TGFB1 and acute respiratory distress syndrome: Moreover, MSCs can regulate tissue remodeling processes and attenuate the lung fibrosis by increasing metalloproteinase (MMP)-8 and decreasing the levels of tissue inhibitor of metalloproteinase (TIMP)-1, IL-1 β, and transforming growth factor-β1 (TGF-β1) in the animal model of ARDS (Maron-Gutierrez et al., 2013; Silva et al., 2018).