ABSTRACT
Objective To evaluate the effect of latanoprost on cell proliferation of and melanogenesis in human epidermal melanocytes,and to explore its mechanism.Methods Latanoprost was added into the 254 medium to prepare latanoprost solutions at different concentrations of 10-5,10-6 and 10-7 mol/L.In vitro cultured human epidermal melanocytes were divided into 4 groups to be cultured with media containing no latanoprost (control group) or 10-5,10-6 and 10-7 mol/L latanoprost for 48 hours.Cell counting kit-8 (CCK8) assay was performed to evaluate the proliferative activity of melanocytes,dopa oxidation assay to estimate the activity of tyrosinase.Sodium hydroxide (NaOH)-lysis method was used to determine the content of melanin,and Masson-Fontana staining to observe the number and distribution of melanin granules.Westernblot analysis and real-time fluorescence-based quantitative PCR were performed to determine the protein and mRNA expression of melanogenesis-related genes including microphthalmia-associated transcription factor (MITF),tyrosinase (TYR) and tyrosinase-related protein 1 (TYRP1).Comparison among the 4 groups and multiple comparisons were done by using one-way analysis of variance and least significant difference (LSD)-t test.Results Compared with the control group,the 10-6-,10-5-mol/L latanoprost groups showed significantly increased proliferative activity of melanocytes (1.064 ± 0.172 and 1.078 ± 0.080 vs.0.784 ± 0.015;t =3.289,3.454 respectively,both P ＜ 0.05),increased activity of tyrosinase (0.510 ± 0.017 and 0.454 ± 0.009 vs.0.355 ± 0.041;t =6.139,3.939 respectively,P ＜ 0.01 or 0.05),and increased content of melanin (t =7.232,5.967,both P ＜ 0.01).However,there were no significant differences in the proliferative activity of melanocytes,activity of tyrosinase or content of melanin between the 10-7-mol/L latanoprost group and control group (all P ＞ 0.05).Masson-Fontana staining showed more and darker melanin granules on melanocyte dendrites in the 10-5-,10-6-,10-7-mol/L latanoprost groups than in the control group,and the color of melanin granules changed from light brown to black brown along with the increase in the concentration of latanoprost.The mRNA expression of MITF increased along with the increase in the concentration of latanoprost (P ＜ 0.01),and the protein expression of MITF wassignificantly higher in the 10-6,10-5-mol/L latanoprost groups than in the control group and 10-7-mol/L latanoprost group (all P ＜ 0.01).The 10-6-mol/L latanoprost group showed significantly increased mRNA and protein expression of TYR and TYRP1 compared with the control group,10-7-,10-5-mol/L latanoprost groups (all P ＜ 0.01).Conclusion Latanoprost can increase the proliferation of human epidermal melanocytes,and promote tyrosinase activity and melanogenesis likely by enhancing the mRNA and protein expression of MITF,TYR,TYRP1.
ABSTRACT
Objective To determine the expression of nucleobindin 2-encoded satiety and fatinfluencing protein-1 (nesfatin-1) and interleukin (IL)-26 in the serum of patients with vitiligo,and to explore the relationship of nesfatin-1 and IL-26 with anxiety status,disease stage and distribution pattern of vitiligo lesions.Methods From March 2017 to September 2018,123 outpatients with vitiligo,as well as 30 healthy controls (control group),were enrolled from Department of Dermatology,Affiliated Hospital of Jiangsu University.Of these patients,93 rated as anxious (vitiligo with anxiety group),and 30 as nonanxious (vitiligo without anxiety group).Another 30 anxious patients with other autoimmune diseases and background diseases like hypertension and diabetes mellitus but not vitiligo (anxiety group) were enrolled from Zhenjiang Fifth People's Hospital.Enzyme-linked immunosorbent assay (ELISA) was performed to detect levels of nesfatin-1 and IL-26 in the above groups,and state-trait anxiety inventory (STAI) was used to evaluate the anxiety status.According to the vitiligo disease activity (VIDA) score,the vitiligo patients with anxiety were divided into 3 subgroups:stable stage group,active stage group and rapid progressive stage group.According to the distribution pattern of skin lesions,the vitiligo patients with anxiety were divided into 5 subgroups:localized vitiligo group,segmental vitiligo group,generalized vitiligo group,sporadic vitiligo group and acral vitiligo group.The levels of nesfatin-1 and IL-26 were compared among different stage groups and type groups.Statistical analysis was carried out using one-way analysis of variance for comparison among several groups,multi-way analysis of variance and stratification analysis for multifactor data,paired t-test for comparison before and after treatment,and Pearson correlation analysis for analyzing correlations.Results The serum level of nesfatin-1 significantly differed among the vitiligo with anxiety group,vitiligo without anxiety group,anxiety group and control group (F =10.78,P ＜ 0.001),and was significantly higher in the vitiligo with anxiety group than in the other 3 groups (P ＜ 0.001).No significant difference in the serum level of IL-26 was found among the 4 above groups (F =1.34,P =0.26).As pearson correlation analysis showed,the serum level of nesfatin-1 was positively correlated with the STAI score in the 93 vitiligo patients with anxiety (r =0.55,P ＜ 0.001).The serum level of nesfatin-1 was significantly higher in the rapid progressive stage group than in the stable stage group (P ＜ 0.05),while there was no significant difference in the IL-26 level among different stage groups (P ＞ 0.05).The generalized vitiligo patients with anxiety showed significantly increased serum level of nesfatin-1 compared with the localized vitiligo patients with anxiety (P ＜ 0.001).After 3-month treatment,the nesfatin-1 level in the 10 vitiligo patients with anxiety significantly decreased compared with that before the treatment (paired t =4.40,P =0.02),but the STAI score did not change (P ＞ 0.05).Conclusion Nesfatin-1 as an emotioninfluencing factor may participate in the occurrence of vitiligo,especially affect patients with rapid progressive vitiligo or generalized vitiligo,while IL-26 may be irrelevant to vitiligo.