Ubiquitin-specific peptidase 10 attenuates bleomycin-induced pulmonary fibrosis via modulating autophagy depending on sirtuin 6-mediated AKT/mTOR.

Idiopathic pulmonary fibrosis (IPF), characterized by fibroblast activation and collagen deposition, is a progressive lung disease that lacks effective interventions. Ubiquitin-specific peptidase 10 (USP10) acts as a multifunctional player in inflammatory response and progression of cancers, the effect on pulmonary fibrosis is unknown. Here, we demonstrated downregulated expression of USP10 in fibrotic lung tissues of IPF patients. In the current study, lung tissues were collected at the end of weeks 1, 2, or 3 post bleomycin (BLM)-intratracheal delivery. Consistently, USP10 expression levels were reduced after BLM challenge in a time-dependent manner. Mice treated with lentivirus overexpressing USP10 exhibited mitigative lung injury and reduced collagen deposition. USP10 overexpression enhanced autophagy in BLM-treated mouse lungs. Interestingly, the protective effect of USP10 was attenuated as the pulmonary autophagy flux was blocked by autophagy inhibitor 3-methyladenine (3-MA). Primary human and mouse lung fibroblasts were treated with pro-fibrotic TGF-β1 to verify the role of USP10 in vitro. Mechanically, the deubiquitinating enzyme USP10 interacted with Sirtuin 6 (Sirt6) and inhibited its degradation. Furthermore, USP10 overexpression inhibited the activation of Sirt6-mediated AKT/mTOR pathway in both lung tissues and fibroblasts. Our findings suggest that USP10 might attenuate pulmonary fibrosis through the promotion of Sirt6/AKT/mTOR-mediated autophagy. These data prioritize USP10 as a therapeutic target for treating IPF.