The Hippo pathway mediates inhibition of vascular smooth muscle cell proliferation by cAMP.
The Hippo pathway mediates inhibition of vascular smooth muscle cell proliferation by cAMP.
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DOI：
10.1016/j.yjmcc.2015.11.024
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发表时间：
2016-01
影响因子：
5
通讯作者：
Bond M
中科院分区：
文献类型：
--
作者：
Kimura TE;Duggirala A;Smith MC;White S;Sala-Newby GB;Newby AC;Bond M
通过细胞内cAMP抑制血管平滑肌细胞（VSMC）增殖可防止过度新生内膜形成，从而防止血管成形术再狭窄和静脉移植物失败。这些保护作用是通过肌动蛋白-细胞骨架重塑和随后的基因表达调控机制介导的，这些机制尚不完全清楚。在这里，我们研究了生长调节Hippo通路的组成部分，特别是转录因子TEAD及其辅助因子雅普和TAZ在VSMC中的作用。使用毛喉素、二丁酰-cAMP或生理激动剂Cicprost或腺苷升高cAMP，显著增加磷酸化和核输出雅普和TAZ，并抑制TEAD-荧光素酶报告基因活性。通过用C3-转移酶抑制RhoA活性，用Y27632抑制其下游激酶ROCK，或用Latrunculin-B抑制肌动蛋白聚合，获得了类似的效果。相反，组成型活性RhoA的表达逆转了毛喉素对TEAD-荧光素酶的抑制作用。毛喉素显着抑制促有丝分裂基因，CCN 1，CTGF，c-MYC和TGFB 2的mRNA表达，这是由组成型活性雅普或TAZ磷酸突变体的表达逆转。用RNAi或Verteporfin抑制雅普和TAZ功能可显著降低VSMC增殖。此外，毛喉素的抗促有丝分裂作用被组成型活性雅普或TAZ的过表达逆转。总之，这些数据表明cAMP诱导的肌动蛋白细胞骨架重塑抑制VSMC中促有丝分裂基因的雅普/TAZ-TEAD依赖性表达。这一机制为cAMP在VSMC中的抗有丝分裂作用提供了新的见解，并提出了一个新的干预靶点。升高的cAMP抑制Rho GTP酶的活性，从而拮抗肌动蛋白聚合。受损的肌动蛋白聚合诱导雅普和TAZ的磷酸化和核输出。雅普和TAZ的核输出降低了TEAD转录因子的活性和TEAD依赖性细胞周期基因的转录。这种机制是cAMP在血管平滑肌细胞中抗有丝分裂作用的基础。升高的cAMP诱导VSMC中雅普和TAZ的磷酸化和核输出。升高的cAMP抑制VSMC中增殖基因的TEAD依赖性转录。雅普和TAZ是VSMC增殖所必需的。cAMP的抗VSMC有丝分裂作用依赖于抑制雅普/TAZ-TEAD介导的基因表达。
Inhibition of vascular smooth muscle cell (VSMC) proliferation by intracellular cAMP prevents excessive neointima formation and hence angioplasty restenosis and vein-graft failure. These protective effects are mediated via actin-cytoskeleton remodelling and subsequent regulation of gene expression by mechanisms that are incompletely understood. Here we investigated the role of components of the growth-regulatory Hippo pathway, specifically the transcription factor TEAD and its co-factors YAP and TAZ in VSMC. Elevation of cAMP using forskolin, dibutyryl-cAMP or the physiological agonists, Cicaprost or adenosine, significantly increased phosphorylation and nuclear export YAP and TAZ and inhibited TEAD-luciferase report gene activity. Similar effects were obtained by inhibiting RhoA activity with C3-transferase, its downstream kinase, ROCK, with Y27632, or actin-polymerisation with Latrunculin-B. Conversely, expression of constitutively-active RhoA reversed the inhibitory effects of forskolin on TEAD-luciferase. Forskolin significantly inhibited the mRNA expression of the pro-mitogenic genes, CCN1, CTGF, c-MYC and TGFB2 and this was reversed by expression of constitutively-active YAP or TAZ phospho-mutants. Inhibition of YAP and TAZ function with RNAi or Verteporfin significantly reduced VSMC proliferation. Furthermore, the anti-mitogenic effects of forskolin were reversed by overexpression of constitutively-active YAP or TAZ. Taken together, these data demonstrate that cAMP-induced actin-cytoskeleton remodelling inhibits YAP/TAZ–TEAD dependent expression of pro-mitogenic genes in VSMC. This mechanism contributes novel insight into the anti-mitogenic effects of cAMP in VSMC and suggests a new target for intervention. Elevated cAMP inhibits the activity of Rho GTPases and thus antagonises actin polymerisation. Impaired actin polymerisation induces the phosphorylation and nuclear export of YAP and TAZ. The nuclear export of YAP and TAZ reduces the activity of TEAD transcription factors and the transcription of TEAD-dependent cell-cycle genes. This mechanism underlies the anti-mitogenic effects of cAMP in vascular smooth muscle cells. Elevated cAMP induces phosphorylation and nuclear export of YAP and TAZ in VSMC. Elevated cAMP inhibits TEAD-dependent transcription of proliferation genes in VSMC. YAP and TAZ are essential for VSMC proliferation. The anti-mitogenic effects of cAMP in VSMC are dependent on inhibition of YAP/TAZ–TEAD mediated gene expression.