Effects of adipose derived mesenchymal stem cells in the treatment of immune alopecia and related mechanism

Objective To investigate the effect of adipose derived mesenchymal stem cells (ADSCs) on immune alopecia. Methods Human ADSCs and hair follicle dermal papilla cells (DPCs) were co-cultured in Transwell chambers (0.4 μm). The proliferation of DPCs after co-culture was observed by CCK-8 assay, and the induction ability of DPCs was detected by real-time fluorescence PCR. Furthermore, 40 male C57BL/6 mice were randomly divided into four groups: a blank control group, an immune alopecia group, an adipose stem cell treatment group, and a glucocorticoid treatment group. An immune alopecia model of mice was established to observe the changes of skin color and the growth of new hair in the depilation area of mice in each group. The length and quality of new hair in each group were calculated. The number and morphological differences of hair follicles in each group were observed by H-E staining. The levels of inflammatory cytokines intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1) and immune cytokines CD4⁺ and CD8⁺ around hair follicles were observed by immunohistochemistry. Results The results showed that ADSCs effectively promoted the proliferation ability of DPCs (P<0.01), enhance the secretion function of DPCs (P<0.01), strengthen the ability of DPCs to induce hair follicle formation, and promote hair follicle into the growth phase. In the mouse model of immune alopecia, injection of ADSCs increased hair mass (P<0.05) and improved hair growth (P<0.05). According to H-E staining and immunohistochemistry, ADSCs down-regulated the immune function around the hair follicle and reduced the level of local inflammatory factors. Conclusions Local injection of ADSCs can treat immune alopecia, which may be related to regulating local immune microenvironment and inhibiting the damage of inflammatory factors to hair follicles. It is suggested that local application of ADSCs may be a new thought for the treatment of refractory immune alopecia.