Estimation of individual cumulative ultraviolet exposure using a geographically-adjusted, openly-accessible tool

9-Hydroxyoctadecadienoic acid plays a crucial role in human skin photoaging

Human skin is regularly exposed to ultraviolet (UV) rays from sunlight, leading to photoaging, which differs from intrinsic aging. Although the acute effects of UV exposure have been extensively studied, limited research has addressed the long-term consequences of chronic UV exposure. This study aimed to investigate the underlying causes of chronic photoaging. A questionnaire-based assessment of sunlight exposure was conducted among volunteers in their 20s and 50s, and the stratum corneum of their skin was analyzed for bioactive lipid content. Volunteers were categorized into low and high UV exposure groups based on the questionnaire scores. The analysis results revealed a significant increase in 9-hydroxyoctadecadienoic acid (9-HODE) levels in the skin of individuals in their 50s with high UV exposure. However, UV exposure did not affect 9-HODE levels in the skin of individuals in their 20s. In vitro experiments further indicated that 9-HODE contributes to chronic inflammation, pigmentary changes, and extracellular matrix alterations during photoaging. Specifically, 9-HODE stimulated cytokine production [interleukin-6 (IL6), IL8, and granulocyte-macrophage colony-stimulating factor (GM-CSF)] and reduced dickkopf-1 (DKK1) production in keratinocytes. In fibroblasts, 9-HODE stimulated matrix metalloproteinase-1 (MMP1) and MMP3 production while reducing collagen I (COL1) production. The expression of G2A, the receptor for 9-HODE, was also confirmed in fibroblasts, suggesting that 9-HODE exerts its effects via G2A, as observed in keratinocytes. Overall, these findings indicate that 9-HODE is a mediator of chronic photoaging and highlight its potential significance in photoaging prevention.

The epidemiology of skin cancer by UV index: cross-sectional analysis from the 2019 behavioral risk factor surveillance survey

The extent to which the Ultraviolet (UV) index is associated with the prevalence of melanoma and keratinocyte cancer in the United States is not clear. We conducted a cross-sectional study using the Center for Disease Control and Prevention's (CDC) 2019 Behavioral Risk Factor Surveillance System (BRFSS) telephone interview survey to investigate the epidemiology of skin cancer in the US including age, household income, education, and marital and employment status. Of non-Hispanic white respondents, 9.6% (N = 29,925) reported a being told of a skin cancer diagnosis. The prevalence of skin cancer was significantly higher in high UV (> / = 8) states (11.8%, N = 36,575) than in medium UV (6-7) (9.0%, N = 27,812) and lower UV (< / = 5) (7.8%, N = 24,083) states (p < .0001). Respondents from a medium UV or high UV state had higher odds (1.21 [1.15-2.27], 1.55[1.47-1.63], respectively) of reporting a skin cancer diagnosis than those from a low UV state. The association of UV index with lifetime skin cancer prevalence reinforces the importance of educating patients on preventive practices such as avoidance of tanning beds and usage of UV protection with clothing and sunscreen.

Racial and Ethnic Diversity of US Participants in Clinical Trials for Acne, Atopic Dermatitis, and Psoriasis: A Comprehensive Review

An increasing body of literature describes underreporting of race and ethnicity, and overrepresentation of White individuals in clinical trials. We aimed to evaluate the racial and ethnic diversity of US participants in clinical trials for acne, atopic dermatitis (AD), and psoriasis. We performed a comprehensive review of clinical trials for these common dermatologic diseases that were published between January 2014 and July 2019. Race and ethnicity reporting among all trials, and the racial and ethnic distribution of US participants were compared by skin disease, intervention type, and trial phase. In total, 103 articles representing 119 unique trials were evaluated. Race and ethnicity were reported in only 22.7% of trials. The proportion of White participants (77.5%) was higher than that of the US population (72.5%, p < 0.01); a finding largely driven by psoriasis trials (84.7% White). The proportions of non-White and Hispanic individuals in non-topical (21.0% and 16.3%, respectively) and phase III (20.5% and 18.7%, respectively) trials were lower than those in topical (23.5% and 23.3%, respectively; p < 0.01) and phase I/II trials (25.6% and 22.3%, respectively; p < 0.01). Race and ethnicity remain underreported in dermatologic clinical trials, and US trial participant diversity differs by skin disease, intervention type, and trial phase.

Evaluation of subclinical chronic sun damage in the skin via the detection of long-lasting ultraweak photon emission

BACKGROUND

It is well known that solar radiation accelerates skin photoaging. To evaluate subclinical photodamage in the skin especially from the early phase of ultraviolet (UV)-induced damage, we have focused on ultraweak photon emission (UPE), also called biophotons. Our previous study reported that the amount of long-lasting UPE induced by UV, predominantly from lipid peroxidation, is a valuable indicator to assess cutaneous photodamage even at a suberythemal dose, although it was only applied to evaluate acute UV damage. The aim of this study was to further investigate whether long-lasting UPE could also be a useful marker to assess subclinical chronic sun damage in the course of skin photoaging.

MATERIALS AND METHODS

Forty-three Japanese females in their 20s were recruited and were divided into two groups according to their history of sun exposure based on a questionnaire (high- and low-sun-exposure groups). Several skin properties on the cheek and outer forearm were measured in addition to UV-induced UPE.

RESULTS

Among the skin properties measured, water content, average skin roughness, and the lateral packing of lipids in the stratum corneum were significantly deteriorated in the high-sun-exposure group as were changes in some skin photoaging scores such as pigmented spots and wrinkles. In addition, those skin properties were correlated with the UPE signals, suggesting the possible impact of oxidative stress on chronic skin damage.

CONCLUSION

Subtle oxidative stress detected by long-lasting UPE may contribute to subclinical cutaneous damage at the beginning phase of chronic sun exposure, which potentially enhances skin photoaging over a lifetime.

Solar Ultraviolet Radiation Risk Estimates-A Comparison of Different Action Spectra and Detector Responsivities

Studies assessing the dose–response relationship for human skin cancer induction by solar ultraviolet radiation (UVR) apply a range of methods to quantify relevant UVR doses, but information about the comparability of these datasets is scarce. We compared biologically weighted effectivities applying the most relevant UVR action spectra in order to test the ability of certain UVR detectors to mimic these biological effects at different times during the day and year. Our calculations were based on solar spectra measured at Dortmund, Germany (51.5° N) and at Townsville, Australia (19.3° S), or computed for latitudes 20° S and 50° N. Convolutions with the CIE action spectra for erythema and non-melanoma skin cancer (NMSC) and with ICNIRP’s weighting function showed comparable solar zenith angle (SZA) dependences with little influence of season or latitude. A different SZA dependence was found with Setlow’s action spectrum for melanoma induction. Calculations for a number of UVR detector responsivities gave widely discrepant absolute irradiances and doses, which were nevertheless related to those calculated with both CIE spectra by correction factors largely independent of the SZA. Commonly used detectors can thus provide quite accurate estimates of NMSC induction by solar UVR, whereas they may be inadequate to mimic melanoma induction.

Vitamin D Levels in Patients with Colorectal Cancer Before and After Treatment Initiation

PURPOSE

We aimed to described 25-hydroxyvitamin D [25(OH)D] levels in newly diagnosed colorectal cancer (CRC) patients and to re-evaluate levels after chemotherapy.

METHODS

Permanent residents of the San Francisco Bay Area with a new CRC diagnosis of any stage were recruited prior to any non-surgical therapy. Serum 25(OH)D levels were measured at time of diagnosis and 6-month follow-up. Supplement use was not restricted. The primary endpoint was the frequency of vitamin D deficiency in patients with newly diagnosed CRC of all stages. The Kruskal-Wallis and Spearman correlation tests were used to evaluate associations of patient characteristics with 25(OH)D levels.

RESULTS

Median 25(OH)D level at baseline was 27.0 ng/mL (range 7.2, 59.0); 65% of patients had insufficient levels (25(OH)D < 30 ng/mL) (n = 94). Race, disease stage, multivitamin use, vitamin D supplementation, and county of residence were associated with baseline 25(OH)D levels (P < 0.05). The median change in 25(OH)D from baseline to 6 months was - 0.7 ng/mL [- 19.4, 51.7] for patients treated with chemotherapy (n = 58) and 1.6 ng/mL [- 6.4, 33.2] for patients who did not receive chemotherapy (n = 19) (P = 0.26). For patients who received vitamin D supplementation during chemotherapy, the median 25(OH)D change was 8.3 ng/mL [- 7.6, 51.7] versus - 1.6 [- 19.4, 24.3] for chemotherapy patients who did not take vitamin D supplements (P = 0.02).

CONCLUSION

Among patients with a new diagnosis of CRC, most patients were found to have 25(OH)D levels consistent with either deficiency or insufficiency. In the subset of patients who received chemotherapy and took a vitamin D supplement, serum 25(OH)D levels increased, suggesting that vitamin D repletion is a feasible intervention during chemotherapy.

Novel Gene Expression Profile of Women with Intrinsic Skin Youthfulness by Whole Transcriptome Sequencing

While much is known about genes that promote aging, little is known about genes that protect against or prevent aging, particularly in human skin. The main objective of this study was to perform an unbiased, whole transcriptome search for genes that associate with intrinsic skin youthfulness. To accomplish this, healthy women (n = 122) of European descent, ages 18–89 years with Fitzpatrick skin type I/II were examined for facial skin aging parameters and clinical covariates, including smoking and ultraviolet exposure. Skin youthfulness was defined as the top 10% of individuals whose assessed skin aging features were most discrepant with their chronological ages. Skin biopsies from sun-protected inner arm were subjected to 3’-end sequencing for expression quantification, with results verified by quantitative reverse transcriptase-polymerase chain reaction. Unbiased clustering revealed gene expression signatures characteristic of older women with skin youthfulness (n = 12) compared to older women without skin youthfulness (n = 33), after accounting for gene expression changes associated with chronological age alone. Gene set analysis was performed using Genomica open-access software. This study identified a novel set of candidate skin youthfulness genes demonstrating differences between SY and non-SY group, including pleckstrin homology like domain family A member 1 (PHLDA1) (p = 2.4x10^-5), a follicle stem cell marker, and hyaluronan synthase 2-anti-sense 1 (HAS2-AS1) (p = 0.00105), a non-coding RNA that is part of the hyaluronan synthesis pathway. We show that immunologic gene sets are the most significantly altered in skin youthfulness (with the most significant gene set p = 2.4x10^-5), suggesting the immune system plays an important role in skin youthfulness, a finding that has not previously been recognized. These results are a valuable resource from which multiple future studies may be undertaken to better understand the mechanisms that promote skin youthfulness in humans.