Ni Lihua, Zhou Qiuyuan, Gao Xueyun, Chen Feng, Yusufu Ayinigaer, Chen Jin-Hu, Yuan Cheng, Wu Xiaoyan
Department of Nephrology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, Hubei, China.
Department of Pathology, Liang Ping People's Hospital of Chongqing, Chongqing, 405200, People's Republic of China.
J Transl Med. 2025 Jul 24;23(1):821. doi: 10.1186/s12967-025-06852-1.
Diabetic kidney disease (DKD) is characterized by progressive fibrosis, oxidative stress, and mitochondrial dysfunction, contributing to renal dysfunction. EphrinB2, a cell surface protein, has been implicated in tissue repair and fibrosis, but its role in DKD remains poorly understood. This study investigates the impact of EphrinB2 expression on renal fibrosis, mitochondrial dynamics, and cellular signaling pathways in DKD.
EphrinB2 expression and function were investigated in renal tissues from DKD patients, STZ-induced diabetic mice, and HG-treated HK-2 cells. EphrinB2 overexpression was achieved using AAV in vivo and lentiviral vectors in vitro. Functional assessments included histological and biochemical evaluations, while mechanistic studies utilized siRNA knockdown, pathway-specific inhibitors and activators, and co-immunoprecipitation to explore the role of the Epac1-Rap1 signaling pathway in EphrinB2-mediated antifibrotic and mitochondrial protective effects.
EphrinB2 expression was significantly downregulated in the kidneys of DKD patients and STZ-induced diabetic mice, correlating with increased fibrosis and tubular injury. Overexpression of EphrinB2 (EphrinB2-OE) in diabetic mice restored renal function, reduced fibrosis, alleviated oxidative stress, and preserved mitochondrial structure. In HK-2 cells, EphrinB2-OE mitigated HG-induced fibrosis, reduced ROS levels, and restored MMP and ATP production. Mechanistically, EphrinB2-OE enhanced the Epac1-Rap1 pathway, stabilizing Epac1 protein and promoting mitochondrial biogenesis via PGC-1α. Additionally, EphrinB2-OE modulated the E-cadherin/β-catenin complex and preventing β-catenin nuclear translocation, and preserving epithelial integrity and epithelial-to-mesenchymal transition (EMT).
EphrinB2 exerts protective effects against renal fibrosis and dysfunction in diabetic conditions by regulating fibrosis pathways, mitochondrial dynamics, and epithelial stability. Targeting EphrinB2 signaling presents a promising therapeutic strategy for diabetic kidney disease.
糖尿病肾病（DKD）的特征是进行性纤维化、氧化应激和线粒体功能障碍，导致肾功能不全。EphrinB2是一种细胞表面蛋白，与组织修复和纤维化有关，但其在DKD中的作用仍知之甚少。本研究探讨EphrinB2表达对DKD肾纤维化、线粒体动力学和细胞信号通路的影响。
在DKD患者、链脲佐菌素诱导的糖尿病小鼠的肾组织以及高糖处理的HK-2细胞中研究EphrinB2的表达和功能。通过体内腺相关病毒（AAV）和体外慢病毒载体实现EphrinB2过表达。功能评估包括组织学和生化评估，而机制研究利用小干扰RNA（siRNA）敲低、通路特异性抑制剂和激活剂以及免疫共沉淀来探讨Epac1-Rap1信号通路在EphrinB2介导的抗纤维化和线粒体保护作用中的作用。
DKD患者和链脲佐菌素诱导的糖尿病小鼠肾脏中EphrinB2表达显著下调，与纤维化增加和肾小管损伤相关。糖尿病小鼠中EphrinB2过表达（EphrinB2-OE）恢复了肾功能，减少了纤维化，减轻了氧化应激，并保留了线粒体结构。在HK-2细胞中，EphrinB2-OE减轻了高糖诱导的纤维化，降低了活性氧（ROS）水平，并恢复了线粒体膜电位（MMP）和三磷酸腺苷（ATP）生成。机制上，EphrinB2-OE增强了Epac1-Rap1通路，稳定了Epac1蛋白，并通过过氧化物酶体增殖物激活受体γ共激活因子1α（PGC-1α）促进线粒体生物合成。此外，EphrinB2-OE调节E-钙黏蛋白/β-连环蛋白复合物，防止β-连环蛋白核转位，并维持上皮完整性和上皮-间质转化（EMT）。
EphrinB2通过调节纤维化通路、线粒体动力学和上皮稳定性，对糖尿病状态下的肾纤维化和功能障碍发挥保护作用。靶向EphrinB2信号通路为糖尿病肾病提供了一种有前景的治疗策略。
