Glucose Modifications of Proteins in Diabetic Nephropathy

描述（由申请人提供）：目前有超过2.85亿人受到影响，预计到2030年将有4.85亿人受到影响，糖尿病已成为全球流行病。与这一流行病相关的医疗保健费用令人震惊，2010年全球成本为3760亿美元，预计到2030年将超过4900亿美元。30-40%的糖尿病患者患有肾病，终末期肾病（ESRD）是一个非常值得关注的问题，因为需要透析或肾移植来维持患者的生命。迫切需要开发新的治疗方法来预防或延缓糖尿病性终末期肾病的进展。非酶氧化途径的激活，形成修饰肾细胞外基质（ECM）长寿命胶原的AGEs（晚期糖基化终产物），被广泛认为是糖尿病肾病（DN）的关键致病机制。吡哆沙胺（Pyridoxamine, PyridorinTM）是我们在过去二十年中开发的一种研究候选药物，在体外条件下抑制这些途径。重要的是，在两项2期临床试验中，Pyridorin （PM）显示出延缓DN进展的希望，目前正在接受FDA的3期临床试验审查。在目前的建议中，我们试图进行体内实验，以确定DN进展中的详细致病途径，并确定那些对PM治疗有反应的途径。具体而言，我们将1)确定伴随或先于DN发展的肾细胞外基质（ECM）、系膜基质和肾小球基底膜的翻译后修饰和分子组成的变化；2)确定肾脏ECM的氧化修饰，赋予DN致病性细胞-基质相互作用；3)探索尿代谢组学以确定致病途径和对治疗有反应的途径。对于这些体内研究，我们将使用eNOS-/- C57BLKS db/db小鼠模型，这是迄今为止最强大的DN模型，最接近人类DN。此外，我们将利用常规和成像质谱和核磁共振波谱技术表征与DN进展相关的分子变化以及对PM治疗的反应，这些研究技术可以提供有关肾脏组织分子结构的精确信息。预计这些发现将产生与人类DN和PM治疗相关的致病途径的新信息，并将为开发新的候选药物建立一个平台，这些候选药物可以补充PM治疗并可能协同作用以减缓DN的进展。

DESCRIPTION (provided by applicant): With more than 285 million people currently affected, and an estimated 485 million by 2030, diabetes has become a worldwide pandemic. The healthcare costs associated with this pandemic are staggering with a worldwide cost of $376 billion in 2010 projected to exceed $490 billion by 2030. With 30-40% of diabetics being affected by nephropathy, end stage renal disease (ESRD) is of great concern given the requirement for dialysis or kidney transplantation to sustain the patient's life. There is a pressing need to develop novel therapeutics for preventing or delaying the progression to diabetic ESRD. Activation of non-enzymatic oxidative pathways, forming AGEs (advanced glycation end products) that modify the long-lived collagens of the renal extracellular matrices (ECM), is widely held as a key pathogenic mechanism that underlies diabetic nephropathy (DN). Pyridoxamine (PyridorinTM), an investigational drug candidate, which we have developed over the past two decades, inhibits these pathways under in vitro conditions. Importantly, in two phase 2 clinical trials, Pyridorin (PM) has shown promise in delaying the progression to DN, and it is currently under review by FDA for a phase 3 clinical trial. In the present proposal, we seek to conduct in vivo experimentation to identity detailed pathogenic pathways in the progression of DN and to identify those responsive to PM therapy. Specifically, we will 1) determine changes in the post- translational modifications and molecular composition of renal extracellular matrices (ECM), mesangial matrix and glomerular basement membrane, that accompany or precede development of DN; 2) identify oxidative modifications of renal ECM that confer pathogenic cell-matrix interactions in DN; and 3) explore the urinary metabolome to identify pathogenic pathways and those responsive to therapy. For these in vivo investigations, we will utilize the eNOS-/- C57BLKS db/db mouse model, the most robust DN model to date, which most closely approximates human DN. Furthermore, we will characterize the molecular changes associated with the progression to DN and those responsive to PM therapy using conventional and imaging mass spectrometry and nuclear magnetic resonance spectroscopy, research technologies that can provide precise information about molecular structure of renal tissues. It is anticipated that the findings will yield novel information about pathogenic pathways relevant to DN and PM therapy in humans, and will establish a platform for the development of new drug candidates that are complementary to PM therapy and potentially act synergistically to slow DN progression. PUBLIC HEALTH RELEVANCE: Diabetes will affect an estimated 485 million by 2030, with 30-40% of diabetics developing nephropathy (DN) and end stage renal disease. It is anticipated that the proposed research will yield novel information about pathogenic pathways causing DN and establish a platform for the development of new drug candidates to slow DN progression.