Mechanical stretch induces the apoptosis regulator PUMA in vascular smooth muscle cells
Mechanical stretch induces the apoptosis regulator PUMA in vascular smooth muscle cells
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DOI：
10.1093/cvr/cvr280
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发表时间：
2012-01-01
影响因子：
10.8
通讯作者：
Shyu, Kou-Gi
中科院分区：
文献类型：
--
作者：
Cheng, Wen-Pin;Wang, Bao-Wei;Shyu, Kou-Gi
目的探讨内质网应激过程中细胞凋亡调控基因PUMA(P53上调调整子)的表达。周期性拉伸影响血管平滑肌细胞(VSMCs)中PUMA在细胞凋亡过程中的调控机制尚不清楚。我们假设周期性拉伸可促进VSMC中PUMA的表达。方法和结果生长在Flexell I柔性膜上的人VSMCs在1 Hz的频率下经真空拉伸至20%的伸长率。采用成年大鼠在体主动脉-腔静脉分流的容量超负荷和主动脉缩窄的压力超负荷模型，研究PUMA的表达。周期性牵张显著增强了牵张后PUMA蛋白和基因的表达。牵张前30min加入c-jun氨基末端激酶(JNK)抑制剂SP600125和干扰素-g(IFN-γ)抗体可抑制PUMA的表达。凝胶漂移实验显示，牵张增加了干扰素调节因子-1(IRF-1)的DNA结合活性。SP600125、JNK小干扰RNA和干扰素-γ抗体可减弱拉伸诱导的DNA结合活性。Puma-Mut质粒、SP600125和IRF-1抗体可减弱启动子的活性。拉伸可增加VSMCs分泌干扰素-γ，而VSMCs条件培养液可增加PUMA蛋白的表达。在体主动脉-腔静脉分流和主动脉环扎模型中，PUMA蛋白的表达也增加。结论周期性机械牵张可增加培养的人VSMCs中PUMA的表达。Stretch诱导的PUMA表达是通过干扰素-γ、JNK和IRF-1途径介导的。提示PUMA是牵张诱导VSMC凋亡的重要介质。
Aims The expression of PUMA (p53-up-regulated modulator of apoptosis), an apoptosis-regulating gene, increases during endoplasmic reticulum stress. The mechanisms by which cyclic stretch influences the regulation of PUMA in vascular smooth muscle cells (VSMCs) during apoptosis remain unclear. We hypothesized that cyclic stretch enhances PUMA expression in VSMCs undergoing apoptosis.Methods and results Human VSMCs grown on a Flexcell I flexible membrane base were stretched via vacuum to 20% of elongation at a frequency of 1 Hz. An in vivo model of volume overload with aorta-caval shunt and pressure overload with aortic banding in adult rats was used to study PUMA expression. Cyclic stretch markedly enhanced PUMA protein and gene expression after stretch. Addition of c-jun N-terminal kinase (JNK) inhibitor SP600125 and interferon-g (IFN-gamma) antibody 30 min before stretch inhibited PUMA expression. Gel shift assay demonstrated that stretch increased the DNA binding activity of interferon regulatory factor-1 (IRF-1). SP600125, JNK small interfering RNA, and IFN-gamma antibody attenuated the DNA binding activity induced by stretch. PUMA-Mut plasmid, SP600125, and IRF-1 antibody attenuated the promoter activity. Stretch increased secretion of IFN-gamma from VSMCs, and conditioned media from stretched VSMCs increased PUMA protein expression. The in vivo model of aorta-caval shunt and aortic banding also showed increased PUMA protein expression in the aorta.Conclusion Cyclic mechanical stretch increases PUMA expression in cultured human VSMCs. The PUMA expression induced by stretch is mediated by IFN-gamma, JNK, and IRF-1 pathways. These findings suggest that PUMA is an important mediator in VSMC apoptosis induced by stretch.