Vitamin D Receptor Gene Polymorphisms in Serbian Patients With Bronchial Asthma: A Case-Control Study

Vitamin D receptor and vitamin D binding protein gene polymorphisms in patients with asthma: a pilot study

BACKGROUND

The effects of vitamin D are exerted by interaction with the vitamin D receptor (VDR) and vitamin D binding protein (VDBP). Polymorphisms in VDR or VDBP genes may affect vitamin D levels, influencing the pathogenesis of asthma and atopy. The aim of this study was to investigate the possible association of VDR and VDBP gene single-nucleotide polymorphisms (SNP), 25-hydroxyvitamin D (25(OH)D), blood eosinophils and total IgE level in subjects with asthma in comparison with healthy individuals.

METHODS

This case-control study enrolled 63 subjects with asthma (45 allergic and 18 non-allergic) and 32 healthy subjects were involved in the study. Sensitization of subjects to inhaled allergens was determined by a skin prick test, lung function was evaluated by spirometry. Blood eosinophil count was determined by standard methods. Serum 25(OH)D and total IgE levels were evaluated by ELISA. Polymorphisms in the VDR and VDBP genes on the 12q13.11 and 4q13.3 chromosomal region were analyzed using TaqMan SNP Genotyping Assay probes.

RESULTS

In asthma patients with vitamin D deficiency (< 20 ng/ml) the allele G of rs11168293 of VDR was more common than in those having insufficiency (20-30 ng/ml) of vitamin D (63% and 31%, p < 0.05). Moreover, asthmatic subject with rs11168293 G allele has significant higher blood eosinophil count compared to asthmatic without the rs11168293 G allele (8.5 ± 12.3% vs. 5.1 ± 1.5%, p < 0.05). Significantly higher IgE level was found in subjects with allergic asthma with the allele A of rs7041 on VDBP gene than in those without this allele (540 ± 110 and 240 ± 80 IU/ml, p < 0.05).

CONCLUSIONS

The association of polymorphisms in VDBP and VDR gene, the rs11168293 G allele and the rs7041 A allele, with 25(OH)D, blood eosinophil and total IgE level in asthma, let us suggest that vitamin D, VDR and VDBP gene polymorphisms are important in pathogenesis of asthma despite its form in relation to atopy.

Association between Single Nucleotide Polymorphisms Related to Vitamin D Metabolism and the Risk of Developing Asthma

Asthma is a chronic non-communicable disease that affects all age groups. The main challenge this condition poses is its heterogeneity. The role of vitamin D in asthma has aroused great interest, correlating low vitamin D levels and polymorphisms in the genes involved in its metabolic pathway with the risk of asthma. The aim of this study was to evaluate the influence of 13 single nucleotide polymorphisms (SNPs) related to the vitamin D metabolism on the susceptibility to asthma. An observational case-control study was performed, including 221 patients with asthma and 442 controls of Caucasian origin from southern Spain. The SNPs CYP24A1 (rs6068816, rs4809957), CYP27B1 (rs10877012, rs4646536, rs703842, rs3782130), GC (rs7041), CYP2R1 (rs10741657) and VDR (ApaI, BsmI, FokI, Cdx2, TaqI) were analyzed by real-time PCR, using TaqMan probes. The logistic regression model adjusted for body mass index revealed that in the genotype model, carriers of the Cdx2 rs11568820-AA genotype were associated with a higher risk of developing asthma (p = 0.005; OR = 2.73; 95% CI = 1.36-5.67; AA vs. GG). This association was maintained in the recessive model (p = 0.004). The haplotype analysis revealed an association between the ACTATGG haplotype and higher risk of asthma for the rs1544410, rs7975232, rs731236, rs4646536, rs703842, rs3782130 and rs10877012 genetic polymorphisms (p = 0.039). The other SNPs showed no effect on risk of developing asthma. The Cdx2 polymorphism was significantly associated with the susceptibility of asthma and could substantially act as a predictive biomarker of the disease.

Gene polymorphisms in asthma: a narrative review

Background and Objective

Asthma is a heterogeneous disease caused by interactions between genetic and environmental factors. Genome-wide association studies (GWAS) have revealed that genetic variation plays a crucial role in the occurrence and development of asthma. The objective is to systematically review the existing literature on the association between gene polymorphisms and asthma to better understand the relationship between genetic factors and the occurrence and development of asthma.

Methods

We used keywords "asthma" and "gene polymorphism" with their combinations to search for relevant literature published from 2000 to 2021 in the PubMed database and the foreign medical literature retrieval service (FMRS). All articles included in the review are English. Then, we summarized the information pertaining to the genetic factors related to asthma susceptibility.

Key Content and Findings

This study summarized the information on 10 gene variants related to the risk of asthma published over the past 20 years, which will assist in further understanding the role of genetic variants in the risk of asthma.

Conclusion

Dozens of candidate genes have been identified that were associated with asthma risk. Asthmatics existed specific gene variation performed different response to therapy. Personalized therapy based on genotypic profiling would be an important direction in the future. However, it remains a great challenge for us to explore the relationship between gene polymorphisms and pathophysiological mechanism of asthma.

Association of rs780094 and rs1260326 glucokinase regulatory protein gene polymorphisms with dyslipidemia in a group of Serbian acute ischemic stroke patients

Although genetic variations rs780094 and rs1260326 of the glucokinase regulatory protein gene (GCKR) could be associated with lipid profile imbalance, their influence on acute ischemic stroke (AIS) risk has not yet been established. The aim of this study was to investigate the influence of GCKR single nucleotide polymorphisms (SNPs) rs780094 and rs1260326 on lipid profile parameters in patients with AIS, and to evaluate the association of these SNPs with the risk of AIS. In a casecontrol study, a total of 148 subjects were screened for GCKR rs780094 and rs1260326 SNPs using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The lipid profile was determined based on serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triacylglycerol (TG) concentrations. The frequencies of the minor rs780094T allele and the minor rs1260326T allele were significantly lower in AIS patients compared to controls. The rs780094TT genotype and the rs1260326TT genotype were associated with decreased risk of AIS compared to wildtype carriers. In conclusion, this is the first study implying that decreased risk of AIS in rs780094 and rs1260326 homozygous minor allele carriers is not caused by dyslipidemia, but possibly by the lack of coagulation factor glycosylation.

Association of asthma with low serum vitamin D and its related musculoskeletal and psychological symptoms in adults: a case-control study

There are complex potential inter-relationships between the chronic inflammation of asthma and poor control, vitamin D deficiency, musculoskeletal pain and anxiety and depression. The aim was to investigate associations between vitamin D and these possible co-morbidities. This case-controlled study involved 75 adults with asthma and 75 controls. Serum 25-hydroxyvitamin D (25(OH)D) was measured, levels of anxiety, depression, musculoskeletal pain, and asthma control were assessed. Participants with asthma had lower 25(OH)D and higher anxiety scores and higher measures of musculoskeletal pain compared to controls. Binary logistic regression showed that asthma was associated with decreased 25(OH)D (Odds ratio (OR) = 0.86), general weakness (OR = 13.29), complaint of musculoskeletal pain (OR = 13.73), and increased intensity of musculoskeletal pain (OR = 0.61) and number of painful sites (OR = 2.58). Asthma was not associated with anxiety or depression. Further studies are required to investigate if vitamin D supplementation can improve asthma symptoms and musculoskeletal pain.

Vitamin D Insufficiency is Not Associated With Pediatric and Adolescent Immune Thrombocytopenia: A Study in Conjunction With its Receptor Genetic Polymorphisms

Idiopathic thrombocytopenic purpura (ITP) is a heterogeneous immunologic disorder. Vitamin D has immune-modulatory effects. The pleiotropic effects of vitamin D are exerted via vitamin D receptor (VDR) and its genetic alterations could influence its functions. In our study, we measured the serum 25-hydroxyvitamin D levels in 98 Pediatric and Adolescent ITP patients, in addition to 100 apparently healthy controls. Genetic polymorphisms of the VDR gene FokI, BsmI, ApaI, and TaqI were tested using specific restriction enzymes for each polymorphism. Vitamin D deficiency in the studied Pediatric age was a dominant factor, but it was found not to be associated with Pediatric ITP. However, patients carrying the FokI CC genotype had statistically higher vitamin D levels compared with those carrying other genotypes (P=0.036). Patients who were carriers of the BsmI G allele had a nearly 2-fold higher risk of ITP (odds ratio: 2.203; 95% confidence interval: 1.467-3.309). Therefore, the BsmI polymorphism of VDR could be considered a molecular risk factor for ITP.

Association of vitamin D receptor genetic variants with bone mineral density and inflammatory markers in rheumatoid arthritis

BACKGROUND AND AIMS

Vitamin D receptor (VDR) genetic variants are considered to have a role in the pathogenesis of rheumatoid arthritis (RA). This study examines an association of FokI, BsmI, ApaI and TaqI with RA, as well as with bone mineral density (RA with normal bone mineral density, RA-NBMD; RA with associated osteopenia, RA-OSTP; and RA with associated osteoporosis, RA-OP) and inflammatory markers.

MATERIALS AND METHODS

VDR genetic variants were tested in 248 subjects using the PCR-RFLP method.

RESULTS

Significant differences were observed in the distribution of FokI genotypes between RA patients (p < 0.001), or subgroups (RA-NBMD, RA-OSTP, RA-OP) (p = 0.035, p = 0.02, p < 0.001, respectively) and controls. Prevalence of FokI f allele was significantly higher in RA group (p < 0.001) and subgroups (p = 0.003, p = 0.021, p < 0.001, respectively) compared to controls. An increased susceptibility to RA-OSTP was revealed in BsmI/ApaI Ba (AC) haplotype carriers (p = 0.012). A significantly higher erythrocyte sedimentation rate values were obtained in FokI FF compared to Ff + ff carriers (54.57 ± 23.73 vs. 22.83 ± 12.42; p < 0.001) within the RA-NBMD subgroup.

CONCLUSION

The results of the study indicate an association of RA with FokI genetic variant and increased susceptibility to RA in f allele carriers, as well as to RA-OSTP in BsmI/ApaI Ba (AC) haplotype carriers.

Influence of vitamin D receptor gene FokI and ApaI polymorphisms on glucocorticoid response in patients with asthma

BACKGROUND

Glucocorticoid (GC)-resistant asthma, a complex disease phenotype, has a high morbidity and mortality and takes up a disproportionate share of healthcare costs. The aim of this work was to assess serum 25-hydroxyvitamin D (25(OH)VD) levels in steroid-resistant, steroid-sensitive patients with asthma and in healthy controls, and to investigate the association between the vitamin D receptor gene (VDR) FokI and ApaI polymorphisms and GC resistance in patients with asthma.

METHODS

This case-control study included 70 patients with severe bronchial asthma and 30 apparently healthy controls. Atopic status was determined by skin-prick test reaction to the most common locally-encountered allergens. A GC reversibility test was performed to differentiate between GC-sensitive and GC-resistant asthma. For all subjects, analysis of the VDR FokI and ApaI polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and measurement of serum 25(OH)VD levels by enzyme-linked immunosorbent assay (ELISA) were performed.

RESULTS

The frequencies of FokI polymorphism genotypes and alleles differed significantly between patients with asthma and controls. The frequencies of the TT genotype and T allele carriers were significantly higher among patients with asthma than among controls, and also among GC-resistant patients with asthma than among GC-sensitive patients with asthma. Additionally, serum 25(OH)VD levels differed significantly among the 3 VDR FokI polymorphic genotypes in GC-resistant patients with asthma; the highest level was detected in the TT genotype. No significant differences in ApaI were found.

CONCLUSION

We found a possible association between the FokI T allele and GC resistance in patients with asthma. Variations in VDR FokI might also play a role in 25(OH)VD levels.

VDR Gene Polymorphisms and Allergic Diseases: Evidence from a Meta-analysis

Associations between vitamin D receptor (VDR) gene polymorphisms and allergic diseases were already reported by many publications. The aim of this meta-analysis was to clarify associations between VDR gene polymorphisms and allergic diseases by combing the results of all relevant publications. Eligible publications were searched from Pubmed, Embase, WOS and CNKI. We used Review Manager to combine the results of individual studies. Twenty-one studies were included in this study. Combined results proved that VDR rs1544410 BsmI (over-dominant comparison: p = .04, OR = 1.14, 95% CI 1.01-1.29; allele comparison: p = .03, OR = 1.11, 95% CI 1.01-1.22) and rs731236 TaqI (dominant comparison: p = .01, OR = 1.18, 95% CI 1.04-1.33) polymorphisms were both associated with allergic diseases. In subgroup analyses by type of disease, we confirmed positive results for rs1544410 BsmI polymorphism in both asthma and atopic dermatitis, and for rs731236 TaqI polymorphism in atopic dermatitis. Besides, in subgroup by ethnicity of participants, we observed significant associations with allergic diseases for rs7975232 ApaI polymorphism in Caucasians, for rs1544410 BsmI polymorphism in Asians and Caucasians, and for rs731236 TaqI polymorphism in Asians. We also investigated associations between VDR rs2228570 FokI polymorphism and allergic diseases, yet no any positive results were detected for this polymorphism. If we only focused on asthma, then positive findings were detected for rs1544410 BsmI polymorphism in Caucasians, and for rs731236 TaqI polymorphism in Asians. Collectively, this meta-analysis proved that VDR rs7975232 ApaI, rs1544410 BsmI and rs731236 TaqI gene polymorphisms may confer susceptibility to allergic diseases in certain populations.

Vitamin D receptor gene polymorphism and susceptibility to asthma: Meta-analysis based on 17 case-control studies

BACKGROUND

During the last decade, several studies have evaluated the potential association between vitamin D receptor (VDR) gene polymorphism and susceptibility to asthma. In spite of valuable findings, the results are still contradictory. Therefore, a comprehensive meta-analysis not only solves discrepancies but provides a clue for future projects.

OBJECTIVE

This meta-analysis was performed to identify whether VDR gene polymorphisms (FokI (rs2228570) or TaqI (rs731236) or BsmI (rs1544410) or ApaI (rs7975232)) play a role in the risk of asthma.

METHODS

Electronic search of Web of Science, Scopus, and PubMed databases were systematically conducted from their inception until June 2019, to identify all published studies. Eligibility of the studies was confirmed by precise inclusion and exclusion criteria, and the resultant studies were analyzed.

RESULTS

A total of 17 studies concerning VDR gene polymorphisms and asthma risk were included in this meta-analysis. The results of pooled analysis indicated a statistically significant association between FokI SNP (dominant model [OR = 0.78, 95% CI, 0.62-0.98, random effect model] and allelic model [OR = 0.81, 95% CI, 0.67-0.98, random effect model]) and TaqI SNP (homozygote contract model [OR = 0.70, 95% CI, 0.54-0.89]) with asthma risk. Moreover, subgroup analysis showed that ethnicity influences asthma risk in Asian, African, and American populations. The sensitivity analyses confirmed the stability of the results.

CONCLUSION

This meta-analysis suggests that VDR gene polymorphism is associated with the risk of asthma.

Effects of genetic polymorphisms in Vitamin D metabolic pathway on Vitamin D level and asthma control in South Indian patients with bronchial asthma

Objectives:

The study was designed to evaluate the single-nucleotide polymorphisms (SNPs) of genes involved in Vitamin D actions (rs2228570) and metabolic pathways (rs2248137 and rs10766197) and their associations with serum 25-hydroxy Vitamin D (25(OH)D) level and asthma control in South Indian patients with bronchial asthma.

Materials and Methods:

One hundred and two patients of South Indian origin with bronchial asthma either naive to inhaled corticosteroids (ICSs) or not receiving ICS for ≥1 month were included and were treated with ICS (beclomethasone 200 μg twice daily) for 8 weeks. One hundred and one unrelated healthy South Indians were used as controls. Pulmonary function test and fractional exhaled nitric oxide were used to assess asthma control. Serum 25(OH)D levels (chemiluminescence immunoassay) and SNPs in Vitamin D pathway (real-time polymerase chain reaction) were assessed. The associations of SNPs and serum 25(OH)D with asthma control was determined using linear regression. All analyses were performed using SPSS (version 19) and “SNPStats.” P < 0.05 was considered as statistically significant.

Results:

Vitamin D receptor (VDR) polymorphism (rs2228570) was found to be protective against asthma (P = 0.022), while there were no significant associations between the other two SNPs and asthma. Similarly, poor correlation and insignificant associations between the SNPs and serum 25(OH)D levels were observed in both cases and controls. There were also insignificant associations between the SNPs and asthma control.

Conclusion:

VDR polymorphism (rs2228570) was found to be protective against asthma in South Indians, while other genes involved in the metabolic pathway of Vitamin D did not show associations with asthma.

Vitamin D protects against diabetic nephropathy: Evidence-based effectiveness and mechanism

Vitamin D has been suggested to harbor multiple biological activities, among them the potential of vitamin D in the protection of diabetic nephropathy (DN) has attracted special attention. Both animal studies and clinical trials have documented an inverse correlation between low vitamin D levels and DN risk, and supplementation with vitamin D or its active derivatives has been demonstrated to improve endothelial cell injury, reduce proteinuria, attenuate renal fibrosis, and resultantly retard DN progression. Vitamin D exerts its pharmacological effects primarily via vitamin D receptor, whose activation inhibits the renin-angiotensin system, a key culprit for DN under hyperglycemia. The anti-DN benefit of vitamin D can be enhanced when administrated in combination with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. Mechanistic studies reveal that pathways relevant to inflammation participate in the pathogenesis of DN, however, consumption of vitamin D-related products negatively regulates inflammatory response at multiple levels, indicated by inhibiting macrophage infiltration, nuclear factor-kappa B (NF-κB) activation, and production of such inflammatory mediators as transforming growth factor-β(TGF-β), monocyte chemoattractant protein 1(MCP-1), and regulated upon activation normal T cell expressed and secreted protein(RANTES). The robust anti-inflammatory property of vitamin D-related products allows them with a promising renoprotective therapeutic option for DN. This review summarizes new advances in our understanding of vitamin D-related products in the DN management.

Vitamin D deficiency and vitamin D receptor variants in mothers and their neonates are risk factors for neonatal sepsis

BACKGROUND AND AIM

Increasing prevalence of neonatal sepsis in recent years catch attention to early prevention and management. Vitamin D receptor (VDR) polymorphism can modulate VDR expression level that greatly influences immunity and susceptibility to microbial infections. We aimed to investigate the association of VDR polymorphism at FokI, rs2228570 T/C, and TaqI, rs731236 C/T gene with serum 25-hydroxyvitamin D level and risk of neonatal sepsis.

METHODS

This work carried on 160 subjects classified into 80 cases (40 mothers and their 40 septic neonates) and 80 healthy controls (40 volunteer mothers and their 40 healthy neonates). Genotyping of VDR polymorphisms were assayed by real-time PCR and serum 25-hydroxyvitamin D level and hs-CRP were measured by ELISA.

RESULTS

Vitamin D deficiency was observed in mothers of cases compared with healthy ones (p = <0.001) and in septic neonates versus healthy ones (p = <0.001). Septic neonates had much higher VDR FokI TT genotype (p = 0.014) and T allele (p = 0.003) versus healthy ones. TT genotype and T allele could increase the risk of sepsis with OR 95% CI [4.804 (1.4-16.4)] and [2.786 (1.4-5.7)] respectively while VDR TaqI showed no association with sepsis. There was a strong LD between FokI and TaqI in sepsis cases. In sepsis, T/T genotype at FokI had significantly lower vitamin D (p = <0.001).

CONCLUSION

Vitamin D deficiency in mothers/neonates is a risk factor for neonatal sepsis. VDR FokI T allele had lower 25-hydroxyvitamin D level that may predispose to sepsis hazards.

Vitamin D Receptor TaqI Polymorphism Is Associated With Reduced Follicle Number in Women Utilizing Assisted Reproductive Technologies

PURPOSE

Calcitriol, or 1,25-hydroxycholecalciferol, is the active form of vitamin D. It binds and activates vitamin D receptor (VDR). Infertility and defective folliculogenesis have been observed in female vdr-knockout mice; however, whether VDR polymorphisms affect human ovarian responses to controlled ovarian stimulation (COS) remains unclear. We hypothesized that VDR polymorphisms are associated with infertility and COS responses. Thus, we evaluated the association between the TaqI, BsmI, and FokI VDR polymorphisms and ovarian responses in women undergoing COS.

METHODS

In this study, we recruited a control group (n = 121) comprising volunteers with a history of natural conception and a second group of women undergoing COS (n = 70). TaqI, BsmI, and FokI genotyping was performed via restriction fragment length polymorphism analysis or TaqMan qPCR and Sanger sequencing. Intrafollicular 25(OH)D contents were measured in follicular fluid collected from COS patients during oocyte retrieval. Ovarian response parameters were obtained from patient medical records.

RESULTS

There were no significant differences in the genotype frequencies of VDR polymorphisms (TaqI, BsmI and FokI) between the control and COS groups. However, the allele frequency of TaqI (C allele) was significantly lower in the COS group than in the control group (p = 0.02). Follicle number but not oocyte number was lower in patients with TaqI polymorphic (TC/CC) genotypes (p = 0.03). Importantly, the ratio between the number of follicles retrieved and intrafollicular estradiol concentrations was higher in patients with the TC/CC TaqI genotypes (p < 0.02).

CONCLUSION

We identified an association between the VDR TaqI polymorphism and reduced follicle number in women undergoing COS, suggesting that VDR signaling affects the ovarian response to stimulation via unknown mechanisms.

Association between vitamin D receptor polymorphisms and hepatitis B virus infection susceptibility: A meta-analysis study

BACKGROUND

Hepatitis B virus (HBV) infection is still a serious public health problem. Understanding risk factors associated with development of HBV is greatly important. Numerous studies focus on relationship between vitamin D receptor (VDR) polymorphisms (TaqI, FokI, ApaI, BsmI) and the risk of HBV infection in different ethnic groups. However the results published so far are inconsistent. The aim of this study is to quantify the association between VDR polymorphisms with HBV infection by meta-analysis approach.

METHODS

A systematic search was performed in Pubmed, Embase, China National Knowledge Infrastructure (CNKI), Database of Chinese Scientific and Technical Periodicals (VIP), and WANFANG. All the relevant studies were published up to October 2016.

RESULTS

Finally, 15 published studies included 4218 cases and 2298 controls were included in this meta-analysis. It is interesting to note that FokI FF tends to be a risk factor for HBV infection [FF vs. ff: P<0.01, OR (95%CI)=1.54 (1.19-2.00), I²=0.0%], with no heterogeneity. In addition, genotype Ff and allele F could increase HBV infection risk [Ff vs. ff: P<0.01, OR (95%CI)=1.39 (1.13-1.72); F vs. f: P=0.02, OR (95%CI)=1.23(1.04-1.45)]. However, no associations were found about VDR TaqI, ApaI and BsmI polymorphisms with HBV infection based on each comparison model.

CONCLUSION

This meta-analysis indicates that FokI genotype FF, Ff and allele F increase the risk of HBV infection. All these results support the notion that VDR FokI genotype might has potential role in HBV susceptibility.