miR-142-5p and miR-130a-3p are regulated by IL-4 and IL-13 and control profibrogenic macrophage program

Macrophages play a pivotal role in tissue fibrogenesis, which underlies the pathogenesis of many end-stage chronic inflammatory diseases. MicroRNAs are key regulators of immune cell functions, but their roles in macrophage’s fibrogenesis have not been characterized. Here we show that IL-4 and IL-13 induce miR-142-5p and downregulate miR-130a-3p in macrophages; these changes sustain the profibrogenic effect of macrophages. In vitro , miR-142-5p mimic prolongs STAT6 phosphorylation by targeting its negative regulator, SOCS1. Blocking miR-130a relieves its inhibition of PPARγ, which coordinates STAT6 signalling. In vivo , inhibiting miR-142-5p and increasing miR-130a-3p expression with locked nucleic acid-modified oligonucleotides inhibits CCL 4 -induced liver fibrosis and bleomycin-induced lung fibrosis in mice. Furthermore, macrophages from the tissue samples of patients with liver cirrhosis and idiopathic pulmonary fibrosis display increased miR-142-5p and decreased miR-130a-3p expression. Therefore, miR-142-5p and miR-130a-3p regulate macrophage profibrogenic gene expression in chronic inflammation. Fibroblast activity is regulated by tissue macrophages. Here the authors show that two miRNAs regulated by IL-4 and IL-13 in macrophages target SOCS1 and PPARγ and modulate profibrogenic macrophage program in vitro and in vivo , and that alterations of these miRNAs are found in fibrosis.