The Effect of Sodium (Na+) on Kidney B cells in Lupus Nephritis

项目摘要 狼疮性肾炎是自身免疫性疾病系统性红斑狼疮(SLE， 狼疮)；10%的患者进展为终末期肾脏疾病。狼疮性肾炎肾脏的特点 受深度淋巴细胞的浸润性和浸润性程度的影响，特别是B淋巴细胞 与组织损伤和疾病严重程度有关。肾脏的轴向浓度梯度也是其特征。 钠(Na+)，比血清高2倍。因此，危险的肾脏环境呈现出独特的存活率。 可能塑造其表型和功能的浸润性淋巴细胞面临的挑战。肾内B蛋白的功能 细胞和它们用来适应恶劣的肾脏环境的途径仍未确定。 我的初步数据显示，狼疮易感小鼠的B细胞在暴露于 与野生型小鼠相比，体外高Na+。这种作用是由钠的高表达所介导的。 K+-K+-ATPase(Na+-K+-ATPase，NKA)是细胞离子平衡的关键调节因子。我也已经证明了 狼疮小鼠肾脏浸润性B细胞对[Na+]升高的适应及体内NKA的表达 与浸润性B细胞在肾脏中持续存在的能力相关。NKA和NKA的药理抑制作用 基因敲除NKA g亚基，后者以前不知道在B细胞中表达，导致 减少肾脏B细胞浸润，改善蛋白尿。SLE患者肾活检组织中的B细胞 比肾内T细胞表达更多的NKA，提示同样的NKA调节的B细胞生存途径是 手术治疗人类系统性红斑狼疮肾炎。Na+如何影响细胞死亡途径以及它是否调节B细胞功能， 例如抗体或细胞因子的产生是未知的。我假设Na+调节肾内B细胞死亡 对其通路和功能的研究有助于加深对狼疮性肾炎发病机制的认识。在AIM 1，我将研究狼疮与健康对照B细胞在暴露于高Na+时经历的死亡途径 体外实验。在目标2中，我将在目标3中评估小鼠肾脏Na+环境变化时的B细胞功能 我将利用原位成像来确定人类SLE肾炎中这些致病细胞的功能图景。 活组织检查。总之，这些研究将有助于确定治疗SLE肾炎的肾脏特异性靶点。 该奖项的候选人是一位在肾病学和免疫学方面具有双重专长的内科科学家。她 长期目标是成为一名独立的学术研究人员，专注于自身免疫性肾病和 淋巴细胞与离子的相互作用。这一奖项将允许候选人接受来自 耶鲁大学医学院免疫生物学和肾脏病系，一项重要的研究 机构。一个全面的职业发展计划，课程包括生物信息学和统计学， 收购RNA杂交和成像技术以及专注于Grant和 手稿的准备是为了促进候选人的职业目标，并将通过这个奖项来促进。

Project Summary Lupus nephritis is the kidney manifestation of the autoimmune disease systemic lupus erythematosus (SLE, lupus); 10% of those afflicted progress to end stage kidney disease. Lupus nephritis kidneys are characterized by a profound lymphocytic infiltrate and the degree of infiltrate, including B lymphocytes specifically, correlates with tissue damage and disease severity. Kidneys are also characterized by axial concentration gradients of sodium (Na+), up to 2-fold higher than serum. Thus the inimical kidney environment presents unique survival challenges for infiltrating lymphocytes that may shape their phenotype and function. The function of intrarenal B cells and the pathways they employ to adapt to the hostile kidney environment remain uncharacterized. My preliminary data demonstrate that B cells from lupus-prone mice exhibit enhanced survival when exposed to high Na+ ex vivo as compared to wildtype mice. This effect was mediated by high expression of sodium potassium ATPase (Na+-K+-ATPase, NKA), a key regulator of cellular ionic balance. I have also shown that kidney-infiltrating B cells in murine lupus adapted to elevated [Na+] and that the expression of in vivo NKA correlated with the ability of infiltrating B cells to persist in the kidney. Pharmacological inhibition of NKA and genetic knockout of the NKA g subunit, the latter not previously known to be expressed in B cells, resulted in reduced kidney B cell infiltration and amelioration of proteinuria. B cells in renal biopsies of SLE patients also expressed more NKA than intrarenal T cells, suggesting the same NKA-regulated B cell survival pathway is operative in human SLE nephritis. How Na+ affects cell death pathways and whether it regulates B cell function, such as antibody or cytokine production, is unknown. I hypothesize that Na+ modulates intrarenal B cell death pathways and function, dissection of which will augment understanding of lupus nephritis pathogenesis. In Aim 1, I will investigate death pathways that lupus versus healthy control B cells undergo when exposed to high Na+ ex vivo. In Aim 2, I will assess B cell function upon alteration of kidney Na+ environment in mice while in Aim 3 I will utilize in situ imaging to define the functional landscape of these pathogenic cells in human SLE nephritis biopsies. Together these studies will help identify kidney-specific targets for the treatment of SLE nephritis. The candidate for this award is a physician-scientist with dual expertise in nephrology and immunology. Her long-term goals are to be an independent academic researcher with a focus on autoimmune kidney disease and lymphocyte-ion interactions. This award would allow the candidate to receive exceptional mentorship from the departments of Immunobiology and Nephrology at Yale University School of Medicine, a premier research institution. A comprehensive career development plan with coursework in bioinformatics and statistics, acquisition of RNA hybridization and imaging techniques and professional development focused on grant and manuscript preparation is designed to promote the candidate’s career goals and will be facilitated by this award.