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病。狼疮性肾炎的症状有哪些？ 淋巴细胞浸润和浸润程度，特别是B淋巴细胞， 组织损伤和疾病严重程度。肾脏的特征还在于： 钠（Na+），比血清高2倍。因此，在不利的肾脏环境中， 对浸润淋巴细胞的挑战，可能会塑造他们的表型和功能。肾内B功能 细胞和它们用于适应不利的肾脏环境的途径仍然没有被表征。 我的初步数据表明，来自狼疮倾向小鼠的B细胞在暴露于 与野生型小鼠相比，离体高Na+。这种作用是由高表达的钠离子介导的。 钾ATP酶（Na+-K+-ATP酶，NKA），细胞离子平衡的关键调节剂。我还证明了， 狼疮鼠肾脏浸润B细胞对高Na+的适应性及体内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的药理学抑制和 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细胞浸润和改善蛋白尿。SLE患者肾活检组织中的B细胞也 比肾内T细胞表达更多的NKA，这表明相同的NKA调节的B细胞存活途径， 在人类SLE肾炎中有效。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产生。我推测Na+调节肾内B细胞死亡 通路和功能，解剖将增加对狼疮性肾炎发病机制的理解。在Aim中 1.我将研究狼疮与健康对照B细胞在暴露于高Na+时的死亡途径 离体。在目标2中，我将评估B细胞在小鼠肾脏Na+环境改变时的功能，而在目标3中， 我将利用原位成像来确定这些致病细胞在人类SLE肾炎中的功能景观 活组织检查这些研究将有助于确定SLE肾炎治疗的肾脏特异性靶点。 该奖项的候选人是一位具有肾脏学和免疫学双重专业知识的医生科学家。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， 淋巴细胞-离子相互作用。这一奖项将使候选人获得特殊的指导，从 耶鲁大学医学院免疫生物学和肾脏病学系， 机构。全面的职业发展计划，包括生物信息学和统计学课程， 获得RNA杂交和成像技术和专业发展，重点是赠款和 手稿的准备是为了促进候选人的职业目标，并将促进这个奖项。

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.