肾小管上皮细胞雄激素受体(AR)/CSF-1信号介导的巨噬细胞极化及吞噬功能在草酸钙肾结石形成中的作用研究

Males develop kidney stones far more frequently than age-matched females. Patients with kidney stones had significantly higher testosterone concentrations than age-matched non-stone-forming individuals. The evidence suggested that androgen receptor (AR) signaling might play a key role in the development of nephrolithiasis. Our preliminary data showed higher AR expression in the kidney of patients with kidney stones than in non-stone-forming patients. Using the cre-loxP system to selectively knock out AR in glyoxylate-induced calcium oxalate (CaOx) crystals mouse models, we found that the mice lacking distal epithelial AR had lower CaOx crystals formation. We found that knocking-down AR in renal tubular epithelial cells could increase the macrophage recruitment/M2 polarization that might then result in enhancing the phagocytosis of CaOx crystals via up-regulating CSF-1. However, the underlying mechanism how AR regulates CSF-1 and how CSF-1 regulates macrophage recruitment/function remain unclarified. In this study, we will further investigate the function and mechanism of AR in the regulation of CSF-1, macrophage function and CaOx crystals formation via using multiple in vitro cell lines and in vivo distal epithelial AR knockout mouse models. The study could provide new experimental evidence for the pathogenesis of CaOx stones formation and may help to develop the novel therapies to better suppress the kidney stone formation or recurrence.

泌尿系结石男性发病率高于女性，且结石患者体内睾酮水平明显高于非结石患者，提示雄激素受体（AR）可能在结石形成过程中具有重要的作用。我们前期结果表明AR在草酸钙结石患者肾组织的表达显著高于非结石人群。在小鼠草酸钙结石模型中，特异性敲除肾小管上皮细胞AR可明显减少草酸钙晶体的形成，初步证实抑制AR可减少草酸钙晶体形成。进一步研究发现肾小管上皮细胞AR可能通过抑制集落刺激因子-1（CSF-1）的分泌，继而减少了肾脏巨噬细胞的募集、M2极化以及吞噬草酸钙晶体的功能，从而影响肾脏清除草酸钙晶体的能力，最终促进了结石的形成。然而，AR如何调控CSF-1及如何通过CSF-1影响巨噬细胞的募集及功能的具体机制仍不清楚。本项目拟通过多种细胞模型和AR肾脏靶向敲除小鼠模型进一步揭示AR调控CSF-1，巨噬细胞和草酸钙结石形成的作用及分子机制，从而为揭示草酸钙结石的发病机制和临床防治提供新的实验依据和干预策略。

泌尿系结石男性发病率高于女性，且结石患者体内睾酮水平明显高于非结石患者，提示雄激素受体(AR)可能在结石形成过程中具有重要的作用。目前有研究表明巨噬细胞参与了草酸钙结石的形成，但其具体机制以及与性激素的关系仍未阐明。本研究发现沉默肾小管上皮细胞雄激素受体可促进巨噬细胞的募集及M2极化，从而增加了巨噬细胞吞噬草酸钙晶体的功能。进一步机制研究表明雄激素受体可以通过增加miRNA-185-5p表达抑制CSF-1的分泌，从而影响了巨噬细胞吞噬草酸钙晶体的功能。动物实验表明肾小管上皮细胞特异性雄激素敲除小鼠其草酸钙晶体形成要明显少于对照组，同时伴有M2巨噬细胞的增加。因此，本研究通过体内外实验证实沉默肾小管上皮细胞雄激素受体可促进巨噬细胞的募集及M2极化从而减少了肾脏草酸钙晶体的形成。雄激素受体可作为合并高草酸尿肾结石的潜在靶点。该项目拓展了泌尿系结石病因及预防的研究思路，为改进泌尿系结石的治疗方案提供了理论依据及支持。