A narrative review of the role of HDAC6 in idiopathic pulmonary fibrosis.

Background and Objective: Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible condition characterized by the deposition of extracellular matrix resulting from repetitive damage to the alveolar epithelium. These injuries, along with dysregulated wound repair and fibroblast dysfunction, lead to continuous tissue remodeling and fibrosis, eventually resulting in end-stage pulmonary fibrosis. Currently, there is no specific pharmacological treatment available for IPF. The role of inflammation in the development of IPF is still a topic of debate, and it is sometimes considered incidental to fibrosis. Over the past decade, macrophages have emerged as significant contributors to the pathogenesis of fibrosis. M1 macrophages are responsible for wound healing following alveolar epithelial injury, while M2 macrophages are involved in resolving wound repair and terminating the inflammatory response in the lungs. Various studies provide evidence that M2-like macrophages contribute to the abnormal fibrogenesis. In recent years, there has been growing interest in understanding macrophage polarization and its role in the development of pulmonary fibrosis. Histone deacetylase 6 (HDAC6), a member of the HDAC family with two functional deacetylase structural domains and a ubiquitin-binding zinc finger structural domain (ZnF-BUZ), plays a crucial role in pulmonary fibrosis. This article explores the role of HDAC6 in pulmonary fibrosis and evaluates its potential as a treatment approach for IPF. Methods: PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, China Biomedical Literature Service System (CBMdisc) and Web of Science were searched to obtain researches, published in English and Chinese, until July 2023. The search was performed using specific keywords such as Histone deacetylase 6, HDAC6, Idiopathic pulmonary fibrosis, IPF, fibrosis. Key Content and Findings: HDAC6 has diverse effects on physiological processes, including the NLRP3 inflammasome, epithelial-mesenchymal transition, the TGFβ-PI3K-AKT pathway, macrophage polarization and TGF-β-Smad signaling pathway, due to its unique structure. HDAC6 has been found to enhance the inflammatory response and fibrosis of lung tissues, contributing to the development of IPF. Conclusions: In the future, HDAC6 inhibitors are expected to play a crucial role in the treatment of fibrotic disorders and should be studied further deserves to pursue in future research.