Inhibition of hypoxia-induced apoptosis by modulation of retinoblastoma protein-dependent signaling in cardiomyocytes
Inhibition of hypoxia-induced apoptosis by modulation of retinoblastoma protein-dependent signaling in cardiomyocytes
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DOI：
10.1161/01.res.0000041030.98642.41
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发表时间：
2002-11-01
影响因子：
20.1
通讯作者：
von Harsdorf, R
中科院分区：
文献类型：
--
作者：
Hauck, L;Hansmann, G;von Harsdorf, R
细胞凋亡是导致心脏功能不全的重要细胞死亡方式。为了分析E2 F依赖的基因转录调控在心肌细胞凋亡中的重要性，研究了细胞周期因子对视网膜母细胞瘤蛋白（pRb）/E2 F通路的影响。在分离的新生儿心室肌细胞中，缺氧（去铁胺，100 μ mol/L）诱导的细胞凋亡特异性激活细胞周期蛋白依赖性激酶（cdks）2和3。凋亡性细胞死亡被cdk抑制剂p21（CIP）和p27（KIP 1）的异位表达抑制，但不被p16（INK 4）的异位表达抑制。此外，细胞凋亡也被废除的激酶死亡突变蛋白的cdk 2/3，但不是cdk 4/6的强制表达。cdk抑制剂或显性负性cdk 2/3的引入阻断了pRb的过度磷酸化并废除了E2 F依赖的基因转录，包括促凋亡caspase 3和caspase 7的E2 F响应基因的转录。此外，引入组成型活性pRb和转录惰性突变体E2 F1/DP 1有效地保护心肌细胞免于凋亡。总之，这些数据表明，cdk特异性pRb的失活和随后的激活E2 F依赖的基因转录所需的心肌细胞凋亡。
Apoptotic cell death is an important mode of cell loss contributing to heart dysfunction. To analyze the importance of the E2F-dependent regulation of gene transcription in cardiomyocyte apoptosis, the function of cell cycle factors impinging on the retinoblastoma protein (pRb)/E2F pathway was investigated. In isolated neonatal ventricular myocytes, apoptotic cell death induced by hypoxia (deferoxamine, 100 mumol/L) specifically activated cyclin-dependent kinases (cdks) 2 and 3. Apoptotic cell death was inhibited by ectopic expression of cdk inhibitors p21(CIP) and p27(KIPl) but not p16(INK4). In addition, apoptosis was also abrogated by forced expression of kinase dead mutant proteins of cdk2/3 but not of cdk4/6. Introduction of cdk inhibitors or dominant-negative cdk2/3 blocked pRb hyperphosphorylation and abrogated E2F-dependent gene transcription, including that of the E2F-responsive genes of proapoptotic caspase 3 and caspase 7. Moreover, introduction of constitutively active pRb and transcriptionally inert mutant E2F1/DP1 efficiently protected cardiomyocytes from apoptosis. In conclusion, these data demonstrate that cdk-specific inactivation of pRb and the subsequent activation of E2F-dependent gene transcription are required for cardiomyocyte apoptosis.