Background:Myocardial infarction(MI)remains a major global public health challenge.Although advances in reperfusion therapy have reduced acute mortality,post-infarction cardiac remodeling continues to pose a substanti...Background:Myocardial infarction(MI)remains a major global public health challenge.Although advances in reperfusion therapy have reduced acute mortality,post-infarction cardiac remodeling continues to pose a substantial threat to long-term cardiovascular health.Oxidative stress and the ensuing inflammatory response are key drivers of this pathological process,leading to cardiomyocyte death,myocardial fibrosis,and functional impairment.Among the regulatory pathways involved,the kelch-like ECH-associated protein 1(Keap1)/nuclear factor erythroid 2-related factor 2(Nrf2)axis has emerged as a critical therapeutic target for mitigating post-MI cardiac injury.Methods:A murine MI model was established by permanent ligation of the left anterior descending coronary artery.Mice received oral Tongxinbi formula(TXB)at low,medium,or high doses(9/18/36 g/kg)once daily for 28 days.Cardiac function was assessed by echocardiography;myocardial fibrosis by Masson’s trichrome;and endothelial integrity by CD31 immunofluorescence.Plasma markers of endothelial function and inflammation were quantified.In vitro,oxidative stress was induced by H2O2 in vascular endothelial cells and cardiomyocytes,followed by treatment with TXB drug-containing serum.Western blot and RT-qPCR were used to measure components of the Keap1/Nrf2 pathway;ELISA quantified oxidative stress and inflammatory indices.Conditioned-medium experiments evaluated endothelial cell–mediated paracrine protection of cardiomyocytes.Results:TXB significantly improved cardiac function and reduced myocardial fibrosis after MI,in association with preservation of microvascular structure and systemic attenuation of oxidative stress and inflammation.In vitro,TXB activated the endothelial Keap1/Nrf2 pathway,enhanced cellular antioxidant defenses,increased VEGF secretion,and,via endothelial cell-mediated paracrine signaling,alleviated cardiomyocyte injury under oxidative stress.Conclusion:TXB exerts anti-fibrotic and cardioprotective effects by activating Nrf2 signaling and engaging endothelial-mediated paracrine mechanisms,collectively mitigating oxidative stress and inflammation in the post-MI setting.展开更多
基金the Major Special Project of Jiangsu Administration of Traditional Chinese Medicine(Project No.ZT202116)the Key R&D Project of Jiangsu Province(Project No.BE2020727)+2 种基金the Yangzhou Science and Technology Program(Project No.YZ2021062,YZ2024143 and YZ2024194)the Third Batch of Academic Mentorship Program for Senior TCM Experts in Jiangsu Province(Project No.2019028)the 2023 Jiangsu Pharmaceutical Association–Aosaikang Hospital Pharmacy Research Project(Project No.A202333).
文摘Background:Myocardial infarction(MI)remains a major global public health challenge.Although advances in reperfusion therapy have reduced acute mortality,post-infarction cardiac remodeling continues to pose a substantial threat to long-term cardiovascular health.Oxidative stress and the ensuing inflammatory response are key drivers of this pathological process,leading to cardiomyocyte death,myocardial fibrosis,and functional impairment.Among the regulatory pathways involved,the kelch-like ECH-associated protein 1(Keap1)/nuclear factor erythroid 2-related factor 2(Nrf2)axis has emerged as a critical therapeutic target for mitigating post-MI cardiac injury.Methods:A murine MI model was established by permanent ligation of the left anterior descending coronary artery.Mice received oral Tongxinbi formula(TXB)at low,medium,or high doses(9/18/36 g/kg)once daily for 28 days.Cardiac function was assessed by echocardiography;myocardial fibrosis by Masson’s trichrome;and endothelial integrity by CD31 immunofluorescence.Plasma markers of endothelial function and inflammation were quantified.In vitro,oxidative stress was induced by H2O2 in vascular endothelial cells and cardiomyocytes,followed by treatment with TXB drug-containing serum.Western blot and RT-qPCR were used to measure components of the Keap1/Nrf2 pathway;ELISA quantified oxidative stress and inflammatory indices.Conditioned-medium experiments evaluated endothelial cell–mediated paracrine protection of cardiomyocytes.Results:TXB significantly improved cardiac function and reduced myocardial fibrosis after MI,in association with preservation of microvascular structure and systemic attenuation of oxidative stress and inflammation.In vitro,TXB activated the endothelial Keap1/Nrf2 pathway,enhanced cellular antioxidant defenses,increased VEGF secretion,and,via endothelial cell-mediated paracrine signaling,alleviated cardiomyocyte injury under oxidative stress.Conclusion:TXB exerts anti-fibrotic and cardioprotective effects by activating Nrf2 signaling and engaging endothelial-mediated paracrine mechanisms,collectively mitigating oxidative stress and inflammation in the post-MI setting.
文摘目的探究枸杞多糖(Lycium barbarum polysaccharides,LBP)调控核因子E2相关因子2(nuclear factor E2 related factor 2,Nrf2)/谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)通路对缺氧/复氧(hypoxia/reoxygenation,H/R)诱导的心肌细胞铁死亡的影响。方法设置对照组、模型组及LBP低、中、高剂量(25、50、100 mg/L)组和LBP(100mg/L)+Nrf2抑制剂ML385(5μmol/L)组。构建H9c2细胞H/R模型,并给予相应药物处理。采用CCK-8检测细胞活力;采用TUNEL染色检测细胞凋亡;采用试剂盒检测细胞Fe^(2+)、谷胱甘肽(glutathione,GSH)、丙二醛(malondialdehyde,MDA)水平及乳酸脱氢酶(lactate dehydrogenase,LDH)、超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)活性;采用二氢乙锭(dihydroethidium,DHE)荧光探针检测细胞活性氧(reactive oxygen species,ROS)水平;采用透射电镜观察细胞线粒体形态;采用Western blotting检测转铁蛋白受体1(transferrin receptor 1,Tf R1)、二价金属离子转运蛋白1(divalent metal transporter 1,DMT1)、铁蛋白重链1(ferritin heavy chain 1,FTH1)、酰基辅酶A合成酶长链家族成员4(acyl-CoA synthetase long-chain family member 4,ACSL4)、Kelch样ECH相关蛋白1(Kelch like ECH associated protein1,Keap1)、Nrf2、血红素氧合酶-1(heme oxygenase-1,HO-1)、溶质载体家族7成员11(solute carrier family 7 member 11,SLC7A11)、GPX4蛋白表达。结果与对照组比较,模型组细胞活力显著降低(P<0.001),Fe^(2+)、MDA、ROS水平和LDH活性显著升高(P<0.001),GSH水平和SOD、CAT活性显著降低(P<0.001),线粒体缩短、膜密度增高且嵴数量减少,TfR1、Nrf2、HO-1、SLC7A11、GPX4蛋白表达水平显著降低(P<0.001),DMT1、FTH1、ACSL4、Keap1蛋白表达水平显著升高(P<0.001)。与模型组比较,LBP组细胞活力显著升高(P<0.01),Fe^(2+)、MDA、ROS水平和LDH活性显著降低(P<0.05、0.01、0.001),GSH水平和SOD、CAT活性显著升高(P<0.05、0.01、0.001),线粒体形态较为规则,TfR1、Nrf2、HO-1、SLC7A11、GPX4蛋白表达水平显著升高(P<0.01、0.001),DMT1、FTH1、ACSL4、Keap1蛋白表达水平显著降低(P<0.05、0.01、0.001);而ML385能够抑制枸杞多糖对细胞铁死亡的改善作用(P<0.05、0.01、0.001)。结论枸杞多糖可能通过激活Nrf2/GPX4通路改善H/R诱导的心肌细胞铁死亡。
