Polymorphism of VDR Gene and the Sensitivity of Human Leukemia and Lymphoma Cells to Active Forms of Vitamin D

The active forms of vitamin D3 (calcitriol and tacalcitol) coupled to the vitamin D receptor (VDR) are known to exhibit anti-cancer properties. However, not all cancer cells are sensitive to the active forms of vitamin D3 and its analogs. The study aimed to determine whether polymorphism of VDR is responsible for the sensitivity of human leukemia and lymphoma cells to calcitriol and tacalcitol. The impact of calcitriol and tacalcitol on the proliferation and morphology of nine different leukemia and lymphoma cell lines was determined. Only MV-4-11, Thp-1, and HL-60 cell lines sensitive to proliferation inhibition by calcitriol and tacalcitol showed morphology changes. Subsequently, the levels of the VDR and 1,25D3-MARRS proteins of calcitriol and tacalcitol binding receptors and the VDR receptor polymorphism in human leukemia and lymphoma cells were ascertained. Contrary to the current understanding, higher levels of VDR are not responsible for the greater sensitivity of cells to calcitriol and tacalcitol. Importantly, we first showed that sensitivity to calcitriol and tacalcitol in leukemias and lymphomas could be determined by the VDR polymorphism. The FokI polymorphism and the presence of the “bat” haplotype were observed only in the sensitive cells.

Vitamin D Receptor Gene Polymorphism and Vitamin D Status in Population of Patients with Cardiovascular Disease—A Preliminary Study

The association between vitamin D receptor (VDR) polymorphism and the risk of cardiovascular diseases (CVD) remains unclear. This study aimed to assess a relationship between the VDR genotypes, plasma concentrations of vitamin D metabolites, and the occurrence of cardiovascular and metabolic disorders. Fifty-eight patients treated for various cardiological afflictions were included. Identification of VDR polymorphisms: ApaI, TaqI, BsmI, and FokI were carried out using the PCR-RFLP method. Plasma concentrations of 25-hydroxyvitamin-D2, 25-hydroxyvitamin-D3, and 3-epi-25-hydroxyvitamin D3 were assessed by the UPLC-MS/MS method. Lower incidence of BsmI AA genotype in the studied patients was observed compared with healthy controls, but the difference was insignificant. Among patients with the TT genotype, frequency of hypertension was higher than among carriers of other ApaI genotypes (p < 0.01). In addition, carriers of the TT ApaI, TC TaqI, and GA BsmI genotypes had an increased risk of obesity, while the presence of the FokI TT genotype was associated with a higher incidence of heart failure and hypertension. In conclusion, the BsmI AA genotype can be protective against CVD, but this observation needs study on a larger group of patients. Particular VDR genotypes were associated with 25-hydroxyvitamin-D levels, and the mechanism of this association should be further investigated.

High-Throughput Gene and Protein Analysis Revealed the Response of Disc Cells to Vitamin D, Depending on the VDR FokI Variants

Vitamin D showed a protective effect on intervertebral disc degeneration (IDD) although conflicting evidence is reported. An explanation could be due to the presence of the FokI functional variant in the vitamin D receptor (VDR), observed as associated with spine pathologies. The present study was aimed at investigating—through high-throughput gene and protein analysis—the response of human disc cells to vitamin D, depending on the VDR FokI variants. The presence of FokI VDR polymorphism was determined in disc cells from patients with discopathy. 1,25(OH)2D3 was administered to the cells with or without interleukin 1 beta (IL-1β). Microarray, protein arrays, and multiplex protein analysis were performed. In both FokI genotypes (FF and Ff), vitamin D upregulated metabolic genes of collagen. In FF cells, the hormone promoted the matrix proteins synthesis and a downregulation of enzymes involved in matrix catabolism, whereas Ff cells behaved oppositely. In FF cells, inflammation seems to hamper the synthetic activity mediated by vitamin D. Angiogenic markers were upregulated in FF cells, along with hypertrophic markers, some of them upregulated also in Ff cells after vitamin D treatment. Higher inflammatory protein modulation after vitamin D treatment was observed in inflammatory condition. These findings would help to clarify the clinical potential of vitamin D supplementation in patients affected by IDD.

Polymorphism of the vitamin D receptor gene in kazakh with bronchial asthma

Introduction. The polymorphism of the vitamin D receptor (VDR) gene is associated with bronchial asthma (BA). Based on this, studies on the prevalence of VDR polymorphism in representatives of different races and peoples with AD and in healthy people are timely.Aims. To determine the TaqI polymorphism of the vitamin D receptor gene (TT, TS and CC) in children and adolescents with a verified diagnosis of AD on the example of the Kazakh population of Western Kazakhstan.Materials and methods. The study involved 54 Kazakh children with BA (Me age 12.8 years, fluctuations range 5–17 years). The control group consisted of residents of the same region without BA: Kazakhs – 66 children, Russians – 40 children. In each of these groups, children were born in the third generation of families without mixed marriages. The examination was performed by collecting venous blood with the informed consent of the legal representative of the child/adolescent. The samples were stored at a temperature of -80 ºC until the start of the analysis with further DNA sequencing and PCR at the INVITRO laboratory.Results. In Kazakh children without BA TT alleles were recorded in 57.6%, TC – in 34.8%, CC – in 7.6%. In Russian children without BA, the TT allele was found in 35.0%, TC – 55.0%, CC – 10%. In children of Kazakhs with BA, the TT allele was in 74.0% of cases, TC in 26.0%, and CC was absent. The first stage of the study with a limited number of observations did not allow obtaining a statistically significant difference between the individual indicated groups. However, taking into account the probable protective effect of the CC allele, the differences in the frequency of the TT alleles and in total TC and CC and CC and in total TT and TC turned out to be significant: 0.000 and 0.030, respectively. When studying the distribution of alleles within the groups, it turned out that for Kazakhs in the control group and, especially, in AD, a decrease in the frequencies of TC alleles and, most clearly, CC alleles is typical.Conclusion. The protective value of the CC allele cannot be ruled out. But it is not yet possible to formulate a final opinion on the functional significance of polymorphism. Further research will help to understand the relationship between the structural features of the VDR and BA.

Study of vitamin D receptor gene polymorphisms in a cohort of myocardial infarction patients with coronary artery disease

Background Vitamin D deficiency is associated with cardiovascular diseases, including coronary artery diseases (CAD). As vitamin D manifests its biological function through its vitamin D receptor (VDR), VDR gene polymorphisms potentially affect VDR functionality and vitamin D activity. Therefore, the objective of this study was to analyze three well-studied VDR gene polymorphisms—Fok1 (rs2228570), BsmI (rs1544410) and Taq1 (rs731236)—in a cohort of CAD patients after acute myocardial infarction. Methods In the presented cross-sectional study, 155 participants with CAD after acute myocardial infarction and 104 participants in a control group without CAD were enrolled. The participants in both groups were Caucasians of European origin. The genotyping of VDR polymorphisms rs2228570, rs1544410 and rs731236 was assessed by RT-PCR. Results The results show an association between the T/T genotype of the BsmI (rs1544410) and the G/G genotype of the Taq1 (rs731236) VDR polymorphism and CAD patients after acute myocardial infarction. There was no association between the Fok1 (rs2228570) VDR polymorphism and CAD patients after acute myocardial infarction. Conclusion The presented results suggest a potential association of the BsmI (rs1544410) and Taq1 (rs731236) VDR polymorphisms with CAD patients after myocardial infarction.

Potential role of vitamin D receptor-related polymorphisms in bronchopulmonary dysplasia

Background The potential contribution of vitamin D and its receptor (VDR) to bronchopulmonary dysplasia (BPD) in preterm neonates is still unknown. The objective of the study was to test the relationship between VDR Taq 1 and Fok 1 gene polymorphisms and BPD in preterm neonates. VDR Fok 1 and Taq 1 gene polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Result No statistically significant differences of genotypic distributions and allele frequencies of Fok 1 and Taq 1 VDR polymorphisms were detected between cases and controls. Moreover, no risk association was detected between both polymorphisms and BPD development in preterm neonates. Homozygous mutant (ff) genotype was the least frequent genotype among BPD and non-BPD groups (2.6%, 13.0% respectively) (p = 0.1). The same was detected for the mutant (CC) genotype frequency in both groups (10.5% and 15.2%, respectively). However, Taq 1 VDR polymorphism was significantly associated with the severity of BPD, as the genotypes with mutant allele C (CC +CT) were more frequent among severe cases (52.2%). Conclusion Fok 1and Taq 1 VDR polymorphisms have no role in BPD development in preterm neonates. However, the presence of a mutant allele of Taq 1 VDR polymorphism may be associated with a more severe form of the disease.

Diverse Effects of Combinations of Maternal-Neonatal VDR Polymorphisms and 25-Hydroxyvitamin D Concentrations on Neonatal Birth Anthropometry: Functional Phenocopy Variability Dependence, Highlights the Need for Targeted Maternal 25-Hydroxyvitamin D Cut-Offs during Pregnancy

Vitamin D receptor (VDR) polymorphisms have been associated with a plethora of adverse pregnancy and offspring outcomes. The aim of this study was to evaluate the combined effect of maternal and neonatal VDR polymorphisms (ApaI, TaqI, BsmI, FokI, Tru9I) and different maternal and neonatal 25(OH)D cut-offs on neonatal birth anthropometry. This cross-sectional study included data and samples from a cohort of mother–child pairs at birth. A detailed neonatal anthropometry analysis at birth was also conducted. Different 25(OH)D cut-offs for neonates and mothers were included, according to their vitamin D status at birth: for neonates, cut-offs of [25(OH)D ≤ 25 and > 25 nmol/L] and [25(OH)D ≤ 50 nmol/L] were adopted, whereas for mothers, a 25(OH)D cut-off of [25(OH)D ≤ 50 and > 50 nmol/L)] was investigated. Following this classification, maternal and neonatal VDR polymorphisms were evaluated to investigate the potential different effects of different neonatal and maternal 25(OH)D cut-offs on neonatal birth anthropometry. A total of 69 maternal-neonatal dyads were included in final analysis. Weight, neck rump length, chest circumference, abdominal circumference, abdominal circumference (iliac), high thigh circumference, middle thigh circumference, lower arm radial circumference, and lower leg calf circumference of neonates who had the TAQl SNP TT genotype and maternal 25(OH)D < 50 nmol/L were significantly higher than that of neonates who had the Tt or tt genotypes (p = 0.001, Hg = 1.341, p = 0.036, Hg = 0.976, p = 0.004, Hg = 1.381, p = 0.001, Hg = 1.554, p = 0.001, Hg = 1.351, p = 0.028, Hg = 0.918, p = 0.008, Hg = 1.090, p = 0.002, Hg = 1.217, and p = 0.020, Hg = 1.263, respectively). Skin fold high anterior was significantly lower in neonates who had the BSMI SNP BB genotype compared to that of neonates with Bb or bb genotypes (p = 0.041, Hg = 0.950), whereas neck rump length was significantly higher in neonates who had the FOKI SNP FF genotype compared to that of neonates who had Ff or ff genotypes (p = 0.042, Hg = 1.228). Regarding neonatal VDR polymorphisms and cut-offs, the abdominal circumference (cm) of neonates who had the TAQI SNP TT genotype and 25(OH)D < 25 nmol/L were significantly higher than that of neonates who had the Tt or tt genotypes (p = 0.038, Hg = 1.138). In conclusion, these results indicate that the maternal TAQI VDR polymorphism significantly affected neonatal birth anthropometry when maternal 25(OH) concentrations were <50 nmol/L, but not for a higher cut-off of >50 nmol/L, whereas this effect is minimally evident in the presence of neonatal TAQI polymorphism with neonatal 25(OH)D values <25 nmol/L. The implication of these findings could be incorporated in daily clinical practice by targeting a maternal 25(OH)D cut-off >50 nmol/L, which could be protective against any effect of genetic VDR variance polymorphism on birth anthropometry.

The association of the Fok1(rs2228570)vitamin D receptor (VDR) polymorphism with cardiovascular diseases predisposition in Sudanese patients.

Cardiovascular diseases (CVDs) are public health concerns globally. The role of genetics in CVDs predisposition was evidenced in previous studies. The nuclear vitamin D receptor (VDR)regulates the transcription of a number of different genes implicated in a variety of diseases including CVDs.In this study we aimed to investigate “for the first time” the association of vitamin D receptor (VDR) FokI(rs2228570)gene polymorphismwith the risk of heart diseases (CVDs) in Sudanese patients. A cross sectional case-control study was conducted, including 60 of proven heart disease (CVD)patients and 77 controls. The demographic information was obtained using well designed questionnaire. The genotypes of the VDR FokIpolymorphism (rs2228570) were determined by polymerase chain reaction-restriction fragment length polymorphism method using Fok1 restriction enzyme.The results of this study showed that atherosclerosis represents 57.1% of the CVD cases. No gender difference was observed when compare cases to the controls (P= 0.13).Previous attack of CVDs was reported in16.7% of the CVD cases. 50% of the patients have family history of CVDs with high significant difference when compared to the controls (P=0.0001)52% and 48% of the CVD patients are hypertensive and diabetic respectively. The genotypes of the Fok1polymorphismof the VDR gene did not differ between CVD patients and control subjects (P=0.72).Thisindicates that this mutation is unlikely to play a major role in CVDs predisposition in our sample. However, the frequencies of the mutant CC and TC genotypes among CVD patients who encountered previous attack was 33.3% and 55.6% respectively.The frequency of the mutant allele among CVD cases and controls is71% and 74% respectively and among who patients have family history of CVD was 72%, indicating a potential presence of the mutant allele in the general population.Thisresult suggest that the Fok1 polymorphism of the VDR gene is unlikely to contribute to CVDs predisposition in this samples, however, a considerable frequency of the mutant allele among CVD cases and controls and among those who have family history of CVDs, indicating a latent presence of the mutant allele in the general population and mightpossibly contribute to disease susceptibility in Sudanese CVD patients.