中文摘要
肾性高血压是慢性肾脏病进展的结果及危险因素,肾小球和小管间近距离对话和反馈调节是机体调节血压和水盐平衡的重要机制,将在已经建立的肾性高血压、遗传性失盐性肾病患者队列,及A1AR-/-盐敏感性高血压小鼠动物模型中(单肾切除高醛固酮高盐饮食),通过临床、动物实验不同层次,研究坏死性炎症与NCC及管球反馈失衡,导致盐敏感性高血压的具体机制:本研究将在已经建立的肾性高血压队列探讨是否① COX-2与NCC协同调节致密斑和集合管管球反馈对水盐平衡 ②抑制COX-2,改变盐浓度依赖的巨噬细胞表型(M1/M2)转化,促使细胞Caspase-1依赖的焦亡发生和Th1细胞活化放大炎症反应; ③肾脏局部坏死性炎症(焦亡)释放炎症物质(IL-18/IL1β)直接活化其受体NCC,在炎症放大和重吸收盐两种机制导致盐敏感性高血压,为高血压的治疗提供新的线索。
英文摘要
Salt-sensitive hypertension is not only the outcome of chronic kidney disease (CKD), but also the risk factor of the CKD progress. The crosstalk between the tubule and glomeruli plays an important role in keep balance of salt and water . In the present study, CKD patients, A1AR deficient mice with salt-sensitive hypertension will be used to investigate the role of COX-2 in the tubule glomerular feedback (TGF) and glomerulotubular feedback loop induced by necroinflammation. The mechanism of macrophage cells differentiation and pyroptosis amplification will be studied by co-cultured macrophage and tubule cells in vitro. The relationship between the activation of sodium chloride cotransporter (NCC) and IL-18, a new confirmed ligand of NCC and released by pyroptosis ,will be investigated in TGF mechanism and local inflamation pathway.Take together, the present study would like to indentify the mechanism of the crosstalk between tubule and glomeruli, induced by necroinflammation and high salt, implicate a new idea of salt-sensitive hypertension theraphy.
结题摘要
盐敏感高血压不仅是慢性肾脏病(CKD)的结果,也是CKD进展的重要因素,其中肾小球和小管间近距离反馈调节(TGF)是机体调节血压和水盐平衡的重要机制。本研究首先在高血压恶性肾硬化(MHT)队列中观察到肾功能损害重和局部炎症激活,肾小球和小管间质均存在不同程度微血管损伤(CD34阳性),不仅与肾功能显著相关,还是独立预测肾脏结局的危险因素。小管间质周细胞PDGFRβ和巨噬细胞趋化因子CCL2共表达细胞显著高于良性肾硬化与肾小球轻微病变患者,流式细胞术观察到外周血经典型和中间型单核细胞中M2细胞升高,肾间质M2a型为主的巨噬细胞可分泌TGFβ1调节血管微环境和微血管损伤,初步证实了M2a巨噬细胞浸在高血压肾肾小球和小管损伤中的作用。其次我们在先天NCC基因突变导致Gitelman综合征(GS)患者队列(n=150)中观察到全身RAS的活化和低血压,肾脏病理表现为致密斑COX2表达增加和球旁器增生,肾素高表达和肾素产生细胞再募集。更重要的是我们首次观察到GS患者血、尿PGE2 (COX2下游产物)升高,而尿中PGE2代谢产物(PGEM)水平升高与GS的严重程度,其NCC功能损害程度相关(氢氯噻嗪实验),首次为COX2抑制剂有效治疗高尿PGEM的GS患者提供了扎实的依据。最后我们建立了盐敏感性高血压DOCA-Salt小鼠(单肾切除高醛固酮高盐饮食),表现为高血压、NKCC2,NCC表达上调,盐重吸收增加,伴有COX2活化和巨噬细胞浸润(CD68),并没有观察到炎症小体及后续焦亡相关的Caspas-1/IL-18/IL-1β途径的活化。而在阴性对照高尿酸早期高血压小鼠中没有观察到NCC和NKCC2的活化。但在阳性对照为1型糖尿病早期肾损害小鼠中观察到了巨噬细胞浸润,表型改变到NRPL-3焦亡(Caspas-1/IL-18,IL-1β)和近端小管重吸收转运子功能活化的全部过程。3种动物模型均有不同程度腺苷及其受体活化,而在管球反馈缺失(A1AR-/-)基因敲除小鼠中,病理生理的改变进一步加重。说明管球反馈参与多种肾性高血压的发病过程,而巨噬细胞-炎症-焦亡途径并非其必然
