Collagen fiber and transforming growth factor beta. Collagen fiber content in alveolar septa and transforming growth factor beta (TGF-β) mRNA and protein levels in lung tissue after lipopolysaccharide (LPS)-induced and cecal ligation and puncture (CLP)-induced acute respiratory distress syndrome (ARDS). Values are mean ± standard deviation of four to six animals per group. *Significantly different from corresponding control group (C or sham) (P <0.05). #ARDS-BMDMC vs. ARDS-SAL (P < 0.05). BMDMC, bone marrow-derived mononuclear cell; SAL, saline.