PTH-RELATED PROTEIN IN VASCULAR SMOOTH MUSCLE

血管平滑肌中的 PTH 相关蛋白

• 批准号: 2223894
• 负责人: Thomas L Clemens
• 金额: $ 16.76万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-02-01 至 1996-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2223894
• 关键词: angiotensin II; autocrine; biological signal transduction; gene expression; genetic regulatory element; glycosylation; hormone receptor; hormone regulation /control mechanism; laboratory rat; muscle relaxing factor; muscle tone; parathyroid hormones; peptide hormone analog; radioimmunoassay; receptor binding; tissue /cell culture; transfection; vascular smooth muscle; vasodilators

Parathyroid hormone-related protein (PTHrP) is a newly identified tumor peptide which causes hypercalcemia in patients with the syndrome of humoral hypercalcemia of malignancy. Unlike its relative PTH, PTHrP is produced in many normal tissues and emerging evidence suggests that smooth muscle is a main site of production and activity of PTHrP. Our recent studies show that PTHrP is abundantly expressed in vascular smooth muscle cells and subject to regulation by Ang II and other vasoconstrictor peptides. Since both PTH and PTHrP exhibit vasorelaxant activity, we hypothesize that this protein is produced to counter balance the effects of either humoral or mechanical vasoconstrictor signals. The overall goals of this project, are to: 1) determine the mechanisms which control PTHrP gene expression in vascular smooth muscle; 2) characterize the secreted form(s) of the protein and; 3) study its activity in vascular smooth muscle cells and in intact aortic strips. Using a well characterized rat aortic smooth muscle cell culture model we will study the mechanisms by which Ang II regulates PTHrP gene expression in smooth muscle cells (SMC) and establish the relative importance of transcriptional and post-transcriptional control. Separate studies will apply gene transfer and molecular biological techniques to identify cis-acting elements in the PTHrP promoter and 3' UTR which account for the induction of gene expression. We will also examine regulation of PTHrP expression in rat aortic strips in vitro in response to vasoactive agents. We plan to characterize the secreted forms of PTHrP using region-specific RIAs and determine its glycosylation status. In parallel studies, PTHrP and putative N-and C-terminal fragments will be evaluated for their ability to bind to and activate established intracellular signaling pathways in SMC and to affect selected markers for the differentiated SMC phenotype. We will use specific PTHrP antagonists and the aortic strip technique to directly test the hypothesis of local production of PTHrP. In summary, we believe that our findings will implicate PTHrP as an autocrine regulator of vascular smooth muscle tone and finally explain the long-recognized but under-appreciated effects of PTH-related peptides in this tissue.

甲状旁腺激素相关蛋白（PTHRP）是新鉴定的肿瘤 引起高钙血症患者的肽 恶性肿瘤的体液高钙血症。 与其相对PTH不同，PTHRP是 在许多正常组织和新兴证据中产生的表明 平滑肌是PTHRP生产和活性的主要部位。 我们的 最近的研究表明，PTHRP在血管平滑中充分表达 肌肉细胞，受到Ang II和其他其他的调节 血管收缩肽。 由于PTH和PTHRP均表现出血管长 活性，我们假设产生该蛋白以对抗平衡 体液或机械血管收缩信号的影响。 这 该项目的总体目标是：1）确定哪些机制 控制血管平滑肌中的PTHRP基因表达； 2）表征 蛋白质的分泌形式和； 3）研究其活性 血管平滑肌细胞和完整的主动脉条。 使用井 表征大鼠主动脉平滑肌细胞培养模型我们将研究 ANG II调节光滑中PTHRP基因表达的机制 肌肉细胞（SMC）并确定 转录和转录后控制。 单独的研究将 应用基因转移和分子生物学技术鉴定 PTHRP启动子和3'UTR中的顺式作用元素 基因表达的诱导。 我们还将检查 大鼠主动脉条的PTHRP表达在体外响应血管活性 代理商。 我们计划使用 区域特异性RIA并确定其糖基化状态。 并联 将评估研究，PTHRP和推定的N和C末端片段 因为它们能够结合并激活已建立的细胞内 SMC中的信号通路，并影响选定的标记 分化的SMC表型。 我们将使用特定的PTHRP拮抗剂和 直接检验局部假设的主动脉条技术 PTHRP的生产。 总而言之，我们认为我们的发现将 暗示PTHRP是血管平滑肌音的自分泌调节器 并最终解释了长期认识但未被低估的影响 该组织中与PTH相关的肽。