Role of AMP-kinase pathway in the regulation of Minimal change disease-to-FSGS transition

AMP-激酶途径在微小病变向 FSGS 转变调节中的作用

基本信息

批准号：
10585051
负责人：
Madhav C Menon
金额：
$ 55.56万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-12-15 至 2027-11-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10585051
关键词：
1 year old Actins Adriamycin PFS Albuminuria Autophagocytosis Biological Models Biopsy Case Series Case Study Cell Survival Cytoplasm Cytoskeleton Data Diagnostic Diagnostic Procedure Diffuse Dimensions Disease End stage renal failure Event FDA approved FYN gene Focal and Segmental Glomerulosclerosis Foot Process Genetic Genetic Models Growth Human Hypertrophy In Vitro Injury Investigation Kidney Failure Mediating Modeling Morphology Multiple Trauma Mus Nephrectomy Nephrotic Syndrome Pathology Pathway interactions Phenotype Phosphotransferases Proteinuria Proteomics Proto-Oncogene Proteins c-fyn Regulation Role STK11 gene Signal Transduction Stress Technology Testing Therapeutic Toxin Visualization Work adenylate kinase aged biobank cohort design glomerulosclerosis in vitro Model in vivo inhibition of autophagy injured innovation knock-down morphometry novel novel therapeutics overexpression pharmacologic podocyte preservation prevent prognostic value protective effect response self-renewal transcriptomics

项目摘要

Project Summary: Nephrotic syndrome (NS) is characterized by proteinuria and is associated with podocyte actin cytoskeletal disorganization termed foot process effacement (FPE). Podocytes are incapable of self- renewal, and podocyte loss above~40% per glomerulus associates with glomerulosclerosis (FSGS) and kidney failure. Distinct from FSGS, Minimal Change Disease (MCD) also shows diffuse FPE, but has preserved podocyte numbers, and is highly treatment responsive with a low rate of progression to ESRD (5-20% in 20 years). FSGS has been associated with glomerulomegaly and podocyte hypertrophy in later stages. However, early FSGS can be morphologically indistinguishable from MCD and a debate exists whether some MCD cases transition to FSGS, representing a “switch” between diseases. Hence, understanding signals specific to MCD will reveal mechanisms facilitating podocyte survival and preventing a phenotype “switch”. Interestingly, Fyn kinase inactivation was specifically identified in human MCD. In mice, Fyn inactivation (by Shroom3 silencing) also associated with FPE without podocytopenia - an “MCD-like” pathology. Hence Fyn inactivation was a candidate MCD-unique signal. Downstream of Fyn-inactivation, investigation of anti-hypertrophy and pro- survival pathways in podocytes revealed enhanced activation of AMP-kinase, explaining these effects. Fyn inactivation activated AMPK by increasing cytoplasmic efflux of LKB1. Moreover, inhibition of Ampk in MCD-like mice induced podocyte loss, glomerulomegaly and FSGS, while AMPK activation prevented podocyte loss after glomerular injury induced by hypertrophy and direct toxins. Invitro data show increased autophagy as the central pro-survival mechanism in podocytes after AMPK-activation. We hypothesize that in the context of injury causing podocyte FPE, AMPK signaling regulates the “switch” between MCD and FSGS by enhancing autophagy and preventing podocytopenia. In this proposal, we will test the role of podocyte AMPK signaling in MCD vs FSGS, and establish downstream mechanisms regulating podocyte survival. In Aim I, we will use genetic and pharmacologic model systems to specifically inactivate or activate AMPK to induce phenotype changes from MCD-to-FSGS and vice versa. In Aim-II, we will modulate autophagy in podocytes while activating AMPK to show the central role of AMPK-mediated autophagy in podocyte survival. We will also specifically examine the role of autophagy in restricting glomerulomegaly during injury. Finally, in Aim-III, applying state-of-the-art and multidimensional technologies to the largest NS cohort in the US, we will investigate the specific role of AMPK signaling in human MCD vs FSGS. Our work will provide novel MCD-FSGS diagnostics, and develop novel AMPK therapeutics as well as help repurpose FDA-approved AMP-activators.

项目摘要：肾病综合征（NS）的特征是蛋白尿，与足细胞有关肌动蛋白细胞骨架混乱称为脚步过程（FPE）。足细胞无能力每个肾小球与肾小球硬化（FSGS）和肾脏相关的更新和足细胞损失高于约40％失败。与FSG不同，最小变化疾病（MCD）也显示出弥漫性FPE，但保留了足细胞数，并且对ESRD的进展率较低，高度治疗能力（20％）年）。 FSG在后期阶段与肾小球肿瘤和足细胞肥大有关。然而，早期的FSG在形态上与MCD无法区分，并且是否存在一些MCD案例过渡到FSG，代表疾病之间的“开关”。因此，理解特定于MCD的信号将揭示支持足细胞存活并防止表型“开关”的机制。有趣的是，Fyn 激酶失活在人MCD中是特异性鉴定的。在小鼠中，Fyn失活（通过shroom3沉默）也与没有足型细胞减少症的FPE有关 - 一种“ MCD样”病理学。因此，fyn失活是候选MCD唯一信号。 Fyn灭活的下游，抗肌营养和促进的研究足细胞中的生存途径显示AMP激酶的激活增强，从而解释了这些作用。 Fyn 通过增加LKB1的细胞质外排来激活AMPK。此外，抑制类似MCD的AMPK 小鼠诱导足细胞损失，肾小球肿大和FSG，而AMPK激活阻止了足细胞损失。肥大和直接毒素引起的肾小球损伤。 Invitro数据显示自动噬在中央 AMPK激活后足细胞中的生存机制。我们假设在造成伤害的情况下 Podocyte FPE，AMPK信号传导通过增强自噬和预防足细胞减少症。在此提案中，我们将测试Podocyte AMPK信号在MCD与FSG中的作用，并建立恢复足细胞存活的下游机制。在目标I中，我们将使用遗传和药理学模型系统专门灭活或激活AMPK以诱导表型从 MCD-to-fsgs，反之亦然。在AIM-II中，我们将在激活AMPK的同时调节足细胞的自噬显示AMPK介导的自噬在足细胞存活中的中心作用。我们还将专门检查自噬在受伤期间限制肾小球肿瘤中的作用。最后，在AIM-III中，应用最先进的多维技术到美国最大的NS队列，我们将研究AMPK的具体作用人类MCD与FSG中的信号传导。我们的工作将提供新颖的MCD-FSGS诊断，并开发新颖 AMPK疗法以及帮助改革FDA批准的AMP激活剂。