BMP6 and VDR gene polymorphisms are associated with osteonecrosis in a sickle cell anaemia cohort.

The occurrence and severity of osteonecrosis in sickle cell anaemia (SCA) vary due to risk factors, including genetic modifiers. Bone morphogenetic proteins (BMPs), particularly BMP6, and the vitamin D receptor (VDR) play key roles in cartilage and bone metabolism, making them potential contributors to orthopaedic outcomes in SCA. Here, we evaluated the association of polymorphisms in BMP6 (rs3812163, rs270393 and rs449853) and VDR (FokI rs2228570 and Cdx2 rs11568820) genes with osteonecrosis risk in a Brazilian SCA cohort. A total of 177 unrelated SCA patients were selected. The AA genotype of BMP6 rs3812163 was independently associated with a lower osteonecrosis risk (p = 0.015; odds ratio (OR): 0.38; 95% confidence interval (CI): 0.18-0.83) and with the long-term cumulative incidence of osteonecrosis (p = 0.029; hazard ratio: 0.56, 95% CI: 0.34-0.94). The VDR rs2228570 TT genotype was independently associated with a lower osteonecrosis risk (p = 0.039; OR: 0.14; 95% CI: 0.02-0.90). In summary, our results provide evidence that BMP6 rs3812163 and the VDR rs2228570 might be implicated in osteonecrosis pathophysiology in SCA and might help identify individuals at high risk.

Potential interplay between tumor size and vitamin D receptor (VDR) polymorphisms in breast cancer prognosis: a prospective cohort study.

PURPOSE: Vitamin D has some anticancer properties that may decrease breast cancer risk and improve prognosis. The aim was to investigate associations between four previously studied VDR SNPs (Taq1, Tru91, Bsm1, and Fok1) and prognosis in different groups of breast cancer patients. METHODS: VDR genotyping of 1,017 breast cancer patients included 2002-2012 in Lund, Sweden, was performed using Oncoarray. Follow-up was until June 30, 2019. Clinical data and patient information were collected from medical records and questionnaires. Cox regression was used for survival analyses. RESULTS: Genotype frequencies were as follows: Fok1 (AA 15.7%, AG 49.1%, GG 35.1%), Bsm1 (CC 37.2%, CT 46.1%, TT 16.7%), Tru91 (CC 77.8%, CT 20.7%, TT 1.5%), and Taq1 (AA 37.2%, AG 46.2%, GG 16.6%). During follow-up there were 195 breast cancer events. The homozygous variants of Taq1 and Bsm1 were associated with reduced risk of breast cancer events (adjusted HR = 0.59, 95% CI 0.38-0.92 for Taq1 and adjusted HR = 0.61, 95% CI 0.40-0.94 for Bsm1). The G allele of the Fok1 was associated with increased risk of breast cancer events in small tumors (pT1, adjusted HR = 1.83, 95% CI 1.04-3.23) but not in large tumors (pT2/3/4, adjusted HR = 0.80, 95% CI 0.41-1.59) with a borderline interaction (Pinteraction = 0.058). No interactions between VDR genotypes and adjuvant treatments regarding breast cancer prognosis were detected. CONCLUSION: VDR genotypes were associated with breast cancer prognosis and the association might be modified by tumor size. Further research is needed to confirm the findings and elucidate their potential clinical implications.

Effects of evocalcet on parathyroid calcium-sensing receptor and vitamin D receptor expression in uremic rats.

Little is known about the effect of the recently developed calcimimetic evocalcet (Evo) on parathyroid calcium-sensing receptor (CaSR) and vitamin D receptor (VDR) expression. We examined the effects of Evo and cinacalcet (Cina) on CaSR and VDR expression in 5/6 nephrectomized Sprague-Dawley rats fed a high-phosphorus diet for 4 weeks to develop secondary hyperparathyroidism (SHPT). These uremic rats were divided into 4 groups-baseline control (Nx4W) and groups with additional treatment with either the Vehicle, Evo, or Cina for 2 weeks; normal rats were used as normal controls (NC). Blood parameters and parathyroid tissue were analyzed. CaSR and VDR expression levels were determined using immunohistochemistry. The degree of kidney injury and hyperphosphatemia was similar in the uremic groups (Nx4W, Vehicle, Cina, and Evo). Serum parathyroid hormone levels were significantly higher in the Nx4W and Vehicle groups than in the NC group. This increase was significantly suppressed in the Cina and Evo groups compared with that in the Vehicle group. Serum calcium levels were significantly and equally lower in the Cina and Evo groups relative to those in the Vehicle group. CaSR expression was significantly lower in the Nx4W and Vehicle groups than in the NC group. This downregulation was of an equally lesser magnitude in the Cina and Evo groups. A similar trend was observed for VDR expression. These results indicate that Evo and Cina treatment can increase parathyroid CaSR and VDR expression in uremic rats with SHPT, which could provide better control of mineral and bone disorder markers.

Vitamin D-vitamin D receptor alleviates oxidative stress in ischemic acute kidney injury via upregulating glutathione peroxidase 3.

Vitamin D receptor was previously reported to be protective in acute kidney injury (AKI) with the mechanism unclear, while the role of renal localized glutathione peroxidase 3 (GPX3) was not illustrated. The present study aims to investigate the role of GPX3 as well as its correlation with vitamin D-vitamin D receptor (VD-VDR) in ischemia-reperfusion (I/R)-induced renal oxidative stress injury. We showed that the expression of GPX3 and VDR were consistently decreased in renal tissues of I/R-related AKI patients and mice models. VDR agonist paricalcitol could reverse GPX3 expression and inhibit oxidative stress in I/R mice or hypoxia-reoxygenation (H/R) insulted HK-2 cells. VDR deficiency resulted in aggregated oxidative stress and severer renal injury accompanied by further decreased renal GPX3, while tubular-specific VDR overexpression remarkably reduced I/R-induced renal injury with recovered GPX3 in mice. Neither serum selenium nor selenoprotein P was affected by paricalcitol administration nor Vdr modification in vivo. In addition, inhibiting GPX3 abrogated the protective effects of VD-VDR in HK-2 cells, while GPX3 overexpression remarkably attenuated H/R-induced oxidative stress and apoptosis. Mechanistic probing revealed the GPX3 as a VDR transcriptional target. Our present work revealed that loss of renal GPX3 may be a hallmark that promotes renal oxidative stress injury and VD-VDR could protect against I/R-induced renal injury via inhibition of oxidative stress partly by trans-regulating GPX3. In addition, maintenance of renal GPX3 could be a therapeutic strategy for ischemic AKI.

VDR promotes pancreatic cancer progression in vivo by activating CCL20-mediated M2 polarization of tumor associated macrophage.

BACKGROUND: Activation of VDR pathway was a promising anti-tumor therapy strategy. However, numerous clinical studies have demonstrated the effect of activating VDR is limited, which indicates that VDR plays a complex role in vivos. METHODS: We analyzed the TCGA database to examine the association between VDR expression and immune cell infiltration in pancreatic adenocarcinoma (PAAD). Western blot, ELISA, ChIP, and dual-luciferase reporter assays were performed to determine the mechanism of VDR regulating CCL20. Migration assay and immunofluorescence were used to investigate the role of CCL20 in M2 macrophage polarization and recruitment. We employed multiplexed immunohistochemical staining and mouse models to validate the correlation of VDR on macrophages infiltration in PAAD. Flow cytometry analysis of M2/M1 ratio in subcutaneous graft tumors. RESULTS: VDR is extensively expressed in PAAD, and patients with elevated VDR levels exhibited a significantly reduced overall survival. VDR expression in PAAD tissues was associated with increased M2 macrophages infiltration. PAAD cells overexpressing VDR promote macrophages polarization towards M2 phenotype and recruitment in vitro and vivo. Mechanistically, VDR binds to the CCL20 promoter and up-regulates its transcription. The effects of polarization and recruitment on macrophages can be rescued by blocking CCL20. Finally, the relationship between VDR and M2 macrophages infiltration was evaluated using clinical cohort and subcutaneous graft tumors. A positive correlation was demonstrated between VDR/CCL20/CD163 in PAAD tissues and mouse models. CONCLUSION: High expression of VDR in PAAD promotes M2 macrophage polarization and recruitment through the secretion of CCL20, which activates tumor progression. This finding suggests that the combination of anti-macrophage therapy may improve the efficacy of VDR activation therapy in PAAD.

Exposure to Progestin 17-OHPC Induces Gastrointestinal Dysfunction through Claudin-1 Suppression in Female Mice with Increased Anxiety-Like Behaviors.

INTRODUCTION: Progestin, commonly used in oral contraception and preventing preterm birth, elicits various off-target side effects on brain and gastrointestinal (GI) functions, yet the precise mechanisms remain elusive. This study aims to probe progestin's impact on GI function and anxiety-like behaviors in female mice. METHODS: Colon stem cells were utilized to explore the mechanism underlying progestin 17-hydroxyprogesterone caproate (17-OHPC)-mediated suppression of claudin-1 (CLDN1), crucial for epithelial integrity. Chromatin immunoprecipitation and luciferase assays identified potential progestin-response elements on the CLDN1 promoter, with subsequent assessment of oxidative stress and pro-inflammatory cytokine release. Manipulation of vitamin D receptor (VDR) or estrogen receptor ß (ERß) expression elucidated their roles in 17-OHPC-mediated effects. Intestine-specific VDR deficient mice were generated to evaluate 17-OHPC's impact on GI dysfunction and anxiety-like behaviors in female mice. Additionally, gene expression was analyzed in various brain regions, including the amygdala, hypothalamus, and hippocampus. RESULTS: Exposure to 17-OHPC suppressed CLDN1 expression via epigenetic modifications and VDR dissociation from the CLDN1 promoter. Furthermore, 17-OHPC intensified oxidative stress and pro-inflammatory cytokine release. VDR knockdown partly mimicked, while overexpression of either VDR or ERß partly restored 17-OHPC-mediated effects. Intestinal VDR deficiency partly mirrored 17-OHPC-induced GI dysfunction, with minimal impact on 17-OHPC-mediated anxiety-like behaviors. CONCLUSIONS: 17-OHPC suppresses CLDN1 expression through VDR, contributing to GI dysfunction in female mice, distinct from 17-OHPC-induced anxiety-like behaviors. This study reveals a new mechanism and potential negative impact of progestin exposure on the GI tract, alongside inducing anxiety-like behaviors in female mice.

Delving the vitamin D receptor variation and expression profiles in the context of type 2 diabetes among families.

BACKGROUND: Vitamin D is essential for insulin secretion and sensitivity. Consequently, its inadequacy is linked to higher insulin resistance and Type 2 Diabetes (T2D). The Vitamin D receptor (VDR) gene is one potential candidate for T2D, and multiple polymorphisms in VDR have been examined in various populations, but no conclusive answers have been provided. OBJECTIVES: This study was designed to evaluate the susceptibility of VDR gene polymorphism and its expression in diabetic families in Pakistan. METHODOLOGY: In this family-based study, twenty diabetic families with a positive family history of T2D and at least three T2D patients were recruited from outpatient clinics and public hospitals. The current study comprised 143 individuals with 55 affected and 88 unaffected individuals. Blood samples of the selected families were collected. DNA was extracted from the collected samples and the PCR-RFLP method was followed to identify the genotyping and RT-qPCR for expression. Phenotypic and genotypic pedigrees of the families were developed by the progeny online tool. The association values of SNPs were determined by TDT and DFAM analysis implemented on Plink software. RESULTS: The results explained a significant familial aggregation among phenotypic characters including Age, Gender, BMI (body mass index), age of disease diagnosis, disease duration, and blood pressure in the probands, affected FDRs (First Degree Relatives) and affected SDRs (Second Degree Relatives). A significant association of rs731236 C/T (OR = 1.522), rs2228570 C/T (OR = 1.327) with p < 0.05. Whereas, for rs1544410 G/A (OR = 0.9706) and rs7975232 T/G (OR = 0.7368) no considerable association evidence was seen (p > 0.05) in families. The mRNA expression of VDR increased threefold (p = 0.0204) in patients compared to controls. Variation-based expression analysis exhibited that the rs2228570 genotype influences the expression. CONCLUSION: A linkage was found among the FDRs with probands. Variation in the gene VDR at loci rs731236 and rs2228570 was associated with familial T2D. However further research is required to explore more genetic factors that could influence T2D risks in families.

Is vitamin D receptor (VDR) polymorphism associated with head and neck cancer risk? A systematic review and meta-analysis.

BACKGROUND: Head and neck cancer encompasses neoplasms affecting the oral cavity, pharynx, larynx, and thyroid. Identifying factors that modulate the carcinogenesis process can aid in identifying subgroups at higher risk of developing the disease, enabling implementation of prevention programs. Vitamin D receptor polymorphisms can affect the carcinogenesis of various tumors by altering vitamin D metabolism and cellular response. METHODS: To elucidate the role of vitamin D receptor polymorphisms in head and neck cancer, a systematic review was performed, searching the Embase, PubMed, Scopus, and Lilacs databases. A total of 19 articles met the inclusion criteria. The frequency of vitamin D receptors polymorphism alleles (FokI, ApaI, BsmI, TaqI, Cdx2, rs2107301, rs2238135) was recorded and pooled to calculate the odds ratio in a meta-analysis using the Review Manager software. RESULTS: Subgroup analysis demonstrated significant associations in the anatomical site of cancer (oral cancer in ApaI and BsmI, and unspecified subsites of head and neck cancer in TaqI), genotyping method (FokI and BsmI), and continent of the study (ApaI, FokI, and BsmI). CONCLUSION: Our findings were heterogeneous, as with other evidence available in the literature. Therefore, more clinical studies with larger sample sizes are needed to obtain more accurate results on the relationship between vitamin D receptor polymorphism and head and neck cancer.

Correlation of vitamin D receptor genotypes, specific IgE levels and other variables with asthma control in children.

INTRODUCTION: Asthma is a common condition affecting millions of children globally. The main goal of this study is to assess factors related to asthma management, particularly atopy level and the impact of genetic variants of the vitamin D receptor (VDR) gene. METHODS: Asthmatic children were enrolled in an outpatient respiratory clinic. Information on patients' medication adherence, medical and medication factors, and sociodemographic were gathered. Spirometry FEV1% and FVC% measurements, and the asthma control test were used to evaluate the severity of asthma, and genotyping of the VDR gene and radioallergosorbent test (RAST) were conducted. Regression analyses were conducted to evaluate variables associated with asthma control and spirometry measures. RESULTS: A total of 313 participants (67.4% males) were recruited in the current study. The mean age was 9.37 (±3.45) years. The mean score for adherence was 4.26 (±2.52), and only 46% of the participants had controlled asthma. Forward conditional stepwise binary regression showed that low and moderate Inhaled corticosteroids (ICS) dose (OR= 0.42 (95% CI 0.20-0.90), p = 0.026; OR = 0.371 (95% CI 0.2-0.72), p = 0.003, respectively) decreased the odds of being in the controlled asthma group, while higher inhaler score (OR = 2.75 (95% CI 2.17-3.49, p < 0.001)) increased the odds of being in the controlled asthma group. However, results found no association between VDR genotype and asthma control, spirometry values or hospitalization due to asthma. CONCLUSIONS: The results indicated that many of the asthma patients had poorly controlled asthma. Factors that were associated with poor asthma control included poor inhaler technique.

Effect of regulated vitamin D increase on vascular markers in patients with chronic kidney disease: A systematic review and meta-analysis of randomized controlled trials.

AIM: The effect of increased vitamin D levels on vascular function in patients with chronic kidney disease (CKD) is controversial. This meta-analysis aimed to assess the effect of regulated vitamin D increase on vascular markers in patients with CKD. DATA SYNTHESIS: We searched PubMed, Web of Science, Embase and ClinicalTrials.gov from database inception up until July 21, 2023. We included randomized controlled trials assessing the effects of using vitamin D and its analogues on vascular function in patients with CKD. Fixed-effects and random-effects model analyses were performed using weighted mean difference effects for each trial by heterogeneity (I2) assessment. Primary outcomes encompassed blood flow-mediated dilation (FMD)、pulse wave velocity (PWV) and augmentation index (AIx). FINDINGS: From 1964 records we selected 12 trials, 5 (n = 331) on FMD, 8 (n = 626) on PWV and 4 (n = 393) on AIx. Vitamin D and VDRA supplementation failed to significantly improve FMD (WMD 1.68%; 95% CI -0.18 to 3.53; P = 0.08; I2 = 88%)、PWV (WMD -0.41 m/s; 95%CI -0.95 to 0.13; P = 0.14; I2 = 57%)and AIx (WMD -0.53%; 95%CI -1.69 to 0.63; P = 0.37; I2 = 0%). Subgroup analysis revealed that 2 µg paricalcitol significantly improved FMD (WMD 2.09%; 95%CI 1.28 to 2.90; P < 0.00001); I2 = 0%), as did cholecalciferol (WMD 5.49%; 95% CI 4.35 to 6.63; P < 0.00001). CONCLUSION: Supplementation vitamin D and VDRA are associated with improved vascular function as measured by FMD, but not arterial stiffness as measured by PWV and AIx, tentatively suggesting that regulating the increase of vitamin D could not potentially reduce the incidence of cardiovascular disease.

Association of vitamin D receptor genetic polymorphisms with the risk of infertility: a systematic review and meta-analysis.

BACKGROUND: The causes of infertility have remained an important challenge. The relationship between VDR gene polymorphisms and infertility has been reported, with controversial findings. OBJECTIVE AND RATIONALE: We aimed to determine this relationship by conducting a systematic review and meta-analysis. SEARCH METHODS: The study was started with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration and the final draft was registered as a protocol in PROSPERO (ID: CRD42023416535). The international electronic databases including PubMed (Medline), Scopus, Web of Sciences, and Cumulative Index to Nursing and Allied Health Literature (CINHAL) were searched until January 30, 2023, by using appropriate keywords. The quality of the final studies was assessed using the NOS Checklist for case-control studies. The odds ratios (ORs) for each of the genetic models were pooled, and a subgroup analysis based on geographical region and types of infertility was carried out by the MetaGenyo online tool. OUTCOMES: Case-control studies including 18 and 2 studies about infertility in women and men, respectively, and 4 miscarriage studies were entered into the meta-analysis. The VDR gene TaqI polymorphism was associated with infertility susceptibility in women in the allele contrast [OR = 1.2065, 95% CI (1.0846-1.3421); P = 0.0005], Recessive model [OR = 1.3836, 95% CI (1.1197-1.7096); P = 0.002], Dominant model [OR = 1.2146, 95% CI (0.0484-1.4072); P = 0.009], Homozygote [OR = 1.4596, 95% CI (1.1627-1.8325); P = 0.001], and TT vs. Tt [OR = 1.2853, 95% CI (1.0249-1.6117); P = 0.029. ApaI and FokI gene polymorphisms were found to be significantly protective SNPs against women and men infertility in the Dominant model [OR = 0.8379, 95% CI (0.7039- 0.9975); P = 0.046] and Recessive model [OR = 0.421, 95% CI (0.1821-0.9767); P = 0.043], respectively. Sub-group meta-analysis showed a protection association of ApaI in dominant [OR = 0.7738, 95% CI = 0.6249-0.9580; P = 0.018] and AA vs. aa [OR = 0.7404, 95 CI% (0.5860-0.9353) P = 0.011725] models in PCOS subgroup, however, a negative association with idiopathic infertility was found in AA vs. Aa [OR = 1.7063, 95% CI (1.1039-2.6375); P = 0.016187] and Aa vs. aa [OR = 0.6069, 95% CI (0.3761-0.9792); P = 0.040754]. TaqI SNP was significantly associated with infertility in the African population and BsmI was associated with the disease mostly in the Asian population. CONCLUSION: This meta-analysis showed that the TaqI polymorphism may be linked to women's infertility susceptibility. However, ApaI and FokI might be the protective SNPs against infertility in Women and men, respectively.

Vitamin D receptor gene polymorphisms role in COVID-19 severity: Results of a Mexican patients' cohort.

Vitamin D status has been involved with coronavirus disease 19 (COVID-19) severity. This may be mediated by vitamin D metabolism regulatory genes. Of interest is the vitamin D receptor (VDR) gene, which has been previously associated with other inflammatory and respiratory diseases. In order to investigate the role of VDR gene polymorphisms in COVID-19 severity and outcome, a total of 292 COVID-19 patients were classified according to severity in moderate (n = 56), severe (n = 89) and critical (n = 147) and, according to outcome in survivor (n = 163) and deceased (n = 129), and analysed for FokI and TaqI VDR gene polymorphisms by polymerase chain reaction-based restriction enzyme digestion. The FokI and TaqI single nucleotide polymorphisms (SNPs) were not associated with COVID-19 severity or mortality individually but when analysed by haplotype, TC was associated with an increased risk of presenting critical COVID-19. Additionally, FokI CT genotype was more frequent in COVID-19 patients with hypertension, and T allele carriers presented higher aspartate aminotransferase levels. Our results suggest a relationship between VDR FokI and TaqI SNPs and COVID-19 severity in Mexican population. Although there are some previous reports of VDR polymorphisms in COVID-19, this represents the first report in Latin American population. Further studies on other populations are encouraged.

Molecular investigation of vitamin D receptor (VDR) genetic variants and their impact on VDR mRNA and serum vitamin D levels in allergic rhinitis in an Indian population: A case-control study.

Vitamin D deficiency is widespread and poses a significant health concern, as emerging research links it to allergic diseases owing to its immunomodulatory functions. The optimal functioning of vitamin D and its activation depend on its nuclear receptor, vitamin D receptor (VDR). Genetic variants of VDR have been explored as potential factors in autoimmune and allergic diseases, with limited studies on their association with allergic rhinitis (AR). The present investigation aims to analyse the role of three VDR genetic variants - TaqI, FokI and BsmI - in AR susceptibility and their impact on VDR mRNA and serum vitamin D levels. A total of 550 subjects, consisting of 250 AR cases and 300 age- and gender-matched controls, underwent genotyping by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). VDR mRNA and vitamin D levels were determined by quantitative real-time PCR and chemiluminescence, respectively. Although TaqI did not exhibit significant differences, FokI demonstrated a noteworthy association with AR, particularly with the CC genotype (odds ratio [OR]: 3.34; confidence interval [CI]: 1.79-6.23). Similarly, BsmI revealed an increased risk for AR, with the GA + AA genotypes showing a 2.2-fold elevated risk (OR: 2.20; CI: 1.53-3.16). VDR mRNA expression was threefold lower in AR patients (p < .0001), accompanied by reduced serum vitamin D levels (p < .0001). In addition, CC (p = .01) and AA (p = .02) genotypes of FokI and BsmI were associated with reduced VDR mRNA levels, whereas TaqI showed no such association. Similarly, heterozygous genotypes of TaqI and FokI, as well as homozygous AA of BsmI, correlated with lower serum vitamin D levels (p < .001). This study emphasizes the intricate relationship among VDR genetic variations, altered VDR activity, immune modulation and vitamin D metabolism in AR. Further research involving diverse populations is crucial for confirming and generalizing these findings, paving the way for personalized therapeutic interventions in vitamin D-related disorders.

The effect of BsmI (rs1544410) single nucleotide polymorphism of vitamin D receptor (VDR) on insulin resistance in healthy children and adolescents: a cross-sectional study.

The increasing prevalence of metabolic syndrome, type 2 diabetes, and insulin resistance are driven by complex interactions between genetic and environmental factors. One of the single nucleotide polymorphisms (SNPs) in the VDR gene associated with vitamin D levels is the rs1544410 SNP. This study examined the association of the rs1544410 polymorphism with insulin resistance to predict and screen for possible association with type 2 diabetes and target these individuals for appropriate treatment. This cross-sectional study examined 270 children and adolescents aged 9 to 18 years. Anthropometric and biochemical parameters were determined. Insulin resistance/sensitivity was determined using Quicki, HOMA-IR, MacAuley, Revised MacAuley, Bennetts, FIRI and insulin-to-glucose ratio. The BsmI single nucleotide polymorphism (rs1544410) was determined using the PCR-RFLP method after extracting DNA from peripheral blood collected from fasted subjects, and the resulting data were analyzed using SPSS software and statistical tests.According to linear regression analysis, a significant difference was found in Insulin to glucose ratio, FIRI and HOMA-IR indices between Bb / bb and BB genotypes and it was observed that individuals with BB genotype polymorphism of BsmI vitamin D receptor gene, after Adjustment of age, sex, BMI are at greater risk for insulin resistance and type 2 diabetes.This study demonstrated that those with the BB genotype of VDR BsmI polymorphism were at higher risk for insulin resistance and developing type 2 DM.

Vitamin D3 improves iminodipropionitrile-induced tic-like behavior in rats through regulation of GDNF/c-Ret signaling activity.

Children with chronic tic disorders (CTD), including Tourette syndrome (TS), have significantly reduced serum 25-hydroxyvitamin D [25(OH)D]. While vitamin D3 supplementation (VDS) may reduce tic symptoms in these children, its mechanism is unclear. The study aim was to investigate the effects and mechanisms of vitamin D deficiency (VDD) and VDS on TS model behavior. Forty 5-week-old male Sprague-Dawley rats were randomly divided into (n = 10 each): control, TS model, TS model with VDD (TS + VDD), or TS model with VDS (TS + VDS; two intramuscular injections of 20,000 IU/200 g) groups. The VDD model was diet-induced (0 IU vitamin D/kg); the TS model was iminodipropionitrile (IDPN)-induced. All groups were tested for behavior, serum and striatal 25(OH)D and dopamine (DA), mRNA expressions of vitamin D receptor (VDR), glial cell line-derived neurotrophic factor (GDNF), protooncogene tyrosine-protein kinase receptor Ret (c-Ret), and DA D1 (DRD1) and D2 (DRD2) receptor genes in the striatum. TS + VDD had higher behavior activity scores throughout, and higher total behavior score at day 21 compared with TS model. In contrast, day 21 TS + VDS stereotyped behavior scores and total scores were lower than TS model. The serum 25(OH)D in TS + VDD was < 20 ng/mL, and lower than control. Striatal DA of TS was lower than control. Compared with TS model, striatal DA of TS + VDD was lower, while in TS + VDS it was higher than TS model. Furthermore, mRNA expression of VDR, GDNF, and c-Ret genes decreased in TS model, and GDNF expression decreased more in TS + VDD, while TS + VDS had higher GDNF and c-Ret expressions. VDD aggravates, and VDS ameliorates tic-like behavior in an IDPN-induced model. VDS may upregulate GDNF/c-Ret signaling activity through VDR, reversing the striatal DA decrease and alleviating tic-like behavior.

Hypermethylation and down-regulation of vitamin D receptor (VDR) as contributing factors for polycystic ovary syndrome (PCOS): a case-control study from Kashmir, North India.

BACKGROUND: Polycystic ovarian syndrome (PCOS) is a prevailing endocrinopathy affecting a significant population of women of reproductive age across the globe. A myriad set of complex intertwined factors ranging from etiological, genetic, and epigenetic reasons cause this disorder. Out of the different factors, vitamin D shows an imperative aspect in health and fertility of women with polycystic ovary syndrome (PCOS). The importance of vitamin D is facilitated by vitamin D receptor (VDR), a ligand-dependent transcription factor in the steroid/ thyroid hormone receptor superfamily that controls the pleiotropic biological properties of vitamin D. PURPOSE: The purpose of this study was to evaluate the role of promoter methylation of the VDR gene, a transcription factor with numerous biological utilities, with its relative expression and clinico-pathological findings and outcomes. METHODOLOGY: A total of 200 blood samples were collected, 100 from PCOS case subjects, and 100 from the normal healthy controls respectively, which were assessed by qRT-PCR for determining the expression summary. MS-PCR technique was used for analyzing the promoter methylation status of the VDR gene. Blood samples were withdrawn, respectively, for each case and the control study separately experimented for different stages for the given study, of which estimation of vitamin D was also a part. RESULTS: In this test-versus-control study, first, the promoter methylation status of VDR gene was identified which was found more prominent i.e., hyper-methylation of the VDR gene was identified in 84 cases (84%), and in the normal healthy controls, it was found (62%). The promoter methylation status of the VDR gene has remarkably shown the results with a significant difference (p value < 0.0001*). Second, the expression analysis of VDR gene was found to be strongly downregulated in majority (64%) of PCOS case samples analyzed by means fold change of 0.8743 (± 0.06466) (p value 0.0054**). This result is, therefore, indicative of VDR gene role in PCOS pathogenesis as the said gene is downregulated. Moreover, compared to the vitamin D parameter, hyper-methylation and expression analysis of the VDR promoter gene were found to correspond to some associations with PCOS. Certain case-and-control study analyses showed that patients with normal vitamin D levels showed less indicative effects of PCOS and vice versa. CONCLUSION: Our study, being exclusive from Kashmir, one of the foremost specified that VDR confirms anomalous methylation configuration in PCOS with subsequent downregulation in the gene expression i.e., there is an inverse correlation among VDR gene expression (downregulated) and methylation status (hyper-methylated) from the conclusion of our PCOS case-versus-control study.

Vitamin D in atherosclerosis and cardiovascular events.

Both experimental and clinical findings linking vitamin D to cardiovascular (CV) risk have prompted consideration of its supplementation to improve overall health. Yet several meta-analyses do not provide support for the clinical effectiveness of this strategy. Meanwhile, the understanding of the roles of vitamin D in the pathophysiology of CV diseases has evolved. Specifically, recent work has revealed some non-classical pleiotropic effects of vitamin D, increasing the complexity of vitamin D signalling. Within particular microenvironments (e.g. dysfunctional adipose tissue and atherosclerotic plaque), vitamin D can act locally at cellular level through intracrine/autocrine/paracrine feedforward and feedback circuits. Within atherosclerotic tissues, 'local' vitamin D levels may influence relevant systemic consequences independently of its circulating pool. Moreover, vitamin D links closely to other signalling pathways of CV relevance including those driving cellular senescence, ageing, and age-related diseases-among them CV conditions. This review updates knowledge on vitamin D biology aiming to clarify the widening gap between experimental and clinical evidence. It highlights the potential reverse causation confounding correlation between vitamin D status and CV health, and the need to consider novel pathophysiological concepts in the design of future clinical trials that explore the effects of vitamin D on atherosclerosis and risk of CV events.

Paricalcitol Has a Potent Anti-Inflammatory Effect in Rat Endothelial Denudation-Induced Intimal Hyperplasia.

Neointimal hyperplasia is the main cause of vascular graft failure in the medium term. Vitamin D receptor activation modulates the biology of vascular smooth muscle cells and has been reported to protect from neointimal hyperplasia following endothelial injury. However, the molecular mechanisms are poorly understood. We have now explored the impact of the selective vitamin D receptor activator, paricalcitol, on neointimal hyperplasia, following guidewire-induced endothelial cell injury in rats, and we have assessed the impact of paricalcitol or vehicle on the expression of key cell stress factors. Guidewire-induced endothelial cell injury caused neointimal hyperplasia and luminal stenosis and upregulated the expression of the growth factor growth/differentiation factor-15 (GDF-15), the cytokine receptor CD74, NFκB-inducing kinase (NIK, an upstream regulator of the proinflammatory transcription factor NFκB) and the chemokine monocyte chemoattractant protein-1 (MCP-1/CCL2). Immunohistochemistry confirmed the increased expression of the cellular proteins CD74 and NIK. Paricalcitol (administered in doses of 750 ng/kg of body weight, every other day) had a non-significant impact on neointimal hyperplasia and luminal stenosis. However, it significantly decreased GDF-15, CD74, NIK and MCP-1/CCL2 mRNA expression, which in paricalcitol-injured arteries remained within the levels found in control vehicle sham arteries. In conclusion, paricalcitol had a dramatic effect, suppressing the stress response to guidewire-induced endothelial cell injury, despite a limited impact on neointimal hyperplasia and luminal stenosis. This observation identifies novel molecular targets of paricalcitol in the vascular system, whose differential expression cannot be justified as a consequence of improved tissue injury.

Exploring the Role of Vitamin D, Vitamin D-Dependent Proteins, and Vitamin D Receptor Gene Variation in Lung Cancer Risk.

Lung cancer has an unfavorable prognosis with a rate of low overall survival, caused by the difficulty of diagnosis in the early stages and resistance to therapy. In recent years, there have been new therapies that use specific molecular targets and are effective in increasing the survival chances of advanced cancer. Therefore, it is necessary to find more specific biomarkers that can identify early changes in carcinogenesis and allow the earliest possible treatment. Vitamin D (VD) plays an important role in immunity and carcinogenesis. Furthermore, the vitamin D receptor (VDR) regulates the expression of various genes involved in the physiological functions of the human organism. The genes encoding the VDR are extremely polymorphic and vary greatly between human populations. To date, there are significant associations between VDR polymorphism and several types of cancer, but the data on the involvement of VDR polymorphism in lung cancer are still conflicting. Therefore, in this review, our aim was to investigate the relationship between VDR single-nucleotide polymorphisms in humans and the degree of risk for developing lung cancer. The studies showcased different gene polymorphisms to be associated with an increased risk of lung cancer: TaqI, ApaI, BsmI, FokI, and Cdx2. In addition, there is a strong positive correlation between VD deficiency and lung cancer development. Still, due to a lack of awareness, the assessment of VD status and VDR polymorphism is rarely considered for the prediction of lung cancer evolution and their clinical applicability, despite the fact that studies have shown the highest risk for lung cancer given by TaqI gene polymorphisms and that VDR polymorphisms are associated with more aggressive cancer evolution.

Ablation of Vitamin D Signaling in Cardiomyocytes Leads to Functional Impairment and Stimulation of Pro-Inflammatory and Pro-Fibrotic Gene Regulatory Networks in a Left Ventricular Hypertrophy Model in Mice.

The association between vitamin D deficiency and cardiovascular disease remains a controversial issue. This study aimed to further elucidate the role of vitamin D signaling in the development of left ventricular (LV) hypertrophy and dysfunction. To ablate the vitamin D receptor (VDR) specifically in cardiomyocytes, VDRfl/fl mice were crossed with Mlcv2-Cre mice. To induce LV hypertrophy experimentally by increasing cardiac afterload, transverse aortic constriction (TAC) was employed. Sham or TAC surgery was performed in 4-month-old, male, wild-type, VDRfl/fl, Mlcv2-Cre, and cardiomyocyte-specific VDR knockout (VDRCM-KO) mice. As expected, TAC induced profound LV hypertrophy and dysfunction, evidenced by echocardiography, aortic and cardiac catheterization, cardiac histology, and LV expression profiling 4 weeks post-surgery. Sham-operated mice showed no differences between genotypes. However, TAC VDRCM-KO mice, while having comparable cardiomyocyte size and LV fibrosis to TAC VDRfl/fl controls, exhibited reduced fractional shortening and ejection fraction as measured by echocardiography. Spatial transcriptomics of heart cryosections revealed more pronounced pro-inflammatory and pro-fibrotic gene regulatory networks in the stressed cardiac tissue niches of TAC VDRCM-KO compared to VDRfl/fl mice. Hence, our study supports the notion that vitamin D signaling in cardiomyocytes plays a protective role in the stressed heart.