ACTA1 and very late antigen-5 (VLA5) production in stromal progenitor derived myofibroblasts. Fibroblasts were collected, permeabilized, and ACTA1 or VLA5 and VLA6 presence was tested. Representative flow cytometry histograms depicting percentage of ACTA1 protein expression in fibroblasts derived from anchorage-independent cells (A) and primary lung cultures (B). Untreated (light gray), isotype (dark gray), and ACTA1-treated (black) cell populations are shown. Percentage of ACTA1-positive cells is also shown. Insets: Respective forward scatter vs. side scatter plots. (C): Cellular localization of ITGA5, ITGA6, and ITGB1 subunits in SPC-derived fibroblasts as seen by immunofluorescence. Top (from left to right): DAPI nuclear stain (blue), ITGB1 (green), ITGA6 (red), and Merge. Bottom (from left to right): DAPI nuclear stain (blue), ITGB1 (green), ITGA5 (red), and Merge. ITGA5 localization predominantly corresponds to that of ITGB1 to form VLA5 (yellow) focal adhesions in fibroblastic cells. Scale bars = 20 μm. Abbreviations: 488, Alexa Fluor 488; ACTA1, α smooth muscle actin type 1; DAPI, 4′6-diamidino-2-phenylindole; ITGA5, integrin α-5; ITGA6, integrin α-6; ITGB1, integrin β-1.