Shedding new light on the role of the sunshine vitamin D for skin health: the lncRNA-skin cancer connection

Seasonal Variations in 25-Hydroxyvitamin D Levels among Pediatric Patients Attending the Healthcare Centre

Vitamin D plays an essential role in maintaining bone density, building the immune system, and regulating cell growth alongside other key biological functions. Limited data are available about the seasonal variation in vitamin D levels in the pediatric population in Saudi Arabia. This study aimed to investigate the seasonal influence on the pediatric circulating levels of 25(OH)D. A total of 1790 pediatric outpatients who visited the University healthcare centre were included in this study. Overall, there was a noticeably high prevalence (69%) of both combined 25(OH)D deficiency and insufficiency. The highest mean serum concentration of 25(OH)D was recorded in summer (29 ng/mL) and autumn (27 ng/mL). The deficient and insufficient categories were predominant, accounting for 33% and 36%, respectively. Comparable patterns were recorded during autumn, winter, and spring. Interestingly, the 25(OH)D level was significantly associated with the four seasons (p = 0.001), with females having a higher prevalence of 25(OH)D deficiency in the spring and summer than males. Furthermore, only in autumn and winter, we found a significant association between gender and 25(OH)D status (p < 0.001 for both). Another association between nationality and the circulating levels 25(OH)D was found during autumn and winter (p < 0.001 and p = 0.01), respectively. In all seasons, age had a negative impact on serum (OH)D levels. However, this relationship was statistically significant (p < 0.05) only in summer, autumn, and winter. Gender was a significant predictor, with 25(OH)D levels in autumn and winter and an odds ratio of 1.67 in autumn and 2 in winter, indicating that being men had a positive influence on circulating 25(OH)D levels. There were highly significant differences in 25(OH)D concentrations among different age categories. The Saudi population experiences low levels of vitamin D, particularly in autumn and winter periods. This study showed that seasonality, age category, nationality, and gender influence vitamin D status, suggesting the need for tailored intervention and monitoring of 25(OH)D status to reach adequate levels of vitamin D. Healthcare practitioners and policymakers may consider the interplay between age, nationality, gender, and seasonal variations when addressing vitamin D status and a targeted supplementation approach for high-risk groups that may develop health issues.

A Retrospective Chart Review Evaluating Changes in 25-Hydroxyvitamin D Levels among Patients Attending the University Healthcare Centre during the COVID-19 Pandemic

COVID-19-pandemic-related home confinement aids in limiting the spread of the virus but restricts exposure to sunlight, thereby possibly affecting 25(OH)D concentrations. This study aimed to investigate the effect of lockdown measures on 25(OH)D levels in outpatients visiting the healthcare centre over a period of two years. In this retrospective chart review, outpatients who visited a university healthcare centre for a health check-up over a period of two years were included. The patients' 25(OH)D serum levels and status were compared before, during, and after the lockdown periods. A total of 7234 patients were included in this study, with a mean age of 34.66 ± 16.78. The overall prevalence of 25(OH)D insufficiency, deficiency and sufficiency was 33.8%, 30.7% and 35.4%, respectively. The proportion of individuals with 25-(OH) D deficiency prior to lockdown was 29% and this proportion increased in the lockdown and post-lockdown periods to 31.1% and 32%, respectively. Although gender was less likely to have an impact on the 25 (OH) D level during the lockdown period (p = 0.630), we found an association between gender and 25 (OH) D status in the pre-lockdown and post-lockdown periods (p < 0.001 and p < 0.001, respectively). Another association between nationality and 25 (OH)D levels was found before, during and after the lockdown periods (p < 0.001). In addition, the youngest population, aged between 1 and 14, was strongly affected by the home confinement. Age had a positive and significant (p < 0.05) effect on 25 (OH) D status regardless of the different periods. Moreover, in the pre-lockdown period, male outpatients had 1.56 chance of having a sufficient level of 25 (OH)D. However, during the lockdown period, this chance decreased to 0.85 and then increased to 0.99 after the lockdown period. We found no statistically significant difference in the mean serum concentrations or in the prevalence of vitamin D insufficiency when we compared values from before, during and immediately after the COVID-19 lockdown period. However, there was a generally increased prevalence of vitamin D insufficiency in our study population. Another association between gender, nationality and age groups with 25(OH) D was found. Regular exposure to UVR is recommended for maintaining adequate vitamin D levels and to prevent vitamin D deficiency. Further research is needed to determine the best indications for vitamin D supplementation if confinement periods are extended and to consider the potential health consequences of prolonged confinement periods not only on vitamin D status but also on overall public health. The findings of this study may be considered by stakeholders for a targeted supplementation approach for risk groups.

Vitamin D Receptor Promotes Global Nucleotide Excision Repair by Facilitating XPC Dissociation from Damaged DNA

Vitamin D receptor (VDR) is important for normal DNA repair, although the mechanism by which it acts is unclear. After focal UV irradiation to create subnuclear spots of DNA damage, epidermal keratinocytes from VDR-null mice as well as human epidermal keratinocytes depleted of VDR with small interfering RNA removed pyrimidine-pyrimidone (6-4) photoproducts more slowly than control cells. Costaining with antibodies to XPC, the DNA damage recognition sensor that initiates nucleotide excision repair, showed that XPC rapidly accumulated at spots of damage and gradually faded in control human keratinocytes. In VDR-depleted keratinocytes, XPC associated with DNA damage with comparable efficiency; however, XPC's dissociation dynamics were altered so that significantly more XPC was bound and retained over time than in control cells. The XPF endonuclease, which acts subsequently in nucleotide excision repair, bound and dissociated with comparable kinetics in control and VDR-depleted cells, but the extent of binding was reduced in the latter. These results as well as kinetic modeling of the data suggest that VDR's importance in the repair of UV-induced DNA damage is mediated in part by its ability to facilitate the dissociation of XPC from damaged DNA for the normal recruitment and assembly of other repair proteins to proceed.

Vitamin Excess and Deficiency

The published literature supports the high prevalence of supplement use in children and adolescents in the United States. Pediatricians today are faced with questions from parents and patients about the benefits, safety, efficacy, and correct dose of vitamins and minerals. In this article, we review 7 vitamins with the most clinical relevance as judged by abundance in food, risks and symptoms of deficiency, and potential for toxicity. Specifically, we focus on possible clinical scenarios that can be indicative of nutritional deficiency. We synthesize and summarize guidelines from nutrition experts, various medical societies, the World Health Organization, and the American Academy of Pediatrics.

Long non-coding RNA Myd88 promotes growth and metastasis in hepatocellular carcinoma via regulating Myd88 expression through H3K27 modification

Enhanced Myd88 expression has been found in various parenchymal tumors especially in hepatocellular carcinoma with little mechanism of its upregulation known. A lot of long non-coding RNAs are reported to regulate the protein-coding genes which have location association through various mechanisms. In our study we confirmed a new long non-coding RNA Myd88 aberrant upregulated in HCC located upstream of Myd88 and verified a positive regulation relationship between them indicating that Lnc-Myd88 might participate in the enhanced expression of Myd88 in HCC. The gain- and loss-of-function analysis revealed that Lnc-Myd88 could promote the proliferation and metastasis of HCC both in vitro and in vivo. In addition, ChIP assays demonstrated that Lnc-Myd88 might increase Myd88 expression through enhancing H3K27Ac in the promoter of Myd88 gene, thus resulting in the activation of both NF-κB and PI3K/AKT signal pathways. In conclusion, we proposed that Lnc-Myd88 might serve as a novel diagnosis and therapeutic target for HCC.

Insulin-like growth factor-I and UVB photoprotection in human keratinocytes

Ultraviolet radiation (UVR), in particular the UVB spectrum, is a risk factor for skin cancer development. The generation and accumulation of UVB-induced genetic mutations are fundamental premalignant events. Keratinocyte interactions between other cutaneous cell populations and the surrounding microenvironment determine cell fate and acute photoresponses. In this study, the importance of the insulin-like growth factor (IGF) system, in particular the insulin-like growth factor-I (IGF-I), on influencing key processes in the keratinocyte acute photoresponse was investigated. Exogenous IGF-I and other growth factors present in dermal fibroblast-conditioned media (CM) were found to significantly enhance keratinocyte survival following UVB irradiation in vitro. This pretreatment was also shown to cause a shift in the expression levels of various DNA damage response proteins. Consequently, this was associated with accelerated rates of UVB-induced cyclobutane pyrimidine dimer removal in these samples. Finally, activation of the IGF system influenced cell cycle progression in UVB-irradiated keratinocytes. Taken together, these results highlight the importance of the IGF signalling network in initiating the repair of potentially mutagenic DNA damage in human keratinocytes. The dysregulation of these processes may therefore have significant implications in the aetiology of skin cancers and other cutaneous diseases.

Ultraviolet light exposure, skin cancer risk and vitamin D production

The danger of overexposure to solar ultraviolet radiation has been widely reviewed since the 1980s due to the depletion of the ozone layer. However, the benefits of mild exposure of the skin to ultraviolet (UV) light have not been widely investigated. Numerous reports have demonstrated that an association exists between low light exposure to the sun, non-melanoma skin cancer and a lack of vitamin D synthesis. As vitamin D synthesis in the body depends on skin exposure to UVB radiation from the sun (wavelength, 290-320 nm), experimental measurements for this type of solar radiation are important. The present study analyzed data obtained from a laboratory investigating UV radiation from the sun at the University of Tarapacá (Arica, Chile), where systematic experimental UVB measurements had been performed using a calibrated biometer instrument since 2006. These data were compared with skin cancer data from the local population. The results demonstrated that the incidence of skin cancer systematically increased from 7.4 to 18.7 in men and from 10.0 to 21.7 in women between 2000 and 2006 in Arica, respectively; this increase may be due to multiple factors, including the lack of adequate levels of vitamin D in risk groups such as post-menopausal women and senior age. This marked increase may also be due to the high levels of UV radiation measured in this region throughout the year. However, it is not certain that the local population has adequate vitamin D levels, nor that their skin has been predominantly exposed to artificial light that does not allow adequate vitamin D synthesis. Thus, the current study presents the association between skin type IV, the time to induce solar erythema and the time required to produce 1,000 international units of vitamin D.

Serum level of vitamin D3 in cutaneous melanoma

OBJECTIVE

To compare the level of vitamin D3 in cutaneous melanoma patients, with or without disease activity, with reference values and with patients from a general hospital.

METHODS

The serum levels of vitamin D3 were measured in cutaneous melanoma patients, aged 20 to 88 years, both genders, from January 2010 to December 2013. The samples from the general group were processed at Hospital Israelita Albert Einstein (control group). Data analysis was performed using the Statistics software.

RESULTS

A total of 100 patients were studied, 54 of them men, with mean age of 54.67 years, and 95 Caucasian. Out of these 100 patients, 17 had active disease. The average levels of vitamin D3 in the melanoma patients were lower than the level considered sufficient, but above the average of the control group. Both groups (with or without active disease) of patients showed a similar distribution of vitamin D3 deficiency.

CONCLUSION

Vitamin D3 levels in melanoma patients were higher than those of general patients and lower than the reference level. If the reference values are appropriate, a large part of the population had insufficient levels of vitamin D, including those with melanoma, or else, this standard needs to be reevaluated. No difference in vitamin D3 levels was found among melanoma patients with or without active disease. More comprehensive research is needed to assess the relation between vitamin D and melanoma.