State Key Laboratory of Cell Differentiation and Regulation, Henan International Joint Laboratory of Pulmonary Fibrosis, Henan Center for Outstanding Overseas Scientists of Organ Fibrosis, Pingyuan Laboratory, College of Life Science, Henan Normal University, Xinxiang 453007, China.
J Mol Cell Biol. 2024 Oct 21;16(5). doi: 10.1093/jmcb/mjae021.
Idiopathic pulmonary fibrosis (IPF) is a lethal progressive fibrotic lung disease. The development of IPF involves different molecular and cellular processes, and recent studies indicate that lactate plays a significant role in promoting the progression of the disease. Nevertheless, the mechanism by which lactate metabolism is regulated and the downstream effects remain unclear. The molecular chaperone CCT6A performs multiple functions in a variety of biological processes. Our research has identified a potential association between CCT6A and serum lactate levels in IPF patients. Herein, we found that CCT6A was highly expressed in type 2 alveolar epithelial cells (AEC2s) of fibrotic lung tissues and correlated with disease severity. Lactate increases the accumulation of lipid droplets in epithelial cells. CCT6A inhibits lipid synthesis by blocking the production of lactate in AEC2s and alleviates bleomycin-induced pulmonary fibrosis in mice. In addition, our results revealed that CCT6A blocks HIF-1α-mediated lactate production by driving the VHL-dependent ubiquitination and degradation of HIF-1α and further inhibits lipid accumulation in fibrotic lungs. In conclusion, we propose that there is a pivotal regulatory role of CCT6A in lactate metabolism in pulmonary fibrosis, and strategies aimed at targeting these key molecules could represent potential therapeutic approaches for pulmonary fibrosis.
特发性肺纤维化(IPF)是一种致命的进行性肺纤维化疾病。IPF 的发展涉及不同的分子和细胞过程,最近的研究表明,乳酸在促进疾病进展方面起着重要作用。然而,乳酸代谢的调节机制及其下游效应尚不清楚。分子伴侣 CCT6A 在多种生物学过程中发挥多种功能。我们的研究已经确定了 CCT6A 与 IPF 患者血清乳酸水平之间的潜在关联。在这里,我们发现 CCT6A 在纤维化肺组织的 2 型肺泡上皮细胞(AEC2)中高度表达,并与疾病严重程度相关。乳酸会增加上皮细胞中脂滴的积累。CCT6A 通过阻断 AEC2 中乳酸的产生来抑制脂质合成,并减轻博来霉素诱导的小鼠肺纤维化。此外,我们的结果表明,CCT6A 通过驱动 VHL 依赖性 HIF-1α 的泛素化和降解来阻止 HIF-1α 介导的乳酸生成,从而进一步抑制纤维化肺中的脂质积累。总之,我们提出 CCT6A 在肺纤维化中的乳酸代谢中起着关键的调节作用,针对这些关键分子的策略可能代表肺纤维化的潜在治疗方法。