In vivo UVA irradiation of mouse is more efficient in promoting pulmonary melanoma metastasis than in vitro

<p>Abstract</p> <p>Background</p> <p>We have previously shown <it>in vitro </it>that UVA increases the adhesiveness of mouse B16-F1 melanoma cells to endothelium.</p> <p>We have also shown <it>in vivo </it>that UVA exposure of C57BL/6 mice, <it>i.v</it>. injected with B16-F1 cells, increases formation of pulmonary colonies of melanoma. The aim of the present animal study was to confirm the previously observed <it>in vivo </it>UVA effect and to determine whether <it>in vitro </it>UVA-exposure of melanoma cells, prior the <it>i.v</it>. injection, will have an enhancing effect on the pulmonary colonization capacity of melanoma cells. As a second aim, UVA-derived immunosuppression was determined.</p> <p>Methods</p> <p>Mice were <it>i.v</it>. injected with B16-F1 cells into the tail vein and then immediately exposed to UVA. Alternatively, to study the effect of UVA-induced adhesiveness on the colonization capacity of B16-F1 melanoma, cells were <it>in vitro </it>exposed prior to <it>i.v</it>. injection. Fourteen days after injection, lungs were collected and the number of pulmonary nodules was determined under dissecting microscope. The UVA-derived immunosuppression was measured by standard contact hypersensitivity assay.</p> <p>Results and Discussion</p> <p>Obtained results have confirmed that mice, <it>i.v</it>. injected with B16-F1 cells and thereafter exposed to UVA, developed 4-times more of melanoma colonies in lungs as compared with the UVA non-exposed group (p < 0.01). The <it>in vitro </it>exposure of melanoma cells prior to their injection into mice, led only to induction of 1.5-times more of pulmonary tumor nodules, being however a statistically non-significant change. The obtained results postulate that the UVA-induced changes in the adhesive properties of melanoma cells do not alone account for the 4-fold increase in the pulmonary tumor formation. Instead, it suggests that some systemic effect in a mouse might be responsible for the increased metastasis formation. Indeed, UVA was found to induce moderate systemic immunosuppression, which effect might contribute to the UVA-induced melanoma metastasis in mice lungs.</p

Narrowband Ultraviolet B Exposures Maintain Vitamin D Levels During Winter : A Randomized Controlled Trial

Exposure to solar ultraviolet B radiation during the summer months is the main source of vitamin D (VD) for people living in northern latitudes. The aim of this study was to determine whether artificial narrowband ultraviolet B (NB-UVB) whole-body exposures could maintain VD levels in winter. The intervention group received 2 standard erythema doses (SEDs) of NB-UVB exposures every second week from October 2013 to April 2014. In October 2013 serum 25-hydroxyvitamin D concentrations were 78.3 nmol/l in the intervention group (n=16) and 76.8 nmol/l in the control group (n=18). By April 2014 the concentrations had increased by 11.7 nmol/l (p=0.029) in the intervention group and decreased by 11.1 nmol/l (p=0.022) in the control group. The baseline VD concentration showed a negative correlation (p=0.012) with body mass index (BMI). In conclusion, a suberythemal NB-UVB dose of 2 SED every second week maintains and even increases serum VD concentrations during the winter. A high BMI seems to predispose subjects to low levels of VD.Peer reviewe

Empowering Heliotherapy Improves Clinical Outcome and Quality of Life of Psoriasis and Atopic Dermatitis Patients

Empowering heliotherapy aims at clinical healing and improved coping with psoriasis and atopic dermatitis, but evidence of long-term effects is scarce. We studied the effect of 2-week empowering heliotherapy in the Canary Islands on clinical outcome and quality of life in 22 psoriasis and 13 atopic dermatitis patients. Empowerment consisted of meeting peers, sharing experiences and performing physical and mental practices. Using the self-administered PASI (SAPASI) psoriasis was alleviated statistically significantly during heliotherapy (p <0.001), and the treatment effect was still detectable 3 months later (p <0.001). Atopic dermatitis was improved (p <0.001) when assessed with the patient-oriented SCORAD (PO-SCORAD), and the effect was still obvious 3 months later (p = 0.002). During heliotherapy the dermatology life quality index (DLQI) improved in both groups (p <0.001), persisting in atopic patients for up to 3 months (p = 0.002), but not in psoriasis patients. In conclusion, a 2-week empowered heliotherapy showed a long-lasting improvement in psoriasis and atopic dermatitis disease activity, and also in the quality of life of atopic patients.Peer reviewe

Influence of ultraviolet A1 exposures on mood states: a randomized controlled study

Peer reviewe

The effect of vernal solar UV radiation on serum 25-hydroxyvitamin D concentration depends on the baseline level : observations from a high latitude in Finland

Humans obtain vitamin D from conversion of 7-dehydrocholesterol in the skin by ultraviolet B (UVB) radiation or from dietary sources. As the radiation level is insufficient in winter, vitamin D deficiency is common at higher latitudes. We assessed whether vernal solar UVB radiation at latitudes 61 degrees N and 67 degrees N in Finland has an impact on serum 25-hydroxyvitamin D [S-25(OH) D] concentrations. Twenty-seven healthy volunteers participated in outdoor activities in snow-covered terrain for 4-10 days in March or April, with their face and hands sun-exposed. The personal UVB doses and S-25(OH) D levels were monitored. A mean UVB dose of 11.8 standard erythema doses (SED) was received during an average of 12.3 outdoor hours. The mean S-25(OH) D concentration in subjects with a baseline concentration below 90.0 nmol/L (n=13) increased significantly, by 6.0 nmol/L from an initial mean of 62.4 nmol/L (pPeer reviewe

Diurnal Preference Contributes to Maximal UVB Sensitivity by the Hour of the Day in Human Skin In Vivo

Non peer reviewe

Narrow-band UVB radiation triggers diverse changes in the gene expression and induces the accumulation of M1 macrophages in human skin

Background: The underlying molecular mechanisms that determine the biological effects of UVB radiation exposure on human skin are still only partially comprehended. Objectives: Our goal is to examine the human skin transcriptome and related molecular mechanisms following a single exposure to UVB in the morning versus evening. Methods: We exposed 20 volunteer females to four-fold standard erythema doses (SED4) of narrow-band UVB (309–313 nm) in the morning or evening and studied skin transcriptome 24 h after the exposure. We performed enrichment analyses of gene pathways, predicted changes in skin cell composition using cellular deconvolution, and correlated cell proportions with gene expression. Results: In the skin transcriptome, UVB exposure yielded 1384 differentially expressed genes (DEGs) in the morning and 1295 DEGs in the evening, of which the most statistically significant DEGs enhanced proteasome and spliceosome pathways. Unexposed control samples showed difference by 321 DEGs in the morning vs evening, which was related to differences in genes associated with the circadian rhythm. After the UVB exposure, the fraction of proinflammatory M1 macrophages was significantly increased at both timepoints, and this increase was positively correlated with pathways on Myc targets and mTORC1 signaling. In the evening, the skin clinical erythema was more severe and had stronger positive correlation with the number of M1 macrophages than in the morning after UVB exposure. The fractions of myeloid and plasmacytoid dendritic cells and CD8 T cells were significantly decreased in the morning but not in the evening. Conclusions: NB-UVB-exposure causes changes in skin transcriptome, inhibiting cell division, and promoting proteasome activity and repair responses, both in the morning and in the evening. Inflammatory M1 macrophages may drive the UV-induced skin responses by exacerbating inflammation and erythema. These findings highlight how the same UVB exposure influences skin responses differently in morning versus evening and presents a possible explanation to the differences in gene expression in the skin after UVB irradiation at these two timepoints.Peer reviewe

Ultraviolet B radiation modifies circadian time in epidermal skin and in subcutaneous adipose tissue

Background Recent findings suggest that circadian time regulates cellular functions in the skin and may affect protection against ultraviolet radiation (UVR). It is not known, however, whether UVR through skin directly affects the expression of circadian genes. We investigated the effect of ultraviolet B (UVB) exposure on cryptochrome circadian clock 1 (CRY1), cryptochrome circadian clock 2 (CRY2), and circadian associated repressor of transcription (CIART) genes. Methods Healthy volunteers (n = 12) were exposed to narrow-band UVB radiation of four standard erythemal dose (SED). Epidermal/dermal and subcutaneous adipose tissue samples were obtained by punch biopsies from irradiated and non-irradiated skin 10 cm away from the irradiated site 24 hours after UVB exposure. Gene expression of CRY1, CRY2, and CIART was measured using RT-PCR (TaqMan). Results Ultraviolet B radiation affected mRNA expression in the epidermal/dermal skin and in the subcutaneous adipose tissue. It down-regulated expression of CRY2 gene in the epidermal/dermal skin, whereas it up-regulated expression of CRY1 and CIART genes in the subcutaneous adipose tissue. Conclusion We showed for the first time that UVB radiation affects expression of circadian genes in the subcutaneous adipose tissue. Further studies are warranted to understand the mechanisms in detail.Peer reviewe