目的探究沉默信息调节因子6(Sirtuin6,SIRT6)通过腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)/哺乳动物雷帕霉素靶蛋白(Mammaliantargetofrapamycin,mTOR)通路调节自噬对高糖诱导的H9c2心肌细胞损伤的影响。方法实验分两部...目的探究沉默信息调节因子6(Sirtuin6,SIRT6)通过腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)/哺乳动物雷帕霉素靶蛋白(Mammaliantargetofrapamycin,mTOR)通路调节自噬对高糖诱导的H9c2心肌细胞损伤的影响。方法实验分两部分进行,第一部分将H9c2心肌细胞分为NG组、HG组、HG+SIRT6组、NG+SIRT6组;第二部分分为HG组、HG+SIRT6组、HG+CompC组、HG+SIRT6+CompC组、HG+SIRT6+3MA组。给予NG组和NG+SIRT6组5.5 mM葡萄糖处理,HG组、HG+SIRT6组、HG+CompC组、HG+SIRT6+CompC组、HG+SIRT6+3MA组给予30 mM葡萄糖处理。对HG+SIRT6组、NG+SIRT6组、HG+SIRT6+CompC组、HG+SIRT6+3MA组进行SIRT6过表达转染。HG+SIRT6+CompC组和HG+SIRT6+3MA组分别用10μM CompC和2 mM 3MA处理12 h。qRT-PCR检测各组细胞SIRT6相对表达水平;免疫荧光染色检测各组细胞CTGF、CollagenⅠ和α-SMA的表达情况;透射电镜观察各组自噬小体数量;Western Blot检测各组细胞AMPK,p-AMPK,mTOR,p-mTOR,ULK1,p-ULK1,LC3,Beclin-1,p62蛋白表达。结果qRT-PCR结果显示,SIRT6过表达组SIRT6 mRNA相对表达量显著高于Control组(P<0.001),说明细胞转染成功。与NG组相比,HG组CTGF、CollagenⅠ和α-SMA蛋白的表达水平增加,平均荧光强度增强(P<0.001);与HG组相比,HG+SIRT6组CTGF、CollagenⅠ和α-SMA蛋白的表达水平明显降低,平均荧光强度减弱(P<0.05)。与NG组相比,HG组自噬小体数量减少;与HG组相比,HG+SIRT6组自噬小体数量增加;与HG+SIRT6组相比,HG+SIRT6+CompC组、HG+SIRT6+3MA组自噬小体数量减少。与HG组相比,HG+SIRT6组p-AMPK水平升高,p-mTOR和p-ULK1水平降低(P<0.01)。与HG组相比,HG+SIRT6组CTGF、CollagenⅠ和α-SMA蛋白的平均荧光强度显著降低(P<0.001);与HG+SIRT6组相比,HG+SIRT6+CompC组CTGF、CollagenⅠ和α-SMA蛋白的平均荧光强度增强(P<0.01);与HG+SIRT6组相比,HG+SIRT6+3MA组CTGF、CollagenⅠ和α-SMA蛋白的平均荧光强度增强(P<0.05)。与HG组相比,HG+SIRT6组LC3Ⅱ/Ⅰ、Beclin1蛋白表达水平增加,p62蛋白表达水平降低(P<0.001);与HG+SIRT6组相比,HG+SIRT6+3MA组、HG+SIRT6+CompC组LC3Ⅱ/Ⅰ、Beclin1蛋白表达水平降低,p62蛋白表达水平升高(P<0.05)。结论SIRT6通过激活AMPK/mTOR通路促进自噬,减轻高糖诱导的心肌细胞损伤,为预防和改善DCM提供理论依据。展开更多
Background:Statins are the cornerstone of low-density lipoprotein cholesterol(LDL-C)-lowering therapy;however,the therapeutic efficacy of statins in countering atherosclerotic cardiovascular disease(ASCVD)is compromis...Background:Statins are the cornerstone of low-density lipoprotein cholesterol(LDL-C)-lowering therapy;however,the therapeutic efficacy of statins in countering atherosclerotic cardiovascular disease(ASCVD)is compromised by the concurrent elevation of proprotein convertase subtilisin/kexin type 9(PCSK9),a pivotal molecule that increases LDL-C levels.Aerobic exercise lowers PCSK9 levels,but the underlying mechanism remains unclear.Therefore,we investigated how aerobic exercise can ameliorate statin-induced increases in PCSK9 levels.Methods:Three-week-old male American Institute of Cancer Research(ICR)mice were fed a high-fat-cholesterol diet(HFD)for 12 weeks and then administered atorvastatin alone or atorvastatin combined with aerobic exercise(Statin+Ex).Moreover,a total of 165 participants with stable coronary heart disease(CHD)enrolled at the Inpatient and Outpatient Departments of the Second Xiangya Hospital of Central South University,China,from January 2018 to July 2020 were randomized into the Statin group(male/female=51/33)and Statin+Ex group(male/female=52/29).Patients in the Statin+Ex group underwent treadmill exercise of 45-60 min/day for 7 days.Results:Aerobic exercise effectively alleviated statin-induced PCSK9 upregulation in human patients with CHD and hypercholesterolemic ICR mice(all p<0.05).Mechanistically,our findings revealed that aerobic exercise induced elevated epoxyeicosatrienoic acids(EETs)plasma levels while concurrently reducing the activity of soluble epoxide hydrolase(sEH)(all p<0.05),an enzyme responsible for EETs degradation.Further,EETs significantly suppressed PCSK9 expression,subsequently reducing the LDL-C levels(all p<0.05);this effect was mediated via the activation of the forkhead box O3a-silent mating type information regulation 2 homolog 6(FoxO3a-Sirt6)axis,with no impact on the sterol regulatory element binding protein 2 and 3-hydroxy-3-methylglutaryl-CoA reductase(SREBP2-HMGCR)pathway.Conclusion:Our study sheds light on the paradigm of"Exercise is Medicine",providing evidence to support the use of statins combined with exercise in reducing LDL-C levels,and unveils potential avenues for clinical applications of sEH inhibitors,presenting novel prospects for therapeutic interventions in ASCVD.展开更多
Patients with glioma have a very high mortality rate,thus improving the poor prognosis of glioma has been the goal in the therapeutic field.Searching for more effective drugs for gliomas from natural compounds is a pr...Patients with glioma have a very high mortality rate,thus improving the poor prognosis of glioma has been the goal in the therapeutic field.Searching for more effective drugs for gliomas from natural compounds is a promising strategy.In this study,both oleanonic acid and oleanolic acid inhibited proliferation of glioma cells and reduced expression of cyclin D1 and E1,but the former has a lower IC_(50)than the latter.Oleanonic acid reduced the expression of p-STAT3 but not p-STAT1 and 5,and also reducing the expression of STAT3 in the nucleus and its transcriptional activity in glioma cells.Furthermore,knockdown of STAT3 expression inhibited proliferation and migration of glioma cells.Next,the expressions of the upstream regulators such as SIRT6 and p-JAK2 but not SIRT1,p-ERK1/2,p300 were increased by oleanonic acid.The overexpression of SIRT6 not only reduced the expression of p-STAT3 and its transcriptional activity but also inhibited the proliferation and migration of glioma cells.In addition,the effects that oleanonic acid reduced the expression of p-STAT3 and its transcriptional activity and inhibited the proliferation and migration were attenuated by the knockdown of SIRT6.Furthermore,oleanonic acid effectively suppressed glioma growth and extended survival in nude mice bearing intracerebral U87 xenografts,but not in nude mice bearing intracerebral SIRT6-knockdown U87xenografts.In conclusion,oleanonic acid upregulates the expression of SIRT6 to inactivates STAT3 and then inhibits glioma growth.展开更多
基金supported by the National Natural Science Foundation of China(No.81871858 and No.82172550).
文摘Background:Statins are the cornerstone of low-density lipoprotein cholesterol(LDL-C)-lowering therapy;however,the therapeutic efficacy of statins in countering atherosclerotic cardiovascular disease(ASCVD)is compromised by the concurrent elevation of proprotein convertase subtilisin/kexin type 9(PCSK9),a pivotal molecule that increases LDL-C levels.Aerobic exercise lowers PCSK9 levels,but the underlying mechanism remains unclear.Therefore,we investigated how aerobic exercise can ameliorate statin-induced increases in PCSK9 levels.Methods:Three-week-old male American Institute of Cancer Research(ICR)mice were fed a high-fat-cholesterol diet(HFD)for 12 weeks and then administered atorvastatin alone or atorvastatin combined with aerobic exercise(Statin+Ex).Moreover,a total of 165 participants with stable coronary heart disease(CHD)enrolled at the Inpatient and Outpatient Departments of the Second Xiangya Hospital of Central South University,China,from January 2018 to July 2020 were randomized into the Statin group(male/female=51/33)and Statin+Ex group(male/female=52/29).Patients in the Statin+Ex group underwent treadmill exercise of 45-60 min/day for 7 days.Results:Aerobic exercise effectively alleviated statin-induced PCSK9 upregulation in human patients with CHD and hypercholesterolemic ICR mice(all p<0.05).Mechanistically,our findings revealed that aerobic exercise induced elevated epoxyeicosatrienoic acids(EETs)plasma levels while concurrently reducing the activity of soluble epoxide hydrolase(sEH)(all p<0.05),an enzyme responsible for EETs degradation.Further,EETs significantly suppressed PCSK9 expression,subsequently reducing the LDL-C levels(all p<0.05);this effect was mediated via the activation of the forkhead box O3a-silent mating type information regulation 2 homolog 6(FoxO3a-Sirt6)axis,with no impact on the sterol regulatory element binding protein 2 and 3-hydroxy-3-methylglutaryl-CoA reductase(SREBP2-HMGCR)pathway.Conclusion:Our study sheds light on the paradigm of"Exercise is Medicine",providing evidence to support the use of statins combined with exercise in reducing LDL-C levels,and unveils potential avenues for clinical applications of sEH inhibitors,presenting novel prospects for therapeutic interventions in ASCVD.
基金supported by the National Natural Science Foundation of China(81560059,81760058,8160042,and 31800891)。
文摘Patients with glioma have a very high mortality rate,thus improving the poor prognosis of glioma has been the goal in the therapeutic field.Searching for more effective drugs for gliomas from natural compounds is a promising strategy.In this study,both oleanonic acid and oleanolic acid inhibited proliferation of glioma cells and reduced expression of cyclin D1 and E1,but the former has a lower IC_(50)than the latter.Oleanonic acid reduced the expression of p-STAT3 but not p-STAT1 and 5,and also reducing the expression of STAT3 in the nucleus and its transcriptional activity in glioma cells.Furthermore,knockdown of STAT3 expression inhibited proliferation and migration of glioma cells.Next,the expressions of the upstream regulators such as SIRT6 and p-JAK2 but not SIRT1,p-ERK1/2,p300 were increased by oleanonic acid.The overexpression of SIRT6 not only reduced the expression of p-STAT3 and its transcriptional activity but also inhibited the proliferation and migration of glioma cells.In addition,the effects that oleanonic acid reduced the expression of p-STAT3 and its transcriptional activity and inhibited the proliferation and migration were attenuated by the knockdown of SIRT6.Furthermore,oleanonic acid effectively suppressed glioma growth and extended survival in nude mice bearing intracerebral U87 xenografts,but not in nude mice bearing intracerebral SIRT6-knockdown U87xenografts.In conclusion,oleanonic acid upregulates the expression of SIRT6 to inactivates STAT3 and then inhibits glioma growth.
