Progesterone activates histone lactylation-Hif1α-glycolysis feedback loop to promote decidualization.

Decidualization is a progesterone-dependent cellular differentiation process that is essential for establishing pregnancy. Robust activation of glycolysis and lactate synthesis during decidualization is remarkable, but their developmental functions remain largely unknown. Herein, we identify that endometrial lactate production plays a critical role in establishing local histone lactylation, a newly identified histone modification, and is important for ensuring normal decidualization. Enhanced endometrial glycolysis is the hallmark metabolic change and is tightly coupled with H4K12la during decidualization. Inhibition of histone lactylation impaired decidualization, in either physiological conception or in vivo and in vitro induced decidualization models. Mechanistic study based on CUT&Tag and ATAC-seq revealed that a transcriptional factor hypoxia-inducible factor 1 α (Hif1α) is the critical regulatory target of H4K12la, and in turn forms a H4K12la-Hif1α-glycolysis feedback loop to drive decidualization. Moreover, we demonstrate that the loop is directly activated by progesterone during decidualization. Together, our study not only advance the current knowledge of the role of lactate in regulating uterine function, but also establish a novel functional link among the major endocrine factor, endometrial metabolic change and epigenetic modification during endometrial remodeling. These findings present valuable clues to develop clinical intervention strategies to improve pregnancy outcomes following both natural conception and assisted reproduction.