The Role of Bone Morphogenetic Protein-7 in Renal Endothelial Cell Biology

描述（由申请人提供）：据估计，到2010年，终末期肾病（ESRD）的年增长将超过170，000例，患病率超过660，000例患者。据进一步估计，每年治疗终末期肾病患者的费用将超过卡特里娜飓风前的390亿美元。大多数情况下，肾脏结节的显微镜外观变化与导致ESRD的肾功能下降相关。对肾小管周围毛细血管内皮细胞的研究很少。骨形态发生蛋白-7（BMP-7）具有肾脏保护和肾脏再生的特性，可减缓ESRD的进展。正在测试的一般假设是，BMP-7的肾保护和肾恢复作用的一部分是由于这种生长因子是内皮保护和内皮恢复。据推测，BMP-7直接影响肾内皮细胞，并促进肾的三维细胞外基质中的血管生成。{By开发策略以保存/恢复肾管周毛细血管;该项目可有助于延长肾功能，从而最小化与治疗ESRD相关的成本}。本提案的具体目的是：1）确定外源性BMP-7对体外内皮细胞生物学的影响; 2）确定外源性BMP-7对体内肾内皮细胞生物学的影响。这些实验将在2维和3维细胞培养物中使用永生化小鼠内皮细胞系，并使用胶原1和胶原IV基质。将用BMP-7和/或转化生长因子-β（TGF-β）处理或不处理培养物中的细胞，并评估其迁移、增殖、凋亡和毛细管形成。将确定各种蛋白激酶途径的贡献和激酶对这些过程的阻断。体内研究将利用可重复的肾纤维化动物模型，即急性和慢性单侧输尿管梗阻（UUO）小鼠。{The在UUO模型中与管周毛细血管完整性相关的发现将在发展为高血糖症的肥胖小鼠模型中进一步测试。肥胖模型将对慢性肾病具有更广泛的意义，而急性UUO模型将鉴定BMP-7是内皮保护性的机制。将采用双标记免疫细胞化学来鉴定肾内皮细胞以及BMP-7处理沿着TGF-β调节对内皮细胞内和附近的蛋白激酶活性的影响。将整合体外和体内研究，以最大限度地发挥BMP-7治疗的作用，保护肾内皮细胞，进而保护肾上皮细胞，最终保护肾功能。如果患有肾脏疾病的医疗保险患者没有进行透析，估计每位患者可以节省医疗保险250.000美元。该提案审查了一种旨在延缓或阻止肾脏疾病进展的治疗方法，从而节省了年度医疗保险预算的很大一部分。

DESCRIPTION (provided by applicant): It is estimated that by 2010, the annual increase in end-stage renal disease (ESRD) will exceed 170,000 cases with a prevalence of over 660,000 patients. It is further estimated that the yearly cost of treating patients with ESRD will be over 39 billion in pre-Katrina dollars. By most accounts, changes in the microscopic appearances in the interstitium of the kidney correlate with the decline of renal function leading to ESRD. A part of the renal interstitium that has been minimally investigated are the endothelial cells of the peritubular capillaries. Bone Morphogenetic Protein-7 (BMP-7) has renoprotective and renoregenarative properties blunting progression of ESRD. The general hypothesis being tested is that part of the renoprotective and renorestorative effects of BMP-7 are due to this growth factor being endothelial-protective and endothelial restorative. It is postulated that BMP-7 directly effects renal endothelial cells and promotes angiogenesis in the 3-dimensional extracellular matrix of the kidneys. {By developing strategies to preserve/restore renal peritubular capillaries; this project may contribute to prolonging renal function thereby minimizing the costs associated with treating ESRD}. The specific aims of this proposal are to; 1) Determine the effects of exogenous BMP-7 on endothelial cell biology in vitro; and 2) Determine the effects of exogenous BMP-7 on renal endothelial cell biology in vivo. These experiments will utilize an immortalized mouse endothelial cell line in both 2-dimentional and 3- dimensional cell culture with collagen 1 and collagen IV matrices. The cells in culture will be treated or not with BMP-7 and/or transforming growth factor-beta (TGF-¿) and assessed for migration, proliferation, apoptosis and capillary tube formation. The contribution of various protein kinase pathways and blockade of the kinases on these processes will be determined. The in vivo studies will utilize a reproducible animal model of renal fibrosis the mouse with acute and chronic unilateral ureteral obstruction (UUO). {The findings relevant to peritubular capillary integrity in the UUO model will be further tested in an obese mouse model that develops hyperglycemia. The obese model will have broader implications to chronic kidney disease while the acute UUO model will identify mechanisms by which BMP-7 is endothelial protective}. Dual-label immunocytochemistry will be employed to identify renal endothelial cells and the impact of BMP-7 treatment along with TGF-¿ modulation on protein kinase activities within and adjacent to the endothelial cells. The in vitro and in vivo studies will be integrated to maximize the effects of BMP-7 treatment that preserve renal endothelial cells and in turn, renal epithelial cells and ultimately renal function. If a Medicare patient with kidney disease does not progress to dialysis the estimated savings to Medicare is $250.000 for each patient. This proposal examines a treatment designed to delay or halt the progression of renal disease thereby saving a significant portion of the yearly Medicare budget.