Zhang Tie-Ning, Huang Xin-Mei, Li Linus, Li Yue, Liu Yong-Ping, Shi Xiao-Lu, Wu Qi-Jun, Wen Ri, Yang Yu-Hang, Zhang Tao, Gong Ting-Ting, Liu Fang-Hua, Liu Chun-Feng, Ning Wanshan, Yang Ni
Department of Pediatrics, PICU, Shengjing Hospital of China Medical University, Shenyang. (T.-N.Z., Y.-P.L., R.W., Y.-H.Y., T.Z., C.-F.L., N.Y.).
Department of Endocrinology, Shanghai Fifth People's Hospital, Fudan University, China (X.-M.H., Y.L.).
Circ Res. 2025 Jun 27. doi: 10.1161/CIRCRESAHA.124.325708.
Serum lactate levels are used to evaluate tissue hypoxia and predict outcomes in cases of sepsis and septic shock. Lactate can participate in a posttranslational modification known as lactylation. Myocardial depression during sepsis and septic shock is common. Here, we investigated the role of lactate in sepsis-induced myocardial depression.
Septic myocardial depression in rats was induced by lipopolysaccharide administration or cecal ligation and puncture. Lactylation and protein profiles of heart tissues from the control and lipopolysaccharide groups were analyzed using proteomic analysis. Lactylation of the HADHA (trifunctional enzyme subunit alpha) at K166 and K728 was detected in septic heart tissues and lipopolysaccharide-induced cultured cells. Mutation of K166 and K728 HADHA were used to clarify the effects of HADHA lactylation on mitochondrial function, ATP production, energy metabolism, and heart function. Transcriptomic and metabolomic analyses were used to identify differentially expressed genes and differential metabolites in H9c2 cells.
We identified 1127 lysine lactylation sites, with 83 differentially lactylated lysine sites. By integrating multifeature hybrid learning and protein language models, we identified lactylation at K166 and K728 of the HADHA as functionally important. We confirmed that lactylation at these sites was influenced by lactate levels and inhibited the HADHA activity, which disturbed mitochondrial function, ATP production, and energy metabolism. This reduction in the contraction force of cardiomyocytes can influence heart function in vitro and in vivo. Furthermore, this study revealed that sirtuin 1 and sirtuin 3 regulated the lactylation of HADHA at K166 and K728.
This study reveals the significant impact of lactylation on cardiomyocyte metabolism. Lactate-induced HADHA lactylation disturbs cardiomyocyte mitochondrial function and metabolism and promotes sepsis-induced cardiac dysfunction. These findings inform the development of new therapeutic targets for sepsis-induced myocardial depression.
血清乳酸水平用于评估组织缺氧情况，并预测脓毒症和脓毒性休克病例的预后。乳酸可参与一种称为乳酰化的翻译后修饰。脓毒症和脓毒性休克期间的心肌抑制较为常见。在此，我们研究了乳酸在脓毒症诱导的心肌抑制中的作用。
通过给予脂多糖或进行盲肠结扎和穿刺诱导大鼠发生脓毒性心肌抑制。使用蛋白质组学分析方法分析对照组和脂多糖组心脏组织的乳酰化和蛋白质谱。在脓毒症心脏组织和脂多糖诱导的培养细胞中检测到3-羟基-3-甲基戊二酰辅酶A（HADHA，三功能酶亚基α）在K166和K728位点的乳酰化。利用K166和K728位点的HADHA突变来阐明HADHA乳酰化对线粒体功能、ATP生成、能量代谢和心脏功能的影响。采用转录组学和代谢组学分析来鉴定H9c2细胞中差异表达的基因和差异代谢物。
我们鉴定出1127个赖氨酸乳酰化位点，其中83个赖氨酸位点存在差异乳酰化。通过整合多特征混合学习和蛋白质语言模型，我们确定HADHA的K166和K728位点的乳酰化具有重要功能。我们证实这些位点的乳酰化受乳酸水平影响，并抑制HADHA活性，进而扰乱线粒体功能、ATP生成和能量代谢。心肌细胞收缩力的这种降低可在体外和体内影响心脏功能。此外，本研究表明沉默调节蛋白1和沉默调节蛋白3调节HADHA在K166和K728位点的乳酰化。
本研究揭示了乳酰化对心肌细胞代谢的重大影响。乳酸诱导的HADHA乳酰化扰乱心肌细胞线粒体功能和代谢，并促进脓毒症诱导的心脏功能障碍。这些发现为脓毒症诱导的心肌抑制新治疗靶点的开发提供了依据。
