title: Assay to evaluate BAL Fluid regulation of Fibroblast α-SMA Expression.
abstract: Because transforming growth factor-β (TGF-β1) induces differentiation of fibroblasts to myofibroblasts, we developed a protocol to evaluate alveolar macrophage-derived TGF-β1 regulation of lung fibroblast differentiation (Larson-Caseyet al., 2016). The protocol allows evaluating the ability of mouse bronchoalveolar lavage (BAL) fluid to alter fibroblast differentiation. Fibroblast differentiation was measured by the expression of α-smooth muscle actin (α-SMA).
  
  
  BACKGROUND
  Alveolar macrophages play an integral role in pulmonary fibrosis development by increasing the expression of TGF-β1 (Heet al., 2011). Our prior data demonstrate that alveolar macrophages are a critical source of TGF-β1 as mice harboring a conditional deletion of TGF-β1 in macrophages were protected from pulmonary fibrosis (Larson-Caseyet al., 2016). The expression of α-SMA is a defining feature of myofibroblasts, and TGF-β1 is a well-characterized pro-fibrotic mediator that induces transformation of fibroblasts to myofibroblasts bothin vitro(Desmoulièreet al., 1993) andin vivo(Simeet al., 1997). Prior studies exposed fibroblasts to recombinant TGF-β1 to show its effect on differentiation and function (Horowitzet al., 2007). Here we have developed a protocol for determining the ability of mouse BAL fluid to alter the differentiation of human lung fibroblasts to myofibroblasts, the cells that produce extracellular matrix proteins.
authors.affiliation: Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA 35294.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Larson-Casey
authors.affiliation: Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA 35294; Birmingham Veterans Administration Medical Center, Birmingham, AL, USA 35294.
authors.forename: A Brent
authors.initials: AB
authors.lastname: Carter