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.

项目概要：肾病综合征（NS）以蛋白尿为特征，与足细胞相关肌动蛋白细胞骨架紊乱，称为足突消失（FPE），足细胞无法自我修复。每个肾小球更新和足细胞损失超过 40% 与肾小球硬化 (FSGS) 和肾脏相关与 FSGS 不同，微小病变 (MCD) 也表现出弥漫性 FPE，但保留了。足细胞数量，并且对治疗高度敏感，进展为 ESRD 的比率较低（20 例中为 5-20%） FSGS 与晚期肾小球肿大和足细胞肥大有关。早期 FSGS 在形态学上与 MCD 无法区分，并且对于某些 MCD 病例是否存在争议向 FSGS 的过渡，代表疾病之间的“转换”，因此，了解 MCD 特有的信号。将揭示促进足细胞存活和防止表型“转换”的机制。在人类 MCD 中特别发现了激酶失活，而在小鼠中，Fyn 失活（通过 Shroom3 沉默）。也与不伴有足细胞减少症的 FPE 相关 - 一种“MCD 样”病理学，因此 Fyn 失活是一种。 Fyn 失活下游的候选 MCD 独特信号，抗肥大和亲的研究。足细胞的存活途径揭示了 AMP 激酶的激活增强，解释了 Fyn 的这些效应。失活通过增加 LKB1 的细胞质流出来激活 AMPK，此外，在 MCD 样中抑制 Ampk。小鼠诱导足细胞丢失、肾小球肿大和 FSGS，而 AMPK 激活可防止足细胞丢失肥大和直接毒素诱导的肾小球损伤以自噬增加为中心。 AMPK 激活后足细胞的促生存机制我们在造成损伤的背景下取消了这一机制。足细胞 FPE、AMPK 信号通过增强自噬和调节 MCD 和 FSGS 之间的“转换” 在本提案中，我们将测试足细胞 AMPK 信号传导在 MCD 与 FSGS 中的作用，并建立调节足细胞存活的下游机制。在目标 I 中，我们将利用遗传和机制。药理学模型系统特异性失活或激活 AMPK 以诱导表型变化 MCD 至 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核心作用。最后，在 Aim-III 中，应用最先进的技术和技术，研究自噬在限制损伤期间肾小球肿大中的作用。通过多维技术对美国最大的 NS 队列进行研究，我们将研究 AMPK 的具体作用我们的工作将提供新的 MCD-FSGS 诊断方法，并开发新的方法。 AMPK 疗法还有助于重新利用 FDA 批准的 AMP 激活剂。