Modulation of the immune system by UV radiation: more than just the effects of vitamin D? Nat Rev Immunol. 2011;11:584-596. [PMID: 21852793 DOI: 10.1038/nri3045]

Interplay between polygenic risk score and solar insolation: Implication for systemic lupus erythematosus diagnosis and pathogenesis

OBJECTIVES

This research elucidates the correlation between solar radiation insolation, polygenic risk score (PRS), and systemic lupus erythematosus (SLE) diagnosis, utilizing genomic, environmental, and clinical data.

METHODS

We included 1,800 SLE participants and 1,800 controls from the Taiwan Precision Medicine Initiative, genotyped via the Affymetrix Genome-Wide TWB 2.0 SNP Array. The study employed a SLE-PRS tailored for individuals of Taiwanese ancestry, comprising 27 single nucleotide polymorphisms (SNPs). QGIS computed solar radiation insolation from participants' residences. We employed logistic regression to investigate the associations between SLE-PRS, solar insolation susceptibility, and SLE. Additive and multiplicative interactions were utilized to assess the interactions between solar insolation and SLE-PRS regarding the risk of SLE.

RESULTS

SLE patients showed decreased solar insolation (p < 0.001). The highest decile of SLE-PRS exhibited a statistically significant lower solar insolation 1, 3, 6, and 12 months prior to diagnosis as compared to the lowest decile. Specifically, there were significant differences observed at 1 and 12 months (p = 0.025 and p = 0.004, respectively). It suggests that higher SLE-PRS correlated with reduced solar insolation tolerance. We observed an increase in SLE risk across ascending SLE-PRS percentiles exclusively in the high solar insolation group, not in the low solar insolation group. However, the interaction effect of SLE-PRS and solar insolation on SLE risk is not statistically significant. Compared to the lowest decile, the highest SLE-PRS decile showed a 10.98-fold increase in SLE risk (95 % CI, 3.773-31.952, p < 0.001). High SLE-PRS scores in conjunction with high solar insolation contribute to SLE incidence.

CONCLUSIONS

Our study unveils the intertwined nature of UV insolation and polygenic risks in SLE. Future studies should explore the preventative potential of robust solar radiation protection for high-risk individuals before the disease onset.

Serum 25-hydroxyvitamin D concentrations, vitamin D receptor polymorphisms, and risk of infections among individuals with type 2 diabetes: a prospective cohort study

BACKGROUND

Evidence on the association between serum 25-hydroxyvitamin D [25(OH)D] and infections among patients with type 2 diabetes (T2D), a group susceptible to vitamin D deficiency and infections, is limited.

OBJECTIVES

We aimed to examine this association in individuals with T2D, and to evaluate whether genetic variants in vitamin D receptor (VDR) would modify this association.

METHODS

This study included 19,851 participants with T2D from United Kingdom Biobank. Infections were identified by linkage to hospital inpatient and death registers. Negative binomial regression models were used to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CIs), with adjustment of potential confounders.

RESULTS

In patients with T2D, the incidence rate of infections was 29.3/1000 person-y. Compared with those with 25(OH)D of 50.0-74.9 nmol/L, the multivariable-adjusted IRRs and 95% CIs of total infections, pneumonia, gastrointestinal infections, and sepsis were 1.44 (1.31, 1.59), 1.49 (1.27, 1.75), 1.47 (1.22, 1.78), and 1.41 (1.14, 1.73), respectively, in patients with 25(OH)D <25.0 nmol/L. Nonlinear inverse associations between 25(OH)D concentrations and the risks of total infections (P-overall < 0.001; P-nonlinear = 0.002) and gastrointestinal infections (P-overall < 0.001; P-nonlinear = 0.040) were observed, with a threshold effect at ∼50.0 nmol/L. The vitamin D-infection association was not modified by genetic variants in VDR (all P-interaction > 0.050).

CONCLUSIONS

In patients with T2D, lower serum 25(OH)D concentration (<50 nmol/L) was associated with higher risks of infections, regardless of genetic variants in VDR. Notably, nonlinear inverse associations between 25(OH)D concentrations and the risks of infections were found, with a threshold effect at ∼50.0 nmol/L. These findings highlighted the importance of maintaining adequate vitamin D in reducing the risk of infections in patients with T2D.

Global impacts of an extreme solar particle event under different geomagnetic field strengths

Solar particle events (SPEs) are short-lived bursts of high-energy particles from the solar atmosphere and are widely recognized as posing significant economic risks to modern society. Most SPEs are relatively weak and have minor impacts on the Earth's environment, but historic records contain much stronger SPEs which have the potential to alter atmospheric chemistry, impacting climate and biological life. The impacts of such strong SPEs would be far more severe when the Earth's protective geomagnetic field is weak, such as during past geomagnetic excursions or reversals. Here, we model the impacts of an extreme SPE under different geomagnetic field strengths, focusing on changes in atmospheric chemistry and surface radiation using the atmosphere-ocean-chemistry-climate model SOCOL3-MPIOM and the radiation transfer model LibRadtran. Under current geomagnetic conditions, an extreme SPE would increase NOx concentrations in the polar stratosphere and mesosphere, causing reductions in extratropical stratospheric ozone lasting for about a year. In contrast, with no geomagnetic field, there would be a substantial increase in NOx throughout the entire atmosphere, resulting in severe stratospheric ozone depletion for several years. The resulting ground-level ultraviolet (UV) radiation would remain elevated for up to 6 y, leading to increases in UV index up to 20 to 25% and solar-induced DNA damage rates by 40 to 50%. The potential evolutionary impacts of past extreme SPEs remain an important question, while the risks they pose to human health in modern conditions continue to be underestimated.

Prior Nonmelanoma Skin Cancer is Associated with Fewer Fractures, More Vitamin D Sufficiency, Greater Bone Mineral Density, and Improved Bone Microarchitecture in Older Adults

BACKGROUND

Prior nonmelanoma skin cancer (NMSC), a biomarker of cumulative lifetime sun exposure, is associated with reduced fracture risk later in life. The mechanism is unknown.

METHODS

Prospective cohort analysis of 1099 community-dwelling adults aged 50-80 years with baseline and 10-year follow-up assessments. Histopathologically-confirmed NMSC diagnosis was established by linkage with the Tasmanian Cancer Registry. Bone mineral density (BMD) and vertebral deformity were quantified by DXA, 25-hydroxyvitamin D (25(OH)D) by radioimmunoassay, bone microarchitecture by high-resolution peripheral quantitative CT, melanin density by spectrophotometry, and skin photosensitivity and clinical fracture by questionnaire. 25(OH)D <50 nmol/L was considered deficient.

RESULTS

Participants with an NMSC reported prior to baseline were less likely to sustain an incident vertebral deformity over 10 years (RR = 0.74, P = .036). There were similar reductions for other fracture types but these did not reach significance. Prior NMSC was associated with baseline (RR = 1.23, P = .005) and 10-year longitudinal (RR = 5.9, P = .014) vitamin D sufficiency and greater total body BMD (β = 0.021g/cm2, P = .034), but not falls risk or muscle strength. The relationship between prior NMSC and bone microarchitecture was age-dependent (pinteraction < 0.05). In the oldest age tertile, prior NMSC was associated with greater volumetric BMD (β = 57.8-62.6, P = .002-0.01) and less porosity (β = -4.6 to -5.2, P = .002-0.009) at cortical, compact cortical and outer transitional zones.

CONCLUSIONS

Prior NMSC was associated with fewer incident fractures in community-dwelling older adults. This protective association is most likely mediated by modifiable fracture risk factors associated with an outdoor lifestyle, including 25(OH)D, BMD, and bone microarchitecture.

Vitamin D and major chronic diseases

Numerous observational studies have demonstrated a significant inverse association between vitamin D status and the risk of major chronic disease, including type 2 diabetes (T2D), cardiovascular disease (CVD), and cancer. However, findings from Mendelian randomization (MR) studies and randomized controlled trials (RCTs) suggest minimal or no benefit of increased vitamin D levels. We provide an overview of recent literature linking vitamin D to major chronic diseases. Because emerging evidence indicates a potential threshold effect of vitamin D, future well-designed studies focused on diverse populations with vitamin D deficiency or insufficiency are warranted for a more comprehensive understanding of the effect of maintaining sufficient vitamin D status on the prevention of major chronic diseases.

Photodissociation of leucine-enkephalin protonated peptide: an experimental and theoretical perspective

Understanding the competing processes that govern far ultraviolet photodissociation (FUV-PD) of biopolymers such as proteins is a challenge. Here, we report a combined experimental and theoretical investigation of FUV-PD of protonated leucine-enkephalin pentapeptide ([YGGFL + H]+) in the gas-phase. Time-dependent density functional theory (TD-DFT) calculations in combination with experiments and previous results for amino acids and shorter peptides help in rationalizing the evolution of the excited states. The results confirm that fragmentation of [YGGFL + H]+ results mainly from vibrationally excited species in the ground electronic state, populated after internal conversion. We also propose fragmentation mechanisms for specific photo-fragments such as tyrosine side chain loss (with an extra hydrogen) or hydrogen loss. In general, we observe the same mechanisms as for smaller peptides or protonated Tyr and Phe, that are not quenched by the presence of other amino acids. Nevertheless, we also found some differences, as for H loss, in part due to the fact that the charge is solvated by the peptide chain and not only by the COOH terminal group.

A causal analysis of the relationship between exposure to sunlight and colorectal cancer risk: A Mendelian randomization study

Several observational studies have found that exposure to sunlight reduces the risk of colorectal cancer (CRC). However, sun exposure remains ambiguous in its relationship to CRC. We carried out a Mendelian randomization (MR) study to explore the potential associations between them. We examined the exposure to sunlight summary statistics of the UK Biobank Consortium using a 2-sample MR analysis. Using data from the FinnGen consortium, we derived summary statistics for CRC. We conducted our analysis with various methods, incorporating inverse variance weighted (IVW) along with 4 other approaches. A Cochran Q statistic was used to measure the heterogeneity of instrumental variables (IVs). We screened 133 single nucleotide polymorphisms (SNPs) (time spent outdoors in summer), 41 SNPs (time spent outdoors in winter), and 35 SNPs (frequency of solarium/sunlamp use) representing sunlight exposure for MR analysis. All selected SNPs had an F-statistic >20, indicating that IVs did not weakly bias the results. The summer outdoor activity trait exhibited significant heterogeneity (Cochran Q statistic = 183.795, P = .002 < 0.05), but we found no horizontal polymorphisms or significant heterogeneity for the other exposure traits. According to IVW estimates, no causal association exists between time spent outdoors in summer and CRC (Odds Ratio, OR = 0.735, 95% confidence interval, CI = 0.494-1.017, P = .128 > 0.017). No causal relationship existed between time spent outdoors in winter and CRC, as indicated by Bonferroni-corrected adjusted p-values. The OR was 0.877 with a 95% CI of 0.334-2.299, and the P value was .789, more significant than the significance threshold of 0.017. The solarium/sunlamp use frequency was not associated with CRC (OR = 1.567, 95%CI = 0.243-10.119, P = .637 > .017). Also, an IVW with random effects was applied to determine the causal relationship between summer outdoor time and CRC. No causal association between summer outdoor time and CRC was found (OR = 0.735, 95% CI = 0.494-1.017, P = .128 > .017). Additionally, 4 additional analyses yielded similar results. The findings of our study suggest that exposure to sunlight may reduce CRC risk, but the causal relationship remains unsolved. There is no evidence to suggest that exposure to sunlight prevents CRC. Randomized, controlled trials are needed to determine whether sunlight exposure protects against CRC.

VDRA downregulate β-catenin/Smad3 and DNA damage and repair associated with improved prognosis in ccRCC patients

The clear cell renal cell carcinoma (ccRCC) spotlighted the poorest survival, while chromophobe renal cell carcinoma (chRCC) was associated with the best survival. Earlier studies corroborated vitamin D receptor (VDR) was a promising molecular for improving the prognosis of RCC. In contrast to VDRA, the one of VDR isoforms, VDRB1 (VDR isoform B1) has an N-terminal extension of 50 amino acids and is less ligand-dependent. However, the functional differences between VDRA and VDRB1, and their roles in the prognosis of ccRCC and chRCC, have not been investigated. In the present study, we uncovered that the transcripts related to vitamin D pathway and cellular calcium signaling were effectively decreased in the context of ccRCC, yet failed to exert a comparable effect within chRCC. Specially, minimally levels of VDRA wherein kidneys of patients suffering from ccRCC predict shorter survival time. In addition, the protein expressions for β-catenin/Smad3 pathway and DNA damage and repair pathways were obviously impeded in VDRA-overexpressed ccRCC cells, yet this inhibitory effect was conspicuously absent in enable VDRB1 cells. Our results provide a new idea to improve the prognosis of ccRCC via VDRA upregulation.

Associations between combined urban and lifestyle factors and respiratory health in European children

INTRODUCTION

Previous studies identified some environmental and lifestyle factors independently associated with children respiratory health, but few focused on exposure mixture effects. This study aimed at identifying, in pregnancy and in childhood, combined urban and lifestyle environment profiles associated with respiratory health in children.

METHODS

This study is based on the European Human Early-Life Exposome (HELIX) project, combining six birth cohorts. Associations between profiles of pregnancy (38 exposures) and childhood (84 exposures) urban and lifestyle factors, identified by clustering analysis, and respiratory health were estimated by regression models adjusted for confounders.

RESULTS

Among the 1033 included children (mean ± standard-deviation (SD) age: 8.2 ± 1.6 years old, 47% girls) the mean ± SD forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) were 99 ± 13% and 101 ± 14%, respectively, and 12%, 12% and 24% reported ever-asthma, wheezing and rhinitis, respectively. Four profiles of pregnancy exposures and four profiles of childhood exposures were identified. Compared to the reference childhood exposure profile (low exposures), two exposure profiles were associated with lower levels of FEV1. One profile was characterized by few natural spaces in the surroundings and high exposure to the built environment and road traffic. The second profile was characterized by high exposure to meteorological factors and low levels of all other exposures and was also associated with an increased risk of ever-asthma and wheezing. A pregnancy exposure profile characterized by high exposure levels to all risk factors, but a healthy maternal lifestyle, was associated with a lower risk of wheezing and rhinitis in children, compared to the reference pregnancy profile (low exposures).

CONCLUSION

This comprehensive approach revealed pregnancy and childhood profiles of urban and lifestyle exposures associated with lung function and/or respiratory conditions in children. Our findings highlight the need to pursue the study of combined exposures to improve prevention strategies for multifactorial diseases such as asthma.

Role of reactive oxygen species in ultraviolet-induced photodamage of the skin

Reactive oxygen species (ROS), such as superoxides (O2 •-) and hydroxyl groups (OH·), are short-lived molecules containing unpaired electrons. Intracellular ROS are believed to be mainly produced by the mitochondria and NADPH oxidase (NOX) and can be associated with various physiological processes, such as proliferation, cell signaling, and oxygen homeostasis. In recent years, many studies have indicated that ROS play crucial roles in regulating ultraviolet (UV)-induced photodamage of the skin, including exogenous aging, which accounts for 80% of aging. However, to the best of our knowledge, the detailed signaling pathways, especially those related to the mechanisms underlying apoptosis in which ROS are involved have not been reviewed previously. In this review, we elaborate on the biological characteristics of ROS and its role in regulating UV-induced photodamage of the skin.

Association of air pollution and weather conditions during infection course with COVID-19 case fatality rate in the United Kingdom

Although the relationship between the environmental factors, such as weather conditions and air pollution, and COVID-19 case fatality rate (CFR) has been found, the impacts of these factors to which infected cases are exposed at different infectious stages (e.g., virus exposure time, incubation period, and at or after symptom onset) are still unknown. Understanding this link can help reduce mortality rates. During the first wave of COVID-19 in the United Kingdom (UK), the CFR varied widely between and among the four countries of the UK, allowing such differential impacts to be assessed. We developed a generalized linear mixed-effect model combined with distributed lag nonlinear models to estimate the odds ratio of the weather factors (i.e., temperature, sunlight, relative humidity, and rainfall) and air pollution (i.e., ozone, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]) using data between March 26, 2020 and September 15, 2020 in the UK. After retrospectively time adjusted CFR was estimated using back-projection technique, the stepwise model selection method was used to choose the best model based on Akaike information criteria and the closeness between the predicted and observed values of CFR. The risk of death reached its maximum level when the low temperature (6 °C) occurred 1 day before (OR 1.59; 95% CI 1.52-1.63), prolonged sunlight duration (11-14 h) 3 days after (OR 1.24; 95% CI 1.18-1.30) and increased [Formula: see text] (19 μg/m3) 1 day after the onset of symptom (OR 1.12; 95% CI 1.09-1.16). After reopening, many COVID-19 cases will be identified after their symptoms appear. The findings highlight the importance of designing different preventive measures against severe illness or death considering the time before and after symptom onset.

Vitamin D/Vitamin D receptor mitigates cisplatin-induced acute kidney injury by down-regulating C5aR

Cisplatin (DDP) is a potent chemotherapeutic; however, it can also cause acute kidney injury (AKI). Because of the complexity of the toxicity it induces, few effective methods exist for ameliorating any form of DDP-induced AKI. Recent research has suggested that the complement system is a potential molecular target for such amelioration. In the study here, in vivo (male ICR mice) and in vitro (HK-2 cells) models of DDP-induced AKI were established to investigate the potential therapeutic effects of Vitamin D (VD) against this form of AKI. Endpoints assessed in vivo/in vitro included overall renal function, degree of renal damage, and complement receptor C5aR expression using histology, immunohistochemistry, immunofluorescence, RT-PCR, and Western blots. The data indicated that the use of VD treatment could reduce renal pathological damage along with expression of TNFα, IL-1β, IL-18, and C5aR; however, an over-expression of C5aR weakened the protective effects of VD/VD receptor (VDR) against oxidative damage and inflammatory cell infiltration. Using a luciferase reporter gene assay and ChIP analysis, it was demonstrated that C5aR was transcriptionally inhibited by VDR. In conclusion, VD/VDR could delay DDP-induced AKI by inhibiting the expression of C5aR through transcriptional regulation and reducing the production of downstream pro-inflammatory cytokines. The present study revealed the regulatory mechanism of VD/VDR in acute renal inflammation and provides new insights into its therapeutic function in DDP-induced AKI.

Human skin CD141+ dendritic cells regulate cutaneous immunity via the neuropeptide urocortin 2

Skin immune homeostasis is a multi-faceted process where dermal dendritic cells (DDCs) are key in orchestrating responses to environmental stressors. We have previously identified CD141+CD14+ DDCs as a skin-resident immunoregulatory population that is vitamin-D3 (VitD3) inducible from monocyte-derived DCs (moDCs), termed CD141hi VitD3 moDCs. We demonstrate that CD141+ DDCs and CD141hi VitD3 moDCs share key immunological features including cell surface markers, reduced T cell stimulation, IL-10 production, and a common transcriptomic signature. Bioinformatic analysis identified the neuroactive ligand receptor pathway and the neuropeptide, urocortin 2 (UCN2), as a potential immunoregulatory candidate molecule. Incubation with VitD3 upregulated UCN2 in CD141+ DCs and UVB irradiation induced UCN2 in CD141+ DCs in healthy skin in vivo. Notably, CD141+ DDC generation of suppressive Tregs was dependent upon the UCN2 pathway as in vivo administration of UCN2 reversed skin inflammation in humanized mice. We propose the neuropeptide UCN2 as a novel skin DC-derived immunoregulatory mediator with a potential role in UVB and VitD3-dependent skin immune homeostasis.

Modulatory role of vitamins A, B3, C, D, and E on skin health, immunity, microbiome, and diseases

Disruption of the skin barrier and immunity has been associated with several skin diseases, namely atopic dermatitis (AD), psoriasis, and acne. Resident and non-resident immune cells and the barrier system of the skin are integral to innate immunity. Recent advances in understanding skin microbiota have opened the scope of further understanding the various communications between these microbiota and skin immune cells. Vitamins, being one of the important micronutrients, have been reported to exert antioxidant, anti-inflammatory, and anti-microbial effects. The immunomodulatory action of vitamins can halt the progression of skin diseases, and thus, understanding the immuno-pharmacology of these vitamins, especially for skin diseases can pave the way for their therapeutic potential. At the same time, molecular and cellular markers modulated with these vitamins and their derivatives need to be explored. The present review is focused on significant vitamins (vitamins A, B3, C, D, and E) consumed as nutritional supplements to discuss the outcomes and scope of studies related to skin immunity, health, and diseases.

Low-dose daylight exposure induces nitric oxide release and maintains cell viability in vitro

Any potential positive effects conferred via sunlight exposure have to be carefully balanced against carcinogenic effects. Here we provide evidence UK sunlight exposure upregulates the cardio protectant nitric oxide (NO) within in vitro skin cell lines with negligible increases in DNA damage and cell death at 1 SED, when compared against unexposed samples. The whole of the ultraviolet A (UV-A) spectrum appears to be responsible for NO release, with efficiency higher at exposures closer to shorter UV-A wavelengths and decreasing with wavelength increases. These results support further in vivo work, which could be of benefit for demographics such as the elderly (that exhibit a natural decline in NO bioavailability).

Solar ultraviolet B radiation promotes α-MSH secretion to attenuate the function of ILC2s via the pituitary-lung axis

The immunomodulatory effects of ultraviolet B (UVB) radiation in human diseases have been described. Whether type 2 lung inflammation is directly affected by solar ultraviolet (UV) radiation is not fully understood. Here, we show a possible negative correlation between solar UVB radiation and asthmatic inflammation in humans and mice. UVB exposure to the eyes induces hypothalamus-pituitary activation and α-melanocyte-stimulating hormone (α-MSH) accumulation in the serum to suppress allergic airway inflammation by targeting group 2 innate lymphoid cells (ILC2) through the MC5R receptor in mice. The α-MSH/MC5R interaction limits ILC2 function through attenuation of JAK/STAT and NF-κB signaling. Consistently, we observe that the plasma α-MSH concentration is negatively correlated with the number and function of ILC2s in the peripheral blood mononuclear cells (PBMC) of patients with asthma. We provide insights into how solar UVB radiation-driven neuroendocrine α-MSH restricts ILC2-mediated lung inflammation and offer a possible strategy for controlling allergic diseases.

Can active sun exposure decrease the risk of giant cell arteritis and polymyalgia rheumatica in women?

Objectives

To study if active sun exposure among women affects the risk of developing GCA or PMR in a prospective cohort study with restricted latitudinal variability.

Methods

We linked the response to questions relating to sun exposure from the Melanoma Inquiry in Southern Sweden (MISS) prospective cohort study in women to the risk of developing GCA or PMR. Healthcare data were gathered from the Skåne Healthcare Register (SHR), covering all public healthcare consultations. The direct effect of active sun exposure on the risk of developing GCA or PMR was assessed using Cox proportional hazards models adjusted for covariates based on a directed acyclic graph.

Results

A total of 14 574 women were included in the study; 601 women were diagnosed with GCA or PMR (144 and 457, respectively) during the follow-up time. Women with moderate or high sun exposure were not less likely to develop GCA or PMR compared with women that indicated they avoided sun exposure [hazard ratio (HR) 1.2 (CI 0.9, 1.6) and 1.3 (0.9, 1.9), respectively] when adjusted for diabetes, hyperlipidaemia, hypertension, smoking, obesity and stratified by age. Similar patterns were observed when studying only GCA [HR 1.2 (CI 0.7, 2.3) and 1.3 (0.7, 2.6)] and only PMR [HR 1.3 (CI 0.9, 1.8) and 1.4 (0.9, 2.0)].

Conclusion

Active sun exposure did not affect the risk of developing GCA or PMR in women in a cohort with restricted latitudinal variability.

Post kala-azar dermal leishmaniasis in the Indian sub-continent: challenges and strategies for elimination

Visceral leishmaniasis (VL) is a severe and often fatal form of leishmaniasis caused by Leishmania donovani in the Indian sub-continent. Post Kala-azar Dermal Leishmaniasis (PKDL) is a late cutaneous manifestation of VL, typically occurring after apparent cure of VL, but sometimes even without a prior history of VL in India. PKDL serves as a significant yet neglected reservoir of infection and plays a crucial role in the transmission of the disease, posing a serious threat to the VL elimination program in the Indian sub-continent. Therefore, the eradication of PKDL should be a priority within the current VL elimination program aimed at achieving a goal of less than 1 case per 10,000 in the population at the district or sub-district levels of VL endemic areas. To accomplish this, a comprehensive understanding of the pathogenesis of PKDL is essential, as well as developing strategies for disease management. This review provides an overview of the current status of diagnosis and treatment options for PKDL, highlighting our current knowledge of the immune responses underlying disease development and progression. Additionally, the review discusses the impact of PKDL on elimination programs and propose strategies to overcome this challenge and achieve the goal of elimination. By addressing the diagnostic and therapeutic gaps, optimizing surveillance and control measures, and implementing effective intervention strategies, it is possible to mitigate the burden of PKDL and facilitate the successful elimination of VL in the Indian sub-continent.

Deciphering the role of vitamin D on skin cancers and tumour microenvironment

Skin cancer is a significant health burden being the fourth most common cancer globally and accounts for 6.2% of the total combined cancer cases. However, mortality rates due to skin cancer are less when compared with other cancers, but it is significantly high in the Asian population (43%). DNA mutations and environmental and genetic factors are linked with skin cancer prognosis; however, long-term exposure to ultraviolet (UV) radiation remains one of the leading factors worldwide. Sun exposure is a major environmental risk factor for skin cancers but is also an essential source of vitamin D. On the other hand, studies exploring the relationship between skin cancer risk and vitamin D show mixed, somewhat conflicting results. This study investigates the role of vitamin D and skin carcinogenesis to clarify the associations. Moreover, in addition to suppressing cancer stem cells, it has been observed that vitamin D also regulates tumor initiation and metastasis. In conclusion, the incorporation of well-designed studies on the metabolism of vitamin D from a genotypic and phenotypic perspective is required to understand the intricate mechanisms linking the role of vitamin D in skin carcinogenesis. These new findings will open up new pathways in targeting the disease and lead to novel opportunities for its treatment and cure.

Immunomodulatory actions of vitamin D in various immune-related disorders: a comprehensive review

For many years, vitamin D has been acknowledged for its role in maintaining calcium and phosphate balance. However, in recent years, research has assessed its immunomodulatory role and come up with conflicting conclusions. Because the vitamin D receptor is expressed in a variety of immune cell types, study into the precise role of this molecule in diseases, notably autoimmune disorders, has been made possible. The physiologically activated version of vitamin D also promotes a tolerogenic immunological condition in addition to modulating innate and acquired immune cell responses. According to a number of recent studies, this important micronutrient plays a complex role in numerous biochemical pathways in the immune system and disorders that are associated with them. Research in this field is still relatively new, and some studies claim that patients with severe autoimmune illnesses frequently have vitamin D deficiencies or insufficiencies. This review seeks to clarify the most recent research on vitamin D's immune system-related roles, including the pathophysiology of major disorders.

Association of climatic variables with risk of transmission of influenza in Guangzhou, China, 2005-2021

BACKGROUND

Climatic variables constitute important extrinsic determinants of transmission and seasonality of influenza. Yet quantitative evidence of independent associations of viral transmissibility with climatic factors has thus far been scarce and little is known about the potential effects of interactions between climatic factors on transmission.

OBJECTIVE

This study aimed to examine the associations of key climatic factors with risk of influenza transmission in subtropical Guangzhou.

METHODS

Influenza epidemics were identified over a 17-year period using the moving epidemic method (MEM) from a dataset of N = 295,981 clinically- and laboratory-confirmed cases of influenza in Guangzhou. Data on eight key climatic variables were collected from China Meteorological Data Service Centre. Generalized additive model combined with the distributed lag non-linear model (DLNM) were developed to estimate the exposure-lag-response curve showing the trajectory of instantaneous reproduction number (R_t) across the distribution of each climatic variable after adjusting for depletion of susceptible, inter-epidemic effect and school holidays. The potential interaction effects of temperature, humidity and rainfall on influenza transmission were also examined.

RESULTS

Over the study period (2005-21), 21 distinct influenza epidemics with varying peak timings and durations were identified. Increasing air temperature, sunshine, absolute and relative humidity were significantly associated with lower R_t, while the associations were opposite in the case of ambient pressure, wind speed and rainfall. Rainfall, relative humidity, and ambient temperature were the top three climatic contributors to variance in transmissibility. Interaction models found that the detrimental association between high relative humidity and transmissibility was more pronounced at high temperature and rainfall.

CONCLUSION

Our findings are likely to help understand the complex role of climatic factors in influenza transmission, guiding informed climate-related mitigation and adaptation policies to reduce transmission in high density subtropical cities.

The translational revolution in atopic dermatitis: the paradigm shift from pathogenesis to treatment

Atopic dermatitis (AD) is the most common inflammatory skin disease, and it is considered a complex and heterogeneous condition. Different phenotypes of AD, defined according to the patient age at onset, race, and ethnic background; disease duration; and other disease characteristics, have been recently described, underlying the need for a personalized treatment approach. Recent advancements in understanding AD pathogenesis resulted in a real translational revolution and led to the exponential expansion of the therapeutic pipeline. The study of biomarkers in clinical studies of emerging treatments is helping clarify the role of each cytokine and immune pathway in AD and will allow addressing the unique immune fingerprints of each AD subset. Personalized medicine will be the ultimate goal of this targeted translational research. In this review, we discuss the changes in the concepts of both the pathogenesis of and treatment approach to AD, highlight the scientific rationale behind each targeted treatment and report the most recent clinical efficacy data.

Effect of acute ultraviolet radiation on Galleria mellonella health and immunity

For humans, acute and chronic overexposure to ultraviolet (UV) radiation can cause tissue damage in the form of sunburn and promote cancer(s). The immune-modulating properties of UV radiation and health-related consequences are not well known. Herein, we used the larvae of the wax moth Galleria mellonella, to determine UV-driven changes in cellular components of innate immunity. From immune cell (haemocyte) reactivity and the production of antimicrobial factors, these insects share many functional similarities with mammalian cellular innate immunity. After exposing insects to UVA or UVB for up to two hours, we monitored larval viability, susceptibility to infection, haemolymph (blood) physiology and faecal discharge. Prolonged exposure of larvae to UVB coincided with decreased survival, enhanced susceptibility to bacterial challenge, melanin synthesis in the haemolymph, compromised haemocyte functionality and changes in faecal (bacterial) content. We contend G. mellonella is a reliable in vivo model for assessing the impact of UV exposure at the whole organism and cellular levels.

Research advances in cGAS-stimulator of interferon genes pathway and central nervous system diseases: Focus on new therapeutic approaches

Cyclic GMP-AMP synthase (cGAS), a crucial innate immune sensor, recognizes cytosolic DNA and induces stimulator of interferon genes (STING) to produce type I interferon and other proinflammatory cytokines, thereby mediating innate immune signaling. The cGAS-STING pathway is involved in the regulation of infectious diseases, anti-tumor immunity, and autoimmune diseases; in addition, it plays a key role in the development of central nervous system (CNS) diseases. Therapeutics targeting the modulation of cGAS-STING have promising clinical applications. Here, we summarize the cGAS-STING signaling mechanism and the recent research on its role in CNS diseases.

Chronic skin ultraviolet irradiation induces transcriptomic changes associated with microglial dysfunction in the hippocampus

Recent evidence indicates that ultraviolet (UV) exposure of the skin can affect brain functions such as learning and memory, addictive behavior, and hippocampal neurogenesis. These changes are closely associated with hippocampal function, which plays a pivotal role in learning and memory formation. However, the molecular mechanisms underlying these UV-induced skin-brain interactions remain unclear. To elucidate the molecular signature associated with UV-induced neurobehavioral changes, we analyzed the hippocampal transcriptome in a well-established mouse skin aging model, which showed thickened skin and impaired hippocampal memory. Transcriptome analysis revealed that significantly downregulated genes in UV-irradiated mice are enriched in neuroimmune-related signaling pathways. Furthermore, cell-type analysis showed that DEGs are also enriched in microglia. Consistently, immunofluorescence imaging showed an increased number of Iba1-positive microglia in the hippocampi of UV-irradiated mice. Collectively, our findings highlight that chronic UV irradiation of the skin causes significant changes in the neuroimmune system in the hippocampus, accompanied by microglial dysfunction and cognitive impairment.

Gut microbiota and calcium balance

Microorganisms living on the surface and inside the human body play an important role in the physiological activities of the human body. The largest microecosystem in the human body is the gut microbiome. Calcium disorders are found in many diseases. For example, patients with chronic renal insufficiency present with secondary hyperparathyroidism, which is caused by a calcium imbalance in the body. In addition, calcium dysregulation may affect lipid metabolism in the liver through the calmodulator pathway, leading to cirrhosis, etc. Currently, a considerable number of probiotics have been proven to enhance the body's absorption of calcium. This paper reviews the effects of intestinal flora and related factors such as short-chain fatty acids, estrogen, immune factors and vitamin D on calcium balance.

Vitamin D in Cancer Prevention: Gaps in Current Knowledge and Room for Hope

Intensive epigenome and transcriptome analyses have unveiled numerous biological mechanisms, including the regulation of cell differentiation, proliferation, and induced apoptosis in neoplastic cells, as well as the modulation of the antineoplastic action of the immune system, which plausibly explains the observed population-based relationship between low vitamin D status and increased cancer risk. However, large randomized clinical trials involving cholecalciferol supplementation have so far failed to show the potential of such interventions in cancer prevention. In this article, we attempt to reconcile the supposed contradiction of these findings by undertaking a thorough review of the literature, including an assessment of the limitations in the design, conduct, and analysis of the studies conducted thus far. We examine the long-standing dilemma of whether the beneficial effects of vitamin D levels increase significantly above a critical threshold or if the conjecture is valid that an increase in available cholecalciferol translates directly into an increase in calcitriol activity. In addition, we try to shed light on the high interindividual epigenetic and transcriptomic variability in response to cholecalciferol supplementation. Moreover, we critically review the standards of interpretation of the available study results and propose criteria that could allow us to reach sound conclusions in this field. Finally, we advocate for options tailored to individual vitamin D needs, combined with a comprehensive intervention that favors prevention through a healthy environment and responsible health behaviors.

A “Good Life” for Dairy Cattle: Developing and Piloting a Framework for Assessing Positive Welfare Opportunities Based on Scientific Evidence and Farmer Expertise

Simple Summary

There is increasing appetite to understand how we can provide quality of life to farm animals. A framework to evaluate positive welfare opportunities for dairy cattle was developed using a participatory approach where farmer’s recommendations were integrated into a scientific framework and piloted on farm by vets. When provided with the opportunity to collaborate, farmers and scientists broadly agree on what constitutes “a good life” for dairy cattle and worked together to develop an assessment framework. Farmers did not agree equally on the value of each positive welfare opportunity. However, farmers supported positive welfare assessment as a means of recognition and reward for higher animal welfare, within existing farm assurance schemes, and to justify national and global marketing claims of higher animal welfare.

Abstract

On-farm welfare assessment tends to focus on minimising negative welfare, but providing positive welfare is important in order to give animals a good life. This study developed a positive welfare framework for dairy cows based on the existing scientific literature which has focused on developing positive welfare indicators, and trialled a participatory approach with farmers; refining the framework based on their recommendations, followed by a vet pilot phase on farm. The results revealed that farmers and scientists agree on what constitutes “a good life” for dairy cattle. Farmers value positive welfare because they value their cows’ quality of life, and want to be proud of their work, improve their own wellbeing as well as receive business benefits. For each good life resource, the proportion of farmers going above and beyond legislation ranged from 27 to 84%. Furthermore, barriers to achieving positive welfare opportunities, including monetary and time costs, were not apparently insurmountable if implementation costs were remunerated (by the government). However, the intrinsic value in providing such opportunities also incentivises farmers. Overall, most farmers appeared to support positive welfare assessment, with the largest proportion (50%) supporting its use within existing farm assurance schemes, or to justify national and global marketing claims. Collaborating with farmers to co-create policy is crucial to showcase and quantify the UK’s high welfare standards, and to maximise engagement, relevance and uptake of animal welfare policy, to ensure continuous improvement and leadership in the quality of lives for farm animals.

UVB-Induced Microvesicle Particle Release and Its Effects on the Cutaneous Microenvironment

Ultraviolet B radiation (UVB) has profound effects on human skin that results in a broad spectrum of immunological local and systemic responses and is the major cause of skin carcinogenesis. One important area of study in photobiology is how UVB is translated into effector signals. As the skin is exposed to UVB light, subcellular microvesicle particles (MVP), a subtype of bioactive extracellular vesicles, are released causing a variety of local and systemic immunological effects. In this review, we highlight keratinocyte MVP release in keratinocytes in response to UVB. Specifically, Platelet-activating factor receptor agonists generated by UVB result in MVP released from keratinocytes. The downstream effects of MVP release include the ability of these subcellular particles to transport agents including the glycerophosphocholine-derived lipid mediator Platelet-activating factor (PAF). Moreover, even though UVB is only absorbed in the epidermis, it appears that PAF release from MVPs also mediates systemic immunosuppression and enhances tumor growth and metastasis. Tumor cells expressing PAF receptors can use this mechanism to evade chemotherapy responses, leading to treatment resistance for advanced cancers such as melanoma. Furthermore, novel pharmacological agents provide greater insight into the UVB-induced immune response pathway and a potential target for pharmacological intervention. This review outlines the need to more clearly elucidate the mechanism linking UVB-irradiation with the cutaneous immune response and its pathological manifestations. An improved understanding of this process can result in new insights and treatment strategies for UVB-related disorders from carcinogenesis to photosensitivity.

Unraveling Muscle Impairment Associated With COVID-19 and the Role of 3D Culture in Its Investigation

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been considered a public health emergency, extensively investigated by researchers. Accordingly, the respiratory tract has been the main research focus, with some other studies outlining the effects on the neurological, cardiovascular, and renal systems. However, concerning SARS-CoV-2 outcomes on skeletal muscle, scientific evidence is still not sufficiently strong to trace, treat and prevent possible muscle impairment due to the COVID-19. Simultaneously, there has been a considerable amount of studies reporting skeletal muscle damage in the context of COVID-19. Among the detrimental musculoskeletal conditions associated with the viral infection, the most commonly described are sarcopenia, cachexia, myalgia, myositis, rhabdomyolysis, atrophy, peripheral neuropathy, and Guillain-Barré Syndrome. Of note, the risk of developing sarcopenia during or after COVID-19 is relatively high, which poses special importance to the condition amid the SARS-CoV-2 infection. The yet uncovered mechanisms by which musculoskeletal injury takes place in COVID-19 and the lack of published methods tailored to study the correlation between COVID-19 and skeletal muscle hinder the ability of healthcare professionals to provide SARS-CoV-2 infected patients with an adequate treatment plan. The present review aims to minimize this burden by both thoroughly exploring the interaction between COVID-19 and the musculoskeletal system and examining the cutting-edge 3D cell culture techniques capable of revolutionizing the study of muscle dynamics.

Sex-Specific Environmental Impacts on Initiation and Progression of Multiple Sclerosis

The immunological mechanisms that contribute to multiple sclerosis (MS) differ between males and females. Females are 2–3 times more likely to develop MS compared to males, however the reason for this discrepancy is unknown. Once MS is established, there is a more inflammatory yet milder form of disease in females whereas males generally suffer from more severe disease and faster progression, neural degradation, and disability. Some of these differences relate to genetics, including genetic control of immune regulatory genes on the X-chromosome, as well as immune modulatory properties of sex hormones. Differences in MS development may also relate to how sex interacts with environmental risk factors. There are several environmental risk factors for MS including late-onset Epstein Barr virus infection, low serum vitamin D levels, low UV radiation exposure, smoking, obesity, and lack of physical activity. Most of these risk factors impact males and females differently, either due to biological or immunological processes or through behavioral differences. In this review, we explore these differences further and focus on how the interaction of environmental risk factors with sex hormones may contribute to significantly different prevalence and pathology of MS in males and females.

Vaccine strain affects seroconversion after influenza vaccination in COPD patients and healthy older people

Though clinical guidelines recommend influenza vaccination for chronic obstructive pulmonary disease (COPD) patients and other high-risk populations, it is unclear whether current vaccination strategies induce optimal antibody responses. This study aimed to identify key variables associated with strain-specific antibody responses in COPD patients and healthy older people. 76 COPD and 72 healthy participants were recruited from two Australian centres and inoculated with influenza vaccine. Serum strain-specific antibody titres were measured pre- and post-inoculation. Seroconversion rate was the primary endpoint. Antibody responses varied between vaccine strains. The highest rates of seroconversion were seen with novel strains (36-55%), with lesser responses to strains included in the vaccine in more than one consecutive year (27-33%). Vaccine responses were similar in COPD patients and healthy participants. Vaccine strain, hypertension and latitude were independent predictors of seroconversion. Our findings reassure that influenza vaccination is equally immunogenic in COPD patients and healthy older people; however, there is room for improvement. There may be a need to personalise the yearly influenza vaccine, including consideration of pre-existing antibody titres, in order to target gaps in individual antibody repertoires and improve protection.

Seasonal UV exposure and vitamin D: association with the dynamics of COVID-19 transmission in Europe

Several recent studies have demonstrated that low plasma 25(OH) vitamin D levels are associated with the risk of COVID-19 infection. The primary source of vitamin D production in humans is environmental UV radiation. In many viral respiratory diseases, peak infection rates are observed during winter due to reduced UV exposure and low temperatures. In Europe, the second wave of COVID-19 began early in the winter of 2020. Investigating the impact of seasonal temperature and UV exposure on COVID-19 transmission could thus aid in prevention and intervention. As such, we first performed a comprehensive meta-analysis of all related published literature based on the association between vitamin D and COVID-19, which supported the hypothesis that the low vitamin D level is a critical risk factor for COVID-19 infection. Next, to understand the potential impact of seasonal UV and temperature levels on COVID-19 cases, we analyzed meteorological data and daily COVID-19 cases per million in the populations of 26 European countries. We observed that low temperature, UV index, and cloud-free vitamin D UV dose (UVDVF) levels are negatively correlated with COVID-19 prevalence in Europe. Furthermore, a distributed lag nonlinear model was used to assess the nonlinear delayed effects of individual seasonal factors on COVID-19 cases. Such analysis highlighted the significantly delayed impact of UVDVF on the cumulative relative risk of COVID-19 infection. The findings of this study suggest that low UV exposure can affect the required production of vitamin D in the body, which substantially influences the dynamics of COVID-19 transmission and severity.

The Exposome and Immune Health in Times of the COVID-19 Pandemic

Growing evidence supports the importance of lifestyle and environmental exposures-collectively referred to as the 'exposome'-for ensuring immune health. In this narrative review, we summarize and discuss the effects of the different exposome components (physical activity, body weight management, diet, sun exposure, stress, sleep and circadian rhythms, pollution, smoking, and gut microbiome) on immune function and inflammation, particularly in the context of the current coronavirus disease 2019 (COVID-19) pandemic. We highlight the potential role of 'exposome improvements' in the prevention-or amelioration, once established-of this disease as well as their effect on the response to vaccination. In light of the existing evidence, the promotion of a healthy exposome should be a cornerstone in the prevention and management of the COVID-19 pandemic and other eventual pandemics.

Ultraviolet B Irradiation Alters the Level and miR Contents of Exosomes Released by Keratinocytes in Diabetic Condition

Ultraviolet B (UVB) stimulates the generation of extracellular vesicles, which elicit systemic effects. Here, we studied whether UVB affects the release and microRNA (miR) content of keratinocyte exosomes (EXs) in diabetic conditions. In vitro, we examined the UVB effects on affecting EX release from keratinocyte HaCaT cells (HaCaT‐EX) pretreated with high glucose. HaCaT‐EX functions were evaluated on Schwann cells (SCs). In vivo, UVB‐induced miR change in skin EXs of diabetic db/db mice was analyzed. The miRs of interest were validated in HaCaT‐EXs. We found that: (1) UVB promoted HaCaT‐EX generation in dose‐ and time‐dependent manners; 100 and 1800 J m⁻² of UVB had the most prominent effect and were selected as effective low‐ and high‐fluence UVB in vitro. (2) A total of 13 miRs were differentially expressed >3‐fold in skin EXs in UVB‐treated db/db mice; miR‐126 was the most up‐regulated by low‐fluence UVB. (3) Functional studies revealed that the SC viability was improved by low‐fluence UVB HaCaT‐EXs, while worsened by high‐fluence UVB HaCaT‐EXs. (4) MiR‐126 inhibitor attenuated the effects induced by low‐fluence UVB HaCaT‐EXs. Our data have demonstrated that low‐ and high‐fluence UVBs promote HaCaT‐EX generation but differentially affect exosomal miR levels and functions under diabetic conditions.

Association of lockdowns with the protective role of ultraviolet-B (UVB) radiation in reducing COVID-19 deaths

Nations are imposing unprecedented measures at a large scale to contain the spread of the COVID-19 pandemic. While recent studies show that non-pharmaceutical intervention measures such as lockdowns may have mitigated the spread of COVID-19, those measures also lead to substantial economic and social costs, and might limit exposure to ultraviolet-B radiation (UVB). Emerging observational evidence indicates the protective role of UVB and vitamin D in reducing the severity and mortality of COVID-19 deaths. This observational study empirically outlines the protective roles of lockdown and UVB exposure as measured by the ultraviolet index (UVI). Specifically, we examine whether the severity of lockdown is associated with a reduction in the protective role of UVB exposure. We use a log-linear fixed-effects model on a panel dataset of secondary data of 155 countries from 22 January 2020 until 7 October 2020 (n = 29,327). We use the cumulative number of COVID-19 deaths as the dependent variable and isolate the mitigating influence of lockdown severity on the association between UVI and growth rates of COVID-19 deaths from time-constant country-specific and time-varying country-specific potentially confounding factors. After controlling for time-constant and time-varying factors, we find that a unit increase in UVI and lockdown severity are independently associated with − 0.85 percentage points (p.p) and − 4.7 p.p decline in COVID-19 deaths growth rate, indicating their respective protective roles. The change of UVI over time is typically large (e.g., on average, UVI in New York City increases up to 6 units between January until June), indicating that the protective role of UVI might be substantial. However, the widely utilized and least severe lockdown (governmental recommendation to not leave the house) is associated with the mitigation of the protective role of UVI by 81% (0.76 p.p), which indicates a downside risk associated with its widespread use. We find that lockdown severity and UVI are independently associated with a slowdown in the daily growth rates of cumulative COVID-19 deaths. However, we find evidence that an increase in lockdown severity is associated with significant mitigation in the protective role of UVI in reducing COVID-19 deaths. Our results suggest that lockdowns in conjunction with adequate exposure to UVB radiation might have even reduced the number of COVID-19 deaths more strongly than lockdowns alone. For example, we estimate that there would be 11% fewer deaths on average with sufficient UVB exposure during the period people were recommended not to leave their house. Therefore, our study outlines the importance of considering UVB exposure, especially while implementing lockdowns, and could inspire further clinical studies that may support policy decision-making in countries imposing such measures.

The Effects of Vitamin D on Immune System and Inflammatory Diseases

Immune cells, including dendritic cells, macrophages, and T and B cells, express the vitamin D receptor and 1α-hydroxylase. In vitro studies have shown that 1,25-dihydroxyvitamin D, the active form of vitamin D, has an anti-inflammatory effect. Recent epidemiological evidence has indicated a significant association between vitamin D deficiency and an increased incidence, or aggravation, of infectious diseases and inflammatory autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis. However, the impact of vitamin D on treatment and prevention, particularly in infectious diseases such as the 2019 coronavirus disease (COVID-19), remains controversial. Here, we review recent evidence associated with the relationship between vitamin D and inflammatory diseases and describe the underlying immunomodulatory effect of vitamin D.

Beyond the Skin Plaques: Psoriasis and Its Cardiovascular Comorbidities

Psoriasis, a widely prevalent chronic disease of the skin and joints, has long been associated with far-reaching systemic ramifications and decreased quality of life. However, psoriasis is largely underdiagnosed and insufficiently treated. Classical risk factors predisposing to cardiovascular diseases, such as hypertension, diabetes, metabolic syndrome, and dyslipidemia, have been noted in patients with mild and severe psoriasis. Furthermore, the magnitude of the cardiovascular comorbidity and the need to screen for risk factors has often been ignored while considering the management options for psoriasis. This article has reviewed the cardiovascular implications of psoriasis from the shared pathogenesis behind these two diseases to the increased incidence of cardiovascular events, such as myocardial infarction, stroke, and other causes of vascular mortality. Additionally, the therapeutic targets of common inflammatory pathways, such as those involving tumor necrosis factor α (TNF-α), interleukin-12/interleukin-23 (IL-12/IL-23), and helper T cells 17 (Th17), have been discussed with an emphasis on their efficacy in controlling psoriasis and its cardiovascular consequences.

Randomized trial of vitamin D versus placebo supplementation on markers of systemic inflammation in hypertensive patients

BACKGROUND AND AIMS

Animal and cell models indicated that vitamin D modulates inflammatory activity, which is considered relevant in the pathogenesis of arterial hypertension and cardiovascular diseases. We therefore aimed to investigate the effect of vitamin D supplementation on systemic markers of inflammation in a cohort of hypertensive patients.

METHODS AND RESULTS

The Styrian Vitamin D Hypertension Trial is a single-centre, double-blind, placebo-controlled study conducted from 2011 to 2014 in Austria. We enrolled 200 study participants with arterial hypertension and 25-hydroxy-vitamin-D (25(OH)D) concentration below 30 ng/mL. Study participants were randomized to receive either 2800 IU of vitamin D₃ per day or placebo for 8 weeks. The present investigation is a post-hoc analysis using analysis of co-variance (ANCOVA). Outcome measures were biomarkers of inflammation including CRP, leukocytes including subtypes and leukocyte-to-lymphocyte ratio, leucine and kynurenic acid. A total of 187 participants (mean age 60.1 ± 11.3years; 47% women; mean baseline 25(OH)D 21.1 ± 5.6 ng/mL) completed the trial. ANCOVA revealed a mean treatment effect for none of the respective outcomes and no significant results were detected in various subgroup analyses.

CONCLUSION

Vitamin D₃ supplementation in hypertensive patients with insufficient 25(OH)D concentrations has no significant effect on lowering markers of systemic inflammation. Further studies investigating the effect of vitamin D on other inflammatory pathways and in populations with severe vitamin D deficiency and a significant inflammatory burden are required.

REGISTRATION

ClinicalTrials.gov Identifier: NCT02136771; EudraCT No. 2009-018,125-70. Start Date: 2011-04-06.

Seasonal variability of serum 25-hydroxyvitamin D on multiple sclerosis onset

Vitamin D deficiency is associated with an increased risk of multiple sclerosis (MS). However, its effect on the age of disease onset remains unclear. This study examines the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and age of first symptom onset among recently diagnosed MS patients. Serum 25(OH)D was measured from forty MS patients sampled near disease onset. After correcting seasonal variability, the association between 25(OH)D levels, along with other clinical measures such as IgG index, and age at MS onset was examined using multivariable linear regression. Serum 25(OH)D was not correlated with age at onset (P > 0.5). We observed bias among previously reported associations between 25(OH)D and MS disease measures resulting from non-random distribution of sampling by season. After correcting for seasonal 25(OH)D and other clinical measures, only CSF IgG index remained significantly associated with age at disease onset (β = − 5.35, P = 0.028). In summary, we observed no association between age at onset and serum 25(OH)D levels but observed a negative correlation with CSF IgG index, although this will require further investigation.

MR1-dependent immune surveillance of the skin contributes to pathogenesis and is a photobiological target of UV light therapy in a mouse model of atopic dermatitis

BACKGROUND

Mucosal-associated invariant T (MAIT) cells are unconventional T cells which recognize microbial metabolites presented by the major histocompatibility complex class I-related molecule MR1. Although MAIT cells have been shown to reside in human and murine skin, their contribution to atopic dermatitis (AD), an inflammatory skin disease associated with barrier dysfunction and microbial translocation, has not yet been determined.

METHODS

Genetic deletion of MR1 and topical treatment with inhibitory MR1 ligands, which result in the absence and functional inhibition of MAIT cells, respectively, were used to investigate the role of MR1-dependent immune surveillance in a MC903-driven murine model of AD.

RESULTS

The absence or inhibition of MR1 arrested AD disease progression through the blockade of both eosinophil activation and recruitment of IL-4- and IL-13-producing cells. In addition, the therapeutic efficacy of phototherapy against MC903-driven AD could be increased with prior application of folate, which photodegrades into the inhibitory MR1 ligand 6-formylpterin.

CONCLUSION

We identified MAIT cells as sentinels and mediators of cutaneous type 2 immunity. Their pathogenic activity can be inhibited by topical application or endogenous generation, via phototherapy, of inhibitory MR1 ligands.

Higher ultraviolet radiation during early life is associated with lower risk of childhood type 1 diabetes among boys

Population-level ecological studies show type 1 diabetes incidence is inversely correlated with ambient ultraviolet radiation (UVR) levels. We conducted a nested case-control study using administrative datasets to test this association at the individual level. Cases (n = 1819) were children born in Western Australia (WA) from 1980-2014, diagnosed with type 1 diabetes at ≤ 16 years. Controls (n = 27,259) were randomly selected from all live births in WA, matched to cases by sex and date of birth. Total ambient erythemal ultraviolet radiation (UVR) doses for each trimester of pregnancy and first year of life were estimated for each individual, using daily NASA satellite data that were date- and geographically-specific. Conditional logistic regression tested the association between UVR dose and case-control status. Type 1 diabetes risk was 42% lower in boys of mothers with third-trimester UVR dose in the highest (compared to the lowest) quartile (p = 0.04). Higher UVR in the first year of life was associated with lower type 1 diabetes risk among boys (p = 0.01). UVR dose was not associated with type 1 diabetes risk in girls. Higher UVR in late pregnancy and early life appear to interact with sex-specific factors to lower type 1 diabetes risk among boys in Western Australia.

Does Climate Play Any Role in COVID-19 Spreading?-An Australian Perspective

Compared to other countries, the COVID-19 pandemic did not severely affect Australia as measured by total deaths until mid-2021. Though a substantial number of daily confirmed cases (up to 698) were reported during the second wave, most of them were from the southern state of Victoria. This study examined the possible correlations between climate variables and the number of daily confirmed COVID-19 cases in Victoria, Australia, from 25 January to 31 October 2020. Appropriate regression models and cross-correlation diagnostics were used to examine the effect of temperature, rainfall, solar exposure, and ultraviolet index (UVI) with the number of daily confirmed cases. Significant positive associations were identified for solar exposure and maximum and average UVI for confirmed cases one and 19 days later. Negative associations for these variables were found for confirmed cases five days later. Minimum temperature had a significant negative correlation one day later and a positive effect 21 days later. No significant correlation was found for maximum temperature and rainfall. The most significant relationships were found for confirmed cases 19 days after changes in the meteorological variables. A 1% increase in solar exposure, maximum UVI, and average UVI was associated with a 0.31% (95% CI: 0.13 to 0.51), 0.71% (95% CI: 0.43 to 0.98), and 0.63% (95%CI: 0.20 to 1.61) increase 19 days later in the number of confirmed cases, respectively. The implications of these results can be used in the public health management of any possible future events in Australia. It also highlights the significance of considering the climatic variables and seasonality in all kinds of epidemics and pandemics.

Vitamin D and the risk for cancer: A molecular analysis

Uncontrolled overgrowth of cells, such as in cancer, is an unavoidable risk in life that affects nearly every second individual in industrialized countries. However, in part this risk can be controlled through lifestyle adjustments, such as the avoidance of smoking, unhealthy diet, obesity, physical inactivity and other cancer risk factors. A low vitaminD status is a risk in particular for cancers of colon, prostate, breast and leukocytes. VitaminD₃ is produced non-enzymatically, when the cholesterol precursor 7-dehydrocholesterol is exposed to UV-B from sunlight, i.e., all cholesterol synthesizing species, including humans, can make vitaminD₃. VitaminD endocrinology started some 550million years ago, when the metabolite 1α,25-dihydroxyvitaminD₃ and the transcription factor vitaminD receptor teamed up for regulating the expression of hundreds of target genes in a multitude of different tissues and cell types. Initially, these genes were focused on the control of energy homeostasis, which later also involved energy-demanding innate and adaptive immunity. Rapidly growing cells of the immune system as well as those of malignant tumors rely on comparable genes and pathways, some of which are modulated by vitaminD. Accordingly, vitaminD has anti-cancer effects both directly via controling the differentiation, proliferation and apoptosis of neoplastic cells as well as indirectly through regulating immune cells that belong to the microenvironment of malignant tumors. This review discusses effects of vitaminD on the epigenome and transcriptome of stromal and tumor cells, inter-individual variations in vitaminD responsiveness and their relation to the prevention and possible therapy of cancer.

Vitamin d and leishmaniasis: Neither seasonal nor risk factor in canine host but potential adjuvant treatment through cbd103 expression

Vitamin D (VitD) deficiency has been shown to be a risk factor for a plethora of disorders. We have shown that dogs with clinical leishmaniasis presented lower VitD serum levels than non-infected dogs, and even lower than those with asymptomatic infection. However, if VitD deficiency is a risk factor to develop clinical leishmaniasis remains to be answered. It is also unknown if VitD participates in Leishmania control. First, we retrospectively analysed VitD concentration in serum samples from 36 healthy dogs collected in different periods of the year concluding that there isn't a seasonal variation of this vitamin in dogs. We also included 9 dogs with clinical leishmaniasis and 10 non-infected healthy dogs, in which we measured VitD levels at the beginning of the study, when all dogs were negative for serology and qPCR, and 1 year later. Whereas non-infected dogs showed no change in VitD levels along the study, those developing clinical leishmaniasis showed a significant VitD reduction at the end of the study (35%). When we compared VitD concentration between the two groups at the beginning of the study, no differences were detected (43.6 (38-59) ng/mL, P = 0.962). Furthermore, an in vitro model using a canine macrophage cell line proved that adding active VitD leads to a significant reduction in L. infantum load (31.4%). Analyzing expression of genes related to VitD pathway on primary canine monocytes, we showed that CBD103 expression was significantly enhanced after 1,25(OH)2D addition. Our results show that VitD concentration is neither seasonal nor a risk factor for developing canine leishmaniasis, but it diminishes with the onset of clinical disease suggesting a role in parasitic control. Our in vitro results corroborate this hypothesis and point out that VitD regulates infection through CBD103 expression. These results open the possibility for studies testing VitD as an adjuvant in leishmaniasis therapy.

Influence of Ethnicities and Skin Color Variations in Different Populations: A Review

BACKGROUND

In the world scientific tradition, skin color is the primary physical characteristic used to divide humans into groups. Human skin has a wide range of tones and colors, which can be seen in a wide range of demographic populations. Many factors influence the color of people's skin, but the pigment melanin is by far the most important. Melanin is produced by cells called melanocytes in the skin and is the primary determinant of skin color in people with darker skin. Indeed, >150 genes have now been identified as having a direct or indirect effect on skin color. Vitamin D has recently been discovered to regulate cellular proliferation and differentiation in a variety of tissues, including the skin. The mechanisms through which the active vitamin D metabolite 1,25 dihydroxyvitamin D3 (or calcitriol) affects keratinocyte development are numerous and overlap with the mechanisms by which calcium influences keratinocyte differentiation. Ultraviolet (UV) is the most major modifiable risk factor for skin cancer and many other environmental-influenced skin disorders when it is abundant in the environment. Although the UV component of sunlight is known to cause skin damage, few researches have looked at the impact of non-UV solar radiation on skin physiology in terms of inflammation, and there is less information on the role of visible light in pigmentation.

SUMMARY

The quantity and quality of melanin are regulating by the expression of genes. The enzyme tyrosinase is primarily responsible for the genetic mechanism that controls human skin color. Genetics determines constitutive skin color, which is reinforced by facultative melanogenesis and tanning reactions. High quantities of melanin and melanogenic substances are typically accepted in darker skin to protect against UV radiation-induced molecular damage. Previous research has proposed that skin color variation is caused by a dynamic genetic mechanism, contributing to our understanding of how population demographic history and natural selection shape human genetic and phenotypic diversity. However, the most significant ethnic skin color difference is determined by melanin content. This current review aimed to assess the influence of skin color variations in skin structure and functions as well as difference in dermatological disease patterns. Also, this article reviewed several cases of skin color adaptation in different populations. Key Messages: Skin color impacts the composition and activity. Therefore, the contrast of dermatological ailments between distinct race-related categories is remarkable. Skin color adaptation is a challenging procedure. Refinement of skin color is an age-old craving of humans with ever-evolving drifts.

Higher Sun Exposure in the First Trimester Is Associated With Reduced Preterm Birth; A Scottish Population Cohort Study Using Linked Maternity and Meteorological Records

Background: Preterm birth (birth at <37 weeks gestation) is the leading cause of death in children under 5-years-old, and prevention is a global public health issue. Seasonal patterns of preterm birth have been reported, but factors underlying this have been poorly described. Sun exposure is an important environmental variable that has risks and benefits for human health, but the effects of sun exposure on pregnancy duration and preterm birth are unknown. Objectives: To determine the association between available sun exposure and preterm birth. Methods: We performed a population-based data-linkage study of 556,376 singleton births (in 397,370 mothers) at or after 24 weeks gestation, in Scotland between 2000 and 2010. Maternity records were linked to available sun exposure from meteorological records, by postcode. Logistic regression analysis was used to explore the relationship between available sunshine and preterm birth at <37 weeks gestation. Exploratory analyses included a subgroup analysis of spontaneous and indicated preterm births and a sibling analysis in sib pairs discordant for preterm birth. Results: The rate of preterm birth was 6% (32,958/553,791 live births). Increased available sun exposure in the first trimester of pregnancy was associated with a reduced risk of preterm birth, with evidence of a dose-response. Compared with the lowest quartile of sun exposure, the highest quartile of sun exposure was associated with a reduced odds ratio (OR) of preterm birth of 0.90 (95% Confidence Interval (CI) 0.88-0.94 p < 0.01) on univariable analysis and OR of 0.91 (95% CI 0.87, 0.93 p < 0.01) after adjustment for second trimester sunlight exposure, parity, maternal age, smoking status, and deprivation category. No association was seen between preterm birth and second trimester available sun exposure or combined first and second trimester exposure. Similar patterns were seen on sibling analysis and within both the indicated and spontaneous preterm subgroups. Discussion: Available sun exposure in the first trimester of pregnancy is associated with a protective effect on preterm birth <37 weeks gestation. This opens up new mechanisms, and potential therapeutic pathways, for preterm birth prevention.

Limited evidence for the role of environmental factors in the unusual peak of influenza in Brisbane during the 2018-2019 Australian summer

OBJECTIVE

To explore the contribution of environmental factors in the unusual pattern of influenza activity observed in Brisbane, Australia during the summer of 2018-2019.

METHODS

Distributed lag nonlinear models (DLNMs) were used to estimate the effect of environmental factors on weekly influenza incidence in Brisbane. Next generation sequencing was then employed to analyze minor and majority variants in influenza strains isolated from Brisbane children during this period.

RESULTS

There were limited marked differences in the environmental factors observed in Brisbane between the 2018-2019 summer period and the same period of the proceeding years, with the exception of significant reduction in rainfall. DLNM showed that reduced rainfall in Brisbane (at levels consistent with the 2018-2019 period) correlated with a dramatic increase in the relative risk of influenza. Sulfur dioxide (SO₂) levels were also increased in the 2018-2019 period, although these levels did not correlate with an increased risk of influenza. Sequencing of a limited number of pediatric influenza virus strains isolated during the 2018-2019 showed numerous mutations within the viral HA.

CONCLUSIONS

Taken together, these data suggest a limited role for key environmental factors in the influenza activity observed in Brisbane, Australia during the summer of 2018-2019. One alternative explanation may that viral factors, in addition to other factors not studied herein, contributed to the unusual influenza season. Our findings provide fundamental information that may be beneficial to a better understanding of the seasonal trends of influenza virus.

Role of meteorological factors in the transmission of SARS-CoV-2 in the United States

Improved understanding of the effects of meteorological conditions on the transmission of SARS-CoV-2, the causative agent for COVID-19 disease, is needed. Here, we estimate the relationship between air temperature, specific humidity, and ultraviolet radiation and SARS-CoV-2 transmission in 2669 U.S. counties with abundant reported cases from March 15 to December 31, 2020. Specifically, we quantify the associations of daily mean temperature, specific humidity, and ultraviolet radiation with daily estimates of the SARS-CoV-2 reproduction number (Rt) and calculate the fraction of Rt attributable to these meteorological conditions. Lower air temperature (within the 20-40 °C range), lower specific humidity, and lower ultraviolet radiation were significantly associated with increased Rt. The fraction of Rt attributable to temperature, specific humidity, and ultraviolet radiation were 3.73% (95% empirical confidence interval [eCI]: 3.66-3.76%), 9.35% (95% eCI: 9.27-9.39%), and 4.44% (95% eCI: 4.38-4.47%), respectively. In total, 17.5% of Rt was attributable to meteorological factors. The fractions attributable to meteorological factors generally were higher in northern counties than in southern counties. Our findings indicate that cold and dry weather and low levels of ultraviolet radiation are moderately associated with increased SARS-CoV-2 transmissibility, with humidity playing the largest role.

Physical Activity during COVID-19 Lockdown in Italy: A Systematic Review

The recent COVID-19 pandemic has imposed a general lockdown in Italy, one of the most affected countries at the beginning of the outbreak, between 9 March and 3 May 2020. As a consequence, Italian citizens were confined at home for almost two months, an unprecedented situation, which could have negative effects on both psychological and physical health. The aim of this study was to review the published papers concerning the effects of the lockdown on physical activity and the consequences on general health. As expected, most studies highlighted a significant reduction in the amount of performed physical activity compared to before lockdown, in both the general population and in individuals with chronic conditions. This fact had negative consequences on both general health, in terms of increased body mass, and on specific chronic conditions, especially obesity and neurological diseases.