Vitamin D Receptor Gene Expression Research Articles

Higher insulin resistance is associated with decreased expression of the vitamin D receptor gene in obese type II diabetic patients with vitamin D deficiency

The Background: The etiology of numerous medical conditions, such as metabolic irregularities, is interconnected with the insufficiency of vitamin D. Furthermore, a theoretical association between the resistance to insulin and the insufficiency of vitamin D has been postulated. This concept is substantiated by empirical evidence obtained through various investigations. The objective of this investigation is to analyze and investigate the significance and influence of vitamin D and the expression of the vitamin D receptor (VDR) gene in the progression of insulin resistance in individuals with T2DM. Methods: The study was carried out 100 type II diabetic patients and 100 healthy controls. Both groups had anthropometry examinations to determine their weights, heights, hip and waist circumferences. Fasting glucose, insulin, insulin resistance (HOMA-IR), and vitamin D levels were all measured. Quantitative real-time PCR was used to analyze the expression of VDR genes in both groups. The folding change was computed using the conventional 2-(∆∆ct) technique. Results: T2DM patients had higher levels of all anthropological measurements, and biochemical parameters compared to controls. Patients had lower levels VDR folding change and vitamin D levels. The diagnostic accuracy of anthropological assessments and biochemical parameters in prediction disease showed significant results. VDR gene expression has a highly significant negative linear association with insulin resistance in obese with vitamin D deficiency patients. Also, negative linear correlation noted between insulin resistance and serum vitamin D levels without significant variation. Conclusion: VDR gene expression and insulin resistance were connected in obese patients T2DM with vitamin D insufficiency..

Pan-Cancer Analysis Confirms the Prognostic and Immunological Implications of the 1,25-Dihydroxy Vitamin D3 Receptor in Cervical Squamous Cell Carcinoma.

Vitamin D receptor (VDR), specifically the 1,25-dihydroxy form, holds significant importance in various types of cancer, including cervical squamous cell carcinoma (CESC), whichposes a significant public health challenge. A pan-cancer analysis was conducted on VDR in CESC, with a focus on its expression and relationship with immune infiltration and genetic alterations. Bioinformatics databases, including TIMER, GEPIA, UALCAN, cBioportal, and Kaplan-Meier Plotter, have been utilized. VDR expression in CESC has been validated using publicly available data. Results were significantly upregulated (P=0.05) in THCA, BRCA, KICH, LUAD, LIHC, STAD, UCEC, CESC, CHOL, ESCA, and HNSC samples. We analyzed the correlation between VDR expression and various clinicopathological factors such as age, race, and cancer stage. VDR expression was significantly upregulated across all age groups, with the highest levels observed in older adults followed by young and middle-aged adults. VDR gene expression was significantly elevated across all races, including Caucasians, African-Americans, and Asians, compared to that in the normal group. Furthermore, VDR expression was significantly upregulated in cancer stages 1, 2, 3, and 4, with the highest increase observed in stage 3 compared to that in normal individuals. We analyzed the expression of the VDRin relation to immune cell type and tumor cell purity in CESC. Our results indicated that VDR expression was positively correlated with neutrophils and dendritic cells and negatively correlated with tumor cell purity in CESC patients. There was no significant correlation between VDR expression and the abundance of B cells, CD8+ T cells, CD4+ T cells, and macrophages. Our study found no significant effect of VDR expression on patient prognosis, although it was positively correlated with CD4+ T cells. The Cox proportional hazards model indicated that age and immune cells did not significantly affect prognosis. Most VDR mutations are concentrated in diffuse large B-cell lymphoma, with an amplification frequency of 4% and a deep deletion frequency of 2.2%. GEO confirmed VDR expression in CESC, identifying 1515 upregulated and 1877 downregulated genes, with volcano plots showing CESC downregulation in patients.

Frequency of rs731236, rs7975232 and rs1544410 single nucleotide polymorphisms of Vitamin-D Receptor (VDR) gene among the Kazakh ethnic group

In the article the pilot study results of the genotypes and individual allele’s frequency of single nucleotide polymorphisms (SNPs) rs731236, rs7975232 and rs1544410 in vitamin D receptor (VDR) gene were presented. The participants were representatives of the Kazakh ethnic group. The SNPs were determined by real-time polymerase chain reaction using the amplification-refractory mutation system (ARMS) technology. The relevance of the study is that rs731236, rs7975232 and rs1544410 contribute to the regulation of VDR gene expression. This affects the synthesis of the VDR protein and its activity as a transcription factor. VDR regulates various metabolic pathways, including the immune response to infectious diseases. In rs731236, the A allele (68.9 %) prevailed over the G (31.1 %). The AA, AG and GG genotypes were 52.1 %, 33.6 % and 14.3 %, respectively. For rs7975232, there were no significant differences in the alleles A and C (42.4 % vs. 57.6 %). There was a predominance of AC and CC genotypes (39.5 % and 37.8 %, respectively), over AA (22.7 %). Allele A of rs1544410 was not found in the Kazakh population. The allele C was 65.6 %, T — 25.6 %, and G — 8.8 %. The frequencies of the CC and CT genotypes were similar (40.3 % vs. 39.5 %). It is possible to study the influence of these SNPs on COVID-19 susceptibility among Kazakhs.

C-reactive protein as a novel biomarker for vitamin D deficiency in alopecia areata.

Alopecia areata (AA) is an autoimmune condition characterized by sudden and unpredictable hair loss, with a lifetime incidence of 2%. AA can be divided into three categories: patchy alopecia, alopecia totalis, and alopecia universalis. It can affect a person's psychological health and overall quality of life. Elevated C-reactive protein (CRP) levels in the liver may indicate an inflammatory response in autoimmune diseases. Vitamin D, essential for immune system control and skin health, may be related to AA. Hair follicles contain vitamin D receptors, which control immunological responses in the skin. However, no study has found a relationship between CRP and vitamin D in AA patients in our region. An analytical cross-sectional study with a case-control design research investigation of 82 AA patients and 81 healthy controls was carried out. Both groups' medical histories were taken. Biochemical analysis was done for both groups as well as the serum vitamin D levels, and CRP. Genetic analysis for CDX2 rs11568820 variant detected by PCR (T-ARMS-PCR) method and vitamin D receptor (VDR) gene expression measured by real-time PCR analysis for both patients and healthy subjects. CRP levels are higher in AA patients, AA patients with G/G genotypes exhibited higher concentrations of CRP when compared to those with A/A and A/G genotypes while patients with A/A genotypes have higher levels of Serum vitamin D as compared to the A/G and G/G genotypes. G allele was more abundant in AA patients. VDR gene expression was lower in AA compared to control and lower in ophiasis compared to localized and multiple patchy AA. An important inverse linear correlation was observed between vitamin D and CRP levels in ophiasis AA. CRP concentrations were found to be elevated in AA patients. The considerable accuracy of CRP in the diagnosis of AA is substantiated by a statistically significant al. A noteworthy inverse linear association was observed between serum vitamin D and CRP concentrations in ophiasis AA.

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.

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. 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. 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. 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. 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.

The association between body mass index elevation and differentiation in vitamin D receptor gene expression, genetic polymorphism, and oxidative stress in adult Egyptian individuals

Vitamin D plays a central role in maintaining calcium, phosphorus, and bone homeostasis in close interaction with the parathyroid hormone. Obesity is a significant health problem worldwide, particularly in developed nations. The current study was carried out to investigate the possible relationship between body mass index (BMI) elevation and differentiation in 25-hydroxyvitamin D (VD), vitamin D receptor (VDR) gene expression, and genetic polymorphism besides oxidative stress in adult Egyptian individuals. This was done to explore the mechanisms underlying the suggested role of the VD/VDR complex in the pathogenesis of obesity. A total of 70 subjects (30 obese, 25 overweight, and 15 normal, age: 20–50 years, without other chronic diseases) were selected. The study focused on the determination of VD, VDR gene polymorphism, VDR gene expression, alkaline phosphatase, calcium, phosphorus, glucose, lipid profile, oxidative stress including, oxidant (malondialdehyde), and anti-oxidants (reduced glutathione and superoxide dismutase). The results showed that elevation in BMI led to the percentage of the Ff 'allele' becoming predominant, while the percentage of the FF 'allele' was in the normal BMI range. Also, BMI elevation caused significant reductions in VD and VDR expression, with significant elevations in alkaline phosphatase and the levels of calcium and phosphate in serum. Also, oxidative stress increases with increasing BMI. Elevation in BMI causes a reduction in VD concentration and VDR gene expression levels. Also, the percentage of heterozygous mutant genotype Ff 'allele' is predominantly in the obese human, in contrast to normal subjects, where the percentage of homozygous wild genotype FF 'allele' is predominant. In general, the genetic expression and polymorphism of VD and VDR can be used as a genetic marker for predisposition, diagnosis, prognosis, and progression of obesity.

B-217 The study of association of FokI Polymorphism of Vitamin D Receptor (VDR) Gene, Vitamin D and Parathyroid Hormone Levels in Stage 4–5 Chronic Kidney Disease Patients: A Cross-sectional Study

Abstract Background Chronic Kidney Disease (CKD) is an important public health problem globally and almost 35% patients of CKD have deficiency in vitamin D which progresses to 80% in stage 4–5 CKD patients. Active vitamin D binds to Vitamin D Receptor (VDR) to regulate target gene transcription. Various genetic variations (Single Nucleotide Polymorphism) such as FokI polymorphism, which is a T/C transition polymorphism (ACG to ATG) may affect the VDR gene expression and thus may play an important role in pathogenesis of CKD. The aim of the study is to study association between FokI Polymorphism of Vitamin D Receptor (VDR) Gene, serum Vitamin D and PTH levels in Stage 4–5 CKD patients. Methods A total of 150 patients, aged 25–60 years, attending the Department of Nephrology AIIMS New Delhi with chronic kidney disease (CKD) stage 4–5, were enrolled for the study. FokI polymorphism was analyzed by using polymerase chain reaction-restriction fragment length Polymorphism (PCR-RFLP) in study subjects. Following DNA isolation and PCR amplification, restriction digestion was done using FokI restriction endonuclease and visualised on 1.5 % agarose gel electrophoresis. The prevalence of different genotypes and allelic frequency distribution was compared between CKD patients and healthy controls (HC). Levels of PTH, Vitamin D were estimated by eCLIA. Results No significant differences in genotype and in allelic frequencies between CKD patients and HC were observed as shown in Table 1. No significant differences in biochemical parameters based on genotypic variations in CKD patients and in HC were observed. Conclusion The present study reveals no association of VDR FokI polymorphism with CKD. Furthermore, no significant differences in biochemical parameters were observed in FF, Ff and ff genotypic subgroups in CKD or HC groups. Further analysis revealed no significant differences in biochemical parameters based on genotypic variations in CKD patients and in HC. Table 1.Genotype frequency and allelic frequency of VDR FOK1 gene polymorphism in CKD patients and HC.Genotype(FOK1)Genotype frequency (%)P-valueX2 (chi2)Allelic frequencyCKD (n = 150)HC (n = 150)Total study group (n = 300)0.7700.5220CKD (n = 150)HC (n = 150)FF53.33 (n = 80)57.33 (n = 86)55.33 (n = 166)FfFfFf41.33 (n = 62)37.33 (n = 56)39.33 (n = 118)0.740.260.760.24ff5.33 (n = 8)5.33 (n = 8)5.33 (n = 16)

VDR, SOD-2, and CYP24A1 Gene Expression in Different Genotypes of BsmI SNP of the Vitamin D Receptor Gene in Individuals with Hypovitaminosis.

Hypovitaminosis D is a public health problem due to its implications for various diseases. Vitamin D has numerous functions, such as modulating the metabolism of cellular tissues, and it is expressed through the vitamin D receptor (VDR) gene that may influence gene expression modulation, which plays an important role in vitamin D metabolism. To evaluate the effect of the genotypes of BsmI single nucleotide polymorphism (SNP) of the VDR gene on VDR, SOD2, and CYP24A1 gene expression in individuals with low serum vitamin D levels. This was a cross-sectional analytical study. After signing the informed consent form, individuals were invited to participate and answered a structured questionnaire with identification data. Blood was collected for biochemical analysis, and vitamin D was measured by chemiluminescence; BsmI polymorphism was determined using real-time polymerase chain reaction (PCR) assays with TaqMan allelic discrimination, and gene expression was conducted by qRT-PCR using QuantiFast SYBR® Green PCR Master Mix. Data were analyzed using the SPSS 20.0 software, and differences were considered significant at p < 0.05. 98 individuals with vitamin D ≤ 20 ng/dL were evaluated, and the BsmI SNP of the VDR gene showed CYP24A1 overexpression and low SOD2 expression. BsmI SNP of the VDR gene can modulate the expression of the genes evaluated without interfering with serum levels.

Evolution of Vitamin D Status and Vitamin D Receptor Gene Expression Among Professional Handball Athletes During a Competitive Period. Relationship with Body Composition, Calcium, Magnesium and Phosphorous.

A generalized risk of vitamin D deficiency exists worldwide affecting also professional and elite athletes. This study assesses the evolution of vitamin D status and vitamin D receptor (VDR) gene expression and their relationship with body composition, calcium (Ca), magnesium (Mg) and phosphorous (P) among professional handball athletes during a competitive period. A total of 26 male subjects were recruited: 13 professional handball athletes and 13 non-athlete controls. An observational follow-up study was conducted in 2 time points over a 16-week period. Nutritional intake, body composition, and routinary biochemical parameters were measured via 24-hours recall, bioimpedance and enzyme immunoassay, respectively. Ca and Mg were measured by flame atomic absorption spectrophotometry and P was determined with the colorimetric method of Fiske-Subbarow. 25-hydroxyvitamin-D (25(OH)D) levels and its forms (i.e., 25(OH)D3 and 25(OH)D2) were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), whereas VDR gene expression was measured by quantitative real time-polymerase chain reaction (qRT-PCR). A total of 54% of the athletes showed deficient vitamin D status. Moreover, a prevalence of insufficient vitamin D status in handball players affected 46% at baseline, reaching 61% after 16 weeks. Vitamin D showed no evolution during the competitive period and no differences between groups were observed (all p ≥ 0.05). Handball players increased the VDR expression, enhanced body composition, Ca and Mg levels at 16-weeks follow-up (all p < 0.05). VDR gene expression was positively related with body mass and body mass index at follow-up in athletes (all p ≤ 0.038; r ≥ 0.579) and with Ca at baseline in controls (p = 0.026; r = 0.648). Finally, 25(OH)D2 form was directly associated with P in athletes at 16 weeks of study (p = 0.034; r = 0.588). Players of indoor team sports such as handball would be a population at risk of vitamin D deficiency. The 16-weeks competition improved VDR gene expression, body composition, Ca and Mg levels. The associations observed between VDR gene expression and the variables of the study evidenced the importance of this receptor as a marker involved in health status in handball athletes despite vitamin D - although in a deficient status -, Ca, Mg and P showed no remarkable changes during the competition period.

Abstract #1406834: Study of Methylation Status and Expression of Vitamin D Receptor Gene in Polycystic Ovarian Syndrome Patients of Kashmiri Population

Downregulation of Vitamin D Receptor (VDR) gene expression resulting from epigenetics events, like methylation in promoter of VDR gene play an important role in pathogenesis, clinical and bio-chemical parameters of polycystic ovary syndrome, but the results from different studies are inconsistent. We aim to determine the methylation status of promoter of VDR gene and VDR gene expression analysis in addition to the co-relation between promoter methylation and expression profile of VDR genes in PCOS patients in Kashmiri Population. This study was a case control, comprising of 100 women with PCOS and 100 normal healthy control women aged between 15-45 years. PCOS patients were selected after proper diagnosis using Rotterdam criteria (2004) and obtaining written consent. DNA extraction was carried out by the non-enzymatic Salting out method and extracted DNA samples were subjected to bisulphite treatment using EZ DNA Methylation-Gold Kit (Zymo Research, Irvine, California) to produces a chemical conversion of unmethylated cytosine to uracil, which is detected as a thymine after PCR. Methylation specific PCR (MS-PCR) was performed following the bisulfite conversion, using pre-designed sets of methylated and unmethylated primers to confirm the prominence of methylation in the promoter VDR region and to specially acknowledge methylated and unmethylated VDR fragments. The VDR expression analysis was carried out following RNA extraction from the blood sample and processed ahead for cDNA synthesis using reverse transcriptase reaction and then relative expression analysis by RT-PCR using SYBR Green fluorescent dye. We found that vitamin D level among test group was significantly lower compared to controls (13.95±9.60 VS. 16.63±7.46; p=0.026). Methylation was significantly higher in test group compared to controls (84% vs 62%; p<0.0001) with OR of 3.21. Furthermore, there exists a significant difference between the average cyclic threshold (CT) value of VDR gene among test and control groups (24.64 vs. 26.14;p <0.0001). The average CT value corresponding to GAPDH (glyceraldehyde phosphate dehydrogenase) is 29.76 in test group and 32.11 in control group. The expression of VDR gene was 0.55 times down regulated in test group in comparison to controls. In the present study, we have comprehensively shown that VDR hypermethylation is significantly associated with reduced vitamin D level and decreased expression level of VDR gene among PCOS women. Increased VDR methylation in response to decreased vitamin D levels could be involved in the impairment of VDR mediated effects resulting in the peculiar clinical and bio-chemical derangements in patients of polycystic ovary syndrome. However, the enhanced ligand availability results in decreased receptor expression to maintain homeostasis of vitamin D signalling. Hence, this, inverse association could have a significant role in the altered gene expression of VDR and thereby effecting the cell response in PCOS patients.

The role of vitamin D receptor and IL-6 in COVID-19.

Vitamin D (Vit.D) has an important role in protecting COVID-19 patients. This study investigated the changes in vitamin D receptor (VDR) expression and interleukin 6 levels in patients with COVID-19. 120 hospitalized patients and 120 healthy people participated in this study, both group adjusted by sex and age. Vit.D was measured with HPLC, the expression of VDR gene was done with Real-time PCR, and IL-6 was measured with ELISA assay. Our findings showed no significant difference in the case of Vit.D (25-OH-D3) between the two studied groups, interestingly the expression of VDR was statistically lower in the patients with COVID-19, p-value=0.003. VDR expression was lower in the patient with diabetes, hypertension and cardiovascular disease, significantly, p-value=0.002. The level of IL-6 was statistically higher in the COVID-19 group, p-value=0.003. Alongside the important role of 25-OH-D3 in COVID-19 patients, the quality and quantity of the VDR expression and its role in the level of IL-6 are the promising risk factors in the future. Further studies are needed to determine the factors increasing the expression level of VDR, especially in the patients with diabetes, hypertension and cardiovascular disease.

Role of the Vitamin D Receptor (VDR) in the Pathogenesis of Osteoporosis: A Genetic, Epigenetic and Molecular Pilot Study.

The vitamin D receptor (VDR) regulates bone development and calcium homeostasis, suggesting a central role in musculoskeletal diseases such as osteoporosis (OP). Several studies have examined the contribution of VDR polymorphisms and epigenetic signatures in bone metabolism and OP risk, with sometimes inconclusive results. Our study aimed to explore the association between genetic variability, expression and the methylation pattern of VDR with the risk of OP in a cohort of Caucasian patients. Genomic DNA from 139 OP, 54 osteopenic (Ope) and 73 healthy (CTR) subjects were used for genotyping the rs731236 (TaqI), rs2228570 (FokI) and rs11568820 (Cdx2) polymorphisms of the VDR gene by an allelic discrimination assay. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis of VDR expression levels and pyrosequencing analysis of a VDR promoter CpG island were carried out in a subcohort (25 OP and 25 CTR) of subjects. Data obtained showed a significantly higher OP risk for rs11568820 G/A and A/A genotypes (p = 0.05). qRT-PCR revealed lower VDR gene expression levels in the OP group compared to CTR subjects (p = 0.0009), also associated with both the rs11568820 A/A genotype (p = 0.03) and femoral fragility fractures (p = 0.05). No association was found between the methylation pattern of the region analyzed of the VDR promoter and its expression levels. Our results identify a significative association between Cdx2 rs11568820 polymorphism and OP risk. In addition, the VDR transcriptomic profile suggests a putative interconnection with OP progression, providing a useful tool to stratify OP phenotype and fragility fracture risk.

Influence of Single-Nucleotide Polymorphisms on Vitamin D Receptor Expression in Periodontal Ligament Fibroblasts as a Response to Orthodontic Compression.

This study aimed to evaluate if single-nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene are associated with gene expression in human periodontal ligament (hPDL) fibroblasts under simulated orthodontic compressive force. hPDL samples from 57 patients were used. A physiological compressive strain was performed to simulate orthodontic tooth movement in pressure areas under cell culture conditions. The RNA from hPDL fibroblasts was isolated to determine the relative gene expression (mRNA) of the VDR. The DNA was also isolated for the genotyping analysis of five SNPs in the VDR gene: BglI (rs739837, G/T), BsmI (rs1544410, T/C), ApaI (rs7975232, A/C), FokI (rs2228570, A/G), and TaqI (rs731236, A/G). Real-time polymerase chain reaction was used for both analyses. Kruskal-Wallis tests were used to compare VDR expression among genotypes of each SNP. A linear regression analysis was performed to evaluate SNP-SNP interaction. An established alpha of 5% was used. The relative mRNA VDR expression according to the genotypes in the SNPs BglI, BsmI, ApaI, FokI, and TaqI was not statistically significantly different (p &gt; 0.05). The SNP-SNP interaction evaluated by regression analysis did not demonstrate any statistically significant association. No association was observed (p &gt; 0.05). In conclusion, the SNPs BglI (rs739837), BsmI (rs1544410), ApaI (rs7975232), FokI (rs2228570), and TaqI (rs731236) did not show an impact on VDR gene expression in hPDL fibroblasts under simulated orthodontic compressive force.

PSUN112 Expression of Vitamin D Receptor Pathway Genes Across Tissues of Individuals with Obesity

Abstract Introduction Vitamin D deficiency is a substantial comorbidity in 50% of pediatric patients and is linked with poorer health outcomes in children. Vitamin D levels are inversely related to BMI. Therefore, the prevalence of children with low vitamin D levels is increasing as the prevalence of pediatric obesity increases. Pediatric patients with obesity and vitamin D deficiency also have a uniquely increased risk of metabolic syndrome, as compared to their lean peers. However, measured levels of vitamin D correlate with other physiological markers of vitamin D effects in lean individuals but not obese individuals. Since vitamin D levels measured as 25-hydroxyvitmain D (serum 25(OH)D) reflect a storage form of vitamin D, their levels may not be a true reflection of vitamin D action in the body in an obese population. The aim of this study was to provide foundational knowledge to understand if expression of vitamin D receptor (VDR)-target genes in different metabolic pathways correlate with each other in diverse tissues, and thus may be used as a reference standard for vitamin D action in the body. Methods We performed a secondary analysis of samples obtained from 89 obese adolescents aged 12 to 18 years old that were consented under a past IRB-approved protocol. The samples were collected at the time of bariatric surgery between 2004 and 2019. Subject data included age, gender, race/ethnicity, and BMI. Samples collected included blood, intestinal, and subcutaneous adipose tissue. The tissues were analyzed via Real Time-PCR to obtain quantitative levels of VDR-target gene expression, which included TLR4, THBD, and VDR in subcutaneous adipose tissue; and TRPV6, S100G, and VDR in intestinal tissue. Gene expression levels were normalized to the average of two housekeeping genes, GAPDH and RPLPO. Blood samples were analyzed for vitamin D levels. Results VDR-target gene expression of THBD, VDR, and TLR4 in subcutaneous adipose tissue was significantly correlated (p &amp;lt;0.05). In intestinal tissue, we also saw significant correlation between TRPV6, S100G, and VDR (p &amp;lt;0.05). THBD, TLR4, TRPV6, S100G, and VDR gene expression levels from the respective tissues did not correlate with circulating serum 25(OH)D levels (p &amp;gt;0.05). Conclusion These important preliminary findings show VDR-target genes have correlated expression patterns within different tissues – one which stores vitamin D (adipose) and one which doesn't (intestinal). Interestingly, the VDR-target gene expression levels correlated with each other despite the genes being involved in different metabolic pathways in diverse tissues. These findings also show that VDR-target gene expression does not correlate with circulating serum 25(OH)D levels. This discrepancy supports that 25(OH)D levels do not indicate levels of vitamin D action and may not be an appropriate indicator of vitamin D deficiency in the obese population. Thus, VDR-target gene expression levels may provide a better reference standard for vitamin D action in the body. This study may provide the first step in determining a new and more accurate biomarker for vitamin D deficiency and treatment in obesity. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Downregulation of the vitamin D receptor expression during acute gastrointestinal graft versus host disease is associated with poor outcome after allogeneic stem cell transplantation.

The vitamin D receptor (VDR) is critical in regulating intestinal homeostasis and emerging evidence demonstrates that VDR deficiency is a critical factor in inflammatory bowel disease pathology. However, no clinical data exist regarding the intestinal expression of VDR in patients after allogeneic haematopoietic stem cell transplantation (HSCT). Analyzing intestinal biopsies from 90 patients undergoing HSCT with mortality follow-up, we demonstrated that patients with severe acute gastrointestinal graft versus host disease (GI-GvHD) showed significant downregulation of VDR gene expression compared to mild or no acute GI-GvHD patients (p = 0.007). Reduced VDR expression was already detectable at acute GI-GvHD onset compared to GvHD-free patients (p = 0.01). These results were confirmed by immunohistochemistry (IHC) where patients with severe acute GI-GvHD showed fewer VDR+ cells (p = 0.03) and a reduced VDR staining score (p = 0.02) as compared to mild or no acute GI-GvHD patients. Accordingly, low VDR gene expression was associated with a higher cumulative incidence of treatment-related mortality (TRM) (p = 1.6x10-6) but not with relapse-related mortality (RRM). A multivariate Cox regression analysis identified low VDR as an independent risk factor for TRM (p = 0.001, hazard ratio 4.14, 95% CI 1.78-9.63). Furthermore, VDR gene expression significantly correlated with anti-microbial peptides (AMPs) gene expression (DEFA5: r = 0.637, p = 7x10-5, DEFA6: r 0 0.546, p = 0.001). In conclusion, our findings suggest an essential role of the VDR in the pathogenesis of gut GvHD and the prognosis of patients undergoing HSCT.

Vitamin D3 deficiency induced intestinal inflammatory response of turbot through nuclear factor-κB/inflammasome pathway, accompanied by the mutually exclusive apoptosis and autophagy.

Vitamin D3 (VD3) participated widely in the nuclear factor-κB (NF-κB)-mediated inflammation, apoptosis, and autophagy through the vitamin D receptor (VDR). However, the molecular mechanisms remain not understood in teleost. The present study investigated the functions of VD3/VDR on intestinal inflammation, autophagy, and apoptosis of turbot in vivo and in vitro. Triple replicates of 30 fish were fed with each of three diets with graded levels of 32.0 (D0), 1012.6 (D1), and 3978.2 (D2) IU/kg VD3. Obvious intestinal enteritis was observed in the D0 group and followed with dysfunction of intestinal mucosal barriers. The intestinal inflammatory response induced by VD3 deficiency was regulated by the NF-κB/inflammasome signalling. The promotion of intestinal apoptosis and suppression of intestinal autophagy were also observed in the D0 group. Similarly, VD3 deficiency in vitro induced more intense inflammation regulated by NF-κB/inflammasome signalling. The mutually exclusive apoptosis and autophagy were also observed in the group without 1,25(OH)2D3 in vitro, accompanied by similar changes in apoptosis and autophagy increased apoptosis. The gene expression of VDRs was significantly increased with the increasing VD3 supplementation both in vivo and in vitro. Moreover, VDR knockdown in turbot resulted in intestinal inflammation, and this process relied on the activation of inflammasome mediated by NF-κB signalling. Simultaneously, intestinal apoptosis was promoted, whereas intestinal autophagy was inhibited. In conclusion, VD3 deficiency could induce intestinal inflammation via activation of the NF-κB/inflammasome pathway, intestinal apoptosis, and autophagy formed a mutually exclusive relation in teleost. And VDR is the critical molecule in those processes.

Overexpressed fibroblast growth factor receptors increase 1,25-dihydroxyvitamin D-dependent differentiation of acute myeloid leukemia cells

Many malignancies are driven by mutations within the gene for fibroblast growth factor receptor 1 (FGFR1). Previously, we have shown that signal transduction from the FOP2–FGFR1 fusion protein in acute myeloid leukemia KG1 cells is responsible for a low level of expression of the vitamin D receptor gene. In this paper, we address whether other fibroblast growth factor receptors regulate the vitamin D receptor (VDR) gene. We used the human myeloid leukemia U937 and HL60 cells, the bone cancer cell line U2OS, and cell transfection methods to answer the question. For myeloid leukemia cells, overexpression of FGFRs 1–3 genes caused a shift towards monocytic differentiation; this was extracellular regulated kinase (Erk) 1,2-dependent. Overexpression of FGFRs 1–3 genes also upregulated expression of the VDR gene, further sensitizing these cells to 1,25-dihydroxyvitamin D-induced monocyte differentiation. When we increased expression in bone cells, fibroblast growth factor receptors did not upregulate VDR gene expression, nor influence the activity of VDR. Fibroblast growth factor receptors are overexpressed in many neoplasms. Therefore, it may be reasonable to use vitamin D analogs to treat these cancers, to activate VDR and drive cell differentiation.

Effect of Vitamin-D-Enriched Edible Mushrooms on Vitamin D Status, Bone Health and Expression of CYP2R1, CYP27B1 and VDR Gene in Wistar Rats.

Vitamin D deficiency is highly prevalent in India and worldwide. Mushrooms are important nutritional foods, and in this context shiitake (Lentinula edodes), button (Agaricus bisporus) and oyster (Pleurotus ostreatus) mushrooms are known for their bioactive properties. The application of ultraviolet (UV) irradiation for the production of substantial amounts of vitamin D2 is well established. Levels of serum 25-hydroxy vitamin D (25-OHD), parathyroid hormone (PTH), calcium, phosphorus and alkaline phosphatase (ALP) were significantly (p < 0.05) improved in vitamin-D-deficient rats after feeding with UVB irradiated mushrooms for 4 weeks. Further, microscopic observations indicate an improvement in the osteoid area and the reduction in trabecular separation of the femur bone. In addition, the level of expression of the vitamin D receptor (VDR) gene and genes metabolizing vitamin D were explored. It was observed that in mushroom-fed and vitamin-D-supplemented groups, there was upregulation of CYP2R1 and VDR, while there was downregulation of CYP27B1 in the liver. Further, CYP2R1 was downregulated, while CYP27B1 and VDR were upregulated in kidney tissue.

Vitamin D Receptor/Vitamin D Response Element Directly Modulate Nestin Transcription to Ameliorate PAN-Induced Podocyte Morphological Changes

Background: The change of podocyte morphology is a pathologic feature of chronic kidney disease. Several studies have suggested that vitamin D plays a role in the protection of podocytes, but the underlying mechanism remains unclear. Methods: The effects of paricalcitol on podocyte injury were tested in a puromycin aminonucleoside (PAN)-induced rat model and cultured mouse podocytes. Proteinuria, podocyte foot process (FP) effacement, and the expression of nestin and vitamin D receptor (VDR) were evaluated. VDR-siRNA or plasmids containing VDR-shRNA were transfected into podocytes to silence VDR expression. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were performed to verify the connection between VDR and nestin gene expression. Results: Paricalcitol significantly alleviated proteinuria and podocyte FP effacement in PAN-induced nephrosis, which was accompanied by increased VDR expression in the glomeruli. Paricalcitol also inhibited PAN-induced nestin overexpression in the glomeruli. In an in vivo study, PAN significantly inhibited VDR protein expression, stimulated nestin protein expression, and resulted in nestin filament derangement in mouse podocytes, while paricalcitol treatment abolished these effects. In contrast, downregulation of VDR resulted in derangement and overexpression of nestin. ChIP assays demonstrated the presence of a vitamin D response element (VDRE) in the nestin promoter, and paricalcitol enhanced the binding of VDR to VDRE. Furthermore, luciferase reporter assays of the nestin promoter fragment showed that paricalcitol effectively repressed nestin reporter gene expression after PAN treatment, and mutation of VDRE abolished this effect. Conclusions: Paricalcitol directly regulates nestin transcription through the interaction of VDR/VDRE, thereby preventing morphological changes of podocytes in PAN nephropathy.

Reduced vitamin D receptor (VDR) and cathelicidin antimicrobial peptide (CAMP) gene expression contribute to the maintenance of inflammatory immune response in leprosy patients

Leprosy is an infectious disease influenced by genetic, immunological, and environmental factors. Reduced gene expressions may be associated with the immunological response pattern and leprosy susceptibility. We investigated the direct and indirect effects of Vitamin D Receptor (VDR) and Cathelicidin Antimicrobial Peptide (CAMP) gene expressions on the serum levels of vitamin D, Cathelicidin, and cytokines in newly-diagnosed leprosy patients and post-six-months of multidrug therapy (MDT). Thirty-four leprosy patients were assessed, paucibacillary (PB; n = 14) and multibacillary (MB; n = 20) cases, untreated or having received six months of MDT, 18 healthy controls, and 25 household contacts. VDR and CAMP gene expression levels were strongly correlated to some important cytokines in both, untreated leprosy patients (PB, r = 0.9319; MB, r = 0.9569) and patients who had undergone MDT (PB, r = 0.9667; MB, r = 0.9569). We observed that both gene expressions directly influenced IL-2, IFN-γ, and IL-17F serum levels in leprosy patients compared to the household contacts and healthy individuals. VDR and CAMP gene expressions induced a persistent inflammatory response in PB and MB leprosy patients, even after six months of MDT, to fight the Mycobacterium leprae infection. Due to the persistent inflammatory profile, multidrug therapy is suggested to be maintained for more than six months, especially for MB patients. Vitamin D supplementation is recommended from the onset as a transcription factor to improve VDR and CAMP gene expression in leprosy patients.