ABSTRACT
A 22-year-old female patient presented with skin flushing in the bilateral legs for 4 years, which gradually spread throughout the whole lower limbs and forearms 6 months ago. Skin examination showed diffuse flushing and dilated capillaries in the lower limbs and both forearms, and the flushing faded after a press. Histopathological examination of the skin lesion on the leg showed hyperkeratosis in a basket-like shape, increased pigmentation in the basal layer, infiltration of the superficial dermis with scattered lymphocytes, with no obvious red blood cell overflow; periodic acid-Schiff staining showed thickened and homogeneous deposits around the blood vessels; immunohistochemical staining showed thickened blood vessel walls and positive staining for type Ⅳ collagen. Diagnosis: cutaneous collagenous vasculopathy.
ABSTRACT
Objective To evaluate the effect of selenomethionine (Se-Met) against ultraviolet B (UVB)-induced oxidative damage to human HaCaT keratinocytes,and to explore its possible mechanisms.Methods Cultured HaCaT cells were divided into several groups:normal control group receiving no treatment,Se-Met groups treated with Se-Met at concentrations of 1,10,50,100,200 nmol/L and 1 μmol/L for 24 hours respectively,UVB groups irradiated with UVB of 30,60 and 90 mJ/cm2 respectively,Se-Met + UVB groups treated with Se-Met at concentrations of 1,10,50,100,200 nmol/L and 1 μmol/L for 24 hours firstly,then irradiated with UVB of 30,60 and 90 mJ/cm2 respectively.Subsequently,methyl thiazolyl tetrazolium (MTT) assay was performed to estimate cellular proliferative activity,flow cytometry to detect cell apoptosis,colorimetry to evaluate superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and to determine malondialdehyde (MDA) levels.Statistical analysis was carried out by using factorial design analysis of variance (ANOVA),one-way ANOVA and least significant difference (LSD) test.Results Factorial design ANOVA showed that UVB radiation had an inhibitory effect on the proliferative activity of HaCaT cells (F =128.04,P ＜ 0.05),which significantly decreased along with the increase of UVB doses,with significant differences between the three UVB groups (P ＜ 0.05).Se-Met pretreatment also affected cellular proliferative activity (F =5.95,P ＜ 0.05),which was significantly increased in Se-Met (10 nmol/L-1 μmol/L) + UVB groups compared with the UVB groups at corresponding doses (all P ＜ 0.05).There was no significant interaction effect on cellular proliferative activity between UVB radiation and Se-Met pretreatment (F =1.65,P ＞ 0.05).The apoptosis rate of HaCaT cells in the 30-mJ/cm2 UVB group was 31.9％ ± 2.67％,significantly higher than that in the normal control group (4.1％ ± 0.67％,P＜ 0.05) and in the 10-,50-,100-,200-nmol/L and 1-μmol/L Se-Met + 30-mJ/cm2 UVB groups (21.9％ ± 3.72％,17.2％ ± 1.67％,4.6％ ±-0.85％,7.5％ ± 1.86％ and 13.5％ ± 1.95％ respectively,all P ＜ 0.05).Similarly,SOD and GSH-Px activities were significantly weaker (both P ＜ 0.05),while MDA levels were higher (all P ＜ 0.05) in the 30-mJ/cm2 UVB group than in the normal control group;however,there was a significant increase in SOD and GSH-Px activities but a decrease in MDA levels in the Se-Met (10 nmol/L-1 μmol/L) + 30-mJ/cm2 UVB groups compared with the 30-mJ/cm2 UVB group (all P ＜ 0.05).Conclusions Se-Met can reduce UVB-induced oxidative damage to HaCaT cells,likely by enhancing antioxidase activity and decreasing oxygen radicals.
ABSTRACT
AIM: To investigate the protective effect of sodium selenite ( Na2 SeO3 ) on human keratinocytes under ultraviolet-B (UVB) irradiation.METHODS: The cultured HaCaT cells were divided into 4 groups: (1) normal control group;(2) Na2 SeO3 group:pretreated with Na2 SeO3 at doses of 10 nmol/L, 50 nmol/L, 100 nmol/L, 200 nmol/L and 1 μmol/L for 24 h;(3) UVB group: irradiated with UVB at doses of 300, 600 and 900 J/m2; (4) Na2SeO3 +UVB group:after pretreated with Na2SeO3 for 24 h, irradiated with UVB at doses of 300, 600 and 900 J/m2.The cell pro-liferation was detected by MTT assay .The apoptotic rates of HaCaT cells treated with UVB at dose of 300 J/m2 were as-sessed by flow cytometry .RESULTS:Compared with normal control group , the cell proliferation activity in UVB group de-creased significantly ( P<0.05 ) .The cell activity was inversely correlated with the irradiation intensity .No significant difference of the cell activity between Na 2 SeO3 group and normal control group was observed .The cell proliferation in Na2SeO3 +UVB group was higher than that in UVB group significantly (P<0.05).Na2SeO3 at concentration of 100 nmol/L showed the strongest activity to promote cell proliferation .After 300 J/m2 UVB irradiation, the apoptotic rate in Na2SeO3+UVB group decreased significantly ( P<0.05) compared with UVB group .The inhibitory effect of Na 2 SeO3 at concentra-tion of 100 nmol/L on apoptosis was the strongest .CONCLUSION: The damage of human keratinocytes by UVB irradia-tion is in a dose-dependent manner .The photoprotection performance of Na 2 SeO3 reduces the damage of human keratino-cytes induced by UVB irradiation .
ABSTRACT
Objective To investigate the effects of intense pulsed light (IPL) irradiation on the content of collagen fibers, elastic fibers and hyaluronic acid in Kunming mouse skin. Methods The dorsal skin of mice was divided into two areas: the right area was irradiated with IPL, and the left remaining unirradiated served as the control. Skin specimens were taken from the back of mice on day 1, 3, week 1, 2, 4 and 8 after the irradiation and subjected to staining with HE, sirius red and Gomori aldehyde-fuchsin for examinations of histological changes, type Ⅰ and Ⅲ collagen fibers and elastic fibers. The hydroxyproline and hyaluronic acid content in skin tissues of mice was determined with ultraviolet spectrophotometry and radioimmunoassay respectively. Results After irradiation, a significant increase was observed in dermal thickness on week 2 (t =4.623, P＜ 0.05), 4, and 8 (t = 3.904, P＜ 0.05), in type Ⅲ collagen fiber (t = 5.129, P＜ 0.05) on week 1,in type Ⅰ and Ⅲ collagen fibers on week 2, 4 and 8 (both P＜ 0.05), in elastic fibers from week 2 to 8 (P ＜0.05), and in hydroxyproline content from week 1 to 8 (all P ＜ 0.05) in the skin of mice compared with unirradiated mice. In detail, dermal thickness increased by 18.71% on week 4, and type Ⅲ collagen fiber by 40.54% in irradiated mice compared with unirradiated mice. Further more, the hyaluronic acid content was elevated from day 1 to 3, but gradually declined from week 1 to 8, and remained statistically higher from day 1 to week 8 (P ＜ 0.05) in irradiated mice compared to unirradiated mice. Conclusion IPL irradiation could induce an increase in the content of collagen fiber, elastic fiber and hyaluronic acid in the dorsal skin of mice.