# Histone Lactylation Couples FSH-Driven Lactate Metabolism to Mitochondrial Biogenesis by Enhancing HDAC4-Mediated Deacetylation of PGC-1α in Granulosa Cells

## TL;DR

This study reveals how lactate metabolism, controlled by FSH, influences mitochondrial development in ovarian cells through epigenetic changes.

## Contribution

The study identifies a novel metabolic-epigenetic pathway involving histone lactylation that connects FSH-driven glycolysis to mitochondrial biogenesis.

## Key findings

- FSH increases lactate levels, leading to histone H4 lactylation (H4K5la) via P300/CBP.
- H4K5la enhances HDAC4 expression, which deacetylates PGC-1α to promote mitochondrial biogenesis.
- Disrupting the H4K5la/HDAC4/PGC-1α pathway impairs follicular development and mitochondrial function in mice.

## Abstract

Follicle-stimulating hormone (FSH) coordinates ovarian follicle development by aligning mitochondrial biogenesis with increased metabolic demand. Although FSH is known to stimulate glycolysis in granulosa cells (GCs), the mechanism by which glycolytic flux coupled to mitochondrial biogenesis remains unclear. Here, we demonstrate that histone lactylation functions as a lactate-sensitive epigenetic mediator linking FSH-driven metabolic alterations to mitochondrial biogenesis in GCs. Mechanistically, FSH increases intracellular lactate levels through glycolytic activation, thereby promoting P300/CBP-dependent lactylation of histone H4 at lysine 5 (H4K5la). H4K5la directly enhances HDAC4 expression, and HDAC4 subsequently deacetylates PGC-1α at lysine residues 329/330. Deacetylated PGC-1α cooperates with nuclear respiratory factors NRF1/2 to drive transcription of key mitochondrial regulators (TFAM, TFB1M, TFB2M), ultimately promoting mitochondrial biogenesis. Disruption of the H4K5la/HDAC4/PGC-1α axis markedly impaired mitochondrial biogenesis and follicular development, evidenced by reduced ovarian weight, smaller follicle size, decreased antral follicle number, and impaired GC proliferation and estradiol (E2) production in FSH-treated mice. These findings identify a metabolic–epigenetic regulatory pathway in which histone lactylation links glycolysis to mitochondrial adaptation, providing mechanistic insight into FSH-dependent reproductive physiology.