Evaluation of a resoruf in-based fluorescent probe for tyrosinase detection in skin pigmentation disorders

Purpose Skin pigmentation disorders,such as vitiligo and melasma,are difficult to diagnose in the early stages,but abnor-mal tyrosinase levels and tyrosinase activity are potential indicators.Some resorufin-based fluorescence probes(RBFPs)have been designed to detect tyrosinase in tumors,but they have not been used in skin pigmentation disorders.In this study,one of these RBFPs(synthesized by resorufin salt coupled with 3-(bromomethyl)phenol)was evaluated comprehensively.Methods The RBFP was tested in different kinds of mouse and human skin cells,as well as in in vivo models,including zebrafish,guinea pigs,and Sprague-Dawley rats.In addition,small interfering RNAs(siRNAs),kojic acid,and 1-phenyl-2-thiourea(PTU)were used to inhibit tyrosinase levels or tyrosinase activity.Results This probe successfully detected tyrosinase and emitted red fluorescence in melanoma cells and melanocytes.Fluorescence was also observable in zebrafish and on the skin of guinea pigs when using the RBFP.In mouse and human cells,the RBFP showed good selectivity to tyrosinase.Moreover,in the case of decreased tyrosinase levels or activity caused by siRNAs,kojic acid,or PTU,the probe was sensitive to these changes.Further,the RBFP showed no toxic effects at concentrations of<20μmol/L,both in vitro and in vivo.Conclusions Our findings indicate the value and limitations of the RBFP in tyrosinase detection,but suggest the need for further improvement of fluorescent probes in the diagnosis of skin pigmentation disorders.

Evaluation of Serum Vitamin D Concentration and Blood Eosinophil and Basophil Counts in Patients With Vitiligo:A Cross-sectional Study From Rafsanjan and Zarand,Iran

Objective:Vitiligo is a chronic autoimmune depigmenting skin disorder.In this disease,the destruction of functional melanocytes can lead to reduced or absent pigmentation of the skin.Vitamin D deficiency has been reported in some autoimmune diseases.The association of eosinophils and basophils with autoimmune diseases has also been recently examined.The present study was performed to evaluate the serum vitamin D concentration and blood eosinophil and basophil counts in patients with vitiligo.Methods:Data from 30 patients aged 20 to 40 years with vitiligo and 30 healthy people were collected.Blood samples were obtained to evaluate the serum vitamin D concentration,and eosinophil and basophil counts.The serum vitamin D concentration was measured by enzyme-linked immunosorbent assay.Independent t-test was used to compare the quantitative variables between the groups.Results:This descriptive cross-sectional study involved 30 patients with vitiligo.The average serum vitamin D concentration was significantly lower in the case group than in the control group(P=0.01).Furthermore,the mean serum vitamin D concentration was significantly lower in women than in men(P=0.03).The average eosinophil and basophil counts were not significantly different between the case and control groups.Discussion:The results of this study showed that the serum vitamin D concentration is low in patients with vitiligo.However,whether this reduction is a factor in the promotion of vitiligo or occurs after the onset of vitiligo remains unknown.Further studies on the serum vitamin D concentration in patients with vitiligo are needed to clarity this issue and develop effective treatments.

Effect of Q-switched alexandrite laser irradiation on dermal melanocytes of nevus of Ota

OBJECTIVE: To investigate the effect of Q-switched alexandrite laser irradiation on dermal melanocytes of nevus of Ota. METHODS: Multiple biopsies were carried out on 4 patients with nevus of Ota before and after laser irradiation. Altogether 11 samples were examined under light microscope and 14 under transmission electron microscope. RESULTS: Immediately after laser irradiation, the dermal melanocytes were destroyed, the melanosomes were degenerated with central vesicle formation within most of them, and intradermal round vacuoles appeared. The epidermis remained intact. Three months to 1 year after irradiation, the degenerated melanosomes and cell debris were scavenged mainly by macrophages. Dermal melanocytes gradually decreased. No fibrosis was found. CONCLUSION: Q-switched alexandrite laser can selectively destroy dermal melanocytes of nevus of Ota and treat the disease safely.