Mechanisms of ER-Protein Quality Control in Podocytes

足细胞内质网蛋白质量控制机制

基本信息

批准号：
10579572
负责人：
Ling Qi
金额：
$ 39.96万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-01-01 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10579572
关键词：
Adult Affect Age Autophagocytosis Autophagosome Biogenesis Biology Cell Count Cell Death Cell Survival Cell physiology Child Complex Data Defect Degradation Pathway Disease Electrons Endoplasmic Reticulum Ensure Female Filtration Foot Process Growth Health Homeostasis Human Impairment In Vitro Integral Membrane Protein Investments Laboratories Link Longevity Mediating Microscopic Modeling Molecular Mus Nephrotic Syndrome Pathogenesis Pathologic Physiological Physiology Play Proteins Proteinuria Proteomics Quality Control Role Structure System Testing Therapeutic Work Yeasts autosome clinically relevant gain of function in vivo insight interest loss of function male misfolded protein mouse model mutant nephrin podocyte premature prevent protein aggregation protein complex protein degradation protein folding response slit diaphragm synergism

项目摘要

Mechanisms of ER Protein Quality Control in Podocytes SUMMARY My laboratory has a long-standing interest in protein folding and degradation within the endoplasmic reticulum (ER) by defining the physiological and pathological importance of mammalian ER quality-control machineries in vivo. ER-associated degradation (ERAD) is the principal protein quality-control mechanism responsible for targeting misfolded proteins in the ER for cytosolic proteasomal degradation. The SEL1L-HRD1 protein complex represents the most conserved branch of ERAD. We recently showed that mice with Sel1L deficiency in podocytes develop proteinuria at ~5 weeks of age and die prematurely with a median life span of ~14 weeks for both males and females (Yoshida et al. 2021 J CIin Invest). Electron microscopic analyses revealed foot process effacement and impaired slit diaphragm in the absence of Sel1L. Mechanistically, we showed that SEL1L-HRD1 ERAD in podocytes plays a critical role in the maturation of nascent nephrin in the ER, without affecting podocyte cell number and survival. In our recent work, our preliminary data suggested a possible crosstalk, or likely synergism, between ERAD and another key degradative pathway autophagy in podocytes. We propose to test the overarching hypothesis that the SEL1L-HRD1 ERAD protein complex plays a critical role in podocytes by coordinating the activation of autophagy, which ensures cellular homeostasis and filtration function. This model challenges/expands the current paradigm in ER biology by placing SEL1L-HRD1 ERAD at the center of cellular function in normal physiology and disease pathogenesis. Using various mouse models, we will accomplish the following Aims: (1) Demonstrate the pathophysiological importance of the crosstalk between SEL1L-HRD1 ERAD and autophagy in podocytes; (2) Determine how SEL1L-HRD1 ERAD controls autophagy activity in podocytes; and (3) Delineate the pathological importance and mechanism of ERAD and autophagy in the pathogenesis of nephrin disease mutants involved in nephrotic syndrome. This study will provide unprecedented insights into the crosstalk among key ER quality control machineries in podocytes, and shed new light on the therapeutic potential of targeting ER homeostasis in podocytes. RELEVANCE TO HUMAN HEALTH: Defects in podocytes and in the formation slit diaphragm, a specialized structure involving many transmembrane proteins, underlie nephrotic syndrome, affecting children and adults of all ages. While the ER quality control systems are presumably integrated to maintain ER homeostasis, the crosstalk between quality-control systems has not yet been investigated in vivo. This study will establish the pathophysiological significance of ERAD and the crosstalk between ERAD and autophagy in podocytes in health and diseases.

ER蛋白质质量控制的机理概括我的实验室对内质网中的蛋白质折叠和降解具有长期的兴趣（er）通过定义哺乳动物ER质量控制机械机器的生理和病理学重要性体内。 ER相关降解（ERAD）是负责的主要蛋白质质量控制机制靶向ER中的错误折叠蛋白以进行胞质蛋白酶体降解。 SEL1L-HRD1蛋白复合物代表Erad最保守的分支。我们最近表明，SEL1L缺乏的小鼠足细胞在〜5周龄时发育蛋白尿，并过早死亡，中位寿命约为14周男性和女性都（Yoshida等，2021 J Ciin Invest）。电子显微镜分析揭示了脚步过程在没有SEL1L的情况下，ex骨和狭缝受损。从机械上讲，我们证明了SEL1L-HRD1 足细胞中的ERAD在ER中新生肾素的成熟中起关键作用，而不会影响足细胞细胞数和生存。在我们最近的工作中，我们的初步数据提出了可能的串扰，或者可能在Erad和Podocytes中自噬的另一个关键降解途径之间的协同作用。我们建议测试 SEL1L-HRD1 ERAD蛋白复合物在足细胞中起关键作用的总体假设协调自噬的激活，从而确保细胞稳态和过滤功能。这个模型通过将SEL1L-HRD1 ERAD放置在细胞中心，挑战/扩展了ER生物学的当前范式正常生理和疾病发病机理的功能。使用各种鼠标模型，我们将完成以下目的：（1）证明了SEL1L-HRD1之间串扰的病理生理重要性足细胞中的ERAD和自噬；（2）确定SEL1L-HRD1如何控制自噬活动足细胞；（3）描述了伊拉德和自噬的病理重要性和机制参与肾病综合征的肾素疾病突变体的发病机理。这项研究将提供前所未有的在podocytes中洞悉关键ER质量控制机器之间的串扰，并在靶向足细胞中ER稳态的治疗潜力。与人类健康的相关性：足细胞的缺陷和形成狭缝隔膜（一种专业）涉及许多跨膜蛋白的结构，肾病综合征基础，影响儿童和成年所有年龄段。尽管ER质量控制系统大概是整合以维持ER的稳态，但质量控制系统之间的串扰尚未在体内进行研究。这项研究将确定 ERAD的病理生理意义以及健康状态的ERAD和自噬之间的串扰和疾病。