胰岛素样生长因子（IGF）-I 抵抗诱导的心肌成纤维细胞凋亡依赖于 IGF-II，并被血管紧张素 II 协同增强。

Cardiomyoblast apoptosis induced by insulin-like growth factor (IGF)-I resistance is IGF-II dependent and synergistically enhanced by angiotensin II.

作者信息

Kuo Wei-Wen, Liu Chung-Jung, Chen Li-Ming, Wu Chieh-Hsi, Chu Chun-Hsien, Liu Jer-Yuh, Lu Min-Chi, Lin James A, Lee Shin-Da, Huang Chih-Yang

机构信息

Department of Biological Science and Technology, China Medical University, No. 91 Hsueh-Shih Road, Taichung 404, Taiwan.

出版信息

Apoptosis. 2006 Jul;11(7):1075-89. doi: 10.1007/s10495-006-7028-4.

DOI:10.1007/s10495-006-7028-4

PMID:16699953

Abstract

OBJECTIVE

This study explores the synergistic effect of cardiomyoblast apoptosis induced by angiotensin II (Ang II) and Insulin-like growth factor (IGF)-I resistance, and elucidates the role of IGF-II via IGF-II receptor (R) and calcineurin pathways in apoptosis induced by Ang II and IGF-I resistance.

METHODS

Apoptosis of cultured cardiomyoblast H9c2 cells was assessed by DNA fragmentation on agarose gel electrophoresis, nuclear condensation stained with DAPI, and Western blot analysis of pro-apoptotic Bad and cytochrome c in various combinations of control, Ang II, antisense IGF (I or II), IGF (I or II) antibody, IGF (I or II) receptor (R) antibody, or calcineurin inhibitor (Cyclosporine A, (CsA)).

RESULTS

We found the following: (1) The combination of Ang II and IGF-I deficiencies had a synergistic effect on apoptosis, confirmed by DNA fragmentation, nuclei condensation, and increases in such pro-apoptotic proteins as Bad, cytochrome c, caspase 9, and caspase 3 in H9c2 cells. (2) IGF-II and IGF-IIR protein products were increased by antisense IGF-I and IGF-I resistance, but these IGF-II protein products were not affected by sense IGF-I and non-specific antibody IgG in H9c2 cells. (3) The alteration of Bad protein level and the release of cytochrome c, both induced by treatments containing combinations of Ang II and antisense IGF-I, IGF-I antibody or IGF-IR antibody, were inhibited by IGF-II antibody. (4) DNA fragmentation, Bad, and cytochrome c which was induced by treatments combining IGF-IR antibody with Ang II or combining IGF-IR antibody with IGF-II were remarkably attenuated by CsA.

CONCLUSION

IGF-I deficiency and/or IGF-IR resistance induced apoptosis in cardiomyoblast cells. The apoptosis, which might have been caused by the upregulation of IGF-II and IGF-IIR genes possibly activated the downstream calcineurin pathway, was synergistically augmented by Ang II.

摘要

目的

本研究探讨血管紧张素II（Ang II）诱导的心肌母细胞凋亡与胰岛素样生长因子（IGF）-I抵抗之间的协同作用，并阐明IGF-II通过IGF-II受体（R）和钙调神经磷酸酶途径在Ang II诱导的凋亡及IGF-I抵抗中所起的作用。

方法

通过琼脂糖凝胶电泳检测DNA片段化、用DAPI染色检测核浓缩，以及采用蛋白质免疫印迹法分析凋亡前体蛋白Bad和细胞色素c，评估培养的心肌母细胞H9c2在以下各种组合处理下的凋亡情况：对照组、Ang II、反义IGF（I或II）、IGF（I或II）抗体、IGF（I或II）受体（R）抗体，或钙调神经磷酸酶抑制剂（环孢素A，（CsA））。

结果

我们发现：（1）DNA片段化、核浓缩以及H9c2细胞中凋亡前体蛋白Bad、细胞色素c、半胱天冬酶9和半胱天冬酶3的增加证实，Ang II和IGF-I缺乏共同作用对凋亡具有协同效应。（2）反义IGF-I和IGF-I抵抗使H9c2细胞中的IGF-II和IGF-IIR蛋白产物增加，但正义IGF-I和非特异性抗体IgG对这些IGF-II蛋白产物无影响。（3）IGF-II抗体可抑制由含Ang II与反义IGF-I、IGF-I抗体或IGF-IR抗体的组合处理所诱导的Bad蛋白水平改变及细胞色素c释放。（4）CsA可显著减弱由IGF-IR抗体与Ang II联合处理或IGF-IR抗体与IGF-II联合处理所诱导的DNA片段化、Bad和细胞色素c。