Abstract:

Objective·To investigate whether there are epithelial stem cells, melanocyte stem cells, and autofluorescence in the bulge region of hair follicles. Methods·Samples were collected from the posterior occipital and temporal whole layer scalp of healthy volunteers with complete separation of hair follicles. Autofluorescence in hair follicles was observed using fluorescence microscope. Expressions of hair follicle keratins K15 and K19 were measured using indirect immunofluorescence and immunohistochemistry. RT-PCR was used to measure the mRNA expression levels of epithelial stem cell and melanocyte stem cell markers Dct, K15, and K19 and mature cell markers Tyrase, Tyrp1,MITF-M, and MC1R in hair bulbs and bulge region. Results·Autofluorescence was observed in the bulge region of hair follicles. Immunofluorescence and immunohistochemistry showed K15 and K19 were expressed in bulge region. RT-PCR showed that the mRNA expressions of Dct and K15 in bulge region were significantly higher than those in hair bulbs. The mRNA expression of K19 in bulge region was not significantly different from that in hair bulbs, while the mRNA expressions of Tyrase, Tyrp1, MITF-M, and MC1R in bulge region were significantly lower than those in hair bulbs. Conclusion·Autofluorescence can be observed and epithelial stem cells and melanocyte stem cells exist in the bulge region of hair follicles.

Key words: hair follicles bulge region, epithelial stem cell, melanocyte stem cell, autofluorescence