This study investigated the role of N6-methyladenosine RNA methylation in liver regeneration following partial hepatectomy in mice. We created a liver-specific knockout mouse model by the deletion of Mettl3, a key component of the N6-methyladenosine methyltransferase complex, using the albumin-Cre system. Mettl3 liver-specific knockout mice and their wild-type littermates were subjected to 2/3 partial hepatectomy. Transcriptomic changes in liver tissue at 48 h after partial hepatectomy were detected by RNA-seq. Immunohistochemistry and immunofluorescence were used to determine protein expression levels of Ki67, hepatocyte nuclear factor 4 alpha, and cytokeratin 19. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling was also performed. Liver weight/body weight ratios after partial hepatectomy were significantly lower in Mettl3 liver-specific knockout mice than in wild-type mice at 48 h after 2/3 partial hepatectomy (3.1% ± 0.11% vs. 2.7% ± 0.03%). Compared with wild-type littermates, Mettl3 liver-specific knockout mice showed reduced bromodeoxyuridine staining and reduced Ki-67 expression at 48 h after 2/3 partial hepatectomy. RNA-seq analysis showed that Mettl3 liver-specific knockout delayed the cell cycle progression in murine liver by downregulating the expression levels of genes encoding cyclins D1, A2, B1, and B2. Loss of Mettl3-mediated N6-methyladenosine function led to attenuated liver regeneration by altering the mRNA decay of suppressor of cytokine signaling 6, thereby inhibiting the phosphorylation of signal transducer and activator of transcription 3 during early liver regeneration. These results demonstrated the importance of N6-methyladenosine mRNA modification in liver regeneration and suggest that Mettl3 targeting might facilitate liver regeneration.

本研究调查了 N6-甲基腺苷 RNA 甲基化在小鼠部分肝切除术后肝再生中的作用。我们使用白蛋白-Cre 系统通过删除 Mettl3（N6-甲基腺苷甲基转移酶复合物的关键成分）创建了肝脏特异性敲除小鼠模型。对 Mettl3 肝脏特异性敲除小鼠及其野生型同窝小鼠进行 2/3 部分肝切除术。通过 RNA-seq 检测肝部分切除术后 48 小时肝组织的转录组变化。免疫组织化学和免疫荧光用于确定 Ki67、肝细胞核因子 4 α 和细胞角蛋白 19 的蛋白质表达水平。还进行了末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记。对比2.7% ± 0.03%）。与野生型同窝小鼠相比，Mettl3 肝脏特异性敲除小鼠在 2/3 部分肝切除术后 48 小时表现出溴脱氧尿苷染色减少和 Ki-67 表达减少。RNA-seq 分析表明，Mettl3 肝脏特异性敲除通过下调编码细胞周期蛋白 D1、A2、B1 和 B2 的基因的表达水平来延迟小鼠肝脏中的细胞周期进程。Mettl3 介导的 N6-甲基腺苷功能的丧失通过改变细胞因子信号 6 抑制因子的 mRNA 衰变导致肝再生减弱，从而在早期肝再生过程中抑制信号转导因子和转录激活因子 3 的磷酸化。这些结果证明了 N6-甲基腺苷 mRNA 修饰在肝再生中的重要性，并表明 Mettl3 靶向可能促进肝再生。