Effects of Murine Dermal Cells on the Regulation of Hair Growth Is Dependent on the Cell Number and Post-Natal Age of Newborn Mice

Abstract

Dermal cells from neonatal mice can initiate the formation of hair follicles (HFs) when combined with adult mouse epidermal cells and transplanted subcutaneously into athymic mice. In the present study, the effects of dermal cells on HF formation were tested in terms of total cell number and the time course of cell harvest. Results demonstrated that the number of dermal cells is critical to the formation of HF. Furthermore, hair forming ability is rapidly decreasing as the neonatal mice age. To examine potential differences in gene expression, cDNA array was performed. Results demonstrate that numerous molecules which are directly involved in receptor and signaling correlated with decreased hair inductivity in early time points after delivery. It is reported that bone morphogenic protein (BMP)-6 and Wnt3a treatment increased hair inductivity of dermal papilla cells. But in our study, no changes were observed in the expression levels of BMP-6 and Wnt3a. However, several Wnt related genes demonstrate increased or decreased expression levels. Thus, our results suggest that co-ordinated regulation of these molecules will be important in hair neogenesis within our model system.

Poor Capability of 3D-Cultured Adipose-Derived Stem Cells to Induce Hair Follicles in Contrast to 3D-Cultured Dermal Papilla Cells

“…Seeded plates were incubated at 37℃ in a humidified atmosphere with 5% CO 2 for 24~48 h until they were used for implantation. Hair-inductive capacity of human DP and ADSC spheres was assessed as described previously 4 10 . Three weeks later, skin samples were excised from the mice and examined to verify hair induction.…”

Characteristics of the Skin of the Female Albino Rats in Different Ages:Histological, Morphometric and Electron Microscopic Study

“…A negative linear effect of the age on the number of hair follicles was observed in the current study (R 2 =0.60, P=0.000), so 60% of the reduction number of hair follicles could be explained by the effect of ageing process. The decreased formation of the hair follicles was secondary to the decreased number of dermal cells as the number of dermal cells is critical for the formation of the hair follicles [28]. Similarly, a decline in hair number, rate of growth, and diameter had been documented with progressive ageing in human [21].…”