Correlating functional heterogeneity of human dermal fibroblasts with differences in gene expression. Correlating functional heterogeneity of human dermal fibroblasts with differences in gene expression

Recent work has identified markers of fibroblast heterogeneity in human dermis. Transforming growth factor-β1 (TGF-β1) promotes fibroblast-to-myofibroblast differentiation, characterised by the expression of α-smooth muscle actin (α-SMA). Human dermal fibroblasts (hDF), treated with TGF-β1, were assayed for differentiation, proliferation and cell shape using the Operetta imaging system. One donor hDF, derived from female 64-year-old breast skin, expressed decreased levels of α-SMA protein. The gene expression profile of this donor hDF was determined using the Agilent microarray system. Four gene candidates (Asporin, ASPN; C-X-C motif chemokine ligand 1, CXCL1; Insulin-like growth factor 1, IGF1; and Wnt family member 4, WNT4) were chosen based on expression values and validated by TaqMan qPCR. Successful knockdown of IGF1 and WNT4 was achieved using MISSION shRNA-based lentiviral treatment. Fibroblast IGF1 knockdown (shIGF1) increased α-SMA mRNA and protein expression; no effect was seen with fibroblast WNT4 knockdown (shWNT4). Here I have characterised hDF phenotype and gene expression with regard to population heterogeneity. This work highlights the role of IGF-1 signalling on α-SMA expression and dermal fibroblast fate. Targeting IGF-1 signalling could provide therapeutic benefit for skin disorders involving aberrant wound healing and excessive fibrosis. Overall design: Enzyme-derived, human dermal fibroblasts from four adult donors. Treated with/without TGF-β1 for 12h/24h and used for Agilent one colour microarray.