Anticryptococcal effect of amphotericin B is mediated through macrophage production of nitric oxide.

PubMed Central

Tohyama, M; Kawakami, K; Saito, A

1996-01-01

Amphotericin B (AmB) is a classical antifungal drug and one of the most effective antifungal drugs for the treatment of systemic fungal infection. It is also known to have various immunomodulating activities other than its direct antifungal effect. In the present study, we demonstrated that AmB augmented gamma interferon (IFN-gamma)-induced killing potentials of murine peritoneal macrophages against Cryptococcus neoformans in a dose-dependent manner. This effect was strongly blocked by NG-monomethyl-L-arginine, a competitive inhibitor of nitric oxide (NO) synthesis. In addition, AmB markedly augmented macrophage NO production induced by IFN-gamma with a dose-response curve similar to that seen with its effect on the anticryptococcal activity. These effects were partially mediated by either tumor necrosis factor alpha or interleukin-1, because AmB enhanced IFN-gamma-induced production of these cytokines by macrophages and their specific antibodies partially inhibited the AmB-induced enhancement of NO generation when they were used separately. Our results indicate that AmB induces the production of tumor necrosis factor alpha and IL-1 by macrophages and augments their anticryptococcal activity through triggering the NO-dependent pathway. PMID:8843304

Model for Stress-induced Protein Degradation in Lemna minor1

PubMed Central

Cooke, Robert J.; Roberts, Keith; Davies, David D.

1980-01-01

Transfer of Lemna minor fronds to adverse or stress conditions produces a large increase in the rate of protein degradation. Cycloheximide partially inhibits stress-induced protein degradation and also partially inhibits the protein degradation which occurs in the absence of stress. The increased protein degradation does not appear to be due to an increase in activity of soluble proteolytic enzymes. Biochemical evidence indicates that stress, perhaps acting via hormones, affects the permeability of certain membranes, particularly the tonoplast. A general model for stress-induced protein degradation is presented in which changes in membrane properties allow vacuolar proteolytic enzymes increased access to cytoplasmic proteins. PMID:16661588

Soluble FGFR4 extracellular domain inhibits FGF19-induced activation of FGFR4 signaling and prevents nonalcoholic fatty liver disease

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

Chen, Qiang; The First Affiliated Hospital of Xiamen University, Xiamen; Jiang, Yuan

2011-06-17

Highlights: {yields} Soluble FGFR4 extracellular domain (FGFR4-ECD) was effectively expressed. {yields} FGFR4-ECD inhibited FGF19-induced activation of FGFR4 signaling. {yields} FGFR4-ECD reduced palmitic acid-induced steatosis of HepG2 cells. {yields} FGFR4-ECD reduced tetracycline-induced fatty liver in mice. {yields} FGFR4-ECD partially restored tetracycline-repressed PPAR{alpha} expression. -- Abstract: Fibroblast growth factor receptor 4 (FGFR4) is a transmembrane tyrosine kinase receptor that plays a crucial role in the regulation of hepatic bile acid and lipid metabolism. FGFR4 underlies high-fat diet-induced hepatic steatosis, suggesting that inhibition of FGFR4 activation may be an effective way to prevent or treat nonalcoholic fatty liver disease (NAFLD). To determine whethermore » neutralization of FGFR4 ligands by soluble FGFR4 extracellular domain (FGFR4-ECD) can inhibit the activation of FGFR4, we constructed FGFR4-ECD expression vector and showed that FGFR4-ECD was effectively expressed in cells and secreted into culture medium. FGFR4-ECD inhibited FGF19-induced activation of FGFR4 signaling and reduced steatosis of HepG2 induced by palmitic acid in vitro. Furthermore, in a tetracycline-induced fatty liver model, expression of FGFR4-ECD in mouse liver reduced the accumulation of hepatic lipids and partially restored the expression of peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}), which promotes the mitochondrial fatty acid beta-oxidation but is repressed by tetracycline. Taken together, these results demonstrate that FGFR4-ECD can block FGFR4 signaling and prevent hepatic steatosis, highlighting the potential value of inhibition of FGFR4 signaling as a method for therapeutic intervention against NAFLD.« less

Ameliorative role of gemfibrozil against partial abdominal aortic constriction-induced cardiac hypertrophy in rats.

PubMed

Singh, Amrit Pal; Singh, Randhir; Krishan, Pawan

2015-04-01

Fibrates are peroxisome proliferator-activated receptor-α agonists and are clinically used for treatment of dyslipidemia and hypertriglyceridemia. Fenofibrate is reported as a cardioprotective agent in various models of cardiac dysfunction; however, limited literature is available regarding the role of gemfibrozil as a possible cardioprotective agent, especially in a non-obese model of cardiac remodelling. The present study investigated the role of gemfibrozil against partial abdominal aortic constriction-induced cardiac hypertrophy in rats. Cardiac hypertrophy was induced by partial abdominal aortic constriction in rats and they survived for 4 weeks. The cardiac hypertrophy was assessed by measuring left ventricular weight to body weight ratio, left ventricular wall thickness, and protein and collagen content. The oxidative stress in the cardiac tissues was assessed by measuring thiobarbituric acid-reactive substances, superoxide anion generation, and reduced glutathione level. The haematoxylin-eosin and picrosirius red staining was used to observe cardiomyocyte diameter and collagen deposition, respectively. Moreover, serum levels of cholesterol, high-density lipoproteins, triglycerides, and glucose were also measured. Gemfibrozil (30 mg/kg, p.o.) was administered since the first day of partial abdominal aortic constriction and continued for 4 weeks. The partial abdominal aortic constriction-induced cardiac oxidative stress and hypertrophy are indicated by significant change in various parameters used in the present study that were ameliorated with gemfibrozil treatment in rats. No significant change in serum parameters was observed between various groups used in the present study. It is concluded that gemfibrozil ameliorates partial abdominal aortic constriction-induced cardiac oxidative stress and hypertrophy and in rats.

Methionine and serine synergistically suppress hyperhomocysteinemia induced by choline deficiency, but not by guanidinoacetic acid, in rats fed a low casein diet.

PubMed

Liu, Yi-qun; Liu, Ying; Morita, Tatsuya; Sugiyama, Kimio

2011-01-01

The effects of dietary supplementation with 0.5% methionine, 2.5% serine, or both on hyperhomocysteinemia induced by deprivation of dietary choline or by dietary addition of 0.5% guanidinoacetic acid (GAA) were investigated in rats fed a 10% casein diet. Hyperhomocysteinemia induced by choline deprivation was not suppressed by methionine alone and was only partially suppressed by serine alone, whereas it was completely suppressed by a combination of methionine and serine, suggesting a synergistic effect of methionine and serine. Fatty liver was also completely prevented by the combination of methionine and serine. Compared with methionine alone, the combination of methionine and serine decreased hepatic S-adenosylhomocysteine and homocysteine concentrations and increased hepatic betaine and serine concentrations and betaine-homocysteine S-methyltransferase activity. GAA-induced hyperhomocysteinemia was partially suppressed by methionine alone, but no interacting effect of methionine and serine was detected. In contrast, GAA-induced fatty liver was completely prevented by the combination of methionine and serine. These results indicate that a combination of methionine and serine is effective in suppressing both hyperhomocysteinemia and fatty liver induced by choline deprivation, and that methionine alone is effective in suppressing GAA-induced hyperhomocysteinemia partially.

Novel Derivative of Benzofuran Induces Cell Death Mostly by G2/M Cell Cycle Arrest through p53-dependent Pathway but Partially by Inhibition of NF-κB*

PubMed Central

Manna, Sunil K.; Bose, Julie S.; Gangan, Vijay; Raviprakash, Nune; Navaneetha, Thota; Raghavendra, Pongali B.; Babajan, Banaganapalli; Kumar, Chitta S.; Jain, Swatantra K.

2010-01-01

The Dracaena resin is widely used in traditional medicine as an anticancer agent, and benzofuran lignan is the active component. In this report, we provide evidence that the synthetic derivative of benzofuran lignan (Benfur) showed antitumor activities. It induced apoptosis in p53-positive cells. Though it inhibited endotoxin-induced nuclear factor κB (NF-κB) activation in both p53-positive and -negative cells, the activation of caspase 3 was observed in p53-positive cells. It showed partial cell death effect in both p53-positive and -negative cells through inhibition of NF-κB. Cell cycle analysis using flow cytometry showed that treatment with this novel benozofuran lignan derivative to Jurkat T-cells, but not U-937 cells, resulted in a G2/M arrest in a dose- and time-dependent manner. It increased amounts of p21, p27, and cyclin B, but not phospho-Rb through p53 nuclear translocation in Jurkat T-cells, but not in U-937 cells. It inhibited amounts of MDM2 (murine double minute 2) by repressing the transcription factor Sp1, which was also proved in silico. It induced cell death in tumor cells, but not in primary T-cells. Overall, our data suggest that Benfur-mediated cell death is partially dependent upon NF-κB, but predominantly dependent on p53. Thus, this novel benzofuran lignan derivative can be effective chemopreventive or chemotherapeutic agent against malignant T-cells. PMID:20472557

Suppression Effects of Betaine-Enriched Spinach on Hyperhomocysteinemia Induced by Guanidinoacetic Acid and Choline Deficiency in Rats

PubMed Central

Liu, Yi-Qun; Jia, Zheng; Han, Feng; Inakuma, Takahiro; Miyashita, Tatsuya; Sugiyama, Kimio; Sun, Li-Cui; Xiang, Xue-Song; Huang, Zhen-Wu

2014-01-01

Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA) addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25C) was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S) was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine β-synthase (CBS) in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation. PMID:25250392

Suppression effects of betaine-enriched spinach on hyperhomocysteinemia induced by guanidinoacetic acid and choline deficiency in rats.

PubMed

Liu, Yi-Qun; Jia, Zheng; Han, Feng; Inakuma, Takahiro; Miyashita, Tatsuya; Sugiyama, Kimio; Sun, Li-Cui; Xiang, Xue-Song; Huang, Zhen-Wu

2014-01-01

Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA) addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25 C) was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S) was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine β-synthase (CBS) in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

REV-ERBs agonism suppresses osteoclastogenesis and prevents ovariectomy-induced bone loss partially via FABP4 upregulation.

PubMed

Song, Chao; Tan, Peng; Zhang, Zheng; Wu, Wei; Dong, Yonghui; Zhao, Liming; Liu, Huiyong; Guan, Hanfeng; Li, Feng

2018-01-22

REV-ERBs (REV-ERBα and REV-ERBβ) are transcription repressors and circadian regulators. Previous investigations have shown that REV-ERBs repress the expression of target genes, including MMP9 and CX3CR1, in macrophages. Because MMP9 and CX3CR1 reportedly participate in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis, we inferred that REV-ERBs might play a role in osteoclastogenesis. In the present study, we found that the REV-ERBα level decreased significantly during RANKL-induced osteoclast differentiation from primary bone marrow-derived macrophages (BMMs). REV-ERBα knockdown by small interfering RNA in BMMs resulted in the enhanced formation of osteoclasts, whereas REV-ERBβ knockdown showed no effect on osteoclast differentiation. Moreover, the REV-ERB agonist SR9009 inhibited osteoclast differentiation and bone resorption. Intraperitoneal SR9009 administration prevented ovariectomy-induced bone loss; this effect was accompanied by decreased serum RANKL and C-terminal telopeptide of type I collagen levels and increased osteoprotegerin levels. Further investigation revealed that NF-κB and MAPK activation and nuclear factor of activated T cells, cytoplasmic 1, and c-fos expression were suppressed by SR9009. The level of reactive oxygen species was also decreased by SR9009, with NADPH oxidase subunits also being down-regulated. In addition, an expression microarray showed that FABP4, an intracellular lipid-binding protein, was up-regulated by REV-ERB agonism. BMS309403, an inhibitor of FABP4, partially prevented the suppression of osteoclastogenesis by SR9009 through stabilizing phosphorylation of p65. To summarize, our results proved that the REV-ERB agonism inhibited osteoclastogenesis partially via FABP4 up-regulation.-Song, C., Tan, P., Zhang, Z., Wu, W., Dong, Y., Zhao, L., Liu, H., Guan, H., Li, F. REV-ERBs agonism suppresses osteoclastogenesis and prevents ovariectomy-induced bone loss partially via FABP4 upregulation.

N-acetyl-L-cysteine protects against cadmium-induced neuronal apoptosis by inhibiting ROS-dependent activation of Akt/mTOR pathway in mouse brain

PubMed Central

Chen, Sujuan; Ren, Qian; Zhang, Jinfei; Ye, Yangjing; Zhang, Zhen; Xu, Yijiao; Guo, Min; Ji, Haiyan; Xu, Chong; Gu, Chenjian; Gao, Wei; Huang, Shile; Chen, Long

2014-01-01

Aims This study explores the neuroprotective effects and mechanisms of N-acetyl-L-cysteine (NAC) in mice exposed to cadmium (Cd). Methods NAC (150 mg/kg) was intraperitoneally administered to mice exposed to Cd (10-50 mg/L) in drinking water for 6 weeks. The changes of cell damage and death, reactive oxygen species (ROS), antioxidant enzymes, as well as Akt/mammalian target of rapamycin (mTOR) signaling pathway in brain neurons were assessed. To verify the role of mTOR activation in Cd-induced neurotoxicity, mice also received a subacute regimen of intraperitoneally administered Cd (1 mg/kg) with/without rapamycin (7.5 mg/kg) for 11 days. Results Chronic exposure of mice to Cd induced brain damage or neuronal cell death, due to ROS induction. Co-administration of NAC significantly reduced Cd levels in the plasma and brain of the animals. NAC prevented Cd-induced ROS and significantly attenuated Cd-induced brain damage or neuronal cell death. The protective effect of NAC was mediated, at least partially, by elevating the activities of Cu/Zn-superoxide dismutase, catalase and glutathione peroxidase, as well as the level of glutathione in the brain. Furthermore, Cd-induced activation of Akt/mTOR pathway in the brain was also inhibited by NAC. Rapamycin in vitro and in vivo protected against Cd-induced neurotoxicity. Conclusions NAC protects against Cd-induced neuronal apoptosis in mouse brain partially by inhibiting ROS-dependent activation of Akt/mTOR pathway. The findings highlight that NAC may be exploited for prevention and treatment of Cd-induced neurodegenerative diseases. PMID:24299490

Spirulan from blue-green algae inhibits fibrin and blood clots: its potent antithrombotic effects.

PubMed

Choi, Jun-Hui; Kim, Seung; Kim, Sung-Jun

2015-05-01

We investigated in vitro and in vivo fibrinolytic and antithrombotic activity of spirulan and analyzed its partial biochemical properties. Spirulan, a sulfated polysaccharide from the blue-green alga Arthrospira platensis, exhibits antithrombotic potency. Spirulan showed a strong fibrin zymogram lysis band corresponding to its molecular mass. It specifically cleaved Aα and Bβ, the major chains of fibrinogen. Spirulan directly decreased the activity of thrombin and factor X activated (FXa), procoagulant proteins. In vitro assays using human fibrin and mouse blood clots showed fibrinolytic and hemolytic activities of spirulan. Spirulan (2 mg/kg) showed antithrombotic effects in the ferric chloride (FeCl3 )-induced carotid arterial thrombus model and collagen and epinephrine-induced pulmonary thromboembolism mouse model. These results may be attributable to the prevention of thrombus formation and partial lysis of thrombus. Therefore, we suggest that spirulan may be a potential antithrombotic agent for thrombosis-related diseases. © 2015 Wiley Periodicals, Inc.

Conversion of partially reprogrammed cells to fully pluripotent stem cells is associated with further activation of stem cell maintenance- and gamete generation-related genes.

PubMed

Kim, Jong Soo; Choi, Hyun Woo; Choi, Sol; Seo, Han Geuk; Moon, Sung-Hwan; Chung, Hyung-Min; Do, Jeong Tae

2014-11-01

Somatic cells are reprogrammed to induced pluripotent stem cells (iPSCs) by overexpression of a combination of defined transcription factors. We generated iPSCs from mouse embryonic fibroblasts (with Oct4-GFP reporter) by transfection of pCX-OSK-2A (Oct4, Sox2, and Klf4) and pCX-cMyc vectors. We could generate partially reprogrammed cells (XiPS-7), which maintained more than 20 passages in a partially reprogrammed state; the cells expressed Nanog but were Oct4-GFP negative. When the cells were transferred to serum-free medium (with serum replacement and basic fibroblast growth factor), the XiPS-7 cells converted to Oct4-GFP-positive iPSCs (XiPS-7c, fully reprogrammed cells) with ESC-like properties. During the conversion of XiPS-7 to XiPS-7c, we found several clusters of slowly reprogrammed genes, which were activated at later stages of reprogramming. Our results suggest that partial reprogrammed cells can be induced to full reprogramming status by serum-free medium, in which stem cell maintenance- and gamete generation-related genes were upregulated. These long-term expandable partially reprogrammed cells can be used to verify the mechanism of reprogramming.

Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity.

PubMed

Hasegawa, Yasushi; Inoue, Tatsuro; Kawaminami, Satoshi; Fujita, Miho

2016-07-01

To evaluate the neuroprotective effects of the organic components of scallop shells (scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5,10-imine (MK801). Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test, the Morris water maze test, and the open field test. Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test. Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex. Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine. Scallop shell extract also suppressed the increase in locomotor activity induced by MK801. Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

Glucocorticoid suppresses the canonical Wnt signal in cultured human osteoblasts

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

Ohnaka, Keizo; Tanabe, Mizuho; Kawate, Hisaya

2005-04-01

To explore the mechanism of glucocorticoid-induced osteoporosis, we investigated the effect of glucocorticoid on canonical Wnt signaling that emerged as a novel key pathway for promoting bone formation. Wnt3a increased the T-cell factor (Tcf)/lymphoid enhancer factor (Lef)-dependent transcriptional activity in primary cultured human osteoblasts. Dexamethasone suppressed this transcriptional activity in a dose-dependent manner, while 1,25-dihydroxyvitamin D3 increased this transcriptional activity. LiCl, an inhibitor of glycogen synthase kinase-3{beta}, also enhanced the Tcf/Lef-dependent transcriptional activity, which was, however, not inhibited by dexamethasone. The addition of anti-dickkopf-1 antibody partially restored the transcriptional activity suppressed by dexamethasone. Dexamethasone decreased the cytosolic amount of {beta}-cateninmore » accumulated by Wnt3a and also inhibited the nuclear translocation of {beta}-catenin induced by Wnt3a. These data suggest that glucocorticoid suppresses the canonical Wnt signal in cultured human osteoblasts, partially through the enhancement of the dickkopf-1 production.« less

Gingerol Inhibits Serum-Induced Vascular Smooth Muscle Cell Proliferation and Injury-Induced Neointimal Hyperplasia by Suppressing p38 MAPK Activation.

PubMed

Jain, Manish; Singh, Ankita; Singh, Vishal; Maurya, Preeti; Barthwal, Manoj Kumar

2016-03-01

Gingerol inhibits growth of cancerous cells; however, its role in vascular smooth muscle cell (VSMC) proliferation is not known. The present study investigated the effect of gingerol on VSMC proliferation in cell culture and during neointima formation after balloon injury. Rat VSMCs or carotid arteries were harvested at 15 minutes, 30 minutes, 1, 6, 12, and 24 hours of fetal bovine serum (FBS; 10%) stimulation or balloon injury, respectively. Gingerol prevented FBS (10%)-induced proliferation of VSMCs in a dose-dependent manner (50 μmol/L-400 μmol/L). The FBS-induced proliferating cell nuclear antigen (PCNA) upregulation and p27(Kip1) downregulation were also attenuated in gingerol (200 μmol/L) pretreated cells. Fetal bovine serum-induced p38 mitogen-activated protein kinase (MAPK) activation, PCNA upregulation, and p27(Kip1) downregulation were abrogated in gingerol (200 μmol/L) and p38 MAPK inhibitor (SB203580, 10 μmol/L) pretreated cells. Balloon injury induced time-dependent p38 MAPK activation in the carotid artery. Pretreatment with gingerol (200 μmol/L) significantly attenuated injury-induced p38 MAPK activation, PCNA upregulation, and p27(Kip1) downregulation. After 14 days of balloon injury, intimal thickening, neointimal proliferation, and endothelial dysfunction were significantly prevented in gingerol pretreated arteries. In isolated organ bath studies, gingerol (30 nmol/L-300 μmol/L) inhibited phenylephrine-induced contractions and induced dose-dependent relaxation of rat thoracic aortic rings in a partially endothelium-dependent manner. Gingerol prevented FBS-induced VSMC proliferation and balloon injury-induced neointima formation by regulating p38 MAPK. Vasodilator effect of gingerol observed in the thoracic aorta was partially endothelium dependent. Gingerol is thus proposed as an attractive agent for modulating VSMC proliferation, vascular reactivity, and progression of vascular proliferative diseases. © The Author(s) 2015.

Curcumin induces endoplasmic reticulum stress-associated apoptosis in human papillary thyroid carcinoma BCPAP cells via disruption of intracellular calcium homeostasis.

PubMed

Zhang, Li; Cheng, Xian; Xu, Shichen; Bao, Jiandong; Yu, Huixin

2018-06-01

Thyroid cancer is the most common endocrine tumor. Our previous studies have demonstrated that curcumin can induce apoptosis in human papillary thyroid carcinoma BCPAP cells. However, the underlined mechanism has not been clearly elucidated. Endoplasmic reticulum (ER) is a major organelle for synthesis, maturation, and folding proteins as well as a large store for Ca. Overcoming chronically activated ER stress by triggering pro-apoptotic pathways of the unfolded protein response (UPR) is a novel strategy for cancer therapeutics. Our study aimed to uncover the ER stress pathway involved in the apoptosis caused by curcumin. BCPAP cells were treated with different doses of curcumin (12.5-50 μM). Annexin V/PI double staining was used to determine cell apoptosis. Rhod-2/AM calcium fluorescence probe assay was performed to measure the calcium level of endoplasmic reticulum. Western blot was used to examine the expression of ER stress marker C/EBP homologous protein 10 (CHOP) and glucose-regulated protein 78 (GRP78). X-box binding protein1 (XBP-1) spliced form was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). Curcumin significantly inhibited anchorage-independent cell growth and induced apoptosis in BCPAP cells. Curcumin induced ER stress and UPR responses in a dose- and time-dependent manner, and the chemical chaperone 4-phenylbutyrate (4-PBA) partially reversed the antigrowth activity of curcumin. Moreover, curcumin significantly increased inositol-requiring enzyme 1α (IRE1α) phosphorylation and XBP-1 mRNA splicing to induce a subsets of ER chaperones. Increased cleavage of activating transcription factor 6 (ATF6), which enhances expression of its downstream target CHOP was also observed. Furthermore, curcumin induced intracellular Ca influx through inhibition of the sarco-endoplasmic reticulum ATPase 2A (SERCA2) pump. The increased cytosolic Ca then bound to calmodulin to activate calcium/calmodulin-dependent protein kinase II (CaMKII) signaling, leading to mitochondrial apoptosis pathway activation. Ca chelator BAPTA partially reversed curcumin-induced ER stress and growth suppression, confirming the possible involvement of calcium homeostasis disruption in this response. Curcumin inhibits thyroid cancer cell growth, at least partially, through ER stress-associated apoptosis. Our observations provoked that ER stress activation may be a promising therapeutic target for thyroid cancer treatment.(Figure is included in full-text article.).

Rotenone Induction of Hydrogen Peroxide Inhibits mTOR-mediated S6K1 and 4E-BP1/eIF4E Pathways, Leading to Neuronal Apoptosis

PubMed Central

Zhou, Qian; Liu, Chunxiao; Liu, Wen; Zhang, Hai; Zhang, Ruijie; Liu, Jia; Zhang, Jinfei; Xu, Chong; Liu, Lei; Huang, Shile; Chen, Long

2015-01-01

Rotenone, a common pesticide and inhibitor of mitochondrial complex I, induces loss of dopaminergic neurons and consequential aspects of Parkinson’s disease (PD). However, the exact mechanism of rotenone neurotoxicity is not fully elucidated. Here, we show that rotenone induced reactive oxygen species (ROS), leading to apoptotic cell death in PC12 cells and primary neurons. Pretreatment with catalase (CAT), a hydrogen peroxide-scavenging enzyme, attenuated rotenone-induced ROS and neuronal apoptosis, implying hydrogen peroxide (H2O2) involved, which was further verified by imaging intracellular H2O2 using a peroxide-selective probe H2DCFDA. Using thenoyltrifluoroacetone (TTFA), antimycin A, or Mito-TEMPO, we further demonstrated rotenone-induced mitochondrial H2O2-dependent neuronal apoptosis. Rotenone dramatically inhibited mTOR-mediated phosphorylation of S6K1 and 4E-BP1, which was also attenuated by CAT in the neuronal cells. Of interest, ectopic expression of wild-type mTOR or constitutively active S6K1, or downregulation of 4E-BP1 partially prevented rotenone-induced H2O2 and cell apoptosis. Furthermore, we noticed that rotenone-induced H2O2 was linked to the activation of caspase-3 pathway. This was evidenced by the finding that pretreatment with CAT partially blocked rotenone-induced cleavages of caspase-3 and poly (ADP-ribose) polymerase. Of note, zVAD-fmk, a pan caspase inhibitor, only partially prevented rotenone-induced apoptosis in PC12 cells and primary neurons. Expression of mTOR-wt, S6K1-ca, or silencing 4E-BP1 potentiated zVAD-fmk protection against rotenone-induced apoptosis in the cells. The results indicate that rotenone induction of H2O2 inhibits mTOR-mediated S6K1 and 4E-BP1/eIF4E pathways, resulting in caspase-dependent and -independent apoptosis in neuronal cells. Our findings suggest that rotenone-induced neuronal loss in PD may be prevented by activating mTOR signaling and/or administering antioxidants. PMID:25304210

Hepatoprotective activity of Phyllanthus reticulatus.

PubMed

Das, Biplab K; Bepary, Sukumar; Datta, Bidyut K; Chowdhury, Ak Azad; Ali, Mohammad Shawkat; Rouf, Abu Shara Shamsur

2008-10-01

Two partially purified organic fractions designated by PR1 and PR2 of the fat free ethanol (95%) extract of aerial parts of Phyllanthus reticulatus were tested for the hepatoprotective activity in rats against CCl(4)-induced liver damage. The rats receiving the fractions showed promising hepatoprotective activity as evident from significant changes of pentobarbital-induced sleeping time, changes in serum levels of sGPT, sGOT, sALP and bilirubin and also from histopathological changes as compared to CCl(4)-intoxicated rats.

Osmostress induces autophosphorylation of Hog1 via a C-terminal regulatory region that is conserved in p38α.

PubMed

Maayan, Inbal; Beenstock, Jonah; Marbach, Irit; Tabachnick, Shira; Livnah, Oded; Engelberg, David

2012-01-01

Many protein kinases require phosphorylation at their activation loop for induction of catalysis. Mitogen-activated protein kinases (MAPKs) are activated by a unique mode of phosphorylation, on neighboring Tyrosine and Threonine residues. Whereas many kinases obtain their activation via autophosphorylation, MAPKs are usually phosphorylated by specific, dedicated, MAPK kinases (MAP2Ks). Here we show however, that the yeast MAPK Hog1, known to be activated by the MAP2K Pbs2, is activated in pbs2Δ cells via an autophosphorylation activity that is induced by osmotic pressure. We mapped a novel domain at the Hog1 C-terminal region that inhibits this activity. Removal of this domain provides a Hog1 protein that is partially independent of MAP2K, namely, partially rescues osmostress sensitivity of pbs2Δ cells. We further mapped a short domain (7 amino acid residues long) that is critical for induction of autophosphorylation. Its removal abolishes autophosphorylation, but maintains Pbs2-mediated phosphorylation. This 7 amino acids stretch is conserved in the human p38α. Similar to the case of Hog1, it's removal from p38α abolishes p38α's autophosphorylation capability, but maintains, although reduces, its activation by MKK6. This study joins a few recent reports to suggest that, like many protein kinases, MAPKs are also regulated via induced autoactivation.

Osmostress Induces Autophosphorylation of Hog1 via a C-Terminal Regulatory Region That Is Conserved in p38α

PubMed Central

Maayan, Inbal; Beenstock, Jonah; Marbach, Irit; Tabachnick, Shira; Livnah, Oded; Engelberg, David

2012-01-01

Many protein kinases require phosphorylation at their activation loop for induction of catalysis. Mitogen-activated protein kinases (MAPKs) are activated by a unique mode of phosphorylation, on neighboring Tyrosine and Threonine residues. Whereas many kinases obtain their activation via autophosphorylation, MAPKs are usually phosphorylated by specific, dedicated, MAPK kinases (MAP2Ks). Here we show however, that the yeast MAPK Hog1, known to be activated by the MAP2K Pbs2, is activated in pbs2Δ cells via an autophosphorylation activity that is induced by osmotic pressure. We mapped a novel domain at the Hog1 C-terminal region that inhibits this activity. Removal of this domain provides a Hog1 protein that is partially independent of MAP2K, namely, partially rescues osmostress sensitivity of pbs2Δ cells. We further mapped a short domain (7 amino acid residues long) that is critical for induction of autophosphorylation. Its removal abolishes autophosphorylation, but maintains Pbs2-mediated phosphorylation. This 7 amino acids stretch is conserved in the human p38α. Similar to the case of Hog1, it’s removal from p38α abolishes p38α’s autophosphorylation capability, but maintains, although reduces, its activation by MKK6. This study joins a few recent reports to suggest that, like many protein kinases, MAPKs are also regulated via induced autoactivation. PMID:22984552

Effects of Chilling and Partial Freezing on Rigor Mortis Changes of Bighead Carp (Aristichthys nobilis) Fillets: Cathepsin Activity, Protein Degradation and Microstructure of Myofibrils.

PubMed

Lu, Han; Liu, Xiaochang; Zhang, Yuemei; Wang, Hang; Luo, Yongkang

2015-12-01

To investigate the effects of chilling and partial freezing on rigor mortis changes in bighead carp (Aristichthys nobilis), pH, cathepsin B, cathepsin B+L activities, SDS-PAGE of sarcoplasmic and myofibrillar proteins, texture, and changes in microstructure of fillets at 4 °C and -3 °C were determined at 0, 2, 4, 8, 12, 24, 48, and 72 h after slaughter. The results indicated that pH of fillets (6.50 to 6.80) was appropriate for cathepsin function during the rigor mortis. For fillets that were chilled and partially frozen, the cathepsin activity in lysosome increased consistently during the first 12 h, followed by a decrease from the 12 to 24 h, which paralleled an increase in activity in heavy mitochondria, myofibrils and sarcoplasm. There was no significant difference in cathepsin activity in lysosomes between fillets at 4 °C and -3 °C (P > 0.05). Partially frozen fillets had greater cathepsin activity in heavy mitochondria than chilled samples from the 48 to 72 h. In addition, partially frozen fillets showed higher cathepsin activity in sarcoplasm and lower cathepsin activity in myofibrils compared with chilled fillets. Correspondingly, we observed degradation of α-actinin (105 kDa) by cathepsin L in chilled fillets and degradation of creatine kinase (41 kDa) by cathepsin B in partially frozen fillets during the rigor mortis. The decline of hardness for both fillets might be attributed to the accumulation of cathepsin in myofibrils from the 8 to 24 h. The lower cathepsin activity in myofibrils for fillets that were partially frozen might induce a more intact cytoskeletal structure than fillets that were chilled. © 2015 Institute of Food Technologists®

By activating Fas/ceramide synthase 6/p38 kinase in lipid rafts, Stichoposide D inhibits growth of leukemia xenografts

PubMed Central

Yun, Seong-Hoon; Park, Eun-Seon; Shin, Sung-Won; Ju, Mi-Ha; Han, Jin-Yeong; Jeong, Jin-Sook; Kim, Sung-Hyun; Stonik, Valentin A.; Kwak, Jong-Young; Park, Joo-In

2015-01-01

Stichoposide D (STD) is a marine triterpene glycoside isolated from sea cucumbers. We examined the molecular mechanisms underlying the antitumor activity of STD in human leukemia cells. The role of Fas (CD95), ceramide synthase 6 (CerS6) and p38 kinase during STD-induced apoptosis was examined in human leukemia cells. In addition, the antitumor effects of STD in K562 and HL-60 leukemia xenograft models were investigated. We found that STD induces Fas translocation to lipid rafts, and thus mediates cell apoptosis. We also observed the activation of CerS6 and p38 kinase during STD-induced apoptosis. The use of methyl-β-cyclodextrin and nystatin to disrupt lipid rafts prevents the clustering of Fas and the activation of CerS6 and p38 kinase, and also inhibits STD-induced apoptosis. Specific inhibition by Fas, CerS6, and p38 kinase siRNA transfection partially blocked STD-induced apoptosis. In addition, STD has antitumor activity through the activation of CerS6 and p38 kinase without displaying any toxicity in HL-60 and K562 xenograft models. We observed that the anti-tumor effect of STD is partially prevented in CerS6 shRNA-silenced xenograft models. We first report that Fas/CerS6/p38 kinase activation in lipid rafts by STD is involved in its anti-leukemic activity. We also established that STD is able to enhance the chemosensitivity of K562 cells to etoposide or Ara-C. These data suggest that STD may be used alone or in combination with other chemotherapeutic agents to treat leukemia. PMID:26318294

Passive stretch reduces calpain activity through nitric oxide pathway in unloaded soleus muscles.

PubMed

Xu, Peng-Tao; Li, Quan; Sheng, Juan-Juan; Chang, Hui; Song, Zhen; Yu, Zhi-Bin

2012-08-01

Unloading in spaceflight or long-term bed rest induces to pronounced atrophy of anti-gravity skeletal muscles. Passive stretch partially resists unloading-induced atrophy of skeletal muscle, but the mechanism remains elusive. The aims of this study were to investigate the hypotheses that stretch tension might increase protein level of neuronal nitric oxide synthase (nNOS) in unloaded skeletal muscle, and then nNOS-derived NO alleviated atrophy of skeletal muscle by inhibiting calpain activity. The tail-suspended rats were used to unload rat hindlimbs for 2 weeks, at the same time, left soleus muscle was stretched by applying a plaster cast to fix the ankle at 35° dorsiflexion. Stretch partially resisted atrophy and inhibited the decreased protein level and activity of nNOS in unloaded soleus muscles. Unloading increased frequency of calcium sparks and elevated intracellular resting and caffeine-induced Ca(2+) concentration ([Ca(2+)]i) in unloaded soleus muscle fibers. Stretch reduced frequency of calcium sparks and restored intracellular resting and caffeine-induced Ca(2+) concentration to control levels in unloaded soleus muscle fibers. The increased protein level and activity of calpain as well as the higher degradation of desmin induced by unloading were inhibited by stretch in soleus muscles. In conclusion, these results suggest that stretch can preserve the stability of sarcoplasmic reticulum Ca(2+) release channels which prevents the elevated [Ca(2+)]i by means of keeping nNOS activity, and then the enhanced protein level and activity of calpain return to control levels in unloaded soleus muscles. Therefore, stretch can resist in part atrophy of unloaded soleus muscles.

Novel Podophyllotoxin Derivatives as Partial PPARγ Agonists and their Effects on Insulin Resistance and Type 2 Diabetes.

PubMed

Zhang, Xiangming; Liu, Huijuan; Sun, Bo; Sun, Yan; Zhong, Weilong; Liu, Yanrong; Chen, Shuang; Ling, Honglei; Zhou, Lei; Jing, Xiangyan; Qin, Yuan; Xiao, Ting; Sun, Tao; Zhou, Honggang; Yang, Cheng

2016-11-17

Peroxisome proliferator-activated receptor γ (PPARγ) is recognized as a key regulator of insulin resistance. In this study, we searched for novel PPARγ agonists in a library of structurally diverse organic compounds and determined that podophyllotoxin exhibits partial agonist activity toward PPARγ. Eight novel podophyllotoxin-like derivatives were synthesized and assayed for toxicity and functional activity toward PPARγ to reduce the possible systemic toxic effects of podophyllotoxin and to maintain partial agonist activity toward PPARγ. Cell-based transactivation assays showed that compounds (E)-3-(hydroxy(3,4,5-trimethoxyphenyl)methyl)-4-(4(trifluoromethyl)styryl)dihydrofuran-2(3H)-one (3a) and (E)-4-(3-acetylstyryl)-3-(hydroxyl (3,4,5-trimethoxyphenyl)methyl)dihydrofuran-2(3H)-one (3f) exhibited partial agonist activity. An experiment using human hepatocarcinoma cells (HepG2) that were induced to become an insulin-resistant model showed that compounds 3a and 3f improved insulin sensitivity and glucose consumption. In addition, compounds 3a and 3f significantly improved hyperglycemia and insulin resistance in high-fat diet-fed streptozotocin (HFD-STZ)-induced type 2 diabetic rats at a dose of 15 mg/kg/day administered orally for 45 days, without significant weight gain. Cell toxicity testing also showed that compounds 3a and 3f exhibited weaker toxicity than pioglitazone. These findings suggested that compounds 3a and 3f improved insulin resistance in vivo and in vitro and that the compounds exhibited potential for the treatment of type 2 diabetes mellitus.

Bauhinia forficata prevents vacuous chewing movements induced by haloperidol in rats and has antioxidant potential in vitro.

PubMed

Peroza, Luis Ricardo; Busanello, Alcindo; Leal, Caroline Queiroz; Röpke, Jivago; Boligon, Aline Augusti; Meinerz, Daiane; Libardoni, Milena; Athayde, Margareth Linde; Fachinetto, Roselei

2013-04-01

Classical antipsychotics can produce motor disturbances like tardive dyskinesia in humans and orofacial dyskinesia in rodents. These motor side effects have been associated with oxidative stress production in specific brain areas. Thus, some studies have proposed the use of natural compounds with antioxidant properties against involuntary movements induced by antipsychotics. Here, we examined the possible antioxidant activity of Bauhinia forficata (B. forficata), a plant used in folk medicine as a hypoglycemic, on brain lipid peroxidation induced by different pro-oxidants. B. forficata prevented the formation of lipid peroxidation induced by both pro-oxidants tested. However, it was effective against lipid peroxidation induced by sodium nitroprusside (IC50 = 12.08 μg/mL) and Fe(2+)/EDTA (IC50 = 41.19 μg/mL). Moreover, the effects of B. forficata were analyzed on an animal model of orofacial dyskinesia induced by long-term treatment with haloperidol, where rats received haloperidol each 28 days (38 mg/kg) and/or B. forficata decoction daily (2.5 g/L) for 16 weeks. Vacuous chewing movements (VCMs), locomotor and exploratory activities were evaluated. Haloperidol treatment induced VCMs, and co-treatment with B. forficata partially prevented this effect. Haloperidol reduced the locomotor and exploratory activities of animals in the open field test, which was not modified by B. forficata treatment. Our present data showed that B. forficata has antioxidant potential and partially protects against VCMs induced by haloperidol in rats. Taken together, our data suggest the protection by natural compounds against VCMs induced by haloperidol in rats.

Oxygen availability and spreading depolarizations provide complementary prognostic information in neuromonitoring of aneurysmal subarachnoid hemorrhage patients.

PubMed

Winkler, Maren Kl; Dengler, Nora; Hecht, Nils; Hartings, Jed A; Kang, Eun J; Major, Sebastian; Martus, Peter; Vajkoczy, Peter; Woitzik, Johannes; Dreier, Jens P

2017-05-01

Multimodal neuromonitoring in neurocritical care increasingly includes electrocorticography to measure epileptic events and spreading depolarizations. Spreading depolarization causes spreading depression of activity (=isoelectricity) in electrically active tissue. If the depression is long-lasting, further spreading depolarizations occur in still isoelectric tissue where no activity can be suppressed. Such spreading depolarizations are termed isoelectric and are assumed to indicate energy compromise. However, experimental and clinical recordings suggest that long-lasting spreading depolarization-induced depression and isoelectric spreading depolarizations are often recorded outside of the actual ischemic zones, allowing the remote diagnosis of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. Here, we analyzed simultaneous electrocorticography and tissue partial pressure of oxygen recording in 33 aneurysmal subarachnoid hemorrhage patients. Multiple regression showed that both peak total depression duration per recording day and mean baseline tissue partial pressure of oxygen were independent predictors of outcome. Moreover, tissue partial pressure of oxygen preceding spreading depolarization was similar and differences in tissue partial pressure of oxygen responses to spreading depolarization were only subtle between isoelectric spreading depolarizations and spreading depressions. This further supports that, similar to clustering of spreading depolarizations, long spreading depolarization-induced periods of isoelectricity are useful to detect energy compromise remotely, which is valuable because the exact location of future developing pathology is unknown at the time when the neurosurgeon implants recording devices.

Oxygen partial pressure modulates 67-kDa laminin receptor expression, leading to altered activity of the green tea polyphenol, EGCG.

PubMed

Tsukamoto, Shuntaro; Yamashita, Shuya; Kim, Yoon Hee; Kumazoe, Motofumi; Huang, Yuhui; Yamada, Koji; Tachibana, Hirofumi

2012-09-21

(-)-Epigallocatechin-3-O-gallate (EGCG) exhibits anti-tumor activity mediated via the 67-kDa laminin receptor (67LR). In this study, we found that 67LR protein levels are reduced by exposure to low O(2) levels (5%), without affecting the expression of HIF-1α. We also found that EGCG-induced anti-cancer activity is abrogated under low O(2) levels (5%) in various cancer cells. Notably, treatment with the proteasome inhibitor, prevented down-regulation of 67LR and restored sensitivity to EGCG under 5% O(2). In summary, 67LR expression is highly sensitive to O(2) partial pressure, and the activity of EGCG can be regulated in cancer cells by O(2) partial pressure. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

The p53-reactivating small molecule RITA induces senescence in head and neck cancer cells.

PubMed

Chuang, Hui-Ching; Yang, Liang Peng; Fitzgerald, Alison L; Osman, Abdullah; Woo, Sang Hyeok; Myers, Jeffrey N; Skinner, Heath D

2014-01-01

TP53 is the most commonly mutated gene in head and neck cancer (HNSCC), with mutations being associated with resistance to conventional therapy. Restoring normal p53 function has previously been investigated via the use of RITA (reactivation of p53 and induction of tumor cell apoptosis), a small molecule that induces a conformational change in p53, leading to activation of its downstream targets. In the current study we found that RITA indeed exerts significant effects in HNSCC cells. However, in this model, we found that a significant outcome of RITA treatment was accelerated senescence. RITA-induced senescence in a variety of p53 backgrounds, including p53 null cells. Also, inhibition of p53 expression did not appear to significantly inhibit RITA-induced senescence. Thus, this phenomenon appears to be partially p53-independent. Additionally, RITA-induced senescence appears to be partially mediated by activation of the DNA damage response and SIRT1 (Silent information regulator T1) inhibition, with a synergistic effect seen by combining either ionizing radiation or SIRT1 inhibition with RITA treatment. These data point toward a novel mechanism of RITA function as well as hint to its possible therapeutic benefit in HNSCC.

Partial hepatic resistance to IL-6-induced inflammation develops in type 2 diabetic mice, while the anti-inflammatory effect of AMPK is maintained.

PubMed

Cansby, Emmelie; Nerstedt, Annika; Amrutkar, Manoj; Durán, Esther Nuñez; Smith, Ulf; Mahlapuu, Margit

2014-08-05

Interleukin-6 (IL-6) induces hepatic inflammation and insulin resistance, and therapeutic strategies to counteract the IL-6 action in liver are of high interest. In this study, we demonstrate that acute treatment with AMP-activated protein kinase (AMPK) agonists AICAR and metformin efficiently repressed IL-6-induced hepatic proinflammatory gene expression and activation of STAT3 in a mouse model of diet-induced type 2 diabetes, bringing it back to basal nonstimulated level. Surprisingly, the inflammatory response in liver induced by IL-6 administration in vivo was markedly blunted in the mice fed a high-fat diet, compared to lean chow-fed controls, while this difference was not replicated in vitro in primary hepatocytes derived from these two groups of mice. In summary, our work reveals that partial hepatic IL-6 resistance develops in the mouse model of type 2 diabetes, while the anti-inflammatory action of AMPK is maintained. Systemic factors, rather than differences in intracellular IL-6 receptor signaling, are likely mediating the relative impairment in IL-6 effect. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Activity-dependent release of tissue plasminogen activator from the dendritic spines of hippocampal neurons revealed by live-cell imaging.

PubMed

Lochner, Janis E; Honigman, Leah S; Grant, Wilmon F; Gessford, Sarah K; Hansen, Alexis B; Silverman, Michael A; Scalettar, Bethe A

2006-05-01

Tissue plasminogen activator (tPA) has been implicated in a variety of important cellular functions, including learning-related synaptic plasticity and potentiating N-methyl-D-aspartate (NMDA) receptor-dependent signaling. These findings suggest that tPA may localize to, and undergo activity-dependent secretion from, synapses; however, conclusive data supporting these hypotheses have remained elusive. To elucidate these issues, we studied the distribution, dynamics, and depolarization-induced secretion of tPA in hippocampal neurons, using fluorescent chimeras of tPA. We found that tPA resides in dense-core granules (DCGs) that traffic to postsynaptic dendritic spines and that can remain in spines for extended periods. We also found that depolarization induced by high potassium levels elicits a slow, partial exocytotic release of tPA from DCGs in spines that is dependent on extracellular Ca(+2) concentrations. This slow, partial release demonstrates that exocytosis occurs via a mechanism, such as fuse-pinch-linger, that allows partial release and reuse of DCG cargo and suggests a mechanism that hippocampal neurons may rely upon to avoid depleting tPA at active synapses. Our results also demonstrate release of tPA at a site that facilitates interaction with NMDA-type glutamate receptors, and they provide direct confirmation of fundamental hypotheses about tPA localization and release that bear on its neuromodulatory functions, for example, in learning and memory.

Mechanism of salt-induced activity enhancement of a marine-derived laccase, Lac15.

PubMed

Li, Jie; Xie, Yanan; Wang, Rui; Fang, Zemin; Fang, Wei; Zhang, Xuecheng; Xiao, Yazhong

2018-04-01

Laccase (benzenediol: oxygen oxidoreductases, EC1.10.3.2) is a multi-copper oxidase capable of oxidizing a variety of phenolic and other aromatic organic compounds. The catalytic power of laccase makes it an attractive candidate for potential applications in many areas of industry including biodegradation of organic pollutants and synthesis of novel drugs. Most laccases are vulnerable to high salt and have limited applications. However, some laccases are not only tolerant to but also activated by certain concentrations of salt and thus have great application potential. The mechanisms of salt-induced activity enhancement of laccases are unclear as yet. In this study, we used dynamic light scattering, size exclusion chromatography, analytical ultracentrifugation, intrinsic fluorescence emission, circular dichroism, ultraviolet-visible light absorption, and an enzymatic assay to investigate the potential correlation between the structure and activity of the marine-derived laccase, Lac15, whose activity is promoted by low concentrations of NaCl. The results showed that low concentrations of NaCl exert little influence on the protein structure, which was partially folded in the absence of the salt; moreover, the partially folded rather than the fully folded state seemed to be favorable for enzyme activity, and this partially folded state was distinctive from the so-called 'molten globule' occasionally observed in active enzymes. More data indicated that salt might promote laccase activity through mechanisms involving perturbation of specific local sites rather than a change in global structure. Potential binding sites for chloride ions and their roles in enzyme activity promotion are proposed.

Leaf Treatments with a Protein-Based Resistance Inducer Partially Modify Phyllosphere Microbial Communities of Grapevine

PubMed Central

Cappelletti, Martina; Perazzolli, Michele; Antonielli, Livio; Nesler, Andrea; Torboli, Esmeralda; Bianchedi, Pier L.; Pindo, Massimo; Puopolo, Gerardo; Pertot, Ilaria

2016-01-01

Protein derivatives and carbohydrates can stimulate plant growth, increase stress tolerance, and activate plant defense mechanisms. However, these molecules can also act as a nutritional substrate for microbial communities living on the plant phyllosphere and possibly affect their biocontrol activity against pathogens. We investigated the mechanisms of action of a protein derivative (nutrient broth, NB) against grapevine downy mildew, specifically focusing on the effects of foliar treatments on plant defense stimulation and on the composition and biocontrol features of the phyllosphere microbial populations. NB reduced downy mildew symptoms and induced the expression of defense-related genes in greenhouse- and in vitro-grown plants, indicating the activation of grapevine resistance mechanisms. Furthermore, NB increased the number of culturable phyllosphere bacteria and altered the composition of bacterial and fungal populations on leaves of greenhouse-grown plants. Although, NB-induced changes on microbial populations were affected by the structure of indigenous communities originally residing on grapevine leaves, degrees of disease reduction and defense gene modulation were consistent among the experiments. Thus, modifications in the structure of phyllosphere populations caused by NB application could partially contribute to downy mildew control by competition for space or other biocontrol strategies. Particularly, changes in the abundance of phyllosphere microorganisms may provide a contribution to resistance induction, partially affecting the hormone-mediated signaling pathways involved. Modifying phyllosphere populations by increasing natural biocontrol agents with the application of selected nutritional factors can open new opportunities in terms of sustainable plant protection strategies. PMID:27486468

Dopamine Attenuates Ketamine-Induced Neuronal Apoptosis in the Developing Rat Retina Independent of Early Synchronized Spontaneous Network Activity.

PubMed

Dong, Jing; Gao, Lingqi; Han, Junde; Zhang, Junjie; Zheng, Jijian

2017-07-01

Deprivation of spontaneous rhythmic electrical activity in early development by anesthesia administration, among other interventions, induces neuronal apoptosis. However, it is unclear whether enhancement of neuronal electrical activity attenuates neuronal apoptosis in either normal development or after anesthesia exposure. The present study investigated the effects of dopamine, an enhancer of spontaneous rhythmic electrical activity, on ketamine-induced neuronal apoptosis in the developing rat retina. TUNEL and immunohistochemical assays indicated that ketamine time- and dose-dependently aggravated physiological and ketamine-induced apoptosis and inhibited early-synchronized spontaneous network activity. Dopamine administration reversed ketamine-induced neuronal apoptosis, but did not reverse the inhibitory effects of ketamine on early synchronized spontaneous network activity despite enhancing it in controls. Blockade of D1, D2, and A2A receptors and inhibition of cAMP/PKA signaling partially antagonized the protective effect of dopamine against ketamine-induced apoptosis. Together, these data indicate that dopamine attenuates ketamine-induced neuronal apoptosis in the developing rat retina by activating the D1, D2, and A2A receptors, and upregulating cAMP/PKA signaling, rather than through modulation of early synchronized spontaneous network activity.

Activated Rho Kinase Mediates Diabetes-Induced Elevation of Vascular Arginase Activation and Contributes to Impaired Corpora Cavernosa Relaxation: Possible Involvement of p38 MAPK Activation

PubMed Central

Nunes, Kenia P.; Yao, Lin; Liao, James K.; Webb, R. Clinton; Caldwell, Ruth B.; Caldwell, R. William

2013-01-01

Introduction Activated RhoA/Rho kinase (ROCK) has been implicated in diabetes-induced erectile dysfunction. Earlier studies have demonstrated involvement of ROCK pathway in the activation of arginase in endothelial cells. However, signaling pathways activated by ROCK in the penis remain unclear. Aim We tested whether ROCK and p38 MAPK are involved in the elevation of arginase activity and subsequent impairment of corpora cavernosal (CC) relaxation in diabetes. Methods Eight weeks after streptozotocin-induced diabetes, vascular functional studies, arginase activity assay, and protein expression of RhoA, ROCK, phospho-p38 MAPK, p38 MAPK, phospho-MYPT-1Thr850, MYPT-1 and arginase levels were assessed in CC tissues from nondiabetic wild type (WT), diabetic (D) WT (WT + D), partial ROCK 2+/− knockout (KO), and ROCK 2+/− KO + D mice. Main Outcome Measures The expression of RhoA, ROCK 1 and 2, phosphorylation of MYPT-1Thr850 and p38 MAPK, arginase activity/expression, endothelial- and nitrergic-dependent relaxation of CC was assayed. Results Diabetes significantly reduced maximum relaxation (Emax) to both endothelium-dependent acetylcholine (WT + D: Emax; 61 ± 4% vs. WT: Emax; 75 ± 2%) and nitrergic nerve stimulation. These effects were associated with increased expression of active RhoA, ROCK 2, phospho-MYPT-1Thr850, phospho-p38 MAPK, arginase II, and activity of corporal arginase (1.6-fold) in WT diabetic CC. However, this impairment in CC of WT + D mice was absent in heterozygous ROCK 2+/− KO + D mice for acetylcholine (Emax: 80 ± 5%) and attenuated for nitrergic nerve-induced relaxation. CC of ROCK 2+/− KO + D mice showed much less ROCK activity, did not exhibit p38 MAPK activation, and had reduced arginase activity and arginase II expression. These findings indicate that ROCK 2 mediates diabetes-induced elevation of arginase activity. Additionally, pretreatment of WT diabetic CC with inhibitors of arginase (ABH) or p38 MAPK (SB203580) partially prevented impairment of ACh- and nitrergic nerve-induced relaxation and elevation of arginase activity. Conclusion ROCK 2, p38 MAPK and arginase play key roles in diabetes-induced impairment of CC relaxation. PMID:23566117

EGF receptor tyrosine kinase inhibitors diminish transforming growth factor-alpha-induced pulmonary fibrosis.

PubMed

Hardie, William D; Davidson, Cynthia; Ikegami, Machiko; Leikauf, George D; Le Cras, Timothy D; Prestridge, Adrienne; Whitsett, Jeffrey A; Korfhagen, Thomas R

2008-06-01

Transforming growth factor-alpha (TGF-alpha) is a ligand for the EGF receptor (EGFR). EGFR activation is associated with fibroproliferative processes in human lung disease and animal models of pulmonary fibrosis. We determined the effects of EGFR tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva) on the development and progression of TGF-alpha-induced pulmonary fibrosis. Using a doxycycline-regulatable transgenic mouse model of lung-specific TGF-alpha expression, we determined effects of treatment with gefitinib and erlotinib on changes in lung histology, total lung collagen, pulmonary mechanics, pulmonary hypertension, and expression of genes associated with synthesis of ECM and vascular remodeling. Induction in the lung of TGF-alpha caused progressive pulmonary fibrosis over an 8-wk period. Daily administration of gefitinib or erlotinib prevented development of fibrosis, reduced accumulation of total lung collagen, prevented weight loss, and prevented changes in pulmonary mechanics. Treatment of mice with gefitinib 4 wk after the induction of TGF-alpha prevented further increases in and partially reversed total collagen levels and changes in pulmonary mechanics and pulmonary hypertension. Increases in expression of genes associated with synthesis of ECM as well as decreases of genes associated with vascular remodeling were also prevented or partially reversed. Administration of gefitinib or erlotinib did not cause interstitial fibrosis or increases in lavage cell counts. Administration of small molecule EGFR tyrosine kinase inhibitors prevented further increases in and partially reversed pulmonary fibrosis induced directly by EGFR activation without inducing inflammatory cell influx or additional lung injury.

Identification of PPARgamma Partial Agonists of Natural Origin (I): Development of a Virtual Screening Procedure and In Vitro Validation

PubMed Central

Guasch, Laura; Sala, Esther; Castell-Auví, Anna; Cedó, Lidia; Liedl, Klaus R.; Wolber, Gerhard; Muehlbacher, Markus; Mulero, Miquel; Pinent, Montserrat; Ardévol, Anna; Valls, Cristina; Pujadas, Gerard; Garcia-Vallvé, Santiago

2012-01-01

Background Although there are successful examples of the discovery of new PPARγ agonists, it has recently been of great interest to identify new PPARγ partial agonists that do not present the adverse side effects caused by PPARγ full agonists. Consequently, the goal of this work was to design, apply and validate a virtual screening workflow to identify novel PPARγ partial agonists among natural products. Methodology/Principal Findings We have developed a virtual screening procedure based on structure-based pharmacophore construction, protein-ligand docking and electrostatic/shape similarity to discover novel scaffolds of PPARγ partial agonists. From an initial set of 89,165 natural products and natural product derivatives, 135 compounds were identified as potential PPARγ partial agonists with good ADME properties. Ten compounds that represent ten new chemical scaffolds for PPARγ partial agonists were selected for in vitro biological testing, but two of them were not assayed due to solubility problems. Five out of the remaining eight compounds were confirmed as PPARγ partial agonists: they bind to PPARγ, do not or only moderately stimulate the transactivation activity of PPARγ, do not induce adipogenesis of preadipocyte cells and stimulate the insulin-induced glucose uptake of adipocytes. Conclusions/Significance We have demonstrated that our virtual screening protocol was successful in identifying novel scaffolds for PPARγ partial agonists. PMID:23226391

Partial exposure of frog heart to high-potassium solution: an easily reproducible model mimicking ST segment changes.

PubMed

Kon, Nobuaki; Abe, Nozomu; Miyazaki, Masahiro; Mushiake, Hajime; Kazama, Itsuro

2018-04-18

By simply inducing burn injuries on the bullfrog heart, we previously reported a simple model of abnormal ST segment changes observed in human ischemic heart disease. In the present study, instead of inducing burn injuries, we partially exposed the surface of the frog heart to high-potassium (K + ) solution to create a concentration gradient of the extracellular K + within the myocardium. Dual recordings of ECG and the cardiac action potential demonstrated significant elevation of the ST segment and the resting membrane potential, indicating its usefulness as a simple model of heart injury. Additionally, from our results, Na + /K + -ATPase activity was thought to be primarily responsible for generating the K + concentration gradient and inducing the ST segment changes in ECG.

Gemcitabine sensitizes lung cancer cells to Fas/FasL system-mediated killing

PubMed Central

Siena, Liboria; Pace, Elisabetta; Ferraro, Maria; Di Sano, Caterina; Melis, Mario; Profita, Mirella; Spatafora, Mario; Gjomarkaj, Mark

2014-01-01

Gemcitabine is a chemotherapy agent commonly used in the treatment of non-small cell lung cancer (NSCLC) that has been demonstrated to induce apoptosis in NSCLC cells by increasing functionally active Fas expression. The aim of this study was to evaluate the Fas/Fas ligand (FasL) system involvement in gemcitabine-induced lung cancer cell killing. NSCLC H292 cells were cultured in the presence or absence of gemcitabine. FasL mRNA and protein were evaluated by real-time PCR, and by Western blot and flow cytometry, respectively. Apoptosis of FasL-expressing cells was evaluated by flow cytometry, and caspase-8 and caspase-3 activation by Western blot and a colorimetric assay. Cytotoxicity of lymphokine-activated killer (LAK) cells and malignant pleural fluid lymphocytes against H292 cells was analysed in the presence or absence of the neutralizing anti-Fas ZB4 antibody, by flow cytometry. Gemcitabine increased FasL mRNA and total protein expression, the percentage of H292 cells bearing membrane-bound FasL (mFasL) and of mFasL-positive apoptotic H292 cells, as well as caspase-8 and caspase-3 cleavage. Moreover, gemcitabine increased CH11-induced caspase-8 and caspase-3 cleavage and proteolytic activity. Cytotoxicity of LAK cells and pleural fluid lymphocytes was increased against gemcitabine-treated H292 cells and was partially inhibited by ZB4 antibody. These results demonstrate that gemcitabine: (i) induces up-regulation of FasL in lung cancer cells triggering cell apoptosis via an autocrine/paracrine loop; (ii) induces a Fas-dependent apoptosis mediated by caspase-8 and caspase-3 activation; (iii) enhances the sensitivity of lung cancer cells to cytotoxic activity of LAK cells and malignant pleural fluid lymphocytes, partially via Fas/FasL pathway. Our data strongly suggest an active involvement of the Fas/FasL system in gemcitabine-induced lung cancer cell killing. PMID:24128051

Leptin activates STAT and ERK2 pathways and induces gastric cancer cell proliferation

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

Pai, Rama; Lin Cal; Tran, Teresa

2005-06-17

Although leptin is known to induce proliferative response in gastric cancer cells, the mechanism(s) underlying this action remains poorly understood. Here, we provide evidence that leptin-induced gastric cancer cell proliferation involves activation of STAT and ERK2 signaling pathways. Leptin-induced STAT3 phosphorylation is independent of ERK2 activation. Leptin increases SHP2 phosphorylation and enhances binding of Grb2 to SHP2. Inhibition of SHP2 expression with siRNA but not SHP2 phosphatase activity abolished leptin-induced ERK2 activation. While JAK inhibition with AG490 significantly reduced leptin-induced ERK2, STAT3 phosphorylation, and cell proliferation, SHP2 inhibition only partially reduced cancer cell proliferation. Immunostaining of gastric cancer tissues displayedmore » local overexpression of leptin and its receptor indicating that leptin might be produced and act locally in a paracrine or autocrine manner. These findings indicate that leptin promotes cancer growth by activating multiple signaling pathways and therefore blocking its action at the receptor level could be a rational therapeutic strategy.« less

Hepatic steatosis development with four weeks of physical inactivity in previously active, hyperphagic OLETF rats.

PubMed

Linden, Melissa A; Meers, Grace M; Ruebel, Meghan L; Jenkins, Nathan T; Booth, Frank W; Laughlin, M Harold; Ibdah, Jamal A; Thyfault, John P; Rector, R Scott

2013-05-01

Physical activity-induced prevention of hepatic steatosis is maintained during short-term (7-day) transitions to an inactive state; however, whether these protective effects are present under a longer duration of physical inactivity is largely unknown. Here, we sought to determine whether previous physical activity had protective effects on hepatic steatosis and metabolic health following 4 wk of physical inactivity. Four-week old, hyperphagic, male Otsuka Long-Evans Tokushima fatty (OLETF) rats were randomly assigned to either a sedentary group for 16 wk (OLETF-SED), given access to running wheels for 16 wk with wheels locked 5 h (OLETF-WL5hr) or given access to running wheels for 12 wk with wheels locked 4 wk (OLETF-WL4wk) prior to death. Four weeks of physical inactivity caused hepatic steatosis development, but liver triglycerides remained 60% lower than OLETF-SED (P < 0.01), and this was associated with only a partial loss in activity-induced improvements in body composition, serum lipids, and glycemic control. Total hepatic mitochondrial palmitate oxidation, citrate synthase, and β-HAD activity returned to SED levels following 4 wk of inactivity, whereas markers of fatty acid uptake and lipogenesis remained relatively suppressed following 4 wk of inactivity. In addition, 4 wk of inactivity caused a complete loss of activity-induced increases in serum IL-6 and reductions in regulated upon activation, normal T-cell expressed, and secreted (RANTES), and a partial loss in reductions in leptin, monocyte chemoattractant protein-1, and TNF-α. In conclusion, 4 wk of physical inactivity does not result in a complete loss in physical activity-induced benefits but does cause deterioration in the liver phenotype and overall metabolic health in hyperphagic OLETF rats.

Cytidine deamination induced HIV-1 drug resistance

PubMed Central

Mulder, Lubbertus C. F.; Harari, Ariana; Simon, Viviana

2008-01-01

The HIV-1 Vif protein is essential for overcoming the antiviral activity of DNA-editing apolipoprotein B mRNA editing enzyme, catalytic polypeptide 3 (APOBEC3) cytidine deaminases. We show that naturally occurring HIV-1 Vif point mutants with suboptimal anti-APOBEC3G activity induce the appearance of proviruses with lamivudine (3TC) drug resistance-associated mutations before any drug exposure. These mutations, ensuing from cytidine deamination events, were detected in >40% of proviruses with partially defective Vif mutants. Transfer of drug resistance from hypermutated proviruses via recombination allowed for 3TC escape under culture conditions prohibitive for any WT viral growth. These results demonstrate that defective hypermutated genomes can shape the phenotype of the circulating viral population. Partially active Vif alleles resulting in incomplete neutralization of cytoplasmic APOBEC3 molecules are directly responsible for the generation of a highly diverse, yet G-to-A biased, proviral reservoir, which can be exploited by HIV-1 to generate viable and drug-resistant progenies. PMID:18391217

Active-State Model of a Dopamine D2 Receptor - Gαi Complex Stabilized by Aripiprazole-Type Partial Agonists

PubMed Central

Kling, Ralf C.; Tschammer, Nuska; Lanig, Harald; Clark, Timothy; Gmeiner, Peter

2014-01-01

Partial agonists exhibit a submaximal capacity to enhance the coupling of one receptor to an intracellular binding partner. Although a multitude of studies have reported different ligand-specific conformations for a given receptor, little is known about the mechanism by which different receptor conformations are connected to the capacity to activate the coupling to G-proteins. We have now performed molecular-dynamics simulations employing our recently described active-state homology model of the dopamine D2 receptor-Gαi protein-complex coupled to the partial agonists aripiprazole and FAUC350, in order to understand the structural determinants of partial agonism better. We have compared our findings with our model of the D2R-Gαi-complex in the presence of the full agonist dopamine. The two partial agonists are capable of inducing different conformations of important structural motifs, including the extracellular loop regions, the binding pocket and, in particular, intracellular G-protein-binding domains. As G-protein-coupling to certain intracellular epitopes of the receptor is considered the key step of allosterically triggered nucleotide-exchange, it is tempting to assume that impaired coupling between the receptor and the G-protein caused by distinct ligand-specific conformations is a major determinant of partial agonist efficacy. PMID:24932547

Dimethyl sulfoxide attenuates hydrogen peroxide-induced injury in cardiomyocytes via heme oxygenase-1.

PubMed

Man, Wang; Ming, Ding; Fang, Du; Chao, Liang; Jing, Cang

2014-06-01

The antioxidant property of dimethyl sulfoxide (DMSO) was formerly attributed to its direct effects. Our former study showed that DMSO is able to induce heme oxygenase-1 (HO-1) expression in endothelial cells, which is a potent antioxidant enzyme. In this study, we hypothesized that the antioxidant effects of DMSO in cardiomyocytes are mediated or partially mediated by increased HO-1 expression. Therefore, we investigated whether DMSO exerts protective effects against H2 O2 -induced oxidative damage in cardiomyocytes, and whether HO-1 is involved in DMSO-imparted protective effects, and we also explore the underlying mechanism of DMSO-induced HO-1 expression. Our study demonstrated that DMSO pretreatment showed a cytoprotective effect against H2 O2 -induced oxidative damage (impaired cell viability, increased apopototic cells rate and caspase-3 level, and increased release of LDH and CK) and this process is partially mediated by HO-1 upregulation. Furthermore, our data showed that the activation of p38 MAPK and Nrf2 translocation are involved in the HO-1 upregulation induced by DMSO. This study reports for the first time that the cytoprotective effect of DMSO in cardiomyocytes is partially mediated by HO-1, which may further explain the mechanisms by which DMSO exerts cardioprotection on H2 O2 injury. J. Cell. Biochem. 115: 1159-1165, 2014. © 2013 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Isobolographic analysis of the opioid-opioid interactions in a tonic and a phasic mouse model of induced nociceptive pain.

PubMed

Miranda, Hugo F; Noriega, Viviana; Zanetta, Pilar; Prieto, Juan Carlos; Prieto-Rayo, Juan Carlos; Aranda, Nicolás; Sierralta, Fernando

2014-07-15

Opioids have been used for the management of pain and coadministration of two opioids may induce synergism. In a model of tonic pain, the acetic acid writhing test and in a phasic model, the hot plate, the antinociceptive interaction between fentanyl, methadone, morphine, and tramadol was evaluated. The potency of opioids in the writhing test compared to the hot plate assay was from 2.5 (fentanyl) to 15.5 (morphine) times, respectively. The ED50 was used in a fixed ratio for each of the six pairs of opioid combinations, which, resulted in a synergistic antinociception except for methadone/tramadol and fentanyl/tramadol which were additive, in the hot plate. The opioid antagonists naltrexone, naltrindole and nor-binaltorphimine, suggests that the synergism of morphine combinations are due to the activation of MOR subtypes with partially contribution of DOR and KOR, however fentanyl and methadone combinations are partially due to the activation of MOR and DOR subtypes and KOR lack of participation. The antinociceptive effects of tramadol combinations, are partially due to the activation of MOR, DOR and KOR opioid subtypes. These results suggets that effectiveness and magnitude of the interactions between opioids are dependent on pain stimulus intensity.

Isobolographic analysis of the opioid-opioid interactions in a tonic and a phasic mouse model of induced nociceptive pain

PubMed Central

2014-01-01

Background Opioids have been used for the management of pain and coadministration of two opioids may induce synergism. In a model of tonic pain, the acetic acid writhing test and in a phasic model, the hot plate, the antinociceptive interaction between fentanyl, methadone, morphine, and tramadol was evaluated. Results The potency of opioids in the writhing test compared to the hot plate assay was from 2.5 (fentanyl) to 15.5 (morphine) times, respectively. The ED50 was used in a fixed ratio for each of the six pairs of opioid combinations, which, resulted in a synergistic antinociception except for methadone/tramadol and fentanyl/tramadol which were additive, in the hot plate. The opioid antagonists naltrexone, naltrindole and nor-binaltorphimine, suggests that the synergism of morphine combinations are due to the activation of MOR subtypes with partially contribution of DOR and KOR, however fentanyl and methadone combinations are partially due to the activation of MOR and DOR subtypes and KOR lack of participation. The antinociceptive effects of tramadol combinations, are partially due to the activation of MOR, DOR and KOR opioid subtypes. Conclusion These results suggets that effectiveness and magnitude of the interactions between opioids are dependent on pain stimulus intensity. PMID:25017386

The specific GTP requirement for inositol 1,4,5-trisphosphate-induced Ca2+ release from skinned vascular smooth muscle.

PubMed

Saida, K; Twort, C; van Breemen, C

1988-01-01

Exogenous GTP was required for the induction of Ca2+ release from smooth muscle SR by IP3 if endogenous GTP was depleted. NaN3 could function as a partial substitute for GTP as a cofactor for the IP3-induced Ca2+ release from the SR. In contrast to the IP3-induced Ca2+ release, caffeine-induced Ca2+ release from the SR did not require GTP. Pertussis toxin inhibited the IP3-induced Ca2+ release from the SR, whereas it had no effect on caffeine-induced Ca2+ release. These results indicate that in smooth muscle two different Ca2+ release-channels exist in the SR: (a) activated by IP3, and (b) activated by caffeine or Ca2+.

Photochemoprotective effect of a fraction of a partially purified extract of Byrsonima crassifolia leaves against UVB-induced oxidative stress in fibroblasts and hairless mice.

PubMed

de Souza, Rebeca Oliveira; de Assis Dias Alves, Geórgia; Aguillera, Ana Luiza Scarano; Rogez, Hervé; Fonseca, Maria José Vieira

2018-01-01

Ultraviolet B (UVB) irradiation increases the risk of various skin disorders, leading to inflammation and oxidative stress and thereby increasing the risk of skin photoaging and carcinogenesis. The use of photochemoprotectors such as natural products with antioxidant and anti-inflammatory properties represents a strategy for preventing UVB-induced skin damage. We investigated the photochemoprotective effect of a fraction of a partially purified extract of Byrsonima crassifolia leaves (BCF) on fibroblasts and hairless mice exposed to UVB radiation. The mixture of phenolic compounds in BCF prevented the decrease in reduced glutathione (GSH) levels in fibroblast cultures induced by UVB radiation more than some of their individual standards ((+)-catechin (CAT), epigallocatechin gallate and quercetin 3-O-β-d-glucopyranoside). Prepared gel formulations increased skin antioxidant activity, and BCF components and the CAT standard were retained in the HRS/J hairless mice epidermis 2h after application. Topical treatment with the BCF or CAT formulations (1%) significantly reduced the decrease in GSH levels and decreased myeloperoxidase activity and the secretion of pro-inflammatory cytokines IL-1β and IL-6 induced by UVB radiation (P<0.05), indicating that both BCF and CAT had anti-inflammatory effects. BCF inhibited UVB-induced metalloproteinase (MMP)-9 secretion/activity, whereas CAT had no effect on MMP-9 activity in the skin of treated animals. These results therefore suggest that BCF can be used as a photochemoprotective agent and antioxidant in the prevention/treatment of inflammation and oxidative stress of the skin induced by UVB radiation. Copyright © 2017 Elsevier B.V. All rights reserved.

Ibrutinib improves the development of acute lymphoblastic leukemia by activating endoplasmic reticulum stress-induced cell death.

PubMed

Li, Zhaohui; Wu, Jia; Sheng, Lei

2018-05-01

The current study mainly aims to evaluate the effects of ibrutinib on endoplasmic reticulum stress (ERS)-induced apoptosis in Reh cells, which may shed light on the treatment of acute lymphoblastic leukemia (ALL) among children. In line with previous studies, our data show that ibrutinib significantly suppressed Reh cell viability in a time- and dose-dependent manner. We further evaluated the role of ibrutinib on Reh cell colony formation and apoptosis. Ibrutinib inhibited clonogenic capacity and induced Reh cell apoptosis, suggesting an anti-tumor effects of ibrutinib in the progression of ALL. Further study showed that ibrutinib treatment increased ERS-related protein expression, including Bip, ATF4 and CHOP, suggesting the induction of ER-stress in Reh cells. More importantly, once ER-stress was suppressed by tauroursodeoxycholic acid (TUDCA), an ER-stress inhibitor, the upregulation of Bip, ATF4, CHOP, cleaved-caspase3 and cleaved-PARP after ibrutinib treatment was partially reversed, suggesting that induction of ALL cell apoptosis by ibrutinib was partially attributed to activation of ER stress. In summary, we showed novel data that ER-stress induced cell apoptosis plays a key role in the therapeutic effects of ibrutinib on ALL cell malignancies.

Neutralization of the oedematogenic activity of Bothrops jararaca venom on the mouse paw by an antibothropic fraction isolated from opossum (Didelphis marsupialis) serum.

PubMed

Perales, J; Amorim, C Z; Rocha, S L; Domont, G B; Moussatché, H

1992-11-01

The pharmacological modulation of mice paw oedema produced by Bothrops jararaca venom (BJV) has been studied. Intraplantar injection of BJV (1-30 micrograms/paw) produced a dose- and time-related oedema, which was maximal 30 min after injection, reduced gradually thereafter and disappeared over 48 h. BJV heated at 100 degrees C for 5 or 15 min blocked local hemorrhage and caused partial inhibition of its oedematogenic activity. The BJV oedema was not inhibited by the anti-histamine meclizine, the inhibitor of histamine and serotonin, cyproheptadine, PAF-acether antagonist WEB 2170 or by the anti-leukotrienes C4/D4, LY 171883. Dexamethasone, aspirin, indomethacin, and the dual cyclooxygenase and lipoxygenase inhibitor BW 755C inhibited BJV-induced oedema indicating that arachidonic acid metabolism products via the cyclooxygenase pathway participate in its genesis and/or maintenance. The antibothropic fraction (ABF) (25-200 micrograms/paw) isolated from Didelphis marsupialis serum neutralized the oedema induced by the venom with and without heating, the hemorrhage induced by BJV and partially blocked the oedema induced by bradykinin and by cellulose sulphate. The oedema produced by histamine, serotonin, PAF-acether or leukotriene C4 was not inhibited.

The p53-Reactivating Small Molecule RITA Induces Senescence in Head and Neck Cancer Cells

PubMed Central

Chuang, Hui-Ching; Yang, Liang Peng; Fitzgerald, Alison L.; Osman, Abdullah; Woo, Sang Hyeok; Myers, Jeffrey N.; Skinner, Heath D.

2014-01-01

TP53 is the most commonly mutated gene in head and neck cancer (HNSCC), with mutations being associated with resistance to conventional therapy. Restoring normal p53 function has previously been investigated via the use of RITA (reactivation of p53 and induction of tumor cell apoptosis), a small molecule that induces a conformational change in p53, leading to activation of its downstream targets. In the current study we found that RITA indeed exerts significant effects in HNSCC cells. However, in this model, we found that a significant outcome of RITA treatment was accelerated senescence. RITA-induced senescence in a variety of p53 backgrounds, including p53 null cells. Also, inhibition of p53 expression did not appear to significantly inhibit RITA-induced senescence. Thus, this phenomenon appears to be partially p53-independent. Additionally, RITA-induced senescence appears to be partially mediated by activation of the DNA damage response and SIRT1 (Silent information regulator T1) inhibition, with a synergistic effect seen by combining either ionizing radiation or SIRT1 inhibition with RITA treatment. These data point toward a novel mechanism of RITA function as well as hint to its possible therapeutic benefit in HNSCC. PMID:25119136

G protein-coupled estrogen receptor 1 (GPER 1) mediates estrogen-induced, proliferation of leiomyoma cells.

PubMed

Jiang, Xiuxiu; Ye, Xiaolei; Ma, Junyan; Li, Wen; Wu, Ruijin; Jun, Lin

2015-01-01

G protein-coupled estrogen receptor 1 (GPER-1, formerly known as GPR30) has been proposed as the receptor for estrogen-induced, growth of leiomyomas though its precise mechanisms of action are not clear. We obtained leiomyoma cells (LC) and normal smooth muscle cells from 28 women (n = 28, median age 38 years, median parity 1.0). We incubated them with 17-β estradiol (E(2)), after blocking, or upregulating, expression of GPER-1 with ICI182,780 (a GPER-1 agonist) and siGPR30, respectively. We evaluated the role of GPER-1 in the mitogen-activated protein kinase (MAPK) signaling pathway using Western blot analysis. We studied cell proliferation with 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide, and, mitotic activity with phosphohistone H3 (PPH3) expression in leiomyoma, and, matched, normal, smooth muscle tissues using standard immunohistochemistry. Downregulation of GPER-1 expression with siGPR30 partially attenuated the E(2)-activated MAPK signaling pathway (p < 0.01). Upregulation of GPER-1 with ICI182,780 enhanced the E(2)-activated MAPK signaling pathway (p < 0.01). ICI182,780 enhanced E(2)-induced proliferation of LC (p < 0.01), while knock down of the GPER-1 gene with GPER-1 small interfering RNA partially inhibited E(2)-induced cell proliferation (p < 0.01). There were no significant differences in PPH3 expression between LCs and normal smooth muscle tissues (p > 0.05). Neither ICI182,780 nor siGPR30 increased mitosis in LCs (p > 0.05). Our results indicate that GPER-1 mediates proliferation of estrogen-induced, LC by activating the MAPK pathway, and, not by promoting mitosis.

Effects of Hydrogen-Rich Saline on Hepatectomy-Induced Postoperative Cognitive Dysfunction in Old Mice.

PubMed

Tian, Yue; Guo, Shanbin; Zhang, Yan; Xu, Ying; Zhao, Ping; Zhao, Xiaochun

2017-05-01

This study aims to investigate the protective effects and underlying mechanisms of hydrogen-rich saline on the cognitive functions of elder mice with partial hepatectomy-induced postoperative cognitive dysfunction (POCD). Ninety-six old male Kunming mice were randomly divided into 4 groups (n = 24 each): control group (group C), hydrogen-rich saline group (group H), POCD group (group P), and POCD + hydrogen-rich saline group (group PH). Cognitive function was subsequently assessed using Morris water-maze (MWM) test. TNF-α and IL-1β levels were measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, along with NF-κB activity determined by ELISA. The morphology of hippocampal tissues were further observed by HE staining. Learning and memory abilities of mice were significantly impaired at day 10 and day 14 post-surgery, as partial hepatectomy significantly prolonged the escape latency, decreased time at the original platform quadrant and frequency of crossing in group P when compared to group C (p < 0.05). The surgery also increased the contents of TNF-α, IL-1β, and NF-κB activity at all time points after surgery (p < 0.05). The introduction of hydrogen-rich saline (group PH) partially rescued spatial memory and learning as it shortened escape latency and increased time and crossing frequency of original platform compared to group P (p < 0.05). Moreover, such treatment also decreased TNF-α and IL-1β levels and NF-κB activity (p < 0.05). In addition, cell necrosis in the hippocampus induced by hepatectomy was also rescued by hydrogen-rich saline. Hydrogen-rich saline can alleviate POCD via inhibiting NF-κB activity in the hippocampus and reducing inflammatory response.

TORC1 activity is partially reduced under nitrogen starvation conditions in sake yeast Kyokai no. 7, Saccharomyces cerevisiae.

PubMed

Nakazawa, Nobushige; Sato, Aya; Hosaka, Masahiro

2016-03-01

Industrial yeasts are generally unable to sporulate but treatment with the immunosuppressive drug rapamycin restores this ability in a sake yeast strain Kyokai no. 7 (K7), Saccharomyces cerevisiae. This finding suggests that TORC1 is active under sporulation conditions. Here, using a reporter gene assay, Northern and Western blots, we tried to gain insight into how TORC1 function under nitrogen starvation conditions in K7 cells. Similarly to a laboratory strain, RPS26A transcription was repressed and Npr1 was dephosphorylated in K7 cells, indicative of the expected loss of TORC1 function under nitrogen starvation. The expression of nitrogen catabolite repression-sensitive genes, however, was not induced, the level of Cln3 remained constant, and autophagy was more slowly induced than in a laboratory strain, all suggestive of active TORC1. We conclude that TORC1 activity is partially reduced under nitrogen starvation conditions in K7 cells. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Agonist Met antibodies define the signalling threshold required for a full mitogenic and invasive program of Kaposi's Sarcoma cells.

PubMed

Bardelli, Claudio; Sala, Marilena; Cavallazzi, Umberto; Prat, Maria

2005-09-09

We previously showed that the Kaposi Sarcoma line KS-IMM express a functional Met tyrosine kinase receptor, which, upon HGF stimulation, activates motogenic, proliferative, and invasive responses. In this study, we investigated the signalling pathways activated by HGF, as well as by Met monoclonal antibodies (Mabs), acting as full or partial agonists. The full agonist Mab mimics HGF in all biological and biochemical aspects. It elicits the whole spectrum of responses, while the partial agonist Mab induces only wound healing. These differences correlated with a more prolonged and sustained tyrosine phosphorylation of the receptor and MAPK evoked by HGF and by the full agonist Mab, relative to the partial agonist Mab. Since Gab1, JNK and PI 3-kinase are activated with same intensity and kinetics by HGF and by the two agonist antibodies, it is concluded that level and duration of MAPK activation by Met receptor are crucial for the induction of a full HGF-dependent mitogenic and invasive program in KS cells.

Prevention of TGF-beta-induced apoptosis by interlukin-4 through Akt activation and p70S6K survival signaling pathways.

PubMed

Lin, Sue-Jane; Chang, Chungming; Ng, Ah-Kau; Wang, Shu-Han; Li, Jia-Je; Hu, Cheng-po

2007-09-01

In this study, we demonstrate that interleukin-4 (IL-4) protects human hepatocellular carcinoma (HCC) cell line Hep3B from apoptosis induced by transforming growth factor-beta (TGF-beta). Further investigation of IL-4-transduced signaling pathways revealed that both insulin response substrate 1 and 2 (IRS-1/-2) and extracellular signal-regulated kinase (ERK) pathways were activated after IL-4 stimulation. The IRS-1/-2 activation was accompanied by the activation of phosphotidylinositol-3-kinase (PI3K), leading to Akt and p70 ribosomal protein S6 kinase (p70S6K). Interestingly, a protein kinase C (PKC) inhibitor, Gö6976, inhibited the phosphorylation of Akt, suggesting that the Akt activation was PKC-dependent. Using specific inhibitors for PI3K or ERK, we demonstrated that the PI3K pathway, but not the ERK pathway, was required for protection. The constitutively active form of PI3K almost completely rescued TGF-beta-induced apoptosis, further supporting the importance of the PI3K pathway in the protective effect of IL-4. Furthermore, a dominant negative Akt and/or Gö6976 only partially blocked the anti-apoptotic effect of IL-4. Similarly, rapamycin, which interrupted the activation of p70S6K, also only partially blocked the protective effect of IL-4. However, in the presence of both rapamycin and dominant negative Akt with or without Gö6976, IL-4 almost completely lost the anti-apoptotic effect, suggesting that both Akt and p70S6K pathways were required for the protective effect of IL-4 against TGF-beta-induced apoptosis.

Downy mildew resistance induced by Trichoderma harzianum T39 in susceptible grapevines partially mimics transcriptional changes of resistant genotypes

PubMed Central

2012-01-01

Background Downy mildew, caused by Plasmopara viticola, is one of the most severe diseases of grapevine and is commonly controlled by fungicide treatments. The beneficial microorganism Trichoderma harzianum T39 (T39) can induce resistance to downy mildew, although the molecular events associated with this process have not yet been elucidated in grapevine. A next generation RNA sequencing (RNA-Seq) approach was used to study global transcriptional changes associated with resistance induced by T39 in Vitis vinifera Pinot Noir leaves. The long-term aim was to develop strategies to optimize the use of this agent for downy mildew control. Results More than 14.8 million paired-end reads were obtained for each biological replicate of T39-treated and control leaf samples collected before and 24 h after P. viticola inoculation. RNA-Seq analysis resulted in the identification of 7,024 differentially expressed genes, highlighting the complex transcriptional reprogramming of grapevine leaves during resistance induction and in response to pathogen inoculation. Our data show that T39 has a dual effect: it directly modulates genes related to the microbial recognition machinery, and it enhances the expression of defence-related processes after pathogen inoculation. Whereas several genes were commonly affected by P. viticola in control and T39-treated plants, opposing modulation of genes related to responses to stress and protein metabolism was found. T39-induced resistance partially inhibited some disease-related processes and specifically activated defence responses after P. viticola inoculation, causing a significant reduction of downy mildew symptoms. Conclusions The global transcriptional analysis revealed that defence processes known to be implicated in the reaction of resistant genotypes to downy mildew were partially activated by T39-induced resistance in susceptible grapevines. Genes identified in this work are an important source of markers for selecting novel resistance inducers and for the analysis of environmental conditions that might affect induced resistance mechanisms. PMID:23173562

Ciclopirox induces autophagy through reactive oxygen species-mediated activation of JNK signaling pathway

PubMed Central

Zhou, Hongyu; Shen, Tao; Shang, Chaowei; Luo, Yan; Liu, Lei; Yan, Juming; Li, Yan; Huang, Shile

2014-01-01

Ciclopirox olamine (CPX), a fungicide, has been demonstrated as a potential anticancer agent. However, the underlying anticancer mechanism is not well understood. Here, we found that CPX induced autophagy in human rhabdomyosarcoma (Rh30 and RD) cells. It appeared that CPX-induced autophagy was attributed to induction of reactive oxygen species (ROS), as N-acetyl-L-cysteine (NAC), a ROS scavenger and antioxidant, prevented this process. Furthermore, we observed that CPX induced activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 MAPK, which was also blocked by NAC. However, only inhibition of JNK (with SP600125) or expression of dominant negative c-Jun partially prevented CPX-induced autophagy, indicating that ROS-mediated activation of JNK signaling pathway contributed to CPX-induced autophagy. Of interest, inhibition of autophagy by chloroquine (CQ) enhanced CPX-induced cell death, indicating that CPX-induced autophagy plays a pro-survival role in human rhabdomyosarcoma cells. Our finding suggests that the combination with autophagy inhibitors may be a novel strategy in potentiating the anticancer activity of CPX for treatment of rhabdomyosarcoma. PMID:25294812

Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization

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

Meng, Zhen; Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081; Gan, Ye-Hua, E-mail: kqyehuagan@bjmu.edu.cn

2015-05-01

Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocationmore » and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. - Highlights: • COX-2 inhibitor, celecoxib, could enhance radiosensitization. • Radiation induced PTEN inactivation (phosphorylation) and AKT activation. • COX-2 inhibitor induced PTEN expression and activation, and inactivated AKT. • COX-2 inhibitor enhanced radiosensitization through activating PTEN.« less

Chloroplastic thioredoxin-f and thioredoxin-m1/4 play important roles in brassinosteroids-induced changes in CO2 assimilation and cellular redox homeostasis in tomato

PubMed Central

Cheng, Fei; Zhou, Yan-Hong; Xia, Xiao-Jian; Shi, Kai; Zhou, Jie; Yu, Jing-Quan

2014-01-01

Chloroplast thioredoxins (TRXs) and glutathione function as redox messengers in the regulation of photosynthesis. In this work, the roles of chloroplast TRXs in brassinosteroids (BRs)-induced changes in cellular redox homeostasis and CO2 assimilation were studied in the leaves of tomato plants. BRs-deficient d ^im plants showed decreased transcripts of TRX-f, TRX-m2, TRX-m1/4, and TRX-x, while exogenous BRs significantly induced CO2 assimilation and the expression of TRX-f, TRX-m2, TRX-m1/4, and TRX-x. Virus-induced gene silencing (VIGS) of the chloroplast TRX-f, TRX-m2, TRX-m1/4, and TRX-y genes individually increased membrane lipid peroxidation and accumulation of 2-Cys peroxiredoxin dimers, and decreased the activities of the ascorbate–glutathione cycle enzymes and the ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) in the leaves. Furthermore, partial silencing of TRX-f, TRX-m2, TRX-m1/4, and TRX-y resulted in decreased expression of genes involved in the Benson–Calvin cycle and decreased activity of the associated enzymes. Importantly, the BRs-induced increase in CO2 assimilation and the increased expression and activities of antioxidant- and photosynthesis-related genes and enzymes were compromised in the partially TRX-f- and TRX-m1/4-silenced plants. All of these results suggest that TRX-f and TRX-m1/4 are involved in the BRs-induced changes in CO2 assimilation and cellular redox homeostasis in tomato. PMID:24847092

Different Epidermal Growth Factor (EGF) Receptor Ligands Show Distinct Kinetics and Biased or Partial Agonism for Homodimer and Heterodimer Formation*

PubMed Central

Macdonald-Obermann, Jennifer L.; Pike, Linda J.

2014-01-01

The EGF receptor has seven different cognate ligands. Previous work has shown that these different ligands are capable of inducing different biological effects, even in the same cell. To begin to understand the molecular basis for this variation, we used luciferase fragment complementation to measure ligand-induced dimer formation and radioligand binding to study the effect of the ligands on subunit-subunit interactions in EGF receptor (EGFR) homodimers and EGFR/ErbB2 heterodimers. In luciferase fragment complementation imaging studies, amphiregulin (AREG) functioned as a partial agonist, inducing only about half as much total dimerization as the other three ligands. However, unlike the other ligands, AREG showed biphasic kinetics for dimer formation, suggesting that its path for EGF receptor activation involves binding to both monomers and preformed dimers. EGF, TGFα, and betacellulin (BTC) appear to mainly stimulate receptor activation through binding to and dimerization of receptor monomers. In radioligand binding assays, EGF and TGFα exhibited increased affinity for EGFR/ErbB2 heterodimers compared with EGFR homodimers. By contrast, BTC and AREG showed a similar affinity for both dimers. Thus, EGF and TGFα are biased agonists, whereas BTC and AREG are balanced agonists with respect to selectivity of dimer formation. These data suggest that the differences in biological response to different EGF receptor ligands may result from partial agonism for dimer formation, differences in the kinetic pathway utilized to generate activated receptor dimers, and biases in the formation of heterodimers versus homodimers. PMID:25086039

Elevation of GM2 ganglioside during ethanol-induced apoptotic neurodegeneration in the developing mouse brain

PubMed Central

Saito, Mitsuo; Chakraborty, Goutam; Shah, Relish; Mao, Rui-Fen; Kumar, Asok; Yang, Dun-Sheng; Dobrenis, Kostantin; Saito, Mariko

2012-01-01

GM2 ganglioside in the brain increased during ethanol-induced acute apoptotic neurodegeneration in 7-day-old mice. A small but a significant increase observed 2 h after ethanol exposure was followed by a marked increase around 24 h. Subcellular fractionation of the brain 24 h after ethanol treatment indicated that GM2 increased in synaptic and non-synaptic mitochondrial fractions as well as in a lysosome-enriched fraction characteristic to the ethanol-exposed brain. Immunohistochemical staining of GM2 in the ethanol-treated brain showed strong punctate staining mainly in activated microglia, in which it partially overlapped with staining for LAMP1, a late endosomal/lysosomal marker. Also, there was weaker neuronal staining, which partially co-localized with complex IV, a mitochondrial marker, and was augmented in cleaved caspase-3-positive neurons. In contrast, the control brain showed only faint and diffuse GM2 staining in neurons. Incubation of isolated brain mitochondria with GM2 in vitro induced cytochrome c release in a manner similar to that of GD3 ganglioside. Because ethanol is known to trigger mitochondria-mediated apoptosis with cytochrome c release and caspase-3 activation in the 7-day–old mouse brain, the GM2 elevation in mitochondria may be relevant to neuroapoptosis. Subsequently, activated microglia accumulated GM2, indicating a close relationship between GM2 and ethanol-induced neurodegeneration. PMID:22372857

The relaxation induced by S-nitroso-glutathione and S-nitroso-N-acetylcysteine in rat aorta is not related to nitric oxide production.

PubMed

Ceron, P I; Cremonez, D C; Bendhack, L M; Tedesco, A C

2001-08-01

S-nitroso-glutathione (GSNO) and S-nitroso-N-acetylcysteine (NACysNO) are nitrosothiols that release nitric oxide (NO) and mimic the effects of endogenous NO. This study investigated the relaxation induced by GSNO and NACysNO in rat aorta and the relation between relaxation and NO formation. Both compounds at concentrations from 10(-9) M to 10(-4) M relaxed the rat aorta in a concentration-dependent manner. However, NO production depended on the concentration of nitrosothiols present and was detected only above 100 microM GSNO or NACysNO. To determine whether K+ channels are involved in the relaxation induced by nitrosothiols, the contractions were induced with KCl at concentrations of 30, 60, or 90 mM. The concentration-effect curves for the relaxation induced by nitrosothiols were shifted to the right for all the K+ concentrations compared with aortas precontracted with phenylephrine. These results indicate the participation of K+ channels in the relaxation induced by GSNO and NACysNO. A selective inhibitor of soluble guanylyl cyclase, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, significantly inhibited the relaxation induced by the nitrosothiols. The relaxation induced by GSNO and NACysNO was inhibited by the K+ channel blockers glibenclamide, selective K(ATP) channels, and apamin, selective for low-conductance Ca2+-activated K+ channels in rat aorta, but was not inhibited by charybdotoxin, a potent and selective Ca2+-activated K+ channel blocker, or by 4-aminopyridine, a voltage-gated K+ channel blocker. These results indicate that relaxation induced by GSNO and NACysNO is partially due to activation of K(ATP) channels and partially due to activation of low-conductance Ca2+-activated K+ channels. However, the ability of the nitrosothiol compounds to overcome the inhibitory effect of high extracellular K+ concentrations suggests another mechanism of relaxation contributing to the nitrosothiol response. The most intriguing finding is that relaxation is not related to the NO produced in rat aorta.

Dialogue between E. coli free radical pathways and the mitochondria of C. elegans.

PubMed

Govindan, J Amaranath; Jayamani, Elamparithi; Zhang, Xinrui; Mylonakis, Eleftherios; Ruvkun, Gary

2015-10-06

The microbial world presents a complex palette of opportunities and dangers to animals, which have developed surveillance and response strategies to hints of microbial intent. We show here that the mitochondrial homeostatic response pathway of the nematode Caenorhabditis elegans responds to Escherichia coli mutations that activate free radical detoxification pathways. Activation of C. elegans mitochondrial responses could be suppressed by additional mutations in E. coli, suggesting that C. elegans responds to products of E. coli to anticipate challenges to its mitochondrion. Out of 50 C. elegans gene inactivations known to mediate mitochondrial defense, we found that 7 genes were required for C. elegans response to a free radical producing E. coli mutant, including the bZip transcription factor atfs-1 (activating transcription factor associated with stress). An atfs-1 loss-of-function mutant was partially resistant to the effects of free radical-producing E. coli mutant, but a constitutively active atfs-1 mutant growing on wild-type E. coli inappropriately activated the pattern of mitochondrial responses normally induced by an E. coli free radical pathway mutant. Carbonylated proteins from free radical-producing E. coli mutant may directly activate the ATFS-1/bZIP transcription factor to induce mitochondrial stress response: feeding C. elegans with H2O2-treated E. coli induces the mitochondrial unfolded protein response, and inhibition of a gut peptide transporter partially suppressed C. elegans response to free radical damaged E. coli.

Reversible exposure of hydrophobic residues on albumin as a novel strategy for formulation of nanodelivery vehicles for taxanes

PubMed Central

Garro, AG; Beltramo, DM; Alasino, RV; Leonhard, V; Heredia, V; Bianco, ID

2011-01-01

Background: We report herein a novel strategy for the preparation of protein-based nanode-livery vehicles for hydrophobic active pharmaceutical ingredients. Methods: The procedure consisted of three steps, ie, exposure of hydrophobic residues of a protein to a pH-induced partial unfolding: interaction between hydrophobic residues on the protein and the hydrophobic active pharmaceutical ingredient, and a final step where the structure of the protein was reversed to a native-like state by returning to neutral pH. As proof of concept, the interaction of paclitaxel with partially unfolded states of human serum albumin was evaluated as a potential method for the preparation of water-soluble complexes of the taxane with albumin. Results: We found that paclitaxel readily binds to pH-induced partially unfolded albumin, leading to the formation of optically clear water-soluble complexes. The complexes thus formed were more stable in solution when the albumin native state was at least partially restored by neutralization of the solution to a pH around 7. It was also observed that the hydrodynamic radius of human serum albumin was only slightly increased after the cycle of pH changes, remaining in a monomeric state with a size according to paclitaxel binding. Furthermore, paclitaxel binding did not affect the overall exposure of charged groups of human serum albumin, as evaluated by its interaction with an ionic exchange resin. Conclusion: The in vitro biological activity of the complexes formed was qualitatively equivalent to that of a Cremophor®-based formulation. PMID:21822381

Gene regulation mediating fiber-type transformation in skeletal muscle cells is partly glucose- and ChREBP-dependent.

PubMed

Hanke, Nina; Scheibe, Renate J; Manukjan, Georgi; Ewers, David; Umeda, Patrick K; Chang, Kin-Chow; Kubis, Hans-Peter; Gros, Gerolf; Meissner, Joachim D

2011-03-01

Adaptations in the oxidative capacity of skeletal muscle cells can occur under several physiological or pathological conditions. We investigated the effect of increasing extracellular glucose concentration on the expression of markers of energy metabolism in primary skeletal muscle cells and the C2C12 muscle cell line. Growth of myotubes in 25mM glucose (high glucose, HG) compared with 5.55mM led to increases in the expression and activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a marker of glycolytic energy metabolism, while oxidative markers peroxisome proliferator-activated receptor γ coactivator 1α and citrate synthase decreased. HG induced metabolic adaptations as are seen during a slow-to-fast fiber transformation. Furthermore, HG increased fast myosin heavy chain (MHC) IId/x but did not change slow MHCI/β expression. Protein phosphatase 2A (PP2A) was shown to mediate the effects of HG on GAPDH and MHCIId/x. Carbohydrate response element-binding protein (ChREBP), a glucose-dependent transcription factor downstream of PP2A, partially mediated the effects of glucose on metabolic markers. The glucose-induced increase in PP2A activity was associated with an increase in p38 mitogen-activated protein kinase activity, which presumably mediates the increase in MHCIId/x promoter activity. Liver X receptor, another possible mediator of glucose effects, induced only an incomplete metabolic shift, mainly increasing the expression of the glycolytic marker. Taken together, HG induces a partial slow-to-fast transformation comprising metabolic enzymes together with an increased expression of MHCIId/x. This work demonstrates a functional role for ChREBP in determining the metabolic type of muscle fibers and highlights the importance of glucose as a signaling molecule in muscle. Copyright © 2011 Elsevier B.V. All rights reserved.

Autism-associated R451C mutation in neuroligin3 leads to activation of the unfolded protein response in a PC12 Tet-On inducible system

PubMed Central

Ulbrich, Lisa; Favaloro, Flores Lietta; Trobiani, Laura; Marchetti, Valentina; Patel, Vruti; Pascucci, Tiziana; Comoletti, Davide; Marciniak, Stefan J.; De Jaco, Antonella

2015-01-01

Several forms of monogenic heritable autism spectrum disorders are associated with mutations in the neuroligin genes. The autism-linked substitution R451C in neuroligin3 induces local misfolding of its extracellular domain, causing partial retention in the ER (endoplasmic reticulum) of expressing cells. We have generated a PC12 Tet-On cell model system with inducible expression of wild-type or R451C neuroligin3 to investigate whether there is activation of the UPR (unfolded protein response) as a result of misfolded protein retention. As a positive control for protein misfolding, we also expressed the mutant G221R neuroligin3, which is known to be completely retained within the ER. Our data show that overexpression of either R451C or G221R mutant proteins leads to the activation of all three signalling branches of the UPR downstream of the stress sensors ATF6 (activating transcription factor 6), IRE1 (inositol-requiring enzyme 1) and PERK [PKR (dsRNA-dependent protein kinase)-like endoplasmic reticulum kinase]. Each branch displayed different activation profiles that partially correlated with the degree of misfolding caused by each mutation. We also show that up-regulation of BiP (immunoglobulin heavy-chain-binding protein) and CHOP [C/EBP (CCAAT/enhancer-binding protein)-homologous protein] was induced by both mutant proteins but not by wild-type neuroligin3, both in proliferative cells and cells differentiated to a neuron-like phenotype. Collectively, our data show that mutant R451C neuroligin3 activates the UPR in a novel cell model system, suggesting that this cellular response may have a role in monogenic forms of autism characterized by misfolding mutations. PMID:26621873

Effect of a total extract from Fraxinus ornus stem bark and esculin on zymosan- and carrageenan-induced paw oedema in mice.

PubMed

Stefanova, Z; Neychev, H; Ivanovska, N; Kostova, I

1995-05-01

This study investigates the total ethanol extract (TE) of the stem bark of Fraxinus ornus and its constituent esculin (EN). They inhibited classical pathway (CP) and alternative pathway (AP) of complement activation in mouse serum. After intraperitoneal administration the total extract displayed antiinflammatory activity in both zymosan- and carrageenan-induced paw oedema in mice. The results suggest that the traditional use of Fraxinus ornus stem bark extracts in the treatment of inflammatory disorders is at least partially due to its coumarin constituents.

Departure gate of acidic Ca2+ confirmed

PubMed Central

Jentsch, Thomas J; Hoegg-Beiler, Maja B; Vogt, Janis

2015-01-01

More potent, but less known than IP3 that liberates Ca2+ from the ER, NAADP releases Ca2+ from acidic stores. The notion that TPC channels mediate this Ca2+ release was questioned recently by studies suggesting that TPCs are rather PI(3,5)P2-activated Na+ channels. Ruas et al (2015) now partially reconcile these views by showing that TPCs significantly conduct both cations and confirm their activation by both NAADP and PI(3,5)P2. They attribute the failure of others to observe TPC-dependent NAADP-induced Ca2+ release in vivo to inadequate mouse models that retain partial TPC function. PMID:26022292

Endothelial microvesicles in hypoxic hypoxia diseases.

PubMed

Deng, Fan; Wang, Shuang; Xu, Riping; Yu, Wenqian; Wang, Xianyu; Zhang, Liangqing

2018-05-29

Hypoxic hypoxia, including abnormally low partial pressure of inhaled oxygen, external respiratory dysfunction-induced respiratory hypoxia and venous blood flow into the arterial blood, is characterized by decreased arterial oxygen partial pressure, resulting in tissue oxygen deficiency. The specific characteristics include reduced arterial oxygen partial pressure and oxygen content. Hypoxic hypoxia diseases (HHDs) have attracted increased attention due to their high morbidity and mortality and mounting evidence showing that hypoxia-induced oxidative stress, coagulation, inflammation and angiogenesis play extremely important roles in the physiological and pathological processes of HHDs-related vascular endothelial injury. Interestingly, endothelial microvesicles (EMVs), which can be induced by hypoxia, hypoxia-induced oxidative stress, coagulation and inflammation in HHDs, have emerged as key mediators of intercellular communication and cellular functions. EMVs shed from activated or apoptotic endothelial cells (ECs) reflect the degree of ECs damage, and elevated EMVs levels are present in several HHDs, including obstructive sleep apnoea syndrome and chronic obstructive pulmonary disease. Furthermore, EMVs have procoagulant, proinflammatory and angiogenic functions that affect the pathological processes of HHDs. This review summarizes the emerging roles of EMVs in the diagnosis, staging, treatment and clinical prognosis of HHDs. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Inhibitory effect of baicalin on iNOS and NO expression in intestinal mucosa of rats with acute endotoxemia.

PubMed

Feng, Aiwen; Zhou, Guangrong; Yuan, Xiaoming; Huang, Xinli; Zhang, Zhengyuan; Zhang, Ti

2013-01-01

The mechanism by which baicalin modulated the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) in the mucosa of distal ileum was investigated in a rat model of acute endo-toxemia induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS). The experiment demonstrated that LPS upregulated iNOS mRNA and protein expression as well as NO produc-tion (measured as the stable degradation production, nitrites). LPS not only increased toll-like receptor 4 (TLR4) and peroxisome proliferator-activated receptor gamma (PPARγ) content, but also activated p38 and activating transcription factor 2 (ATF2) and inactivated PPARγ via phosphorylation. Inhibition of p38 signalling pathway by chemical inhibitor SB202190 and small interfering RNA (siRNA) ameliorated LPS-induced iNOS generation, while suppression of PPARγ pathway by SR-202 boosted LPS-elicited iNOS expression. Baicalin treatment (I) attenuated LPS-induced iNOS mRNA and protein as well as nitrites generation, and (II) ameliorated LPS-elicited TLR4 and PPARγ production, and (III) inhibited p38/ATF2 phosphorylation leading to suppression of p38 signalling, and (IV) prevented PPARγ from phosphorylation contributing to maintainence of PPARγ bioactivity. However, SR-202 co-treatment (I) partially abrogated the inhibitory effect of baicalin on iNOS mRNA expression, and (II) partially reversed baicalin-inhibited p38 phosphorylation. In summary, baicalin could ameliorate LPS-induced iNOS and NO overproduction in mucosa of rat terminal ileum via inhibition of p38 signalling cascade and activation of PPARγ pathway. There existed a interplay between the two signalling pathways.

[Effect of endotoxin pretreatment-induced glycogen synthase kinase-3 inhibition on glycogen metabolism in rat liver and the mechanism].

PubMed

Chen, Xiaole; Gong, Jianping; Xu, Faliang

2014-02-01

To investigate the changes in the functional activity of glycogen synthase kinase-3 (GSK-3) in the hepatic tissue after endotoxin (lipopolysaccharide, LPS) tolerance and explore the effects of LPS-induced GSK-3 inhibition on glycogen metabolism in the liver. Male SD rats were randomly divided into normal control, endotoxin pretreatment and GSK-3 inhibitor (lithium chloride) groups with corresponding pretreatments prior to a large dose of LPS challenge (10 mg/kg) to induce liver injury. Glycogen deposition and content in the hepatic tissue was detected using periodic acid-Schiff (PAS) staining and a glycogen quantification kit, respectively. Western blotting was performed for semi-quantitative analysis of protein level and inhibitory phosphorylation of GSK-3, and a Coomassie brilliant blue G-250-based colorimetric assay was used to detect calpain activity in the liver. Glycogen content in the liver decreased significantly after LPS challenge in all the 3 groups (P<0.05) but showed no significant difference among the groups (P>0.05). Both LPS and lithium chloride pretreatments caused a significant increase of liver glycogen content (P<0.05). LPS pretreatment induced inhibitory phosphorylation of GSK-3β (P<0.05) and partial cleavage of GSK-3α but did not affect the expression of GSK-3 protein (P>0.05). Large-dose LPS challenge significantly increased the activity of calpain in the liver tissue (P<0.05) to a comparable level in the 3 groups (P>0.05). Endotoxin pretreatment induces inhibitory phosphorylation of GSK-3β and partial cleavage of GSK-3α and promotes the deposition of liver glycogen but does not affect the activity of calpain, which may contribute to an increased glycogen reserve for energy supply in the event of large-dose LPS challenge.

Inhibitory Effect of Baicalin on iNOS and NO Expression in Intestinal Mucosa of Rats with Acute Endotoxemia

PubMed Central

Yuan, Xiaoming; Huang, Xinli; Zhang, Zhengyuan; Zhang, Ti

2013-01-01

The mechanism by which baicalin modulated the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) in the mucosa of distal ileum was investigated in a rat model of acute endo-toxemia induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS). The experiment demonstrated that LPS upregulated iNOS mRNA and protein expression as well as NO produc-tion (measured as the stable degradation production, nitrites). LPS not only increased toll-like receptor 4 (TLR4) and peroxisome proliferator-activated receptor gamma (PPARγ) content, but also activated p38 and activating transcription factor 2 (ATF2) and inactivated PPARγ via phosphorylation. Inhibition of p38 signalling pathway by chemical inhibitor SB202190 and small interfering RNA (siRNA) ameliorated LPS-induced iNOS generation, while suppression of PPARγ pathway by SR-202 boosted LPS-elicited iNOS expression. Baicalin treatment (I) attenuated LPS-induced iNOS mRNA and protein as well as nitrites generation, and (II) ameliorated LPS-elicited TLR4 and PPARγ production, and (III) inhibited p38/ATF2 phosphorylation leading to suppression of p38 signalling, and (IV) prevented PPARγ from phosphorylation contributing to maintainence of PPARγ bioactivity. However, SR-202 co-treatment (I) partially abrogated the inhibitory effect of baicalin on iNOS mRNA expression, and (II) partially reversed baicalin-inhibited p38 phosphorylation. In summary, baicalin could ameliorate LPS-induced iNOS and NO overproduction in mucosa of rat terminal ileum via inhibition of p38 signalling cascade and activation of PPARγ pathway. There existed a interplay between the two signalling pathways. PMID:24312512

The TAT-RasGAP317-326 anti-cancer peptide can kill in a caspase-, apoptosis-, and necroptosis-independent manner

PubMed Central

Puyal, Julien; Margue, Christiane; Michel, Sébastien; Kreis, Stephanie; Kulms, Dagmar; Barras, David; Nahimana, Aimable; Widmann, Christian

2016-01-01

Tumor cell resistance to apoptosis, which is triggered by many anti-tumor therapies, remains a major clinical problem. Therefore, development of more efficient therapies is a priority to improve cancer prognosis. We have previously shown that a cell-permeable peptide derived from the p120 Ras GTPase-activating protein (RasGAP), called TAT-RasGAP317-326, bears anti-malignant activities in vitro and in vivo, such as inhibition of metastatic progression and tumor cell sensitization to cell death induced by various anti-cancer treatments. Recently, we discovered that this RasGAP-derived peptide possesses the ability to directly kill some cancer cells. TAT-RasGAP317-326 can cause cell death in a manner that can be either partially caspase-dependent or fully caspase-independent. Indeed, TAT-RasGAP317-326-induced toxicity was not or only partially prevented when apoptosis was inhibited. Moreover, blocking other forms of cell death, such as necroptosis, parthanatos, pyroptosis and autophagy did not hamper the killing activity of the peptide. The death induced by TAT-RasGAP317-326 can therefore proceed independently from these modes of death. Our finding has potentially interesting clinical relevance because activation of a death pathway that is distinct from apoptosis and necroptosis in tumor cells could lead to the generation of anti-cancer drugs that target pathways not yet considered for cancer treatment. PMID:27602963

Effect of antioxidants on vanadate-induced toxicity towards isolated perfused rat livers.

PubMed

Younes, M; Kayser, E; Strubelt, O

1991-01-01

The effect of trolox C, a water soluble vitamin E analogue, propyl gallate and ascorbate on vanadate hepatotoxicity was investigated in vitro. In isolated perfused livers from fasted rats, sodium orthovanadate (2 mmol/l) led to toxic responses including reduction of oxygen consumption, release of cytosolic (glutamate-pyruvate-transaminase (GPT) and lactate dehydrogenase (LDH)) and mitochondrial (glutamate-dehydrogenase (GLDH)) enzymes, intracellular accumulation of calcium, a marked depletion of glutathione (GSH) and an enhanced formation and release of thiobarbituric acid- (TBA) reactive material. Trolox C and propyl gallate inhibited the release of GPT and LDH partially and that of GLDH totally, but had no influence on vanadate-induced calcium accumulation or on the reduction of oxygen consumption. Both agents suppressed vanadate-induced lipid peroxidation (LPO) and partially prevented GSH depletion. Ascorbate failed to provide any protection probably due to the interference of its pro-oxidant potential with its antioxidant activity. The protection, mainly of mitochondria, afforded by those agents which also inhibited LPO substantiates our previous findings that the pro-oxidant activity of vanadate is mainly responsible for its direct hepatotoxic actions [2]. Besides, reduction of organ perfusion rate due to vasoconstriction also contributes to vanadate toxicity, but oxidative stress is not involved in this indirect toxic activity.

Radiation-induced lung damage promotes breast cancer lung-metastasis through CXCR4 signaling

PubMed Central

Feys, Lynn; Descamps, Benedicte; Vanhove, Christian; Vral, Anne; Veldeman, Liv; Vermeulen, Stefan; De Wagter, Carlos; Bracke, Marc; De Wever, Olivier

2015-01-01

Radiotherapy is a mainstay in the postoperative treatment of breast cancer as it reduces the risks of local recurrence and mortality after both conservative surgery and mastectomy. Despite recent efforts to decrease irradiation volumes through accelerated partial irradiation techniques, late cardiac and pulmonary toxicity still occurs after breast irradiation. The importance of this pulmonary injury towards lung metastasis is unclear. Preirradiation of lung epithelial cells induces DNA damage, p53 activation and a secretome enriched in the chemokines SDF-1/CXCL12 and MIF. Irradiated lung epithelial cells stimulate adhesion, spreading, growth, and (transendothelial) migration of human MDA-MB-231 and murine 4T1 breast cancer cells. These metastasis-associated cellular activities were largely mimicked by recombinant CXCL12 and MIF. Moreover, an allosteric inhibitor of the CXCR4 receptor prevented the metastasis-associated cellular activities stimulated by the secretome of irradiated lung epithelial cells. Furthermore, partial (10%) irradiation of the right lung significantly stimulated breast cancer lung-specific metastasis in the syngeneic, orthotopic 4T1 breast cancer model. Our results warrant further investigation of the potential pro-metastatic effects of radiation and indicate the need to develop efficient drugs that will be successful in combination with radiotherapy to prevent therapy-induced spread of cancer cells. PMID:26396176

Radiation-induced lung damage promotes breast cancer lung-metastasis through CXCR4 signaling.

PubMed

Feys, Lynn; Descamps, Benedicte; Vanhove, Christian; Vral, Anne; Veldeman, Liv; Vermeulen, Stefan; De Wagter, Carlos; Bracke, Marc; De Wever, Olivier

2015-09-29

Radiotherapy is a mainstay in the postoperative treatment of breast cancer as it reduces the risks of local recurrence and mortality after both conservative surgery and mastectomy. Despite recent efforts to decrease irradiation volumes through accelerated partial irradiation techniques, late cardiac and pulmonary toxicity still occurs after breast irradiation. The importance of this pulmonary injury towards lung metastasis is unclear. Preirradiation of lung epithelial cells induces DNA damage, p53 activation and a secretome enriched in the chemokines SDF-1/CXCL12 and MIF. Irradiated lung epithelial cells stimulate adhesion, spreading, growth, and (transendothelial) migration of human MDA-MB-231 and murine 4T1 breast cancer cells. These metastasis-associated cellular activities were largely mimicked by recombinant CXCL12 and MIF. Moreover, an allosteric inhibitor of the CXCR4 receptor prevented the metastasis-associated cellular activities stimulated by the secretome of irradiated lung epithelial cells. Furthermore, partial (10%) irradiation of the right lung significantly stimulated breast cancer lung-specific metastasis in the syngeneic, orthotopic 4T1 breast cancer model.Our results warrant further investigation of the potential pro-metastatic effects of radiation and indicate the need to develop efficient drugs that will be successful in combination with radiotherapy to prevent therapy-induced spread of cancer cells.

Fragrant unsaturated aldehydes elicit activation of the Keap1/Nrf2 system leading to the upregulation of thioredoxin expression and protection against oxidative stress.

PubMed

Masutani, Hiroshi; Otsuki, Ryoko; Yamaguchi, Yoshimi; Takenaka, Masahiro; Kanoh, Nobue; Takatera, Koji; Kunimoto, Yuji; Yodoi, Junji

2009-05-01

Thioredoxin, a key molecule in redox regulation, and many redox enzymes are regulated through the antioxidant responsive element (ARE). To search for antioxidative constituents, we screened extracts from vegetables and found that the extracts of Perilla frutescens and Artemisia princeps have potent thioredoxin-inducing activities. By activity-guided purification of Perilla frutescens extracts, we identified perillaldehyde as a novel thioredoxin inducer. Fragrant unsaturated aldehydes, such as trans-cinnamaldehyde, safranal, 2,4-octadienal, citral, trans-2, cis-6-nonadienal, and trans-2-hexenal showed the ability to activate ARE. Perillaldehyde-induced activation through the ARE was suppressed by the overexpression of wild-type Keap1, whereas sulforaphane-induced activation seemed to be partially suppressed. Mutant Keap1 (R272A/K287A or C273A/C288A) did not suppress this activation. Pretreatment with perillaldehyde reduced the H(2)O(2)-induced cytotoxicity. Thus, we show that fragrant unsaturated aldehydes from edible plants are novel thioredoxin inducers and ARE activators and may be beneficial for protection against oxidative stress-induced cellular damage. These results also suggest that perillaldehyde activates the Nrf2-Keap1 system and that the lysine and arginine residues juxtaposed to the critical cysteine residues of Keap1 are required for signal sensing.

FPLC and liquid-chromatography mass spectrometry identify candidate necrosis-inducing proteins from culture filtrates of the fungal wheat pathogen Zymoseptoria tritici.

PubMed

Ben M'Barek, Sarrah; Cordewener, Jan H G; Tabib Ghaffary, Seyed M; van der Lee, Theo A J; Liu, Zhaohui; Mirzadi Gohari, Amir; Mehrabi, Rahim; America, Antoine H P; Robert, Olivier; Friesen, Timothy L; Hamza, Sonia; Stergiopoulos, Ioannis; de Wit, Pierre J G M; Kema, Gerrit H J

2015-06-01

Culture filtrates (CFs) of the fungal wheat pathogen Zymoseptoria tritici were assayed for necrosis-inducing activity after infiltration in leaves of various wheat cultivars. Active fractions were partially purified and characterized. The necrosis-inducing factors in CFs are proteinaceous, heat stable and their necrosis-inducing activity is temperature and light dependent. The in planta activity of CFs was tested by a time series of proteinase K (PK) co-infiltrations, which was unable to affect activity 30min after CF infiltrations. This suggests that the necrosis inducing proteins (NIPs) are either absent from the apoplast and likely actively transported into mesophyll cells or protected from the protease by association with a receptor. Alternatively, plant cell death signaling pathways might be fully engaged during the first 30min and cannot be reversed even after PK treatment. Further fractionation of the CFs with the highest necrosis-inducing activity involved fast performance liquid chromatography, SDS-PAGE and mass spectrometry. This revealed that most of the proteins present in the fractions have not been described before. The two most prominent ZtNIP encoding candidates were heterologously expressed in Pichia pastoris and subsequent infiltration assays showed their differential activity in a range of wheat cultivars. Copyright © 2015 Elsevier Inc. All rights reserved.

Ethanol-Induced Neurodegeneration and Glial Activation in the Developing Brain.

PubMed

Saito, Mariko; Chakraborty, Goutam; Hui, Maria; Masiello, Kurt; Saito, Mitsuo

2016-08-16

Ethanol induces neurodegeneration in the developing brain, which may partially explain the long-lasting adverse effects of prenatal ethanol exposure in fetal alcohol spectrum disorders (FASD). While animal models of FASD show that ethanol-induced neurodegeneration is associated with glial activation, the relationship between glial activation and neurodegeneration has not been clarified. This review focuses on the roles of activated microglia and astrocytes in neurodegeneration triggered by ethanol in rodents during the early postnatal period (equivalent to the third trimester of human pregnancy). Previous literature indicates that acute binge-like ethanol exposure in postnatal day 7 (P7) mice induces apoptotic neurodegeneration, transient activation of microglia resulting in phagocytosis of degenerating neurons, and a prolonged increase in glial fibrillary acidic protein-positive astrocytes. In our present study, systemic administration of a moderate dose of lipopolysaccharides, which causes glial activation, attenuates ethanol-induced neurodegeneration. These studies suggest that activation of microglia and astrocytes by acute ethanol in the neonatal brain may provide neuroprotection. However, repeated or chronic ethanol can induce significant proinflammatory glial reaction and neurotoxicity. Further studies are necessary to elucidate whether acute or sustained glial activation caused by ethanol exposure in the developing brain can affect long-lasting cellular and behavioral abnormalities observed in the adult brain.

Endotoxicosis induced by Coxiella burnetii lipopolysaccharide stimulates a ribosomal protein S6 kinase: some properties of the partially purified enzyme.

PubMed Central

Picking, W D; Hackstadt, T; Paretsky, D

1989-01-01

Guinea pig endotoxicosis induced by lipopolysaccharide from Coxiella burnetii Nine Mile phase I stimulates phosphorylation of liver ribosomal protein S6, with a 50% increase at 12 h postinoculation. The responsible protein kinase (S6PK) has been partially purified from liver; its activity is independent of cyclic AMP and of Ca2+ plus phosphatidyl serine or diacylglycerol. The preparation has an apparent optimum concentration of 20 mM Mg2+, while Ca2+ and Mn2+ are each inhibitory at 2 mM. The apparent Km for ATP is 30 microM with intact ribosomes. Because of the central role of phosphorylation in metabolic regulation and a purported role of phosphorylated S6 in protein synthesis, the lipopolysaccharide-induced stimulation of S6PK suggests a significant regulatory role of such enzymes in the pathobiochemistry of Q fever infection and endotoxicosis. Images PMID:2807543

Lycium barbarum polysaccharide protects human keratinocytes against UVB-induced photo-damage.

PubMed

Li, Huaping; Li, Zhenjie; Peng, Liqian; Jiang, Na; Liu, Qing; Zhang, Erting; Liang, Bihua; Li, Runxiang; Zhu, Huilan

2017-02-01

Ultraviolet B (UVB) irradiation plays a key role in skin damage, which induces oxidative and inflammatory damages, thereby causing photoaging or photocarcinogenesis. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses significant antioxidative and anti-inflammatory effects on multiple tissues. In the present study, the photoprotective effects and potential underlying molecular mechanisms of LBP against UVB-induced photo-damage were investigated in immortalized human keratinocytes (HaCaT cells). The data indicated that pretreatment with LBP significantly attenuated UVB-induced decrease in cell viability, increase in ROS production and DNA damage. LBP also significantly suppressed UVB-induced p38 MAPK activation, and subsequently reversed caspase-3 activation and MMP-9 expression. Notably, LBP was found to induce Nrf2 nuclear translocation and increase the expression of Nrf2-dependent ARE target genes. Furthermore, the protective effects of LBP were abolished by siRNA-mediated Nrf2 silencing. These results showed that the antioxidant LBP could partially protect against UVB irradiation-induced photo-damage through activation of Nrf2/ARE pathway, thereby scavenging ROS and reducing DNA damage, and subsequently suppressing UVB-induced p38 MAP pathway. Thus, LBP can be potentially used for skincare against oxidative damage from environmental insults.

Macrophage activation induced by Brucella DNA suppresses bacterial intracellular replication via enhancing NO production.

PubMed

Liu, Ning; Wang, Lin; Sun, Changjiang; Yang, Li; Tang, Bin; Sun, Wanchun; Peng, Qisheng

2015-12-01

Brucella DNA can be sensed by TLR9 on endosomal membrane and by cytosolic AIM2-inflammasome to induce proinflammatory cytokine production that contributes to partially activate innate immunity. Additionally, Brucella DNA has been identified to be able to act as a major bacterial component to induce type I IFN. However, the role of Brucella DNA in Brucella intracellular growth remains unknown. Here, we showed that stimulation with Brucella DNA promote macrophage activation in TLR9-dependent manner. Activated macrophages can suppresses wild type Brucella intracellular replication at early stage of infection via enhancing NO production. We also reported that activated macrophage promotes bactericidal function of macrophages infected with VirB-deficient Brucella at the early or late stage of infection. This study uncovers a novel function of Brucella DNA, which can help us further elucidate the mechanism of Brucella intracellular survival. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antioxidant and mercury chelating activity of Psidium guajava var. pomifera L. leaves hydroalcoholic extract.

PubMed

Pinho, Antonio Ivanildo; Oliveira, Cláudia Sirlene; Lovato, Fabricio Luís; Waczuk, Emily Pansera; Piccoli, Bruna Candia; Boligon, Aline Augusti; Leite, Nadghia Figueredo; Coutinho, Henrique Douglas Melo; Posser, Thais; Da Rocha, João Batista Teixeira; Franco, Jeferson Luis

2017-01-01

Mercury (Hg) is widely distributed in the environment and is known to produce several adverse effects in organisms. The aim of the present study was to examine the in vitro antioxidant activity and Hg chelating ability of the hydroalcoholic extract of Psidium guajava leaves (HEPG). In addition, the potential protective effects of HEPG against Hg(II) were evaluated using a yeast model (Saccharomyces cerevisiae). HEPG was found to exert significant antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl scavenger and inhibition of lipid peroxidation induced by Fe(II) assays in a concentration-dependent manner. The extract also exhibited significant Hg(II) chelating activity. In yeast, Hg(II) induced a significant decrease in cell viability. In contrast, HEPG partially prevented the fall in cell viability induced by Hg(II). In conclusion, HEPG exhibited protective effects against Hg(II)-mediated toxicity, which may be related to both antioxidant and Hg(II)-chelating activities.

Ameliorating effects of fluorocarbon emulsion on sickle red blood cell-induced obstruction in an ex vivo vasculature.

PubMed

Kaul, D K; Liu, X; Nagel, R L

2001-11-15

In sickle cell (SS) vaso-occlusion, the culminating event is blockage of blood vessels by sickled red blood cells (SS RBCs). As shown in animal models, SS RBC-induced vaso-occlusion is often partial, allowing for a residual flow, hence oxygen delivery to partially occluded vessels could reduce vaso-occlusion. The efficacy of an oxygenated perflubron-based fluorocarbon emulsion (PFE) was tested for its anti-vaso-occlusive effects in the ex vivo mesocecum vasculature of the rat. Microvascular obstruction was induced by the infusion of deoxygenated SS RBCs into ex vivo preparations with or without pretreatment with platelet-activating factor (PAF). PAF induced enhanced SS RBC-endothelium interactions, leading to greater vaso-occlusion. Microvascular blockage resulted in increased peripheral resistance units (PRU). Deoxygenated SS RBCs caused a persistent 1.5-fold PRU increase in untreated preparations and approximately a 2-fold PRU increase in PAF-treated preparations. The greater PRU in PAF-treated preparations was caused by widespread adhesion and postcapillary blockage. Oxygenated PFE, but not deoxygenated PFE, resulted in PRU decreases to baseline values in both groups of experiments (with or without PAF). The PRU decrease caused by oxygenated PFE infusion was caused by unsickling of SS RBCs in partially occluded vessels, with no antiadhesive effect on already adherent SS RBCs as assessed by intravital microscopy. PFE had no effect on vascular tone. The efficacy of PFE appears to result from its greater capacity to dissolve oxygen (10-fold higher than plasma). The dislodgement of trapped SS RBCs and an increase in wall shear rates will help reverse the partial obstruction. Thus, oxygenated PFE is capable of reducing SS RBC-induced vaso-occlusion, and further development of this approach is advisable.

Event-Associated Oxygen Consumption Rate Increases ca. Five-Fold When Interictal Activity Transforms into Seizure-Like Events In Vitro.

PubMed

Schoknecht, Karl; Berndt, Nikolaus; Rösner, Jörg; Heinemann, Uwe; Dreier, Jens P; Kovács, Richard; Friedman, Alon; Liotta, Agustin

2017-09-07

Neuronal injury due to seizures may result from a mismatch of energy demand and adenosine triphosphate (ATP) synthesis. However, ATP demand and oxygen consumption rates have not been accurately determined, yet, for different patterns of epileptic activity, such as interictal and ictal events. We studied interictal-like and seizure-like epileptiform activity induced by the GABA A antagonist bicuculline alone, and with co-application of the M-current blocker XE-991, in rat hippocampal slices. Metabolic changes were investigated based on recording partial oxygen pressure, extracellular potassium concentration, and intracellular flavine adenine dinucleotide (FAD) redox potential. Recorded data were used to calculate oxygen consumption and relative ATP consumption rates, cellular ATP depletion, and changes in FAD/FADH₂ ratio by applying a reactive-diffusion and a two compartment metabolic model. Oxygen-consumption rates were ca. five times higher during seizure activity than interictal activity. Additionally, ATP consumption was higher during seizure activity (~94% above control) than interictal activity (~15% above control). Modeling of FAD transients based on partial pressure of oxygen recordings confirmed increased energy demand during both seizure and interictal activity and predicted actual FAD autofluorescence recordings, thereby validating the model. Quantifying metabolic alterations during epileptiform activity has translational relevance as it may help to understand the contribution of energy supply and demand mismatches to seizure-induced injury.

Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo

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

Franco, Gilson C.N.; Department of Pharmacology, FOP/UNICAMP, Piracicaba, SP; Kajiya, Mikihito

2011-06-10

Tetracycline antibiotics, including doxycycli/e (DOX), have been used to treat bone resorptive diseases, partially because of their activity to suppress osteoclastogenesis induced by receptor activator of nuclear factor kappa B ligand (RANKL). However, their precise inhibitory mechanism remains unclear. Therefore, the present study examined the effect of Dox on osteoclastogenesis signaling induced by RANKL, both in vitro and in vivo. Although Dox inhibited RANKL-induced osteoclastogenesis and down-modulated the mRNA expression of functional osteoclast markers, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, Dox neither affected RANKL-induced MAPKs phosphorylation nor NFATc1 gene expression in RAW264.7 murine monocytic cells. Gelatin zymography andmore » Western blot analyses showed that Dox down-regulated the enzyme activity of RANKL-induced MMP-9, but without affecting its protein expression. Furthermore, MMP-9 enzyme inhibitor also attenuated both RANKL-induced osteoclastogenesis and up-regulation of TRAP and cathepsin K mRNA expression, indicating that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclastogenesis. Finally, Dox treatment abrogated RANKL-induced osteoclastogenesis and TRAP activity in mouse calvaria along with the suppression of MMP9 enzyme activity, again without affecting the expression of MMP9 protein. These findings suggested that Dox inhibits RANKL-induced osteoclastogenesis by its inhibitory effect on MMP-9 enzyme activity independent of the MAPK-NFATc1 signaling cascade.« less

Protective effects of anti-ricin A-chain RNA aptamer against ricin toxicity

PubMed Central

Fan, Shaoan; Wu, Feng; Martiniuk, Frank; Hale, Martha L; Ellington, Andrew D; Tchou-Wong, Kam-Meng

2008-01-01

AIM: To investigate the therapeutic potential of an RNA ligand (aptamer) specific for the catalytic ricin A-chain (RTA), the protective effects of a 31-nucleotide RNA aptamer (31RA), which formed a high affinity complex with RTA, against ricin-induced toxicity in cell-based luciferase translation and cell cytotoxicity assays were evaluated. METHODS: To test the therapeutic potential of anti-RTA aptamers in Chinese hamster ovary (CHO) AA8 cells stably transfected with a tetracycline regulatable promoter, ricin ribotoxicity was measured using luciferase and ricin-induced cytotoxicity was ascertained by MTS cell proliferation assay with tetrazolium compound [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium]. RESULTS: Inhibition of protein synthesis by ricin in CHO AA8 cells resulted in diminished luciferase activity and treatment with polyclonal antibody against deglycosylated RTA (dgA) neutralized the inhibitory effects of ricin on luciferase activity and protected against ricin-induced cytotoxicity as measured by MTS assay. The 31RA anti-RTA aptamer inhibited the translation of luciferase mRNA in cell-free reticulocyte translation assay. 31RA aptamer also partially neutralized the inhibitory effects of ricin on luciferase activity and partially protected against ricin-induced cytotoxicity in CHO AA8 cells. CONCLUSION: We have shown that anti-RTA RNA aptamer can protect against ricin ribotoxicity in cell-based luciferase and cell cytotoxicity assays. Hence, RNA aptamer that inhibits RTA enzymatic activity represents a novel class of nucleic acid inhibitor that has the potential to be developed as a therapeutic agent for the treatment of ricin intoxication. PMID:19009652

Endothelium-dependent vasorelaxant effect of procyanidin B2 on human internal mammary artery.

PubMed

Novakovic, Aleksandra; Marinko, Marija; Jankovic, Goran; Stojanovic, Ivan; Milojevic, Predrag; Nenezic, Dragoslav; Kanjuh, Vladimir; Yang, Qin; He, Guo-Wei

2017-07-15

The aim of the present study was to investigate and characterize vasorelaxant effect of procyanidin B2 on human internal mammary artery (HIMA) as one of the mechanisms of its protective effect against vascular risk. Procyanidin B2 induced strong concentration-dependent relaxation of HIMA rings pre-contracted by phenylephrine. Pretreatment with L-NAME, a NO synthase inhibitor, hydroxocobalamin, a NO scavenger, and ODQ, an inhibitor of soluble guanylate cyclase, significantly inhibited procyanidin B2-induced relaxation of HIMA, while indomethacin, a cyclooxygenase inhibitor, considerably reduced effects of low concentrations. Among K + channel blockers, iberiotoxin, a selective blocker of large conductance Ca 2+ -activated K + channels (BK Ca ), abolished procyanidin B2-induced relaxation, glibenclamide, a selective ATP-sensitive K + (K ATP ) channels blocker, induced partial inhibition, while 4-aminopyridine, a blocker of voltage-gated K + (K V ) channels, and TRAM-34, an inhibitor of intermediate-conductance Ca 2+ -activated K + (IK Ca ) channels, slightly reduced maximal relaxation of HIMA. Further, procyanidin B2 relaxed contraction induced by phenylephrine in Ca 2+ -free Krebs solution, but had no effect on contraction induced by caffeine. Finally, thapsigargin, a sarcoplasmic reticulum Ca 2+ -ATPase inhibitor, significantly reduced relaxation of HIMA produced by procyanidin B2. These results demonstrate that procyanidin B2 produces endothelium-dependent relaxation of HIMA pre-contracted by phenylephrine. This effect is primarily the result of an increased NO synthesis and secretion by endothelial cells and partially of prostacyclin, although it involves activation of BK Ca and K ATP , as well as K V and IK Ca channels in high concentrations of procyanidin B2. Copyright © 2017 Elsevier B.V. All rights reserved.

A Partial E3 Deletion in Replication-Defective Adenoviral Vectors Allows for Stable Expression of Potentially Toxic Transgene Products.

PubMed

Haut, Larissa H; Gill, Amanda L; Kurupati, Raj K; Bian, Ang; Li, Yan; Giles-Davis, Wynetta; Xiang, Zhiquan; Zhou, Xiang Yang; Ertl, Hildegund C J

2016-10-01

Adenovirus (Ad) is used extensively for construction of viral vectors, most commonly with deletion in its E1 and/or E3 genomic regions. Previously, our attempts to insert envelope proteins (Env) of HIV-1 into such vectors based on chimpanzee-derived Ad (AdC) viruses were thwarted. Here, we describe that genetic instability of an E1- and E3-deleted AdC vector of serotype C6 expressing Env of HIV-1 can be overcome by reinsertion of E3 sequences with anti-apoptotic activities. This partial E3 deletion presumably delays premature death of HEK-293 packaging cell lines due to Env-induced cell apoptosis. The same partial E3 deletion also allows for the generation of stable glycoprotein 140 (gp140)- and gp160-expressing Ad vectors based on AdC7, a distinct AdC serotype. Env-expressing AdC vectors containing the partial E3 deletion are genetically stable upon serial cell culture passaging, produce yields comparable to those of other AdC vectors, and induce transgene product-specific antibody responses in mice. A partial E3 deletion thereby allows expansion of the repertoire of transgenes that can be expressed by Ad vectors.

The integrin-binding motif RGDS induces protein tyrosine phosphorylation without activation in Bufo arenarum (Amphibia) oocytes.

PubMed

Mouguelar, Valeria S; Cabada, Marcelo O; Coux, Gabriela

2011-05-01

Integrins are cell adhesion molecules that are thought to be involved in sperm-oocyte interaction. Nevertheless, their function in mammalian fertilization is still controversial, as different species behave differently. In amphibians, their role is mainly supported by Xenopus laevis studies, where RGDS peptide induces oocyte activation. We recently provided evidence suggesting the presence and involvement of integrins in the interaction of the oocyte plasma membrane (PM) with sperm in the amphibian Bufo arenarum. In order to understand the role of integrin homologs in oocytes and their possible contribution to egg activation mechanisms, we examined the presence of integrin subunits and the effect of RGDS peptide on oocytes and during fertilization. Western blot studies detected integrin subunits α5, αV and β1 in oocytes. In sperm, we could detect only the αV integrin subunit. We found that RGDS peptide was unable to elicit egg activation or MAPK dephosphorylation, but can induce reversible inhibition of fertilization. A similar partial inhibition was produced by an anti-β1 integrin antibody. Using an anti-phosphotyrosine antibody we found major changes in phosphotyrosine-containing proteins in egg extracts minutes after fertilization. Cytosol and PMs isolated from oocytes and fertilized eggs showed additional fertilization-induced phosphorylated proteins. Some of these were also present in cytosol and PMs from RGDS-treated oocytes (partially mimicking fertilization). These findings suggest that B. arenarum fertilization involves integrins (e.g. β1 subunit) as adhesion proteins. Our data support the view that RGDS-binding receptors may function as signaling receptors in B. arenarum oocytes, but integrin engagement by RGDS is not sufficient for oocyte activation.

Identification of a Raloxifene Analog That Promotes AhR-Mediated Apoptosis in Cancer Cells.

PubMed

Jang, Hyo Sang; Pearce, Martin; O'Donnell, Edmond F; Nguyen, Bach Duc; Truong, Lisa; Mueller, Monica J; Bisson, William H; Kerkvliet, Nancy I; Tanguay, Robert L; Kolluri, Siva Kumar

2017-12-01

We previously reported that raloxifene, an estrogen receptor modulator, is also a ligand for the aryl hydrocarbon receptor (AhR). Raloxifene induces apoptosis in estrogen receptor-negative human cancer cells through the AhR. We performed structure-activity studies with seven raloxifene analogs to better understand the structural requirements of raloxifene for induction of AhR-mediated transcriptional activity and apoptosis. We identified Y134 as a raloxifene analog that activates AhR-mediated transcriptional activity and induces apoptosis in MDA-MB-231 human triple negative breast cancer cells. Suppression of AhR expression strongly reduced apoptosis induced by Y134, indicating the requirement of AhR for Y134-induced apoptosis. Y134 also induced apoptosis in hepatoma cells without having an effect on cell cycle regulation. Toxicity testing on zebrafish embryos revealed that Y134 has a significantly better safety profile than raloxifene. Our studies also identified an analog of raloxifene that acts as a partial antagonist of the AhR, and is capable of inhibiting AhR agonist-induced transcriptional activity. We conclude that Y134 is a promising raloxifene analog for further optimization as an anti-cancer agent targeting the AhR.

AM fungal exudates activate MAP kinases in plant cells in dependence from cytosolic Ca(2+) increase.

PubMed

Francia, Doriana; Chiltz, Annick; Lo Schiavo, Fiorella; Pugin, Alain; Bonfante, Paola; Cardinale, Francesca

2011-09-01

The molecular dialogue occurring prior to direct contact between the fungal and plant partners of arbuscular-mycorrhizal (AM) symbioses begins with the release of fungal elicitors, so far only partially identified chemically, which can activate specific signaling pathways in the host plant. We show here that the activation of MAPK is also induced by exudates of germinating spores of Gigaspora margarita in cultured cells of the non-leguminous species tobacco (Nicotiana tabacum), as well as in those of the model legume Lotus japonicus. MAPK activity peaked about 15 min after the exposure of the host cells to the fungal exudates (FE). FE were also responsible for a rapid and transient increase in free cytosolic Ca(2+) in Nicotiana plumbaginifolia and tobacco cells, and pre-treatment with a Ca(2+)-channel blocker (La(3+)) showed that in these cells, MAPK activation was dependent on the cytosolic Ca(2+) increase. A partial dependence of MAPK activity on the common Sym pathway could be demonstrated for a cell line of L. japonicus defective for LjSym4 and hence unable to establish an AM symbiosis. Our results show that MAPK activation is triggered by an FE-induced cytosolic Ca(2+) transient, and that a Sym genetic determinant acts to modulate the intensity and duration of this activity. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Reorganization of motor cortex and impairment of motor performance induced by hindlimb unloading are partially reversed by cortical IGF-1 administration.

PubMed

Mysoet, Julien; Canu, Marie-Hélène; Gillet, Christophe; Fourneau, Julie; Garnier, Cyril; Bastide, Bruno; Dupont, Erwan

2017-01-15

Immobilization, bed rest, or sedentary lifestyle, are known to induce a profound impairment in sensorimotor performance. These alterations are due to a combination of peripheral and central factors. Previous data conducted on a rat model of disuse (hindlimb unloading, HU) have shown a profound reorganization of motor cortex and an impairment of motor performance. Recently, our interest was turned towards the role of insulin-like growth factor 1 (IGF-1) in cerebral plasticity since this growth factor is considered as the mediator of beneficial effects of exercise on the central nervous system, and its cortical level is decreased after a 14-day period of HU. In the present study, we attempted to determine whether a chronic subdural administration of IGF-1 in HU rats could prevent deleterious effects of HU on the motor cortex and on motor activity. We demonstrated that HU induces a shrinkage of hindlimb cortical representation and an increase in current threshold to elicit a movement. Administration of IGF-1 in HU rats partially reversed these changes. The functional evaluation revealed that IGF-1 prevents the decrease in spontaneous activity found in HU rats and the changes in hip kinematics during overground locomotion, but had no effect of challenged locomotion (ladder rung walking test). Taken together, these data clearly indicate the implication of IGF-1 in cortical plastic mechanisms and in behavioral alteration induced by a decreased in sensorimotor activity. Copyright © 2016 Elsevier B.V. All rights reserved.

Elevation of GM2 ganglioside during ethanol-induced apoptotic neurodegeneration in the developing mouse brain.

PubMed

Saito, Mitsuo; Chakraborty, Goutam; Shah, Relish; Mao, Rui-Fen; Kumar, Asok; Yang, Dun-Sheng; Dobrenis, Kostantin; Saito, Mariko

2012-05-01

GM2 ganglioside in the brain increased during ethanol-induced acute apoptotic neurodegeneration in 7-day-old mice. A small but a significant increase observed 2 h after ethanol exposure was followed by a marked increase around 24 h. Subcellular fractionation of the brain 24 h after ethanol treatment indicated that GM2 increased in synaptic and non-synaptic mitochondrial fractions as well as in a lysosome-enriched fraction characteristic to the ethanol-exposed brain. Immunohistochemical staining of GM2 in the ethanol-treated brain showed strong punctate staining mainly in activated microglia, in which it partially overlapped with staining for LAMP1, a late endosomal/lysosomal marker. Also, there was weaker neuronal staining, which partially co-localized with complex IV, a mitochondrial marker, and was augmented in cleaved caspase 3-positive neurons. In contrast, the control brain showed only faint and diffuse GM2 staining in neurons. Incubation of isolated brain mitochondria with GM2 in vitro induced cytochrome c release in a manner similar to that of GD3 ganglioside. Because ethanol is known to trigger mitochondria-mediated apoptosis with cytochrome c release and caspase 3 activation in the 7-day-old mouse brain, the GM2 elevation in mitochondria may be relevant to neuroapoptosis. Subsequently, activated microglia accumulated GM2, indicating a close relationship between GM2 and ethanol-induced neurodegeneration. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Association of Physical and Technical Activities With Partial Match Status in a Soccer Professional Team.

PubMed

Moalla, Wassim; Fessi, Mohamed Saieffedin; Makni, Emna; Dellal, Alexandre; Filetti, Cristoforo; Di Salvo, Valter; Chamari, Karim

2018-06-01

Moalla, W, Fessi, MS, Makni, E, Dellal, A, Filetti, C, Di Salvo, V, and Chamari, K. Association of physical and technical activities with partial match status in a soccer professional team. J Strength Cond Res 32(6): 1708-1714, 2018-The purpose of this study was to examine the association between physical and technical activities and partial match status (winning, drawing, or losing) in a professional soccer team over 2 seasons. Physical and technical activities of 52 official matches were collected and analyzed at each 15-minute interval, for each half (45 minutes), and full match (90 minutes) using a multiple-camera computerized tracking system. The results indicated that according to full match outcome: winning status was characterized by players covering more total distance (p ≤ 0.05) and low-intensity running (<14.4 km·h) (p ≤ 0.05), whereas, losing status induced more sprinting (≥25.2 km·h) (p < 0.01) and high-intensity running (≥19.8 km·h) (p ≤ 0.05). However, according to partial match status (i.e., 15 minutes and half time), players covered more distance for all running intensities while winning (p < 0.01). Technical match performance scores were not influenced by match status. In conclusion, the present study showed that the physical activities including high-intensity running and total distance covered were related to the match status, whereas technical activities were not. The overall outcome shows that higher physical activity was associated with winning partial match periods. This approach highlights the importance of physical fitness in soccer and may help coaches to better modulate players' roles and team tactical organization throughout the match.

Movement Disorders Induced by the "Atypical" Antipsychotic Aripiprazole.

PubMed

Selfani, Karim; Soland, Valérie L; Chouinard, Sylvain; Huot, Philippe

2017-01-01

Aripiprazole is an antipsychotic that acts as a partial agonist at dopamine D2 receptors. Because of its partial agonist activity, it was believed that aripiprazole would be less susceptible than typical antipsychotics to induce extrapyramidal side effects. However, a few case-reports and case-series detailing aripiprazole-induced movement disorders have been published, suggesting that aripiprazole-induced movement disorders may arise. Here, we seek to report further cases of aripiprazole-induced movement disorders to raise the awareness of clinicians on this adverse effect. Patients referred to the André-Barbeau Movement Disorder clinic treated with aripiprazole were enrolled in this study. Their charts were retrospectively reviewed and data regarding past psychiatric history, past antipsychotic medication, duration of aripiprazole treatment, daily dose of aripiprazole administered, and resulting movement disorders were collected. We report 14 cases of parkinsonism, tardive dyskinesia and akathisia induced by aripiprazole. Some of these, mostly the parkinsonian phenotype, abated spontaneously following drug discontinuation, whereas others, mostly related to tardive phenomena, persisted after aripiprazole was discontinued, and required treatment. This case-series adds to the existing literature that suggests that movement disorders may arise following treatment with aripiprazole. Clinicians should be aware of this potential side effect when prescribing aripiprazole to patients.

The osmotic shock-induced glucose transport pathway in 3T3-L1 adipocytes is mediated by gab-1 and requires Gab-1-associated phosphatidylinositol 3-kinase activity for full activation.

PubMed

Janez, A; Worrall, D S; Imamura, T; Sharma, P M; Olefsky, J M

2000-09-01

Osmotic shock treatment of 3T3-L1 adipocytes causes an increase in glucose transport activity and translocation of GLUT4 protein similar to that elicited by insulin treatment. Insulin stimulation of GLUT4 translocation and glucose transport activity was completely inhibited by wortmannin, however, activation by osmotic shock was only partially blocked. Additionally, we have found that the newly identified insulin receptor substrate Gab-1 (Grb2-associated binder-1) is tyrosine-phosphorylated following sorbitol stimulation. Treatment of cells with the tyrosine kinase inhibitor genistein inhibited osmotic shock-stimulated Gab-1 phosphorylation as well as shock-induced glucose transport. Furthermore, pretreatment with the selective Src family kinase inhibitor PP2 completely inhibited the ability of sorbitol treatment to cause tyrosine phosphorylation of Gab-1. We have also shown that microinjection of anti-Gab-1 antibody inhibits osmotic shock-induced GLUT4 translocation. Furthermore, phosphorylated Gab-1 binds and activates phosphatidylinositol 3-kinase (PI3K) in response to osmotic shock. The PI3K activity associated with Gab-1 was 82% of that associated with anti-phosphotyrosine antibodies, indicating that Gab-1 is the major site for PI3K recruitment following osmotic shock stimulation. Although wortmannin only causes a partial block of osmotic shock-stimulated glucose uptake, wortmannin completely abolishes Gab-1 associated PI3K activity. This suggests that other tyrosine kinase-dependent pathways, in addition to the Gab-1-PI3K pathway, contribute to osmotic shock-mediated glucose transport. To date, Gab-1 is the first protein identified as a member of the osmotic shock signal transduction pathway.

Enhancement of synaptic transmission induced by BDNF in cultured cortical neurons

NASA Astrophysics Data System (ADS)

He, Jun; Gong, Hui; Zeng, Shaoqun; Li, Yanling; Luo, Qingming

2005-03-01

Brain-derived neurotrophic factor (BDNF), like other neurotrophins, has long-term effects on neuronal survival and differentiation; furthermore, BDNF has been reported to exert an acute potentiation of synaptic activity and are critically involved in long-term potentiation (LTP). We found that BDNF rapidly induced potentiation of synaptic activity and an increase in the intracellular Ca2+ concentration in cultured cortical neurons. Within minutes of BDNF application to cultured cortical neurons, spontaneous firing rate was dramatically increased as were the frequency and amplitude of excitatory spontaneous postsynaptic currents (EPSCs). Fura-2 recordings showed that BDNF acutely elicited an increase in intracellular calcium concentration ([Ca2+]c). This effect was partially dependent on [Ca2+]o; The BDNF-induced increase in [Ca2+]c can not be completely blocked by Ca2+-free solution. It was completely blocked by K252a and partially blocked by Cd2+ and TTX. The results demonstrate that BDNF can enhances synaptic transmission and that this effect is accompanied by a rise in [Ca2+]c that requires two route: the release of Ca2+ from intracellular calcium stores and influx of extracellular Ca2+ through voltage-dependent Ca2+ channels in cultured cortical neurons.

F15063, a compound with D2/D3 antagonist, 5-HT1A agonist and D4 partial agonist properties: (II) Activity in models of positive symptoms of schizophrenia

PubMed Central

Depoortère, R; Bardin, L; Auclair, A L; Kleven, M S; Prinssen, E; Colpaert, F; Vacher, B; Newman-Tancredi, A

2007-01-01

Background and purpose: F15063 is a high affinity D2/D3 antagonist, D4 partial agonist, and high efficacy 5-HT1A agonist, with little affinity (40-fold lower than for D2 receptors) at other central targets. Here, the profile of F15063 was evaluated in models of positive symptoms of schizophrenia and motor side-effects. Experimental approach: Rodent behavioural tests were based on reversal of hyperactivity induced by psychostimulants and on measures of induction of catalepsy and ‘serotonin syndrome'. Key results: F15063 potently (ED50s: 0.23 to 1.10 mg kg−1 i.p.) reversed methylphenidate-induced stereotyped behaviors, blocked d-amphetamine and ketamine hyperlocomotion, attenuated apomorphine-induced prepulse inhibition (PPI) deficits, and was active in the conditioned avoidance test. In mice, it reversed apomorphine-induced climbing (ED50 = 0.30 mg kg−1 i.p.). F15063, owing to its 5-HT1A agonism, did not produce (ED50 > 40 mg kg−1 i.p.) catalepsy in rats and mice, a behavior predictive of occurrence of extra-pyramidal syndrome (EPS) in man. This absence of cataleptogenic activity was maintained upon sub-chronic treatment of rats for 5 days at 40 mg kg−1 p.o. Furthermore, F15063 did not induce the ‘serotonin syndrome' in rats (flat body posture and forepaw treading: ED50 >32 mg kg−1 i.p.). Conclusions and implications: F15063 conformed to the profile of an atypical antipsychotic, with potent actions in models of hyperdopaminergic activity but without inducing catalepsy. These data suggest that F15063 may display potent antipsychotic actions with low EPS liability. This profile is complemented by a favourable profile in rodent models of negative symptoms and cognitive deficits of schizophrenia (companion paper). PMID:17375086

Tissue factor-dependent coagulation activation by heme: A thromboelastometry study.

PubMed

de Souza, Gleice Regina; Hounkpe, Bidossessi Wilfried; Fiusa, Maiara Marx Luz; Colella, Marina Pereira; Annichino-Bizzacchi, Joyce M; Traina, Fabiola; Costa, Fernando Ferreira; De Paula, Erich Vinicius

2017-01-01

Heme has been characterized as potent trigger of inflammation. In hemostasis, although heme has been shown to both induce and inhibit different compartments of hemostasis, its net effect on the hemostatic balance, and the biological relevance of these effects remain to be determined. Herein we evaluated the effect of heme on hemostasis using a global assay able to generate clinically relevant data in several other complex hemostatic diseases. Citrated whole blood samples from healthy participants were stimulated by heme or vehicle and incubated for 4h at 37°C. Rotational thromboelastometry was immediately performed. The participation of tissue factor in coagulation activation was evaluated using inhibitory antibody. Heme was able of inducing ex vivo coagulation activation in whole blood, affecting predominantly parameters associated with the initial phases of clot formation. This activation effect was at least partially dependent on hematopoietic tissue factor, since the effects of heme were partially abrogated by the inhibition of human tissue factor. In conclusion, using a global hemostasis assay, our study confirmed that heme is able to activate coagulation in whole blood, in a tissue factor-dependent way. These findings could explain the disturbance in hemostatic balance observed in conditions associated with the release of heme such as sickle cell disease.

Telmisartan, a possible PPAR-δ agonist, reduces TNF-α-stimulated VEGF-C production by inhibiting the p38MAPK/HSP27 pathway in human proximal renal tubular cells

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

Kimura, Hideki, E-mail: hkimura@u-fukui.ac.jp; Department of Clinical Laboratories and Nephrology, University of Fukui Hospital, Fukui; Mikami, Daisuke

Highlights: • TNF-α increased VEGF-C expression by enhancing phosphorylation of p38MAPK and HSP27. • Telmisartan decreased TNF-α-stimulated expression of VEGF-C. • Telmisartan suppressed TNF-α-induced phosphorylation of p38MAPK and HSP27. • Telmisartan activated endogenous PPAR-δ protein. • Telmisartan suppressed p38MAPK phosphorylation in a PPAR-δ-dependent manner. - Abstract: Vascular endothelial growth factor-C (VEGF-C) is a main inducer of inflammation-associated lymphangiogenesis in various inflammatory disorders including chronic progressive kidney diseases, for which angiotensin II receptor type 1 blockers (ARBs) are widely used as the main treatment. Although proximal renal tubular cells may affect the formation of lymphatic vessels in the interstitial area bymore » producing VEGF-C, the molecular mechanisms of VEGF-C production and its manipulation by ARB have not yet been examined in human proximal renal tubular epithelial cells (HPTECs). In the present study, TNF-α dose-dependently induced the production of VEGF-C in HPTECs. The TNF-α-induced production of VEGF-C was mediated by the phosphorylation of p38MAPK and HSP27, but not by that of ERK or NFkB. Telmisartan, an ARB that can activate the peroxisome proliferator-activated receptor (PPAR), served as a PPAR-δ activator and reduced the TNF-α-stimulated production of VEGF-C. This reduction was partially attributed to a PPAR-δ-dependent decrease in p38MAPK phosphorylation. Our results indicate that TNF-α induced the production of VEGF-C in HPTECs by activating p38MAPK/HSP27, and this was partially inhibited by telmisartan in a PPAR-δ dependent manner. These results provide a novel insight into inflammation-associated lymphangiogenesis.« less

Vitamin K2-enhanced liver regeneration is associated with oval cell expansion and up-regulation of matrilin-2 expression in 2-AAF/PH rat model.

PubMed

Lin, M; Sun, P; Zhang, G; Xu, X; Liu, G; Miao, H; Yang, Y; Xu, H; Zhang, L; Wu, P; Li, M

2014-03-01

Normal liver has a great potential of regenerative capacity after partial hepatectomy. In clinic, however, most patients receiving partial hepatectomy are usually suffering from chronic liver diseases with severely damaged hepatocyte population. Under these conditions, activation of hepatic progenitor cell (oval cell in rodents) population might be considered as an alternative mean to enhance liver functional recovery. Vitamin K2 has been shown to promote liver functional recovery in patients with liver cirrhosis. In this study, we explored the possibility of vitamin K2 treatment in activating hepatic oval cell for liver regeneration with the classic 2-acetamido-fluorene/partial hepatectomy (2-AAF/PH) model in Sprague-Dawley rats. In 2-AAF/PH animals, vitamin K2 treatment induced a dose-dependent increase of liver regeneration as assessed by the weight ratio of remnant liver versus whole body and by measuring serum albumin level. In parallel, a drastic expansion of oval cell population as assessed by anti-OV6 and anti-CK19 immunostaining was noticed in the periportal zone of the remnant liver. Since matrilin-2 was linked to oval cell proliferation and liver regeneration after partial hepatectomy, we assessed its expression at both the mRNA and protein levels. The results revealed a significant increase after vitamin K2 treatment in parallel with the expansion of oval cell population. Consistently, knocking down matrilin-2 expression in vivo largely reduced vitamin K2-induced liver regeneration and oval cell proliferation in 2-AAF/PH animals. In conclusion, these data suggest that vitamin K2 treatment enhances liver regeneration after partial hepatectomy, which is associated with oval cell expansion and matrilin-2 up-regulation.

Thalidomide suppresses NF-kappa B activation induced by TNF and H2O2, but not that activated by ceramide, lipopolysaccharides, or phorbol ester.

PubMed

Majumdar, Sekhar; Lamothe, Betty; Aggarwal, Bharat B

2002-03-15

Thalidomide ([+]-alpha-phthalimidoglutarimide), a psychoactive drug that readily crosses the blood-brain barrier, has been shown to exhibit anti-inflammatory, antiangiogenic, and immunosuppressive properties through a mechanism that is not fully established. Due to the central role of NF-kappaB in these responses, we postulated that thalidomide mediates its effects through suppression of NF-kappaB activation. We investigated the effects of thalidomide on NF-kappaB activation induced by various inflammatory agents in Jurkat cells. The treatment of these cells with thalidomide suppressed TNF-induced NF-kappaB activation, with optimum effect occurring at 50 microg/ml thalidomide. These effects were not restricted to T cells, as other hematopoietic and epithelial cell types were also inhibited. Thalidomide suppressed H(2)O(2)-induced NF-kappaB activation but had no effect on NF-kappaB activation induced by PMA, LPS, okadaic acid, or ceramide, suggesting selectivity in suppression of NF-kappaB. The suppression of TNF-induced NF-kappaB activation by thalidomide correlated with partial inhibition of TNF-induced degradation of an inhibitory subunit of NF-kappaB (IkappaBalpha), abrogation of IkappaBalpha kinase activation, and inhibition of NF-kappaB-dependent reporter gene expression. Thalidomide abolished the NF-kappaB-dependent reporter gene expression activated by overexpression of TNFR1, TNFR-associated factor-2, and NF-kappaB-inducing kinase, but not that activated by the p65 subunit of NF-kappaB. Overall, our results clearly demonstrate that thalidomide suppresses NF-kappaB activation specifically induced by TNF and H(2)O(2) and that this may contribute to its role in suppression of proliferation, inflammation, angiogenesis, and the immune system.

Hexafluoroisopropanol-induced helix-sheet transition of stem bromelain: correlation to function.

PubMed

Dave, Sandeep; Dkhar, H Kitdorlang; Singh, Manvendra Pratap; Gupta, Garima; Chandra, Vemika; Mahajan, Sahil; Gupta, Pawan

2010-06-01

Stem bromelain is a proteolytic phytoprotein with a variety of therapeutic effects. Understanding its structural properties could provide insight into the mechanisms underlying its clinical utility. Stem bromelain was evaluated for its conformational and folding properties at the pH conditions it encounters when administered orally. It exists as a partially folded intermediate at pH 2.0. The conformational changes to this intermediate state were evaluated using fluorinated alcohols known to induce changes similar to those seen in vivo. Studies using circular dichroism, fluorescence emission spectroscopy, binding of the hydrophobic dye 1-anilino-8-naphthalene sulfonic acid and mass spectrometry indicate that treatment with 10-30% hexafluoroisopropanol induces the partially folded intermediate to adopt much of the native protein's secondary structure, but only a rudimentary tertiary structure, characteristic of the molten globule state. Addition of slightly higher concentrations of hexafluoroisopropanol caused transformation from an alpha-helix to a beta-sheet and induced formation of a compact nonnative structure. This nonnative form was more inhibitory of cell survival than either the native or the partially folded intermediate forms, as measured by enhanced suppression of proliferative cues (e.g., extracellular-signal-regulated kinase) and initiation of apoptotic events. The nonnative form also showed better antitumorigenic properties, as evaluated using an induced two-stage mouse skin papilloma model. In contrast, the nonnative state showed only a fraction of the proteolytic activity of the native form. This study demonstrates that hexafluoroisopropanol can induce a conformational change in stem bromelain to a form with potentially useful therapeutic properties different from those of the native protein. Copyright 2010 Elsevier Ltd. All rights reserved.

Restorative Effects of Uridine Plus Docosahexaenoic Acid in a Rat Model of Parkinson’s Disease

PubMed Central

Cansev, Mehmet; Ulus, Ismail H.; Wang, Lei; Maher, Timothy J.; Wurtman, Richard J.

2008-01-01

Summary Administering uridine-5’-monophosphate (UMP) and docosahexaenoic acid (DHA) increases synaptic membranes (as characterized by pre-and post-synaptic proteins) and dendritic spines in rodents. We examined their effects on rotational behavior and dopaminergic markers in rats with partial unilateral 6-hydroxydopamine (6-OHDA)-induced striatal lesions. Rats receiving UMP, DHA, both, or neither, daily, and intrastriatal 6-OHDA 3 days after treatment onset, were tested for d-amphetamine-induced rotational behavior and dopaminergic markers after 24 and 28 days, respectively. UMP/DHA treatment reduced ipsilateral rotations by 57% and significantly elevated striatal dopamine, tyrosine hydroxylase (TH) activity, TH protein and Synapsin-1 on the lesioned side. Hence, giving uridine and DHA may partially restore dopaminergic neurotransmission in this model of Parkinson’s Disease. PMID:18761383

Restorative effects of uridine plus docosahexaenoic acid in a rat model of Parkinson's disease.

PubMed

Cansev, Mehmet; Ulus, Ismail H; Wang, Lei; Maher, Timothy J; Wurtman, Richard J

2008-11-01

Administering uridine-5'-monophosphate (UMP) and docosahexaenoic acid (DHA) increases synaptic membranes (as characterized by pre- and post-synaptic proteins) and dendritic spines in rodents. We examined their effects on rotational behavior and dopaminergic markers in rats with partial unilateral 6-hydroxydopamine (6-OHDA)-induced striatal lesions. Rats receiving UMP, DHA, both, or neither, daily, and intrastriatal 6-OHDA 3 days after treatment onset, were tested for d-amphetamine-induced rotational behavior and dopaminergic markers after 24 and 28 days, respectively. UMP/DHA treatment reduced ipsilateral rotations by 57% and significantly elevated striatal dopamine, tyrosine hydroxylase (TH) activity, TH protein and synapsin-1 on the lesioned side. Hence, giving uridine and DHA may partially restore dopaminergic neurotransmission in this model of Parkinson's disease.

Kynurenic Acid Prevents Cytoskeletal Disorganization Induced by Quinolinic Acid in Mixed Cultures of Rat Striatum.

PubMed

Pierozan, Paula; Biasibetti-Brendler, Helena; Schmitz, Felipe; Ferreira, Fernanda; Pessoa-Pureur, Regina; Wyse, Angela T S

2018-06-01

Kynurenic acid (KYNA) is a neuroactive metabolite of tryptophan known to modulate a number of mechanisms involved in neural dysfunction. Although its activity in the brain has been widely studied, the effect of KYNA counteracting the actions of quinolinic acid (QUIN) remains unknown. The present study aims at describing the ability of 100 μM KYNA preventing cytoskeletal disruption provoked by QUIN in astrocyte/neuron/microglia mixed culture. KYNA totally preserved cytoskeletal organization, cell morphology, and redox imbalance in mixed cultures exposed to QUIN. However, KYNA partially prevented morphological alteration in isolated primary astrocytes and failed to protect the morphological alterations of neurons caused by QUIN exposure. Moreover, KYNA prevented QUIN-induced microglial activation and upregulation of ionized calcium-binding adapter molecule 1 (Iba-1) and partially preserved tumor necrosis factor-α (TNF-α) level in mixed cultures. TNF-α level was also partially preserved in astrocytes. In addition to the mechanisms dependent on redox imbalance and microglial activation, KYNA prevented downregulation of connexin-43 and the loss of functionality of gap junctions (GJs), preserving cell-cell contact, cytoskeletal organization, and cell morphology in QUIN-treated cells. Furthermore, the toxicity of QUIN targeting the cytoskeleton of mixed cultures was not prevented by the N-methyl-D-aspartate (NMDA) antagonist MK-801. We suggest that KYNA protects the integrity of the cytoskeleton of mixed cultures by complex mechanisms including modulating microglial activation preventing oxidative imbalance and misregulated GJs leading to disrupted cytoskeleton in QUIN-treated cells. This study contributed to elucidate the molecular basis of KYNA protection against QUIN toxicity.

Inhibition of autophagy enhances Hydroquinone-induced TK6 cell death.

PubMed

Xu, Longmei; Liu, Jiaxian; Chen, Yuting; Yun, Lin; Chen, Shaoyun; Zhou, Kairu; Lai, Bei; Song, Li; Yang, Hui; Liang, Hairong; Tang, Huanwen

2017-06-01

Hydroquinone (HQ), one of the metabolic products of benzene, is a carcinogen. It can induce apoptosis in lymphoma cells. However, whether HQ can induce autophagy and what roles autophagy plays in TK6 cells exposured to HQ remains unclear. In this study, we found that HQ could induce autophagy through techniques of qRT-PCR, Western blot, immunofluorescent assay of LC3 and transmission electron microscope. Furthermore, inhibiting autophagy using 3-methyladenine (3-MA) or chloroquine (CQ) significantly enhanced HQ-induced cell apoptosis, suggesting that autophagy may be a survival mechanism. Our study also showed that HQ activated PARP-1. Moreover, knockdown of PARP-1 strongly exhibited decreased autophagy related genes expression. In contrast, the absence of SIRT1 increased that. Altogether, our data provided evidence that HQ induced autophagy in TK6 cells and autophagy protected TK6 from HQ attack-induced injury in vitro, and the autophagy was partially mediated via activation of the PARP-1-SIRT1 signaling pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

PGC-1α-Dependent Mitochondrial Adaptation Is Necessary to Sustain IL-2-Induced Activities in Human NK Cells

PubMed Central

Jara, Claudia; Ibañez, Jorge; Ahumada, Viviana; Acuña-Castillo, Claudio; Martin, Adrian; Córdova, Alexandra

2016-01-01

Human Natural Killer (NK) cells are a specialized heterogeneous subpopulation of lymphocytes involved in antitumor defense reactions. NK cell effector functions are critically dependent on cytokines and metabolic activity. Among various cytokines modulating NK cell function, interleukin-2 (IL-2) can induce a more potent cytotoxic activity defined as lymphokine activated killer activity (LAK). Our aim was to determine if IL-2 induces changes at the mitochondrial level in NK cells to support the bioenergetic demand for performing this enhanced cytotoxic activity more efficiently. Purified human NK cells were cultured with high IL-2 concentrations to develop LAK activity, which was assessed by the ability of NK cells to lyse NK-resistant Daudi cells. Here we show that, after 72 h of culture of purified human NK cells with enough IL-2 to induce LAK activity, both the mitochondrial mass and the mitochondrial membrane potential increased in a PGC-1α-dependent manner. In addition, oligomycin, an inhibitor of ATP synthase, inhibited IL-2-induced LAK activity at 48 and 72 h of culture. Moreover, the secretion of IFN-γ from NK cells with LAK activity was also partially dependent on PGC-1α expression. These results indicate that PGC-1α plays a crucial role in regulating mitochondrial function involved in the maintenance of LAK activity in human NK cells stimulated with IL-2. PMID:27413259

PGC-1α-Dependent Mitochondrial Adaptation Is Necessary to Sustain IL-2-Induced Activities in Human NK Cells.

PubMed

Miranda, Dante; Jara, Claudia; Ibañez, Jorge; Ahumada, Viviana; Acuña-Castillo, Claudio; Martin, Adrian; Córdova, Alexandra; Montoya, Margarita

2016-01-01

Human Natural Killer (NK) cells are a specialized heterogeneous subpopulation of lymphocytes involved in antitumor defense reactions. NK cell effector functions are critically dependent on cytokines and metabolic activity. Among various cytokines modulating NK cell function, interleukin-2 (IL-2) can induce a more potent cytotoxic activity defined as lymphokine activated killer activity (LAK). Our aim was to determine if IL-2 induces changes at the mitochondrial level in NK cells to support the bioenergetic demand for performing this enhanced cytotoxic activity more efficiently. Purified human NK cells were cultured with high IL-2 concentrations to develop LAK activity, which was assessed by the ability of NK cells to lyse NK-resistant Daudi cells. Here we show that, after 72 h of culture of purified human NK cells with enough IL-2 to induce LAK activity, both the mitochondrial mass and the mitochondrial membrane potential increased in a PGC-1α-dependent manner. In addition, oligomycin, an inhibitor of ATP synthase, inhibited IL-2-induced LAK activity at 48 and 72 h of culture. Moreover, the secretion of IFN-γ from NK cells with LAK activity was also partially dependent on PGC-1α expression. These results indicate that PGC-1α plays a crucial role in regulating mitochondrial function involved in the maintenance of LAK activity in human NK cells stimulated with IL-2.

Methylglyoxal induces tau hyperphosphorylation via promoting AGEs formation.

PubMed

Li, Xiao-Hong; Xie, Jia-Zhao; Jiang, Xia; Lv, Bing-Ling; Cheng, Xiang-Shu; Du, Lai-Ling; Zhang, Jia-Yu; Wang, Jian-Zhi; Zhou, Xin-Wen

2012-12-01

The hyperphosphorylated tau is a major protein component of neurofibrillary tangle, which is one of hallmarks of Alzheimer's disease (AD). While the level of methylglyoxal (MG) is significantly increased in the AD brains, the role of MG in tau phosphorylation is still not reported. Here, we found that MG could induce tau hyperphosphorylation at multiple AD-related sites in neuroblastoma 2a cells under maintaining normal cell viability. MG treatment increased the level of advanced glycation end products (AGEs) and the receptor of AGEs (RAGE). Glycogen synthesis kinase-3β (GSK-3β) and p38 MAPK were activated, whereas the level and activity of JNK, Erk1/2, cdk5, and PP2A were not altered after MG treatment. Simultaneous inhibition of GSK-3β or p38 attenuated the MG-induced tau hyperphosphorylation. Aminoguanidine, a blocker of AGEs formation, could effectively reverse the MG-induced tau hyperphosphorylation. These data suggest that MG induces AD-like tau hyperphosphorylation through AGEs formation involving RAGE up-regulation and GSK-3β activation and p38 activation is also partially involved in MG-induced tau hyperphosphorylation. Thus, targeting MG may be a promising therapeutic strategy to prevent AD-like tau hyperphosphorylation.

Spironolactone differently influences remodeling of the left ventricle and aorta in L-NAME-induced hypertension.

PubMed

Simko, F; Matúsková, J; Lupták, I; Pincíková, T; Krajcírovicová, K; Stvrtina, S; Pomsár, J; Pelouch, V; Paulis, L; Pechánová, O

2007-01-01

Aldosterone receptor antagonist, spironolactone, has been shown to prevent remodeling of the heart in several models of left ventricular hypertrophy. The aim of the present study was to determine whether the treatment with spironolactone can prevent hypertension, reduction of tissue nitric oxide synthase activity and left ventricular (LV) and aortic remodeling in N(G)-nitro-L-arginine methyl ester (L-NAME)-induced hypertension. Four groups of rats were investigated: control, spironolactone (200 mg/kg), L-NAME (40 mg/kg) and L-NAME + spironolactone (in corresponding dosage). Animals were studied after 5 weeks of treatment. The decrease of NO-synthase activity in the LV and kidney was associated with the development of hypertension and LV hypertrophy, with increased DNA concentration in the LV, and remodeling of the aorta in the L-NAME group. Spironolactone prevented the inhibition of NO-synthase activity in the LV and kidney and partially attenuated hypertension and LVH development and the increase in DNA concentration. However, remodeling of the aorta was not prevented by spironolactone treatment. We conclude that the aldosterone receptor antagonist spironolactone improved nitric oxide production and partially prevented hypertension and LVH development without preventing hypertrophy of the aorta in NO-deficient hypertension. The reactive growth of the heart and aorta seems to be controlled by different mechanisms in L-NAME-induced hypertension.

Vascular ATP-sensitive potassium channels are over-expressed and partially regulated by nitric oxide in experimental septic shock.

PubMed

Collin, Solène; Sennoun, Nacira; Dron, Anne-Gaëlle; de la Bourdonnaye, Mathilde; Montemont, Chantal; Asfar, Pierre; Lacolley, Patrick; Meziani, Ferhat; Levy, Bruno

2011-05-01

To study the activation and expression of vascular (aorta and small mesenteric arteries) potassium channels during septic shock with or without modulation of the NO pathway. Septic shock was induced in rats by peritonitis. Selective inhibitors of vascular K(ATP) (PNU-37883A) or BK(Ca) [iberiotoxin (IbTX)] channels were used to demonstrate their involvement in vascular hyporeactivity. Vascular response to phenylephrine was measured on aorta and small mesenteric arteries mounted on a wire myograph. Vascular expression of potassium channels was studied by PCR and Western blot, in the presence or absence of 1400W, an inducible NO synthase (iNOS) inhibitor. Aortic activation of the transcriptional factor nuclear factor-kappaB (NF-κB) was assessed by electrophoretic mobility shift assay. Arterial pressure as well as in vivo and ex vivo vascular reactivity were reduced by sepsis and improved by PNU-37883A but not by IbTX. Sepsis was associated with an up-regulation of mRNA and protein expression of vascular K(ATP) channels, while expression of vascular BK(Ca) channels remained unchanged. Selective iNOS inhibition blunted the sepsis-induced increase in aortic NO, decreased NF-κB activation, and down-regulated vascular K(ATP) channel expression. Vascular K(ATP) but not BK(Ca) channels are activated, over-expressed, and partially regulated by NO via NF-κB activation during septic shock. Their selective inhibition restores arterial pressure and vascular reactivity and decreases lactate concentration. The present data suggest that selective vascular K(ATP) channel inhibitors offer potential therapeutic perspectives for septic shock.

Rapamycin reverses paraquat-induced acute lung injury in a rat model through inhibition of NFκB activation

PubMed Central

Chen, Da; Ma, Tao; Liu, Xiao-Wei; Yang, Chen; Liu, Zhi

2015-01-01

Objective: To evaluate the role of rapamycin (RAPA) in paraquat (PQ)-induced acute lung injury. Methods: Lung tissues were stained with HE and lung histology was observed. Mortality rate, and neutrophil and leukocyte count in blood and bronchoalveolar lavage fluid (BALF) were recorded. Protein content in BALF was determined by Coomassie blue staining. Malondialdehyde (MDA) content, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activity in blood were determined by thiobarbituric acid (TBA) assay, pyrogallol autoxidation method, and modified Haefman method, respectively. The NF-κB activity was measured by gel electrophoretic mobility shift assay (EMSA). Carbon dioxide partial pressure (PaCO2), partial pressure of oxygen (PaO2) and pH values were measured by automated blood gas analyzer. Results: HE staining results demonstrated RAPA alleviated pathological changes of acute alveolitis in SD rats. Trend of protein content in BALF was PQ group > RAPA treatment group > control group (P < 0.05). Neutrophil and leukocyte count in RAPA treatment group was significantly lower than PQ group at 3, 5, and 7 days after injection (P < 0.05). Trend of MDA content was RAPA treatment group > PQ group > control group (P < 0.05). Trend of GSH-Px and SOD activity was control group > RAPA treatment group > PQ group (P < 0.05). Compared with PQ group, PaO2 in RAPA treatment group was markedly higher and PaCO2 was lower (P < 0.05). Conclusion: PQ-induced acute lung injury was effectively reversed with RAPA, through inhibition of NF-κB activation. PMID:26191153

Phagolysosome acidification is required for silica and engineered nanoparticle-induced lysosome membrane permeabilization and resultant NLRP3 inflammasome activity

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

Jessop, Forrest; Hamilton, Raymond F.; Rhoderick,

NLRP3 inflammasome activation occurs in response to hazardous particle exposures and is critical for the development of particle-induced lung disease. Mechanisms of Lysosome Membrane Permeabilization (LMP), a central pathway for activation of the NLRP3 inflammasome by inhaled particles, are not fully understood. We demonstrate that the lysosomal vATPases inhibitor Bafilomycin A1 blocked LMP in vitro and ex vivo in primary murine macrophages following exposure to silica, multi-walled carbon nanotubes, and titanium nanobelts. Bafilomycin A1 treatment of particle-exposed macrophages also resulted in decreased active cathepsin L in the cytosol, a surrogate measure for leaked cathepsin B, which was associated with lessmore » NLRP3 inflammasome activity. Silica-induced LMP was partially dependent upon lysosomal cathepsins B and L, whereas nanoparticle-induced LMP occurred independent of cathepsin activity. Furthermore, inhibition of lysosomal cathepsin activity with CA-074-Me decreased the release of High Mobility Group Box 1. Together, these data support the notion that lysosome acidification is a prerequisite for particle-induced LMP, and the resultant leak of lysosome cathepsins is a primary regulator of ongoing NLRP3 inflammasome activity and release of HMGB1. - Highlights: • Silica and nanoparticles cause LMP in macrophages in vitro and in vivo. • Phagolysosome acidification is required for particle-induced LMP. • Cathepsin B and L are not required for nanoparticle-induced LMP. • Cathepsin B/L regulate the secretion of HMGB1 with particle exposure.« less

Nitric oxide is involved in hydrogen gas-induced cell cycle activation during adventitious root formation in cucumber.

PubMed

Zhu, Yongchao; Liao, Weibiao; Niu, Lijuan; Wang, Meng; Ma, Zhanjun

2016-06-28

Adventitious root development is a complex process regulated through a variety of signaling molecules. Hydrogen gas (H2) and nitric oxide (NO), two new signaling molecules are both involved in plant development and stress tolerance. To investigate the mechanism of adventitious root development induced by hydrogen-rich water (HRW), a combination of fluorescence microscopy and molecular approaches was used to study cell cycle activation and cell cycle-related gene expression in cucumber (Cucumis sativus 'Xinchun 4') explants. The results revealed that the effect of HRW on adventitious root development was dose-dependent, with maximal biological responses at 50 % HRW. HRW treatment increased NO content in a time-dependent fashion. The results also indicated that HRW and NO promoted the G1-to-S transition and up-regulated cell cycle-related genes: CycA (A-type cyclin), CycB (B-type cyclin), CDKA (cyclin-dependent kinase A) and CDKB (cyclin-dependent kinase B) expression. Additionally, target genes related to adventitious rooting were up-regulated by HRW and NO in cucumber explants. While, the responses of HRW-induced adventitious root development and increase of NO content were partially blocked by a specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt, NO synthase (NOS)-like enzyme inhibitor N(G) -nitro-L-arginine methylester hydrochloride, or nitrate reductase inhibitors tungstate and NaN3. These chemicals also partially reversed the effect of HRW on cell cycle activation and the transcripts of cell cycle regulatory genes and target genes related adventitious root formation. Together, NO may emerge as a downstream signaling molecule in H2-induced adventitious root organogenesis. Additionally, H2 mediated cell cycle activation via NO pathway during adventitious root formation.

Mitochondrial control of cell death induced by hyperosmotic stress.

PubMed

Criollo, Alfredo; Galluzzi, Lorenzo; Maiuri, M Chiara; Tasdemir, Ezgi; Lavandero, Sergio; Kroemer, Guido

2007-01-01

HeLa and HCT116 cells respond differentially to sorbitol, an osmolyte able to induce hypertonic stress. In these models, sorbitol promoted the phenotypic manifestations of early apoptosis followed by complete loss of viability in a time-, dose-, and cell type-specific fashion, by eliciting distinct yet partially overlapping molecular pathways. In HCT116 but not in HeLa cells, sorbitol caused the mitochondrial release of the caspase-independent death effector AIF, whereas in both cell lines cytochrome c was retained in mitochondria. Despite cytochrome c retention, HeLa cells exhibited the progressive activation of caspase-3, presumably due to the prior activation of caspase-8. Accordingly, caspase inhibition prevented sorbitol-induced killing in HeLa, but only partially in HCT116 cells. Both the knock-out of Bax in HCT116 cells and the knock-down of Bax in A549 cells by RNA interference reduced the AIF release and/or the mitochondrial alterations. While the knock-down of Bcl-2/Bcl-X(L) sensitized to sorbitol-induced killing, overexpression of a Bcl-2 variant that specifically localizes to mitochondria (but not of the wild-type nor of a endoplasmic reticulum-targeted form) strongly inhibited sorbitol effects. Thus, hyperosmotic stress kills cells by triggering different molecular pathways, which converge at mitochondria where pro- and anti-apoptotic members of the Bcl-2 family exert their control.

Differential effects of the new glucocorticoid receptor antagonist ORG 34517 and RU486 (mifepristone) on glucocorticoid receptor nuclear translocation in the AtT20 cell line.

PubMed

Peeters, B W M M; Ruigt, G S F; Craighead, M; Kitchener, P

2008-12-01

Glucocorticoid agonists bind to cytoplasmic glucocorticoid receptors (GRs) and subsequently translocate as an agonist-GR complex into the nucleus. In the nucleus the complex regulates the transcription of target genes. A number of GR antagonists (RU486, progesterone, RU40555) have also been shown to induce receptor translocation. These compounds should be regarded as partial agonists. For the nonselective progesterone receptor antagonists, RTI3021-012 and RTI3021-022, it was shown that GR antagonism is possible without the induction of GR translocation. In the present studies, the new GR antagonist, ORG 34517, was investigated for its potential to induce GR translocation and to antagonize corticosterone-induced GR translocation in the AtT20 (mouse pituitary) cell line. ORG 34517 was compared to RU486. In contrast to RU486, ORG 34517 (at doses up to 3 x 10(-7) M) did not induce GR translocation, but was able to block corticosterone (3 x 10(-8) M) induced GR translocation. ORG 34517 can be regarded as a true competitive GR antagonist without partial agonistic activities.

Toll-like receptor 4 mediates lipopolysaccharide-induced muscle catabolism via coordinate activation of ubiquitin-proteasome and autophagy-lysosome pathways

PubMed Central

Doyle, Alexander; Zhang, Guohua; Abdel Fattah, Elmoataz A.; Eissa, N. Tony; Li, Yi-Ping

2011-01-01

Cachectic muscle wasting is a frequent complication of many inflammatory conditions, due primarily to excessive muscle catabolism. However, the pathogenesis and intervention strategies against it remain to be established. Here, we tested the hypothesis that Toll-like receptor 4 (TLR4) is a master regulator of inflammatory muscle catabolism. We demonstrate that TLR4 activation by lipopolysaccharide (LPS) induces C2C12 myotube atrophy via up-regulating autophagosome formation and the expression of ubiquitin ligase atrogin-1/MAFbx and MuRF1. TLR4-mediated activation of p38 MAPK is necessary and sufficient for the up-regulation of atrogin1/MAFbx and autophagosomes, resulting in myotube atrophy. Similarly, LPS up-regulates muscle autophagosome formation and ubiquitin ligase expression in mice. Importantly, autophagy inhibitor 3-methyladenine completely abolishes LPS-induced muscle proteolysis, while proteasome inhibitor lactacystin partially blocks it. Furthermore, TLR4 knockout or p38 MAPK inhibition abolishes LPS-induced muscle proteolysis. Thus, TLR4 mediates LPS-induced muscle catabolism via coordinate activation of the ubiquitin-proteasome and the autophagy-lysosomal pathways.—Doyle, A., Zhang, G., Abdel Fattah, E. A., Eissa, N. T., Li, Y.-P. Toll-like receptor 4 mediates lipopolysaccharide-induced muscle catabolism via coordinate activation of ubiquitin-proteasome and autophagy-lysosome pathways. PMID:20826541

Chemokine CXCL13 mediates orofacial neuropathic pain via CXCR5/ERK pathway in the trigeminal ganglion of mice.

PubMed

Zhang, Qian; Cao, De-Li; Zhang, Zhi-Jun; Jiang, Bao-Chun; Gao, Yong-Jing

2016-07-11

Trigeminal nerve damage-induced neuropathic pain is a severely debilitating chronic orofacial pain syndrome. Spinal chemokine CXCL13 and its receptor CXCR5 were recently demonstrated to play a pivotal role in the pathogenesis of spinal nerve ligation-induced neuropathic pain. Whether and how CXCL13/CXCR5 in the trigeminal ganglion (TG) mediates orofacial pain are unknown. The partial infraorbital nerve ligation (pIONL) was used to induce trigeminal neuropathic pain in mice. The expression of ATF3, CXCL13, CXCR5, and phosphorylated extracellular signal-regulated kinase (pERK) in the TG was detected by immunofluorescence staining and western blot. The effect of shRNA targeting on CXCL13 or CXCR5 on pain hypersensitivity was checked by behavioral testing. pIONL induced persistent mechanical allodynia and increased the expression of ATF3, CXCL13, and CXCR5 in the TG. Inhibition of CXCL13 or CXCR5 by shRNA lentivirus attenuated pIONL-induced mechanical allodynia. Additionally, pIONL-induced neuropathic pain and the activation of ERK in the TG were reduced in Cxcr5 (-/-) mice. Furthermore, MEK inhibitor (PD98059) attenuated mechanical allodynia and reduced TNF-α and IL-1β upregulation induced by pIONL. TNF-α inhibitor (Etanercept) and IL-1β inhibitor (Diacerein) attenuated pIONL-induced orofacial pain. Finally, intra-TG injection of CXCL13 induced mechanical allodynia, increased the activation of ERK and the production of TNF-α and IL-1β in the TG of WT mice, but not in Cxcr5 (-/-) mice. Pretreatment with PD98059, Etanercept, or Diacerein partially blocked CXCL13-induced mechanical allodynia, and PD98059 also reduced CXCL13-induced TNF-α and IL-1β upregulation. CXCL13 and CXCR5 contribute to orofacial pain via ERK-mediated proinflammatory cytokines production. Targeting CXCL13/CXCR5/ERK/TNF-α and IL-1β pathway in the trigeminal ganglion may offer effective treatment for orofacial neuropathic pain.

Involvement of peripheral mechanism in the verapamil-induced potentiation of morphine analgesia in mice.

PubMed

Shimizu, Norifumi; Kishioka, Shiroh; Maeda, Takehiko; Fukazawa, Yohji; Dake, Yoshihiro; Yamamoto, Chizuko; Ozaki, Masanobu; Yamamoto, Hiroyuki

2004-08-01

Morphine's analgesic actions are thought to be mediated through both the central and peripheral nervous systems. L-type calcium channel blockers have been reported to potentiate the analgesic effects of morphine, but the locus of this interaction is not known. In this experiment, we examined the site of verapamil-induced potentiation of morphine analgesia in mice using the quaternary opioid receptor antagonist naloxone-methiodide (NLX-M). Subcutaneous injections of morphine increased locomotor activity and serum corticosterone level, which are mediated by the central nervous system. These central effects were not antagonized by 0.1 mg/kg of NLX-M, whereas this dose of NLX-M partially antagonized the analgesic effect of morphine. Treatment with verapamil potentiated morphine analgesia in a dose-dependent manner. The verapamil-induced potentiation of morphine analgesia was abolished by pretreatment with NLX-M (0.1 and 1 mg/kg). These findings suggest that peripheral mechanisms partially contribute to morphine analgesia and mediate the potentiation of morphine analgesia by verapamil.

Hepatic injury induces contrasting response in liver and kidney to chemicals that are metabolically activated: Role of male sex hormone

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

Kim, Young C.; Yim, Hye K.; Jung, Young S.

2007-08-15

Injury to liver, resulting in loss of its normal physiological/biochemical functions, may adversely affect a secondary organ. We examined the response of the liver and kidney to chemical substances that require metabolic activation for their toxicities in mice with a preceding liver injury. Carbon tetrachloride treatment 24 h prior to a challenging dose of carbon tetrachloride or acetaminophen decreased the resulting hepatotoxicity both in male and female mice as determined by histopathological examination and increases in serum enzyme activities. In contrast, the renal toxicity of the challenging toxicants was elevated markedly in male, but not in female mice. Partial hepatectomymore » also induced similar changes in the hepatotoxicity and nephrotoxicity of a challenging toxicant, suggesting that the contrasting response of male liver and kidney was associated with the reduction of the hepatic metabolizing capacity. Carbon tetrachloride pretreatment or partial hepatectomy decreased the hepatic xenobiotic-metabolizing enzyme activities in both sexes but elevated the renal p-nitrophenol hydroxylase, p-nitroanisole O-demethylase and aminopyrine N-demethylase activities significantly only in male mice. Increases in Cyp2e1 and Cyp2b expression were also evident in male kidney. Castration of males or testosterone administration to females diminished the sex-related differences in the renal response to an acute liver injury. The results indicate that reduction of the hepatic metabolizing capacity induced by liver injury may render secondary target organs susceptible to chemical substances activated in these organs. This effect may be sex-specific. It is also suggested that an integrated approach should be taken for proper assessment of chemical hazards.« less

H{sub 2}S induces vasoconstriction of rat cerebral arteries via cAMP/adenylyl cyclase pathway

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

Li, Sen; Ping, Na-na; Cao, Lei, E-mail: leicao@mail.xjtu.edu.cn

2015-12-15

Hydrogen sulfide (H{sub 2}S), traditionally known for its toxic effects, is now involved in regulating vascular tone. Here we investigated the vasoconstrictive effect of H{sub 2}S on cerebral artery and the underlying mechanism. Sodium hydrosulfide (NaHS), a donor of H{sub 2}S, concentration-dependently induced vasoconstriction on basilar artery, which was enhanced in the presence of isoprenaline, a β-adrenoceptor agonist or forskolin, an adenylyl cyclase activator. Administration of NaHS attenuated the vasorelaxant effects of isoprenaline or forskolin. Meanwhile, the NaHS-induced vasoconstriction was diminished in the presence of 8B-cAMP, an analog of cAMP, but was not affected by Bay K-8644, a selective L-typemore » Ca{sup 2+} channel agonist. These results could be explained by the revised effects of NaHS on isoprenaline-induced cAMP elevation and forskolin-stimulated adenylyl cyclase activity. Additionally, NaHS-induced vasoconstriction was enhanced by removing the endothelium or in the presence of L-NAME, an inhibitor of nitric oxide synthase. L-NAME only partially attenuated the effect of NaHS which was given together with forskolin on the pre-contracted artery. In conclusion, H{sub 2}S induces vasoconstriction of cerebral artery via, at least in part, cAMP/adenylyl cyclase pathway. - Highlights: • The vasoactivity effect of NaHS, a donor of H{sub 2}S, was studied on rat cerebral arteries. • H{sub 2}S induces a constriction, not a relaxant effect on basilar arteries. • The vasoconstrictive effect is invovled in inhibiting adenylyl cyclase to reduce cAMP levels. • The vasoconstriction is partially antagonized by NO, and does not necessarily act via NO pathway.« less

Effects of protein kinase C activators on phorbol ester-sensitive and -resistant EL4 thymoma cells.

PubMed

Sansbury, H M; Wisehart-Johnson, A E; Qi, C; Fulwood, S; Meier, K E

1997-09-01

Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12-myristate 13-acetate with activation of ERK mitogen-activated protein kinases, synthesis of interleukin-2, and death, whereas phorbol ester-resistant variants of this cell line do not exhibit these responses. Additional aspects of the resistant phenotype were examined, using a newly-established resistant cell line. Phorbol ester induced morphological changes, ERK activation, calcium-dependent activation of the c-Jun N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in sensitive but not resistant cells. A series of protein kinase C activators caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and theta in both cell lines. While PKC eta was expressed at higher levels in sensitive than in resistant cells, overexpression of PKC eta did not restore phorbol ester-induced ERK activation to resistant cells. In sensitive cells, PKC activators had similar effects on cell viability and ERK activation, but differed in their abilities to induce JNK activation and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK activation and completely blocked phorbol ester-induced cell death in sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or interleukin-2 synthesis, appears to be required for phorbol ester-induced toxicity. Alterations in phorbol ester response pathways, rather than altered expression of PKC isoforms, appear to confer phorbol ester resistance to EL4 cells.

Partial Genetic Deletion of Neuregulin 1 Modulates the Effects of Stress on Sensorimotor Gating, Dendritic Morphology, and HPA Axis Activity in Adolescent Mice

PubMed Central

Chohan, Tariq W.; Boucher, Aurelie A.; Spencer, Jarrah R.; Kassem, Mustafa S.; Hamdi, Areeg A.; Karl, Tim; Fok, Sandra Y.; Bennett, Maxwell R.; Arnold, Jonathon C.

2014-01-01

Stress has been linked to the pathogenesis of schizophrenia. Genetic variation in neuregulin 1 (NRG1) increases the risk of developing schizophrenia and may help predict which high-risk individuals will transition to psychosis. NRG1 also modulates sensorimotor gating, a schizophrenia endophenotype. We used an animal model to demonstrate that partial genetic deletion of Nrg1 interacts with stress to promote neurobehavioral deficits of relevance to schizophrenia. Nrg1 heterozygous (HET) mice displayed greater acute stress-induced anxiety-related behavior than wild-type (WT) mice. Repeated stress in adolescence disrupted the normal development of higher prepulse inhibition of startle selectively in Nrg1 HET mice but not in WT mice. Further, repeated stress increased dendritic spine density in pyramidal neurons of the medial prefrontal cortex (mPFC) selectively in Nrg1 HET mice. Partial genetic deletion of Nrg1 also modulated the adaptive response of the hypothalamic-pituitary-adrenal axis to repeated stress, with Nrg1 HET displaying a reduced repeated stress-induced level of plasma corticosterone than WT mice. Our results demonstrate that Nrg1 confers vulnerability to repeated stress-induced sensorimotor gating deficits, dendritic spine growth in the mPFC, and an abberant endocrine response in adolescence. PMID:24442851

Fermented guava leaf extract inhibits LPS-induced COX-2 and iNOS expression in Mouse macrophage cells by inhibition of transcription factor NF-kappaB.

PubMed

Choi, Soo-Youn; Hwang, Joon-Ho; Park, Soo-Young; Jin, Yeong-Jun; Ko, Hee-Chul; Moon, Sang-Wook; Kim, Se-Jae

2008-08-01

The goal of this study was to elucidate the antiinflammatory activities of Psidium guajava L. (guava) leaf. To improve the functionality of guava leaf, it was fermented with Phellinus linteus mycelia, Lactobacillus plantarum and Saccharomyces cerevisiae. The ethanol extract from fermented guava leaf inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production. Western blot analysis showed that fermented guava leaf extract decreased LPS-induced inducible nitric oxide synthase (iNOS) and the cyclooxygenase-2 (COX-2) protein level in RAW 264.7 cells. To investigate the mechanism involved, the study examined the effect of fermented guava leaf extract on LPS-induced nuclear factor-kappaB (NF-kappaB) activation. Fermented guava leaf extract significantly inhibited LPS-induced NF-kappaB transcriptional activity. Immunochemical analysis revealed that fermented guava leaf extract suppressed LPS-induced degradation of I-kappaBalpha. Taken together, the data indicate that fermented guava leaf extract is involved in the inhibition of iNOS and COX-2 via the down-regulation of NF-kappaB pathway, revealing a partial molecular basis for the antiinflammatory properties of fermented guava leaf extract.

[DNA-dependent DNA polymerase induced by herpes virus papio (HVP) in producing cells].

PubMed

D'iachenko, A G; Beriia, L Ia; Matsenko, L D; Kakubava, V V; Kokosh, L V

1980-11-01

A new DNA polymerase was found in the cells of suspension lymphoblastoid cultures, which produce lymphotropic baboon herpes virus (HVP). The enzyme was isolated in a partially purified form. In some properties the enzyme differs from other cellular DNA polymerases. The HVP-induced DNA polymerase has the molecular weight of 1,6 x 10(5) and sedimentation coefficient of about 8S. The enzyme is resistant to high salt concentrations and N-ethylmaleimide, but shows a pronounced sensitivity to phosphonoacetate. The enzyme effectively copies "activated" DNA and synthetic deoxyribohomopolymers. The attempts to detect the DNA polymerase activity in HVP virions were unsuccessful.

DNA-polymerase induced by Herpesvirus papio (HVP) in cells of lymphoblastoid cultures derived from lymphomatous baboons. Report V.

PubMed

Djachenko, A G; Lapin, B A

1981-01-01

A new DNA-polymerase was found in the cells of suspension lymphoblastoid cultures which produce lymphotropic baboon herpesvirus (HVP). This enzyme was isolated in a partially purified form. Some of its properties vary from those of other cellular DNA-polymerases. HVP-induced DNA-polymerase has a molecule weight of 160,000 and sedimentation coefficient of about 8 S. The enzyme is resistant to high salt concentration and N-ethylmaleimide, but it is very sensitive to phosphonoacetate. It effectively copies "activated" DNA and synthetic deoxyribohomopolymers. Attempts to reveal the DNA-polymerase activity in HVP virions were unsuccessful.

Shoot inversion inhibition of stem elongation in Pharbitis nil: a possible role for ethylene-induced glycoprotein and lignin

NASA Technical Reports Server (NTRS)

Prasad, T. K.; Cline, M. G.

1987-01-01

Inversion of the upper shoot of Pharbitis nil results in the inhibition of elongation in the inverted stem. The objective of the present study was to determine how shoot inversion-induced gravity stress inhibited elongation and to elucidate the possible role of ethylene-induced glycoprotein and lignin in this process. Determinations of hydroxyproline, peroxidase, phenylalanine ammonia-lyase (PAL), phenol, and lignin content/activity were carried out by appropriate spectrophotometric methods. It was found that inversion and Ethrel treatments of upright shoots caused significant increases in hydroxyproline content, peroxidase, and PAL activity in 12 hours and in phenol and lignin contents in 24 hours. All of these increases except for that of cytoplasmic peroxidase activity were partially reversed by AgNO3, the ethylene action inhibitor. It is concluded that possible cross-linking associated with the accumulation of the ethylene-induced hydroxyproline-rich glycoprotein and lignin may be responsible for the later stages of cessation of elongation in the inverted Pharbitis shoot.

Activation of acetyl-coenzyme A carboxylase is involved in Taxol-induced ovarian cancer cell death

PubMed Central

WU, JIANG; JI, FANG; DI, WEN; CHEN, HONGDUO; WAN, YINSHENG

2011-01-01

Acetyl-coenzyme A carboxylase (ACC) is an attractive target for research into the treatment of a variety of human diseases, including diabetes, obesity and cancer. Mounting evidence suggests that the inhibition of ACC induced of cancer cell apoptosis. However, whether the inhibition of ACC regulates apoptosis in CaOV3 cancer cells has yet to be addressed. This study investigated the cytotoxic mechanism of action of ACC inhibition. Results showed that 5-(tetradecyloxy)-2-furoic acid (TOFA), an ACC inhibitor, enhanced Taxol-induced CaOV3 human ovarian cancer cell apoptosis. Notably, when TOFA was administered as a monotherapy, it induced CaOV3 cell apoptosis. Pre-treatment with the EGFR inhibitor PD153035 was found to markedly enhance ACC phosphorylation, whereas AMP-activated protein kinase (AMPK) activator AICAR was found to marginally enhance ACC phosphorylation. Taken together, the data showed ACC is a potential novel molecular target of Taxol. Additionally, ACC inhibition partially contributed to the cytotoxic effect of Taxol in ovarian cancer cells. PMID:22866118

Activation of acetyl-coenzyme A carboxylase is involved in Taxol-induced ovarian cancer cell death.

PubMed

Wu, Jiang; Ji, Fang; DI, Wen; Chen, Hongduo; Wan, Yinsheng

2011-05-01

Acetyl-coenzyme A carboxylase (ACC) is an attractive target for research into the treatment of a variety of human diseases, including diabetes, obesity and cancer. Mounting evidence suggests that the inhibition of ACC induced of cancer cell apoptosis. However, whether the inhibition of ACC regulates apoptosis in CaOV3 cancer cells has yet to be addressed. This study investigated the cytotoxic mechanism of action of ACC inhibition. Results showed that 5-(tetradecyloxy)-2-furoic acid (TOFA), an ACC inhibitor, enhanced Taxol-induced CaOV3 human ovarian cancer cell apoptosis. Notably, when TOFA was administered as a monotherapy, it induced CaOV3 cell apoptosis. Pre-treatment with the EGFR inhibitor PD153035 was found to markedly enhance ACC phosphorylation, whereas AMP-activated protein kinase (AMPK) activator AICAR was found to marginally enhance ACC phosphorylation. Taken together, the data showed ACC is a potential novel molecular target of Taxol. Additionally, ACC inhibition partially contributed to the cytotoxic effect of Taxol in ovarian cancer cells.

Lack of induction of tissue transglutaminase but activation of the preexisting enzyme in c-Myc-induced apoptosis of CHO cells.

PubMed

Balajthy, Z; Kedei, N; Nagy, L; Davies, P J; Fésüs, L

1997-07-18

The intracellular activity and expression of tissue transglutaminase, which crosslinks proteins through epsilon(gamma-glutamyl)lysine isodipeptide bond, was investigated in CHO cells and those stably transfected with either inducible c-Myc (which leads to apoptosis) or with c-myc and the apoptosis inhibitor Bcl-2. Protein-bound cross-link content was significantly higher when apoptosis was induced by c-Myc while the concomitant presence of Bcl-2 markedly reduced both apoptosis and enzymatic protein cross-linking. The expression of tissue transglutaminase did not change following the initiation of apoptosis by c-Myc or when it was blocked by Bcl-2. Studying transiently co-transfected elements of the mouse tissue transglutaminase promoter linked to a reporter enzyme revealed their overall repression in cells expressing c-Myc. This repression was partially suspended in cells also carrying Bcl-2. Our data suggest that tissue transglutaminase is not induced when c-Myc initiates apoptosis but the pre-existing endogenous enzyme is activated.

Huntingtin-interacting protein 1-mediated neuronal cell death occurs through intrinsic apoptotic pathways and mitochondrial alterations.

PubMed

Choi, Shin Ae; Kim, Steven J; Chung, Kwang Chul

2006-10-02

Huntingtin interacting protein-1 (Hip1) is known to be associated with the N-terminal domain of huntingtin. Although Hip1 can induce apoptosis, the exact upstream signal transduction pathways have not been clarified yet. In the present study, we examined whether activation of intrinsic and/or extrinsic apoptotic pathways occurs during Hip1-mediated neuronal cell death. Overexpression of Hip1 induced cell death through caspase-3 activation in immortalized hippocampal neuroprogenitor cells. Interestingly, proteolytic processing of Hip1 into partial fragments was observed in response to Hip1 transfection and apoptosis-inducing drugs. Moreover, Hip1 was found to directly bind to and activate caspase-9. This promoted cytosolic release of cytochrome c and apoptosis-inducing factor via mitochondrial membrane perturbation. Furthermore, Hip1 could directly bind to Apaf-1, suggesting that the neurotoxic signals of Hip1 transmit through the intrinsic mitochondrial apoptotic pathways and the formation of apoptosome complex.

HDAC2 Suppresses IL17A-Mediated Airway Remodeling in Human and Experimental Modeling of COPD.

PubMed

Lai, Tianwen; Tian, Baoping; Cao, Chao; Hu, Yue; Zhou, Jiesen; Wang, Yong; Wu, Yanping; Li, Zhouyang; Xu, Xuchen; Zhang, Min; Xu, Feng; Cao, Yuan; Chen, Min; Wu, Dong; Wu, Bin; Dong, Chen; Li, Wen; Ying, Songmin; Chen, Zhihua; Shen, Huahao

2018-04-01

Although airway remodeling is a central feature of COPD, the mechanisms underlying its development have not been fully elucidated. The goal of this study was to determine whether histone deacetylase (HDAC) 2 protects against cigarette smoke (CS)-induced airway remodeling through IL-17A-dependent mechanisms. Sputum samples and lung tissue specimens were obtained from control subjects and patients with COPD. The relationships between HDAC2, IL-17A, and airway remodeling were investigated. The effect of HDAC2 on IL-17A-mediated airway remodeling was assessed by using in vivo models of COPD induced by CS and in vitro culture of human bronchial epithelial cells and primary human fibroblasts exposed to CS extract, IL-17A, or both. HDAC2 and IL-17A expression in the sputum cells and lung tissue samples of patients with COPD were associated with bronchial wall thickening and collagen deposition. Il-17a deficiency (Il-17a -/- ) resulted in attenuation of, whereas Hdac2 deficiency (Hdac2 +/- ) exacerbated, CS-induced airway remodeling in mice. IL-17A deletion also attenuated airway remodeling in CS-exposed Hdac2 +/- mice. HDAC2 regulated IL-17A production partially through modulation of CD4 + T cells during T helper 17 cell differentiation and retinoid-related orphan nuclear receptor γt in airway epithelial cells. In vitro, IL-17A deficiency attenuated CS-induced mouse fibroblast activation from Hdac2 +/- mice. IL-17A-induced primary human fibroblast activation was at least partially mediated by autocrine production of transforming growth factor beta 1. These findings suggest that activation of HDAC2 and/or inhibition of IL-17A production could prevent the development of airway remodeling by suppressing airway inflammation and modulating fibroblast activation in COPD. Copyright © 2017. Published by Elsevier Inc.

Prophylactic Oral Administration of Magnesium Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice through a Decrease of Colonic Accumulation of P2X7 Receptor-Expressing Mast Cells.

PubMed

Ohbori, Kenshi; Fujiwara, Makiko; Ohishi, Akihiro; Nishida, Kentaro; Uozumi, Yoshinobu; Nagasawa, Kazuki

2017-01-01

The number of patients with colitis has been increasing year by year. Recently, intestinal inflammation, as one of the factors for its onset, has been demonstrated to be induced by P2X7 receptor-mediated activation of colonic immune cells such as mast cells. Activation of P2X7 receptor (P2X7R) is known to be inhibited by divalent metal cations such as magnesium, but whether or not magnesium administration prevents/relieves colitis is unknown so far. Here, we report that oral (per os (p.o.)) administration of MgCl 2 and ingestion of commercially available magnesium-rich mineral hard water relieves dextran sulfate sodium (DSS)-induced colitis in mice. Colitis was induced through ingestion of a 3% (w/v) DSS solution ad libitum for 10 d. Brilliant blue G (BBG, a P2X7R antagonist), MgCl 2 or magnesium-rich mineral hard water was administered p.o. to mice via gastric intubation once a day or ad libitum from a day before DSS administration for 11 times or 11 d, respectively. DSS-treated mice exhibited a low disease activity index, a short colon and a high histological score compared to in control mice. As BBG (250 mg/kg, p.o.), administration of a MgCl 2 solution (100 or 500 mg/kg, p.o.) and ad libitum ingestion of the magnesium-rich mineral hard water (212 ppm as magnesium) partially, but significantly, attenuated the severity of colitis by decreasing the accumulation of P2X7R-immunopositive mast cells in the colon. Therefore, prophylactic p.o. administration/ingestion of magnesium is considered to be partially effective to protect mice against DSS-induced colitis by inhibiting P2X7R-mediated activation/accumulation of colonic mast cells.

Partial reinforcement, extinction, and placebo analgesia

PubMed Central

Yeung, Siu Tsin Au; Colagiuri, Ben; Lovibond, Peter F.; Colloca, Luana

2014-01-01

Numerous studies indicate that placebo analgesia can be established via conditioning procedures. However, these studies have exclusively involved conditioning under continuous reinforcement. Thus, it is currently unknown whether placebo analgesia can be established under partial reinforcement and how durable any such effect would be. We tested this possibility using electro-cutaneous pain in healthy volunteers. Sixty undergraduates received placebo treatment (activation of a sham electrode) under the guise of an analgesic trial. The participants were randomly allocated to different conditioning schedules, namely continuous reinforcement (CRF), partial reinforcement (PRF), or control (no conditioning). Conditioning was achieved by surreptitiously reducing pain intensity during training when the placebo was activated compared with when it was inactive. For the CRF group, the placebo was always followed by a surreptitious reduction in pain during training. For the PRF group, the placebo was followed by a reduction in pain stimulation on 62.5% of trials only. In the test phase, pain stimulation was equivalent across placebo and no placebo trials. Both continuous and partial reinforcement produced placebo analgesia, with the magnitude of initial analgesia being larger following continuous reinforcement. However, while the placebo analgesia established under continuous reinforcement extinguished during test phase, the placebo analgesia established under partial reinforcement did not. These findings indicate that partial reinforcement can induce placebo analgesia and that these effects are more resistant to extinction than those established via continuous reinforcement. Partial reinforcement may, therefore, reflect a novel way of enhancing clinical outcomes via the placebo effect. PMID:24602997

Coincidence in Time of the Imbrium Basin Impact and Apollo 15 KREEP Volcanic Flows: The Case for Impact-Induced Melting

NASA Technical Reports Server (NTRS)

Ryder, Graham

1994-01-01

On the Earth there is no firm evidence that impacts can induce volcanic activity. However, the Moon does provide a very likely example of volcanism induced by an immense impact: the Imbrium basin-forming event was immediately succeeded by a crustal partial melting event that released basalt flows characterized by K, rare-earth elements (REE), P, and other trace elements (KREEP) over a wide area creating the Apennine Bench Formation. Impact total melting is inconsistent with the chemistry and petrography of these Apollo 15 KREEP basalts, which are quite unlike the impact melts recognized at Taurus-Littrow as the products of the Serenitatis impact. The Imbrium impact and the KREEP volcanic events are indistinguishable in radiometric age, and thus the volcanism occurred less than about 20 Ma later than the impact (less than about 0.5% of lunar history). The sample record indicates that such KREEP volcanism had not occurred in the region prior to that time, and demonstrates that it never occurred again. Such coincidence in time implies a genetic relationship between the two events, and impact-induced partial melting or release appears to be the only feasible process. Nonetheless, the characteristics of the Apollo 15 KREEP basalts suggest large-degree crustal melting that is not easy to reconcile with the inability of lunar pressure release alone to induce partial melting unless the source was already almost at its melting point. The earliest history of the surface of the Earth, at a time of greater internal heat production and basin-forming impacts, could have been greatly influenced by impact-induced melting.

DOR activation inhibits anoxic/ischemic Na+ influx through Na+ channels via PKC mechanisms in the cortex.

PubMed

Chao, Dongman; He, Xiaozhou; Yang, Yilin; Bazzy-Asaad, Alia; Lazarus, Lawrence H; Balboni, Gianfranco; Kim, Dong H; Xia, Ying

2012-08-01

Activation of delta-opioid receptors (DOR) is neuroprotective against hypoxic/ischemic injury in the cortex, which is at least partially related to its action against hypoxic/ischemic disruption of ionic homeostasis that triggers neuronal injury. Na(+) influx through TTX-sensitive voltage-gated Na(+) channels may be a main mechanism for hypoxia-induced disruption of K(+) homeostasis, with DOR activation attenuating the disruption of ionic homeostasis by targeting voltage-gated Na(+) channels. In the present study we examined the role of DOR in the regulation of Na(+) influx in anoxia and simulated ischemia (oxygen-glucose deprivation) as well as the effect of DOR activation on the Na(+) influx induced by a Na(+) channel opener without anoxic/ischemic stress and explored a potential PKC mechanism underlying the DOR action. We directly measured extracellular Na(+) activity in mouse cortical slices with Na(+) selective electrodes and found that (1) anoxia-induced Na(+) influx occurred mainly through TTX-sensitive Na(+) channels; (2) DOR activation inhibited the anoxia/ischemia-induced Na(+) influx; (3) veratridine, a Na(+) channel opener, enhanced the anoxia-induced Na(+) influx; this could be attenuated by DOR activation; (4) DOR activation did not reduce the anoxia-induced Na(+) influx in the presence of chelerythrine, a broad-spectrum PKC blocker; and (5) DOR effects were blocked by PKCβII peptide inhibitor, and PKCθ pseudosubstrate inhibitor, respectively. We conclude that DOR activation inhibits anoxia-induced Na(+) influx through Na(+) channels via PKC (especially PKCβII and PKCθ isoforms) dependent mechanisms in the cortex. Copyright © 2012 Elsevier Inc. All rights reserved.

Constitutive activation of NF-kappa B and secretion of interleukin-8 induced by the G protein-coupled receptor of Kaposi's sarcoma-associated herpesvirus involve G alpha(13) and RhoA.

PubMed

Shepard, L W; Yang, M; Xie, P; Browning, D D; Voyno-Yasenetskaya, T; Kozasa, T; Ye, R D

2001-12-07

The Kaposi's sarcoma herpesvirus (KSHV) open reading frame 74 encodes a G protein-coupled receptor (GPCR) for chemokines. Exogenous expression of this constitutively active GPCR leads to cell transformation and vascular overgrowth characteristic of Kaposi's sarcoma. We show here that expression of KSHV-GPCR in transfected cells results in constitutive transactivation of nuclear factor kappa B (NF-kappa B) and secretion of interleukin-8, and this response involves activation of G alpha(13) and RhoA. The induced expression of a NF-kappa B luciferase reporter was partially reduced by pertussis toxin and the G beta gamma scavenger transducin, and enhanced by co-expression of G alpha(13) and to a lesser extent, G alpha(q). These results indicate coupling of KSHV-GPCR to multiple G proteins for NF-kappa B activation. Expression of KSHV-GPCR led to stress fiber formation in NIH 3T3 cells. To examine the involvement of the G alpha(13)-RhoA pathway in KSHV-GPCR-mediated NF-kappa B activation, HeLa cells were transfected with KSHV-GPCR alone and in combination with the regulator of G protein signaling (RGS) from p115RhoGEF or a dominant negative RhoA(T19N). Both constructs, as well as the C3 exoenzyme from Clostritium botulinum, partially reduced NF-kappa B activation by KSHV-GPCR, and by a constitutively active G alpha(13)(Q226L). KSHV-GPCR-induced NF-kappa B activation is accompanied by increased secretion of IL-8, a function mimicked by the activated G alpha(13) but not by an activated G alpha(q)(Q209L). These results suggest coupling of KSHV-GPCR to the G alpha(13)-RhoA pathway in addition to other G proteins.

Endoplasmic Reticulum Stress Mediates Methamphetamine-Induced Blood–Brain Barrier Damage

PubMed Central

Qie, Xiaojuan; Wen, Di; Guo, Hongyan; Xu, Guanjie; Liu, Shuai; Shen, Qianchao; Liu, Yi; Zhang, Wenfang; Cong, Bin; Ma, Chunling

2017-01-01

Methamphetamine (METH) abuse causes serious health problems worldwide, and long-term use of METH disrupts the blood–brain barrier (BBB). Herein, we explored the potential mechanism of endoplasmic reticulum (ER) stress in METH-induced BBB endothelial cell damage in vitro and the therapeutic potential of endoplasmic reticulum stress inhibitors for METH-induced BBB disruption in C57BL/6J mice. Exposure of immortalized BMVEC (bEnd.3) cells to METH significantly decreased cell viability, induced apoptosis, and diminished the tightness of cell monolayers. METH activated ER stress sensor proteins, including PERK, ATF6, and IRE1, and upregulated the pro-apoptotic protein CHOP. The ER stress inhibitors significantly blocked the upregulation of CHOP. Knockdown of CHOP protected bEnd.3 cells from METH-induced cytotoxicity. Furthermore, METH elevated the production of reactive oxygen species (ROS) and induced the dysfunction of mitochondrial characterized by a Bcl2/Bax ratio decrease, mitochondrial membrane potential collapse, and cytochrome c. ER stress release was partially reversed by ROS inhibition, and cytochrome c release was partially blocked by knockdown of CHOP. Finally, PBA significantly attenuated METH-induced sodium fluorescein (NaFluo) and Evans Blue leakage, as well as tight junction protein loss, in C57BL/6J mice. These data suggest that BBB endothelial cell damage was caused by METH-induced endoplasmic reticulum stress, which further induced mitochondrial dysfunction, and that PBA was an effective treatment for METH-induced BBB disruption. PMID:28959203

Photosynthetic induction and its diffusional, carboxylation and electron transport processes as affected by CO2 partial pressure, temperature, air humidity and blue irradiance.

PubMed

Kaiser, Elias; Kromdijk, Johannes; Harbinson, Jeremy; Heuvelink, Ep; Marcelis, Leo F M

2017-01-01

Plants depend on photosynthesis for growth. In nature, factors such as temperature, humidity, CO 2 partial pressure, and spectrum and intensity of irradiance often fluctuate. Whereas irradiance intensity is most influential and has been studied in detail, understanding of interactions with other factors is lacking. We tested how photosynthetic induction after dark-light transitions was affected by CO 2 partial pressure (20, 40, 80 Pa), leaf temperatures (15·5, 22·8, 30·5 °C), leaf-to-air vapour pressure deficits (VPD leaf-air ; 0·5, 0·8, 1·6, 2·3 kPa) and blue irradiance (0-20 %) in tomato leaves (Solanum lycopersicum). Rates of photosynthetic induction strongly increased with CO 2 partial pressure, due to increased apparent Rubisco activation rates and reduced diffusional limitations. High leaf temperature produced slightly higher induction rates, and increased intrinsic water use efficiency and diffusional limitation. High VPD leaf-air slowed down induction rates and apparent Rubisco activation and (at 2·3 kPa) induced damped stomatal oscillations. Blue irradiance had no effect. Slower apparent Rubisco activation in elevated VPD leaf-air may be explained by low leaf internal CO 2 partial pressure at the beginning of induction. The environmental factors CO 2 partial pressure, temperature and VPD leaf-air had significant impacts on rates of photosynthetic induction, as well as on underlying diffusional, carboxylation and electron transport processes. Furthermore, maximizing Rubisco activation rates would increase photosynthesis by at most 6-8 % in ambient CO 2 partial pressure (across temperatures and humidities), while maximizing rates of stomatal opening would increase photosynthesis by at most 1-3 %. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Antagonistic effects of acetylshikonin on LPS-induced NO and PGE2 production in BV2 microglial cells via inhibition of ROS/PI3K/Akt-mediated NF-κB signaling and activation of Nrf2-dependent HO-1.

PubMed

Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Lee, Kyoung-Tae; Choi, Yung Hyun; Moon, Sung-Kwon; Kim, Wun-Jae; Kim, Gi-Young

2015-10-01

Although acetylshikonin (ACS) is known to have antioxidant and antitumor activities, whether ACS regulates the expression of proinflammatory mediators in lipopolysaccharide (LPS)-stimulated microglial cells remains unclear. In this study, it was found that ACS isolated from Lithospermum erythrorhizon inhibits LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) release by suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in BV2 microglial cells. Furthermore, ACS reduced the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) and subsequently suppressed iNOS and COX-2 expression. Consistent with these data, ACS attenuated the phosphorylation of PI3K and Akt and suppressed the DNA-binding activity of NF-κB by inducing the generation of reactive oxygen species (ROS) in LPS-stimulated cells. In addition, ACS enhanced heme oxygenase-1 (HO-1) expression via nuclear factor-erythroid 2-related factor 2 (Nrf2) activation. Zinc protoporphyrin, a specific HO-1 inhibitor, partially attenuated the antagonistic effects of ACS on LPS-induced NO and PGE2 production. By contrast, the presence of cobalt protoporphyrin, a specific HO-1 inducer, potently suppressed LPS-induced NO and PGE2 production. These data indicate that ACS downregulates proinflammatory mediators such as NO and PGE2 by suppressing PI3K/Akt-dependent NF-κB activity induced by ROS as well as inducing Nrf2-dependent HO-1 activity. Taken together, ACS might be a good candidate to regulate LPS-mediated inflammatory diseases.

Prior exposure to repeated immobilization or chronic unpredictable stress protects from some negative sequels of an acute immobilization.

PubMed

Pastor-Ciurana, Jordi; Rabasa, Cristina; Ortega-Sánchez, Juan A; Sanchís-Ollè, Maria; Gabriel-Salazar, Marina; Ginesta, Marta; Belda, Xavier; Daviu, Núria; Nadal, Roser; Armario, Antonio

2014-05-15

Exposure to chronic unpredictable stress (CUS) is gaining acceptance as a putative animal model of depression. However, there is evidence that chronic exposure to stress can offer non-specific stress protection from some effects of acute superimposed stressors. We then compared in adult male rats the protection afforded by prior exposure to CUS with the one offered by repeated immobilization on boards (IMO) regarding some of the negative consequences of an acute exposure to IMO. Repeated exposure to IMO protected from the negative consequences of an acute IMO on activity in an open-field, saccharin intake and body weight gain. Active coping during IMO (struggling) was markedly reduced by repeated exposure to the same stressor, but it was not affected by a prior history of CUS, suggesting that our CUS protocol does not appear to impair active coping responses. CUS exposure itself caused a strong reduction of activity in the open-field but appeared to protect from the hypo-activity induced by acute IMO. Moreover, prior CUS offered partial protection from acute IMO-induced reduction of saccharin intake and body weight gain. It can be concluded that a prior history of CUS protects from some of the negative consequences of exposure to a novel severe stressor, suggesting the development of partial cross-adaptation whose precise mechanisms remain to be studied. Copyright © 2014 Elsevier B.V. All rights reserved.

High-frequency stimulation of the subthalamic nucleus restores neural and behavioral functions during reaction time task in a rat model of Parkinson's disease.

PubMed

Li, Xiang-Hong; Wang, Jin-Yan; Gao, Ge; Chang, Jing-Yu; Woodward, Donald J; Luo, Fei

2010-05-15

Deep brain stimulation (DBS) has been used in the clinic to treat Parkinson's disease (PD) and other neuropsychiatric disorders. Our previous work has shown that DBS in the subthalamic nucleus (STN) can improve major motor deficits, and induce a variety of neural responses in rats with unilateral dopamine (DA) lesions. In the present study, we examined the effect of STN DBS on reaction time (RT) performance and parallel changes in neural activity in the cortico-basal ganglia regions of partially bilateral DA- lesioned rats. We recorded neural activity with a multiple-channel single-unit electrode system in the primary motor cortex (MI), the STN, and the substantia nigra pars reticulata (SNr) during RT test. RT performance was severely impaired following bilateral injection of 6-OHDA into the dorsolateral part of the striatum. In parallel with such behavioral impairments, the number of responsive neurons to different behavioral events was remarkably decreased after DA lesion. Bilateral STN DBS improved RT performance in 6-OHDA lesioned rats, and restored operational behavior-related neural responses in cortico-basal ganglia regions. These behavioral and electrophysiological effects of DBS lasted nearly an hour after DBS termination. These results demonstrate that a partial DA lesion-induced impairment of RT performance is associated with changes in neural activity in the cortico-basal ganglia circuit. Furthermore, STN DBS can reverse changes in behavior and neural activity caused by partial DA depletion. The observed long-lasting beneficial effect of STN DBS suggests the involvement of the mechanism of neural plasticity in modulating cortico-basal ganglia circuits. (c) 2009 Wiley-Liss, Inc.

Vitamin-E reduces the oxidative damage on delta-aminolevulinic dehydratase induced by lead intoxication in rat erythrocytes.

PubMed

Rendón-Ramirez, A; Cerbón-Solórzano, J; Maldonado-Vega, M; Quintanar-Escorza, M A; Calderón-Salinas, J V

2007-09-01

Lead intoxication induces oxidative damage on lipids and proteins. In the present paper we study in vivo and in vitro the antioxidant effect of vitamin-E and trolox, on the oxidative effects of lead intoxication in rat erythrocytes. Vitamin-E simultaneously administered to erythrocytes treated with lead was capable to prevent the inhibition of delta-aminolevulinic dehydratase activity and lipid oxidation. Partial but important protective effects were found when vitamin-E was administered either after or before lead exposure in rats. In vitro, the antioxidant trolox protected delta-ALA-D activity against damage induced by lead or menadione. These results indicate that vitamin-E could be useful in order to protect membrane-lipids and, notably, to prevent protein oxidation produced by lead intoxication.

Discovery of novel brain permeable and G protein-biased beta-1 adrenergic receptor partial agonists for the treatment of neurocognitive disorders

PubMed Central

Yi, Bitna; Jahangir, Alam; Evans, Andrew K.; Briggs, Denise; Ravina, Kristine; Ernest, Jacqueline; Farimani, Amir B.; Sun, Wenchao; Rajadas, Jayakumar; Green, Michael; Feinberg, Evan N.; Pande, Vijay S.

2017-01-01

The beta-1 adrenergic receptor (ADRB1) is a promising therapeutic target intrinsically involved in the cognitive deficits and pathological features associated with Alzheimer’s disease (AD). Evidence indicates that ADRB1 plays an important role in regulating neuroinflammatory processes, and activation of ADRB1 may produce neuroprotective effects in neuroinflammatory diseases. Novel small molecule modulators of ADRB1, engineered to be highly brain permeable and functionally selective for the G protein with partial agonistic activity, could have tremendous value both as pharmacological tools and potential lead molecules for further preclinical development. The present study describes our ongoing efforts toward the discovery of functionally selective partial agonists of ADRB1 that have potential therapeutic value for AD and neuroinflammatory disorders, which has led to the identification of the molecule STD-101-D1. As a functionally selective agonist of ADRB1, STD-101-D1 produces partial agonistic activity on G protein signaling with an EC50 value in the low nanomolar range, but engages very little beta-arrestin recruitment compared to the unbiased agonist isoproterenol. STD-101-D1 also inhibits the tumor necrosis factor α (TNFα) response induced by lipopolysaccharide (LPS) both in vitro and in vivo, and shows high brain penetration. Other than the therapeutic role, this newly identified, functionally selective, partial agonist of ADRB1 is an invaluable research tool to study mechanisms of G protein-coupled receptor signal transduction. PMID:28746336

Discovery of novel brain permeable and G protein-biased beta-1 adrenergic receptor partial agonists for the treatment of neurocognitive disorders.

PubMed

Yi, Bitna; Jahangir, Alam; Evans, Andrew K; Briggs, Denise; Ravina, Kristine; Ernest, Jacqueline; Farimani, Amir B; Sun, Wenchao; Rajadas, Jayakumar; Green, Michael; Feinberg, Evan N; Pande, Vijay S; Shamloo, Mehrdad

2017-01-01

The beta-1 adrenergic receptor (ADRB1) is a promising therapeutic target intrinsically involved in the cognitive deficits and pathological features associated with Alzheimer's disease (AD). Evidence indicates that ADRB1 plays an important role in regulating neuroinflammatory processes, and activation of ADRB1 may produce neuroprotective effects in neuroinflammatory diseases. Novel small molecule modulators of ADRB1, engineered to be highly brain permeable and functionally selective for the G protein with partial agonistic activity, could have tremendous value both as pharmacological tools and potential lead molecules for further preclinical development. The present study describes our ongoing efforts toward the discovery of functionally selective partial agonists of ADRB1 that have potential therapeutic value for AD and neuroinflammatory disorders, which has led to the identification of the molecule STD-101-D1. As a functionally selective agonist of ADRB1, STD-101-D1 produces partial agonistic activity on G protein signaling with an EC50 value in the low nanomolar range, but engages very little beta-arrestin recruitment compared to the unbiased agonist isoproterenol. STD-101-D1 also inhibits the tumor necrosis factor α (TNFα) response induced by lipopolysaccharide (LPS) both in vitro and in vivo, and shows high brain penetration. Other than the therapeutic role, this newly identified, functionally selective, partial agonist of ADRB1 is an invaluable research tool to study mechanisms of G protein-coupled receptor signal transduction.

The effects of centrally injected arachidonic acid on respiratory system: Involvement of cyclooxygenase to thromboxane signaling pathway.

PubMed

Erkan, Leman Gizem; Guvenc, Gokcen; Altinbas, Burcin; Niaz, Nasir; Yalcin, Murat

2016-05-01

Arachidonic acid (AA) is a polyunsaturated fatty acid that is present in the phospholipids of the cell membranes of the body and is abundant in the brain. Exogenously administered AA has been shown to affect brain metabolism and to exhibit cardiovascular and neuroendocrine actions. However, little is known regarding its respiratory actions and/or central mechanism of its respiratory effects. Therefore, the present study was designed to investigate the possible effects of centrally injected AA on respiratory system and the mediation of the central cyclooxygenase (COX) to thromboxane A2 (TXA2) signaling pathway on AA-induced respiratory effects in anaesthetized rats. Intracerebroventricular (i.c.v.) administration of AA induced dose- and time-dependent increase in tidal volume, respiratory rates and respiratory minute ventilation and also caused an increase in partial oxygen pressure (pO2) and decrease in partial carbon dioxide pressure (pCO2) in male anaesthetized Spraque Dawley rats. I.c.v. pretreatment with ibuprofen, a non-selective COX inhibitor, completely blocked the hyperventilation and blood gases changes induced by AA. In addition, central pretreatment with different doses of furegrelate, a TXA2 synthesis inhibitor, also partially prevented AA-evoked hyperventilation and blood gases effects. These data explicitly show that centrally administered AA induces hyperventilation with increasing pO2 and decreasing pCO2 levels which are mediated by the activation of central COX to TXA2 signaling pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

[GABA-NO interaction in the N. Accumbens during danger-induced inhibition of exploratory behavior].

PubMed

Saul'skaia, N V; Terekhova, E A

2013-01-01

In Sprague-Dawley rats by means of in vivo microdialysis combined with HPLC analysis, it was shown that presentation to rats during exploratory activity of a tone previously pared with footshock inhibited the exploration and prevented the exploration-induced increase in extracellular levels of citrulline (an NO co-product) in the medial n. accumbens. Intra-accumbal infusions of 20 μM bicuculline, a GABA(A)-receptor antagonist, firstly, partially restored the exploration-induced increase of extracellular citrulline levels in this brain area, which was inhibited by presentation of the tone, previously paired with foot-shock and, secondly, prevented the inhibition of exploratory behavior produced by this sound signal of danger. The data obtained indicate for the first time that signals of danger inhibit exploratory behavior and exploration-induced activation of the accumbal nitrergic system via GABA(A)-receptor mechanisms.

Activation of autophagy by unfolded proteins during endoplasmic reticulum stress.

PubMed

Yang, Xiaochen; Srivastava, Renu; Howell, Stephen H; Bassham, Diane C

2016-01-01

Endoplasmic reticulum stress is defined as the accumulation of unfolded proteins in the endoplasmic reticulum, and is caused by conditions such as heat or agents that cause endoplasmic reticulum stress, including tunicamycin and dithiothreitol. Autophagy, a major pathway for degradation of macromolecules in the vacuole, is activated by these stress agents in a manner dependent on inositol-requiring enzyme 1b (IRE1b), and delivers endoplasmic reticulum fragments to the vacuole for degradation. In this study, we examined the mechanism for activation of autophagy during endoplasmic reticulum stress in Arabidopsis thaliana. The chemical chaperones sodium 4-phenylbutyrate and tauroursodeoxycholic acid were found to reduce tunicamycin- or dithiothreitol-induced autophagy, but not autophagy caused by unrelated stresses. Similarly, over-expression of BINDING IMMUNOGLOBULIN PROTEIN (BIP), encoding a heat shock protein 70 (HSP70) molecular chaperone, reduced autophagy. Autophagy activated by heat stress was also found to be partially dependent on IRE1b and to be inhibited by sodium 4-phenylbutyrate, suggesting that heat-induced autophagy is due to accumulation of unfolded proteins in the endoplasmic reticulum. Expression in Arabidopsis of the misfolded protein mimics zeolin or a mutated form of carboxypeptidase Y (CPY*) also induced autophagy in an IRE1b-dependent manner. Moreover, zeolin and CPY* partially co-localized with the autophagic body marker GFP-ATG8e, indicating delivery to the vacuole by autophagy. We conclude that accumulation of unfolded proteins in the endoplasmic reticulum is a trigger for autophagy under conditions that cause endoplasmic reticulum stress. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

[Antimutagenic action of superoxide dismutase on sodium azide- and nitrosoguanidine-induced mutagenesis in Salmonella typhimurium TA 1535].

PubMed

Vorob'eva, L I; Cherdyntseva, T A; Aver'ianov, A A; Abilev, S K

1993-05-01

It was shown that superoxide dismutase (SOD) decreased the mutagenic action of sodium azide (NaN3) and N-methyl-N'-nitro-N-nitrosoguanidine in Salmonella typhimurium TA1535. Catalase and quenchers of hydroxyl radicals showed, unlike SOD no effect on the mutagenicity of NaN3. Cell extract from propionic acid bacteria also possessed the antimutagenic activity, only partially depending on the SOD activity.

Nell-1, a key Functional Mediator of Runx2, Partially Rescues Calvarial Defects in Runx2+/− Mice

PubMed Central

Zhang, Xinli; Ting, Kang; Bessette, Catherine M; Culiat, Cymbeline T; Sung, Sang Jin; Lee, Haofu; Chen, Feng; Shen, Jia; Wang, James J; Kuroda, Shun'ichi; Soo, Chia

2011-01-01

Mesenchymal stem cell commitment to an osteoprogenitor lineage requires the activity of Runx2, a molecule implicated in the etiopathology of multiple congenital craniofacial anomalies. Through promoter analyses, we have recently identified a new direct transcriptional target of Runx2, Nell-1, a craniosynostosis (CS)–associated molecule with potent osteogenic properties. This study investigated the mechanistic and functional relationship between Nell-1 and Runx2 in regulating osteoblast differentiation. The results showed that spatiotemporal distribution and expression levels of Nell-1 correlated closely with those of endogenous Runx2 during craniofacial development. Phenotypically, cross-mating Nell-1 overexpression transgenic (CMV-Nell-1) mice with Runx2 haploinsufficient (Runx2+/−) mice partially rescued the calvarial defects in the cleidocranial dysplasia (CCD)–like phenotype of Runx2+/− mice, whereas Nell-1 protein induced mineralization and bone formation in Runx2+/− but not Runx2−/− calvarial explants. Runx2-mediated osteoblastic gene expression and/or mineralization was severely reduced by Nell-1 siRNA oligos transfection into Runx2+/+ newborn mouse calvarial cells (NMCCs) or in N-ethyl-N-nitrosourea (ENU)–induced Nell-1−/− NMCCs. Meanwhile, Nell-1 overexpression partially rescued osteoblastic gene expression but not mineralization in Runx2 null (Runx2−/−) NMCCs. Mechanistically, irrespective of Runx2 genotype, Nell-1 signaling activates ERK1/2 and JNK1 mitogen-activated protein kinase (MAPK) pathways in NMCCs and enhances Runx2 phosphorylation and activity when Runx2 is present. Collectively, these data demonstrate that Nell-1 is a critical downstream Runx2 functional mediator insofar as Runx2-regulated Nell-1 promotes osteoblastic differentiation through, in part, activation of MAPK and enhanced phosphorylation of Runx2, and Runx2 activity is significantly reduced when Nell-1 is blocked or absent. © 2011 American Society for Bone and Mineral Research. PMID:20939017

Unique spectrum of activity of 9-[(1,3-dihydroxy-2-propoxy)methyl]-guanine against herpesviruses in vitro and its mode of action against herpes simplex virus type 1.

PubMed Central

Cheng, Y C; Huang, E S; Lin, J C; Mar, E C; Pagano, J S; Dutschman, G E; Grill, S P

1983-01-01

A guanosine analog, 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (DHPG), was found to inhibit herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2, cytomegalovirus, and Epstein-Barr virus replication by greater than 50% at concentrations that do not inhibit cell growth in culture. The potency of the drug against all of these viruses is greater than that of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir). DHPG was active against HSV-1 growth during the early phase of virus replication and had no activity when added at a later time after infection. Its antiviral activity was irreversible. Thymidine partially neutralized its action. The anti-HSV-1 activity of DHPG was dependent on the induction and the properties of virus-induced thymidine kinase. Virus variants that induced altered virus thymidine kinase and became resistant to acyclovir were still as sensitive to DHPG as the parental virus. DHPG is active against five different HSV variants with induced altered DNA polymerase and resistance to acyclovir. PMID:6302704

Visible-Light-Induced Bactericidal Activity of a Nitrogen-Doped Titanium Photocatalyst against Human Pathogens

PubMed Central

Wong, Ming-Show; Chu, Wen-Chen; Sun, Der-Shan; Huang, Hsuan-Shun; Chen, Jiann-Hwa; Tsai, Pei-Jane; Lin, Nien-Tsung; Yu, Mei-Shiuan; Hsu, Shang-Feng; Wang, Shih-Lien; Chang, Hsin-Hou

2006-01-01

The antibacterial activity of photocatalytic titanium dioxide (TiO2) substrates is induced primarily by UV light irradiation. Recently, nitrogen- and carbon-doped TiO2 substrates were shown to exhibit photocatalytic activities under visible-light illumination. Their antibacterial activity, however, remains to be quantified. In this study, we demonstrated that nitrogen-doped TiO2 substrates have superior visible-light-induced bactericidal activity against Escherichia coli compared to pure TiO2 and carbon-doped TiO2 substrates. We also found that protein- and light-absorbing contaminants partially reduce the bactericidal activity of nitrogen-doped TiO2 substrates due to their light-shielding effects. In the pathogen-killing experiment, a significantly higher proportion of all tested pathogens, including Shigella flexneri, Listeria monocytogenes, Vibrio parahaemolyticus, Staphylococcus aureus, Streptococcus pyogenes, and Acinetobacter baumannii, were killed by visible-light-illuminated nitrogen-doped TiO2 substrates than by pure TiO2 substrates. These findings suggest that nitrogen-doped TiO2 has potential application in the development of alternative disinfectants for environmental and medical usages. PMID:16957236

Activation of G protein-coupled estrogen receptor 1 induces coronary artery relaxation via Epac/Rap1-mediated inhibition of RhoA/Rho kinase pathway in parallel with PKA.

PubMed

Yu, Xuan; Zhang, Qiao; Zhao, Yan; Schwarz, Benjamin J; Stallone, John N; Heaps, Cristine L; Han, Guichun

2017-01-01

Previously, we reported that cAMP/PKA signaling is involved in GPER-mediated coronary relaxation by activating MLCP via inhibition of RhoA pathway. In the current study, we tested the hypothesis that activation of GPER induces coronary artery relaxation via inhibition of RhoA/Rho kinase pathway by cAMP downstream targets, exchange proteins directly activated by cAMP (Epac) as well as PKA. Our results show that Epac inhibitors, brefeldin A (BFA, 50 μM), or ESI-09 (20 μM), or CE3F4 (100 μM), all partially inhibited porcine coronary artery relaxation response to the selective GPER agonist, G-1 (0.3-3 μM); while concurrent administration of BFA and PKI (5 μM), a PKA inhibitor, almost completely blocked the relaxation effect of G-1. The Epac specific agonist, 8-CPT-2Me-cAMP (007, 1-100 μM), induced a concentration-dependent relaxation response. Furthermore, the activity of Ras-related protein 1 (Rap1) was up regulated by G-1 (1 μM) treatment of porcine coronary artery smooth muscle cells (CASMCs). Phosphorylation of vasodilator-stimulated phosphoprotein (p-VASP) was elevated by G-1 (1 μM) treatment, but not by 007 (50 μM); and the effect of G-1 on p-VASP was blocked by PKI, but not by ESI-09, an Epac antagonist. RhoA activity was similarly down regulated by G-1 and 007, whereas ESI-09 restored most of the reduced RhoA activity by G-1 treatment. Furthermore, G-1 decreased PGF2α-induced p-MYPT1, which was partially reversed with either ESI-09 or PKI; whereas, concurrent administration of ESI-09 and PKI totally prevented the inhibitory effect of G-1. The inhibitory effects of G-1 on p- MLC levels in CASMCs were mostly restored by either ESI-09 or PKI. These results demonstrate that activation of GPER induces coronary artery relaxation via concurrent inhibition of RhoA/Rho kinase by Epac/Rap1 and PKA. GPER could be a potential drug target for preventing and treating cardiovascular diseases.

Antinociceptive, anti-inflammatory and antiarthritic activities of Bungarus fasciatus venom in experimental animal models.

PubMed

Ghosh, Susmita; Saha, Partha Pratim; Dasgupta, Subir C; Gomes, Antony

2016-09-01

Pain and inflammation are intimately associated with rheumatoid arthritis, a growing bone-joint related problem of the modern society. Though several therapeutic managements are available for arthritis, their side effects not only limit their use, but also advocate the quest for natural therapies. In this study, we explored the antinociceptive, anti-inflammatory and antiarthritic activities of Bungarus fasciatus venom (BFV) in experimental animal models. Rheumatoid arthritis was induced by Freund’s complete adjuvant (FCA) in male Wistar albino rats. Lyophilized BFV was diluted in 0.9% NaCl. Antiarthritic activity showed that BFV significantly reduced the paw and ankle diameters; urinary hydroxyproline, glucosamine levels and serum ACP/ALP/TNF-α/IL-1β/IL-17/Cathepsin-K/MMP-1 levels. These parameters were significantly increased in FCA induced arthritic animals. Joint histopathology study indicated the partial restoration of joint structure. Treatment with BFV significantly reduced the mean latency time of tail flick response, acetic acid induced writhing response and formalin induced licking response in male albino mice. BFV treatment also significantly reduced carrageenan induced paw edema and xylene induced ear edema in male albino mice. The results indicated that BFV possess antinociceptive, anti-inflammatory and antiarthritic properties and further studies are warranted to find the active constituents present in BFV.

Oxidative stress-driven mechanisms of nordihydroguaiaretic acid-induced apoptosis in FL5.12 cells

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

Deshpande, Vaidehee S.; Kehrer, James P.

2006-08-01

Nordihydroguaiaretic acid (NDGA), a general lipoxygenase (LOX) enzyme inhibitor, induces apoptosis independently of its activity as a LOX inhibitor in murine pro-B lymphocytes (FL.12 cells) by a mechanism that is still not fully understood. Glutathione depletion, oxidative processes and mitochondrial depolarization appear to contribute to the apoptosis induced by NDGA. The current data demonstrate that NDGA (20 {mu}M)-induced apoptosis in FL5.12 cells is partially protected by N-acetylcysteine (NAC) (10 mM) and dithiothreitol (DTT) (500 {mu}M) pretreatment, confirming a role for oxidative processes. In addition, the treatment of FL5.12 cells with NDGA led to an increase in phosphorylation and activation ofmore » the MAP kinases ERK, JNK and p38. Although pretreatment with ERK inhibitors (PD98059 or U0126) abolished ERK phosphorylation in response to NDGA, neither inhibitor had any effect on NDGA-induced apoptosis. SP600125, a JNK inhibitor, did not have any effect on NDGA-induced phosphorylation of JNK nor apoptosis. Pretreatment with the p38 inhibitor SB202190 attenuated NDGA-induced apoptosis by 30% and also abolished p38 phosphorylation, compared to NDGA treatment alone. NAC, but not DTT, also decreased the phosphorylation of p38 and JNK supporting a role for oxidative processes in activating these kinases. Neither NAC nor DTT blocked the phosphorylation of ERK suggesting that this activation is not related to oxidative stress. The release of cytochrome c and activation of caspase-3 induced by NDGA were inhibited by NAC. SB202190 slightly attenuated caspase-3 activation and had no effect on the release of cytochrome c. These data suggest that several independent mechanisms, including oxidative reactions, activation of p38 kinase and cytochrome c release contribute to NDGA-induced apoptosis.« less

Role of mitogen-activated protein kinases and Mcl-1 in apoptosis induction by withaferin A in human breast cancer cells.

PubMed

Hahm, Eun-Ryeong; Lee, Joomin; Singh, Shivendra V

2014-11-01

Withaferin A (WA), a bioactive constituent of Ayurvedic medicine plant Withania somnifera, is a potent apoptosis inducer in cancer cells but the mechanism of cell death induction is not fully characterized. The present study was undertaken to determine the role of mitogen-activated protein kinases (MAPK), including c-jun NH2 -terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38 MAPK, and anti-apoptotic protein myeloid cell leukemia-1 (Mcl-1) in regulation of WA-induced apoptosis using human breast cancer cells. Exposure of MCF-7 (estrogen responsive) and SUM159 (triple negative) human breast cancer cells to WA resulted in increased phosphorylation of ERK, JNK, and p38 MAPK, but these effects were relatively more pronounced in the former cell line than in SUM159. Overexpression of manganese-superoxide dismutase conferred partial protection against WA-mediated hyperphosphorylation of ERK, but not JNK or p38 MAPK. Cell death resulting from WA treatment in MCF-7 cells was significantly augmented by pharmacological inhibition of ERK and p38 MAPK. Interestingly, the WA-induced apoptosis in MCF-7 cells was partially but significantly blocked in the presence of a JNK-specific inhibitor. Pharmacological inhibition of ERK or JNK had no effect on WA-induced apoptosis in SUM159 cells. The WA-treated cells exhibited induction of long and short forms of Mcl-1. RNA interference of Mcl-1 alone triggered apoptosis. Furthermore, the WA-induced cell death in MCF-7 cells was modestly but significantly augmented by knockdown of the Mcl-1 protein. These observations indicate that: MAPK have cell line-specific role in cell death by WA, and Mcl-1 induction confers modest protection against WA-induced apoptosis. © 2013 Wiley Periodicals, Inc.

Role of Akt and Ca2+ on cell permeabilization via connexin43 hemichannels induced by metabolic inhibition.

PubMed

Salas, Daniela; Puebla, Carlos; Lampe, Paul D; Lavandero, Sergio; Sáez, Juan C

2015-07-01

Connexin hemichannels are regulated under physiological and pathological conditions. Metabolic inhibition, a model of ischemia, promotes surface hemichannel activation associated, in part, with increased surface hemichannel levels, but little is known about its underlying mechanism. Here, we investigated the role of Akt on the connexin43 hemichannel's response induced by metabolic inhibition. In HeLa cells stably transfected with rat connexin43 fused to EGFP (HeLa43 cells), metabolic inhibition induced a transient Akt activation necessary to increase the amount of surface connexin43. The increase in levels of surface connexin43 was also found to depend on an intracellular Ca2+ signal increase that was partially mediated by Akt activation. However, the metabolic inhibition-induced Akt activation was not significantly affected by intracellular Ca2+ chelation. The Akt-dependent increase in connexin43 hemichannel activity in HeLa43 cells also occurred after oxygen-glucose deprivation, another ischemia-like condition, and in cultured cortical astrocytes (endogenous connexin43 expression system) under metabolic inhibition. Since opening of hemichannels has been shown to accelerate cell death, inhibition of Akt-dependent phosphorylation of connexin43 hemichannels could reduce cell death induced by ischemia/reperfusion. Copyright © 2015 Elsevier B.V. All rights reserved.

Activation of Strychnine-Sensitive Glycine Receptors by Shilajit on Preoptic Hypothalamic Neurons of Juvenile Mice.

PubMed

Bhattarai, Janardhan Prasad; Cho, Dong Hyu; Han, Seong Kyu

2016-02-29

Shilajit, a mineral pitch, has been used in Ayurveda and Siddha system of medicine to treat many human ailments, and is reported to contain at least 85 minerals in ionic form. This study examined the possible mechanism of Shilajit action on preoptic hypothalamic neurons using juvenile mice. The hypothalamic neurons are the key regulator of many hormonal systems. In voltage clamp mode at a holding potential of -60 mV, and under a high chloride pipette solution, Shilajit induced dose-dependent inward current. Shilajit-induced inward currents were reproducible and persisted in the presence of 0.5 μM tetrodotoxin (TTX) suggesting a postsynaptic action of Shilajit on hypothalamic neurons. The currents induced by Shilajit were almost completely blocked by 2 μM strychnine (Stry), a glycine receptor antagonist. In addition, Shilajit-induced inward currents were partially blocked by bicuculline. Under a gramicidin-perforated patch clamp mode, Shilajit induced membrane depolarization on juvenile neurons. These results show that Shilajit affects hypothalamic neuronal activities by activating the Stry-sensitive glycine receptor with α₂/α₂β subunit. Taken together, these results suggest that Shilajit contains some ingredients with possible glycine mimetic activities and might influence hypothalamic neurophysiology through activation of Stry-sensitive glycine receptor-mediated responses on hypothalamic neurons postsynaptically.

Mitochondria related peptide MOTS-c suppresses ovariectomy-induced bone loss via AMPK activation

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

Ming, Wei, E-mail: weiming@xiyi.edu.cn; Department of Pharmacology, Xi’an Medical University, Xi’an 710021; Lu, Gan, E-mail: leonming99@163.com

Therapeutic targeting bone loss has been the focus of the study in osteoporosis. The present study is intended to evaluate whether MOTS-c, a novel mitochondria related 16 aa peptide, can protect mice from ovariectomy-induced osteoporosis. After ovary removal, the mice were injected with MOTS-c at a dose of 5 mg/kg once a day for 12 weeks. Our results showed that MOTS-c treatment significantly alleviated bone loss, as determined by micro-CT examination. Mechanistically, we found that the receptor activator of nuclear factor-κB ligand (RANKL) induced osteoclast differentiation was remarkably inhibited by MOTS-c. Moreover, MOTS-c increased phosphorylated AMPK levels, and compound C, anmore » AMPK inhibitor, could partially abrogate the effects of the MOTS-c on osteoclastogenesis. Thus, our findings provide evidence that MOTS-c may exert as an inhibitor of osteoporosis via AMPK dependent inhibition of osteoclastogenesis. -- Highlights: •MOTS-c decreases OVX-induced bone loss in vivo. •MOTS-c inhibits RANKL-induced osteoclast formation. •MOTS-c inhibits RANKL-induced osteoclast-specific gene expression. •MOTS-c represses osteoclast differentiation via the activation of AMPK.« less

Perflurooctanoic Acid Induces Developmental Cardiotoxicity in ...

EPA Pesticide Factsheets

Perfluorooctanoic acid (PFOA) is a widespread environmental contaminant that is detectable in serum of the general U.S. population. PFOA is a known developmental toxicant that induces mortality in mammalian embryos and is thought to induce toxicity via interaction with the peroxisome proliferator activated receptor alpha (PPAR_). As the cardiovascular system is crucial for embryonic survival, PFOA-induced effects on the heart may partially explain embryonic mortality. To assess impacts of PFOA exposure on the developing heart in an avian model, we used histopathology and immunohistochemical staining for myosin to assess morphological alterations in 19-day-old chicken embryo hearts after PFOA exposure. Additionally, echocardiography and cardiac myofibril ATPase activity assays were used to assess functional alterations in 1-day-old hatchling chickens following developmental PFOA exposure. Overall thinning and thinning of a dense layer of myosin in the right ventricular wall were observed in PFOA-exposed chicken embryo hearts. Alteration of multiple cardiac structural and functional parameters, including left ventricular wall thickness, left ventricular volume, heart rate, stroke volume, and ejection fraction were detected with echocardiography in the exposed hatchling chickens. Assessment of ATPase activity indicated that the ratio of cardiac myofibril calcium-independent ATPase activity to calcium-dependent ATPase activity was not affected, which suggests that d

Rosiglitazone Suppresses In Vitro Seizures in Hippocampal Slice by Inhibiting Presynaptic Glutamate Release in a Model of Temporal Lobe Epilepsy.

PubMed

Wong, Shi-Bing; Cheng, Sin-Jhong; Hung, Wei-Chen; Lee, Wang-Tso; Min, Ming-Yuan

2015-01-01

Peroxisomal proliferator-activated receptor gamma (PPARγ) is a nuclear hormone receptor whose agonist, rosiglitazone has a neuroprotective effect to hippocampal neurons in pilocarpine-induced seizures. Hippocampal slice preparations treated in Mg2+ free medium can induce ictal and interictal-like epileptiform discharges, which is regarded as an in vitro model of N-methyl-D-aspartate (NMDA) receptor-mediated temporal lobe epilepsy (TLE). We applied rosiglitazone in hippocampal slices treated in Mg2+ free medium. The effects of rosiglitazone on hippocampal CA1-Schaffer collateral synaptic transmission were tested. We also examined the neuroprotective effect of rosiglitazone toward NMDA excitotoxicity on cultured hippocampal slices. Application of 10 μM rosiglitazone significantly suppressed amplitude and frequency of epileptiform discharges in CA1 neurons. Pretreatment with the PPARγ antagonist GW9662 did not block the effect of rosiglitazone on suppressing discharge frequency, but reverse the effect on suppressing discharge amplitude. Application of rosiglitazone suppressed synaptic transmission in the CA1-Schaffer collateral pathway. By miniature excitatory-potential synaptic current (mEPSC) analysis, rosiglitazone significantly suppressed presynaptic neurotransmitter release. This phenomenon can be reversed by pretreating PPARγ antagonist GW9662. Also, rosiglitazone protected cultured hippocampal slices from NMDA-induced excitotoxicity. The protective effect of 10 μM rosiglitazone was partially antagonized by concomitant high dose GW9662 treatment, indicating that this effect is partially mediated by PPARγ receptors. In conclusion, rosiglitazone suppressed NMDA receptor-mediated epileptiform discharges by inhibition of presynaptic neurotransmitter release. Rosiglitazone protected hippocampal slice from NMDA excitotoxicity partially by PPARγ activation. We suggest that rosiglitazone could be a potential agent to treat patients with TLE.

Modified rice bran hemicellulose inhibits vascular endothelial growth factor-induced angiogenesis in vitro via VEGFR2 and its downstream signaling pathways

PubMed Central

ZHU, Xia; OKUBO, Aya; IGARI, Naoki; NINOMIYA, Kentaro; EGASHIRA, Yukari

2016-01-01

Angiogenesis is implicated in diverse pathological conditions such as cancer, rheumatoid arthritis, psoriasis, atherosclerosis, and retinal neovascularization. In the present study, we investigated the effects of modified rice bran hemicellulose (MRBH), a water-soluble hemicellulose preparation from rice bran treated with shiitake enzymes, on vascular endothelial growth factor (VEGF)-induced angiogenesis in vitro and its mechanism. We found that MRBH significantly inhibited VEGF-induced tube formation in human umbilical vein endothelial cells (HUVECs) co-cultured with human dermal fibroblasts. We also observed that MRBH dose-dependently suppressed the VEGF-induced proliferation and migration of HUVECs. Furthermore, examination of the anti-angiogenic mechanism indicated that MRBH reduced not only VEGF-induced activation of VEGF receptor 2 but also of the downstream signaling proteins Akt, extracellular signal-regulated protein kinase 1/2, and p38 mitogen-activated protein kinase. These findings suggest that MRBH has in vitro anti-angiogenic effects that are partially mediated through the inhibition of VEGF signaling. PMID:28439487

Correction for Eddy Current-Induced Echo-Shifting Effect in Partial-Fourier Diffusion Tensor Imaging.

PubMed

Truong, Trong-Kha; Song, Allen W; Chen, Nan-Kuei

2015-01-01

In most diffusion tensor imaging (DTI) studies, images are acquired with either a partial-Fourier or a parallel partial-Fourier echo-planar imaging (EPI) sequence, in order to shorten the echo time and increase the signal-to-noise ratio (SNR). However, eddy currents induced by the diffusion-sensitizing gradients can often lead to a shift of the echo in k-space, resulting in three distinct types of artifacts in partial-Fourier DTI. Here, we present an improved DTI acquisition and reconstruction scheme, capable of generating high-quality and high-SNR DTI data without eddy current-induced artifacts. This new scheme consists of three components, respectively, addressing the three distinct types of artifacts. First, a k-space energy-anchored DTI sequence is designed to recover eddy current-induced signal loss (i.e., Type 1 artifact). Second, a multischeme partial-Fourier reconstruction is used to eliminate artificial signal elevation (i.e., Type 2 artifact) associated with the conventional partial-Fourier reconstruction. Third, a signal intensity correction is applied to remove artificial signal modulations due to eddy current-induced erroneous T2(∗) -weighting (i.e., Type 3 artifact). These systematic improvements will greatly increase the consistency and accuracy of DTI measurements, expanding the utility of DTI in translational applications where quantitative robustness is much needed.

Correction for Eddy Current-Induced Echo-Shifting Effect in Partial-Fourier Diffusion Tensor Imaging

PubMed Central

Truong, Trong-Kha; Song, Allen W.; Chen, Nan-kuei

2015-01-01

In most diffusion tensor imaging (DTI) studies, images are acquired with either a partial-Fourier or a parallel partial-Fourier echo-planar imaging (EPI) sequence, in order to shorten the echo time and increase the signal-to-noise ratio (SNR). However, eddy currents induced by the diffusion-sensitizing gradients can often lead to a shift of the echo in k-space, resulting in three distinct types of artifacts in partial-Fourier DTI. Here, we present an improved DTI acquisition and reconstruction scheme, capable of generating high-quality and high-SNR DTI data without eddy current-induced artifacts. This new scheme consists of three components, respectively, addressing the three distinct types of artifacts. First, a k-space energy-anchored DTI sequence is designed to recover eddy current-induced signal loss (i.e., Type 1 artifact). Second, a multischeme partial-Fourier reconstruction is used to eliminate artificial signal elevation (i.e., Type 2 artifact) associated with the conventional partial-Fourier reconstruction. Third, a signal intensity correction is applied to remove artificial signal modulations due to eddy current-induced erroneous T 2 ∗-weighting (i.e., Type 3 artifact). These systematic improvements will greatly increase the consistency and accuracy of DTI measurements, expanding the utility of DTI in translational applications where quantitative robustness is much needed. PMID:26413505

Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy.

PubMed

Zhang, Cong; Bélanger, Samuel; Pouliot, Philippe; Lesage, Frédéric

2015-01-01

In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.

Purification and general properties of pectin methyl esterase from Curvularia inaequalis NRRL 13884 in solid state culture using orange peels as an inducer.

PubMed

Afifi, A F; Fawzi, E M; Foaad, M A

2002-01-01

Pectin methyl esterase (PME) [E.C.3. 1.1.11] production by Curvularia inaequalis (Shear) Boedijn NRRL 13884 was investigated using solid-state culture. The highest level of extracellular pectin methyl esterase was detected with orange peels as an inducing substrate and as a sole carbon source. The enzyme was partially purified using Sephadex G-100 and DEAE-Cellulose column chromatography. It was purified about 40 fold with optimum activity at pH 4.4 and 45 degrees C. The enzyme was activated by Co++, Mg++, Na+, whereas it was slightly activated in the presence of Cu++, K+, Mn++, Zn++. On the other hand Ag++, Ca++ and Hg++ inhibited the activity of the enzyme. The Km was calculated to be 0.52 mM.

Effect of the 5-HT(1A) partial agonist buspirone on regional brain electrical activity in man: a functional neuroimaging study using low-resolution electromagnetic tomography (LORETA).

PubMed

Anderer, P; Saletu, B; Pascual-Marqui, R D

2000-12-04

In a double-blind, placebo-controlled study, the effects of 20 mg buspirone - a 5-HT(1A) partial agonist - on regional electrical generators within the human brain were investigated utilizing three-dimensional EEG tomography. Nineteen-channel vigilance-controlled EEG recordings were carried out in 20 healthy subjects before and 1, 2, 4, 6 and 8 h after drug intake. Low-resolution electromagnetic tomography (LORETA; Key Institute for Brain-Mind Research, software: http://www.keyinst.unizh.ch) was computed from spectrally analyzed EEG data, and differences between drug- and placebo-induced changes were displayed as statistical parametric maps. Data were registered to the Talairach-Tournoux human brain atlas available as a digitized MRI (McConnell Brain Imaging Centre: http://www.bic.mni.mcgill.ca). At the pharmacodynamic peak (1st hour), buspirone increased theta and decreased fast alpha and beta sources. Areas of theta increase were mainly the left temporo-occipito-parietal and left prefrontal cortices, which is consistent with PET studies on buspirone-induced decreases in regional cerebral blood flow and fenfluramine-induced serotonin activation demonstrated by changes in regional cerebral glucose metabolism. In later hours (8th hour) with lower buspirone plasma levels, delta, theta, slow alpha and fast beta decreased, predominantly in the prefrontal and anterior limbic lobe. Whereas the results of the 1st hour speak for a slight CNS sedation (more in the sense of relaxation), those obtained in the 8th hour indicate activation. Thus, LORETA may provide useful and direct information on drug-induced changes in central nervous system function in man.

Time-dependent effect of rutin on skin fibroblasts membrane disruption following UV radiation.

PubMed

Gęgotek, Agnieszka; Bielawska, Katarzyna; Biernacki, Michał; Dobrzyńska, Izabela; Skrzydlewska, Elżbieta

2017-08-01

Chronic exposure of the skin to solar UV radiation induces a number of biological alterations, including a redox imbalance; therefore, there is an urgent need for skin cells protective compounds. The aim of this study was to determine the effects of natural, previously extensively examined, polyphenol with antioxidant properties - rutin, on UV-induced skin fibroblasts membrane disruption. Accordingly, fibroblasts exposed to UVA and UVB irradiation were incubated with rutin (12h before and/or up to 24h after irradiation), and the structural and metabolic changes were examined. Rutin penetration through the fibroblast phospholipid bilayer was aided by UVA-induced bilitranslocase activity 2-4h after irradiation, while UVB irradiation led to enhanced phospholipid peroxidation and higher membrane permeability to facilitate the interaction of rutin with phospholipids. Lipidomic analysis revealed that 4h of rutin treatment also partially prevented UVA/B-induced increase in phosphatidylethanolamine and phosphatidylcholine level, as well as their membrane localization, which resulted in an enhanced zeta potential in the cells and liposomes. Moreover, rutin 2h following irradiation, in a various degree, prevented the increased in phospholipase A2 activity and ROS generation, and partially protected against the reduction of arachidonic and linoleic acids level and the lipid peroxidation product 4-hydroxynonenal level increase. Rutin effectively prevented against decrease in glutathione peroxidase, glutathione and vitamins E and C activities/levels, particularly 2h following UVA irradiation. In conclusion, highest skin fibroblasts membrane level of rutin occurred in 2-4h following UVA/B-radiation results in its strongest effect on biomembrane structure and functions and cellular antioxidant system irrespective of the radiation type. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of fraxetin on antioxidant defense and stress proteins in human neuroblastoma cell model of rotenone neurotoxicity. Comparative study with myricetin and N-acetylcysteine

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

Molina-Jimenez, Maria Francisca; Sanchez-Reus, Maria Isabel; Cascales, Maria

2005-12-15

Mitochondrial complex I inhibitor rotenone induces apoptosis through enhancing mitochondrial reactive oxygen species production. Recently, it has been shown that fraxetin (coumarin) and myricetin (flavonoid) have significant neuroprotective effects against apoptosis induced by rotenone, increase the total glutathione levels in vitro, and inhibit lipid peroxidation. Thus, these considerations prompted us to investigate the way in which fraxetin and myricetin affect the endogenous antioxidant defense system, such as Mn and CuZn superoxide dismutase (MnSOD, CuZnSOD), catalase, glutathione reductase (GR), and glutathione peroxidase (GPx) on rotenone neurotoxicity in neuroblastoma cells. N-acetylcysteine (NAC), a potent antioxidant, was employed as a comparative agent. Also,more » the expression and protein levels of HSP70 by Northern and Western blot analysis were assayed in SH-SY5Y cells. After incubation for 16 h, rotenone significantly increased the expression and activity of MnSOD, GPx, and catalase. When cells were preincubated with fraxetin, there was a decrease in the protein levels and activity of both MnSOD and catalase, in comparison with the rotenone treatment. The myricetin effect was less pronounced. Activity and expression of GPx were increased by rotenone and pre-treatment with fraxetin did not modify significantly these levels. The significant enhancement in HSP70 expression at mRNA and protein levels induced by fraxetin was observed by pre-treatment of cells 0.5 h before rotenone insult. These data suggest that major features of rotenone-induced neurotoxicity are partially mediated by free radical formation and oxidative stress, and that fraxetin partially protects against rotenone toxicity affecting the main protection system of the cells against oxidative injury.« less

Cinnamic acid-inhibited ribulose-1,5-bisphosphate carboxylase activity is mediated through decreased spermine and changes in the ratio of polyamines in cowpea.

PubMed

Huang, Xingxue; Bie, Zhilong

2010-01-01

This study investigated the effects of cinnamic acid (CA) on ribulose-1,5-bisphosphate carboxylase (RuBPC) activity and the endogenous polyamine levels of cowpea leaves. The results show that 0.1 mM CA treatment decreased photosynthetic rate (P(n)) and RuBPC activity, but it did not affect the maximal photochemical efficiency of PSII (F(v)/F(m)), the actual photochemical efficiency of PSII (PhiPSII), intercellular CO(2) concentration (C(i)), and relative chlorophyll content. These suggest that the decrease in P(n) is at least partially attributed to a lowered RuBPC activity. In addition, 0.1 mM CA treatment increased the putrescine (Put) level, but decreased spermidine (Spd) and spermine (Spm) levels, thereby reducing the (Spd+Spm)/Put (PAs) ratio in the leaves. The exogenous application of 1 mM Spd markedly reversed these CA-induced effects for polyamine and partially restored the PAs ratio and RuBPC activity in leaves. Methylglyoxal-bis (guanylhydrazone) (MGBG), which is an inhibitor of S-adenosylmethionine decarboxylase (SAMDC), results in the inability of activated cells to synthesize Spd and exacerbates the negative effects induced by CA. The exogenous application of 1 mM D-arginine (D-Arg), which is an inhibitor of Put biosynthesis, decreased the levels of Put, but increased the PAs ratio and RuBPC activity in leaves. These results suggest that 0.1 mM CA inhibits RuBPC activity by decreasing the levels of endogenous free and perchloric acid soluble (PS) conjugated Spm, as well as the PAs ratio.

TNF-{alpha} promotes cell survival through stimulation of K{sup +} channel and NF{kappa}B activity in corneal epithelial cells

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

Wang Ling; Reinach, Peter; Lu, Luo

2005-11-15

Tumor necrosis factor (TNF-{alpha}) in various cell types induces either cell death or mitogenesis through different signaling pathways. In the present study, we determined in human corneal epithelial cells how TNF-{alpha} also promotes cell survival. Human corneal epithelial (HCE) cells were cultured in DMEM/F-12 medium containing 10% FBS. TNF-{alpha} stimulation induced activation of a voltage-gated K{sup +} channel detected by measuring single channel activity using patch clamp techniques. The effect of TNF-{alpha} on downstream events included NF{kappa}B nuclear translocation and increases in DNA binding activities, but did not elicit ERK, JNK, or p38 limb signaling activation. TNF-{alpha} induced increases inmore » p21 expression resulting in partial cell cycle attenuation in the G{sub 1} phase. Cell cycle progression was also mapped by flow cytometer analysis. Blockade of TNF-{alpha}-induced K{sup +} channel activity effectively prevented NF{kappa}B nuclear translocation and binding to DNA, diminishing the cell-survival protective effect of TNF-{alpha}. In conclusion, TNF-{alpha} promotes survival of HCE cells through sequential stimulation of K{sup +} channel and NF{kappa}B activities. This response to TNF-{alpha} is dependent on stimulating K{sup +} channel activity because following suppression of K{sup +} channel activity TNF-{alpha} failed to activate NF{kappa}B nuclear translocation and binding to nuclear DNA.« less

DNA–PKcs–SIN1 complexation mediates low-dose X-ray irradiation (LDI)-induced Akt activation and osteoblast differentiation

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

Xu, Yong; Fang, Shi-ji; Zhu, Li-juan

Highlights: • LDI increases ALP activity, promotes type I collagen (Col I)/Runx2 mRNA expression. • LDI induces DNA–PKcs activation, which is required for osteoblast differentiation. • Akt activation mediates LDI-induced ALP activity and Col I/Runx2 mRNA increase. • DNA–PKcs–SIN1 complexation mediates LDI-induced Akt Ser-473 phosphorylation. • DNA–PKcs–SIN1 complexation is important for osteoblast differentiation. - Abstract: Low-dose irradiation (LDI) induces osteoblast differentiation, however the underlying mechanisms are not fully understood. In this study, we explored the potential role of DNA-dependent protein kinase catalytic subunit (DNA–PKcs)–Akt signaling in LDI-induced osteoblast differentiation. We confirmed that LDI promoted mouse calvarial osteoblast differentiation, which wasmore » detected by increased alkaline phosphatase (ALP) activity as well as mRNA expression of type I collagen (Col I) and runt-related transcription factor 2 (Runx2). In mouse osteoblasts, LDI (1 Gy) induced phosphorylation of DNA–PKcs and Akt (mainly at Ser-473). The kinase inhibitors against DNA–PKcs (NU-7026 and NU-7441) or Akt (LY294002, perifosine and MK-2206), as well as partial depletion of DNA–PKcs or Akt1 by targeted-shRNA, dramatically inhibited LDI-induced Akt activation and mouse osteoblast differentiation. Further, siRNA-knockdown of SIN1, a key component of mTOR complex 2 (mTORC2), also inhibited LDI-induced Akt Ser-473 phosphorylation as well as ALP activity increase and Col I/Runx2 expression in mouse osteoblasts. Co-immunoprecipitation (Co-IP) assay results demonstrated that LDI-induced DNA–PKcs–SIN1 complexation, which was inhibited by NU-7441 or SIN1 siRNA-knockdown in mouse osteoblasts. In summary, our data suggest that DNA–PKcs–SIN1 complexation-mediated Akt activation (Ser-473 phosphorylation) is required for mouse osteoblast differentiation.« less

Differential Inflammatory-Response Kinetics of Human Keratinocytes upon Cytosolic RNA- and DNA-Fragment Induction.

PubMed

Danis, Judit; Janovák, Luca; Gubán, Barbara; Göblös, Anikó; Szabó, Kornélia; Kemény, Lajos; Bata-Csörgő, Zsuzsanna; Széll, Márta

2018-03-08

Keratinocytes are non-professional immune cells contributing actively to innate immune responses partially by reacting to a wide range of molecular patterns by activating pattern recognition receptors. Cytosolic nucleotide fragments as pathogen- or self-derived trigger factors are activating inflammasomes and inducing anti-viral signal transduction pathways as well as inducing expression of inflammatory cytokines. We aimed to compare the induced inflammatory reactions in three keratinocyte cell types-normal human epidermal keratinocytes, the HaCaT cell line and the HPV-KER cell line-upon exposure to the synthetic RNA and DNA analogues poly(I:C) and poly(dA:dT) to reveal the underlying signaling events. Both agents induced the expression of interleukin-6 and tumor necrosis factor α in all cell types; however, notable kinetic and expression level differences were found. Western blot analysis revealed rapid activation of the nuclear factor κB (NF-κB), mitogen activated protein kinase and signal transducers of activator of transcription (STAT) signal transduction pathways in keratinocytes upon poly(I:C) treatment, while poly(dA:dT) induced slower activation. Inhibition of NF-κB, p38, STAT-1 and STAT-3 signaling resulted in decreased cytokine expression, whereas inhibition of mitogen-activated protein kinase kinase 1/2 (MEK1/2) signaling showed a negative feedback role in both poly(I:C)- and poly(dA:dT)-induced cytokine expression. Based on our in vitro results nucleotide fragments are able to induce inflammatory reactions in keratinocytes, but with different rate and kinetics of cytokine expression, explained by faster activation of signaling routes by poly(I:C) than poly(dA:dT).

Differential Inflammatory-Response Kinetics of Human Keratinocytes upon Cytosolic RNA- and DNA-Fragment Induction

PubMed Central

Danis, Judit; Janovák, Luca; Gubán, Barbara; Göblös, Anikó; Szabó, Kornélia; Bata-Csörgő, Zsuzsanna; Széll, Márta

2018-01-01

Keratinocytes are non-professional immune cells contributing actively to innate immune responses partially by reacting to a wide range of molecular patterns by activating pattern recognition receptors. Cytosolic nucleotide fragments as pathogen- or self-derived trigger factors are activating inflammasomes and inducing anti-viral signal transduction pathways as well as inducing expression of inflammatory cytokines. We aimed to compare the induced inflammatory reactions in three keratinocyte cell types—normal human epidermal keratinocytes, the HaCaT cell line and the HPV-KER cell line—upon exposure to the synthetic RNA and DNA analogues poly(I:C) and poly(dA:dT) to reveal the underlying signaling events. Both agents induced the expression of interleukin-6 and tumor necrosis factor α in all cell types; however, notable kinetic and expression level differences were found. Western blot analysis revealed rapid activation of the nuclear factor κB (NF-κB), mitogen activated protein kinase and signal transducers of activator of transcription (STAT) signal transduction pathways in keratinocytes upon poly(I:C) treatment, while poly(dA:dT) induced slower activation. Inhibition of NF-κB, p38, STAT-1 and STAT-3 signaling resulted in decreased cytokine expression, whereas inhibition of mitogen-activated protein kinase kinase 1/2 (MEK1/2) signaling showed a negative feedback role in both poly(I:C)- and poly(dA:dT)-induced cytokine expression. Based on our in vitro results nucleotide fragments are able to induce inflammatory reactions in keratinocytes, but with different rate and kinetics of cytokine expression, explained by faster activation of signaling routes by poly(I:C) than poly(dA:dT). PMID:29518010

Attenuation of TNF-induced neutrophil adhesion by simvastatin is associated with the inhibition of Rho-GTPase activity, p50 activity and morphological changes.

PubMed

Antoniellis Silveira, Angélica Aparecida; Dominical, Venina Marcela; Morelli Vital, Daiana; Alves Ferreira, Wilson; Trindade Maranhão Costa, Fabio; Werneck, Claudio C; Ferreira Costa, Fernando; Conran, Nicola

2018-05-01

Neutrophil adhesion to the vasculature in response to potent inflammatory stimuli, such as TNF-α (TNF), can contribute to atheroprogression amongst other pathophysiological mechanisms. Previous studies have shown that simvastatin, a statin with known pleiotropic anti-inflammatory properties, can partially abrogate the effects of TNF-induced neutrophil adhesion, in association with the modulation of β 2 -integrin expression. We aimed to further characterize the effects of this statin on neutrophil and leukocyte adhesive mechanisms in vitro and in vivo. A microfluidic assay confirmed the ability of simvastatin to inhibit TNF-induced human neutrophil adhesion to fibronectin ligand under conditions of shear stress, while intravital imaging microscopy demonstrated an abrogation of leukocyte recruitment by simvastatin in the microvasculature of mice that had received a TNF stimulus. This inhibition of neutrophil adhesion was accompanied by the inhibition of TNF-induced RhoA activity in human neutrophils, and alterations in cell morphology and β 2 -integrin activity. Additionally, TNF augmented the activity of the p50 NFκB subunit in human neutrophils and TNF-induced neutrophil adhesion and β 2 -integrin activity could be abolished using pharmacological inhibitors of NFκB translocation, BAY11-7082 and SC514. Accordingly, the TNF-induced elevation of neutrophil p50 activity was abolished by simvastatin. In conclusion, our data provide further evidence of the ability of simvastatin to inhibit neutrophil adhesive interactions in response to inflammatory stimuli, both in vivo and in vitro. Simvastatin appears to inhibit neutrophil adhesion by interfering in TNF-induced cytoskeletal rearrangements, in association with the inhibition of Rho A activity, NFκB translocation and, consequently, β 2 -integrin activity. Copyright © 2018 Elsevier B.V. All rights reserved.

Annonaceous acetogenin mimic AA005 induces cancer cell death via apoptosis inducing factor through a caspase-3-independent mechanism.

PubMed

Han, Bing; Wang, Tong-Dan; Shen, Shao-Ming; Yu, Yun; Mao, Chan; Yao, Zhu-Jun; Wang, Li-Shun

2015-03-18

Annonaceous acetogenins are a family of natural products with antitumor activities. Annonaceous acetogenin mimic AA005 reportedly inhibits mammalian mitochondrial NADH-ubiquinone reductase (Complex I) and induces gastric cancer cell death. However, the mechanisms underlying its cell-death-inducing activity are unclear. We used SW620 colorectal adenocarcinoma cells to study AA005 cytotoxic activity. Cell deaths were determined by Trypan blue assay and flow cytometry, and related proteins were characterized by western blot. Immunofluorescence and subcellular fractionation were used to evaluate AIF nuclear translocation. Reactive oxygen species were assessed by using redox-sensitive dye DCFDA. AA005 induces a unique type of cell death in colorectal adenocarcinoma cells, characterized by lack of caspase-3 activation or apoptotic body formation, sensitivity to poly (ADP-ribose) polymerase inhibitor Olaparib (AZD2281) but not pan-caspase inhibitor Z-VAD.fmk, and dependence on apoptosis-inducing factor (AIF). AA005 treatment also reduced expression of mitochondrial Complex I components, and leads to accumulation of intracellular reactive oxygen species (ROS) at the early stage. Blocking ROS formation significantly suppresses AA005-induced cell death in SW620 cells. Moreover, blocking activation of RIP-1 by necroptosis inhibitor necrotatin-1 inhibits AIF translocation and partially suppresses AA005-induced cell death in SW620 cells demonstrating that RIP-1 protein may be essential for cell death. AA005 may trigger the cell death via mediated by AIF through caspase-3 independent pathway. Our work provided new mechanisms for AA005-induced cancer cell death and novel clues for cancer treatment via AIF dependent cell death.

P62 plasmid can alleviate diet-induced obesity and metabolic dysfunctions.

PubMed

Halenova, Tatiana; Savchuk, Oleksii; Ostapchenko, Ludmila; Chursov, Andrey; Fridlyand, Nathan; Komissarov, Andrey B; Venanzi, Franco; Kolesnikov, Sergey I; Sufianov, Albert A; Sherman, Michael Y; Gabai, Vladimir L; Shneider, Alexander M

2017-08-22

A high-calorie diet (HCD) induces two mutually exacerbating effects contributing to diet-induced obesity (DIO): impaired glucose metabolism and increased food consumption. A link between the metabolic and behavioral manifestations is not well understood yet. We hypothesized that chronic inflammation induced by HCD plays a key role in linking together the two components of diet-induced pathology. Based on this hypothesis, we tested if a plasmid (DNA vaccine) encoding p62 (SQSTM1) would alleviate DIO including its metabolic and/or food consumption abnormalities. Previously we reported that injections of the p62 plasmid reduce chronic inflammation during ovariectomy-induced osteoporosis. Here we found that the p62 plasmid reduced levels of pro-inflammatory cytokines IL-1β, IL-12, and INFγ and increased levels of anti-inflammatory cytokines IL-4, IL-10 and TGFβ in HCD-fed animals. Due to this anti-inflammatory response, we further tested whether the plasmid can alleviate HCD-induced obesity and associated metabolic and feeding impairments. Indeed, p62 plasmid significantly reversed effects of HCD on the body mass index (BMI), levels of glucose, insulin and glycosylated hemoglobin (HbA1c). Furthermore, p62 plasmid partially restored levels of the satiety hormone, serotonin, and tryptophan, simultaneously reducing activity of monoamine oxidase (MAO) in the brain affected by the HCD. Finally, the plasmid partially reversed increased food consumption caused by HCD. Therefore, the administering of p62 plasmid alleviates both metabolic and behavioral components of HCD-induced obesity.

Biphasic and synergistic activation of p44mapk (ERK1) by growth factors: correlation between late phase activation and mitogenicity.

PubMed

Meloche, S; Seuwen, K; Pagès, G; Pouysségur, J

1992-05-01

We have examined the phosphorylation and protein kinase activity of p44 mitogen-activated protein kinase (p44mapk) in growth factor-stimulated hamster fibroblasts using a specific antiserum. The activity of p44mapk was stimulated both by receptor tyrosine kinases and G protein-coupled receptors. Detailed kinetics revealed that alpha-thrombin induces a biphasic activation of p44mapk in CCL39 cells: a rapid phase appearing at 5-10 min was followed by a late and sustained phase still elevated after 4 h. Inactivation of alpha-thrombin with hirudin after 30 sec, which prevented DNA synthesis, did not alter the early p44mapk response but completely abolished the late phase. Pretreatment of the cells with pertussis toxin, which inhibits by more than 95% alpha-thrombin-induced mitogenicity, resulted in the complete loss of late phase activity, while the early peak was partially attenuated. Treatment of CCL39 cells with basic fibroblast growth factor also induced a strong activation of p44mapk. Serotonin, which is not a mitogen by its own, had no effect on late phase p44mapk activity, but synergized with basic fibroblast growth factor to induce late kinase response and DNA synthesis. Both early and late phase activation of p44mapk were accompanied by tyrosine phosphorylation of the enzyme. Together, the results indicate that there is a very close correlation between the ability of a growth factor to induce late and sustained p44mapk activation and its mitogenic potential. Therefore, we propose that sustained p44mapk activation is an obligatory event for growth factor-induced cell cycle progression.

Probing Conformational Rescue Induced by a Chemical Corrector of F508del-Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Mutant*

PubMed Central

Yu, Wilson; Chiaw, Patrick Kim; Bear, Christine E.

2011-01-01

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that cause loss of function of the CFTR channel on the apical surface of epithelial cells. The major CF-causing mutation, F508del-CFTR, is misfolded, retained in the endoplasmic reticulum, and degraded. Small molecule corrector compounds have been identified using high throughput screens, which partially rescue the trafficking defect of F508del-CFTR, allowing a fraction of the mutant protein to escape endoplasmic reticulum retention and traffic to the plasma membrane, where it exhibits partial function as a cAMP-regulated chloride channel. A subset of such corrector compounds binds directly to the mutant protein, prompting the hypothesis that they rescue the biosynthetic defect by inducing improved protein conformation. We tested this hypothesis directly by evaluating the consequences of a corrector compound on the conformation of each nucleotide binding domain (NBD) in the context of the full-length mutant protein in limited proteolytic digest studies. Interestingly, we found that VRT-325 was capable of partially restoring compactness in NBD1. However, VRT-325 had no detectable effect on the conformation of the second half of the molecule. In comparison, ablation of the di-arginine sequence, R553XR555 (F508del-KXK-CFTR), modified protease susceptibility of NBD1, NBD2, and the full-length protein. Singly, each intervention led to a partial correction of the processing defect. Together, these interventions restored processing of F508del-CFTR to near wild type. Importantly, however, a defect in NBD1 conformation persisted, as did a defect in channel activation after the combined interventions. Importantly, this defect in channel activation can be fully corrected by the addition of the potentiator, VX-770. PMID:21602569

PRRX2 as a novel TGF-β-induced factor enhances invasion and migration in mammary epithelial cell and correlates with poor prognosis in breast cancer.

PubMed

Juang, Yu-Lin; Jeng, Yung-Ming; Chen, Chi-Long; Lien, Huang-Chun

2016-12-01

TGF-β and cancer progression share a multifaceted relationship. Despite the knowledge of TGF-β biology in the development of cancer, several factors that mediate the cancer-promoting role of TGF-β continue to be identified. This study aimed to identify and characterise novel factors potentially related to TGF-β-mediated tumour aggression in breast cells. We treated the human mammary epithelial cell line MCF10A with TGF-β and identified TGF-β-dependent upregulation of PRRX2, the gene encoding paired-related homeobox 2 transcription factor. Overexpression of PRRX2 enhanced migration, invasion and anchorage-independent growth of MCF10A cells and induced partial epithelial mesenchymal transition (EMT), as determined by partial fibroblastoid morphology of cells, upregulation of EMT markers and partially disrupted acinar structure in a three-dimensional culture. We further identified PLAT, the gene encoding tissue-type plasminogen activator (tPA), as the highest differentially expressed gene in PRRX2-overexpressing MCF10A cells, and demonstrated direct binding and transactivation of the PLAT promoter by PRRX2. Furthermore, PLAT knockdown inhibited PRRX2-mediated enhanced migration and invasion, suggesting that tPA may mediate PRRX2-induced migration and invasion. Finally, the significant correlation of PRRX2 expression with poor survival in 118 primary breast tumour samples (P = 0.027) and the increased PRRX2 expression in metaplastic breast carcinoma samples, which is pathogenetically related to EMT, validated the biological importance of PRRX2-enhanced migration and invasion and PRRX2-induced EMT. Thus, our data suggest that upregulation of PRRX2 may be a mechanism contributing to TGF-β-induced invasion and EMT in breast cancer. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Metabolic effects of physiological levels of caffeine in myotubes.

PubMed

Schnuck, Jamie K; Gould, Lacey M; Parry, Hailey A; Johnson, Michele A; Gannon, Nicholas P; Sunderland, Kyle L; Vaughan, Roger A

2018-02-01

Caffeine has been shown to stimulate multiple major regulators of cell energetics including AMP-activated protein kinase (AMPK) and Ca 2+ /calmodulin-dependent protein kinase II (CaMKII). Additionally, caffeine induces peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and mitochondrial biogenesis. While caffeine enhances oxidative metabolism, experimental concentrations often exceed physiologically attainable concentrations through diet. This work measured the effects of low-level caffeine on cellular metabolism and gene expression in myotubes, as well as the dependence of caffeine's effects on the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPARβ/δ). C2C12 myotubes were treated with various doses of caffeine for up to 24 h. Gene and protein expression were measured via qRT-PCR and Western blot, respectively. Cellular metabolism was determined via oxygen consumption and extracellular acidification rate. Caffeine significantly induced regulators of mitochondrial biogenesis and oxidative metabolism. Mitochondrial staining was suppressed in PPARβ/δ-inhibited cells which was rescued by concurrent caffeine treatment. Caffeine-treated cells also displayed elevated peak oxidative metabolism which was partially abolished following PPARβ/δ inhibition. Similar to past observations, glucose uptake and GLUT4 content were elevated in caffeine-treated cells, however, glycolytic metabolism was unaltered following caffeine treatment. Physiological levels of caffeine appear to enhance cell metabolism through mechanisms partially dependent on PPARβ/δ.

Acetylation of pregnane X receptor protein determines selective function independent of ligand activation

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

Biswas, Arunima; Pasquel, Danielle; Tyagi, Rakesh Kumar

2011-03-18

Research highlights: {yields} Pregnane X receptor (PXR), a major regulatory protein, is modified by acetylation. {yields} PXR undergoes dynamic deacetylation upon ligand-mediated activation. {yields} SIRT1 partially mediates PXR deacetylation. {yields} PXR deacetylation per se induces lipogenesis mimicking ligand-mediated activation. -- Abstract: Pregnane X receptor (PXR), like other members of its class of nuclear receptors, undergoes post-translational modification [PTM] (e.g., phosphorylation). However, it is unknown if acetylation (a major and common form of protein PTM) is observed on PXR and, if it is, whether it is of functional consequence. PXR has recently emerged as an important regulatory protein with multiple ligand-dependentmore » functions. In the present work we show that PXR is indeed acetylated in vivo. SIRT1 (Sirtuin 1), a NAD-dependent class III histone deacetylase and a member of the sirtuin family of proteins, partially mediates deacetylation of PXR. Most importantly, the acetylation status of PXR regulates its selective function independent of ligand activation.« less

Salicylic Acid and Ethylene Pathways Are Differentially Activated in Melon Cotyledons by Active or Heat-Denatured Cellulase from Trichoderma longibrachiatum

PubMed Central

Martinez, Christelle; Blanc, Frédéric; Le Claire, Emilie; Besnard, Olivier; Nicole, Michel; Baccou, Jean-Claude

2001-01-01

Infiltration of cellulase (EC 3.2.1.4) from Trichoderma longibrachiatum into melon (Cucumis melo) cotyledons induced several key defense mechanisms and hypersensitive reaction-like symptoms. An oxidative burst was observed 3 hours after treatment and was followed by activation of ethylene and salicylic acid (SA) signaling pathways leading to marked induction of peroxidase and chitinase activities. The treatment of cotyledons by heat-denatured cellulase also led to some induction of peroxidase and chitinase activities, but the oxidative burst and SA production were not observed. Co-infiltration of aminoethoxyvinil-glycine (an ethylene inhibitor) with the active cellulase did not affect the high increase of peroxidase and chitinase activities. In contrast, co-infiltration of aminoethoxyvinil-glycine with the denatured enzyme blocked peroxidase and chitinase activities. Our data suggest that the SA pathway (induced by the cellulase activity) and ethylene pathway (induced by heat-denatured and active protein) together coordinate the activation of defense mechanisms. We found a partial interaction between both signaling pathways since SA caused an inhibition of the ethylene production and a decrease in peroxidase activity when co-infiltrated with denatured cellulase. Treatments with active or denatured cellulase caused a reduction in powdery mildew (Sphaerotheca fuliginea) disease. PMID:11553761

Neutralization, by a monospecific Bothrops lanceolatus antivenom, of toxic activities induced by homologous and heterologous Bothírops snake venoms.

PubMed

Bogarín, G; Romero, M; Rojas, G; Lutsch, C; Casadamont, M; Lang, J; Otero, R; Gutiérrez, J M

1999-03-01

A monospecific Bothrops lanceolatus antivenom, currently used in Martinique, was tested for its efficacy in the neutralization of several toxic and enzymatic activities of the venoms of B. lanceolatus, B. atrox and B. asper. When tested by the i.p. route in mice, B. lanceolatus venom had an LD50 of 12.8 microg/g. In addition, it induced local tissue damage (hemorrhage, edema and myotoxicity) and showed indirect hemolytic activity, but was devoid of coagulant effect on human plasma in vitro and of defibrinating activity in mice. Antivenom was fully effective in the neutralization of lethal, hemorrhagic, edema-forming, myotoxic and indirect hemolytic effects of B. lanceolatus venom in assays involving preincubation of venom and antivenom. When tested against the venoms of B. asper and B. atrox, the antivenom completely neutralized the lethal, hemorrhagic, myotoxic and indirect hemolytic effects, and was partially effective in neutralizing edema-forming activity. In contrast, the antivenom was ineffective in the neutralization of in vitro coagulant and in vivo defibrinating effects induced by these two venoms.

Bropirimine inhibits osteoclast differentiation through production of interferon-β

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

Suzuki, Hiroaki; Mochizuki, Ayako; Yoshimura, Kentaro

Bropirimine is a synthetic agonist for toll-like receptor 7 (TLR7). In this study, we investigated the effects of bropirimine on differentiation and bone-resorbing activity of osteoclasts in vitro. Bropirimine inhibited osteoclast differentiation of mouse bone marrow-derived macrophages (BMMs) induced by receptor activator of nuclear factor κB ligand (RANKL) in a concentration-dependent manner. Furthermore, it suppressed the mRNA expression of nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1), a master transcription factor for osteoclast differentiation, without affecting BMM viability. Bropirimine also inhibited osteoclast differentiation induced in co-cultures of mouse bone marrow cells (BMCs) and mouse osteoblastic UAMS-32 cells in the presencemore » of activated vitamin D{sub 3}. Bropirimine partially suppressed the expression of RANKL mRNA in UAMS-32 cells induced by activated vitamin D{sub 3}. Finally, the anti-interferon-β (IFN-β) antibody restored RANKL-dependent differentiation of BMMs into osteoclasts suppressed by bropirimine. These results suggest that bropirimine inhibits differentiation of osteoclast precursor cells into osteoclasts via TLR7-mediated production of IFN-β.« less

Lycium barbarum polysaccharide protects against LPS-induced ARDS by inhibiting apoptosis, oxidative stress, and inflammation in pulmonary endothelial cells.

PubMed

Chen, Lan; Li, Wen; Qi, Di; Wang, Daoxin

2018-04-01

Acute respiratory distress syndrome (ARDS) is a heterogenous syndrome characterised by diffuse alveolar damage, with an increase in lung endothelial and epithelial permeability. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses antiapoptotic and antioxidative effects in distinct situations. In the present study, the protective effects and potential molecular mechanisms of LBP against lipopolysaccharide (LPS)-induced ARDS were investigated in the mice and in the human pulmonary microvascular endothelial cells (HPMECs). The data indicated that pretreatment with LBP significantly attenuated LPS-induced lung inflammation and pulmonary oedema in vivo. LBP significantly reversed LPS-induced decrease in cell viability, increase in apoptosis and oxidative stress via inhibiting caspase-3 activation and intracellular reactive oxygen species (ROS) production in vitro. Moreover, the scratch assay verified that LBP restored the dysfunction of endothelial cells (ECs) migration induced by LPS stimulation. Furthermore, LBP also significantly suppressed LPS-induced NF-κB activation, and subsequently reversed the release of cytochrome c. These results showed the antiapoptosis and antioxidant LBP could partially protect against LPS-induced ARDS through promoting the ECs survival and scavenging ROS via inhibition of NF-κB signalling pathway. Thus, LBP could be potentially used for ARDS against pulmonary inflammation and pulmonary oedema.

Curcumin eliminates the inhibitory effect of advanced glycation end-products (AGEs) on gene expression of AGE receptor-1 in hepatic stellate cells in vitro

PubMed Central

Lin, Jianguo; Tang, Youcai; Kang, Qiaohua; Chen, Anping

2012-01-01

Diabetes is featured by hyperglycemia, which facilitates the formation of advanced glycation end-products (AGEs). AGEs are a causal factor in development of diabetic complications. AGE receptor-1 (AGE-R1) is responsible for detoxification and clearance of AGEs. Type 2 diabetes mellitus is commonly accompanied by non-alcoholic steatohepatitis, which could cause hepatic fibrosis. Little attention has been paid to effects of AGEs on hepatic fibrogenesis. Curcumin, a phytochemical from turmeric, has been reported to inhibit the activation of hepatic stellate cells (HSCs), the major effectors during hepatic fibrogenesis, and to protect against hepatic fibrogenesis in vitro and in vivo. The current study was designed to evaluate effects of AGEs on inducing HSC activation, to assess the role of curcumin in diminishing the AGE effects and to explore the underlying mechanisms. Our results showed that AGEs stimulated HSC activation by inducing cell proliferation and expression of genes relevant to HSC activation, which were abrogated by curcumin. Curcumin induced gene expression of AGE-R1 in passaged HSCs, which might facilitate the attenuation of the stimulatory effects of AGEs on the activation of HSCs. Further experiments revealed that curcumin inhibited the activity of extracellular signal-regulated kinase (ERK) and induced gene expression and the activity of peroxisome proliferator-activated receptor-gamma (PPARγ), leading to the induction of AGE-R1 gene expression. In summary, AGEs stimulated HSC activation. Curcumin eliminated the AGE effects at least partially by inducing AGE-R1 gene expression. The process was mediated by inhibiting ERK activity, inducing gene expression of PPARγ and stimulating its trans-activity. PMID:22449800

Aleglitazar, a dual peroxisome proliferator-activated receptor-α and -γ agonist, protects cardiomyocytes against the adverse effects of hyperglycaemia.

PubMed

Chen, Yan; Chen, Hongmei; Birnbaum, Yochai; Nanhwan, Manjyot K; Bajaj, Mandeep; Ye, Yumei; Qian, Jinqiao

2017-03-01

To assess the effects of Aleglitazar on hyperglycaemia-induced apoptosis. We incubated human cardiomyocytes, cardiomyocytes from cardiac-specific peroxisome proliferator-activated receptor-γ knockout or wild-type mice in normoglycaemic or hyperglycaemic conditions (glucose 25 mM). Cells were treated with different concentrations of Aleglitazar for 48 h. We measured viability, apoptosis, caspase-3 activity, cytochrome-C release, total antioxidant capacity and reactive oxygen species formation in the treated cardiomyocytes. Human cardiomyocytes were transfected with short interfering RNA against peroxisome proliferator-activated receptor-α or peroxisome proliferator-activated receptor-γ. Aleglitazar attenuated hyperglycaemia-induced apoptosis, caspase-3 activity and cytochrome-C release and increased viability in human cardiomyocyte, cardiomyocytes from cardiac-specific peroxisome proliferator-activated receptor-γ knockout and wild-type mice. Hyperglycaemia reduced the antioxidant capacity and Aleglitazar significantly blunted this effect. Hyperglycaemia-induced reactive oxygen species production was attenuated by Aleglitazar in both human cardiomyocyte and wild-type mice cardiomyocytes. Aleglitazar improved cell viability in cells exposed to hyperglycaemia. The protective effect was partially blocked by short interfering RNA against peroxisome proliferator-activated receptor-α alone and short interfering RNA against peroxisome proliferator-activated receptor-γ alone and completely blocked by short interfering RNA to both peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-γ. Aleglitazar protects cardiomyocytes against hyperglycaemia-induced apoptosis by combined activation of both peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-γ in a short-term vitro model.

Translocation of arrestin induced by human A(3) adenosine receptor ligands in an engineered cell line: comparison with G protein-dependent pathways.

PubMed

Gao, Zhan-Guo; Jacobson, Kenneth A

2008-04-01

Structurally diverse ligands were studied in A(3) adenosine receptor (AR)-mediated beta-arrestin translocation in engineered CHO cells. The agonist potency and efficacy were similar, although not identical, to their G protein signaling. However, differences have also been found. MRS542, MRS1760, and other adenosine derivatives, A(3)AR antagonists in cyclic AMP assays, were partial agonists in beta-arrestin translocation, indicating possible biased agonism. The xanthine 7-riboside DBXRM, a full agonist, was only partially efficacious in beta-arrestin translocation. DBXRM was shown to induce a lesser extent of desensitization compared with IB-MECA. In kinetic studies, MRS3558, a potent and selective A(3)AR agonist, induced beta-arrestin translocation significantly faster than IB-MECA and Cl-IB-MECA. Non-nucleoside antagonists showed similar inhibitory potencies as previously reported. PTX pretreatment completely abolished ERK1/2 activation, but not arrestin translocation. Thus, lead candidates for biased agonists at the A(3)AR have been identified with this arrestin-translocation assay, which promises to be an effective tool for ligand screening.

Tamoxifen enhances therapeutic effects of gemcitabine on cholangiocarcinoma tumorigenesis.

PubMed

Jing, Gu; Yuan, Kaiyu; Turk, Amy N; Jhala, Nirag C; Arnoletti, Juan P; Zhang, Kui; McDonald, Jay M; Chen, Yabing

2011-06-01

Cholangiocarcinoma is a highly malignant tumor with limited therapeutic options. We have previously reported that tamoxifen (TMX) induces apoptosis of cholangiocarcinoma cells and reduces cholangiocarcinoma tumorigenesis in mice. In the present studies, we determined the effect of combination therapy of TMX and gemcitabine (GMT), another chemotherapeutical reagent for many cancers, on cholangiocarcinoma tumorigenesis and investigated the responsible mechanisms. GMT inhibited cell growth and induced apoptosis of cholangiocarcinoma cells in a concentration-dependent manner. TMX enhanced GMT-induced apoptosis of cholangiocarcinoma cells. Consistently, GMT (15 mg/kg) inhibited cholangiocarcinoma tumorigenesis in nude mice by 50%. TMX (15 mg/kg) enhanced the inhibitory effect of GMT on tumorigenesis by 33%. The inhibition of tumor growth correlated with enhanced apoptosis in tumor tissues. To elucidate the mechanisms underlying the additive effects of TMX on GMT-induced apoptosis, we determined the activation of caspases in cholangiocarcinoma cells exposed to GMT, TMX, or both. Activation of caspases 9 and 3, as well as cytochrome c release to the cytosol, was demonstrated in cells exposed to both reagents. In contrast, TMX activated caspase 2, whereas GMT had no effect. Inhibition of caspase 2 activation decreased TMX-, but not GMT-, induced activation of caspase 3 and apoptosis of cholangiocarcinoma cells. Similarly, activation of caspase 2 was found in tumors from TMX-treated mice, but not GMT-treated mice. Therefore, the enhanced effect of TMX on GMT-induced cholangiocarcinoma cell death is partially mediated by activation of caspase 2. TMX and GMT both induce apoptosis and inhibit cholangiocarcinoma tumorigenesis, which may be attributed to the activation of distinct apoptosis signals by TMX and GMT. Our studies provide in vivo evidence and molecular insight to support the use of TMX and GMT in combination as an effective therapy for cholangiocarcinoma.

Treadmill Intervention Attenuates the Cafeteria Diet-Induced Impairment of Stress-Coping Strategies in Young Adult Female Rats

PubMed Central

Cigarroa, Igor; Lalanza, Jaume F.; Caimari, Antoni; del Bas, Josep M.; Capdevila, Lluís; Arola, Lluís; Escorihuela, Rosa M.

2016-01-01

The current prevalence of diet-induced overweight and obesity in adolescents and adults is continuously growing. Although the detrimental biochemical and metabolic consequences of obesity are widely studied, its impact on stress-coping behavior and its interaction with specific exercise doses (in terms of intensity, duration and frequency) need further investigation. To this aim, we fed adolescent rats either an obesogenic diet (cafeteria diet, CAF) or standard chow (ST). Each group was subdivided into four subgroups according to the type of treadmill intervention as follows: a sedentary group receiving no manipulation; a control group exposed to a stationary treadmill; a low-intensity treadmill group trained at 12 m/min; and a higher intensity treadmill group trained at 17 m/min. Both the diet and treadmill interventions started at weaning and lasted for 8 weeks. Subjects were tested for anxiety-like behavior in the open field test and for coping strategies in the two-way active avoidance paradigm at week 7 and were sacrificed at week 8 for biometric and metabolic characterization. CAF feeding increased the weight gain, relative retroperitoneal white adipose tissue (RWAT %), and plasma levels of glucose, insulin, triglycerides and leptin and decreased the insulin sensitivity. Treadmill intervention partially reversed the RWAT% and triglyceride alterations; at higher intensity, it decreased the leptin levels of CAF-fed animals. CAF feeding decreased the motor activity and impaired the performance in a two-way active avoidance assessment. Treadmill intervention reduced defecation in the shuttle box, suggesting diminished anxiety. CAF feeding combined with treadmill training at 17 m/min increased the time spent in the center of the open field and more importantly, partially reversed the two-way active avoidance deficit. In conclusion, this study demonstrates that at doses that decreased anxiety-like behavior, treadmill exercise partially improved the coping strategy in terms of active avoidance behavior in the CAF-fed animals. This effect was not observed at lower doses of treadmill training. PMID:27099927

Treadmill Intervention Attenuates the Cafeteria Diet-Induced Impairment of Stress-Coping Strategies in Young Adult Female Rats.

PubMed

Cigarroa, Igor; Lalanza, Jaume F; Caimari, Antoni; del Bas, Josep M; Capdevila, Lluís; Arola, Lluís; Escorihuela, Rosa M

2016-01-01

The current prevalence of diet-induced overweight and obesity in adolescents and adults is continuously growing. Although the detrimental biochemical and metabolic consequences of obesity are widely studied, its impact on stress-coping behavior and its interaction with specific exercise doses (in terms of intensity, duration and frequency) need further investigation. To this aim, we fed adolescent rats either an obesogenic diet (cafeteria diet, CAF) or standard chow (ST). Each group was subdivided into four subgroups according to the type of treadmill intervention as follows: a sedentary group receiving no manipulation; a control group exposed to a stationary treadmill; a low-intensity treadmill group trained at 12 m/min; and a higher intensity treadmill group trained at 17 m/min. Both the diet and treadmill interventions started at weaning and lasted for 8 weeks. Subjects were tested for anxiety-like behavior in the open field test and for coping strategies in the two-way active avoidance paradigm at week 7 and were sacrificed at week 8 for biometric and metabolic characterization. CAF feeding increased the weight gain, relative retroperitoneal white adipose tissue (RWAT %), and plasma levels of glucose, insulin, triglycerides and leptin and decreased the insulin sensitivity. Treadmill intervention partially reversed the RWAT% and triglyceride alterations; at higher intensity, it decreased the leptin levels of CAF-fed animals. CAF feeding decreased the motor activity and impaired the performance in a two-way active avoidance assessment. Treadmill intervention reduced defecation in the shuttle box, suggesting diminished anxiety. CAF feeding combined with treadmill training at 17 m/min increased the time spent in the center of the open field and more importantly, partially reversed the two-way active avoidance deficit. In conclusion, this study demonstrates that at doses that decreased anxiety-like behavior, treadmill exercise partially improved the coping strategy in terms of active avoidance behavior in the CAF-fed animals. This effect was not observed at lower doses of treadmill training.

Fluocinolone acetonide partially restores the mineralization of LPS-stimulated dental pulp cells through inhibition of NF-κB pathway and activation of AP-1 pathway

PubMed Central

Liu, Zhongning; Jiang, Ting; Wang, Xinzhi; Wang, Yixiang

2013-01-01

BACKGROUND AND PURPOSE Fluocinolone acetonide (FA) is commonly used as a steroidal anti-inflammatory drug. We recently found that in dental pulp cells (DPCs) FA has osteo-/odonto-inductive as well as anti-inflammatory effects. However, the mechanism by which FA induces these effects in DPCs is poorly understood. EXPERIMENTAL APPROACH The effect of FA on the mineralization of DPCs during inflammatory conditions and the underlying mechanism were investigated by real-time PCR, Western blot, EMSA, histochemical staining, immunostaining and pathway blockade assays. KEY RESULTS FA significantly inhibited the inflammatory response in LPS-treated DPCs not only by down-regulating the expression of pro–inflammation-related genes, but also by up-regulating the expression of the anti-inflammatory gene PPAR-γ and mineralization-related genes. Moreover, histochemical staining and immunostaining showed that FA could partially restore the expressions of alkaline phosphatase, osteocalcin and dentin sialophosphoprotein (DSPP) and mineralization in LPS-stimulated DPCs. Real-time PCR and Western blot analysis revealed that FA up-regulated DSPP and runt-related transcription factor 2 expression by inhibiting the expression of phosphorylated-NF-κB P65 and activating activator protein-1 (AP-1) (p-c-Jun and Fra-1). These results were further confirmed through EMSA, by detection of NF-κB DNA-binding activity and pathway blockade assays using a NF-κB pathway inhibitor, AP-1 pathway inhibitor and glucocorticoid receptor antagonist. CONCLUSIONS AND IMPLICATIONS Inflammation induced by LPS suppresses the mineralization process in DPCs. FA partially restored this osteo-/odonto-genesis process in LPS-treated DPCs and had an anti-inflammatory effect through inhibition of the NF-κB pathway and activation of the AP-1 pathway. Hence, FA is a potential new treatment for inflammation-associated bone/teeth diseases. PMID:24024985

Electrophysiological evidence showing muscarinic agonist-antagonist activities of N-desmethylclozapine using hippocampal excitatory and inhibitory neurons.

PubMed

Sugawara, Yuto; Kikuchi, Yui; Yoneda, Mitsugu; Ohno-Shosaku, Takako

2016-07-01

The atypical antipsychotic clozapine is widely used for treatment-resistant schizophrenic patients. Clozapine and its major active metabolite, N-desmethylclozapine (NDMC), have complex pharmacological properties, and interact with various neurotransmitter receptors. There are several biochemical studies reporting that NDMC exhibits a partial agonist profile at the human recombinant M1 muscarinic receptors. However, direct electrophysiological evidence showing the ability of NDMC to activate native M1 receptors in intact neurons is poor. Using rat hippocampal neurons, we previously demonstrated that activation of muscarinic receptors by a muscarinic agonist, oxotremorine M (oxo-M), induces a decrease in outward K(+)current at -40mV. In the present study, using this muscarinic current response we assessed agonist and antagonist activities of clozapine and NDMC at native muscarinic receptors in intact hippocampal excitatory and inhibitory neurons. Suppression of the oxo-M-induced current response by the M1 antagonist pirenzepine was evident only in excitatory neurons, while the M3 antagonist darifenacin was effective in both types of neurons. Muscarinic agonist activity of NDMC was higher than that of clozapine, higher in excitatory neurons than in inhibitory neurons, sensitive to pirenzepine, and partially masked when co-applied with clozapine. Muscarinic antagonist activity of clozapine as well as NDMC was not different between excitatory and inhibitory neurons, but clozapine was more effective than NDMC. These results demonstrate that NDMC has the ability to activate native M1 receptors expressed in hippocampal excitatory neurons, but its agonist activity might be limited in clozapine-treated patients because of the presence of excessive clozapine with muscarinic antagonist activity. Copyright © 2016 Elsevier B.V. All rights reserved.

Experimental Edema Disease of Swine (E. Coli ENTEROTOXEMIA) I. Detection and Preparation of an Active Principle

PubMed Central

Clugston, R. E.; Nielsen, N. O.

1974-01-01

Freeze-thaw lysates prepared from strains of Escherichia coli belonging to serogroups O138, O139, and O141 contained a principle (edema disease principle) which induced edema disease in swine. All freeze-thaw lysates contained endotoxic activity that tended to obscure the edema disease syndrome and methods were developed to reduce such activity. Freeze-thaw lysates prepared from E. coli O139 induced the most characteristic edema disease syndrome. Partially purified edema disease principle prepared from O139 freeze-thaw lysates by sequential precipitation with ammonium sulphate and streptomycin sulphate had increased specific activity with markedly reduced endotoxic activity. This material was insoluble at acidic pH but readily soluble at alkaline pH. The effective molecular weight of edema disease principle, based on retention and filtration properties of diaflo membranes, appeared to be greater than 50,000 and less than 100,000. The biological activity of edema disease principle was thermolabile. Sodium deoxycholate treatment of edema disease principle further reduced endotoxic activity. A thermolabile, ammonium sulphate precipitable material was prepared from E. coli O139 that induced a predictable syndrome which resembled edema disease clinically and pathologically following intravenous inoculation in pigs. PMID:4272954

Involvement of tumour necrosis factor-α-related apoptosis-inducing ligand in enhanced cytotoxicity of lipopolysaccharide-stimulated dendritic cells to activated T cells

PubMed Central

Yu, Yizhi; Liu, Shuxun; Wang, Wenya; Song, Wengang; Zhang, Minghui; Zhang, Weiping; Qin, Zhihai; Cao, Xuetao

2002-01-01

Dendritic cells (DC) are potent antigen-presenting cells (APC) specialized in T-cell mediated immune responses, and also play critical roles in the homeostasis of T cells for controlling immune responses. In the present study, we demonstrated that during mouse bone-marrow-derived DC activation of ovalbumin (OVA)-specific Ia-kb-restricted T hybridoma cells, MF2.2D9 and OVA257–264-specific H-2kb-restricted RF33.70 T cells, respectively, both hybridomas undergo cell death, partially mediated via apoptotic ligand–tumour necrosis factor-α (TNF-α)-related apoptosis-inducing ligand (TRAIL). Lipopolysaccharide enhanced the cytotoxic effect on the two activated T hybridoma cells, which was correlated with up-regulation of TRAIL-expression on DC to some extent. The activation of caspase-3 in activated T hybridoma cells cocultured with DC contributed to the programmed cell death pathway T cells underwent. Therefore, our results show that activation-induced cell death of T hybridoma cells can be influenced by DC, suggesting that DC may be involved in elimination of activated T cells at the end of primary immune responses. PMID:12100718

Involvement of tumour necrosis factor-alpha-related apoptosis-inducing ligand in enhanced cytotoxicity of lipopolysaccharide-stimulated dendritic cells to activated T cells.

PubMed

Yu, Yizhi; Liu, Shuxun; Wang, Wenya; Song, Wengang; Zhang, Minghui; Zhang, Weiping; Qin, Zhihai; Cao, Xuetao

2002-07-01

Dendritic cells (DC) are potent antigen-presenting cells (APC) specialized in T-cell mediated immune responses, and also play critical roles in the homeostasis of T cells for controlling immune responses. In the present study, we demonstrated that during mouse bone-marrow-derived DC activation of ovalbumin (OVA)-specific Ia-kb-restricted T hybridoma cells, MF2.2D9 and OVA257-264-specific H-2kb-restricted RF33.70 T cells, respectively, both hybridomas undergo cell death, partially mediated via apoptotic ligand-tumour necrosis factor-alpha (TNF-alpha)-related apoptosis-inducing ligand (TRAIL). Lipopolysaccharide enhanced the cytotoxic effect on the two activated T hybridoma cells, which was correlated with up-regulation of TRAIL-expression on DC to some extent. The activation of caspase-3 in activated T hybridoma cells cocultured with DC contributed to the programmed cell death pathway T cells underwent. Therefore, our results show that activation-induced cell death of T hybridoma cells can be influenced by DC, suggesting that DC may be involved in elimination of activated T cells at the end of primary immune responses.

Manganese-induced Neurotoxicity: From C. elegans to Humans

PubMed Central

Chen, Pan; Chakraborty, Sudipta; Peres, Tanara V.; Bowman, Aaron B.; Aschner, Michael

2014-01-01

Manganese (Mn) is one of the most abundant metals on the earth. It is required for normal cellular activities, but overexposure leads to toxicity. Neurons are more susceptible to Mn-induced toxicity than other cells, and accumulation of Mn in the brain results in Manganism that presents with Parkinson's disease (PD)-like symptoms. In the last decade, a number of Mn transporters have been identified, which improves our understanding of Mn transport in and out of cells. However, the mechanism of Mn-induced neurotoxicity is only partially uncovered, with further research needed to explore the whole picture of Mn-induced toxicity. In this review, we will address recent progress in Mn-induced neurotoxicity from C. elegans to humans, and explore future directions that will help understand the mechanisms of its neurotoxicity. PMID:25893090

Reactive Oxygen and Nitrogen Species Regulate Inducible Nitric Oxide Synthase Function Shifting the Balance of Nitric Oxide and Superoxide Production

PubMed Central

Sun, Jian; Druhan, Lawrence J.; Zweier, Jay L.

2014-01-01

Inducible NOS (iNOS) is induced in diseases associated with inflammation and oxidative stress, and questions remain regarding its regulation. We demonstrate that reactive oxygen / nitrogen species (ROS/RNS) dose-dependently regulate iNOS function. Tetrahydrobiopterin (BH4)-replete iNOS was exposed to increasing concentrations of ROS/RNS and activity was measured with and without subsequent BH4 addition. Peroxynitrite (ONOO−) produced the greatest change in NO generation rate, ~95% decrease, and BH4 only partially restored this loss of activity. Superoxide (O2.−) greatly decreased NO generation, however, BH4 addition restored this activity. Hydroxyl radical (.OH) mildly decreases NO generation in a BH4-dependent manner. iNOS was resistant to H2O2 with only slightly decreased NO generation with up to millimolar concentrations. In contrast to the inhibition of NO generation, ROS enhanced O2.− production from iNOS, while ONOO− had the opposite effect. Thus, ROS promote reversible iNOS uncoupling, while ONOO− induces irreversible enzyme inactivation and decreases both NO and O2.− production. PMID:19932078

Apitherapy products enhance the recovery of CCL4-induced hepatic damages in rats.

PubMed

Saral, Özlem; Yildiz, Oktay; Aliyazicioğlu, Rezzan; Yuluğ, Esin; Canpolat, Sinan; Öztürk, Ferhat; Kolayli, Sevgi

2016-01-05

Our objective was to identify the antioxidant properties of honeybee products from Turkey, chestnut honey, pollen, propolis, and royal jelly, and their hepatoprotective activity against CCl4-induced hepatic damage in rats. Animals were fed with honeybee products for 7 days following CCl4 injection. Development of liver damage and oxidative stress were monitored by measuring the activities of the enzymes alanine transaminase, aspartate transaminase, malondialdehyde, superoxide dismutase, and catalase. Antioxidant capacities of the bee products were identified using FRAP and DPPH assays, as well as by measuring total phenolic and flavonoid contents. The antioxidant activities of the honeybee products were highest in propolis, followed, in order, by pollen, honey, and royal jelly. Despite their different levels of antioxidant capacity, their roles in the prevention of liver damage induced by CCl4 were very similar, which can be explained through their bioavailability to the treated animals. Our results suggest that honey, propolis, pollen, and royal jelly significantly enhanced the healing of CCl4-induced liver damage, partially due to their antioxidant properties and bioavailability.

Methamphetamine-induced neurotoxicity linked to UPS dysfunction and autophagy related changes that can be modulated by PKCδ in dopaminergic neuronal cells

PubMed Central

Lin, Mengshien; Shivalingappa, Prashanth Chandramani; Jin, Huajun; Ghosh, Anamitra; Anantharam, Vellareddy; Ali, Syed; Kanthasamy, Anumantha G.; Kanthasamy, Arthi

2012-01-01

A compromised protein degradation machinery has been implicated in methamphetamine (MA)-induced neurodegeneration. However, the signaling mechanisms that induce autophagy and UPS dysfunction are not well understood. The present study investigates the contributions of PKC delta (PKCδ) mediated signaling events in MA-induced autophagy, UPS dysfunction and cell death. Using an in vitro mesencephalic dopaminergic cell culture model, we demonstrate that MA-induced early induction of autophagy is associated with reduction in proteasomal function and concomitant dissipation of mitochondrial membrane potential (MMP), followed by significantly increased of PKCδ activation, caspase-3 activation, accumulation of ubiquitin positive aggregates and microtubule associated light chain-3 (LC3-II) levels. Interestingly, siRNA mediated knockdown of PKCδ or overexpression of cleavage resistant mutant of PKCδ dramatically reduced MA-induced autophagy, proteasomal function, and associated accumulation of ubiquitinated protein aggregates, which closely paralleled cell survival. Importantly, when autophagy was inhibited either pharmacologically (3-MA) or genetically (siRNA mediated silencing of LC3), the dopaminergic cells became sensitized to MA-induced apoptosis through caspase-3 activation. Conversely, overexpression of LC3 partially protected against MA-induced apoptotic cell death, suggesting a neuroprotective role for autophagy in MA-induced neurotoxicity. Notably, rat striatal tissue isolated from MA treated rats also exhibited elevated LC3-II, ubiquitinated protein levels, and PKCδ cleavage. Taken together, our data demonstrate that MA-induced autophagy serves as an adaptive strategy for inhibiting mitochondria mediated apoptotic cell death and degradation of aggregated proteins. Our results also suggest that the sustained activation of PKCδ leads to UPS dysfunction, resulting in the activation of caspase-3 mediated apoptotic cell death in the nigrostriatal dopaminergic system. PMID:22445524

Antioxidative Role of Hatikana (Leea macrophylla Roxb.) Partially Improves the Hepatic Damage Induced by CCl4 in Wistar Albino Rats

PubMed Central

Akhter, Samina; Rahman, Md. Atiar; Aklima, Jannatul; Hasan, Md. Rakibul; Hasan Chowdhury, J. M. Kamirul

2015-01-01

This research investigated the protective role of Leea macrophylla extract on CCl4-induced acute liver injury in rats. Different fractions of Leea macrophylla (Roxb.) crude extract were subjected to analysis for antioxidative effects. Rats were randomly divided into four groups as normal control, hepatic control, and reference control (silymarin) group and treatment group. Evaluations were made for the effects of the fractions on serum enzymes and biochemical parameters of CCl4-induced albino rat. Histopathological screening was also performed to evaluate the changes of liver tissue before and after treatment. Different fractions of Leea macrophylla showed very potent 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect, FeCl3 reducing effect, superoxide scavenging effect, and iron chelating effect. Carbon tetrachloride induction increased the level of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) and other biochemical parameters such as lipid profiles, total protein, and CK-MB. In contrast, treatment of Leea macrophylla reduced the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities as well as biochemical parameters activities. L. macrophylla partially restored the lipid profiles, total protein, and CK-MB. Histopathology showed the treated liver towards restoration. Results evidenced that L. macrophylla can be prospective source of hepatic management in liver injury. PMID:26221590

The Epiphytic Fungus Pseudozyma aphidis Induces Jasmonic Acid- and Salicylic Acid/Nonexpressor of PR1-Independent Local and Systemic Resistance1[C][W

PubMed Central

Buxdorf, Kobi; Rahat, Ido; Gafni, Aviva; Levy, Maggie

2013-01-01

Pseudozyma spp. are yeast-like fungi, classified in the Ustilaginales, which are mostly epiphytic or saprophytic and are not pathogenic to plants. Several Pseudozyma species have been reported to exhibit biological activity against powdery mildews. However, previous studies have reported that Pseudozyma aphidis, which can colonize plant surfaces, is not associated with the ‎‎collapse of powdery ‎mildew colonies. In this report, we describe a novel P. aphidis strain and study its interactions with its plant host and the plant pathogen Botrytis cinerea. This isolate was found to secrete extracellular metabolites that inhibit various fungal pathogens in vitro and significantly reduce B. cinerea infection in vivo. Moreover, P. aphidis sensitized Arabidopsis (Arabidopsis thaliana) plants’ defense machinery via local and systemic induction of PATHOGENESIS-RELATED1 (PR1) and PLANT DEFENSIN1.2 (PDF1.2) expression. P. aphidis also reduced B. cinerea infection, locally and systemically, in Arabidopsis mutants impaired in jasmonic acid (JA) or salicylic acid (SA) signaling. Thus, in addition to direct inhibition, P. aphidis may inhibit B. cinerea infection via induced resistance in a manner independent of SA, JA, and Nonexpressor of PR1 (NPR1). P. aphidis primed the plant defense machinery and induced stronger activation of PDF1.2 after B. cinerea infection. Finally, P. aphidis fully or partially reconstituted PR1 and PDF1.2 expression in npr1-1 mutant and in plants with the SA hydroxylase NahG transgene, but not in a jasmonate resistant1-1 mutant, after B. cinerea infection, suggesting that P. aphidis can bypass the SA/NPR1, but not JA, pathway to activate PR genes. Thus, either partial gene activation is sufficient to induce resistance, or the resistance is not directed solely through PR1 and PDF1.2 but probably through other pathogen-resistance genes or pathways as well. PMID:23388119

The epiphytic fungus Pseudozyma aphidis induces jasmonic acid- and salicylic acid/nonexpressor of PR1-independent local and systemic resistance.

PubMed

Buxdorf, Kobi; Rahat, Ido; Gafni, Aviva; Levy, Maggie

2013-04-01

Pseudozyma spp. are yeast-like fungi, classified in the Ustilaginales, which are mostly epiphytic or saprophytic and are not pathogenic to plants. Several Pseudozyma species have been reported to exhibit biological activity against powdery mildews. However, previous studies have reported that Pseudozyma aphidis, which can colonize plant surfaces, is not associated with the collapse of powdery mildew colonies. In this report, we describe a novel P. aphidis strain and study its interactions with its plant host and the plant pathogen Botrytis cinerea. This isolate was found to secrete extracellular metabolites that inhibit various fungal pathogens in vitro and significantly reduce B. cinerea infection in vivo. Moreover, P. aphidis sensitized Arabidopsis (Arabidopsis thaliana) plants' defense machinery via local and systemic induction of pathogenesis-related1 (PR1) and plant defensin1.2 (PDF1.2) expression. P. aphidis also reduced B. cinerea infection, locally and systemically, in Arabidopsis mutants impaired in jasmonic acid (JA) or salicylic acid (SA) signaling. Thus, in addition to direct inhibition, P. aphidis may inhibit B. cinerea infection via induced resistance in a manner independent of SA, JA, and Nonexpressor of PR1 (NPR1). P. aphidis primed the plant defense machinery and induced stronger activation of PDF1.2 after B. cinerea infection. Finally, P. aphidis fully or partially reconstituted PR1 and PDF1.2 expression in npr1-1 mutant and in plants with the SA hydroxylase NahG transgene, but not in a jasmonate resistant1-1 mutant, after B. cinerea infection, suggesting that P. aphidis can bypass the SA/NPR1, but not JA, pathway to activate PR genes. Thus, either partial gene activation is sufficient to induce resistance, or the resistance is not directed solely through PR1 and PDF1.2 but probably through other pathogen-resistance genes or pathways as well.

Partially silencing brain toll-like receptor 4 prevents in part left ventricular remodeling with sympathoinhibition in rats with myocardial infarction-induced heart failure.

PubMed

Ogawa, Kiyohiro; Hirooka, Yoshitaka; Kishi, Takuya; Ide, Tomomi; Sunagawa, Kenji

2013-01-01

Left ventricular (LV) remodeling and activation of sympathetic nervous system (SNS) are cardinal features of heart failure. We previously demonstrated that enhanced central sympathetic outflow is associated with brain toll-like receptor 4 (TLR4) probably mediated by brain angiotensin II type 1 receptor in mice with myocardial infarction (MI)-induced heart failure. The purpose of the present study was to examine whether silencing brain TLR4 could prevent LV remodeling with sympathoinhibition in MI-induced heart failure. MI-induced heart failure model rats were created by ligation of left coronary artery. The expression level of TLR4 in brainstem was significantly higher in MI-induced heart failure treated with intracerebroventricular (ICV) injection of hGAPDH-SiRNA than in sham. TLR4 in brainstem was significantly lower in MI-induced heart failure treated with ICV injection of TLR4-SiRNA than in that treated with ICV injection of hGAPDH-SiRNA. Lung weight, urinary norepinephrine excretion, and LV end-diastolic pressure were significantly lower and LV dimension was significantly smaller in MI-induced heart failure treated with TLR4-SiRNA than in that treated with hGAPDH-SiRNA for 2 weeks. Partially silencing brain TLR4 by ICV injection of TLR4-SiRNA for 2 weeks could in part prevent LV remodeling with sympathoinhibition in rats with MI-induced heart failure. Brain TLR4 has a potential to be a target of the treatment for MI-induced heart failure.

Characterisation of the vasodilation effects of DHA and EPA, n-3 PUFAs (fish oils), in rat aorta and mesenteric resistance arteries.

PubMed

Limbu, Roshan; Cottrell, Graeme S; McNeish, Alister J

2018-01-01

Increasing evidence suggests that the omega-3 polyunsaturated acids (n-3 PUFA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are beneficial to cardiovascular health, promoting relaxation of vascular smooth muscle cells and vasodilation. Numerous studies have attempted to study these responses, but to date there has not been a systematic characterisation of both DHA and EPA mediated vasodilation in conduit and resistance arteries. Therefore, we aimed to fully characterise the n-3 PUFA-induced vasodilation pathways in rat aorta and mesenteric artery. Wire myography was used to measure the vasomotor responses of freshly dissected rat mesenteric artery and aorta. Arteries were pre-constricted with U46619 and cumulative concentrations of either DHA or EPA (10 nM-30 μM) were added. The mechanisms by which n-3 PUFA relaxed arteries were investigated using inhibitors of vasodilator pathways, which include: nitric oxide synthase (NOS; L-NAME), cycloxygenase (COX; indomethacin), cytochrome P450 epoxygenase (CYP450; clotrimazole); and calcium-activated potassium channels (KCa), SKCa (apamin), IKCa (TRAM-34) and BKCa (paxilline). Both DHA- and EPA-induced relaxations were partially inhibited following endothelium removal in rat mesenteric arteries. Similarly, in aorta EPA-induced relaxation was partially suppressed due to endothelium removal. CYP450 also contributed to EPA-induced relaxation in mesenteric artery. Inhibition of IKCa partially attenuated DHA-induced relaxation in aorta and mesenteric artery along with EPA-induced relaxation in mesenteric artery. Furthermore, this inhibition of DHA- and EPA-induced relaxation was increased following the additional blockade of BKCa in these arteries. This study provides evidence of heterogeneity in the vasodilation mechanisms of DHA and EPA in different vascular beds. Our data also demonstrates that endothelium removal has little effect on relaxations produced by either PUFA. We demonstrate IKCa and BKCa are involved in DHA-induced relaxation in rat aorta and mesenteric artery; and EPA-induced relaxation in rat mesenteric artery only. CYP450 derived metabolites of EPA may also be involved in BKCa dependent relaxation. To our knowledge this is the first study indicating the involvement of IKCa in n-3 PUFA mediated relaxation.

Characterisation of the vasodilation effects of DHA and EPA, n-3 PUFAs (fish oils), in rat aorta and mesenteric resistance arteries

PubMed Central

Limbu, Roshan; Cottrell, Graeme S.

2018-01-01

Background and purpose Increasing evidence suggests that the omega-3 polyunsaturated acids (n-3 PUFA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are beneficial to cardiovascular health, promoting relaxation of vascular smooth muscle cells and vasodilation. Numerous studies have attempted to study these responses, but to date there has not been a systematic characterisation of both DHA and EPA mediated vasodilation in conduit and resistance arteries. Therefore, we aimed to fully characterise the n-3 PUFA-induced vasodilation pathways in rat aorta and mesenteric artery. Methods Wire myography was used to measure the vasomotor responses of freshly dissected rat mesenteric artery and aorta. Arteries were pre-constricted with U46619 and cumulative concentrations of either DHA or EPA (10 nM-30 μM) were added. The mechanisms by which n-3 PUFA relaxed arteries were investigated using inhibitors of vasodilator pathways, which include: nitric oxide synthase (NOS; L-NAME), cycloxygenase (COX; indomethacin), cytochrome P450 epoxygenase (CYP450; clotrimazole); and calcium-activated potassium channels (KCa), SKCa (apamin), IKCa (TRAM-34) and BKCa (paxilline). Results Both DHA- and EPA-induced relaxations were partially inhibited following endothelium removal in rat mesenteric arteries. Similarly, in aorta EPA-induced relaxation was partially suppressed due to endothelium removal. CYP450 also contributed to EPA-induced relaxation in mesenteric artery. Inhibition of IKCa partially attenuated DHA-induced relaxation in aorta and mesenteric artery along with EPA-induced relaxation in mesenteric artery. Furthermore, this inhibition of DHA- and EPA-induced relaxation was increased following the additional blockade of BKCa in these arteries. Conclusions This study provides evidence of heterogeneity in the vasodilation mechanisms of DHA and EPA in different vascular beds. Our data also demonstrates that endothelium removal has little effect on relaxations produced by either PUFA. We demonstrate IKCa and BKCa are involved in DHA-induced relaxation in rat aorta and mesenteric artery; and EPA-induced relaxation in rat mesenteric artery only. CYP450 derived metabolites of EPA may also be involved in BKCa dependent relaxation. To our knowledge this is the first study indicating the involvement of IKCa in n-3 PUFA mediated relaxation. PMID:29394279

Leptin reverses corticosterone-induced inhibition of neural stem cell proliferation through activating the NR2B subunits of NMDA receptors

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

Shi, Wen-Zhu; Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853; Miao, Yu-Liang

Highlights: • Leptin promotes the proliferation of neural stem cells isolated from embryonic mouse hippocampus. • Leptin reverses corticosterone-induced inhibition of neural stem cell proliferation. • The effects of leptin are partially mediated by upregulating NR2B subunits. - Abstract: Corticosterone inhibits the proliferation of hippocampal neural stem cells (NSCs). The removal of corticosterone-induced inhibition of NSCs proliferation has been reported to contribute to neural regeneration. Leptin has been shown to regulate brain development, improve angiogenesis, and promote neural regeneration; however, its effects on corticosterone-induced inhibition of NSCs proliferation remain unclear. Here we reported that leptin significantly promoted the proliferation ofmore » hippocampal NSCs in a concentration-dependent pattern. Also, leptin efficiently reversed the inhibition of NSCs proliferation induced by corticosterone. Interestingly, pre-treatment with non-specific NMDA antagonist MK-801, specific NR2B antagonist Ro 25-6981, or small interfering RNA (siRNA) targeting NR2B, significantly blocked the effect of leptin on corticosterone-induced inhibition of NSCs proliferation. Furthermore, corticosterone significantly reduced the protein expression of NR2B, whereas pre-treatment with leptin greatly reversed the attenuation of NR2B expression caused by corticosterone in cultured hippocampal NSCs. Our findings demonstrate that leptin reverses the corticosterone-induced inhibition of NSCs proliferation. This process is, at least partially mediated by increased expression of NR2B subunits of NMDA receptors.« less

Nonlinear force-length relationship in the ADP-induced contraction of skeletal myofibrils.

PubMed

Shimamoto, Yuta; Kono, Fumiaki; Suzuki, Madoka; Ishiwata, Shin'ichi

2007-12-15

The regulatory mechanism of sarcomeric activity has not been fully clarified yet because of its complex and cooperative nature, which involves both Ca(2+) and cross-bridge binding to the thin filament. To reveal the mechanism of regulation mediated by the cross-bridges, separately from the effect of Ca(2+), we investigated the force-sarcomere length (SL) relationship in rabbit skeletal myofibrils (a single myofibril or a thin bundle) at SL > 2.2 microm in the absence of Ca(2+) at various levels of activation by exogenous MgADP (4-20 mM) in the presence of 1 mM MgATP. The individual SLs were measured by phase-contrast microscopy to confirm the homogeneity of the striation pattern of sarcomeres during activation. We found that at partial activation with 4-8 mM MgADP, the developed force nonlinearly depended on the length of overlap between the thick and the thin filaments; that is, contrary to the maximal activation, the maximal active force was generated at shorter overlap. Besides, the active force became larger, whereas this nonlinearity tended to weaken, with either an increase in [MgADP] or the lateral osmotic compression of the myofilament lattice induced by the addition of a macromolecular compound, dextran T-500. The model analysis, which takes into account the [MgADP]- and the lattice-spacing-dependent probability of cross-bridge formation, was successfully applied to account for the force-SL relationship observed at partial activation. These results strongly suggest that the cross-bridge works as a cooperative activator, the function of which is highly sensitive to as little as

TEC protein tyrosine kinase is involved in the Erk signaling pathway induced by HGF

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

Li, Feifei; Jiang, Yinan; Zheng, Qiping

Research highlights: {yields} TEC is rapidly tyrosine-phosphorylated and activated by HGF-stimulation in vivo or after partial hepatectomy in mice. {yields} TEC enhances the activity of Elk and serum response element (SRE) in HGF signaling pathway in hepatocyte. {yields} TEC promotes hepatocyte proliferation through the Erk-MAPK pathway. -- Abstract: Background/aims: TEC, a member of the TEC family of non-receptor type protein tyrosine kinases, has recently been suggested to play a role in hepatocyte proliferation and liver regeneration. This study aims to investigate the putative mechanisms of TEC kinase regulation of hepatocyte differentiation, i.e. to explore which signaling pathway TEC is involvedmore » in, and how TEC is activated in hepatocyte after hepatectomy and hepatocyte growth factor (HGF) stimulation. Methods: We performed immunoprecipitation (IP) and immunoblotting (IB) to examine TEC tyrosine phosphorylation after partial hepatectomy in mice and HGF stimulation in WB F-344 hepatic cells. The TEC kinase activity was determined by in vitro kinase assay. Reporter gene assay, antisense oligonucleotide and TEC dominant negative mutant (TEC{sup KM}) were used to examine the possible signaling pathways in which TEC is involved. The cell proliferation rate was evaluated by {sup 3}H-TdR incorporation. Results: TEC phosphorylation and kinase activity were increased in 1 h after hepatectomy or HGF treatment. TEC enhanced the activity of Elk and serum response element (SRE). Inhibition of MEK1 suppressed TEC phosphorylation. Blocking TEC activity dramatically decreased the activation of Erk. Reduced TEC kinase activity also suppressed the proliferation of WB F-344 cells. These results suggest TEC is involved in the Ras-MAPK pathway and acts between MEK1 and Erk. Conclusions: TEC promotes hepatocyte proliferation and regeneration and is involved in HGF-induced Erk signaling pathway.« less

Heterozygote loss of ACE2 is sufficient to increase the susceptibility to heart disease.

PubMed

Wang, Wang; Patel, Vaibhav B; Parajuli, Nirmal; Fan, Dong; Basu, Ratnadeep; Wang, Zuocheng; Ramprasath, Tharmarajan; Kassiri, Zamaneh; Penninger, Josef M; Oudit, Gavin Y

2014-08-01

Angiotensin-converting enzyme 2 (ACE2) metabolizes Ang II into Ang 1-7 thereby negatively regulating the renin-angiotensin system. However, heart disease in humans and in animal models is associated with only a partial loss of ACE2. ACE2 is an X-linked gene; and as such, we tested the clinical relevance of a partial loss of ACE2 by using female ACE2(+/+) (wildtype) and ACE2(+/-) (heterozygote) mice. Pressure overload in ACE2(+/-) mice resulted in greater LV dilation and worsening systolic and diastolic dysfunction. These changes were associated with increased myocardial fibrosis, hypertrophy, and upregulation of pathological gene expression. In response to Ang II infusion, there was increased NADPH oxidase activity and myocardial fibrosis resulting in the worsening of Ang II-induced diastolic dysfunction with a preserved systolic function. Ang II-mediated cellular effects in cultured adult ACE2(+/-) cardiomyocytes and cardiofibroblasts were exacerbated. Ang II-mediated pathological signaling worsened in ACE2(+/-) hearts characterized by an increase in the phosphorylation of ERK1/2 and JNK1/2 and STAT-3 pathways. The ACE2(+/-) mice showed an exacerbated pressor response with increased vascular fibrosis and stiffness. Vascular superoxide and nitrotyrosine levels were increased in ACE2(+/-) vessels consistent with increased vascular oxidative stress. These changes occurred with increased renal fibrosis and superoxide production. Partial heterozygote loss of ACE2 is sufficient to increase the susceptibility to heart disease secondary to pressure overload and Ang II infusion. Heart disease in humans with idiopathic dilated cardiomyopathy is associated with a partial loss of ACE2. Heterozygote female ACE2 mutant mice showed enhanced susceptibility to pressure overload-induced heart disease. Heterozygote female ACE2 mutant mice showed enhanced susceptibility to Ang II-induced heart and vascular diseases. Partial loss of ACE2 is sufficient to enhance the susceptibility to heart disease.

Cytokines Alter Glucocorticoid Receptor Phosphorylation in Airway Cells

PubMed Central

Bouazza, Belaid; Krytska, Kateryna; Debba-Pavard, Manel; Amrani, Yassine; Honkanen, Richard E.; Tran, Jennifer

2012-01-01

Corticosteroid insensitivity (CSI) represents a profound challenge in managing patients with asthma. We recently demonstrated that short exposure of airway smooth muscle cells (ASMCs) to proasthmatic cytokines drastically reduced their responsiveness to glucocorticoids (GCs), an effect that was partially mediated via interferon regulatory factor-1, suggesting the involvement of additional mechanisms (Am J Respir Cell Mol Biol 2008;38:463–472). Although GC receptor (GR) can be phosphorylated at multiple serines in the N-terminal region, the major phosphorylation sites critical for GR transcriptional activity are serines 211 (Ser211) and 226 (Ser226). We tested the novel hypothesis that cytokine-induced CSI in ASMCs is due to an impaired GR phosphorylation. Cells were treated with TNF-α (10 ng/ml) and IFN-γ (500 UI/ml) for 6 hours and/or fluticasone (100 nm) added 2 hours before. GR was constitutively phosphorylated at Ser226 but not at Ser211 residues. Cytokines dramatically suppressed fluticasone-induced phosphorylation of GR on Ser211 but not on Ser226 residues while increasing the expression of Ser/Thr protein phosphatase (PP)5 but not that of PP1 or PP2A. Transfection studies using a reporter construct containing GC responsive elements showed that the specific small interfering RNA–induced mRNA knockdown of PP5, but not that of PP1 or PP2A, partially prevented the cytokine suppressive effects on GR-meditated transactivation activity. Similarly, cytokines failed to inhibit GC-induced GR-Ser211 phosphorylation when expression of PP5 was suppressed. We propose that the novel mechanism that proasthmatic cytokine-induced CSI in ASMCs is due, in part, to PP5-mediated impairment of GR-Ser211 phosphorylation. PMID:22592921

Hydrogen sulphide decreases IL-1β-induced activation of fibroblast-like synoviocytes from patients with osteoarthritis

PubMed Central

Sieghart, Daniela; Liszt, Melissa; Wanivenhaus, Axel; Bröll, Hans; Kiener, Hans; Klösch, Burkhard; Steiner, Günter

2015-01-01

Balneotherapy employing sulphurous thermal water is still applied to patients suffering from diseases of musculoskeletal system like osteoarthritis (OA) but evidence for its clinical effectiveness is scarce. Since the gasotransmitter hydrogen sulphide (H2S) seems to affect cells involved in degenerative joint diseases, it was the objective of this study to investigate the effects of exogenous H2S on fibroblast-like synoviocytes (FLS), which are key players in OA pathogenesis being capable of producing pro-inflammatory cytokines and matrix degrading enzymes. To address this issue primary FLS derived from OA patients were stimulated with IL-1β and treated with the H2S donor NaHS. Cellular responses were analysed by ELISA, quantitative real-time PCR, phospho-MAPkinase array and Western blotting. Treatment-induced effects on cellular structure and synovial architecture were investigated in three-dimensional extracellular matrix micromasses. NaHS treatment reduced both spontaneous and IL-1β-induced secretion of IL-6, IL-8 and RANTES in different experimental settings. In addition, NaHS treatment reduced the expression of matrix metallo-proteinases MMP-2 and MMP-14. IL-1β induced the phosphorylation of several MAPkinases. NaHS treatment partially reduced IL-1β-induced activation of several MAPK whereas it increased phosphorylation of pro-survival factor Akt1/2. When cultured in spherical micromasses, FLS intentionally established a synovial lining layer-like structure; stimulation with IL-1β altered the architecture of micromasses leading to hyperplasia of the lining layer which was completely inhibited by concomitant exposure to NaHS. These data suggest that H2S partially antagonizes IL-1β stimulation via selective manipulation of the MAPkinase and the PI3K/Akt pathways which may encourage development of novel drugs for treatment of OA. PMID:25312962

Imidacloprid Promotes High Fat Diet-Induced Adiposity in Female C57BL/6J Mice and Enhances Adipogenesis in 3T3-L1 Adipocytes via the AMPKα-Mediated Pathway.

PubMed

Sun, Quancai; Qi, Weipeng; Xiao, Xiao; Yang, Szu-Hao; Kim, Daeyoung; Yoon, Kyong Sup; Clark, John M; Park, Yeonhwa

2017-08-09

Imidacloprid, a neonicotinoid insecticide, was previously reported to enhance adipogenesis and resulted in insulin resistance in cell culture models. It was also reported to promote high fat diet-induced obesity and insulin resistance in male C57BL/6J mice. Thus, the goal of the present study was to determine the effects of imidacloprid and dietary fat interaction on the development of adiposity and insulin resistance in female C57BL/6J mice. Mice were fed with a low (4% w/w) or high fat (20% w/w) diet containing imidacloprid (0.06, 0.6, or 6 mg/kg bw/day) for 12 weeks. Mice fed with imidacloprid (0.6 mg/kg bw/day) significantly enhanced high fat diet-induced weight gain and adiposity. Treatment with imidacloprid significantly increased serum insulin levels with high fat diet without effects on other markers of glucose homeostasis. AMPKα activation was significantly inhibited by 0.6 and 6 mg imidacloprid/kg bw/day in white adipose tissue. Moreover, AMPKα activation with 5-aminoimidazole-4-carboxamide ribonucleotide abolished the effects of imidacloprid (10 μM) on enhanced adipogenesis in 3T3-L1 adipocytes. N-Acetyl cysteine also partially reversed the effects of imidacloprid on reduced phosphorylation of protein kinase B (AKT) in C2C12 myotubes. These results indicate that imidacloprid may potentiate high fat diet-induced adiposity in female C57BL/6J mice and enhance adipogenesis in 3T3-L1 adipocytes via the AMPKα-mediated pathway. Imidacloprid might also influence glucose homeostasis partially by inducing cellular oxidative stress in C2C12 myotubes.

Imidacloprid Promotes High Fat Diet-Induced Adiposity in Female C57BL/6J Mice and Enhances Adipogenesis in 3T3-L1 Adipocytes via the AMPKα-Mediated Pathway

PubMed Central

2017-01-01

Imidacloprid, a neonicotinoid insecticide, was previously reported to enhance adipogenesis and resulted in insulin resistance in cell culture models. It was also reported to promote high fat diet-induced obesity and insulin resistance in male C57BL/6J mice. Thus, the goal of the present study was to determine the effects of imidacloprid and dietary fat interaction on the development of adiposity and insulin resistance in female C57BL/6J mice. Mice were fed with a low (4% w/w) or high fat (20% w/w) diet containing imidacloprid (0.06, 0.6, or 6 mg/kg bw/day) for 12 weeks. Mice fed with imidacloprid (0.6 mg/kg bw/day) significantly enhanced high fat diet-induced weight gain and adiposity. Treatment with imidacloprid significantly increased serum insulin levels with high fat diet without effects on other markers of glucose homeostasis. AMPKα activation was significantly inhibited by 0.6 and 6 mg imidacloprid/kg bw/day in white adipose tissue. Moreover, AMPKα activation with 5-aminoimidazole-4-carboxamide ribonucleotide abolished the effects of imidacloprid (10 μM) on enhanced adipogenesis in 3T3-L1 adipocytes. N-Acetyl cysteine also partially reversed the effects of imidacloprid on reduced phosphorylation of protein kinase B (AKT) in C2C12 myotubes. These results indicate that imidacloprid may potentiate high fat diet-induced adiposity in female C57BL/6J mice and enhance adipogenesis in 3T3-L1 adipocytes via the AMPKα-mediated pathway. Imidacloprid might also influence glucose homeostasis partially by inducing cellular oxidative stress in C2C12 myotubes. PMID:28704996

Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy

PubMed Central

Zhang, Cong; Bélanger, Samuel; Pouliot, Philippe; Lesage, Frédéric

2015-01-01

In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure. PMID:26305777

Involvement of nitric oxide in the mediation of the hypotensive action of the essential oil of Mentha x villosa in normotensive conscious rats.

PubMed

Lahlou, Saad; Magalhães, Pedro Jorge Caldas; Carneiro-Leão, Ricardo Ferreira Lima; Leal-Cardoso, José Henrique

2002-08-01

Recently, we showed that intravenous (i.v.) treatment with the essential oil of Mentha x villosa (EOMV) in pentobarbitone-anaesthetised rats decreased blood pressure; the effect occurred independently of the presence of an operational central autonomic drive to the cardiovascular system. This finding suggested that the hypotensive activity of EOMV may result from its vasodilatory effects directly upon vascular smooth muscle. The present study examines this possibility and whether EOMV-induced hypotension is mediated, at least in part, by an endothelial L-arginine/nitric oxide pathway. In conscious rats, i.v. injections of bolus doses (1 to 20 mg/kg) of EOMV elicited immediate and dose-dependent decreases in mean aortic pressure (MAP) and heart rate (HR). Pretreatment with i.v. hexamethonium (30 mg/kg) reduced the EOMV-induced bradycardia without affecting the hypotension. However, i.v. pretreatment with the nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl (L-NAME, 20 mg/kg), reduced partially, but significantly, the maximal percent decreases in MAP elicited by EOMV without affecting the bradycardia. In rat isolated thoracic aorta preparations, EOMV (1 - 130 microg/ml) induced a concentration-dependent reduction of potassium (60 mM)-induced contraction. This smooth muscle-relaxant activity of EOMV was significantly reduced by the incubation of endothelium-intact rings with L-NAME (20 microM), as evidenced by the significant enhancement in the IC50 for EOMV-induced reduction of potassium-induced contraction (133.8 +/- 26.5 vs. 65.2 +/- 8.2 microg/ml in the absence of L-NAME). Furthermore, the vasorelaxant effects of EOMV in endothelium-denuded aortic rings were also significantly reduced (IC50 = 109 +/- 10 microg/ml), compared to those observed in segments with intact endothelium (IC50 = 61 +/- 13 microg/ml). These results show that i.v. treatment with EOMV dose-dependently decreases blood pressure in conscious rats, and that this action is due to an active vascular relaxation rather than withdrawal of sympathetic tone. Released nitric oxide from vascular endothelial cells appears partially involved in the aortic relaxation induced by EOMV and in turn in the mediation of EOMV-induced hypotension. They further support the concept that EOMV-induced hypotension and bradycardia occurred independently.

Tetraspanin Tspan9 regulates platelet collagen receptor GPVI lateral diffusion and activation

PubMed Central

Haining, Elizabeth J.; Matthews, Alexandra L.; Noy, Peter J.; Romanska, Hanna M.; Harris, Helen J.; Pike, Jeremy; Morowski, Martina; Gavin, Rebecca L.; Yang, Jing; Milhiet, Pierre-Emmanuel; Berditchevski, Fedor; Nieswandt, Bernhard; Poulter, Natalie S.; Watson, Steve P.; Tomlinson, Michael G.

2017-01-01

Abstract The tetraspanins are a superfamily of four-transmembrane proteins, which regulate the trafficking, lateral diffusion and clustering of the transmembrane proteins with which they interact. We have previously shown that tetraspanin Tspan9 is expressed on platelets. Here we have characterised gene-trap mice lacking Tspan9. The mice were viable with normal platelet numbers and size. Tspan9-deficient platelets were specifically defective in aggregation and secretion induced by the platelet collagen receptor GPVI, despite normal surface GPVI expression levels. A GPVI activation defect was suggested by partially impaired GPVI-induced protein tyrosine phosphorylation. In mechanistic experiments, Tspan9 and GPVI co-immunoprecipitated and co-localised, but super-resolution imaging revealed no defects in collagen-induced GPVI clustering on Tspan9-deficient platelets. However, single particle tracking using total internal reflection fluorescence microscopy showed that GPVI lateral diffusion was reduced by approximately 50% in the absence of Tspan9. Therefore, Tspan9 plays a fine-tuning role in platelet activation by regulating GPVI membrane dynamics. PMID:28032533

Protective Effect of Morus alba Leaf Extract on N-Nitrosodiethylamine-induced Hepatocarcinogenesis in Rats.

PubMed

Kujawska, Małgorzata; Ewertowska, Małgorzata; Adamska, Teresa; Ignatowicz, Ewa; Flaczyk, Ewa; Przeor, Monika; Kurpik, Monika; Liebert, Jadwiga Jodynis

The leaves of white mulberry (Morus alba L.) contain various polyphenolic compounds possessing strong antioxidant activity and anticancer potential. This study was designed to investigate the chemopreventive effect of aqueous extract of mulberry leaves against N-nitrosodiethylamine (NDEA)-induced liver carcinogenesis. Wistar rats were divided into four groups: control, mulberry extract-treated, NDEA-treated, and mulberry extract plus NDEA-treated. Mulberry extract was given in the diet (1,000 mg/kg b.w./day); NDEA was given in drinking water. Mulberry extract reduced the incidence of hepatocellular carcinoma, dysplastic nodules, lipid peroxidation, protein carbonyl formation, and DNA degradation. Treatment with mulberry leaf extract along with NDEA challenge did not affect the activity of antioxidant enzymes and glutathione content. Treatment with mulberry leaf extract partially protected the livers of rats from NDEA-induced hepatocarcinogenesis and a direct antioxidant mechanism appears to contribute to its anticarcinogenic activity. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Betaine protects urea-induced denaturation of myosin subfragment-1.

PubMed

Ortiz-Costa, Susana; Sorenson, Martha M; Sola-Penna, Mauro

2008-07-01

We have demonstrated previously that urea inhibits the activity and alters the tertiary structure of skeletal muscle myosin in a biphasic manner. This was attributed to differential effects on its globular and filamentous portion. The inhibition of catalytic activity was counteracted by methylamines. With the aim of comprehending the effects of urea on the catalytic (globular) portion of myosin, this study examines the effects of urea and the countereffects of betaine on the catalytic activity and structure of myosin subfragment-1. It is shown that urea inactivates subfragment-1 in parallel with its ability to induce exposure of the enzyme hydrophobic domains, as assessed using intrinsic and extrinsic fluorescence. Both effects are counteracted by betaine, which alone does not significantly affect subfragment-1. Urea also enhances the accessibility of thiol groups, promotes aggregation and decreases the alpha-helix content of S1, effects that are also counteracted by betaine. We conclude that urea-induced inactivation of the enzyme is caused by partial unfolding of the myosin catalytic domain.

Neurotrophin Promotes Neurite Outgrowth by Inhibiting Rif GTPase Activation Downstream of MAPKs and PI3K Signaling.

PubMed

Tian, Xiaoxia; Yan, Huijuan; Li, Jiayi; Wu, Shuang; Wang, Junyu; Fan, Lifei

2017-01-13

Members of the well-known semaphorin family of proteins can induce both repulsive and attractive signaling in neural network formation and their cytoskeletal effects are mediated in part by small guanosine 5'-triphosphatase (GTPases). The aim of this study was to investigate the cellular role of Rif GTPase in the neurotrophin-induced neurite outgrowth. By using PC12 cells which are known to cease dividing and begin to show neurite outgrowth responding to nerve growth factor (NGF), we found that semaphorin 6A was as effective as nerve growth factor at stimulating neurite outgrowth in PC12 cells, and that its neurotrophic effect was transmitted through signaling by mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3-kinase (PI3K). We further found that neurotrophin-induced neurite formation in PC12 cells could be partially mediated by inhibition of Rif GTPase activity downstream of MAPKs and PI3K signaling. In conclusion, we newly identified Rif as a regulator of the cytoskeletal rearrangement mediated by semaphorins.

Design and Synthesis of Novel Small-molecule Inhibitors of the Hypoxia Inducible Factor Pathway

PubMed Central

Mooring, Suazette Reid; Jin, Hui; Devi, Narra S.; Jabbar, Adnan A.; Kaluz, Stefan; Liu, Yuan; Van Meir, Erwin G.; Wang, Binghe

2012-01-01

Hypoxia, a reduction in partial oxygen pressure, is a salient property of solid tumors. Hypoxia drives malignant progression and metastasis in tumors and participates in tumor resistance to radio- and chemotherapies. Hypoxia activates the hypoxia-inducible factor (HIF) family of transcription factors, which induce target genes that regulate adaptive biological processes such as anaerobic metabolism, cell motility and angiogenesis. Clinical evidence has demonstrated that expression of HIF-1 is strongly associated with poor patient prognosis and activation of HIF-1 contributes to malignant behavior and therapeutic resistance. Consequently, HIF-1 has become an important therapeutic target for inhibition by small molecules. Herein, we describe the design and synthesis of small molecules that inhibit the HIF-1 signaling pathway. Many of these compounds exhibit inhibitory activity in the nanomolar range. Separate mechanistic studies indicate that these inhibitors do not alter HIF-1 levels, but interfere with the HIF-1α/HIF-1β/p300/CBP complex formation by interacting with p300 and CBP. PMID:22032632

A neuroprotective astrocyte state is induced by neuronal signal EphB1 but fails in ALS models.

PubMed

Tyzack, Giulia E; Hall, Claire E; Sibley, Christopher R; Cymes, Tomasz; Forostyak, Serhiy; Carlino, Giulia; Meyer, Ione F; Schiavo, Giampietro; Zhang, Su-Chun; Gibbons, George M; Newcombe, Jia; Patani, Rickie; Lakatos, András

2017-10-27

Astrocyte responses to neuronal injury may be beneficial or detrimental to neuronal recovery, but the mechanisms that determine these different responses are poorly understood. Here we show that ephrin type-B receptor 1 (EphB1) is upregulated in injured motor neurons, which in turn can activate astrocytes through ephrin-B1-mediated stimulation of signal transducer and activator of transcription-3 (STAT3). Transcriptional analysis shows that EphB1 induces a protective and anti-inflammatory signature in astrocytes, partially linked to the STAT3 network. This is distinct from the response evoked by interleukin (IL)-6 that is known to induce both pro inflammatory and anti-inflammatory processes. Finally, we demonstrate that the EphB1-ephrin-B1 pathway is disrupted in human stem cell derived astrocyte and mouse models of amyotrophic lateral sclerosis (ALS). Our work identifies an early neuronal help-me signal that activates a neuroprotective astrocytic response, which fails in ALS, and therefore represents an attractive therapeutic target.

Nitric oxide mitigates arsenic-induced oxidative stress and genotoxicity in Vicia faba L.

PubMed

Shukla, Pratiksha; Singh, A K

2015-09-01

The protective effects of nitric oxide (NO) against arsenic (As)-induced structural disturbances in Vicia faba have been investigated. As treatment (0.25, 0.50, and 1 mM) resulted in a declined growth of V. faba seedlings. Arsenic treatment stimulates the activity of SOD and CAT while the activities of APX and GST content were decreased. The oxidative stress markers such as superoxide radical, hydrogen peroxide and malondialdehyde (lipid peroxidation) contents were enhanced by As. Overall results revealed that significant accumulation of As suppressed growth, photosynthesis, antioxidant enzymes (SOD, CAT, APX, and GST activity), mitotic index, and induction of different chromosomal abnormalities, hence led to oxidative stress. The concentration of SNP (0.02 mM) was very effective in counteracting the adverse effect of As toxicity. These abnormalities use partially or fully reversed by a simultaneous application of As and NO donor and sodium nitroprusside and has an ameliorating effect against As-induced oxidative stress and genotoxicity in V. faba roots.

Calotropin from Asclepias curasavica induces cell cycle arrest and apoptosis in cisplatin-resistant lung cancer cells.

PubMed

Mo, En-Pan; Zhang, Rong-Rong; Xu, Jun; Zhang, Huan; Wang, Xiao-Xiong; Tan, Qiu-Tong; Liu, Fang-Lan; Jiang, Ren-Wang; Cai, Shao-Hui

2016-09-16

Calotropin (M11), an active compound isolated from Asclepias curasavica L., was found to exert strong inhibitory and pro-apoptotic activity specifically against cisplatin-induced resistant non-small cell lung cancer (NSCLC) cells (A549/CDDP). Molecular mechanism study revealed that M11 induced cell cycle arrest at the G2/M phase through down-regulating cyclins, CDK1, CDK2 and up-regulating p53 and p21. Furthermore, M11 accelerated apoptosis through the mitochondrial apoptotic pathway which was accompanied by increase Bax/Bcl-2 ratio, decrease in mitochondrial membrane potential, increase in reactive oxygen species production, activations of caspases 3 and 9 as well as cleavage of poly ADP-ribose polymerase (PARP). The activation and phosphorylation of JNK was also found to be involved in M11-induced apoptosis, and SP610025 (specific JNK inhibitor) partially prevented apoptosis induced by M11. In contrast, all of the effects that M11 induce cell cycle arrest and apoptosis in A549/CDDP cells were not significant in A549 cells. Drugs with higher sensitivity against resistant tumor cells than the parent cells are rather rare. Results of this study supported the potential application of M11 on the non-small lung cancer (NSCLC) with cisplatin resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

Isolation, partial purification and characterization of active polypeptide from the sea anemone Bartholomea annulata.

PubMed

Sánchez-Rodríguez, Judith; Zugasti, Alejandro; Santamaría, Abel; Galván-Arzate, Sonia; Segura-Puertas, Lourdes

2006-08-01

In the sea anemone Bartholomea annulata, four different types of cnidocysts, basitrichous isorhizas, microbasic p-mastigophores, microbasic amastigophores and spirocysts were identified. In relation to the efficacy of different substances to induce discharge of nematocysts we observe that distilled water induced more than 70% of microbasic p-mastigophores to discharge, whereas spirocysts were discharged in a lesser extent (approximately 20%). The median lethal dose (LD50) in mice was found after injection of 700.7 mg protein per kg of body weight from the crude extract. The protein with neurotoxic effect was isolated using low-pressure liquid chromatography. The neurotoxic activity was determined using sea crabs (Ocypode quadrata), injecting 15 microg of crude extract or isolated fraction into the third walking leg, and violent motor activity followed by progressive loss of sensibility to external stimuli, further leading to full paralysis were observed. The active fraction (called V) eluted at 43.9 min.

Energy release, beam attenuation radiation damage, gas production and accumulation of long-lived activity in Pb, Pb-Bi and Hg targets

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

Shubin, Yu.N.

1996-06-01

The calculation and analysis of the nuclei concentrations and long-lived residual radioactivity accumulated in Pb, Pb-Bi and Hg targets irradiated by 800 MeV, 30 mA proton beam have been performed. The dominating components to the total radioactivity of radionuclides resulting from fission and spallation reactions and radiative capture by both target nuclei and accumulated radioactive nuclei for various irradiation and cooling times were analyzed. The estimations of spectral component contributions of neutron and proton fluxes to the accumulated activity were carried out. The contributions of fission products to the targets activity and partial activities of main long-lived fission products tomore » the targets activity and partial activities of main long-lived fission products were evaluated. The accumulation of Po isotopes due to reactions induced by secondary alpha-particles were found to be important for the Pb target as compared with two-step radiative capture. The production of Tritium in the targets and its contribution to the total targets activity was considered in detail. It is found that total activities of both targets are close to one another.« less

Stimulatory Effects of Polysaccharide Fraction from Solanum nigrum on RAW 264.7 Murine Macrophage Cells

PubMed Central

Razali, Faizan Naeem; Ismail, Amirah; Abidin, Nurhayati Zainal; Shuib, Adawiyah Suriza

2014-01-01

The polysaccharide fraction from Solanum nigrum Linne has been shown to have antitumor activity by enhancing the CD4+/CD8+ ratio of the T-lymphocyte subpopulation. In this study, we analyzed a polysaccharide extract of S. nigrum to determine its modulating effects on RAW 264.7 murine macrophage cells since macrophages play a key role in inducing both innate and adaptive immune responses. Crude polysaccharide was extracted from the stem of S. nigrum and subjected to ion-exchange chromatography to partially purify the extract. Five polysaccharide fractions were then subjected to a cytotoxicity assay and a nitric oxide production assay. To further analyze the ability of the fractionated polysaccharide extract to activate macrophages, the phagocytosis activity and cytokine production were also measured. The polysaccharide fractions were not cytotoxic, but all of the fractions induced nitric oxide in RAW 264.7 cells. Of the five fractions tested, SN-ppF3 was the least toxic and also induced the greatest amount of nitric oxide, which was comparable to the inducible nitric oxide synthase expression detected in the cell lysate. This fraction also significantly induced phagocytosis activity and stimulated the production of tumor necrosis factor-α and interleukin-6. Our study showed that fraction SN-ppF3 could classically activate macrophages. Macrophage induction may be the manner in which polysaccharides from S. nigrum are able to prevent tumor growth. PMID:25299340

Porcine endothelium induces DNA-histone complex formation in human whole blood: a harmful effect of histone on coagulation and endothelial activation.

PubMed

Yoo, Hyun Ju; Kim, Ji-Eun; Gu, Ja Yoon; Lee, Sae Bom; Lee, Hyun Joo; Hwang, Ho Young; Hwang, Yoohwa; Kim, Young Tae; Kim, Hyun Kyung

2016-11-01

Neutrophils play a role in xenograft rejection. When neutrophils are stimulated, they eject the DNA-histone complex into the extracellular space, called neutrophil extracellular traps (NET). We investigated whether NET formation actively occurs in the xenograft and contributes to coagulation and endothelial activation. Human whole blood was incubated with porcine aortic endothelial cells (pEC) from wild-type or α1,3-galactosyltransferase gene-knockout (GTKO) pigs. In the supernatant plasma from human blood, the level of the DNA-histone complex was measured by ELISA, and thrombin generation was measured using a calibrated automated thrombogram. Histone-induced tissue factor and adhesion molecule expression were measured by flow cytometry. pEC from both wild-type and GTKO pigs significantly induced DNA-histone complex formation in human whole blood. The DNA-histone complex produced shortened the thrombin generation time and clotting time. Histone alone dose-dependently induced tissue factor and adhesion molecule expression in pEC. Aurintricarboxylic acid pretreatment partially inhibited pEC-induced DNA-histone complex formation. DNA-histone complex actively generated upon xenotransplantation is a novel target to inhibit coagulation and endothelial activation. To prevent tissue factor and adhesion molecule expression, a strategy to block soluble histone may be required in xenotransplantation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Neural mechanisms underlying sound-induced visual motion perception: An fMRI study.

PubMed

Hidaka, Souta; Higuchi, Satomi; Teramoto, Wataru; Sugita, Yoichi

2017-07-01

Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multimodal (e.g., visual and auditory) stimuli that were both in motion. Recent studies have demonstrated that sounds can trigger illusory visual apparent motion to static visual stimuli (sound-induced visual motion: SIVM): A visual stimulus blinking at a fixed location is perceived to be moving laterally when an alternating left-right sound is also present. Here, we investigated brain activity related to the perception of SIVM using a 7T functional magnetic resonance imaging technique. Specifically, we focused on the patterns of neural activities in SIVM and visually induced visual apparent motion (VIVM). We observed shared activations in the middle occipital area (V5/hMT), which is thought to be involved in visual motion processing, for SIVM and VIVM. Moreover, as compared to VIVM, SIVM resulted in greater activation in the superior temporal area and dominant functional connectivity between the V5/hMT area and the areas related to auditory and crossmodal motion processing. These findings indicate that similar but partially different neural mechanisms could be involved in auditory-induced and visually-induced motion perception, and neural signals in auditory, visual, and, crossmodal motion processing areas closely and directly interact in the perception of SIVM. Copyright © 2017 Elsevier B.V. All rights reserved.

Anxiolytic efficacy of repeated oral capsaicin in rats with partial aberration of oral sensory relay to brain.

PubMed

Choi, Young-Jun; Kim, Jin Young; Jin, Wei-Peng; Kim, Yoon-Tae; Lee, Jong-Ho; Jahng, Jeong Won

2015-07-01

This study was conducted to examine if taste over load with oral capsaicin improves the adverse behavioural effects induced by partial aberration of oral sensory relays to brain with bilateral transections of the lingual and chorda tympani nerves. Male Sprague-Dawley rats received daily 1 ml of 0.02% capsaicin or water drop by drop into the oral cavity following the bilateral transections of the lingual and chorda tympani nerves. Rats were subjected to ambulatory activity, elevated plus maze and forced swim tests after 11th, 14th and 17th daily administration of capsaicin or water, respectively. The basal and stress-induced plasma corticosterone levels were examined after the end of behavioural tests. Ambulatory counts, distance travelled, centre zone activities and rearing were increased, and rostral grooming decreased, during the activity test in capsaicin treated rats. Behavioural scores of capsaicin rats during elevated plus maze test did not differ from control rats. Immobility during the swim test was decreased in capsaicin rats with near significance (P = 0.0547). Repeated oral capsaicin increased both the basal level and stress-induced elevation of plasma corticosterone in rats with bilateral transections of the lingual and chorda tympani nerves. It is concluded that repeated oral administration of capsaicin reduces anxiety-like behaviours in rats that received bilateral transections of the lingual and chorda tympani nerves, and that the increased corticosterone response, possibly modulating the hippocampal neural plasticity, may be implicated in the anxiolytic efficacy of oral capsaicin. Copyright © 2015 Elsevier Ltd. All rights reserved.

The SIRT1 inhibitor EX-527 suppresses mTOR activation and alleviates acute lung injury in mice with endotoxiemia.

PubMed

Huang, Jing; Tian, Rui; Yang, Yongqiang; Jiang, Rong; Dai, Jie; Tang, Li; Zhang, Li

2017-11-01

It is generally regarded that Sirtuin 1 (SIRT1), a longevity factor in mammals, acts as a negative regulator of inflammation. However, recent studies also found that SIRT1 might be a detrimental factor under certain inflammatory circumstance. In this study, the potential pathophysiological roles and the underlying mechanisms of SIRT1 in a mouse model with endotoxemia-associated acute lung injury were investigated. The results indicated that treatment with the selective SIRT1 inhibitor EX-527 suppressed LPS-induced elevation of TNF-α and IL-6 in plasma. Treatment with EX-527 attenuated LPS-induced histological abnormalities in lung tissue, which was accompanied with decreased myeloperoxidase level and suppressed induction of tissue factor and plasminogen activator inhibitor-1. Treatment with EX-527 also suppressed LPS-induced phosphorylation of eukaryotic translation initiation factor-binding protein 1 (4E-BP1). Co-administration of a mammalian target of rapamycin (mTOR) activator 3-benzyl-5-[(2-nitrophenoxy) methyl]-dihydrofuran-2 (3H)-one (3BDO) abolished the inhibitory effects of EX-527 on 4E-BP1 phosphorylation. Meanwhile, the inhibitory effects of EX-527 on IL-6 induction and the beneficial effects of EX-527 on lung injury were partially reversed by 3BDO. This study suggests that selective inhibition of SIRT1 by EX-527 might alleviate endotoxemia-associated acute lung injury partially via suppression of mTOR, which implies that SIRT1 selective inhibitors might have potential value for the pharmacological intervention of inflammatory lung injury.

76 FR 63910 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-14

..., or Partially-Exclusive Licensing of an Invention Concerning a Device and Method for Inducing Brain... Application Serial No. 61/521,446, entitled ``A Device and Method for Inducing Brain Injury in Animal Test... and method for inducing brain injury in animal test subjects through inflicting pressure-wave or...

Voltage dependent potassium channel remodeling in murine intestinal smooth muscle hypertrophy induced by partial obstruction.

PubMed

Liu, Dong-Hai; Huang, Xu; Guo, Xin; Meng, Xiang-Min; Wu, Yi-Song; Lu, Hong-Li; Zhang, Chun-Mei; Kim, Young-chul; Xu, Wen-Xie

2014-01-01

Partial obstruction of the small intestine causes obvious hypertrophy of smooth muscle cells and motility disorder in the bowel proximate to the obstruction. To identify electric remodeling of hypertrophic smooth muscles in partially obstructed murine small intestine, the patch-clamp and intracellular microelectrode recording methods were used to identify the possible electric remodeling and Western blot, immunofluorescence and immunoprecipitation were utilized to examine the channel protein expression and phosphorylation level changes in this research. After 14 days of obstruction, partial obstruction caused obvious smooth muscle hypertrophy in the proximally located intestine. The slow waves of intestinal smooth muscles in the dilated region were significantly suppressed, their amplitude and frequency were reduced, whilst the resting membrane potentials were depolarized compared with normal and sham animals. The current density of voltage dependent potassium channel (KV) was significantly decreased in the hypertrophic smooth muscle cells and the voltage sensitivity of KV activation was altered. The sensitivity of KV currents (IKV) to TEA, a nonselective potassium channel blocker, increased significantly, but the sensitivity of IKv to 4-AP, a KV blocker, stays the same. The protein levels of KV4.3 and KV2.2 were up-regulated in the hypertrophic smooth muscle cell membrane. The serine and threonine phosphorylation levels of KV4.3 and KV2.2 were significantly increased in the hypertrophic smooth muscle cells. Thus this study represents the first identification of KV channel remodeling in murine small intestinal smooth muscle hypertrophy induced by partial obstruction. The enhanced phosphorylations of KV4.3 and KV2.2 may be involved in this process.

Complement system and immunological mediators: Their involvements in the induced inflammatory process by Androctonus australis hector venom and its toxic components.

PubMed

Bekkari, Nadjia; Martin-Eauclaire, Marie-France; Laraba-Djebari, Fatima

2015-01-01

Androctonus australis hector scorpion venom is well known by its high toxicity, it induces massive release of neurotransmitters that lead to pathophysiological disorders in cardiovascular, neuro-hormonal and immune systems. Previous studies have shown the relationship between the severity of scorpion envenoming and immune system activation. This study was assessed to investigate the involvement of complement system and inflammatory mediators after sublethal injection of Aah venom, its toxic fraction (FtoxG50) and its main toxins (AahI and AahII) into NMRI mice. The Activation complement system by the venom is also compared to that induced of lipopolysaccharides (LPS). Obtained results showed that seric complement system (CS) is activated by the venom and by its toxic components; this activation is more pronounced into liver tissue when toxic components (FtoxG50, AahI or AahII) are used. Increase of cytokine levels (IL1β, TNFα and ICAM) into hepatic tissue induced by AahI or AahII neurotoxins is correlated with tissue alterations. Aprotinin, a non specific inhibitor of complement system seems to be able to reduce CS consumption and to restore partially the induced tissue damage by venom. The mechanisms by which toxic fraction or LPS induced the activation of complement system seem to be different. Sensitivity of hepatic tissue is more pronounced after FtoxG50 injection; however lung tissue is more sensible to LPS than FoxG50. Copyright © 2015 Elsevier GmbH. All rights reserved.

Sucralose, an activator of the glucose-sensing receptor, increases ATP by calcium-dependent and -independent mechanisms.

PubMed

Li, Longfei; Ohtsu, Yoshiaki; Nakagawa, Yuko; Masuda, Katsuyoshi; Kojima, Itaru

2016-08-31

Sucralose is an artificial sweetener and activates the glucose-sensing receptor expressed in pancreatic β-cells. Although sucralose does not enter β-cells nor acts as a substrate for glucokinase, it induces a marked elevation of intracellular ATP ([ATP]c). The present study was conducted to identify the signaling pathway responsible for the elevation of [ATP]c induced by sucralose. Previous studies have shown that sucralose elevates cyclic AMP (cAMP), activates phospholipase C (PLC) and stimulates Ca(2+) entry by a Na(+)-dependent mechanism in MIN6 cells. The addition of forskolin induced a marked elevation of cAMP, whereas it did not affect [ATP]c. Carbachol, an activator of PLC, did not increase [ATP]c. In addition, activation of protein kinase C by dioctanoylglycerol did not affect [ATP]c. In contrast, nifedipine, an inhibitor of the voltage-dependent Ca(2+) channel, significantly reduced [ATP]c response to sucralose. Removal of extracellular Na(+) nearly completely blocked sucralose-induced elevation of [ATP]c. Stimulation of Na(+) entry by adding a Na(+) ionophore monensin elevated [ATP]c. The monensin-induced elevation of [ATP]c was only partially inhibited by nifedipine and loading of BAPTA, both of which completely abolished elevation of [Ca(2+)]c. These results suggest that Na(+) entry is critical for the sucralose-induced elevation of [ATP]c. Both calcium-dependent and -independent mechanisms are involved in the action of sucralose.

Agrin Signalling Contributes to Cell Activation and Is Overexpressed in T Lymphocytes from Lupus Patients1

PubMed Central

Jury, Elizabeth C.; Eldridge, Jillian; Isenberg, David A.; Kabouridis, Panagiotis S.

2008-01-01

It is shown in this study that the heparan sulfate proteoglycan agrin is overexpressed in T cells isolated from patients with the autoimmune disease systemic lupus erythematosus (SLE). Freshly isolated CD4+ and CD8+ subpopulations both exhibited higher expression over healthy controls, which however, gradually declined when cells were cultured in vitro. Agrin expression was induced following in vitro activation of cells via their Ag receptor, or after treatment with IFN-α, a cytokine shown to be pathogenic in lupus. Furthermore, serum from SLE patients with active disease was able to induce agrin expression when added to T cells from healthy donors, an increase that was partially blocked by neutralizing anti-IFN-α Abs. Cross-linking agrin with mAbs resulted in rapid reorganization of the actin cytoskeleton, activation of the ERK MAPK cascade, and augmentation of anti-CD3-induced proliferation and IL-10 production, indicating that agrin is a functional receptor in T cells. These results demonstrate that agrin expression in human T cells is regulated by cell activation and IFN-α, and may have an important function during cell activation with potential implications for autoimmunity. PMID:18025246

Ursolic Acid Inhibits Na+/K+-ATPase Activity and Prevents TNF-α-Induced Gene Expression by Blocking Amino Acid Transport and Cellular Protein Synthesis

PubMed Central

Yokomichi, Tomonobu; Morimoto, Kyoko; Oshima, Nana; Yamada, Yuriko; Fu, Liwei; Taketani, Shigeru; Ando, Masayoshi; Kataoka, Takao

2011-01-01

Pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, induce the expression of a wide variety of genes, including intercellular adhesion molecule-1 (ICAM-1). Ursolic acid (3β-hydroxy-urs-12-en-28-oic acid) was identified to inhibit the cell-surface ICAM-1 expression induced by pro-inflammatory cytokines in human lung carcinoma A549 cells. Ursolic acid was found to inhibit the TNF-α-induced ICAM-1 protein expression almost completely, whereas the TNF-α-induced ICAM-1 mRNA expression and NF-κB signaling pathway were decreased only partially by ursolic acid. In line with these findings, ursolic acid prevented cellular protein synthesis as well as amino acid uptake, but did not obviously affect nucleoside uptake and the subsequent DNA/RNA syntheses. This inhibitory profile of ursolic acid was similar to that of the Na+/K+-ATPase inhibitor, ouabain, but not the translation inhibitor, cycloheximide. Consistent with this notion, ursolic acid was found to inhibit the catalytic activity of Na+/K+-ATPase. Thus, our present study reveals a novel molecular mechanism in which ursolic acid inhibits Na+/K+-ATPase activity and prevents the TNF-α-induced gene expression by blocking amino acid transport and cellular protein synthesis. PMID:24970122

Modulation of CYP1A2 and CYP3A6 catalytic activities by serum from rabbits with a turpentine-induced inflammatory reaction and interleukin 6.

PubMed

Kourylko, Oksana; Fradette, Caroline; Arcand, Mathieu; du Souich, Patrick

2006-01-01

Inflammatory reactions reduce the activity of cytochrome P450 isoforms. The aim of the study was to determine the mechanisms underlying the decrease in CYP1A2 and CYP3A6 catalytic activities produced by serum from rabbits with a turpentine-induced inflammatory reaction (S(TIIR)) and interleukin 6 (IL-6). S(TIIR) and IL-6 were incubated with cultured primary hepatocytes from control rabbits (H(CONT)), and from rabbits with a turpentine-induced inflammatory reaction (H(TIIR)) in the absence or presence of pyrrolidine dithiocarbamate (PDTC), an antioxidant and inhibitor of nuclear factor kappaB transcription; 2'-amino-3'-methoxyflavone (PD98059), an inhibitor of extracellular signal-related kinase (Erk1/2); 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580), an inhibitor of p38MAPK; Nomega-nitro-L-arginine methyl ester, an inhibitor of nitric-oxide synthase 2 (NOS2); the combination of PDTC, PD98059, and SB203580; and genistein, an inhibitor of Janus-associated protein tyrosine kinase (JAK). After 4 and 24 h of incubation of H(CONT) with S(TIIR) and IL-6, CYP1A2 activity was reduced without changes in expression; the reduction in activity was partially prevented by the inhibition of JAK, Erk1/2, and NOS2. In H(CONT), S(TIIR) and IL-6 did not affect CYP3A6 activity; however, PDTC reduced CYP3A6 activity by 40 and 80% after 4 and 24 h of incubation. In H(TIIR), S(TIIR) and IL-6 reduced both CYP1A2 and CYP3A6 activities; this decrease is partially prevented by inhibitors of protein tyrosine kinases, Erk1/2, and NOS2. In H(TIIR), SB203580 increased CYP3A6 activity in a dose-dependent manner without changes in protein expression. These results show that the signal transduction pathways mediating the decrease in CYP1A2 and 3A6 activity, produced by S(TIIR) and IL-6, involve JAK, Erk1/2, and NOS2.

Metformin induces differentiation in acute promyelocytic leukemia by activating the MEK/ERK signaling pathway

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

Huai, Lei; Wang, Cuicui; Zhang, Cuiping

2012-06-08

Highlights: Black-Right-Pointing-Pointer Metformin induces differentiation in NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces activation of the MEK/ERK signaling pathway in APL cells. Black-Right-Pointing-Pointer Metformin synergizes with ATRA to trigger maturation of NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces the relocalization and degradation of the PML-RAR{alpha} fusion protein. Black-Right-Pointing-Pointer The study may be applicable for new differentiation therapy in cancer treatment. -- Abstract: Recent studies have shown that metformin, a widely used antidiabetic agent, may reduce the risk of cancer development. In this study, we investigated the antitumoral effect of metformin on both acute myeloid leukemia (AML) and acutemore » promyelocytic leukemia (APL) cells. Metformin induced apoptosis with partial differentiation in an APL cell line, NB4, but only displayed a proapoptotic effect on several non-M3 AML cell lines. Further analysis revealed that a strong synergistic effect existed between metformin and all-trans retinoic acid (ATRA) during APL cell maturation and that metformin induced the hyperphosphorylation of extracellular signal-regulated kinase (ERK) in APL cells. U0126, a specific MEK/ERK activation inhibitor, abrogated metformin-induced differentiation. Finally, we found that metformin induced the degradation of the oncoproteins PML-RAR{alpha} and c-Myc and activated caspase-3. In conclusion, these results suggest that metformin treatment may contribute to the enhancement of ATRA-induced differentiation in APL, which may deepen the understanding of APL maturation and thus provide insight for new therapy strategies.« less

Toll-like receptor 4 mediates inflammatory signaling by bacterial lipopolysaccharide in human hepatic stellate cells.

PubMed

Paik, Yong-Han; Schwabe, Robert F; Bataller, Ramón; Russo, Maria P; Jobin, Christian; Brenner, David A

2003-05-01

Bacterial lipopolysaccharide (LPS) stimulates Kupffer cells and participates in the pathogenesis of alcohol-induced liver injury. However, it is unknown whether LPS directly affects hepatic stellate cells (HSCs), the main fibrogenic cell type in the injured liver. This study characterizes LPS-induced signal transduction and proinflammatory gene expression in activated human HSCs. Culture-activated HSCs and HSCs isolated from patients with hepatitis C virus-induced cirrhosis express LPS-associated signaling molecules, including CD14, toll-like receptor (TLR) 4, and MD2. Stimulation of culture-activated HSCs with LPS results in a rapid and marked activation of NF-kappaB, as assessed by in vitro kinase assays for IkappaB kinase (IKK), IkappaBalpha steady-state levels, p65 nuclear translocation, NF-kappaB-dependent luciferase reporter gene assays, and electrophoretic mobility shift assays. Lipid A induces NF-kappaB activation in a similar manner. Both LPS- and lipid A-induced NF-kappaB activation is blocked by preincubation with either anti-TLR4 blocking antibody (HTA125) or Polymyxin B. Lipid A induces NF-kappaB activation in HSCs from TLR4-sufficient (C3H/OuJ) mice but not from TLR4-deficient (C3H/HeJ) mice. LPS also activates c-Jun N-terminal kinase (JNK), as assessed by in vitro kinase assays. LPS up-regulates IL-8 and MCP-1 gene expression and secretion. LPS-induced IL-8 secretion is completely inhibited by the IkappaB super repressor (Ad5IkappaB) and partially inhibited by a specific JNK inhibitor, SP600125. LPS also up-regulates cell surface expression of ICAM-1 and VCAM-1. In conclusion, human activated HSCs utilize components of TLR4 signal transduction cascade to stimulate NF-kappaB and JNK and up-regulate chemokines and adhesion molecules. Thus, HSCs are a potential mediator of LPS-induced liver injury.

The effect of magnolol on Ca2+ homeostasis and its related physiology in human oral cancer cells.

PubMed

Hsieh, Shu-Feng; Chou, Chiang-Ting; Liang, Wei-Zhe; Kuo, Chun-Chi; Wang, Jue-Long; Hao, Lyh-Jyh; Jan, Chung-Ren

2018-05-01

Magnolol, a polyphenol compound from herbal medicines, was shown to alter physiology in various cell models. However, the effect of magnolol on Ca 2+ homeostasis and its related physiology in oral cancer cells is unclear. This study examined whether magnolol altered Ca 2+ signaling and cell viability in OC2 human oral cancer cells. Cytosolic Ca 2+ concentrations ([Ca 2+ ] i ) in suspended cells were measured by using the fluorescent Ca 2+ -sensitive dye fura-2. Cell viability was examined by 4-[3-[4-lodophenyl]-2-4(4-nitrophenyl)-2H-5-tetrazolio-1,3-benzene disulfonate] water soluble tetrazolium-1 (WST-1) assay. Magnolol at concentrations of 20-100 μM induced [Ca 2+ ] i rises. Ca 2+ removal reduced the signal by approximately 50%. Magnolol (100 μM) induced Mn 2+ influx suggesting of Ca 2+ entry. Magnolol-induced Ca 2+ entry was partially suppressed by protein kinase C (PKC) regulators, and inhibitors of store-operated Ca 2+ channels. In Ca 2+ -free medium, treatment with the endoplasmic reticulum Ca 2+ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) abolished magnolol-evoked [Ca 2+ ] i rises. Conversely, treatment with magnolol abolished BHQ-evoked [Ca 2+ ] i rises. Inhibition of phospholipase C (PLC) with U73122 partially inhibited magnolol-induced [Ca 2+ ] i rises. Magnolol at 20-100 μM decreased cell viability, which was not reversed by pretreatment with the Ca 2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Together, in OC2 cells, magnolol induced [Ca 2+ ] i rises by evoking partially PLC-dependent Ca 2+ release from the endoplasmic reticulum and Ca 2+ entry via PKC-sensitive store-operated Ca 2+ entry. Magnolol also caused Ca 2+ -independent cell death. Therefore, magnolol-induced cytotoxicity may not be involved in activation mechanisms associated with intracellular Ca 2+ mobilization in oral cancer cells. Copyright © 2018. Published by Elsevier Ltd.

Airways and vascular smooth muscles relaxant activities of Gaultheria trichophylla.

PubMed

Alam, Fiaz; Saqib, Qazi Najumus; Shah, Abdul Jabbar

2017-01-01

The aim of this experimental work was to explore the potential pharmacological activities of Gaultheria trichophylla Royle in hyperactive respiratory and vascular conditions. Gaultheria trichophylla was extracted with solvents, phytochemical detection tests were performed, and rabbit trachea and aorta strips were used to evaluate its effects on airways and vascular smooth muscles. Qualitative phytochemical tests showed the presence of flavonoids, alkaloids, anthraquinones, saponins, terpenoids, and condensed tannins. The methanol extract caused inhibition (EC 50 values of 3.12 mg/mL) of carbachol (1 μM) and partial relaxation of K + (80 mM) caused contractions in tracheal strips. The chloroform extract was comparatively more potent against carbachol than K+ induced contraction with EC 50 values of 0.64 and 2.26 mg/mL, respectively. However, the n-hexane extract showed more potency against K + than cabachol induced contractions, as in case with verapamil, with EC 50 values of 0.61 and 6.58 mg/mL, respectively. In isolated prepared trachea, the extracts displaced the carbachol concentration response curves and maximum response was suppressed. In rabbit aorta preparations, methanol and n-hexane extracts partially relaxed phenylephrine (1 μM) and K + induced vasoconstrictions. However, the chloroform extract inhibited phenylephrine induced contractions and exhibited a vasoconstrictor effect at lower concentrations and a relaxant effect at higher concentrations against K + precontractions. The data indicates that, in addition to others, the extracts of G .trichophylla possess verapamil like Ca ++ channel blocking components which explain the possible role of this plant in respiratory and vascular conditions.

β-Glucan Reverses the Epigenetic State of LPS-Induced Immunological Tolerance

PubMed Central

Novakovic, Boris; Habibi, Ehsan; Wang, Shuang-Yin; Arts, Rob J.W.; Davar, Robab; Megchelenbrink, Wout; Kim, Bowon; Kuznetsova, Tatyana; Kox, Matthijs; Zwaag, Jelle; Matarese, Filomena; van Heeringen, Simon J.; Janssen-Megens, Eva M.; Sharifi, Nilofar; Wang, Cheng; Keramati, Farid; Schoonenberg, Vivien; Flicek, Paul; Clarke, Laura; Pickkers, Peter; Heath, Simon; Gut, Ivo; Netea, Mihai G.; Martens, Joost H.A.; Logie, Colin; Stunnenberg, Hendrik G.

2018-01-01

Summary Innate immune memory is the phenomenon whereby innate immune cells such as monocytes or macrophages undergo functional reprogramming after exposure to microbial components such as lipopolysaccharide (LPS). We apply an integrated epigenomic approach to characterize the molecular events involved in LPS-induced tolerance in a time-dependent manner. Mechanistically, LPS-treated monocytes fail to accumulate active histone marks at promoter and enhancers of genes in the lipid metabolism and phagocytic pathways. Transcriptional inactivity in response to a second LPS exposure in tolerized macrophages is accompanied by failure to deposit active histone marks at promoters of tolerized genes. In contrast, β-glucan partially reverses the LPS-induced tolerance in vitro. Importantly, ex vivo β-glucan treatment of monocytes from volunteers with experimental endotoxemia re-instates their capacity for cytokine production. Tolerance is reversed at the level of distal element histone modification and transcriptional reactivation of otherwise unresponsive genes. PMID:27863248

E-p-Methoxycinnamic acid protects cultured neuronal cells against neurotoxicity induced by glutamate

PubMed Central

Kim, So Ra; Sung, Sang Hyun; Jang, Young Pyo; Markelonis, George J; Oh, Tae H; Kim, Young Choong

2002-01-01

We previously reported that four new phenylpropanoid glycosides and six known cinnamate derivatives isolated from roots of Scrophularia buergeriana Miquel (Scrophulariaceae) protected cultured cortical neurons from neurotoxicity induced by glutamate. Here, we have investigated the structure-activity relationships in the phenylpropanoids using our primary culture system. The α,β-unsaturated ester moiety and the para-methoxy group in the phenylpropanoids appeared to play a vital role in neuroprotective activity. This suggested that E-p-methoxycinnamic acid (E-p-MCA) might be a crucial component for their neuroprotective activity within the phenylpropanoid compounds. E-p-MCA significantly attenuated glutamate-induced neurotoxicity when added prior to an excitotoxic glutamate challenge. The neuroprotective activity of E-p-MCA appeared to be more effective in protecting neurons against neurotoxicity induced by NMDA than from that induced by kainic acid. E-p-MCA inhibited the binding of [propyl-2,3-3H]-CGP39653 and [2-3H]-glycine to their respective binding sites on rat cortical membranes. However, even high concentrations of E-p-MCA failed to inhibit completely [propyl-2,3-3H]-CGP39653 and [2-3H]-glycine binding. Indeed, E-p-MCA diminished the calcium influx that routinely accompanies glutamate-induced neurotoxicity, and inhibited the subsequent overproduction of nitric oxide and cellular peroxide in glutamate-injured neurons. Thus, our results suggest that E-p-MCA exerts significant protective effects against neurodegeneration induced by glutamate in primary cultures of cortical neurons by an action suggestive of partial glutamatergic antagonism. PMID:11877337

Ginsenoside Rb1 protects against 6-hydroxydopamine-induced oxidative stress by increasing heme oxygenase-1 expression through an estrogen receptor-related PI3K/Akt/Nrf2-dependent pathway in human dopaminergic cells

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

Hwang, Yong Pil; College of Pharmacy, Chosun University, Gwangju; Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.k

Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. Ginseng, the root of Panax ginseng C.A. Meyer (Araliaceae), is a popular traditional herbal medicine. Ginsenoside Rb1 (Rb1), an active component commonly found in ginseng root, is a phytoestrogen that exerts estrogen-like activity. In this study, we demonstrate that the phytoestrogen Rb1 inhibits 6-hydroxydopamine (6-OHDA)-induced oxidative injury via an ER-dependent Gbeta1/PI3K/Akt and heme oxygenase-1 (HO-1) pathway. Pretreatment of SH-SY5Y cells with Rb1 significantly reduced 6-OHDA-induced caspase-3 activation and subsequent cell death. Rb1 also up-regulated HO-1 expression, which conferred cytoprotection against 6-OHDA-induced oxidative injury. Moreover, Rb1 induced both Nrf2 nuclear translocation,more » which is upstream of HO-1 expression and PI3K activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. Also, Rb1-mediated increases in PI3K activation and HO-1 induction were reversed by co-treatment with ICI 182,780 and pertussis toxin. Taken together, these results suggest that Rb1 augments the cellular antioxidant defenses through ER-dependent HO-1 induction via the Gbeta1/PI3K/Akt-Nrf2 signaling pathway, thereby protecting cells from oxidative stress. Thus our study indicates that Rb1 has a partial cytoprotective role in dopaminergic cell culture systems.« less

Dok5 is involved in the signaling pathway of neurotrophin-3 against TrkC-induced apoptosis.

PubMed

Pan, Yanfang; Zhang, Jing; Liu, Wei; Shu, Pengcheng; Yin, Bin; Yuan, Jiangang; Qiang, Boqin; Peng, Xiaozhong

2013-10-11

TrkC is a dependence receptor and many reports have shown that neurotrophin-3 promotes cell survival by inhibiting TrkC-induced apoptosis in many cell lines. However, the identity of the adaptor protein involved in the NT-3/TrkC signaling pathway regulating cell death and survival remains unclear. The downstream of tyrosine kinase/docking protein (Dok) adaptor protein 5 is one substrate of the TrkC receptor. Because NT-3 and its receptor, TrkC, are strongly expressed by sensory neurons, we measured the expression of Dok5 and TrkC in the developing mouse spinal cord and dorsal root ganglia (DRG). We found that the number of cells positive for both Dok5 and TrkC decreases with DRG development. Immunoprecipitation and immunofluorescence staining showed that Dok5 interacted with TrkC and partially colocalized with TrkC in DRG neurons. In HEK293T cells, TrkC triggered apoptosis, but NT-3 prevented TrkC-induced apoptosis. Interestingly, siRNA knockdown of Dok5 expression partially prevented the protection of NT-3 against TrkC-induced apoptosis by regulating the activity of caspase-3. Taken together, we concluded that Dok5 is necessary for NT-3 signaling to block TrkC-induced apoptosis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Apolipoprotein CIII-induced THP-1 cell adhesion to endothelial cells involves pertussis toxin-sensitive G protein- and protein kinase C alpha-mediated nuclear factor-kappaB activation.

PubMed

Kawakami, Akio; Aikawa, Masanori; Nitta, Noriko; Yoshida, Masayuki; Libby, Peter; Sacks, Frank M

2007-01-01

Plasma apolipoprotein CIII (apoCIII) independently predicts risk for coronary heart disease (CHD). We recently reported that apoCIII directly enhances adhesion of human monocytes to endothelial cells (ECs), and identified the activation of PKC alpha as a necessary upstream event of enhanced monocyte adhesion. This study tested the hypothesis that apoCIII activates PKC alpha in human monocytic THP-1 cells, leading to NF-kappaB activation. Among inhibitors specific to PKC activators, phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor D609 limited apoCIII-induced PKC alpha activation and THP-1 cell adhesion. ApoCIII increased PC-PLC activity in THP-1 cells, resulting in PKC alpha activation. Pertussis toxin (PTX) inhibited apoCIII-induced PC-PLC activation and subsequent PKC alpha activation, implicating PTX-sensitive G protein pathway. ApoCIII further activated nuclear factor-kappaB (NF-kappaB) through PKC alpha in THP-1 cells and augmented beta1-integrin expression. The NF-kappaB inhibitor peptide SN50 partially inhibited apoCIII-induced beta1-integrin expression and THP-1 cell adhesion. ApoCIII-rich VLDL had similar effects to apoCIII alone. PTX-sensitive G protein pathway participates critically in PKC alpha stimulation in THP-1 cells exposed to apoCIII, activating NF-kappaB, and increasing beta1-integrin. This action causes monocytic cells to adhere to endothelial cells. Furthermore, because leukocyte NF-kappaB activation contributes to inflammatory aspects of atherogenesis, apoCIII may stimulate diverse inflammatory responses through monocyte activation.

The necroptosis adaptor RIPK3 promotes injury-induced cytokine expression and tissue repair.

PubMed

Moriwaki, Kenta; Balaji, Sakthi; McQuade, Thomas; Malhotra, Nidhi; Kang, Joonsoo; Chan, Francis Ka-Ming

2014-10-16

Programmed necrosis or necroptosis is an inflammatory form of cell death that critically requires the receptor-interacting protein kinase 3 (RIPK3). Here we showed that RIPK3 controls a separate, necrosis-independent pathway of inflammation by regulating cytokine expression in dendritic cells (DCs). Ripk3(-/-) bone-marrow-derived dendritic cells (BMDCs) were highly defective in lipopolysaccharide (LPS)-induced expression of inflammatory cytokines. These effects were caused by impaired NF-κB subunit RelB and p50 activation and by impaired caspase 1-mediated processing of interleukin-1β (IL-1β). This DC-specific function of RIPK3 was critical for injury-induced inflammation and tissue repair in response to dextran sodium sulfate (DSS). Ripk3(-/-) mice exhibited an impaired axis of injury-induced IL-1β, IL-23, and IL-22 cytokine cascade, which was partially corrected by adoptive transfer of wild-type DCs, but not Ripk3(-/-) DCs. These results reveal an unexpected function of RIPK3 in NF-κB activation, DC biology, innate inflammatory-cytokine expression, and injury-induced tissue repair.

Grain dust-induced lung inflammation is reduced by Rhodobacter sphaeroides diphosphoryl lipid A.

PubMed

Jagielo, P J; Quinn, T J; Qureshi, N; Schwartz, D A

1998-01-01

To further determine the importance of endotoxin in grain dust-induced inflammation of the lower respiratory tract, we evaluated the efficacy of pentaacylated diphosphoryl lipid A derived from the lipopolysaccharide of Rhodobacter sphaeroides (RsDPLA) as a partial agonist of grain dust-induced airway inflammation. RsDPLA is a relatively inactive compound compared with lipid A derived from Escherichia coli (LPS) and has been demonstrated to act as a partial agonist of LPS-induced inflammation. To assess the potential stimulatory effect of RsDPLA in relation to LPS, we incubated THP-1 cells with RsDPLA (0.001-100 micrograms/ml), LPS (0.02 microgram endotoxin activity/ml), or corn dust extract (CDE; 0.02 microgram endotoxin activity/ml). Incubation with RsDPLA revealed a tumor necrosis factor (TNF)-alpha stimulatory effect at 100 micrograms/ml. In contrast, incubation with LPS or CDE resulted in TNF-alpha release at 0.02 microgram/ml. Pretreatment of THP-1 cells with varying concentrations of RsDPLA before incubation with LPS or CDE (0.02 microgram endotoxin activity/ml) resulted in a dose-dependent reduction in the LPS- or CDE-induced release of TNF-alpha with concentrations of RsDPLA of up to 10 micrograms/ml but not at 100 micrograms/ml. To further understand the role of endotoxin in grain dust-induced airway inflammation, we utilized the unique LPS inhibitory property of RsDPLA to determine the inflammatory response to inhaled CDE in mice in the presence of RsDPLA. Ten micrograms of RsDPLA intratracheally did not cause a significant inflammatory response compared with intratracheal saline. However, pretreatment of mice with 10 micrograms of RsDPLA intratracheally before exposure to CDE (5.4 and 0.2 micrograms/m3) or LPS (7.2 and 0.28 micrograms/m3) resulted in significant reductions in the lung lavage concentrations of total cells, neutrophils, and specific proinflammatory cytokines compared with mice pretreated with sterile saline. These results confirm the LPS-inhibitory effect of RsDPLA and support the role of endotoxin as the principal agent in grain dust causing airway inflammation.

Activity-induced regulation of myosin isoform distribution - Comparison of two contractile activity programs

NASA Technical Reports Server (NTRS)

Diffee, Gary M.; Caiozzo, Vince J.; Mccue, Samuel A.; Herrick, Robert E.; Baldwin, Kenneth M.

1993-01-01

This study examined the role of specific types of contractile activity in regulating myosin heavy chain (MHC) isoform expression in rodent soleus. A combination of hindlimb suspension (SN) and two programmed contractile training activity paradigms, either isometric contractile activity (ST-IM) or high-load slowly shortening isovelocity activity, were utilized. Both training paradigms increased muscle mass compared with SN alone. However, only ST-IM resulted in a partial prevention of the suspension-induced decrease in type I MHC. With the use of a fluorescently labeled antibody to type IIa MHC, the distribution of MHCs among fibers was examined immunohistochemically. In SN, the percentage of cells staining positive for type IIa MHC was increased but the staining intensity of the positively staining cells was unchanged compared with control cells. In the ST-IM soleus, the percentage of positively staining fibers was unchanged but the intensity of the positively staining cells was decreased compared with SN values. These results suggest that 1) isometric contractile activity is more effective than isovelocity activity in preventing suspension-induced shifts in soleus MHC distribution and 2) changes associated with both suspension and training occur in only a small number of fibers, with the majority of fibers apparently unresponsive to these interventions.

5-Hydroxy-3,6,7,8,3'4'-hexamethoxyflavone inhibits nitric oxide production in lipopolysaccharide-stimulated BV2 microglia via NF-κB suppression and Nrf-2-dependent heme oxygenase-1 induction.

PubMed

Kang, Chang-Hee; Kim, Min Jeong; Seo, Min Jeong; Choi, Yung Hyun; Jo, Wol Soon; Lee, Kyung-Tae; Jeong, Yong Kee; Kim, Gi-Young

2013-07-01

In this study, we found that 5-hydroxy-3,6,7,8,3'4'-hexamethoxyflavone (5HHMF) from Hizikia fusiforme considerably inhibits lipopolysaccharide (LPS)-stimulated NO production by suppressing the expression of inducible NO synthase (iNOS) in BV2 microglia. In addition, 5HHMF blocked LPS-induced phosphorylation of IκB, resulting in suppression of the nuclear translocation of nuclear factor-κB (NF-κB) subunits, namely p65 and p50, which are important molecules involved in the regulation of iNOS expression. Pyrrolidine dithiocarbamate (PDTC), a specific NF-κB inhibitor, along with 20S proteasome inhibitor (PSI) significantly inhibited LPS-induced iNOS expression, which indirectly suggested that 5HHMF downregulated iNOS expression by suppressing NF-κB activity. Thus, we found that 5HHMF enhances heme oxygenase-1 (HO-1) expression via nuclear factor-erythroid 2-related factor 2 (Nrf2) activation. In addition, cobalt protoporphyrin (CoPP), a specific HO-1 inducer, predominantly suppressed LPS-induced NO production. In contrast, zinc protoporphyrin (ZnPP), a specific HO-1 inhibitor, showed a partial suppressive effect of 5HHMF on LPS-induced NO production. Further, 5HHMF increased specific DNA-binding activity of Nrf2, and transient knockdown with Nrf2 siRNA subsequently reversed 5HHMF-induced NO inhibition, which was followed by suppression of HO-1 activity. Taken together, our findings indicate that 5HHMF suppresses NO production through modulation of iNOS, consequently suppressing NF-κB activity and induction of Nrf2-dependent HO-1 activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of mosapride citrate, a 5-HT4-receptor agonist, on gastric distension-induced visceromotor response in conscious rats.

PubMed

Seto, Yasuhiro; Yoshida, Naoyuki; Kaneko, Hiroshi

2011-01-01

Mosapride citrate (mosapride), a prokinetic agent with 5-HT(4)-receptor agonistic activity, is known to enhance gastric emptying and alleviate symptoms in patients with functional dyspepsia (FD). As hyperalgesia and delayed gastric emptying play an important role in the pathogenesis of FD, we used in this study balloon gastric distension to enable abdominal muscle contractions and characterized the visceromotor response (VMR) to such distension in conscious rats. We also investigated the effects of mosapride on gastric distension-induced VMR in the same model. Mosapride (3-10 mg/kg, p.o.) dose-dependently inhibited gastric distension-induced VMR in rats. However, itopride even at 100 mg/kg failed to inhibit gastric distension-induced VMR in rats. Additionally, a major metabolite M1 of mosapride, which possesses 5-HT(3)-receptor antagonistic activity, inhibited gastric distension-induced VMR. The inhibitory effect of mosapride on gastric distension-induced visceral pain was partially, but significantly inhibited by SB-207266, a selective 5-HT(4)-receptor antagonist. This study shows that mosapride inhibits gastric distension-induced VMR in conscious rats. The inhibitory effect of mosapride is mediated via activation of 5-HT(4) receptors and blockage of 5-HT(3) receptors by a mosapride metabolite. This finding indicates that mosapride may be useful in alleviating FD-associated gastrointestinal symptoms via increase in pain threshold.

5-HT1A receptor-dependent modulation of emotional and neurogenic deficits elicited by prolonged consumption of alcohol.

PubMed

Belmer, Arnauld; Patkar, Omkar L; Lanoue, Vanessa; Bartlett, Selena E

2018-02-01

Repeated episodes of binge-like alcohol consumption produce anxiety, depression and various deleterious effects including alterations in neurogenesis. While the involvement of the serotonin receptor 1 A (5-HT 1A ) in the regulation of anxiety-like behavior and neurogenesis is well documented, its contribution to alcohol withdrawal-induced anxiety and alcohol-induced deficits in neurogenesis is less documented. Using the Drinking-In-the-Dark (DID) paradigm to model chronic long-term (12 weeks) binge-like voluntary alcohol consumption in mice, we show that the selective partial activation of 5-HT 1A receptors by tandospirone (3 mg/kg) prevents alcohol withdrawal-induced anxiety in a battery of behavioral tests (marble burying, elevated-plus-maze, open-field), which is accompanied by a robust decrease in binge-like ethanol intake (1 and 3 mg/kg). Furthermore, using triple immunolabelling of proliferation and neuronal differentiation markers, we show that long-term DID elicits profound deficits in neurogenesis and neuronal fate specification in the dorsal hippocampus that are entirely reversed by a 2-week chronic treatment with the 5-HT 1A partial agonist tandospirone (3 mg/kg/day). Together, our results confirm previous observations that 5-HT 1A receptors play a pivotal role in alcohol drinking behavior and the associated emotional and neurogenic impairments, and suggest that 5-HT 1A partial agonists represent a promising treatment strategy for alcohol abuse.

Partial genetic deletion of neuregulin 1 modulates the effects of stress on sensorimotor gating, dendritic morphology, and HPA axis activity in adolescent mice.

PubMed

Chohan, Tariq W; Boucher, Aurelie A; Spencer, Jarrah R; Kassem, Mustafa S; Hamdi, Areeg A; Karl, Tim; Fok, Sandra Y; Bennett, Maxwell R; Arnold, Jonathon C

2014-11-01

Stress has been linked to the pathogenesis of schizophrenia. Genetic variation in neuregulin 1 (NRG1) increases the risk of developing schizophrenia and may help predict which high-risk individuals will transition to psychosis. NRG1 also modulates sensorimotor gating, a schizophrenia endophenotype. We used an animal model to demonstrate that partial genetic deletion of Nrg1 interacts with stress to promote neurobehavioral deficits of relevance to schizophrenia. Nrg1 heterozygous (HET) mice displayed greater acute stress-induced anxiety-related behavior than wild-type (WT) mice. Repeated stress in adolescence disrupted the normal development of higher prepulse inhibition of startle selectively in Nrg1 HET mice but not in WT mice. Further, repeated stress increased dendritic spine density in pyramidal neurons of the medial prefrontal cortex (mPFC) selectively in Nrg1 HET mice. Partial genetic deletion of Nrg1 also modulated the adaptive response of the hypothalamic-pituitary-adrenal axis to repeated stress, with Nrg1 HET displaying a reduced repeated stress-induced level of plasma corticosterone than WT mice. Our results demonstrate that Nrg1 confers vulnerability to repeated stress-induced sensorimotor gating deficits, dendritic spine growth in the mPFC, and an abberant endocrine response in adolescence. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Validity of hip-mounted uniaxial accelerometry with heart-rate monitoring vs. triaxial accelerometry in the assessment of free-living energy expenditure in young children: the IDEFICS Validation Study.

PubMed

Ojiambo, Robert; Konstabel, Kenn; Veidebaum, Toomas; Reilly, John; Verbestel, Vera; Huybrechts, Inge; Sioen, Isabelle; Casajús, José A; Moreno, Luis A; Vicente-Rodriguez, German; Bammann, Karin; Tubic, Bojan M; Marild, Staffan; Westerterp, Klaas; Pitsiladis, Yannis P

2012-11-01

One of the aims of Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants (IDEFICS) validation study is to validate field measures of physical activity (PA) and energy expenditure (EE) in young children. This study compared the validity of uniaxial accelerometry with heart-rate (HR) monitoring vs. triaxial accelerometry against doubly labeled water (DLW) criterion method for assessment of free-living EE in young children. Forty-nine European children (25 female, 24 male) aged 4-10 yr (mean age: 6.9 ± 1.5 yr) were assessed by uniaxial ActiTrainer with HR, uniaxial 3DNX, and triaxial 3DNX accelerometry. Total energy expenditure (TEE) was estimated using DLW over a 1-wk period. The longitudinal axis of both devices and triaxial 3DNX counts per minute (CPM) were significantly (P < 0.05) associated with physical activity level (PAL; r = 0.51 ActiTrainer, r = 0.49 uniaxial-3DNX, and r = 0.42 triaxial Σ3DNX). Eight-six percent of the variance in TEE could be predicted by a model combining body mass (partial r(2) = 71%; P < 0.05), CPM-ActiTrainer (partial r(2) = 11%; P < 0.05), and difference between HR at moderate and sedentary activities (ModHR - SedHR) (partial r(2) = 4%; P < 0.05). The SE of TEE estimate for ActiTrainer and 3DNX models ranged from 0.44 to 0.74 MJ/days or ∼7-11% of the average TEE. The SE of activity-induced energy expenditure (AEE) model estimates ranged from 0.38 to 0.57 MJ/day or 24-26% of the average AEE. It is concluded that the comparative validity of hip-mounted uniaxial and triaxial accelerometers for assessing PA and EE is similar.

Antitumor activity of a novel and orally available inhibitor of serine palmitoyltransferase

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

Yaguchi, Masahiro; Shibata, Sachio; Satomi, Yoshinori

Metabolic reprogramming is an essential hallmark of neoplasia. Therefore, targeting cancer metabolism, including lipid synthesis, has attracted much interest in recent years. Serine palmitoyltransferase (SPT) plays a key role in the initial and rate-limiting step of de novo sphingolipid biosynthesis, and inhibiting SPT activity prevents the proliferation of certain cancer cells. Here, we identified a novel and orally available SPT inhibitor, compound-2. Compound-2 showed an anti-proliferative effect in several cancer cell models, reducing the levels of the sphingolipids ceramide and sphingomyelin. In the presence of compound-2, exogenously added S1P partially compensated the intracellular sphingolipid levels through the salvage pathway bymore » partially rescuing compound-2-induced cytotoxicity. This suggested that the mechanism underlying the anti-proliferative effect of compound-2 involved the reduction of sphingolipid levels. Indeed, compound-2 promoted multinuclear formation with reduced endogenous sphingomyelin levels specifically in a compound-2-sensitive cell line, indicating that the effect was induced by sphingolipid reduction. Furthermore, compound-2 showed potent antitumor activity without causing significant body weight loss in the PL-21 acute myeloid leukemia mouse xenograft model. Therefore, SPT may be an attractive therapeutic anti-cancer drug target for which compound-2 may be a promising new drug. - Highlights: • We discovered compound-2, a novel and orally available SPT inhibitor. • Compound-2 was cytotoxic against PL-21 acute myeloid leukemia cells. • Compound-2 showed antitumor activity in the PL-21 mouse xenograft model.« less

Altered cerebral activity associated with topiramate and its withdrawal in patients with epilepsy with language impairment: An fMRI study using the verb generation task.

PubMed

Tang, Yingying; Xia, Wei; Yu, Xiaofeng; Zhou, Bo; Wu, Xintong; Lui, Su; Luo, Chunyan; Huang, Xiaoqi; Ouyang, Luo; Chen, Qin; Gong, Qiyong; Zhou, Dong

2016-06-01

Topiramate (TPM) is well recognized for its negative effects on language in healthy volunteers and patients with epilepsy. The aim of this study was to investigate the brain activation and deactivation patterns in TPM-treated patients with epilepsy with language impairment and their dynamic alteration during TPM withdrawal using functional magnetic resonance imaging (fMRI) with the verb generation task (VGT). Twelve patients with epilepsy experiencing subjective language disfluency after TPM add-on treatment (TPM-on) and thirty sex- and age-matched healthy controls (HCs) were recruited. All subjects received a battery of neuropsychological tests and an fMRI scan with the VGT. Withdrawal of TPM was attempted in all patients. Only six patients reached complete withdrawal without seizure relapses (TPM-off), and these patients underwent a reassessment of neuropsychological and neuroimaging tests. The neuropsychological tests demonstrated objective language impairments in TPM-on patients. Compared with the HCs, the bilateral medial prefrontal cortex and the posterior midline and lateral parts of the default mode network (DMN) (including the bilateral posterior cingulate cortex (PCC), the right medial prefrontal cortex, the right angular gyrus, the right inferior temporal gyrus, and the bilateral supramarginal gyrus) in TPM-on patients failed to deactivate during the VGT. Their task-induced activation patterns were largely similar to those of the HCs. After TPM withdrawal, partial improvement of both task-induced deactivation of the DMN (the left parahippocampal gyrus and the bilateral PCC) and task-related activation of the language network (the right middle frontal gyrus and the left superior occipital gyrus) was identified along with partial improvement of neuropsychological tests. Task-induced deactivation is a more sensitive neuroimaging biomarker for the impaired language performance in patients administered TPM than task-induced activation. Disruption and reorganization of the balance between the DMN and the cortical language networks are found along with reversible TPM-related language impairment. These results may suggest an underlying brain mechanism by which TPM affects cognitive function. Copyright © 2016 Elsevier Inc. All rights reserved.

Modulation of hepatic inflammation and energy-sensing pathways in the rat liver by high-fructose diet and chronic stress.

PubMed

Veličković, Nataša; Teofilović, Ana; Ilić, Dragana; Djordjevic, Ana; Vojnović Milutinović, Danijela; Petrović, Snježana; Preitner, Frederic; Tappy, Luc; Matić, Gordana

2018-05-29

High-fructose consumption and chronic stress are both associated with metabolic inflammation and insulin resistance. Recently, disturbed activity of energy sensor AMP-activated protein kinase (AMPK) was recognized as mediator between nutrient-induced stress and inflammation. Thus, we analyzed the effects of high-fructose diet, alone or in combination with chronic stress, on glucose homeostasis, inflammation and expression of energy sensing proteins in the rat liver. In male Wistar rats exposed to 9-week 20% fructose diet and/or 4-week chronic unpredictable stress we measured plasma and hepatic corticosterone level, indicators of glucose homeostasis and lipid metabolism, hepatic inflammation (pro- and anti-inflammatory cytokine levels, Toll-like receptor 4, NLRP3, activation of NFκB, JNK and ERK pathways) and levels of energy-sensing proteins AMPK, SIRT1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). High-fructose diet led to glucose intolerance, activation of NFκB and JNK pathways and increased intrahepatic IL-1β, TNFα and inhibitory phosphorylation of insulin receptor substrate 1 on Ser 307 . It also decreased phospho-AMPK/AMPK ratio and increased SIRT1 expression. Stress alone increased plasma and hepatic corticosterone but did not influence glucose tolerance, nor hepatic inflammatory or energy-sensing proteins. After the combined treatment, hepatic corticosterone was increased, glucose tolerance remained preserved, while hepatic inflammation was partially prevented despite decreased AMPK activity. High-fructose diet resulted in glucose intolerance, hepatic inflammation, decreased AMPK activity and reduced insulin sensitivity. Chronic stress alone did not exert such effects, but when applied together with high-fructose diet it could partially prevent fructose-induced inflammation, presumably due to increased hepatic glucocorticoids.

Paroxetine-induced apoptosis in human osteosarcoma cells: Activation of p38 MAP kinase and caspase-3 pathways without involvement of [Ca{sup 2+}]{sub i} elevation

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

Chou, C.-T.; Department of Biological Sciences, National Sun Yat-sen University, 804, Taiwan; He Shiping

2007-02-01

Selective serotonin reuptake inhibitors (SSRIs), a group of antidepressants, are generally used for treatment of various mood and anxiety disorders. There has been much research showing the anti-tumor and cytotoxic activities of some antidepressants; but the detailed mechanisms were unclear. In cultured human osteosarcoma cells (MG63), paroxetine reduced cell viability in a concentration- and time-dependent manner. Paroxetine caused apoptosis as assessed by propidium iodide-stained cells and increased caspase-3 activation. Although immunoblotting data revealed that paroxetine could activate the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun NH{sub 2}-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK), only SB203580 (a p38more » MAPK inhibitor) partially prevented cells from apoptosis. Paroxetine also induced [Ca{sup 2+}]{sub i} increases which involved the mobilization of intracellular Ca{sup 2+} stored in the endoplasmic reticulum and Ca{sup 2+} influx from extracellular medium. However, pretreatment with BAPTA/AM, a Ca{sup 2+} chelator, to prevent paroxetine-induced [Ca{sup 2+}]{sub i} increases did not protect cells from death. The results suggest that in MG63 cells, paroxetine caused Ca{sup 2+}-independent apoptosis via inducing p38 MAPK-associated caspase-3 activation.« less

Modulation of paraquat toxicity by beta-carotene at low oxygen partial pressure in chicken embryo fibroblasts.

PubMed

Lawlor, S M; O'Brien, N M

1997-01-01

The efficiency with which beta-carotene protects against oxidative stress in chicken embryo fibroblasts (CEF) at low O2 partial pressures was assessed. Primary cultures of CEF were grown at low O2 partial pressures and oxidatively stressed by exposure to paraquat (PQ). Activities of the antioxidant enzymes superoxide dismutase (EC 1.15.1.1; SOD), catalase (EC 1.11.1.6; CAT) and glutathione peroxidase (EC 1.11.1.9; GSH-Px) were measured as indices of oxidative stress. CEF incubated with 0.25-1.0 mM-PQ for 18 h exhibited increased SOD and CAT activities compared with non-PQ-treated control cells (P < 0.001). No cytotoxicity as indicated by lactate dehydrogenase (EC 1.1.1.27; LDH) release was observed at PQ concentrations below 2.0 mM. Incorporation of added beta-carotene into 0.25 mM-PQ-treated cells prevented the PQ-induced increases in SOD and CAT, and activities were similar to those seen in non-PQ-treated control cells. GSH-Px activity decreased relative to its control value on exposure to 0.25 mM-PQ and beta-carotene prevented this decrease in a dose-dependent manner. The proportion of LDH released from the CEF treated with beta-carotene remained below the control value of 2.5% at all times.

STATs MEDIATE FIBROBLAST GROWTH FACTOR INDUCED VASCULAR ENDOTHELIAL MORPHOGENESIS

PubMed Central

Yang, Xinhai; Qiao, Dianhua; Meyer, Kristy; Friedl, Andreas

2009-01-01

The fibroblast growth factors (FGFs) play diverse roles in development, wound healing and angiogenesis. The intracellular signal transduction pathways which mediate these pleiotropic activities remain incompletely understood. We show here that the proangiogenic factors FGF2 and FGF8b can activate signal transducers and activators of transcription (STATs) in mouse microvascular endothelial cells. Both FGF2 and FGF8b activate STAT5 and to a lesser extent STAT1, but not STAT3. The FGF2-dependent activation of endothelial STAT5 was confirmed in vivo with the matrigel plug angiogenesis assay. In tissue samples of human gliomas, a tumor type where FGF-induced angiogenesis is important, STAT5 is detected in tumor vessel endothelial cell nuclei, consistent with STAT5 activation. By forced expression of constitutively active or dominant-negative mutant STAT5A in mouse brain endothelial cells, we further show that STAT5 activation is both necessary and sufficient for FGF-induced cell migration, invasion and tube formation, which are key events in vascular endothelial morphogenesis and angiogenesis. In contrast, STAT5 is not required for brain endothelial cell mitogenesis. The cytoplasmic tyrosine kinases Src and Janus kinase 2 (Jak2) both appear to be involved in the activation of STAT5, as their inhibition reduces FGF2 and FGF8b induced STAT5 phosphorylation and endothelial cell tube formation. Constitutively active STAT5A partially restores tube formation in the presence of Src or Jak2 inhibitors. These observations demonstrate that FGFs utilize distinct signaling pathways to induce angiogenic phenotypes. Together, our findings implicate the FGF-Jak2/Src-STAT5 cascade as a critical angiogenic FGF signaling pathway. PMID:19176400

DHA inhibited AGEs-induced retinal microglia activation via suppression of the PPARγ/NFκB pathway and reduction of signal transducers in the AGEs/RAGE axis recruitment into lipid rafts.

PubMed

Wang, Li; Chen, Ka; Liu, Kai; Zhou, Yong; Zhang, Ting; Wang, Bin; Mi, Mantian

2015-04-01

Recent studies revealed that dietary intake of docosahexaenoic acid (DHA) prevented diabetic retinopathy (DR), but the underlying mechanism was not fully understood. Retinal microglia are a specialized population of macrophages in retina. Considerable evidence has shown that microglia activation may trigger neuronal death and vascular dysfunction in DR. The aim of this study was to investigate the effects of DHA on advanced glycation end products (AGEs)-induced microglia activation using an in vitro microglia culture system, and concurrently to explore the mediating mechanisms. DHA inhibited AGEs-induced microglia activation and tumor necrosis factor α (TNFα) secretion. These effects of DHA were directly linked with suppression of nuclear factor-kappa B (NFκB) activity, as evident by the reduction of p-IκBα expression, p-NFκB p65 nucleus translocation, NFκB DNA binding activity, and the regulation of gene transcription (TNFα, IL-1β, ICAM-1, and RAGE mRNA). Furthermore, DHA significantly increased phosphorylation of peroxisome proliferator-activated receptor-gamma (PPARγ), and combined with PPARγ stealth RNAi oligonucleotide, we confirmed that DHA inhibition of AGEs-induced microglia activation was partially through the PPARγ/NFκB pathway. Moreover, although AGEs incubation dramatically elevated expression of the cell surface receptor for AGEs (RAGE), DHA significantly inhibited RAGE and Src recruitment into lipid rafts. The AGEs-RAGE axis downstream signal transducers increased mitogen-activated protein kinase (p38 and JNK) phosphorylation. Taken together, DHA might inhibit AGEs-induced microglia activation via suppression of the PPARγ/NFκB pathway, and reduction of RAGE and AGEs/RAGE transducer recruitment into lipid rafts. These results provide a novel potential mechanism for the anti-inflammatory effects of DHA in DR prevention.

Structural and numerical chromosome aberration inducers in liver micronucleus test in rats with partial hepatectomy.

PubMed

Itoh, Satoru; Hattori, Chiharu; Nagata, Mayumi; Sanbuissho, Atsushi

2012-08-30

The liver micronucleus test is an important method to detect pro-mutagens such as active metabolites not reaching bone marrow due to their short lifespan. We have already reported that dosing of the test compound after partial hepatectomy (PH) is essential to detect genotoxicity of numerical chromosome aberration inducers in mice [Mutat. Res. 632 (2007) 89-98]. In naive animals, the proportion of binucleated cells in rats is less than half of that in mice, which suggests a species difference in the response to chromosome aberration inducers. In the present study, we investigated the responses to structural and numerical chromosome aberration inducers in the rat liver micronucleus test. Two structural chromosome aberretion inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical chromosome aberration inducers (colchicine and carbendazim) were used in the present study. PH was performed a day before or after the dosing of the test compound in 8-week old male F344 rats and hepatocytes were isolated 4 days after the PH. As a result, diethylnitrosamine and 1,2-dimethylhydrazine, structural chromosome aberration inducers, exhibited significant increase in the incidence of micronucleated hepatocyte (MNH) when given either before and after PH. Colchicine and carbendazim, numerical chromosome aberration inducers, did not result in any toxicologically significant increase in MNH frequency when given before PH, while they exhibited MNH induction when given after PH. It is confirmed that dosing after PH is essential in order to detect genotoxicity of numerical chromosome aberration inducers in rats as well as in mice. Regarding the species difference, a different temporal response to colchicine was identified. Colchicine increased the incidence of MNH 4 days after PH in rats, although such induction in mice was observed 8-10 days after PH. Copyright © 2012 Elsevier B.V. All rights reserved.

Involvement of P2X7 receptors in retinal ganglion cell apoptosis induced by activated Müller cells.

PubMed

Xue, Bo; Xie, Yuting; Xue, Ying; Hu, Nan; Zhang, Guowei; Guan, Huaijin; Ji, Min

2016-12-01

Müller cell reactivation (gliosis) is an early response in glaucomatous retina. Previous studies have demonstrated that activation of P2X 7 receptors results in retinal ganglion cell (RGC) apoptosis. Here, the issues of whether and how activated Müller cells may contribute to RGC apoptosis through P2X 7 receptors were investigated. Either intravitreal injection of (S)-3,5-dihydroxyphenylglycine (DHPG), a group I metabotropic glutamate receptor (mGluR I) agonist, in normal rat retinas, or DHPG treatment of purified cultured rat retinal Müller cells induced an increase in glial fibrillary acidic protein (GFAP) expression, indicative of Müller cell gliosis. In addition, an increase in adenosine triphosphate (ATP) release from purified cultured Müller cells was detected during DHPG treatment (for 10 min to 48 h), which was mediated by the intracellular mGluR5/Gq/PI-PLC/PKC signaling pathway. Intravitreal injection of DHPG mimicked the reduction in the number of fluorogold retrogradely labeled RGCs in chronic ocular hypertension (COH) rats. Treatment with the conditioned culture medium (CM) obtained from the DHPG-activated Müller cell medium induced an increase in the number of TUNEL-positive cells in cultured RGCs, which was mimicked by benzoylbenzoyl adenosine triphosphate (BzATP), a P2X 7 receptor agonist, but was partially blocked by brilliant blue G (BBG), a P2X 7 receptor antagonist. Moreover, the CM treatment of cultured RGCs significantly increased Bax protein level and decreased Bcl-2 protein level, which was also mimicked by BzATP and partially blocked by BBG, respectively. These results suggest that reactivated Müller cells may release excessive ATP, in turn leading to RGC apoptosis through activating P2X 7 receptors in these cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rare-gas effects on metabolism and inert gas narcosis

NASA Technical Reports Server (NTRS)

1972-01-01

The detailed examination is reported of the theory that narcosis results from expansion of the cell membrane under high partial pressures. The research is partially based on the hypothesis that, like oxygen toxicity, the mechanism of metabolic effects of rare gases may be similar at both low and high pressures and are simply more observable at high pressures. Using adult female goats, the parameters measured include oxygen consumption, CO2 production, respiration rate, heart rate, rectal and skin temperatures and the analysis of electroencephalograms and evoked response. Additionally, the specific activity is measured of plasma glucose subsequent to injection of glucose-UL-C-14, intravenous infusion, specific activity of expired CO2, unesterified fatty acid levels and whole blood lactate-to-pyruvate ratios. Also studied were the effects of acetylsalicylic acid, vitamin E and cationic detergents (which alleviate narcosis) upon metabolic changes induced by high pressure narcosis.

Cinnamic Acid Is Partially Involved in Propolis Immunomodulatory Action on Human Monocytes

PubMed Central

Conti, Bruno José; Búfalo, Michelle Cristiane; Golim, Marjorie de Assis; Sforcin, José Maurício

2013-01-01

Propolis is a beehive product used in traditional medicine due to its biological properties. It shows a complex chemical composition including phenolics, such as cinnamic acid (Ci). The mechanisms of action of propolis have been the subject of research recently; however, the involvement of Ci on propolis activity was not investigated on immune cells. Ci effects were evaluated on human monocytes, assessing the expression of Toll-like receptors (TLRs), HLA-DR, and CD80. Cytokine production (TNF-α and IL-10) and the fungicidal activity of monocytes were evaluated as well. Data showed that Ci downregulated TLR-2, HLA-DR, and CD80 and upregulated TLR-4 expression by human monocytes. High concentrations of Ci inhibited both TNF-α and IL-10 production, whereas the same concentrations induced a higher fungicidal activity against Candida albicans. TNF-α and IL-10 production was decreased by blocking TLR-4, while the fungicidal activity of monocytes was not affected by blocking TLRs. These results suggest that Ci modulated antigen receptors, cytokine production, and the fungicidal activity of human monocytes depending on concentration, and TLR-4 may be involved in its mechanism of action. Ci seemed to be partially involved in propolis activities. PMID:23762102

Dorsal CA1 interneurons contribute to acute stress-induced spatial memory deficits.

PubMed

Yu, Jing-Ying; Fang, Ping; Wang, Chi; Wang, Xing-Xing; Li, Kun; Gong, Qian; Luo, Ben-Yan; Wang, Xiao-Dong

2018-06-01

Exposure to severely stressful experiences disrupts the activity of neuronal circuits and impairs declarative memory. GABAergic interneurons coordinate neuronal network activity, but their involvement in stress-evoked memory loss remains to be elucidated. Here, we provide evidence that interneurons in area CA1 of the dorsal hippocampus partially modulate acute stress-induced memory deficits. In adult male mice, both acute forced swim stress and restraint stress impaired hippocampus-dependent spatial memory and increased the density of c-fos-positive interneurons in the dorsal CA1. Selective activation of dorsal CA1 interneurons by chemogenetics disrupted memory performance in the spatial object recognition task. In comparison, anxiety-related behavior, spatial working memory and novel object recognition memory remained intact when dorsal CA1 interneurons were overactivated. Moreover, chemogenetic activation of dorsal CA1 interneurons suppressed the activity of adjacent pyramidal neurons, whereas a single exposure to forced swim stress but not restraint stress increased the activity of CA1 pyramidal neurons. However, chemogenetic inhibition of dorsal CA1 interneurons led to spatial memory impairments and failed to attenuate acute stress-induced memory loss. These findings suggest that acute stress may overactivate interneurons in the dorsal CA1, which reduces the activity of pyramidal neurons and in turn disrupts long-term memory. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of Streptococcus thermophilus TH-4 in a rat model of doxorubicin-induced mucositis.

PubMed

Wang, Hanru; Brook, Caitlin L; Whittaker, Alexandra L; Lawrence, Andrew; Yazbeck, Roger; Howarth, Gordon S

2013-08-01

Mucositis is a debilitating intestinal side effect of chemotherapeutic regimens. Probiotics have been considered a possible preventative treatment for mucositis. Streptococcus thermophilus TH-4 (TH-4), a newly identified probiotic, has been shown to partially alleviate mucositis induced by administration of the antimetabolite chemotherapy drug, methotrexate in rats; likely mediated through a mechanism of folate production. However, its effects against other classes of chemotherapy drug have yet to be determined. The authors investigated the effects of TH-4 in a rat model of mucositis induced by the anthracycline chemotherapy drug, doxorubicin. Gastrointestinal damage was induced in female Dark Agouti rats (148.3 ± 1.5 g) by intraperitoneal injection of doxorubicin (20 mg/kg). Animals recieved a daily oral gavage of TH-4 at 10(9) cfu/ml or skim milk (vehicle) from days 0 to 8. At day 6, rats were injected with either saline or doxorubicin. At kill, small intestinal tissues were collected for determination of sucrase and myeloperoxidase (MPO) activities and histological assessment. Body weight was significantly decreased by doxorubicin compared with normal controls (p < 0.05). Histological parameters, such as crypt depth and villus height, were also significantly decreased by doxorubicin. TH-4 partially prevented the loss of body weight induced by doxorubicin (2.3% compared with 4%), but provided no further therapeutic benefit. The minimal amelioration of doxorubicin-induced mucositis by TH-4 further supports folate production as a likely mechanism of TH-4 action against methotrexate-induced mucositis. Further studies into TH-4 are required to confirm its applicability to other conventional chemotherapy regimens.

Near infrared radiation protects against oxygen-glucose deprivation-induced neurotoxicity by down-regulating neuronal nitric oxide synthase (nNOS) activity in vitro.

PubMed

Yu, Zhanyang; Li, Zhaoyu; Liu, Ning; Jizhang, Yunneng; McCarthy, Thomas J; Tedford, Clark E; Lo, Eng H; Wang, Xiaoying

2015-06-01

Near infrared radiation (NIR) has been shown to be neuroprotective against neurological diseases including stroke and brain trauma, but the underlying mechanisms remain poorly understood. In the current study we aimed to investigate the hypothesis that NIR may protect neurons by attenuating oxygen-glucose deprivation (OGD)-induced nitric oxide (NO) production and modulating cell survival/death signaling. Primary mouse cortical neurons were subjected to 4 h OGD and NIR was applied at 2 h reoxygenation. OGD significantly increased NO level in primary neurons compared to normal control, which was significantly ameliorated by NIR at 5 and 30 min post-NIR. Neither OGD nor NIR significantly changed neuronal nitric oxide synthase (nNOS) mRNA or total protein levels compared to control groups. However, OGD significantly increased nNOS activity compared to normal control, and this effect was significantly diminished by NIR. Moreover, NIR significantly ameliorated the neuronal death induced by S-Nitroso-N-acetyl-DL-penicillamine (SNAP), a NO donor. Finally, NIR significantly rescued OGD-induced suppression of p-Akt and Bcl-2 expression, and attenuated OGD-induced upregulation of Bax, BAD and caspase-3 activation. These results suggest NIR may protect against OGD at least partially through reducing NO production by down-regulating nNOS activity, and modulating cell survival/death signaling.

Rosmarinus officinalis Extract Suppresses Propionibacterium acnes–Induced Inflammatory Responses

PubMed Central

Tsai, Tsung-Hsien; Chuang, Lu-Te; Lien, Tsung-Jung; Liing, Yau-Rong; Chen, Wei-Yu

2013-01-01

Abstract Propionibacterium acnes is a key pathogen involved in the progression of acne inflammation. The development of a new agent possessing antimicrobial and anti-inflammatory activity against P. acnes is therefore of interest. In this study, we investigated the inhibitory effect of rosemary (Rosmarinus officinalis) extract on P. acnes–induced inflammation in vitro and in vivo. The results showed that ethanolic rosemary extract (ERE) significantly suppressed the secretion and mRNA expression of proinflammatory cytokines, including interleukin (IL)-8, IL-1β, and tumor necrosis factor-α in P. acnes–stimulated monocytic THP-1 cells. In an in vivo mouse model, concomitant intradermal injection of ERE attenuated the P. acnes–induced ear swelling and granulomatous inflammation. Since ERE suppressed the P. acnes–induced nuclear factor kappa-B (NF-κB) activation and mRNA expression of Toll-like receptor (TLR) 2, the suppressive effect of ERE might be due, at least partially, to diminished NF-κB activation and TLR2-mediated signaling pathways. Furthermore, three major constituents of ERE, carnosol, carnosic acid, and rosmarinic acid, exerted different immumodulatory activities in vitro. In brief, rosmarinic acid significantly suppressed IL-8 production, while the other two compounds inhibited IL-1β production. Further study is needed to explore the role of bioactive compounds of rosemary in mitigation of P. acnes–induced inflammation. PMID:23514231

Tunicamycin promotes apoptosis in leukemia cells through ROS generation and downregulation of survivin expression.

PubMed

Lim, Eun Jin; Heo, Jeonghoon; Kim, Young-Ho

2015-08-01

Tunicamycin (TN), one of the endoplasmic reticulum stress inducers, has been reported to inhibit tumor cell growth and exhibit anticarcinogenic activity. However, the mechanism by which TN initiates apoptosis remains poorly understood. In the present study, we investigated the effect of TN on the apoptotic pathway in U937 cells. We show that TN induces apoptosis in association with caspase-3 activation, generation of reactive oxygen species (ROS), and downregulation of survivin expression. P38 MAPK (mitogen-activated protein kinase) and the generation of ROS signaling pathway play crucial roles in TN-induced apoptosis in U937 cells. We hypothesized that TN-induced activation of p38 MAPK signaling pathway is responsible for cell death. To test this hypothesis, we selectively inhibited MAPK during treatment with TN. Our data demonstrated that inhibitor of p38 (SB), but not ERK (PD) or JNK (SP), partially maintained apoptosis during treatment with TN. Pre-treatment with NAC and GSH markedly prevented cell death, suggesting a role for ROS in this process. Ectopic expression of survivin in U937 cells attenuated TN-induced apoptosis by suppression of caspase-3 cleavage, mitochondrial membrane potential, and cytochrome c release in U937 cells. Taken together, our results show that TN modulates multiple components of the apoptotic response of human leukemia cells and raise the possibility of a novel therapeutic strategy for hematological malignancies.

The cachectic mediator proteolysis inducing factor activates NF-kappaB and STAT3 in human Kupffer cells and monocytes.

PubMed

Watchorn, Tammy M; Dowidar, Nabil; Dejong, Cornelis H C; Waddell, Ian D; Garden, O James; Ross, James A

2005-10-01

A novel proteoglycan, proteolysis inducing factor (PIF), is capable of inducing muscle proteolysis during the process of cancer cachexia, and of inducing an acute phase response in human hepatocytes. We investigated whether PIF is able to activate pro-inflammatory pathways in human Kupffer cells, the resident macrophages of the liver, and in monocytes, resulting in the production of pro-inflammatory cytokines. Normal liver tissue was obtained from patients undergoing partial hepatectomy and Kupffer cells were isolated. Monocytes were isolated from peripheral blood. Following exposure to native PIF, pro-inflammatory cytokine production from Kupffer cells and monocytes was measured and the NF-kappaB and STAT3 transcriptional pathways were investigated using electrophoretic mobility shift assays. We demonstrate that PIF is able to activate the transcription factor NF-kappaB and NF-kappaB-inducible genes in human Kupffer cells, and in monocytes, resulting in the production of pro-inflammatory cytokines such as TNF-alpha, IL-8 and IL-6. PIF enhances the expression of the cell surface molecules LFA-1 and CD14 on macrophages. PIF also activates the transcription factor STAT3 in Kupffer cells. The pro-inflammatory effects of PIF, mediated via NF-kappaB and STAT3, are important in macrophage behaviour and may contribute to the inflammatory pro-cachectic process in the liver.

Butyric Acid-Induced T-Cell Apoptosis Is Mediated by Caspase-8 and -9 Activation in a Fas-Independent Manner

PubMed Central

Kurita-Ochiai, Tomoko; Ochiai, Kuniyasu; Fukushima, Kazuo

2001-01-01

Our previous study demonstrated that butyric acid, an extracellular metabolite of periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat cells. In this study, we examined whether CD95 ligand-receptor interaction is involved in butyric acid-induced T-cell apoptosis. Flow cytometry analysis indicated that expression of Fas in Jurkat and T cells from peripheral blood mononuclear cells was not affected by butyric acid treatment. Furthermore, the expression of Fas and FasL protein in Western blotting was not affected by butyric acid treatment. Coincubation with blocking anti-Fas antibodies prevented Fas-induced apoptosis but not butyric acid-induced apoptosis. Anti-FasL antibodies also did not prevent butyric acid-induced apoptosis at any dose examined. Although cytotoxic anti-Fas antibody affected butyric acid-induced apoptosis, a synergistic effect was not seen. Time-dependent activation of caspase-8 and -9 was recognized in butyric acid- as well as Fas-mediated apoptosis. IETD-CHO and LEHD-CHO, specific inhibitors of caspase-8 and -9, respectively, completely blocked Fas-mediated apoptosis and partially prevented butyric acid-induced apoptosis. These results suggest that the Fas-FasL interaction is not involved in butyric acid-induced apoptosis and that caspase-8 and -9-dependent apoptosis plays an important role in butyric acid-induced apoptosis, as well as Fas-induced apoptosis. PMID:11238216

A Chinese herbal medicine, jia-wei-xiao-yao-san, prevents dimethylnitrosamine-induced hepatic fibrosis in rats.

PubMed

Chien, Shu-Chen; Chang, Wei-Chiao; Lin, Pu-Hua; Chang, Wei-Pin; Hsu, Shih-Chung; Chang, Jung-Chen; Wu, Ya-Chieh; Pei, Jin-Kuo; Lin, Chia-Hsien

2014-01-01

Jia-wei-xiao-yao-san (JWXYS) is a traditional Chinese herbal medicine that is widely used to treat neuropsychological disorders. Only a few of the hepatoprotective effects of JWXYS have been studied. The aim of this study was to investigate the hepatoprotective effects of JWXYS on dimethylnitrosamine- (DMN-) induced chronic hepatitis and hepatic fibrosis in rats and to clarify the mechanism through which JWXYS exerts these effects. After the rats were treated with DMN for 3 weeks, serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) levels were significantly elevated, whereas the albumin level decreased. Although DMN was continually administered, after the 3 doses of JWXYS were orally administered, the SGOT and SGPT levels significantly decreased and the albumin level was significantly elevated. In addition, JWXYS treatment prevented liver fibrosis induced by DMN. JWXYS exhibited superoxide-dismutase-like activity and dose-dependently inhibited DMN-induced lipid peroxidation and xanthine oxidase activity in the liver of rats. Our findings suggest that JWXYS exerts antifibrotic effects against DMN-induced chronic hepatic injury. The possible mechanism is at least partially attributable to the ability of JWXYS to inhibit reactive-oxygen-species-induced membrane lipid peroxidation.

Psilocybin-induced stimulus control in the rat.

PubMed

Winter, J C; Rice, K C; Amorosi, D J; Rabin, R A

2007-10-01

Although psilocybin has been trained in the rat as a discriminative stimulus, little is known of the pharmacological receptors essential for stimulus control. In the present investigation rats were trained with psilocybin and tests were then conducted employing a series of other hallucinogens and presumed antagonists. An intermediate degree of antagonism of psilocybin was observed following treatment with the 5-HT(2A) receptor antagonist, M100907. In contrast, no significant antagonism was observed following treatment with the 5-HT(1A/7) receptor antagonist, WAY-100635, or the DA D(2) antagonist, remoxipride. Psilocybin generalized fully to DOM, LSD, psilocin, and, in the presence of WAY-100635, DMT while partial generalization was seen to 2C-T-7 and mescaline. LSD and MDMA partially generalized to psilocybin and these effects were completely blocked by M-100907; no generalization of PCP to psilocybin was seen. The present data suggest that psilocybin induces a compound stimulus in which activity at the 5-HT(2A) receptor plays a prominent but incomplete role. In addition, psilocybin differs from closely related hallucinogens such as 5-MeO-DMT in that agonism at 5-HT(1A) receptors appears to play no role in psilocybin-induced stimulus control.

Psilocybin-induced stimulus control in the rat

PubMed Central

Winter, J.C.; Rice, K.C.; Amorosi, D.J.; Rabin, R.A.

2007-01-01

Although psilocybin has been trained in the rat as a discriminative stimulus, little is known of the pharmacological receptors essential for stimulus control. In the present investigation rats were trained with psilocybin and tests were then conducted employing a series of other hallucinogens and presumed antagonists. An intermediate degree of antagonism of psilocybin was observed following treatment with the 5-HT2A receptor antagonist, M100907. In contrast, no significant antagonism was observed following treatment with the 5-HT1A/7 receptor antagonist, WAY-100635, or the DA D2 antagonist, remoxipride. Psilocybin generalized fully to DOM, LSD, psilocin, and, in the presence of WAY-100635, DMT while partial generalization was seen to 2C-T-7 and mescaline. LSD and MDMA partially generalized to psilocybin and these effects were completely blocked by M-100907; no generalization of PCP to psilocybin was seen. The present data suggest that psilocybin induces a compound stimulus in which activity at the 5-HT2A receptor plays a prominent but incomplete role. In addition, psilocybin differs from closely related hallucinogens such as 5-MeO-DMT in that agonism at 5-HT1A receptors appears to play no role in psilocybin-induced stimulus control. PMID:17688928

Protein Kinase B Activation and Lamellipodium Formation Are Independent Phosphoinositide 3-Kinase-Mediated Events Differentially Regulated by Endogenous Ras

PubMed Central

van Weering, David H. J.; de Rooij, Johan; Marte, Barbara; Downward, Julian; Bos, Johannes L.; Burgering, Boudewijn M. T.

1998-01-01

Regulation of phosphoinositide 3-kinase (PI 3-kinase) can occur by binding of the regulatory p85 subunit to tyrosine-phosphorylated proteins and by binding of the p110 catalytic subunit to activated Ras. However, the way in which these regulatory mechanisms act to regulate PI 3-kinase in vivo is unclear. Here we show that several growth factors (basic fibroblast growth factor [bFGF], platelet-derived growth factor [PDGF], and epidermal growth factor [EGF; to activate an EGF receptor-Ret chimeric receptor]) all activate PI 3-kinase in vivo in the neuroectoderm-derived cell line SKF5. However, these growth factors differ in their ability to activate PI 3-kinase-dependent signaling. PDGF and EGF(Ret) treatment induced PI 3-kinase-dependent lamellipodium formation and protein kinase B (PKB) activation. In contrast, bFGF did not induce lamellipodium formation but activated PKB, albeit to a small extent. PDGF and EGF(Ret) stimulation resulted in binding of p85 to tyrosine-phosphorylated proteins and strong Ras activation. bFGF, however, induced only strong activation of Ras. In addition, while RasAsn17 abolished bFGF activation of PKB, PDGF- and EGF(Ret)-induced PKB activation was only partially inhibited and lamellipodium formation was unaffected. Interestingly, in contrast to activation of only endogenous Ras (bFGF), ectopic expression of activated Ras did result in lamellipodium formation. From this we conclude that, in vivo, p85 and Ras synergize to activate PI 3-kinase and that strong activation of only endogenous Ras exerts a small effect on PI 3-kinase activity, sufficient for PKB activation but not lamellipodium formation. This differential sensitivity to PI 3-kinase activation could be explained by our finding that PKB activation and lamellipodium formation are independent PI 3-kinase-induced events. PMID:9528752

The underlying mechanism of proinflammatory NF-κB activation by the mTORC2/Akt/IKKα pathway during skin aging

PubMed Central

Choi, Yeon Ja; Moon, Kyoung Mi; Chung, Ki Wung; Jeong, Ji Won; Park, Daeui; Kim, Dae Hyun; Yu, Byung Pal; Chung, Hae Young

2016-01-01

Mammalian target of rapamycin complex 2 (mTORC2), one of two different enzymatic complexes of mTOR, regulates a diverse set of substrates including Akt. mTOR pathway is one of well-known mediators of aging process, however, its role in skin aging has not been determined. Skin aging can be induced by physical age and ultraviolet (UV) irradiation which are intrinsic and extrinsic factors, respectively. Here, we report increased mTORC2 pathway in intrinsic and photo-induced skin aging, which is implicated in the activation of nuclear factor-κB (NF-κB). UVB-irradiated or aged mice skin revealed that mTORC2 activity and its component, rictor were significantly upregulated which in turn increased Akt activation and Akt-dependent IκB kinase α (IKKα) phosphorylation at Thr23 in vivo. We also confirmed that UVB induced the mTORC2/Akt/IKKα signaling pathway with HaCaT human normal keratinocytes. The increased mTORC2 signaling pathway during skin aging were associated to NF-κB activation. Suppression of mTORC2 activity by the treatment of a mTOR small inhibitor or knockdown of RICTOR partially rescued UVB-induced NF-κB activation through the downregulation of Akt/IKKα activity. Our data demonstrated the upregulation of mTORC2 pathway in intrinsic and photo-induced skin aging and its role in IKKα/NF-κB activation. These data not only expanded the functions of mTOR to skin aging but also revealed the therapeutic potential of inhibiting mTORC2 in ameliorating both intrinsic skin aging and photoaging. PMID:27486771

Life-threatening bleeding in a case of autoantibody-induced factor VII deficiency.

PubMed

Okajima, K; Ishii, M

1999-02-01

A male patient presented with life-threatening bleeding induced by autoantibody-induced factor VII (F.VII) deficiency. This patient had macroscopic hematuria, skin ecchymosis, gastrointestinal bleeding, and a neck hematoma that was causing disturbed respiration. He developed acute renal failure and acute hepatic failure, probably due to obstruction of the ureters and the biliary tract, respectively. Although activated partial thromboplastin time was normal, prothrombin time (PT) was remarkably prolonged at 71.8 seconds compared to 14.0 seconds in a normal control. Both the immunoreactive level of F.VII antigen and the F.VII activity of the patient's plasma samples were < 1.0% of normal. Although an equal part of normal plasma was added to the patient's plasma, PT was not corrected. The patient's plasma inhibited F.VII activity. These findings suggested the presence of a plasma inhibitor for F.VII. After administration of large doses of methylprednisolone, PT was gradually shortened and plasma levels of F.VII increased over time. Bleeding, acute renal failure, and acute hepatic failure improved markedly following the steroid treatment. These observations suggest that life-threatening bleeding can be induced by autoantibody-induced F.VII deficiency and that immunosuppressive therapy using large doses of steroid can be successful in inhibiting the production of the autoantibody.

Study of commonly used organophosphate pesticides that induced oxidative stress and apoptosis in peripheral blood lymphocytes of rats.

PubMed

Ojha, A; Gupta, Y K

2017-11-01

In a previous study, we have found that organophosphate (OP) pesticides such as chlorpyrifos (CPF), methyl parathion (MPT), and malathion (MLT) significantly induced genotoxicity in peripheral blood lymphocytes of rats. To explore the mechanism of OP-induced genotoxicity, we measured the formation of DNA interstrand cross-links (DICs) and apoptosis in peripheral blood lymphocytes of rats. Peripheral blood lymphocytes of rats were treated with CPF, MPT, and MLT individually and in combination at concentrations of 0.1 and 0.25 LC 50 for 2, 4, 8, and 12 h at 37°C. Lipid peroxidation (LPO) was measured as a biomarker of oxidative stress. Apoptosis induced by CPF, MPT, and MLT individually and in combination was determined by measuring the intracellular level of active caspase-3 and caspase-9 by spectrofluorimetry. We found significant dose- and time-dependent increases in LPO, DICs formation and increase of intracellular active caspase-3 and caspase-9 in exposed peripheral blood lymphocytes of rats. These findings suggest that the studied pesticides have potential to induce oxidative stress, cause DNA adduct formation, and cause failure of adduct repair, which leads to apoptosis that is partially mediated by activation of intracellular caspase-3 and caspase-9.

Role of GABA Deficit in Sensitivity to the Psychotomimetic Effects of Amphetamine.

PubMed

Ahn, Kyung-Heup; Sewell, Andrew; Elander, Jacqueline; Pittman, Brian; Ranganathan, Mohini; Gunduz-Bruce, Handan; Krystal, John; D'Souza, Deepak Cyril

2015-11-01

Some schizophrenia patients are more sensitive to amphetamine (AMPH)-induced exacerbations in psychosis-an effect that correlates with higher striatal dopamine release. This enhanced vulnerability may be related to gamma-aminobutyric acid (GABA) deficits observed in schizophrenia. We hypothesized that a pharmacologically induced GABA deficit would create vulnerability to the psychotomimetic effects to the 'subthreshold' dose of AMPH in healthy subjects, which by itself would not induce clinically significant increase in positive symptoms. To test this hypothesis, a GABA deficit was induced by intravenous infusion of iomazenil (IOM; 3.7 μg/kg), an antagonist and partial inverse agonist of benzodiazepine receptor. A subthreshold dose of AMPH (0.1 mg/kg) was administered by intravenous infusion. Healthy subjects received placebo IOM followed by placebo AMPH, active IOM followed by placebo AMPH, placebo IOM followed by active AMPH, and active IOM followed by active AMPH in a randomized, double-blind crossover design over 4 test days. Twelve healthy subjects who had a subclinical response to active AMPH alone were included in the analysis. Psychotomimetic effects (Positive and Negative Syndrome Scale (PANSS)), perceptual alterations (Clinician Administered Dissociative Symptoms Scale (CADSS)), and subjective effects (visual analog scale) were captured before and after the administration of drugs. IOM significantly augmented AMPH-induced peak changes in PANSS positive symptom subscale and both subjective and objective CADSS scores. There were no pharmacokinetic interactions. In conclusion, GABA deficits increased vulnerability to amphetamine-induced psychosis-relevant effects in healthy subjects, suggesting that pre-existing GABA deficits may explain why a subgroup of schizophrenia patients are vulnerable to AMPH.

Partial mGlu₅ Negative Allosteric Modulators Attenuate Cocaine-Mediated Behaviors and Lack Psychotomimetic-Like Effects.

PubMed

Gould, Robert W; Amato, Russell J; Bubser, Michael; Joffe, Max E; Nedelcovych, Michael T; Thompson, Analisa D; Nickols, Hilary H; Yuh, Johannes P; Zhan, Xiaoyan; Felts, Andrew S; Rodriguez, Alice L; Morrison, Ryan D; Byers, Frank W; Rook, Jerri M; Daniels, John S; Niswender, Colleen M; Conn, P Jeffrey; Emmitte, Kyle A; Lindsley, Craig W; Jones, Carrie K

2016-03-01

Cocaine abuse remains a public health concern for which pharmacotherapies are largely ineffective. Comorbidities between cocaine abuse, depression, and anxiety support the development of novel treatments targeting multiple symptom clusters. Selective negative allosteric modulators (NAMs) targeting the metabotropic glutamate receptor 5 (mGlu5) subtype are currently in clinical trials for the treatment of multiple neuropsychiatric disorders and have shown promise in preclinical models of substance abuse. However, complete blockade or inverse agonist activity by some full mGlu5 NAM chemotypes demonstrated adverse effects, including psychosis in humans and psychotomimetic-like effects in animals, suggesting a narrow therapeutic window. Development of partial mGlu5 NAMs, characterized by their submaximal but saturable levels of blockade, may represent a novel approach to broaden the therapeutic window. To understand potential therapeutic vs adverse effects in preclinical behavioral assays, we examined the partial mGlu5 NAMs, M-5MPEP and Br-5MPEPy, in comparison with the full mGlu5 NAM MTEP across models of addiction and psychotomimetic-like activity. M-5MPEP, Br-5MPEPy, and MTEP dose-dependently decreased cocaine self-administration and attenuated the discriminative stimulus effects of cocaine. M-5MPEP and Br-5MPEPy also demonstrated antidepressant- and anxiolytic-like activity. Dose-dependent effects of partial and full mGlu5 NAMs in these assays corresponded with increasing in vivo mGlu5 occupancy, demonstrating an orderly occupancy-to-efficacy relationship. PCP-induced hyperlocomotion was potentiated by MTEP, but not by M-5MPEP and Br-5MPEPy. Further, MTEP, but not M-5MPEP, potentiated the discriminative-stimulus effects of PCP. The present data suggest that partial mGlu5 NAM activity is sufficient to produce therapeutic effects similar to full mGlu5 NAMs, but with a broader therapeutic index.

Comparison of exogenous surfactant therapy, mechanical ventilation with high end-expiratory pressure and partial liquid ventilation in a model of acute lung injury.

PubMed

Hartog, A; Vazquez de Anda, G F; Gommers, D; Kaisers, U; Verbrugge, S J; Schnabel, R; Lachmann, B

1999-01-01

We have compared three treatment strategies, that aim to prevent repetitive alveolar collapse, for their effect on gas exchange, lung mechanics, lung injury, protein transfer into the alveoli and surfactant system, in a model of acute lung injury. In adult rats, the lungs were ventilated mechanically with 100% oxygen and a PEEP of 6 cm H2O, and acute lung injury was induced by repeated lung lavage to obtain a PaO2 value < 13 kPa. Animals were then allocated randomly (n = 12 in each group) to receive exogenous surfactant therapy, ventilation with high PEEP (18 cm H2O), partial liquid ventilation or ventilation with low PEEP (8 cm H2O) (ventilated controls). Blood-gas values were measured hourly. At the end of the 4-h study, in six animals per group, pressure-volume curves were constructed and bronchoalveolar lavage (BAL) was performed, whereas in the remaining animals lung injury was assessed. In the ventilated control group, arterial oxygenation did not improve and protein concentration of BAL and conversion of active to non-active surfactant components increased significantly. In the three treatment groups, PaO2 increased rapidly to > 50 kPa and remained stable over the next 4 h. The protein concentration of BAL fluid increased significantly only in the partial liquid ventilation group. Conversion of active to non-active surfactant components increased significantly in the partial liquid ventilation group and in the group ventilated with high PEEP. In the surfactant group and partial liquid ventilation groups, less lung injury was found compared with the ventilated control group and the group ventilated with high PEEP. We conclude that although all three strategies improved PaO2 to > 50 kPa, the impact on protein transfer into the alveoli, surfactant system and lung injury differed markedly.

Phosphorylation of a NAC Transcription Factor by a Calcium/Calmodulin-Dependent Protein Kinase Regulates Abscisic Acid-Induced Antioxidant Defense in Maize [Phosphorylation of a NAC Transcription Factor by ZmCCaMK Regulates Abscisic Acid-Induced Antioxidant Defense in Maize

DOE PAGES

Zhu, Yuan; Yan, Jingwei; Liu, Weijuan; ...

2016-05-10

Calcium/calmodulin-dependent protein kinase (CCaMK) has been shown to play an important role in abscisic acid (ABA)-induced antioxidant defense and enhance the tolerance of plants to drought stress. However, its downstream molecular events are poorly understood. Here, we identify a NAC transcription factor, ZmNAC84, in maize, which physically interacts with ZmCCaMK in vitro and in vivo. ZmNAC84 display a partially overlapping expression pattern with ZmCCaMK after ABA treatment and H 2O 2 is required for ABA-induced ZmNAC84 expression. Functional analysis reveals that ZmNAC84 is essential for ABA-induced antioxidant defense in a ZmCCaMK-dependent manner. Furthermore, ZmCCaMK directly phosphorylates S113 of ZmNAC84 inmore » vitro, and S113 is essential for the ABA-induced stimulation of antioxidant defense by ZmCCaMK. Moreover, overexpression of ZmNAC84 in tobacco can improve drought tolerance, and alleviate drought-induced oxidative damage of transgenic plants. These results define a mechanism for ZmCCaMK function in ABA-induced antioxidant defense, where ABA-produced H 2O 2 first induces expression of ZmCCaMK and ZmNAC84 and activates ZmCCaMK, and subsequently the activated ZmCCaMK phosphorylates ZmNAC84 at S113, thereby inducing antioxidant defense by activating downstream genes.« less

Phosphorylation of a NAC Transcription Factor by a Calcium/Calmodulin-Dependent Protein Kinase Regulates Abscisic Acid-Induced Antioxidant Defense in Maize [Phosphorylation of a NAC Transcription Factor by ZmCCaMK Regulates Abscisic Acid-Induced Antioxidant Defense in Maize

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

Zhu, Yuan; Yan, Jingwei; Liu, Weijuan

Calcium/calmodulin-dependent protein kinase (CCaMK) has been shown to play an important role in abscisic acid (ABA)-induced antioxidant defense and enhance the tolerance of plants to drought stress. However, its downstream molecular events are poorly understood. Here, we identify a NAC transcription factor, ZmNAC84, in maize, which physically interacts with ZmCCaMK in vitro and in vivo. ZmNAC84 display a partially overlapping expression pattern with ZmCCaMK after ABA treatment and H 2O 2 is required for ABA-induced ZmNAC84 expression. Functional analysis reveals that ZmNAC84 is essential for ABA-induced antioxidant defense in a ZmCCaMK-dependent manner. Furthermore, ZmCCaMK directly phosphorylates S113 of ZmNAC84 inmore » vitro, and S113 is essential for the ABA-induced stimulation of antioxidant defense by ZmCCaMK. Moreover, overexpression of ZmNAC84 in tobacco can improve drought tolerance, and alleviate drought-induced oxidative damage of transgenic plants. These results define a mechanism for ZmCCaMK function in ABA-induced antioxidant defense, where ABA-produced H 2O 2 first induces expression of ZmCCaMK and ZmNAC84 and activates ZmCCaMK, and subsequently the activated ZmCCaMK phosphorylates ZmNAC84 at S113, thereby inducing antioxidant defense by activating downstream genes.« less

ERK1/2 mediates glucose-regulated POMC gene expression in hypothalamic neurons.

PubMed

Zhang, Juan; Zhou, Yunting; Chen, Cheng; Yu, Feiyuan; Wang, Yun; Gu, Jiang; Ma, Lian; Ho, Guyu

2015-04-01

Hypothalamic glucose-sensing neurons regulate the expression of genes encoding feeding-related neuropetides POMC, AgRP, and NPY - the key components governing metabolic homeostasis. AMP-activated protein kinase (AMPK) is postulated to be the molecular mediator relaying glucose signals to regulate the expression of these neuropeptides. Whether other signaling mediator(s) plays a role is not clear. In this study, we investigated the role of ERK1/2 using primary hypothalamic neurons as the model system. The primary neurons were differentiated from hypothalamic progenitor cells. The differentiated neurons possessed the characteristic neuronal cell morphology and expressed neuronal post-mitotic markers as well as leptin-regulated orexigenic POMC and anorexigenic AgRP/NPY genes. Treatment of cells with glucose dose-dependently increased POMC and decreased AgRP/NPY expression with a concurrent suppression of AMPK phosphorylation. In addition, glucose treatment dose-dependently increased the ERK1/2 phosphorylation. Blockade of ERK1/2 activity with its specific inhibitor PD98059 partially (approximately 50%) abolished glucose-induced POMC expression, but had little effect on AgRP/NPY expression. Conversely, blockade of AMPK activity with its specific inhibitor produced a partial (approximately 50%) reversion of low-glucose-suppressed POMC expression, but almost completely blunted the low-glucose-induced AgRP/NPY expression. The results indicate that ERK1/2 mediated POMC but not AgRP/NPY expression. Confirming the in vitro findings, i.c.v. administration of PD98059 in rats similarly attenuated glucose-induced POMC expression in the hypothalamus, but again had little effect on AgRP/NPY expression. The results are indicative of a novel role of ERK1/2 in glucose-regulated POMC expression and offer new mechanistic insights into hypothalamic glucose sensing. © 2015 Society for Endocrinology.

Soyabean glycinin depresses intestinal growth and function in juvenile Jian carp (Cyprinus carpio var Jian): protective effects of glutamine.

PubMed

Jiang, Wei-Dan; Hu, Kai; Zhang, Jin-Xiu; Liu, Yang; Jiang, Jun; Wu, Pei; Zhao, Juan; Kuang, Sheng-Yao; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Zhou, Xiao-Qiu; Feng, Lin

2015-11-28

This study investigated the effects of glycinin on the growth, intestinal oxidative status, tight junction components, cytokines and apoptosis signalling factors of fish. The results showed that an 80 g/kg diet of glycinin exposure for 42 d caused poor growth performance and depressed intestinal growth and function of juvenile Jian carp (Cyprinus carpio var. Jian). Meanwhile, dietary glycinin exposure induced increases in lipid peroxidation and protein oxidation; it caused reductions in superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities; and it increased MnSOD, CuZnSOD, GPx1b and GPx4a mRNA levels, suggesting an adaptive mechanism against stress in the intestines of fish. However, dietary glycinin exposure decreased both the activity and mRNA levels of nine isoforms of glutathione-S-transferase (GST) (α, μ, π, ρ, θ, κ, mGST1, mGST2 and mGST3), indicating toxicity to this enzyme activity and corresponding isoform gene expressions. In addition, glycinin exposure caused partial disruption of intestinal cell-cell tight junction components, disturbances of cytokines and induced apoptosis signalling in the distal intestines>mid intestines>proximal intestines of fish. Glycinin exposure also disturbed the mRNA levels of intestinal-related signalling factors Nrf2, Keap1a, Keap1b, eleven isoforms of protein kinase C and target of rapamycin/4E-BP. Interestingly, glutamine was observed to partially block those negative influences. In conclusion, this study indicates that dietary glycinin exposure causes intestinal oxidative damage and disruption of intestinal physical barriers and functions and reduces fish growth, but glutamine can reverse those negative effects in fish. This study provides some information on the mechanism of glycinin-induced negative effects.

The G‐protein biased partial κ opioid receptor agonist 6′‐GNTI blocks hippocampal paroxysmal discharges without inducing aversion

PubMed Central

Zangrandi, Luca; Burtscher, Johannes; MacKay, James P; Colmers, William F

2016-01-01

Background and Purpose With a prevalence of 1–2%, epilepsies belong to the most frequent neurological diseases worldwide. Although antiepileptic drugs are available since several decades, the incidence of patients that are refractory to medication is still over 30%. Antiepileptic effects of κ opioid receptor (κ receptor) agonists have been proposed since the 1980s. However, their clinical use was hampered by dysphoric side effects. Recently, G‐protein biased κ receptor agonists were developed, suggesting reduced aversive effects. Experimental Approach We investigated the effects of the κ receptor agonist U‐50488H and the G‐protein biased partial κ receptor agonist 6′‐GNTI in models of acute seizures and drug‐resistant temporal lobe epilepsy and in the conditioned place avoidance (CPA) test. Moreover, we performed slice electrophysiology to understand the functional mechanisms of 6′‐GNTI. Key Results As previously shown for U‐50488H, 6′‐GNTI markedly increased the threshold for pentylenetetrazole‐induced seizures. All treated mice displayed reduced paroxysmal activity in response to U‐50488H (20 mg·kg−1) or 6′‐GNTI (10–30 nmoles) treatment in the mouse model of intra‐hippocampal injection of kainic acid. Single cell recordings on hippocampal pyramidal cells revealed enhanced inhibitory signalling as potential mechanisms causing the reduction of paroxysmal activity. Effects of 6′‐GNTI were blocked in both seizure models by the κ receptor antagonist 5′‐GNTI. Moreover, 6′‐GNTI did not induce CPA, a measure of aversive effects, while U‐50488H did. Conclusions and Implications Our data provide the proof of principle that anticonvulsant/antiseizure and aversive effects of κ receptor activation can be pharmacologically separated in vivo. PMID:26928671

Total body nitrogen analysis. [neutron activation analysis

NASA Technical Reports Server (NTRS)

Palmer, H. E.

1975-01-01

Studies of two potential in vivo neutron activation methods for determining total and partial body nitrogen in animals and humans are described. A method using the CO-11 in the expired air as a measure of nitrogen content was found to be adequate for small animals such as rats, but inadequate for human measurements due to a slow excretion rate. Studies on the method of measuring the induced N-13 in the body show that with further development, this method should be adequate for measuring muscle mass changes occurring in animals or humans during space flight.

Peroxisome Proliferator-Activated Receptors (PPARs) as Potential Inducers of Antineoplastic Effects in CNS Tumors

PubMed Central

Tatenhorst, Lars; Hahnen, Eric; Heneka, Michael T.

2008-01-01

The peroxisome proliferator-activated receptors (PPARs) are ligand-inducible transcription factors which belong to the superfamily of nuclear hormone receptors. In recent years it turned out that natural as well as synthetic PPAR agonists exhibit profound antineoplastic as well as redifferentiation effects in tumors of the central nervous system (CNS). The molecular understanding of the underlying mechanisms is still emerging, with partially controverse findings reported by a number of studies dealing with the influence of PPARs on treatment of tumor cells in vitro. Remarkably, studies examining the effects of these drugs in vivo are just beginning to emerge. However, the agonists of PPARs, in particular the thiazolidinediones, seem to be promising candidates for new approaches in human CNS tumor therapy. PMID:18725982

Arousal from sleep does not lead to reduced dilator muscle activity or elevated upper airway resistance on return to sleep in healthy individuals.

PubMed

Jordan, Amy S; Cori, Jennifer M; Dawson, Andrew; Nicholas, Christian L; O'Donoghue, Fergal J; Catcheside, Peter G; Eckert, Danny J; McEvoy, R Doug; Trinder, John

2015-01-01

To compare changes in end-tidal CO2, genioglossus muscle activity and upper airway resistance following tone-induced arousal and the return to sleep in healthy individuals with small and large ventilatory responses to arousal. Observational study. Two sleep physiology laboratories. 35 men and 25 women with no medical or sleep disorders. Auditory tones to induce 3-s to 15-s cortical arousals from sleep. During arousal from sleep, subjects with large ventilatory responses to arousal had higher ventilation (by analytical design) and tidal volume, and more marked reductions in the partial pressure of end-tidal CO2 compared to subjects with small ventilatory responses to arousal. However, following the return to sleep, ventilation, genioglossus muscle activity, and upper airway resistance did not differ between high and low ventilatory response groups (Breath 1 on return to sleep: ventilation 6.7±0.4 and 5.5±0.3 L/min, peak genioglossus activity 3.4%±1.0% and 4.8%±1.0% maximum, upper airway resistance 4.7±0.7 and 5.5±1.0 cm H2O/L/s, respectively). Furthermore, dilator muscle activity did not fall below the pre-arousal sleeping level and upper airway resistance did not rise above the pre-arousal sleeping level in either group for 10 breaths following the return to sleep. Regardless of the magnitude of the ventilatory response to arousal from sleep and subsequent reduction in PETCO2, healthy individuals did not develop reduced dilator muscle activity nor increased upper airway resistance, indicative of partial airway collapse, on the return to sleep. These findings challenge the commonly stated notion that arousals predispose to upper airway obstruction. © 2014 Associated Professional Sleep Societies, LLC.

Roles for the Mitogen-activated Protein Kinase (MAPK) Phosphatase, DUSP1, in Feedback Control of Inflammatory Gene Expression and Repression by Dexamethasone*

PubMed Central

Shah, Suharsh; King, Elizabeth M.; Chandrasekhar, Ambika; Newton, Robert

2014-01-01

Glucocorticoids act on the glucocorticoid receptor (NR3C1) to repress inflammatory gene expression. This is central to their anti-inflammatory effectiveness and rational improvements in therapeutic index depend on understanding the mechanism. Human pulmonary epithelial A549 cells were used to study the role of the mitogen-activated protein kinase (MAPK) phosphatase, dual-specificity phosphatase 1 (DUSP1), in the dexamethasone repression of 11 inflammatory genes induced, in a MAPK-dependent manner, by interleukin-1β (IL1B). Adenoviral over-expression of DUSP1 inactivated MAPK pathways and reduced expression of all 11 inflammatory genes. IL1B rapidly induced DUSP1 expression and RNA silencing revealed a transient role in feedback inhibition of MAPKs and inflammatory gene expression. With dexamethasone, which induced DUSP1 expression, plus IL1B (co-treatment), DUSP1 expression was further enhanced. At 1 h, this was responsible for the dexamethasone inhibition of IL1B-induced MAPK activation and CXCL1 and CXCL2 mRNA expression, with a similar trend for CSF2. Whereas, CCL20 mRNA was not repressed by dexamethasone at 1 h, repression of CCL2, CXCL3, IL6, and IL8 was unaffected, and PTGS2 repression was partially affected by DUSP1 knockdown. At later times, dexamethasone repression of MAPKs was unaffected by DUSP1 silencing. Likewise, 6 h post-IL1B, dexamethasone repression of all 11 mRNAs was essentially unaffected by DUSP1 knockdown. Qualitatively similar data were obtained for CSF2, CXCL1, IL6, and IL8 release. Thus, despite general roles in feedback inhibition, DUSP1 plays a transient, often partial, role in the dexamethasone-dependent repression of certain inflammatory genes. Therefore this also illustrates key roles for DUSP1-independent effectors in mediating glucocorticoid-dependent repression. PMID:24692548

Neurite outgrowth mediated by the heat shock protein Hsp90α: a novel target for the antipsychotic drug aripiprazole

PubMed Central

Ishima, T; Iyo, M; Hashimoto, K

2012-01-01

Aripiprazole is an atypical antipsychotic drug approved for the treatment of psychiatric disorders such as schizophrenia, bipolar disorder, major depressive disorder and autism. The drug shows partial agonistic activity at dopamine D2 receptors and 5-hydroxytryptamine (5-HT) 5-HT1A receptors, and antagonistic activity at 5-HT2A receptors. However, the precise mechanistic pathways remain unclear. In this study, we examined the effects of aripiprazole on neurite outgrowth. Aripiprazole significantly potentiated nerve growth factor (NGF)-induced neurite outgrowth in PC12 cells, in a concentration-dependent manner. The 5-HT1A receptor antagonist WAY-100635, but not the dopamine D2 receptor antagonist sulpiride, blocked the effects of aripiprazole, although, only partially. Specific inhibitors of inositol 1,4,5-triphosphate (IP3) receptors and BAPTA-AM, a chelator of intracellular Ca2+, blocked the effects of aripiprazole. Moreover, specific inhibitors of several common signaling pathways phospholipase C-γ (PLC-γ), phosphatidylinositol-3 kinase (PI3K), mammalian target of rapamycin, p38 MAPK, c-Jun N-terminal kinase, Akt, Ras, Raf, ERK, MAPK) also blocked the effects of aripiprazole. Using proteomic analysis, we found that aripiprazole significantly increased levels of the heat shock protein Hsp90α in cultured cells. The effects of aripiprazole on NGF-induced neurite outgrowth were significantly attenuated by treatment with Hsp90α RNA interference, but not by the negative control of Hsp90α. These findings suggest that both 5-HT1A receptor activation and Ca2+ signaling via IP3 receptors, as well as their downstream cellular signaling pathways play a role in the promotion of aripiprazole-induced neurite outgrowth. Furthermore, aripiprazole-induced increases in Hsp90α protein expression may form part of the therapeutic mechanism for this drug. PMID:23047241

[Study on the role of the tubule in renal vasoconstriction induced by cyclosporine].

PubMed

Camaño Páez, S; Lázaro Fernández, A; Callejas Martínez, R; Lázaro Manero, J A; Castilla Barba, M; Martín-Vasallo, P; Martínez Escandell, A; Tejedor Jorge, A

2008-01-01

Cyclosporine (CyA) has proved to induce cell apoptosis on cultured proximal tubule cells. However, there is no much data about the in vivo functional consequences of this injury or the long time observed CyA-induced renal vasoconstriction. In a swine model of subacute CyA nephrotoxicity (10 mg/ Kg. dx 15 days), we performed a right nephrectomy, followed by left renal artery, vein and ureter catheterisati8n. After inducing water diuresis, three clearance periods of 15 minutes were performed before and after a furosemide 1 mg/kg infusion. Plasma and urine electrolytes, blood gas, acid excretion, plasma renin activity and aldosterone concentration, GFR, RPF, RBF, intra-renal vascular resistances, glomerular filtration pressure, distal Cl- delivery, water clearance and TTKG were measured or estimated on 7 control and 7 treated animals. Right kidney was processed for NaKATPase activity and immunostaining. Treated animals presented detaching proximal cells, luminal blebbing and loss of tight junctions. Cortical but not medullar sodium pump was internalised and partially inactive. Treated animals showed much lower fractional excretions of Na+, with significantly higher distal fractional reabsorption of Cl. Distal shift in fluid load resulted in a significant rise in renal O2 consumption, and modifications in the global renal estequiometry of Na+ transport/O2 uptake. Several consequences followed this situation: preglomerular resistances increased 3 times with only minor changes in postglomerular resistances and renal blood and plasma flow were significantly reduced. Furosemide partially reversed these effects. A slight increase in fractional filtration prevented GFR differences to become statistically significant. subacute CyA treatment even al doses not modifying GFR, may cause proximal tubule Na+ transport impairment, resulting in increased rates of distal delivery and absorption of fluid load. Renal uptake of O2 may be increased and tubule glomerular feedback should be expected to be activated. Absence of changes of GFR with furosemide is an early sign of CyA renal damage.

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

Zhang, Long; Shi, Songting; Zhang, Juan

Highlights: Black-Right-Pointing-Pointer Expression of Id3 but not Id1 is induced by Wnt3a stimulation in C2C12 cells. Black-Right-Pointing-Pointer Wnt3a induces Id3 expression via canonical Wnt/{beta}-catenin pathway. Black-Right-Pointing-Pointer Wnt3a-induced Id3 expression does not depend on BMP signaling activation. Black-Right-Pointing-Pointer Induction of Id3 expression is critical determinant in Wnt3a-induced cell proliferation and differentiation. -- Abstract: Canonical Wnt signaling plays important roles in regulating cell proliferation and differentiation. In this study, we report that inhibitor of differentiation (Id)3 is a Wnt-inducible gene in mouse C2C12 myoblasts. Wnt3a induced Id3 expression in a {beta}-catenin-dependent manner. Bone morphogenetic protein (BMP) also potently induced Id3 expression. However,more » Wnt-induced Id3 expression occurred independent of the BMP/Smad pathway. Functional studies showed that Id3 depletion in C2C12 cells impaired Wnt3a-induced cell proliferation and alkaline phosphatase activity, an early marker of osteoblast cells. Id3 depletion elevated myogenin induction during myogenic differentiation and partially impaired Wnt3a suppressed myogenin expression in C2C12 cells. These results suggest that Id3 is an important Wnt/{beta}-catenin induced gene in myoblast cell fate determination.« less

Endoplasmic reticulum stress-regulated CXCR3 pathway mediates inflammation and neuronal injury in acute glaucoma

PubMed Central

Ha, Y; Liu, H; Xu, Z; Yokota, H; Narayanan, S P; Lemtalsi, T; Smith, S B; Caldwell, R W; Caldwell, R B; Zhang, W

2015-01-01

Acute glaucoma is a leading cause of irreversible blindness in East Asia. The mechanisms underlying retinal neuronal injury induced by a sudden rise in intraocular pressure (IOP) remain obscure. Here we demonstrate that the activation of CXCL10/CXCR3 axis, which mediates the recruitment and activation of inflammatory cells, has a critical role in a mouse model of acute glaucoma. The mRNA and protein expression levels of CXCL10 and CXCR3 were significantly increased after IOP-induced retinal ischemia. Blockade of the CXCR3 pathway by deleting CXCR3 gene significantly attenuated ischemic injury-induced upregulation of inflammatory molecules (interleukin-1β and E-selectin), inhibited the recruitment of microglia/monocyte to the superficial retina, reduced peroxynitrite formation, and prevented the loss of neurons within the ganglion cell layer. In contrast, intravitreal delivery of CXCL10 increased leukocyte recruitment and retinal cell apoptosis. Inhibition of endoplasmic reticulum (ER) stress with chemical chaperones partially blocked ischemic injury-induced CXCL10 upregulation, whereas induction of ER stress with tunicamycin enhanced CXCL10 expression in retina and primary retinal ganglion cells. Interestingly, deleting CXCR3 attenuated ER stress-induced retinal cell death. In conclusion, these results indicate that ER stress-medicated activation of CXCL10/CXCR3 pathway has an important role in retinal inflammation and neuronal injury after high IOP-induced ischemia. PMID:26448323

Gonadal steroids modulate Fas-induced apoptosis of lactotropes and somatotropes.

PubMed

Jaita, Gabriela; Zárate, Sandra; Ferrari, Luciana; Radl, Daniela; Ferraris, Jimena; Eijo, Guadalupe; Zaldivar, Verónica; Pisera, Daniel; Seilicovich, Adriana

2011-02-01

We have previously reported that Fas activation induces apoptosis of anterior pituitary cells from rats at proestrus but not at diestrus and in an estrogen-dependent manner. In this study, we evaluated the effect of Fas activation on apoptosis of lactotropes and somatotropes during the estrous cycle and explored the action of gonadal steroids on Fas-induced apoptosis. Also, we studied whether changes in Fas expression are involved in the apoptotic response of anterior pituitary cells. Fas activation increased the percentage of TUNEL-positive lactotropes and somatotropes at proestrus but not at diestrus. FasL triggered apoptosis of somatotropes only when cells from ovariectomized rats were cultured in the presence of 17 β-estradiol (E2). Progesterone (P4) blocked the apoptotic action of the Fas/FasL system in lactotropes and somatotropes incubated with E2. Both E2 and P4 increased the percentage of cells expressing Fas at the cell membrane. Our results show that Fas activation induces apoptosis of lactotropes and somatotropes at proestrus but not at diestrus. Gonadal steroids may be involved in the apoptotic response of lactotropes and somatotropes, suggesting that Fas activation is implicated in the renewal of these pituitary subpopulations during the estrous cycle. The effect of gonadal steroids on Fas expression may be only partially involved in regulation of the Fas/FasL apoptotic pathway in the anterior pituitary gland.

Norcantharidin Induces Human Melanoma A375-S2 Cell Apoptosis through Mitochondrial and Caspase Pathways

PubMed Central

An, Wei-wei; Wang, Min-wei; Tashiro, Shin-ichi; Onodera, Satoshi

2004-01-01

Norcantharidin (NCTD) is the demethylated form of cantharidin, which is the active substance of mylabris. To examine the pathway of NCTD-induced A375-S2 cell death, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dipheyltetrazolium bromide (MTT) assay, photomicroscopical observation, DNA agarose gel electrophoresis, caspase activity assay and Western blot analysis were carried out. A375-S2 cells treated with NCTD exhibited several typical characteristics of apoptosis. The inhibitory effect of NCTD on human melanoma, A375-S2 cells, was partially reversed by the inhibitors of pan-caspase, caspase-3 and caspase-9. The activities of caspase-3 and -9 were significantly increased after treatment with NCTD at different time. The expression of inhibitor of caspase-activated DNase was decreased in a time-dependent manner, simultaneously, the ratio of Bcl-2/Bax or Bcl-xL/Bax was decreased and the expression ratio of proteins could be reversed by caspase-3 inhibitor. The expression of cytochrome c in cytosol was increased after NCTD treatment and caspase-3 inhibitor had no significant effect on the up-regulation of cytochrom c. These results suggest that NCTD induced A375-S2 cell apoptosis and the activation of caspase and mitochondrial pathway were involved in the process of NCTD-induced A375-S2 cell apoptosis. PMID:15308848

Photobiomodulation partially rescues visual cortical neurons from cyanide-induced apoptosis.

PubMed

Liang, H L; Whelan, H T; Eells, J T; Meng, H; Buchmann, E; Lerch-Gaggl, A; Wong-Riley, M

2006-05-12

Near-infrared light via light-emitting diode treatment has documented therapeutic effects on neurons functionally inactivated by tetrodotoxin or methanol intoxication. Light-emitting diode pretreatment also reduced potassium cyanide-induced cell death, but the mode of death via the apoptotic or necrotic pathway was unclear. The current study tested our hypothesis that light-emitting diode rescues neurons from apoptotic cell death. Primary neuronal cultures from postnatal rat visual cortex were pretreated with light-emitting diode for 10 min at a total energy density of 30 J/cm2 before exposing to potassium cyanide for 28 h. With 100 or 300 microM potassium cyanide, neurons died mainly via the apoptotic pathway, as confirmed by electron microscopy, Hoechst 33258, single-stranded DNA, Bax, and active caspase-3. In the presence of caspase inhibitor I, the percentage of apoptotic cells in 300microM potassium cyanide was significantly decreased. Light-emitting diode pretreatment reduced apoptosis from 36% to 17.9% (100 microM potassium cyanide) and from 58.9% to 39.6% (300 microM potassium cyanide), representing a 50.3% and 32.8% reduction, respectively. Light-emitting diode pretreatment significantly decreased the expression of caspase-3 elicited by potassium cyanide. It also reversed the potassium cyanide-induced increased expression of Bax and decreased expression of Bcl-2 to control levels. Moreover, light-emitting diode decreased the intensity of 5-(and -6) chloromethy-2', 7-dichlorodihydrofluorescein diacetate acetyl ester, a marker of reactive oxygen species, in neurons exposed to 300 microM potassium cyanide. These results indicate that light-emitting diode pretreatment partially protects neurons against cyanide-induced caspase-mediated apoptosis, most likely by decreasing reactive oxygen species production, down-regulating pro-apoptotic proteins and activating anti-apoptotic proteins, as well as increasing energy metabolism in neurons as reported previously.

The Role of Ca2+ Imbalance in the Induction of Acute Oxidative Stress and Cytotoxicity in Cultured Rat Cerebellar Granule Cells Challenged with Tetrabromobisphenol A.

PubMed

Zieminska, Elzbieta; Lenart, Jacek; Diamandakis, Dominik; Lazarewicz, Jerzy W

2017-03-01

Using primary cultures of rat cerebellar granule cells (CGC) we examined the role of calcium transients induced by tetrabromobisphenol A (TBBPA) in triggering oxidative stress and cytotoxicity. CGC were exposed for 30 min to 10 or 25 µM TBBPA. Changes in intracellular calcium concentration ([Ca 2+ ] i ), in the production of reactive oxygen species (ROS), and in the potential of mitochondria (∆Ψm) were measured fluorometrically during the exposure. The intracellular glutathione (GSH) and catalase activity were determined after the incubation; cell viability was evaluated 24 h later. TBBPA concentration-dependently increased [Ca 2+ ] i and ROS production, and reduced GSH content, catalase activity, ∆Ψm and neuronal viability. The combination of NMDA and ryanodine receptor antagonists, MK-801 and bastadin 12 with ryanodine, respectively, prevented Ca 2+ transients and partially reduced cytotoxicity induced by TBBPA at both concentrations. The antagonists also completely inhibited oxidative stress and depolarization of mitochondria evoked by 10 µM TBBPA, whereas these effects were only partially reduced in the 25 µM TBBPA treatment. Free radical scavengers prevented TBBPA-induced development of oxidative stress and improved CGC viability without having any effect on the rises in Ca 2+ and drop in ∆Ψm. The co-administration of scavengers with NMDA and ryanodine receptor antagonists provided almost complete neuroprotection. These results indicate that Ca 2+ imbalance and oxidative stress both mediate acute toxicity of TBBPA in CGC. At 10 µM TBBPA Ca 2+ imbalance is a primary event, inducing oxidative stress, depolarization of mitochondria and cytotoxicity, whilst at a concentration of 25 µM TBBPA an additional Ca 2+ -independent portion of oxidative stress and cytotoxicity emerges.

Dual autonomic inhibitory action of central Apelin on gastric motor functions in rats.

PubMed

Bülbül, Mehmet; Sinen, Osman

2018-07-01

Centrally administered apelin has been shown to inhibit gastric emptying (GE) in rodents, however, the relevant mechanism has been investigated incompletely. Using male Wistar rats, we investigated the efferent pathways involved in gastroinhibitory action of central apelin. Stereotaxic intracerebroventricular (icv) cannulation, subdiaphragmatic vagotomy (VGX) and/or celiac ganglionectomy (CGX) were performed 7 days prior to the experiments. Apelin-13 was administered (30 nmol, icv) 90 min prior to GE measurement. Nitric oxide synthase inhibitor L-NAME (100 mg/kg), sympatholytic agent guanethidine (5 mg/kg) and/or muscarinic receptor agonist bethanechol (1 mg/kg) were administered intraperitoneally 30 min prior to the central apelin-13 injection. Two strain gages were implanted serosally onto antrum and pylorus to monitor gastric postprandial motility. Heart rate variability (HRV) analysis was performed before and after central vehicle or apelin-13 administration. Apelin-13 delayed solid GE significantly by disturbing coordinated antral and pyloric postprandial contractions. The apelin-induced delayed GE was attenuated partially by CGX or VGX, whereas it was restored completely in rats underwent both CGX and VGX. L-NAME did not change the apelin-induced alterations. Guanethidine or bethanechol restored the apelin-induced gastroinhibition partially, while it was abolished completely in rats received both agents. Apelin-13 decreased the HRV spectral activity in high-frequency range by increasing low-frequency component and the ratio of LF:HF. The present data suggest that (1) both vagal parasympathetic and sympathetic pathways play a role in apelin-induced gastroinhibition, (2) central apelin attenuates vagal cholinergic pathway rather than activating nonadrenergic-noncholinergic pathway. Apelin/APJ receptor system might be candidate for the treatment of autonomic dysfunction and gastrointestinal motor disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

Negative feedback regulation of Homer 1a on norepinephrine-dependent cardiac hypertrophy

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

Chiarello, Carmelina; Bortoloso, Elena; Carpi, Andrea

2013-07-15

Homers are scaffolding proteins that modulate diverse cell functions being able to assemble signalling complexes. In this study, the presence, sub-cellular distribution and function of Homer 1 was investigated. Homer 1a and Homer 1b/c are constitutively expressed in cardiac muscle of both mouse and rat and in HL-1 cells, a cardiac cell line. As judged by confocal immunofluorescence microscopy, Homer 1a displays sarcomeric and peri-nuclear localization. In cardiomyocytes and cultured HL-1 cells, the hypertrophic agonist norepinephrine (NE) induces α{sub 1}-adrenergic specific Homer 1a over-expression, with a two-to-three-fold increase within 1 h, and no up-regulation of Homer 1b/c, as judged bymore » Western blot and qPCR. In HL-1 cells, plasmid-driven over-expression of Homer 1a partially antagonizes activation of ERK phosphorylation and ANF up-regulation, two well-established, early markers of hypertrophy. At the morphometric level, NE-induced increase of cell size is likewise and partially counteracted by exogenous Homer 1a. Under the same experimental conditions, Homer 1b/c does not have any effect on ANF up-regulation nor on cell hypertrophy. Thus, Homer 1a up-regulation is associated to early stages of cardiac hypertrophy and appears to play a negative feedback regulation on molecular transducers of hypertrophy. -- Highlights: • Homer 1a is constitutively expressed in cardiac tissue. • In HL-1 cells, norepinephrine activates signaling pathways leading to hypertrophy. • Homer 1a up-regulation is an early event of norepinephrine-induced hypertrophy. • Homer 1a plays a negative feedback regulation modulating pathological hypertrophy. • Over-expression of Homer 1a per se does not induce hypertrophy.« less

A ‘synthetic-sickness’ screen for senescence re-engagement targets in mutant cancer backgrounds

PubMed Central

Godwin, Lauren S.; Bilsland, Alan E.; Stevenson, Katrina H.; Moore, Jon D.; Wiggins, Ceri M.; Collinson, Rebecca S.; Mudd, Clare; Sadaie, Mahito; Bennett, Dorothy C.; Torrance, Christopher J.; Keith, W. Nicol

2017-01-01

Senescence is a universal barrier to immortalisation and tumorigenesis. As such, interest in the use of senescence-induction in a therapeutic context has been gaining momentum in the past few years; however, senescence and immortalisation remain underserved areas for drug discovery owing to a lack of robust senescence inducing agents and an incomplete understanding of the signalling events underlying this complex process. In order to address this issue we undertook a large-scale morphological siRNA screen for inducers of senescence phenotypes in the human melanoma cell line A375P. Following rescreen and validation in a second cancer cell line, HCT116 colorectal carcinoma, a panel of 16 of the most robust hits were selected for further validation based on significance and the potential to be targeted by drug-like molecules. Using secondary assays for detection of senescence biomarkers p21, 53BP1 and senescence associated beta-galactosidase (SAβGal) in a panel of HCT116 cell lines carrying cancer-relevant mutations, we show that partial senescence phenotypes can be induced to varying degrees in a context dependent manner, even in the absence of p21 or p53 expression. However, proliferation arrest varied among genetic backgrounds with predominantly toxic effects in p21 null cells, while cells lacking PI3K mutation failed to arrest. Furthermore, we show that the oncogene ECT2 induces partial senescence phenotypes in all mutant backgrounds tested, demonstrating a dependence on activating KRASG13D for growth suppression and a complete senescence response. These results suggest a potential mechanism to target mutant KRAS signalling through ECT2 in cancers that are reliant on activating KRAS mutations and remain refractory to current treatments. PMID:28806777

Anticonvulsant activity of PNU-151774E in the amygdala kindled model of complex partial seizures.

PubMed

Maj, R; Fariello, R G; Pevarello, P; Varasi, M; McArthur, R A; Salvati, P

1999-11-01

PNU-151774E [(S)-(+)-2-(4-(3-fluorobenzyloxy) benzylamino) propanamide, methanesulfonate] is a novel antiepileptic drug (AED) with a broad spectrum of activity in a variety of chemically and mechanically induced seizures. The objective of this study was to evaluate the activity of PNU-151774E in the amygdala fully kindled rat model of complex partial seizures, and to compare its effects with those of carbamazepine (CBZ), phenytoin (PHT), lamotrigine (LTG), and gabapentin (GBP), drugs used to treat this disease state. Male Wistar rats were stimulated daily through electrodes implanted in the amygdala with a threshold current until fully generalized seizures developed. The rats were then treated with various doses of a single compound. Control values for each rat and drug dose were determined after vehicle administration followed by electrical stimulation 1 day before drug treatment. PNU-151774E (1, 10, 30 mg/kg; i.p.) reduced the duration of behavioral seizures significantly and dose-dependently at doses starting from 1 mg/kg. Higher doses significantly reduced seizure severity and afterdischarge duration. In contrast, no dose-related effects were noted after administration of PHT, whereas after CBZ treatment, a plateau of activity was noted from the intermediate to higher doses. The effects of PNU-151774E were comparable to those of LTG and GBP. The activity shown by PNU-151774E at doses similar to those that are active in models of generalized seizures indicates that PNU-151774E would also have potential efficacy in the treatment of complex partial seizures.

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

Onuma, Hirohisa; Inukai, Kouichi, E-mail: kinukai@ks.kyorin-u.ac.jp; Kitahara, Atsuko

Highlights: • PPARγ activation was involved in the GLP-1-mediated anti-inflammatory action. • Exendin-4 enhanced endogenous PPARγ transcriptional activity in HUVECs. • H89, a PKA inhibitor, abolished GLP-1-induced PPARγ enhancement. • The anti-inflammatory effects of GLP-1 may be explained by PPARγ activation. - Abstract: Recent studies have suggested glucagon-like peptide-1 (GLP-1) signaling to exert anti-inflammatory effects on endothelial cells, although the precise underlying mechanism remains to be elucidated. In the present study, we investigated whether PPARγ activation is involved in the GLP-1-mediated anti-inflammatory action on endothelial cells. When we treated HUVEC cells with 0.2 ng/ml exendin-4, a GLP-1 receptor agonist, endogenousmore » PPARγ transcriptional activity was significantly elevated, by approximately 20%, as compared with control cells. The maximum PPARγ activity enhancing effect of exendin-4 was observed 12 h after the initiation of incubation with exendin-4. As H89, a PKA inhibitor, abolished GLP-1-induced PPARγ enhancement, the signaling downstream from GLP-1 cross-talk must have been involved in PPARγ activation. In conclusion, our results suggest that GLP-1 has the potential to induce PPARγ activity, partially explaining the anti-inflammatory effects of GLP-1 on endothelial cells. Cross-talk between GLP-1 signaling and PPARγ activation would have major impacts on treatments for patients at high risk for cardiovascular disease.« less

Involvement of μ-opioid receptors in antinociceptive action of botulinum toxin type A.

PubMed

Drinovac, V; Bach-Rojecky, L; Matak, I; Lacković, Z

2013-07-01

Botulinum toxin A (BTX-A) is approved for treatment of chronic migraine and has been investigated in various other painful conditions. Recent evidence demonstrated retrograde axonal transport and suggested the involvement of CNS in antinociceptive effect of BTX-A. However, the mechanism of BTX-A central antinociceptive action is unknown. In this study we investigated the potential role of opioid receptors in BTX-A's antinociceptive activity. In formalin-induced inflammatory pain we assessed the effect of opioid antagonists on antinociceptive activity of BTX-A. Naltrexone was injected subcutaneously (0.02-2 mg/kg) or intrathecally (0.07 μg/10 μl-350 μg/10 μl), while selective μ-antagonist naloxonazine was administered intraperitoneally (5 mg/kg) prior to nociceptive testing. The influence of naltrexone (2 mg/kg s.c.) on BTX-A antinociceptive activity was examined additionally in an experimental neuropathy induced by partial sciatic nerve transection. To investigate the effects of naltrexone and BTX-A on neuronal activation in spinal cord, c-Fos expression was immunohistochemically examined in a model of formalin-induced pain. Antinociceptive effects of BTX-A in formalin and sciatic nerve transection-induced pain were prevented by non-selective opioid antagonist naltrexone. Similarly, BTX-A-induced pain reduction was abolished by low dose of intrathecal naltrexone and by selective μ-antagonist naloxonazine. BTX-A-induced decrease in dorsal horn c-Fos expression was prevented by naltrexone. Prevention of BTX-A effects on pain and c-Fos expression by opioid antagonists suggest that the central antinociceptive action of BTX-A might be associated with the activity of endogenous opioid system (involving μ-opioid receptor). These results provide first insights into the mechanism of BTX-A's central antinociceptive activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

p38 mitogen-activated protein kinase mediates IL-8 induction by the ribotoxin deoxynivalenol in human monocytes

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

Islam, Zahidul; Center for Integrative Toxicology, Michigan State University, 234 G.M. Trout Building, Michigan State University, East Lansing, MI 48824-1224; Gray, Jennifer S.

2006-06-15

The effects of the ribotoxic trichothecene deoxynivalenol (DON) on mitogen-activated protein kinase (MAPK)-mediated IL-8 expression were investigated in cloned human monocytes and peripheral blood mononuclear cells (PBMC). DON (250 to 1000 ng/ml) induced both IL-8 mRNA and IL-8 heteronuclear RNA (hnRNA), an indicator of IL-8 transcription, in the human U937 monocytic cell line in a concentration-dependent manner. Expression of IL-8 hnRNA, mRNA and protein correlated with p38 phosphorylation and was completely abrogated by the p38 MAPK inhibitor SB203580. DON at 500 ng/ml similarly induced p38-dependent IL-8 protein and mRNA expression in PBMC cultures from healthy volunteers. Significantly increased IL-6 andmore » IL-1{beta} intracellular protein and mRNA expression was also observed in PBMC treated with DON (500 ng/ml) which were also partially p38-dependent. Flow cytometry of PBMC revealed that DON-induced p38 phosphorylation varied among individuals relative to both threshold toxin concentrations (25-100 ng/ml) and relative increases in percentages of phospho-p38{sup +} cells. DON-induced p38 activation occurred exclusively in the CD14{sup +} monocyte population. DON was devoid of agonist activity for human Toll-like receptors 2, 3, 4, 5, 7, 8 and 9. However, two other ribotoxins, emetine and anisomycin, induced p38 phosphorylation in PBMC similarly to DON. Taken together, these data suggest that (1) p38 activation was required for induction of IL-8 and proinflammatory gene expression in the monocyte and (2) DON induced p38 activation in human monocytes via the ribotoxic stress response.« less

Anticoagulant and Antiplatelet Activities of Artemisia princeps Pampanini and Its Bioactive Components.

PubMed

Ryu, Ri; Jung, Un Ju; Kim, Hye-Jin; Lee, Wonhwa; Bae, Jong-Sup; Park, Yong Bok; Choi, Myung-Sook

2013-09-01

Artemisia princeps Pampanini (AP) has been used as a traditional medicine in Korea, China and Japan and reported to exhibit various beneficial biological effects including anti-inflammatory, antioxidant, anti-atherogenic and lipid lowering activities; however, its antiplatelet and anticoagulant properties have not been studied. In the present study, we evaluated the effects of an ethanol extract of Artemisia princeps Pampanini (EAP) and its major flavonoids, eupatilin and jaceosidin, on platelet aggregation and coagulation. To determine the antiplatelet activity, arachidonic acid (AA)-, collagen- and ADP (adenosine diphosphate)-induced platelet aggregation were examined along with serotonin and thromboxane A2 (TXA2) generation in vitro. The anticoagulant activity was determined by monitoring the activated partial thromboplastin time (aPTT) and prothrombin time (PT) in vitro. The data showed that EAP and its major flavonoids, eupatilin and jaceosidin, significantly reduced AA-induced platelet aggregation and the generation of serotonin and TXA2, although no significant change in platelet aggregation induced by collagen and ADP was observed. Moreover, EAP significantly prolonged the PT and aPTT. The PT and/or aPTT were significantly increased in the presence of eupatilin and jaceosidin. Thus, these results suggest that EAP may have the potential to prevent or improve thrombosis by inhibiting platelet activation and blood coagulation.

Anticoagulant and Antiplatelet Activities of Artemisia princeps Pampanini and Its Bioactive Components

PubMed Central

Ryu, Ri; Jung, Un Ju; Kim, Hye-jin; Lee, Wonhwa; Bae, Jong-Sup; Park, Yong Bok; Choi, Myung-Sook

2013-01-01

Artemisia princeps Pampanini (AP) has been used as a traditional medicine in Korea, China and Japan and reported to exhibit various beneficial biological effects including anti-inflammatory, antioxidant, anti-atherogenic and lipid lowering activities; however, its antiplatelet and anticoagulant properties have not been studied. In the present study, we evaluated the effects of an ethanol extract of Artemisia princeps Pampanini (EAP) and its major flavonoids, eupatilin and jaceosidin, on platelet aggregation and coagulation. To determine the antiplatelet activity, arachidonic acid (AA)-, collagen- and ADP (adenosine diphosphate)-induced platelet aggregation were examined along with serotonin and thromboxane A2 (TXA2) generation in vitro. The anticoagulant activity was determined by monitoring the activated partial thromboplastin time (aPTT) and prothrombin time (PT) in vitro. The data showed that EAP and its major flavonoids, eupatilin and jaceosidin, significantly reduced AA-induced platelet aggregation and the generation of serotonin and TXA2, although no significant change in platelet aggregation induced by collagen and ADP was observed. Moreover, EAP significantly prolonged the PT and aPTT. The PT and/or aPTT were significantly increased in the presence of eupatilin and jaceosidin. Thus, these results suggest that EAP may have the potential to prevent or improve thrombosis by inhibiting platelet activation and blood coagulation. PMID:24471130

Green laser light activates the inner ear

NASA Astrophysics Data System (ADS)

Wenzel, Gentiana I.; Balster, Sven; Zhang, Kaiyin; Lim, Hubert H.; Reich, Uta; Massow, Ole; Lubatschowski, Holger; Ertmer, Wolfgang; Lenarz, Thomas; Reuter, Guenter

2009-07-01

The hearing performance with conventional hearing aids and cochlear implants is dramatically reduced in noisy environments and for sounds more complex than speech (e. g. music), partially due to the lack of localized sensorineural activation across different frequency regions with these devices. Laser light can be focused in a controlled manner and may provide more localized activation of the inner ear, the cochlea. We sought to assess whether visible light with parameters that could induce an optoacoustic effect (532 nm, 10-ns pulses) would activate the cochlea. Auditory brainstem responses (ABRs) were recorded preoperatively in anesthetized guinea pigs to confirm normal hearing. After opening the bulla, a 50-μm core-diameter optical fiber was positioned in the round window niche and directed toward the basilar membrane. Optically induced ABRs (OABRs), similar in shape to those of acoustic stimulation, were elicited with single pulses. The OABR peaks increased with energy level (0.6 to 23 μJ/pulse) and remained consistent even after 30 minutes of continuous stimulation at 13 μJ, indicating minimal or no stimulation-induced damage within the cochlea. Our findings demonstrate that visible light can effectively and reliably activate the cochlea without any apparent damage. Further studies are in progress to investigate the frequency-specific nature and mechanism of green light cochlear activation.

Protective effects of total saponins from stem and leaf of Panax ginseng against cyclophosphamide-induced genotoxicity and apoptosis in mouse bone marrow cells and peripheral lymphocyte cells.

PubMed

Zhang, Qiu Hua; Wu, Chun Fu; Duan, Lian; Yang, Jing Yu

2008-01-01

Cyclophosphamide (CP), commonly used anti-cancer, induces oxidative stress and is cytotoxic to normal cells. It is very important to choice the protective agent combined CP to reduce the side effects in cancer treatment. Ginsenosides are biological active constituents of Panax ginseng C.A. Meyer that acts as the tonic agent for the cancer patients to reduce the side effects in the clinic application. Because CP is a pro-oxidant agent and induces oxidative stress by the generation of free radicals to decrease the activities of anti-oxidant enzymes, the protective effects of the total saponins from stem and leaf of P. ginseng C.A. Meyer (TSPG) act as an anti-oxidant agent against the decreased anti-oxidant enzymes, the genotoxicity and apoptosis induced by CP was carried out. The alkaline single cell gel electrophoresis was employed to detect DNA damage; flow cytometry assay and AO/EB staining assay were employed to measure cell apoptosis; the enzymatic anti-oxidants (T-SOD, CAT and GPx) and non-enzymatic anti-oxidant (GSH) were measured by the various colorimetric methods. CP induced the significant DNA damage in mouse peripheral lymphocytes in time- and dose-dependent manners, inhibited the activities of T-SOD, GPx and CAT, and decreased the contents of GSH in mouse blood, triggered bone marrow cell apoptosis at 6 and 12h. TSPG significantly reduced CP-induced DNA damages in bone marrow cells and peripheral lymphocyte cells, antagonized CP-induced reduction of T-SOD, GPx, CAT activities and the GSH contents, decreased the bone marrow cell apoptosis induced by CP. TSPG, significantly reduced the genotoxicity of CP in bone marrow cells and peripheral lymphocyte cells, and decreased the apoptotic cell number induced by CP in bone marrow cells. The effects of TSPG on T-SOD, GPx, CAT activities and GSH contents might partially contribute to its protective effects on CP-induced cell toxicities.

iNKT-CELL ACTIVATION INDUCES LATE PRETERM BIRTH THAT IS ATTENUATED BY ROSIGLITAZONE1

PubMed Central

St Louis, Derek; Romero, Roberto; Plazyo, Olesya; Arenas-Hernandez, Marcia; Panaitescu, Bogdan; Xu, Yi; Milovic, Tatjana; Xu, Zhonghui; Bhatti, Gaurav; Qing-Sheng, Mi; Drewlo, Sascha; Tarca, Adi L.; Hassan, Sonia S.; Gomez-Lopez, Nardhy

2015-01-01

Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality; however, its non-infection-related mechanisms are poorly understood. Herein, we show that the expansion of activated CD1d-restricted invariant NKT (iNKT) cells in the third trimester by administration of α-galactosylceramide (α-GalCer) induces late PTB and neonatal mortality. In vivo imaging revealed that fetuses from mice that underwent α-GalCer-induced late PTB had bradycardia and died shortly after delivery. Yet, administration of α-GalCer in the second trimester did not cause pregnancy loss. PPARγ activation, through rosiglitazone treatment, reduced the rate of α-GalCer-induced late PTB and improved neonatal survival. Administration of α-GalCer in the third trimester suppressed PPARγ activation as shown by the down-regulation of Fabp4 and Fatp4 in myometrial and decidual tissues, respectively; this suppression was rescued by rosiglitazone treatment. Administration of α-GalCer in the third trimester induced an increase in the activation of conventional CD4+ T cells in myometrial tissues and the infiltration of activated macrophages, neutrophils and mature DCs to myometrial and/or decidual tissues. All of these effects were blunted after rosiglitazone treatment. Administration of α-GalCer also up-regulated the expression of inflammatory genes at the maternal-fetal interface and systemically, and rosiglitazone treatment partially attenuated these responses. Finally, an increased infiltration of activated iNKT-like cells in human decidual tissues is associated with non-infection-related preterm labor/birth. Collectively, these results demonstrate that iNKT-cell activation in vivo leads to late PTB by initiating innate and adaptive immune responses and suggest that the PPARγ pathway has potential as a target for prevention of this syndrome. PMID:26740111

Activating PXR by Imperatorin Attenuates Dextran Sulphate Sodium-Induced Colitis in Mice.

PubMed

Liu, Meijing; Zhang, Guohui; Zheng, Chunge; Song, Meng; Liu, Fangle; Huang, Xiaotao; Bai, Shasha; Huang, Xinan; Lin, Chaozhan; Zhu, Chenchen; Hu, Yingjie; Mi, Suiqing; Liu, Changhui

2018-06-26

The activation of human pregnane X receptor (PXR) has potential therapeutic uses for inflammatory bowel disease (IBD). Imperatorin (IMP), a naturally-occurring coumarin, is the main bioactive ingredient of Angelica dahurica Radix, which is regularly used to treat the common cold and intestinal disorders. However, there are no data on the protective effects of IMP against IBD. The effects of IMP on PXR-modulated cytochrome P450 3A4 (CYP3A4) expression were assessed using a PXR transactivation assay, a mammalian two-hybrid assay, a competitive ligand-binding assay, analysis of CYP3A4 mRNA and protein expression levels, and measurement of CYP3A4 activity using a cell-based reporter gene assay and in vitro model. The inhibitory effects of IMP on NF-κB activity was evaluated by a reporter assay and NF-κB p65 nuclear translocation. The anti-IBD effects of IMP were investigated in a dextran sulphate sodium (DSS)-induced colitis mouse model. Colon inflammatory cytokines were assessed by ELISA. IMP activated CYP3A4 promoter activity, recruited steroid receptor coactivator 1 (SRC-1) to the ligand-binding domain of PXR, and increased the expression and activity of CYP3A4. However, PXR knockdown substantially reduced PXR-mediated CYP3A4 expression. Furthermore, IMP-mediated PXR activation suppressed NF-κB nuclear translocation and downregulated lipopolysaccharide-induced proinflammatory gene expression. Nevertheless, PXR knockdown partially reduced the IMP-mediated inhibition of NF-κB. IMP ameliorated DSS-induced colitis by PXR/NF-κB signalling. IMP serves as a PXR agonist to attenuate DSS-induced colitis by the suppression of the NF-κB-mediated proinflammatory response in a PXR/NF-κB- dependent manner. This article is protected by copyright. All rights reserved.

Neurotrophin Promotes Neurite Outgrowth by Inhibiting Rif GTPase Activation Downstream of MAPKs and PI3K Signaling

PubMed Central

Tian, Xiaoxia; Yan, Huijuan; Li, Jiayi; Wu, Shuang; Wang, Junyu; Fan, Lifei

2017-01-01

Members of the well-known semaphorin family of proteins can induce both repulsive and attractive signaling in neural network formation and their cytoskeletal effects are mediated in part by small guanosine 5’-triphosphatase (GTPases). The aim of this study was to investigate the cellular role of Rif GTPase in the neurotrophin-induced neurite outgrowth. By using PC12 cells which are known to cease dividing and begin to show neurite outgrowth responding to nerve growth factor (NGF), we found that semaphorin 6A was as effective as nerve growth factor at stimulating neurite outgrowth in PC12 cells, and that its neurotrophic effect was transmitted through signaling by mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3-kinase (PI3K). We further found that neurotrophin-induced neurite formation in PC12 cells could be partially mediated by inhibition of Rif GTPase activity downstream of MAPKs and PI3K signaling. In conclusion, we newly identified Rif as a regulator of the cytoskeletal rearrangement mediated by semaphorins. PMID:28098758

The α-Secretase-derived N-terminal Product of Cellular Prion, N1, Displays Neuroprotective Function in Vitro and in Vivo*

PubMed Central

Guillot-Sestier, Marie-Victoire; Sunyach, Claire; Druon, Charlotte; Scarzello, Sabine; Checler, Frédéric

2009-01-01

Cellular prion protein (PrPc) undergoes a disintegrin-mediated physiological cleavage, generating a soluble amino-terminal fragment (N1), the function of which remained unknown. Recombinant N1 inhibits staurosporine-induced caspase-3 activation by modulating p53 transcription and activity, whereas the PrPc-derived pathological fragment (N2) remains biologically inert. Furthermore, N1 protects retinal ganglion cells from hypoxia-induced apoptosis, reduces the number of terminal deoxynucleotidyltransferase-mediated biotinylated UTP nick end labeling-positive and p53-immunoreactive neurons in a pressure-induced ischemia model of the rat retina and triggers a partial recovery of b-waves but not a-waves of rat electroretinograms. Our work is the first demonstration that the α-secretase-derived PrPc fragment N1, but not N2, displays in vivo and in vitro neuroprotective function by modulating p53 pathway. It further demonstrates that distinct N-terminal cleavage products of PrPc harbor different biological activities underlying the various phenotypes linking PrPc to cell survival. PMID:19850936

Zinc can increase the activity of protein kinase C and contributes to its binding to plasma membranes in T lymphocytes.

PubMed

Csermely, P; Szamel, M; Resch, K; Somogyi, J

1988-05-15

In the primary structure of protein kinase C, the presence of a putative metal-binding site has been suggested (Parker, P.J., Coussens, L., Totty, N., Rhee, L., Young, S., Chen, E., Stabel, S., Waterfield, M.D., and Ullrich, A. (1986) Science 233, 853-859). In the present report, we demonstrate that the most abundant intracellular heavy metal, zinc, can increase the activity of cytosolic protein kinase C. Zinc reversibly binds the enzyme to plasma membranes, and it may contribute to the calcium-induced binding as well. The intracellular heavy metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine prevents the phorbol ester- and antigen-induced translocation of protein kinase C. This effect can be totally reversed by the concomitant addition of Zn2+, while Fe2+ and Mn2+ are only partially counteractive. Our results suggest that zinc can activate protein kinase C and contributes to its binding to plasma membranes in T lymphocytes induced by Ca2+, phorbol ester, or antigen.

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

Lu, Jun; Byrne, Noel; Wang, John

Clinical studies indicate that partial agonists of the G-protein-coupled, free fatty acid receptor 1 GPR40 enhance glucose-dependent insulin secretion and represent a potential mechanism for the treatment of type 2 diabetes mellitus. Full allosteric agonists (AgoPAMs) of GPR40 bind to a site distinct from partial agonists and can provide additional efficacy. We report the 3.2-Å crystal structure of human GPR40 (hGPR40) in complex with both the partial agonist MK-8666 and an AgoPAM, which exposes a novel lipid-facing AgoPAM-binding pocket outside the transmembrane helical bundle. Comparison with an additional 2.2-Å structure of the hGPR40–MK-8666 binary complex reveals an induced-fit conformational couplingmore » between the partial agonist and AgoPAM binding sites, involving rearrangements of the transmembrane helices 4 and 5 (TM4 and TM5) and transition of the intracellular loop 2 (ICL2) into a short helix. These conformational changes likely prime GPR40 to a more active-like state and explain the binding cooperativity between these ligands.« less

Dissecting the Molecular Mechanism of Ionizing Radiation-Induced Tissue Damage in the Feather Follicle

PubMed Central

Chen, Xi; Liao, Chunyan; Chu, Qiqi; Zhou, Guixuan; Lin, Xiang; Li, Xiaobo; Lu, Haijie; Xu, Benhua; Yue, Zhicao

2014-01-01

Ionizing radiation (IR) is a common therapeutic agent in cancer therapy. It damages normal tissue and causes side effects including dermatitis and mucositis. Here we use the feather follicle as a model to investigate the mechanism of IR-induced tissue damage, because any perturbation of feather growth will be clearly recorded in its regular yet complex morphology. We find that IR induces defects in feather formation in a dose-dependent manner. No abnormality was observed at 5 Gy. A transient, reversible perturbation of feather growth was induced at 10 Gy, leading to defects in the feather structure. This perturbation became irreversible at 20 Gy. Molecular and cellular analysis revealed P53 activation, DNA damage and repair, cell cycle arrest and apoptosis in the pathobiology. IR also induces patterning defects in feather formation, with disrupted branching morphogenesis. This perturbation is mediated by cytokine production and Stat1 activation, as manipulation of cytokine levels or ectopic Stat1 over-expression also led to irregular feather branching. Furthermore, AG-490, a chemical inhibitor of Stat1 signaling, can partially rescue IR-induced tissue damage. Our results suggest that the feather follicle could serve as a useful model to address the in vivo impact of the many mechanisms of IR-induced tissue damage. PMID:24586618

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

Marfa-Riera, V.; Gollin, D.; Mohnen, D.

An optimized tobacco thin-cell-layer (TCL) bioassay was used to study the induction of flowers by plant oligosaccharins. Endopolygalacturonase (EPG)-released fragments of suspension-cultured sycamore cell walls induced flowers on TCLs grown on a medium containing 1.5 {mu}M IBA and 0.9 {mu}M kinetin. The EPG-released fragments were primarily composed of the polysaccharides rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II), and {alpha}-1,4-linked oligogalacturonides. The {alpha}-1,4-linked oligogalacturonides, subsequently purified from the EPG-released sycamore cell wall fragment mixture, induced flowers on TCLs. Purified RG-I and RG-II did not induce flowers. Oligosaccharide fragments, generated by partial acid hydrolysis of citrus pectin, were also capable of inducing flowersmore » on the TCLs. The active components in the pectin fragment mixture were {alpha}-1,4-linked oligogalacturonides. Oligogalacturonides with a degree of polymerization (DP) of 8-16, at concentrations of {approx} 0.1 {mu}M, induced flowers, while oligogalacturonides with a DP 2-7, even at higher concentrations, did not. Oligogalacturonides have previously been shown to induce the synthesis of phytoalexins, protease inhibitors, lignin, and ethylene in other plant systems. Thus, the ability of {alpha}-1,4-linked oligogalacturonides to induce flower formation in the tobacco TCLs represents a new biological activity of these oligosaccharins.« less

Metformin prevents endoplasmic reticulum stress-induced apoptosis through AMPK-PI3K-c-Jun NH2 pathway

USGS Publications Warehouse

Jung, T.W.; Lee, M.W.; Lee, Y.-J.; Kim, S.M.

2012-01-01

Type 2 diabetes mellitus is thought to be partially associated with endoplasmic reticulum (ER) stress toxicity on pancreatic beta cells and the result of decreased insulin synthesis and secretion. In this study, we showed that a well-known insulin sensitizer, metformin, directly protects against dysfunction and death of ER stress-induced NIT-1 cells (a mouse pancreatic beta cell line) via AMP-activated protein kinase (AMPK) and phosphatidylinositol-3 (PI3) kinase activation. We also showed that exposure of NIT-1 cells to metformin (5mM) increases cellular resistance against ER stress-induced NIT-1 cell dysfunction and death. AMPK and PI3 kinase inhibitors abolished the effect of metformin on cell function and death. Metformin-mediated protective effects on ER stress-induced apoptosis were not a result of an unfolded protein response or the induced inhibitors of apoptotic proteins. In addition, we showed that exposure of ER stressed-induced NIT-1 cells to metformin decreases the phosphorylation of c-Jun NH(2) terminal kinase (JNK). These data suggest that metformin is an important determinant of ER stress-induced apoptosis in NIT-1 cells and may have implications for ER stress-mediated pancreatic beta cell destruction via regulation of the AMPK-PI3 kinase-JNK pathway.

The role of hypoxia and HIF1α in the regulation of STAR-mediated steroidogenesis in granulosa cells.

PubMed

Kowalewski, Mariusz Pawel; Gram, Aykut; Boos, Alois

2015-02-05

The adaptive responses to hypoxia are mediated by hypoxia-inducible factor 1 alpha (HIF1α). Its role, however, in regulating steroidogenesis remains poorly understood. We examined the role of hypoxia and HIF1α in regulating steroid acute regulatory protein (STAR) expression and steroidogenesis in immortalized (KK1) mouse granulosa cells under progressively lowering O2 concentrations (20%, 15%, 10%, 5%, 1%). Basal and dbcAMP-stimulated progesterone synthesis was decreased under severe hypoxia (1% and 5% O2). The partial hypoxia revealed opposing effects, with a significant increase in steroidogenic response at 10% O2 in dbcAMP-treated cells: Star-promoter activity, mRNA and protein expression were increased. The hypoxia-stimulated STAR expression was PKA-dependent. Binding of HIF1α to the Star-promoter was potentiated under partial hypoxia. Inhibition of the transcriptional activity or expression of HIF1α suppressed STAR-expression. HIF1α appears to be a positive regulator of basal and stimulated STAR-expression, which under partial hypoxia is capable of increasing the steroidogenic capacity of granulosa cells. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Subpopulation of store-operated Ca2+ channels regulate Ca2+-induced Ca2+ release in non-excitable cells.

PubMed

Yao, Jian; Li, Qin; Chen, Jin; Muallem, Shmuel

2004-05-14

Ca2+-induced Ca2+ release (CICR) is a well characterized activity in skeletal and cardiac muscles mediated by the ryanodine receptors. The present study demonstrates CICR in the non-excitable parotid acinar cells, which resembles the mechanism described in cardiac myocytes. Partial depletion of internal Ca2+ stores leads to a minimal activation of Ca2+ influx. Ca2+ influx through this pathway results in an explosive mobilization of Ca2+ from the majority of the stores by CICR. Thus, stimulation of parotid acinar cells in Ca2+ -free medium with 0.5 microm carbachol releases approximately 5% of the Ca2+ mobilizable by 1 mm carbachol. Addition of external Ca2+ induced the same Ca2+ release observed in maximally stimulated cells. Similar results were obtained by a short treatment with 2.5-10 microm cyclopiazonic acid, an inhibitor of the sarco/endoplasmic reticulum Ca2+ ATPase pump. The Ca2+ release induced by the addition of external Ca2+ was largely independent of IP(3)Rs because it was reduced by only approximately 30% by the inhibition of the inositol 1,4,5-trisphosphate receptors with caffeine or heparin. Measurements of Ca2+ -activated outward current and [Ca2+](i) suggested that most CICR triggered by Ca2+ influx occurred away from the plasma membrane. Measurement of the response to several concentrations of cyclopiazonic acid revealed that Ca2+ influx that regulates CICR is associated with a selective portion of the internal Ca2+ pool. The minimal activation of Ca2+ influx by partial store depletion was confirmed by the measurement of Mn2+ influx. Inhibition of Ca2+ influx with SKF96365 or 2-aminoethoxydiphenyl borate prevented activation of CICR observed on addition of external Ca2+. These findings provide evidence for activation of CICR by Ca2+ influx in non-excitable cells, demonstrate a previously unrecognized role for Ca2+ influx in triggering CICR, and indicate that CICR in non-excitable cells resembles CICR in cardiac myocytes with the exception that in cardiac cells Ca2+ influx is mediated by voltage-regulated Ca2+ channels whereas in non-excitable cells Ca2+ influx is mediated by store-operated channels.

2',5'-Dihydroxychalcone-induced glutathione is mediated by oxidative stress and kinase signaling pathways.

PubMed

Kachadourian, Remy; Pugazhenthi, Subbiah; Velmurugan, Kalpana; Backos, Donald S; Franklin, Christopher C; McCord, Joe M; Day, Brian J

2011-09-15

Hydroxychalcones are naturally occurring compounds that continue to attract considerable interest because of their anti-inflammatory and antiangiogenic properties. They have been reported to inhibit the synthesis of the inducible nitric oxide synthase and to induce the expression of heme oxygenase-1. This study examines the mechanisms by which 2',5'-dihydroxychalcone (2',5'-DHC) induces an increase in cellular glutathione (GSH) levels using a cell line stably expressing a luciferase reporter gene driven by antioxidant-response elements (MCF-7/AREc32). The 2',5'-DHC-induced increase in cellular GSH levels was partially inhibited by the catalytic antioxidant MnTDE-1,3-IP(5+), suggesting that reactive oxygen species (ROS) mediate the antioxidant adaptive response. 2',5'-DHC treatment induced phosphorylation of the c-Jun N-terminal kinase (JNK) pathway, which was also inhibited by MnTDE-1,3-IP(5+). These findings suggest a ROS-dependent activation of the AP-1 transcriptional response. However, whereas 2',5'-DHC triggered the NF-E2-related factor 2 (Nrf2) transcriptional response, cotreatment with MnTDE-1,3-IP(5+) did not decrease 2',5'-DHC-induced Nrf2/ARE activity, showing that this pathway is not dependent on ROS. Moreover, pharmacological inhibitors of mitogen-activated protein kinase (MAPK) pathways showed a role for JNK and p38MAPK in mediating the 2',5'-DHC-induced Nrf2 response. These findings suggest that the 2',5'-DHC-induced increase in GSH levels results from a combination of ROS-dependent and ROS-independent pathways. Copyright © 2011 Elsevier Inc. All rights reserved.

Bioactivity-guided fractionation for anti-inflammatory and analgesic properties and constituents of Xanthium strumarium L.

PubMed

Han, T; Li, H-L; Zhang, Q-Y; Han, P; Zheng, H-C; Rahman, K; Qin, L-P

2007-12-01

The aim of this study was to fractionate an extract of Xanthium strumarium L. (EXS) and to investigate the anti-inflammatory and analgesic properties of the extract and its fractions. The ethanol extract of X. strumarium (EXS) was fractionated on the basis of polarity. Among the different fractions, the n-butanol fraction showed the highest anti-inflammatory activity in the croton-oil-induced ear edema test and furthermore reduced the number of writhings induced by acetic acid in mice in a dose-dependent manner. This indicates that the n-butanol fraction of X. strumarium possesses potent analgesic effects which are likely to be mediated by its anti-inflammatory activity. Bioassay-guided fractionation of EXS led to the isolation and identification of ten caffeoylquinic acids and three heterocyclics by HPLC-DAD-MS(n) from the active n-butanol fraction, implying that the active compounds are polar in nature. The isolated caffeoylquinic acids could partially explain the antinociceptive effect of X. strumarium polar extract.

Effects of Ursodeoxycholic Acid and Insulin on Palmitate-Induced ROS Production and Down-Regulation of PI3K/Akt Signaling Activity.

PubMed

Yokoyama, Kunihiro; Tatsumi, Yasuaki; Hayashi, Kazuhiko; Goto, Hidemi; Ishikawa, Tetsuya; Wakusawa, Shinya

2017-01-01

In obese and diabetic patients, plasma free fatty acid (FFA) levels are often elevated and may play a causal role in insulin resistance and reactive oxygen species (ROS) production. We have previously shown that ursodeoxycholic acid (UDCA) has antioxidative activity through the phosphatidylinositol 3-kinase (PI3K)/Akt signaling-mediated glutathione production. In this study, we investigated the effects of UDCA on insulin response by analyzing intracellular ROS and the activation of the PI3K/Akt signaling pathway in HepG2 cells treated with palmitate. The level of ROS was quantified using 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCFDA), and the activation of the PI3K/Akt signaling pathway was determined by Western blotting assay using appropriate antibodies. The intracellular ROS levels were increased by palmitate but were reduced by treatment with UDCA and insulin. Furthermore, insulin significantly stimulated the phosphorylation of Akt. When the cells were pre-treated with palmitate, insulin-induced Akt-phosphorylation was markedly inhibited. However, when the cells were treated with palmitate and UDCA, the effects of insulin were partially restored. UDCA may have protective effects against palmitate-induced decreases in responsiveness to insulin.

White Tea Extract Induces Apoptosis in Nonsmall Cell Lung Cancer Cells– The Role of PPAR-γ and 15-Lipoxygenases

PubMed Central

Mao, Jenny T.; Nie, Wen-Xian; Tsu, I-Hsien; Jin, Yu-Sheng; Rao, Jian yu; Lu, Qing-Yi; Zhang, Zuo-Feng; Go, Vay Liang W.; Serio, Kenneth J.

2010-01-01

Purpose Emerging preclinical data suggests that tea possess anticarcinogenic and antimutagenic properties. We therefore hypothesize that white tea extract (WTE) is capable of favorably modulating apoptosis, a mechanism associated with lung tumorigenesis. Experimental Design We examined the effects of physiologically relevant doses of WTE on the induction of apoptosis in the nonsmall cell lung cancer (NSCLC) cell lines, A549 (adenocarcinoma) and H520 (squamous cell carcinoma) cells. We further characterized the molecular mechanisms responsible for the WTE-induced apoptosis, including the induction of PPAR-γ and the 15-lipoxygenase (15-LOX) signaling pathway. Results We found that WTE was effective in inducing apoptosis in both A549 and H520 cells, and inhibition of PPAR-γ with GW 9662 partially reversed the WTE-induced apoptosis. We further demonstrate that WTE increased PPAR-γ activation and mRNA expression, concomitantly increased 15-HETE release, and up-regulated 15-LOX-1 and 2 mRNA expression by A549 cells. Inhibition of 15-LOX with NGDA, as well as caffeic acid, abrogated the WTE-induced PPAR-γ activation and up-regulation of PPAR-γ mRNA expression in A549 cells. WTE also induced cyclin-dependent kinase inhibitor 1A (CDKN1A) mRNA expression and activated caspase 3. Inhibition of caspase 3 abrogated the WTE-induced apoptosis. Conclusions Our findings indicate that WTE is capable of inducing apoptosis in NSCLC cell lines. The induction of apoptosis appears to be mediated, in part, through the up-regulation of the PPAR-γ and 15-LOX signaling pathways, with enhanced activation of caspase 3. Our findings support the future investigation of WTE as an antineoplastic and chemopreventive agent for lung cancer. PMID:20668019

Apoptotic Cell Death Induced by Resveratrol Is Partially Mediated by the Autophagy Pathway in Human Ovarian Cancer Cells

PubMed Central

Lang, Fangfang; Qin, Zhaoyang; Li, Fang; Zhang, Huilin; Fang, Zhenghui; Hao, Enkui

2015-01-01

Resveratrol (trans-3,4,5’ –trihydroxystilbene) is an active compound in food, such as red grapes, peanuts, and berries. Resveratrol exhibits an anticancer effect on various human cancer cells. However, the mechanism of resveratrol-induced anti-cancer effect at the molecular level remains to be elucidated. In this study, the mechanism underlying the anti-cancer effect of resveratrol in human ovarian cancer cells (OVCAR-3 and Caov-3) was investigated using various molecular biology techniques, such as flow cytometry, western blotting, and RNA interference, with a major focus on the potential role of autophagy in resveratrol-induced apoptotic cell death. We demonstrated that resveratrol induced reactive oxygen species (ROS) generation, which triggers autophagy and subsequent apoptotic cell death. Resveratrol induced ATG5 expression and promoted LC3 cleavage. The apoptotic cell death induced by resveratrol was attenuated by both pharmacological and genetic inhibition of autophagy. The autophagy inhibitor chloroquine, which functions at the late stage of autophagy, significantly reduced resveratrol-induced cell death and caspase 3 activity in human ovarian cancer cells. We also demonstrated that targeting ATG5 by siRNA also suppressed resveratrol-induced apoptotic cell death. Thus, we concluded that a common pathway between autophagy and apoptosis exists in resveratrol-induced cell death in OVCAR-3 human ovarian cancer cells. PMID:26067645

Mechanisms of acetaminophen-induced cell death in primary human hepatocytes

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

Xie, Yuchao; McGill, Mitchell R.; Dorko, Kenneth

Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5 mM, 10 mM or 20 mM APAP over a period of 48 h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24 h, which correlated with the clinicalmore » onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3 h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12 h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3 h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24 h and 48 h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6 h after APAP and a partial protection when given at 15 h. Conclusion: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic. - Highlights: • APAP reproducibly causes cell death in freshly isolated primary human hepatocytes. • APAP induces adduct formation, JNK activation and mitochondrial dysfunction in PHH. • Mitochondrial adducts and JNK translocation are delayed in PHH compared to mice. • JNK inhibitor SP600125 partially protects against APAP-induced cell death in PHH. • N-acetylcysteine provides significant protection even if administered 6 h after APAP.« less

Changes in interleukin-1 signal modulators induced by 3,4-methylenedioxymethamphetamine (MDMA): regulation by CB2 receptors and implications for neurotoxicity

PubMed Central

2011-01-01

Background 3,4-Methylenedioxymethamphetamine (MDMA) produces a neuroinflammatory reaction in rat brain characterized by an increase in interleukin-1 beta (IL-1β) and microglial activation. The CB2 receptor agonist JWH-015 reduces both these changes and partially protects against MDMA-induced neurotoxicity. We have examined MDMA-induced changes in IL-1 receptor antagonist (IL-1ra) levels and IL-1 receptor type I (IL-1RI) expression and the effects of JWH-015. The cellular location of IL-1β and IL-1RI was also examined. MDMA-treated animals were given the soluble form of IL-1RI (sIL-1RI) and neurotoxic effects examined. Methods Dark Agouti rats received MDMA (12.5 mg/kg, i.p.) and levels of IL-1ra and expression of IL-1RI measured 1 h, 3 h or 6 h later. JWH-015 (2.4 mg/kg, i.p.) was injected 48 h, 24 h and 0.5 h before MDMA and IL-1ra and IL-1RI measured. For localization studies, animals were sacrificed 1 h or 3 h following MDMA and stained for IL-1β or IL-1RI in combination with neuronal and microglial markers. sIL-1RI (3 μg/animal; i.c.v.) was administered 5 min before MDMA and 3 h later. 5-HT transporter density was determined 7 days after MDMA injection. Results MDMA produced an increase in IL-ra levels and a decrease in IL-1RI expression in hypothalamus which was prevented by CB2 receptor activation. IL-1RI expression was localized on neuronal cell bodies while IL-1β expression was observed in microglial cells following MDMA. sIL-1RI potentiated MDMA-induced neurotoxicity. MDMA also increased IgG immunostaining indicating that blood brain-barrier permeability was compromised. Conclusions In summary, MDMA produces changes in IL-1 signal modulators which are modified by CB2 receptor activation. These results indicate that IL-1β may play a partial role in MDMA-induced neurotoxicity. PMID:21595923

Heat Shock Enhances the Expression of the Human T Cell Leukemia Virus Type-I (HTLV-I) Trans-Activator (Tax) Antigen in Human HTLV-I Infected Primary and Cultured T Cells.

PubMed

Kunihiro, Marie; Fujii, Hideki; Miyagi, Takuya; Takahashi, Yoshiaki; Tanaka, Reiko; Fukushima, Takuya; Ansari, Aftab A; Tanaka, Yuetsu

2016-07-11

The environmental factors that lead to the reactivation of human T cell leukemia virus type-1 (HTLV-I) in latently infected T cells in vivo remain unknown. It has been previously shown that heat shock (HS) is a potent inducer of HTLV-I viral protein expression in long-term cultured cell lines. However, the precise HTLV-I protein(s) and mechanisms by which HS induces its effect remain ill-defined. We initiated these studies by first monitoring the levels of the trans-activator (Tax) protein induced by exposure of the HTLV-I infected cell line to HS. HS treatment at 43 °C for 30 min for 24 h led to marked increases in the level of Tax antigen expression in all HTLV-I-infected T cell lines tested including a number of HTLV-I-naturally infected T cell lines. HS also increased the expression of functional HTLV-I envelope gp46 antigen, as shown by increased syncytium formation activity. Interestingly, the enhancing effect of HS was partially inhibited by the addition of the heat shock protein 70 (HSP70)-inhibitor pifithlin-μ (PFT). In contrast, the HSP 70-inducer zerumbone (ZER) enhanced Tax expression in the absence of HS. These data suggest that HSP 70 is at least partially involved in HS-mediated stimulation of Tax expression. As expected, HS resulted in enhanced expression of the Tax-inducible host antigens, such as CD83 and OX40. Finally, we confirmed that HS enhanced the levels of Tax and gp46 antigen expression in primary human CD4⁺ T cells isolated from HTLV-I-infected humanized NOD/SCID/γc null (NOG) mice and HTLV-I carriers. In summary, the data presented herein indicate that HS is one of the environmental factors involved in the reactivation of HTLV-I in vivo via enhanced Tax expression, which may favor HTLV-I expansion in vivo.

Effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks

NASA Astrophysics Data System (ADS)

Sun, Xiaojuan; Perc, Matjaž; Kurths, Jürgen

2017-05-01

In this paper, we study effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks. Our focus is on the impact of two parameters, namely the time delay τ and the probability of partial time delay pdelay, whereby the latter determines the probability with which a connection between two neurons is delayed. Our research reveals that partial time delays significantly affect phase synchronization in this system. In particular, partial time delays can either enhance or decrease phase synchronization and induce synchronization transitions with changes in the mean firing rate of neurons, as well as induce switching between synchronized neurons with period-1 firing to synchronized neurons with period-2 firing. Moreover, in comparison to a neuronal network where all connections are delayed, we show that small partial time delay probabilities have especially different influences on phase synchronization of neuronal networks.

Effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks.

PubMed

Sun, Xiaojuan; Perc, Matjaž; Kurths, Jürgen

2017-05-01

In this paper, we study effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks. Our focus is on the impact of two parameters, namely the time delay τ and the probability of partial time delay p delay , whereby the latter determines the probability with which a connection between two neurons is delayed. Our research reveals that partial time delays significantly affect phase synchronization in this system. In particular, partial time delays can either enhance or decrease phase synchronization and induce synchronization transitions with changes in the mean firing rate of neurons, as well as induce switching between synchronized neurons with period-1 firing to synchronized neurons with period-2 firing. Moreover, in comparison to a neuronal network where all connections are delayed, we show that small partial time delay probabilities have especially different influences on phase synchronization of neuronal networks.

Curcumin attenuates insulin resistance in hepatocytes by inducing Nrf2 nuclear translocation.

PubMed

Zhao, Shu-Guang; Li, Qiang; Liu, Zhen-Xiong; Wang, Jing-Jie; Wang, Xv-Xia; Qin, Ming; Wen, Qin-Sheng

2011-01-01

NF-E2-Related Factor-2 (Nrf2) is a transcription factor that plays a crucial role in the cellular protection against oxidative stress. Curcumin has been reported to induce Nrf2 nuclear translocation and upregulate the expression of numerous reactive oxygen species (ROS) detoxifying and antioxidant genes in hepatocytes. This study was designed to investigate whether curcumin-induced Nrf2 nuclear translocation could reduce ROS-mediated insulin resistance in cultured LO2 hepatocytes. Human LO2 hepatocytes were incubated with curcumine and glucose oxidase (GO) in the presence/absence of wortmannin (a phosphatidyinositol 3-kinase (PI3K) inhibitor), oxidative stress, cellular damage, Nrf2 nuclear translocation and insulin resistance were measured. GO exposure significantly increased intracellular ROS, glutathione (GSH) depletion, malondialdehyde (MDA) formation, and increased activities of cellular lactate dehydrogenase (LDH) and aspartate amino transferase (AST), as well as causing insulin resistance. Curcumin pretreatment significantly attenuated these disturbances in intracellular ROS, liver enzyme activity and significantly antagonized the lipid peroxidation, GSH depletion and insulin resistance induced by GO in LO2 hepatocytes. These effects paralleled Nrf2 nuclear translocation induced by curcumin. Wortmannin partially blocked curcumin-induced Nrf2 nuclear translocation. In addition, wortmannin prevented curcumin-induced improvements in intracellular ROS, MDA formation, GSH depletion, liver enzyme activity and insulin resistance in cultured LO2 hepatocytes. These findings suggest that curcumin could reduce ROS-mediated insulin resistance in hepatocytes, at least in part through nuclear translocation of Nrf2.

Buspirone Counteracts MK-801-Induced Schizophrenia-Like Phenotypes through Dopamine D3 Receptor Blockade

PubMed Central

Torrisi, Sebastiano Alfio; Salomone, Salvatore; Geraci, Federica; Caraci, Filippo; Bucolo, Claudio; Drago, Filippo; Leggio, Gian Marco

2017-01-01

Background: Several efforts have been made to develop effective antipsychotic drugs. Currently, available antipsychotics are effective on positive symptoms, less on negative symptoms, but not on cognitive impairment, a clinically relevant dimension of schizophrenia. Drug repurposing offers great advantages over the long-lasting, risky and expensive, de novo drug discovery strategy. To our knowledge, the possible antipsychotic properties of buspirone, an azapirone anxiolytic drug marketed in 1986 as serotonin 5-HT1A receptor (5-HT1AR) partial agonist, have not been extensively investigated despite its intriguing pharmacodynamic profile, which includes dopamine D3 (D3R) and D4 receptor (D4R) antagonist activity. Multiple lines of evidence point to D3R as a valid therapeutic target for the treatment of several neuropsychiatric disorders including schizophrenia. In the present study, we tested the hypothesis that buspirone, behaving as dopamine D3R antagonist, may have antipsychotic-like activity. Materials and Methods: Effects of acute administration of buspirone was assessed on a wide-range of schizophrenia-relevant abnormalities induced by a single administration of the non-competitive NMDAR antagonist MK-801, in both wild-type mice (WT) and D3R-null mutant mice (D3R-/-). Results: Buspirone (3 mg⋅kg-1, i.p.) was devoid of cataleptogenic activity in itself, but resulted effective in counteracting disruption of prepulse inhibition (PPI), hyperlocomotion and deficit of temporal order recognition memory (TOR) induced by MK-801 (0.1 mg⋅kg-1, i.p.) in WT mice. Conversely, in D3R-/- mice, buspirone was ineffective in preventing MK-801-induced TOR deficit and it was only partially effective in blocking MK-801-stimulated hyperlocomotion. Conclusion: Taken together, these results indicate, for the first time, that buspirone, might be a potential therapeutic medication for the treatment of schizophrenia. In particular, buspirone, through its D3R antagonist activity, may be a useful tool for improving the treatment of cognitive deficits in schizophrenia that still represents an unmet need of this disease. PMID:29046641

Simvastatin induces caspase-independent apoptosis in LPS-activated RAW264.7 macrophage cells

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

Kim, Yong Chan; Song, Seok Bean; Lee, Mi Hee

Macrophages participate in several inflammatory pathologies such as sepsis and arthritis. We examined the effect of simvastatin on the LPS-induced proinflammatory macrophage RAW264.7 cells. Co-treatment of LPS and a non-toxic dose of simvastatin induced cell death in RAW264.7 cells. The cell death was accompanied by disruption of mitochondrial membrane potential (MMP), genomic DNA fragmentation, and caspase-3 activation. Surprisingly, despite caspase-dependent apoptotic cascade being completely blocked by Z-VAD-fmk, a pan-caspase inhibitor, the cell death was only partially repressed. In the presence of Z-VAD-fmk, DNA fragmentation was blocked, but DNA condensation, disruption of MMP, and nuclear translocation of apoptosis inducing factor weremore » obvious. The cell death by simvastatin and LPS was effectively decreased by both the FPP and GGPP treatments as well as mevalonate. Our findings indicate that simvastatin triggers the cell death of LPS-treated RAW264.7 cells through both caspase-dependent and -independent apoptotic pathways, suggesting a novel mechanism of statins for the severe inflammatory disease therapy.« less

Coincidences in time of the Imbrium Basin impact and Apollo 15 KREEP volcanic series: Impact-induced melting?

NASA Technical Reports Server (NTRS)

Ryder, Graham

1992-01-01

On the Earth there may be no firm evidence that impacts can induce volcanic activity. However, the Moon does provide a very likely example of volcanism induced by an immense impact: the Imbrium Basin-forming event was immediately succeeded by a crustal partial melting event that released KREEP lava flows over a wide area. These two events are presently indistinguishable in radiometric age. The sample record indicates that such KREEP volcanism had not occurred in the region prior to that time, and never occurred again. Such coincidence in time implies a genetic relationship between the two events, and impact-induced partial melting appears to be the only candidate process. This conclusion rests essentially on the arguments that: (1) the Imbrium Basin event took place 3.86 +/- 0.02 Ga ago; (2) the Apennine Bench Formation postdates Imbrium; (3) the Apollo 15 KREEP basalts are 3.85 +/- 0.03 Ga old; (4) the Apollo 15 KREEP basalts are derived from the Apennine Bench Formation; and (5) the Apollo 15 KREEP basalts are volcanic. Thus, the Apollo 15 KREEP basalts represent a unique volcanic unit that immediately postdates the Imbrium event (within 20 Ma, possibly much less). The evidence for the links in the argument are sketched, and some implications for initial conditions are described. Ramifications of the process for the early history of the Earth are briefly explored.

F-actin clustering and cell dysmotility induced by the pathological W148R missense mutation of filamin B at the actin-binding domain.

PubMed

Zhao, Yongtong; Shapiro, Sandor S; Eto, Masumi

2016-01-01

Filamin B (FLNB) is a dimeric actin-binding protein that orchestrates the reorganization of the actin cytoskeleton. Congenital mutations of FLNB at the actin-binding domain (ABD) are known to cause abnormalities of skeletal development, such as atelosteogenesis types I and III and Larsen's syndrome, although the underlying mechanisms are poorly understood. Here, using fluorescence microscopy, we characterized the reorganization of the actin cytoskeleton in cells expressing each of six pathological FLNB mutants that have been linked to skeletal abnormalities. The subfractionation assay showed a greater accumulation of the FLNB ABD mutants W148R and E227K than the wild-type protein to the cytoskeleton. Ectopic expression of FLNB-W148R and, to a lesser extent, FLNB-E227K induced prominent F-actin accumulations and the consequent rearrangement of focal adhesions, myosin II, and septin filaments and results in a delayed directional migration of the cells. The W148R protein-induced cytoskeletal rearrangement was partially attenuated by the inhibition of myosin II, p21-activated protein kinase, or Rho-associated protein kinase. The expression of a single-head ABD fragment with the mutations partially mimicked the rearrangement induced by the dimer. The F-actin clustering through the interaction with the mutant FLNB ABD may limit the cytoskeletal reorganization, preventing normal skeletal development. Copyright © 2016 the American Physiological Society.

Synthesis, characterization and deepening in the comprehension of the biological action mechanisms of a new nickel complex with antiproliferative activity.

PubMed

Buschini, Annamaria; Pinelli, Silvana; Pellacani, Claudia; Giordani, Federica; Ferrari, Marisa Belicchi; Bisceglie, Franco; Giannetto, Marco; Pelosi, Giorgio; Tarasconi, Pieralberto

2009-05-01

Thiosemicarbazones are versatile organic compounds that present considerable pharmaceutical interest because of a wide range of properties. In our laboratory we synthesised some new metal-complexes with thiosemicarbazones derived from natural aldehydes which showed peculiar biological activities. In particular, a nickel complex [Ni(S-tcitr)(2)] (S-tcitr=S-citronellalthiosemicarbazonate) was observed to induce an antiproliferative effect on U937, a human histiocytic lymphoma cell line, at low concentrations (IC(50)=14.4microM). Therefore, we decided to study the interactions of this molecule with various cellular components and to characterise the induced apoptotic pathway. Results showed that [Ni(S-tcitr)(2)] causes programmed cell death via down-regulation of Bcl-2, alteration of mitochondrial membrane potential and caspase-3 activity, regardless of p53 function. The metal complex is not active on G(0) cells (i.e. fresh leukocytes) but is able to induce perturbation of the cell cycle on stimulated lymphocytes and U937 cells, in which a G(2)/M block was detected. It reaches the nucleus where it induces, at low concentrations (2.5-5.0microM), DNA damage, which could be partially ascribed to oxidative stress. [Ni(S-tcitr)(2)] is moreover able to strongly reduce the telomerase activity. Although the biological target of this metal complex is still unknown, the reported data suggest that [Ni(S-tcitr)(2)] could be a good model for the synthesis of new metal thiosemicarbazones with specific biological activity.

Biodosimetry Based on γ-H2AX Quantification and Cytogenetics after Partial- and Total-Body Irradiation during Fractionated Radiotherapy.

PubMed

Zahnreich, Sebastian; Ebersberger, Anne; Kaina, Bernd; Schmidberger, Heinz

2015-04-01

The aim of this current study was to quantitatively describe radiation-induced DNA damage and its distribution in leukocytes of cancer patients after fractionated partial- or total-body radiotherapy. Specifically, the impact of exposed anatomic region and administered dose was investigated in breast and prostate cancer patients receiving partial-body radiotherapy. DNA double-strand breaks (DSBs) were quantified by γ-H2AX immunostaining. The frequency of unstable chromosomal aberrations in stimulated lymphocytes was also determined and compared with the frequency of DNA DSBs in the same samples. The frequency of radiation-induced DNA damage was converted into dose, using ex vivo generated calibration curves, and was then compared with the administered physical dose. This study showed that 0.5 h after partial-body radiotherapy the quantity of radiation-induced γ-H2AX foci increased linearly with the administered equivalent whole-body dose for both tumor entities. Foci frequencies dropped 1 day thereafter but proportionality to the equivalent whole-body dose was maintained. Conversely, the frequency of radiation-induced cytogenetic damage increased from 0.5 h to 1 day after the first partial-body exposure with a linear dependence on the administered equivalent whole-body dose, for prostate cancer patients only. Only γ-H2AX foci assessment immediately after partial-body radiotherapy was a reliable measure of the expected equivalent whole-body dose. Local tumor doses could be approximated with both assays after one day. After total-body radiotherapy satisfactory dose estimates were achieved with both assays up to 8 h after exposure. In conclusion, the quantification of radiation-induced γ-H2AX foci, but not cytogenetic damage in peripheral leukocytes was a sensitive and rapid biodosimeter after acute heterogeneous irradiation of partial body volumes that was able to primarily assess the absorbed equivalent whole-body dose.

Agonist-induced modulation of inverse agonist efficacy at the beta 2-adrenergic receptor.

PubMed

Chidiac, P; Nouet, S; Bouvier, M

1996-09-01

Sustained stimulation of several G protein-coupled receptors is known to lead to a reduction in the signaling efficacy. This phenomenon, named agonist-induced desensitization, has been best studied for the beta 2-adrenergic receptor (AR) and is characterized by a decreased efficacy of beta-adrenergic agonists to stimulate the adenylyl cyclase activity. Recently, several beta-adrenergic ligands were found to inhibit the spontaneous agonist-independent activity of the beta 2AR. These compounds, termed inverse agonists, have different inhibitory efficacies, ranging from almost neutral antagonists to full inverse agonists. The current study was undertaken to determine whether, as is the case for agonists, desensitization can affect the efficacies of inverse agonists. Agonist-promoted desensitization of the human beta 2AR expressed in Sf9 cells potentiated the inhibitory actions of the inverse agonists, with the extent of the potentiation being inversely proportional to their intrinsic activity. For example, desensitization increased the inhibitory action of the weak inverse agonist labetalol by 29%, whereas inhibition of the spontaneous activity by the strong inverse agonist timolol was not enhanced by the desensitizing stimuli. Interestingly, dichloroisoproterenol acted stochastically as either a weak partial agonist or a weak inverse agonist in control conditions but always behaved as an inverse agonist after desensitization. These data demonstrate that like for agonists, the efficacies of inverse agonists can be modulated by a desensitizing treatment. Also, the data show that the initial state of the receptor can determine whether a ligand behaves as a partial agonist or an inverse agonist.

Partially hydrolyzed guar gum enhances colonic epithelial wound healing via activation of RhoA and ERK1/2.

PubMed

Horii, Yusuke; Uchiyama, Kazuhiko; Toyokawa, Yuki; Hotta, Yuma; Tanaka, Makoto; Yasukawa, Zenta; Tokunaga, Makoto; Okubo, Tsutomu; Mizushima, Katsura; Higashimura, Yasuki; Dohi, Osamu; Okayama, Tetsuya; Yoshida, Naohisa; Katada, Kazuhiro; Kamada, Kazuhiro; Handa, Osamu; Ishikawa, Takeshi; Takagi, Tomohisa; Konishi, Hideyuki; Naito, Yuji; Itoh, Yoshito

2016-07-13

Healing of the intestinal mucosal epithelium was found to be a critical factor in the treatment of inflammatory bowel disease (IBD). In this study, we provide further evidence that partially hydrolyzed dietary fiber (PHGG) enhances colonic epithelial cell wound healing, and partially characterize the mechanism that governs this process. Young adult mouse colonic (YAMC) epithelial cells were scraped with a 10 μl micro-pipette tip to denude a round of the monolayer and were incubated with PHGG. The area of cell migration was measured using Image J software. Meanwhile, Rho activation assays were utilized to monitor Rho activation levels. To assess in vivo effects, C57B6 mice were treated with DSS for 7 days and then provided food supplemented with PHGG for 8 days. YAMC cells treated with PHGG exhibited significantly enhanced wound healing compared to the control cells; however, this enhancement was inhibited by both Y-27632 (RhoA inhibitor) and U0126 (ERK1/2 inhibitor). Likewise, there was a PHGG-dependent increase in F-actin accumulation and Rho kinase activity that was blocked by U0126. Meanwhile, PHGG-dependent ERK1/2 activity was not inhibited by Y-27632. In the DSS-induced mouse colitis model, animals that received food supplemented with PHGG exhibited significant recovery of the colonic mucosa. In this study, we demonstrate that PHGG promotes colonic epithelial cell wound healing via activation of RhoA, which occurs downstream of ERK1/2 activation. These findings indicate that PHGG could be utilized as a therapeutic agent for patients with intestinal mucosal damage such as those with IBD.

Myricetin protects against diet-induced obesity and ameliorates oxidative stress in C57BL/6 mice.

PubMed

Su, Hong-Ming; Feng, Li-Na; Zheng, Xiao-Dong; Chen, Wei

2016-06-01

Myricetin is a naturally occurring antioxidant commonly found in various plants. However, little information is available with respect to its direct anti-obesity effects. This study was undertaken to investigate the effect of myricetin on high-fat diet (HFD)-induced obesity in C57BL/6 mice. Administration of myricetin dramatically reduced the body weight of diet-induced obese mice compared with solely HFD-induced mice. Several parameters related to obesity including serum glucose, triglyceride, and cholesterol were significantly decreased in myricetin-treated mice. Moreover, obesity-associated oxidative stress (glutathione peroxidase (GPX) activity, total antioxidant capacity (T-AOC), and malondialdehyde (MDA)) and inflammation (tumor necrosis factor-α (TNF-α)) were ameliorated in myricetin-treated mice. Further investigation revealed that the protective effect of myricetin against HFD-induced obesity in mice appeared to be partially mediated through the down-regulation of mRNA expression of adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), and lipogenic transcription factor sterol regulatory element-binding protein 1c (SREBP-1c). Consumption of myricetin may help to prevent obesity and obesity-related metabolic complications.

Myricetin protects against diet-induced obesity and ameliorates oxidative stress in C57BL/6 mice*

PubMed Central

Su, Hong-ming; Feng, Li-na; Zheng, Xiao-dong; Chen, Wei

2016-01-01

Background: Myricetin is a naturally occurring antioxidant commonly found in various plants. However, little information is available with respect to its direct anti-obesity effects. Objective: This study was undertaken to investigate the effect of myricetin on high-fat diet (HFD)-induced obesity in C57BL/6 mice. Results: Administration of myricetin dramatically reduced the body weight of diet-induced obese mice compared with solely HFD-induced mice. Several parameters related to obesity including serum glucose, triglyceride, and cholesterol were significantly decreased in myricetin-treated mice. Moreover, obesity-associated oxidative stress (glutathione peroxidase (GPX) activity, total antioxidant capacity (T-AOC), and malondialdehyde (MDA)) and inflammation (tumor necrosis factor-α (TNF-α)) were ameliorated in myricetin-treated mice. Further investigation revealed that the protective effect of myricetin against HFD-induced obesity in mice appeared to be partially mediated through the down-regulation of mRNA expression of adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), and lipogenic transcription factor sterol regulatory element-binding protein 1c (SREBP-1c). Conclusions: Consumption of myricetin may help to prevent obesity and obesity-related metabolic complications. PMID:27256677

Tungstate-Targeting of BKαβ1 Channels Tunes ERK Phosphorylation and Cell Proliferation in Human Vascular Smooth Muscle

PubMed Central

Fernández-Mariño, Ana Isabel; Cidad, Pilar; Zafra, Delia; Nocito, Laura; Domínguez, Jorge; Oliván-Viguera, Aida; Köhler, Ralf; López-López, José R.; Pérez-García, María Teresa; Valverde, Miguel Ángel; Guinovart, Joan J.; Fernández-Fernández, José M.

2015-01-01

Despite the substantial knowledge on the antidiabetic, antiobesity and antihypertensive actions of tungstate, information on its primary target/s is scarce. Tungstate activates both the ERK1/2 pathway and the vascular voltage- and Ca2+-dependent large-conductance BKαβ1 potassium channel, which modulates vascular smooth muscle cell (VSMC) proliferation and function, respectively. Here, we have assessed the possible involvement of BKαβ1 channels in the tungstate-induced ERK phosphorylation and its relevance for VSMC proliferation. Western blot analysis in HEK cell lines showed that expression of vascular BKαβ1 channels potentiates the tungstate-induced ERK1/2 phosphorylation in a Gi/o protein-dependent manner. Tungstate activated BKαβ1 channels upstream of G proteins as channel activation was not altered by the inhibition of G proteins with GDPβS or pertussis toxin. Moreover, analysis of Gi/o protein activation measuring the FRET among heterologously expressed Gi protein subunits suggested that tungstate-targeting of BKαβ1 channels promotes G protein activation. Single channel recordings on VSMCs from wild-type and β1-knockout mice indicated that the presence of the regulatory β1 subunit was essential for the tungstate-mediated activation of BK channels in VSMCs. Moreover, the specific BK channel blocker iberiotoxin lowered tungstate-induced ERK phosphorylation by 55% and partially reverted (by 51%) the tungstate-produced reduction of platelet-derived growth factor (PDGF)-induced proliferation in human VSMCs. Our observations indicate that tungstate-targeting of BKαβ1 channels promotes activation of PTX-sensitive Gi proteins to enhance the tungstate-induced phosphorylation of ERK, and inhibits PDGF-stimulated cell proliferation in human vascular smooth muscle. PMID:25659150

Suppression of noise-induced hyperactivity in the dorsal cochlear nucleus following application of the cholinergic agonist, carbachol

PubMed Central

Manzoor, N.F.; Chen, G.; Kaltenbach, J.A.

2013-01-01

Increased spontaneous firing (hyperactivity) is induced in fusiform cells of the dorsal cochlear nucleus (DCN) following intense sound exposure and is implicated as a possible neural correlate of noise-induced tinnitus. Previous studies have shown that in normal hearing animals, fusiform cell activity can be modulated by activation of parallel fibers, which represent the axons of granule cells. The modulation consists of a transient excitation followed by a more prolonged period of inhibition, presumably reflecting direct excitatory inputs to fusiform cells and an indirect inhibitory input to fusiform cells from the granule cell-cartwheel cell system. We hypothesized that since granule cells can be activated by cholinergic inputs, it might be possible to suppress tinnitus-related hyperactivity of fusiform cells using the cholinergic agonist, carbachol. To test this hypothesis, we recorded multiunit spontaneous activity in the fusiform soma layer (FSL) of the DCN in control and tone-exposed hamsters (10 kHz, 115 dB SPL, 4 h) before and after application of carbachol to the DCN surface. In both exposed and control animals, 100 µM carbachol had a transient excitatory effect on spontaneous activity followed by a rapid weakening of activity to near or below normal levels. In exposed animals, the weakening of activity was powerful enough to completely abolish the hyperactivity induced by intense sound exposure. This suppressive effect was partially reversed by application of atropine and was not associated with significant changes in neural best frequencies (BF) or BF thresholds. These findings demonstrate that noise-induced hyperactivity can be pharmacologically controlled and raise the possibility that attenuation of tinnitus may be achievable by using an agonist of the cholinergic system. PMID:23721928

Suppression of noise-induced hyperactivity in the dorsal cochlear nucleus following application of the cholinergic agonist, carbachol.

PubMed

Manzoor, N F; Chen, G; Kaltenbach, J A

2013-07-26

Increased spontaneous firing (hyperactivity) is induced in fusiform cells of the dorsal cochlear nucleus (DCN) following intense sound exposure and is implicated as a possible neural correlate of noise-induced tinnitus. Previous studies have shown that in normal hearing animals, fusiform cell activity can be modulated by activation of parallel fibers, which represent the axons of granule cells. The modulation consists of a transient excitation followed by a more prolonged period of inhibition, presumably reflecting direct excitatory inputs to fusiform cells and an indirect inhibitory input to fusiform cells from the granule cell-cartwheel cell system. We hypothesized that since granule cells can be activated by cholinergic inputs, it might be possible to suppress tinnitus-related hyperactivity of fusiform cells using the cholinergic agonist, carbachol. To test this hypothesis, we recorded multiunit spontaneous activity in the fusiform soma layer (FSL) of the DCN in control and tone-exposed hamsters (10 kHz, 115 dB SPL, 4h) before and after application of carbachol to the DCN surface. In both exposed and control animals, 100 μM carbachol had a transient excitatory effect on spontaneous activity followed by a rapid weakening of activity to near or below normal levels. In exposed animals, the weakening of activity was powerful enough to completely abolish the hyperactivity induced by intense sound exposure. This suppressive effect was partially reversed by application of atropine and was usually not associated with significant changes in neural best frequencies (BF) or BF thresholds. These findings demonstrate that noise-induced hyperactivity can be pharmacologically controlled and raise the possibility that attenuation of tinnitus may be achievable by using an agonist of the cholinergic system. Copyright © 2013 Elsevier B.V. All rights reserved.

Hexavalent chromium targets mitochondrial respiratory chain complex I to induce reactive oxygen species-dependent caspase-3 activation in L-02 hepatocytes.

PubMed

Xiao, Fang; Li, Yanhong; Dai, Lu; Deng, Yuanyuan; Zou, Yue; Li, Peng; Yang, Yuan; Zhong, Caigao

2012-09-01

Hexavalent chromium [Cr(VI)], which is used for various industrial applications, such as leather tanning and chroming, can cause a number of human diseases including inflammation and cancer. Cr(VI) exposure leads to severe damage to the liver, but the mechanisms involved in Cr(VI)-mediated toxicity in the liver are unclear. The present study provides evidence that Cr(VI) enhances reactive oxygen species (ROS) accumulation by inhibiting the mitochondrial respiratory chain complex (MRCC) I. Cr(VI) did not affect the expression levels of antioxidative proteins such as superoxide dismutase (SOD), catalase and thioredoxin (Trx), indicating that the antioxidative system was not involved in Cr(VI)-induced ROS accumulation. We found that ROS mediated caspase-3 activation partially depends on the downregulation of the heat shock protein (HSP) 70 and 90. In order to confirm our hypothesis that ROS plays a key role in Cr(VI)-mediated cytotoxicity, we used N-acetylcysteine (NAC) to inhibit the accumulation of ROS. NAC successfully blocked the inhibition of HSP70 and HSP90 as well as the activation of caspase-3, suggesting that ROS is essential in Cr(VI)-induced caspase-3 activation. By applying different MRCC substrates as electron donors, we also confirmed that Cr(VI) could accept the electrons leaked from MRCC I and the reduction occurs at MRCC I. In conclusion, the present study demonstrates that Cr(VI) induces ROS-dependent caspase-3 activation by inhibiting MRCC I activity, and MRCC I has been identified as a new target and a new mechanism for the apoptosis-inducing activity displayed by Cr(VI).

Pharmacodynamics and pharmacokinetics during the transition from warfarin to rivaroxaban: a randomized study in healthy subjects

PubMed Central

Kubitza, Dagmar; Becka, Michael; Mück, Wolfgang; Krätzschmar, Jöern

2014-01-01

Aims This study investigated relevant pharmacodynamic and pharmacokinetic parameters during the transition from warfarin to rivaroxaban in healthy male subjects. Methods Ninety-six healthy men were randomized into the following three groups: warfarin [international normalized ratio (INR) 2.0–3.0] transitioned to rivaroxaban 20 mg once daily (od; group A); warfarin (INR 2.0–3.0) followed by placebo od (group B); and rivaroxaban alone 20 mg od (group C) for 4 days. Anti-factor Xa activity, inhibition of factor Xa activity, prothrombin time (PT), activated partial thromboplastin time, HepTest, prothrombinase-induced clotting time, factor VIIa activity, factor IIa activity, endogenous thrombin potential and pharmacokinetics were measured. Results An additive effect was observed on the PT and PT/INR during the initial transition period. The mean maximal prolongation of PT was 4.39-fold [coefficient of variation (CV) 18.03%; range 3.39–6.50] of the baseline value in group A, compared with 1.88-fold (CV 10.35%; range 1.53–2.21) in group B and 1.57-fold (CV 9.98%; range 1.37–2.09) in group C. Rivaroxaban had minimal influence on the PT/INR at trough levels. Inhibition of factor Xa activity, activated partial thromboplastin time and endogenous thrombin potential were also enhanced, but to a lesser extent. In contrast, the effects of rivaroxaban on anti-factor Xa activity, HepTest and prothrombinase-induced clotting time were not affected by pretreatment with warfarin. Conclusions Changes in pharmacodynamics during the transition from warfarin to rivaroxaban vary depending on the test used. A supra-additive effect on PT/INR is expected during the initial period of transition, but pretreatment with warfarin does not influence the effect of rivaroxaban on anti-factor Xa activity. PMID:24528331

IGF-1-dependent subunit communication of the IGF-1 holoreceptor: Interactions between. alpha. beta. heterodimeric receptor halves

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

Wilden, P.A.; Treadway, J.L.; Morrison, B.D.

1989-12-12

Examination of {sup 125}I-IGF-1 affinity cross-linking and {beta}-subunit autophosphorylation has indicated that IGF-1 induces a covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptors into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state, in a similar manner to that observed for the insulin receptor. The formation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 receptor complex from the partially purified {alpha}{beta} heterodimers was time dependent with half-maximal formation in approximately 30 min at saturating IGF-1 concentrations. The IGF-1-dependent association of the partially purified {alpha}{beta} heterodimers into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state was specific for the IGF-1 receptors since IGF-1 was unable to stimulatemore » the protein kinase activity of the purified {alpha}{beta} heterodimeric insulin receptor complex. Incubation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 holoreceptor with the specific sulfhydryl agent iodoacetamide (IAN) did not alter {sup 125}I-IGF-1 binding or IGF-1 stimulation of protein kinase activity. However, IAN treatment of the {alpha}{beta} heterodimeric IGF-1 receptors inhibited the IGF-1 dependent covalent formation of the disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric complex. These data indicate that IGF-1 induces the covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptor complexes into a disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric state whereas Mn/MgATP induces a noncovalent association. Therefore, unlike the insulin receptor in which noncovalent association is sufficient for kinase activation, only the covalent assembly of the IGF-1 receptor {alpha}{beta} heterodimers into the {alpha}{sub 2}{beta}{sub 2} heterotetrameric holoreceptor complex is associated with ligand-stimulated protein kinase activation.« less

Partial characterization of a putative new growth factor present in pathological human vitreous.

PubMed

Pombo, C; Bokser, L; Casabiell, X; Zugaza, J; Capeans, M; Salorio, M; Casanueva, F

1996-03-01

Several growth factors have been implicated in the development of proliferative eye diseases, and some of those are present in human vitreous (HV). The effects of HV on cellular responses which modulate proliferative cell processes were studied. This study describes the partial characterization of a vitreous factor activity which does not correspond to any of the previously reported growth factors in pathological HV. Vitreous humour was obtained from medical vitrectomies, from patients with PDR and PVR. The biological activity of the vitreous factor was determined by its ability to increase cytosolic calcium concentration ([Ca2+]i), increase production of inositol phosphates, and induce cell proliferation in the cell line EGFR T17. In some experiments other cell lines, such as NIH 3T3, 3T3-L1, FRTL5, A431, PC12, Y79, and GH3, were also employed. Measurement of [Ca2+]i in cell suspensions was performed using the fluorescent Ca2+ indicator fura-2. The activity of the factor present in HV was compared with other growth factors by means of: (a) [Ca2+]i mobilization pattern, (b) sequential homologous and heterologous desensitization of receptors, (c) effects of phorbol esters on their action, and (d) inactivation after treatment with different proteolytic enzymes. The HV-induced cell proliferation and increases in [Ca2+]i concentration were characterized by a peculiar time pattern. The different approaches used ruled out its identity with PDGF, bFGF, EGF, TGF-beta, IGFs, TNF-alpha, NGF, and other compounds such as ATP, angiotensin I, and bradykinin. Vitreous factor actions are mediated by specific receptors apparently regulated by PKC. This factor is able to induce [Ca2+]i mobilization in most of the cell lines studied, indicating that its effects are not tissue specific. These results suggest the presence of a growth factor activity in pathological HV which may be due to the presence of an undescribed growth factor in the eye.

Structural studies of viperin, an antiviral radical SAM enzyme.

PubMed

Fenwick, Michael K; Li, Yue; Cresswell, Peter; Modis, Yorgo; Ealick, Steven E

2017-06-27

Viperin is an IFN-inducible radical S -adenosylmethionine (SAM) enzyme that inhibits viral replication. We determined crystal structures of an anaerobically prepared fragment of mouse viperin (residues 45-362) complexed with S -adenosylhomocysteine (SAH) or 5'-deoxyadenosine (5'-dAdo) and l-methionine (l-Met). Viperin contains a partial (βα) 6 -barrel fold with a disordered N-terminal extension (residues 45-74) and a partially ordered C-terminal extension (residues 285-362) that bridges the partial barrel to form an overall closed barrel structure. Cys84, Cys88, and Cys91 located after the first β-strand bind a [4Fe-4S] cluster. The active site architecture of viperin with bound SAH (a SAM analog) or 5'-dAdo and l-Met (SAM cleavage products) is consistent with the canonical mechanism of 5'-deoxyadenosyl radical generation. The viperin structure, together with sequence alignments, suggests that vertebrate viperins are highly conserved and that fungi contain a viperin-like ortholog. Many bacteria and archaebacteria also express viperin-like enzymes with conserved active site residues. Structural alignments show that viperin is similar to several other radical SAM enzymes, including the molybdenum cofactor biosynthetic enzyme MoaA and the RNA methyltransferase RlmN, which methylates specific nucleotides in rRNA and tRNA. The viperin putative active site contains several conserved positively charged residues, and a portion of the active site shows structural similarity to the GTP-binding site of MoaA, suggesting that the viperin substrate may be a nucleoside triphosphate of some type.

miR-429 mediates δ-tocotrienol-induced apoptosis in triple-negative breast cancer cells by targeting XIAP

PubMed Central

Wang, Chen; Ju, Hong; Shen, Chunyan; Tong, Zhongsheng

2015-01-01

Vitamin E δ-tocotrienol has been reported to possess anticancer activity both in vitro and in vivo. However, the underlying molecular mechanisms of δ-tocotrienol induced apoptosis in triple-negative breast cancer are not fully understood. Here, we reported that microRNA-429 (miR-429) is up-regulated in two TNBC cell lines (MDA-MB-231 and MDA-MB-468), treated with δ-tocotrienol. Inhibition of miR-429 may partially rescue the apoptosis induced by δ-tocotrienol in MDA-MB-231 cells. We also showed that the forced expression of miR-429 was sufficient to lead to apoptosis in MDA-MB-231 cells. Furthermore, we identified X-linked inhibitor of apoptosis protein (XIAP) as one of miR-429’s target genes. These results suggest that the activation of miR-429 by δ-tocotrienol may be an effective approach for the prevention and treatment of triple-negative breast cancer. PMID:26629059

Unrestrained AMPylation targets cytosolic chaperones and activates the heat shock response

PubMed Central

Truttmann, Matthias C.; Zheng, Xu; Hanke, Leo; Damon, Jadyn R.; Grootveld, Monique; Krakowiak, Joanna; Pincus, David; Ploegh, Hidde L.

2017-01-01

Protein AMPylation is a conserved posttranslational modification with emerging roles in endoplasmic reticulum homeostasis. However, the range of substrates and cell biological consequences of AMPylation remain poorly defined. We expressed human and Caenorhabditis elegans AMPylation enzymes—huntingtin yeast-interacting protein E (HYPE) and filamentation-induced by cyclic AMP (FIC)-1, respectively—in Saccharomyces cerevisiae, a eukaryote that lacks endogenous protein AMPylation. Expression of HYPE and FIC-1 in yeast induced a strong cytoplasmic Hsf1-mediated heat shock response, accompanied by attenuation of protein translation, massive protein aggregation, growth arrest, and lethality. Overexpression of Ssa2, a cytosolic heat shock protein (Hsp)70, was sufficient to partially rescue growth. In human cell lines, overexpression of active HYPE similarly induced protein aggregation and the HSF1-dependent heat shock response. Excessive AMPylation also abolished HSP70-dependent influenza virus replication. Our findings suggest a mode of Hsp70 inactivation by AMPylation and point toward a role for protein AMPylation in the regulation of cellular protein homeostasis beyond the endoplasmic reticulum. PMID:28031489

LRH-1 mediates anti-inflammatory and antifungal phenotype of IL-13-activated macrophages through the PPARγ ligand synthesis

PubMed Central

Lefèvre, Lise; Authier, Hélène; Stein, Sokrates; Majorel, Clarisse; Couderc, Bettina; Dardenne, Christophe; Eddine, Mohamad Ala; Meunier, Etienne; Bernad, José; Valentin, Alexis; Pipy, Bernard; Schoonjans, Kristina; Coste, Agnès

2015-01-01

Liver receptor homologue-1 (LRH-1) is a nuclear receptor involved in the repression of inflammatory processes in the hepatointestinal tract. Here we report that LRH-1 is expressed in macrophages and induced by the Th2 cytokine IL-13 via a mechanism involving STAT6. We show that loss-of-function of LRH-1 in macrophages impedes IL-13-induced macrophage polarization due to impaired generation of 15-HETE PPARγ ligands. The incapacity to generate 15-HETE metabolites is at least partially caused by the compromised regulation of CYP1A1 and CYP1B1. Mice with LRH-1-deficient macrophages are, furthermore, highly susceptible to gastrointestinal and systemic Candida albicans infection. Altogether, these results identify LRH-1 as a critical component of the anti-inflammatory and fungicidal response of alternatively activated macrophages that acts upstream from the IL-13-induced 15-HETE/PPARγ axis. PMID:25873311

Angiotensin-(1-7) protects from brain damage induced by shiga toxin 2-producing enterohemorrhagic Escherichia coli.

PubMed

Goldstein, Jorge; Carden, Tomás R; Perez, María J; Taira, Carlos A; Höcht, Christian; Gironacci, Mariela M

2016-12-01

Shiga toxin 2 (Stx2)-producing enterohemorrhagic induced brain damage. Since a cerebroprotective action was reported for angiotensin (Ang)-(1-7), our aim was to investigate whether Ang-(1-7) protects from brain damage induced by Stx2-producing enterohemorrhagic Escherichia coli The anterior hypothalamic area of adult male Wistar rats was injected with saline solution or Stx2 or Stx2 plus Ang-(1-7) or Stx2 plus Ang-(1-7) plus A779. Rats received a single injection of Stx2 at the beginning of the experiment, and Ang-(1-7), A779, or saline was administered daily in a single injection for 8 days. Cellular ultrastructural changes were analyzed by transmission electron microscopy. Stx2 induced neurodegeneration, axonal demyelination, alterations in synapse, and oligodendrocyte and astrocyte damage, accompanied by edema. Ang-(1-7) prevented neuronal damage triggered by the toxin in 55.6 ± 9.5% of the neurons and the Stx2-induced synapse dysfunction was reversed. In addition, Ang-(1-7) blocked Stx2-induced demyelination in 92 ± 4% of the axons. Oligodendrocyte damage caused by Stx2 was prevented by Ang-(1-7) but astrocytes were only partially protected by the peptide (38 ± 5% of astrocytes were preserved). Ang-(1-7) treatment resulted in 50% reduction in the number of activated microglial cells induced by Stx2, suggesting an anti-inflammatory action. All these beneficial effects elicited by Ang-(1-7) were blocked by the Mas receptor antagonist and thus it was concluded that Ang-(1-7) protects mainly neurons and oligodendrocytes, and partially astrocytes, in the central nervous system through Mas receptor stimulation. Copyright © 2016 the American Physiological Society.

Activation of Notch1 inhibits medial edge epithelium apoptosis in all-trans retinoic acid-induced cleft palate in mice

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

Zhang, Yadong; Dong, Shiyi; Wang, Weicai

Administration of all-trans retinoic acid (atRA) on E12.0 (embryonic day 12.0) leads to failure of medial edge epithelium (MEE) disappearance and cleft palate. However, the molecular mechanism underlying the relationship between atRA and MEE remains to be identified. In this study, atRA (200 mg/kg) administered by gavage induced a 75% incidence of cleft palate in C57BL/6 mice. Notch1 was up-regulated in MEE cells in the atRA-treated group compared with the controls at E15.0, together with reduced apoptosis and elevated proliferation. Next, we investigated the mechanisms underlying atRA, Notch1 and MEE degradation in palate organ culture. Our results revealed that down-regulation ofmore » Notch1 partially rescued the inhibition of atRA-induced palate fusion. Molecular analysis indicated that atRA increased the expression of Notch1 and Rbpj and decreased the expression of P21. In addition, depletion of Notch1 expression decreased the expression of Rbpj and increased the expression of P21. Moreover, inhibition of Rbpj expression partially reversed atRA-induced MEE persistence and increased P21 expression. These findings demonstrate that atRA inhibits MEE degradation, which in turn induces a cleft palate, possibly through the Notch1/RBPjk/P21 signaling pathway. - Highlights: • atRA exposure on E12.0 induced MEE persistence and cleft palate. • Notch1 was up-regulated in MEE cells in the atRA-treated embryos. • atRA inhibits MEE degradation, which in turn induces cleft palate, possibly through the Notch1/RBPjk/P21 signaling pathway.« less

Bioassay of procoagulant albumin in human plasma.

PubMed

Grosset, A; Liu, L; Parker, C J; Rodgers, G M

1994-09-01

Procoagulant albumin (P-Al) is present in normal human plasma and increases monocyte and endothelial cell expression of tissue factor activity. To develop a bioassay for P-Al, we partially purified plasma from healthy volunteers and several patient groups using BaCl2 and (NH4)2SO4 precipitation. The samples were assayed for tissue factor (TF) inducing activity, expressed as a percentage increase compared to a serum-free media control. Over six months, the assay was reproducible in stored samples and in serial samples from normal volunteers. The plasma P-Al activities of 35 volunteers averaged 141 +/- 8.2% (SEM). There was no diurnal variation. There was no difference in the P-Al activity after a 12 hour fast and 2 hours after a large meal in 4 healthy volunteers. There was no increase in activity (r = 0.16) with the subject's age. The average activity from 16 poorly-controlled diabetics was 131 +/- 11% (SEM). No alteration in activity was seen with samples from patients with uremia, liver dysfunction, hemophilia, thrombotic events, or adenocarcinoma. These results indicate that P-Al activity can be bioassayed in individual patient samples; however, pathologic states associated with abnormal P-Al-induced tissue factor activity presently remain unidentified.

Effects of activation energy and activation volume on the temperature-dependent viscosity of water.

PubMed

Kwang-Hua, Chu Rainer

2016-08-01

Water transport in a leaf is vulnerable to viscosity-induced changes. Recent research has suggested that these changes may be partially due to variation at the molecular scale, e.g., regulations via aquaporins, that induce reductions in leaf hydraulic conductance. What are the quantitative as well as qualitative changes in temperature-dependent viscosity due to the role of aquaporins in tuning activation energy and activation volume? Using the transition-state approach as well as the boundary perturbation method, we investigate temperature-dependent viscosity tuned by activation energy and activation volume. To validate our approach, we compare our numerical results with previous temperature-dependent viscosity measurements. The rather good fit between our calculations and measurements confirms our present approach. We have obtained critical parameters for the temperature-dependent (shear) viscosity of water that might be relevant to the increasing and reducing of leaf hydraulic conductance. These parameters are sensitive to temperature, activation energy, and activation volume. Once the activation energy increases, the (shear) viscosity of water increases. Our results also show that as the activation volume increases (say, 10^{-23}m^{3}), the (shear) viscosity of water decreases significantly and the latter induces the enhancing of leaf hydraulic conductance. Within the room-temperature regime, a small increase in the activation energy will increase the water viscosity or reduce the leaf hydraulic conductance. Our approach and results can be applied to diverse plant or leaf attributes.

Partial enteral nutrition with a Crohn's disease exclusion diet is effective for induction of remission in children and young adults with Crohn's disease.

PubMed

Sigall-Boneh, Rotem; Pfeffer-Gik, Tamar; Segal, Idit; Zangen, Tsili; Boaz, Mona; Levine, Arie

2014-08-01

Exclusive enteral nutrition is effective for inducing remission in active pediatric Crohn's disease. Partial enteral nutrition (PEN) with free diet is ineffective for inducing remission, suggesting that the mechanism depends on exclusion of free diet. We developed an alternative diet based on PEN with exclusion of dietary components hypothesized to affect the microbiome or intestinal permeability. Children and young adults with active disease defined as a pediatric Crohn's disease activity index >7.5 or Harvey-Bradshaw index ≥4 received a 6-week structured Crohn's disease exclusion diet that allowed access to specific foods and restricted exposure to all other foods, and up to 50% of dietary calories from a polymeric formula. Remission, C-reactive protien, and erythrocyte sedimentation rate were reevaluated at 6 weeks. The primary endpoint was remission at 6 weeks defined as Harvey-Bradshaw index ≤3 for all patients and pediatric Crohn's disease activity index <7.5 in children. We treated 47 patients (mean age, 16.1 ± 5.6 yr; 34 children). Response and remission were obtained in 37 (78.7%) and 33 (70.2%) patients, respectively. Mean pediatric Crohn's disease activity index decreased from 27.7 ± 9.4 to 5.4 ± 8 (P < 0.001), Harvey-Bradshaw index from 6.4 ± 2.7 to 1.8 ± 2.9 (P < 0.001). Remission was obtained in 70% of children and 69% of adults. Normalization of previously elevated CRP occurred in 21 of 30 (70%) patients in remission. Seven patients used the diet without PEN; 6 of 7 obtained remission. Dietary therapy involving PEN with an exclusion diet seems to lead to high remission rates in early mild-to-moderate luminal Crohn's disease in children and young adults.

Auranofin-mediated inhibition of PI3K/AKT/mTOR axis and anticancer activity in non-small cell lung cancer cells

PubMed Central

Li, Hongyu; Hu, Jing; Wu, Shuhong; Wang, Li; Cao, Xiaobo; Zhang, Xiaoshan; Dai, Bingbing; Cao, Mengru; Shao, Ruping; Zhang, Ran; Majidi, Mourad; Ji, Lin; Heymach, John V.; Wang, Michael; Pan, Shiyang; Minna, John; Mehran, Reza J.; Swisher, Stephen G.; Roth, Jack A.; Fang, Bingliang

2016-01-01

Auranofin, a gold complex that has been used to treat rheumatoid arthritis in clinics and has documented pharmacokinetic and safety profiles in humans, has recently been investigated for its anticancer activity in leukemia and some solid cancers. However, auranofin's single agent activity in lung cancer is not well characterized. To determine whether auranofin has single agent activity in lung cancer, we evaluated auranofin's activity in a panel of 10 non-small cell lung cancer (NSCLC) cell lines. Cell viability analysis revealed that auranofin induced growth inhibition in a subset of NSCLC cell lines with a half maximal inhibitory concentration (IC50) below 1.0 μM. Treatment with auranofin elicited apoptosis and necroptosis in auranofin-sensitive cell lines. Moreover, the susceptibility of NSCLC cells to auranofin was inversely correlated with TXNRD1 expression in the cells. Transient transfection of the TXNRD1-expressing plasmid in auranofin-sensitive Calu3 cells resulted in partial resistance, indicating that high TXNRD level is one of causal factors for resistance to auranofin. Further mechanistic characterization with proteomic analysis revealed that auranofin inhibits expression and/or phosphorylation of multiple key nodes in the PI3K/AKT/mTOR pathway, including S6, 4EBP1, Rictor, p70S6K, mTOR, TSC2, AKT and GSK3. Ectopic expression of TXNRD1 partially reversed auranofin-mediated PI3K/AKT/mTOR inhibition, suggesting that TXNRD1 may participate in the regulation of PI3K/AKT/mTOR pathway. Administration of auranofin to mice with xenograft tumors derived from NSCLC cells significantly suppressed tumor growth without inducing obvious toxic effects. Our results demonstrated feasibility of repurposing auranofin for treatment of lung cancer. PMID:26657290

Folding pathway of the pyridoxal 5′-phosphate C-S lyase MalY from Escherichia coli

PubMed Central

2005-01-01

MalY from Escherichia coli is a bifunctional dimeric PLP (pyridoxal 5′-phosphate) enzyme acting as a β-cystathionase and as a repressor of the maltose system. The spectroscopic and molecular properties of the holoenzyme, in the untreated and NaBH4-treated forms, and of the apoenzyme have been elucidated. A systematic study of the urea-induced unfolding of MalY has been monitored by gel filtration, cross-linking, ANS (8-anilino-1-naphthalenesulphonic acid) binding and by visible, near- and far-UV CD, fluorescence and NMR spectroscopies under equilibrium conditions. Unfolding proceeds in at least three stages. The first transition, occurring between 0 and 1 M urea, gives rise to a partially active dimeric species that binds PLP. The second equilibrium transition involving dimer dissociation, release of PLP and loss of lyase activity leads to the formation of a monomeric equilibrium intermediate. It is a partially unfolded molecule that retains most of the native-state secondary structure, binds significant amounts of ANS (a probe for exposed hydrophobic surfaces) and tends to self-associate. The self-associated aggregates predominate at urea concentrations of 2–4 M for holoMalY. The third step represents the complete unfolding of the enzyme. These results when compared with the urea-induced unfolding profiles of apoMalY and NaBH4-reduced holoenzyme suggest that the coenzyme group attached to the active-site lysine residue increases the stability of the dimeric enzyme. Both holo- and apo-MalY could be successfully refolded into the active enzyme with an 85% yield. Further refolding studies suggest that large misfolded soluble aggregates that cannot be refolded could be responsible for the incomplete re-activation. PMID:15823094

Thrombospondin-1 is a novel negative regulator of liver regeneration after partial hepatectomy through transforming growth factor-beta1 activation in mice.

PubMed

Hayashi, Hiromitsu; Sakai, Keiko; Baba, Hideo; Sakai, Takao

2012-05-01

The matricellular protein, thrombospondin-1 (TSP-1), is prominently expressed during tissue repair. TSP-1 binds to matrix components, proteases, cytokines, and growth factors and activates intracellular signals through its multiple domains. TSP-1 converts latent transforming growth factor-beta1 (TGF-β1) complexes into their biologically active form. TGF-β plays significant roles in cell-cycle regulation, modulation of differentiation, and induction of apoptosis. Although TGF-β1 is a major inhibitor of proliferation in cultured hepatocytes, the functional requirement of TGF-β1 during liver regeneration remains to be defined in vivo. We generated a TSP-1-deficient mouse model of a partial hepatectomy (PH) and explored TSP-1 induction, progression of liver regeneration, and TGF-β-mediated signaling during the repair process after hepatectomy. We show here that TSP-1-mediated TGF-β1 activation plays an important role in suppressing hepatocyte proliferation. TSP-1 expression was induced in endothelial cells (ECs) as an immediate early gene in response to PH. TSP-1 deficiency resulted in significantly reduced TGF-β/Smad signaling and accelerated hepatocyte proliferation through down-regulation of p21 protein expression. TSP-1 induced in ECs by reactive oxygen species (ROS) modulated TGF-β/Smad signaling and proliferation in hepatocytes in vitro, suggesting that the immediately and transiently produced ROS in the regenerating liver were the responsible factor for TSP-1 induction. We have identified TSP-1 as an inhibitory element in regulating liver regeneration by TGF-β1 activation. Our work defines TSP-1 as a novel immediate early gene that could be a potential therapeutic target to accelerate liver regeneration. Copyright © 2011 American Association for the Study of Liver Diseases.

MCPIP1 contributes to the toxicity of proteasome inhibitor MG-132 in HeLa cells by the inhibition of NF-κB.

PubMed

Skalniak, Lukasz; Dziendziel, Monika; Jura, Jolanta

2014-10-01

Recently, we have shown that the treatment of cells with proteasome inhibitor MG-132 results in the induction of expression of monocyte chemotactic protein-1 induced protein 1 (MCPIP1). MCPIP1 is a ribonuclease, responsible for the degradation of transcripts encoding certain pro-inflammatory cytokines. The protein is also known as an inhibitor of NF-κB transcription factor. Thanks to its molecular properties, MCPIP1 is considered as a regulator of inflammation, differentiation, and survival. Using siRNA technology, we show here that MCPIP1 expression contributes to the toxic properties of MG-132 in HeLa cells. The inhibition of proteasome by MG-132 and epoxomicin markedly increased MCPIP1 expression. While MG-132 induces HeLa cell death, down-regulation of MCPIP1 expression by siRNA partially protects HeLa cells from MG-132 toxicity and restores Nuclear factor-κB (NF-κB) activity, inhibited by MG-132 treatment. Inversely, overexpression of MCPIP1 decreased constitutive activity of NF-κB and limited the survival of HeLa cells, as we have shown in the previous study. Interestingly, although MG-132 decreased the expression of IκBα and increased p65 phosphorylation, the inhibition of constitutive NF-κB activity was observed in MG-132-treated cells. Since the elevated constitutive activity of NF-κB is one of the mechanisms providing increased survival of cancer cells, including HeLa cells, we propose that death-promoting properties of MCPIP1 in MG-132-treated HeLa cells may, at least partially, derive from the negative effect on the constitutive NF-κB activity.

Anticonvulsant and Antioxidant Effects of Tilia americana var. mexicana and Flavonoids Constituents in the Pentylenetetrazole-Induced Seizures

PubMed Central

Cárdenas-Rodríguez, Noemí; González-Trujano, María Eva; Aguirre-Hernández, Eva; Ruíz-García, Matilde; Sampieri, Aristides; Coballase-Urrutia, Elvia; Carmona-Aparicio, Liliana

2014-01-01

Tilia genus is commonly used around the world for its central nervous system properties; it is prepared as tea and used as tranquilizing, anticonvulsant, and analgesic. In this study, anticonvulsant activity of the Tilia americana var. mexicana inflorescences and leaves was investigated by evaluating organic and aqueous extracts (100, 300, and 600 mg/kg, i.p.) and some flavonoids in the pentylenetetrazole-induced seizures in mice. Moreover, antioxidant effect of these extracts and flavonoids was examined in an in vitro study by using spectrophotometric technique. Significant activity was observed in the methanol extract from inflorescences. An HPLC analysis of the methanol extract from inflorescences and leaves of Tilia allowed demonstrating the respective presence of some partial responsible flavonoid constituents: quercetin (20.09 ± 1.20 μg/mg and 3.39 ± 0.10 μg/mg), rutin (3.52 ± 0.21 μg/mg and 8.94 ± 0.45 μg/mg), and isoquercitrin (1.74 ± 0.01 μg/mg and 1.24 ± 0.13 μg/mg). In addition, significant but different antioxidant properties were obtained among the flavonoids and the extracts investigated. Our results provide evidence of the anticonvulsant activity of Tilia reinforcing its utility for central nervous system diseases whose mechanism of action might involve partial antioxidant effects due to the presence of flavonoids. PMID:25197430

To Resolve or Not To Resolve, that Is the Question: The Dual-Path Model of Incongruity Resolution and Absurd Verbal Humor by fMRI

PubMed Central

Dai, Ru H.; Chen, Hsueh-Chih; Chan, Yu C.; Wu, Ching-Lin; Li, Ping; Cho, Shu L.; Hu, Jon-Fan

2017-01-01

It is well accepted that the humor comprehension processing involves incongruity detection and resolution and then induces a feeling of amusement. However, this three-stage model of humor processing does not apply to absurd humor (so-called nonsense humor). Absurd humor contains an unresolvable incongruity but can still induce a feeling of mirth. In this study, we used functional magnetic resonance imaging (fMRI) to identify the neural mechanisms of absurd humor. Specifically, we aimed to investigate the neural substrates associated with the complete resolution of incongruity resolution humor and partial resolution of absurd humor. Based on the fMRI data, we propose a dual-path model of incongruity resolution and absurd verbal humor. According to this model, the detection and resolution for the incongruity of incongruity resolution humor activate brain regions involved in the temporo-parietal lobe (TPJ) implicated in the integration of multiple information and precuneus, likely to be involved in the ability of perspective taking. The appreciation of incongruity resolution humor activates regions the posterior cingulate cortex (PCC), implicated in autobiographic or event memory retrieval, and parahippocampal gyrus (PHG), implying the funny feeling. By contrast, the partial resolution of absurd humor elicits greater activation in the fusiform gyrus which have been implicated in word processing, inferior frontal gyrus (IFG) for the process of incongruity resolution and superior temporal gyrus (STG) for the pragmatic awareness. PMID:28484402

Retinoic Acid Protects Cardiomyocytes from High Glucose-Induced Apoptosis via Inhibition of Sustained Activation of NF-κB Signaling

PubMed Central

Nizamutdinova, Irina T.; Guleria, Rakeshwar S.; Singh, Amar B.; Kendall, Jonathan A.; Baker, Kenneth M.; Pan, Jing

2012-01-01

We have previously shown that retinoic acid (RA) has protective effects on high glucose (HG)-induced cardiomyocyte apoptosis. To further elucidate the molecular mechanisms of RA effects, we determined the interaction between nuclear factor (NF)-κB and RA signaling. HG induced a sustained phosphorylation of IKK/IκBα and transcriptional activation of NF-κB in cardiomyocytes. Activated NF-κB signaling has an important role in HG-induced cardiomyocyte apoptosis and gene expression of interleukin-6 (IL-6), tumor necrosis factor (TNF)-α and monocyte chemoattractant protein-1 (MCP-1). All-trans RA (ATRA) and LGD1069, through activation of RAR/RXR-mediated signaling, inhibited the HG-mediated effects in cardiomyocytes. The inhibitory effect of RA on NF-κB activation was mediated through inhibition of IKK/IκBα phosphorylation. ATRA and LGD1069 treatment promoted protein phosphatase 2A (PP2A) activity, which was significantly suppressed by HG stimulation. The RA effects on IKK and IκBα were blocked by okadaic acid or silencing the expression of PP2Ac-subunit, indicating that the inhibitory effect of RA on NF-κB is regulated through activation of PP2A and subsequent dephosphorylation of IKK/IκBα. Moreover, ATRA and LGD1069 reversed the decreased PP2A activity and inhibited the activation of IKK/IκBα and gene expression of MCP-1, IL-6 and TNF-α in the hearts of Zucker diabetic fatty rats. In summary, our findings suggest that the suppressed activation of PP2A contributed to sustained activation of NF-κB in HG-stimulated cardiomyocytes; and that the protective effect of RA on hyperglycemia-induced cardiomyocyte apoptosis and inflammatory responses is partially regulated through activation of PP2A and suppression of NF-κB-mediated signaling and downstream targets. PMID:22718360

Distinct functional outputs of PTEN signalling are controlled by dynamic association with β-arrestins

PubMed Central

Lima-Fernandes, Evelyne; Enslen, Hervé; Camand, Emeline; Kotelevets, Larissa; Boularan, Cédric; Achour, Lamia; Benmerah, Alexandre; Gibson, Lucien C D; Baillie, George S; Pitcher, Julie A; Chastre, Eric; Etienne-Manneville, Sandrine; Marullo, Stefano; Scott, Mark G H

2011-01-01

The tumour suppressor PTEN (phosphatase and tensin deleted on chromosome 10) regulates major cellular functions via lipid phosphatase-dependent and -independent mechanisms. Despite its fundamental pathophysiological importance, how PTEN's cellular activity is regulated has only been partially elucidated. We report that the scaffolding proteins β-arrestins (β-arrs) are important regulators of PTEN. Downstream of receptor-activated RhoA/ROCK signalling, β-arrs activate the lipid phosphatase activity of PTEN to negatively regulate Akt and cell proliferation. In contrast, following wound-induced RhoA activation, β-arrs inhibit the lipid phosphatase-independent anti-migratory effects of PTEN. β-arrs can thus differentially control distinct functional outputs of PTEN important for cell proliferation and migration. PMID:21642958

Rebamipide suppresses diclofenac-induced intestinal permeability via mitochondrial protection in mice.

PubMed

Diao, Lei; Mei, Qiao; Xu, Jian-Ming; Liu, Xiao-Chang; Hu, Jing; Jin, Juan; Yao, Qiang; Chen, Mo-Li

2012-03-14

To investigate the protective effect and mechanism of rebamipide on small intestinal permeability induced by diclofenac in mice. Diclofenac (2.5 mg/kg) was administered once daily for 3 d orally. A control group received the vehicle by gavage. Rebamipide (100 mg/kg, 200 mg/kg, 400 mg/kg) was administered intragastrically once a day for 3 d 4 h after diclofenac administration. Intestinal permeability was evaluated by Evans blue and the FITC-dextran method. The ultrastructure of the mucosal barrier was evaluated by transmission electron microscopy (TEM). Mitochondrial function including mitochondrial swelling, mitochondrial membrane potential, mitochondrial nicotinamide adenine dinucleotide-reduced (NADH) levels, succinate dehydrogenase (SDH) and ATPase activities were measured. Small intestinal mucosa was collected for assessment of malondialdehyde (MDA) content and myeloperoxidase (MPO) activity. Compared with the control group, intestinal permeability was significantly increased in the diclofenac group, which was accompanied by broken tight junctions, and significant increases in MDA content and MPO activity. Rebamipide significantly reduced intestinal permeability, improved inter-cellular tight junctions, and was associated with decreases in intestinal MDA content and MPO activity. At the mitochondrial level, rebamipide increased SDH and ATPase activities, NADH level and decreased mitochondrial swelling. Increased intestinal permeability induced by diclofenac can be attenuated by rebamipide, which partially contributed to the protection of mitochondrial function.

Rebamipide suppresses diclofenac-induced intestinal permeability via mitochondrial protection in mice

PubMed Central

Diao, Lei; Mei, Qiao; Xu, Jian-Ming; Liu, Xiao-Chang; Hu, Jing; Jin, Juan; Yao, Qiang; Chen, Mo-Li

2012-01-01

AIM: To investigate the protective effect and mechanism of rebamipide on small intestinal permeability induced by diclofenac in mice. METHODS: Diclofenac (2.5 mg/kg) was administered once daily for 3 d orally. A control group received the vehicle by gavage. Rebamipide (100 mg/kg, 200 mg/kg, 400 mg/kg) was administered intragastrically once a day for 3 d 4 h after diclofenac administration. Intestinal permeability was evaluated by Evans blue and the FITC-dextran method. The ultrastructure of the mucosal barrier was evaluated by transmission electron microscopy (TEM). Mitochondrial function including mitochondrial swelling, mitochondrial membrane potential, mitochondrial nicotinamide adenine dinucleotide-reduced (NADH) levels, succinate dehydrogenase (SDH) and ATPase activities were measured. Small intestinal mucosa was collected for assessment of malondialdehyde (MDA) content and myeloperoxidase (MPO) activity. RESULTS: Compared with the control group, intestinal permeability was significantly increased in the diclofenac group, which was accompanied by broken tight junctions, and significant increases in MDA content and MPO activity. Rebamipide significantly reduced intestinal permeability, improved inter-cellular tight junctions, and was associated with decreases in intestinal MDA content and MPO activity. At the mitochondrial level, rebamipide increased SDH and ATPase activities, NADH level and decreased mitochondrial swelling. CONCLUSION: Increased intestinal permeability induced by diclofenac can be attenuated by rebamipide, which partially contributed to the protection of mitochondrial function. PMID:22416180

Clinical prognostic significance and pro-metastatic activity of RANK/RANKL via the AKT pathway in endometrial cancer.

PubMed

Wang, Jing; Liu, Yao; Wang, Lihua; Sun, Xiao; Wang, Yudong

2016-02-02

RANK/RANKL plays a key role in metastasis of certain malignant tumors, which makes it a promising target for developing novel therapeutic strategies for cancer. However, the prognostic value and pro-metastatic activity of RANK in endometrial cancer (EC) remain to be determined. Thus, the present study investigated the effect of RANK on the prognosis of EC patients, as well as the pro-metastatic activity of EC cells. The results indicated that those with high expression of RANK showed decreased overall survival and progression-free survival. Statistical analysis revealed the positive correlations between RANK/RANKL expression and metastasis-related factors. Additionally, RANK/RANKL significantly promoted cell migration/invasion via activating AKT/β-catenin/Snail pathway in vitro. However, RANK/RANKL-induced AKT activation could be suppressed after osteoprotegerin (OPG) treatment. Furthermore, the combination of medroxyprogesterone acetate (MPA) and RANKL could in turn attenuate the effect of RANKL alone. Similarly, MPA could partially inhibit the RANK-induced metastasis in an orthotopic mouse model via suppressing AKT/β-catenin/Snail pathway. Therefore, therapeutic inhibition of MPA in RANK/RANKL-induced metastasis was mediated by AKT/β-catenin/Snail pathway both in vitro and in vivo, suggesting a potential target of RANK for gene-based therapy for EC.

Extract of grapefruit-seed reduces acute pancreatitis induced by ischemia/reperfusion in rats: possible implication of tissue antioxidants.

PubMed

Dembinski, A; Warzecha, Z; Konturek, S J; Ceranowicz, P; Dembinski, M; Pawlik, W W; Kusnierz-Cabala, B; Naskalski, J W

2004-12-01

Grapefruit seed extract (GSE) has been shown to exert antibacterial, antifungal and antioxidant activity possibly due to the presence of naringenin, the flavonoid with cytoprotective action on the gastric mucosa. No study so far has been undertaken to determine whether this GSE is also capable of preventing acute pancreatic damage induced by ischemia/reperfusion (I/R), which is known to result from reduction of anti-oxidative capability of pancreatic tissue, and whether its possible preventive effect involves an antioxidative action of this biocomponent. In this study carried out on rats with acute hemorrhagic pancreatitis induced by 30 min partial pancreatic ischemia followed by 6 h of reperfusion, the GSE or vehicle (vegetable glycerin) was applied intragastrically in gradually increasing amounts (50-500 microl) 30 min before I/R. Pretreatment with GSE decreased the extent of pancreatitis with maximal protective effect of GSE at the dose 250 microl. GSE reduced the pancreatitis-evoked increase in serum lipase and poly-C specific ribonuclease activity, and attenuated the marked fall in pancreatic blood flow and pancreatic DNA synthesis. GSE administered alone increased significantly pancreatic tissue content of lipid peroxidation products, malondialdehyde and 4-hydroxyalkens, and when administered before I/R, GSE reduced the pancreatitis-induced lipid peroxidation. We conclude that GSE exerts protective activity against I/R-induced pancreatitis probably due to the activation of antioxidative mechanisms in the pancreas and the improvement of pancreatic blood flow.

Artocarpus altilis (Parkinson) Fosberg Extracts and Geranyl Dihydrochalcone Inhibit STAT3 Activity in Prostate Cancer DU145 Cells.

PubMed

Jeon, Yoon Jung; Jung, Seung-Nam; Chang, Hyeyoun; Yun, Jieun; Lee, Chang Woo; Lee, Joonku; Choi, Sangho; Nash, Oyekanmi; Han, Dong Cho; Kwon, Byoung-Mog

2015-05-01

Artocarpus altilis (Parkinson) Fosberg has traditionally been used in Indonesia for the treatment of liver cirrhosis, hypertension, and diabetes. In many other countries, it is used for the treatment of malaria, yellow fever, and dengue fever. It has been reported that A. altilis extracts have antiatherosclerotic and cytoprotective effects, but its molecular targets in tumor cells are not yet fully understood. The A. altilis extracts and the partially purified fraction have been shown to inhibit STAT3 activity and the phosphorylation of STAT3 in a dose-dependent manner. To identify the active components, a bioassay-guided isolation of the partially purified fraction resulted in the identification of a geranyl dihydrochalcone, CG901. Its chemical structure was established on the basis of spectroscopic evidence and comparison with published data. The partially purified fraction and the isolated a geranyl dihydrochalcone, CG901, down-regulated the expression of STAT3 target genes, induced apoptosis in DU145 prostate cancer cells via caspase-3 and PARP degradation, and inhibited tumor growth in human prostate tumor (DU145) xenograft initiation model. These results suggest that A. altilis could be a good natural source and that the isolated compound will be a potential lead molecule for developing novel therapeutics against STAT3-related diseases, including cancer and inflammation. Copyright © 2015 John Wiley & Sons, Ltd.

Neonatal testosterone partially organizes sex differences in stress-induced emotionality in mice.

PubMed

Seney, Marianne L; Walsh, Christopher; Stolakis, Ryan; Sibille, Etienne

2012-05-01

Major depressive disorder (MDD) is a debilitating disorder of altered mood regulation. Despite well established sex differences in MDD prevalence, the mechanism underlying the increased female vulnerability remains unknown. Although evidence suggests an influence of adult circulating hormone levels on mood (i.e. activational effects of hormones), MDD prevalence is consistently higher in women across life stages (and therefore hormonal states), suggesting that additional underlying structural or biological differences place women at higher risk. Studies in human subjects and in rodent models suggest a developmental origin for mood disorders, and interestingly, a developmental process also establishes sex differences in the brain. Hence, based on these parallel developmental trajectories, we hypothesized that a proportion of the female higher vulnerability to MDD may originate from the differential organization of mood regulatory neural networks early in life (i.e. organizational effects of hormones). To test this hypothesis in a rodent system, we took advantage of a well-established technique used in the field of sexual differentiation (neonatal injection with testosterone) to masculinize sexually dimorphic brain regions in female mice. We then investigated adult behavioral consequences relating to emotionality by comparing neonatal testosterone-treated females to normal males and females. Under baseline/trait conditions, neonatal testosterone treatment of female mice did not influence adult emotionality, but masculinized adult locomotor activity, as revealed by the activational actions of hormones. Conversely, the increased vulnerability of female mice to develop high emotionality following unpredictable chronic mild stress (UCMS) was partially masculinized by neonatal testosterone exposure, with no effect on post-UCMS locomotion. The elevated female UCMS-induced vulnerability did not differ between adult hormone treated groups. These results demonstrate that sex differences in adult emotionality in mice are partially caused by the organizational effects of sex hormones during development, hence supporting a developmental hypothesis of the human adult female prevalence of MDD. Copyright © 2012 Elsevier Inc. All rights reserved.

Neonatal testosterone partially organizes sex differences in stress-induced emotionality in mice

PubMed Central

Seney, Marianne L.; Walsh, Christopher; Stolakis, Ryan; Sibille, Etienne

2012-01-01

Major depressive disorder (MDD) is a debilitating disorder of altered mood regulation. Despite well established sex differences in MDD prevalence, the mechanism underlying the increased female vulnerability remains unknown. Although evidence suggests an influence of adult circulating hormone levels on mood (i.e. activational effects of hormones), MDD prevalence is consistently higher in women across life stages (and therefore hormonal states), suggesting that additional underlying structural or biological differences place women at higher risk. Studies in human subjects and in rodent models suggest a developmental origin for mood disorders, and interestingly, a developmental process also establishes sex differences in the brain. Hence, based on these parallel developmental trajectories, we hypothesized that a proportion of the female higher vulnerability to MDD may originate from the differential organization of mood regulatory neural networks early in life (i.e. organizational effects of hormones). To test this hypothesis in a rodent system, we took advantage of a well-established technique used in the field of sexual differentiation (neonatal injection with testosterone) to masculinize sexually dimorphic brain regions in female mice. We then investigated adult behavioral consequences relating to emotionality by comparing neonatal testosterone-treated females to normal males and females. Under baseline/trait conditions, neonatal testosterone treatment of female mice did not influence adult emotionality, but masculinized adult locomotor activity, as revealed by the activational actions of hormones. Conversely, the increased vulnerability of female mice to develop high emotionality following unpredictable chronic mild stress (UCMS) was partially masculinized by neonatal testosterone exposure, with no effect on post-UCMS locomotion. The elevated female UCMS-induced vulnerability did not differ between adult hormone treated groups. These results demonstrate that sex differences in adult emotionality in mice are partially caused by the organizational effects of sex hormones during development, hence supporting a developmental hypothesis of the human adult female prevalence of MDD. PMID:22394611

Antihyperalgesic effects of dexketoprofen and tramadol in a model of postoperative pain in mice - effects on glial cell activation.

PubMed

Romero-Alejo, Elizabeth; Puig, Margarita M; Romero, Asunción

2016-08-01

To define likely targets (i.e. glia) and protocols (analgesic combinations) to improve postoperative pain outcomes and reduce chronic pain after surgery. Specifically, to assess the antihyperalgesic effects of the dexketoprofen : tramadol (DEX : TRM) combination, exploring the implication of glial activation. In a mouse model of postincisional pain, we evaluated mechanical nociceptive thresholds (Von Frey) for 21 days postoperatively. We assessed DEX and TRM alone and combined (1 : 1 ratio) on postoperative hyperalgesia (POH, day 1) and delayed latent pain sensitisation (substantiated by a naloxone challenge; PS, day 21). The interactions were analysed using isobolograms, and concomitant changes in spinal glial cell activation were measured. On day 1, DEX completely blocked POH, whereas TRM induced 32% inhibition. TRM, but not DEX, partially (47%) protected against PS, at 21 days. Co-administration of DEX : TRM (1 : 1 ratio) showed additivity for antihyperalgesia. Both drugs and their combination totally inhibited surgery-induced microglia activation on day 1, but had no effect on surgery-induced astrocyte activation (1 day) or re-activation after naloxone (21 days). The DEX : TRM combination could have clinical advantages: a complete prevention of POH after surgery, together with a substantial (48%) inhibition of the development of PS by TRM. Microglia, but not astrocyte activation, could play a relevant role in the development of postoperative pain hypersensitivity. © 2016 Royal Pharmaceutical Society.

Carbachol-induced colonic mucus formation requires transport via NKCC1, K+ channels and CFTR

PubMed Central

Lindén, Sara K.; Alwan, Ala H.; Scholte, Bob J.; Hansson, Gunnar C.; Sjövall, Henrik

2016-01-01

The colonic mucosa protects itself from the luminal content by secreting mucus that keeps the bacteria at a distance from the epithelium. For this barrier to be effective, the mucus has to be constantly replenished which involves exocytosis and expansion of the secreted mucins. Mechanisms involved in regulation of mucus exocytosis and expansion are poorly understood, and the aim of this study was to investigate whether epithelial anion secretion regulates mucus formation in the colon. The muscarinic agonist carbachol was used to induce parallel secretion of anions and mucus, and by using established inhibitors of ion transport, we studied how inhibition of epithelial transport affected mucus formation in mouse colon. Anion secretion and mucin exocytosis were measured by changes in membrane current and epithelial capacitance, respectively. Mucus thickness measurements were used to determine the carbachol effect on mucus growth. The results showed that the carbachol-induced increase in membrane current was dependent on NKCC1 co-transport, basolateral K+ channels and Cftr activity. In contrast, the carbachol-induced increase in capacitance was partially dependent on NKCC1 and K+ channel activity, but did not require Cftr activity. Carbachol also induced an increase in mucus thickness that was inhibited by the NKCC1 blocker bumetanide. However, mice that lacked a functional Cftr channel did not respond to carbachol with an increase in mucus thickness, suggesting that carbachol-induced mucin expansion requires Cftr channel activity. In conclusion, these findings suggest that colonic epithelial transport regulates mucus formation by affecting both exocytosis and expansion of the mucin molecules. PMID:25139191

Carbachol-induced colonic mucus formation requires transport via NKCC1, K⁺ channels and CFTR.

PubMed

Gustafsson, Jenny K; Lindén, Sara K; Alwan, Ala H; Scholte, Bob J; Hansson, Gunnar C; Sjövall, Henrik

2015-07-01

The colonic mucosa protects itself from the luminal content by secreting mucus that keeps the bacteria at a distance from the epithelium. For this barrier to be effective, the mucus has to be constantly replenished which involves exocytosis and expansion of the secreted mucins. Mechanisms involved in regulation of mucus exocytosis and expansion are poorly understood, and the aim of this study was to investigate whether epithelial anion secretion regulates mucus formation in the colon. The muscarinic agonist carbachol was used to induce parallel secretion of anions and mucus, and by using established inhibitors of ion transport, we studied how inhibition of epithelial transport affected mucus formation in mouse colon. Anion secretion and mucin exocytosis were measured by changes in membrane current and epithelial capacitance, respectively. Mucus thickness measurements were used to determine the carbachol effect on mucus growth. The results showed that the carbachol-induced increase in membrane current was dependent on NKCC1 co-transport, basolateral K(+) channels and Cftr activity. In contrast, the carbachol-induced increase in capacitance was partially dependent on NKCC1 and K(+) channel activity, but did not require Cftr activity. Carbachol also induced an increase in mucus thickness that was inhibited by the NKCC1 blocker bumetanide. However, mice that lacked a functional Cftr channel did not respond to carbachol with an increase in mucus thickness, suggesting that carbachol-induced mucin expansion requires Cftr channel activity. In conclusion, these findings suggest that colonic epithelial transport regulates mucus formation by affecting both exocytosis and expansion of the mucin molecules.

Concerted action of p62 and Nrf2 protects cells from palmitic acid-induced lipotoxicity

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

Park, Jeong Su; Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752; Kang, Dong Hoon

Nonalcoholic fatty liver disease (NAFLD), frequently associated with obesity and diabetes mellitus, is caused by the accumulation of excess fatty acids within liver cells. Palmitic acid (PA), a common saturated fatty acid found in mammals, induces the generation of reactive oxygen species (ROS) and elicits apoptotic cell death, known as lipotoxicity. However, protective mechanisms against PA-induced lipotoxicity have not been elucidated. In this study, we aimed to clarify the role of p62, an adapter protein in the autophagic process, as well as the nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway, in protecting cells from PA-inducedmore » lipotoxicity. The Nrf2-Keap1 pathway is essential for the protection of cells from oxidative stress. p62 enhances its binding to Keap1 and leads to Nrf2 activation. Here, we show that PA potentiates Keap1 degradation and thereby activates the transcription of Nrf2 target genes partially through autophagy. Furthermore, this PA-mediated Keap1 degradation depends on p62. Correspondingly, a lack of p62 attenuates the PA-mediated Nrf2 activation and increases the susceptibility of cells to oxidative stress. These results indicate that p62 plays an important role in protecting cells against lipotoxicity through Keap1 degradation-mediated Nrf2 activation. - Highlights: • PA induces Keap1 downregulation and activates Nrf2 target gene transcription. • PA-induced Keap1 degradation is partly mediated by the autophagic pathway. • PA-induced Keap1 degradation depends on p62. • Ablation of p62 exacerbates PA-mediated apoptotic cell death.« less

Evidence that N-acetylcysteine inhibits TNF-alpha-induced cerebrovascular endothelin-1 upregulation via inhibition of mitogen- and stress-activated protein kinase.

PubMed

Sury, Matthias D; Frese-Schaper, Manuela; Mühlemann, Miranda K; Schulthess, Fabienne T; Blasig, Ingolf E; Täuber, Martin G; Shaw, Sidney G; Christen, Stephan

2006-11-01

N-acetylcysteine (NAC) is neuroprotective in animal models of acute brain injury such as caused by bacterial meningitis. However, the mechanism(s) by which NAC exerts neuroprotection is unclear. Gene expression of endothelin-1 (ET-1), which contributes to cerebral blood flow decline in acute brain injury, is partially regulated by reactive oxygen species, and thus a potential target of NAC. We therefore examined the effect of NAC on tumor necrosis factor (TNF)-alpha-induced ET-1 production in cerebrovascular endothelial cells. NAC dose dependently inhibited TNF-alpha-induced preproET-1 mRNA upregulation and ET-1 protein secretion, while upregulation of inducible nitric oxide synthase (iNOS) was unaffected. Intriguingly, NAC had no effect on the initial activation (i.e., IkappaB degradation, nuclear p65 translocation, and Ser536 phosphorylation) of NF-kappaB by TNF-alpha. However, transient inhibition of NF-kappaB DNA binding suggested that NAC may inhibit ET-1 upregulation by inhibiting (a) parallel pathway(s) necessary for full transcriptional activation of NF-kappaB-mediated ET-1 gene expression. Similar to NAC, the MEK1/2 inhibitor U0126, the p38 inhibitor SB203580, and the protein kinase inhibitor H-89 selectively inhibited ET-1 upregulation without affecting nuclear p65 translocation, suggesting that NAC inhibits ET-1 upregulation via inhibition of mitogen- and stress-activated protein kinase (MSK). Supporting this notion, cotreatment with NAC inhibited the TNF-alpha-induced rise in MSK1 and MSK2 kinase activity, while siRNA knock-down experiments showed that MSK2 is the predominant isoform involved in TNF-alpha-induced ET-1 upregulation.

CXCR4 Chemokine Receptor Signaling Induces Apoptosis in Acute Myeloid Leukemia Cells via Regulation of the Bcl-2 Family Members Bcl-XL, Noxa, and Bak*

PubMed Central

Kremer, Kimberly N.; Peterson, Kevin L.; Schneider, Paula A.; Meng, X. Wei; Dai, Haiming; Hess, Allan D.; Smith, B. Douglas; Rodriguez-Ramirez, Christie; Karp, Judith E.; Kaufmann, Scott H.; Hedin, Karen E.

2013-01-01

The CXCR4 chemokine receptor promotes survival of many different cell types. Here, we describe a previously unsuspected role for CXCR4 as a potent inducer of apoptosis in acute myeloid leukemia (AML) cell lines and a subset of clinical AML samples. We show that SDF-1, the sole ligand for CXCR4, induces the expected migration and ERK activation in the KG1a AML cell line transiently overexpressing CXCR4, but ERK activation did not lead to survival. Instead, SDF-1 treatment led via a CXCR4-dependent mechanism to apoptosis, as evidenced by increased annexin V staining, condensation of chromatin, and cleavage of both procaspase-3 and PARP. This SDF-1-induced death pathway was partially inhibited by hypoxia, which is often found in the bone marrow of AML patients. SDF-1-induced apoptosis was inhibited by dominant negative procaspase-9 but not by inhibition of caspase-8 activation, implicating the intrinsic apoptotic pathway. Further analysis showed that this pathway was activated by multiple mechanisms, including up-regulation of Bak at the level of mRNA and protein, stabilization of the Bak activator Noxa, and down-regulation of antiapoptotic Bcl-XL. Furthermore, adjusting expression levels of Bak, Bcl-XL, or Noxa individually altered the level of apoptosis in AML cells, suggesting that the combined modulation of these family members by SDF-1 coordinates their interplay to produce apoptosis. Thus, rather than mediating survival, SDF-1 may be a means to induce apoptosis of CXCR4-expressing AML cells directly in the SDF-1-rich bone marrow microenvironment if the survival cues of the bone marrow are disrupted. PMID:23798675

Artesunate protects pancreatic beta cells against cytokine-induced damage via SIRT1 inhibiting NF-κB activation.

PubMed

Yu, L; Chen, J F; Shuai, X; Xu, Y; Ding, Y; Zhang, J; Yang, W; Liang, X; Su, D; Yan, C

2016-01-01

Artesunate (ART) has been known as the most effective and safe reagents to treat malaria for many years. In this study, we explored whether ART could protect pancreatic beta-cell against cytokine-induced damage. The production of nitrite (NO) was detected with the Griess Assay Kit. SIRT1 and inducible nitric oxide synthase (iNOS) expression were determined with Western blot. The transcriptional activity of NF-κB was evaluated by luciferase reporter assay. The expression of Sirt1 was silenced by RNA interference. Glucose-stimulated insulin secretion (GSIS) and potassium-stimulated insulin secretion (KSIS) assays were performed to measure the effect of ART on pancreatic beta-cells' function. The effect of ART on beta-cells apoptosis was evaluated by using Hochest/PI staining and TUNEL assay. ART enhanced GSIS (KSIS) and reduced apoptosis of pancreatic beta-cells induced by IL-1β. Further study showed that ART inhibited IL-1β-induced increase of NF-κB activity, iNOS expression, and NO production. Moreover, ART up-regulated SIRT1 expression in INS-1 cells and islets exposed to IL-1β. Inhibition of SIRT1 expression could partially abolished the inhibitory effect of ART on NF-κB activity in IL-1β-treated beta-cells. More importantly, the protective effect of ART on cytokine-induced damage was reversed by silencing SIRT1 expression. ART can elicit a protective effect on beta-cells exposed to IL-1β by stimulating SIRT1 expression, which resulted in the decrease of NF-κB activity, iNOS expression, and NO production. Hence, ART might be an effective drug for diabetes.

Telmisartan prevented cognitive decline partly due to PPAR-{gamma} activation

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

Mogi, Masaki; Li Jianmei; Tsukuda, Kana

Telmisartan is a unique angiotensin receptor blocker (ARB) and partial agonist of peroxisome proliferator-activated receptor (PPAR)-{gamma}. Here, we investigated the preventive effect of telmisartan on cognitive decline in Alzheimer disease. In ddY mice, intracerebroventricular injection of A{beta} 1-40 significantly attenuated their cognitive function evaluated by shuttle avoidance test. Pretreatment with a non-hypotensive dose of telmisartan significantly inhibited such cognitive decline. Interestingly, co-treatment with GW9662, a PPAR-{gamma} antagonist, partially inhibited this improvement of cognitive decline. Another ARB, losartan, which has less PPAR-{gamma} agonistic effect, also inhibited A{beta}-injection-induced cognitive decline; however the effect was smaller than that of telmisartan and was notmore » affected by GW9662. Immunohistochemical staining for A{beta} showed the reduced A{beta} deposition in telmisartan-treated mice. However, this reduction was not observed in mice co-administered GW9662. These findings suggest that ARB has a preventive effect on cognitive impairment in Alzheimer disease, and telmisartan, with PPAR-{gamma} activation, could exert a stronger effect.« less

Effect of Syzygium cumini and Bauhinia forficata aqueous-leaf extracts on oxidative and mitochondrial parameters in vitro

PubMed Central

Ecker, Assis; Araujo Vieira, Francielli; de Souza Prestes, Alessandro; Mulling dos Santos, Matheus; Ramos, Angelica; Dias Ferreira, Rafael; Teixeira de Macedo, Gabriel; Vargas Klimaczewski, Claudia; Lopes Seeger, Rodrigo; Teixeira da Rocha, João Batista; de Vargas Barbosa, Nilda B.

2015-01-01

Aqueous-leaf extract of Syzygium cumini and Bauhinia forficata are traditionally used in the treatment of diabetes and cancer, especially in South America, Africa, and Asia. In this study, we analyzed the effects of these extracts on oxidative and mitochondrial parameters in vitro, as well as their protective activities against toxic agents. Phytochemical screenings of the extracts were carried out by HPLC analysis. The in vitro antioxidant capacities were compared by DPPH radical scavenging and Fe2+ chelating activities. Mitochondrial parameters observed were swelling, lipid peroxidation and dehydrogenase activity. The major chemical constituent of S. cumini was rutin. In B. forficata were predominant quercetin and gallic acid. S. cumini reduced DPPH radical more than B. forficata, and showed iron chelating activity at all tested concentrations, while B. forficata had not similar property. In mitochondria, high concentrations of B. forficata alone induced a decrease in mitochondrial dehydrogenase activity, but low concentrations of this extract prevented the effect induced by Fe2++H2O2. This was also observed with high concentrations of S. cumini. Both extracts partially prevented the lipid peroxidation induced by Fe2+/citrate. S. cumini was effective against mitochondrial swelling induced by Ca2+, while B. forficata alone induced swelling more than Ca2+. This study suggests that leaf extract of S. cumini might represent a useful therapeutic for the treatment of diseases related with mitochondrial dysfunctions. On the other hand, the consumption of B. forficata should be avoided because mitochondrial damages were observed, and this possibly may pose risk to human health. PMID:27152111

Pancreas anatomy and surgical procedure for pancreatectomy in rhesus monkeys.

PubMed

Zhang, Yi; Fu, Lan; Lu, Yan-Rong; Guo, Zhi-Guang; Zhang, Zhao-Da; Cheng, Jing-Qiu; Hu, Wei-Ming; Liu, Xu-Bao; Mai, Gang; Zeng, Yong; Tian, Bo-Le

2011-12-01

The aim of this study was to investigate the pancreas anatomy and surgical procedure for harvesting pancreas for islet isolation while performing pancreatectomy to induce diabetes in rhesus monkeys. The necropsy was performed in three cadaveric monkeys. Two monkeys underwent the total pancreatectomy and four underwent partial pancreatectomy (70-75%). The greater omentum without ligament to transverse colon, the cystic artery arising from the proper hepatic artery and the branches supplying the paries posterior gastricus from the splenic artery were observed. For pancreatectomy, resected pancreas can be used for islet isolation. Diabetes was not induced in the monkeys undergoing partial pancreatectomy (70-75%). Pancreas anatomy in rhesus monkeys is not the same as in human. Diabetes can be induced in rhesus monkeys by total but not partial pancreatectomy (70-75%). Resected pancreas can be used for islet isolation while performing pancreatectomy to induce diabetes. © 2011 John Wiley & Sons A/S.

A calmodulin binding protein from Arabidopsis is induced by ethylene and contains a DNA-binding motif

NASA Technical Reports Server (NTRS)

Reddy, A. S.; Reddy, V. S.; Golovkin, M.

2000-01-01

Calmodulin (CaM), a key calcium sensor in all eukaryotes, regulates diverse cellular processes by interacting with other proteins. To isolate CaM binding proteins involved in ethylene signal transduction, we screened an expression library prepared from ethylene-treated Arabidopsis seedlings with 35S-labeled CaM. A cDNA clone, EICBP (Ethylene-Induced CaM Binding Protein), encoding a protein that interacts with activated CaM was isolated in this screening. The CaM binding domain in EICBP was mapped to the C-terminus of the protein. These results indicate that calcium, through CaM, could regulate the activity of EICBP. The EICBP is expressed in different tissues and its expression in seedlings is induced by ethylene. The EICBP contains, in addition to a CaM binding domain, several features that are typical of transcription factors. These include a DNA-binding domain at the N terminus, an acidic region at the C terminus, and nuclear localization signals. In database searches a partial cDNA (CG-1) encoding a DNA-binding motif from parsley and an ethylene up-regulated partial cDNA from tomato (ER66) showed significant similarity to EICBP. In addition, five hypothetical proteins in the Arabidopsis genome also showed a very high sequence similarity with EICBP, indicating that there are several EICBP-related proteins in Arabidopsis. The structural features of EICBP are conserved in all EICBP-related proteins in Arabidopsis, suggesting that they may constitute a new family of DNA binding proteins and are likely to be involved in modulating gene expression in the presence of ethylene.

Mechanism of Telomerase Activation by v-Rel and Its Contribution to Transformation

PubMed Central

Hrdličková, Radmila; Nehyba, Jiří; Liss, Andrew S.; Bose, Henry R.

2006-01-01

Telomerase is activated during the transformation of lymphoid cells and fibroblasts by v-Rel, the oncogenic member of the Rel/NF-κB family of transcription factors. v-Rel-transformed cell lines have longer telomeres than untransformed chicken lymphoid cells and have high levels of telomerase activity. v-Rel-mediated activation of telomerase is achieved by multiple mechanisms. The expression of the gene encoding the catalytic subunit of telomerase (TERT) was directly upregulated by v-Rel. Moreover, the expression of v-Rel altered the ratio of alternatively spliced and full-length TERT transcripts in favor of the full-length forms. The activation of telomerase by v-Rel in lymphocytes was also accompanied by inactivation of nuclear inhibitors. The inhibition of telomerase activity in v-Rel-transformed cell lines led to apoptosis within 24 h. The expression of v-Rel in a macrophage cell line resulted in elevated levels of reactive oxygen species (ROS), increased telomerase activity, and increased sensitivity to telomerase inhibitors. In contrast, the ectopic expression of TERT decreased the extent of apoptosis induced by ROS. The activation of telomerase by v-Rel may, therefore, partially protect the transformed cells from apoptosis induced by ROS. PMID:16352553

Effects of Natural Products on Fructose-Induced Nonalcoholic Fatty Liver Disease (NAFLD).

PubMed

Chen, Qian; Wang, Tingting; Li, Jian; Wang, Sijian; Qiu, Feng; Yu, Haiyang; Zhang, Yi; Wang, Tao

2017-01-31

As a sugar additive, fructose is widely used in processed foods and beverages. Excessive fructose consumption can cause hepatic steatosis and dyslipidemia, leading to the development of metabolic syndrome. Recent research revealed that fructose-induced nonalcoholic fatty liver disease (NAFLD) is related to several pathological processes, including: (1) augmenting lipogenesis; (2) leading to mitochondrial dysfunction; (3) stimulating the activation of inflammatory pathways; and (4) causing insulin resistance. Cellular signaling research indicated that partial factors play significant roles in fructose-induced NAFLD, involving liver X receptor (LXR)α, sterol regulatory element binding protein (SREBP)-1/1c, acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), peroxisome proliferator-activated receptor α (PPARα), leptin nuclear factor-erythroid 2-related factor 2 (Nrf2), nuclear factor kappa B (NF-κB), tumor necrosis factor α (TNF-α), c-Jun amino terminal kinase (JNK), phosphatidylinositol 3-kinase (PI3K) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Until now, a series of natural products have been reported as regulators of NAFLD in vivo and in vitro. This paper reviews the natural products (e.g., curcumin, resveratrol, and (-)-epicatechin) and their mechanisms of ameliorating fructose-induced NAFLD over the past years. Although, as lead compounds, natural products usually have fewer activities compared with synthesized compounds, it will shed light on studies aiming to discover new drugs for NAFLD.

Fermented wheat powder induces the antioxidant and detoxifying system in primary rat hepatocytes.

PubMed

La Marca, Margherita; Beffy, Pascale; Pugliese, Annalisa; Longo, Vincenzo

2013-01-01

Many plants exhibit antioxidant properties which may be useful in the prevention of oxidative stress reactions, such as those mediated by the formation of free radical species in different pathological situations. In recent years a number of studies have shown that whole grain products in particular have strong antioxidant activity. Primary cultures of rat hepatocytes were used to investigate whether and how a fermented powder of wheat (Lisosan G) is able to modulate antioxidant and detoxifying enzymes, and whether or not it can activate Nrf2 transcription factor or inhibit NF-kB activation. All of the antioxidant and detoxifying enzymes studied were significantly up-regulated by 0.7 mg/ml Lisosan G treatment. In particular, quinone oxidoreductase and heme oxygenase-1 were induced, although to different degrees, at the transcriptional, protein and/or activity levels by the treatment. As for the Nrf2 transcription factor, a partial translocation of its protein from the cytosol to the nucleus after 1 h of Lisosan G treatment was revealed by immunoblotting. Lisosan G was also observed to decrease H2O2-induced toxicity Taken together, these results show that this powder of wheat is an effective inducer of ARE/Nrf2-regulated antioxidant and detoxifying genes and has the potential to inhibit the translocation of NF-kB into the nucleus.

Inhibition of Rat 5α-Reductase Activity and Testosterone-Induced Sebum Synthesis in Hamster Sebocytes by an Extract of Quercus acutissima Cortex

PubMed Central

Koseki, Junichi; Matsumoto, Takashi; Matsubara, Yosuke; Tsuchiya, Kazuaki; Mizuhara, Yasuharu; Sekiguchi, Kyoji; Nishimura, Hiroaki; Watanabe, Junko; Kaneko, Atsushi; Hattori, Tomohisa; Maemura, Kazuya; Kase, Yoshio

2015-01-01

Objective. Bokusoku (BK) is an extract from the Quercus cortex used in folk medicine for treatment of skin disorders and convergence, and is present in jumihaidokuto, a traditional Japanese medicine that is prescribed for purulent skin diseases like acne vulgaris. The excess of sebum production induced by androgen is involved in the development of acne. Our aim is to examine whether BK and its constituents inhibit testosterone metabolism and testosterone-induced sebum synthesis. Methods. Measurements of 5α-reductase activity and lipogenesis were performed using rat liver microsomes and hamster sebocytes, respectively. Results. BK dose-dependently reduced the conversion of testosterone to a more active androgen, dihydrotestosterone in a 5α-reductase enzymatic reaction. Twenty polyphenols in BK categorized as gallotannin, ellagitannin, and flavonoid were identified by LC-MS/MS. Nine polyphenols with gallate group, tetragalloyl glucose, pentagalloyl glucose, eugeniin, 1-desgalloyl eugeniin, casuarinin, castalagin, stenophyllanin C, (−)-epicatechin gallate, and (−)-epigallocatechin gallate, inhibited testosterone metabolism. In particular, pentagalloyl glucose showed the strongest activity. BK and pentagalloyl glucose suppressed testosterone-induced lipogenesis, whereas they weakly inhibited the lipogenic action of insulin. Conclusions. BK inhibited androgen-related pathogenesis of acne, testosterone conversion, and sebum synthesis, partially through 5α-reductase inhibition, and has potential to be a useful agent in the therapeutic strategy of acne. PMID:25709710

DNA damage, lysosomal degradation and Bcl-xL deamidation in doxycycline- and minocycline-induced cell death in the K562 leukemic cell line.

PubMed

Fares, Mona; Abedi-Valugerdi, Manuchehr; Hassan, Moustapha; Potácová, Zuzana

2015-07-31

We investigated mechanisms of cytotoxicity induced by doxycycline (doxy) and minocycline (mino) in the chronic myeloid leukemia K562 cell line. Doxy and mino induced cell death in exposure-dependent manner. While annexin V/propidium iodide staining was consistent with apoptosis, the morphological changes in Giemsa staining were more equivocal. A pancaspase inhibitor Z-VAD-FMK partially reverted cell death morphology, but concurrently completely prevented PARP cleavage. Mitochondrial involvement was detected as dissipation of mitochondrial membrane potential and cytochrome C release. DNA double strand breaks detected with γH2AX antibody and caspase-2 activation were found early after the treatment start, but caspase-3 activation was a late event. Decrement of Bcl-xL protein levels and electrophoretic shift of Bcl-xL molecule were induced by both drugs. Phosphorylation of Bcl-xL at serine 62 was ruled out. Similarly, Bcr/Abl tyrosine kinase levels were decreased. Lysosomal inhibitor chloroquine restored Bcl-xL and Bcr/Abl protein levels and inhibited caspase-3 activation. Thus, the cytotoxicity of doxy and mino in K562 cells is mediated by DNA damage, Bcl-xL deamidation and lysosomal degradation with activation of mitochondrial pathway of apoptosis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

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

Feng, Xue; Li, Ling; Jiang, Hong

Highlights: • Phosphorylation of mTOR is abnormal activation in SKOV3/DDP ovarian cancer cells. • Downregulation of mTOR by DHA helps to sensitize the SKOV3/DDP cells to chemotherapy. • DHA has the potential of induce autophagy in cancer cells. - Abstract: Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistantmore » human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells.« less

Antioxidant effect of a fermented powder of Lady Joy bean in primary rat hepatocytes.

PubMed

La Marca, Margherita; Pucci, Laura; Bollini, Roberto; Russo, Rossella; Sparvoli, Francesca; Gabriele, Morena; Longo, Vincenzo

2015-03-01

The role and beneficial effects of plant and food extracts against various diseases induced by oxidative stress have received much attention in recent years. Legumes are rich in bioactive compounds, and some studies suggest a correlation between their consumption and a reduced incidence of diseases. Primary cultures of rat hepatocytes were used to investigate whether and how an extract obtained from a fermented powder of bean named Lady Joy (Phaseolus vulgaris L.) is able to regulate antioxidant and detoxifying enzymes through the NRF2 pathway, inhibit NF-kB activation, and reduce H2O2-induced endoplasmic reticulum (ER) stress. All of the antioxidant and detoxifying enzymes studied were significantly up-regulated by Lady Joy treatment. Western blot showed that Nrf2 was activated by Lady Joy treatment. Also, cells treated with this fermented bean were partially protected against NF-kB activation resulting from H2O2 stress. As a link between oxidative stress and ER dysfunction is hypothesized, we verified whether Lady Joy was able to protect cells from H2O2-induced ER stress, by studying the response of the proteins CHOP, BiP and caspase 12. The results of this study show that Lady Joy can induce the Nrf2 pathway, inhibit NF-kB, and protect ER from stress induced by H2O2.

Expression and Activity of Nitric Oxide Synthase Isoforms in Methamphetamine-Induced Striatal Dopamine Toxicity

PubMed Central

Friend, Danielle M.; Son, Jong H.; Keefe, Kristen A.

2013-01-01

Nitric oxide is implicated in methamphetamine (METH)-induced neurotoxicity; however, the source of the nitric oxide has not been identified. Previous work has also revealed that animals with partial dopamine loss induced by a neurotoxic regimen of methamphetamine fail to exhibit further decreases in striatal dopamine when re-exposed to methamphetamine 7–30 days later. The current study examined nitric oxide synthase expression and activity and protein nitration in striata of animals administered saline or neurotoxic regimens of methamphetamine at postnatal days 60 and/or 90, resulting in four treatment groups: Saline:Saline, METH:Saline, Saline:METH, and METH:METH. Acute administration of methamphetamine on postnatal day 90 (Saline:METH and METH:METH) increased nitric oxide production, as evidenced by increased protein nitration. Methamphetamine did not, however, change the expression of endothelial or inducible isoforms of nitric oxide synthase, nor did it change the number of cells positive for neuronal nitric oxide synthase mRNA expression or the amount of neuronal nitric oxide synthase mRNA per cell. However, nitric oxide synthase activity in striatal interneurons was increased in the Saline:METH and METH:METH animals. These data suggest that increased nitric oxide production after a neurotoxic regimen of methamphetamine results from increased nitric oxide synthase activity, rather than an induction of mRNA, and that constitutively expressed neuronal nitric oxide synthase is the most likely source of nitric oxide after methamphetamine administration. Of interest, animals rendered resistant to further methamphetamine-induced dopamine depletions still show equivalent degrees of methamphetamine-induced nitric oxide production, suggesting that nitric oxide production alone in response to methamphetamine is not sufficient to induce acute neurotoxic injury. PMID:23230214

Assessment of the microscreen phage-induction assay for screening hazardous wastes (1989)

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

Houk, V.S.; DeMarini, D.M.

1989-01-01

The Microscreen phage-induction assay, which quantitatively measures the induction of prophage Lambda in Escherichia coli WP2s(Lambda), was used to test 14 crude (unfractionated) hazardous industrial-waste samples for genotoxic activity in the presence and absence of metabolic activation. Eleven of the 14 wastes induced prophage, and induction was observed at concentrations as low as 0.4 picograms per ml. Comparisons of the mutagenic activity of these waste samples in Salmonella and their ability to induce prophage Lambda indicate that the phage-induction assay was a more-sensitive indicator of genetic damage for this group of wastes. All but one of the wastes that weremore » mutagenic to Salmonella were detected by the phage-induction assay, and 5 wastes not mutagenic to Salmonella were genetically active in the phage assay. The enhanced ability of the phage-induction assay to detect genotoxic activity may be related to the constituents comprising these waste samples. Partial chemical characterizations of the wastes showed high concentrations of carcinogenic metals, solvents, and chlorinated compounds, most of which are detected poorly by the Salmonella assay.« less

Novel thrombolytic protease from edible and medicinal plant Aster yomena (Kitam.) Honda with anticoagulant activity: purification and partial characterization.

PubMed

Choi, Jun-Hui; Kim, Dae-Won; Park, Se-Eun; Choi, Bong-Suk; Sapkota, Kumar; Kim, Seung; Kim, Sung-Jun

2014-10-01

A thrombolytic protease named kitamase possessing anticoagulant property was purified from edible and medicinal plant Aster yomena (Kitam.) Honda. Kitamase showed a molecular weight of 50 kDa by SDS-PAGE and displayed a strong fibrin zymogram lysis band corresponding to the similar molecular mass. The enzyme was active at high temperatures (50°C). The fibrinolytic activity of kitamase was strongly inhibited by EDTA, EGTA, TPCK and PMSF, inhibited by Zn(2+). The Km and Vmax values for substrate S-2251 were determined as 4.31 mM and 23.81 mM/mg respectively. It dissolved fibrin clot directly and specifically cleaved the α, Aα and γ-γ chains of fibrin and fibrinogen. In addition, kitamase delayed the coagulation time and increased activated partial thromboplastin time and prothrombin time. Kitamase exerted a significant protective effect against collagen and epinephrine induced pulmonary thromboembolism in mice. These results suggest that kitamase may have the property of metallo-protease like enzyme, novel fibrino(geno)lytic enzyme and a potential to be a therapeutic agent for thrombosis. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Isolation of nine gene sequences induced by silica in murine macrophages

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

Segade, F.; Claudio, E.; Wrobel, K.

1995-03-01

Macrophage activation by silica is the initial step in the development of silicosis. To identify genes that might be involved in silica-mediated activation, RAW 264.7 mouse macrophages were treated with silica for 48 h, and a subtracted cDNA library enriched for silica-induced genes (SIG) was constructed and differently screened. Nine cDNA clones (designated SIG-12, -14, -20, -41, -61, -81, -91, and -111) were partially sequenced and compared with sequences in GenBank/EMBL databases. SIG-12, -14, and -20 corresponded to the genes for ribosomal proteins L13A, L32, and L26, respectively. SIG-61 is the mouse homologue of p21 RhoC. SIG-91 is identical tomore » the 67-kDa high-affinity laminin receptor. Four genes were not identified and are novel. All of the mRNAs corresponding to the nine cloned cDNAs were inducible by silica. Steady-state levels of mRNAs in RAW 264.7 cells treated with various macrophage activators and inducers of signal transduction pathways were determined. A complex pattern of induction and repression was found, indicating that upon phagocytosis of silica particles, many regulatory mechanisms of genes expression are simultaneously triggered. 55 refs., 4 figs., 1 tab.« less

Yersinia YopP-induced apoptotic cell death in murine dendritic cells is partially independent from action of caspases and exhibits necrosis-like features.

PubMed

Gröbner, Sabine; Autenrieth, Stella E; Soldanova, Irena; Gunst, Dani S J; Schaller, Martin; Bohn, Erwin; Müller, Steffen; Leverkus, Martin; Wesselborg, Sebastian; Autenrieth, Ingo B; Borgmann, Stefan

2006-11-01

Yersinia outer protein P (YopP) is a virulence factor of Yersinia enterocolitica that is injected into the cytosol of host cells where it targets MAP kinase kinases (MKKs) and inhibitor of kappaB kinase (IKK)-beta resulting in inhibition of cytokine production as well as induction of apoptosis in murine macrophages and dendritic cells (DC). Here we show that DC death was only partially prevented by the broad spectrum caspase inhibitor zVAD-fmk, indicating simultaneous caspase-dependent and caspase-independent mechanisms of cell death induction by YopP. Microscopic analyses and measurement of cell size demonstrated necrosis-like morphology of caspase-independent cell death. Application of zVAD-fmk prevented cleavage of procaspases and Bid, decrease of the inner transmembrane mitochondrial potential DeltaPsi(m) and mitochondrial release of cytochrome c. From these data we conclude that YopP-induced activation of the mitochondrial death pathway is mediated upstream via caspases. In conclusion, our results suggest that YopP simultaneously induces caspase-dependent apoptotic and caspase-independent necrosis-like death in DC. However, it has to be resolved if necrosis-like DC death occurs independently from apoptotic events or as an apoptotic epiphenomenon.

Accessory proteins 8b and 8ab of severe acute respiratory syndrome coronavirus suppress the interferon signaling pathway by mediating ubiquitin-dependent rapid degradation of interferon regulatory factor 3.

PubMed

Wong, Hui Hui; Fung, To Sing; Fang, Shouguo; Huang, Mei; Le, My Tra; Liu, Ding Xiang

2018-02-01

Severe acute respiratory syndrome coronavirus (SARS-CoV) is an inefficient inducer of interferon (IFN) response. It expresses various proteins that effectively circumvent IFN production at different levels via distinct mechanisms. Through the construction of recombinant IBV expressing proteins 8a, 8b and 8ab encoded by SARS-CoV ORF8, we demonstrate that expression of 8b and 8ab enables the corresponding recombinant viruses to partially overcome the inhibitory actions of IFN activation to achieve higher replication efficiencies in cells. We also found that proteins 8b and 8ab could physically interact with IRF3. Overexpression of 8b and 8ab resulted in the reduction of poly (I:C)-induced IRF3 dimerization and inhibition of the IFN-β signaling pathway. This counteracting effect was partially mediated by protein 8b/8ab-induced degradation of IRF3 in a ubiquitin-proteasome-dependent manner. Taken together, we propose that SARS-CoV may exploit the unique functions of proteins 8b and 8ab as novel mechanisms to overcome the effect of IFN response during virus infection. Copyright © 2017 Elsevier Inc. All rights reserved.

PAR-2 activation enhances weak acid-induced ATP release through TRPV1 and ASIC sensitization in human esophageal epithelial cells.

PubMed

Wu, Liping; Oshima, Tadayuki; Shan, Jing; Sei, Hiroo; Tomita, Toshihiko; Ohda, Yoshio; Fukui, Hirokazu; Watari, Jiro; Miwa, Hiroto

2015-10-15

Esophageal visceral hypersensitivity has been proposed to be the pathogenesis of heartburn sensation in nonerosive reflux disease. Protease-activated receptor-2 (PAR-2) is expressed in human esophageal epithelial cells and is believed to play a role in inflammation and sensation. PAR-2 activation may modulate these responses through adenosine triphosphate (ATP) release, which is involved in transduction of sensation and pain. The transient receptor potential vanilloid receptor 1 (TRPV1) and acid-sensing ion channels (ASICs) are both acid-sensitive nociceptors. However, the interaction among these molecules and the mechanisms of heartburn sensation are still not clear. We therefore examined whether ATP release in human esophageal epithelial cells in response to acid is modulated by TRPV1 and ASICs and whether PAR-2 activation influences the sensitivity of TRPV1 and ASICs. Weak acid (pH 5) stimulated the release of ATP from primary human esophageal epithelial cells (HEECs). This effect was significantly reduced after pretreatment with 5-iodoresiniferatoxin (IRTX), a TRPV1-specific antagonist, or with amiloride, a nonselective ASIC blocker. TRPV1 and ASIC3 small interfering RNA (siRNA) transfection also decreased weak acid-induced ATP release. Pretreatment of HEECs with trypsin, tryptase, or a PAR-2 agonist enhanced weak acid-induced ATP release. Trypsin treatment led to the phosphorylation of TRPV1. Acid-induced ATP release enhancement by trypsin was partially blocked by IRTX, amiloride, or a PAR-2 antagonist. Conversely, acid-induced ATP release was augmented by PAR-2 activation through TRPV1 and ASICs. These findings suggested that the pathophysiology of heartburn sensation or esophageal hypersensitivity may be associated with the activation of PAR-2, TRPV1, and ASICs. Copyright © 2015 the American Physiological Society.

Phosphodiesterase from Daboia russelli russelli venom: purification, partial characterization and inhibition of platelet aggregation.

PubMed

Mitra, Jyotirmoy; Bhattacharyya, Debasish

2014-09-01

Phosphodiesterases (PDEs) belong to a super-family of enzymes that have multiple roles in the metabolism of extracellular nucleotides and regulation of nucleotide-based intercellular signalling. A PDE from Russell's viper (Daboia russelli russelli) venom (DR-PDE) was purified by gel filtration, ion exchange and affinity chromatographies. Homogeneity of the preparation was verified by SDS-PAGE, SE-HPLC and mass spectrometry. It was free from 5'-nucleotidase, alkaline phosphatase and protease activities. Identity of the enzyme was ensured from partial sequence homology with other PDEs. DR-PDE was inactivated by polyvalent anti-venom serum and metal chelators. The enzyme was partially inhibited by the root extracts of four medicinal plants but remained unaffected by inhibitors of intracellular PDEs. DR-PDE hydrolyses ADP and thus, strongly inhibits ADP-induced platelet aggregation in human platelet rich plasma. This study leads to better understanding of a component of Russell's viper venom that affects homoeostatic system of the victim. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mulberry extract supplements ameliorate the inflammation-related hematological parameters in carrageenan-induced arthritic rats.

PubMed

Kim, Ae-Jung; Park, Soojin

2006-01-01

Mulberry fruit (Morus Lhou Koidz.), a rich source of the major anthocyanin, cyanidin 3-glucoside (C3G), has traditionally been used for the treatment of inflammatory conditions including rheumatic arthritis. In this study, we evaluated the efficacy of orally administrated methanolic mulberry fruit extract (ME) in carrageenan-induced arthritic rats, based on previously observed in vitro antioxidant and anti-inflammatory activities. A significant attenuation of hind paw inflammation characterized by fluid accumulation, uric acid production, and rheumatoid factors induced by carrageenan was observed following the intake of both ME (50 mg/kg of body weight) and C3G (10 mg/kg of body weight). Moreover, alterations in hematological parameters such as serum triglyceride, high-density lipoprotein-cholesterol, and atherogenic index following carrageenan administration were partially reversed by the administration of ME. It is concluded that dietary mulberry fruit extracts elicited protection against carrageenan-induced inflammation.

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

Noda, Chiseko; Department of Genomic Science, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017; He, Jinsong

(-)-Epigallocatechin-3-gallate (EGCG), a major constituent of green tea polyphenols, has been shown to suppress cancer cell proliferation and induce apoptosis. In this study we investigated its efficacy and the mechanism underlying its effect using human B lymphoblastoid cell line Ramos, and effect of co-treatment with EGCG and a chemotherapeutic agent on apoptotic cell death. EGCG induced dose- and time-dependent apoptotic cell death accompanied by loss of mitochondrial transmembrane potential, release of cytochrome c into the cytosol, and cleavage of pro-caspase-9 to its active form. EGCG also enhanced production of intracellular reactive oxygen species (ROS). Pretreatment with diphenylene iodonium chloride, anmore » inhibitor of NAD(P)H oxidase and an antioxidant, partially suppressed both EGCG-induced apoptosis and production of ROS, implying that oxidative stress is involved in the apoptotic response. Furthermore, we showed that combined-treatment with EGCG and a chemotherapeutic agent, etoposide, synergistically induced apoptosis in Ramos cells.« less

Tanshinones and diethyl blechnics with anti-inflammatory and anti-cancer activities from Salvia miltiorrhiza Bunge (Danshen)

NASA Astrophysics Data System (ADS)

Gao, Hongwei; Sun, Wen; Zhao, Jianping; Wu, Xiaxia; Lu, Jin-Jian; Chen, Xiuping; Xu, Qiong-Ming; Khan, Ikhlas A.; Yang, Shilin

2016-09-01

Four novel compounds (1-4) as well as fourteen reported compounds (5-18) were isolated and purified from Salvia miltiorrhiza Bunge (Danshen). The structures of novel compounds were determined by 1D and 2D NMR, HRESIMS data, etc. The anti-inflammatory properties of all the compounds on RAW264.7 macrophages and their cytotoxicity on H1299 and Bel-7402 cell lines coupled with a structure-activity relationship (SAR) were investigated. Compound 4 demonstrated the best anti-inflammatory activity and was chosen for further research. Compound 4 greatly suppressed secretion of nitric oxide (NO), tumor necrosis factor (TNF)-α and interleukin-6 (IL-6) in the RAW264.7 macrophages stimulated by LPS. Additionally, the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was decreased and the nuclear translocation of NF-κB was attenuated after treatment with compound 4 in vitro. Compound 4 was able to dramatically inhibit LPS-induced activation of JNK1/2 and ERK1/2 and remarkably disrupted the TLR4 dimerization in LPS-induced RAW264.7 macrophages. Thus, the new compound 4 suppressed LPS-induced inflammation partially is due to the blocking TLR4 dimerization. In addition, the anti-cancer activity investigation indicated that most of isolated compounds exhibited cytotoxicity and the SAR analysis showed that the intact D ring was indispensable and unsaturated D ring played vital role.

Ethylenediaminetetraacetic acid induces antioxidant and anti-inflammatory activities in experimental liver fibrosis.

PubMed

González-Cuevas, J; Navarro-Partida, J; Marquez-Aguirre, A L; Bueno-Topete, M R; Beas-Zarate, C; Armendáriz-Borunda, J

2011-01-01

Experimental liver fibrosis induced by carbon tetrachloride (CCl(4)) is associated with oxidative stress, lipid peroxidation, and inflammation. This work was focused on elucidating the anti-inflammatory and antioxidant effects of ethylenediaminetetraacetic acid (EDTA) in this model of hepatotoxicity. Wistar male rats were treated with CCl(4) and EDTA (60, 120, or 240 mg/kg). Morphometric analyses were carried out in Masson's stained liver sections to determine fibrosis index. Coagulation tests prothrombin time (PT) and partial thromboplastin time (PTT) were also determined. Gene expression for transforming growth factor beta (TGF-beta1), alpha1(I) procollagen gene (alpha1 Col I), tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and superoxide dismutase (SOD) was monitored by real-time PCR. Antioxidant effect of EDTA was measured by its effects on lipid peroxidation; biological activity of ceruloplasmin (Cp), SOD, and catalase (Cat) were analyzed by zymography assays. Animals with CCl(4)-hepatic injury that received EDTA showed a decrement in fibrosis (20%) and lipid peroxidation (22%). The mRNA expression for TNF-alpha (55%), TGF-beta1 (50%), IL-6 (52%), and alpha1 Col I (60%) was also decreased. This group of animals showed increased Cp (62%) and SOD (25%) biological activities. Coagulation blood tests, Cat activity, and gene expression for SOD were not modified by EDTA treatment. This study demonstrates that EDTA treatment induces the activity of antioxidant enzymes, decreases lipid peroxidation, hepatic inflammation, and fibrosis in experimental liver fibrosis induced by CCl(4).

Apoptosis induction is involved in UVA-induced autolysis in sea cucumber Stichopus japonicus.

PubMed

Qi, Hang; Fu, Hui; Dong, Xiufang; Feng, Dingding; Li, Nan; Wen, Chengrong; Nakamura, Yoshimasa; Zhu, Beiwei

2016-05-01

Autolysis easily happens to sea cucumber (Stichopus japonicus, S. japonicus) for external stimulus like UV exposure causing heavy economic losses. Therefore, it is meaningful to reveal the mechanism of S. japonicas autolysis. In the present study, to examine the involvement of apoptosis induction in UVA-induced autolysis of S. japonicas, we investigated the biochemical events including the DNA fragmentation, caspase-3 activation, mitogen-activated protein kinases (MAPKs) phosphorylation and free radical formation. Substantial morphological changes such as intestine vomiting and dermatolysis were observed in S. japonicus during the incubation after 1-h UVA irradiation (10W/m(2)). The degradation of the structural proteins and enhancement of cathepsin L activity were also detected, suggesting the profound impact of proteolysis caused by the UVA irradiation even for 1h. Furthermore, the DNA fragmentation and specific activity of caspase-3 was increased up to 12h after UVA irradiation. The levels of phosphorylated p38 mitogen activated protein kinase (MAPK) and phosphorylated c-Jun.-N-terminal kinase (JNK) were significantly increased by the UVA irradiation for 1h. An electron spin resonance (ESR) analysis revealed that UVA enhanced the free radical formation in S. japonicas, even through we could not identify the attributed species. These results suggest that UVA-induced autolysis in S. japonicas at least partially involves the oxidative stress-sensitive apoptosis induction pathway. These data present a novel insight into the mechanisms of sea cucumber autolysis induced by external stress. Copyright © 2016 Elsevier B.V. All rights reserved.

Docetaxel-induced prostate cancer cell death involves concomitant activation of caspase and lysosomal pathways and is attenuated by LEDGF/p75

PubMed Central

Mediavilla-Varela, Melanie; Pacheco, Fabio J; Almaguel, Frankis; Perez, Jossymar; Sahakian, Eva; Daniels, Tracy R; Leoh, Lai Sum; Padilla, Amelia; Wall, Nathan R; Lilly, Michael B; De Leon, Marino; Casiano, Carlos A

2009-01-01

Background Hormone-refractory prostate cancer (HRPC) is characterized by poor response to chemotherapy and high mortality, particularly among African American men when compared to other racial/ethnic groups. It is generally accepted that docetaxel, the standard of care for chemotherapy of HRPC, primarily exerts tumor cell death by inducing mitotic catastrophe and caspase-dependent apoptosis following inhibition of microtubule depolymerization. However, there is a gap in our knowledge of mechanistic events underlying docetaxel-induced caspase-independent cell death, and the genes that antagonize this process. This knowledge is important for circumventing HRPC chemoresistance and reducing disparities in prostate cancer mortality. Results We investigated mechanistic events associated with docetaxel-induced death in HRPC cell lines using various approaches that distinguish caspase-dependent from caspase-independent cell death. Docetaxel induced both mitotic catastrophe and caspase-dependent apoptosis at various concentrations. However, caspase activity was not essential for docetaxel-induced cytotoxicity since cell death associated with lysosomal membrane permeabilization still occurred in the presence of caspase inhibitors. Partial inhibition of docetaxel-induced cytotoxicity was observed after inhibition of cathepsin B, but not inhibition of cathepsins D and L, suggesting that docetaxel induces caspase-independent, lysosomal cell death. Simultaneous inhibition of caspases and cathepsin B dramatically reduced docetaxel-induced cell death. Ectopic expression of lens epithelium-derived growth factor p75 (LEDGF/p75), a stress survival autoantigen and transcription co-activator, attenuated docetaxel-induced lysosomal destabilization and cell death. Interestingly, LEDGF/p75 overexpression did not protect cells against DTX-induced mitotic catastrophe, and against apoptosis induced by tumor necrosis factor related apoptosis inducing ligand (TRAIL), suggesting selectivity in its pro-survival activity. Conclusion These results underscore the ability of docetaxel to induce concomitantly caspase-dependent and independent death pathways in prostate cancer cells. The results also point to LEDGF/p75 as a potential contributor to cellular resistance to docetaxel-induced lysosomal destabilization and cell death, and an attractive candidate for molecular targeting in HRPC. PMID:19715609

Kinase cascades and ligand-directed signaling at the kappa opioid receptor.

PubMed

Bruchas, Michael R; Chavkin, Charles

2010-06-01

The dynorphin/kappa opioid receptor (KOR) system has been implicated as a critical component of the stress response. Stress-induced activation of dynorphin-KOR is well known to produce analgesia, and more recently, it has been implicated as a mediator of stress-induced responses including anxiety, depression, and reinstatement of drug seeking. Drugs selectively targeting specific KOR signaling pathways may prove potentially useful as therapeutic treatments for mood and addiction disorders. KOR is a member of the seven transmembrane spanning (7TM) G-protein coupled receptor (GPCR) superfamily. KOR activation of pertussis toxin-sensitive G proteins leads to Galphai/o inhibition of adenylyl cyclase production of cAMP and releases Gbetagamma, which modulates the conductances of Ca(+2) and K(+) channels. In addition, KOR agonists activate kinase cascades including G-protein coupled Receptor Kinases (GRK) and members of the mitogen-activated protein kinase (MAPK) family: ERK1/2, p38 and JNK. Recent pharmacological data suggests that GPCRs exist as dynamic, multi-conformational protein complexes that can be directed by specific ligands towards distinct signaling pathways. Ligand-induced conformations of KOR that evoke beta-arrestin-dependent p38 MAPK activation result in aversion; whereas ligand-induced conformations that activate JNK without activating arrestin produce long-lasting inactivation of KOR signaling. In this review, we discuss the current status of KOR signal transduction research and the data that support two novel hypotheses: (1) KOR selective partial agonists that do not efficiently activate p38 MAPK may be useful analgesics without producing the dysphoric or hallucinogenic effects of selective, highly efficacious KOR agonists and (2) KOR antagonists that do not activate JNK may be effective short-acting drugs that may promote stress-resilience.

2′,5′-Dihydroxychalcone-induced glutathione is mediated by oxidative stress and kinase signaling pathways

PubMed Central

Kachadourian, Remy; Pugazhenthi, Subbiah; Velmurugan, Kalpana; Backos, Donald S.; Franklin, Christopher C.; McCord, Joe M.; Day, Brian J.

2011-01-01

Hydroxychalcones are naturally occurring compounds that continue to attract considerable interest due to their anti-inflammatory and anti-angiogenic properties. They have been reported to inhibit the synthesis of the inducible nitric oxide (NO) synthase and to induce the expression of heme oxygenase-1 (HO-1). This study examines the mechanisms by which 2′,5′-dihydroxychalcone (2′,5′-DHC) induces an increase in cellular glutathione (GSH) levels using a cell line stably expressing a luciferase reporter gene driven by antioxidant response elements (MCF-7/AREc32). 2′,5′-DHC-induced increase in cellular GSH levels was partially inhibited by the catalytic antioxidant MnTDE-1,3-IP5+, suggesting that reactive oxygen species (ROS) mediate the antioxidant adaptive response. 2′,5′-DHC treatment induced the phosphorylation of c-Jun N-terminal kinase (JNK) pathway that was also inhibited by MnTDE-1,3-IP5+. These findings suggest a ROS-dependent activation of the AP-1 transcriptional response. However, while 2′,5′-DHC triggered the NF-E2-related factor 2 (Nrf2) transcriptional response, co-treatment with MnTDE-1,3-IP5+ did not decrease 2′,5′-DHC-induced Nrf2/ARE activity, showing that this pathway is not dependent on ROS. Moreover, pharmacological inhibitors of mitogen-activated protein (MAP) kinase pathways showed a role for JNK and p38MAPK in mediating the 2′,5′-DHC-induced Nrf2 response. These findings suggest that the 2′,5′-DHC-induced increase in GSH levels results from a combination of ROS-dependent and ROS-independent pathways. PMID:21712085

Aripiprazole, an Antipsychotic and Partial Dopamine Agonist, Inhibits Cancer Stem Cells and Reverses Chemoresistance.

PubMed

Suzuki, Shuhei; Okada, Masashi; Kuramoto, Kenta; Takeda, Hiroyuki; Sakaki, Hirotsugu; Watarai, Hikaru; Sanomachi, Tomomi; Seino, Shizuka; Yoshioka, Takashi; Kitanaka, Chifumi

2016-10-01

There is a growing interest in repurposing antipsychotic dopamine antagonists for cancer treatment; however, antipsychotics are often associated with an increased risk of fatal events. The anticancer activities of aripiprazole, an antipsychotic drug with partial dopamine agonist activity and an excellent safety profile, remain unknown. The effects of aripiprazole alone or in combination with chemotherapeutic agents on the growth, sphere-forming ability and stem cell/differentiation/chemoresistance marker expression of cancer stem cells, serum-cultured cancer cells from which they were derived, and normal cells were examined. At concentrations non-toxic to normal cells, aripiprazole inhibited the growth of serum-cultured cancer cells and cancer stem cells. Furthermore, aripiprazole induced differentiation and inhibited sphere formation, as well as stem cell marker expression of cancer stem cells while inhibiting their survivin expression and sensitizing them to chemotherapeutic agents. Repurposing aripiprazole as an anticancer stem cell drug may merit further consideration. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Anti-leukaemic activity of the TYK2 selective inhibitor NDI-031301 in T-cell acute lymphoblastic leukaemia.

PubMed

Akahane, Koshi; Li, Zhaodong; Etchin, Julia; Berezovskaya, Alla; Gjini, Evisa; Masse, Craig E; Miao, Wenyan; Rocnik, Jennifer; Kapeller, Rosana; Greenwood, Jeremy R; Tiv, Hong; Sanda, Takaomi; Weinstock, David M; Look, A Thomas

2017-04-01

Activation of tyrosine kinase 2 (TYK2) contributes to the aberrant survival of T-cell acute lymphoblastic leukaemia (T-ALL) cells. Here we demonstrate the anti-leukaemic activity of a novel TYK2 inhibitor, NDI-031301. NDI-031301 is a potent and selective inhibitor of TYK2 that induced robust growth inhibition of human T-ALL cell lines. NDI-031301 treatment of human T-ALL cell lines resulted in induction of apoptosis that was not observed with the JAK inhibitors tofacitinib and baricitinib. Further investigation revealed that NDI-031301 treatment uniquely leads to activation of three mitogen-activated protein kinases (MAPKs), resulting in phosphorylation of ERK, SAPK/JNK and p38 MAPK coincident with PARP cleavage. Activation of p38 MAPK occurred within 1 h of NDI-031301 treatment and was responsible for NDI-031301-induced T-ALL cell death, as pharmacological inhibition of p38 MAPK partially rescued apoptosis induced by TYK2 inhibitor. Finally, daily oral administration of NDI-031301 at 100 mg/kg bid to immunodeficient mice engrafted with KOPT-K1 T-ALL cells was well tolerated, and led to decreased tumour burden and a significant survival benefit. These results support selective inhibition of TYK2 as a promising potential therapeutic strategy for T-ALL. © 2017 John Wiley & Sons Ltd.

Antioxidant, anticholinesterase and antifatigue effects of Trichilia catigua (catuaba).

PubMed

Martins, Nadini Oliveira; de Brito, Isabella Modelli; Araújo, Sandra Syomara O; Negri, Giuseppina; Carlini, Elisaldo de Araújo; Mendes, Fúlvio Rieli

2018-06-05

Trichilia catigua A. Juss. (Meliaceae) is a species known as catuaba and used in folk medicine for the treatment of fatigue, stress, impotence and memory deficit. The main phytochemical compounds identified in the barks of T. catigua are flavalignans, flavan-3-ols and flavonoids which are associated with its antioxidant activity. Pre-clinical studies with T. catigua extracts have identified many pharmacological properties, such as anti-inflammatory, antidepressant, antinociceptive, pro-memory and neuroprotective against ischemia and oxidative stress. This study was designed in order to compare the chemical composition and in vitro antioxidant and anticholinesterase activity of four different polarity extracts and selected the one most active for in vivo studies in rodent models of stress, fatigue and memory. Hexane, chloroform, hydroalcoholic and aqueous extracts from bark of Trichilia catigua were analyzed by RPHPLC-DAD-ESI-MS/MS. Antioxidant activity was assessed by 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay and acetylcholinesterase inhibition by Ellman's modified method. In vivo studies (stress, fatigue and memory) were carried out with adult male mice and rats treated with hydroalcoholic extract in doses of 25-300 mg/kg (p.o.). We confirmed the presence of cinchonain IIa, Ia and Ib, as main constituents in the four extracts, while procyanidins were detected only in hydroalcoholic extract. Antioxidant and anticholinesterase activity were observed for all extracts, with most potent activity found on the hydroalcoholic extract (EC 50  = 43 μg/mL and IC 50  = 142 μg/mL for DPPH scavenger and acetylcholinesterase inhibition, respectively). The treatment of laboratory animals with hydroalcoholic extract did not protect rats from cold immobilization stress and did not prevent the scopolamine-induced amnesia in mice. However, the treatment of mice with the hydroalcoholic extract partially reduced the fatigue induced by treadmill, since the highest dose increased the spontaneous locomotor activity and reduced the deficit on grip strength after the forced exercise (p < 0.05), in some observation times. These data suggest the hydroalcoholic extract as the most suitable for plant extraction and partially support the folk use of T. catigua as antifatigue drug. . Trichilia catigua hydroalcoholic extract exhibits antioxidant and anticholinesterase activity in vitro and reduces the fatigue induced by forced exercise.

Prostaglandins may play a signal-coupling role during phagocytosis in Amoeba proteus.

PubMed

Prusch, R D; Goette, S M; Haberman, P

1989-03-01

Phagocytosis in Amoeba proteus can be induced with prostaglandins (PG). In addition, arachidonic acid (the fatty acid precursor to the PG-2 series) also induces phagocytosis. The induction of phagocytosis with arachidonic acid can be partially inhibited by the cyclooxygenase inhibitor indomethacin. Phagocytosis in the amoeba can also be induced with the chemotactic peptide N-formylmethionyl-leucylphenylalanine (NFMLP). The peptide presumably induces phagocytosis by interacting with receptors on the amoeba surface, which may initiate the release of arachidonic acid from membrane lipids. NFMLP-induced phagocytosis can also be partially inhibited by indomethacin. It is suggested that PG's or biochemically related substances may play a signal-coupling role during phagocytosis in the amoeba.

Cognitive and Neural Effects of Vision-Based Speed-of-Processing Training in Older Adults with Amnestic Mild Cognitive Impairment: A Pilot Study.

PubMed

Lin, Feng; Heffner, Kathi L; Ren, Ping; Tivarus, Madalina E; Brasch, Judith; Chen, Ding-Geng; Mapstone, Mark; Porsteinsson, Anton P; Tadin, Duje

2016-06-01

To examine the cognitive and neural effects of vision-based speed-of-processing (VSOP) training in older adults with amnestic mild cognitive impairment (aMCI) and contrast those effects with an active control (mental leisure activities (MLA)). Randomized single-blind controlled pilot trial. Academic medical center. Individuals with aMCI (N = 21). Six-week computerized VSOP training. Multiple cognitive processing measures, instrumental activities of daily living (IADLs), and two resting state neural networks regulating cognitive processing: central executive network (CEN) and default mode network (DMN). VSOP training led to significantly greater improvements in trained (processing speed and attention: F1,19  = 6.61, partial η(2)  = 0.26, P = .02) and untrained (working memory: F1,19  = 7.33, partial η(2)  = 0.28, P = .01; IADLs: F1,19  = 5.16, partial η(2)  = 0.21, P = .03) cognitive domains than MLA and protective maintenance in DMN (F1, 9  = 14.63, partial η(2)  = 0.62, P = .004). VSOP training, but not MLA, resulted in a significant improvement in CEN connectivity (Z = -2.37, P = .02). Target and transfer effects of VSOP training were identified, and links between VSOP training and two neural networks associated with aMCI were found. These findings highlight the potential of VSOP training to slow cognitive decline in individuals with aMCI. Further delineation of mechanisms underlying VSOP-induced plasticity is necessary to understand in which populations and under what conditions such training may be most effective. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Evaluation of levetiracetam effects on pilocarpine-induced seizures: cholinergic muscarinic system involvement.

PubMed

Oliveira, A A; Nogueira, C R A; Nascimento, V S; Aguiar, L M V; Freitas, R M; Sousa, F C F; Viana, G S B; Fonteles, M M F

2005-09-16

Levetiracetam (LEV) is a new antiepileptic drug effective as adjunctive therapy for partial seizures. It displays a unique pharmacological profile against experimental models of seizures, including pilocarpine-induced seizures in rodents. Aiming to clarify if anticonvulsant activity of LEV occurs due to cholinergic alterations, adult male mice received LEV injections before cholinergic agonists' administration. Pretreatment with LEV (30-200 mg/kg, i.p.) increased the latencies of seizures, but decreased status epilepticus and death on the seizure model induced by pilocarpine, 400 mg/kg, s.c. (P400). LEV (LEV200, 200 mg/kg, i.p.) pretreatment also reduced the intensity of tremors induced by oxotremorine (0.5 mg/kg, i.p). [3H]-N-methylscopolamine-binding assays in mice hippocampus showed that LEV200 pretreatment reverts the downregulation on muscarinic acetylcholine receptors (mAChR), induced by P400 administration, bringing back these density values to control ones (0.9% NaCl, i.p.). However, subtype-specific-binding assays revealed that P400- and LEV-alone treatments result in M1 and M2 subtypes decrease, respectively. The agonist-like behavior of LEV on the inhibitory M2 mAChR subtype, observed in this work, could contribute to explain the reduction on oxotremorine-induced tremors and the delay on pilocarpine-induced seizures, by an increase in the attenuation of neuronal activity mediated by the M1 receptors.

Cardiac microRNA-133 is down-regulated in thyroid hormone-mediated cardiac hypertrophy partially via Type 1 Angiotensin II receptor.

PubMed

Diniz, Gabriela Placoná; Lino, Caroline Antunes; Guedes, Elaine Castilho; Moreira, Luana do Nascimento; Barreto-Chaves, Maria Luiza Morais

2015-09-01

Elevated thyroid hormone (TH) levels induce cardiac hypertrophy partially via type 1 Angiotensin II receptor (AT1R). MicroRNAs (miRNAs) are key regulators of cardiac homeostasis, and miR-133 has been shown to be involved in cardiac hypertrophy. However, the potential role of miR-133 in cardiac growth induced by TH is unknown. Thus, we aimed to investigate the miR-133 expression, as well as its potential role in cardiac hypertrophy in response to TH. Wistar rats were subjected to hyperthyroidism combined or not with the AT1R blocker. T3 serum levels were assessed to confirm the hyperthyroid status. TH induced cardiac hypertrophy, as evidenced by higher cardiac weight/tibia length ratio and α-actin mRNA levels, which was prevented by AT1R blocker. miR-133 expression was decreased in TH-induced cardiac hypertrophy in part through the AT1R. Additionally, the cardiac mRNA levels of miR-133 targets, SERCA2a and calcineurin were increased in hyperthyroidism partially via AT1R, as evaluated by real-time RT-PCR. Interestingly, miR-133 levels were unchanged in T3-induced cardiomyocyte hypertrophy in vitro. However, a gain-of-function study revealed that miR-133 mimic blunted the T3-induced cardiomyocyte hypertrophy in vitro. Together, our data indicate that miR-133 expression is reduced in TH-induced cardiac hypertrophy partially by the AT1R and that miR-133 mimic prevents the cardiomyocyte hypertrophy in response to T3 in vitro. These findings provide new insights regarding the mechanisms involved in the cardiac growth mediated by TH, suggesting that miR-133 plays a key role in TH-induced cardiomyocyte hypertrophy.

Low-dose 6-bromoindirubin-3′-oxime induces partial dedifferentiation of endothelial cells to promote increased neovascularization† (R1)

PubMed Central

KOHLER, ERIN E.; BARUAH, JUGAJYOTI; URAO, NORIFUMI; USHIO-FUKAI, MASUKO; FUKAI, TOHRU; CHATTERJEE, ISHITA; WARY, KISHORE K.

2014-01-01

Endothelial cell (EC) dedifferentiation in relation to neovascularization is a poorly understood process. In this report we addressed the role of Wnt signaling in the mechanisms of neovascularization in adult tissues. Here, we show that a low-dose of 6-bromoindirubin-3′-oxime (BIO), a competitive inhibitor of Glycogen Synthase Kinase (GSK)-3β, induced the stabilization of β-catenin and its subsequent direct interaction with the transcription factor NANOG in the nucleus of ECs. This event induced loss of VE-cadherin from the adherens junctions, increased EC proliferation accompanied by asymmetric cell division (ACD), and formed cellular aggregates in a hanging drop assays indicating the acquisition of a dedifferentiated state. In a chromatin immunoprecipitation assay, nuclear NANOG protein bound to the NANOG- and VEGFR2-promoters in ECs, and the addition of BIO activated the NANOG-promoter-luciferase reporter system in a cell-based assay. Consequently, NANOG-knockdown decreased BIO-induced NOTCH-1 expression, thereby decreasing cell proliferation, ACD and neovascularization. In a Matrigel plug assay, BIO induced increased neovascularization, secondary to the presence of VEGF. Moreover, in a mouse model of hind limb ischemia, BIO augmented neovascularization that was coupled with increased expression of NOTCH-1 in ECs and increased smooth muscle α-actin (SMA)+ cell recruitment around the neovessels. Thus, these results show the ability of a low-dose of BIO to augment neovascularization secondary to VEGF, a process that was accompanied by a partial dedifferentiation of ECs via β-catenin and the NANOG signaling pathway. PMID:24496925

The chemical chaperones tauroursodeoxycholic and 4-phenylbutyric acid accelerate thyroid hormone activation and energy expenditure

PubMed Central

da-Silva, Wagner S.; Ribich, Scott; e Drigo, Rafael Arrojo; Castillo, Melany; Patty, Mary-Elizabeth; Bianco, Antonio C.

2011-01-01

Exposure of cell lines endogenously expressing the thyroid hormone activating enzyme type 2 deiodinase (D2) to the chemical chaperones tauroursodeoxycholic acid (TUDCA) or 4-phenylbutiric acid (4-PBA) increases D2 expression, activity and T3 production. In brown adipocytes, TUDCA or 4-PBA induced T3-dependent genes and oxygen consumption (~2-fold), an effect partially lost in D2 knockout cells. In wild type, but not in D2 knockout mice, administration of TUDCA lowered the respiratory quotient, doubled brown adipose tissue D2 activity and normalized the glucose intolerance associated with high fat feeding. Thus, D2 plays a critical role in the metabolic effects of chemical chaperones. PMID:21237159

Oceanographic applications of laser technology

NASA Technical Reports Server (NTRS)

Hoge, F. E.

1988-01-01

Oceanographic activities with the Airborne Oceanographic Lidar (AOL) for the past several years have primarily been focussed on using active (laser induced pigment fluorescence) and concurrent passive ocean color spectra to improve existing ocean color algorithms for estimating primary production in the world's oceans. The most significant results were the development of a technique for selecting optimal passive wavelengths for recovering phytoplankton photopigment concentration and the application of this technique, termed active-passive correlation spectroscopy (APCS), to various forms of passive ocean color algorithms. Included in this activity is use of airborne laser and passive ocean color for development of advanced satellite ocean color sensors. Promising on-wavelength subsurface scattering layer measurements were recently obtained. A partial summary of these results are shown.

Sulfonation and anticoagulant activity of botryosphaeran from Botryosphaeria rhodina MAMB-05 grown on fructose.

PubMed

Mendes, Simone Ferreira; dos Santos, Osvaldo; Barbosa, Aneli M; Vasconcelos, Ana Flora D; Aranda-Selverio, Gabriel; Monteiro, Nilson K; Dekker, Robert F H; Sá Pereira, Mariana; Tovar, Ana Maria F; Mourão, Paulo A de Souza; da Silva, Maria de Lourdes Corradi

2009-10-01

Botryosphaeran (EPS(FRU)), an exopolysaccharide of the beta-(1-->3,1-->6)-d-glucan type with 31% branching at C-6, is produced by the fungus Botryosphaeria rhodina MAMB-05 when grown on fructose as carbon source. Botryosphaeran was derivatized by sulfonation to induce anticoagulant activity. The effectiveness of the sulfonation reaction by chlorosulfonic acid in pyridine was monitored by the degree of substitution and FT-IR analysis of the sulfonated EPS(FRU) (once sulfonated, EPS(FRUSULF); and re-sulfonated, EPS(FRURESULF)). Activated partial thromboplastin time (APTT) and thrombin time (TT) tests of EPS(FRURESULF) indicated significant in vitro anticoagulant activity that was dose-dependent. EPS(FRU) did not inhibit any of the coagulation tests.

HsfA1a upregulates melatonin biosynthesis to confer cadmium tolerance in tomato plants.

PubMed

Cai, Shu-Yu; Zhang, Yun; Xu, You-Ping; Qi, Zhen-Yu; Li, Meng-Qi; Ahammed, Golam Jalal; Xia, Xiao-Jian; Shi, Kai; Zhou, Yan-Hong; Reiter, Russel J; Yu, Jing-Quan; Zhou, Jie

2017-03-01

Melatonin regulates broad aspects of plant responses to various biotic and abiotic stresses, but the upstream regulation of melatonin biosynthesis by these stresses remains largely unknown. Herein, we demonstrate that transcription factor heat-shock factor A1a (HsfA1a) conferred cadmium (Cd) tolerance to tomato plants, in part through its positive role in inducing melatonin biosynthesis under Cd stress. Analysis of leaf phenotype, chlorophyll content, and photosynthetic efficiency revealed that silencing of the HsfA1a gene decreased Cd tolerance, whereas its overexpression enhanced plant tolerance to Cd. HsfA1a-silenced plants exhibited reduced melatonin levels, and HsfA1a overexpression stimulated melatonin accumulation and the expression of the melatonin biosynthetic gene caffeic acid O-methyltransferase 1 (COMT1) under Cd stress. Both an in vitro electrophoretic mobility shift assay and in vivo chromatin immunoprecipitation coupled with qPCR analysis revealed that HsfA1a binds to the COMT1 gene promoter. Meanwhile, Cd stress induced the expression of heat-shock proteins (HSPs), which was compromised in HsfA1a-silenced plants and more robustly induced in HsfA1a-overexpressing plants under Cd stress. COMT1 silencing reduced HsfA1a-induced Cd tolerance and melatonin accumulation in HsfA1a-overexpressing plants. Additionally, the HsfA1a-induced expression of HSPs was partially compromised in COMT1-silenced wild-type or HsfA1a-overexpressing plants under Cd stress. These results demonstrate that HsfA1a confers Cd tolerance by activating transcription of the COMT1 gene and inducing accumulation of melatonin that partially upregulates expression of HSPs. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Extracellular high-mobility group box 1 mediates pressure overload-induced cardiac hypertrophy and heart failure.

PubMed

Zhang, Lei; Liu, Ming; Jiang, Hong; Yu, Ying; Yu, Peng; Tong, Rui; Wu, Jian; Zhang, Shuning; Yao, Kang; Zou, Yunzeng; Ge, Junbo

2016-03-01

Inflammation plays a key role in pressure overload-induced cardiac hypertrophy and heart failure, but the mechanisms have not been fully elucidated. High-mobility group box 1 (HMGB1), which is increased in myocardium under pressure overload, may be involved in pressure overload-induced cardiac injury. The objectives of this study are to determine the role of HMGB1 in cardiac hypertrophy and cardiac dysfunction under pressure overload. Pressure overload was imposed on the heart of male wild-type mice by transverse aortic constriction (TAC), while recombinant HMGB1, HMGB1 box A (a competitive antagonist of HMGB1) or PBS was injected into the LV wall. Moreover, cardiac myocytes were cultured and given sustained mechanical stress. Transthoracic echocardiography was performed after the operation and sections for histological analyses were generated from paraffin-embedded hearts. Relevant proteins and genes were detected. Cardiac HMGB1 expression was increased after TAC, which was accompanied by its translocation from nucleus to both cytoplasm and intercellular space. Exogenous HMGB1 aggravated TAC-induced cardiac hypertrophy and cardiac dysfunction, as demonstrated by echocardiographic analyses, histological analyses and foetal cardiac genes detection. Nevertheless, the aforementioned pathological change induced by TAC could partially be reversed by HMGB1 inhibition. Consistent with the in vivo observations, mechanical stress evoked the release and synthesis of HMGB1 in cultured cardiac myocytes. This study indicates that the activated and up-regulated HMGB1 in myocardium, which might partially be derived from cardiac myocytes under pressure overload, may be of crucial importance in pressure overload-induced cardiac hypertrophy and cardiac dysfunction. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Antiplatelet, anticoagulant, and profibrinolytic activities of withaferin A.

PubMed

Ku, Sae-Kwang; Bae, Jong-Sup

2014-03-01

Withaferin A (WFA), an active compound from Withania somnifera, is widely researched for its anti-inflammatory, cardioactive and central nervous system effects. However, antiplatelet, anticoagulant, and profibrinolytic properties of WFA have not been studied. In this study, the anticoagulant activities of WFA were measured by monitoring activated partial thromboplastin-time (aPTT), prothrombin time (PT), fibrin polymerization, platelet aggregation, thrombus formation, and the activities of cell-based thrombin and activated factor X (FXa). The effects of WFA on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were also tested in tumor necrosis factor-α (TNF-α) activated human umbilical vein endothelial cells (HUVECs). Our data showed that WFA inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation, FeCl3-induced thrombus formation, prolonged aPTT and PT significantly and inhibited the activities and production of thrombin and FXa. WFA prolonged in vivo and ex vivo bleeding time and inhibited TNF-α induced PAI-1 production. Furthermore, PAI-1/t-PA ratio was significantly decreased by WFA. Collectively, these results indicate that WFA possesses antithrombotic activities and suggest that the current study could provide bases for the development of new anticoagulant agents. Copyright © 2014 Elsevier Inc. All rights reserved.

Ovariectomy induces a shift in fuel availability and metabolism in the hippocampus of the female transgenic model of familial Alzheimer's.

PubMed

Ding, Fan; Yao, Jia; Zhao, Liqin; Mao, Zisu; Chen, Shuhua; Brinton, Roberta Diaz

2013-01-01

Previously, we demonstrated that reproductive senescence in female triple transgenic Alzheimer's (3×TgAD) mice was paralleled by a shift towards a ketogenic profile with a concomitant decline in mitochondrial activity in brain, suggesting a potential association between ovarian hormone loss and alteration in the bioenergetic profile of the brain. In the present study, we investigated the impact of ovariectomy and 17β-estradiol replacement on brain energy substrate availability and metabolism in a mouse model of familial Alzheimer's (3×TgAD). Results of these analyses indicated that ovarian hormones deprivation by ovariectomy (OVX) induced a significant decrease in brain glucose uptake indicated by decline in 2-[(18)F]fluoro-2-deoxy-D-glucose uptake measured by microPET-imaging. Mechanistically, OVX induced a significant decline in blood-brain-barrier specific glucose transporter expression, hexokinase expression and activity. The decline in glucose availability was accompanied by a significant rise in glial LDH5 expression and LDH5/LDH1 ratio indicative of lactate generation and utilization. In parallel, a significant rise in ketone body concentration in serum occurred which was coupled to an increase in neuronal MCT2 expression and 3-oxoacid-CoA transferase (SCOT) required for conversion of ketone bodies to acetyl-CoA. In addition, OVX-induced decline in glucose metabolism was paralleled by a significant increase in Aβ oligomer levels. 17β-estradiol preserved brain glucose-driven metabolic capacity and partially prevented the OVX-induced shift in bioenergetic substrate as evidenced by glucose uptake, glucose transporter expression and gene expression associated with aerobic glycolysis. 17β-estradiol also partially prevented the OVX-induced increase in Aβ oligomer levels. Collectively, these data indicate that ovarian hormone loss in a preclinical model of Alzheimer's was paralleled by a shift towards the metabolic pathway required for metabolism of alternative fuels in brain with a concomitant decline in brain glucose transport and metabolism. These findings also indicate that estrogen plays a critical role in sustaining brain bioenergetic capacity through preservation of glucose metabolism.

Telmisartan, an AT1 receptor blocker and a PPAR gamma activator, alleviates liver fibrosis induced experimentally by Schistosoma mansoni infection.

PubMed

Attia, Yasmeen M; Elalkamy, Essam F; Hammam, Olfat A; Mahmoud, Soheir S; El-Khatib, Aiman S

2013-07-05

Hepatic schistosomiasis is considered to be one of the most prevalent forms of chronic liver disease in the world due to its complication of liver fibrosis. The demonstration of the pro-fibrogenic role of angiotensin (Ang) II in chronic liver disease brought up the idea that anti-Ang II agents may be effective in improving hepatic fibrosis by either blocking Ang II type 1 (AT1) receptors or inhibiting the angiotensin converting enzyme. Peroxisome proliferator-activated receptors gamma (PPARγ) activation has been also shown to inhibit hepatic stellate cell activation and progression of fibrosis. The present study has aimed at testing the anti-fibrogenic effects of telmisartan; an AT1 receptor blocker and a PPARγ partial agonist, alone or combined with praziquantel (PZQ) on Schistosoma mansoni-induced liver fibrosis in mice. To achieve the aim of the study, two sets of experiments were performed in which telmisartan was initiated at the 5th (set 1) and the 10th (set 2) weeks post infection to assess drug efficacy in both acute and chronic stages of liver fibrosis, respectively. Schistosoma mansoni-infected mice were randomly divided into the following four groups: infected-control (I), telmisartan-treated (II), PZQ-treated (III), and telmisartan+PZQ-treated (IV). In addition, a normal non-infected group was used for comparison. Parasitological (hepatomesenteric worm load and oogram pattern), histopathological, morphometric, immunohistochemical (hepatic expressions of matrix metalloproteinase-2; MMP-2 and tissue inhibitor of metalloproteinase-2; TIMP-2), and biochemical (serum transforming growth factor beta 1; TGF-β1 and liver function tests) studies were performed. Telmisartan failed to improve the parasitological parameters, while it significantly (P<0.05) decreased the mean granuloma diameter, area of fibrosis, and serum TGF-β1. Additionally, telmisartan increased MMP-2 and decreased TIMP-2 hepatic expression. Combined treatment failed to show any additive properties, yet it did not affect the anti-schistosomal activity of PZQ. These results suggest potential anti-fibrotic effects of telmisartan, an AT1 receptor blocker and a PPARγ partial agonist, in acute and chronic stages of Schistosoma mansoni-induced liver fibrosis in mice.

Single ingestion of soy β-conglycinin induces increased postprandial circulating FGF21 levels exerting beneficial health effects.

PubMed

Hashidume, Tsutomu; Kato, Asuka; Tanaka, Tomohiro; Miyoshi, Shoko; Itoh, Nobuyuki; Nakata, Rieko; Inoue, Hiroyasu; Oikawa, Akira; Nakai, Yuji; Shimizu, Makoto; Inoue, Jun; Sato, Ryuichiro

2016-06-17

Soy protein β-conglycinin has serum lipid-lowering and anti-obesity effects. We showed that single ingestion of β-conglycinin after fasting alters gene expression in mouse liver. A sharp increase in fibroblast growth factor 21 (FGF21) gene expression, which is depressed by normal feeding, resulted in increased postprandial circulating FGF21 levels along with a significant decrease in adipose tissue weights. Most increases in gene expressions, including FGF21, were targets for the activating transcription factor 4 (ATF4), but not for peroxisome proliferator-activated receptor α. Overexpression of a dominant-negative form of ATF4 significantly reduced β-conglycinin-induced increases in hepatic FGF21 gene expression. In FGF21-deficient mice, β-conglycinin effects were partially abolished. Methionine supplementation to the diet or primary hepatocyte culture medium demonstrated its importance for activating liver or hepatocyte ATF4-FGF21 signaling. Thus, dietary β-conglycinin intake can impact hepatic and systemic metabolism by increasing the postprandial circulating FGF21 levels.

Genome-wide Functional Analysis of CREB/Long-Term Memory-Dependent Transcription Reveals Distinct Basal and Memory Gene Expression Programs

PubMed Central

Lakhina, Vanisha; Arey, Rachel N.; Kaletsky, Rachel; Kauffman, Amanda; Stein, Geneva; Keyes, William; Xu, Daniel; Murphy, Coleen T.

2014-01-01

SUMMARY Induced CREB activity is a hallmark of long-term memory, but the full repertoire of CREB transcriptional targets required specifically for memory is not known in any system. To obtain a more complete picture of the mechanisms involved in memory, we combined memory training with genome-wide transcriptional analysis of C. elegans CREB mutants. This approach identified 757 significant CREB/memory-induced targets and confirmed the involvement of known memory genes from other organisms, but also suggested new mechanisms and novel components that may be conserved through mammals. CREB mediates distinct basal and memory transcriptional programs at least partially through spatial restriction of CREB activity: basal targets are regulated primarily in nonneuronal tissues, while memory targets are enriched for neuronal expression, emanating from CREB activity in AIM neurons. This suite of novel memory-associated genes will provide a platform for the discovery of orthologous mammalian long-term memory components. PMID:25611510

Hypothalamic PKA regulates leptin sensitivity and adiposity

PubMed Central

Yang, Linghai; McKnight, G. Stanley

2015-01-01

Mice lacking the RIIβ regulatory subunit of cyclic AMP-dependent protein kinase A (PKA) display reduced adiposity and resistance to diet-induced obesity. Here we show that RIIβ knockout (KO) mice have enhanced sensitivity to leptin's effects on both feeding and energy metabolism. After administration of a low dose of leptin, the duration of hypothalamic JAK/STAT3 signalling is increased, resulting in enhanced POMC mRNA induction. Consistent with the extended JAK/STAT3 activation, we find that the negative feedback regulator of leptin receptor signalling, Socs3, is inhibited in the hypothalamus of RIIβ KO mice. During fasting, RIIβ–PKA is activated and this correlates with an increase in CREB phosphorylation. The increase in CREB phosphorylation is absent in the fasted RIIβ KO hypothalamus. Selective inhibition of PKA activity in AgRP neurons partially recapitulates the leanness and resistance to diet-induced obesity of RIIβ KO mice. Our findings suggest that RIIβ–PKA modulates the duration of leptin receptor signalling and therefore the magnitude of the catabolic response to leptin. PMID:26381935

Chronic administration of sulbutiamine improves long term memory formation in mice: possible cholinergic mediation.

PubMed

Micheau, J; Durkin, T P; Destrade, C; Rolland, Y; Jaffard, R

1985-08-01

Thiamine deficiency in both man and animals is known to produce memory dysfunction and cognitive disorders which have been related to an impairment of cholinergic activity. The present experiment was aimed at testing whether, inversely, chronic administration of large doses of sulbutiamine would have a facilitative effect on memory and would induce changes in central cholinergic activity. Accordingly mice received 300 mg/kg of sulbutiamine daily for 10 days. They were then submitted to an appetitive operant level press conditioning test. When compared to control subjects, sulbutiamine treated mice learned the task at the same rate in a single session but showed greatly improved performance when tested 24 hr after partial acquisition of the same task. Parallel neurochemical investigations showed that the treatment induced a slight (+ 10%) but significant increase in hippocampal sodium-dependent high affinity choline uptake. The present findings and previous results suggest that sulbutiamine improves memory formation and that this behavioral effect could be mediated by an increase in hippocampal cholinergic activity.

Isolation and characterization of an anti-leishmanial disintegrin from Cerastes cerastes venom.

PubMed

Allane, Dihia; Oussedik-Oumehdi, Habiba; Harrat, Zoubir; Seve, Michel; Laraba-Djebari, Fatima

2018-02-01

Investigating new antimicrobial and antiparasitic components from Viperidae venoms represents an alternative therapeutic strategy. In this study, we report the characterization of a disintegrin isolated from Cerastes cerastes venom, exhibiting antiparasitic activity on Leishmania infantum promastigotes. Indeed, isolated disintegrin, referred to Disintegrin_Cc, induced 84.75% of parasiticidal activity and deep morphological alterations on the parasites. SDS-PAGE analysis indicated that this disintegrin was homogenous. This dimeric disintegrin of 14,193.97 Da contains an RGD domain and four intramolecular disulfide bridges. It presents a high percentage of identity with other related snake disintegrins. Predicted 3D structure indicated that this peptide shares partial homology with well-known active antimicrobial peptides. Disintegrin_Cc inhibited 80% of arachidonic acid-induced platelet aggregation. The obtained results suggest that the isolated molecule plays a dual role as a disintegrin and as an anti-leishmanial compound. This component could be useful as a drug in the treatment of leishmaniasis. © 2017 Wiley Periodicals, Inc.

Saccharomyces cerevisiae Produces a Yeast Substance that Exhibits Estrogenic Activity in Mammalian Systems

NASA Astrophysics Data System (ADS)

Feldman, David; Stathis, Peter A.; Hirst, Margaret A.; Price Stover, E.; Do, Yung S.; Kurz, Walter

1984-06-01

Partially purified lipid extracts of Saccharomyces cerevisiae contain a substance that displaces tritiated estradiol from rat uterine cytosol estrogen receptors. The yeast product induces estrogenic bioresponses in mammalian systems as measured by induction of progesterone receptors in cultured MCF-7 human breast cancer cells and by a uterotrophic response and progesterone receptor induction after administration to ovariectomized mice. The findings raise the possibility that bakers' yeast may be a source of environmental estrogens.

Hydrogen peroxide scavenger, catalase, alleviates ion transport dysfunction in murine colitis.

PubMed

Barrett, Kim E; McCole, Declan F

2016-11-01

Reactive oxygen species (ROS) such as hydrogen peroxide (H 2 O 2 ) contribute to epithelial damage and ion transport dysfunction (key events in inflammatory diarrhoea) in inflammatory bowel disease (IBD). The aim of this study was to identify if H 2 O 2 mediates suppression of colonic ion transport function in the murine dextran sulfate sodium (DSS) colitis model by using the H 2 O 2 degrading enzyme, catalase. Colitis was induced by administering DSS (4%) in drinking water for 5 days followed by 3 days on normal H 2 O. Mice were administered either pegylated catalase or saline at day -1, 0 and +1 of DSS treatment. Ion transport responses to the Ca 2+ -dependent agonist, carbachol (CCh), or the cAMP-dependent agonist, forskolin, were measured across distal colonic mucosa mounted in Ussing chambers. Parameters of DSS-induced inflammation (loss in body weight, decreased colon length, altered stool consistency), were only partially alleviated by catalase while histology was only minimally improved. However, catalase significantly reversed the DSS-induced reduction in baseline ion transport as well as colonic I sc responses to CCh. However, ion transport responses to forskolin were not significantly restored. Catalase also reduced activation of ERK MAP kinase in the setting of colitis, and increased expression of the Na + -K + -2Cl - cotransporter, NKCC1, consistent with restoration of ion transport function. Ex vivo treatment of inflamed colonic mucosae with catalase also partially restored ion transport function. Therefore, catalase partially prevents, and rescues, the loss of ion transport properties in DSS colitis even in the setting of unresolved tissue inflammation. These findings indicate a prominent role for ROS in ion transport dysfunction in colitis and may suggest novel strategies for the treatment of inflammatory diarrhoea. © 2016 John Wiley & Sons Australia, Ltd.

The Hydrogen Peroxide Scavenger, Catalase, Alleviates Ion Transport Dysfunction in Murine Colitis

PubMed Central

Barrett, Kim E.; McCole, Declan F.

2016-01-01

Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) contribute to epithelial damage and ion transport dysfunction (key events in inflammatory diarrhea) in inflammatory bowel disease (IBD). The aim of this study was to identify if H2O2 mediates suppression of colonic ion transport function in the murine dextran sulfate sodium (DSS) colitis model by using the H2O2 degrading enzyme, catalase. Colitis was induced by administering DSS (4%) in drinking water for 5 days followed by 3 days on normal H2O. Mice were administered either pegylated-catalase or saline at day −1, 0 and +1 of DSS treatment. Ion transport responses to the Ca2+-dependent agonist, carbachol (CCh), or the cAMP-dependent agonist, forskolin, were measured across distal colonic mucosa mounted in Ussing chambers. Parameters of DSS-induced inflammation (loss in body weight, decreased colon length, altered stool consistency), were only partially alleviated by catalase while histology was only minimally improved. However, catalase significantly reversed the DSS-induced reduction in baseline ion transport as well as colonic Isc responses to CCh. However, ion transport responses to forskolin were not significantly restored. Catalase also reduced activation of ERK MAP kinase in the setting of colitis, and increased expression of the Na+-K+-2Cl− cotransporter, NKCC1, consistent with restoration of ion transport function. Ex vivo treatment of inflamed colonic mucosae with catalase also partially restored ion transport function. Therefore, catalase partially prevents, and rescues, the loss of ion transport properties in DSS colitis even in the setting of unresolved tissue inflammation. These findings indicate a prominent role for ROS in ion transport dysfunction in colitis and may suggest novel strategies for the treatment of inflammatory diarrhea. PMID:27543846

Protective effect of N-acetyl-L-cysteine against disulfiram-induced oxidative stress and apoptosis in V79 cells

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

Grosicka-Maciag, Emilia; Kurpios-Piec, Dagmara; Grzela, Tomasz

2010-11-01

This work investigated the effect of N-acetyl-L-cysteine (NAC) on disulfiram (DSF) induced oxidative stress in Chinese hamster fibroblast cells (V79). An increase in oxidative stress induced by DSF was observed up to a 200 {mu}M concentration. It was evidenced by a statistically significant increase of both GSH{sub t} and GSSG levels, as well as elevated protein carbonyl (PC) content. There was no increase in lipid peroxidation (measured as TBARS). DSF increased CAT activity, but did not change SOD1 and SOD2 activities. Analysis of GSH related enzymes showed that DSF significantly increased GR activity, did not change Se-dependent GPx, but statisticallymore » significantly decreased non-Se-dependent GPx activity. DSF showed also pro-apoptotic activity. NAC alone did not produce any significant changes, besides an increase of GSH{sub t} level, in any of the variables measured. However, pre-treatment of cells with NAC ameliorated DSF-induced changes. NAC pre-treatment restored the viability of DSF-treated cells evaluated by Trypan blue exclusion assay and MTT test, GSSG level, and protein carbonyl content to the control values as well as it reduced pro-apoptotic activity of DSF. The increase of CAT and GR activity was not reversed. Activity of both GPx was significantly increased compared to their values after DSF treatment. In conclusion, oxidative properties are at least partially attributable to the cellular effects of disulfiram and mechanisms induced by NAC pre-treatment may lower or even abolish the observed effects. These observations illustrate the importance of the initial cellular redox state in terms of cell response to disulfiram exposure. -- Research Highlights: {yields}This report explores biological properties of disulfiram under a condition of modulated intra-cellular GSH level. It shows a protective role of N-acetyl-L-cysteine in V79 cells exposed to disulfiram (in GSH metabolism as well as in changes of antioxidant enzyme activity).« less

Polyubiquitin conjugation to NEMO by triparite motif protein 23 (TRIM23) is critical in antiviral defense

PubMed Central

Arimoto, Kei-ichiro; Funami, Kenji; Saeki, Yasushi; Tanaka, Keiji; Okawa, Katsuya; Takeuchi, Osamu; Akira, Shizuo; Murakami, Yoshiki; Shimotohno, Kunitada

2010-01-01

The rapid induction of type I IFN is a central event of the innate defense against viral infections and is tightly regulated by a number of cellular molecules. Viral components induce strong type I IFN responses through the activation of toll-like receptors (TLRs) and intracellular cytoplasmic receptors such as an RNA helicase RIG-I and/or MDA5. According to recent studies, the NF-κB essential modulator (NEMO, also called IKKγ) is crucial for this virus-induced antiviral response. However, the precise roles of signal activation by NEMO adaptor have not been elucidated. Here, we show that virus-induced IRF3 and NF-κB activation depends on the K(lys)-27-linked polyubiquitination to NEMO by the novel ubiquitin E3 ligase triparite motif protein 23 (TRIM23). Virus-induced IRF3 and NF-κB activation, as well as K27-linked NEMO polyubiquitination, were abrogated in TRIM23 knockdown cells, whereas TRIM23 knockdown had no effect on TNFα-mediated NF-κB activation. Furthermore, in NEMO-deficient mouse embryo fibroblast cells, IFN-stimulated response element-driven reporter activity was restored by ectopic expression of WT NEMO, as expected, but only partial recovery by NEMO K165/309/325/326/344R multipoints mutant on which TRIM23-mediated ubiquitin conjugation was substantially reduced. Thus, we conclude that TRIM23-mediated ubiquitin conjugation to NEMO is essential for TLR3- and RIG-I/MDA5-mediated antiviral innate and inflammatory responses. PMID:20724660

Suppression of osteogenic activity by regulation of WNT and BMP signaling during titanium particle induced osteolysis.

PubMed

Nam, Ju-Suk; Sharma, Ashish Ranjan; Jagga, Supriya; Lee, Dong-Hyun; Sharma, Garima; Nguyen, Lich Thi; Lee, Yeon Hee; Chang, Jun-Dong; Chakraborty, Chiranjib; Lee, Sang-Soo

2017-03-01

Periprosthetic osteolysis remains the leading obstacle for total joint replacements. Primarily, it was thought that aseptic loosening is mainly caused by macrophage mediated inflammatory process arising from production of wear debris. The role of osteoclasts and its sequential bone resorption ability has been extensively studied, but little is known about impaired osteogenesis during osteolysis. In the current study, we have tried to delineate the regulatory mechanism of osteogenic signals by Ti particles in osteoprogenitor cells as well its participatory role in wear debris induced osteolysis. Implantation of Ti particles on mice calvaria induced pro-inflammatory response, elevated expression of COX2 and reduced the expression of Osterix. Treatment of Ti particles to MC3T3 E-1 cells displayed decreased osteogenic activity including ALP activity, mineralization and mRNA levels several osteogenic genes. Moreover, the basal activity of WNT and BMP signaling pathways was suppressed in MC3T3 E-1 cells treated with Ti particles. As an early response to Ti particles, MC3T3 E-1 cells showed activation of ERK and JNK. Co-inhibition of ERK and JNK with their specific inhibitors resulted in partial recovery of WNT and BMP signaling activity as well as ALP activity and collagen synthesis. Finally, LiCl mediated activation of WNT signaling pathway demonstrated rescue of Ti particle facilitated suppression of Osterix expression in mice calvaria. Our results provide evidences that WNT signaling pathway is regulated by ERK, JNK, and BMP signaling pathway during wear debris induced inflammatory osteolysis and may be considered as suitable therapeutic targets for the treatment. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 912-926, 2017. © 2017 Wiley Periodicals, Inc.

Methylmercury-induced alterations in astrocyte functions are attenuated by ebselen.

PubMed

Yin, Zhaobao; Lee, Eunsook; Ni, Mingwei; Jiang, Haiyan; Milatovic, Dejan; Rongzhu, Lu; Farina, Marcelo; Rocha, Joao B T; Aschner, Michael

2011-06-01

Methylmercury (MeHg) preferentially accumulates in glia of the central nervous system (CNS), but its toxic mechanisms have yet to be fully recognized. In the present study, we tested the hypothesis that MeHg induces neurotoxicity via oxidative stress mechanisms, and that these effects are attenuated by the antioxidant, ebselen. Rat neonatal primary cortical astrocytes were pretreated with or without 10 μM ebselen for 2h followed by MeHg (0, 1, 5, and 10 μM) treatments. MeHg-induced changes in astrocytic [(3)H]-glutamine uptake were assessed along with changes in mitochondrial membrane potential (ΔΨ(m)), using the potentiometric dye tetramethylrhodamine ethyl ester (TMRE). Western blot analysis was used to detect MeHg-induced ERK (extracellular-signal related kinase) phosphorylation and caspase-3 activation. MeHg treatment significantly decreased (p<0.05) astrocytic [(3)H]-glutamine uptake at all time points and concentrations. Ebselen fully reversed MeHg's (1 μM) effect on [(3)H]-glutamine uptake at 1 min. At higher MeHg concentrations, ebselen partially reversed the MeHg-induced astrocytic inhibition of [(3)H]-glutamine uptake [at 1 min (5 and 10 μM) (p<0.05); 5 min (1, 5 and 10 μM) (p<0.05)]. MeHg treatment (1h) significantly (p<0.05) dissipated the ΔΨ(m) in astrocytes as evidenced by a decrease in mitochondrial TMRE fluorescence. Ebselen fully reversed the effect of 1 μM MeHg treatment for 1h on astrocytic ΔΨ(m) and partially reversed the effect of 5 and 10 μM MeHg treatments for 1h on ΔΨ(m). In addition, ebselen inhibited MeHg-induced phosphorylation of ERK (p<0.05) and blocked MeHg-induced activation of caspase-3 (p<0.05-0.01). These results are consistent with the hypothesis that MeHg exerts its toxic effects via oxidative stress and that the phosphorylation of ERK and the dissipation of the astrocytic mitochondrial membrane potential are involved in MeHg toxicity. In addition, the protective effects elicited by ebselen reinforce the idea that organic selenocompounds represent promising strategies to counteract MeHg-induced neurotoxicity. Copyright © 2011 Elsevier Inc. All rights reserved.

In vitro pharmacology of aripiprazole, its metabolite and experimental dopamine partial agonists at human dopamine D2 and D3 receptors.

PubMed

Tadori, Yoshihiro; Forbes, Robert A; McQuade, Robert D; Kikuchi, Tetsuro

2011-10-15

Aripiprazole is the first dopamine D(2)/D(3) receptor partial agonist successfully developed and ultimately approved for treatment of a broad spectrum of psychiatric and neurological disorders. Aripiprazole's dopamine D(2) and serotonin 5-HT(1A) receptor partial agonist activities have been postulated to confer clinical efficacy without marked sedation, and a relatively favorable overall side-effect profile. Using aripiprazole's unique profile as a benchmark for new dopamine partial agonist development may facilitate discovery of new antipsychotics. We conducted an in vitro comparative analysis between aripiprazole, and its human metabolite OPC-14857 (7-(4-[4-(2,3-dichlorophenyl)-1-piperazinyl)butoxy)-2(1H)-quinolinone)); RGH-188 (trans-1-[4-[2-[4-(2,3-dichlorophenyl)piperazine-1-yl]ethyl]cyclohexyl]-3,3-dimethylurea), and its metabolite didesmethyl-RGH-188 (DDM-RGH-188); as well as bifeprunox, sarizotan, N-desmethylclozapine (NDMC; clozapine metabolite), and SDZ 208-912 (N-[(8α)-2-chloro-6-methylergolin-8-yl]-2,2-dimethylpropanamide). In vitro pharmacological assessment included inhibition of forskolin-stimulated cAMP accumulation and the reversal of dopamine-induced inhibition in clonal Chinese hamster ovary cell lines expressing D(2S), D(2L), D(3) Ser-9 and D(3) Gly-9 for human dopamine receptors. All test compounds behaved as dopamine D(2)/D(3) receptor partial agonists. Aripiprazole's intrinsic activity at dopamine D(2S) and D(2L) receptors was similar to that of OPC-14857 and RGH-188; lower than that of dopamine and bifeprunox; and higher than that of DDM-RGH-188, SDZ 208-912, sarizotan, and NDMC. Aripiprazole's intrinsic activity at dopamine D(3) Ser-9 and D(3) Gly-9 receptors was similar to that of OPC-14857 and sarizotan; lower than that of dopamine, bifeprunox, RGH-188 and DDM-RGH-188; and higher than that of SDZ 208-912 and NDMC. A consolidated assessment of these findings may help defining the most appropriate magnitude of intrinsic activity at dopamine D(2)/D(3) receptors for clinical efficacy and safety. Copyright © 2011 Elsevier B.V. All rights reserved.

Cerebral blood flow during paroxysmal EEG activation induced by sleep in patients with complex partial seizures

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

Gozukirmizi, E.; Meyer, J.S.; Okabe, T.

1982-01-01

Cerebral blood flow (CBF) measurements were combined with sleep polysomnography in nine patients with complex partial seizures. Two methods were used: the 133Xe method for measuring regional (rCBF) and the stable xenon CT method for local (LCBF). Compared to nonepileptic subjects, who show diffuse CBF decreases during stages I-II, non-REM sleep onset, patients with complex partial seizures show statistically significant increases in CBF which are maximal in regions where the EEG focus is localized and are predominantly seen in one temporal region but are also propagated to other cerebral areas. Both CBF methods gave comparable results, but greater statistical significancemore » was achieved by stable xenon CT methodology. CBF increases are more diffuse than predicted by EEG paroxysmal activity recorded from scalp electrodes. An advantage of the 133Xe inhalation method was achievement of reliable data despite movement of the head. This was attributed to the use of a helmet which maintained the probes approximated to the scalp. Disadvantages were poor resolution (7 cm3) and two-dimensional information. The advantage of stable xenon CT method is excellent resolution (80 mm3) in three dimensions, but a disadvantage is that movement of the head in patients with seizure disorders may limit satisfactory measurements.« less

Activation of AIFM2 enhances apoptosis of human lung cancer cells undergoing toxicological stress.

PubMed

Lu, Jun; Chen, Jian; Xu, Nianjun; Wu, Jun; Kang, Yani; Shen, Tingting; Kong, Hualei; Ma, Chao; Cheng, Ming; Shao, Zhifeng; Xu, Ling; Zhao, Xiaodong

2016-09-06

Application of cisplatin (DDP) for treating lung cancer is restricted due to its toxicity and lung cancer's drug resistance. In this study, we examined the effect of Jinfukang (JFK), an effective herbal medicine against lung cancer, on DDP-induced cytotoxicity in lung cancer cells. Morphologically, we observed that JFK increases DDP-induced pro-apoptosis in A549 cells in a synergistic manner. Transcriptome profiling analysis indicated that the combination of JFK and DDP regulates genes involved in apoptosis-related signaling pathways. Moreover, we found that the combination of JFK and DDP produces synergistic pro-apoptosis effect in other lung cancer cell lines, such as NCI-H1975, NCI-H1650, and NCI-H2228. Particularly, we demonstrated that AIFM2 is activated by the combined treatment of JFK and DDP and partially mediates the synergistic pro-apoptosis effect. Collectively, this study not only offered the first evidence that JFK promotes DDP-induced cytotoxicity, and activation of AIFM2 enhances apoptosis of human lung cancer cells undergoing toxicological stress, but also provided a novel insight for improving cytotoxicity by combining JFK with DDP to treat lung cancer cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Learning and memory promoting effects of crude garlic extract.

PubMed

Mukherjee, Dhrubajyoti; Banerjee, Sugato

2013-12-01

Chronic administration of aged garlic extract has been shown to prevent memory impairment in mice. Acute and chronic (21 days) effects of marketed formulation of crude garlic extract (Lasuna) were evaluated on learning and memory in mice using step down latency (SDL) by passive avoidance response and transfer latency (TL) using elevated plus maze. Scopolamine (0.4 mg/kg, ip) was used to induce amnesia in mice and piracetam (200 mg/kg, ip) served as positive control. In the acute study, Lasuna (65 mg/kg, po) partially reversed the scopolamine-induced amnesia but failed to improve learning and memory in untreated animals. Chronic administration of Lasuna (40 mg/kg/day for 21 days) significantly improved learning both in control and scopolamine induced amnesic animals. Influence of Lasuna on central cholinergic activity and its antioxidant properties were also studied by estimating the cortical acetylcholinesterase (AchE) activity and reduced glutathione (GSH) levels respectively. Chronic administration of Lasuna inhibited AchE, while increasing GSH levels. Thus the results indicate that long-term administration of crude garlic extract may improve learning and memory in mice while the underlying mechanism of action may be attributed to the anti-AchE activity and anti-oxidant property of garlic.

Quercetin induces cell apoptosis of myeloma and displays a synergistic effect with dexamethasone in vitro and in vivo xenograft models

PubMed Central

Zhang, Enfan; Zi, Fuming; Chen, Jing; Chen, Qingxiao; Lin, Xuanru; Yang, Li; Li, Yi; Wu, Wenjun; Yang, Yang; He, Jingsong; Cai, Zhen

2016-01-01

Quercetin, a kind of dietary flavonoid, has shown its anticancer activity in many kinds of cancers including hematological malignancies (acute myelogenous leukemia, chronic myelogenous leukemia, chronic lymphocytic leukemia, and MM) in vitro and in vivo. However, its effects on MM need further investigation. In this study, MM cell lines were treated with quercetin alone or in combination with dexamethasone. In order to observe the effects in vivo, a xenograft model of human myeloma was established. Quercetin inhibited proliferation of MM cells (RPMI8226, ARP-1, and MM.1R) by inducing cell cycle arrest in the G2/M phase and apoptosis. Western blot showed that quercetin downregulated c-myc expression and upregulated p21 expression. Quercetin also activated caspase-3, caspase-9, and poly(ADP-ribose)polymerase 1. Caspase inhibitors partially blocked apoptosis induced by quercetin. Furthermore, quercetin combined with dexamethasone significantly increased MM cell apoptosis. In vivo xenograft models, quercetin obviously inhibited tumor growth. Caspase-3 was activated to a greater extent when quercetin was combined with dexamethasone. In conclusion, quercetin alone or in combination with dexamethasone may be an effective therapy for MM. PMID:27329589

Dihydroartemisinin potentiates the anticancer effect of cisplatin via mTOR inhibition in cisplatin-resistant ovarian cancer cells: involvement of apoptosis and autophagy.

PubMed

Feng, Xue; Li, Ling; Jiang, Hong; Jiang, Keping; Jin, Ye; Zheng, Jianhua

2014-02-14

Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistant human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Allicin Alleviates Reticuloendotheliosis Virus-Induced Immunosuppression via ERK/Mitogen-Activated Protein Kinase Pathway in Specific Pathogen-Free Chickens

PubMed Central

Wang, Liyuan; Jiao, Hongchao; Zhao, Jingpeng; Wang, Xiaojuan; Sun, Shuhong; Lin, Hai

2017-01-01

Reticuloendotheliosis virus (REV), a gammaretrovirus in the Retroviridae family, causes an immunosuppressive, oncogenic, and runting–stunting syndrome in multiple avian hosts. Allicin, the main effective component of garlic, has a broad spectrum of pharmacological properties. The hypothesis that allicin could relieve REV-induced immune dysfunction was investigated in vivo and in vitro in the present study. The results showed that dietary allicin supplementation ameliorated REV-induced dysplasia and immune dysfunction in REV-infected chickens. Compared with the control groups, REV infection promoted the expression of inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, interferon (IFN)-γ, and tumor necrosis factor-α (TNF-α), whereas, allicin reversed these changes induced by REV infection. The decreased levels of IFN-α, IFN-β, and IL-2 were observed in REV-infected chickens, which were significantly improved by allicin. Allicin suppressed the REV-induced high expression of toll-like receptors (TLRs) as well as melanoma differentiation-associated gene 5 (MDA5) and the activation of mitogen-activated protein kinase (MAPK) and the nuclear factor kappa B p65. REV stimulated the phosphorylation of JNK, ERK, and p38, the downstream key signaling molecules of MAPK pathway, while allicin retarded the augmented phosphorylation level induced by REV infection. The decreased phosphorylation level of ERK was associated with REV replication, suggesting that ERK signaling is involved in REV replication, and allicin can alleviate the REV-induced immune dysfunction by inhibiting the activation of ERK. In addition, REV infection induced oxidative damage in thymus and spleen, whereas allicin treatment significantly decreased the oxidative stress induced by REV infection, suggesting that the antioxidant effect of allicin should be at least partially responsible for the harmful effect of REV infection. In conclusion, the findings suggest that allicin alleviates the inflammation and oxidative damage caused by REV infection and exerts the potential anti-REV effect by blocking the ERK/MAPK pathway. PMID:29312337

Behaviors induced or disrupted by complex partial seizures.

PubMed

Leung, L S; Ma, J; McLachlan, R S

2000-09-01

We reviewed the neural mechanisms underlying some postictal behaviors that are induced or disrupted by temporal lobe seizures in humans and animals. It is proposed that the psychomotor behaviors and automatisms induced by temporal lobe seizures are mediated by the nucleus accumbens. A non-convulsive hippocampal afterdischarge in rats induced an increase in locomotor activity, which was suppressed by the injection of dopamine D(2) receptor antagonist in the nucleus accumbens, and blocked by inactivation of the medial septum. In contrast, a convulsive hippocampal or amygdala seizure induced behavioral hypoactivity, perhaps by the spread of the seizure into the frontal cortex and opiate-mediated postictal depression. Mechanisms underlying postictal psychosis, memory disruption and other long-term behavioral alterations after temporal lobe seizures, are discussed. In conclusion, many of the changes of postictal behaviors observed after temporal lobe seizures in humans may be found in animals, and the basis of the behavioral change may be explained as a change in neural processing in the temporal lobe and the connecting subcortical structures.

Induction of endothelial cell proliferation by angiogenic factors released by activated monocytes

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

Pakala, Rajbabu; Watanabe, Takuya; Benedict, Claude R

2002-06-01

Introduction: Cell-cell interaction is an essential component of atherosclerotic plaque development. Activated monocytes appear to play a central role in the development of atherosclerosis, not only through foam cell formation but also via the production of various growth factors that induce proliferation of different cell types that are involved in the plaque development. Using serum free co-culture method, we determined the effect of monocytes on endothelial cell proliferation. Methods: Endothelial cell proliferation is determined by the amount of [{sup 3}H]thymidine incorporated in to the DNA. Basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) levels inmore » the conditioned medium were determined by ELISA. Results: Conditioned medium from unactivated monocytes partially inhibited endothelial cell proliferation, whereas conditioned medium from activated monocytes promoted endothelial cell proliferation. The mitogenic effect of conditioned medium derived from activated monocytes is due to the presence of b-FGF, VEGF and IL-8. Neutralizing antibodies against b-FGF, VEGF and IL-8 partially reversed the mitogenic effect of conditioned medium derived from activated monocytes. When b-FGF, VEGF and IL-8 were immunoprecipitated from conditioned medium derived from activated monocytes, it is less mitogenic to endothelial cells. Conclusion: Activated monocytes may play an important role in the development of atherosclerotic plaque by producing endothelial cell growth factors.« less

Inhibition of Smooth Muscle Proliferation by Urea-Based Alkanoic Acids via Peroxisome Proliferator-Activated Receptor α–Dependent Repression of Cyclin D1

PubMed Central

Ng, Valerie Y.; Morisseau, Christophe; Falck, John R.; Hammock, Bruce D.; Kroetz, Deanna L.

2007-01-01

Objective Proliferation of smooth muscle cells is implicated in cardiovascular complications. Previously, a urea-based soluble epoxide hydrolase inhibitor was shown to attenuate smooth muscle cell proliferation. We examined the possibility that urea-based alkanoic acids activate the nuclear receptor peroxisome proliferator-activated receptor α (PPARα) and the role of PPARα in smooth muscle cell proliferation. Methods and Results Alkanoic acids transactivated PPARα, induced binding of PPARα to its response element, and significantly induced the expression of PPARα-responsive genes, showing their function as PPARα agonists. Furthermore, the alkanoic acids attenuated platelet-derived growth factor–induced smooth muscle cell proliferation via repression of cyclin D1 expression. Using small interfering RNA to decrease endogenous PPARα expression, it was determined that PPARα was partially involved in the cyclin D1 repression. The antiproliferative effects of alkanoic acids may also be attributed to their inhibitory effects on soluble epoxide hydrolase, because epoxyeicosatrienoic acids alone inhibited smooth muscle cell proliferation. Conclusions These results show that attenuation of smooth muscle cell proliferation by urea-based alkanoic acids is mediated, in part, by the activation of PPARα. These acids may be useful for designing therapeutics to treat diseases characterized by excessive smooth muscle cell proliferation. PMID:16917105

Glial Reactivity in Resistance to Methamphetamine-Induced Neurotoxicity

PubMed Central

Friend, Danielle M.; Keefe, Kristen A.

2013-01-01

Neurotoxic regimens of methamphetamine (METH) result in reactive microglia and astrocytes in striatum. Prior data indicate that rats with partial dopamine (DA) loss resulting from prior exposure to METH are resistant to further decreases in striatal DA when re-exposed to METH 30 days later. Such resistant animals also do not show an activated microglia phenotype, suggesting a relation between microglial activation and METH-induced neurotoxicity. To date, the astrocyte response in such resistance has not been examined. Thus, this study examined glial-fibrillary acidic protein (GFAP) and CD11b protein expression in striata of animals administered saline or a neurotoxic regimen of METH on postnatal days 60 and/or 90 (Saline:Saline, Saline:METH, METH:Saline, METH:METH). Consistent with previous work, animals experiencing acute toxicity (Saline:METH) showed both activated microglia and astocytes, whereas those resistant to the acute toxicity (METH:METH) did not show activated microglia. Interestingly, GFAP expression remained elevated in rats exposed to METH at PND60 (METH:Saline), and was not elevated further in resistant rats treated for the second time with METH (METH:METH). These data suggest that astrocytes remain reactive up to 30 days post-METH exposure. Additionally, these data indicate that astrocyte reactivity does not reflect acute, METH-induced DA terminal toxicity, whereas microglial reactivity does. PMID:23414433

Minocycline Attenuates Neonatal Germinal-Matrix-Hemorrhage-Induced Neuroinflammation and Brain Edema by Activating Cannabinoid Receptor 2.

PubMed

Tang, Jun; Chen, Qianwei; Guo, Jing; Yang, Liming; Tao, Yihao; Li, Lin; Miao, Hongping; Feng, Hua; Chen, Zhi; Zhu, Gang

2016-04-01

Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns leading to detrimental neurological sequelae. Minocycline has been reported to play a key role in neurological inflammatory diseases by controlling some mechanisms that involve cannabinoid receptor 2 (CB2R). The current study investigated whether minocycline reduces neuroinflammation and protects the brain from injury in a rat model of collagenase-induced GMH by regulating CB2R activity. To test this hypothesis, the effects of minocycline and a CB2R antagonist (AM630) were evaluated in male rat pups that were post-natal day 7 (P7) after GMH. We found that minocycline can lead to increased CB2R mRNA expression and protein expression in microglia. Minocycline significantly reduced GMH-induced brain edema, microglial activation, and lateral ventricular volume. Additionally, minocycline enhanced cortical thickness after injury. All of these neuroprotective effects of minocycline were prevented by AM630. A cannabinoid CB2 agonist (JWH133) was used to strengthen the hypothesis, which showed the identical neuroprotective effects of minocycline. Our study demonstrates, for the first time, that minocycline attenuates neuroinflammation and brain injury in a rat model of GMH, and activation of CBR2 was partially involved in these processes.

Arsenic trioxide promoting ETosis in acute promyelocytic leukemia through mTOR-regulated autophagy.

PubMed

Li, Tao; Ma, Ruishuang; Zhang, Yan; Mo, Hongdan; Yang, Xiaoyan; Hu, Shaoshan; Wang, Lixiu; Novakovic, Valerie A; Chen, He; Kou, Junjie; Bi, Yayan; Yu, Bo; Fang, Shaohong; Wang, Jinghua; Zhou, Jin; Shi, Jialan

2018-01-23

Despite the high efficacy and safety of arsenic trioxide (ATO) in treating acute promyelocytic leukemia (APL) and eradicating APL leukemia-initiating cells (LICs), the mechanism underlying its selective cytotoxicity remains elusive. We have recently demonstrated that APL cells undergo a novel cell death program, termed ETosis, through autophagy. However, the role of ETosis in ATO-induced APL LIC eradication remains unclear. For this study, we evaluated the effects of ATO on ETosis and the contributions of drug-induced ETosis to APL LIC eradication. In NB4 cells, ATO primarily increased ETosis at moderate concentrations (0.5-0.75 μM) and stimulated apoptosis at higher doses (1.0-2.0 μM). Furthermore, ATO induced ETosis through mammalian target of rapamycin (mTOR)-dependent autophagy, which was partially regulated by reactive oxygen species. Additionally, rapamycin-enhanced ATO-induced ETosis in NB4 cells and APL cells from newly diagnosed and relapsed patients. In contrast, rapamycin had no effect on apoptosis in these cells. We also noted that PML/RARA oncoprotein was effectively cleared with this combination. Intriguingly, activation of autophagy with rapamycin-enhanced APL LIC eradication clearance by ATO in vitro and in a xenograft APL model, while inhibition of autophagy spared clonogenic cells. Our current results show that ATO exerts antileukemic effects at least partially through ETosis and targets LICs primarily through ETosis. Addition of drugs that target the ETotic pathway could be a promising therapeutic strategy to further eradicate LICs and reduce relapse.

Negative modulation of α5 GABAA receptors in rats may partially prevent memory impairment induced by MK-801, but not amphetamine- or MK-801-elicited hyperlocomotion

PubMed Central

Stamenić, Tamara Timić; Joksimović, Srdjan; Biawat, Poonam; Stanković, Tamara; Marković, Bojan; Cook, James M; Savić, Miroslav M

2016-01-01

Reportedly, negative modulation of α5 GABAA receptors may improve cognition in normal and pharmacologically-impaired animals, and such modulation has been proposed as an avenue for treatment of cognitive symptoms in schizophrenia. This study assessed the actions of PWZ-029, administered at doses (2, 5 and 10 mg/kg) at which it reached micromolar concentrations in brain tissue with estimated free concentrations adequate for selective modulation of α5 GABAA receptors, in three cognitive tasks in male Wistar rats acutely treated with the noncompetitive N-methyl-D-aspartate – receptor antagonist, MK-801 (0.1 mg/kg), as well in tests of locomotor activity potentiated by MK-801 (0.2 mg/kg) or amphetamine (0.5 mg/kg). In a hormetic-like manner, only 5 mg/kg PWZ-029 reversed MK-801-induced deficits in novel object recognition test (visual recognition memory), whereas in the Morris water maze, the 2 mg/kg dose of PWZ-029 exerted partial beneficial effects on spatial learning impairment. PWZ-029 did not affect recognition memory deficits in social novelty discrimination procedure. Motor hyperactivity induced with MK-801 or amphetamine was not preventable by PWZ-029. Our results show that certain MK-801-induced memory deficits can be ameliorated by negative modulation of α5 GABAA receptors, and point to the need for further elucidation of their translational relevance to cognitive deterioration in schizophrenia. PMID:26105958

Negative modulation of α₅ GABAA receptors in rats may partially prevent memory impairment induced by MK-801, but not amphetamine- or MK-801-elicited hyperlocomotion.

PubMed

Timić Stamenić, Tamara; Joksimović, Srdjan; Biawat, Poonam; Stanković, Tamara; Marković, Bojan; Cook, James M; Savić, Miroslav M

2015-09-01

Reportedly, negative modulation of α5 GABAA receptors may improve cognition in normal and pharmacologically-impaired animals, and such modulation has been proposed as an avenue for treatment of cognitive symptoms in schizophrenia. This study assessed the actions of PWZ-029, administered at doses (2, 5, and 10 mg/kg) at which it reached micromolar concentrations in brain tissue with estimated free concentrations adequate for selective modulation of α5 GABAA receptors, in three cognitive tasks in male Wistar rats acutely treated with the noncompetitive N-methyl-d-aspartate receptor antagonist, MK-801 (0.1 mg/kg), as well in tests of locomotor activity potentiated by MK-801 (0.2 mg/kg) or amphetamine (0.5 mg/kg). In a hormetic-like manner, only 5 mg/kg PWZ-029 reversed MK-801-induced deficits in novel object recognition test (visual recognition memory), whereas in the Morris water maze, the 2 mg/kg dose of PWZ-029 exerted partial beneficial effects on spatial learning impairment. PWZ-029 did not affect recognition memory deficits in social novelty discrimination procedure. Motor hyperactivity induced with MK-801 or amphetamine was not preventable by PWZ-029. Our results show that certain MK-801-induced memory deficits can be ameliorated by negative modulation of α5 GABAA receptors, and point to the need for further elucidation of their translational relevance to cognitive deterioration in schizophrenia. © The Author(s) 2015.

Cometabolic degradation of trichloroethene by Rhodococcus sp. strain L4 immobilized on plant materials rich in essential oils.

PubMed

Suttinun, Oramas; Müller, Rudolf; Luepromchai, Ekawan

2010-07-01

The cometabolic degradation of trichloroethene (TCE) by Rhodococcus sp. L4 was limited by the loss of enzyme activity during TCE transformation. This problem was overcome by repeated addition of inducing substrates, such as cumene, limonene, or cumin aldehyde, to the cells. Alternatively, Rhodococcus sp. L4 was immobilized on plant materials which contain those inducers in their essential oils. Cumin seeds were the most suitable immobilizing material, and the immobilized cells tolerated up to 68 muM TCE and degraded TCE continuously. The activity of immobilized cells, which had been inactivated partially during TCE degradation, could be reactivated by incubation in mineral salts medium without TCE. These findings demonstrate that immobilization of Rhodococcus sp. L4 on plant materials rich in essential oils is a promising method for efficient cometabolic degradation of TCE.

Cometabolic Degradation of Trichloroethene by Rhodococcus sp. Strain L4 Immobilized on Plant Materials Rich in Essential Oils▿ †

PubMed Central

Suttinun, Oramas; Müller, Rudolf; Luepromchai, Ekawan

2010-01-01

The cometabolic degradation of trichloroethene (TCE) by Rhodococcus sp. L4 was limited by the loss of enzyme activity during TCE transformation. This problem was overcome by repeated addition of inducing substrates, such as cumene, limonene, or cumin aldehyde, to the cells. Alternatively, Rhodococcus sp. L4 was immobilized on plant materials which contain those inducers in their essential oils. Cumin seeds were the most suitable immobilizing material, and the immobilized cells tolerated up to 68 μM TCE and degraded TCE continuously. The activity of immobilized cells, which had been inactivated partially during TCE degradation, could be reactivated by incubation in mineral salts medium without TCE. These findings demonstrate that immobilization of Rhodococcus sp. L4 on plant materials rich in essential oils is a promising method for efficient cometabolic degradation of TCE. PMID:20472723

Sorbitol counteracts high hydrostatic pressure-induced denaturation of inulin fructotransferase.

PubMed

Li, Yungao; Miao, Ming; Liu, Miao; Jiang, Bo; Zhang, Tao; Chen, Xiangyin

2014-09-01

Inulin fructotransferase (IFTase), a novel hydrolase for inulin, was exposed to high hydrostatic pressure (HHP) at 400 and 600 MPa for 15 min in the presence or absence of sorbitol. Sorbitol protected the enzyme against HHP-induced activity loss. The relative residual activity increased nearly 3.1- and 3.8-fold in the presence of 3 mol/L sorbitol under 400 MPa and 600 MPa for 15 min, respectively. Circular dichroism results indicated that the original chaotic unfolding conformation of the enzyme under HHP shifted toward more ordered and impact with 3 mol/L sorbitol. Fluorescence and UV spectra results suggested that sorbitol prevented partially the unfolding of the enzyme and stabilized the conformation under high pressure. These results might be attributed to the binding of sorbitol on the surface of IFTase to rearrange and strengthen intra- and intermolecular hydrogen bonds. Copyright © 2014 Elsevier B.V. All rights reserved.

GABAB Receptor Positive Modulation Decreases Selective Molecular and Behavioral Effects of Cocaine

PubMed Central

Lhuillier, Loic; Mombereau, Cedric; Cryan, John F.; Kaupmann, Klemens

2006-01-01

Exposure to cocaine induces selective behavioral and molecular adaptations. In rodents, acute cocaine induces increased locomotor activity whereas prolonged drug exposure results in behavioral locomotor sensitization, which is thought to be a consequence of drug–induced neuroadaptive changes. Recent attention has been given to compounds activating GABAB receptors as potential anti-addictive therapies. In particular the principle of allosteric positive GABAB receptor modulators is very promising in this respect, as positive modulators lack the sedative and muscle relaxant properties of full GABAB receptor agonists such as baclofen. Here we investigated the effects of systemic application of the GABAB receptor positive modulator GS39783 in animals treated with acute and chronic cocaine administration. Both GS39783 and baclofen dose-dependently attenuated acute cocaine-induced hyperlocomotion. Furthermore, both compounds also efficiently blocked cocaine-induced Fos induction in the striatal complex. In chronic studies GS39783 induced a modest attenuation of cocaine-induced locomotor sensitization. Chronic cocaine induces the accumulation of the transcription factor ΔFosB and up regulates cAMP-response-element-binding-protein (CREB) and dopamine-and-cAMP-regulated-phosphoprotein of 32 kd (DARPP-32). GS39783 blocked the induction/activation of DARPP-32 and CREB in the nucleus accumbens and dorsal striatum and partially inhibited ΔFosB accumulation in the dorsal striatum. In summary our data provide evidence that GS39783 attenuates the acute behavioral effects of cocaine exposure in rodents and in addition prevents the induction of selective long-term adaptive changes in dopaminergic signaling pathways. Further investigation of GABAB receptor positive modulation as a novel therapeutic strategy for the treatment of cocaine dependence and possibly other drugs of abuse is therefore warranted. PMID:16710312

The effect of varenicline on the development and expression of nicotine-induced behavioral sensitization and cross-sensitization in rats.

PubMed

Goutier, Wouter; Kloeze, Margreet B; McCreary, Andrew C

2015-03-01

The present study focused on the evaluation of behavioral sensitization and cross-sensitization induced by nicotine and varenicline in rats. Furthermore, it examined the influence of varenicline, a partial alpha4beta2 nicotinic receptor agonist, on nicotine-induced sensitization. To assess the development of behavioral sensitization, rats were chronically treated with vehicle, varenicline (0.03-3.0 mg/kg), nicotine (0.4 mg/kg) or combinations for 5 days and locomotor activity was measured. The expression of sensitization was assessed following a withdrawal period (17-26 days). The present results confirmed previous data showing the development and expression of nicotine-induced sensitization of locomotor activity in the rat. Varenicline did not induce sensitization on its own. When varenicline and nicotine were repeatedly administered sequentially, varenicline blocked the development and expression of nicotine-induced sensitization. Acute varenicline blocked the expression of nicotine-induced sensitization in a dose-dependent manner. Acute varenicline did not significantly increase locomotor activity, nor did it attenuate nicotine-induced sensitization. However, varenicline did cross-sensitize to the effects of nicotine, and vice versa. The present study showed that varenicline produced a dose-dependent bidirectional cross-sensitization with nicotine. Taken together, these findings provide pre-clinical evidence that varenicline is able to attenuate the effects of nicotine, yet simultaneously 'substitutes' for the effects of nicotine in the rat. Longitudinal studies would be needed to see if similar effects are seen in the clinical setting, and whether such effects contribute to the actions of varenicline as a smoking cessation aid. © 2013 Society for the Study of Addiction.

Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways.

PubMed

Chang, Chun-Yu; Shen, Chao-Yu; Kang, Chao-Kai; Sher, Yuh-Pyng; Sheu, Wayne H-H; Chang, Chia-Che; Lee, Tsung-Han

2014-09-15

Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

The effects of apigenin on lipopolysaccharide-induced depressive-like behavior in mice.

PubMed

Li, Ruipeng; Zhao, Di; Qu, Rong; Fu, Qiang; Ma, Shiping

2015-05-06

Increasing evidence shows that inflammation may contribute to the pathophysiology of depression. Apigenin, one type of natural flavone, has a number of biological actions including anti-inflammatory effects. Although it has potential antidepressant activity in a chronic mild stress model, the mechanisms of antidepressant effect for apigenin remain unclear. Here, we examined the effects of apigenin on lipopolysaccharide (LPS)-induced depressive-like behavior in male mice. A single administration of LPS (0.5mg/kg, i.p.) increased the immobility time in the tail suspension test (TST) and reduced sucrose preference without changing spontaneous locomotor activity in open field test (OFT). Pre-treatment with apigenin (25, 50mg/kg, i.p.) or fluoxetine (positive control drug, 20mg/kg, i.p.) once daily for 7 consecutive days prevented the abnormal behavior induced by LPS. Apigenin or fluoxetine also effectively attenuated LPS-induced production of pro-inflammatory cytokines IL-1β (interleukin-1β) and TNF-α (tumor necrosis factor-α). Moreover, apigenin or fluoxetine significantly suppressed the inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression at both the mRNA and protein level via the modulation of nuclear factor-κB (NF-κB) activation in the prefrontal cortex. Additionally, apigenin (50mg/kg, i.p.) or fluoxetine (20mg/kg, i.p.) effectively reversed the depressive-like behavior induced by TNF-α (0.1fg/site, i.c.v.) without altering the locomotor activity. These results demonstrate that apigenin exhibits antidepressant-like effects in LPS treated mice, partially due to its anti-inflammatory properties. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Fucoidan-induced osteogenic differentiation promotes angiogenesis by inducing vascular endothelial growth factor secretion and accelerates bone repair.

PubMed

Kim, Beom-Su; Yang, Sun-Sik; You, Hyung-Keun; Shin, Hong-In; Lee, Jun

2018-03-01

Osteogenesis and angiogenesis, including cell-cell communication between blood vessel cells and bone cells, are essential for bone repair. Fucoidan is a chemical compound that has a variety of biological activities. It stimulates osteoblast differentiation in human mesenchymal stem cells (MSCs), which in turn induces angiogenesis. However, the mechanism by which this communication between osteoblasts and endothelial cells is mediated remains unclear. Thus, the aim of this study was to clarify the relationship between fucoidan-induced osteoblastic differentiation in MSCs and angiogenesis in endothelial cells. First, the effect was confirmed of fucoidan on osteoblast differentiation in MSCs and obtained conditioned media from these cells (Fucoidan-MSC-CM). Next, the angiogenic activity of Fucoidan-MSC-CM was investigated and it was found that it stimulated angiogenesis, demonstrated by proliferation, tube formation, migration and sprout capillary formation in human umbilical vein endothelial cells. Messenger ribonucleic acid expression and protein secretion of vascular endothelial growth factor (VEGF) were dramatically increased during fucoidan-induced osteoblast differentiation and that its angiogenic activities were reduced by a VEGF/VEGF receptor-specific binding inhibitor. Furthermore, Fucoidan-MSC-CM increased the phosphorylation of mitogen-activated protein kinase and PI3K/AKT/eNOS signalling pathway, and that its angiogenic effects were markedly suppressed by SB203580 and AKT 1/2 inhibitor. Finally, an in vivo study was conducted and it was found that fucoidan accelerated new blood vessel formation and partially promoted bone formation in a rabbit model of a calvarial bone defect. This is the first study to investigate the angiogenic effect of fucoidan-induced osteoblastic differentiation through VEGF secretion, suggesting the therapeutic potential of fucoidan for enhancing bone repair. Copyright © 2017 John Wiley & Sons, Ltd.

Potentiated Interaction between Ineffective Doses of Budesonide and Formoterol to Control the Inhaled Cadmium-Induced Up-Regulation of Metalloproteinases and Acute Pulmonary Inflammation in Rats

PubMed Central

Zhang, Wenhui; Zhi, Jianming; Cui, Yongyao; Zhang, Fan; Habyarimana, Adélite; Cambier, Carole; Gustin, Pascal

2014-01-01

The anti-inflammatory properties of glucocorticoids are well known but their protective effects exerted with a low potency against heavy metals-induced pulmonary inflammation remain unclear. In this study, a model of acute pulmonary inflammation induced by a single inhalation of cadmium in male Sprague-Dawley rats was used to investigate whether formoterol can improve the anti-inflammatory effects of budesonide. The cadmium-related inflammatory responses, including matrix metalloproteinase-9 (MMP-9) activity, were evaluated. Compared to the values obtained in rats exposed to cadmium, pretreatment of inhaled budesonide (0.5 mg/15 ml) elicited a significant decrease in total cell and neutrophil counts in bronchoalveolar lavage fluid (BALF) associated with a significant reduction of MMP-9 activity which was highly correlated with the number of inflammatory cells in BALF. Additionally, cadmium-induced lung injuries characterized by inflammatory cell infiltration within alveoli and the interstitium were attenuated by the pre-treatment of budesonide. Though the low concentration of budesonide (0.25 mg/15 ml) exerted a very limited inhibitory effects in the present rat model, its combination with an inefficient concentration of formoterol (0.5 mg/30 ml) showed an enhanced inhibitory effect on neutrophil and total cell counts as well as on the histological lung injuries associated with a potentiation of inhibition on the MMP-9 activity. In conclusion, high concentration of budesonide alone could partially protect the lungs against cadmium exposure induced-acute neutrophilic pulmonary inflammation via the inhibition of MMP-9 activity. The combination with formoterol could enhance the protective effects of both drugs, suggesting a new therapeutic strategy for the treatment of heavy metals-induced lung diseases. PMID:25313925

Mechanochemical Association Reaction of Interfacial Molecules Driven by Shear.

PubMed

Khajeh, Arash; He, Xin; Yeon, Jejoon; Kim, Seong H; Martini, Ashlie

2018-05-29

Shear-driven chemical reaction mechanisms are poorly understood because the relevant reactions are often hidden between two solid surfaces moving in relative motion. Here, this phenomenon is explored by characterizing shear-induced polymerization reactions that occur during vapor phase lubrication of α-pinene between sliding hydroxylated and dehydroxylated silica surfaces, complemented by reactive molecular dynamics simulations. The results suggest that oxidative chemisorption of the α-pinene molecules at reactive surface sites, which transfers oxygen atoms from the surface to the adsorbate molecule, is the critical activation step. Such activation takes place more readily on the dehydroxylated surface. During this activation, the most strained part of the α-pinene molecules undergoes a partial distortion from its equilibrium geometry, which appears to be related to the critical activation volume for mechanical activation. Once α-pinene molecules are activated, association reactions occur between the newly attached oxygen and one of the carbon atoms in another molecule, forming ether bonds. These findings have general implications for mechanochemistry because they reveal that shear-driven reactions may occur through reaction pathways very different from their thermally induced counterparts and specifically the critical role of molecular distortion in such reactions.

Cbl Associates with Pyk2 and Src to Regulate Src Kinase Activity, αvβ3 Integrin-Mediated Signaling, Cell Adhesion, and Osteoclast Motility

PubMed Central

Sanjay, Archana; Houghton, Adam; Neff, Lynn; DiDomenico, Emilia; Bardelay, Chantal; Antoine, Evelyne; Levy, Joan; Gailit, James; Bowtell, David; Horne, William C.; Baron, Roland

2001-01-01

The signaling events downstream of integrins that regulate cell attachment and motility are only partially understood. Using osteoclasts and transfected 293 cells, we find that a molecular complex comprising Src, Pyk2, and Cbl functions to regulate cell adhesion and motility. The activation of integrin αvβ3 induces the [Ca2+]i-dependent phosphorylation of Pyk2 Y402, its association with Src SH2, Src activation, and the Src SH3-dependent recruitment and phosphorylation of c-Cbl. Furthermore, the PTB domain of Cbl is shown to bind to phosphorylated Tyr-416 in the activation loop of Src, the autophosphorylation site of Src, inhibiting Src kinase activity and integrin-mediated adhesion. Finally, we show that deletion of c Src or c-Cbl leads to a decrease in osteoclast migration. Thus, binding of αvβ3 integrin induces the formation of a Pyk2/Src/Cbl complex in which Cbl is a key regulator of Src kinase activity and of cell adhesion and migration. These findings may explain the osteopetrotic phenotype in the Src−/− mice. PMID:11149930

Effect of the inducers veratryl alcohol, Xylidine, and ligninosulphonates on activity and thermal stability and inactivation kinetics of laccase from Trametes versicolor.

PubMed

Saraiva, Jorge A; Tavares, Ana P M; Xavier, Ana M R B

2012-06-01

Laccase production from Trametes versicolor was improved in the presence of the inducers ligninosulphonates, veratryl alcohol, and xylidine respectively two-, four-, and eightfold. The thermal inactivation of the produced laccase, after partial purification with ammonium sulfate was kinetically investigated at various temperatures (60-70 °C) and pH values (3.5, 4.5, and 5.5). The inactivation process followed first-order kinetics for all conditions tested, except for veratryl alcohol, for which a constant activity level was observed at the end of the inactivation, also after first-order decay. Enzyme thermostability was affected by the type of inducer used in the culture medium for the production of laccase and also by the pH of incubation mixture. Generally, laccase stability increased with pH increment, being more stable at pH 5.5, except with xylidine. At pHs 4.5 and 5.5, the three inducers significantly increased laccase thermal stability, with the higher effect being observed for pH 5.5 and ligninosulphonates, where increment of half-life times ranged from 3- to 20-fold, depending on the temperature.

Electro-cutaneous stimulation on the palm elicits referred sensations on intact but not on amputated digits

NASA Astrophysics Data System (ADS)

D'Alonzo, M.; Engels, L. F.; Controzzi, M.; Cipriani, C.

2018-02-01

Objective. Grasping and manipulation control critically depends on tactile feedback. Without this feedback, the ability for fine control of a prosthesis is limited in upper limb amputees. Early studies have shown that non-invasive electro-cutaneous stimulation (ES) can induce referred sensations that are spread to a wider and/or more distant area, with respect to the electrodes. Building on this, we sought to exploit this effect to provide somatotopically matched sensory feedback to people with partial hand (digital) amputations. Approach. For the first time, this work investigated the possibility of inducing referred sensations in the digits by activating the palmar nerves. Specifically, we electrically stimulated 18 sites on the palm of non-amputees to evaluate the effects of sites and stimulation parameters on modality, magnitude, and location of the evoked sensations. We performed similar tests with partial hand amputees by testing those sites that had most consistently elicited referred sensations in non-amputees. Main results. We demonstrated referred sensations in non-amputees from all stimulation sites in one form or another. Specifically, the stimulation of 16 of the 18 sites gave rise to reliable referred sensations. Amputees experienced referred sensations to unimpaired digits, just like non-amputees, but we were unable to evoke referred sensations in their missing digits: none of them reported sensations that extended beyond the tip of the stump. Significance. The possibility of eliciting referred sensations on the digits may be exploited in haptic systems for providing touch sensations without obstructing the fingertips or their movements. The study also suggests that the phenomenon of referred sensations through ES may not be exploited for partial hand prostheses, and it invites researchers to explore alternative approaches. Finally, the results seem to confirm previous studies suggesting that the stumps in partial hand amputees partially acquire the role of the missing fingertips, physiologically and cognitively.

Effects of aripiprazole on caffeine-induced hyperlocomotion and neural activation in the striatum.

PubMed

Batista, Luara A; Viana, Thércia G; Silveira, Vívian T; Aguiar, Daniele C; Moreira, Fabrício A

2016-01-01

Aripiprazole is an antipsychotic that acts as a partial agonist at dopamine D2 receptors. In addition to its antipsychotic activity, this compound blocks the effects of some psychostimulant drugs. It has not been verified, however, if aripiprazole interferes with the effects of caffeine. Hence, this study tested the hypothesis that aripiprazole prevents caffeine-induced hyperlocomotion and investigated the effects of these drugs on neural activity in the striatum. Male Swiss mice received injections of vehicle or antipsychotic drugs followed by vehicle or caffeine. Locomotion was analyzed in a circular arena and c-Fos protein expression was quantified in the dorsolateral, dorsomedial, and ventrolateral striatum, and in the core and shell regions of nucleus accumbens. Aripiprazole (0.1, 1, and 10 mg/kg) prevented caffeine (10 mg/kg)-induced hyperlocomotion at doses that do not change basal locomotion. Haloperidol (0.01, 0.03, and 0.1 mg/kg) also decreased caffeine-induced hyperlocomotion at all doses, although at the two higher doses, this compound reduced basal locomotion. Immunohistochemistry analysis showed that aripiprazole increases c-Fos protein expression in all regions studied, whereas caffeine did not alter c-Fos protein expression. Combined treatment of aripiprazole and caffeine resulted in a decrease in the number of c-Fos positive cells as compared to the group receiving aripiprazole alone. In conclusion, aripiprazole prevents caffeine-induced hyperlocomotion and increases neural activation in the striatum. This latter effect is reduced by subsequent administration of caffeine. These results advance our understanding on the pharmacological profile of aripiprazole.

Kaempferol induces apoptosis in HepG2 cells via activation of the endoplasmic reticulum stress pathway.

PubMed

Guo, Haiqing; Ren, Feng; Zhang, Li; Zhang, Xiangying; Yang, Rongrong; Xie, Bangxiang; Li, Zhuo; Hu, Zhongjie; Duan, Zhongping; Zhang, Jing

2016-03-01

Kaempferol is a flavonoid compound that has gained importance due to its antitumor properties; however, the underlying mechanisms remain to be fully understood. The present study aimed to investigate the molecular mechanisms of the antitumor function of kaempferol in HepG2 hepatocellular carcinoma cells. Kaempferol was determined to reduce cell viability, increase lactate dehydrogenase activity and induce apoptosis in a concentration‑ and time‑dependent manner in HepG2 cells. Additionally, kaempferol‑induced apoptosis possibly acts via the endoplasmic reticulum (ER) stress pathway, due to the significant increase in the protein expression levels of glucose‑regulated protein 78, glucose‑regulated protein 94, protein kinase R‑like ER kinase, inositol‑requiring enzyme 1α, partial activating transcription factor 6 cleavage, caspase‑4, C/EBP homologous protein (CHOP) and cleaved caspase‑3. The pro‑apoptotic activity of kaempferol was determined to be due to induction of the ER stress‑CHOP pathway, as: i) ER stress was blocked by 4‑phenyl butyric acid (4‑PBA) pretreatment and knockdown of CHOP with small interfering RNA, which resulted in alleviation of kaempferol‑induced HepG2 cell apoptosis; and ii) transfection with plasmid overexpressing CHOP reversed the protective effect of 4‑PBA in kaempferol‑induced HepG2 cells and increased the apoptotic rate. Thus, kaempferol promoted HepG2 cell apoptosis via induction of the ER stress‑CHOP signaling pathway. These observations indicate that kaempferol may be used as a potential chemopreventive treatment strategy for patients with hepatocellular carcinoma.

Neostigmine but not sugammadex impairs upper airway dilator muscle activity and breathing

PubMed Central

Eikermann, M.; Zaremba, S.; Malhotra, A.; Jordan, A. S.; Rosow, C.; Chamberlin, N. L.

2008-01-01

Background Cholinesterase inhibitor-based reversal agents, given in the absence of neuromuscular block, evoke a partial upper airway obstruction by decreasing skeletal upper airway muscle function. Sugammadex reverses neuromuscular block by encapsulating rocuronium. However, its effects on upper airway integrity and breathing are unknown. Methods Fifty-one adult male rats were anaesthetized with isoflurane, tracheostomized, and a femoral artery and vein were cannulated. First, we compared the efficacy of sugammadex 15 mg kg−1 and neostigmine 0.06 mg kg−1 to reverse respiratory effects of rocuronium-induced partial paralysis [train-of-four ratio (T4/T1)=0.5]. Subsequently, we compared the safety of sugammadex and neostigmine given after recovery of the T4/T1 to 1, by measuring phasic genioglossus activity and breathing. Results During partial paralysis (T4/T1=0.5), time to recovery of minute volume to baseline values was 10.9 (2), 75.8 (18), and 153 (54) s with sugammadex, neostigmine, and placebo, respectively (sugammadex was significantly faster than neostigmine and placebo, P<0.05). Recovery of T4/T1 was also faster for sugammadex than neostigmine and placebo. Neostigmine administration after complete recovery of T4/T1 decreased upper airway dilator muscle activity to 64 (30)% of baseline and decreased tidal volume (P<0.05 for both variables), whereas sugammadex had no effect on either variable. Conclusions In contrast to neostigmine, which significantly impairs upper airway dilator muscle activity when given after recovery from neuromuscular block, a reversal dose of sugammadex given under the same conditions does not affect genioglossus muscle activity and normal breathing. Human studies will be required to evaluate the clinical relevance of our findings. PMID:18559352

Sleep deprivation and divergent toll-like receptor-4 activation of cellular inflammation in aging.

PubMed

Carroll, Judith E; Carrillo, Carmen; Olmstead, Richard; Witarama, Tuff; Breen, Elizabeth C; Yokomizo, Megumi; Seeman, Teresa; Irwin, Michael R

2015-02-01

Sleep disturbance and aging are associated with increases in inflammation, as well as increased risk of infectious disease. However, there is limited understanding of the role of sleep loss on age-related differences in immune responses. This study examines the effects of sleep deprivation on toll-like receptor activation of monocytic inflammation in younger compared to older adults. Community-dwelling adults (n = 70) who were categorized as younger (25-39 y old, n = 21) and older (60-84 y old, n = 49) participants, underwent a sleep laboratory-based experimental partial sleep deprivation (PSD) protocol including adaptation, an uninterrupted night of sleep, sleep deprivation (sleep restricted to 03:00-07:00), and recovery. Blood samples were obtained each morning to measure toll-like receptor-4 activation of monocyte intracellular production of the inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Partial sleep deprivation induced a significant increase in the production of IL-6 and/or TNF-α that persisted after a night of recovery sleep (F(2,121.2) = 3.8, P < 0.05). Age moderated the effects of sleep loss, such that younger adults had an increase in inflammatory cytokine production that was not present in older adults (F(2,121.2) = 4.0, P < 0.05). Older adults exhibit reduced toll-like receptor 4 stimulated cellular inflammation that, unlike in younger adults, is not activated after a night of partial sleep loss. Whereas sleep loss increases cellular inflammation in younger adults and may contribute to inflammatory disorders, blunted toll-like receptor activation in older adults may increase the risk of infectious disease seen with aging. © 2015 Associated Professional Sleep Societies, LLC.

Identification of a regulatory T cell specific cell surface molecule that mediates suppressive signals and induces Foxp3 expression.

PubMed

Wang, Rui; Wan, Qi; Kozhaya, Lina; Fujii, Hodaka; Unutmaz, Derya

2008-07-16

Regulatory T (T(reg)) cells control immune activation and maintain tolerance. How T(regs) mediate their suppressive function is unclear. Here we identified a cell surface molecule, called GARP, (or LRRC32), which within T cells is specifically expressed in T(regs) activated through the T cell receptor (TCR). Ectopic expression of GARP in human naïve T (T(N)) cells inhibited their proliferation and cytokine secretion upon TCR activation. Remarkably, GARP over-expression in T(N) cells induced expression of T(reg) master transcription factor Foxp3 and endowed them with a partial suppressive function. The extracellular but not the cytoplasmic region of GARP, was necessary for these functions. Silencing Foxp3 in human T(reg) cells reduced expression of GARP and attenuated their suppressive function. However, GARP function was not affected when Foxp3 was downregulated in GARP-overexpressing cells, while silencing GARP in Foxp3-overexpressing cells reduced their suppressive activity. These findings reveal a novel cell surface molecule-mediated regulatory mechanism, with implications for modulating aberrant immune responses.

Free phenolic acids from the seaweed Halimeda monile with antioxidant effect protecting against liver injury.

PubMed

Mancini-Filho, Jorge; Novoa, Alexis Vidal; González, Ana Elsa Batista; de Andrade-Wartha, Elma Regina S; de O e Silva, Ana Mara; Pinto, José Ricardo; Mancini, Dalva Assunção Portari

2009-01-01

Phenolic compounds are found in seaweed species together with other substances presenting antioxidant activity. The objective of this work was to evaluate the antioxidant activity of the free phenolic acids (FPA) fraction from the seaweed Halimeda monile, and its activity to protect the expression of hepatic enzymes in rats, under experimental CCl4 injury. The antioxidant activity was measured by the DPPH method. The FPA fraction (80 mg/kg, p.o.) was administered during 20 consecutive days to rats. The peroxidation was performed by thiobarbituric acid reactive substances (TBARS). The SOD and CAT enzymatic expressions were measured by RT/PCR. The histology technique was used to evaluate liver injuries. The expression of both, CAT and SOD genes, was more preserved by FPA. Only partial injury could be observed by histology in the liver of rats receiving FPA as compared with the control group; and CCl4 administration induced 60% more peroxidation as compared with the rats receiving FPA. These data suggest that FPA could modulate the antioxidant enzymes and oxidative status in the liver through protection against adverse effects induced by chemical agents.

Who knows not where an anemone does wear his sting? Could polypeptides released from the columnar vesicles of Bunodosoma cangicum induce apoptosis in the ZF-L cell line?

PubMed

Bastos, Claudio L Q; Varela, Antonio Sergio; Ferreira, Shana Pires; Nornberg, Bruna Felix; Boyle, Robert Tew

2016-12-15

We provide ultrastructural and cytological evidence that the tentacles of the sea anemone Bunodosoma cangicum does not contain cytotoxic venom. However, we show that the stimulated secretion of an apparent mixture of biomolecules containing polypeptides from the columnar vesicles of Bunodosoma cangicum is apparently a potent inducer of apoptosis in the zebrafish cell line, ZF-L. Microscopic fluorescence, cell morphology and flow cytometric assays confirm the apoptotic activity. Crude vesicle venom was partially purified by size exclusion chromatography. PAGE analysis shows that this venom contains low weight polypeptides but no measurable protein. The apoptotic activity is heat labile, and the observed peptides concurrent with this activity have a molecular weight of approximately 2000 Da. This manuscript is the first report of biologically active molecules and peptides associated with columnar vesicles of anemones, and the first to confirm that the tentacles of B. cangicum do not contain cytotoxic venom, and express spirocytes exclusively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Glucocorticoids inhibit sulfur mustard-induced airway muscle hyperresponsiveness to substance P.

PubMed

Calvet, J H; D'Ortho, M P; Jarreau, P H; Levame, M; Harf, A; Macquin-Mavier, I

1994-11-01

To explore the mechanisms of airway hyperreactivity to aerosolized substance P observed in guinea pigs 14 days after intratracheal injection of sulfur mustard (SM), we studied the effects of epithelium removal and inhibition of neutral endopeptidase (NEP) activity on airway muscle responsiveness. Tracheal rings from SM-intoxicated guinea pigs expressed a greater contractile response to substance P than rings from nonintoxicated guinea pigs. After epithelium removal or incubation with the NEP inhibitor phosphoramidon, the contractile responses of tracheal rings to substance P did not differ in guinea pigs injected with SM or ethanol (SM solvent). Treatment of the guinea pigs with betamethasone for 7 days before measurement abolished the airway muscle hyperresponsiveness observed in untreated SM-intoxicated guinea pigs and partially restored tracheal epithelium NEP activity. In addition, the tracheal epithelium height and cell density of SM-intoxicated guinea pigs treated with betamethasone were significantly greater than in those without betamethasone. These results demonstrate that SM intoxication induces airway muscle hyperresponsiveness to substance P by reducing tracheal epithelial NEP activity and that glucocorticoids might inhibit this hyperresponsiveness by increasing this activity.

NMDA/glutamate mechanism of magnesium-induced anxiolytic-like behavior in mice.

PubMed

Poleszak, Ewa; Wlaź, Piotr; Wróbel, Andrzej; Fidecka, Sylwia; Nowak, Gabriel

2008-01-01

The anxiolytic-like activity of magnesium in mice during the elevated plus maze (EPM) has been demonstrated previously. In the present study, we examined the involvement of NMDA/glutamate receptor ligands on the magnesium effect on the EPM. We demonstrated that low, ineffective doses of NMDA antagonists (the competitive NMDA antagonist CGP 37849, 0.3 mg/kg; an antagonist of the glycineB sites, L-701,324, 1 mg/kg; a partial agonist of the glycineB sites, D-cycloserine, 2.5 mg/kg; and the non-competitive NMDA antagonist MK-801, 0.05 mg/kg) administered together with an ineffective dose of magnesium (10 mg/kg) evoked a significant increase in the percentage of time spent in the open arm of the maze (an index of anxiety). Moreover, magnesium-induced anxiolytic-like activity (20 mg/kg) was antagonized by D-serine (100 nmol/mouse), an agonist of glycineB site of the NMDA receptor complex. The present study demonstrates the involvement of the NMDA/glutamate pathway in the magnesium anxiolytic-like activity in the EPM in mice, and that this activity particularly involves the glycineB sites.

Resveratrol relieves Angiostrongylus cantonensis - Induced meningoencephalitis by activating sirtuin-1.

PubMed

Chen, An-Chih; Shyu, Ling-Yuh; Hsin, Yue-Loong; Chen, Ke-Min; Lai, Shih-Chan

2017-09-01

Resveratrol, a natural herbal compound found in high levels in grapes and red wine, is frequently used as activator of sirtuin-1. This study investigated the potential function of sirtuin-1 in regulating angiostrongyliasis meningoencephalitis in resveratrol-treated mice. Mice were subjected to meningoencephalitis to study the protective effect of resveratrol against meningoencephalitis and investigate the effects of sirtuin-1 activation on brain. Results demonstrated that sirtuin-1 level decreased in mice with meningoencephalitis and significantly increased in resveratrol-treated mice. Moreover, resveratrol treatment significantly reduced eosinophil counts, p65, Interferon-γ, interleukin (IL)-5, IL-33, and tumor necrosis factor-α levels, matrix metalloproteinase-9 activity, claudin-5 degradation, and blood-brain barrier permeability. By contrast, the anti-inflammatory factor IL-10 was significantly increased in resveratrol-treated mice. Resveratrol treatment was partially beneficial in controlling the pathological processes of angiostrongyliasis meningoencephalitis. The results demonstrate the neuroprotective and anti-inflammatory effects of resveratrol against Angiostrongylus cantonensis-induced eosinophilic meningoencephalitis in mice. Treatment with sirtuin-1 agonist was given within a therapeutic window after A. cantonensis infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Alteration of striatal dopamine levels under various partial pressure of oxygen in pre-convulsive and convulsive phases in freely-moving rats.

PubMed

Lavoute, Cécile; Weiss, Michel; Risso, Jean-Jacques; Rostain, Jean-Claude

2014-02-01

The purpose of this study was to investigate the change in the striatal dopamine (DA) level in freely-moving rat exposed to different partial pressure of oxygen (from 1 to 5 ATA). Some works have suggested that DA release by the substantia nigra pars compacta (SNc) neurons in the striatum could be disturbed by hyperbaric oxygen (HBO) exposure, altering therefore the basal ganglia activity. Such changes could result in a change in glutamatergic and GABAergic control of the dopaminergic neurons into the SNc. Such alterations could provide more information about the oxygen-induced seizures observed at 5 ATA in rat. DA-sensitive electrodes were implanted into the striatum under general anesthesia. After 1 week rest, awaked rats were exposed to oxygen-nitrogen mixture at a partial pressure of oxygen of 1, 2, 3, 4 and 5 ATA. DA level was monitored continuously (every 3 min) by in vivo voltammetry before and during HBO exposure. HBO induced a decrease in DA level in relationship to the increase in partial pressure of oxygen from 1 ATA to 4 ATA (-15 % at 1 ATA, -30 % at 2 ATA, -40 % at 3 ATA, -45 % at 4 ATA), without signs of oxygen toxicity. At 5 ATA, DA level strongly decreases (-75 %) before seizure which occurred after 27 min ± 7 HBO exposure. After the epileptic seizure the decrease in DA level disappeared. These changes and the biphasic effect of HBO were discussed in function of HBO action on neurochemical regulations of the nigro striatal pathway.

Endothelium-derived hyperpolarizing factor and protein kinase G Iα activation: H2O2 versus S-nitrosothiols.

PubMed

Bautista-Niño, Paula K; van der Stel, Marien; Batenburg, Wendy W; de Vries, René; Roks, Anton J M; Danser, A H Jan

2018-05-15

Protein kinase G (PKG) Iα mediates the cyclic guanosine monophosphate-mediated vasodilatory effects induced by NO. Endothelium-derived hyperpolarizing factors (EDHFs), like H 2 O 2 can activate PKGIα in a cyclic guanosine monophosphate-independent manner, but whether this is true for all EDHFs (e.g., S-nitrosothiols) is unknown. Here, we investigated the contribution of PKGIα to bradykinin-, H 2 O 2 -, L-S-nitrosocysteine-, and light-induced relaxation in porcine coronary arteries, making use of the fact that thioredoxin reductase inhibition with auranofin or 1-chloro-2,4-dinitrobenzene potentiates PKGIα. Thioredoxin reductase inhibition potentiated bradykinin and H 2 O 2 , but not L-S-nitrosocysteine or light. The relaxations by the latter 2 and bradykinin, but not those by H 2 O 2 , were prevented by the soluble guanylyl cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one. Yet, after S-nitrosothiol depletion with ethacrynic acid, thioredoxin reductase inhibition also potentiated light-induced relaxation, and this was prevented by the Na + -K + ATPase inhibitor ouabain. This indicates that photorelaxation depends on sGC activation by S-nitrosothiols, while only after S-nitrosothiol depletion oxidized PKGIα comes into play, and acts via Na + -K + ATPase. In conclusion, both bradykinin- and light-induced relaxation of porcine coronary arteries depend, at least partially, on oxidized PKGIα, and this does not involve sGC. H 2 O 2 also acts via oxidized PKGIα in an sGC-independent manner. Yet, S-nitrosothiol-induced relaxation is PKGIα-independent. Clearly, PKG activation does not contribute universally to all EDHF responses, and targeting PKGIα may only mimick EDHF under certain conditions. It is therefore unlikely that PKGIα activators will be universal vasodilators. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of polychlorinated biphenyl (PCB) on regulation of thyroid-, growth-, and neurochemically related developmental processes in young rats

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

Juarez de Ku, L.M.

1992-01-01

Neonatal exposure to the toxic chemical polychlorinated biphenyl (PCB) induces hypothyroidism and retarded growth. Neonatal rats made hypothyroid by chemical or surgical means experience retarded growth and subnormal activity of choline acetyltransferase (ChAT) This study compared thyroid-, growth-, and neurochemically-related processes altered by hypothyroidism induced by other means, with PCB-induced hypothyroidism: (1) titers of thyroid stimulating hormone (TSH); (2) titers of hormones that regulate growth [growth hormone (GH), insulin-growth like factor-I (IGF-1), growth hormone releasing hormone (GHRH) and somatostatin (SS)]; or (3) brain ChAT activity. Whether PCB-induced growth retardation and other alterations are secondary to accompanying hypothyroidism rather than ormore » in addition to a direct effect of PCB was also examined. Pregnant rats were fed chow containing 0 (controls), 62.5, 125, or 250 ppm PCB (entering offspring through placenta and milk) throughout pregnancy and lactation. Neonates exposed to PCB displayed many alterations similar to those made hypothyroid by other means: depression of overall and skeletal growth, circulating by other means: depression of overall and skeletal growth, circulating T[sub 4] levels and ChAT activity, and no change in hypothalamic GHRH and SS concentrations. Differences included a paradoxical increase in circulating GH levels, and no significant alteration of circulation IGF-1 and TSH levels and pituitary GH and TSH levels (although trends were in the expected direction). Thus, PCB-induced hypothyroidism may partially cause altered skeletal growth, circulating GH and TSH concentrations, and ChAT activity. Both T[sub 4] and T[sub 3] injections returned circulating TSH and GH levels and pituitary TSH content toward control levels; T[sub 3] restored skeletal, but not overall growth; and T[sub 4] elevated ChAT activity.« less