ABSTRACT
Objective To investigate the effect of calcipotriol on melanin synthesis by human melanocytes and its possible action mechanism.Methods Primary melanocytes were cultured with various concentrations(10~(-5),10~(-6),10~(-7),10~(-8),10~(-9),10~(-10) mol/L)of calcipotriol for 24 or 48 hours.Subsequently,MTT assay,NaoH assay.Dopa-oxidase assay,Western blot and semiquantitative RT-PCR were used to measure the cell proliferation of,melanin synthesis by.tyrosinase activity,protein and mRNA expression levels in the melanocytes.respectively.Those untreated melanocytes served as the control.Results The calcipotriol between 10~(-9) and 10~(-5) mol/L had no significant effect on the proliferation of cultured melanocytes(P＞0.05).while that of 10~(-9) and 10~(-8) mol/L increased tyrosinase activity by 137%and 123%,and enhanced melanin synthesis by 40.63%and 18.75%,respectively,compamd with untreated melanocytes(both P＜0.05).Moreover,the tyrosinase protein level increased by 270.4%(P＜0.05)in melanocytes treated with calcipotriol at 10~(-9) mol/L for 24 hours.The strongest tyrosinase activity and melanin synthesis was observed in melanocytes treated with calcipotriol of 10~(-9) moI/L.Conclusions The proliferation of melanocytes is unaffected by calcipotriol at 10~(-9) to 10~(-5) mol/L,but it can elevate the expression of tyrosinase protein,enhance tyrosinase activity,and promote melanin synthesis in melanocytes.
ABSTRACT
Objective To investigate the association of HLA class Ⅱ genes and vitiligo in the eastern China Han nationality. Methods Ninety-eight patients with vitiligo and 150 healthy controls were studied for HLA-DRB1, DQA1 and DQB1 locus alleles by PCR-SSOP typing. Results The frequency of HLA-DQA1*03 increased significantly (Pc = 0.008) and DQA1*05 decreased significantly (Pc = 0.016) in the patients with vitiligo. Conclusions The results suggest that there exists a correlation between HLA class Ⅱ genes and vitiligo, and DQA1*03 allele may be a susceptible gene or have a close linkage with susceptible genes, while DQA1*05 allele may be a protective gene in the eastern China Han nationality.