The Urinary Proteome and Renal Function Loss in Diabetes

描述（由申请人提供）：近几十年来，糖尿病导致终末期肾病（ESRD）的风险增加了两倍。尽管广泛使用抗高血压药物和ACE抑制剂治疗，但仍发生了这种情况。ESRD的流行是由于发生肾功能丧失的糖尿病患者比例的实际增加，而不是这些患者生存率提高的结果。为了控制这种流行病，迫切需要研究工作来确定糖尿病肾功能丧失的决定因素和机制，以便制定新的预防方案。尤其缺乏的是关于早期肾功能衰退的开始和促进的知识。最近，我们发现大部分1型糖尿病患者一旦出现微量白蛋白尿（MA），肾功能开始下降。这种早期肾功能下降与尿白蛋白排泄水平的进一步增加无关，但与尿趋化因子水平升高有关。这些患者尿液的初步蛋白质组学分析显示，MA和早期肾功能下降患者尿液中存在特异性蛋白质，而MA和肾功能稳定患者尿液中不存在特异性蛋白质。这些未知的尿蛋白代表了暴露损伤MA患者近端小管的候选物，并且是导致尿趋化因子升高的原因。我们的目标是确定与早期肾功能下降最相关的蛋白质。此外，我们建议使用蛋白质组学分析方法来表征尿趋化因子，这些趋化因子可以区分早期肾功能下降风险的MA患者和肾功能稳定的MA患者。这些问题将在1型和2型糖尿病中进行检查。本提案的具体目的是：1)确定两组MA合并1型糖尿病（n=300）和2型糖尿病（n=500）患者早期肾功能显著下降的频率。2)采用基于质谱的蛋白质组学分析方法，比较早期肾功能下降患者和肾功能稳定对照组的尿蛋白谱，确定导致两组患者早期肾功能下降的尿蛋白。3)利用靶向蛋白质组学方法和Luminex技术，确定预测两组患者早期肾功能下降的尿液和血浆细胞因子/趋化因子谱。4)结合这些研究的所有发现，建立1型和2型糖尿病和MA患者早期肾功能下降的病因学模型。关于早期肾功能下降的机制和决定因素的研究是新颖的，将为开发预防糖尿病肾功能丧失的有效方法提供数据。

DESCRIPTION (provided by applicant): The risk of End Stage Renal Disease (ESRD) due to diabetes has tripled in recent decades. This has occurred despite widespread implementation of treatment with antihypertensive drugs and ACE inhibitors. This epidemic of ESRD is due to a real increase in the proportion of diabetic patients developing renal function loss rather than a consequence of improved survival of these patients. To contain this epidemic, research efforts are urgently needed to identify the determinants and mechanisms of renal function loss in diabetes so that new preventive programs can be developed. Particularly lacking is knowledge about the initiation and promotion of the early renal function decline. Recently, we found that renal function begins to decline in a large proportion of patients with type 1 diabetes once microalbuminuria (MA) develops. This early renal function decline was unrelated to further increases in the level of urinary albumin excretion but was associated with elevated levels of urinary chemokines. Preliminary proteomic analysis of urine from these patients revealed the presence of specific proteins in the urine of individuals with MA and early renal function decline that were absent in the urine of individuals with MA and stable renal function. These unknown urinary proteins represent candidates for exposures that injure the proximal tubules of patients with MA and are responsible for the elevated urinary chemokines. We aim to identify the proteins most associated with early renal function decline. Furthermore, we propose to use methods of proteomic analysis to characterize the urinary chemokines that distinguish patients with MA who are at risk of early renal function decline from those with stable renal function. These questions will be examined in both type 1 and type 2 diabetes. The Specific Aims of this proposal are: 1) To determine the frequency of significant early renal function decline in two cohorts of individuals with MA and type 1 diabetes (n=300), and type 2 diabetes (n=500). 2) To identify urinary protein(s) that cause early renal function decline in both cohorts by comparing urinary protein profiles between cases with early renal function decline and controls with stable renal function using proteomics analysis based on mass spectrometry. 3) To identify urinary and plasma cytokine/chemokine profiles that predict early renal function decline in the two cohorts using a targeted proteomics approach and Luminex technology. 4) To develop an etiologic model of early renal function decline in individuals with type 1 and type 2 diabetes and MA incorporating all the findings from these studies. The proposed research on the mechanisms and determinants of early renal function decline is novel and will provide data for the development of effective methods of prevention of renal function loss in diabetes.