目的:探讨温针灸对类风湿性关节炎(RA)大鼠关节滑膜组织沉默信息调节因子2相关酶1(SIRT 1)表达的影响,以及对核转录因子-κB(NF-κB)的调节作用,分析温针灸改善RA的机制。方法:SD大鼠50只(雌雄各半),随机分为正常组、模型组、抑制剂组...目的:探讨温针灸对类风湿性关节炎(RA)大鼠关节滑膜组织沉默信息调节因子2相关酶1(SIRT 1)表达的影响,以及对核转录因子-κB(NF-κB)的调节作用,分析温针灸改善RA的机制。方法:SD大鼠50只(雌雄各半),随机分为正常组、模型组、抑制剂组、温针灸组、抑制剂+温针灸组,每组10只,采用皮内注射牛Ⅱ型胶原接种诱发制备大鼠RA模型,共21d。温针灸组于造模第1天取"足三里""肾俞"和"悬钟"温针灸治疗,刺激量以大鼠耐受为度,1次/d,共21d。抑制剂组于造模第1、7、14、21天腹腔内注射SIRT 1抑制剂尼克酰胺溶液。抑制剂+温针灸组于造模同时给予SIRT 1抑制剂,温针灸治疗同温针灸组。所有大鼠采用排水法测肿胀关节部体积,放射免疫法检测血清炎性因子IL-1β、IL-6和IL-8含量,免疫印迹法检测膝关节滑膜组织SIRT 1和NF-κB p 65蛋白的表达。结果:与正常组相比,模型组大鼠关节肿胀明显,血清中炎性因子IL-1β、IL-6和IL-8含量较高,膝关节滑膜组织SIRT 1蛋白表达减少,NF-κB p 65蛋白表达增加(P<0.01)。与模型组相比,温针灸组大鼠关节肿胀改善明显,炎性因子IL-1β、IL-6和IL-8含量减少,SIRT 1蛋白表达升高,NF-κB p 65蛋白表达降低(P<0.05)。与温针灸组相比,抑制剂+温针灸组大鼠关节肿胀改善程度较差(P>0.05);血清中炎性因子IL-1β、IL-6和IL-8含量较高,膝关节滑膜组织SIRT 1蛋白表达减少,NF-κB p 65蛋白表达增加(P<0.05)。结论:温针灸能有效降低RA大鼠血清炎性因子,调节关节滑膜组织SIRT 1和NF-κB p 65表达,这可能是温针灸改善RA关节炎性损伤的机制之一。展开更多
目的研究大黄酸对糖尿病大鼠肾组织沉默接合型信息调节因子2同源蛋白1(SIRT1)表达的影响,探讨大黄酸对糖尿病大鼠肾脏损伤的保护作用及可能机制。方法采用高糖高脂饮食联合链脲佐菌素(35 mg/kg体质量)诱导2型糖尿病大鼠模型,分为正常组...目的研究大黄酸对糖尿病大鼠肾组织沉默接合型信息调节因子2同源蛋白1(SIRT1)表达的影响,探讨大黄酸对糖尿病大鼠肾脏损伤的保护作用及可能机制。方法采用高糖高脂饮食联合链脲佐菌素(35 mg/kg体质量)诱导2型糖尿病大鼠模型,分为正常组,糖尿病组,低、中、高剂量(50、100、150 mg/kg)大黄酸治疗组及10 mg/kg吡格列酮对照组。灌胃给药,每日1次。16周末检测大鼠空腹血糖(FPG)、空腹胰岛素(FINS)、甘油三酯(TG)、总胆固醇(TC)、血肌酐(Scr)、24 h尿蛋白(24 h U-PRO);计算肾质量指数(KM/BM)、胰岛素抵抗指数;PAS染色光镜观察肾组织病理形态学的改变;病理图像分析系统分析平均肾小球面积(MGA)及平均肾小球体积(MGV);实时荧光定量PCR检测肾组织SIRT1 mRNA表达;Western blot法检测肾组织SIRT1蛋白表达。结果糖尿病大鼠肾组织SIRT1表达降低。与糖尿病组比较,各治疗组大鼠FPG、FINS、HOMA-IR、TG、TC、Scr、24 h U-PRO、肾质量指数、MGA、MGV显著降低,肾组织病理形态学明显改善;SIRT1 mRNA及蛋白表达显著增加;大黄酸高剂量组各指标改善较显著。相关性分析显示,SIRT1蛋白表达与24 h U-PRO、MGV呈显著负相关。结论糖尿病大鼠肾组织SIRT1表达降低,大黄酸可通过改善胰岛素抵抗和血脂紊乱,增加SIRT1的表达,改善糖尿病大鼠肾脏损害。展开更多
BACKGROUND Sirtuin 1(SIRT1)is a nicotinamide adenine dinucleotide(NAD+)-dependent protein deacetylase that is involved in various diseases,including cancers,metabolic diseases,and inflammation-associated diseases.Howe...BACKGROUND Sirtuin 1(SIRT1)is a nicotinamide adenine dinucleotide(NAD+)-dependent protein deacetylase that is involved in various diseases,including cancers,metabolic diseases,and inflammation-associated diseases.However,the role of SIRT1 in ulcerative colitis(UC)is still confusing.AIM To investigate the role of SIRT1 in intestinal epithelial cells(IECs)in UC and further explore the underlying mechanisms.METHODS We developed a coculture model using macrophages and Caco-2 cells.After treatment with the SIRT1 activator SRT1720 or inhibitor nicotinamide(NAM),the expression of occludin and zona occludens 1(ZO-1)was assessed by Western blot analysis.Annexin V-APC/7-AAD assays were performed to evaluate Caco-2 apoptosis.Dextran sodium sulfate(DSS)-induced colitis mice were exposed to SRT1720 or NAM for 7 d.Transferase-mediated dUTP nick-end labeling(TUNEL)assays were conducted to assess apoptosis in colon tissues.The expression levels of glucose-regulated protein 78(GRP78),CCAAT/enhancerbinding protein homologous protein(CHOP),caspase-12,caspase-9,and caspase-3 in Caco-2 cells and the colon tissues of treated mice were examined by quantitative real-time PCR and Western blot.RESULTS SRT1720 treatment increased the protein levels of occludin and ZO-1 and inhibited Caco-2 apoptosis,whereas NAM administration caused the opposite effects.DSS-induced colitis mice treated with SRT1720 had a lower disease activity index(P<0.01),histological score(P<0.001),inflammatory cytokine levels(P<0.01),and apoptotic cell rate(P<0.01),while exposure to NAM caused the opposite effects.Moreover,SIRT1 activation reduced the expression levels of GRP78,CHOP,cleaved caspase-12,cleaved caspase-9,and cleaved caspase-3 in Caco-2 cells and the colon tissues of treated mice.CONCLUSION SIRT1 activation reduces apoptosis of IECs via the suppression of endoplasmic reticulum stress-mediated apoptosis-associated molecules CHOP and caspase-12.SIRT1 activation may be a potential therapeutic strategy for UC.展开更多
Ischemia-reperfusion injury(IRI)remains an unresolved and complicated situation in clinical practice,especially in the case of organ transplantation.Several factors contribute to its complexity;the depletion of energy...Ischemia-reperfusion injury(IRI)remains an unresolved and complicated situation in clinical practice,especially in the case of organ transplantation.Several factors contribute to its complexity;the depletion of energy during ischemia and the induction of oxidative stress during reperfusion initiate a cascade of pathways that lead to cell death and finally to severe organ injury.Recently,the sirtuin family of nicotinamide adenine dinucleotide-dependent deacetylases has gained increasing attention from researchers,due to their involvement in the modulation of a wide variety of cellular functions.There are seven mammalian sirtuins and,among them,the nuclear/cytoplasmic sirtuin 1(SIRT1)and the mitochondrial sirtuin 3(SIRT3)are ubiquitously expressed in many tissue types.Sirtuins are known to play major roles in protecting against cellular stress and in controlling metabolic pathways,which are key processes during IRI.In this review,we mainly focus on SIRT1 and SIRT3 and examine their role in modulating pathways against energy depletion during ischemia and their involvement in oxidative stress,apoptosis,microcirculatory stress and inflammation during reperfusion.We present evidence of the beneficial effects of sirtuins against IRI and emphasize the importance of developing new strategies by enhancing their action.展开更多
BACKGROUND It is well known that nonalcoholic fatty liver disease(NAFLD)is associated with insulin resistance(IR).LB100,a serine/threonine protein phosphatase 2A(PP2A)inhibitor,is closely related to IR.However,there i...BACKGROUND It is well known that nonalcoholic fatty liver disease(NAFLD)is associated with insulin resistance(IR).LB100,a serine/threonine protein phosphatase 2A(PP2A)inhibitor,is closely related to IR.However,there is little data regarding its direct influence on NAFLD.AIM To elucidate the effect and underlying mechanism of LB100 in NAFLD.METHODS After 10 wk of high fat diet(HFD)feeding,male C57BL/6 mice were injected intraperitoneally with vehicle or LB100 for an additional 6 wk(three times a week).The L02 cell line was treated with LB100 and free fatty acids(FFAs)for 24 h.Hematoxylin and eosin and oil red O staining were performed for histological examination.Western blot analysis was used to detect the protein expression of Sirtuin 1(Sirt1),total and phosphorylated AMP-activated protein kinaseα(AMPKα),and the proteins involved in lipogenesis and fatty acid oxidation.The mRNA levels were determined by qPCR.Pharmacological inhibition of AMPK was performed to further examine the exact mechanism of LB100 in NAFLD.RESULTS LB100 significantly ameliorated HFD-induced obesity,hepatic lipid accumulation and hepatic injury in mice.In addition,LB100 significantly downregulated the protein levels of acetyl-CoA carboxylase,sterol regulatory element-binding protein 1 and its lipogenesis target genes,including stearoyl-CoA desaturase-1 and fatty acid synthase,and upregulated the levels of proteins involved in fatty acidβ-oxidation,such as peroxisome proliferator-activated receptorα(PPARα),peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α),carnitine palmitoyltransferase 1α,acyl-CoA oxidase 1 and uncoupling protein 2,as well as the upstream mediators Sirt1 and AMPKαin the livers of HFD-fed mice.In vitro,LB100 alleviated FFA-induced lipid accumulation in L02 cells through the AMPK/Sirt1 signaling pathway.Further studies showed that the curative effect of LB100 on lipid accumulation was abolished by inhibiting AMPKαin L02 cells.CONCLUSION PP2A inhibition by LB100 significantly ameliorates hepatic 展开更多
Obesity, especially at mid-life, is a major risk factor for atherosclerosis, insulin resistance and the metabolic syndrome, which in turn contribute to coronary artery disease (CAD), Type 2 diabetes and Alzheimer’s d...Obesity, especially at mid-life, is a major risk factor for atherosclerosis, insulin resistance and the metabolic syndrome, which in turn contribute to coronary artery disease (CAD), Type 2 diabetes and Alzheimer’s disease (AD). The rise in overweight and obesity in all societies is prompting intense research into the causes and effects of the condition. Obesity disrupts many body systems including glucose and lipid metabolism, circadian rhythms and liver function. It also causes or increases inflammation and oxidative stress. Within cells, the endoplasmic reticulum (ER) appears to be particularly susceptible to such metabolic disruption. Sirtuin 1?(Sirt1) and leptin have received attention recently as they are central regulatory factors for the body’s metabolic pathways which interact at particular levels, for example lipid and Abeta metabolism. This mini-review discusses recent findings concerning obesity, lipid metabolism and the role of Sirtuin 1 and how all influence the ER. A greater understanding of obesity and its effects on metabolic control systems of the body are required, to develop pharmacological, dietary and lifestyle changes that will reduce the incidence of CAD, Type 2 diabetes and AD.展开更多
文摘目的:探讨温针灸对类风湿性关节炎(RA)大鼠关节滑膜组织沉默信息调节因子2相关酶1(SIRT 1)表达的影响,以及对核转录因子-κB(NF-κB)的调节作用,分析温针灸改善RA的机制。方法:SD大鼠50只(雌雄各半),随机分为正常组、模型组、抑制剂组、温针灸组、抑制剂+温针灸组,每组10只,采用皮内注射牛Ⅱ型胶原接种诱发制备大鼠RA模型,共21d。温针灸组于造模第1天取"足三里""肾俞"和"悬钟"温针灸治疗,刺激量以大鼠耐受为度,1次/d,共21d。抑制剂组于造模第1、7、14、21天腹腔内注射SIRT 1抑制剂尼克酰胺溶液。抑制剂+温针灸组于造模同时给予SIRT 1抑制剂,温针灸治疗同温针灸组。所有大鼠采用排水法测肿胀关节部体积,放射免疫法检测血清炎性因子IL-1β、IL-6和IL-8含量,免疫印迹法检测膝关节滑膜组织SIRT 1和NF-κB p 65蛋白的表达。结果:与正常组相比,模型组大鼠关节肿胀明显,血清中炎性因子IL-1β、IL-6和IL-8含量较高,膝关节滑膜组织SIRT 1蛋白表达减少,NF-κB p 65蛋白表达增加(P<0.01)。与模型组相比,温针灸组大鼠关节肿胀改善明显,炎性因子IL-1β、IL-6和IL-8含量减少,SIRT 1蛋白表达升高,NF-κB p 65蛋白表达降低(P<0.05)。与温针灸组相比,抑制剂+温针灸组大鼠关节肿胀改善程度较差(P>0.05);血清中炎性因子IL-1β、IL-6和IL-8含量较高,膝关节滑膜组织SIRT 1蛋白表达减少,NF-κB p 65蛋白表达增加(P<0.05)。结论:温针灸能有效降低RA大鼠血清炎性因子,调节关节滑膜组织SIRT 1和NF-κB p 65表达,这可能是温针灸改善RA关节炎性损伤的机制之一。
文摘目的研究大黄酸对糖尿病大鼠肾组织沉默接合型信息调节因子2同源蛋白1(SIRT1)表达的影响,探讨大黄酸对糖尿病大鼠肾脏损伤的保护作用及可能机制。方法采用高糖高脂饮食联合链脲佐菌素(35 mg/kg体质量)诱导2型糖尿病大鼠模型,分为正常组,糖尿病组,低、中、高剂量(50、100、150 mg/kg)大黄酸治疗组及10 mg/kg吡格列酮对照组。灌胃给药,每日1次。16周末检测大鼠空腹血糖(FPG)、空腹胰岛素(FINS)、甘油三酯(TG)、总胆固醇(TC)、血肌酐(Scr)、24 h尿蛋白(24 h U-PRO);计算肾质量指数(KM/BM)、胰岛素抵抗指数;PAS染色光镜观察肾组织病理形态学的改变;病理图像分析系统分析平均肾小球面积(MGA)及平均肾小球体积(MGV);实时荧光定量PCR检测肾组织SIRT1 mRNA表达;Western blot法检测肾组织SIRT1蛋白表达。结果糖尿病大鼠肾组织SIRT1表达降低。与糖尿病组比较,各治疗组大鼠FPG、FINS、HOMA-IR、TG、TC、Scr、24 h U-PRO、肾质量指数、MGA、MGV显著降低,肾组织病理形态学明显改善;SIRT1 mRNA及蛋白表达显著增加;大黄酸高剂量组各指标改善较显著。相关性分析显示,SIRT1蛋白表达与24 h U-PRO、MGV呈显著负相关。结论糖尿病大鼠肾组织SIRT1表达降低,大黄酸可通过改善胰岛素抵抗和血脂紊乱,增加SIRT1的表达,改善糖尿病大鼠肾脏损害。
基金Supported by the National Nature Science Foundation of China,No.81600414the Natural Science Foundation of Zhejiang Province,No.LQ16H030001Zhejiang TCM Science and Technology Project,No.2016ZA123 and No.2018ZA013
文摘BACKGROUND Sirtuin 1(SIRT1)is a nicotinamide adenine dinucleotide(NAD+)-dependent protein deacetylase that is involved in various diseases,including cancers,metabolic diseases,and inflammation-associated diseases.However,the role of SIRT1 in ulcerative colitis(UC)is still confusing.AIM To investigate the role of SIRT1 in intestinal epithelial cells(IECs)in UC and further explore the underlying mechanisms.METHODS We developed a coculture model using macrophages and Caco-2 cells.After treatment with the SIRT1 activator SRT1720 or inhibitor nicotinamide(NAM),the expression of occludin and zona occludens 1(ZO-1)was assessed by Western blot analysis.Annexin V-APC/7-AAD assays were performed to evaluate Caco-2 apoptosis.Dextran sodium sulfate(DSS)-induced colitis mice were exposed to SRT1720 or NAM for 7 d.Transferase-mediated dUTP nick-end labeling(TUNEL)assays were conducted to assess apoptosis in colon tissues.The expression levels of glucose-regulated protein 78(GRP78),CCAAT/enhancerbinding protein homologous protein(CHOP),caspase-12,caspase-9,and caspase-3 in Caco-2 cells and the colon tissues of treated mice were examined by quantitative real-time PCR and Western blot.RESULTS SRT1720 treatment increased the protein levels of occludin and ZO-1 and inhibited Caco-2 apoptosis,whereas NAM administration caused the opposite effects.DSS-induced colitis mice treated with SRT1720 had a lower disease activity index(P<0.01),histological score(P<0.001),inflammatory cytokine levels(P<0.01),and apoptotic cell rate(P<0.01),while exposure to NAM caused the opposite effects.Moreover,SIRT1 activation reduced the expression levels of GRP78,CHOP,cleaved caspase-12,cleaved caspase-9,and cleaved caspase-3 in Caco-2 cells and the colon tissues of treated mice.CONCLUSION SIRT1 activation reduces apoptosis of IECs via the suppression of endoplasmic reticulum stress-mediated apoptosis-associated molecules CHOP and caspase-12.SIRT1 activation may be a potential therapeutic strategy for UC.
基金Supported by AGAUR,No.2012FI_B00382,Generalitat de Catalunya,Barcelona,Spain,to Pantazi ECSIC for the development program to Bejaoui M,No.I-COOP0005The Fondo de Investigaciones Sanitarias,No.FIS PI12/00519
文摘Ischemia-reperfusion injury(IRI)remains an unresolved and complicated situation in clinical practice,especially in the case of organ transplantation.Several factors contribute to its complexity;the depletion of energy during ischemia and the induction of oxidative stress during reperfusion initiate a cascade of pathways that lead to cell death and finally to severe organ injury.Recently,the sirtuin family of nicotinamide adenine dinucleotide-dependent deacetylases has gained increasing attention from researchers,due to their involvement in the modulation of a wide variety of cellular functions.There are seven mammalian sirtuins and,among them,the nuclear/cytoplasmic sirtuin 1(SIRT1)and the mitochondrial sirtuin 3(SIRT3)are ubiquitously expressed in many tissue types.Sirtuins are known to play major roles in protecting against cellular stress and in controlling metabolic pathways,which are key processes during IRI.In this review,we mainly focus on SIRT1 and SIRT3 and examine their role in modulating pathways against energy depletion during ischemia and their involvement in oxidative stress,apoptosis,microcirculatory stress and inflammation during reperfusion.We present evidence of the beneficial effects of sirtuins against IRI and emphasize the importance of developing new strategies by enhancing their action.
文摘BACKGROUND It is well known that nonalcoholic fatty liver disease(NAFLD)is associated with insulin resistance(IR).LB100,a serine/threonine protein phosphatase 2A(PP2A)inhibitor,is closely related to IR.However,there is little data regarding its direct influence on NAFLD.AIM To elucidate the effect and underlying mechanism of LB100 in NAFLD.METHODS After 10 wk of high fat diet(HFD)feeding,male C57BL/6 mice were injected intraperitoneally with vehicle or LB100 for an additional 6 wk(three times a week).The L02 cell line was treated with LB100 and free fatty acids(FFAs)for 24 h.Hematoxylin and eosin and oil red O staining were performed for histological examination.Western blot analysis was used to detect the protein expression of Sirtuin 1(Sirt1),total and phosphorylated AMP-activated protein kinaseα(AMPKα),and the proteins involved in lipogenesis and fatty acid oxidation.The mRNA levels were determined by qPCR.Pharmacological inhibition of AMPK was performed to further examine the exact mechanism of LB100 in NAFLD.RESULTS LB100 significantly ameliorated HFD-induced obesity,hepatic lipid accumulation and hepatic injury in mice.In addition,LB100 significantly downregulated the protein levels of acetyl-CoA carboxylase,sterol regulatory element-binding protein 1 and its lipogenesis target genes,including stearoyl-CoA desaturase-1 and fatty acid synthase,and upregulated the levels of proteins involved in fatty acidβ-oxidation,such as peroxisome proliferator-activated receptorα(PPARα),peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α),carnitine palmitoyltransferase 1α,acyl-CoA oxidase 1 and uncoupling protein 2,as well as the upstream mediators Sirt1 and AMPKαin the livers of HFD-fed mice.In vitro,LB100 alleviated FFA-induced lipid accumulation in L02 cells through the AMPK/Sirt1 signaling pathway.Further studies showed that the curative effect of LB100 on lipid accumulation was abolished by inhibiting AMPKαin L02 cells.CONCLUSION PP2A inhibition by LB100 significantly ameliorates hepatic
文摘Obesity, especially at mid-life, is a major risk factor for atherosclerosis, insulin resistance and the metabolic syndrome, which in turn contribute to coronary artery disease (CAD), Type 2 diabetes and Alzheimer’s disease (AD). The rise in overweight and obesity in all societies is prompting intense research into the causes and effects of the condition. Obesity disrupts many body systems including glucose and lipid metabolism, circadian rhythms and liver function. It also causes or increases inflammation and oxidative stress. Within cells, the endoplasmic reticulum (ER) appears to be particularly susceptible to such metabolic disruption. Sirtuin 1?(Sirt1) and leptin have received attention recently as they are central regulatory factors for the body’s metabolic pathways which interact at particular levels, for example lipid and Abeta metabolism. This mini-review discusses recent findings concerning obesity, lipid metabolism and the role of Sirtuin 1 and how all influence the ER. A greater understanding of obesity and its effects on metabolic control systems of the body are required, to develop pharmacological, dietary and lifestyle changes that will reduce the incidence of CAD, Type 2 diabetes and AD.
