Role of Muc1 in the b-catenin Response to Acute Kidney Injury

项目摘要/摘要 Al-Bataineh博士在获奖期间的职业目标是开发一个研究项目和专业人员 使他能够在科学上独立于他的导师，并建立自己的专业知识 急性肾损伤独立转化性研究的职业道路。巴塔内博士将进一步推进他的 通过提高他对(I)验证的肾损伤动物模型的熟练程度来进行实验室研究和培训 包括双肾悬吊体重小鼠缺血再灌注损伤模型和小鼠模型 AKI-CKD进展的进展，(Ii)包括多光子显微镜在内的肾脏显微镜的先进方法， 三维成像和定量显微分析，以及(Iii)分子方面的技术专长 ChIPseq和启动子-荧光素酶报告分析等生物技术。Al-Bataineh博士计划 在他的指导研究培训的2-3年内过渡到独立的终身教职轨道职位 这个奖项。他的长期职业目标是在广阔的领域成为一名完全独立的学术研究者。 肾脏生理和肾脏疾病的研究，提供对基础知识的洞察 影响临床问题的生理问题，特别关注AKI的病理、预防和 治疗。-连环蛋白信号是一种复杂的细胞反应，在肾脏过程中在肾小管中被激活。 受伤。而中度缺血导致与肾脏相关的一过性-连环蛋白水平的诱导 保护，严重缺血导致-连环蛋白通路持续激活和肾脏发育 纤维化，意味着损伤的严重程度是长期结果的关键决定因素。新出现的证据支持 跨膜糖蛋白粘蛋白1(人为粘蛋白1，动物为粘蛋白1)对-连环蛋白的调节作用 活动。在肿瘤细胞中，(I)MUc1与胞浆和胞核中的-catenin直接结合，(Ii)MUc1阻断 糖原合成酶激酶3()介导的-连环蛋白的降解，以及(Iii)MUC1超表达 与核-连环蛋白水平及其转录活性增加相关。我们之前报道过， 在正常肾上皮细胞的顶端表面发现的MUC1在小鼠模型中起到保护作用。 比较MUC1KO小鼠和同种异体小鼠肾脏功能和形态的缺血再灌注损伤 对照小鼠(AJP-Renal，2015年；PMID：25925251)。我们最近的研究表明，MUC1诱导和 中度缺血后靶向细胞核与-连环蛋白水平和信号的增加有关 (AJP--2016年肾脏；PMID：26739894)。我们还观察到，MUC1的持续上调也是 与严重缺血后7d小鼠肾组织匀浆中-连环蛋白的诱导时间延长有关。 基于这些发现和以前关于-连环蛋白在以下方面的急性和慢性影响的报道 肾损伤，我们假设MUC1通过反式激活-1来保护急性肾损伤的早期。 连环蛋白途径，但持续的MUC1/-连环蛋白信号转导导致慢性肾脏病的进展和肾脏 纤维化症。我们建议的研究将使用中度和重度IRI的小鼠模型和培养的 人肾细胞系(HEK-293)在ATP耗竭后建立的缺血性细胞损伤模型。 此外，我们已经获得了不同水平的MUC1表达的小鼠(MUC1基因敲除， 杂合子和过量表达人类MUC1的转基因)将被用来评估是否增加了水平 MUC1在肾脏中的短期表达增强了对IRI的保护，同时延长了MUC1的表达 促进肾脏纤维化。成功完成拟议的研究将为我们深入了解 在IRI和修复期间改变的信号通路，将提供有价值的信息来帮助我们 设计新的治疗策略来治疗AKI和防止CKD进展。

Project summary/abstract Dr. Al-bataineh’s career goals for the award period are to develop a research project and professional expertise that will enable him to develop scientific independence from his mentor and to establish his own career path to independent translational research in acute kidney injury. Dr. Al-bataineh will further his laboratory research and training by developing his proficiency in (i) validated animal models of renal injury including the two-kidney hanging-weight mouse model of ischemia-reperfusion injury (IRI), and mouse model of AKI-CKD progression, (ii) advanced approaches of kidney microscopy including multiphoton microscopy, three-dimensional imaging, and quantitative microscopic analyses, and (iii) technical expertise in molecular biology techniques such as ChIPseq and promoter-luciferase reporter assays. Dr. Al-bataineh plans to make the transition to an independent, tenure track position within 2-3 years of his mentored research training during this award. His long-term career goal is to become a fully independent academic investigator in the broad fields of renal physiology and kidney disease, performing research that provides insight into fundamental physiological problems that impact clinical issues, with a particular focus on AKI pathology, prevention, and treatment. -catenin signaling is a complex cellular response that is activated in renal tubules during kidney injury. While moderate ischemia results in transient induction of -catenin levels that associated with kidney protection, severe ischemia leads to sustained activation of the -catenin pathway and development of kidney fibrosis, implicating severity of injury as a key determinant of long term outcome. Emerging evidence supports a role for the transmembrane glycoprotein mucin 1 (MUC1 in humans, Muc1 in animals) in regulating -catenin activity. In tumor cells, (i) MUC1 directly binds to -catenin in the cytoplasm and nucleus, (ii) MUC1 blocks glycogen synthase kinase 3 (GSK3)-mediated degradation of -catenin, and (iii) MUC1 overexpression correlates with increased levels of nuclear -catenin and its transcriptional activity. We previously reported that Muc1, found on the apical surface of normal kidney epithelia, plays a protective role in a mouse model of ischemia-reperfusion injury (IRI) by comparing kidney function and morphology in Muc1 KO mice and congenic control mice (AJP-Renal 2015; PMID: 25925251). Our recent studies showed that Muc1 induction and targeting to the nucleus after moderate ischemia was associated with increased -catenin levels and signaling (AJP-Renal 2016; PMID: 26739894). We also observed that sustained upregulation of Muc1 was also associated with prolonged induction of -catenin in mouse kidney homogenates at 7 d after severe ischemia. Based on these findings and on previous reports related to the acute and chronic effects of -catenin after kidney injury, we hypothesize that Muc1 protects against the early stages of AKI via transactivation of - catenin pathway, but persistent Muc1/-catenin signaling after severe AKI leads to CKD progression and renal fibrosis. Our proposed studies will utilize both a mouse model of moderate and severe IRI, and a cultured human kidney cell line (HEK-293) after ATP depletion as an established model of ischemic cell injury. Moreover, we have already obtained mice with varying levels of Muc1 expression (Muc1 knockout, heterozygotes, and a transgenic overexpressing human MUC1) that will be used to assess if increased levels of Muc1 in the kidney in the short term enhance protection during IRI, while prolonged expression of Muc1 promotes kidney fibrosis. Successful completion of the proposed studies will provide important insight into the signaling pathways that are altered during IRI and repair, and will provide valuable information to help us design novel therapeutic strategies to treat AKI and prevent CKD progression.