ADAMTS-1在酒精性心肌病大鼠心室重构中的作用研究

目的:观察含凝血酶敏感蛋白序列的解整合素-金属蛋白酶-1(ADAMTS-1)在酒精性心肌病(ACM)大鼠心室肌中的表达变化及其与心室重构的关系。方法:将50只健康雄性Wistar大鼠随机分为对照组(n=20)和ACM组(n=30)。ACM组大鼠第1周每天给予10%酒精随意饮用,60%酒精灌胃1次(5 mL/kg);第2周每天给予10%酒精随意饮用,60%酒精灌胃2次(10 mL/kg);第3周~16周每天给予20%酒精随意饮用,60%酒精灌胃2次(15 mL/kg),第17周~6个月每天给予30%酒精随意饮用,60%酒精灌胃2次(15 mL/kg)。对照组大鼠采用普通水随意饮用,以同样方式给予普通水灌胃。实验开始前及6个月时超声心动图检测左心室射血分数(LVEF)、左心室舒张末期直径(LVEDD)和短轴缩短率(FS)。6个月后处死动物,光镜下观察心肌病理组织学改变;Masson染色检测心肌胶原分布及胶原容积分数(CVF);TUNEL法检测心肌细胞凋亡。免疫组化法测定心室肌中ADAMTS-1及其底物多配体蛋白聚糖-4(Syndecan-4)的蛋白含量。结果:与对照组相比,ACM组大鼠LVEF(P0.01)及FS(P0.05)明显降低,而LVEDD显著增加(P0.05);心肌细胞肥大,排列紊乱,部分心肌细胞脂肪变性;心肌纤维断裂、溶解;心肌间质血管扩张充血,胞外间隙明显增宽,纤维组织增生,炎性细胞浸润;CVF及凋亡指数显著增加(P0.01);ADAMTS-1及Syndecan-4蛋白表达显著上调(P0.05)。结论:ADAMTS-1在ACM心肌中表达明显增多,可能通过水解释放Syndecan-4,促进ECM重塑、心肌纤维化及细胞凋亡,参与ACM心室重构过程。

Role of ADAMTS-1 in the Ventricular Remodeling of Rats with Alcoholic Cardiomyopathy

ABSTRACT Objective: To investigate the expression of a disintegrin and metalloprotease with thrombospondin motifs-1 (ADAMTS-1) and its impacts on the ventricular remodeling in rats with alcoholic cardiomyopathy (ACM). Methods: Fifty healthy Wistar rats were randomly divided into the control group (n=20) and the ACM group (n=30). Rats in the ACM group were given 10% alcohol ad libitum as the drinking water and 60% alcohol (5 mL?kg^-1 once per day) by intragastric administration in the first week; 10% alcohol ad libitum as the drinking water and 60% alcohol (10 mL?kg^-1 twice per day) by intragastric administration in the second week; 20% alcohol ad libitum as the drinking water and 60% alcohol (15 mL?kg^-1 twice per day) by intragastric administration from week 3 to week 16; and 30% alcohol ad libitum as the drinking water and 60% alcohol (15 mL?kg^-1 twice per day) by intragastric administration from week 17 to month 6. Animals in the control group received purified drinking water in the same regimen with alcohol treatment. Before and 6 months after initiating the study, left ventricular end diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF), and fractional shortening (FS) were assessed by echocardiography. Histopathology of myocardium was examined with light microscopy; collagen volume fraction (CVF) and apoptotic index were analyzed by Masson staining and TUNEL assay, respectively; and protein expressions of ADAMTS-1 and syndecan-4 were analyzed using immunohistochemistry. Results: Following 6 months of alcohol feeding, compared with the control group, the LVEF and FS overtly reduced in the ACM group (P<0.01 for LVEF and P<0.05 for FS), whereas LVEDD was increased ( P<0.05). In the ACM group, the cardiomyocyte hypertrophy, disorganized cellular arrangement, adipose degeneration, myocardial fiber fracture and myolysis, interstitial vascular dilatation and congestion, extracellular space widening, fibrous proliferation, and inflammatory cell infiltration were observed by light microscopy. In addition, the CVF and apoptotic index were increased dramatically (P<0.01 for both). The protein levels of ADAMTS-1 and Syndecan-4 were higher in the ACM group than those in the control group (P<0.05 for both). Conclusion: ADAMTS-1 is over-expressed in ACM and may mediate the ventricular remodeling by degrading Syndecan-4, including ECM remodeling, myocardial fibrosis and apoptosis.