Adenovirus-mediated overexpression of caveolin-3 inhibits rat cardiomyocyte hypertrophy
Adenovirus-mediated overexpression of caveolin-3 inhibits rat cardiomyocyte hypertrophy
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DOI：
10.1161/01.hyp.0000082926.08268.5d
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发表时间：
2003-08-01
期刊：
影响因子：
8.3
通讯作者：
Imaizumi, T
中科院分区：
文献类型：
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作者：
Koga, A;Oka, N;Imaizumi, T
小窝是细胞表面的Ω形细胞器。蛋白质小窝蛋白-3，心脏小窝的结构组成部分，与细胞信号。为了研究腺病毒介导的caveolin-3过表达对心肌细胞肥大反应的影响，我们构建了编码人野生型caveolin-3的腺病毒（Ad. Cav-3）、突变小窝蛋白-3（Ad. Cav-3Delta）或细菌β-半乳糖苷酶（Ad. LacZ）。据报道，该突变体可引起人类肢带型肌营养不良症。它在小窝蛋白支架结构域中缺少9个核苷酸，并且以显性负性方式表现。用病毒感染大鼠新生心肌细胞，然后在感染后36小时收获。在未感染的细胞中，苯肾上腺素（PE）和内皮素-1（ET）增加细胞大小和[H-3]亮氨酸掺入，沿着诱导肌节重组和β-肌球蛋白重链的重新表达，表明肌细胞肥大。感染Ad。LacZ对这些参数没有影响。Ad. Cav-3阻止了PE和ET诱导的细胞大小增加、亮氨酸掺入、肌节重组和β-肌球蛋白重链重新表达。Ad. Cav-3还阻断PE和ET诱导的细胞外信号调节激酶（ERK）的磷酸化，但不影响c-Jun氨基末端激酶和p38丝裂原活化蛋白激酶活性。相反，AD。Cav-3Delta显著增强了对ET的肥大反应，这与ET诱导的ERK 1/2磷酸化增加有关。这些结果表明，小窝蛋白-3的行为作为一个负调节肥大反应，可能通过抑制ERK 1/2活性。
Caveolae are omega-shaped organelles of the cell surface. The protein caveolin-3, a structural component of cardiac caveolae, is associated with cellular signaling. To investigate the effect of adenovirus-mediated overexpression of caveolin-3 on hypertrophic responses in cardiomyocytes, we constructed an adenovirus that encoded human wild-type caveolin-3 (Ad. Cav-3), mutant caveolin-3 (Ad. Cav-3Delta), or bacterial beta-galactosidase (Ad. LacZ). This mutant has been reported to cause human limb-girdle muscular dystrophy. It lacks 9 nucleotides in the caveolin scaffolding domain and behaves in a dominant-negative fashion. Rat neonatal cardiomyocytes were infected with the virus and then harvested 36 hours after infection. In noninfected cells, phenylephrine ( PE) and endothelin-1 ( ET) increased cell size and [H-3] leucine incorporation, along with the induction of sarcomeric reorganization and the reexpression of beta-myosin heavy chain, indicating myocyte hypertrophy. Infection with Ad. LacZ had no effect on those parameters. Ad. Cav-3 prevented the PE- and ET-induced increases in cell size, leucine incorporation, sarcomeric reorganization, and reexpression of beta-myosin heavy chain. Ad. Cav-3 also blocked the PE- and ET-induced phosphorylations of extracellular signal - regulated kinases ( ERKs) but did not affect c-Jun amino-terminal kinase and p38 mitogen-activated protein kinase activities. In contrast, Ad. Cav-3Delta significantly augmented hypertrophic responses to ET, which were associated with increased ET-induced phosphorylation of ERK1/2. These results suggest that caveolin-3 behaves as a negative regulator of hypertrophic responses, probably through suppression of ERK1/2 activity.