UV-based therapy and vitamin D

Novel UV-B Phototherapy With a Light-Emitting Diode Device Prevents Atherosclerosis by Augmenting Regulatory T-Cell Responses in Mice

BACKGROUND

Ultraviolet B (UV-B) irradiation is an effective treatment for human cutaneous disorders and was shown to reduce experimental atherosclerosis by attenuating immunoinflammatory responses. The aim of this study was to clarify the effect of specific wavelengths of UV-B on atherosclerosis and the underlying mechanisms focusing on immunoinflammatory responses.

METHODS AND RESULTS

Based on light-emitting diode technology, we developed novel devices that can emit 282 nm UV-B, which we do not receive from natural sunlight, 301 nm UV-B, and clinically available 312 nm UV-B. We irradiated 6-week-old male atherosclerosis-prone Apoe-/- (apolipoprotein E-deficient) mice with specific wavelengths of UV-B and evaluated atherosclerosis and immunoinflammatory responses by performing histological analysis, flow cytometry, biochemical assays, and liquid chromatography/mass spectrometry-based lipidomics. Irradiation of 282 nm UV-B but not 301 or 312 nm UV-B significantly reduced the development of aortic root atherosclerotic plaques and plaque inflammation. This atheroprotection was associated with specifically augmented immune responses of anti-inflammatory CD4+ Foxp3 (forkhead box P3)+ regulatory T cells in lymphoid tissues, whereas responses of other immune cells were not substantially affected. Analysis of various lipid mediators revealed that 282 nm UV-B markedly increased the ratio of proresolving to proinflammatory lipid mediators in the skin.

CONCLUSIONS

We demonstrated that 282 nm UV-B irradiation effectively reduces aortic inflammation and the development of atherosclerosis by systemically augmenting regulatory T-cell responses and modulating the balance between proresolving and proinflammatory lipid mediators in the skin. Our findings indicate that a novel 282 nm UV-B phototherapy could be an attractive approach to treat atherosclerosis.

Pharmacological Management of Pediatric Pustular Psoriasis

Therapeutic management of pustular psoriasis remains a challenge despite the rapid advance in psoriasis research and the development of drugs, especially biologics. Treatment guidelines have been established for pustular psoriasis, but no controlled studies are present for juvenile pustular psoriasis (JPP). Search of the literature reveals that current evidence of JPP treatment is limited to case reports and case series. Among the conventional drugs for JPP, oral retinoid is the most commonly used, yet concerns for growth disturbance exist. Cyclosporine and methotrexate have also been administered as first-line treatment. Etanercept is the first biological agent approved for juvenile plaque psoriasis, followed by adalimumab. However, infliximab is usually recommended for JPP because of the rapidity of onset, despite not being approved for use in pediatric psoriasis patients. More recently, secukinumab, ixekizumab, brodalumab, guselkumab, and risankizumab have been approved for adult pustular psoriasis in selected countries. Controlled studies are needed to prove the efficacy and long-term safety of the therapeutic treatments currently used for JPP.

Comparative In Vitro Study: Examining 635 nm Laser and 265 nm Ultraviolet Interaction with Blood

Objective: This study represents a viable assessment of the effect of the low-level laser (LLL) of 635 nm and ultraviolet (UV) of 265 nm on biophysical properties of blood. Materials and methods: Blood samples were divided into two main groups: one for irradiation by LLL and the other for irradiation by UV. Each group was divided into three aliquots. First aliquot: whole blood was exposed to radiation. The second aliquot: erythrocytes were exposed to radiation and resuspended in autologous plasma. The third aliquot: plasma was exposed to radiation, and erythrocytes were resuspended in it. The following parameters were measured after irradiation by LLL and UV for all aliquots: whole blood viscosity, microscopic aggregation index, deformation index, and Zeta potential. Results: A decrease in whole blood viscosity due to irradiation by LLL was observed. To the contrary, an increase in whole blood viscosity due to irradiation by UV was detected. A significant reduction in erythrocytes' aggregation was observed as a result of LLL and UV radiation. Erythrocytes' deformability was strongly affected by UV radiation, while there was no significant effect from LLL. Another noticeable change observed was an increase in Zeta potential due to UV and a decrease in Zeta potential values, as a result of LLL irradiation. Conclusions: It can be concluded from this study that LLL and UV can be used to change some biological processes, as well as cellular properties.

Promotion of fracture healing by conjugated linoleic acid in rats

BACKGROUND

The ability of fracture healing in Tibetans is significantly superior to Chinese Hans, which may attribute to factors from diet, altitude to physical conditions. Conjugated linoleic acid (CLA) is an important ingredient in Tibetan diet, playing a role in antioxidation, antiatherosclerosis, and decrease in body fat accumulation.  Methods: This study further quantified CLA effect in fracture healing in rats using combined structural evaluation (X-ray and micro-computed tomography), biomechanical test, and histological examination.

RESULTS

CLA could promote fracture healing with quicker development of trabecular connection, network and thickening and were more active at the stage of bony union and remodeling. The load to failure could reach 78.12 ± 10.03 N, 41.4% stronger than the control by week 6 ( p = 0.0209).

CONCLUSIONS

CLA improved the quality and mechanical strength of fracture healing in rats callus. The information may offer insight in development of new therapeutic strategies of fracture healing for general populations beyond Tibetans.

Short-term UVB irradiation significantly increases vitamin D serum concentration in obese patients: a clinical pilot study

PURPOSE

Deficiency of vitamin D is very common in obese people and treatment by oral supplementation is not effective in all patients. This exploratory pilot study investigated the influence of different doses of short-term ultraviolet B irradiation on serum 25-hydroxyvitamin-D₃ (25D) and 1,25-dihydroxyvitamin-D₃ (1,25D) levels in obese compared to normal weight subjects and obese controls.

METHODS

Participants with skin types II and III (Fitzpatrick skin classification) were assigned to six groups including four intervention groups receiving irradiation (three groups of obese and one group of normal weight subjects) and two control groups without treatment (obese and normal weight). Intervention groups received three sessions of whole body UVB irradiation of three different doses (cumulative doses over three sessions: 0.28, 0.70, 1.75 minimal erythema dose) within 1 week of intervention. Serum 25D and 1,25D were measured at baseline and after irradiation. Outcome differences between groups were analyzed using a linear model.

RESULTS

Serum 25D levels increased significantly in obese (+23.6 and +26.7%, respectively, p = 0.01) and normal weight (+15.6%, p = 0.02) intervention groups who received medium and high doses of ultraviolet B irradiation compared to control groups (+3.5 and -4.0%, respectively, p = 1.0). The increase in obese patients was 51.4% greater compared to normal weight controls irradiated with equal ultraviolet B doses. Low-level ultraviolet irradiation did not result in a significant change in serum 25D (+7.0%, p = 0.61). We did not detect any significant differences of 1,25D between groups (p = 0.25).

CONCLUSIONS

The current study indicates that short-term ultraviolet B irradiation increases 25D levels in obese patients.

Protective and therapeutic effects of fucoxanthin against sunburn caused by UV irradiation

Mild exposure to ultraviolet (UV) radiation is also harmful and hazardous to the skin and often causes a photosensitivity disorder accompanied by sunburn. To understand the action of UV on the skin we performed a microarray analysis to isolate UV-sensitive genes. We show here that UV irradiation promoted sunburn and downregulated filaggrin (Flg); fucoxanthin (FX) exerted a protective effect. In vitro analysis showed that UV irradiation of human dermal fibroblasts caused production of intracellular reactive oxygen species (ROS) without cellular toxicity. ROS production was diminished by N-acetylcysteine (NAC) or FX, but not by retinoic acid (RA). In vivo analysis showed that UV irradiation caused sunburn and Flg downregulation, and that FX, but not NAC, RA or clobetasol, exerted a protective effect. FX stimulated Flg promoter activity in a concentration-dependent manner. Flg promoter deletion and chromatin immunoprecipitation analysis showed that caudal type homeo box transcription factor 1 (Cdx1) was a key factor for Flg induction. Cdx1 was also downregulated in UV-exposed skin. Therefore, our data suggested that the protective effects of FX against UV-induced sunburn might be exerted by promotion of skin barrier formation through induction of Flg, unrelated to quenching of ROS or an RA-like action.

Guidelines for phototherapy of mycosis fungoides and Sézary syndrome: A consensus statement of the United States Cutaneous Lymphoma Consortium

BACKGROUND

Ultraviolet light (UVL) is a long established treatment for mycosis fungoides (MF) and Sézary syndrome (SS), subtypes of cutaneous T-cell lymphoma (CTCL). Treatments have traditionally included broadband, narrowband ultraviolet B light (UVB) and psoralen plus ultraviolet A light photochemotherapy (PUVA), but more recently, treatment options have expanded to include UVA1 and excimer laser. UVL is used either as monotherapy or as an adjuvant to systemic therapy, demonstrating efficacy in many cases that equal or surpass systemic medications. Despite its utility and duration of use, the current practice of using UVL guidelines for psoriasis to treat patients with MF/SS is problematic because the goals of prolonging survival and preventing disease progression are unique to CTCL compared to psoriasis.

OBJECTIVES

We sought to develop separate guidelines for phototherapy for MF/SS for both clinical practice and for clinical trials.

METHODS

Literature review and cutaneous lymphoma expert consensus group recommendations.

RESULTS

This paper reviews the published literature for UVB and UVA/PUVA in MF/SS and suggests practical standardized guidelines for their use.

LIMITATIONS

New standardization of phototherapy.

CONCLUSIONS

These guidelines should allow the comparison of results with phototherapy in MF/SS across different stages of patients, centers, and in combination with other agents in practice and in clinical trials.

Prevalence study of dermatoses referred to the phototherapy unit at the Dermatology Service of the Clinics Hospital of Porto Alegre, RS, Brazil

BACKGROUND

Phototherapy consists of exposure to ultraviolet radiation for therapeutic reasons. Radiation is already used in dermatological practice, and many studies have already proved the beneficial effect of UV light treatment for chronic inflammatory or lymphoproliferative skin diseases. The Dermatology Service of the Clinics Hospital of Porto Alegre (Hospital de Clínicas de Porto Alegre) has been using phototherapy for a long time, and no official data have been described so far.

OBJECTIVES

To study the prevalence of dermatoses referred to the phototherapy unit at the Clinics Hospital of Porto Alegre and describe the total number of patients who have already been referred to this sector and their phototype.

METHODS

This is a descriptive cross-sectional study. Data were collected through a review of the phototherapy patients' records (secondary data), which are available on a database of the Dermatology Service of the Clinics Hospital of Porto Alegre, from August 1997 to July 2011.

RESULTS

A total of 653 records were analyzed. Phototype 3 was the most prevalent (n=313). Distribution of the prevalence of dermatoses referred to the phototherapy unit was as follows: vitiligo (279), psoriasis (255), cutaneous T-cell lymphoma/mycosis fungoides (29), graftversus-host disease (15), scleroderma (11), atopic dermatitis (10), alopecia areata (6), parapsoriasis (5), eczema (4), granuloma annulare (4), and others (35). As vitiligo and psoriasis were the two most prevalent dermatoses, they were analyzed separately, with no statistical difference in prevalence between them (P=0,177).

CONCLUSIONS

Our findings are in accordance with the literature, showing that although phototherapy is still mostly indicated to treat psoriasis, it has been used to treat other dermatoses, since the results are promising.

Treatment of childhood psoriasis with phototherapy and photochemotherapy

Phototherapy and photochemotherapy are well-described treatment modalities for psoriasis in adults. Like many other treatments, the experience and long-term safety of their use in children is limited. We conducted a literature search and identified publications reporting the use of phototherapy and photochemotherapy in pediatric populations. This article summarizes the existing literature on this topic. Although many studies report good improvement with these treatment modalities, long-term safety data on their use is lacking for pediatric patients.

Beneficial effects of UV radiation other than via vitamin D production

Most of the positive effects of solar radiation are mediated via ultraviolet-B (UVB) induced production of vitamin D in skin. However, several other pathways may exist for the action of ultraviolet (UV) radiation on humans as focused on in this review. One is induction of cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning). UVB-induced, delayed tanning (increases melanin in skin after several days), acts as a sunscreen. Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with solar radiation (heliotherapy) or artificial UV radiation (phototherapy). UV exposure can suppress the clinical symptoms of multiple sclerosis independently of vitamin D synthesis. Furthermore, UV generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health. UVA-induced NO may also have antimicrobial effects and furthermore, act as a neurotransmitter. Finally, UV exposure may improve mood through the release of endorphins.

Ultraviolet C irradiation: an alternative antimicrobial approach to localized infections?

This review discusses the potential of ultraviolet C (UVC) irradiation as an alternative approach to current methods used to treat localized infections. It has been reported that multidrug-resistant microorganisms are equally sensitive to UVC irradiation as their wild-type counterparts. With appropriate doses, UVC may selectively inactivate microorganisms while preserving viability of mammalian cells and, moreover, is reported to promote wound healing. UVC is also found in animal studies to be less damaging to tissue than UVB. Even though UVC may produce DNA damage in mammalian cells, it can be rapidly repaired by DNA repair enzymes. If UVC irradiation is repeated excessively, resistance of microorganisms to UVC inactivation may develop. In summary, UVC should be investigated as an alternative approach to current methods used to treat localized infections, especially those caused by multidrug-resistant microorganisms. UVC should be used in a manner such that the side effects would be minimized and resistance of microorganisms to UVC would be avoided.

A dermatologist's perspective on vitamin D

Vitamin D is a fat-soluble steroid hormone that is crucial for human health and has recently generated controversy regarding its role in human health and disease. In this Special Article, we discuss our dermatologic perspective on vitamin D in a question-and-answer format. We discuss methods of obtaining vitamin D, including cutaneous photobiosynthesis, diet, and supplements and include the recent US Institute of Medicine recommendations. Other reviewed topics include the associations among skin pigmentation, climate, photoprotection, and vitamin D levels. We also elaborate on the popular interest in sun exposure as a method of normalizing vitamin D levels in the context of the risks of solar and artificial radiation. We also discuss groups at risk for vitamin D inadequacy, the need for testing serum vitamin D levels, and the role of phototherapy in patients with malabsorption conditions and hypervitaminosis D, with a focus on patients with sarcoidosis. Finally, we summarize our recommendations on vitamin D.

Surface lipids as multifunctional mediators of skin responses to environmental stimuli

Skin surface lipid (SSL) film is a mixture of sebum and keratinocyte membrane lipids, protecting skin from environment. Its composition is unique for the high percentage of long chain fatty acids, and of the polyterpenoid squalene, absent in other human tissues, and in non-human Primates sebum. Here, the still incomplete body of information on SSL as mediators of external chemical, physical, and microbial signals and stressors is revised, focusing on the central event of the continuous oxidative modification induced by the metabolic activity of residential and pathological microbial flora, natural or iatrogenic UV irradiation, exposure to chemicals and cosmetics. Once alpha-tocopherol and ubiquinol-10 antioxidant defences of SSL are overcome, oxidation of squalene and cholesterol gives rise to reactive by-products penetrating deeper into skin layers, to mediate local defensive inflammatory, photo-protective, immune reactions or, at higher concentrations, inducing local but also systemic immune depression, ultimately implicating skin cancerogenesis. Qualitative modifications of SSL represent a pathogenetic sign of diagnostic value in dermatological disorders involving altered sebum production, like pytiriasis versicolor, acne, atopic or seborrheic dermatitis, as well as photo-aging. Achievements of nutriceutical interventions aimed at restoring normal SSL composition and homeostasis are discussed, as feasible therapeutic goals and major means of photo-protection.