Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.
Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China.
Ren Fail. 2023 Dec;45(1):2149411. doi: 10.1080/0886022X.2022.2149411.
Peritoneal fibrosis caused by long-term peritoneal dialysis (PD) is the main reason why patients withdraw from PD treatment. Lipid accumulation in the peritoneum was shown to participate in fibrosis, and klotho is a molecule involved in lipid metabolism. GSK343 (enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) inhibitor) has been verified to inhibit epithelial mesenchymal transdifferentiation (EMT) and peritoneal fibrosis, but its related mechanism remains unclear. This study aimed to investigate whether lipid accumulation was involved in the effect of GSK343 and its related mechanism.
First, the expression of EZH2, klotho and EMT indices in human peritoneal mesothelial cells (HMrSV5) incubated with high glucose (HG) levels was detected. After EZH2 was inhibited by GSK343, Western blot (WB), wound healing and Transwell assays were used to explore the effect of GSK343. EZH2 and klotho expression was also detected. Oil red O and Nile red staining and triglyceride (TG) detection kits were used to detect lipid accumulation. A rescue experiment with small interfering RNA specific for klotho (si-klotho) on the basis of GSK343 was also conducted to verify that GSK343 exerted its effect klotho. In experiments, rats were administered GSK343, and the related index was assessed.
In our study, we revealed that the expression of EZH2 was significantly upregulated and klotho was significantly downregulated in HMrSV5 cells induced by high glucose. With the aid of GSK343, we found that lipid deposition caused by HG was significantly decreased. In addition, EMT and fibrosis were also significantly alleviated. Moreover, GSK343 could also restore the downregulation of klotho. To further verify whether klotho mediated the effect of EZH2, a rescue experiment with si-klotho was also conducted. The results showed that si-klotho could counteract the protective effect of GSK343 on high glucose-induced lipid accumulation and fibrosis. experiments also revealed that GSK343 could relieve peritoneal fibrosis, lipid deposition and EMT by mitigating EZH2 and restoring klotho expression.
Combining these findings, we found that EZH2 regulated lipid deposition, peritoneal fibrosis, and EMT mediated by klotho. To our knowledge, this is the first study to demonstrate the effect of the EZH2-klotho interaction on peritoneal fibrosis. Hence, EZH2 and klotho could act as potential targets for the treatment of peritoneal fibrosis.
长期腹膜透析（PD）引起的腹膜纤维化是患者停止 PD 治疗的主要原因。脂质在腹膜中的积累被证明参与纤维化，klotho 是参与脂质代谢的分子。GSK343（增强子的锌指 2 多梳抑制复合物 2 亚基（EZH2）抑制剂）已被证实可抑制上皮间质转化（EMT）和腹膜纤维化，但相关机制尚不清楚。本研究旨在探讨脂质积累是否参与 GSK343 的作用及其相关机制。
首先，检测高糖（HG）水平孵育的人腹膜间皮细胞（HMrSV5）中 EZH2、klotho 和 EMT 指标的表达。用 GSK343 抑制 EZH2 后，用 Western blot（WB）、划痕愈合和 Transwell 实验探讨 GSK343 的作用。还检测了 EZH2 和 klotho 的表达。油红 O 和尼罗红染色和甘油三酯（TG）检测试剂盒用于检测脂质积累。在 GSK343 的基础上用 klotho 特异性小干扰 RNA（si-klotho）进行挽救实验，以验证 GSK343 通过 klotho 发挥作用。在实验中，给大鼠给予 GSK343，并评估相关指标。
在本研究中，我们发现高糖诱导的 HMrSV5 细胞中 EZH2 表达明显上调，klotho 表达明显下调。借助 GSK343，我们发现 HG 引起的脂质沉积明显减少。此外，EMT 和纤维化也明显减轻。此外，GSK343 还可以恢复 klotho 的下调。为了进一步验证 klotho 是否介导了 EZH2 的作用，还进行了 si-klotho 的挽救实验。结果表明，si-klotho 可以拮抗 GSK343 对高糖诱导的脂质积累和纤维化的保护作用。实验还表明，GSK343 通过减轻 EZH2 和恢复 klotho 表达来缓解腹膜纤维化、脂质沉积和 EMT。
综上所述，我们发现 EZH2 通过 klotho 调节脂质沉积、腹膜纤维化和 EMT。据我们所知，这是第一项研究表明 EZH2-klotho 相互作用对腹膜纤维化的影响。因此，EZH2 和 klotho 可以作为治疗腹膜纤维化的潜在靶点。
