Department of Anesthesiology, Affiliated Foshan Hospital of Sun Yat-sen University, Foshan, 528000, China.
Department of Medical Statistics, Foshan Chancheng Central Hospital, Foshan, 528000, China.
Inflamm Res. 2019 Apr;68(4):325-336. doi: 10.1007/s00011-019-01221-3. Epub 2019 Feb 28.
Renal ischemia-reperfusion (IR)-induced acute kidney injury (AKI) remains a major challenge in clinic. The histone methyltransferases enhancer of zest homolog-2 (EZH2) is associated with the development of renal injury. However, the molecular mechanism has not been fully elucidated.
AKI in C57BL/6 mice was generated by renal IR.
The 3-deazaneplanocin A (DZNeP), a selective EZH2 inhibitor, or vehicle was administrated in mice after IR. HK-2 cells were exposed to hypoxia-reoxygenation (H/R) stress.
Apoptosis was detected by TUNEL assay or flow cytometry. EZH2, caspase-3, p38, F4/80 macrophages, and CD3 T cells were examined by immunohistochemistry or Western blot. Tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, IL-6, and IL-18 were measured using RT-PCR.
Mice treated with DZNeP exhibited less severe renal dysfunction and tubular injury following IR. EZH2 inhibition decreased apoptotic cells while reducing activation of caspase-3 in kidneys under IR condition. Moreover, EZH2 inhibition impaired the recruitment of CD3 T cells and F4/80 cells in kidneys with IR. Administration of DZNeP suppressed the production of TNF-α, MCP-1, IL-6, and IL-18 in IR-treated kidneys. Of note, EZH2 inhibition reduced p38 phosphorylation in kidneys after IR. In H/R-treated HK-2 cells, DZNeP treatment or EZH2 knockdown reduced apoptosis. EZH2 inhibition inactivated p38 resulting in reduction of active caspase-3 and proinflammatory molecules. By contrast, EZH2 overexpression induced p38 phosphorylation, caspase-3 activation, and production of proinflammatory molecules, which was reversed by SB203580.
EZH2 plays a crucial role in IR-induced AKI via modulation of p38 signaling. Targeting EZH2/p38 signaling pathway may offer novel strategies to protect kidneys from acute kidney injury induced by ischemia-reperfusion.
肾缺血再灌注（IR）引起的急性肾损伤（AKI）仍然是临床的主要挑战。组蛋白甲基转移酶增强子的 zest 同源物-2（EZH2）与肾损伤的发展有关。然而，其分子机制尚未完全阐明。
通过肾 IR 在 C57BL/6 小鼠中产生 AKI。
在 IR 后，用 3-去氮杂胞苷（DZNeP），一种选择性的 EZH2 抑制剂，或载体对小鼠进行处理。HK-2 细胞暴露于缺氧再氧合（H/R）应激下。
通过 TUNEL 检测或流式细胞术检测细胞凋亡。用免疫组化或 Western blot 检测 EZH2、caspase-3、p38、F4/80 巨噬细胞和 CD3 T 细胞。用 RT-PCR 测量肿瘤坏死因子（TNF）-α、单核细胞趋化蛋白（MCP）-1、IL-6 和 IL-18。
用 DZNeP 处理的小鼠在 IR 后表现出较轻的肾功能障碍和肾小管损伤。EZH2 抑制减少了凋亡细胞，同时降低了 IR 条件下肾脏中 caspase-3 的激活。此外，EZH2 抑制 IR 肾脏中 CD3 T 细胞和 F4/80 细胞的募集。给予 DZNeP 可抑制 IR 处理肾脏中 TNF-α、MCP-1、IL-6 和 IL-18 的产生。值得注意的是，EZH2 抑制可减少 IR 后肾脏中 p38 的磷酸化。在 H/R 处理的 HK-2 细胞中，DZNeP 处理或 EZH2 敲低减少了细胞凋亡。EZH2 抑制使 p38 失活，导致活性 caspase-3 和促炎分子减少。相反，EZH2 过表达诱导 p38 磷酸化、caspase-3 激活和促炎分子的产生，这些被 SB203580 逆转。
EZH2 通过调节 p38 信号通路在 IR 诱导的 AKI 中发挥关键作用。靶向 EZH2/p38 信号通路可能为保护肾脏免受缺血再灌注引起的急性肾损伤提供新的策略。
