Human Caesarean scar-derived feeder cells: a novel feeder cell type for culturing human pluripotent stem cells without exogenous basic fibroblast growth factor supplementation

In a feeder-dependent culture system of human pluripotent stem cells (hPSCs), coculture with mouse embryonic fibroblasts may limit the clinical use of hPSCs. The aim of this study was to determine the feasibility of using human Caesarean scar fibroblasts (HSFs) as feeder cells for the culture of hPSCs. HSFs were isolated and characterised and cocultured with hPSCs, and the pluripotency, differentiation ability and karyotypic stability of hPSCs were determined. Inactivated HSFs expressed genes (including inhibin subunit beta A (INHBA), bone morphogenetic protein 4 (BMP4), fibroblast growth factor 2 (FGF2), transforming growth factor-beta 1 (TGFB1), collagen alpha-1(I) (COL1A1) and fibronectin-1 (FN1) that have been implicated in the maintenance of hPSC pluripotency. When HSFs were used as feeder cells, the pluripotency and karyotypic stability of hPSC lines did not change after prolonged coculture. Interestingly, exogenous FGF2 could be omitted from the culture medium when HSFs were used as feeder cells for hESCs but not hiPSCs. hESCs cocultured with HSF feeder cells in medium without FGF2 supplementation maintained their pluripotency (as confirmed by the expression of pluripotency markers and genes), differentiated in vitro into embryonic germ layers and maintained their normal karyotype. The present study demonstrates that HSFs are a novel feeder cell type for culturing hPSCs and that supplementation of exogenous FGF2 is not necessary for the Chula2.hES line.