Chemerin in Pulmonary Fibrosis: Advances in Mechanistic and Fundamental Research.

Pulmonary fibrosis is a progressive interstitial lung disease that involves stimulated growth of fibroblasts, over-deposition of extracellular matrix (ECM), and permanent damage of the lung structure. Among its various forms, idiopathic pulmonary fibrosis (IPF) is the most common and life-threatening type with few treatment options and a poor prognosis. Such obstacles highlight the urgency to find new molecular targets by better understanding the cellular and signaling processes that contribute to the pathogenesis of the disease. Chemerin is an adipokine and chemoattractant protein that has recently come into the limelight as a major controller of immune cell trafficking, inflammation, and tissue remodeling. Its biological activity is mainly mediated by binding to its receptors Chemokine-like receptor 1 (CMKLR1), G protein-coupled receptor 1 (GPR1), and C-C chemokine receptor-like 2 (CCRL2), and has been linked to numerous pathological conditions, such as metabolic diseases, cancer, and inflammatory diseases. Emerging data now indicate that chemerin can also be a key factor in the initiation and progression of pulmonary fibrosis. The aim of the review is to overview the existing evidence regarding regulatory processes of chemerin expression, signaling pathways, and effects of this protein in cells in the fibrotic lung microenvironment. Moreover, we will comment on the findings of in vitro and in vivo experiments supporting the possibility of chemerin as a promising molecular target in basic research on pulmonary fibrosis.