Regulation of Vascular Smooth Muscle Growth

描述(申请人提供)：异常血管平滑肌细胞 血管平滑肌细胞(VSMC)生长与动脉粥样硬化、高血压和 血管再狭窄。这项提案的长期目标是将 介导VSMC生长的信号转导通路的协调调节 并确定生长因子对这些级联的不同调节 和肥大激动剂。VSMC具有肥大和增殖的能力 成长。尽管G-蛋白和G-蛋白都激活了无数的信号通路 偶联受体和受体酪氨酸激酶，鲜为人知 这些信号是整合的，是否共同的受体-近端信号 控制点同步增长和迁移。非受体酪氨酸 激酶PYK2将G蛋白和生长因子受体连接到下游 信号级联。新的初步数据表明，PYK2下调了 反义寡核苷酸阻断血管紧张素Ⅱ(Ang II)和血小板衍生 生长因子(PDGF)诱导的蛋白质和DNA合成与 抑制粘着斑激酶(FAK)、p38和ERK1/2的MAP激酶，AS 磷脂酰肌醇3-激酶/Akt/p70S6激酶通路。假说 目前的提议是PYK2代表一个近端信号事件， 整合(链接)来自GQ偶联受体和受体酪氨酸的信号 参与VSMC生长和调控的下游信号转导通路 迁移。三个具体的目标将检验这一假设：在目标1中，研究 利用反义寡核苷酸和腺病毒构建物将用于 确定蛋白质翻译启动是否需要PYK2，细胞 周期进展和VSMC迁移。在目标2中，使用PYK2反义基因进行实验 ERK1/2、p38和PI3K通路的药物抑制剂将决定 作为响应，PYK2激活下游有哪些细胞信号级联 血管紧张素II和血小板衍生生长因子。在目标3中，显性阴性PYK2腺病毒构建或 PYK2反义寡核苷酸将用于阻断体内VSMC肥大和增殖 采用小鼠颈动脉损伤模型。这一结果可能会提供新的见解 协调VSMC生长调节，并可能确定 靶向近端信号中间体作为潜在的治疗手段 血管疾病的策略。

DESCRIPTION (provided by the applicant): Aberrant vascular smooth muscle cell (VSMC) growth has been implicated in atherosclerosis, hypertension and restenosis. The long-term goal of this proposal is to characterize the coordinated regulation of signal transduction cascades that mediate VSMC growth and to determine differential regulation of these cascades by growth factors and hypertrophic agonists. VSMC are capable of hypertrophic and proliferative growth. Although a myriad of signaling pathways are activated by both G-protein coupled receptors and receptor tyrosine kinases, little is known about how these signals are integrated and whether common receptor-proximal signaling control points synchronize growth and migration. The nonreceptor, tyrosine kinase PYK2 links G-protein- and growth factor receptors to downstream signaling cascades. New preliminary data indicate that PYK2 downregulation by antisense oligonucleotides blocks Angiotensin II- (Ang II) and platelet derived growth factor (PDGF)-induced protein and DNA synthesis that was associated with inhibition of focal adhesion kinase (FAK), the p38 and ERK1/2 MAP kinases, as well the phosphatidylinositol 3-kinase/Akt/p70S6 kinase pathway. The hypothesis of the current proposal is that PYK2 represents a proximal signaling event that integrates (links) signals from both Gq-coupled receptors and receptor tyrosine kinases to control downstream signaling cascades involved in VSMC growth and migration. Three specific aims will test this hypothesis: In Aim 1, studies with antisense oligonucleotides and adenoviral constructs will be used to determine whether PYK2 is required for protein translation initiation, cell cycle progression and VSMC migration. In Aim 2, experiments with PYK2 antisense and pharmacological inhibitors of ERK1/2, p38 and PI3K pathways will determine which cellular signaling cascades are downstream of PYK2 activation in response to Ang II and PDGF. In Aim 3, dominant negative PYK2 adenoviral constructs or PYK2 antisense will be used to block VSMC hypertrophy and proliferation in vivo using a mouse carotid artery injury model. The results may provide new insight coordinated VSMC growth regulation and may determine the feasibility of targeting the proximal signaling intermediates as potential therapeutic strategies for vascular disease.