CAJ | 학술논문

目的检测内质网应激通路相关分子葡萄糖调节蛋白78(Grp78)及 Grp94在糖尿病心肌病大鼠表达的变化,探讨内质网应激在糖尿病心肌病的作用及葛根素的干预作用及其机制.方法50只 Wistar 大鼠随机分为正常对照组(C 组)10只;另40只予高脂高糖饲养4周后腹腔注射链脲佐菌素(STZ)35mg/kg×4周,制备并选取糖尿病大鼠模型20只,再随机分为糖尿病模型组(M 组)及葛根素给药组[T 组,80mg/(kg·d)给药6周],每组10只.分批处死,20周龄大鼠取血测空腹血糖(FBG)、空腹胰岛素(FINS)及计算胰岛素抵抗指数(HOMA-IR);测大鼠心肌组织检测肌酸激酶(CK)、乳酸脱氢酶(LDH)活力;心肌组织 HE 染色,琼脂糖凝胶电泳法检测DNA 梯形条带,免疫组化法检测 Grp78及 Grp94蛋白表达变化,RT-PCR 测定 Grp78、Grp94mRNA 的表达.结果 M 组、T 组FBG、FINS 和 HOMA-IR 及 CK、LDH 均高于 C 组(均 P<0.05),T 组 FBG、HOMA-IR 及 CK、LDH 较 M 组下降(均 P<0.05).M 组心肌纤维肥大,走形较为紊乱,出现核固缩、裂解及丢失现象,心肌细胞变性、坏死,横纹肌消失;T 组心肌纤维轻度肥大,微血管的管壁、管腔均正常.M 组和 T 组均出现了 DNA 梯形图谱,T 组 DNA 梯状条带较 M 组条带不明显.M 组、T 组大鼠的 Grp78和 Grp94免疫组化阳性指数(IPI)、Grp78mRNA 和 Grp94mRNA 均高于 C 组(均 P<0.01),且 T 组的 Grp78-IPI 和 Grp78mRNA 均低于 M 组(均 P<0.01),而 T 组的 Grp94-IPI 和 Grp94mRNA 与 M 组差异无统计学意义(均 P >0.05).结论糖尿病时心肌细胞内质网应激蛋白Grp78、Grp94过强的表达可能参与了糖尿病心肌病的病变过程;葛根素能显著降低升高的血糖,保护受损的心肌,其机制可能是通过降低心肌内质网 Grp78的过强表达.糖尿病心肌病心肌内质网应激蛋白 Grp78可能是葛根素保护作用的靶点之一.
목적검측내질망응격통로상관분자포도당조절단백78(Grp78)급 Grp94재당뇨병심기병대서표체적변화,탐토내질망응격재당뇨병심기병적작용급갈근소적간예작용급기궤제.방법50지 Wistar 대서수궤분위정상대조조(C 조)10지;령40지여고지고당사양4주후복강주사련뇨좌균소(STZ)35mg/kg×4주,제비병선취당뇨병대서모형20지,재수궤분위당뇨병모형조(M 조)급갈근소급약조[T 조,80mg/(kg·d)급약6주],매조10지.분비처사,20주령대서취혈측공복혈당(FBG)、공복이도소(FINS)급계산이도소저항지수(HOMA-IR);측대서심기조직검측기산격매(CK)、유산탈경매(LDH)활력;심기조직 HE 염색,경지당응효전영법검측DNA 제형조대,면역조화법검측 Grp78급 Grp94단백표체변화,RT-PCR 측정 Grp78、Grp94mRNA 적표체.결과 M 조、T 조FBG、FINS 화 HOMA-IR 급 CK、LDH 균고우 C 조(균 P<0.05),T 조 FBG、HOMA-IR 급 CK、LDH 교 M 조하강(균 P<0.05).M 조심기섬유비대,주형교위문란,출현핵고축、렬해급주실현상,심기세포변성、배사,횡문기소실;T 조심기섬유경도비대,미혈관적관벽、관강균정상.M 조화 T 조균출현료 DNA 제형도보,T 조 DNA 제상조대교 M 조조대불명현.M 조、T 조대서적 Grp78화 Grp94면역조화양성지수(IPI)、Grp78mRNA 화 Grp94mRNA 균고우 C 조(균 P<0.01),차 T 조적 Grp78-IPI 화 Grp78mRNA 균저우 M 조(균 P<0.01),이 T 조적 Grp94-IPI 화 Grp94mRNA 여 M 조차이무통계학의의(균 P >0.05).결론당뇨병시심기세포내질망응격단백Grp78、Grp94과강적표체가능삼여료당뇨병심기병적병변과정;갈근소능현저강저승고적혈당,보호수손적심기,기궤제가능시통과강저심기내질망 Grp78적과강표체.당뇨병심기병심기내질망응격단백 Grp78가능시갈근소보호작용적파점지일.
[ ] Objective To investigate the effect of puerarin on endoplasmic reticulum stress (ER stress) in rats with diabet-ic cardiomyopathy (DCM). Methods Wistar rats were fed with high fat and sugar for 4 weeks, then intraperitoneal y injected with streptozotocin (STZ) [35mg/kg×4 weeks] to induce diabetes. Twenty diabetic rats were divided into two groups: diabetic model group (group M, n=10) and puerarin treatment group (group T, n=10), the rats in T group were also intraperitoneal y injected 80 mg/(kg·d)puerarin for 6 weeks. Another 10 normal rats served as controls (group C). Al the rats were sacrificed and blood sam-ples were col ected for measuring fasting blood glucose(FBG), fasting insulin (FINS) and insulin resistance index (HOMA-IR). The myocardial tissue samples were obtained for detecting CK and LDH activity. Tissue samples were dyed with Hematoxylin-eosin (HE) for histopathological examination. DNA ladder was detected by agarose gel electrophoresis; the expressions of Grp78mRNA and Grp94mRNA were detected by RT-PCR. Results The levels of FBG, FINS, HOMA-IR, CK and LDH in groups M and T were significantly higher than those in group C (al P<0.05). The FBG, HOMA-IR, CK and LDH in group T were significantly lower than those in group M (all P<0.05). In Group M: myocardial fibers were hypertrophic and out of shape; cel nucleus were condensed, fragmented and lost. Myocardial cel s were degenerated, necrosed and striated muscles disappeared. In group T: myocardial fibers were mildly hypertrophic; capil ary wal s and lumens were normal. Agarose gel electrophoresis showed DNA ladder both in groups M and T, however the ladder was more apparent in group M than in group T. The immunohistochemistry positive index (IPI)of Grp78 and Grp94, the expression of Grp78mRNA and Grp94mRNA in M and T group were significantly higher than those in group C. Expression of Grp78-IPI and Grp78mRNA in group T was significantly lower than in group M, while there were no significant differences in Grp94-IPI and Grp94mRNA between groups T and M. Conclusion The endoplasmic reticulum stress proteins Grp78 and Grp94 are expressed strongly in cardiomyocytes in diabetic rats, which may be involve in pathological pro-cesses of diabetic cardiomyopathy. Puerarin can decrease high blood sugar and protect myocardium, which may be associated with down-regulation of Grp78 expression in cardiomyocytes.