The actin depolymerizing factor destrin serves as a negative feedback inhibitor of smooth muscle cell differentiation.
The actin depolymerizing factor destrin serves as a negative feedback inhibitor of smooth muscle cell differentiation.
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肌动蛋白解聚因子 destrin 充当平滑肌细胞分化的负反馈抑制剂。
DOI：
10.1152/ajpheart.00142.2021
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Mack,ChristopherP
中科院分区：
文献类型：
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作者：
Liao,KuoAn;Rangarajan,KrsnaV;Bai,Xue;Taylor,JoanM;Mack,ChristopherP
我们以前已经表明，RhoA信号通路的几个组成部分控制平滑肌细胞（SMC）表型通过改变血清反应因子（SRF）依赖的基因表达。由于我们的染色质结构和转录因子结合的全基因组分析表明，肌动蛋白解聚因子，destrin（DSTH），在SMC选择性的方式进行调节，目前的研究的目标是确定DSTH在SMC表达控制的转录机制，并测试它是否调节SMC功能。免疫组织化学分析显示，在许多小鼠组织中，DALDENZ的强表达和至少部分SMC选择性表达，这一结果与来自基因型-组织表达（GTEx）联盟的人类数据一致。我们鉴定了几个控制DALG表达的调控区域，包括由心肌蛋白相关转录因子A（MRTF-A）激活的SMC选择性增强子、免疫球蛋白κ-J区重组信号结合蛋白（RBPJ）和SMAD转录因子。事实上，增强子活性和内源性DIFF 1表达通过RhoA和转化生长因子-β（TGF-β）信号传导上调，并通过抑制Notch切割下调。我们还发现，在体内颈动脉损伤和血小板衍生生长因子-BB（PDGF-BB）治疗培养的SMC细胞中，DAPK表达降低。siRNA介导的DIFF-A耗竭显著增强了MRTF-A核定位和SMC分化标志物基因表达，减少了划痕试验中的SMC迁移，并减少了SMC增殖，如通过细胞数量和细胞周期蛋白-E表达所测量的。综上所述，我们的数据表明，多巴酚丁胺是一种负反馈抑制剂的RhoA/SRF依赖的基因表达在SMC，协调促进SMC表型调制。靶向DAPs表达或活性的干预可以作为动脉粥样硬化和再狭窄的潜在疗法。新&值得注意的是首先，DAPs以RhoA/SRF依赖的方式选择性地在SMC中表达。第二，SMC选择性增强子正好位于DSTNTSS上游，具有功能性SRF、SMAD和Notch/RBPJ结合元件。第三，DIFFERENTIAL耗竭增加SRF依赖性SMC标记基因表达，同时抑制SMC迁移和增殖。综上所述，我们的数据表明，多巴酚丁胺是一个关键的负反馈抑制SMC分化。
We have previously shown that several components of the RhoA signaling pathway control smooth muscle cell (SMC) phenotype by altering serum response factor (SRF)-dependent gene expression. Because our genome-wide analyses of chromatin structure and transcription factor binding suggested that the actin depolymerizing factor, destrin (DSTN), was regulated in a SMC-selective fashion, the goals of the current study were to identify the transcription mechanisms that control DSTN expression in SMC and to test whether it regulates SMC function. Immunohistochemical analyses revealed strong and at least partially SMC-selective expression of DSTN in many mouse tissues, a result consistent with human data from the genotype-tissue expression (GTEx) consortium. We identified several regulatory regions that control DSTN expression including a SMC-selective enhancer that was activated by myocardin-related transcription factor-A (MRTF-A), recombination signal binding protein for immunoglobulin κ-J region (RBPJ), and the SMAD transcription factors. Indeed, enhancer activity and endogenous DSTN expression were upregulated by RhoA and transforming growth factor-β (TGF-β) signaling and downregulated by inhibition of Notch cleavage. We also showed that DSTN expression was decreased in vivo by carotid artery injury and in cultured SMC cells by platelet-derived growth factor-BB (PDGF-BB) treatment. siRNA-mediated depletion of DSTN significantly enhanced MRTF-A nuclear localization and SMC differentiation marker gene expression, decreased SMC migration in scratch wound assays, and decreased SMC proliferation, as measured by cell number and cyclin-E expression. Taken together our data indicate that DSTN is a negative feedback inhibitor of RhoA/SRF-dependent gene expression in SMC that coordinately promotes SMC phenotypic modulation. Interventions that target DSTN expression or activity could serve as potential therapies for atherosclerosis and restenosis.NEW & NOTEWORTHYFirst, DSTN is selectively expressed in SMC in RhoA/SRF-dependent manner. Second, a SMC-selective enhancer just upstream ofDSTNTSS harbors functional SRF, SMAD, and Notch/RBPJ binding elements. Third, DSTN depletion increased SRF-dependent SMC marker gene expression while inhibiting SMC migration and proliferation. Taken together, our data suggest that DSTN is a critical negative feedback inhibitor of SMC differentiation.