Vitamin D Receptor Research Articles

Evaluation relationship between VDR gene and clinical and inflammatory factors in patients with RRMS.

Adipocyte levels including leptin and FABS-4 levels, adiponectin, obesity, and vitamin D can be related to the occurrence and exacerbation of MS disease. This research aimed at determining the relationship between VDR gene changes and clinical and inflammatory factors in patients with relapsing-remitting multiple sclerosis (RRMS). This case/control study was conducted based on the ethical principles of Helsinki. RRMS disease was confirmed based on history, clinical signs, radiological signs, and neurologist's diagnosis. The research population consisted of healthy people and patients with RRMS referring to Hazrat Rasool Akram Hospital between 2021 and 2023 who met the criteria for entering the research. FokI polymorphism is associated with a substantial increase in risk, with an odds ratio of 7.28, for those with the FF genotype who have RRMS compared to healthy individuals (OR=7.28: 95% CI; 1.86, 28.41). The presence of FokI polymorphism significantly raises the likelihood of developing RRMS in persons with the FF genotype compared to healthy individuals, with an odds ratio of 28.7. RRMS patients with genotypes did not exhibit a significant increase in risk compared to controls for FokI, ApaI, TaqI, and BsmI polymorphisms. None of the studied polymorphisms revealed a significant risk in obese patients with different genotypes compared to the obese people. Further research, including more cases, is needed to avoid results that could be inflated by small samples or low frequencies of minor alleles.

A study of the association of vitamin D receptor (VDR) as a predictive biomarker for immune checkpoint inhibitor therapy with immune invasion in colon adenocarcinoma

Colon adenocarcinoma(COAD) is a primary and aggressive malignancy with the fifth highest mortality rate among cancers, and it is important to discover new strategies. The online database was used to analyze the correlation between Vitamin D receptor (VDR) and COAD, and further explore the immune infiltration and related gene networks.The expression and methylation levels of VDR was analyzed by using Timer database, GEPIA platform and UALCAN database. GeneMANIA database was used to analyze and obtain gene networks that are closely linked to VDR. UALCAN database was used to score the gene effects of VDR in colorectal cancer cell lines. The cBioPortal database was used for the detection of gene mutations. The survival curve analysis was carried out using the GEPIA database. The relationship between VDR expression and immune cell infiltration was analyzed by using the timer database and TISIDB database. TISIDB database was used to obtain VDR-related drug targets.The expression of VDR was significantly lower in COAD(p<0.05). The methylation level of VDR was significantly higher in COAD (p<0.05). The gene mutation rate of VDR in COAD was 2 %. OS and DFS were not associated with changes in the VDR gene in patients with COAD. VDR expression was correlated with CD4+T cell infiltration, macrophage infiltration, neutrophil infiltration, and dendritic cell infiltration. VDR has a clear correlation with ADORA2A, BTLA, CD160, CD244, CD274, CD96, CSF1R, CTLA4, HAVCR2, IL10, IDO1, LAG3, LGALS9, PDCD1, PDCD1LG2, PVRL2, TGFB1, TGFBR1, TIGIT and VTCN1.The expression of VDR is associated with immune infiltration in patients with COAD. VDR may be a new candidate biomarker for determining the level of immune infiltration and predicting immune checkpoint inhibitor therapy.

8236 Hepatocyte Vitamin D Receptor (VDR) Regulates Liver Regeneration

Abstract Disclosure: J.E. Gunton: None. Harendran Elangovan [1], Rebecca A. Stokes [1], Jeremy Keane [1], Sarinder Chahal [1], Caroline Samer [1], Miguel Agoncillo [1], Josephine Yu [1], Jennifer Chen [1], Michael Downes 2, Ronald M. Evans 2, Christopher Liddle [1],2, Jenny E. Gunton [1] [1]Centre for Diabetes, Obesity and Endocrinology, The Westmead Institute for Medical Research, University of Sydney, Westmead, NSW, Australia 2 Salk Institute for Biological Studies, La Jolla, CA. USA Background: Vitamin D signals through the vitamin D receptor (VDR) to induce its end-organ effects. Hepatic stellate cells control development of liver fibrosis in response to stressors and vitamin D signaling decreases fibrogenesis. VDR expression in hepatocytes, however, is low in healthy liver, and the role of VDR in hepatocyte proliferation is unclear. Methods: In these studies, hepatocyte-VDR null mice (hVDR) were used to assess the role of VDR and vitamin D signaling in hepatic regeneration. Mice underwent 2/3 partial hepatectomy and liver regeneration and function were studied. Results: hVDR mice had impaired liver regeneration with impaired hepatocyte proliferation. This was associated with significant differential changes in bile salts. Notably, mice lacking hepatocyte VDR had significant increases in expression of conjugated bile acids after partial hepatectomy, consistent with failure to normalize hepatic function by the 14-day time point tested. CDCA (chenodeoxycholate) is an FXR ligand, which was increased after surgery in controls but not in hVDR mice. FXR signaling is important for hepatocyte proliferation. Real-time PCR of hVDR and control livers showed significant changes in expression of cell cycle genes including cyclins D1 and E1 and cyclin-dependent kinase 2. Gene expression profiling of hepatocytes treated with vitamin D or control showed regulation of groups of genes involved in liver proliferation, hepatitis, liver hyperplasia / hyperproliferation and liver necrosis / cell death. Conclusions: Together these studies demonstrate an important functional role for VDR in hepatocytes during liver regeneration. Combined with the known profibrotic effects of impaired VDR signaling in stellate cells, these studies provide a mechanism whereby vitamin D deficiency would both reduce hepatocyte proliferation and permit fibrosis, leading to significant liver compromise. Presentation: 6/2/2024

7954 Vitamin D Deficiency Underlies Defective Endometrial Decidualization In Vivo and In Vitro

Abstract Disclosure: M. Yi: None. T. Wang: None. A. Jukic: None. F.J. DeMayo: None. Several epidemiologic studies have reported associations between vitamin D and both menstrual cycles and fertility. Vitamin D signaling occurs most often through the interaction of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) with its cognate receptor, the transcription factor vitamin D receptor (VDR). This study aims to define the role of vitamin D and VDR on female reproduction and identify vitamin D-mediated signaling. In our studies, preliminary results demonstrate mice on a vitamin D-deficient diet showed a significantly impaired uterine decidualization reaction in response to exogenous hormones. To knockdown VDR expression, human endometrial stroma cells (THESCs) were transfected with either non-targeting control (siNT) or VDR siRNA (siVDR) for 48 h. And, to perform the in vitro decidualization, the cell culture media was replaced to differentiate the cells by treatment with 17β-estradiol (E), medroxyprogesterone acetate (P), and db-cAMP (C) for 72 h. At the 48 h exposure of EPC, the decidual media was replaced with containing 1,25(OH)2D3 or vehicle and cultured for 24 h additionally. Treatment of 1,25(OH)2D3 (ligand) and knockdown of VDR (receptor) in THESCs resulted in an increased expression of the decidualization markers, PRL and IGFBP1. Transcriptomic analysis was then conducted to identify the biological networks regulated by the ligand and receptor in THESCs. THESCs were transfected with either siNT or siVDR for 48 h, and the culture media was replaced with either treatment of 2 nM of 1,25(OH)2D3 or vehicle for an additional 24 h. Differentially expressed genes (DEGs) were affected by the ligand and receptor (N = 626 and 1499, respectively) based on a three-way ANOVA filtered with false discovery rate (FDR)-adjusted p-value&amp;lt;0.05 and fold-change (FC)≥|1.4|. Pathway analyses and predicted upstream regulators were analyzed by Ingenuity Pathways Analysis (IPA), and among the predicted upstream regulators of the DEGs, β-estradiol was predicted as an activator for both. Thus, to test the role of vitamin D in estrogen signaling, THESCs were treated with either EPC or PC for 72 h in total, and at the 48 h exposure, the decidual media was replaced with 1,25(OH)2D3 or vehicle and cultured for 24 h additionally. Removal of estrogen (PC) caused loss of the enhanced expression of decidual markers by 1,25(OH)2D3 that was observed in control EPC-treated cells. In conclusion, Vitamin D signaling modulates human and mouse uterine stromal cell differentiation by modulating the ability of estrogen to stimulate decidualization in endometrial stromal cells, a process critical to establishing pregnancy. Presentation: 6/2/2024

6874 A Rare Case Of Hereditary 1,25 (OH)2D Resistant Rickets

Abstract Disclosure: G. Umarji: None. F. Thelmo: None. S.A. Jabbour: None. Vitamin D-dependent rickets type 2A (VDDR2A) also known as hereditary 1,25 (OH)2D resistant rickets is due to biallelic loss-of-function mutations in the gene encoding vitamin D receptor on chromosome 12q13.11, thus, it represents a true form of tissue resistance to vitamin D. It is a scarce form of rickets with approximately only 120 cases reported. A 37-year-old male was referred to endocrinology by neurosurgery for evaluation of metabolic bone disease. Seven years ago, he was in a car accident which resulted in a lumbar spine injury causing radiculopathy and severe low back pain leading to lumbar spine decompression/fusion. However, he suffered from nonunion of bones and had to undergo another surgery a year later with recurrent postoperative nonunion of bones. During the operation, the surgeon noticed that his spine seemed demineralized. He had a history of multiple minor fractures in childhood, decreased hearing in left ear for two years, fragile teeth for many years, and some hair loss since age 30. Physical exam showed a height of 1.82 m, weight 89.3 kg with body mass index of 26 kg/m2, broken teeth, no leg bowing and normal stance. Laboratory results showed normal renal function, thyroid function tests and testosterone level, corrected calcium 8.3 mg/dL (8.7-10.2), 25-OH-vitamin D 54 ng/mL (30-100), phosphorus 2.8 mg/dL (2.8-4.1), intact parathyroid hormone 65 pg/mL (15-65), bone-specific alkaline phosphatase 21 mcg/L (4-27), 24-hour urine calcium 156 mg/day (100-300), 24-hour urine phosphorus 1,752 mg/day (390-1,425), FGF-23: 93 RU/mL (44-215) and 1,25 (OH)2D 92 pg/mL (24-81.5). Dual absorptiometry of the lumbar spine and hip showed osteopenia with Z scores of -2.2 and -1.2 respectively. Genetic testing for metabolic bone disease panel showed heterozygous mutation in VDR gene at nucleotide position c.146+9dup associated with autosomal recessive VDDR2A. We present a very rare form of vitamin D resistant rickets. As many patients with VDDR2A are unable to respond to any form of vitamin D, it is suggested that VDDR2 be more appropriately described as hereditary 1,25 (OH)2D resistant rickets (HVDRR), hereditary resistance to 1,25 (OH)2D, or even pseudovitamin D-deficiency type IIA (PDDR IIA). Clinical features include severe rickets, bone pain, hypotonia, dental caries and alopecia. Biochemical features include hypocalcemia, hypophosphatemia, normal to elevated alkaline phosphatase, normal 25(OH)D and importantly, elevated 1,25-(OH)2D levels. Management is with high doses of calcium and vitamin D therapy. While rare, this disease highlights the need for a comprehensive evaluation of metabolic bone diseases and a thorough understanding of calcium and vitamin D metabolism. Presentation: 6/2/2024

Serum 25-hydroxyvitamin D, genetic susceptibility and abdominal aortic aneurysm risk.

The association of serum 25-hydroxyvitamin D [25(OH)D] and genetic polymorphisms of the vitamin D receptor (VDR), and the vitamin D binding protein (VDBP) with incident abdominal aortic aneurysm (AAA) remains uncertain. To investigate whether serum 25(OH)D, genetic polymorphisms of VDR and VDBP, genetic susceptibility to AAA, and the interactions among these factors influence the risk of incident AAA. Retrospective cohort study. UK Biobank. 447,529 participants without a diagnosis of prevalent aortic aneurysm or aortic dissection at baseline. Serum 25(OH)D concentration. Incident AAA. During a median follow-up of 12.5 years, 2,042 participants developed incident AAA. A significant inverse association between serum 25(OH)D and incident AAA was observed (per SD increment, HR, 0.92; 95%CI, 0.88-0.96), which was particularly pronounced in older individuals and those without diabetes (both P for interaction <0.05). Compared to participants with serum 25(OH)D ≥ 50 nmol/L, those with serum 25(OH)D between 25 and <50 nmol/L and <25 nmol/L exhibited a significant higher risk of incident AAA. In the 371,621 participants with genetics assessment, individuals carrying AA alleles of ApaI SNP had a significant increased risk of incident AAA compared to those carrying CC alleles (HR, 1.16; 95%CI, 1.02-1.32). The inverse association between serum 25(OH)D and incident AAA was stronger in individuals with intermediate or high genetic risk for AAA (P for interaction = 0.048). There was a significant inverse association between serum 25(OH)D and AAA incidence, particularly among individuals with higher genetic risk for AAA, older age, and without diabetics.

The Expression of Vitamin D Receptor on Peripheral Blood Mononuclear Cells in Patients with Psoriasis.

Vitamin D plays an important role in psoriasis, but its involvement in pathogenesis remains unclear. This study aimed to evaluate vitamin D receptor (VDR) expression on peripheral blood mononuclear cells (PBMCs) in patients with psoriasis and healthy controls and to study the effects of the Etanercept treatment on VDR expression on PBMCs in patients with psoriasis. Twenty patients with moderate to severe psoriasis received treatment with Etanercept for 24 weeks. The age- and sex-matched controls did not receive any intervention. VDR expression on CD3+ lymphocytes and CD14+ monocytes, and serum levels of total and free 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxy vitamin D (1,25(OH)2D) were analyzed at baseline, after 10-12 weeks, and after 24 weeks in both groups. VDR expression was analyzed using flow cytometry. We observed higher expression of the VDR on CD14+ monocytes in psoriasis patients compared to healthy controls at baseline. This difference was no longer significant after 24 weeks of the Etanercept treatment. The patients with psoriasis improved clinically. However, VDR expression was unaltered during the Etanercept treatment, and there was no correlation between VDR expression and disease severity.

Vitamin D receptor is associated with prognostic characteristics of breast cancer after neoadjuvant chemotherapy-an observational study.

Breast cancer (BC) is the most commonly diagnosed malignant tumor in women. The disease and its subsequent treatment pose a serious burden on the quality of life of patients. Neoadjuvant chemotherapy (NAC) has become one of the crucial strategies for the management of BC. Since the identification of the vitamin D receptor (VDR) in mammary tissues, extensive mechanistic research has been conducted on its function. The expression of VDR in BC cells and the tumor microenvironment could be a new prognostic factor for BC after NAC. This observational, single-center study compared data from clinical and histopathological records of 111 female subjects with the expression of VDR in different cellular and tissue components of breast specimens obtained from surgery after NAC. VDR expression was evaluated using an immunoreactive score assigned after immunohistochemistry. Intergroup comparisons and logistic regression were used to identify associations between VDR expression and clinicopathological features of BC. We found that the expression of VDR is associated with various clinical features (i.e., age, menopausal status, and NAC cycle number) and characteristics of prognostic significance, such as residual cancer burden class. Logistic regression analysis revealed that the expression of VDR in the nuclei and cytoplasm of surrounding normal mammary cells predicted vascular invasion and lymph node involvement. The expression of VDR in tumor cells and their microenvironment is related to the clinicopathological characteristics of BC after NAC.

Vitamin D Receptor Gene Polymorphisms Differentiated Between Tuberculosis Disease and Infection: Causal Association Study.

Latent tuberculosis infection (LTBI) is a critical stage in tuberculosis (TB)control, and few studies have addressed the role of vitamin D receptor(VDR) gene polymorphisms in differentiating between TB and late-onset TB from an immunogenetic perspective. Recruitment of tuberculosis patients and latently infected population in Urumqi, Xinjiang, and use of propensity score matching(PSM) to match the two groups and control confounding to further construct a Bayesian network to analyze causal associations between VDR polymorphisms and tuberculosis disease status. 137 LTBI and 237 TB were obtained through PSM. Logistic regression showed that the VDR gene BsmI locus, TaqI locus, and ApaI locus were associated with a higher risk of TB in a codominant model (P<0.05). Further Bayesian network construction showed that occupation and being a VDR gene BsmI locus were direct influences on TB disease status, and the VDR gene TaqI locus played an indirect role through the BsmI locus, and the probability of TB risk was highest in individuals with manual labour and BsmI locus of the C/T type, which was 84.15%. Bayesian network modelling intuitively revealed that individuals with a C/T type of BsmI locus and physical labour are at high risk of TB compared with TB infection, and they are key factors between with TB disease, providing reference evidence for controlling TB progression.

MRNA expression of vitamin D receptor, calcium-sensing receptor, cyclin D1, and PTH in symptomatic and asymptomatic primary hyperparathyroidism.

The exact underlying mechanism for the differential clinical profiles of symptomatic and asymptomatic primary hyperparathyroidism (PHPT) patients has not been fully elucidated, and efforts to define the molecular mechanisms underlying the phenotypic heterogeneity of PHPT have been limited. The aim of this study was to explore the underlying molecular mechanisms involved in the pathogenesis of symptomatic and asymptomatic sporadic PHPT in Asian Indians. A prospective cohort study was conducted at a tertiary care hospital in North India. PHPT patients who underwent parathyroidectomy were included. The main outcome was the comparison of vitamin D receptor (VDR), calcium-sensing receptor (CaSR), cyclin D 1 (CD1), and parathyroid hormone (PTH) mRNA levels between symptomatic and asymptomatic PHPT patients and controls determined via quantitative real-time polymerase chain reaction (qRT-PCR). Forty-two PHPT patients were studied. The mean (SD) age was 49.7 (12.8) years. Twenty patients were asymptomatic. The median PTH levels were significantly greater in the symptomatic group than in the asymptomatic group (878 vs 653 pg/mL). CaSR and VDR mRNAs were significantly lower in both symptomatic and asymptomatic patients than in controls. CD1 and PTH mRNAs were significantly increased in symptomatic patients, but not in asymptomatic PHPT patients compared with controls. Symptomatic PHPT patients had significantly greater CD1 mRNA expression and reduced CaSR expression than asymptomatic patients. Symptomatic PHPT patients had significantly greater CD1 mRNA expression and lower CaSR expression than asymptomatic patients, underscoring the importance of the molecular mechanisms underlying the phenotypic heterogeneity of PHPT.

Transcriptomic analysis of genes associated with vitamin D receptor signalling reveals differences between skin cancers.

Vitamin D activates the vitamin D receptor (VDR), which dimerizes preferentially with the retinoid X receptor-α (RXRα). This heterodimer connects with genetic elements responsive to vitamin D, inhibiting or stimulating gene activity. We performed Nanostring® analysis of VDR/RXRα to compare the mRNA expression of this heterodimer and their correlated transcriptomes in non-melanoma skin cancer (basal cell carcinomas (BCC) and squamous cell carcinomas (SCC)) and melanocytic lesions (intradermal nevi (IN), and melanomas (MM)) with control skin. To evaluate VDR, RXRα and other 22 correlated genes in BCC, SCC, IN and MM, paraffin samples had their transcriptomes analysed using Nanostring®, a platform that allows multiple mRNA analyses. There were 46 samples, including 11 BCC, 10 SCC, 10 IN, 12 MM and 3 pools of control skins. Most mRNAs differed between the lesion groups and the control group. BCC and SCC NCOR2 were upregulated; in MM and IN, RXRγ was higher than in the control group. TP53, FOXO3 and MED1 showed a significant difference when we compared the BCC group to the SCC group. Melanoma and intradermal nevi differed only in AhR. VDR and RXRα were lower than the control in all groups. The panel shows a clear difference between the non-melanocytic cancers and, on the other hand, a slight difference between the melanocytic lesions. The study of vitamin D's influence through its receptor and RXRα is an exciting issue for understanding the importance of this pathway, and the present study can impact the prevention and treatment strategies, mainly in non-melanocytic tumours.

The Effect of Vitamin D Supplementation with or without Calcium on Vitamin D Epimer and Metabolites.

A possible role of vitamin D epimers and metabolites in the measurement and response to treatment of vitamin D has been reported recently. Furthermore, the influence of underlying vitamin D receptor (VDR) genetic polymorphisms which have been linked to diseases such as obesity remains unclear. We therefore aimed to examine the influence of vitamin D3 and calcium supplements on vitamin D epimer and metabolite concentrations in subjects with and those without vitamin D receptor (VDR) gene polymorphisms. A total of 277 participants who were part of a randomized intervention trial of vitamin D3 and calcium or a placebo for 6 months had clinical and anthropometric assessments. Blood samples were taken for measurements of vitamin D, epimers and metabolites of vitamin D, four vitamin D receptor gene polymorphism SNPs, namely, BsmI, FokI, TaqI, and ApaI, metabolic and inflammatory markers, and related biochemical variables. Repeated-measures analysis of variance was used to assess the between-group difference in cumulative changes in vitamin D epimers and metabolites at 6 months after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms. Overall, 277 participants, with a mean (±SD) age of 41 ± 12 and 204 (74%) of whom were female, were included in the study. We found no statistically significant differences in vitamin D metabolites or (epimers) between male and females or younger subjects compared to those over 40 years of age except in 7C4 BL (p < 0.05). There was a statistically significant difference in 1,25(OH)2D3 concentrations between subjects with and those without genotypes AG and the allele G SNP2_Taql VDR gene polymorphism. Vitamin D3 concentrations were also significantly lower in subjects with the CC SNP3_Apal gene polymorphism compared to those without the CC SNP3 gene. No statistically significant effects were seen on vitamin D epimers and metabolites concentration in response to supplements before or after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms. The CC SNP3 gene had statistically significant influence on vitamin D3 levels. Vitamin D and/or calcium supplements, however, had no effects on vitamin D epimer and metabolite concentration before or after adjusting for the presence of the 4 VDR genotypes and alleles.

Impact of FokI (rs2228570) and BglI (rs739837) polymorphisms in VDR gene on permanent tooth eruption: A cross-sectional study

IntroductionGenetic polymorphisms who disturb the mineral homeostasis during tooth development and eruption are candidate to clarify the molecular mechanisms involved in changes in the tooth eruption chronology. In this study, we evaluate whether the FokI (rs2228570) and BglI (rs739837) polymorphisms in the Vitamin D receptor (VDR) gene are associated with changes in the chronology of eruption of permanent teeth. Material & methodThis cross-sectional study randomly included 353 biologically unrelated children, both sexes, without systemic impairment or syndromes and history of trauma during the primary dentition. One operator perform the oral clinical examination. The tooth was considered erupted if there was a visible minimum of any tooth surface emerging from the mucosa. Genomic DNA was extracted from buccal epithelial cells from saliva samples. Genotyping was performed by Real-Time Polymerase Chain Reactions using TaqMan® technology. The average of the total number of erupted permanent teeth between the genotypes was compared by the Mann-Whitney test and multivariate Generalized Linear Models (GLM) (α = 5 %). β values with Confidence Interval (CI) 95 % were calculated. ResultsThe heterozygous adenine-guanine genotype of the FokI significantly decreases the number of erupted permanent teeth (β = −1.15; CI 95 % = −2.22 to −0.07; p = 0.036). In the stratified analysis for maxillary and mandibular teeth, this genotype was associated with a decrease in the number of erupted maxillary permanent teeth (β = −0.65; CI 95 % = −1.22 to −0.09; p = 0.023). BglI was not associated with permanent teeth eruption. ConclusionThe FokI, but not BglI, in the VDR may delay the eruption of permanent teeth.

Developmental Vitamin D Deficiency and the Vitamin D Receptor Control Hematopoiesis.

Vitamin D status, the vitamin D receptor (VDR), and the ability to produce active vitamin D [1,25(OH)2D, regulated by Cyp27b1] regulate fetal and adult hematopoiesis. Transgenic reporter mice that express the tdTomato RFP as an indication of Vdr expression were used to identify immune cells that express the Vdr. Vdr/tdTomato+ hematopoietic progenitors were identified as early as embryonic day (E)15.5, establishing that these cells have expressed the Vdr and are vitamin D targets. Maternal vitamin D deficiency [D-; serum 25(OH)D < 20 ng/ml] or Vdr knockout or Cyp27b1 knockout resulted in embryos with fewer fetal progenitors. Vdr/tdTomato+ expression was found to increase with age in CD8+ T cells and innate lymphoid cells (ILCs)1 and ILC3, suggesting that initial Vdr expression in these cells is dependent on environmental factors immediately postbirth. In adult tissues, the frequencies of mature T cells and ILCs as well as Vdr/tdTomato expression were reduced by D-. Maternal D- resulted in fewer progenitors that expressed Vdr/tdTomato+ at E15.5 and fewer Vdr/tdTomato+ immune cells in the adult spleen than offspring from D+ mice. We challenged D- mice with H1N1 influenza infection and found that D- mice were more susceptible than D+ mice. Treating D- mice with vitamin D restored Vdr/tdTomato+ expression in splenic T cells and partially restored resistance to H1N1 infection, which shows that developmental D- results in lingering effects on Vdr expression in the adult immune system that compromise the immune response to H1N1 infection. Vitamin D and the Vdr regulate hematopoiesis in both fetal and postnatal phases of immune cell development that impact the immune response to a viral infection.

Vitamin D in Cancer Prevention and Treatment: A Review of Epidemiological, Preclinical, and Cellular Studies.

Inhibition of human carcinomas has previously been linked to vitamin D due to its effects on cancer cell proliferation, migration, angiogenesis, and apoptosis induction. The anticancer activity of vitamin D has been confirmed by several studies, which have shown that increased cancer incidence is associated with decreased vitamin D and that dietary supplementation of vitamin D slows down the growth of xenografted tumors in mice. Vitamin D inhibits the growth of cancer cells by the induction of apoptosis as well as by arresting the cells at the G0/G1 (or) G2/M phase of the cell cycle. Aim and Key Scientific Concepts of the Review: The purpose of this article is to thoroughly review the existing information and discuss and debate to conclude whether vitamin D could be used as an agent to prevent/treat cancers. The existing empirical data have demonstrated that vitamin D can also work in the absence of vitamin D receptors (VDRs), indicating the presence of multiple mechanisms of action for this sunshine vitamin. Polymorphism in the VDR is known to play a key role in tumor cell metastasis and drug resistance. Although there is evidence that vitamin D has both therapeutic and cancer-preventive properties, numerous uncertainties and concerns regarding its use in cancer treatment still exist. These include (a) increased calcium levels in individuals receiving therapeutic doses of vitamin D to suppress the growth of cancer cells; (b) hyperglycemia induction in certain vitamin D-treated study participants; (c) a dearth of evidence showing preventive or therapeutic benefits of cancer in clinical trials; (d) very weak support from proof-of-principle studies; and (e) the inability of vitamin D alone to treat advanced cancers. Addressing these concerns, more potent and less toxic vitamin D analogs have been created, and these are presently undergoing clinical trial evaluation. To provide key information regarding the functions of vitamin D and VDRs, this review provided details of significant advancements in the functional analysis of vitamin D and its analogs and VDR polymorphisms associated with cancers.

Cytomegalovirus results in poor graft function via bone marrow-derived endothelial progenitor cells.

Poor graft function (PGF), characterized by myelosuppression, represents a significant challenge following allogeneic hematopoietic stem cell transplantation (allo-HSCT) with human cytomegalovirus (HCMV) being established as a risk factor for PGF. However, the underlying mechanism remains unclear. Bone marrow endothelial progenitor cells (BM-EPCs) play an important role in supporting hematopoiesis and their dysfunction contributes to PGF development. We aim to explore the effects of CMV on BM-EPCs and its underlying mechanism. We investigated the compromised functionality of EPCs derived from individuals diagnosed with HCMV viremia accompanied by PGF, as well as after infected by HCMV AD 169 strain in vitro, characterized by decreased cell proliferation, tube formation, migration and hematopoietic support, and increased apoptosis and secretion of TGF-β1. We demonstrated that HCMV-induced TGF-β1 secretion by BM-EPCs played a dominant role in hematopoiesis suppression in vitro experiment. Moreover, HCMV down-regulates Vitamin D receptor (VDR) and subsequently activates p38 MAPK pathway to promote TGF-β1 secretion by BM-EPCs. HCMV could infect BM-EPCs and lead to their dysfunction. The secretion of TGF-β1 by BM-EPCs is enhanced by CMV through the activation of p38 MAPK via a VDR-dependent mechanism, ultimately leading to compromised support for hematopoietic progenitors by BM EPCs, which May significantly contribute to the pathogenesis of PGF following allo-HSCT and provide innovative therapeutic strategies targeting PGF.

Paricalcitol prevents MAPK pathway activation and inflammation in adriamycin-induced kidney injury in rats.

Activation of the mitogen-activated protein kinase (MAPK) pathway induces uncontrolled cell proliferation in response to inflammatory stimuli. Adriamycin (ADR)-induced nephropathy (ADRN) in rats triggers MAPK activation and pro-inflammatory mechanisms by increasing cytokine secretion, similar to chronic kidney disease (CKD). Activation of the vitamin D receptor (VDR) plays a crucial role in suppressing the expression of inflammatory markers in the kidney and may contribute to reducing cellular proliferation. This study evaluated the effect of pre-treatment with paricalcitol on ADRN in renal inflammation mechanisms. Male Sprague-Dawley rats were implanted with an osmotic minipump containing activated vitamin D (paricalcitol, Zemplar, 6 ng/day) or vehicle (NaCl 0.9%). Two days after implantation, ADR (Fauldoxo, 3.5 mg/kg) or vehicle (NaCl 0.9%) was injected. The rats were divided into four experimental groups: control, n = 6; paricalcitol, n = 6; ADR, n = 7 and, ADR + paricalcitol, n = 7. VDR activation was demonstrated by increased CYP24A1 in renal tissue. Paricalcitol prevented macrophage infiltration in the glomeruli, cortex, and outer medulla, prevented secretion of tumor necrosis factor-α, and interleukin-1β, increased arginase I and decreased arginase II tissue expressions, effects associated with attenuation of MAPK pathways, increased zonula occludens-1, and reduced cell proliferation associated with proliferating cell nuclear antigen expression. Paricalcitol treatment decreased the stromal cell-derived factor 1α/chemokine C-X-C receptor type 4/β-catenin pathway. Paricalcitol plays a renoprotective role by modulating renal inflammation and cell proliferation. These results highlight potential targets for treating CKD.

The effect of exogenous and genetic factors on a decrease in bone mineral density in children with cystic fibrosis

Osteoporosis is acomplication of cystic fibrosis, the relevance of studying which is associated with an increase in the life expectancy of patients and an increase in the proportion of adults in the general patient population. The aim of the research is to study exogenous and genetic factors of bone mineral density reduction in patients with cystic fibrosis and healthy children. Methods. 100 children with cystic fibrosis and 61 healthy children over 6 years old were examined. All children underwent X-ray densitometry with the DEXXUM device (South Korea). Vitamin D intake, dietary calcium intake and physical activity were assessed using aquestionnaire. Vitamin D levels were assessed by enzyme immunoassay based on the blood content of its intermediate metabolite 25(OH)D. The determination of biochemical parameters was carried out in the CMD laboratory using the enzyme immunoassay method. Polymorphisms of the VDR, COL1A1, and CALCR genes were analyzed by restriction analysis (PDRF). Results. It was found that patients with CF (38%) are more likely to have low BMD compared with healthy children (18%). Low indicators of nutritional status had anegative impact on the BMD. The processes of osteoresorption prevail over the processes of osteogenesis in CF. The features of the course of the disease neutralize the influence of genetic factors that have been identified in healthy children. The effect of dietary calcium intake was significant for healthy children and had no effect on BMD in patients with CF, since patients adhere to acalcium-enriched diet. The effect of the CALCR and COL1A1 genes and dietary calcium intake on the BMD of healthy children has been established. Conclusion. In cystic fibrosis, the leading risk factors for decreased bone mineral density are: ahistory of meconium ileus, chronic infection with Pseudomonas aeruginosa, low nutritional status, and decreased pulmonary function (FEV1,% predicted). For healthy children, the influence of the CALCR and COL1A1 genes and dietary calcium intake are significant.

Discovery of vitexin as a novel VDR agonist that mitigates the transition from chronic intestinal inflammation to colorectal cancer

Colitis-associated colorectal cancer (CAC) frequently develops in patients with inflammatory bowel disease (IBD) who have been exposed to a prolonged state of chronic inflammation. The investigation of pharmacological agents and their mechanisms to prevent precancerous lesions and inhibit their progression remains a significant focus and challenge in CAC research. Previous studies have demonstrated that vitexin effectively mitigates CAC, however, its precise mechanism of action warrants further exploration. This study reveals that the absence of the Vitamin D receptor (VDR) accelerates the progression from chronic colitis to colorectal cancer. Our findings indicate that vitexin can specifically target the VDR protein, facilitating its translocation into the cell nucleus to exert transcriptional activity. Additionally, through a co-culture model of macrophages and cancer cells, we observed that vitexin promotes the polarization of macrophages towards the M1 phenotype, a process that is dependent on VDR. Furthermore, ChIP-seq analysis revealed that vitexin regulates the transcriptional activation of phenazine biosynthesis-like domain protein (PBLD) via VDR. ChIP assays and dual luciferase reporter assays were employed to identify the functional PBLD regulatory region, confirming that the VDR/PBLD pathway is critical for vitexin-mediated regulation of macrophage polarization. Finally, in a mouse model with myeloid VDR gene knockout, we found that the protective effects of vitexin were abolished in mid-stage CAC. In summary, our study establishes that vitexin targets VDR and modulates macrophage polarization through the VDR/PBLD pathway, thereby alleviating the transition from chronic colitis to colorectal cancer.

Association of VDR Polymorphisms with Muscle Mass Development in Elite Young Soccer Players: A Pilot Study.

The vitamin D receptor (VDR) is an important candidate gene in musculoskeletal phenotypes. Polymorphisms in the VDR have been previously associated with several pathologies and muscular strength in athletes and elderly people; however, the literature reported contradictory results. The object of this research was to verify the association between the most studied VDR variants (rs2228570, rs7975232, and rs1544410) and the increase in muscle mass in elite young soccer players. A sample of 55 soccer players (15-18 years old) from a professional team were selected for this study. DNA was extracted by the salting-out method, and polymorphisms were genotyped by PCR-RFLP, followed by 2% agarose gel electrophoresis. To test the effect of the three SNPs (single nucleotide polymorphisms), a logistic regression analysis was applied. The body composition determination was carried out through the skinfold thickness method, and the muscular area of the arm and lower limb were calculated using the Frisancho formula. All three polymorphisms met the Hardy-Weinberg equilibrium (p > 0.05) and their frequencies fell within the worldwide variability. A significant correlation between rs1544410 and the increase in calf muscle mass was observed. Individuals carrying the A allele showed higher calf muscular mass than those carrying the G allele (p = 0.034). Moreover, a haplotype analysis applied to the two SNPs in linkage disequilibrium (rs7975232 and rs1544410) showed that the AG haplotype appeared negatively correlated to the calf muscle area. In conclusion, we confirm an association between VDR polymorphisms and muscular mass that could encourage the genetic screening of the VDR gene to identify a potential risk of injury and for individual nutritional interventions.