Zhang Haifeng, Li Shanshan, Zhou Qiulian, Sun Qi, Shen Shutong, Zhou Yanli, Bei Yihua, Li Xinli
Cell Physiol Biochem. 2016;38(5):1743-51. doi: 10.1159/000443113. Epub 2016 May 9.
BACKGROUND/AIMS: Qiliqiangxin (QL), a traditional Chinese medicine, has long been used to treat chronic heart failure. Previous studies demonstrated that QL could prevent cardiac remodeling and hypertrophy in response to hypertensive or ischemic stress. However, little is known about whether QL could modulate cardiac hypertrophy in vitro, and (if so) whether it is through modulation of specific hypertrophy-related microRNA.
The primary neonatal rat ventricular cardiomyocytes were isolated, cultured, and treated with phenylephrine (PE, 50 µmol/L, 48 h) to induce hypertrophy in vitro, in the presence or absence of pretreatment with QL (0.5 µg/ml, 48 h). The cell surface area was determined by immunofluorescent staining for α-actinin. The mRNA levels of hypertrophic markers including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and β-myosin heavy chain (MYH7) were assayed by qRT-PCRs. The protein synthesis of cardiomyocytes was determined by the protein/DNA ratio. The miR-199a-5p expression level was quantified in PE-treated cardiomyocytes and heart samples from acute myocardial infarction (AMI) mouse model. MiR-199a-5p overexpression was used to determine its role in the anti-hypertrophic effect of QL on cardiomyocytes.
PE induced obvious enlargement of cell surface in cardiomyocytes, paralleling with increased ANP, BNP, and MYH7 mRNA levels and elevated protein/DNA ratio. All these changes were reversed by the treatment with QL. Meanwhile, miR-199a-5p was increased in AMI mouse heart tissues. Of note, the increase of miR-199a-5p in PE-treated cardiomyocytes was reversed by the treatment with QL. Moreover, overexpression of miR-199a-5p abolished the anti-hypertrophic effect of QL on cardiomyocytes.
QL prevents PE-induced cardiac hypertrophy. MiR-199a-5p is increased in cardiac hypertrophy, while reduced by treatment with QL. miR-199a-5p suppression is essential for the anti-hypertrophic effect of QL on cardiomyocytes.
背景/目的：芪苈强心（QL）是一种传统中药，长期用于治疗慢性心力衰竭。先前的研究表明，QL可以预防高血压或缺血应激引起的心脏重塑和肥大。然而，关于QL是否能在体外调节心肌肥大，以及（如果可以）是否通过调节特定的肥大相关微小RNA，人们了解甚少。
分离、培养原代新生大鼠心室心肌细胞，在有或没有QL预处理（0.5μg/ml，48小时）的情况下，用去甲肾上腺素（PE，50μmol/L，48小时）处理以在体外诱导肥大。通过α-肌动蛋白的免疫荧光染色测定细胞表面积。通过qRT-PCR测定包括心房利钠肽（ANP）、脑利钠肽（BNP）和β-肌球蛋白重链（MYH7）在内的肥大标志物的mRNA水平。通过蛋白质/DNA比值测定心肌细胞的蛋白质合成。在PE处理的心肌细胞和急性心肌梗死（AMI）小鼠模型的心脏样本中定量miR-199a-5p表达水平。使用miR-199a-5p过表达来确定其在QL对心肌细胞的抗肥大作用中的作用。
PE诱导心肌细胞的细胞表面积明显增大，同时ANP、BNP和MYH7 mRNA水平升高，蛋白质/DNA比值升高。用QL处理可逆转所有这些变化。同时，miR-199a-5p在AMI小鼠心脏组织中增加。值得注意的是，用QL处理可逆转PE处理的心肌细胞中miR-199a-5p的增加。此外，miR-199a-5p的过表达消除了QL对心肌细胞的抗肥大作用。
QL可预防PE诱导的心肌肥大。miR-199a-5p在心肌肥大中增加，而用QL处理可降低。miR-199a-5p的抑制对于QL对心肌细胞的抗肥大作用至关重要。
