Ni Weijie, Zhao Yajie, Shen Jinxin, Yin Qing, Wang Yao, Li Zuolin, Tang Taotao, Wen Yi, Zhang Yilin, Jiang Wei, Jiang Liangyunzi, Wei Jinxuan, Gan Weihua, Zhang Aiqing, Zhou Xiaoyu, Wang Bin, Liu Bi-Cheng
Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu 210003, China.
Department of Pediatric Nephrology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, China.
Chin Med J (Engl). 2025 Jan 20;138(2):193-204. doi: 10.1097/CM9.0000000000002978. Epub 2024 Mar 6.
Chronic kidney disease (CKD) is associated with common pathophysiological processes, such as inflammation and fibrosis, in both the heart and the kidney. However, the underlying molecular mechanisms that drive these processes are not yet fully understood. Therefore, this study focused on the molecular mechanism of heart and kidney injury in CKD.
We generated an microRNA (miR)-26a knockout (KO) mouse model to investigate the role of miR-26a in angiotensin (Ang)-II-induced cardiac and renal injury. We performed Ang-II modeling in wild type (WT) mice and miR-26a KO mice, with six mice in each group. In addition, Ang-II-treated AC16 cells and HK2 cells were used as in vitro models of cardiac and renal injury in the context of CKD. Histological staining, immunohistochemistry, quantitative real-time polymerase chain reaction (PCR), and Western blotting were applied to study the regulation of miR-26a on Ang-II-induced cardiac and renal injury. Immunofluorescence reporter assays were used to detect downstream genes of miR-26a, and immunoprecipitation was employed to identify the interacting protein of LIM and senescent cell antigen-like domain 1 (LIMS1). We also used an adeno-associated virus (AAV) to supplement LIMS1 and explored the specific regulatory mechanism of miR-26a on Ang-II-induced cardiac and renal injury. Dunnett's multiple comparison and t -test were used to analyze the data.
Compared with the control mice, miR-26a expression was significantly downregulated in both the kidney and the heart after Ang-II infusion. Our study identified LIMS1 as a novel target gene of miR-26a in both heart and kidney tissues. Downregulation of miR-26a activated the LIMS1/integrin-linked kinase (ILK) signaling pathway in the heart and kidney, which represents a common molecular mechanism underlying inflammation and fibrosis in heart and kidney tissues during CKD. Furthermore, knockout of miR-26a worsened inflammation and fibrosis in the heart and kidney by inhibiting the LIMS1/ILK signaling pathway; on the contrary, supplementation with exogenous miR-26a reversed all these changes.
Our findings suggest that miR-26a could be a promising therapeutic target for the treatment of cardiorenal injury in CKD. This is attributed to its ability to regulate the LIMS1/ILK signaling pathway, which represents a common molecular mechanism in both heart and kidney tissues.
慢性肾脏病（CKD）与心脏和肾脏中常见的病理生理过程相关，如炎症和纤维化。然而，驱动这些过程的潜在分子机制尚未完全明确。因此，本研究聚焦于CKD中心脏和肾脏损伤的分子机制。
我们构建了一种微小RNA（miR）-26a基因敲除（KO）小鼠模型，以研究miR-26a在血管紧张素（Ang）-II诱导的心脏和肾脏损伤中的作用。我们在野生型（WT）小鼠和miR-26a KO小鼠中进行了Ang-II造模，每组6只小鼠。此外，用Ang-II处理的AC16细胞和HK2细胞作为CKD背景下心脏和肾脏损伤的体外模型。应用组织学染色、免疫组织化学、定量实时聚合酶链反应（PCR）和蛋白质印迹法研究miR-26a对Ang-II诱导的心脏和肾脏损伤的调控作用。采用免疫荧光报告基因检测法检测miR-26a的下游基因，采用免疫沉淀法鉴定LIM和衰老细胞抗原样结构域1（LIMS1）的相互作用蛋白。我们还使用腺相关病毒（AAV）补充LIMS1，并探讨miR-26a对Ang-II诱导的心脏和肾脏损伤的具体调控机制。采用Dunnett多重比较和t检验分析数据。
与对照小鼠相比，输注Ang-II后，肾脏和心脏中miR-26a的表达均显著下调。我们的研究确定LIMS1是心脏和肾脏组织中miR-26a的一个新靶基因。miR-26a的下调激活了心脏和肾脏中的LIMS1/整合素连接激酶（ILK）信号通路，这是CKD期间心脏和肾脏组织中炎症和纤维化的共同分子机制。此外，敲除miR-26a通过抑制LIMS1/ILK信号通路加重了心脏和肾脏的炎症和纤维化；相反，补充外源性miR-26a逆转了所有这些变化。
我们的研究结果表明，miR-26a可能是治疗CKD中心脏和肾脏损伤的一个有前景的治疗靶点。这归因于其调节LIMS1/ILK信号通路的能力，这是心脏和肾脏组织中的一个共同分子机制。
