Autophagy In Melanocytes From Patients With Vitiligo Exhibits Distinct Molecular Mechanism And Is Correlated With Different Clinical Pattern

Background Vitiligo is an acquired, idiopathic depigmented disease. The factors involved in vitiligo are very complex, and the pathogenesis is also unclear, which may involve genetic, autoimmune and cytotoxic etc. However, the common pathological feature of vitiligo is disappeared of the melansomes in the depigmented area, which is due to the deficiency of melaocytes in the epidermal basal layer and hair follicles, or the dysfunction of melanin generation. we try to find out the etiology and pathogenesis of vitiligo. Autophagy plays a very important role in melanin generation. We speculate that the pathogenesis correlates with autophagy. The objective of this project is to make the melaocytes autophagy to study the role of autophagy in vitiligo.Objective Autophagy and functional molecules expression in melanocytes from patients with vitiligo are investigated, and also correlation with clinical pattern of vitiligo is analyzed.Methods The epidermal melanocytes from patients with 9 cases of segmental vitiligo(SV), 11 cases of generalized vitiligo(GV), and 6 healthy individual(HI) were obtained from normal skin and incubated in vitro. The autophagy was induced by rapamycine and observed by transmission electron microscopy and fluorescence microscopy. The LC3Ⅱand MITF,TYR, TYRP1, and TYRP2 were detected by Western blot.Results The autophagy was found in melanocytes from SV patients and HI but not GV before rapamycine treatment. The quantity of autophagysome and the LC3 Ⅱprotein expression were increased in melanocytes from SV, GV and HI after autophagy induction. The autophagy intensity in melanocytes from patients with GV increased significantly more than that of SV and HI(P<0.05). Compared with HI, the MITF, TYR,TYRP1, and TYRP2 protein showed lower expression both in GV and SV. Followed by autophagy induction in malnocytes from all three groups, the MITF, TYR, and TYRP1 protein expression obviously increased except TYRP2.Conclusion Autophagy may be involved in the pathogenesis of vitiligo through effecting functional molecules in melanocytes and is correlated with clinical pattern of vitiligo.