MicroRNA-208a(miR-208a)plays critical roles in the severe fibrosis and heart failure post myocardial ischemia/reperfusion(IR)injury.MiR-208a inhibitor(mI)with complementary RNA sequence can silence the expression of m...MicroRNA-208a(miR-208a)plays critical roles in the severe fibrosis and heart failure post myocardial ischemia/reperfusion(IR)injury.MiR-208a inhibitor(mI)with complementary RNA sequence can silence the expression of miR-208a,while it is challenging to achieve efficient and myocardium-targeted delivery.Herein,biomimetic nanocomplexes(NCs)reversibly coated with red blood cell membrane(RM)were developed for the myocardial delivery of mI.To construct the NCs,membrane-penetrating helical polypeptide(PG)was first adopted to condense mI and form the cationic inner core,which subsequently adsorbed catalase(CAT)via electrostatic interaction followed by surface coating with RM.The membrane-coated NCs enabled prolonged blood circulation after systemic administration,and could accumulate in the injured myocardium via passive targeting.In the oxidative microenvironment of injured myocardium,CAT decomposed H_(2)O_(2)to produce O_(2)bubbles,which drove the shedding of the outer RM to expose the positively charged inner core,thus facilitated effective internalization by cardiac cells.Based on the combined contribution of mI-mediated miR-208a silencing and CAT-mediated alleviation of oxidative stress,NCs effectively ameliorated the myocardial microenvironment,hence reducing the infarct size as well as fibrosis and promoting recovery of cardiac functions.This study provides an effective strategy for the cytosolic delivery of nucleic acid cargoes in the myocardium,and it renders an enlightened approach to resolve the blood circulation/cell internalization dilemma of cell membrane-coated delivery systems.展开更多
目的探讨参附注射液抑制大鼠缺血再灌注损伤期间心肌细胞凋亡的作用机制。方法 28只SpragueDawley大鼠分为3组:假手术组(8只)、对照组(10只)和给药组(10只)。建立大鼠心肌缺血再灌注损伤模型。分别采用末端脱氧核苷酸转移酶介导的缺口...目的探讨参附注射液抑制大鼠缺血再灌注损伤期间心肌细胞凋亡的作用机制。方法 28只SpragueDawley大鼠分为3组:假手术组(8只)、对照组(10只)和给药组(10只)。建立大鼠心肌缺血再灌注损伤模型。分别采用末端脱氧核苷酸转移酶介导的缺口末端标记法检测凋亡心肌细胞;免疫组织化学方法检测心肌细胞Bcl-2、Bax蛋白表达;利用Affymetrix Rat 230A芯片进行差异基因表达分析,用Microarray Suite 5.0软件读取并进行数据处理。结果免疫组织化学:与假手术组比较,对照组凋亡细胞表达阳性率显著增加(P<0.001),给药组无显著变化(P>0.05);凋亡因子Bcl-2表达阳性率,对照组略有下降,但差异无统计学意义(P>0.05),给药组显著增加(P<0.01);凋亡因子Bax表达阳性率,对照组显著增加(P<0.001),给药组显著下降(P<0.05)。差异基因表达:给药组与对照组比较,上调表达细胞凋亡相关基因主要为金属硫蛋白基因,下调表达基因主要为蛋白激酶结合蛋白基因、肿瘤坏死因子亚家族基因和p75类凋亡基因。结论参附注射液在大鼠心肌缺血再灌注损伤期间,对心肌细胞的保护作用机制主要是通过抑制心肌细胞凋亡,调节与细胞凋亡相关基因的表达,减轻心肌细胞凋亡的发生,提高心肌细胞的防御能力等而起到保护心肌的作用。展开更多
基金supported by the National Natural Science Foundation of China(Nos.82172076,52273144,and 52033006)111 project,Collaborative Innovation Center of Suzhou Nano Science&Technology,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,and Suzhou Key Laboratory of Nanotechnology and Biomedicine.
文摘MicroRNA-208a(miR-208a)plays critical roles in the severe fibrosis and heart failure post myocardial ischemia/reperfusion(IR)injury.MiR-208a inhibitor(mI)with complementary RNA sequence can silence the expression of miR-208a,while it is challenging to achieve efficient and myocardium-targeted delivery.Herein,biomimetic nanocomplexes(NCs)reversibly coated with red blood cell membrane(RM)were developed for the myocardial delivery of mI.To construct the NCs,membrane-penetrating helical polypeptide(PG)was first adopted to condense mI and form the cationic inner core,which subsequently adsorbed catalase(CAT)via electrostatic interaction followed by surface coating with RM.The membrane-coated NCs enabled prolonged blood circulation after systemic administration,and could accumulate in the injured myocardium via passive targeting.In the oxidative microenvironment of injured myocardium,CAT decomposed H_(2)O_(2)to produce O_(2)bubbles,which drove the shedding of the outer RM to expose the positively charged inner core,thus facilitated effective internalization by cardiac cells.Based on the combined contribution of mI-mediated miR-208a silencing and CAT-mediated alleviation of oxidative stress,NCs effectively ameliorated the myocardial microenvironment,hence reducing the infarct size as well as fibrosis and promoting recovery of cardiac functions.This study provides an effective strategy for the cytosolic delivery of nucleic acid cargoes in the myocardium,and it renders an enlightened approach to resolve the blood circulation/cell internalization dilemma of cell membrane-coated delivery systems.
文摘目的探讨参附注射液抑制大鼠缺血再灌注损伤期间心肌细胞凋亡的作用机制。方法 28只SpragueDawley大鼠分为3组:假手术组(8只)、对照组(10只)和给药组(10只)。建立大鼠心肌缺血再灌注损伤模型。分别采用末端脱氧核苷酸转移酶介导的缺口末端标记法检测凋亡心肌细胞;免疫组织化学方法检测心肌细胞Bcl-2、Bax蛋白表达;利用Affymetrix Rat 230A芯片进行差异基因表达分析,用Microarray Suite 5.0软件读取并进行数据处理。结果免疫组织化学:与假手术组比较,对照组凋亡细胞表达阳性率显著增加(P<0.001),给药组无显著变化(P>0.05);凋亡因子Bcl-2表达阳性率,对照组略有下降,但差异无统计学意义(P>0.05),给药组显著增加(P<0.01);凋亡因子Bax表达阳性率,对照组显著增加(P<0.001),给药组显著下降(P<0.05)。差异基因表达:给药组与对照组比较,上调表达细胞凋亡相关基因主要为金属硫蛋白基因,下调表达基因主要为蛋白激酶结合蛋白基因、肿瘤坏死因子亚家族基因和p75类凋亡基因。结论参附注射液在大鼠心肌缺血再灌注损伤期间,对心肌细胞的保护作用机制主要是通过抑制心肌细胞凋亡,调节与细胞凋亡相关基因的表达,减轻心肌细胞凋亡的发生,提高心肌细胞的防御能力等而起到保护心肌的作用。
