急性肾损伤进展至慢性肾脏病生物标记物及相关机制的研究

Increased evidence indicates that acute kidney injury (AKI) is a common renal disease with high morbidity and poor long-term prognosis. Even though the kidneys have strong self repair ability, about 35-71% of patients surviving an episode of AKI have incomplete renal recovery and eventually progress to chronic kidney disease (CKD) or end-stage renal disease (ESRD). Therefore, exploring the specific biomarkers and potential mechanisms of successful repair or progression to fibrosis after renal injury is very important and will be beneficial for early diagnosis and intervention of AKI-to-CKD transition. In our present study, we establish two different AKI-to-CKD models, including unilateral ischemia/reperfusion injury (UIRI) with contralateral nephrectomy model and reversible unilateral ureteral obstruction (RUUO) with contralateral nephrectomy model. Both models are established with adaptive repair group, maladaptive repair group and control group. Proteomics and microRNA approaches will be used to explore the specific biomarkers of AKI-to-CKD transition. Transgenic mice and multiple experimental methods will be used to study the roles of macrophage, autophagy, peritubular capillaries and Wnt/β-catenin pathway in AKI to CKD transition. Furthermore, a clinical trial will be performed on the AKI patients to confirm the utility of these specific biomarkers in predicting AKI outcomes. This study has important scientific value and clinical significance. These specific AKI-to-CKD biomarkers will provide a new target for AKI-to-CKD diagnosis and treatment and improve the prognosis of AKI patients.

大量证据表明急性肾损伤（AKI）远期预后不良。尽管肾脏具有强大的修复功能，但仍有35%-71%的AKI由于修复失败进展为慢性肾脏病（CKD）。因此，解明肾损伤后肾脏成功修复或进展为纤维化的机制并寻找该转折点的相关生物标记物，对探索诊疗新靶点及制定有效干预措施至关重要。本课题根据预实验建立两种AKI致CKD动物模型，即单侧缺血再灌注损伤伴对侧肾切除小鼠模型及单侧输尿管梗阻再通伴对侧肾切除小鼠模型，两种模型均设立良性修复组、不良修复组及对照组，通过蛋白质组学及microRNA组学筛选能够提示AKI不良转归的生物学标志物，并利用转基因鼠及多种实验方法探索巨噬细胞、自噬、管周毛细血管及Wnt/β-catenin通路在AKI致CKD过程中发挥的作用及相关机制。同时收集AKI患者血、尿标本，从临床验证这些标记物是否可以预测AKI转归，为阻止AKI进展为CKD提供新的诊疗靶点，改善AKI预后。

大量证据表明急性肾损伤（AKI）远期预后不良。尽管肾脏具有强大的修复功能，但仍有35%-71%的AKI由于修复失败进展为慢性肾脏病（CKD）。因此，解明肾损伤后肾脏成功修复或进展为纤维化的机制并寻找该转折点的相关生物标记物，对探索诊疗新靶点及制定有效干预措施至关重要。本研究建立两种AKI致CKD动物模型，包括单侧缺血再灌注损伤伴对侧肾切除（IRI-AKI）小鼠模型及单侧输尿管梗阻再通伴对侧肾切除（RUUO）小鼠模型，每种模型均设立AKI良性修复组、不良修复组和对照组，模拟AKI完全恢复或AKI发展至CKD的疾病过程。在AKI进展至CKD动物模型中研究巨噬细胞、自噬、管周毛细血管（PTC）、缺氧诱导因子（HIF）以及Wnt/β-catenin通路在疾病不同时期的变化情况、所发挥的作用及相关机制，寻找潜在的可以预示AKI进展至CKD的生物学标记物。在对IRI-AKI模型的研究中，在不同修复结局的IRI-AKI小鼠肾组织中，HIF具有不同的代谢动力学特点。在良性修复组，HIF-1α和HIF-2α在AKI后迅速、充分表达，促进损伤肾脏完全修复。在不良修复组，HIF-1α和HIF-2α表达迟滞，在修复早期由于表达量低，不足以维持受损肾脏修复，最终导致不良性修复，AKI进展至CKD。在AKI修复期，小鼠肾组织HIF和β-catenin的表达密切相关。体外研究进一步发现，HIF-1α与Wnt/β-catenin信号通路相互作用，促进HK-2细胞增殖和迁移，抑制细胞凋亡，减轻H/R对肾小管上皮细胞造成的损伤；HIF-2α在EA.hy926细胞通过影响β-catenin及其下游的表达，保护血管内皮细胞免受缺氧损伤的影响。因此，HIF通过与Wnt/β-catenin信号通路相互作用发挥肾脏保护作用。另外，我们还完成临床研究，探讨罗沙司他（第一代HIF脯氨酸羟化酶抑制剂）治疗中国腹膜透析患者肾性贫血的疗效和安全性。