Renal macrophages in the pathogenesis of human urinary stones and Randall's plaque formation in mice

项目概要/摘要： 泌尿系结石病（USD）是男性和女性中第三大最常见和最痛苦的泌尿系统疾病。 预防USD及其相关费用和发病率需要了解早期和晚期USD 发病机制新出现的证据表明，肾内晶体成核，生长， 吞噬细胞反应在USD中起关键但未被认识的作用。体外研究表明， 磷酸钙（CaP）和草酸钙（CaOx）晶体诱导肾小管和吞噬细胞 细胞因子、趋化因子和细胞外囊泡（EV;外来体和微囊泡）的分泌。这些 生物标志物可以吸引血液或驻留单核细胞并将单核细胞转化为pro（M1）或anti-（M2）。 炎性巨噬细胞（Mφ’s）。在实验动物模型和人体组织中的观察表明， 肾组织单核细胞和Mφ可以吞噬和代谢晶体， 骨髓M1群增加，M2群减少。在高尿酸小鼠模型中， 抑制单核细胞向M2 Mφ转化显著增加肾内CaOx沉积。我们的研究 还证明，带有源自特定节段的炎症标记物的电动汽车的尿液排泄 特发性钙结石形成者（ICSF）的肾小管上皮细胞数量显著低于对照组。 因此，多种证据表明，肾小管和单核细胞来源的Mφ群体可以吞噬 并作为晶体清除机制使晶体退化，这些清除机制中的缺陷可 导致间质性兰德尔氏斑块（RP）和集合管堵塞（CDP），甚至直接生长为USD。的 建议的研究项目旨在评估的作用，Mφ的RP和CDP形成使用一种新的 高钙尿紧密连接蛋白-2整体敲除小鼠模型（超过3-24月龄），其类似于 特发性高钙尿症和USD患者（目的1），并确定频率和空间分布， 单核细胞/ Mφ群体在仔细表型ICSF（20-70岁）与羟基磷灰石，透钙磷石， 草酸钙结石和不同量的RP（目的2）。拟议的创新研究将阐明 肾髓质促炎和抗炎吞噬细胞在RP、CDP和USD发生中的作用 以及尿细胞因子、趋化因子或EV是否携带促炎/抗炎吞噬细胞的生物标志物， 细胞可用于非侵入性地监测肾内晶体沉积。完成这项研究还将 促进形成一个熟练的多学科团队，包括一个有前途的早期外科医生-科学家（博士 Kevin Koo）在经验丰富和熟练的USD临床和研究人员（Lieske博士）的指导下进行。的 初步数据将证明我们的团队的有效性。这项工作还将使 提交未来详细的赠款或中心的建议，将扩大这些机制的研究，并已 阐明USD发生的潜在致病步骤和确定新的治疗靶点的巨大潜力。

Project Summary/Abstract: Urinary stone disease (USD) is third most common and painful urological disease in men and women. Prevention of USD and its associated costs and morbidity requires an understanding of early and late USD pathogenesis. Emerging evidence suggests interactions between intrarenal crystal nucleation, growth, and phagocytic cellular responses plays a key but unrecognized role in USD. Studies in vitro demonstrate that calcium phosphate (CaP) and calcium oxalate (CaOx) crystals induce renal tubular and phagocytic cell secretion of cytokines, chemokines, and extracellular vesicles (EVs; exosomes and microvesicles). These biomarkers can attract blood or residential monocytes and convert monocytes into pro (M1) or anti (M2)- inflammatory macrophages (Mφ’s). Observations in experimental animal models and human tissues suggests that renal tissue monocytes and Mφ’s can phagocytose and metabolize crystals, and urinary stone formers appear to have increased medullary M1 and decreased M2 Mφ populations. In a hyperoxaluric mouse model, suppression of monocyte to M2 Mφ conversion significantly increased intrarenal CaOx deposition. Our studies also demonstrated that urinary excretion of EVs bearing inflammatory markers derived from specific segments of renal tubules were significantly lower in idiopathic calcium stone formers (ICSFs) compared to controls. Thus, multiple lines of evidence suggest that tubular and monocyte derived Mφ populations can phagocytose and degrade crystals as a crystal clearance mechanism, and defects in these clearance mechanisms could result in interstitial Randall’s plaque (RP) and collecting duct plugs (CDP) or even grow directly into USD. The proposed research project is designed to evaluate the role of Mφ’s in RP and CDP formation using a novel hypercalciuric claudin-2 global knockout mouse model (over 3-24 months age) that resembles the phenotype of patients with idiopathic hypercalciuria and USD (Aim 1), and to define the frequency and spatial distribution of monocyte/ Mφ populations in carefully phenotyped ICSFs (20-70 years) with hydroxyapatite, brushite, and calcium oxalate stones and varying amounts of RP (Aim 2). The proposed innovative study will elucidate the role of renal medullary pro-and anti-inflammatory phagocytic cells in the development of RP, CDP, and USD and whether urinary cytokines, chemokines or EVs carrying biomarkers of pro-/anti-inflammatory phagocytic cells can be used to non-invasively monitor intrarenal crystal deposition. Completion of this study will also facilitate the formation of a skilled multidisciplinary team including a promising early-stage surgeon-scientist (Dr Kevin Koo) under the mentorship of an experienced and skilled USD clinical and researcher (Dr. Lieske). The resulting preliminary data will provide evidence of the effectiveness of our team. This work will also enable submission of future detailed grant or center proposals that will extend these mechanistic studies, and has great potential to elucidate underlying pathogenic steps in USD genesis and identify novel therapeutic targets.