Human hair follicle stem cell differentiation into contractile smooth muscle cells is induced by transforming growth factor-β1 and platelet-derived growth factor BB.

Smooth muscle cells (SMCs) are important in vascular homeostasis and disease and thus, are critical elements in vascular tissue engineering. Although adult SMCs have been used as seed cells, such mature differentiated cells suffer from limited proliferation potential and cultural senescence, particularly when originating from older donors. By comparison, human hair follicle stem cells (hHFSCs) are a reliable source of stem cells with multi-differentiation potential. The aim of the present study, was to develop an efficient strategy to derive functional SMCs from hHFSCs. hHFSCs were obtained from scalp tissues of healthy adult patients undergoing cosmetic plastic surgery. The hHFSCs were expanded to passage 2 and induced by the administration of transforming growth factor-β1 (TGF-β1) and platelet-derived growth factor BB (PDGF-BB) in combination with culture medium. Expression levels of SMC-related markers, including α-smooth muscle actin (α-SMA), α-calponin and smooth muscle myosin heavy chain (SM-MHC), were detected by immunofluorescence staining, flow cytometry analysis and reverse transcription-polymerase chain reaction (RT-PCR). When exposed to differentiation medium, hHFSCs expressed early, mid and late markers (α-SMA, α-calponin and SM-MHC, respectively) that were similar to the markers expressed by human umbilical artery SMCs. Notably, when entrapped inside a collagen matrix lattice, these SM differentiated cells showed a contractile function. Therefore, the present study developed an efficient strategy for differentiating hHFSCs into contractile SMCs by stimulation with TGF-β1 and PDGF-BB. The high yield of derivation suggests that this strategy facilitates the acquisition of the large numbers of cells that are required for blood vessel engineering and the study of vascular disease pathophysiology.