CAJ | 학술논문

目的：研究糖尿病心肌病（DCM）模型大鼠心肌组织中X-盒结合蛋白1（XBP1）与心肌细胞凋亡之间的联系，以及明确缬沙坦抑制心肌细胞凋亡的作用机制。方法：将清洁级雄性8周龄Wistar大鼠50只随机分为两部分：腹腔注射65 mg/kg的柠檬酸盐缓冲液的大鼠为对照组（n=10）；腹腔注射链脲佐菌素65 mg/kg大鼠（n=40）注射7天后，收集大鼠尾静脉血测空腹血糖，其中37只连续2次空腹血糖≥16.7mmol/L（300mg/dl）为DCM大鼠建模成功并将其随机分为2组：给予以生理盐水灌胃的为DCM组（n=20）,以30mg/kg·d灌胃缬沙坦给药的为DCM+缬沙坦组（n=17）。三组大鼠饲养过程中检测体重、血糖、血压、心功能等指标变化。大鼠16周后处死观察心肌组织结构、细胞形态、胶原分布情况，TUNEL染色观察心肌细胞凋亡，并通过免疫荧光、蛋白印迹法（Western blot）、实时定量逆转录-聚合酶链反应（RT-PCR）及半定量RT-PCR检测各组大鼠心肌组织中cytochrome c、cleaved caspase 3、葡萄糖调节蛋白78（GPR78）和剪接型XBP1（XBP1-s）表达水平。结果：DCM组大鼠与对照组相比，心肌结构紊乱，胶原含量明显增加，心肌细胞凋亡增加（P<0.05），GRP78、XBP1-s、cleaved caspase 3和cytochrome c蛋白及核糖核酸（RNA）表达水平明显升高（P<0.05），DCM+缬沙坦组与DCM组相比，心肌细胞排列较整齐，心肌间质内和小动脉周围胶原纤维显著减少，心肌细胞凋亡明显减少（P<0.05），GRP78、XBP1-s、cleaved caspase 3和cytochrome c蛋白及RNA表达水平明显下降（P<0.05）。结论：DCM大鼠心肌组织中存在着调节内质网应激的关键因子-XBP1的活化，DCM病程中存在着XBP1调控的内质网应激相关凋亡途径的激活，心肌细胞凋亡增加，而缬沙坦能够抑制DCM大鼠心肌细胞XBP1的激活，减少心肌细胞凋亡。
목적：연구당뇨병심기병（DCM）모형대서심기조직중X-합결합단백1（XBP1）여심기세포조망지간적련계，이급명학힐사탄억제심기세포조망적작용궤제。방법：장청길급웅성8주령Wistar대서50지수궤분위량부분：복강주사65 mg/kg적저몽산염완충액적대서위대조조（n=10）；복강주사련뇨좌균소65 mg/kg대서（n=40）주사7천후，수집대서미정맥혈측공복혈당，기중37지련속2차공복혈당≥16.7mmol/L（300mg/dl）위DCM대서건모성공병장기수궤분위2조：급여이생리염수관위적위DCM조（n=20）,이30mg/kg·d관위힐사탄급약적위DCM+힐사탄조（n=17）。삼조대서사양과정중검측체중、혈당、혈압、심공능등지표변화。대서16주후처사관찰심기조직결구、세포형태、효원분포정황，TUNEL염색관찰심기세포조망，병통과면역형광、단백인적법（Western blot）、실시정량역전록-취합매련반응（RT-PCR）급반정량RT-PCR검측각조대서심기조직중cytochrome c、cleaved caspase 3、포도당조절단백78（GPR78）화전접형XBP1（XBP1-s）표체수평。결과：DCM조대서여대조조상비，심기결구문란，효원함량명현증가，심기세포조망증가（P<0.05），GRP78、XBP1-s、cleaved caspase 3화cytochrome c단백급핵당핵산（RNA）표체수평명현승고（P<0.05），DCM+힐사탄조여DCM조상비，심기세포배렬교정제，심기간질내화소동맥주위효원섬유현저감소，심기세포조망명현감소（P<0.05），GRP78、XBP1-s、cleaved caspase 3화cytochrome c단백급RNA표체수평명현하강（P<0.05）。결론：DCM대서심기조직중존재착조절내질망응격적관건인자-XBP1적활화，DCM병정중존재착XBP1조공적내질망응격상관조망도경적격활，심기세포조망증가，이힐사탄능구억제DCM대서심기세포XBP1적격활，감소심기세포조망。
Objective: To study the relationship between myocardial X-box binding protein 1 (XBP1) expression and myocardial apoptosis in experimental diabetic cardiomyopathy (DCM) rat’s model and to clarify the mechanism of valsartan inhibiting myocardial apoptosis. Methods: A total of 50 Wistar rats were divided into 2 groups: Control group, the rats received intraperitoneal citrate buffer at 65mg/kg,n=10 and Streptozotocin group, the rats received intraperitoneal streptozotocin at 65mg/kg,n=40, all animals were treated for 7 days. DCM model was established in 37 rats (fasting blood glucose ≥ 16.7mmole/L) and they were further divided into 2 groups: DCM group, the rats received intragastric normal saline,n=20 and DCM + valsartan group, the rats received intragastric valsartan at 30mg/kg·day,n=17. The rats were treated for 16 weeks. The body weight, tail blood pressure, glucose and cardiac function were compared among 3 groups. Myocardial apoptosis was detected by TUNEL staining, RNA and protein expressions of myocardial cytochrome C, cleaved caspase 3, glucose regulation protein 78 (GRP78) and XBP1-s were examined by immunolfuorescence, real time RT-PCR and Western blot analysis. Results: Compared with Control group, DCM group showed disordered cardiac structure, more collagen content and myocardial apoptosis,P<0.05; increased RNA and protein expressions of GRP78, XBP1-s, cleaved caspase 3 and cytochrome C,P<0.05. Compared with DCM group, DCM + valsartan group had rather regularly arranged myocardiocytes, less interstitial ifbrosis and myocardial apoptosis,P<0.05; decreased RNA and protein expressions of GRP78, XBP1-s, cleaved caspase 3 and cytochrome C,P<0.05. Conclusion: Valsartan may inhibit myocardial XBP1 activation and therefore, reduce the myocardial apoptosis in experimental DCM rat’s model.