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Yao S, Chen X, Zhou Y, Xu L, Zhang Q, Bao S, Feng H, Ge W. The association between altitude and serum folate levels in Tibetan adults on the Tibetan plateau. Sci Rep 2022; 12:17886. [PMID: 36284137 PMCID: PMC9596477 DOI: 10.1038/s41598-022-22968-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/21/2022] [Indexed: 01/20/2023] Open
Abstract
This study investigated the relationship between residence altitude and serum folate levels in healthy Tibetans living on the Tibetan Plateau. Participants were selected from those who underwent physical examinations at our health center between November 2019 and February 2020. Demographic characteristics and medical histories were collected, and fasting blood was tested for serum folate and other hematological indicators. The relationship between altitude and serum folate levels was analyzed using a multivariable linear regression model. Serum folate levels were associated with altitude (β = - 0.44; 95% confidence interval [CI] - 0.71; - 0.16), hemoglobin (β = - 0.01; 95% CI - 0.03; - 0.00), red blood cells (β = - 0.72; 95% CI - 1.18; - 0.27), hematocrit (β = - 0.07; 95% CI - 0.12; - 0.02), high-density lipoprotein cholesterol (β = 2.67; 95% CI 1.35; 3.98), and sex (β = 0.68; 95% CI 0.12; 1.23). Multivariate linear regression analysis revealed that altitude was negatively associated with serum folate levels. After adjusting for confounding factors, serum folate levels decreased by 0.33 ng/mL per each 500-m increase in altitude (β = - 0.33; 95% CI - 0.6; - 0.05; P = 0.022). Altitude was negatively associated with serum folate levels in Tibetan adults. The relationship between altitude and folate levels should be further explored in populations of different races and disease states. Further large-scale prospective studies should illustrate the causality of this relationship.
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Affiliation(s)
- Shaoli Yao
- Department of Neurology, Hospital of Chengdu Office of People's Government of Tibet Autonomous Region, Chengdu, Sichuan, China.
| | - Xiwen Chen
- Department of Neurology, The Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, Chengdu, Sichuan, China
| | - Yao Zhou
- Department of Neurology, Hospital of Chengdu Office of People's Government of Tibet Autonomous Region, Chengdu, Sichuan, China
| | - Li Xu
- Department of Neurology, Hospital of Chengdu Office of People's Government of Tibet Autonomous Region, Chengdu, Sichuan, China
| | - Qi Zhang
- Department of Neurology, Hospital of Chengdu Office of People's Government of Tibet Autonomous Region, Chengdu, Sichuan, China
| | - Shimin Bao
- Department of Neurology, Hospital of Chengdu Office of People's Government of Tibet Autonomous Region, Chengdu, Sichuan, China
| | - Huiru Feng
- Department of Neurology, Hospital of Chengdu Office of People's Government of Tibet Autonomous Region, Chengdu, Sichuan, China
| | - Weihong Ge
- Department of Neurology, Hospital of Chengdu Office of People's Government of Tibet Autonomous Region, Chengdu, Sichuan, China
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2
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Tang JS, Cait A, White RM, Arabshahi HJ, O’Sullivan D, Gasser O. MR1-dependence of unmetabolized folic acid side-effects. Front Immunol 2022; 13:946713. [PMID: 36016938 PMCID: PMC9395688 DOI: 10.3389/fimmu.2022.946713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/21/2022] [Indexed: 11/28/2022] Open
Abstract
The fortification of flour with folic acid for the prevention of neural tube defects (NTD) is currently mandated in over eighty countries worldwide, hence compelling its consumption by the greater part of the world’s population. Notwithstanding its beneficial impact on rates of NTD, pervasive folic acid supplementation has invariably led to additive daily intakes reaching well beyond their original target, resulting in the circulation of unmetabolized folic acid. Associated idiopathic side-effects ranging from allergies to cancer have been suggested, albeit inconclusively. Herein, we hypothesize that their inconsistent detection and elusive etiology are linked to the in vivo generation of the immunosuppressive folic acid metabolite 6-formylpterin, which interferes with the still emerging and varied functions of Major Histocompatibility Complex-related molecule 1 (MR1)-restricted T cells. Accordingly, we predict that fortification-related adverse health outcomes can be eliminated by substituting folic acid with the bioequivalent folate vitamer 5-methyltetrahydrofolate, which does not break down into 6-formylpterin.
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Affiliation(s)
- Jeffry S. Tang
- Malaghan Institute of Medical Research, Wellington, New Zealand
- High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - Alissa Cait
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | - Reuben M. White
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | | | - David O’Sullivan
- Malaghan Institute of Medical Research, Wellington, New Zealand
- High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - Olivier Gasser
- Malaghan Institute of Medical Research, Wellington, New Zealand
- High-Value Nutrition National Science Challenge, Auckland, New Zealand
- *Correspondence: Olivier Gasser,
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3
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Naidoo K, Woods K, Pellefigues C, Cait A, O'Sullivan D, Gell K, Marshall AJ, Anderson RJ, Li Y, Schmidt A, Prasit K, Mayer JU, Gestin A, Hermans IF, Painter G, Jacobsen EA, Gasser O. 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. Allergy 2021; 76:3155-3170. [PMID: 34185885 DOI: 10.1111/all.14994] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 05/09/2021] [Accepted: 05/24/2021] [Indexed: 12/16/2022]
Abstract
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.
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Affiliation(s)
- Karmella Naidoo
- Malaghan Institute of Medical Research Wellington New Zealand
| | - Katherine Woods
- Malaghan Institute of Medical Research Wellington New Zealand
| | | | - Alissa Cait
- Malaghan Institute of Medical Research Wellington New Zealand
| | - David O'Sullivan
- Malaghan Institute of Medical Research Wellington New Zealand
- High‐Value Nutrition National Science Challenge Auckland New Zealand
| | - Katie Gell
- Malaghan Institute of Medical Research Wellington New Zealand
| | - Andrew J. Marshall
- Ferrier Research Institute Victoria University of Wellington Lower Hutt New Zealand
| | - Regan J. Anderson
- Ferrier Research Institute Victoria University of Wellington Lower Hutt New Zealand
| | - Yanyan Li
- Malaghan Institute of Medical Research Wellington New Zealand
- High‐Value Nutrition National Science Challenge Auckland New Zealand
| | - Alfonso Schmidt
- Malaghan Institute of Medical Research Wellington New Zealand
| | - Kef Prasit
- Malaghan Institute of Medical Research Wellington New Zealand
| | | | - Aurelie Gestin
- Malaghan Institute of Medical Research Wellington New Zealand
| | - Ian F. Hermans
- Malaghan Institute of Medical Research Wellington New Zealand
| | - Gavin Painter
- Ferrier Research Institute Victoria University of Wellington Lower Hutt New Zealand
| | - Elizabeth A. Jacobsen
- Division of Allergy, Asthma and Clinical Immunology Mayo Clinic Arizona Scottsdale AZ USA
| | - Olivier Gasser
- Malaghan Institute of Medical Research Wellington New Zealand
- High‐Value Nutrition National Science Challenge Auckland New Zealand
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4
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Environmental UVR Levels and Skin Pigmentation Gene Variants Associated with Folate and Homocysteine Levels in an Elderly Cohort. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17051545. [PMID: 32121219 PMCID: PMC7084217 DOI: 10.3390/ijerph17051545] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/26/2020] [Accepted: 02/26/2020] [Indexed: 12/15/2022]
Abstract
Ultraviolet radiation (UVR) is a ubiquitous exposure which may contribute to decreased folate levels. Skin pigmentation mediates the biological effect of UVR exposure, but its relationship to folate levels is unexamined. Interactions may exist between UVR and pigmentation genes in determining folate status, which may, in turn, impact homocysteine levels, a potential risk factor for multiple chronic diseases. Therefore, independent and interactive influences of environmental UVR and genetic variants related to skin pigmentation (MC1R-rs1805007, IRF4-rs12203592 and HERC2-rs12913832) on folate (red blood cell (RBC) and serum) and homocysteine levels were examined in an elderly Australian cohort (n = 599). Genotypes were assessed by RT/RFLP-PCR, and UVR exposures were assessed as the accumulated erythemal dose rate accumulated over 4 months (4M-EDR). Multivariate analysis found significant negative associations between 4M-EDR and RBC folate (p < 0.001, β = −0.19), serum folate (p = 0.045, β = −0.08) and homocysteine levels (p < 0.001, β = −0.28). Significant associations between MC1R-rs1805007 and serum folate levels (p = 0.020), and IRF4-rs12203592 and homocysteine levels (p = 0.026) occurred but did not remain significant following corrections with confounders. No interactions between 4M-EDR and pigmentation variants in predicting folate/homocysteine levels were found. UVR levels and skin pigmentation-related variants are potential determinants of folate and homocysteine status, although, associations are mixed and complex, with further studies warranted.
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Deobald D, Hanna R, Shahryari S, Layer G, Adrian L. Identification and characterization of a bacterial core methionine synthase. Sci Rep 2020; 10:2100. [PMID: 32034217 PMCID: PMC7005905 DOI: 10.1038/s41598-020-58873-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/20/2020] [Indexed: 11/18/2022] Open
Abstract
Methionine synthases are essential enzymes for amino acid and methyl group metabolism in all domains of life. Here, we describe a putatively anciently derived type of methionine synthase yet unknown in bacteria, here referred to as core-MetE. The enzyme appears to represent a minimal MetE form and transfers methyl groups from methylcobalamin instead of methyl-tetrahydrofolate to homocysteine. Accordingly, it does not possess the tetrahydrofolate binding domain described for canonical bacterial MetE proteins. In Dehalococcoides mccartyi strain CBDB1, an obligate anaerobic, mesophilic, slowly growing organohalide-respiring bacterium, it is encoded by the locus cbdbA481. In line with the observation to not accept methyl groups from methyl-tetrahydrofolate, all known genomes of bacteria of the class Dehalococcoidia lack metF encoding for methylene-tetrahydrofolate reductase synthesizing methyl-tetrahydrofolate, but all contain a core-metE gene. We heterologously expressed core-MetECBDB in E. coli and purified the 38 kDa protein. Core-MetECBDB exhibited Michaelis-Menten kinetics with respect to methylcob(III)alamin (KM ≈ 240 µM) and L-homocysteine (KM ≈ 50 µM). Only methylcob(III)alamin was found to be active as methyl donor with a kcat ≈ 60 s-1. Core-MetECBDB did not functionally complement metE-deficient E. coli strain DH5α (ΔmetE::kan) suggesting that core-MetECBDB and the canonical MetE enzyme from E. coli have different enzymatic specificities also in vivo. Core-MetE appears to be similar to a MetE-ancestor evolved before LUCA (last universal common ancestor) using methylated cobalamins as methyl donor whereas the canonical MetE consists of a tandem repeat and might have evolved by duplication of the core-MetE and diversification of the N-terminal part to a tetrahydrofolate-binding domain.
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Affiliation(s)
- Darja Deobald
- Leipzig University, Institute of Biochemistry, Brüderstraße 34, 04103, Leipzig, Germany
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Permoserstraße 15, 04318, Leipzig, Germany
| | - Rafael Hanna
- Leipzig University, Institute of Biochemistry, Brüderstraße 34, 04103, Leipzig, Germany
- Freiburg University, Institute of Pharmaceutical Sciences, Stefan-Meier-Straße 19, 79104, Freiburg im Breisgau, Germany
| | - Shahab Shahryari
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Permoserstraße 15, 04318, Leipzig, Germany
| | - Gunhild Layer
- Leipzig University, Institute of Biochemistry, Brüderstraße 34, 04103, Leipzig, Germany
- Freiburg University, Institute of Pharmaceutical Sciences, Stefan-Meier-Straße 19, 79104, Freiburg im Breisgau, Germany
| | - Lorenz Adrian
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Permoserstraße 15, 04318, Leipzig, Germany.
- Technische Universität Berlin, Chair of Geobiotechnology, Ackerstraße 76, 13355, Berlin, Germany.
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6
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Kamalian P, Khorasani SN, Abdolmaleki A, Karevan M, Khalili S, Shirani M, Neisiany RE. Toward the development of polyethylene photocatalytic degradation. JOURNAL OF POLYMER ENGINEERING 2020. [DOI: 10.1515/polyeng-2019-0230] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AbstractIn this research, the photocatalytic degradation performance in a commercial low-density polyethylene (LDPE) film was investigated in the presence of zinc oxide (ZnO) nanoparticles grafted with two amounts of polyacrylamide. Fourier-transform infrared spectroscopy (FTIR) besides thermogravimetric analysis (TGA) test results reinforced the successful grafting of polyacrylamide to the extent of 10 and 39 wt.% on the ZnO nanoparticles. The photocatalytic degradation of the films under ultraviolet (UV) radiation was evaluated by characterizing the mechanical properties, weight loss, and morphology. The UV absorption and emission for ZnO nanoparticles were increased after grafting with 10% polyacrylamide. The tensile strength of the nanocomposite films increased with the incorporation of nanoparticles. The presence of ZnO nanoparticles in LDPE films increased the rate of degradation after 200 h of irradiation. The polyacrylamide grafting improved the dispersion of ZnO particles in LDPE matrix, whereas the increase of grafting extent from 10 to 39 wt.% reduced the photocatalytic performance of ZnO nanoparticles.
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Affiliation(s)
- Parisa Kamalian
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Saied Nouri Khorasani
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Amir Abdolmaleki
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Mehdi Karevan
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Shahla Khalili
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Mohammad Shirani
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Rasoul Esmaeely Neisiany
- Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran
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7
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Weber B, Marculescu R, Radakovic S, Tanew A. Serum levels of folate, 25-hydroxyvitamin D3 and cobalamin during UVB phototherapy: findings in a large prospective trial. J Eur Acad Dermatol Venereol 2019; 34:385-391. [PMID: 31494977 PMCID: PMC7027503 DOI: 10.1111/jdv.15941] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 08/21/2019] [Indexed: 11/29/2022]
Abstract
Background Narrowband UVB phototherapy (NB‐UVB) is a mainstay in the treatment of numerous inflammatory dermatoses. Whereas, a wealth of studies has shown that NB‐UVB treatment increases 25‐hydroxyvitamin D3 (25(OH)D) levels, only sparse and controversial data exist on its effect on serum folate and cobalamin. Objectives To determine whether exposure to NB‐UVB alters serum folate or cobalamin levels. Methods A single‐centre, prospective, open observational study on 101 patients subjected to NB‐UVB phototherapy between late fall and early spring. Serum folate, 25(OH)D and cobalamin levels were measured after 0, 12, 24 and 36 NB‐UVB exposures. Results After 12 NB‐UVB exposures a significant decrease of mean serum folate (−1.0 nmol/L; P = 0.03) and cobalamin (−14.5 pmol/L, P = 0.03) levels was observed whereas serum levels of 25(OH)D showed a significant increase (35.4 nmol/L, P < 0.0001). Conclusions A standard course of NB‐UVB induces a small but significant decrease of serum folate and cobalamin levels.
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Affiliation(s)
- B Weber
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - R Marculescu
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - S Radakovic
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - A Tanew
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
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8
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Wolf ST, Kenney WL. The vitamin D-folate hypothesis in human vascular health. Am J Physiol Regul Integr Comp Physiol 2019; 317:R491-R501. [PMID: 31314544 DOI: 10.1152/ajpregu.00136.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The vitamin D-folate hypothesis has been proposed as an explanation for the evolution of human skin pigmentation. According to this hypothesis, a darkened skin pigment was adapted by early human populations living in equatorial Africa to protect against photodegradation of bioavailable folate by ultraviolet radiation (UVR). As humans moved away from the equator to more northern latitudes and occupied regions of lower UVR exposure and greater seasonal variation, however, depigmentation occurred to allow for adequate biosynthesis of vitamin D. Vitamin D and folate are both recognized for their evolutionary importance in healthy pregnancy and early childhood development. More recently, evidence has emerged demonstrating the importance of both vitamin D and folate in vascular health via their effects in reducing oxidative stress and improving nitric oxide (NO) bioavailability. Thus, populations with darkened skin pigmentation may be at elevated risk of vascular dysfunction and cardiovascular disease in low UVR environments due to hypovitaminosis D; particularly important as darkly-pigmented African-Americans represent an at-risk population for cardiovascular disease. Conversely, lightly pigmented populations in high UVR environments may be at risk of deleterious vascular effects of UVR-induced folate degradation. The focus of this review is to explore the currently available literature regarding the potential role of UVR in vascular health via its differential effects on vitamin D and folate metabolism, as well as the interaction between skin pigmentation, genetics, and environment in modulating the vascular influence of UVR exposure.
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Affiliation(s)
- S Tony Wolf
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
| | - W Larry Kenney
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania.,Graduate Program in Physiology, The Pennsylvania State University, University Park, Pennsylvania
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9
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Wolf ST, Berry CW, Stanhewicz AE, Kenney LE, Ferguson SB, Kenney WL. Sunscreen or simulated sweat minimizes the impact of acute ultraviolet radiation on cutaneous microvascular function in healthy humans. Exp Physiol 2019; 104:1136-1146. [PMID: 31004462 DOI: 10.1113/ep087688] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/18/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Are ultraviolet radiation (UVR)-induced increases in skin blood flow independent of skin erythema? Does broad-spectrum UVR exposure attenuate NO-mediated cutaneous vasodilatation, and does sunscreen or sweat modulate this response? What are the main findings and their importance? Erythema and vascular responses to UVR are temporally distinct, and sunscreen prevents both responses. Exposure to UVR attenuates NO-mediated vasodilatation in the cutaneous microvasculature; sunscreen or simulated sweat on the skin attenuates this response. Sun over-exposure may elicit deleterious effects on human skin that are separate from sunburn, and sunscreen or sweat on the skin may provide protection. ABSTRACT Exposure to ultraviolet radiation (UVR) may result in cutaneous vascular dysfunction independent of erythema (skin reddening). Two studies were designed to differentiate changes in erythema from skin vasodilatation throughout the 8 h after acute broad-spectrum UVR exposure with (+SS) or without SPF-50 sunscreen (study 1) and to examine NO-mediated cutaneous vasodilatation after acute broad-spectrum UVR exposure with or without +SS or simulated sweat (+SW) on the skin (study 2). In both studies, laser-Doppler flowmetry was used to measure red cell flux, and cutaneous vascular conductance (CVC) was calculated (CVC = flux/mean arterial pressure). In study 1, in 14 healthy adults (24 ± 4 years old; seven men and seven women), the skin erythema index and CVC were measured over two forearm sites (UVR only and UVR+SS) before, immediately after and every 2 h for 8 h post-exposure (750 mJ cm-2 ). The erythema index began to increase immediately post-UVR (P < 0.05 at 4, 6 and 8 h), but CVC did not increase above baseline for the first 4-6 h (P ≤ 0.01 at 6 and 8 h); +SS prevented both responses. In study 2, in 13 healthy adults (24 ± 4 years old; six men and seven women), three intradermal microdialysis fibres were placed in the ventral skin of the forearm [randomly assigned to UVR (450 mJ cm-2 ), UVR+SS or UVR+SW], and one fibre (non-exposed control; CON) was placed in the contralateral forearm. After UVR, a standardized local heating (42°C) protocol quantified the percentage of NO-mediated vasodilatation (%NO). The UVR attenuated %NO compared with CON (P = 0.01). The diminished %NO was prevented by +SS (P < 0.01) and +SW (P < 0.01). Acute broad-spectrum UVR attenuates NO-dependent dilatation in the cutaneous microvasculature, independent of erythema. Sunscreen protects against both inflammatory and heating-induced endothelial dysfunction, and sweat might prevent UVR-induced reductions in NO-dependent dilatation.
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Affiliation(s)
- S Tony Wolf
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
| | - Craig W Berry
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
| | - Anna E Stanhewicz
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
| | - Lauren E Kenney
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA.,Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Sara B Ferguson
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA.,Department of Dermatology, The Penn State Hershey Medical Group, State College, PA, USA
| | - W Larry Kenney
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA.,Graduate Program in Physiology, The Pennsylvania State University, University Park, PA, USA
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10
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Valencia-Vera E, Aguilera J, Cobos A, Bernabó JL, Pérez-Valero V, Herrera-Ceballos E. Association between seasonal serum folate levels and ultraviolet radiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 190:66-71. [DOI: 10.1016/j.jphotobiol.2018.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 12/11/2022]
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11
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Grafted ZnO nanoparticles used for development in photocatalytic degradation performance of polyethylene. Polym Bull (Berl) 2018. [DOI: 10.1007/s00289-018-2564-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Wolf ST, Stanhewicz AE, Jablonski NG, Kenney WL. Acute ultraviolet radiation exposure attenuates nitric oxide-mediated vasodilation in the cutaneous microvasculature of healthy humans. J Appl Physiol (1985) 2018; 125:1232-1237. [PMID: 30138076 DOI: 10.1152/japplphysiol.00501.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
5-methyltetrahydrofolate (5-MTHF) is important for nitric oxide (NO)-mediated cutaneous microvascular vasodilation. Ultraviolet B (UVB) radiation may deplete 5-MTHF, either directly or via production of reactive oxygen species (ROS), decreasing NO-mediated vasodilation. We hypothesized that 1) acute UVB exposure would attenuate NO-dependent cutaneous vasodilation, 2) local perfusion of 5-MTHF or ascorbate (ASC; anti-oxidant) would augment NO-dependent vasodilation after UVB, and 3) darker skin pigmentation would be UVB-protective. Three intradermal microdialysis fibers placed in each forearm of 21 healthy young adults (23±1 yr; 8M/13F) locally delivered lactated Ringer's (control), 5mM 5-MTHF, or 10mM ASC. One arm was UVB-exposed (300mJ/cm2), the other served as non-exposed control (CON). Following UVB exposure, a standardized local heating (42˚C) protocol induced cutaneous vasodilation. After attaining a plateau blood flow, 15mM NG-nitro-L-arginine methyl ester (L-NAME; nitric oxide synthase inhibiter) was infused at all sites to quantify the NO contribution. Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) and cutaneous vascular conductance (CVC=LDF/MAP) was expressed as a percentage of maximum (%CVCmax; 28mM sodium nitroprusside+43°C). UVB attenuated NO-mediated vasodilation compared to CON (23.1±3.6 vs 33.9±3.4 %; p=0.001). Delivery of 5-MTHF or ASC improved NO-mediated vasodilation versus lactated Ringer's in the UVB-exposed arm (MTHF: 30.1±4.8 vs 23.1±3.8 %; p=0.03; ASC: 30.9±4.3 vs 23.1±3.8 %; p=0.02). Neither treatment affected the response in the non-exposed arm (p≥0.09). Skin pigmentation (M-index) was not predictive of the UVB response (p≥0.34). These data suggest that acute UVB exposure attenuates NO-mediated vasodilation via direct and/or ROS-induced reductions in 5-MTHF, independent of skin pigmentation.
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Affiliation(s)
- S Tony Wolf
- Kinesiology, The Pennsylvania State University, United States
| | - Anna E Stanhewicz
- Department of Kinesiology, The Pennsylvania State University, United States
| | | | - W Larry Kenney
- Department of Kinesiology, The Pennsylvania State University, United States
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13
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Assay and Analysis of Dimethylsulfoniopropionate Demethylase. Methods Enzymol 2018. [PMID: 29909830 DOI: 10.1016/bs.mie.2018.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Dimethylsulfoniopropionate (DMSP) demethylase is a tetrahydrofolate-dependent enzyme that initiates the DMSP demethylation pathway in marine bacteria. This enzyme is important for understanding of organic sulfur flux from the oceans because it directs the sulfur from DMSP away from dimethylsulfide. This enzyme has been purified and characterized from two marine bacteria from different ecological niches. Both enzymes were confirmed to catalyze the tetrahydrofolate-dependent demethylation of DMSP and possessed similar properties. In this chapter a description of the steps for performing enzyme assays and measuring enzyme activity is provided.
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Zhang M, Goyert G, Lim HW. Folate and phototherapy: What should we inform our patients? J Am Acad Dermatol 2017; 77:958-964. [DOI: 10.1016/j.jaad.2016.10.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/23/2016] [Accepted: 10/07/2016] [Indexed: 12/19/2022]
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Jablonski NG, Chaplin G. The colours of humanity: the evolution of pigmentation in the human lineage. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160349. [PMID: 28533464 PMCID: PMC5444068 DOI: 10.1098/rstb.2016.0349] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2016] [Indexed: 12/16/2022] Open
Abstract
Humans are a colourful species of primate, with human skin, hair and eye coloration having been influenced by a great variety of evolutionary forces throughout prehistory. Functionally naked skin has been the physical interface between the physical environment and the human body for most of the history of the genus Homo, and hence skin coloration has been under intense natural selection. From an original condition of protective, dark, eumelanin-enriched coloration in early tropical-dwelling Homo and Homo sapiens, loss of melanin pigmentation occurred under natural selection as Homo sapiens dispersed into non-tropical latitudes of Africa and Eurasia. Genes responsible for skin, hair and eye coloration appear to have been affected significantly by population bottlenecks in the course of Homo sapiens dispersals. Because specific skin colour phenotypes can be created by different combinations of skin colour-associated genetic markers, loss of genetic variability due to genetic drift appears to have had negligible effects on the highly redundant genetic 'palette' for the skin colour. This does not appear to have been the case for hair and eye coloration, however, and these traits appear to have been more strongly influenced by genetic drift and, possibly, sexual selection.This article is part of the themed issue 'Animal coloration: production, perception, function and application'.
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Affiliation(s)
- Nina G Jablonski
- Department of Anthropology, The Pennsylvania State University, 409 Carpenter Building, University Park, PA 16802, USA
| | - George Chaplin
- Department of Anthropology, The Pennsylvania State University, 409 Carpenter Building, University Park, PA 16802, USA
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Gautam P, Chaurasia A, Bhattacharya A, Grover R, Mukerji M, Natarajan VT. Population diversity and adaptive evolution in keratinization genes: impact of environment in shaping skin phenotypes. Mol Biol Evol 2014; 32:555-73. [PMID: 25534032 DOI: 10.1093/molbev/msu342] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Several studies have demonstrated the role of climatic factors in shaping skin phenotypes, particularly pigmentation. Keratinization is another well-designed feature of human skin, which is involved in modulating transepidermal water loss (TEWL). Although this physiological process is closely linked to climate, presently it is not clear whether genetic diversity is observed in keratinization and whether this process also responds to the environmental pressure. To address this, we adopted a multipronged approach, which involved analysis of 1) copy number variations in diverse Indian and HapMap populations from varied geographical regions; 2) genetic association with geoclimatic parameters in 61 populations of dbCLINE database in a set of 549 genes from four processes namely keratinization, pigmentation, epidermal differentiation, and housekeeping functions; 3) sequence divergence in 4,316 orthologous promoters and corresponding exonic regions of human and chimpanzee with macaque as outgroup, and 4) protein sequence divergence (Ka/Ks) across nine vertebrate classes, which differ in their extent of TEWL. Our analyses demonstrate that keratinization and epidermal differentiation genes are under accelerated evolution in the human lineage, relative to pigmentation and housekeeping genes. We show that this entire pathway may have been driven by environmental selection pressure through concordant functional polymorphisms across several genes involved in skin keratinization. Remarkably, this underappreciated function of skin may be a crucial determinant of adaptation to diverse environmental pressures across world populations.
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Affiliation(s)
- Pramod Gautam
- Genomics and Molecular Medicine, Council for Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India
| | - Amit Chaurasia
- Genomics and Molecular Medicine, Council for Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India
| | - Aniket Bhattacharya
- Genomics and Molecular Medicine, Council for Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India Academy of Scientific and Innovative Research, Delhi, India
| | - Ritika Grover
- Academy of Scientific and Innovative Research, Delhi, India Systems Biology Group, Council for Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India
| | | | - Mitali Mukerji
- Genomics and Molecular Medicine, Council for Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India Academy of Scientific and Innovative Research, Delhi, India
| | - Vivek T Natarajan
- Academy of Scientific and Innovative Research, Delhi, India Systems Biology Group, Council for Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India
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UVB exposure of farm animals: study on a food-based strategy to bridge the gap between current vitamin D intakes and dietary targets. PLoS One 2013; 8:e69418. [PMID: 23894475 PMCID: PMC3722170 DOI: 10.1371/journal.pone.0069418] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 06/10/2013] [Indexed: 01/04/2023] Open
Abstract
Vitamin D deficiency is a global health problem. This study aimed to investigate the efficacy of ultraviolet (UV) B radiation for improving vitamin D3 content of eggs and meat. In a two-factorial design hens that received diets with 0 (-D3) or 3,000 IU (+D3) vitamin D3/kg were non-exposed (-UVB) or exposed to UVB radiation (+UVB) for 3 h daily over 4 weeks. Data show that UVB radiation was very effective in raising the vitamin D3 content of egg yolk and meat. Egg yolk from +UVB/−D3 hens had a higher vitamin D3 content (17.5±7.2 µg/100 g dry matter (DM)) than those from the –UVB/+D3 group (5.2±2.4 µg/100 g DM, p<0.01). Vitamin D3 content in egg yolk of vitamin D3-supplemented hens could be further increased by UVB radiation (32.4±10.9 µg/100 g DM). The content of 25-hydroxyvitamin D3 (25(OH)D3) in the egg yolk also increased in response to UVB, although less pronounced than vitamin D3. Meat revealed about 4-fold higher vitamin D3 contents in response to UVB than to dietary vitamin D3 (p<0.001). In conclusion, exposure of hens to UVB is an efficient approach to provide consumers with vitamin D3-enriched foods from animal sources.
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Delchier N, Reich M, Renard CM. Impact of cooking methods on folates, ascorbic acid and lutein in green beans (Phaseolus vulgaris) and spinach (Spinacea oleracea). Lebensm Wiss Technol 2012. [DOI: 10.1016/j.lwt.2012.06.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Moan J, Nielsen KP, Juzeniene A. Immediate pigment darkening: its evolutionary roles may include protection against folate photosensitization. FASEB J 2011; 26:971-5. [DOI: 10.1096/fj.11-195859] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Johan Moan
- Department of Radiation BiologyInstitute for Cancer ResearchNorwegian Radium HospitalOslo University HospitalMontebelloNorway
- Institute of PhysicsUniversity of OsloOsloNorway
| | | | - Asta Juzeniene
- Department of Radiation BiologyInstitute for Cancer ResearchNorwegian Radium HospitalOslo University HospitalMontebelloNorway
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Xue S, Ye X, Shi J, Jiang Y, Liu D, Chen J, Shi A, Kakuda Y. Degradation kinetics of folate (5-methyltetrahydrofolate) in navy beans under various processing conditions. Lebensm Wiss Technol 2011. [DOI: 10.1016/j.lwt.2010.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Colloquium paper: human skin pigmentation as an adaptation to UV radiation. Proc Natl Acad Sci U S A 2010; 107 Suppl 2:8962-8. [PMID: 20445093 DOI: 10.1073/pnas.0914628107] [Citation(s) in RCA: 409] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human skin pigmentation is the product of two clines produced by natural selection to adjust levels of constitutive pigmentation to levels of UV radiation (UVR). One cline was generated by high UVR near the equator and led to the evolution of dark, photoprotective, eumelanin-rich pigmentation. The other was produced by the requirement for UVB photons to sustain cutaneous photosynthesis of vitamin D(3) in low-UVB environments, and resulted in the evolution of depigmented skin. As hominins dispersed outside of the tropics, they experienced different intensities and seasonal mixtures of UVA and UVB. Extreme UVA throughout the year and two equinoctial peaks of UVB prevail within the tropics. Under these conditions, the primary selective pressure was to protect folate by maintaining dark pigmentation. Photolysis of folate and its main serum form of 5-methylhydrofolate is caused by UVR and by reactive oxygen species generated by UVA. Competition for folate between the needs for cell division, DNA repair, and melanogenesis is severe under stressful, high-UVR conditions and is exacerbated by dietary insufficiency. Outside of tropical latitudes, UVB levels are generally low and peak only once during the year. The populations exhibiting maximally depigmented skin are those inhabiting environments with the lowest annual and summer peak levels of UVB. Development of facultative pigmentation (tanning) was important to populations settling between roughly 23 degrees and 46 degrees , where levels of UVB varied strongly according to season. Depigmented and tannable skin evolved numerous times in hominin evolution via independent genetic pathways under positive selection.
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