[Primary study on the culture of human fetal follicle bulge cells and their differentiation into sebaceous gland].

Objective: To develop a rapid and reproducible method for the culture of human fetal hair follicle bulge cells, and observe the plasticity of its differentiation into sebaceous gland in vitro.

Methods: The bulge cells isolated from fetal human hair follicles by enzymatic digestion (digestion method) and manual microdissection (conventional method) were cultured and passaged respectively, the efficiency and biological features of cells were investigated , the clone forming efficiency was assayed by MTT, and the expression of K19 was further compared by immunocytochemistry (ABC). The morphological change and the expression of EMA of bulge cells were also observed after induction.

Results: By conventional method, 8-10 bulges were harvested in one hour, 40%-50% of their cells were found to adhere to the culture plate after culturing for 48h, and they became confluent after 14 days. In comparison, about 100 bulges were harvested in one hour by digestion method, the adherence efficiency of their cells was 30% after cultivation for 12h and became confluent after 7 days. The cells grew larger with time, with irregular shape and droplets of lipid around the nucleus. The clone forming efficiency of bulge cells cultured by digestion method was (18.2 +/- 2.1) %, which was much higher than that of cells obtained by conventional method[ (12.7 +/- 3.4) %, P < 0.05]. Immunocytochemistry staining showed that positive staining of K19 was observed in most of the bulge cells, with a large amount of brown granules in the cytoplasm.

Conclusion: Human hair follicle bulge cells can be efficiently cultured and multiplied in vitro, and they retained the characteristics of stem cells. And they have the potential to differentiate into sebaceous glands by induction in vitro.