基于宏基因组学探讨肾病II号方防治IgA肾病单纯性血尿的作用机制

Hematuria is the most common symptom of Immunoglobulin A nephropathy (IgAN). However, there is lacking effective treatment. Previous studies had presented evidence that gut microbiota play a role in the occurrence of IgAN, but the etiology and the mechanism of its development require further elucidation. A previous investigation by us had found that remarkable changes took place in the construction of gut microbiota among the patients with IgAN asymptomatic hematuria, and it could be recover by the treatment of Shenbingerhao Decoction, which had been developed by our group and had been showed significant effect for asymptomatic hematuria. Accordingly, we theorize that the abnormal gut microbiota may play an important role in the occurrence of IgAN asymptomatic hematuria. Basing on the previous study, in this project, we aim to investigate the change characteristics of gut microbiota in patients with IgAN asymptomatic hematuria clinically, and in the making animal model of the mouse with IgAN asymptomatic hematuria, by the intervention means of Shenbingerhao Decoction, and the technology of metagenomics. Secondly, we will investigate how the gut microbiota impact the occurrence of IgAN asymptomatic hematuria, by applying the germ free mice and the fecal microbiota transplantation and observing the immune function, erythrocyte function, and related molecules of microvascular endothelial cell and glomerular cell. Eventually, conducting bioinformatics method for integrated analysis, we will ascertain how the unbalance of homeostasis in gut microbiota works in the impact of glomerular cells and red blood cells, and in the development of IgAN asymptomatic hematuria, confirm the regulation mechanism of gut microbiota in the treatment of IgAN asymptomatic hematuria by Shenbingerhao Decoction, intending to provide experiment evidence for clinical adoption.

血尿为IgA肾病（IgAN）最常见的临床症状，然而其治疗手段有限。诸多证据表明：肠道微生物参与了IgAN的发病过程，但其机制迄今尚未阐明。我们前期研究发现IgAN单纯性血尿患者肠道菌群结构发生显著的变化，而经过中药复方“肾病II号方”治疗后可使其肠道菌群结构异常向正常水平恢复。推测肠道菌群紊乱可能在IgAN单纯性血尿发生发展中起到重要作用。本项目拟在前期的基础上，采取临床研究结合动物实验，以肾病II号方为干预手段，首先应用宏基因组学方法，明确IgAN单纯性血尿肠道菌群的变化特征；其次，利用无菌小鼠结合粪菌移植技术，观测免疫功能、红细胞功能、微血管内皮细胞以及肾小球细胞相关分子表达情况等指标，探讨肠道微生物对IgAN单纯性血尿发生的影响；最后，利用生物信息学方法进行整合分析，阐明肠道菌群稳态失衡在IgAN单纯性血尿发生中的作用及“肾病II号方”的调节机制，为其临床应用提供实验依据。

IgA肾病是导致终末期肾衰竭的重要原因之一，然而其治疗手段有限。课题组前期研究表明肾病Ⅱ号方治疗IgA肾病疗效显著，但具体机制尚未完全阐明。本项目在前期研究的基础上，首先开展肾病Ⅱ号方治疗IgA肾病单纯性血尿的临床研究和肠道微生物分析，结果显示肾病Ⅱ号方治疗IgA肾病单纯性血尿的临床疗效与血尿安胶囊接近，能降低患者中医证候积分、尿红细胞计数、D-二聚体，改善患者生存质量、降低血清MCP-1和TNF-α的水平；同时发现IgA肾病单纯性血尿患者的肠道微生物出现失衡，如Firmicutes（厚壁菌门）丰度减少，Bacteroidetes（拟杆菌门）丰度增多，而肾病Ⅱ号方干预后，部分菌群有向正常转化的趋势。其次开展肾病Ⅱ号方治疗IgA肾病大鼠的研究，并利用粪菌移植技术验证肠道菌群对IgA肾病的作用及肾病Ⅱ号方的干预效应，结果与临床研究相符。总之，本项目初步阐明了肠道微生物的稳态失衡在IgA肾病发生发展中的作用，同时明确了肾病Ⅱ号方治疗IgA肾病的机制，为其临床应用提供科学依据。在完成本项目的基础上，进一步通过代谢组学方法，发现肾病Ⅱ号方主要通过参与能量代谢、肌酸代谢及甲胺代谢的调控治疗IgA肾病。