SGK1 Signaling Pathways in Vascular Remodeling

血管重塑中的 SGK1 信号通路

• 批准号: 8120194
• 负责人: Sharon C Francis
• 金额: $ 28.3万
• 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/8120194
• 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（由申请人提供）：异常的血管平滑肌细胞（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。损伤后激活的有丝分裂信号级联会刺激丝氨酸/苏氨酸蛋白激酶，从而快速调节控制细胞周期进程和细胞生存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 (SGK1) 的活性与肿瘤细胞的细胞增殖和存活过程的变化有关。尽管 SGK1 在上皮细胞生物学中的作用已经取得了很大进展；它在血管平滑肌细胞功能和病变形成过程中的作用；尤其是完全未知。我们已经证明，激活的 SGK1 的过度表达会诱导 A7r5 大鼠主动脉 SMC 的增殖和存活表型。这与由于 G1 到 S 转变的增加而导致的细胞周期进程加速相关。此外，我们发现受损颈动脉中 SGK1 活性增强。为了阐明这些效应背后的分子机制，我们进行了激酶底物蛋白微阵列来筛选新的 SGK1 靶标。我们的初步研究确定线粒体脱乙酰酶 Sirt3 是假定的 SGK1 靶点。根据这些发现，我们假设 SGK1 通过刺激血管 SMC 生长并通过依赖 SGK1 介导的 Sirt3 磷酸化和线粒体功能调节的机制抑制血管 SMC 凋亡来促进体内新内膜病变的发展。为了验证这一假设，我们建立了独特的 SMC 特异性 SGK1 敲除小鼠模型。我们将在功能丧失和功能获得实验中使用从该模型分离的 SMC 以及 SMC 稳定细胞系。此外，我们将利用这些资源来研究以下具体目标：1) 检验血管 SMC 靶向敲除 SGK1 会减弱响应线诱导血管损伤的新内膜形成的发展这一假设，2) 检验 SGK1 可以直接磷酸化 Sirt3 从而调节其蛋白质功能的假设，3) 证明 SGK1/Sirt3 信号通路是血管平滑肌细胞生长和存活的关键决定因素。 公共健康相关性：该提案旨在将 SGK1 确定为动脉支架置入或血管成形术导致的血管闭塞的重要介质。此外，它将深入了解 SGK1 在血管平滑肌细胞中作用的分子机制。最终，这些研究可能会将 SGK1 确定为动脉粥样硬化、再狭窄或高血压引起的闭塞性血管疾病的新治疗靶点。