Abstract

Lactate has been recognized as a major fuel substrate and also a lactyl-group donor for histone lysine lactylation. Hepatocytes act as lactate-consuming cells owing the high oxidative capability especially during exercise, a primary nonpharmacological intervention for alleviating metabolic dysfunction-associated steatotic liver diseases including steatohepatitis (MASLD/MASH). However, little is known regarding how lactate links the metabolic–epigenetic axis in hepatocytes. Here we show that declined estrogen-related receptor α (ESRRA) expression occur in MASLD/MASH accompanied with elevated levels of lactate and histone lactylation, particularly H3K18la. Such dysregulation can be partially rescued by chronic exercise in aged mice or exacerbated by genetic ablation of hepatocyte ESRRA. Mechanistically, exercise-induced ESRRA/PPARGC1A facilitates lactate consumption through transcriptional regulation of lactate dehydrogenase B and glucose-6-phosphatase catalytic subunit 1, rewiring lactate from a lactyl donor to gluconeogenic precursor in hepatocytes. Hepatocyte-specific ESRRA overexpression counteracts MASLD/MASH progression in mice, rectifying aberrant H3K18la accumulation and its marked gene transcripts that are involved in liver pathology. Our findings reveal that ESRRA functions as an exercise executor linking metabolism with epigenetic modification, highlighting a gluconeogenic–epigenetic regulatory axis that could be fine-tuned to mitigate risk factors of MASLD/MASH such as aging, menopause, a sedentary lifestyle and malnutrition. The alternative text for this image may have been generated using AI.