CD73在慢性间歇性低氧合并高脂饮食条件下大鼠心脏损伤中的作用

Role of CD73 in cardiac injury in rats with chronic intermittent hypoxia combined with high fat diet

目的研究CD73在间歇性低氧合并高脂饮食条件下大鼠心脏损伤中的表达及意义。方法建立大鼠慢性间歇性低氧合并高脂饮食模型。将SPF级健康雄性Wistar大鼠24只随机分为4组,每组6只。A组(常氧及普通饮食);B组(常氧及高脂饮食);C组(间歇性低氧及普通饮食);D组(间歇性低氧及高脂饮食)。在实验6周后,取各组大鼠血清检测血脂(甘油三酯、低密度脂蛋白胆固醇)水平,光镜下观察大鼠心肌形态学变化,免疫组化和蛋白印迹检测CD73蛋白在各组大鼠心肌细胞中的表达水平。结果 4组大鼠血脂水平比较,差异有统计学意义(均P<0.05)。HE结果显示:A组心肌细胞未见明显异常;B组和C组中可见部分心肌纤维排列紊乱,局灶性变性坏死;D组心肌细胞损伤最为明显,可见肌纤维排列紊乱,纵横纹不清,部分肌纤维明显溶解。免疫组化显示,与A组比较,B、C、D组心肌细胞CD73蛋白表达水平均明显升高(均P<0.01);与B组和C组比较,D组CD73蛋白表达水平明显升高(均P<0.01)。蛋白印迹也显示出一致的结果:与A组比较,B、C组CD73蛋白表达水平均显著升高(均P<0.05),D组CD73蛋白表达水平升高更为显著(P<0.01);与B组和C组比较,D组CD73蛋白表达水平明显升高(均P<0.01)。结论慢性间歇性低氧、高脂饮食可以引起心肌细胞的损伤和心肌细胞中CD73表达上调。

ObjectiveTo investigate the expression and significance of CD73 in rats with intermittent hypoxia and high fat diet.MethodsThe rat model of chronic intermittent hypoxia combined with high fat diet was established. Twenty-four healthy male Wistar rats in the SPF level were randomly divided into 4 group, with 6 rats in each group, namely group A （normoxia and normal diet）, group B （normoxia and high fat diet）, group C （intermittent hypoxia and normal diet）and group D （intermittent hypoxia and high-fat diet）. After 6 weeks of experiment, the serum lipid levels, myocardial morphological changes under microscope, the expression level of CD73 protein detected byimmunohistochemistry and Western blot in myocardial cells in rats were compared among these groups.ResultsThe serum lipid levels were significantly different among these groups （P〈0.05）. HE results showed that the myocardial cells of group A had no obvious abnormalities; disorganized visible myocardial fibers with focal necrosis in groups B and C; myocardial cell injury was most obvious in group D, in which visible muscle fibers arranged in disorder, and grain was not clear, part of the muscle fibers were dissolved predominantly. Compared with group A, CD73 protein expression levels in myocardial cells in groups B, C, and D were significantly elevated （P〈0.01）. Furthermore, CD73 protein expression level in myocardial cells in group D was significantly higher than those in groups B and C （P〈0.01）. Western blot showed consistent results as immunohistochemistry： compared with group A, CD73 protein expression levels in groups B, C, and D were significantly elevated （P〈0.05）, and CD73 protein expression level in myocardial cells in group D was significantly higher than those in groups B and C （P〈0.01）.ConclusionChronic intermittent hypoxia and high fat diet can cause myocardial cell damage and upregulate CD73 expression in the cardiomyocytes.