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1.
J Diabetes Res ; 2019: 8289741, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31583252

RESUMO

Objective: To investigate the effect of single nucleotide polymorphisms (SNPs) of the key genes in vitamin D metabolic pathway on the serum 25(OH)D level after long-term vitamin D3 supplementation and provide a theoretical basis for rational vitamin D3 supplementation in diabetic patients with different genetic backgrounds. Methods: Patients with type 2 diabetes (T2DM) who met the inclusive criteria were given 800 IU of vitamin D3 daily for 30 consecutive months. Serum 25(OH)D levels was measured at enrollment and every 6 months after enrollment. The average value of four-time measurements represented individual serum 25(OH)D level during vitamin D3 supplementation. Multiplex TaqMan genotyping was used to determine the distribution of eight candidate SNPs in genes of DHCR7, CYP2R1, CYP27B1, CYP24A1, and VDR, which are key genes in the vitamin D metabolic pathway, in diabetic patients. Results: At baseline, the average serum 25(OH)D level was 22.71 ± 6.87 ng/mL, and 17.9% of patients had a ≥30 ng/mL level. During supplementation, the level of 25(OH)D increased significantly at each time point, and the average 25(OH)D level increased to 30.61 ± 5.04 ng/mL; however, there were 44.6% of patients whose serum 25(OH)D levels were still below 30 ng/mL. In the patients with CYP27B1 (rs10877012) G/T genotype, 71.79% achieved sufficient level of 25(OH)D, which was significantly higher than the other two genotypes (P < 0.05). Compared with those with T/T genotype, the RR of the patients with rs10877012 for <30 ng/mL level was 0.544 (95% CI: 0.291-0.917), and the RR after adjusting age and outdoor activity was 0.560 (95% CI: 0.292-0.970). Conclusion: The serum 25(OH)D level in patients with diabetes mellitus after long-term vitamin D3 supplementation is associated with CYP27B1 polymorphism. Patients with rs10877012 G/T allele have a better response to vitamin D3 supplementation. Trial Registration: This trial is registered with ChiCTR-IPC-17012657.


Assuntos
Colecalciferol/uso terapêutico , Diabetes Mellitus Tipo 2/genética , Suplementos Nutricionais , Predisposição Genética para Doença , Deficiência de Vitamina D/genética , Vitamina D/análogos & derivados , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Idoso , Colecalciferol/administração & dosagem , Colestanotriol 26-Mono-Oxigenase/genética , Família 2 do Citocromo P450/genética , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Polimorfismo de Nucleotídeo Único , Receptores de Calcitriol/genética , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D3 24-Hidroxilase/genética
2.
Nutrients ; 11(9)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500220

RESUMO

In chronic obstructive pulmonary disease (COPD), the bronchial epithelium is the first immune barrier that is triggered by cigarette smoke. Although vitamin D (vitD) has proven anti-inflammatory and antimicrobial effects in alveolar macrophages, little is known about the direct role of vitD on cigarette smoke-exposed bronchial epithelial cells. We examined the effects of vitD on a human bronchial epithelial cell line (16HBE) and on air-liquid culture of primary bronchial epithelial cells (PBEC) of COPD patients and controls exposed for 24 h to cigarette smoke extract (CSE). VitD decreased CSE-induced IL-8 secretion by 16HBE cells, but not by PBEC. VitD significantly increased the expression of the antimicrobial peptide cathelicidin in 16HBE and PBEC of both COPD subjects and controls. VitD did not affect epithelial to mesenchymal transition or epithelial MMP-9 expression and was not able to restore impaired wound healing by CSE in 16HBE cells. VitD increased the expression of its own catabolic enzyme CYP24A1 thereby maintaining its negative feedback. In conclusion, vitD supplementation may potentially reduce infectious exacerbations in COPD by the upregulation of cathelicidin in the bronchial epithelium.


Assuntos
Brônquios/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Doença Pulmonar Obstrutiva Crônica/metabolismo , Fumaça/efeitos adversos , Produtos do Tabaco/efeitos adversos , Vitamina D/análogos & derivados , Idoso , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Brônquios/metabolismo , Brônquios/patologia , Estudos de Casos e Controles , Linhagem Celular , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Interleucina-8/metabolismo , Masculino , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/patologia , Receptores de Calcitriol/agonistas , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Vitamina D/metabolismo , Vitamina D/farmacologia , Vitamina D3 24-Hidroxilase/genética , Vitamina D3 24-Hidroxilase/metabolismo
3.
BMJ ; 366: l4410, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371314

RESUMO

OBJECTIVE: To determine if genetically increased serum calcium levels are associated with improved bone mineral density and a reduction in osteoporotic fractures. DESIGN: Mendelian randomisation study. SETTING: Cohorts used included: the UK Biobank cohort, providing genotypic and estimated bone mineral density data; 25 cohorts from UK, USA, Europe, and China, providing genotypic and fracture data; and 17 cohorts from Europe, providing genotypic and serum calcium data (summary level statistics). PARTICIPANTS: A genome-wide association meta-analysis of serum calcium levels in up to 61 079 individuals was used to identify genetic determinants of serum calcium levels. The UK Biobank study was used to assess the association of genetic predisposition to increased serum calcium with estimated bone mineral density derived from heel ultrasound in 426 824 individuals who had, on average, calcium levels in the normal range. A fracture genome-wide association meta-analysis comprising 24 cohorts and the UK Biobank including a total of 76 549 cases and 470 164 controls, who, on average, also had calcium levels in the normal range was then performed. RESULTS: A standard deviation increase in genetically derived serum calcium (0.13 mmol/L or 0.51 mg/dL) was not associated with increased estimated bone mineral density (0.003 g/cm2, 95% confidence interval -0.059 to 0.066; P=0.92) or a reduced risk of fractures (odds ratio 1.01, 95% confidence interval 0.89 to 1.15; P=0.85) in inverse-variance weighted mendelian randomisation analyses. Sensitivity analyses did not provide evidence of pleiotropic effects. CONCLUSIONS: Genetic predisposition to increased serum calcium levels in individuals with normal calcium levels is not associated with an increase in estimated bone mineral density and does not provide clinically relevant protection against fracture. Whether such predisposition mimics the effect of short term calcium supplementation is not known. Given that the same genetically derived increase in serum calcium is associated with an increased risk of coronary artery disease, widespread calcium supplementation in the general population could provide more risk than benefit.


Assuntos
Densidade Óssea/genética , Cálcio/sangue , Predisposição Genética para Doença , Fraturas por Osteoporose/sangue , Fraturas por Osteoporose/genética , Adenosina Trifosfatases/genética , Diacilglicerol Quinase/genética , Feminino , Fator de Transcrição GATA3/genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Análise da Randomização Mendeliana , Polimorfismo de Nucleotídeo Único , Receptores de Detecção de Cálcio/genética , Medição de Risco , Vitamina D3 24-Hidroxilase/genética , Vitamina K Epóxido Redutases/genética
4.
Kidney Blood Press Res ; 44(4): 870-877, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31288237

RESUMO

BACKGROUND/AIMS: The CYP24A1 gene encodes the vitamin D 24-hydroxylase enzyme, which hydroxylates active forms of vitamin D into inactive forms. Biallelic mutations in the CYP24A1 gene can lead to elevated levels of active vitamin D metabolites and, consequently, to hypercalcemia, hypercalciuria, nephrocalcinosis, and nephrolithiasis; however, monoallelic mutations have been associated only with milder phenotypes. In the present manuscript, we report the case of a young male patient who presented hypercalcemia and nephrolithiasis, suppressed parathormone, and elevated 1,25 dihydroxy vitamin D levels. METHODS: Biochemical analyses were performed on Cobas 8000, F. Hoffmann-La Roche AG, Basel, Switzerland. The proband was initially evaluated for occult malignancies by body imaging, serum electrophoresis, and tumor markers, which did not reveal any pathology. DNA samples of the proband and his sibling were then examined using Sanger sequencing. RESULTS: Genetic analysis revealed 2 compound heterozygous CYP24A1 mutations (p.L148P and p.R223*). The novel nonsense CYP24A1 mutation, p.R223*, was also found heterozygously in other family members with a medical history of nephrolithiasis. CONCLUSIONS: The identification of this gene mutation causing hypercalcemia, hypercalciuria, and renal stones allows the specific management of endogenous vitamin D production.


Assuntos
Cálculos Renais/genética , Mutação , Vitamina D3 24-Hidroxilase/genética , Humanos , Hipercalcemia , Hipercalciúria , Masculino , Análise de Sequência de DNA , Irmãos , Vitamina D/sangue , Adulto Jovem
5.
Genes (Basel) ; 10(8)2019 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-31357732

RESUMO

Vitamin D is mostly known for its role in bone and calcium metabolism. However, studies have suggested that it also has inhibitory effects on tumor development and progression. Genetic variants close to genes that encode crucial enzymes for the synthesis (DHCR7 rs12785878), metabolism (CYP2R1 rs2060793) and degradation (CYP24A1 rs6013897) of vitamin D have been associated with serum levels of vitamin D. The aim of this case-control study was to determine the effect of these variants in the vitamin D pathway on the susceptibility to thyroid cancer. Five hundred patients with differentiated thyroid cancer and 500 controls were genotyped for the DHCR7 rs12785878, CYP2R1 rs2060793, and CYP24A1 rs6013897 variants. Genotype and allele frequencies were compared between patients and controls. The DHCR7 rs12785878 minor allele was associated with thyroid cancer under an additive (OR 1.38, 95% CI 1.15-1.65, p = 0.0004) and codominant (OR 1.88, 95% CI 1.30-2.74, p = 0.0021) model. These findings suggest that DHCR7 polymorphisms may be associated with an increased risk of thyroid cancer due to an effect of this gene on circulating vitamin D levels.


Assuntos
Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Polimorfismo de Nucleotídeo Único , Neoplasias da Glândula Tireoide/genética , Vitamina D/metabolismo , Adulto , Colestanotriol 26-Mono-Oxigenase/genética , Família 2 do Citocromo P450/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vitamina D/genética , Vitamina D3 24-Hidroxilase/genética
6.
Int J Infect Dis ; 84: 80-88, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31075507

RESUMO

BACKGROUND AND AIMS: It has been demonstrated that 1,25-hydroxyvitamin-D3-24-hydroxylase, encoded by CYP24A1 gene, is a key enzyme that neutralizes the active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] in response to hepatitis C virus (HCV) infection. This study aimed to investigate whether CYP24A1 genetic variation is associated with HCV infection outcomes. METHODS: 848 HCV chronically infected subjects, 507 natural clearance subjects, and 1017 uninfected controls were enrolled. Nine single nucleotide polymorphisms (SNPs) in theCYP24A1 gene were genotyped using the Sequenom MassARRAY platform. RESULTS: After adjusting for age, gender, and routes of infection, logistic regression analyses showed that rs6013897-A was associated with an elevated risk of HCV infection (P<0.05). In addition, this study has also demonstrated that rs6068816-T significantly reduced the risk of chronic HCV infection, while rs3787557-C, rs6022999-G, and rs2248359-T significantly increased the risk of chronic HCV infection (all P<0.05). Haplotype analysis suggested that, compared to the most frequent Trs6068816Trs3787557Ars6022999Crs2248359 haplotype, the CTGT haplotype (adjusted OR=1.376, 95% CI=1.092-1.735, P=0.007) and CCAC haplotype (adjusted OR=1.483, 95% CI=1.139-1.929, P=0.003) were associated with an increased risk of chronic HCV infection. CONCLUSION: These findings indicate that SNPs in CYP24A1 gene may contribute to the risk of HCV infection and chronic HCV infection among a high-risk Chinese population.


Assuntos
Hepatite C Crônica/etiologia , Polimorfismo de Nucleotídeo Único , Vitamina D3 24-Hidroxilase/genética , Vitamina D/metabolismo , Adulto , Feminino , Haplótipos , Hepatite C Crônica/genética , Humanos , Masculino , Redes e Vias Metabólicas , Pessoa de Meia-Idade , Fatores de Risco
7.
DNA Cell Biol ; 38(3): 243-249, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30724597

RESUMO

CYP24A1 plays important roles in antiproliferative effects, which have been proved in many human tumor cells. Polymorphisms in CYP24A1 may affect the risk of lung cancer, but the results remained inconclusive. To enhance the understanding of possible relationship between CYP24A1 polymorphism rs6068816 and lung cancer risks, we first carried out this case-control study among Chinese female nonsmokers, including 345 lung cancer patients and 351 noncancer controls. Our results revealed that individuals carrying CT and CC genotype were associated with decreasing lung cancer risk (adjusted odds ratios were 0.71 and 0.59, and 95% confidence intervals were 0.52-0.97 and 0.35-0.99, p-values were 0.031 and 0.048, respectively). Patients carrying allele-T showed lower hazard risks, especially in adenocarcinoma and advanced stage cancers. We also found that subjects with allele-T showed a relatively low risk of lung cancer when they were exposed to oil fume. But neither additive scale nor multiplicative scale revealed interactions between allele-T and environmental exposures, including oil fume, coal fuel fume, and passive smoking. Overall, these findings indicated that CYP24A1 polymorphism rs6068816 could be significantly associated with susceptibility of lung cancer in Chinese female nonsmokers.


Assuntos
Neoplasias Pulmonares/genética , Vitamina D3 24-Hidroxilase/genética , Vitamina D3 24-Hidroxilase/fisiologia , Adenocarcinoma/genética , Adulto , Idoso , Alelos , Grupo com Ancestrais do Continente Asiático/genética , Estudos de Casos e Controles , China , Exposição Ambiental , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Genótipo , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , não Fumantes , Razão de Chances , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
8.
Cell Death Dis ; 10(1): 25, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30631035

RESUMO

Acidosis is a significant feature of the tumor microenvironment in glioma, and it is closely related to multiple biological functions of cancer stem cells. Here, we found that the self-renewal ability, the mitochondrial activity and ATP production were elevated in stem cell-like glioma cells (SLCs) under acidic microenvironment, which promoted and maintained the stemness of SLCs. Under acidosis, 25-hydroxy vitamin D3-24-hydroxylase (CYP24A1) was upregulated and catalyzed the fast degradation of 1α,25(OH)2D3. We further revealed that the active form of vitamin D (1α,25(OH)2D3) could inhibit the expression of stemness markers, attenuate acidosis-induced increase of self-renewal ability and mitochondrial respiration in stem cell-like glioma cells. Our study indicates that the acidosis-CYP24A1-vitamin D pathway may be a key regulator of the cancer stem cell phenotype in malignant glioma and point out the potential value for the utilization of vitamin D to target cancer stem cells and to restrain the growth of malignant glioma in the future.


Assuntos
Acidose/metabolismo , Neoplasias Encefálicas/metabolismo , Calcitriol/metabolismo , Glioma/metabolismo , Mitocôndrias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Vitamina D3 24-Hidroxilase/metabolismo , Acidose/induzido quimicamente , Acidose/genética , Animais , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Autorrenovação Celular/efeitos dos fármacos , Meios de Cultura Livres de Soro/química , Glioma/patologia , Xenoenxertos , Humanos , Ácido Clorídrico/farmacologia , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mitocôndrias/genética , Fenótipo , Hidróxido de Sódio/farmacologia , Transcriptoma , Microambiente Tumoral/efeitos dos fármacos , Vitamina D3 24-Hidroxilase/genética
9.
Fetal Pediatr Pathol ; 38(1): 44-56, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30633617

RESUMO

BACKGROUND: Biallelic pathogenic variants in CYP24A1 can cause idiopathic infantile hypercalcemia (HCINF). METHODS: We report 2 additional molecular abnormalities in 2 Chinese children with CHINF1. RESULTS: Biallelic variants in CYP24A1 were found in two patients. Patient One was compound heterozygous for c.449 + 1G > T and c.1426_1427delCT. Patient Two was compound heterozygous for c.1310C > A and c.1426_1427delCT. The c.1310C > A and c.449 + 1G > T were two different novel CYP24A1 variants. Multiple computational tools predicted that both impact protein function. A total of 36 variants have been previously reported in patients with HCINF1, of which 27 were classified as pathogenic or likely pathogenic and nine as uncertain clinical significance. CONCLUSION: Genetic tests are helpful in order to counsel the susceptible individuals to avoid vitamin D and take preventive measures in order to avoid complications.


Assuntos
Hipercalcemia/genética , Doenças do Recém-Nascido/genética , Erros Inatos do Metabolismo/genética , Vitamina D3 24-Hidroxilase/genética , Grupo com Ancestrais do Continente Asiático/genética , Feminino , Variação Genética , Humanos , Lactente , Masculino , Linhagem
10.
J Steroid Biochem Mol Biol ; 189: 240-247, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30654105

RESUMO

Active vitamin D (1,25(OH)2D) has been shown to regulate numerous cell processes in mammary cells. Degradation of 1,25(OH)2D is initiated by the mitochondrial enzyme, 25-hydroxyvitamin D 24-hydroxylase (CYP24 A1), and provides local control of 1,25(OH)2D bioactivity. Several reports of the association between elevated CYP24 A1 activity and breast cancer incidence, suggest that CYP24 A1 may be a target for therapeutic intervention. Whether CYP24 A1 activity within the mammary epithelium regulates 1,25(OH)2D levels and mammary gland development is yet to shown. We have used a conditional knockout of the Cyp24a1 gene specifically in the mammary epithelium to demonstrate reduced terminal end bud number, ductal outgrowth and branching during puberty and alveologenesis at early pregnancy, by inhibiting proliferation but not apoptosis in both basal and luminal MECs. In vitro study showed increased sensitivity of luminal MECs to lower levels of 1,25(OH)2D with the ablation of Cyp24a1 activity. In summary, Cyp24a1 within MECs plays an important role in modulating postnatal and pregnancy-associated mammary gland development which provides support for inhibiting CYP24 A1 as a potential approach to activating the vitamin D pathway in breast cancer prevention and therapy.


Assuntos
Deleção de Genes , Glândulas Mamárias Animais/metabolismo , Vitamina D3 24-Hidroxilase/genética , Vitamina D/metabolismo , Animais , Proliferação de Células , Feminino , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/crescimento & desenvolvimento , Glândulas Mamárias Animais/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Maturidade Sexual , Vitamina D/análogos & derivados , Vitamina D3 24-Hidroxilase/metabolismo
11.
J Steroid Biochem Mol Biol ; 186: 56-60, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30236486

RESUMO

1,25-Dihydroxyvitamin D3 (1,25(OH)2D) elicits a transcriptional response in the intestines. Assessments of this response are often derived from crude tissue homogenates and eliminate the ability to discriminate among different cell types. Here, we used an RNA in situ hybridization assay, RNAScope (Advanced Cell Diagnostics, Newark, CA), to identify the cells in the intestine that respond to 1,25(OH)2D with expression of cytochrome P450 family 24 subfamily A member 1 (Cyp24a1) mRNA. Mice were gavaged with a single bolus dose of 1,25(OH)2D to target the duodenum or a glucuronic acid conjugate of 1,25(OH)2D, ß-G-1,25(OH)2D, to target the colon. QRT-PCR analysis of Cyp24a1 mRNA verified that the 1,25(OH)2D-induced responses were present. RNAScope revealed that the mRNA response present after six hours is limited to mature enterocytes exposed to the intestinal lumen in both the duodenum and colon. No detectable expression was observed in goblet cells, lamina propria, muscularis mucosa muscle, submucosa and submucosal lymphoid follicles, or tunica muscularis. Our findings have identified epithelial enterocytes to be the intestinal targets for 1,25(OH)2D in both the duodenum and colon.


Assuntos
Intestinos/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Vitamina D3 24-Hidroxilase/genética , Vitamina D/análogos & derivados , Vitaminas/farmacologia , Animais , Colo/citologia , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/ultraestrutura , Duodeno/citologia , Duodeno/efeitos dos fármacos , Duodeno/metabolismo , Duodeno/ultraestrutura , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/ultraestrutura , Intestinos/citologia , Intestinos/ultraestrutura , Masculino , Camundongos , RNA Mensageiro/genética , Vitamina D/farmacologia
12.
J Steroid Biochem Mol Biol ; 186: 110-116, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30296587

RESUMO

A proportion of circulating 25-hydroxy vitamin D3 (25(OH)D3)) undergoes epimerization to form C3-epi 25(OH)D3 and C3-epi 1,25(OH)2D3. These epimers have less calcaemic activity than non-epimerized metabolites and are not differentiated by many immunoassays when reporting total 25(OH)D3 levels. This study aimed to compare the effect of exposure to ultraviolet radiation (UVR) and oral vitamin D3 supplementation on vitamin D C3-epimer levels. C57Bl/6 female mice were fed either vitamin D-sufficient (vitamin D3 2000 IU/kg) or -deficient diets (no vitamin D3) for 4 weeks. Among the vitamin D-deficient group, the shaved backs of half were irradiated daily for 4 days with 1 kJ/m2 UVR, followed by twice weekly irradiation for 4 weeks. Despite similar 25(OH)D3 levels, the UV-irradiated group had a lower proportion of C3-epi 25(OH)D3 at week 7 (p < 0.05) and week 9 (p < 0.01). C3-epimer concentrations and %C3-epi 25(OH)D3 were also analysed in serum samples from two human clinical trials. These trials investigated the effect of high dose oral vitamin D3 supplementation and narrowband UVB phototherapy, respectively. Serum 25(OH)D3 and the %C3-epi 25(OH)D3 levels measured at 12 months after oral vitamin D3 supplementation were not significantly different to those measured at the time of maximal effect of phototherapy (2 months). Thus, the proportion of 25(OH)D3 that undergoes epimerization is greater with oral vitamin D3 supplementation than exposure to UVR in mice, but not in humans. This important difference between human and murine vitamin D metabolism warrants consideration when interpreting animal studies.


Assuntos
Calcifediol/sangue , Deficiência de Vitamina D/sangue , Vitamina D/sangue , Vitaminas/sangue , Administração Oral , Animais , Calcifediol/administração & dosagem , Calcifediol/uso terapêutico , Colestanotriol 26-Mono-Oxigenase/genética , Dieta , Suplementos Nutricionais/análise , Feminino , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Raios Ultravioleta , Terapia Ultravioleta , Vitamina D/administração & dosagem , Vitamina D/uso terapêutico , Deficiência de Vitamina D/tratamento farmacológico , Deficiência de Vitamina D/genética , Deficiência de Vitamina D/terapia , Vitamina D3 24-Hidroxilase/genética , Vitaminas/administração & dosagem , Vitaminas/uso terapêutico
13.
Clin Exp Hypertens ; 41(5): 460-465, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30192652

RESUMO

Vitamin D deficiency can lead to high blood pressure. Polymorphisms in the vitamin D hydroxylase gene have been associated with serum vitamin D levels in some Western countries. The aim of this study was to investigate whether polymorphisms of hydroxylase genes in the vitamin D metabolic pathway contribute to hypertension by affecting serum vitamin D status in a Han Chinese population. We selected four single nucleotide polymorphisms (SNPs; rs1993116 and rs10741657 of CYP2R1; rs4809957 and rs6068816 of CYP24A1) for genotyping in 525 control subjects and 324 hypertensive patients, and detected vitamin D levels in blood in subsets of these groups. The results showed that rs1993116 and rs10741657 were associated with a reduced risk of hypertension. The odds ratios, 95% confidence intervals, and p values from the adjusted additive and dominant models were 0.788 (0.644-0.963, p = 0.02) and 0.719 (0.545-0.949, p = 0.02) for rs1993116 and 0.805 (0.66-0.983, p = 0.033) and 0.733 (0.556-0.966, p = 0.028) for rs10741657. A protective effect of CYP2R1 with regard to hypertension was also found in males and non-smokers. The TT genotypes of rs1993116 and rs10741657 were associated with significantly lower systolic blood pressure in treated hypertensive patients (both p = 0.002). No association with hypertension was found for the two SNPs of CYP24A1, and no difference in vitamin D level was found among the three genotypes of the four SNPs. Our results suggest that CYP2R1 polymorphisms are associated with a reduced risk of hypertension independent of the vitamin D level in the Han Chinese population.


Assuntos
Pressão Sanguínea/genética , Colestanotriol 26-Mono-Oxigenase/genética , Família 2 do Citocromo P450/genética , Hipertensão/genética , Vitamina D3 24-Hidroxilase/genética , Vitamina D/sangue , Grupo com Ancestrais do Continente Asiático/genética , Estudos de Casos e Controles , China , Feminino , Genótipo , Humanos , Hipertensão/sangue , Masculino , Pessoa de Meia-Idade , não Fumantes , Polimorfismo de Nucleotídeo Único , Fatores Sexuais
14.
Eur J Med Genet ; 62(11): 103577, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30423445

RESUMO

Loss-of-function mutations in CYP24A1 (MIM 126065 20q13.2), the gene encoding the 24-hydroxylase responsible for 25-OH-D and 1,25-(OH)2D degradation, are identified in about 20% of patients presenting Idiopathic Infantile Hypercalcemia (IIH) (MIM 143880). Common features of this autosomal recessive condition included hypercalcemia with hypercalciuria, suppressed PTH and a high 25-OH-D3:24,25-(OH)2D3 ratio. Medical care mainly relies on sun protection and life-long contraindication of vitamin D to avoid complications such as early nephrocalcinosis and renal failure. Molecular diagnosis therefore keeps a crucial place in the diagnosis of IIH, and genetic counseling should be systematically recommended to prevent vitamin D administration in affected siblings. In this report is described the molecular characterization of a CYP24A1 deletion identified in two unrelated families. This highlights the potential role of CYP24A1 copy number variations (CNV) in IIH. Considering the presence of CNV affecting CYP24A1 in public databases, CNV analysis should be systematically added to the sequencing studies in IIH. Targeted Massively Parallel Sequencing (MPS) study coupled with a CNV detection tool called CovCop is a powerful method to detect genic rearrangement and improve genetic analysis.


Assuntos
Hipercalcemia/diagnóstico , Hipercalcemia/genética , Doenças do Recém-Nascido/diagnóstico , Doenças do Recém-Nascido/genética , Erros Inatos do Metabolismo/diagnóstico , Erros Inatos do Metabolismo/genética , Patologia Molecular , Vitamina D3 24-Hidroxilase/genética , Adolescente , Criança , Pré-Escolar , Variações do Número de Cópias de DNA/genética , Feminino , Humanos , Hipercalcemia/tratamento farmacológico , Hipercalcemia/patologia , Lactente , Doenças do Recém-Nascido/tratamento farmacológico , Doenças do Recém-Nascido/patologia , Mutação com Perda de Função/genética , Masculino , Erros Inatos do Metabolismo/tratamento farmacológico , Erros Inatos do Metabolismo/patologia , Nefrocalcinose/tratamento farmacológico , Nefrocalcinose/genética , Nefrocalcinose/prevenção & controle , Insuficiência Renal/tratamento farmacológico , Insuficiência Renal/genética , Insuficiência Renal/prevenção & controle , Deleção de Sequência/genética , Vitamina D/uso terapêutico
15.
Free Radic Biol Med ; 131: 376-381, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30578920

RESUMO

Chronic kidney disease (CKD) is a worldwide public health problem with an estimated prevalence of 8.2%. This study reports glutathione deficiency, excess oxidative stress, and altered vitamin D metabolism in the kidney of mice fed a high-fat diet (HFD). The levels of GCLC and GCLM gene expression were significantly downregulated and the protein carbonylation level, a hallmark of oxidative damage, was significantly increased in the kidney of HFD-fed mice. While the levels of VD-regulatory genes 1-alpha-hydroxylase (CYP27B1), VDR, and RXRα were significantly downregulated in the kidney of mice fed a HFD, those of 24-hydroxylase (CYP24A1) were significantly elevated. In vitro, GSH deficiency per se causes excess oxidative damage (protein carbonylation), and significantly decreases the levels of VD-regulatory genes (CYP27B1, VDR, and RXRα), but increases levels of CYP24A1 in human renal proximal tubule epithelial cells (RPTEC), similar to findings in the kidney of HFD-fed diabetic mice. L-cysteine supplementation restores GSH and prevents oxidative damage in RPTEC. These studies suggest a potential role of GSH precursor in reducing excess oxidative stress and renal injury that commonly accompanies obesity/diabetes.


Assuntos
25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Diabetes Mellitus Experimental/enzimologia , Glutationa/deficiência , Receptores de Calcitriol/genética , Insuficiência Renal Crônica/enzimologia , Vitamina D3 24-Hidroxilase/genética , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/metabolismo , Animais , Cisteína/farmacologia , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Dieta Hiperlipídica/efeitos adversos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Regulação da Expressão Gênica , Glutamato-Cisteína Ligase/genética , Glutamato-Cisteína Ligase/metabolismo , Humanos , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo , Cultura Primária de Células , Carbonilação Proteica , Receptores de Calcitriol/metabolismo , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/patologia , Receptor X Retinoide alfa/genética , Receptor X Retinoide alfa/metabolismo , Transdução de Sinais , Vitamina D3 24-Hidroxilase/metabolismo
16.
Toxicol Appl Pharmacol ; 364: 55-67, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30552932

RESUMO

Alternative splicing modulates gene function by creating splice variants with alternate functions or non-coding RNA activity. Naturally occurring variants of nuclear receptor (NR) genes with dominant negative or gain-of-function phenotypes have been documented, but their cellular roles, regulation, and responsiveness to environmental stress or disease remain unevaluated. Informed by observations that class I androgen and estrogen receptor variants display ligand-independent signaling in human cancer tissues, we questioned whether the function of class II NRs, like the vitamin D receptor (VDR), would also respond to alternative splicing regulation. Artificial VDR constructs lacking exon 3 (Dex3-VDR), encoding part of the DNA binding domain (DBD), and exon 8 (Dex8-VDR), encoding part of the ligand binding domain (LBD), were transiently transfected into DU-145 cells and stably-integrated into Caco-2 cells to study their effect on gene expression and cell viability. Changes in VDR promoter signaling were monitored by the expression of target genes (e.g. CYP24A1, CYP3A4 and CYP3A5). Ligand-independent VDR signaling was observed in variants lacking exon 8, and a significant loss of gene suppressor function was documented for variants lacking exon 3. The gain-of-function behavior of the Dex8-VDR variant was recapitulated in vitro using antisense oligonucleotides (ASO) that induce the skipping of exon 8 in wild-type VDR. ASO targeting the splice acceptor site of exon 8 significantly stimulated ligand-independent VDR reporter activity and the induction of CYP24A1 above controls. These results demonstrate how alternative splicing can re-program NR gene function, highlighting novel mechanisms of toxicity and new opportunities for the use of splice-switching oligonucleotides (SSO) in precision medicine.


Assuntos
Processamento Alternativo , Neoplasias do Colo/genética , Sistema Enzimático do Citocromo P-450/genética , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , Receptores de Calcitriol/genética , Células CACO-2 , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Neoplasias do Colo/terapia , Citocromo P-450 CYP3A/biossíntese , Citocromo P-450 CYP3A/genética , Sistema Enzimático do Citocromo P-450/biossíntese , Indução Enzimática , Éxons , Terapia Genética/métodos , Humanos , Ligantes , Masculino , Oligonucleotídeos Antissenso/farmacologia , Regiões Promotoras Genéticas , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Receptores de Calcitriol/metabolismo , Vitamina D3 24-Hidroxilase/biossíntese , Vitamina D3 24-Hidroxilase/genética
17.
J Steroid Biochem Mol Biol ; 185: 71-79, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30031146

RESUMO

We have reported that 25-hydroxyvitamin D3 [25(OH)D3] binds to vitamin D receptor and exhibits several biological functions directly in vitro. To evaluate the direct effect of 25(OH)D3 in vivo, we used Cyp27b1 knockout (KO) mice, which had no detectable plasma 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] when fed a diet containing normal Ca and vitamin D. Daily treatment with 25(OH)D3 at 250 µg kg-1 day-1 rescued rachitic phenotypes in the Cyp27b1 KO mice. Bone mineral density, female sexual cycles, and plasma levels of Ca, P, and PTH were all normalized following 25(OH)D3 administration. An elevated Cyp24a1 mRNA expression was observed in the kidneys, and plasma concentrations of Cyp24a1-dependent metabolites of 25(OH)D3 were increased. To our surprise, 1,25(OH)2D3 was detected at a normal level in the plasma of Cyp27b1 KO mice. The F1 to F4 generations of Cyp27b1 KO mice fed 25(OH)D3 showed normal growth, normal plasma levels of Ca, P, and parathyroid hormone, and normal bone mineral density. The curative effect of 25(OH)D3 was considered to depend on the de novo synthesis of 1,25(OH)2D3 in the Cyp27b1 KO mice. This suggests that another enzyme than Cyp27b1 is present for the 1,25(OH)2D3 synthesis. Interestingly, the liver mitochondrial fraction prepared from Cyp27b1 KO mice converted 25(OH)D3 to 1,25(OH)2D3. The most probable candidate is Cyp27a1. Our findings suggest that 25(OH)D3 may be useful for the treatment and prevention of osteoporosis for patients with chronic kidney disease.


Assuntos
25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Conservadores da Densidade Óssea/farmacologia , Calcifediol/farmacologia , Calcitriol/biossíntese , Calcitriol/sangue , Raquitismo/tratamento farmacológico , Animais , Densidade Óssea/efeitos dos fármacos , Calcitriol/genética , Cálcio/sangue , Colestanotriol 26-Mono-Oxigenase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoporose/tratamento farmacológico , Hormônio Paratireóideo/sangue , Fósforo/sangue , Vitamina D3 24-Hidroxilase/biossíntese , Vitamina D3 24-Hidroxilase/genética
19.
PLoS One ; 13(10): e0203194, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30286109

RESUMO

The level of the vitamin D in the bloodstream is regulated by cytochrome P450 enzyme 24-hydroxylase A1 (CYP24A1). Over expression of CYP24A1 enzyme is correlated with vitamin D deficiency and resistance to vitamin D therapy. Chronic kidney disease (CKD) patients are commonly reported with the above said expression variations. This deregulation could be solved by ligands that act as a vitamin D receptor (VDR) agonists and CYP24A1 antagonists. Posner et al., (2010) first time reported two new vitamin D analogues namely CTA-091 and CTA-018 to inhibit CYP24A1. The CTA-018 inhibited CYP24A1 with an IC50 27 ± 6 nM (10 times more potent than the ketoconazole (253 ± 20 nM)). CTA-018 induced VDR expression (15-fold lower than 1α,25(OH)2D3) and is under phase II clinical trial, whereas CTA-091 was not able to efficiently induce the VDR expression (>2000 nM). To explore the molecular mechanism, binding specificity of these two vitamin D analogues along with native ligand was extensively studied through in silico approaches. Through molecular dynamics simulations studies, we shown that the sulfonic group (O = S = O) in the side chain of CTA-018 plays an important role in the regulation of VDR agonistic activity. The electron lone pairs of the sulfonic group that interacted with His393 lead to be a factor for agonistic mechanism of VDR activity. Compared to azol-based compounds, CTA-018 binds the different sites in the CYP24A1 binding cavity and thus it could be a potent antagonistic for CYP24A1enzyme.


Assuntos
Receptores de Calcitriol/química , Insuficiência Renal Crônica/tratamento farmacológico , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D3 24-Hidroxilase/química , Vitamina D/química , Humanos , Ligação de Hidrogênio , Cetoconazol/administração & dosagem , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Conformação Proteica , Receptores de Calcitriol/agonistas , Receptores de Calcitriol/genética , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/genética , Vitamina D/análogos & derivados , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/genética , Vitamina D3 24-Hidroxilase/antagonistas & inibidores , Vitamina D3 24-Hidroxilase/genética
20.
J Am Soc Nephrol ; 29(10): 2583-2592, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30217807

RESUMO

BACKGROUND: Fibroblast growth factor 23 (FGF23), a bone-derived hormone that regulates phosphorus and vitamin D metabolism, contributes to the pathogenesis of mineral and bone disorders in CKD and is an emerging cardiovascular risk factor. Central elements of FGF23 regulation remain incompletely understood; genetic variation may help explain interindividual differences. METHODS: We performed a meta-analysis of genome-wide association studies of circulating FGF23 concentrations among 16,624 participants of European ancestry from seven cohort studies, excluding participants with eGFR<30 ml/min per 1.73 m2 to focus on FGF23 under normal conditions. We evaluated the association of single-nucleotide polymorphisms (SNPs) with natural log-transformed FGF23 concentration, adjusted for age, sex, study site, and principal components of ancestry. A second model additionally adjusted for BMI and eGFR. RESULTS: We discovered 154 SNPs from five independent regions associated with FGF23 concentration. The SNP with the strongest association, rs17216707 (P=3.0×10-24), lies upstream of CYP24A1, which encodes the primary catabolic enzyme for 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D. Each additional copy of the T allele at this locus is associated with 5% higher FGF23 concentration. Another locus strongly associated with variations in FGF23 concentration is rs11741640, within RGS14 and upstream of SLC34A1 (a gene involved in renal phosphate transport). Additional adjustment for BMI and eGFR did not materially alter the magnitude of these associations. Another top locus (within ABO, the ABO blood group transferase gene) was no longer statistically significant at the genome-wide level. CONCLUSIONS: Common genetic variants located near genes involved in vitamin D metabolism and renal phosphate transport are associated with differences in circulating FGF23 concentrations.


Assuntos
Fatores de Crescimento de Fibroblastos/sangue , Polimorfismo de Nucleotídeo Único , Proteínas RGS/genética , Vitamina D3 24-Hidroxilase/genética , Grupo com Ancestrais do Continente Africano/genética , Estudos de Coortes , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Rim/metabolismo , Masculino , Fosfatos/metabolismo , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIa/genética , Vitamina D/metabolismo
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