扩张型心肌病大鼠心肌α-actin和NF-кB的表达及其与心功能的关系

Relationship between Expressions of α-actin and NF-kappa B and Cardiac Function in Rat Model of Dilated Cardiomyopathy

目的:观察扩张型心肌病(DCM)大鼠心肌骨骼肌型α-肌动蛋白(α-actin)和核因子-кB(NF-кB)的表达及其与心功能的关系。方法:通过腹腔注射阿霉素建立大鼠DCM模型。超声心动图测定左室射血分数(LVEF),RT-PCR检测心肌骨骼肌型α-actin mRNA表达,免疫组化方法检测心肌骨骼肌型α-actin和NF-кB蛋白的表达。结果:(1)与正常大鼠比较:DCM大鼠骨骼肌型α-actin mRNA及蛋白表达均上调(P<0.01);DCM大鼠NF-кB活性增强(P<0.01)。(2)DCM大鼠LVEF与骨骼肌型α-actin mRNA水平呈负相关(r=-0.596,P<0.05);NF-кB活性与LVEF呈负相关(r=-0.738,P<0.01)。结论:DCM大鼠心肌骨骼肌型α-actin表达上调作为心肌细胞肥大的标志,提示左室收缩功能恶化,心肌进行代偿。DCM大鼠心脏局部炎症反应活跃并损害心功能。

Objective： To observe the relationship between expressions of skeletal muscle alphα-actin（α-actin） and NF- kappa B （NF-κB） and cardiac function in rat model of dilated cardiomyopathy （DCM）. Methods： Rats were administered adriamycin intraperitoneaUy to develop DCM. Left ventricular ejection fraction（LVEF） was measured by echocardiogram. The expression of skeletal muscle α-actin mRNA was studied by RT-PCR. The expressions of skeletal muscle α-actin and NF-κB protein were studied by immunohistochemistry. Results： Compared with normal rats, the expression levels of skeletal muscle α-actin mRNA and protein were up-regulated in rats with DCM （P 〈 0.01 ）. The activity of NF-κB was enhanced in the rats with DCM （P 〈 0.01 ）. There was a negative correlation between LVEF and the levels of skeletal muscle α-actin mRNA in rats with DCM （r = -0.596,P 〈 0.05）. The activity of NF-κB had negative correlation with LVEF （r = -0.738,P 〈 0.01）. Conclusion： The up-regulated expression levels of α-actin could be valuable markers of cardiomyocyte hypertrophy,which implies that the cardiac function is aggravated and the myocardium tries to compensate. There is an obvious inflammatory reaction in heart of rats with DCM, which may injure the cardiac function.