AMP Kinase Activation in Calcineurin Inhibitor Nephrotoxicity

实体器官移植需要终生免疫抑制。尤其是钙调神经磷酸酶 几乎所有的移植受者都使用抑制剂(CNI)，因为它们是有效的免疫抑制剂。在……里面 在肾移植中，CNIs的使用导致了非常低的排斥率，每年约为7-10%。然而， 移植物的长期存活并没有随着它们的使用而有实质性的改善，平均半衰期为10年 肾移植。晚期移植物损伤的一个关键因素是CNI-肾毒性，表现为肾功能下降 肾功能和间质纤维化、肾小管萎缩、小动脉透明质形成的组织学特征。这个 CNI导致肾损伤和肾功能衰竭的机制是多因素的，到目前为止，还没有明确的机制。 减轻这种伤害的治疗策略。这份意见书的目标是确定一种新颖的和临床上的 减轻CNI相关性肾损伤的适用策略。最近，AMP激活的蛋白激酶 AMPK是细胞新陈代谢、自噬和线粒体生物发生的关键调节因子，已被认为与 调节肾脏损伤。此外，AMPK活性的丧失与器官炎症和纤维化有关。 我们假设激活AMPK可以改善肾脏中的一些不良代谢后果。 作为一个推论，AMPK的激活可能是一种临床相关的干预措施，以减轻 CNI的长期肾毒性。我们的研究将集中在环孢素A(CsA)，一种经典的CNI治疗药物。 我们将利用体外和体内的一系列补充研究，使用CsA损伤的小鼠模型。 我们已经在我们的实验室成功地使用了它。在体外，我们将重点研究肾小管上皮细胞，原代 活体损伤的目标。我们将研究AMPK激活的影响以及使用 药理制剂和沉默的RNA。结果将包括对生物能量学、线粒体 功能、促炎标志物和湿HMGB1、旁分泌对巨噬细胞及其功能的影响 差异化。在体内，我们将通过评估来测试AMPK激活对改善CsA肾损伤的影响 肾功能(血肌酐)，肾脏内炎症介质的mRNA表达，以及 损伤和纤维化的生化、细胞和组织学评估。我们将评估这两个先发制人的 抑制以及确定AMPK激活对CsA肾毒性建立后的影响。至 作为这些药理研究的补充，我们还将利用AMPK1和2缺陷的新用途 老鼠。交叉移植研究将使我们能够剖析AMPK在全身和肾脏中表达的作用 受伤。我们相信，这种全面的方法将提供关键的机械见解，以改善或 减轻CNI肾毒性。临床相关激活剂二甲双胍的使用将提供一个机会 用于快速移植到我们的肾脏和其他固体器官移植的人类接受者体内。

Solid organ transplantation necessitates the use of lifelong immunosuppression. In particular, the calcineurin inhibitors (CNIs) are utilized in nearly all transplant recipients as they are potent immunosuppressants. In kidney transplantation, the use of CNIs has led to the very low rejection rates of ~7-10% per year. However, long term graft survival has not improved substantially with their utilization, with a mean half-life of 10 years for kidney transplants. A key contributor to late graft injury is CNI-nephrotoxicity which is manifested by declining kidney function and the histological features of interstitial fibrosis, tubular atrophy, and arteriolar hyalinosis. The mechanism by which CNI induce kidney injury and failure is multifactorial, and to date, there are no specific therapeutic strategies to mitigate this injury. The goal of this submission is to identify a novel and clinically applicable strategy to ameliorate CNI-associated kidney injury. Recently, AMP-Activated Protein Kinase (AMPK), a key regulator of cell metabolism, autophagy, and mitochondrial biogenesis, has been linked to modulating kidney injury. Further, loss of AMPK activation is associated with organ inflammation and fibrosis. We hypothesize that AMPK activation could ameliorate some of the adverse metabolic consequences in renal tubular epithelium and as a corollary, AMPK activation could be a clinically relevant intervention to mitigate long term CNI nephrotoxicity. Our study will focus on cyclosporine A (CsA), a classic CNI therapeutic agent. We will utilize a complementary series of studies, both in vitro and in vivo, using a mouse model of CsA injury that we have used successfully in our laboratory. In vitro, we will focus on renal tubular epithelium, the primary target of in vivo injury. We will study both the impact of AMPK activation as well as knock down using pharmacologic agents and silencing RNAs. Outcomes will include assessments of bioenergetics, mitochondrial function, pro-inflammatory markers and the DAMP HMGB1, and paracrine impact on macrophages and their differentiation. In vivo, we will test the impact of AMPK activation on ameliorating CsA renal injury by assessing kidney function (serum creatinine), mRNA expression of inflammatory mediators within the kidney, and biochemical, cellular and histologic assessments of injury and fibrosis. We will assess both pre-emptive inhibition as well as determine the impact of AMPK activation after established CsA nephrotoxicity. To complement these pharmacologic studies, we will also employ the novel use of AMPK 1 and 2 deficient mice. Cross-transplant studies will allow us to dissect the role of systemic versus renal expression of AMPK in injury. We believe that this comprehensive approach will provide key mechanistic insights into ameliorating or mitigating CNI nephrotoxicity. The use of a clinically relevant activator, metformin, will provide an opportunity for rapid translation into our human recipients of kidneys and other solid organ transplants.