Abstract
Dermal papilla cells (DPCs) tend to aggregate both in vitro and in vivo, which increases the hair inductivity of DPCs. However, the underlying mechanism of spheroid formation is unknown. We investigated whether collagen expression in human DPCs (hDPCs) is involved in the spheroid formation and hair inductivity of hDPCs and further examined the underlying molecular mechanism of collagen upregulation. The expression of diverse collagens, such as COL13A1 and COL15A1, was upregulated in three dimensional (3D)-cultured or intact DPCs, compared to 2D-cultured hDPCs. This collagen expression was a downregulated in aged hair follicle, and aged DPCs were difficult to aggregate. Blocking of COL13A1 and COL15A1 by small interfering RNA reduced aggregation, while induced senescence of hDPCs in vitro. Further, transforming growth factor-β2 (TGF-β2) expression decreases with aging, and is involved in regulating the expression of COL13A1 and COL15A1. Addition of recombinant TGF-β2 delayed cellular senescence, and recovered spheroid formation in aged hDPCs by upregulating collagen levels. On the contrary, knock-out of TGF-β2 induced the aging of DPCs, and inhibited spheroid formation. These results suggested that COL13A1 and COL15A1 expression is downregulated with aging in DPCs, and upregulation of collagen by TGF-β2 induces the spheroid formation of DPCs. Therefore, TGF-β2 supplement in DPC culture medium could enhance the maintenance and hair inductivity of DPCs.
Highlights
Hair follicle (HF) is composed of epidermal and dermal compartments, and their interaction plays an important role in HF morphogenesis and growth [1, 2]
Global gene expression profiles and functional analyses revealed the upregulation of collagen gene in Human DPCs (hDPCs) aggregation culture hDPCs gradually lose their proliferative capability and hair inductivity after passage in vitro [5, 24]
This study was investigated whether collagen expression changes in hDPCs are involved in the spheroid formation and hair inductivity of hDPCs and further examined the underlying molecular mechanism of collagen regulation
Summary
Hair follicle (HF) is composed of epidermal and dermal compartments, and their interaction plays an important role in HF morphogenesis and growth [1, 2]. The dermal papilla (DP), located at the base of the HF, is a unique tissue surrounded by epithelial matrix cells and is essential in controlling hair growth, formation, and cycling. Human DPCs (hDPCs) exhibit hair inductivity in the early passage and their hair inductivity is declined dramatically during aging. Microenvironmental reprogramming by three-dimensional (3D) culture enables hDPCs to induce de novo human HF growth [5]. The tendency to aggregate is a significant characteristic of DPCs, and the ability to aggregate and hair inductivity are reduced after several passages of culture [1, 6]. The loss of the extracellular matrix (ECM) during culture could be responsible for the gradual loss of www.aging-us.com
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
