SGK1 Signaling Pathways in Vascular Remodeling

血管重塑中的 SGK1 信号通路

• 批准号: 8287102
• 负责人: Sharon C Francis
• 金额: $ 28.02万
• 依托单位: MOREHOUSE SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8287102
• 关键词: Acceleration; Acetylation; Affect; Angioplasty; Animals; Apolipoprotein E; Apoptosis; Apoptotic; Area; Arterial Fatty Streak; Arteries; Atherosclerosis; Attenuated; Biochemical; Bioinformatics; Biological Models; Biology; Blood Vessels; Bromodeoxyuridine; Carotid Arteries; Cell Cycle Progression; Cell Proliferation; Cell Survival; Cell physiology; Cellular biology; DNA Nucleotidylexotransferase; Data; Deacetylase; Deoxyuridine; Development; Electrophoresis; Epithelial Cells; Genes; Glucocorticoids; Growth; Histone Deacetylase; Homologous Gene; Hypertension; In Vitro; Inflammatory; Injury; Knock-out; Knockout Mice; Knowledge; Label; Lesion; Light; Link; Mass Spectrum Analysis; Mating Types; Mediating; Mediator of activation protein; Mitochondria; Modeling; Molecular; Orthologous Gene; Pathology; Pathway interactions; Phenotype; Phosphorylation; Phosphotransferases; Play; Post-Translational Protein Processing; Process; Productivity; Protein Microchips; Protein-Serine-Threonine Kinases; Proteome; Proteomics; RNA; Rattus; Reaction; Regulation; Research; Resources; Role; Serine; Serum; Signal Pathway; Signal Transduction; Site; Smooth Muscle Myocytes; Stroke; TdT-Mediated dUTP Nick End Labeling Assay; Testing; Up-Regulation; Vascular Diseases; Vascular remodeling; Work; base; cell growth; cell type; gain of function; genetic regulatory protein; in vivo; in vivo Model; injured; insight; loss of function; mRNA Expression; migration; mouse model; mutant; neoplastic cell; new therapeutic target; novel; protein expression; protein function; public health relevance; research study; response; restenosis; stable cell line; two-dimensional; vascular smooth muscle cell proliferation

DESCRIPTION (provided by applicant): Aberrant vascular smooth muscle cells (SMC) proliferation and survival is a hallmark vascular pathology underlying atherosclerosis and restenosis following vascular injury. Mitogenic signaling cascades that become activated upon injury stimulate serine/threonine protein kinases that rapidly regulate the phosphorylation of key genes and regulatory proteins that control cell cycle progression and cell survival processes. In this regard, emerging data indicate that the activity of serum and glucocorticoid inducible kinase 1 (SGK1) is linked to changes in cellular proliferation and survival processes in tumor cells. Although much progress has been made regarding the role of SGK1 in epithelial cell biology; its role in vascular smooth muscle cell function and in the development of lesion formation; in particular, is completely unknown. We have shown that over-expression of activated SGK1 induces a proliferative and survival phenotype in A7r5 rat aortic SMC. This correlated with an acceleration of cell cycle progression owing to an increase in G1 to S transition. Further, we found that SGK1 activity is enhanced in injured carotid arteries. To elucidate the molecular mechanism underlying these effects, we conducted a kinase substrate protein microarray to screen for novel SGK1 targets. Our initial studies identified the mitochondrial deacetylase, Sirt3 as a putative SGK1 target. In light of these findings, we hypothesize that SGK1 promotes neointimal lesion development in vivo by stimulating vascular SMC growth and inhibiting vascular SMC apoptosis via a mechanism that relies upon SGK1-mediated phosphorylation of Sirt3 and modulation of mitochondrial function. To test this hypothesis, we established a unique SMC-specific SGK1 knockout mouse model. We will use SMC isolated from this model as well as SMC stable cell lines in loss- and gain-of-function experiments. In addition, we will utilize these resources as we examine the following specific aims: 1) to test the hypothesis that vascular SMC-targeted knockout of SGK1 attenuates the development of neointimal formation in response to wire-induced vascular injury, 2) to test the hypothesis that SGK1 can directly phosphorylate Sirt3 and thereby regulate its protein function, 3) to demonstrate that a SGK1/Sirt3 signaling pathway is a critical determinant of vascular SMC growth and survival. PUBLIC HEALTH RELEVANCE: This proposal seeks to identify SGK1 as an important mediator of vascular occlusion that occurs as a consequence of arterial stenting or angioplasty. In addition, it will provide insight into the molecular mechanisms responsible for the actions of SGK1 in vascular smooth muscle cells. Ultimately, these studies may identify SGK1 as a novel therapeutic target for occlusive vascular diseases that occur as a consequence of atherosclerosis, restenosis or hypertension.

描述（由申请方提供）：异常血管平滑肌细胞（SMC）增殖和存活是血管损伤后动脉粥样硬化和再狭窄的标志性血管病理学。在损伤时被激活的促有丝分裂信号级联刺激丝氨酸/苏氨酸蛋白激酶，其快速调节控制细胞周期进程和细胞存活过程的关键基因和调节蛋白的磷酸化。在这方面，新出现的数据表明，血清和糖皮质激素诱导激酶1（SGK 1）的活性与肿瘤细胞中细胞增殖和存活过程的变化有关。尽管关于SGK 1在上皮细胞生物学中的作用已经取得了很大进展，但其在血管平滑肌细胞功能和病变形成发展中的作用尤其是完全未知。我们已经表明，激活SGK 1的过度表达诱导A7 R5大鼠主动脉SMC的增殖和存活表型。这与由于G1至S转变的增加而加速细胞周期进程相关。此外，我们发现SGK 1活性在受损的颈动脉中增强。为了阐明这些作用的分子机制，我们进行了激酶底物蛋白芯片筛选新的SGK 1靶点。我们的初步研究确定了线粒体脱乙酰酶，Sirt 3作为一个假定的SGK 1的目标。根据这些发现，我们假设SGK 1通过依赖于SGK 1介导的Sirt 3磷酸化和线粒体功能调节的机制刺激血管SMC生长和抑制血管SMC凋亡来促进体内新生内膜病变的发展。为了验证这一假设，我们建立了独特的SMC特异性SGK 1敲除小鼠模型。我们将使用从该模型中分离的SMC以及SMC稳定细胞系进行功能丧失和获得实验。此外，我们将利用这些资源来审查以下具体目标：1）检验SGK 1的血管SMC靶向敲除响应于导丝诱导的血管损伤而减弱新生内膜形成的发展的假设，2）检验SGK 1可以直接磷酸化Sirt 3并由此调节其蛋白质功能的假设，3）证明SGK 1/Sirt 3信号通路是血管SMC生长和存活的关键决定因素。 公共卫生相关性：该提案旨在确定SGK 1作为动脉支架植入术或血管成形术导致的血管闭塞的重要介质。此外，它将提供深入了解负责血管平滑肌细胞中SGK 1作用的分子机制。最终，这些研究可能将SGK 1确定为动脉粥样硬化、再狭窄或高血压导致的闭塞性血管疾病的新治疗靶点。