RPG: Proteoglycans: Secondary Regulators of Growth Factor Activity

小行星9629100 这是一项针对女科学家和女工程师的研究规划补助金。 本研究的总体目标是了解局部细胞环境如何影响生长因子对靶刺激细胞的可及性。 IGF-I是一种内分泌因子，几乎仅存在于血清中，与称为胰岛素样生长因子结合蛋白（IGFBP）的特异性结合蛋白家族的一个亚类结合。 内皮分泌的蛋白聚糖可能通过调节IGFBP结合来影响IGF-I活性。 该建议的假设是血管内皮细胞分泌硫酸乙酰肝素蛋白聚糖（P-HS），其可以置换并由此从血清结合蛋白（IGFBP-3）释放IGF-I。 这种释放将影响IGF-I与内皮细胞上的受体的结合，并因此影响IGF-I通过内皮细胞转运到下面的组织。 目前，尚不清楚P-HS是否会增强或抑制无障碍环境。 整个研究项目的具体目标是：1，确定在IGFBP存在或不存在的情况下，P-HS是否影响IGF-I与牛主动脉内皮细胞（BAE）的结合; 2，评估细胞密度和IGF-I添加如何影响BAE分泌P-HS; 3，测量P-HS对IGFBP-3、IGF-I和IGFBP-3/IGF-I复合物的影响（无细胞）;并开发和验证一个数学模型，纳入IGF-I/BAE系统的所有元素。 为了计划完整的研究方案，在研究计划期间将进行以下活动：1，从内皮条件培养基中获得并纯化P-HS; 2，证明添加P-HS对IGF-I与BAE结合的影响; 3，确定P-HS是否与IGF-I/IGFBP-3结合以及IGF-I是否可以从复合物中释放;和4，开发P-HS与复合物结合的定量结合测定，并确定该作用是否是蛋白聚糖特异性的。 ***

9629100 Forsten This is a Research Planning Grant for Women Scientists and Engineers. The overall objective of this research is to understand how the local cellular environment influences accessibility of growth factors to target stimulatory cells. IGF-I, an endocrine factor, is found almost exclusively in serum bound to a subset of a family of specific binding proteins known as the insulin-like growth factor binding proteins (IGFBP). Endothelial secreted proteoglycans may impact IGF-I activity through regulation of IGFBP binding. The hypothesis of this proposal is that vascular endothelial cells secrete heparan sulfate proteoglycans (P-HS) which can displace and thereby liberate IGF-I from serum binding proteins (IGFBP-3). This liberation will affect IGF-I binding to receptors on endothelial cells, and consequently transport of IGF-I by endothelial cells to the underlying tissue. Presently, it is not clear whether P-HS will potentiate or inhibit accessibility. The specific aims of the overall research project are to: 1, determine if P-HS influences IGF-I binding to bovine aortic endothelial cells (BAE) in the absence or presence of IGFBP; 2, evaluate how cell density and IGF-I addition impact P-HS secretion by BAE; 3, measure the effect of P-HS on IGFBP-3, IGF-I, and IGFBP-3/IGF-I complex (cell-free); and develop and validate a mathematical model incorporating all the elements of the IGF-I/BAE system. In order to plan for the full research proposal, the following activities will be done during the research planning period: 1, obtain and purify P-HS from endothelial conditioned medium; 2, demonstrate an effect of P-HS addition on IGF-I binding to BAE; 3, determine if P-HS binds to IGF-I/IGFBP-3 and if IGF-I can be liberated from the complex; and 4, develop a quantitative binding assay for P-HS binding to the complex and determine if the effect is proteoglycan specific. ***