[关键词]
[摘要]
目的 探讨黄芪甲苷对异丙肾上腺素(ISO)致乳鼠心肌细胞肥大的抑制作用及其机制。方法 原代培养新生SD大鼠心肌细胞48 h,分别加入不同浓度的黄芪甲苷、IκBα磷酸化抑制剂BAY11-7082、β-受体阻滞剂普萘洛尔作用30 min,加入ISO 10 μmol/L继续培养48 h。消化分离法及计算机图像分析系统检测细胞体积;考马斯亮蓝法检测细胞中蛋白的量;RT-PCR法检测心肌细胞ANP和TLR4基因的表达;Western blotting法检测心肌细胞TLR4、p65和IκBα蛋白的表达;ELISA法检测细胞外液中TNF-α、IL-6的量。结果 与对照组比较,模型组心肌细胞体积明显增大,总蛋白的量增加,ANP基因、TLR4基因和蛋白、p65蛋白表达上调,IκBα蛋白表达下调,细胞外液中TNF-α、IL-6的量显著增加(P<0.01)。黄芪甲苷、BAY11-7082和普萘洛尔均能有效抑制ISO诱导的心肌细胞肥大,使心肌细胞体积减小,总蛋白的量降低,ANP 基因、TLR4基因和蛋白、p65蛋白表达下调,IκBα蛋白表达上调(P<0.05),且上述作用呈一定的剂量相关性。结论 黄芪甲苷对ISO诱导的心肌细胞肥大有保护作用,其机制可能与抑制TLR4/NF-κB信号通路有关。
[Key word]
[Abstract]
Objective To investigate the protective effect of astragaloside IV (As IV) on myocardial hypertrophy induced by isoproterenol (ISO) and its mechanism. Methods The primary cultures of neonatal rat cardiac myocytes were cultured for 48 h in vitro. The cardiac myocytes were treated with As IV, IκBα phosphorylation inhibitor BAY11-7082, and β-blockers Propranolol for 30 min, followed by 48 h incubation with ISO 10 μmol/L. The cardiomyocyte volume was measured by computer photograph analysis system. Total protein contents were assayed by the method of Bradford. RT-PCR was used to quantify the mRNA expression of ANP and TLR4; Western blotting was used to quantify the expression of TLR4, p65, and IκBα proteins; ELISA was used to quantify TNF-α and IL-6. Results Compared with the control group, the cell size, total protein content, ANP and TLR4 mRNA, TLR4, p65, TNF-α and IL-6 were increased, and expression of IκBα protein was decreased in ISO group (P < 0.01). As IV, BAY11-7082, and Propranolol could remarkably down-regulate the over-expression of the cell size, total protein content, ANP and TLR4 mRNA, TLR4, p65, TNF-α, and IL-6, and increase the expression of IκBα protein (P < 0.05). Conclusion As IV has the protective effect on cardiac hypertrophy induced by ISO, which is partially referring to inhibiting the TLR4/NF-κB signaling pathway and more than attenuating inflammatory effect.
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[基金项目]
国家自然科学基金资助项目(30973898/C190702);辽宁省自然科学基金资助项目(201102141)