The effect of different concentrations of all-trans retinoic acid on the growth and survival of mouse hair follicle stem cells

Hair follicle stem cells are multipotent, located in the bulge area, and are
highly proliferating. Retinoids have an effect on epidermal differentiation and keratinization. Retinoic acid
is used to treat some skin diseases such as Melasma, Acne and Ichthyosis. So, the study of all-trans retinoic
acid effect on hair follicle stem cells and determination of the effective concentration of retinoic acid on
hair follicle stem cell survival seems to be essential.
Materials and Methods: In this study, we isolated and cultured hair follicle stem cells derived from Balb/c
mice Whisker follicles. Then, the cells were treated with different concentrations of all-trans retinoic acid.
0.5 to 20 µM of all-trans retinoic acid was used to evaluate inhibitory or proliferative effects. MTT assay
was used to evaluate cytotoxicity of all-trans retinoic acid. To investigate cell death and survival, we used
acridine orange/ethidium bromide staining method. The results were analyzed by fluorescent microscopy.
Apoptotic and necrotic cell numbers were counted using Image J software.
Results: Results indicated that apoptotic, rather than necrotic, cell death was caused by 10µM and higher
concentrations of retinoic acid. The IC50 value determined by the dose response curve was found to be 14.3
µM.
Conclusion: Results of this study indicate that if hair follicle stem cells expose to high concentrations of
all-trans retinoic acid, the cells may undergo apoptotic or necrotic cell death Therefore, higher
concentrations of retinoic acid can be used to eliminate redundant hairs and low concentrations can be used
for the treatment of skin diseases