Association of VDR ApaI and TaqI Gene Polymorphisms with the Risk of Scleroderma and Behçet’s Disease

Serum vitamin D levels and vitamin D receptor gene ApaI and TaqI polymorphisms in patients with morphea: a case-control study

A uncommon inflammatory condition called morphea causes fibrosis in the skin and subcutaneous tissue. The key stages in the pathophysiology are vascular damage, immunological response, and fibrosis. Numerous research have examined the relationships between the immune system, fibrosis, and vitamin D, but the exact pathogenetic pathways of morphea remain poorly understood. The purpose of this study was to investigate serum 25(OH)D levels and the ApaI (rs7975232) and TaqI (rs731236) polymorphisms of the vitamin D receptor (VDR) in morphea patients. There were 48 age- and sex-matched controls and 41 morphea patients total. VDR polymorphisms were found using PCR tests and gel electrophoresis, and serum 25(OH)D levels were determined using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). The patient group consisted of 37 females (90.2%) and 4 males (9.8%). The patients' mean age was 38.68 ± 17.54 years. In terms of VDR ApaI and TaqI polymorphisms, there was no discernible difference between the patient and control groups. TaqI polymorphism heterozygosity was discovered in all patients with progressive disease, and this finding was statistically significant (p = 0.012). Patients' mean serum 25(OH)D levels were 16.98 ± 11.55 ng/mL, while those in the control group were 18.02 ± 14.30 ng/mL. VDR polymorphisms, vitamin D levels, disease subtype, age of onset, and responsiveness to treatment did not significantly correlate. In our research, we discovered that TaqI polymorphism may be related to the severity of the disease and that the polymorphisms of the VDR ApaI and TaqI were not associated with morphea susceptibility.

A review of the critical role of vitamin D axis on the immune system

In recent years, the physiological and molecular functions of vitamin D (Vit-D) have been deeply investigated. At first, Vit-D was considered a regulator of mineral and skeletal homeostasis. However, due to the extensive-expression pattern of Vit-D receptor (VDR) in almost every non-skeletal cell, Vit-D is considered mainly a multifunctional agent with broad effects on various tissues, notably the immune system. The expression of VDR in immune cells such as dendritic cells, monocyte/macrophage, neutrophils, B cells and T cells has been well demonstrated. Besides, such immune cells are capable of metabolizing the active form of Vit-D which means that it can module the immune system in both paracrine and autocrine manners. Vit-D binding protein (DBP), that regulates the levels and homeostasis of Vit-D, is another key molecule capable of modulating the immune system. Recent studies indicate that dysregulation of Vit-D axis, variations in the DBP and VDR genes, and Vit-D levels might be risk factors for the development of autoimmune disease. Here, the current evidence regarding the role of Vit-D axis on the immune system, as well as its role in the development of autoimmune disease will be clarified. Further insight will be given to those studies that investigated the association between single nucleotide polymorphisms of DBP and VDR genes with autoimmune disease susceptibility.

VDR Gene Single Nucleotide Polymorphisms and Autoimmunity: A Narrative Review

The vitamin D/Vitamin D receptor (VDR) axis is crucial for human health as it regulates the expression of genes involved in different functions, including calcium homeostasis, energy metabolism, cell growth and differentiation, and immune responses. In particular, the vitamin D/VDR complex regulates genes of both innate and adaptive immunity. Autoimmune diseases are believed to arise from a genetic predisposition and the presence of triggers such as hormones and environmental factors. Among these, a role for Vitamin D and molecules correlated to its functions has been repeatedly suggested. Four single nucleotide polymorphisms (SNPs) of the VDR gene, ApaI, BsmI, TaqI, and FokI, in particular, have been associated with autoimmune disorders. The presence of particular VDR SNP alleles and genotypes, thus, was observed to modulate the likelihood of developing diverse autoimmune conditions, either increasing or reducing it. In this work, we will review the scientific literature suggesting a role for these different factors in the pathogenesis of autoimmune conditions and summarize evidence indicating a possible VDR SNP involvement in the onset of these diseases. A better understanding of the role of the molecular mechanisms linking Vitamin D/VDR and autoimmunity might be extremely useful in designing novel therapeutic avenues for these disorders.

Vitamin D attenuates elevated oxidative DNA damage in scleroderma patients with organ involvement: A prospective study

Scleroderma is a rare autoimmune disease characterized by progressive fibrosis of the skin and internal organs. Oxidative damage to macromolecules has been reported to occur in scleroderma. Among the macromolecular damages, oxidative DNA damage is a sensitive and cumulative marker of oxidative stress and is of particular interest because of its cytotoxic and mutagenic effects. Vitamin D supplementation is an important part of treatment, as vitamin D deficiency is a common problem in scleroderma. Furthermore, the antioxidant role of vitamin D has been demonstrated in recent studies. In light of this information, the present study aimed to comprehensively investigate oxidative DNA damage in scleroderma at baseline and to evaluate the contribution of vitamin D supplementation to the attenuation of DNA damage in a prospectively designed study. In accordance with these objectives, oxidative DNA damage in scleroderma was evaluated by measurement of stable damage products (8-oxo-dG, S-cdA, and R-cdA) in urine by liquid chromatography-tandem mass spectrometry (LC-MS/MS); serum vitamin D levels were determined by high-resolution mass spectrometry (HR-MS); VDR gene expression and four polymorphisms in the VDR gene (rs2228570, rs1544410, rs7975232, and rs731236) were analyzed by RT-PCR and compared with healthy subjects. In the prospective part, the DNA damage and the VDR expression of the patients who received vitamin D were re-evaluated after the replacement. As a result of this study, we demonstrated that all DNA damage products were increased in scleroderma patients compared to healthy controls, whereas vitamin D levels and VDR expression were significantly lower (p < 0.05). After supplementation, statistical significance (p < 0.05) was reached for the decrease in 8-oxo-dG and the increase in VDR expression. Attenuated 8-oxo-dG after replacement in patients with lung, joint, and gastrointestinal system involvement demonstrated the efficacy of vitamin D in scleroderma patients with organ involvement. To the best of our knowledge, this is the first study to examine oxidative DNA damage in scleroderma comprehensively and to evaluate the effects of vitamin D on DNA damage using a prospective design.

Vitamin D in Systemic Sclerosis: A Review

(1) Background: In the present paper we aimed to review the evidence about the potential implication of vitamin D in the pathogenesis and management of systemic sclerosis (SSc); (2) Methods: we performed a review of the literature looking for studies evaluating the potential role of vitamin D and its analogs in SSc. We searched the PubMed, Medline, Embase, and Cochrane libraries using the following strings: (vitamin D OR cholecalciferol) AND (systemic sclerosis OR scleroderma). We included cohort studies, case-control studies, randomized controlled trials, and observational studies. (3) Results: we identified nine pre-clinical and 21 clinical studies. Pre-clinical data suggest that vitamin D and its analogs may suppress fibrogenesis. Clinical data are concordant in reporting a high prevalence of hypovitaminosis D and osteoporosis in SSc patients; data about the association with clinical manifestations and phenotypes of SSc are, conversely, far less consistent; (4) Conclusions: in vitro data suggest that vitamin D may play an antifibrotic role in SSc, but clinical data confirming this finding are currently lacking. Hypovitaminosis D is common among SSc patients and should be treated to reduce the risk of osteoporosis.

5Apal, Taql, Fokl, and Bsml polymorphisms and the susceptibility of Behcet's disease: an updated meta-analysis

OBJECTIVE

The aim of this study was to investigate whether the gene polymorphisms of vitamin D receptor (VDR) had a genetic effect on the susceptibility of Behcet's disease (BD).

MATERIAL AND METHODS

We conducted a meta-analysis emphasizing the association between the VDR gene polymorphisms and the risk of BD. The strength of the association in five genetic models was assessed by pooled odds ratios (OR) with a corresponding 95%confidence interval (CI).

RESULTS

A total of seven independent comparisons with 478 cases and 666 healthy controls were included in this meta-analysis. The overall results suggested that a significant association between ApaI polymorphism and BD risk was found in allele comparison, recessive model, and homozygote model among total populations. Subgroup analysis indicated that a significant association of ApaI polymorphism in the development of BD existed under the allelic model among Africans, while for Caucasians, a similar link was identified in the recessive model and homozygote model. Regarding Bsml polymorphism, an obvious relationship was detected to be significant in allele comparison and recessive model in the Caucasian population. Interestingly, the Fokl variant decreased the risk of BD in Africans under five genetic models, while it increased the risk in Caucasians across the recessive model and homozygote model.

CONCLUSION

The results of this meta-analysis provide evidence of the link between the four widely studied polymorphisms in the VDR gene and BD, indicating a robust estimate of the genetic risk.

Dualities of the vitamin D in systemic sclerosis: a systematic literature review

BACKGROUND

Systemic sclerosis (SSc) is a chronic disease characterized by autoimmunity, vasculopathy, and visceral and cutaneous fibrosis. Vitamin D has several functions in the immunological system, and different studies have suggested a potential role in triggering autoimmune diseases. Patients with SSc may present with low serum levels of vitamin D, but the association between hypovitaminosis D and disease onset or any clinical manifestation is still obscure. Our goal was to verify the causal relationship between hypovitaminosis D and SSc onset or any particular clinical manifestation in the literature.

METHODS

A systematic literature review was performed through February 24th, 2021 on Pubmed, Lilacs/BIREME, and Cochrane databases. The eligible studies were read in full text, and, in the absence of exclusion criteria, were included in this review after consensus between two reviewers.

RESULTS

Forty articles met the eligibility criteria and the main results of each study are described. In most studies, SSc patients showed a higher prevalence of vitamin D deficiency and insufficiency compared to controls. Additionally, in some reports serum levels of vitamin D were inversely correlated with the severity of SSc. Oral supplementation did not seem to affect serum levels of vitamin D. Four of the included studies were with experimental models.

CONCLUSION

In conclusion, vitamin D deficiency seems to have a role in susceptibility to SSc, as well as in the clinical manifestations of the disease.

Role of miR-146a rs2910164 and UTS2 rs228648 Genetic Variants in Behçet's Disease

Background: Behçet's disease (BD) is a chronic autoimmune inflammatory disease. Clinical studies revealed that both microRNAs and urotensin II (UTS2) play a significant role in the development of autoinflammatory diseases.Purpose: The study aimed to determine the association between miR-146a rs2910164 and UTS2 rs228648 genetic variants and BD susceptibility. In addition, the relationship between these gene variants and clinical and laboratory outcomes among Egyptian patients was investigated.Methods: The distributions of miR-146a rs2910164 and UTS2 rs228648 (p.Thr21Met) variants were analyzed in 94 patients with BD and 115 healthy control subjects using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Taqman Real-time PCR techniques.Results: Frequencies of the G/G genotype and G allele of miR-146a rs2910164 variant were significantly higher in patients with BD compared with normal controls (p = .042, OR = 2.31; p = .022, OR = 1.58, respectively). The frequencies of the Thr/Thr genotype and the Thr allele of UTS2 rs228648 variant were significantly higher in subjects with BD compared with normal controls (p = .028, OR = 3.35; p = .032, OR = 1.60, respectively).Conclusion: Our results suggest that miR-146a rs2910164 and UTS2 rs228648 variants have significant roles in both the development and clinical modulation of BD in Egyptian patients.

Associations of Vitamin D Receptor Single Nucleotide Polymorphisms with Susceptibility to Systemic Sclerosis

BACKGROUND

This study aims to evaluate whether the Vitamin D receptor (VDR) gene polymorphisms were associated with systemic sclerosis (SSc) in a Chinese Han population.

METHODS

Using a hospital-based case-control study including 100 SSc patients and 100 healthy controls. Single nucleotide polymorphisms (SNPs) in the VDR region were genotyped by the improved multiplex ligase detection reaction (i MLDR) method. Haplotypes were also constructed after linkage disequilibrium (LD) analysis.

RESULTS

Eight SNPs (rs731236 (TaqI), rs2228570 (FokI), rs7975232 (ApaI), rs1544410 (BsmI), rs11574010 (Cdx2), rs739837 (BglI), rs757343 (Tru9I) and rs11168267) were included. There were significant differences between SSc patients and healthy individuals in ApaI and BglI genotype (both adjusted p = 0.008). Through the genotyping, significantly association of SSc were found for: dominant model of ApaI and BglI (both OR (95% CI) = 1.80 (1.03,3.16), p = 0.040). Furthermore, the elevation of erythrocyte sedimentation rate (ESR) had a higher percentage of BglI GT genotype frequency (p = 0.034) and dominant model of ApaI (p = 0.016) in SSc. There was high linkage disequilibrium was detected in BglI and ApaI polymorphisms (r² = 1.0, D' = 1.0), Tru9I and rs11168267 (r² = 0.926, D' = 0.969), respectively. No significant difference were found in these four haplotypes (all p >0.05). The correlation between VD levels and VDR gene polymorphisms was not statistically significant.

CONCLUSIONS

Our preliminary study indicates the ApaI and BglI genotype may possibly have a role in the pathogenesis of SSc patients. Dominant model of ApaI and BglI GT genotype frequency may be associated with the increased risk of ESR.

High Vitamin D Levels May Downregulate Inflammation in Patients with Behçet's Disease

Vitamin D plays a significant role in the immune system modulation and may confer a protective role in autoimmune diseases. We conducted a case-control study to compare 25(OH)D levels in patients with BD who were managed at a regional rheumatology programme in the midwest region of Ireland compared to matched controls. Healthy controls were selected from the Irish health system and matched in 1 : 5 ratio for age, sex, and the month of the year. 25(OH)D levels <20 nmol/L were classified as deficient while levels between 20 and 40 nmol/L were classified as insufficient. Differences between groups were assessed using Mann-Whitney test and associations between cases and controls were expressed as odds ratios and 95% confidence intervals. Nineteen patients with BD were compared with 95 controls matched by age, sex, and month of blood draw. 25(OH)D levels were significantly higher in patients in BD than in matched controls (median values: 45 nmol/L versus 22 nmol/L, p < 0.005) and tended to be lower in patients with active disease than in those without (median values: 35 nmol/L (IQR: 22.75-47.25 nm/L) versus 50 nmol/L (IQR: 35-67 nmol/L), p = 0.11). Compared to controls, patients with BD were significantly less likely to have 25(OH)D deficiency or insufficiency (OR: 0.09, 95% CI: 0.03-0.28, p < 0.001). Our findings suggest a possible role for 25(OH)D in modifying the inflammatory response in BD and uncover a potential opportunity to assess whether correction of Vit D deficiency confers protective benefits.