Hdac11 promotes idiopathic pulmonary fibrosis through macrophage M2-type polarization and myofibroblast accumulation by inhibiting Parkin-dependent mitophagy.

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease where macrophages drive fibrogenesis, yet Hdac11's role is unclear. We first identify pronounced Hdac11 upregulation in IPF lungs, which is associated with an enrichment in alveolar macrophages (AMs). Genetic ablation of Hdac11 or adoptive transfer of Hdac11-deficient macrophages markedly attenuates fibrosis. Specifically, Hdac11 deficiency significantly reduces M2 macrophage polarization in vivo and vitro and is associated with reduced macrophage-myofibroblast transition (MMT) like phenotypic reprogramming, thereby decreasing myofibroblast accumulation and profibrotic gene expression. Mechanistically, impaired mitophagy mediates Hdac11-mediated M2 macrophage polarization and is associated with MMT-like changes. Hdac11 regulates mitochondrial quality control by deacetylating Parkin at lysine 76, promoting its ubiquitination and degradation, which impairs mitophagy and drives profibrotic macrophage activation. Pharmacological Hdac11 inhibition effectively reverses bleomycin-induced fibrosis. Taken together, our work identifies Hdac11 as a target of Parkin-mediated mitophagy in macrophages, establishing Hdac11-Parkin axis disruption as an important mechanism in IPF and highlighting Hdac11 inhibition as a potential therapeutic strategy.