Figure 7.

CD44 is necessary for IPF MPC fibrogenicity in vivo. NSG mice were treated with intratracheal bleomycin (1.25 U/kg). Fourteen days later, the mice received IPF MPCs (IPF422) transduced with CD44 sh-RNA or scrambled shRNA. There were five mice/group. Lungs were harvested at the end of week 6. A: collagen content quantified was quantified in left lungs by the Sircol assay. Data are expressed as means ± SE. P value was determined by two-tailed Student’s t test. B–G: serial 4-µm sections of right lung tissue (B–E: scale bar = 500 µm; F and G: scale bar = 50 µm). Representative H&E (B and D) and trichrome stains (C and E) assessing fibrosis and collagen deposition, respectively. F and G: IHC using an antibody recognizing human procollagen to identify human cells and assess collagen synthesis. Shown are high-power views corresponding to the boxed regions in C and E. IPF, idiopathic pulmonary fibrosis; MPCs, mesenchymal progenitor cells.