METTL3 promotes podocyte pyroptosis in diabetic nephropathy through N⁶-methyladenosine modification of TRIM29 mRNA

Multiple studies have revealed the critical roles of epigenetic modifications in the development of diabetic nephropathy (DN). Methyltransferase-like 3 (METTL3)-mediated N⁶-methyladenosine (m6A) RNA modification in podocytes represents a new disease mechanism in DN. The tripartite motif-containing (TRIM) family member TRIM29 was reported to promote podocyte pyroptosis by activating the nuclear factor-κB/NLR family pyrin domain containing 3 (NLRP3) inflammasome pathway. However, whether METTL3-mediated m6A modification of TRIM29 mRNA is involved in podocyte injury remain unknown. Here, we found that METTL3 upregulated the m6A content in mRNA from kidney tissues of mice with streptozotocin-induced DN and in hyperglycemia-induced MPC-5 murine podocytes. METTL3 expression in high glucose-treated MPC-5 cells resulted in elevated release of interleukin (IL)-1β, IL-18, and lactate dehydrogenase and upregulated expression of pyroptosis-associated molecules. Mechanistically, METTL3 was found to directly target TRIM29 for m6A modification and activate TRIM29 transcription. Moreover, the m6A reader YT521-B homology (YTH) domain family member YTHDF1 was recruited by METTL3 to maintain the stability of TRIM29 mRNA, which contributed significantly to increased podocyte pyroptosis. Furthermore, the potent METTL3-specific inhibitor STM2457 prominently alleviated podocyte injury through attenuating activation of the NLRP3 inflammasome/pyroptosis pathway in the DN mouse model. Our results suggest that METTL3 plays a critical role in hyperglycemia-induced podocyte injury through m6A modification of TRIM29 mRNA, which provides new insight for the development of METTL3- and pyroptosis-targeted strategies to treat DN and other diabetic kidney diseases.

多项研究已揭示表观遗传修饰（epigenetic modifications）在糖尿病肾病（diabetic nephropathy, DN）发生发展中的关键作用。甲基转移酶样3（Methyltransferase-like 3, METTL3）介导的足细胞（podocytes）N⁶-甲基腺苷（N⁶-methyladenosine, m⁶A）RNA修饰，是糖尿病肾病的全新发病机制。有研究表明，三重基序（tripartite motif-containing, TRIM）家族成员TRIM29可通过激活核因子κB/NLR家族pyrin结构域包含3（NLR family pyrin domain containing 3, NLRP3）炎症小体通路，促进足细胞焦亡。然而，METTL3介导的TRIM29 mRNA的m⁶A修饰是否参与足细胞损伤，目前尚未明确。本研究发现，在链脲佐菌素诱导的糖尿病肾病小鼠肾组织，以及高糖诱导的MPC-5小鼠足细胞中，METTL3均可上调mRNA的m⁶A修饰水平。在高糖处理的MPC-5细胞中过表达METTL3，可使白细胞介素（interleukin, IL）-1β、IL-18及乳酸脱氢酶的释放量升高，并上调焦亡相关分子的表达。机制研究显示，METTL3可直接靶向TRIM29进行m⁶A修饰，并激活TRIM29的转录。此外，m⁶A阅读蛋白YT521-B同源域（YT521-B homology, YTH）家族成员YTHDF1可被METTL3招募，以维持TRIM29 mRNA的稳定性，这显著促进了足细胞焦亡。进一步实验证实，强效METTL3特异性抑制剂STM2457可通过抑制糖尿病肾病小鼠模型中NLRP3炎症小体/焦亡通路的活化，显著减轻足细胞损伤。本研究结果表明，METTL3可通过介导TRIM29 mRNA的m⁶A修饰，在高糖诱导的足细胞损伤中发挥关键作用，这为开发靶向METTL3及焦亡的治疗策略以治疗糖尿病肾病及其他糖尿病肾脏疾病提供了全新的研究视角。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于糖尿病肾病中METTL3通过N6-甲基腺苷（m6A）修饰TRIM29 mRNA促进肾小球足细胞焦亡的机制研究，包含来自小鼠模型和细胞系的实验数据，揭示了YTHDF1介导的TRIM29 mRNA稳定性调控及NLRP3炎症小体通路的作用。数据集提供了原始研究数据，支持表观遗传修饰在疾病治疗中的潜在应用，并涉及METTL3抑制剂STM2457的治疗效果验证。