1 regulates lipolysis by interacting with comparative gene identification-58 (CGI-58), an activator of adipose triglyceride lipase (ATGL). Upon lipolytic stimulation, PLIN1 is phosphorylated, releasing CGI-58 to activate ATGL and initiate triglyceride breakdown. The absence of PLIN1 in skeletal muscle leads us to believe that other PLIN family members undertake this role. The focus of this review is on the PLIN family proteins expressed in skeletal muscle: PLIN2, PLIN3, and PLIN5. To date, most studies involving these PLIN proteins have used nonmuscle tissues and cell cultures to determine their potential roles. Results from work in these models support a role for PLIN proteins in sequestering lipases during basal conditions and in potentially working together for lipase translocation and activity during lipolysis. In skeletal muscle, PLIN2 tends to mirror the lipid content and may play a role in lipid droplet growth and stability through lipase interactions on the lipid droplet surface, whereas the skeletal muscle roles of both PLIN3 and PLIN5 seem to be more complex because they are found not only on the lipid droplet, but also at the mitochondria. Clearly, further work is needed to fully understand the intricate mechanisms by which PLIN proteins contribute to skeletal muscle lipid metabolism.

  8. In vivo study of lipid synthesis and lipolysis dynamics by stimulated Raman scattering microscopy

    NASA Astrophysics Data System (ADS)

    Li, Xuesong; Li, Yan; He, Sicong; Chen, Congping; Qin, Zhongya; Mak, Ho Yi; Qu, Jianan Y.

    2018-02-01

    To understand the mechanisms of important lipid-related biological processes and diseases, it is highly demanded to study the dynamics of lipids in living biological system with high spatiotemporal resolution. However, in vivo quantitative analysis of lipid synthesis and lipolysis has been technically difficult to achieve by conventional lipid extraction and fluorescent staining methods. Recently, SRS microscopy has emerged as a powerful tool to probe small molecules with alkyne (C≡C) or deuterium (C-D) labeling in cell-silent region. The Raman tags have been used for the quantitative study of lipids in cells. In this study, we investigated metabolic dynamics of lipid droplets (LDs) by tracing the alkyne-tagged fatty acid 17-ODYA and deuterium-labeled saturated and unsaturated fatty acids PA-D31 & OA-D34 in living C. elegans. Specifically, we developed a hyperspectral SRS microscope system for LDs characterization. The system can sequentially excite and probe the stimulated Raman scattering-induced CH2 stretching of endogenous lipids information (2863 cm-1), C≡C stretching from 17-ODYA (2125 cm-1) and C-D stretching from deuterium-labeled fatty acids (2117 cm-1). We first examined the concentration levels of fatty acids in E. coli OP50. Two major lipid metabolic processes, namely uptake and turnover, were further studied in adult C. elegans. We imaged alkyne-tagged and deuterated fatty acids using SRS and traced their uptake, transportation, incorporation and turnover over time. Additionally, several other treatments including starvation were also conducted to study their effects on metabolic dynamics of pulse labeled 17-ODYA, PA-D31 and OA-D34.

  9. Comparison of Blood Loss in Laser Lipolysis vs Traditional Liposuction.

    PubMed

    Abdelaal, Mohammed Mahmoud; Aboelatta, Yasser Abdallah

    2014-08-01

    Laser-assisted liposuction has been associated with reduced blood loss. However, this clinical finding has not been evaluated objectively. In this study, the authors objectively estimated the blood loss volume associated with laser lipolysis vs traditional liposuction in various anatomic regions. In this prospective study, 56 patients underwent equal amounts of traditional and laser-assisted liposuction at 2 contralateral anatomic sites. Blood loss volumes were calculated from the lipoaspirates by measuring hemoglobin and red blood cell content. The data were analyzed statistically with repeated-measures analysis of variance and the Mann-Whitney U test. Laser lipolysis can reduce blood loss by more than 50% compared with traditional liposuction. Laser lipolysis resulted in significant reductions in mean blood loss volumes in the abdomen, flanks, back, and breast. The authors provide objective evidence that laser lipolysis significantly reduces blood loss compared with traditional liposuction. 3. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

  10. Alterations of the Lipid Metabolome in Dairy Cows Experiencing Excessive Lipolysis Early Postpartum

    PubMed Central

    Humer, Elke; Khol-Parisini, Annabella; Metzler-Zebeli, Barbara U.; Gruber, Leonhard; Zebeli, Qendrim

    2016-01-01

    A decrease in insulin sensitivity enhances adipose tissue lipolysis helping early lactation cows counteracting their energy deficit. However, excessive lipolysis poses serious health risks for cows, and its underlying mechanisms are not clearly understood. The present study used targeted ESI-LC-MS/MS-based metabolomics and indirect insulin sensitivity measurements to evaluate metabolic alterations in the serum of dairy cows of various parities experiencing variable lipolysis early postpartum. Thirty (12 primiparous and 18 multiparous) cows of Holstein Friesian and Simmental breeds, fed the same diet and kept under the same management conditions, were sampled at d 21 postpartum and classified as low (n = 10), medium (n = 8), and high (n = 12) lipolysis groups, based on serum concentration of nonesterified fatty acids. Overall, excessive lipolysis in the high group came along with impaired estimated insulin sensitivity and characteristic shifts in acylcarnitine, sphingomyelin, phosphatidylcholine and lysophospholipid metabolome profiles compared to the low group. From the detected phosphatidylcholines mainly those with diacyl-residues showed differences among lipolysis groups. Furthermore, more than half of the detected sphingomyelins were increased in cows experiencing high lipomobilization. Additionally, strong differences in serum acylcarnitines were noticed among lipolysis groups. The study suggests an altered serum phospholipidome in dairy cows associated with an increase in certain long-chain sphingomyelins and the progression of disturbed insulin function. In conclusion, the present study revealed 37 key metabolites as part of alterations in the synthesis or breakdown of sphingolipids and phospholipids associated with lowered estimated insulin sensitivity and excessive lipolysis in early-lactating cows. PMID:27383746

  11. Alterations of the Lipid Metabolome in Dairy Cows Experiencing Excessive Lipolysis Early Postpartum.

    PubMed

    Humer, Elke; Khol-Parisini, Annabella; Metzler-Zebeli, Barbara U; Gruber, Leonhard; Zebeli, Qendrim

    2016-01-01

    A decrease in insulin sensitivity enhances adipose tissue lipolysis helping early lactation cows counteracting their energy deficit. However, excessive lipolysis poses serious health risks for cows, and its underlying mechanisms are not clearly understood. The present study used targeted ESI-LC-MS/MS-based metabolomics and indirect insulin sensitivity measurements to evaluate metabolic alterations in the serum of dairy cows of various parities experiencing variable lipolysis early postpartum. Thirty (12 primiparous and 18 multiparous) cows of Holstein Friesian and Simmental breeds, fed the same diet and kept under the same management conditions, were sampled at d 21 postpartum and classified as low (n = 10), medium (n = 8), and high (n = 12) lipolysis groups, based on serum concentration of nonesterified fatty acids. Overall, excessive lipolysis in the high group came along with impaired estimated insulin sensitivity and characteristic shifts in acylcarnitine, sphingomyelin, phosphatidylcholine and lysophospholipid metabolome profiles compared to the low group. From the detected phosphatidylcholines mainly those with diacyl-residues showed differences among lipolysis groups. Furthermore, more than half of the detected sphingomyelins were increased in cows experiencing high lipomobilization. Additionally, strong differences in serum acylcarnitines were noticed among lipolysis groups. The study suggests an altered serum phospholipidome in dairy cows associated with an increase in certain long-chain sphingomyelins and the progression of disturbed insulin function. In conclusion, the present study revealed 37 key metabolites as part of alterations in the synthesis or breakdown of sphingolipids and phospholipids associated with lowered estimated insulin sensitivity and excessive lipolysis in early-lactating cows.

  12. Laser lipolysis with pulsed 1064 nm Nd:YAG laser for the treatment of gynecomastia.

    PubMed

    Rho, Yong Kwan; Kim, Beom Joon; Kim, Myeung Nam; Kang, Kweon Soo; Han, Hee Jin

    2009-12-01

    Lipolysis using laser is currently widely used for reducing localized fat. A 1064 nm neodynium-doped yttrium aluminum garnet (Nd:YAG) laser lipolysis was investigated in this study to evaluate its efficacy and safety in the treatment of gynecomastia. Five male patients diagnosed with gynecomastia were enrolled in this study, which was designed as a controlled split-breast trial. One breast of each patient was subjected to laser lipolysis and was then compared with a contralateral breast. Photographs and clinical assessments were obtained before the lipolysis, and at the fourth and eighth weeks thereafter. Computed tomography (CT) scan and ultrasound (US) imaging were used to evaluate the changes in the breasts' thicknesses. The mean chest circumference was found to have been significantly reduced 8 weeks after the laser lipolysis. The clinical outcomes of the laser lipolysis were considered favorable by both the patients and clinicians. The CT and US scans showed that the thicknesses of the treated right breasts reduced more than those of the left breasts were 8 weeks after the laser lipolysis. The side effects (pain, edema, and ecchymosis) were minimal and disappeared shortly after they first manifested. Limitations The limitations of this study are that it employed small treatment groups and short-term follow-up. This study demonstrated that gynecomastia can be treated effectively and safely through 1064 nm Nd:YAG laser lipolysis.

  13. Cytosolic lipolysis and lipophagy: two sides of the same coin.

    PubMed

    Zechner, Rudolf; Madeo, Frank; Kratky, Dagmar

    2017-11-01

    Fatty acids are the most efficient substrates for energy production in vertebrates and are essential components of the lipids that form biological membranes. Synthesis of triacylglycerols from non-esterified free fatty acids (FFAs) combined with triacylglycerol storage represents a highly efficient strategy to stockpile FFAs in cells and prevent FFA-induced lipotoxicity. Although essentially all vertebrate cells have some capacity to store and utilize triacylglycerols, white adipose tissue is by far the largest triacylglycerol depot and is uniquely able to supply FFAs to other tissues. The release of FFAs from triacylglycerols requires their enzymatic hydrolysis by a process called lipolysis. Recent discoveries thoroughly altered and extended our understanding of lipolysis. This Review discusses how cytosolic 'neutral' lipolysis and lipophagy, which utilizes 'acid' lipolysis in lysosomes, degrade cellular triacylglycerols as well as how these pathways communicate, how they affect lipid metabolism and energy homeostasis and how their dysfunction affects the pathogenesis of metabolic diseases. Answers to these questions will likely uncover novel strategies for the treatment of prevalent metabolic diseases.

  14. Aciculatin Inhibits Granulocyte Colony-Stimulating Factor Production by Human Interleukin 1β-Stimulated Fibroblast-Like Synoviocytes

    PubMed Central

    Shih, Kao-Shang; Wang, Jyh-Horng; Wu, Yi-Wen; Teng, Che-Ming; Chen, Chien-Chih; Yang, Chia-Ron

    2012-01-01

    The expression of granulocyte colony-stimulating factor (G-CSF), the major regulator of neutrophil maturation, by human fibroblast-like synoviocytes (FLS) can be stimulated by the inflammatory cytokine interleukin-1β (IL-1β). G-CSF is known to contribute to the pathologic processes of destructive arthritis, but the induction mechanism remains unknown. The aims of this study were to identify the signaling pathways involved in IL-1β-stimulated G-CSF production and to determine whether this process was inhibited by aciculatin (8-((2R,4S,5S,6R)-tetrahydro-4,5-dihydroxy-6-methyl-2H-pyran-2-yl)-5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-4H-chromen-4-one), the major bioactive component of Chrysopogon aciculatus. IL-1β-induced cytokine expression was evaluated by measuring mRNA and protein levels by RT-PCR, ELISA, and Milliplex® assay. Whether aciculatin inhibited IL-1β-stimulated G-CSF expression, and if so, how, were evaluated using western blot assay, an electrophoretic mobility shift assay, and a reporter gene assay. Neutrophil differentiation was determined by Wright-Giemsa staining and flow cytometry. Aciculatin markedly inhibited G-CSF expression induced by IL-1β (10 ng/mL) in a concentration-dependent manner (1–10 µM). In clarifying the mechanisms involved, aciculatin was found to inhibit the IL-1β-induced activation of the IκB kinase (IKK)/IκB/nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways by suppressing the DNA binding activity of the transcription factors NF-κB and activator protein (AP)-1. Furthermore, aciculatin significantly inhibited the G-CSF-mediated phosphorylation of Janus kinase-signal transducer and activator of transcription (JAK-STAT) and Akt and neutrophil differentiation from precursor cells. Our results show that aciculatin inhibits IL-1β-stimulated G-CSF expression and the subsequent neutrophil differentiation, suggesting that it might have therapeutic potential for inflammatory arthritis. PMID

  15. White Tea extract induces lipolytic activity and inhibits adipogenesis in human subcutaneous (pre)-adipocytes

    PubMed Central

    Söhle, Jörn; Knott, Anja; Holtzmann, Ursula; Siegner, Ralf; Grönniger, Elke; Schepky, Andreas; Gallinat, Stefan; Wenck, Horst; Stäb, Franz; Winnefeld, Marc

    2009-01-01

    Background The dramatic increase in obesity-related diseases emphasizes the need to elucidate the cellular and molecular mechanisms underlying fat metabolism. To investigate how natural substances influence lipolysis and adipogenesis, we determined the effects of White Tea extract on cultured human subcutaneous preadipocytes and adipocytes. Methods For our in vitro studies we used a White Tea extract solution that contained polyphenols and methylxanthines. Utilizing cultured human preadipocytes we investigated White Tea extract solution-induced inhibition of triglyceride incorporation during adipogenesis and possible effects on cell viability. In vitro studies on human adipocytes were performed aiming to elucidate the efficacy of White Tea extract solution to stimulate lipolytic activity. To characterize White Tea extract solution-mediated effects on a molecular level, we analyzed gene expression of essential adipogenesis-related transcription factors by qRT-PCR and determined the expression of the transcription factor ADD1/SREBP-1c on the protein level utilizing immunofluorescence analysis. Results Our data show that incubation of preadipocytes with White Tea extract solution significantly decreased triglyceride incorporation during adipogenesis in a dose-dependent manner (n = 10) without affecting cell viability (n = 10). These effects were, at least in part, mediated by EGCG (n = 10, 50 μM). In addition, White Tea extract solution also stimulated lipolytic activity in adipocytes (n = 7). Differentiating preadipocytes cultivated in the presence of 0.5% White Tea extract solution showed a decrease in PPARγ, ADD1/SREBP-1c, C/EBPα and C/EBPδ mRNA levels. Moreover, the expression of the transcription factor ADD1/SREBP-1c was not only decreased on the mRNA but also on the protein level. Conclusion White Tea extract is a natural source that effectively inhibits adipogenesis and stimulates lipolysis-activity. Therefore, it can be utilized to modulate different

  16. Treatment of Lipoma by Injection Lipolysis

    PubMed Central

    Nanda, Soni

    2011-01-01

    Injection lipolysis or lipodissolve is the practice of injecting phosphatidyl choline/ sodium deoxycholate (PDC/DC) compounds in the subcutaneous fat. Though this practice is being used extensively for nonsurgical contouring of body and dissolving localized collections of excess fat, it's use as a treatment modality for lipomas needs further evaluation. We present a case where this technique was used for treating a lipoma, with no recurrence after 9 months of follow up. Injection lipolysis as a treatment modality for lipomas needs to be evaluated for safety and efficacy in trials on larger population. This could prove to be a very valuable adjunct to the current practice of excision, if done by a trained person in a properly selected patient. Also the side effects and the controversies regarding this procedure have been discussed in detail in the present paper. PMID:21976907

  17. Plerocercoid growth factor (PGF), a human growth hormone (hGH) analogue produced by the tapeworm Spirometra mansonoides, has direct insulin-like action in adipose tissue of normal rats in vitro

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Salem, M.A.M.; Phares, C.K.

    1986-03-01

    The metabolic actions of GH can be divided into acute (insulin-like) and chronic (lipolytic/anti-insulin). The insulin-like actions of GH are most readily elicited in GH-deficient animals as GH induces resistance to its own insulin-like action. Like GH, PGF stimulates growth and cross-reacts with anti-hGH antibodies. Independent experiments were conducted comparing the direct actions of PGF to insulin or hGH in vitro. Insulin-like effects were determined by the ability of PGF, insulin or hGH to stimulate (U-/sup 14/C)glucose metabolism in epidydimal fat pads from normal rats and by inhibition of epinephrine-stimulated lipolysis. Direct stimulation of lipolysis was used as anti-insulin activity.more » To determine if PGF competes for insulin or GH receptors, adipocytes (3 x 10/sup 5/ cells/ml) were incubated with either (/sup 125/I)insulin or (/sup 125/I)hGH +/- PGF, +/- insulin or +/- hGH. PGF stimulated glucose oxidation and /sup 14/C-incorporation into lipids. Insulin, hGH and PGF inhibited lipolysis (33%, 29% and 34%, respectively). Adipose tissue was very sensitive to the lipolytic effect of hGH but PGF was neither lipolytic nor did it confer refractoriness to its insulin-like action. PGF bound to GH but not to insulin receptors. Therefore, PGF had direct insulin-like effects but did not stimulate lipolysis in tissue from normal rats in vitro.« less

  18. Regional acidosis locally inhibits but remotely stimulates Ca2+ waves in ventricular myocytes

    PubMed Central

    Ford, Kerrie L.; Moorhouse, Emma L.; Bortolozzi, Mario; Richards, Mark A.; Swietach, Pawel; Vaughan-Jones, Richard D.

    2017-01-01

    Abstract Aims Spontaneous Ca2+ waves in cardiomyocytes are potentially arrhythmogenic. A powerful controller of Ca2+ waves is the cytoplasmic H+ concentration ([H+]i), which fluctuates spatially and temporally in conditions such as myocardial ischaemia/reperfusion. H+-control of Ca2+ waves is poorly understood. We have therefore investigated how [H+]i co-ordinates their initiation and frequency. Methods and results Spontaneous Ca2+ waves were imaged (fluo-3) in rat isolated ventricular myocytes, subjected to modest Ca2+-overload. Whole-cell intracellular acidosis (induced by acetate-superfusion) stimulated wave frequency. Pharmacologically blocking sarcolemmal Na+/H+ exchange (NHE1) prevented this stimulation, unveiling inhibition by H+. Acidosis also increased Ca2+ wave velocity. Restricting acidosis to one end of a myocyte, using a microfluidic device, inhibited Ca2+ waves in the acidic zone (consistent with ryanodine receptor inhibition), but stimulated wave emergence elsewhere in the cell. This remote stimulation was absent when NHE1 was selectively inhibited in the acidic zone. Remote stimulation depended on a locally evoked, NHE1-driven rise of [Na+]i that spread rapidly downstream. Conclusion Acidosis influences Ca2+ waves via inhibitory Hi+ and stimulatory Nai+ signals (the latter facilitating intracellular Ca2+-loading through modulation of sarcolemmal Na+/Ca2+ exchange activity). During spatial [H+]i-heterogeneity, Hi+-inhibition dominates in acidic regions, while rapid Nai+ diffusion stimulates waves in downstream, non-acidic regions. Local acidosis thus simultaneously inhibits and stimulates arrhythmogenic Ca2+-signalling in the same myocyte. If the principle of remote H+-stimulation of Ca2+ waves also applies in multicellular myocardium, it raises the possibility of electrical disturbances being driven remotely by adjacent ischaemic areas, which are known to be intensely acidic. PMID:28339694

  19. Regional acidosis locally inhibits but remotely stimulates Ca2+ waves in ventricular myocytes.

    PubMed

    Ford, Kerrie L; Moorhouse, Emma L; Bortolozzi, Mario; Richards, Mark A; Swietach, Pawel; Vaughan-Jones, Richard D

    2017-07-01

    Spontaneous Ca2+ waves in cardiomyocytes are potentially arrhythmogenic. A powerful controller of Ca2+ waves is the cytoplasmic H+ concentration ([H+]i), which fluctuates spatially and temporally in conditions such as myocardial ischaemia/reperfusion. H+-control of Ca2+ waves is poorly understood. We have therefore investigated how [H+]i co-ordinates their initiation and frequency. Spontaneous Ca2+ waves were imaged (fluo-3) in rat isolated ventricular myocytes, subjected to modest Ca2+-overload. Whole-cell intracellular acidosis (induced by acetate-superfusion) stimulated wave frequency. Pharmacologically blocking sarcolemmal Na+/H+ exchange (NHE1) prevented this stimulation, unveiling inhibition by H+. Acidosis also increased Ca2+ wave velocity. Restricting acidosis to one end of a myocyte, using a microfluidic device, inhibited Ca2+ waves in the acidic zone (consistent with ryanodine receptor inhibition), but stimulated wave emergence elsewhere in the cell. This remote stimulation was absent when NHE1 was selectively inhibited in the acidic zone. Remote stimulation depended on a locally evoked, NHE1-driven rise of [Na+]i that spread rapidly downstream. Acidosis influences Ca2+ waves via inhibitory Hi+ and stimulatory Nai+ signals (the latter facilitating intracellular Ca2+-loading through modulation of sarcolemmal Na+/Ca2+ exchange activity). During spatial [H+]i-heterogeneity, Hi+-inhibition dominates in acidic regions, while rapid Nai+ diffusion stimulates waves in downstream, non-acidic regions. Local acidosis thus simultaneously inhibits and stimulates arrhythmogenic Ca2+-signalling in the same myocyte. If the principle of remote H+-stimulation of Ca2+ waves also applies in multicellular myocardium, it raises the possibility of electrical disturbances being driven remotely by adjacent ischaemic areas, which are known to be intensely acidic. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Cardiology.

  20. Sinensetin enhances adipogenesis and lipolysis by increasing cyclic adenosine monophosphate levels in 3T3-L1 adipocytes.

    PubMed

    Kang, Seong-Il; Shin, Hye-Sun; Kim, Se-Jae

    2015-01-01

    Sinensetin is a rare polymethoxylated flavone (PMF) found in certain citrus fruits. In this study, we investigated the effects of sinensetin on lipid metabolism in 3T3-L1 cells. Sinensetin promoted adipogenesis in 3T3-L1 preadipocytes growing in incomplete differentiation medium, which did not contain 3-isobutyl-1-methylxanthine. Sinensetin up-regulated expression of the adipogenic transcription factors peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein (C/EBP) α, and sterol regulatory element-binding protein 1c. It also potentiated expression of C/EBPβ and activation of cAMP-responsive element-binding protein. Sinensetin enhanced activation of protein kinase A and increased intracellular cAMP levels in 3T3-L1 preadipocytes. In mature 3T3-L1 adipocytes, sinensetin stimulated lipolysis via a cAMP pathway. Taken together, these results suggest that sinensetin enhances adipogenesis and lipolysis by increasing cAMP levels in adipocytes.

  1. Imatinib mesylate inhibits platelet derived growth factor stimulated proliferation of rheumatoid synovial fibroblasts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sandler, Charlotta; Joutsiniemi, Saima; Lindstedt, Ken A.

    Synovial fibroblast is the key cell type in the growth of the pathological synovial tissue in arthritis. Here, we show that platelet-derived growth factor (PDGF) is a potent mitogen for synovial fibroblasts isolated from patients with rheumatoid arthritis. Inhibition of PDGF-receptor signalling by imatinib mesylate (1 {mu}M) completely abrogated the PDGF-stimulated proliferation and inhibited approximately 70% of serum-stimulated proliferation of synovial fibroblasts. Similar extent of inhibition was observed when PDGF was neutralized with anti-PDGF antibodies, suggesting that imatinib mesylate does not inhibit pathways other than those mediated by PDGF-receptors. No signs of apoptosis were detected in synovial fibroblasts cultured inmore » the presence of imatinib. These results suggest that imatinib mesylate specifically inhibits PDGF-stimulated proliferation of synovial fibroblasts, and that inhibition of PDGF-receptors could represent a feasible target for novel antirheumatic therapies.« less

  2. Is transcranial direct current stimulation a potential method for improving response inhibition?

    PubMed

    Kwon, Yong Hyun; Kwon, Jung Won

    2013-04-15

    Inhibitory control of movement in motor learning requires the ability to suppress an inappropriate action, a skill needed to stop a planned or ongoing motor response in response to changes in a variety of environments. This study used a stop-signal task to determine whether transcranial direct-current stimulation over the pre-supplementary motor area alters the reaction time in motor inhibition. Forty healthy subjects were recruited for this study and were randomly assigned to either the transcranial direct-current stimulation condition or a sham-transcranial direct-current stimulation condition. All subjects consecutively performed the stop-signal task before, during, and after the delivery of anodal transcranial direct-current stimulation over the pre-supplementary motor area (pre-transcranial direct-current stimulation phase, transcranial direct-current stimulation phase, and post-transcranial direct-current stimulation phase). Compared to the sham condition, there were significant reductions in the stop-signal processing times during and after transcranial direct-current stimulation, and change times were significantly greater in the transcranial direct-current stimulation condition. There was no significant change in go processing-times during or after transcranial direct-current stimulation in either condition. Anodal transcranial direct-current stimulation was feasibly coupled to an interactive improvement in inhibitory control. This coupling led to a decrease in the stop-signal process time required for the appropriate responses between motor execution and inhibition. However, there was no transcranial direct-current stimulation effect on the no-signal reaction time during the stop-signal task. Transcranial direct-current stimulation can adjust certain behaviors, and it could be a useful clinical intervention for patients who have difficulties with response inhibition.

  3. Histamine stimulates chloride secretion in omeprazole-inhibited frog gastric mucosa

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McGreevy, J.; Barton, R.; Housinger, T.

    1986-03-05

    Omeprazole (OME) stops hydrogen ion (H) secretion in the histamine (HIST)-stimulated gastric mucosa while the chloride (Cl) which had accompanied the H continues to be pumped into the lumen. This finding suggests that the Cl pump is independent of the H/K ATP-ase driven H pump. To test this hypothesis, 16 Ussing-chambered frog mucosas were exposed to OME prior to HIST stimulation. If the Cl pump is independent, HIST should stimulate Cl secretion in the OME-inhibited mucosa. A 1 hr control (CON) interval preceded exposure to OME (10/sup -4/M) in the nutrient solution. Potential difference (PD), short-circuit current (Isc), resistance (R),more » H flux (J/sup H/) and Cl flux (J/sup Cl/ with /sup 36/Cl) were measured every 15 min. After 1 hr of OME exposure, HIST (10/sup -5/M) was added to the nutrient solution. The findings demonstrate that HIST stimulates Cl secretion in the OME-inhibited bullfrog gastric mucosa.« less

  4. Focused Ultrasound Lipolysis in the Treatment of Abdominal Cellulite: An Open-Label Study

    PubMed Central

    Moravvej, Hamideh; Akbari, Zahra; Mohammadian, Shahrzad; Razzaghi, Zahra

    2015-01-01

    Introduction: Despite a growing popularity of noninvasive ultrasonic lipolysis procedure, there is a lack of evidence about the efficacy of this method. This study was performed to evaluate the efficacy of focused ultrasonic lipolysis on abdominal cellulite treatment. Methods: Twenty-eight consecutive subjects (age: 37.8 ± 8 years) underwent weekly transdermal focused ultrasonic lipolysis (Med Contour, General Project Ltd., Florence, Italy) and vacuum drainage for a maximum of eight sessions. Largest abdominal girth and 2 lines at 4 cm to 7 cm distance above and under it were located as fixed points of measurements. The mean value of the three fixed lines was considered as the abdominal circumference. Subjects were evaluated using measurements of circumference, immediately after and 3 weeks after the final treatment and compared using paired t test. Results: One hundred ninety-four ultrasonic lipolysis procedures were performed on 28 subjects. A statistically significant (P < .001) average of 1.89 cm (95% CI: 1.63-2.02 cm) decrease of circumference value was observed in each session of ultrasonic lipolysis. The mean pretreatment to posttreatment circumference reduction was 8.21 cm (95% CI: 6.38-10.04, P < .001) that declined to 7 cm (95% CI: 3.2-10.8, P < .001) at the 3-month follow-up visit. Conclusion: Focused ultrasonic lipolysis appears to be an effective method for reduction of abdominal cellulite, although some amount of circumference reduction reversal may be observed in long term follow-up visit. PMID:26464776

  5. Quantitative study of digestive enzyme secretion and gastrointestinal lipolysis in chronic pancreatitis.

    PubMed

    Carrière, Frédéric; Grandval, Philippe; Renou, Christophe; Palomba, Aurélie; Priéri, Florence; Giallo, Jacqueline; Henniges, Friederike; Sander-Struckmeier, Suntje; Laugier, René

    2005-01-01

    The contribution of human gastric lipase (HGL) to the overall lipolysis process in chronic pancreatitis (CP), as well as the relative pancreatic enzyme levels, rarely are addressed. This study was designed to quantify pancreatic and extrapancreatic enzyme output, activity, and stability in CP patients vs. healthy volunteers. Healthy volunteers (n = 6), mild CP patients (n = 5), and severe (n = 7) CP patients were intubated with gastric and duodenal tubes before the administration of a test meal. HGL, human pancreatic lipase (HPL), chymotrypsin, and amylase concentrations were assessed in gastric and duodenal samples by measuring the respective enzymatic activities. Intragastric and overall lipolysis levels at the angle of Treitz were estimated based on quantitative analysis of lipolysis products. Similar analyses were performed on duodenal contents incubated ex vivo for studying enzyme stability and evolution of lipolysis. Although HPL, chymotrypsin, and amylase outputs all were extremely low, HGL outputs in patients with severe CP (46.8 +/- 31.0 mg) were 3-4-fold higher than in healthy controls (13.3 +/- 13.8 mg). Intragastric lipolysis did not increase, however, in patients with severe CP, probably because of the rapid decrease in the pH level of the gastric contents caused by a higher gastric acid secretion. HGL remains active and highly stable in the acidic duodenal contents of CP patients, and, overall, can achieve a significant lipolysis of the dietary triglycerides (30% of the control values) in the absence of HPL. Although all pancreatic enzyme secretions are simultaneously reduced in severe CP, gastric lipase can compensate partly for the loss of pancreatic lipase but not normalize overall lipolytic activity.

  6. Skeletal muscle PLIN proteins, ATGL and CGI-58, interactions at rest and following stimulated contraction

    PubMed Central

    Ramos, Sofhia V.; Vandenboom, Rene; Roy, Brian D.; Peters, Sandra J.

    2013-01-01

    Evidence indicates that skeletal muscle lipid droplet-associated proteins (PLINs) regulate lipolysis through protein-protein interactions on the lipid droplet surface. In adipocytes, PLIN1 is thought to regulate lipolysis by directly interacting with comparative gene identification-58 (CGI-58), an activator of adipose triglyceride lipase (ATGL). Upon lipolytic stimulation, PLIN1 is phosphorylated, releasing CGI-58 to fully activate ATGL and initiate triglyceride breakdown. The absence of PLIN1 in skeletal muscle leads us to believe that other PLIN family members undertake this role. Our purpose was to examine interactions between PLIN2, PLIN3, and PLIN5, with ATGL and its coactivator CGI-58 at rest and following contraction. Isolated rat solei were incubated for 30 min at rest or during 30 min of intermittent tetanic stimulation [150-ms volleys at 60 Hz with a train rate of 20 tetani/min (25°C)] to maximally stimulate intramuscular lipid breakdown. Results show that the interaction between ATGL and CGI-58 increased 128% following contraction (P = 0.041). Further, ATGL interacts with PLIN2, PLIN3, and PLIN5 at rest and following contraction. The PLIN2-ATGL interaction decreased significantly by 21% following stimulation (P = 0.013). Both PLIN3 and PLIN5 coprecipitated with CGI-58 at rest and following contraction, while there was no detectable interaction between PLIN2 and CGI-58 in either condition. Therefore, our findings indicate that in skeletal muscle, during contraction-induced muscle lipolysis, ATGL and CGI-58 strongly associate and that the PLIN proteins work together to regulate lipolysis, in part, by preventing ATGL and CGI-58 interactions at rest. PMID:23408028

  7. Platyphylloside Isolated From Betula platyphylla Inhibit Adipocyte Differentiation and Induce Lipolysis Via Regulating Adipokines Including PPARγ in 3T3-L1 Cells

    PubMed Central

    Lee, Mina; Sung, Sang Hyun

    2016-01-01

    Background: Obesity causes or aggravates many health problems, both independently and in association with several pathological disorders, including Type II diabetes, hypertension, atherosclerosis, and cancer. Therefore, we screened small compounds isolated from natural products for the development of anti-obesity drugs. Objective: The purpose of this study was to investigate the anti-adipogenic activities of platyphylloside, diarylheptanoid isolated from Betula platyphylla, which was selected based on the screening using 3T3-L1 cells. Materials and Methods: To evaluate the inhibition of adipocyte differentiation and lipolysis, lipid contents of BPP on were measured using Oil Red O staining in 3T3-L1 cells. The mRNA and protein expression levels of various adipokines were measured by Quantitative real-time PCR and Western blotting analysis, respectively. Results: Platyphylloside showed significant inhibitory activity on adipocyte differentiation in 3T3-L1 cells and suppressed adipocyte differentiation even in the presence of troglitazone, a PPARγ agonist. Platyphylloside might suppress adipocyte differentiation through PPARγ, C/EBPα, and SREBP1-induced adipogenesis, which is synergistically associated with downstream adipocyte-specific gene promoters such as aP2, FAS, SCD-1, LPL, and Adiponectin. In addition, platyphylloside affected lipolysis by down-regulating perilipin and HSL and up-regulating TNFα. Conclusion: Taken together, the results reveal that platyphylloside has anti-adipogenic activity and highlight its potential in the prevention and treatment of obesity. SUMMARY The extract of B. platyphylla bark and its isolate, BPP, had anti-adipogenic activity in 3T3-L1 cells via suppression of adipocyte differentiation from preadipocytes.Treatment with BPP significantly down-regulated the expression of PPARγ, C/EBP, C/EBPβ, C/EBPδ, SREBP1c, SCD-1, FAS, aP2 and LPL.BPP induced a lipolytic response in mature adipocytes via up-regulation krof TNFá and down

  8. Laser lipolysis: skin tightening in lipoplasty using a diode laser.

    PubMed

    Wolfenson, Moisés; Hochman, Bernardo; Ferreira, Lydia Massako

    2015-05-01

    New devices have been developed for surgical repair of deformities caused by localized fat deposits associated with skin laxity. The use of these devices requires the adoption of safety parameters. The aim of this study was to investigate skin tightening by laser lipolysis, using a dual-wavelength diode laser. This prospective, cross-sectional study was conducted between June of 2008 and July of 2010 with 41 consecutive patients who underwent laser lipolysis to correct contour deformities. Laser lipolysis was performed with a diode laser operating at two wavelengths (924 and 975 nm) controlled independently, and using three different tip lengths, allowing treatment of small, medium, and large areas of adipose tissue. The procedure was performed under local anesthesia in a surgical setting. To calculate the optimal cumulative energy, a total energy dose of 5 kJ/10 × 10-cm skin area was used as a safety parameter to prevent treatment complications. The circumferences of body regions were measured preoperatively, immediately after surgery, and 90 days later. Measurements were compared using the Wilcoxon test at a significance level of 0.05 (p < 0.05). A significant skin tightening was observed in all patients, regardless of the body site involved (i.e., face, breast, arms, or waist regions), and no complications occurred. Laser lipolysis results in progressive skin tightening over time. Therapeutic, IV.

  9. Ex vivo laser lipolysis assisted with radially diffusing optical applicator

    NASA Astrophysics Data System (ADS)

    Hwang, Jieun; Hau, Nguyen Trung; Park, Sung Yeon; Rhee, Yun-Hee; Ahn, Jin-Chul; Kang, Hyun Wook

    2016-05-01

    Laser-assisted lipolysis has been implemented to reduce body fat in light of thermal interactions with adipose tissue. However, using a flat fiber with high irradiance often needs rapid cannula movements and even undesirable thermal injury due to direct tissue contact. The aim of the current study was to explore the feasibility of a radially diffusing optical applicator to liquefy the adipose tissue for effective laser lipolysis. The proposed diffuser was evaluated with a flat fiber in terms of temperature elevation and tissue liquefaction after laser lipolysis with a 980-nm wavelength. Given the same power (20 W), the diffusing applicator generated a 30% slower temperature increase with a 25% lower maximum temperature (84±3.2°C in 1 min p<0.001) in the tissue, compared with the flat fiber. Under the equivalent temperature development, the diffuser induced up to fivefold larger area of the adipose liquefaction due to radial light emission than the flat fiber. Ex vivo tissue tests for 5-min irradiation demonstrated that the diffuser (1.24±0.15 g) liquefied 66% more adipose tissue than the flat fiber (0.75±0.05 g). The proposed diffusing applicator can be a feasible therapeutic device for laser lipolysis due to low temperature development and wide coverage of thermal treatment.

  10. Isolated milk fat globules as substrate for lipoprotein lipase: study of factors relevant to spontaneous lipolysis in milk

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sundheim, G.; Bengtsson-Olivecrona, G.

    1987-03-01

    Fat globules isolated from normal and from spontaneous milk samples were compared as substrates for purified lipoprotein lipase. Only slight differences were observed. Fat globules isolated from fresh warm milk were almost resistant to lipolysis. This included globules from milk prone to spontaneous lipolysis. Cooling made the globules accessible to rapid lipolysis even if they were from normal milk. Rewarming the fat globules did not reverse the process. Maximum rate of lipolysis (after rewarming) required fat globules be stored at 10/sup 0/C or below for 5 to 10 h. Lipolysis at 4/sup 0/C usually started after a lag time ofmore » 3 to 5 h, but with fat globules from spontaneous milk the lag time was shorter. Fat globules isolated from cold milk were a poor substrate at 4/sup 0/C but were lipolyzed when warmed. When /sup 125/I-labeled lipase was added to fresh warm milk, some of the lipase bound to the milk fat globules but it caused little lipolysis. Binding increased after cooling, as did lipolysis. Both binding of lipase and lipolysis were impeded by the presence of skim milk. Another way to make fat globules isolated from fresh warm milk susceptible to lipolysis was to treat them with chemicals known to remove proteins.« less

  11. Characterization of antilipolytic action of polyamines in isolated rat adipocytes.

    PubMed Central

    Richelsen, B; Pedersen, S B; Hougaard, D M

    1989-01-01

    The interactions of polyamines with the lipolytic system were studied in isolated rat adipocytes. Spermine, spermidine and putrescine significantly inhibited adenosine deaminase-stimulated lipolysis. An antilipolytic effect of spermine was detectable at a concentration of 0.25 mM (P less than 0.05). At a concentration of 10 mM all three polyamines inhibited the stimulated lipolysis by 50-60% (P less than 0.001). In addition, spermine enhanced the antilipolytic sensitivity of insulin. Spermine (1 mM) decreased the half-maximal inhibitory concentration of insulin from 320 +/- 70 pM to 56 +/- 20 pM (P less than 0.01). The antilipolytic effects and the cyclic-AMP-lowering effects of the polyamines were almost completely prevented in the presence of different phosphodiesterase (PDE) inhibitors (3-isobutyl-1-methylxanthine and RO 20-1724) and, in addition, polyamines had no effect on lipolysis stimulated by dibutyryl cyclic AMP, indicating that polyamines may inhibit lipolysis by activating the PDE enzyme. This latter suggestion was confirmed by demonstrating that spermine (5 mM) significantly enhanced the low-Km PDE enzyme activity (P less than 0.01). Finally, the amounts of polyamines present in isolated adipocytes were measured, and the estimated cytoplasmic concentrations were 0.02 mM (putrescine), 0.86 mM (spermidine), and 1.0 mM (spermine). It is concluded that polyamines may possibly be involved in the physiological regulation of triacylglycerol mobilization in adipocytes. PMID:2476118

  12. Cortical inhibition and excitation by bilateral transcranial alternating current stimulation.

    PubMed

    Cancelli, Andrea; Cottone, Carlo; Zito, Giancarlo; Di Giorgio, Marina; Pasqualetti, Patrizio; Tecchio, Franca

    2015-01-01

    Transcranial electric stimulations (tES) with amplitude-modulated currents are promising tools to enhance neuromodulation effects. It is essential to select the correct cortical targets and inhibitory/excitatory protocols to reverse changes in specific networks. We aimed at assessing the dependence of cortical excitability changes on the current amplitude of 20 Hz transcranial alternating current stimulation (tACS) over the bilateral primary motor cortex. We chose two amplitude ranges of the stimulations, around 25 μA/cm2 and 63 μA/cm2 from peak to peak, with three values (at steps of about 2.5%) around each, to generate, respectively, inhibitory and excitatory effects of the primary motor cortex. We checked such changes online through transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs). Cortical excitability changes depended upon current density (p = 0.001). Low current densities decreased MEP amplitudes (inhibition) while high current densities increased them (excitation). tACS targeting bilateral homologous cortical areas can induce online inhibition or excitation as a function of the current density.

  13. Development of an Omnidirectional-Capable Electromagnetic Shock Wave Generator for Lipolysis

    PubMed Central

    Lin, San Yih

    2017-01-01

    Traditional methods for adipose tissue removal have progressed from invasive methods such as liposuction to more modern methods of noninvasive lipolysis. This research entails the development and evaluation of an omnidirectional-capable flat-coil electromagnetic shock wave generator (EMSWG) for lipolysis. The developed EMSWG has the advantage of omnidirectional-capable operation. This capability increases the eventual clinical usability by adding three designed supports to the aluminum disk of the EMSWG to allow omnidirectional operation. The focal pressures of the developed EMSWG for different operating voltages were measured, and its corresponding energy intensities were calculated. The developed EMSWG was mounted in a downward orientation for lipolysis and evaluated as proof of concept. In vitro tests on porcine fatty tissues have been carried out. It is found that at a 6 kV operating voltage with 1500 shock wave exposures, a 2 cm thick subcutaneous hypodermis of porcine fatty tissue can be ruptured, resulting in a damaged area of 1.39 mm2. At a 6.5 kV operating voltage with 2000 shock wave exposures, the damaged area is increased to about 5.20 mm2, which can be enlarged by changing the focal point location, resulting in significant lipolysis for use in clinical applications. PMID:29065664

  14. Development of an Omnidirectional-Capable Electromagnetic Shock Wave Generator for Lipolysis.

    PubMed

    Chang, Ming Hau; Lin, San Yih

    2017-01-01

    Traditional methods for adipose tissue removal have progressed from invasive methods such as liposuction to more modern methods of noninvasive lipolysis. This research entails the development and evaluation of an omnidirectional-capable flat-coil electromagnetic shock wave generator (EMSWG) for lipolysis. The developed EMSWG has the advantage of omnidirectional-capable operation. This capability increases the eventual clinical usability by adding three designed supports to the aluminum disk of the EMSWG to allow omnidirectional operation. The focal pressures of the developed EMSWG for different operating voltages were measured, and its corresponding energy intensities were calculated. The developed EMSWG was mounted in a downward orientation for lipolysis and evaluated as proof of concept. In vitro tests on porcine fatty tissues have been carried out. It is found that at a 6 kV operating voltage with 1500 shock wave exposures, a 2 cm thick subcutaneous hypodermis of porcine fatty tissue can be ruptured, resulting in a damaged area of 1.39 mm 2 . At a 6.5 kV operating voltage with 2000 shock wave exposures, the damaged area is increased to about 5.20 mm 2 , which can be enlarged by changing the focal point location, resulting in significant lipolysis for use in clinical applications.

  15. Is transcranial direct current stimulation a potential method for improving response inhibition?☆

    PubMed Central

    Kwon, Yong Hyun; Kwon, Jung Won

    2013-01-01

    Inhibitory control of movement in motor learning requires the ability to suppress an inappropriate action, a skill needed to stop a planned or ongoing motor response in response to changes in a variety of environments. This study used a stop-signal task to determine whether transcranial direct-current stimulation over the pre-supplementary motor area alters the reaction time in motor inhibition. Forty healthy subjects were recruited for this study and were randomly assigned to either the transcranial direct-current stimulation condition or a sham-transcranial direct-current stimulation condition. All subjects consecutively performed the stop-signal task before, during, and after the delivery of anodal transcranial direct-current stimulation over the pre-supplementary motor area (pre-transcranial direct-current stimulation phase, transcranial direct-current stimulation phase, and post-transcranial direct-current stimulation phase). Compared to the sham condition, there were significant reductions in the stop-signal processing times during and after transcranial direct-current stimulation, and change times were significantly greater in the transcranial direct-current stimulation condition. There was no significant change in go processing-times during or after transcranial direct-current stimulation in either condition. Anodal transcranial direct-current stimulation was feasibly coupled to an interactive improvement in inhibitory control. This coupling led to a decrease in the stop-signal process time required for the appropriate responses between motor execution and inhibition. However, there was no transcranial direct-current stimulation effect on the no-signal reaction time during the stop-signal task. Transcranial direct-current stimulation can adjust certain behaviors, and it could be a useful clinical intervention for patients who have difficulties with response inhibition. PMID:25206399

  16. Ex vivo Digestion of Milk from Red Chittagong Cattle Focusing Proteolysis and Lipolysis

    PubMed Central

    Islam, Mohammad Ashiqul; Ekeberg, Dag; Rukke, Elling-Olav; Vegarud, Gerd Elisabeth

    2015-01-01

    Ex vivo digestion of proteins and fat in Red Chittagong Cattle milk from Bangladesh was carried out using human gastrointestinal enzymes. This was done to investigate the protein digestion in this bovine breed’s milk with an especial focus on the degradation of the allergenic milk proteins; αs1-casein and β-lactoglobulin and also to record the generation of peptides. Lipolysis of the milk fat and release of fatty acids were also under consideration. After 40 min of gastric digestion, all the αs-caseins were digested completely while β-lactoglobulin remained intact. During 120 min of duodenal digestion β-lactoglobulin was reduced, however, still some intact β-lactoglobulin was observed. The highest number of peptides was identified from β-casein and almost all the peptides from κ-casein and β-lactoglobulin were identified from the gastric and duodenal samples, respectively. No lipolysis was observed in the gastric phase of digestion. After 120 min of duodenal digestion, milk fat showed 48% lipolysis. Medium (C10:0 to C16:0) and long (≥C17:0) chain fatty acids showed 6% to 19% less lipolysis than the short (C6:0 to C8:0) chain fatty acids. Among the unsaturated fatty acids C18:1∑others showed highest lipolysis (81%) which was more than three times of C18:2∑all and all other unsaturated fatty acids showed lipolysis ranging from 32% to 38%. The overall digestion of Bangladeshi Red Cattle milk was more or less similar to the digestion of Nordic bovine milk (Norwegian Red Cattle). PMID:25656195

  17. Crossed reciprocal inhibition evoked by electrical stimulation of the lamprey spinal cord.

    PubMed

    Fagerstedt, P; Zelenin, P V; Deliagina, T G; Orlovsky, G N; Grillner, S

    2000-09-01

    Activation of a motoneuron pool is often accompanied by inhibition of the antagonistic pool through a system of reciprocal inhibition between the two parts of the neuronal network controlling the antagonistic pools. In the present study, we describe the activity of such a system in the isolated spinal cord of the lamprey, when a tonic motor output is evoked by extracellular stimulation (0.5-1 s train of pulses, 20 Hz) of either end of the spinal cord. With two electrodes symmetrically positioned in relation to the midline, stimulation with either of them separately elicited prolonged (1-5 s) ipsilateral ventral root activity. Activity could be abolished by stronger, simultaneously applied, stimulation of the contralateral side of the cord, suggesting that reciprocal inhibition between hemisegments operates when a tonic motor output is generated. Simultaneous stimulation of both sides of the spinal cord with a single electrode with a large tip (300-400 microm in diameter), positioned over the anatomical midline, elicited inconsistent right-side, leftside, or bilateral ventral root responses. A minor displacement (10-20 microm) to the left or right from the midline resulted in activation of ipsilateral motoneurons, whereas the contralateral motoneurons were silent. These findings indicate that a small asymmetry in the excitatory drive to the left and right spinal hemisegments can be further amplified by reciprocal inhibition between the hemisegments. Longitudinal splitting of the spinal cord along the midline resulted in reduced reciprocal inhibition between the hemisegments separated by the lesion. The reduction was proportional to the extent of the split. The inhibition was abolished when the split reached nine segments in length. From these experiments, the longitudinal distribution of the commissural axons responsible for inhibition of contralateral motor output could be estimated.

  18. Pomegranate inhibits neuroinflammation and amyloidogenesis in IL-1β-stimulated SK-N-SH cells.

    PubMed

    Velagapudi, Ravikanth; Baco, Gina; Khela, Sunjeet; Okorji, Uchechukwu; Olajide, Olumayokun

    2016-06-01

    Pomegranate fruit, Punica granatum L. (Punicaceae), and its constituents have been shown to inhibit inflammation. In this study, we aimed to assess the effects of freeze-dried pomegranate (PWE) on PGE2 production in IL-1β-stimulated SK-N-SH cells. An enzyme immunoassay (EIA) was used to measure prostaglandin E2 (PGE2) production from supernatants of IL-1β-stimulated SK-N-SH cells. Expression of COX-2, phospho-IκB, and phospho-IKK proteins was evaluated, while NF-κB reporter gene assay was carried out in TNFα-stimulated HEK293 cells to determine the effect of PWE on NF-κB transactivation. Levels of BACE-1 and Aβ in SK-N-SH cells stimulated with IL-1β were measured with an in cell ELISA. PWE (25-200 μg/ml) dose dependently reduced COX-2-dependent PGE2 production in SK-N-SH cells stimulated with IL-1β. Phosphorylation of IκB and IKK was significantly (p < 0.001) inhibited by PWE (50-200 μg/ml). Our studies also show that PWE (50-200 μg/ml) significantly (p < 0.01) inhibited NF-κB transactivation in TNFα-stimulated HEK293 cells. Furthermore, PWE inhibited BACE-1 and Aβ expression in SK-N-SH cells treated with IL-1β. Taken together, our study demonstrates that pomegranate inhibits inflammation, as well as amyloidogenesis in IL-1β-stimulated SK-N-SH cells. We propose that pomegranate is a potential nutritional strategy in slowing the progression of neurodegenerative disorders such as Alzheimer's disease.

  19. Lipolysis of Visceral Adipocyte Triglyceride by Pancreatic Lipases Converts Mild Acute Pancreatitis to Severe Pancreatitis Independent of Necrosis and Inflammation

    PubMed Central

    Patel, Krutika; Trivedi, Ram N.; Durgampudi, Chandra; Noel, Pawan; Cline, Rachel A.; DeLany, James P.; Navina, Sarah; Singh, Vijay P.

    2016-01-01

    Visceral fat necrosis has been associated with severe acute pancreatitis (SAP) for over 100 years; however, its pathogenesis and role in SAP outcomes are poorly understood. Based on recent work suggesting that pancreatic fat lipolysis plays an important role in SAP, we evaluated the role of pancreatic lipases in SAP-associated visceral fat necrosis, the inflammatory response, local injury, and outcomes of acute pancreatitis (AP). For this, cerulein pancreatitis was induced in lean and obese mice, alone or with the lipase inhibitor orlistat and parameters of AP induction (serum amylase and lipase), fat necrosis, pancreatic necrosis, and multisystem organ failure, and inflammatory response were assessed. Pancreatic lipases were measured in fat necrosis and were overexpressed in 3T3-L1 cells. We noted obesity to convert mild cerulein AP to SAP with greater cytokines, unsaturated fatty acids (UFAs), and multisystem organ failure, and 100% mortality without affecting AP induction or pancreatic necrosis. Increased pancreatic lipase amounts and activity were noted in the extensive visceral fat necrosis of dying obese mice. Lipase inhibition reduced fat necrosis, UFAs, organ failure, and mortality but not the parameters of AP induction. Pancreatic lipase expression increased lipolysis in 3T3-L1 cells. We conclude that UFAs generated via lipolysis of visceral fat by pancreatic lipases convert mild AP to SAP independent of pancreatic necrosis and the inflammatory response. PMID:25579844

  20. Inhibition of Parkinsonian tremor with cutaneous afferent evoked by transcutaneous electrical nerve stimulation.

    PubMed

    Hao, Man-Zhao; Xu, Shao-Qin; Hu, Zi-Xiang; Xu, Fu-Liang; Niu, Chuan-Xin M; Xiao, Qin; Lan, Ning

    2017-07-14

    Recent study suggests that tremor signals are transmitted by way of multi-synaptic corticospinal pathway. Neurophysiological studies have also demonstrated that cutaneous afferents exert potent inhibition to descending motor commands by way of spinal interneurons. We hypothesize in this study that cutaneous afferents could also affect the transmission of tremor signals, thus, inhibit tremor in patients with PD. We tested this hypothesis by activating cutaneous afferents in the dorsal hand skin innervated by superficial radial nerve using transcutaneous electrical nerve stimulation (TENS). Eight patients with PD having tremor dominant symptom were recruited to participate in this study using a consistent experimental protocol for tremor inhibition. Resting tremor and electromyogram (EMG) of muscles in the upper extremity of these subjects with PD were recorded, while surface stimulation was applied to the dorsal skin of the hand. Fifteen seconds of data were recorded for 5 s prior to, during and post stimulation. Power spectrum densities (PSDs) of tremor and EMG signals were computed for each data segment. The peak values of PSDs in three data segments were compared to detect evidence of tremor inhibition. At stimulation intensity from 1.5 to 1.75 times of radiating sensation threshold, apparent suppressions of tremor at wrist, forearm and upper arm and in the EMGs were observed immediately at the onset of stimulation. After termination of stimulation, tremor and rhythmic EMG bursts reemerged gradually. Statistical analysis of peak spectral amplitudes showed a significant difference in joint tremors and EMGs during and prior to stimulation in all 8 subjects with PD. The average percentage of suppression was 61.56% in tremor across all joints of all subjects, and 47.97% in EMG of all muscles. The suppression appeared to occur mainly in distal joints and muscles. There was a slight, but inconsistent effect on tremor frequency in the 8 patients with PD tested. Our

  1. Charge-balanced biphasic electrical stimulation inhibits neurite extension of spiral ganglion neurons.

    PubMed

    Shen, Na; Liang, Qiong; Liu, Yuehong; Lai, Bin; Li, Wen; Wang, Zhengmin; Li, Shufeng

    2016-06-15

    Intracochlear application of exogenous or transgenic neurotrophins, such as neurotrophin-3 (NT-3) and brain derived neurotrophic factor (BDNF), could promote the resprouting of spiral ganglion neuron (SGN) neurites in deafened animals. These resprouting neurites might reduce the gap between cochlear implant electrodes and their targeting SGNs, allowing for an improvement of spatial resolution of electrical stimulation. This study is to investigate the impact of electrical stimulation employed in CI on the extension of resprouting SGN neurites. We established an in vitro model including the devices delivering charge-balanced biphasic electrical stimulation, and spiral ganglion (SG) dissociated culture treated with BDNF and NT-3. After electrical stimulation with varying durations and intensities, we quantified neurite lengths and Schwann cell densities in SG cultures. Stimulations that were greater than 50μA or longer than 8h significantly decreased SG neurite length. Schwann cell density under 100μA electrical stimulation for 48h was significantly lower compared to that in non-stimulated group. These electrical stimulation-induced decreases of neurite extension and Schwann cell density were attenuated by various types of voltage-dependent calcium channel (VDCC) blockers, or completely prevented by their combination, cadmium or calcium-free medium. Our study suggested that charge-balanced biphasic electrical stimulation inhibited the extension of resprouting SGN neurites and decreased Schwann cell density in vitro. Calcium influx through multiple types of VDCCs was involved in the electrical stimulation-induced inhibition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Histologic evaluation of laser lipolysis comparing continuous wave vs pulsed lasers in an in vivo pig model.

    PubMed

    Levi, Jessica R; Veerappan, Anna; Chen, Bo; Mirkov, Mirko; Sierra, Ray; Spiegel, Jeffrey H

    2011-01-01

    hypothesis. Pulsed lasers with higher peak powers provided better hemostatic effects than CW lasers. The degree of lipolysis depended on wavelength, laser power, and energy density. Subdermal laser irradiation can stimulate collagen deposition in subdermal tissue and reticular dermis.

  3. Quantitative study of lipase secretion, extracellular lipolysis, and lipid storage in the yeast Yarrowia lipolytica grown in the presence of olive oil: analogies with lipolysis in humans.

    PubMed

    Najjar, Amal; Robert, Sylvie; Guérin, Clémence; Violet-Asther, Michèle; Carrière, Frédéric

    2011-03-01

    Lipase secretion, extracellular lipolysis, and fatty acid uptake were quantified in the yeast Yarrowia lipolytica grown in the presence of olive oil and/or glucose. Specific lipase assays, Western blot analysis, and ELISA indicated that most of the lipase activity measured in Y. lipolytica cultures resulted from the YLLIP2 lipase. Lipase production was triggered by olive oil and, during the first hours of culture, most of the lipase activity and YLLIP2 immunodetection remained associated with the yeast cells. YLLIP2 was then released in the culture medium before it was totally degraded by proteases. Olive oil triglycerides were largely degraded when the lipase was still attached to the cell wall. The fate of lipolysis products in the culture medium and inside the yeast cell, as well as lipid storage, was investigated simultaneously by quantitative TLC-FID and GC analysis. The intracellular levels of free fatty acids (FFA) and triglycerides increased transiently and were dependent on the carbon sources. A maximum fat storage of 37.8% w/w of yeast dry mass was observed with olive oil alone. A transient accumulation of saturated FFA was observed whereas intracellular triglycerides became enriched in unsaturated fatty acids. So far, yeasts have been mainly used for studying the intracellular synthesis, storage, and mobilization of neutral lipids. The present study shows that yeasts are also interesting models for studying extracellular lipolysis and fat uptake by the cell. The quantitative data obtained here allow for the first time to establish interesting analogies with gastrointestinal and vascular lipolysis in humans.

  4. Lipolysis stimulating peptides of potato protein hydrolysate effectively suppresses high-fat-diet-induced hepatocyte apoptosis and fibrosis in aging rats.

    PubMed

    Chiang, Wen-Dee; Huang, Chih Yang; Paul, Catherine Reena; Lee, Zong-Yan; Lin, Wan-Teng

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is one of the most common outcomes of obesity and is characterized by the accumulation of triglycerides, increased tissue apoptosis, and fibrosis. NAFLD is more common among elderly than in younger age groups, and it causes serious hepatic complications. In this study, alcalase treatment derived potato protein hydrolysate (APPH) with lipolysis-stimulating property has been evaluated for its efficiency to provide hepato-protection in a high-fat-diet (HFD)-fed aging rats. Twenty-four-month-old SD rats were randomly divided into six groups (n=8): aged rats fed with standard chow, HFD-induced aged obese rats, HFD with low-dose (15 mg/kg/day) APPH treatment, HFD with moderate (45 mg/kg/day) APPH treatment, HFD with high (75 mg/kg/day) APPH treatment, and HFD with probucol. APPH was found to reduce the NAFLD-related effects in rat livers induced by HFD and all of the HFD-fed rats exhibited heavier body weight than those with control chow diet. However, the HFD-induced hepatic fat accumulation was effectively attenuated in rats administered with low (15 mg/kg/day), moderate (45 mg/kg/day), and high (75 mg/kg/day) doses of APPH. APPH oral administration also suppressed the hepatic apoptosis- and fibrosis-related proteins induced by HFD. Our results thus indicate that APPH potentially attenuates hepatic lipid accumulation and anti-apoptosis and fibrosis effects in HFD-induced rats. APPH may have therapeutic potential in the amelioration of NAFLD liver damage.

  5. Branched short-chain fatty acids modulate glucose and lipid metabolism in primary adipocytes

    PubMed Central

    Heimann, Emilia; Nyman, Margareta; Pålbrink, Ann-Ki; Lindkvist-Petersson, Karin; Degerman, Eva

    2016-01-01

    ABSTRACT Short-chain fatty acids (SCFAs), e.g. acetic acid, propionic acid and butyric acid, generated through colonic fermentation of dietary fibers, have been shown to reach the systemic circulation at micromolar concentrations. Moreover, SCFAs have been conferred anti-obesity properties in both animal models and human subjects. Branched SCFAs (BSCFAs), e.g., isobutyric and isovaleric acid, are generated by fermentation of branched amino acids, generated from undigested protein reaching colon. However, BSCFAs have been sparsely investigated when referring to effects on energy metabolism. Here we primarily investigate the effects of isobutyric acid and isovaleric acid on glucose and lipid metabolism in primary rat and human adipocytes. BSCFAs inhibited both cAMP-mediated lipolysis and insulin-stimulated de novo lipogenesis at 10 mM, whereas isobutyric acid potentiated insulin-stimulated glucose uptake by all concentrations (1, 3 and 10 mM) in rat adipocytes. For human adipocytes, only SCFAs inhibited lipolysis at 10 mM. In both in vitro models, BSCFAs and SCFAs reduced phosphorylation of hormone sensitive lipase, a rate limiting enzyme in lipolysis. In addition, BSCFAs and SCFAs, in contrast to insulin, inhibited lipolysis in the presence of wortmannin, a phosphatidylinositide 3-kinase inhibitor and OPC3911, a phosphodiesterase 3 inhibitor in rat adipocytes. Furthermore, BSCFAs and SCFAs reduced insulin-mediated phosphorylation of protein kinase B. To conclude, BSCFAs have effects on adipocyte lipid and glucose metabolism that can contribute to improved insulin sensitivity in individuals with disturbed metabolism. PMID:27994949

  6. Characteristics of an Organizational Environment Which Stimulate and Inhibit Creativity.

    ERIC Educational Resources Information Center

    Alencar, Eunice M. L. Soriano de; Bruno-Faria, Maria de Fatima

    1997-01-01

    Analysis of interviews with 25 Brazilian workers concerning characteristics of a work environment that promote or inhibit creativity identified stimulants (such as organization support, support from bosses, and support from colleagues) and obstacles (such as organization structure, boss characteristics, and personal relationships). (DB)

  7. [Effects of inflammation and stimulant diets on functions of autonomic nervous system (author's transl)].

    PubMed

    Akaeda, H; Nagai, K; Okuda, Y; Shinoto, M; Okuda, H

    1981-06-01

    In usual medical consultation, we have been met a lot of female patients suffering from disturbances of autonomic nervous system such as headache, shoulder-ache and so on. Experiments were designed to elucidate whether or not these disturbances of autonomic nervous system were induced by inflammation and accelerated by stimulant diets. Functions of autonomic nervous system were examined by lipolysis in rat epididymal adipose tissue which was partly controlled by sympathetic nervous system. It was found that free fatty acid release from the epididymal adipose tissue was considerably elevated by inflammation which was formed in abdominal wall or in abdominal cavity or oral administration of stimulant diets such as red pepper and white pepper, and that such elevation of lipolysis was significantly reduced by resection of the autonomic nerve. These results indicated that the inflammation and the stimulant diets induced excitement of sympathetic nerve which controlled the epididymal adipose tissue. Experiments were now in progress to clarify relationship between such excitement of sympathetic nervous system induced by the inflammation or by the stimulant diet and irregular complaints due to disturbances of autonomic nervous system.

  8. Reduced cortical inhibition in violent offenders: a study with transcranial magnetic stimulation.

    PubMed

    Philipp-Wiegmann, Florence; Rösler, Michael; Römer, Konstanze D; Schneider, Marc; Baumgart, Sibylle; Retz, Wolfgang

    2011-01-01

    Aggression and violent behaviour are often regarded as a threat to society. Therefore, understanding violent behaviour has high social relevance. We performed a study with transcranial magnetic stimulation on a sample of violent offenders in order to measure cortical inhibition in the motor neuron system that is part of the frontal cortex. To investigate intracortical inhibition and intracortical facilitation, we conducted paired-pulse stimulation according to the technique of Kujirai and his group (see Method). The investigation sample comprised 62 right-handers: 32 prisoners who had committed severe violent crimes and 30 controls with no history of violence. All subjects were male and matched for age. Using the paired-pulse paradigm with interstimulus intervals (ISI) of 1-15 ms, a reduced cortical inhibition (ISI: 3 ms) was found in the left cortex of violent offenders compared with control subjects. These findings corroborate the hypothesis of inhibition deficits and frontal cortex dysfunction in violent offenders when compared with non-violent control subjects. Copyright © 2011 S. Karger AG, Basel.

  9. The efficacy and safety of cold-induced lipolysis in the treatment of pseudogynecomastia.

    PubMed

    Park, Jung Tae; Kwon, Soon Hyo; Shin, Jung Won; Park, Kyoung Chan; Na, Jung Im; Huh, Chang Hun

    2016-08-01

    The treatment options for pseudogynecomastia have been limited. Cold-induced lipolysis provides a noninvasive, localized subcutaneous adipocyte destruction by inducing adipocyte apoptosis. This study has been designed to evaluate the efficacy of cold-induced lipolysis as a treatment modality for pseudogynecomastia. In this 28-week prospective trial, a total of 12 male pseudogynecomastia patients (Korean) were treated twice with cold-induced lipolysis. Efficacy was determined by chest circumference, ultrasonographic measurement of fat thickness, Simon's Gynecomastia class (SGC), photographic assessment, and the patient's satisfaction (baseline, weeks 4, 8, 16, and 28). Using a questionnaire, safety was evaluated at each visit. For 10 subjects that completed the trial, chest circumference and fat thickness significantly improved by week 8. This same improvement was gradually noticed through week 28. The patients SGC scores continuously decreased after two sessions. Photographic assessment showed an improvement until week 28. The result of the patient's satisfaction score was also meaningful. While there were no adverse events observed, transient pain and bruising at the treatment site were noticed. We recruited a limited number of participants. Also, we could not exclude there might be other individual factors in association with the patients pseudogynecomastia. Cold-induced lipolysis is a safe, effective therapeutic option in the treatment of pseudogynecomastia. Lasers Surg. Med. 48:584-589, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Galanin inhibits caerulein-stimulated pancreatic amylase secretion via cholinergic nerves and insulin.

    PubMed

    Barreto, Savio G; Woods, Charmaine M; Carati, Colin J; Schloithe, Ann C; Jaya, Surendra R; Toouli, James; Saccone, Gino T P

    2009-08-01

    Pancreatic exocrine secretion is affected by galanin, but the mechanisms involved are unclear. We aimed to determine the effect and elucidate the mechanism of action of exogenous galanin on basal and stimulated pancreatic amylase secretion in vitro. The effect of galanin on basal-, carbachol-, and caerulein-stimulated amylase secretion from isolated murine pancreatic lobules was measured. Carbachol and caerulein concentration-response relationships were established. Lobules were coincubated with galanin (10(-12) M to 10(-7) M), carbachol (10(-6) M), or caerulein (10(-10) M). Lobules were preincubated with atropine (10(-5) M), tetrodotoxin (10(-5) M), hexamethonium (10(-5) M), or diazoxide (10(-7) M and 10(-4) M) for 30 min followed by incubation with caerulein (10(-10) M) alone or combined with galanin (10(-12) M). Amylase secretion was expressed as percent of total lobular amylase. Immunohistochemical studies used the antigen retrieval technique and antisera for galanin receptor (GALR) 1, 2, and 3. Carbachol and caerulein stimulated amylase secretion in a concentration-dependent manner with maximal responses of two- and 1.7-fold over control evoked at 10(-6) M and 10(-10) M, respectively. Galanin (10(-12) M) completely inhibited caerulein-stimulated amylase secretion but had no effect on carbachol-stimulated or basal secretion. Atropine and tetrodotoxin pretreatment abolished the caerulein-stimulated amylase secretion, whereas hexamethonium had no significant effect. Diazoxide significantly reduced caerulein-stimulated amylase secretion by approximately 80%. Galanin did not affect caerulein-stimulated amylase secretion in the presence of hexamethonium or diazoxide. Glucose-stimulated amylase secretion was also inhibited by galanin. Immunohistochemistry revealed islet cells labeled for GALR2. These data suggest that galanin may modulate caerulein-stimulated amylase secretion by acting on cholinergic nerves and/or islet cells possibly via GALR2 to regulate insulin

  11. Inhibition of airway surface fluid absorption by cholinergic stimulation

    PubMed Central

    Joo, Nam Soo; Krouse, Mauri E.; Choi, Jae Young; Cho, Hyung-Ju; Wine, Jeffrey J.

    2016-01-01

    In upper airways airway surface liquid (ASL) depth and clearance rates are both increased by fluid secretion. Secretion is opposed by fluid absorption, mainly via the epithelial sodium channel, ENaC. In static systems, increased fluid depth activates ENaC and decreased depth inhibits it, suggesting that secretion indirectly activates ENaC to reduce ASL depth. We propose an alternate mechanism in which cholinergic input, which causes copious airway gland secretion, also inhibits ENaC-mediated absorption. The conjoint action accelerates clearance, and the increased transport of mucus out of the airways restores ASL depth while cleansing the airways. We were intrigued by early reports of cholinergic inhibition of absorption by airways in some species. To reinvestigate this phenomenon, we studied inward short-circuit currents (Isc) in tracheal mucosa from human, sheep, pig, ferret, and rabbit and in two types of cultured cells. Basal Isc was inhibited 20–70% by the ENaC inhibitor, benzamil. Long-lasting inhibition of ENaC-dependent Isc was also produced by basolateral carbachol in all preparations except rabbit and the H441 cell line. Atropine inhibition produced a slow recovery or prevented inhibition if added before carbachol. The mechanism for inhibition was not determined and is most likely multi-factorial. However, its physiological significance is expected to be increased mucus clearance rates in cholinergically stimulated airways. PMID:26846701

  12. Selective inhibition of K(+)-stimulation of Na,K-ATPase by bretylium.

    PubMed Central

    Tiku, P. E.; Nowell, P. T.

    1991-01-01

    1. The effects of bretylium were investigated on purified Na,K-ATPase from guinea-pig heart and on the Na/K pump in trout erythrocytes, with a view to further identifying the mechanism(s) associated with its antiarrhythmic effects. 2. Na,K-ATPase activity of the thiocyanate-dispersed enzyme was determined by the measurement of inorganic phosphate produced by ATP hydrolysis. 3. When the concentrations of each of the Na,K-ATPase activating components were varied in turn, bretylium (1-5 mmol l-1) exhibited competitive-type effects against K+ with a Ki of 1.4 mmol l-1 and noncompetitive-type effects against Na+, Mg2+ and ATP. 4. In K+ influx studies in trout erythrocytes with 86Rb+ used as the marker, the inhibition of total influx observed with bretylium (5 and 10 mmol l-1) was attributable to the bretylium cation selectively inhibiting the Na/K pump-mediated influx with the associated tosylate anion inhibiting Na/K cotransport. 5. The observed inhibition kinetics indicated that the bretylium cation (2-15 mmol l-1) competitively inhibited K+ stimulation of the Na/K pump at 6 and 1.25 mmol l-1 external K+ with a mean K1 of 2.3 mmol l-1. 6. The effects demonstrated on the functioning Na/K pump in erythrocytes confirmed the Na,K-ATPase findings, with bretylium selectively inhibiting K+ stimulation of the pump mechanism in both cases. 7. It is suggested that Na,K-ATPase inhibition may contribute to the antiarrhythmic and positive inotropic effects of bretylium with the cardiac accumulation of bretylium also possibly being a further important factor. PMID:1667290

  13. Brain stem stimulation and the acetylcholine-evoked inhibition of neurones in the feline nucleus reticularis thalami

    PubMed Central

    Dingledine, Raymond; Kelly, J. S.

    1977-01-01

    1. In cats anaesthetized with halothane and nitrous oxide, the responses to iontophoretically applied acetylcholine (ACh) and to high-frequency stimulation of the mid-brain reticular formation (MRF) were tested on spontaneously active neurones in the nucleus reticularis thalami and underlying ventrobasal complex. 2. The initial response to MRF stimulation of 90% of the ACh-inhibited neurones found in the region of the dorsolateral nucleus reticularis was an inhibition. Conversely, the initial response of 82% of the ACh-excited neurones in the ventrobasal complex was an excitation. Neurones in the rostral pole of the nucleus reticularis were inhibited by both ACh and RMF stimulation. 3. The mean latency (and s.e. of mean) for the MRF-evoked inhibition was 13·7 ± 3·2 ms (n = 42) and that for the MRF-evoked excitation, 44.1 ± 4.2 ms (n = 35). 4. The ACh-evoked inhibitions were blocked by iontophoretic atropine, in doses that did not block amino acid-evoked inhibition. In twenty-four ACh-inhibited neurones the effect of iontophoretic atropine was tested on MRF-evoked inhibition. In all twenty-four neurones atropine had no effect on the early phase of MRF-evoked inhibition but weakly antagonized the late phase of inhibition in nine of fourteen neurones. 5. Interspike-interval histograms showed that the firing pattern of neurones in the nucleus reticularis was characterized by periods of prolonged, high-frequency bursting. Both the ACh-evoked inhibitions and the late phase of MRF-evoked inhibitions were accompanied by an increased burst activity. In contrast, iontophoretic atropine tended to suppress burst activity. 6. The possibility is discussed that electrical stimulation of the MRF activates an inhibitory cholinergic projection to the nucleus reticularis. Since neurones of the nucleus reticularis have been shown to inhibit thalamic relay cells, activation of this inhibitory pathway may play a role in MRF-evoked facilitation of thalamo-cortical relay transmission

  14. Antioxidative characteristics and inhibition of alpha-melanocyte-stimulating hormone-stimulated melanogenesis of vanillin and vanillic acid from Origanum vulgare.

    PubMed

    Chou, Tzung-Han; Ding, Hsiou-Yu; Hung, Wei Jing; Liang, Chia-Hua

    2010-08-01

    The antioxidant activities of vanillin and vanillic acid isolated from Origanum vulgare are investigated. These compounds may serve as agents for antimelanogenesis. Vanillic acid is a stronger antioxidant than vanillin, in terms of free radical scavenging activity, reducing power and inhibition of lipid peroxidation. The inhibition of cellular reactive oxygen species (ROS) in H(2)O(2)-treated BNLCL2 cells by vanillic acid exceeds that of ascorbic acid (AA) or trolox. In B16F0 cells stimulated with alpha-melanocyte-stimulating hormone (alpha-MSH), vanillic acid reduced cellular tyrosinase activity, DOPA oxidase and melanin contents, as well as down-regulated expressions of melanocortin-1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related proteins 2 (TRP-2) and TRP-1. Vanillin did not express inhibition of tyrosinase activity. These results supported that vanillic acid is a significantly stronger antioxidant than vanillin and exhibited stronger antimelanogenesis performance because of the structural presence of the carboxyl group.

  15. Apigenin in Combination with Akt Inhibition Significantly Enhances Thyrotropin-Stimulated Radioiodide Accumulation in Thyroid Cells

    PubMed Central

    Lakshmanan, Aparna; Doseff, Andrea I.; Ringel, Matthew D.; Saji, Motoyasu; Rousset, Bernard; Zhang, Xiaoli

    2014-01-01

    Background: Selectively increased radioiodine accumulation in thyroid cells by thyrotropin (TSH) allows targeted treatment of thyroid cancer. However, the extent of TSH-stimulated radioiodine accumulation in some thyroid tumors is not sufficient to confer therapeutic efficacy. Hence, it is of clinical importance to identify novel strategies to selectively further enhance TSH-stimulated thyroidal radioiodine accumulation. Methods: PCCl3 rat thyroid cells, PCCl3 cells overexpressing BRAFV600E, or primary cultured tumor cells from a thyroid cancer mouse model, under TSH stimulation were treated with various reagents for 24 hours. Cells were then subjected to radioactive iodide uptake, kinetics, efflux assays, and protein extraction followed by Western blotting against selected antibodies. Results: We previously reported that Akt inhibition increased radioiodine accumulation in thyroid cells under chronic TSH stimulation. Here, we identified Apigenin, a plant-derived flavonoid, as a reagent to further enhance the iodide influx rate increased by Akt inhibition in thyroid cells under acute TSH stimulation. Akt inhibition is permissive for Apigenin's action, as Apigenin alone had little effect. This action of Apigenin requires p38 MAPK activity but not PKC-δ. The increase in radioiodide accumulation by Apigenin with Akt inhibition was also observed in thyroid cells expressing BRAFV600E and in primary cultured thyroid tumor cells from TRβPV/PV mice. Conclusion: Taken together, Apigenin may serve as a dietary supplement in combination with Akt inhibitors to enhance therapeutic efficacy of radioiodine for thyroid cancer. PMID:24400871

  16. Sulforaphane-stimulated phase II enzyme induction inhibits cytokine production by airway epithelial cells stimulated with diesel extract.

    PubMed

    Ritz, Stacey A; Wan, Junxiang; Diaz-Sanchez, David

    2007-01-01

    Airborne particulate pollutants, such as diesel exhaust particles, are thought to exacerbate lung and cardiovascular diseases through induction of oxidative stress. Sulforaphane, derived from cruciferous vegetables, is the most potent known inducer of phase II enzymes involved in the detoxification of xenobiotics. We postulated that sulforaphane may be able to ameliorate the adverse effects of pollutants by upregulating expression of endogenous antioxidant enzymes. Stimulation of bronchial epithelial cells with the chemical constituents of diesel particles result in the production of proinflammatory cytokines. We first demonstrated a role for phase II enzymes in regulating diesel effects by transfecting the airway epithelial cell line (BEAS-2B) with the sentinel phase II enzyme NAD(P)H: quinine oxidoreductase 1 (NQO1). IL-8 production in response to diesel extract was significantly reduced in these compared with untransfected cells. We then examined whether sulforaphane would stimulate phase II induction and whether this would thereby ablate the effect of diesel extracts on cytokine production. We verified that sulforaphane significantly augmented expression of the phase II enzyme genes GSTM1 and NQO1 and confirmed that sulforaphane treatment increased glutathione S-transferase activity in epithelial cells without inducing cell death or apoptosis. Sulforaphane pretreatment inhibited IL-8 production by BEAS-2B cells upon stimulation with diesel extract. Similarly, whereas diesel extract stimulated production of IL-8, granulocyte-macrophage colony-stimulating factor, and IL-1beta from primary human bronchial epithelial cells, sulforaphane pretreatment inhibited diesel-induced production of all of these cytokines. Our studies show that sulforaphane can mitigate the effect of diesel in respiratory epithelial cells and demonstrate the chemopreventative potential of phase II enzyme enhancement.

  17. In vivo photoacoustic monitoring of anti-obesity photothermal lipolysis

    NASA Astrophysics Data System (ADS)

    Lee, Donghyun; Lee, Jung Ho; Hahn, Sei Kwang; Kim, Chulhong

    2018-02-01

    Obesity with a body mass index is greater than 30 kg/m2 is one of the rapidly growing diseases in advanced societies and can lead to stroke, type 2 diabetes, and heart failure. Common methods of removing subcutaneous adipose tissues are liposuction and laser treatment. In this study, we used photoacoustic imaging to monitor the anti-obesity photothermal degradation process. To improve the photothermal lipid degradation efficiency without any invasive methods, we synthesized hyaluronic acid hollow hold nanosphere adipocyte targeting sequence peptide (HA-HAuNS-ATS) conjugates. The conjugate enhanced the skin penetration ability and biodegradability of the nanoparticles using hyaluronate and enhanced the targeting effect on adipose tissue with adipocyte targeting sequence peptide. Thus, the conjugate can be delivered to the adipose tissue by simply spreading the conjugate on the skin without any invasive method. Then, the photothermal lipolysis and delivery of the conjugate were photoacoustically monitored in vivo. These results demonstrate the potential for photoacoustic method to be applied for photothermal lipolysis monitoring.

  18. The insulin-like effect of vanadate on lipolysis in rat adipocytes is not accompanied by an insulin-like effect on tyrosine phosphorylation.

    PubMed

    Mooney, R A; Bordwell, K L; Luhowskyj, S; Casnellie, J E

    1989-01-01

    Tyrosine phosphorylation of the insulin receptor and other intracellular proteins in rat adipocytes was examined using an immunoblot technique with antiphosphotyrosine antibody. Insulin at 10(-7) M increased the tyrosine phosphorylation of the 95K subunit of the insulin receptor (15-fold) and proteins of 180K (7-fold) and 60K (23-fold). Increases in insulin-dependent phosphorylation of the three proteins were detectable at 10(-10) M insulin and attained steady state within 30 sec of insulin (10(-7) M) addition. Small effects of insulin (less than 30% increases) were observed on proteins of 120K and 53K. In contrast to insulin, the effects of vanadate on tyrosine phosphorylation were small and nonspecific. Vanadate increased tyrosine phosphorylation of the 95K insulin receptor beta-subunit and the 120K and 60K proteins similarly, with increases of 1.5- to 3-fold at 1 mM and 2-fold or less at 200 and 50 microM. Vanadate-dependent tyrosine phosphorylation of the 180K protein increased to a maximum of only 30% at 200 microM. Tyrosine phosphorylation of the 53K protein was somewhat larger, approaching 4-fold at 1 mM vanadate. The concentration of insulin and vanadate that inhibited isoproterenol-dependent lipolysis were not comparable to those that increased tyrosine phosphorylation. Vanadate at 1 mM was more potent as an antilipolytic agent than 10(-9) M insulin (93% vs. 81%), yet increased tyrosine phosphorylation of the 95K insulin receptor beta-subunit only as effectively as 10(-10) M insulin (which inhibited lipolysis only 42%). The dissimilar responses were even more pronounced when antilipolysis was compared to tyrosine phosphorylation of the 180K and 60K proteins. For example, insulin at 10(-9) M increased tyrosine phosphorylation of the 180K protein 2.9-fold, while 1 mM vanadate had a negligible effect (10% increase). Thus, vanadate exerts an insulin-like effect on lipolysis, yet its effects on tyrosine phosphorylation differ from those of insulin.

  19. Inhibition of stimulated Raman scattering due to the excitation of stimulated Brillouin scattering

    NASA Astrophysics Data System (ADS)

    Zhao, Yao; Yu, Lu-Le; Weng, Su-Ming; Ren, Chuang; Liu, Chuan-Sheng; Sheng, Zheng-Ming

    2017-09-01

    The nonlinear coupling between stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) of intense laser in underdense plasma is studied theoretically and numerically. Based upon the fluid model, their coupling equations are derived, and a threshold condition of plasma density perturbations due to SBS for the inhibition of SRS is given. Particle-in-cell simulations show that this condition can be achieved easily by SBS in the so-called fluid regime with kLλD<0.15 , where kL is the Langmuir wave number and λD is the Debye length [Kline et al., Phys. Plasmas 13, 055906 (2006)]. SBS can reduce the saturation level of SRS and the temperature of electrons in both homogeneous and inhomogeneous plasma. Numerical simulations also show that this reduced SRS saturation is retained even if the fluid regime condition mentioned above is violated at a later time due to plasma heating.

  20. Lipolysis - a highly regulated multi-enzyme complex mediates the catabolism of cellular fat stores.

    PubMed

    Lass, Achim; Zimmermann, Robert; Oberer, Monika; Zechner, Rudolf

    2011-01-01

    Lipolysis is the biochemical pathway responsible for the catabolism of triacylglycerol (TAG) stored in cellular lipid droplets. The hydrolytic cleavage of TAG generates non-esterified fatty acids, which are subsequently used as energy substrates, essential precursors for lipid and membrane synthesis, or mediators in cell signaling processes. Consistent with its central importance in lipid and energy homeostasis, lipolysis occurs in essentially all tissues and cell types, it is most abundant, however, in white and brown adipose tissue. Over the last 5years, important enzymes and regulatory protein factors involved in lipolysis have been identified. These include an essential TAG hydrolase named adipose triglyceride lipase (ATGL) [annotated as patatin-like phospholipase domain-containing protein A2], the ATGL activator comparative gene identification-58 [annotated as α/β hydrolase containing protein 5], and the ATGL inhibitor G0/G1 switch gene 2. Together with the established hormone-sensitive lipase [annotated as lipase E] and monoglyceride lipase, these proteins constitute the basic "lipolytic machinery". Additionally, a large number of hormonal signaling pathways and lipid droplet-associated protein factors regulate substrate access and the activity of the "lipolysome". This review summarizes the current knowledge concerning the enzymes and regulatory processes governing lipolysis of fat stores in adipose and non-adipose tissues. Special emphasis will be given to ATGL, its regulation, and physiological function. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. The secreted esterase of Propionibacterium freudenreichii has a major role in cheese lipolysis.

    PubMed

    Abeijón Mukdsi, María Claudia; Falentin, Hélène; Maillard, Marie-Bernadette; Chuat, Victoria; Medina, Roxana Beatriz; Parayre, Sandrine; Thierry, Anne

    2014-01-01

    Free fatty acids are important flavor compounds in cheese. Propionibacterium freudenreichii is the main agent of their release through lipolysis in Swiss cheese. Our aim was to identify the esterase(s) involved in lipolysis by P. freudenreichii. We targeted two previously identified esterases: one secreted esterase, PF#279, and one putative cell wall-anchored esterase, PF#774. To evaluate their role in lipolysis, we constructed overexpression and knockout mutants of P. freudenreichii CIRM-BIA1(T) for each corresponding gene. The sequences of both genes were also compared in 21 wild-type strains. All strains were assessed for their lipolytic activity on milk fat. The lipolytic activity observed matched data previously reported in cheese, thus validating the relevance of the method used. The mutants overexpressing PF#279 or PF#774 released four times more fatty acids than the wild-type strain, demonstrating that both enzymes are lipolytic esterases. However, inactivation of the pf279 gene induced a 75% reduction in the lipolytic activity compared to that of the wild-type strain, whereas inactivation of the pf774 gene did not modify the phenotype. Two of the 21 wild-type strains tested did not display any detectable lipolytic activity. Interestingly, these two strains exhibited the same single-nucleotide deletion at the beginning of the pf279 gene sequence, leading to a premature stop codon, whereas they harbored a pf774 gene highly similar to that of the other strains. Taken together, these results clearly demonstrate that PF#279 is the main lipolytic esterase in P. freudenreichii and a key agent of Swiss cheese lipolysis.

  2. Selective modulation of intracortical inhibition by low-intensity Theta Burst Stimulation.

    PubMed

    McAllister, S M; Rothwell, J C; Ridding, M C

    2009-04-01

    Theta Burst Stimulation (TBS) is a repetitive transcranial magnetic stimulation paradigm which has effects on both excitatory and inhibitory intracortical pathways when applied at an intensity of 80% of active motor threshold. As intracortical inhibitory pathways have a lower threshold for activation than excitatory pathways, we sought to determine whether it was possible to selectively target cortical inhibitory circuitry by reducing the intensity of TBS to 70% of active motor threshold. Motor evoked potentials (MEPs), short latency intracortical facilitation (SICF), intracortical facilitation (ICF) and short interval intracortical inhibition (SICI) were measured at baseline, 5-20 and 20-35 min following continuous (cTBS) and intermittent (iTBS) low-intensity TBS in nine healthy subjects. Low-intensity cTBS significantly reduced SICI 5-20 min following stimulation, whilst having no effect on MEPs, SICF or ICF. Low-intensity iTBS had no effect on SICI, MEPs, SICF or ICF. It is possible to selectively target intracortical inhibitory networks for modulation by low-intensity TBS, however, responses may critically depend upon the particular paradigm chosen. These findings have important implications for the treatment of neurological disorders where abnormal levels of intracortical inhibition are present, such as Parkinson's disease and focal hand dystonia and requires further investigation.

  3. The role of lipolysis in human orosensory fat perception

    PubMed Central

    Voigt, Nadine; Stein, Julia; Galindo, Maria Mercedes; Dunkel, Andreas; Raguse, Jan-Dirk; Meyerhof, Wolfgang; Hofmann, Thomas; Behrens, Maik

    2014-01-01

    Taste perception elicited by food constituents and facilitated by sensory cells in the oral cavity is important for the survival of organisms. In addition to the five basic taste modalities, sweet, umami, bitter, sour, and salty, orosensory perception of stimuli such as fat constituents is intensely investigated. Experiments in rodents and humans suggest that free fatty acids represent a major stimulus for the perception of fat-containing food. However, the lipid fraction of foods mainly consists of triglycerides in which fatty acids are esterified with glycerol. Whereas effective lipolysis by secreted lipases (LIPs) liberating fatty acids from triglycerides in the rodent oral cavity is well established, a similar mechanism in humans is disputed. By psychophysical analyses of humans, we demonstrate responses upon stimulation with triglycerides which are attenuated by concomitant LIP inhibitor administration. Moreover, lipolytic activities detected in minor salivary gland secretions directly supplying gustatory papillae were correlated to individual sensitivities for triglycerides, suggesting that differential LIP levels may contribute to variant fat perception. Intriguingly, we found that the LIPF gene coding for lingual/gastric LIP is not expressed in human lingual tissue. Instead, we identified the expression of other LIPs, which may compensate for the absence of LIPF. PMID:24688103

  4. Antioxidant enzymes stimulation in Aspergillus parasiticus by Lentinula edodes inhibits aflatoxin production.

    PubMed

    Reverberi, M; Fabbri, A A; Zjalic, S; Ricelli, A; Punelli, F; Fanelli, C

    2005-11-01

    Biosynthesis of aflatoxins, toxic metabolites produced by Aspergillus parasiticus, is correlated to the fungal oxidative stress and cell ageing. In this paper, the mechanism underlying the aflatoxin-inhibiting effect of the Lentinula edodes culture filtrates was studied by analysing their anti-oxidant activity and beta-glucan content. Mushroom beta-glucans are pharmacologically active compounds stimulating anti-oxidant responses in animal cells. L. edodes lyophilised filtrates stimulate A. parasiticus anti-oxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) and aflatoxin inhibition was better correlated with beta-glucan content than with anti-oxidant activity of the filtrates. RT-PCR analyses on treated mycelia showed a delay in the activation of aflR, and norA, genes of aflatoxin cluster and a synchronous activation of hsf2-like, a homologue of a yeast transcription factor involved in oxidative stress responses. The first evidence of hsf2-like in A. parasiticus and its activation during aflatoxin biosynthesis is reported. L. edodes filtrates could play a role as external stimulus affecting the anti-oxidant status in the fungal cell that, in turn, leads to aflatoxin inhibition. In the fungal cell, beta-glucans present in the filtrates could stimulate the activation of transcription factors related to anti-oxidant response and anti-oxidant enzyme activity with a contemporaneous delay of aflatoxin genes transcription, which led to a marked reduction of aflatoxin production. This research suggests new perspectives to set suitable strategies against aflatoxins and L. edodes could be considered a promising tool.

  5. The Secreted Esterase of Propionibacterium freudenreichii Has a Major Role in Cheese Lipolysis

    PubMed Central

    Abeijón Mukdsi, María Claudia; Falentin, Hélène; Maillard, Marie-Bernadette; Chuat, Victoria; Medina, Roxana Beatriz; Parayre, Sandrine

    2014-01-01

    Free fatty acids are important flavor compounds in cheese. Propionibacterium freudenreichii is the main agent of their release through lipolysis in Swiss cheese. Our aim was to identify the esterase(s) involved in lipolysis by P. freudenreichii. We targeted two previously identified esterases: one secreted esterase, PF#279, and one putative cell wall-anchored esterase, PF#774. To evaluate their role in lipolysis, we constructed overexpression and knockout mutants of P. freudenreichii CIRM-BIA1T for each corresponding gene. The sequences of both genes were also compared in 21 wild-type strains. All strains were assessed for their lipolytic activity on milk fat. The lipolytic activity observed matched data previously reported in cheese, thus validating the relevance of the method used. The mutants overexpressing PF#279 or PF#774 released four times more fatty acids than the wild-type strain, demonstrating that both enzymes are lipolytic esterases. However, inactivation of the pf279 gene induced a 75% reduction in the lipolytic activity compared to that of the wild-type strain, whereas inactivation of the pf774 gene did not modify the phenotype. Two of the 21 wild-type strains tested did not display any detectable lipolytic activity. Interestingly, these two strains exhibited the same single-nucleotide deletion at the beginning of the pf279 gene sequence, leading to a premature stop codon, whereas they harbored a pf774 gene highly similar to that of the other strains. Taken together, these results clearly demonstrate that PF#279 is the main lipolytic esterase in P. freudenreichii and a key agent of Swiss cheese lipolysis. PMID:24242250

  6. Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes

    PubMed Central

    Zhang, Shiqi; Liu, Guowen; Xu, Chuang; Liu, Lei; Zhang, Qiang; Xu, Qiushi; Jia, Hongdou; Li, Xiaobing; Li, Xinwei

    2018-01-01

    Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1), an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG) synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c) and its target genes, diacylglycerol acyltransferase (DGAT) 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL) and CGI-58 for adipose triglyceride lipase (ATGL), thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows. PMID:29593725

  7. Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes.

    PubMed

    Zhang, Shiqi; Liu, Guowen; Xu, Chuang; Liu, Lei; Zhang, Qiang; Xu, Qiushi; Jia, Hongdou; Li, Xiaobing; Li, Xinwei

    2018-01-01

    Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1), an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG) synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c) and its target genes, diacylglycerol acyltransferase (DGAT) 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL) and CGI-58 for adipose triglyceride lipase (ATGL), thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows.

  8. Cheese milk low homogenization enhanced early lipolysis and volatiles compounds production in hard cooked cheeses.

    PubMed

    Vélez, María A; Hynes, Erica R; Meinardi, Carlos A; Wolf, Verónica I; Perotti, María C

    2017-06-01

    Homogenization applied to cheese milk has shown to increase lipolysis but its use is not spread as it can induce detrimental effects. The aim of this work was to assess the effect of low-pressure homogenization of the cream followed by pre-incubation of cheese milk on the composition, ripening index, lipolysis and volatile profiles of hard cooked cheeses. For that, control and experimental miniature Reggianito cheeses were made and analyzed during ripening (3, 45 and 90days). Homogenization had no impact on composition and proteolysis. An acceleration of the lipolysis reaction was clearly noticed in cheeses made with homogenized milk at the beginning of ripening, while both type of cheeses reached similar levels at 90days. We found the level of several compounds derived from fatty acid catabolism were noticeably influenced by the treatment applied: straight-chain aldehydes such as hexanal, heptanal and nonanal and methylketones from C 5 to C 9 were preferentially formed in experimental cheeses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Simplified assays of lipolysis enzymes for drug discovery and specificity assessment of known inhibitors.

    PubMed

    Iglesias, Jose; Lamontagne, Julien; Erb, Heidi; Gezzar, Sari; Zhao, Shangang; Joly, Erik; Truong, Vouy Linh; Skorey, Kathryn; Crane, Sheldon; Madiraju, S R Murthy; Prentki, Marc

    2016-01-01

    Lipids are used as cellular building blocks and condensed energy stores and also act as signaling molecules. The glycerolipid/ fatty acid cycle, encompassing lipolysis and lipogenesis, generates many lipid signals. Reliable procedures are not available for measuring activities of several lipolytic enzymes for the purposes of drug screening, and this resulted in questionable selectivity of various known lipase inhibitors. We now describe simple assays for lipolytic enzymes, including adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), sn-1-diacylglycerol lipase (DAGL), monoacylglycerol lipase, α/β-hydrolase domain 6, and carboxylesterase 1 (CES1) using recombinant human and mouse enzymes either in cell extracts or using purified enzymes. We observed that many of the reported inhibitors lack specificity. Thus, Cay10499 (HSL inhibitor) and RHC20867 (DAGL inhibitor) also inhibit other lipases. Marked differences in the inhibitor sensitivities of human ATGL and HSL compared with the corresponding mouse enzymes was noticed. Thus, ATGListatin inhibited mouse ATGL but not human ATGL, and the HSL inhibitors WWL11 and Compound 13f were effective against mouse enzyme but much less potent against human enzyme. Many of these lipase inhibitors also inhibited human CES1. Results describe reliable assays for measuring lipase activities that are amenable for drug screening and also caution about the specificity of the many earlier described lipase inhibitors. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

  10. Simplified assays of lipolysis enzymes for drug discovery and specificity assessment of known inhibitors

    PubMed Central

    Iglesias, Jose; Lamontagne, Julien; Erb, Heidi; Gezzar, Sari; Zhao, Shangang; Joly, Erik; Truong, Vouy Linh; Skorey, Kathryn; Crane, Sheldon; Madiraju, S. R. Murthy; Prentki, Marc

    2016-01-01

    Lipids are used as cellular building blocks and condensed energy stores and also act as signaling molecules. The glycerolipid/ fatty acid cycle, encompassing lipolysis and lipogenesis, generates many lipid signals. Reliable procedures are not available for measuring activities of several lipolytic enzymes for the purposes of drug screening, and this resulted in questionable selectivity of various known lipase inhibitors. We now describe simple assays for lipolytic enzymes, including adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), sn-1-diacylglycerol lipase (DAGL), monoacylglycerol lipase, α/β-hydrolase domain 6, and carboxylesterase 1 (CES1) using recombinant human and mouse enzymes either in cell extracts or using purified enzymes. We observed that many of the reported inhibitors lack specificity. Thus, Cay10499 (HSL inhibitor) and RHC20867 (DAGL inhibitor) also inhibit other lipases. Marked differences in the inhibitor sensitivities of human ATGL and HSL compared with the corresponding mouse enzymes was noticed. Thus, ATGListatin inhibited mouse ATGL but not human ATGL, and the HSL inhibitors WWL11 and Compound 13f were effective against mouse enzyme but much less potent against human enzyme. Many of these lipase inhibitors also inhibited human CES1. Results describe reliable assays for measuring lipase activities that are amenable for drug screening and also caution about the specificity of the many earlier described lipase inhibitors. PMID:26423520

  11. IL-15 concentrations in skeletal muscle and subcutaneous adipose tissue in lean and obese humans: local effects of IL-15 on adipose tissue lipolysis

    PubMed Central

    Pierce, Joseph R.; Maples, Jill M.

    2015-01-01

    Animal/cell investigations indicate that there is a decreased adipose tissue mass resulting from skeletal muscle (SkM) IL-15 secretion (e.g., SkM-blood-adipose tissue axis). IL-15 could regulate fat mass accumulation in obesity via lipolysis, although this has not been investigated in humans. Therefore, the purpose was to examine whether SkM and/or subcutaneous adipose tissue (SCAT) IL-15 concentrations were correlated with SCAT lipolysis in lean and obese humans and determine whether IL-15 perfusion could induce lipolysis in human SCAT. Local SkM and abdominal SCAT IL-15 (microdialysis) and circulating IL-15 (blood) were sampled in lean (BMI: 23.1 ± 1.9 kg/m2; n = 10) and obese (BMI: 34.7 ± 3.5 kg/m2; n = 10) subjects at rest/during 1-h cycling exercise. Lipolysis (SCAT interstitial glycerol concentration) was compared against local/systemic IL-15. An additional probe in SCAT was perfused with IL-15 to assess direct lipolytic responses. SkM IL-15 was not different between lean and obese subjects (P = 0.45), whereas SCAT IL-15 was higher in obese vs. lean subjects (P = 0.02) and was correlated with SCAT lipolysis (r = 0.45, P = 0.05). Exercise increased SCAT lipolysis in lean and obese (P < 0.01), but exercise-induced SCAT lipolysis changes were not correlated with exercise-induced SCAT IL-15 changes. Microdialysis perfusion resulting in physiological IL-15 concentrations in the adipose tissue interstitium increased lipolysis in lean (P = 0.04) but suppressed lipolysis in obese (P < 0.01). Although we found no support for a human IL-15 SkM-blood-adipose tissue axis, IL-15 may be produced in/act on the abdominal SCAT depot. The extent to which this autocrine/paracrine IL-15 action regulates human body composition remains unknown. PMID:25921578

  12. Progression of Chronic Kidney Disease Affects HDL Impact on Lipoprotein Lipase (LPL)-Mediated VLDL Lipolysis Efficiency.

    PubMed

    Ćwiklińska, Agnieska; Cackowska, Monika; Wieczorek, Ewa; Król, Ewa; Kowalski, Robert; Kuchta, Agnieszka; Kortas-Stempak, Barbara; Gliwińska, Anna; Dąbkowski, Kamil; Zielińska, Justyna; Dębska-Ślizień, Alicja; Jankowski, Maciej

    2018-06-15

    Hypertriglyceridaemia (HTG) and reduction and dysfunction of high density lipoprotein (HDL) are common lipid disturbances in chronic kidney disease (CKD). HTG in CKD is caused mainly by the decreased efficiency of lipoprotein lipase (LPL)-mediated very low density lipoprotein triglyceride (VLDL-TG) lipolysis. It has not been clarified whether HDL dysfunction in CKD contributes directly to HTG development; thus, the aim of this study was to assess the impact of CKD progression on the ability of HDL to enhance LPL-mediated VLDL-TG lipolysis efficiency. VLDL was isolated from non-dialysis patients in CKD stages 3 and 4 and from non-CKD patients. The VLDL was incubated with LPL at the constant LPL:VLDL-TG ratio, in the absence or presence of HDL. After incubation, the VLDL was separated and the percentage (%) of hydrolyzed TG was calculated. HDL presence increased the lipolysis efficiency of VLDL isolated from CKD and non-CKD patients, for the VLDL-TG> 50 mg/dl. Its effect was dependent on the VLDL-TG and HDL-cholesterol concentrations in the reaction mixtures: the higher the concentrations of VLDL-TG and HDL-cholesterol, the greater the effect. The positive impact of HDL on VLDL lipolysis was modified by CKD progression: the percentage of lipolyzed VLDL-TG in the presence of HDL decreased with a reduction in eGFR (r=0.43, p=0.009), and for patients with stage 4 CKD, no positive impact of HDL on lipolysis was observed. The percentage of lipolyzed TG correlated negatively with apoE and apoCs content in VLDL, and positively with HDL-apoCII, as well as with VLDL and HDL apoCII/ apoCIII ratios. The progression of CKD was associated with unfavourable changes in VLDL and HDL composition; apoE and apoCs levels increased in VLDL with a decrease in eGFR whereas the HDL-cholesterol level decreased. The progression of CKD affects lipoprotein composition and properties, and modulates the positive impact of HDL on VLDL lipolysis efficiency. In CKD patients, HDL deficiency and

  13. Cadmium inhibits acid secretion in stimulated frog gastric mucosa

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gerbino, Andrea, E-mail: gerbino@biologia.uniba.i; Debellis, Lucantonio; Caroppo, Rosa

    2010-06-01

    Cadmium, a toxic environmental pollutant, affects the function of different organs such as lungs, liver and kidney. Less is known about its toxic effects on the gastric mucosa. The aim of this study was to investigate the mechanisms by which cadmium impacts on the physiology of gastric mucosa. To this end, intact amphibian mucosae were mounted in Ussing chambers and the rate of acid secretion, short circuit current (I{sub sc}), transepithelial potential (V{sub t}) and resistance (R{sub t}) were recorded in the continuous presence of cadmium. Addition of cadmium (20 {mu}M to 1 mM) on the serosal but not luminalmore » side of the mucosae resulted in inhibition of acid secretion and increase in NPPB-sensitive, chloride-dependent short circuit current. Remarkably, cadmium exerted its effects only on histamine-stimulated tissues. Experiments with TPEN, a cell-permeant chelator for heavy metals, showed that cadmium acts from the intracellular side of the acid secreting cells. Furthermore, cadmium-induced inhibition of acid secretion and increase in I{sub sc} cannot be explained by an action on: 1) H{sub 2} histamine receptor, 2) Ca{sup 2+} signalling 3) adenylyl cyclase or 4) carbonic anhydrase. Conversely, cadmium was ineffective in the presence of the H{sup +}/K{sup +}-ATPase blocker omeprazole suggesting that the two compounds likely act on the same target. Our findings suggest that cadmium affects the functionality of histamine-stimulated gastric mucosa by inhibiting the H{sup +}/K{sup +}-ATPase from the intracellular side. These data shed new light on the toxic effect of this dangerous environmental pollutant and may result in new avenues for therapeutic intervention in acute and chronic intoxication.« less

  14. The tumor promoter arsenite stimulates AP-1 activity by inhibiting a JNK phosphatase.

    PubMed Central

    Cavigelli, M; Li, W W; Lin, A; Su, B; Yoshioka, K; Karin, M

    1996-01-01

    Trivalent arsenic (As3+) is highly carcinogenic, but devoid of known mutagenic activity. Therefore, it is likely to act as a tumor promoter. To understand the molecular basis for the tumor-promoting activity of As3+, we examined its effect on transcription factor AP-1, whose activity is stimulated by several other tumor promoters. We found that As3+, but not As5+, which is toxic but not carcinogenic, is a potent stimulator of AP-1 transcriptional activity and an efficient inducer of c-fos and c-jun gene expression. Induction of c-jun and c-fos transcription by As3+ correlates with activation of Jun kinases (JNKs) and p38/Mpk2, which phosphorylate transcription factors that activate these immediate early genes. No effect on ERK activity was observed. As5+, on the other hand, had a negligible effect on JNK or p38/Mpk2 activity. Biochemical analysis and co-transfection experiments strongly suggest that the primary mechanism by which As3+ stimulates JNK activity involves the inhibition of a constitutive dual-specificity JNK phosphatase. This phosphatase activity appears to be responsible for maintaining low basal JNK activity in non-stimulated cells and its inhibition may lead to tumor promotion through induction of proto-oncogenes such as c-jun and c-fos, and stimulation of AP-1 activity. The same phosphatase may also regulate p38/Mpk2 activity. Images PMID:8947050

  15. Stimulation of lymphangiogenesis via VEGFR-3 inhibits chronic skin inflammation.

    PubMed

    Huggenberger, Reto; Ullmann, Stefan; Proulx, Steven T; Pytowski, Bronislaw; Alitalo, Kari; Detmar, Michael

    2010-09-27

    The role of lymphangiogenesis in inflammation has remained unclear. To investigate the role of lymphatic versus blood vasculature in chronic skin inflammation, we inhibited vascular endothelial growth factor (VEGF) receptor (VEGFR) signaling by function-blocking antibodies in the established keratin 14 (K14)-VEGF-A transgenic (Tg) mouse model of chronic cutaneous inflammation. Although treatment with an anti-VEGFR-2 antibody inhibited skin inflammation, epidermal hyperplasia, inflammatory infiltration, and angiogenesis, systemic inhibition of VEGFR-3, surprisingly, increased inflammatory edema formation and inflammatory cell accumulation despite inhibition of lymphangiogenesis. Importantly, chronic Tg delivery of the lymphangiogenic factor VEGF-C to the skin of K14-VEGF-A mice completely inhibited development of chronic skin inflammation, epidermal hyperplasia and abnormal differentiation, and accumulation of CD8 T cells. Similar results were found after Tg delivery of mouse VEGF-D that only activates VEGFR-3 but not VEGFR-2. Moreover, intracutaneous injection of recombinant VEGF-C156S, which only activates VEGFR-3, significantly reduced inflammation. Although lymphatic drainage was inhibited in chronic skin inflammation, it was enhanced by Tg VEGF-C delivery. Together, these results reveal an unanticipated active role of lymphatic vessels in controlling chronic inflammation. Stimulation of functional lymphangiogenesis via VEGFR-3, in addition to antiangiogenic therapy, might therefore serve as a novel strategy to treat chronic inflammatory disorders of the skin and possibly also other organs.

  16. Methadone but not morphine inhibits lubiprostone-stimulated Cl- currents in T84 intestinal cells and recombinant human ClC-2, but not CFTR Cl- currents.

    PubMed

    Cuppoletti, John; Chakrabarti, Jayati; Tewari, Kirti; Malinowska, Danuta H

    2013-05-01

    In clinical trials, methadone, but not morphine, appeared to prevent beneficial effects of lubiprostone, a ClC-2 Cl(-) channel activator, on opioid-induced constipation. Effects of methadone and morphine on lubiprostone-stimulated Cl(-) currents were measured by short circuit current (Isc) across T84 cells. Whole cell patch clamp of human ClC-2 (hClC-2) stably expressed in HEK293 cells and in a high expression cell line (HEK293EBNA) as well as human CFTR (hCFTR) stably expressed in HEK293 cells was used to study methadone and morphine effects on recombinant hClC-2 and hCFTR Cl(-) currents. Methadone but not morphine inhibited lubiprostone-stimulated Isc in T84 cells with half-maximal inhibition at 100 nM. Naloxone did not affect lubiprostone stimulation or methadone inhibition of Isc. Lubiprostone-stimulated Cl(-) currents in hClC-2/HEK293 cells, but not forskolin/IBMX-stimulated Cl(-) currents in hCFTR/HEK293 cells, were inhibited by methadone, but not morphine. HEK293EBNA cells expressing hClC-2 showed time-dependent, voltage-activated, CdCl2-inhibited Cl(-) currents in the absence (control) and the presence of lubiprostone. Methadone, but not morphine, inhibited control and lubiprostone-stimulated hClC-2 Cl(-) currents with half-maximal inhibition at 100 and 200-230 nM, respectively. Forskolin/IBMX-stimulated hClC-2 Cl(-) currents were also inhibited by methadone. Myristoylated protein kinase inhibitor (a specific PKA inhibitor) inhibited forskolin/IBMX- but not lubiprostone-stimulated hClC-2 Cl(-) currents. Methadone caused greater inhibition of lubiprostone-stimulated currents added before patching (66.1 %) compared with after patching (28.7 %). Methadone caused inhibition of lubiprostone-stimulated Cl(-) currents in T84 cells and control; lubiprostone- and forskolin/IBMX-stimulated recombinant hClC-2 Cl(-) currents may be the basis for reduced efficacy of lubiprostone in methadone-treated patients.

  17. Controlling insulin release from reverse hexagonal (HII) liquid crystalline mesophase by enzymatic lipolysis.

    PubMed

    Mishraki-Berkowitz, Tehila; Cohen, Guy; Aserin, Abraham; Garti, Nissim

    2018-01-01

    In the present study we aimed to control insulin release from the reverse hexagonal (H II ) mesophase using Thermomyces lanuginosa lipase (TLL) in the environment (outer TLL) or within the H II cylinders (inner TLL). Two insulin-loaded systems differing by the presence (or absence) of phosphatidylcholine (PC) were examined. In general, incorporation of PC into the H II interface (without TLL) increased insulin release, as a more cooperative system was formed. Addition of TLL to the systems' environments resulted in lipolysis of the H II structure. In the absence of PC, the lipolysis was more dominant and led to a significant increase in insulin release (50% after 8h). However, the presence of PC stabilized the interface, hindering the lipolysis, and therefore no impact on the release profile was detected during the first 8h. Entrapment of TLL within the H II cylinders (with and without PC) drastically increased insulin release in both systems up to 100%. In the presence of PC insulin released faster and the structure was more stable. Consequently, the presence of lipases (inner or outer) both enhanced the destruction of the carrier, and provided sustained release of the entrapped insulin. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Design and synthesis of aryloxypropanolamine as β3-adrenergic receptor antagonist in cancer and lipolysis.

    PubMed

    Jin, Jiyu; Miao, Chunxiao; Wang, Zhilong; Zhang, Wanli; Zhang, Xiongwen; Xie, Xin; Lu, Wei

    2018-04-25

    β-adrenergic receptors (β-ARs) are broadly distributed in various tissues and regulate a panel of important physiological functions and disease states including cancer. Above all, β 3 -adrenergic receptor (β 3 -AR) plays a significant role in regulating lipolysis and thermogenesis in adipose tissue. In this study, we designed and synthesized a series of novel L-748,337 derivatives as selective human β 3 -AR antagonists. Among all the tested L-748,337 analogs, compound 23d was found to display 23-fold more potent β 3 -AR antagonist activity (EC 50  = 0.5117 nM) than L-748,337 (EC 50  = 11.91 nM). In vivo, compound 23d could alleviate weight loss and inhibit tumor growth in C26 tumor cachexia animal model. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  19. Impact of gastrointestinal lipolysis on oral lipid-based formulations and bioavailability of lipophilic drugs.

    PubMed

    Carrière, Frédéric

    2016-06-01

    Oil-in-water emulsions are common vehicles for lipids as nutrients and for the delivery of poorly water-soluble drugs. Enhancing oral bioavailability of these drugs using lipid-based formulations (LBF) or self-emulsifying drug delivery systems is one of the current challenges in pharmaceutical industry. Many of the compounds found in LBF (acylglycerols, surfactants with esterified fatty acids, …) are however potential substrates for digestive enzymes. Their digestion (or lipolysis) in the gastrointestinal (GI) tract is critical for drug dissolution and absorption: it can be beneficial (drug solubilization/dispersion) or deleterous (drug precipitation) depending on the drug-LBF association. A better understanding of the fate of LBF in the GI tract is therefore required to engineer efficient lipid-based drug delivery systems. In vitro models for testing simultaneously LBF digestion and drug dispersion are in development to predict drug solubilization and bioavailability, select the best drug-LBF association and obtain better in vitro-in vivo correlations. So far, research in this area has focused on LBF lipolysis under intestinal conditions because the small intestine is the main target for drug delivery and absorption, as well as the main site of digestion by pancreatic enzymes. Lipolysis however starts within the stomach through the action of gastric lipase, the first enzyme involved in fat digestion in humans. In vitro digestion experiments show that most LBFs are submitted to gastric lipolysis, and therefore, both intragastric and intestinal digestions are critical for the fate of LBF and drug solubility. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. Deep brain stimulation mechanisms: beyond the concept of local functional inhibition.

    PubMed

    Deniau, Jean-Michel; Degos, Bertrand; Bosch, Clémentine; Maurice, Nicolas

    2010-10-01

    Deep brain electrical stimulation has become a recognized therapy in the treatment of a variety of motor disorders and has potentially promising applications in a wide range of neurological diseases including neuropsychiatry. Behavioural observation that electrical high-frequency stimulation of a given brain area induces an effect similar to a lesion suggested a mechanism of functional inhibition. In vitro and in vivo experiments as well as per operative recordings in patients have revealed a variety of effects involving local changes of neuronal excitability as well as widespread effects throughout the connected network resulting from activation of axons, including antidromic activation. Here we review current data regarding the local and network activity changes induced by high-frequency stimulation of the subthalamic nucleus and discuss this in the context of motor restoration in Parkinson's disease. Stressing the important functional consequences of axonal activation in deep brain stimulation mechanisms, we highlight the importance of developing anatomical knowledge concerning the fibre connections of the putative therapeutic targets. © 2010 The Authors. European Journal of Neuroscience © 2010 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  1. [Laser-assisted lipolysis for gynecomastia: safe and effective skin retraction].

    PubMed

    Trelles, Mario; Bonanad, Enrique; Moreno-Moraga, Javier; Alcolea, Justo; Mordon, Serge; Leclère, Franck Marie

    2013-01-01

    To evaluate efficacy of laser lipolysis in the treatment of gynecomastia to correct breast volume, flaccidity and excess skin without its excision. Prospectively, 32 patients with gynecomastia under tumescent anaesthesia and sedation underwent laser lipolysis with 980 nm diode laser, 15W continuous emission and 8 to 12 kJ energy per breast. Externally cold air was used to protect the skin. No drainages were used but a compressive bandage. Patients evaluated results on a VAS scale. Two doctors evaluated results comparing before and 6 month after photographs and also measured the areola and chest diameter. Twenty three patients considered results as Very Good, 7 Good and 2 Fair Cutaneous retraction of the areola was noticeable one month after the surgery and was maximum 6 months after. Evaluation by doctors was 26 Very Good, 5 Good and 1 Fair. There were no burns, ischemia or lesions in areolas or nipples. Laser assisted liposuction is a simple and efficacious technique, barely traumatic and permits a rapid reincorporation to normal activities.

  2. The relief of microtherm inhibition for p-fluoronitrobenzene mineralization using electrical stimulation at low temperatures.

    PubMed

    Zhang, Xueqin; Feng, Huajun; Liang, Yuxiang; Zhao, Zhiqing; Long, Yuyang; Fang, Yuan; Wang, Meizhen; Yin, Jun; Shen, Dongsheng

    2015-05-01

    Low temperature aggravates biological treatment of refractory p-fluoronitrobenzene (p-FNB) because of microtherm inhibition of microbial activity. Considering the potential characterization of energy supply for microbial metabolism and spurring microbial activity by electrical stimulation, a bioelectrochemical system (BES) was established to provide sustaining electrical stimulation for p-FNB mineralization at a low temperature. Electrical stimulation facilitated p-FNB treatment and bioelectrochemical reaction rate constants for the removal and defluorination of p-FNB at 10 °C were 0.0931 and 0.0054 h(-1), which were higher than the sums of the rates found using a biological system and an electrocatalytic system by 62.8 and 64.8%, respectively. At a low temperature, microbial activity in terms of dehydrogenase and ATPase was found to be higher with electrical stimulation, being 121.1 and 100.1% more active than that in the biological system. Moreover, stronger antioxidant ability was observed in the BES, which implied a better cold-resistance and relief of microtherm inhibition by electrical stimulation. Bacterial diversity analysis revealed a significant evolution of microbial community by electrical stimulation, and Clostridia was uniquely enriched. One bacterial sequence close to Pseudomonas became uniquely predominant, which appeared to be crucial for excellent p-FNB treatment performance in the BES at a low temperature. Economic evaluation revealed that the energy required to mineralize an extra mole of p-FNB was found to be 247 times higher by heating the system than by application of electrical stimulation. These results indicated that application of electrical stimulation is extremely promising for treating refractory waste at low temperatures.

  3. β-Adrenergic receptor stimulation inhibits proarrhythmic alternans in postinfarction border zone cardiomyocytes: a computational analysis.

    PubMed

    Tomek, Jakub; Rodriguez, Blanca; Bub, Gil; Heijman, Jordi

    2017-08-01

    The border zone (BZ) of the viable myocardium adjacent to an infarct undergoes extensive autonomic and electrical remodeling and is prone to repolarization alternans-induced cardiac arrhythmias. BZ remodeling processes may promote or inhibit Ca 2+ and/or repolarization alternans and may differentially affect ventricular arrhythmogenesis. Here, we used a detailed computational model of the canine ventricular cardiomyocyte to study the determinants of alternans in the BZ and their regulation by β-adrenergic receptor (β-AR) stimulation. The BZ model developed Ca 2+ transient alternans at slower pacing cycle lengths than the control model, suggesting that the BZ may promote spatially heterogeneous alternans formation in an infarcted heart. β-AR stimulation abolished alternans. By evaluating all combinations of downstream β-AR stimulation targets, we identified both direct (via ryanodine receptor channels) and indirect [via sarcoplasmic reticulum (SR) Ca 2+ load] modulation of SR Ca 2+ release as critical determinants of Ca 2+ transient alternans. These findings were confirmed in a human ventricular cardiomyocyte model. Cell-to-cell coupling indirectly modulated the likelihood of alternans by affecting the action potential upstroke, reducing the trigger for SR Ca 2+ release in one-dimensional strand simulations. However, β-AR stimulation inhibited alternans in both single and multicellular simulations. Taken together, these data highlight a potential antiarrhythmic role of sympathetic hyperinnervation in the BZ by reducing the likelihood of alternans and provide new insights into the underlying mechanisms controlling Ca 2+ transient and repolarization alternans. NEW & NOTEWORTHY We integrated, for the first time, postmyocardial infarction electrical and autonomic remodeling in a detailed, validated computer model of β-adrenergic stimulation in ventricular cardiomyocytes. Here, we show that β-adrenergic stimulation inhibits alternans and provide novel insights

  4. Arylacetamide deacetylase: a novel host factor with important roles in the lipolysis of cellular triacylglycerol stores, VLDL assembly and HCV production.

    PubMed

    Nourbakhsh, Mahra; Douglas, Donna N; Pu, Christopher Hao; Lewis, Jamie T; Kawahara, Toshiyasu; Lisboa, Luiz F; Wei, Enhui; Asthana, Sonal; Quiroga, Ariel D; Law, Lok Man John; Chen, Chao; Addison, William R; Nelson, Randy; Houghton, Michael; Lehner, Richard; Kneteman, Norman M

    2013-08-01

    Very low density lipoproteins (VLDLs) are triacylglycerol (TG)-rich lipoproteins produced by the human liver. VLDLs derive the majority of their TG cargo from the lipolysis of TG stored in hepatocellular lipid droplets (LDs). Important roles for LDs and the VLDL secretory pathway in the cell culture production of infectious hepatitis C virus (HCV) have been established. We hypothesized that TG lipolysis and VLDL production are impaired during HCV infection so that these cellular processes can be diverted towards HCV production. We used an HCV permissive cell culture system (JFH-1/HuH7.5 cells) to examine the relationship between TG lipolysis, VLDL assembly, and the HCV lifecycle using standard biochemical approaches. Lipolysis of cellular TG and VLDL production were impaired in HCV infected cells during the early peak of viral infection. This was partially explained by an apparent deficiency of a putative TG lipase, arylacetamide deacetylase (AADAC). The re-introduction of AADAC to infected cells restored cellular TG lipolysis, indicating a role for HCV-mediated downregulation of AADAC in this process. Defective lipolysis of cellular TG stores and VLDL production were also observed in HuH7.5 cells stably expressing a short hairpin RNA targeting AADAC expression, proving AADAC deficiency contributes to these defective pathways. Finally, impaired production of HCV was observed with AADAC knockdown cells, demonstrating a role for AADAC in the HCV lifecycle. This insight into the biology of HCV infection and possibly pathogenesis identifies AADAC as a novel and translationally relevant therapeutic target. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  5. Influence of transcutaneous electrical nerve stimulation conditions on disynaptic reciprocal Ia inhibition and presynaptic inhibition in healthy adults.

    PubMed

    Takeda, Kazuya; Tanabe, Shigeo; Koyama, Soichiro; Ushiroyama, Kosuke; Naoi, Yuki; Motoya, Ikuo; Sakurai, Hiroaki; Kanada, Yoshikiyo

    2017-03-01

    This study investigated the influence of stimulus conditions of transcutaneous electrical nerve stimulation (TENS) on disynaptic reciprocal Ia inhibition (RI) and presynaptic inhibition (D1 inhibition) in healthy adults. Eight healthy participants received TENS (stimulus frequencies of 50, 100, and 200 Hz) over the deep peroneal nerve and tibialis anterior (TA) muscle in the resting condition for 30 min. At pre- and post-intervention, the RI from the TA to the soleus (SOL) and D1 inhibition of the SOL alpha motor neuron were assessed by evoked electromyography. The results showed that RI was not changed by TENS at any stimulus frequency condition. Conversely, D1 inhibition was significantly changed by TENS regardless of the stimulus frequency. The present results and previous studies pertaining to RI suggest that the resting condition might strongly influence the lack of pre- vs. post-intervention change in the RI. Regarding the D1 inhibition, the present results suggest that the effect of TENS might be caused by post-tetanic potentiation. The knowledge gained from the present study might contribute to a better understanding of fundamental studies of TENS in healthy adults and its clinical application for stroke survivors.

  6. Symposium review: Modulating adipose tissue lipolysis and remodeling to improve immune function during the transition period and early lactation of dairy cows.

    PubMed

    Contreras, G Andres; Strieder-Barboza, Clarissa; De Koster, Jenne

    2018-03-01

    Despite major advances in our understanding of transition and early lactation cow physiology and the use of advanced dietary, medical, and management tools, at least half of early lactation cows are reported to develop disease and over half of cow deaths occur during the first week of lactation. Excessive lipolysis, usually measured as plasma concentrations of free fatty acids (FFA), is a major risk factor for the development of displaced abomasum, ketosis, fatty liver, and metritis, and may also lead to poor lactation performance. Lipolysis triggers adipose tissue (AT) remodeling that is characterized by enhanced humoral and cell-mediated inflammatory responses and changes in its distribution of cellular populations and extracellular matrix composition. Uncontrolled AT inflammation could perpetuate lipolysis, as we have observed in cows with displaced abomasum, especially in those animals with genetic predisposition for excessive lipolysis responses. Efficient transition cow management ensures a moderate rate of lipolysis that is rapidly reduced as lactation progresses. Limiting FFA release from AT benefits immune function as several FFA are known to promote dysregulation of inflammation. Adequate formulation of pre- and postpartum diet reduces the intensity of AT lipolysis. Additionally, supplementation with niacin, monensin, and rumen-protected methyl donors (choline and methionine) during the transition period is reported to minimize FFA release into systemic circulation. Targeted supplementation of energy sources during early lactation improves energy balance and increases insulin concentration, which limits AT lipolytic responses. This review elaborates on the mechanisms by which uncontrolled lipolysis triggers inflammatory disorders. Details on current nutritional and pharmacological interventions that aid the modulation of FFA release from AT and their effect on immune function are provided. Understanding the inherent characteristics of AT biology in

  7. Theta burst magnetic stimulation over the pre-supplementary motor area improves motor inhibition.

    PubMed

    Obeso, Ignacio; Wilkinson, Leonora; Teo, James T; Talelli, Penelope; Rothwell, John C; Jahanshahi, Marjan

    Stopping an ongoing motor response or resolving conflict induced by conflicting stimuli are associated with activation of a right-lateralized network of inferior frontal gyrus (IFG), pre-supplementary motor area (pre-SMA) and subthalamic nucleus (STN). However, the roles of the right IFG and pre-SMA in stopping a movement and in conflict resolution remain unclear. We used continuous theta burst stimulation (cTBS) to examine the involvement of the right IFG and pre-SMA in inhibition and conflict resolution using the conditional stop signal task. We measured stop signal reaction time (SSRT, measure of reactive inhibition), response delay effect (RDE, measure of proactive action restraint) and conflict induced slowing (CIS, measure of conflict resolution). Stimulation over the pre-SMA resulted in significantly shorter SSRTs (improved inhibition) compared to sham cTBS. This effect was not observed for CIS, RDE, or any other measures. cTBS over the right IFG had no effect on SSRT, CIS, RDE or on any other measure. The improvement of SSRT with cTBS over the pre-SMA suggests its critical contribution to stopping ongoing movements. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Sodium acetate decreases phosphorylation of hormone sensitive lipase in isoproterenol-stimulated 3T3-L1 mature adipocytes

    PubMed Central

    Aberdein, Nicola; Schweizer, Michael; Ball, Derek

    2014-01-01

    Lipolysis, the process of hydrolysis of stored triacylglycerol into glycerol and non-esterified fatty acids (NEFA), is reported to be reduced by short chain fatty acids (SCFA) but the mechanism of this inhibition is poorly understood. The aim of this study was to measure the phosphorylation at serine residue 563 of hormone sensitive lipase with and without exposure to sodium acetate. Using the 3T3-L1 cell line, we identified that stimulating the cells with isoproterenol increased phosphorylated hormone sensitive lipase (pHSL) expression by 60% compared with the basal state. In the presence of the SCFA acetate in stimulated cells, pHSL decreased by 15% compared with stimulated cells alone. These results were mirrored by the NEFA release from stimulated cells that had significantly decreased in the presence of sodium acetate after 60 min (from 0.53 µmol mg−1 protein to 0.41 µmol mg−1 protein, respectively, P = 0.004); and 180 min (1.73 µmol mg−1 protein to 1.13 µmol mg−1 protein, P = 0.020); however, treatment had no effect on glycerol release (P = 0.109). In conclusion, exposure to 4 mM acetate reduced the level of phosphorylation of HSL(SER563) in mature 3T3-L1 adipocytes and led to a significant reduction in NEFA release, although glycerol release was not affected. PMID:24719785

  9. (S)-[6]-Gingerol inhibits TGF-β-stimulated biglycan synthesis but not glycosaminoglycan hyperelongation in human vascular smooth muscle cells.

    PubMed

    Kamato, Danielle; Babaahmadi Rezaei, Hossein; Getachew, Robel; Thach, Lyna; Guidone, Daniel; Osman, Narin; Roufogalis, Basil; Duke, Colin C; Tran, Van Hoan; Zheng, Wenhua; Little, Peter J

    2013-07-01

    (S)-[6]-Gingerol is under investigation for a variety of therapeutic uses. Transforming growth factor (TGF)-β stimulates proteoglycan synthesis, leading to increased binding of low-density lipoproteins, which is the initiating step in atherosclerosis. We evaluated the effects of (S)-[6]-gingerol on these TGF-β-mediated proteoglycan changes to explore its potential as an anti-atherosclerotic agent. Purified (S)-[6]-gingerol was assessed for its effects on proteoglycan synthesis by [(35) S]-sulfate incorporation into glycosaminoglycan chains and [(35) S]-Met/Cys incorporation into proteoglycans and total proteins in human vascular smooth muscle cells. Biglycan level was assessed by real-time quantitative polymerase chain reactions and the effects of (S)-[6]-gingerol on TGF-β signalling by assessment of the phosphorylation of Smads and Akt by western blotting. (S)-[6]-Gingerol concentration-dependently inhibited TGF-β-stimulated proteoglycan core protein synthesis, and this was not secondary to inhibition of total protein synthesis. (S)-[6]-Gingerol inhibited biglycan mRNA expression. (S)-[6]-Gingerol did not inhibit TGF-β-stimulated glycosaminoglycan hyperelongation or phosphorylation of Smad 2, in either the carboxy terminal or linker region, or Akt phosphorylation. The activity of (S)-[6]-gingerol to inhibit TGF-β-stimulated biglycan synthesis suggests a potential role for ginger in the prevention of atherosclerosis or other lipid-binding diseases. The signalling studies indicate a novel site of action of (S)-[6]-gingerol in inhibiting TGF-β responses. © 2013 Royal Pharmaceutical Society.

  10. Human ovarian cancer stem/progenitor cells are stimulated by doxorubicin but inhibited by Mullerian inhibiting substance

    PubMed Central

    Meirelles, Katia; Benedict, Leo Andrew; Dombkowski, David; Pepin, David; Preffer, Frederic I.; Teixeira, Jose; Tanwar, Pradeep Singh; Young, Robert H.; MacLaughlin, David T.; Donahoe, Patricia K.; Wei, Xiaolong

    2012-01-01

    Women with late-stage ovarian cancer usually develop chemotherapeutic-resistant recurrence. It has been theorized that a rare cancer stem cell, which is responsible for the growth and maintenance of the tumor, is also resistant to conventional chemotherapeutics. We have isolated from multiple ovarian cancer cell lines an ovarian cancer stem cell-enriched population marked by CD44, CD24, and Epcam (3+) and by negative selection for Ecadherin (Ecad−) that comprises less than 1% of cancer cells and has increased colony formation and shorter tumor-free intervals in vivo after limiting dilution. Surprisingly, these cells are not only resistant to chemotherapeutics such as doxorubicin, but also are stimulated by it, as evidenced by the significantly increased number of colonies in treated 3+Ecad− cells. Similarly, proliferation of the 3+Ecad− cells in monolayer increased with treatment, by either doxorubicin or cisplatin, compared with the unseparated or cancer stem cell-depleted 3−Ecad+ cells. However, these cells are sensitive to Mullerian inhibiting substance (MIS), which decreased colony formation. MIS inhibits ovarian cancer cells by inducing G1 arrest of the 3+Ecad− subpopulation through the induction of cyclin-dependent kinase inhibitors. 3+Ecad− cells selectively expressed LIN28, which colocalized by immunofluorescence with the 3+ cancer stem cell markers in the human ovarian carcinoma cell line, OVCAR-5, and is also highly expressed in transgenic murine models of ovarian cancer and in other human ovarian cancer cell lines. These results suggest that chemotherapeutics may be stimulative to cancer stem cells and that selective inhibition of these cells by treating with MIS or targeting LIN28 should be considered in the development of therapeutics. PMID:22308459

  11. Human ovarian cancer stem/progenitor cells are stimulated by doxorubicin but inhibited by Mullerian inhibiting substance.

    PubMed

    Meirelles, Katia; Benedict, Leo Andrew; Dombkowski, David; Pepin, David; Preffer, Frederic I; Teixeira, Jose; Tanwar, Pradeep Singh; Young, Robert H; MacLaughlin, David T; Donahoe, Patricia K; Wei, Xiaolong

    2012-02-14

    Women with late-stage ovarian cancer usually develop chemotherapeutic-resistant recurrence. It has been theorized that a rare cancer stem cell, which is responsible for the growth and maintenance of the tumor, is also resistant to conventional chemotherapeutics. We have isolated from multiple ovarian cancer cell lines an ovarian cancer stem cell-enriched population marked by CD44, CD24, and Epcam (3+) and by negative selection for Ecadherin (Ecad-) that comprises less than 1% of cancer cells and has increased colony formation and shorter tumor-free intervals in vivo after limiting dilution. Surprisingly, these cells are not only resistant to chemotherapeutics such as doxorubicin, but also are stimulated by it, as evidenced by the significantly increased number of colonies in treated 3+Ecad- cells. Similarly, proliferation of the 3+Ecad- cells in monolayer increased with treatment, by either doxorubicin or cisplatin, compared with the unseparated or cancer stem cell-depleted 3-Ecad+ cells. However, these cells are sensitive to Mullerian inhibiting substance (MIS), which decreased colony formation. MIS inhibits ovarian cancer cells by inducing G1 arrest of the 3+Ecad- subpopulation through the induction of cyclin-dependent kinase inhibitors. 3+Ecad- cells selectively expressed LIN28, which colocalized by immunofluorescence with the 3+ cancer stem cell markers in the human ovarian carcinoma cell line, OVCAR-5, and is also highly expressed in transgenic murine models of ovarian cancer and in other human ovarian cancer cell lines. These results suggest that chemotherapeutics may be stimulative to cancer stem cells and that selective inhibition of these cells by treating with MIS or targeting LIN28 should be considered in the development of therapeutics.

  12. Role of white adipose lipolysis in the development of NASH induced by methionine-and choline-deficient diet

    PubMed Central

    Tanaka, Naoki; Takahashi, Shogo; Fang, Zhong-Ze; Matsubara, Tsutomu; Krausz, Kristopher W.; Qu, Aijuan; Gonzalez, Frank J.

    2014-01-01

    Methionine- and choline-deficient diet (MCD) is a model for nonalcoholic steatohepatitis (NASH) in rodents. However, the mechanism of NASH development by dietary methionine/choline deficiency remains undetermined. To elucidate the early metabolic changes associated with MCD-NASH, serum metabolomic analysis was performed using mice treated with MCD and control diet for three days and one week, revealing significant increases in oleic and linoleic acids after MCD treatment. These increases were correlated with reduced body weight and white adipose tissue (WAT) mass, increased phosphorylation of hormone-sensitive lipase, and up-regulation of genes encoding carboxylesterase 3 and β2-adrenergic receptor in WAT, indicating accelerated lipolysis in adipocytes. The changes in serum fatty acids and WAT by MCD treatment were reversed by methionine supplementation, and similar alterations were detected in mice fed a methionine-deficient diet (MD), thus demonstrating that dietary methionine deficiency enhances lipolysis in WAT. MD treatment decreased glucose and increased fibroblast growth factor 21 in serum, thus exhibiting a similar metabolic phenotype as the fasting response. Comparison between MCD and choline-deficient diet (CD) treatments suggested that the addition of MD-induced metabolic alterations, such as WAT lipolysis, to CD-induced hepatic steatosis promotes liver injury. Collectively, these results demonstrate an important role for dietary methionine deficiency and WAT lipolysis in the development of MCD-NASH. PMID:25178843

  13. Interleukin-1β inhibits insulin signaling and prevents insulin-stimulated system A amino acid transport in primary human trophoblasts.

    PubMed

    Aye, Irving L M H; Jansson, Thomas; Powell, Theresa L

    2013-12-05

    Interleukin-1β (IL-1β) promotes insulin resistance in tissues such as liver and skeletal muscle; however the influence of IL-1β on placental insulin signaling is unknown. We recently reported increased IL-1β protein expression in placentas of obese mothers, which could contribute to insulin resistance. In this study, we tested the hypothesis that IL-1β inhibits insulin signaling and prevents insulin-stimulated amino acid transport in cultured primary human trophoblast (PHT) cells. Cultured trophoblasts isolated from term placentas were treated with physiological concentrations of IL-1β (10pg/ml) for 24h. IL-1β increased the phosphorylation of insulin receptor substrate-1 (IRS-1) at Ser307 (inhibitory) and decreased total IRS-1 protein abundance but did not affect insulin receptor β expression. Furthermore, IL-1β inhibited insulin-stimulated phosphorylation of IRS-1 (Tyr612, activation site) and Akt (Thr308) and prevented insulin-stimulated increase in PI3K/p85 and Grb2 protein expression. IL-1β alone stimulated cRaf (Ser338), MEK (Ser221) and Erk1/2 (Thr202/Tyr204) phosphorylation. The inflammatory pathways nuclear factor kappa B and c-Jun N-terminal kinase, which are involved in insulin resistance, were also activated by IL-1β treatment. Moreover, IL-1β inhibited insulin-stimulated System A, but not System L amino acid uptake, indicating functional impairment of insulin signaling. In conclusion, IL-1β inhibited the insulin signaling pathway by inhibiting IRS-1 signaling and prevented insulin-stimulated System A transport, thereby promoting insulin resistance in cultured PHT cells. These findings indicate that conditions which lead to increased systemic maternal or placental IL-1β levels may attenuate the effects of maternal insulin on placental function and consequently fetal growth. Published by Elsevier Ireland Ltd.

  14. Interleukin-1β Inhibits Insulin Signaling and Prevents Insulin-Stimulated System A Amino Acid Transport in Primary Human Trophoblasts

    PubMed Central

    Aye, Irving L. M. H.; Jansson, Thomas; Powell, Theresa L.

    2013-01-01

    Interleukin-1β (IL-1β) promotes insulin resistance in tissues such as liver and skeletal muscle; however the influence of IL-1β on placental insulin signaling is unknown. We recently reported increased IL-1β protein expression in placentas of obese mothers, which could contribute to insulin resistance. In this study, we tested the hypothesis that IL-1β inhibits insulin signaling and prevents insulin-stimulated amino acid transport in cultured primary human trophoblast (PHT) cells. Cultured trophoblasts isolated from term placentas were treated with physiological concentrations of IL-1β (10 pg/ml) for 24 hours. IL-1β increased the phosphorylation of insulin receptor substrate-1 (IRS-1) at Ser307 (inhibitory) and decreased total IRS-1 protein abundance but did not affect insulin receptor β expression. Furthermore, IL-1β inhibited insulin-stimulated phosphorylation of IRS-1 (Tyr612, activation site) and Akt (Thr308) and prevented insulin-stimulated increase in PI3K/p85 and Grb2 protein expression. IL-1β alone stimulated cRaf (Ser338), MEK (Ser221) and Erk1/2 (Thr202/Tyr204) phosphorylation. The inflammatory pathways nuclear factor kappa B and c-Jun N-terminal kinase, which are involved in insulin resistance, were also activated by IL-1β treatment. Moreover, IL-1β inhibited insulin-stimulated System A, but not System L amino acid uptake, indicating functional impairment of insulin signaling. In conclusion, IL-1β inhibited the insulin signaling pathway by inhibiting IRS-1 signaling and prevented insulin-stimulated System A transport, thereby promoting insulin resistance in cultured PHT cells. These findings indicate that conditions which lead to increased systemic maternal or placental IL-1β levels may attenuate the effects of maternal insulin on placental function and consequently fetal growth. PMID:23891856

  15. Watching fat digestion: a microscopic method assessing intraluminal lipolysis.

    PubMed

    Alliet, P; Eggermont, E

    1990-01-01

    We investigated the utility of a microscopic method assessing lipolytic activity of duodenal fluid. The method is based on evaluating microscopically physicochemical changes along time when olive oil is mixed with duodenal fluid in the presence of excess bile salts (13 mM) and calcium ions (8 mM) at pH 6.5. Data are analyzed on duodenal aspirations from 155 children referred for failure to thrive or gastrointestinal disorders. The "fat digestion index" (FDI) is the percentage of intact olive oil droplets that underwent complete hydrolysis or are transformed into amorphous reticular bodies (ARB) at steady state. In all patients with proven exocrine pancreatic disorder, a FDI less than 25% was found. This value was thus considered as a cut-off value. When no microscopic lipolysis (FDI = 0) was observed, exocrine pancreatic enzyme assays are suggestive for a total exocrine pancreatic insufficiency. In the group of children with FDI ranging 5-25%, however, no statistical difference in exocrine pancreatic enzymes could be found, as compared to control values. Our tests thus evaluate fat digestion in a dynamic way. It further seems to give additional information on intraluminal lipolysis as compared to exocrine pancreatic enzyme concentrations, since it gives an idea about the integrated action of (co)lipase and bile salts.

  16. Mechanisms of Insulin Resistance After Insulin-Induced Hypoglycemia in Humans: The Role of Lipolysis

    PubMed Central

    Lucidi, Paola; Rossetti, Paolo; Porcellati, Francesca; Pampanelli, Simone; Candeloro, Paola; Andreoli, Anna Marinelli; Perriello, Gabriele; Bolli, Geremia B.; Fanelli, Carmine G.

    2010-01-01

    OBJECTIVE Changes in glucose metabolism occurring during counterregulation are, in part, mediated by increased plasma free fatty acids (FFAs), as a result of hypoglycemia-activated lipolysis. However, it is not known whether FFA plays a role in the development of posthypoglycemic insulin resistance as well. RESEARCH DESIGN AND METHODS We conducted a series of studies in eight healthy volunteers using acipimox, an inhibitor of lipolysis. Insulin action was measured during a 2-h hyperinsulinemic-euglycemic clamp (plasma glucose [PG] 5.1 mmo/l) from 5:00 p.m. to 7:00 p.m. or after a 3-h morning hyperinsulinemic-glucose clamp (from 10 a.m. to 1:00 p.m.), either euglycemic (study 1) or hypoglycemic (PG 3.2 mmol/l, studies 2–4), during which FFA levels were allowed to increase (study 2), were suppressed by acipimox (study 3), or were replaced by infusing lipids (study 4). [6,6-2H2]-Glucose was infused to measure glucose fluxes. RESULTS Plasma adrenaline, norepinephrine, growth hormone, and cortisol levels were unchanged (P > 0.2). Glucose infusion rates (GIRs) during the euglycemic clamp were reduced by morning hypoglycemia in study 2 versus study 1 (16.8 ± 2.3 vs. 34.1 ± 2.2 μmol/kg/min, respectively, P < 0.001). The effect was largely removed by blockade of lipolysis during hypoglycemia in study 3 (28.9 ± 2.6 μmol/kg/min, P > 0.2 vs. study 1) and largely reproduced by replacement of FFA in study 4 (22.3 ± 2.8 μmol/kg/min, P < 0.03 vs. study 1). Compared with study 2, blockade of lipolysis in study 3 decreased endogenous glucose production (2 ± 0.3 vs. 0.85 ± 0.1 μmol/kg/min, P < 0.05) and increased glucose utilization (16.9 ± 1.85 vs. 28.5 ± 2.7 μmol/kg/min, P < 0.05). In study 4, GIR fell by ∼23% (22.3 ± 2.8 μmol/kg/min, vs. study 3, P = 0.058), indicating a role of acipimox per se on insulin action. CONCLUSION Lipolysis induced by hypoglycemia counterregulation largely mediates posthypoglycemic insulin resistance in healthy subjects, with an

  17. Insulin and Metabolic Stress Stimulate Multisite Serine/Threonine Phosphorylation of Insulin Receptor Substrate 1 and Inhibit Tyrosine Phosphorylation*

    PubMed Central

    Hançer, Nancy J.; Qiu, Wei; Cherella, Christine; Li, Yedan; Copps, Kyle D.; White, Morris F.

    2014-01-01

    IRS1 and IRS2 are key substrates of the insulin receptor tyrosine kinase. Mass spectrometry reveals more than 50 phosphorylated IRS1 serine and threonine residues (Ser(P)/Thr(P) residues) in IRS1 from insulin-stimulated cells or human tissues. We investigated a subset of IRS1 Ser(P)/Thr(P) residues using a newly developed panel of 25 phospho-specific monoclonal antibodies (αpS/TmAbIrs1). CHO cells overexpressing the human insulin receptor and rat IRS1 were stimulated with insulin in the absence or presence of inhibitors of the PI3K → Akt → mechanistic target of rapamycin (mTOR) → S6 kinase or MEK pathways. Nearly all IRS1 Ser(P)/Thr(P) residues were stimulated by insulin and significantly suppressed by PI3K inhibition; fewer were suppressed by Akt or mTOR inhibition, and none were suppressed by MEK inhibition. Insulin-stimulated Irs1 tyrosine phosphorylation (Tyr(P)Irs1) was enhanced by inhibition of the PI3K → Akt → mTOR pathway and correlated with decreased Ser(P)-302Irs1, Ser(P)-307Irs1, Ser(P)-318Irs1, Ser(P)-325Irs1, and Ser(P)-346Irs1. Metabolic stress modeled by anisomycin, thapsigargin, or tunicamycin increased many of the same Ser(P)/Thr(P) residues as insulin, some of which (Ser(P)-302Irs1, Ser(P)-307Irs1, and four others) correlated significantly with impaired insulin-stimulated Tyr(P)Irs1. Thus, IRS1 Ser(P)/Thr(P) is an integrated response to insulin stimulation and metabolic stress, which associates with reduced Tyr(P)Irs1 in CHOIR/IRS1 cells. PMID:24652289

  18. Evaluation of safety and efficacy of 980-nm diode laser-assisted lipolysis versus traditional liposuction for submental rejuvenation: A randomized clinical trial.

    PubMed

    Valizadeh, Neda; Jalaly, Niloofar Y; Zarghampour, Manijeh; Barikbin, Behrooz; Haghighatkhah, Hamid Reza

    2016-01-01

    Submental fat accumulation and skin laxity is a frequent concern of cosmetic patients. The aim of this randomized prospective controlled clinical trial was to compare the efficacy and safety of laser-assisted lipolysis and liposuction in the submental rejuvenation. Thirty-six female adults were enrolled in this clinical trial and were categorized into two groups: group 1 underwent 980-nm diode laser with the power of 6-8 W and group 2 underwent traditional liposuction. Patients were evaluated with ultrasonography 2 weeks and 2 months after the procedures. Ultrasonographic evaluation reported the significant reduction of fat thickness in each group compared with the baseline (p value < 0.001). At the 2 weeks and 2 months follow-up visit, fat thickness reduction was significantly higher in the lipolysis group (p value < 0.05). Overall patients' satisfaction in lipolysis group was higher than liposuction with 11 (61%) of lipolysis patients being very satisfied in contrast to 10 (55.5%) of liposuction patients reporting "dissatisfied or neutral" results. Laser-assisted lipolysis using 980-nm diode is approved to be safe and effective for skin tightening and rejuvenation of the submental area and seems to be a better option than traditional techniques for treatment of this cosmetic problem.

  19. Streptococcus mutans competence-stimulating peptide inhibits Candida albicans hypha formation.

    PubMed

    Jarosz, Lucja M; Deng, Dong Mei; van der Mei, Henny C; Crielaard, Wim; Krom, Bastiaan P

    2009-11-01

    The oral cavity is colonized by microorganisms growing in biofilms in which interspecies interactions take place. Streptococcus mutans grows in biofilms on enamel surfaces and is considered one of the main etiological agents of human dental caries. Candida albicans is also commonly found in the human oral cavity, where it interacts with S. mutans. C. albicans is a polymorphic fungus, and the yeast-to-hypha transition is involved in virulence and biofilm formation. The aim of this study was to investigate interkingdom communication between C. albicans and S. mutans based on the production of secreted molecules. S. mutans UA159 inhibited C. albicans germ tube (GT) formation in cocultures even when physically separated from C. albicans. Only S. mutans spent medium collected in the early exponential phase (4-h-old cultures) inhibited the GT formation of C. albicans. During this phase, S. mutans UA159 produces a quorum-sensing molecule, competence-stimulating peptide (CSP). The role of CSP in inhibiting GT formation was confirmed by using synthetic CSP and a comC deletion strain of S. mutans UA159, which lacks the ability to produce CSP. Other S. mutans strains and other Streptococcus spp. also inhibited GT formation but to different extents, possibly reflecting differences in CSP amino acid sequences among Streptococcus spp. or differences in CSP accumulation in the media. In conclusion, CSP, an S. mutans quorum-sensing molecule secreted during the early stages of growth, inhibits the C. albicans morphological switch.

  20. Fatty acids from VLDL lipolysis products induce lipid droplet accumulation in human monocytes

    PubMed Central

    den Hartigh, Laura J; Connolly-Rohrbach, Jaime E; Fore, Samantha; Huser, Thomas R; Rutledge, John C

    2010-01-01

    One mechanism by which monocytes become activated postprandially is by exposure to triglyceride (TG)-rich lipoproteins such as very low-density lipoproteins (VLDL). VLDL are hydrolyzed by lipoprotein lipase (LpL) at the blood-endothelial cell interface, releasing free fatty acids. In this study, we examined postprandial monocyte activation in more detail, and found that lipolysis products generated from postprandial VLDL induce the formation of lipid-filled droplets within cultured THP-1 monocytes, characterized by coherent anti-stokes Raman spectroscopy. Organelle-specific stains revealed an association of lipid droplets with the endoplasmic reticulum, confirmed by electron microscopy. Lipid droplet formation was reduced when LpL-released fatty acids were bound by bovine serum albumin, which also reduced cellular inflammation. Furthermore, saturated fatty acids induced more lipid droplet formation in monocytes compared to mono- and polyunsaturated fatty acids. Monocytes treated with postprandial VLDL lipolysis products contained lipid droplets with more intense saturated Raman spectroscopic signals than monocytes treated with fasting VLDL lipolysis products. In addition, we found that human monocytes isolated during the peak postprandial period contain more lipid droplets compared to those from the fasting state, signifying that their development is not limited to cultured cells but also occurs in vivo. In summary, circulating free fatty acids can mediate lipid droplet formation in monocytes and potentially be used as a biomarker to assess an individual’s risk of developing atherosclerotic cardiovascular disease. PMID:20208007

  1. Impact of cell wall encapsulation of almonds on in vitro duodenal lipolysis.

    PubMed

    Grundy, Myriam M L; Wilde, Peter J; Butterworth, Peter J; Gray, Robert; Ellis, Peter R

    2015-10-15

    Although almonds have a high lipid content, their consumption is associated with reduced risk of cardiovascular disease. One explanation for this paradox could be limited bioaccessibility of almond lipids due to the cell wall matrix acting as a physical barrier to digestion in the upper gastrointestinal tract. We aimed to measure the rate and extent of lipolysis in an in vitro duodenum digestion model, using raw and roasted almond materials with potentially different degrees of bioaccessibility. The results revealed that a decrease in particle size led to an increased rate and extent of lipolysis. Particle size had a crucial impact on lipid bioaccessibility, since it is an indicator of the proportion of ruptured cells in the almond tissue. Separated almond cells with intact cell walls showed the lowest levels of digestibility. This study underlines the importance of the cell wall for modulating lipid uptake and hence the positive health benefits underlying almond consumption. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. In vitro digestion of the self-emulsifying lipid excipient Labrasol(®) by gastrointestinal lipases and influence of its colloidal structure on lipolysis rate.

    PubMed

    Fernandez, Sylvie; Jannin, Vincent; Chevrier, Stéphanie; Chavant, Yann; Demarne, Frédéric; Carrière, Frédéric

    2013-12-01

    Labrasol(®) is a self-emulsifying excipient used to improve the oral bioavailability of poorly water-soluble drugs. It is a mixture of acylglycerols and PEG esters, these compounds being substrates for digestive lipases. The characterization of Labrasol(®) gastrointestinal lipolysis is essential for understanding its mode of action. Labrasol(®) lipolysis was investigated using either individual enzymes (gastric lipase, pancreatic lipase-related protein 2, pancreatic carboxyl ester hydrolase) or a combination of enzymes under in vitro conditions mimicking first the gastric phase of lipolysis and second the duodenal one. Specific methods for quantifying lipolysis products were established in order to determine which compounds in Labrasol(®) were preferentially hydrolyzed. Gastric lipase showed a preference for di- and triacylglycerols and the main acylglycerols remaining after gastric lipolysis were monoacylglycerols. PEG-8 diesters were also hydrolyzed to a large extent by gastric lipase. Most of the compounds initially present in Labrasol(®) were found to be totally hydrolyzed after the duodenal phase of lipolysis. The rate of Labrasol(®) hydrolysis by individual lipases was found to vary significantly with the dilution of the excipient in water and the resulting colloidal structures (translucent dispersion; opaque emulsion; transparent microemulsion), each lipase displaying a distinct pattern depending on the particle size. The lipases with distinct substrate specificities used in this study were found to be sensitive probes of phase transitions occurring upon Labrasol(®) dilution. In addition to their use for developing in vitro digestion models, these enzymes are interesting tools for the characterization of self-emulsifying lipid-based formulations.

  3. Effects of surfactants on lipase structure, activity, and inhibition.

    PubMed

    Delorme, Vincent; Dhouib, Rabeb; Canaan, Stéphane; Fotiadu, Frédéric; Carrière, Frédéric; Cavalier, Jean-François

    2011-08-01

    Lipase inhibitors are the main anti-obesity drugs prescribed these days, but the complexity of their mechanism of action is making it difficult to develop new molecules for this purpose. The efficacy of these drugs is known to depend closely on the physico-chemistry of the lipid-water interfaces involved and on the unconventional behavior of the lipases which are their target enzymes. The lipolysis reaction which occurs at an oil-water interface involves complex equilibria between adsorption-desorption processes, conformational changes and catalytic mechanisms. In this context, surfactants can induce significant changes in the partitioning of the enzyme and the inhibitor between the water phase and lipid-water interfaces. Surfactants can be found at the oil-water interface where they compete with lipases for adsorption, but also in solution in the form of micellar aggregates and monomers that may interact with hydrophobic parts of lipases in solution. These various interactions, combined with the emulsification and dispersion of insoluble substrates and inhibitors, can either promote or decrease the activity and the inhibition of lipases. Here, we review some examples of the various effects of surfactants on lipase structure, activity and inhibition, which show how complex the various equilibria involved in the lipolysis reaction tend to be.

  4. miR-378 Activates the Pyruvate-PEP Futile Cycle and Enhances Lipolysis to Ameliorate Obesity in Mice

    PubMed Central

    Zhang, Yong; Li, Changyin; Li, Hu; Song, Yipeng; Zhao, Yixia; Zhai, Lili; Wang, Haixia; Zhong, Ran; Tang, Huiru; Zhu, Dahai

    2016-01-01

    Obesity has been linked to many health problems, such as diabetes. However, there is no drug that effectively treats obesity. Here, we reveal that miR-378 transgenic mice display reduced fat mass, enhanced lipolysis, and increased energy expenditure. Notably, administering AgomiR-378 prevents and ameliorates obesity in mice. We also found that the energy deficiency seen in miR-378 transgenic mice was due to impaired glucose metabolism. This impairment was caused by an activated pyruvate-PEP futile cycle via the miR-378-Akt1-FoxO1-PEPCK pathway in skeletal muscle and enhanced lipolysis in adipose tissues mediated by miR-378-SCD1. Our findings demonstrate that activating the pyruvate-PEP futile cycle in skeletal muscle is the primary cause of elevated lipolysis in adipose tissues of miR-378 transgenic mice, and it helps orchestrate the crosstalk between muscle and fat to control energy homeostasis in mice. Thus, miR-378 may serve as a promising agent for preventing and treating obesity in humans. PMID:27077116

  5. Inhibition by alpha- and beta-adrenoceptors of the twitch response to transmural stimulation in the guinea-pig vas deferens.

    PubMed

    Hedqvist, P; Von Euler, U S

    1976-11-01

    Noradrenaline as well as the indirectly acting amines tyramine and phenethylamine either enhance or inhibit the twitch response of the transmurally stimulated, isolated guine-pig vas deferens, thus partly confirming previous reports. In both cases enhancement is annulled by alpha-adrenoceptor blockers. The twitch inhibition caused by noradrenaline is abolished by alpha- + beta2-adrenoceptor blockers, but not by either blocker alone. The inhibition caused by the indirectly acting amines is largely abolished by alpha-adrenoceptor blockers. Clonidine strongly inhibits the twitch. This effect if promptly removed by phentolamine. After blockade of the neurally induced twitch by tetrodotoxin, noradrenaline and the indirectly acting amines have no effect or slightly enhance the twitch elicited by transmural stimulation of the smooth muscle. It is concluded that exogenous noradrenaline acts on postjunctional stimulatory alpha-adrenoceptors and on inhibitory alpha- and beta2-adrenoceptors, which are presumably prejunctional. In the unstimulated preparation contracted by acetylcholine, noradrenaline causes further contraction which is changed into relaxation after phentolamine. This relaxation is abolished by butoxamine, suggesting that noradrenaline may also act on inhibitory postjunctional beta2-adrenoceptors. The twitch-inhibiting effect of endogenous noradrenaline, released by nerve stimulation or by indirectly acting amines, appears to be primarily mediated by prejunctional alpha-adrenoceptors.

  6. Ceruloplasmin inhibits carbonyl formation in endogenous proteins in phorbol myristate acetate (PMA)-stimulated neutrophils

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Krsek-Staples, J.; Webster, R.O.

    1991-03-11

    The respiratory burst of stimulated neutrophils can cause oxidative modifications of endogenous neutrophil proteins as measured by increased carbonyl formation. Ceruloplasmin is an acute phase protein and may act as an antioxidant during inflammation. Therefore, the role of ceruloplasmin in preventing oxidative damage of endogenous neutrophil proteins was investigated. Protein carbonyl content was determined spectrophotometrically using 2,4-dinitrophenylhydrazine. Ceruloplasmin, at a concentration present during inflammation significantly inhibited carbonyl formation in endogenous proteins of PMA-stimulated neutrophils. In order to determine if oxidative damage was occurring to the ceruloplasmin upon incubation with stimulated neutrophils, carbonyl formation in the ceruloplasmin in the presence andmore » absence of stimulated neutrophils. This data suggests that ceruloplasmin may play a role in regulating oxidative damage to proteins and that ceruloplasmin itself may act as a target for these modifications.« less

  7. Identification of Interferon-Stimulated Gene Proteins That Inhibit Human Parainfluenza Virus Type 3

    PubMed Central

    Rabbani, M. A. G.; Ribaudo, Michael; Guo, Ju-Tao

    2016-01-01

    ABSTRACT A major arm of cellular innate immunity is type I interferon (IFN), represented by IFN-α and IFN-β. Type I IFN transcriptionally induces a large number of cellular genes, collectively known as IFN-stimulated gene (ISG) proteins, which act as antivirals. The IFIT (interferon-induced proteins with tetratricopeptide repeats) family proteins constitute a major subclass of ISG proteins and are characterized by multiple tetratricopeptide repeats (TPRs). In this study, we have interrogated IFIT proteins for the ability to inhibit the growth of human parainfluenza virus type 3 (PIV3), a nonsegmented negative-strand RNA virus of the Paramyxoviridae family and a major cause of respiratory disease in children. We found that IFIT1 significantly inhibited PIV3, whereas IFIT2, IFIT3, and IFIT5 were less effective or not at all. In further screening a set of ISG proteins we discovered that several other such proteins also inhibited PIV3, including IFITM1, IDO (indoleamine 2,3-dioxygenase), PKR (protein kinase, RNA activated), and viperin (virus inhibitory protein, endoplasmic reticulum associated, interferon inducible)/Cig5. The antiviral effect of IDO, the enzyme that catalyzes the first step of tryptophan degradation, could be counteracted by tryptophan. These results advance our knowledge of diverse ISG proteins functioning as antivirals and may provide novel approaches against PIV3. IMPORTANCE The innate immunity of the host, typified by interferon (IFN), is a major antiviral defense. IFN inhibits virus growth by inducing a large number of IFN-stimulated gene (ISG) proteins, several of which have been shown to have specific antiviral functions. Parainfluenza virus type 3 (PIV3) is major pathogen of children, and no reliable vaccine or specific antiviral against it currently exists. In this article, we report several ISG proteins that strongly inhibit PIV3 growth, the use of which may allow a better antiviral regimen targeting PIV3. PMID:27707917

  8. Intraportal infusion of ghrelin could inhibit glucose-stimulated GLP-1 secretion by enteric neural net in Wistar rat.

    PubMed

    Zhang, Xiyao; Li, Wensong; Li, Ping; Chang, Manli; Huang, Xu; Li, Qiang; Cui, Can

    2014-01-01

    As a regulator of food intake and energy metabolism, the role of ghrelin in glucose metabolism is still not fully understood. In this study, we determined the in vivo effect of ghrelin on incretin effect. We demonstrated that ghrelin inhibited the glucose-stimulated release of glucagon-like peptide-1 (GLP-1) when infused into the portal vein of Wistar rat. Hepatic vagotomy diminished the inhibitory effect of ghrelin on glucose-stimulated GLP-1 secretion. In addition, phentolamine, a nonselective α receptor antagonist, could recover the decrease of GLP-1 release induced by ghrelin infusion. Pralmorelin (an artificial growth hormone release peptide) infusion into the portal vein could also inhibit the glucose-stimulated release of GLP-1. And growth hormone secretagogue receptor antagonist, [D-lys3]-GHRP-6, infusion showed comparable increases of glucose stimulated GLP-1 release compared to ghrelin infusion into the portal vein. The data showed that intraportal infusion of ghrelin exerted an inhibitory effect on GLP-1 secretion through growth hormone secretagogue receptor 1α (GHS1α receptor), which indicated that the downregulation of ghrelin secretion after food intake was necessary for incretin effect. Furthermore, our results suggested that the enteric neural net involved hepatic vagal nerve and sympathetic nerve mediated inhibition effect of ghrelin on incretin effect.

  9. Galvanic Tongue Stimulation Inhibits Five Basic Tastes Induced by Aqueous Electrolyte Solutions.

    PubMed

    Aoyama, Kazuma; Sakurai, Kenta; Sakurai, Satoru; Mizukami, Makoto; Maeda, Taro; Ando, Hideyuki

    2017-01-01

    Galvanic tongue stimulation (GTS) modulates taste sensation. However, the effect of GTS is contingent on the electrode polarity in the proximity of the tongue. If an anodal electrode is attached in the proximity of the tongue, an electrical or metallic taste is elicited. On the other hand, if only cathodal electrode is attached in the proximity of the tongue, the salty taste, which is induced by electrolyte materials, is inhibited. The mechanism of this taste inhibition is not adequately understood. In this study, we aim to demonstrate that the inhibition is cause by ions, which elicit taste and which migrate from the taste sensors on the tongue by GTS. We verified the inhibitory effect of GTS on all five basic tastes induced by electrolyte materials. This technology is effective for virtual reality systems and interfaces to support dietary restrictions. Our findings demonstrate that cathodal-GTS inhibits all the five basic tastes. The results also support our hypothesis that the effects of cathodal-GTS are caused by migrating tasting ions in the mouth.

  10. An in vitro approach for lipolysis measurement using high-resolution mass spectrometry and partial least squares based analysis.

    PubMed

    Chang, Wen-Qi; Zhou, Jian-Liang; Li, Yi; Shi, Zi-Qi; Wang, Li; Yang, Jie; Li, Ping; Liu, Li-Fang; Xin, Gui-Zhong

    2017-01-15

    The elevation of free fatty acids (FFAs) has been regarded as a universal metabolic signature of excessive adipocyte lipolysis. Nowadays, in vitro lipolysis assay is generally essential for drug screening prior to the animal study. Here, we present a novel in vitro approach for lipolysis measurement combining UHPLC-Orbitrap and partial least squares (PLS) based analysis. Firstly, the calibration matrix was constructed by serial proportions of mixed samples (blended with control and model samples). Then, lipidome profiling was performed by UHPLC-Orbitrap, and 403 variables were extracted and aligned as dataset. Owing to the high resolution of Orbitrap analyzer and open source lipid identification software, 28 FFAs were further screened and identified. Based on the relative intensity of the screened FFAs, PLS regression model was constructed for lipolysis measurement. After leave-one-out cross-validation, ten principal components have been designated to build the final PLS model with excellent performances (RMSECV, 0.0268; RMSEC, 0.0173; R 2 , 0.9977). In addition, the high predictive accuracy (R 2  = 0.9907 and RMSEP = 0.0345) of the trained PLS model was also demonstrated using test samples. Finally, taking curcumin as a model compound, its antilipolytic effect on palmitic acid-induced lipolysis was successfully predicted as 31.78% by the proposed approach. Besides, supplementary evidences of curcumin induced modification in FFAs compositions as well as lipidome were given by PLS extended methods. Different from general biological assays, high resolution MS-based method provide more sophisticated information included in biological events. Thus, the novel biological evaluation model proposed here showed promising perspectives for drug evaluation or disease diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. The role of plant cell wall encapsulation and porosity in regulating lipolysis during the digestion of almond seeds.

    PubMed

    Grundy, Myriam M L; Carrière, Frédéric; Mackie, Alan R; Gray, David A; Butterworth, Peter J; Ellis, Peter R

    2016-01-01

    Previous studies have provided evidence that the physical encapsulation of intracellular nutrients by cell walls of plant foods (i.e. dietary fibre) plays a predominant role in influencing macronutrient bioaccessibility (release) from plant foods during human digestion. One unexplored aspect of this is the extent to which digestive enzymes can pass through the cell-wall barrier and hydrolyse the intracellular lipid in almond seeds. The purpose of the present study was to assess the role played by cell walls in influencing the bioaccessibility and digestibility of almond lipid using a range of techniques. Digestibility experiments were performed on raw and roasted almond cells as well as isolated almond oil bodies using in vitro gastric and duodenal digestion models. Residual triacylglycerols and lipolysis products were extracted after 1 h of incubation and analysed by thin layer chromatography. The lipolysis kinetics of almond cells and oil bodies were also investigated using the pH-stat technique. Finally, the potential penetration of pancreatic lipase through the cell wall matrix was investigated using confocal microscopy. Differences in the rates and extent of lipolysis were clearly seen between almond cells and oil bodies, and these differences were observed regardless of the lipase(s) used. These results also showed that almond cell walls that are completely intact limit lipid digestibility, due to an encapsulation mechanism that hinders the diffusion of lipase into the intracellular environment and lipolysis products out of the cells.

  12. A Selective TSH Receptor Antagonist Inhibits Stimulation of Thyroid Function in Female Mice

    PubMed Central

    Neumann, Susanne; Nir, Eshel A.; Eliseeva, Elena; Huang, Wenwei; Marugan, Juan; Xiao, Jingbo; Dulcey, Andrés E.

    2014-01-01

    Because the TSH receptor (TSHR) plays an important role in the pathogenesis of thyroid disease, a TSHR antagonist could be a novel treatment. We attempted to develop a small molecule, drug-like antagonist of TSHR signaling that is selective and active in vivo. We synthesized NCGC00242364 (ANTAG3) by chemical modification of a previously reported TSHR antagonist. We tested its potency, efficacy, and selectivity in a model cell system in vitro by measuring its activity to inhibit stimulation of cAMP production stimulated by TSH, LH, or FSH. We tested the in vivo activity of ANTAG3 by measuring its effects to lower serum free T4 and thyroid gene expression in female BALB/c mice continuously treated with ANTAG3 for 3 days and given low doses of TRH continuously or stimulated by a single administration of a monoclonal thyroid-stimulating antibody M22. ANTAG3 was selective for TSHR inhibition; half-maximal inhibitory doses were 2.1 μM for TSHR and greater than 30 μM for LH and FSH receptors. In mice treated with TRH, ANTAG3 lowered serum free T4 by 44% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 75% and 83%, respectively. In mice given M22, ANTAG3 lowered serum free T4 by 38% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 73% and 40%, respectively. In conclusion, we developed a selective TSHR antagonist that is effective in vivo in mice. This is the first report of a small-molecule TSHR antagonist active in vivo and may lead to a drug to treat Graves' disease. PMID:24169564

  13. A selective TSH receptor antagonist inhibits stimulation of thyroid function in female mice.

    PubMed

    Neumann, Susanne; Nir, Eshel A; Eliseeva, Elena; Huang, Wenwei; Marugan, Juan; Xiao, Jingbo; Dulcey, Andrés E; Gershengorn, Marvin C

    2014-01-01

    Because the TSH receptor (TSHR) plays an important role in the pathogenesis of thyroid disease, a TSHR antagonist could be a novel treatment. We attempted to develop a small molecule, drug-like antagonist of TSHR signaling that is selective and active in vivo. We synthesized NCGC00242364 (ANTAG3) by chemical modification of a previously reported TSHR antagonist. We tested its potency, efficacy, and selectivity in a model cell system in vitro by measuring its activity to inhibit stimulation of cAMP production stimulated by TSH, LH, or FSH. We tested the in vivo activity of ANTAG3 by measuring its effects to lower serum free T4 and thyroid gene expression in female BALB/c mice continuously treated with ANTAG3 for 3 days and given low doses of TRH continuously or stimulated by a single administration of a monoclonal thyroid-stimulating antibody M22. ANTAG3 was selective for TSHR inhibition; half-maximal inhibitory doses were 2.1 μM for TSHR and greater than 30 μM for LH and FSH receptors. In mice treated with TRH, ANTAG3 lowered serum free T4 by 44% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 75% and 83%, respectively. In mice given M22, ANTAG3 lowered serum free T4 by 38% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 73% and 40%, respectively. In conclusion, we developed a selective TSHR antagonist that is effective in vivo in mice. This is the first report of a small-molecule TSHR antagonist active in vivo and may lead to a drug to treat Graves' disease.

  14. The inhibition of amine oxidase and the central stimulating action of the stereoisomeric amphetamines and 1-phenylethylamines

    PubMed Central

    Grana, E.; Lilla, L.

    1959-01-01

    The stereoisomers of amphetamine and 1-phenylethylamine have been studied in the rat both as central stimulants and as inhibitors of amine oxidase from brain, liver, and kidney. There was no correlation between these two effects; thus it is unlikely that the central stimulating action of amphetamine is due to inhibition of amine oxidase. PMID:13828860

  15. Stimulation of the cardiac myocyte Na+-K+ pump due to reversal of its constitutive oxidative inhibition

    PubMed Central

    Chia, Karin K. M.; Liu, Chia-Chi; Hamilton, Elisha J.; Garcia, Alvaro; Fry, Natasha A.; Hannam, William; Figtree, Gemma A.

    2015-01-01

    Protein kinase C can activate NADPH oxidase and induce glutathionylation of the β1-Na+-K+ pump subunit, inhibiting activity of the catalytic α-subunit. To examine if signaling of nitric oxide-induced soluble guanylyl cyclase (sGC)/cGMP/protein kinase G can cause Na+-K+ pump stimulation by counteracting PKC/NADPH oxidase-dependent inhibition, cardiac myocytes were exposed to ANG II to activate NADPH oxidase and inhibit Na+-K+ pump current (Ip). Coexposure to 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1) to stimulate sGC prevented the decrease of Ip. Prevention of the decrease was abolished by inhibition of protein phosphatases (PP) 2A but not by inhibition of PP1, and it was reproduced by an activator of PP2A. Consistent with a reciprocal relationship between β1-Na+-K+ pump subunit glutathionylation and pump activity, YC-1 decreased ANG II-induced β1-subunit glutathionylation. The decrease induced by YC-1 was abolished by a PP2A inhibitor. YC-1 decreased phosphorylation of the cytosolic p47phox NADPH oxidase subunit and its coimmunoprecipitation with the membranous p22phox subunit, and it decreased O2·−-sensitive dihydroethidium fluorescence of myocytes. Addition of recombinant PP2A to myocyte lysate decreased phosphorylation of p47phox indicating the subunit could be a substrate for PP2A. The effects of YC-1 to decrease coimmunoprecipitation of p22phox and p47phox NADPH oxidase subunits and decrease β1-Na+-K+ pump subunit glutathionylation were reproduced by activation of nitric oxide-dependent receptor signaling. We conclude that sGC activation in cardiac myocytes causes a PP2A-dependent decrease in NADPH oxidase activity and a decrease in β1 pump subunit glutathionylation. This could account for pump stimulation with neurohormonal oxidative stress expected in vivo. PMID:26084308

  16. Rupatadine inhibits inflammatory mediator release from human laboratory of allergic diseases 2 cultured mast cells stimulated by platelet-activating factor.

    PubMed

    Alevizos, Michail; Karagkouni, Anna; Vasiadi, Magdalini; Sismanopoulos, Nikolaos; Makris, Michael; Kalogeromitros, Dimitrios; Theoharides, Theoharis C

    2013-12-01

    Mast cells are involved in allergy and inflammation by the secretion of multiple mediators, including histamine, cytokines, and platelet-activating factor (PAF), in response to different triggers, including emotional stress. PAF has been associated with allergic inflammation, but there are no clinically available PAF inhibitors. To investigate whether PAF could stimulate human mast cell mediator release and whether rupatadine (RUP), a dual histamine-1 and PAF receptor antagonist, could inhibit the effect of PAF on human mast cells. Laboratory of allergic diseases 2 cultured mast cells were stimulated with PAF (0.001, 0.01, and 0.1 μmol/L) and substance P (1 μmol/L) with or without pretreatment with RUP (2.5 and 25 μmol/L), which was added 10 minutes before stimulation. Release of β-hexosaminidase was measured in supernatant fluid by spectrophotoscopy, and histamine, interleukin-8, and tumor necrosis factor were measured by enzyme-linked immunosorbent assay. PAF stimulated a statistically significant release of histamine, interleukin-8, and tumor necrosis factor (0.001-0.1 μmol/L) that was comparable to that stimulated by substance P. Pretreatment with RUP (25 μmol/L) for 10 minutes inhibited this effect. In contrast, pretreatment of laboratory of allergic diseases 2 cells with diphenhydramine (25 μmol/L) did not inhibit mediator release, suggesting that the effect of RUP was not due to its antihistaminic effect. PAF stimulates human mast cell release of proinflammatory mediators that is inhibited by RUP. This action endows RUP with additional properties in treating allergic inflammation. Copyright © 2013 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  17. Inhibiting effects of fructanase on competence-stimulating peptide-dependent quorum sensing system in Streptococcus mutans.

    PubMed

    Suzuki, Yusuke; Nagasawa, Ryo; Senpuku, Hidenobu

    2017-09-01

    Streptococcus mutans produces glucosyltransferases encoded by the gtfB and gtfC genes, which synthesize insoluble glucan, and both insoluble and soluble glucans by conversion of sucrose, and are known as principal agents to provide strong biofilm formation and demineralization on tooth surfaces. S. mutans possess a Com-dependent quorum sensing (QS) system, which is important for survival in severe conditions. The QS system is stimulated by the interaction between ComD {Receptor to competence-stimulating peptide (CSP)} encoded by the comD and CSP encoded by the comC, and importantly associated with bacteriocin production and genetic competence. Previously, we found enzyme fructanase (FruA) as a new inhibitor for the glucan-dependent biofilm formation. In the present study, inhibiting effects by FruA on glucan-independent biofilm formation of S. mutans UA159, UA159.gtfB - , UA159.gtfC - , and UA159.gtfBC - were observed in sucrose and no sucrose sugars-supplemented conditions using the plate assay. The reduction of UA159.comC - and UA159.comD - biofilm formation were also observed as compared with UA159 in same conditions. These results suggested that inhibitions of glucan-independent and Com-dependent biofilm formation were involved in the inhibiting mechanism by FruA. To more thoroughly investigate effects by FruA on the QS system, we examined on CSP-stimulated and Com-dependent bacteriocin production and genetic transformation. FruA inhibited bacteriocin production in collaboration with CSP and genetic transformation in bacterial cell conditions treated with FruA. Our findings show that FruA has multiple effects that inhibit survival functions of S. mutans, including biofilm formation and CSP-dependent QS responses, indicating its potential use as an agent for prevention of dental caries. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. NS-398, a selective COX-2 inhibitor, inhibits proliferation of IL-1{beta}-stimulated vascular smooth muscle cells by induction of {eta}{omicron}-1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Choi, Hyoung Chul; Kim, Hee Sun; Lee, Kwang Youn

    2008-11-28

    We investigated whether NS-398, a selective inhibitor of COX-2, induces HO-1 in IL-1{beta}-stimulated vascular smooth muscle cells (VSMC). NS-398 reduced the production of PGE{sub 2} without modulation of expression of COX-2 in IL-1{beta}-stimulated VSMC. NS-398 increased HO-1 mRNA and protein in a dose-dependent manner, but inhibited proliferation of IL-1{beta}-stimulated VSMC. Furthermore, SnPPIX, a HO-1 inhibitor, reversed the effects of NS-398 on PGE{sub 2} production, suggesting that COX-2 activity can be affected by HO-1. Hemin, a HO-1 inducer, also reduced the production of PGE{sub 2} and proliferation of IL-1{beta}-stimulated VSMC. CORM-2, a CO-releasing molecule, but not bilirubin inhibited proliferation of IL-1{beta}-stimulatedmore » VSMC. NS-398 inhibited proliferation of IL-1{beta}-stimulated VSMC in a HbO{sub 2}-sensitive manner. In conclusion, NS-398 inhibits proliferation of IL-1{beta}-stimulated VSMC by HO-1-derived CO. Thus, NS-398 may facilitate the healing process of vessels in vascular inflammatory disorders such as atherosclerosis.« less

  19. Fat tissue after lipolysis of lipomas: a histopathological and immunohistochemical study.

    PubMed

    Bechara, Falk G; Sand, Michael; Hoffmann, Klaus; Sand, Daniel; Altmeyer, Peter; Stücker, Markus

    2007-07-01

    Injections with Lipostabil, a phosphatidylcholine (PDC) containing substance, have become a popular technique to treat localized fat accumulation and lipomas for aesthetic reasons. Despite its frequent use, the mechanism of action of PDC and histological changes of treated fat tissue still remain unclear. To investigate the histological changes of lipomas after treatment with PDC. In all, fourteen lipomas (n = 14) in five patients presenting with multiple lipomas were treated with intralesional injections of PDC (Lipostabil, Nettermann, Germany). Histological changes with immunohistochemical analysis of the inflammatory process were evaluated 4, 10, 24, 48 h, 10 days, 30 days and 60 days after lipolysis. Between 4 and 48 h after injection, histology shows a lobular neutrophilic infiltrate with partially destroyed fat cells. At day 10 the inflammatory process is accompanied by an infiltration of T-lymphocytes. After 60 days formation of macrophages with foam cells are visible, accompanied by thickened septa and capsula. Lipolysis with PDC results in a distinct inflammatory reaction of affected fat tissue, similar to factitial panniculitis. Early destruction of fat cells may suggest the involvement of detergent or osmotic mechanisms in the process.

  20. Inhibition of interleukin-17-stimulated interleukin-6 and -8 production by cranberry components in human gingival fibroblasts and epithelial cells.

    PubMed

    Tipton, D A; Cho, S; Zacharia, N; Dabbous, M K

    2013-10-01

    Gingival epithelial cells and fibroblasts participate in periodontal inflammation and destruction, producing interleukin (IL)-6, a regulator of osteoclastic bone resorption, and the neutrophil chemoattractant IL-8. IL-17, a product of T-helper 17 cells, may play a role in periodontitis by stimulating cytokine production by gingival cells. The cranberry (Vaccinium macrocarpon) is rich in polyphenols, particularly proanthocyanidins, which have antioxidant and other beneficial properties. Cranberry components inhibit pro-inflammatory activities of lipopolysaccharide-stimulated human macrophages, gingival fibroblasts, and epithelial cells, but little is known of its effects on IL-17-stimulated cytokine production. The objectives were to determine the effects of IL-17 ± cranberry components on IL-6 and IL-8 production by human gingival epithelial cells and fibroblasts. Cranberry high molecular weight non-dialyzable material (NDM), which is rich in proanthocyanidins, was derived from cranberry juice. Human gingival epithelial cells and normal human gingival fibroblasts were incubated with NDM (5-50 μg/mL), IL-17 (0.5-100 ng/mL), or NDM + IL-17 in serum-free medium for 6 d. IL-6 and IL-8 in culture supernatants were measured by ELISA. Membrane damage and viability were assessed by lactate dehydrogenase activity released into cell supernatants and activity of a mitochondrial enzyme, respectively. Data were analyzed using ANOVA and Scheffe's F procedure for post hoc comparisons. In both cell lines, IL-17 (≥ ~5-10 ng/mL) significantly stimulated production of IL-6 (p < 0.005) and IL-8 (p < 0.03). Non-toxic levels of NDM inhibited constitutive IL-6 and IL-8 production by epithelial cells (p ≤ 0.01) and fibroblasts (p ≤ 0.03) as well as IL-17-stimulated cytokine production by epithelial cells [IL-6 (maximum ~80% inhibition; p ≤ 0.0001); IL-8 (maximum ~70% inhibition; p ≤ 0.03)] and fibroblasts [IL-6 (maximum ~90% inhibition; p ≤ 0.0001); IL

  1. Bioactive Extract from Moringa oleifera Inhibits the Pro-inflammatory Mediators in Lipopolysaccharide Stimulated Macrophages

    PubMed Central

    Fard, Masoumeh Tangestani; Arulselvan, Palanisamy; Karthivashan, Govindarajan; Adam, Siti Khadijah; Fakurazi, Sharida

    2015-01-01

    Introduction: Inflammation is a well-known physiological response to protect the body against infection and restore tissue injury. Nevertheless, the chronic inflammation can trigger various inflammatory associated diseases/disorder. Moringa oleifera is a widely grown plant in most tropical countries and it has been recognized traditionally for several medicinal benefits. Objectives: The objective of this study was to investigate the anti-inflammatory properties of M. oleifera extract on lipopolysaccharide (LPS) - stimulated macrophages. Materials and Methods: The anti-inflammatory effect of M. oleifera hydroethanolic bioactive leaves extracts was evaluated by assessing the inhibition of nitric oxide (NO) production during Griess reaction and the expression of pro-inflammatory mediators in macrophages. Results: Interestingly, we found that M. oleifera hydroethanolic bioactive leaves extract significantly inhibited the secretion of NO production and other inflammatory markers such as prostaglandin E2, tumor necrosis factor alpha, interleukin (IL)-6, and IL-1β. Meanwhile, the bioactive extract has induced the production of IL-10 in a dose-dependent manner. In addition, M. oleifera hydroethanolic bioactive leaves extract effectively suppressed the protein expression of inflammatory markers inducible NO synthase, cyclooxygenase-2, and nuclear factor kappa-light-chain-enhancer of activated B-cells p65 in LPS-induced RAW264.7 macrophages in a dose-dependent manner. Conclusion: These findings support the traditional use of M. oleifera plant as an effective treatment for inflammation associated diseases/disorders. SUMMARY Hydroethanolic extracts of Moringa oleifera effectively inhibit the NO production in LPS induced inflammatory model.M. oleifera crude extracts successfully modulate the production of pro-inflammatory mediators in LPS stimulated macrophages.M. oleifera extracts suppressed the expression of inflammatory mediators in LPS stimulated macrophages. PMID:27013794

  2. Alpinia officinarum Stimulates Osteoblast Mineralization and Inhibits Osteoclast Differentiation.

    PubMed

    Shim, Ki-Shuk; Lee, Chung-Jo; Yim, Nam-Hui; Gu, Min Jung; Ma, Jin Yeul

    2016-01-01

    Alpinia officinarum rhizome has been used as a traditional herbal remedy to treat inflammatory and internal diseases. Based on the previously observed inhibitory effect of A. officinarum rhizome in an arthritis model, we evaluated whether a water extract of A. officinarum rhizome (WEAO) would enhance in vitro osteoblast mineralization using calvarial osteoblast precursor cells or would inhibit in vitro osteoclast differentiation and bone resorption using bone marrow derived macrophages. In osteoblasts, WEAO enhanced the mRNA levels of transcription factor (runt-related transcription factor 2, smad1, smad5, and junB) and marker (bone morphogenetic protein-2, collagen type 1alpha1, and osteocalcin) genes related to osteoblast mineralization, consistent with increased alizarin red S staining intensity. WEAO markedly inhibited osteoclast differentiation by suppressing the receptor activator for nuclear factor-[Formula: see text]B ligand-induced downregulation of inhibitor of DNA binding 2 and V-maf musculoaponeurotic fibrosarcoma oncogene homolog B and the phosphorylation of c-Jun N-terminal kinase, p38, nuclear factor-[Formula: see text]B, c-Src, and Bruton's tyrosine kinase to induce nuclear factor of activated T cells cytoplasmic 1 expression. WEAO also suppressed the resorbing activity of mature osteoclasts by altering actin ring formation. Therefore, the results of this study demonstrate that WEAO stimulates osteoblast mineralization and inhibits osteoclast differentiation. Thus, WEAO may be a promising herbal candidate to treat or prevent pathological bone diseases by regulating the balance between osteoclast and osteoblast activity.

  3. G0S2: A small giant controller of lipolysis and adipose-liver fatty acid flux.

    PubMed

    Zhang, Xiaodong; Heckmann, Bradlee L; Campbell, Latoya E; Liu, Jun

    2017-10-01

    The discovery of adipose triglyceride lipase (ATGL) and its coactivator comparative gene identification-58 (CGI-58) provided a major paradigm shift in the understanding of intracellular lipolysis in both adipocytes and nonadipocyte cells. The subsequent discovery of G0/G1 switch gene 2 (G0S2) as a potent endogenous inhibitor of ATGL revealed a unique mechanism governing lipolysis and fatty acid (FA) availability. G0S2 is highly conserved in vertebrates, and exhibits cyclical expression pattern between adipose tissue and liver that is critical to lipid flux and energy homeostasis in these two tissues. Biochemical and cell biological studies have demonstrated that a direct interaction with ATGL mediates G0S2's inhibitory effects on lipolysis and lipid droplet degradation. In this review we examine evidence obtained from recent in vitro and in vivo studies that lends support to the proof-of-principle concept that G0S2 functions as a master regulator of tissue-specific balance of TG storage vs. mobilization, partitioning of metabolic fuels between adipose and liver, and the whole-body adaptive energy response. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Tumor necrosis factor-alpha inhibits insulin's stimulating effect on glucose uptake and endothelium-dependent vasodilation in humans.

    PubMed

    Rask-Madsen, Christian; Domínguez, Helena; Ihlemann, Nikolaj; Hermann, Thomas; Køber, Lars; Torp-Pedersen, Christian

    2003-10-14

    Inflammatory mechanisms could be involved in the pathogenesis of both insulin resistance and atherosclerosis. Therefore, we aimed at examining whether the proinflammatory cytokine tumor necrosis factor (TNF)-alpha inhibits insulin-stimulated glucose uptake and insulin-stimulated endothelial function in humans. Healthy, lean male volunteers were studied. On each study day, 3 acetylcholine (ACh) or sodium nitroprusside (SNP) dose-response studies were performed by infusion into the brachial artery. Before and during the last 2 dose-response studies, insulin and/or TNF-alpha were coinfused. During infusion of insulin alone for 20 minutes, forearm glucose uptake increased by 220+/-44%. This increase was completely inhibited during coinfusion of TNF-alpha (started 10 min before insulin) with a more pronounced inhibition of glucose extraction than of blood flow. Furthermore, TNF-alpha inhibited the ACh forearm blood flow response (P<0.001), and this inhibition was larger during insulin infusion (P=0.01) but not further increased by NG-monomethyl-L-arginine acetate (P=0.2). Insulin potentiated the SNP response less than the ACh response and the effect of TNF-alpha was smaller (P<0.001); TNF-alpha had no effect on the SNP response without insulin infusion. Thus, TNF-alpha inhibition of the combined response to insulin and ACh was likely mediated through inhibition of NO production. These results support the concept that TNF-alpha could play a role in the development of insulin resistance in humans, both in muscle and in vascular tissue.

  5. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat

    NASA Astrophysics Data System (ADS)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.

    2014-03-01

    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  6. Arginase inhibition reduces interleukin-1β-stimulated vascular smooth muscle cell proliferation by increasing nitric oxide synthase-dependent nitric oxide production

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoon, Jeongyeon; Ryoo, Sungwoo, E-mail: ryoosw08@kangwon.ac.kr

    2013-06-07

    Highlights: •Arginase inhibition suppressed proliferation of IL-1β-stimulated VSMCs in dose-dependent manner. •NO production from IL-1β-induced iNOS expression was augmented by arginase inhibition, reducing VSMC proliferation. •Incubation with cGMP analogues abolished IL-1β-dependent proliferation of VSMCs. -- Abstract: We investigated whether arginase inhibition suppressed interleukin (IL)-1β-stimulated proliferation in vascular smooth muscle cells (VSMCs) and the possible mechanisms involved. IL-1β stimulation increased VSMC proliferation, while the arginase inhibitor BEC and transfection of the antisense (AS) oligonucleotide against arginase I decreased VSMC proliferation and was associated with increased protein content of the cell cycle regulator p21Waf1/Cip1. IL-1β incubation induced inducible nitric oxide synthase (iNOS)more » mRNA expression and protein levels in a dose-dependent manner, but did not affect arginase I and II expression. Consistent with this data, IL-1β stimulation resulted in increase in NO production that was significantly augmented by arginase inhibition. The specific iNOS inhibitor 1400W abolished IL-1β-mediated NO production and further accentuated IL-1β-stimulated cell proliferation. Incubation with NO donors GSNO and DETA/NO in the presence of IL-1β abolished VSMCs proliferation and increased p21Waf1/Cip1 protein content. Furthermore, incubation with the cGMP analogue 8-Br-cGMP prevented IL-1β-induced VSMCs proliferation. In conclusion, arginase inhibition augmented iNOS-dependent NO production that resulted in suppression of IL-1β-induced VSMCs proliferation in a cGMP-dependent manner.« less

  7. Neurotensin stimulates sortilin and mTOR in human microglia inhibitable by methoxyluteolin, a potential therapeutic target for autism.

    PubMed

    Patel, Arti B; Tsilioni, Irene; Leeman, Susan E; Theoharides, Theoharis C

    2016-09-23

    We had reported elevated serum levels of the peptide neurotensin (NT) in children with autism spectrum disorders (ASD). Here, we show that NT stimulates primary human microglia, the resident immune cells of the brain, and the immortalized cell line of human microglia-SV40. NT (10 nM) increases the gene expression and release (P < 0.001) of the proinflammatory cytokine IL-1β and chemokine (C-X-C motif) ligand 8 (CXCL8), chemokine (C-C motif) ligand 2 (CCL2), and CCL5 from human microglia. NT also stimulates proliferation (P < 0.05) of microglia-SV40. Microglia express only the receptor 3 (NTR3)/sortilin and not the NTR1 or NTR2. The use of siRNA to target sortilin reduces (P < 0.001) the NT-stimulated cytokine and chemokine gene expression and release from human microglia. Stimulation with NT (10 nM) increases the gene expression of sortilin (P < 0.0001) and causes the receptor to be translocated from the cytoplasm to the cell surface, and to be secreted extracellularly. Our findings also show increased levels of sortilin (P < 0.0001) in the serum from children with ASD (n = 36), compared with healthy controls (n = 20). NT stimulation of microglia-SV40 causes activation of the mammalian target of rapamycin (mTOR) signaling kinase, as shown by phosphorylation of its substrates and inhibition of these responses by drugs that prevent mTOR activation. NT-stimulated responses are inhibited by the flavonoid methoxyluteolin (0.1-1 μM). The data provide a link between sortilin and the pathological findings of microglia and inflammation of the brain in ASD. Thus, inhibition of this pathway using methoxyluteolin could provide an effective treatment of ASD.

  8. Impaired adipose tissue lipid storage, but not altered lipolysis, contributes to elevated levels of NEFA in type 2 diabetes. Degree of hyperglycemia and adiposity are important factors.

    PubMed

    Pereira, Maria J; Skrtic, Stanko; Katsogiannos, Petros; Abrahamsson, Niclas; Sidibeh, Cherno O; Dahgam, Santosh; Månsson, Marianne; Risérus, Ulf; Kullberg, Joel; Eriksson, Jan W

    2016-12-01

    Elevated levels of circulating non-esterified fatty acids (NEFA) mediate many adverse metabolic effects. In this work we aim to determine the impact of type 2 diabetes (T2D), glycemic control and obesity on lipolysis regulation. 20 control and 20 metformin-treated T2D subjects were matched for sex (10M/10 F), age (58±11 vs 58±9 y) and BMI (30.8±4.6 vs 30.7±4.9kg/m 2 ). In vivo lipolysis was assessed during a 3h-OGTT with plasma glycerol and NEFA levels. Subcutaneous adipose tissue (SAT) biopsies were obtained to measure mRNA and metabolite levels of factors related to lipolysis and lipid storage and to assess in vitro lipolysis in isolated subcutaneous adipocytes. Plasma NEFA AUC during the OGTT where higher 30% (P=0.005) in T2D than in control subjects, but plasma glycerol AUC and subcutaneous adipocyte lipolysis in vitro were similar, suggesting that adipose tissue lipolysis is not altered. Expression in SAT of genes involved in lipid storage (FABP4, DGAT1, FASN) were reduced in T2D subjects compared with controls, but no differences were seen for genes involved in lipolysis. T2D subjects had elevated markers of beta-oxidation, α-hydroxybutyrate (1.4-fold, P<0.01) and β-hydroxybutyrate (1.7-fold, P<0.05) in plasma. In multivariate analysis, HbA1c, visceral adipose tissue volume and sex (male) were significantly associated with NEFA AUC in T2D subjects. In T2D subjects, NEFA turnover is impaired, but not due to defects in lipolysis or lipid beta-oxidation. Impaired adipose NEFA re-esterification or de novo lipogenesis is likely to contribute to higher NEFA plasma levels in T2D. The data suggest that hyperglycemia and adiposity are important contributing factors for the regulation of plasma NEFA concentrations. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. In vitro gastrointestinal lipolysis of four formulations of piroxicam and cinnarizine with the self emulsifying excipients Labrasol and Gelucire 44/14.

    PubMed

    Fernandez, Sylvie; Chevrier, Stéphanie; Ritter, Nicolas; Mahler, Bruno; Demarne, Frédéric; Carrière, Frédéric; Jannin, Vincent

    2009-08-01

    Labrasol and Gelucire 44/14 are defined admixtures of acylglycerols and PEG esters which are substrates for digestive lipases. We investigated their in vitro gastrointestinal lipolysis to understand which compounds are, after digestion, responsible for keeping poorly water-soluble drugs in solution. The precipitation of piroxicam and cinnarizine formulated in these excipients during the gastrointestinal lipolysis was also studied. Monoacylglycerols and PEG monoesters are the largest compounds present at the end of gastric phase whereas PEG-monoesters are the largest compounds after the duodenal phase. The precipitation of piroxicam is mainly due to the gastric lipolysis. In the control experiments performed without digestive lipases, cinnarizine formulated in Labrasol was found to precipitate upon dilution of the gastric medium to form the solution mimicking the duodenal medium. In the presence of gastric lipase, Labrasol was hydrolyzed and the precipitation of cinnarizine was not observed in this case. When the cinnarizine was formulated with Gelucire 44/14 the precipitation was only due to the dilution of the gastric medium. Our study highlights the importance of the gastrointestinal lipolysis and the associated phenomena such as the dilution of chyme by biliary and pancreatic secretions in vivo, on the solubilisation of poorly water-soluble drugs formulated with lipid-based excipients.

  10. A drug-like antagonist inhibits thyrotropin receptor-mediated stimulation of cAMP production in Graves' orbital fibroblasts.

    PubMed

    Neumann, Susanne; Pope, Arthur; Geras-Raaka, Elizabeth; Raaka, Bruce M; Bahn, Rebecca S; Gershengorn, Marvin C

    2012-08-01

    Fibroblasts (FIBs) within the retro-orbital space of patients with Graves' disease (GOFs) express thyrotropin receptors (TSHRs) and are thought to be an orbital target of TSHR-stimulating autoantibodies in Graves' ophthalmopathy (GO). Recently, we developed a low molecular weight, drug-like TSHR antagonist (NCGC00229600) that inhibited TSHR activation in a model cell system overexpressing TSHRs and in normal human thyrocytes expressing endogenous TSHRs. Herein, we test the hypothesis that NCGC00229600 will inhibit activation of TSHRs endogenously expressed in GOFs. Three strains of GOFs, previously obtained from patients with GO, were studied as undifferentiated FIBs and after differentiation into adipocytes (ADIPs), and another seven strains were studied only as FIBs. ADIP differentiation was monitored by morphology and measurement of adiponectin mRNA. FIBs and ADIPs were treated with the TSH- or TSHR-stimulating antibody M22 in the absence or presence of NCGC00229600 and TSHR activation was monitored by cAMP production. FIBs contained few if any lipid vesicles and undetectable levels of adiponectin mRNA, whereas ADIPs exhibited abundant lipid vesicles and levels of adiponectin mRNA more than 250,000 times greater than FIBs; TSHR mRNA levels were 10-fold higher in ADIPs than FIBs. FIBs exhibited higher absolute levels of basal and forskolin-stimulated cAMP production than ADIPs. Consistent with previous findings, TSH stimulated cAMP production in the majority of ADIP strains and less consistently in FIBs. Most importantly, NCGC00229600 reduced both TSH- and M22-stimulated cAMP production in GOFs. These data confirm previous findings that TSHR activation may cause increased cAMP production in GOFs and show that NCGC00229600 can inhibit TSHR activation in GOFs. These findings suggest that drug-like TSHR antagonists may have a role in treatment of GO.

  11. Identification of Interferon-Stimulated Gene Proteins That Inhibit Human Parainfluenza Virus Type 3.

    PubMed

    Rabbani, M A G; Ribaudo, Michael; Guo, Ju-Tao; Barik, Sailen

    2016-12-15

    A major arm of cellular innate immunity is type I interferon (IFN), represented by IFN-α and IFN-β. Type I IFN transcriptionally induces a large number of cellular genes, collectively known as IFN-stimulated gene (ISG) proteins, which act as antivirals. The IFIT (interferon-induced proteins with tetratricopeptide repeats) family proteins constitute a major subclass of ISG proteins and are characterized by multiple tetratricopeptide repeats (TPRs). In this study, we have interrogated IFIT proteins for the ability to inhibit the growth of human parainfluenza virus type 3 (PIV3), a nonsegmented negative-strand RNA virus of the Paramyxoviridae family and a major cause of respiratory disease in children. We found that IFIT1 significantly inhibited PIV3, whereas IFIT2, IFIT3, and IFIT5 were less effective or not at all. In further screening a set of ISG proteins we discovered that several other such proteins also inhibited PIV3, including IFITM1, IDO (indoleamine 2,3-dioxygenase), PKR (protein kinase, RNA activated), and viperin (virus inhibitory protein, endoplasmic reticulum associated, interferon inducible)/Cig5. The antiviral effect of IDO, the enzyme that catalyzes the first step of tryptophan degradation, could be counteracted by tryptophan. These results advance our knowledge of diverse ISG proteins functioning as antivirals and may provide novel approaches against PIV3. The innate immunity of the host, typified by interferon (IFN), is a major antiviral defense. IFN inhibits virus growth by inducing a large number of IFN-stimulated gene (ISG) proteins, several of which have been shown to have specific antiviral functions. Parainfluenza virus type 3 (PIV3) is major pathogen of children, and no reliable vaccine or specific antiviral against it currently exists. In this article, we report several ISG proteins that strongly inhibit PIV3 growth, the use of which may allow a better antiviral regimen targeting PIV3. Copyright © 2016, American Society for Microbiology

  12. The opposing effects of calmodulin, adenosine 5 prime -triphosphate, and pertussis toxin on phorbol ester induced inhibition of atrial natriuretic factor stimulated guanylate cyclase in SK-NEP-1 cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sekiya, M.; Frohlich, E.D.; Cole, F.E.

    1991-01-01

    In the present study, we investigated the effects of calmodulin, adenosine 5{prime}-triphosphate (ATP) and pertussis toxin (PT) on phorbol ester (PMA) induced inhibition of ANF-stimulated cyclic GMP formation in cells from the human renal cell line, SK-NEP-1. PMA inhibited ANF-stimulated guanylate cyclase activity in particulate membranes by about 65%. Calmodulin reversed this inhibition in a dose dependent manner. ATP potentiated Mg++ but not Mn++ supported guanylate cyclase activity. In PMA treated membranes, ATP potentiating effects were abolished. PMA also inhibited ANF-stimulated cGMP accumulation, but pretreatment with PT prevented this PMA inhibition. PT did not affect basal or ANF-stimulated cGMP accumulation.more » In conclusion, these results demonstrated that PMA inhibited ANF stimulation of particulate guanylate cyclase in opposition to the activating effects of calmodulin or ATP in SK-NEP-1 cells. The protein kinase C inhibitory effects appeared to be mediated via a PT-sensitive G protein.« less

  13. Combination of Garcinia cambogia Extract and Pear Pomace Extract Additively Suppresses Adipogenesis and Enhances Lipolysis in 3T3-L1 Cells.

    PubMed

    Sharma, Kushal; Kang, Siwon; Gong, Dalseong; Oh, Sung-Hwa; Park, Eun-Young; Oak, Min-Ho; Yi, Eunyoung

    2018-01-01

    Inhibition of adipogenesis has been a therapeutic target for reducing obesity and obesity-related disorders such as diabetes, hypertension, atherosclerosis, and cancer. For decades, anti-adipogenic potential of many herbal extracts has been investigated. One example is Garcinia cambogia extract (GE) containing (-)-hydroxycitric acid as an active ingredient. GE is currently marketed as a weight loss supplement, used alone or with other ingredients. Pear pomace extract (PE), another natural product, has been also shown to have anti-adipogenic activity in a recent report. It was tested if the mixture of PE and GE (MIX) would produce more effective anti-adipogenic activity than PE or GE alone. Differentiation of 3T3-L1 preadipocyte was induced by adding insulin, dexamethasone, and isobutylmethylxanthine and lipid accumulation was measured by Oil Red O staining. Cellular markers for adipogenesis and lipolysis such as CCAAT/enhancer binding protein (C/EBP-α), peroxisome proliferator-activated receptor gamma (PPAR-γ), fatty acid synthase (FAS), and hormone-sensitive lipase (HSL) was measured using immunocytochemistry. MIX, compared to PE or GE alone, showed greater inhibition of lipid accumulation. Furthermore, MIX reduced the expression of adipogenesis-related factors C/EBP-α, PPAR-γ, and FAS more than PE or GE alone did. In contrast, the expression of HSL the enzyme required for lipolysis was further enhanced in MIX-treated adipocytes compared to the PE or GE alone treated groups. Anti-adipogenic effect of PE and GE appears synergistic, and the MIX may be a useful therapeutic combination for the treatment of obesity and obesity-related diseases. PE and GE efficiently inhibited adipocyte differentiation by suppressing the expression of adipogenic transcription factor CEBP-α and PPAR-γ.PE and GE significantly decreased the expression of adipogenic enzyme FAS.PE and GE increased the expression of lipid degrading enzyme HSL.Mixture of PE and GE exhibited additive or

  14. Activation of milk lipase by serum proteins: possible role in the occurrence of lipolysis in raw bovine milk.

    PubMed

    Clegg, R A

    1980-02-01

    The increase in unesterified fatty acid content of unpasteurized bulk milk in storage at 4 degrees C in the presence of known effectors of bovine milk lipoprotein lipase originating from bovine serum was studied. Bovine serum and high density lipoprotein (HDL) caused an increase in developed unesterified fatty acid levels whilst lipoprotein-free serum, apo-HDL, all individual apo-HDL tested, and the unfractionated C-peptide fraction were without lipolytic effect. In the presence of HDL-lipids, 2 C-peptides stimulated considerable lipolysis, as did the combination of HDL-lipid with unfractionated C-peptides. These characteristics of unesterified fatty acid development could be duplicated in milk whose endogenous lipolytic activity had been destroyed by heat treatment (75 degrees C for 5 min) and then restored by addition of purified bovine milk lipoprotein lipase. Radioactively labelled glycerol trioleate in milk was not hydrolysed in the same way as milk fat on the addition of serum liproproteins.

  15. Modulation of adipocyte biology by δ(9)-tetrahydrocannabinol.

    PubMed

    Teixeira, Diana; Pestana, Diogo; Faria, Ana; Calhau, Conceição; Azevedo, Isabel; Monteiro, Rosário

    2010-11-01

    It is recognized that the endocannabinoid system (ECS) plays a crucial role in the modulation of food intake and other aspects of energy metabolism. In this study, we aimed to investigate the effects of Δ(9)-tetrahydrocannabinol (THC) on adipocyte biology. 3T3-L1 cells were used to evaluate proliferation by sulforhodamine B (SRB) staining and methyl-(3)H-thymidine incorporation after 48 or 72 h of treatment with THC (1-500 nmol/l). Cells were differentiated in the presence or absence of the cannabinoid, and adipogenesis was determined by measuring lipid accumulation and peroxisome proliferator-activated receptor γ (PPARγ) transcription through reverse transcriptase-PCR (RT-PCR). Lipolysis was quantified under basal conditions or after isoproterenol (IP, 100 nmol/l) or insulin (INS, 100 nmol/l) treatment. Transforming growth factor β (TGFβ), diacylglycerol lipase α, and N-acylphosphatidylethanolamine-specific phospholipase D (NAPE-PLD) transcriptions were determined by RT-PCR in preadipocytes and adipocytes and adiponectin only in adipocytes. THC treatment increased culture protein content and reduced methyl-(3)H-thymidine incorporation. Cells treated with THC underwent adipogenesis shown by the expression of PPARγ and had increased lipid accumulation. Basal and IP-stimulated lipolyses were inhibited by THC and there was no effect on lipolysis of INS-treated adipocytes. The effects on methyl-(3)H-thymidine incorporation and lipolysis seem to be mediated through CB1- and CB2-dependent pathways. THC decreased NAPE-PLD in preadipocytes and increased adiponectin and TGFβ transcription in adipocytes. These results show that the ECS interferes with adipocyte biology and may contribute to adipose tissue (AT) remodeling. Although these observations point toward increased AT deposition, the stimulation of adiponectin production and inhibition of lipolysis may be in favor of improved INS sensitivity under cannabinoid influence.

  16. Histologic evaluation of laser lipolysis: pulsed 1064-nm Nd:YAG laser versus cw 980-nm diode laser.

    PubMed

    Mordon, Serge; Eymard-Maurin, Anne Françoise; Wassmer, Benjamin; Ringot, Jean

    2007-01-01

    The use of the laser as an auxiliary tool has refined the traditional technique for lipoplasty. During laser lipolysis, the interaction between the laser and the fat produced direct cellular destruction before the suction, reduced bleeding, and promoted skin tightening. This study sought to perform a comparative histologic evaluation of laser lipolysis with the pulsed 1064-nm Nd:YAG laser versus a continuous 980-nm diode laser. A pulsed 1064-nm Nd:YAG (Smart-Lipo; Deka, Italy) and a CW 980-nm diode laser (Pharaon, Osyris, France) were evaluated at different energy settings for lipolysis on the thighs of a fresh cadaver. The lasers were coupled to a 600-microm optical fiber inserted in a 1-mm diameter cannula. Biopsy specimens were taken on irradiated and non-irradiated areas. Hematoxylin-erythrosin-safran staining and immunostaining (anti-PS100 polyclonal antibody) were performed to identify fat tissue damage. In the absence of laser exposures (control specimens), cavities created by cannulation were seen; adipocytes were round in appearance and not deflated. At low energy settings, tumescent adipocytes were observed. At higher energy settings, cytoplasmic retraction, disruption of membranes, and heat-coagulated collagen fibers were noted; coagulated blood cells were also present. For the highest energy settings, carbonization of fat tissue involving fibers and membranes was clearly seen. For equivalent energy settings, 1064-nm and 980-nm wavelengths gave similar histologic results. Laser lipolysis is a relatively new technique that is still under development. Our histologic findings suggest several positive benefits of the laser, including skin retraction and a reduction in intraoperative bleeding. The interaction of the laser with the tissue is similar at 980 nm and 1064 nm with the same energy settings. Because higher volumes of fat are removed with higher total energy, a high-power 980-nm diode laser could offer an interesting alternative to the 1064-nm Nd

  17. Docosahexaenoic acid inhibits IL-6 expression via PPARγ-mediated expression of catalase in cerulein-stimulated pancreatic acinar cells.

    PubMed

    Song, Eun Ah; Lim, Joo Weon; Kim, Hyeyoung

    2017-07-01

    Cerulein pancreatitis mirrors human acute pancreatitis. In pancreatic acinar cells exposed to cerulein, reactive oxygen species (ROS) mediate inflammatory signaling by Janus kinase (JAK) 2/signal transducer and activator of transcription (STAT) 3, and cytokine induction. Docosahexaenoic acid (DHA) acts as an agonist of peroxisome proliferator activated receptor γ (PPARγ), which mediates the expression of some antioxidant enzymes. We hypothesized that DHA may induce PPARγ-target catalase expression and reduce ROS levels, leading to the inhibition of JAK2/STAT3 activation and IL-6 expression in cerulein-stimulated acinar cells. Pancreatic acinar AR42J cells were treated with DHA in the presence or absence of the PPARγ antagonist GW9662, or treated with the PPARγ agonist troglitazone, and then stimulated with cerulein. Expression of IL-6 and catalase, ROS levels, JAK2/STAT3 activation, and nuclear translocation of PPARγ were assessed. DHA suppressed the increase in ROS, JAK2/STAT3 activation, and IL-6 expression induced nuclear translocation of PPARγ and catalase expression in cerulein-stimulated AR42J cells. Troglitazone inhibited the cerulein-induced increase in ROS and IL-6 expression, but induced catalase expression similar to DHA in AR42J cells. GW9662 abolished the inhibitory effect of DHA on cerulein-induced increase in ROS and IL-6 expression in AR42J cells. DHA-induced expression of catalase was suppressed by GW9662 in cerulein-stimulated AR42J cells. Thus, DHA induces PPARγ activation and catalase expression, which inhibits ROS-mediated activation of JAK2/STAT3 and IL-6 expression in cerulein-stimulated pancreatic acinar cells. Copyright © 2017. Published by Elsevier Ltd.

  18. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements.

    PubMed

    Liu, Yitong; Santillo, Michael F

    2016-01-01

    A number of dietary supplements used for weight loss and athletic performance enhancement have been recently shown to contain a variety of stimulants, for which there is a lack of pharmacological and toxicological information. One concern for these emerging compounds is their potential to inhibit metabolic enzymes in the liver such as cytochromes P450 (CYP), which can lead to unexpected interactions among dietary supplements, drugs, and other xenobiotics. In this study, inhibition of human recombinant CYP2D6 and CYP3A4 by 27 amine stimulants associated with dietary supplements and their analogs was evaluated by luminescence assays. The strongest CYP2D6 inhibitors were coclaurine (IC50  = 0.14 ± 0.01 μM) and N-benzylphenethylamine (IC50  = 0.7 ± 0.2 μM), followed by several other relatively strong inhibitors (IC50 , 2-12 μM) including β-methylphenethylamine, N,β-dimethylphenethylamine (phenpromethamine), 1,3-dimethylamylamine (DMAA), N,α-diethylphenethylamine, higenamine (norcoclaurine) and N,N-diethylphenethylamine. Only nine compounds inhibited CYP3A4 by 20-55% at 100 μM. Results of this study illustrate that several amine stimulants associated with dietary supplements inhibit CYP2D6 and CYP3A4 in vitro, and these compounds may participate in adverse drug-dietary supplement interactions in vivo. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Adaptive threshold hunting for the effects of transcranial direct current stimulation on primary motor cortex inhibition.

    PubMed

    Mooney, Ronan A; Cirillo, John; Byblow, Winston D

    2018-06-01

    Primary motor cortex excitability can be modulated by anodal and cathodal transcranial direct current stimulation (tDCS). These neuromodulatory effects may, in part, be dependent on modulation within gamma-aminobutyric acid (GABA)-mediated inhibitory networks. GABAergic function can be quantified non-invasively using adaptive threshold hunting paired-pulse transcranial magnetic stimulation (TMS). The previous studies have used TMS with posterior-anterior (PA) induced current to assess tDCS effects on inhibition. However, TMS with anterior-posterior (AP) induced current in the brain provides a more robust measure of GABA-mediated inhibition. The aim of the present study was to assess the modulation of corticomotor excitability and inhibition after anodal and cathodal tDCS using TMS with PA- and AP-induced current. In 16 young adults (26 ± 1 years), we investigated the response to anodal, cathodal, and sham tDCS in a repeated-measures double-blinded crossover design. Adaptive threshold hunting paired-pulse TMS with PA- and AP-induced current was used to examine separate interneuronal populations within M1 and their influence on corticomotor excitability and short- and long-interval inhibition (SICI and LICI) for up to 60 min after tDCS. Unexpectedly, cathodal tDCS increased corticomotor excitability assessed with AP (P = 0.047) but not PA stimulation (P = 0.74). SICI AP was reduced after anodal tDCS compared with sham (P = 0.040). Pearson's correlations indicated that SICI AP and LICI AP modulation was associated with corticomotor excitability after anodal (P = 0.027) and cathodal tDCS (P = 0.042). The after-effects of tDCS on corticomotor excitability may depend on the direction of the TMS-induced current used to make assessments, and on modulation within GABA-mediated inhibitory circuits.

  20. Sirtuin inhibition attenuates the production of inflammatory cytokines in lipopolysaccharide-stimulated macrophages

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fernandes, Claudia A.; Fievez, Laurence; Neyrinck, Audrey M.

    Highlights: Black-Right-Pointing-Pointer Lipopolysaccharide-stimulated macrophages were treated with cambinol and sirtinol. Black-Right-Pointing-Pointer Cambinol and sirtinol decreased lipopolysaccharide-induced cytokines. Black-Right-Pointing-Pointer Cambinol decreased NF-{kappa}B activity but had no impact on p38 MAPK activation. Black-Right-Pointing-Pointer Sirtuins are an interesting target for the treatment of inflammatory diseases. -- Abstract: In several inflammatory conditions such as rheumatoid arthritis or sepsis, the regulatory mechanisms of inflammation are inefficient and the excessive inflammatory response leads to damage to the host. Sirtuins are class III histone deacetylases that modulate the activity of several transcription factors that are implicated in immune responses. In this study, we evaluated the impact ofmore » sirtuin inhibition on the activation of lipopolysaccharide (LPS)-stimulated J774 macrophages by assessing the production of inflammatory cytokines. The pharmacologic inhibition of sirtuins decreased the production of tumour necrosis factor-alpha (TNF-{alpha}) interleukin 6 (IL-6) and Rantes. The reduction of cytokine production was associated with decreased nuclear factor kappa B (NF-{kappa}B) activity and inhibitor kappa B alpha (I{kappa}B{alpha}) phosphorylation while no impact was observed on the phosphorylation status of p38 mitogen-activated kinase (p38 MAPK). This work shows that sirtuin pharmacologic inhibitors are a promising tool for the treatment of inflammatory conditions.« less

  1. The role of cGMP as a mediator of lipolysis in bovine oocytes and its effects on embryo development and cryopreservation.

    PubMed

    Schwarz, Kátia R L; de Castro, Fernanda C; Schefer, Letícia; Botigelli, Ramon C; Paschoal, Daniela M; Fernandes, Hugo; Leal, Cláudia L V

    2018-01-01

    This study aimed to determine the influence of cyclic guanosine 3'5'-monophosphate (cGMP) and cGMP-dependent kinase (PKG) during in vitro maturation (IVM) on lipolysis-related parameters in bovine cumulus-oocyte complexes (COCs), and on embryo development and cryosurvival. COCs were matured with cGMP/PKG modulators and assessed for metaphase II rates (MII), cGMP levels, lipid content in oocytes (OO), transcript abundance for genes involved in lipolysis (ATGL) and lipid droplets (PLIN2) in cumulus cells (CC) and OO, and presence of phosphorylated (active) hormone sensitive lipase (HSLser563) in OO. Embryo development, lipid contents and survival to vitrification were also assessed. Phosphodiesterase 5 inhibition (PDE5; cGMP-hydrolyzing enzyme) with 10-5M sildenafil (SDF) during 24 h IVM increased cGMP in COCs (56.9 vs 9.5 fMol/COC in untreated controls, p<0.05) and did not affect on maturation rate (84.3±6.4% MII). Fetal calf serum (FCS) in IVM medium decreased cGMP in COCs compared to bovine serum albumin (BSA) + SDF (19.6 vs 66.5 fMol/COC, respectively, p<0.05). FCS increased lipid content in OO (40.1 FI, p<0.05) compared to BSA (34.6 FI), while SDF decreased (29.8 and 29.6 FI, with BSA or FCS, respectively p<0.05). PKG inhibitor (KT5823) reversed this effect (38.9 FI, p<0.05). ATGL and PLIN2 transcripts were detected in CC and OO, but were affected by cGMP and PKG only in CC. HSLser563 was detected in OO matured with or without modulators. Reduced lipid content in embryos were observed only when SDF was added during IVM and IVC (27.6 FI) compared to its use in either or none of the culture periods (34.2 FI, p<0.05). Survival to vitrification was unaffected by SDF. In conclusion, cGMP and PKG are involved in lipolysis in OO and possibly in CC and embryos; serum negatively affects this pathway, contributing to lipid accumulation, and cGMP modulation may reduce lipid contents in oocytes and embryos, but without improving embryo cryotolerance.

  2. Cerebellar theta burst stimulation modulates short latency afferent inhibition in Alzheimer's disease patients

    PubMed Central

    Di Lorenzo, Francesco; Martorana, Alessandro; Ponzo, Viviana; Bonnì, Sonia; D'Angelo, Egidio; Caltagirone, Carlo; Koch, Giacomo

    2013-01-01

    The dysfunction of cholinergic neurons is a typical hallmark in Alzheimer's disease (AD). Previous findings demonstrated that high density of cholinergic receptors is found in the thalamus and the cerebellum compared with the cerebral cortex and the hippocampus. We aimed at investigating whether activation of the cerebello-thalamo-cortical pathway by means of cerebellar theta burst stimulation (TBS) could modulate central cholinergic functions evaluated in vivo by using the neurophysiological determination of Short-Latency Afferent Inhibition (SLAI). We tested the SLAI circuit before and after administration of cerebellar continuous TBS (cTBS) in 12 AD patients and in 12 healthy age-matched control subjects (HS). We also investigated potential changes of intracortical circuits of the contralateral primary motor cortex (M1) by assessing short intracortical inhibition (SICI) and intracortical facilitation (ICF). SLAI was decreased in AD patients compared to HS. Cerebellar cTBS partially restored SLAI in AD patients at later inter-stimulus intervals (ISIs), but did not modify SLAI in HS. SICI and ICF did not differ in the two groups and were not modulated by cerebellar cTBS. These results demonstrate that cerebellar magnetic stimulation is likely to affect mechanisms of cortical cholinergic activity, suggesting that the cerebellum may have a direct influence on the cholinergic dysfunction in AD. PMID:23423358

  3. Bilateral stimulation of the subthalamic nucleus has differential effects on reactive and proactive inhibition and conflict-induced slowing in Parkinson's disease.

    PubMed

    Obeso, Ignacio; Wilkinson, Leonora; Rodríguez-Oroz, Maria-Cruz; Obeso, Jose A; Jahanshahi, Marjan

    2013-05-01

    It has been proposed that the subthalamic nucleus (STN) mediates response inhibition and conflict resolution through the fronto-basal ganglia pathways. Our aim was to compare the effects of deep brain stimulation (DBS) of the STN on reactive and proactive inhibition and conflict resolution in Parkinson's disease using a single task. We used the conditional Stop signal reaction time task that provides the Stop signal reaction time (SSRT) as a measure of reactive inhibition, the response delay effect (RDE) as a measure of proactive inhibition and conflict-induced slowing (CIS) as a measure of conflict resolution. DBS of the STN significantly prolonged SSRT relative to stimulation off. However, while the RDE measure of proactive inhibition was not significantly altered by DBS of the STN, relative to healthy controls, RDE was significantly lower with DBS off but not DBS on. DBS of the STN did not alter the mean CIS but produced a significant differential effect on the slowest and fastest RTs on conflict trials, further prolonging the slowest RTs on the conflict trials relative to DBS off and to controls. These results are the first demonstration, using a single task in the same patient sample, that DBS of the STN produces differential effects on reactive and proactive inhibition and on conflict resolution, suggesting that these effects are likely to be mediated through the impact of STN stimulation on different fronto-basal ganglia pathways: hyperdirect, direct and indirect.

  4. Differential effects of progesterone and genital stimulation on sequential inhibition of estrous behavior and progesterone receptor expression in the rat brain.

    PubMed

    Gómez-Camarillo, Madaí A; Beyer, Carlos; Lucio, Rosa Angélica; García-Juárez, Marcos; González-Arenas, Aliesha; Camacho-Arroyo, Ignacio; Komisaruk, Barry R; González-Flores, Oscar

    2011-05-30

    The effect of genital stimulation, either by vaginocervical stimulation (VCS) using a calibrated vaginal probe combined with manual flank stimulation (FS), or by mounts performed by the male, on the hypothalamus and preoptic area concentration of the progesterone receptors A (PR-A) and B (PR-B) was assessed in ovariectomized (ovx) estrogen-primed rats. VCS/FS or stimulation provided by male mounts, even without intromission, significantly decreased PR-B concentration in the hypoythalamus. Down regulation of PR produced by genital stimulation was quantitatively similar to that elicited by progesterone (P) administration. Bilateral or unilateral transection of the pelvic or the pudendal nerves prevented down regulation elicited by VCS/FS. Repeated VCS/FS elicited lordosis behavior in most ovx estrogen primed rats, but the lordosis intensity was lower than that observed in response to P. P administered to ovx estrogen primed rats, induced sequential inhibition, i.e., failure to display estrous behavior in response to a second P injection (24h after the initial P injection). VCS/FS failed to elicit sequential inhibition, since rats responded with normal estrous behavior to the second injection of P. This suggests that down regulation by VCS, by contrast with P, failed to inhibit the subpopulation of PR involved in the facilitation of estrous behavior by P. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Reinforcement and Stimulant Medication Ameliorate Deficient Response Inhibition in Children with Attention-Deficit/Hyperactivity Disorder.

    PubMed

    Rosch, Keri S; Fosco, Whitney D; Pelham, William E; Waxmonsky, James G; Bubnik, Michelle G; Hawk, Larry W

    2016-02-01

    This study examined the degree to which reinforcement, stimulant medication, and their combination impact response inhibition in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Across three studies, participants with ADHD (n = 111, 25 girls) and typically-developing (TD) controls (n = 33, 6 girls) completed a standard version of the stop signal task (SST) and/or a reinforcement-manipulation SST with performance-contingent points. In two of these studies, these tasks were performed under placebo or 0.3 and 0.6 mg/kg methylphenidate (MPH) conditions. Cross-study comparisons were conducted to test hypotheses regarding the separate and combined effects of reinforcement and methylphenidate on response inhibition among children with ADHD relative to TD controls. Baseline response inhibition was worse among children with ADHD compared to controls. MPH produced dose-related improvements in response inhibition in children with ADHD; compared to non-medicated TD controls, 0.3 mg/kg MPH normalized deficient response inhibition, and 0.6 mg/kg MPH resulted in better inhibition in children with ADHD. Reinforcement improved response inhibition to a greater extent for children with ADHD than for TD children, normalizing response inhibition. The combination of MPH and reinforcement improved response inhibition among children with ADHD compared to reinforcement alone and MPH alone, also resulting in normalization of response inhibition despite repeated task exposure. Deficient response inhibition commonly observed in children with ADHD is significantly improved with MPH and/or reinforcement, normalizing inhibition relative to TD children tested under standard conditions.

  6. Reinforcement and stimulant medication ameliorate deficient response inhibition in children with Attention-Deficit/Hyperactivity Disorder

    PubMed Central

    Rosch, Keri S.; Fosco, Whitney D.; Pelham, William E.; Waxmonsky, James G.; Bubnik, Michelle G.; Hawk, Larry W.

    2015-01-01

    This study examined the degree to which reinforcement, stimulant medication, and their combination impact response inhibition in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Across three studies, participants with ADHD (n=111, 25 girls) and typically-developing (TD) controls (n=33, 6 girls) completed a standard version of the stop signal task (SST) and/or a reinforcement-manipulation SST with performance-contingent points. In two of these studies, these tasks were performed under placebo or 0.3 and 0.6 mg/kg methylphenidate (MPH) conditions. Cross-study comparisons were conducted to test hypotheses regarding the separate and combined effects of reinforcement and methylphenidate on response inhibition among children with ADHD relative to TD controls. Baseline response inhibition was worse among children with ADHD compared to controls. MPH produced dose-related improvements in response inhibition in children with ADHD; compared to non-medicated TD controls, 0.3 mg/kg MPH normalized deficient response inhibition, and 0.6 mg/kg MPH resulted in better inhibition in children with ADHD. Reinforcement improved response inhibition to a greater extent for children with ADHD than for TD children, normalizing response inhibition. The combination of MPH and reinforcement improved response inhibition among children with ADHD compared to reinforcement alone and MPH alone, also resulting in normalization of response inhibition despite repeated task exposure. Deficient response inhibition commonly observed in children with ADHD is significantly improved with MPH and/or reinforcement, normalizing inhibition relative to TD children tested under standard conditions. PMID:25985978

  7. Instant polysaccharide-based emulsions: impact of microstructure on lipolysis.

    PubMed

    Torcello-Gómez, Amelia; Foster, Timothy J

    2017-06-21

    The development of emulsion-based products through optimisation of ingredients, reduction in energy-input during manufacture, while fulfilling healthy attributes, are major objectives within the food industry. Instant emulsions can meet these features, but comprehensive studies are necessary to investigate the effect of the initial formulation on the final microstructure and, in turn, on the in vitro lipolysis, comprising the double aim of this work. The instant emulsion is formed within 1.5-3 min after pouring the aqueous phase into the oil phase which contains a mixture of emulsifier (Tween 20), swelling particles (Sephadex) and thickeners (hydroxypropylmethylcellulose, HPMC, and guar gum, GG) under mild shearing (180 rpm). The creation of oil-in-water emulsions is monitored in situ by viscosity analysis, the final microstructure visualised by microscopy and the release of free fatty acids under simulated intestinal conditions quantified by titration. Increasing the concentration and molecular weight (M w ) of GG leads to smaller emulsion droplets due to increased bulk viscosity upon shearing. This droplet size reduction is magnified when increasing the M w of HPMC or swelling capacity of viscosifying particles. In addition, in the absence of the emulsifier Tween 20, the sole use of high-Mw HPMC is effective in emulsification due to combined increased bulk viscosity and interfacial activity. Hence, optimisation of the ingredient choice and usage level is possible when designing microstructures. Finally, emulsions with larger droplet size (>20 μm) display a slower rate and lower extent of lipolysis, while finer emulsions (droplet size ≤20 μm) exhibit maximum rate and extent profiles. This correlates with the extent of emulsion destabilisation observed under intestinal conditions.

  8. Arginase Inhibition Suppresses Native Low-Density Lipoprotein-Stimulated Vascular Smooth Muscle Cell Proliferation by NADPH Oxidase Inactivation.

    PubMed

    Koo, Bon Hyeock; Yi, Bong Gu; Wang, Wi Kwang; Ko, In Young; Hoe, Kwang Lae; Kwon, Young Guen; Won, Moo Ho; Kim, Young Myeong; Lim, Hyun Kyo; Ryoo, Sungwoo

    2018-05-01

    Vascular smooth muscle cell (VSMC) proliferation induced by native low-density lipoprotein (nLDL) stimulation is dependent on superoxide production from activated NADPH oxidase. The present study aimed to investigate whether the novel arginase inhibitor limonin could suppress nLDL-induced VSMC proliferation and to examine related mechanisms. Isolated VSMCs from rat aortas were treated with nLDL, and cell proliferation was measured by WST-1 and BrdU assays. NADPH oxidase activation was evaluated by lucigenin-induced chemiluminescence, and phosphorylation of protein kinase C (PKC) βII and extracellular signal-regulated kinase (ERK) 1/2 was determined by western blot analysis. Mitochondrial reactive oxygen species (ROS) generation was assessed using MitoSOX-red, and intracellular L-arginine concentrations were determined by high-performance liquid chromatography (HPLC) in the presence or absence of limonin. Limonin inhibited arginase I and II activity in the uncompetitive mode, and prevented nLDL-induced VSMC proliferation in a p21Waf1/Cip1-dependent manner without affecting arginase protein levels. Limonin blocked PKCβII phosphorylation, but not ERK1/2 phosphorylation, and translocation of p47phox to the membrane was decreased, as was superoxide production in nLDL-stimulated VSMCs. Moreover, mitochondrial ROS generation was increased by nLDL stimulation and blocked by preincubation with limonin. Mitochondrial ROS production was responsible for the phosphorylation of PKCβII. HPLC analysis showed that arginase inhibition with limonin increases intracellular L-arginine concentrations, but decreases polyamine concentrations. L-Arginine treatment prevented PKCβII phosphorylation without affecting ERK1/2 phosphorylation. Increased L-arginine levels following limonin-dependent arginase inhibition prohibited NADPH oxidase activation in a PKCβII-dependent manner, and blocked nLDL-stimulated VSMC proliferation. © Copyright: Yonsei University College of Medicine 2018.

  9. Arginase Inhibition Suppresses Native Low-Density Lipoprotein-Stimulated Vascular Smooth Muscle Cell Proliferation by NADPH Oxidase Inactivation

    PubMed Central

    Wang, Wi-Kwang; Ko, In-Young; Hoe, Kwang-Lae; Kwon, Young-Guen; Won, Moo-Ho; Kim, Young-Myeong

    2018-01-01

    Purpose Vascular smooth muscle cell (VSMC) proliferation induced by native low-density lipoprotein (nLDL) stimulation is dependent on superoxide production from activated NADPH oxidase. The present study aimed to investigate whether the novel arginase inhibitor limonin could suppress nLDL-induced VSMC proliferation and to examine related mechanisms. Materials and Methods Isolated VSMCs from rat aortas were treated with nLDL, and cell proliferation was measured by WST-1 and BrdU assays. NADPH oxidase activation was evaluated by lucigenin-induced chemiluminescence, and phosphorylation of protein kinase C (PKC) βII and extracellular signal-regulated kinase (ERK) 1/2 was determined by western blot analysis. Mitochondrial reactive oxygen species (ROS) generation was assessed using MitoSOX-red, and intracellular L-arginine concentrations were determined by high-performance liquid chromatography (HPLC) in the presence or absence of limonin. Results Limonin inhibited arginase I and II activity in the uncompetitive mode, and prevented nLDL-induced VSMC proliferation in a p21Waf1/Cip1-dependent manner without affecting arginase protein levels. Limonin blocked PKCβII phosphorylation, but not ERK1/2 phosphorylation, and translocation of p47phox to the membrane was decreased, as was superoxide production in nLDL-stimulated VSMCs. Moreover, mitochondrial ROS generation was increased by nLDL stimulation and blocked by preincubation with limonin. Mitochondrial ROS production was responsible for the phosphorylation of PKCβII. HPLC analysis showed that arginase inhibition with limonin increases intracellular L-arginine concentrations, but decreases polyamine concentrations. L-Arginine treatment prevented PKCβII phosphorylation without affecting ERK1/2 phosphorylation. Conclusion Increased L-arginine levels following limonin-dependent arginase inhibition prohibited NADPH oxidase activation in a PKCβII-dependent manner, and blocked nLDL-stimulated VSMC proliferation. PMID

  10. ER Stress Inhibits Liver Fatty Acid Oxidation while Unmitigated Stress Leads to Anorexia-Induced Lipolysis and Both Liver and Kidney Steatosis.

    PubMed

    DeZwaan-McCabe, Diane; Sheldon, Ryan D; Gorecki, Michelle C; Guo, Deng-Fu; Gansemer, Erica R; Kaufman, Randal J; Rahmouni, Kamal; Gillum, Matthew P; Taylor, Eric B; Teesch, Lynn M; Rutkowski, D Thomas

    2017-05-30

    The unfolded protein response (UPR), induced by endoplasmic reticulum (ER) stress, regulates the expression of factors that restore protein folding homeostasis. However, in the liver and kidney, ER stress also leads to lipid accumulation, accompanied at least in the liver by transcriptional suppression of metabolic genes. The mechanisms of this accumulation, including which pathways contribute to the phenotype in each organ, are unclear. We combined gene expression profiling, biochemical assays, and untargeted lipidomics to understand the basis of stress-dependent lipid accumulation, taking advantage of enhanced hepatic and renal steatosis in mice lacking the ER stress sensor ATF6α. We found that impaired fatty acid oxidation contributed to the early development of steatosis in the liver but not the kidney, while anorexia-induced lipolysis promoted late triglyceride and free fatty acid accumulation in both organs. These findings provide evidence for both direct and indirect regulation of peripheral metabolism by ER stress. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Effects of laser-assisted lipolysis on nipple-areola complex.

    PubMed

    Sönmez Ergün, Selma; Kayan, Reşit Burak; Güleş, Mustafa Ekrem; Kuzu, İsmail Melih

    2017-08-01

    Gynecomastia, as a most common benign condition, represents itself as the enlargement of the male breast and also nipple-areola complex as the severity of the condition increases. With this study, we aimed to clarify the effects of 980-nm diode laser on nipple-areola complex (NAC). Although numerous open techniques have been described to correct gynecomastia, nowadays trends have shifted to minimally invasive techniques such as laser-assisted lipolysis (LAL). A total of 25 patients with bilateral gynecomastia treated with LAL by using a 980-nm diode laser. The resultant contour and reduced size of the complex were satisfactory. LAL leads to significant reduction of the size of NAC.

  12. Perilipin overexpression in mice protects against diet-induced obesity

    USDA-ARS?s Scientific Manuscript database

    Perilipin A is the most abundant phosphoprotein on adipocyte lipid droplets and is essential for lipid storage and lipolysis. Perilipin null mice exhibit diminished adipose tissue, elevated basal lipolysis, reduced catecholamine-stimulated lipolysis, and increased insulin resistance. To understand t...

  13. Co-culture with human synovium-derived mesenchymal stem cells inhibits inflammatory activity and increases cell proliferation of sodium nitroprusside-stimulated chondrocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ryu, Jae-Sung; Jung, Yeon-Hwa; Cho, Mi-Young

    Highlights: • Co-culture of hSDMSCs with SNP-stimulated chondrocytes improves anti-inflammation. • Co-culture system produces IGF-1. • Co-culture system suppresses inflammatory genes expression. • Co-culture system improves cell proliferation. • Exogenous IGF-1 inhibits inflammatory activity in SNP-stimulated chondrocytes. - Abstract: Rheumatoid arthritis (RA) and osteoarthritis (OA) are primarily chronic inflammatory diseases. Mesenchymal stem cells (MSCs) have the ability to differentiate into cells of the mesodermal lineage, and to regulate immunomodulatory activity. Specifically, MSCs have been shown to secrete insulin-like growth factor 1 (IGF-1). The purpose of the present study was to examine the inhibitory effects on inflammatory activity from a co-culturemore » of human synovium-derived mesenchymal stem cells (hSDMSCs) and sodium nitroprusside (SNP)-stimulated chondrocytes. First, chondrocytes were treated with SNP to generate an in vitro model of RA or OA. Next, the co-culture of hSDMSCs with SNP-stimulated chondrocytes reduced inflammatory cytokine secretion, inhibited expression of inflammation activity-related genes, generated IGF-1 secretion, and increased the chondrocyte proliferation rate. To evaluate the effect of IGF-1 on inhibition of inflammation, chondrocytes pre-treated with IGF-1 were treated with SNP, and then the production of inflammatory cytokines was analyzed. Treatment with IGF-1 was shown to significantly reduce inflammatory cytokine secretion in SNP-stimulated chondrocytes. Our results suggest that hSDMSCs offer a new strategy to promote cell-based cartilage regeneration in RA or OA.« less

  14. Oxygen Inhibition of Photosynthesis and Stimulation of Photorespiration in Soybean Leaf Cells

    PubMed Central

    Servaites, Jerome C.; Ogren, William L.

    1978-01-01

    The occurrence of photorespiration in soybean (Glycine max [L.] Merr.) leaf cells was demonstrated by the presence of an O2-dependent CO2 compensation concentration, a nonlinear time course for photosynthetic 14CO2 uptake at low CO2 and high O2 concentrations, and an O2 stimulation of glycine and serine synthesis which was reversed by high CO2 concentration. The compensation concentration was a linear function of O2 concentration and increased as temperature increased. At atmospheric CO2 concentration, 21% O2 inhibited photosynthesis at 25 C by 27%. Oxygen inhibition of photosynthesis was competitive with respect to CO2 and increased with increasing temperature. The Km (CO2) of photosynthesis was also temperature-dependent, increasing from 12 μm CO2 at 15 C to 38 μm at 35 C. In contrast, the Ki (O2) was similar at all temperatures. Oxygen inhibition of photosynthesis was independent of irradiance except at 10 mm bicarbonate and 100% O2, where inhibition decreased with increasing irradiance up to the point of light saturation of photosynthesis. Concomitant with increasing O2 inhibition of photosynthesis was an increased incorporation of carbon into glycine and serine, intermediates of the photorespiratory pathway, and a decreased incorporation into starch. The effects of CO2 and O2 concentration and temperature on soybean cell photosynthesis and photorespiration provide further evidence that these processes are regulated by the kinetic properties of ribulose-1,5-diphosphate carboxylase with respect to CO2 and O2. PMID:16660238

  15. Modulating oscillatory brain activity correlates of behavioral inhibition using transcranial direct current stimulation.

    PubMed

    Jacobson, Liron; Ezra, Adi; Berger, Uri; Lavidor, Michal

    2012-05-01

    Studies have mainly documented behavioral changes induced by transcranial direct current stimulation (tDCS), but recently cortical modulations of tDCS have also been investigated. Our previous work revealed behavioral inhibition modulation by anodal tDCS over the right inferior frontal gyrus (rIFG); however, the electrophysiological correlates underlying this stimulation montage have yet to be established. The current work aimed to evaluate the distribution of neuronal oscillations changes following anodal tDCS over rIFG coupled with cathodal tDCS over left orbitofrontal cortex (lOFC) using spectral power analysis. Healthy subjects underwent sham and real tDCS (15 min, 1.5 mA, anodal rIFG; cathodal lOFC) stimulation conditions in a single-blind, placebo-controlled cross-over trial. Following tDCS session, resting EEG recordings were collected during 15 min. Analysis showed a significant and selective diminution of the power of theta band. The theta diminution was observed in the rIFG area (represented the anode electrode), and was not found in the lOFC area (represented the cathode electrode). A significant effect was observed only in the theta but not in other bands. These results are the first demonstration of modulating oscillatory activity as measured by EEG with tDCS over rIFG in general, and documenting theta band reduction with this montage in particular. Our results may explain the improvement in behavioral inhibition reported in our previous work, and although this study was conducted with healthy subjects, the findings suggest that tDCS may also modulate electrophysiological changes among ADHD patients, where decreasing theta activity is the target of neuro-feedback methods aimed to improve cognitive control. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Muscarinic inhibition of [3H]-noradrenaline release on rabbit iris in vitro: effects of stimulation conditions on intrinsic activity of methacholine and pilocarpine.

    PubMed Central

    Bognar, I. T.; Pallas, S.; Fuder, H.; Muscholl, E.

    1988-01-01

    1. Rabbit isolated irides were loaded with [3H]-noradrenaline and superfused with Tyrode solution. The inhibition by the muscarinic agonists (+/-)-methacholine and pilocarpine of the [3H]-noradrenaline overflow into the superfusate evoked by field stimulation (pulses of 1 ms duration, 75 mA) was measured as an index of activation of presynaptic muscarinic receptors. 2. The fractional rate of release per pulse during the first stimulation period (S1) was low with 360 pulses at 3 Hz, intermediate with 360 pulses at 10 Hz and high with 1200 pulses at 10 Hz. Upon repetitive stimulation (7 periods at 20 min intervals), the fractional rates of release per pulse during S7 no longer differed, suggesting a 'long-term' regulation of [3H]-noradrenaline release depending on the stimulation conditions. 3. The evoked [3H]-noradrenaline overflow was depressed by (+/-)-methacholine in a concentration-dependent manner. The EC50 ranged from 0.29 to 0.42 microM. Methacholine nearly abolished the transmitter release evoked at 3 Hz but reduced that induced at 10 Hz by only 50%. Under the latter condition the methacholine concentration-inhibition curve was bell-shaped and no muscarinic inhibition was observed in the presence of methacholine 30 microM. After washout of methacholine the evoked [3H]-noradrenaline release was temporarily enhanced. 4. Atropine 0.1 microM enhanced the [3H]-noradrenaline overflow (evoked by stimulation with 360 or 1200 pulses at 10 Hz), probably antagonizing a presynaptic inhibition by endogenous acetylcholine. The inhibition by methacholine was competitively antagonized by atropine 0.1 microM (apparent -log KB = 8.5-9.0). 5. Depending on the concentration, pilocarpine reduced the [3H]-noradrenaline overflow evoked by 360 pulses at 3 Hz up to 63%. However, at 10 Hz stimulation frequency the compound was inactive as an agonist but competitively antagonized the presynaptic inhibition induced by methacholine. The KB under the latter condition (0.95 microM) was

  17. Fatty Acid-binding Proteins Interact with Comparative Gene Identification-58 Linking Lipolysis with Lipid Ligand Shuttling*

    PubMed Central

    Hofer, Peter; Boeszoermenyi, Andras; Jaeger, Doris; Feiler, Ursula; Arthanari, Haribabu; Mayer, Nicole; Zehender, Fabian; Rechberger, Gerald; Oberer, Monika; Zimmermann, Robert; Lass, Achim; Haemmerle, Guenter; Breinbauer, Rolf; Zechner, Rudolf; Preiss-Landl, Karina

    2015-01-01

    The coordinated breakdown of intracellular triglyceride (TG) stores requires the exquisitely regulated interaction of lipolytic enzymes with regulatory, accessory, and scaffolding proteins. Together they form a dynamic multiprotein network designated as the “lipolysome.” Adipose triglyceride lipase (Atgl) catalyzes the initiating step of TG hydrolysis and requires comparative gene identification-58 (Cgi-58) as a potent activator of enzyme activity. Here, we identify adipocyte-type fatty acid-binding protein (A-Fabp) and other members of the fatty acid-binding protein (Fabp) family as interaction partners of Cgi-58. Co-immunoprecipitation, microscale thermophoresis, and solid phase assays proved direct protein/protein interaction between A-Fabp and Cgi-58. Using nuclear magnetic resonance titration experiments and site-directed mutagenesis, we located a potential contact region on A-Fabp. In functional terms, A-Fabp stimulates Atgl-catalyzed TG hydrolysis in a Cgi-58-dependent manner. Additionally, transcriptional transactivation assays with a luciferase reporter system revealed that Fabps enhance the ability of Atgl/Cgi-58-mediated lipolysis to induce the activity of peroxisome proliferator-activated receptors. Our studies identify Fabps as crucial structural and functional components of the lipolysome. PMID:25953897

  18. Polyisoprenoid epoxides stimulate the biosynthesis of coenzyme Q and inhibit cholesterol synthesis.

    PubMed

    Bentinger, Magnus; Tekle, Michael; Brismar, Kerstin; Chojnacki, Tadeusz; Swiezewska, Ewa; Dallner, Gustav

    2008-05-23

    In our search for compounds that up-regulate the biosynthesis of coenzyme Q (CoQ), we discovered that irradiation of CoQ with ultraviolet light results in the formation of a number of compounds that influence the synthesis of mevalonate pathway lipids by HepG2 cells. Among the compounds that potently stimulated CoQ synthesis while inhibiting cholesterol synthesis, derivatives of CoQ containing 1-4 epoxide moieties in their polyisoprenoid side chains were identified. Subsequently, chemical epoxidation of all-trans-polyprenols of different lengths revealed that the shorter farnesol and geranylgeraniol derivatives were without effect, whereas the longer derivatives of solanesol enhanced CoQ and markedly reduced cholesterol biosynthesis. In contrast, none of the modified trans-trans-poly-cis-polyprenols exerted noticeable effects. Tocotrienol epoxides were especially potent in our system; those with one epoxide moiety in the side-chain generally up-regulated CoQ biosynthesis by 200-300%, whereas those with two such moieties also decreased cholesterol synthesis by 50-90%. Prolonged treatment of HepG2 cells with tocotrienol epoxides for 26 days elevated their content of CoQ by 30%. In addition, the levels of mRNA encoding enzymes involved in CoQ biosynthesis were also elevated by the tocotrienol epoxides. The site of inhibition of cholesterol synthesis was shown to be oxidosqualene cyclase. In conclusion, epoxide derivatives of certain all-trans-polyisoprenoids cause pronounced stimulation of CoQ synthesis and, in some cases, simultaneous reduction of cholesterol biosynthesis by HepG2 cells.

  19. Increased Response to β2-Adrenoreceptor Stimulation Augments Inhibition of IKr in Heart Failure Ventricular Myocytes

    PubMed Central

    Wang, Hegui; Chen, Yanhong; Zhu, Hongjun; Wang, Sen; Zhang, Xiwen; Xu, Dongjie; Cao, Kejiang; Zou, Jiangang

    2012-01-01

    Background Increasing evidence indicates that the rapid component of delayed rectifier potassium current (IKr) is modulated by α- and β-adrenergic stimulation. However, the role and mechanism regulating IKr through β2-adrenoreceptor (β-AR) stimulation in heart failure (HF) are unclear. Methodology/Principal Findings In the present study, we investigated the effects of fenoterol, a highly selective β2-AR agonist, on IKr in left ventricular myocytes obtained from control and guinea pigs with HF induced by descending aortic banding. IKr was measured by using whole cell patch clamp technique. In control myocytes, superfusion of fenoterol (10 µM) caused a 17% decrease in IKr. In HF myocytes, the same concentration of fenoterol produced a significantly greater decrease (33%) in IKr. These effects were not modified by the incubation of myocytes with CGP-20712A, a β1-AR antagonist, but were abolished by pretreatment of myocytes with ICI-118551, a β2-AR antagonist. An inhibitory cAMP analog, Rp-cAMPS and PKA inhibitor significantly attenuated fenoterol-induced inhibition of IKr in HF myocytes. Moreover, fenoterol markedly prolonged action potential durations at 90% (APD90) repolarization in HF ventricular myocytes. Conclusions The results indicate that inhibition of IKr induced by β2-AR stimulation is increased in HF. The inhibitory effect is likely to be mediated through a cAMP/PKA pathway in HF ventricular myocytes. PMID:23029432

  20. Nitazoxanide stimulates autophagy and inhibits mTORC1 signaling and intracellular proliferation of Mycobacterium tuberculosis.

    PubMed

    Lam, Karen K Y; Zheng, Xingji; Forestieri, Roberto; Balgi, Aruna D; Nodwell, Matt; Vollett, Sarah; Anderson, Hilary J; Andersen, Raymond J; Av-Gay, Yossef; Roberge, Michel

    2012-01-01

    Tuberculosis, caused by Mycobacterium tuberculosis infection, is a major cause of morbidity and mortality in the world today. M. tuberculosis hijacks the phagosome-lysosome trafficking pathway to escape clearance from infected macrophages. There is increasing evidence that manipulation of autophagy, a regulated catabolic trafficking pathway, can enhance killing of M. tuberculosis. Therefore, pharmacological agents that induce autophagy could be important in combating tuberculosis. We report that the antiprotozoal drug nitazoxanide and its active metabolite tizoxanide strongly stimulate autophagy and inhibit signaling by mTORC1, a major negative regulator of autophagy. Analysis of 16 nitazoxanide analogues reveals similar strict structural requirements for activity in autophagosome induction, EGFP-LC3 processing and mTORC1 inhibition. Nitazoxanide can inhibit M. tuberculosis proliferation in vitro. Here we show that it inhibits M. tuberculosis proliferation more potently in infected human THP-1 cells and peripheral monocytes. We identify the human quinone oxidoreductase NQO1 as a nitazoxanide target and propose, based on experiments with cells expressing NQO1 or not, that NQO1 inhibition is partly responsible for mTORC1 inhibition and enhanced autophagy. The dual action of nitazoxanide on both the bacterium and the host cell response to infection may lead to improved tuberculosis treatment.

  1. Enkephalin inhibition of angiotensin-stimulated release of oxytocin and vasopressin

    NASA Technical Reports Server (NTRS)

    Keil, L. C.; Chee, O.; Rosella-Dampman, L. M.; Emmert, S.; Summy-Long, J. Y.

    1984-01-01

    The effect of intracerebroventricular (ICV) pretreatment with 100 ng/5 microliter leucine(5)-enkephalin (LE) on the increase in plasma oxytocin (OT) and vasopressin (VP) caused by ICV injection of 10, 50, or 100 ng/5 microliter of angiotensin II (AII) is investigated experimentally in conscious adult male Sprague-Dawley rats; the effects of water-deprivation dehydration and lactation/suckling (in female rats) are also studied. An OT radioimmunoassay (RIA) with a sensitivity of 800 fg/ml (described in detail) and the VP RIA technique of Keil and Severs (1977) are employed. Administration of AII or dehydration for 48 or 72 h cause a significant increase in OT and VP without affecting the ratio, while lactation and suckling increase OT only. LE pretreatment inhibits significantly but does not suppress the AII-stimulated OT-VP response.

  2. Production and characterization of a tributyrin esterase from Lactobacillus plantarum suitable for cheese lipolysis.

    PubMed

    Esteban-Torres, M; Mancheño, J M; de las Rivas, B; Muñoz, R

    2014-11-01

    Lactobacillus plantarum is a lactic acid bacterium that can be found during cheese ripening. Lipolysis of milk triacylglycerols to free fatty acids during cheese ripening has fundamental consequences on cheese flavor. In the present study, the gene lp_1760, encoding a putative esterase or lipase, was cloned and expressed in Escherichia coli BL21 (DE3) and the overproduced Lp_1760 protein was biochemically characterized. Lp_1760 hydrolyzed p-nitrophenyl esters of fatty acids from C2 to C16, with a preference for p-nitrophenyl butyrate. On triglycerides, Lp_1760 showed higher activity on tributyrin than on triacetin. Although optimal conditions for activity were 45°C and pH 7, Lp_1760 retains activity under conditions commonly found during cheese making and ripening. The Lp_1760 showed more than 50% activity at 5°C and exhibited thermal stability at high temperatures. Enzymatic activity was strongly inhibited by sodium dodecyl sulfate and phenylmethylsulfonyl fluoride. The Lp_1760 tributyrin esterase showed high activity in the presence of NaCl, lactic acid, and calcium chloride. The results suggest that Lp_1760 might be a useful tributyrin esterase to be used in cheese manufacturing. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Inhibition of nitric oxide in LPS-stimulated macrophages of young and senescent mice by δ-tocotrienol and quercetin

    PubMed Central

    2011-01-01

    Background Changes in immune function believed to contribute to a variety of age-related diseases have been associated with increased production of nitric oxide (NO). We have recently reported that proteasome inhibitors (dexamethasone, mevinolin, quercetin, δ-tocotrienol, and riboflavin) can inhibit lipopolysaccharide (LPS)-induced NO production in vitro by RAW 264.7 cells and by thioglycolate-elicited peritoneal macrophages derived from four strains of mice (C57BL/6, BALB/c, LMP7/MECL-1-/- and PPAR-α-/- knockout mice). The present study was carried out in order to further explore the potential effects of diet supplementation with naturally-occurring inhibitors (δ-tocotrienol and quercetin) on LPS-stimulated production of NO, TNF-α, and other pro-inflammatory cytokines involved in the ageing process. Young (4-week-old) and senescent mice (42-week old) were fed control diet with or without quercetin (100 ppm), δ-tocotrienol (100 ppm), or dexamethasone (10 ppm; included as positive control for suppression of inflammation) for 4 weeks. At the end of feeding period, thioglycolate-elicited peritoneal macrophages were collected, stimulated with LPS, LPS plus interferon-β (IFN-β), or LPS plus interferon-γ (IFN-γ), and inflammatory responses assessed as measured by production of NO and TNF-α, mRNA reduction for TNF-α, and iNOS genes, and microarray analysis. Results Thioglycolate-elicited peritoneal macrophages prepared after four weeks of feeding, and then challenged with LPS (10 ng or 100 ng) resulted in increases of 55% and 73%, respectively in the production of NO of 46-week-old compared to 8-week-old mice fed control diet alone (respective control groups), without affecting the secretion of TNF-α among these two groups. However, macrophages obtained after feeding with quercetin, δ-tocotrienol, and dexamethasone significantly inhibited (30% to 60%; P < 0.02) the LPS-stimulated NO production, compared to respective control groups. There was a 2-fold

  4. Influence of interfacial and bulk properties of cellulose ethers on lipolysis of oil-in-water emulsions.

    PubMed

    Torcello-Gómez, Amelia; Foster, Timothy J

    2016-06-25

    Cellulose ethers are usually used as secondary emulsifiers. Different types of commercial hydroxypropylmethylcellulose (HPMC) have been used here as the main emulsifier of oil-in-water emulsions to probe their impact on the lipid digestibility under simulated intestinal conditions. The droplet size distribution and ζ-potential of the emulsions subjected to in-vitro lipolysis have been compared with that of control samples (non-digested). The lipolysis has been quantified over time by means of the pH-stat method. The displacement of HPMC from the oil-water interface by bile salts has been assessed by interfacial tension technique. Results show that HPMC delays the lipid digestion of emulsions regardless of the Mw and methoxyl content. The destabilisation of emulsions under intestinal conditions as well as the resistance of HPMC to be displaced from the emulsion interface by bile salts may contribute to this feature. This provides new insights into the mechanisms whereby dietary fibre reduces fat absorption. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Cortical Inhibition in Attention Deficit Hyperactivity Disorder: New Insights from the Electroencephalographic Response to Transcranial Magnetic Stimulation

    ERIC Educational Resources Information Center

    Bruckmann, Sarah; Hauk, Daniela; Roessner, Veit; Resch, Franz; Freitag, Christine M.; Kammer, Thomas; Ziemann, Ulf; Rothenberger, Aribert; Weisbrod, Matthias; Bender, Stephan

    2012-01-01

    Attention deficit hyperactivity disorder is one of the most frequent neuropsychiatric disorders in childhood. Transcranial magnetic stimulation studies based on muscle responses (motor-evoked potentials) suggested that reduced motor inhibition contributes to hyperactivity, a core symptom of the disease. Here we employed the N100 component of the…

  6. Lipolysis and lipid oxidation in fermented sausages depending on different processing conditions and different antioxidants.

    PubMed

    Zanardi, Emanuela; Ghidini, Sergio; Battaglia, Alessandra; Chizzolini, Roberto

    2004-02-01

    Lipolysis and lipid oxidation in Mediterranean and North Europe type sausages were studied in relation to raw material, processing conditions and additives. In particular the effect of ascorbic acid, nitrites and spices was evaluated. Lipolysis was measured by the determination of total and free fatty acids of fresh minces and matured products and lipid oxidation was evaluated by thiobarbituric acid reactive substances and cholesterol oxidation products. The increase of free fatty acids during maturation appears to be independent from processing conditions and the differences in polyunsaturated fatty acids increment found among the formulations appear to be due to inherent variations of raw materials. The presence of ascorbic acid and/or nitrite seems important for cholesterol protection and, as a consequence, for the safety of fermented meat products while spices at doses up to 0.1% do not seem to have a remarkable effect. The effect on fatty acid oxidation of the same additives and of the different processing technologies is not significantly different and the variations linked to raw material may play the greatest role.

  7. Apolipoprotein CIII overexpression exacerbates diet-induced obesity due to adipose tissue higher exogenous lipid uptake and retention and lower lipolysis rates.

    PubMed

    Raposo, Helena F; Paiva, Adriene A; Kato, Larissa S; de Oliveira, Helena C F

    2015-01-01

    Hypertriglyceridemia is a common type of dyslipidemia found in obesity. However, it is not established whether primary hyperlipidemia can predispose to obesity. Evidences have suggested that proteins primarily related to plasma lipoprotein transport, such as apolipoprotein (apo) CIII and E, may significantly affect the process of body fat accumulation. We have previously observed an increased adiposity in response to a high fat diet (HFD) in mice overexpressing apoCIII. Here, we examined the potential mechanisms involved in this exacerbated response of apoCIII mice to the HFD. We measured body energy balance, tissue capacity to store exogenous lipids, lipogenesis and lipolysis rates in non-transgenic and apoCIII overexpressing mice fed a HFD during two months. Food intake, fat excretion and whole body CO2 production were similar in both groups. However, the adipose tissue mass (45 %) and leptin plasma levels (2-fold) were significantly greater in apoCIII mice. Lipogenesis rates were similar, while exogenous lipid retention was increased in perigonadal (2-fold) and brown adipose tissues (40 %) of apoCIII mice. In addition, adipocyte basal lipolysis (55 %) and in vivo lipolysis index (30 %) were significantly decreased in apoCIII mice. A fat tolerance test evidenced delayed plasma triglyceride clearance and greater transient availability of non-esterified fatty acids (NEFA) during the post-prandial state in the apoCIII mice plasma. Thus, apoCIII overexpression resulted in increased NEFA availability to adipose uptake and decreased adipocyte lipolysis, favoring lipid enlargement of adipose depots. We propose that plasma apoCIII levels represent a new risk factor for diet-induced obesity.

  8. Increased adipose tissue lipolysis after a 2-week high-fat diet in sedentary overweight/obese men.

    PubMed

    Howe, Harold R; Heidal, Kimberly; Choi, Myung Dong; Kraus, Ray M; Boyle, Kristen; Hickner, Robert C

    2011-07-01

    The purpose of this study was to determine if a high-fat diet would result in a higher lipolytic rate in subcutaneous adipose tissue than a lower-fat diet in sedentary nonlean men. Six participants (healthy males; 18-40 years old; body mass index, 25-37 kg/m(2)) underwent 2 weeks on a high-fat or well-balanced diet of similar energy content (approximately 6695 kJ) in randomized order with a 10-day washout period between diets. Subcutaneous abdominal adipose tissue lipolysis was determined over the course of a day using microdialysis after both 2-week diet sessions. Average interstitial glycerol concentrations (index of lipolysis) as determined using microdialysis were higher after the high-fat diet (210.8 ± 27.9 μmol/L) than after a well-balanced diet (175.6 ± 23.3 μmol/L; P = .026). There was no difference in adipose tissue microvascular blood flow as determined using the microdialysis ethanol technique. These results demonstrate that healthy nonlean men who diet on the high-fat plan have a higher lipolytic rate in subcutaneous abdominal adipose tissue than when they diet on a well-balanced diet plan. This higher rate of lipolysis may result in a higher rate of fat mass loss on the high-fat diet; however, it remains to be determined if this higher lipolytic rate in men on the high-fat diet results in a more rapid net loss of triglyceride from the abdominal adipose depots, or if the higher lipolytic rate is counteracted by an increased rate of lipid storage. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Increased adipose tissue lipolysis after a two-week high-fat diet in sedentary overweight/obese men

    PubMed Central

    Howe, Harold R; Heidal, Kimberly; Choi, Myung Dong; Kraus, Ray M.; Boyle, Kristen; Hickner, Robert C.

    2013-01-01

    Background/Objectives The purpose of this study was to determine if a high fat diet would result in a higher lipolytic rate in subcutaneous adipose tissue than a lower fat diet in sedentary non-lean men. Subjects/Methods Six participants (healthy males: 18-40 yrs old: body mass index 25-37 kg/m2) underwent two weeks on a high-fat or well-balanced diet of similar caloric content (approx. 1600 kcal) in randomized order with a ten-day washout period between diets. Subcutaneous abdominal adipose tissue lipolysis was determined over the course of a day using microdialysis after both two-week diet sessions. Results Average interstitial glycerol concentrations (index of lipolysis) as determined using microdialysis were higher following the high-fat diet (210.8 ±27.9 μM) than following a well-balanced diet (175.6 ± 23.3 μM; P = 0.026). There was no difference in adipose tissue microvascular blood flow as determined using the microdialysis ethanol technique. Conclusions These results demonstrate that healthy non-lean men who diet on the high-fat plan have a higher lipolytic rate in subcutaneous abdominal adipose tissue than when they diet on a well-balanced diet plan. This higher rate of lipolysis may result in a higher rate of fat mass loss on the high-fat diet; however, it remains to be determined if this higher lipolytic rate in men on the high-fat diet results in a more rapid net loss of triglyceride from the abdominal adipose depots, or if the higher lipolytic rate is counteracted by an increased rate of lipid storage. PMID:21040937

  10. Ethanol and Other Short-Chain Alcohols Inhibit NLRP3 Inflammasome Activation through Protein Tyrosine Phosphatase Stimulation

    PubMed Central

    Hoyt, Laura R.; Ather, Jennifer L.; Randall, Matthew J.; DePuccio, Daniel P.; Landry, Christopher C.; Wewers, Mark D.; Gavrilin, Mikhail A.; Poynter, Matthew E.

    2016-01-01

    Immunosuppression is a major complication of alcoholism that contributes to increased rates of opportunistic infections and sepsis in alcoholics. The NLRP3 inflammasome, a multi-protein intracellular pattern recognition receptor complex that facilitates the cleavage and secretion of the pro-inflammatory cytokines IL-1β and IL-18, can be inhibited by ethanol and we sought to better understand the mechanism through which this occurs and whether chemically similar molecules exert comparable effects. We show that ethanol can specifically inhibit activation of the NLRP3 inflammasome, resulting in attenuated IL-1β and caspase-1 cleavage and secretion, as well as diminished ASC speck formation, without affecting potassium efflux, in a mouse macrophage cell line (J774), mouse bone marrow derived dendritic cells, mouse neutrophils, and human PBMCs. The inhibitory effects on the Nlrp3 inflammasome were independent of GABAA receptor activation or NMDA receptor inhibition, but was associated with decreased oxidant production. Ethanol treatment markedly decreased cellular tyrosine phosphorylation, while administration of the tyrosine phosphatase inhibitor sodium orthovanadate prior to ethanol restored tyrosine phosphorylation and IL-1β secretion subsequent to ATP stimulation. Furthermore, sodium orthovanadate-induced phosphorylation of ASC Y144, necessary and sufficient for Nlrp3 inflammasome activation, and secretion of phosphorylated ASC, were inhibited by ethanol. Finally, multiple alcohol-containing organic compounds exerted inhibitory effects on the Nlrp3 inflammasome, whereas 2-methylbutane (isopentane), the analogous alkane of the potent inhibitor isoamyl alcohol (isopentanol), did not. Our results demonstrate that ethanol antagonizes the NLRP3 inflammasome at an apical event in its activation through the stimulation of protein tyrosine phosphatases, an effect shared by other short-chain alcohols. PMID:27421477

  11. Mangiferin ameliorates insulin resistance by inhibiting inflammation and regulatiing adipokine expression in adipocytes under hypoxic condition.

    PubMed

    Yang, Chao-Qiang; Xu, Jing-Hua; Yan, Dan-Dan; Liu, Bao-Lin; Liu, Kang; Huang, Fang

    2017-09-01

    Adipose tissue hypoxia has been recognized as the initiation of insulin resistance syndromes. The aim of the present study was to investigate the effects of mangiferin on the insulin signaling pathway and explore whether mangiferin could ameliorate insulin resistance caused by hypoxia in adipose tissue. Differentiated 3T3-L1 adipocytes were incubated under normal and hypoxic conditions, respectively. Protein expressions were analyzed by Western blotting. Inflammatory cytokines and HIF-1-dependent genes were tested by ELISA and q-PCR, respectively. The glucose uptake was detected by fluorescence microscopy. HIF-1α was abundantly expressed during 8 h of hypoxic incubation. Inflammatory reaction was activated by up-regulated NF-κB phosphorylation and released cytokines like IL-6 and TNF-α. Glucose uptake was inhibited and insulin signaling pathway was damaged as well. Mangiferin substantially inhibited the expression of HIF-1α. Lactate acid and lipolysis, products released by glycometabolism and lipolysis, were also inhibited. The expression of inflammatory cytokines was significantly reduced and the damaged insulin signaling pathway was restored to proper functional level. The glucose uptake of hypoxic adipocytes was promoted and the dysfunction of adipocytes was relieved. These results showed that mangiferin could not only improve the damaged insulin signaling pathway in hypoxic adipocytes, but also ameliorate inflammatory reaction and insulin resistance caused by hypoxia. Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  12. Increased response to β₂-adrenoreceptor stimulation augments inhibition of IKr in heart failure ventricular myocytes.

    PubMed

    Wang, Hegui; Chen, Yanhong; Zhu, Hongjun; Wang, Sen; Zhang, Xiwen; Xu, Dongjie; Cao, Kejiang; Zou, Jiangang

    2012-01-01

    Increasing evidence indicates that the rapid component of delayed rectifier potassium current (I(Kr)) is modulated by α- and β-adrenergic stimulation. However, the role and mechanism regulating I(Kr) through β(2)-adrenoreceptor (β-AR) stimulation in heart failure (HF) are unclear. In the present study, we investigated the effects of fenoterol, a highly selective β(2)-AR agonist, on I(Kr) in left ventricular myocytes obtained from control and guinea pigs with HF induced by descending aortic banding. I(Kr) was measured by using whole cell patch clamp technique. In control myocytes, superfusion of fenoterol (10 µM) caused a 17% decrease in I(Kr). In HF myocytes, the same concentration of fenoterol produced a significantly greater decrease (33%) in I(Kr). These effects were not modified by the incubation of myocytes with CGP-20712A, a β(1)-AR antagonist, but were abolished by pretreatment of myocytes with ICI-118551, a β(2)-AR antagonist. An inhibitory cAMP analog, Rp-cAMPS and PKA inhibitor significantly attenuated fenoterol-induced inhibition of I(Kr) in HF myocytes. Moreover, fenoterol markedly prolonged action potential durations at 90% (APD(90)) repolarization in HF ventricular myocytes. The results indicate that inhibition of I(Kr) induced by β(2)-AR stimulation is increased in HF. The inhibitory effect is likely to be mediated through a cAMP/PKA pathway in HF ventricular myocytes.

  13. CD95 co-stimulation blocks activation of naive T cells by inhibiting T cell receptor signaling

    PubMed Central

    Lindquist, Jonathan A.; Arhel, Nathalie; Felder, Edward; Karl, Sabine; Haas, Tobias L.; Fulda, Simone; Walczak, Henning; Kirchhoff, Frank; Debatin, Klaus-Michael

    2009-01-01

    CD95 is a multifunctional receptor that induces cell death or proliferation depending on the signal, cell type, and cellular context. Here, we describe a thus far unknown function of CD95 as a silencer of T cell activation. Naive human T cells triggered by antigen-presenting cells expressing a membrane-bound form of CD95 ligand (CD95L) or stimulated by anti-CD3 and -CD28 antibodies in the presence of recombinant CD95L had reduced activation and proliferation, whereas preactivated, CD95-sensitive T cells underwent apoptosis. Triggering of CD95 during T cell priming interfered with proximal T cell receptor signaling by inhibiting the recruitment of ζ-chain–associated protein of 70 kD, phospholipase-γ, and protein kinase C-θ into lipid rafts, thereby preventing their mutual tyrosine protein phosphorylation. Subsequently, Ca2+ mobilization and nuclear translocation of transcription factors NFAT, AP1, and NF-κB were strongly reduced, leading to impaired cytokine secretion. CD95-mediated inhibition of proliferation in naive T cells could not be reverted by the addition of exogenous interleukin-2 and T cells primed by CD95 co-stimulation remained partially unresponsive upon secondary T cell stimulation. HIV infection induced CD95L expression in primary human antigeen-presenting cells, and thereby suppressed T cell activation, suggesting that CD95/CD95L-mediated silencing of T cell activation represents a novel mechanism of immune evasion. PMID:19487421

  14. Inhibition of 2,4-dichlorophenoxyacetic acid-stimulated elongation of pea stem segments by a xyloglucan oligosaccharide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    York, W.S.; Darvill, A.G.; Albersheim, P.

    1984-06-01

    Xyloglucan, isolated from the soluble extracellular polysaccharides of suspension-cultured sycamore (Acer pseudoplatanus) cells, was digested with an endo-..beta..-1,4-glucanase purified from the culture fluid of Trichoderma viride. A nonasaccharide-rich Bio-Gel P-2 fraction of this digest inhibited 2,4-dichlorophenoxyacetic-acid-stimulated elongation of etiolated pea stem segments. The inhibitory activity of this oligosaccharide fraction exhibited a well-define concentraction optimum between 10/sup -2/ and 10/sup -1/ micrograms per milliliter. Another fraction of the same xyloglucan digest, rich in a structurally related heptasaccharide, did not, at similar concentrations, significantly inhibit the elongation. 11 references, 3 figures.

  15. Passive heat loading links lipolysis and regulation of fibroblast growth factor-21 in humans.

    PubMed

    Lee, Jeong-Beom; Kim, Tae-Wook

    2014-10-01

    There is relativley little information on the serum biomarkers of heat stress. Therefore, the goal of this study was to verify the effect of passive heat loading (PHL) on the expression of fibroblast growth factor-21 (FGF21) and free fatty acids (FFAs). Four PHL protocols based on intensity (39 °C vs. 43 °C, leg immersion, 30 min) and type (leg vs. half immersion, 42 °C, 30 min) were used. Each protocol was applied on a 2 day cycle to 12 healthy adult males (age, 22.4 ± 2.9 years; height, 174.1 ± 4.6 cm; weight, 71.3 ± 5.6 kg; body mass index, 23.1 ± 3.0). The subjects were categorized into two groups according to the study design (randomized, with a parallel trial). Body temperature, FGF21 and FFAs were determined prior to PH L, immediately and 60 min after PHL. Body temperature was significant higher (43 °C) than the 39 °C measured under identical PHL type (leg immersion). PHL was effective for the expression of FGF21 and for lipolysis. The quantitative levels of FGF21 and FFA increased with increasing temperature (39 °C<42 °C<43 °C). A significant difference in the quantitative levels of FGF21 and FFAs was also evident based on the type of PHL (leglipolysis. Therefore, PHL may be expected to help in the reduction of body fat. Additionally, when the identical type (leg immersion) of PHL is applied, a loading temperature of 43 °C is more effective for expressing FGF21 and for lipolysis than temperatures of 39 °C and 42 °C, and half immersion is more effective than leg immersion at 42 °C. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A Preliminary Transcranial Magnetic Stimulation Study of Cortical Inhibition and Excitability in High-Functioning Autism and Asperger Disorder

    ERIC Educational Resources Information Center

    Enticott, Peter G.; Rinehart, Nicole J.; Tonge, Bruce J.; Bradshaw, John L.; Fitzgerald, Paul B.

    2010-01-01

    Aim: Controversy surrounds the distinction between high-functioning autism (HFA) and Asperger disorder, but motor abnormalities are associated features of both conditions. This study examined motor cortical inhibition and excitability in HFA and Asperger disorder using transcranial magnetic stimulation (TMS). Method: Participants were diagnosed by…

  17. Sex-specific inhibition and stimulation of worker-reproductive transition in a termite.

    PubMed

    Sun, Qian; Haynes, Kenneth F; Hampton, Jordan D; Zhou, Xuguo

    2017-09-06

    In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.

  18. Sex-specific inhibition and stimulation of worker-reproductive transition in a termite

    NASA Astrophysics Data System (ADS)

    Sun, Qian; Haynes, Kenneth F.; Hampton, Jordan D.; Zhou, Xuguo

    2017-10-01

    In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.

  19. Do imipramine and dihydroergosine possess two components - one stimulating 5-HT sub 1 and the other inhibiting 5-HT sub 2 receptors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pericic, D.; Mueck-Seler, D.

    1990-01-01

    The mechanisms by which imipramine and dihydroergosine stimulate the 5-HT syndrome in rats and inhibit the head-twitch response in rats and mice were studied. Imipramine- and dihydroergosine-included stimulation of the 5-HT syndrome was inhibited stereoselectively by propranolol, a high affinity ligand for 5-HT{sub 1} receptor sites, but not by ritanserin, a specific 5-HT{sub 2} receptor antagonist. (-) -Propranolol potentiated the inhibitory effect of imipramine, but not of dihydroergosine on the head-twitch response, while ritanserin was without effect. As expected, 8-OH-DPAT, a selective 5-HT{sub 1A} receptor agonist, stimulated, and 5-HT{sub 1B} agonists CGS 12066B and 1-(trifluoromethylphenyl) piperazine (TFMPP) failed to stimulatemore » the 5-HT syndrome induced in rats by pargyline and 5-HTP administration. A higher dose of ritanserin inhibited the syndrome. While 8-OH-DPAT alone produced all behavioral components of the 5-HT syndrome, dihydroergosine or imipramine alone even at very high doses never produced tremor or a more intensive forepaw padding as seen when these drugs were given in combination with pargyline and 5-HTP. A single administration of (-)-propranolol also inhibited the head-twitch response. This effect lasted in mice longer that after ritanserin administration. In in vitro experiments dihydroergosine expressed approximately twenty-fold higher affinity for {sup 3}H-ketanserin binding sites than imipramine.« less

  20. Inhibition of motor cortex excitability with 15Hz transcranial alternating current stimulation (tACS).

    PubMed

    Zaghi, Soroush; de Freitas Rezende, Larissa; de Oliveira, Laís Machado; El-Nazer, Rasheda; Menning, Sanne; Tadini, Laura; Fregni, Felipe

    2010-08-02

    There remains a lack of solid evidence showing whether transcranial stimulation with weak alternating current (transcranial alternating current stimulation, tACS) can in fact induce significant neurophysiological effects. Previously, a study in which tACS was applied for 2 and 5min with current density=0.16-0.25A/m(2) was unable to show robust effects on cortical excitability. Here we applied tACS at a significantly higher current density (0.80A/m(2)) for a considerably longer duration (20min) and were indeed able to demonstrate measurable changes to cortical excitability. Our results show that active 15Hz tACS of the motor cortex (electrodes placed at C3 and C4) significantly diminished the amplitude of motor evoked potentials and decreased intracortical facilitation (ICF) as compared to baseline and sham stimulation. In addition, we show that our method of sham tACS is a reliable control condition. These results support the notion that AC stimulation with weak currents can induce significant changes in brain excitability; in this case, 15Hz tACS led to a pattern of inhibition of cortical excitability. We propose that tACS may have a dampening effect on cortical networks and perhaps interfere with the temporal and spatial summation of weak subthreshold electric potentials. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Inhibition of the k-stimulated ATPase of the plasmalemma of pinto bean leaves by ozone.

    PubMed

    Dominy, P J; Heath, R L

    1985-01-01

    Three varieties of Phaseolus vulgaris which differ in their sensitivity to ozone were examined for changes in some physiological and structural plasma membrane characteristics. Plasma membrane vesicles were prepared from control and ozone-treated (0.2 to 0.5 microliters per liter ozone for 5 hours) leaf tissue, and the (K(+) + Mg(2+))-ATPase activity determined and compared. No major changes were observed in the resistant varieties. The sensitive variety showed a severe inhibition of ATPase activity which was largely due to a decrease in the K(+)-stimulated component. This inhibition was completely reversed by the addition of sulfhydryl compounds.Ozone-induced plasma membrane permeability changes may be effected by damage to membrane proteins, perhaps by oxidation of amino acid sulfhydryl groups to disulfide and sulfenic moieties.

  2. Regulation of fat specific protein 27 by isoproterenol and TNF-alpha to control lipolysis in murine adipocytes

    USDA-ARS?s Scientific Manuscript database

    The lipid droplet-associated fat specific protein 27 (FSP27) suppresses lipolysis and thereby enhances triglyceride accumulation in adipocytes. We and others have recently found FSP27 to be a remarkably short-lived protein (half-life, 15 min) due to its rapid ubiquitination and proteasomal degradati...

  3. Fish in Vitro Digestion: Influence of Fish Salting on the Extent of Lipolysis, Oxidation, and Other Reactions.

    PubMed

    Nieva-Echevarría, Bárbara; Goicoechea, Encarnación; Manzanos, María J; Guillén, María D

    2017-02-01

    A study of the various chemical reactions which take place during fish in vitro digestion and the potential effect of fish salting on their extent is addressed for the first time. Farmed European sea bass fillets, raw, brine-salted or dry-salted, were digested using a gastrointestinal in vitro model. Fish lipid extracts before and after digestion were analyzed by 1 H NMR, and the headspace composition of the digestates was investigated by SPME-GC/MS. During digestion, not only lipolysis, but also fish lipid oxidation took place. This latter was evidenced by the generation of conjugated dienes supported on chains having also hydroperoxy- and hydroxy-groups (primary oxidation compounds), by the increase of volatile secondary oxidation products, and by the decrease of the antioxidant 2,6-di-tert-butyl-hydroxytoluene (BHT). Likewise, esterification and Maillard-type reactions also occurred. Salting, and especially dry-salting, enhanced all these reactions, except for lipolysis, during digestion.

  4. Impact of pasteurization of human milk on preterm newborn in vitro digestion: Gastrointestinal disintegration, lipolysis and proteolysis.

    PubMed

    de Oliveira, Samira C; Bourlieu, Claire; Ménard, Olivia; Bellanger, Amandine; Henry, Gwénaële; Rousseau, Florence; Dirson, Emelyne; Carrière, Frédéric; Dupont, Didier; Deglaire, Amélie

    2016-11-15

    Human milk feeding is an important recommendation for preterm newborns considering their vulnerability and digestive immaturity. Holder pasteurization (62.5°C, 30min) applied in milk banks modifies its biological quality and its microstructure. We investigated the impact of pasteurization of preterm human milk on its gastrointestinal kinetics of lipolysis, proteolysis and structural disintegration. An in vitro dynamic system was set up to simulate the gastrointestinal digestion of preterm newborns. A pool of preterm human milk was digested as raw or after Holder pasteurization. Pasteurization impacted the microstructure of undigested human milk, its gastrointestinal disintegration and tended to limit the intestinal lipolysis. Furthermore, the gastrointestinal bioaccessibility of some fatty acids was decreased by pasteurization, while the intestinal bioaccessibility of some amino acids was selectively modulated. The impact of pasteurization on the digestion of human milk may have nutritional relevance in vivo and potentially modulates preterm development and growth. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Antagonist interaction with the human 5-HT7 receptor mediates the rapid and potent inhibition of non-G-protein-stimulated adenylate cyclase activity: a novel GPCR effect

    PubMed Central

    Klein, MT; Teitler, M

    2011-01-01

    BACKGROUND AND PURPOSE The human 5-hydroxytryptamine7 (h5-HT7) receptor is Gs-coupled and stimulates the production of the intracellular signalling molecule cAMP. Previously, we reported a novel property of the h5-HT7 receptor: pseudo-irreversible antagonists irreversibly inhibit forskolin-stimulated (non-receptor-mediated) cAMP production. Herein, we sought to determine if competitive antagonists also affect forskolin-stimulated activity and if this effect is common among other Gs-coupled receptors. EXPERIMENTAL APPROACH Recombinant cell lines expressing h5-HT7 receptors or other receptors of interest were briefly exposed to antagonists; cAMP production was then stimulated by forskolin and quantified by an immunocompetitive assay. KEY RESULTS In human embryonic kidney 293 cells stably expressing h5-HT7 receptors, all competitive antagonists inhibited nearly 100% of forskolin-stimulated cAMP production. This effect was insensitive to pertussis toxin, that is, not Gi/o-mediated. Potency to inhibit forskolin-stimulated activity strongly correlated with h5-HT7 binding affinity (r2= 0.91), indicating that the antagonists acted through h5-HT7 receptors to inhibit forskolin. Potency and maximal effects of clozapine, a prototypical competitive h5-HT7 antagonist, were unaffected by varying forskolin concentration. Antagonist interaction with h5-HT6, human β1, β2, and β3 adrenoceptors did not inhibit forskolin's activity. CONCLUSIONS AND IMPLICATIONS The inhibition of adenylate cyclase, as measured by forskolin's activity, is an underlying property of antagonist interaction with h5-HT7 receptors; however, this is not a common property of other Gs-coupled receptors. This phenomenon may be involved in the roles played by h5-HT7 receptors in human physiology. Development of h5-HT7 antagonists that do not elicit this effect would aid in the elucidation of its mechanisms and shed light on its possible physiological relevance. PMID:21198551

  6. Apical ammonium inhibition of cAMP-stimulated secretion in T84 cells is bicarbonate dependent.

    PubMed

    Worrell, Roger T; Best, Alison; Crawford, Oscar R; Xu, Jie; Soleimani, Manoocher; Matthews, Jeffrey B

    2005-10-01

    Normal human colonic luminal (NH(4)(+)) concentration ([NH(4)(+)]) ranges from approximately 10 to 100 mM. However, the nature of the effects of NH(4)(+) on transport, as well as NH(4)(+) transport itself, in colonic epithelium is poorly understood. We elucidate here the effects of apical NH(4)(+) on cAMP-stimulated Cl(-) secretion in colonic T84 cells. In HEPES-buffered solutions, 10 mM apical NH(4)(+) had no significant effect on cAMP-stimulated current. In contrast, 10 mM apical NH(4)(+) reduced current within 5 min to 61 +/- 4% in the presence of 25 mM HCO(3)(-). Current inhibition was not simply due to an increase in extracellular K(+)-like cations, in that the current magnitude was 95 +/- 5% with 10 mM apical K(+) and 46 +/- 3% with 10 mM apical NH(4)(+) relative to that with 5 mM apical K(+). We previously demonstrated that inhibition of Cl(-) secretion by basolateral NH(4)(+) occurs in HCO(3)(-)-free conditions and exhibits anomalous mole fraction behavior. In contrast, apical NH(4)(+) inhibition of current in HCO(3)(-) buffer did not show anomalous mole fraction behavior and followed the absolute [NH(4)(+)] in K(+)-NH(4)(+) mixtures, where K(+) concentration + [NH(4)(+)] = 10 mM. The apical NH(4)(+) inhibitory effect was not prevented by 100 microM methazolamide, suggesting no role for apical carbonic anhydrase. However, apical NH(4)(+) inhibition of current was prevented by 10 min of pretreatment of the apical surface with 500 microM DIDS, 100 microM 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNDS), or 25 microM niflumic acid, suggesting a role for NH(4)(+) action through an apical anion exchanger. mRNA and protein for the apical anion exchangers SLC26A3 [downregulated in adenoma (DRA)] and SLC26A6 [putative anion transporter (PAT1)] were detected in T84 cells by RT-PCR and Northern and Western blots. DRA and PAT1 appear to associate with CFTR in the apical membrane. We conclude that the HCO(3)(-) dependence of apical NH(4)(+) inhibition of secretion is

  7. Ethanol and Other Short-Chain Alcohols Inhibit NLRP3 Inflammasome Activation through Protein Tyrosine Phosphatase Stimulation.

    PubMed

    Hoyt, Laura R; Ather, Jennifer L; Randall, Matthew J; DePuccio, Daniel P; Landry, Christopher C; Wewers, Mark D; Gavrilin, Mikhail A; Poynter, Matthew E

    2016-08-15

    Immunosuppression is a major complication of alcoholism that contributes to increased rates of opportunistic infections and sepsis in alcoholics. The NLRP3 inflammasome, a multiprotein intracellular pattern recognition receptor complex that facilitates the cleavage and secretion of the proinflammatory cytokines IL-1β and IL-18, can be inhibited by ethanol, and we sought to better understand the mechanism through which this occurs and whether chemically similar molecules exert comparable effects. We show that ethanol can specifically inhibit activation of the NLRP3 inflammasome, resulting in attenuated IL-1β and caspase-1 cleavage and secretion, as well as diminished apoptosis-associated speck-like protein containing a CARD (ASC) speck formation, without affecting potassium efflux, in a mouse macrophage cell line (J774), mouse bone marrow-derived dendritic cells, mouse neutrophils, and human PBMCs. The inhibitory effects on the Nlrp3 inflammasome were independent of γ-aminobutyric acid A receptor activation or N-methyl-d-asparate receptor inhibition but were associated with decreased oxidant production. Ethanol treatment markedly decreased cellular tyrosine phosphorylation, whereas administration of the tyrosine phosphatase inhibitor sodium orthovanadate prior to ethanol restored tyrosine phosphorylation and IL-1β secretion subsequent to ATP stimulation. Furthermore, sodium orthovanadate-induced phosphorylation of ASC Y144, necessary and sufficient for Nlrp3 inflammasome activation, and secretion of phosphorylated ASC were inhibited by ethanol. Finally, multiple alcohol-containing organic compounds exerted inhibitory effects on the Nlrp3 inflammasome, whereas 2-methylbutane (isopentane), the analogous alkane of the potent inhibitor isoamyl alcohol (isopentanol), did not. Our results demonstrate that ethanol antagonizes the NLRP3 inflammasome at an apical event in its activation through the stimulation of protein tyrosine phosphatases, an effect shared by other

  8. Monoterpenes: Novel insights into their biological effects and roles on glucose uptake and lipid metabolism in 3T3-L1 adipocytes.

    PubMed

    Tan, X C; Chua, K H; Ravishankar Ram, M; Kuppusamy, U R

    2016-04-01

    Various strategies have been adopted to combat complications caused by Type 2 diabetes mellitus and controlled diet is one of them. Monoterpenes, major constituents of essential oils, are synthesized and widely used as artificial food flavors. A series of twelve monoterpenes were assessed in the present study. Monoterpenes, exhibited low 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity even at high concentrations. Some monoterpenes inhibited α-amylase and α-glucosidase activity and stimulated glucose uptake and lipolysis. Monoterpenes such as (R)-(+)-limonene stimulated both glucose uptake (17.4%) and lipolysis (17.7%); the mRNA expression of glucose transporter 1 (GLUT1) was upregulated but glucose transporter 4 (GLUT4) was unaffected, and adipose triglyceride lipase (ATGL) was suppressed. Taken together, the selected monoterpenes may not confer strong protection against free radicals but nevertheless, their positive influence on lipid and glucose metabolism may have potential in the control of obesity and Type 2 diabetes mellitus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Lipid-based formulations for danazol containing a digestible surfactant, Labrafil M2125CS: in vivo bioavailability and dynamic in vitro lipolysis.

    PubMed

    Larsen, Anne; Holm, René; Pedersen, Mette Lund; Müllertz, Anette

    2008-12-01

    To evaluate the use of Labrafil M2125CS as a lipid vehicle for danazol. Further, the possibility of predicting the in vivo behavior with a dynamic in vitro lipolysis model was evaluated. Danazol (28 mg/kg) was administered orally to rats in four formulations: an aqueous suspension, two suspensions in Labrafil M2125CS (1 and 2 ml/kg) and a solution in Labrafil M2125CS (4 ml/kg). The obtained absolute bioavailabilities of danazol were 1.5 +/- 0.8%; 7.1 +/- 0.6%; 13.6 +/- 1.4% and 13.3 +/- 3.4% for the aqueous suspension, 1, 2 and 4 ml Labrafil M2125CS per kg respectively. Thus administration of danazol with Labrafil M2125CS resulted in up to a ninefold increase in the bioavailability, and the bioavailability was dependent on the Labrafil M2125CS dose. In vitro lipolysis of the formulations was able to predict the rank order of the bioavailability from the formulations, but not the absorption profile of the in vivo study. The bioavailability of danazol increased when Labrafil M2125CS was used as a vehicle, both when danazol was suspended and solubilized in the vehicle. The dynamic in vitro lipolysis model could be used to rank the bioavailabilities of the in vivo data.

  10. Tumour-promoting phorbol esters increase basal and inhibit insulin-stimulated lipogenesis in rat adipocytes without decreasing insulin binding.

    PubMed Central

    van de Werve, G; Proietto, J; Jeanrenaud, B

    1985-01-01

    In isolated rat adipocytes, tumour-promoting phorbol esters caused (1) dose-dependent stimulation of lipogenesis in the absence of insulin and (2) inhibition of the lipogenic effect of submaximal concentrations of insulin, but without affecting insulin binding. The possible involvement of protein kinase C in insulin action is discussed. PMID:3883992

  11. FABP4 inhibition suppresses PPARγ activity and VLDL-induced foam cell formation in IL-4-polarized human macrophages.

    PubMed

    Boss, Marcel; Kemmerer, Marina; Brüne, Bernhard; Namgaladze, Dmitry

    2015-06-01

    Macrophages, converted to lipid-loaded foam cells, accumulate in atherosclerotic lesions. Macrophage lipid metabolism is transcriptionally regulated by peroxisome proliferator-activated receptor gamma (PPARγ), and its target gene fatty acid binding protein 4 (FABP4) accelerates the progression of atherosclerosis in mouse models. Since expression of PPARγ and FABP4 is increased upon interleukin-4 (IL-4)-induced macrophage polarization, we aimed to investigate the role of FABP4 in human IL-4-polarized macrophages. We investigated the impact of FABP4 on PPARγ-dependent gene expression in primary human monocytes differentiated to macrophages in the presence of IL-4. IL-4 increased PPARγ and its target genes lipoprotein lipase (LPL) and FABP4 compared to non-polarized or LPS/interferon γ-stimulated macrophages. LPL expression correlated with increased very low density lipoprotein (VLDL)-induced triglyceride accumulation in IL-4-polarized macrophages, which was sensitive to inhibition of lipolysis or PPARγ antagonism. Inhibition of FABP4 during differentiation using chemical inhibitors BMS309403 and HTS01037 or FABP4 siRNA decreased the expression of FABP4 and LPL, and reduced lipid accumulation in macrophages treated with VLDL. FABP4 or LPL inhibition also reduced the expression of inflammatory mediators chemokine (C-C motif) ligand 2 (CCL2) and IL-1β in response to VLDL in IL-4-polarized macrophages. PPARγ luciferase reporter assays confirmed that FABP4 supports fatty acid-induced PPARγ activation. Our findings suggest that IL-4 induces a lipid-accumulating macrophage phenotype by activating PPARγ and subsequent LPL expression. Inhibition of FABP4 decreases VLDL-induced foam cell formation, indicating that anti-atherosclerotic effects achieved by FABP4 inhibition in mouse models may be feasible in the human system as well. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Ursolic acid isolated from guava leaves inhibits inflammatory mediators and reactive oxygen species in LPS-stimulated macrophages.

    PubMed

    Kim, Min-Hye; Kim, Jin Nam; Han, Sung Nim; Kim, Hye-Kyeong

    2015-06-01

    Psidium guajava (guava) leaves have been frequently used for the treatment of rheumatism, fever, arthritis and other inflammatory conditions. The purpose of this study was to identify major anti-inflammatory compounds from guava leaf extract. The methanol extract and its hexane-, dichloromethane-, ethylacetate-, n-butanol- and water-soluble phases derived from guava leaves were evaluated to determine their inhibitory activity on nitric oxide (NO) production by RAW 264.7 cells stimulated with lipopolysaccharide (LPS). The methanol extract decreased NO production in a dose-dependent manner without cytotoxicity at a concentration range of 0-100 μg/mL. The n-butanol soluble phase was the most potent among the five soluble phases. Four compounds were isolated by reversed-phase HPLC from the n-butanol soluble phase and identified to be avicularin, guaijaverin, leucocyanidin and ursolic acid by their NMR spectra. Among these compounds, ursolic acid inhibited LPS-induced NO production in a dose-dependent manner without cytotoxity at a concentration range of 1-10 µM, but the other three compounds had no effect. Ursolic acid also inhibited LPS-induced prostaglandin E2 production. A western blot analysis showed that ursolic acid decreased the LPS-stimulated inducible nitric oxide synthase and cyclooxygenase protein levels. In addition, ursolic acid suppressed the production of intracellular reactive oxygen species in LPS-stimulated RAW 264.7 cells, as measured by flow cytometry. Taken together, these results identified ursolic acid as a major anti-inflammatory compound in guava leaves.

  13. The role of right prefrontal and medial cortex in response inhibition: interfering with action restraint and action cancellation using transcranial magnetic brain stimulation.

    PubMed

    Dambacher, Franziska; Sack, Alexander T; Lobbestael, Jill; Arntz, Arnoud; Brugmann, Suzanne; Schuhmann, Teresa

    2014-08-01

    The ability of inhibiting impulsive urges is paramount for human behavior. Such successful response inhibition has consistently been associated with activity in pFC. The current study aims to unravel the differential involvement of different areas within right pFC for successful action restraint versus action cancellation. These two conceptually different aspects of action inhibition were measured with a go/no-go task (action restraint) and a stop signal task (action cancellation). Localization of relevant prefrontal activation was based on fMRI data. Significant task-related activation during successful action restraint was localized for each participant individually in right anterior insula (rAI), right superior frontal gyrus, and pre-SMA. Activation during successful action cancellation was localized in rAI, right middle frontal gyrus, and pre-SMA. Subsequently, fMRI-guided continuous thetaburst stimulation was applied to these regions. Results showed that the disruption of neural activity in rAI reduced both the ability to restrain (go/no-go) and cancel (stop signal) responses. In contrast, continuous thetaburst stimulation-induced disruption of the right superior frontal gyrus specifically impaired the ability to restrain from responding (go/no-go), while leaving the ability for action cancellation largely intact. Stimulation applied to right middle frontal gyrus and pre-SMA did not affect inhibitory processing in neither of the two tasks. These findings provide a more comprehensive perspective on the role of pFC in inhibition and cognitive control. The results emphasize the role of inferior frontal regions for global inhibition, whereas superior frontal regions seem to be specifically relevant for successful action restraint.

  14. Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pilot study.

    PubMed

    Hubbard, Gary P; Wolffram, Siegfried; de Vos, Ric; Bovy, Arnaud; Gibbins, Jonathan M; Lovegrove, Julie A

    2006-09-01

    Epidemiological data suggest that those who consume a diet rich in quercetin-containing foods may have a reduced risk of CVD. Furthermore, in vitro and ex vivo studies have observed the inhibition of collagen-induced platelet activation by quercetin. The aim of the present study was to investigate the possible inhibitory effects of quercetin ingestion from a dietary source on collagen-stimulated platelet aggregation and signalling. A double-blind randomised cross-over pilot study was undertaken. Subjects ingested a soup containing either a high or a low amount of quercetin. Plasma quercetin concentrations and platelet aggregation and signalling were assessed after soup ingestion. The high-quercetin soup contained 69 mg total quercetin compared with the low-quercetin soup containing 5 mg total quercetin. Plasma quercetin concentrations were significantly higher after high-quercetin soup ingestion than after low-quercetin soup ingestion and peaked at 2.59 (sem 0.42) mumol/l. Collagen-stimulated (0.5 mug/ml) platelet aggregation was inhibited after ingestion of the high-quercetin soup in a time-dependent manner. Collagen-stimulated tyrosine phosphorylation of a key component of the collagen-signalling pathway via glycoprotein VI, Syk, was significantly inhibited by ingestion of the high-quercetin soup. The inhibition of Syk tyrosine phosphorylation was correlated with the area under the curve for the high-quercetin plasma profile. In conclusion, the ingestion of quercetin from a dietary source of onion soup could inhibit some aspects of collagen-stimulated platelet aggregation and signalling ex vivo. This further substantiates the epidemiological data suggesting that those who preferentially consume high amounts of quercetin-containing foods have a reduced risk of thrombosis and potential CVD risk.

  15. Polycystin-1 interacts with TAZ to stimulate osteoblastogenesis and inhibit adipogenesis

    DOE PAGES

    Xiao, Zhousheng; Baudry, Jerome; Cao, Li; ...

    2017-11-27

    The molecular mechanisms that transduce the osteoblast response to physical forces in the bone microenvironment are poorly understood. In this paper, we used genetic and pharmacological experiments to determine whether the polycystins PC1 and PC2 (encoded by Pkd1 and Pkd2) and the transcriptional coactivator TAZ form a mechanosensing complex in osteoblasts. Compound-heterozygous mice lacking 1 copy of Pkd1 and Taz exhibited additive decrements in bone mass, impaired osteoblast-mediated bone formation, and enhanced bone marrow fat accumulation. Bone marrow stromal cells and osteoblasts derived from these mice showed impaired osteoblastogenesis and enhanced adipogenesis. Increased extracellular matrix stiffness and application of mechanicalmore » stretch to multipotent mesenchymal cells stimulated the nuclear translocation of the PC1 C-terminal tail/TAZ (PC1-CTT/TAZ) complex, leading to increased runt-related transcription factor 2–mediated (Runx2-mediated) osteogenic and decreased PPARγ-dependent adipogenic gene expression. Using structure-based virtual screening, we identified a compound predicted to bind to PC2 in the PC1:PC2 C-terminal tail region with helix:helix interaction. This molecule stimulated polycystin- and TAZ-dependent osteoblastogenesis and inhibited adipogenesis. Therefore, we show that polycystins and TAZ integrate at the molecular level to reciprocally regulate osteoblast and adipocyte differentiation, indicating that the polycystins/TAZ complex may be a potential therapeutic target to increase bone mass.« less

  16. Polycystin-1 interacts with TAZ to stimulate osteoblastogenesis and inhibit adipogenesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xiao, Zhousheng; Baudry, Jerome; Cao, Li

    The molecular mechanisms that transduce the osteoblast response to physical forces in the bone microenvironment are poorly understood. In this paper, we used genetic and pharmacological experiments to determine whether the polycystins PC1 and PC2 (encoded by Pkd1 and Pkd2) and the transcriptional coactivator TAZ form a mechanosensing complex in osteoblasts. Compound-heterozygous mice lacking 1 copy of Pkd1 and Taz exhibited additive decrements in bone mass, impaired osteoblast-mediated bone formation, and enhanced bone marrow fat accumulation. Bone marrow stromal cells and osteoblasts derived from these mice showed impaired osteoblastogenesis and enhanced adipogenesis. Increased extracellular matrix stiffness and application of mechanicalmore » stretch to multipotent mesenchymal cells stimulated the nuclear translocation of the PC1 C-terminal tail/TAZ (PC1-CTT/TAZ) complex, leading to increased runt-related transcription factor 2–mediated (Runx2-mediated) osteogenic and decreased PPARγ-dependent adipogenic gene expression. Using structure-based virtual screening, we identified a compound predicted to bind to PC2 in the PC1:PC2 C-terminal tail region with helix:helix interaction. This molecule stimulated polycystin- and TAZ-dependent osteoblastogenesis and inhibited adipogenesis. Therefore, we show that polycystins and TAZ integrate at the molecular level to reciprocally regulate osteoblast and adipocyte differentiation, indicating that the polycystins/TAZ complex may be a potential therapeutic target to increase bone mass.« less

  17. Positive effects of Forskolin (stimulator of lipolysis) treatment on cryosurvival of in vitro matured porcine oocytes.

    PubMed

    Fu, Xiang-Wei; Wu, Guo-Quan; Li, Jun-Jie; Hou, Yun-Peng; Zhou, Guang-Bin; Lun-Suo; Wang, Yan-Ping; Zhu, Shi-En

    2011-01-15

    In order to examine its effect on oocyte lipid content and cryosurvival, Forskolin was added to the medium for in vitro maturation of porcine oocytes. Treatments were control (IVM without Forskolin during the 42 h incubation period), addition of 10 μM Forskolin for the entire 42 h (0-42) and addition of 10 μM Forskolin between 24 and 42 h only (24-42). In Experiment 1, treatments did not differ significantly in cleavage rate, but the blastocyst formation rate was lower in the 0-42 group than for control and 24-42 group oocytes (17, 32 and 40%, respectively; P < 0.05). It was shown in Experiment 2 that Forskolin treatment from 0-42 h and from 24-42 h significantly reduced lipid content of oocytes compared to that of control cells (65 and 99 vs. 140 μm(2) intensity of fluorescence, respectively; P < 0.05). In Experiment 3, the percentage of oocyte survival after cryopreservation and thawing was significantly higher in both Forskolin treatment groups than in control oocytes (72% for 0-42, 65% for 24-42 and 52% for control; P < 0.05). However, Forskolin treatment did not increase cleavage rates of vitrified in vitro matured porcine oocytes (Control group 28%, 0-42 h group 0%, 24-42 h group 26.67%). Addition of Forskolin affected the nuclear maturation of porcine oocytes. The percentage of PBE (polar body extrusion) were significantly reduced in the 0-42 h group (0-42 h group 42.00 ± 2.08 vs. Control group 79.70 ± 2.82 and 24-42 h group 70.60 ± 2.83; P < 0.05). The 24-42 h group showed similar nuclear status to that of the Control group. We propose that delipation engendered by incubation with 10 μM Forskolin during 24-42 hours of maturation increased cryosurvival of in vitro-maturated porcine oocytes and that attendant chemical lipolysis did not impair their further development as it may have done in oocytes incubated with Forskolin for the full 42 h. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Exploring the contributions of the supplementary eye field to subliminal inhibition using double-pulse transcranial magnetic stimulation.

    PubMed

    Chiau, Hui-Yan; Muggleton, Neil G; Juan, Chi-Hung

    2017-01-01

    It is widely accepted that the supplementary eye fields (SEF) are involved in the control of voluntary eye movements. However, recent evidence suggests that SEF may also be important for unconscious and involuntary motor processes. Indeed, Sumner et al. ([2007]: Neuron 54:697-711) showed that patients with micro-lesions of the SEF demonstrated an absence of subliminal inhibition as evoked by masked-prime stimuli. Here, we used double-pulse transcranial magnetic stimulation (TMS) in healthy volunteers to investigate the role of SEF in subliminal priming. We applied double-pulse TMS at two time windows in a masked-prime task: the first during an early phase, 20-70 ms after the onset of the mask but before target presentation, during which subliminal inhibition is present; and the second during a late phase, 20-70 ms after target onset, during which the saccade is being prepared. We found no effect of TMS with the early time window of stimulation, whereas a reduction in the benefit of an incompatible subliminal prime stimulus was found when SEF TMS was applied at the late time window. These findings suggest that there is a role for SEF related to the effects of subliminal primes on eye movements, but the results do not support a role in inhibiting the primed tendency. Hum Brain Mapp 38:339-351, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Parenteral and enteral metabolism of anaplerotic triheptanoin in normal rats. II. Effects on lipolysis, glucose production, and liver acyl-CoA profile

    PubMed Central

    Gu, Lei; Zhang, Guo-Fang; Kombu, Rajan S.; Allen, Frederick; Kutz, Gerd; Brewer, Wolf-Ulrich; Roe, Charles R.

    2010-01-01

    The anaplerotic odd-medium-chain triglyceride triheptanoin is used in clinical trials for the chronic dietary treatment of patients with long-chain fatty acid oxidation disorders. We previously showed (Kinman RP, Kasumov T, Jobbins KA, Thomas KR, Adams JE, Brunengraber LN, Kutz G, Brewer WU, Roe CR, Brunengraber H. Am J Physiol Endocrinol Metab 291: E860–E866, 2006) that the intravenous infusion of triheptanoin increases lipolysis traced by the turnover of glycerol. In this study, we tested whether lipolysis induced by triheptanoin infusion is accompanied by the potentially harmful release of long-chain fatty acids. Rats were infused with heptanoate ± glycerol or triheptanoin. Intravenous infusion of triheptanoin at 40% of caloric requirement markedly increased glycerol endogenous Ra but not oleate endogenous Ra. Thus, the activation of lipolysis was balanced by fatty acid reesterification in the same cells. The liver acyl-CoA profile showed the accumulation of intermediates of heptanoate β-oxidation and C5-ketogenesis and a decrease in free CoA but no evidence of metabolic perturbation of liver metabolism such as propionyl overload. Our data suggest that triheptanoin, administered either intravenously or intraduodenally, could be used for intensive care and nutritional support of metabolically decompensated long-chain fatty acid oxidation disorders. PMID:19903863

  20. A Citrus bergamia Extract Decreases Adipogenesis and Increases Lipolysis by Modulating PPAR Levels in Mesenchymal Stem Cells from Human Adipose Tissue

    PubMed Central

    Lo Furno, Debora; Avola, Rosanna; Bonina, Francesco; Mannino, Giuliana

    2016-01-01

    The aim of this research was to assess the impact of a well-characterized extract from Citrus bergamia juice on adipogenesis and/or lipolysis using mesenchymal stem cells from human adipose tissue as a cell model. To evaluate the effects on adipogenesis, some cell cultures were treated with adipogenic medium plus 10 or 100 μg/mL of extract. To determine the properties on lipolysis, additional mesenchymal stem cells were cultured with adipogenic medium for 14 days and after this time added with Citrus bergamia for further 14 days. To verify adipogenic differentiation, oil red O staining at 7, 14, 21, and 28 days was performed. Moreover, the expression of peroxisome proliferator-activated receptor gamma (PPAR-γ), adipocytes fatty acid-binding protein (A-FABP), adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), monoglyceride lipase (MGL), 5′-adenosine monophosphate-activated protein kinase (AMPK)α1/2, and pAMPKα1/2 was evaluated by Western blot analysis and the release of glycerol by colorimetric assay. Citrus bergamia extract suppressed the accumulation of intracellular lipids in mesenchymal stem cells during adipogenic differentiation and promoted lipolysis by repressing the expression of adipogenic genes and activating lipolytic genes. Citrus bergamia extract could be a useful natural product for improving adipose mobilization in obesity-related disorders. PMID:27403151

  1. Aculeatin, a coumarin derived from Toddalia asiatica (L.) Lam., enhances differentiation and lipolysis of 3T3-L1 adipocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Watanabe, Akio, E-mail: watanabea@jfrl.or.jp; Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi 981-8555; Kato, Tsuyoshi

    Highlights: • Aculeatin promoted adipocyte differentiation. • Aculeatin improved glucose uptake. • Aculeatin enhanced adipocyte lipolysis. - Abstract: Toddalia asiatica (L.) Lam. (T. asiatica) has been utilized traditionally for medicinal purposes such as the treatment of diabetes. Currently, the extract is considered to be a good source of anti-diabetic agents, but the active compounds have yet to be identified. In this study, we investigated the effects of fractionated T. asiatica extracts on the differentiation of 3T3-L1 preadipocytes and identified aculeatin as a potential active agent. When 3T3-L1 preadipocytes were treated with aculeatin isolated from T. asiatica in the presence ofmore » insulin, aculeatin increased cellular triglyceride levels and glycerol-3-phosphate dehydrogenase activity. This indicated that aculeatin could enhance the differentiation of preadipocytes into adipocytes. Further analyses using a DNA microarray and real-time quantitative reverse-transcription PCR showed an increase in the expression of peroxisome proliferator-activated receptor-γ target genes (Pparg, Ap2, Cd36, Glut4 and Adipoq) by aculeatin, suggesting that aculeatin enhances the differentiation of 3T3-L1 cells by modulating the expression of genes critical for adipogenesis. Interestingly, after treatment of differentiated adipocytes with aculeatin, glucose uptake and lipolysis were enhanced. Overall, our results suggested that aculeatin is an active compound in T. asiatica for enhancing both differentiation and lipolysis of adipocytes, which are useful for the treatment of lipid abnormalities as well as diabetes.« less

  2. Inhibition by somatostatin (growth-hormone release-inhibiting hormone, GH-RIH) of gastric acid and pepsin and G-cell release of gastrin.

    PubMed Central

    Barros D'sa, A A; Bloom, S R; Baron, J H

    1978-01-01

    Somatostatin (cyclic growth-hormone release-inhibiting hormone--GH-RIH) was infused into dogs with gastric fistulae. Somatostatin inhibited gastric acid response to four gastric stimulants--insulin, food, histamine, and pentagastrin. Histamine- and pentagastrin-stimulated pepsins were inhibited similarly to inhibition of acid. Somatostatin inhibited the gastrin response to insulin and food. PMID:348581

  3. A sunflower WRKY transcription factor stimulates the mobilization of seed-stored reserves during germination and post-germination growth.

    PubMed

    Raineri, Jesica; Hartman, Matías D; Chan, Raquel L; Iglesias, Alberto A; Ribichich, Karina F

    2016-09-01

    The sunflower transcription factor HaWRKY10 stimulates reserves mobilization in Arabidopsis. Gene expression and enzymes activity assays indicated that lipolysis and gluconeogenesis were increased. Microarray results suggested a parallelism in sunflower. Germinating oilseeds converts stored lipids into sugars, and thereafter in metabolic energy that is used in seedling growth and establishment. During germination, the induced lipolysis linked to the glyoxylate pathway and gluconeogenesis produces sucrose, which is then transported to the embryo and driven through catabolic routes. Herein, we report that the sunflower transcription factor HaWRKY10 regulates carbon partitioning by reducing carbohydrate catabolism and increasing lipolysis and gluconeogenesis. HaWRKY10 was regulated by abscisic acid and gibberellins in the embryo leaves 48 h after seed imbibition and highly expressed during sunflower seed germination and seedling growth, concomitantly with lipid mobilization. Sunflower leaf disks overexpressing HaWRKY10 showed repressed expression of genes related to sucrose cleavage and glycolysis compared with controls. Moreover, HaWRKY10 constitutive expression in Arabidopsis seeds produced higher decrease in lipid reserves, whereas starch and sucrose were more preserved compared with wild type. Gene transcripts abundance and enzyme activities involved in stored lipid mobilization and gluconeogenesis increased more in transgenic than in wild type seeds 36 h after imbibition, whereas the negative regulator of lipid mobilization, ABI4, was repressed. Altogether, the results point out a functional parallelism between tissues and plant species, and reveal HaWRKY10 as a positive regulator of storage reserve mobilization in sunflower.

  4. AD6 (8-monochloro-3-beta-diethylamino-ethyl-4-methyl-7-ethoxycarbonyl-meth oxy coumarin) inhibits the release of arachidonic acid in human platelets stimulated by thrombin

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Porcellati, S.; Costantini, V.; Prosdocimi, M.

    1987-07-01

    The coumarin derivative AD6 is known to inhibit platelet aggregation and release and it possesses vasodilatory properties on coronary arteries of laboratory animals. Furthermore, the inhibition of the production of TxB2 from endogenous substrates after stimulation of human platelets with collagen has been demonstrated. The present report demonstrates that AD6 inhibits the production of labeled arachidonic acid and diglycerides from phospholipids of platelets stimulated with thrombin. This effect is dose-dependent and is already evident at a concentration of the drug (25 microM) which is unable to prevent the aggregation. Apparently, AD6 inhibits the release of arachidonic acid from phosphatidylinositol andmore » choline phosphoglycerides which are the main sources of the substrate for the synthesis of prostaglandins and thromboxanes.« less

  5. Glycosyl glycerides from hydroponic Panax ginseng inhibited NO production in lipopolysaccharide-stimulated RAW264.7 cells

    PubMed Central

    Cha, Byeong-Ju; Park, Ji-Hae; Shrestha, Sabina; Baek, Nam-In; Lee, Sang Min; Lee, Tae Hoon; Kim, Jiyoung; Kim, Geum-Soog; Kim, Seung-Yu; Lee, Dae-Young

    2014-01-01

    Background Although the aerial parts of hydroponic Panax ginseng are reported to contain higher contents of total ginsenosides than those of roots, the isolation and identification of active metabolites from the aerial parts of hydroponic P. ginseng have not been carried out so far. Methods The aerial parts of hydroponic P. ginseng were applied on repeated silica gel and octadecylsilane columns to yield four glycosyl glycerides (Compounds 1–4), which were identified based on nuclear magnetic resonance, infrared, fast atom bombardment mass spectrometry, and gas chromatography/mass spectrometry data. Compounds 1–4 were evaluated for inhibition activity on NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Results and conclusion The glycosyl glycerides were identified to be (2S)-1-O-7(Z),10(Z),13(Z)-hexadecatrienoyl-3-O-β-d-galactopyranosyl-sn-glycerol (1), (2S)-1-O-linolenoyl-3-O-β-d-galactopyranosyl-sn-glycerol (2), (2S)-1-O-linolenoyl-2-O-linolenoyl-3-O-β-d-galactopyranosyl-sn-glycerol (3), and 2(S)-1-O-linoleoyl-2-O-linoleoyl-3-O-β-d-galactopyranosyl-sn-glycerol (4). Compounds 1 and 2 showed moderate inhibition activity on NO production in LPS-stimulated RAW264.7 cells [half maximal inhibitory concentration (IC50): 63.8 ± 6.4μM and 59.4 ± 6.8μM, respectively] without cytotoxicity at concentrations < 100μM, whereas Compounds 3 and 4 showed good inhibition effect (IC50: 7.7 ± 0.6μM and 8.0 ± 0.9μM, respectively) without cytotoxicity at concentrations < 20μM. All isolated compounds showed reduced messenger RNA (mRNA) expression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α in LPS-induced macrophage cells with strong inhibition of mRNA activity observed for Compounds 3 and 4. PMID:26045690

  6. A novel PKB/Akt inhibitor, MK-2206, effectively inhibits insulin-stimulated glucose metabolism and protein synthesis in isolated rat skeletal muscle.

    PubMed

    Lai, Yu-Chiang; Liu, Yang; Jacobs, Roxane; Rider, Mark H

    2012-10-01

    PKB (protein kinase B), also known as Akt, is a key component of insulin signalling. Defects in PKB activation lead to insulin resistance and metabolic disorders, whereas PKB overactivation has been linked to tumour growth. Small-molecule PKB inhibitors have thus been developed for cancer treatment, but also represent useful tools to probe the roles of PKB in insulin action. In the present study, we examined the acute effects of two allosteric PKB inhibitors, MK-2206 and Akti 1/2 (Akti) on PKB signalling in incubated rat soleus muscles. We also assessed the effects of the compounds on insulin-stimulated glucose uptake, glycogen and protein synthesis. MK-2206 dose-dependently inhibited insulin-stimulated PKB phosphorylation, PKBβ activity and phosphorylation of PKB downstream targets (including glycogen synthase kinase-3α/β, proline-rich Akt substrate of 40 kDa and Akt substrate of 160 kDa). Insulin-stimulated glucose uptake, glycogen synthesis and glycogen synthase activity were also decreased by MK-2206 in a dose-dependent manner. Incubation with high doses of MK-2206 (10 μM) inhibited insulin-induced p70 ribosomal protein S6 kinase and 4E-BP1 (eukaryotic initiation factor 4E-binding protein-1) phosphorylation associated with increased eEF2 (eukaryotic elongation factor 2) phosphorylation. In contrast, Akti only modestly inhibited insulin-induced PKB and mTOR (mammalian target of rapamycin) signalling, with little or no effect on glucose uptake and protein synthesis. MK-2206, rather than Akti, would thus be the tool of choice for studying the role of PKB in insulin action in skeletal muscle. The results point to a key role for PKB in mediating insulin-stimulated glucose uptake, glycogen synthesis and protein synthesis in skeletal muscle.

  7. Effects of insulin-induced hypoglycaemia on lipolysis rate, lipid oxidation and adipose tissue signalling in human volunteers: a randomised clinical study.

    PubMed

    Voss, Thomas S; Vendelbo, Mikkel H; Kampmann, Ulla; Pedersen, Steen B; Nielsen, Thomas S; Johannsen, Mogens; Svart, Mads V; Jessen, Niels; Møller, Niels

    2017-01-01

    The aims of this study were to determine the role of lipolysis in hypoglycaemia and define the underlying intracellular mechanisms. Nine healthy volunteers were randomised to treatment order of three different treatments (crossover design). Treatments were: (1) saline control; (2) hyperinsulinaemic hypoglycaemia (HH; i.v. bolus of 0.1 U/kg insulin); and (3) hyperinsulinaemic euglycaemia (HE; i.v. bolus of 0.1 U/kg insulin and 20% glucose). Inclusion criteria were that volunteers were healthy, aged >18 years, had a BMI between 19 and 26 kg/m 2 , and provided both written and oral informed consent. Exclusion criteria were the presence of a known chronic disease (including diabetes mellitus, epilepsy, ischaemic heart disease and cardiac arrhythmias) and regular use of prescription medication. The data was collected at the medical research facilities at Aarhus University Hospital, Denmark. The primary outcome was palmitic acid flux. Participants were blinded to intervention order, but caregivers were not. Adrenaline (epinephrine) and glucagon concentrations were higher during HH than during both HE and control treatments. NEFA levels and lipid oxidation rates (determined by indirect calorimetry) returned to control levels after 105 min. Palmitate flux was increased to control levels during HH (p = NS) and was more than twofold higher than during HE (overall mean difference between HH vs HE, 114 [95% CI 64, 165 μmol/min]; p < 0.001). In subcutaneous adipose tissue biopsies, we found elevated levels of hormone-sensitive lipase (HSL) and perilipin-1 phosphorylation 30 min after insulin injection during HH compared with both control and HE. There were no changes in the levels of adipose triglyceride lipase (ATGL), comparative gene identification-58 (CGI-58) or G 0 /G 1 switch gene 2 (G0S2) proteins. Insulin-stimulated phosphorylation of Akt and mTOR were unaffected by hypoglycaemia. Expression of the G0S2 gene increased during HE and HH compared with

  8. Stimulation versus inhibition--bioactivity of parthenin, a phytochemical from Parthenium hysterophorus L.

    PubMed

    Belz, Regina G

    2007-09-30

    Parthenium hysterophorus L. is an invasive weed that biosynthesizes several phytochemicals. The sesquiterpene lactone parthenin receives most attention regarding allelopathy of the plant or potential herbicidal properties. Since parthenin exhibits dose-dependent phytotoxicity with low dose stimulation, this study investigated the occurrence and temporal features of parthenin hormesis in Sinapis arvensis L. sprayed with parthenin under semi-natural conditions. Dose/response studies showed that the occurrence and the magnitude of hormesis depended on climatic conditions and the parameter measured. Within the tested dose range, stimulatory responses were only observed under less-stressful conditions and were most pronounced for leaf area growth [138 % of control; 13 days after treatment (DAT)]. Temporal assessment of leaf area development showed that doses causing a stimulatory response at the end of the experiment (< 0.42 +/- 0.04 kg/ha; 13 DAT) were initially inhibitory up to ED(50) values (2 DAT). This clearly demonstrated an over-compensatory response. Inhibition of leaf area at 13 DAT reached ED(50) values on average at 0.62 +/-0.12 kg/ha, and S. arvensis was completely inhibited at doses exceeding 1.81 +/-0.56 kg/ha (ED(90)). Based on these findings, implications of parthenin hormesis are discussed with respect to allelopathy of P. hysterophorus and exploitation of growth stimulatory responses in agriculture.

  9. Methotrexate inhibits neutrophil function by stimulating adenosine release from connective tissue cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cronstein, B.N.; Eberle, M.A.; Levin, R.I.

    1991-03-15

    Although commonly used to control a variety of inflammatory diseases, the mechanism of action of a low dose of methotrexate remains a mystery. Methotrexate accumulates intracellularly where it may interfere with purine metabolism. Therefore, the authors determined whether a 48-hr pretreatment with methotrexate affected adenosine release from ({sup 14}C)adenine-labeled human fibroblasts and umbilical vein endothelial cells. Methotrexate significantly increased adenosine release by fibroblasts. The effect of methotrexate on adenosine release was not due to cytotoxicity since cells treated with maximal concentrations of methotrexate took up ({sup 14}C)adenine and released {sup 14}C-labeled purine (a measure of cell injury) in a mannermore » identical to control cells. Methotrexate treatment of fibroblasts dramatically inhibited adherence to fibroblasts by both unstimulated neutrophils and stimulated neutrophils. One hypothesis that explains the effect of methotrexate on adenosine release is that, by inhibition of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase, methotrexate induces the accumulation of AICAR, the nucleoside precursor of which has previously been shown to cause adenosine release from ischemic cardiac tissue. The observation that the antiinflammatory actions of methotrexate are due to the capacity of methotrexate to induce adenosine release may form the basis for the development of an additional class of antiinflammatory drugs.« less

  10. Inhibition of Lateral Prefrontal Cortex Produces Emotionally Biased First Impressions: A Transcranial Magnetic Stimulation and Electroencephalography Study.

    PubMed

    Lapate, Regina C; Samaha, Jason; Rokers, Bas; Hamzah, Hamdi; Postle, Bradley R; Davidson, Richard J

    2017-07-01

    Optimal functioning in everyday life requires the ability to override reflexive emotional responses and prevent affective spillover to situations or people unrelated to the source of emotion. In the current study, we investigated whether the lateral prefrontal cortex (lPFC) causally regulates the influence of emotional information on subsequent judgments. We disrupted left lPFC function using transcranial magnetic stimulation (TMS) and recorded electroencephalography (EEG) before and after. Subjects evaluated the likeability of novel neutral faces after a brief exposure to a happy or fearful face. We found that lPFC inhibition biased evaluations of novel faces according to the previously processed emotional expression. Greater frontal EEG alpha power, reflecting increased inhibition by TMS, predicted increased behavioral bias. TMS-induced affective misattribution was long-lasting: Emotionally biased first impressions formed during lPFC inhibition were still detectable outside of the laboratory 3 days later. These findings indicate that lPFC serves an important emotion-regulation function by preventing incidental emotional encoding from automatically biasing subsequent appraisals.

  11. Perilipin ablation results in a lean mouse with aberrant adipocyte lipolysis, enhanced leptin production, and resistance to diet-induced obesity.

    PubMed

    Tansey, J T; Sztalryd, C; Gruia-Gray, J; Roush, D L; Zee, J V; Gavrilova, O; Reitman, M L; Deng, C X; Li, C; Kimmel, A R; Londos, C

    2001-05-22

    Perilipin coats the lipid droplets of adipocytes and is thought to have a role in regulating triacylglycerol hydrolysis. To study the role of perilipin in vivo, we have created a perilipin knockout mouse. Perilipin null (peri(-/-)) and wild-type (peri(+/+)) mice consume equal amounts of food, but the adipose tissue mass in the null animals is reduced to approximately 30% of that in wild-type animals. Isolated adipocytes of perilipin null mice exhibit elevated basal lipolysis because of the loss of the protective function of perilipin. They also exhibit dramatically attenuated stimulated lipolytic activity, indicating that perilipin is required for maximal lipolytic activity. Plasma leptin concentrations in null animals were greater than expected for the reduced adipose mass. The peri(-/-) animals have a greater lean body mass and increased metabolic rate but they also show an increased tendency to develop glucose intolerance and peripheral insulin resistance. When fed a high-fat diet, the perilipin null animals are resistant to diet-induced obesity but not to glucose intolerance. The data reveal a major role for perilipin in adipose lipid metabolism and suggest perilipin as a potential target for attacking problems associated with obesity.

  12. Reductions in the Cardiac Transient Outward K+ Current Ito Caused by Chronic β-Adrenergic Receptor Stimulation Are Partly Rescued by Inhibition of Nuclear Factor κB.

    PubMed

    Panama, Brian K; Korogyi, Adam S; Aschar-Sobbi, Roozbeh; Oh, Yena; Gray, Charles B B; Gang, Hongying; Brown, Joan Heller; Kirshenbaum, Lorrie A; Backx, Peter H

    2016-02-19

    The fast transient outward potassium current (Ito,f) plays a critical role in the electrical and contractile properties of the myocardium. Ito,f channels are formed by the co-assembly of the pore-forming α-subunits, Kv4.2 and Kv4.3, together with the accessory β-subunit KChIP2. Reductions of Ito,f are common in the diseased heart, which is also associated with enhanced stimulation of β-adrenergic receptors (β-ARs). We used cultured neonatal rat ventricular myocytes to examine how chronic β-AR stimulation decreases Ito,f. To determine which downstream pathways mediate these Ito,f changes, adenoviral infections were used to inhibit CaMKIIδc, CaMKIIδb, calcineurin, or nuclear factor κB (NF-κB). We observed that chronic β-AR stimulation with isoproterenol (ISO) for 48 h reduced Ito,f along with mRNA expression of all three of its subunits (Kv4.2, Kv4.3, and KChIP2). Inhibiting either CaMKIIδc nor CaMKIIδb did not prevent the ISO-mediated Ito,f reductions, even though CaMKIIδc and CaMKIIδb clearly regulated Ito,f and the mRNA expression of its subunits. Likewise, calcineurin inhibition did not prevent the Ito,f reductions induced by β-AR stimulation despite strongly modulating Ito,f and subunit mRNA expression. In contrast, NF-κB inhibition partly rescued the ISO-mediated Ito,f reductions in association with restoration of KChIP2 mRNA expression. Consistent with these observations, KChIP2 promoter activity was reduced by p65 as well as β-AR stimulation. In conclusion, NF-κB, and not CaMKIIδ or calcineurin, partly mediates the Ito,f reductions induced by chronic β-AR stimulation. Both mRNA and KChIP2 promoter data suggest that the ISO-induced Ito,f reductions are, in part, mediated through reduced KChIP2 transcription caused by NF-κB activation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. An examination of the effects of subthalamic nucleus inhibition or μ-opioid receptor stimulation on food-directed motivation in the non-deprived rat

    PubMed Central

    Pratt, Wayne E.; Choi, Eugene; Guy, Elizabeth G.

    2012-01-01

    The subthalamic nucleus (STN) serves important functions in regulating movement, cognition, and motivation and is connected with cortical and basal ganglia circuits that process reward and reinforcement. In order to further examine the role of the STN on motivation toward food in non-deprived rats, these experiments studied the effects of pharmacological inhibition or μ-opioid receptor stimulation of the STN on the 2-hr intake of a sweetened fat diet, the amount of work exerted to earn sucrose on a progressive ratio 2 (PR-2) schedule of reinforcement, and performance on a differential reinforcement of low-rate responding (DRL) schedule for sucrose reward. Separate behavioral groups (N = 6–9) were tested following bilateral inhibition of the STN with the GABAA receptor agonist muscimol (at 0–5 ng/0.5 μl/side) or following μ-opioid receptor stimulation with the agonist D-Ala2, N-MePhe4, Gly-ol-enkephalin (DAMGO; at 0, 0.025 or 0.25 μg/0.5 μl/side). Although STN inhibition increased ambulatory behavior during 2-hr feeding sessions, it did not significantly alter intake of the sweetened fat diet. STN inhibition also did not affect the breakpoint for sucrose pellets during a 1-hr PR-2 reinforcement schedule or impact the number of reinforcers earned on a 1-hr DRL-20 sec reinforcement schedule in non-deprived rats. In contrast, STN μ-opioid receptor stimulation significantly increased feeding on the palatable diet and reduced the reinforcers earned on a DRL-20 schedule, although DAMGO microinfusions had no effect on PR-2 performance. These data suggest that STN inhibition does not enhance incentive motivation for food in the absence of food restriction and that STN μ-opioid receptors play an important and unique role in motivational processes. PMID:22391117

  14. Relationships between root density of the African grass Hyparrhenia diplandra and nitrification at the decimetric scale: an inhibition-stimulation balance hypothesis.

    PubMed Central

    Lata, J C; Guillaume, K; Degrange, V; Abbadie, L; Lensi, R

    2000-01-01

    Previous studies have shown that Lamto savannah exhibits two different types of nitrogen cycle with high and low nitrification sites and suggested that the perennial grass Hyparrhenia diplandra is responsible for this duality at a subpopulation level, with one ecotype being thought to be able to inhibit nitrification. The present work aimed to investigate the relationships between nitrification and the roots of H. diplandra at two scales. (i) Site-scale experiments gave new insight into the hypothesized control of nitrification by H. diplandra tussocks: the two ecotypes exhibited opposite influences, inhibition in a low nitrification site (A) and stimulation in a high nitrification site (B). (ii) Decimetric-scale experiments demonstrated close negative or positive relationships (in sites A or B, respectively) between the roots and nitrification (in the 0-10 cm soil layer), showing an unexpectedly high sensitivity of the nitrification process to root density. In both soils, the correlation between the roots and nitrification decreased with depth and practically disappeared in the 20-30 cm soil layer (where the nitrification potential was found to be very low). Therefore, the impact of H. diplandra on nitrification may be viewed as an inhibition-stimulation balance. PMID:10787164

  15. Potassium uptake supporting plant growth in the absence of AKT1 channel activity: Inhibition by ammonium and stimulation by sodium

    NASA Technical Reports Server (NTRS)

    Spalding, E. P.; Hirsch, R. E.; Lewis, D. R.; Qi, Z.; Sussman, M. R.; Lewis, B. D.

    1999-01-01

    A transferred-DNA insertion mutant of Arabidopsis that lacks AKT1 inward-rectifying K+ channel activity in root cells was obtained previously by a reverse-genetic strategy, enabling a dissection of the K+-uptake apparatus of the root into AKT1 and non-AKT1 components. Membrane potential measurements in root cells demonstrated that the AKT1 component of the wild-type K+ permeability was between 55 and 63% when external [K+] was between 10 and 1,000 microM, and NH4+ was absent. NH4+ specifically inhibited the non-AKT1 component, apparently by competing for K+ binding sites on the transporter(s). This inhibition by NH4+ had significant consequences for akt1 plants: K+ permeability, 86Rb+ fluxes into roots, seed germination, and seedling growth rate of the mutant were each similarly inhibited by NH4+. Wild-type plants were much more resistant to NH4+. Thus, AKT1 channels conduct the K+ influx necessary for the growth of Arabidopsis embryos and seedlings in conditions that block the non-AKT1 mechanism. In contrast to the effects of NH4+, Na+ and H+ significantly stimulated the non-AKT1 portion of the K+ permeability. Stimulation of akt1 growth rate by Na+, a predicted consequence of the previous result, was observed when external [K+] was 10 microM. Collectively, these results indicate that the AKT1 channel is an important component of the K+ uptake apparatus supporting growth, even in the "high-affinity" range of K+ concentrations. In the absence of AKT1 channel activity, an NH4+-sensitive, Na+/H+-stimulated mechanism can suffice.

  16. A Novel Apolipoprotein C-II Mimetic Peptide That Activates Lipoprotein Lipase and Decreases Serum Triglycerides in Apolipoprotein E–Knockout Mice

    PubMed Central

    Sakurai, Toshihiro; Sakurai-Ikuta, Akiko; Sviridov, Denis; Freeman, Lita; Ahsan, Lusana; Remaley, Alan T.

    2015-01-01

    Apolipoprotein A-I (apoA-I) mimetic peptides are currently being developed as possible new agents for the treatment of cardiovascular disease based on their ability to promote cholesterol efflux and their other beneficial antiatherogenic properties. Many of these peptides, however, have been reported to cause transient hypertriglyceridemia due to inhibition of lipolysis by lipoprotein lipase (LPL). We describe a novel bihelical amphipathic peptide (C-II-a) that contains an amphipathic helix (18A) for binding to lipoproteins and stimulating cholesterol efflux as well as a motif based on the last helix of apolipoprotein C-II (apoC-II) that activates lipolysis by LPL. The C-II-a peptide promoted cholesterol efflux from ATP-binding cassette transporter ABCA1-transfected BHK cells similar to apoA-I mimetic peptides. Furthermore, it was shown in vitro to be comparable to the full-length apoC-II protein in activating lipolysis by LPL. When added to serum from a patient with apoC-II deficiency, it restored normal levels of LPL-induced lipolysis and also enhanced lipolysis in serum from patients with type IV and V hypertriglyceridemia. Intravenous injection of C-II-a (30 mg/kg) in apolipoprotein E–knockout mice resulted in a significant reduction of plasma cholesterol and triglycerides of 38 ± 6% and 85 ± 7%, respectively, at 4 hours. When coinjected with the 5A peptide (60 mg/kg), the C-II-a (30 mg/kg) peptide was found to completely block the hypertriglyceridemic effect of the 5A peptide in C57Bl/6 mice. In summary, C-II-a is a novel peptide based on apoC-II, which promotes cholesterol efflux and lipolysis and may therefore be useful for the treatment of apoC-II deficiency and other forms of hypertriglyceridemia. PMID:25395590

  17. Right-sided vagus nerve stimulation inhibits induced spinal cord seizures.

    PubMed

    Tubbs, R Shane; Salter, E George; Killingsworth, Cheryl; Rollins, Dennis L; Smith, William M; Ideker, Raymond E; Wellons, John C; Blount, Jeffrey P; Oakes, W Jerry

    2007-01-01

    We have previously shown that left-sided vagus nerve stimulation results in cessation of induced spinal cord seizures. To test our hypothesis that right-sided vagus nerve stimulation will also abort seizure activity, we have initiated seizures in the spinal cord and then performed right-sided vagus nerve stimulation in an animal model. Four pigs were anesthetized and placed in the lateral position and a small laminectomy performed in the lumbar region. Topical penicillin, a known epileptogenic drug to the cerebral cortex and spinal cord, was next applied to the dorsal surface of the exposed cord. With the exception of the control animal, once seizure activity was discernible via motor convulsion or increased electrical activity, the right vagus nerve previously isolated in the neck was stimulated. Following multiple stimulations of the vagus nerve and with seizure activity confirmed, the cord was transected in the midthoracic region and vagus nerve stimulation performed. Right-sided vagus nerve stimulation resulted in cessation of spinal cord seizure activity in all animals. Transection of the spinal cord superior to the site of seizure induction resulted in the ineffectiveness of vagus nerve stimulation in causing cessation of seizure activity in all study animals. As with left-sided vagus nerve stimulation, right-sided vagus nerve stimulation results in cessation of induced spinal cord seizures. Additionally, the effects of right-sided vagus nerve stimulation on induced spinal cord seizures involve descending spinal pathways. These data may aid in the development of alternative mechanisms for electrical stimulation for patients with medically intractable seizures and add to our knowledge regarding the mechanism for seizure cessation following peripheral nerve stimulation.

  18. Des-acyl ghrelin inhibits the capacity of macrophages to stimulate the expression of aromatase in breast adipose stromal cells.

    PubMed

    Au, CheukMan C; Docanto, Maria M; Zahid, Heba; Raffaelli, Francesca-Maria; Ferrero, Richard L; Furness, John B; Brown, Kristy A

    2017-06-01

    Des-acyl ghrelin is the unacylated form of the well-characterized appetite-stimulating hormone ghrelin. It affects a number of physiological processes, including increasing adipose lipid accumulation and inhibiting adipose tissue inflammation. Breast adipose tissue inflammation in obesity is associated with an increase in the expression of the estrogen biosynthetic enzyme, aromatase, and is hypothesized to create a hormonal milieu conducive to tumor growth. We previously reported that des-acyl ghrelin inhibits the expression and activity of aromatase in isolated human adipose stromal cells (ASCs), the main site of aromatase expression in the adipose tissue. The current study aimed to examine the effect of des-acyl ghrelin on the capacity of mouse macrophages (RAW264.7 cells) and human adipose tissue macrophages (ATMs) to stimulate aromatase expression in primary human breast ASCs. RAW264.7 cells were treated with 0, 10 and 100pM des-acyl ghrelin following activation with phorbol 12-myristate 13-acetate, and cells and conditioned media were collected after 6 and 24h. The effect of des-acyl ghrelin on macrophage polarization was examined by assessing mRNA expression of pro-inflammatory M1-specific marker Cd11c and anti-inflammatory M2-specific marker Cd206, as well as expression of Tnf and Ptgs2, known mediators of the macrophage-dependent stimulation of aromatase. TNF protein in conditioned media was assessed by ELISA. The effect of RAW264.7 and ATM-conditioned media on aromatase expression in ASCs was assessed after 6h. Results demonstrate des-acyl ghrelin significantly increases the expression of Cd206 and suppresses the expression of Cd11c, Tnf and Ptgs2 in activated RAW264.7 cells. Treatment of RAW264.7 and ATMs with des-acyl ghrelin also significantly reduces the capacity of these cells to stimulate aromatase transcript expression in human breast ASCs. Overall, these findings suggest that in addition to direct effects on aromatase in ASCs, des-acyl ghrelin also

  19. [Transcranial magnetic stimulation (TMS), inhibition processes and attention deficit/hyperactivity disorder (ADHD) - an overview].

    PubMed

    Hoegl, Thomas; Bender, Stephan; Buchmann, Johannes; Kratz, Oliver; Moll, Gunther H; Heinrich, Hartmut

    2014-11-01

    Motor system excitability can be tested by transcranial magnetic stimulation CFMS). In this article, an overview of recent methodological developments and research findings related to attention deficit/hyperactivity disorder (ADHD) is provided. Different TMS parameters that reflect the function of interneurons in the motor cortex may represent neurophysiological markers of inhibition in ADHD, particularly the so-called intracortical inhibition. In children with a high level of hyperactivity and impulsivity, intracortical inhibition was comparably low at rest as shortly before the execution of a movement. TMS-evoked potentials can also be measured in the EEG so that investigating processes of excitability is not restricted to motor areas in future studies. The effects of methylphenidate on motor system excitability may be interpreted in the sense of a 'fine-tuning' with these mainly dopaminergic effects also depending on genetic parameters (DAT1 transporter). A differentiated view on the organization of motor control can be achieved by a combined analysis of TMS parameters and event-related potentials. Applying this bimodal approach, strong evidence for a deviant implementation of motor control in children with ADHD and probably compensatory mechanisms (with involvement of the prefrontal cortex) was obtained. These findings, which contribute to a better understanding of hyperactivity/impulsivity, inhibitory processes and motor control in ADHD as well as the mechanisms of medication, underline the relevance of TMS as a neurophysiological method in ADHD research.

  20. Paired associative stimulation induces change in presynaptic inhibition of Ia terminals in wrist flexors in humans.

    PubMed

    Lamy, Jean-Charles; Russmann, Heike; Shamim, Ejaz A; Meunier, Sabine; Hallett, Mark

    2010-08-01

    Enhancements in the strength of corticospinal projections to muscles are induced in conscious humans by paired associative stimulation (PAS) to the motor cortex. Although most of the previous studies support the hypothesis that the increase of the amplitude of motor evoked potentials (MEPs) by PAS involves long-term potentiation (LTP)-like mechanism in cortical synapses, changes in spinal excitability after PAS have been reported, suggestive of parallel modifications in both cortical and spinal excitability. In a first series of experiments (experiment 1), we confirmed that both flexor carpi radialis (FCR) MEPs and FCR H reflex recruitment curves are enhanced by PAS. To elucidate the mechanism responsible for this change in the H reflex amplitude, we tested, using the same subjects, the hypothesis that enhanced H reflexes are caused by a down-regulation of the efficacy of mechanisms controlling Ia afferent discharge, including presynaptic Ia inhibition and postactivation depression. To address this question, amounts of both presynaptic Ia inhibition of FCR Ia terminals (D1 and D2 inhibitions methods; experiment 2) and postactivation depression (experiment 3) were determined before and after PAS. Results showed that PAS induces a significant decrease of presynaptic Ia inhibition of FCR terminals, which was concomitant with the facilitation of the H reflex. Postactivation depression was unaffected by PAS. It is argued that enhancement of segmental excitation by PAS relies on a selective effect of PAS on the interneurons controlling presynaptic inhibition of Ia terminals.

  1. Lactoferrin from Camelus dromedarius Inhibits Nuclear Transcription Factor-kappa B Activation, Cyclooxygenase-2 Expression and Prostaglandin E2 Production in Stimulated Human Chondrocytes

    PubMed Central

    Rasheed, Naila; Alghasham, Abdullah; Rasheed, Zafar

    2016-01-01

    Background: Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. Nuclear factor-kappa B (NF)-κB is a major cellular event in OA and its activation by interleukin-1β (IL-1β) plays a critical role in cartilage breakdown in these patients. Objective: In this study, we examined the effect of lactoferrin on NF-κB activation, cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production in stimulated human articular chondrocytes. Materials and Methods: Human chondrocytes were derived from OA articular cartilage and treated with camel lactoferrin and then stimulated with IL-1β. Gene expression was determined by TaqMan assays and protein expression was studied by Western immunoblotting. NF-κB activity and PGE2 levels were determined by ELISA based assays. NF-κB activity was also determined by treatment of chondrocytes with NF-κB specific inhibitor Bay 11–7082. Results: Lactoferrin inhibited IL-1β-induced activation and nuclear translocation of NF-κB p65 in human OA chondrocytes. Lactoferrin also inhibited mRNA/protein expression of COX-2 and production of PGE2. Moreover, Bay 11–7082 also inhibited IL-1β-induced expression of COX-2 and production of PGE2. The inhibitory effect of lactoferrin on the IL-1β induced expression of COX-2 or production of PGE2 was mediated at least in part via suppression of NF-κB activation. Conclusions: Our data determine camel lactoferrin as a novel inhibitor of IL-1β-induced activation of NF-κB signaling events and production of cartilage-degrading molecule PGE2 via inhibition of COX-2 expressions. These results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA and other degenerative/inflammatory diseases. SUMMARY Lactoferrin shows anti-arthritic activity in IL-1β stimulated primary human chondrocytes.Lactoferrin inhibits IL-1β-induced NF-κB activation.Lactoferrin inhibits

  2. Lactoferrin from Camelus dromedarius Inhibits Nuclear Transcription Factor-kappa B Activation, Cyclooxygenase-2 Expression and Prostaglandin E2 Production in Stimulated Human Chondrocytes.

    PubMed

    Rasheed, Naila; Alghasham, Abdullah; Rasheed, Zafar

    2016-01-01

    Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. Nuclear factor-kappa B (NF)-κB is a major cellular event in OA and its activation by interleukin-1β (IL-1β) plays a critical role in cartilage breakdown in these patients. In this study, we examined the effect of lactoferrin on NF-κB activation, cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production in stimulated human articular chondrocytes. Human chondrocytes were derived from OA articular cartilage and treated with camel lactoferrin and then stimulated with IL-1β. Gene expression was determined by TaqMan assays and protein expression was studied by Western immunoblotting. NF-κB activity and PGE2 levels were determined by ELISA based assays. NF-κB activity was also determined by treatment of chondrocytes with NF-κB specific inhibitor Bay 11-7082. Lactoferrin inhibited IL-1β-induced activation and nuclear translocation of NF-κB p65 in human OA chondrocytes. Lactoferrin also inhibited mRNA/protein expression of COX-2 and production of PGE2. Moreover, Bay 11-7082 also inhibited IL-1β-induced expression of COX-2 and production of PGE2. The inhibitory effect of lactoferrin on the IL-1β induced expression of COX-2 or production of PGE2 was mediated at least in part via suppression of NF-κB activation. Our data determine camel lactoferrin as a novel inhibitor of IL-1β-induced activation of NF-κB signaling events and production of cartilage-degrading molecule PGE2 via inhibition of COX-2 expressions. These results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA and other degenerative/inflammatory diseases. Lactoferrin shows anti-arthritic activity in IL-1β stimulated primary human chondrocytes.Lactoferrin inhibits IL-1β-induced NF-κB activation.Lactoferrin inhibits production of cartilage degrading PGE2 via inhibition of COX-2 expression

  3. 1-[N, O-bis-(5-isoquinolinesulphonyl)-N-methyl-L-tyrosyl]-4- phenylpiperazine (KN-62), an inhibitor of calcium-dependent camodulin protein kinase II, inhibits both insulin- and hypoxia-stimulated glucose transport in skeletal muscle.

    PubMed Central

    Brozinick, J T; Reynolds, T H; Dean, D; Cartee, G; Cushman, S W

    1999-01-01

    Previous studies have indicated a role for calmodulin in hypoxia-and insulin-stimulated glucose transport. However, since calmodulin interacts with multiple protein targets, it is unknown which of these targets is involved in the regulation of glucose transport. In the present study, we have used the calcium-dependent calmodulin protein kinase II (CAMKII) inhibitor 1-[N, O-bis-(5-isoquinolinesulphonyl) -N-methyl-L-tyrosyl]-4-phenylpiperazine (KN-62) to investigate the possible role of this enzyme in the regulation of glucose transport in isolated rat soleus and epitrochlearis muscles. KN-62 did not affect basal 2-deoxyglucose transport, but it did inhibit both insulin- and hypoxia-stimulated glucose transport activity by 46 and 40% respectively. 1-[N,O-Bis-(1, 5-isoquinolinesulphonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine (KN-04), a structural analogue of KN-62 that does not inhibit CAMKII, had no effect on hypoxia-or insulin-stimulated glucose transport. Accordingly, KN-62 decreased the stimulated cell-surface GLUT4 labelling by a similar extent as the inhibition of glucose transport (insulin, 49% and hypoxia, 54%). Additional experiments showed that KN-62 also inhibited insulin- and hypoxia-stimulated transport by 37 and 40% respectively in isolated rat epitrochlearis (a fast-twitch muscle), indicating that the effect of KN-62 was not limited to the slow-twitch fibres of the soleus. The inhibitory effect of KN-62 on hypoxia-stimulated glucose transport appears to be specific to CAMKII, since KN-62 did not inhibit hypoxia-stimulated 45Ca efflux from muscles pre-loaded with 45Ca, or hypoxia-stimulated glycogen breakdown. Additionally, KN-62 affected neither insulin-stimulated phosphoinositide 3-kinase nor Akt activity, suggesting that the effects of KN-62 are not due to non-specific effects of this inhibitor on these regions of the insulin-signalling cascade. The results of the present study suggest that CAMKII might have a distinct role in insulin- and hypoxia-stimulated

  4. Tumor necrosis factor receptor-1 can function through a G alpha q/11-beta-arrestin-1 signaling complex.

    PubMed

    Kawamata, Yuji; Imamura, Takeshi; Babendure, Jennie L; Lu, Juu-Chin; Yoshizaki, Takeshi; Olefsky, Jerrold M

    2007-09-28

    Tumor necrosis factor-alpha (TNFalpha) is a proinflammatory cytokine secreted from macrophages and adipocytes. It is well known that chronic TNFalpha exposure can lead to insulin resistance both in vitro and in vivo and that elevated blood levels of TNFalpha are observed in obese and/or diabetic individuals. TNFalpha has many acute biologic effects, mediated by a complex intracellular signaling pathway. In these studies we have identified new G-protein signaling components to this pathway in 3T3-L1 adipocytes. We found that beta-arrestin-1 is associated with TRAF2 (TNF receptor-associated factor 2), an adaptor protein of TNF receptors, and that TNFalpha acutely stimulates tyrosine phosphorylation of G alpha(q/11) with an increase in G alpha(q/11) activity. Small interfering RNA-mediated knockdown of beta-arrestin-1 inhibits TNFalpha-induced tyrosine phosphorylation of G alpha(q/11) by interruption of Src kinase activation. TNFalpha stimulates lipolysis in 3T3-L1 adipocytes, and beta-arrestin-1 knockdown blocks the effects of TNFalpha to stimulate ERK activation and glycerol release. TNFalpha also led to activation of JNK with increased expression of the proinflammatory gene, monocyte chemoattractant protein-1 and matrix metalloproteinase 3, and beta-arrestin-1 knockdown inhibited both of these effects. Taken together these results reveal novel elements of TNFalpha action; 1) the trimeric G-protein component G alpha(q/11) and the adapter protein beta-arrestin-1 can function as signaling molecules in the TNFalpha action cascade; 2) beta-arrestin-1 can couple TNFalpha stimulation to ERK activation and lipolysis; 3) beta-arrestin-1 and G alpha(q/11) can mediate TNFalpha-induced phosphatidylinositol 3-kinase activation and inflammatory gene expression.

  5. Hippocampal low-frequency stimulation inhibits afterdischarge and increases GABA (A) receptor expression in amygdala-kindled pharmacoresistant epileptic rats.

    PubMed

    Wu, Guofeng; Wang, Likun; Hong, Zhen; Ren, Siying; Zhou, Feng

    2017-08-01

    The purpose of the present study was to observe the effects of hippocampal low-frequency stimulation (Hip-LFS) on amygdala afterdischarge and GABA (A) receptor expression in pharmacoresistant epileptic (PRE) rats. A total of 110 healthy adult male Wistar rats were used to generate a model of epilepsy by chronic stimulation of the amygdala. Sixteen PRE rats were selected from 70 amygdala-kindled rats by testing their response to Phenytoin and Phenobarbital, and they were randomly assigned to a pharmacoresistant stimulation group (PRS group, 8 rats) or a pharmacoresistant control group (PRC group, 8 rats). A stimulation electrode was implanted into the hippocampus of all of the rats. Hip-LFS was administered twice per day in the PRS group for two weeks. Simultaneously, amygdala stimulus-induced seizures and afterdischarge were recorded. After the hippocampal stimulation was terminated, the brain tissues were obtained to determine the GABA (A) receptors by a method of immumohistochemistry and a real-time polymerase chain reaction. The stages and duration of the amygdala stimulus-induced epileptic seizures were decreased in the PRS group. The afterdischarge threshold was increased and the duration as well as the afterdischarge frequency was decreased. Simultaneously, the GABA (A) expression was significantly increased in the PRS group. Hip-LFS may inhibit amygdala stimulus-induced epileptic seizures and up-regulate GABA (A) receptor expression in PRE rats. The antiepileptic effects of hippocampal stimulation may be partly achieved by increasing the GABA (A) receptor.

  6. Effect of the presence of protein on lipolysis and lipid oxidation occurring during in vitro digestion of highly unsaturated oils.

    PubMed

    Nieva-Echevarría, Bárbara; Goicoechea, Encarnación; Guillén, María D

    2017-11-15

    The effect of the presence of ovalbumin and soy protein isolate on lipolysis and oxidation taking place during in vitro gastrointestinal digestion of slightly oxidized sunflower and flaxseed oils was addressed. The extent of lipolysis, the molar proportions of acyl groups/fatty acids after digestion, and the oxidation products formed were studied by Proton Nuclear Magnetic Resonance. The presence of proteins provoked a higher hydrolysis in triglycerides, a lower decrease of polyunsaturated chains, and a lower generation of oxidation compounds (conjugated dienes in chains having also hydroperoxy/hydroxy groups, epoxides and aldehydes); the formation of hydroxides was clearly favoured over that of hydroperoxides. Study of headspace composition by Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry confirmed that oxidation advanced to a lesser extent in the presence of protein. Thus, amino acids/peptides released during digestion may show antioxidant properties, affecting not only the extent of lipid oxidation, but also reactions pathways. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Inhibition of neurotensin-stimulated mast cell secretion and carboxypeptidase A activity by the peptide inhibitor of carboxypeptidase A and neurotensin-receptor antagonist SR 48692.

    PubMed

    Miller, L A; Cochrane, D E; Feldberg, R S; Carraway, R E

    1998-06-01

    Neurotensin (NT), a peptide found in brain and several peripheral tissues, is a potent stimulus for mast cell secretion and its actions are blocked by the specific NT receptor antagonist, SR 48692. Subsequent to stimulation, NT is rapidly degraded by mast cell carboxypeptidase A (CPA). In the experiments described here, we tested for the involvement of CPA activity in the activation of mast cell secretion by the peptide, NT. Mast cells were isolated from the peritoneal and pleural cavities of rats, purified over metrizamide gradients and incubated at 37 degrees C in Locke solution or Locke containing the appropriate inhibitors. For some experiments, media derived from mast cells stimulated by compound 48/80 were used as a source of mast cell CPA activity. Treatment of mast cells with the highly specific peptide inhibitor of CPA derived from potato (PCI) inhibited histamine release in response to NT and NT8-13 (the biologically active region of NT). This inhibition required some 20 min to develop and was only partially reversed by a 20-min wash period. PCI (10 microM) did not inhibit histamine release in response to NT1-12, bradykinin, compound 48/80, the calcium ionophore, A23187, or anti-IgE serum. PCI also inhibited mast cell CPA activity. SR 48692, a highly selective antagonist of the brain NT receptor and of NT-stimulated mast cell secretion, also inhibited mast cell CPA activity as well as bovine pancreatic CPA activity in a concentration-dependent manner. It is suggested that the mast cell binding site for NT and the active site for CPA may share similar characteristics. The results are discussed in terms of NT mechanism of action on the mast cell.

  8. Olanzapine promotes fat accumulation in male rats by decreasing physical activity, repartitioning energy and increasing adipose tissue lipogenesis while impairing lipolysis.

    PubMed

    Albaugh, V L; Judson, J G; She, P; Lang, C H; Maresca, K P; Joyal, J L; Lynch, C J

    2011-05-01

    Olanzapine and other atypical antipsychotics cause metabolic side effects leading to obesity and diabetes; although these continue to be an important public health concern, their underlying mechanisms remain elusive. Therefore, an animal model of these side effects was developed in male Sprague-Dawley rats. Chronic administration of olanzapine elevated fasting glucose, impaired glucose and insulin tolerance, increased fat mass but, in contrast to female rats, did not increase body weight or food intake. Acute studies were conducted to delineate the mechanisms responsible for these effects. Olanzapine markedly decreased physical activity without a compensatory decline in food intake. It also acutely elevated fasting glucose and worsened oral glucose and insulin tolerance, suggesting that these effects are adiposity independent. Hyperinsulinemic-euglycemic clamp studies measuring (14)C-2-deoxyglucose uptake revealed tissue-specific insulin resistance. Insulin sensitivity was impaired in skeletal muscle, but either unchanged or increased in adipose tissue depots. Consistent with the olanzapine-induced hyperglycemia, there was a tendency for increased (14)C-2-deoxyglucose uptake into fat depots of fed rats and, surprisingly, free fatty acid (FFA) uptake into fat depots was elevated approximately twofold. The increased glucose and FFA uptake into adipose tissue was coupled with increased adipose tissue lipogenesis. Finally, olanzapine lowered fasting plasma FFA, and as it had no effect on isoproterenol-stimulated rises in plasma glucose, it blunted isoproterenol-stimulated in vivo lipolysis in fed rats. Collectively, these results suggest that olanzapine exerts several metabolic effects that together favor increased accumulation of fuel into adipose tissue, thereby increasing adiposity.

  9. IR spectroscopy analysis of pancreatic lipase-related protein 2 interaction with phospholipids: 3. Monitoring DPPC lipolysis in mixed micelles.

    PubMed

    Mateos-Diaz, Eduardo; Sutto-Ortiz, Priscila; Sahaka, Moulay; Rodriguez, Jorge A; Carrière, Frédéric

    2018-03-01

    Usual methods for the continuous assay of lipolytic enzyme activities are mainly based on the titration of free fatty acids, surface pressure monitoring or spectrophotometry using substrates labeled with specific probes. These approaches only give a partial information on the chemistry of the lipolysis reaction and additional end-point analyses are often required to quantify both residual substrate and lipolysis products. We used transmission infrared (IR) spectroscopy to monitor simultaneously the hydrolysis of phospholipids by guinea pig pancreatic lipase-related protein 2 (GPLRP2) and the release of lipolysis products. The substrate (DPPC, 1,2-Dipalmitoyl phosphatidylcholine) was mixed with sodium taurodeoxycholate (NaTDC) to form mixed micelles in D 2 O buffer at pD 6 and 8. After hydrogen/deuterium exchange, DPPC hydrolysis by GPLRP2 (100nM) was monitored at 35°C in a liquid cell by recording IR spectra and time-course variations in the CO stretching region. These changes were correlated to variations in the concentrations of DPPC, lysophospholipids (lysoPC) and palmitic acid (Pam) using calibration curves established with these compounds individually mixed with NaTDC. We were thus able to quantify each compound and its time-course variations during the phospholipolysis reaction and to estimate the enzyme activity. To validate the IR analysis, variations in residual DPPC, lysoPC and Pam were also quantified by thin-layer chromatography coupled to densitometry and similar hydrolysis profiles were obtained using both methods. IR spectroscopy can therefore be used to monitor the enzymatic hydrolysis of phospholipids and obtain simultaneously chemical and physicochemical information on substrate and all reaction products (H-bonding, hydration, acyl chain mobility). Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Induction of autocrine factor inhibiting cell motility from murine B16-BL6 melanoma cells by alpha-melanocyte stimulating hormone.

    PubMed

    Murata, J; Ayukawa, K; Ogasawara, M; Watanabe, H; Saiki, I

    1999-03-15

    We have previously reported that neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) successfully inhibited Matrigel invasion and haptotactic migration of B16-BL6 melanoma cells towards both fibronectin and laminin without affecting their growth. In the present study, we investigated the inhibitory mechanism of tumor cell motility by alpha-MSH. Alpha-MSH significantly blocked the autocrine motility factor (AMF)-enhanced cell motility. However, alpha-MSH did neither prevent the secretion of AMF from B16-BL6 cells nor alter the expression level of AMF receptor (gp78). On the other hand, alpha-MSH induced the secretion of the motility inhibitory factor(s) from B16-BL6 cells in a concentration- and time-dependent manner. The induction of the motility inhibitor(s) was proportional to increasing levels of intracellular cAMP induced by alpha-MSH as well as forskolin, and the activity was abolished by an adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (DDA). The motility-inhibiting activity in conditioned medium (CM) from alpha-MSH-treated B16-BL6 cells was found to have a m.w. below 3 kDa after fractionation. This activity was abolished by boiling but insensitive to trypsin. The treatment of tumor cells with cycloheximide reduced the activity in alpha-MSH-stimulated CM. Our results suggest that alpha-MSH inhibited the motility of B16-BL6 cells through induction of autocrine factor(s).

  11. Gastrodin inhibits osteoclastogenesis via down-regulating the NFATc1 signaling pathway and stimulates osseointegration in vitro

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhou, Feng; Shen, Yi; Liu, Bo

    Bone is a rigid yet dynamic organ, and this dynamism is mediated by the delicate balance between osteoclastic bone resorption and osteoblastic bone formation. However, excessive activation of osteoclasts is responsible for many bone diseases such as osteoporosis, Paget disease, and tumor bone metastasis. Agents that could inhibit osteoclast formation or function are regarded as promising alternatives to treat osteoclast-related diseases. Recently, traditional Chinese medicine has attracted attention because of its multiple activities in bone metabolism. Among them, gastrodin has been reported as an anti-osteoporosis agent that reduces reactive oxygen species. However, the direct action of gastrodin on osteoclast differentiationmore » and bone resorption, and its underlying molecular mechanism, remain unknown. In this study, we investigated the effects of gastrodin on receptor activator NF-κB ligand (RANKL)-activated osteoclasts formation and bone resorption. Our results showed that gastrodin retarded RANKL-induced osteoclast differentiation efficiently by downregulating transcriptional and translational expression of nuclear factor of activated T cells cl (NFATc1), a major factor in RANKL-mediated osteoclastogenesis. Meanwhile, gastrodin prevented osteoclast maturation and migration by inhibiting the gene expression of dendrocyte expressed seven transmembrane protein (DC-STAMP), an osteoclastic-specific gene that controls cells fusion and movement. And gastrodin prevented RANKL-induced osteoclastic bone erosion in vitro. In addition, gastrodin also stimulated bone mesenchymal stem cell (BMSC) spreading and osseointegration in titanium plate. In summary, gastrodin could prevent osteoclasts formation and bone resorption via blockage of NFATc1 activity, and stimulate osseointegration in vitro. Gastrodin could be developed as a potent phytochemical candidate to treat osteolytic diseases. - Highlights: • Gastrodin suppresses osteoclasts formation and function in

  12. An Antagonistic Vascular Endothelial Growth Factor (VEGF) Variant Inhibits VEGF-Stimulated Receptor Autophosphorylation and Proliferation of Human Endothelial Cells

    NASA Astrophysics Data System (ADS)

    Siemeister, Gerhard; Schirner, Michael; Reusch, Petra; Barleon, Bernhard; Marme, Dieter; Martiny-Baron, Georg

    1998-04-01

    Vascular endothelial growth factor (VEGF) is a potent mitogen with a unique specificity for endothelial cells and a key mediator of aberrant endothelial cell proliferation and vascular permeability in a variety of human pathological situations, such as tumor angiogenesis, diabetic retinopathy, rheumatoid arthritis, or psoriasis. VEGF is a symmetric homodimeric molecule with two receptor binding interfaces lying on each pole of the molecule. Herein we report on the construction and recombinant expression of an asymmetric heterodimeric VEGF variant with an intact receptor binding interface at one pole and a mutant receptor binding interface at the second pole of the dimer. This VEGF variant binds to VEGF receptors but fails to induce receptor activation. In competition experiments, the heterodimeric VEGF variant antagonizes VEGF-stimulated receptor autophosphorylation and proliferation of endothelial cells. A 15-fold excess of the heterodimer was sufficient to inhibit VEGF-stimulated endothelial cell proliferation by 50%, and a 100-fold excess resulted in an almost complete inhibition. By using a rational approach that is based on the structure of VEGF, we have shown the feasibility to construct a VEGF variant that acts as an VEGF antagonist.

  13. Lipolysis and thermogenesis in adipose tissues as new potential mechanisms for metabolic benefits of dietary fiber.

    PubMed

    Han, Shu-Fen; Jiao, Jun; Zhang, Wei; Xu, Jia-Ying; Zhang, Weiguo; Fu, Chun-Ling; Qin, Li-Qiang

    2017-01-01

    Dietary fiber consumption is associated with reduced risk for the development of noncommunicable diseases. The aim of the present study was to evaluate the effects of cereal dietary fiber on the levels of proteins involved in lipolysis and thermogenesis in white adipose tissue (WAT) and brown adipose tissue (BAT) of C57 BL/6 J mice fed a high-fat diet (HFD). Male C57BL/6 J mice were fed normal chow diet (Chow), HFD, HFD plus oat fiber (H-oat), or HFD plus wheat bran fiber (H-wheat) for 24 wk. Body weight and food intake were recorded weekly. Serum adiponectin was assayed by an enzyme-linked immunosorbent assay kit. Western blotting was used to assess the protein expressions of adipose triacylglycerol lipase (ATGL), cAMP protein kinase catalytic subunit (cAMP), protein kinase A (PKA), perilipin A, hormone-sensitive lipase (HSL), uncoupling protein 1 (UCP1), fibroblast growth factor 21 (FGF-21), β3-adrenergic receptor (β3AR), and proliferator-activated receptor gamma coactivator-1 α (PGC-1 α) in the WAT and BAT. At the end of the feeding period, body and adipose tissues weight in both H-oat and H-wheat groups were lower than in the HFD group. Mice in the H-oat and H-wheat groups showed an increasing trend in serum adiponectin level. Compared with the HFD group, cereal dietary fiber increased protein expressions involved in the lipolysis and browning process. Compared with the H-wheat group, H-oat was more effective in protein expressions of PKA, PGC-1 α, and UCP1 of the WAT samples. Compared with the H-oat group, H-wheat was more effective in protein expressions of PKA, ATGL, UCP1, β3AR, and FGF-21 of the BAT samples. Taken together, our results suggested that cereal dietary fiber enhanced adipocyte lipolysis by the cAMP-PKA-HSL pathway and promoted WAT browning by activation of UCP1, and consequently reduced visceral fat mass in response to HFD feeding. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. A calcium-dependent protein kinase can inhibit a calmodulin-stimulated Ca2+ pump (ACA2) located in the endoplasmic reticulum of Arabidopsis

    NASA Technical Reports Server (NTRS)

    Hwang, I.; Sze, H.; Harper, J. F.; Evans, M. L. (Principal Investigator)

    2000-01-01

    The magnitude and duration of a cytosolic Ca(2+) release can potentially be altered by changing the rate of Ca(2+) efflux. In plant cells, Ca(2+) efflux from the cytoplasm is mediated by H(+)/Ca(2+)-antiporters and two types of Ca(2+)-ATPases. ACA2 was recently identified as a calmodulin-regulated Ca(2+)-pump located in the endoplasmic reticulum. Here, we show that phosphorylation of its N-terminal regulatory domain by a Ca(2+)-dependent protein kinase (CDPK isoform CPK1), inhibits both basal activity ( approximately 10%) and calmodulin stimulation ( approximately 75%), as shown by Ca(2+)-transport assays with recombinant enzyme expressed in yeast. A CDPK phosphorylation site was mapped to Ser(45) near a calmodulin binding site, using a fusion protein containing the N-terminal domain as an in vitro substrate for a recombinant CPK1. In a full-length enzyme, an Ala substitution for Ser(45) (S45/A) completely blocked the observed CDPK inhibition of both basal and calmodulin-stimulated activities. An Asp substitution (S45/D) mimicked phosphoinhibition, indicating that a negative charge at this position is sufficient to account for phosphoinhibition. Interestingly, prior binding of calmodulin blocked phosphorylation. This suggests that, once ACA2 binds calmodulin, its activation state becomes resistant to phosphoinhibition. These results support the hypothesis that ACA2 activity is regulated as the balance between the initial kinetics of calmodulin stimulation and CDPK inhibition, providing an example in plants for a potential point of crosstalk between two different Ca(2+)-signaling pathways.

  15. Transcranial Direct Current Stimulation of the Temporoparietal Junction and Inferior Frontal Cortex Improves Imitation-Inhibition and Perspective-Taking with no Effect on the Autism-Spectrum Quotient Score.

    PubMed

    Nobusako, Satoshi; Nishi, Yuki; Nishi, Yuki; Shuto, Takashi; Asano, Daiki; Osumi, Michihiro; Morioka, Shu

    2017-01-01

    Lesions to brain regions such as the temporoparietal junction (TPJ) and inferior frontal cortex (IFC) are thought to cause autism-spectrum disorder (ASD). Previous studies indicated that transcranial direct current stimulation (tDCS) of the right TPJ improves social cognitive functions such as imitation-inhibition and perspective-taking. Although previous work shows that tDCS of the right IFC improves imitation-inhibition, its effects on perspective-taking have yet to be determined. In addition, the role of the TPJ and IFC in determining the Autism-Spectrum Quotient (AQ), which is a measure of autism spectrum traits, is still unclear. Thus, the current study performed tDCS on the right TPJ and the right IFC of healthy adults, and examined its effects on imitation-inhibition, perspective-taking and AQ scores. Based on previous studies, we hypothesized that anodal tDCS of the right IFC and right TPJ would improve imitation-inhibition, perspective-taking and the AQ score. Anodal tDCS of the right TPJ or IFC significantly decreased the interference effect in an imitation-inhibition task and the cost of perspective-taking in a perspective-taking task, in comparison to the sham stimulation control. These findings indicated that both the TPJ and the IFC play a role in imitation-inhibition and perspective-taking, i.e., control of self and other representations. However, anodal stimulation of the right TPJ and the right IFC did not alter participants' AQ. This finding conflicts with results from previous brain imaging studies, which could be attributed to methodological differences such as variation in sex, age and ASD. Therefore, further research is necessary to determine the relationship between the TPJ and IFC, and the AQ.

  16. Long-term high-intensity sound stimulation inhibits h current (Ih ) in CA1 pyramidal neurons.

    PubMed

    Cunha, A O S; Ceballos, C C; de Deus, J L; Leão, R M

    2018-05-19

    Afferent neurotransmission to hippocampal pyramidal cells can lead to long-term changes to their intrinsic membrane properties and affect many ion currents. One of the most plastic neuronal currents is the hyperpolarization activated cationic current (I h ), which changes in CA1 pyramidal cells in response to many types of physiological and pathological processes, including auditory stimulation. Recently we demonstrated that long-term potentiation (LTP) in rat hippocampal Schaffer-CA1 synapses is depressed by high-intensity sound stimulation. Here we investigated if a long-term high-intensity sound stimulation could affect intrinsic membrane properties of rat CA1 pyramidal neurons. Our results showed that I h is depressed by long-term high intensity sound exposure (1 minute of 110 dB sound, applied two times per day for 10 days). This resulted in a decreased resting membrane potential, increased membrane input resistance and time constant, and decreased action potential threshold. In addition, CA1 pyramidal neurons from sound-exposed animals fired more action potentials than neurons from control animals; However, this effect was not caused by a decreased I h . Interestingly, a single episode (1 minute) of 110 dB sound stimulation which also inhibits hippocampal LTP did not affect I h and firing in pyramidal neurons, suggesting that effects on I h are long-term responses to high intensity sound exposure. Our results show that prolonged exposure to high-intensity sound affects intrinsic membrane properties of hippocampal pyramidal neurons, mainly by decreasing the amplitude of I h . This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Atorvastatin reduces lipid accumulation in the liver by activating protein kinase A-mediated phosphorylation of perilipin 5.

    PubMed

    Gao, Xing; Nan, Yang; Zhao, Yuanlin; Yuan, Yuan; Ren, Bincheng; Sun, Chao; Cao, Kaiyu; Yu, Ming; Feng, Xuyang; Ye, Jing

    2017-12-01

    Statins have been proven to be effective in treating non-alcoholic fatty liver disease (NAFLD). Recently, it was reported that statins decreased the hepatic expression of perilipin 5 (Plin5), a lipid droplet (LD)-associated protein, which plays critical roles in regulating lipid accumulation and lipolysis in liver. However, the function and regulation mechanism of Plin5 have not yet been well-established in NAFLD treatment with statins. In this study, we observed that atorvastatin moderately reduced the expression of Plin5 in livers without changing the protein level of Plin5 in the hepatic LD fraction of mice fed with high-fat diet (HFD). Intriguingly, atorvastatin stimulated the PKA-mediated phosphorylation of Plin5 and reduced the triglyceride (TG) accumulation in hepatocytes with overexpression of wide type (Plin5-WT) compared to serine-155 mutant Plin5 (Plin5-S155A). Moreover, PKA-stimulated FA release of purified LDs carrying Plin5-WT but not Plin5-S155A. Glucagon, a PKA activator, stimulated the phosphorylation of Plin5-WT and inhibited its interaction with CGI-58. The results indicated that atorvastatin promoted lipolysis and reduced TG accumulation in the liver by increasing PKA-mediated phosphorylation of Plin5. This new mechanism of lipid-lowering effects of atorvastatin might provide a new strategy for NAFLD treatment. Copyright © 2017. Published by Elsevier B.V.

  18. Beneficial effect of mechanical stimulation on the regenerative potential of muscle-derived stem cells is lost by inhibiting vascular endothelial growth factor.

    PubMed

    Beckman, Sarah A; Chen, William C W; Tang, Ying; Proto, Jonathan D; Mlakar, Logan; Wang, Bing; Huard, Johnny

    2013-08-01

    We previously reported that mechanical stimulation increased the effectiveness of muscle-derived stem cells (MDSCs) for tissue repair. The objective of this study was to determine the importance of vascular endothelial growth factor (VEGF) on mechanically stimulated MDSCs in a murine model of muscle regeneration. MDSCs were transduced with retroviral vectors encoding the LacZ reporter gene (lacZ-MDSCs), the soluble VEGF receptor Flt1 (sFlt1-MDSCs), or a short hairpin RNA (shRNA) targeting messenger RNA of VEGF (shRNA_VEGF MDSCs). Cells were subjected to 24 hours of mechanical cyclic strain and immediately transplanted into the gastrocnemius muscles of mdx/scid mice. Two weeks after transplantation, angiogenesis, fibrosis, and regeneration were analyzed. There was an increase in angiogenesis in the muscles transplanted with mechanically stimulated lacZ-MDSCs compared with nonstimulated lacZ-MDSCs, sFlt1-MDSCs, and shRNA _VEGF MDSCs. Dystrophin-positive myofiber regeneration was significantly lower in the shRNA_VEGF-MDSC group compared with the lacZ-MDSC and sFlt1-MDSC groups. In vitro proliferation of MDSCs was not decreased by inhibition of VEGF; however, differentiation into myotubes and adhesion to collagen were significantly lower in the shRNA_VEGF-MDSC group compared with the lacZ-MDSC and sFlt1-MDSC groups. The beneficial effects of mechanical stimulation on MDSC-mediated muscle repair are lost by inhibiting VEGF.

  19. Beneficial Effect of Mechanical Stimulation on the Regenerative Potential of Muscle-Derived Stem Cells Is Lost by Inhibiting Vascular Endothelial Growth Factor

    PubMed Central

    Beckman, Sarah A.; Chen, William C.W.; Tang, Ying; Proto, Jonathan D.; Mlakar, Logan; Wang, Bing; Huard, Johnny

    2016-01-01

    Objective We previously reported that mechanical stimulation increased the effectiveness of muscle-derived stem cells (MDSCs) for tissue repair. The objective of this study was to determine the importance of vascular endothelial growth factor (VEGF) on mechanically stimulated MDSCs in a murine model of muscle regeneration. Approach and Results MDSCs were transduced with retroviral vectors encoding the LacZ reporter gene (lacZ-MDSCs), the soluble VEGF receptor Flt1 (sFlt1-MDSCs), or a short hairpin RNA (shRNA) targeting messenger RNA of VEGF (shRNA_VEGF MDSCs). Cells were subjected to 24 hours of mechanical cyclic strain and immediately transplanted into the gastrocnemius muscles of mdx/scid mice. Two weeks after transplantation, angiogenesis, fibrosis, and regeneration were analyzed. There was an increase in angiogenesis in the muscles transplanted with mechanically stimulated lacZMDSCs compared with nonstimulated lacZ-MDSCs, sFlt1-MDSCs, and shRNA _VEGF MDSCs. Dystrophin-positive myofiber regeneration was significantly lower in the shRNA_VEGF-MDSC group compared with the lacZ-MDSC and sFlt1-MDSC groups. In vitro proliferation of MDSCs was not decreased by inhibition of VEGF; however, differentiation into myotubes and adhesion to collagen were significantly lower in the shRNA_VEGF-MDSC group compared with the lacZ-MDSC and sFlt1-MDSC groups. Conclusions The beneficial effects of mechanical stimulation on MDSC-mediated muscle repair are lost by inhibiting VEGF. PMID:23723372

  20. Stimulation and Inhibition of Anaerobic Digestion by Nickel and Cobalt: A Rapid Assessment Using the Resazurin Reduction Assay.

    PubMed

    Chen, Jian Lin; Steele, Terry W J; Stuckey, David C

    2016-10-03

    Stimulation of anaerobic digestion by essential trace metals is beneficial from a practical point of view to enhance the biodegradability and degradation rate of wastes. Hence, a quick method to determine which metal species, and at what concentration, can optimize anaerobic digestion is of great interest to both researchers and operators. In this present study, we investigated the effect of nickel(II), cobalt(II), and their mixture, on the anaerobic digestion of synthetic municipal wastewater. Using a volumetric method, that is, measuring methane production over time, revealed that anaerobic digestion was stimulated by the addition of 5 mg L -1 nickel(II), and cobalt(II), and their mixture in day(s). However, using a novel resazurin reduction assay, and based on its change in rate over time, we evaluated both inhibition at 250 mg L -1 nickel(II) and cobalt(II), and also the stimulatory effect of 5 mg L -1 nickel(II), and cobalt(II), and their mixture, in just 6 h. By investigating the dynamic distribution of these metals in the liquid phase of the anaerobic system and kinetics of resazurin reduction by nickel spiked anaerobic sludge, the concentration of nickel(II) on anaerobic digestion performance was profiled. Three critical concentrations were determined; stimulation starting (around 1 mg L -1 ), stimulation ending (around 100 mg L -1 ) and stimulation maximizing (around 10 mg L -1 ). Hence, we propose that the resazurin reduction assay is a novel and quick protocol for studying the stimulation of anaerobic bioprocesses by bioavailable essential trace metals.

  1. Dihydrotestosterone inhibits hair growth in mice by inhibiting insulin-like growth factor-I production in dermal papillae.

    PubMed

    Zhao, Juan; Harada, Naoaki; Okajima, Kenji

    2011-10-01

    We demonstrated that insulin-like growth factor-I (IGF-I) production in dermal papillae was increased and hair growth was promoted after sensory neuron stimulation in mice. Although the androgen metabolite dihydrotestosterone (DHT) inhibits hair growth by negatively modulating growth-regulatory effects of dermal papillae, relationship between androgen metabolism and IGF-I production in dermal papillae is not fully understood. We examined whether DHT inhibits IGF-I production by inhibiting sensory neuron stimulation, thereby preventing hair growth in mice. Effect of DHT on sensory neuron stimulation was examined using cultured dorsal root ganglion (DRG) neurons isolated from mice. DHT inhibits calcitonin gene-related peptide (CGRP) release from cultured DRG neurons. The non-steroidal androgen-receptor antagonist flutamide reversed DHT-induced inhibition of CGRP release. Dermal levels of IGF-I and IGF-I mRNA, and the number of IGF-I-positive fibroblasts around hair follicles were increased at 6h after CGRP administration. DHT administration for 3weeks decreased dermal levels of CGRP, IGF-I, and IGF-I mRNA in mice. Immunohistochemical expression of IGF-I and the number of proliferating cells in hair follicles were decreased and hair re-growth was inhibited in animals administered DHT. Co-administration of flutamide and CGRP reversed these changes induced by DHT administration. These observations suggest that DHT may decrease IGF-I production in dermal papillae by inhibiting sensory neuron stimulation through interaction with the androgen receptor, thereby inhibiting hair growth in mice. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Osthole inhibits inflammatory cytokine release through PPARα/γ-mediated mechanisms in LPS-stimulated 3T3-L1 adipocytes.

    PubMed

    Wang, Xiao-li; Shang, Xiang; Cui, Yan; Zhao, Xi; Zhang, Yan; Xie, Mei-lin

    2015-04-01

    Peroxisome proliferator-activated receptor (PPAR) α/γ may control inflammatory response by regulating the nuclear factor-kappa B (NF-κB). Osthole may be a dual agonist of PPARα/γ, but whether or not osthole may inhibit inflammatory cytokines in cultured 3T3-L1 adipocytes is unclear. We investigated the action of osthole and its potential mechanisms in lipopolysaccharide (LPS)-stimulated 3T3-L1 adipocytes. The 3T3-L1 adipocytes stimulated with LPS were cultured and treated with different concentrations of osthole. The inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cultured supernatants were detected by the enzyme-linked immunosorbent assay (ELISA) method, and the protein expressions of PPARα/γ and NF-κB p65 in adipocytes were detected by the Western blot method, respectively. Following treatment of adipocytes with osthole 0.1-1.6 μM, the TNF-α and IL-6 levels in cultured supernatants were decreased, and the NF-κB p65 protein expression in adipocytes was also decreased, while the PPARα/γ protein expressions were increased. After pretreatment of adipocytes with specific inhibitor(s) of PPARα and /or PPARγ, the inhibitory effects of osthole on TNF-α and IL-6 were decreased or almost cancelled, and the effects on NF-κB p65 protein expression also exhibited similar variations. Osthole could inhibit the TNF-α and IL-6 production in LPS-stimulated adipocytes, and its mechanism might be related to reduction of NF-κB expression via activation of PPARα/γ.

  3. Acute stimulation of brain mu opioid receptors inhibits glucose-stimulated insulin secretion via sympathetic innervation.

    PubMed

    Tudurí, Eva; Beiroa, Daniel; Stegbauer, Johannes; Fernø, Johan; López, Miguel; Diéguez, Carlos; Nogueiras, Rubén

    2016-11-01

    Pancreatic insulin-secreting β-cells express opioid receptors, whose activation by opioid peptides modulates hormone secretion. Opioid receptors are also expressed in multiple brain regions including the hypothalamus, where they play a role in feeding behavior and energy homeostasis, but their potential role in central regulation of glucose metabolism is unknown. Here, we investigate whether central opioid receptors participate in the regulation of insulin secretion and glucose homeostasis in vivo. C57BL/6J mice were acutely treated by intracerebroventricular (i.c.v.) injection with specific agonists for the three main opioid receptors, kappa (KOR), delta (DOR) and mu (MOR) opioid receptors: activation of KOR and DOR did not alter glucose tolerance, whereas activation of brain MOR with the specific agonist DAMGO blunted glucose-stimulated insulin secretion (GSIS), reduced insulin sensitivity, increased the expression of gluconeogenic genes in the liver and, consequently, impaired glucose tolerance. Pharmacological blockade of α2A-adrenergic receptors prevented DAMGO-induced glucose intolerance and gluconeogenesis. Accordingly, DAMGO failed to inhibit GSIS and to impair glucose tolerance in α2A-adrenoceptor knockout mice, indicating that the effects of central MOR activation on β-cells are mediated via sympathetic innervation. Our results show for the first time a new role of the central opioid system, specifically the MOR, in the regulation of insulin secretion and glucose metabolism. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Mechanism of bisphenol AF-induced progesterone inhibition in human chorionic gonadotrophin-stimulated mouse Leydig tumor cell line (mLTC-1) cells.

    PubMed

    Feng, Yixing; Shi, Jiachen; Jiao, Zhihao; Duan, Hejun; Shao, Bing

    2018-06-01

    Bisphenol AF (BPAF) has been shown to inhibit testicular steroidogenesis in male rats. However, the precise mechanisms related to the toxic effects of BPAF on reproduction remain poorly understood. In the present study, a mouse Leydig tumor cell line (mLTC-1) was used as a model to investigate the mechanism of steroidogenic inhibition and to identify the molecular target of BPAF. Levels of progesterone and the concentration of cyclic adenosine monophosphate (cAMP) in cells exposed to BPAF were detected, and expression of key genes and proteins in steroid biosynthesis was assessed. The results showed that BPAF exposure decreased human chorionic gonadotrophin (hCG)-stimulated progesterone production in a dose-dependent manner. The 24-h IC 50 (half maximal inhibitory concentration) value for BPAF regarding progesterone production was 70.2 µM. A dramatic decrease in cellular cAMP concentration was also observed. Furthermore, BPAF exposure inhibited expression of genes and proteins involved in cholesterol transport and progesterone biosynthesis. Conversely, the protein levels of steroidogenic acute regulatory protein (StAR) were not altered, and those of progesterone were still decreased upon 22R-hydroxycholesterol treatment of cells exposed to higher doses of BPAF. Together, these data indicate that BPAF exposure inhibits progesterone secretion in hCG-stimulated mLTC-1 cells by reducing expression of scavenger receptor class B type I (SR-B1) and cytochrome P450 (P450scc) due to the adverse effects of cAMP. However, StAR might not be the molecular target in this process. © 2018 Wiley Periodicals, Inc.

  5. Marine Bacterial Polysaccharide EPS11 Inhibits Cancer Cell Growth via Blocking Cell Adhesion and Stimulating Anoikis

    PubMed Central

    Cao, Ruobing; Jin, Weihua; Shan, Yeqi; Wang, Ju; Liu, Ge; Kuang, Shan

    2018-01-01

    Tumor cells that acquire metastatic potential have developed resistance to anoikis, a cell death process, after detachment from their primary site to the second organ. In this study, we investigated the molecular mechanisms of a novel marine bacterial polysaccharide EPS11 which exerts its cytotoxic effects through affecting cancer cell adhesion and anoikis. Firstly, we found that EPS11 could significantly affect cell proliferation and block cell adhesion in A549 cells. We further demonstrated that the expression of several cell adhesion associated proteins is downregulated and the filiform structures of cancer cells are destroyed after EPS11 treatment. Interestingly, the destruction of filiform structures in A549 cells by EPS11 is in a dose-dependent manner, and the inhibitory tendency is very consistent with that observed in the cell adhesion assay, which confirms that filiform structures play important roles in modulating cell adhesion. Moreover, we showed that EPS11 induces apoptosis of A549 cells through stimulating βIII-tubulin associated anoikis: (i) EPS11 inhibits the expression of βIII-tubulin in both transcription and translation levels; and (ii) EPS11 treatment dramatically decreases the phosphorylation of protein kinase B (PKB or AKT), a critical downstream effector of βIII-tubulin. Importantly, EPS11 evidently inhibits the growth of A549-derived tumor xenografts in vivo. Thus, our results suggest that EPS11 may be a potential candidate for human non-small cell lung carcinoma treatment via blocking filiform structure mediated adhesion and stimulating βIII-tubulin associated anoikis. PMID:29518055

  6. Tangeretin and its metabolite 4'-hydroxytetramethoxyflavone attenuate EGF-stimulated cell cycle progression in hepatocytes; role of inhibition at the level of mTOR/p70S6K.

    PubMed

    Cheng, Z; Surichan, S; Ruparelia, K; Arroo, R; Boarder, M R

    2011-04-01

    The mechanisms by which the dietary compound tangeretin has anticancer effects may include acting as a prodrug, forming an antiproliferative product in cancer cells. Here we show that tangeretin also inhibits cell cycle progression in hepatocytes and investigate the role of its primary metabolite 4'-hydroxy-5,6,7,8-tetramethoxyflavone (4'-OH-TMF) in this effect. We used epidermal growth factor (EGF)-stimulated rat hepatocytes, with [(3)H]-thymidine incorporation into DNA as an index of progression to S-phase of the cell cycle, and Western blots for phospho-proteins involved in the cell signalling cascade. Incubation of tangeretin with microsomes expressing CYP1A, or with hepatocytes, generated a primary product we identified as 4'-OH-TMF. Low micromolar concentrations of tangeretin or 4'-OH-TMF gave a concentration-dependent inhibition of EGF-stimulated progression to S-phase while having little effect on cell viability. To determine whether time for conversion of tangeretin to an active metabolite would enhance the inhibitory effect we used long pre-incubations; this reduced the inhibitory effect, in parallel with a reduction in the concentration of tangeretin. The EGF-stimulation of hepatocyte cell cycle progression requires signalling through Akt/mTOR/p70S6K kinase cascades. The tangeretin metabolite 4'-OH-TMF selectively inhibited S6K phosphorylation in the absence of significant inhibition of upstream Akt activity, suggesting an effect at the level of mTOR. Tangeretin and 4'-OH-TMF both inhibit cell cycle progression in primary hepatocytes. The inhibition of p70S6K phosphorylation by 4'-OH-TMF raises the possibility that inhibition of the mTOR pathway may contribute to the anticancer influence of a flavonoid-rich diet. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  7. The TF1-ATPase and ATPase activities of assembled alpha 3 beta 3 gamma, alpha 3 beta 3 gamma delta, and alpha 3 beta 3 gamma epsilon complexes are stimulated by low and inhibited by high concentrations of rhodamine 6G whereas the dye only inhibits the alpha 3 beta 3, and alpha 3 beta 3 delta complexes.

    PubMed

    Paik, S R; Yokoyama, K; Yoshida, M; Ohta, T; Kagawa, Y; Allison, W S

    1993-12-01

    The ATPase activity of the F1-ATPase from the thermophilic bacterium PS3 is stimulated at concentrations of rhodamine 6G up to about 10 microM where 70% stimulation is observed at 36 degrees C. Half maximal stimulation is observed at about 3 microM dye. At rhodamine 6G concentrations greater than 10 microM, ATPase activity declines with 50% inhibition observed at about 75 microM dye. The ATPase activities of the alpha 3 beta 3 gamma and alpha 3 beta 3 gamma delta complexes assembled from isolated subunits of TF1 expressed in E. coli deleted of the unc operon respond to increasing concentrations of rhodamine 6G nearly identically to the response of TF1. In contrast, the ATPase activities of the alpha 3 beta 3 and alpha 3 beta 3 delta complexes are only inhibited by rhodamine 6G with 50% inhibition observed, respectively, at 35 and 75 microM dye at 36 degrees C. The ATPase activity of TF1 is stimulated up to 4-fold by the neutral detergent, LDAO. In the presence of stimulating concentrations of LDAO, the ATPase activity of TF1 is no longer stimulated by rhodamine 6G, but rather, it is inhibited with 50% inhibition observed at about 30 microM dye at 30 degrees C. One interpretation of these results is that binding of rhodamine 6G to a high-affinity site on TF1 stimulates ATPase activity and unmasks a low-affinity, inhibitory site for the dye which is also exposed by LDAO.

  8. Transcranial Direct Current Stimulation of the Temporoparietal Junction and Inferior Frontal Cortex Improves Imitation-Inhibition and Perspective-Taking with no Effect on the Autism-Spectrum Quotient Score

    PubMed Central

    Nobusako, Satoshi; Nishi, Yuki; Nishi, Yuki; Shuto, Takashi; Asano, Daiki; Osumi, Michihiro; Morioka, Shu

    2017-01-01

    Lesions to brain regions such as the temporoparietal junction (TPJ) and inferior frontal cortex (IFC) are thought to cause autism-spectrum disorder (ASD). Previous studies indicated that transcranial direct current stimulation (tDCS) of the right TPJ improves social cognitive functions such as imitation-inhibition and perspective-taking. Although previous work shows that tDCS of the right IFC improves imitation-inhibition, its effects on perspective-taking have yet to be determined. In addition, the role of the TPJ and IFC in determining the Autism-Spectrum Quotient (AQ), which is a measure of autism spectrum traits, is still unclear. Thus, the current study performed tDCS on the right TPJ and the right IFC of healthy adults, and examined its effects on imitation-inhibition, perspective-taking and AQ scores. Based on previous studies, we hypothesized that anodal tDCS of the right IFC and right TPJ would improve imitation-inhibition, perspective-taking and the AQ score. Anodal tDCS of the right TPJ or IFC significantly decreased the interference effect in an imitation-inhibition task and the cost of perspective-taking in a perspective-taking task, in comparison to the sham stimulation control. These findings indicated that both the TPJ and the IFC play a role in imitation-inhibition and perspective-taking, i.e., control of self and other representations. However, anodal stimulation of the right TPJ and the right IFC did not alter participants’ AQ. This finding conflicts with results from previous brain imaging studies, which could be attributed to methodological differences such as variation in sex, age and ASD. Therefore, further research is necessary to determine the relationship between the TPJ and IFC, and the AQ. PMID:28536512

  9. Ex-vivo in-vitro inhibition of lipopolysaccharide stimulated tumor necrosis factor-alpha and interleukin-1 beta secretion in human whole blood by extractum urticae dioicae foliorum.

    PubMed

    Obertreis, B; Ruttkowski, T; Teucher, T; Behnke, B; Schmitz, H

    1996-04-01

    An extract of Urtica dioica folium (IDS 23, Rheuma-Hek), monographed positively for adjuvant therapy of rheumatic diseases and with known effects in partial inhibition of prostaglandin and leukotriene synthesis in vitro, was investigated with respect to effects of the extract on the lipopolysaccharide (LPS) stimulated secretion of proinflammatory cytokines in human whole blood of healthy volunteers. In the assay system used, LPS stimulated human whole blood showed a straight increase of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) secretion reaching maximum concentrations within 24 h following a plateau and slight decrease up to 65 h, respectively. The concentrations of these cytokines was strongly positively correlated with the number of monocytes/macrophages of each volunteer. TNF-alpha and IL-1 beta concentration after LPS stimulation was significantly reduced by simultaneously given IDS 23 in a strictly dose dependent manner. At time 24 h these cytokine concentrations were reduced by 50.8% and 99.7%, respectively, using the highest test IDS 23 assay concentration of 5 mg/ml (p < 0.001). After 65 h the corresponding inhibition was 38.9% and 99.9%, respectively (p < 0.001). On the other hand IDS 23 showed no inhibition but stimulated IL-6 secretion in absence of LPS alone. Simultaneously given LPS and IDS 23 resulted in no further increase. In contrast to described effects on arachidonic acid cascade in vitro, tested Urtica dioica phenol carbon acid derivates and flavonoides such as caffeic malic acid, caffeic acid, chlorogenic acid, quercetin and rutin did not influence LPS stimulated TNF-alpha, IL-1 beta and IL-6 secretion in tested concentrations up to 5 x 10(-5) mol/l. These further findings on the pharmacological mechanism of action of Urticae dioica folia may explain the positive effects of this extract in the treatment of rheumatic diseases.

  10. Emodin, an 11β-hydroxysteroid dehydrogenase type 1 inhibitor, regulates adipocyte function in vitro and exerts anti-diabetic effect in ob/ob mice

    PubMed Central

    Wang, Yue-jing; Huang, Su-ling; Feng, Ying; Ning, Meng-meng; Leng, Ying

    2012-01-01

    Aim: Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a potent and selective inhibitor of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) with the ability to ameliorate metabolic disorders in diet-induced obese mice. In the present study, we investigated the effects of emodin on adipocyte function and the underlying mechanisms in vitro, and its anti-diabetic effects in ob/ob mice. Methods: 3T3-L1 adipocytes were used for in vitro studies. 11β-HSD1A activity was evaluated with a scintillation proximity assay. The adipogenesis, glucose uptake, lipolysis and adiponectin secretion were investigated in 3T3-L1 adipocytes treated with emodin in the presence of active (corticosterone) or inactive glucocorticoid (11-dehydrocorticosterone). For in vivo studies, ob/ob mice were administered emodin (25 and 50 mg·kg−1·d−1, ip) for 26 d. On the last day of administration, the serum was collected and the mesenteric and perirenal fat were dissected for analyses. Results: Emodin inhibited the 11β-HSD1 activity in 3T3-L1 adipocytes in concentration- and time-dependent manners (the IC50 values were 7.237 and 4.204 μmol/L, respectively, after 1 and 24 h treatment. In 3T3-L1 adipocytes, emodin (30 μmol/L) suppressed 11-dehydrocorticosterone-induced adipogenesis without affecting corticosterone-induced adipogenesis; emodin (3 μmol/L) reduced 11-dehydrocorticosterone-stimulated lipolysis, but had no effect on corticosterone-induced lipolysis. Moreover, emodin (3 μmol/L) partly reversed the impaired insulin-stimulated glucose uptake and adiponectin secretion induced by 11-dehydrocorticosterone but not those induced by corticosterone. In ob/ob mice, long-term emodin administration decreased 11β-HSD1 activity in mesenteric adipose tissues, lowered non-fasting and fasting blood glucose levels, and improved glucose tolerance. Conclusion: Emodin improves the inactive glucocorticoid-induced adipose tissue dysfunction by selective inhibition on 11β-HSD1 in adipocyte in vitro

  11. PPARdelta inhibits IL-1beta-stimulated proliferation and migration of vascular smooth muscle cells via up-regulation of IL-1Ra.

    PubMed

    Kim, H J; Kim, M Y; Hwang, J S; Kim, H J; Lee, J H; Chang, K C; Kim, J-H; Han, C W; Kim, J-H; Seo, H G

    2010-06-01

    Activation of peroxisome proliferator-activated receptor (PPAR) delta by GW501516, a specific PPARdelta ligand, significantly inhibited interleukin (IL)-1beta-induced proliferation and migration of vascular smooth muscle cells (VSMCs). This effect of GW501516 was dependent on transforming growth factor-beta, and was mediated through the up-regulation of IL-1 receptor antagonist. The inhibitory effect of GW501516 on VSMC proliferation was associated with cell cycle arrest at the G1 to S phase transition, which was accompanied by the induction of p21 and p53 along with decreased cyclin-dependent kinase 4 expression. Inhibition of cell migration by GW501516 was associated with the down-regulation of matrix metalloproteinase (MMP)-2 and MMP-9 in IL-1beta-treated VSMCs. Inhibition of extracellular signal-regulated kinase significantly reduced the GW501516-mediated inhibition of IL-1beta-stimulated VSMC proliferation. These results suggest that PPARdelta plays an important role in the pathophysiology of diseases associated with the proliferation and migration of VSMCs.

  12. A preliminary transcranial magnetic stimulation study of cortical inhibition and excitability in high-functioning autism and Asperger disorder.

    PubMed

    Enticott, Peter G; Rinehart, Nicole J; Tonge, Bruce J; Bradshaw, John L; Fitzgerald, Paul B

    2010-08-01

    Controversy surrounds the distinction between high-functioning autism (HFA) and Asperger disorder, but motor abnormalities are associated features of both conditions. This study examined motor cortical inhibition and excitability in HFA and Asperger disorder using transcranial magnetic stimulation (TMS). Participants were diagnosed by experienced clinicians strictly according to DSM-IV criteria. Participants with HFA (nine males, two females; mean age 16y 8mo, SD 4y 5mo) or Asperger disorder (11 males, three females; mean age 19y 1mo, SD 4y 2mo) and neurotypical participants (eight males, three females; mean age 19y 0mo, SD 3y 1mo) were administered a paired-pulse TMS paradigm intended to assess motor cortical inhibition and excitability. Responses to TMS were recorded by electromyography. Cortical inhibition was significantly reduced in the HFA group compared with both the Asperger disorder (p<0.001) and neurotypical (p<0.001) groups, suggesting disruption of activity at gamma-aminobutyric acid A (GABA(A)) receptors. There was no group difference in cortical excitability. Cortical inhibition deficits may underlie motor dysfunction in autism, and perhaps even relate to specific clinical symptoms (e.g. repetitive behaviours). These findings provide novel evidence for a possible neurobiological dissociation between HFA and Asperger disorder based on GABAergic function.

  13. Effect of Electrical Current Stimulation on Pseudomonas Aeruginosa Growth

    NASA Astrophysics Data System (ADS)

    Alneami, Auns Q.; Khalil, Eman G.; Mohsien, Rana A.; Albeldawi, Ali F.

    2018-05-01

    The present study evaluates the effect of electrical current with different frequencies stimulation to kill pathogenic Pseudomonas aeruginosa (PA) bacteria in vitro using human safe level of electricity controlled by function generator. A wide range of frequencies has been used from 0.5 Hz-1.2 MHz to stimulate the bacteria at a voltage of 20 p-p volt for different periods of time (5 to 30) minutes. The culture of bacteria used Nickel, Nichrome, or Titanium electrode using agarose in phosphate buffer saline (PBS) and mixed with bacterial stock activated by trypticase soy broth (TSB). The results of frequencies between 0.5-1 KHz show the inhibition zone diameter of 20 mm in average at 30 minutes of stimulation. At frequencies between 3-60 KHz the inhibition zone diameter was only 10mm for 30 minutes of stimulation. While the average of inhibition zone diameter increased to more than 30mm for 30 minutes of stimulation at frequencies between 80-120 KHz. From this study we conclude that at specific frequency (resonance frequency) (frequencies between 0.5-1 KHz) there was relatively large inhibition zone because the inductive reactance effect is equal to the value of capacitive reactance effect (XC = XL). At frequencies over than 60 KHz, maximum inhibition zone noticed because the capacitance impedance becomes negligible (only the small resistivity of the bacterial internal organs).

  14. Juvenile hormone and insulin suppress lipolysis between periods of lactation during tsetse fly pregnancy

    PubMed Central

    Michalkova, Veronika; Mireji, Paul; Attardo, Geoffrey M.; Moulton, John K.; Wilson, Thomas G.; Aksoy, Serap

    2014-01-01

    Tsetse flies are viviparous insects that nurture a single intrauterine progeny per gonotrophic cycle. The developing larva is nourished by the lipid-rich, milk-like secretions from a modified female accessory gland (milk gland). An essential feature of the lactation process involves lipid mobilization for incorporation into the milk. In this study, we examined roles for juvenile hormone (JH) and insulin/IGF-like (IIS) signaling pathways during tsetse pregnancy. In particular, we examined the roles for these pathways in regulating lipid homeostasis during transitions between non-lactating (dry) and lactating periods. The dry period occurs over the course of oogenesis and embryogenesis, while the lactation period spans intrauterine larvigenesis. Genes involved in the JH and IIS pathways were upregulated during dry periods, correlating with lipid accumulation between bouts of lactation. RNAi suppression of Forkhead Box Sub Group O (FOXO) expression impaired lipolysis during tsetse lactation and reduced fecundity. Similar reduction of the JH receptor Methoprene tolerant (Met), but not its paralog germ cell expressed (gce), reduced lipid accumulation during dry periods, indicating functional divergence between Met and gce during tsetse reproduction. Reduced lipid levels following Met knockdown led to impaired fecundity due to inadequate fat reserves at the initiation of milk production. Both the application of the JH analog (JHA) methoprene and injection of insulin into lactating females increased stored lipids by suppressing lipolysis and reduced transcripts of lactation-specific genes, leading to elevated rates of larval abortion. To our knowledge, this study is the first to address the molecular physiology of JH and IIS in a viviparous insect, and specifically to provide a role for JH signaling through Met in the regulation of lipid metabolism. PMID:23499946

  15. Inhibition of muscarinic-stimulated polyphosphoinositide hydrolysis and Ca2+ mobilization in cat iris sphincter smooth muscle cells by cAMP-elevating agents.

    PubMed

    Ding, K H; Husain, S; Akhtar, R A; Isales, C M; Abdel-Latif, A A

    1997-09-01

    The effects of carbachol (CCh) on inositol 1,4,5-trisphosphate (IP3) production and intracellular calcium ([Ca2+]i) mobilization, and their regulation by cAMP-elevating agents were investigated in SV-40 transformed cat iris sphincter smooth muscle (SV-CISM-2) cells. CCh produced time- and dose-dependent increases in IP3 production; the t1/2 and EC50 values were 68 s and 0.5 microM, respectively. The muscarinic agonist provoked a transient increase in [Ca2+]i which reached maximum within 77 s, and increased [Ca2+]i mobilization in a concentration-dependent manner with an EC50 of 1.4 microM. Thapsigargin, a Ca(2+)-pump inhibitor, caused a rapid rise in [Ca2+]i and subsequent addition of CCh was without effect. Both CCh-induced IP3 production and CCh-induced [Ca2+]i mobilization were more potently antagonized by 4-DAMP, an M3 muscarinic receptor antagonist, than by pirenzepine, an M1 receptor antagonist, suggesting that both responses are mediated through the M3 receptor subtype. Treatment of the cells with U73122, a phospholipase C (PLC) inhibitor, resulted in a concentration-dependent decrease in both CCh-stimulated IP3 production and [Ca2+]i mobilization. These data indicate close correlation between enhanced IP3 production and [Ca2+]i mobilization in these smooth muscle cells and suggest that the CCh-stimulated increase in [Ca2+]i could be mediated through increased IP3 production. Isoproterenol (ISO) inhibited CCh-induced IP3 production (IC50 = 80 nM) and [Ca2+]i mobilization (IC50 = 0.17 microM) in a concentration-dependent manner. Microsomal fractions isolated from SV-CISM-2 cells contained phospholipase C (PLC) which was stimulated by CCh (10 microM) and GTP gamma S (0.1 microM). Pretreatment of the cells with ISO or forskolin, 5 microM each, produced membrane fractions in which CCh-stimulated PLC activity was significantly attenuated. Furthermore, when microsomal fractions isolated from SV-CISM-2 cells were phosphorylated with Protein kinase A (PKA), the CCh

  16. Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (SINETROL) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-phosphodiesterase (PDE).

    PubMed

    Dallas, Constantin; Gerbi, Alain; Tenca, Guillaume; Juchaux, Franck; Bernard, François-Xavier

    2008-10-01

    The present study investigated the lipolytic (break of fat stored) effect of a citrus-based polyphenolic dietary supplement (SINETROL) at human adipocytes (ex vivo), body fat (clinical) and biochemical levels (inhibition of phosphodiesterase). Free fatty acids (FFA) release was used as indicator of human adipocyte lipolysis and SINETROL activity has been compared with known lipolytic products (isoproterenol, theopylline and caffeine). SINETROL stimulated significantly the lipolytic activity in a range of 6 fold greater than the control. Moreover, SINETROL has 2.1 greater activity than guarana 12% caffeine while its content in caffeine is 3 times lower. Clinically, two groups of 10 volunteers with BMI relevant of overweight were compared during 4 and 12 weeks with 1.4 g/day SINETROL and placebo supplementation. In the SINETROL Group the body fat (%) decreased with a significant difference of 5.53% and 15.6% after 4 and 12 weeks, respectively, while the body weight (kg) decreased with a significant difference of 2.2 and 5.2 kg after 4 and 12 weeks, respectively. These observed effects are linked to SINETROL polyphenolic composition and its resulting synergistic activity. SINETROL is a potent inhibitor of cAMP-phosphodiesterase (PDE) (97%) compared to other purified compounds (cyanidin-3 glycoside, narangin, caffeine). These results suggest that SINETROL has a strong lipolytic effect mediated by cAMP-PDE inhibition. SINETROL may serve to prevent obesity by decreasing BMI.

  17. Morphometric analysis of high-intensity focused ultrasound-induced lipolysis on cadaveric abdominal and thigh skin.

    PubMed

    Lee, Sugun; Kim, Hee-Jin; Park, Hyun Jun; Kim, Hyoung Moon; Lee, So Hyun; Cho, Sung Bin

    2017-07-01

    Non-focused ultrasound and high-intensity focused ultrasound (HIFU) devices induce lipolysis by generating acoustic cavitation and coagulation necrosis in targeted tissues. We aimed to investigate the morphometric characteristics of immediate tissue reactions induced by 2 MHz, 13-mm focused HIFU via two-dimensional ultrasound images and histologic evaluation of cadaveric skin from the abdomen and thigh. Acoustic fields of a 2 MHz, 38-mm HIFU transducer were characterized by reconstruction of the fields using acoustic intensity measurement. Additionally, abdominal and thigh tissues from a fresh cadaver were treated with a HIFU device for a single, two, and three pulses at the pulse energy of 130 J/cm 2 and a penetration depth of 13 mm. Acoustic intensity measurement revealed characteristic focal zones of significant thermal injury at the depth of 38 mm. In both the abdomen and thigh tissue, round to oval ablative thermal injury zones (TIZs) were visualized in subcutaneous fat layers upon treatment with a single pulse of HIFU treatment. Two to three HIFU pulses generated larger and more remarkable ablative zones throughout subcutaneous fat layers. Finally, experimental treatment in a tumescent infiltration-like setting induced larger HIFU-induced TIZs of an oval or columnar shape, compared to non-tumescent settings. Although neither acoustic intensity measurement nor cadaveric tissue exactly reflects in vivo HIFU-induced reactions in human tissue, we believe that our data will help guide further in vivo studies in investigating the therapeutic efficacy and safety of HIFU-induced lipolysis.

  18. Long non-coding RNA NEAT1-modulated abnormal lipolysis via ATGL drives hepatocellular carcinoma proliferation.

    PubMed

    Liu, Xirui; Liang, Yingjian; Song, Ruipeng; Yang, Guangchao; Han, Jihua; Lan, Yaliang; Pan, Shangha; Zhu, Mingxi; Liu, Yao; Wang, Yan; Meng, Fanzheng; Cui, Yifeng; Wang, Jiabei; Zhang, Bo; Song, Xuan; Lu, Zhaoyang; Zheng, Tongsen; Liu, Lianxin

    2018-05-15

    Abnormal metabolism, including abnormal lipid metabolism, is a hallmark of cancer cells. Some studies have demonstrated that the lipogenic pathway might promote the development of hepatocellular carcinoma (HCC). However, the role of the lipolytic pathway in HCC has not been elucidated. We compared levels of adipose triglyceride lipase (ATGL) in human HCC and healthy liver tissues by real time PCR, western blot and immunohistochemistry. We measured diacylglycerol(DAG) and free fatty acid (FFA) levels in HCC cells driven by the NEAT1-ATGL axis and in HCC tissues. We also assessed the effects of ATGL, DAG, FFA, and NEAT1 on HCC cells proliferation in vitro and in an orthotopic xenograft HCC mouse model. We also performed a luciferase reporter assay to investigate the interaction between NEAT1/ATGL and miR-124-3p. We found that the lipolytic enzyme, ATGL is highly expressed in human HCC tissues and predicts poor prognosis. We also found that high levels of DAG and FFA are present in HCC tissues. Furthermore, the lncRNA-NEAT1 was found to modulate ATGL expression and disrupt lipolysis in HCC cells via ATGL. Notably, ATGL and its products, DAG and FFA, were shown to be responsible for NEAT1-mediated HCC cell growth. NEAT1 regulated ATGL expression by binding miR-124-3p. Additionally, NEAT1 knockdown attenuated HCC cell growth through miR-124-3p/ATGL/DAG+FFA/PPARα signaling. Our results reveal that NEAT1-modulates abnormal lipolysis via ATGL to drive HCC proliferation.

  19. Transcutaneous electrical nerve stimulation reduces pain, fatigue and hyperalgesia while restoring central inhibition in primary fibromyalgia.

    PubMed

    Dailey, Dana L; Rakel, Barbara A; Vance, Carol G T; Liebano, Richard E; Amrit, Anand S; Bush, Heather M; Lee, Kyoung S; Lee, Jennifer E; Sluka, Kathleen A

    2013-11-01

    Because transcutaneous electrical nerve stimulation (TENS) works by reducing central excitability and activating central inhibition pathways, we tested the hypothesis that TENS would reduce pain and fatigue and improve function and hyperalgesia in people with fibromyalgia who have enhanced central excitability and reduced inhibition. The current study used a double-blinded randomized, placebo-controlled cross-over design to test the effects of a single treatment of TENS with people with fibromyalgia. Three treatments were assessed in random order: active TENS, placebo TENS and no TENS. The following measures were assessed before and after each TENS treatment: pain and fatigue at rest and in movement; pressure pain thresholds, 6-m walk test, range of motion; 5-time sit-to-stand test, and single-leg stance. Conditioned pain modulation was completed at the end of testing. There was a significant decrease in pain and fatigue with movement for active TENS compared to placebo and no TENS. Pressure pain thresholds increased at the site of TENS (spine) and outside the site of TENS (leg) when compared to placebo TENS or no TENS. During active TENS, conditioned pain modulation was significantly stronger compared to placebo TENS and no TENS. No changes in functional tasks were observed with TENS. Thus, the current study suggests TENS has short-term efficacy in relieving symptoms of fibromyalgia while the stimulator is active. Future clinical trials should examine the effects of repeated daily delivery of TENS, similar to the way in which TENS is used clinically on pain, fatigue, function, and quality of life in individuals with fibromyalgia. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  20. BDA-410 Treatment Reduces Body Weight and Fat Content by Enhancing Lipolysis in Sedentary Senescent Mice.

    PubMed

    Pereyra, Andrea S; Wang, Zhong-Min; Messi, Maria Laura; Zhang, Tan; Wu, Hanzhi; Register, Thomas C; Forbes, Elizabeth; Devarie-Baez, Nelmi O; Files, Daniel Clark; Abba, Martin C; Furdui, Cristina; Delbono, Osvaldo

    2017-08-01

    Loss of muscle mass and force with age leads to fall risk, mobility impairment, and reduced quality of life. This article shows that BDA-410, a calpain inhibitor, induced loss of body weight and fat but not lean mass or skeletal muscle proteins in a cohort of sedentary 23-month-old mice. Food and water intake and locomotor activity were not modified, whereas BDA-410 treatment decreased intramyocellular lipid and perigonadal fat, increased serum nonesterified fatty acids, and upregulated the genes mediating lipolysis and oxidation, lean phenotype, muscle contraction, muscle transcription regulation, and oxidative stress response. This finding is consistent with our recent report that lipid accumulation in skeletal myofibers is significantly correlated with slower fiber-contraction kinetics and diminished power in obese older adult mice. A proteomic analysis and immunoblot showed downregulation of the phosphatase PPP1R12B, which increases phosphorylated myosin half-life and modulates the calcium sensitivity of the contractile apparatus. This study demonstrates that BDA-410 exerts a beneficial effect on skeletal muscle contractility through new, alternative mechanisms, including enhanced lipolysis, upregulation of "lean phenotype-related genes," downregulation of the PP1R12B phosphatase, and enhanced excitation-contraction coupling. This single compound holds promise for treating age-dependent decline in muscle composition and strength. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Nicotine inhibits collagen synthesis and alkaline phosphatase activity, but stimulates DNA synthesis in osteoblast-like cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ramp, W.K.; Lenz, L.G.; Galvin, R.J.

    1991-05-01

    Use of smokeless tobacco is associated with various oral lesions including periodontal damage and alveolar bone loss. This study was performed to test the effects of nicotine on bone-forming cells at concentrations that occur in the saliva of smokeless tobacco users. Confluent cultures of osteoblast-like cells isolated from chick embryo calvariae were incubated for 2 days with nicotine added to the culture medium (25-600 micrograms/ml). Nicotine inhibited alkaline phosphatase in the cell layer and released to the medium, whereas glycolysis (as indexed by lactate production) was unaffected or slightly elevated. The effects on medium and cell layer alkaline phosphatase weremore » concentration dependent with maximal inhibition occurring at 600 micrograms nicotine/ml. Nicotine essentially did not affect the noncollagenous protein content of the cell layer, but did inhibit collagen synthesis (hydroxylation of ({sup 3}H)proline and collagenase-digestible protein) at 100, 300, and 600 micrograms/ml. Release of ({sup 3}H)hydroxyproline to the medium was also decreased in a dose-dependent manner, as was the collagenase-digestible protein for both the medium and cell layer. In contrast, DNA synthesis (incorporation of ({sup 3}H)thymidine) was more than doubled by the alkaloid, whereas total DNA content was slightly inhibited at 600 micrograms/ml, suggesting stimulated cell turnover. Morphologic changes occurred in nicotine-treated cells including rounding up, detachment, and the occurrence of numerous large vacuoles. These results suggest that steps to reduce the salivary concentration of nicotine in smokeless tobacco users might diminish damaging effects of this product on alveolar bone.« less

  2. Prooxidant effects of the combination of green tea extract and sodium nitrite for accelerating lipolysis and lipid oxidation in pepperoni during storage.

    PubMed

    Lin, Yuhai; Huang, Ming; Zhou, Guanghong; Zou, Yufeng; Xu, Xinglian

    2011-01-01

    The individual and interactive effects of green tea (GT) extract and sodium nitrite (NT) on lipolysis and lipid oxidation were investigated in pepperoni during processing and storage (4 °C). Pepperoni was treated with GT at concentrations of 0.02%, 0.05%, 0.1%, 0.2%, 0.5%; and NT from 0.003% to 0.015% in increments of 0.003%; and a combination of 0.05% GT and 0.009% NT (GT/NT). The pH, color, residual nitrite, fatty acid (FA), and 2-thiobarbituric acid reactive substances (TBARS) values were measured. The results showed inhibitory effects on TBARS value were concentration dependent. The largest effect was at 0.05% for GT and 0.009% for NT. Adding 0.05% GT significantly decreased (P < 0.05) the TBARS values but did not affect color values during storage. NT (0.009%) was more effective than GT (0.05%) for maintaining lower TBARS values (P < 0.05). Total fatty acids were not affected by 0.05% GT and 0.009% NT treatments. However, adding GT/NT showed a significant prooxidant effect (P < 0.05) in pepperoni, which accelerated lipolysis and lipid oxidation significantly (P < 0.05) during storage, with depletion of nitrite. This suggests that adding GT and an appropriate amount of NT into pepperoni could promote lipolysis and lipid oxidation during storage, as compared to NT alone. When using GT extract as an antioxidant in industrial production of pepperoni, the interaction effect with NT should be considered, as it may lead to a prooxidant effect during refrigerated storage. © 2011 Institute of Food Technologists®

  3. Hormonal regulation of phosphatidylcholine synthesis by reversible modulation of cytidylyltransferase.

    PubMed Central

    Kelly, K L; Gutierrez, G; Martin, A

    1988-01-01

    The effect of both lipolytic and antilipolytic hormones on the turnover of phosphatidylcholine in freshly isolated rat adipocytes was investigated. Treatment of adipocytes with agonists such as glucagon or isoprenaline that stimulate lipolysis through a cyclic AMP-dependent mechanism caused an increase in the incorporation of [Me-3H]choline into phosphatidylcholine. Pulse-chase studies indicated that the stimulation was due to an increase in the conversion of choline into phosphatidylcholine, which was both time- and dose-dependent. The stimulatory effect of isoprenaline was inhibited in a dose-dependent manner by oxytocin or insulin. Oxytocin inhibited the incorporation of [Me-3H]choline into phosphatidylcholine in both the presence and the absence of isoprenaline, whereas in the absence of isoprenaline insulin increased the incorporation of [Me-3H]choline into phosphatidylcholine. The effects of isoprenaline, oxytocin and insulin on the incorporation of [3H]choline into phosphatidylcholine were paralleled by changes in the activity of CTP:phosphocholine cytidylyltransferase. PMID:2849424

  4. PCB-153 Shows Different Dynamics of Mobilisation from Differentiated Rat Adipocytes during Lipolysis in Comparison with PCB-28 and PCB-118

    PubMed Central

    Louis, Caroline; Tinant, Gilles; Mignolet, Eric; Thomé, Jean-Pierre; Debier, Cathy

    2014-01-01

    Background Polychlorinated biphenyls (PCBs) are persistent organic pollutants. Due to their lipophilic character, they are preferentially stored within the adipose tissue. During the mobilisation of lipids, PCBs might be released from adipocytes into the bloodstream. However, the mechanisms associated with the release of PCBs have been poorly studied. Several in vivo studies followed their dynamics of release but the complexity of the in vivo situation, which is characterised by a large range of pollutants, does not allow understanding precisely the behaviour of individual congeners. The present in vitro experiment studied the impact of (i) the number and position of chlorine atoms of PCBs on their release from adipocytes and (ii) the presence of other PCB congeners on the mobilisation rate of such molecules. Methodology/Principal Findings Differentiated rat adipocytes were used to compare the behaviour of PCB-28, -118 and -153. Cells were contaminated with the three congeners, alone or in cocktail, and a lipolysis was then induced with isoproterenol during 12 hours. Our data indicate that the three congeners were efficiently released from adipocytes and accumulated in the medium during the lipolysis. Interestingly, for a same level of cell lipids, PCB-153, a hexa-CB with two chlorine atoms in ortho-position, was mobilised slower than PCB-28, a tri-CB, and PCB-118, a penta-CB, which are both characterised by one chlorine atom in ortho-position. It suggests an impact of the chemical properties of pollutants on their mobilisation during periods of negative energy balance. Moreover, the mobilisation of PCB congeners, taken individually, did not seem to be influenced by the presence of other congeners within adipocytes. Conclusion/Significance These results not only highlight the obvious mobilisation of PCBs from adipocytes during lipolysis, in parallel to lipids, but also demonstrate that the structure of congeners defines their rate of release from adipocytes. PMID

  5. PCB-153 shows different dynamics of mobilisation from differentiated rat adipocytes during lipolysis in comparison with PCB-28 and PCB-118.

    PubMed

    Louis, Caroline; Tinant, Gilles; Mignolet, Eric; Thomé, Jean-Pierre; Debier, Cathy

    2014-01-01

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants. Due to their lipophilic character, they are preferentially stored within the adipose tissue. During the mobilisation of lipids, PCBs might be released from adipocytes into the bloodstream. However, the mechanisms associated with the release of PCBs have been poorly studied. Several in vivo studies followed their dynamics of release but the complexity of the in vivo situation, which is characterised by a large range of pollutants, does not allow understanding precisely the behaviour of individual congeners. The present in vitro experiment studied the impact of (i) the number and position of chlorine atoms of PCBs on their release from adipocytes and (ii) the presence of other PCB congeners on the mobilisation rate of such molecules. Differentiated rat adipocytes were used to compare the behaviour of PCB-28, -118 and -153. Cells were contaminated with the three congeners, alone or in cocktail, and a lipolysis was then induced with isoproterenol during 12 hours. Our data indicate that the three congeners were efficiently released from adipocytes and accumulated in the medium during the lipolysis. Interestingly, for a same level of cell lipids, PCB-153, a hexa-CB with two chlorine atoms in ortho-position, was mobilised slower than PCB-28, a tri-CB, and PCB-118, a penta-CB, which are both characterised by one chlorine atom in ortho-position. It suggests an impact of the chemical properties of pollutants on their mobilisation during periods of negative energy balance. Moreover, the mobilisation of PCB congeners, taken individually, did not seem to be influenced by the presence of other congeners within adipocytes. These results not only highlight the obvious mobilisation of PCBs from adipocytes during lipolysis, in parallel to lipids, but also demonstrate that the structure of congeners defines their rate of release from adipocytes.

  6. Colony stimulating factor 1 receptor inhibition delays recurrence of glioblastoma after radiation by altering myeloid cell recruitment and polarization

    PubMed Central

    Stafford, Jason H.; Hirai, Takahisa; Deng, Lei; Chernikova, Sophia B.; Urata, Kimiko; West, Brian L.; Brown, J. Martin

    2016-01-01

    Background Glioblastoma (GBM) may initially respond to treatment with ionizing radiation (IR), but the prognosis remains extremely poor because the tumors invariably recur. Using animal models, we previously showed that inhibiting stromal cell–derived factor 1 signaling can prevent or delay GBM recurrence by blocking IR-induced recruitment of myeloid cells, specifically monocytes that give rise to tumor-associated macrophages. The present study was aimed at determining if inhibiting colony stimulating factor 1 (CSF-1) signaling could be used as an alternative strategy to target pro-tumorigenic myeloid cells recruited to irradiated GBM. Methods To inhibit CSF-1 signaling in myeloid cells, we used PLX3397, a small molecule that potently inhibits the tyrosine kinase activity of the CSF-1 receptor (CSF-1R). Combined IR and PLX3397 therapy was compared with IR alone using 2 different human GBM intracranial xenograft models. Results GBM xenografts treated with IR upregulated CSF-1R ligand expression and increased the number of CD11b+ myeloid-derived cells in the tumors. Treatment with PLX3397 both depleted CD11b+ cells and potentiated the response of the intracranial tumors to IR. Median survival was significantly longer for mice receiving combined therapy versus IR alone. Analysis of myeloid cell differentiation markers indicated that CSF-1R inhibition prevented IR-recruited monocyte cells from differentiating into immunosuppressive, pro-angiogenic tumor-associated macrophages. Conclusion CSF-1R inhibition may be a promising strategy to improve GBM response to radiotherapy. PMID:26538619

  7. Inhibition of Gαs/cAMP Signaling Decreases TCR-Stimulated IL-2 transcription in CD4(+) T Helper Cells.

    PubMed

    Hynes, Thomas R; Yost, Evan A; Yost, Stacy M; Hartle, Cassandra M; Ott, Braden J; Berlot, Catherine H

    2015-07-06

    The role of cAMP in regulating T cell activation and function has been controversial. cAMP is generally known as an immunosuppressant, but it is also required for generating optimal immune responses. As the effect of cAMP is likely to depend on its cellular context, the current study investigated whether the mechanism of activation of Gαs and adenylyl cyclase influences their effect on T cell receptor (TCR)-stimulated interleukin-2 (IL-2) mRNA levels. The effect of blocking Gs-coupled receptor (GsPCR)-mediated Gs activation on TCR-stimulated IL-2 mRNA levels in CD4(+) T cells was compared with that of knocking down Gαs expression or inhibiting adenylyl cyclase activity. The effect of knocking down Gαs expression on TCR-stimulated cAMP accumulation was compared with that of blocking GsPCR signaling. ZM-241385, an antagonist to the Gs-coupled A2A adenosine receptor (A2AR), enhanced TCR-stimulated IL-2 mRNA levels in primary human CD4(+) T helper cells and in Jurkat T cells. A dominant negative Gαs construct, GαsDN3, also enhanced TCR-stimulated IL-2 mRNA levels. Similar to GsPCR antagonists, GαsDN3 blocked GsPCR-dependent activation of both Gαs and Gβγ. In contrast, Gαs siRNA and 2',5'-dideoxyadenosine (ddA), an adenylyl cyclase inhibitor, decreased TCR-stimulated IL-2 mRNA levels. Gαs siRNA, but not GαsDN3, decreased TCR-stimulated cAMP synthesis. Potentiation of IL-2 mRNA levels by ZM-241385 required at least two days of TCR stimulation, and addition of ddA after three days of TCR stimulation enhanced IL-2 mRNA levels. GsPCRs play an inhibitory role in the regulation of TCR-stimulated IL-2 mRNA levels whereas Gαs and cAMP can play a stimulatory one. Additionally, TCR-dependent activation of Gαs does not appear to involve GsPCRs. These results suggest that the context of Gαs/cAMP activation and the stage of T cell activation and differentiation determine the effect on TCR-stimulated IL-2 mRNA levels.

  8. Overexpression of cellular repressor of E1A-stimulated genes inhibits TNF-{alpha}-induced apoptosis via NF-{kappa}B in mesenchymal stem cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peng, Cheng-Fei; Cardiovascular Research Institute and Department of Cardiology, Shenyang Northern Hospital, Shenyang; Han, Ya-Ling, E-mail: hanyaling53@gmail.com

    2011-03-25

    Research highlights: {yields} CREG protected MSCs from tumor necrosis factor-{alpha} (TNF-{alpha}) induced apoptosis. {yields} CREG inhibits the phosphorylation of I{kappa}B{alpha} and prevents the activation of NF-{kappa}B. {yields} CREG inhibits NF-{kappa}B nuclear translocation and pro-apoptosis protein transcription. {yields} CREG anti-apoptotic effect involves inhibition of the death receptor pathway. {yields} p53 is downregulated by CREG via NF-{kappa}B pathway under TNF-{alpha} stimulation. -- Abstract: Bone marrow-derived mesenchymal stem cells (MSCs) show great potential for therapeutic repair after myocardial infarction. However, poor viability of transplanted MSCs in the ischemic heart has limited their use. Cellular repressor of E1A-stimulated genes (CREG) has been identified asmore » a potent inhibitor of apoptosis. This study therefore aimed to determine if rat bone marrow MSCs transfected with CREG-were able to effectively resist apoptosis induced by inflammatory mediators, and to demonstrate the mechanism of CREG action. Apoptosis was determined by flow cytometric and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assays. The pathways mediating these apoptotic effects were investigated by Western blotting. Overexpression of CREG markedly protected MSCs from tumor necrosis factor-{alpha} (TNF-{alpha}) induced apoptosis by 50% after 10 h, through inhibition of the death-receptor-mediated apoptotic pathway, leading to attenuation of caspase-8 and caspase-3. Moreover, CREG resisted the serine phosphorylation of I{kappa}B{alpha} and prevented the nuclear translocation of the transcription factor nuclear factor-{kappa}B (NF-{kappa}B) under TNF-{alpha} stimulation. Treatment of cells with the NF-{kappa}B inhibitor pyrrolidine dithiocarbamate (PDTC) significantly increased the transcription of pro-apoptosis proteins (p53 and Fas) by NF-{kappa}B, and attenuated the anti-apoptotic effects of CREG on MSCs. The results of this

  9. Inhibition of xanthine oxidase reduces oxidative stress and improves skeletal muscle function in response to electrically stimulated isometric contractions in aged mice

    PubMed Central

    Ryan, Michael J.; Jackson, Janna R.; Hao, Yanlei; Leonard, Stephen S.; Alway, Stephen E.

    2012-01-01

    Oxidative stress is a putative factor responsible for reducing function and increasing apoptotic signaling in skeletal muscle with aging. This study examined the contribution and functional significance of the xanthine oxidase enzyme as a potential source of oxidant production in aged skeletal muscle during repetitive in situ electrically stimulated isometric contractions. Xanthine oxidase activity was inhibited in young adult and aged mice via a subcutaneously placed time release (2.5 mg/day) allopurinol pellet, 7 days prior to the start of in situ electrically stimulated isometric contractions. Gastrocnemius muscles were electrically activated with 20 maximal contractions for three consecutive days. Xanthine oxidase activity was 65% greater in the gastrocnemius muscle of aged mice compared to young mice. Xanthine oxidase activity also increased after in situ electrically stimulated isometric contractions in muscles from both young (33%) and aged (28%) mice, relative to contralateral non-contracted muscles. Allopurinol attenuated the exercise-induced increase in oxidative stress, but it did not affect the elevated basal levels of oxidative stress that was associated with aging. In addition, inhibition of xanthine oxidase activity decreased caspase 3 activity, but it had no effect on other markers of mitochondrial associated apoptosis. Our results show that compared to control conditions, suppression of xanthine oxidase activity by allopurinol reduced xanthine oxidase activity, H2O2 levels, lipid peroxidation and caspase-3 activity, prevented the in situ electrically stimulated isometric contraction-induced loss of glutathione, prevented the increase of catalase and copper-zinc superoxide dismutase activities, and increased maximal isometric force in the plantar flexor muscles of aged mice after repetitive electrically evoked contractions. PMID:21530649

  10. Palmitic acid acutely inhibits acetylcholine- but not GLP-1-stimulated insulin secretion in mouse pancreatic islets

    PubMed Central

    Qin, Wei; Vinogradov, Sergei A.; Wilson, David F.; Matschinsky, Franz M.

    2010-01-01

    Fatty acids, acetylcholine, and GLP-1 enhance insulin secretion in a glucose-dependent manner. However, the interplay between glucose, fatty acids, and the neuroendocrine regulators of insulin secretion is not well understood. Therefore, we studied the acute effects of PA (alone or in combination with glucose, acetylcholine, or GLP-1) on isolated cultured mouse islets. Two different sets of experiments were designed. In one, a fixed concentration of 0.5 mM of PA bound to 0.15 mM BSA was used; in the other, a PA ramp from 0 to 0.5 mM was applied at a fixed albumin concentration of 0.15 mM so that the molar PA/BSA ratio changed within the physiological range. At a fixed concentration of 0.5 mM, PA markedly inhibited acetylcholine-stimulated insulin release, the rise of intracellular Ca2+, and enhancement of cAMP production but did not influence the effects of GLP-1 on these parameters of islet cell function. 2-ADB, an IP3 receptor inhibitor, reduced the effect of acetylcholine on insulin secretion and reversed the effect of PA on acetylcholine-stimulated insulin release. Islet perfusion for 35–40 min with 0.5 mM PA significantly reduced the calcium storage capacity of ER measured by the thapsigargin-induced Ca2+ release. Oxygen consumption due to low but not high glucose was reduced by PA. When a PA ramp from 0 to 0.5 mM was applied in the presence of 8 mM glucose, PA at concentrations as low as 50 μM significantly augmented glucose-stimulated insulin release and markedly reduced acetylcholine's effects on hormone secretion. We thus demonstrate that PA acutely reduces the total oxygen consumption response to glucose, glucose-dependent acetylcholine stimulation of insulin release, Ca2+, and cAMP metabolism, whereas GLP-1's actions on these parameters remain unaffected or potentiated. We speculate that acute emptying of the ER calcium by PA results in decreased glucose stimulation of respiration and acetylcholine potentiation of insulin secretion. PMID:20606076

  11. Proliferation of smooth muscle cells stimulated by Porphyromonas gingivalis is inhibited by apple polyphenol.

    PubMed

    Inaba, Hiroaki; Tagashira, Motoyuki; Kanda, Tomomasa; Amano, Atsuo

    2011-11-01

    Porphyromonas gingivalis (Pg) is thought to be involved in the progression of occlusive arterial lesions, whereas vascular smooth muscle cell (SMC) proliferation is considered to be involved in occlusive arterial disease. We previously showed that bacteremia caused by Pg infection induced proliferation of mouse aortic SMCs. Furthermore, human SMCs stimulated with human plasma incubated with Pg showed a marked transformation from the contractile to proliferative phenotype. In the present study, we examine the involvement of Pg gingipains and fimbriae in induction of the SMC transformation and proliferation, and effective inhibitors. Pg strains including gingipain- and fimbria-null mutants were incubated in human plasma, after which the bacteria were removed and the supernatants were added to cultured SMCs. To evaluate the effects of inhibitors, Pg organisms were incubated in plasma in the presence of apple polyphenol (AP), epigallocatechin gallate, KYT-1 (Arg-gingipain inhibitor), and KYT-36 (Lys-gingipain inhibitor). Plasma supernatants from wild-type and fimbria-mutant cultures markedly stimulated cellular proliferation, whereas those containing gingipain-null mutants showed negligible effects. SMC proliferation was also induced by plasma treated with trypsin. Furthermore, plasma supernatants cultured in the presence of KYT-1/KYT-36 and AP showed significant inhibitory effects on SMC proliferation, whereas cultures with epigallocatechin gallate did not. Our results suggest that Pg gingipains are involved in the induction of SMC transformation and proliferation, whereas this was inhibited by AP.

  12. Metabolic syndrome, hyperinsulinemia, and cancer.

    PubMed

    Hsu, Isabel R; Kim, Stella P; Kabir, Morvarid; Bergman, Richard N

    2007-09-01

    The term metabolic syndrome describes the association between obesity, insulin resistance, and the risk of several prominent chronic diseases, including cancer. The causal link between many of these components remains unexplained, however. What is clear are the events that precede the development of the syndrome itself. In animal models, a fat-supplemented diet causes 1) lipid deposition in adipose depots, 2) insulin resistance of liver and skeletal muscle, and 3) hyperinsulinemia. One hypothesis relating fat deposition and insulin resistance involves enhanced lipolysis in the visceral depot, which leads to an increase in free fatty acid (FFA) flux. Increased mass of stored lipid and insulin resistance of visceral adipocytes favors lipolysis. Additionally, hypersensitivity of visceral adipose cells to sympathetic nervous system stimulation leads to increased lipolysis in the obese state. However, little evidence is available for enhanced plasma FFA concentrations in the fasting state. We measured FFA concentrations over a 24-h day in obese animals and found that plasma FFAs are elevated in the middle of the night, peaking at 0300. Therefore, it is possible that nocturnal lipolysis increases exposure of liver and muscle to FFAs at night, thus causing insulin resistance, which may play a role in hyperinsulinemic compensation to insulin resistance. Nocturnal lipolysis secondary to sympathetic stimulation may not only cause insulin resistance but also be responsible for hyperinsulinemia by stimulating secretion and reducing clearance of insulin by the liver. The resulting syndrome-elevated nocturnal FFAs and elevated insulin-may synergize and increase the risk of some cancers. This possible scenario needs further study.

  13. Inhibition of inhibitor of kappaB kinases stimulates hepatic stellate cell apoptosis and accelerated recovery from rat liver fibrosis.

    PubMed

    Oakley, Fiona; Meso, Muriel; Iredale, John P; Green, Karen; Marek, Carylyn J; Zhou, Xiaoying; May, Michael J; Millward-Sadler, Harry; Wright, Matthew C; Mann, Derek A

    2005-01-01

    Resolution of liver fibrosis is associated with clearance of hepatic myofibroblasts by apoptosis; development of strategies that promote this process in a selective way is therefore important. The aim of this study was to determine whether the inhibitor of kappaB kinase suppressor sulfasalazine stimulates hepatic myofibroblast apoptosis and recovery from fibrosis. Hepatic myofibroblasts were generated by culture activation of rat and human hepatic stellate cells. Fibrosis was established in rat livers by chronic injury with carbon tetrachloride followed by recovery with or without sulfasalazine (150 mg/kg) treatment. Treatment of hepatic stellate cells with sulfasalazine (0.5-2.0 mmol/L) induced apoptosis of activated rat and human hepatic stellate cells. A single in vivo administration of sulfasalazine promoted accelerated recovery from fibrosis as assessed by improved fibrosis score, selective clearance of smooth muscle alpha-actin-positive myofibroblasts, reduced hepatic procollagen I and tissue inhibitor of metalloproteinase 1 messenger RNA expression, and increased matrix metalloproteinase 2 activity. Mechanistic studies showed that sulfasalazine selectively blocks nuclear factor-kappaB-dependent gene transcription, inhibits hepatic stellate cell expression of Gadd45beta, stimulates phosphorylation of Jun N-terminal kinase 2, and promotes apoptosis by a mechanism that is prevented by the Jun N-terminal kinase inhibitor SP600125. As further evidence for a survival role for the inhibitor of kappaB kinase/nuclear factor-kappaB pathway in activated hepatic stellate cells, a highly selective cell-permeable peptide inhibitor of kappaB kinase activation also stimulated hepatic stellate cell apoptosis via a Jun N-terminal kinase-dependent mechanism. Inhibition of the inhibitor of kappaB kinase/nuclear factor-kappaB pathway is sufficient to increase the rate at which activated hepatic stellate cells undergo apoptosis both in vitro and in vivo, and drugs that

  14. Juvenile hormone and insulin suppress lipolysis between periods of lactation during tsetse fly pregnancy.

    PubMed

    Baumann, Aaron A; Benoit, Joshua B; Michalkova, Veronika; Mireji, Paul; Attardo, Geoffrey M; Moulton, John K; Wilson, Thomas G; Aksoy, Serap

    2013-06-15

    Tsetse flies are viviparous insects that nurture a single intrauterine progeny per gonotrophic cycle. The developing larva is nourished by the lipid-rich, milk-like secretions from a modified female accessory gland (milk gland). An essential feature of the lactation process involves lipid mobilization for incorporation into the milk. In this study, we examined roles for juvenile hormone (JH) and insulin/IGF-like (IIS) signaling pathways during tsetse pregnancy. In particular, we examined the roles for these pathways in regulating lipid homeostasis during transitions between non-lactating (dry) and lactating periods. The dry period occurs over the course of oogenesis and embryogenesis, while the lactation period spans intrauterine larvigenesis. Genes involved in the JH and IIS pathways were upregulated during dry periods, correlating with lipid accumulation between bouts of lactation. RNAi suppression of Forkhead Box Sub Group O (FOXO) expression impaired lipolysis during tsetse lactation and reduced fecundity. Similar reduction of the JH receptor Methoprene tolerant (Met), but not its paralog germ cell expressed (gce), reduced lipid accumulation during dry periods, indicating functional divergence between Met and gce during tsetse reproduction. Reduced lipid levels following Met knockdown led to impaired fecundity due to inadequate fat reserves at the initiation of milk production. Both the application of the JH analog (JHA) methoprene and injection of insulin into lactating females increased stored lipids by suppressing lipolysis and reduced transcripts of lactation-specific genes, leading to elevated rates of larval abortion. To our knowledge, this study is the first to address the molecular physiology of JH and IIS in a viviparous insect, and specifically to provide a role for JH signaling through Met in the regulation of lipid metabolism during insect lactation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Inhibition of colony-stimulating-factor-1 signaling in vivo with the orally bioavailable cFMS kinase inhibitor GW2580.

    PubMed

    Conway, James G; McDonald, Brad; Parham, Janet; Keith, Barry; Rusnak, David W; Shaw, Eva; Jansen, Marilyn; Lin, Peiyuan; Payne, Alan; Crosby, Renae M; Johnson, Jennifer H; Frick, Lloyd; Lin, Min-Hwa Jasmine; Depee, Scott; Tadepalli, Sarva; Votta, Bart; James, Ian; Fuller, Karen; Chambers, Timothy J; Kull, Frederick C; Chamberlain, Stanley D; Hutchins, Jeff T

    2005-11-01

    Colony-stimulating-factor-1 (CSF-1) signaling through cFMS receptor kinase is increased in several diseases. To help investigate the role of cFMS kinase in disease, we identified GW2580, an orally bioavailable inhibitor of cFMS kinase. GW2580 completely inhibited human cFMS kinase in vitro at 0.06 microM and was inactive against 26 other kinases. GW2580 at 1 microM completely inhibited CSF-1-induced growth of mouse M-NFS-60 myeloid cells and human monocytes and completely inhibited bone degradation in cultures of human osteoclasts, rat calvaria, and rat fetal long bone. In contrast, GW2580 did not affect the growth of mouse NS0 lymphoblastoid cells, human endothelial cells, human fibroblasts, or five human tumor cell lines. GW2580 also did not affect lipopolysaccharide (LPS)-induced TNF, IL-6, and prostaglandin E2 production in freshly isolated human monocytes and mouse macrophages. After oral administration, GW2580 blocked the ability of exogenous CSF-1 to increase LPS-induced IL-6 production in mice, inhibited the growth of CSF-1-dependent M-NFS-60 tumor cells in the peritoneal cavity, and diminished the accumulation of macrophages in the peritoneal cavity after thioglycolate injection. Unexpectedly, GW2580 inhibited LPS-induced TNF production in mice, in contrast to effects on monocytes and macrophages in vitro. In conclusion, GW2580's selective inhibition of monocyte growth and bone degradation is consistent with cFMS kinase inhibition. The ability of GW2580 to chronically inhibit CSF-1 signaling through cFMS kinase in normal and tumor cells in vivo makes GW2580 a useful tool in assessing the role of cFMS kinase in normal and disease processes.

  16. PreSMA stimulation changes task-free functional connectivity in the fronto-basal-ganglia that correlates with response inhibition efficiency

    PubMed Central

    Xu, Benjamin; Sandrini, Marco; Wang, Wen-tung; Smith, Jason F.; Sarlls, Joelle E.; Awosika, Oluwole; Butman, John A.; Horwitz, Barry; Cohen, Leonardo G.

    2016-01-01

    Previous work using transcranial magnetic stimulation (TMS) demonstrated that the right pre-supplementary motor area (preSMA), a node in the fronto-basal-ganglia network, is critical for response inhibition. However, TMS influences interconnected regions, raising the possibility of a link between the preSMA activity and the functional connectivity within the network. To understand this relationship, we applied single-pulse TMS to the right preSMA during functional magnetic resonance imaging when the subjects were at rest to examine changes in neural activity and functional connectivity within the network in relation to the efficiency of response inhibition evaluated with a stop-signal task. The results showed that preSMA-TMS increased activation in the right inferior-frontal cortex (rIFC) and basal ganglia and modulated their task-free functional connectivity. Both the TMS-induced changes in the basal-ganglia activation and the functional connectivity between rIFC and left striatum, and of the overall network correlated with the efficiency of response inhibition and with the white-matter microstructure along the preSMA – rIFC pathway. These results suggest that the task-free functional and structural connectivity between the rIFCop and basal ganglia are critical to the efficiency of response inhibition. PMID:27144466

  17. Adipose Triglyceride Lipase Is Implicated in Fuel- and Non-fuel-stimulated Insulin Secretion*

    PubMed Central

    Peyot, Marie-Line; Guay, Claudiane; Latour, Martin G.; Lamontagne, Julien; Lussier, Roxane; Pineda, Marco; Ruderman, Neil B.; Haemmerle, Guenter; Zechner, Rudolf; Joly, Érik; Madiraju, S. R. Murthy; Poitout, Vincent; Prentki, Marc

    2009-01-01

    Reduced lipolysis in hormone-sensitive lipase-deficient mice is associated with impaired glucose-stimulated insulin secretion (GSIS), suggesting that endogenous β-cell lipid stores provide signaling molecules for insulin release. Measurements of lipolysis and triglyceride (TG) lipase activity in islets from HSL−/− mice indicated the presence of other TG lipase(s) in the β-cell. Using real time-quantitative PCR, adipose triglyceride lipase (ATGL) was found to be the most abundant TG lipase in rat islets and INS832/13 cells. To assess its role in insulin secretion, ATGL expression was decreased in INS832/13 cells (ATGL-knockdown (KD)) by small hairpin RNA. ATGL-KD increased the esterification of free fatty acid (FFA) into TG. ATGL-KD cells showed decreased glucose- or Gln + Leu-induced insulin release, as well as reduced response to KCl or palmitate at high, but not low, glucose. The KATP-independent/amplification pathway of GSIS was considerably reduced in ATGL-KD cells. ATGL−/− mice were hypoinsulinemic and hypoglycemic and showed decreased plasma TG and FFAs. A hyperglycemic clamp revealed increased insulin sensitivity and decreased GSIS and arginine-induced insulin secretion in ATGL−/− mice. Accordingly, isolated islets from ATGL−/− mice showed reduced insulin secretion in response to glucose, glucose + palmitate, and KCl. Islet TG content and FFA esterification into TG were increased by 2-fold in ATGL−/− islets, but glucose usage and oxidation were unaltered. The results demonstrate the importance of ATGL and intracellular lipid signaling for fuel- and non-fuel-induced insulin secretion. PMID:19389712

  18. Histophilus somni Stimulates Expression of Antiviral Proteins and Inhibits BRSV Replication in Bovine Respiratory Epithelial Cells

    PubMed Central

    Lin, C.; Agnes, J. T.; Behrens, N.; Tagawa, Y.; Gershwin, L. J.; Corbeil, L. B.

    2016-01-01

    Our previous studies showed that bovine respiratory syncytial virus (BRSV) followed by Histophilus somni causes more severe bovine respiratory disease and a more permeable alveolar barrier in vitro than either agent alone. However, microarray analysis revealed the treatment of bovine alveolar type 2 (BAT2) epithelial cells with H. somni concentrated culture supernatant (CCS) stimulated up-regulation of four antiviral protein genes as compared with BRSV infection or dual treatment. This suggested that inhibition of viral infection, rather than synergy, may occur if the bacterial infection occurred before the viral infection. Viperin (or radical S-adenosyl methionine domain containing 2—RSAD2) and ISG15 (IFN-stimulated gene 15—ubiquitin-like modifier) were most up-regulated. CCS dose and time course for up-regulation of viperin protein levels were determined in treated bovine turbinate (BT) upper respiratory cells and BAT2 lower respiratory cells by Western blotting. Treatment of BAT2 cells with H. somni culture supernatant before BRSV infection dramatically reduced viral replication as determined by qRT PCR, supporting the hypothesis that the bacterial infection may inhibit viral infection. Studies of the role of the two known H. somni cytotoxins showed that viperin protein expression was induced by endotoxin (lipooligosaccharide) but not by IbpA, which mediates alveolar permeability and H. somni invasion. A naturally occurring IbpA negative asymptomatic carrier strain of H. somni (129Pt) does not cause BAT2 cell retraction or permeability of alveolar cell monolayers, so lacks virulence in vitro. To investigate initial steps of pathogenesis, we showed that strain 129Pt attached to BT cells and induced a strong viperin response in vitro. Thus colonization of the bovine upper respiratory tract with an asymptomatic carrier strain lacking virulence may decrease viral infection and the subsequent enhancement of bacterial respiratory infection in vivo. PMID:26859677

  19. Histophilus somni Stimulates Expression of Antiviral Proteins and Inhibits BRSV Replication in Bovine Respiratory Epithelial Cells.

    PubMed

    Lin, C; Agnes, J T; Behrens, N; Shao, M; Tagawa, Y; Gershwin, L J; Corbeil, L B

    2016-01-01

    Our previous studies showed that bovine respiratory syncytial virus (BRSV) followed by Histophilus somni causes more severe bovine respiratory disease and a more permeable alveolar barrier in vitro than either agent alone. However, microarray analysis revealed the treatment of bovine alveolar type 2 (BAT2) epithelial cells with H. somni concentrated culture supernatant (CCS) stimulated up-regulation of four antiviral protein genes as compared with BRSV infection or dual treatment. This suggested that inhibition of viral infection, rather than synergy, may occur if the bacterial infection occurred before the viral infection. Viperin (or radical S-adenosyl methionine domain containing 2--RSAD2) and ISG15 (IFN-stimulated gene 15--ubiquitin-like modifier) were most up-regulated. CCS dose and time course for up-regulation of viperin protein levels were determined in treated bovine turbinate (BT) upper respiratory cells and BAT2 lower respiratory cells by Western blotting. Treatment of BAT2 cells with H. somni culture supernatant before BRSV infection dramatically reduced viral replication as determined by qRT PCR, supporting the hypothesis that the bacterial infection may inhibit viral infection. Studies of the role of the two known H. somni cytotoxins showed that viperin protein expression was induced by endotoxin (lipooligosaccharide) but not by IbpA, which mediates alveolar permeability and H. somni invasion. A naturally occurring IbpA negative asymptomatic carrier strain of H. somni (129Pt) does not cause BAT2 cell retraction or permeability of alveolar cell monolayers, so lacks virulence in vitro. To investigate initial steps of pathogenesis, we showed that strain 129Pt attached to BT cells and induced a strong viperin response in vitro. Thus colonization of the bovine upper respiratory tract with an asymptomatic carrier strain lacking virulence may decrease viral infection and the subsequent enhancement of bacterial respiratory infection in vivo.

  20. Plasticity of cortical inhibition in dystonia is impaired after motor learning and Paired-Associative Stimulation

    PubMed Central

    Meunier, Sabine; Russmann, Heike; Shamim, Ejaz; Lamy, Jean-Charles; Hallett, Mark

    2012-01-01

    Summary Artificial induction of plasticity by paired associative stimulation (PAS) in healthy subjects (HV) demonstrates Hebbian-like plasticity in selected inhibitory networks as well as excitatory ones. In a group of 17 patients with focal hand dystonia and a group of 19 HV, we evaluated how PAS and the learning of a simple motor task influence the circuits supporting long interval intracortical inhibition (LICI, reflecting activity of GABAB interneurons) and long latency afferent inhibition (LAI, reflecting activity of somatosensory inputs to the motor cortex). In HV, PAS and motor learning induced LTP-like plasticity of excitatory networks and a lasting decrease of LAI and LICI in the motor representation of the targeted or trained muscle. The better the motor performance, the larger was the decrease of LAI. Although motor performance in the patient group was similar to that of the control group, LAI did not decrease during the motor learning as it did in the control group. In contrast, LICI was normally modulated. In patients the results after PAS did not match those obtained after motor learning: LAI was paradoxically increased and LICI did not exhibit any change. In the normal situation, decreased excitability in inhibitory circuits after induction of LTP-like plasticity may help to shape the cortical maps according to the new sensorimotor task. In patients, the abnormal or absent modulation of afferent and intracortical long-interval inhibition might indicate maladaptive plasticity that possibly contributes to the difficulty that they have to learn a new sensorimotor task.“ PMID:22429246

  1. Red (660 nm) or near-infrared (810 nm) photobiomodulation stimulates, while blue (415 nm), green (540 nm) light inhibits proliferation in human adipose-derived stem cells.

    PubMed

    Wang, Yuguang; Huang, Ying-Ying; Wang, Yong; Lyu, Peijun; Hamblin, Michael R

    2017-08-10

    We previously showed that blue (415 nm) and green (540 nm) wavelengths were more effective in stimulating osteoblast differentiation of human adipose-derived stem cells (hASC), compared to red (660 nm) and near-infrared (NIR, 810 nm). Intracellular calcium was higher after blue/green, and could be inhibited by the ion channel blocker, capsazepine. In the present study we asked what was the effect of these four wavelengths on proliferation of the hASC? When cultured in proliferation medium there was a clear difference between blue/green which inhibited proliferation and red/NIR which stimulated proliferation, all at 3 J/cm 2 . Blue/green reduced cellular ATP, while red/NIR increased ATP in a biphasic manner. Blue/green produced a bigger increase in intracellular calcium and reactive oxygen species (ROS). Blue/green reduced mitochondrial membrane potential (MMP) and lowered intracellular pH, while red/NIR had the opposite effect. Transient receptor potential vanilloid 1 (TRPV1) ion channel was expressed in hADSC, and the TRPV1 ligand capsaicin (5uM) stimulated proliferation, which could be abrogated by capsazepine. The inhibition of proliferation caused by blue/green could also be abrogated by capsazepine, and by the antioxidant, N-acetylcysteine. The data suggest that blue/green light inhibits proliferation by activating TRPV1, and increasing calcium and ROS.

  2. Solubilisation of poorly water-soluble drugs during in vitro lipolysis of medium- and long-chain triacylglycerols.

    PubMed

    Christensen, Janne Ørskov; Schultz, Kirsten; Mollgaard, Birgitte; Kristensen, Henning Gjelstrup; Mullertz, Anette

    2004-11-01

    The partitioning of poorly soluble drugs into an aqueous micellar phase was exploited using an in vitro lipid digestion model, simulating the events taking place during digestion of acylglycerols in the duodenum. The aqueous micellar phase was isolated after ultracentrifugation of samples obtained at different degrees of triacylglycerol hydrolysis. Flupentixol, 1'-[4-[1-(4-fluorophenyl)-1-H-indol-3-yl]-1-butyl]spiro[iso-benzofuran-1(3H), 4' piperidine] (LU 28-179) and probucol were studied. The effect of the alkyl chain length of the triacylglycerol was studied using a medium-chain triacylglycerol (MCT) and a long-chain triacylglycerol (LCT), respectively. In general, an oil solution was used as the lipid source in the model. Samples were analysed in regard to micellar size, lipid composition and drug concentration. During lipolysis, the content of lipolytic products in the aqueous micellar phase increased. The micellar size (R(H) approximately 3 nm) only increased when long-chain lipolytic products were incorporated in the mixed micelles (R(H) approximately 7.8 nm). Flupentixol was quickly transferred to the mixed micelles due to high solubility in this phase (100% released). A tendency towards higher solubilisation of LU 28-179, when it was administered in the LCT (approximately 24% released) compared to when it was administered in the MCT (approximately 15% released) at 70% hydrolysis, and a lagphase was observed. There was no difference in the solubilisation of probucol using MCT or LCT ( approximately 20% released), respectively. Differences in the physicochemical properties of the drugs resulted in differences in their distribution between the phases arising during lipolysis.

  3. Expression of CD73/ecto-5'-nucleotidase on human gingival fibroblasts and contribution to the inhibition of interleukin-1alpha-induced granulocyte-macrophage colony stimulating factor production.

    PubMed

    Nemoto, Eiji; Kunii, Ryotaro; Tada, Hiroyuki; Tsubahara, Taisuke; Ishihata, Hiroshi; Shimauchi, Hidetoshi

    2004-02-01

    CD73/5'-nucleotidase (5'-NT) is an ectoenzyme that participates in immune/inflammatory reactions. We examined the possible expression of CD73/5'-NT on human gingival fibroblasts (hGF), which are important to the immune/inflammatory system in periodontal tissue. We demonstrated that CD73/5'-NT was expressed on hGF by flow cytometry. We found that pre-treatment of hGF with 5'-AMP induced marked inhibition of granulocyte-macrophage colony-stimulating factor (GM-CSF) production from hGF upon stimulation with interleukin-1alpha (IL-1alpha) by enzyme-linked immunosorbent assay (ELISA). A specific inhibitor of 5'-NT, adenosine 5'-[alpha,beta-methylene] diphosphate blocked the inhibition of GM-CSF production, suggesting that adenosine converted from 5'-AMP acts on the inhibitory effects. The GM-CSF inhibition suggested that A3 receptor might be involved. The rank order of agonists was found to be (N6-benzyl-5'-N-ethylcarboxamidoadenosine) A3 receptor agonist > or = (2-chloroadenosine) non-selective agonist > (CGS-21680) A2A receptor agonist > adenosine > or = (N6-cyclohexyladenosine) A1 agonist. Further support for the main role of A3 receptor was the binding A3 antagonist [9-chloro-2-(2-furanyl)-5-([phenylacetyl]amino)[1,2,4]-triazolo[1,5-c]quinazdine] reversed the effect of adenosine, but no significant reverse was observed by A1 (1,3-dipropyl-8-cyclopentylxanthine), A2 [3,7-dimethyl-1-(2-propargyl)xanthine], A2A[8-(3-chlorostyryl)caffeine], and A2B (alloxazine) antagonists. The CD73/5'-NT expression was increased upon stimulation with gamma-interferon, but not other stimulants such as tumor necrosis factor-alpha, IL-4, lipopolysaccharide from Porphyromonas gingivalis and Escherichia coli, and fimbriae from P. gingivalis, and this increase was correlated with the enhanced GM-CSF inhibition by 5'-AMP but not adenosine. These findings suggested that CD73/5'-NT on hGF exerts an anti-inflammatory effects in periodontal disease by conversion from 5'-AMP to adenosine.

  4. Palmitic acid follows a different metabolic pathway than oleic acid in human skeletal muscle cells; lower lipolysis rate despite an increased level of adipose triglyceride lipase.

    PubMed

    Bakke, Siril S; Moro, Cedric; Nikolić, Nataša; Hessvik, Nina P; Badin, Pierre-Marie; Lauvhaug, Line; Fredriksson, Katarina; Hesselink, Matthijs K C; Boekschoten, Mark V; Kersten, Sander; Gaster, Michael; Thoresen, G Hege; Rustan, Arild C

    2012-10-01

    Development of insulin resistance is positively associated with dietary saturated fatty acids and negatively associated with monounsaturated fatty acids. To clarify aspects of this difference we have compared the metabolism of oleic (OA, monounsaturated) and palmitic acids (PA, saturated) in human myotubes. Human myotubes were treated with 100μM OA or PA and the metabolism of [(14)C]-labeled fatty acid was studied. We observed that PA had a lower lipolysis rate than OA, despite a more than two-fold higher protein level of adipose triglyceride lipase after 24h incubation with PA. PA was less incorporated into triacylglycerol and more incorporated into phospholipids after 24h. Supporting this, incubation with compounds modifying lipolysis and reesterification pathways suggested a less influenced PA than OA metabolism. In addition, PA showed a lower accumulation than OA, though PA was oxidized to a relatively higher extent than OA. Gene set enrichment analysis revealed that 24h of PA treatment upregulated lipogenesis and fatty acid β-oxidation and downregulated oxidative phosphorylation compared to OA. The differences in lipid accumulation and lipolysis between OA and PA were eliminated in combination with eicosapentaenoic acid (polyunsaturated fatty acid). In conclusion, this study reveals that the two most abundant fatty acids in our diet are partitioned toward different metabolic pathways in muscle cells, and this may be relevant to understand the link between dietary fat and skeletal muscle insulin resistance. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Plasmids encoding PKI(1-31), a specific inhibitor of cAMP-stimulated gene expression, inhibit the basal transcriptional activity of some but not all cAMP-regulated DNA response elements in JEG-3 cells.

    PubMed

    Grove, J R; Deutsch, P J; Price, D J; Habener, J F; Avruch, J

    1989-11-25

    Plasmids that encode a bioactive amino-terminal fragment of the heat-stable inhibitor of the cAMP-dependent protein kinase, PKI(1-31), were employed to characterize the role of this protein kinase in the control of transcriptional activity mediated by three DNA regulatory elements in the JEG-3 human placental cell line. The 5'-flanking sequence of the human collagenase gene contains the heptameric sequence, 5'-TGAGTCA-3', previously identified as a "phorbol ester" response element. Reporter genes containing either the intact 1.2-kilobase 5'-flanking sequence from the human collagenase gene or just the 7-base pair (bp) response element, when coupled to an enhancerless promoter, each exhibit both cAMP and phorbol ester-stimulated expression in JEG-3 cells. Cotransfection of either construct with plasmids encoding PKI(1-31) inhibits cAMP-stimulated but not basal- or phorbol ester-stimulated expression. Pretreatment of cells with phorbol ester for 1 or 2 days abrogates completely the response to rechallenge with phorbol ester but does not alter the basal expression of either construct; cAMP-stimulated expression, while modestly inhibited, remains vigorous. The 5'-flanking sequence of the human chorionic gonadotropin-alpha subunit (HCG alpha) gene has two copies of the sequence, 5'-TGACGTCA-3', contained in directly adjacent identical 18-bp segments, previously identified as a cAMP-response element. Reporter genes containing either the intact 1.5 kilobase of 5'-flanking sequence from the HCG alpha gene, or just the 36-bp tandem repeat cAMP response element, when coupled to an enhancerless promoter, both exhibit a vigorous cAMP stimulation of expression but no response to phorbol ester in JEG-3 cells. Cotransfection with plasmids encoding PKI(1-31) inhibits both basal and cAMP-stimulated expression in a parallel fashion. The 5'-flanking sequence of the human enkephalin gene mediates cAMP-stimulated expression of reporter genes in both JEG-3 and CV-1 cells. Plasmids

  6. Anodal Direct Current Stimulation of the Cerebellum Reduces Cerebellar Brain Inhibition but Does Not Influence Afferent Input from the Hand or Face in Healthy Adults.

    PubMed

    Doeltgen, Sebastian H; Young, Jessica; Bradnam, Lynley V

    2016-08-01

    The cerebellum controls descending motor commands by outputs to primary motor cortex (M1) and the brainstem in response to sensory feedback. The cerebellum may also modulate afferent input en route to M1 and the brainstem. The objective of this study is to determine if anodal transcranial direct current stimulation (tDCS) to the cerebellum influences cerebellar brain inhibition (CBI), short afferent inhibition (SAI) and trigeminal reflexes (TRs) in healthy adults. Data from two studies evaluating effects of cerebellar anodal and sham tDCS are presented. The first study used a twin coil transcranial magnetic stimulation (TMS) protocol to investigate CBI and combined TMS and cutaneous stimulation of the digit to assess SAI. The second study evaluated effects on trigemino-cervical and trigemino-masseter reflexes using peripheral nerve stimulation of the face. Fourteen right-handed healthy adults participated in experiment 1. CBI was observed at baseline and was reduced by anodal cerebellar DCS only (P < 0.01). There was SAI at interstimulus intervals of 25 and 30 ms at baseline (both P < 0.0001), but cerebellar tDCS had no effect. Thirteen right-handed healthy adults participated in experiment 2. Inhibitory reflexes were evoked in the ipsilateral masseter and sternocleidomastoid muscles. There was no effect of cerebellar DCS on either reflex. Anodal DCS reduced CBI but did not change SAI or TRs in healthy adults. These results require confirmation in individuals with neurological impairment.

  7. The effect of stimulation interval on plasticity following repeated blocks of intermittent theta burst stimulation.

    PubMed

    Tse, Nga Yan; Goldsworthy, Mitchell R; Ridding, Michael C; Coxon, James P; Fitzgerald, Paul B; Fornito, Alex; Rogasch, Nigel C

    2018-06-04

    This study assessed the effect of interval duration on the direction and magnitude of changes in cortical excitability and inhibition when applying repeated blocks of intermittent theta burst stimulation (iTBS) over motor cortex. 15 participants received three different iTBS conditions on separate days: single iTBS; repeated iTBS with a 5 minute interval (iTBS-5-iTBS); and with a 15 minute interval (iTBS-15-iTBS). Changes in cortical excitability and short-interval cortical inhibition (SICI) were assessed via motor-evoked potentials (MEPs) before and up to 60 mins following stimulation. iTBS-15-iTBS increased MEP amplitude for up to 60 mins post stimulation, whereas iTBS-5-iTBS decreased MEP amplitude. In contrast, MEP amplitude was not altered by single iTBS. Despite the group level findings, only 53% of individuals showed facilitated MEPs following iTBS-15-iTBS, and only 40% inhibited MEPs following iTBS-5-iTBS. Modulation of SICI did not differ between conditions. These results suggest interval duration between spaced iTBS plays an important role in determining the direction of plasticity on excitatory, but not inhibitory circuits in human motor cortex. While repeated iTBS can increase the magnitude of MEP facilitation/inhibition in some individuals compared to single iTBS, the response to repeated iTBS appears variable between individuals in this small sample.

  8. The Subtle Balance between Lipolysis and Lipogenesis: A Critical Point in Metabolic Homeostasis.

    PubMed

    Saponaro, Chiara; Gaggini, Melania; Carli, Fabrizia; Gastaldelli, Amalia

    2015-11-13

    Excessive accumulation of lipids can lead to lipotoxicity, cell dysfunction and alteration in metabolic pathways, both in adipose tissue and peripheral organs, like liver, heart, pancreas and muscle. This is now a recognized risk factor for the development of metabolic disorders, such as obesity, diabetes, fatty liver disease (NAFLD), cardiovascular diseases (CVD) and hepatocellular carcinoma (HCC). The causes for lipotoxicity are not only a high fat diet but also excessive lipolysis, adipogenesis and adipose tissue insulin resistance. The aims of this review are to investigate the subtle balances that underlie lipolytic, lipogenic and oxidative pathways, to evaluate critical points and the complexities of these processes and to better understand which are the metabolic derangements resulting from their imbalance, such as type 2 diabetes and non alcoholic fatty liver disease.

  9. Inhibition of glycogen-synthase kinase 3 stimulates glycogen synthase and glucose transport by distinct mechanisms in 3T3-L1 adipocytes.

    PubMed

    Oreña, S J; Torchia, A J; Garofalo, R S

    2000-05-26

    The role of glycogen-synthase kinase 3 (GSK3) in insulin-stimulated glucose transport and glycogen synthase activation was investigated in 3T3-L1 adipocytes. GSK3 protein was clearly present in adipocytes and was found to be more abundant than in muscle and liver cell lines. The selective GSK3 inhibitor, LiCl, stimulated glucose transport and glycogen synthase activity (20 and 65%, respectively, of the maximal (1 microm) insulin response) and potentiated the responses to a submaximal concentration (1 nm) of insulin. LiCl- and insulin-stimulated glucose transport were abolished by the phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, wortmannin; however, LiCl stimulation of glycogen synthase was not. In contrast to the rapid stimulation of glucose transport by insulin, transport stimulated by LiCl increased gradually over 3-5 h reaching 40% of the maximal insulin-stimulated level. Both LiCl- and insulin-stimulated glycogen synthase activity were maximal at 25 min. However, insulin-stimulated glycogen synthase activity returned to basal after 2 h, coincident with reactivation of GSK3. After a 2-h exposure to insulin, glycogen synthase was refractory to restimulation with insulin, indicating selective desensitization of this pathway. However, LiCl could partially stimulate glycogen synthase in desensitized cells. Furthermore, coincubation with LiCl during the 2 h exposure to insulin completely blocked desensitization of glycogen synthase activity. In summary, inhibition of GSK3 by LiCl: 1) stimulated glycogen synthase activity directly and independently of PI3-kinase, 2) stimulated glucose transport at a point upstream of PI3-kinase, 3) stimulated glycogen synthase activity in desensitized cells, and 4) prevented desensitization of glycogen synthase due to chronic insulin treatment. These data are consistent with GSK3 playing a central role in the regulation of glycogen synthase activity and a contributing factor in the regulation of glucose transport in 3T3-L1

  10. A synthetic diosgenin primary amine derivative attenuates LPS-stimulated inflammation via inhibition of NF-κB and JNK MAPK signaling in microglial BV2 cells.

    PubMed

    Cai, Bangrong; Seong, Kyung-Joo; Bae, Sun-Woong; Chun, Changju; Kim, Won-Jae; Jung, Ji-Yeon

    2018-06-08

    Diosgenin, a precursor of steroid hormones in plants, is known to exhibit diverse pharmacological activities including anti-inflammatory properties. In this study, (3β, 25R)‑spirost‑5‑en‑3‑oxyl (2‑((2((2‑aminoethyl)amino)ethyl)amino)ethyl) carbamate (DGP), a new synthetic diosgenin derivative incorporating primary amine was used to investigate its anti-inflammatory effects and underlying mechanisms of action in lipopolysaccharide (LPS)-stimulated microglial BV2 cells. Pretreatment with DGP resulted in significant inhibition of nitric oxide (NO) synthesis, and down-regulation of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated microglial BV2 cells. In addition, DGP decreased the production of reactive oxygen species (ROS) and pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α). The inhibitory effects of DGP on these inflammatory mediators in LPS-stimulated microglial BV2 cells were regulated by NF-κB signaling through blocking p65 nuclear translocation and NF-κB p65/DNA binding activity. DGP also blocked the phosphorylation of c-Jun amino-terminal kinase (JNK), but not p38 kinase or extracellular signal-regulated kinases (ERK). The NF-κB inhibitor JSH-23 and JNK-specific inhibitor SP600125 significantly decreased NO production and IL-6 release in LPS-stimulated BV2 cells, respectively. The overall results demonstrate that DGP has anti-inflammatory effects on LPS-stimulated BV2 cells via inhibition of NF-κB and JNK activation, suggesting that DGP is a potential prophylactic agent in various neurodegenerative disorders. Copyright © 2018. Published by Elsevier B.V.

  11. Fisetin inhibits IL-31 production in stimulated human mast cells: Possibilities of fisetin being exploited to treat histamine-independent pruritus.

    PubMed

    Che, Denis Nchang; Cho, Byoung Ok; Shin, Jae Young; Kang, Hyun Ju; Kim, Young-Soo; Jang, Seon Il

    2018-05-15

    Interleukin-31 (IL-31) is a recently discovered cytokine that is tightly linked to the pathogenesis of pruritus seen in atopic dermatitis. Flavonoids, like fisetin, are naturally occurring molecules with antioxidant, cytoprotective, and anti-inflammatory actions. the present study sought to investigate whether fisetin modulates IL-31 and histamine release in human mast cells (HMC-1). HMC-1 cells were pretreated with fisetin at various doses and stimulated with phorbol-12-myristate 13-acetate and calcium ionophore A23187 (PI) for different time intervals. We evaluated IL-31 production and histamine release and signaling mechanism of the action of fisetin on IL-31 production. We also investigated the effects of fisetin on scratching behaviors in mice. Fisetin decreased PI-stimulated mRNA expression and production of IL-31 in HMC-1 cells. Fisetin inhibited PI-induced phosphorylation of mitogen-activated protein kinases that further suppressed nuclear factor (NF-κB) activation and translocation to the nucleus through the inhibition of IκB-α phosphorylation. Fisetin also prevented mast cell release of histamine in HMC-1 cells. Mice in-vivo studies show that fisetin reduced scratching behaviors in mice. These pharmacological actions of fisetin provide new suggestions that fisetin can be of potential use for the treatment of pruritus that cannot be treated with histamine receptor blockers alone. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. PreSMA stimulation changes task-free functional connectivity in the fronto-basal-ganglia that correlates with response inhibition efficiency.

    PubMed

    Xu, Benjamin; Sandrini, Marco; Wang, Wen-Tung; Smith, Jason F; Sarlls, Joelle E; Awosika, Oluwole; Butman, John A; Horwitz, Barry; Cohen, Leonardo G

    2016-09-01

    Previous work using transcranial magnetic stimulation (TMS) demonstrated that the right presupplementary motor area (preSMA), a node in the fronto-basal-ganglia network, is critical for response inhibition. However, TMS influences interconnected regions, raising the possibility of a link between the preSMA activity and the functional connectivity within the network. To understand this relationship, we applied single-pulse TMS to the right preSMA during functional magnetic resonance imaging when the subjects were at rest to examine changes in neural activity and functional connectivity within the network in relation to the efficiency of response inhibition evaluated with a stop-signal task. The results showed that preSMA-TMS increased activation in the right inferior-frontal cortex (rIFC) and basal ganglia and modulated their task-free functional connectivity. Both the TMS-induced changes in the basal-ganglia activation and the functional connectivity between rIFC and left striatum, and of the overall network correlated with the efficiency of response inhibition and with the white-matter microstructure along the preSMA-rIFC pathway. These results suggest that the task-free functional and structural connectivity between the rIFCop and basal ganglia are critical to the efficiency of response inhibition. Hum Brain Mapp 37:3236-3249, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Inhibiting effects of Streptococcus salivarius on competence-stimulating peptide-dependent biofilm formation by Streptococcus mutans.

    PubMed

    Tamura, S; Yonezawa, H; Motegi, M; Nakao, R; Yoneda, S; Watanabe, H; Yamazaki, T; Senpuku, H

    2009-04-01

    The effects of Streptococcus salivarius on the competence-stimulating peptide (CSP)-dependent biofilm formation by Streptococcus mutans were investigated. Biofilms were grown on 96-well microtiter plates coated with salivary components in tryptic soy broth without dextrose supplemented with 0.25% sucrose. Biofilm formations were stained using safranin and quantification of stained biofilms was performed by measuring absorbance at 492 nm. S. mutans formed substantial biofilms, whereas biofilms of S. salivarius were formed poorly in the medium conditions used. Furthermore, in combination cultures, S. salivarius strongly inhibited biofilm formation when cultured with S. mutans. This inhibition occurred in the early phase of biofilm formation and was dependent on inactivation of the CSP of S. mutans, which is associated with competence, biofilm formation, and antimicrobial activity of the bacterium, and is induced by expression of the comC gene. Comparisons between the S. mutans clinical strains FSC-3 and FSC-3DeltaglrA in separate dual-species cultures with S. salivarius indicated that the presence of the bacitracin transport ATP-binding protein gene glrA caused susceptibility to inhibition of S. mutans biofilm formation by S. salivarius, and was also associated with the regulation of CSP production by com gene-dependent quorum sensing systems. It is considered that regulation of CSP by glrA in S. mutans and CSP inactivation by S. salivarius are important functions for cell-to-cell communication between biofilm bacteria and oral streptococci such as S. salivarius. Our results provide useful information for understanding the ecosystem of oral streptococcal biofilms, as well as the competition between and coexistence of multiple species in the oral cavity.

  14. Plasticity of cortical inhibition in dystonia is impaired after motor learning and paired-associative stimulation.

    PubMed

    Meunier, Sabine; Russmann, Heike; Shamim, Ejaz; Lamy, Jean-Charles; Hallett, Mark

    2012-03-01

    Artificial induction of plasticity by paired associative stimulation (PAS) in healthy volunteers (HV) demonstrates Hebbian-like plasticity in selected inhibitory networks as well as excitatory networks. In a group of 17 patients with focal hand dystonia and a group of 19 HV, we evaluated how PAS and the learning of a simple motor task influence the circuits supporting long-interval intracortical inhibition (LICI, reflecting activity of GABA(B) interneurons) and long-latency afferent inhibition (LAI, reflecting activity of somatosensory inputs to the motor cortex). In HV, PAS and motor learning induced long-term potentiation (LTP)-like plasticity of excitatory networks and a lasting decrease of LAI and LICI in the motor representation of the targeted or trained muscle. The better the motor performance, the larger was the decrease of LAI. Although motor performance in the patient group was similar to that of the control group, LAI did not decrease during the motor learning as it did in the control group. In contrast, LICI was normally modulated. In patients the results after PAS did not match those obtained after motor learning: LAI was paradoxically increased and LICI did not exhibit any change. In the normal situation, decreased excitability in inhibitory circuits after induction of LTP-like plasticity may help to shape the cortical maps according to the new sensorimotor task. In patients, the abnormal or absent modulation of afferent and intracortical long-interval inhibition might indicate maladaptive plasticity that possibly contributes to the difficulty that they have to learn a new sensorimotor task. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  15. Abdominal Subcutaneous Mass After Laser-Assisted Lipolysis and Immediate Multiple Treatments with a Dual-Wavelength Laser, Vacuum and Massage Device.

    PubMed

    Gentileschi, Stefano; Servillo, Maria; D'Ettorre, Marco; Salgarello, Marzia

    2016-04-01

    Body contouring by means of minimally invasive procedures is a growing trend. Current approaches to body contouring often involve a combination of surgical techniques (eg, laser-assisted liposuction) and a series of noninvasive device-based treatments aimed at accelerating recovery and improving aesthetic outcomes. In this case study, we describe a 38-year-old woman who presented with an abdominal-wall mass that resembled a tumor when assessed with magnetic resonance imaging. Twenty-six months before presenting to our office, the patient had undergone laser lipolysis and a series of treatments with a device that delivered dual-wavelength laser energy and vacuum-assisted massage. To address the patient's concerns, we removed the mass and performed abdominal dermolipectomy. No postoperative complications occurred, and the patient was highly satisfied with the aesthetic outcome. The results of histologic studies indicated that the mass was pseudocystic and fluid-filled, surrounded by a fibrous capsule, and characterized as a foreign-body granuloma. Further analysis is warranted regarding the safety of laser lipolysis without aspiration combined with a device delivering dual-wavelength laser energy and vacuum-assisted massage. 5 Risk. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  16. MEAT SCIENCE AND MUSCLE BIOLOGY SYMPOSIUM--mechanism of growth hormone stimulation of skeletal muscle growth in cattle.

    PubMed

    Jiang, H; Ge, X

    2014-01-01

    Growth hormone, also called somatotropin (ST), is a polypeptide hormone produced by the anterior pituitary. The major functions of GH include stimulating bone and skeletal muscle growth, lipolysis, milk production, and expression of the IGF-I gene in the liver. Based on these functions, recombinant bovine ST (bST) and recombinant porcine ST (pST) have been used to improve milk production in dairy cows and lean tissue growth in pigs, respectively. However, despite these applications, the mechanisms of action of GH are not fully understood. Indeed, there has been a lot of controversy over the role of liver-derived circulating IGF-I and locally produced IGF-I in mediating the growth-stimulatory effect of GH during the last 15 yr. It is in this context that we have conducted studies to further understand how GH stimulates skeletal muscle growth in cattle. Our results do not support a role of skeletal muscle-derived IGF-I in GH-stimulated skeletal muscle growth in cattle. Our results indicate that GH stimulates skeletal muscle growth in cattle, in part, by stimulating protein synthesis in muscle through a GH receptor-mediated, IGF-I-independent mechanism. In this review, besides discussing these results, we also argue that liver-derived circulating IGF-I should be still considered as the major mechanism that mediates the growth-stimulatory effect of GH on skeletal muscle in cattle and other domestic animals.

  17. Inhibition of hepatic lipogenesis by 2-tetradecylglycidic acid.

    PubMed

    McCune, S A; Nomura, T; Harris, R A

    1979-10-01

    2-Tetradecylglycidic acid (TDGA), a hypoglycemic agent, has been found to be a very effective inhibitor of de novo fatty acid synthesis by isolated hepatocytes. A comparison was made between the effectiveness of TDGA and 5-(tetradecyloxy)-2-furoic acid (TOFA), a hypolipidemic agent, on the metabolic processes of isolated hepatocytes. These compounds are structurally related and both inhibit fatty acid synthesis; however, they have opposite effects from each other on the oxidation and esterification of fatty acids. TDGA inhibits whereas TOFA stimulates fatty acid oxidation. TDGA stimulates whereas TOFA inhibits fatty acid esterification.

  18. Cardiotonic agent milrinone stimulates resorption in rodent bone organ culture.

    PubMed Central

    Krieger, N S; Stappenbeck, T S; Stern, P H

    1987-01-01

    The cardiotonic agent amrinone inhibits bone resorption in vitro. Milrinone, an amrinone analog, is a more potent cardiotonic agent with lower toxicity. In contrast to amrinone, milrinone stimulated resorption in cultures of neonatal mouse calvaria and fetal rat limb bones. Threshold doses were 0.1 microM in calvaria and 0.1 mM in limb bones; maximal stimulation occurred in calvaria at 0.1 mM. Maximal responses to milrinone and parathyroid hormone were comparable. Milrinone concentrations below 0.1 mM did not affect calvarial cyclic AMP. 0.5 microM indomethacin inhibited milrinone effects in calvaria but usually not in limb bones. 3 nM calcitonin inhibited milrinone-stimulated resorption and there was no escape from this inhibition. Structural homology between milrinone and thyroxine has been reported. We find similarities between milrinone and thyroxine actions on bone, because prostaglandin production was crucial for the effects of both agents in calvaria but not in limb bones, and neither agent exhibited escape from calcitonin inhibition. PMID:3027124

  19. Butylated Hydroxyanisole Stimulates Heme Oxygenase-1 Gene Expression and Inhibits Neointima Formation in Rat Arteries

    PubMed Central

    Liu, Xiao-ming; Azam, Mohammed A.; Peyton, Kelly J.; Ensenat, Diana; Keswani, Amit N.; Wang, Hong; Durante, William

    2007-01-01

    Objective Butylated hydroxyanisole (BHA) is a synthetic phenolic compound that is a potent inducer of phase II genes. Since heme oxygenase-1 (HO-1) is a vasoprotective protein that is upregulated by phase II inducers, the present study examined the effects of BHA on HO-1 gene expression and vascular smooth muscle cell proliferation. Methods The regulation of HO-1 gene expression and vascular cell growth by BHA was studied in cultured rat aortic smooth muscle cells and in balloon injured rat carotid arteries. Results Treatment of cultured smooth muscle cells with BHA stimulated the expression of HO-1 protein, mRNA and promoter activity in a time- and concentration-dependent manner. BHA-mediated HO-1 expression was dependent on the activation of NF-E2-related factor-2 by p38 mitogen-activated protein kinase. BHA also inhibited cell cycle progression and DNA synthesis in a HO-1-dependent manner. In addition, the local perivascular delivery of BHA immediately after arterial injury of rat carotid arteries induced HO-1 protein expression and markedly attenuated neointima formation. Conclusions These studies demonstrate that BHA stimulates HO-1 gene expression in vascular smooth muscle cells, and that the induction of HO-1 contributes to the antiproliferative actions of this phenolic antioxidant. BHA represents a potentially novel therapeutic agent in treating or preventing vasculoproliferative disease. PMID:17320844

  20. Ginkgolide B Reduces LOX-1 Expression by Inhibiting Akt Phosphorylation and Increasing Sirt1 Expression in Oxidized LDL-Stimulated Human Umbilical Vein Endothelial Cells

    PubMed Central

    Chen, Beidong; Li, Xingguang; Qi, Ruomei

    2013-01-01

    Oxidized low-density lipoprotein (ox-LDL) is an important risk factor in the development of atherosclerosis. LOX-1, a lectin-like receptor for ox-LDL, is present primarily on endothelial cells and upregulated by ox-LDL, tumor necrosis factor a, shear stress, and cytokines in atherosclerosis. Recent studies demonstrated that ginkgolide B, a platelet-activating factor receptor antagonist, has antiinflammatory and antioxidant effects on endothelial and nerve cells. The present study investigated the effects of ginkgolide B on LOX-1 expression and the possible mechanism of action. Our results showed that ginkgolide B inhibited LOX-1 and intercellular cell adhesion molecule-1 (ICAM-1) expression in ox-LDL-stimulated endothelial cells through a mechanism associated with the attenuation of Akt activation. Similar data were obtained by silencing Akt and LY294002. We also evaluated Sirt1 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression. These molecules play a protective role in endothelial cell injury. The results showed that ginkgolide B increased Sirt1 expression in ox-LDL-treated cells. The inhibitory effects of ginkgolide B on LOX-1 and ICAM-1 expression were reduced in Sirt1 siRNA-transfected cells. Nrf2 expression was increased in ox-LDL-treated cells, and ginkgolide B downregulated Nrf2 expression. These results suggest that ginkgolide B reduces Nrf2 expression by inhibiting LOX-1 expression, consequently reducing oxidative stress injury in ox-LDL-stimulated cells. Altogether, these results indicate that the protective effect of ginkgolide B on endothelial cells may be attributable to a decrease in LOX-1 expression and an increase in Sirt1 expression in ox-LDL-stimulated endothelial cells, the mechanism of which is linked to the inhibition of Akt activation. Ginkgolide B may be a multiple-target drug that exerts protective effects in ox-LDL-treated human umbilical vein endothelial cells. PMID:24069345

  1. Neuropeptide-stimulated cell migration in prostate cancer cells is mediated by RhoA kinase signaling and inhibited by neutral endopeptidase.

    PubMed

    Zheng, R; Iwase, A; Shen, R; Goodman, O B; Sugimoto, N; Takuwa, Y; Lerner, D J; Nanus, D M

    2006-09-28

    The neuropeptides bombesin and endothelin-1 stimulate prostate cancer (PC) cell migration and invasion (J Clin Invest, 2000; 106: 1399-1407). The intracellular signaling pathways that direct this cell movement are not well delineated. The monomeric GTPase RhoA is required for migration in several cell types including neutrophils, monocytes and fibroblasts. We demonstrate that bombesin-stimulated PC cell migration occurs via the heterotrimeric G-protein-coupled receptors (G-protein) G alpha 13 subunit leading to activation of RhoA, and Rho-associated coiled-coil forming protein kinase (ROCK). Using siRNA to suppress expression of the three known G-protein alpha-subunit-associated RhoA guanine nucleotide exchange factors (GEFs), we also show that two of these RhoA GEFs, PDZ-RhoGEF and leukemia-associated RhoGEF (LARG), link bombesin receptors to RhoA in a non-redundant manner in PC cells. We next show that focal adhesion kinase, which activates PDZ-RhoGEF and LARG, is required for bombesin-stimulated RhoA activation. Neutral endopeptidase (NEP) is expressed on normal prostate epithelium whereas loss of NEP expression contributes to PC progression. We also demonstrate that NEP inhibits neuropeptide activation of RhoA. Together, these results establish a contiguous signaling pathway from the bombesin receptor to ROCK in PC cells, and they implicate NEP as a major regulator of neuropeptide-stimulated RhoA in these cells. This work also identifies members of this signaling pathway as potential targets for rational pharmacologic manipulation of neuropeptide-stimulated migration of PC cells.

  2. Oligosynaptic inhibition of group Ia afferents from brachioradialis to triceps brachii motor neurons in humans.

    PubMed

    Sato, Toshiaki; Nito, Mitsuhiro; Suzuki, Katsuhiko; Fujii, Hiromi; Hashizume, Wataru; Miyasaka, Takuji; Shindo, Masaomi; Naito, Akira

    2018-01-01

    This study examines effects of low-threshold afferents from the brachioradialis (BR) on excitability of triceps brachii (TB) motor neurons in humans. We evaluated the effects using a post stimulus time histogram (PSTH) and electromyogram averaging (EMG-A) methods in 13 healthy human participants. Electrical conditioning stimulation to the radial nerve branch innervating BR with the intensity below the motor threshold was delivered. In the PSTH study, the stimulation produced a trough (inhibition) in 36/69 TB motor units for all the participants. A cutaneous stimulation never provoked such inhibition. The central latency of the inhibition was 1.5 ± 0.5 ms longer than that of the homonymous facilitation. In the EMG-A study, the stimulation produced inhibition in EMG-A of TB in all participants. The inhibition diminished with a tonic vibration stimulation to BR. These findings suggest that oligosynaptic inhibition mediated by group Ia afferents from BR to TB exists in humans. Muscle Nerve 57: 122-128, 2018. © 2017 Wiley Periodicals, Inc.

  3. Lactoferrin release and interleukin-1, interleukin-6, and tumor necrosis factor production by human polymorphonuclear cells stimulated by various lipopolysaccharides: relationship to growth inhibition of Candida albicans.

    PubMed

    Palma, C; Cassone, A; Serbousek, D; Pearson, C A; Djeu, J Y

    1992-11-01

    Lipopolysaccharides (LPSs) from Escherichia coli, Serratia marcescens, and Salmonella typhimurium, at doses from 1 to 100 ng/ml, strongly enhanced growth inhibition of Candida albicans by human polymorphonuclear leukocytes (PMN) in vitro. Flow cytometry analysis demonstrated that LPS markedly augmented phagocytosis of Candida cells by increasing the number of yeasts ingested per neutrophil as well as the number of neutrophils capable of ingesting fungal cells. LPS activation caused augmented release of lactoferrin, an iron-binding protein which itself could inhibit the growth of C. albicans in vitro. Antibodies against lactoferrin effectively and specifically reduced the anti-C. albicans activity of both LPS-stimulated and unstimulated PMN. Northern (RNA blot) analysis showed enhanced production of mRNAs for interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 and in neutrophils within 1 h of stimulation with LPS. The cytokines were also detected in the supernatant of the activated PMN, and their synthesis was prevented by pretreatment of LPS-stimulated PMN with protein synthesis inhibitors, such as emetine and cycloheximide. These inhibitors, however, did not block either lactoferrin release or the anti-Candida activity of LPS-stimulated PMN. These results demonstrate the ability of various bacterial LPSs to augment neutrophil function against C. albicans and suggest that the release of a candidastatic, iron-binding protein, lactoferrin, may contribute to the antifungal effect of PMN. Moreover, the ability to produce cytokines upon stimulation by ubiquitous microbial products such as the endotoxins points to an extraphagocytic, immunomodulatory role of PMN during infection.

  4. Gamma-tocotrienol inhibits lipopolysaccharide-induced interlukin-6 and granulocyte-colony stimulating factor by suppressing C/EBP-β and NF-κB in macrophages

    PubMed Central

    Wang, Yun; Jiang, Qing

    2012-01-01

    Cytokines generated from macrophages contributes to pathogenesis of inflammation-associated diseases. Here we show that gamma-tocotrienol (γ-TE), a natural vitamin E form, inhibits lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) production without affecting TNFα, IL-10 or cyclooxygenase-2 (COX-2) up-regulation in murine RAW267.4 macrophages. Mechanistic studies indicate that nuclear factor (NF)-κB, but not JNK, p38 or ERK MAP kinases, is important to IL-6 production and γ-TE treatment blocks NF-κB activation. In contrast, COX-2 appears to be regulated by p38 MAPK in RAW cells, but γ-TE has no effect on LPS-stimulated p38 phosphorylation. Despite necessary for IL-6, NF-κB activation by TNFα or other cytokines is not sufficient for IL-6 induction with exception of LPS. CCAAT-enhancer binding protein β (C/EBPβ) appears to be involved in IL-6 formation, because LPS induces C/EBPβ up-regulation, which parallels IL-6 production, and knockdown of C/EBPβ with siRNA results in diminished IL-6. LPS but not individual cytokines is capable of stimulating C/EBPβ and IL-6 in macrophages. Consistent with its dampening effect on IL-6, γ-TE blunts LPS-induced up-regulation of C/EBPβ without affecting C/EBPδ. γ-TE also decreases LPS-stimulated granulocyte-colony stimulating factor (G-CSF), a C/EBPβ target gene. Compared with RAW267.4 cells, γ-TE shows similar or stronger inhibitory effects on LPS-triggered activation of NF-κB, C/EPBβ and C/EBPδ, and more potently suppresses IL-6 and G-CSF in bone marrow-derived macrophages. Our study demonstrates that γ-TE has anti-inflammatory activities by inhibition of NF-κB and C/EBPs activation in macrophages. PMID:23246159

  5. Watching intracellular lipolysis in mycobacteria using time lapse fluorescence microscopy.

    PubMed

    Dhouib, Rabeb; Ducret, Adrien; Hubert, Pierre; Carrière, Frédéric; Dukan, Sam; Canaan, Stéphane

    2011-04-01

    The fact that Mycobacterium tuberculosis mobilizes lipid bodies (LB) located in the cytosol during infection process has been proposed for decades. However, the mechanisms and dynamics of mobilization of these lipid droplets within mycobacteria are still not completely characterized. Evidence in favour of this characterization was obtained here using a combined fluorescent microscopy and computational image processing approach. The decrease in lipid storage levels observed under nutrient depletion conditions was correlated with a significant increase in the size of the bacteria. LB fragmentation/condensation cycles were monitored in real time. The exact contribution of lipases in this process was confirmed using the lipase inhibitor tetrahydrolipstatin, which was found to prevent LB degradation and to limit the bacterial cell growth. The method presented here provides a powerful tool for monitoring in vivo lipolysis in mycobacteria and for obtaining new insights on the growth of cells and their entry into the dormant or reactivation phase. It should be particularly useful for studying the effects of chemical inhibitors and activators on cells as well as investigating other metabolic pathways. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Increased lipolysis, diminished adipose tissue insulin sensitivity and impaired B-cell function relative to adipose tissue insulin sensitivity in obese youth with impaired glucose tolerance (IGT)

    USDA-ARS?s Scientific Manuscript database

    Despite evidence of insulin resistance and B-cell dysfunction in glucose metabolism in youth with prediabetes, the relationship between adipose tissue insulin sensitivity (ATIS) and B-cell function remains unknown. We investigated whole-body lipolysis, ATIS and B-cell function relative to ATIS [adip...

  7. Neomycin inhibits PDGF-induced IP3 formation and DNA synthesis but not PDGF-stimulated uptake of inorganic phosphate in C3H/10T1/2 fibroblasts.

    PubMed

    Vassbotn, F S; Langeland, N; Holmsen, H

    1990-09-01

    Porcine PDGF was found to increase [3H]inositol trisphosphate, [3H]thymidine incorporation and 32P-labelling of polyphosphoinositides in C3H/10T1/2 Cl 8 fibroblasts. These responses to PDGF stimulation were all inhibited by 5 mM neomycin, a polycationic aminoglycoside formerly known to inhibit polyphosphoinositide turnover. PDGF also markedly increased the cellular uptake of inorganic [32P]Pi. This response of PDGF was not inhibited by neomycin (5 mM). Thus, neomycin inhibited PDGF-induced IP3 formation, 32P-labelling of polyphosphoinositides and DNA synthesis, but not cellular uptake of inorganic phosphate. These effects of neomycin suggest a bifurcation of the initial part of the PDGF-induced signal transduction, separating at the receptor level or before phospholipase C activation.

  8. Inhibition of Pre-Supplementary Motor Area by Continuous Theta Burst Stimulation Leads to More Cautious Decision-making and More Efficient Sensory Evidence Integration.

    PubMed

    Tosun, Tuğçe; Berkay, Dilara; Sack, Alexander T; Çakmak, Yusuf Ö; Balcı, Fuat

    2017-08-01

    Decisions are made based on the integration of available evidence. The noise in evidence accumulation leads to a particular speed-accuracy tradeoff in decision-making, which can be modulated and optimized by adaptive decision threshold setting. Given the effect of pre-SMA activity on striatal excitability, we hypothesized that the inhibition of pre-SMA would lead to higher decision thresholds and an increased accuracy bias. We used offline continuous theta burst stimulation to assess the effect of transient inhibition of the right pre-SMA on the decision processes in a free-response two-alternative forced-choice task within the drift diffusion model framework. Participants became more cautious and set higher decision thresholds following right pre-SMA inhibition compared with inhibition of the control site (vertex). Increased decision thresholds were accompanied by an accuracy bias with no effects on post-error choice behavior. Participants also exhibited higher drift rates as a result of pre-SMA inhibition compared with the vertex inhibition. These results, in line with the striatal theory of speed-accuracy tradeoff, provide evidence for the functional role of pre-SMA activity in decision threshold modulation. Our results also suggest that pre-SMA might be a part of the brain network associated with the sensory evidence integration.

  9. Sulforaphane induced adipolysis via hormone sensitive lipase activation, regulated by AMPK signaling pathway.

    PubMed

    Lee, Ju-Hee; Moon, Myung-Hee; Jeong, Jae-Kyo; Park, Yang-Gyu; Lee, You-Jin; Seol, Jae-Won; Park, Sang-Youel

    2012-10-05

    Sulforaphane, an aliphatic isothiocyanate derived from cruciferous vegetables, is known for its antidiabetic properties. The effects of sulforaphane on lipid metabolism in adipocytes are not clearly understood. Here, we investigated whether sulforaphane stimulates lipolysis. Mature adipocytes were incubated with sulforaphane for 24h and analyzed using a lipolysis assay which quantified glycerol released into the medium. We investigated gene expression of hormone-sensitive lipase (HSL), and levels of HSL phosphorylation and AMP-activated protein kinase on sulforaphane-mediated lipolysis in adipocytes. Sulforaphane promoted lipolysis and increased both HSL gene expression and HSL activation. Sulforaphane suppressed AMPK phosphorylation at Thr-172 in a dose-dependent manner, which was associated with a decrease in HSL phosphorylation at Ser-565, enhancing the phosphorylation of HSL Ser-563. Taken together, these results suggest that sulforaphane promotes lipolysis via hormone sensitive lipase activation mediated by decreasing AMPK signal activation in adipocytes. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Cognitive stimulation in healthy older adults: a cognitive stimulation program using leisure activities compared to a conventional cognitive stimulation program.

    PubMed

    Grimaud, Élisabeth; Taconnat, Laurence; Clarys, David

    2017-06-01

    The aim of this study was to compare two methods of cognitive stimulation for the cognitive functions. The first method used an usual approach, the second used leisure activities in order to assess their benefits on cognitive functions (speed of processing; working memory capacity and executive functions) and psychoaffective measures (memory span and self esteem). 67 participants over 60 years old took part in the experiment. They were divided into three groups: 1 group followed a program of conventional cognitive stimulation, 1 group a program of cognitive stimulation using leisure activities and 1 control group. The different measures have been evaluated before and after the training program. Results show that the cognitive stimulation program using leisure activities is as effective on memory span, updating and memory self-perception as the program using conventional cognitive stimulation, and more effective on self-esteem than the conventional program. There is no difference between the two stimulated groups and the control group on speed of processing. Neither of the two cognitive stimulation programs provides a benefit over shifting and inhibition. These results indicate that it seems to be possible to enhance working memory and to observe far transfer benefits over self-perception (self-esteem and memory self-perception) when using leisure activities as a tool for cognitive stimulation.

  11. Anti-obesity effect of extract from fermented Curcuma longa L. through regulation of adipogenesis and lipolysis pathway in high-fat diet-induced obese rats

    PubMed Central

    Kim, Ji Hye; Kim, Ok-Kyung; Yoon, Ho-Geun; Park, Jeongjin; You, Yanghee; Kim, Kyungmi; Lee, Yoo-Hyun; Choi, Kyung-Chul; Lee, Jeongmin; Jun, Woojin

    2016-01-01

    Background Even though Curcuma longa L. possesses various biological activities, it has strong flavor and taste, which decrease consumer palatability and limit industrial applications in food. Objective The present study investigates the effects of C. longa L. fermented with Aspergillus oryzae supplementation in 60% high-fat diet-induced obese rats measured by the activation of adipogenesis and lipolysis. Design Rats were divided into four groups (n=6 per group) after 1 week of acclimatization: a normal diet group comprised rats fed the AIN76A rodent diet; a high-fat diet-induced obese group with rats fed a 60% high-fat diet; a Garcinia cambogia treated group (positive control) with rats fed a 60% high-fat diet with G. cambogia 500 g/kg body weight (b.w.)/day; and an fermented C. longa L. 50% ethanolic extract treated group (FCE50) with rats fed a 60% high-fat diet with FCE50 500 g/kg b.w./day. Each group received the appropriate vehicle or sample daily by gastric intubation for 12 weeks. Results We found that FCE50 administration suppressed b.w. gain and reduced white adipose tissue weight, serum triglyceride (TG), and cholesterol in high-fat diet-induced obese rats. These results can be associated with the suppression of adipocyte differentiation and lipogenesis with a decrease in the mRNA expressions of fatty acid synthase, acetyl-CoA carboxylase, adipocyte protein 2, and lipoprotein lipase induced by FCE50 administration. In addition, FCE50 increased lipolysis and β-oxidation by up-regulating the expression of lipases such as adipose triglyceride lipase, hormone-sensitive lipase, adiponectin, and AMP-activated protein kinase. Conclusions These results suggest that FCE50 can be a candidate for the prevention of obesity via suppressing adipogenesis and promoting lipolysis. PMID:26822962

  12. Schizandrin inhibits fibrosis and epithelial-mesenchymal transition in transforming growth factor-β1-stimulated AML12 cells.

    PubMed

    Park, Ji-hyun; Yoon, Jaewoo

    2015-04-01

    The transforming growth factor (TGF)-β1 plays a crucial role in the induction of the epithelial-to-mesenchymal transition (EMT) in hepatocytes, which contributes to the pathogenesis of liver fibrosis. The inhibition of the TGF-β1 cascade suppresses EMT and the resultant fibrosis. Schizandrin (Sch) has various therapeutic effects on a range of medical conditions such as anti-asthmatic, anti-cancer, and anti-inflammatory effects. However, the effect of Sch on TGF-β1-stimulated hepatic fibrosis and EMT is still unknown. In the present investigation, we evaluated the anti-fibrotic and anti-EMT properties of Sch and its underlying mechanisms in murine hepatocyte AML12 cells. Overall, we found that Sch inhibited the pro-fibrotic activity of TGF-β1 in AML12 cells; thus, it suppressed the accumulation of ECM proteins. Also, Sch inhibited the EMT as assessed by reduced expression of vimentin and fibronectin, and increased E-cadherin and ZO-1 in TGF-β1 induced AML12 cells. Sch reduced TGF-β1-mediated phosphorylation of Smad2/3 and Smad3/4 DNA binding activity. On the other hand, Sch reduced TGF-β1-induced ERK1/2 and PI3K/Akt phosphorylation in the non-Smad pathway. In conclusion, Sch can antagonize TGF-β1-mediated fibrosis and EMT in AML12 cells. Sch may possess potential as an anti-fibrotic molecule in the treatment of liver fibrosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Effects of locus coeruleus stimulation on the responses of SI neurons of the rat to controlled natural and electrical stimulation of the skin.

    PubMed

    Snow, P J; Andre, P; Pompeiano, O

    1999-02-01

    1. The effects of microstimulation of the locus coeruleus (LC) region on the spontaneous discharge and the response of SI neurons to natural and electrical stimulation of the skin have been investigated in 26 urethane anesthetized Sprague-Dawley rats. In particular, one or two air puffs, 5-10 msec in duration, 1-2 psi, usually separated by an interval of 40 msec, were applied on the hairy skin of the wrist or the forepaw at the presentation rate of 1/sec. For units unresponsive to air puffs, similar presentation of low intensity electrical stimuli (0.2-5.0 V, 0.2-0.4 msec pulses) were applied through two needles inserted on the most effective area of the skin. Both natural and electrical stimulations of the skin were applied under control conditions, as well as 50 msec after a 250 msec train of 0.3 msec pulses at 40 Hz. 20-30 microA applied stereotaxically to the LC complex through a tungsten microelectrode. 2. Not all cortical units exhibited spontaneous discharge. Most of the units, however, which were spontaneously active, were inhibited by electrical stimulation of the LC complex, while the remaining ones were excited. The sites of stimulation, which included either the LC proper or the locus subcoeruleus, were identified following both anatomical and physiological criteria. 3. SI neurons recorded at sites between 400 and 950 microns below the surface of the cortex, thus being most likely granule cells of layers III and IV, responded to cutaneous stimuli with spikes which occurred with a latency of 20-30 msec in response to single air puffs and a latency of 15-20 msec in response to single electrical pulses to the skin. In both instances the response to the second stimulus applied at the interstimulus interval of 40 msec was markedly reduced or abolished due to postexcitatory inhibition following the response to the first stimulus (in-field inhibition). In contrast, units particularly located at or below 1000 microns from the cortical surface, which were of

  14. CO from enhanced HO activity or from CORM-2 inhibits both O2- and NO production and downregulates HO-1 expression in LPS-stimulated macrophages.

    PubMed

    Srisook, Klaokwan; Han, Shan-Shu; Choi, Hyung-Sim; Li, Mei-Hua; Ueda, Hideo; Kim, Chaekyun; Cha, Young-Nam

    2006-01-12

    Carbon monoxide (CO) arising from heme degradation, catalyzed particularly by the stress-inducible heme oxygenase-1 (HO-1), has recently been demonstrated to provide cytoprotection against cell death in macrophages stimulated with bacterial lipopolysaccharide (LPS). In the present study, we determined the effects of CO on the production of reactive oxygen species (ROS) and nitric oxide (NO) by the LPS-stimulated RAW 264.7 macrophages. In addition, effect of CO-exposure on the production of superoxide (O(2)(-)) in the phorbol myristate acetate (PMA)-stimulated PLB-985 neutrophils was determined. Production of ROS by the LPS-stimulated macrophages pretreated with 50microM [Ru(CO)(3)Cl(2)](2), a CO-releasing molecule (CORM-2), was abolished and the production of O(2)(-) by the PMA-stimulated neutrophils pretreated with the CORM-2 was decreased markedly. The CORM-2 (50microM) was not cytotoxic to both the unstimulated and LPS-stimulated macrophages when determined by employing mitochondrial reductase function test (MTT assay). In macrophages pretreated with increasing doses of CORM-2, both the LPS-derived upregulations of iNOS (NO production) and HO-1 expression (CO production) were suppressed in a dose-dependent manner. Alternatively, when the macrophages were treated with LPS and CO-donor together, the LPS-derived increase in NO production was decreased. Conversely, when the control and LPS-stimulated macrophages were treated with zinc protoporphyrin IX (ZnPP) to inhibit the HO activity blocking endogenous production of CO (basal and enhanced), macrophages died extensively. Interestingly, production of NO in the LPS-stimulated macrophages increased significantly following the ZnPP treatment. Addition of CORM-2 to the LPS-treated cells that were being treated additionally with ZnPP did not prevent the cell death. However, endogenous overproduction of CO by super-induction of HO-1 (obtained by pretreatment of macrophages with either buthionine sulfoximine or hemin

  15. IGFBP-3, hypoxia and TNF-{alpha} inhibit adiponectin transcription

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zappala, Giovanna, E-mail: zappalag@mail.nih.gov; Rechler, Matthew M.; Clinical Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD

    2009-05-15

    The thiazolidinedione rosiglitazone, an agonist ligand for the nuclear receptor PPAR-{gamma}, improves insulin sensitivity in part by stimulating transcription of the insulin-sensitizing adipokine adiponectin. It activates PPAR-{gamma}-RXR-{alpha} heterodimers bound to PPAR-{gamma} response elements in the adiponectin promoter. Rosiglitazone-stimulated adiponectin protein synthesis in 3T3-L1 mouse adipocytes has been shown to be inhibited by IGFBP-3, which can be induced by hypoxia and the proinflammatory cytokine, TNF-{alpha}, two inhibitors of adiponectin transcription. The present study demonstrates that IGFBP-3, the hypoxia-mimetic agent cobalt chloride, and TNF-{alpha} inhibit rosiglitazone-induced adiponectin transcription in mouse embryo fibroblasts that stably express PPAR-{gamma}2. Native IGFBP-3 can bind RXR-{alpha} andmore » inhibited rosiglitazone stimulated promoter activity, whereas an IGFBP-3 mutant that does not bind RXR-{alpha} did not. These results suggest that IGFBP-3 may mediate the inhibition of adiponectin transcription by hypoxia and TNF-{alpha}, and that IGFBP-3 binding to RXR-{alpha} may be required for the observed inhibition.« less

  16. A biokinetic model to describe consequences of inhibition/stimulation in DNA-proofreading and repair-1. Development of the model.

    PubMed

    Haschke, H

    2001-10-21

    A biokinetic model is described which deals with the mathematical consequences of the inhibition or stimulation of DNA proofreading. It demonstrates the development of the number of DNA mismatch-dependent cells (e.g. cells with a malignant phenotype), where such mismatches arise by the in situ interaction of various substances with nucleotides of the DNA. The model can test for consequences by a logic gating on an "if-then" type of analysis in relation to the separate and consecutive processes of proofreading and repair. In particular, the consequences are considered in cases where either (i) the efficacy of proofreading and repair are reduced/prevented (inhibited) or (ii) are increased by some form of stimulation. On the chosen kinetic parameters, the model is accessible to manipulation as new data arising from further investigations become available and are introduced. The model is based on recently published data which show that an increased "mutant fraction" (see note on terms) arises in DNA replication when intracellular nucleotide pools show "asymmetries" (see note on terms). Extraordinarily high mutant fractions can be predicted/have been recorded in the presence of proofreading inhibitors. The model expresses data in mathematical terms of the competition between the development of mismatch-dependent cells and those with authentic genetic information. (Feedback and metastasis-effects and those of wild-type replicates are included.) A computerized (numerical) integration of the corresponding set of differential equations is offered. (A diskette with the program CANCER.xls is available upon request.) Copyright 2001 Academic Press

  17. Effects of Biotin Supplementation in the Diet on Adipose Tissue cGMP Concentrations, AMPK Activation, Lipolysis, and Serum-Free Fatty Acid Levels.

    PubMed

    Boone-Villa, Daniel; Aguilera-Méndez, Asdrubal; Miranda-Cervantes, Adriana; Fernandez-Mejia, Cristina

    2015-10-01

    Several studies have shown that pharmacological concentrations of biotin decrease hyperlipidemia. The molecular mechanisms by which pharmacological concentrations of biotin modify lipid metabolism are largely unknown. Adipose tissue plays a central role in lipid homeostasis. In the present study, we analyzed the effects of biotin supplementation in adipose tissue on signaling pathways and critical proteins that regulate lipid metabolism, as well as on lipolysis. In addition, we assessed serum fatty acid concentrations. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet (control: 1.76 mg biotin/kg; supplemented: 97.7 mg biotin/kg diet) over 8 weeks postweaning. Compared with the control group, biotin-supplemented mice showed an increase in the levels of adipose guanosine 3',5'-cyclic monophosphate (cGMP) (control: 30.3±3.27 pmol/g wet tissue; supplemented: 49.5±3.44 pmol/g wet tissue) and of phosphorylated forms of adenosine 5'-monophosphate-activated protein kinase (AMPK; 65.2%±1.06%), acetyl-coenzyme A (CoA), carboxylase-1 (196%±68%), and acetyl-CoA carboxylase-2 (78.1%±18%). Serum fatty acid concentrations were decreased (control: 1.12±0.04 mM; supplemented: 0.91±0.03 mM), and no change in lipolysis was found (control: 0.29±0.05 μmol/mL; supplemented: 0.33±0.08 μmol/mL). In conclusion, 8 weeks of dietary biotin supplementation increased adipose tissue cGMP content and protein expression of the active form of AMPK and of the inactive forms of acetyl-CoA carboxylase-1 and acetyl-CoA carboxylase-2. Serum fatty acid levels fell, and no change in lipolysis was observed. These findings provide insight into the effects of biotin supplementation on adipose tissue and support its use in the treatment of dyslipidemia.

  18. Forskolin-stimulated vasopressin and oxytocin release from the rat hypothalamo-neurohypophysial system in vitro is inhibited by melatonin.

    PubMed

    Roszczyk, Magdalena; Juszczak, Marlena

    2014-01-01

    Previous in vivo and in vitro studies have shown that melatonin changes vasopressin (AVP) and oxytocin (OT) secretion from the rat neurohypophysis. Additionally, melatonin is known to inhibit the forskolin-induced (forskolin is a strong adenylyl cyclase - AC activator) increase in cAMP accumulation in the rat pituitary. To determine whether the possible response of vasopressinergic and/or oxytocinergic neurones to melatonin could be mediated through a cAMP-dependent mechanism, the effect of different concentrations of melatonin (i.e. 10-11, 10-9, 10-7, 10-5 and 10-3 M) on forskolin-stimulated AVP and OT release from the rat hypothalamo-neurohypophysial (H-NH) system was studied in vitro. Male rats served as donors of the H-NH explants, which were placed in 1 mLof normal Krebs-Ringer fluid (nKRF), heated to 37oC and constantly gassed with carbogen (95% O2 and 5% CO2). The H-NH explants were incubated successively in nKRF {fluid B1} and incubation fluid as B1 enriched with an appropriate concentration of melatonin, i.e. 10-11 - 10-3 M and/or forskolin (at a concentration of 10-5 M) or their vehicles (0.1% ethanol or DMSO) {fluid B2}. After 20 min incubation in fluid B1 and next B2, the media were collected and immediately frozen before AVP and OT estimation by the RIA. The AVP and OT secretion was determined by using B2/B1 ratio for each H-NH explant. We have demonstrated that the highly effective AC activator - forskolin significantly stimulated both AVP and OT release from isolated rat H-NH system. Such an effect of forskolin was reduced by melatonin at concentrations of 10-9, 10-7 and 10-5 M. The strongest effect was exerted by this hormone at a concentration of 10-7 M, which inhibited not only forskolin-stimulated, but also basal, AVP and OT release. On the contrary, the highest studied concentration (i.e. 10-3 M) of melatonin stimulated both AVP and OT basal release, but when forskolin was present in the medium melatonin at such a concentration remained inactive

  19. Leucine Deprivation Stimulates Fat Loss via Increasing CRH Expression in the Hypothalamus and Activating The Sympathetic Nervous System

    PubMed Central

    Cheng, Ying; Zhang, Qian; Meng, Qingshu; Xia, Tingting; Huang, Zhiying; Wang, Chunxia; Liu, Bin; Chen, Shanghai; Xiao, Fei; Du, Ying

    2011-01-01

    We previously showed that leucine deprivation decreases abdominal fat mass largely by increasing energy expenditure, as demonstrated by increased lipolysis in white adipose tissue (WAT) and uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT). The goal of the present study was to investigate the possible involvement of central nervous system (CNS) in this regulation and elucidate underlying molecular mechanisms. For this purpose, levels of genes and proteins related to lipolysis in WAT and UCP1 expression in BAT were analyzed in wild-type mice after intracerebroventricular administration of leucine or corticotrophin-releasing hormone antibodies, or in mice deleted for three β-adrenergic receptors, after being maintained on a leucine-deficient diet for 7 d. Here, we show that intracerebroventricular administration of leucine significantly attenuates abdominal fat loss and blocks activation of hormone sensitive lipase in WAT and induction of UCP1 in BAT in leucine-deprived mice. Furthermore, we provide evidence that leucine deprivation stimulates fat loss by increasing expression of corticotrophin-releasing hormone in the hypothalamus via activation of stimulatory G protein/cAMP/protein kinase A/cAMP response element-binding protein pathway. Finally, we show that the effect of leucine deprivation on fat loss is mediated by activation of the sympathetic nervous system. These results suggest that CNS plays an important role in regulating fat loss under leucine deprivation and thereby provide novel and important insights concerning the importance of CNS leucine in the regulation of energy homeostasis. PMID:21719534

  20. Leucine deprivation stimulates fat loss via increasing CRH expression in the hypothalamus and activating the sympathetic nervous system.

    PubMed

    Cheng, Ying; Zhang, Qian; Meng, Qingshu; Xia, Tingting; Huang, Zhiying; Wang, Chunxia; Liu, Bin; Chen, Shanghai; Xiao, Fei; Du, Ying; Guo, Feifan

    2011-09-01

    We previously showed that leucine deprivation decreases abdominal fat mass largely by increasing energy expenditure, as demonstrated by increased lipolysis in white adipose tissue (WAT) and uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT). The goal of the present study was to investigate the possible involvement of central nervous system (CNS) in this regulation and elucidate underlying molecular mechanisms. For this purpose, levels of genes and proteins related to lipolysis in WAT and UCP1 expression in BAT were analyzed in wild-type mice after intracerebroventricular administration of leucine or corticotrophin-releasing hormone antibodies, or in mice deleted for three β-adrenergic receptors, after being maintained on a leucine-deficient diet for 7 d. Here, we show that intracerebroventricular administration of leucine significantly attenuates abdominal fat loss and blocks activation of hormone sensitive lipase in WAT and induction of UCP1 in BAT in leucine-deprived mice. Furthermore, we provide evidence that leucine deprivation stimulates fat loss by increasing expression of corticotrophin-releasing hormone in the hypothalamus via activation of stimulatory G protein/cAMP/protein kinase A/cAMP response element-binding protein pathway. Finally, we show that the effect of leucine deprivation on fat loss is mediated by activation of the sympathetic nervous system. These results suggest that CNS plays an important role in regulating fat loss under leucine deprivation and thereby provide novel and important insights concerning the importance of CNS leucine in the regulation of energy homeostasis.

  1. Normalization of sensorimotor integration by repetitive transcranial magnetic stimulation in cervical dystonia.

    PubMed

    Zittel, S; Helmich, R C; Demiralay, C; Münchau, A; Bäumer, T

    2015-08-01

    Previous studies indicated that sensorimotor integration and plasticity of the sensorimotor system are impaired in dystonia patients. We investigated motor evoked potential amplitudes and short latency afferent inhibition to examine corticospinal excitability and cortical sensorimotor integration, before and after inhibitory 1 Hz repetitive transcranial magnetic stimulation over primary sensory and primary motor cortex in patients with cervical dystonia (n = 12). Motor evoked potentials were recorded from the right first dorsal interosseous muscle after application of unconditioned transcranial magnetic test stimuli and after previous conditioning electrical stimulation of the right index finger at short interstimulus intervals of 25, 30 and 40 ms. Results were compared to a group of healthy age-matched controls. At baseline, motor evoked potential amplitudes did not differ between groups. Short latency afferent inhibition was reduced in cervical dystonia patients compared to healthy controls. Inhibitory 1 Hz sensory cortex repetitive transcranial magnetic stimulation but not motor cortex repetitive transcranial magnetic stimulation increased motor evoked potential amplitudes in cervical dystonia patients. Additionally, both 1 Hz repetitive transcranial magnetic stimulation over primary sensory and primary motor cortex normalized short latency afferent inhibition in these patients. In healthy subjects, sensory repetitive transcranial magnetic stimulation had no influence on motor evoked potential amplitudes and short latency afferent inhibition. Plasticity of sensorimotor circuits is altered in cervical dystonia patients.

  2. Gc protein-derived macrophage-activating factor (GcMAF) stimulates cAMP formation in human mononuclear cells and inhibits angiogenesis in chick embryo chorionallantoic membrane assay.

    PubMed

    Pacini, Stefania; Morucci, Gabriele; Punzi, Tiziana; Gulisano, Massimo; Ruggiero, Marco

    2011-04-01

    The effects of Gc protein-derived macrophage-activating factor (GcMAF) have been studied in cancer and other conditions where angiogenesis is deregulated. In this study, we demonstrate for the first time that the mitogenic response of human peripheral blood mononuclear cells (PBMCs) to GcMAF was associated with 3'-5'-cyclic adenosine monophosphate (cAMP) formation. The effect was dose dependent, and maximal stimulation was achieved using 0.1 ng/ml. Heparin inhibited the stimulatory effect of GcMAF on PBMCs. In addition, we demonstrate that GcMAF (1 ng/ml) inhibited prostaglandin E(1)- and human breast cancer cell-stimulated angiogenesis in chick embryo chorionallantoic membrane (CAM) assay. Finally, we tested different GcMAF preparations on CAM, and the assay proved to be a reliable, reproducible and inexpensive method to determine the relative potencies of different preparations and their stability; we observed that storage at room temperature for 15 days decreased GcMAF potency by about 50%. These data could prove useful for upcoming clinical trials on GcMAF.

  3. Stimulation of generation of inositol phosphates by carbamoylcholine and its inhibition by phorbol esters and iodide in dog thyroid cells.

    PubMed Central

    Laurent, E; Mockel, J; Takazawa, K; Erneux, C; Dumont, J E

    1989-01-01

    The action of carbamoylcholine (Cchol), NaF and other agonists on the generation of inositol phosphates (IPs) was studied in dog thyroid slices prelabelled with myo-[2-3H]inositol. The stimulation by Cchol (0.1 microM-0.1 mM) of IPs accumulation through activation of a muscarinic receptor [Graff, Mockel, Laurent, Erneux & Dumont (1987) FEBS Lett. 210, 204-210] was pertussis- and cholera-toxin insensitive. Ins(1,4,5)P3, Ins(1,3,4)P3 and InsP4 were generated. NaF (5-20 mM) also increased IPs generation (Graff et al., 1987); this effect was potentiated by AlCl3 (10 microM) and unaffected by pertussis toxin. Although phorbol dibutyrate (5 microM) abolished the cholinergic stimulation of IPs generation (Graff et al., 1987), it did not affect the fluoride-induced response. Cchol and NaF did not require extracellular Ca2+ to exert their effect, and neither KCl-induced membrane depolarization nor ionophore A23187 (10 microM) had any influence on basal IPs levels, or on cholinergic stimulation. However, more stringent Ca2+ depletion with EGTA (0.1 or 1 mM) decreased basal IPs levels as well as the amplitude of the stimulation by Cchol without abolishing it. Dibutyryl cyclic AMP, forskolin, cholera toxin and prostaglandin E1 had no effect on basal IPs levels and did not decrease the response to Cchol. Iodide (4 or 40 microM) also strongly decreased the cholinergic action on IPs, this inhibition being relieved by methimazole (1 mM). Our data suggest that Cchol activates a phospholipase C hydrolysing PtdIns(4,5)P2 in the dog thyroid cell in a cyclic AMP-independent manner. This activation requires no extracellular Ca2+ and depends on a GTP-binding protein insensitive to both cholera toxin and requires no extracellular Ca2+ and depends on a GTP-binding protein insensitive to both cholera toxin and pertussis toxin. The data are consistent with a rapid metabolism of Ins(1,4,5)P3 to Ins(1,3,4)P3 via the Ins(1,4,5)P3 3-kinase pathway, followed by dephosphorylation by a 5

  4. Toward the establishment of standardized in vitro tests for lipid-based formulations. 5. Lipolysis of representative formulations by gastric lipase.

    PubMed

    Bakala-N'Goma, Jean-Claude; Williams, Hywel D; Sassene, Philip J; Kleberg, Karen; Calderone, Marilyn; Jannin, Vincent; Igonin, Annabel; Partheil, Anette; Marchaud, Delphine; Jule, Eduardo; Vertommen, Jan; Maio, Mario; Blundell, Ross; Benameur, Hassan; Müllertz, Anette; Pouton, Colin W; Porter, Christopher J H; Carrière, Frédéric

    2015-04-01

    Lipid-based formulations (LBF) are substrates for digestive lipases and digestion can significantly alter their properties and potential to support drug absorption. LBFs have been widely examined for their behaviour in the presence of pancreatic enzymes. Here, the impact of gastric lipase on the digestion of representative formulations from the Lipid Formulation Classification System has been investigated. The pHstat technique was used to measure the lipolysis by recombinant dog gastric lipase (rDGL) of eight LBFs containing either medium (MC) or long (LC) chain triglycerides and a range of surfactants, at various pH values [1.5 to 7] representative of gastric and small intestine contents under both fasting and fed conditions. All LBFs were hydrolyzed by rDGL. The highest specific activities were measured at pH 4 with the type II and IIIA MC formulations that contained Tween®85 or Cremophor EL respectively. The maximum activity on LC formulations was recorded at pH 5 for the type IIIA-LC formulation. Direct measurement of LBF lipolysis using the pHstat, however, was limited by poor LC fatty acid ionization at low pH. Since gastric lipase initiates lipid digestion in the stomach, remains active in the intestine and acts on all representative LBFs, its implementation in future standardized in vitro assays may be beneficial. At this stage, however, routine use remains technically challenging.

  5. Activation of AMPK Inhibits Cholera Toxin Stimulated Chloride Secretion in Human and Murine Intestine

    PubMed Central

    Hoekstra, Nadia; Collins, Danielle; Collaco, Anne; Baird, Alan W.; Winter, Desmond C.; Ameen, Nadia; Geibel, John P.; Kopic, Sascha

    2013-01-01

    Increased intestinal chloride secretion through chloride channels, such as the cystic fibrosis transmembrane conductance regulator (CFTR), is one of the major molecular mechanisms underlying enterotoxigenic diarrhea. It has been demonstrated in the past that the intracellular energy sensing kinase, the AMP-activated protein kinase (AMPK), can inhibit CFTR opening. We hypothesized that pharmacological activation of AMPK can abrogate the increased chloride flux through CFTR occurring during cholera toxin (CTX) mediated diarrhea. Chloride efflux was measured in isolated rat colonic crypts using real-time fluorescence imaging. AICAR and metformin were used to activate AMPK in the presence of the secretagogues CTX or forskolin (FSK). In order to substantiate our findings on the whole tissue level, short-circuit current (SCC) was monitored in human and murine colonic mucosa using Ussing chambers. Furthermore, fluid accumulation was measured in excised intestinal loops. CTX and forskolin (FSK) significantly increased chloride efflux in isolated colonic crypts. The increase in chloride efflux could be offset by using the AMPK activators AICAR and metformin. In human and mouse mucosal sheets, CTX and FSK increased SCC. AICAR and metformin inhibited the secretagogue induced rise in SCC, thereby confirming the findings made in isolated crypts. Moreover, AICAR decreased CTX stimulated fluid accumulation in excised intestinal segments. The present study suggests that pharmacological activation of AMPK effectively reduces CTX mediated increases in intestinal chloride secretion, which is a key factor for intestinal water accumulation. AMPK activators may therefore represent a supplemental treatment strategy for acute diarrheal illness. PMID:23935921

  6. 3,4,5-Tricaffeoylquinic acid inhibits tumor necrosis factor-α-stimulated production of inflammatory mediators in keratinocytes via suppression of Akt- and NF-κB-pathways.

    PubMed

    Lee, Chung Soo; Lee, Seon Ae; Kim, Yun Jeong; Seo, Seong Jun; Lee, Min Won

    2011-11-01

    Keratinocytes may play an important role in the pathogenesis of skin disease in atopic dermatitis. Caffeoyl derivatives are demonstrated to have anti-inflammatory and anti-oxidant effects. However, the effect of 3,4,5-tricaffeoylquinic acid prepared from Aconium koreanum on the pro-inflammatory cytokine-stimulated keratinocyte responses remains uncertain. In human keratinocytes, we investigated the effect of 3,4,5-tricaffeoylquinic acid on the tumor necrosis factor (TNF)-α-stimulated production of inflammatory mediators in relation to the nuclear factor (NF)-κB and cell signaling Akt, which regulates the transcription genes involved in immune and inflammatory responses. 3,4,5-Tricaffeoylquinic acid inhibited the TNF-α-stimulated production of cytokines (IL-1β and IL-8) and chemokine (CCL17 and CCL27) in keratinocytes. Bay 11-7085 (an inhibitor of NF-κB activation) and Akt inhibitor attenuated the TNF-α-induced formation of inflammatory mediators. 3,4,5-Tricaffeoylquinic acid, Bay 11-7085, Akt inhibitor and N-acetylcysteine inhibited the TNF-α-induced activation of NF-κB, activation of Akt, and formation of reactive oxygen and nitrogen species. The results show that 3,4,5-tricaffeoylquinic acid seems to attenuate the TNF-α-stimulated inflammatory mediator production in keratinocytes by suppressing the activation of Akt and NF-κB pathways which may be mediated by reactive oxygen species. The findings suggest that 3,4,5-tricaffeoylquinic acid may exert an inhibitory effect against the pro-inflammatory mediator-induced skin disease. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Electrical stimulation of the rostral medial prefrontal cortex in rabbits inhibits the expression of conditioned eyelid responses but not their acquisition

    PubMed Central

    Leal-Campanario, Rocío; Fairén, Alfonso; Delgado-García, José M.; Gruart, Agnès

    2007-01-01

    We have studied the role of rostral medial prefrontal cortex (mPFC) on reflexively evoked blinks and on classically conditioned eyelid responses in alert-behaving rabbits. The rostral mPFC was identified by its afferent projections from the medial half of the thalamic mediodorsal nuclear complex. Classical conditioning consisted of a delay paradigm using a 370-ms tone as the conditioned stimulus (CS) and a 100-ms air puff directed at the left cornea as the unconditioned stimulus (US). The CS coterminated with the US. Electrical train stimulation of the contralateral rostral mPFC produced a significant inhibition of air-puff-evoked blinks. The same train stimulation of the rostral mPFC presented during the CS–US interval for 10 successive conditioning sessions significantly reduced the generation of conditioned responses (CRs) as compared with values reached by control animals. Interestingly, the percentage of CRs almost reached control values when train stimulation of the rostral mPFC was removed from the fifth conditioning session on. The electrical stimulation of the rostral mPFC in well conditioned animals produced a significant decrease in the percentage of CRs. Moreover, the stimulation of the rostral mPFC was also able to modify the kinematics (latency, amplitude, and velocity) of evoked CRs. These results suggest that the rostral mPFC is a potent inhibitor of reflexively evoked and classically conditioned eyeblinks but that activation prevents only the expression of CRs, not their latent acquisition. Functional and behavioral implications of this inhibitory role of the rostral mPFC are discussed. PMID:17592148

  8. Atrial natriuretic peptide regulates lipid mobilization and oxygen consumption in human adipocytes by activating AMPK

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Souza, Sandra C.; Chau, Mary D.L.; Yang, Qing

    2011-07-08

    Highlights: {yields} Treatment of differentiated human adipocytes with atrial natriuretic peptide (ANP) increased lipolysis and oxygen consumption by activating AMP-activated protein kinase (AMPK). {yields} ANP stimulated lipid mobilization by selective activation of the alpha2 subunit of AMPK and increased energy utilization through activation of both the alpha1 and alpha2 subunits of AMPK. {yields} ANP enhanced adipocyte mitochondrial oxidative capacity as evidenced by induction of oxidative mitochondrial genes and increase in oxygen consumption. {yields} Exposure of human adipocytes to fatty acids and (TNF{alpha}) induced insulin resistance and decreased expression of mitochondrial genes which was restored to normal by ANP. -- Abstract:more » Atrial natriuretic peptide (ANP) has been shown to regulate lipid and carbohydrate metabolism providing a possible link between cardiovascular function and metabolism by mediating the switch from carbohydrate to lipid mobilization and oxidation. ANP exerts a potent lipolytic effect via cGMP-dependent protein kinase (cGK)-I mediated-stimulation of AMP-activated protein kinase (AMPK). Activation of the ANP/cGK signaling cascade also promotes muscle mitochondrial biogenesis and fat oxidation. Here we demonstrate that ANP regulates lipid metabolism and oxygen utilization in differentiated human adipocytes by activating the alpha2 subunit of AMPK. ANP treatment increased lipolysis by seven fold and oxygen consumption by two fold, both of which were attenuated by inhibition of AMPK activity. ANP-induced lipolysis was shown to be mediated by the alpha2 subunit of AMPK as introduction of dominant-negative alpha2 subunit of AMPK attenuated ANP effects on lipolysis. ANP-induced activation of AMPK enhanced mitochondrial oxidative capacity as evidenced by a two fold increase in oxygen consumption and induction of mitochondrial genes, including carnitine palmitoyltransferase 1A (CPT1a) by 1.4-fold, cytochrome C (CytC) by 1.3-fold, and

  9. Role of arsenic exposure in adipose tissue dysfunction and its possible implication in diabetes pathophysiology.

    PubMed

    Renu, Kaviyarasi; Madhyastha, Harishkumar; Madhyastha, Radha; Maruyama, Masugi; Arunachlam, Sankarganesh; V G, Abilash

    2018-03-01

    Exposure to arsenic in drinking water can stimulate a diverse number of diseases that originate from impaired lipid metabolism in adipose and glucose metabolism, leading to insulin resistance. Arsenic inhibits differentiation of adipocyte and mediates insulin resistance with diminutive information on arsenicosis on lipid storage and lipolysis. This review focused on different mechanisms and pathways involved in adipogenesis and lipolysis in adipose tissue during arsenic-induced diabetes. Though arsenic is known to cause type2 diabetes through different mechanisms, the role of adipose tissue in causing type2 diabetes is still unclear. With the existing literature, this review exhibits the effect of arsenic on adipose tissue and its signalling events such as SIRT3- FOXO3a signalling pathway, Ras -MAP -AP-1 cascade, PI(3)-K-Akt pathway, endoplasmic reticulum stress protein, C/EBP homologous protein (CHOP10) and GPCR pathway with role of adipokines. There is a need to elucidate the different types of adipokines which are involved in arsenic-induced diabetes. The exhibited information brings to light that arsenic has negative effects on a white adipose tissue (WAT) by decreasing adipogenesis and enhancing lipolysis. Some of the epidemiological studies show that arsenic would causes obesity. Few studies indicate that arsenic might induces lipodystrophy condition. Further research is needed to evaluate the mechanistic link between arsenic and adipose tissue dysfunction which leads to insulin resistance. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Anti-inflammatory effects of physalin E from Physalis angulata on lipopolysaccharide-stimulated RAW 264.7 cells through inhibition of NF-κB pathway.

    PubMed

    Yang, Yan-Jun; Yi, Lang; Wang, Qing; Xie, Bing-Bing; Dong, Yan; Sha, Cong-Wei

    2017-04-01

    Physalin E is a naturally occurring seco-steroid isolated from the stems and aerial parts of Physalis angulata L. (Solanaceae). This study was aimed to explore the anti-inflammatory effects of physalin E on RAW 264.7 mouse macrophages stimulated by lipopolysaccharide (LPS) and the potential underlying mechanisms. The results showed that physalin E significantly inhibited LPS-induced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) expression and secretion in a dose-dependent manner. Unlike dexamethasone, these effects could not be blocked by miferstone (RU486). Meanwhile, physalin E reduced the degradation of I-kappa B protein in the cytoplasm and downregulated the nuclear factor-κB (NF-κB) p65 protein in the nuclear, which resulted in the inhibition of the NF-κB nuclear translocation. In conclusion, physalin E exerts its anti-inflammatory activities in LPS-induced macrophages. Physalin E can inhibit the production of inflammatory cytokines by targeting the NF-κB signaling pathway.

  11. Inhibition of basal and stimulated release of endothelin-1 from guinea pig tracheal epithelial cells in culture by beta 2-adrenoceptor agonists and cyclic AMP enhancers.

    PubMed

    Yang, Quan; Battistini, Bruno; Pelletier, Stéphane; Sirois, Pierre

    2007-10-01

    The effects of cyclic AMP-related compounds and beta adrenoceptor agonists on the basal and lipopolysaccharide (LPS)-stimulated release of endothelin-1 (ET-1) from guinea-pig tracheal epithelial cells (GPTEpCs) in culture were studied. Forskolin (a potent activator of adenylyl cyclase), 8-bromo-cyclic AMP (a cyclic AMP analogue), salbutamol and salmeterol (two beta 2-adrenoceptor agonists), were used to increase cyclic AMP levels. Cultured GPTEpCs released ET-1 continuously over a 24 h incubation period. The values reached 1,938 +/- 122 pg/mg of total cell proteins after 24 h. LPS (10 microg/ml) significantly stimulated the release of ET-1 by 1.6- to 1.8-fold, up to 1,262 +/- 56 pg/mg total cell proteins after an 8 h incubation period. Compound 8-bromo-cyclic AMP (10(-5), 10(-4) and 10(-3) M) reduced the basal release of ET-1 from GPTEpCs by up to 31% (P < 0.01) and the LPS stimulated release by up to 42% (P < 0.05), after an 8 h incubation period. Forskolin (10(-6), 10(-5) and 10(-4) M) also inhibited the basal release of ET-1 by up to 28% (P < 0.05) and LPS-stimulated release of ET-1 by up to 50% (P < 0.05), after an 8 h incubation period. At the concentration of 10(-5) M, forskolin increased cyclic AMP levels in GPTEpCs by 17-fold (P < 0.001) in the medium, 15 min after the beginning of the incubation. Salbutamol (10(-8) to 10(-6) M) had no effect on the basal production and release of ET-1 after 8 h. Conversely, this short acting beta 2-adrenoceptor agonist significantly reduced LPS-mediated increase of ET-1 production by up to 55% (P < 0.05) after an 8 h incubation period. Salmeterol (10(-9) M to 10(-5) M) inhibited basal and LPS-stimulated production and release of ET-1 after an 8 h incubation period (between 44 and 51%, P < 0.01). Both salbutamol and salmeterol (10(-6) M) increase cyclic AMP levels by five- and twofold, respectively (P < 0.05). In summary, these observations indicate that beta 2-adrenoceptor agonists or cyclic AMP enhancers can modulate both

  12. Sigma receptor ligand N,N'-di-(ortho-tolyl)guanidine inhibits release of acetylcholine in the guinea pig ileum.

    PubMed

    Cambell, B G; Keana, J F; Weber, E

    1991-11-26

    The inhibition of stimulated contractions of the guinea pig ileum longitudinal muscle/myenteric plexus preparation by sigma receptor ligands has been previously described. In this study, the stimulated release of [3H]acetylcholine from cholinergic nerve terminals in this same preparation was monitored in the presence and absence of sigma receptor ligands. N,N'-Di-(orthotolyl)guanidine (DTG) and other compounds selective for the sigma receptor inhibited stimulated [3H]acetylcholine release. These results suggest that their inhibition of stimulated contractions in this preparation was mediated by inhibition of acetylcholine release.

  13. Frontal transcranial direct current stimulation (tDCS) abolishes list-method directed forgetting.

    PubMed

    Silas, Jonathan; Brandt, Karen R

    2016-03-11

    It is a point of controversy as to whether directed forgetting effects are a result of active inhibition or a change of context initiated by the instruction to forget. In this study we test the causal role of active inhibition in directed forgetting. By applying cathodal transcranial direct current stimulation (tDCS) over the right prefrontal cortex we suppressed cortical activity commonly associated with inhibitory control. Participants who underwent real brain stimulation before completing the directed forgetting paradigm showed no directed forgetting effects. Conversely, those who underwent sham brain stimulation demonstrated classical directed forgetting effects. We argue that these findings suggest that inhibition is the primary mechanism that results in directed forgetting costs and benefits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. PPARbeta/delta agonist stimulates human lung carcinoma cell growth through inhibition of PTEN expression: the involvement of PI3K and NF-kappaB signals.

    PubMed

    Han, ShouWei; Ritzenthaler, Jeffrey D; Zheng, Ying; Roman, Jesse

    2008-06-01

    Recent studies suggest that activation of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) promotes cancer cell survival. We previously demonstrated that a selective PPARbeta/delta agonist, GW501516, stimulated human non-small cell lung carcinoma (NSCLC) cell growth. Here, we explore the mechanisms responsible for this effect. We show that GW501516 decreased phosphate and tensin homolog deleted on chromosome 10 (PTEN), a tumor suppressor known to decrease cell growth and induce apoptosis. Activation of PPARbeta/delta and phosphatidylinositol 3-kinase (PI3K)/Akt signaling was associated with inhibition of PTEN. GW501516 increased NF-kappaB DNA binding activity and p65 protein expression through activation of PPARbeta/delta and PI3K/Akt signals and enhanced the physical interactions between PPARbeta/delta and p65 protein. Conversely, inhibition of PI3K and silencing of p65 by small RNA interference (siRNA) blocked the effect of GW501516 on PTEN expression and on NSCLC cell proliferation. GW501516 also inhibited IKBalpha protein expression. Silencing of IKBalpha enhanced the effect of GW501516 on PTEN protein expression and on cell proliferation. It also augmented the GW501516-induced complex formation of PPARbeta/delta and p65 proteins. Overexpression of PTEN suppressed NSCLC cell growth and eliminated the effect of GW501516 on phosphorylation of Akt. Together, our observations suggest that GW501516 induces the proliferation of NSCLC cells by inhibiting the expression of PTEN through activation of PPARbeta/delta, which stimulates PI3K/Akt and NF-kappaB signaling. Overexpression of PTEN overcomes this effect and unveils PPARbeta/delta and PTEN as potential therapeutic targets in NSCLC.

  15. Inhibition of spinal reflexes by paramedian reticular nucleus.

    PubMed

    Chai, C Y; Lin, Y F; Wang, H Y; Wu, W C; Yen, C T; Kuo, J S; Wayner, M J

    1990-10-01

    The inhibitory actions of the paramedian reticular nucleus (PRN), and its neighbouring structures, i.e., midline raphe nuclei (MRN) and dorsal medullary depressor area (DMD) on the knee jerk (KnJ) and crossed extension movement (CEM) induced by central sciatic stimulation and on the L5 ventral root response (EVRR) evoked by central tibial stimulation, were studied in cats under urethane (400 mg/kg) and alpha-chloralose (40 mg/kg) anesthesia alone, IP or further paralyzed with atracurium besylate (0.5 mg/kg/30 min), IV. Electrical stimulation of the above areas with rectangular pulses (80 Hz, 1.0 msec, 100-200 microA) decreased systemic arterial blood pressure (SAP) in an average value of: 36 +/- 3 mmHg for PRN; 19 +/- 2 mmHg for MRN; and 23 +/- 3 mmHg for DMD. The KnJ and CEM were almost completely suppressed by simultaneous PRN stimulation. The EVRR, including mono- and polysynaptic spinal reflexes with transmission velocity from 10 to 60 m/sec or above, were also suppressed. MRN stimulation only inhibited the KnJ, CEM and polysynaptic spinal reflexes with transmission velocities between 25 and 60 m/sec, but facilitated spinal reflexes with conduction velocities below 10 m/sec. On the other hand, DMD stimulation resulted in small suppression of KnJ, CEM and inhibition of polysynaptic spinal reflexes with conduction velocities between 25 and 60 m/sec. Even though MRN and DMD partially inhibited polysynaptic spinal reflexes, the magnitude of such inhibition was much smaller than that produced by PRN (-20% and -22% vs. -48%). The above-mentioned PRN effects on SAP and EVRR persisted in chronic animals decerebellated 9-12 days before.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Mechanisms of inhibition in cat visual cortex.

    PubMed Central

    Berman, N J; Douglas, R J; Martin, K A; Whitteridge, D

    1991-01-01

    1. Neurones from layers 2-6 of the cat primary visual cortex were studied using extracellular and intracellular recordings made in vivo. The aim was to identify inhibitory events and determine whether they were associated with small or large (shunting) changes in the input conductance of the neurones. 2. Visual stimulation of subfields of simple receptive fields produced depolarizing or hyperpolarizing potentials that were associated with increased or decreased firing rates respectively. Hyperpolarizing potentials were small, 5 mV or less. In the same neurones, brief electrical stimulation of cortical afferents produced a characteristic sequence of a brief depolarization followed by a long-lasting (200-400 ms) hyperpolarization. 3. During the response to a stationary flashed bar, the synaptic activation increased the input conductance of the neurone by about 5-20%. Conductance changes of similar magnitude were obtained by electrically stimulating the neurone. Neurones stimulated with non-optimal orientations or directions of motion showed little change in input conductance. 4. These data indicate that while visually or electrically induced inhibition can be readily demonstrated in visual cortex, the inhibition is not associated with large sustained conductance changes. Thus a shunting or multiplicative inhibitory mechanism is not the principal mechanism of inhibition. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:1804983

  17. Inhibition of 5-HT neuron activity and induction of depressive-like behavior by high-frequency stimulation of the subthalamic nucleus.

    PubMed

    Temel, Yasin; Boothman, Laura J; Blokland, Arjan; Magill, Peter J; Steinbusch, Harry W M; Visser-Vandewalle, Veerle; Sharp, Trevor

    2007-10-23

    Bilateral, high-frequency stimulation (HFS) of the subthalamic nucleus (STN) is the surgical therapy of choice for movement disability in advanced Parkinson's disease (PD), but this procedure evokes debilitating psychiatric effects, including depressed mood, of unknown neural origin. Here, we report the unexpected finding that HFS of the STN inhibits midbrain 5-hydroxytryptamine (5-HT) neurons to evoke depression-related behavioral changes. We found that bilateral HFS of the STN consistently inhibited (40-50%) the firing rate of 5-HT neurons in the dorsal raphe nucleus of the rat, but not neighboring non-5-HT neurons. This effect was apparent at clinically relevant stimulation parameters (> or =100 Hz, > or =30 microA), was not elicited by HFS of either neighboring or remote structures to the STN, and was still present in rat models of PD. We also found that bilateral HFS of the STN evoked clear-cut, depressive-like behavior in a widely used experimental paradigm of depression (forced swim test), and this effect was also observed in a PD model. Importantly, the depressive-like behavior elicited by HFS of the STN was reversed by a selective 5-HT-enhancing antidepressant, thereby linking the behavioral change to decreased 5-HT neuronal activity. Overall, these findings link reduced 5-HT function to the psychiatric effects of HFS of the STN observed in PD patients and provide a rational basis for their clinical management. More generally, the powerful interaction between the STN and 5-HT system uncovered here offers insights into the high level of comorbidity of basal ganglia disease and mood disorder.

  18. Carnitine Palmitoyltransferase 1B 531K Allele Carriers Sustain a Higher Respiratory Quotient after Aerobic Exercise, but β3-Adrenoceptor 64R Allele Does Not Affect Lipolysis: A Human Model

    PubMed Central

    Gómez-Gómez, Eduardo; Ríos-Martínez, Martín Efrén; Castro-Rodríguez, Elena Margarita; Del-Toro-Equíhua, Mario; Ramírez-Flores, Mario; Delgado-Enciso, Ivan; Pérez-Huitimea, Ana Lilia; Baltazar-Rodríguez, Luz Margarita; Velasco-Pineda, Gilberto; Muñiz-Murguía, Jesús

    2014-01-01

    Carnitine palmitoyltransferase IB (CPT1B) and adrenoceptor beta-3 (ADRB3) are critical regulators of fat metabolism. CPT1B transports free acyl groups into mitochondria for oxidation, and ADRB3 triggers lipolysis in adipocytes, and their respective polymorphisms E531K and W64R have been identified as indicators of obesity in population studies. It is therefore important to understand the effects of these mutations on ADRB3 and CPT1B function in adipose and skeletal muscle tissue, respectively. This study aimed to analyze the rate of lipolysis of plasma indicators (glycerol, free fatty acids, and beta hydroxybutyrate) and fat oxidation (through the non-protein respiratory quotient). These parameters were measured in 37 participants during 30 min of aerobic exercise at approximately 62% of maximal oxygen uptake, followed by 30 min of recovery. During recovery, mean respiratory quotient values were higher in K allele carriers than in non-carriers, indicating low post-exercise fatty acid oxidation rates. No significant differences in lipolysis or lipid oxidation were observed between R and W allele carriers of ADRB3 at any time during the aerobic load. The substitution of glutamic acid at position 531 by lysine in the CPT1B protein decreases the mitochondrial beta-oxidation pathway, which increases the non-protein respiratory quotient value during recovery from exercise. This may contribute to weight gain or reduced weight-loss following exercise. PMID:24905907

  19. Modulation of GABA-stimulated chloride influx into membrane vesicles from rat cerebral cortex by triazolobenzodiazepines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Obata, T.; Yamamura, H.I.

    1988-01-01

    The effects of triazolobenzodiazepines of GABA-stimulated /sup 36/Cl/sup -/ uptake by membrane vesicles from rat cerebral cortex were examined. Triazolam and alprazolam showed a significant enhancement of GABA-stimulated /sup 36/Cl/sup -/ uptake at 0.01-10 uM. On the other hand, adinazolam showed a small enhancement at 0.1-1 uM followed by a significant inhibition of GABA-stimulated /sup 36/Cl/sup -/ uptake at 100 uM. The enhancement of GABA-stimulated /sup 36/Cl/sup -/ uptake by 1 uM alprazolam was antagonized by Ro15-1788, a benzodiazepine antagonist, but the inhibition of this response by 30 uM adinazolam was not antagonized by Ro15-1788. These results indicate that triazolobenzodiazepinesmore » enhanced GABA-stimulated /sup 36/Cl/sup -/ uptake through benzodiazepine receptors. High concentrations of adinazolam inhibit GABA-stimulated /sup 36/Cl/sup -/ uptake which may be due to the direct blockade of GABA-gated chloride channel. 23 references, 4 figures.« less

  20. Spilanthol Inhibits COX-2 and ICAM-1 Expression via Suppression of NF-κB and MAPK Signaling in Interleukin-1β-Stimulated Human Lung Epithelial Cells.

    PubMed

    Huang, Wen-Chung; Wu, Ling-Yu; Hu, Sindy; Wu, Shu-Ju

    2018-06-30

    Spilanthol a phytochemical derived from the Spilanthes acmella plant has antimicrobial, antioxidant, and anti-inflammatory properties. This study evaluated its effects on the expression of intercellular adhesion molecule 1 (ICAM-1) and inflammation-related mediators in IL-1β-stimulated human lung epithelial A549 cells. Human lung epithelial A549 cells were pretreated with various concentrations of spilanthol (3-100 μM) followed by treatment with IL-1β to induce inflammation. The protein levels of pro-inflammatory cytokines, chemokines, and prostaglandin E2 (PGE2) were measured using ELISA. Cyclooxygenase-2 (COX-2), heme oxygenase (HO-1), nuclear transcription factor kappa-B (NF-κB), and mitogen-activated protein kinase (MAPK) were measured by immunoblotting. The mRNA expression levels of ICAM-1 and MUC5AC were determined by real-time polymerase chain reaction. Spilanthol decreased the expression of PGE 2 , COX-2, TNF-α, and MCP-1. It also decreased ICAM-1 expression and suppressed monocyte adhesion to IL-1β-stimulated A549 cells. Spilanthol also significantly inhibited the phosphorylation of MAPK and I-κB. These results suggest that spilanthol exerts anti-inflammatory effects by inhibiting the expression of the pro-inflammatory cytokines, COX-2, and ICAM-1 by inhibiting the NF-κB and MAPK signaling pathways. Graphical Abstract ᅟ.

  1. Mouse IgA inhibits cell growth by stimulating tumor necrosis factor-alpha production and apoptosis of macrophage cell lines.

    PubMed

    Reljic, Rajko; Crawford, Carol; Challacombe, Stephen; Ivanyi, Juraj

    2004-04-01

    Potent Fcalpha-mediated actions of IgA have previously been shown for myeloid cells from man, but much less is known in relation to murine cells. Here, we report that mouse monoclonal IgA, irrespective of their antigenic specificity, inhibit the proliferation of mouse macrophage cell lines. The anti-proliferative activity was manifested by both monomeric and polymeric mouse IgA, but not by mouse monoclonal IgG and IgM. Growth of J774 cells was significantly inhibited during the 4-8 days of logarithmic growth, followed by a subsequent recovery of cell numbers prior to the stationary phase. We demonstrated that IgA binds to J774 cells, stimulates tumor necrosis factor (TNF)-alpha production and induces apoptosis which is not dependent on NO or FAS/CD95. We also demonstrated that IgA, in synergy with IFN-gamma, induced TNF-alpha production and apoptosis of thioglycollate-elicited mouse peritoneal macrophages. Thus, the in vitro actions of IgA described may also play a regulatory role for mouse macrophages in vivo.

  2. Epidermal growth factor stimulates mouse placental lactogen I but inhibits mouse placental lactogen II secretion in vitro.

    PubMed Central

    Yamaguchi, M; Ogren, L; Endo, H; Thordarson, G; Kensinger, R; Talamantes, F

    1992-01-01

    This study was undertaken to determine whether epidermal growth factor (EGF) regulates the secretion of mouse placental lactogen (mPL)-I and mPL-II. Primary cell cultures were prepared from placentas from days 7, 9, and 11 of pregnancy and cultured for up to 5 days. Addition of EGF (20 ng/ml) to the medium resulted in significant stimulation of mPL-I secretion by the second day of culture in cells from days 7 and 9 of pregnancy and significant inhibition of mPL-II secretion by the third or fourth day of culture in cells from days 7, 9, and 11. Dose-response studies carried out with cells from day 7 of pregnancy demonstrated that the minimum concentration of EGF that stimulated mPL-I secretion and inhibited mPL-II secretion was 1.0 ng/ml. EGF did not affect the DNA content of the cells or cell viability, assessed by trypan blue exclusion, nor did it have a general effect on protein synthesis. There are three types of PL-containing giant cells in mouse placental cell cultures: cells that contain either mPL-I or mPL-II and cells that contain both hormones. Immunocytochemical analysis and the reverse hemolytic plaque assay indicated that EGF treatment was accompanied by a significant increase in the number of cells that produce mPL-I, but among the PL cells that contained mPL-I, there was no change in the fraction of cells that contained only mPL-I or the fraction that contained both mPL-I and mPL-II. In contrast, EGF treatment did affect the distribution of mPL-II among PL cells. In control cultures, about 75% of the cells that contained mPL-II also contained mPL-I, but in EGF-treated cultures, all of the cells that contained mPL-II also contained mPL-I. These data suggest that EGF regulates mPL-I and mPL-II secretion at least partly by regulating PL cell differentiation. PMID:1454826

  3. Patterned sensory nerve stimulation enhances the reactivity of spinal Ia inhibitory interneurons.

    PubMed

    Kubota, Shinji; Hirano, Masato; Morishita, Takuya; Uehara, Kazumasa; Funase, Kozo

    2015-03-25

    Patterned sensory nerve stimulation has been shown to induce plastic changes in the reciprocal Ia inhibitory circuit. However, the mechanisms underlying these changes have not yet been elucidated in detail. The aim of the present study was to determine whether the reactivity of Ia inhibitory interneurons could be altered by patterned sensory nerve stimulation. The degree of reciprocal Ia inhibition, the conditioning effects of transcranial magnetic stimulation (TMS) on the soleus (SOL) muscle H-reflex, and the ratio of the maximum H-reflex amplitude versus maximum M-wave (H(max)/M(max)) were examined in 10 healthy individuals. Patterned electrical nerve stimulation was applied to the common peroneal nerve every 1 s (100 Hz-5 train) at the motor threshold intensity of tibialis anterior muscle to induce activity changes in the reciprocal Ia inhibitory circuit. Reciprocal Ia inhibition, the TMS-conditioned H-reflex amplitude, and H(max)/M(max) were recorded before, immediately after, and 15 min after the electrical stimulation. The patterned electrical nerve stimulation significantly increased the degree of reciprocal Ia inhibition and decreased the amplitude of the TMS-conditioned H-reflex in the short-latency inhibition phase, which was presumably mediated by Ia inhibitory interneurons. However, it had no effect on H(max)/M(max). Our results indicated that patterned sensory nerve stimulation could modulate the activity of Ia inhibitory interneurons, and this change may have been caused by the synaptic modification of Ia inhibitory interneuron terminals. These results may lead to a clearer understanding of the spinal cord synaptic plasticity produced by repetitive sensory inputs. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

  4. Rationalizing the selection of oral lipid based drug delivery systems by an in vitro dynamic lipolysis model for improved oral bioavailability of poorly water soluble drugs.

    PubMed

    Dahan, Arik; Hoffman, Amnon

    2008-07-02

    As a consequence of modern drug discovery techniques, there has been a consistent increase in the number of new pharmacologically active lipophilic compounds that are poorly water soluble. A great challenge facing the pharmaceutical scientist is making these molecules into orally administered medications with sufficient bioavailability. One of the most popular approaches to improve the oral bioavailability of these molecules is the utilization of a lipid based drug delivery system. Unfortunately, current development strategies in the area of lipid based delivery systems are mostly empirical. Hence, there is a need for a simplified in vitro method to guide the selection of a suitable lipidic vehicle composition and to rationalize the delivery system design. To address this need, a dynamic in vitro lipolysis model, which provides a very good simulation of the in vivo lipid digestion process, has been developed over the past few years. This model has been extensively used for in vitro assessment of different lipid based delivery systems, leading to enhanced understanding of the suitability of different lipids and surfactants as a delivery system for a given poorly water soluble drug candidate. A key goal in the development of the dynamic in vitro lipolysis model has been correlating the in vitro data of various drug-lipidic delivery system combinations to the resultant in vivo drug profile. In this paper, we discuss and review the need for this model, its underlying theory, practice and limitations, and the available data accumulated in the literature. Overall, the dynamic in vitro lipolysis model seems to provide highly useful initial guidelines in the development process of oral lipid based drug delivery systems for poorly water soluble drugs, and it predicts phenomena that occur in the pre-enterocyte stages of the intestinal absorption cascade.

  5. Cardiac effects produced by long-term stimulation of thoracic autonomic ganglia or nerves: implications for interneuronal interactions within the thoracic autonomic nervous system.

    PubMed

    Butler, C; Watson-Wright, W M; Wilkinson, M; Johnstone, D E; Armour, J A

    1988-03-01

    Electrical stimulation of an acutely decentralized stellate or middle cervical ganglion or cardiopulmonary nerve augments cardiac chronotropism or inotropism; as the stimulation continues there is a gradual reduction of this augmentation following the peak response, i.e., an inhibition of augmentation. The amount of this inhibition was found to be dependent upon the region of the heart investigated and the neural structure stimulated. The cardiac parameters which were augmented the most displayed the greatest inhibition. Maximum augmentation or inhibition occurred, in most instances, when 5-20 Hz stimuli were used. Inhibition of augmentation was overcome when the stimulation frequency was subsequently increased or following the administration of nicotine or tyramine, indicating that the inhibition was not primarily due to the lack of availability of noradrenaline in the nerve terminals of the efferent postganglionic sympathetic neurons. Furthermore, as infusions of isoproterenol or noradrenaline during the period of inhibition could still augment cardiac responses, whereas during the early peak responses they did not, the inhibition of augmentation does not appear to be due primarily to down regulation of cardiac myocyte beta-adrenergic receptors. The inhibition was modified by hexamethonium but not by phentolamine or atropine. Inhibition occurred when all ipsilateral cardiopulmonary nerves connected with acutely decentralized middle cervical and stellate ganglia were stimulated, whereas significant inhibition did not occur when these nerves were stimulated after they had been disconnected from the ipsilateral decentralized ganglia. Taken together these data indicate that the inhibition of cardiac augmentation which occurs during relatively long-term stimulation of intrathoracic sympathetic neural elements is due in large part to nicotinic cholinergic synaptic mechanisms that lie primarily in the major thoracic autonomic ganglia. They also indicate that long

  6. D2 dopamine receptor activation inhibits basal and forskolin-evoked acetylcholine release from dissociated striatal cholinergic interneurons.

    PubMed

    Login, I S

    1997-02-21

    We tested whether D2 ligands inhibit basal and forskolin-stimulated [3H]ACh release from dissociated striata, as opposed to striatal slices. Quinpirole inhibited both basal (40% maximal inhibition; IC50 approximately 50 nM) and 10 microM forskolin-stimulated release (80% inhibition; IC50 approximately 25 nM quinpirole) and both actions were blocked by a D2 antagonist. Vesamicol prevented the quinpirole and forskolin actions. The ability of D2 agonists to inhibit basal and cyclase-stimulated acetylcholine release emanating from vesamicol-sensitive vesicles appears to be tonically suppressed by inhibitory elements within striatal circuitry.

  7. PhCESA3 silencing inhibits elongation and stimulates radial expansion in petunia.

    PubMed

    Yang, Weiyuan; Cai, Yuanping; Hu, Li; Wei, Qian; Chen, Guoju; Bai, Mei; Wu, Hong; Liu, Juanxu; Yu, Yixun

    2017-02-02

    Cellulose synthase catalytic subunits (CESAs) play important roles in plant growth, development and disease resistance. Previous studies have shown an essential role of Arabidopsis thaliana CESA3 in plant growth. However, little is known about the role of CESA3 in species other than A. thaliana. To gain a better understanding of CESA3, the petunia (Petunia hybrida) PhCESA3 gene was isolated, and the role of PhCESA3 in plant growth was analyzed in a wide range of plants. PhCESA3 mRNA was present at varying levels in tissues examined. VIGS-mediated PhCESA3 silencing resulted in dwarfing of plant height, which was consistent with the phenotype of the A. thaliana rsw1 mutant (a temperature-sensitive allele of AtCESA1), the A. thaliana cev1 mutant (the AtCESA3 mild mutant), and the antisense AtCESA3 line. However, PhCESA3 silencing led to swollen stems, pedicels, filaments, styles and epidermal hairs as well as thickened leaves and corollas, which were not observed in the A. thaliana cev1 mutant, the rsw1 mutant and the antisense AtCESA3 line. Further micrographs showed that PhCESA3 silencing reduced the length and increased the width of cells, suggesting that PhCESA3 silencing inhibits elongation and stimulates radial expansion in petunia.

  8. PhCESA3 silencing inhibits elongation and stimulates radial expansion in petunia

    PubMed Central

    Yang, Weiyuan; Cai, Yuanping; Hu, Li; Wei, Qian; Chen, Guoju; Bai, Mei; Wu, Hong; Liu, Juanxu; Yu, Yixun

    2017-01-01

    Cellulose synthase catalytic subunits (CESAs) play important roles in plant growth, development and disease resistance. Previous studies have shown an essential role of Arabidopsis thaliana CESA3 in plant growth. However, little is known about the role of CESA3 in species other than A. thaliana. To gain a better understanding of CESA3, the petunia (Petunia hybrida) PhCESA3 gene was isolated, and the role of PhCESA3 in plant growth was analyzed in a wide range of plants. PhCESA3 mRNA was present at varying levels in tissues examined. VIGS-mediated PhCESA3 silencing resulted in dwarfing of plant height, which was consistent with the phenotype of the A. thaliana rsw1 mutant (a temperature-sensitive allele of AtCESA1), the A. thaliana cev1 mutant (the AtCESA3 mild mutant), and the antisense AtCESA3 line. However, PhCESA3 silencing led to swollen stems, pedicels, filaments, styles and epidermal hairs as well as thickened leaves and corollas, which were not observed in the A. thaliana cev1 mutant, the rsw1 mutant and the antisense AtCESA3 line. Further micrographs showed that PhCESA3 silencing reduced the length and increased the width of cells, suggesting that PhCESA3 silencing inhibits elongation and stimulates radial expansion in petunia. PMID:28150693

  9. Inhibition of myosin light-chain phosphorylation inverts the birefringence response of porcine airway smooth muscle

    PubMed Central

    Smolensky, Alexander V; Gilbert, Susan H; Harger-Allen, Margaret; Ford, Lincoln E

    2007-01-01

    Muscle birefringence, caused mainly by parallel thick filaments, increases in smooth muscle during stimulation, signalling thick filament formation upon activation. The reverse occurs in skeletal muscle, where a decrease in birefringence has been correlated with crossbridge movement away from the thick filaments. When force generation by trachealis muscle was inhibited with wortmannin, which inhibits myosin light-chain phosphorylation and thick-filament formation, but not the calcium increase caused by stimulation, the birefringence response inverted, suggesting crossbridge movement similar to that of skeletal muscle. Resistance to quick stretches was much greater in stimulated muscle than in unstimulated muscle before wortmannin treatment and no different in stimulated and unstimulated muscle after force inhibition by wortmannin. Before wortmannin treatment, stimulation reduced thick-filament cross-sectional areas in electron micrographs by 44%. After force inhibition by wortmannin, filament areas were not significantly different in stimulated and unstimulated muscle and not significantly different from those of relaxed muscle without wortmannin treatment. These results suggest that myofibrillar-space calcium causes crossbridges to move away from the thick filaments without firmly attaching to thin filaments. PMID:17095560

  10. Lipolysis of the semi-solid self-emulsifying excipient Gelucire 44/14 by digestive lipases.

    PubMed

    Fernandez, Sylvie; Rodier, Jean-David; Ritter, Nicolas; Mahler, Bruno; Demarne, Frédéric; Carrière, Frédéric; Jannin, Vincent

    2008-08-01

    Gelucire 44/14 is a semi-solid self-emulsifying excipient used for the oral delivery of poorly water-soluble drugs. It is composed of C8-C18 acylglycerols and PEG-32 esters, all of which are potential substrates for digestive lipases. Here we studied the lipolysis of Gelucire 44/14 by porcine pancreatic extracts, human pancreatic juice and several purified digestive lipases. Human pancreatic lipase (HPL), the main lipase involved in the digestion of triacylglycerols, did not show any significant activity on Gelucire 44/14 or on either of its individual compounds, C8-C18 acylglycerols and PEG-32 esters. Other pancreatic lipases such as human pancreatic lipase-related protein 2 (HPLRP2) showed low activity on Gelucire 44/14 although the highest activity of HPLRP2 was that observed on the C8-C18 acylglycerol fraction, which accounts for 20% (w/w) of Gelucire 44/14. In addition, HPLRP2 showed low activities on the PEG-32 esters, whether these were tested individually or mixed together. Carboxyl ester hydrolase (CEH) showed high activity on Gelucire 44/14, and the highest activities of CEH were those recorded on the total PEG-32 ester fraction and on each individual PEG-32 ester, except for PEG-32 monostearate. The highest activity of all the enzymes tested was that of dog gastric lipase (DGL) on Gelucire 44/14, although DGL showed low activity on the PEG-32 ester fraction and on each individual PEG-32 ester. We compared the lipolysis of Gelucire 44/14 with that of Labrasol, another self-emulsifying excipient, which is liquid at room temperature. Human pancreatic juice showed similar rates of activity on both Gelucire 44/14 and Labrasol. This finding means that these excipients are hydrolyzed in vivo during pancreatic digestion, mainly by CEH in the case of Gelucire 44/14 and by both HPLRP2 and CEH in that of Labrasol, whereas HPL showed very low activities on each of these two excipients. This is the first time the effects of PEG and acyl chain length on the lipolytic

  11. Montmorillonite-lipid hybrid carriers for ionizable and neutral poorly water-soluble drugs: Formulation, characterization and in vitro lipolysis studies.

    PubMed

    Dening, Tahnee J; Rao, Shasha; Thomas, Nicky; Prestidge, Clive A

    2017-06-30

    Lipid-based formulations (LBFs) are a popular strategy for enhancing the gastrointestinal solubilization and absorption of poorly water-soluble drugs. In light of this, montmorillonite-lipid hybrid (MLH) particles, composed of medium-chain triglycerides, lecithin and montmorillonite clay platelets, have been developed as a novel solid-state LBF. Owing to the unique charge properties of montmorillonite, whereby the clay platelet surfaces carry a permanent negative charge and the platelet edges carry a pH-dependent charge, three model poorly water-soluble drugs with different charge properties; blonanserin (weak base, pKa 7.7), ibuprofen (weak acid, pKa 4.5) and fenofibrate (neutral), were formulated as MLH particles and their performance during biorelevant in vitro lipolysis at pH 7.5 was investigated. For blonanserin, drug solubilization during in vitro lipolysis was significantly reduced 3.4-fold and 3.2-fold for MLH particles in comparison to a control lipid solution and silica-lipid hybrid (SLH) particles, respectively. It was hypothesized that strong electrostatic interactions between the anionic montmorillonite platelet surfaces and cationic blonanserin molecules were responsible for the inferior performance of MLH particles. In contrast, no significant influence on drug solubilization was observed for ibuprofen- and fenofibrate-loaded MLH particles. The results of the current study indicate that whilst MLH particles are a promising novel formulation strategy for poorly water-soluble drugs, drug ionization tendency and the potential for drug-clay interactions must be taken into consideration to ensure an appropriate performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Comparison of lipases for in vitro models of gastric digestion: lipolysis using two infant formulas as model substrates.

    PubMed

    Sassene, P J; Fanø, M; Mu, H; Rades, T; Aquistapace, S; Schmitt, B; Cruz-Hernandez, C; Wooster, T J; Müllertz, A

    2016-09-14

    The aim of this study was to find a lipase suitable as a surrogate for Human Gastric Lipase (HGL), since the development of predictive gastrointestinal lipolysis models are hampered by the lack of a lipase with similar digestive properties as HGL. Three potential surrogates for HGL; Rhizopus Oryzae Lipase (ROL), Rabbit Gastric Lipase (RGL) and recombinant HGL (rHGL), were used to catalyze the in vitro digestion of two infant formulas (a medium-chain triacylglyceride enriched formula (MC-IF) and a predominantly long-chain triacylglyceride formula (LC-IF)). Digesta were withdrawn after 0, 5, 15, 30, 60 min of gastric digestion and after 90 or 180 min of intestinal digestion with or without the presence of pancreatic enzymes, respectively. The digesta were analyzed by scanning electron microscopy and gas chromatography to quantify the release of fatty acids (FAs). Digestions of both formulas, catalyzed by ROL, showed that the extent of gastric digestion was higher than expected from previously published in vivo data. ROL was furthermore insensitive to FA chain length and all FAs were released at the same pace. RGL and rHGL favoured the release of MC-FAs in both formulas, but rHGL did also release some LC-FAs during digestion of MC-IF, whereas RGL only released MC-FAs. Digestion of a MC-IF by HGL in vivo showed that MC-FAs are preferentially released, but some LC-FAs are also released. Thus of the tested lipase rHGL replicated the digestive properties of HGL the best and is a suitable surrogate for HGL for use in in vitro gastrointestinal lipolysis models.

  13. Lipolysis and proteolysis profiles of fresh artisanal goat cheese made with raw milk with 3 different fat contents.

    PubMed

    Sánchez-Macías, D; Morales-Delanuez, A; Moreno-Indias, I; Hernández-Castellano, L E; Mendoza-Grimón, V; Castro, N; Argüello, A

    2011-12-01

    The objective of this study was to describe the proteolysis and lipolysis profiles in goat cheese made in the Canary Islands (Spain) using raw milk with 3 different fat contents (0.5, 1.5, and 5%) and ripened for 1, 7, 14, and 28 d. β-Casein was the most abundant protein in all cheeses and at all ripening times. Quantitative analysis showed a general decrease in caseins as ripening progressed, and degradation rates were higher for α(S1)-casein than for β-casein and α(S2)-casein. Furthermore, the degradation rate during the experimental time decreased with lower fat contents. The α(S2)-casein and α(S1)-casein levels that remained in full-fat and reduced-fat cheeses were less than those in low-fat cheese. In contrast, β-casein also showed degradation along with ripening, but differences in degradation among the 3 cheese types were not significant at 28 d. The degradation products increased with the ripening time in all cheeses, but they were higher in full-fat cheese than in reduced-fat and low-fat cheeses. The free fatty acid concentration per 100g of cheese was higher in full-fat cheese than in reduced- and low-fat cheese; however, when the results were expressed as milligrams of free fatty acids per gram of fat in cheese, then lipolysis occurred more rapidly in low-fat cheese than in reduced- and full-fat cheeses. These results may explain the atypical texture and off-flavors found in low-fat goat cheeses, likely the main causes of non-acceptance. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Anodal transcranial direct current stimulation of right temporoparietal area inhibits self-recognition.

    PubMed

    Payne, Sophie; Tsakiris, Manos

    2017-02-01

    Self-other discrimination is a crucial mechanism for social cognition. Neuroimaging and neurostimulation research has pointed to the involvement of the right temporoparietal region in a variety of self-other discrimination tasks. Although repetitive transcranial magnetic stimulation over the right temporoparietal area has been shown to disrupt self-other discrimination in face-recognition tasks, no research has investigated the effect of increasing the cortical excitability in this region on self-other face discrimination. Here we used transcranial direct current stimulation (tDCS) to investigate changes in self-other discrimination with a video-morphing task in which the participant's face morphed into, or out of, a familiar other's face. The task was performed before and after 20 min of tDCS targeting the right temporoparietal area (anodal, cathodal, or sham stimulation). Differences in task performance following stimulation were taken to indicate a change in self-other discrimination. Following anodal stimulation only, we observed a significant increase in the amount of self-face needed to distinguish between self and other. The findings are discussed in relation to the control of self and other representations and to domain-general theories of social cognition.

  15. Magnesium Reduces Hepatic Lipid Accumulation in Yellow Catfish (Pelteobagrus fulvidraco) and Modulates Lipogenesis and Lipolysis via PPARA, JAK-STAT, and AMPK Pathways in Hepatocytes.

    PubMed

    Wei, Chuan-Chuan; Wu, Kun; Gao, Yan; Zhang, Li-Han; Li, Dan-Dan; Luo, Zhi

    2017-06-01

    accumulation in yellow catfish and the variation might be attributed to inhibited lipogenesis and increased lipolysis. PPARA, JAK-STAT, and AMPK pathways mediated the magnesium-induced changes in lipid deposition and metabolism. These results offer new insight into magnesium nutrition in vertebrates. © 2017 American Society for Nutrition.

  16. Response Inhibition Impairments Predict Alcohol-Induced Sedation

    PubMed Central

    Shannon, Erin E.; Staniforth, Elizabeth R.; McNamara, Juliette; Bernosky-Smith, Kimberly A.; Liguori, Anthony

    2011-01-01

    Aims: The aim of this study was to probe the relationship between the subjective effects of alcohol and impulsive behavior in social drinkers. Methods: Fifty social drinkers performed a response-inhibition task before consuming alcohol. A 0.8-g/kg dose of alcohol was administered in a binge-like fashion (0.2 g/kg every 30 min) to the participants over a 2-h time period. Participants then completed questionnaires measuring stimulation, sedation and mood following consumption of alcohol. Linear regression analyses were performed by examining the relationship between performance on the response inhibition impulsivity task and subjective responses to alcohol (i.e. stimulation, sedation and arousal). Results: There was a significant positive relationship found between impulsive responding and self-reported sedation following alcohol consumption. Additionally, there was a significant negative relationship between behavioral impulsivity and self-reported stimulation and arousal following alcohol consumption. Conclusion: These results suggest that higher levels of impulsivity are associated with experiencing greater sedating than stimulating effects of alcohol. Individuals with high levels of impulsivity may be less sensitive to the stimulating effects of a specified dose of alcohol, which could lead to these individuals consuming more alcohol to experience the stimulating effects of alcohol. PMID:21127353

  17. Thrombin-stimulated platelet aggregation is inhibited by kallikrein in a time- and concentration-dependent manner.

    PubMed

    Veloso, D

    2003-01-01

    Many in vitro studies have shown that activation of prekallikrein (PK) to kallikrein (KAL) in normal plasma triggers rapid activation of the coagulation cascade. In agreement, the coagulation activation is impaired in PK-deficient plasma. Paradoxically, PK-deficient patients show a tendency to thrombosis. To investigate the discrepancy between the in vitro and in vivo findings, we analyzed the effect of KAL on the rate of platelet aggregation. For this research, physiologic concentrations of washed human platelets were incubated for 5 and/or 10 min with approximately 2.2 to 88 nM human plasma KAL (< 1/100 to approximately 1/3 of PK concentrations in plasma) prior to the addition of high concentrations of alpha-thrombin (54 nM) or fibrinogen plus ADP. KAL concentrations were arbitrarily selected on the assumption that concentrations of free KAL (the enzymatically active species) were minute in normal plasma and higher when KAL production was enhanced, and/or inhibitors were depleted. Full platelet aggregation was that seen in the absence of KAL or PK. Inhibition of platelet aggregation stimulated by thrombin was markedly increased with increased KAL concentrations and incubation times. The degree of inhibition by KAL was smaller when ADP was the agonist. The data suggest that KAL may play a role in the modulation of platelet aggregation in vivo under normal conditions as well as when prolonged, high concentrations of KAL occur in blood. The data may also help to explain the intriguing observation that PK-deficient patients show a tendency to thrombotic episodes and myocardial infarction whereas in vitro assays predict bleeding.

  18. Burn Eschar Stimulates Fibroblast and Adipose Mesenchymal Stromal Cell Proliferation and Migration but Inhibits Endothelial Cell Sprouting

    PubMed Central

    Monsuur, Hanneke N.; van den Broek, Lenie J.; Jhingoerie, Renushka L.; Vloemans, Adrianus F. P. M.

    2017-01-01

    The majority of full-thickness burn wounds heal with hypertrophic scar formation. Burn eschar most probably influences early burn wound healing, since granulation tissue only forms after escharotomy. In order to investigate the effect of burn eschar on delayed granulation tissue formation, burn wound extract (BWE) was isolated from the interface between non-viable eschar and viable tissue. The influence of BWE on the activity of endothelial cells derived from dermis and adipose tissue, dermal fibroblasts and adipose tissue-derived mesenchymal stromal cells (ASC) was determined. It was found that BWE stimulated endothelial cell inflammatory cytokine (CXCL8, IL-6 and CCL2) secretion and migration. However, BWE had no effect on endothelial cell proliferation or angiogenic sprouting. Indeed, BWE inhibited basic Fibroblast Growth Factor (bFGF) induced endothelial cell proliferation and sprouting. In contrast, BWE stimulated fibroblast and ASC proliferation and migration. No difference was observed between cells isolated from dermis or adipose tissue. The inhibitory effect of BWE on bFGF-induced endothelial proliferation and sprouting would explain why excessive granulation tissue formation is prevented in full-thickness burn wounds as long as the eschar is still present. Identifying the eschar factors responsible for this might give indications for therapeutic targets aimed at reducing hypertrophic scar formation which is initiated by excessive granulation tissue formation once eschar is removed. PMID:28820426

  19. Modulating behavioral inhibition by tDCS combined with cognitive training.

    PubMed

    Ditye, Thomas; Jacobson, Liron; Walsh, Vincent; Lavidor, Michal

    2012-06-01

    Cognitive training is an effective tool to improve a variety of cognitive functions, and a small number of studies have now shown that brain stimulation accompanying these training protocols can enhance their effects. In the domain of behavioral inhibition, little is known about how training can affect this skill. As for transcranial direct current stimulation (tDCS), it was previously found that stimulation over the right inferior frontal gyrus (rIFG) facilitates behavioral inhibition performance and modulates its electrophysiological correlates. This study aimed to investigate this behavioral facilitation in the context of a learning paradigm by giving tDCS over rIFG repetitively over four consecutive days of training on a behavioral inhibition task (stop signal task (SST)). Twenty-two participants took part; ten participants were assigned to receive anodal tDCS (1.5 mA, 15 min), 12 were assigned to receive training but not active stimulation. There was a significant effect of training on learning and performance in the SST, and the integration of the training and rIFG-tDCS produced a more linear learning slope. Better performance was also found in the active stimulation group. Our findings show that tDCS-combined cognitive training is an effective tool for improving the ability to inhibit responses. The current study could constitute a step toward the use of tDCS and cognitive training as a therapeutic tool for cognitive control impairments in conditions such as attention-deficit hyperactivity disorder (ADHD) or schizophrenia.

  20. Glyceroneogenesis is inhibited through HIV protease inhibitor-induced inflammation in human subcutaneous but not visceral adipose tissue

    PubMed Central

    Leroyer, Stéphanie; Vatier, Camille; Kadiri, Sarah; Quette, Joëlle; Chapron, Charles; Capeau, Jacqueline; Antoine, Bénédicte

    2011-01-01

    Glyceroneogenesis, a metabolic pathway that participates during lipolysis in the recycling of free fatty acids to triglycerides into adipocytes, contributes to the lipid-buffering function of adipose tissue. We investigated whether glyceroneogenesis could be affected by human immunodeficiency virus (HIV) protease inhibitors (PIs) responsible or not for dyslipidemia in HIV-infected patients. We treated explants obtained from subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) depots from lean individuals. We observed that the dyslipidemic PIs nelfinavir, lopinavir and ritonavir, but not the lipid-neutral PI atazanavir, increased lipolysis and decreased glyceroneogenesis, leading to an increased release of fatty acids from SAT but not from VAT. At the same time, dyslipidemic PIs decreased the amount of perilipin and increased interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) secretion in SAT but not in VAT. Parthenolide, an inhibitor of the NFκB pathway, counteracted PI-induced increased inflammation and decreased glyceroneogenesis. IL-6 (100 ng) inhibited the activity of phosphoenolpyruvate carboxykinase, the key enzyme of glyceroneogenesis, in SAT but not in VAT. Our data show that dyslipidemic but not lipid-neutral PIs decreased glyceroneogenesis as a consequence of PI-induced increased inflammation in SAT that could have an affect on adipocytes and/or macrophages. These results add a new link between fat inflammation and increased fatty acids release and suggest a greater sensitivity of SAT than VAT to PI-induced inflammation. PMID:21068005

  1. Myelin-induced inhibition in a spiral ganglion organ culture - Approaching a natural environment in vitro.

    PubMed

    Kramer, Benedikt; Tropitzsch, Anke; Müller, Marcus; Löwenheim, Hubert

    2017-08-15

    The performance of a cochlear implant depends on the defined interaction between afferent neurons of the spiral ganglion and the inserted electrode. Neurite outgrowth can be induced by neurotrophins such as brain-derived neurotrophic factor (BDNF) via tropomyosin kinase receptor B (TrkB). However, neurotrophin signaling through the p75 neurotrophin receptor (p75) inhibits neurite outgrowth in the presence of myelin. Organotypic cultures derived from postnatal (P3-5) mice were used to study myelin-induced inhibition in the cochlear spiral ganglion. Neurite outgrowth was analyzed and quantified utilizing an adapted Sholl analysis. Stimulation of neurite outgrowth was quantified after application of BDNF, the selective TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) and a selective inhibitor of the Rho-associated kinase (Y27632), which inhibits the p75 pathway. Myelin-induced inhibition was assessed by application of myelin-associated glycoprotein (MAG-Fc) to stimulate the inhibitory p75 pathway. Inhibition of neurite outgrowth was achieved by the selective TrkB inhibitor K252a. Stimulation of neurite outgrowth was observed after treatment with BDNF, 7,8 DHF and a combination of BDNF and Y27632. The 7,8-DHF-induced growth effects could be inhibited by K252a. Furthermore, inhibition of neurite outgrowth was observed after supplementation with MAG-Fc. Myelin-induced inhibition could be overcome by 7,8-DHF and the combination of BDNF and Y27632. In this study, myelin-induced inhibition of neurite outgrowth was established in a spiral ganglion model. We reveal that 7,8-DHF is a viable novel compound for the stimulation of neurite outgrowth in a myelin-induced inhibitory environment. The combination of TrkB stimulation and ROCK inhibition can be used to overcome myelin inhibition. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Mitochondrial-derived hydrogen peroxide inhibits relaxation of bovine coronary arterial smooth muscle to hypoxia through stimulation of ERK MAP kinase.

    PubMed

    Gao, Qun; Zhao, Xiangmin; Ahmad, Mansoor; Wolin, Michael S

    2009-12-01

    Mitochondrial reactive oxygen species (ROS) are potentially important in vascular oxygen-sensing mechanisms because hypoxia appears to be a stimulus for mitochondrial ROS generation; however, scavenging of endogenous ROS does not alter relaxation of endothelium-denuded bovine coronary arteries (BCA) to hypoxia. The purpose of this study was to investigate the influence of increasing mitochondrial ROS on the relaxation of BCA to hypoxia. Increasing mitochondrial superoxide with inhibitors of electron transport (10 microM rotenone and antimycin) and by opening mitochondrial ATP-dependent K+ channels with 100 microM diazoxide were observed in this study to attenuate relaxation of BCA precontracted with 30 mM KCl to hypoxia by 68-76% and 38%, respectively. This effect of rotenone is not prevented by inhibiting NADPH oxidase (Nox) activation or scavenging superoxide with Peg-SOD; however, it is reversed 85% and 26% by increasing the consumption of intracellular peroxide by 0.1 mM ebselen and 32.5 U/ml Peg-catalase. Because inhibition of extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase (10 microM PD-98059), but not src kinase or rho kinase, also reverses the effects of rotenone by 69%, the peroxide-elicited force-enhancing effects of ERK appear to be attenuating the response to hypoxia. Rotenone increased the phosphorylation of ERK (by 163%). Activation of ERK in BCA with 0.1 mM peroxide or endogenous peroxide generated by stimulating Nox2 with a stretch treatment or contraction with 100 nM U-46619 also attenuated relaxation to hypoxia. Thus coronary arterial relaxation to hypoxia may be attenuated by pathophysiological conditions associated with increased peroxide generation by mitochondria or other sources that stimulate ERK.

  3. Alisol A 24-acetate ameliorates nonalcoholic steatohepatitis by inhibiting oxidative stress and stimulating autophagy through the AMPK/mTOR pathway.

    PubMed

    Wu, Chenqu; Jing, Menghui; Yang, Lijuan; Jin, Lei; Ding, Yicun; Lu, Juan; Cao, Qin; Jiang, Yuanye

    2018-06-05

    Alisol A 24-acetate (AA), a natural triterpenoid isolated from the traditional Chinese medicine Rhizoma Alismatis, has various therapeutic effects. We investigated the anti-nonalcoholic steatohepatitis (NASH) effect of AA and its underlying mechanisms in vitro and in vivo. C57BL/6 mice were fed a methionine and choline-deficient (MCD) diet for 4 weeks to induce NASH. The mice were simultaneously treated with a daily dose of AA (15, 30, and 60 mg kg -1 , ig) for 4 weeks. On the last day, the animals were sacrificed and plasma and liver tissue were collected. Serum and liver tissue biochemical analyses and histological observation were performed. The human hepatic stellate cell line LX-2 was used to build NASH models by culturing with conditioned medium from WRL-68 liver cells after exposure to MCD medium in vitro. Liver oxidative stress and inflammatory indices and autophagy markers were examined. The results showed that AA suppressed reactive oxygen species (ROS) and inflammation in a NASH mouse model and inhibited the expression of inflammatory cytokines and ROS in LX-2 cells in MCD medium. Furthermore, we found AA stimulated autophagy in mice liver and LX-2, which could be the underlying mechanism of AA in NASH. To further investigate the role of autophagy in LX-2 cells, we found that AA regulated autophagy via the AMPK/mTOR/ULK1 pathway and dorsomorphin, a selective AMPK inhibitor, led to the suppression of AA-induced autophagy. Taken together, our results indicate that AA could be a possible therapy for NASH by inhibiting oxidative stress and stimulating autophagy. Copyright © 2018. Published by Elsevier B.V.

  4. Deep Brain Stimulation of the Internal Globus Pallidus Improves Response Initiation and Proactive Inhibition in Patients With Parkinson’s Disease

    PubMed Central

    Pan, Yixin; Wang, Linbin; Zhang, Yingying; Zhang, Chencheng; Qiu, Xian; Tan, Yuyan; Zhou, Haiyan; Sun, Bomin; Li, Dianyou

    2018-01-01

    Background: Impulse control disorder is not uncommon in patients with Parkinson’s disease (PD) who are treated with dopamine replacement therapy and subthalamic deep brain stimulation (DBS). Internal globus pallidus (GPi)-DBS is increasingly used, but its role in inhibitory control has rarely been explored. In this study, we evaluated the effect of GPi-DBS on inhibitory control in PD patients. Methods: A stop-signal paradigm was used to test response initiation, proactive inhibition, and reactive inhibition. The subjects enrolled in the experiment were 27 patients with PD, of whom 13 had received only drug treatment and 14 had received bilateral GPi-DBS in addition to conventional medical treatment and 15 healthy individuals. Results: Our results revealed that with GPi-DBS on, patients with PD showed significantly faster responses than the other groups in trials where it was certain that no stop signal would be presented. Proactive inhibition was significantly different in the surgical patients with GPi-DBS on versus when GPi-DBS was off, in surgical patients with GPi-DBS on versus drug-treated patients, and in healthy controls versus drug-treated patients. Correlation analyses revealed that when GPi-DBS was on, there was a statistically significant moderate positive relationship between proactive inhibition and dopaminergic medication. Conclusion: GPi-DBS may lead to an increase in response initiation speed and improve the dysfunctional proactive inhibitory control observed in PD patients. Our results may help us to understand the role of the GPi in cortical-basal ganglia circuits. PMID:29681869

  5. Inhibition of methane consumption in forest soils by monoterpenes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Amaral, J.A.; Knowles, R.

    1998-04-01

    Selected monoterpenes were tested for their ability to inhibit atmospheric methane consumption by three forest soils from different vegetation types and by the cultured methanotrophic strain, Methylosinus trichosporium OB3b. Subsurface soil from coniferous (Pinus banksiana), deciduous (Populus tremuloides), and mixed hardwood (Tsuga canadensis and Prunus pensylvanica) stands was used under field-moist and slurry conditions. Most of the hydrocarbon monoterpenes tested significantly inhibited methane consumption by soils at environmentally relevant levels, with ({minus})-{alpha}-pinene being the most effective. With the exception of {beta}-myrcene, monoterpenes also strongly inhibited methane oxidation by Methylosinus trichosporium OB3b. Carbon dioxide production was stimulated in all of themore » soils by the monoterpenes tested. In one case, methane production was stimulated by ({minus})-{alpha}-pinene in an intact, aerobic core. Oxide and alcohol monoterpenoids stimulated methane production. Thus, monoterpenes appear to be potentially important regulators of methane consumption and carbon metabolism in forest soils.« less

  6. Tolbutamide stimulates exocytosis of glucagon by inhibition of a mitochondrial-like ATP-sensitive K+ (KATP) conductance in rat pancreatic A-cells

    PubMed Central

    Høy, Marianne; Olsen, Hervør L; Bokvist, Krister; Buschard, Karsten; Barg, Sebastian; Rorsman, Patrik; Gromada, Jesper

    2000-01-01

    Capacitance measurements were used to examine the effects of the sulphonylurea tolbutamide on Ca2+-dependent exocytosis in isolated glucagon-secreting rat pancreatic A-cells. When applied extracellularly, tolbutamide stimulated depolarization-evoked exocytosis 4.2-fold without affecting the whole-cell Ca2+ current. The concentration dependence of the stimulatory action was determined by intracellular application through the recording pipette. Tolbutamide produced a concentration-dependent increase in cell capacitance. Half-maximal stimulation was observed at 33 μm and the maximum stimulation corresponded to a 3.4-fold enhancement of exocytosis. The stimulatory action of tolbutamide was dependent on protein kinase C activity. The action of tolbutamide was mimicked by the general K+ channel blockers TEA (10 mm) and quinine (10 μm). A similar stimulation was elicited by 5-hydroxydecanoate (5-HD; 10 μm), an inhibitor of mitochondrial ATP-sensitive K+ (KATP) channels. Tolbutamide-stimulated, but not TEA-induced, exocytosis was antagonized by the K+ channel openers diazoxide, pinacidil and cromakalim. Dissipating the transgranular K+ gradient with nigericin and valinomycin inhibited tolbutamide- and Ca2+-evoked exocytosis. Furthermore, tolbutamide- and Ca2+-induced exocytosis were abolished by the H+ ionophore FCCP or by arresting the vacuolar (V-type) H+-ATPase with bafilomycin A1 or DCCD. Finally, ammonium chloride stimulated exocytosis to a similar extent to that obtained with tolbutamide. We propose that during granular maturation, a granular V-type H+-ATPase pumps H+ into the secretory granule leading to the generation of a pH gradient across the granular membrane and the development of a positive voltage inside the granules. The pumping of H+ is facilitated by the concomitant exit of K+ through granular K+ channels with pharmacological properties similar to those of mitochondrial KATP channels. Release of granules that have been primed is then facilitated by the

  7. Gut-derived commensal bacterial products inhibit liver dendritic cell maturation by stimulating hepatic interleukin-6/signal transducer and activator of transcription 3 activity.

    PubMed

    Lunz, John G; Specht, Susan M; Murase, Noriko; Isse, Kumiko; Demetris, Anthony J

    2007-12-01

    Intraorgan dendritic cells (DCs) monitor the environment and help translate triggers of innate immunity into adaptive immune responses. Liver-based DCs are continually exposed, via gut-derived portal venous blood, to potential antigens and bacterial products that can trigger innate immunity. However, somehow the liver avoids a state of perpetual inflammation and protects central immune organs from overstimulation. In this study, we tested the hypothesis that hepatic interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) activity increases the activation/maturation threshold of hepatic DCs toward innate immune signals. The results show that the liver nuclear STAT3 activity is significantly higher than that of other organs and is IL-6-dependent. Hepatic DCs in normal IL-6 wild-type (IL-6(+/+)) mice are phenotypically and functionally less mature than DCs from IL-6-deficient (IL-6(-/-)) or STAT3-inhibited IL-6(+/+) mice, as determined by surface marker expression, proinflammatory cytokine secretion, and allogeneic T-cell stimulation. IL-6(+/+) liver DCs produce IL-6 in response to exposure to lipopolysaccharide (LPS) and cytidine phosphate guanosine oligonucleotides (CpG) but are resistant to maturation compared with IL-6(-/-) liver DCs. Conversely, exogenous IL-6 inhibits LPS-induced IL-6(-/-) liver DC maturation. IL-6/STAT3 signaling influences the liver DC expression of toll-like receptor 9 and IL-1 receptor associated kinase-M. The depletion of gut commensal bacteria in IL-6(+/+) mice with oral antibiotics decreased portal blood endotoxin levels, lowered the expression of IL-6 and phospho-STAT3, and significantly increased liver DC maturation. Gut-derived bacterial products, by stimulating hepatic IL-6/STAT3 signaling, inhibit hepatic DC activation/maturation and thereby elevate the threshold needed for translating triggers of innate immunity into adaptive immune responses. Manipulating gut bacteria may therefore be an effective strategy

  8. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling

    PubMed Central

    Pearcey, Gregory E. P.; Noble, Steven A.; Munro, Bridget; Zehr, E. Paul

    2017-01-01

    Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation (CONTROL + STIM), sprints with sensory stimulation (SPRINT + STIM) and sprints without stimulation (SPRINT). Seven participants also performed a fourth session (CONTROL), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM, participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM, participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared to

  9. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling.

    PubMed

    Pearcey, Gregory E P; Noble, Steven A; Munro, Bridget; Zehr, E Paul

    2017-01-01

    Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation ( CONTROL + STIM ), sprints with sensory stimulation ( SPRINT + STIM ) and sprints without stimulation ( SPRINT ). Seven participants also performed a fourth session ( CONTROL ), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM , participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM , participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared

  10. Corollary discharge inhibition of wind-sensitive cercal giant interneurons in the singing field cricket

    PubMed Central

    Hedwig, Berthold

    2014-01-01

    Crickets carry wind-sensitive mechanoreceptors on their cerci, which, in response to the airflow produced by approaching predators, triggers escape reactions via ascending giant interneurons (GIs). Males also activate their cercal system by air currents generated due to the wing movements underlying sound production. Singing males still respond to external wind stimulation, but are not startled by the self-generated airflow. To investigate how the nervous system discriminates sensory responses to self-generated and external airflow, we intracellularly recorded wind-sensitive afferents and ventral GIs of the cercal escape pathway in fictively singing crickets, a situation lacking any self-stimulation. GI spiking was reduced whenever cercal wind stimulation coincided with singing motor activity. The axonal terminals of cercal afferents showed no indication of presynaptic inhibition during singing. In two ventral GIs, however, a corollary discharge inhibition occurred strictly in phase with the singing motor pattern. Paired intracellular recordings revealed that this inhibition was not mediated by the activity of the previously identified corollary discharge interneuron (CDI) that rhythmically inhibits the auditory pathway during singing. Cercal wind stimulation, however, reduced the spike activity of this CDI by postsynaptic inhibition. Our study reveals how precisely timed corollary discharge inhibition of ventral GIs can prevent self-generated airflow from triggering inadvertent escape responses in singing crickets. The results indicate that the responsiveness of the auditory and wind-sensitive pathway is modulated by distinct CDIs in singing crickets and that the corollary discharge inhibition in the auditory pathway can be attenuated by cercal wind stimulation. PMID:25318763

  11. Stimulation of progesterone production by phorbol-12-myristate 13-acetate (PMA) in cultured Leydig tumor cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chaudhary, L.R.; Raju, V.S.; Stocco, D.M.

    1987-05-01

    It has been shown that addition of hCG or c-AMP to cultured Leydig tumor cells (MA-10) increases synthesis of progesterone as the major steroid. To investigate the possible involvement of protein kinase C (PK-C) in the regulation of steroid synthesis, the authors have studied the effect of PMA, an activator of PK-C, on progesterone production in MA-10 cells. The addition of PMA (100 ng/ml) stimulated steroid production whereas 4 -phorbol-12,13-didecanoate, an inactive phorbol ester, did not have any effects. Like hCG and c-AMP, PMA-stimulated progesterone production was inhibited by cycloheximide. hCG-stimulated steroid synthesis was inhibited by PMA. The addition ofmore » PMA to MA-10 Leydig cells further increased the c-AMP-stimulated progesterone production. To determine whether c-AMP has a obligatory role in the regulation of steroid production, the effect of adenylate cyclase inhibitor, 9-(tetrahydro-2-furyl)adenine (TFA), was studied on progesterone production in the presence of hCG. At lower dose (17 ng/ml) hCG-stimulated intracellular c-AMP levels and steroid production were inhibited by TFA (300 M). At higher dose of hCG (34 ng/ml) TFA did not inhibit the hCG-stimulated intracellular c-AMP levels, however, progesterone production was inhibited. Results suggest that the action of hCG, c-AMP and PMA in controlling steroidogenesis might be regulated by similar but different mechanisms.« less

  12. Mechanism of orientation of stimulating currents in magnetic brain stimulation (abstract)

    NASA Astrophysics Data System (ADS)

    Ueno, S.; Matsuda, T.

    1991-04-01

    We made a functional map of the human motor cortex related to the hand and foot areas by stimulating the human brain with a focused magnetic pulse. We observed that each functional area in the cortex has an optimum direction for which stimulating currents can produce neural excitation. The present report focuses on the mechanism which is responsible for producing this anisotropic response to brain stimulation. We first obtained a functional map of the brain related to the left ADM (abductor digiti minimi muscles). When the stimulating currents were aligned in the direction from the left to the right hemisphere, clear EMG (electromyographic) responses were obtained only from the left ADM to magnetic stimulation of both hemisphere. When the stimulating currents were aligned in the direction from the right to the left hemisphere, clear EMG signals were obtained only from the right ADM to magnetic stimulation of both hemisphere. The functional maps of the brain were sensitive to changes in the direction of the stimulating currents. To explain the phenomena obtained in the experiments, we developed a model of neural excitation elicited by magnetic stimulation. When eddy currents which are induced by pulsed magnetic fields flow in the direction from soma to the distal part of neural fiber, depolarized area in the distal part are excited, and the membrane excitation propagates along the nerve fiber. In contrast, when the induced currents flow in the direction from the distal part to soma, hyperpolarized parts block or inhibit neural excitation even if the depolarized parts near the soma can be excited. The model explains our observation that the orientation of the induced current vectors reflect both the functional and anatomical organization of the neural fibers in the brain.

  13. Carbachol inhibits basal and forskolin-evoked adult rat striatal acetylcholine release.

    PubMed

    Login, I S

    1997-05-27

    Acutely dissociated adult rat striatal cholinergic neurons labeled with [3H]choline were used in a perifusion system to study muscarinic regulation of basal and forskolin-stimulated fractional [3H]acetylcholine ([3H]-ACh) efflux in the absence of synaptic modulation. Carbachol inhibited basal (40% maximal inhibition; IC50 approximately 0.7 microM) and forskolin-evoked release (75% inhibition; IC50 approximately 0.05 microM) in a concentration-dependent manner, and both carbachol actions were abolished with atropine. Thus, activation of striatal muscarinic cholinergic autoreceptors potently inhibits basal and adenylate cyclase-stimulated ACh release. Tonic inhibitory control of cholinergic activity by functional striatal circuitry apparently prevents detection of these important physiological interactions in slices or in situ.

  14. Agnus castus extracts inhibit prolactin secretion of rat pituitary cells.

    PubMed

    Sliutz, G; Speiser, P; Schultz, A M; Spona, J; Zeillinger, R

    1993-05-01

    In our studies on prolactin inhibition by plant extracts we focused on the effects of extracts of Vitex agnus castus and its preparations on rat pituitary cells under basal and stimulated conditions in primary cell culture. Both extracts from Vitex agnus castus as well as synthetic dopamine agonists (Lisuride) significantly inhibit basal as well as TRH-stimulated prolactin secretion of rat pituitary cells in vitro and as a consequence inhibition of prolactin secretion could be blocked by adding a dopamine receptor blocker. Therefore because of its dopaminergic effect Agnus castus could be considered as an efficient alternative phytotherapeutic drug in the treatment of slight hyperprolactinaemia.

  15. Dexamethasone inhibits IL-12p40 production in lipopolysaccharide-stimulated human monocytic cells by down-regulating the activity of c-Jun N-terminal kinase, the activation protein-1, and NF-kappa B transcription factors.

    PubMed

    Ma, Wei; Gee, Katrina; Lim, Wilfred; Chambers, Kelly; Angel, Jonathan B; Kozlowski, Maya; Kumar, Ashok

    2004-01-01

    IL-12 plays a critical role in the development of cell-mediated immune responses and in the pathogenesis of inflammatory and autoimmune disorders. Dexamethasone (DXM), an anti-inflammatory glucocorticoid, has been shown to inhibit IL-12p40 production in LPS-stimulated monocytic cells. In this study, we investigated the molecular mechanism by which DXM inhibits IL-12p40 production by studying the role of the mitogen-activated protein kinases (MAPKs), and the key transcription factors involved in human IL-12p40 production in LPS-stimulated monocytic cells. A role for c-Jun N-terminal kinase (JNK) MAPK in LPS-induced IL-12p40 regulation in a promonocytic THP-1/CD14 cell line was demonstrated by using specific inhibitors of JNK activation, SP600125 and a dominant-negative stress-activated protein/extracellular signal-regulated kinase kinase-1 mutant. To identify transcription factors regulating IL-12p40 gene transcription, extensive deletion analyses of the IL-12p40 promoter was performed. The results revealed the involvement of a sequence encompassing the AP-1-binding site, in addition to that of NF-kappaB. The role of AP-1 in IL-12p40 transcription was confirmed by using antisense c-fos and c-jun oligonucleotides. Studies conducted to understand the regulation of AP-1 and NF-kappaB activation by JNK MAPK revealed that both DXM and SP600125 inhibited IL-12p40 gene transcription by inhibiting the activation of AP-1 and NF-kappaB transcription factors as revealed by luciferase reporter and gel mobility shift assays. Taken together, our results suggest that DXM may inhibit IL-12p40 production in LPS-stimulated human monocytic cells by down-regulating the activation of JNK MAPK, the AP-1, and NF-kappaB transcription factors.

  16. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Iwamura, Yoshihiro; Mori, Mayumi; Nakashima, Katsuhiko

    Highlights: Black-Right-Pointing-Pointer AIM induces lipolysis in a distinct manner from that of hormone-dependent lipolysis. Black-Right-Pointing-Pointer AIM ablates activity of peroxisome proliferator-activated receptor in adipocytes. Black-Right-Pointing-Pointer AIM reduces mRNA levels of lipid-droplet coating proteins leading to lipolysis. -- Abstract: Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance. However, the mechanism of how AIM mediates lipolysis remains unknown.more » Here we show that AIM induces lipolysis in a manner distinct from that of hormone-dependent lipolysis, without activation or augmentation of lipases. In vivo and in vitro, AIM did not enhance phosphorylation of hormone-sensitive lipase (HSL) in adipocytes, a hallmark of hormone-dependent lipolysis activation. Similarly, adipose tissue from obese AIM-deficient and wild-type mice showed comparable HSL phosphorylation. Consistent with the suppressive effect of AIM on fatty acid synthase activity, the amount of saturated and unsaturated fatty acids was reduced in adipocytes treated with AIM. This response ablated transcriptional activity of peroxisome proliferator-activated receptor (PPAR{gamma}), leading to diminished gene expression of lipid-droplet coating proteins including fat-specific protein 27 (FSP27) and Perilipin, which are indispensable for triacylglycerol storage in adipocytes. Accordingly, the lipolytic effect of AIM was overcome by a PPAR{gamma}-agonist or forced expression of FSP27, while it was synergized by a PPAR{gamma}-antagonist. Overall, distinct modes of lipolysis appear to take place in different

  17. Caffeine Inhibits Fluid Secretion by Interlobular Ducts From Guinea Pig Pancreas.

    PubMed

    Mochimaru, Yuka; Yamamoto, Akiko; Nakakuki, Miyuki; Yamaguchi, Makoto; Taniguchi, Ituka; Ishiguro, Hiroshi

    2017-04-01

    Caffeine is contained in coffee, tea, and numerous beverages and foods. We examined the direct effects of caffeine on the physiological function of pancreatic duct cells by using interlobular duct segments isolated from guinea pig pancreas. The rate of fluid secretion was continuously measured by monitoring the luminal volume of isolated duct segments. Changes in intracellular Ca concentration ([Ca]i) were estimated by microfluorometry in ducts loaded with Fura-2. Both secretin-stimulated and acetylcholine (ACh)-stimulated fluid secretions were substantially and reversibly inhibited by relatively low concentrations of caffeine as low as 0.03 mM relevant to blood levels after ingestion of caffeine-containing beverages. Caffeine inhibited ACh-induced elevation of [Ca]i and secretin-induced fluctuation of [Ca]i. Caffeine abolished thapsigargin-induced intracellular Ca release but did not affect the entry of extracellular Ca. Caffeine (0.05 mM) abolished ethanol (1 mM)-induced fluid hypersecretion in secretin-stimulated pancreatic duct. Low concentrations of caffeine directly inhibit pancreatic ductal fluid secretion stimulated by secretin or ACh and also ethanol-induced fluid hypersecretion. The inhibition by caffeine seems to be mediated by the blockade of intracellular Ca mobilization. Daily intake of caffeine may reduce the volume of pancreatic juice secretion.

  18. Stimulation of iodine organification in porcine thyroid cells by thyroid stimulators.

    PubMed

    Ginsberg, J; Shewring, G; Howells, R; Smith, B R; Hall, R

    Several Graves' sera were simultaneously assessed in a bioassay based on the ability of porcine thyroid cells to organify 125I and in a radioreceptor assay for TSH receptor binding activity. Both assay systems were sensitive to 1 mcU/ml (final concentration) of unlabelled bovine TSH. Six Graves' sera were studied in detail over a wide (0-1.0 mcl sera) dose response range in repeat determinations. Two sera exhibited parallel binding and stimulating. However, two sera revealed significant inhibition of 125I-TSH binding prior to the demonstration of stimulation and the other two sera showed stimulatory capabilities before significant binding was evident. IgG was prepared from one serum by ammonium sulphate precipitation and chromatography on Sepharose 6B and then subjected to preparative isoelectric focusing. The isoelectric distribution of the two activities were found to be identical with major peaks of activity at pl=9.5 and pl=8.5. In summary: 1) each Graves' sera exhibits different dose-response curves with respect to binding and stimulation, 2) at certain concentrations of sera, only binding or stimulation were evident, 3) neither assay was consistently more sensitive for the presence of Graves' immunoglobulins, 4) for one Graves' sera, binding and stimulation could not be separated by isoelectric focusing. These studies would suggest each Graves' immunoglobulin has inherently different characteristics in its interaction with the TSH receptor.

  19. Low-Frequency Repetitive Transcranial Magnetic Stimulation Targeted to Premotor Cortex Followed by Primary Motor Cortex Modulates Excitability Differently Than Premotor Cortex or Primary Motor Cortex Stimulation Alone.

    PubMed

    Chen, Mo; Deng, Huiqiong; Schmidt, Rebekah L; Kimberley, Teresa J

    2015-12-01

    The excitability of primary motor cortex (M1) can be modulated by applying low-frequency repetitive transcranial magnetic stimulation (rTMS) over M1 or premotor cortex (PMC). A comparison of inhibitory effect between the two locations has been reported with inconsistent results. This study compared the response secondary to rTMS applied over M1, PMC, and a combined PMC + M1 stimulation approach which first targets stimulation over PMC then M1. Ten healthy participants were recruited for a randomized, cross-over design with a one-week washout between visits. Each visit consisted of a pretest, an rTMS intervention, and a post-test. Outcome measures included short interval intracortical inhibition (SICI), intracortical facilitation (ICF), and cortical silent period (CSP). Participants received one of the three interventions in random order at each visit including: 1-Hz rTMS at 90% of resting motor threshold to: M1 (1200 pulses), PMC (1200 pulses), and PMC + M1 (600 pulses each, 1200 total). PMC + M1 stimulation resulted in significantly greater inhibition than the other locations for ICF (P = 0.005) and CSP (P < 0.001); for SICI, increased inhibition (group effect) was not observed after any of the three interventions, and there was no significant difference between the three interventions. The results indicate that PMC + M1 stimulation may modulate brain excitability differently from PMC or M1 alone. CSP was the assessment measure most sensitive to changes in inhibition and was able to distinguish between different inhibitory protocols. This work presents a novel procedure that may have positive implications for therapeutic interventions. © 2015 International Neuromodulation Society.

  20. The temporal pattern of stimulation may be important to the mechanism of deep brain stimulation

    PubMed Central

    Hess, Christopher W.; Vaillancourt, David E.; Okun, Michael S.

    2013-01-01

    Deep brain stimulation (DBS) has emerged as an important and potentially powerful treatment option for the management of carefully selected patients with advanced Parkinson's disease (PD) who are not adequately controlled by standard medication therapy. Though considerable advances have been made, the mechanisms underlying the therapeutic effects of DBS remain unclear despite its clinical efficacy. It is now widely held that both excitation and inhibition can occur secondary to stimulation, and it is suspected that abnormal synchronized oscillations may also be important in the mechanism of DBS. Other potentially important processes, including blood flow changes, local and upstream neurogenesis, and the modulation of neurotransmitters through stimulation of bordering astrocytes are also being investigated. Recent research has suggested that the temporal pattern of DBS stimulation is also an important variable in DBS neuromodulation, yet the extent of its influence on DBS efficacy has yet to be determined. As high stimulation frequency alone does not appear to be sufficient for optimal symptom suppression, attention to stimulation pattern might lead to more effective symptom control and reduced side effects, possibly at a lower frequency. Stimulation pattern may be potentially amenable to therapeutic modulation and its role in the clinical efficacy of DBS should be addressed through further focus and research. PMID:23399890

  1. Increased Inhibition in Non-Primary Motor Areas of String-Instrument Players: A Preliminary Study with Paired-Pulse Transcranial Magnetic Stimulation

    PubMed Central

    Vaalto, Selja; Julkunen, Petro; Säïsänen, Laura; Könönen, Mervi; Määttä, Sara; Karhu, Jari

    2016-01-01

    Background: The muscle representations in non-primary motor area (NPMA) are located in the dorsal premotor area (PMd) and in the border region between the premotor area and the supplementary motor area (SMA). Objective: We characterized the plasticity of intracortical inhibitory and excitatory circuits in muscle representations in primary motor cortex (M1) and in NPMA related to acquired fine motor skills. We compared local cortical inhibition and facilitation balance in M1 and in NPMA between control subjects (n = 6) and right-handed string-instrument players (n = 5). Methods: Navigated transcranial magnetic stimulation (TMS) was used to compare motor thresholds (MTs), motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) in non-dominant hand muscle representations in M1 and NPMA. Results: String-instrument players showed reduced SICI in M1 in the actively used left hand abductor digiti minimi (ADM) muscle representation at 3 ms inter-stimulus interval (ISI) with a conditioning stimulus (CS) intensity of 80% of MT and increased SICI in NPMA in ADM representation at 2 ms ISI and CS intensity of 50% of MT in comparison with controls. No differences between string-instrument players and controls were found for the SICI in the left hand opponens pollicis (OP) muscle representation, which is a muscle not intensively trained in string-instrument players. Conclusions: These preliminary results indicate that the stronger inhibition in motor representations outside M1 in string-instrument players may be crucial when accurate movements of single muscles must be performed. In contrast, weaker inhibition in M1 in string-instrument players may benefit the performance of fast finger movements. PMID:29765844

  2. Anodal Transcranial Direct Current Stimulation Reduces Psychophysically Measured Surround Suppression in the Human Visual Cortex

    PubMed Central

    Spiegel, Daniel P.; Hansen, Bruce C.; Byblow, Winston D.; Thompson, Benjamin

    2012-01-01

    Transcranial direct current stimulation (tDCS) is a safe, non-invasive technique for transiently modulating the balance of excitation and inhibition within the human brain. It has been reported that anodal tDCS can reduce both GABA mediated inhibition and GABA concentration within the human motor cortex. As GABA mediated inhibition is thought to be a key modulator of plasticity within the adult brain, these findings have broad implications for the future use of tDCS. It is important, therefore, to establish whether tDCS can exert similar effects within non-motor brain areas. The aim of this study was to assess whether anodal tDCS could reduce inhibitory interactions within the human visual cortex. Psychophysical measures of surround suppression were used as an index of inhibition within V1. Overlay suppression, which is thought to originate within the lateral geniculate nucleus (LGN), was also measured as a control. Anodal stimulation of the occipital poles significantly reduced psychophysical surround suppression, but had no effect on overlay suppression. This effect was specific to anodal stimulation as cathodal stimulation had no effect on either measure. These psychophysical results provide the first evidence for tDCS-induced reductions of intracortical inhibition within the human visual cortex. PMID:22563485

  3. Inhibition of tyrosinase activity and melanine pigmentation by 2-hydroxytyrosol

    PubMed Central

    Uchida, Ryuji; Ishikawa, Seiko; Tomoda, Hiroshi

    2014-01-01

    2-Hydroxytyrosol (2-HT), originally reported as a synthetic compound, was isolated for the first time as a fungal metabolite. 2-HT was found to inhibit mushroom tyrosinase with an IC50 value of 13.0 µmol/L. Furthermore, 2-HT dose-dependently inhibited tyrosinase activity (IC50, 32.5 µmol/L) in the cell-free extract of B16 melanoma cells and α-melanocyte stimulating hormone (α-MSH)-stimulated melanin formation in intact B16 melanoma cells. PMID:26579376

  4. Inhibition of tyrosinase activity and melanine pigmentation by 2-hydroxytyrosol.

    PubMed

    Uchida, Ryuji; Ishikawa, Seiko; Tomoda, Hiroshi

    2014-04-01

    2-Hydroxytyrosol (2-HT), originally reported as a synthetic compound, was isolated for the first time as a fungal metabolite. 2-HT was found to inhibit mushroom tyrosinase with an IC50 value of 13.0 µmol/L. Furthermore, 2-HT dose-dependently inhibited tyrosinase activity (IC50, 32.5 µmol/L) in the cell-free extract of B16 melanoma cells and α-melanocyte stimulating hormone (α-MSH)-stimulated melanin formation in intact B16 melanoma cells.

  5. Stimulation and inhibition of enzymatic hydrolysis by organosolv lignins as determined by zeta potential and hydrophobicity.

    PubMed

    Huang, Yang; Sun, Shaolong; Huang, Chen; Yong, Qiang; Elder, Thomas; Tu, Maobing

    2017-01-01

    Lignin typically inhibits enzymatic hydrolysis of cellulosic biomass, but certain organosolv lignins or lignosulfonates enhance enzymatic hydrolysis. The hydrophobic and electrostatic interactions between lignin and cellulases play critical roles in the enzymatic hydrolysis process. However, how to incorporate these two interactions into the consideration of lignin effects has not been investigated. We examined the physicochemical properties and the structures of ethanol organosolv lignins (EOL) from hardwood and softwood and ascertained the association between lignin properties and their inhibitory and stimulatory effects on enzymatic hydrolysis. The zeta potential and hydrophobicity of EOL lignin samples, isolated from organosolv pretreatment of cottonwood (CW), black willow (BW), aspen (AS), eucalyptus (EH), and loblolly pine (LP), were determined and correlated with their effects on enzymatic hydrolysis of Avicel. EOLs from CW, BW, and AS improved the 72 h hydrolysis yield by 8-12%, while EOLs from EH and LP decreased the 72 h hydrolysis yield by 6 and 16%, respectively. The results showed a strong correlation between the 72 h hydrolysis yield with hydrophobicity and zeta potential. The correlation indicated that the hydrophobicity of EOL had a negative effect and the negative zeta potential of EOL had a positive effect. HSQC NMR spectra showed that β- O -4 linkages in lignin react with ethanol to form an α -ethoxylated β- O -4' substructure (A') during organosolv pretreatment. Considerable amounts of C 2,6 -H 2,6 correlation in p -hydroxybenzoate (PB) units were observed for EOL-CW, EOL-BW, and EOL-AS, but not for EOL-EH and EOL-LP. This study revealed that the effect of lignin on enzymatic hydrolysis is a function of both hydrophobic interactions and electrostatic repulsions. The lignin inhibition is controlled by lignin hydrophobicity and the lignin stimulation is governed by the negative zeta potential. The net effect of lignin depends on the combined

  6. Magnolol inhibits LPS-induced inflammatory response in uterine epithelial cells : magnolol inhibits LPS-induced inflammatory response.

    PubMed

    Luo, Jia; Xu, Yanwen; Zhang, Minfang; Gao, Ling; Fang, Cong; Zhou, Canquan

    2013-10-01

    Endometritis is an inflammation of the uterine lining that is commonly initiated at parturition. The uterine epithelial cells play an important role in defending against invading pathogens. Magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, has been shown to have anti-inflammatory effects. The aim of this study was to investigate the anti-inflammatory effect of magnolol in modifying lipopolysaccharide (LPS)-induced signal pathways in mouse uterine epithelial cells. We found that magnolol inhibited TNF-α and IL-6 production in LPS-stimulated mouse uterine epithelial cells. We also found that magnolol inhibited LPS-induced NF-κB activation, IκBα degradation, phosphorylation of ERK, JNK, and P38. Furthermore, magnolol could significantly inhibit the expression of TLR4 stimulating by LPS. These results suggest that magnolol exerts an anti-inflammatory property by downregulating the expression of TLR4 upregulated by LPS, thereby attenuating TLR4-mediated NF-κB and MAPK signaling and the release of pro-inflammatory cytokines. These findings suggest that magnolol may be a therapeutic agent against endometritis.

  7. Houttuynia cordata Thunb. volatile oil exhibited anti-inflammatory effects in vivo and inhibited nitric oxide and tumor necrosis factor-α production in LPS-stimulated mouse peritoneal macrophages in vitro.

    PubMed

    Li, Weifeng; Fan, Ting; Zhang, Yanmin; Fan, Te; Zhou, Ping; Niu, Xiaofeng; He, Langchong

    2013-11-01

    Houttuynia cordata Thunb. (HC) is a medicinal herb that generally used in traditional Chinese medicine for treating allergic inflammation. The present study investigated the inhibitory effect of the volatile oil from HC Thunb. on animal models of inflammation and the production of inflammatory mediators in vivo and in vitro. In vivo, xylene-induced mouse ear edema, formaldehyde-induced paw edema and carrageenan-induced mice paw edema were significantly decreased by HC volatile oil. HC volatile oil showed pronounced inhibition of prostaglandin (PG) E2 and malondialdehyde production in the edematous exudates. In vitro exposure of mouse resident peritoneal macrophages to 1, 10, 100 and 1000 µg/mL of HC volatile oil significantly suppressed lipopolysaccharide (LPS)-stimulated production of NO and tumor necrosis factor-α (TNF-α) in a dose-dependent manner. Exposure to HC volatile oil had no effect on cell viability and systemic toxicity. Furthermore, HC volatile oil inhibited the production of NO and TNF-α by down-regulating LPS-stimulated iNOS and TNF-α mRNA expression. Western blot analysis showed that HC volatile oil attenuated LPS-stimulated synthesis of iNOS and TNF-α protein in the macrophages, in parallel. These findings add a novel aspect to the biological profile of HC and clarify its anti-inflammatory mechanism. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Thapsigargin defines the roles of cellular calcium in secretagogue-stimulated enzyme secretion from pancreatic acini.

    PubMed

    Metz, D C; Patto, R J; Mrozinski, J E; Jensen, R T; Turner, R J; Gardner, J D

    1992-10-15

    In the present study we used thapsigargin (TG), an inhibitor of microsomal calcium ATPase, to evaluate the roles of free cytoplasmic calcium and intracellular stored calcium in secretagogue-stimulated enzyme secretion from rat pancreatic acini. Using microspectrofluorimetry of fura-2-loaded pancreatic acini, we found that TG caused a sustained increase in free cytoplasmic calcium by mobilizing calcium from inositol 1,4,5-trisphosphate-sensitive intracellular stores and by increasing influx of extracellular calcium. TG also caused a small increase in basal amylase secretion, inhibited the stimulation of amylase secretion caused by secretagogues that increase inositol 1,4,5-trisphosphate, and potentiated the stimulation of amylase secretion caused by 12-O-tetradecanoylphorbol-13-acetate or secretagogues that increase cyclic adenosine 3',5'-monophosphate. Bombesin, which like TG increased free cytoplasmic calcium, also potentiated the stimulation of amylase secretion caused by secretagogues that increase cyclic adenosine 3',5'-monophosphate, but did not inhibit the stimulation of amylase secretion caused by secretagogues that increase inositol 1,4,5-trisphosphate. Finally, TG inhibited the sustained phase of cholecystokinin-stimulated amylase secretion and potentiated the time course of vasoactive intestinal peptide-stimulated amylase secretion. The present findings indicate that stimulation of amylase secretion by secretagogues that increase inositol 1,4,5-trisphosphate does not depend on increased free cytoplasmic calcium per se. In contrast, TG-induced potentiation of the stimulation of secretagogues that increase cellular cyclic adenosine 3',5'-monophosphate appears to result from increased free cytoplasmic calcium per se.

  9. Transcranial magnetic stimulation and potential cortical and trigeminothalamic mechanisms in migraine

    PubMed Central

    Andreou, Anna P.; Holland, Philip R.; Akerman, Simon; Summ, Oliver; Fredrick, Joe

    2016-01-01

    Abstract A single pulse of transcranial magnetic stimulation has been shown to be effective for the acute treatment of migraine with and without aura. Here we aimed to investigate the potential mechanisms of action of transcranial magnetic stimulation, using a transcortical approach, in preclinical migraine models. We tested the susceptibility of cortical spreading depression, the experimental correlate of migraine aura, and further evaluated the response of spontaneous and evoked trigeminovascular activity of second order trigemontothalamic and third order thalamocortical neurons in rats. Single pulse transcranial magnetic stimulation significantly inhibited both mechanical and chemically-induced cortical spreading depression when administered immediately post-induction in rats, but not when administered preinduction, and when controlled by a sham stimulation. Additionally transcranial magnetic stimulation significantly inhibited the spontaneous and evoked firing rate of third order thalamocortical projection neurons, but not second order neurons in the trigeminocervical complex, suggesting a potential modulatory effect that may underlie its utility in migraine. In gyrencephalic cat cortices, when administered post-cortical spreading depression, transcranial magnetic stimulation blocked the propagation of cortical spreading depression in two of eight animals. These results are the first to demonstrate that cortical spreading depression can be blocked in vivo using single pulse transcranial magnetic stimulation and further highlight a novel thalamocortical modulatory capacity that may explain the efficacy of magnetic stimulation in the treatment of migraine with and without aura. PMID:27246325

  10. Deep brain stimulation effects in dystonia: time course of electrophysiological changes in early treatment.

    PubMed

    Ruge, Diane; Tisch, Stephen; Hariz, Marwan I; Zrinzo, Ludvic; Bhatia, Kailash P; Quinn, Niall P; Jahanshahi, Marjan; Limousin, Patricia; Rothwell, John C

    2011-08-15

    Deep brain stimulation to the internal globus pallidus is an effective treatment for primary dystonia. The optimal clinical effect often occurs only weeks to months after starting stimulation. To better understand the underlying electrophysiological changes in this period, we assessed longitudinally 2 pathophysiological markers of dystonia in patients prior to and in the early treatment period (1, 3, 6 months) after deep brain stimulation surgery. Transcranial magnetic stimulation was used to track changes in short-latency intracortical inhibition, a measure of excitability of GABA(A) -ergic corticocortical connections and long-term potentiation-like synaptic plasticity (as a response to paired associative stimulation). Deep brain stimulation remained on for the duration of the study. Prior to surgery, inhibition was reduced and plasticity increased in patients compared with healthy controls. Following surgery and commencement of deep brain stimulation, short-latency intracortical inhibition increased toward normal levels over the following months with the same monotonic time course as the patients' clinical benefit. In contrast, synaptic plasticity changed rapidly, following a nonmonotonic time course: it was absent early (1 month) after surgery, and then over the following months increased toward levels observed in healthy individuals. We postulate that before surgery preexisting high levels of plasticity form strong memories of dystonic movement patterns. When deep brain stimulation is turned on, it disrupts abnormal basal ganglia signals, resulting in the absent response to paired associative stimulation at 1 month. Clinical benefit is delayed because engrams of abnormal movement persist and take time to normalize. Our observations suggest that plasticity may be a driver of long-term therapeutic effects of deep brain stimulation in dystonia. Copyright © 2011 Movement Disorder Society.

  11. Somatostatin, prostaglandin E2 and atropine inhibition of the gastric actions of bombesin in the dog.

    PubMed

    Hirschowitz, B I; Molina, E

    1984-01-01

    Bombesin, acetylcholine, prostaglandins and somatostatin are all thought to be involved in the regulation of gastrin release and gastric secretion. We have studied the effects of low doses of atropine, 16-16(Me)2-prostaglandin E2 (PGE2) and somatostatin-14 on bombesin-stimulated gastrin release and gastric acid and pepsin secretion in conscious fistula dogs. For reference, synthetic gastrin G-17 was studied with and without somatostatin. Bombesin, in a dose-related manner, increased serum gastrin, which in turn stimulated gastric acid and pepsin secretion in a serum gastrin, concentration-dependent manner. Somatostatin inhibited gastrin release by bombesin as well as the secretory stimulation by G-17; the combination of sequential effects resulted in a marked inhibition of bombesin-stimulated gastric acid and pepsin secretion. PGE2 also strongly inhibited gastrin release and acid and pepsin secretion. Atropine had no significant effect on gastrin release, but greatly inhibited gastric secretion. Thus somatostatin and PGE2 inhibited at two sites, gastrin release and gastrin effects, while atropine affected only the latter.

  12. Balanced feedforward inhibition and dominant recurrent inhibition in olfactory cortex

    PubMed Central

    Large, Adam M.; Vogler, Nathan W.; Mielo, Samantha; Oswald, Anne-Marie M.

    2016-01-01

    Throughout the brain, the recruitment of feedforward and recurrent inhibition shapes neural responses. However, disentangling the relative contributions of these often-overlapping cortical circuits is challenging. The piriform cortex provides an ideal system to address this issue because the interneurons responsible for feedforward and recurrent inhibition are anatomically segregated in layer (L) 1 and L2/3 respectively. Here we use a combination of optical and electrical activation of interneurons to profile the inhibitory input received by three classes of principal excitatory neuron in the anterior piriform cortex. In all classes, we find that L1 interneurons provide weaker inhibition than L2/3 interneurons. Nonetheless, feedforward inhibitory strength covaries with the amount of afferent excitation received by each class of principal neuron. In contrast, intracortical stimulation of L2/3 evokes strong inhibition that dominates recurrent excitation in all classes. Finally, we find that the relative contributions of feedforward and recurrent pathways differ between principal neuron classes. Specifically, L2 neurons receive more reliable afferent drive and less overall inhibition than L3 neurons. Alternatively, L3 neurons receive substantially more intracortical inhibition. These three features—balanced afferent drive, dominant recurrent inhibition, and differential recruitment by afferent vs. intracortical circuits, dependent on cell class—suggest mechanisms for olfactory processing that may extend to other sensory cortices. PMID:26858458

  13. Bisdemethoxycurcumin inhibits PDGF-induced vascular smooth muscle cell motility and proliferation

    PubMed Central

    Hua, Yinan; Dolence, Julia; Ramanan, Shalini; Ren, Jun; Nair, Sreejayan

    2013-01-01

    Scope A key event in the development of plaque in the arteries is the migration and proliferation of smooth muscle cells (SMCs) from the media to the intima of the blood vessel. This study was conducted to evaluate the effects of bisdemethoxycurcumin, a naturally occurring structural analog of curcumin, on PDGF-stimulated migration and proliferation of SMCs. Methods and results Demethoxycurcumin were synthesized by condensing vanillin and 4-hydroxybenzaldehyde. SMCs isolated from adult rat aorta were stimulated with PDGF in the presence or absence of curcumin or bisdemethoxycurcumin following which cell migration and proliferation were assessed by monolayer wound healing assay and [3H]-thymidine incorporation respectively. PDGF-induced phosphorylation of PDGF-receptor-β and its downstream effector Akt were assessed by Western blotting. Intracellular reactive oxygen species (ROS) was assessed using the fluorescent dye DCFDA. Bisdemethoxycurcumin elicited a concentration-dependent inhibition of PDGF-stimulated phosphorylation of PDGFR-β, Akt and Erk as well as the PDGF-stimulated SMC migration and proliferation. Bisdemethoxycurcumin was more potent than curcumin in inhibiting migration and proliferation and suppressing PDGF-signaling in SMCs. Both compounds were equipotent in inhibiting PDGF-stimulated intracellular ROS-generation. Conclusion Bisdemethoxycurcumin may be of potential use in the prevention or treatment of vascular disease. PMID:23554078

  14. Disparate effects of oxidation on plasma acyltransferase activities: inhibition of cholesterol esterification but stimulation of transesterification of oxidized phospholipids.

    PubMed

    Subbaiah, P V; Liu, M

    1996-05-31

    Oxidation of lipoproteins results in the formation of several polar phospholipids with pro-inflammatory and pro-atherogenic properties. To examine the possible role of lecithin/cholesterol acyltransferase (LCAT) in the metabolism of these oxidized phospholipids, we oxidized whole plasma with either Cu(2+) or a free-radical generator, and determined the various activities of LCAT. Oxidation caused a reduction in plasma phosphatidylcholine (PC), an increase in a short-chain polar PC (SCP-PC), and an inhibition of the transfer of long-chain acyl groups to cholesterol (LCAT activity) or to lyso PC (lysolecithin acyltransferase (LAT) I activity). However, the transfer of short-chain acyl groups from SCP-PC to lyso PCLAT II activity) was stimulated several fold, in direct correlation with the degree of oxidation. LAT II activity was not stimulated by oxidation in LCAT-deficient plasma, showing that it is carried out by LCAT. Oxidized normal plasma exhibited low LCAT activity even in the presence of exogenous proteoliposome substrate, indicating that the depletion of substrate PC was not responsible for the loss of activity. Oxidation of isolated LDL or HDL abolished their ability to support LCAT and LAT I activities of exogenous enzyme, but promoted the LAT II activity. Purified LCAT lost its LCAT and LAT I functions, but not its LAT II function, when oxidized in vitro. These results show that while oxidation of plasma causes a loss of LCAT's ability to transfer long-chain acyl groups, its ability to transfer short-chain acyl groups, from SCP-PC is retained, and even stimulated, suggesting that LCAT may have a physiological role in the metabolism of oxidized PC in plasma.

  15. Adiponectin inhibits insulin function in primary trophoblasts by PPARα-mediated ceramide synthesis.

    PubMed

    Aye, Irving L M H; Gao, Xiaoli; Weintraub, Susan T; Jansson, Thomas; Powell, Theresa L

    2014-04-01

    Maternal adiponectin (ADN) levels are inversely correlated with birth weight, and ADN infusion in pregnant mice down-regulates placental nutrient transporters and decreases fetal growth. In contrast to the insulin-sensitizing effects in adipose tissue and muscle, ADN inhibits insulin signaling in the placenta. However, the molecular mechanisms involved are unknown. We hypothesized that ADN inhibits insulin signaling and insulin-stimulated amino acid transport in primary human trophoblasts by peroxisome proliferator-activated receptor-α (PPARα)-mediated ceramide synthesis. Primary human term trophoblast cells were treated with ADN and/or insulin. ADN increased the phosphorylation of p38 MAPK and PPARα. ADN inhibited insulin signaling and insulin-stimulated amino acid transport. This effect was dependent on PPARα, because activation of PPARα with an agonist (GW7647) inhibited insulin signaling and function, whereas PPARα-small interfering RNA reversed the effects of ADN on the insulin response. ADN increased ceramide synthase expression and stimulated ceramide production. C2-ceramide inhibited insulin signaling and function, whereas inhibition of ceramide synthase (with Fumonisin B1) reversed the effects of ADN on insulin signaling and amino acid transport. These findings are consistent with the model that maternal ADN limits fetal growth mediated by activation of placental PPARα and ceramide synthesis, which inhibits placental insulin signaling and amino acid transport, resulting in reduced fetal nutrient availability.

  16. Adiponectin Inhibits Insulin Function in Primary Trophoblasts by PPARα-Mediated Ceramide Synthesis

    PubMed Central

    Gao, Xiaoli; Weintraub, Susan T.; Jansson, Thomas; Powell, Theresa L.

    2014-01-01

    Maternal adiponectin (ADN) levels are inversely correlated with birth weight, and ADN infusion in pregnant mice down-regulates placental nutrient transporters and decreases fetal growth. In contrast to the insulin-sensitizing effects in adipose tissue and muscle, ADN inhibits insulin signaling in the placenta. However, the molecular mechanisms involved are unknown. We hypothesized that ADN inhibits insulin signaling and insulin-stimulated amino acid transport in primary human trophoblasts by peroxisome proliferator-activated receptor-α (PPARα)-mediated ceramide synthesis. Primary human term trophoblast cells were treated with ADN and/or insulin. ADN increased the phosphorylation of p38 MAPK and PPARα. ADN inhibited insulin signaling and insulin-stimulated amino acid transport. This effect was dependent on PPARα, because activation of PPARα with an agonist (GW7647) inhibited insulin signaling and function, whereas PPARα-small interfering RNA reversed the effects of ADN on the insulin response. ADN increased ceramide synthase expression and stimulated ceramide production. C2-ceramide inhibited insulin signaling and function, whereas inhibition of ceramide synthase (with Fumonisin B1) reversed the effects of ADN on insulin signaling and amino acid transport. These findings are consistent with the model that maternal ADN limits fetal growth mediated by activation of placental PPARα and ceramide synthesis, which inhibits placental insulin signaling and amino acid transport, resulting in reduced fetal nutrient availability. PMID:24606127

  17. Cocaine inhibition of nicotinic acetylcholine receptors influences dopamine release

    PubMed Central

    Acevedo-Rodriguez, Alexandra; Zhang, Lifen; Zhou, Fuwen; Gong, Suzhen; Gu, Howard; De Biasi, Mariella; Zhou, Fu-Ming; Dani, John A.

    2014-01-01

    Nicotinic acetylcholine receptors (nAChRs) potently regulate dopamine (DA) release in the striatum and alter cocaine's ability to reinforce behaviors. Since cocaine is a weak nAChR inhibitor, we hypothesized that cocaine may alter DA release by inhibiting the nAChRs in DA terminals in the striatum and thus contribute to cocaine's reinforcing properties primarily associated with the inhibition of DA transporters. We found that biologically relevant concentrations of cocaine can mildly inhibit nAChR-mediated currents in midbrain DA neurons and consequently alter DA release in the dorsal and ventral striatum. At very high concentrations, cocaine also inhibits voltage-gated Na channels in DA neurons. Furthermore, our results show that partial inhibition of nAChRs by cocaine reduces evoked DA release. This diminution of DA release via nAChR inhibition more strongly influences release evoked at low or tonic stimulation frequencies than at higher (phasic) stimulation frequencies, particularly in the dorsolateral striatum. This cocaine-induced shift favoring phasic DA release may contribute to the enhanced saliency and motivational value of cocaine-associated memories and behaviors. PMID:25237305

  18. Effects of High-Definition and Conventional tDCS on Response Inhibition.

    PubMed

    Hogeveen, J; Grafman, J; Aboseria, M; David, A; Bikson, M; Hauner, K K

    2016-01-01

    Response inhibition is a critical executive function, enabling the adaptive control of behavior in a changing environment. The inferior frontal cortex (IFC) is considered to be critical for response inhibition, leading researchers to develop transcranial direct current stimulation (tDCS) montages attempting to target the IFC and improve inhibitory performance. However, conventional tDCS montages produce diffuse current through the brain, making it difficult to establish causality between stimulation of any one given brain region and resulting behavioral changes. Recently, high-definition tDCS (HD-tDCS) methods have been developed to target brain regions with increased focality relative to conventional tDCS. Remarkably few studies have utilized HD-tDCS to improve cognitive task performance, however, and no study has directly compared the behavioral effects of HD-tDCS to conventional tDCS. In the present study, participants received either HD-tDCS or conventional tDCS to the IFC during performance of a response inhibition task (stop-signal task, SST) or a control task (choice reaction time task, CRT). A third group of participants completed the same behavioral protocols, but received tDCS to a control site (mid-occipital cortex). Post-stimulation improvement in SST performance was analyzed as a function of tDCS group and the task performed during stimulation using both conventional and Bayesian parameter estimation analyses. Bayesian estimation of the effects of HD- and conventional tDCS to IFC relative to control site stimulation demonstrated enhanced response inhibition for both conditions. No improvements were found after control task (CRT) training in any tDCS condition. Results support the use of both HD- and conventional tDCS to the IFC for improving response inhibition, providing empirical evidence that HD-tDCS can be used to facilitate performance on an executive function task. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. 6-Gingerol inhibits ROS and iNOS through the suppression of PKC-{alpha} and NF-{kappa}B pathways in lipopolysaccharide-stimulated mouse macrophages

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Tzung-Yan, E-mail: joyamen@mail.cgu.edu.tw; Lee, Ko-Chen; Center for Traditional Chinese Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan

    2009-04-24

    Inflammation is involved in numerous diseases, including chronic inflammatory diseases and the development of cancer. Many plants possess a variety of biological activities, including antifungal, antibacterial and anti-inflammatory activities. However, our understanding of the anti-inflammatory effects of 6-gingerol is very limited. We used lipopolysaccharide (LPS)-stimulated macrophages as a model of inflammation to investigate the anti-inflammatory effects of 6-gingerol, which contains phenolic structure. We found that 6-gingerol exhibited an anti-inflammatory effect. 6-Gingerol could decrease inducible nitric oxide synthase and TNF-{alpha} expression through suppression of I-{kappa}B{alpha} phosphorylation, NF-{kappa}B nuclear activation and PKC-{alpha} translocation, which in turn inhibits Ca{sup 2+} mobilization and disruptionmore » of mitochondrial membrane potential in LPS-stimulated macrophages. Here, we demonstrate that 6-gingerol acts as an anti-inflammatory agent by blocking NF-{kappa}B and PKC signaling, and may be developed as a useful agent for the chemoprevention of cancer or inflammatory diseases.« less

  20. Multiple blocks of intermittent and continuous theta-burst stimulation applied via transcranial magnetic stimulation differently affect sensory responses in rat barrel cortex

    PubMed Central

    Thimm, Andreas; Funke, Klaus

    2015-01-01

    Cortical sensory processing varies with cortical state and the balance of inhibition to excitation. Repetitive transcranial magnetic stimulation (rTMS) has been shown to modulate human cortical excitability. In a rat model, we recently showed that intermittent theta-burst stimulation (iTBS) applied to the corpus callosum, to activate primarily supragranular cortical pyramidal cells but fewer subcortical neurons, strongly reduced the cortical expression of parvalbumin (PV), indicating reduced activity of fast-spiking interneurons. Here, we used the well-studied rodent barrel cortex system to test how iTBS and continuous TBS (cTBS) modulate sensory responses evoked by either single or double stimuli applied to the principal (PW) and/or adjacent whisker (AW) in urethane-anaesthetized rats. Compared to sham stimulation, iTBS but not cTBS particularly enhanced late (>18 ms) response components of multi-unit spiking and local field potential responses in layer 4 but not the very early response (<18 ms). Similarly, only iTBS diminished the suppression of the second response evoked by paired PW or AW–PW stimulation at 20 ms intervals. The effects increased with each of the five iTBS blocks applied. With cTBS a mild effect similar to that of iTBS was first evident after 4–5 stimulation blocks. Enhanced cortical c-Fos and zif268 expression but reduced PV and GAD67 expression was found only after iTBS, indicating increased cortical activity due to lowered inhibition. We conclude that iTBS but less cTBS may primarily weaken a late recurrent-type cortical inhibition mediated via a subset of PV+ interneurons, enabling stronger late response components believed to contribute to the perception of sensory events. PMID:25504571

  1. Focal hand dystonia: individualized intervention with repeated application of repetitive transcranial magnetic stimulation.

    PubMed

    Kimberley, Teresa Jacobson; Borich, Michael R; Schmidt, Rebekah L; Carey, James R; Gillick, Bernadette

    2015-04-01

    To examine for individual factors that may predict response to inhibitory repetitive transcranial magnetic stimulation (rTMS) in focal hand dystonia (FHD); to present the method for determining optimal stimulation to increase inhibition in a given patient; and to examine individual responses to prolonged intervention. Single-subject design to determine optimal parameters to increase inhibition for a given subject and to use the selected parameters once per week for 6 weeks, with 1-week follow-up, to determine response. Clinical research laboratory. A volunteer sample of subjects with FHD (N = 2). One participant had transcranial magnetic stimulation responses indicating impaired inhibition, and the other had responses within normative limits. There were 1200 pulses of 1-Hz rTMS delivered using 4 different stimulation sites/intensity combinations: primary motor cortex at 90% or 110% of resting motor threshold (RMT) and dorsal premotor cortex (PMd) at 90% or 110% of RMT. The parameters producing the greatest within-session increase in cortical silent period (CSP) duration were then used as the intervention. Response variables included handwriting pressure and velocity, subjective symptom rating, CSP, and short latency intracortical inhibition and facilitation. The individual with baseline transcranial magnetic stimulation responses indicating impaired inhibition responded favorably to the repeated intervention, with reduced handwriting force, an increase in the CSP, and subjective report of moderate symptom improvement at 1-week follow-up. The individual with normative baseline responses failed to respond to the intervention. In both subjects, 90% of RMT to the PMd produced the greatest lengthening of the CSP and was used as the intervention. An individualized understanding of neurophysiological measures can be an indicator of responsiveness to inhibitory rTMS in focal dystonia, with further work needed to determine likely responders versus nonresponders. Copyright

  2. Angiotensin II stimulates calcium-dependent activation of c-Jun N-terminal kinase.

    PubMed Central

    Zohn, I E; Yu, H; Li, X; Cox, A D; Earp, H S

    1995-01-01

    In GN4 rat liver epithelial cells, angiotensin II (Ang II) and other agonists which activate phospholipase C stimulate tyrosine kinase activity in a calcium-dependent, protein kinase C (PKC)-independent manner. Since Ang II also produces a proliferative response in these cells, we investigated downstream signaling elements traditionally linked to growth control by tyrosine kinases. First, Ang II, like epidermal growth factor (EGF), stimulated AP-1 binding activity in a PKC-independent manner. Because increases in AP-1 can reflect induction of c-Jun and c-Fos, we examined the activity of the mitogen-activated protein (MAP) kinase family members Erk-1 and -2 and the c-Jun N-terminal kinase (JNK), which are known to influence c-Jun and c-Fos transcription. Ang II stimulated MAP kinase (MAPK) activity but only approximately 50% as effectively as EGF; again, these effects were independent of PKC. Ang II also produced a 50- to 200-fold activation of JNK in a PKC-independent manner. Unlike its smaller effect on MAPK, Ang II was approximately four- to sixfold more potent in activating JNK than EGF was. Although others had reported a lack of calcium ionophore-stimulated JNK activity in lymphocytes and several other cell lines, we examined the role of calcium in GN4 cells. The following results suggest that JNK activation in rat liver epithelial cells is at least partially Ca(2+) dependent: (i) norepinephrine and vasopressin hormones that increase inositol 1,4,5-triphosphate stimulated JNK; (ii) both thapsigargin, a compound that produces an intracellular Ca(2+) signal, and Ca(2+) ionophores stimulated a dramatic increase in JNK activity (up to 200-fold); (iii) extracellular Ca(2+) chelation with ethylene glycol tetraacetic acid (EGTA) inhibited JNK activation by ionophore and intracellular chelation with 1,2-bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid tetraacetoxymethyl-ester (BAPTA-AM) partially inhibited JNK activation by Ang II or thapsigargin; and (iv) JNK

  3. Angiotensin-(1-7) has a dual role on growth-promoting signalling pathways in rat heart in vivo by stimulating STAT3 and STAT5a/b phosphorylation and inhibiting angiotensin II-stimulated ERK1/2 and Rho kinase activity.

    PubMed

    Giani, Jorge F; Gironacci, Mariela M; Muñoz, Marina C; Turyn, Daniel; Dominici, Fernando P

    2008-05-01

    Angiotensin (ANG) II contributes to cardiac remodelling by inducing the activation of several signalling molecules, including ERK1/2, Rho kinase and members of the STAT family of proteins. Angiotensin-(1-7) is produced in the heart and inhibits the proliferative actions of ANG II, although the mechanisms of this inhibition are poorly understood. Accordingly, in the present study we examined whether ANG-(1-7) affects the ANG II-mediated activation of ERK1/2 and Rho kinase, STAT3 and STAT5a/b in rat heart in vivo. We hypothesized that ANG-(1-7) inhibits these growth-promoting pathways, counterbalancing the trophic action of ANG II. Solutions of normal saline (0.9% NaCl) containing ANG II (8 pmol kg(-1)) plus ANG-(1-7) in increasing doses (from 0.08 to 800 pmol kg(-1)) were administered via the inferior vena cava to anaesthetized male Sprague-Dawley rats. After 5 min, hearts were removed and ERK1/2, Rho kinase, STAT3 and STAT5a/b phosphorylation was determined by Western blotting using phosphospecific antibodies. Angiotensin II stimulated ERK1/2 and Rho kinase phosphorylation (2.3 +/- 0.2- and 2.1 +/- 0.2-fold increase over basal values, respectively), while ANG-(1-7) was without effect. The ANG II-mediated phosphorylation of ERK1/2 and Rho kinase was prevented in a dose-dependent manner by ANG-(1-7) and disappeared in the presence of the Mas receptor antagonist d-Ala7-ANG-(1-7). Both ANG II and ANG-(1-7) increased STAT3 and STAT5a/b phosphorylation to a similar extent (130-140% increase). The ANG-(1-7)-stimulated STAT phosphorylation was blocked by the AT(1) receptor antagonist losartan and not by d-Ala7-ANG-(1-7). Our results show a dual action of ANG-(1-7), that is, a stimulatory effect on STAT3 and 5a/b phosphorylation through AT(1) receptors and a blocking action on ANG II-stimulated ERK1/2 and Rho kinase phosphorylation through Mas receptor activation. The latter effect could be representative of a mechanism for a protective role of ANG-(1-7) in the heart by

  4. Effect of inhibition of microsomal Ca(2+)-ATPase on cytoplasmic calcium and enzyme secretion in pancreatic acini.

    PubMed

    Metz, D C; Pradhan, T K; Mrozinski, J E; Jensen, R T; Turner, R J; Patto, R J; Gardner, J D

    1994-01-13

    We used thapsigargin (TG), 2,5-di-tert-butyl-1,4-benzohydroquinone (BHQ) and cyclopiazonic acid (CPA), each of which inhibits microsomal Ca(2+)-ATPase, to evaluate the effects of this inhibition on cytoplasmic free calcium ([Ca2+]i) and secretagogue-stimulated enzyme secretion in rat pancreatic acini. Using single-cell microspectrofluorimetry of fura-2-loaded acini we found that all three agents caused a sustained increase in [Ca2+]i by mobilizing calcium from inositol-(1,4,5)-trisphosphate-sensitive intracellular calcium stores and by promoting influx of extracellular calcium. Concentrations of all three agents that increased [Ca2+]i potentiated the stimulation of enzyme secretion caused by secretagogues that activate adenylate cyclase but inhibited the stimulation of enzyme secretion caused by secretagogues that activate phospholipase C. With BHQ, potentiation of adenylate cyclase-mediated enzyme secretion occurred immediately whereas inhibition of phospholipase C-mediated enzyme secretion occurred only after several min of incubation. In addition, the effects of BHQ and CPA on both [Ca2+]i and secretagogue-stimulated enzyme secretion were reversed completely by washing whereas the actions of TG could not be reversed by washing. Concentrations of BHQ in excess of those that caused maximal changes in [Ca2+]i inhibited all modes of stimulated enzyme secretion by a mechanism that was apparently unrelated to changes in [Ca2+]i. Finally, in contrast to the findings with TG and BHQ, CPA inhibited bombesin-stimulated enzyme secretion over a range of concentrations that was at least 10-fold lower than the range of concentrations over which CPA potentiated VIP-stimulated enzyme secretion.

  5. Glucocorticoids suppress calcium mobilization and phospholipid hydrolysis in anti-Ig antibody-stimulated B cells.

    PubMed

    Dennis, G; June, C H; Mizuguchi, J; Ohara, J; Witherspoon, K; Finkelman, F D; McMillan, V; Mond, J J

    1987-10-15

    Glucocorticoids have been shown to play a major role in influencing the activation of B lymphocytes. In view of our recent observation that dexamethasone exerts a marked suppressive effect on an early event in B cell activation that is stimulated by anti-Ig antibody, we investigated its activity on other stimuli that induce intracellular events similar to those produced by anti-Ig antibody. Because the intracellular events that occur after B cell stimulation with phorbol myristate acetate and the calcium ionophore A23187 appear to mimic those that occur after B cell stimulation with anti-Ig antibody, we studied whether the cellular responses elicited by these activation stimuli are affected in a similar fashion by dexamethasone. Whereas anti-Ig antibody-stimulated entry of G0 B cells to the G1 and S phase of the cell cycle was markedly suppressed by dexamethasone, phorbol myristate acetate/A23187 stimulation of these events was resistant to dexamethasone. Our finding that anti-Ig-induced cross-linking of B cell surface Ig, as measured by surface Ig capping, was not inhibited by dexamethasone suggested that corticosteroids inhibit anti-Ig-induced B cell proliferation at a step distal to membrane Ig cross-linking and proximal to phosphatidylinositol bisphosphate hydrolysis. This hypothesis is supported by experiments presented in this manuscript which demonstrate that dexamethasone inhibits anti-Ig-stimulated phosphatidylinositol bisphosphate hydrolysis. We also found that dexamethasone markedly inhibited anti-Ig antibody-stimulated increases in intracellular ionized calcium concentrations. This dexamethasone-mediated suppression is time-dependent as it is not seen when B cells are cultured with dexamethasone for less than 6 hr. Our data suggest that the immunomodulatory activity of glucocorticoids is exerted by binding to its nuclear receptor, thereby preventing the generation of second messengers required for cell activation after agonist-receptor interaction.

  6. A beta cell ATGL-lipolysis/adipose tissue axis controls energy homeostasis and body weight via insulin secretion in mice.

    PubMed

    Attané, Camille; Peyot, Marie-Line; Lussier, Roxane; Poursharifi, Pegah; Zhao, Shangang; Zhang, Dongwei; Morin, Johane; Pineda, Marco; Wang, Shupei; Dumortier, Olivier; Ruderman, Neil B; Mitchell, Grant A; Simons, Brigitte; Madiraju, S R Murthy; Joly, Erik; Prentki, Marc

    2016-12-01

    To directly assess the role of beta cell lipolysis in insulin secretion and whole-body energy homeostasis, inducible beta cell-specific adipose triglyceride lipase (ATGL)-deficient (B-Atgl-KO) mice were studied under normal diet (ND) and high-fat diet (HFD) conditions. Atgl flox/flox mice were cross-bred with Mip-Cre-ERT mice to generate Mip-Cre-ERT /+ ;Atgl flox/flox mice. At 8 weeks of age, these mice were injected with tamoxifen to induce deletion of beta cell-specific Atgl (also known as Pnpla2), and the mice were fed an ND or HFD. ND-fed male B-Atgl-KO mice showed decreased insulinaemia and glucose-induced insulin secretion (GSIS) in vivo. Changes in GSIS correlated with the islet content of long-chain saturated monoacylglycerol (MAG) species that have been proposed to be metabolic coupling factors for insulin secretion. Exogenous MAGs restored GSIS in B-Atgl-KO islets. B-Atgl-KO male mice fed an HFD showed reduced insulinaemia, glycaemia in the fasted and fed states and after glucose challenge, as well as enhanced insulin sensitivity. Moreover, decreased insulinaemia in B-Atgl-KO mice was associated with increased energy expenditure, and lipid metabolism in brown (BAT) and white (WAT) adipose tissues, leading to reduced fat mass and body weight. ATGL in beta cells regulates insulin secretion via the production of signalling MAGs. Decreased insulinaemia due to lowered GSIS protects B-Atgl-KO mice from diet-induced obesity, improves insulin sensitivity, increases lipid mobilisation from WAT and causes BAT activation. The results support the concept that fuel excess can drive obesity and diabetes via hyperinsulinaemia, and that an islet beta cell ATGL-lipolysis/adipose tissue axis controls energy homeostasis and body weight via insulin secretion.

  7. Intestinal mucus protects Giardia lamblia from killing by human milk.

    PubMed

    Zenian, A J; Gillin, F D

    1987-02-01

    We have previously shown that nonimmune human milk kills Giardia lamblia trophozoites in vitro. Killing requires a bile salt and the activity of the milk bile salt-stimulated lipase. We now show that human small-intestinal mucus protects trophozoites from killing by milk. Parasite survival increased with mucus concentration, but protection was overcome during longer incubation times or with greater milk concentrations. Trophozoites preincubated with mucus and then washed were not protected. Protective activity was associated with non-mucin CsCl density gradient fractions. Moreover, it was heat-stable, non-dialyzable, and non-lipid. Whereas whole mucus inhibited milk lipolytic activity, protective mucus fractions did not inhibit the enzyme. Furthermore, mucus partially protected G. lamblia trophozoites against the toxicity of oleic acid, a fatty acid which is released from milk triglycerides by lipase. These studies show that mucus protects G. lamblia both by inhibiting lipase activity and by decreasing the toxicity of products of lipolysis. The ability of mucus to protect G. lamblia from toxic lipolytic products may help to promote intestinal colonization by this parasite.

  8. Slow oscillating transcranial direct current stimulation during non-rapid eye movement sleep improves behavioral inhibition in attention-deficit/hyperactivity disorder

    PubMed Central

    Munz, Manuel T.; Prehn-Kristensen, Alexander; Thielking, Frederieke; Mölle, Matthias; Göder, Robert; Baving, Lioba

    2015-01-01

    Background: Behavioral inhibition, which is a later-developing executive function (EF) and anatomically located in prefrontal areas, is impaired in attention-deficit and hyperactivity disorder (ADHD). While optimal EFs have been shown to depend on efficient sleep in healthy subjects, the impact of sleep problems, frequently reported in ADHD, remains elusive. Findings of macroscopic sleep changes in ADHD are inconsistent, but there is emerging evidence for distinct microscopic changes with a focus on prefrontal cortical regions and non-rapid eye movement (non-REM) slow-wave sleep. Recently, slow oscillations (SO) during non-REM sleep were found to be less functional and, as such, may be involved in sleep-dependent memory impairments in ADHD. Objective:By augmenting slow-wave power through bilateral, slow oscillating transcranial direct current stimulation (so-tDCS, frequency = 0.75 Hz) during non-REM sleep, we aimed to improve daytime behavioral inhibition in children with ADHD. Methods: Fourteen boys (10–14 years) diagnosed with ADHD were included. In a randomized, double-blind, cross-over design, patients received so-tDCS either in the first or in the second experimental sleep night. Inhibition control was assessed with a visuomotor go/no-go task. Intrinsic alertness was assessed with a simple stimulus response task. To control for visuomotor performance, motor memory was assessed with a finger sequence tapping task. Results: SO-power was enhanced during early non-REM sleep, accompanied by slowed reaction times and decreased standard deviations of reaction times, in the go/no-go task after so-tDCS. In contrast, intrinsic alertness, and motor memory performance were not improved by so-tDCS. Conclusion: Since behavioral inhibition but not intrinsic alertness or motor memory was improved by so-tDCS, our results suggest that lateral prefrontal slow oscillations during sleep might play a specific role for executive functioning in ADHD. PMID:26321911

  9. Slow oscillating transcranial direct current stimulation during non-rapid eye movement sleep improves behavioral inhibition in attention-deficit/hyperactivity disorder.

    PubMed

    Munz, Manuel T; Prehn-Kristensen, Alexander; Thielking, Frederieke; Mölle, Matthias; Göder, Robert; Baving, Lioba

    2015-01-01

    Behavioral inhibition, which is a later-developing executive function (EF) and anatomically located in prefrontal areas, is impaired in attention-deficit and hyperactivity disorder (ADHD). While optimal EFs have been shown to depend on efficient sleep in healthy subjects, the impact of sleep problems, frequently reported in ADHD, remains elusive. Findings of macroscopic sleep changes in ADHD are inconsistent, but there is emerging evidence for distinct microscopic changes with a focus on prefrontal cortical regions and non-rapid eye movement (non-REM) slow-wave sleep. Recently, slow oscillations (SO) during non-REM sleep were found to be less functional and, as such, may be involved in sleep-dependent memory impairments in ADHD. By augmenting slow-wave power through bilateral, slow oscillating transcranial direct current stimulation (so-tDCS, frequency = 0.75 Hz) during non-REM sleep, we aimed to improve daytime behavioral inhibition in children with ADHD. Fourteen boys (10-14 years) diagnosed with ADHD were included. In a randomized, double-blind, cross-over design, patients received so-tDCS either in the first or in the second experimental sleep night. Inhibition control was assessed with a visuomotor go/no-go task. Intrinsic alertness was assessed with a simple stimulus response task. To control for visuomotor performance, motor memory was assessed with a finger sequence tapping task. SO-power was enhanced during early non-REM sleep, accompanied by slowed reaction times and decreased standard deviations of reaction times, in the go/no-go task after so-tDCS. In contrast, intrinsic alertness, and motor memory performance were not improved by so-tDCS. Since behavioral inhibition but not intrinsic alertness or motor memory was improved by so-tDCS, our results suggest that lateral prefrontal slow oscillations during sleep might play a specific role for executive functioning in ADHD.

  10. Muscimol increases acetylcholine release by directly stimulating adult striatal cholinergic interneurons.

    PubMed

    Login, I S; Pal, S N; Adams, D T; Gold, P E

    1998-01-01

    Because GabaA ligands increase acetylcholine (ACh) release from adult striatal slices, we hypothesized that activation of GabaA receptors on striatal cholinergic interneurons directly stimulates ACh secretion. Fractional [3H]ACh release was recorded during perifusion of acutely dissociated, [3H]choline-labeled, adult male rat striata. The GabaA agonist, muscimol, immediately stimulated release maximally approximately 300% with EC50 = approximately 1 microM. This action was enhanced by the allosteric GabaA receptor modulators, diazepam and secobarbital, and inhibited by the GabaA antagonist, bicuculline, by ligands for D2 or muscarinic cholinergic receptors or by low calcium buffer, tetrodotoxin or vesamicol. Membrane depolarization inversely regulated muscimol-stimulated secretion. Release of endogenous and newly synthesized ACh was stimulated in parallel by muscimol without changing choline release. Muscimol pretreatment inhibited release evoked by K+ depolarization or by receptor-mediated stimulation with glutamate. Thus, GabaA receptors on adult striatal cholinergic interneurons directly stimulate voltage- and calcium-dependent exocytosis of ACh stored in vesamicol-sensitive synaptic vesicles. The action depends on the state of membrane polarization and apparently depolarizes the membrane in turn. This functional assay demonstrates that excitatory GabaA actions are not limited to neonatal tissues. GabaA-stimulated ACh release may be prevented in situ by normal tonic dopaminergic and muscarinic input to cholinergic neurons.

  11. Silymarin inhibits ultraviolet radiation-induced immune suppression through DNA repair-dependent activation of dendritic cells and stimulation of effector T cells

    PubMed Central

    Vaid, Mudit; Prasad, Ram; Singh, Tripti; Elmets, Craig A.; Xu, Hui; Katiyar, Santosh K.

    2013-01-01

    Silymarin inhibits UVB-induced immunosuppression in mouse skin. To identify the molecular mechanisms underlying this effect, we used an adoptive transfer approach in which dendritic cells (DCs) from the draining lymph nodes of donor mice that had been UVB-exposed and sensitized to 2,4,-dinitrofluorobenzene (DNFB) were transferred into naïve recipient mice. The contact hypersensitivity (CHS) response of the recipient mice to DNFB was then measured. When DCs were obtained from UVB-exposed donor mice that were not treated with silymarin, the CHS response was suppressed confirming the role of DCs in the UVB-induced immunosuppression. Silymarin treatment of UVB-exposed donor mice relieved this suppression of the CHS response in the recipients. Silymarin treatment was associated with rapid repair of UVB-induced cyclobutane pyrimidine dimers (CPDs) in DCs and silymarin treatment did not prevent UV-induced immunosuppression in XPA-deficient mice which are unable to repair UV-induced DNA damage. The CHS response in mice receiving DCs from silymarin-treated UV-exposed donor mice also was associated with enhanced secretion of Th1-type cytokines and stimulation of T cells. Adoptive transfer of T cells revealed that transfer of either CD8+ or CD4+ cells from silymarin-treated, UVB-exposed donors resulted in enhancement of the CHS response. Cell culture study showed enhanced secretion of IL-2 and IFNγ by CD8+ T cells, and reduced secretion of Th2 cytokines by CD4+ cells, obtained from silymarin-treated UVB-exposed mice. These data suggest that DNA repair-dependent functional activation of DCs, a reduction in CD4+ regulatory T-cell activity, and stimulation of CD8+ effector T cells contribute to silymarin-mediated inhibition of UVB-induced immunosuppression. PMID:23395695

  12. Transcranial magnetic stimulation and potential cortical and trigeminothalamic mechanisms in migraine.

    PubMed

    Andreou, Anna P; Holland, Philip R; Akerman, Simon; Summ, Oliver; Fredrick, Joe; Goadsby, Peter J

    2016-07-01

    A single pulse of transcranial magnetic stimulation has been shown to be effective for the acute treatment of migraine with and without aura. Here we aimed to investigate the potential mechanisms of action of transcranial magnetic stimulation, using a transcortical approach, in preclinical migraine models. We tested the susceptibility of cortical spreading depression, the experimental correlate of migraine aura, and further evaluated the response of spontaneous and evoked trigeminovascular activity of second order trigemontothalamic and third order thalamocortical neurons in rats. Single pulse transcranial magnetic stimulation significantly inhibited both mechanical and chemically-induced cortical spreading depression when administered immediately post-induction in rats, but not when administered preinduction, and when controlled by a sham stimulation. Additionally transcranial magnetic stimulation significantly inhibited the spontaneous and evoked firing rate of third order thalamocortical projection neurons, but not second order neurons in the trigeminocervical complex, suggesting a potential modulatory effect that may underlie its utility in migraine. In gyrencephalic cat cortices, when administered post-cortical spreading depression, transcranial magnetic stimulation blocked the propagation of cortical spreading depression in two of eight animals. These results are the first to demonstrate that cortical spreading depression can be blocked in vivo using single pulse transcranial magnetic stimulation and further highlight a novel thalamocortical modulatory capacity that may explain the efficacy of magnetic stimulation in the treatment of migraine with and without aura. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

  13. Brief Report: Blockade of TANK-Binding Kinase 1/IKKɛ Inhibits Mutant Stimulator of Interferon Genes (STING)-Mediated Inflammatory Responses in Human Peripheral Blood Mononuclear Cells.

    PubMed

    Frémond, Marie-Louise; Uggenti, Carolina; Van Eyck, Lien; Melki, Isabelle; Bondet, Vincent; Kitabayashi, Naoki; Hertel, Christina; Hayday, Adrian; Neven, Bénédicte; Rose, Yoann; Duffy, Darragh; Crow, Yanick J; Rodero, Mathieu P

    2017-07-01

    Gain-of-function mutations in TMEM173, encoding the stimulator of interferon (IFN) genes (STING) protein, underlie a novel type I interferonopathy that is minimally responsive to conventional immunosuppressive therapies and associated with high frequency of childhood morbidity and mortality. STING gain-of-function causes constitutive oversecretion of IFN. This study was undertaken to determine the effects of a TANK-binding kinase 1 (TBK-1)/IKKɛ inhibitor (BX795) on secretion and signaling of IFN in primary peripheral blood mononuclear cells (PBMCs) from patients with mutations in STING. PBMCs from 4 patients with STING-associated disease were treated with BX795. The effect of BX795 on IFN pathways was assessed by Western blotting and an IFNβ reporter assay, as well as by quantification of IFNα in cell lysates, staining for STAT-1 phosphorylation, and measurement of IFN-stimulated gene (ISG) messenger RNA (mRNA) expression. Treatment of PBMCs with BX795 inhibited the phosphorylation of IFN regulatory factor 3 and IFNβ promoter activity induced in HEK 293T cells by cyclic GMP-AMP or by genetic activation of STING. In vitro exposure to BX795 inhibited IFNα production in PBMCs of patients with STING-associated disease without affecting cell survival. In addition, BX795 decreased STAT-1 phosphorylation and ISG mRNA expression independent of IFNα blockade. These findings demonstrate the effect of BX795 on reducing type I IFN production and IFN signaling in cells from patients with gain-of-function mutations in STING. A combined inhibition of TBK-1 and IKKɛ therefore holds potential for the treatment of patients carrying STING mutations, and may also be relevant in other type I interferonopathies. © 2017, American College of Rheumatology.

  14. Mangiferin ameliorates colitis by inhibiting IRAK1 phosphorylation in NF-κB and MAPK pathways.

    PubMed

    Jeong, Jin-Ju; Jang, Se-Eun; Hyam, Supriya R; Han, Myung Joo; Kim, Dong-Hyun

    2014-10-05

    Mangiferin, a main constituent of the root of Anemarrhena asphodeloides and the leaves of Mangifera indica, inhibits NF-κB activation in macrophages. Therefore, we investigated effect of mangiferin on 2,3,4-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice and its anti-inflammatory mechanism in lipolysaccharide (LPS)- or peptidoglycan-stimulated mouse peritoneal macrophages. Mangiferin inhibited phosphorylation of nuclear factor-kappaB (NF-κB), interleukin-1 receptor-associated kinase 1 (IRAK1), and mitogen-activated protein kinases (MAPK) in peptidoglycan- or LPS-stimulated peritoneal macrophages. Mangiferin in the presence of SN50 inhibited LPS-stimulated NF-κB activation more potently than mangiferin alone. Mangiferin inhibited interaction of fluorescent p-IRAK1 antibody to LPS-stimulated peritoneal macrophages, but increased binding of fluorescent IRAK1 antibody. Mangiferin did not influence interaction of fluorescent LPS to toll-like receptor-4 on the macrophages. Molecular peak of mangiferin bound to IRAK1 was detected in the macrophages by mass analysis. Mangiferin (10 μM) inhibited LPS-stimulated expression of TNF-α, IL-1β and IL-6 by 81.0%, 89.5% and 88.3%, respectively, whereas it increased IL-10 expression by 131.8% compared to LPS-nontreated group. Mangiferin furthermore inhibited colon shortening, macroscopic score, and colonic myeloperoxidase activity in TNBS-induced colitic mice. Mangiferin inhibited TNBS-induced IRAK1 phosphorylation and NF-κB activation. Mangiferin suppressed TNBS-induced up-regulation of cyclooxygenase-2 and inducible NO synthase. Furthermore, mangiferin (20mg/kg) significantly inhibited TNF-α by 78%, IL-1β by 82%, and IL-6 expressions by 88% (P<0.05), but induced IL-10 expression to 79% of the normal control group (P<0.05). Based on these findings, mangiferin may ameliorate inflammatory diseases such as colitis by regulating NF-κB and MAPK signaling pathways through the inhibition of IRAK1 phosphorylation

  15. A new mechanism of interferon's antiviral action: Induction of autophagy, essential for paramyxovirus replication, is inhibited by the interferon stimulated gene, TDRD7.

    PubMed

    Subramanian, Gayatri; Kuzmanovic, Teodora; Zhang, Ying; Peter, Cara Beate; Veleeparambil, Manoj; Chakravarti, Ritu; Sen, Ganes C; Chattopadhyay, Saurabh

    2018-01-01

    The interferon (IFN) system represents the first line of defense against a wide range of viruses. Virus infection rapidly triggers the transcriptional induction of IFN-β and IFN Stimulated Genes (ISGs), whose protein products act as viral restriction factors by interfering with specific stages of virus life cycle, such as entry, transcription, translation, genome replication, assembly and egress. Here, we report a new mode of action of an ISG, IFN-induced TDRD7 (tudor domain containing 7) inhibited paramyxovirus replication by inhibiting autophagy. TDRD7 was identified as an antiviral gene by a high throughput screen of an ISG shRNA library for blocking IFN's protective effect against Sendai virus (SeV) replication. The antiviral activity of TDRD7 against SeV, human parainfluenza virus 3 and respiratory syncytial virus was confirmed by its genetic ablation or ectopic expression in several types of mouse and human cells. TDRD7's antiviral action was mediated by its ability to inhibit autophagy, a cellular catabolic process which was robustly induced by SeV infection and required for its replication. Mechanistic investigation revealed that TDRD7 interfered with the activation of AMP-dependent kinase (AMPK), an enzyme required for initiating autophagy. AMPK activity was required for efficient replication of several paramyxoviruses, as demonstrated by its genetic ablation or inhibition of its activity by TDRD7 or chemical inhibitors. Therefore, our study has identified a new antiviral ISG with a new mode of action.

  16. Partially non-linear stimulation intensity-dependent effects of direct current stimulation on motor cortex excitability in humans.

    PubMed

    Batsikadze, G; Moliadze, V; Paulus, W; Kuo, M-F; Nitsche, M A

    2013-04-01

    Transcranial direct current stimulation (tDCS) of the human motor cortex at an intensity of 1 mA with an electrode size of 35 cm(2) has been shown to induce shifts of cortical excitability during and after stimulation. These shifts are polarity-specific with cathodal tDCS resulting in a decrease and anodal stimulation in an increase of cortical excitability. In clinical and cognitive studies, stronger stimulation intensities are used frequently, but their physiological effects on cortical excitability have not yet been explored. Therefore, here we aimed to explore the effects of 2 mA tDCS on cortical excitability. We applied 2 mA anodal or cathodal tDCS for 20 min on the left primary motor cortex of 14 healthy subjects. Cathodal tDCS at 1 mA and sham tDCS for 20 min was administered as control session in nine and eight healthy subjects, respectively. Motor cortical excitability was monitored by transcranial magnetic stimulation (TMS)-elicited motor-evoked potentials (MEPs) from the right first dorsal interosseous muscle. Global corticospinal excitability was explored via single TMS pulse-elicited MEP amplitudes, and motor thresholds. Intracortical effects of stimulation were obtained by cortical silent period (CSP), short latency intracortical inhibition (SICI) and facilitation (ICF), and I wave facilitation. The above-mentioned protocols were recorded both before and immediately after tDCS in randomized order. Additionally, single-pulse MEPs, motor thresholds, SICI and ICF were recorded every 30 min up to 2 h after stimulation end, evening of the same day, next morning, next noon and next evening. Anodal as well as cathodal tDCS at 2 mA resulted in a significant increase of MEP amplitudes, whereas 1 mA cathodal tDCS decreased corticospinal excitability. A significant shift of SICI and ICF towards excitability enhancement after both 2 mA cathodal and anodal tDCS was observed. At 1 mA, cathodal tDCS reduced single-pulse TMS-elicited MEP amplitudes and shifted SICI

  17. Brain Stimulation and the Role of the Right Hemisphere in Aphasia Recovery.

    PubMed

    Turkeltaub, Peter E

    2015-11-01

    Aphasia is a common consequence of left hemisphere stroke and causes a disabling loss of language and communication ability. Current treatments for aphasia are inadequate, leaving a majority of aphasia sufferers with ongoing communication difficulties for the rest of their lives. In the past decade, two forms of noninvasive brain stimulation, repetitive transcranial magnetic stimulation and transcranial direct current stimulation, have emerged as promising new treatments for aphasia. The most common brain stimulation protocols attempt to inhibit the intact right hemisphere based on the hypothesis that maladaptive activity in the right hemisphere limits language recovery in the left. There is now sufficient evidence to demonstrate that this approach, at least for repetitive transcranial magnetic stimulation, improves specific language abilities in aphasia. However, the biological mechanisms that produce these behavioral improvements remain poorly understood. Taken in the context of the larger neurobiological literature on aphasia recovery, the role of the right hemisphere in aphasia recovery remains unclear. Additional research is needed to understand biological mechanisms of recovery, in order to optimize brain stimulation treatments for aphasia. This article summarizes the current evidence on noninvasive brain stimulation methods for aphasia and the neuroscientific considerations surrounding treatments using right hemisphere inhibition. Suggestions are provided for further investigation and for clinicians whose patients ask about brain stimulation treatments for aphasia.

  18. Inhibition and stimulation effects in communities of wood decay fungi: exudates from colonized wood influence growth by other species.

    PubMed

    Heilmann-Clausen, J; Boddy, L

    2005-04-01

    The effects of exudates from uncolonized and from partly decayed beech wood on the extension rates of 16 later stage decay fungi were investigated. The partly decayed wood had been colonized by the pyrenomycete Eutypa spinosa, or the basidiomycetes Fomes fomentarius, Stereum hirsutum, and Trametes versicolor, all known as common early decay agents in European beech forests. Sterilized wood pieces were placed onto 0.5% malt agar, opposite to small agar plugs containing the test fungi. The latter showed very variable and species-specific growth responses to the various wood types. The presence of uncolonized wood stimulated extension rates in many species, whereas the four previously decayed wood types had variable stimulatory or inhibitory effects. Wood decayed by S. hirsutum resulted in reduced extension rate, delayed growth, or total inhibition in the majority of species, thus it is suggested that this species uses secondary metabolites in a defensive strategy. A single species was, however, stimulated in the presence of S. hirsutum-decayed wood. In contrast, the presence of wood decayed by F. fomentarius was stimulatory to 45% of the species. The other previously decayed wood types generally resulted in more variable responses, depending upon species. The results are discussed in an ecological context and it is suggested that the exudates from the partly decayed wood that are responsible for the reported effects may function as infochemicals, structuring microbial communities in wood.

  19. Prostaglandin E1 inhibits endocytosis in the β-cell endocytosis.

    PubMed

    Zhao, Ying; Fang, Qinghua; Straub, Susanne G; Lindau, Manfred; Sharp, Geoffrey W G

    2016-06-01

    Prostaglandins inhibit insulin secretion in a manner similar to that of norepinephrine (NE) and somatostatin. As NE inhibits endocytosis as well as exocytosis, we have now examined the modulation of endocytosis by prostaglandin E1 (PGE1). Endocytosis following exocytosis was recorded by whole-cell patch clamp capacitance measurements in INS-832/13 cells. Prolonged depolarizing pulses producing a high level of Ca(2+) influx were used to stimulate maximal exocytosis and to deplete the readily releasable pool (RRP) of granules. This high Ca(2+) influx eliminates the inhibitory effect of PGE1 on exocytosis and allows specific characterization of the inhibitory effect of PGE1 on the subsequent compensatory endocytosis. After stimulating exocytosis, endocytosis was apparent under control conditions but was inhibited by PGE1 in a Pertussis toxin-sensitive (PTX)-insensitive manner. Dialyzing a synthetic peptide mimicking the C-terminus of the α-subunit of the heterotrimeric G-protein Gz into the cells blocked the inhibition of endocytosis by PGE1, whereas a control-randomized peptide was without effect. These results demonstrate that PGE1 inhibits endocytosis and Gz mediates the inhibition. © 2016 Society for Endocrinology.

  20. Chronic benzylamine administration in the drinking water improves glucose tolerance, reduces body weight gain and circulating cholesterol in high-fat diet-fed mice.

    PubMed

    Iffiú-Soltész, Zsuzsa; Wanecq, Estelle; Lomba, Almudena; Portillo, Maria P; Pellati, Federica; Szöko, Eva; Bour, Sandy; Woodley, John; Milagro, Fermin I; Alfredo Martinez, J; Valet, Philippe; Carpéné, Christian

    2010-04-01

    Benzylamine is found in Moringa oleifera, a plant used to treat diabetes in traditional medicine. In mammals, benzylamine is metabolized by semicarbazide-sensitive amine oxidase (SSAO) to benzaldehyde and hydrogen peroxide. This latter product has insulin-mimicking action, and is involved in the effects of benzylamine on human adipocytes: stimulation of glucose transport and inhibition of lipolysis. This study examined whether chronic, oral administration of benzylamine could improve glucose tolerance and the circulating lipid profile without increasing oxidative stress in overweight and pre-diabetic mice. The benzylamine diffusion across the intestine was verified using everted gut sacs. Then, glucose handling and metabolic markers were measured in mice rendered insulin-resistant when fed a high-fat diet (HFD) and receiving or not benzylamine in their drinking water (3600micromol/(kgday)) for 17 weeks. HFD-benzylamine mice showed lower body weight gain, fasting blood glucose, total plasma cholesterol and hyperglycaemic response to glucose load when compared to HFD control. In adipocytes, insulin-induced activation of glucose transport and inhibition of lipolysis remained unchanged. In aorta, benzylamine treatment partially restored the nitrite levels that were reduced by HFD. In liver, lipid peroxidation markers were reduced. Resistin and uric acid, surrogate plasma markers of metabolic syndrome, were decreased. In spite of the putative deleterious nature of the hydrogen peroxide generated during amine oxidation, and in agreement with its in vitro insulin-like actions found on adipocytes, the SSAO-substrate benzylamine could be considered as a potential oral agent to treat metabolic syndrome. Copyright 2010 Elsevier Ltd. All rights reserved.

  1. Tyrosine phosphorylation of Jak2 in the JH2 domain inhibits cytokine signaling.

    PubMed

    Feener, Edward P; Rosario, Felicia; Dunn, Sarah L; Stancheva, Zlatina; Myers, Martin G

    2004-06-01

    Jak family tyrosine kinases mediate signaling by cytokine receptors to regulate diverse biological processes. Although Jak2 and other Jak kinase family members are phosphorylated on numerous sites during cytokine signaling, the identity and function of most of these sites remains unknown. Using tandem mass spectroscopic analysis of activated Jak2 protein from intact cells, we identified Tyr(221) and Tyr(570) as novel sites of Jak2 phosphorylation. Phosphorylation of both sites was stimulated by cytokine treatment of cultured cells, and this stimulation required Jak2 kinase activity. While we observed no gross alteration of signaling upon mutation of Tyr(221), Tyr(570) lies within the inhibitory JH2 domain of Jak2, and mutation of this site (Jak2(Y570F)) results in constitutive Jak2-dependent signaling in the absence of cytokine stimulation and enhances and prolongs Jak2 activation during cytokine stimulation. Mutation of Tyr(570) does not alter the ability of SOCS3 to bind or inhibit Jak2, however. Thus, the phosphorylation of Tyr(570) in vivo inhibits Jak2-dependent signaling independently of SOCS3-mediated inhibition. This Tyr(570)-dependent mechanism of Jak2 inhibition likely represents an important mechanism by which cytokine function is regulated.

  2. Transcutaneous Electrical Nerve Stimulation (TENS) reduces pain, fatigue, and hyperalgesia while restoring central inhibition in primary fibromyalgia

    PubMed Central

    Dailey, Dana L; Rakel, Barbara A; Vance, Carol GT; Liebano, Richard E; Anand, Amrit S; Bush, Heather M; Lee, Kyoung S; Lee, Jennifer E; Sluka, Kathleen A

    2014-01-01

    Because TENS works by reducing central excitability and activating central inhibition pathways, we tested the hypothesis that TENS would reduce pain and fatigue and improve function and hyperalgesia in people with fibromyalgia who have enhanced central excitability and reduced inhibition. The current study used a double-blinded randomized, placebo controlled cross-over design to test effects of a single treatment of TENS in people with fibromyalgia. Three treatments were assessed in random order: active TENS, placebo TENS, no TENS. The following measures were assessed before and after each TENS treatment: pain and fatigue at rest and movement, pressure pain thresholds (PPTs), 6 minute walk test (6MWT), range of motion (ROM), five time sit to stand test (FTSTS), and single leg stance (SLS). Conditioned pain modulation (CPM) was completed at end of testing. There was a significant decrease in pain and fatigue with movement for active TENS compared to placebo and no TENS. PPTs increased at site of TENS (spine) and outside site of TENS (leg) when compared to placebo TENS or no TENS. During Active TENS CPM was significantly stronger compared to placebo TENS and no TENS. No changes in functional tasks were observed with TENS. Thus, the current study suggests TENS has short-term efficacy in relieving symptoms of fibromyalgia while the stimulator is active. Future clinical trials should examine the effects of repeated daily delivery of TENS, similar to how TENS is used clinically, on pain, fatigue, function and quality of life in individuals with fibromyalgia. PMID:23900134

  3. Subchronic treatment with grape-seed phenolics inhibits ghrelin production despite a short-term stimulation of ghrelin secretion produced by bitter-sensing flavanols.

    PubMed

    Serrano, Joan; Casanova-Martí, Àngela; Depoortere, Inge; Blay, Maria Teresa; Terra, Ximena; Pinent, Montserrat; Ardévol, Anna

    2016-12-01

    Grape-seed phenolic compounds have recently been described as satiating agents in rats when administered as a whole phenolic extract (GSPE). This satiating effect may involve the release of satiating gut hormones such as GLP-1, although a short-term increase in the orexigenic hormone ghrelin was also reported. In this study, we investigated the short- and long-term effects of GSPE in rats, focusing on the role of the main grape-seed phenolics in ghrelin secretion. GSPE produced a short-term increase in plasma ghrelin in rats after an acute treatment. A mouse ghrelinoma cell line was used to test the effects of the main pure grape-seed phenolic compounds on ghrelin release. Monomeric flavanols stimulated ghrelin secretion by activating bitter taste receptors. In contrast, gallic acid (GA) and oligomeric flavanols inhibited ghrelin release. The ghrelin-inhibiting effects of GA were confirmed in rats and in rat duodenal segments. One day after the last dose of a subchronic treatment, GSPE decreased plasma ghrelin in rats, ghrelin secretion in intestinal segments, and ghrelin mRNA expression in stomach. The sustained satiating effects of GSPE are related to a long-term decrease in ghrelin expression. GA and oligomeric flavanols play a ghrelin-inhibiting role in this process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Optogenetic versus electrical stimulation of dopamine terminals in the nucleus accumbens reveals local modulation of presynaptic release

    PubMed Central

    Melchior, James R.; Ferris, Mark J.; Stuber, Garret D.; Riddle, David R.; Jones, Sara R.

    2015-01-01

    The nucleus accumbens is highly heterogeneous, integrating regionally distinct afferent projections and accumbal interneurons, resulting in diverse local microenvironments. Dopamine (DA) neuron terminals similarly express a heterogeneous collection of terminal receptors that modulate DA signaling. Cyclic voltammetry is often used to probe DA terminal dynamics in brain slice preparations; however, this method traditionally requires electrical stimulation to induce DA release. Electrical stimulation excites all of the neuronal processes in the stimulation field, potentially introducing simultaneous, multi-synaptic modulation of DA terminal release. We used optogenetics to selectively stimulate DA terminals and used voltammetry to compare DA responses from electrical and optical stimulation of the same area of tissue around a recording electrode. We found that with multiple pulse stimulation trains, optically stimulated DA release increasingly exceeded that of electrical stimulation. Furthermore, electrical stimulation produced inhibition of DA release across longer duration stimulations. The GABAB antagonist, CGP 55845, increased electrically stimulated DA release significantly more than light stimulated release. The nicotinic acetylcholine receptor antagonist, dihydro-β-erythroidine hydrobromide, inhibited single pulse electrically stimulated DA release while having no effect on optically stimulated DA release. Our results demonstrate that electrical stimulation introduces local multi-synaptic modulation of DA release that is absent with optogenetically targeted stimulation. PMID:26011081

  5. Baicalin Inhibits Inflammatory Responses to Interleukin-1β Stimulation in Human Chondrocytes.

    PubMed

    Xing, Deguo; Gao, Hongwei; Liu, Zhonghao; Zhao, Yangyang; Gong, Mingzhi

    2017-09-01

    A mix of flavonoids comprising baicalin (BA) and catechin showed effective impacts on controlling the progress of knee osteoarthritis (OA). However, little is known about the underlying mechanisms. The influences of BA on the transcriptional levels of a series of proinflammatory genes were measured using real-time reverse transcription and polymerase chain reaction (RT-PCR). The expressions of proteins involved in nuclear factor-κB (NF-κB) activation were detected by Western blot. The in vitro results were confirmed in a mouse OA model. We found that BA treatment led to remarkable reductions of OA-related proinflammatory gene expressions, including interleukin (IL)-6, tumor necrosis factor (TNF), chemokine (C-X-C motif) ligand 1 (CXCL1), and CXCL10. The transcriptional levels of inducible nitric oxide synthase (iNOS/Nos2), matrix metalloproteinases (MMP)3, and MMP13 were significantly inhibited by BA. We measured the productions of nitrite and prostaglandin E 2 from human chondrocytes and BA was shown to reduce their productions. On the contrary, mRNA levels of aggrecan and collagen-II were enhanced by BA treatment. The inhibitory role of BA on OA may possibly be mediated by NF-κB signaling because of comparable decreases of phosphorylated (p)-p65 and p-IκBα and less p65 translocation in the nucleus after BA treatment. In OA mice model, BA significantly reduced synovitis scores and related gene expressions, including IL-6, TNF, CXCL1, CXCL10, MMP3, MMP13, and Nos2. In conclusion, BA suppresses the inflammatory responses of human chondrocytes to IL-1β stimulation, and NF-κB signaling may be involved in the mechanisms of BA functions.

  6. Inhibition of diacylglycerol lipase (DAGL) in the lateral hypothalamus of rats prevents the increase in REMS and food ingestion induced by PAR1 stimulation.

    PubMed

    Pérez-Morales, Marcel; López-Colomé, Ana María; Méndez-Díaz, Mónica; Ruiz-Contreras, Alejandra E; Prospéro-García, Oscar

    2014-08-22

    Stimulation of the protease-activated receptor 1 (PAR1) in vitro, was shown to induce synaptic retrograde signaling through the endocannabinoid 2-arachidonoylglycerol (2-AG) synthesis and activation of the cannabinoid receptor type 1 (CB1R). The activation of PAR1 by the agonist S1820 in the lateral hypothalamus (LH) increases rapid eye movement sleep (REMS) and food intake in rats, and both effects are prevented by the CB1R inverse agonist AM251. In the present study, we implanted rats with electrodes and with cannulae aimed bilaterally to the LH. We administered tetrahydrolipstatin (THL), an inhibitor of the diacylglycerol lipase (DAGL), the enzyme responsible for 2-AG synthesis, to evaluate the sleep-wake cycle and food ingestion. THL in the LH readily prevented the increase in REMS and food intake induced by PAR1 stimulation, further supporting 2-AG as an upstream activator of PAR1. Our results demonstrate that the effect of PAR1 on REMS and food intake is blocked by the inhibition of DAGL, further suggesting that PAR1 stimulation in the lateral hypothalamus of rats induces an increase in sleep and food intake through 2-AG. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Preventive and Abortive Strategies for Stimulation Based Control of Epilepsy: A Computational Model Study.

    PubMed

    Koppert, Marc; Kalitzin, Stiliyan; Velis, Demetrios; Lopes Da Silva, Fernando; Viergever, Max A

    2016-12-01

    Epilepsy is a condition in which periods of ongoing normal EEG activity alternate with periods of oscillatory behavior characteristic of epileptic seizures. The dynamics of the transitions between the two states are still unclear. Computational models provide a powerful tool to explore the underlying mechanisms of such transitions, with the purpose of eventually finding therapeutic interventions for this debilitating condition. In this study, the possibility to postpone seizures elicited by a decrease of inhibition is investigated by using external stimulation in a realistic bistable neuronal model consisting of two interconnected neuronal populations representing pyramidal cells and interneurons. In the simulations, seizures are induced by slowly decreasing the conductivity of GABA[Formula: see text] synaptic channels over time. Since the model is bistable, the system will change state from the initial steady state (SS) to the limit cycle (LS) state because of internal noise, when the inhibition falls below a certain threshold. Several state-independent stimulations paradigms are simulated. Their effectiveness is analyzed for various stimulation frequencies and intensities in combination with periodic and random stimulation sequences. The distributions of the time to first seizure in the presence of stimulation are compared with the situation without stimulation. In addition, stimulation protocols targeted to specific subsystems are applied with the objective of counteracting the baseline shift due to decreased inhibition in the system. Furthermore, an analytical model is used to investigate the effects of random noise. The relation between the strength of random noise stimulation, the control parameter of the system and the transitions between steady state and limit cycle are investigated. The study shows that it is possible to postpone epileptic activity by targeted stimulation in a realistic neuronal model featuring bistability and that it is possible to stop

  8. Supplementation of chitosan alleviates high-fat diet-enhanced lipogenesis in rats via adenosine monophosphate (AMP)-activated protein kinase activation and inhibition of lipogenesis-associated genes.

    PubMed

    Chiu, Chen-Yuan; Chan, Im-Lam; Yang, Tsung-Han; Liu, Shing-Hwa; Chiang, Meng-Tsan

    2015-03-25

    This study investigated the role of chitosan in lipogenesis in high-fat diet-induced obese rats. The lipogenesis-associated genes and their upstream regulatory proteins were explored. Diet supplementation of chitosan efficiently decreased the increased weights in body, livers, and adipose tissues in high-fat diet-fed rats. Chitosan supplementation significantly raised the lipolysis rate; attenuated the adipocyte hypertrophy, triglyceride accumulation, and lipoprotein lipase activity in epididymal adipose tissues; and decreased hepatic enzyme activities of lipid biosynthesis. Chitosan supplementation significantly activated adenosine monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation and attenuated high-fat diet-induced protein expressions of lipogenic transcription factors (PPAR-γ and SREBP1c) in livers and adipose tissues. Moreover, chitosan supplementation significantly inhibited the expressions of downstream lipogenic genes (FAS, HMGCR, FATP1, and FABP4) in livers and adipose tissues of high-fat diet-fed rats. These results demonstrate for the first time that chitosan supplementation alleviates high-fat diet-enhanced lipogenesis in rats via AMPK activation and lipogenesis-associated gene inhibition.

  9. α-Iso-cubebene exerts neuroprotective effects in amyloid beta stimulated microglia activation.

    PubMed

    Park, Sun Young; Park, Se Jin; Park, Nan Jeong; Joo, Woo Hong; Lee, Sang-Joon; Choi, Young-Whan

    2013-10-25

    Schisandra chinensis is commonly used for food and as a traditional remedy for the treatment of neuronal disorders. However, it is unclear which component of S. chinensis is responsible for its neuropharmacological effects. To answer this question, we isolated α-iso-cubebene, a dibenzocyclooctadiene lignin, from S. chinensis and determined if it has any anti-neuroinflammatory and neuroprotective properties against amyloid β-induced neuroinflammation in microglia. Microglia that are stimulated by amyloid β increased their production of pro-inflammatory cytokines and chemokines, prostaglandin E2 (PGE2), nitric oxide (NO) and reactive oxygen species (ROS) and the enzymatic activity of matrix metalloproteinase 9 (MMP-9). We found this was all inhibited by α-iso-cubebene. Consistent with these results, α-iso-cubebene inhibited the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2) and MMP-9 in amyloid β-stimulated microglia. Subsequent mechanistic studies revealed that α-iso-cubebene inhibited the phosphorylation and degradation of IκB-α, the phosphorylation and transactivity of NF-κB, and the phosphorylation of MAPK in amyloid β-stimulated microglia. These results suggest that α-iso-cubebene impairs the amyloid β-induced neuroinflammatory response of microglia by inhibiting the NF-κB and MAPK signaling pathways. Importantly, α-iso-cubebene can provide critical neuroprotection for primary cortical neurons against amyloid β-stimulated microglia-mediated neurotoxicity. To the best of our knowledge, this is the first report showing that α-iso-cubebene can provide neuroprotection against, and influence neuroinflammation triggered by, amyloid β activation of microglia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Safe Direct Current Stimulation to Expand Capabilities of Neural Prostheses

    PubMed Central

    Fridman, Gene Y.; Della Santina, Charles C.

    2014-01-01

    While effective in treating some neurological disorders, neuroelectric prostheses are fundamentally limited because they must employ charge-balanced stimuli to avoid evolution of irreversible electrochemical reactions and their byproducts at the interface between metal electrodes and body fluids. Charge-balancing is typically achieved by using brief biphasic alternating current (AC) pulses, which typically excite nearby neural tissues but cannot efficiently inhibit them. In contrast, direct current (DC) applied via a metal electrode in contact with body fluids can excite, inhibit and modulate sensitivity of neurons; however, DC stimulation is biologically unsafe because it violates “safe charge injection” limits that have long been considered unavoidable constraints. In this report, we describe the design and fabrication of a safe DC stimulator (SDCS) that overcomes this constraint. The SCDS drives DC ionic current into target tissue via salt-bridge micropipette electrodes by switching valves in phase with AC square waves applied to metal electrodes contained within the device. This approach achieves DC ionic flow through tissue while still adhering to charge-balancing constraints at each electrode-saline interface. We show the SDCS’s ability to both inhibit and excite neural activity to achieve improved dynamic range during prosthetic stimulation of the vestibular part of the inner ear in chinchillas. PMID:23476007

  11. Modulation of motor cortex excitability by paired peripheral and transcranial magnetic stimulation.

    PubMed

    Kumru, Hatice; Albu, Sergiu; Rothwell, John; Leon, Daniel; Flores, Cecilia; Opisso, Eloy; Tormos, Josep Maria; Valls-Sole, Josep

    2017-10-01

    Repetitive application of peripheral electrical stimuli paired with transcranial magnetic stimulation (rTMS) of M1 cortex at low frequency, known as paired associative stimulation (PAS), is an effective method to induce motor cortex plasticity in humans. Here we investigated the effects of repetitive peripheral magnetic stimulation (rPMS) combined with low frequency rTMS ('magnetic-PAS') on intracortical and corticospinal excitability and whether those changes were widespread or circumscribed to the cortical area controlling the stimulated muscle. Eleven healthy subjects underwent three 10min stimulation sessions: 10HzrPMS alone, applied in trains of 5 stimuli every 10s (60 trains) on the extensor carpi radialis (ECR) muscle; rTMS alone at an intensity 120% of ECR threshold, applied over motor cortex of ECR and at a frequency of 0.1Hz (60 stimuli) and magnetic PAS, i.e., paired rPMS and rTMS. We recorded motor evoked potentials (MEPs) from ECR and first dorsal interosseous (FDI) muscles. We measured resting motor threshold, motor evoked potentials (MEP) amplitude at 120% of RMT, short intracortical inhibition (SICI) at interstimulus interval (ISI) of 2ms and intracortical facilitation (ICF) at an ISI of 15ms before and immediately after each intervention. Magnetic-PAS , but not rTMS or rPMS applied separately, increased MEP amplitude and reduced short intracortical inhibition in ECR but not in FDI muscle. Magnetic-PAS can increase corticospinal excitability and reduce intracortical inhibition. The effects may be specific for the area of cortical representation of the stimulated muscle. Application of magnetic-PAS might be relevant for motor rehabilitation. Copyright © 2017 International Federation of Clinical Neurophysiology. All rights reserved.

  12. Mechanisms and targets of deep brain stimulation in movement disorders.

    PubMed

    Johnson, Matthew D; Miocinovic, Svjetlana; McIntyre, Cameron C; Vitek, Jerrold L

    2008-04-01

    Chronic electrical stimulation of the brain, known as deep brain stimulation (DBS), has become a preferred surgical treatment for medication-refractory movement disorders. Despite its remarkable clinical success, the therapeutic mechanisms of DBS are still not completely understood, limiting opportunities to improve treatment efficacy and simplify selection of stimulation parameters. This review addresses three questions essential to understanding the mechanisms of DBS. 1) How does DBS affect neuronal tissue in the vicinity of the active electrode or electrodes? 2) How do these changes translate into therapeutic benefit on motor symptoms? 3) How do these effects depend on the particular site of stimulation? Early hypotheses proposed that stimulation inhibited neuronal activity at the site of stimulation, mimicking the outcome of ablative surgeries. Recent studies have challenged that view, suggesting that although somatic activity near the DBS electrode may exhibit substantial inhibition or complex modulation patterns, the output from the stimulated nucleus follows the DBS pulse train by direct axonal excitation. The intrinsic activity is thus replaced by high-frequency activity that is time-locked to the stimulus and more regular in pattern. These changes in firing pattern are thought to prevent transmission of pathologic bursting and oscillatory activity, resulting in the reduction of disease symptoms through compensatory processing of sensorimotor information. Although promising, this theory does not entirely explain why DBS improves motor symptoms at different latencies. Understanding these processes on a physiological level will be critically important if we are to reach the full potential of this powerful tool.

  13. Design, synthesis, and structure-activity relationship study of halogen containing 2-benzylidene-1-indanone derivatives for inhibition of LPS-stimulated ROS production in RAW 264.7 macrophages.

    PubMed

    Shrestha, Aarajana; Jin Oh, Hye; Kim, Mi Jin; Pun, Nirmala Tilija; Magar, Til Bahadur Thapa; Bist, Ganesh; Choi, Hongseok; Park, Pil-Hoon; Lee, Eung-Seok

    2017-06-16

    As a continuous effort to discover new potential anti-inflammatory agents, we systematically designed and synthesized sixty-one 2-benzylidene-1-indanone derivatives with structural modification of chalcone, and evaluated their inhibitory activity on LPS-stimulated ROS production in RAW 264.7 macrophages. Systematic structure-activity relationship study revealed that hydroxyl group in C-5, C-6, or C-7 position of indanone moiety, and ortho-, meta-, or para-fluorine, trifluoromethyl, trifluoromethoxy, and bromine functionalities in phenyl ring are important for inhibition of ROS production in LPS-stimulated RAW 264.7 macrophages. Among all the tested compounds, 6-hydroxy-2-(2-(trifluoromethoxy) benzylidene)-2,3-dihydro-1H-inden-1-one (compound 44) showed the strongest inhibitory activity of ROS production. Further studies on the mode of action revealed that compound 44 potently suppressed LPS-stimulated ROS production via modulation of NADPH oxidase. The findings of this work could be useful to design 2-benzylidene-indanone based lead compounds as novel anti-inflammatory agents. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. cAMP Stimulates Transepithelial Short-Circuit Current and Fluid Transport Across Porcine Ciliary Epithelium.

    PubMed

    Cheng, Angela King-Wah; Civan, Mortimer M; To, Chi-Ho; Do, Chi-Wai

    2016-12-01

    To investigate the effects of cAMP on transepithelial electrical parameters and fluid transport across porcine ciliary epithelium. Transepithelial electrical parameters were determined by mounting freshly isolated porcine ciliary epithelium in a modified Ussing chamber. Similarly, fluid movement across intact ciliary body was measured with a custom-made fluid flow chamber. Addition of 1, 10, and 100 μM 8-Br-cAMP (cAMP) to the aqueous side (nonpigmented ciliary epithelium, NPE) induced a sustained increase in short-circuit current (Isc). Addition of niflumic acid (NFA) to the aqueous surface effectively blocked the cAMP-induced Isc stimulation. The administration of cAMP to the stromal side (pigmented ciliary epithelium, PE) triggered a significant stimulation of Isc only at 100 μM. No additive effect was observed with bilateral application of cAMP. Likewise, forskolin caused a significant stimulation of Isc when applied to the aqueous side. Concomitantly, cAMP and forskolin increased fluid transport across porcine ciliary epithelium, and this stimulation was effectively inhibited by aqueous NFA. Depleting Cl- in the bathing solution abolished the baseline Isc and inhibited the subsequent stimulation by cAMP. Pretreatment with protein kinase A (PKA) blockers (H89/KT5720) significantly inhibited the cAMP- and forskolin-induced Isc responses. Our results suggest that cAMP triggers a sustained stimulation of Cl- and fluid transport across porcine ciliary epithelium; Cl- channels in the NPE cells are potentially a cellular site for this PKA-sensitive cAMP-mediated response.

  15. Transcranial direct-current stimulation as treatment in epilepsy.

    PubMed

    Gschwind, Markus; Seeck, Margitta

    2016-12-01

    Neuromodulation (NM) is a complementary therapy for patients with drug-resistant epilepsy. Vagal nerve stimulation and deep brain stimulation of the anterior thalamus are established techniques and have shown their efficacy in lowering seizure frequency, but they are invasive and rarely render patients seizure-free. Non-invasive NM techniques are therefore increasingly investigated in a clinical context. Areas covered: Current knowledge about transcranial direct-current stimulation (tDCS) and other non-invasive NM in patients with epilepsy, based on the available animal and clinical studies from PubMed search. Expert commentary: tDCS modulates neuronal membrane potentials, and consequently alters cortical excitability. Cathodal stimulation leads to cortical inhibition, which is of particular importance in epilepsy treatment. The antiepileptic efficacy is promising but still lacks systematic studies. The beneficial effect, seen in ~20%, outlasts the duration of stimulation, indicating neuronal plasticity and is therefore of great interest to obtain long-term effects.

  16. A New Small-Molecule Antagonist Inhibits Graves' Disease Antibody Activation of the TSH Receptor

    PubMed Central

    Eliseeva, Elena; McCoy, Joshua G.; Napolitano, Giorgio; Giuliani, Cesidio; Monaco, Fabrizio; Huang, Wenwei; Gershengorn, Marvin C.

    2011-01-01

    Context: Graves' disease (GD) is caused by persistent, unregulated stimulation of thyrocytes by thyroid-stimulating antibodies (TSAbs) that activate the TSH receptor (TSHR). We previously reported the first small-molecule antagonist of human TSHR and showed that it inhibited receptor signaling stimulated by sera from four patients with GD. Objective: Our objective was to develop a better TSHR antagonist and use it to determine whether inhibition of TSAb activation of TSHR is a general phenomenon. Design: We aimed to chemically modify a previously reported small-molecule TSHR ligand to develop a better antagonist and determine whether it inhibits TSHR signaling by 30 GD sera. TSHR signaling was measured in two in vitro systems: model HEK-EM293 cells stably overexpressing human TSHRs and primary cultures of human thyrocytes. TSHR signaling was measured as cAMP production and by effects on thyroid peroxidase mRNA. Results: We tested analogs of a previously reported small-molecule TSHR inverse agonist and selected the best NCGC00229600 for further study. In the model system, NCGC00229600 inhibited basal and TSH-stimulated cAMP production. NCGC00229600 inhibition of TSH signaling was competitive even though it did not compete for TSH binding; that is, NCGC00229600 is an allosteric inverse agonist. NCGC00229600 inhibited cAMP production by 39 ± 2.6% by all 30 GD sera tested. In primary cultures of human thyrocytes, NCGC00229600 inhibited TSHR-mediated basal and GD sera up-regulation of thyroperoxidase mRNA levels by 65 ± 2.0%. Conclusion: NCGC00229600, a small-molecule allosteric inverse agonist of TSHR, is a general antagonist of TSH receptor activation by TSAbs in GD patient sera. PMID:21123444

  17. A new small-molecule antagonist inhibits Graves' disease antibody activation of the TSH receptor.

    PubMed

    Neumann, Susanne; Eliseeva, Elena; McCoy, Joshua G; Napolitano, Giorgio; Giuliani, Cesidio; Monaco, Fabrizio; Huang, Wenwei; Gershengorn, Marvin C

    2011-02-01

    Graves' disease (GD) is caused by persistent, unregulated stimulation of thyrocytes by thyroid-stimulating antibodies (TSAbs) that activate the TSH receptor (TSHR). We previously reported the first small-molecule antagonist of human TSHR and showed that it inhibited receptor signaling stimulated by sera from four patients with GD. Our objective was to develop a better TSHR antagonist and use it to determine whether inhibition of TSAb activation of TSHR is a general phenomenon. We aimed to chemically modify a previously reported small-molecule TSHR ligand to develop a better antagonist and determine whether it inhibits TSHR signaling by 30 GD sera. TSHR signaling was measured in two in vitro systems: model HEK-EM293 cells stably overexpressing human TSHRs and primary cultures of human thyrocytes. TSHR signaling was measured as cAMP production and by effects on thyroid peroxidase mRNA. We tested analogs of a previously reported small-molecule TSHR inverse agonist and selected the best NCGC00229600 for further study. In the model system, NCGC00229600 inhibited basal and TSH-stimulated cAMP production. NCGC00229600 inhibition of TSH signaling was competitive even though it did not compete for TSH binding; that is, NCGC00229600 is an allosteric inverse agonist. NCGC00229600 inhibited cAMP production by 39 ± 2.6% by all 30 GD sera tested. In primary cultures of human thyrocytes, NCGC00229600 inhibited TSHR-mediated basal and GD sera up-regulation of thyroperoxidase mRNA levels by 65 ± 2.0%. NCGC00229600, a small-molecule allosteric inverse agonist of TSHR, is a general antagonist of TSH receptor activation by TSAbs in GD patient sera.

  18. Anesthetic agent-specific effects on synaptic inhibition.

    PubMed

    MacIver, M Bruce

    2014-09-01

    Anesthetics enhance γ-aminobutyric acid (GABA)-mediated inhibition in the central nervous system. Different agents have been shown to act on tonic versus synaptic GABA receptors to different degrees, but it remains unknown whether different forms of synaptic inhibition are also differentially engaged. With this in mind, we tested the hypothesis that different types of GABA-mediated synapses exhibit different anesthetic sensitivities. The present study compared effects produced by isoflurane, halothane, pentobarbital, thiopental, and propofol on paired-pulse GABAA receptor-mediated synaptic inhibition. Effects on glutamate-mediated facilitation were also studied. Synaptic responses were measured in rat hippocampal brain slices. Orthodromic paired-pulse stimulation was used to assess anesthetic effects on either glutamate-mediated excitatory inputs or GABA-mediated inhibitory inputs to CA1 neurons. Antidromic stimulation was used to assess anesthetic effects on CA1 background excitability. Agents were studied at equieffective concentrations for population spike depression to compare their relative degree of effect on synaptic inhibition. Differing degrees of anesthetic effect on paired-pulse facilitation at excitatory glutamate synapses were evident, and blocking GABA inhibition revealed a previously unseen presynaptic action for pentobarbital. Although all 5 anesthetics depressed synaptically evoked excitation of CA1 neurons, the involvement of enhanced GABA-mediated inhibition differed considerably among agents. Single-pulse inhibition was enhanced by propofol, thiopental, and pentobarbital, but only marginally by halothane and isoflurane. In contrast, isoflurane enhanced paired-pulse inhibition strongly, as did thiopental, but propofol, pentobarbital, and halothane were less effective. These observations support the idea that different GABA synapses use receptors with differing subunit compositions and that anesthetics exhibit differing degrees of selectivity for

  19. Saponins from stems and leaves of Panax ginseng prevent obesity via regulating thermogenesis, lipogenesis and lipolysis in high-fat diet-induced obese C57BL/6 mice.

    PubMed

    Chen, Guilin; Li, Haijun; Zhao, Yan; Zhu, Hongyan; Cai, Enbo; Gao, Yugang; Liu, Shuangli; Yang, He; Zhang, Lianxue

    2017-08-01

    In this study, high-fat diet (HFD)-induced obesity in mouse model was used to evaluate the dietary effect of saponins from stems and leaves of Panax ginseng (SLG), and to explore its mechanism of action in producing anti-obesity effects. The results indicate that SLG showed significant anti-obesity effects in diet-induced obese mice, represented by decreased serum levels of free fatty acids (FFA), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL)-cholesterol, glucose, leptin and insulin, as well as a reduction in overall body and liver weight, epididymal adipose tissue weight, and food efficiency, and inhibition of abnormal increases in acyl carnitine levels normally caused by an HFD. Additionally, the down-regulated expression of PPARγ, FAS, CD36, FATP2 and up-regulated expression of CPT-1, UCP-2, PPARα, HSL, and ATGL in liver tissue was induced by SLG. In addition, the SLG groups showed decreased PPARγ, aP2 and leptin mRNA levels and increased expression of PPARα, PGC-1α, UCP-1 and UCP-3 genes in adipose tissues, compared with the HFD group. In short, SLG may play a key role in producing anti-obesity effects in mice fed an HFD, and its mechanism may be related to regulation of thermogenesis, lipogenesis and lipolysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Intraglomerular inhibition maintains mitral cell response contrast across input frequencies.

    PubMed

    Shao, Zuoyi; Puche, Adam C; Shipley, Michael T

    2013-11-01

    Odor signals are transmitted to the olfactory bulb by olfactory nerve (ON) synapses onto mitral/tufted cells (MTCs) and external tufted cells (ETCs); ETCs provide additional feed-forward excitation to MTCs. Both are strongly regulated by intraglomerular inhibition that can last up to 1 s and, when blocked, dramatically increases ON-evoked MC spiking. Intraglomerular inhibition thus limits the magnitude and duration of MC spike responses to sensory input. In vivo, sensory input is repetitive, dictated by sniffing rates from 1 to 8 Hz, potentially summing intraglomerular inhibition. To investigate this, we recorded MTC responses to 1- to 8-Hz ON stimulation in slices. Inhibitory postsynaptic current area (charge) following each ON stimulation was unchanged from 1 to 5 Hz and modestly paired-pulse attenuated at 8 Hz, suggesting there is no summation and only limited decrement at the highest input frequencies. Next, we investigated frequency independence of intraglomerular inhibition on MC spiking. MCs respond to single ON shocks with an initial spike burst followed by reduced spiking decaying to baseline. Upon repetitive ON stimulation peak spiking is identical across input frequencies but the ratio of peak-to-minimum rate before the stimulus (max-min) diminishes from 30:1 at 1 Hz to 15:1 at 8 Hz. When intraglomerular inhibition is selectively blocked, peak spike rate is unchanged but trough spiking increases markedly decreasing max-min firing ratios from 30:1 at 1 Hz to 2:1 at 8 Hz. Together, these results suggest intraglomerular inhibition is relatively frequency independent and can "sharpen" MC responses to input across the range of frequencies. This suggests that glomerular circuits can maintain "contrast" in MC encoding during sniff-sampled inputs.