Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 135
Filtrar
1.
Anticancer Res ; 40(2): 583-595, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32014899

RESUMO

BACKGROUND/AIM: Increasing evidence indicates a relevance of the vitamin D endocrine system for pathogenesis of malignant melanoma. We performed a systematic review and meta-analysis to update previous reports that investigated the association between vitamin D receptor (VDR) gene polymorphisms and melanoma risk. MATERIALS AND METHODS: A comprehensive literature search (PubMed, ISI Web of Science) identified a total of 14 studies that were eligible for inclusion in our meta-analysis. In the statistical analysis, the ORs and the 95% CIs were calculated for the dominant and recessive models for seven VDR gene polymorphisms, namely rs2228570 (FokI), rs731236 (TaqI), rs1544410 (BsmI), rs4516035 (A-1012G), rs11568820 (Cdx2), rs7975232 (ApaI) and rs739837 (BglI). Results were illustrated in Forest Plots. Publication bias was tested using Funnel Plots and the Egger's test. RESULTS: Our meta-analysis showed in the dominant model (Bb + BB vs. bb) a significant association of a 15% risk reduction in malignant melanoma incidence for carriers of the rarer allele B of rs1544410 (Bsml). Notably, the dominant model (Ff + ff vs. FF) of rs2228570 (FokI) demonstrates that carriers of the rarer allele f are 22% more likely to develop malignant melanoma. For rs7975232 (ApaI), there is a 20% higher risk of melanoma for carriers of the rarer a allele (Aa + aa vs. AA). The results of the meta-analysis revealed no significant association between melanoma risk and the other investigated VDR polymorphisms. CONCLUSION: The VDR variants FokI, ApaI and BsmI may influence the susceptibility to developing melanoma. These findings support the concept, that the vitamin D endocrine system is of importance for pathogenesis of malignant melanoma.

2.
Adv Exp Med Biol ; 1218: 1-7, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32060868

RESUMO

The attention of science first turned to the gene that later earned the name Notch over a century ago, when the American scientist John S. Dexter discovered in his laboratory at Olivet College the characteristic notched-wing phenotype (a nick or notch in the wingtip) in mutant fruit flies Drosophila melanogaster. At present, it is generally accepted that the Notch pathway governs tissue patterning and many key cell fate decisions and other core processes during embryonic development and in adult tissues. Not surprisingly, a broad variety of independent inherited diseases (including CADASIL, Alagille, Adams-Oliver, and Hajdu-Cheney syndromes) have now convincingly been linked to defective Notch signaling. In the second edition of the book entitled Notch Signaling in Embryology and Cancer, leading researchers provide a comprehensive, highly readable overview on molecular mechanisms of Notch signaling (Volume I), and notch's roles in embryology (Vol. II) and cancer (Vol. III). In these introductory pages of Vol. II, we give a short overview on its individual chapters, which are intended to provide both basic scientists and clinicians who seek today's clearest understanding of the broad role of Notch signaling in embryology with an authoritative day-to-day source.

3.
Adv Exp Med Biol ; 1218: 9-37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32060869

RESUMO

The evolutionary highly conserved Notch pathway, which first developed during evolution in metazoans and was first discovered in fruit flies (Drosophila melanogaster), governs many core processes including cell fate decisions during embryonic development. A huge mountain of scientific evidence convincingly demonstrates that Notch signaling represents one of the most important pathways that regulate embryogenesis from sponges, roundworms, Drosophila melanogaster, and mice to humans. In this review, we give a brief introduction on how Notch orchestrates the embryonic development of several selected tissues, summarizing some of the most relevant findings in the central nervous system, skin, kidneys, liver, pancreas, inner ear, eye, skeleton, heart, and vascular system.

4.
Adv Exp Med Biol ; 1218: 159-187, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32060876

RESUMO

The evolutionary highly conserved Notch pathway governs many cellular core processes including cell fate decisions. Although it is characterized by a simple molecular design, Notch signaling, which first developed in metazoans, represents one of the most important pathways that govern embryonic development. Consequently, a broad variety of independent inherited diseases linked to defective Notch signaling has now been identified, including Alagille, Adams-Oliver, and Hajdu-Cheney syndromes, CADASIL (cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy), early-onset arteriopathy with cavitating leukodystrophy, lateral meningocele syndrome, and infantile myofibromatosis. In this review, we give a brief overview on molecular pathology and clinical findings in congenital diseases linked to the Notch pathway. Moreover, we discuss future developments in basic science and clinical practice that may emerge from recent progress in our understanding of the role of Notch in health and disease.

5.
Anticancer Res ; 40(1): 501-509, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31892605

RESUMO

BACKGROUND: Intensive scientific debate is ongoing about whether moderate solarium use increases melanoma risk. The authors of some recent publications demand the debate be closed and propose "actions against solarium use for skin cancer prevention" because new studies have convincingly demonstrated causality. This minireview aims to investigate whether those demands are sufficiently supported by present scientific knowledge and comply with the principles of evidence-based medicine. MATERIALS AND METHODS: We performed a systematic literature search (through June 2019; PubMed, ISI Web of Science) to identify publications investigating how solarium use affects melanoma risk. RESULTS: We found no studies that demonstrate a causal relationship between moderate solarium use and melanoma risk. Results of cohort and case-control studies published to date, including recent investigations, do not prove causality, and randomized controlled trials providing unequivocal proof are still lacking. Moreover, the overall quality of observational studies is low as a result of severe limitations (including unobserved or unrecorded confounding), possibly leading to bias. We also disagree with recent claims that Hill's criteria for the epidemiological evidence of a causal relationship between a potential causal factor and an observed effect are fulfilled in regard to the conclusion that moderate solarium use per se would increase melanoma risk Conclusion: Current scientific knowledge does not demonstrate a causal relationship between moderate solarium use and melanoma risk. Therefore, the debate is not closed.


Assuntos
Melanoma/epidemiologia , Banho de Sol , Animais , Humanos , Fatores de Risco , Raios Ultravioleta
6.
Nutrients ; 11(11)2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31698703

RESUMO

During the last decade, our scientific knowledge of the pleiotropic biological effects of vitamin D metabolites and their relevance to human health has expanded widely. Beyond the well-known key role of vitamin D in calcium homeostasis and bone health, it has been shown that vitamin D deficiency is associated with a broad variety of independent diseases, including several types of cancer, and with increased overall mortality. Moreover, recent findings have demonstrated biological effects of the vitamin D endocrine system that are not mediated via activation of the classical nuclear vitamin D receptor (VDR) by binding with high affinity to its corresponding ligand, the biologically active vitamin D metabolite 1,25-dihydroxyvitamin D (1,25(OH)2D). In contrast, many of these new biological effects of vitamin D compounds, including regulation of the circadian clock and many metabolic functions, are mediated by other vitamin D metabolites, including 20-hydroxyvitamin D and 20,23-dihydroxyvitamin D, and involve their binding to the aryl hydrocarbon receptor (AhR) and retinoid-orphan receptor (ROR). In most populations, including the German population, UVB-induced cutaneous vitamin D production is the main source for fulfilling the human body's requirements of vitamin D. However, this causes a dilemma because solar or artificial UVR exposure is associated with skin cancer risk. In addition to UVB-induced vitamin D production in skin, in humans, there are two other possible sources of vitamin D: from diet and supplements. However, only a few natural foods contain substantial amounts of vitamin D, and in most populations, the dietary source of vitamin D cannot fulfill the body´s requirements. Because an increasing body of evidence has convincingly demonstrated that vitamin D deficiency is very common worldwide, it is the aim of this paper to (i) give an update of the vitamin D status in a population with a western diet, namely, the German population, and to (ii) develop strategies to optimize the vitamin D supply that consider both the advantages as well as the disadvantages/risks of different approaches, including increasing vitamin D status by dietary intake, by supplements, or by UVB-induced cutaneous synthesis of vitamin D.

7.
Cancer Res ; 79(23): 5986-5998, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31690667

RESUMO

1α,25-Dihydroxyvitamin D3 signals via the vitamin D receptor (VDR). Higher serum vitamin D is associated with thinner primary melanoma and better outcome, although a causal mechanism has not been established. As patients with melanoma commonly avoid sun exposure, and consequent vitamin D deficiency might worsen outcomes, we interrogated 703 primary melanoma transcriptomes to understand the role of vitamin D-VDR signaling and replicated the findings in The Cancer Genome Atlas metastases. VDR expression was independently protective for melanoma-related death in both primary and metastatic disease. High tumor VDR expression was associated with upregulation of pathways mediating antitumor immunity and corresponding with higher imputed immune cell scores and histologically detected tumor-infiltrating lymphocytes. High VDR-expressing tumors had downregulation of proliferative pathways, notably Wnt/ß-catenin signaling. Deleterious low VDR levels resulted from promoter methylation and gene deletion in metastases. Vitamin D deficiency (<25 nmol/L ∼ 10 ng/mL) shortened survival in primary melanoma in a VDR-dependent manner. In vitro functional validation studies showed that elevated vitamin D-VDR signaling inhibited Wnt/ß-catenin signaling genes. Murine melanoma cells overexpressing VDR produced fewer pulmonary metastases than controls in tail-vein metastasis assays. In summary, vitamin D-VDR signaling contributes to controlling pro-proliferative/immunosuppressive Wnt/ß-catenin signaling in melanoma and this is associated with less metastatic disease and stronger host immune responses. This is evidence of a causal relationship between vitamin D-VDR signaling and melanoma survival, which should be explored as a therapeutic target in primary resistance to checkpoint blockade. SIGNIFICANCE: VDR expression could potentially be used as a biomarker to stratify patients with melanoma that may respond better to immunotherapy.

9.
Artigo em Inglês | MEDLINE | ID: mdl-30065699

RESUMO

Vitamin D deficiency can lead to musculoskeletal diseases such as rickets and osteomalacia, but vitamin D supplementation may also prevent extraskeletal diseases such as respiratory tract infections, asthma exacerbations, pregnancy complications and premature deaths. Vitamin D has a unique metabolism as it is mainly obtained through synthesis in the skin under the influence of sunlight (i.e., ultraviolet-B radiation) whereas intake by nutrition traditionally plays a relatively minor role. Dietary guidelines for vitamin D are based on a consensus that serum 25-hydroxyvitamin D (25[OH]D) concentrations are used to assess vitamin D status, with the recommended target concentrations ranging from ≥25 to ≥50 nmol/L (≥10-≥20 ng/mL), corresponding to a daily vitamin D intake of 10 to 20 µg (400-800 international units). Most populations fail to meet these recommended dietary vitamin D requirements. In Europe, 25(OH)D concentrations <30 nmol/L (12 ng/mL) and <50 nmol/L (20 ng/mL) are present in 13.0 and 40.4% of the general population, respectively. This substantial gap between officially recommended dietary reference intakes for vitamin D and the high prevalence of vitamin D deficiency in the general population requires action from health authorities. Promotion of a healthier lifestyle with more outdoor activities and optimal nutrition are definitely warranted but will not erase vitamin D deficiency and must, in the case of sunlight exposure, be well balanced with regard to potential adverse effects such as skin cancer. Intake of vitamin D supplements is limited by relatively poor adherence (in particular in individuals with low-socioeconomic status) and potential for overdosing. Systematic vitamin D food fortification is, however, an effective approach to improve vitamin D status in the general population, and this has already been introduced by countries such as the US, Canada, India, and Finland. Recent advances in our knowledge on the safety of vitamin D treatment, the dose-response relationship of vitamin D intake and 25(OH)D levels, as well as data on the effectiveness of vitamin D fortification in countries such as Finland provide a solid basis to introduce and modify vitamin D food fortification in order to improve public health with this likewise cost-effective approach.

10.
Anticancer Res ; 38(2): 1111-1120, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29374748

RESUMO

The European Commission's Scientific Committee on Health, Environmental and Emerging Risks and the World Health Organization recently published reports which concluded that a large proportion of melanoma and non-melanoma skin cancer is attributable to sunbed use, and that there is no need to use sunbeds as there are no health benefits and they are not needed to achieve an optimal vitamin D level. The overall conclusion from both bodies was that there is no safe limit for UV irradiance from sunbeds. We are, however, deeply concerned that these assessments appear to be based on an incomplete, unbalanced and non-critical evaluation of the literature. Therefore, we rebut these conclusions by addressing the incomplete analysis of the adverse health effects of UV and sunbed exposure (what is 'safe'?) and the censored representation of beneficial effects, not only but especially from vitamin D production. The stance taken by both agencies is not sufficiently supported by the data and in particular, current scientific knowledge does not support the conclusion sunbed use increases melanoma risk.


Assuntos
Meio Ambiente , Melanoma/etiologia , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Cutâneas/etiologia , Banho de Sol , Raios Ultravioleta/efeitos adversos , Grupos Étnicos , Humanos , Organização Mundial da Saúde
11.
Anticancer Res ; 38(2): 1165-1171, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29374754

RESUMO

BACKGROUND/AIM: To optimize public health campaigns concerning UV exposure, it is important to characterize factors that influence UV-induced cutaneous vitamin D production. This systematic review and meta-analysis investigated the impact of different individual and environmental factors including exposed body surface area (BSA), UVB dose and vitamin D status, on serum 25(OH)D concentration. MATERIALS AND METHODS: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses, and Meta-analysis of Observational studies in Epidemiology guidelines, a systematic literature search was conducted (MEDLINE; 01/1960-07/2016) investigating the impact of these factors on vitamin D status after artificial UV exposure as main outcome measure. Summary mean differences [and 95% confidence interval (CI)] were derived from random-effects meta-analysis to account for possible heterogeneity across studies. Meta-regression was conducted to account for impact of UVB dose, baseline 25(OH)D level and BSA. RESULTS: We identified 15 studies, with an estimated mean 25(OH)D rise per standard erythema dose (SED) of 0.19 nmol/l (95% CI 0.11-0.26 nmol/l). Results from meta-regression suggest a significant impact of UV dose and baseline 25(OH)D concentration on serum 25(OH)D level (p<0.01). Single UVB doses between 0.75 and 3 SED resulted in the highest rise of serum 25(OH)D per dose unit. BSA exposed had a smaller, non-proportional, not significant impact. Partial BSA exposure resulted in relatively higher rise compared to whole-body exposure (e.g. exposure of face and hands caused an 8-fold higher rise of serum 25(OH)D concentration/SED/1% BSA compared to whole-body exposure). Our findings support previous reports, estimating that the half-life of serum 25(OH)D varies depending on different factors. CONCLUSION: Our results indicate that partial BSA exposure (e.g. 10%) with moderate UV doses (e.g. 1 SED) is effective in generating or maintaining a healthy vitamin D status. However, due to limitations that include possible confounding factors such as skin type, which could not be considered, these findings should be interpreted with caution.


Assuntos
Neoplasias Induzidas por Radiação/prevenção & controle , Neoplasias Cutâneas/prevenção & controle , Pele/metabolismo , Raios Ultravioleta/efeitos adversos , Vitamina D/análogos & derivados , Vitamina D/metabolismo , Superfície Corporal , Humanos , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/metabolismo , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/metabolismo , Vitamina D/sangue
12.
Anticancer Res ; 38(2): 1187-1199, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29374757

RESUMO

BACKGROUND: There is an ongoing debate whether solarium use (indoor tanning/artificial UV) may increase the risk for primary cutaneous malignant melanoma. AIM: A systematic literature search was conducted using MEDLINE and ISI Web of Science. Included studies were critically assessed regarding their risk of bias, and methodological shortcomings. Levels of evidence and grades of recommendation were determined according to guidelines of the Oxford Centre for Evidence-Based Medicine. Summary risk estimates and 95% confidence intervals for four different outcomes (ever exposure, exposure at younger age, high/low exposure vs. non-exposure) were derived from random-effects meta-analyses to account for possible heterogeneity across studies. RESULTS: Two cohort and twenty-nine case-control studies were eligible. Overall, quality of included studies was poor as a result of severe limitations, including possible recall and selection bias, and due to lack of interventional trials. Summary risk estimates suggested a weak association (odds ratio (OR)=1.19, 95% confidence interval (CI)=1.04-1.35, p=0.009) for ever-exposure to UV radiation from a solarium with melanoma risk. However, sensitivity analyses did not show an association for studies from Europe (OR=1.10; 95%CI=0.95-1.27, p=0.218), studies with low risk of bias (OR=1.15; 95%CI=0.94-1.41, p=0.179), and studies conducted after 1990 (OR 1.09; 95%CI=0.93-1.29, p=0.295). Moreover, moderate associations were found for first exposure to UV radiation from a solarium at younger age (<25 years) and high exposure (>10 sessions in lifetime) with melanoma risk. However, for all outcomes analyzed, overall study quality and resulting levels of evidence (3a-) and grades of recommendation (D) were low due to lack of interventional studies and severe limitations including unobserved or unrecorded confounding. CONCLUSION: Current scientific knowledge is mainly based on observational studies with poor quality data, which report associations but do not prove causality. At present, there is no convincing evidence that moderate/responsible solarium use increases melanoma risk.


Assuntos
Medicina Baseada em Evidências , Melanoma/etiologia , Neoplasias Induzidas por Radiação/etiologia , Banho de Sol , Raios Ultravioleta/efeitos adversos , Humanos , Metanálise como Assunto
13.
PLoS Pathog ; 13(6): e1006406, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28640877

RESUMO

Patients suffering from Epidermodysplasia verruciformis (EV), a rare inherited skin disease, display a particular susceptibility to persistent infection with cutaneous genus beta-human papillomavirus (beta-HPV), such as HPV type 8. They have a high risk to develop non-melanoma skin cancer at sun-exposed sites. In various models evidence is emerging that cutaneous HPV E6 proteins disturb epidermal homeostasis and support carcinogenesis, however, the underlying mechanisms are not fully understood as yet. In this study we demonstrate that microRNA-203 (miR-203), a key regulator of epidermal proliferation and differentiation, is strongly down-regulated in HPV8-positive EV-lesions. We provide evidence that CCAAT/enhancer-binding protein α (C/EBPα), a differentiation-regulating transcription factor and suppressor of UV-induced skin carcinogenesis, directly binds the miR-203 gene within its hairpin region and thereby induces miR-203 transcription. Our data further demonstrate that the HPV8 E6 protein significantly suppresses this novel C/EBPα/mir-203-pathway. As a consequence, the miR-203 target ΔNp63α, a proliferation-inducing transcription factor, is up-regulated, while the differentiation factor involucrin is suppressed. HPV8 E6 specifically down-regulates C/EBPα but not C/EBPß expression at the transcriptional level. As shown in knock-down experiments, C/EBPα is regulated by the acetyltransferase p300, a well-described target of cutaneous E6 proteins. Notably, p300 bound significantly less to the C/EBPα regulatory region in HPV8 E6 expressing keratinocytes than in control cells as demonstrated by chromatin immunoprecipitation. In situ analysis confirmed congruent suprabasal expression patterns of C/EBPα and miR-203 in non-lesional skin of EV-patients. In HPV8-positive EV-lesions both factors are potently down-regulated in vivo further supporting our in vitro data. In conclusion our study has unraveled a novel p300/C/EBPα/mir-203-dependent mechanism, by which the cutaneous HPV8 E6 protein may expand p63-positive cells in the epidermis of EV-patients and disturbs fundamental keratinocyte functions. This may drive HPV-mediated pathogenesis and may potentially also pave the way for skin carcinogenesis in EV-patients.


Assuntos
Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Transformação Celular Viral/genética , Regulação da Expressão Gênica/fisiologia , Queratinócitos/virologia , MicroRNAs/biossíntese , Proteínas Oncogênicas Virais/metabolismo , Linhagem Celular , Imunoprecipitação da Cromatina , Ensaio de Desvio de Mobilidade Eletroforética , Epidermodisplasia Verruciforme/complicações , Epidermodisplasia Verruciforme/virologia , Humanos , Immunoblotting , Imuno-Histoquímica , Hibridização In Situ , Queratinócitos/metabolismo , Infecções por Papillomavirus/complicações , Reação em Cadeia da Polimerase em Tempo Real
14.
Mol Cell Endocrinol ; 453: 96-102, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28526240

RESUMO

The skin represents a pivotal organ for the human body's vitamin D endocrine system, being both the site of ultraviolet (UV)-B-induced vitamin D synthesis and a target tissue for the pluripotent effects of 1,25(OH)2D3 and other biologically active vitamin D metabolites. As many other steroid hormones, 1,25(OH)2D3 exerts its effects via two independent signal transduction pathways: the classical genomic and the non-genomic pathway. While non-genomic effects of 1,25(OH)2D3 are in part exerted via effects on intracellular calcium, genomic effects are mediated by the vitamin D receptor (VDR). Recent findings convincingly support the concept of a new function of the VDR as a tumor suppressor in skin, with key components of the vitamin D endocrine system, including VDR, CYP24A1, CYP27A1, and CYP27B1 being strongly expressed in non-melanoma skin cancer (NMSC). It has now been shown that anti-tumor effects of VDR, that include some of its ligand-induced growth-regulatory effects, are at least in part mediated by interacting in a highly coordinated manner with the p53 family (p53/p63/p73) in response to a large number of alterations in cell homeostasis, including UV-induced DNA damage, a hallmark for skin photocarcinogenesis. Considering the relevance of the vitamin D endocrine system for carcinogenesis of skin cancer, it is not surprising that low 25(OH)D serum concentrations and genetic variants (SNPs) of the vitamin D endocrine system have been identified as potential risk factors for occurrence and prognosis of skin malignancies. In conclusion, an increasing body of evidence now convincingly supports the concept that the vitamin D endocrine system is of relevance for photocarcinogenesis and progression of NMSC and that its pharmacologic modulation by vitamin D, 1,25(OH)2D3, and analogs represents a promising new strategy for prevention and/or treatment of these malignancies.


Assuntos
Carcinogênese/metabolismo , Sistema Endócrino/metabolismo , Neoplasias Induzidas por Radiação/metabolismo , Neoplasias Cutâneas/metabolismo , Pele/metabolismo , Vitamina D/metabolismo , Animais , Cálcio/metabolismo , Citocromos/metabolismo , Dano ao DNA , Humanos , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Pele/patologia , Pele/efeitos da radiação , Neoplasias Cutâneas/prevenção & controle , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Raios Ultravioleta/efeitos adversos , Vitamina D/efeitos da radiação
15.
Photochem Photobiol Sci ; 16(3): 433-444, 2017 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-28054069

RESUMO

During evolution, the ability of many organisms to synthesize vitamin D photochemically represented, and still represents, a major driving factor for the development of life on earth. In humans because not more than 10-20% of the requirement of vitamin D can be satisfied by the diet (under most living conditions in the US and Europe), the remaining 80-90% need to be photochemically synthesized in the skin through the action of solar or artificial ultraviolet-B (UV-B) radiation. The skin is a key organ of the human body's vitamin D endocrine system (VDES), representing both the site of vitamin D synthesis and a target tissue for biologically active vitamin D metabolites. Human keratinocytes contain the enzymatic machinery (CYP27B1) for the synthesis of the biologically most active natural vitamin D metabolite 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), representing an autonomous vitamin D3 pathway. Cutaneous production of 1,25(OH)2D3 may mediate intracrine, autocrine and paracrine effects on keratinocytes and on neighboring cells. Many skin cells (including keratinocytes, sebocytes, fibroblasts, melanocytes, macrophages and other skin immune cells) express the vitamin D receptor (VDR), an absolute pre-requisite for exerting genomic effects of 1,25(OH)2D3 and analogs. The VDR is a member of the superfamily of trans-acting transcriptional regulatory factors, which also contains the steroid and thyroid hormone receptors as well as the retinoid-X receptors (RXR) and retinoic acid receptors (RAR). A large body of evidence, including cDNA microarray analyses of mRNAs, indicates that as many as 500-1000 genes may be controlled by VDR ligands that regulate a broad variety of cellular functions including growth, differentiation, and apoptosis. Clinical and laboratory investigations, including the observation that 1,25(OH)2D3 is very effective in inducing the terminal differentiation and in inhibiting the proliferation of cultured human keratinocytes have resulted in the use of 1,25(OH)2D3 and analogs for the treatment of psoriasis. Focussing on the UV-induced cutaneous synthesis of vitamin D, this review gives an update on the relevance of the VDES and of UV radiation for the management of psoriasis and other inflammatory skin diseases.


Assuntos
Sistema Endócrino/efeitos dos fármacos , Inflamação/tratamento farmacológico , Dermatopatias/tratamento farmacológico , Raios Ultravioleta , Vitamina D/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sistema Endócrino/metabolismo , Humanos , Inflamação/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Dermatopatias/metabolismo , Dermatopatias/patologia , Vitamina D/metabolismo
16.
Cell Death Discov ; 2: 16063, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27785369

RESUMO

Macrophages represent key players of the immune system exerting highly effective defense mechanisms against microbial infections and cancer that include phagocytosis and programmed cell removal. Recent findings highlight the relevance of the non-neuronal cholinergic system for the regulation of macrophage function that opens promising new concepts for the treatment of infectious diseases and cancer. This mini review summarizes our present knowledge on this topic and gives an outlook on future developments.

17.
Rev Endocr Metab Disord ; 17(3): 405-417, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27447175

RESUMO

Vitamin D represents one of the major driving factors for the development of life on earth and for human evolution. While up to 10-20 % of the human organism's requirements in vitamin D can be obtained by the diet (under most living conditions in the USA and Europe), approximately 90 % of all needed vitamin D has to be photosynthesized in the skin through the action of the sun (ultraviolet-B (UV-B)). The skin represents a key organ of the human body's vitamin D endocrine system (VDES), being both the site of vitamin D synthesis and a target tissue for biologically active vitamin D metabolites. It was shown that human keratinocytes possess the enzymatic machinery (CYP27B1) for the synthesis of the biologically most active natural vitamin D metabolite 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), representing an autonomous vitamin D3 pathway. Cutaneous production of 1,25(OH)2D3 may exert intracrine, autocrine, and paracrine effects on keratinocytes and on neighboring cells. Many skin cells (including keratinocytes, sebocytes, fibroblasts, melanocytes, and skin immune cells) express the vitamin D receptor (VDR), an absolute pre-requisite for the mediation of genomic effects of 1,25(OH)2D3 and analogs. VDR belongs to the superfamily of trans-acting transcriptional regulatory factors, which includes the steroid and thyroid hormone receptors as well as the retinoid X receptors (RXR) and retinoic acid receptors (RAR). Numerous studies, including cDNA microarray analyses of messenger RNAs (mRNAs), indicate that as many as 500-1000 genes may be regulated by VDR ligands that control various cellular functions including growth, differentiation, and apoptosis. The observation that 1,25(OH)2D3 is extremely effective in inducing the terminal differentiation and in inhibiting the proliferation of cultured human keratinocytes has resulted in the use of vitamin D analogs for the treatment of psoriasis. This review gives an historical view and summarizes our present knowledge about the relevance of the VDES for the management of inflammatory and malignant skin diseases.


Assuntos
Sistema Endócrino/metabolismo , Inflamação/metabolismo , Receptores de Calcitriol/metabolismo , Dermatopatias/metabolismo , Neoplasias Cutâneas/metabolismo , Pele/metabolismo , Vitamina D/metabolismo , Humanos , Inflamação/tratamento farmacológico , Dermatopatias/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico
19.
Anticancer Res ; 36(3): 1429-37, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26977047

RESUMO

Vitamin D deficiency is common and associated with higher risk for and unfavourable outcome of many diseases. Limited data exist on genetic determinants of serum 25(OH)D concentration. In a cohort of the LURIC study (n=2974, median 25(OH)D concentration 15.5 ng/ml), we tested the hypothesis that variants (SNPs, n=244) of several genes (n=15) involved in different aspects of skin pigmentation, including melanosomal biogenesis (ATP7A, DTNBP1, BLOC1S5, PLDN, PMEL), melanosomal transport within melanocytes (RAB27A, MYO5A, MLPH); or various melanocyte signaling pathways (MC1R, MITF, PAX3, SOX10, DKK1, RACK1, CNR1) are predictive of serum 25(OH)D levels. Eleven SNPs located in 6 genes were associated (p<0.05) with low or high serum 25(OH)D levels, 3 out of these 11 SNPs reached the aimed significance level after correction for multiple comparisons (FDR). In the linear regression model adjusted for sex, body mass index (BMI), year of birth and month of blood sample rs7565264 (MLPH), rs10932949 (PAX3), and rs9328451 (BLOC1S5) showed a significant association with 25(OH)D. The combined impact on variation of 25(OH)D serum levels (coefficient of determination (R(2))) for the 11 SNPs was 1.6% and for the 3 SNPs after FDR 0.3%. In Cox Regression we identified rs2292881 (MLPH) as having a significant association (advantage) with overall survival. Kaplan-Meier analysis did not show any significant impact of individual SNPs on overall survival. In conclusion, these results shed new light on the role of sunlight, skin pigmentation and vitamin D for human evolution.


Assuntos
Polimorfismo de Nucleotídeo Único/genética , Pigmentação da Pele/genética , Vitamina D/análogos & derivados , Vitamina D/biossíntese , Índice de Massa Corporal , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Melanócitos/metabolismo , Luz Solar , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/genética
20.
Anticancer Res ; 36(3): 1439-44, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26977048

RESUMO

Vitamin D deficiency represents a major health issue. It is a worldwide endemic and is associated with a broad variety of severe diseases. The skin is a key tissue for the human body's vitamin D endocrine system. It represents a target tissue for biologically active vitamin D metabolites. Approximately 90% of the human body's requirements of vitamin D have to be synthesised in the skin by the action of UVB-radiation. However, individual factors that influence a person's cutaneous synthesis of vitamin D are still not well understood. In our present prospective study we investigated the effect of UVB narrow band (UVBnb, 311 nm) and PUVA phototherapy on 25(OH)D3 serum concentration, in patients with psoriasis, atopic dermatitis and a few cases with other dermatoses (n=41). We found that two weeks of UVBnb treatment resulted in an increase of 25(OH)D3 serum concentration from 11.4 to 20.5 ng/ml (p<0.001), while in contrast PUVA-treatment did not significantly alter vitamin D status. These findings question the hypothesis of a relevant vitamin D metabolizing effect of UVA. Psoriasis patients showed a trend for a stronger increase in 25(OH)D3 serum levels following UVBnb compared to patients with atopic dermatitis. Patients with relatively low baseline serum 25(OH)D3 concentrations had a stronger increase in 25(OH)D3 concentrations compared to patients with relatively high 25(OH)D serum concentrations. In general patients with skin types (Fitzpatrick) I and II (median=14.3 ng/ml) had a higher baseline of 25(OH)D3 serum concentration compared to patients with skin types III (median=11.2 ng/ml) or IV-V (median=12.3 ng/ml), although these differences were not statistically significant (p=0.106). Baseline 25(OH)D3 serum concentrations were correlated with presence of genetic variants (SNPs of VDR, CYP2R1, VDBP/GC) that influence vitamin D status, and with other individual factors such as body mass index, age and gender. We also investigated the effect of phototherapy on blood pressure and a variety of laboratory parameters such as CRP, HbA1c, LDL, HDL, triglycerides and cholesterol. In conclusion, our pilot study shows that UVBnb phototherapy efficiently increases 25(OH)D3 serum concentration and reports interesting preliminary findings that have to be re-evaluated in larger follow-up studies.


Assuntos
Calcifediol/sangue , Dermatite Atópica/sangue , Psoríase/sangue , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Dermatite Atópica/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fototerapia/métodos , Polimorfismo de Nucleotídeo Único/genética , Estudos Prospectivos , Psoríase/genética , Raios Ultravioleta , Terapia Ultravioleta/métodos , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA