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Sample records for a2 inhibition protects

  1. cAMP-Inhibits Cytoplasmic Phospholipase A2 and Protects Neurons against Amyloid-β-Induced Synapse Damage

    PubMed Central

    Bate, Clive; Williams, Alun

    2015-01-01

    A key event in Alzheimer’s disease (AD) is the production of amyloid-β (Aβ) peptides and the loss of synapses. In cultured neurons Aβ triggered synapse damage as measured by the loss of synaptic proteins. α-synuclein (αSN), aggregates of which accumulate in Parkinson’s disease, also caused synapse damage. Synapse damage was associated with activation of cytoplasmic phospholipase A2 (cPLA2), an enzyme that regulates synapse function and structure, and the production of prostaglandin (PG) E2. In synaptosomes PGE2 increased concentrations of cyclic adenosine monophosphate (cAMP) which suppressed the activation of cPLA2 demonstrating an inhibitory feedback system. Thus, Aβ/αSN-induced activated cPLA2 produces PGE2 which increases cAMP which in turn suppresses cPLA2 and, hence, its own production. Neurons pre-treated with pentoxifylline and caffeine (broad spectrum phosphodiesterase (PDE) inhibitors) or the PDE4 specific inhibitor rolipram significantly increased the Aβ/αSN-induced increase in cAMP and consequently protected neurons against synapse damage. The addition of cAMP analogues also inhibited cPLA2 and protected neurons against synapse damage. These results suggest that drugs that inhibit Aβ-induced activation of cPLA2 and cross the blood–brain barrier may reduce synapse damage in AD. PMID:26389963

  2. Phloroglucinol protects retinal pigment epithelium and photoreceptor against all-trans-retinal-induced toxicity and inhibits A2E formation.

    PubMed

    Cia, David; Cubizolle, Aurélie; Crauste, Céline; Jacquemot, Nathalie; Guillou, Laurent; Vigor, Claire; Angebault, Claire; Hamel, Christian P; Vercauteren, Joseph; Brabet, Philippe

    2016-09-01

    Among retinal macular diseases, the juvenile recessive Stargardt disease and the age-related degenerative disease arise from carbonyl and oxidative stresses (COS). Both stresses originate from an accumulation of all-trans-retinal (atRAL) and are involved in bisretinoid formation by condensation of atRAL with phosphatidylethanolamine (carbonyl stress) in the photoreceptor and its transformation into lipofuscin bisretinoids (oxidative stress) in the retinal pigment epithelium (RPE). As atRAL and bisretinoid accumulation contribute to RPE and photoreceptor cell death, our goal is to select powerful chemical inhibitors of COS. Here, we describe that phloroglucinol, a natural phenolic compound having anti-COS properties, protects both rat RPE and mouse photoreceptor primary cultures from atRAL-induced cell death and reduces hydrogen peroxide (H2 O2 )-induced damage in RPE in a dose-dependent manner. Mechanistic analyses demonstrate that the protective effect encompasses decrease in atRAL-induced intracellular reactive oxygen species and free atRAL levels. Moreover, we show that phloroglucinol reacts with atRAL to form a chromene adduct which prevents bisretinoid A2E synthesis in vitro. Taken together, these data show that the protective effect of phloroglucinol correlates with its ability to trap atRAL and to prevent its further transformation into deleterious bisretinoids. Phloroglucinol might be a good basis to develop efficient therapeutic derivatives in the treatment of retinal macular diseases.

  3. Berberine inhibits cytosolic phospholipase A2 and protects against LPS-induced lung injury and lethality independent of the alpha2-adrenergic receptor in mice.

    PubMed

    Zhang, Hao-qing; Wang, Hua-dong; Lu, Da-xiang; Qi, Ren-bin; Wang, Yan-ping; Yan, Yu-xia; Fu, Yong-mei

    2008-05-01

    Acute lung injury is still a significant clinical problem having a high mortality rate despite significant advances in antimicrobial therapy and supportive care made in the past few years. Our previous study demonstrated that berberine (Ber) remarkably decreased mortality and attenuated the lung injury in mice challenged with LPS, but the mechanism behind this remains unclear. Here, we report that pretreatment with Ber significantly reduced pulmonary edema, neutrophil infiltration, and histopathological alterations; inhibited protein expression and phosphorylation of cytosolic phospholipase A2; and decreased thromboxane A2 release induced by LPS. Yohimbine, an alpha2-adrenergic receptor antagonist, did not antagonize these actions of Ber. Furthermore, pretreatment with Ber decreased TNF-alpha production and mortality in mice challenged with LPS, which were enhanced by yohimbine, and Ber combined with yohimbine also improved survival rate in mice subjected to cecal ligation and puncture. Taken together, these observations indicate that Ber attenuates LPS-induced lung injury by inhibiting TNF-alpha production and cytosolic phospholipase A2 expression and activation in an alpha2-adrenoceptor-independent manner. Berberine combined with yohimbine might provide an effective therapeutic approach to acute lung injury during sepsis.

  4. Inhibition of neuronal ferroptosis protects hemorrhagic brain.

    PubMed

    Li, Qian; Han, Xiaoning; Lan, Xi; Gao, Yufeng; Wan, Jieru; Durham, Frederick; Cheng, Tian; Yang, Jie; Wang, Zhongyu; Jiang, Chao; Ying, Mingyao; Koehler, Raymond C; Stockwell, Brent R; Wang, Jian

    2017-04-06

    Intracerebral hemorrhage (ICH) causes high mortality and morbidity, but our knowledge of post-ICH neuronal death and related mechanisms is limited. In this study, we first demonstrated that ferroptosis, a newly identified form of cell death, occurs in the collagenase-induced ICH model in mice. We found that administration of ferrostatin-1, a specific inhibitor of ferroptosis, prevented neuronal death and reduced iron deposition induced by hemoglobin in organotypic hippocampal slice cultures (OHSCs). Mice treated with ferrostatin-1 after ICH exhibited marked brain protection and improved neurologic function. Additionally, we found that ferrostatin-1 reduced lipid reactive oxygen species production and attenuated the increased expression level of PTGS2 and its gene product cyclooxygenase-2 ex vivo and in vivo. Moreover, ferrostatin-1 in combination with other inhibitors that target different forms of cell death prevented hemoglobin-induced cell death in OHSCs and human induced pluripotent stem cell-derived neurons better than any inhibitor alone. These results indicate that ferroptosis contributes to neuronal death after ICH, that administration of ferrostatin-1 protects hemorrhagic brain, and that cyclooxygenase-2 could be a biomarker of ferroptosis. The insights gained from this study will advance our knowledge of the post-ICH cell death cascade and be essential for future preclinical studies.

  5. Inhibition of neuronal ferroptosis protects hemorrhagic brain

    PubMed Central

    Li, Qian; Han, Xiaoning; Lan, Xi; Gao, Yufeng; Wan, Jieru; Durham, Frederick; Cheng, Tian; Yang, Jie; Wang, Zhongyu; Jiang, Chao; Ying, Mingyao; Stockwell, Brent R.

    2017-01-01

    Intracerebral hemorrhage (ICH) causes high mortality and morbidity, but our knowledge of post-ICH neuronal death and related mechanisms is limited. In this study, we first demonstrated that ferroptosis, a newly identified form of cell death, occurs in the collagenase-induced ICH model in mice. We found that administration of ferrostatin-1, a specific inhibitor of ferroptosis, prevented neuronal death and reduced iron deposition induced by hemoglobin in organotypic hippocampal slice cultures (OHSCs). Mice treated with ferrostatin-1 after ICH exhibited marked brain protection and improved neurologic function. Additionally, we found that ferrostatin-1 reduced lipid reactive oxygen species production and attenuated the increased expression level of PTGS2 and its gene product cyclooxygenase-2 ex vivo and in vivo. Moreover, ferrostatin-1 in combination with other inhibitors that target different forms of cell death prevented hemoglobin-induced cell death in OHSCs and human induced pluripotent stem cell–derived neurons better than any inhibitor alone. These results indicate that ferroptosis contributes to neuronal death after ICH, that administration of ferrostatin-1 protects hemorrhagic brain, and that cyclooxygenase-2 could be a biomarker of ferroptosis. The insights gained from this study will advance our knowledge of the post-ICH cell death cascade and be essential for future preclinical studies. PMID:28405617

  6. Chemical Modification and Irreversible Inhibition of Striatal A2a Adenosine Receptors

    PubMed Central

    JACOBSON, KENNETH A.; STILES, GARY L.; JI, XIAO-DUO

    2012-01-01

    SUMMARY The ligand recognition site of A2a-adenosine receptors in rabbit striatal membranes was probed using non-site-directed labeling reagents and specific affinity labels. Exposure of membranes to diethylpyrocarbonate at a concentration of 2.5 mm, followed by washing, was found to inhibit the binding of [3H]CGS 21680 and [3H]xanthine amine congener to A2a receptors, by 86 and 30%, respectively. Protection from diethylpyrocarbonate inactivation by an adenosine receptor agonist, 5′-N-ethylcarboxamidoadenosine, and an antagonist, theophylline, suggested the presence of two histidyl residues on the receptor, one associated with agonist binding and the other with antagonist binding. Binding of [3H]CGS 21680 or [3H]xanthine amine congener was partially restored after incubation with 250 mm hydroxylamine, further supporting histidine as the modification site. Preincubation with disulfide-reactive reagents, dithiothreitol or sodium dithionite, at >5 mm inhibited radioligand binding, indicating the presence of essential disulfide bridges in A2a receptors, whereas the concentration of mercaptoethanol required to inhibit binding was >50 mm. A number of isothiocyanate-bearing affinity labels derived from the A2a-selective agonist 2-[(2-aminoethylamino)carbonylethylphenylethylamino]-5′-N-ethylcarboxamidoadenosine (APEC) were synthesized and found to inhibit A2a receptor binding in rabbit and bovine striatal membranes. Binding to rabbit A1 receptors was not inhibited. Preincubation with the affinity label 4-isothiocyanatophenylaminothiocarbonyl-APEC (100 nm) diminished the Bmax for [3H]CGS 21680 binding by 71%, and the Kd was unaffected, suggesting a direct modification of the ligand binding site. Reversal of 4-isothiocyanatophenylaminothiocarbonyl-APEC inhibition of [3H]CGS 21680 binding with hydroxylamine suggested that the site of modification by the isothiocyanate is a cysteine residue. A bromoacetyl derivative of APEC was ineffective as an affinity label at

  7. A Tripartite Fusion, FaeG-FedF-LT192A2:B, of Enterotoxigenic Escherichia coli (ETEC) Elicits Antibodies That Neutralize Cholera Toxin, Inhibit Adherence of K88 (F4) and F18 Fimbriae, and Protect Pigs against K88ac/Heat-Labile Toxin Infection ▿

    PubMed Central

    Ruan, Xiaosai; Liu, Mei; Casey, Thomas A.; Zhang, Weiping

    2011-01-01

    Enterotoxigenic Escherichia coli (ETEC) strains expressing K88 (F4) or F18 fimbriae and heat-labile (LT) and/or heat-stable (ST) toxins are the major cause of diarrhea in young pigs. Effective vaccines inducing antiadhesin (anti-K88 and anti-F18) and antitoxin (anti-LT and anti-ST) immunity would provide broad protection to young pigs against ETEC. In this study, we genetically fused nucleotides coding for peptides from K88ac major subunit FaeG, F18 minor subunit FedF, and LT toxoid (LT192) A2 and B subunits for a tripartite adhesin-adhesin-toxoid fusion (FaeG-FedF-LT192A2:B). This fusion was used for immunizations in mice and pigs to assess the induction of antiadhesin and antitoxin antibodies. In addition, protection by the elicited antiadhesin and antitoxin antibodies against a porcine ETEC strain was evaluated in a gnotobiotic piglet challenge model. The data showed that this FaeG-FedF-LT192A2:B fusion elicited anti-K88, anti-F18, and anti-LT antibodies in immunized mice and pigs. In addition, the anti-porcine antibodies elicited neutralized cholera toxin and inhibited adherence against both K88 and F18 fimbriae. Moreover, immunized piglets were protected when challenged with ETEC strain 30302 (K88ac/LT/STb) and did not develop clinical disease. In contrast, all control nonvaccinated piglets developed severe diarrhea and dehydration after being challenged with the same ETEC strain. This study clearly demonstrated that this FaeG-FedF-LT192A2:B fusion antigen elicited antibodies that neutralized LT toxin and inhibited the adherence of K88 and F18 fimbrial E. coli strains and that this fusion could serve as an antigen for vaccines against porcine ETEC diarrhea. In addition, the adhesin-toxoid fusion approach used in this study may provide important information for developing effective vaccines against human ETEC diarrhea. PMID:21813665

  8. Protection from latent inhibition provided by a conditioned inhibitor.

    PubMed

    McConnell, Bridget L; Wheeler, Daniel S; Urcelay, Gonzalo P; Miller, Ralph R

    2009-10-01

    Two conditioned suppression experiments with rats investigated the influence on latent inhibition of compounding a Pavlovian conditioned inhibitor with the target cue during preexposure treatment. Results were compared with those of subjects that received conventional latent inhibition training, no preexposure, or preexposure to the target cue in compound with a neutral stimulus. In Experiment 1, greater attenuation of the latent inhibition effect was observed in subjects that received target preexposure in compound with a Pavlovian conditioned inhibitor relative to subjects that received preexposure with a neutral stimulus or to the target alone. In Experiment 2, this protection from latent inhibition was attenuated if the excitor that was used to train the conditioned inhibitor was extinguished between preexposure and target training. The results are consistent with an account offered by the extended comparator hypothesis.

  9. Tiagabine Protects Dopaminergic Neurons against Neurotoxins by Inhibiting Microglial Activation.

    PubMed

    Liu, Jie; Huang, Dongping; Xu, Jing; Tong, Jiabin; Wang, Zishan; Huang, Li; Yang, Yufang; Bai, Xiaochen; Wang, Pan; Suo, Haiyun; Ma, Yuanyuan; Yu, Mei; Fei, Jian; Huang, Fang

    2015-10-26

    Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative disorders such as Parkinson's disease (PD). γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, has recently been shown to play an inhibitory role in the immune system. Tiagabine, a piperidine derivative, enhances GABAergic transmission by inhibiting GABA transporter 1 (GAT 1). In the present study, we found that tiagabine pretreatment attenuated microglial activation, provided partial protection to the nigrostriatal axis and improved motor deficits in a methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. The protective function of tiagabine was abolished in GAT 1 knockout mice that were challenged with MPTP. In an alternative PD model, induced by intranigral infusion of lipopolysaccharide (LPS), microglial suppression and subsequent neuroprotective effects of tiagabine were demonstrated. Furthermore, the LPS-induced inflammatory activation of BV-2 microglial cells and the toxicity of conditioned medium toward SH-SY5Y cells were inhibited by pretreatment with GABAergic drugs. The attenuation of the nuclear translocation of nuclear factor κB (NF-κB) and the inhibition of the generation of inflammatory mediators were the underlying mechanisms. Our results suggest that tiagabine acts as a brake for nigrostriatal microglial activation and that it might be a novel therapeutic approach for PD.

  10. Tiagabine Protects Dopaminergic Neurons against Neurotoxins by Inhibiting Microglial Activation

    PubMed Central

    Liu, Jie; Huang, Dongping; Xu, Jing; Tong, Jiabin; Wang, Zishan; Huang, Li; Yang, Yufang; Bai, Xiaochen; Wang, Pan; Suo, Haiyun; Ma, Yuanyuan; Yu, Mei; Fei, Jian; Huang, Fang

    2015-01-01

    Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative disorders such as Parkinson’s disease (PD). γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, has recently been shown to play an inhibitory role in the immune system. Tiagabine, a piperidine derivative, enhances GABAergic transmission by inhibiting GABA transporter 1 (GAT 1). In the present study, we found that tiagabine pretreatment attenuated microglial activation, provided partial protection to the nigrostriatal axis and improved motor deficits in a methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. The protective function of tiagabine was abolished in GAT 1 knockout mice that were challenged with MPTP. In an alternative PD model, induced by intranigral infusion of lipopolysaccharide (LPS), microglial suppression and subsequent neuroprotective effects of tiagabine were demonstrated. Furthermore, the LPS-induced inflammatory activation of BV-2 microglial cells and the toxicity of conditioned medium toward SH-SY5Y cells were inhibited by pretreatment with GABAergic drugs. The attenuation of the nuclear translocation of nuclear factor κB (NF-κB) and the inhibition of the generation of inflammatory mediators were the underlying mechanisms. Our results suggest that tiagabine acts as a brake for nigrostriatal microglial activation and that it might be a novel therapeutic approach for PD. PMID:26499517

  11. CISD1 inhibits ferroptosis by protection against mitochondrial lipid peroxidation.

    PubMed

    Yuan, Hua; Li, Xuemei; Zhang, Xiuying; Kang, Rui; Tang, Daolin

    2016-09-16

    Ferroptosis is a form of non-apoptotic cell death originally identified in cancer cells. However, the key regulator of ferroptosis in mitochondria remains unknown. Here, we show that CDGSH iron sulfur domain 1 (CISD1, also termed mitoNEET), an iron-containing outer mitochondrial membrane protein, negatively regulates ferroptotic cancer cell death. The classical ferroptosis inducer erastin promotes CISD1 expression in an iron-dependent manner in human hepatocellular carcinoma cells (e.g., HepG2 and Hep3B). Genetic inhibition of CISD1 increased iron-mediated intramitochondrial lipid peroxidation, which contributes to erastin-induced ferroptosis. In contrast, stabilization of the iron sulfur cluster of CISD1 by pioglitazone inhibits mitochondrial iron uptake, lipid peroxidation, and subsequent ferroptosis. These findings indicate a novel role of CISD1 in protecting against mitochondrial injury in ferroptosis.

  12. Saposin C Protects Glucocerebrosidase against α-Synuclein Inhibition

    PubMed Central

    Yap, Thai Leong; Gruschus, James M.; Velayati, Arash; Sidransky, Ellen; Lee, Jennifer C.

    2013-01-01

    Mutations in GBA1, the gene for glucocerebrosidase (GCase), are genetic risk factors for Parkinson disease (PD). α-Synuclein (α-syn), a protein implicated in PD, interacts with GCase and efficiently inhibits enzyme activity. GCase deficiency causes the lysosomal storage disorder Gaucher disease (GD). We show that saposin C (Sap C), a protein vital for GCase activity in vivo, protects GCase against α-syn inhibition. Using NMR spectroscopy, site-specific fluorescence, and Förster energy transfer probes, Sap C was observed to displace α-syn from GCase in solution and on lipid vesicles. Our results suggest that Sap C might play a crucial role in GD-related PD. PMID:24070323

  13. MC-002 exhibits positive effects against platelets aggregation and endothelial dysfunction through thromboxane A2 inhibition.

    PubMed

    Fang, Weirong; Wei, Jie; Han, Dan; Chen, Xi; He, Guangwei; Wu, Qiang; Chu, Shaoxing; Li, Yunman

    2014-04-01

    Thromboxane A2 (TXA2) induces platelet aggregation and vasoconstriction, and agents that inhibit TXA2 production or interaction with receptors may exert potential application in stroke therapy. To illustrate the platelet aggregation antagonistic and endothelial protective effect of (E) - 3 - (3 - methoxy - 4 - ((3, 5, 6 - trimethylpyrazin - 2 - yl) methoxy) phenyl) sodium acrylate (MC-002) through TXA2 inhibition and underline mechanisms. Platelets aggregation and thoracic aorta ring contraction of rabbits were induced by U46619. Human umbilical vein endothelial cells (HUVECs) were further applied to explore the protective effect of MC-002 on endothelium when exposed to tumor necrosis factor - α (TNF-α). MTT method was used to assess cell damage, and ELISA analysis was exerted to estimate nitrogen monoxide (NO), endothelin-1 (ET-1), thromboxane B2 (TXB2) and 6-keto-prostaglandin F1α (6-keto-PGF1α) releasing. Fluorescence spectrophotometry was conducted to determine intracellular calcium concentration ([Ca(2+)]i), and western blotting method was applied to evaluate the protein expressions of intracellular adhesion molecule-1 (ICAM-1), P-selectin and nuclear factor-kappa B (NF-κB). TXA2 analog U46619 mediated obvious platelet aggregation and vasoconstriction. MC-002 inhibited platelet aggregation through administration in vivo and incubation with platelet in vitro, and relaxed aorta ring in endothelium dependent manner. MC-002 alleviated cell damage, [Ca(2+)]i overload, ET-1 overexcretion and TXB2 activation, but improved NO availability reduction in HUVECs treated with TNF-α. Furthermore, MC-002 downregulated ICAM-1, P-selectin and NF-κB overexpression induced by TNF-α. In conclusion, MC-002 exerted antiplatelet aggregation effect through TXA2 inhibition and relieved inflammatory injury of endothelial cells through NF-κB signal pathway. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Salvianolic acid B inhibits autophagy and protects starving cardiac myocytes

    PubMed Central

    Han, Xiao; Liu, Jian-xun; Li, Xin-zhi

    2011-01-01

    Aim: To investigate the protective or lethal role of autophagy and the effects of Salvianolic acid B (Sal B) on autophagy in starving myocytes. Methods: Cardiac myocytes were incubated under starvation conditions (GD) for 0, 1, 2, 3, and 6 h. Autophagic flux in starving cells was measured via chloroquine (3 μmol/L). After myocytes were treated with Sal B (50 μmol/L) in the presence or absence of chloroquine (3 μmol/L) under GD 3 h, the amount of LC3-II, the abundance of LC3-positive fluorescent dots in cells, cell viability and cellular ATP levels were determined using immunoblotting, immunofluorescence microscopy, MTT assay and luminometer, respectively. Moreover, electron microscopy (EM) and immunofluorescent duel labeling of LC3 and Caspase-8 were used to examine the characteristics of autophagy and apoptosis. Results: Immunoblot analysis showed that the amount of LC3-II in starving cells increased in a time-dependent manner accompanied by increased LC3-positive fluorescence and decreased cell viability and ATP content. Sal B (50 μmol/L) inhibited the increase in LC3-II, reduced the abundance of LC3 immunofluorescence and intensity of Caspase-8 fluorescence, and enhanced cellular viability and ATP levels in myocytes under GD 3 h, regardless of whether chloroquine was present. Conclusion: Autophagy induced by starvation for 3 h led to cell injury. Sal B protected starving cells by blocking the early stage of autophagic flux and inhibiting apoptosis that occurred during autophagy. PMID:21113177

  15. L-carnitine inhibits hepatocarcinogenesis via protection of mitochondria.

    PubMed

    Chang, Baojun; Nishikawa, Manabu; Nishiguchi, Shuhei; Inoue, Masayasu

    2005-02-20

    Hepatocellular carcinoma is usually preceded by chronic inflammation. However, the molecular mechanism in hepatocarcinogenesis is not well known. Recently, we reported that mitochondrial dysfunction plays an important role in hepatocarcinogenesis via the production of free radicals. Furthermore, we proved that L-carnitine effectively protects mitochondrial function in vivo. Therefore, we investigated whether long-term administration of L-carnitine could prevent hepatitis and subsequent hepatocellular carcinoma in Long-Evans Cinnamon rats that are often analyzed as a model of hepatocarcinogenesis. The results indicated that oxidative stress elicited from abnormally accumulated copper increased the amount of free fatty acids, thereby inducing mitochondrial dysfunction, resulting in cell death and enhanced secondary generation of reactive oxygen species, which were significantly inhibited by carnitine treatment. Finally, the occurrence of placental glutathione S-transferase-positive foci as a marker for preneoplastic lesions and hepatocarcinogenesis were significantly inhibited by L-carnitine. These facts suggest that mitochondrial injury plays an essential role in the development of hepatocarcinogenesis and that the clinical use of carnitine has excellent therapeutic potential in individuals with chronic hepatitis. (c) 2004 Wiley-Liss, Inc.

  16. Inhibition of HtrA2/Omi ameliorates heart dysfunction following ischemia/reperfusion injury in rat heart in vivo.

    PubMed

    Bhuiyan, Md Shenuarin; Fukunaga, Kohji

    2007-02-28

    High temperature requirement A2 (HtrA2)/Omi is a mitochondrial serine protease that is released into the cytosol from mitochondria and in turn promotes caspase activation by proteolyzing inhibitor of apoptosis proteins. Here we asked whether treatment with an HtrA2/Omi inhibitor, 5-[5-(2-nitrophenyl)furfuryliodine]-1,3-diphenyl-2-thiobarbituric acid (UCF-101), restores heart dysfunction following ischemia/reperfusion injury in vivo. Rats underwent a 30-min ischemia by occluding the left anterior descending artery, followed by 24 h reperfusion. UCF-101 (0.75 or 1.5 micromol/kg, i.p.) was administered 10 min before reperfusion. UCF-101 treatment significantly recovered the mean arterial blood pressure and ameliorated contractile dysfunction of the left ventricle 72 h after reperfusion with concomitant reduction of infarct size. Cardio-protection mediated by UCF-101 was correlated with reduced X-linked inhibitor of apoptosis protein (XIAP) degradation and inhibition of Caspase-9, Caspase-3, and Caspase-7 processing. Furthermore, UCF-101 prevented loss of membrane integrity by inhibiting fodrin breakdown in cardiomyocytes. UCF-101-induced cytoprotection was also correlated with reduced Fas ligand expression and inhibition of FLIP degradation following ischemia/reperfusion. These results suggest that UCF-101 rescues cardiomyocytes from ischemia/reperfusion injury by inhibiting XIAP degradation and Fas/Fas-ligand-induced apoptosis, thereby ameliorating ischemia/reperfusion-induced myocardial dysfunction.

  17. Sesamin protects against renal ischemia reperfusion injury by promoting CD39-adenosine-A2AR signal pathway in mice.

    PubMed

    Li, Ke; Gong, Xia; Kuang, Ge; Jiang, Rong; Wan, Jingyuan; Wang, Bin

    2016-01-01

    Ischemia reperfusion injury (IRI) is a leading cause of acute kidney injury with high morbidity and mortality due to limited therapy. Here, we examine whether sesamin attenuates renal IRI in an animal model and explore the underlying mechanisms. Male mice were subjected to right renal ischemia for 30 min followed by reperfusion for 24 h with sesamin (100 mg/kg) during which the left kidney was removed. Renal damage and function were assessed subsequently. The results showed that sesamin reduced kidney ischemia reperfusion injury, as assessed by decreased serum creatinine (Scr) and Blood urea nitrogen (BUN), alleviated tubular damage and apoptosis. In addition, sesamin inhibited neutrophils infiltration and pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production in IR-preformed kidney. Notably, sesamin promoted the expression of CD39, A2A adenosine receptor (A2AAR), and A2BAR mRNA and protein as well as adenosine production. Furthermore, CD39 inhibitor or A2AR antagonist abolished partly the protection of sesamin in kidney IRI. In conclusion, sesamin could effectively protect kidney from IRI by inhibiting inflammatory responses, which might be associated with promoting the adenosine-CD39-A2AR signaling pathway.

  18. Sesamin protects against renal ischemia reperfusion injury by promoting CD39-adenosine-A2AR signal pathway in mice

    PubMed Central

    Li, Ke; Gong, Xia; Kuang, Ge; Jiang, Rong; Wan, Jingyuan; Wang, Bin

    2016-01-01

    Ischemia reperfusion injury (IRI) is a leading cause of acute kidney injury with high morbidity and mortality due to limited therapy. Here, we examine whether sesamin attenuates renal IRI in an animal model and explore the underlying mechanisms. Male mice were subjected to right renal ischemia for 30 min followed by reperfusion for 24 h with sesamin (100 mg/kg) during which the left kidney was removed. Renal damage and function were assessed subsequently. The results showed that sesamin reduced kidney ischemia reperfusion injury, as assessed by decreased serum creatinine (Scr) and Blood urea nitrogen (BUN), alleviated tubular damage and apoptosis. In addition, sesamin inhibited neutrophils infiltration and pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production in IR-preformed kidney. Notably, sesamin promoted the expression of CD39, A2A adenosine receptor (A2AAR), and A2BAR mRNA and protein as well as adenosine production. Furthermore, CD39 inhibitor or A2AR antagonist abolished partly the protection of sesamin in kidney IRI. In conclusion, sesamin could effectively protect kidney from IRI by inhibiting inflammatory responses, which might be associated with promoting the adenosine-CD39-A2AR signaling pathway. PMID:27347331

  19. Pyridostigmine bromide protection against acetylcholinesterase inhibition by pesticides.

    PubMed

    Henderson, John D; Glucksman, Gabriela; Leong, Bryan; Tigyi, Andras; Ankirskaia, Anna; Siddique, Imteaz; Lam, Helen; DePeters, Ed; Wilson, Barry W

    2012-01-01

    Pyridostigmine bromide (PB) has been used to protect soldiers from the toxic effects of soman, a chemical warfare agent. Recent research shows that pyridostigmine bromide protects a significant percentage of acetylcholinesterase in isolated human intercostal muscle. Findings presented here indicate that red blood cell acetylcholinesterase is similarly protected by pyridostigmine bromide from the action of diisopropyl fluorophosphate and several organophosphate pesticides including chlorpyrifos-oxon, diazinon-oxon, and paraoxon, but not malaoxon, using the bovine red blood cell as a subject. These findings suggest that pretreatment with PB may protect growers, farmworkers, first responders, and the public, in general, from the effects of selected pesticides. Copyright © 2011 Wiley Periodicals, Inc.

  20. Deletion of striatal adenosine A(2A) receptor spares latent inhibition and prepulse inhibition but impairs active avoidance learning.

    PubMed

    Singer, Philipp; Wei, Catherine J; Chen, Jiang-Fan; Boison, Detlev; Yee, Benjamin K

    2013-04-01

    Following early clinical leads, the adenosine A(2A)R receptor (A(2A)R) has continued to attract attention as a potential novel target for treating schizophrenia, especially against the negative and cognitive symptoms of the disease because of A(2A)R's unique modulatory action over glutamatergic in addition to dopaminergic signaling. Through (i) the antagonistic interaction with the dopamine D(2) receptor, and (ii) the regulation of glutamate release and N-methyl-d-aspartate receptor function, striatal A(2A)R is ideally positioned to fine-tune the dopamine-glutamate balance, the disturbance of which is implicated in the pathophysiology of schizophrenia. However, the precise function of striatal A(2A)Rs in the regulation of schizophrenia-relevant behavior is poorly understood. Here, we tested the impact of conditional striatum-specific A(2A)R knockout (st-A(2A)R-KO) on latent inhibition (LI) and prepulse inhibition (PPI) - behavior that is tightly regulated by striatal dopamine and glutamate. These are two common cross-species translational tests for the assessment of selective attention and sensorimotor gating deficits reported in schizophrenia patients; and enhanced performance in these tests is associated with antipsychotic drug action. We found that neither LI nor PPI was significantly affected in st-A(2A)R-KO mice, although a deficit in active avoidance learning was identified in these animals. The latter phenotype, however, was not replicated in another form of aversive conditioning - namely, conditioned taste aversion. Hence, the present study shows that neither learned inattention (as measured by LI) nor sensory gating (as indexed by PPI) requires the integrity of striatal A(2A)Rs - a finding that may undermine the hypothesized importance of A(2A)R in the genesis and/or treatment of schizophrenia.

  1. Mechanism of inhibition of human secretory phospholipase A2 by flavonoids: rationale for lead design

    NASA Astrophysics Data System (ADS)

    Lättig, Jens; Böhl, Markus; Fischer, Petra; Tischer, Sandra; Tietböhl, Claudia; Menschikowski, Mario; Gutzeit, Herwig O.; Metz, Peter; Pisabarro, M. Teresa

    2007-08-01

    The human secretory phospholipase A2 group IIA (PLA2-IIA) is a lipolytic enzyme. Its inhibition leads to a decrease in eicosanoids levels and, thereby, to reduced inflammation. Therefore, PLA2-IIA is of high pharmacological interest in treatment of chronic diseases such as asthma and rheumatoid arthritis. Quercetin and naringenin, amongst other flavonoids, are known for their anti-inflammatory activity by modulation of enzymes of the arachidonic acid cascade. However, the mechanism by which flavonoids inhibit Phospholipase A2 (PLA2) remained unclear so far. Flavonoids are widely produced in plant tissues and, thereby, suitable targets for pharmaceutical extractions and chemical syntheses. Our work focuses on understanding the binding modes of flavonoids to PLA2, their inhibition mechanism and the rationale to modify them to obtain potent and specific inhibitors. Our computational and experimental studies focused on a set of 24 compounds including natural flavonoids and naringenin-based derivatives. Experimental results on PLA2-inhibition showed good inhibitory activity for quercetin, kaempferol, and galangin, but relatively poor for naringenin. Several naringenin derivatives were synthesized and tested for affinity and inhibitory activity improvement. 6-(1,1-dimethylallyl)naringenin revealed comparable PLA2 inhibition to quercetin-like compounds. We characterized the binding mode of these compounds and the determinants for their affinity, selectivity, and inhibitory potency. Based on our results, we suggest C(6) as the most promising position of the flavonoid scaffold to introduce chemical modifications to improve affinity, selectivity, and inhibition of PLA2-IIA by flavonoids.

  2. Surfactant protein B inhibits secretory phospholipase A2 hydrolysis of surfactant phospholipids

    PubMed Central

    Grier, Bonnie L.; Waite, B. Moseley; Veldhuizen, Ruud A.; Possmayer, Fred; Yao, Li-Juan; Seeds, Michael C.

    2012-01-01

    Hydrolysis of surfactant phospholipids (PL) by secretory phospholipases A2 (sPLA2) contributes to surfactant damage in inflammatory airway diseases such as acute lung injury/acute respiratory distress syndrome. We and others have reported that each sPLA2 exhibits specificity in hydrolyzing different PLs in pulmonary surfactant and that the presence of hydrophilic surfactant protein A (SP-A) alters sPLA2-mediated hydrolysis. This report tests the hypothesis that hydrophobic SP-B also inhibits sPLA2-mediated surfactant hydrolysis. Three surfactant preparations were used containing varied amounts of SP-B and radiolabeled tracers of phosphatidylcholine (PC) or phosphatidylglycerol (PG): 1) washed ovine surfactant (OS) (pre- and postorganic extraction) compared with Survanta (protein poor), 2) Survanta supplemented with purified bovine SP-B (1–5%, wt/wt), and 3) a mixture of dipalmitoylphosphatidylcholine (DPPC), 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC), and 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) (DPPC:POPC:POPG, 40:40:20) prepared as vesicles and monomolecular films in the presence or absence of SP-B. Hydrolysis of PG and PC by Group IB sPLA2 (PLA2G1A) was significantly lower in the extracted OS, which contains SP-B, compared with Survanta (P = 0.005), which is SP-B poor. Hydrolysis of PG and PC in nonextracted OS, which contains all SPs, was lower than both Survanta and extracted OS. When Survanta was supplemented with 1% SP-B, PG and PC hydrolysis by PLA2G1B was significantly lower (P < 0.001) than in Survanta alone. When supplemented into pure lipid vesicles and monomolecular films composed of PG and PC mixtures, SP-B also inhibited hydrolysis by both PLA2G1B and Group IIA sPLA2 (PLA2G2A). In films, PLA2G1B hydrolyzed surfactant PL monolayers at surface pressures ≤30 mN/m (P < 0.01), and SP-B lowered the surface pressure range at which hydrolysis can occur. These results suggest the hydrophobic SP, SP-B, protects alveolar surfactant PL from

  3. Quercetin protects against atherosclerosis by inhibiting dendritic cell activation.

    PubMed

    Lin, Weiqun; Wang, Wenting; Wang, Dongliang; Ling, Wenhua

    2017-09-01

    Quercetin is a typical flavonol with atheroprotective effects, but the effect of quercetin on dendritic cell (DC) maturation in relation to atherosclerosis has not yet been clearly defined. Thus, we investigated whether quercetin can inhibit DC maturation and evaluated its potential value in atherosclerosis progression in ApoE(-/-) mice. Quercetin consumption inhibited DC activation, inflammatory response and suppressed the progression of atherosclerosis in ApoE(-/-) mice. Subsequently, quercetin treatment inhibited the phenotypic and functional maturation of DCs, as evidenced not only by downregulation of CD80, CD86, MHC-II, IL-6 and IL-12 but also by a reduction in the ability to stimulate T cell allogeneic proliferation. Finally, an in vitro study demonstrated that quercetin inhibited DC maturation via upregulation of Dabs, which then downregulated the Src/PI3K/Akt-NF-κB-inflammatory pathways. Our data indicate that quercetin attenuates atherosclerosis progression by regulating DC activation via Dab2 protein expression. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Sinomenine Protects against Lipopolysaccharide-Induced Acute Lung Injury in Mice via Adenosine A2A Receptor Signaling

    PubMed Central

    Li, Jun; Zhao, Li; He, Xie; Zeng, Yi-Jun; Dai, Shuang-Shuang

    2013-01-01

    Sinomenine (SIN) is a bioactive alkaloid extracted from the Chinese medicinal plant Sinomenium acutum, which is widely used in the clinical treatment of rheumatoid arthritis (RA). However, its role in acute lung injury (ALI) is unclear. In this study, we investigate the role of SIN in lipopolysaccharide (LPS)-induced ALI in mice. After ALI, lung water content and histological signs of pulmonary injury were attenuated, whereas the PaO2/FIO2 (P/F) ratios were elevated significantly in the mice pretreated with SIN. Additionally, SIN markedly inhibited inflammatory cytokine TNF-α and IL-1β expression levels as well as neutrophil infiltration in the lung tissues of the mice. Microarray analysis and real-time PCR showed that SIN treatment upregulated adenosine A2A receptor (A2AR) expression, and the protective effect of SIN was abolished in A2AR knockout mice. Further investigation in isolated mouse neutrophils confirmed the upregulation of A2AR by SIN and showed that A2AR-cAMP-PKA signaling was involved in the anti-inflammatory effect of SIN. Taken together, these findings demonstrate an A2AR-associated anti-inflammatory effect and the protective role of SIN in ALI, which suggests a potential novel approach to treat ALI. PMID:23555007

  5. Sinomenine protects against lipopolysaccharide-induced acute lung injury in mice via adenosine A(2A) receptor signaling.

    PubMed

    Li, Jun; Zhao, Li; He, Xie; Zeng, Yi-Jun; Dai, Shuang-Shuang

    2013-01-01

    Sinomenine (SIN) is a bioactive alkaloid extracted from the Chinese medicinal plant Sinomenium acutum, which is widely used in the clinical treatment of rheumatoid arthritis (RA). However, its role in acute lung injury (ALI) is unclear. In this study, we investigate the role of SIN in lipopolysaccharide (LPS)-induced ALI in mice. After ALI, lung water content and histological signs of pulmonary injury were attenuated, whereas the PaO2/FIO2 (P/F) ratios were elevated significantly in the mice pretreated with SIN. Additionally, SIN markedly inhibited inflammatory cytokine TNF-α and IL-1β expression levels as well as neutrophil infiltration in the lung tissues of the mice. Microarray analysis and real-time PCR showed that SIN treatment upregulated adenosine A(2A) receptor (A(2A)R) expression, and the protective effect of SIN was abolished in A(2A)R knockout mice. Further investigation in isolated mouse neutrophils confirmed the upregulation of A(2A)R by SIN and showed that A(2A)R-cAMP-PKA signaling was involved in the anti-inflammatory effect of SIN. Taken together, these findings demonstrate an A(2A)R-associated anti-inflammatory effect and the protective role of SIN in ALI, which suggests a potential novel approach to treat ALI.

  6. AIF inhibits tumor metastasis by protecting PTEN from oxidation

    PubMed Central

    Shen, Shao-Ming; Guo, Meng; Xiong, Zhong; Yu, Yun; Zhao, Xu-Yun; Zhang, Fei-Fei; Chen, Guo-Qiang

    2015-01-01

    Apoptosis-inducing factor (AIF) exerts dual roles on cell death and survival, but its substrates as a putative oxidoreductase and roles in tumorigenesis remain elusive. Here, we report that AIF physically interacts with and inhibits the oxidation of phosphatase and tensin homolog on chromosome ten (PTEN), a tumor suppressor susceptible for oxidation-mediated inactivation. More intriguingly, we also identify PTEN as a mitochondrial protein and the ectopic expression of mitochondrial targeting sequence-carrying PTEN almost completely inhibits Akt phosphorylation in PTEN-deficient cells. AIF knockdown causes oxidation-mediated inactivation of the lipid phosphatase activity of PTEN, with ensuing activation of Akt kinase, phosphorylation of the Akt substrate GSK-3β, and activation of β-catenin signaling in cancer cells. Through its effect on β-catenin signaling, AIF inhibits epithelial–mesenchymal transition (EMT) and metastasis of cancer cells in vitro and in orthotopically implanted xenografts. Accordingly, the expression of AIF is correlated with the survival of human patients with cancers of multiple origins. These results identify PTEN as the substrate of AIF oxidoreductase and reveal a novel function for AIF in controlling tumor metastasis. PMID:26415504

  7. Inhibition of retrograde transport protects mice from lethal ricin challenge.

    PubMed

    Stechmann, Bahne; Bai, Siau-Kun; Gobbo, Emilie; Lopez, Roman; Merer, Goulven; Pinchard, Suzy; Panigai, Laetitia; Tenza, Danièle; Raposo, Graça; Beaumelle, Bruno; Sauvaire, Didier; Gillet, Daniel; Johannes, Ludger; Barbier, Julien

    2010-04-16

    Bacterial Shiga-like toxins are virulence factors that constitute a significant public health threat worldwide, and the plant toxin ricin is a potential bioterror weapon. To gain access to their cytosolic target, ribosomal RNA, these toxins follow the retrograde transport route from the plasma membrane to the endoplasmic reticulum, via endosomes and the Golgi apparatus. Here, we used high-throughput screening to identify small molecule inhibitors that protect cells from ricin and Shiga-like toxins. We identified two compounds that selectively block retrograde toxin trafficking at the early endosome-TGN interface, without affecting compartment morphology, endogenous retrograde cargos, or other trafficking steps, demonstrating an unexpected degree of selectivity and lack of toxicity. In mice, one compound clearly protects from lethal nasal exposure to ricin. Our work discovers the first small molecule that shows efficacy against ricin in animal experiments and identifies the retrograde route as a potential therapeutic target.

  8. Inhibition of vacuolar adenosine triphosphatase antagonizes the effects of clostridial neurotoxins but not phospholipase A2 neurotoxins.

    PubMed

    Simpson, L L; Coffield, J A; Bakry, N

    1994-04-01

    Bafilomycin A1, an inhibitor of vacuolar adenosine triphosphatase, was tested for its ability to antagonize botulinum neurotoxins (serotypes A-G), tetanus toxin and phospholipase A2 neurotoxins (notexin, beta-bungarotoxin, taipoxin and textilotoxin) on the mouse phrenic nerve-hemidiaphragm preparation. Bafilomycin itself produced concentration-dependent blockade of neuromuscular transmission without blocking nerve action potentials or muscle action potentials. This effect may have been due to inhibition of the proton pump that regulates acetylcholine transport into vesicles. At submaximal concentrations, bafilomycin was very effective in delaying the onset of paralysis due to all clostridial neurotoxins, but it had no protective effect against phospholipase A2 neurotoxins. Experiments were done to determine which of the three steps in clostridial neurotoxin action was antagonized by bafilomycin (e.g., binding, internalization and intracellular poisoning). Both pharmacological experiments and ligand-binding experiments showed that the drug did not block toxin binding to the plasma membrane. Similarly, pharmacological experiments on the time-dependent effects of bafilomycin showed that the drug did not antagonize the intracellular actions of toxins. The data indicated that bafilomycin acted at the intermediate step of internalization. This is in keeping with the facts that: 1) bafilomycin inhibits vacuolar adenosine triphosphatase, which in turn leads to inhibition of acidification in endosomes and 2) clostridial neurotoxins depend upon acidification of endosomes for translocation to the cytosol. The finding that bafilomycin antagonizes tetanus toxin may provide important clues for understanding how this toxin can act locally to produce flaccid paralysis. The finding that bafilomycin is a universal antagonist that protects against all clostridial neurotoxins may have important implications for developing therapeutic drugs.

  9. Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E

    PubMed Central

    Saadat, Khandakar A.S.M.; Murakami, Yusuke; Tan, Xue; Nomura, Yoko; Yasukawa, Tsutomu; Okada, Eiichi; Ikeda, Yasuhiro; Yanagi, Yasuo

    2014-01-01

    In this study, we show augmented autophagy in the retinal pigment epithelial cell line ARPE-19 when cultured in the presence of the lipofuscin pigment A2E. A2E alone does not induce RPE cell death, but cell death was induced in the presence of A2E with the autophagy inhibitor 3-methyladenine (3MA), with a concomitant increase in the generation of mitochondrial reactive oxygen species. On the other hand, the ATP production capacity of mitochondria was decreased in the presence of A2E, and pharmacological inhibition of autophagy had no additional effects. The altered mRNA expression level of mitochondrial function markers was confirmed by real-time polymerase chain reaction, which showed that the antioxidant enzymes SOD1 and SOD2 were not reduced in the presence of A2E alone, but significantly suppressed with the addition of 3MA. Furthermore, transmission electron micrography revealed autophagic vacuole formation in the presence of A2E, and inhibition of autophagy resulted in the accumulation of abnormal mitochondria with loss of cristae. Spheroid culture of human RPE cells demonstrated debris accumulation in the presence of A2E, and this accumulation was accelerated in the presence of 3MA. These results indicate that autophagy in RPE cells is a vital cytoprotective process that prevents the accumulation of damaged cellular molecules. PMID:25473597

  10. Angiopoietin1 Inhibits Mast Cell Activation and Protects against Anaphylaxis

    PubMed Central

    Li, Meng-Tao; Liu, Yi-Nan; He, Qi-Hua; Xiao, Jun-Jun; Bai, Yun

    2014-01-01

    Since morbidity and mortality rates of anaphylaxis diseases have been increasing year by year, how to prevent and manage these diseases effectively has become an important issue. Mast cells play a central regulatory role in allergic diseases. Angiopoietin1 (Ang-1) exhibits anti-inflammatory properties by inhibiting vascular permeability, leukocyte migration and cytokine production. However, Ang-1's function in mast cell activation and anaphylaxis diseases is unknown. The results of our study suggest that Ang-1 decreased lipopolysaccharide (LPS)-induced pro-inflammatory cytokines production of mast cells by suppressing IκB phosphorylation and NF-κB nuclear translocation. Ang-1 also strongly inhibited compound 48/80 induced and FcεRI-mediated mast cells degranulation by decreasing intracellular calcium levels in vitro. In vivo lentivirus-mediated delivery of Ang-1 in mice exhibited alleviated leakage in IgE-dependent passive cutaneous anaphylaxis (PCA). Furthermore, exogenous Ang-1 intervention treatment prevented mice from compound 48/80-induced mesentery mast cell degranulation, attenuated increases in pro-inflammatory cytokines, relieved lung injury, and improved survival in anaphylaxis shock. The results of our study reveal, for the first time, the important role of Ang-1 in the activation of mast cells, and identify a therapeutic effect of Ang-1 on anaphylaxis diseases. PMID:24586553

  11. Involvement of the Leishmania donovani virulence factor A2 in protection against heat and oxidative stress.

    PubMed

    McCall, Laura-Isobel; Matlashewski, Greg

    2012-10-01

    Leishmania is an obligate intracellular protozoan parasite that infects cells of the reticulo-endothelial system. Host defences against Leishmania include fever and oxidant production, and the parasite has developed a number of defence mechanisms to neutralize the host response. The Leishmania donovani A2 family of proteins has been shown to be essential for survival in mammalian visceral organs. Here we provide evidence that A2 proteins protect the parasite against host defences, namely heat stress (fever) and oxidative stress. A2 is however unable to protect the cells from endoplasmic reticulum stress induced by dithiothreitol. To downregulate A2 protein expression, L. donovani was transfected with an A2 antisense RNA expressing-vector, resulting in significant reduction of A2 levels. The resulting A2-deficient cells were more sensitive to heat shock and this was associated with increased production of internal oxidants during heat shock. Moreover, axenic amastigotes with downregulated A2 expression had increased internal oxidants and decreased viability following treatment with hydrogen peroxide or a nitric oxide donor when compared to control cells. Overall, these results suggest that A2 protects L. donovani from a variety of stresses, thereby allowing it to survive in the internal organs of the mammalian host and to cause visceral disease.

  12. Protective role of p21(Waf1/Cip1) against prostaglandin A2-mediated apoptosis of human colorectal carcinoma cells.

    PubMed Central

    Gorospe, M; Wang, X; Guyton, K Z; Holbrook, N J

    1996-01-01

    Prostaglandin A2 (PGA2) suppresses tumor growth in vivo, is potently antiproliferative in vitro, and is a model drug for the study of the mammalian stress response. Our previous studies using breast carcinoma MCF-7 cells suggested that p21(Waf1/Cip1) induction enabled cells to survive PGA2 exposure. Indeed, the marked sensitivity of human colorectal carcinoma RKO cells to the cytotoxicity of PGA2 is known to be associated with a lack of a PGA2-mediated increase in p21(Waf1/Cip1) expression, inhibition of cyclin-dependent kinase activity, and growth arrest. To determine if cell death following exposure to PGA2 could be prevented by forcing the expression of p21(Waf1/Cip1) in RKO cells, we utilized an adenoviral vector-based expression system. We demonstrate that ectopic expression of p21(Waf1/Cip1) largely rescued RKO cells from PGA2-induced apoptotic cell death, directly implicating p21(Waf1/Cip1) as a determinant of the cellular outcome (survival versus death) following exposure to PGA2. To discern whether p21(Waf1/Cip1)-mediated protection operates through the implementation of cellular growth arrest, other growth-inhibitory treatments were studied for the ability to attenuate PGA2-induced cell death. Neither serum depletion nor suramin (a growth factor receptor antagonist) protected RKO cells against PGA2 cytotoxicity, and neither induced p21(Waf1/Cip1) expression. Mimosine, however, enhanced p21(Waf1/Cip1) expression, completely inhibited RKO cell proliferation, and exerted marked protection against a subsequent PGA2 challenge. Taken together, our results directly demonstrate a protective role for p21(Waf1/Cip1) during PGA2 cellular stress and provide strong evidence that the implementation of cellular growth arrest contributes to this protective influence. PMID:8943319

  13. Inhibiting an epoxide hydrolase virulence strategy protects CFTR**

    PubMed Central

    Bahl, Christopher D.; Hvorecny, Kelli L.; Bomberger, Jennifer M.; Stanton, Bruce A.; Hammock, Bruce D.; Morisseau, Christophe; Madden, Dean R.

    2015-01-01

    Opportunistic pathogens exploit diverse strategies to sabotage host defenses. Pseudomonas aeruginosa secretes the CFTR inhibitory factor Cif and thus triggers loss of CFTR, an ion channel required for airway mucociliary defense. However, Cif's mechanism of action has remained unclear. It catalyzes epoxide hydrolysis, but there is no known role for natural epoxides in CFTR regulation. Here, we show that Cif's hydrolase activity is strictly required for its effects on CFTR. We also uncover a small-molecule inhibitor that protects this key component of the mucociliary defense system. Our results provide a basis for targeting Cif's distinctive virulence chemistry and suggest an unanticipated role of physiological epoxides in intracellular protein trafficking. PMID:26136396

  14. Gabexate mesilate (FOY) inhibition of amylase and phospholipase A(2) activity in sow pancreatic juice.

    PubMed

    Caronna, Roberto; Loretta, Diana; Campedelli, Paolo; Catinelli, Stefania; Nofroni, Italo; Sibio, Simone; Sinibaldi, Giovanni; Chirletti, Piero

    2003-01-01

    We designed this study in sows to investigate the enzyme inhibitory action of gabexate mesylate (GM) directly in the pancreatic juice. We studied 16 sows, each weighing about 130 kg. The pancreatic duct was identified and cannulated to collect the pancreatic juice. Sows in the treated group received intravenous GM infusion at a dose of 1000 mg over 24 h. Control sows underwent the same sampling schedule while receiving physiological solution. GM inhibited the two pancreatic enzymes amylase and phospholipase A(2) (PA(2)) in pancreatic juice. Thus, the enzyme inhibition in the pancreatic gland itself and the central role of (PA(2)) inhibition in enzyme cascade responsible for activating other proteases confirm the therapeutic use of GM in acute pancreatitis.

  15. PI3Kγ Inhibition Protects Against Diabetic Cardiomyopathy in Mice.

    PubMed

    Maffei, Angelo; Cifelli, Giuseppe; Carnevale, Raimondo; Iacobucci, Roberta; Pallante, Fabio; Fardella, Valentina; Fardella, Stefania; Hirsch, Emilio; Lembo, Giuseppe; Carnevale, Daniela

    2017-01-01

    Cardiovascular diseases, including cardiomyopathy, are the major complications in diabetes. A deeper understanding of the molecular mechanisms leading to cardiomyopathy is critical for developing novel therapies. We proposed phosphoinositide3-kinase gamma (PI3Kγ) as a molecular target against diabetic cardiomyopathy, given the role of PI3Kγ in cardiac remodeling to pressure overload. Given the availability of a pharmacological inhibitor of this molecular target GE21, we tested the validity of our hypothesis by inducing diabetes in mice with genetic ablation of PI3Kγ or knock-in for a catalytically inactive PI3Kγ. Mice were made diabetic by streptozotocin. Cardiac function was assessed by serial echocardiographic analyses, while fibrosis and inflammation were evaluated by histological analysis. Diabetes induced cardiac dysfunction in wild-type mice. Systolic dysfunction was completely prevented, and diastolic dysfunction was partially blocked, in both PI3Kγ knock-out and kinase-dead mice. Cardiac dysfunction was similarly rescued by administration of the PI3Kγ inhibitor GE21 in a dose-dependent manner. These actions of genetic and pharmacological PI3Kγ inhibition were associated with a decrease in inflammation and fibrosis in diabetic hearts. Our study demonstrates a fundamental role of PI3Kγ in diabetic cardiomyopathy in mice and the beneficial effect of pharmacological PI3Kγ inhibition, highlighting its potential as a promising strategy for clinical treatment of cardiac complications of diabetic patients. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  16. Inhibition of human factor VIIIa by anti-A2 subunit antibodies.

    PubMed Central

    Lollar, P; Parker, E T; Curtis, J E; Helgerson, S L; Hoyer, L W; Scott, M E; Scandella, D

    1994-01-01

    Human inhibitory alloantibodies and autoantibodies to Factor VIII (FVIII) are usually directed toward the A2 and/or C2 domains of the FVIII molecule. Anti-C2 antibodies block the binding of FVIII to phospholipid, but the mechanism of action of anti-A2 antibodies is not known. We investigated the properties of a patient autoantibody, RC, and a monoclonal antibody, 413, that bind to the region which contains the epitopes of all anti-A2 alloantibodies or autoantibodies studied to date. mAb 413 and RC were noncompetitive inhibitors of a model intrinsic Factor X activation complex (intrinsic FXase) consisting of Factor IXa, activated FVIII (FVIIIa), and synthetic phospholipid vesicles, since they decreased the Vmax of intrinsic FXase by > 95% at saturating concentrations without altering the Km. This indicates that RC and mAb 413 either block the binding of FVIIIa to FIXa or phospholipid or interfere with the catalytic function of fully assembled intrinsic FXase, but they do not inhibit the binding of the substrate Factor X. mAb 413 did not inhibit the increase in fluorescence anisotropy that results from the binding of Factor VIIIa to fluorescein-5-maleimidyl-D-phenylalanyl-prolyl-arginyl-FIXa (Fl-M-FPR-FIXa) on phospholipid vesicles in the absence of Factor X, indicating it does not inhibit assembly of intrinsic FXase. Addition of Factor X to Fl-M-FPR-FIXa, FVIIIa, and phospholipid vesicles produced a further increase in fluorescence anisotropy and a decrease in fluorescence intensity. This effect was blocked completely by mAb 413. We conclude that anti-A2 antibodies inhibit FVIIIa function by blocking the conversion of intrinsic FXase/FX complex to the transition state, rather than by interfering with formation of the ground state Michaelis complex. PMID:8200986

  17. Ketamine Protects Gamma Oscillations by Inhibiting Hippocampal LTD

    PubMed Central

    Huang, Lanting; Yang, Xiu-Juan; Huang, Ying; Sun, Eve Y.

    2016-01-01

    NMDA receptors have been widely reported to be involved in the regulation of synaptic plasticity through effects on long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD have been implicated in learning and memory processes. Besides synaptic plasticity, it is known that the phenomenon of gamma oscillations is critical in cognitive functions. Synaptic plasticity has been widely studied, however it is still not clear, to what degree synaptic plasticity regulates the oscillations of neuronal networks. Two NMDA receptor antagonists, ketamine and memantine, have been shown to regulate LTP and LTD, to promote cognitive functions, and have even been reported to bring therapeutic effects in major depression and Alzheimer’s disease respectively. These compounds allow us to investigate the putative interrelationship between network oscillations and synaptic plasticity and to learn more about the mechanisms of their therapeutic effects. In the present study, we have identified that ketamine and memantine could inhibit LTD, without impairing LTP in the CA1 region of mouse hippocampus, which may underlie the mechanism of these drugs’ therapeutic effects. Our results suggest that NMDA-induced LTD caused a marked loss in the gamma power, and pretreatment with 10 μM ketamine prevented the oscillatory loss via its inhibitory effect on LTD. Our study provides a new understanding of the role of NMDA receptors on hippocampal plasticity and oscillations. PMID:27467732

  18. Growth inhibition and microcystin degradation effects of Acinetobacter guillouiae A2 on Microcystis aeruginosa.

    PubMed

    Yi, Yang-Lei; Yu, Xiao-Bo; Zhang, Chao; Wang, Gao-Xue

    2015-01-01

    Strain A2 with algicidal activity against Microcystis aeruginosa was isolated and identified with the genus Acinetobacter on the basis of phenotypic tests and 16S rRNA gene analysis. It was identified with the species Acinetobactor guillouiae by partial rpoB sequence analysis. When 10% (v/v) of the bacterial culture was co-incubated with M. aeruginosa culture, algicidal efficiency reached 91.6% after 7 days. Supernatant of A2 culture showed similar algicidal activity, while the cell pellet had little activity, suggesting that Acinetobacter guillouiae A2 indirectly attacked M. aeruginosa cells by secreting an extracellular algicidal compound, which was characterized as heat-stable. A significant decrease in the microcystin (microcystin-LR) concentration was observed after 10% (v/v) addition of A2 culture. Transcription of three microcystin-related genes (mcyA, mcyD and mcyH) was also found to be inhibited. The algicidal compound 4-hydroxyphenethylamine was obtained by further isolation and purification using various chromatographic techniques. The EC50, 3d and EC50, 7d values of 4-hydroxyphenethylamine against M. aeruginosa were 22.5 and 10.3 mgL(-1), respectively. These results indicate that A. guillouiae strain A2 inhibits growth of M. aeruginosa and degrades microcystin production. The identified compound, 4-hydroxyphenethylamine, has potential for development as a new algicidal formulation or product.

  19. Suppressing effect of C a2 + blips on puff amplitudes by inhibiting channels to prevent recovery

    NASA Astrophysics Data System (ADS)

    Chen, Yuan; Qi, Hong; Li, Xiang; Cai, Meichun; Chen, Xingqiang; Liu, Wen; Shuai, Jianwei

    2016-08-01

    As local signals, calcium puffs arise from the concerted opening of a few nearby inositol 1,4,5-trisphospate receptor channels to release C a2 + ions from the endoplasmic reticulum. Although C a2 + puffs have been well studied, little is known about the modulation of cytosolic basal C a2 + concentration ([Ca2 +] Basal) on puff dynamics. In this paper we consider a puff model to study how the statistical properties of puffs are modulated by [Ca2 +] Basal. The puff frequency and lifetime trivially increase with the increasing [Ca2 +] Basal, but an unexpected result is that the puff amplitude and the maximum open-channel number of the puff show decreasing relationship with the increasing [Ca2 +] Basal. The underlying dynamics is related not only to the increasing puff frequency which gives a shorter recovery time, but also to the increasing frequency of blips with only one channel open. We indicate that C a2 + blips cause the channels to be inhibited and prevent their recovery during interpuff intervals, resulting in the suppressing effect on puff amplitudes. With increasing [Ca2 +] Basal, more blips occur to cause more channels to be inhibited, leaving fewer channels available for puff events. This study shows that the blips may play relevant functions in global C a2 + waves through modulating puff dynamics.

  20. Pharmacological inhibition of galectin-3 protects against hypertensive nephropathy.

    PubMed

    Frenay, Anne-Roos S; Yu, Lili; van der Velde, A Rogier; Vreeswijk-Baudoin, Inge; López-Andrés, Natalia; van Goor, Harry; Silljé, Herman H; Ruifrok, Willem P; de Boer, Rudolf A

    2015-03-01

    Galectin-3 activation is involved in the pathogenesis of renal damage and fibrogenesis. Limited data are available to suggest that galectin-3-targeted intervention is a potential therapeutic candidate for the prevention of chronic kidney disease. Homozygous TGR(mREN)27 (REN2) rats develop severe high blood pressure (BP) and hypertensive end-organ damage, including nephropathy and heart failure. Male REN2 rats were treated with N-acetyllactosamine [galectin-3 inhibitor (Gal3i)] for 6 wk; untreated REN2 and Sprague-Dawley rats served as controls. We measured cardiac function with echocardiogram and invasive hemodynamics before termination. BP and proteinuria were measured at baseline and at 3 and 6 wk. Plasma creatinine was determined at 6 wk. Renal damage was assessed for focal glomerular sclerosis, glomerular desmin expression, glomerular and interstitial macrophages, kidney injury molecule-1 expression, and α-smooth muscle actin expression. Inflammatory cytokines and extracellular matrix proteinases were quantified by quantitative real-time PCR. Systolic BP was higher in control REN2 rats, with no effect of Gal3i treatment. Plasma creatinine and proteinuria were significantly increased in control REN2 rats; Gal3i treatment reduced both. Renal damage (focal glomerular sclerosis, desmin, interstitial macrophages, kidney injury molecule-1, α-smooth muscle actin, collagen type I, and collagen type III) was also improved by Gal3i. All inflammatory markers (CD68, IL-68, galectin-3, and monocyte chemoattractant protein-1) were elevated in control REN2 rats and attenuated by Gal3i. Markers of extracellular matrix turnover were marginally altered in untreated REN2 rats compared with Sprague-Dawley rats. In conclusion, galectin-3 inhibition attenuated hypertensive nephropathy, as indicated by reduced proteinuria, improved renal function, and decreased renal damage. Drugs binding to galectin-3 may be therapeutic candidates for the prevention of chronic kidney disease.

  1. Acetaminophen inhibits neuronal inflammation and protects neurons from oxidative stress

    PubMed Central

    Tripathy, Debjani; Grammas, Paula

    2009-01-01

    Background Recent studies have demonstrated a link between the inflammatory response, increased cytokine formation, and neurodegeneration in the brain. The beneficial effects of anti-inflammatory drugs in neurodegenerative diseases, such as Alzheimer's disease (AD), have been documented. Increasing evidence suggests that acetaminophen has unappreciated anti-oxidant and anti-inflammatory properties. The objectives of this study are to determine the effects of acetaminophen on cultured brain neuronal survival and inflammatory factor expression when exposed to oxidative stress. Methods Cerebral cortical cultured neurons are pretreated with acetaminophen and then exposed to the superoxide-generating compound menadione (5 μM). Cell survival is assessed by MTT assay and inflammatory protein (tumor necrosis factor alpha, interleukin-1, macrophage inflammatory protein alpha, and RANTES) release quantitated by ELISA. Expression of pro- and anti-apoptotic proteins is assessed by western blots. Results Acetaminophen has pro-survival effects on neurons in culture. Menadione, a superoxide releasing oxidant stressor, causes a significant (p < 0.001) increase in neuronal cell death as well as in the release of tumor necrosis factor alpha, interleukin-1, macrophage inflammatory protein alpha, and RANTES from cultured neurons. Pretreatment of neuronal cultures with acetaminophen (50 μM) increases neuronal cell survival and inhibits the expression of these cytokines and chemokines. In addition, we document, for the first time, that acetaminophen increases expression of the anti-apoptotic protein Bcl2 in brain neurons and decreases the menadione-induced elevation of the proapoptotic protein, cleaved caspase 3. We show that blocking acetaminophen-induced expression of Bcl2 reduces the pro-survival effect of the drug. Conclusion These data show that acetaminophen has anti-oxidant and anti-inflammatory effects on neurons and suggest a heretofore unappreciated therapeutic potential for

  2. Homocysteine inhibits neoangiogenesis in mice through blockade of annexin A2–dependent fibrinolysis

    PubMed Central

    Jacovina, Andrew T.; Deora, Arunkumar B.; Ling, Qi; Broekman, M. Johan; Almeida, Dena; Greenberg, Caroline B.; Marcus, Aaron J.; Smith, Jonathan D.; Hajjar, Katherine A.

    2009-01-01

    When plasma levels of homocysteine (HC), a thiol amino acid formed upon methionine demethylation, exceed 12 μM, individuals are at increased risk of developing large vessel atherothrombosis and small vessel dysfunction. The annexin A2 complex (termed “A2”) is the cell surface coreceptor for plasminogen and TPA and accelerates the catalytic activation of plasmin, the major fibrinolytic agent in mammals. We previously showed that HC prevents A2-mediated, TPA-dependent activation of plasminogen in vitro by disulfide derivatization of the “tail” domain of A2. We also demonstrated that fibrinolysis and angiogenesis are severely impaired in A2-deficient mice. We now report here that, although hyperhomocysteinemic mice had a normal coagulation profile and normal platelet function, fibrin accumulated in their tissues due to reduced perivascular fibrinolytic activity and angiogenesis was impaired. A2 isolated from hyperhomocysteinemic mice failed to fully support TPA-dependent plasmin activation. However, infusion of hyperhomocysteinemic mice with fresh recombinant A2, which localized to neoangiogenic endothelial cells, resulted in normalization of angiogenesis and disappearance of peri- and intravascular fibrin. We therefore conclude that hyperhomocysteinemia impairs postnatal angiogenesis by derivatizing A2, preventing perivascular fibrinolysis, and inhibiting directed endothelial cell migration. These findings provide a mechanistic explanation for microvascular dysfunction and macrovascular occlusion in individuals with hyperhomocysteinemia. PMID:19841537

  3. The SAM domain inhibits EphA2 interactions in the plasma membrane.

    PubMed

    Singh, Deo R; Ahmed, Fozia; Paul, Michael D; Gedam, Manasee; Pasquale, Elena B; Hristova, Kalina

    2017-01-01

    All members of the Eph receptor family of tyrosine kinases contain a SAM domain near the C terminus, which has been proposed to play a role in receptor homotypic interactions and/or interactions with binding partners. The SAM domain of EphA2 is known to be important for receptor function, but its contribution to EphA2 lateral interactions in the plasma membrane has not been determined. Here we use a FRET-based approach to directly measure the effect of the SAM domain on the stability of EphA2 dimers on the cell surface in the absence of ligand binding. We also investigate the functional consequences of EphA2 SAM domain deletion. Surprisingly, we find that the EphA2 SAM domain inhibits receptor dimerization and decreases EphA2 tyrosine phosphorylation. This role is dramatically different from the role of the SAM domain of the related EphA3 receptor, which we previously found to stabilize EphA3 dimers and increase EphA3 tyrosine phosphorylation in cells in the absence of ligand. Thus, the EphA2 SAM domain likely contributes to a unique mode of EphA2 interaction that leads to distinct signaling outputs. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. The inhibition and protection of cholinesterase by physostigmine and pyridostigmine against Soman poisoning in vivo.

    PubMed

    Xia, D Y; Wang, L X; Pei, S Q

    1981-01-01

    It has been shown that some reversible cholinesterase (ChE) inhibitors as physostigmine and pyridostigmine are prophylactically effective in organophosphate poisoning. The inhibition and protection of ChE against Soman poisoning with the above mentioned drugs was investigated in mice. (1) Physostigmine and pyridostigmine significantly inhibited the ChE in whole blood in vivo and their inhibitory potencies with equitoxic doses were approximately equal (1/5LD50 about 30%; 1/2 LD50 about 45% respectively). Physostigmine also significantly inhibited brain ChE and its potency was slightly weaker than that in blood; but pyridostigmine only slightly inhibited brain ChE (17%) with large dose (1/2 LD50). The extent of inhibition was in parallel with the dosage of the drugs used. (2) Physostigmine had definite protection in the blood and brain ChE against Soman poisoning. The extent of protection was in parallel with the dosage used. The protection of blood ChE by pyridostigmine was weaker than that by physostigmine. There was no protection of brain ChE by pyridostigmine. (3) The inhibitory potency of equitoxic doses of physostigmine and pyridostigmine in the ChE of diaphragm muscle was equal too (1/2 LD50 about 45%), and the protective effect of physostigmine was still greater than that of pyridostigmine in Soman poisoning. (4) The time course of blood ChE inhibition by physostigmine in vivo was of short duration. While 30 minutes after administration of physostigmine, the ChE activity gradually recovered and it returned to normal level after 4 hours. The blood ChE inhibition by pyridostigmine reached a peak level after 2 hours, and the ChE activity slowly increased after 4 hours, but there was 30% of ChE activity still inhibited after 8 hours. Physostigmine and pyridostigmine, the reversible ChE inhibitors with carbamate structure, have definite ChE protection against Soman poisoning. The prophylactic efficacy was obviously correlated with their ChE protective potency

  5. EGLN1 Inhibition and Rerouting of α-Ketoglutarate Suffice for Remote Ischemic Protection.

    PubMed

    Olenchock, Benjamin A; Moslehi, Javid; Baik, Alan H; Davidson, Shawn M; Williams, Jeremy; Gibson, William J; Chakraborty, Abhishek A; Pierce, Kerry A; Miller, Christine M; Hanse, Eric A; Kelekar, Ameeta; Sullivan, Lucas B; Wagers, Amy J; Clish, Clary B; Vander Heiden, Matthew G; Kaelin, William G

    2016-02-25

    Ischemic preconditioning is the phenomenon whereby brief periods of sublethal ischemia protect against a subsequent, more prolonged, ischemic insult. In remote ischemic preconditioning (RIPC), ischemia to one organ protects others organs at a distance. We created mouse models to ask if inhibition of the alpha-ketoglutarate (αKG)-dependent dioxygenase Egln1, which senses oxygen and regulates the hypoxia-inducible factor (HIF) transcription factor, could suffice to mediate local and remote ischemic preconditioning. Using somatic gene deletion and a pharmacological inhibitor, we found that inhibiting Egln1 systemically or in skeletal muscles protects mice against myocardial ischemia-reperfusion (I/R) injury. Parabiosis experiments confirmed that RIPC in this latter model was mediated by a secreted factor. Egln1 loss causes accumulation of circulating αKG, which drives hepatic production and secretion of kynurenic acid (KYNA) that is necessary and sufficient to mediate cardiac ischemic protection in this setting.

  6. Inhibition of light emission in a 2.5D photonic structure

    SciTech Connect

    Peretti, Romain; Seassal, Christian; Viktorovich, Pierre; Letartre, Xavier

    2014-07-14

    We analyse inhibition of emission in a 2.5D photonic structures made up of a photonic crystal (PhC) and Bragg mirrors using Finite Differences Time Domaine (FDTD) simulations. A comparison is made between an isolated PhC membrane and the same PhC suspended onto a Bragg mirror or sandwiched between 2 Bragg mirrors. Strong inhibition of the Purcell factor is observed in a broad spectral range, whatever the in-plane orientation and location of the emitting dipole. We analysed these results numerically and theoretically by simulating the experimentally observed lifetime of a collection of randomly distributed emitters, showing that their average emission rate is decreased by more than one decade, both for coupled or isolated emitters.

  7. The bacterium Xenorhabdus nematophila inhibits phospholipases A2 from insect, prokaryote, and vertebrate sources

    NASA Astrophysics Data System (ADS)

    Park, Youngjin; Kim, Yonggyun; Stanley, David

    The bacterium, Xenorhabdus nematophila, is a virulent insect pathogen. Part of its pathogenicity is due to impairing cellular immunity by blocking biosynthesis of eicosanoids, the major recognized signal transduction system in insect cellular immunity. X. nematophila inhibits the first step in eicosanoid biosynthesis, phospholipase A2 (PLA2). Here we report that the bacterium inhibits PLA2 from two insect immune tissues, hemocytes and fat body, as well as PLA2s selected to represent a wide range of organisms, including prokaryotes, insects, reptiles, and mammals. Our finding on a bacterial inhibitor of PLA2 activity contributes new insight into the chemical ecology of microbe-host interactions, which usually involve actions rather than inhibitors of PLA2s.

  8. Calcitonin gene-related peptide inhibits local acute inflammation and protects mice against lethal endotoxemia.

    PubMed

    Gomes, Rachel Novaes; Castro-Faria-Neto, Hugo C; Bozza, Patricia T; Soares, Milena B P; Shoemaker, Charles B; David, John R; Bozza, Marcelo T

    2005-12-01

    Calcitonin gene-related peptide (CGRP), a potent vasodilatory peptide present in central and peripheral neurons, is released at inflammatory sites and inhibits several macrophage, dendritic cell, and lymphocyte functions. In the present study, we investigated the role of CGRP in models of local and systemic acute inflammation and on macrophage activation induced by lipopolysaccharide (LPS). Intraperitoneal pretreatment with synthetic CGRP reduces in approximately 50% the number of neutrophils in the blood and into the peritoneal cavity 4 h after LPS injection. CGRP failed to inhibit neutrophil recruitment induced by the direct chemoattractant platelet-activating factor, whereas it significantly inhibited LPS-induced KC generation, suggesting that the effect of CGRP on neutrophil recruitment is indirect, acting on chemokine production by resident cells. Pretreatment of mice with 1 mug of CGRP protects against a lethal dose of LPS. The CGRP-induced protection is receptor mediated because it is completely reverted by the CGRP receptor antagonist, CGRP 8-37. The protective effect of CGRP correlates with an inhibition of TNF-alpha and an induction of IL-6 and IL-10 in mice sera 90 min after LPS challenge. Finally, CGRP significantly inhibits LPS-induced TNF-alpha released from mouse peritoneal macrophages. These results suggest that activation of the CGRP receptor on macrophages during acute inflammation could be part of the negative feedback mechanism controlling the extension of acute inflammatory responses.

  9. Protection against chemical-induced lung injury by inhibition of pulmonary cytochrome P-450

    SciTech Connect

    Verschoyle, R.D.; Dinsdale, D. )

    1990-04-01

    Protection afforded by trialkyl phosphorothionates against the lung injury caused by trialkyl phosphorothiolates probably results from the inhibition by the P{double bond}S moiety of the thionates, of one or more pulmonary cytochrome P-450 isozymes. The aromatic hydrocarbons p-xylene and pseudocumene also protect against this injury and inhibit some P-450 isozymes, but by a different mechanism. OOS-Trimethylphosphorothionate and p-xylene were compared as protective agents against the effect of OOS-trimethylphosphorothiolate and two other lung toxins ipomeanol and 1-nitronaphthalene that are known to be activated by cytochrome P-450. The effects of these protective compounds, in vivo, on pulmonary cytochrome P-450 activity were also determined. Both compounds inhibited pentoxyresorufin O-deethylase activity, but not ethoxyresorufin O-deethylase. The phosphorothionate was most effective against lung injury caused by the phosphorothiolates and 1-nitronaphthalene, whereas p-xylene was much more effective against ipomeanol. {beta}-Naphthoflavone, which induces pulmonary ethoxyresorufin O-deethylase activity, did not protect against phosphorothiolate or 1-nitronaphthalene injury, and it was only marginally effective in decreasing the toxicity or ipomeanol.

  10. Protection from heat-induced protein migration and DNA repair inhibition by cycloheximide.

    PubMed

    Armour, E P; Lee, Y J; Corry, P M; Borrelli, M J

    1988-12-15

    The mechanism by which Cycloheximide (CHM) protects cells from heat induced killing has been investigated. Cycloheximide (10 micrograms/ml) added for 2 hr before and during a 3 hour heating at 43 degrees C prevented a 40% increase of heat-induced protein accumulation in the nucleus and protected cells (0.0001 vs. 0.15 surviving fraction) from heat-induced killing. Heat-induced DNA repair inhibition was also suppressed when cells were treated with CHM in the above manner. This combination of results suggests that protein accumulation in the nucleus and inhibition of DNA repair are related and these events are associated with CHM protection from heat induced cell killing.

  11. Resveratrol inhibits estrogen-induced breast carcinogenesis through induction of NRF2-mediated protective pathways

    PubMed Central

    Singh, Bhupendra; Shoulson, Rivka; Chatterjee, Anwesha; Ronghe, Amruta; Bhat, Nimee K.; Dim, Daniel C.; Bhat, Hari K.

    2014-01-01

    The importance of estrogens in the etiology of breast cancer is widely recognized. Estrogen-induced oxidative stress has been implicated in this carcinogenic process. Resveratrol (Res), a natural antioxidant phytoestrogen has chemopreventive effects against a variety of illnesses including cancer. The objective of the present study was to characterize the mechanism(s) of Res-mediated protection against estrogen-induced breast carcinogenesis. Female August Copenhagen Irish rats were treated with 17β-estradiol (E2), Res and Res + E2 for 8 months. Cotreatment of rats with Res and E2 inhibited E2-mediated proliferative changes in mammary tissues and significantly increased tumor latency and reduced E2-induced breast tumor development. Resveratrol treatment alone or in combination with E2 significantly upregulated expression of nuclear factor erythroid 2-related factor 2 (NRF2) in mammary tissues. Expression of NRF2-regulated antioxidant genes NQO1, SOD3 and OGG1 that are involved in protection against oxidative DNA damage was increased in Res- and Res + E2-treated mammary tissues. Resveratrol also prevented E2-mediated inhibition of detoxification genes AOX1 and FMO1. Inhibition of E2-mediated alterations in NRF2 promoter methylation and expression of NRF2 targeting miR-93 after Res treatment indicated Res-mediated epigenetic regulation of NRF2 during E2-induced breast carcinogenesis. Resveratrol treatment also induced apoptosis and inhibited E2-mediated increase in DNA damage in mammary tissues. Increased apoptosis and decreased DNA damage, cell migration, colony and mammosphere formation in Res- and Res + E2-treated MCF-10A cells suggested a protective role of Res against E2-induced mammary carcinogenesis. Small-interfering RNA-mediated silencing of NRF2 inhibited Res-mediated preventive effects on the colony and mammosphere formation. Taken together, these results suggest that Res inhibits E2-induced breast carcinogenesis via induction of NRF2-mediated protective

  12. Activation of Adenosine A2A Receptors Inhibits Neutrophil Transuroepithelial Migration ▿

    PubMed Central

    Säve, Susanne; Mohlin, Camilla; Vumma, Ravi; Persson, Katarina

    2011-01-01

    Adenosine has been identified as a significant inhibitor of inflammation by acting on adenosine A2A receptors. In this study, we examined the role of adenosine and A2A receptors in the transmigration of human neutrophils across an in vitro model of the transitional bladder urothelium. Human uroepithelial cells (UROtsa) were grown on transwell inserts; uropathogenic Escherichia coli (UPEC) and neutrophils were added to the transwell system; and the number of migrating neutrophils was evaluated. Reverse transcription-PCR (RT-PCR), immunohistochemistry, and flow cytometry were used to investigate the expression of adenosine receptors, the epithelial adhesion molecule ICAM-1, and the neutrophil integrin CD11b. Levels of proinflammatory interleukin-8 (IL-8) and phosphorylated IκBα were measured by enzyme-linked immunosorbent assays (ELISA) and Luminex assays, respectively. The neutrophils expressed all four adenosine receptor subtypes (A1, A2A, A2B, and A3 receptors), but A3 receptors were not expressed by UROtsa cells. UPEC stimulated neutrophil transuroepithelial migration, which was significantly decreased in response to the specific A2A receptor agonist CGS 21680. The inhibitory effect of CGS 21680 on neutrophil migration was reversed by the A2A receptor antagonist SCH 58261. The production of chemotactic IL-8 and the expression of the adhesion molecule ICAM-1 or CD11b were not significantly affected by CGS 21680. However, a significant decrease in the level of phosporylated IκBα was revealed in response to CGS 21680. In conclusion, UPEC infection in vitro evoked neutrophil migration through a multilayered human uroepithelium. The UPEC-evoked neutrophil transmigration decreased in response to A2A receptor activation, possibly through inhibition of NF-κB signaling pathways. PMID:21646447

  13. PEDF Inhibits the Activation of NLRP3 Inflammasome in Hypoxia Cardiomyocytes through PEDF Receptor/Phospholipase A2.

    PubMed

    Zhou, Zhongxin; Wang, Zhu; Guan, Qiuhua; Qiu, Fan; Li, Yufeng; Liu, Zhiwei; Zhang, Hao; Dong, Hongyan; Zhang, Zhongming

    2016-12-12

    The nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome has been linked to sterile inflammation, which is involved in ischemic injury in myocardial cells. Pigment epithelium-derived factor (PEDF) is a multifunctional secreted glycoprotein with many biological activities, such as anti-inflammatory, antioxidant and anti-angiogenic properties. However, it is not known whether and how PEDF acts to regulate the activation of the NLRP3 inflammasome in cardiomyocytes. In the present study, we used the neonatal cardiomyocytes models of ischemia-like conditions to evaluate the mitochondrial fission and the activation of the NLRP3 inflammasome. We also determined the mechanism by which PEDF inhibits hypoxia-induced activation of the NLRP3 inflammasome. We found that PEDF decreased the activation of the NLRP3 inflammasome in neonatal cardiomyocytes through pigment epithelial-derived factor receptor/calcium-independent phospholipase A2 (PEDFR/iPLA2). Meanwhile, PEDF reduced Drp1-induced mitochondrial fission and mitochondrial fission-induced mitochondrial DNA (mtDNA), as well as mitochondrial reactive oxygen species (mtROS) release into cytosol through PEDFR/iPLA2. We also found that PEDF inhibited mitochondrial fission-induced NLRP3 inflammasome activation. Furthermore, previous research has found that endogenous cytosolic mtDNA and mtROS can serve as activators of NLRP3 inflammasome activity. Therefore, we hypothesized that PEDF can protect against hypoxia-induced activation of the NLRP3 inflammasome by inhibiting mitochondrial fission though PEDFR/iPLA2.

  14. PEDF Inhibits the Activation of NLRP3 Inflammasome in Hypoxia Cardiomyocytes through PEDF Receptor/Phospholipase A2

    PubMed Central

    Zhou, Zhongxin; Wang, Zhu; Guan, Qiuhua; Qiu, Fan; Li, Yufeng; Liu, Zhiwei; Zhang, Hao; Dong, Hongyan; Zhang, Zhongming

    2016-01-01

    The nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome has been linked to sterile inflammation, which is involved in ischemic injury in myocardial cells. Pigment epithelium-derived factor (PEDF) is a multifunctional secreted glycoprotein with many biological activities, such as anti-inflammatory, antioxidant and anti-angiogenic properties. However, it is not known whether and how PEDF acts to regulate the activation of the NLRP3 inflammasome in cardiomyocytes. In the present study, we used the neonatal cardiomyocytes models of ischemia-like conditions to evaluate the mitochondrial fission and the activation of the NLRP3 inflammasome. We also determined the mechanism by which PEDF inhibits hypoxia-induced activation of the NLRP3 inflammasome. We found that PEDF decreased the activation of the NLRP3 inflammasome in neonatal cardiomyocytes through pigment epithelial-derived factor receptor/calcium-independent phospholipase A2 (PEDFR/iPLA2). Meanwhile, PEDF reduced Drp1-induced mitochondrial fission and mitochondrial fission-induced mitochondrial DNA (mtDNA), as well as mitochondrial reactive oxygen species (mtROS) release into cytosol through PEDFR/iPLA2. We also found that PEDF inhibited mitochondrial fission-induced NLRP3 inflammasome activation. Furthermore, previous research has found that endogenous cytosolic mtDNA and mtROS can serve as activators of NLRP3 inflammasome activity. Therefore, we hypothesized that PEDF can protect against hypoxia-induced activation of the NLRP3 inflammasome by inhibiting mitochondrial fission though PEDFR/iPLA2. PMID:27973457

  15. Quercetin and cyanidin-3-glucoside protect against photooxidation and photodegradation of A2E in retinal pigment epithelial cells.

    PubMed

    Wang, Yong; Kim, Hye Jin; Sparrow, Janet R

    2017-07-01

    A family of photoreactive retinaldehyde-derived molecules accumulate in retinal pigment epithelial cells with age; this accumulation is implicated in some retinal diseases. One of these compounds is the diretinal fluorophore A2E. Here we compared polyphenols for their ability to suppress the photooxidation and photodegradation of A2E. In cells that had accumulated A2E and were irradiated with short-wavelength light, quercetin, cyanidin-3-glucoside, ferulic acid and chlorogenic acid diminished cellular levels of reactive oxygen species, but only quercetin and cyanidin-3-glucoside promoted cell viability. By chromatographic quantitation, quercetin and cyanidin-3-glucoside reduced the consumption of A2E by photooxidation in both cell- and cell-free assays. With ultra-high performance liquid chromatography-mass spectrometry, quercetin and cyanidin-3-glucoside also inhibited the formation of photooxidized-A2E species. While photodegradation of A2E is known to result in the release of reactive carbonyls, we demonstrated that quercetin and cyanidin-3-glucoside decreased the formation of methylglyoxal adducts in the cells, and reduced the expression of mRNA encoding receptor for advanced glycation end products. These polyphenols also protected glutathione from reaction with photooxidized A2E. In rod outer segments incubated with all-trans-retinal to generate bisretinoid, followed by irradiation, quercetin and cyanidin-3-glucoside reduced release of the lipid peroxidation product 4-hydroxynonenal. In conclusion, quercetin and cyanidin-3-glucoside can guard against photooxidative processes in retina. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Ghrelin protects MES23.5 cells against rotenone via inhibiting mitochondrial dysfunction and apoptosis.

    PubMed

    Yu, Jianhan; Xu, Huamin; Shen, Xiaoli; Jiang, Hong

    2016-04-01

    Ghrelin is an endogenous ligand for the growth hormone secretagogue (GHS) receptor and has several important physiological functions. Recently, particular attention has been paid to its neuroprotective effect. Rotenone is used to investigate the pathogenesis of Parkinson's disease (PD) for its ability to inhibit mitochondrial complex I. The current study was carried out to investigate the neuroprotective effects of ghrelin against rotenone in MES 23.5 dopaminergic cells and explored the possible mechanisms underlying this protection. Our results showed that rotenone induced significant decrease in cell viability which was counteracted by ghrelin treatment. In addition, rotenone challenge reduced mitochondrial membrane potential, inhibited the activity of mitochondrial complex I and depressed cytochrome C release from mitochondria. This mitochondrial dysfunction was reversed by ghrelin treatment. Furthermore, our results demonstrated that ghrelin protected MES23.5 cells against rotenone-induced apoptosis by inhibiting activation of caspase-3. Overall, our findings showed ghrelin provided protective effects on MES23.5 dopaminergic cells against rotenone via restoring mitochondrial dysfunction and inhibiting mitochondrial dependent apoptosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Dinitrophenol pretreatment of rat ventricular myocytes protects against damage by metabolic inhibition and reperfusion.

    PubMed

    Rodrigo, G C; Lawrence, C L; Standen, N B

    2002-05-01

    We have investigated the protective effects of pretreatment with the mitochondrial uncoupler 2,4-dinitrophenol on the cellular damage induced by metabolic inhibition (with cyanide and iodoacetic acid) and reperfusion in freshly isolated adult rat ventricular myocytes. Damage was assessed from changes in cell length and morphology measured using video microscopy. Intracellular Ca(2+), mitochondrial membrane potential, and NADH were measured using fura-2, tetramethylrhodamine ethyl ester and autofluorescence, respectively. During metabolic inhibition myocytes developed rigor, and on reperfusion 73.6+/-8.1% hypercontracted and 10.8+/-6.7% recovered contractile function in response to electrical stimulation. Intracellular Ca(2+) increased substantially, indicated by a rise in the fura-2 ratio (340/380 nm) on reperfusion from 0.86+/-0.04 to 1.93+/-0.18. Myocytes pretreated with substrate-free Tyrode containing 50 microm dinitrophenol showed reduced reperfusion injury: 29.0+/-7.4% of cells hypercontracted and 65.3+/-7.3% recovered contractile function (P<0.001 vs control). The fura-2 ratio on reperfusion was also lower at 1.01+/-0.08. Fluorescence measurements showed that dinitrophenol caused mitochondrial depolarisation, and decreased NADH. The presence of the substrates glucose and pyruvate reduced these effects, and abolished the protection against damage by metabolic inhibition and reperfusion. However protection was unaffected by block of ATP-sensitive potassium channels. Thus the protective effects of pretreatment with dinitrophenol may result from a reduction in NADH in response to mitochondrial depolarisation.

  18. Alpha-lipoic acid protects cardiomyocytes against hypoxia/reoxygenation injury by inhibiting autophagy

    SciTech Connect

    Cao, Xueming; Chen, Aihua Yang, Pingzhen; Song, Xudong; Liu, Yingfeng; Li, Zhiliang; Wang, Xianbao; Wang, Lizi; Li, Yunpeng

    2013-11-29

    Highlights: •We observed the cell viability and death subjected to H/R in H9c2 cardiomyocytes. •We observed the degree of autophagy subjected to H/R in H9c2 cardiomyocytes. •LA inhibited the degree of autophagy in parallel to the enhanced cell survival. •LA inhibited the autophagy in parallel to the decreased total cell death. •We concluded that LA protected cardiomyocytes against H/R by inhibiting autophagy. -- Abstract: Hypoxia/reoxygenation (H/R) is an important in vitro model for exploring the molecular mechanisms and functions of autophagy during myocardial ischemia/reperfusion (I/R). Alpha-lipoic acid (LA) plays an important role in the etiology of cardiovascular disease. Autophagy is widely implicated in myocardial I/R injury. We assessed the degree of autophagy by pretreatment with LA exposed to H/R in H9c2 cell based on the expression levels of Beclin-1, LC3II/LC3I, and green fluorescent protein-labeled LC3 fusion proteins. Autophagic vacuoles were confirmed in H9c2 cells exposed to H/R using transmission electron microscopy. Our findings indicated that pretreatment with LA inhibited the degree of autophagy in parallel to the enhanced cell survival and decreased total cell death in H9c2 cells exposed to H/R. We conclude that LA protects cardiomyocytes against H/R injury by inhibiting autophagy.

  19. Atorvastatin protects cardiomyocytes from oxidative stress by inhibiting LOX-1 expression and cardiomyocyte apoptosis.

    PubMed

    Zhang, Lei; Cheng, Linfang; Wang, Qiqi; Zhou, Dongchen; Wu, Zhigang; Shen, Ling; Zhang, Li; Zhu, Jianhua

    2015-03-01

    Coronary artery disease (CAD) is a major health problem worldwide. The most severe form of CAD is acute coronary syndrome (ACS). Recent studies have demonstrated the beneficial role of atorvastatin in ACS; however, the mechanisms underlying this effect have not been fully clarified. Growing evidence indicates that activation of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) plays an important role in oxidative stress-induced cardiomyocyte apoptosis during ACS. In this study, we examined whether atorvastatin inhibits H2O2-induced LOX-1 expression and H9c2 cardiomyocyte apoptosis, and investigated the underlying signaling pathway. Treatment of H9c2 cardiomyocytes with H2O2 resulted in elevated expression of LOX-1 mRNA and protein, as well as increased caspase-3 and -9 protein expression and cell apoptosis. H2O2-induced LOX-1 expression, caspase protein expression, and cardiomyocyte apoptosis were attenuated by pretreatment with atorvastatin. Atorvastatin activated H2O2-inhibited phosphorylation of Akt in a concentration-dependent manner. The Akt inhibitor, LY294002, inhibited the effect of atorvastatin on inducing Akt phosphorylation and on suppressing H2O2-mediated caspase up-regulation and cell apoptosis. These findings indicate that atorvastatin protects cardiomyocyte from oxidative stress via inhibition of LOX-1 expression and apoptosis, and that activation of H2O2-inhibited phosphorylation of Akt may play an important role in the protective function of atorvastatin.

  20. Protective effect of creatine against inhibition by methylglyoxal of mitochondrial respiration of cardiac cells.

    PubMed

    Roy, Soumya Sinha; Biswas, Swati; Ray, Manju; Ray, Subhankar

    2003-06-01

    Previous publications from our laboratory have shown that methylglyoxal inhibits mitochondrial respiration of malignant and cardiac cells, but it has no effect on mitochondrial respiration of other normal cells [Biswas, Ray, Misra, Dutta and Ray (1997) Biochem. J. 323, 343-348; Ray, Biswas and Ray (1997) Mol. Cell. Biochem. 171, 95-103]. However, this inhibitory effect of methylglyoxal is not significant in cardiac tissue slices. Moreover, post-mitochondrial supernatant (PMS) of cardiac cells could almost completely protect the mitochondrial respiration against the inhibitory effect of methylglyoxal. A systematic search indicated that creatine present in cardiac cells is responsible for this protective effect. Glutathione has also some protective effect. However, creatine phosphate, creatinine, urea, glutathione disulphide and beta-mercaptoethanol have no protective effect. The inhibitory and protective effects of methylglyoxal and creatine respectively on cardiac mitochondrial respiration were studied with various concentrations of both methylglyoxal and creatine. Interestingly, neither creatine nor glutathione have any protective effect on the inhibition by methylglyoxal on the mitochondrial respiration of Ehrlich ascites carcinoma cells. The creatine and glutathione contents of several PMS, which were tested for the possible protective effect, were measured. The activities of two important enzymes, namely glyoxalase I and creatine kinase, which act upon glutathione plus methylglyoxal and creatine respectively, were also measured in different PMS. Whether mitochondrial creatine kinase had any role in the protective effect of creatine had also been investigated using 1-fluoro-2,4-dinitrobenzene, an inhibitor of creatine kinase. The differential effect of creatine on mitochondria of cardiac and malignant cells has been discussed with reference to the therapeutic potential of methylglyoxal.

  1. Varespladib inhibits secretory phospholipase A2 in bronchoalveolar lavage of different types of neonatal lung injury.

    PubMed

    De Luca, Daniele; Minucci, Angelo; Trias, Joaquim; Tripodi, Domenico; Conti, Giorgio; Zuppi, Cecilia; Capoluongo, Ettore

    2012-05-01

    Secretory phospholipase A2 (sPLA2), which links surfactant catabolism and lung inflammation, is associated with lung stiffness, surfactant dysfunction, and degree of respiratory support in acute respiratory distress syndrome and in some forms of neonatal lung injury. Varespladib potently inhibits sPLA2 in animal models. The authors investigate varespladib ex vivo efficacy in different forms of neonatal lung injury. Bronchoalveolar lavage fluid was obtained from 40 neonates affected by hyaline membrane disease, infections, or meconium aspiration and divided in 4 aliquots added with increasing varespladib or saline. sPLA2 activity, proteins, and albumin were measured. Dilution was corrected with the urea ratio. Varespladib was also tested in vitro against pancreatic sPLA2 mixed with different albumin concentration. Varespladib was able to inhibit sPLA2 in the types of neonatal lung injury investigated. sPLA2 activity was reduced in hyaline membrane disease (P < .0001), infections (P = .003), and meconium aspiration (P = .04) using 40 µM varespladib; 10 µM was able to lower enzyme activity (P = .001), with an IC(50) of 87 µM. An inverse relationship existed between protein level and activity reduction (r = 0.5; P = .029). The activity reduction/protein ratio tended to be higher in hyaline membrane disease. Varespladib efficacy was higher in vitro than in lavage fluids obtained from neonates (P < .001).

  2. Inhibition of viral RNA synthesis in canine distemper virus infection by proanthocyanidin A2.

    PubMed

    Gallina, Laura; Dal Pozzo, Fabiana; Galligioni, Viola; Bombardelli, Ezio; Scagliarini, Alessandra

    2011-12-01

    Canine distemper virus (CDV) is a contagious and multisystemic viral disease that affects domestic and wild canines as well as other terrestrial and aquatic carnivores. The disease in dogs is often fatal and no specific antiviral therapy is currently available. In this study, we evaluated the in vitro antiviral activity against CDV of proanthocyanidin A2 (PA2), a phenolic dimer belonging to the class of condensed tannins present in plants. Our results showed that PA2 exerted in vitro antiviral activity against CDV with a higher selectivity index compared to ribavirin, included in our study for the previously tested anti-CDV activity. The time of addition assay led us to observe that PA2 was able to decrease the viral RNA synthesis and to reduce progeny virus liberation, at different times post infection suggesting multiple mechanisms of action including inhibition of viral replicative complex and modulation of the redox milieu. These data suggest that PA2, isolated from the bark of Aesculus hippocastanum, has potential usefulness as an anti-CDV compound inhibiting viral replication.

  3. Inhibition of Rac1 signaling by lovastatin protects against anthracycline-induced cardiac toxicity

    PubMed Central

    Huelsenbeck, J; Henninger, C; Schad, A; Lackner, K J; Kaina, B; Fritz, G

    2011-01-01

    Normal tissue damage limits the efficacy of anticancer therapy. For anthracyclines, the clinically most relevant adverse effect is cardiotoxicity. The mechanisms involved are poorly understood and putative cardioprotectants are controversially discussed. Here, we show that the lipid-lowering drug lovastatin protects rat H9c2 cardiomyoblasts from doxorubicin in vitro. Protection by lovastatin is related to inhibition of the Ras-homologous GTPase Rac1. It rests on a reduced formation of DNA double-strand breaks, resulting from the inhibition of topoisomerase II by doxorubicin. Doxorubicin transport and reactive oxygen species are not involved. Protection by lovastatin was confirmed in vivo. In mice, lovastatin mitigated acute doxorubicin-induced heart and liver damage as indicated by reduced mRNA levels of the pro-fibrotic cytokine connective tissue growth factor (CTGF) and pro-inflammatory cytokines, respectively. Lovastatin also protected from doxorubicin-provoked subacute cardiac damage as shown by lowered mRNA levels of CTGF and atrial natriuretic peptide. Increase in the serum concentration of troponin I and cardiac fibrosis following doxorubicin treatment were also reduced by lovastatin. Whereas protecting the heart from harmful doxorubicin effects, lovastatin augmented its anticancer efficacy in a mouse xenograft model with human sarcoma cells. These data show that statins lower the incidence of cardiac tissue injury after anthracycline treatment in a Rac1-dependent manner, without impairing the therapeutic efficacy. PMID:21833028

  4. Radical scavenging glycoprotein inhibiting cyclooxygenase-2 and thromboxane A2 synthase from aloe vera gel.

    PubMed

    Yagi, A; Kabash, A; Mizuno, K; Moustafa, S M; Khalifa, T I; Tsuji, H

    2003-03-01

    An active glycoprotein fraction containing 58 % protein was isolated from Aloe vera gel by precipitation with 55 % ammonium sulfate followed by gel permeation using DEAE-Sephacel A-25, Sepharose 6B and Sephadex G-50 columns in a yield of 3 x 10 -3 %. The glycoprotein fraction showed a single band corresponding to a subunit of verectin at the same position when stained with both Coomassie brilliant blue and periodic acid-Schiff reagents on 18 % SDS-PAGE. The molecular weight (14 kDa) was confirmed by Sephadex G-50 column chromatography. The glycoprotein fraction showed a radical scavenging activity against superoxide anion generated by the xanthine-xanthine oxidase system as well as inhibition of cyclooxygenase-2 and reduction of thromboxane A 2 synthase level in vitro.

  5. Phospholipase A2 inhibitors protect against prion and Aβ mediated synapse degeneration

    PubMed Central

    2010-01-01

    Background An early event in the neuropathology of prion and Alzheimer's diseases is the loss of synapses and a corresponding reduction in the level of synaptophysin, a pre-synaptic membrane protein essential for neurotransmission. The molecular mechanisms involved in synapse degeneration in these diseases are poorly understood. In this study the process of synapse degeneration was investigated by measuring the synaptophysin content of cultured neurones incubated with the prion derived peptide (PrP82-146) or with Aβ1-42, a peptide thought to trigger pathogenesis in Alzheimer's disease. A pharmacological approach was used to screen cell signalling pathways involved in synapse degeneration. Results Pre-treatment with phospholipase A2 inhibitors (AACOCF3, MAFP and aristolochic acids) protected against synapse degeneration in cultured cortical and hippocampal neurones incubated with PrP82-146 or Aβ1-42. Synapse degeneration was also observed following the addition of a specific phospholipase A2 activating peptide (PLAP) and the addition of PrP82-146 or Aβ1-42 activated cytoplasmic phospholipase A2 within synapses. Activation of phospholipase A2 is the first step in the generation of platelet-activating factor (PAF) and PAF receptor antagonists (ginkgolide B, Hexa-PAF and CV6029) protected against synapse degeneration induced by PrP82-146, Aβ1-42 and PLAP. PAF facilitated the production of prostaglandin E2, which also caused synapse degeneration and pre-treatment with the prostanoid E receptor antagonist AH13205 protected against PrP82-146, Aβ1-42 and PAF induced synapse degeneration. Conclusions Our results are consistent with the hypothesis that PrP82-146 and Aβ1-42trigger abnormal activation of cytoplasmic phospholipase A2 resident within synapses, resulting in elevated levels of PAF and prostaglandin E2that cause synapse degeneration. Inhibitors of this pathway that can cross the blood brain barrier may protect against the synapse degeneration seen during

  6. UVB and caffeine: inhibiting the DNA damage response to protect against the adverse effects of UVB.

    PubMed

    Kerzendorfer, Claudia; O'Driscoll, Mark

    2009-07-01

    The incidence of sunlight-induced skin cancer is increasing. Mouse studies indicate that caffeine, administered orally or topically, promotes apoptosis of UVB-irradiated keratinocytes. In this issue, Heffernan and colleagues identify the pathway targeted by caffeine and suggest that inhibition of this DNA damage response may offer a viable therapeutic option for nonmelanoma skin cancer. This potentially represents an important protective or therapeutic option from the most unlikely of sources: your daily coffee.

  7. Ascorbate protects against tert-butyl hydroperoxide inhibition of erythrocyte membrane Ca2+ + Mg2(+)-ATPase.

    PubMed

    Moore, R B; Bamberg, A D; Wilson, L C; Jenkins, L D; Mankad, V N

    1990-05-01

    The incubation of erythrocyte suspensions or isolated membranes containing a residual amount of hemoglobin (0.04% of original cellular hemoglobin) with tert-butyl hydroperoxide (tBHP, 0.5 mM) caused significant inhibition of basal and calmodulin-stimulated Ca2+ + Mg2(+)-ATPase activities and the formation of thiobarbituric acid reactive products measured as malondialdehyde. In contrast, the treatment of white ghosts (membranes not containing hemoglobin) with tBHP (0.5 mM) did not lead to appreciable enzyme inhibition within the first 20 min and did not result in malondialdehyde (MDA) formation. However, the addition of either 10 microM hemin or 100 microM ferrous chloride + 1 mM ADP to white ghosts produced hydroperoxide effects similar to those in pink ghosts (membranes with 0.04% hemoglobin). The concentrations of hemin and ferrous chloride which caused half-maximal inhibition of Ca2+ + Mg2(+)-ATPase activity at 10 min were 0.5 and 30 microM, respectively. The effects of several antioxidants (mannitol, thiourea, hydroxyurea, butylated hydroxytoluene, and ascorbate) were investigated for their protective effects against oxidative changes resulting from tBHP treatment. Over a 30-min incubation period only ascorbate significantly reduced the enzyme inhibition, MDA formation, and protein polymerization. Thiourea and hydroxyurea decreased MDA formation and protein polymerization but failed to protect against the enzyme inhibition. Butylated hydroxytoluene was similar to thiourea and hydroxyurea but with better protection at 10 min. Mannitol, under these conditions, was an ineffective antioxidant for all parameters tested.

  8. Oral Administration of Probiotics Inhibits Absorption of the Heavy Metal Cadmium by Protecting the Intestinal Barrier.

    PubMed

    Zhai, Qixiao; Tian, Fengwei; Zhao, Jianxin; Zhang, Hao; Narbad, Arjan; Chen, Wei

    2016-07-15

    The heavy metal cadmium (Cd) is an environmental pollutant that causes adverse health effects in humans and animals. Our previous work demonstrated that oral administration of probiotics can significantly inhibit Cd absorption in the intestines of mice, but further evidence is needed to gain insights into the related protection mode. The goal of this study was to evaluate whether probiotics can inhibit Cd absorption through routes other than the Cd binding, with a focus on gut barrier protection. In the in vitro assay, both the intervention and therapy treatments of Lactobacillus plantarum CCFM8610 alleviated Cd-induced cytotoxicity in the human intestinal cell line HT-29 and protected the disruption of tight junctions in the cell monolayers. In a mouse model, probiotics with either good Cd-binding or antioxidative ability increased fecal Cd levels and decreased Cd accumulation in the tissue of Cd-exposed mice. Compared with the Cd-only group, cotreatment with probiotics also reversed the disruption of tight junctions, alleviated inflammation, and decreased the intestinal permeability of mice. L. plantarum CCFM8610, a strain with both good Cd binding and antioxidative abilities, exhibited significantly better protection than the other two strains. These results suggest that along with initial intestinal Cd sequestration, probiotics can inhibit Cd absorption by protecting the intestinal barrier, and the protection is related to the alleviation of Cd-induced oxidative stress. A probiotic with both good Cd-binding and antioxidative capacities can be used as a daily supplement for the prevention of oral Cd exposure. The heavy metal cadmium (Cd) is an environmental pollutant that causes adverse health effects in humans and animals. For the general population, food and drinking water are the main sources of Cd exposure due to the biomagnification of Cd within the food chain; therefore, the intestinal tract is the first organ that is susceptible to Cd contamination

  9. Oral Administration of Probiotics Inhibits Absorption of the Heavy Metal Cadmium by Protecting the Intestinal Barrier

    PubMed Central

    Zhai, Qixiao; Tian, Fengwei; Zhao, Jianxin; Zhang, Hao; Narbad, Arjan

    2016-01-01

    ABSTRACT The heavy metal cadmium (Cd) is an environmental pollutant that causes adverse health effects in humans and animals. Our previous work demonstrated that oral administration of probiotics can significantly inhibit Cd absorption in the intestines of mice, but further evidence is needed to gain insights into the related protection mode. The goal of this study was to evaluate whether probiotics can inhibit Cd absorption through routes other than the Cd binding, with a focus on gut barrier protection. In the in vitro assay, both the intervention and therapy treatments of Lactobacillus plantarum CCFM8610 alleviated Cd-induced cytotoxicity in the human intestinal cell line HT-29 and protected the disruption of tight junctions in the cell monolayers. In a mouse model, probiotics with either good Cd-binding or antioxidative ability increased fecal Cd levels and decreased Cd accumulation in the tissue of Cd-exposed mice. Compared with the Cd-only group, cotreatment with probiotics also reversed the disruption of tight junctions, alleviated inflammation, and decreased the intestinal permeability of mice. L. plantarum CCFM8610, a strain with both good Cd binding and antioxidative abilities, exhibited significantly better protection than the other two strains. These results suggest that along with initial intestinal Cd sequestration, probiotics can inhibit Cd absorption by protecting the intestinal barrier, and the protection is related to the alleviation of Cd-induced oxidative stress. A probiotic with both good Cd-binding and antioxidative capacities can be used as a daily supplement for the prevention of oral Cd exposure. IMPORTANCE The heavy metal cadmium (Cd) is an environmental pollutant that causes adverse health effects in humans and animals. For the general population, food and drinking water are the main sources of Cd exposure due to the biomagnification of Cd within the food chain; therefore, the intestinal tract is the first organ that is susceptible to Cd

  10. Topoisomerase 1 inhibition suppresses inflammatory genes and protects from death by inflammation.

    PubMed

    Rialdi, Alex; Campisi, Laura; Zhao, Nan; Lagda, Arvin Cesar; Pietzsch, Colette; Ho, Jessica Sook Yuin; Martinez-Gil, Luis; Fenouil, Romain; Chen, Xiaoting; Edwards, Megan; Metreveli, Giorgi; Jordan, Stefan; Peralta, Zuleyma; Munoz-Fontela, Cesar; Bouvier, Nicole; Merad, Miriam; Jin, Jian; Weirauch, Matthew; Heinz, Sven; Benner, Chris; van Bakel, Harm; Basler, Christopher; García-Sastre, Adolfo; Bukreyev, Alexander; Marazzi, Ivan

    2016-05-27

    The host innate immune response is the first line of defense against pathogens and is orchestrated by the concerted expression of genes induced by microbial stimuli. Deregulated expression of these genes is linked to the initiation and progression of diseases associated with exacerbated inflammation. We identified topoisomerase 1 (Top1) as a positive regulator of RNA polymerase II transcriptional activity at pathogen-induced genes. Depletion or chemical inhibition of Top1 suppresses the host response against influenza and Ebola viruses as well as bacterial products. Therapeutic pharmacological inhibition of Top1 protected mice from death in experimental models of lethal inflammation. Our results indicate that Top1 inhibition could be used as therapy against life-threatening infections characterized by an acutely exacerbated immune response.

  11. Topoisomerase 1 inhibition suppresses inflammatory genes and protects from death by inflammation

    PubMed Central

    Zhao, Nan; Lagda, Arvin Cesar; Pietzsch, Colette; Ho, Jessica Sook Yuin; Martinez-Gil, Luis; Fenouil, Romain; Chen, Xiaoting; Edwards, Megan; Metreveli, Giorgi; Jordan, Stefan; Peralta, Zuleyma; Munoz-Fontela, Cesar; Bouvier, Nicole; Merad, Miriam; Jin, Jian; Weirauch, Matthew; Heinz, Sven; Benner, Chris; van Bakel, Harm; Basler, Christopher; García-Sastre, Adolfo; Bukreyev, Alexander; Marazzi, Ivan

    2016-01-01

    The host innate immune response is the first line of defense against pathogens and is orchestrated by the concerted expression of genes induced by microbial stimuli. Deregulated expression of these genes is linked to the initiation and progression of diseases associated with exacerbated inflammation. We identified topoisomerase 1 (Top1) as a positive regulator of RNA polymerase II transcriptional activity at pathogen-induced genes. Depletion or chemical inhibition of Top1 suppresses the host response against influenza and Ebola viruses as well as bacterial products. Therapeutic pharmacological inhibition of Top1 protected mice from death in experimental models of lethal inflammation. Our results indicate that Top1 inhibition could be used as therapy against life-threatening infections characterized by an acutely exacerbated immune response. PMID:27127234

  12. PHD Inhibition Mitigates and Protects Against Radiation-Induced Gastrointestinal Toxicity via HIF2

    PubMed Central

    Taniguchi, Cullen M.; Miao, Yu Rebecca; Diep, Anh N.; Wu, Colleen; Rankin, Erinn B.; Atwood, Todd F.; Xing, Lei; Giaccia, Amato J.

    2014-01-01

    Radiation-induced gastrointestinal (GI) toxicity can be a major source of morbidity and mortality after radiation exposure. There is an unmet need for effective preventative or mitigative treatments against the potentially fatal diarrhea and water loss induced by radiation damage to the GI tract. We report that prolyl hydroxylase inhibition by genetic knockout or pharmacologic inhibition of all PHD isoforms by the small molecule dimethyloxyallylglycine (DMOG) increases HIF expression, improves epithelial integrity, reduces apoptosis, and increases intestinal angiogenesis, all of which are essential for radioprotection. HIF2, but not HIF1, is both necessary and sufficient to prevent radiation-induced GI toxicity and death. Increased VEGF expression contributes to the protective effects of HIF2, since inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality is reduced from abdominal or total body irradiation even when DMOG is given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a new treatment strategy to protect against and mitigate GI toxicity from both therapeutic radiation and potentially lethal radiation exposures. PMID:24828078

  13. PHD inhibition mitigates and protects against radiation-induced gastrointestinal toxicity via HIF2.

    PubMed

    Taniguchi, Cullen M; Miao, Yu Rebecca; Diep, Anh N; Wu, Colleen; Rankin, Erinn B; Atwood, Todd F; Xing, Lei; Giaccia, Amato J

    2014-05-14

    Radiation-induced gastrointestinal (GI) toxicity can be a major source of morbidity and mortality after radiation exposure. There is an unmet need for effective preventative or mitigative treatments against the potentially fatal diarrhea and water loss induced by radiation damage to the GI tract. We report that prolyl hydroxylase inhibition by genetic knockout or pharmacologic inhibition of all PHD (prolyl hydroxylase domain) isoforms by the small-molecule dimethyloxallyl glycine (DMOG) increases hypoxia-inducible factor (HIF) expression, improves epithelial integrity, reduces apoptosis, and increases intestinal angiogenesis, all of which are essential for radioprotection. HIF2, but not HIF1, is both necessary and sufficient to prevent radiation-induced GI toxicity and death. Increased vascular endothelial growth factor (VEGF) expression contributes to the protective effects of HIF2, because inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality from abdominal or total body irradiation was reduced even when DMOG was given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a treatment strategy to protect against and mitigate GI toxicity from both therapeutic radiation and potentially lethal radiation exposures.

  14. Protective effect of halothane anesthesia on retinal light damage: inhibition of metabolic rhodopsin regeneration.

    PubMed

    Keller, C; Grimm, C; Wenzel, A; Hafezi, F; Remé, C

    2001-02-01

    To determine whether the volatile anesthetic halothane protects against light-induced photoreceptor degeneration in the rodent retina. Albino mice and rats were anesthetized with halothane and exposed to high levels of white or blue light. Nonanesthetized animals served as controls. Retinal morphology was assessed by light microscopy, and apoptosis of photoreceptor cells was verified by detection of fragmented genomic DNA and in situ staining of apoptotic nuclei (TUNEL assay). Rhodopsin regeneration after bleaching was determined by measuring rhodopsin levels in retinas of mice or rats at different time points in darkness. Halothane anesthesia reversibly inhibited metabolic rhodopsin regeneration and thus prevented rhodopsin from absorbing high numbers of photons during light exposure. Consequently, photoreceptors of mice and rats anesthetized with halothane were completely protected against degeneration induced by white light. In remarkable contrast, however, halothane anesthesia did not protect against blue-light-induced photoreceptor cell death. After the initial bleach, halothane impeded photon absorption by rhodopsin by inhibiting metabolic rhodopsin regeneration. Apparently, the rhodopsin-mediated uptake of the critical number of photons to initiate white light-induced retinal degeneration was prevented. In contrast, halothane did not protect the retina against blue light. Blue light can efficiently restore functional rhodopsin from bleaching intermediates through a process termed photoreversal of bleaching. This process does not depend on the visual cycle via the pigment epithelium but nevertheless enables rhodopsin molecules to absorb the critical number of photons required to induce retinal degeneration.

  15. Picroside II protects myocardium from ischemia/reperfusion-induced injury through inhibition of the inflammatory response

    PubMed Central

    Li, Jian-Zhe; Xie, Mei-Qing; Mo, Dan; Zhao, Xiao-Fang; Yu, Shu-Yi; Liu, Li-Juan; Wu, Cheng; Yang, Yang

    2016-01-01

    The inflammatory response is important in the pathogenesis of myocardial ischemia/reperfusion (I/R) injury. Picroside II, the primary active constituent of Picrorhizae, has been reported to protect the myocardium from I/R-induced injury, however, the exact mechanism underlying these protective effects remains unclear. The aim of the present study was to investigate the mechanism underlying the protective effects of picroside II on I/R-induced myocardial injury. Adult male Sprague-Dawley rats underwent 1 h left coronary artery occlusion followed by 3 h reperfusion. Picroside II was administered (10 mg/kg) via the tail vein 30 min prior to left coronary artery occlusion. The results revealed that pretreatment of picroside II could significantly alleviate I/R-induced myocardial injury concomitantly with a decrease in inflammatory factor production. In addition, picroside II was also able to decrease high mobility group box 1 (HMGB1) expression, and release and downregulate the expression of the receptor for advanced glycation end products (RAGE), toll-like receptor (TLR)-2 and TLR-4. Furthermore, picroside II was able to inhibit nuclear factor-κB (NF-κB) activation. The results indicated that the protective effect of picroside II on I/R-induced myocardial injury was associated, at least partly, with inhibition of the inflammatory response by suppressing the HMGB1-RAGE/TLR-2/TLR-4-NF-κB signaling pathway. PMID:28105084

  16. Contribution of epithelial innate immunity to systemic protection afforded by prolyl hydroxylase inhibition in murine colitis

    PubMed Central

    Keely, Simon; Campbell, Eric L.; Baird, Alan W.; Hansbro, Philip M.; Shalwitz, Robert A.; Kotsakis, Anna; McNamee, Eoin N.; Eltzschig, Holger K.; Kominsky, Douglas J.; Colgan, Sean P.

    2013-01-01

    Pharmacological stabilization of hypoxia-inducible factor (HIF) through prolyl hydroxylase (PHD) inhibition limits mucosal damage associated with models of murine colitis. However, little is known about how PHD inhibitors (PHDi) influence systemic immune function during mucosal inflammation or the relative importance of immunological changes to mucosal protection. We hypothesized that PHDi enhances systemic innate immune responses to colitis-associated bacteremia. Mice with colitis induced by TNBS were treated with AKB-4924, a new HIF-1 isoform-predominant PHDi and clinical, immunological and biochemical endpoints were assessed. Administration of AKB-4924 led to significantly reduced weight loss and disease activity compared to vehicle controls. Treated groups were pyrexic, but did not become subsequently hypothermic. PHDi treatment augmented epithelial barrier function and led to an approximately 50-fold reduction in serum endotoxin during colitis. AKB-4924 also decreased cytokines involved in pyrogenesis and hypothermia, significantly reducing serum levels of IL-1β, IL-6 and TNF-α, while increasing IL-10. Treatment offered no protection against colitis in epithelial-specific HIF-1α deficient mice, strongly implicating epithelial HIF-1α as the tissue target for AKB-4924-mediated protection. Taken together, these results indicate that inhibition of prolyl hydroxylase with AKB-4924 enhances innate immunity and identifies the epithelium is a central site of inflammatory protection afforded by PHDi in murine colitis. PMID:23695513

  17. Cytosolic PhospholipaseA2 Inhibition with PLA-695 Radiosensitizes Tumors in Lung Cancer Animal Models

    PubMed Central

    Ferraro, Daniel J.; Kotipatruni, Rama P.; Bhave, Sandeep R.; Jaboin, Jerry J.; Hallahan, Dennis E.

    2013-01-01

    Lung cancer remains the leading cause of cancer deaths in the United States and the rest of the world. The advent of molecularly directed therapies holds promise for improvement in therapeutic efficacy. Cytosolic phospholipase A2 (cPLA2) is associated with tumor progression and radioresistance in mouse tumor models. Utilizing the cPLA2 specific inhibitor PLA-695, we determined if cPLA2 inhibition radiosensitizes non small cell lung cancer (NSCLC) cells and tumors. Treatment with PLA-695 attenuated radiation induced increases of phospho-ERK and phospho-Akt in endothelial cells. NSCLC cells (LLC and A549) co-cultured with endothelial cells (bEND3 and HUVEC) and pre-treated with PLA-695 showed radiosensitization. PLA-695 in combination with irradiation (IR) significantly reduced migration and proliferation in endothelial cells (HUVEC & bEND3) and induced cell death and attenuated invasion by tumor cells (LLC &A549). In a heterotopic tumor model, the combination of PLA-695 and radiation delayed growth in both LLC and A549 tumors. LLC and A549 tumors treated with a combination of PLA-695 and radiation displayed reduced tumor vasculature. In a dorsal skin fold model of LLC tumors, inhibition of cPLA2 in combination with radiation led to enhanced destruction of tumor blood vessels. The anti-angiogenic effects of PLA-695 and its enhancement of the efficacy of radiotherapy in mouse models of NSCLC suggest that clinical trials for its capacity to improve radiotherapy outcomes are warranted. PMID:23894523

  18. Cytosolic phospholipaseA2 inhibition with PLA-695 radiosensitizes tumors in lung cancer animal models.

    PubMed

    Thotala, Dinesh; Craft, Jeffrey M; Ferraro, Daniel J; Kotipatruni, Rama P; Bhave, Sandeep R; Jaboin, Jerry J; Hallahan, Dennis E

    2013-01-01

    Lung cancer remains the leading cause of cancer deaths in the United States and the rest of the world. The advent of molecularly directed therapies holds promise for improvement in therapeutic efficacy. Cytosolic phospholipase A2 (cPLA2) is associated with tumor progression and radioresistance in mouse tumor models. Utilizing the cPLA2 specific inhibitor PLA-695, we determined if cPLA2 inhibition radiosensitizes non small cell lung cancer (NSCLC) cells and tumors. Treatment with PLA-695 attenuated radiation induced increases of phospho-ERK and phospho-Akt in endothelial cells. NSCLC cells (LLC and A549) co-cultured with endothelial cells (bEND3 and HUVEC) and pre-treated with PLA-695 showed radiosensitization. PLA-695 in combination with irradiation (IR) significantly reduced migration and proliferation in endothelial cells (HUVEC & bEND3) and induced cell death and attenuated invasion by tumor cells (LLC &A549). In a heterotopic tumor model, the combination of PLA-695 and radiation delayed growth in both LLC and A549 tumors. LLC and A549 tumors treated with a combination of PLA-695 and radiation displayed reduced tumor vasculature. In a dorsal skin fold model of LLC tumors, inhibition of cPLA2 in combination with radiation led to enhanced destruction of tumor blood vessels. The anti-angiogenic effects of PLA-695 and its enhancement of the efficacy of radiotherapy in mouse models of NSCLC suggest that clinical trials for its capacity to improve radiotherapy outcomes are warranted.

  19. 518A2 melanoma cells are protected by G3139 and other antineoplastic agents against the cytotoxic effects of DTIC.

    PubMed

    Benimetskaya, Luba; Miller, Paul; Stein, C A

    2005-01-01

    G3139 is an antisense Bcl-2 phosphorothioate oligonucleotide that has been combined with DTIC in a phase III clinical trial in melanoma. However, its actual mechanism of action in melanoma is controversial. Treatment of 518A2 melanoma cells with either G3139 or G4126 (a two-base mismatch) and then with light-activated DTIC caused these cells (but not SK-Mel-30 or 346.1 cells) to be protected against the cytotoxic effects of DTIC. This cytoprotection was not recapitulated with a phosphodiester congener of G3139 nor with a small interfering RNA (siRNA) also targeted to the Bcl-2 mRNA. Administering the drugs in reverse order also did not produce cytoprotection, and an 18- mer phosphorothioate homopolymer of thymidine was also inactive. Subsequently, it was discovered that gemcitibine and cis-platinum also induced cytoprotection to DTIC in this cell line, suggesting that the cytoprotection is a stress response to chemical proapoptotic stress. Cytoprotection was completely inhibited by O(6)-benzylguanine, an inhibitor of O(6)-guanosine alkyltransferase (OGAT) activity. However, a direct assay of OGAT activity demonstrated that 518A2 melanoma cells are essentially completely devoid of it, either basally or induced. The cytoprotection may thus be caused by a chemical stress-induced increase in mismatch repair activity.

  20. Phospholipase A2 from Trypanosoma brucei gambiense and Trypanosoma brucei brucei: inhibition by organotins.

    PubMed

    Shuaibu, M N; Kanbara, H; Yanagi, T; Ameh, D A; Bonire, J J; Nok, A J

    2001-11-01

    Activity and kinetics of phospholipase A2 (PLA2) from Trypanosoma brucei gambiense (Wellcome strain) and Trypanosoma brucei brucei (GUTat 3.1) were examined using two different fluorescent substrates. The activity in the supernatants of sonicated parasites was Ca2+-independent, strongly stimulated by Triton X-100 with optimum activity at 37 degrees C and pH 6.5-8.5. To encourage a possible interaction between the parasite enzyme and organotin compounds, fatty acid derivatives of dibutyltin dichloride were synthesized and evaluated as potential inhibitors of PLA2. The enzyme from the two-trypanosome species differ with respect to kinetic parameters and are noncompetitively inhibited by the organotin compounds. The Michaelis constant (KM) for PLA2 from T. b. brucei is 63.87 and 30.90 microM while for T. b. gambiense it is 119.64 and 32.91 microM for the substrates 1,2-bis-(1-pyrenebutanoyl)-sn-glycero-3-phosphocholine (PBGPC) and 2-(12-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)dodecanoyl-1-hexadecanoyl-sn-glycero-3-phosphocholine (NBDC12-HPC), respectively.

  1. Astrocyte-specific overexpression of Nrf2 protects striatal neurons from mitochondrial complex II inhibition.

    PubMed

    Calkins, Marcus J; Vargas, Marcelo R; Johnson, Delinda A; Johnson, Jeffrey A

    2010-06-01

    Nuclear factor E2-related factor 2 (Nrf2) is a transcription factor that is known to regulate a variety of cytoprotective genes through the antioxidant response element (ARE). This endogenous response is one of the major pathways by which cells are protected from xenobiotic or innate oxidative insults. Furthermore, in neural systems, astrocyte-specific activation of Nrf2 is known to protect neurons. In previous work, our laboratory found that Nrf2 protects from intrastriatal injections of the mitochondrial complex II inhibitor malonate. Here, we extend these results to show that multiple methods of astrocyte-specific Nrf2 overexpression provide protection from neurotoxicity in vivo. GFAP-Nrf2 transgenic mice are significantly more resistant to malonate lesioning. This outcome is associated with an increased basal resistance, but more so, an enhanced Nrf2 response to lesioning that attenuated the ensuing neurotoxicity. Furthermore, striatal transplantation of neuroprogenitor cells overexpressing Nrf2 that differentiate into astrocytes after grafting also significantly reduced malonate toxicity. Overall, these data establish that enhanced astrocytic Nrf2 response and Nrf2 preconditioning are both sufficient to protect from acute lesions from mitochondrial complex II inhibition.

  2. Astrocyte-Specific Overexpression of Nrf2 Protects Striatal Neurons from Mitochondrial Complex II Inhibition

    PubMed Central

    Calkins, Marcus J.; Vargas, Marcelo R.; Johnson, Delinda A.; Johnson, Jeffrey A.

    2010-01-01

    Nuclear factor E2-related factor 2 (Nrf2) is a transcription factor that is known to regulate a variety of cytoprotective genes through the antioxidant response element (ARE). This endogenous response is one of the major pathways by which cells are protected from xenobiotic or innate oxidative insults. Furthermore, in neural systems, astrocyte-specific activation of Nrf2 is known to protect neurons. In previous work, our laboratory found that Nrf2 protects from intrastriatal injections of the mitochondrial complex II inhibitor malonate. Here, we extend these results to show that multiple methods of astrocyte-specific Nrf2 overexpression provide protection from neurotoxicity in vivo. GFAP-Nrf2 transgenic mice are significantly more resistant to malonate lesioning. This outcome is associated with an increased basal resistance, but more so, an enhanced Nrf2 response to lesioning that attenuated the ensuing neurotoxicity. Furthermore, striatal transplantation of neuroprogenitor cells overexpressing Nrf2 that differentiate into astrocytes after grafting also significantly reduced malonate toxicity. Overall, these data establish that enhanced astrocytic Nrf2 response and Nrf2 preconditioning are both sufficient to protect from acute lesions from mitochondrial complex II inhibition. PMID:20211941

  3. Salidroside protects cortical neurons against glutamate-induced cytotoxicity by inhibiting autophagy.

    PubMed

    Yin, Wei-Yong; Ye, Qiang; Huang, Huan-Jie; Xia, Nian-Ge; Chen, Yan-Yan; Zhang, Yi; Qu, Qiu-Min

    2016-08-01

    Recent evidence suggests that glutamate-induced cytotoxicity contributes to autophagic neuron death and is partially mediated by increased oxidative stress. Salidroside has been demonstrated to have neuroprotective effects in glutamate-induced neuronal damage. The precise mechanism of its regulatory role in neuronal autophagy is, however, poorly understood. This study aimed to probe the effects and mechanisms of salidroside in glutamate-induced autophagy activation in cultured rat cortical neurons. Cell viability assay, Western blotting, coimmunoprecipitation, and small interfering RNA were performed to analyze autophagy activities during glutamate-evoked oxidative injury. We found that salidroside protected neonatal neurons from glutamate-induced apoptotic cell death. Salidroside significantly attenuated the LC3-II/LC3-I ratio and expression of Beclin-1, but increased (SQSTM1)/p62 expression under glutamate exposure. Pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, decreased LC3-II/LC3-I ratio, attenuated glutamate-induced cell injury, and mimicked some of the protective effects of salidroside against glutamate-induced cell injury. Molecular analysis demonstrated that salidroside inhibited cortical neuron autophagy in response to glutamate exposure through p53 signaling by increasing the accumulation of cytoplasmic p53. Salidroside inhibited the glutamate-induced dissociation of the Bcl-2-Beclin-1 complex with minor affects on the PI3K/Akt/mTOR signaling pathways. These data demonstrate that the inhibition of autophagy could be responsible for the neuroprotective effects of salidroside on glutamate-induced neuronal injury.

  4. Edaravone protects osteoblastic cells from dexamethasone through inhibiting oxidative stress and mPTP opening.

    PubMed

    Sun, Wen-xiao; Zheng, Hai-ya; Lan, Jun

    2015-11-01

    Existing evidences have emphasized an important role of oxidative stress in dexamethasone (Dex)-induced osteoblastic cell damages. Here, we investigated the possible anti-Dex activity of edaravone in osteoblastic cells, and studied the underlying mechanisms. We showed that edaravone dose-dependently attenuated Dex-induced death and apoptosis of established human or murine osteoblastic cells. Further, Dex-mediated damages to primary murine osteoblasts were also alleviated by edaravone. In osteoblastic cells/osteoblasts, Dex induced significant oxidative stresses, tested by increased levels of reactive oxygen species and lipid peroxidation, which were remarkably inhibited by edaravone. Meanwhile, edaravone repressed Dex-induced mitochondrial permeability transition pore (mPTP) opening, or mitochondrial membrane potential reduction, in osteoblastic cells/osteoblasts. Significantly, edaravone-induced osteoblast-protective activity against Dex was alleviated with mPTP inhibition through cyclosporin A or cyclophilin-D siRNA. Together, we demonstrate that edaravone protects osteoblasts from Dex-induced damages probably through inhibiting oxidative stresses and following mPTP opening.

  5. Actin and DNA Protect Histones from Degradation by Bacterial Proteases but Inhibit Their Antimicrobial Activity

    PubMed Central

    Sol, Asaf; Skvirsky, Yaniv; Blotnick, Edna; Bachrach, Gilad; Muhlrad, Andras

    2016-01-01

    Histones are small polycationic proteins located in the cell nucleus. Together, DNA and histones are integral constituents of the nucleosomes. Upon apoptosis, necrosis, and infection – induced cell death, histones are released from the cell. The extracellular histones have strong antimicrobial activity but are also cytotoxic and thought as mediators of cell death in sepsis. The antimicrobial activity of the cationic extracellular histones is inhibited by the polyanionic DNA and F-actin, which also become extracellular upon cell death. DNA and F-actin protect histones from degradation by the proteases of Pseudomonas aeruginosa and Porphyromonas gingivalis. However, though the integrity of the histones is protected, the activity of histones as antibacterial agents is lost. The inhibition of the histone’s antibacterial activity and their protection from proteolysis by DNA and F-actin indicate a tight electrostatic interaction between the positively charged histones and negatively charged DNA and F-actin, which may have physiological significance in maintaining the equilibrium between the beneficial antimicrobial activity of extracellular histones and their cytotoxic effects. PMID:27555840

  6. Increased Vesicular Monoamine Transporter 2 (VMAT2; Slc18a2) Protects against Methamphetamine Toxicity

    PubMed Central

    Lohr, Kelly M.; Stout, Kristen A.; Dunn, Amy R.; Wang, Minzheng; Salahpour, Ali; Guillot, Thomas S.; Miller, Gary W.

    2015-01-01

    The psychostimulant methamphetamine (METH) is highly addictive and neurotoxic to dopamine terminals. METH toxicity has been suggested to be due to the release and accumulation of dopamine in the cytosol of these terminals. The vesicular monoamine transporter 2 (VMAT2; SLC18A2) is a critical mediator of dopamine handling. Mice overexpressing VMAT2 (VMAT2-HI) have an increased vesicular capacity to store dopamine, thus augmenting striatal dopamine levels and dopamine release in the striatum. Based on the altered compartmentalization of intracellular dopamine in the VMAT2-HI mice, we assessed whether enhanced vesicular function was capable of reducing METH-induced damage to the striatal dopamine system. While wildtype mice show significant losses in striatal levels of the dopamine transporter (65% loss) and tyrosine hydroxylase (46% loss) following a 4 × 10 mg/kg METH dosing regimen, VMAT2-HI mice were protected from this damage. VMAT2-HI mice were also spared from the inflammatory response that follows METH treatment, showing an increase in astroglial markers that was approximately one-third of that of wildtype animals (117% vs 36% increase in GFAP, wildtype vs VMAT2-HI). Further analysis also showed that elevated VMAT2 level does not alter the ability of METH to increase core body temperature, a mechanism integral to the toxicity of the drug. Finally, the VMAT2-HI mice showed no difference from wildtype littermates on both METH-induced conditioned place preference and in METH-induced locomotor activity (1 mg/kg METH). These results demonstrate that elevated VMAT2 protects against METH toxicity without enhancing the rewarding effects of the drug. Since the VMAT2-HI mice are protected from METH despite higher basal dopamine levels, this study suggests that METH toxicity depends more on the proper compartmentalization of synaptic dopamine than on the absolute amount of dopamine in the brain. PMID:25746685

  7. HLA-A2-Restricted Protection against Lethal Lymphocytic Choriomeningitis▿ †

    PubMed Central

    Botten, Jason; Whitton, J. Lindsay; Barrowman, Polly; Sidney, John; Whitmire, Jason K.; Alexander, Jeff; Ting, Joey P. C.; Bui, Huynh-Hoa; Sette, Alessandro; Buchmeier, Michael J.

    2007-01-01

    The consequences of human lymphocytic choriomeningitis virus (LCMV) infection can be severe, including aseptic meningitis in immunocompetent individuals, hydrocephalus or chorioretinitis in fetal infection, or a highly lethal outcome in immunosuppressed individuals. In murine models of LCMV infection, CD8+ T cells play a primary role in providing protective immunity, and there is evidence that cellular immunity may also be important in related arenavirus infections in humans. For this reason, we sought to identify HLA-A2 supertype-restricted epitopes from the LCMV proteome and evaluate them as vaccine determinants in HLA transgenic mice. We identified four HLA-A*0201-restricted peptides—nucleoprotein NP69-77, glycoprotein precursor GPC10-18, GPC447-455, and zinc-binding protein Z49-58—that displayed high-affinity binding (≤275 nM) to HLA-A*0201, induced CD8+ T-cell responses of high functional avidity in HLA-A*0201 transgenic mice, and were naturally processed from native LCMV antigens in HLA-restricted human antigen presenting cells. One of the epitopes (GPC447-455), after peptide immunization of HLA-A*0201 mice, induced CD8+ T cells capable of killing peptide-pulsed HLA-A*0201-restricted target cells in vivo and protected mice against lethal intracranial challenge with LCMV. PMID:17166907

  8. Internal Trehalose Protects Endocytosis from Inhibition by Ethanol in Saccharomyces cerevisiae

    PubMed Central

    Lucero, P.; Peñalver, E.; Moreno, E.; Lagunas, R.

    2000-01-01

    Endocytosis in Saccharomyces cerevisiae is inhibited by concentrations of ethanol of 2 to 6% (vol/vol), which are lower than concentrations commonly present in its natural habitats. In spite of this inhibition, endocytosis takes place under enological conditions when high concentrations of ethanol are present. Therefore, it seems that yeast has developed some means to circumvent the inhibition. In this work we have investigated this possibility. We identified two stress conditions under which endocytosis was resistant to inhibition by ethanol: fermentation during nitrogen starvation and growth on nonfermentable substrates. Under these conditions, yeast accumulates stress protectors, primarily trehalose and Hsp104, a protein required for yeast to survive ethanol stress. We found the following. (i) The appearance of ethanol resistance was accompanied by trehalose accumulation. (ii) Mutant cells unable to synthesize trehalose also were unable to develop resistance. (iii) Mutant cells that accumulated trehalose during growth on sugars were resistant to ethanol even under this nonstressing condition. (iv) Mutant cells unable to synthesize Hsp104 were able to develop resistance. We conclude that trehalose is the major factor in the protection of endocytosis from ethanol. Our results suggest another important physiological role for trehalose in yeast. PMID:11010898

  9. Corosolic acid inhibits the proliferation of glomerular mesangial cells and protects against diabetic renal damage

    PubMed Central

    Li, Xiao-Qiang; Tian, Wen; Liu, Xiao-Xiao; Zhang, Kai; Huo, Jun-Cheng; Liu, Wen-Juan; Li, Ping; Xiao, Xiong; Zhao, Ming-Gao; Cao, Wei

    2016-01-01

    Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus (DM). This study aimed to explore the effects of corosolic acid (CA) on the renal damage of DM and the mechanisms behind these effects. The renoprotective effect of CA was investigated in type 1 diabetic rats and db/db mice. The kidneys and glomerular mesangial cells (GMCs) were used to study the proliferation of GMCs by immunostaining and MTT assay. Further immunoblotting, siRNA, qPCR analysis, and detecting of NADPH oxidase activity and reactive oxygen species (ROS) generation were performed to explore relevant molecular mechanisms. In CA-treated diabetic animals, diabetes-induced albuminuria, increased serum creatinine and blood urea nitrogen were significantly attenuated, and glomerular hypertrophy, mesangial expansion and fibrosis were ameliorated. Furthermore, CA significantly inhibited proliferation of GMCs and phosphorylation of ERK1/2 and p38 MAPK in both diabetic animals and high glucose (HG)-induced GMCs. CA also normalized Δψm and inhibited HG-induced NADPH oxidase activity, ROS generation and NOX4, NOX2, p22phox and p47phox expression. More importantly, CA inhibited GMC proliferation mediated by NADPH/ERK1/2 and p38 MAPK signaling pathways. These findings suggest that CA exert the protective effect on DN by anti-proliferation resulted from inhibition of p38 MAPK- and NADPH-mediated inactivation of ERK1/2. PMID:27229751

  10. Kaurane diterpenes protect against apoptosis and inhibition of phagocytosis in activated macrophages.

    PubMed

    de las Heras, B; Hortelano, S; Girón, N; Bermejo, P; Rodríguez, B; Boscá, L

    2007-09-01

    The kaurane diterpenes foliol and linearol are inhibitors of the activation of nuclear factor kappaB, a transcription factor involved in the inflammatory response. Effects of these diterpenes on apoptosis and phagocytosis have been analysed in cultured peritoneal macrophages and in the mouse macrophage cell line, RAW 264.7. Macrophages were maintained in culture and activated with pro-inflammatory stimuli in the absence or presence of diterpenes. Apoptosis and the phagocytosis in these cells under these conditions were determined. Incubation of macrophages with a mixture of bacterial lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma) induced apoptosis through a NO-dependent pathway, an effect significantly inhibited by foliol and linearol in the low muM range, without cytotoxic effects. Apoptosis in macrophages induced by NO donors was also inhibited. The diterpenes prevented apoptosis through a mechanism compatible with the inhibition of caspase-3 activation, release of cytochrome c to the cytosol and p53 overexpression, as well as an alteration in the levels of proteins of the Bcl-2 family, in particular, the levels of Bax. Cleavage of poly(ADP-ribose) polymerase, a well-established caspase substrate, was reduced by these diterpenes. Treatment of cells with foliol and linearol decreased phagocytosis of zymosan bioparticles by RAW 264.7 cells and to a greater extent by peritoneal macrophages. Both diterpenes protected macrophages from apoptosis and inhibited phagocytosis, resulting in a paradoxical control of macrophage function, as viability was prolonged but inflammatory and phagocytic functions were impaired.

  11. C/EBPβ knockdown protects cardiomyocytes from hypertrophy via inhibition of p65-NFκB.

    PubMed

    Zou, Jian; Li, Hong; Chen, Xi; Zeng, Siyu; Ye, Jiantao; Zhou, Changhua; Liu, Min; Zhang, Luankun; Yu, Na; Gan, Xiaohong; Zhou, Houfeng; Xian, Zhiwei; Chen, Shaorui; Liu, Peiqing

    2014-06-05

    C/EBPβ, a member of the bHLH gene family of DNA-binding transcription factors, has been indicated as a central signal in physiologic hypertrophy. However, the role of C/EBPβ in pathological cardiac hypertrophy remains to be elucidated. In this study, we revealed that C/EBPβ is involved in cardiac hypertrophy, the expression of C/EBPβ were significantly increased in response to hypertrophic stimulation in vitro and in vivo. C/EBPβ knockdown inhibited PE-induced cardiac hypertrophy, and diminished the nuclear translocation and DNA binding activity of p65-NFκB. These results suggested that C/EBPβ knockdown protected cardiomyocytes from hypertrophy, which may be attributed to inhibition of NFκB-dependent transcriptional activity. These findings shed new light on the understanding of C/EBPβ-related cardiomyopathy, and suggest the potential application of C/EBPβ inhibitors in cardiac hypertrophy.

  12. Chloroquine Inhibits HMGB1 Inflammatory Signaling and Protects Mice from Lethal Sepsis

    PubMed Central

    Yang, Minghua; Cao, Lizhi; Xie, Min; Yu, Yan; Kang, Rui; Yang, Liangchun; Zhao, Mingyi; Tang, Daolin

    2013-01-01

    Sepsis is caused by an overwhelming immune response to bacterial infection. The discovery of high mobility group box 1 (HMGB1) as a late mediator of lethal sepsis has prompted investigation into the development of new therapeutics which specifically target this protein. Here, we show that chloroquine, an anti-malarial drug, prevents lethality in mice with established endotoxemia or sepsis. This effect is still observed even if administration of chloroquine is delayed. The protective effects of chloroquine were mediated through inhibition of HMGB1 release in macrophages, monocytes, and endothelial cells, thereby preventing its cytokine-like activities. As an inhibitor of autophagy, chloroquine specifically inhibited HMGB1-induced Iκ-B degradation and NF-κB activation. These findings define a novel mechanism for the anti-inflammatory effects of chloroquine and also suggest a new potential clinical use for this drug in the setting of sepsis. PMID:23707973

  13. Vitamin B12 offers neuronal cell protection by inhibiting Aβ-42 amyloid fibrillation.

    PubMed

    Alam, Parvez; Siddiqi, Mohammad Khursheed; Chaturvedi, Sumit Kumar; Zaman, Masihuz; Khan, Rizwan Hasan

    2017-03-04

    Protein misfolding and aggregation has been implicated as the cause of more than 20 diseases in humans such as Alzheimer's and Parkinson's and systemic amyloidosis. Retardation of Aβ- 42 aggregation is considered as a promising and challenging strategy for developing effective therapeutics against Alzheimer's disease. Herein, we demonstrated the effect of vitamin B12 (VB) on inhibiting amyloid formation by employing ThT fluorescence assay, circular dichroism, ANS fluorescence assay, dynamic light scattering measurements and transmission electron microscopy and cell viability assay. Our results demonstrate that vitamin B12 (VB), inhibits Aβ- 42 aggregation in a concentration dependent manner. Further VB also provide protection against amyloid induced cytotoxicity in human neuronal cell line. This study points towards a promising strategy to combat Aβ- 42 aggregation and may have broader implication for targeting other neurological disorders whose distinct hallmark is also amyloid formation.

  14. P2X7 receptor inhibition protects against ischemic acute kidney injury in mice.

    PubMed

    Yan, Yanli; Bai, Jianwen; Zhou, Xiaoxu; Tang, Jinhua; Jiang, Chunming; Tolbert, Evelyn; Bayliss, George; Gong, Rujun; Zhao, Ting C; Zhuang, Shougang

    2015-03-15

    Activation of the purinergic P2X7 receptor (P2X7R) has been associated with the development of experimental nephritis and diabetic and hypertensive nephropathy. However, its role in acute kidney injury (AKI) remains unknown. In this study, we examined the effects of P2X7R inhibition in a murine model of ischemia-reperfusion (I/R)-induced AKI using A438079, a selective inhibitor of P2X7R. At 24 h after I/R, mice developed renal dysfunction and renal tubular damage, which was accompanied by elevated expression of P2X7R. Early administration of A438079 immediately or 6 h after the onset of reperfusion protected against renal dysfunction and attenuated kidney damage whereas delayed administration of A438079 at 24 h after restoration of perfusion had no protective effects. The protective actions of A438079 were associated with inhibition of renal tubule injury and cell death and suppression of renal expression of monocyte chemotactic protein-1 and regulated upon expression normal T cell expressed and secreted (RANTES). Moreover, I/R injury led to an increase in phosphorylation (activation) of extracellular signal-regulated kinases 1/2 in the kidney; treatment with A438079 diminished this response. Collectively, these results indicate that early P2X7R inhibition is effective against renal tubule injury and proinflammatory response after I/R injury and suggest that targeting P2X7R may be a promising therapeutic strategy for treatment of AKI.

  15. Inhibited ethylene and propylene glycols for corrosion and freeze protection in water-based HVAC systems

    SciTech Connect

    Roo, A.M. de; Lee, B.W.

    1997-12-31

    Industrially inhibited ethylene and propylene glycols are used extensively to provide protection against equipment damage due to corrosion and freezing. This paper will describe the proper use of these glycols, including system preparation, fluid installation, and fluid maintenance. The impact of the use of these glycols on the operation of the system is discussed along with methods for overcoming any declines in heat transfer. From this discussion, it will become clear why automotive antifreeze formulations should not be used in heating, ventilating, and airconditioning (HVAC) systems. Also included are data on the physical properties of aqueous solutions of ethylene and propylene glycol, the concept of burst vs. freeze protection, typical results of corrosion tests, and methods to use to monitor the fluid for each application.

  16. Bacopa monnieri-Induced Protective Autophagy Inhibits Benzo[a]pyrene-Mediated Apoptosis.

    PubMed

    Das, Durgesh Nandini; Naik, Prajna Paramita; Nayak, Aditi; Panda, Prashanta Kumar; Mukhopadhyay, Subhadip; Sinha, Niharika; Bhutia, Sujit K

    2016-11-01

    Benzo[a]pyrene (B[a]P) is capable of inducing oxidative stress and cellular injuries leading to cell death and associates with a significant risk of cancer development. Prevention of B[a]P-induced cellular toxicity with herbal compound through regulation of mitochondrial oxidative stress might protect cell death and have therapeutic benefit to human health. In this study, we demonstrated the cytoprotective role of Bacopa monnieri (BM) against B[a]P-induced apoptosis through autophagy induction. Pretreatment with BM rescued the reduction in cell viability in B[a]P-treated human keratinocytes (HaCaT) cells indicating the cytoprotective potential of BM against B[a]P. Moreover, BM was found to inhibit B[a]P-mediated reactive oxygen species (ROS)-induced apoptosis activation in HaCaT cells. Furthermore, BM was found to preserve mitochondrial membrane potential and inhibited release of cytochrome c in B[a]P-treated HaCaT cells. Bacopa monnieri induced protective autophagy; we knocked down Beclin-1, and data showed that BM was unable to protect from B[a]P-induced mitochondrial ROS-mediated apoptosis in Beclin-1-deficient HaCaT cells. Moreover, we established that B[a]P-induced damaged mitochondria were found to colocalize and degraded within autolysosomes in order to protect HaCaT cells from mitochondrial injury. In conclusion, B[a]P-induced apoptosis was rescued by BM treatment and provided cytoprotection through Beclin-1-dependent autophagy activation. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Inhibition of Granzyme B by PI-9 protects prostate cancer cells from apoptosis

    PubMed Central

    Ray, Manisha; Hostetter, Daniel R.; Loeb, Carly RK; Simko, Jeffry; Craik, Charles S.

    2012-01-01

    Background In order for tumors to grow and proliferate, they must avoid recognition by immune cells and subsequent death by apoptosis. Granzyme B, a protease located in natural killer cells, initiates apoptosis in target cells. Inhibition of Granzyme B by PI-9, its natural inhibitor, can prevent apoptosis. Here we investigate whether PI-9 protects prostate cancer cells from apoptosis. Methods The expression of PI-9 was quantified by qPCR in several prostate cancer cell lines, and Granzyme B activity was tested in each cell line. PI-9 was overexpressed in LNCaP cells, which lack endogenous PI-9. Apoptosis was induced by natural killer cells in LNCaP cells that either contained or lacked PI-9, and the percent cell death in was quantified. Lastly, PI-9 levels were examined by qPCR and immunohistochemistry in prostate tumor tissue. Results Prostate cancer cell lines that expressed PI-9 could inhibit Granzyme B. Overexpression of PI-9 protected LNCaP cells from natural killer cell-mediated apoptosis. Examination of the levels of PI-9 in tissue from prostate tumors showed that PI-9 could be upregulated in low grade tumors and stochastically dysregulated in high grade tumors. Additionally, PI-9 is found consistently in high grade prostatic intraepithelial neoplasia and atrophic lesions. Conclusions These results indicate that overexpression of PI-9 can protect prostate cancer cells from apoptosis, and this effect may occur in human prostate tumors. These findings imply that early prostatic inflammation may trigger this increase in PI-9. This suggests that PI-9 upregulation is needed early in tumor progression, before additional protective mechanisms are in place. PMID:21919028

  18. Pre-synaptic adenosine A2A receptors control cannabinoid CB1 receptor-mediated inhibition of striatal glutamatergic neurotransmission.

    PubMed

    Martire, Alberto; Tebano, Maria Teresa; Chiodi, Valentina; Ferreira, Samira G; Cunha, Rodrigo A; Köfalvi, Attila; Popoli, Patrizia

    2011-01-01

    An interaction between adenosine A(2A) receptors (A(2A) Rs) and cannabinoid CB(1) receptors (CB(1) Rs) has been consistently reported to occur in the striatum, although the precise mechanisms are not completely understood. As both receptors control striatal glutamatergic transmission, we now probed the putative interaction between pre-synaptic CB(1) R and A(2A) R in the striatum. In extracellular field potentials recordings in corticostriatal slices from Wistar rats, A(2A) R activation by CGS21680 inhibited CB(1) R-mediated effects (depression of synaptic response and increase in paired-pulse facilitation). Moreover, in superfused rat striatal nerve terminals, A(2A) R activation prevented, while A(2A) R inhibition facilitated, the CB(1) R-mediated inhibition of 4-aminopyridine-evoked glutamate release. In summary, the present study provides converging neurochemical and electrophysiological support for the occurrence of a tight control of CB(1) R function by A(2A) Rs in glutamatergic terminals of the striatum. In view of the key role of glutamate to trigger the recruitment of striatal circuits, this pre-synaptic interaction between CB(1) R and A(2A) R may be of relevance for the pathogenesis and the treatment of neuropsychiatric disorders affecting the basal ganglia.

  19. Nicousamide protects kidney podocyte by inhibiting the TGFβ receptor II phosphorylation and AGE-RAGE signaling

    PubMed Central

    Zhang, Sen; Wang, Dongjie; Xue, Nina; Lai, Fangfang; Ji, Ming; Jin, Jing; Chen, Xiaoguang

    2017-01-01

    Nicousamide, a clinical phase II renal protective new drug, has been demonstrated to have renal protective effect on diabetic nephropathy (DN) by experimental animal model. Its known molecular mechanisms include AGE formation blocking and moderately decreasing the blood pressure. Nicousamide shows potential on attenuating albuminuria, thereby suggests it might have protective effect on podocytes. The aim of present study was to investigate whether nicousamide could protect integrity of podocytes, and further its protection mechanisms. Sprague-Dawley (SD) rats were induced to DN by streptozotocin, and nicousamide (20 and 40 mg/kg) was orally administrated for 20 weeks. Every five weeks, the albuminuria was measured, and renal pathology was evaluated at the end of experiment. Real-time PCR and immunofluorescence were used to test expression of podocyte marker nephrin, CD2AP and podocine in rat kidney tissues. Western blot was used to test the activation and phosphorylation of TGFβ1-smad signaling pathway. surface plasmon resonance (SPR) technology was used to analyze whether nicousamide can interact with TGFβ1 receptor II (TGFβ RII) and receptor for advanced glycation endproducts (RAGE). Results demonstrate that nicousamide significantly reduces albuminuria and ameliorate the glomerulosclerosis in DN rats. RT-PCR and immunofluorescence demonstrate that nicousamide can increase the expression of podocyte markers and keep podocyte effacement. Phosphorylation of TGFβ RII and smad2 in rat kidney was inhibited by nicousamide dose dependently. SPR demonstrate that nicousamide have strong binding capability with hRAGE with Kd approximate 6 μM. These results indicate a protective effect of nicousamide against podocyte injury, and this effect might contribute from suppression of TGFβ-involved fibrosis and AGE-RAGE signaling activation. PMID:28123638

  20. Inhibition of Adenylyl Cyclase Type 5 Increases Longevity and Healthful Aging through Oxidative Stress Protection

    PubMed Central

    Vatner, Stephen F.; Pachon, Ronald E.; Vatner, Dorothy E.

    2015-01-01

    Mice with disruption of adenylyl cyclase type 5 (AC5 knockout, KO) live a third longer than littermates. The mechanism, in part, involves the MEK/ERK pathway, which in turn is related to protection against oxidative stress. The AC5 KO model also protects against diabetes, obesity, and the cardiomyopathy induced by aging, diabetes, and cardiac stress and also demonstrates improved exercise capacity. All of these salutary features are also mediated, in part, by oxidative stress protection. For example, chronic beta adrenergic receptor stimulation induced cardiomyopathy was rescued by AC5 KO. Conversely, in AC5 transgenic (Tg) mice, where AC5 is overexpressed in the heart, the cardiomyopathy was exacerbated and was rescued by enhancing oxidative stress resistance. Thus, the AC5 KO model, which resists oxidative stress, is uniquely designed for clinical translation, since it not only increases longevity and exercise, but also protects against diabetes, obesity, and cardiomyopathy. Importantly, inhibition of AC5's action to prolong longevity and enhance healthful aging, as well as its mechanism through resistance to oxidative stress, is unique among all of the nine AC isoforms. PMID:25945149

  1. Insulin Protects Pancreatic Acinar Cells from Cytosolic Calcium Overload and Inhibition of Plasma Membrane Calcium Pump*

    PubMed Central

    Mankad, Parini; James, Andrew; Siriwardena, Ajith K.; Elliott, Austin C.; Bruce, Jason I. E.

    2012-01-01

    Acute pancreatitis is a serious and sometimes fatal inflammatory disease of the pancreas without any reliable treatment or imminent cure. In recent years, impaired metabolism and cytosolic Ca2+ ([Ca2+]i) overload in pancreatic acinar cells have been implicated as the cardinal pathological events common to most forms of pancreatitis, regardless of the precise causative factor. Therefore, restoration of metabolism and protection against cytosolic Ca2+ overload likely represent key therapeutic untapped strategies for the treatment of this disease. The plasma membrane Ca2+-ATPase (PMCA) provides a final common path for cells to “defend” [Ca2+]i during cellular injury. In this paper, we use fluorescence imaging to show for the first time that insulin treatment, which is protective in animal models and clinical studies of human pancreatitis, directly protects pancreatic acinar cells from oxidant-induced cytosolic Ca2+ overload and inhibition of the PMCA. This protection was independent of oxidative stress or mitochondrial membrane potential but appeared to involve the activation of Akt and an acute metabolic switch from mitochondrial to predominantly glycolytic metabolism. This switch to glycolysis appeared to be sufficient to maintain cellular ATP and thus PMCA activity, thereby preventing Ca2+ overload, even in the face of impaired mitochondrial function. PMID:22128146

  2. Environmentally persistent free radical-containing particulate matter competitively inhibits metabolism by cytochrome P450 1A2.

    PubMed

    Reed, James R; dela Cruz, Albert Leo N; Lomnicki, Slawo M; Backes, Wayne L

    2015-12-01

    Combustion processes generate different types of particulate matter (PM) that can have deleterious effects on the pulmonary and cardiovascular systems. Environmentally persistent free radicals (EPFRs) represent a type of particulate matter that is generated after combustion of environmental wastes in the presence of redox-active metals and aromatic hydrocarbons. Cytochromes P450 (P450/CYP) are membrane-bound enzymes that are essential for the phase I metabolism of most lipophilic xenobiotics. The EPFR formed by chemisorption of 2-monochlorophenol to silica containing 5% copper oxide (MCP230) has been shown to generally inhibit the activities of different forms of P450s without affecting those of cytochrome P450 reductase and heme oxygenase-1. The mechanism of inhibition of rat liver microsomal CYP2D2 and purified rabbit CYP2B4 by MCP230 has been shown previously to be noncompetitive with respect to substrate. In this study, MCP230 was shown to competitively inhibit metabolism of 7-benzyl-4-trifluoromethylcoumarin and 7-ethoxyresorufin by the purified, reconstituted rabbit CYP1A2. MCP230 is at least 5- and 50-fold more potent as an inhibitor of CYP1A2 than silica containing 5% copper oxide and silica, respectively. Thus, even though PM generally inhibit multiple forms of P450, PM interacts differently with the forms of P450 resulting in different mechanisms of inhibition. P450s function as oligomeric complexes within the membrane. We also determined the mechanism by which PM inhibited metabolism by the mixed CYP1A2-CYP2B4 complex and found that the mechanism was purely competitive suggesting that the CYP2B4 is dramatically inhibited when bound to CYP1A2. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Environmentally persistent free radical-containing particulate matter competitively inhibits metabolism by cytochrome P450 1A2

    PubMed Central

    Reed, James R.; dela Cruz, Albert Leo N.; Lomnicki, Slawo M.; Backes, Wayne L.

    2015-01-01

    Combustion processes generate different types of particulate matter (PM) that can have deleterious effects on the pulmonary and cardiovascular systems. Environmentally persistent free radicals (EPFRs) represent a type of particulate matter that is generated after combustion of environmental wastes in the presence of redox-active metals and aromatic hydrocarbons. Cytochromes P450 (P450/CYP) are membrane-bound enzymes that are essential for the phase I metabolism of most lipophilic xenobiotics. The EPFR formed by chemisorption of 2-monochlorophenol to silica containing 5% copper oxide (MCP230) has been shown to generally inhibit the activities of different forms of P450s without affecting those of cytochrome P450 reductase and heme oxygenase-1. The mechanism of inhibition of rat liver microsomal CYP2D2 and purified rabbit CYP2B4 by MCP230 has been shown previously to be noncompetitive with respect to substrate. In this study, MCP230 was shown to competitively inhibit metabolism of 7-benzyl-4-trifluoromethylcoumarin and 7-ethoxyresorufin by the purified, reconstituted rabbit CYP1A2. MCP230 is at least 5- and 50-fold more potent as an inhibitor of CYP1A2 than silica containing 5% copper oxide and silica, respectively. Thus, even though PM generally inhibit multiple forms of P450, PM interacts differently with the forms of P450 resulting in different mechanisms of inhibition. P450s function as oligomeric complexes within the membrane. We also determined the mechanism by which PM inhibited metabolism by the mixed CYP1A2-CYP2B4 complex and found that the mechanism was purely competitive suggesting that the CYP2B4 is dramatically inhibited when bound to CYP1A2. PMID:26423927

  4. Alpha B-Crystallin Protects Rat Articular Chondrocytes against Casein Kinase II Inhibition-Induced Apoptosis.

    PubMed

    Lee, Sung Won; Rho, Jee Hyun; Lee, Sang Yeob; Yoo, Seung Hee; Kim, Hye Young; Chung, Won Tae; Yoo, Young Hyun

    2016-01-01

    Although alpha (α)B-crystallin is expressed in articular chondrocytes, little is known about its role in these cells. Protein kinase casein kinase 2 (CK2) inhibition induces articular chondrocyte death. The present study examines whether αB-crystallin exerts anti-apoptotic activity in articular chondrocytes. Primary rat articular chondrocytes were isolated from knee joint slices. Cells were treated with CK2 inhibitors with or without αB-crystallin siRNA. To examine whether the silencing of αB-crystallin sensitizes rat articular chondrocytes to CK2 inhibition-induced apoptosis, we assessed apoptosis by performing viability assays, mitochondrial membrane potential measurements, flow cytometry, nuclear morphology observations, and western blot analysis. To investigate the mechanism by which αB-crystallin modulates the extent of CK2 inhibition-mediated chondrocyte death, we utilized confocal microscopy to observe the subcellular location of αB-crystallin and its phosphorylated forms and performed a co-immunoprecipitation assay to observe the interaction between αB-crystallin and CK2. Immunochemistry was employed to examine αB-crystallin expression in cartilage obtained from rats with experimentally induced osteoarthritis (OA). Our results demonstrated that silencing of αB-crystallin sensitized rat articular chondrocytes to CK2 inhibitor-induced apoptosis. Furthermore, CK2 inhibition modulated the expression and subcellular localization of αB-crystallin and its phosphorylated forms and dissociated αB-crystallin from CK2. The population of rat articular chondrocytes expressing αB-crystallin and its phosphorylated forms was reduced in an experimentally induced rat model of OA. In summary, αB-crystallin protects rat articular chondrocytes against CK2 inhibition-induced apoptosis. αB-crystallin may represent a suitable target for pharmacological interventions to prevent OA.

  5. Alpha B-Crystallin Protects Rat Articular Chondrocytes against Casein Kinase II Inhibition-Induced Apoptosis

    PubMed Central

    Rho, Jee Hyun; Lee, Sang Yeob; Yoo, Seung Hee; Kim, Hye Young; Chung, Won Tae; Yoo, Young Hyun

    2016-01-01

    Although alpha (α)B-crystallin is expressed in articular chondrocytes, little is known about its role in these cells. Protein kinase casein kinase 2 (CK2) inhibition induces articular chondrocyte death. The present study examines whether αB-crystallin exerts anti-apoptotic activity in articular chondrocytes. Primary rat articular chondrocytes were isolated from knee joint slices. Cells were treated with CK2 inhibitors with or without αB-crystallin siRNA. To examine whether the silencing of αB-crystallin sensitizes rat articular chondrocytes to CK2 inhibition-induced apoptosis, we assessed apoptosis by performing viability assays, mitochondrial membrane potential measurements, flow cytometry, nuclear morphology observations, and western blot analysis. To investigate the mechanism by which αB-crystallin modulates the extent of CK2 inhibition-mediated chondrocyte death, we utilized confocal microscopy to observe the subcellular location of αB-crystallin and its phosphorylated forms and performed a co-immunoprecipitation assay to observe the interaction between αB-crystallin and CK2. Immunochemistry was employed to examine αB-crystallin expression in cartilage obtained from rats with experimentally induced osteoarthritis (OA). Our results demonstrated that silencing of αB-crystallin sensitized rat articular chondrocytes to CK2 inhibitor-induced apoptosis. Furthermore, CK2 inhibition modulated the expression and subcellular localization of αB-crystallin and its phosphorylated forms and dissociated αB-crystallin from CK2. The population of rat articular chondrocytes expressing αB-crystallin and its phosphorylated forms was reduced in an experimentally induced rat model of OA. In summary, αB-crystallin protects rat articular chondrocytes against CK2 inhibition-induced apoptosis. αB-crystallin may represent a suitable target for pharmacological interventions to prevent OA. PMID:27851782

  6. NOX2 Activation of Natural Killer T Cells Is Blocked by the Adenosine A2A Receptor to Inhibit Lung Ischemia-Reperfusion Injury.

    PubMed

    Sharma, Ashish K; LaPar, Damien J; Stone, Matthew L; Zhao, Yunge; Mehta, Christopher K; Kron, Irving L; Laubach, Victor E

    2016-05-01

    Ischemia-reperfusion (IR) injury after lung transplantation, which affects both short- and long-term allograft survival, involves activation of NADPH oxidase 2 (NOX2) and activation of invariant natural killer T (iNKT) cells to produce IL-17. Adenosine A2A receptor (A2AR) agonists are known to potently attenuate lung IR injury and IL-17 production. However, mechanisms for iNKT cell activation after IR and A2AR agonist-mediated protection remain unclear. We tested the hypothesis that NOX2 mediates IL-17 production by iNKT cells after IR and that A2AR agonism prevents IR injury by blocking NOX2 activation in iNKT cells. An in vivo murine hilar ligation model of IR injury was used, in which left lungs underwent 1 hour of ischemia and 2 hours of reperfusion. Adoptive transfer of iNKT cells from p47(phox-/-) or NOX2(-/-) mice to Jα18(-/-) (iNKT cell-deficient) mice significantly attenuated lung IR injury and IL-17 production. Treatment with an A2AR agonist attenuated IR injury and IL-17 production in wild-type (WT) mice and in Jα18(-/-) mice reconstituted with WT, but not A2AR(-/-), iNKT cells. Furthermore, the A2AR agonist prevented IL-17 production by murine and human iNKT cells after acute hypoxia-reoxygenation by blocking p47(phox) phosphorylation, a critical step for NOX2 activation. NOX2 plays a key role in inducing iNKT cell-mediated IL-17 production and subsequent lung injury after IR. A primary mechanism for A2AR agonist-mediated protection entails inhibition of NOX2 in iNKT cells. Therefore, agonism of A2ARs on iNKT cells may be a novel therapeutic strategy to prevent primary graft dysfunction after lung transplantation.

  7. Pharmacological TLR4 Inhibition Protects against Acute and Chronic Fat-Induced Insulin Resistance in Rats

    PubMed Central

    Zhang, Ning; Liang, Hanyu; Farese, Robert V.; Li, Ji

    2015-01-01

    Aims To evaluate whether pharmacological TLR4 inhibition protects against acute and chronic fat-induced insulin resistance in rats. Materials and Methods For the acute experiment, rats received a TLR4 inhibitor [TAK-242 or E5564 (2x5 mg/kg i.v. bolus)] or vehicle, and an 8-h Intralipid (20%, 8.5 mg/kg/min) or saline infusion, followed by a two-step hyperinsulinemic-euglycemic clamp. For the chronic experiment, rats were subcutaneously implanted with a slow-release pellet of TAK-242 (1.5 mg/d) or placebo. Rats then received a high fat diet (HFD) or a low fat control diet (LFD) for 10 weeks, followed by a two-step insulin clamp. Results Acute experiment; the lipid-induced reduction (18%) in insulin-stimulated glucose disposal (Rd) was attenuated by TAK-242 and E5564 (the effect of E5564 was more robust), suggesting improved peripheral insulin action. Insulin was able to suppress hepatic glucose production (HGP) in saline- but not lipid-treated rats. TAK-242, but not E5564, partially restored this effect, suggesting improved HGP. Chronic experiment; insulin-stimulated Rd was reduced ~30% by the HFD, but completely restored by TAK-242. Insulin could not suppress HGP in rats fed a HFD and TAK-242 had no effect on HGP. Conclusions Pharmacological TLR4 inhibition provides partial protection against acute and chronic fat-induced insulin resistance in vivo. PMID:26196892

  8. Ginseng Protects Against Respiratory Syncytial Virus by Modulating Multiple Immune Cells and Inhibiting Viral Replication

    PubMed Central

    Lee, Jong Seok; Lee, Yu-Na; Lee, Young-Tae; Hwang, Hye Suk; Kim, Ki-Hye; Ko, Eun-Ju; Kim, Min-Chul; Kang, Sang-Moo

    2015-01-01

    Ginseng has been used in humans for thousands of years but its effects on viral infection have not been well understood. We investigated the effects of red ginseng extract (RGE) on respiratory syncytial virus (RSV) infection using in vitro cell culture and in vivo mouse models. RGE partially protected human epithelial (HEp2) cells from RSV-induced cell death and viral replication. In addition, RGE significantly inhibited the production of RSV-induced pro-inflammatory cytokine (TNF-α) in murine dendritic and macrophage-like cells. More importantly, RGE intranasal pre-treatment prevented loss of mouse body weight after RSV infection. RGE treatment improved lung viral clearance and enhanced the production of interferon (IFN-γ) in bronchoalveolar lavage cells upon RSV infection of mice. Analysis of cellular phenotypes in bronchoalveolar lavage fluids showed that RGE treatment increased the populations of CD8+ T cells and CD11c+ dendritic cells upon RSV infection of mice. Taken together, these results provide evidence that ginseng has protective effects against RSV infection through multiple mechanisms, which include improving cell survival, partial inhibition of viral replication and modulation of cytokine production and types of immune cells migrating into the lung. PMID:25658239

  9. Semicarbazone EGA Inhibits Uptake of Diphtheria Toxin into Human Cells and Protects Cells from Intoxication

    PubMed Central

    Schnell, Leonie; Mittler, Ann-Katrin; Mattarei, Andrea; Tehran, Domenico Azarnia; Montecucco, Cesare; Barth, Holger

    2016-01-01

    Diphtheria toxin is a single-chain protein toxin that invades human cells by receptor-mediated endocytosis. In acidic endosomes, its translocation domain inserts into endosomal membranes and facilitates the transport of the catalytic domain (DTA) from endosomal lumen into the host cell cytosol. Here, DTA ADP-ribosylates elongation factor 2 inhibits protein synthesis and leads to cell death. The compound 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA) has been previously shown to protect cells from various bacterial protein toxins which deliver their enzymatic subunits from acidic endosomes to the cytosol, including Bacillus anthracis lethal toxin and the binary clostridial actin ADP-ribosylating toxins C2, iota and Clostridium difficile binary toxin (CDT). Here, we demonstrate that EGA also protects human cells from diphtheria toxin by inhibiting the pH-dependent translocation of DTA across cell membranes. The results suggest that EGA might serve for treatment and/or prevention of the severe disease diphtheria. PMID:27428999

  10. Inhibition of Cytochrome P450 1A2-Mediated Metabolism and Production of Reactive Oxygen Species by Heme Oxygenase-1 in Rat Liver Microsomes

    PubMed Central

    Reed, James R.; Cawley, George F.; Backes, Wayne L.

    2011-01-01

    Heme oxygenase-1 (HO-1) is induced in most cell types by many forms of environmental stress and is believed to play a protective role in cells exposed to oxidative stress. Metabolism by cytochromes P450 (P450) is highly inefficient as the oxidation of substrate is associated with the production of varying proportions of hydrogen peroxide and/or superoxide. This study tests the hypothesis that heme oxygenase-1 (HO-1) plays a protective role against oxidative stress by competing with P450 for binding to the common redox partner, the NADPH P450 reductase (CPR) and in the process, diminishing P450 metabolism and the associated production of reactive oxygen species (ROS). Liver microsomes were isolated from uninduced rats and rats that were treated with cadmium and/or β-napthoflavone (BNF) to induce HO-1 and/or CYP1A2. HO-1 induction was associated with slower rates of metabolism of the CYP1A2-specific substrate, 7-ethoxyresorufin. Furthermore, HO-1 induction also was associated with slower rates of hydrogen peroxide and hydroxyl radical production by microsomes from rats induced for CYP1A2. The inhibition associated with HO-1 induction was not dependent on the addition of heme to the microsomal incubations. The effects of HO-1 induction were less dramatic in the absence of substrate for CYP1A2, suggesting that the enzyme was more effective in inhibiting the CYP1A2-related activity than the CPR-related production of superoxide (that dismutates to form hydrogen peroxide). PMID:20942796

  11. Cigarette Smoking Attenuates Kidney Protection by Angiotensin-Converting Enzyme Inhibition in Nondiabetic Chronic Kidney Disease.

    PubMed

    Roehm, Bethany; Simoni, Jan; Pruszynski, Jessica; Wesson, Donald E

    2017-09-21

    Cigarette smoking exacerbates the estimated glomerular filtration rate (eGFR) decline in nondiabetic chronic kidney disease (CKD) despite the kidney protection that is achieved by angiotensin converting enzyme inhibition (ACEI). Whether smoking cessation restores ACEI-related kidney protection is not known. This 5-year, prospective, prevention trial recruited 108 smokers and 108 nonsmokers with stage-2 nondiabetic CKD with primary hypertension and urine albumin-to-creatinine ratio (Ualb) >200 mg/g. All smokers underwent smoking cessation intervention programs. Blood pressure was reduced in all participants toward achieving a goal of <130 mm Hg with regimens including ACEI. The primary outcome was eGFR change, and secondary outcomes included Ualb and urine levels of angiotensinogen (UATG), a surrogate for kidney angiotensin II (AII) levels, and isoprostane 8-isoprostaglandin F2α (U8-iso), an indicator of oxidative stress. One-year Ualb was lower than baseline in nonsmokers but not in either smoking group, supporting greater ACEI-related kidney protection in nonsmokers than smokers. Higher Ualb at 1 year in continued smokers was associated with higher UATG and higher U8-iso, consistent with smoking-induced AII and increased oxidative stress contributing to less ACEI-related kidney protection in smokers. Baseline eGFR was not different among groups (p = 0.92), but 5-year eGFR was higher in quitters than in continued smokers (62.0 ± 5.4 vs. 52.9 ± 5.6 mL/min/1.73 m2, p < 0.001); this value was lower in quitters than in nonsmokers (64.7 ± 5.6 mL/min/1.73 m2, p = 0.02). Smoking cessation compared with continued smoking ameliorates eGFR decline in nondiabetic CKD treated with ACEI, possibly by restoring kidney-protective effects of ACEI through reductions in kidney AII and oxidative stress. © 2017 S. Karger AG, Basel.

  12. Pharmacological Inhibition of Caspase-2 Protects Axotomised Retinal Ganglion Cells from Apoptosis in Adult Rats

    PubMed Central

    Vigneswara, Vasanthy; Berry, Martin; Logan, Ann; Ahmed, Zubair

    2012-01-01

    Severing the axons of retinal ganglion cells (RGC) by crushing the optic nerve (ONC) causes the majority of RGC to degenerate and die, primarily by apoptosis. We showed recently that after ONC in adult rats, caspase-2 activation occurred specifically in RGC while no localisation of caspase-3 was observed in ganglion cells but in cells of the inner nuclear layer. We further showed that inhibition of caspase-2 using a single injection of stably modified siRNA to caspase-2 protected almost all RGC from death at 7 days, offering significant protection for up to 1 month after ONC. In the present study, we confirmed that cleaved caspase-2 was localised and activated in RGC (and occasional neurons in the inner nuclear layer), while TUNEL+ RGC were also observed after ONC. We then investigated if suppression of caspase-2 using serial intravitreal injections of the pharmacological inhibitor z-VDVAD-fmk (z-VDVAD) protected RGC from death for 15 days after ONC. Treatment of eyes with z-VDVAD suppressed cleaved caspase-2 activation by >85% at 3–4 days after ONC. Increasing concentrations of z-VDVAD protected greater numbers of RGC from death at 15 days after ONC, up to a maximum of 60% using 4000 ng/ml of z-VDVAD, compared to PBS treated controls. The 15-day treatment with 4000 ng/ml of z-VDVAD after ONC suppressed levels of cleaved caspase-2 but no significant changes in levels of cleaved caspase-3, -6, -7 or -8 were detected. Although suppression of caspase-2 protected 60% of RGC from death, RGC axon regeneration was not promoted. These results suggest that caspase-2 specifically mediates death of RGC after ONC and that suppression of caspase-2 may be a useful therapeutic strategy to enhance RGC survival not only after axotomy but also in diseases where RGC death occurs such as glaucoma and optic neuritis. PMID:23285297

  13. Verbascoside isolated from Tectona grandis mediates gastric protection in rats via inhibiting proton pump activity.

    PubMed

    Singh, Neetu; Shukla, Nivedita; Singh, Pratibha; Sharma, Rolee; Rajendran, S M; Maurya, Rakesh; Palit, Gautam

    2010-10-01

    Evidences have suggested that Tectona grandis (TG) attenuates gastric mucosal injury; however its mechanism has not yet been established. The aim of present study was to evaluate the gastroprotective mechanism of ethanolic extract of TG (E-EtOH), butanolic fraction (Fr-Bu) and to identify its active constituents. Anti-ulcer activities were evaluated against cold restraint (CRU) and pyloric ligation (PL) induced gastric ulcer models and further confirmed through H(+) K(+)-ATPase inhibitory activity. Cytoprotective activity was evaluated in alcohol (AL) induced gastric ulcer model and further through PGE(2) level. E-EtOH and Fr-Bu attenuated ulcer formation in CRU. Moreover E-EtOH and Fr-Bu displayed potent anti-secretory activity as evident through reduced free acidity and pepsin activity in PL, confirmed further by in vitro inhibition of H(+) K(+)-ATPase activity. In addition cytoprotective potential of E-EtOH and Fr-Bu were apparent with protection in AL model, increased PGE(2) content and enhanced mucin level in PL. Phytochemical investigations of Fr-Bu yielded terpenoides and a phenolic glycoside, verbascoside. The anti-secretory mechanism of verbascoside mediated apparently through inhibition of H(+) K(+)-ATPase with corresponding decrease in plasma gastrin level, is novel to our finding. Gastroprotection elicited by TG might be through proton pump inhibition and consequent augmentation of the defensive mechanism.

  14. Hydrogen sulfide increases survival during sepsis: Protective effect of CHOP inhibition

    PubMed Central

    Ferlito, Marcella; Wang, Qihong; Fulton, William B; Colombani, Paul; Marchionni, Luigi; Fox-Talbot, Karen; Paolocci, Nazareno; Steenbergen, Charles

    2014-01-01

    Sepsis is a major cause of mortality, and dysregulation of the immune response plays a central role in this syndrome. Hydrogen sulfide (H2S), a recently discovered gaso-transmitter, is endogenously generated by many cell types, regulating a number of physiologic processes and pathophysiologic conditions. Here we report that H2S increased survival after experimental sepsis induced by cecal ligation and puncture (CLP) in mice. Exogenous H2S decreased the systemic inflammatory response, reduced apoptosis in the spleen, and accelerated bacterial eradication. We found that CHOP, a mediator of the endoplasmic reticulum (ER) stress response, was elevated in several organs after CLP and its expression was inhibited by H2S treatment. Using CHOP knockout (KO) mice, we demonstrated for the first time that genetic deletion of Chop increased survival after lipopolysaccharide (LPS) injection or CLP. CHOP KO mice displayed diminished splenic caspase-3 activation and apoptosis, decreased cytokine production and augmented bacterial clearance. Furthermore, septic CHOP KO mice treated with H2S showed no additive survival benefit compared to septic CHOP KO mice. Finally, we showed that H2S inhibited CHOP expression in macrophages by a mechanism involving Nrf2 activation. In conclusion, our findings show a protective effect of H2S treatment afforded, at least partially, by inhibition of CHOP expression. The data reveal a major negative role for the transcription factor CHOP in overall survival during sepsis and suggest a new target for clinical intervention as well potential strategies for treatment. PMID:24403532

  15. Activation of mitochondrial ERK protects cancer cells from death through inhibition of the permeability transition.

    PubMed

    Rasola, Andrea; Sciacovelli, Marco; Chiara, Federica; Pantic, Boris; Brusilow, William S; Bernardi, Paolo

    2010-01-12

    We studied human cancer cell models in which we detected constitutive activation of ERK. A fraction of active ERK was found to be located in mitochondria in RWPE-2 cells, obtained by v-Ki-Ras transformation of the epithelial prostate RWPE-1 cell line; in metastatic prostate cancer DU145 cells; and in osteosarcoma SAOS-2 cells. All these tumor cells displayed marked resistance to death caused by apoptotic stimuli like arachidonic acid and the BH3 mimetic EM20-25, which cause cell death through the mitochondrial permeability transition pore (PTP). PTP desensitization and the ensuing resistance to cell death induced by arachidonic acid or EM20-25 could be ablated by inhibiting ERK with the drug PD98059 or with a selective ERK activation inhibitor peptide. ERK inhibition enhanced glycogen synthase kinase-3 (GSK-3)-dependent phosphorylation of the pore regulator cyclophilin D, whereas GSK-3 inhibition protected from PTP opening. Neither active ERK in mitochondria nor pore desensitization was observed in non-transformed RWPE-1 cells. Thus, in tumor cells mitochondrial ERK activation desensitizes the PTP through a signaling axis that involves GSK-3 and cyclophilin D, a finding that provides a mechanistic basis for increased resistance to apoptosis of neoplastic cells.

  16. Protective effect of the inhibition of the renin-angiotensin system on aging.

    PubMed

    Basso, Nidia; Paglia, Nora; Stella, Inés; de Cavanagh, Elena M V; Ferder, León; del Rosario Lores Arnaiz, María; Inserra, Felipe

    2005-06-30

    Experimental studies indicate that chronic long-term inhibition of the renin-angiotensin system (RAS) can prevent most of the deleterious effects due to aging in the cardiovascular system and in the kidney of the normal mouse and rat. In this review, all the information available on this subject provided by several studies performed by our research group during the last years is been described. Treatment was initiated either after weaning or at 12 months of age that is about half the normal life span of the rat. A converting enzyme inhibitor: enalapril or an angiotensin II type 1 (AT1) receptor blocker: losartan were used to inhibit the RAS. Cognitive behaviour, emotionality, and locomotor activity were also determined at 10 and 18 months of age in treated since weaning and untreated control rats to elucidate the participation of angiotensin II in memory disfunction. A similar observation was obtained in animals treated from 12 to 18 months of age. Results have demonstrated a significant protective effect on the function and the structure of the cardiovascular system, the kidney and the brain in all the treated animals. Damage observed at 12 months of age was not very significant, but treatment stop further deterioration that was evident in untreated animals. The similarity of the results detected with either enalapril or losartan treatment, clearly indicates that most of the effects are exerted through AT1 receptors. Analysis of the nitric oxide and antioxidant enzymes systems suggest that the protective effect is related to an antioxidant action of the RAS inhibitors and a reduced formation of reactive oxygen species. AngII inhibition might produce changes in the mechanisms of oxidative stress specially at the mitochondrial level. Prevention of mitochondrial decrease and/or damage would be related with the delay of the normal aging process.

  17. Simvastatin combined with nifedipine enhances endothelial cell protection by inhibiting ROS generation and activating Akt phosphorylation

    PubMed Central

    Chen, Xiao-niao; Xu, Jun; Feng, Zhe; Fan, Ming; Han, Jing-yao; Yang, Zhuo

    2010-01-01

    Aim: To investigate the protective effects of simvastatin (Sim) combined with nifedipine (Nif) on endothelial cells and elucidate the action mechanism. Methods: Human umbilical vein endothelial cells (HUVEC) were used. mRNA and protein levels were measured by using reverse-transcription polymerase chain reaction (RT-PCR) and Western blotting, respectively. Intracellular calcium and reactive oxygen species (ROS) were detected using confocal microscopy. The Griess assay was used to evaluate nitric oxide (NO) release. Results: Treatment of HUVEC with H2O2 100 μmol/L for 30 min inhibited the mRNA and protein expression of endothelial nitric oxide synthase (eNOS). With increased concentrations of Nif, eNOS mRNA and protein levels increased (P<0.05). Combined treatment with Sim 1.0 μmol/L and Nif 1.0 μmol/L significantly increased the mRNA and protein expression of eNOS and NO release compared with Sim or Nif alone (P<0.05). The combination significantly lowered the intracellular ROS level (P<0.05), which was correlated with the increase in eNOS and NO, but there was no visible change in intracellular calcium (P>0.05). Compared with individual drug treatment, Akt phosphorylation and the ratio of p-eNOS/eNOS were up-regulated in the combination group, and this effect was inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and LY294002. Conclusion: The Sim-Nif combination effectively protects HUVEC against H2O2 injury by inhibiting intracellular ROS generation, increasing the ratio of p-eNOS/eNOS and up-regulating Akt phosphorylation. PMID:20562903

  18. Curcumin protects endothelial cells against homocysteine induced injury through inhibiting inflammation

    PubMed Central

    Li, Jian; Luo, Ming; Xie, Nanzi; Wang, Jianxin; Chen, Li

    2016-01-01

    Objective: This study aimed to investigate the protective effects of curcumin on the homocysteine (HCY) induced injury to the endothelial cells. Methods: Endothelial cells were treated with HCY at different concentrations, and MTT assay was employed to determine an optimal concentration of HCY. Cells were divided into 3 groups: normal control group, HCY group and HCY + curcumin group. In curcumin group, cells were pretreated with 2.5 mmol/L HCY for 2 h and then incubated with curcumin at different concentrations. MTT assay was employed to detect the cell viability. ELISA was performed to detect the content of IL-8 in the supernatant. Western blotting was used to detect NF-κB expression in cells. Results: (1) Endothelial cells were polygonal or stone-like, or aggregated to form masses, and then gradually became long spindle shaped, cell body enlarged, cells were rich in cytoplasm, and immunohistochemistry for factor VIII showed positive. (2) MTT assay showed HCY at ≥2.5 mmol/L caused significant damage to endothelial cells as compared to control group. Thus, 2.5 mmol/L HCY was used in following experiments. (3) ELISA showed IL-8 in the supernatant increased significantly in a time dependent manner after HCY treatment (P<0.01), but curcumin could significantly inhibit the IL-8 secretion in endothelial cells after HCY treatment. (4) Western blotting showed HCY was able to markedly increase NF-κB expression, which, however, was significantly inhibited by curcumin. Conclusion: Curcumin is able to protect the endothelial cells against HCY induced injury through inhibiting NF-κB activation and down-regulating IL-8 expression. PMID:27904665

  19. Ginger phenylpropanoids inhibit IL-1beta and prostanoid secretion and disrupt arachidonate-phospholipid remodeling by targeting phospholipases A2.

    PubMed

    Nievergelt, Andreas; Marazzi, Janine; Schoop, Roland; Altmann, Karl-Heinz; Gertsch, Jürg

    2011-10-15

    The rhizome of ginger (Zingiber officinale) is employed in Asian traditional medicine to treat mild forms of rheumatoid arthritis and fever. We have profiled ginger constituents for robust effects on proinflammatory signaling and cytokine expression in a validated assay using human whole blood. Independent of the stimulus used (LPS, PMA, anti-CD28 Ab, anti-CD3 Ab, and thapsigargin), ginger constituents potently and specifically inhibited IL-1β expression in monocytes/macrophages. Both the calcium-independent phospholipase A(2) (iPLA(2))-triggered maturation and the cytosolic phospholipase A(2) (cPLA(2))-dependent secretion of IL-1β from isolated human monocytes were inhibited. In a fluorescence-coupled PLA(2) assay, most major ginger phenylpropanoids directly inhibited i/cPLA(2) from U937 macrophages, but not hog pancreas secretory phospholipase A(2). The effects of the ginger constituents were additive and the potency comparable to the mechanism-based inhibitor bromoenol lactone for iPLA(2) and methyl arachidonyl fluorophosphonate for cPLA(2), with 10-gingerol/-shogaol being most effective. Furthermore, a ginger extract (2 μg/ml) and 10-shogaol (2 μM) potently inhibited the release of PGE(2) and thromboxane B2 (>50%) and partially also leukotriene B(4) in LPS-stimulated macrophages. Intriguingly, the total cellular arachidonic acid was increased 2- to 3-fold in U937 cells under all experimental conditions. Our data show that the concurrent inhibition of iPLA(2) and prostanoid production causes an accumulation of free intracellular arachidonic acid by disrupting the phospholipid deacylation-reacylation cycle. The inhibition of i/cPLA(2), the resulting attenuation of IL-1β secretion, and the simultaneous inhibition of prostanoid production by common ginger phenylpropanoids uncover a new anti-inflammatory molecular mechanism of dietary ginger that may be exploited therapeutically.

  20. Secretoglobin 3A2 attenuates lipopolysaccharide-induced inflammation through inhibition of ERK and JNK pathways in bronchial epithelial cells.

    PubMed

    Wang, Xintao; Tanino, Yoshinori; Sato, Suguru; Nikaido, Takefumi; Misa, Kenichi; Fukuhara, Naoko; Fukuhara, Atsuro; Saito, Junpei; Yokouchi, Hiroshi; Ishida, Takashi; Fujita, Teizo; Munakata, Mitsuru

    2015-04-01

    Secretoglobin (SCGB) 3A2, previously known as uteroglobin-related protein 1, is a secreted protein highly expressed in the epithelial cells of the airways. It has been demonstrated that SCGB3A2 is involved in allergic airway inflammation such as bronchial asthma. However, the role of SCGB3A2 in lipopolysaccharide (LPS)-induced airway inflammation has yet to be reported. The goal of this study was therefore to clarify the role of SCGB3A2 in LPS-induced airway inflammation. We stimulated BEAS-2B, human bronchial epithelial cells, with LPS and analyzed messenger RNA (mRNA) expression of tumor necrosis factor (TNF)-α and CXCL8 with or without pre-incubation of SCGB3A2. The mRNA expression of TNF-α and CXCL8 was clearly upregulated 3 h after LPS stimulation, and pre-incubation of SCGB3A2 significantly inhibited the upregulation of the mRNA expression. The pre-incubation of SCGB3A2 also inhibited LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), but not p38 mitogen-activated protein kinase in BEAS-2B cells. Furthermore, PD98059, a specific inhibitor for ERK, as well as SP600125, a specific inhibitor for JNK, inhibited LPS-induced mRNA upregulation of inflammatory mediators. These results demonstrate the novel biological activity of SCGB3A2, which is that it attenuates LPS-induced inflammation in bronchial epithelial cells through inhibition of ERK and JNK activation.

  1. Inhibition of phagocytosis by Haemophilus ducreyi requires expression of the LspA1 and LspA2 proteins.

    PubMed

    Vakevainen, Merja; Greenberg, Steven; Hansen, Eric J

    2003-10-01

    Haemophilus ducreyi previously has been shown to inhibit the phagocytosis of both secondary targets and itself by certain cells in vitro. Wild-type H. ducreyi strain 35000HP contains two genes, lspA1 and lspA2, whose encoded protein products are predicted to be 456 and 543 kDa, respectively. An isogenic mutant of H. ducreyi 35000HP with inactivated lspA1 and lspA2 genes has been shown to exhibit substantially decreased virulence in the temperature-dependent rabbit model for chancroid. This lspA1 lspA2 mutant was tested for its ability to inhibit phagocytosis of immunoglobulin G-opsonized particles by differentiated HL-60 and U-937 cells and by J774A.1 cells. The wild-type strain H. ducreyi 35000HP readily inhibited phagocytosis, whereas the lspA1 lspA2 mutant was unable to inhibit phagocytosis. Similarly, the wild-type strain was resistant to phagocytosis, whereas the lspA1 lspA2 mutant was readily engulfed by phagocytes. This inhibitory effect of wild-type H. ducreyi on phagocytic activity was primarily associated with live bacterial cells but could also be found, under certain conditions, in concentrated H. ducreyi culture supernatant fluids that lacked detectable outer membrane fragments. Both the wild-type strain and the lspA1 lspA2 mutant attached to phagocytes at similar levels. These results indicate that the LspA1 and LspA2 proteins of H. ducreyi are involved, directly or indirectly, in the antiphagocytic activity of this pathogen, and they provide a possible explanation for the greatly reduced virulence of the lspA1 lspA2 mutant.

  2. Peroxisome Proliferator-Activated Receptor-α Inhibition Protects Against Doxorubicin-Induced Cardiotoxicity in Mice.

    PubMed

    Rahmatollahi, Mahdieh; Baram, Somayeh Mahmoodi; Rahimian, Reza; Saeedi Saravi, Seyed Soheil; Dehpour, Ahmad Reza

    2016-07-01

    Doxorubicin is an effective chemotherapeutic drug against a considerable number of malignancies. However, its toxic effects on myocardium are confirmed as major limit of utilization. PPAR-α is highly expressed in the heart, and its activation leads to an increased cardiac fatty acid oxidation and cardiomyocyte necrosis. This study was performed to adjust the hypothesis that PPAR-α receptor inhibition protects against doxorubicin-induced cardiac dysfunction in mice. Male Balb/c mice were used in this study. Left atria were isolated, and their contractility was measured in response to electrical field stimulation in a standard organ bath. PPAR-α activity was measured using specific PPAR-α antibody in an ELISA-based system coated with double-strand DNA containing PPAR-α response element sequence. Moreover, cardiac MDA and TNF-α levels were measured by ELISA method. Following incubation with doxorubicin (35 µM), a significant reduction in atrial contractility was observed (P < 0.001). Pretreatment of animals with a selective PPAR-α antagonist, GW6471, significantly improved doxorubicin-induced atrial dysfunction (P < 0.001). Furthermore, pretreatment of the mice with a non-selective cannabinoid agonist, WIN55212-2, significantly decreased PPAR-α activity in cardiac tissue, subsequently leading to significant improvement in doxorubicin-induced atrial dysfunction (P < 0.001). Also, GW6471 and WIN significantly reduced cardiac MDA and TNF-α levels compared with animals receiving doxorubicin (P < 0.001). The study showed that inhibition of PPAR-α is associated with protection against doxorubicin-induced cardiotoxicity in mice, and cannabinoids can potentiate the protection by PPAR-α blockade. Moreover, PPAR-α may be considered as a target to prevent cardiotoxicity induced by doxorubicin in patients undergoing chemotherapy.

  3. Emodin Combined with Nanosilver Inhibited Sepsis by Anti-inflammatory Protection.

    PubMed

    Li, Hong; Yang, Tian; Zhou, Hong; Du, Juan; Zhu, Bo; Sun, Zhongmin

    2016-01-01

    Background: Emodin is the main active component of rhubarb, which has demonstrated many beneficial effects against inflammation. Nanosilver is an effective antimicrobial agent. The present study was designed to observe the effects of Emodin combined with silver nanoparticles (E/S) on sepsis protection and related mechanism. Methods: E/S was prepared by loading different concentrations of Emodin on nanosilver and cytotoxicity of E/S were determined by suphorhodamine B assays. Anti-microbial activities of E/S were assayed by direct interaction with various common pathogens and anti-adhesive activites of E/S on leukocytes with endothelial cells were assayed by biochemical analysis. Next, inflammatory cell enumeration, inflammatory mediators in bronchoalveolar lavage fluid (BALF) and endothelial cell function were analyzed on a clinically relevant model of sepsis induced by cecal ligation and puncture (CLP) after E/S administration. The effects of E/S on NF-κB and p38 were also examined by western blot. Results: E/S exhibited little cytotoxicity action on endothelial cells and significant inhibitory activities against all tested common microorganisms and adherence between leukocyte and endothelial cells. E/S induced anti-sepsis protection mainly mediated by inhibition of inflammatory cells infiltration, down-regulation of TNF-alpha, IL-8 and lactic dehydrogenase (LDH), and inhibition of NF-κB and p38 pathways in mice 24 h post-CLP. Conclusion: Our data suggest that E/S has strong anti-sepsis effects, which was related with anti-inflammatory protection and thereby promote survival following sepsis challenge.

  4. Emodin Combined with Nanosilver Inhibited Sepsis by Anti-inflammatory Protection

    PubMed Central

    Li, Hong; Yang, Tian; Zhou, Hong; Du, Juan; Zhu, Bo; Sun, Zhongmin

    2017-01-01

    Background: Emodin is the main active component of rhubarb, which has demonstrated many beneficial effects against inflammation. Nanosilver is an effective antimicrobial agent. The present study was designed to observe the effects of Emodin combined with silver nanoparticles (E/S) on sepsis protection and related mechanism. Methods: E/S was prepared by loading different concentrations of Emodin on nanosilver and cytotoxicity of E/S were determined by suphorhodamine B assays. Anti-microbial activities of E/S were assayed by direct interaction with various common pathogens and anti-adhesive activites of E/S on leukocytes with endothelial cells were assayed by biochemical analysis. Next, inflammatory cell enumeration, inflammatory mediators in bronchoalveolar lavage fluid (BALF) and endothelial cell function were analyzed on a clinically relevant model of sepsis induced by cecal ligation and puncture (CLP) after E/S administration. The effects of E/S on NF-κB and p38 were also examined by western blot. Results: E/S exhibited little cytotoxicity action on endothelial cells and significant inhibitory activities against all tested common microorganisms and adherence between leukocyte and endothelial cells. E/S induced anti-sepsis protection mainly mediated by inhibition of inflammatory cells infiltration, down-regulation of TNF-alpha, IL-8 and lactic dehydrogenase (LDH), and inhibition of NF-κB and p38 pathways in mice 24 h post-CLP. Conclusion: Our data suggest that E/S has strong anti-sepsis effects, which was related with anti-inflammatory protection and thereby promote survival following sepsis challenge. PMID:28119611

  5. The atypical cannabinoid O-1602 protects against experimental colitis and inhibits neutrophil recruitment

    PubMed Central

    Schicho, Rudolf; Bashashati, Mohammad; Bawa, Misha; McHugh, Douglas; Saur, Dieter; Hu, Huang-Ming; Zimmer, Andreas; Lutz, Beat; Mackie, Ken; Bradshaw, Heather B.; McCafferty, Donna-Marie; Sharkey, Keith A.; Storr, Martin

    2010-01-01

    Background Cannabinoids are known to reduce intestinal inflammation. Atypical cannabinoids produce pharmacological effects via unidentified targets. We were interested whether the atypical cannabinoid O-1602, reportedly an agonist of the putative cannabinoid receptor GPR55, reduces disease severity of dextran sulfate sodium (DSS) and trinitrobenzene sulfonic acid (TNBS)-induced colitis in C57BL/6N and CD1 mice. Methods DSS (2.5% and 4%) was supplied in drinking water for one week while TNBS (4 mg) was applied as a single intrarectal bolus. Results Both treatments caused severe colitis. Injection of O-1602 (5 mg/kg i.p.) significantly reduced macroscopic and histological colitis scores, and myeloperoxidase activity. The protective effect was still present in cannabinoid receptor 1 (CB1) and 2 (CB2) double knockout mice and mice lacking the GPR55 gene. To investigate a potential mechanism underlying the protection by O-1602 we performed neutrophil chemotactic assays. O-1602 concentration-dependently inhibited migration of murine neutrophils to keratinocyte-derived chemokine (KC), N-formyl-methionyl-leucyl-phenylalanine (fMLP) and the N-formyl-peptide receptor ligand WKYMVm. The inhibitory effect of O-1602 was preserved in neutrophils from CB1/CB2 double knockout and GPR55 knockout mice. No differences were seen in locomotor activity between O-1602-treated and control mice indicating lack of central sedation by this compound. Conclusions Our data demonstrate that O-1602 is protective against experimentally induced colitis and inhibits neutrophil recruitment independently of CB1, CB2 and GPR55 receptors. Thus, atypical cannabinoids represent a novel class of therapeutics that may be useful for the treatment of inflammatory bowel diseases. PMID:21744421

  6. The Alzheimer disease protective mutation A2T modulates kinetic and thermodynamic properties of amyloid-β (Aβ) aggregation.

    PubMed

    Benilova, Iryna; Gallardo, Rodrigo; Ungureanu, Andreea-Alexandra; Castillo Cano, Virginia; Snellinx, An; Ramakers, Meine; Bartic, Carmen; Rousseau, Frederic; Schymkowitz, Joost; De Strooper, Bart

    2014-11-07

    Missense mutations in alanine 673 of the amyloid precursor protein (APP), which corresponds to the second alanine of the amyloid β (Aβ) sequence, have dramatic impact on the risk for Alzheimer disease; A2V is causative, and A2T is protective. Assuming a crucial role of amyloid-Aβ in neurodegeneration, we hypothesized that both A2V and A2T mutations cause distinct changes in Aβ properties that may at least partially explain these completely different phenotypes. Using human APP-overexpressing primary neurons, we observed significantly decreased Aβ production in the A2T mutant along with an enhanced Aβ generation in the A2V mutant confirming earlier data from non-neuronal cell lines. More importantly, thioflavin T fluorescence assays revealed that the mutations, while having little effect on Aβ42 peptide aggregation, dramatically change the properties of the Aβ40 pool with A2V accelerating and A2T delaying aggregation of the Aβ peptides. In line with the kinetic data, Aβ A2T demonstrated an increase in the solubility at equilibrium, an effect that was also observed in all mixtures of the A2T mutant with the wild type Aβ40. We propose that in addition to the reduced β-secretase cleavage of APP, the impaired propensity to aggregate may be part of the protective effect conferred by A2T substitution. The interpretation of the protective effect of this mutation is thus much more complicated than proposed previously.

  7. The Alzheimer Disease Protective Mutation A2T Modulates Kinetic and Thermodynamic Properties of Amyloid-β (Aβ) Aggregation*

    PubMed Central

    Benilova, Iryna; Gallardo, Rodrigo; Ungureanu, Andreea-Alexandra; Castillo Cano, Virginia; Snellinx, An; Ramakers, Meine; Bartic, Carmen; Rousseau, Frederic; Schymkowitz, Joost; De Strooper, Bart

    2014-01-01

    Missense mutations in alanine 673 of the amyloid precursor protein (APP), which corresponds to the second alanine of the amyloid β (Aβ) sequence, have dramatic impact on the risk for Alzheimer disease; A2V is causative, and A2T is protective. Assuming a crucial role of amyloid-Aβ in neurodegeneration, we hypothesized that both A2V and A2T mutations cause distinct changes in Aβ properties that may at least partially explain these completely different phenotypes. Using human APP-overexpressing primary neurons, we observed significantly decreased Aβ production in the A2T mutant along with an enhanced Aβ generation in the A2V mutant confirming earlier data from non-neuronal cell lines. More importantly, thioflavin T fluorescence assays revealed that the mutations, while having little effect on Aβ42 peptide aggregation, dramatically change the properties of the Aβ40 pool with A2V accelerating and A2T delaying aggregation of the Aβ peptides. In line with the kinetic data, Aβ A2T demonstrated an increase in the solubility at equilibrium, an effect that was also observed in all mixtures of the A2T mutant with the wild type Aβ40. We propose that in addition to the reduced β-secretase cleavage of APP, the impaired propensity to aggregate may be part of the protective effect conferred by A2T substitution. The interpretation of the protective effect of this mutation is thus much more complicated than proposed previously. PMID:25253695

  8. Up-regulation of eEF1A2 promotes proliferation and inhibits apoptosis in prostate cancer

    SciTech Connect

    Sun, Yue; Du, Chengli; Wang, Bo; Zhang, Yanling; Liu, Xiaoyan; Ren, Guoping

    2014-07-18

    Highlights: • The expression of eEF1A2 is up-regulated in prostate cancer tissues. • Suppression of eEF1A2 inhibits the proliferation and promotes apoptosis. • Inhibition of eEF1A2 enhances the expression of apoptotic relevant proteins. • The expressions of eEF1A2 and cleavage-caspase3 are inversely correlated. - Abstract: Background: eEF1A2 is a protein translation factor involved in protein synthesis, which possesses important function roles in cancer development. This study aims at investigating the expression pattern of eEF1A2 in prostate cancer and its potential role in prostate cancer development. Methods: We examined the expression level of eEF1A2 in 30 pairs of prostate cancer tissues by using RT-PCR and immunohistochemical staining (IHC). Then we applied siRNA specifically targeting eEF1A2 to down-regulate its expression in DU-145 and PC-3 cells. Flow cytometer was used to explore apoptosis and Western-blot was used to detect the pathway proteins of apoptosis. Results: Our results showed that the expression level of eEF1A2 in prostate cancer tissues was significantly higher compared to their corresponding normal tissues. Reduction of eEF1A2 expression in DU-145 and PC-3 cells led to a dramatic inhibition of proliferation accompanied with enhanced apoptosis rate. Western blot revealed that apoptosis pathway proteins (caspase3, BAD, BAX, PUMA) were significantly up-regulated after suppression of eEF1A2. More importantly, the levels of eEF1A2 and caspase3 were inversely correlated in prostate cancer tissues. Conclusion: Our data suggests that eEF1A2 plays an important role in prostate cancer development, especially in inhibiting apoptosis. So eEF1A2 might serve as a potential therapeutic target in prostate cancer.

  9. Free radical scavenging, DNA protection, and inhibition of lipid peroxidation mediated by uric acid.

    PubMed

    Stinefelt, Beth; Leonard, Stephen S; Blemings, Kenneth P; Shi, Xianglin; Klandorf, Hillar

    2005-01-01

    Uric acid (UA) has been proposed to be the dominant antioxidant in birds. The objective of this study was to investigate the quenching effect of varying concentrations of UA, including those found in avian plasma, on specific reactive oxygen species (ROS) and to determine the ability of UA to protect DNA and cellular membranes from ROS-mediated damage. Hydroxyl (OH) and superoxide (O2-) radicals were detected by electron spin resonance (ESR) and their presence was reduced following addition of UA (p <0.05) in a concentration-dependent manner. UA inhibited hydroxyl-mediated DNA damage, indicated by the presence of more precise, dense bands of lambda Hind III DNA after agarose gel electrophoresis and ethidium bromide staining (p <0.05). Lipid peroxidation of silica-exposed RAW 264.7 cell membranes was diminished (p <0.02) after addition of UA to the cell incubation mixture. These studies demonstrate that UA scavenges hydroxyl and superoxide radicals and protects against DNA damage and lipid peroxidation. These results indicate specific antioxidant protection that UA may afford birds against ROS-mediated damage.

  10. Identification of protective Lassa virus epitopes that are restricted by HLA-A2.

    PubMed

    Botten, Jason; Alexander, Jeff; Pasquetto, Valerie; Sidney, John; Barrowman, Polly; Ting, Joey; Peters, Bjoern; Southwood, Scott; Stewart, Barbara; Rodriguez-Carreno, Maria P; Mothe, Bianca; Whitton, J Lindsay; Sette, Alessandro; Buchmeier, Michael J

    2006-09-01

    Recovery from Lassa virus (LASV) infection usually precedes the appearance of neutralizing antibodies, indicating that cellular immunity plays a primary role in viral clearance. To date, the role of LASV-specific CD8(+) T cells has not been evaluated in humans. To facilitate such studies, we utilized a predictive algorithm to identify candidate HLA-A2 supertype epitopes from the LASV nucleoprotein and glycoprotein precursor (GPC) genes. We identified three peptides (GPC(42-50), GLVGLVTFL; GPC(60-68), SLYKGVYEL; and GPC(441-449), YLISIFLHL) that displayed high-affinity binding (< or =98 nM) to HLA-A*0201, induced CD8(+) T-cell responses of high functional avidity in HLA-A*0201 transgenic mice, and were naturally processed from native LASV GPC in human HLA-A*0201-positive target cells. HLA-A*0201 mice immunized with either GPC(42-50) or GPC(60-68) were protected against challenge with a recombinant vaccinia virus that expressed LASV GPC. The epitopes identified in this study represent potential diagnostic reagents and candidates for inclusion in epitope-based vaccine constructs. Our approach is applicable to any pathogen with existing sequence data, does not require manipulation of the actual pathogen or access to immune human donors, and should therefore be generally applicable to category A through C agents and other emerging pathogens.

  11. Kaurane diterpenes protect against apoptosis and inhibition of phagocytosis in activated macrophages

    PubMed Central

    de las Heras, B; Hortelano, S; Girón, N; Bermejo, P; Rodríguez, B; Boscá, L

    2007-01-01

    Background and purpose: The kaurane diterpenes foliol and linearol are inhibitors of the activation of nuclear factor κB, a transcription factor involved in the inflammatory response. Effects of these diterpenes on apoptosis and phagocytosis have been analysed in cultured peritoneal macrophages and in the mouse macrophage cell line, RAW 264.7. Experimental approach: Macrophages were maintained in culture and activated with pro-inflammatory stimuli in the absence or presence of diterpenes. Apoptosis and the phagocytosis in these cells under these conditions were determined. Key results: Incubation of macrophages with a mixture of bacterial lipopolysaccharide (LPS)/interferon-γ (IFN-γ) induced apoptosis through a NO-dependent pathway, an effect significantly inhibited by foliol and linearol in the low μM range, without cytotoxic effects. Apoptosis in macrophages induced by NO donors was also inhibited. The diterpenes prevented apoptosis through a mechanism compatible with the inhibition of caspase-3 activation, release of cytochrome c to the cytosol and p53 overexpression, as well as an alteration in the levels of proteins of the Bcl-2 family, in particular, the levels of Bax. Cleavage of poly(ADP-ribose) polymerase, a well-established caspase substrate, was reduced by these diterpenes. Treatment of cells with foliol and linearol decreased phagocytosis of zymosan bioparticles by RAW 264.7 cells and to a greater extent by peritoneal macrophages. Conclusions and implications: Both diterpenes protected macrophages from apoptosis and inhibited phagocytosis, resulting in a paradoxical control of macrophage function, as viability was prolonged but inflammatory and phagocytic functions were impaired. PMID:17618303

  12. Hydroxysafflor Yellow A Protects Neurons From Excitotoxic Death through Inhibition of NMDARs

    PubMed Central

    Wang, Xingtao; Ma, Zhiyuan; Fu, Zhongxiao; Gao, Su; Yang, Liu; Jin, Yan; Sun, Hui; Wang, Chaoyun; Fan, Weiming; Chen, Lin; Zheng, Qing-Yin; Bi, Guoqiang

    2016-01-01

    demonstrate for the first time that HSYA protects hippocampal neurons from excitotoxic damage through the inhibition of NMDARs. This novel finding indicates that HSYA may be a promising pharmacological candidate for the treatment of brain ischemia. PMID:27067428

  13. Inhibition of Rac1 reduces store overload-induced calcium release and protects against ventricular arrhythmia.

    PubMed

    Zhang, Lili; Lu, Xiangru; Gui, Le; Wu, Yan; Sims, Stephen M; Wang, Guoping; Feng, Qingping

    2016-08-01

    Rac1 is a small GTPase and plays key roles in multiple cellular processes including the production of reactive oxygen species (ROS). However, whether Rac1 activation during myocardial ischaemia and reperfusion (I/R) contributes to arrhythmogenesis is not fully understood. We aimed to study the effects of Rac1 inhibition on store overload-induced Ca(2+) release (SOICR) and ventricular arrhythmia during myocardial I/R. Adult Rac1(f/f) and cardiac-specific Rac1 knockdown (Rac1(ckd) ) mice were subjected to myocardial I/R and their electrocardiograms (ECGs) were monitored for ventricular arrhythmia. Myocardial Rac1 activity was increased and ventricular arrhythmia was induced during I/R in Rac1(f/f) mice. Remarkably, I/R-induced ventricular arrhythmia was significantly decreased in Rac1(ckd) compared to Rac1(f/f) mice. Furthermore, treatment with Rac1 inhibitor NSC23766 decreased I/R-induced ventricular arrhythmia. Ca(2+) imaging analysis showed that in response to a 6 mM external Ca(2+) concentration challenge, SOICR was induced with characteristic spontaneous intracellular Ca(2+) waves in Rac1(f/f) cardiomyocytes. Notably, SOICR was diminished by pharmacological and genetic inhibition of Rac1 in adult cardiomyocytes. Moreover, I/R-induced ROS production and ryanodine receptor 2 (RyR2) oxidation were significantly inhibited in the myocardium of Rac1(ckd) mice. We conclude that Rac1 activation induces ventricular arrhythmia during myocardial I/R. Inhibition of Rac1 suppresses SOICR and protects against ventricular arrhythmia. Blockade of Rac1 activation may represent a new paradigm for the treatment of cardiac arrhythmia in ischaemic heart disease. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  14. Inhibition of HDAC6 protects against rhabdomyolysis-induced acute kidney injury.

    PubMed

    Shi, Yingfeng; Xu, Liuqing; Tang, Jinhua; Fang, Lu; Ma, Shuchen; Ma, Xiaoyan; Nie, Jing; Pi, Xiaoling; Qiu, Andong; Zhuang, Shougang; Liu, Na

    2017-03-01

    Histone deacetylase 6 (HDAC6) inhibition has been reported to protect against ischemic stroke and prolong survival after sepsis in animal models. However, it remains unknown whether HDAC6 inhibition offers a renoprotective effect after acute kidney injury (AKI). In this study, we examined the effect of tubastatin A (TA), a highly selective inhibitor of HDAC6, on AKI in a murine model of glycerol (GL) injection-induced rhabdomyolysis. Following GL injection, the mice developed severe acute tubular injury as indicated by renal dysfunction; expression of neutrophil gelatinase-associated lipocalin (NGAL), an injury marker of renal tubules; and an increase of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells. These changes were companied by increased HDAC6 expression in the cytoplasm of renal tubular cells. Administration of TA significantly reduced serum creatinine and blood urea nitrogen levels as well as attenuated renal tubular damage in injured kidneys. HDAC6 inhibition also resulted in decreased expression of NGAL, reduced apoptotic cell, and inactivated caspase-3 in the kidney after acute injury. Moreover, injury to the kidney increased phosphorylation of nuclear factor (NF)-κB and expression of multiple cytokines/chemokines including tumor necrotic factor-α and interleukin-6 and monocyte chemoattractant protein-1, as well as macrophage infiltration. Treatment with TA attenuated all those responses. Finally, HDAC6 inhibition reduced the level of oxidative stress by suppressing malondialdehyde (MDA) and preserving expression of superoxide dismutase (SOD) in the injured kidney. Collectively, these data indicate that HDAC6 contributes to the pathogenesis of rhabdomyolysis-induced AKI and suggest that HDAC6 inhibitors have therapeutic potential for AKI treatment.

  15. Identification and characterization of reactive metabolites in myristicin-mediated mechanism-based inhibition of CYP1A2.

    PubMed

    Yang, Ai-Hong; He, Xin; Chen, Jun-Xiu; He, Li-Na; Jin, Chun-Huan; Wang, Li-Li; Zhang, Fang-Liang; An, Li-Jun

    2015-07-25

    Myristicin belongs to the methylenedioxyphenyl or allyl-benzene family of compounds, which are found widely in plants of the Umbelliferae family, such as parsley and carrot. Myristicin is also the major active component in the essential oils of mace and nutmeg. However, this compound can cause adverse reactions, particularly when taken inappropriately or in overdoses. One important source of toxicity of natural products arises from their metabolic biotransformations into reactive metabolites. Myristicin contains a methylenedioxyphenyl substructure, and this specific structural feature may allow compounds to cause a mechanism-based inhibition of cytochrome P450 enzymes and produce reactive metabolites. Therefore, the aim of this work was to identify whether the role of myristicin in CYP enzyme inhibition is mechanism-based inhibition and to gain further information regarding the structure of the resulting reactive metabolites. CYP cocktail assays showed that myristicin most significantly inhibits CYP1A2 among five CYP enzymes (CYP1A2, CYP2D6, CYP2E1, CYP3A4 and CYP2C19) from human liver microsomes. The 3.21-fold IC50 shift value of CYP1A2 indicates that myristicin may be a mechanism-based inhibitor of CYP1A2. Next, reduced glutathione was shown to block the inhibition of CYP1A2, indicating that myristicin utilized a mechanism-based inhibition. Phase I metabolism assays identified two metabolites, 5-allyl-1-methoxy-2,3-dihydroxybenzene (M1) and 1'-hydroxymyristicin or 2',3'-epoxy-myristicin (M2). Reduced glutathione capturing assays captured the glutathione-M1 adduct, and the reactive metabolites were identified using UPLC-MS(2) as a quinone and its tautomer. Thus, it was concluded that myristicin is a mechanism-based inhibitor of CYP1A2, and the reactive metabolites are quinone tautomers. Additionally, the cleavage process of the glutathione-M1 adduct was analyzed in further detail. This study provides additional information on the metabolic mechanism of myristicin

  16. MUC16 provides immune protection by inhibiting synapse formation between NK and ovarian tumor cells

    PubMed Central

    2010-01-01

    Background Cancer cells utilize a variety of mechanisms to evade immune detection and attack. Effective immune detection largely relies on the formation of an immune synapse which requires close contact between immune cells and their targets. Here, we show that MUC16, a heavily glycosylated 3-5 million Da mucin expressed on the surface of ovarian tumor cells, inhibits the formation of immune synapses between NK cells and ovarian tumor targets. Our results indicate that MUC16-mediated inhibition of immune synapse formation is an effective mechanism employed by ovarian tumors to evade immune recognition. Results Expression of low levels of MUC16 strongly correlated with an increased number of conjugates and activating immune synapses between ovarian tumor cells and primary naïve NK cells. MUC16-knockdown ovarian tumor cells were more susceptible to lysis by primary NK cells than MUC16 expressing controls. This increased lysis was not due to differences in the expression levels of the ligands for the activating receptors DNAM-1 and NKG2D. The NK cell leukemia cell line (NKL), which does not express KIRs but are positive for DNAM-1 and NKG2D, also conjugated and lysed MUC16-knockdown cells more efficiently than MUC16 expressing controls. Tumor cells that survived the NKL challenge expressed higher levels of MUC16 indicating selective lysis of MUC16low targets. The higher csMUC16 levels on the NKL resistant tumor cells correlated with more protection from lysis as compared to target cells that were never exposed to the effectors. Conclusion MUC16, a carrier of the tumor marker CA125, has previously been shown to facilitate ovarian tumor metastasis and inhibits NK cell mediated lysis of tumor targets. Our data now demonstrates that MUC16 expressing ovarian cancer cells are protected from recognition by NK cells. The immune protection provided by MUC16 may lead to selective survival of ovarian cancer cells that are more efficient in metastasizing within the peritoneal

  17. MUC16 provides immune protection by inhibiting synapse formation between NK and ovarian tumor cells.

    PubMed

    Gubbels, Jennifer A A; Felder, Mildred; Horibata, Sachi; Belisle, Jennifer A; Kapur, Arvinder; Holden, Helen; Petrie, Sarah; Migneault, Martine; Rancourt, Claudine; Connor, Joseph P; Patankar, Manish S

    2010-01-20

    Cancer cells utilize a variety of mechanisms to evade immune detection and attack. Effective immune detection largely relies on the formation of an immune synapse which requires close contact between immune cells and their targets. Here, we show that MUC16, a heavily glycosylated 3-5 million Da mucin expressed on the surface of ovarian tumor cells, inhibits the formation of immune synapses between NK cells and ovarian tumor targets. Our results indicate that MUC16-mediated inhibition of immune synapse formation is an effective mechanism employed by ovarian tumors to evade immune recognition. Expression of low levels of MUC16 strongly correlated with an increased number of conjugates and activating immune synapses between ovarian tumor cells and primary naïve NK cells. MUC16-knockdown ovarian tumor cells were more susceptible to lysis by primary NK cells than MUC16 expressing controls. This increased lysis was not due to differences in the expression levels of the ligands for the activating receptors DNAM-1 and NKG2D. The NK cell leukemia cell line (NKL), which does not express KIRs but are positive for DNAM-1 and NKG2D, also conjugated and lysed MUC16-knockdown cells more efficiently than MUC16 expressing controls. Tumor cells that survived the NKL challenge expressed higher levels of MUC16 indicating selective lysis of MUC16(low) targets. The higher csMUC16 levels on the NKL resistant tumor cells correlated with more protection from lysis as compared to target cells that were never exposed to the effectors. MUC16, a carrier of the tumor marker CA125, has previously been shown to facilitate ovarian tumor metastasis and inhibits NK cell mediated lysis of tumor targets. Our data now demonstrates that MUC16 expressing ovarian cancer cells are protected from recognition by NK cells. The immune protection provided by MUC16 may lead to selective survival of ovarian cancer cells that are more efficient in metastasizing within the peritoneal cavity and also at overcoming

  18. Identification of inhibitory component in cinnamon--O-methoxycinnamaldehyde inhibits CYP1A2 and CYP2E1-.

    PubMed

    Hasegawa, Atsushi; Yoshino, Masaki; Nakamura, Hiroyoshi; Ishii, Itsuko; Watanabe, Toshiko; Kiuchi, Masahiro; Ishikawa, Tsutomu; Ohmori, Shigeru; Kitada, Mitsukazu

    2002-01-01

    The Cinnamomi Cortex and Ephedra Herba were found to more strongly inhibit aminopyrine N-demethylation in rat liver microsomes compared to other constituents included in Sho-seiryu-to. The component inhibiting drug oxidations catalyzed by CYP1A2 and CYP2E1 was isolated from Cinnamomi Cortex, and was identified as o-methoxycinnamaldehyde (OMCA). When phenacetin and 4-nitrophenol were used as probe substrates for CYP1A2 and CYP2E1, respectively, the OMCA was shown to be a competitive inhibitor against CYP1A2 while it was a mixed type inhibitor against CYP2E1. The inhibitory effect of OMCA on 4-nitrophenol 2-hydroxylation (K(i)=6.3 microM) was somewhat potent compared to that observed on phenacetin O-deethylation (K(i)=13.7 microM) in rat liver microsomes.

  19. Vanadate inhibition of fungal phyA and bacterial appA2 histidine acid phosphatases

    USDA-ARS?s Scientific Manuscript database

    The fungal PhyA protein, which was first identified as an acid optimum phosphomonoesterase (EC 3.1.3.8), could also serve as a vanadate haloperoxidase (EC 1.11.1.10) provided the acid phosphatase activity is shutdown by vanadate. To understand how vanadate inhibits both phytate and pNPP degrading ac...

  20. Association between Haemagglutination inhibiting antibodies and protection against clade 6B viruses in 2013 and 2015.

    PubMed

    Ng, Sophia; Saborio, Saira; Kuan, Guillermina; Gresh, Lionel; Sanchez, Nery; Ojeda, Sergio; Harris, Eva; Balmaseda, Angel; Gordon, Aubree

    2017-10-03

    The epidemiology of the pandemic A(H1N1) virus has been changing as population immunity continues to co-evolve with the virus. The impact of genetic changes in the virus on human's susceptibility is an outstanding important question in vaccine design. In a community-based study, we aim to (1) determine the genetic characteristics of 2009-2015 pandemic H1N1 viruses, (2) assess antibody response following natural infections and (3) assess the correlation of A/California/07/09 antibody titers to protection in the 2013 and 2015 epidemics. In a household transmission study, serum specimens from 253 individuals in Managua, Nicaragua were analyzed. Combined nose and throat swabs were collected to detect RT-PCR confirmed influenza infection and virus sequencing. Hemagglutination inhibition assays were performed and the protective titer for circulating H1N1pdm was determined. Clade 6B pandemic H1N1 viruses predominated in Nicaragua during the 2013 and 2015 seasons. Our household transmission study detected a household secondary attack rate of 17% in 2013 and 33% in 2015. Infected individuals, including vaccinees, showed an apparent antibody response to A/California/07/09. Baseline titers of A/California/07/09 antibodies were found to associate with protection in both seasons. A titer of ≥1:40 correlated to a 44% protection in children, a 29% protection in adults 15-49years old and a 51% protection in adults 50-85years old. In 2013 and 2015, antibody titers to A/California/07/09 associated with an infection risk reduction amongst exposed household contacts. This is consistent with a detectable vaccine effectiveness reported in a number of studies. Genetic changes in clade 6B viruses might have led to a reduced immunity in some whereas others might have been less affected. The use of human serologic data is important in virus characterization and if performed in a timely manner, could assist in vaccine strain selection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Structure-activity relationship of 2-oxoamide inhibition of group IVA cytosolic phospholipase A2 and group V secreted phospholipase A2.

    PubMed

    Six, David A; Barbayianni, Efrosini; Loukas, Vassilios; Constantinou-Kokotou, Violetta; Hadjipavlou-Litina, Dimitra; Stephens, Daren; Wong, Alan C; Magrioti, Victoria; Moutevelis-Minakakis, Panagiota; Baker, Sharon F; Dennis, Edward A; Kokotos, George

    2007-08-23

    The Group IVA cytosolic phospholipase A2 (GIVA cPLA2) is a key provider of substrates for the production of eicosanoids and platelet-activating factor. We explored the structure-activity relationship of 2-oxoamide-based compounds and GIVA cPLA2 inhibition. The most potent inhibitors are derived from delta- and gamma-amino acid-based 2-oxoamides. The optimal side-chain moiety is a short nonpolar aliphatic chain. All of the newly developed 2-oxoamides as well as those previously described have now been tested with the human Group V secreted PLA2 (GV sPLA2) and the human Group VIA calcium-independent PLA2 (GVIA iPLA2). Only one 2-oxoamide compound had appreciable inhibition of GV sPLA2, and none of the potent GIVA cPLA2 inhibitors inhibited either GV sPLA2 or GVIA iPLA2. Two of these specific GIVA cPLA2 inhibitors were also found to have potent therapeutic effects in animal models of pain and inflammation at dosages well below the control nonsteroidal anti-inflammatory drugs.

  2. Phosphodiesterase inhibition with tadalafil provides longer and sustained protection of stem cells.

    PubMed

    Haider, Husnain Kh; Lee, Yun-Jung; Jiang, Shujia; Ahmed, Rafeeq P H; Ryon, Mok; Ashraf, Muhammad

    2010-11-01

    We hypothesized that inhibition of the cGMP-specific enzyme phosphodiesterase 5A (PDE5A) promoted cGMP/protein kinase G (PKG) activity to condition stem cells for enhanced survival and proliferation. One-time tadalafil treatment (1 μM for 30 min) of mesenchymal stem cells ((Tada)MSCs) provided sustained protection of cells for 36 h. Higher cGMP activity with concomitantly increased PKG1 activity was observed in (Tada)MSCs, which peaked within 12 h after tadalafil treatment. Pretreatment with PKG1 blockers (1 μM KT-5823 or 20 nM K-252a) or transduction with adenoviral PKG1-short-hairpin RNA abolished tadalafil-induced cytoprotection of the cells. A higher proliferation rate was observed in (Tada)MSCs compared with nontreated MSCs ((Cont)MSCs). In a rat model of acute myocardial infarction, (Tada)MSCs transplanted 0 and 24 h after tadalafil treatment showed higher survival compared with (Cont)MSCs on day 2 and day 4 after engraftment. (Tada)MSCs transplanted 48 h after tadalafil treatment lost their protection on both day 2 and day 4 after engraftment, and their rate of survival was similar to (Cont)MSCs. Reduced terminal dUTP nick end-labeling positivity (P < 0.01 vs. (Cont)MSCs) and higher proliferation of (Tada)MSCs (P < 0.01 vs. (Cont)MSCs) was observed in the infarcted heart. Fluorescence immunostaining revealed neomyogenesis in both the infarct and peri-infarct areas. Blood vessel density was significantly increased in group 2 compared with group 1. Transthoracic echocardiographic heart function revealed significant preservation of the indexes of left ventricle contractility and attenuation of remodeling in (Tada)MSC-engrafted animal hearts (group 2) compared with (Cont)MSCs (group 1). PDE5A inhibition using long-acting tadalafil is an innovative approach to promote stem cell survival and proliferation in the infarcted heart.

  3. Phosphodiesterase inhibition with tadalafil provides longer and sustained protection of stem cells

    PubMed Central

    Haider, Husnain Kh; Lee, Yun-Jung; Jiang, Shujia; Ahmed, Rafeeq P. H.; Ryon, Mok

    2010-01-01

    We hypothesized that inhibition of the cGMP-specific enzyme phosphodiesterase 5A (PDE5A) promoted cGMP/protein kinase G (PKG) activity to condition stem cells for enhanced survival and proliferation. One-time tadalafil treatment (1 μM for 30 min) of mesenchymal stem cells (TadaMSCs) provided sustained protection of cells for 36 h. Higher cGMP activity with concomitantly increased PKG1 activity was observed in TadaMSCs, which peaked within 12 h after tadalafil treatment. Pretreatment with PKG1 blockers (1 μM KT-5823 or 20 nM K-252a) or transduction with adenoviral PKG1-short-hairpin RNA abolished tadalafil-induced cytoprotection of the cells. A higher proliferation rate was observed in TadaMSCs compared with nontreated MSCs (ContMSCs). In a rat model of acute myocardial infarction, TadaMSCs transplanted 0 and 24 h after tadalafil treatment showed higher survival compared with ContMSCs on day 2 and day 4 after engraftment. TadaMSCs transplanted 48 h after tadalafil treatment lost their protection on both day 2 and day 4 after engraftment, and their rate of survival was similar to ContMSCs. Reduced terminal dUTP nick end-labeling positivity (P < 0.01 vs. ContMSCs) and higher proliferation of TadaMSCs (P < 0.01 vs. ContMSCs) was observed in the infarcted heart. Fluorescence immunostaining revealed neomyogenesis in both the infarct and peri-infarct areas. Blood vessel density was significantly increased in group 2 compared with group 1. Transthoracic echocardiographic heart function revealed significant preservation of the indexes of left ventricle contractility and attenuation of remodeling in TadaMSC-engrafted animal hearts (group 2) compared with ContMSCs (group 1). PDE5A inhibition using long-acting tadalafil is an innovative approach to promote stem cell survival and proliferation in the infarcted heart. PMID:20833962

  4. Apigenin protects mice from pneumococcal pneumonia by inhibiting the cytolytic activity of pneumolysin.

    PubMed

    Song, Meng; Li, Li; Li, Meng; Cha, Yonghong; Deng, Xuming; Wang, Jianfeng

    2016-12-01

    Streptococcus pneumoniae is an important human pathogenic bacterium that can cause various life-threatening infections. Pneumolysin (PLY), the pore-forming toxin that forms large pores in the cell membrane, is a key virulence factor secreted by S. pneumoniae that penetrates the physical defenses of the host and plays an important role in the pathogenesis of pneumococcal diseases, such as pneumonia, meningitis, bacteremia and otitis media. This study showed that apigenin, one of the bioflavonoids widely found in herbs, inhibits PLY-induced hemolysis by inhibiting the oligomerization of PLY and has no anti-S. pneumoniae activity. In addition, when PLY was incubated with human alveolar epithelial (A549) cells, apigenin could effectively alleviate PLY-mediated cell injury. In vivo studies further demonstrated that apigenin could protect mice against S. pneumoniae pneumonia. These results imply that apigenin could directly interact with PLY to decrease the pathogenicity of S. pneumoniae and that novel therapeutics against S. pneumoniae PLY might provide greater effectiveness in combatting S. pneumoniae pneumonia.

  5. Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis*

    PubMed Central

    Warne, Justin; Pryce, Gareth; Hill, Julia M.; Shi, Xiao; Lennerås, Felicia; Puentes, Fabiola; Kip, Maarten; Hilditch, Laura; Walker, Paul; Simone, Michela I.; Chan, A. W. Edith; Towers, Greg J.; Coker, Alun R.; Duchen, Michael R.; Szabadkai, Gyorgy; Baker, David; Selwood, David L.

    2016-01-01

    The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use. PMID:26679998

  6. Development of an opsonin inhibition assay for evaluation of complex polysaccharide protective epitopes.

    PubMed

    McNeely, Tessie; Luo, Shengyuan; Manger, Walt; Herber, Wayne; Schofield, Tim; Tan, Charles; Newman, Kathy; Sadoff, Jerald; Donnelly, John; Cross, Alan

    2006-03-10

    The induction of opsonic antibodies directed against capsular polysaccharides (Ps) is an important mechanism by which immunization protects against the development of invasive pneumococcal (Pn) infection. In preparing Pn vaccines, it is necessary to compare different manufacturing lots of capsular Ps, or to compare oligosaccharides used for conjugate vaccines with native capsular Ps, in order to insure that important epitopes of the Ps are maintained. We have developed an opsonic-antibody inhibition assay (OIA) to compare the functional epitopes of different capsular Ps preparations in vitro. Components of the OIA are primary neutrophils, rabbit complement (C'), and type-specific antibody (Ab). After conditions for optimal opsonic killing were determined for each Pn serotype, anti-Pn Ab was pre-incubated with different dilutions of purified capsular Ps, then added to the OIA mix. Plotting the % bacteria killed versus Ps concentration (log transformed) yielded a linear curve that was used to quantify the concentration of capsular Ps which inhibited the bacteria killing by 50% (IC50). The IC50 was determined for 8 Pn Ps types. These ranged between 6 ng/ml for type 6B and 1268 ng/ml for type 23F. Importantly OIA curves were statistically identical for two different manufacturing lots of capsular Ps for the 8 Pn Ps types. We conclude that differences among capsular Ps used for Pn vaccines could be detected with an OIA assay and these differences may predict the ability of Ps preparations to induce functionally active antibody when formulated into vaccines.

  7. Ferritin protect shrimp Litopenaeus vannamei from WSSV infection by inhibiting virus replication.

    PubMed

    Ye, Ting; Wu, Xiaoting; Wu, Wenlin; Dai, Congjie; Yuan, Jianjun

    2015-01-01

    Iron is considered as an essential element for all living organisms. Therefore, limiting iron availability may be key part of the host's innate immune response to various pathogens. Ferritin is a major iron storage protein in living cells and plays an important role in iron homeostasis. One way the host can transiently reduce iron bioavailability is by ferritin over expression. In invertebrates, ferritin was found to be up-regulated after pathogens challenge and is considered to be an important element in the innate immune system. This study was designed to investigate the involvement of ferritin in shrimp Litopenaeus vannamei defense against WSSV. We discovered that the viral load of shrimp injected with recombinant ferritin protein was lower than that of control group. The suppression of ferritin by dsRNA increased susceptibility to WSSV with 3-fold high viral copies. The present study documented that ferritin protected shrimp L. vannamei from WSSV by inhibiting virus replication. We presume that ferritin reduce iron availability, leading to inhibit the activity of ribonucleotide reductase and delay the replication of virus genome. This study provided new insights into the understanding of molecular responses and defense mechanisms in shrimp against WSSV.

  8. Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis.

    PubMed

    Warne, Justin; Pryce, Gareth; Hill, Julia M; Shi, Xiao; Lennerås, Felicia; Puentes, Fabiola; Kip, Maarten; Hilditch, Laura; Walker, Paul; Simone, Michela I; Chan, A W Edith; Towers, Greg J; Coker, Alun R; Duchen, Michael R; Szabadkai, Gyorgy; Baker, David; Selwood, David L

    2016-02-26

    The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use.

  9. Inhibition of Cytohesins Protects against Genetic Models of Motor Neuron Disease

    PubMed Central

    Zhai, Jinbin; Zhang, Lei; Mojsilovic-Petrovic, Jelena; Jian, Xiaoying; Thomas, Jeffrey; Homma, Kengo; Schmitz, Anton; Famulok, Michael; Ichijo, Hidenori; Argon, Yair; Randazzo, Paul A.

    2015-01-01

    Mutant genes that underlie Mendelian forms of amyotrophic lateral sclerosis (ALS) and biochemical investigations of genetic disease models point to potential driver pathophysiological events involving endoplasmic reticulum (ER) stress and autophagy. Several steps in these cell biological processes are known to be controlled physiologically by small ADP-ribosylation factor (ARF) signaling. Here, we investigated the role of ARF guanine nucleotide exchange factors (GEFs), cytohesins, in models of ALS. Genetic or pharmacological inhibition of cytohesins protects motor neurons in vitro from proteotoxic insults and rescues locomotor defects in a Caenorhabditis elegans model of disease. Cytohesins form a complex with mutant superoxide dismutase 1 (SOD1), a known cause of familial ALS, but this is not associated with a change in GEF activity or ARF activation. ER stress evoked by mutant SOD1 expression is alleviated by antagonism of cytohesin activity. In the setting of mutant SOD1 toxicity, inhibition of cytohesin activity enhances autophagic flux and reduces the burden of misfolded SOD1. These observations suggest that targeting cytohesins may have potential benefits for the treatment of ALS. PMID:26085633

  10. NF-κB Inhibition Protects against Tumor-Induced Cardiac Atrophy in Vivo

    PubMed Central

    Wysong, Ashley; Couch, Marion; Shadfar, Scott; Li, Lugi; Rodriguez, Jessica E.; Asher, Scott; Yin, Xiaoying; Gore, Mitchell; Baldwin, Al; Patterson, Cam; Willis, Monte S.

    2011-01-01

    Cancer cachexia is a severe wasting syndrome characterized by the progressive loss of lean body mass and systemic inflammation. It occurs in approximately 80% of patients with advanced malignancy and is the cause of 20% to 30% of all cancer-related deaths. The mechanism by which striated muscle loss occurs is the tumor release of pro-inflammatory cytokines, such as IL-1, IL-6, and TNF-α. These cytokines interact with their cognate receptors on muscle cells to enhance NF-κB signaling, which then mediates muscle loss and significant cardiac dysfunction. Genetic inhibition of NF-κB signaling has demonstrated its predominant role in skeletal muscle loss. Therefore, we tested two novel drugs designed to specifically inhibit NF-κB by targeting the IκB kinase (IKK) complex: Compound A and NEMO binding domain (NBD) peptide. Using an established mouse model of cancer cachexia (C26 adenocarcinoma), we determined how these drugs affected the development of tumor-induced cardiac atrophy and function. Echocardiographic and histological analysis revealed that both Compound A and NBD inhibit cardiac NF-κB activity and prevent the development of tumor-induced systolic dysfunction and atrophy. This protection was independent of any effects of the tumor itself (Compound A) or tumor-secreted cytokines (NBD). This study identifies for the first time, to our knowledge, that drugs targeting the IKK complex are cardioprotective against cancer cachexia–induced cardiac atrophy and systolic dysfunction, suggesting therapies that may help reduce cardiac-associated morbidities found in patients with advanced malignancies. PMID:21356358

  11. NF-κB inhibition protects against tumor-induced cardiac atrophy in vivo.

    PubMed

    Wysong, Ashley; Couch, Marion; Shadfar, Scott; Li, Luge; Li, Lugi; Rodriguez, Jessica E; Asher, Scott; Yin, Xiaoying; Gore, Mitchell; Baldwin, Al; Patterson, Cam; Willis, Monte S

    2011-03-01

    Cancer cachexia is a severe wasting syndrome characterized by the progressive loss of lean body mass and systemic inflammation. It occurs in approximately 80% of patients with advanced malignancy and is the cause of 20% to 30% of all cancer-related deaths. The mechanism by which striated muscle loss occurs is the tumor release of pro-inflammatory cytokines, such as IL-1, IL-6, and TNF-α. These cytokines interact with their cognate receptors on muscle cells to enhance NF-κB signaling, which then mediates muscle loss and significant cardiac dysfunction. Genetic inhibition of NF-κB signaling has demonstrated its predominant role in skeletal muscle loss. Therefore, we tested two novel drugs designed to specifically inhibit NF-κB by targeting the IκB kinase (IKK) complex: Compound A and NEMO binding domain (NBD) peptide. Using an established mouse model of cancer cachexia (C26 adenocarcinoma), we determined how these drugs affected the development of tumor-induced cardiac atrophy and function. Echocardiographic and histological analysis revealed that both Compound A and NBD inhibit cardiac NF-κB activity and prevent the development of tumor-induced systolic dysfunction and atrophy. This protection was independent of any effects of the tumor itself (Compound A) or tumor-secreted cytokines (NBD). This study identifies for the first time, to our knowledge, that drugs targeting the IKK complex are cardioprotective against cancer cachexia-induced cardiac atrophy and systolic dysfunction, suggesting therapies that may help reduce cardiac-associated morbidities found in patients with advanced malignancies. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  12. Micropatterned Protective Membranes Inhibit Lens Epithelial Cell Migration in Posterior Capsule Opacification Model.

    PubMed

    Magin, Chelsea M; May, Rhea M; Drinker, Michael C; Cuevas, Kevin H; Brennan, Anthony B; Reddy, Shravanthi T

    2015-03-01

    To evaluate the ability of Sharklet (SK) micropatterns to inhibit lens epithelial cell (LEC) migration. Sharklet Technologies, Inc. (STI) and InSight Innovations, LLC have proposed to develop a Sharklet-patterned protective membrane (PM) to be implanted in combination with a posterior chamber intraocular lens (IOL) to inhibit cellular migration across the posterior capsule, and thereby reduce rates of posterior capsular opacification (PCO). A variety of STI micropatterns were evaluated versus smooth (SM) controls in a modified scratch wound assay for the ability to reduce or inhibit LEC migration. The best performing topography was selected, translated to a radial design, and applied to PM prototypes. The PM prototypes were tested in an in vitro PCO model for reduction of cell migration behind an IOL versus unpatterned prototypes and IOLs with no PM. In both assays, cell migration was analyzed with fluorescent microscopy. All SK micropatterns significantly reduced LEC migration compared with SM controls. Micropatterns that protruded from the surface reduced migration more than recessed features. The best performing micropattern reduced LEC coverage by 80%, P = 0.0001 (ANOVA, Tukey Test). Micropatterned PMs reduced LEC migration in a PCO model by 50%, P = 0.0005 (ANOVA, Tukey Test) compared with both IOLs with no PM and IOLs with SM PMs. Collectively, in vitro results indicate the implantation of micropatterned PMs in combination with posterior chamber IOLs could significantly reduce rates of clinically relevant PCO. This innovative technology is a globally accessible solution to high PCO rates. A novel IOL incorporating the SK micropattern in a membrane design surrounding the optic may help increase the success of cataract surgery by reducing secondary cataract, or PCO.

  13. Micropatterned Protective Membranes Inhibit Lens Epithelial Cell Migration in Posterior Capsule Opacification Model

    PubMed Central

    Magin, Chelsea M.; May, Rhea M.; Drinker, Michael C.; Cuevas, Kevin H.; Brennan, Anthony B.; Reddy, Shravanthi T.

    2015-01-01

    Purpose To evaluate the ability of Sharklet (SK) micropatterns to inhibit lens epithelial cell (LEC) migration. Sharklet Technologies, Inc. (STI) and InSight Innovations, LLC have proposed to develop a Sharklet-patterned protective membrane (PM) to be implanted in combination with a posterior chamber intraocular lens (IOL) to inhibit cellular migration across the posterior capsule, and thereby reduce rates of posterior capsular opacification (PCO). Methods A variety of STI micropatterns were evaluated versus smooth (SM) controls in a modified scratch wound assay for the ability to reduce or inhibit LEC migration. The best performing topography was selected, translated to a radial design, and applied to PM prototypes. The PM prototypes were tested in an in vitro PCO model for reduction of cell migration behind an IOL versus unpatterned prototypes and IOLs with no PM. In both assays, cell migration was analyzed with fluorescent microscopy. Results All SK micropatterns significantly reduced LEC migration compared with SM controls. Micropatterns that protruded from the surface reduced migration more than recessed features. The best performing micropattern reduced LEC coverage by 80%, P = 0.0001 (ANOVA, Tukey Test). Micropatterned PMs reduced LEC migration in a PCO model by 50%, P = 0.0005 (ANOVA, Tukey Test) compared with both IOLs with no PM and IOLs with SM PMs. Conclusions Collectively, in vitro results indicate the implantation of micropatterned PMs in combination with posterior chamber IOLs could significantly reduce rates of clinically relevant PCO. This innovative technology is a globally accessible solution to high PCO rates. Translational Relevance A novel IOL incorporating the SK micropattern in a membrane design surrounding the optic may help increase the success of cataract surgery by reducing secondary cataract, or PCO. PMID:25883876

  14. Inhibition of Rho Kinase (ROCK) Leads to Increased Cerebral Blood Flow and Stroke Protection

    PubMed Central

    Rikitake, Yoshiyuki; Kim, Hyung-Hwan; Huang, Zhihong; Seto, Minoru; Yano, Kazuo; Asano, Toshio; Moskowitz, Michael A.; Liao, James K.

    2009-01-01

    Background and Purpose Endothelium-derived nitric oxide (NO) plays a pivotal role in vascular protection. The Rho kinase (ROCK) inhibitor, hydroxyfasudil, prevents the downregulation of endothelial NO synthase (eNOS) under hypoxic conditions. However, it is unknown whether inhibition of ROCK can attenuate ischemia-induced endothelial dysfunction and tissue damage in vivo. Methods Human vascular endothelial cells were treated with increasing concentrations of hydroxyfasudil (0.1 to 100 μmol/L) and eNOS expression and activity were measured. To determine the physiological relevance of eNOS regulation by ROCK, we administered fasudil, which is metabolized to hydroxyfasudil in vivo, to mice for 2 days before subjecting them to middle cerebral artery occlusion. Cerebral blood flow, cerebral infarct size, and neurologic deficit were measured. Results In a concentration-dependent manner, hydroxyfasudil increased eNOS mRNA and protein expression, resulting in a 1.9- and 1.6-fold increase, respectively, at 10 μmol/L (P<0.05 for both). This correlated with a 1.5- and 2.3-fold increase in eNOS activity and NO production, respectively (P<0.05 for both). Fasudil increased cerebral blood flow to both ischemic and nonischemic brain areas, reduced cerebral infarct size by 33%, and improved neurologic deficit score by 37% (P<0.05). This correlated with inhibition of brain and vascular ROCK activity and increased eNOS expression and activity. Another ROCK inhibitor, Y-27632, also showed similar effects. The neuroprotective effects of fasudil were absent in eNOS-deficient mice. Conclusions These findings indicate that the neuroprotective effect of ROCK inhibition is mediated by endothelium-derived NO and suggest that ROCK may be an important therapeutic target for ischemic stroke. PMID:16141422

  15. Hydrogen sulfide [corrected] increases survival during sepsis: protective effect of CHOP inhibition.

    PubMed

    Ferlito, Marcella; Wang, Qihong; Fulton, William B; Colombani, Paul M; Marchionni, Luigi; Fox-Talbot, Karen; Paolocci, Nazareno; Steenbergen, Charles

    2014-02-15

    Sepsis is a major cause of mortality, and dysregulation of the immune response plays a central role in this syndrome. H2S, a recently discovered gaso-transmitter, is endogenously generated by many cell types, regulating a number of physiologic processes and pathophysiologic conditions. We report that H2S increased survival after experimental sepsis induced by cecal ligation and puncture (CLP) in mice. Exogenous H2S decreased the systemic inflammatory response, reduced apoptosis in the spleen, and accelerated bacterial eradication. We found that C/EBP homologous protein 10 (CHOP), a mediator of the endoplasmic reticulum stress response, was elevated in several organs after CLP, and its expression was inhibited by H2S treatment. Using CHOP-knockout (KO) mice, we demonstrated for the first time, to our knowledge, that genetic deletion of Chop increased survival after LPS injection or CLP. CHOP-KO mice displayed diminished splenic caspase-3 activation and apoptosis, decreased cytokine production, and augmented bacterial clearance. Furthermore, septic CHOP-KO mice treated with H2S showed no additive survival benefit compared with septic CHOP-KO mice. Finally, we showed that H2S inhibited CHOP expression in macrophages by a mechanism involving Nrf2 activation. In conclusion, our findings show a protective effect of H2S treatment afforded, at least partially, by inhibition of CHOP expression. The data reveal a major negative role for the transcription factor CHOP in overall survival during sepsis and suggest a new target for clinical intervention, as well potential strategies for treatment.

  16. INHIBITION OF HUMAN AND RAT CYP1A2 BY TCDD AND DIOXIN-LIKE CHEMICALS

    EPA Science Inventory

    Dioxins have been shown to bind and induce rodent CYP1A2, producing a dose-dependent hepatic sequestration in vivo. The induction of CYP1A2 activity has been used as a noninvasive biomarker for human exposure to dioxins; while there is a consistent relationship between exposure ...

  17. INHIBITION OF HUMAN AND RAT CYP1A2 BY TCDD AND DIOXIN-LIKE CHEMICALS

    EPA Science Inventory

    Dioxins have been shown to bind and induce rodent CYP1A2, producing a dose-dependent hepatic sequestration in vivo. The induction of CYP1A2 activity has been used as a noninvasive biomarker for human exposure to dioxins; while there is a consistent relationship between exposure ...

  18. Biofilm, ice recrystallization inhibition and freeze-thaw protection in an epiphyte community.

    PubMed

    Wu, Z; Kan, F W K; She, Y-M; Walker, V K

    2012-01-01

    Microbial communities found on the surface of overwintering plants may be exposed to low temperatures as well as multiple freeze-thaw events. To explore the adaptive mechanisms of these epiphytes, with the objective of identifying products for freeze-protection, enrichment libraries were made from frost-exposed leaves. Of 15 identified bacteria from 60 individual clones, approximately half had ice-association activities, with the great majority showing high freeze-thaw resistance. Isolates with ice nucleation activity and ice recrystallization inhibition activity were recovered. Of the latter, two (Erwinia billingiae J10, and Sphingobacterium kitahiroshimense Y2) showed culture and electron microscopic evidence of motility and/or biofilm production. Mass spectrometric characterization of the E. billingiae extracellular polymeric substance (EPS) identified the major proteins as 35 kDa outer membrane protein A and F, supporting its biofilm character. The addition of the EPS preparation increased the freeze-thaw survival of the more susceptible bacteria 1000-10000 times, and protection was at least partially dependent on the protein component.

  19. Allicin protects against cisplatin-induced vestibular dysfunction by inhibiting the apoptotic pathway.

    PubMed

    Wu, Xianmin; Cai, Jing; Li, Xiaofei; Li, He; Li, Jianfeng; Bai, Xiaohui; Liu, Wenwen; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo; Fan, Zhaomin

    2017-03-01

    Cisplatin is an anticancer drug that causes the impairment of inner ear function as side effects, including hearing loss and balance dysfunction. The purpose of this study was to investigate the effects of allicin against cisplatin-induced vestibular dysfunction in mice and to make clear the mechanism underlying the protective effects of allicin on oto-vestibulotoxicity. Mice intraperitoneally injected with cisplatin exhibited vestibular dysfunction in swimming test, which agreed with impairment in vestibule. However, these impairments were significantly prevented by pre-treatment with allicin. Allicin markedly reduced cisplatin-activated expression of cleaved-caspase-3 in hair cells and vascular layer cells of utricule, saccule and ampulla, but also decreased AIF nuclear translocation of hair cells in utricule, saccule and ampulla. These results showed that allicin played an effective role in protecting vestibular dysfunction induced by cisplatin via inhibiting caspase-dependent and caspase-independent apoptotic pathways. Therefore, allicin may be useful in preventing oto-vestibulotoxicity mediated by cisplatin.

  20. Baicalin Inhibits Renal Cell Apoptosis and Protects Against Acute Kidney Injury in Pediatric Sepsis

    PubMed Central

    Zhu, Yanping; Fu, Yanxia; Lin, Hairong

    2016-01-01

    Background Pediatric sepsis has high morbidity in children, may lead to acute kidney injury (AKI), and further aggravate the disease. Baicalin is a kind of flavonoid in Scutellaria baicalensis Georgi and has been reported to protect against several diseases, but its roles in septic AKI remain unclear. This study aimed to uncover the effects of baicalin in AKI during pediatric sepsis. Material/Methods Blood urea nitrogen (BUN) and serum creatinine (Cr) levels were detected in 50 pediatric patients, who underwent basic therapy with or without baicalin adjunctive therapy. Mouse sepsis models were constructed by cecal ligation and puncture (CLP) and treated with baicalin intragastrically, after which BUN and Cr examination, TUNEL apoptosis assay, and expression analyses of BAX and BCL2 were performed. Results Baicalin adjunctive therapy significantly decreased BUN and Cr levels in pediatric sepsis patients (P<0.05). CLP led to elevated BUN and Cr levels in the mouse model (P<0.01), indicating kidney injury accompanied by sepsis. Baicalin decreased BUN and Cr levels (P<0.05), and reduced the apoptotic cell percent in the renal tissue (P<0.05) of the CLP model. It inhibited BAX and promoted BCL2 in the renal tissue, which was consistent with cell apoptosis changes. Conclusions Baicalin is capable of suppressing renal cell apoptosis and protecting against AKI in pediatric sepsis. This study provides a potential adjunctive therapy for treating AKI in pediatric sepsis, and further research is necessary to reveal its deeper mechanisms. PMID:28013315

  1. Protection from mitochondrial complex II inhibition in vitro and in vivo by Nrf2-mediated transcription.

    PubMed

    Calkins, Marcus J; Jakel, Rebekah J; Johnson, Delinda A; Chan, Kaimin; Kan, Yuet Wai; Johnson, Jeffrey A

    2005-01-04

    Complex II inhibitors 3-nitropropionic acid (3NP) and malonate cause striatal damage reminiscent of Huntington's disease and have been shown to involve oxidative stress in their pathogenesis. Because nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent transcriptional activation by means of the antioxidant response element is known to coordinate the up-regulation of cytoprotective genes involved in combating oxidative stress, we investigated the significance of Nrf2 in complex II-induced toxicity. We found that Nrf2-deficient cells and Nrf2 knockout mice are significantly more vulnerable to malonate and 3NP and demonstrate increased antioxidant response element (ARE)-regulated transcription mediated by astrocytes. Furthermore, ARE preactivation by means of intrastriatal transplantation of Nrf2-overexpressing astrocytes before lesioning conferred dramatic protection against complex II inhibition. These observations implicate Nrf2 as an essential inducible factor in the protection against complex II inhibitor-mediated neurotoxicity. These data also introduce Nrf2-mediated ARE transcription as a potential target of preventative therapy in neurodegenerative disorders such as Huntington's disease.

  2. Phycocyanin and phycocyanobilin from Spirulina platensis protect against diabetic nephropathy by inhibiting oxidative stress.

    PubMed

    Zheng, Jing; Inoguchi, Toyoshi; Sasaki, Shuji; Maeda, Yasutaka; McCarty, Mark F; Fujii, Masakazu; Ikeda, Noriko; Kobayashi, Kunihisa; Sonoda, Noriyuki; Takayanagi, Ryoichi

    2013-01-15

    We and other investigators have reported that bilirubin and its precursor biliverdin may have beneficial effects on diabetic vascular complications, including nephropathy, via its antioxidant effects. Here, we investigated whether phycocyanin derived from Spirulina platensis, a blue-green algae, and its chromophore phycocyanobilin, which has a chemical structure similar to that of biliverdin, protect against oxidative stress and renal dysfunction in db/db mice, a rodent model for Type 2 diabetes. Oral administration of phycocyanin (300 mg/kg) for 10 wk protected against albuminuria and renal mesangial expansion in db/db mice, and normalized tumor growth factor-β and fibronectin expression. Phycocyanin also normalized urinary and renal oxidative stress markers and the expression of NAD(P)H oxidase components. Similar antioxidant effects were observed following oral administration of phycocyanobilin (15 mg/kg) for 2 wk. Phycocyanobilin, bilirubin, and biliverdin also inhibited NADPH dependent superoxide production in cultured renal mesangial cells. In conclusion, oral administration of phycocyanin and phycocyanobilin may offer a novel and feasible therapeutic approach for preventing diabetic nephropathy.

  3. Cardio-Protection of Salvianolic Acid B through Inhibition of Apoptosis Network

    PubMed Central

    Xu, Lingling; Deng, Yanping; Feng, Lixin; Li, Defang; Chen, Xiaoyan; Ma, Chao; Liu, Xuan; Yin, Jun; Yang, Min; Teng, Fukang; Wu, Wanying; Guan, Shuhong; Jiang, Baohong; Guo, Dean

    2011-01-01

    Targeting cellular function as a system rather than on the level of the single target significantly increases therapeutic potency. In the present study, we detect the target pathway of salvianolic acid B (SalB) in vivo. Acute myocardial infarction (AMI) was induced in rats followed by the treatment with 10 mg/kg SalB. Hemodynamic detection and pathological stain, 2-dimensional electrophoresis, MALDI-TOF MS/MS, Western blot, pathway identification, apoptosis assay and transmission electron microscope were used to elucidate the effects and mechanism of SalB on cardioprotection. Higher SalB concentration was found in ischemic area compared to no-ischemic area of heart, correlating with improved heart function and histological structure. Thirty-three proteins regulated by SalB in AMI rats were identified by biochemical analysis and were classified as the components of metabolism and apoptosis networks. SalB protected cardiomyocytes from apoptosis, inhibited poly (ADP-ribose) polymerase-1 pathway, and improved the integrity of mitochondrial and nucleus of heart tissue during AMI. Furthermore, the protective effects of SalB against apoptosis were verified in H9c2 cells. Our results provide evidence that SalB regulates multi-targets involved in the apoptosis pathway during AMI and therefore may be a candidate for novel therapeutics of heart diseases. PMID:21915278

  4. Genetic and pharmacological inhibition of dimethylarginine dimethylaminohydrolase 1 is protective in endotoxic shock.

    PubMed

    Nandi, Manasi; Kelly, Peter; Torondel, Belen; Wang, Zhen; Starr, Anna; Ma, Yue; Cunningham, Philip; Stidwill, Raymond; Leiper, James

    2012-11-01

    The overproduction of vascular NO contributes toward the circulatory collapse observed in patients with septic shock. Dimethylarginine dimethylaminohydrolase (DDAH), which has 2 isoforms, metabolizes asymmetrically methylated arginines (asymmetric mono- or di-methylarginine), endogenously produced NO synthase inhibitors. We wished to investigate whether reducing DDAH1 activity, using genetic and pharmacological approaches, is protective during lipopolysaccharide-induced endotoxic shock. Experiments were conducted in DDAH1 heterozygous knockout mice (DDAH1(+/-)) or naive rats treated with a synthetic pharmacological DDAH inhibitor (L-257). We demonstrate for the first time that L-257 is DDAH1 selective using recombinant human DDAH proteins. DDAH1 mRNA was expressed in aortic but not macrophage cDNA, and consistent with this expression profile, L-257 selectively inhibited NO production from lipopolysaccharide-treated aorta but not macrophages, in culture. Conscious and anesthetized cardiovascular hemodynamics were monitored using implanted radiotelemetry devices or invasive catheters, respectively. Lipopolysaccharide was administered intravenously to model endotoxemia, and all animals presented with circulatory shock. DDAH1(+/-) mice or L-257-treated rats displayed attenuation in the rate of developed hypotension compared with wild-type littermates or vehicle control animals, respectively. Pharmacological and genetic reduction of DDAH1 activity is protective against the vascular changes observed during endotoxic shock.

  5. Sclareol protects Staphylococcus aureus-induced lung cell injury via inhibiting alpha-hemolysin expression.

    PubMed

    Ouyang, Ping; Sun, Mao; He, Xuewen; Wang, Kaiyu; Yin, Zhongqiong; Fu, Hualin; Li, Yinglun; Geng, Yi; Shu, Gang; He, Changliang; Liang, Xiaoxia; Lai, Weiming; Li, Lixia; Zou, Yuanfeng; Song, Xu; Yin, Lizi

    2016-09-23

    Staphylococcus aureus (S. aureus) is a common Gram-positive bacterium that causes serious infections in human and animals. With the continuous emergence of the methicillin-resistant S. aureus (MRSA) strains, antibiotics have limited efficacy in treating MRSA infections. Accordingly, novel agents that act on new targets are desperately needed to combat these infections. S. aureus alpha-hemolysin plays an indispensable role in its pathogenicity. In this study, we demonstrate that sclareol, a fragrant chemical compound found in clary sage, can prominently decrease alpha-hemolysin secretion in S. aureus strain USA300 at sub-inhibitory concentrations. Hemolysis assays, western-blotting and RT-PCR were used to detect the production of alpha-hemolysin in the culture supernatant. When USA300 was co-cultured with and A549 epithelial cells, sclareol could protect A549 cells at a final concentration of 8 µg/ml. The protective capability of sclareol against the USA300-mediated injury of A549 cells was further shown by cytotoxicity assays and live/dead analysis. In conclusion, sclareol was shown to inhibit the production of S. aureus alpha-hemolysin. Sclareol has potential for development as a new agent to treat S. aureus infections.

  6. BDNF/TrkB signaling protects HT-29 human colon cancer cells from EGFR inhibition

    SciTech Connect

    Brunetto de Farias, Caroline; Heinen, Tiago Elias; Pereira dos Santos, Rafael; Abujamra, Ana Lucia; Schwartsmann, Gilberto; and others

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer BDNF protected HT-29 colorectal cancer cells from the antitumor effect of cetuximab. Black-Right-Pointing-Pointer TrkB inhibition potentiated the antitumor effect of cetuximab. Black-Right-Pointing-Pointer BDNF/TrkB signaling might be involved in resistance to anti-EGFR therapy. -- Abstract: The clinical success of targeted treatment of colorectal cancer (CRC) is often limited by resistance to anti-epidermal growth factor receptor (EGFR) therapy. The neurotrophin brain-derived neurotrophic factor (BDNF) and its receptor TrkB have recently emerged as anticancer targets, and we have previously shown increased BDNF levels in CRC tumor samples. Here we report the findings from in vitro experiments suggesting that BDNF/TrkB signaling can protect CRC cells from the antitumor effects of EGFR blockade. The anti-EGFR monoclonal antibody cetuximab reduced both cell proliferation and the mRNA expression of BDNF and TrkB in human HT-29 CRC cells. The inhibitory effect of cetuximab on cell proliferation and survival was counteracted by the addition of human recombinant BDNF. Finally, the Trk inhibitor K252a synergistically enhanced the effect of cetuximab on cell proliferation, and this effect was blocked by BDNF. These results provide the first evidence that increased BDNF/TrkB signaling might play a role in resistance to EGFR blockade. Moreover, it is possible that targeting TrkB could potentiate the anticancer effects of anti-EGFR therapy.

  7. Geldanamycin mediates the apoptosis of gastric carcinoma cells through inhibition of EphA2 protein expression.

    PubMed

    Wang, Da-Hu; Zhang, Yu-Jun; Zhang, San-Bing; Liu, Hui; Liu, Liang; Liu, Feng-Ling; Zuo, Jing

    2014-12-01

    The aim of the present study was to investigate the role of EphA2 in the carcinogenesis and progression of gastric carcinoma. Moreover, we aimed to determine the effect of geldanamycin (GA), an inhibitor of Hsp90, on the proliferation and apoptosis of human gastric carcinoma cells. Gastric carcinoma tissues, paired adjacent mucosa and paired normal mucosa were obtained from resected surgical specimens of gastric carcinoma, and EphA2 mRNA and protein levels were assessed by RT-PCR, immunohistochemistry and western blot analysis. FCM was used to detect cell cycle distribution and apoptosis. MGC803 cell proliferation and apoptosis were assessed by MTT and FCM, respectively. We found that EphA2 protein was increased in the carcinogenesis of gastric epithelial cells. Proliferation index (PI) was significantly upregulated following an increase in EphA2 expression in gastric carcinoma compared with dysplasia and normal samples, and was notably correlated with grade and lymph node metastasis. Knockdown of EphA2 increased the apoptosis rate and decreased the PI of MGC803 cells, which overexpressed the EphA2 protein. GA inhibited the cell proliferation of MGC803 cells in a dose- and time-dependent manner and induced cell apoptosis. In addition, GA decreased the EphA2 protein expression in MGC803 cells. Overexpression of EphA2 inhibited cell growth, blocked cells in the G0/G1 stage and increased cell apoptosis induced by GA in MGC803 cells. However, knockdown of EphA2 in MGC803 cells increased the apoptosis ratio induced by GA. In conclusion, EphA2 overexpression is an important characteristic in the carcinogenesis of gastric epithelial cells, followed by an increase in apoptosis and cell cycle arrest. Knockdown of EphA2 blocked MGC803 cell proliferation and induced cell apoptosis. In conclusion GA inhibits MGC803 cell proliferation and induces cell apoptosis by upregulating expression of EphA2.

  8. Competitive inhibition of cytosolic Ca2+-dependent phospholipase A2 by acteoside in RBL-2H3 cells.

    PubMed

    Song, Ho Sun; Choi, Mi Young; Ko, Myoung Soo; Jeong, Jae Min; Kim, Yong Ho; Jang, Beom Hyeon; Sung, Ji Hoon; Kim, Min Gyu; Whang, Wan Kyunn; Sim, Sang Soo

    2012-05-01

    The aim of this study was to investigate whether acteoside isolated from Clerodendron trichotomum Thunberg may act as a selective inhibitor of phospholipase A(2) in RBL-2H3 cells. Acteoside dose-dependently inhibited 0.5 μM melittin-induced release of [(3)H]arachidonic acid, which was due to the inhibition of cytosolic Ca(2+)-dependent phospholipase A(2) (cPLA(2)) rather than secretory PLA(2) (sPLA(2)). In Dixon plots, the apparent K ( i ) value of acteoside on cPLA(2) was 5.9 μM and the inhibitory pattern appeared to be a competitive inhibitor. The above data, suggests that acteoside acts as a competitive inhibitor of cPLA(2) in RBL-2H3 cells.

  9. Annexin A2 Enhances Complement Activation by Inhibiting Factor H1

    PubMed Central

    Renner, Brandon; Tong, Hua Hua; Laskowski, Jennifer; Jonscher, Karen; Goetz, Lindsey; Woolaver, Rachel; Hannan, Jonathan; Li, Yong Xing; Hourcade, Dennis; Pickering, Matthew C.; Holers, V. Michael; Thurman, Joshua M.

    2015-01-01

    Factor H is a circulating protein that regulates activation of the alternative pathway (AP) of complement. Mutations and genetic variations of factor H are associated with several AP-mediated diseases, highlighting the critical role of factor H in AP regulation. AP-mediated inflammation is typically triggered by illness or tissue injury, however, and tissue injury can trigger AP activation in individuals with fully functional factor H. This suggests that factor H function is affected by local conditions within tissues. We hypothesized that inducible proteins impair the ability of factor H to locally control the AP, thereby increasing AP activation. We used purified murine factor H to immunoprecipitate binding partners from mouse kidneys. Using immunoaffinity liquid chromatography-mass spectrometry we then identified annexin A2 as a factor H binding partner. Further experiments showed that annexin A2 reduces the binding of factor H to cell surfaces. Recombinant annexin A2 impaired complement regulation by factor H, and increased complement activation on renal cell surfaces in vitro and in vivo. In a murine model of acute pneumococcal otitis media the administration of annexin A2 increased AP-mediated bacterial opsonization and clearance. In conclusion, the local production of annexin A2 within tissues suppresses regulation of the AP by factor H. Annexin A2 can contribute to AP-mediated tissue inflammation by locally impairing factor H function, but annexin A2 can also improve complement-mediated bacterial clearance. PMID:26729803

  10. Orphan nuclear receptor NR4A2 inhibits hepatic stellate cell proliferation through MAPK pathway in liver fibrosis.

    PubMed

    Chen, Pengguo; Li, Jie; Huo, Yan; Lu, Jin; Wan, Lili; Li, Bin; Gan, Run; Guo, Cheng

    2015-01-01

    Hepatic stellate cells (HSCs) play a crucial role in liver fibrosis, which is a pathological process characterized by extracellular matrix accumulation. NR4A2 is a nuclear receptor belonging to the NR4A subfamily and vital in regulating cell growth, metabolism, inflammation and other biological functions. However, its role in HSCs is unclear. We analyzed NR4A2 expression in fibrotic liver and stimulated HSCs compared with control group and studied the influence on cell proliferation, cell cycle, cell apoptosis and MAPK pathway after NR4A2 knockdown. NR4A2 expression was examined by real-time polymerase chain reaction, Western blotting, immunohistochemistry and immunofluorescence analyses. NR4A2 expression was significantly lower in fibrotic liver tissues and PDGF BB or TGF-β stimulated HSCs compared with control group. After NR4A2 knockdown α-smooth muscle actin and Col1 expression increased. In addition, NR4A2 silencing led to the promotion of cell proliferation, increase of cell percentage in S phase and reduced phosphorylation of ERK1/2, P38 and JNK in HSCs. These results indicate that NR4A2 can inhibit HSC proliferation through MAPK pathway and decrease extracellular matrix in liver fibrogenesis. NR4A2 may be a promising therapeutic target for liver fibrosis.

  11. Clinical and parasitological protection in a Leishmania infantum-macaque model vaccinated with adenovirus and the recombinant A2 antigen.

    PubMed

    Grimaldi, Gabriel; Teva, Antonio; Porrozzi, Renato; Pinto, Marcelo A; Marchevsky, Renato S; Rocha, Maria Gabrielle L; Dutra, Miriam S; Bruña-Romero, Oscar; Fernandes, Ana-Paula; Gazzinelli, Ricardo T

    2014-06-01

    Visceral leishmaniasis (VL) is a severe vector-born disease of humans and dogs caused by Leishmania donovani complex parasites. Approximately 0.2 to 0.4 million new human VL cases occur annually worldwide. In the new world, these alarming numbers are primarily due to the impracticality of current control methods based on vector reduction and dog euthanasia. Thus, a prophylactic vaccine appears to be essential for VL control. The current efforts to develop an efficacious vaccine include the use of animal models that are as close to human VL. We have previously reported a L. infantum-macaque infection model that is reliable to determine which vaccine candidates are most worthy for further development. Among the few amastigote antigens tested so far, one of specific interest is the recombinant A2 (rA2) protein that protects against experimental L. infantum infections in mice and dogs. Primates were vaccinated using three rA2-based prime-boost immunization regimes: three doses of rA2 plus recombinant human interleukin-12 (rhIL-12) adsorbed in alum (rA2/rhIL-12/alum); two doses of non-replicative adenovirus recombinant vector encoding A2 (Ad5-A2) followed by two boosts with rA2/rhIL-12/alum (Ad5-A2+rA2/rhIL12/alum); and plasmid DNA encoding A2 gene (DNA-A2) boosted with two doses of Ad5-A2 (DNA-A2+Ad5-A2). Primates received a subsequent infectious challenge with L. infantum. Vaccines, apart from being safe, were immunogenic as animals responded with increased pre-challenge production of anti-A2-specific IgG antibodies, though with some variability in the response, depending on the vaccine formulation/protocol. The relative parasite load in the liver was significantly lower in immunized macaques as compared to controls. Protection correlated with hepatic granuloma resolution, and reduction of clinical symptoms, particularly when primates were vaccinated with the Ad5-A2+rA2/rhIL12/alum protocol. The remarkable clinical protection induced by A2 in an animal model that is

  12. Clinical and Parasitological Protection in a Leishmania infantum-Macaque Model Vaccinated with Adenovirus and the Recombinant A2 Antigen

    PubMed Central

    Grimaldi, Gabriel; Teva, Antonio; Porrozzi, Renato; Pinto, Marcelo A.; Marchevsky, Renato S.; Rocha, Maria Gabrielle L.; Dutra, Miriam S.; Bruña-Romero, Oscar; Fernandes, Ana-Paula; Gazzinelli, Ricardo T.

    2014-01-01

    Background Visceral leishmaniasis (VL) is a severe vector-born disease of humans and dogs caused by Leishmania donovani complex parasites. Approximately 0.2 to 0.4 million new human VL cases occur annually worldwide. In the new world, these alarming numbers are primarily due to the impracticality of current control methods based on vector reduction and dog euthanasia. Thus, a prophylactic vaccine appears to be essential for VL control. The current efforts to develop an efficacious vaccine include the use of animal models that are as close to human VL. We have previously reported a L. infantum-macaque infection model that is reliable to determine which vaccine candidates are most worthy for further development. Among the few amastigote antigens tested so far, one of specific interest is the recombinant A2 (rA2) protein that protects against experimental L. infantum infections in mice and dogs. Methodology/Principal Findings Primates were vaccinated using three rA2-based prime-boost immunization regimes: three doses of rA2 plus recombinant human interleukin-12 (rhIL-12) adsorbed in alum (rA2/rhIL-12/alum); two doses of non-replicative adenovirus recombinant vector encoding A2 (Ad5-A2) followed by two boosts with rA2/rhIL-12/alum (Ad5-A2+rA2/rhIL12/alum); and plasmid DNA encoding A2 gene (DNA-A2) boosted with two doses of Ad5-A2 (DNA-A2+Ad5-A2). Primates received a subsequent infectious challenge with L. infantum. Vaccines, apart from being safe, were immunogenic as animals responded with increased pre-challenge production of anti-A2-specific IgG antibodies, though with some variability in the response, depending on the vaccine formulation/protocol. The relative parasite load in the liver was significantly lower in immunized macaques as compared to controls. Protection correlated with hepatic granuloma resolution, and reduction of clinical symptoms, particularly when primates were vaccinated with the Ad5-A2+rA2/rhIL12/alum protocol. Conclusions/Significance The

  13. Synthesis of Polyfluoro Ketones for Selective Inhibition of Human Phospholipase A2 Enzymes

    PubMed Central

    Baskakis, Constantinos; Magrioti, Victoria; Cotton, Naomi; Stephens, Daren; Constantinou-Kokotou, Violetta; Dennis, Edward A.; Kokotos, George

    2009-01-01

    The development of selective inhibitors for individual PLA2 enzymes is necessary in order to target PLA2-specific signaling pathways; but it is challenging due to the observed promiscuity of known PLA2 inhibitors. In the current work, we present the development and application of a variety of synthetic routes to produce pentafluoro, tetrafluoro and trifluoro derivatives of activated carbonyl groups in order to screen for selective inhibitors and characterize the chemical properties that can lead to selective inhibition. Our results demonstrate that the pentafluoroethyl ketone functionality favors selective inhibition of the GVIA iPLA2, a very important enzyme for which specific, potent reversible inhibitors are needed. We find that 1,1,1,2,2-pentafluoro-7-phenyl-heptan-3-one (FKGK11) is a selective inhibitor of GVIA iPLA2 (XI(50) = 0.0073). Furthermore, we conclude that the introduction of an additional fluorine atom at the α′ position of a trifluoromethyl ketone constitutes an important strategy for the development of new potent GVIA iPLA2 inhibitors. PMID:19053783

  14. NcoA2-Dependent Inhibition of HIF-1α Activation Is Regulated via AhR.

    PubMed

    Tsai, Chi-Hao; Li, Ching-Hao; Liao, Po-Lin; Cheng, Yu-Wen; Lin, Cheng-Hui; Huang, Shih-Hsuan; Kang, Jaw-Jou

    2015-12-01

    High endogenous levels of aryl hydrocarbon receptor (AhR) contribute to hypoxia signaling pathway inhibition following exposure to the potent AhR ligand benzo[a]pyrene (B[a]P) and could alter cellular homeostasis and disease condition. Increasing evidence indicates that AhR might compete with AhR nuclear translocator (ARNT) for complex formation with hypoxia-inducible factor-1α (HIF-1α) for transactivation, which could alter several physiological variables. Nuclear receptor coactivator 2 (NcoA2) is a transcription coactivator that regulates transcription factor activation and inhibition of basic helix-loop-helix Per (Period)-ARNT-SIM (single-minded) (bHLH-PAS) family proteins, such as HIF-1α, ARNT, and AhR, through protein-protein interactions. In this study, we demonstrated that both hypoxia and hypoxia-mimic conditions decreased NcoA2 protein expression in HEK293T cells. Hypoxia response element (HRE) and xenobiotic-responsive element (XRE) transactivation also were downregulated with NcoA2 knockdown under hypoxic conditions. In addition, B[a]P significantly decreased NcoA2 protein expression be accompanied with AhR degradation. We next evaluated whether the absence of AhR could affect NcoA2 protein function under hypoxia-mimetic conditions. NcoA2 and HIF-1α nuclear localization decreased in both B[a]P-pretreated and AhR-knockdown HepG2 cells under hypoxia-mimic conditions. Interestingly, NcoA2 overexpression downregulated HRE transactivation by competing with HIF-1α and AhR to form protein complexes with ARNT. Both NcoA2 knockdown and overexpression inhibited endothelial cell tube formation in vitro. We also demonstrated using the in vivo plug assay that NcoA2-regulated vascularization decreased in mice. Taken together, these results revealed a biphasic role of NcoA2 between AhR and hypoxic conditions, thus providing a novel mechanism underlying the cross talk between AhR and hypoxia that affects disease development and progression.

  15. VEGF-B gene therapy inhibits doxorubicin-induced cardiotoxicity by endothelial protection

    PubMed Central

    Räsänen, Markus; Degerman, Joni; Nissinen, Tuuli A.; Miinalainen, Ilkka; Kerkelä, Risto; Siltanen, Antti; Backman, Janne T.; Mervaala, Eero; Hulmi, Juha J.; Kivelä, Riikka; Alitalo, Kari

    2016-01-01

    Congestive heart failure is one of the leading causes of disability in long-term survivors of cancer. The anthracycline antibiotic doxorubicin (DOX) is used to treat a variety of cancers, but its utility is limited by its cumulative cardiotoxicity. As advances in cancer treatment have decreased cancer mortality, DOX-induced cardiomyopathy has become an increasing problem. However, the current means to alleviate the cardiotoxicity of DOX are limited. We considered that vascular endothelial growth factor-B (VEGF-B), which promotes coronary arteriogenesis, physiological cardiac hypertrophy, and ischemia resistance, could be an interesting candidate for prevention of DOX-induced cardiotoxicity and congestive heart failure. To study this, we administered an adeno-associated viral vector expressing VEGF-B or control vector to normal and tumor-bearing mice 1 wk before DOX treatment, using doses mimicking the concentrations used in the clinics. VEGF-B treatment completely inhibited the DOX-induced cardiac atrophy and whole-body wasting. VEGF-B also prevented capillary rarefaction in the heart and improved endothelial function in DOX-treated mice. VEGF-B also protected cultured endothelial cells from apoptosis and restored their tube formation. VEGF-B increased left ventricular volume without compromising cardiac function, reduced the expression of genes associated with pathological remodeling, and improved cardiac mitochondrial respiration. Importantly, VEGF-B did not affect serum or tissue concentrations of DOX or augment tumor growth. By inhibiting DOX-induced endothelial damage, VEGF-B could provide a novel therapeutic possibility for the prevention of chemotherapy-associated cardiotoxicity in cancer patients. PMID:27799559

  16. Protective Role of Fucoidan in Cerebral Ischemia-Reperfusion Injury through Inhibition of MAPK Signaling Pathway.

    PubMed

    Che, Nan; Ma, Yijie; Xin, Yinhu

    2016-11-25

    Fucoidan has been reported to exhibit various beneficial activities ranging from to antivirus and anticancer properties. However, little information is available about the effects of fucoidan on cerebral ischemia-reperfusion injury (IRI). Our study aimed to explore the effects of fucoidan on cerebral IRI, as well as the underlying mechanisms. Sprague-Dawley (SD) rats were randomly subjected to four groups: Sham, IRI+saline (IRI+S), IRI+80 mg/kg fucoidan (IRI+F80), and IRI+160 mg/kg fucoidan (IRI+F160). Fucoidan (80 mg/kg or 160 mg/kg) was intraperitoneally injected from 7 days before the rats were induced to cerebral IRI model with middle cerebral artery occlusion (MCAO) method. At 24 h after reperfusion, neurological deficits and the total infarct volume were determined. The levels of inflammation-associated cytokines (interleukin (IL)-1β, IL-6, myeloperoxidase (MPO), and tumor necrosis factor (TNF)-α), oxidative stress-related proteins (malondialdehyde (MDA) and superoxide dismutase (SOD)) in the ischemic brain were measured by enzyme-linked immunosorbent assay (ELISA). Besides, the levels of apoptosis-related proteins (p-53, Bax, and B-cell lymphoma (Bcl)-2) and mitogen-activated protein kinase (MAPK) pathway (phosphorylation-extracellular signalregulated kinase (p-ERK), p-c-Jun N-terminal kinase (JNK), and p-p38) were measured. Results showed that administration of fucoidan significantly reduced the neurological deficits and infarct volume compared to the IRI+S group in a dose-dependent manner. Also, fucoidan statistically decreased the levels of inflammation-associated cytokines, and oxidative stress-related proteins, inhibited apoptosis, and suppressed the MAPK pathway. So, Fucoidan plays a protective role in cerebral IRI might be by inhibition of MAPK pathway.

  17. Flavonoids inhibit the platelet TxA2 signalling pathway and antagonize TxA2 receptors (TP) in platelets and smooth muscle cells

    PubMed Central

    Guerrero, José A; Navarro-Nuñez, Leyre; Lozano, María L; Martínez, Constantino; Vicente, Vicente; Gibbins, Jonathan M; Rivera, José

    2007-01-01

    What is already known about this subject Flavonoids are largely recognized as potential inhibitors of platelet function, through nonspecific mechanisms such as antioxidant activity and/or inhibition of several enzymes and signalling proteins. In addition, we, and few others, have shown that certain antiaggregant flavonoids may behave as specific TXA2 receptor (TP) ligands in platelets. Whether flavonoids interact with TP isoforms in other cell types is not known, and direct evidence that flavonoid–TP interaction inhibits signalling downstream TP has not been shown. What this study adds This study first demonstrates that certain flavonoids behave as ligands for both TP isoforms, not only in platelets, but also in human myometrium and in TP-transfected HEK 293T cells. Differences in the effect of certain flavonoids in platelet signalling, induced by either U46619 or thrombin, suggest that abrogation of downstream TP signalling is related to their specific blockage of the TP, rather than to a nonspecific effect on tyrosine kinases or other signalling proteins. Aims Flavonoids may affect platelet function by several mechanisms, including antagonism of TxA2 receptors (TP). These TP are present in many tissues and modulate different signalling cascades. We explored whether flavonoids affect platelet TP signalling, and if they bind to TP expressed in other cell types. Methods Platelets were treated with flavonoids, or other selected inhibitors, and then stimulated with U46619. Similar assays were performed in aspirinized platelets activated with thrombin. Effects on calcium release were analysed by fluorometry and changes in whole protein tyrosine phosphorylation and activation of ERK 1/2 by Western blot analysis. The binding of flavonoids to TP in platelets, human myometrium and TPα- and TPβ-transfected HEK 293T cells was explored using binding assays and the TP antagonist 3H-SQ29548. Results Apigenin, genistein, luteolin and quercetin impaired U46619-induced calcium

  18. Tetrahydrobiopterin Protects against Radiation-induced Growth Inhibition in H9c2 Cardiomyocytes

    PubMed Central

    Zhang, Zheng-Yi; Li, Yi; Li, Rui; Zhang, An-An; Shang, Bo; Yu, Jing; Xie, Xiao-Dong

    2016-01-01

    Background: Tetrahydrobiopterin (BH4) is an essential cofactor of nitric oxide synthases (NOSs) for the synthesis of nitric oxide (NO). BH4 therapy can reverse the disease-related redox disequilibrium observed with BH4 deficiency. However, whether BH4 exerts a protective effect against radiation-induced damage to cardiomyocytes remains unknown. Methods: Clonogenic assays were performed to determine the effects of X-ray on H9c2 cells with or without BH4 treatment. The contents of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA) in H9c2 cells were measured to investigate oxidative stress levels. The cell cycle undergoing radiation with or without BH4 treatment was detected using flow cytometry. The expression levels of proteins in the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/P53 signaling pathway, inducible NOS (iNOS), and endothelial NOS (eNOS) were examined using Western blotting. Results: X-ray radiation significantly inhibited the growth of H9c2 cells in a dose-dependent manner, whereas BH4 treatment significantly reduced the X-ray radiation-induced growth inhibition (control group vs. X-ray groups, respectively, P < 0.01). X-ray radiation induced LDH release, apoptosis, and G0/G1 peak accumulation, significantly increasing the level of MDA and the production of NO, and decreased the level of SOD (control group vs. X-ray groups, respectively, P < 0.05 or P < 0.01). By contrast, BH4 treatment can significantly reverse these processes (BH4 treatment groups vs. X-ray groups, P < 0.05 or P < 0.01). BH4 reversed the X-ray radiation-induced expression alterations of apoptosis-related molecules, including B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein, and caspase-3, and molecules of the PI3K/Akt/P53 signaling pathway. BH4 enhanced the production of NO in 2 Gy and 4 Gy radiated groups by upregulating eNOS protein expression and downregulating iNOS protein expression. Conclusions: BH4 treatment can protect

  19. Protection by Salidroside against Bone Loss via Inhibition of Oxidative Stress and Bone-Resorbing Mediators

    PubMed Central

    Yuan, Zhi; Fan, Jing; Li, Dan; Chen, Jian-Zong; Shi, Tian-Yao; Hu, Hui-Min; Wei, Bo-Yuan; Luo, Zhuo-Jing; Liu, Jian

    2013-01-01

    Oxidative stress is a pivotal pathogenic factor for bone loss in mouse model. Salidroside, a phenylpropanoid glycoside extracted from Rhodiola rosea L, exhibits potent antioxidative effects. In the present study, we used an in vitro oxidative stress model induced by hydrogen peroxide (H2O2) in MC3T3-E1 cells and a murine ovariectomized (OVX) osteoporosis model to investigate the protective effects of salidroside on bone loss and the related mechanisms. We demonstrated that salidroside caused a significant (P<0.05) elevation of cell survival, alkaline phosphatase (ALP) staining and activity, calcium deposition, and the transcriptional expression of Alp, Col1a1 and Osteocalcin (Ocn) in the presence of H2O2. Moreover, salidroside decreased the production of intracellular reactive oxygen species (ROS), and osteoclast differentiation inducing factors such as receptor activator of nuclear factor-kB ligand (RANKL) and IL-6 induced by H2O2. In vivo studies further demonstrated that salidroside supplementation for 3 months caused a decrease in malondialdehyde (MDA) and an increase in reduced glutathione (GSH) concentration in blood of ovariectomized mouse (P<0.05), it also improved trabecular bone microarchitecture and bone mineral density in the fourth lumbar vertebra and distal femur. Our study indicated that the protection provided by salidroside in alleviating bone loss was mediated, at least in part, via inhibition of the release of bone-resorbing mediators and oxidative damage to bone-forming cells, suggesting that salidroside can be used as an effective remedy in the treatment or prevention of osteoporosis. PMID:23437352

  20. Protection by salidroside against bone loss via inhibition of oxidative stress and bone-resorbing mediators.

    PubMed

    Zhang, Jin-Kang; Yang, Liu; Meng, Guo-Lin; Yuan, Zhi; Fan, Jing; Li, Dan; Chen, Jian-Zong; Shi, Tian-Yao; Hu, Hui-Min; Wei, Bo-Yuan; Luo, Zhuo-Jing; Liu, Jian

    2013-01-01

    Oxidative stress is a pivotal pathogenic factor for bone loss in mouse model. Salidroside, a phenylpropanoid glycoside extracted from Rhodiola rosea L, exhibits potent antioxidative effects. In the present study, we used an in vitro oxidative stress model induced by hydrogen peroxide (H(2)O(2)) in MC3T3-E1 cells and a murine ovariectomized (OVX) osteoporosis model to investigate the protective effects of salidroside on bone loss and the related mechanisms. We demonstrated that salidroside caused a significant (P<0.05) elevation of cell survival, alkaline phosphatase (ALP) staining and activity, calcium deposition, and the transcriptional expression of Alp, Col1a1 and Osteocalcin (Ocn) in the presence of H(2)O(2). Moreover, salidroside decreased the production of intracellular reactive oxygen species (ROS), and osteoclast differentiation inducing factors such as receptor activator of nuclear factor-kB ligand (RANKL) and IL-6 induced by H(2)O(2). In vivo studies further demonstrated that salidroside supplementation for 3 months caused a decrease in malondialdehyde (MDA) and an increase in reduced glutathione (GSH) concentration in blood of ovariectomized mouse (P<0.05), it also improved trabecular bone microarchitecture and bone mineral density in the fourth lumbar vertebra and distal femur. Our study indicated that the protection provided by salidroside in alleviating bone loss was mediated, at least in part, via inhibition of the release of bone-resorbing mediators and oxidative damage to bone-forming cells, suggesting that salidroside can be used as an effective remedy in the treatment or prevention of osteoporosis.

  1. NPR3 protects cardiomyocytes from apoptosis through inhibition of cytosolic BRCA1 and TNF-α

    PubMed Central

    Lin, Dong; Chai, Yubo; Izadpanah, Reza; Braun, Stephen E.; Alt, Eckhard

    2016-01-01

    ABSTRACT Natriuretic peptide receptor 3 (NPR3) is a clearance receptor by binding and internalizing natriuretic peptides (NPs) for ultimate degradation. Patients with cardiac failure show elevated NPs. NPs are linked to poor long-term survival because of their apoptotic effects. However, the underling mechanisms have not been identified yet. Here we report the role of NPR3 in anti-apoptosis via the breast cancer type 1 susceptibility protein (BRCA1) and tumor necrosis factor α (TNF-α ). To demonstrate a role for NPR3 in apoptosis, stable H9C2 cardiomyocyte cell lines using shRNA to knockdown NPR3 were generated. The activities of caspase-3, 8, and 9 were significantly increased in NPR3 knockdown H9C2 cardiomyocytes. Knockdown of NPR3 increased the expression of BRCA1. Also NPR3 knockdown remarkably increased the activity of cAMP response element-binding protein (CREB), a positive regulatory element for BRCA1 expression. BRCA1 showed dispersed nuclear localization in non-cardiomyocytes while predominantly cytoplasmic localization in H9C2 cells. Meanwhile, NPR3 knockdown significantly increased TNF-α gene expression. These data show that NPR3 knockdown in H9C2 cells triggered both extrinsic and intrinsic apoptotic pathways. NPR3 protects cardiomyocytes from apoptosis through inhibition of cytosolic BRCA1 and TNF-α, which are regulators of apoptosis. Our studies demonstrate anti-apoptosis role of NPR3 in protecting cardiomyocytes and establish the first molecular link between NP system and programmed cell death. PMID:27494651

  2. Nuclear protein 1 promotes pancreatic cancer development and protects cells from stress by inhibiting apoptosis

    PubMed Central

    Hamidi, Tewfik; Algül, Hana; Cano, Carla Eliana; Sandi, Maria José; Molejon, Maria Inés; Riemann, Marc; Calvo, Ezequiel Luis; Lomberk, Gwen; Dagorn, Jean-Charles; Weih, Falk; Urrutia, Raul; Schmid, Roland Michael; Iovanna, Juan Lucio

    2012-01-01

    Pancreatic ductal adenocarcinoma (PDAC) has the lowest survival rate of all cancers and shows remarkable resistance to cell stress. Nuclear protein 1 (Nupr1), which mediates stress response in the pancreas, is frequently upregulated in pancreatic cancer. Here, we report that Nupr1 plays an essential role in pancreatic tumorigenesis. In a mouse model of pancreatic cancer with constitutively expressed oncogenic KrasG12D, we found that loss of Nupr1 protected from the development of pancreatic intraepithelial neoplasias (PanINs). Further, in cultured pancreatic cells, nutrient deprivation activated Nupr1 expression, which we found to be required for cell survival. We found that Nupr1 protected cells from stress-induced death by inhibiting apoptosis through a pathway dependent on transcription factor RelB and immediate early response 3 (IER3). NUPR1, RELB, and IER3 proteins were coexpressed in mouse PanINs from KrasG12D-expressing pancreas. Moreover, pancreas-specific deletion of Relb in a KrasG12D background resulted in delayed in PanIN development associated with a lack of IER3 expression. Thus, efficient PanIN formation was dependent on the expression of Nupr1 and Relb, with likely involvement of IER3. Finally, in patients with PDAC, expression of NUPR1, RELB, and IER3 was significantly correlated with a poor prognosis. Cumulatively, these results reveal a NUPR1/RELB/IER3 stress-related pathway that is required for oncogenic KrasG12D-dependent transformation of the pancreas. PMID:22565310

  3. INHIBITION OF SOLUBLE EPOXIDE HYDROLASE DOES NOT PROTECT AGAINST ENDOTOXIN-MEDIATED HEPATIC INFLAMMATION

    PubMed Central

    Fife, Kimberly L.; Liu, YingMei; Schmelzer, Kara R.; Tsai, Hsing-Ju; Kim, In-Hae; Morisseau, Christophe; Hammock, Bruce D.; Kroetz, Deanna L.

    2009-01-01

    Epoxyeicosatrienoic acids (EETs) are derived from cytochrome P450 (CYP)-catalyzed epoxygenation of arachidonic acid and have emerged as important mediators of numerous biological effects. The major elimination pathway for EETs is through soluble epoxide hydrolase (sEH) catalyzed metabolism to dihydroxyeicosatrienoic acids (DHETs). Based on previous studies showing that EETs have anti-inflammatory effects, we hypothesized that chronic inhibition of sEH would attenuate a lipopolysaccharide (LPS)-induced inflammatory response in vivo. Continuous dosing of the sEH inhibitors 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), a polyethylene glycol ester of AUDA (AUDA-PEG), and 1-adamantan-1-yl-3-(5-(2-(2-ethoxyethoxy)ethoxy)pentyl)urea (AEPU) resulted in robust exposure to the inhibitor and target engagement, as evidenced by significant increases in plasma EET/DHET ratios following six days of inhibitor treatment. However, sEH inhibitor treatment was not associated with an attenuation of LPS-induced inflammatory gene expression in the liver and AUDA did not protect from LPS-induced neutrophil infiltration. Furthermore, Ephx2 −/− mice that lack sEH expression and have significantly increased plasma EET/DHET ratios were not protected from LPS-induced inflammatory gene expression or neutrophil accumulation in the liver. LPS did have an effect on sEH expression and function, as evident from a significant downregulation of Ephx2 mRNA and a significant shift in plasma EET/DHET ratios four hours after LPS treatment. In conclusion, there was no evidence that increasing EET levels in vivo could modulate an LPS-induced inflammatory response in the liver. However, LPS did have significant effects on plasma eicosanoid levels and hepatic Ephx2 expression, suggesting that in vivo EET levels are modulated in response to an inflammatory signal. PMID:18815352

  4. Melanin Protects Paracoccidioides brasiliensis from the Effects of Antimicrobial Photodynamic Inhibition and Antifungal Drugs

    PubMed Central

    Baltazar, Ludmila Matos; Werneck, Silvia Maria Cordeiro; Soares, Betânia Maria; Ferreira, Marcus Vinicius L.; Souza, Danielle G.; Pinotti, Marcos; Santos, Daniel Assis

    2015-01-01

    Paracoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced by Paracoccidioides spp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated. aPI was performed using toluidine blue (TBO) as a photosensitizer and a 630-nm light-emitting diode (LED) light. The antifungals tested were itraconazole and amphotericin B. We evaluated the effects of each approach, aPI or antifungals, against nonmelanized and melanized yeast cells by performing susceptibility tests and by quantifying oxidative and nitrosative bursts during the experiments. aPI reduced nonmelanized cells by 3.0 log units and melanized cells by 1.3 log units. The results showed that melanization protects the fungal cell, probably by acting as a scavenger of nitric oxide and reactive oxygen species, but not of peroxynitrite. Melanin also increased the MICs of itraconazole and amphotericin B, and the drugs were fungicidal for nonmelanized and fungistatic for melanized yeast cells. Our study shows that melanin production by Paracoccidioides yeast cells serves a protective function during aPI and treatment with itraconazole and amphotericin B. The results suggest that melanin binds to the drugs, changing their antifungal activities, and also acts as a scavenger of reactive oxygen species and nitric oxide, but not of peroxynitrite, indicating that peroxynitrite is the main radical that is responsible for fungal death after aPI. PMID:25896704

  5. Oral pirfenidone protects against fibrosis by inhibiting fibroblast proliferation and TGF-β signaling in a murine colitis model.

    PubMed

    Li, Guanwei; Ren, Jianan; Hu, Qiongyuan; Deng, Youming; Chen, Guopu; Guo, Kun; Li, Ranran; Li, Yuan; Wu, Lei; Wang, Gefei; Gu, Guosheng; Li, Jieshou

    2016-10-01

    Inflammatory bowel disease (IBD), particularly Crohn's disease, frequently causes intestinal fibrosis that ultimately leads to formation of strictures requiring bowel resection. Currently there is no effective antifibrotic therapy available for this disease. Pirfenidone is a small compound that has a broad spectrum of antifibrogenic effect and has been used for the treatment of fibrotic diseases in various organs. The present study aimed to investigate the antifibrogenic effect of pirfenidone in a dextran sulfate sodium (DSS)-induced murine colitis model. C57BL/6 mice were used and animals were randomly divided into groups receiving pirfenidone or vehicle by oral or transanal routes. Inflammation- and fibrosis-related indexes including body weight, colon length, disease activity, histological change, mRNA expression of pro-inflammatory and pro-fibrogenic cytokines were assessed. Furthermore, we performed in vitro analysis using CCD18-Co fibroblasts to evaluate cell proliferation, transdifferentiation, and viability after the cells were cultured with pirfenidone. It was found that oral administration of pirfenidone reduced deposition of collagen in colitis-associated fibrosis, and significantly suppressed the mRNA expression of col1a2, col3a1, and TGF-β. Moreover, pirfenidone inhibited the activation of TGF-β-related smad and MAPK pathways both in vitro and in vivo. Clinical and histological evaluation demonstrated that pirfenidone had no anti-inflammatory effect. The antifibrogenic effect was reduced when pirfenidone was administered in a delayed manner and was unobserved if given locally. Pirfenidone suppressed fibroblast proliferation and transdifferentiation without observed toxicity. Altogether, our results suggested that oral pirfenidone protects against fibrosis of DSS-induced colitis through inhibiting the proliferation of colonic fibroblasts and TGF-β signaling pathways.

  6. Nuclear Receptor Nr4a2 Promotes Alternative Polarization of Macrophages and Confers Protection in Sepsis.

    PubMed

    Mahajan, Sahil; Saini, Ankita; Chandra, Vemika; Nanduri, Ravikanth; Kalra, Rashi; Bhagyaraj, Ella; Khatri, Neeraj; Gupta, Pawan

    2015-07-24

    The orphan nuclear receptor Nr4a2 is known to modulate both inflammatory and metabolic processes, but the mechanism by which it regulates innate inflammatory homeostasis has not been adequately addressed. This study shows that exposure to ligands for Toll-like receptors (TLRs) robustly induces Nr4a2 and that this induction is tightly regulated by the PI3K-Akt signaling axis. Interestingly, exogenous expression of Nr4a2 in macrophages leads to their alternative phenotype with induction of genes that are prototypical M2 markers. Moreover, Nr4a2 transcriptionally activates arginase 1 expression by directly binding to its promoter. Adoptive transfer experiments revealed that increased survival of animals in endotoxin-induced sepsis is Nr4a2-dependent. Thus our data identify a previously unknown role for Nr4a2 in the regulation of macrophage polarization. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Reduced prepulse inhibition in adolescents at risk for psychosis: a 2-year follow-up study

    PubMed Central

    Ziermans, Tim; Schothorst, Patricia; Magnée, Maurice; van Engeland, Herman; Kemner, Chantal

    2011-01-01

    Background Reduced prepulse inhibition (PPI) of the auditory startle reflex is a hallmark feature of attention-processing deficits in patients with schizophrenia and other psychotic disorders. Recent evidence suggests that these deficits may also be present before the onset of psychosis in individuals at ultra-high risk (UHR) and become progressively worse as psychosis develops. We conducted a longitudinal follow-up study to observe the development of PPI over time in UHR adolescents and healthy controls. Methods Two-year follow-up data of PPI measures were compared between UHR adolescents and a matched control group of typically developing individuals. Results We included 42 UHR adolescents and 32 matched controls in our study. Compared with controls, UHR individuals showed reduced PPI at both assessments. Clinical improvement in UHR individuals was associated with an increase in PPI parameters. Limitations A developmental increase in startle magnitude partially confined the interpretation of the association between clinical status and PPI. Furthermore, post hoc analyses for UHR individuals who became psychotic between assessments had limited power owing to a low transition rate (14%). Conclusion Deficits in PPI are present before the onset of psychosis and represent a stable vulnerability marker over time in UHR individuals. The magnitude of this marker may partially depend on the severity of clinical symptoms. PMID:21266126

  8. Protective immunity against challenge with Leishmania (Leishmania) chagasi in beagle dogs vaccinated with recombinant A2 protein.

    PubMed

    Fernandes, Ana Paula; Costa, Míriam Maria Silva; Coelho, Eduardo Antônio Ferraz; Michalick, Marilene Suzan Marques; de Freitas, Eloísa; Melo, Maria Norma; Luiz Tafuri, Wagner; Resende, Daniela de Melo; Hermont, Vinícius; Abrantes, Christiane de Freitas; Gazzinelli, Ricardo Tostes

    2008-10-29

    In this study, we investigated in dogs the immunogenicity and protective immunity against Leishmania (Leishmania) chagasi infection induced by vaccination with a formulation containing the recombinant A2 protein, an amastigote specific antigen, and saponin. Vaccinated animals produced significantly increased levels of total IgG and IgG2, but not IgG1 anti-A2 antibodies, and remained negative in conventional leishmaniasis serodiagnostic methods. Significantly increased IFN-gamma and low IL-10 levels were detected in vaccinated animals before and after challenge, as compared to control animals. Importantly, while the symptoms onset appeared as early as three months after infection in most control dogs, 14 months after challenge, 5 out of 7 vaccinated dogs remained asymptomatic. Therefore, immunization with rA2 antigen was immunogenic and induced partial protection in dogs, and allowed the serological differentiation between vaccinated and infected animals, an important requirement for a canine visceral leishmaniasis (CVL) vaccine.

  9. Protective immunity provided by HLA-A2 epitopes for fusion and hemagglutinin proteins of measles virus

    SciTech Connect

    Oh, Sang Kon . E-mail: sangkono@baylorhealth.edu; Stegman, Brian; Pendleton, C. David; Ota, Martin O.; Pan, C.-H.; Griffin, Diane E.; Burke, Donald S.; Berzofsky, Jay A. . E-mail: berzofsk@helix.nih.gov

    2006-09-01

    Natural infection and vaccination with a live-attenuated measles virus (MV) induce CD8{sup +} T-cell-mediated immune responses that may play a central role in controlling MV infection. In this study, we show that newly identified human HLA-A2 epitopes from MV hemagglutinin (H) and fusion (F) proteins induced protective immunity in HLA-A2 transgenic mice challenged with recombinant vaccinia viruses expressing F or H protein. HLA-A2 epitopes were predicted and synthesized. Five and four peptides from H and F, respectively, bound to HLA-A2 molecules in a T2-binding assay, and four from H and two from F could induce peptide-specific CD8{sup +} T cell responses in HLA-A2 transgenic mice. Further experiments proved that three peptides from H (H9-567, H10-250, and H10-516) and one from F protein (F9-57) were endogenously processed and presented on HLA-A2 molecules. All peptides tested in this study are common to 5 different strains of MV including Edmonston. In both A2K{sup b} and HHD-2 mice, the identified peptide epitopes induced protective immunity against recombinant vaccinia viruses expressing H or F. Because F and H proteins induce neutralizing antibodies, they are major components of new vaccine strategies, and therefore data from this study will contribute to the development of new vaccines against MV infection.

  10. Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates

    SciTech Connect

    Schallreuter, Karin U.; University of Bradford ). E-mail: K.Schallreuter@bradford.ac.uk; Gibbons, Nicholas C.J.; Elwary, Souna M.; Parkin, Susan M.; Wood, John M.

    2007-04-20

    The human epidermis holds an autocrine acetylcholine production and degradation including functioning membrane integrated and cytosolic butyrylcholinesterase (BuchE). Here we show that BuchE activities increase 9-fold in the presence of calcium (0.5 x 10{sup -3}M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. {sup 45}Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H{sub 2}O{sub 2}-mediated oxidation. Moreover, we confirmed the faster hydrolysis by calcium-activated BuchE using the neurotoxic organophosphate O-ethyl-O-(4-nitrophenyl)-phenylphosphonothioate (EPN). Considering the large size of the human skin with 1.8 m{sup 2} surface area with its calcium gradient in the 10{sup -3}M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue.

  11. Betulinic acid protects against ischemia/reperfusion-induced renal damage and inhibits leukocyte apoptosis.

    PubMed

    Ekşioğlu-Demiralp, Emel; Kardaş, E Riza; Ozgül, Seçkin; Yağci, Tayfur; Bilgin, Hüseyin; Sehirli, Ozer; Ercan, Feriha; Sener, Göksel

    2010-03-01

    The possible protective effect of betulinic acid on renal ischemia/reperfusion (I/R) injury was studied. Wistar Albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. Betulinic acid (250 mg/kg, i.p.) or saline was administered at 30 min prior to ischemia and immediately before the reperfusion. Creatinine, blood urea nitrogen (BUN), lactate dehydrogenase (LDH) and TNF-alpha as well as the oxidative burst of neutrophil and leukocyte apoptosis were assayed in blood samples. Malondialdehyde (MDA), glutathione (GSH) levels, Na(+), K(+)-ATPase and myeloperoxidase (MPO) activities were determined in kidney tissue which was also analysed microscopically. I/R caused significant increases in blood creatinine, BUN, LDH and TNF-alpha. In the kidney samples of the I/R group, MDA levels and MPO activity were increased significantly, however, GSH levels and Na(+), K(+)-ATPase activity were decreased. Betulinic acid ameliorated the oxidative burst response to both formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol 12-myristate 13-acetate (PMA) stimuli, normalized the apoptotic response and most of the biochemical indices as well as histopathological alterations induced by I/R. In conclusion, these data suggest that betulinic acid attenuates I/R-induced oxidant responses, improved microscopic damage and renal function by regulating the apoptotic function of leukocytes and inhibiting neutrophil infiltration.

  12. Protective effects of genetic inhibition of Discoidin Domain Receptor 1 in experimental renal disease.

    PubMed

    Kerroch, Monique; Alfieri, Carlo; Dorison, Aude; Boffa, Jean-Jacques; Chatziantoniou, Christos; Dussaule, Jean-Claude

    2016-02-16

    Chronic kidney disease is a progressive incurable pathology affecting millions of people. Intensive investigations aim to identify targets for therapy. We have previously demonstrated that abnormal expression of the Discoidin Domain Receptor 1 (DDR1) is a key factor of renal disease by promoting inflammation and fibrosis. The present study investigates whether blocking the expression of DDR1 after the initiation of renal disease can delay or arrest the progression of this pathology. Severe renal disease was induced by either injecting nephrotoxic serum (NTS) or performing unilateral ureteral obstruction in mice, and the expression of DDR1 was inhibited by administering antisense oligodeoxynucleotides either at 4 or 8 days after NTS (corresponding to early or more established phases of disease, respectively), or at day 2 after ligation. DDR1 antisense administration at day 4 stopped the increase of proteinuria and protected animals against the progression of glomeruloneprhitis, as evidenced by functional, structural and cellular indexes. Antisense administration at day 8 delayed progression -but to a smaller degree- of renal disease. Similar beneficial effects on renal structure and inflammation were observed with the antisense administration of DDR1 after ureteral ligation. Thus, targeting DDR1 can be a promising strategy in the treatment of chronic kidney disease.

  13. Zinc finger antiviral protein inhibits coxsackievirus B3 virus replication and protects against viral myocarditis.

    PubMed

    Li, Min; Yan, Kepeng; Wei, Lin; Yang, Jie; Lu, Chenyu; Xiong, Fei; Zheng, Chunfu; Xu, Wei

    2015-11-01

    The host Zinc finger antiviral protein (ZAP) has been reported exhibiting antiviral activity against positive-stranded RNA viruses (Togaviridae), negative-stranded RNA viruses (Filoviridae) and retroviruses (Retroviridae). However, whether ZAP restricts the infection of enterovirus and the development of enterovirus mediated disease remains unknown. Here, we reported the antiviral properties of ZAP against coxsackievirus B3 (CVB3), a single-stranded RNA virus of the Enterovirus genus within the Picornaviridae as a major causative agent of viral myocarditis (VMC). We found that the expression of ZAP was significantly induced after CVB3 infection in heart tissues of VMC mice. ZAP potently inhibited CVB3 replication in cells after infection, while overexpression of ZAP in mice significantly increased the resistance to CVB3 replication and viral myocarditis by significantly reducing cardiac inflammatory cytokine production. The ZAP-responsive elements (ZREs) were mapped to the 3'UTR and 5'UTR of viral RNA. Taken together, ZAP confers resistance to CVB3 infection via directly targeting viral RNA and protects mice from acute myocarditis by suppressing viral replication and cardiac inflammatory cytokine production. Our finding further expands ZAP's range of viral targets, and suggests ZAP as a potential therapeutic target for viral myocarditis caused by CVB3.

  14. Ephedrine hydrochloride protects mice from LPS challenge by promoting IL-10 secretion and inhibiting proinflammatory cytokines.

    PubMed

    Zheng, Yuejuan; Guo, Ziyi; He, Weigang; Yang, Yang; Li, Yuhu; Zheng, Aoxiang; Li, Ping; Zhang, Yan; Ma, Jinzhu; Wen, Mingyue; Yang, Muyi; An, Huazhang; Ji, Guang; Yu, Yizhi

    2012-05-01

    Sepsis and its derivative endotoxic shock are still serious conditions with high mortality in the intensive care unit. The mechanisms that ensure the balance of proinflammatory cytokines and anti-inflammatory cytokine production are of particular importance. As an active α- and β-adrenergic agonist, ephedrine hydrochloride (EH) is a widely used agent for cardiovascular diseases, especially boosting blood pressure. Here we demonstrate that EH increased Toll-like receptor 4 (TLR4)-mediated production of interleukin 10 (IL-10) through p38 MAPK activation. Simultaneously, EH negatively regulated the production of proinflammatory cytokines. Consistently, EH increased lipopolysaccharide (LPS)-induced serum IL-10 and inhibited tumor necrotic factor-α (TNFα) production in vivo. As a result, EH treatment protected mice from endotoxic shock by lethal LPS challenge. In brief, our data demonstrated that EH could contribute to immune homeostasis by balancing the production of proinflammatory cytokines and anti-inflammatory cytokine in TLR4 signaling. This study provides a potential usage of EH in autoimmunologic diseases or other severe inflammations.

  15. Hepato-protective effects of six schisandra lignans on acetaminophen-induced liver injury are partially associated with the inhibition of CYP-mediated bioactivation.

    PubMed

    Jiang, Yiming; Fan, Xiaomei; Wang, Ying; Tan, Huasen; Chen, Pan; Zeng, Hang; Huang, Min; Bi, Huichang

    2015-04-25

    Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. Schisandra fructus is widely-used traditional Chinese medicine which possesses hepato-protective potential. Schisandrin A (SinA), Schisandrin B (SinB), Schisandrin C (SinC), Schisandrol A (SolA), Schisandrol B (SolB), and Schisantherin A (SthA) are the major bioactive lignans. Most recently, we found SolB exerts significant hepato-protection against APAP-induced liver injury. In this study, the protective effects of the other five schisandra lignans against APAP-induced acute hepatotoxicity in mice were investigated and compared with that of SolB. The results of morphological and biochemical assessment clearly demonstrated significant protective effects of SinA, SinB, SinC, SolA, SolB, and SthA against APAP-induced liver injury. Among these schisandra lignans, SinC and SolB exerted the strongest hepato-protective effects against APAP-induced hepatotoxicity. Six lignans pretreatment before APAP dosing could prevent the depletions of total liver glutathione (GSH) and mitochondrial GSH caused by APAP. Additionally, the lignans treatment inhibited the enzymatic activities of three CYP450 isoforms (CYP2E1, CYP1A2, and CYP3A11) related to APAP bioactivation, and further decreased the formation of APAP toxic intermediate N-acetyl-p-benzoquinone imine (NAPQI) in mouse microsomal incubation system. This study demonstrated that SinA, SinB, SinC, SolA, SolB and SthA exhibited significant protective actions toward APAP-induced liver injury, which was partially associated with the inhibition of CYP-mediated APAP bioactivation.

  16. The A2B adenosine receptor protects against inflammation and excessive vascular adhesion

    PubMed Central

    Yang, Dan; Zhang, Ying; Nguyen, Hao G.; Koupenova, Milka; Chauhan, Anil K.; Makitalo, Maria; Jones, Matthew R.; Hilaire, Cynthia St.; Seldin, David C.; Toselli, Paul; Lamperti, Edward; Schreiber, Barbara M.; Gavras, Haralambos; Wagner, Denisa D.; Ravid, Katya

    2006-01-01

    Adenosine has been described as playing a role in the control of inflammation, but it has not been certain which of its receptors mediate this effect. Here, we generated an A2B adenosine receptor–knockout/reporter gene–knock-in (A2BAR-knockout/reporter gene–knock-in) mouse model and showed receptor gene expression in the vasculature and macrophages, the ablation of which causes low-grade inflammation compared with age-, sex-, and strain-matched control mice. Augmentation of proinflammatory cytokines, such as TNF-α, and a consequent downregulation of IκB-α are the underlying mechanisms for an observed upregulation of adhesion molecules in the vasculature of these A2BAR-null mice. Intriguingly, leukocyte adhesion to the vasculature is significantly increased in the A2BAR-knockout mice. Exposure to an endotoxin results in augmented proinflammatory cytokine levels in A2BAR-null mice compared with control mice. Bone marrow transplantations indicated that bone marrow (and to a lesser extent vascular) A2BARs regulate these processes. Hence, we identify the A2BAR as a new critical regulator of inflammation and vascular adhesion primarily via signals from hematopoietic cells to the vasculature, focusing attention on the receptor as a therapeutic target. PMID:16823489

  17. [Respiration of wheat roots during inhibition of phospholipase A2 by 4-bromphenacylbromide].

    PubMed

    Valitova, Iu N; Gordon, L Kh; Ogorodnikova, T I; Lygin, A V; Ruban, N F

    2001-01-01

    Dependence of oxygen consumption by wheat root cells on the activity of phospholipase A2 (PLA2) was studied. The treatment of excised roots with 4-bromophenacile bromide (BPB), a specific inhibitor of PLA2, caused a decrease in the content of free fatty acids (FFA) and in oxygen consumption of root cells. The latter was prevented by exogenous application of a mixture of FFA. A similar inhibitory effect was caused by BPB after the activation of root respiration by 2,4-dinitrophenol (DNP). These data suggest that FFA may be involved in the regulation of respiration through the formation of succinate. This is supported by the fact of reduction of DNP-induced stimulation of oxygen consumption by malonate, known to be an inhibitor of succinate dehydrogenase, and by stimulation of respiration by exogenous application of succinate.

  18. The Protective Effects of Religiosity on Depression: A 2-Year Prospective Study.

    PubMed

    Ronneberg, Corina R; Miller, Edward Alan; Dugan, Elizabeth; Porell, Frank

    2016-06-01

    Approximately 20% of older adults are diagnosed with depression in the United States. Extant research suggests that engagement in religious activity, or religiosity, may serve as a protective factor against depression. This prospective study examines whether religiosity protects against depression and/or aids in recovery. Study data are drawn from the 2006 and 2008 waves of the Health and Retirement Study. The sample consists of 1,992 depressed and 5,740 nondepressed older adults (mean age = 68.12 years), at baseline (2006), for an overall sample size of 7,732. Logistic regressions analyzed the relationship between organizational (service attendance), nonorganizational (private prayer), and intrinsic measures of religiosity and depression onset (in the baseline nondepressed group) and depression recovery (in the baseline depressed group) at follow-up (2008), controlling for other baseline factors. Religiosity was found to both protect against and help individuals recover from depression. Individuals not depressed at baseline remained nondepressed 2 years later if they frequently attended religious services, whereas those depressed at baseline were less likely to be depressed at follow-up if they more frequently engaged in private prayer. Findings suggest that both organizational and nonorganizational forms of religiosity affect depression outcomes in different circumstances (i.e., onset and recovery, respectively). Important strategies to prevent and relieve depression among older adults may include improving access and transportation to places of worship among those interested in attending services and facilitating discussions about religious activities and beliefs with clinicians. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Suramin inhibits macrophage activation by human group IIA phospholipase A2, but does not affect bactericidal activity of the enzyme.

    PubMed

    Aragão, E A; Chioato, L; Ferreira, T L; de Medeiros, A I; Secatto, A; Faccioli, L H; Ward, R J

    2009-04-01

    Suramin is a polysulphonated napthylurea antiprotozoal and anthelminitic drug, which also presents inhibitory activity against a broad range of enzymes. Here we evaluate the effect of suramin on the hydrolytic and biological activities of secreted human group IIA phospholipase A(2) (hsPLA(2)GIIA). The hsPLA(2)GIIA was expressed in E. coli, and refolded from inclusion bodies. The hydrolytic activity of the recombinant enzyme was measured using mixed dioleoylphosphatidylcholine/dioleoylphosphatidylglycerol (DOPC/DOPG) liposomes. The activation of macrophage cell line RAW 264.7 by hsPLA(2) GIIA was monitored by NO release, and bactericidal activity against Micrococcus luteus was evaluated by colony counting and by flow cytometry using the fluorescent probe Sytox Green. The hydrolytic activity of the hsPLA(2) GIIA was inhibited by a concentration of 100 nM suramin and the activation of macrophages by hsPLA(2) GIIA was abolished at protein/suramin molar ratios where the hydrolytic activity of the enzyme was inhibited. In contrast, both the bactericidal activity of hsPLA(2) GIIA against Micrococcus luteus and permeabilization of the bacterial inner membrane were unaffected by suramin concentrations up to 50 microM. These results demonstrate that suramin selectively inhibits the activity of the hsPLA(2) GIIA against macrophages, whilst leaving the anti-bacterial function unchanged.

  20. Magnesium isoglycyrrhizinate inhibits inflammatory response through STAT3 pathway to protect remnant liver function.

    PubMed

    Tang, Guang-Hua; Yang, Hua-Yu; Zhang, Jin-Chun; Ren, Jin-Jun; Sang, Xin-Ting; Lu, Xin; Zhong, Shou-Xian; Mao, Yi-Lei

    2015-11-21

    To investigate the protective effect of magnesium isoglycyrrhizinate (MgIG) on excessive hepatectomy animal model and its possible mechanism. We used the standard 90% hepatectomy model in Sprague-Dawley rats developed using the modified Emond's method, in which the left, middle, right upper, and right lower lobes of the liver were removed. Rats with 90% liver resection were divided into three groups, and were injected intraperitoneally with 3 mL saline (control group), 30 mg/kg (low-dose group) and 60 mg/kg (high-dose group) of MgIG, respectively. Animals were sacrificed at various time points and blood was drawn from the vena cava. Biochemical tests were performed with an automatic biochemical analyzer for the following items: serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyl endopeptidase, total bilirubin (TBil), direct bilirubin (DBil), total protein, albumin, blood glucose (Glu), hyper-sensitivity C-reactive protein, prothrombin time (PT), and thrombin time (TT). Postoperative survival time was observed hourly until death. Hepatocyte regeneration was analyzed by immunohistochemistry. Serum inflammatory cytokines (IL-1, IL-6, IL-10, and iNOS) was analyzed by ELISA. STAT3 protein and mRNA were analyzed by Western blot and quantitative reverse-transcription PCR, respectively. The high-dose group demonstrated a significantly prolonged survival time, compared with both the control and the low-dose groups (22.0 ± 4.7 h vs 8.9 ± 2.0 vs 10.3 ± 3.3 h, P = 0.018). There were significant differences among the groups in ALT, Glu and PT levels starting from 6 h after surgery. The ALT levels were significantly lower in the MgIG treated groups than in the control group. Both Glu and PT levels were significantly higher in the MgIG treated groups than in the control group. At 12 h, ALT, AST, TBil, DBil and TT levels showed significant differences between the MgIG treated groups and the control group. No significant differences in hepatocyte

  1. CBLB502 administration protects gut mucosal tissue in ulcerative colitis by inhibiting inflammation

    PubMed Central

    Xu, Yang; Dong, Hongxia; Ge, Changhui; Gao, Yan; Liu, Haifeng

    2016-01-01

    Background Ulcerative colitis (UC) is a nonspecific inflammatory disease for which medications and therapeutic strategies have only been moderately successful. CBLB502, a toll-like receptor 5 (TLR5) agonist derived from Salmonella flagellin, exhibits anticancer and radioprotective activities via modulation of TLRs and the nuclear factor kappa B (NF-κB) signaling pathway and can protect against acute renal ischemic failure. In this study, we intend to examine the effects of CBLB502 on both TLR responses and the interleukin (IL) and NF-κB signaling pathways in UC treatment. Methods The UC mouse model was prepared in BALB/c mice by administering 2,4,6-trinitrobenzene sulfonic acid (TNBS). CBLB502 was used as the therapeutic drug. After CBLB502 therapy, the IL and tumor necrosis factor-α (TNF-α) levels were measured by ELISA. Total RNA and protein of colon samples was extracted. Results We found that CBLB502 had a distinctive therapeutic effect in the UC model. In control group animals, IL-10 expression in serum was 91.48±24.38 ng/mL; this was higher than in the model group (59.36±14.46 ng/mL, P<0.05) or the treatment group (54.29±5.83 ng/mL, P<0.05). In model group animals, the concentration of TNF-α in serum was 140.11±12.70 ng/mL, which was lower than protein levels in the control group (173.86±29.26 ng/mL, P<0.05). The mRNA levels of TLR1, 2, 3, 4, 6, 7, 8, and 9 in the CBLB502 treatment group were significantly lower than in the model group (P<0.05). Western blot revealed that CBLB502 also reduced NF-κB expression in the mouse colon, but that NF-κB expression was not significantly lower than the model group. Conclusions CBLB502 can reduce mucosal damage induced by TNBS and inhibit inflammation and TLR expression. The inhibition of UC by CBLB502 is strictly TLR-IL-dependent and is dose-dependent within the efficacious dose range. Therefore, our results suggested that CBLB502 might be a candidate drug for the treatment of UC. PMID:27668221

  2. Inhibition of the NMDA receptor protects the rat sciatic nerve against ischemia/reperfusion injury

    PubMed Central

    KE, TIE; LI, RENBIN; CHEN, WENCHANG

    2016-01-01

    Inhibition of the N-methyl-D-aspartate (NMDA) receptor by MK-801 reduces ischemia/reperfusion (I/R) injury in the central nervous system. However, few previous studies have evaluated the neuroprotective effects of MK-801 against peripheral I/R injury. The present study aimed to investigate the protective effects of MK-801 pretreatment against I/R injury in the rat sciatic nerve (SN). Sprague-Dawley rats were subjected to a sham surgery (n=8) or to a 5-h ischemic insult by femoral artery clamping (I/R and I/R+MK-801 groups; n=48 per group). I/R+MK-801 rats were intraperitoneally injected with MK-801 (0.5 ml or 1 mg/kg) at 15 min prior to reperfusion. The rats were sacrificed at 0, 6, 12, 24, 72 h, or 7 days following reperfusion. Plasma malondialdehyde (MDA) and nitric oxide (NO) concentrations, and SN inducible NO synthase (iNOS) protein expression levels, were measured using colorimetry. In addition, the protein expression levels of tumor necrosis factor-α (TNF-α) were measured using immunohistochemistry, and histological analyses of the rat SN were conducted using light and electron microscopy. Alterations in the mRNA expression levels of TNF-α and TNF-α converting enzyme (TACE) in the rat SN were detected using reverse transcription-quantitative polymerase chain reaction. In the I/R group, plasma concentrations of NO (175.3±4.2 µmol/l) and MDA (16.2±1.9 mmol/l), and the levels of iNOS (2.5±0.3) in the SN, peaked at 24 h post-reperfusion. At 24 h, pretreatment with MK-801 significantly reduced plasma NO (107.3±3.6 µmol/l) and MDA (11.8±1.6 mmol/l), and SN iNOS (1.65±0.2) levels (all P<0.01). The mRNA expression levels of TNF-α and TACE in the SN were significantly reduced in the I/R+MK-801 group, as compared with the I/R group (P<0.05). Furthermore, MK-801 pretreatment was shown to have alleviated histological signs of I/R injury, including immune cell infiltration and axon demyelination. The results of the present study suggested that pretreatment

  3. Osteopontin protects against hyperoxia-induced lung injury by inhibiting nitric oxide synthases.

    PubMed

    Zhang, Xiang-Feng; Liu, Shuang; Zhou, Yu-Jie; Zhu, Guang-Fa; Foda, Hussein D

    2010-04-05

    Exposure of adult mice to more than 95% O(2) produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS. One hundred and forty-four osteopontin knock-out (KO) mice and their matched wild type background control (WT) were exposed in sealed cages > 95% oxygen or room air for 24- 72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase (eNOS) and iNOS mRNA in lung tissues at 24, 48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction (RT-PCR); immunohistochemistry (IHC) was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues. OPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85 +/- 0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31 +/- 0.92 in the WT group (P < 0.05). iNOS mRNA (48 hours: 1.04 +/- 0.08 vs. 0.63 +/- 0.09, P < 0.01; 72 hours: 0.89 +/- 0.08 vs. 0.72 +/- 0.09, P < 0.05) and eNOS mRNA (48 hours: 0.62 +/- 0.08 vs. 0.43 +/- 0.09, P < 0.05; 72 hours: 0.67 +/- 0.08 vs. 0.45 +/- 0.09, P < 0.05) expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS (20.54 +/- 3.18 vs. 12.52 +/- 2.46, P < 0.05) and eNOS (19.83 +/- 5.64 vs. 9.45 +/- 3.82, P < 0.05) in lung tissues of OPN KO mice at 72 hours of hyperoxia. OPN can protect against

  4. Inhibition of nicotinic acetylcholine receptors, a novel facet in the pleiotropic activities of snake venom phospholipases A2.

    PubMed

    Vulfius, Catherine A; Kasheverov, Igor E; Starkov, Vladislav G; Osipov, Alexey V; Andreeva, Tatyana V; Filkin, Sergey Yu; Gorbacheva, Elena V; Astashev, Maxim E; Tsetlin, Victor I; Utkin, Yuri N

    2014-01-01

    Phospholipases A2 represent the most abundant family of snake venom proteins. They manifest an array of biological activities, which is constantly expanding. We have recently shown that a protein bitanarin, isolated from the venom of the puff adder Bitis arietans and possessing high phospholipolytic activity, interacts with different types of nicotinic acetylcholine receptors and with the acetylcholine-binding protein. To check if this property is characteristic to all venom phospholipases A2, we have studied the capability of these enzymes from other snakes to block the responses of Lymnaea stagnalis neurons to acetylcholine or cytisine and to inhibit α-bungarotoxin binding to nicotinic acetylcholine receptors and acetylcholine-binding proteins. Here we present the evidence that phospholipases A2 from venoms of vipers Vipera ursinii and V. nikolskii, cobra Naja kaouthia, and krait Bungarus fasciatus from different snake families suppress the acetylcholine- or cytisine-elicited currents in L. stagnalis neurons and compete with α-bungarotoxin for binding to muscle- and neuronal α7-types of nicotinic acetylcholine receptor, as well as to acetylcholine-binding proteins. As the phospholipase A2 content in venoms is quite high, under some conditions the activity found may contribute to the deleterious venom effects. The results obtained suggest that the ability to interact with nicotinic acetylcholine receptors may be a general property of snake venom phospholipases A2, which add a new target to the numerous activities of these enzymes.

  5. Inhibition of Nicotinic Acetylcholine Receptors, a Novel Facet in the Pleiotropic Activities of Snake Venom Phospholipases A2

    PubMed Central

    Vulfius, Catherine A.; Kasheverov, Igor E.; Starkov, Vladislav G.; Osipov, Alexey V.; Andreeva, Tatyana V.; Filkin, Sergey Yu.; Gorbacheva, Elena V.; Astashev, Maxim E.; Tsetlin, Victor I.; Utkin, Yuri N.

    2014-01-01

    Phospholipases A2 represent the most abundant family of snake venom proteins. They manifest an array of biological activities, which is constantly expanding. We have recently shown that a protein bitanarin, isolated from the venom of the puff adder Bitis arietans and possessing high phospholipolytic activity, interacts with different types of nicotinic acetylcholine receptors and with the acetylcholine-binding protein. To check if this property is characteristic to all venom phospholipases A2, we have studied the capability of these enzymes from other snakes to block the responses of Lymnaea stagnalis neurons to acetylcholine or cytisine and to inhibit α-bungarotoxin binding to nicotinic acetylcholine receptors and acetylcholine-binding proteins. Here we present the evidence that phospholipases A2 from venoms of vipers Vipera ursinii and V. nikolskii, cobra Naja kaouthia, and krait Bungarus fasciatus from different snake families suppress the acetylcholine- or cytisine-elicited currents in L. stagnalis neurons and compete with α-bungarotoxin for binding to muscle- and neuronal α7-types of nicotinic acetylcholine receptor, as well as to acetylcholine-binding proteins. As the phospholipase A2 content in venoms is quite high, under some conditions the activity found may contribute to the deleterious venom effects. The results obtained suggest that the ability to interact with nicotinic acetylcholine receptors may be a general property of snake venom phospholipases A2, which add a new target to the numerous activities of these enzymes. PMID:25522251

  6. Ammodytoxin, a secretory phospholipase A2, inhibits G2 cell-cycle arrest in the yeast Saccharomyces cerevisiae.

    PubMed

    Petrovic, Uros; Sribar, Jernej; Matis, Maja; Anderluh, Gregor; Peter-Katalinić, Jasna; Krizaj, Igor; Gubensek, Franc

    2005-10-15

    Ammodytoxin (Atx), an sPLA2 (secretory phospholipase A2), binds to g and e isoforms of porcine 14-3-3 proteins in vitro. 14-3-3 proteins are evolutionarily conserved eukaryotic regulatory proteins involved in a variety of biological processes, including cell-cycle regulation. We have now shown that Atx binds to yeast 14-3-3 proteins with an affinity similar to that for the mammalian isoforms. Thus yeast Saccharomyces cerevisiae can be used as a model eukaryotic cell, which lacks endogenous phospholipases A2, to assess the in vivo relevance of this interaction. Atx was expressed in yeast cells and shown to be biologically active inside the cells. It inhibited G2 cell-cycle arrest in yeast, which is regulated by 14-3-3 proteins. Interference with the cell cycle indicates a possible mechanism by which sPLA2s are able to cause the opposing effects, proliferation and apoptosis, in mammalian cells.

  7. Calpain Inhibition Is Protective in Machado-Joseph Disease Zebrafish Due to Induction of Autophagy.

    PubMed

    Watchon, Maxinne; Yuan, Kristy C; Mackovski, Nick; Svahn, Adam J; Cole, Nicholas J; Goldsbury, Claire; Rinkwitz, Silke; Becker, Thomas S; Nicholson, Garth A; Laird, Angela S

    2017-08-09

    , which can be used in rapid drug testing studies. We have found that treating the MJD zebrafish with the calpain inhibitor compound calpeptin produces complete removal of human ataxin-3 protein, due to induction of the autophagy quality control pathway. This improves the movement of the MJD zebrafish. Artificially blocking the autophagy pathway prevents the removal of human ataxin-3 and improved movement produced by calpeptin treatment. These findings indicate that induction of autophagy, and removal of ataxin-3 protein, plays an important role in the protective effects of calpain inhibition for the treatment of MJD. Copyright © 2017 the authors 0270-6474/17/377782-13$15.00/0.

  8. Mechanism study of endothelial protection and inhibits platelet activation of low molecular weight fucoidan from Laminaria japonica

    NASA Astrophysics Data System (ADS)

    Chen, Anjin; Zhang, Fang; Shi, Jie; Zhao, Xue; Yan, Meixing

    2016-10-01

    Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline (0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. vWF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce vWF level in vascular endothelial injury rats and also significantly reduce vWF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and vWF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.

  9. A novel approach to the design of inhibitors of human secreted phospholipase A2 based on native peptide inhibition.

    PubMed

    Church, W B; Inglis, A S; Tseng, A; Duell, R; Lei, P W; Bryant, K J; Scott, K F

    2001-08-31

    Human Type IIA secreted phospholipase A(2) (sPLA(2)-IIA) is an important modulator of cytokine-dependent inflammatory responses and a member of a growing superfamily of structurally related phospholipases. We have previously shown that sPLA(2)-IIA is inhibited by a pentapeptide sequence comprising residues 70-74 of the native sPLA(2)-IIA protein and that peptides derived from the equivalent region of different sPLA(2)-IIA species specifically inhibit the enzyme from which they are derived. We have now used an analogue screen of the human pentapeptide (70)FLSYK(74) in which side-chain residues were substituted, together with molecular docking approaches that modeled low-energy conformations of (70)FLSYK(74) bound to human sPLA(2)-IIA, to generate inhibitors with improved potency. Importantly, the modeling studies showed a close association between the NH(2) and COOH termini of the peptide, predicting significant enhancement of the potency of inhibition by cyclization. Cyclic compounds were synthesized and indeed showed 5-50-fold increased potency over the linear peptide in an Escherichia coli membrane assay. Furthermore, the potency of inhibition correlated with steady-state binding of the cyclic peptides to sPLA(2)-IIA as determined by surface plasmon resonance studies. Two potential peptide interaction sites were identified on sPLA(2)-IIA from the modeling studies, one in the NH(2)-terminal helix and the other in the beta-wing region, and in vitro association assays support the potential for interaction of the peptides with these sites. The inhibitors were effective at nanomolar concentrations in blocking sPLA(2)-IIA-mediated amplification of cytokine-induced prostaglandin synthesis in human rheumatoid synoviocytes in culture. These studies provide an example where native peptide sequences can be used for the development of potent and selective inhibitors of enzyme function.

  10. Astragaloside IV inhibited the activity of CYP1A2 in liver microsomes and influenced theophylline pharmacokinetics in rats.

    PubMed

    Zhang, Yan-Hui; Zhang, You-Jin; Guo, Yan-Lei; Li, Wen-Juan; Yu, Chao

    2013-01-01

    With the growing popularity of herbal and natural medicinal products, attention has turned to possible interactions between these products and pharmaceutical drugs. In this study, we examined whether astragaloside IV (AGS-IV) could inhibit the activity of CYP1A2 in rat liver microsomes in vitro and in vivo. The effect of AGS-IV on CYP1A2 activity was investigated using probe substrates: phenacetin in vitro and theophylline in vivo. Phenacetin was incubated in rat liver microsomes with or without AGS-IV, and the mechanism, kinetics and type of inhibition were determined. The inhibitory effect of AGS-IV on CYP1A2 activity in rats was also determined using theophylline in vivo. The pharmacokinetics of theophylline were observed after a single or week-long treatment with AGS-IV. AGS-IV was found to be a competitive inhibitor with a K(i) value of 6.29 μM in vitro. In the multiple-pretreatment rat group, it was found to have a significantly higher area under the concentration-time curve (AUC) for theophylline, as well as a lower apparent oral total body clearance value (CL/F). In contrast, no significant difference in metabolism of theophylline was found for the single pretreatment group. These findings suggest that AGS-IV is a potent inhibitor of CYP1A2. This work offers a useful reference for the reasonable and safe use of clinically prescribed herbal or natural products to avoid unnecessary herb-drug interactions. © 2012 The Authors. JPP © 2012. Royal Pharmaceutical Society.

  11. Leishmania amazonensis impairs DC function by inhibiting CD40 expression via A2B adenosine receptor activation.

    PubMed

    Figueiredo, Amanda B; Serafim, Tiago D; Marques-da-Silva, Eduardo A; Meyer-Fernandes, José R; Afonso, Luís C C

    2012-05-01

    Dendritic cells (DCs) play an essential role in the modulation of immune responses and several studies have evaluated the interactions between Leishmania parasites and DCs. While extracellular ATP exhibits proinflammatory properties, adenosine is an important anti-inflammatory mediator. Here we investigated the effects of Leishmania infection on DC responses and the participation of purinergic signalling in this process. Bone marrow-derived dendritic cells (BMDCs) from C57BL/6J mice infected with Leishmania amazonensis, Leishmania braziliensis or Leishmania major metacyclic promastigotes showed decreased major histocompatibility complex (MHC) class II and CD86 expression and increased ectonucleotidase expression as compared with uninfected cells. In addition, L. amazonensis-infected DCs, which had lower CD40 expression, exhibited a decreased ability to induce T-cell proliferation. The presence of MRS1754, a highly selective A(2B) adenosine receptor antagonist at the time of infection increased MHC class II, CD86 and CD40 expression in L. amazonensis-infected DCs and restored the ability of the infected DCs to induce T-cell proliferation. Similar results were obtained through the inhibition of extracellular ATP hydrolysis using suramin. In conclusion, we propose that A(2B) receptor activation may be used by L. amazonensis to inhibit DC function and evade the immune response. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Bilobalide, a constituent of Ginkgo biloba, inhibits NMDA-induced phospholipase A2 activation and phospholipid breakdown in rat hippocampus.

    PubMed

    Weichel, O; Hilgert, M; Chatterjee, S S; Lehr, M; Klein, J

    1999-12-01

    In rat hippocampal slices superfused with magnesium-free buffer, glutamate (1 mM) caused the release of large amounts of choline due to phospholipid breakdown. This phenomenon was mimicked by N-methyl-D-aspartate (NMDA) in a calcium-sensitive manner and was blocked by NMDA receptor antagonists such as MK-801 and 7-chlorokynurenate. The NMDA-induced release of choline was not caused by activation of phospholipase D but was mediated by phospholipase A2 (PLA2) activation as the release of choline was accompanied by the formation of lyso-phosphatidylcholine (lyso-PC) and glycerophospho-choline (GPCh) and was blocked by 5-[2-(2-carboxyethyl)-4-dodecanoyl-3,5-dimethylpyrrol-1-yl]pentano ic acid, a PLA2 inhibitor. Bilobalide, a constituent of Ginkgo biloba, inhibited the NMDA-induced efflux of choline with an IC50 value of 2.3 microM and also prevented the formation of lyso-PC and GPCh. NMDA also caused a release of choline in vivo when infused into the hippocampus of freely moving rats by retrograde dialysis. Again, the effect was completely inhibited by bilobalide which was administered systemically (20 mg/kg i.p.). Interestingly, convulsions which were observed in the NMDA-treated rats were almost totally suppressed by bilobalide. We conclude that release of choline is a sensitive marker for NMDA-induced phospholipase A2 activation and phospholipid breakdown. Bilobalide inhibited the glutamatergic excitotoxic membrane breakdown both in vitro and in vivo, an effect which may be beneficial in the treatment of brain hypoxia and/or neuronal hyperactivity.

  13. Inhibition of Cx43 mediates protective effects on hypoxic/reoxygenated human neuroblastoma cells.

    PubMed

    Vicario, Nunzio; Calabrese, Giovanna; Zappalà, Agata; Parenti, Carmela; Forte, Stefano; Graziano, Adriana Carol Eleonora; Vanella, Luca; Pellitteri, Rosalia; Cardile, Venera; Parenti, Rosalba

    2017-10-01

    Olfactory ensheathing cells (OECs), a special population of glial cells, are able to synthesise several trophic factors exerting a neuroprotective action and promoting growth and functional recovery in both in vitro and in vivo models. In the present work, we investigated the neuroprotective effects of OEC-conditioned medium (OEC-CM) on two different human neuron-like cell lines, SH-SY5Y and SK-N-SH (neuroblastoma cell lines), under normoxic and hypoxic conditions. In addition, we also focused our attention on the role of connexins (Cxs) in the neuroprotective processes. Our results confirmed OEC-CM mediated neuroprotection as shown by cell adherence, proliferation and cellular viability analyses. Reduced connexin 43 (Cx43) levels in OEC-CM compared to unconditioned cells in hypoxic conditions prompted us to investigate the role of Cx43-Gap junctions (GJs) and Cx43-hemichannels (HCs) in hypoxic/reoxygenation injury using carbenoxolone (non-selective GJ inhibitor), ioxynil octanoato (selective Cx43-GJ inhibitor) and Gap19 (selective Cx43-HC inhibitor). We found that Cx43-GJ and Cx43-HC inhibitors are able to protect SH-SY5Y and allow to these cultures to overcome the injury. Our findings support the hypothesis that both OEC-CM and the inhibition of Cx43-GJs and Cx43-HCs offer a neuroprotective effect by reducing Cx43-mediated cell-to-cell and cell-to-extracellular environment communications. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  14. Taurine protects against methotrexate-induced toxicity and inhibits leukocyte death

    SciTech Connect

    Cetiner, Mustafa; Sener, Goeksel; Sehirli, A. Ozer; Eksioglu-Demiralp, Emel; Ercan, Feriha; Sirvanci, Serap; Gedik, Nursal; Akpulat, Sertac; Tecimer, Tuelay; Yegen, Berrak C. . E-mail: byegen@marmara.edu.tr

    2005-11-15

    The efficacy of methotrexate (MTX), a widely used cytotoxic chemotherapeutic agent, is often limited by severe side effects and toxic sequelae. Regarding the mechanisms of these side effects, several hypotheses have been put forward, among which oxidative stress is noticeable. The present study was undertaken to determine whether taurine, a potent free radical scavenger, could ameliorate MTX-induced oxidative injury and modulate immune response. Following a single dose of methotrexate (20 mg/kg), either saline or taurine (50 mg/kg) was administered for 5 days. After decapitation of the rats, trunk blood was obtained and the ileum, liver, and kidney were removed to measure malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and collagen content, as well as histological examination. Our results showed that MTX administration increased the MDA, MPO activity, and collagen contents and decreased GSH levels in all tissues (P < 0.001), while these alterations were reversed in taurine-treated group (P < 0.05-0.01). Elevated (P < 0.001) TNF-{alpha} level observed following MTX treatment was depressed with taurine (P < 0.01). Oxidative burst of neutrophils stimulated by phorbol myristate acetate was reduced in saline-treated MTX group (P < 0.001), while taurine abolished this effect. Similarly, flow cytometric measurements revealed that leukocyte apoptosis and cell death were increased in MTX-treated animals, while taurine reversed these effects (P < 0.05). Reduced cellularity in bone marrow samples of MTX-treated group (P < 0.01) was reversed back to control levels in taurine-treated rats. Severe degeneration of the intestinal mucosa, liver parenchyma, glomerular, and tubular epithelium observed in saline-treated group was improved by taurine treatment. In conclusion, it appears that taurine protects against methotrexate-induced oxidant organ injury and inhibits leukocyte apoptosis and may be of therapeutic potential in alleviating the

  15. Use of dietary rosemary diterpenes to inhibit rancid volatiles in lamb meat packed under protective atmosphere.

    PubMed

    Ortuño, J; Serrano, R; Bañón, S

    2016-08-01

    The objective of the present study was to determine the inhibitory effect of dietary rosemary diterpenes on the formation of the volatile organic compounds (VOCs) responsible for rancid flavour in raw lamb meat. The lamb diet was supplemented during the fattening stage with two levels (200 and 400 mg/kg feed) of a dietary rosemary extract (DRE) containing carnosic acid and carnosol (1 : 1, w/w). The formation of VOCs (determined by headspace solid-phase microextraction at 40°C and MS) and odour deterioration (assessed by quantitative descriptive analysis) were monitored in meat fillets (longissimus dorsi-lumborum muscle) packed in a 70/30 O2/CO2 protective atmosphere and kept at 2°C for up to 14 days. The raw meat odour deteriorated under pro-oxidizing conditions due to the development of an incipient rancidity caused by the formation of volatiles from lipid oxidation. A total of 46 volatile compounds were determined in lamb headspace: 18 aldehydes, seven alcohols, seven organic acids, six ketones, four furan compounds, two benzene compounds, one ester and one terpenoid. The use of DRE contributed to inhibit VOC formation and rancidity. Heptanal, octanal, nonanal and 2-pentyl-furan were the only VOCs affected (P0.75; P<0.001), although similar values were obtained for the coefficients of a large number of carbonyl, alcohols and furan compounds, among other volatiles, which can be considered molecular markers of rancidity in raw lamb meat. Principal component analysis confirmed that the differences in the VOC profile make it possible to identify whether or not samples have been reinforced with dietary rosemary diterpenes. Thus, VOC profiling can be regarded as a useful tool for assessing the dietary treatments used in sheep to improve the oxidative stability of lamb meat.

  16. Acacetin Protects Mice from Staphylococcus aureus Bloodstream Infection by Inhibiting the Activity of Sortase A.

    PubMed

    Bi, Chongwei; Dong, Xiaoyun; Zhong, Xiaobo; Cai, Hongjun; Wang, Dacheng; Wang, Lin

    2016-09-26

    Staphylococcus aureus (S. aureus) is a major cause of infection in hospitals and communities. Widespread dissemination of multi-drug resistant S. aureus is a serious threat to the health of humans and animals. An anti-virulence strategy has been widely considered as an alternative therapeutic approach. Inhibitors of virulence factors are able to treat S. aureus infections without influencing the growth or viability of bacteria and rarely lead to bacterial resistance. Sortase A (SrtA) is a membrane-associated cysteine transpeptidase that catalyzes up to 25 surface proteins that covalently bind to cell wall peptidoglycans. In S. aureus, most of these surface proteins have been identified as important virulence factors that are vital in bacterial pathogenesis. In the present study, we show that acacetin, a natural flavonoid compound, inhibits the activity of SrtA in S. aureus (IC50 = 36.46 ± 4.69 μg/mL, 128 μM) which affects the assembly of protein A (SpA) to cell walls and reduces the binding of S. aureus to fibrinogen (Fg). The mechanism of the interaction between acacetin and SrtA were preliminarily discussed using molecular dynamics simulations. The results suggested that acacetin adopted a compact conformation binding at the pocket of the SrtA via residues Arg-139 and Lys-140. By performing an animal infection model, we demonstrated that acacetin was able to protect mice from renal abscess formation induced by S. aureus and significantly increased survival rates. Taken together, these findings suggest that acacetin may be a promising candidate for the development of anti-S. aureus drugs.

  17. Mucosal Immunization with Vibrio cholerae Outer Membrane Vesicles Provides Maternal Protection Mediated by Antilipopolysaccharide Antibodies That Inhibit Bacterial Motility▿ †

    PubMed Central

    Bishop, Anne L.; Schild, Stefan; Patimalla, Bharathi; Klein, Brian; Camilli, Andrew

    2010-01-01

    Vibrio cholerae is the causative agent of cholera, a severe diarrheal disease that remains endemic in many parts of the world and can cause outbreaks wherever sanitation and clean water systems break down. Prevention of disease could be achieved through improved sanitation and clean water provision supported by vaccination. V. cholerae serogroup O1 is the major cause of cholera; O1 serotypes Inaba and Ogawa have similar disease burdens, while O139 is the only non-O1 serogroup to cause epidemics. We showed previously that immunization of adult female mice with purified V. cholerae outer membrane vesicles (OMVs) elicits an antibody response that protect neonates from oral V. cholerae challenge and that suckling from an immunized dam accounts for the majority of protection from V. cholerae colonization. Here we report that lipopolysaccharide (LPS) is the major OMV protective antigen. Mucosal immunization with OMVs from Inaba or Ogawa provides significant cross-serotype protection from V. cholerae colonization, although serotype-specific antigens are dominant. OMVs from O1 or O139 do not provide cross-serogroup protection, but by immunization with a mixture of O1 and O139 OMVs, cross-serogroup protection was achieved. Neonatal protection is not associated with significant bacterial death but may involve inhibition of motility, as antibodies from OMV-immunized mice inhibit V. cholerae motility in vitro, with trends that parallel in vivo protection. Motility assays also reveal that a higher antibody titer is required to immobilize O139 compared to O1, a phenotype that is O139 capsule dependent. PMID:20679439

  18. Selective adenosine A2A receptor agonists and antagonists protect against spinal cord injury through peripheral and central effects

    PubMed Central

    2011-01-01

    Background Permanent functional deficits following spinal cord injury (SCI) arise both from mechanical injury and from secondary tissue reactions involving inflammation. Enhanced release of adenosine and glutamate soon after SCI represents a component in the sequelae that may be responsible for resulting functional deficits. The role of adenosine A2A receptor in central ischemia/trauma is still to be elucidated. In our previous studies we have demonstrated that the adenosine A2A receptor-selective agonist CGS21680, systemically administered after SCI, protects from tissue damage, locomotor dysfunction and different inflammatory readouts. In this work we studied the effect of the adenosine A2A receptor antagonist SCH58261, systemically administered after SCI, on the same parameters. We investigated the hypothesis that the main action mechanism of agonists and antagonists is at peripheral or central sites. Methods Spinal trauma was induced by extradural compression of SC exposed via a four-level T5-T8 laminectomy in mouse. Three drug-dosing protocols were utilized: a short-term systemic administration by intraperitoneal injection, a chronic administration via osmotic minipump, and direct injection into the spinal cord. Results SCH58261, systemically administered (0.01 mg/kg intraperitoneal. 1, 6 and 10 hours after SCI), reduced demyelination and levels of TNF-α, Fas-L, PAR, Bax expression and activation of JNK mitogen-activated protein kinase (MAPK) 24 hours after SCI. Chronic SCH58261 administration, by mini-osmotic pump delivery for 10 days, improved the neurological deficit up to 10 days after SCI. Adenosine A2A receptors are physiologically expressed in the spinal cord by astrocytes, microglia and oligodendrocytes. Soon after SCI (24 hours), these receptors showed enhanced expression in neurons. Both the A2A agonist and antagonist, administered intraperitoneally, reduced expression of the A2A receptor, ruling out the possibility that the neuroprotective effects

  19. High Mobility Group A2 protects cancer cells against telomere dysfunction

    PubMed Central

    Natarajan, Suchitra; Begum, Farhana; Gim, Jeonga; Wark, Landon; Henderson, Dana; Davie, James R.

    2016-01-01

    The non-histone chromatin binding protein High Mobility Group AT-hook protein 2 (HMGA2) plays important roles in the repair and protection of genomic DNA in embryonic stem cells and cancer cells. Here we show that HMGA2 localizes to mammalian telomeres and enhances telomere stability in cancer cells. We present a novel interaction of HMGA2 with the key shelterin protein TRF2. We found that the linker (L1) region of HMGA2 contributes to this interaction but the ATI-L1-ATII molecular region of HMGA2 is required for strong interaction with TRF2. This interaction was independent of HMGA2 DNA-binding and did not require the TRF2 interacting partner RAP1 but involved the homodimerization and hinge regions of TRF2. HMGA2 retained TRF2 at telomeres and reduced telomere-dysfunction despite induced telomere stress. Silencing of HMGA2 resulted in (i) reduced binding of TRF2 to telomere DNA as observed by ChIP, (ii) increased telomere instability and (iii) the formation of telomere dysfunction-induced foci (TIF). This resulted in increased telomere aggregation, anaphase bridges and micronuclei. HMGA2 prevented ATM-dependent pTRF2T188 phosphorylation and attenuated signaling via the telomere specific ATM-CHK2-CDC25C DNA damage signaling axis. In summary, our data demonstrate a unique and novel role of HMGA2 in telomere protection and promoting telomere stability in cancer cells. This identifies HMGA2 as a new therapeutic target for the destabilization of telomeres in HMGA2+ cancer cells. PMID:26799419

  20. Subthreshold nitric oxide synthase inhibition improves synergistic effects of subthreshold MMP-2/MLCK-mediated cardiomyocyte protection from hypoxic injury.

    PubMed

    Bil-Lula, Iwona; Lin, Han-Bin; Biały, Dariusz; Wawrzyńska, Magdalena; Diebel, Lucas; Sawicka, Jolanta; Woźniak, Mieczyslaw; Sawicki, Grzegorz

    2016-06-01

    Injury of myocardium during ischaemia/reperfusion (I/R) is a complex and multifactorial process involving uncontrolled protein phosphorylation, nitration/nitrosylation by increased production of nitric oxide and accelerated contractile protein degradation by matrix metalloproteinase-2 (MMP-2). It has been shown that simultaneous inhibition of MMP-2 with doxycycline (Doxy) and myosin light chain kinase (MLCK) with ML-7 at subthreshold concentrations protects the heart from contractile dysfunction triggered by I/R in a synergistic manner. In this study, we showed that additional co-administration of nitric oxide synthase (NOS) inhibitor (1400W or L-NAME) in subthreshold concentrations improves this synergistic protection in the model of hypoxia-reoxygenation (H-R)-induced contractile dysfunction of cardiomyocytes. Isolated cardiomyocytes were subjected to 3 min. of hypoxia and 20 min. of reoxygenation in the presence or absence of the inhibitor cocktails. Contractility of cardiomyocytes was expressed as myocyte peak shortening. Inhibition of MMP-2 by Doxy (25-100 μM), MLCK by ML-7 (0.5-5 μM) and NOS by L-NAME (25-100 μM) or 1400W (25-100 μM) protected myocyte contractility after H-R in a concentration-dependent manner. Inhibition of these activities resulted in full recovery of cardiomyocyte contractility after H-R at the level of highest single-drug concentration. The combination of subthreshold concentrations of NOS, MMP-2 and MLCK inhibitors fully protected cardiomyocyte contractility and MLC1 from degradation by MMP-2. The observed protection with addition of L-NAME or 1400W was better than previously reported combination of ML-7 and Doxy. The results of this study suggest that addition of NOS inhibitor to the mixture of inhibitors is better strategy for protecting cardiomyocyte contractility.

  1. The Tick Protein Sialostatin L2 Binds to Annexin A2 and Inhibits NLRC4-Mediated Inflammasome Activation

    PubMed Central

    Wang, Xiaowei; Shaw, Dana K.; Sakhon, Olivia S.; Snyder, Greg A.; Sundberg, Eric J.; Santambrogio, Laura; Sutterwala, Fayyaz S.; Dumler, J. Stephen; Shirey, Kari Ann; Perkins, Darren J.; Richard, Katharina; Chagas, Andrezza C.; Calvo, Eric; Kopecký, Jan; Kotsyfakis, Michail

    2016-01-01

    Tick saliva contains a number of effector molecules that inhibit host immunity and facilitate pathogen transmission. How tick proteins regulate immune signaling, however, is incompletely understood. Here, we describe that loop 2 of sialostatin L2, an anti-inflammatory tick protein, binds to annexin A2 and impairs the formation of the NLRC4 inflammasome during infection with the rickettsial agent Anaplasma phagocytophilum. Macrophages deficient in annexin A2 secreted significantly smaller amounts of interleukin-1β (IL-1β) and IL-18 and had a defect in NLRC4 inflammasome oligomerization and caspase-1 activation. Accordingly, Annexin a2-deficient mice were more susceptible to A. phagocytophilum infection and showed splenomegaly, thrombocytopenia, and monocytopenia. Providing translational support to our findings, better binding of annexin A2 to sialostatin L2 in sera from 21 out of 23 infected patients than in sera from control individuals was also demonstrated. Overall, we establish a unique mode of inflammasome evasion by a pathogen, centered on a blood-feeding arthropod. PMID:27045038

  2. Norbixin Protects Retinal Pigmented Epithelium Cells and Photoreceptors against A2E-Mediated Phototoxicity In Vitro and In Vivo

    PubMed Central

    Monteiro, Elodie; Brazhnikova, Elena; Lesage, Laëtitia; Balducci, Christine; Guibout, Louis; Feraille, Laurence; Elena, Pierre-Paul; Sahel, José-Alain; Veillet, Stanislas; Lafont, René

    2016-01-01

    The accumulation of N-retinylidene-N-retinylethanolamine (A2E, a toxic by-product of the visual pigment cycle) in the retinal pigment epithelium (RPE) is a major cause of visual impairment in the elderly. Photooxidation of A2E results in retinal pigment epithelium degeneration followed by that of associated photoreceptors. Present treatments rely on nutrient supplementation with antioxidants. 9’-cis-Norbixin (a natural diapocarotenoid, 97% purity) was prepared from Bixa orellana seeds. It was first evaluated in primary cultures of porcine retinal pigment epithelium cells challenged with A2E and illuminated with blue light, and it provided an improved photo-protection as compared with lutein or zeaxanthin. In Abca4-/- Rdh8-/- mice (a model of dry AMD), intravitreally-injected norbixin maintained the electroretinogram and protected photoreceptors against light damage. In a standard rat blue-light model of photodamage, norbixin was at least equally as active as phenyl-N-tert-butylnitrone, a free radical spin-trap. Chronic experiments performed with Abca4-/- Rdh8-/- mice treated orally for 3 months with norbixin showed a reduced A2E accumulation in the retina. Norbixin appears promising for developing an oral treatment of macular degeneration. A drug candidate (BIO201) with 9’-cis-norbixin as the active principle ingredient is under development, and its potential will be assessed in a forthcoming clinical trial. PMID:27992460

  3. Norbixin Protects Retinal Pigmented Epithelium Cells and Photoreceptors against A2E-Mediated Phototoxicity In Vitro and In Vivo.

    PubMed

    Fontaine, Valérie; Monteiro, Elodie; Brazhnikova, Elena; Lesage, Laëtitia; Balducci, Christine; Guibout, Louis; Feraille, Laurence; Elena, Pierre-Paul; Sahel, José-Alain; Veillet, Stanislas; Lafont, René

    2016-01-01

    The accumulation of N-retinylidene-N-retinylethanolamine (A2E, a toxic by-product of the visual pigment cycle) in the retinal pigment epithelium (RPE) is a major cause of visual impairment in the elderly. Photooxidation of A2E results in retinal pigment epithelium degeneration followed by that of associated photoreceptors. Present treatments rely on nutrient supplementation with antioxidants. 9'-cis-Norbixin (a natural diapocarotenoid, 97% purity) was prepared from Bixa orellana seeds. It was first evaluated in primary cultures of porcine retinal pigment epithelium cells challenged with A2E and illuminated with blue light, and it provided an improved photo-protection as compared with lutein or zeaxanthin. In Abca4-/- Rdh8-/- mice (a model of dry AMD), intravitreally-injected norbixin maintained the electroretinogram and protected photoreceptors against light damage. In a standard rat blue-light model of photodamage, norbixin was at least equally as active as phenyl-N-tert-butylnitrone, a free radical spin-trap. Chronic experiments performed with Abca4-/- Rdh8-/- mice treated orally for 3 months with norbixin showed a reduced A2E accumulation in the retina. Norbixin appears promising for developing an oral treatment of macular degeneration. A drug candidate (BIO201) with 9'-cis-norbixin as the active principle ingredient is under development, and its potential will be assessed in a forthcoming clinical trial.

  4. IGFBP-3 inhibits TNF-α production and TNFR-2 signaling to protect against retinal endothelial cell apoptosis.

    PubMed

    Zhang, Qiuhua; Steinle, Jena J

    2014-09-01

    In models of diabetic retinopathy, insulin-like growth factor binding protein-3 (IGFBP-3) protects against tumor necrosis factors-alpha (TNF-α)-mediated apoptosis of retinal microvascular endothelial cells (REC), but the underlying mechanisms are unclear. Our current findings suggest that at least two discrete but complimentary pathways contribute to the protective effects of IGFBP-3; 1) IGFBP-3 directly activates the c-Jun kinase/tissue inhibitor of metalloproteinase-3/TNF-α converting enzyme (c-Jun/TIMP-3/TACE), pathway, which in turn inhibits TNF-α production; 2) IGFBP-3 acts through the IGFBP-3 receptor, low-density lipoprotein receptor-related protein 1 (LRP1), to inhibit signaling of TNF-α receptor 2 (TNFR2). Combined, these two IGFBP-3 pathways substantially reduce REC apoptosis and offer potential targets for the treatment of diabetic retinopathy.

  5. Inhibition of Drp1 mitochondrial translocation provides neural protection in dopaminergic system in a Parkinson's disease model induced by MPTP.

    PubMed

    Filichia, Emily; Hoffer, Barry; Qi, Xin; Luo, Yu

    2016-09-13

    Accumulating evidence suggest mitochondria-mediated pathways play an important role in dopaminergic neuronal cell death in Parkinson's disease (PD). Drp1, a key regulator of mitochondrial fission, has been shown to be activated and translocated to mitochondria under stress, leading to excessive mitochondria fission and dopaminergic neuronal death in vitro. However, whether Drp1 inhibition can lead to long term stable preservation of dopaminergic neurons in PD-related mouse models remains unknown. In this study, using a classical MPTP animal PD model, we showed for the first time Drp1 activation and mitochondrial translocation in vivo after MPTP administration. Inhibition of Drp1 activation by a selective peptide inhibitor P110, blocked MPTP-induced Drp1 mitochondrial translocation and attenuated dopaminergic neuronal loss, dopaminergic nerve terminal damage and behavioral deficits caused by MPTP. MPTP-induced microglial activation and astrogliosis were not affected by P110 treatment. Instead, inhibition of Drp1 mitochondrial translocation diminished MPTP-induced p53, BAX and PUMA mitochondrial translocation. This study demonstrates that inhibition of Drp1 hyperactivation by a Drp1 peptide inhibitor P110 is neuroprotective in a MPTP animal model. Our data also suggest that the protective effects of P110 treatment might be mediated by inhibiting the p53 mediated apoptotic pathways in neurons through inhibition of Drp1-dependent p53 mitochondrial translocation.

  6. Annexin A1 reduces inflammatory reaction and tissue damage through inhibition of phospholipase A2 activation in adult rats following spinal cord injury.

    PubMed

    Liu, Nai-Kui; Zhang, Yi Ping; Han, Shu; Pei, Jiong; Xu, Lisa Y; Lu, Pei-Hua; Shields, Christopher B; Xu, Xiao-Ming

    2007-10-01

    Annexin A1 (ANXA1) has been suggested to be a mediator of the anti-inflammatory actions of glucocorticoids and more recently an endogenous neuroprotective agent. In the present study, we investigated the anti-inflammatory and neuroprotective effects of ANXA1 in a model of contusive spinal cord injury (SCI). Here we report that injections of ANXA1 (Ac 2-26) into the acutely injured spinal cord at 2 concentrations (5 and 20 microg) inhibited SCI-induced increases in phospholipase A2 and myeloperoxidase activities. In addition, ANXA1 administration reduced the expression of interleukin-1beta and activated caspase-3 at 24 hours, and glial fibrillary acidic protein at 4 weeks postinjury. Furthermore, ANXA1 administration significantly reversed phospholipase A2-induced spinal cord neuronal death in vitro and reduced tissue damage and increased white matter sparing in vivo, compared to the vehicle-treated controls. Fluorogold retrograde tracing showed that ANXA1 administration protected axons of long descending pathways at 6 weeks post-SCI. ANXA1 administration also significantly increased the number of animals that responded to transcranial magnetic motor-evoked potentials. However, no measurable behavioral improvement was found after these treatments. These results, particularly the improvements obtained in tissue sparing and electrophysiologic measures, suggest a neuroprotective effect of ANXA1.

  7. Prevention of gallbladder hypomotility via FATP2 inhibition protects from lithogenic diet-induced cholelithiasis

    PubMed Central

    Khalifeh-Soltani, Amin; Park, Hyo Min; Yurek, David A.; Falcon, Alaric; Wong, Louis; Feng, Rouying; Atabai, Kamran

    2016-01-01

    Gallstone disease is a widespread disorder costing billions for annual treatment in the United States. The primary mechanisms underlying gallstone formation are biliary cholesterol supersaturation and gallbladder hypomotility. The relative contribution of these two processes has been difficult to dissect, as experimental lithogenic diets cause both bile supersaturation and alterations in gallbladder motility. Importantly, there is no mechanistic explanation for obesity as a major risk factor for cholelithiasis. We discovered that lithogenic diets induce ectopic triacylglycerol (TAG) accumulation, a major feature of obesity and a known muscle contraction impairing condition. We hypothesized that prevention of TAG accumulation in gallbladder walls may prevent gallbladder contractile dysfunction without impacting biliary cholesterol saturation. We utilized adeno-associated virus-mediated knock down of the long-chain fatty acid transporter 2 (FATP2; Slc27A2), which is highly expressed by gallbladder epithelial cells, to downregulate lithogenic diet-associated TAG accumulation. FATP2-knockdown significantly reduced gallbladder TAG, but did not affect key bile composition parameters. Importantly, measurements with force displacement transducers showed that contractile strength in FATP2-knockdown gallbladders was significantly greater than in control gallbladders following lithogenic diet administration, and the magnitude of this effect was sufficient to prevent the formation of gallstones. FATP2-driven fatty acid uptake and the subsequent TAG accumulation in gallbladder tissue plays a pivotal role in cholelithiasis, and prevention of this process can protect from gallstone formation, even in the context of supersaturated bile cholesterol levels, thus pointing to new treatment approaches and targets. PMID:27033116

  8. Crystal structures of human group-VIIA phospholipase A2 inhibited by organophosphorus nerve agents exhibit non-aged complexes

    SciTech Connect

    Samanta, Uttamkumar; Kirby, Stephen D.; Srinivasan, Prabhavathi; Cerasoli, Douglas M.; Bahnson, Brian J.

    2009-09-02

    The enzyme group-VIIA phospholipase A2 (gVIIA-PLA2) is bound to lipoproteins in human blood and hydrolyzes the ester bond at the sn-2 position of phospholipid substrates with a short sn-2 chain. The enzyme belongs to a serine hydrolase superfamily of enzymes, which react with organophosphorus (OP) nerve agents. OPs ultimately exert their toxicity by inhibiting human acetycholinesterase at nerve synapses, but may additionally have detrimental effects through inhibition of other serine hydrolases. We have solved the crystal structures of gVIIA-PLA2 following inhibition with the OPs diisopropylfluorophosphate, sarin, soman and tabun. The sarin and soman complexes displayed a racemic mix of P{sub R} and P{sub S} stereoisomers at the P-chiral center. The tabun complex displayed only the P{sub R} stereoisomer in the crystal. In all cases, the crystal structures contained intact OP adducts that had not aged. Aging refers to a secondary process OP complexes can go through, which dealkylates the nerve agent adduct and results in a form that is highly resistant to either spontaneous or oxime-mediated reactivation. Non-aged OP complexes of the enzyme were corroborated by trypsin digest and matrix-assisted laser desorption ionization mass spectrometry of OP-enzyme complexes. The lack of stereoselectivity of sarin reaction was confirmed by gas chromatography/mass spectrometry using a chiral column to separate and quantitate the unbound stereoisomers of sarin following incubation with enzyme. The structural details and characterization of nascent reactivity of several toxic nerve agents is discussed with a long-term goal of developing gVIIA-PLA2 as a catalytic bioscavenger of OP nerve agents.

  9. An update on polygalacturonase-inhibiting protein (PGIP), a leucine-rich repeat protein that protects crop plants against pathogens

    PubMed Central

    Kalunke, Raviraj M.; Tundo, Silvio; Benedetti, Manuel; Cervone, Felice; De Lorenzo, Giulia; D'Ovidio, Renato

    2015-01-01

    Polygalacturonase inhibiting proteins (PGIPs) are cell wall proteins that inhibit the pectin-depolymerizing activity of polygalacturonases secreted by microbial pathogens and insects. These ubiquitous inhibitors have a leucine-rich repeat structure that is strongly conserved in monocot and dicot plants. Previous reviews have summarized the importance of PGIP in plant defense and the structural basis of PG-PGIP interaction; here we update the current knowledge about PGIPs with the recent findings on the composition and evolution of pgip gene families, with a special emphasis on legume and cereal crops. We also update the information about the inhibition properties of single pgip gene products against microbial PGs and the results, including field tests, showing the capacity of PGIP to protect crop plants against fungal, oomycetes and bacterial pathogens. PMID:25852708

  10. Inhibition of COX-1 attenuates the formation of thromboxane A2 and ameliorates the acute decrease in glomerular filtration rate in endotoxemic mice.

    PubMed

    Mederle, Katharina; Meurer, Manuel; Castrop, Hayo; Höcherl, Klaus

    2015-08-15

    Thromboxane (Tx) A2 has been suggested to be involved in the development of sepsis-induced acute kidney injury (AKI). Therefore, we investigated the impact of cyclooxygenase (COX)-1 and COX-2 activity on lipopolysaccharide (LPS)-induced renal TxA2 formation, and on endotoxemia-induced AKI in mice. Injection of LPS (3 mg/kg ip) decreased glomerular filtration rate (GFR) and the amount of thrombocytes to ∼50% of basal values after 4 h. Plasma and renocortical tissue levels of TxB2 were increased ∼10- and 1.7-fold in response to LPS, respectively. The COX-1 inhibitor SC-560 attenuated the LPS-induced fall in GFR and in platelet count to ∼75% of basal levels. Furthermore, SC-560 abolished the increase in plasma and renocortical tissue levels of TxB2 in response to LPS. The COX-2 inhibitor SC-236 further enhanced the LPS-induced decrease in GFR to ∼40% of basal values. SC-236 did not alter thrombocyte levels nor the LPS-induced increase in plasma and renocortical tissue levels of TxB2. Pretreatment with clopidogrel inhibited the LPS-induced drop in thrombocyte count, but did not attenuate the LPS-induced decrease in GFR and the increase in plasma TxB2 levels. This study demonstrates that endotoxemia-induced TxA2 formation depends on the activity of COX-1. Our study further indicates that the COX-1 inhibitor SC-560 has a protective effect on the decrease in renal function in response to endotoxin. Therefore, our data support a role for TxA2 in the development of AKI in response to LPS. Copyright © 2015 the American Physiological Society.

  11. Inhibition of PKR protects against H2O2-induced injury on neonatal cardiac myocytes by attenuating apoptosis and inflammation

    PubMed Central

    Wang, Yongyi; Men, Min; Xie, Bo; Shan, Jianggui; Wang, Chengxi; Liu, Jidong; Zheng, Hui; Yang, Wengang; Xue, Song; Guo, Changfa

    2016-01-01

    Reactive oxygenation species (ROS) generated from reperfusion results in cardiac injury through apoptosis and inflammation, while PKR has the ability to promote apoptosis and inflammation. The aim of the study was to investigate whether PKR is involved in hydrogen peroxide (H2O2) induced neonatal cardiac myocytes (NCM) injury. In our study, NCM, when exposed to H2O2, resulted in persistent activation of PKR due to NCM endogenous RNA. Inhibition of PKR by 2-aminopurine (2-AP) or siRNA protected against H2O2 induced apoptosis and injury. To elucidate the mechanism, we revealed that inhibition of PKR alleviated H2O2 induced apoptosis companied by decreased caspase3/7 activity, BAX and caspase-3 expression. We also revealed that inhibition of PKR suppressed H2O2 induced NFκB pathway and NLRP3 activation. Finally, we found ADAR1 mRNA and protein expression were both induced after H2O2 treatment through STAT-2 dependent pathway. By gain and loss of ADAR1 expression, we confirmed ADAR1 modulated PKR activity. Therefore, we concluded inhibition of PKR protected against H2O2-induced injury by attenuating apoptosis and inflammation. A self-preservation mechanism existed in NCM that ADAR1 expression is induced by H2O2 to limit PKR activation simultaneously. These findings identify a novel role for PKR/ADAR1 in myocardial reperfusion injury. PMID:27929137

  12. Inhibition of microglial activation contributes to propofol-induced protection against post-cardiac arrest brain injury in rats.

    PubMed

    Wang, Wei; Lu, Rui; Feng, Da-Yun; Liang, Li-Rong; Liu, Bing; Zhang, Hui

    2015-09-01

    It has been suggested that propofol can modulate microglial activity and hence may have potential roles against neuroinflammation following brain ischemic insult. However, whether and how propofol can inhibit post-cardiac arrest brain injury via inhibition of microglia activation remains unclear. A rat model of asphyxia cardiac arrest (CA) was created followed by cardiopulmonary resuscitation. CA induced marked microglial activation in the hippocampal CA1 region, revealed by increased OX42 and P2 class of purinoceptor 7 (P2X7R) expression, as well as p38 MAPK phosphorylation. Morris water maze showed that learning and memory deficits following CA could be inhibited or alleviated by pre-treatment with the microglial inhibitor minocycline or propofol. Microglial activation was significantly suppressed likely via the P2X7R/p-p38 pathway by propofol. Moreover, hippocampal neuronal injuries after CA were remarkably attenuated by propofol. In vitro experiment showed that propofol pre-treatment inhibited ATP-induced microglial activation and release of tumor necrosis factor-α and interleukin-1β. In addition, propofol protected neurons from injury when co-culturing with ATP-treated microglia. Our data suggest that propofol pre-treatment inhibits CA-induced microglial activation and neuronal injury in the hippocampus and ultimately improves cognitive function. We proposed a possible mechanism of propofol-mediated brain protection after cardiac arrest (CA). CA induces P2X7R upregulation and p38 phosphorylation in microglia, which induces release of TNF-α and IL-1β and consequent neuronal injury. Propofol could inhibit microglial activation and alleviate neuronal damage. Our results suggest propofol-induced anti-inflammatory treatment as a plausible strategy for therapeutic intervention in post-CA brain injury.

  13. Mulberrofuran G Protects Ischemic Injury-induced Cell Death via Inhibition of NOX4-mediated ROS Generation and ER Stress.

    PubMed

    Hong, Sungeun; Kwon, Jaeyoung; Kim, Dong-Woo; Lee, Hak Ju; Lee, Dongho; Mar, Woongchon

    2017-02-01

    The aim of this study was to investigate the neuroprotective effect of mulberrofuran G (MG) in in vitro and in vivo models of cerebral ischemia. MG was isolated from the root bark of Morus bombycis. MG inhibited nicotinamide adenine dinucleotide phosphate oxidase (NOX) enzyme activity and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced NOX4 protein expression in SH-SY5Y cells. MG inhibited the expression of activated caspase-3 and caspase-9 and cleaved poly adenine dinucleotide phosphate-ribose polymerase in OGD/R-induced SH-SY5Y cells. In addition, MG protected OGD/R-induced neuronal cell death and inhibited OGD/R-induced reactive oxygen species generation in SH-SY5Y cells. In in vivo model, MG-treated groups (0.2, 1, and 5 mg/kg) reduced the infarct volume in middle cerebral artery occlusion/reperfusion-induced ischemic rats. The MG-treated groups also reduced NOX4 protein expression in middle cerebral artery occlusion/reperfusion-induced ischemic rats. Furthermore, protein expression of 78-kDa glucose-regulated protein/binding immunoglobulin protein, phosphorylated IRE1α, X-box-binding protein 1, and cytosine enhancer binding protein homologous protein, mediators of endoplasmic reticulum stress, were inhibited in MG-treated groups. Taken together, MG showed protective effect in in vitro and in vivo models of cerebral ischemia through inhibition of NOX4-mediated reactive oxygen species generation and endoplasmic reticulum stress. This finding will give an insight that inhibition of NOX enzyme activity and NOX4 protein expression could be a new potential therapeutic strategy for cerebral ischemia. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Activation of Presynaptic GABAB(1a,2) Receptors Inhibits Synaptic Transmission at Mammalian Inhibitory Cholinergic Olivocochlear–Hair Cell Synapses

    PubMed Central

    Wedemeyer, Carolina; Zorrilla de San Martín, Javier; Ballestero, Jimena; Gómez-Casati, María Eugenia; Torbidoni, Ana Vanesa; Fuchs, Paul A.; Bettler, Bernhard; Elgoyhen, Ana Belén

    2013-01-01

    The synapse between olivocochlear (OC) neurons and cochlear mechanosensory hair cells is cholinergic, fast, and inhibitory. The inhibitory sign of this cholinergic synapse is accounted for by the activation of Ca2+-permeable postsynaptic α9α10 nicotinic receptors coupled to the opening of hyperpolarizing Ca2+-activated small-conductance type 2 (SK2)K+ channels. Acetylcholine (ACh) release at this synapse is supported by both P/Q- and N-type voltage-gated calcium channels (VGCCs). Although the OC synapse is cholinergic, an abundant OC GABA innervation is present along the mammalian cochlea. The role of this neurotransmitter at the OC efferent innervation, however, is for the most part unknown. We show that GABA fails to evoke fast postsynaptic inhibitory currents in apical developing inner and outer hair cells. However, electrical stimulation of OC efferent fibers activates presynaptic GABAB(1a,2) receptors [GABAB(1a,2)Rs] that downregulate the amount of ACh released at the OC–hair cell synapse, by inhibiting P/Q-type VGCCs. We confirmed the expression of GABABRs at OC terminals contacting the hair cells by coimmunostaining for GFP and synaptophysin in transgenic mice expressing GABAB1–GFP fusion proteins. Moreover, coimmunostaining with antibodies against the GABA synthetic enzyme glutamic acid decarboxylase and synaptophysin support the idea that GABA is directly synthesized at OC terminals contacting the hair cells during development. Thus, we demonstrate for the first time a physiological role for GABA in cochlear synaptic function. In addition, our data suggest that the GABAB1a isoform selectively inhibits release at efferent cholinergic synapses. PMID:24068816

  15. Bacterial β-glucuronidase inhibition protects mice against enteropathy induced by indomethacin, ketoprofen or diclofenac: mode of action and pharmacokinetics

    PubMed Central

    Saitta, Kyle S.; Zhang, Carmen; Lee, Kang Kwang; Fujimoto, Kazunori; Redinbo, Matthew R.; Boelsterli, Urs A.

    2014-01-01

    We have previously demonstrated that a small molecule inhibitor of bacterial β-glucuronidase (Inh-1; [1-((6,8-dimethyl-2-oxo-1,2-dihydroquinolin-3-yl)-3-(4-ethoxyphenyl)-1-(2-hydroxyethyl)thiourea]) protected mice against diclofenac (DCF)-induced enteropathy. Here we report that Inh-1 was equally protective against small intestinal injury induced by other carboxylic acid-containing non-steroidal anti-inflammatory drugs (NSAIDs), indomethacin (10 mg/kg, ip) and ketoprofen (100 mg/kg, ip).Inh-1 provided complete protection if given prior to DCF (60 mg/kg, ip), and partial protection if administered 3-h post-DCF, suggesting that the temporal window of mucosal protection can be extended for drugs undergoing extensive enterohepatic circulation.Pharmacokinetic analysis of Inh-1 revealed an absolute bioavailability (F) of 21% and a short t1/2 of <1 h. This low F was shown to be due to hepatic first-pass metabolism, as confirmed with the pan-CYP inhibitor, 1-aminobenzotriazole.Using the fluorescent probe 5 (and 6)-carboxy-2′,7′-dichlorofluorescein, we demonstrated that Inh-1 did not interfere with hepatobiliary export of glucuronides in gall bladder-cannulated mice.These data are compatible with the hypothesis that pharmacological inhibition of bacterial β-glucuronidase-mediated cleavage of NSAID glucuronides in the small intestinal lumen can protect against NSAID-induced enteropathy caused by locally high concentrations of NSAID aglycones. PMID:23829165

  16. Inhibition of Histone Deacetylase 3 (HDAC3) Mediates Ischemic Preconditioning and Protects Cortical Neurons against Ischemia in Rats

    PubMed Central

    Wu, Qimei; Zhang, Lei; Feng, Linyin

    2016-01-01

    Brain ischemic preconditioning (PC) provides vital insights into the endogenous protection against stroke. Genomic and epigenetic responses to PC condition the brain into a state of ischemic tolerance. Notably, PC induces the elevation of histone acetylation, consistent with evidence that histone deacetylase (HDAC) inhibitors protect the brain from ischemic injury. However, less is known about the specific roles of HDACs in this process. HDAC3 has been implicated in several neurodegenerative conditions. Deletion of HDAC3 confers protection against neurotoxicity and neuronal injury. Here, we hypothesized that inhibition of HDAC3 may contribute to the neuronal survival elicited by PC. To address this notion, PC and transient middle cerebral artery occlusion (MCAO) were conducted in Sprague-Dawley rats. Additionally, primary cultured cortical neurons were used to identify the modulators and effectors of HDAC3 involved in PC. We found that nuclear localization of HDAC3 was significantly reduced following PC in vivo and in vitro. Treatment with the HDAC3-specific inhibitor, RGFP966, mimicked the neuroprotective effects of PC 24 h and 7 days after MCAO, causing a reduced infarct volume and less Fluoro-Jade C staining. Improved functional outcomes were observed in the neurological score and rotarod test. We further showed that attenuated recruitment of HDAC3 to promoter regions following PC potentiates transcriptional initiation of genes including Hspa1a, Bcl2l1, and Prdx2, which may underlie the mechanism of protection. In addition, PC-activated calpains were implicated in the cleavage of HDAC3. Pretreatment with calpeptin blockaded the attenuated nuclear distribution of HDAC3 and the protective effect of PC in vivo. Collectively, these results demonstrate that the inhibition of HDAC3 preconditions the brain against ischemic insults, indicating a new approach to evoke endogenous protection against stroke. PMID:27965534

  17. Thiopental Inhibits Global Protein Synthesis by Repression of Eukaryotic Elongation Factor 2 and Protects from Hypoxic Neuronal Cell Death

    PubMed Central

    Schwer, Christian I.; Lehane, Cornelius; Guelzow, Timo; Zenker, Simone; Strosing, Karl M.; Spassov, Sashko; Erxleben, Anika; Heimrich, Bernd; Buerkle, Hartmut; Humar, Matjaz

    2013-01-01

    Ischemic and traumatic brain injury is associated with increased risk for death and disability. The inhibition of penumbral tissue damage has been recognized as a target for therapeutic intervention, because cellular injury evolves progressively upon ATP-depletion and loss of ion homeostasis. In patients, thiopental is used to treat refractory intracranial hypertension by reducing intracranial pressure and cerebral metabolic demands; however, therapeutic benefits of thiopental-treatment are controversially discussed. In the present study we identified fundamental neuroprotective molecular mechanisms mediated by thiopental. Here we show that thiopental inhibits global protein synthesis, which preserves the intracellular energy metabolite content in oxygen-deprived human neuronal SK-N-SH cells or primary mouse cortical neurons and thus ameliorates hypoxic cell damage. Sensitivity to hypoxic damage was restored by pharmacologic repression of eukaryotic elongation factor 2 kinase. Translational inhibition was mediated by calcium influx, activation of the AMP-activated protein kinase, and inhibitory phosphorylation of eukaryotic elongation factor 2. Our results explain the reduction of cerebral metabolic demands during thiopental treatment. Cycloheximide also protected neurons from hypoxic cell death, indicating that translational inhibitors may generally reduce secondary brain injury. In conclusion our study demonstrates that therapeutic inhibition of global protein synthesis protects neurons from hypoxic damage by preserving energy balance in oxygen-deprived cells. Molecular evidence for thiopental-mediated neuroprotection favours a positive clinical evaluation of barbiturate treatment. The chemical structure of thiopental could represent a pharmacologically relevant scaffold for the development of new organ-protective compounds to ameliorate tissue damage when oxygen availability is limited. PMID:24167567

  18. Acetylcholine Protects against Candida albicans Infection by Inhibiting Biofilm Formation and Promoting Hemocyte Function in a Galleria mellonella Infection Model

    PubMed Central

    Rajendran, Ranjith; Borghi, Elisa; Falleni, Monica; Perdoni, Federica; Tosi, Delfina; Lappin, David F.; O'Donnell, Lindsay; Greetham, Darren; Ramage, Gordon

    2015-01-01

    Both neuronal acetylcholine and nonneuronal acetylcholine have been demonstrated to modulate inflammatory responses. Studies investigating the role of acetylcholine in the pathogenesis of bacterial infections have revealed contradictory findings with regard to disease outcome. At present, the role of acetylcholine in the pathogenesis of fungal infections is unknown. Therefore, the aim of this study was to determine whether acetylcholine plays a role in fungal biofilm formation and the pathogenesis of Candida albicans infection. The effect of acetylcholine on C. albicans biofilm formation and metabolism in vitro was assessed using a crystal violet assay and phenotypic microarray analysis. Its effect on the outcome of a C. albicans infection, fungal burden, and biofilm formation were investigated in vivo using a Galleria mellonella infection model. In addition, its effect on modulation of host immunity to C. albicans infection was also determined in vivo using hemocyte counts, cytospin analysis, larval histology, lysozyme assays, hemolytic assays, and real-time PCR. Acetylcholine was shown to have the ability to inhibit C. albicans biofilm formation in vitro and in vivo. In addition, acetylcholine protected G. mellonella larvae from C. albicans infection mortality. The in vivo protection occurred through acetylcholine enhancing the function of hemocytes while at the same time inhibiting C. albicans biofilm formation. Furthermore, acetylcholine also inhibited inflammation-induced damage to internal organs. This is the first demonstration of a role for acetylcholine in protection against fungal infections, in addition to being the first report that this molecule can inhibit C. albicans biofilm formation. Therefore, acetylcholine has the capacity to modulate complex host-fungal interactions and plays a role in dictating the pathogenesis of fungal infections. PMID:26092919

  19. Edaravone protected human brain microvascular endothelial cells from methylglyoxal-induced injury by inhibiting AGEs/RAGE/oxidative stress.

    PubMed

    Li, Wenlu; Xu, Hongjiao; Hu, Yangmin; He, Ping; Ni, Zhenzhen; Xu, Huimin; Zhang, Zhongmiao; Dai, Haibin

    2013-01-01

    Subjects with diabetes experience an increased risk of cerebrovascular disease and stroke compared with nondiabetic age-matched individuals. Increased formation of reactive physiological dicarbonyl compound methylglyoxal (MGO) seems to be implicated in the development of diabetic vascular complication due to its protein glycation and oxidative stress effect. Edaravone, a novel radical scavenger, has been reported to display the advantageous effects on ischemic stroke both in animals and clinical trials; however, little is known about whether edaravone has protective effects on diabetic cerebrovascular injury. Using cultured human brain microvascular endothelial cells (HBMEC), protective effects of edaravone on MGO and MGO enhancing oxygen-glucose deprivation (OGD) induced injury were investigated. Cell injury was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) formation, cell account, lactate dehydrogenase (LDH) release and Rhodamine 123 staining. Advanced glycation end-products (AGEs) formation and receptor for advanced glycation end-products (RAGE) expression were measured by western blotting. Cellular oxidative stress was measured by reactive oxygen species (ROS) release. Treatment of MGO for 24 h significantly induced HBMEC injury, which was inhibited by pretreatment of edaravone from 10-100 µmol/l. What's more, treatment of MGO enhanced AGEs accumulation, RAGE expression and ROS release in the cultured HBMEC, which were inhibited by 100 µmol/l edaravone. Finally, treatment of MGO for 24 h and then followed by 3 h OGD insult significantly enhanced cell injury when compared with OGD insult only, which was also protected by 100 µmol/l edaravone. Thus, edaravone protected HBMEC from MGO and MGO enhancing OGD-induced injury by inhibiting AGEs/RAGE/oxidative stress.

  20. Schisandrol B protects against acetaminophen-induced hepatotoxicity by inhibition of CYP-mediated bioactivation and regulation of liver regeneration.

    PubMed

    Jiang, Yiming; Fan, Xiaomei; Wang, Ying; Chen, Pan; Zeng, Hang; Tan, Huasen; Gonzalez, Frank J; Huang, Min; Bi, Huichang

    2015-01-01

    Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. Schisandra sphenanthera is a traditional hepato-protective Chinese medicine and Schisandrol B (SolB) is one of its major active constituents. In this study, the protective effect of SolB against APAP-induced acute hepatotoxicity in mice and the involved mechanisms were investigated. Morphological and biochemical assessments clearly demonstrated a protective effect of SolB against APAP-induced liver injury. SolB pretreatment significantly attenuated the increases in alanine aminotransferase and aspartate aminotransferase activity, and prevented elevated hepatic malondialdehyde formation and the depletion of mitochondrial glutathione (GSH) in a dose-dependent manner. SolB also dramatically altered APAP metabolic activation by inhibiting the activities of CYP2E1 and CYP3A11, which was evidenced by significant inhibition of the formation of the oxidized APAP metabolite NAPQI-GSH. A molecular docking model also predicted that SolB had potential to interact with the CYP2E1 and CYP3A4 active sites. In addition, SolB abrogated APAP-induced activation of p53 and p21, and increased expression of liver regeneration and antiapoptotic-related proteins such as cyclin D1 (CCND1), PCNA, and BCL-2. This study demonstrated that SolB exhibited a significant protective effect toward APAP-induced liver injury, potentially through inhibition of CYP-mediated APAP bioactivation and regulation of the p53, p21, CCND1, PCNA, and BCL-2 to promote liver regeneration.

  1. Schisandrol B Protects Against Acetaminophen-Induced Hepatotoxicity by Inhibition of CYP-Mediated Bioactivation and Regulation of Liver Regeneration

    PubMed Central

    Jiang, Yiming; Fan, Xiaomei; Wang, Ying; Chen, Pan; Zeng, Hang; Tan, Huasen; Gonzalez, Frank J.; Bi, Huichang

    2015-01-01

    Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. Schisandra sphenanthera is a traditional hepato-protective Chinese medicine and Schisandrol B (SolB) is one of its major active constituents. In this study, the protective effect of SolB against APAP-induced acute hepatotoxicity in mice and the involved mechanisms were investigated. Morphological and biochemical assessments clearly demonstrated a protective effect of SolB against APAP-induced liver injury. SolB pretreatment significantly attenuated the increases in alanine aminotransferase and aspartate aminotransferase activity, and prevented elevated hepatic malondialdehyde formation and the depletion of mitochondrial glutathione (GSH) in a dose-dependent manner. SolB also dramatically altered APAP metabolic activation by inhibiting the activities of CYP2E1 and CYP3A11, which was evidenced by significant inhibition of the formation of the oxidized APAP metabolite NAPQI–GSH. A molecular docking model also predicted that SolB had potential to interact with the CYP2E1 and CYP3A4 active sites. In addition, SolB abrogated APAP-induced activation of p53 and p21, and increased expression of liver regeneration and antiapoptotic-related proteins such as cyclin D1 (CCND1), PCNA, and BCL-2. This study demonstrated that SolB exhibited a significant protective effect toward APAP-induced liver injury, potentially through inhibition of CYP-mediated APAP bioactivation and regulation of the p53, p21, CCND1, PCNA, and BCL-2 to promote liver regeneration. PMID:25319358

  2. Inhibition protects acquired song segments during vocal learning in zebra finches

    PubMed Central

    Vallentin, Daniela; Kosche, Georg; Lipkind, Dina; Long, Michael A.

    2016-01-01

    Vocal imitation involves incorporating instructive auditory information into relevant motor circuits through processes that are poorly understood. In zebra finches, we find that exposure to a tutor’s song drives spiking activity within premotor neurons in the juvenile but that inhibition suppresses such responses upon learning in adulthood. We measure inhibitory currents evoked by the tutor song throughout development while simultaneously quantifying each bird’s learning trajectory. Surprisingly, we find that the maturation of synaptic inhibition onto premotor neurons is correlated with learning but not age. We used synthetic tutoring to demonstrate that inhibition is selective for specific song elements that have already been learned and not those still in refinement. Our results suggest that structured inhibition is playing a crucial role during song acquisition, enabling a piece-by-piece mastery of complex tasks. PMID:26816377

  3. Protective effect of silymarin against rapamycin-induced apoptosis and proliferation inhibition in endothelial progenitor cells.

    PubMed

    Zhang, Peng; Han, Guohua; Gao, Pei; Qiao, Kun; Ren, Yusheng; Liang, Chun; Leng, Bing; Wu, Zonggui

    2015-02-01

    For this study, peripheral blood samples were collected from human volunteers. Mononuclear cells (MNC) were separated by density centrifugation and were induced to differentiate into endothelial progenitor cells (EPCs) in vitro. Different concentrations of rapamycin and silymarin were introduced to the EPCs over 24 hours and then EPCs were analyzed for proliferation, migration, apoptosis and angiogenesis. Compared with the control group, rapamycin (1, 10, 100 ng/mL) inhibited the proliferation and migration of EPCs in a concentration dependent manner (P<0.05). Silymarin (50, 100 μg/mL) enhanced the proliferation and migration of EPCs and inhibited apoptosis in a concentration dependent manner (P<0.05). By adding rapamycin (1 ng/mL) and silymarin (25, 50, 100 μg/mL) over 24 hours, silymarin inhibited the pro-apoptotic effect of rapamycin on EPCs, and reversed the inhibition of proliferation, migration and angiogenesis of EPCs by rapamycin (P<0.05).

  4. Andrographolide protects liver cells from H2O2 induced cell death by upregulation of Nrf-2/HO-1 mediated via adenosine A2a receptor signalling.

    PubMed

    Mittal, Smriti P K; Khole, Swati; Jagadish, Nidhi; Ghosh, Debjani; Gadgil, Vijay; Sinkar, Vilas; Ghaskadbi, Saroj S

    2016-11-01

    Andrographolide, principle constituent of Andrographis paniculata Nees is used in traditional medicine in Southeast Asia and is known to exhibit various biological activities. Its antioxidant activity is due to its ability to activate one of the antioxidant enzymes, heme oxygenase-1 (HO-1) which is regulated transcriptionally through Nrf-2. However, molecular mechanism underlying activation of Nrf-2/HO-1 has not yet been clearly understood. Protective effect of andrographolide against H2O2 induced cell death, reactive oxygen species and lipid peroxidation was observed in HepG2 cells. Ability of andrographolide to modulate G-protein coupled receptor (GPCR) mediated signalling was determined using in silico docking and gene expression was analyzed by qRT-PCR, confocal microscopy and western blot analysis. We clearly show that andrographolide via adenosine A2A receptor signalling leads to activation of p38 MAP kinase, resulting in upregulation of Nrf-2, its translocation to nucleus and activation of HO-1. Additionally, it activates adenylate cyclase resulting in cAMP formation which in turn activates protein kinase A leading to inhibition of GSK-3β by phosphorylation. Inactivated GSK-3β leads to retention of Nrf-2 in the nucleus leading to sustained expression of HO-1 by binding to its antioxidant response element (ARE). Thus, andrographolide probably by binding to adenosine A2a receptor activates Nrf-2 transcription and also inhibits its exclusion from the nucleus by inactivating GSK-3β, together resulting in activation of HO-1. We speculate that andrographolide can be used as a therapeutic drug to combat oxidative stress implicated in pathogenesis of various diseases such as diabetes, osteoporosis, neurodegenerative diseases etc. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Activation of Nrf2/ARE pathway protects endothelial cells from oxidant injury and inhibits inflammatory gene expression.

    PubMed

    Chen, Xi-Lin; Dodd, Geraldine; Thomas, Suzanne; Zhang, Xiaolan; Wasserman, Martin A; Rovin, Brad H; Kunsch, Charles

    2006-05-01

    The antioxidant response element (ARE) is a transcriptional control element that mediates expression of a set of antioxidant proteins. NF-E2-related factor 2 (Nrf2) is a transcription factor that activates ARE-containing genes. In endothelial cells, the ARE-mediated genes are upregulated by atheroprotective laminar flow through a Nrf2-dependent mechanism. We tested the hypothesis that activation of ARE-regulated genes via adenovirus-mediated expression of Nrf2 may suppress redox-sensitive inflammatory gene expression. Expression of Nrf2 in human aortic endothelial cells (HAECs) resulted in a marked increase in ARE-driven transcriptional activity and protected HAECs from H2O2-mediated cytotoxicity. Nrf2 suppressed TNF-alpha-induced monocyte chemoattractant protein (MCP)-1 and VCAM-1 mRNA and protein expression in a dose-dependent manner and inhibited TNF-alpha-induced monocytic U937 cell adhesion to HAECs. Nrf2 also inhibited IL-1beta-induced MCP-1 gene expression in human mesangial cells. Expression of Nrf2 inhibited TNF-alpha-induced activation of p38 MAP kinase. Furthermore, expression of a constitutively active form of MKK6 (an upstream kinase for p38 MAP kinase) partially reversed Nrf2-mediated inhibition of VCAM-1 expression, suggesting that p38 MAP kinase, at least in part, mediates Nrf2's anti-inflammatory action. In contrast, Nrf2 did not inhibit TNF-alpha-induced NF-kappaB activation. These data identify the Nrf2/ARE pathway as an endogenous atheroprotective system for antioxidant protection and suppression of redox-sensitive inflammatory genes, suggesting that targeting the Nrf2/ARE pathway may represent a novel therapeutic approach for the treatment of inflammatory diseases such as atherosclerosis.

  6. Quantification of indirect pathway inhibition by the adenosine A2a antagonist SYN115 in Parkinson disease

    PubMed Central

    Black, Kevin J.; Koller, Jonathan M.; Campbell, Meghan C.; Gusnard, Debra A.; Bandak, Stephen I.

    2010-01-01

    Adenosine A2a receptor antagonists reduce symptom severity in Parkinson disease (PD) and animal models. Rodent studies support the hypothesis that A2a antagonists produce this benefit by reducing the inhibitory output of the basal ganglia indirect pathway. One way to test this hypothesis in humans is to quantify regional pharmacodynamic responses with cerebral blood flow (CBF) imaging. That approach has also been proposed as a tool to accelerate pharmaceutical dose-finding, but has not yet been applied in humans to drugs in development. We successfully addressed both these aims with a perfusion MRI study of the novel adenosine A2a antagonist SYN115. During a randomized, double-blind, placebo-controlled, crossover study in 21 PD patients on levodopa but no agonists, we acquired pulsed arterial spin labeling MRI at the end of each treatment period. SYN115 produced a highly significant decrease in thalamic CBF, consistent with reduced pallidothalamic inhibition via the indirect pathway. Similar decreases occurred in cortical regions whose activity decreases with increased alertness and externally-focused attention, consistent with decreased self-reported sleepiness on SYN115. Remarkably, we also derived quantitative pharmacodynamic parameters from the CBF responses to SYN115. These results suggested that the doses tested were on the low end of the effective dose range, consistent with clinical data reported separately. We conclude that (1) SYN115 enters the brain and exerts dose-dependent regional effects, (2) the most prominent of these effects is consistent with deactivation of the indirect pathway as predicted by preclinical studies; and (3) perfusion MRI can provide rapid, quantitative, clinically relevant dose-finding information for pharmaceutical development. PMID:21123574

  7. Attenuation of cysteamine-induced duodenal ulcer with Cochinchina momordica seed extract through inhibiting cytoplasmic phospholipase A2/5-lipoxygenase and activating γ-glutamylcysteine synthetase.

    PubMed

    Choi, Ki-Seok; Kim, Eun-Hee; Hong, Hua; Ock, Chan Young; Lee, Jeong Sang; Kim, Joo-Hyun; Hahm, Ki-Baik

    2012-04-01

    Cysteamine is a reducing aminothiol used for inducing duodenal ulcer through mechanisms of oxidative stress related to thiol-derived H(2)O(2) reaction. Cochinchina momordica saponins have been suggested to be protective against various gastric diseases based on their cytoprotective and anti-inflammatory mechanisms. This study was aimed to document the preventive effects of Cochinchina momordica seed extract against cysteamine-induced duodenal ulcer as well as the elucidation of its pharmacological mechanisms. Cochinchina momordica seed extract (50, 100, 200 mg/kg) was administrated intragastrically before cysteamine administration, after which the incidence of the duodenal ulcer, ulcer size, serum gastrin level, and the ratio of reduced glutathione (GSH)/oxidized glutathione disulfide (GSSG) as well as biochemical and molecular measurements of cytoplasmic phospholipase A(2) (cPLA(2)), cyclooxygenase-2 (COX-2), 5-lipoxygenase and the expression of proinflammatory genes including IL-1β, IL-6, COX-2 were measured in rat model. Additional experiments of electron spin resonance measurement and the changes of glutathione were performed. Cochinchina momordica seed extract effectively prevented cysteamine-induced duodenal ulcer in a dose-dependent manner as reflected with significant decreases in either duodenal ulcerogenesis or perforation accompanied with significantly decreased in serum gastrin in addition to inflammatory mediators including cPLA(2), COX-2, and 5-lipoxygenase. Cochinchina momordica seed extract induced the expression of γ-glutamylcysteine synthetase (γ-GCS)-related glutathione synthesis as well as significantly reduced the expression of cPLA(2). Cochinchina momordica seed extract preserved reduced glutathione through increased expressions of γ-GCS. Cochinchina momordica seed extracts exerted significantly protective effect against cysteamine-induced duodenal ulcer by either cPLA2 inhibition or glutathione preservation. © 2012 Journal of

  8. Phospholipase A2 inhibits cisplatin-induced acute kidney injury by modulating regulatory T cells by the CD206 mannose receptor.

    PubMed

    Kim, Hyunseong; Lee, Hyojung; Lee, Gihyun; Jang, Hyunil; Kim, Sung-Su; Yoon, Heera; Kang, Geun-Hyung; Hwang, Deok-Sang; Kim, Sun Kwang; Chung, Hwan-Suck; Bae, Hyunsu

    2015-09-01

    Previously, we found that Foxp3-expressing CD4(+) regulatory T (Treg) cells attenuate cisplatin-induced acute kidney injury in mice and that bee venom and its constituent phospholipase A2 (PLA2) are capable of modulating Treg cells. Here we tested whether PLA2 could inhibit cisplatin-induced acute kidney injury. As a result of treatment with PLA2, the population of Treg cells was significantly increased, both in vivo and in vitro. PLA2-injected mice showed reduced levels of serum creatinine, blood urea nitrogen, renal tissue damage, and pro-inflammatory cytokine production upon cisplatin administration. These renoprotective effects were abolished by depletion of Treg cells. Furthermore, PLA2 bound to CD206 mannose receptors on dendritic cells, essential for the PLA2-mediated protective effects on renal dysfunction. Interestingly, PLA2 treatment increased the secretion of IL-10 in the kidney from normal mice. Foxp3(+)IL-10(+) cells and CD11c(+)IL-10(+) cells were increased by PLA2 treatment. The anticancer effects of repeated administrations of a low dose of cisplatin were not affected by PLA2 treatment in a tumor-bearing model. Thus, PLA2 may prevent inflammatory responses in cisplatin-induced acute kidney injury by modulating Treg cells and IL-10 through the CD206 mannose receptor.

  9. Inhibition of de novo ceramide biosynthesis by FTY720 protects rat retina from light-induced degeneration[S

    PubMed Central

    Chen, Hui; Tran, Julie-Thu A.; Eckerd, Annette; Huynh, Tuan-Phat; Elliott, Michael H.; Brush, Richard S.; Mandal, Nawajes A.

    2013-01-01

    Light-induced retinal degeneration (LIRD) in albino rats causes apoptotic photoreceptor cell death. Ceramide is a second messenger for apoptosis. We tested whether increases in ceramide mediate photoreceptor apoptosis in LIRD and if inhibition of ceramide synthesis protects the retina. Sprague-Dawley rats were exposed to 2,700 lux white light for 6 h, and the retinal levels of ceramide and its intermediary metabolites were measured by GC-MS or electrospray ionization tandem mass spectrometry. Enzymes of the de novo biosynthetic and sphingomyelinase pathways of ceramide generation were assayed, and gene expression was measured. The dosage and temporal effect of the ceramide synthase inhibitor FTY720 on the LIRD retina were measured by histological and functional analyses. Retinal ceramide levels increased coincident with the increase of dihydroceramide at various time points after light stress. Light stress in retina induces ceramide generation predominantly through the de novo pathway, which was prevented by systemic administration of FTY720 (10 mg/kg) leading to the protection of retinal structure and function. The neuroprotection of FTY720 was independent of its immunosuppressive action. We conclude that ceramide increase by de novo biosynthesis mediates photoreceptor apoptosis in the LIRD model and that inhibition of ceramide production protects the retina against light stress. PMID:23468130

  10. Protective efficacy of phosphodiesterase-1 inhibition against alpha-synuclein toxicity revealed by compound screening in LUHMES cells.

    PubMed

    Höllerhage, Matthias; Moebius, Claudia; Melms, Johannes; Chiu, Wei-Hua; Goebel, Joachim N; Chakroun, Tasnim; Koeglsperger, Thomas; Oertel, Wolfgang H; Rösler, Thomas W; Bickle, Marc; Höglinger, Günter U

    2017-09-13

    α-synuclein-induced neurotoxicity is a core pathogenic event in neurodegenerative synucleinopathies such as Parkinson's disease, dementia with Lewy bodies, or multiple system atrophy. There is currently no disease-modifying therapy available for these diseases. We screened 1,600 FDA-approved drugs for their efficacy to protect LUHMES cells from degeneration induced by wild-type α-synuclein and identified dipyridamole, a non-selective phosphodiesterase inhibitor, as top hit. Systematic analysis of other phosphodiesterase inhibitors identified a specific phosphodiesterase 1 inhibitor as most potent to rescue from α-synuclein toxicity. Protection was mediated by an increase of cGMP and associated with the reduction of a specific α-synuclein oligomeric species. RNA interference experiments confirmed PDE1A and to a smaller extent PDE1C as molecular targets accounting for the protective efficacy. PDE1 inhibition also rescued dopaminergic neurons from wild-type α-synuclein induced degeneration in the substantia nigra of mice. In conclusion, this work identifies inhibition of PDE1A in particular as promising target for neuroprotective treatment of synucleinopathies.

  11. Inhibition of miR-23 protects myocardial function from ischemia-reperfusion injury through restoration of glutamine metabolism.

    PubMed

    Kou, Y; Zheng, W-T; Zhang, Y-R

    2016-10-01

    Myocardial disorders caused by ischemia/reperfusion (IR) continue to be among the most frequent causes of debilitating disease and death. The contribution of cellular metabolism through the production of metabolic intermediates during IR has been increasingly investigated. In this study, by using a rat IR injury model, we reported that the expression of microRNA miR-23 was induced by IR. In contrast, the glutamine metabolism was suppressed during IR. The glutamate, glutamine dehydrogenase activity, α-ketoglutarate, and glutaminase (GLS) mRNA expression were significantly decreased by IR. Moreover, the pretreatment of glutamine could protect the myocardium from IR injury. From microRNA target prediction analysis and results of luciferase assay, we found that miR-23 could directly target the 3'UTR of GLS. Finally, we demonstrated that inhibition of miR-23 protected myocardial function from IR through the restoration of glutamine metabolism. This study reveals that inhibition of miR-23 renders protective effects on rat IR injury, highlighting the importance of miR-23 and glutamine metabolism during IR, and suggests a potentially clinical benefit.

  12. Myofiber-specific inhibition of TGFβ signaling protects skeletal muscle from injury and dystrophic disease in mice.

    PubMed

    Accornero, Federica; Kanisicak, Onur; Tjondrokoesoemo, Andoria; Attia, Aria C; McNally, Elizabeth M; Molkentin, Jeffery D

    2014-12-20

    Muscular dystrophy (MD) is a disease characterized by skeletal muscle necrosis and the progressive accumulation of fibrotic tissue. While transforming growth factor (TGF)-β has emerged as central effector of MD and fibrotic disease, the cell types in diseased muscle that underlie TGFβ-dependent pathology have not been segregated. Here, we generated transgenic mice with myofiber-specific inhibition of TGFβ signaling owing to expression of a TGFβ type II receptor dominant-negative (dnTGFβRII) truncation mutant. Expression of dnTGFβRII in myofibers mitigated the dystrophic phenotype observed in δ-sarcoglycan-null (Sgcd(-/-)) mice through a mechanism involving reduced myofiber membrane fragility. The dnTGFβRII transgene also reduced muscle injury and improved muscle regeneration after cardiotoxin injury, as well as increased satellite cell numbers and activity. An unbiased global expression analysis revealed a number of potential mechanisms for dnTGFβRII-mediated protection, one of which was induction of the antioxidant protein metallothionein (Mt). Indeed, TGFβ directly inhibited Mt gene expression in vitro, the dnTGFβRII transgene conferred protection against reactive oxygen species accumulation in dystrophic muscle and treatment with Mt mimetics protected skeletal muscle upon injury in vivo and improved the membrane stability of dystrophic myofibers. Hence, our results show that the myofibers are central mediators of the deleterious effects associated with TGFβ signaling in MD.

  13. Prolyl hydroxylase 2 (PHD2) inhibition protects human renal epithelial cells and mice kidney from hypoxia injury

    PubMed Central

    Zhong, Yihong; Ding, Xiaoqiang

    2016-01-01

    Prolyl hydroxylase domain protein 2 (PHD2) is a key oxygen sensor, setting low steady-state level of hypoxia-inducible factor-α (HIF-α). Here, we showed that treatment of cobalt chloride (CoCl2), a hypoxia mimic, in HK-2 tubular epithelial cells induced PHD2 and HIF-1/2α expression as well as cell apoptosis and autophagy activation. Three methyladenine (3-MA), the autophagy inhibitor, blocked autophagy and protected HK-2 cells from CoCl2. Significantly, siRNA knockdown of PHD2 also protected HK-2 cells from CoCl2, possibly via increasing HIF-1α expression. Reversely, HIF-1α siRNA knockdown almost abolished cytoprotection by PHD2 siRNA in CoCl2-treated HK-2 cells. In vivo, pretreatment with a PHD inhibitor L-mimosine remarkably attenuated mice renal ischemia-reperfusion injuries. Molecularly, L-mimosine inhibited apoptosis and inflammatory responses in injured mice kidneys. Together, our results suggest that PHD2 silence or inhibition protects human renal epithelial cells and mice kidney from hypoxia injuries. PMID:27527871

  14. Human Antibodies Fix Complement to Inhibit Plasmodium falciparum Invasion of Erythrocytes and Are Associated with Protection against Malaria

    PubMed Central

    Boyle, Michelle J.; Reiling, Linda; Feng, Gaoqian; Langer, Christine; Osier, Faith H.; Aspeling-Jones, Harvey; Cheng, Yik Sheng; Stubbs, Janine; Tetteh, Kevin K.A.; Conway, David J.; McCarthy, James S.; Muller, Ivo; Marsh, Kevin; Anders, Robin F.; Beeson, James G.

    2015-01-01

    Summary Antibodies play major roles in immunity to malaria; however, a limited understanding of mechanisms mediating protection is a major barrier to vaccine development. We have demonstrated that acquired human anti-malarial antibodies promote complement deposition on the merozoite to mediate inhibition of erythrocyte invasion through C1q fixation and activation of the classical complement pathway. Antibody-mediated complement-dependent (Ab-C′) inhibition was the predominant invasion-inhibitory activity of human antibodies; most antibodies were non-inhibitory without complement. Inhibitory activity was mediated predominately via C1q fixation, and merozoite surface proteins 1 and 2 were identified as major targets. Complement fixation by antibodies was very strongly associated with protection from both clinical malaria and high-density parasitemia in a prospective longitudinal study of children. Ab-C′ inhibitory activity could be induced by human immunization with a candidate merozoite surface-protein vaccine. Our findings demonstrate that human anti-malarial antibodies have evolved to function by fixing complement for potent invasion-inhibitory activity and protective immunity. PMID:25786180

  15. Inhibition of ribonuclease and protease activities in arsenic exposed rice seedlings: role of proline as enzyme protectant.

    PubMed

    Mishra, Shruti; Dubey, Rama Shanker

    2006-09-01

    When seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 and Pant-12 were raised under 25 and 50 microM As2O3 in the medium an increase in the level of RNA, proteins and proline accompanied with a decline in the level of free amino acid pool was observed under arsenic supplementation compared to controls. In situ As3+ treatment caused a marked inhibition in activities of ribonuclease (RNase, EC 3.1.27.1), protease and leucine aminopeptidase (LAP, EC 3.4.11.1) whereas the activity level of carboxypeptidase (EC 3.4.16.5) was enhanced. In vitro supply of As2O3 in the enzyme assay medium beyond 400 microM resulted in gradual inhibition of RNase and beyond 5 microM inhibition of LAP activities. Addition of 1M proline in the assay medium significantly restored the loss in RNase activity due to in vitro arsenic treatment or due to osmotic stress created by incorporation of polyethylene glycol (PEG). Isoform pattern of RNase extracted from As3+ -exposed seedlings showed a significant alteration compared to its pattern in unexposed seedlings. Results suggest that arsenic exposure impairs hydrolysis of RNA and proteins in rice seedlings due to inhibition of RNase and proteases activities and that proline accumulating under As3+ toxicity appears to serve as enzyme protectant.

  16. Sophocarpine Protects Mice from ConA-Induced Hepatitis via Inhibition of the IFN-Gamma/STAT1 Pathway

    PubMed Central

    Sang, Xiu-Xiu; Wang, Rui-Lin; Zhang, Cong-En; Liu, Shi-Jing; Shen, Hong-Hui; Guo, Yu-Ming; Zhang, Ya-Ming; Niu, Ming; Wang, Jia-Bo; Bai, Zhao-Fang; Xiao, Xiao-He

    2017-01-01

    Sophocarpine is the major pharmacologically active compound of the traditional Chinese herbal medicine Radix Sophorae Subprostratae which has been used in treating hepatitis for years in China. It has been demonstrated that Sophocarpine exerts an activity in immune modulation and significantly decreases the production of inflammatory cytokines. However, the protective effects of Sophocarpine in T cell-dependent immune hepatitis remained unknown. The aim of this study was to determine the protective effects and pharmacological mechanisms of Sophocarpine on Concanavalin A (ConA)-induced hepatitis, an experimental model of T cell-mediated liver injury. BALB/C mice were pretreated with Sophocarpine or Bicyclol for five consecutive days. Thirty minutes after the final administration, the mice were injected with 15 mg⋅kg-1 of ConA intravenously. The results indicated that pretreatment with Sophocarpine significantly ameliorated liver inflammation and injury as evidenced by both biochemical and histopathological observations. Moreover, in Sophocarpine-pretreated mice, liver messenger RNA expression levels of chemokines and adhesion molecules, such as macrophage inflammatory protein-1α, CXC chemokine ligand 10, and Intercellular adhesion molecule-1, were markedly reduced. Further studies revealed that Sophocarpine significantly downregulated the expression of T-bet via inhibition of signal transducers and activators of transcription1 (STAT1) activation and overexpression of suppressor of cytokine signaling1, inhibiting the activation of Th1 cells and the expression of Interferon-γ (IFN-γ). Altogether, these results suggest new opportunities to use Sophocarpine in the treatment of T cell-mediated liver disease. In summary, Sophocarpine could attenuate ConA-induced liver injury, and the protective effect of Sophocarpine was associated with its inhibition effect of pro-inflammatory cytokines, chemokines, and the IFN-γ/STAT1 signaling pathway. PMID:28377718

  17. Petroselinum crispum has antioxidant properties, protects against DNA damage and inhibits proliferation and migration of cancer cells.

    PubMed

    Tang, Esther Lai-Har; Rajarajeswaran, Jayakumar; Fung, ShinYee; Kanthimathi, M S

    2015-10-01

    Petroselinum crispum (English parsley) is a common herb of the Apiaceae family that is cultivated throughout the world and is widely used as a seasoning condiment. Studies have shown its potential as a medicinal herb. In this study, P. crispum leaf and stem extracts were evaluated for their antioxidant properties, protection against DNA damage in normal 3T3-L1 cells, and the inhibition of proliferation and migration of the MCF-7 cells. The dichloromethane extract of P. crispum exhibited the highest phenolic content (42.31 ± 0.50 mg GAE g(-1) ) and ferric reducing ability (0.360 ± 0.009 mmol g(-1) ) of the various extractions performed. The extract showed DPPH radical scavenging activity with an IC50 value of 3310.0 ± 80.5 µg mL(-1) . Mouse fibroblasts (3T3-L1) pre-treated with 400 µg mL(-1) of the extract showed 50.9% protection against H2 O2 -induced DNA damage, suggesting its potential in cancer prevention. The extract (300 µg mL(-1) ) inhibited H2 O2 -induced MCF-7 cell migration by 41% ± 4%. As cell migration is necessary for metastasis of cancer cells, inhibition of migration is an indication of protection against metastasis. Petroselinum crispum has health-promoting properties with the potential to prevent oxidative stress-related diseases and can be developed into functional food. © 2015 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  18. Sophocarpine Protects Mice from ConA-Induced Hepatitis via Inhibition of the IFN-Gamma/STAT1 Pathway.

    PubMed

    Sang, Xiu-Xiu; Wang, Rui-Lin; Zhang, Cong-En; Liu, Shi-Jing; Shen, Hong-Hui; Guo, Yu-Ming; Zhang, Ya-Ming; Niu, Ming; Wang, Jia-Bo; Bai, Zhao-Fang; Xiao, Xiao-He

    2017-01-01

    Sophocarpine is the major pharmacologically active compound of the traditional Chinese herbal medicine Radix Sophorae Subprostratae which has been used in treating hepatitis for years in China. It has been demonstrated that Sophocarpine exerts an activity in immune modulation and significantly decreases the production of inflammatory cytokines. However, the protective effects of Sophocarpine in T cell-dependent immune hepatitis remained unknown. The aim of this study was to determine the protective effects and pharmacological mechanisms of Sophocarpine on Concanavalin A (ConA)-induced hepatitis, an experimental model of T cell-mediated liver injury. BALB/C mice were pretreated with Sophocarpine or Bicyclol for five consecutive days. Thirty minutes after the final administration, the mice were injected with 15 mg⋅kg(-1) of ConA intravenously. The results indicated that pretreatment with Sophocarpine significantly ameliorated liver inflammation and injury as evidenced by both biochemical and histopathological observations. Moreover, in Sophocarpine-pretreated mice, liver messenger RNA expression levels of chemokines and adhesion molecules, such as macrophage inflammatory protein-1α, CXC chemokine ligand 10, and Intercellular adhesion molecule-1, were markedly reduced. Further studies revealed that Sophocarpine significantly downregulated the expression of T-bet via inhibition of signal transducers and activators of transcription1 (STAT1) activation and overexpression of suppressor of cytokine signaling1, inhibiting the activation of Th1 cells and the expression of Interferon-γ (IFN-γ). Altogether, these results suggest new opportunities to use Sophocarpine in the treatment of T cell-mediated liver disease. In summary, Sophocarpine could attenuate ConA-induced liver injury, and the protective effect of Sophocarpine was associated with its inhibition effect of pro-inflammatory cytokines, chemokines, and the IFN-γ/STAT1 signaling pathway.

  19. Tacrolimus Protects Podocytes from Injury in Lupus Nephritis Partly by Stabilizing the Cytoskeleton and Inhibiting Podocyte Apoptosis.

    PubMed

    Liao, Ruyi; Liu, Qinghua; Zheng, Zhihua; Fan, Jinjin; Peng, Wenxing; Kong, Qingyu; He, Huijuan; Yang, Shicong; Chen, Wenfang; Tang, Xueqing; Yu, Xueqing

    2015-01-01

    Several studies have reported that tacrolimus (TAC) significantly reduced proteinuria in lupus nephritis (LN) patients and mouse models. However, the mechanism for this effect remains undetermined. This study explored the mechanism of how TAC protects podocytes from injury to identify new targets for protecting renal function. MRL/lpr mice were given TAC at a dosage of 0.1 mg/kg per day by intragastric administration for 8 weeks. Urine and blood samples were collected. Kidney sections (2 μm) were stained with hematoxylin-eosin (HE), periodic acid-Schiff base (PAS) and Masson's trichrome stain. Mouse podocyte cells (MPC5) were treated with TAC and/or TGF-β1 for 48 h. The mRNA levels and protein expression of synaptopodin and Wilms' tumor 1 (WT1) were determined by real-time PCR, Western blotting and/or immunofluorescence, respectively. Flow cytometry was used to detect cell apoptosis with annexin V. Podocyte foot processes were observed under transmission electron microscopy. IgG and C3 deposition were assessed with immunofluorescence assays and confocal microscopy. Synaptopodin expression significantly decreased in MRL/lpr disease control mice, accompanied by increases in 24-h proteinuria, blood urea nitrogen, and serum creatinine. TAC, however, reduced proteinuria, improved renal function, attenuated renal pathology, restored synaptopodin expression and preserved podocyte numbers. In MPC5 cells, TGF-β1 enhanced F-actin damage in podocytes and TAC stabilized it. TAC also decreased TGF-β1-induced podocyte apoptosis in vitro and inhibited foot process fusion in MRL/lpr mice. In addition, our results also showed TAC inhibited glomerular deposition of IgG and C3. This study demonstrated that TAC reduced proteinuria and preserved renal function in LN through protecting podocytes from injury partly by stabilizing podocyte actin cytoskeleton and inhibiting podocyte apoptosis.

  20. Electric power plants: protective coatings and corrosion inhibition. January, 1970-September, 1981 (citations from the Engineering Index data base). Report for Jan 70-Sep 81

    SciTech Connect

    Not Available

    1981-09-01

    Protective coatings for power plants are discussed. Corrosion protection by means of applied coatings or the use of electrochemical inhibition is featured. Particular emphasis is placed on heat transfer problems associated with the formation of boiler scale on heat exchanger surfaces. Boiler water treatment for the inhibition of corrosion and the formation of deposits are also included, as is the removal of sulfur compounds to reduce high temperature sulfidation corrosion. (Contains 134 citations fully indexed and including a title list.)

  1. DNA-AuNP networks on cell membranes as a protective barrier to inhibit viral attachment, entry and budding.

    PubMed

    Li, Chun Mei; Zheng, Lin Ling; Yang, Xiao Xi; Wan, Xiao Yan; Wu, Wen Bi; Zhen, Shu Jun; Li, Yuan Fang; Luo, Ling Fei; Huang, Cheng Zhi

    2016-01-01

    Viral infections have caused numerous diseases and deaths worldwide. Due to the emergence of new viruses and frequent virus variation, conventional antiviral strategies that directly target viral or cellular proteins are limited because of the specificity, drug resistance and rapid clearance from the human body. Therefore, developing safe and potent antiviral agents with activity against viral infection at multiple points in the viral life cycle remains a major challenge. In this report, we propose a new modality to inhibit viral infection by fabricating DNA conjugated gold nanoparticle (DNA-AuNP) networks on cell membranes as a protective barrier. The DNA-AuNPs networks were found, via a plaque formation assay and viral titers, to have potent antiviral ability and protect host cells from human respiratory syncytial virus (RSV). Confocal immunofluorescence image analysis showed 80 ± 3.8% of viral attachment, 91.1 ± 0.9% of viral entry and 87.9 ± 2.8% of viral budding were inhibited by the DNA-AuNP networks, which were further confirmed by real-time fluorescence imaging of the RSV infection process. The antiviral activity of the networks may be attributed to steric effects, the disruption of membrane glycoproteins and limited fusion of cell membrane bilayers, all of which play important roles in viral infection. Therefore, our results suggest that the DNA-AuNP networks have not only prophylactic effects to inhibit virus attachment and entry, but also therapeutic effects to inhibit viral budding and cell-to-cell spread. More importantly, this proof-of-principle study provides a pathway for the development of a universal, broad-spectrum antiviral therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Inhibition of Annexin A2 gene transcription is a promising molecular target for hepatoma cell proliferation and metastasis

    PubMed Central

    DONG, ZHIZHEN; YAO, MIN; ZHANG, HAIJIAN; WANG, LI; HUANG, HUA; YAN, MEIJUAN; WU, WEI; YAO, DENGFU

    2014-01-01

    Hepatocyte Annexin A2 (ANXA2) expression is associated with the progression and metastasis of hepatocellular carcinoma (HCC). Circulating ANXA2 levels in HCC patients are significantly higher compared with that of patients with benign liver disease. ANXA2 levels have been found to correlate with hepatitis B virus infection, extrahepatic metastasis and portal vein thrombus. By contrast, ANXA2 levels do not correlate with tumour size and AFP levels. However, the underlying mechanisms of ANXA2 remain obscure. The results of the current study identified that abnormalities in hepatic ANXA2 expression were localised to the cell membrane and cytoplasm of HCC tissues and mainly in the cytoplasm of para-cancerous tissues. ANXA2 was overexpressed in MHCC97-H cells which have high metastatic potential. Following specific ANXA2-small hairpin RNA (shRNA) transfection in vitro, ANXA-2 was effectively inhibited and the S phase ratio of cells was 27.76%, compared with 36.14% in mock-treated cells. In addition, the invading cell ratio was reduced in the shRNA-treated group (52.16%) compared with the mock-treated group (86.14%). The growth and volume of xenograft tumours in vivo was significantly suppressed (P<0.05) in the shRNA group compared with that of the mock group, indicating that ANXA2 may be a novel and useful target for elucidating molecular mechanisms involving the proliferation and metastasis of HCC. PMID:24348815

  3. An Orally Bioavailable Antipoxvirus Compound (ST-246) Inhibits Extracellular Virus Formation and Protects Mice from Lethal Orthopoxvirus Challenge

    PubMed Central

    Yang, Guang; Pevear, Daniel C.; Davies, Marc H.; Collett, Marc S.; Bailey, Tom; Rippen, Susan; Barone, Linda; Burns, Chris; Rhodes, Gerry; Tohan, Sanjeev; Huggins, John W.; Baker, Robert O.; Buller, R. L. Mark; Touchette, Erin; Waller, Kem; Schriewer, Jill; Neyts, Johan; DeClercq, Erik; Jones, Kevin; Hruby, Dennis; Jordan, Robert

    2005-01-01

    ST-246 is a low-molecular-weight compound (molecular weight = 376), that is potent (concentration that inhibited virus replication by 50% = 0.010 μM), selective (concentration of compound that inhibited cell viability by 50% = >40 μM), and active against multiple orthopoxviruses, including vaccinia, monkeypox, camelpox, cowpox, ectromelia (mousepox), and variola viruses. Cowpox virus variants selected in cell culture for resistance to ST-246 were found to have a single amino acid change in the V061 gene. Reengineering this change back into the wild-type cowpox virus genome conferred resistance to ST-246, suggesting that V061 is the target of ST-246 antiviral activity. The cowpox virus V061 gene is homologous to vaccinia virus F13L, which encodes a major envelope protein (p37) required for production of extracellular virus. In cell culture, ST-246 inhibited plaque formation and virus-induced cytopathic effects. In single-cycle growth assays, ST-246 reduced extracellular virus formation by 10 fold relative to untreated controls, while having little effect on the production of intracellular virus. In vivo oral administration of ST-246 protected BALB/c mice from lethal infection, following intranasal inoculation with 10× 50% lethal dose (LD50) of vaccinia virus strain IHD-J. ST-246-treated mice that survived infection acquired protective immunity and were resistant to subsequent challenge with a lethal dose (10× LD50) of vaccinia virus. Orally administered ST-246 also protected A/NCr mice from lethal infection, following intranasal inoculation with 40,000× LD50 of ectromelia virus. Infectious virus titers at day 8 postinfection in liver, spleen, and lung from ST-246-treated animals were below the limits of detection (<10 PFU/ml). In contrast, mean virus titers in liver, spleen, and lung tissues from placebo-treated mice were 6.2 × 107, 5.2 × 107, and 1.8 × 105 PFU/ml, respectively. Finally, oral administration of ST-246 inhibited vaccinia virus-induced tail

  4. An orally bioavailable antipoxvirus compound (ST-246) inhibits extracellular virus formation and protects mice from lethal orthopoxvirus Challenge.

    PubMed

    Yang, Guang; Pevear, Daniel C; Davies, Marc H; Collett, Marc S; Bailey, Tom; Rippen, Susan; Barone, Linda; Burns, Chris; Rhodes, Gerry; Tohan, Sanjeev; Huggins, John W; Baker, Robert O; Buller, R L Mark; Touchette, Erin; Waller, Kem; Schriewer, Jill; Neyts, Johan; DeClercq, Erik; Jones, Kevin; Hruby, Dennis; Jordan, Robert

    2005-10-01

    ST-246 is a low-molecular-weight compound (molecular weight = 376), that is potent (concentration that inhibited virus replication by 50% = 0.010 microM), selective (concentration of compound that inhibited cell viability by 50% = >40 microM), and active against multiple orthopoxviruses, including vaccinia, monkeypox, camelpox, cowpox, ectromelia (mousepox), and variola viruses. Cowpox virus variants selected in cell culture for resistance to ST-246 were found to have a single amino acid change in the V061 gene. Reengineering this change back into the wild-type cowpox virus genome conferred resistance to ST-246, suggesting that V061 is the target of ST-246 antiviral activity. The cowpox virus V061 gene is homologous to vaccinia virus F13L, which encodes a major envelope protein (p37) required for production of extracellular virus. In cell culture, ST-246 inhibited plaque formation and virus-induced cytopathic effects. In single-cycle growth assays, ST-246 reduced extracellular virus formation by 10 fold relative to untreated controls, while having little effect on the production of intracellular virus. In vivo oral administration of ST-246 protected BALB/c mice from lethal infection, following intranasal inoculation with 10x 50% lethal dose (LD(50)) of vaccinia virus strain IHD-J. ST-246-treated mice that survived infection acquired protective immunity and were resistant to subsequent challenge with a lethal dose (10x LD(50)) of vaccinia virus. Orally administered ST-246 also protected A/NCr mice from lethal infection, following intranasal inoculation with 40,000x LD(50) of ectromelia virus. Infectious virus titers at day 8 postinfection in liver, spleen, and lung from ST-246-treated animals were below the limits of detection (<10 PFU/ml). In contrast, mean virus titers in liver, spleen, and lung tissues from placebo-treated mice were 6.2 x 10(7), 5.2 x 10(7), and 1.8 x 10(5) PFU/ml, respectively. Finally, oral administration of ST-246 inhibited vaccinia virus

  5. Acetyl-L-carnitine protects yeast cells from apoptosis and aging and inhibits mitochondrial fission.

    PubMed

    Palermo, Vanessa; Falcone, Claudio; Calvani, Menotti; Mazzoni, Cristina

    2010-08-01

    In this work we report that carnitines, in particular acetyl-l-carnitine (ALC), are able to prolong the chronological aging of yeast cells during the stationary phase. Lifespan extension is significantly reduced in yca1 mutants as well in rho(0) strains, suggesting that the protective effects pass through the Yca1 caspase and mitochondrial functions. ALC can also prevent apoptosis in pro-apoptotic mutants, pointing to the importance of mitochondrial functions in regulating yeast apoptosis and aging. We also demonstrate that ALC attenuates mitochondrial fission in aged yeast cells, indicating a correlation between its protective effect and this process. Our findings suggest that ALC, used as therapeutic for stroke, myocardial infarction and neurodegenerative diseases, besides the well-known anti-oxidant effects, might exert protective effects also acting on mitochondrial morphology.

  6. Lactobacillus zeae Protects Caenorhabditis elegans from Enterotoxigenic Escherichia coli-Caused Death by Inhibiting Enterotoxin Gene Expression of the Pathogen

    PubMed Central

    Zhou, Mengzhou; Yu, Hai; Yin, Xianhua; Sabour, Parviz M.; Chen, Wei; Gong, Joshua

    2014-01-01

    Background The nematode Caenorhabditis elegans has become increasingly used for screening antimicrobials and probiotics for pathogen control. It also provides a useful tool for studying microbe-host interactions. This study has established a C. elegans life-span assay to preselect probiotic bacteria for controlling K88+ enterotoxigenic Escherichia coli (ETEC), a pathogen causing pig diarrhea, and has determined a potential mechanism underlying the protection provided by Lactobacillus. Methodology/Principal Findings Life-span of C. elegans was used to measure the response of worms to ETEC infection and protection provided by lactic acid-producing bacteria (LAB). Among 13 LAB isolates that varied in their ability to protect C. elegans from death induced by ETEC strain JG280, Lactobacillus zeae LB1 offered the highest level of protection (86%). The treatment with Lactobacillus did not reduce ETEC JG280 colonization in the nematode intestine. Feeding E. coli strain JFF4 (K88+ but lacking enterotoxin genes of estA, estB, and elt) did not cause death of worms. There was a significant increase in gene expression of estA, estB, and elt during ETEC JG280 infection, which was remarkably inhibited by isolate LB1. The clone with either estA or estB expressed in E. coli DH5α was as effective as ETEC JG280 in killing the nematode. However, the elt clone killed only approximately 40% of worms. The killing by the clones could also be prevented by isolate LB1. The same isolate only partially inhibited the gene expression of enterotoxins in both ETEC JG280 and E. coli DH5α in-vitro. Conclusions/Significance The established life-span assay can be used for studies of probiotics to control ETEC (for effective selection and mechanistic studies). Heat-stable enterotoxins appeared to be the main factors responsible for the death of C. elegans. Inhibition of ETEC enterotoxin production, rather than interference of its intestinal colonization, appears to be the mechanism of protection

  7. Bacterial β-glucuronidase inhibition protects mice against enteropathy induced by indomethacin, ketoprofen or diclofenac: mode of action and pharmacokinetics.

    PubMed

    Saitta, Kyle S; Zhang, Carmen; Lee, Kang Kwang; Fujimoto, Kazunori; Redinbo, Matthew R; Boelsterli, Urs A

    2014-01-01

    1.  We have previously demonstrated that a small molecule inhibitor of bacterial β-glucuronidase (Inh-1; [1-((6,8-dimethyl-2-oxo-1,2-dihydroquinolin-3-yl)-3-(4-ethoxyphenyl)-1-(2-hydroxyethyl)thiourea]) protected mice against diclofenac (DCF)-induced enteropathy. Here we report that Inh-1 was equally protective against small intestinal injury induced by other carboxylic acid-containing non-steroidal anti-inflammatory drugs (NSAIDs), indomethacin (10 mg/kg, ip) and ketoprofen (100 mg/kg, ip). 2.  Inh-1 provided complete protection if given prior to DCF (60 mg/kg, ip), and partial protection if administered 3-h post-DCF, suggesting that the temporal window of mucosal protection can be extended for drugs undergoing extensive enterohepatic circulation. 3.  Pharmacokinetic analysis of Inh-1 revealed an absolute bioavailability (F) of 21% and a short t1/2 of <1 h. This low F was shown to be due to hepatic first-pass metabolism, as confirmed with the pan-CYP inhibitor, 1-aminobenzotriazole. 4.  Using the fluorescent probe 5 (and 6)-carboxy-2',7'-dichlorofluorescein, we demonstrated that Inh-1 did not interfere with hepatobiliary export of glucuronides in gall bladder-cannulated mice. 5.  These data are compatible with the hypothesis that pharmacological inhibition of bacterial β-glucuronidase-mediated cleavage of NSAID glucuronides in the small intestinal lumen can protect against NSAID-induced enteropathy caused by locally high concentrations of NSAID aglycones.

  8. Syzygium jambolanum and Cephalandra indica homeopathic preparations inhibit albumin glycation and protect erythrocytes: an in vitro study.

    PubMed

    Tupe, Rashmi Santosh; Kulkarni, Amruta; Adeshara, Krishna; Shaikh, Shamim; Shah, Nilesh; Jadhav, Arun

    2015-07-01

    Diabetes mellitus is a common endocrine disorder characterized by hyperglycemia eventually resulting in long-term complications. Increased glycation of proteins is implicated in the pathogenesis of complications. For treatment of diabetes, Syzygium jambolanum and Cephalandra indica are frequently prescribed in homeopathy. However their role in glycation is not well elucidated. The present study aimed to evaluate the role of these homeopathic preparations in glycation induced structural modifications and further to examine their cellular protection ability. In human erythrocytes, in vitro mother tincture and dilutions of S. jambolanum (Sj ф, 30c, 200c), C. indica (Ci ф, 30c, 200c) and standard antiglycator (AG) were compared and their antiglycation potential assessed by the estimating different markers of glycation (frcutosamines, carbonyls, bound sugar), structural modifications (free amino and thiol group). Phytochemical characterization (total phenolic, flavonoids and glycosides contents) was performed. The homeopathic preparations have different mode of action on albumin glycation modifications. Sj ф preparation demonstrated effective inhibition of all glycation, structural modifications except amino group protection. When dilutions were compared, Sj preparations showed reduction of glycation, structural modifications. All preparations showed significant erythrocyte protection. Sj ф preparation exhibited noteworthy antiglycation and cell protection ability as compared to AG. These homeopathic preparations especially Sj ф prevented glycation induced albumin modifications and subsequent toxicity in human eryrthrocytre in vitro. Further investigation of their potential as antiglycators is justified. Copyright © 2015 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  9. Epithelial-specific A2B adenosine receptor signaling protects the colonic epithelial barrier during acute colitis

    PubMed Central

    Aherne, CM; Saeedi, B; Collins, CB; Masterson, JC; McNamee, EN; Perrenoud, L; Rapp, CR; Curtis, VF; Bayless, A; Fletcher, A; Glover, LE; Evans, CM; Jedlicka, P; Furuta, GT; de Zoeten, EF; Colgan, SP; Eltzschig, HK

    2015-01-01

    Central to inflammatory bowel disease (IBD) pathogenesis is loss of mucosal barrier function. Emerging evidence implicates extracellular adenosine signaling in attenuating mucosal inflammation. We hypothesized that adenosine-mediated protection from intestinal barrier dysfunction involves tissue-specific signaling through the A2B adenosine receptor (Adora2b) at the intestinal mucosal surface. To address this hypothesis, we combined pharmacologic studies and studies in mice with global or tissue-specific deletion of the Adora2b receptor. Adora2b−/− mice experienced a significantly heightened severity of colitis, associated with a more acute onset of disease and loss of intestinal epithelial barrier function. Comparison of mice with Adora2b deletion on vascular endothelial cells (Adora2bfl/flVeCadCre+) or intestinal epithelia (Adora2bfl/flVillinCre+) revealed a selective role for epithelial Adora2b signaling in attenuating colonic inflammation. In vitro studies with Adora2b knockdown in intestinal epithelial cultures or pharmacologic studies highlighted Adora2b-driven phosphorylation of vasodilator-stimulated phosphoprotein (VASP) as a specific barrier repair response. Similarly, in vivo studies in genetic mouse models or treatment studies with an Adora2b agonist (BAY 60-6583) recapitulate these findings. Taken together, our results suggest that intestinal epithelial Adora2b signaling provides protection during intestinal inflammation via enhancing mucosal barrier responses. PMID:25850656

  10. Breast milk protects against the development of necrotizing enterocolitis through inhibition of Toll Like Receptor 4 in the intestinal epithelium via activation of the epidermal growth factor receptor

    PubMed Central

    Good, Misty; Sodhi, Chhinder P.; Egan, Charlotte E.; Afrazi, Amin; Jia, Hongpeng; Yamaguchi, Yukihiro; Lu, Peng; Branca, Maria F.; Ma, Congrong; Prindle, Thomas; Mielo, Samantha; Pompa, Anthony; Hodzic, Zerina; Ozolek, John A.; Hackam, David J.

    2015-01-01

    Breast milk is the most effective strategy to protect infants against necrotizing enterocolitis (NEC), a devastating disease which is characterized by severe intestinal necrosis. Previous studies have demonstrated that the lipopolysaccharide receptor toll-like receptor 4 (TLR4) plays a critical role in NEC development via deleterious effects on mucosal injury and repair. We now hypothesize that breast milk protects against NEC by inhibiting TLR4 within the intestinal epithelium, and sought to determine the mechanisms involved. Breast milk protected against NEC and reduced TLR4 signaling in wild-type neonatal mice, but not in mice lacking the epidermal growth factor receptor (EGFR), while selective removal of EGF from breast milk reduced its protective properties, indicating that breast milk inhibits NEC and attenuates TLR4 signaling via EGF/EGFR activation. Over-expression of TLR4 in the intestinal epithelium reversed the protective effects of breast milk. The protective effects of breast milk occurred via inhibition of enterocyte apoptosis and restoration of enterocyte proliferation. Importantly, in IEC-6 enterocytes, breast milk inhibited TLR4 signaling via inhibition of GSK3β. Taken together, these findings offer mechanistic insights into the protective role for breast milk in NEC, and support a link between growth factor and innate immune receptors in NEC pathogenesis. PMID:25899687

  11. Endophilin A2 protects H2O2-induced apoptosis by blockade of Bax translocation in rat basilar artery smooth muscle cells.

    PubMed

    Liu, Yun; Gao, Min; Ma, Ming-Ming; Tang, Yong-Bo; Zhou, Jia-Guo; Wang, Guan-Lei; Du, Yan-Hua; Guan, Yong-Yuan

    2016-03-01

    Apoptosis plays a central role in maintaining the normal cell number and tissue homeostasis. Endophilins are a family of evolutionarily conserved proteins that have the critical role in endocytosis. Here, we determined whether endophilin A2 (EndoII) contributes to hydrogen peroxide (H2O2)-induced apoptosis in rat basilar artery smooth muscle cells (BASMCs) and the underlying mechanisms. By using small interference RNA (siRNA) and EndoII overexpression strategy, we found that EndoII siRNA knockdown reduced cell viability and promoted H2O2-induced cell apoptosis, evidenced by loss of mitochondrial membrane potential, release of cytochrome c, and activation of caspase-9, 3 and poly (ADP-ribose) polymerase (PARP). In contrast, EndoII overexpression showed opposite effects and inhibited H2O2-induced BASMCs apoptosis. Further studies revealed that there was a direct interaction between EndoII and Bax. Upon H2O2-induced apoptosis, the association of EndoII with Bax were significantly decreased, while the interaction of Bax/tBid were increased, accompanied by a translocation of Bax from cytosol to mitochondria. Knockdown of EndoII did not affect the expression of Bax, but further promoted the binding of Bax with tBid and favored the accumulation of Bax to mitochondria as well as Bax activation; whereas EndoII overexpression produced the opposite effects. In addition, EndoII siRNA aggravated, but EndoII overexpression alleviated, the reduction of Bcl-2 expression in H2O2-treated cells. These data suggested a role of EndoII in protecting BASMCs apoptosis induced by H2O2, possibly by inhibiting the addressing of Bax to mitochondria. Targeting on EndoII may be a new strategy to treat apoptosis-associated diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Corrosion inhibition with different protective layers in tinplate cans for food preservation.

    PubMed

    Grassino, Antonela Ninčević; Grabarić, Zorana; Pezzani, Aldo; Squitieri, Giuseppe; Berković, Katarina

    2010-11-01

    In this work the influence of essential onion oil (EOO) on the protection of tinplates was compared with dioctyl sebacate oil (DOS) and epoxy phenolic lacquers, which are frequently used in the food canning industry. When EOO as the protective layer instead of DOS oil was used, tinplate porosity, measured electrochemically (7.58 ± 1.97 µA cm(-2) and 23.0 ± 1.3 µA cm(-2), respectively), and iron coating mass, calculated from AAS data (1.52 ± 0.15 mg m(-2) and 3.14 ± 0.42, respectively), was much lower indicating better corrosion protection. At higher storing temperature (36 °C) the addition of EOO to canned tomato purée enhanced the formation of hydrogen with time. The increasing volume fraction of H(2) (from 34.0 to 90.9% for cans without nitrates, and from 33.8 to 89.2% for cans with nitrates) is an indicator that corrosion takes place. As the use of EOO improves the protection of tinplate compared with DOS oil, and is almost as effective as epoxy phenolic lacquer, the addition of EOO can be recommended due to lower cost of canned food production and enhanced organoleptic properties, but the storage temperature has to be lower then 36 °C. 2010 Society of Chemical Industry

  13. Kaempferol suppresses collagen-induced platelet activation by inhibiting NADPH oxidase and protecting SHP-2 from oxidative inactivation.

    PubMed

    Wang, Su Bin; Jang, Ji Yong; Chae, Yun Hee; Min, Ji Hyun; Baek, Jin Young; Kim, Myunghee; Park, Yunjeong; Hwang, Gwi Seo; Ryu, Jae-Sang; Chang, Tong-Shin

    2015-06-01

    Reactive oxygen species (ROS) generated upon collagen stimulation act as second messengers to propagate various platelet-activating events. Among the ROS-generating enzymes, NADPH oxidase (NOX) plays a prominent role in platelet activation. Thus, NOX has been suggested as a novel target for anti-platelet drug development. Although kaempferol has been identified as a NOX inhibitor, the influence of kaempferol on the activation of platelets and the underlying mechanism have never been investigated. Here, we studied the effects of kaempferol on NOX activation, ROS-dependent signaling pathways, and functional responses in collagen-stimulated platelets. Superoxide anion generation stimulated by collagen was significantly inhibited by kaempferol in a concentration-dependent manner. More importantly, kaempferol directly bound p47(phox), a major regulatory subunit of NOX, and significantly inhibited collagen-induced phosphorylation of p47(phox) and NOX activation. In accordance with the inhibition of NOX, ROS-dependent inactivation of SH2 domain-containing protein tyrosine phosphatase-2 (SHP-2) was potently protected by kaempferol. Subsequently, the specific tyrosine phosphorylation of key components (Syk, Vav1, Btk, and PLCγ2) of collagen receptor signaling pathways was suppressed by kaempferol. Kaempferol also attenuated downstream responses, including cytosolic calcium elevation, P-selectin surface exposure, and integrin-αIIbβ3 activation. Ultimately, kaempferol inhibited platelet aggregation and adhesion in response to collagen in vitro and prolonged in vivo thrombotic response in carotid arteries of mice. This study shows that kaempferol impairs collagen-induced platelet activation through inhibition of NOX-derived ROS production and subsequent oxidative inactivation of SHP-2. This effect suggests that kaempferol has therapeutic potential for the prevention and treatment of thrombovascular diseases.

  14. Sulforaphane protects from T cell-mediated autoimmune disease by inhibition of IL-23 and IL-12 in dendritic cells.

    PubMed

    Geisel, Julia; Brück, Jürgen; Glocova, Ivana; Dengler, Katja; Sinnberg, Tobias; Rothfuss, Oliver; Walter, Michael; Schulze-Osthoff, Klaus; Röcken, Martin; Ghoreschi, Kamran

    2014-04-15

    Sulforaphane (SFN), an isothiocyanate, is part of an important group of naturally occurring small molecules with anti-inflammatory properties. The published reports are best conceivable with an inhibition of T cell function, but the mode of action remains unknown. We therefore analyzed the effect of SFN on T cell-mediated autoimmune disease. Feeding mice with SFN protected from severe experimental autoimmune encephalomyelitis. Disease amelioration was associated with reduced IL-17 and IFN-γ expression in draining lymph nodes. In vitro, SFN treatment of T cells did not directly alter T cell cytokine secretion. In contrast, SFN treatment of dendritic cells (DCs) inhibited TLR4-induced IL-12 and IL-23 production, and severely suppressed Th1 and Th17 development of T cells primed by SFN-treated DCs. SFN regulated the activity of the TLR4-induced transcription factor NF-κB, without affecting the degradation of its inhibitor IκB-α. Instead, SFN treatment of DCs resulted in strong expression of the stress response protein heme oxygenase-1 (HO-1), which interacts with and thereby inhibits NF-κB p65. Consistent with these findings, HO-1 bound to p65 and subsequently inhibited the p65 activity at the IL23a and IL12b promoters. Importantly, SFN suppressed Il23a and Il12b expression in vivo and silenced Th17/Th1 responses within the CNS. Thus, our data show that SFN improves Th17/Th1-mediated autoimmune disease by inducing HO-1 and inhibiting NF-κB p65-regulated IL-23 and IL-12 expression.

  15. Temporary protection of metals against atmospheric corrosion by saturated straight chain aliphatic monocarboxylates. Mechanisms of inhibition

    SciTech Connect

    Kapin, C.; Steinmetz, P.; Steinmetz, J.

    1998-12-31

    This work was devoted to the investigations of the ability of saturated straight chain aliphatic monocarboxylates to inhibit corrosion of mild steel and zinc in aerated aqueous solutions. Performances of inhibitors were shown to be dependent on their chain length, their concentration and the immersion duration. Both crystallographic parameters and solubilities of iron and zinc carboxylates were determined. Then potential-pH diagrams of iron and zinc in water were built taking the presence of metallic soaps into account. According to these diagrams, the passivation of metals was attributed to the growth of films containing metallic soaps. This model confirms that previously proposed for inhibition of copper and magnesium by the same carboxylates.

  16. Fenamate NSAIDs inhibit the NLRP3 inflammasome and protect against Alzheimer's disease in rodent models

    PubMed Central

    Daniels, Michael J. D.; Rivers-Auty, Jack; Schilling, Tom; Spencer, Nicholas G.; Watremez, William; Fasolino, Victoria; Booth, Sophie J.; White, Claire S.; Baldwin, Alex G.; Freeman, Sally; Wong, Raymond; Latta, Clare; Yu, Shi; Jackson, Joshua; Fischer, Nicolas; Koziel, Violette; Pillot, Thierry; Bagnall, James; Allan, Stuart M.; Paszek, Pawel; Galea, James; Harte, Michael K.; Eder, Claudia; Lawrence, Catherine B.; Brough, David

    2016-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase-1 (COX-1) and COX-2 enzymes. The NLRP3 inflammasome is a multi-protein complex responsible for the processing of the proinflammatory cytokine interleukin-1β and is implicated in many inflammatory diseases. Here we show that several clinically approved and widely used NSAIDs of the fenamate class are effective and selective inhibitors of the NLRP3 inflammasome via inhibition of the volume-regulated anion channel in macrophages, independently of COX enzymes. Flufenamic acid and mefenamic acid are efficacious in NLRP3-dependent rodent models of inflammation in air pouch and peritoneum. We also show therapeutic effects of fenamates using a model of amyloid beta induced memory loss and a transgenic mouse model of Alzheimer's disease. These data suggest that fenamate NSAIDs could be repurposed as NLRP3 inflammasome inhibitors and Alzheimer's disease therapeutics. PMID:27509875

  17. Kallistatin protects against bleomycin-induced idiopathic pulmonary fibrosis by inhibiting angiogenesis and inflammation

    PubMed Central

    Huang, Xiaoping; Wang, Xiao; Xie, Xiaolan; Zeng, Shulan; Li, Zhaofa; Xu, Xianxiang; Yang, Huiyong; Qiu, Fei; Lin, Junsheng; Diao, Yong

    2017-01-01

    Aberrant angiogenesis and vascular remodeling are the main features of idiopathic pulmonary fibrosis. Kallistatin is an anti-angiogenic peptide with known effects on endothelial cells. This study aimed to demonstrate that kallistatin has beneficial effects on bleomycin (BLM)-induced pulmonary fibrosis in a rat model by inhibiting angiogenesis. Twenty-five rats were randomly divided into five experimental groups: (A) Saline only (SA)-as the negative control, (B) BLM only (BLM)-as the model group, (C) BLM and 0.1 mg/kg kallistatin (L-Kal), (D) BLM and 0.5 mg/kg kallistatin (M-Kal), and (E) BLM and 2.5 mg/kg kallistatin (H-Kal). Fibrillar collagen was quantified by Masson’s trichrome and hematoxylin-eosin staining. Transforming growth factor-β1 (TGF-β1), α-smooth-muscle-actin (α-SMA) and microvascular density (MVD) were measured by immunohistochemistry. Vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR), and tumor necrosis factor-α (TNF-α) were assayed by Western immunoblotting or ELISA. Daily administration of kallistatin attenuated fibrosis in BLM-induced pulmonary fibrosis, as shown by histology. During inflammation from BLM-induced pulmonary fibrosis, kallistatin reduced the number of inflammatory cells infiltrating the bronchoalveolar lavage fluid. Kallistatin also inhibited VEGF expression and phosphorylation of VEGFR2 (Flk-1). In vitro, kallistatin blocked tube formation by inhibiting Flk-1 and GSK-3β phosphorylation. The results demonstrated that continuous administration of kallistatin attenuated BLM-induced pulmonary fibrosis and improved survival of BLM rats. Reducing pulmonary fibrosis was achieved by partial inhibition of pulmonary inflammation and angiogenesis. PMID:28386328

  18. Mitochondrial CaMKII inhibition in airway epithelium protects against allergic asthma

    PubMed Central

    Sebag, Sara C.; Koval, Olha M.; Paschke, John D.; Winters, Christopher J.; Jaffer, Omar A.; Dworski, Ryszard; Sutterwala, Fayyaz S.; Anderson, Mark E.; Grumbach, Isabella M.

    2017-01-01

    Excessive ROS promote allergic asthma, a condition characterized by airway inflammation, eosinophilic inflammation, and increased airway hyperreactivity (AHR). The mechanisms by which airway ROS are increased and the relationship between increased airway ROS and disease phenotypes are incompletely defined. Mitochondria are an important source of cellular ROS production, and our group discovered that Ca2+/calmodulin-dependent protein kinase II (CaMKII) is present in mitochondria and activated by oxidation. Furthermore, mitochondrial-targeted antioxidant therapy reduced the severity of allergic asthma in a mouse model. Based on these findings, we developed a mouse model of CaMKII inhibition targeted to mitochondria in airway epithelium. We challenged these mice with OVA or Aspergillus fumigatus. Mitochondrial CaMKII inhibition abrogated AHR, inflammation, and eosinophilia following OVA and A. fumigatus challenge. Mitochondrial ROS were decreased after agonist stimulation in the presence of mitochondrial CaMKII inhibition. This correlated with blunted induction of NF-κB, the NLRP3 inflammasome, and eosinophilia in transgenic mice. These findings demonstrate a pivotal role for mitochondrial CaMKII in airway epithelium in mitochondrial ROS generation, eosinophilic inflammation, and AHR, providing insights into how mitochondrial ROS mediate features of allergic asthma. PMID:28194433

  19. Chk1 protects against chromatin bridges by constitutively phosphorylating BLM serine 502 to inhibit BLM degradation.

    PubMed

    Petsalaki, Eleni; Dandoulaki, Maria; Morrice, Nick; Zachos, George

    2014-09-15

    Chromatin bridges represent incompletely segregated chromosomal DNA connecting the anaphase poles and can result in chromosome breakage. The Bloom's syndrome protein helicase (BLM, also known as BLMH) suppresses formation of chromatin bridges. Here, we show that cells deficient in checkpoint kinase 1 (Chk1, also known as CHEK1) exhibit higher frequency of chromatin bridges and reduced BLM protein levels compared to controls. Chk1 inhibition leads to BLM ubiquitylation and proteasomal degradation during interphase. Furthermore, Chk1 constitutively phosphorylates human BLM at serine 502 (S502) and phosphorylated BLM localises to chromatin bridges. Mutation of S502 to a non-phosphorylatable alanine residue (BLM-S502A) reduces the stability of BLM, whereas expression of a phospho-mimicking BLM-S502D, in which S502 is mutated to aspartic acid, stabilises BLM and prevents chromatin bridges in Chk1-deficient cells. In addition, wild-type but not BLM-S502D associates with cullin 3, and cullin 3 depletion rescues BLM accumulation and localisation to chromatin bridges after Chk1 inhibition. We propose that Chk1 phosphorylates BLM-S502 to inhibit cullin-3-mediated BLM degradation during interphase. These results suggest that Chk1 prevents deleterious anaphase bridges by stabilising BLM. © 2014. Published by The Company of Biologists Ltd.

  20. Nanoleakage inhibition within hybrid layer using new protective chemicals and their effect on adhesion.

    PubMed

    Dündar, M; Ozcan, M; Cömlekoglu, M E; Sen, B H

    2011-01-01

    Hybrid-layer degradation occurs because of acidic properties of currently used adhesive systems. Titanium tetrafluoride couples with tooth surface, and titanium compounds are not substituted. Caffeic acid phenethyl esther inhibits endogenous matrix metalloproteinases that cause hybrid-layer degradation. It was hypothesized that titanium tetrafluoride and caffeic acid phenethyl esther application on exposed dentine surfaces before adhesive applications would inhibit nanoleakage and hybrid-layer degradation without compromising the bond strength of the adhesives. In ultracut thin sections, human dentine-chemical agent-adhesive composite interfaces were observed under transmission electron microscope with complementary scanning electron microscopy. Microtensile bond strength tests were also accomplished. Titanium tetrafluoride and titanium tetrafluoride + caffeic acid phenethyl esther applications decreased bond strength values. Caffeic acid phenethyl esther showed decreased silver nitrate penetration for cements based on Bisphenol glycydilmethacrylate and methyl methacrylate, whereas cement based on 4-methacryloyloxyethyl trimellitate anhydride methyl methacrylate showed almost no infiltration. Caffeic acid phenethyl esther application before cementation could inhibit nanoleakage and biodegradation of the hybrid layer.

  1. A2E-epoxides damage DNA in retinal pigment epithelial cells. Vitamin E and other antioxidants inhibit A2E-epoxide formation.

    PubMed

    Sparrow, Janet R; Vollmer-Snarr, Heidi R; Zhou, Jilin; Jang, Young P; Jockusch, Steffen; Itagaki, Yasuhiro; Nakanishi, Koji

    2003-05-16

    The autofluorescent pigments that accumulate in retinal pigment epithelial cells with aging and in some retinal disorders have been implicated in the etiology of macular degeneration. The major constituent is the fluorophore A2E, a pyridinium bisretinoid. Light-exposed A2E-laden retinal pigment epithelium exhibits a propensity for apoptosis with light in the blue region of the spectrum being most damaging. Efforts to understand the events precipitating the death of the cells have revealed that during irradiation (430 nm), A2E self-generates singlet oxygen with the singlet oxygen in turn reacting with A2E to generate epoxides at carbon-carbon double bonds. Here we demonstrate that A2E-epoxides, independent of singlet oxygen, exhibit reactivity toward DNA with oxidative base changes being at least one of these lesions. Mass spectrometry revealed that the antioxidants vitamins E and C, butylated hydroxytoluene, resveratrol, a trolox analogue (PNU-83836-E), and bilberry extract reduce A2E-epoxidation, whereas single cell gel electrophoresis and cell viability studies revealed a corresponding reduction in the incidence of DNA damage and cell death. Vitamin E, a lipophilic antioxidant, produced a more pronounced decrease in A2E-epoxidation than vitamin C, and treatment with both vitamins simultaneously did not confer additional benefit. Studies in which singlet oxygen was generated by endoperoxide in the presence of A2E revealed that vitamin E, butylated hydroxytoluene, resveratrol, the trolox analogue, and bilberry reduced A2E-epoxidation by quenching singlet oxygen. Conversely, vitamin C and ginkgolide B were not efficient quenchers of singlet oxygen under these conditions.

  2. Curcumin protects human adipose-derived mesenchymal stem cells against oxidative stress-induced inhibition of osteogenesis.

    PubMed

    Wang, Nan; Wang, Feng; Gao, Youshui; Yin, Peipei; Pan, Chenhao; Liu, Wei; Zhou, Zubin; Wang, Jiaxiang

    2016-11-01

    The detrimental effects of oxidative stress on the skeletal system have been documented, and understanding the mechanisms is important to design a therapeutic strategy. As an antioxidant and anti-inflammatory agent, the active ingredient of turmeric curcumin has been used as medication for numerous complications including bone loss. However, it is unclear if curcumin could influence the osteogenic potential of mesenchymal stem cells (MSCs), particularly in oxidative injuries. Here we demonstrate that curcumin treatment protects cell death caused by hydrogen peroxide (H2O2) exposure in human adipose-derived MSCs in vitro. Importantly, curcumin is able to enhance the osteoblast differentiation of human adipose-derived MSCs that is inhibited by H2O2. Notably, both oxidative stress and the inhibition of Wnt/β-catenin signaling are attenuated by curcumin treatment. These results suggest that curcumin can promote osteoblast differentiation of MSCs and protect the inhibitory effect elicited by oxidative injury. The findings support potential use of curcumin or related antioxidants in MSC-based bone regeneration for disease related with oxidative stress-induced bone loss.

  3. Epigallocatechin-3-gallate inhibits STAT-1 activation and protects cardiac myocytes from ischemia/reperfusion-induced apoptosis.

    PubMed

    Townsend, Paul A; Scarabelli, Tiziano M; Pasini, Evasio; Gitti, Gianluca; Menegazzi, Marta; Suzuki, Hisanori; Knight, Richard A; Latchman, David S; Stephanou, Anastasis

    2004-10-01

    We have previously demonstrated that STAT-1 plays a critical role in promoting apoptotic cell death in cardiac myocytes following ischemia/reperfusion (I/R) injury. Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, has recently been reported to inhibit STAT-1 activity in noncardiac cells. In the present study, we have assessed the protective effects of EGCG and green tea extract (GTE) infusion on both cultures of cardiac myocytes and the isolated rat heart. EGCG reduced STAT-1 phosphorylation and protected cardiac myocytes against I/R-induced apoptotic cell death. Moreover, EGCG reduced the expression of a known STAT-1 pro-apoptotic target gene, Fas receptor. More interestingly, oral administration of GTE as well as EGCG infusion limited the extent of infarct size and attenuated the magnitude of myocyte apoptosis in the isolated rat heart exposed to I/R injury. This reduction cell death was associated with improved hemodynamic recovery and ventricular function in the ischemic/reperfused rat heart. This is the first report to show that consumption of green tea is able to mediate cardioprotection and enhance cardiac function during I/R injury. Because GTE-mediated cardioprotection is achieved, at least in part, through inhibition of STAT-1 activity, we may postulate that a similar action can be implemented in the clinical setting to minimize STAT-1 activation levels in patients with acute coronary artery disease (CAD).

  4. Radiation protection of the gastrointestinal tract and growth inhibition of prostate cancer xenografts by a single compound

    PubMed Central

    Alexeev, Vitali; Lash, Elizabeth; Aguillard, April; Corsini, Laura; Bitterman, Avi; Ward, Keith; Dicker, Adam P.; Linnenbach, Alban; Rodeck, Ulrich

    2014-01-01

    Normal tissue toxicity markedly reduces the therapeutic index of genotoxic anti-cancer agents including ionizing radiation. Countermeasures against tissue damage caused by radiation are limited by their potential to also protect malignant cells and tissues. Here we tested a panel of signal transduction modifiers for selective radioprotection of normal but not tumor tissues. These included three inhibitors of GSK3 (LiCl, SB216763 and SB415286) and two inhibitors of NF-κB (ethyl pyruvate and RTA 408). Among these, the thiol reactive triterpenoid RTA 408 emerged as a robust and effective protector of multiple organ systems (gastrointestinal, skin and hemopoietic) against lethal doses of radiation. RTA 408 preserved survival and proliferation of crypt cells in lethally irradiated small intestines while reducing apoptosis incidence in crypts and villi. In contrast, RTA 408 uniformly inhibited growth of established CWR-22Rv1, LNCaP/C4-2B, PC3 and DU145 xenografts either alone or combined with radiation. Anti-tumor effects in vivo were associated with reduced proliferation and intratumoral apoptosis and with inhibition of NF-κB-dependent transcription in PC3 cells. Selective protection of normal tissue compartments by RTA 408 critically depended on tissue context and could not be replicated in vitro. Collectively, these data highlight the potential of RTA 408 as a cytoprotective agent that may be safely used in chemoradiation approaches. PMID:25398830

  5. Protective effect of Trillium tschonoskii saponin on CCl4-induced acute liver injury of rats through apoptosis inhibition.

    PubMed

    Wu, Hao; Qiu, Yong; Shu, Ziyang; Zhang, Xu; Li, Renpeng; Liu, Su; Chen, Longquan; Liu, Hong; Chen, Ning

    2016-12-01

    To explore hepatoprotective role and underlying mechanisms of Trillium tschonoskii Maxim (TTM), 36 rats were randomly divided into control, CCl4-induced liver injury model, and biphenyl dimethyl dicarboxylate (DDB) and low-, moderate-, and high-dose TTM treatment groups. After CCl4-induced model establishment, the rats from DDB and TTM groups were administrated with DDB at 0.2 g/kg per day and TTM at 0.1, 0.5, and 1.0 g/kg per day, while the rats from control and model groups were administrated with saline. After 5 days of treatments, all rats were sacrificed for determining serum ALT and AST levels and liver index, examining histopathological changes in liver through HE and TUNEL staining, and evaluating TNF-α and IL-6 mRNA expression by real-time PCR, and caspase-3, Bcl-2, and Bax expression by Western blot. Results indicated that CCl4 could induce acute liver injury and abnormal liver function in rats with obvious hepatomegaly, increased liver index, high ALT and AST levels, up-regulated TNF-α and IL-6, and overexpressed Bax and caspase-3. However, DDB and TTM could execute protective role in CCl4-induced liver injury in rats through reducing ALT and AST levels, rescuing hepatomegaly, down-regulating inflammatory factors and inhibiting hepatocyte apoptosis in a dose-dependent manner. Therefore, TTM has obvious protective role in CCl4-induced liver injury of rats through inhibiting hepatocyte apoptosis.

  6. Images and spectra of inhibited light propagation in a 2-dimensional photonic lattice at 1.5 {micro}m

    SciTech Connect

    Gourley, P.L.; Wendt, J.R.; Vawter, G.A.; McDonald, A.E.; Bieber, A.E.

    1996-06-01

    Using infrared light scattering microscopy, the authors have directly observed the inhibition of photon propagation in a 2-dimensional photonic lattice fabricated as a hexagonal array of AlGaAs posts. The lattice was formed by reactive ion etching of {approximately}400 nm diameter posts defined by electron beam lithography. The lattice design parameters correspond to a photonic bandgap near 1.5 {micro}m as calculated by Meade et al. This hexagonal array of posts is an improvement over early honeycomb lattices because it is easier to fabricate. The photonic lattice of 1.4 {micro}m high posts was incorporated into waveguide designed for single mode at 1.5 {micro}m. Several waveguide/lattice combinations were fabricated, including M-bar and K-bar lattice orientations aligned parallel to the waveguide and different numbers of lattice periods. The waveguide/lattice structures were fabricated on GaAs substrates that were subsequently thinned and cleaved to couple light into the waveguide facets. Using a specially designed triple infrared microscope system, they simultaneously imaged the input and output facets and the top surface of the waveguide as laser light was focused onto the input facet. Because of internal scattering in the waveguide, light is scattered upward outward and can be imaged with an infrared camera. Images for reflected input, waveguide scattered light, and transmitted output light for the waveguide with (left images) and without the photonic lattice (right images) are shown. The lefthand image shows how the lattice interrupts the transport of light through the waveguide.

  7. Electric power plants: protective coatings and corrosion inhibition. January, 1966-September, 1981 (citations from the Metals Abstracts data base). Report for Jan 66-Sep 81

    SciTech Connect

    Not Available

    1981-09-01

    Protective coatings for power plants are discussed. Corrosion protection by means of applied coatings or the use of electrochemical inhibition is featured. Particular emphasis is placed on the effects of corrosion on the strength of materials used in various types of power plants, and includes stress corrosion cracking and erosion protection. The effects of cyclic loading and thermal expansion of heat exchanger tubes on corrosion are also included. (Contains 162 citations fully indexed and including a title list.)

  8. Identification of small molecules that inhibit the interaction of TEM8 with anthrax protective antigen using a FRET assay

    PubMed Central

    Cryan, Lorna M.; Habeshian, Kaiane A.; Caldwell, Thomas P.; Morris, Meredith T.; Ackroyd, P. Christine; Christensen, Kenneth A.; Rogers, Michael S.

    2013-01-01

    Tumor marker endothelial 8 (TEM8) is a receptor for the Protective Antigen (PA) component of anthrax toxin. TEM8 is upregulated on endothelial cells lining the blood vessels within tumors, compared to normal blood vessels. A number of studies have demonstrated a pivotal role for TEM8 in developmental and tumor angiogenesis. We have also shown that targeting the anthrax receptors with a mutated form of PA inhibits angiogenesis and tumor formation in vivo. Here we describe the development and testing of a high-throughput fluorescence resonance energy transfer assay to identify molecules that strongly inhibit the interaction of PA and TEM8. The assay we describe is sensitive and robust, with a Z-prime value of 0.8. A preliminary screen of 2310 known bioactive library compounds identified ebselen and thimerosal as inhibitors of the TEM8-PA interaction. These molecules each contain a cysteine-reactive transition metal, and complimentary studies indicate that their inhibition of interaction is due to modification of a cysteine residue in the TEM8 extracellular domain. This is the first demonstration of a high-throughput screening assay that identifies inhibitors of TEM8, with potential application for anti-anthrax and anti-angiogenic diseases. PMID:23479355

  9. 4‑Phenylbutyrate protects rat skin flaps against ischemia‑reperfusion injury and apoptosis by inhibiting endoplasmic reticulum stress.

    PubMed

    Yue, Zhen-Shuang; Zeng, Lin-Ru; Quan, Ren-Fu; Tang, Yang-Hua; Zheng, Wen-Jie; Qu, Gang; Xu, Can-Da; Zhu, Fang-Bing; Huang, Zhong-Ming

    2016-02-01

    4‑phenylbutyrate (4‑PBA) is a low molecular weight fatty acid, which has been demonstrated to regulate endoplasmic reticulum (ER) stress. ER stress‑induced cell apoptosis has an important role in skin flap ischemia; however, a pharmacological approach for treating ischemia‑induced ER dysfunction has yet to be reported. In the present study, the effects of 4‑PBA‑induced ER stress inhibition on ischemia‑reperfusion injury were investigated in the skin flap of rats, and transcriptional regulation was examined. 4‑PBA attenuated ischemia‑reperfusion injury and inhibited cell apoptosis in the skin flap. Furthermore, 4‑PBA reversed the increased expression levels of two ER stress markers: CCAAT/enhancer-binding protein‑homologous protein and glucose‑regulated protein 78. These results suggested that 4‑PBA was able to protect rat skin flaps against ischemia‑reperfusion injury and apoptosis by inhibiting ER stress marker expression and ER stress‑mediated apoptosis. The beneficial effects of 4‑PBA may prove useful in the treatment of skin flap ischemia‑reperfusion injury.

  10. LL202 protects against dextran sulfate sodium-induced experimental colitis in mice by inhibiting MAPK/AP-1 signaling

    PubMed Central

    Zhao, Yue; Hu, Yang; Li, Zhiyu; Guo, Qinglong; Zhao, Kai; Lu, Na

    2016-01-01

    LL202, a newly-synthesized flavonoid derivative, has been reported to inhibit inflammatory-induced angiogenesis. However, the exact role of LL202 in inflammation along with its mechanism has not been explored. In this study, we investigated the anti-inflammatory effect of LL202 on intestinal inflammation by establishing dextran sulfate sodium (DSS)-induced experimental colitis. LL202 attenuated DSS-induced body weight loss, colon length shortening and colonic pathological damage. The inflammatory cells infiltration, myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities were decreased by LL202 in a dose-dependent manner. LL202 reduced the production of pro-inflammatory cytokines in serum and colon of DSS-induced mice as well. Mechanically, LL202 could decrease the expression and nuclear translation of AP-1 to protect against DSS-induced colitis. In lipopolysaccharide (LPS)-induced THP-1 cells, LL202 markedly decreased the secretion, mRNA level and protein expression of IL-1β, IL-6 and TNF-α via inhibiting ERK/JNK/p38 MAPK pathways and the nuclear translocation of AP-1. Furthermore, these findings were confirmed in LPS-induced bone marrow derived macrophages (BMDM). In conclusion, our study demonstrated that LL202 could exert its anti-inflammatory effect via inhibiting MAPK/AP-1 signaling, which suggested that LL202 might be a potential effective drug for the treatment of inflammatory bowel diseases. PMID:27590510

  11. IGF-1 protects against Aβ25-35-induced neuronal cell death via inhibition of PUMA expression and Bax activation.

    PubMed

    Hou, Xunyao; Jin, Yan; Chen, Jian; Hong, Yan; Luo, Dingzhen; Yin, Qingqing; Liu, Xueping

    2017-01-10

    Amyloid-β-peptide (Aβ) is considered to be the toxic species in AD and causes cell death in the affected areas of patient's brain. Insulin-like growth factor 1 (IGF-1) has been reported to attenuate Aβ toxicity in neuronal cells. However, the molecular mechanisms involved in the neuroprotective function of IGF-1 remain largely unknown. In the present study, we for the first time demonstrated that IGF-1 protects against Aβ-induced neurotoxicity via inhibition of PUMA expression and Bax activation. We found that IGF-1 could activate Akt, which in turn inhibited Aβ-induced FOXO3a nuclear translocation and thus decreased the binding ability of FOXO3a to PUMA promoter, leading to decreased PUMA expression. In addition, IGF-1 inhibited the translocation of Bax to the mitochondria induced by Aβ. Notably, addition of wortmannin, a specific inhibitor of PI3K, significantly abolished the neuroprotective effect of IGF-1, suggesting that IGF-1 exerts its anti-apoptotic effect depend on PI3K activity. Our findings may provide new insights into molecular mechanisms mediated by IGF-1 in cell survival against Aβ-induced apoptosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Inhibiting HMGB1 with Glycyrrhizic Acid Protects Brain Injury after DAI via Its Anti-Inflammatory Effect

    PubMed Central

    Pang, Honggang; Huang, Tinqin; Li, Dandong; Zhao, Yonglin; Ma, Xudong

    2016-01-01

    High-mobility group box 1 (HMGB1), a nuclear protein that has endogenous cytokine-like activity, is involved in several neurological diseases by mediating inflammatory response. In this study, a lateral head rotation device was used to establish a rat diffuse axonal injury (DAI) model. The dynamic expression of HMGB1, apoptosis-associated proteins, and proinflammatory cytokines were detected by Western blot, and neuronal apoptosis was observed by TUNEL staining. The extracellular release of HMGB1 and the accumulation of β-APP were observed by immunofluorescence and immunohistochemistry, respectively. The brain injury was indicated by modified neurological severity score (mNSS), brain water content (BWC), and the extravasation of Evans blue. We showed that HMGB1 level obviously decreased within 48 h after DAI, accompanied by neuronal apoptosis, the activation of caspases 3 and 9, and the phosphorylation of BCL-2. Inhibiting HMGB1 with glycyrrhizic acid (GL) can suppress the activation of apoptosis-associated proteins and inhibit the expression of proinflammatory cytokines, which ameliorated motor and cognitive deficits, reduced neuronal apoptosis, and protected the integrity of blood brain barrier (BBB) and axonal injury after experimental DAI in rats. Thus, HMGB1 may be involved in the inflammatory response after DAI, and inhibition of HMGB1 release with GL can notably alleviate the brain injury after DAI. PMID:27041825

  13. The protective effect of dopamine on ventilator-induced lung injury via the inhibition of NLRP3 inflammasome.

    PubMed

    Yang, Xiaomei; Sun, Xiaotong; Chen, Hongli; Xi, Guangmin; Hou, Yonghao; Wu, Jianbo; Liu, Dejie; Wang, Huanliang; Hou, Yuedong; Yu, Jingui

    2017-04-01

    Dopamine (DA), a neurotransmitter, was previously shown to have anti-inflammatory effects. However, its role in ventilator-induced lung injury (VILI) has not been explicitly demonstrated. This study aimed to investigate the therapeutic efficacy and molecular mechanisms of dopamine in VILI. Rats were treated with dopamine during mechanical ventilation. Afterwards, the influence of dopamine on histological changes, pulmonary edema, the lung wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, polymorphonuclear(PMN)counts, inflammatory cytokine levels, and NLRP3 inflammasome protein expression were examined. Our results showed that dopamine significantly attenuated lung tissue injury, the lung W/D ratio, MPO activity and neutrophil infiltration. Moreover, it inhibited inflammatory cytokine levels in the Bronchoalveolar lavage fluid (BAL). In addition, dopamine significantly inhibited ventilation-induced NLRP3 activation. Our experimental findings demonstrate that dopamine exerted protective effects in VILI by alleviating the inflammatory response through inhibition of NLRP3 signaling pathways. The present study indicated that dopamine could be a potential effective therapeutic strategy for the treatment of VILI. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Inhibiting HMGB1 with Glycyrrhizic Acid Protects Brain Injury after DAI via Its Anti-Inflammatory Effect.

    PubMed

    Pang, Honggang; Huang, Tinqin; Song, Jinning; Li, Dandong; Zhao, Yonglin; Ma, Xudong

    2016-01-01

    High-mobility group box 1 (HMGB1), a nuclear protein that has endogenous cytokine-like activity, is involved in several neurological diseases by mediating inflammatory response. In this study, a lateral head rotation device was used to establish a rat diffuse axonal injury (DAI) model. The dynamic expression of HMGB1, apoptosis-associated proteins, and proinflammatory cytokines were detected by Western blot, and neuronal apoptosis was observed by TUNEL staining. The extracellular release of HMGB1 and the accumulation of β-APP were observed by immunofluorescence and immunohistochemistry, respectively. The brain injury was indicated by modified neurological severity score (mNSS), brain water content (BWC), and the extravasation of Evans blue. We showed that HMGB1 level obviously decreased within 48 h after DAI, accompanied by neuronal apoptosis, the activation of caspases 3 and 9, and the phosphorylation of BCL-2. Inhibiting HMGB1 with glycyrrhizic acid (GL) can suppress the activation of apoptosis-associated proteins and inhibit the expression of proinflammatory cytokines, which ameliorated motor and cognitive deficits, reduced neuronal apoptosis, and protected the integrity of blood brain barrier (BBB) and axonal injury after experimental DAI in rats. Thus, HMGB1 may be involved in the inflammatory response after DAI, and inhibition of HMGB1 release with GL can notably alleviate the brain injury after DAI.

  15. PKC{eta} confers protection against apoptosis by inhibiting the pro-apoptotic JNK activity in MCF-7 cells

    SciTech Connect

    Rotem-Dai, Noa; Oberkovitz, Galia; Abu-Ghanem, Sara; Livneh, Etta

    2009-09-10

    Apoptosis is frequently regulated by different protein kinases including protein kinase C family enzymes. Both inhibitory and stimulatory effects were demonstrated for several of the different PKC isoforms. Here we show that the novel PKC isoform, PKC{eta}, confers protection against apoptosis induced by the DNA damaging agents, UVC irradiation and the anti-cancer drug - Camptothecin, of the breast epithelial adenocarcinoma MCF-7 cells. The induced expression of PKC{eta} in MCF-7 cells, under the control of the tetracycline-responsive promoter, resulted in increased cell survival and inhibition of cleavage of the apoptotic marker PARP-1. Activation of caspase-7 and 9 and the release of cytochrome c were also inhibited by the inducible expression of PKC{eta}. Furthermore, JNK activity, required for apoptosis in MCF-7, as indicated by the inhibition of both caspase-7 cleavage and cytochrome c release from the mitochondria in the presence of the JNK inhibitor SP600125, was also suppressed by PKC{eta} expression. Hence, in contrast to most PKC isoforms enhancing JNK activation, our studies show that PKC{eta} is an anti-apoptotic protein, acting as a negative regulator of JNK activity. Thus, PKC{eta} could represent a target for intervention aimed to reduce resistance to anti-cancer treatments.

  16. Biofriendly nanocomposite containers with inhibition properties for the protection of metallic surfaces

    NASA Astrophysics Data System (ADS)

    Vakhitov, T. R.; Katnov, V. E.; Grishin, P. V.; Stepin, S. N.; Grigoriev, D. O.

    2017-03-01

    An attempt to combine two `green' compounds in nanocomposite microcontainers in order to increase protection properties of waterborne acryl-styrene copolymer (ASC) coatings has been made. N-lauroylsarcosine (NLS) served as a corrosion inhibitor, and linseed oil (LO) as a carrier-forming component. LO is compatible with this copolymer and can impart to the coating self-healing properties. For the evaluation of the protective performance, three types of coatings were compared. In the first two, NLS was introduced in the coating formulation in the forms of free powder and micro-containers filled with LO, correspondingly. The last one was a standard ASC coating without inhibitor at all. Low-carbon steel substrates were coated by these formulations by spraying and subjected subsequently to the neutral salt spray test according to DIN ISO 9227. Results of these tests as well as the data obtained by electrochemical study suggest that such containers can be used for the improvement of adhesion of ASC-based coatings to the substrate and for the enhancement of their protective performance upon integrity damage, whereas the barrier properties of intact coatings were decreased.

  17. Adenosine A2A receptors and uric acid mediate protective effects of inosine against TNBS-induced colitis in rats.

    PubMed

    Rahimian, Reza; Fakhfouri, Gohar; Daneshmand, Ali; Mohammadi, Hamed; Bahremand, Arash; Rasouli, Mohammad Reza; Mousavizadeh, Kazem; Dehpour, Ahmad Reza

    2010-12-15

    Inflammatory bowel disease comprises chronic recurrent inflammation of gastrointestinal tract. This study was conducted to investigate inosine, a potent immunomodulator, in 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced chronic model of experimental colitis, and contribution of adenosine A(2A) receptors and the metabolite uric acid as possible underlying mechanisms. Experimental colitis was rendered in rats by a single colonic administration of 10 mg of TNBS. Inosine, potassium oxonate (a hepatic uricase inhibitor), SCH-442416 (a selective adenosine A(2A) receptor antagonist), inosine+potassium oxonate, or inosine+SCH-442416 were given twice daily for 7 successive days. At the end of experiment, macroscopic and histopathologic scores, colonic malondialdehyde (MDA), Tumor Necrosis Factor-alpha (TNF-α) and Interleukin-1beta (IL-1β) levels, and myeloperoxidase (MPO) activity were assessed. Plasma uric acid level was measured throughout the experiment. Both macroscopic and histological features of colonic injury were markedly ameliorated by either inosine, oxonate or inosine+oxonate. Likewise, the elevated amounts of MPO and MDA abated as well as those of TNF-α and IL-1β (P<0.05). SCH-442416 partially reversed the effect of inosine on theses markers, while inosine+oxonate showed a higher degree of protection than each treatment alone (P<.0.05). No significant difference was observed between TNBS and SCH-442416 groups. Uric acid levels were significantly higher in inosine or oxonate groups compared to control. Inosine+oxonate resulted in an even more elvelated uric acid level than each treatment alone (P<0.05). Inosine elicits notable anti-inflammatory effects on TNBS-induced colitis in rats. Uric acid and adenosine A(2A) receptors contribute to these salutary properties.

  18. Protective Effects of Dioscin against Lipopolysaccharide-Induced Acute Lung Injury through Inhibition of Oxidative Stress and Inflammation

    PubMed Central

    Yao, Hong; Sun, Yiping; Song, Shasha; Qi, Yan; Tao, Xufeng; Xu, Lina; Yin, Lianhong; Han, Xu; Xu, Youwei; Li, Hua; Sun, Huijun; Peng, Jinyong

    2017-01-01

    The protective effects of dioscin, a natural steroidal saponin from some medicinal plants including Dioscorea nipponica Makino, against lipopolysaccharide (LPS)- induced acute liver and renal damages have been reported in our previous works. However, the actions of dioscin against LPS-induced acute lung injury (ALI) is still unknown. In the present study, we investigated the effects and mechanisms of dioscin against LPS-induced ALI in vitro and in vivo. The results showed that dioscin obviously inhibited cell proliferation and markedly decreased reactive oxidative species level in 16HBE cells treated by LPS. In addition, dioscin significantly protected LPS-induced histological changes, inhibited the infiltration of inflammatory cells, as well as decreased the levels of MDA, SOD, NO and iNOS in mice and rats (p < 0.05). Mechanistically, dioscin significantly decreased the protein levels of TLR4, MyD88, TRAF6, TKB1, TRAF3, phosphorylation levels of PI3K, Akt, IκBα, NF-κB, and the mRNA levels of IL-1β, IL-6, and TNF-α against oxidative stress and inflammation (p < 0.05). Dioscin significantly reduced the overexpression of TLR4, and obviously down-regulated the levels of MyD88, TRAF6, TKB1, TRAF3, p-PI3K, p-Akt, p-IκBα, and p-NF-κB. These findings provide new perspectives for the study of ALI. Dioscin has protective effects on LPS-induced ALI via adjusting TLR4/MyD88- mediated oxidative stress and inflammation, which should be a potent drug in the treatment of ALI. PMID:28377715

  19. Curcumin inhibits prosurvival pathways in chronic lymphocytic leukemia B cells and may overcome their stromal protection in combination with EGCG.

    PubMed

    Ghosh, Asish K; Kay, Neil E; Secreto, Charla R; Shanafelt, Tait D

    2009-02-15

    Chronic lymphocytic leukemia (CLL) is incurable with current chemotherapy treatments. Curcumin (diferuloylmethane), an active ingredient in the spice turmeric, inhibits tumor metastasis, invasion, and angiogenesis in tumor cell lines. We evaluated the effects of curcumin on the viability of primary CLL B cells and its ability to overcome stromal mediated protection. The in vitro effect of curcumin on primary CLL B cells was evaluated using fluorescence activated cell sorter analysis and Western blotting. For some experiments, CLL B cells were cocultured with human stromal cells to evaluate the effects of curcumin on leukemia cells cultured in their microenvironment. Finally, the effect of curcumin in combination with the green tea extract epigallocatechin-3 gallate (EGCG) was evaluated. Curcumin induced apoptosis in CLL B cells in a dose-dependent (5-20 micromol/L) manner and inhibited constitutively active prosurvival pathways, including signal transducers and activators of transcription 3 (STAT3), AKT, and nuclear factor kappaB. Moreover, curcumin suppressed expression of the anti-apoptotic proteins Mcl-1 and X-linked inhibitor of apoptosis protein (XIAP), and up-regulated the pro-apoptotic protein BIM. Coculture of CLL B cells with stromal cells resulted in elevated levels of STAT3, increased expression of Mcl-1 and XIAP, and decreased sensitivity to curcumin. When curcumin was administered simultaneously with EGCG, antagonism was observed for most patient samples. In contrast, sequential administration of these agents led to substantial increases in CLL B-cell death and could overcome stromal protection. Curcumin treatment was able to overcome stromal protection of CLL B cells on in vitro testing and to synergize with EGCG when administered in a sequential fashion. Additional evaluation of curcumin as a potential therapeutic agent for treatment of CLL seems warranted.

  20. Protective effect of caspase inhibition on compression-induced muscle damage

    PubMed Central

    Teng, Bee T; Tam, Eric W; Benzie, Iris F; Siu, Parco M

    2011-01-01

    Abstract There are currently no effective therapies for treating pressure-induced deep tissue injury. This study tested the efficacy of pharmacological inhibition of caspase in preventing muscle damage following sustained moderate compression. Adult Sprague–Dawley rats were subjected to prolonged moderate compression. Static pressure of 100 mmHg compression was applied to an area of 1.5 cm2 in the tibialis region of the right limb of the rats for 6 h each day for two consecutive days. The left uncompressed limb served as intra-animal control. Rats were randomized to receive either vehicle (DMSO) as control treatment (n = 8) or 6 mg kg−1 of caspase inhibitor (z-VAD-fmk; n = 8) prior to the 6 h compression on the two consecutive days. Muscle tissues directly underneath the compression region of the compressed limb and the same region of control limb were harvested after the compression procedure. Histological examination and biochemical/molecular measurement of apoptosis and autophagy were performed. Caspase inhibition was effective in alleviating the compression-induced pathohistology of muscle. The increases in caspase-3 protease activity, TUNEL index, apoptotic DNA fragmentation and pro-apoptotic factors (Bax, p53 and EndoG) and the decreases in anti-apoptotic factors (XIAP and HSP70) observed in compressed muscle of DMSO-treated animals were not found in animals treated with caspase inhibitor. The mRNA content of autophagic factors (Beclin-1, Atg5 and Atg12) and the protein content of LC3, FoxO3 and phospho-FoxO3 that were down-regulated in compressed muscle of DMSO-treated animals were all maintained at their basal level in the caspase inhibitor treated animals. Our data provide evidence that caspase inhibition attenuates compression-induced muscle apoptosis and maintains the basal autophagy level. These findings demonstrate that pharmacological inhibition of caspase/apoptosis is effective in alleviating muscle damage as induced by prolonged compression

  1. Nanomolar vitamin E alpha-tocotrienol inhibits glutamate-induced activation of phospholipase A2 and causes neuroprotection.

    PubMed

    Khanna, Savita; Parinandi, Narasimham L; Kotha, Sainath R; Roy, Sashwati; Rink, Cameron; Bibus, Douglas; Sen, Chandan K

    2010-03-01

    Our previous works have elucidated that the 12-lipoxygenase pathway is directly implicated in glutamate-induced neural cell death, and that such that toxicity is prevented by nM concentrations of the natural vitamin E alpha-tocotrienol (TCT). In the current study we tested the hypothesis that phospholipase A(2) (PLA(2)) activity is sensitive to glutamate and mobilizes arachidonic acid (AA), a substrate for 12-lipoxygenase. Furthermore, we examined whether TCT regulates glutamate-inducible PLA(2) activity in neural cells. Glutamate challenge induced the release of [(3)H]AA from HT4 neural cells. Such response was attenuated by calcium chelators (EGTA and BAPTA), cytosolic PLA(2) (cPLA(2))-specific inhibitor (AACOCF(3)) as well as TCT at 250 nM. Glutamate also caused the elevation of free polyunsaturated fatty acid (AA and docosahexaenoic acid) levels and disappearance of phospholipid-esterified AA in neural cells. Furthermore, glutamate induced a time-dependent translocation and enhanced serine phosphorylation of cPLA(2) in the cells. These effects of glutamate on fatty acid levels and on cPLA(2) were significantly attenuated by nM TCT. The observations that AACOCF(3), transient knock-down of cPLA(2) as well as TCT significantly protected against the glutamate-induced death of neural cells implicate cPLA(2) as a TCT-sensitive mediator of glutamate induced neural cell death. This work presents first evidence recognizing glutamate-induced changes in cPLA(2) as a novel mechanism responsible for neuroprotection observed in response to nanomolar concentrations of TCT.

  2. Celastrol protects mouse retinas from bright light-induced degeneration through inhibition of oxidative stress and inflammation.

    PubMed

    Bian, Minjuan; Du, Xiaoye; Cui, Jingang; Wang, Peiwei; Wang, Wenjian; Zhu, Weiliang; Zhang, Teng; Chen, Yu

    2016-02-27

    Photoreceptor death leads to vision impairment in several retinal degenerative disorders. Therapies protecting photoreceptor from degeneration remain to be developed. Anti-inflammation, anti-oxidative stress, and neuroprotective effects of celastrol have been demonstrated in a variety of disease models. The current study aimed to investigate the photoreceptor protective effect of celastrol. Bright light-induced retinal degeneration in BALB/c mice was used, and morphological, functional, and molecular changes of retina were evaluated in the absence and presence of celastrol treatment. Significant morphological and functional protection was observed as a result of celastrol treatment in bright light-exposed BALB/c mice. Celastrol treatment resulted in suppression of cell death in photoreceptor cells, alleviation of oxidative stress in the retinal pigment epithelium and photoreceptors, downregulation of retinal expression of proinflammatory genes, and suppression of microglia activation and gliosis in the retina. Additionally, leukostasis was found to be induced in the retinal vasculature in light-exposed BALB/c mice, which was significantly attenuated by celastrol treatment. In vitro, celastrol attenuated all-trans-retinal-induced oxidative stress in cultured APRE19 cells. Moreover, celastrol treatment significantly suppressed lipopolysaccharides-stimulated expression of proinflammatory genes in both APRE19 and RAW264.7 cells. The results demonstrated for the first time that celastrol prevents against light-induced retinal degeneration through inhibition of retinal oxidative stress and inflammation.

  3. A novel pyrazole derivative protects from ovariectomy-induced osteoporosis through the inhibition of NADPH oxidase

    PubMed Central

    Joo, Jung Hee; Huh, Jeong-Eun; Lee, Jee Hyun; Park, Doo Ri; Lee, Yoonji; Lee, Seul Gee; Choi, Sun; Lee, Hwa Jeong; Song, Seong-Won; Jeong, Yongmi; Goo, Ja-Il; Choi, Yongseok; Baek, Hye Kyung; Yi, Sun Shin; Park, Soo Jin; Lee, Ji Eun; Ku, Sae Kwang; Lee, Won Jae; Lee, Kee-In; Lee, Soo Young; Bae, Yun Soo

    2016-01-01

    Osteoclast cells (OCs) are differentiated from bone marrow-derived macrophages (BMMs) by activation of receptor activator of nuclear factor κB (NF-κB) ligand (RANKL). Activation of NADPH oxidase (Nox) isozymes is involved in RANKL-dependent OC differentiation, implicating Nox isozymes as therapeutic targets for treatment of osteoporosis. Here, we show that a novel pyrazole derivative, Ewha-18278 has high inhibitory potency on Nox isozymes. Blocking the activity of Nox with Ewha-18278 inhibited the responses of BMMs to RANKL, including reactive oxygen species (ROS) generation, activation of mitogen-activated protein (MAP) kinases and NF-κB, and OC differentiation. To evaluate the anti-osteoporotic function of Ewha-18278, the derivative was applied to estrogen-deficient ovariectomized (OVX) ddY mice. Oral administration of Ewha-18278 (10 mg/kg/daily, 4 weeks) into the mice recovered bone mineral density, trabecular bone volume, trabecular bone length, number and thickness, compared to control OVX ddY mice. Moreover, treatment of OVX ddY mice with Ewha-18278 increased bone strength by increasing cortical bone thickness. We provide that Ewha-18278 displayed Nox inhibition and blocked the RANKL-dependent cell signaling cascade leading to reduced differentiation of OCs. Our results implicate Ewha-18278 as a novel therapeutic agent for the treatment of osteoporosis. PMID:26975635

  4. Inhibition of TLR4 protects rat islets against lipopolysaccharide-induced dysfunction.

    PubMed

    Wang, Xiao; Ge, Qin Min; Bian, Fan; Dong, Yan; Huang, Chun Mei

    2017-02-01

    Oxidative stress leads to dysfunction in pancreatic cells, causing a reduction in insulin secretion following exposure to glucose. Toll-like receptor 4 (TLR4) may be activated by exposure to lipopolysaccharide (LPS) stress. TLR4 may mediate the initiation of inflammatory and immune defense responses; however, the importance of the LPS/TLR4 interaction in apoptosis induced by oxidative stress in pancreatic β cells remains to be elucidated. The present study aimed to investigate the importance of TLR4 during LPS‑induced oxidative stress, apoptosis and dysfunction of insulin secretion in isolated islets of rats. LPS‑induced stimulation of TLR4 increased the production of reactive oxygen species and promoted apoptosis by upregulating the expression levels of caspase‑3, poly ADP ribose polymerase and altering the expression ratio of B‑cell lymphoma‑2 (Bcl‑2)/Bcl‑2 associated X protein. Additionally, the insulin secretion of islets cells was reduced. Anti‑TLR4 antibody and a knockdown of TLR4 by TLR4‑short hairpin RNA were used to inhibit TLR4 activity, which may reverse LPS‑induced events. The present study determined that in islets exposed to LPS oxidative stress, dysfunction may be partly mediated via the TLR4 pathway. Inhibition of TLR4 may prevent dysfunction of rat islets due to oxidative stress. The present study revealed that targeting the LPS/TLR4 signaling pathway and antioxidant therapy may be a novel treatment for the severely septic patients with hyperglycemia stress.

  5. MLN4924 protects against bleomycin-induced pulmonary fibrosis by inhibiting the early inflammatory process

    PubMed Central

    Deng, Qi; Zhang, Jiaojiao; Gao, Yaqun; She, Xiaofei; Wang, Yunchao; Wang, Yilin; Ge, Xin

    2017-01-01

    Pulmonary fibrosis is a complex pathological process characterized by massive destruction of the structure of lung tissues and aggravated pulmonary function impairment. The underlying mechanisms of pulmonary fibrosis are incompletely understood and therefore limited treatment options are available currently. Here, we report that MLN4924, an NEDD8 activation enzyme (NAE) activity-inhibiting molecule, blocks the maintenance and progression of established pulmonary fibrosis. We found that MLN4924 acts against bleomycin-induced pulmonary fibrosis mainly at the early inflammatory stage. Pharmacologically targeting the neddylation of Cullin-Ring E3 ligase (CRL) by MLN4924, significantly abrogated NF-κB responses, suppressed MAPK activity, and reduced secretion of TNF-α-elicited pro-inflammatory cytokines and MCP1-induced chemokines. MLN4924 inhibited pro-inflammatory responses while maintaining or increasing the production of the anti-inflammatory mediators such as anti-inflammatory interleukins (ILs) following bleomycin administration, which is closely correlated to its blocking NF-κB-mediated signaling. Consistently, our studies identified MLN4924 as a promising therapeutic drug for pulmonary fibrosis and suggested a potential role of MLN4924 that fine tunes the MAPK signaling pathway controlling the inflammatory reactions at the early stages of pulmonary fibrosis. In addition, our findings may broaden the potential practical application of MLN4924 as an effective therapeutic strategy against other inflammation-associated diseases. PMID:28469786

  6. Protective effects of berberine against doxorubicin-induced cardiotoxicity in rats by inhibiting metabolism of doxorubicin.

    PubMed

    Hao, Gang; Yu, Yunli; Gu, Bingren; Xing, Yiwen; Xue, Man

    2015-01-01

    1. The clinical use of doxorubicin, an effective anticancer drug, is severely hampered by its cardiotoxicity. Berberine, a botanical alkaloid, has been reported to possess cardioprotective and antitumor effects. In this study, we investigated the cardioprotective effect of berberine on doxorubicin-induced cardiotoxicity and the effect of berberine on the metabolism of doxorubicin. 2. Adult male Sprague-Dawley rats were administered doxorubicin in the presence or absence of berberine for 2 weeks. Administration of berberine effectively prevented doxorubicin-induced body weight reduction and mortality in rats. 3. Berberine reduced the activity of myocardial enzymes, including aspartate aminotransferase (AST), creatine kinase (CK), CK isoenzyme (CK-MB) and lactate dehydrogenase (LDH). Echocardiographic examination further demonstrated that berberine effectively ameliorated cardiac dysfunction induced by doxorubicin. 4. Berberine inhibited the metabolism of doxorubicin in the cytoplasm of rat heart and reduced the accumulation of doxorubicinol (a secondary alcohol metabolite of doxorubicin) in heart. 5. These data showed that berberine alleviated the doxorubicin-induced cardiotoxicity in rats via inhibition of the metabolism of doxorubicin and reduced accumulation of doxorubicinol selectively in hearts.

  7. Verapamil protects against cartilage degradation in osteoarthritis by inhibiting Wnt/β-catenin signaling.

    PubMed

    Takamatsu, Akira; Ohkawara, Bisei; Ito, Mikako; Masuda, Akio; Sakai, Tadahiro; Ishiguro, Naoki; Ohno, Kinji

    2014-01-01

    In past years, the canonical Wnt/β-catenin signaling pathway has emerged as a critical regulator of cartilage development and homeostasis. FRZB, a soluble antagonist of Wnt signaling, has been studied in osteoarthritis (OA) animal models and OA patients as a modulator of Wnt signaling. We screened for FDA-approved drugs that induce FRZB expression and suppress Wnt/β-catenin signaling. We found that verapamil, a widely prescribed L-type calcium channel blocker, elevated FRZB expression and suppressed Wnt/β-catenin signaling in human OA chondrocytes. Expression and nuclear translocation of β-catenin was attenuated by verapamil in OA chondrocytes. Lack of the verapamil effects in LiCl-treated and FRZB-downregulated OA chondrocytes also suggested that verpamil suppressed Wnt signaling by inducing FRZB. Verapamil enhanced gene expressions of chondrogenic markers of ACAN encoding aggrecan, COL2A1 encoding collagen type II α1, and SOX9, and suppressed Wnt-responsive AXIN2 and MMP3 in human OA chondrocytes. Verapamil ameliorated Wnt3A-induced proteoglycan loss in chondrogenically differentiated ATDC5 cells. Verapamil inhibited hypertrophic differentiation of chondrocytes in the explant culture of mouse tibiae. Intraarticular injection of verapamil inhibited OA progression as well as nuclear localizations of β-catenin in a rat OA model. We propose that verapamil holds promise as a potent therapeutic agent for OA by upregulating FRZB and subsequently downregulating Wnt/β-catenin signaling.

  8. Kallistatin protects against sepsis-related acute lung injury via inhibiting inflammation and apoptosis.

    PubMed

    Lin, Wei-Chieh; Chen, Chang-Wen; Huang, Yu-Wen; Chao, Lee; Chao, Julie; Lin, Yee-Shin; Lin, Chiou-Feng

    2015-07-22

    Kallistatin, an endogenous plasma protein, exhibits pleiotropic properties in inhibiting inflammation, oxidative stress and apoptosis, as evidenced in various animal models and cultured cells. Here, we demonstrate that kallistatin levels were positively correlated with the concentration of total protein in bronchoalveolar lavage fluids (BALF) from patients with sepsis-related acute respiratory distress syndrome (ARDS), indicating a compensatory mechanism. Lower ratio of kallistatin to total protein in BALF showed a significant trend toward elevated neutrophil counts (P = 0.002) in BALF and increased mortality (P = 0.046). In lipopolysaccharide (LPS)-treated mice, expression of human kallistatin in lung by gene transfer with human kallistatin-encoding plasmid ameliorated acute lung injury (ALI) and reduced cytokine/chemokine levels in BALF. These mice exhibited attenuated lung epithelial apoptosis and decreased Fas/FasL expression compared to the control mice. Mouse survival was improved by kallistatin gene transfer or recombinant human kallistatin treatment after LPS challenge. In LPS-stimulated A549 human lung epithelial cells, kallistatin attenuated apoptosis, down-regulated Fas/FasL signaling, suppressed intracellular reactive oxygen species (ROS) and inhibited ROS-mediated NF-κB activation and inflammation. Furthermore, LPS-induced apoptosis was blocked by antioxidant N-acetylcysteine or NF-κB inhibitor via down-regulating Fas expression. These findings suggest the therapeutic potential of kallistatin for sepsis-related ALI/ARDS.

  9. Adenosine A2a receptor stimulation blocks development of nonalcoholic steatohepatitis in mice by multilevel inhibition of signals that cause immunolipotoxicity.

    PubMed

    Alchera, Elisa; Rolla, Simona; Imarisio, Chiara; Bardina, Valentina; Valente, Guido; Novelli, Francesco; Carini, Rita

    2016-12-06

    Lipotoxicity and immunoinflammation are associated with the evolution of steatosis toward nonalcoholic steatohepatitis (NASH). This study reports the ability of adenosine A2a receptor (A2aR) activation to inhibit NASH development by modulating the responses of CD4(+) T-helper (Th) cells to avoid an immuno-mediated potentiation of lipotoxicity. The effect of the A2aR agonist CGS21680 on immunoinflammatory signals, CD4(+)Th cell infiltration and immunolipotoxicity was analyzed in steatotic C57BL/6 mice fed with a methionine-choline-deficient (MCD) diet and in mouse hepatocytes exposed to palmitic acid (PA). CGS21680 inhibited NASH development in steatotic mice and decreased cytokines and chemokines involved in Th cell recruitment or polarization (namely CXCL10, CCL2, tumor necrosis factor alfa [TNFα], tumor growth factor [TGFβ], and IL-12). CGS21680 also reduced the expansion of Th17, Th22, and Th1 cells and increased the immunosuppressive activity of T regulatory cells. In PA-treated mice hepatocytes, CGS21680 inhibited the production of CXCL10, TNFα, TGFβ, IL-12, and CCL2; CGS21680 also prevented JNK-dependent lipotoxicity and its intensification by IL-17 or IL-17 plus IL-22 through Akt/PI3-kinase stimulation and inhibition of the negative regulator of PI3-kinase, (phosphatase and tensin homologue deleted from chromosome 10 (PTEN), which is upregulated by IL-17. In MCD livers, CGS21680 reduced JNK activation and PTEN expression and increased Akt phosphorylation. In conclusion, A2aR stimulation inhibited NASH development by reducing Th17 cell expansion and inhibiting the exacerbation of the IL-17-induced JNK-dependent lipotoxicity. These data promote the implementation of further studies to evaluate the potential clinical application of A2aR agonists that, by being able to function as both cytoprotective and immunomodulatory agents, could efficiently antagonize the multi-faced pathogenesis of NASH.

  10. In vitro assessment of CYP1A2 and 2C9 inhibition potential of Withania somnifera and Centella asiatica in human liver microsomes.

    PubMed

    Savai, Jay; Varghese, Alice; Pandita, Nancy; Chintamaneni, Meena

    2015-06-01

    Several herbal drugs and allopathic medicines when co-administered can lead to severe herb-drug interactions. Hence, this study was undertaken in order to assess the in vitro inhibition potential of Withania somnifera and Centella asiatica with cytochrome P450 (CYP) 1A2 and 2C9 enzyme using human liver microsomes. Inhibitory potential of crude extracts of both the medicinal plants along with their principal phytoconstituents were investigated using selective probe substrate technique. IC50, Ki values and mode of inhibition were determined. The results of the study revealed that W. somnifera showed no significant interaction with both the isoforms of CYP. However, ethanolic extract of C. asiatica significantly inhibited both CYP1A2 (IC50 value - 42.23±3.65 μg/mL/Ki value - 14.93±4.59 μg/mL) and 2C9 enzyme (IC50 value - 48.41±4.64 μg/mL/Ki value - 23.89±3.14 μg/mL) in a competitive manner. The flavonoids, quercetin and kaempferol showed potent (IC50 values less than 10 μM) inhibition of CYP1A2 activity with no significant inhibition of CYP2C9 enzyme. Thus, these findings of the study might be helpful for safe and effective use of C. asiatica in clinical practice. However, its in vivo interaction study in humans is still warranted.

  11. Inhibition of the plasma SCUBE1, a novel platelet adhesive protein, protects mice against thrombosis.

    PubMed

    Wu, Meng-Ying; Lin, Yuh-Charn; Liao, Wei-Ju; Tu, Cheng-Fen; Chen, Ming-Huei; Roffler, Steve R; Yang, Ruey-Bing

    2014-07-01

    Signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1), a secreted and surface-exposed glycoprotein on activated platelets, promotes platelet-platelet interaction and supports platelet-matrix adhesion. Its plasma level is a biomarker of platelet activation in acute thrombotic diseases. However, the exact roles of plasma SCUBE1 in vivo remain undefined. We generated new mutant (Δ) mice lacking the soluble but retaining the membrane-bound form of SCUBE1. Plasma SCUBE1-depleted Δ/Δ mice showed normal hematologic and coagulant features and expression of major platelet receptors, but Δ/Δ platelet-rich plasma showed impaired platelet aggregation in response to ADP and collagen treatment. The addition of purified recombinant SCUBE1 protein restored the aggregation of platelets in Δ/Δ platelet-rich plasma and further enhanced platelet aggregation in +/+ platelet-rich plasma. Plasma deficiency of SCUBE1 diminished arterial thrombosis in mice and protected against lethal thromboembolism induced by collagen-epinephrine treatment. Last, antibodies directed against the epidermal growth factor-like repeats of SCUBE1, which are involved in trans-homophilic protein-protein interactions, protected mice against fatal thromboembolism without causing bleeding in vivo. We conclude that plasma SCUBE1 participates in platelet aggregation by bridging adjacent activated platelets in thrombosis. Blockade of soluble SCUBE1 might represent a novel antithrombotic strategy. © 2014 American Heart Association, Inc.

  12. Development of benzimidazole derivatives to inhibit HIV-1 replication through protecting APOBEC3G protein.

    PubMed

    Pan, Ting; He, Xin; Chen, Bing; Chen, Hui; Geng, Guannan; Luo, Haihua; Zhang, Hui; Bai, Chuan

    2015-05-05

    Human APOBEC3G (apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G, A3G) is a potent restriction factor against human immunodeficiency virus type 1 (HIV-1) by inducing hypermutation of G to A in viral genome after its incorporation into virions. HIV-1 Vif (Virion Infectivity Factor) counteracts A3G by inducing ubiquitination and proteasomal degradation of A3G protein. Vif-A3G axis therefore is a promising therapeutic target of HIV-1. Here we report the screening, synthesis and SAR studies of benzimidazole derivatives as potent inhibitors against HIV-1 replication via protecting A3G protein. Based on the steep SAR of the benzimidazole scaffold, we identified compound 14 and 26 which provided the best potency, with IC50 values of 3.45 nM and 58.03 nM respectively in the anti-HIV-1 replication assay in H9 cells. Compound 14 and 26 also afforded protective effects on A3G protein level. Both compounds have been proved to be safe in acute toxicological studies. Taken together, we suggest that these two benzimidazole derivatives can be further developed as a new category of anti-HIV-1 leads.

  13. Grape seed proanthocyanidines and skin cancer prevention: inhibition of oxidative stress and protection of immune system.

    PubMed

    Katiyar, Santosh K

    2008-06-01

    Overexposure of the skin to UV radiation has a variety of adverse effects on human health, including the development of skin cancers. There is a need to develop nutrition-based efficient chemopreventive strategies. The proanthocyanidins present in grape seeds (Vitis vinifera) have been shown to have some biological effects, including prevention of photocarcinogenesis. The present communication discusses the in vitro and in vivo studies of the possible protective effect of grape seed proanthocyanidins (GSPs) and the molecular mechanism for these effects. In SKH-1 hairless mice, dietary supplementation with GSPs is associated with a decrease of UVB-induced skin tumor development in terms of tumor incidence, tumor multiplicity, and a decrease in the malignant transformation of papillomas to carcinomas. It is suggested that the chemopreventive effects of dietary GSPs are mediated through the attenuation of UV-induced: (i) oxidative stress; (ii) activation of mitogen-activated protein kinases and nuclear factor-kappa B (NF-kappaB) signaling pathways; and (iii) immunosuppression through alterations in immunoregulatory cytokines. Collectively, these studies indicate protective potential of GSPs against experimental photocarcinogenesis in SKH-1 hairless mice, and the possible mechanisms of action of GSPs, and suggest that dietary GSPs could be useful in the attenuation of the adverse UV-induced health effects in human skin.

  14. Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway

    PubMed Central

    Li, Qing-rong; Wang, Zhuo; Zhou, Wei; Fan, Shou-rui; Ma, Run; Xue, Li; Yang, Lu; Li, Ya-shan; Tan, Hong-li; Shao, Qing-hua; Yang, Hong-ying

    2016-01-01

    Epalrestat is a noncompetitive and reversible aldose reductase inhibitor used for the treatment of diabetic neuropathy. This study assumed that epalrestat had a protective effect on diabetic peripheral nerve injury by suppressing the expression of aldose reductase in peripheral nerves of diabetes mellitus rats. The high-fat and high-carbohydrate model rats were established by intraperitoneal injection of streptozotocin. Peripheral neuropathy occurred in these rats after sustaining high blood glucose for 8 weeks. At 12 weeks after streptozotocin injection, rats were intragastrically administered epalrestat 100 mg/kg daily for 6 weeks. Transmission electron microscope revealed that the injuries to myelinated nerve fibers, non-myelinated nerve fibers and Schwann cells of rat sciatic nerves had reduced compared to rats without epalrestat administuation. Western blot assay and immunohistochemical results demonstrated that after intervention with epalrestat, the activities of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase gradually increased, but aldose reductase protein expression gradually diminished. Results confirmed that epalrestat could protect against diabetic peripheral neuropathy by relieving oxidative stress and suppressing the polyol pathway. PMID:27073391

  15. Grape seed proanthocyanidines and skin cancer prevention: Inhibition of oxidative stress and protection of immune system

    PubMed Central

    Katiyar, Santosh K.

    2008-01-01

    Overexposure of the skin to ultraviolet (UV) radiation has a variety of adverse effects on human health, including the development of skin cancers. There is a need to develop nutrition-based efficient chemopreventive strategies. The proanthocyanidins present in grape seeds (Vitis vinifera) have been shown to have some biological effects, including prevention of photocarcinogenesis. The present communication discusses the in vitro and in vivo studies of the possible protective effect of grape seed proanthocyanidins (GSPs) and the molecular mechanism for these effects. In SKH-1 hairless mice, dietary supplementation with GSPs is associated with a decrease of UVB-induced skin tumor development in terms of tumor incidence, tumor multiplicity, and a decrease in the malignant transformation of papillomas to carcinomas. It is suggested that the chemopreventive effects of dietary GSPs are mediated through the attenuation of UV-induced: (a) oxidative stress; (b) activation of mitogen-activated protein kinases and nuclear factor-κB signaling pathways; and (c) immunosuppression through alterations in immunoregulatory cytokines. Collectively, these studies indicate protective potential of GSPs against experimental photocarcinogenesis in SKH-1 hairless mice, and the possible mechanisms of action of GSPs, and suggest that dietary GSPs could be useful in the attenuation of the adverse UV-induced health effects in human skin. PMID:18384090

  16. Asp1 from Schizosaccharomyces pombe binds a [2Fe-2S](2+) cluster which inhibits inositol pyrophosphate 1-phosphatase activity.

    PubMed

    Wang, Huanchen; Nair, Vasudha S; Holland, Ashley A; Capolicchio, Samanta; Jessen, Henning J; Johnson, Michael K; Shears, Stephen B

    2015-10-27

    Iron-sulfur (Fe-S) clusters are widely distributed protein cofactors that are vital to cellular biochemistry and the maintenance of bioenergetic homeostasis, but to our knowledge, they have never been identified in any phosphatase. Here, we describe an iron-sulfur cluster in Asp1, a dual-function kinase/phosphatase that regulates cell morphogenesis in Schizosaccharomyces pombe. Full-length Asp1, and its phosphatase domain (Asp1(371-920)), were each heterologously expressed in Escherichia coli. The phosphatase activity is exquisitely specific: it hydrolyzes the 1-diphosphate from just two members of the inositol pyrophosphate (PP-InsP) signaling family, namely, 1-InsP7 and 1,5-InsP8. We demonstrate that Asp1 does not hydrolyze either InsP6, 2-InsP7, 3-InsP7, 4-InsP7, 5-InsP7, 6-InsP7, or 3,5-InsP8. We also recorded 1-phosphatase activity in a human homologue of Asp1, hPPIP5K1, which was heterologously expressed in Drosophila S3 cells with a biotinylated N-terminal tag, and then isolated from cell lysates with avidin beads. Purified, recombinant Asp1(371-920) contained iron and acid-labile sulfide, but the stoichiometry (0.8 atoms of each per protein molecule) indicates incomplete iron-sulfur cluster assembly. We reconstituted the Fe-S cluster in vitro under anaerobic conditions, which increased the stoichiometry to approximately 2 atoms of iron and acid-labile sulfide per Asp1 molecule. The presence of a [2Fe-2S](2+) cluster in Asp1(371-920) was demonstrated by UV-visible absorption, resonance Raman spectroscopy, and electron paramagnetic resonance spectroscopy. We determined that this [2Fe-2S](2+) cluster is unlikely to participate in redox chemistry, since it rapidly degraded upon reduction by dithionite. Biochemical and mutagenic studies demonstrated that the [2Fe-2S](2+) cluster substantially inhibits the phosphatase activity of Asp1, thereby increasing its net kinase activity.

  17. Peripheral FAAH inhibition causes profound antinociception and protects against indomethacin-induced gastric lesions.

    PubMed

    Sasso, Oscar; Bertorelli, Rosalia; Bandiera, Tiziano; Scarpelli, Rita; Colombano, Giampiero; Armirotti, Andrea; Moreno-Sanz, Guillermo; Reggiani, Angelo; Piomelli, Daniele

    2012-05-01

    Fatty-acid amide hydrolase (FAAH) catalyzes the intracellular hydrolysis of the endocannabinoid anandamide and other bioactive lipid amides. In the present study, we conducted a comparative characterization of the effects of the newly identified brain-impermeant FAAH inhibitor, URB937 ([3-(3-carbamoylphenyl)-4-hydroxy-phenyl] N-cyclohexylcarbamate), in various rodent models of acute and persistent pain. When administered by the oral route in mice, URB937 was highly active (median effective dose, ED(50), to inhibit liver FAAH activity: 0.3mgkg(-1)) and had a bioavailability of 5.3%. The antinociceptive effects of oral URB937 were investigated in mouse models of acute inflammation (carrageenan), peripheral nerve injury (chronic sciatic nerve ligation) and arthritis (complete Freund's adjuvant). In all models, URB937 was as effective or more effective than standard analgesic and anti-inflammatory drugs (indomethacin, gabapentin, dexamethasone) and reversed pain-related responses (mechanical hyperalgesia, thermal hyperalgesia, and mechanical allodynia) in a dose-dependent manner. ED(50) values ranged from 0.2 to 10mgkg(-1), depending on model and readout. Importantly, URB937 was significantly more effective than two global FAAH inhibitors, URB597 and PF-04457845, in the complete Freund's adjuvant model. The effects of a combination of URB937 with the non-steroidal anti-inflammatory agent, indomethacin, were examined in the carrageenan and chronic sciatic nerve ligation models. Isobolographic analyses showed that the two compounds interacted synergistically to attenuate pain-related behaviors. Furthermore, URB937 reduced the number and severity of gastric lesions produced by indomethacin, while exerting no ulcerogenic effect when administered alone. The results indicate that the peripheral FAAH inhibitor URB937 is more effective than globally active FAAH inhibitors at inhibiting inflammatory pain. Our findings further suggest that FAAH and cyclooxygenase inhibitors

  18. Pharmacological inhibition of myostatin protects against skeletal muscle atrophy and weakness after anterior cruciate ligament tear.

    PubMed

    Wurtzel, Caroline Nw; Gumucio, Jonathan P; Grekin, Jeremy A; Khouri, Roger K; Russell, Alan J; Bedi, Asheesh; Mendias, Christopher L

    2017-02-08

    Anterior cruciate ligament (ACL) tears are among the most frequent knee injuries in sports medicine, with tear rates in the US up to 250,000 per year. Many patients who suffer from ACL tears have persistent atrophy and weakness even after considerable rehabilitation. Myostatin is a cytokine that directly induces muscle atrophy, and previous studies rodent models and patients have demonstrated an upregulation of myostatin after ACL tear. Using a preclinical rat model, our objective was to determine if the use of a bioneutralizing antibody against myostatin could prevent muscle atrophy and weakness after ACL tear. Rats underwent a surgically induced ACL tear and were treated with either a bioneutralizing antibody against myostatin (10B3, GlaxoSmithKline) or a sham antibody (E1-82.15, GlaxoSmithKline). Muscles were harvested at either 7 or 21 days after induction of a tear to measure changes in contractile function, fiber size, and genes involved in muscle atrophy and hypertrophy. These time points were selected to evaluate early and later changes in muscle structure and function. Compared to the sham antibody group, 7 days after ACL tear, myostatin inhibition reduced the expression of proteolytic genes and induced the expression of hypertrophy genes. These early changes in gene expression lead to a 22% increase in muscle fiber cross-sectional area and a 10% improvement in maximum isometric force production that were observed 21 days after ACL tear. Overall, myostatin inhibition lead to several favorable, although modest, changes in molecular biomarkers of muscle regeneration and reduced muscle atrophy and weakness following ACL tear. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  19. Coenzyme Q10 Protects Astrocytes from ROS-Induced Damage through Inhibition of Mitochondria-Mediated Cell Death Pathway

    PubMed Central

    Jing, Li; He, Mao-Tao; Chang, Yue; Mehta, Suresh L.; He, Qing-Ping; Zhang, Jian-Zhong; Li, P. Andy

    2015-01-01

    Coenzyme Q10 (CoQ10) acts by scavenging reactive oxygen species to protect neuronal cells against oxidative stress in neurodegenerative diseases. The present study was designed to examine whether CoQ10 was capable of protecting astrocytes from reactive oxygen species (ROS) mediated damage. For this purpose, ultraviolet B (UVB) irradiation was used as a tool to induce ROS stress to cultured astrocytes. The cells were treated with 10 and 25 μg/ml of CoQ10 for 3 or 24 h prior to the cells being exposed to UVB irradiation and maintained for 24 h post UVB exposure. Cell viability was assessed by MTT conversion assay. Mitochondrial respiration was assessed by respirometer. While superoxide production and mitochondrial membrane potential were measured using fluorescent probes, levels of cytochrome C (cyto-c), cleaved caspase-9, and caspase-8 were detected using Western blotting and/or immunocytochemistry. The results showed that UVB irradiation decreased cell viability and this damaging effect was associated with superoxide accumulation, mitochondrial membrane potential hyperpolarization, mitochondrial respiration suppression, cyto-c release, and the activation of both caspase-9 and -8. Treatment with CoQ10 at two different concentrations started 24 h before UVB exposure significantly increased the cell viability. The protective effect of CoQ10 was associated with reduction in superoxide, normalization of mitochondrial membrane potential, improvement of mitochondrial respiration, inhibition of cyto-c release, suppression of caspase-9. Furthermore, CoQ10 enhanced mitochondrial biogenesis. It is concluded that CoQ10 may protect astrocytes through suppression of oxidative stress, prevention of mitochondrial dysfunction, blockade of mitochondria-mediated cell death pathway, and enhancement of mitochondrial biogenesis. PMID:25552930

  20. CD98hc (SLC3A2) Loss Protects Against Ras-Driven Tumorigenesis by Modulating Integrin-Mediated Mechanotransduction

    PubMed Central

    Estrach, Soline; Lee, Sin-Ae; Boulter, Etienne; Pisano, Sabrina; Errante, Aurélia; Tissot, Floriane S.; Cailleteau, Laurence; Pons, Catherine; Ginsberg, Mark H.; Féral, Chloé C.

    2016-01-01

    CD98hc (SLC3A2) is the heavy chain component of the dimeric transmembrane glycoprotein CD98, which comprises the large neutral amino acid transporter LAT1 (SLC7A5) in cells. Overexpression of CD98hc occurs widely in cancer cells, and is associated with poor prognosis clinically, but its exact contributions to tumorigenesis are uncertain. In this study, we showed that that genetic deficiency of CD98hc protects against Ras-driven skin carcinogenesis. Deleting CD98hc after tumor induction was also sufficient to cause regression of existing tumors. Investigations into the basis for these effects defined two new functions of CD98hc that contribute to epithelial cancer beyond an intrinsic effect on CD98hc on tumor cell proliferation. First, CD98hc increased the stiffness of the tumor microenvironment. Second, CD98hc amplified the capacity of cells to respond to matrix rigidity, an essential factor in tumor development. Mechanistically, CD98hc mediated this stiffness-sensing by increasing Rho kinase (ROCK) activity, resulting in increased transcription mediated by YAP/TAZ, a nuclear relay for mechanical signals. Our results suggest that CD98hc contributes to carcinogenesis by amplifying a positive feedback loop which increases both extracellular matrix stiffness and resulting cellular responses. This work supports a rationale to explore the use of CD98hc inhibitors as cancer therapeutics, PMID:25267066

  1. Annual progress report on the development of a 2 MW/10 second battery energy storage system for power disturbance protection

    SciTech Connect

    1996-01-29

    Sandia National Laboratories (SNL), acting for the US Department of Energy (DOE), contracts for and administers programs for the purpose of promoting the development and commercialization of large scale, transportable battery energy storage systems. Under DOE Co-Op Agreement No. DE-FC04-94AL99852, SNL has contracted for the development and delivery of an initial prototype 250 kW bridge that becomes an integral subsystem of a 2 MW/10 Second System that can be used by utility customers to protect power sensitive equipment from power disturbances. Development work includes field installation and testing of the prototype unit at a participating utility site for extended product testing with subsequent relocation to an industrial or commercial participating utility customer site for additional evaluation. The program described by the referenced document calls for cost sharing with the successful bidder and eventual title transfer to the participating utility. Prototype delivery is scheduled for January of 1996, with a period of two years allowed for field testing. A final report summarizing the test data with conclusions and recommendations is part of the contract.

  2. Inhibiting an Epoxide Hydrolase Virulence Factor from Pseudomonas aeruginosa Protects CFTR.

    PubMed

    Bahl, Christopher D; Hvorecny, Kelli L; Bomberger, Jennifer M; Stanton, Bruce A; Hammock, Bruce D; Morisseau, Christophe; Madden, Dean R

    2015-08-17

    Opportunistic pathogens exploit diverse strategies to sabotage host defenses. Pseudomonas aeruginosa secretes the CFTR inhibitory factor Cif and thus triggers loss of CFTR, an ion channel required for airway mucociliary defense. However, the mechanism of action of Cif has remained unclear. It catalyzes epoxide hydrolysis, but there is no known role for natural epoxides in CFTR regulation. It was demonstrated that the hydrolase activity of Cif is strictly required for its effects on CFTR. A small-molecule inhibitor that protects this key component of the mucociliary defense system was also uncovered. These results provide a basis for targeting the distinctive virulence chemistry of Cif and suggest an unanticipated role of physiological epoxides in intracellular protein trafficking.

  3. Ischemic preconditioning protects the brain against injury via inhibiting CaMKII-nNOS signaling pathway.

    PubMed

    Wang, Mei; Qi, Da-Shi; Zhou, Cui; Han, Dong; Li, Pei-Pei; Zhang, Fang; Zhou, Xiao-Yan; Han, Meng; Di, Jie-Hui; Ye, Jun-Song; Yu, Hong-Min; Song, Yuan-Jian; Zhang, Guang-Yi

    2016-03-01

    Although studies have shown that cerebral ischemic preconditioning (IPC) can ameliorate ischemia/reperfusion (I/R) induced brain damage, but its precise mechanisms remain unknown. Therefore, the aim of this study was to investigate the neuroprotective mechanisms of IPC against ischemic brain damage induced by cerebral I/R and to explore whether the Calcium/calmodulin-dependent protein kinase II (CaMKII)-mediated up-regulation of nNOS ser847-phosphorylation signaling pathway contributed to the protection provided by IPC. Transient global brain ischemia was induced by 4-vessel occlusion in adult male Sprague-Dawley rats. The rats were pretreated with 3 min of IPC alone or KN62 (selective antagonist of CaMKII) treatment before IPC, after reperfusion for 3 days, 6 min ischemia was induced. Cresyl violet staining was used to examine the survival of hippocampal CA1 pyramidal neurons. Immunoblotting was performed to measure the phosphorylation of CaMKII, nNOS, c-Jun and the expression of FasL. Immunoprecipitation was used to examine the binding between PSD95 and nNOS. The results showed that IPC could significantly protect neurons against cerebral I/R injury, furthermore, the combination of PSD95 and nNOS was increased, coinstantaneously the phosphorylation of CaMKII and nNOS (ser847) were up-regulated, however the activation of c-Jun and FasL were reduced. Conversely, KN62 treatment before IPC reversed all these effects of IPC. Taken together, the results suggest that IPC could diminish ischemic brain injury through CaMKII-mediated up-regulation of nNOS ser847-phosphorylation signaling pathway.

  4. Syzygium cumini leaf extract inhibits LDL oxidation, but does not protect the liproprotein from glycation.

    PubMed

    Dos Santos, Matheus M; Prestes, Alessandro S; de Macedo, Gabriel T; Ecker, Assis; Barcelos, Rômulo P; Boligon, Aline A; Souza, Diego; de Bem, Andreza F; da Rocha, João B T; Barbosa, Nilda V

    2017-08-26

    Syzygium cumini (L.) Skeels is a plant widely used in folk medicine to treat diabetes mellitus (DM). The tea from its leaves is frequently used by diabetics for lowering hyperglycemia. There is a close relationship between DM and atherosclerosis, a chronic immuno-inflammatory disease, were the early stages encompass oxidative and glycative modifications in the structure of low density lipoprotein (LDL). To investigate the potential protective effects of aqueous-leaf extract from Syzygium cumini (S.cExt) against CuSO4-induced oxidation and methylglyoxal (MG)-induced glycation of human LDL in vitro. LDL oxidative changes were evaluated by measuring conjugated dienes (CD) formation, thiobarbituric acid reactive substances (TBARS) levels, quenching of tryptophan (Trp) fluorescence and structural modifications in LDL particle. In LDL glycated by MG (glyLDL), we determined the levels of fluorescent advanced glycation end products (AGEs) and mobility by agarose gel electrophoresis. S.cExt blocked oxidative events induced by CuSO4 in human LDL, plasma and serum. Fourier transform infrared spectroscopy (FT-IR) revealed that specific regions of apoB100 were oxidized by CuSO4 in human LDL and that S.cExt reduced these oxidations. Unlike, the increased AGEs levels and eletrophoretic mobility observed in LDL MG-glycated were not modified by S.cExt. The findings herein indicate that S.cExt could be tested in atherogenesis models as potential protective agent against LDL oxidation. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Triptolide, a Chinese herbal extract, protects dopaminergic neurons from inflammation-mediated damage through inhibition of microglial activation.

    PubMed

    Li, Feng-Qiao; Lu, Xiu-Zhi; Liang, Xi-Bin; Zhou, Hui-Fang; Xue, Bing; Liu, Xian-Yu; Niu, Dong-Bin; Han, Ji-Sheng; Wang, Xiao-Min

    2004-03-01

    Mounting lines of evidence have suggested that brain inflammation participates in the pathogenesis of Parkinson's disease. Triptolide is one of the major active components of Chinese herb Tripterygium wilfordii Hook F, which possesses potent anti-inflammatory and immunosuppressive properties. We found that triptolide concentration-dependently attenuated the lipopolysaccharide (LPS)-induced decrease in [3H]dopamine uptake and loss of tyrosine hydroxylase-immunoreactive neurons in primary mesencephalic neuron/glia mixed culture. Triptolide also blocked LPS-induced activation of microglia and excessive production of TNFalpha and NO. Our data suggests that triptolide may protect dopaminergic neurons from LPS-induced injury and its efficiency in inhibiting microglia activation may underlie the mechanism.

  6. Cystathionine γ-lyase protects vascular endothelium: a role for inhibition of histone deacetylase 6.

    PubMed

    Leucker, Thorsten M; Nomura, Yohei; Kim, Jae Hyung; Bhatta, Anil; Wang, Victor; Wecker, Andrea; Jandu, Sandeep; Santhanam, Lakshmi; Berkowitz, Dan; Romer, Lewis; Pandey, Deepesh

    2017-04-01

    Endothelial cystathionine γ-lyase (CSEγ) contributes to cardiovascular homeostasis, mainly through production of H2S. However, the molecular mechanisms that control CSEγ gene expression in the endothelium during cardiovascular diseases are unclear. The aim of the current study is to determine the role of specific histone deacetylases (HDACs) in the regulation of endothelial CSEγ. Reduced CSEγ mRNA expression and protein abundance were observed in human aortic endothelial cells (HAEC) exposed to oxidized LDL (OxLDL) and in aortas from atherogenic apolipoprotein E knockout (ApoE(-/-)) mice fed a high-fat diet compared with controls. Intact murine aortic rings exposed to OxLDL (50 μg/ml) for 24 h exhibited impaired endothelium-dependent vasorelaxation that was blocked by CSEγ overexpression or the H2S donor NaHS. CSEγ expression was upregulated by pan-HDAC inhibitors and by class II-specific HDAC inhibitors, but not by other class-specific inhibitors. The HDAC6 selective inhibitor tubacin and HDAC6-specific siRNA increased CSEγ expression and blocked OxLDL-mediated reductions in endothelial CSEγ expression and CSEγ promoter activity, indicating that HDAC6 is a specific regulator of CSEγ expression. Consistent with this finding, HDAC6 mRNA, protein expression, and activity were upregulated in OxLDL-exposed HAEC, but not in human aortic smooth muscle cells. HDAC6 protein levels in aortas from high-fat diet-fed ApoE(-/-) mice were comparable to those in controls, whereas HDAC6 activity was robustly upregulated. Together, our findings indicate that HDAC6 is upregulated by atherogenic stimuli via posttranslational modifications and is a critical regulator of CSEγ expression in vascular endothelium. Inhibition of HDAC6 activity may improve endothelial function and prevent or reverse the development of atherosclerosis.NEW & NOTEWORTHY Oxidative injury to endothelial cells by oxidized LDL reduced cystathionine γ-lyase (CSEγ) expression and H2S production

  7. Protective Effect of Thymoquinone against Cyclophosphamide-Induced Hemorrhagic Cystitis through Inhibiting DNA Damage and Upregulation of Nrf2 Expression

    PubMed Central

    Gore, Prashant R.; Prajapati, Chaitali P.; Mahajan, Umesh B.; Goyal, Sameer N.; Belemkar, Sateesh; Ojha, Shreesh; Patil, Chandragouda R.

    2016-01-01

    Cyclophosphamide (CYP) induced hemorrhagic cystitis is a dose-limiting side effect involving increased oxidative stress, inflammatory cytokines and suppressed activity of nuclear factor related erythroid 2-related factor (Nrf2). Thymoquinone (TQ), an active constituent of Nigella sativa seeds, is reported to increase the expression of Nrf2, exert antioxidant action, and anti-inflammatory effects in the experimental animals. The present study was designed to explore the effects of TQ on CYP-induced hemorrhagic cystitis in Balb/c mice. Cystitis was induced by a single intraperitoneal injection of CYP (200 mg/kg). TQ was administered intraperitoneally at 5, 10 and 20 mg/kg doses twice a day, for three days before and three days after the CYP administration. The efficacy of TQ was determined in terms of the protection against the CYP-induced histological perturbations in the bladder tissue, reduction in the oxidative stress, and inhibition of the DNA fragmentation. Immunohistochemistry was performed to examine the expression of Nrf2. TQ protected against CYP-induced oxidative stress was evident from significant reduction in the lipid peroxidation, restoration of the levels of reduced glutathione, catalase and superoxide dismutase activities. TQ treatment significantly reduced the DNA damage evident as reduced DNA fragmentation. A significant decrease in the cellular infiltration, edema, epithelial denudation and hemorrhage were observed in the histological observations. There was restoration and rise in the Nrf2 expression in the bladder tissues of mice treated with TQ. These results confirm that, TQ ameliorates the CYP-induced hemorrhagic cystitis in mice through reduction in the oxidative stress, inhibition of the DNA damage and through increased expression of Nrf2 in the bladder tissues. PMID:27489498

  8. Selective inhibition of 12-lipoxygenase protects islets and beta cells from inflammatory cytokine-mediated beta cell dysfunction.

    PubMed

    Taylor-Fishwick, David A; Weaver, Jessica; Glenn, Lindsey; Kuhn, Norine; Rai, Ganesha; Jadhav, Ajit; Simeonov, Anton; Dudda, Angela; Schmoll, Dieter; Holman, Theodore R; Maloney, David J; Nadler, Jerry L

    2015-03-01

    Islet inflammation leads to loss of functional pancreatic beta cell mass. Increasing evidence suggests that activation of 12-lipoxygenase leads to inflammatory beta cell loss. This study evaluates new specific small-molecule inhibitors of 12-lipoxygenase for protecting rodent and human beta cells from inflammatory damage. Mouse beta cell lines and mouse and human islets were treated with inflammatory cytokines IL-1β, TNFα and IFNγ in the absence or presence of novel selective 12-lipoxygenase inhibitors. Glucose-stimulated insulin secretion (GSIS), gene expression, cell survival and 12-S-hydroxyeicosatetraenoic acid (12-S-HETE) levels were evaluated using established methods. Pharmacokinetic analysis was performed with the lead inhibitor in CD1 mice. Inflammatory cytokines led to the loss of human beta cell function, elevated cell death, increased inflammatory gene expression and upregulation of 12-lipoxygenase expression and activity (measured by 12-S-HETE generation). Two 12-lipoxygenase inhibitors, Compounds 5 and 9, produced a concentration-dependent reduction of stimulated 12-S-HETE levels. GSIS was preserved in the presence of the 12-lipoxygenase inhibitors. 12-Lipoxygenase inhibition preserved survival of primary mouse and human islets. When administered orally, Compound 5 reduced plasma 12-S-HETE in CD1 mice. Compounds 5 and 9 preserved the function and survival of human donor islets exposed to inflammatory cytokines. Selective inhibition of 12-lipoxygenase activity confers protection to beta cells during exposure to inflammatory cytokines. These concept validation studies identify 12-lipoxygenase as a promising target in the prevention of loss of functional beta cells in diabetes.

  9. Radiofrequency Renal Denervation Protects the Ischemic Heart via Inhibition of GRK2 and Increased Nitric Oxide Signaling

    PubMed Central

    Polhemus, David J.; Gao, Juan; Scarborough, Amy L.; Trivedi, Rishi; McDonough, Kathleen H.; Goodchild, Traci T.; Smart, Frank

    2016-01-01

    Rationale: Catheter-based renal denervation (RDN) is currently under development for the treatment of resistant hypertension and is thought to reduce blood pressure via interruption of sympathetic pathways that modulate cardiovascular function. The sympathetic nervous system also plays a critical role in the pathogenesis of acute myocardial infarction and heart failure. Objective: We examined whether treatment with radiofrequency (RF)-RDN would protect the heart against subsequent myocardial ischemia/reperfusion injury via direct effects on the myocardium. Methods and Results: Spontaneously hypertensive rats received either bilateral RF-RDN or sham-RDN. At 4 weeks after RF-RDN (n=14) or sham-RDN (n=14) treatment, spontaneously hypertensive rats were subjected to 30 minutes of transient coronary artery occlusion and 24 hours –7 days reperfusion. Four weeks after RF-RDN, myocardial oxidative stress was markedly attenuated, and transcription and translation of antioxidants, superoxide dismutase 1 and glutathione peroxidase-1, were significantly upregulated compared with sham-RDN spontaneously hypertensive rats. RF-RDN also inhibited myocardial G protein–coupled receptor kinase 2 pathological signaling and enhanced myocardial endothelial nitric oxide synthase function and nitric oxide signaling. RF-RDN therapy resulted in a significant reduction in myocardial infarct size per area at risk compared with sham-RDN (26.8 versus 43.9%; P<0.01) at 24 hours postreperfusion and significantly improved left ventricular function at 7 days after myocardial ischemia/reperfusion. Conclusions: RF-RDN reduced oxidative stress, inhibited G protein–coupled receptor kinase 2 signaling, increased nitric oxide bioavailability, and ameliorated myocardial reperfusion injury in the setting of severe hypertension. These findings provide new insights into the remote cardioprotective effects of RF-RDN acting directly on cardiac myocytes to attenuate cell death and protect against ischemic

  10. The Protective Effect of Aucubin from Eucommia ulmoides Against Status Epilepticus by Inducing Autophagy and Inhibiting Necroptosis.

    PubMed

    Wang, Jin; Li, Ying; Huang, Wei-Hua; Zeng, Xiang-Chang; Li, Xiao-Hui; Li, Jian; Zhou, Jun; Xiao, Jian; Xiao, Bo; Ouyang, Dong-Sheng; Hu, Kai

    2017-04-07

    Eucommia ulmoides Oliv. is a famous traditional Chinese medicine which exhibits anti-oxidative stress ability and neuro-protective effects. Aucubin is the predominant component of Eucommia ulmoides Oliv. Our present study is intended to investigate aucubin's potential protective effects on neurons against epilepsy in the hippocampus by establishing the lithium-pilocarpine induced status epilepticus (SE) rat model in vivo. Aucubin (at a low dose and a high dose of 5[Formula: see text]mg/kg and 10[Formula: see text]mg/kg, respectively) was administered through gavage for two weeks before lithium-pilocarpine injection. Rats were sacrificed at 4, 24 and 72[Formula: see text]h after SE induction. Pretreatment with both low-dose and high-dose aucubin significantly reduced the number of death neurons ([Formula: see text]) and increased the number of surviving neurons ([Formula: see text]) in DG, Hilus, CA1 and CA3 hippocampal regions post SE. Meanwhile, it significantly inhibited necroptosis proteins (MLKL and RIP-1) ([Formula: see text] or [Formula: see text]) and enhanced autophagy protein (Beclin-1 and LC3BII/LC3BI) prevalence in the hippocampus ([Formula: see text] or [Formula: see text]). In conclusion, aucubin appeared to ameliorate damages in lithium-pilocarpine induced SE in hippocampus, reduce the number of apoptotic neurons, and increased the number of survival neurons by inducing autophagy and inhibiting necroptosis. These original findings might provide an important basis for the further investigation of the therapeutic role of aucubin in treatment or prevention of epilepsy-related neuronal damages.

  11. Mdm2 inhibition confers protection of p53-proficient cells from the cytotoxic effects of Wee1 inhibitors.

    PubMed

    Li, Yizhu; Saini, Priyanka; Sriraman, Anusha; Dobbelstein, Matthias

    2015-10-20

    Pharmacological inhibition of the cell cycle regulatory kinase Wee1 represents a promising strategy to eliminate cancer cells. Wee1 inhibitors cooperate with chemotherapeutics, e. g. nucleoside analogues, pushing malignant cells from S phase towards premature mitosis and death. However, considerable toxicities are observed in preclinical and clinical trials. A high proportion of tumor cells can be distinguished from all other cells of a patient's body by inactivating mutations in the tumor suppressor p53. Here we set out to develop an approach for the selective protection of p53-proficient cells against the cytotoxic effects of Wee1 inhibitors. We pretreated such cells with Nutlin-3a, a prototype inhibitor of the p53-antagonist Mdm2. The resulting transient cell cycle arrest effectively increased the survival of cells that were subsequently treated with combinations of the Wee1 inhibitor MK-1775 and/or the nucleoside analogue gemcitabine. In this constellation, Nutlin-3a reduced caspase activation and diminished the phosphorylation of Histone 2AX, an indicator of the DNA damage response. Both effects were strictly dependent on the presence of p53. Moreover, Nutlin pre-treatment reduced the fraction of cells that were undergoing premature mitosis in response to Wee1 inhibition. We conclude that the pre-activation of p53 through Mdm2 antagonists serves as a viable option to selectively protect p53-proficient cells against the cytotoxic effects of Wee1 inhibitors, especially when combined with a nucleoside analogue. Thus, Mdm2 antagonists might prove useful to avoid unwanted side effects of Wee1 inhibitors. On the other hand, when a tumor contains wild type p53, care should be taken not to induce its activity before applying Wee1 inhibitors.

  12. Inhibition of Na(+)/H(+) isoform-1 exchange protects hearts perfused after 6-hour cardioplegic cold storage.

    PubMed

    Stowe, David F; Heisner, James S; An, Jianzhong; Camara, Amadou; Varadarajan, Srinivasan G; Novalija, Enis; Chen, Qun; Schelling, Pierre

    2002-03-01

    Cardiac ischemia-reperfusion activates Na(+)/H(+) exchange; excess Na(+) and the resulting Ca(2+) overload, through reverse Na(+)/Ca(2+) exchange, cause cellular injury and cardiac dysfunction. We postulated that inhibiting the Na(+)/H(+) isoform-1 exchanger would add to the protection of hearts after long-term cold storage in acidic cardioplegic solution. Guinea pig hearts were isolated and perfused at 37 degrees C with Krebs-Ringer's solution (KRS) and then switched to an acidic St. Thomas solution (STS) at 25 degrees C. Perfusion was stopped at 10 degrees C, and hearts were stored for 6 hours in STS at 3.4 degrees C. On reperfusion to 25 degrees C, hearts were perfused with KRS for 60 minutes. Hearts were divided into 4 groups: sham control (SHAM); eniporide (EPR, EMD96785) IV, 1 mg/kg given IV over 15 minutes before heart isolation; EPR intracoronary, 1 micromol/liter in STS given intracoronary after heart isolation; and EPR IV and intracoronary. Values at 60 minutes reperfusion (the percentage of control [100%] before cold storage) are given, respectively, for EPR IV, EPR intracoronary, and EPR IV and intracoronary vs drug-free SHAM (SEM, *p < 0.05 vs SHAM): 72% +/- 3%*, 65% +/- 3%*, and 81% +/- 2%* vs 55% +/- 3% for left ventricular pressure; 94% +/- 3%*, 96% +/- 5%*, and 102% +/- 2%* vs 81% +/- 3% for coronary flow; 60% +/- 2%, 58% +/- 3%, and 74%* +/- 3% vs 58% +/- 4% for cardiac efficiency; 106% +/- 2%*, 108% +/- 3%*, and 107% +/- 2%* vs 116% +/- 4% for percentage of O(2) extraction. Infarct size as percentage of ventricular weight was 20% +/- 3%*, 31% +/- 3%, and 6% +/- 2%* vs 35% +/- 3% (SHAM) after 60 minutes of reperfusion. Na(+)/H(+) isoform-1 exchanger inhibition, particularly if given IV before storage and intracoronary during cooling and rewarming, adds to the protection of cardioplegic solutions.

  13. Cinnamaldehyde Inhibits Staphylococcus aureus Virulence Factors and Protects against Infection in a Galleria mellonella Model

    PubMed Central

    Ferro, Thiago A. F.; Araújo, Jéssica M. M.; dos Santos Pinto, Bruna L.; dos Santos, Jéssica S.; Souza, Eliene B.; da Silva, Bruna L. R.; Colares, Valderlane L. P.; Novais, Tânia M. G.; Filho, Clovis M. B.; Struve, Carsten; Calixto, João B.; Monteiro-Neto, Valério; da Silva, Luís C. N.; Fernandes, Elizabeth S.

    2016-01-01

    Bacterial resistance to the available marketed drugs has prompted the search of novel therapies; especially in regards of anti-virulence strategies that aim to make bacteria less pathogenic and/or decrease their probability to become resistant to therapy. Cinnamaldehyde is widely known for its antibacterial properties through mechanisms that include the interaction of this compound with bacterial cell walls. However, only a handful of studies have addressed its effects on bacterial virulence, especially when tested at sub-inhibitory concentrations. Herein, we show for the first time that cinnamaldehyde is bactericidal against Staphylococcus aureus and Enterococcus faecalis multidrug resistant strains and does not promote bacterial tolerance. Cinnamaldehyde actions were stronger on S. aureus as it was able to inhibit its hemolytic activity on human erythrocytes and reduce its adherence to latex. Furthermore, cinnamaldehyde enhanced the serum-dependent lysis of S. aureus. In vivo testing of cinnamaldehyde in Galleria mellonella larvae infected with S. aureus, showed this compound improves larvae survival whilst diminishing bacterial load in their hemolymph. We suggest that cinnamaldehyde may represent an alternative therapy to control S. aureus-induced bacterial infections as it presents the ability to reduce bacterial virulence/survival without promoting an adaptive phenotype. PMID:28066373

  14. C-phycocyanin protects against low fertility by inhibiting reactive oxygen species in aging mice

    PubMed Central

    Li, Yan-Jiao; Han, Zhe; Ge, Lei; Zhou, Cheng-Jie; Zhao, Yue-Fang; Wang, Dong-Hui; Ren, Jing; Niu, Xin-Xin; Liang, Cheng-Guang

    2016-01-01

    Women over 35 have higher rates of infertility, largely due to deterioration of oocyte quality characterized by fragmentation, abnormal meiotic spindle-chromosome complexes, and oxidative stress. C-phycocyanin (PC) is a biliprotein enriched in Spirulina platensis that is known to possess antioxidant, anti-inflammatory, and radical-scavenging properties. D-galactose-induced aging acceleration in mice has been extensively used to study aging mechanisms and for pharmaceutical screening. In this study, adult female B6D2F/1 mice injected with D-galactose were used as a model to test the age-reversing effects of PC on degenerated reproductive ability. Our results show that PC can prevent oocyte fragmentation and aneuploidy by maintaining cytoskeletal integrity. Moreover, PC can reverse the expression of antioxidant genes, increase superoxide dismutase (SOD) activity and decrease methane dicarboxylic aldehyde (MDA) content, and normalize mitochondria distribution. PC exerts its benefit by inhibiting reactive oxygen species (ROS) production, which decreases apoptosis. Finally, we observe a significant increase in litter size after PC administration to D-galactose-induced aging mice. Our study demonstrates for the first time that D-galactose-induced impaired female reproductive capability can be partially rescued by the antioxidant effects of PC. PMID:27008700

  15. SIRT4 overexpression protects against diabetic nephropathy by inhibiting podocyte apoptosis

    PubMed Central

    Shi, Jian-Xia; Wang, Qi-Jin; Li, Hui; Huang, Qin

    2017-01-01

    Diabetic nephropathy is a diabetic complication associated with capillary damage and increased mortality. Sirtuin 4 (SIRT4) plays an important role in mitochondrial function and the pathogenesis of metabolic diseases, including aging kidneys. The aim of the present study was to investigate the association between SIRT4 and diabetic nephropathy in a glucose-induced mouse podocyte model. A CCK-8 assay showed that glucose simulation significantly inhibited podocyte proliferation in a time- and concentration-dependent manner. Reverse transcription-quantitative polymerase chain reaction and western blot analysis showed that the mRNA and protein levels of SIRT4 were notably decreased in a concentration-dependent manner in glucose-simulated podocytes. However, SIRT4 overexpression increased proliferation and suppressed apoptosis, which was accompanied by increases in mitochondrial membrane potential and reduced production of reactive oxygen species (ROS). Notably, SIRT4 overexpression downregulated the expression of apoptosis-related proteins NOX1, Bax and phosphorylated p38 and upregulated the expression of Bcl-2 in glucose-simulated podocytes. In addition, SIRT4 overexpression significantly attenuated the inflammatory response, indicated by reductions in the levels of TNF-α, IL-1β and IL-6. These results demonstrate for the first time that the overexpression of SIRT4 prevents glucose-induced podocyte apoptosis and ROS production and suggest that podocyte apoptosis represents an early pathological mechanism leading to diabetic nephropathy. PMID:28123512

  16. Inhibition of cytoskeletal protein carbonylation may protect against oxidative damage in traumatic brain injury

    PubMed Central

    Zhang, Qiusheng; Zhang, Meng; Huang, Xianjian; Liu, Xiaojia; Li, Weiping

    2016-01-01

    Oxidative stress is the principal factor in traumatic brain injury (TBI) that initiates protracted neuronal dysfunction and remodeling. Cytoskeletal proteins are known to be carbonylated under oxidative stress; however, the complex molecular and cellular mechanisms of cytoskeletal protein carbonylation remain poorly understood. In the present study, the expression levels of glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) were investigated in PC12 cells treated with H2O2. Western blot analysis was used to monitor the carbonylation levels of β-actin and β-tubulin. The results indicated that oxidative stress was increased in PC12 cells that were treated with H2O2 for 24 or 48 h. In addition, increased carbonylation levels of β-actin and β-tubulin were detected in H2O2-treated cells. However, these carbonylation levels were reduced by pretreatment with aminoguanidine, a type of reactive carbonyl species chelating agent, and a similar trend was observed following overexpression of proteasome β5 via transgenic technology. In conclusion, the present study results suggested that the development of TBI may cause carbonylation of cytoskeletal proteins, which would then undermine the stability of cytoskeletal proteins. Thus, the development of TBI may be improved via the inhibition of cytoskeletal protein carbonylation. PMID:28101189

  17. Valsartan protects HK-2 cells from contrast media-induced apoptosis by inhibiting endoplasmic reticulum stress.

    PubMed

    Peng, Ping-An; Wang, Le; Ma, Qian; Xin, Yi; Zhang, Ou; Han, Hong-Ya; Liu, Xiao-Li; Ji, Qing-Wei; Zhou, Yu-Jie; Zhao, Ying-Xin

    2015-12-01

    Contrast-induced acute kidney injury (CI-AKI) is associated with increasing in-hospital and long-term adverse clinical outcomes in high-risk patients undergoing percutaneous coronary intervention (PCI). Contrast media (CM)-induced renal tubular cell apoptosis is reported to participate in this process by activating endoplasmic reticulum (ER) stress. An angiotensin II type 1 receptor (AT1R) antagonist can alleviate ER stress-induced renal apoptosis in streptozotocin (STZ)-induced diabetic mice and can reduce CM-induced renal apoptosis by reducing oxidative stress and reversing the enhancement of bax mRNA and the reduction of bcl-2 mRNA, but the effect of the AT1R blocker on ER stress in the pathogenesis of CI-AKI is still unknown. In this study, we explored the effect of valsartan on meglumine diatrizoate-induced human renal tubular cell apoptosis by measuring changes in ER stress-related biomarkers. The results showed that meglumine diatrizoate caused significant cell apoptosis by up-regulating the expression of ER stress markers, including glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4), CCAAT/enhancer-binding protein-homologous protein (CHOP) and caspase 12, in a time- and dose-dependent manner, which could be alleviated by preincubation with valsartan. In conclusion, valsartan had a potential nephroprotective effect on meglumine diatrizoate-induced renal cell apoptosis by inhibiting ER stress.

  18. Cinnamaldehyde Inhibits Staphylococcus aureus Virulence Factors and Protects against Infection in a Galleria mellonella Model.

    PubMed

    Ferro, Thiago A F; Araújo, Jéssica M M; Dos Santos Pinto, Bruna L; Dos Santos, Jéssica S; Souza, Eliene B; da Silva, Bruna L R; Colares, Valderlane L P; Novais, Tânia M G; Filho, Clovis M B; Struve, Carsten; Calixto, João B; Monteiro-Neto, Valério; da Silva, Luís C N; Fernandes, Elizabeth S

    2016-01-01

    Bacterial resistance to the available marketed drugs has prompted the search of novel therapies; especially in regards of anti-virulence strategies that aim to make bacteria less pathogenic and/or decrease their probability to become resistant to therapy. Cinnamaldehyde is widely known for its antibacterial properties through mechanisms that include the interaction of this compound with bacterial cell walls. However, only a handful of studies have addressed its effects on bacterial virulence, especially when tested at sub-inhibitory concentrations. Herein, we show for the first time that cinnamaldehyde is bactericidal against Staphylococcus aureus and Enterococcus faecalis multidrug resistant strains and does not promote bacterial tolerance. Cinnamaldehyde actions were stronger on S. aureus as it was able to inhibit its hemolytic activity on human erythrocytes and reduce its adherence to latex. Furthermore, cinnamaldehyde enhanced the serum-dependent lysis of S. aureus. In vivo testing of cinnamaldehyde in Galleria mellonella larvae infected with S. aureus, showed this compound improves larvae survival whilst diminishing bacterial load in their hemolymph. We suggest that cinnamaldehyde may represent an alternative therapy to control S. aureus-induced bacterial infections as it presents the ability to reduce bacterial virulence/survival without promoting an adaptive phenotype.

  19. 5-HT2B Receptor Antagonists Inhibit Fibrosis and Protect from RV Heart Failure

    PubMed Central

    Janssen, Wiebke; Schymura, Yves; Novoyatleva, Tatyana; Luitel, Himal; Tretyn, Aleksandra; Pullamsetti, Soni Savai; Weissmann, Norbert; Seeger, Werner; Ghofrani, Hossein Ardeschir; Schermuly, Ralph Theo

    2015-01-01

    Objective. The serotonin (5-HT) pathway was shown to play a role in pulmonary hypertension (PH), but its functions in right ventricular failure (RVF) remain poorly understood. The aim of the current study was to investigate the effects of Terguride (5-HT2A and 2B receptor antagonist) or SB204741 (5-HT2B receptor antagonist) on right heart function and structure upon pulmonary artery banding (PAB) in mice. Methods. Seven days after PAB, mice were treated for 14 days with Terguride (0.2 mg/kg bid) or SB204741 (5 mg/kg day). Right heart function and remodeling were assessed by right heart catheterization, magnetic resonance imaging (MRI), and histomorphometric methods. Total secreted collagen content was determined in mouse cardiac fibroblasts isolated from RV tissues. Results. Chronic treatment with Terguride or SB204741 reduced right ventricular fibrosis and showed improved heart function in mice after PAB. Moreover, 5-HT2B receptor antagonists diminished TGF-beta1 induced collagen synthesis of RV cardiac fibroblasts in vitro. Conclusion. 5-HT2B receptor antagonists reduce collagen deposition, thereby inhibiting right ventricular fibrosis. Chronic treatment prevented the development and progression of pressure overload-induced RVF in mice. Thus, 5-HT2B receptor antagonists represent a valuable novel therapeutic approach for RVF. PMID:25667920

  20. Transforming growth factor β1 inhibition protects from noise-induced hearing loss

    PubMed Central

    Murillo-Cuesta, Silvia; Rodríguez-de la Rosa, Lourdes; Contreras, Julio; Celaya, Adelaida M.; Camarero, Guadalupe; Rivera, Teresa; Varela-Nieto, Isabel

    2015-01-01

    Excessive exposure to noise damages the principal cochlear structures leading to hearing impairment. Inflammatory and immune responses are central mechanisms in cochlear defensive response to noise but, if unregulated, they contribute to inner ear damage and hearing loss. Transforming growth factor β (TGF-β) is a key regulator of both responses and high levels of this factor have been associated with cochlear injury in hearing loss animal models. To evaluate the potential of targeting TGF-β as a therapeutic strategy for preventing or ameliorating noise-induced hearing loss (NIHL), we studied the auditory function, cochlear morphology, gene expression and oxidative stress markers in mice exposed to noise and treated with TGF-β1 peptidic inhibitors P17 and P144, just before or immediately after noise insult. Our results indicate that systemic administration of both peptides significantly improved both the evolution of hearing thresholds and the degenerative changes induced by noise-exposure in lateral wall structures. Moreover, treatments ameliorated the inflammatory state and redox balance. These therapeutic effects were dose-dependent and more effective if the TGF-β1 inhibitors were administered prior to inducing the injury. In conclusion, inhibition of TGF-β1 actions with antagonistic peptides represents a new, promising therapeutic strategy for the prevention and repair of noise-induced cochlear damage. PMID:25852546

  1. Inhibition of CDK4/6 protects against radiation-induced intestinal injury in mice

    PubMed Central

    Wei, Liang; Leibowitz, Brian J.; Wang, Xinwei; Epperly, Michael; Greenberger, Joel; Zhang, Lin

    2016-01-01

    Radiotherapy causes dose-limiting toxicity and long-term complications in rapidly renewing tissues, including the gastrointestinal tract. Currently, there is no FDA-approved agent for the prevention or treatment of radiation-induced intestinal injury. In this study, we have shown that PD 0332991 (PD), an FDA-approved selective inhibitor of cyclin-dependent kinase 4/6 (CDK4/6), prevents radiation-induced lethal intestinal injury in mice. Treating mice with PD or a structurally distinct CDK4/6 inhibitor prior to radiation blocked proliferation and crypt apoptosis and improved crypt regeneration. PD treatment also enhanced LGR5+ stem cell survival and regeneration after radiation. PD was an on-target inhibitor of RB phosphorylation and blocked G1/S transition in the intestinal crypts. PD treatment strongly but reversibly inhibited radiation-induced p53 activation, which blocked p53-upregulated modulator of apoptosis–dependent (PUMA-dependent) apoptosis without affecting p21-dependent suppression of DNA damage accumulation, with a repair bias toward nonhomologous end joining. Further, deletion of PUMA synergized with PD treatment for even greater intestinal radioprotection. Our results demonstrate that the cell cycle critically regulates the DNA damage response and survival of intestinal stem cells and support the concept that pharmacological quiescence is a potentially highly effective and selective strategy for intestinal radioprotection. PMID:27701148

  2. Inhibition of Drp1 hyper-activation is protective in animal models of experimental multiple sclerosis.

    PubMed

    Luo, Fucheng; Herrup, Karl; Qi, Xin; Yang, Yan

    2017-02-24

    Multiple Sclerosis (MS), a leading neurological disorder of young adults, is characterized by the loss of oligodendrocytes (OLs), demyelination, inflammation and neuronal degeneration. Here we show that dynamin-related protein 1 (Drp1), a mitochondrial fission protein, is activated in primary OL cells exposed to TNF-α induced inflammation or oxidative stress, as well as in EAE-immunized and cuprizone toxicity-induced demyelinating mouse models. Inhibition of Drp1 hyper-activation by the selective inhibitor P110 abolishes Drp1 translocation to the mitochondria, reduces mitochondrial fragmentation and stems necrosis in primary OLs exposed to TNF-α and H2O2. Notably, in both types of mouse models, treatment with P110 significantly reduces the loss of mature OLs and demyelination, attenuates the number of active microglial cells and astrocytes, yet has no effect on the differentiation of oligodendrocyte precursor cells. Drp1 activation appears to be mediated through the RIPK1/RIPK3/MLKL/PGAM5 pathway during TNF-α-induced oligodendroglia necroptosis. Our results demonstrate a critical role of Drp1 hyper-activation in OL cell death and suggest that an inhibitor of Drp1 hyper-activation such as P110 is worth exploring for its ability to halt or slow the progression of MS.

  3. p53 inhibition by the LANA protein of KSHV protects against cell death.

    PubMed

    Friborg, J; Kong, W; Hottiger, M O; Nabel, G J

    Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8, has been implicated in the development of Kaposi's sarcoma (KS) and several B-cell lymphoproliferative diseases. Most cells in lesions derived from these malignancies are latently infected, and different viral gene products have been identified in association with lytic or latent infection by KSHV. The latency-associated nuclear antigen (LANA), encoded by open reading frame 73 of the KSHV genome, is a highly immunogenic protein that is expressed predominantly during viral latency, in most KS spindle cells and in cell lines established from body-cavity-based lymphomas. Antibodies to LANA can be detected in a high percentage of HIV-infected individuals who subsequently develop KS, although its role in disease pathogenesis is not completely understood. p53 is a potent transcriptional regulator of cell growth whose induction leads either to cell-cycle arrest or apoptosis. Loss of p53 function correlates with cell transformation and oncogenesis, and several viral oncoproteins interact with p53 and modulate its biological activity. Here we show that LANA interacts with the tumour suppressor protein p53 and represses its transcriptional activity. This viral gene product further inhibits the ability of p53 to induce cell death. We propose that LANA contributes to viral persistence and oncogenesis in KS through its ability to promote cell survival by altering p53 function.

  4. C-phycocyanin protects against low fertility by inhibiting reactive oxygen species in aging mice.

    PubMed

    Li, Yan-Jiao; Han, Zhe; Ge, Lei; Zhou, Cheng-Jie; Zhao, Yue-Fang; Wang, Dong-Hui; Ren, Jing; Niu, Xin-Xin; Liang, Cheng-Guang

    2016-04-05

    Women over 35 have higher rates of infertility, largely due to deterioration of oocyte quality characterized by fragmentation, abnormal meiotic spindle-chromosome complexes, and oxidative stress. C-phycocyanin (PC) is a biliprotein enriched in Spirulina platensis that is known to possess antioxidant, anti-inflammatory, and radical-scavenging properties. D-galactose-induced aging acceleration in mice has been extensively used to study aging mechanisms and for pharmaceutical screening. In this study, adult female B6D2F/1 mice injected with D-galactose were used as a model to test the age-reversing effects of PC on degenerated reproductive ability. Our results show that PC can prevent oocyte fragmentation and aneuploidy by maintaining cytoskeletal integrity. Moreover, PC can reverse the expression of antioxidant genes, increase superoxide dismutase (SOD) activity and decrease methane dicarboxylic aldehyde (MDA) content, and normalize mitochondria distribution. PC exerts its benefit by inhibiting reactive oxygen species (ROS) production, which decreases apoptosis. Finally, we observe a significant increase in litter size after PC administration to D-galactose-induced aging mice. Our study demonstrates for the first time that D-galactose-induced impaired female reproductive capability can be partially rescued by the antioxidant effects of PC.

  5. Inhibition of insulin/IGF-1 receptor signaling protects from mitochondria-mediated kidney failure.

    PubMed

    Ising, Christina; Koehler, Sybille; Brähler, Sebastian; Merkwirth, Carsten; Höhne, Martin; Baris, Olivier R; Hagmann, Henning; Kann, Martin; Fabretti, Francesca; Dafinger, Claudia; Bloch, Wilhelm; Schermer, Bernhard; Linkermann, Andreas; Brüning, Jens C; Kurschat, Christine E; Müller, Roman-Ulrich; Wiesner, Rudolf J; Langer, Thomas; Benzing, Thomas; Brinkkoetter, Paul Thomas

    2015-03-01

    Mitochondrial dysfunction and alterations in energy metabolism have been implicated in a variety of human diseases. Mitochondrial fusion is essential for maintenance of mitochondrial function and requires the prohibitin ring complex subunit prohibitin-2 (PHB2) at the mitochondrial inner membrane. Here, we provide a link between PHB2 deficiency and hyperactive insulin/IGF-1 signaling. Deletion of PHB2 in podocytes of mice, terminally differentiated cells at the kidney filtration barrier, caused progressive proteinuria, kidney failure, and death of the animals and resulted in hyperphosphorylation of S6 ribosomal protein (S6RP), a known mediator of the mTOR signaling pathway. Inhibition of the insulin/IGF-1 signaling system through genetic deletion of the insulin receptor alone or in combination with the IGF-1 receptor or treatment with rapamycin prevented hyperphosphorylation of S6RP without affecting the mitochondrial structural defect, alleviated renal disease, and delayed the onset of kidney failure in PHB2-deficient animals. Evidently, perturbation of insulin/IGF-1 receptor signaling contributes to tissue damage in mitochondrial disease, which may allow therapeutic intervention against a wide spectrum of diseases. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

  6. Quercitrin offers protection against brain injury in mice by inhibiting oxidative stress and inflammation.

    PubMed

    Ma, Jie-Qiong; Luo, Rong-Zhen; Jiang, Hai-Xia; Liu, Chan-Min

    2016-01-01

    Quercitrin is one of the primary flavonoid compounds present in vegetables and fruits. The aim of the present study was to evaluate the effects of quercitrin against carbon tetrachloride (CCl4) induced brain injury and further to elucidate its probable mechanisms. ICR mice received CCl4 intraperitoneally with or without quercitrin co-administration for 4 weeks. Our data showed that quercitrin significantly suppressed the elevation of reactive oxygen species (ROS) production and malondialdehyde (MDA) content, reduced tissue plasminogen activator (t-PA) activity, enhanced the antioxidant enzyme activities and abrogated cytochrome P450 2E1 (CYP2E1) induction in mouse brains. Quercitrin also prevented CCl4 induced cerebral function disorders associated with its ability to inhibit the activities of monoamine oxidase (MAO), acetylcholine esterase (AChE) and the N-methyl-d-aspartate receptor 2B subunit (NR2B). In addition, western blot analysis showed that quercitrin suppressed the release of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). Taken together, our findings suggested that quercitrin may be a potential candidate to be developed as a neuroprotective agent.

  7. Rapamycin Protects from Type-I Peritoneal Membrane Failure Inhibiting the Angiogenesis, Lymphangiogenesis, and Endo-MT

    PubMed Central

    Aguirre, Anna Rita; Loureiro, Jesús; Abensur, Hugo; Sandoval, Pilar; Sánchez-Tomero, José Antonio; del Peso, Gloria; Jiménez-Heffernan, José Antonio; Ruiz-Carpio, Vicente; Selgas, Rafael; López-Cabrera, Manuel; Aguilera, Abelardo; Liappas, Georgios

    2015-01-01

    Preservation of peritoneal membrane (PM) is essential for long-term survival in peritoneal dialysis (PD). Continuous presence of PD fluids (PDF) in the peritoneal cavity generates chronic inflammation and promotes changes of the PM, such as fibrosis, angiogenesis, and lymphangiogenesis. Mesothelial-to-mesenchymal transition (MMT) and endothelial-to-mesenchymal transition (Endo-MT) seem to play a central role in this pathogenesis. We speculated that Rapamycin, a potent immunosuppressor, could be beneficial by regulating blood and lymphatic vessels proliferation. We demonstrate that mice undergoing a combined PD and Rapamycin treatment (PDF + Rapa group) presented a reduced PM thickness and lower number of submesothelial blood and lymphatic vessels, as well as decreased MMT and Endo-MT, comparing with their counterparts exposed to PD alone (PDF group). Peritoneal water transport in the PDF + Rapa group remained at control level, whereas PD effluent levels of VEGF, TGF-β, and TNF-α were lower than in the PDF group. Moreover, the treatment of mesothelial cells with Rapamycin in vitro significantly decreased VEGF synthesis and selectively inhibited the VEGF-C and VEGF-D release when compared with control cells. Thus, Rapamycin has a protective effect on PM in PD through an antifibrotic and antiproliferative effect on blood and lymphatic vessels. Moreover, it inhibits Endo-MT and, at least partially, MMT. PMID:26688823

  8. Rapamycin Protects from Type-I Peritoneal Membrane Failure Inhibiting the Angiogenesis, Lymphangiogenesis, and Endo-MT.

    PubMed

    González-Mateo, Guadalupe Tirma; Aguirre, Anna Rita; Loureiro, Jesús; Abensur, Hugo; Sandoval, Pilar; Sánchez-Tomero, José Antonio; del Peso, Gloria; Jiménez-Heffernan, José Antonio; Ruiz-Carpio, Vicente; Selgas, Rafael; López-Cabrera, Manuel; Aguilera, Abelardo; Liappas, Georgios

    2015-01-01

    Preservation of peritoneal membrane (PM) is essential for long-term survival in peritoneal dialysis (PD). Continuous presence of PD fluids (PDF) in the peritoneal cavity generates chronic inflammation and promotes changes of the PM, such as fibrosis, angiogenesis, and lymphangiogenesis. Mesothelial-to-mesenchymal transition (MMT) and endothelial-to-mesenchymal transition (Endo-MT) seem to play a central role in this pathogenesis. We speculated that Rapamycin, a potent immunosuppressor, could be beneficial by regulating blood and lymphatic vessels proliferation. We demonstrate that mice undergoing a combined PD and Rapamycin treatment (PDF + Rapa group) presented a reduced PM thickness and lower number of submesothelial blood and lymphatic vessels, as well as decreased MMT and Endo-MT, comparing with their counterparts exposed to PD alone (PDF group). Peritoneal water transport in the PDF + Rapa group remained at control level, whereas PD effluent levels of VEGF, TGF-β, and TNF-α were lower than in the PDF group. Moreover, the treatment of mesothelial cells with Rapamycin in vitro significantly decreased VEGF synthesis and selectively inhibited the VEGF-C and VEGF-D release when compared with control cells. Thus, Rapamycin has a protective effect on PM in PD through an antifibrotic and antiproliferative effect on blood and lymphatic vessels. Moreover, it inhibits Endo-MT and, at least partially, MMT.

  9. A cytosolic protein factor from the naked mole-rat activates proteasomes of other species and protects these from inhibition.

    PubMed

    Rodriguez, Karl A; Osmulski, Pawel A; Pierce, Anson; Weintraub, Susan T; Gaczynska, Maria; Buffenstein, Rochelle

    2014-11-01

    The naked mole-rat maintains robust proteostasis and high levels of proteasome-mediated proteolysis for most of its exceptional (~31years) life span. Here, we report that the highly active proteasome from the naked mole-rat liver resists attenuation by a diverse suite of proteasome-specific small molecule inhibitors. Moreover, mouse, human, and yeast proteasomes exposed to the proteasome-depleted, naked mole-rat cytosolic fractions, recapitulate the observed inhibition resistance, and mammalian proteasomes also show increased activity. Gel filtration coupled with mass spectrometry and atomic force microscopy indicates that these traits are supported by a protein factor that resides in the cytosol. This factor interacts with the proteasome and modulates its activity. Although Heat shock protein 72 kDa (HSP72) and Heat shock protein 40 kDa (Homolog of bacterial DNAJ1) (HSP40(Hdj1)) are among the constituents of this factor, the observed phenomenon, such as increasing peptidase activity and protecting against inhibition cannot be reconciled with any known chaperone functions. This novel function may contribute to the exceptional protein homeostasis in the naked mole-rat and allow it to successfully defy aging.

  10. Salmon-derived thrombin inhibits development of chronic pain through an endothelial barrier protective mechanism dependent on APC

    PubMed Central

    Smith, Jenell R; Galie, Peter A; Slochower, David R; Weisshaar, Christine L.; Janmey, Paul A; Winkelstein, Beth A

    2015-01-01

    Many neurological disorders are initiated by blood-brain barrier breakdown, which potentiates spinal neuroinflammation and neurodegeneration. Peripheral neuropathic injuries are known to disrupt the blood-spinal cord barrier (BSCB) and to potentiate inflammation. But, it is not known whether BSCB breakdown facilitates pain development. In this study, a neural compression model in the rat was used to evaluate relationships among BSCB permeability, inflammation and pain-related behaviors. BSCB permeability increases transiently only after injury that induces mechanical hyperalgesia, which correlates with serum concentrations of pro-inflammatory cytokines, IL-7, IL-12, IL-1α and TNF-α. Mammalian thrombin dually regulates vascular permeability through PAR1 and activated protein C (APC). Since thrombin protects vascular integrity through APC, directing its affinity towards protein C, while still promoting coagulation, might be an ideal treatment for BSCB-disrupting disorders. Salmon thrombin, which prevents the development of mechanical allodynia, also prevents BSCB breakdown after neural injury and actively inhibits TNF-α-induced endothelial permeability in vitro, which is not evident the case for human thrombin. Salmon thrombin’s production of APC faster than human thrombin is confirmed using a fluorogenic assay and APC is shown to inhibit BSCB breakdown and pain-related behaviors similar to salmon thrombin. Together, these studies highlight the impact of BSCB on pain and establish salmon thrombin as an effective blocker of BSCB, and resulting nociception, through its preferential affinity for protein C. PMID:26708087

  11. Propofol Protects Rats and Human Alveolar Epithelial Cells Against Lipopolysaccharide-Induced Acute Lung Injury via Inhibiting HMGB1 Expression.

    PubMed

    Wang, Xiaoyan; Liu, Chengxiao; Wang, Gongming

    2016-06-01

    High-mobility group box 1 (HMGB1) plays a key role in the development of acute lung injury (ALI). Propofol, a general anesthetic with anti-inflammatory properties, has been suggested to be able to modulate lipopolysaccharide (LPS)-induced ALI. In this study, we investigated the effects of propofol on the expression of HMGB1 in a rat model of LPS-induced ALI. Rats underwent intraperitoneal injection of LPS to mimic sepsis-induced ALI. Propofol bolus (1, 5, or 10 mg/kg) was infused continuously 30 min after LPS administration, followed by infusion at 5 mg/(kg · h) through the left femoral vein cannula. LPS increased wet to dry weight ratio and myeloperoxidase activity in lung tissues and caused the elevation of total protein and cells, neutrophils, macrophages, and neutrophils in bronchoalveolar lavage fluid (BALF). Moreover, HMGB1 and other cytokine levels were increased in BALF and lung tissues and pathological changes of lung tissues were excessively aggravated in rats after LPS administration. Propofol inhibited all the above effects. It also inhibited LPS-induced toll-like receptor (TLR)2/4 protein upexpression and NF-κB activation in lung tissues and human alveolar epithelial cells. Propofol protects rats and human alveolar epithelial cells against HMGB1 expression in a rat model of LPS-induced ALI. These effects may partially result from reductions in TLR2/4 and NF-κB activation.

  12. A cytosolic protein factor from the naked mole-rat activates proteasomes of other species and protects these from inhibition

    PubMed Central

    Rodriguez, Karl A.; Osmulski, Pawel A.; Pierce, Anson; Weintraub, Susan T.; Gaczynska, Maria; Buffenstein, Rochelle

    2015-01-01

    The naked mole-rat maintains robust proteostasis and high levels of proteasome-mediated proteolysis for most of its exceptional (~31y) life span. Here, we report that the highly active proteasome from the naked mole-rat liver resists attenuation by a diverse suite of proteasome-specific small molecule inhibitors. Moreover, mouse, human, and yeast proteasomes exposed to the proteasome-depleted, naked mole-rat cytosolic fractions, recapitulate the observed inhibition resistance, and mammalian proteasomes also show increased activity. Gel filtration coupled with mass spectrometry and atomic force microscopy indicates that these traits are supported by a protein factor that resides in the cytosol. This factor interacts with the proteasome and modulates its activity. Although HSP72 and HSP40 (Hdj1) are among the constituents of this factor, the observed phenomenon, such as increasing peptidase activity and protecting against inhibition cannot be reconciled with any known chaperone functions. This novel function may contribute to the exceptional protein homeostasis in the naked mole-rat and allow it to successfully defy aging. PMID:25018089

  13. EDTA-mediated inhibition of DNases protects circulating cell-free DNA from ex vivo degradation in blood samples.

    PubMed

    Barra, Gustavo Barcelos; Santa Rita, Ticiane Henriques; de Almeida Vasques, Júlia; Chianca, Camilla Figueiredo; Nery, Lídia Freire Abdalla; Santana Soares Costa, Sandra

    2015-10-01

    The extracellular DNA occurring in plasma-EDTA and serum is a biomarker of growing interest, especially in prenatal diagnosis and oncology. The objectives of the present study were to compare the DNase activity in these specimens and to investigate its ex-vivo impact over the circulating cell-free DNA yield (ccfDNA), using the circulating cell-free fetal DNA (ccffDNA) as a tool. EDTA-plasma and serum from women bearing male fetus were submitted to an endogenous DNase activity assay based on qPCR hydrolysis probe degradation, they were treated with DNAse I to investigate the action of an exogenous nuclease and also submitted to different temperature conditions to investigate the temperature-dependent degradation of the ccffDNA. In all instances, all male ccffDNA were quantified by qPCR targeting the Y chromosome-specific sequence DYS-14. Moreover, a serial dilution of EDTA was added to nonanticoagulated plasma and serum before the endogenous DNAse activity assay, to investigate the EDTA-mediated inhibition of the blood's DNase. The endogenous nuclease activity was 14.9-fold higher in serum compared to EDTA-plasma. The DNAse I treatment did not alter the ccffDNA yields in EDTA-plasma, but completely degraded it in serum. The addition of increasing doses of EDTA to nonanticoagulated plasma and serum resulted in a stepwise inhibition of their nucleases activity. Finally, we observed a much more pronounced temperature-mediated decrease on the ccffDNA amount in serum compared to EDTA-plasma. The exogenous and endogenous DNases are more active in serum, the anticoagulant EDTA indirectly inhibits blood DNases, and consequently ccfDNA is protected from the blood's DNase preanalytical impact in EDTA-plasma. Copyright © 2015. Published by Elsevier Inc.

  14. Protective effects of SIRT1 in patients with proliferative diabetic retinopathy via the inhibition of IL-17 expression

    PubMed Central

    LIU, SHULIN; LIN, YU; LIU, XIN

    2016-01-01

    Diabetic retinopathy (DR) is a chronic microvascular complication of diabetes that may lead to loss of vision. The pathogenesis of DR is complex and elevated expression levels of T helper (Th)17 cells and interleukin (IL)-17 have been suggested to be associated with the development and progression of DR. Sirtuin 1 (SIRT1) is a nicotinamide-adenine dinucleotide+-dependent histone deacetylase that is downregulated in patients with DR. Previous studies have demonstrated that SIRT1 is capable of inhibiting the production of IL-17. In the present study, 19 patients with proliferative diabetic retinopathy (PDR) and 20 non-diabetic controls with idiopathic macular epiretinal membranes were recruited and the SIRT1 expression levels of excised specimens were analyzed using immunohistochemistry. IL-17 expression levels in the sera from patients with PDR and controls were determined by enzyme-linked immunosorbent assay (ELISA). Furthermore, SIRT1 mRNA and protein expression levels in peripheral blood mononuclear cells (PBMCs) from the two groups were analyzed following culture with or without a SIRT1 activator, resveratrol. IL-17 expression levels in the supernatants of PBMCs were determined using ELISA and the results demonstrated that IL-17 expression levels were increased in the sera of patients with PDR, as compared with the controls. Furthermore, increased expression levels of SIRT1 and IL-17 were detected in fibrovascular membranes and PBMCs harvested from patients with PDR, respectively. Notably, SIRT1 mRNA and protein expression levels were decreased in the PBMCs of patients with PDR and IL-17 production was inhibited following SIRT1 activation. The results of the present study indicated that imbalanced IL-17 and SIRT1 expression levels may contribute to the pathogenesis of DR, and SIRT1 may have a protective role in PDR by inhibiting the production of IL-17. PMID:26889251

  15. Fisetin protects against hepatosteatosis in mice by inhibiting miR-378.

    PubMed

    Jeon, Tae-Il; Park, Jin Wook; Ahn, Jiyun; Jung, Chang Hwa; Ha, Tae Youl

    2013-11-01

    Lipid homeostasis in vertebrates is regulated at many levels including synthesis, degradation, and distribution. MicroRNAs (miRNAs) are key regulators of lipid homeostasis. The use of phytochemicals to target miRNA (miR) could provide new therapeutic approaches to human diseases. Thus, we investigated the regulation of lipid metabolism by the flavonoid fisetin during experimental analysis of hepatic miRs in mice. Mice were separated into three groups. One group was maintained on the normal diet and the other two groups were fed either a high-fat (HF) diet or HF supplemented with fisetin. We found that fisetin lowered hepatic fat accumulation in HF mice and reversed abnormal expressions of lipid metabolism genes. The co-expression of miR-378 and its host gene PGC-1β was significantly induced by HF, whereas fisetin prevented the induction of both genes. We also identified nuclear respiratory factor-1 (NRF-1), a critical regulator of the mitochondrial function, as a direct target of miR-378. Dietary fisetin protects against hepatosteatosis in association with modulation of lipid metabolism genes and miR-378 in mice. These observations suggest that the use of fisetin to target miRs could be an effective prevention or intervention against metabolic diseases. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Arctigenin protects focal cerebral ischemia-reperfusion rats through inhibiting neuroinflammation.

    PubMed

    Fan, Tao; Jiang, Wei Long; Zhu, Jian; Feng Zhang, Yu

    2012-01-01

    Stroke is the third leading cause of death in industrialized countries and the most important cause of acquired adult disability. Many evidences suggest that inflammation accounts for the progression of cerebral ischemic injury. Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignin isolated from certain plants, has shown anti-inflammatory activity against diabetes and Alzheimer's disease. In this study, we tested whether arctigenin can protect middle cerebral artery occluded (MCAO) rats. Male Sprague-Dawley rats were pretreated with arctigenin or vehicle for 7 d before being subjected to transient occlusion of middle cerebral artery and reperfusion. Rats were evaluated at 24 h after MCAO for neurological deficit scoring. Furthermore, the mechanism of the anti-inflammatory effect of arctigenin was investigated with a focus on inflammatory cells, proinflammatory cytokines, and transcriptional factors. Arctigenin significantly reduced cerebral infarction and improved neurological outcome. Arctigenin suppressed the activation of microglia and decreased the expression of interleukin (IL)- 1β and tumor necrosis factor (TNF)-α. These results revealed that arctigenin has a promising therapeutic effect in ischemic stroke treatment through an anti-inflammatory mechanism.

  17. Inhibition of phospholipase A2 (PLA2) activity by nifedipine and nisoldipine is independent of their calcium-channel-blocking activity

    SciTech Connect

    Chang, J.; Blazek, E.; Carlson, R.P.

    1987-09-01

    The effects of several calcium antagonists on phospholipase A2 (PLA2) activity were examined. Nifedipine and nisoldipine inhibited a cell-free preparation of PLA2 in a dose-dependent manner with maximal inhibition of 71-77% observed at 100 microM. More potent or equipotent dihydropyridine calcium antagonists such as nitrendipine and felodipine did not inhibit PLA2 activity. In addition, nondihydropyridine calcium antagonists such as diltiazem, verapamil, and cinnarazine failed to reduce PLA2 activity markedly. Nifedipine and nisoldipine also reduced PLA2 activity in intact mouse peritoneal macrophages where PLA2 activity was monitored by free (/sup 14/C)arachidonic acid release from (/sup 14/C)arachidonic acid-prelabeled cells. When levels of PGE2 and LTC4 were measured by radioimmunoassay, it was found that the synthesis of these two metabolites was concomitantly inhibited by nifedipine and nisoldipine. In vivo, nifedipine and nisoldipine inhibited tetradecanoylphorbol acetate (TPA) induced ear edema. UV irradiation of nifedipine and nisoldipine (which destroys the slow calcium-channel-blocking activity of these compounds) did not result in a loss of PLA2 inhibitory activity. In fact, in both instances the UV-irradiated forms of nifedipine and nisoldipine were slightly more potent PLA2 inhibitors than the parent compound alone. We therefore conclude that the ability of nifedipine and nisoldipine to inhibit PLA2 was direct and unrelated to their actions on slow calcium channels.

  18. Protective effect of Schizandrin B against damage of UVB irradiated skin cells depend on inhibition of inflammatory pathways.

    PubMed

    Gao, Chenguang; Chen, Hong; Niu, Cong; Hu, Jie; Cao, Bo

    2017-01-02

    Schizandrin B is extracted from Schisandra chinensis (Turcz.) Baill. This study evaluated the photoprotective effect of Schizandrin B on oxidative stress injury of the skin caused by UVB-irradiation and the molecular mechanism of the photoprotective effect of Schizandrin B, and we firstly found that Schizandrin B could block Cox-2, IL-6 and IL-18 signal pathway to protect damage of skin cells given by UVB-irradiation. In the research, we found that Schizandrin B can attenuate the UVB-induced toxicity on keratinocytes and dermal fibroblasts in human body, and can outstandingly eliminated intracellular ROS produced by UVB-irradiation. These results demonstrate that Schizandrin B can regulate the function of decreasing intracellular SOD's activity and increasing the expression level of MDA in HaCaT cells result from the guidance of UVB, and it markedly reduced the production of inflammatory factors such as Cox-2, IL-6 or IL-18, decreased the expression level of MMP-1, and interdicted degradation process of collagens in UVB-radiated cells. Therefore, skin keratinocytes can be effectively protected from UVB-radiated damage by Schizandrin B, and UVB-irradiation caused inflammatory responses can be inhibited by attenuating process of ROS generating.

  19. Pterostilbene attenuates lipopolysaccharide-induced learning and memory impairment possibly via inhibiting microglia activation and protecting neuronal injury in mice.

    PubMed

    Hou, Yue; Xie, Guanbo; Miao, Fengrong; Ding, Lingling; Mou, Yanhua; Wang, Lihui; Su, Guangyue; Chen, Guoliang; Yang, Jingyu; Wu, Chunfu

    2014-10-03

    The present study aims to evaluate the effects of pterostilbene on lipopolysaccharide (LPS)-induced learning and memory impairment as well as the possible changes of microglia and neurons. Firstly, learning and memory function was investigated by behavioral tests. Pterostilbene attenuated LPS-induced learning and memory impairment tested by Y-maze and Morris water maze. Secondly, immunohistochemical method was used to study the changes of microglia and neurons. The results showed that pterostilbene produced a significant decrease in the number of Iba-1 and Doublecortin (DCX) positive cells and a significant increase in neuronal nuclear antigen (NeuN)-stained area of neurons in mouse hippocampal compared to the LPS group. Finally, an in vitro study was performed to further confirm the inhibitory effect on microglia activation and protective effect on neurons exerted by pterostilbene. The results demonstrated that pterostilbene significantly inhibited microglia activation, showing the obvious decrease of LPS-induced production of NO, TNF-α and IL-6 in N9 microglial cells. In addition, the viability of SH-SY5Y cells decreased by conditioned media of LPS-activated N9 microglial cells was remarkably recovered by pterostilbene. In summary, the present study demonstrated for the first time that pterostilbene attenuated LPS-induced learning and memory impairment, which may be associated with its inhibitory effect on microglia activation and protective effect on neuronal injury.

  20. Inhibition of sterile danger signals, uric acid and ATP, prevents inflammasome activation and protects from alcoholic steatohepatitis in mice

    PubMed Central

    Iracheta-Vellve, Arvin; Petrasek, Jan; Satishchandran, Abhishek; Gyongyosi, Benedek; Saha, Banishree; Kodys, Karen; Fitzgerald, Katherine A.; Kurt-Jones, Evelyn A.; Szabo, Gyongyi

    2015-01-01

    Background & Aims The inflammasome is a well-characterized inducer of inflammation in ASH. Inflammasome activation requires two signals for mature interleukin (IL)-1β production. Here we asked whether metabolic danger signals trigger inflammasome activation in ASH. Methods Wild-type mice, ATP receptor 2×7 (P2rx7)-KO mice, or mice overexpressing uricase were fed Lieber-DeCarli ethanol or control diet. We also implemented a pharmacological approach in which mice were treated with probenecid or allopurinol. Results The sterile danger signals, ATP and uric acid, were increased in the serum and liver of alcohol-fed mice. Depletion of uric acid or ATP, or lack of ATP signaling attenuated ASH and prevented inflammasome activation and its major downstream cytokine, IL-1β. Pharmacological depletion of uric acid with allopurinol provided significant protection from alcohol-induced inflammatory response, steatosis and liver damage, and additional protection was achieved in mice treated with probenecid, which depletes uric acid and blocks ATP-induced P2rx7 signaling. We found that alcohol-damaged hepatocytes released uric acid and ATP in vivo and in vitro and that these sterile danger signals activated the inflammasome in LPS-exposed liver mononuclear cells. Conclusions Our data indicate that the second signal in inflammasome activation and IL-1β production in ASH results from the endogenous danger signals, uric acid and ATP. Inhibition of signaling triggered by uric acid and ATP may have therapeutic implications in ASH. PMID:26100496

  1. ATR inhibition disrupts rewired homologous recombination and fork protection pathways in PARP inhibitor-resistant BRCA-deficient cancer cells

    PubMed Central

    Yazinski, Stephanie A.; Comaills, Valentine; Buisson, Rémi; Genois, Marie-Michelle; Nguyen, Hai Dang; Ho, Chu Kwen; Todorova Kwan, Tanya; Morris, Robert; Lauffer, Sam; Nussenzweig, André; Ramaswamy, Sridhar; Benes, Cyril H.; Haber, Daniel A.; Maheswaran, Shyamala; Birrer, Michael J.; Zou, Lee

    2017-01-01

    Poly-(ADP-ribose) polymerase (PARP) inhibitors (PARPis) selectively kill BRCA1/2-deficient cells, but their efficacy in BRCA-deficient patients is limited by drug resistance. Here, we used derived cell lines and cells from patients to investigate how to overcome PARPi resistance. We found that the functions of BRCA1 in homologous recombination (HR) and replication fork protection are sequentially bypassed during the acquisition of PARPi resistance. Despite the lack of BRCA1, PARPi-resistant cells regain RAD51 loading to DNA double-stranded breaks (DSBs) and stalled replication forks, enabling two distinct mechanisms of PARPi resistance. Compared with BRCA1-proficient cells, PARPi-resistant BRCA1-deficient cells are increasingly dependent on ATR for survival. ATR inhibitors (ATRis) disrupt BRCA1-independent RAD51 loading to DSBs and stalled forks in PARPi-resistant BRCA1-deficient cells, overcoming both resistance mechanisms. In tumor cells derived from patients, ATRis also overcome the bypass of BRCA1/2 in fork protection. Thus, ATR inhibition is a unique strategy to overcome the PARPi resistance of BRCA-deficient cancers. PMID:28242626

  2. Anti–IL-20 monoclonal antibody inhibits the differentiation of osteoclasts and protects against osteoporotic bone loss

    PubMed Central

    Hsu, Yu-Hsiang; Chen, Wei-Yu; Chan, Chien-Hui; Wu, Chih-Hsing; Sun, Zih-Jie

    2011-01-01

    IL-20 is a proinflammatory cytokine of the IL-10 family that is involved in psoriasis, rheumatoid arthritis, atherosclerosis, and stroke. However, little is known about the role of IL-20 in bone destruction. We explored the function of IL-20 in osteoclastogenesis and the therapeutic potential of anti–IL-20 monoclonal antibody 7E for treating osteoporosis. Higher serum IL-20 levels were detected in patients with osteopenia and osteoporosis and in ovariectomized (OVX) mice. IL-20 mediates osteoclastogenesis by up-regulating the receptor activator of NF-κB (RANK) expression in osteoclast precursor cells and RANK ligand (RANKL) in osteoblasts. 7E treatment completely inhibited osteoclast differentiation induced by macrophage colony-stimulating factor (M-CSF) and RANKL in vitro and protected mice from OVX-induced bone loss in vivo. Furthermore, IL-20R1–deficient mice had significantly higher bone mineral density (BMD) than did wild-type controls. IL-20R1 deficiency also abolished IL-20–induced osteoclastogenesis and increased BMD in OVX mice. We have identified a pivotal role of IL-20 in osteoclast differentiation, and we conclude that anti–IL-20 monoclonal antibody is a potential therapeutic for protecting against osteoporotic bone loss. PMID:21844205

  3. Protection Effect of Zhen-Wu-Tang on Adriamycin-Induced Nephrotic Syndrome via Inhibiting Oxidative Lesions and Inflammation Damage

    PubMed Central

    Liang, Chun-ling; Wu, Jun-biao; Lai, Jie-mei; Ye, Shu-fang; Lin, Jin; Ouyang, Hui; Zhan, Janis Ya-xian; Zhou, Jiu-yao

    2014-01-01

    Zhen-wu-tang (ZWT), a well-known formula in China, is widely used to treat chronic kidney diseases. However, very little information on ZWT's mechanism of action is currently available. In this study, we investigated the possible protective role and underlying mechanism of ZWT on nephrotic syndrome (NS) induced by Adriamycin (intravenous injection, 6.0 mg/kg) in rats using biochemical and histopathological approaches. ZWT decreased urine protein excretion and the serum levels of total cholesterol, triglycerides, blood urea nitrogen, and creatinine significantly in diseased rats. A decrease in plasma levels of total protein and albumin was also recorded in nephropathic rats. Pathological results show an improved pathological state and recovering glomerular structure in ZWT treatment groups. ZWT decreased renal IL-8 level but increased renal IL-4 level. In addition, rats subjected to ZWT exhibited less IgG deposition in glomerulus compared with model group. RT-PCR results showed that ZWT decreased the mRNA expression of NF-κB p65 and increased the mRNA expression of IκB. Furthermore, ZWT reduced the level of MDA and increased SOD activity. These results demonstrated that ZWT ameliorated Adriamycin-induced NS in rats possibly by inhibiting Adriamycin-induced inflammation damage, enhancing body's antioxidant capacity, thereby protecting glomerulus from injury. PMID:24812565

  4. Protective Role of Sodium-Glucose Co-Transporter 2 Inhibition Against Vascular Complications in Diabetes.

    PubMed

    Yamagishi, Sho-ichi; Matsui, Takanori

    2016-04-01

    Diabetic micro- and macroangiopathy are devastating vascular complications that could account for disabilities and high mortality rate in patients with diabetes. Indeed, diabetic nephropathy and retinopathy are the leading causes of end-stage renal failure and acquired blindness, respectively, and atherosclerotic cardiovascular diseases (CVD) accounts for about 60% of death in diabetic subjects. As a result, the average life span of diabetic patients is about 10-15 years shorter than that of non-diabetic subjects. Furthermore, tight blood glucose control might have no more than a marginal impact on CVD in general and on all-cause mortality in particular in diabetes. Therefore, therapeutic strategies that target vascular complications in diabetes need to be developed. Recently, selective inhibition of sodium-glucose co-transporter 2 (SGLT2) has been proposed as a potential therapeutic target for the treatment of patients with diabetes because of low risk of hypoglycemia and no weight gain. Because 90% of glucose filtered by the glomerulus is reabsorbed by a low-affinity/high-capacity SGLT2 expressed in the S1 and S2 segments of the proximal tubule, blockade of SGLT2 promotes urinary glucose excretion and as a result improves hyperglycemia in an insulin-independent manner. Moreover, we have shown that SGLT2-mediated glucose overload to tubular cells could elicit inflammatory and pro-apoptotic reactions in this cell, being directly involved in diabetic nephropathy. In addition, several clinical studies have also shown that SGLT2 inhibitors could reduce blood pressure, body weight, and serum uric acid levels and ameliorate cardiovascular risk in patients with diabetes. This review summarizes the pathophysiological role of SGLT2 in vascular complications in diabetes and its potential therapeutic interventions.

  5. Influence of aromatase inhibition on the bone-protective effects of testosterone.

    PubMed

    Beck, Darren T; Yarrow, Joshua F; Beggs, Luke A; Otzel, Dana M; Ye, Fan; Conover, Christine F; Miller, Julie R; Balaez, Alexander; Combs, Sarah M; Leeper, Alicia M; Williams, Alyssa A; Lachacz, Stephanie A; Zheng, Nigel; Wronski, Thomas J; Borst, Stephen E

    2014-11-01

    The influence of the aromatase enzyme in androgen-induced bone maintenance after skeletal maturity remains somewhat unclear. Our purpose was to determine whether aromatase activity is essential to androgen-induced bone maintenance. Ten-month-old male Fisher 344 rats (n = 73) were randomly assigned to receive Sham surgery, orchiectomy (ORX), ORX + anastrozole (AN; aromatase inhibitor), ORX + testosterone-enanthate (TE, 7.0 mg/wk), ORX + TE + AN, ORX + trenbolone-enanthate (TREN; nonaromatizable, nonestrogenic testosterone analogue; 1.0 mg/wk), or ORX + TREN + AN. ORX animals exhibited histomorphometric indices of high-turnover osteopenia and reduced cancellous bone volume compared with Shams. Both TE and TREN administration suppressed cancellous bone turnover similarly and fully prevented ORX-induced cancellous bone loss. TE- and TREN-treated animals also exhibited greater femoral neck shear strength than ORX animals. AN co-administration slightly inhibited the suppression of bone resorption in TE-treated animals but did not alter TE-induced suppression of bone formation or the osteogenic effects of this androgen. In TREN-treated animals, AN co-administration produced no discernible effects on cancellous bone turnover or bone volume. ORX animals also exhibited reduced levator ani/bulbocavernosus (LABC) muscle mass and elevated visceral adiposity. In contrast, TE and TREN produced potent myotrophic effects in the LABC muscle and maintained fat mass at the level of Shams. AN co-administration did not alter androgen-induced effects on muscle or fat. In conclusion, androgens are able to induce direct effects on musculoskeletal and adipose tissue, independent of aromatase activity.

  6. The mitochondrial unfolded protein response activator ATFS-1 protects cells from inhibition of the mevalonate pathway

    PubMed Central

    Rauthan, Manish; Ranji, Parmida; Aguilera Pradenas, Nataly; Pitot, Christophe; Pilon, Marc

    2013-01-01

    Statins are cholesterol-lowering drugs that inhibit 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, the rate-limiting enzyme in the synthesis of cholesterol via the mevalonate pathway. This pathway also produces coenzyme Q (a component of the respiratory chain), dolichols (important for protein glycosylation), and isoprenoids (lipid moieties responsible for the membrane association of small GTPases). We previously showed that the nematode Caenorhabditis elegans is useful to study the noncholesterol effects of statins because its mevalonate pathway lacks the sterol synthesis branch but retains all other branches. Here, from a screen of 150,000 mutagenized genomes, we isolated four C. elegans mutants resistant to statins by virtue of gain-of-function mutations within the first six amino acids of the protein ATFS-1, the key regulator of the mitochondrial unfolded protein response that includes activation of the chaperones HSP-6 and HSP-60. The atfs-1 gain-of-function mutants are also resistant to ibandronate, an inhibitor of an enzyme downstream of HMG-CoA reductase, and to gliotoxin, an inhibitor acting on a subbranch of the pathway important for protein prenylation, and showed improved mitochondrial function and protein prenylation in the presence of statins. Additionally, preinduction of the mitochondrial unfolded protein response in wild-type worms using ethidium bromide or paraquat triggered statin resistance, and similar observations were made in Schizosaccharomyces pombe and in a mammalian cell line. We conclude that statin resistance through maintenance of mitochondrial homeostasis is conserved across species, and that the cell-lethal effects of statins are caused primarily through impaired protein prenylation that results in mitochondria dysfunction. PMID:23530189

  7. Carbon dioxide but not bicarbonate inhibits N-nitrosation of secondary amines. Evidence for amine carbamates as protecting entities.

    PubMed

    Kirsch, M; Korth, H G; Sustmann, R; de Groot, H

    2000-06-01

    Hydrogen carbonate (bicarbonate, HCO(3)(-)) has been proposed to accelerate the decomposition of N(2)O(3) because N-nitrosation of morpholine via a nitric oxide/oxygen mixture ((*)NO/O(2)) was inhibited by the addition of HCO(3)(-) at pH 8.9 [Caulfield, J. L., Singh, S. P., Wishnok, J. S., Deen, W. M., and Tannenbaum, S. R. (1996) J. Biol. Chem. 271, 25859-25863]. In the study presented here, it is shown that carbon dioxide (CO(2)) is responsible for this kind of protective effect because of formation of amine carbamates, whereas an inhibitory function of HCO(3)(-) is excluded. N-Nitrosation of morpholine (1-10 mM) at pH 7.4-7.5 by the (*)NO-donor compounds PAPA NONOate and MAMA NONOate (0.5 mM each) was not affected by the presence of large amounts of HCO(3)(-) (up to 100 mM) in aerated aqueous solution. Similar results were obtained by replacing the (*)NO-donor compounds with authentic (*)NO (900 microM). In agreement with data from the study cited above, (*)NO/O(2)-mediated formation of N-nitrosomorpholine (NO-Mor) was indeed inhibited by about 45% in the presence of 50 mM HCO(3)(-) at pH 8.9. However, 500 MHz (13)C NMR analysis with (13)C-enriched bicarbonate revealed that significant amounts of morpholine carbamate are formed from reaction of equilibrated CO(2) with morpholine (1-100 mM) at pH 8.9, but only to a minor extent at pH 7. 5. The protective effect of morpholine carbamate formation is explained by a significantly reduced charge density at nitrogen. This view is supported by the results of density functional theory/natural population analysis, i.e., quantumchemical calculations for morpholine and morpholine carbamate. In agreement with its lower pK(a), another secondary amine, piperazine, had already produced significant amounts of piperazine carbamate at pH 7. 4 as shown by (13)C NMR spectrometry. Consequently, and in contrast to morpholine, N-nitrosation of piperazine (2 mM) by both (*)NO/O(2) (PAPA NONOate, 0.5 mM) and the (*)NO/O(2

  8. [Protective effects of garlic oil on n-hexane-induced neurotoxicity in rats via inhibition of hepatic alcohol dehydrogenase activity].

    PubMed

    Bi, Ye; Chen, Jing-Jing; Yan, Jie; Zeng, Tao; Fu, Qiang-Qiang; Zhong, Zhi-Xia; Xie, Ke-Qin

    2011-08-01

    To study the protective effects of garlic oil (GO) on the peripheral nerve injuries induced by n-hexane. Male Wistar rats were randomly divided into four groups (10 rats in each group): the control, the n-hexane treatment (2000 mg/kg), the low dose GO, and the high dose GO groups. The rats in the low and high doses of GO groups were pretreated with GO (40 and 80 mg/kg) before exposure to n-hexane (2000 mg/ kg), while the animals of the n-hexane treatment group were given normal saline and then 2000 mg/ kg n-hexane. The rats were exposed to GO and n-hexane 6 times a week for 10 weeks. The gait scores and staying time on the rotating rod for all rats were detected every two weeks. The rats were sacrificed at the end of ten weeks, then the levels of alcohol dehydrogenase (ADH), maleic dialdehyde (MDA), reduced glutathione (GSH), glutathione peroxidase(GSH-Px), total antioxidation capacity(T-AOC) and the ability of inhibition of *OH in livers were examined. The gait scores increased significantly and the time staying on the rotating rod obviously decreased in rats of n-hexane treatment group, as compared with control group (P < 0.05 or P < 0.01). In the hepatic tissues of n-hexane group, the levels of MDA and ADH significantly increased, the activities of GSH-Px, T-AOC and the ability of inhibition of *OH obviously decreased, as compared to control group (P < 0.05 or P < 0.01). In 2 GO groups, the gait scores and the staying time on the rotating rod were significantly improved, the levels of MDA and ADH significantly decreased, the activities of GSH-Px, T-AOC and the ability of inhibition of *OH obviously increased, as compared with n-hexane group (P < 0.05 or P < 0.01 ). ADH could play an important role in the protective effects induced by garlic oil on the peripheral nerve injuries produced by n-hexane.

  9. Colistin inhibits E. coli O157:H7 Shiga-like toxin release, binds endotoxins and protects Vero cells.

    PubMed

    Percivalle, Elena; Monzillo, Vincenzina; Pauletto, Alessandro; Marone, Piero; Imberti, Roberto

    2016-04-01

    The role of antibiotics in the treatment of Shiga-like toxin (Stx)-producing E. coli infection is still controversial. This study investigated the effects of colistin on Vero cell cytotoxicity caused by the enterohemorrhagic EC O157:H7, and the effects of colistin on Stx and endotoxin release by EC O157:H7. Vero cells were incubated with supernatant collected from EC O157:H7 cultured for 18 h without (control) or with various concentrations of colistin. In the absence of colistin, Vero cell viability after 48 h was 29.1±6.5%. Under the same conditions, the overnight presence of colistin reduced cytotoxicity to Vero cells (viability: 97±3.5 to 56.5±14.4% for colistin concentrations ≥MIC). Sub-MIC concentrations of colistin also provided partial protection (viability: 38.8±12.5 to 36.6±14% for 0.125 and 0.06 mcg/ml colistin, respectively). Endotoxins contributed to the cytotoxic effects on Vero cells since lower but still significant protection was observed when colistin was added directly to the supernatant collected from cultures of untreated EC O157:H7. Colistin reduced Stx release in a concentration-dependent manner, also at sub-MIC concentrations. Coincubation of the supernatant from EC O157:H7 cultures with colistin markedly reduced the endotoxin concentration at all doses investigated. In conclusion, colistin protects Vero cells from EC O157:H7 at supra- and sub-MIC concentrations by inhibiting Stx release and binding endotoxins. Colistin might be a valuable treatment for clinically severe forms of EC O157:H7 infection.

  10. Interleukin-22-Induced Antimicrobial Phospholipase A2 Group IIA Mediates Protective Innate Immunity of Nonhematopoietic Cells against Listeria monocytogenes.

    PubMed

    Okita, Yamato; Shiono, Takeru; Yahagi, Ayano; Hamada, Satoru; Umemura, Masayuki; Matsuzaki, Goro

    2015-12-07

    Listeria monocytogenes is a bacterial pathogen which establishes intracellular parasitism in various cells, including macrophages and nonhematopoietic cells, such as hepatocytes. It has been reported that several proinflammatory cytokines have pivotal roles in innate protection against L. monocytogenes infection. We found that a proinflammatory cytokine, interleukin 22 (IL-22), was expressed by CD3(+) CD4(+) T cells at an early stage of L. monocytogenes infection in mice. To assess the influence of IL-22 on L. monocytogenes infection in hepatocytes, cells of a human hepatocellular carcinoma line, HepG2, were treated with IL-22 before L. monocytogenes infection in vitro. Gene expression analysis of the IL-22-treated HepG2 cells identified phospholipase A2 group IIA (PLA2G2A) as an upregulated antimicrobial molecule. Addition of recombinant PLA2G2A to the HepG2 culture significantly suppressed L. monocytogenes infection. Culture supernatant of the IL-22-treated HepG2 cells contained bactericidal activity against L. monocytogenes, and the activity was abrogated by a specific PLA2G2A inhibitor, demonstrating that HepG2 cells secreted PLA2G2A, which killed extracellular L. monocytogenes. Furthermore, colocalization of PLA2G2A and L. monocytogenes was detected in the IL-22-treated infected HepG2 cells, which suggests involvement of PLA2G2A in the mechanism of intracellular killing of L. monocytogenes by HepG2 cells. These results suggest that IL-22 induced at an early stage of L. monocytogenes infection enhances innate immunity against L. monocytogenes in the liver by stimulating hepatocytes to produce an antimicrobial molecule, PLA2G2A.

  11. Trazodone treatment protects neuronal-like cells from inflammatory insult by inhibiting NF-κB, p38 and JNK.

    PubMed

    Daniele, Simona; Da Pozzo, Eleonora; Zappelli, Elisa; Martini, Claudia

    2015-08-01

    inhibited, and the release of interleukin-10 was restored to control levels. Furthermore, the intracellular signalling mechanism regulating TDZ-elicited effects was specifically investigated. TDZ induced extracellular signal-regulated kinase (ERK) phosphorylation and inhibited constitutive p38 activation. Moreover, TDZ counteracted the activation of p38 and c-Jun NH2-terminal kinase (JNK) elicited by LPS-TNF-α, suggesting that the neuro-protective role of TDZ could be mediated by p38 and JNK. Overall, our results demonstrated that the protective effects of TDZ under inflammation in neuronal-like cells function by decreasing pro-inflammatory signalling and by enhancing anti-inflammatory signalling.

  12. Synthesis and characterization of novel coatings for corrosion protection and hydrogen embrittlement inhibition

    NASA Astrophysics Data System (ADS)

    Durairajan, Anand

    The degradation of metallic materials under the effect of corrosion is a costly problem, which nearly every industry is confronted with. By using electrochemical plating, one can alter the characteristics of a surface so as to provide improved appearance, ability to withstand corrosive agents, resistance to abrasion, improved electrocatalytic properties or other desired properties or a combination of them. The primary goal of this dissertation is to use electrochemical deposition (electrolytic and electroless) as a surface modification technique to obtain corrosion resistant high performance electrode materials for different electrochemical applications. Metal hydride alloys, which reversibly absorb/desorb hydrogen, have been used in battery applications. The continuous decrease in the absorb/desorbing capacity of these alloys has been attributed to the corrosion of the alloy. Cobalt encapsulation (electroless) has been used as a surface modification method to obtain high performance AB5 type metal hydride alloy. The coated material has a higher capacity and longer cycle life compared to the bare alloy. Pulverization and alloy oxidation---two prime reasons for capacity fading of MH alloys have been studied in greater detail using unique electrochemical and physical characterization methods. The harmful effects of hydrogen permeation (ingress) and related stress corrosion cracking (SCC) can limit the use of metals and alloys in aqueous environments. In the present work, a new Zn-Ni-Cd plating process which offers a unique way of controlling and optimizing the Zn and Cd contents in the final deposit, has been developed. The Zn Ni-Cd alloy coatings has a more anodic corrosion potential than that of Cd but higher than the corrosion potential of iron. The coatings have superior corrosion resistance (10 times higher) and barrier properties than the conventional Cd coatings. Zn-Ni-Cd coatings also inhibit the hydrogen entry into the underlying steel. The kinetic

  13. Inhibition of protein synthesis occurring on tetracycline-resistant, TetM-protected ribosomes by a novel class of tetracyclines, the glycylcyclines.

    PubMed

    Rasmussen, B A; Gluzman, Y; Tally, F P

    1994-07-01

    One of the two major mechanisms of tetracycline resistance is ribosomal protection. Of this resistance type, tet(M) is the best characterized. Although the mechanism of tet(M) resistance has not yet been fully elucidated, it has been demonstrated that ribosomes isolated from a tet(M) strain are resistant to inhibition of protein synthesis by tetracycline. A new generation of tetracycline compounds, the glycylcyclines, that are able to inhibit protein synthesis occurring on tetracycline-resistant, TetM-protected ribosomes, as well as wild-type, tetracycline-sensitive ribosomes, have been identified.

  14. Making healthier or killing enemies? Bacterial volatile-elicited plant immunity plays major role upon protection of Arabidopsis than the direct pathogen inhibition

    PubMed Central

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    ABSTRACT Bacterial volatiles protect plants either by directly inhibiting a pathogenic fungus or by improving the defense capabilities of plants. The effect of bacterial volatiles on fungal growth was dose-dependent. A low dosage did not have a noticeable effect on Botrytis cinerea growth and development, but was sufficient to elicit induced resistance in Arabidopsis thaliana. Bacterial volatiles displayed negative effects on biofilm formation on a polystyrene surface and in in planta leaf colonization of B. cinerea. However, bacterial volatile-mediated induced resistance was the major mechanism mediating protection of plants from B. cinerea. It was responsible for more than 90% of plant protection in comparison with direct fungal inhibition. Our results broaden our knowledge of the role of bacterial volatiles in plant protection. PMID:27574539

  15. Making healthier or killing enemies? Bacterial volatile-elicited plant immunity plays major role upon protection of Arabidopsis than the direct pathogen inhibition.

    PubMed

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    Bacterial volatiles protect plants either by directly inhibiting a pathogenic fungus or by improving the defense capabilities of plants. The effect of bacterial volatiles on fungal growth was dose-dependent. A low dosage did not have a noticeable effect on Botrytis cinerea growth and development, but was sufficient to elicit induced resistance in Arabidopsis thaliana. Bacterial volatiles displayed negative effects on biofilm formation on a polystyrene surface and in in planta leaf colonization of B. cinerea. However, bacterial volatile-mediated induced resistance was the major mechanism mediating protection of plants from B. cinerea. It was responsible for more than 90% of plant protection in comparison with direct fungal inhibition. Our results broaden our knowledge of the role of bacterial volatiles in plant protection.

  16. Neuroprotection of rat hippocampal slices exposed to oxygen-glucose deprivation by enrichment with docosahexaenoic acid and by inhibition of hydrolysis of docosahexaenoic acid-containing phospholipids by calcium independent phospholipase A2.

    PubMed

    Strokin, M; Chechneva, O; Reymann, K G; Reiser, G

    2006-06-30

    Polyunsaturated fatty acids play an important role in the development of pathological states in brain after hypoxia/ischemia. Here, we investigated the role of docosahexaenoic acid (22:6n-3) in brain phospholipids for neuronal survival. We used organotypic cultures of rat brain hippocampal slices exposed to 40 min of oxygen-glucose deprivation, to study the consequences of experimental ischemia. In [14C]docosahexaenoic acid-labeled cultures, oxygen-glucose deprivation induced significant release of radioactive docosahexaenoic acid. This release could be blocked by the selective inhibitor of the Ca2+-independent phospholipase A2, 4-bromoenol lactone (10 microM), when it was added 30 min prior to oxygen-glucose deprivation. Addition of 4-bromoenol lactone at 30 min prior to oxygen-glucose deprivation markedly decreased the neuronal damage induced by oxygen-glucose deprivation. The protective effect was substantially higher in dentate gyrus than in CA1 and CA3 areas. Enrichment of the hippocampal tissue with docosahexaenoic acid by incubation with 10 microM docosahexaenoic acid for 24 h exerted the same neuroprotective effect, which was observed after treatment with 4-bromoenol lactone. In contrast to the 24 h-preincubation, simultaneous addition of docosahexaenoic acid with the onset of oxygen-glucose deprivation had no protective effect. This suggests that incorporation of docosahexaenoic acid into phospholipids is required for the protective effect observed. Then the possible involvement of arachidonic acid metabolism in docosahexaenoic acid-induced neuroprotection was tested. Inhibition of prostaglandin production by ibuprofen produced no change in neuroprotection after 24-h incubation of the hippocampal slices with docosahexaenoic acid. Simultaneous inhibition of Ca2+-independent and Ca2+-dependent phospholipases A2 by treatment with the general phospholipase A2 inhibitor methyl arachidonyl fluorophosphonate (3 microM, 30 min prior to oxygen-glucose deprivation

  17. Effects of hnRNP A2/B1 Knockdown on Inhibition of Glioblastoma Cell Invasion, Growth and Survival.

    PubMed

    Deng, Jinmu; Chen, Song; Wang, Feng; Zhao, Hongxin; Xie, Zongyi; Xu, Zhongye; Zhang, Qingtao; Liang, Ping; Zhai, Xuan; Cheng, Yuan

    2016-03-01

    Heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) plays an important role in influence of pre-messenger RNA (pre-mRNA) processing and mRNA metabolism and transportation in cells. Increasing evidence indicates that hnRNP A2/B1 played an important role in development and progression of various human cancers. Forty cases of normal and human glioma tissue samples were analyzed using immunohistochemistry to reveal the expression of hnRNP A2/B1 protein in the samples. Then, knockdown of hnRNP A2/B1 expression induced by RNA interference (RNAi) method was used to analyze the role of hnRNP A2/B1 in glioblastoma cell viability, adhesion, migration, invasion, and chemoresistance for temozolomide (TMZ). The data showed that hnRNP A2/B1 protein was overexpressed in glioma tissue specimens and associated with advanced glioma grades. Knockdown of hnRNP A2/B1 could reduce glioblastoma cell viability, adhesion, migration, invasion, and chemoresistance for TMZ capacity, but induced tumor cells to apoptosis and reactive oxygen species (ROS) generation in glioma U251 and SHG44 cells. Molecularly, hnRNP A2/B1 knockdown reduced expression of phospho-STAT3 and MMP-2. Detection of hnRNP A2/B1 expression may be useful as a biomarker for prediction of glioma progression and knockdown of hnRNP A2/B1 expression as a novel strategy in future control of glioblastoma in clinic.

  18. N1-guanyl-1,7-diaminoheptane enhances the chemosensitivity of NSCLC cells to cetuximab through inhibition of eukaryotic translation initiation factor 5A2 activation.

    PubMed

    Wang, X; Jiang, R; Cui, E-H; Feng, W-M; Guo, H-H; Gu, D-H; Tang, C-W; Xue, T; Bao, Y

    2016-04-01

    N1-guanyl-1, 7-diaminoheptane (GC7), an inhibitor of deoxyhypusine synthase has been shown to exhibit significant anti-cancer activity. However, the biological role of eukaryotic translation initiation factor 5A2 activation (EIF5A2) and GC7 on drug resistance in non-small cell lung cancer (NSCLC) has not been investigated. In this study, we aimed to investigate the therapeutic effect of GC7 combined with cetuximab in NSCLC therapy. The current study used cell viability assays, EdU incorporation assays, and western blot to detect that the GC7 exhibited synergistic cytotoxicity with cetuximab in NSCLC. CCK-8 assays showed that combined treatment with GC7 and cetuximab significantly inhibited the viabilities in three NSCLC cell lines. In addition, EdU incorporation assays also indicated that GC7 co-treatment remarkably enhanced the cetuximab sensitivity in NSCLC cells. Nevertheless, down-regulation of EIF5A2 diminished the regulatory role of GC7 in cetuximab cytotoxicity. Western blot showed that transfection of EIF5A2 siRNA significantly suppressed the protein expression of EIF5A2 in NSCLC cells. These findings demonstrate that combined treatment with GC7 could enhance cetuximab sensitivity by inhibiting EIF5A2 in NSCLC cells, implying the potential clinical application of GC7 in cetuximab-based chemotherapy for NSCLC patients.

  19. Contribution of sortase SrtA2 to Lactobacillus casei BL23 inhibition of Staphylococcus aureus internalization into bovine mammary epithelial cells.

    PubMed

    Souza, Renata F S; Jardin, Julien; Cauty, Chantal; Rault, Lucie; Bouchard, Damien S; Bermúdez-Humarán, Luis G; Langella, Philippe; Monedero, Vicente; Seyffert, Núbia; Azevedo, Vasco; Le Loir, Yves; Even, Sergine

    2017-01-01

    Probiotics have been considered as a promising strategy to prevent various diseases in both humans and animals. This approach has gained interest in recent years as a potential means to control bovine mastitis. In a previous study, we found that several L. casei strains, including BL23, were able to inhibit the internalization of S. aureus, a major etiologic agent of mastitis, into bovine mammary epithelial cells (bMEC). This antagonism required a direct contact between L. casei and bMEC or S. aureus, suggesting the inhibition relied on interactions between L. casei cell surface components and bMEC. In this study, we have investigated the impact of some candidates which likely influence bacteria host cell interactions. We have shown that L. casei BL23 fbpA retained its inhibitory potential, indicating that L. casei BL23 antagonism did not rely (solely) on competition between S. aureus and L. casei fibronectin-binding proteins for adhesion to bMEC. We have then investigated the impact of four sortase mutants, srtA1, srtA2, srtC1 and srtC2, and a double mutant (srtA1-srtA2) on L. casei BL23 inhibitory potential. Sortases are responsible for the anchoring on the bacterial cell wall of LPXTG-proteins, which reportedly play an important role in bacteria-host cell interaction. All the srt mutants tested presented a reduced inhibition capacity, the most pronounced effect being observed with the srtA2 mutant. A lower internalization capacity of L. casei srtA2 into bMEC was also observed. This was associated with several changes at the surface of L. casei BL23 srtA2 compared to the wild type (wt) strain, including altered abundance of some LPXTG- and moonlighting proteins, and modifications of cell wall structure. These results strongly support the role of sortase A2 in L. casei BL23 inhibition against S. aureus internalization. Deciphering the contribution of the cell surface components altered in srtA2 strain in the inhibition will require further investigation.

  20. Contribution of sortase SrtA2 to Lactobacillus casei BL23 inhibition of Staphylococcus aureus internalization into bovine mammary epithelial cells

    PubMed Central

    Souza, Renata F. S.; Jardin, Julien; Cauty, Chantal; Rault, Lucie; Bouchard, Damien S.; Bermúdez-Humarán, Luis G.; Langella, Philippe; Monedero, Vicente; Seyffert, Núbia; Azevedo, Vasco; Le Loir, Yves

    2017-01-01

    Probiotics have been considered as a promising strategy to prevent various diseases in both humans and animals. This approach has gained interest in recent years as a potential means to control bovine mastitis. In a previous study, we found that several L. casei strains, including BL23, were able to inhibit the internalization of S. aureus, a major etiologic agent of mastitis, into bovine mammary epithelial cells (bMEC). This antagonism required a direct contact between L. casei and bMEC or S. aureus, suggesting the inhibition relied on interactions between L. casei cell surface components and bMEC. In this study, we have investigated the impact of some candidates which likely influence bacteria host cell interactions. We have shown that L. casei BL23 fbpA retained its inhibitory potential, indicating that L. casei BL23 antagonism did not rely (solely) on competition between S. aureus and L. casei fibronectin-binding proteins for adhesion to bMEC. We have then investigated the impact of four sortase mutants, srtA1, srtA2, srtC1 and srtC2, and a double mutant (srtA1-srtA2) on L. casei BL23 inhibitory potential. Sortases are responsible for the anchoring on the bacterial cell wall of LPXTG-proteins, which reportedly play an important role in bacteria-host cell interaction. All the srt mutants tested presented a reduced inhibition capacity, the most pronounced effect being observed with the srtA2 mutant. A lower internalization capacity of L. casei srtA2 into bMEC was also observed. This was associated with several changes at the surface of L. casei BL23 srtA2 compared to the wild type (wt) strain, including altered abundance of some LPXTG- and moonlighting proteins, and modifications of cell wall structure. These results strongly support the role of sortase A2 in L. casei BL23 inhibition against S. aureus internalization. Deciphering the contribution of the cell surface components altered in srtA2 strain in the inhibition will require further investigation. PMID

  1. Activation of the thromboxane A2 receptor by 8-isoprostane inhibits the pro-angiogenic effect of vascular endothelial growth factor in scleroderma

    PubMed Central

    Tsou, Pei-Suen; Amin, M. Asif; Campbell, Phil; Zakhem, George; Balogh, Beatrix; Edhayan, Gautam; Ohara, Ray A.; Schiopu, Elena; Khanna, Dinesh; Koch, Alisa E.; Fox, David A.

    2015-01-01

    The pathogenesis of scleroderma (SSc) includes components of autoimmunity, vascular dysfunction, and accumulation of extracellular matrix. 8-isoprostane, an oxidized lipid created by oxidative stress, activates the thromboxane A2 receptor (TXAR) and ROCK pathway. In this study we determined whether the TXAR was activated by 8-isoprostane in SSc endothelial cells (ECs), and whether this pathway inhibited VEGF-induced angiogenesis. Elevated 8-isoprostane was observed in plasma and conditioned media from SSc patients. SSc conditioned media inhibited EC tube formation, while addition of vitamin E, by reducing 8-isoprostane, increased tube formation. VEGF did not induce angiogenesis in SSc ECs, but vitamin E or TXAR inhibition restored its effect. The expression of TXAR, RhoA, and ROCK1/2 were elevated in SSc ECs. ROCK activity and 8-isoprostane-induced ROCK activation were significantly higher in SSc ECs while VEGF had no effect. The hyper-activation of the TXAR leads to inhibition of VEGF-induced angiogenesis, as inhibition of the TXAR pathway results in blockade of 8-isoprostane induced ROCK activation and restoration of VEGF activity. These results suggest that the TXAR pathway plays a crucial role in angiogenesis and that 8-isoprostane is not just a by-product of oxidative stress, but also plays a significant role in the impaired angiogenesis that characterizes SSc. PMID:26288351

  2. Inhibition of Baicalin on Metabolism of Phenacetin, a Probe of CYP1A2, in Human Liver Microsomes and in Rats

    PubMed Central

    Gao, Na; Qi, Bing; Liu, Fang-jun; Fang, Yan; Zhou, Jun; Jia, Lin-jing; Qiao, Hai-ling

    2014-01-01

    Baicalin has been used as mainly bioactive constituent of about 100 kinds of traditional Chinese medicines in Chinese pharmacopoeia. The effect of baicalin on cytochrome P450 should be paid more attention because baicalin was used widely. The aim of this study was to investigate whether baicalin could inhibit CYP1A2 in pooled human liver microsomes (HLMs) and in rats in vivo and the gene polymorphisms could affect inter-individual variation in IC50 in 28 human livers. Phenacetin was used as probe of CYP1A2. Kinetic parameter of CYP1A2 and IC50 of baicalin on CYP1A2 to each sample were measured and the common CYP1A2 polymorphisms (−3860G>A and −163C>A) were genotyped. The results showed that baicalin exhibited a mixed-type inhibition in pooled HLMs, with a Ki value of 25.4 µM. There was substantial variation in Km, Vmax, CLint of CYP1A2 and IC50 of baicalin on CYP1A2 (3∼10-fold). The range was from 26.6 to 114.8 µM for Km, from 333 to 1330 pmol·min−1·mg−1protein for Vmax and from 3.8 to 45.3 µL·min−1·mg−1 protein for CLint in HLMs (n = 28). The Mean (range) value of IC50 in 28 HLMs was 36.3 (18.9 to 56.1) µM. The genotypes of −3860G>A and −163C>A had no significant effect on the inhibition of baicalin on CYP1A2. The animal experiment results showed that baicalin (450 mg/kg, i.v.) significantly decreased the Cmax and CL of phenacetin, and increased C60 min, t1/2, Vd and AUC (P<0.05). There were significant correlations between percentage of control in C60 min, t1/2, CL, AUC of phenacetin and Cmax of baicalin in 11 rats (P<0.05). Protein binding experiments in vitro showed that baicalin (0–2000 mg/L) increased the unbound phenacetin from 14.5% to 28.3%. In conclusion, baicalin can inhibit the activity of CYP1A2 in HLMs and exhibit large inter-individual variation that has no relationship with gene polymorphism. Baicalin can change the pharmacokinetics of phenacetin in rats. PMID:24587011

  3. Inhibition of gingipains by their profragments as the mechanism protecting Porphyromonas gingivalis against premature activation of secreted proteases

    PubMed Central

    Veillard, Florian; Sztukowska, Maryta; Mizgalska, Danuta; Ksiazek, Mirosław; Houston, John; Potempa, Barbara; Enghild, Jan J.; Thogersen, Ida B.; Gomis-Rüth, F. Xavier; Nguyen, Ky-Anh; Potempa, Jan

    2013-01-01

    Background Arginine-specific (RgpB and RgpA) and lysine-specific (Kgp) gingipains are secretory cysteine proteinases of Porphyromonas gingivalis that act as important virulence factors for the organism. They are translated as zymogens with both N- and C-terminal extensions, which are proteolytically cleaved during secretion. In this report, we describe and characterize inhibition of the gingipains by their N-terminal prodomains to maintain latency during their export through the cellular compartments. Methods Recombinant forms of various prodomains (PD) were analyzed for their interaction with mature gingipains. The kinetics of their inhibition of proteolytic activity along with the formation of stable inhibitory complexes with native gingipains was studied by gel filtration, native PAGE and substrate hydrolysis. Results PDRgpB and PDRgpA formed tight complexes with arginine-specific gingipains (Ki in the range from 6.2 nM to 0.85 nM). In contrast, PDKgp showed no inhibitory activity. A conserved Arg-102 residue in PDRgpB and PDRgpA was recognized as the P1 residue. Mutation of Arg-102 to Lys reduced inhibitory potency of PDRgpB by one order of magnitude while its substitutions with Ala, Gln or Gly totally abolished the PD inhibitory activity. Covalent modification of the catalytic cysteine with tosyl-L-Lys-chloromethylketone (TLCK) or H-D-Phe-Arg-chloromethylketone did not affect formation of the stable complex. Conclusion Latency of arginine-specific progingipains is efficiently exerted by N-terminal prodomains thus protecting the periplasm from potentially damaging effect of prematurely activated gingipains. General significance Blocking progingipain activation may offer an attractive strategy to attenuate P. gingivalis pathogenicity. PMID:23583629

  4. Silibinin protects H9c2 cardiac cells from oxidative stress and inhibits phenylephrine-induced hypertrophy: potential mechanisms.

    PubMed

    Anestopoulos, Ioannis; Kavo, Anthula; Tentes, Ioannis; Kortsaris, Alexandros; Panayiotidis, Mihalis; Lazou, Antigone; Pappa, Aglaia

    2013-03-01

    Cardiac hypertrophy is the main response of the heart to various extrinsic and intrinsic stimuli, and it is characterized by specific molecular and phenotypic changes. Recent in vitro and in vivo studies indicate the involvement of reactive oxygen species in the hypertrophic response. In this study, silibinin, a plant flavonolignan extracted from milk thistle with potent antioxidant activity, was evaluated for its effects in (a) preventing hydrogen peroxide (H2O2)-induced cellular damage and (b) blocking the phenylephrine-induced hypertrophic response. Using the in vitro model of embryonic rat heart-derived H9c2 cells, we showed that silibinin has a rather safe profile as concentrations up to 200μM did not affect cell viability. Pretreatment of H9c2 cells with silibinin resulted in better protection of H9c2 cells under conditions of H2O2-induced cellular stress compared to untreated cells as indicated by cell viability and DNA fragmentation assays. Furthermore, silibinin attenuated the phenylephrine-induced hypertrophic response as evidenced by the measurement of cell surface, up-regulation of atrial natriuretic peptide and increase of cellular protein levels. Moreover, silibinin repressed the phenylephrine-induced phosphorylation of ERK1/2 kinases, while it appeared to inhibit the weakly activated by phenylephrine phosphorylation of Akt. Based on our results, silibinin may attenuate the phenylephrine-induced hypertrophic response of H9c2 cells via antioxidant mechanisms involving mainly the inhibition of the intracellular signaling pathways mediated by ERK1/2 MAPKs and Akt.

  5. Tetramethyl Pyrazine Protects Hippocampal Neurons Against Anoxia/Reoxygenation Injury Through Inhibiting Apoptosis Mediated by JNK/MARK Signal Pathway

    PubMed Central

    Zhong, Ming; Ma, Wuhua; Zhang, Xiong; Wang, Yong; Gao, Xiaoqiu

    2016-01-01

    Background Tetramethyl pyrazine (TMP) is a typical biologically active alkaloid isolated from the Chinese herb Ligusticum walliichi. It has been reported that TMP shows neuroprotective and stroke injury reductive properties in cerebral ischemia/reperfusion (I/R) animal models. In the present study we sought to investigate the effect and potential intervention mechanism of TMP in anoxia/reoxygenation (A/R) rat hippocampal neurons. Material/Methods After being cultured for 7 days, primary hippocampal neurons were randomly assigned into a normal control group (N), a TMP group (C: 0 ug/ml, L: 60 ug/ml, M: 200ug/ml and H: 800 ug/ml), and a JNK inhibitor group (S: SP600125, 10 μmol/L). A hypoxia/reoxygenation model were prepared 1 h after incubation. Hippocampal neurons were incubated in 90% N2 and 10% CO2 for 2 h, and then reoxygenated for 24 h in an incubator with 5%CO2 at the temperature of 37°C. The apoptosis rate, MKK4 and MKK7 mRNA and JNK kinase protein levels (C-fos, c-jun, and P-JNK) of hippocampal neurons were detected. Results The apoptosis rates of hippocampal neurons induced by A/R showed significant reduction after being pre-treated with JNK inhibitor, TMP 60 μg/ml, 200 μg/ml, and 800 μg/ml. The JNK kinase MKK4mRNA and MKK7mRNA levels, as well as the expressions of C-fos, C-jun, and P-JNK protein levels, were also be reduced. Conclusions TMP may produce a protective effect in anoxia/reoxygenation-induced primary hippocampal neuronal injury by inhibiting the apoptosis of the hippocampal neurons; the possible mechanism may be inhibition of the JNK signal pathway. PMID:28009855

  6. Tetramethyl Pyrazine Protects Hippocampal Neurons Against Anoxia/Reoxygenation Injury Through Inhibiting Apoptosis Mediated by JNK/MARK Signal Pathway.

    PubMed

    Zhong, Ming; Ma, Wuhua; Zhang, Xiong; Wang, Yong; Gao, Xiaoqiu

    2016-12-23

    BACKGROUND Tetramethyl pyrazine (TMP) is a typical biologically active alkaloid isolated from the Chinese herb Ligusticum walliichi. It has been reported that TMP shows neuroprotective and stroke injury reductive properties in cerebral ischemia/reperfusion (I/R) animal models. In the present study we sought to investigate the effect and potential intervention mechanism of TMP in anoxia/reoxygenation (A/R) rat hippocampal neurons. MATERIAL AND METHODS After being cultured for 7 days, primary hippocampal neurons were randomly assigned into a normal control group (N), a TMP group (C: 0 ug/ml, L: 60 ug/ml, M: 200ug/ml and H: 800 ug/ml), and a JNK inhibitor group (S: SP600125, 10 μmol/L). A hypoxia/reoxygenation model were prepared 1 h after incubation. Hippocampal neurons were incubated in 90% N2 and 10% CO2 for 2 h, and then reoxygenated for 24 h in an incubator with 5%CO2 at the temperature of 37°C. The apoptosis rate, MKK4 and MKK7 mRNA and JNK kinase protein levels (C-fos, c-jun, and P-JNK) of hippocampal neurons were detected. RESULTS The apoptosis rates of hippocampal neurons induced by A/R showed significant reduction after being pre-treated with JNK inhibitor, TMP 60 µg/ml, 200 µg/ml, and 800 µg/ml. The JNK kinase MKK4mRNA and MKK7mRNA levels, as well as the expressions of C-fos, C-jun, and P-JNK protein levels, were also be reduced. CONCLUSIONS TMP may produce a protective effect in anoxia/reoxygenation-induced primary hippocampal neuronal injury by inhibiting the apoptosis of the hippocampal neurons; the possible mechanism may be inhibition of the JNK signal pathway.

  7. Inhibition of ileal bile acid uptake protects against nonalcoholic fatty liver disease in high-fat diet-fed mice.

    PubMed

    Rao, Anuradha; Kosters, Astrid; Mells, Jamie E; Zhang, Wujuan; Setchell, Kenneth D R; Amanso, Angelica M; Wynn, Grace M; Xu, Tianlei; Keller, Brad T; Yin, Hong; Banton, Sophia; Jones, Dean P; Wu, Hao; Dawson, Paul A; Karpen, Saul J

    2016-09-21

    Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the Western world, and safe and effective therapies are needed. Bile acids (BAs) and their receptors [including the nuclear receptor for BAs, farnesoid X receptor (FXR)] play integral roles in regulating whole-body metabolism and hepatic lipid homeostasis. We hypothesized that interruption of the enterohepatic BA circulation using a luminally restricted apical sodium-dependent BA transporter (ASBT) inhibitor (ASBTi; SC-435) would modify signaling in the gut-liver axis and reduce steatohepatitis in high-fat diet (HFD)-fed mice. Administration of this ASBTi increased fecal BA excretion and messenger RNA (mRNA) expression of BA synthesis genes in liver and reduced mRNA expression of ileal BA-responsive genes, including the negative feedback regulator of BA synthesis, fibroblast growth factor 15. ASBT inhibition resulted in a marked shift in hepatic BA composition, with a reduction in hydrophilic, FXR antagonistic species and an increase in FXR agonistic BAs. ASBT inhibition restored glucose tolerance, reduced hepatic triglyceride and total cholesterol concentrations, and improved NAFLD activity score in HFD-fed mice. These changes were associated with reduced hepatic expression of lipid synthesis genes (including liver X receptor target genes) and normalized expression of the central lipogenic transcription factor, Srebp1c Accumulation of hepatic lipids and SREBP1 protein were markedly reduced in HFD-fed Asbt(-/-) mice, providing genetic evidence for a protective role mediated by interruption of the enterohepatic BA circulation. Together, these studies suggest that blocking ASBT function with a luminally restricted inhibitor can improve both hepatic and whole body aspects of NAFLD.

  8. A colonisation-inhibition culture consisting of Salmonella Enteritidis and Typhimurium ΔhilAssrAfliG strains protects against infection by strains of both serotypes in broilers.

    PubMed

    De Cort, W; Mot, D; Haesebrouck, F; Ducatelle, R; Van Immerseel, F

    2014-08-06

    Consumption of contaminated poultry meat is still an important cause of Salmonella infections in humans and there is a need for control methods that protect broilers from day-of-hatch until slaughter age against infection with Salmonella. Colonisation-inhibition, a concept in which a live Salmonella strain is orally administered to day-old chickens and protects against subsequent challenge, can potentially be used as control method. In this study, the efficacy of a Salmonella Typhimurium ΔhilAssrAfliG strain as a colonisation-inhibition strain for protection of broilers against Salmonella Typhimurium was evaluated. Administration of a Salmonella Typhimurium ΔhilAssrAfliG strain to day-old broiler chickens decreased faecal shedding and strongly reduced caecal and internal organ colonisation of a Salmonella Typhimurium challenge strain administered one day later using a seeder bird model. In addition, it was verified whether a colonisation-inhibition culture could be developed that protects against both Salmonella Enteritidis and Typhimurium. Therefore, the Salmonella Typhimurium ΔhilAssrAfliG strain was orally administered simultaneously with a Salmonella Enteritidis ΔhilAssrAfliG strain to day-old broiler chickens, which resulted in a decreased caecal and internal organ colonisation for both a Salmonella Enteritidis and a Salmonella Typhimurium challenge strain short after hatching, using a seeder bird model. The combined culture was not protective against Salmonella Paratyphi B varietas Java challenge, indicating serotype-specific protection mechanisms. The data suggest that colonisation-inhibition can potentially be used as a versatile control method to protect poultry against several Salmonella serotypes.

  9. EphrinA1-EphA2 interaction-mediated apoptosis and Flt3L-induced immunotherapy inhibits tumor growth in a breast cancer mouse model

    PubMed Central

    Tandon, Manish; Vemula, Sai V.; Sharma, Anurag; Ahi, Yadvinder S.; Mittal, Shalini; Bangari, Dinesh S.; Mittal, Suresh K.

    2014-01-01

    Background The receptor tyrosine kinase EphA2 is overexpressed in several types of cancers and is currently being pursued as a target for breast cancer therapeutics. The EphA2 ligand EphrinA1 induces EphA2 phosphorylation and intracellular internalization and degradation, thus inhibiting tumor progression. The hematopoietic growth factor, FMS-like tyrosine kinase receptor ligand (Flt3L), promotes expansion and mobilization of functional dendritic cells. Methods We tested the EphrinA1-EphA2 interaction in MDA-MB-231 breast cancer cells focusing on the receptor-ligand-mediated apoptosis of breast cancer cells. In order to determine whether the EphrinA1-EphA2 interaction-associated apoptosis and Flt3L-mediated immunotherapy would have an additive effect in inhibiting tumor growth, we used an immunocompetent mouse model of breast cancer to evaluate intratumoral (i.t.) inoculation strategies with human adenovirus (HAd) vectors expressing either EphrinA1 (HAd-EphrinA1-Fc), Flt3L (HAd-Flt3L) or a combination of EphrinA1-Fc + Flt3L (HAd-EphrinA1-Fc + HAd-Flt3L). Results In vitro analysis demonstrated that an EphrinA1-EphA2 interaction led to apoptosis-related changes in breast cancer cells. In vivo, three i.t. inoculations of HAd-EphrinA1-Fc showed potent inhibition of tumor growth. Furthermore, increased inhibition in tumor growth was observed with the combination of HAd-EphrinA1-Fc and HAd-Flt3L accompanied by the generation of an anti-tumor adaptive immune response. Conclusions The results indicating induction of apoptosis and inhibition of mammary tumor growth show the potential therapeutic benefits of HAd-EphrinA1-Fc. In combination with HAd-Flt3L, this represents a promising strategy to effectively induce mammary tumor regression by HAd vector-based therapy. PMID:22228563

  10. Endogenous prostaglandin endoperoxides and prostacyclin modulate the thrombolytic activity of tissue plasminogen activator. Effects of simultaneous inhibition of thromboxane A2 synthase and blockade of thromboxane A2/prostaglandin H2 receptors in a canine model of coronary thrombosis.

    PubMed Central

    Golino, P; Rosolowsky, M; Yao, S K; McNatt, J; De Clerck, F; Buja, L M; Willerson, J T

    1990-01-01

    We tested the hypothesis that simultaneous inhibition of TxA2 synthase and blockade of TxA2/PHG2 receptors is more effective in enhancing thrombolysis and preventing reocclusion after discontinuation of tissue plasminogen activator (t-PA) than either intervention alone. Coronary thrombosis was induced in 35 dogs by placing a copper coil into the left anterior descending coronary artery. Coronary flow was measured with a Doppler flow probe. 30 min after thrombus formation, the animals received saline (controls, n = 10); SQ 29548 (0.4 mg/kg bolus + 0.4 mg/kg per h infusion), a TxA2/PGH2 receptor antagonist (n = 8); dazoxiben (5 mg/kg bolus + 5 mg/kg per h infusion), a TxA2 synthase inhibitor (n = 9); or R 68070 (5 mg/kg bolus + 5 mg/kg per h infusion), a drug that blocks TxA2/PGH2 receptors and inhibits TxA2 synthase (n = 8). Then, all dogs received heparin (200 U/kg) and a bolus of t-PA (80 micrograms/kg) followed by a continuous infusion (8 micrograms/kg per min) for up to 90 min or until reperfusion was achieved. The time to thrombolysis did not change significantly in SQ 29548-treated dogs as compared with controls (42 +/- 5 vs. 56 +/- 7 min, respectively, P = NS), but it was significantly shortened by R 68070 and dazoxiben (11 +/- 2 and 25 +/- 6 min, respectively, P less than 0.001 vs. controls and SQ 29548-treated dogs). R 68070 administration resulted in a lysis time significantly shorter than that observed in the dazoxiben-treated group (P less than 0.01). Reocclusion was observed in eight of eight control dogs, five of seven SQ 29548-treated dogs, seven of nine dazoxiben-treated dogs, and zero of eight R 68070-treated animals (P less than 0.001). TxB2 and 6-keto-PGF1 alpha, measured in blood samples obtained from the coronary artery distal to the thrombus, were significantly increased at reperfusion and at reocclusion in control animals and in dogs receiving SQ 29548. R 68070 and dazoxiben prevented the increase in plasma TxB2 levels, whereas 6-keto-PGF1

  11. Pharmacological inhibition of PAR2 with the pepducin P2pal-18S protects mice against acute experimental biliary pancreatitis.

    PubMed

    Michael, E S; Kuliopulos, A; Covic, L; Steer, M L; Perides, G

    2013-03-01

    Pancreatic acinar cells express proteinase-activated receptor-2 (PAR2) that is activated by trypsin-like serine proteases and has been shown to exert model-specific effects on the severity of experimental pancreatitis, i.e., PAR2(-/-) mice are protected from experimental acute biliary pancreatitis but develop more severe secretagogue-induced pancreatitis. P2pal-18S is a novel pepducin lipopeptide that targets and inhibits PAR2. In studies monitoring PAR2-stimulated intracellular Ca(2+) concentration changes, we show that P2pal-18S is a full PAR2 inhibitor in acinar cells. Our in vivo studies show that P2pal-18S significantly reduces the severity of experimental biliary pancreatitis induced by retrograde intraductal bile acid infusion, which mimics injury induced by endoscopic retrograde cholangiopancreatography (ERCP). This reduction in pancreatitis severity is observed when the pepducin is given before or 2 h after bile acid infusion but not when it is given 5 h after bile acid infusion. Conversely, P2pal-18S increases the severity of secretagogue-induced pancreatitis. In vitro studies indicate that P2pal-18S protects acinar cells against bile acid-induced injury/death, but it does not alter bile acid-induced intracellular zymogen activation. These studies are the first to report the effects of an effective PAR2 pharmacological inhibitor on pancreatic acinar cells and on the severity of experimental pancreatitis. They raise the possibility that a pepducin such as P2pal-18S might prove useful in the clinical management of patients at risk for developing severe biliary pancreatitis such as occurs following ERCP.

  12. Protection of hearts from reperfusion injury by propofol is associated with inhibition of the mitochondrial permeability transition.

    PubMed

    Javadov, S A; Lim, K H; Kerr, P M; Suleiman, M S; Angelini, G D; Halestrap, A P

    2000-01-14

    Diminishing oxidative stress may protect the heart against ischaemia-reperfusion injury by preventing opening of the mitochondrial permeability transition (MPT) pore. The general anaesthetic agent propofol, a free radical scavenger, has been investigated for its effect on the MPT and its cardioprotective action following global and cardioplegic ischaemic arrest. Isolated perfused Wistar rat hearts were subjected to either warm global ischaemia (Langendorff) or cold St. Thomas' cardioplegia (working heart mode) in the presence or absence of propofol. MPT pore opening was determined using [3H]-2-deoxyglucose-6-phosphate ([3H]-DOG-6P) entrapment. The respiratory function of isolated mitochondria was also determined for evidence of oxidative stress. Propofol (2 micrograms/ml) significantly improved the functional recovery of Langendorff hearts on reperfusion (left ventricular developed pressure from 28.4 +/- 6.2 to 53.3 +/- 7.3 mmHg and left ventricular end diastolic pressure from 52.9 +/- 4.3 to 37.5 +/- 3.9 mmHg). Recovery was also improved in propofol (4 micrograms/ml) treated working hearts following cold cardioplegic arrest. External cardiac work on reperfusion improved from 0.42 +/- 0.05 to 0.60 +/- 0.03 J/s, representing 45-64% of baseline values, when compared to controls (P < 0.05). Propofol inhibited MPT pore opening during reperfusion, [3H]-DOG-6P entrapment being 16.7 vs. 22.5 ratio units in controls (P < 0.05). Mitochondria isolated from non-ischaemic, propofol-treated hearts exhibited increased respiratory chain activity and were less sensitive to calcium-induced MPT pore opening. Propofol confers significant protection against global normothermic ischaemia and during cold cardioplegic arrest. This effect is associated with less opening of mitochondrial MPT pores, probably as a result of diminished oxidative stress. Propofol may be a useful adjunct to cardioplegic solutions in heart surgery.

  13. Pharmacological inhibition of PAR2 with the pepducin P2pal-18S protects mice against acute experimental biliary pancreatitis

    PubMed Central

    Michael, E. S.; Kuliopulos, A.; Covic, L.; Steer, M. L.

    2013-01-01

    Pancreatic acinar cells express proteinase-activated receptor-2 (PAR2) that is activated by trypsin-like serine proteases and has been shown to exert model-specific effects on the severity of experimental pancreatitis, i.e., PAR2−/− mice are protected from experimental acute biliary pancreatitis but develop more severe secretagogue-induced pancreatitis. P2pal-18S is a novel pepducin lipopeptide that targets and inhibits PAR2. In studies monitoring PAR2-stimulated intracellular Ca2+ concentration changes, we show that P2pal-18S is a full PAR2 inhibitor in acinar cells. Our in vivo studies show that P2pal-18S significantly reduces the severity of experimental biliary pancreatitis induced by retrograde intraductal bile acid infusion, which mimics injury induced by endoscopic retrograde cholangiopancreatography (ERCP). This reduction in pancreatitis severity is observed when the pepducin is given before or 2 h after bile acid infusion but not when it is given 5 h after bile acid infusion. Conversely, P2pal-18S increases the severity of secretagogue-induced pancreatitis. In vitro studies indicate that P2pal-18S protects acinar cells against bile acid-induced injury/death, but it does not alter bile acid-induced intracellular zymogen activation. These studies are the first to report the effects of an effective PAR2 pharmacological inhibitor on pancreatic acinar cells and on the severity of experimental pancreatitis. They raise the possibility that a pepducin such as P2pal-18S might prove useful in the clinical management of patients at risk for developing severe biliary pancreatitis such as occurs following ERCP. PMID:23275617

  14. Inhibition of inflammation mediates the protective effect of atorvastatin reload in patients with coronary artery disease undergoing noncardiac emergency surgery.

    PubMed

    Qu, Yang; Wei, Lixin; Zhang, Haiqing

    2014-12-01

    This study aimed to (a) investigate whether atorvastatin reload protects against acute heart failure (AHF) in patients with stable coronary artery disease (CAD) undergoing noncardiac emergency surgery and decreases the incidence of major adverse cardiac events (MACE) during hospitalization and (b) elucidate its possible mechanism of action. In total, 500 patients with stable CAD before noncardiac emergency surgery were randomized either to the atorvastatin reload or to the placebo group. All patients received atorvastatin treatment postoperatively. The primary end point was the incidence of AHF during hospitalization, and the secondary end point was the incidence of MACE during hospitalization. Preoperative and 72 h postoperative changes in high-sensitivity C-reactive protein and interleukin-6 levels were compared between the two groups. AHF during hospitalization occurred in 5.2% of patients in the atorvastatin reload group and 11.2% in the placebo group (P=0.0225). MACE during hospitalization occurred in 2.4% of patients in the atorvastatin reload group and 8.0% in the placebo group (P=0.0088). According to multivariable analysis, atorvastatin reload conferred a 50% reduction in the risk of AHF during hospitalization (odds ratio, 0.50; 95% confidence interval, 0.2-0.8; P=0.005). The median decrease in the high-sensitivity C-reactive protein and interleukin-6 levels was significantly greater in the atorvastatin reload group (P<0.001). Atorvastatin reload may improve the clinical outcome of patients with stable CAD undergoing noncardiac emergency surgery by decreasing the incidence of AHF and MACE during hospitalization. The mechanism of this protective effect may involve inhibition of inflammation.

  15. Ethyl pyruvate protects rats from phosgene-induced pulmonary edema by inhibiting cyclooxygenase2 and inducible nitric oxide synthase expression.

    PubMed

    Chen, Hong-li; Bai, Hua; Xi, Miao-miao; Liu, Riu; Qin, Xu-jun; Liang, Xin; Zhang, Wei; Zhang, Xiao-di; Li, Wen-li; Hai, Chun-xu

    2013-01-01

    Phosgene is a poorly water-soluble gas penetrating the lower respiratory tract which can induce acute lung injury characterized by a latent phase of fatal pulmonary edema. Pulmonary edema caused by phosgene is believed to be a consequence of oxidative stress and inflammatory responses. Ethyl pyruvate (EP) has been demonstrated to have anti-inflammatory and anti-oxidative properties in vivo and in vitro. The potential therapeutic role of EP in phosgene-induced pulmonary edema has not been addressed so far. In the present study, we aim to investigate the protective effects of EP on phosgene-induced pulmonary edema and the underlying mechanisms. Rats were administered with EP (40 mg kg(-1)) and RAW264.7 cells were also incubated with it (0, 2, 5 or 10 µm) immediately after phosgene (400 ppm, 1 min) or air exposure. Wet-to-dry lung weight ratio (W:D ratio), nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production, cyclooxygenase2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, and mitogen-activated protein kinases activities (MAPKs) were measured. Our results showed that EP treatment attenuated phosgene-induced pulmonary edema and decreased the level of NO and PGE(2) dose-dependently. Furthermore, EP significantly reduced COX-2 expression, iNOS expression and MAPK activation induced by phosgene. Moreover, specific inhibitors of MAPKs reduced COX-2 and iNOS expression induced by phosgene. These findings suggested that EP has a protective role against phosgene-induced pulmonary edema, which is mediated in part by inhibiting MAPK activation and subsequently down-regulating COX-2 and iNOS expression as well as decreasing the production of NO and PGE(2). Copyright © 2011 John Wiley & Sons, Ltd.

  16. Inhibition of microRNA-31-5p protects human colonic epithelial cells against ionizing radiation

    NASA Astrophysics Data System (ADS)

    Kim, Sang Bum; Zhang, Lu; Barron, Summer; Shay, Jerry W.

    2014-04-01

    MicroRNAs (miRNAs), endogenous non-coding small RNAs, are sensitive to environmental changes, and their differential expression is important for adaptation to the environment. However, application of miRNAs as a clinical prognostic or diagnostic tool remains unproven. In this study we demonstrate a chronic/persistent change of miRNAs from the plasma of a colorectal cancer susceptible mouse model (CPC;Apc) about 250 days after exposure to a simulated solar particle event (SPE). Differentially expressed miRNAs were identified compared to unirradiated control mice, including miR-31-5p, which we investigated further. To address the cellular function of miR-31-5p, we transfected a miR-31-5p mimic (sense) or inhibitor (antisense) into immortalized human colonic epithelial cells followed by gamma-irradiation. A miR-31-5p mimic sensitized but a miR-31-5p inhibitor protected colonic epithelial cells against radiation induced killing. We found that the miR-31-5p mimic inhibited the induction of hMLH1 expression after irradiation, whereas the miR-31-5p inhibitor increased the basal level of hMLH1 expression. The miR-31-5p inhibitor failed to modulate radiosensitivity in an hMLH1-deficient HCT116 colon cancer cell line but protected HCT116 3-6 and DLD-1 (both hMLH1-positive) colon cancer cell lines. Our findings demonstrate that miR-31-5p has an important role in radiation responses through regulation of hMLH1 expression. Targeting this pathway could be a promising therapeutic strategy for future personalized anti-cancer radiotherapy.

  17. alpha-Linolenic acid protects renal cells against palmitic acid lipotoxicity via inhibition of endoplasmic reticulum stress.

    PubMed

    Katsoulieris, Elias; Mabley, Jon G; Samai, Mohamed; Green, Irene C; Chatterjee, Prabal K

    2009-11-25

    Unsaturated fatty acids may counteract the lipotoxicity associated with saturated fatty acids. Palmitic acid induced endoplasmic reticulum (ER) stress and caused apoptotic and necrotic cell death in the renal proximal tubular cell line, NRK-52E. We investigated whether alpha-linolenic acid, an unsaturated fatty acid, protected against ER stress and cell death induced by palmitic acid or by other non-nutrient ER stress generators. Incubation of NRK-52E cells for 24h with palmitic acid produced a significant increase in apoptosis and necrosis. Palmitic acid also increased levels of three indicators of ER stress - the phosphorylated form of the eukaryotic initiation factor 2alpha (eIF2alpha), C/EBP homologous protein (CHOP), and glucose regulated protein 78 (GRP78). alpha-Linolenic acid dramatically reduced cell death and levels of all three indicators of ER stress brought about by palmitic acid. Tunicamycin, which induces ER stress by glycosylation of proteins, produced similar effects to those obtained using palmitic acid; its effects were partially reversed by alpha-linolenic acid. Salubrinal (a phosphatase inhibitor) causes increased levels of the phosphorylated form of eIF2alpha - this effect was partially reversed by alpha-linolenic acid. Palmitoleate, a monosaturated fatty acid, had similar effects to those of alpha-linolenic acid. These results suggest that part of the mechanism of protection of the kidney by unsaturated fatty acids is through inhibition of ER stress, eIF2alpha phosphorylation and consequential reduction of CHOP protein expression and apoptotic renal cell death.

  18. Curcumin protects against lipopolysaccharide-induced vasoconstriction dysfunction via inhibition of thrombospondin-1 and transforming growth factor-β1

    PubMed Central

    LU, WEI; JIANG, JIAN-PING; HU, JUE; WANG, JUE; ZHENG, MING-ZHI

    2015-01-01

    Sepsis is a complex syndrome characterized by the development of progressive dysfunction in multiple organs. The aim of the present study was to investigate the protective effect of curcumin against lipopolysaccharide (LPS)-induced vasoconstrictive dysfunction, and to investigate the possible underlying mechanism. Male Sprague-Dawley rats were randomly divided into the following groups: Control, sepsis and curcumin. A sepsis model was established by an intraperitoneal (i.p.) injection of 5 mg/kg LPS. Thoracic aortic rings obtained from the rats were mounted in an organ bath and the vasoconstriction of the rings was recorded. In addition, the serum E-selectin levels were determined by an enzyme-linked immunosorbent assay. The expression levels of thrombospondin (TSP)-1 and transforming growth factor (TGF)-β1 in the aortic tissue were detected by immunohistochemistry. Vasoconstriction of the aortic rings was found to significantly decrease in the sepsis rats when compared with the control group. However, curcumin (10 or 20 mg/kg, i.p.) prevented the vasoconstrictive dysfunction induced by LPS. The serum level of E-selectin and the expression levels of TSP-1 and TGF-β1 significantly increased in the sepsis rats when compared with the control group rats; however, the levels decreased significantly following treatment with curcumin (10 or 20 mg/kg). Furthermore, hematoxylin and eosin staining revealed that curcumin alleviated the LPS-induced damage in the aortic tunica intima and tunica media. Therefore, the results indicated that curcumin alleviates LPS-induced vasoconstrictive dysfunction in the thoracic aorta of rats. In addition, the inhibition of TSP-1 and TGF-β1 expression may be involved in the mechanism underlying this protective effect. PMID:25574201

  19. Molecular basis for covalent inhibition of glyceraldehyde-3-phosphate dehydrogenase by a 2-phenoxy-1,4-naphthoquinone small molecule.

    PubMed

    Bruno, Stefano; Uliassi, Elisa; Zaffagnini, Mirko; Prati, Federica; Bergamini, Christian; Amorati, Riccardo; Paredi, Gianluca; Margiotta, Marilena; Conti, Paola; Costi, Maria Paola; Kaiser, Marcel; Cavalli, Andrea; Fato, Romana; Bolognesi, Maria Laura

    2017-01-12

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has recently gained attention as an antiprotozoan and anticancer drug target. We have previously identified 2-phenoxy-1,4-naphthoquinone as an inhibitor of both Trypanosoma brucei and human GAPDH. Herein, through multiple chemical, biochemical, and biological studies, and through the design of analogs, we confirmed the formation of a covalent adduct, we clarified the inhibition mechanism, and we demonstrated antitrypanosomal, antiplasmodial, and cytotoxic activities in cell cultures. The overall results lent support to the hypothesis that 2-phenoxy-1,4-naphthoquinone binds the GAPDH catalytic cysteine covalently through a phenolate displacement mechanism. By investigating the reactivity of 2-phenoxy-1,4-naphthoquinone and its analogs with four GAPDH homologs, we showed that the covalent inhibition is not preceded by the formation of a strong non-covalent complex. However, an up to fivefold difference in inactivation rates among homologs hinted at structural or electrostatic differences of their active sites that could be exploited to further design kinetically selective inhibitors. Moreover, we preliminarily showed that 2-phenoxy-1,4-naphthoquinone displays selectivity for GAPDHs over two other cysteine-dependent enzymes, supporting its suitability as a warhead starting fragment for the design of novel inhibitors.

  20. PAR1 inhibition suppresses the self-renewal and growth of A2B5-defined glioma progenitor cells and their derived gliomas in vivo

    PubMed Central

    Auvergne, R; Wu, C; Connell, A; Au, S; Cornwell, A; Osipovitch, M; Benraiss, A; Dangelmajer, S; Guerrero-Cazares, H; Quinones-Hinojosa, A; Goldman, SA

    2016-01-01

    Glioblastoma (GBM) remains the most common and lethal intracranial tumor. In a comparison of gene expression by A2B5-defined tumor-initiating progenitor cells (TPCs) to glial progenitor cells derived from normal adult human brain, we found that the F2R gene encoding PAR1 was differentially overexpressed by A2B5-sorted TPCs isolated from gliomas at all stages of malignant development. In this study, we asked if PAR1 is causally associated with glioma progression. Lentiviral knockdown of PAR1 inhibited the expansion and self-renewal of human GBM-derived A2B5+ TPCs in vitro, while pharmacological inhibition of PAR 1 similarly slowed both the growth and migration of A2B5+ TPCs in culture. In addition, PAR1 silencing potently suppressed tumor expansion in vivo, and significantly prolonged the survival of mice following intracranial transplantation of human TPCs. These data strongly suggest the importance of PAR1 to the self-renewal and tumorigenicity of A2B5-defined glioma TPCs; as such, the abrogation of PAR1-dependent signaling pathways may prove a promising strategy for gliomas. PMID:26616854

  1. Method for producing evaporation inhibiting coating for protection of silicon--germanium and silicon--molybdenum alloys at high temperatures in vacuum

    DOEpatents

    Chao, P.J.

    1974-01-01

    A method is given for protecting Si--Ge and Si-- Mo alloys for use in thermocouples. The alloys are coated with silicon to inhibit the evaporation of the alloys at high tempenatures in a vacuum. Specific means and methods are provided. (5 fig) (Official Gazette)

  2. Neutralization of Inflammation by Inhibiting In vitro and In vivo Secretory Phospholipase A2 by Ethanol Extract of Boerhaavia diffusa L.

    PubMed Central

    Giresha, Aladahalli S.; Pramod, Siddanakoppalu N.; Sathisha, A. D.; Dharmappa, K. K.

    2017-01-01

    Background: Inflammation is a normal and necessary prerequisite to healing of the injured tissues. Inflammation contributes to all disease process including immunity, vascular pathology, trauma, sepsis, chemical, and metabolic injuries. The secretory phospholipase A2 (sPLA2) is a key enzyme in the production of pro-inflammatory mediators in chronic inflammatory disorders such as rheumatoid arthritis, coronary heart disease, diabetes, and asthma. The sPLA2 also contribute to neuroinflammatory disorders such as Parkinson's, Alzheimer's, and Crohn's disease. Aims: The present study aims to investigate the inhibition of human sPLA2 by a popular medicinal herb Boerhaavia diffusa Linn. as a function of anti-inflammatory activity. Materials and Methods: The aqueous and different organic solvents extracts of B. diffusa were prepared and evaluated for human synovial fluid, human pleural fluid, as well as Vipera russelli and Naja naja venom sPLA2 enzyme inhibition. Results: Among the extracts, the ethanol extract of B. diffusa (EEBD) showed the highest sPLA2 inhibition and IC50 values ranging from 17.8 to 27.5 μg. Further, antioxidant and lipid peroxidation activities of B. diffusa extract were checked using 2,2-diphenyl-1-picrylhydrazyl radical, thiobarbituric acid, and rat liver homogenate. The antioxidant activity of EEBD was more or less directly proportional to in vitro sPLA2 inhibition. Eventually, the extract was subjected to neutralize sPLA2-induced mouse paw edema and indirect hemolytic activity. The EEBD showed similar potency in both the cases. Conclusions: The findings suggest that the bioactive molecule/s from the EEBD is/are potentially responsible for the observed in vitro and in vivo sPLA2 inhibition and antioxidant activity. SUMMARY The present study aims to investigate the inhibition of human sPLA2 by a popular medicinal herb Boerhaavia diffusa Linn. as a function of anti inflammatory activity. Abbreviation Used: EEBD: Ethanolic extract of boerhaavia

  3. PDZ1 inhibitor peptide protects neurons against ischemia via inhibiting GluK2-PSD-95-module-mediated Fas signaling pathway.

    PubMed

    Yin, Xiao-Hui; Yan, Jing-Zhi; Yang, Guo; Chen, Li; Xu, Xiao-Feng; Hong, Xi-Ping; Wu, Shi-Liang; Hou, Xiao-Yu; Zhang, GuangYi

    2016-04-15

    Respecting the selective inhibition of peptides on protein-protein interactions, they might become potent methods in ischemic stroke therapy. In this study, we investigated the effect of PDZ1 inhibitor peptide on ischemic neuron apoptosis and the relative mechanism. Results showed that PDZ1 inhibitor peptide, which significantly disrupted GluK2-PSD-95 interaction, efficiently protected neuron from ischemia/reperfusion-induced apoptosis. Further, PDZ1 inhibited FasL expression, DISC assembly and activation of Caspase 8, Bid, Caspase 9 and Caspase 3 after global brain ischemia. Based on our previous report that GluK2-PSD-95 pathway increased FasL expression after global brain ischemia, the neuron protection effect of PDZ1 inhibitor peptide was considered to be achieved by disrupting GluK2-PSD-95 interaction and subsequently inhibiting FasL expression and Fas apoptosis pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. BENZYL ALCOHOL PROTECTS AGAINST ACETAMINOPHEN HEPATOTOXICITY BY INHIBITING CYTOCHROME P450 ENZYMES BUT CAUSES MITOCHONDRIAL DYSFUNCTION AND CELL DEATH AT HIGHER DOSES

    PubMed Central

    Du, Kuo; McGill, Mitchell R.; Xie, Yuchao; Jaeschke, Hartmut

    2015-01-01

    Acetaminophen (APAP) hepatotoxicity is a serious public health problem in western countries. Current treatment options for APAP poisoning are limited and novel therapeutic intervention strategies are needed. A recent publication suggested that benzyl alcohol (BA) protects against APAP hepatotoxicity and could serve as a promising antidote for APAP poisoning. To assess the protective mechanisms of BA, C56Bl/6J mice were treated with 400mg/kg APAP and/or 270mg/kg BA. APAP alone caused extensive liver injury at 6h and 24h post-APAP. This injury was attenuated by BA co-treatment. Assessment of protein adduct formation demonstrated that BA inhibits APAP metabolic activation. In support of this, in vitro experiments also showed that BA dose-dependently inhibits cytochrome P450 activities. Correlating with the hepatoprotection of BA, APAP-induced oxidant stress and mitochondrial dysfunction were reduced. Similar results were obtained in primary mouse hepatocytes. Interestingly, BA alone caused mitochondrial membrane potential loss and cell toxicity at high doses, and its protective effect could not be reproduced in primary human hepatocytes (PHH). We conclude that BA protects against APAP hepatotoxicity mainly by inhibiting cytochrome P450 enzymes in mice. Considering its toxic effect and the loss of protection in PHH, BA is not a clinically useful treatment option for APAP overdose patient. PMID:26522885

  5. Benzyl alcohol protects against acetaminophen hepatotoxicity by inhibiting cytochrome P450 enzymes but causes mitochondrial dysfunction and cell death at higher doses.

    PubMed

    Du, Kuo; McGill, Mitchell R; Xie, Yuchao; Jaeschke, Hartmut

    2015-12-01

    Acetaminophen (APAP) hepatotoxicity is a serious public health problem in western countries. Current treatment options for APAP poisoning are limited and novel therapeutic intervention strategies are needed. A recent publication suggested that benzyl alcohol (BA) protects against APAP hepatotoxicity and could serve as a promising antidote for APAP poisoning. To assess the protective mechanisms of BA, C56Bl/6J mice were treated with 400 mg/kg APAP and/or 270 mg/kg BA. APAP alone caused extensive liver injury at 6 h and 24 h post-APAP. This injury was attenuated by BA co-treatment. Assessment of protein adduct formation demonstrated that BA inhibits APAP metabolic activation. In support of this, in vitro experiments also showed that BA dose-dependently inhibits cytochrome P450 activities. Correlating with the hepatoprotection of BA, APAP-induced oxidant stress and mitochondrial dysfunction were reduced. Similar results were obtained in primary mouse hepatocytes. Interestingly, BA alone caused mitochondrial membrane potential loss and cell toxicity at high doses, and its protective effect could not be reproduced in primary human hepatocytes (PHH). We conclude that BA protects against APAP hepatotoxicity mainly by inhibiting cytochrome P450 enzymes in mice. Considering its toxic effect and the loss of protection in PHH, BA is not a clinically useful treatment option for APAP overdose patient. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Curcumin protects neuronal cells against status-epilepticus-induced hippocampal damage through induction of autophagy and inhibition of necroptosis.

    PubMed

    Wang, Jin; Liu, Yuan; Li, Xiao-Hui; Zeng, Xiang-Chang; Li, Jian; Zhou, Jun; Xiao, Bo; Hu, Kai

    2017-05-01

    Status epilepticus, the most severe form of epilepsy, is characterized by progressive functional and structural damage in the hippocampus, ultimately leading to the development and clinical appearance of spontaneous, recurrent seizures. Although the pathogenesis underlying epileptogenesis processes remains unclear, a substantial body of evidence has shown that status epilepticus acts as an important initial factor in triggering epileptogenesis. Notably, besides classical cell death mechanisms such as apoptosis and necrosis, 2 novel regulators of cell fate known as necroptosis and autophagy, are demonstrated to be involved in neuronal damage in various neurodegenerative and neuropsychiatric disorders. However, whether necroptosis and autophagy play a role in post-status-epilepticus rat hippocampus and other epilepsy mechanisms deserves further research effort. In addition, research is needed to determine whether compounds from traditional Chinese herbs possess antiepileptic effects through the modulation of necroptosis and autophagy. In this study, we found that curcumin, a polyphenolic phytochemical extracted from the Curcuma longa plant, protects neuronal cells against status-epilepticus-induced hippocampal neuronal damage in the lithium-pilocarpine-induced status epilepticus rat model through induction of autophagy and inhibition of necroptosis.

  7. Cerebrovascular Protective Effect of Boldine Against Neural Apoptosis via Inhibition of Mitochondrial Bax Translocation and Cytochrome C Release

    PubMed Central

    Qiu, Xiaozhong; Shi, Ling; Zhuang, Hanting; Zhang, Hongtao; Wang, Juan; Wang, Lijun; Sun, Peng; Yu, Lili; Liu, Longxi

    2017-01-01

    Background In the present study, we explored the protective effect and mechanism of action of boldine (BOL) against neural apoptosis, which is a mediator of TBI. Material/Methods The effect of BOL on mitochondrial and cytosol proteins of extracted from cerebral cortical tissue of mice was evaluated. The grip test was used to assess the neurological deficit and brain water content of the subjects after administration of BOL to assess its effect on SOD, GSH, and MDA activity in brain ischemic tissues. To further confirm the effect of the BOL, the histopathological analysis and morphology of neurons were studied by Nissl staining. The effect of BOL against TBI-induced neural apoptosis by immuno-histochemistry and Western blotting assay were also studied. Result BOL showed significant improvement against TBI in a dose-dependent manner. In the BOL-treated group, the apoptotic index was significantly reduced, but the level of caspase-3 was greatly diminished. Additionally, the level of the Bax in mitochondria (mit) and cytosol was elevated in the TBI-treated group as compared to the sham group. Further BOL at the test dose causes significant reduction in the level of mitochondrial MDA together with increase in SOD activity as compared to the TBI alone group. Conclusions BOL showed a cerebroprotective effect against TBI by attenuating the oxidative stress and the mitochondrial apoptotic pathway. It also inhibited mitochondrial Bax translocation and cytochrome c release. PMID:28841638

  8. The major reverse-transcriptase-incompetent splice variant of the human telomerase protein inhibits telomerase activity but protects from apoptosis

    PubMed Central

    Listerman, Imke; Sun, Jie; Gazzaniga, Francesca S.; Lukas, Jason L.; Blackburn, Elizabeth H.

    2013-01-01

    hTERT (TERT), the catalytic protein subunit of telomerase, is subjected to numerous alternative splicing events, but the regulation and function of these splice variants is obscure. Full-length hTERT includes conserved domains that encode reverse transcriptase activity, RNA binding and other functions. The major splice variant termed α+β− or β-deletion is highly expressed in stem and cancer cells, where it codes for a truncated protein lacking most of the reverse transcriptase domain but retaining the known RNA binding motifs. In a breast cancer cell panel, we found that β-deletion was the hTERT transcript that was most highly expressed. Splicing of this transcript was controlled by the splice regulators SRSF11, HNRNPH2 and HNRNPL and the β-deletion transcript variant was associated with polyribosomes in cells. When ectopically overexpressed, β-deletion protein competed for binding to hTR (TERC) RNA, thereby inhibiting endogenous telomerase activity. Overexpressed β-deletion protein localized to the nucleus and mitochondria and it protected breast cancer cells from cisplatin-induced apoptosis. Our results reveal that a major hTERT splice variant can confer a growth advantage to cancer cells independent of telomere maintenance, suggesting hTERT makes multiple contributions to cancer pathophysiology. PMID:23610451

  9. Angptl4 protects against severe proinflammatory effects of saturated fat by inhibiting fatty acid uptake into mesenteric lymph node macrophages.

    PubMed

    Lichtenstein, Laeticia; Mattijssen, Frits; de Wit, Nicole J; Georgiadi, Anastasia; Hooiveld, Guido J; van der Meer, Roelof; He, Yin; Qi, Ling; Köster, Anja; Tamsma, Jouke T; Tan, Nguan Soon; Müller, Michael; Kersten, Sander

    2010-12-01

    Dietary saturated fat is linked to numerous chronic diseases, including cardiovascular disease. Here we study the role of the lipoprotein lipase inhibitor Angptl4 in the response to dietary saturated fat. Strikingly, in mice lacking Angptl4, saturated fat induces a severe and lethal phenotype characterized by fibrinopurulent peritonitis, ascites, intestinal fibrosis, and cachexia. These abnormalities are preceded by a massive acute phase response induced by saturated but not unsaturated fat or medium-chain fat, originating in mesenteric lymph nodes (MLNs). MLNs undergo dramatic expansion and contain numerous lipid-laden macrophages. In peritoneal macrophages incubated with chyle, Angptl4 dramatically reduced foam cell formation, inflammatory gene expression, and chyle-induced activation of ER stress. Induction of macrophage Angptl4 by fatty acids is part of a mechanism that serves to reduce postprandial lipid uptake from chyle into MLN-resident macrophages by inhibiting triglyceride hydrolysis, thereby preventing macrophage activation and foam cell formation and protecting against progressive, uncontrolled saturated fat-induced inflammation.

  10. Benidipine protects kidney through inhibiting ROCK1 activity and reducing the epithelium-mesenchymal transdifferentiation in type 1 diabetic rats.

    PubMed

    Wu, Ganlin; Xu, Meirong; Xu, Kui; Hu, Yilan

    2013-01-01

    We investigated the protective effect of benidipine, by testing the changes of the activity of Rho kinase and transdifferentiation of renal tubular epithelium cells in vivo. Wistar rats were randomly divided into two groups: normal (N) and diabetes. STZ were used to make the rats type 1 diabetic and were randomly assigned as diabetes without treatment (D), diabetes treated with benidipine (B), and diabetes treated with fasudil (F) and treated for 3 months. Immunohistochemistry and western blotting were for protein expressions of ROCK1, α-SMA, and E-cadherin and real-time PCR for the mRNA quantification of ROCK1. Compared with N group, D group had significant proliferation of glomerular mesangial matrix, increased cell number, thickened basement membrane, widely infiltrated by inflammatory cells and fibrosis in the renal interstitial, and dilated tubular. Those presentations in F and B groups were milder. Compared with N group, D group showed elevated MYPT1 phosphorylation, increased expression of ROCK1, α-SMA protein, and ROCK1 mRNA and decreased expression of E-cadherin protein. B group showed attenuated MYPT1 phosphorylation, decreased ROCK1, α-SMA protein, and ROCK1 mRNA expression and increased expression of E-cadherin protein. In conclusion, benidipine reduces the epithelium-mesenchymal transdifferentiation and renal interstitial fibrosis in diabetic kidney by inhibiting ROCK1 activity.

  11. Inhibition of mTOR enhances radiosensitivity of lung cancer cells and protects normal lung cells against radiation.

    PubMed

    Zheng, Hang; Wang, Miao; Wu, Jing; Wang, Zhi-Ming; Nan, Hai-Jun; Sun, He

    2016-06-01

    Radiotherapy has been used for a long time as a standard therapy for cancer; however, there have been no recent research breakthroughs. Radioresistance and various side-effects lead to the unexpected outcomes of radiation therapy. Specific and accurate targeting as well as reduction of radioresistance have been major challenges for irradiation therapy. Recent studies have shown that rapamycin shows promise for inhibiting tumorigenesis by suppressing mammalian target of rapamycin (mTOR). We found that the combination of rapamycin with irradiation significantly diminished cell viability and colony formation, and increased cell apoptosis, as compared with irradiation alone in lung cancer cell line A549, suggesting that rapamycin can enhance the effectiveness of radiation therapy by sensitizing cancer cells to irradiation. Importantly, we observed that the adverse effects of irradiation on a healthy lung cell line (WI-38) were also offset. No enhanced protein expression of mTOR signaling was observed in WI-38 cells, which is normally elevated in lung cancer cells. Moreover, DNA damage was significantly less with the combination therapy than with irradiation therapy alone. Our data suggest that the incorporation of rapamycin during radiation therapy could be a potent way to improve the sensitivity and effectiveness of radiation therapy as well as to protect normal cells from being damaged by irradiation.

  12. Targeting Inhibition of SmpB by Peptide Aptamer Attenuates the Virulence to Protect Zebrafish against Aeromonas veronii Infection.

    PubMed

    Liu, Peng; Huang, Dongyi; Hu, Xinwen; Tang, Yanqiong; Ma, Xiang; Yan, Rihui; Han, Qian; Guo, Jianchun; Zhang, Yueling; Sun, Qun; Liu, Zhu

    2017-01-01

    Aeromonas veronii is an important pathogen of aquatic animals, wherein Small protein B (SmpB) is required for pathogenesis by functioning as both a component in stalled-ribosome rescue and a transcription factor in upregulation of virulence gene bvgS expression. Here a specific peptide aptamer PA-1 was selected from peptide aptamer library by bacterial two-hybrid system employing pBT-SmpB as bait. The binding affinity between SmpB and PA-1 was evaluated using enzyme-linked immunosorbent assay. The key amino acids of SmpB that interact with PA-1 were identified. After PA-1 was introduced into A. veronii, the engineered strain designated as A. veronii (pN-PA-1) was more sensitive and grew slower under salt stress in comparison with wild type, as the disruption of SmpB by PA-1 resulted in significant transcription reductions of virulence-related genes. Consistent with these observations, A. veronii (pN-PA-1) was severely attenuated in model organism zebrafish, and vaccination of zebrafish with A. veronii (pN-PA-1) induced a strong antibody response. The vaccinated zebrafish were well protected against subsequent lethal challenges with virulent parental strain. Collectively, we propose that targeting inhibition of SmpB by peptide aptamer PA-1 possesses the desired qualities for a live attenuated vaccine against pathogenic A. veronii.

  13. Protective Role of PGC-1α in Diabetic Nephropathy Is Associated with the Inhibition of ROS through Mitochondrial Dynamic Remodeling

    PubMed Central

    Huang, Yan; Wu, Mian; Zhang, Lei; Yu, Haoyong; Zhang, Mingliang; Bao, Yuqian; He, John Cijiang; Chen, Haibing; Jia, Weiping

    2015-01-01

    The overproduction of mitochondrial reactive oxygen species (ROS) plays a key role in the pathogenesis of diabetic nephropathy (DN). However, the underlying molecular mechanism remains unclear. Our aim was to investigate the role of PGC-1α in the pathogenesis of DN. Rat glomerular mesangial cells (RMCs) were incubated in normal or high glucose medium with or without the PGC-1α-overexpressing plasmid (pcDNA3-PGC-1α) for 48 h. In the diabetic rats, decreased PGC-1α expression was associated with increased mitochondrial ROS generation in the renal cortex, increased proteinuria, glomerular hypertrophy, and higher glomerular 8-OHdG (a biomarker for oxidative stress). In vitro, hyperglycemia induced the downregulation of PGC-1α, which led to increased DRP1 expression, increased mitochondrial fragmentation and damaged network structure. This was associated with an increase in ROS generation and mesangial cell hypertrophy. These pathological changes were reversed in vitro by the transfection of pcDNA3-PGC-1α. These data suggest that PGC-1α may protect DN via the inhibition of DRP1-mediated mitochondrial dynamic remodeling and ROS production. These findings may assist the development of novel therapeutic strategies for patients