Department of Medical Education and Research, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
J Biomed Sci. 2012 Aug 3;19(1):72. doi: 10.1186/1423-0127-19-72.
PUMA (p53-up-regulated modulator of apoptosis), an apoptosis regulated gene, increased during endoplasmic reticulum stress. However, the expression of PUMA in cardiomyocytes under mechanical stress is little known. We aimed to investigate the regulation mechanism of PUMA expression and apoptosis induced by mechanical stress in cardiomyocytes.
Aorta-caval (AV) shunt was performed in adult Wistar rats to induce volume overload. Rat neonatal cardiomyocytes were stretched by vacuum to 20% of maximum elongation at 60 cycles/min.
PUMA protein and mRNA were up-regulated in the shunt group as compared with sham group. The increased PUMA protein expression and apoptosis induced by shunt was reversed by treatment with atorvastatin at 30 mg/kg/ day orally for 7 days. TUNEL assay showed that treatment with atorvastatin inhibited the apoptosis induced by volume overload. Cyclic stretch significantly enhanced PUMA protein and gene expression. Addition of c-jun N-terminal kinase (JNK) inhibitor SP600125, JNK small interfering RNA (siRNA) and interferon-γ (INF-γ) antibody 30 min before stretch reduced the induction of PUMA protein. Gel shift assay demonstrated that stretch increased the DNA binding activity of interferon regulatory factor-1. Stretch increased, while PUMA-Mut plasmid, SP600125 and INF-γ antibody abolished the PUMA promoter activity induced by stretch. PUMA mediated apoptosis induced by stretch was reversed by PUMA siRNA and atorvastatin.
Mechanical stress enhanced apoptosis and PUMA expression in cardiomyocytes. Treatment with atorvastatin reversed both PUMA expression and apoptosis induced by mechanical stress in cardiomyocytes.
PUMA（p53 上调凋亡调节剂）是一种凋亡调节基因，在内质网应激时增加。然而，机械应激下心肌细胞中 PUMA 的表达知之甚少。我们旨在研究机械应激诱导心肌细胞中 PUMA 表达和凋亡的调节机制。
通过腹主动脉-腔静脉分流术（AV 分流术）在成年 Wistar 大鼠中诱导容量超负荷。通过真空将新生大鼠心肌细胞拉伸至 60 个循环/分钟的最大伸长率的 20%。
与假手术组相比，分流组的 PUMA 蛋白和 mRNA 上调。阿托伐他汀（30mg/kg/天）治疗可逆转分流引起的 PUMA 蛋白表达增加和凋亡。TUNEL 检测表明阿托伐他汀抑制了容量超负荷诱导的凋亡。周期性拉伸显著增强了 PUMA 蛋白和基因表达。在拉伸前 30 分钟加入 c-jun N 端激酶（JNK）抑制剂 SP600125、JNK 小干扰 RNA（siRNA）和干扰素-γ（INF-γ）抗体，可减少 PUMA 蛋白的诱导。凝胶迁移实验表明，拉伸增加了干扰素调节因子-1 的 DNA 结合活性。拉伸增加，而 PUMA-Mut 质粒、SP600125 和 INF-γ 抗体可消除拉伸诱导的 PUMA 启动子活性。PUMA 介导的拉伸诱导的凋亡可通过 PUMA siRNA 和阿托伐他汀逆转。
机械应激增强了心肌细胞中的凋亡和 PUMA 表达。阿托伐他汀治疗可逆转机械应激诱导的心肌细胞中 PUMA 表达和凋亡。
