Large-scale in silico and microarray-based identification of direct 1,25-dihydroxyvitamin D3 target genes

Maternal Vitamin D Deficiency Causes Sustained Impairment of Lung Structure and Function and Increases Susceptibility to Hyperoxia-induced Lung Injury in Infant Rats

Vitamin D deficiency (VDD) during pregnancy is associated with increased respiratory morbidities and risk for chronic lung disease after preterm birth. However, the direct effects of maternal VDD on perinatal lung structure and function and whether maternal VDD increases the susceptibility of lung injury due to hyperoxia are uncertain. In the present study, we sought to determine whether maternal VDD is sufficient to impair lung structure and function and whether VDD increases the impact of hyperoxia on the developing rat lung. Four-week-old rats were fed VDD chow and housed in a room shielded from ultraviolet A/B light to achieve 25-hydroxyvitamin D concentrations <10 ng/ml at mating and throughout lactation. Lung structure was assessed at 2 weeks for radial alveolar count, mean linear intercept, pulmonary vessel density, and lung function (lung compliance and resistance). The effects of hyperoxia for 2 weeks after birth were assessed after exposure to fraction of inspired oxygen of 0.95. At 2 weeks, VDD offspring had decreased alveolar and vascular growth and abnormal airway reactivity and lung function. Impaired lung structure and function in VDD offspring were similar to those observed in control rats exposed to postnatal hyperoxia alone. Maternal VDD causes sustained abnormalities of distal lung growth, increases in airway hyperreactivity, and abnormal lung mechanics during infancy. These changes in VDD pups were as severe as those measured after exposure to postnatal hyperoxia alone. We speculate that antenatal disruption of vitamin D signaling increases the risk for late-childhood respiratory disease.

Myogenic, genomic and non-genomic influences of the vitamin D axis in skeletal muscle

Despite vitamin D-deficiency clinically presenting with myopathy, muscle weakness and atrophy, the mechanisms by which vitamin D exerts its homeostatic effects upon skeletal muscle remain to be fully established. Recent studies have shown that the receptor by which 1α,25-dihydroxyvitamin D₃ (1,25[OH]₂ D₃ ) exerts its biological actions (ie, the vitamin D receptor, VDR) elicits both genomic and non-genomic effects upon skeletal muscle. The controversy surrounding skeletal muscle VDR mRNA/protein expression in post-natal muscle has been allayed by myriad recent studies, while dynamic expression of VDR throughout myogenesis, and association of higher VDR levels during muscle regeneration/immature muscle cells, suggests a role in myogenesis and perhaps an enrichment of VDR in satellite cells. Accordingly, in vitro studies have demonstrated 1,25(OH)₂ D₃ is anti-proliferative in myoblasts, yet pro-differentiation in latter stages of myogenesis. These effects involve modulation of gene expression (VDR as a transcriptional co-activator controls ~3% of the genome) and post-genomic intracellular signalling for example, via c-Src and alterations to intramuscular calcium homeostasis and proteostasis. The aim of this review is to consider the biomolecular role for the vitamin D/VDR axis in myogenesis, while also exploring global evidence for genomic and non-genomic mechanisms of action for 1,25(OH)₂ D₃ /VDR.

Vitamin D deficiency downregulates TASK-1 channels and induces pulmonary vascular dysfunction

Vitamin D (VitD) receptor regulates the expression of several genes involved in signaling pathways affected in pulmonary hypertension (PH). VitD deficiency is highly prevalent in PH, and low levels are associated with poor prognosis. We investigated if VitD deficiency may predispose to or exacerbate PH. Male Wistar rats were fed with a standard or a VitD-free diet for 5 wk. Next, rats were further divided into controls or PH, which was induced by a single dose of Su-5416 (20 mg/kg) and exposure to hypoxia (10% O2) for 2 wk. VitD deficiency had no effect on pulmonary pressure in normoxic rats, indicating that, by itself, it does not trigger PH. However, it induced several moderate but significant changes characteristic of PH in the pulmonary arteries, such as increased muscularization, endothelial dysfunction, increased survivin, and reduced bone morphogenetic protein ( Bmp) 4, Bmp6, DNA damage-inducible transcript 4, and K+ two - pore domain channel subfamily K member 3 ( Kcnk3) expression. Myocytes isolated from pulmonary arteries from VitD-deficient rats had a reduced whole voltage-dependent potassium current density and acid-sensitive (TASK-like) potassium currents. In rats with PH induced by Su-5416 plus hypoxia, VitD-free diet induced a modest increase in pulmonary pressure, worsened endothelial function, increased the hyperreactivity to serotonin, arterial muscularization, decreased total and TASK-1 potassium currents, and further depolarized the pulmonary artery smooth muscle cell membrane. In human pulmonary artery smooth muscle cells from controls and patients with PH, the active form of VitD calcitriol significantly increased KCNK3 mRNA expression. Altogether, these data strongly suggest that the deficit in VitD induces pulmonary vascular dysfunction.

A single bout of high-intensity exercise modulates the expression of vitamin D receptor and vitamin D-metabolising enzymes in horse skeletal muscle

BACKGROUND

The expressions of vitamin D receptor (VDR) and vitamin D-metabolising enzymes (CYP27B1 and CYP24A1) in skeletal muscle have been reported. However, the regulation of this vitamin D system in horse skeletal muscle after high-intensity exercise has not yet been elucidated.

OBJECTIVES

To investigate the effect of high-intensity exercise on the expression of vitamin D system-related proteins in horse skeletal muscle and its associations with skeletal muscle stem cell (SMSC) activity and serum 25(OH)D level.

STUDY DESIGN

Longitudinal study.

METHODS

Six healthy ponies (5 geldings, 1 mare; age 6.3 ± 2.2 years) were studied. Serum and muscle samples were taken from the jugular vein and gluteus medius respectively. Samples were collected at pre-exercise, post-exercise, 1 and 3 weeks after a single bout of high-intensity exercise. Protein expression levels of VDR, CYP27B1, CYP24A1, OxPhos and Pax7 (SMSC marker) were determined using immunohistochemical analysis. Oxidative capacity and intramuscular glycogen content were evaluated using histochemical analysis. Blood biochemistry was analysed for lactate concentration and creatine kinase (CK), and 25(OH)D activity.

RESULTS

High-intensity exercise significantly upregulated Pax7 and VDR protein expression, which correlated with significantly increased blood lactate and serum CK levels immediately post-exercise. Serum 25(OH)D₂ level correlated with CYP27B1 protein expression in skeletal muscle, and it reduced significantly immediately post-exercise and at 1 and 3 weeks post-exercise. However, CYP24A1 protein expression was unchanged throughout study periods.

MAIN LIMITATION

The healthy ponies could not represent a fit population of racehorses and eventers.

CONCLUSIONS

The rapid increase in Pax7 and VDR protein expression along with serum CK level after high-intensity exercise demonstrated an association between SMSC activity and activation of the vitamin D system in response to muscle injury in horses. Moreover, a decrease in CYP27B1 protein expression, correlated with a reduction in serum 25(OH)D₂ , may indicate a compromised vitamin D metabolism after high-intensity exercise.

Can Brain Health Be Supported by Vitamin D-Based Supplements? A Critical Review

This review presents recent knowledge on the neuroprotective effects of vitamin D and their usefulness as oral supplementation when combined with other molecules, such as curcumin. A critical look at the effectiveness of vitamin D in this field is also provided. Vitamin D plays a crucial role in neuroprotection and in the cognitive decline associated with aging, where vitamin D’s levels are related to the levels of several neurotrophic factors. An important role of vitamin D has also been observed in the mechanism of neuroinflammation, which is the basis of several aging conditions, including cognitive decline and neurodegeration; furthermore, the neuroprotective effect of vitamin D in the cognitive decline of aging has recently been reported. For this reason, many food supplements created for humans contain vitamin D alone or combined with other molecules with antioxidant properties. However, recent studies also explored negative consequences of the use at a high dosage of vitamin D. Vitamin D in tissues or brain cells can also modulate calbindin-D28K, parvalbumin, and calretinin, and is involved in immune function, thanks also to the combination with curcumin. Curcumin acts as a free radical scavenger and antioxidant, inhibiting lipid peroxidation and oxidative DNA damage. In particular, curcumin is a potent immune-regulatory agent and its administration has been reported to attenuate cognitive impairments. These effects could be exploited in the future to control the mechanisms that lead to the brain decay typical of neurodegenerative diseases.

Action of 1,25(OH)2D3 on Human Asthmatic Bronchial Fibroblasts: Implications for Airway Remodeling in Asthma

Background

Airway fibroblasts are major contributors to the histopathological feature of airway remodeling in asthma by their implication in the cell invasiveness and profibrogenic secretory phenotype observed in subepithelial fibrosis. 1,25 Dihydroxy vitamin D₃ (1,25(OH)₂D₃) is an important therapeutic agent that blocks many features of airway remodeling induced by profibrogenic mediators, such as transforming growth factor beta 1 (TGF-β1) or T helper type 1 inflammatory cytokines.

Objective

We hypothesized that 1,25(OH)₂D₃ opposes the TGF-β1 or tumor necrosis factor alpha (TNF-α)-Interleukin 1 beta (IL-1β) stimulation on airway fibroblast profibrogenic secretory phenotype observed in severe asthmatic patients. Our aim was to investigate the anti-fibrogenic effect of 1,25(OH)₂D₃ in TGF-β1 or TNF-α-IL-1β-stimulated human bronchial fibroblast cells (HBFCs) from severe asthmatic compared with non-asthmatic subjects.

Patients and Methods

All experiments were performed on primary HBFCs from asthmatic (DHBFCs, n=4) and non-asthmatic subjects (NHBFCs, n=4). mRNA expression and protein quantification of key fibrogenic markers were analyzed by RT-qPCR and ELISA, comparing HBFCs from asthmatic and non-asthmatic subjects. Vitamin D receptor (VDR) mRNA expression and its functionality in HBFCs were assessed by RT-qPCR. HBFCs proliferation was assessed by flow cytometry using BrdU-FITC/7AAD bivariate staining, while HBFCs apoptosis by Annexin V-FITC/7AAD.

Results

VDR is constitutively expressed in HBFCs and the addition of 1,25(OH)₂D₃ significantly increased mRNA expression of CYP24A1 (a direct VDRs’ target gene) in both HBFCs groups. DHBFCs cultured in the presence of TGF-β1 or TNF-α-IL-1β showed increased mRNA expression and protein secretion of fibrogenic markers when compared to NHBFCs. Additionally, we observed decreased mRNA expression of FN 1, LUM, BGN, MMP2, COL5A1, TIMP1 and CC-chemokines (CCL2, CCL5, CCL11) in response to 1,25(OH)₂D₃ addition to the TGF-β1 or TNF-α-IL-1β-stimulated HBFCs. Cell culture media obtained from TGF-β1 or TNF-α-IL-1β-stimulated DHBFCs showed decreased protein secretion (fibronectin 1, lumican, MCP1, RANTES and eotaxin-1) in response to 1,25(OH)₂D₃ when compared to NHBFCs. 1,25(OH)₂D₃ inhibited proliferation in TGF-β1-stimulated HBFCs through G0/G1 cell cycle arrest and these effects were not correlated with the induction of apoptosis.

Conclusion

DHBFCs under TGF-β1 or TNF-α-IL-1β stimulation showed higher fibrogenic capacity when compared to NHBFCs. 1,25(OH)₂D₃ significantly blocked these effects and highlight 1,25(OH)₂D₃ as a possible therapeutic target for severe asthma.

Inhibition of HAS2 and hyaluronic acid production by 1,25-Dihydroxyvitamin D3 in breast cancer

1,25-Dihydroxyvitamin D₃ (1,25D3) induces growth arrest and apoptosis in breast cancer cells in vivo and in vitro, however the exact mechanisms are unclear. Although the vitamin D receptor (VDR), a ligand dependent transcription factor, is required for growth regulation by vitamin D, the specific target genes that trigger these effects are unknown. Genomic profiling of murine mammary tumor cells with differential VDR expression identified 35 transcripts that were altered by the 1,25D3-VDR complex including Hyaluronan Synthase-2 (Has2). Here we confirmed that 1,25D3 reduces both HAS2 gene expression and hyaluronic acid (HA) synthesis in multiple models of breast cancer. Furthermore, we show that the growth inhibitory effects of 1,25D3 are partially reversed in the presence of high molecular weight HA. HAS2 expression and HA production are elevated in immortalized human mammary epithelial cells induced to undergo epithelial-mesenchymal transition (EMT) through stable expression of TGFβ, SNAIL or TWIST and in those expressing oncogenic H-RAS^V12, indicating that deregulation of HA production may be an early and frequent event in breast tumorigenesis. 1,25D3 also reduces HA secretion and acts additively with an HA synthesis inhibitor to slow growth of cells expressing TGFβ, SNAIL and TWIST. Analysis of mammary gland and tumors from Vdr knockout mice suggest that loss of VDR is associated with enhanced HAS2 expression and HA production in vivo. These data define a novel role for 1,25D3 and the VDR in control of HA synthesis in epithelial tissues that likely contributes to its anti-cancer actions.

Impact of the Local Inflammatory Environment on Mucosal Vitamin D Metabolism and Signaling in Chronic Inflammatory Lung Diseases

Vitamin D plays an active role in the modulation of innate and adaptive immune responses as well as in the protection against respiratory pathogens. Evidence for this immunomodulatory and protective role is derived from observational studies showing an association between vitamin D deficiency, chronic airway diseases and respiratory infections, and is supported by a range of experimental studies using cell culture and animal models. Furthermore, recent intervention studies have now shown that vitamin D supplementation reduces exacerbation rates in vitamin D-deficient patients with chronic obstructive pulmonary disease (COPD) or asthma and decreases the incidence of acute respiratory tract infections. The active vitamin D metabolite, 1,25-dihydroxy-vitamin D (1,25(OH)₂D), is known to contribute to the integrity of the mucosal barrier, promote killing of pathogens (via the induction of antimicrobial peptides), and to modulate inflammation and immune responses. These mechanisms may partly explain its protective role against infections and exacerbations in COPD and asthma patients. The respiratory mucosa is an important site of local 1,25(OH)₂D synthesis, degradation and signaling, a process that can be affected by exposure to inflammatory mediators. As a consequence, mucosal inflammation and other disease-associated factors, as observed in e.g., COPD and asthma, may modulate the protective actions of 1,25(OH)₂D. Here, we discuss the potential consequences of various disease-associated processes such as inflammation and exposure to pathogens and inhaled toxicants on vitamin D metabolism and local responses to 1,25(OH)₂D in both immune- and epithelial cells. We furthermore discuss potential consequences of disturbed local levels of 25(OH)D and 1,25(OH)₂D for chronic lung diseases. Additional insight into the relationship between disease-associated mechanisms and local effects of 1,25(OH)₂D is expected to contribute to the design of future strategies aimed at improving local levels of 1,25(OH)₂D and signaling in chronic inflammatory lung diseases.

Analysis of 25-hydroxy cholecalciferol, immunoglobulin E, and vitamin D receptor single nucleotide polymorphisms (Apa1, Taq1, and Bsm1), among sample of Egyptian children with bronchial asthma: A case-control study

PURPOSE

The current study aimed to assess the serum levels of vitamin D and immunoglobulin E (IgE) among asthmatic Egyptian children and to find out the possible associations of vitamin D receptor (VDR) polymorphisms with bronchial asthma development.

METHODS

The study included 100 Egyptian children, 50 asthmatic children who were comparable with 50 age, sex, and body mass index-matched, unrelated healthy controls (HCs) clinical assessments of asthmatic children were done using global initiative of asthma. Pulmonary function tests (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC ratio) were performed. Enzyme-linked immunosorbent assays of serum vitamin D3 and total IgE were done. VDR-single nucleotide polymorphisms (SNPs) (ApaI, TaqI, and BsmI) detection has performed using polymerase chain reaction through restriction fragment length polymorphism technique. Data analysis was performed using SPSS version 20.0. The studied SNPs were followed the Hardy Weinberg equation.

RESULTS

The mean serum level of 25(OH) D3 was significantly lower among asthmatic children (13.46 ng/mL ± 10.50 SD) in comparison to HCs (37.53 ng/mL ± 13. 0.40 SD), P < .05. Vitamin D deficiency was detected in 72% of cases with no significant difference in its level regarding asthma control. There was significantly higher IgE level among asthmatic children (99.83 ku/L ± 233.81 SD) versus HCs (7.52 ku/L ± 3.32 SD), P < .05. Asthmatic children were presented more commonly with TaqI t allele (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.28-3.96; P < .05) and BsmI b allele (OR, 1.83; 95% CI, 1.05-3.21; P < .05). ApaI a allele was not significantly different among patients versus controls (P > .05). TT + Tt and Bb + bb genotypes were significantly higher among cases versus the controls, P < .05 for all.

CONCLUSIONS

TaqI and BsmI were associated with risk of bronchial asthma development among Egyptian children. High IgE and Low vitamin D status were frequently occurring among asthmatic children.

A Review of the Relationship Between Vitamin D and Parkinson Disease Symptoms

Vitamin D is a fat-soluble secosteroid that exerts its effects by binding to the vitamin D receptor (VDR), through which it directly and indirectly modulates the expression of hundreds to thousands of genes. While originally known for its role in regulating calcium homeostasis and metabolism, vitamin D is now associated with many other health conditions, including Parkinson's disease (PD). A high prevalence of vitamin D deficiency has been noted in PD for at least the past two decades. These findings, along with the discovery that the VDR and 1α-hydroxylase, the enzyme that converts vitamin D to its active form, are highly expressed in the substantia nigra, led to the hypothesis that inadequate levels of circulating vitamin D may lead to dysfunction or cell death within the substantia nigra. Studies investigating the relationship between vitamin D status and PD, however, have been inconsistent. Two prospective studies examined the association between mid-life vitamin D levels and risk of PD and produced conflicting results-one demonstrated an increased risk for PD with lower mid-life vitamin D levels, and the other showed no association between vitamin D and PD risk. One of the most consistent findings in the literature is the inverse association between serum vitamin D level and motor symptom severity in cross-sectional studies. While these data suggest that vitamin D may modify the disease, another likely explanation is confounding due to limited mobility. Fall risk has been associated with vitamin D in PD, but more study is needed to determine if supplementation decreases falls, which has been demonstrated in the general population. The association between vitamin D and non-motor symptoms is less clear. There is some evidence that vitamin D is associated with verbal fluency and verbal memory in PD. Studies in PD have also shown associations between vitamin D status and mood, orthostatic hypotension and olfactory impairment in PD. While more research is needed, given the numerous potential benefits and limited risks, vitamin D level assessment in PD patients and supplementation for those with deficiency and insufficiency seems justified.

The Influence of Vitamin D on Neurodegeneration and Neurological Disorders: A Rationale for its Physio-pathological Actions

Vitamin D is a steroid hormone implicated in the regulation of neuronal integrity and many brain functions. Its influence, as a nutrient and a hormone, on the physiopathology of the most common neurodegenerative diseases is continuously emphasized by new studies. This review addresses what is currently known about the action of vitamin D on the nervous system and neurodegenerative diseases such as Multiple Sclerosis, Alzheimer's disease, Parkinson's disease and Amyotrophic Lateral Sclerosis. Further vitamin D research is necessary to understand how the action of this "neuroactive" steroid can help to optimize the prevention and treatment of several neurological diseases.

Rs739837 affects the severity of asthma by disrupting the binding of microRNA-885

Aim: This study investigated the molecular mechanism underlying the involvement of miR-885 in the signaling pathways of VDR. Results: Based on their rs739837 genotype, the subjects were divided into a case group and a control group. Logistic regression was carried out to study the impact of rs739837 genotypes on the severity of asthma, and it was found that the minor allele (T) of rs739837 significantly increased the severity of asthma. Using a luciferase assay, VDR was confirmed as a miR-885 target, with a negative regulatory relationship established between VDR and miR-885. Conclusion: The findings of this study demonstrated that VDR is an miR-885 target, while the presence of rs739837 minor allele (T) in miR-885 interferes with the interaction between miR-885 and VDR to affect the severity of asthma.

The Influence of Nutrients on Inflammatory Bowel Diseases

Inflammatory bowel diseases is a group of inflammatory diseases. The pathogenesis of diseases is multifactorial, which may include a Western-type diet. Diseases occur with periods of recurrence and remission. Many factors can have a beneficial effect on reducing the frequency of recurrence and prolonging the remission period. Such ingredients include dietary fibre, mono- and polyunsaturated fatty acids, certain vitamins (D, C, and E), flavonoids, and minerals such as zinc and selenium. Properly selected nutrition might be an integral part of the treatment of patients with Crohn's disease or ulcerative colitis.

Neuron-Specific Vitamin D Signaling Attenuates Microglia Activation and CNS Autoimmunity

Low vitamin D during childhood is associated with an increased risk of developing multiple sclerosis (MS) as an adult. Given that vitamin D has anti-inflammatory properties, it has been postulated that the relationship between MS and low vitamin D is due to immune dysregulation. Since the vitamin D receptor (VDR) is expressed in many cell types, this study investigated an alternative hypothesis-neuron-specific VDR signaling induces anti-inflammatory molecules that protect the central nervous system from autoimmunity. Using media from neurons treated with calcitriol, the active form of vitamin D3, LPS-activated microglia had a reduction in pro-inflammatory molecules, and a reciprocal induction of anti-inflammatory molecules. Since IL-34 is critical to the homeostasis of microglia, and was previously shown to be induced in endothelial cells by vitamin D, we investigated IL-34 as the potential anti-inflammatory molecule induced in neurons by vitamin D. Treatment of LPS-activated microglia with IL-34 reduced pro-inflammatory cytokine production and enhanced the expression of anti-inflammatory transcripts. However, neutralizing IL-34 in vitamin D neuronal conditioned media only impacted IL-6 and not the broader anti-inflammatory phenotype of microglia. To mimic low vitamin D in children, we used a neuron-specific inducible mouse model in which VDR was partially deleted in juvenile mice. Partial deletion of VDR in neurons during early life resulted in exacerbated CNS autoimmunity in adult mice. Overall, the study illustrated that vitamin D signaling in neurons promotes an anti-inflammatory state in microglia, and low vitamin D in early life may enhance CNS autoimmunity.

Role of Vitamin D in Autism Spectrum Disorder

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Autism spectrum disorder (ASD) is a pervasive developmental disorder with heterogeneous etiology. Vitamin D can function as a fat-soluble vitamin as well as a hormone, and can exert its effect through both genomic and non-genomic mechanisms. In the last decades, several studies have examined the relationship between vitamin D levels and ASD. These studies demonstrated that low vitamin D status in early development has been hypothesized as an environmental risk factor for ASD. Both in vivo and in vitro studies have demonstrated that vitamin D deficiency in early life can alter brain development, dysregulates neurotransmitter balance in the brain, decreases body and brain antioxidant ability, and alters the immune system in ways that resemble pathological features commonly seen in ASD. In this review, we focused on the association between vitamin D and ASD. In addition, the above-mentioned mechanisms of action that link vitamin D deficiency with ASD were also discussed. Finally, clinical trials of vitamin D supplementation treatment of ASD have also been discussed.

TRPV6 as A Target for Cancer Therapy

Two decades ago a class of ion channels, hitherto unsuspected, was discovered. In mammals these Transient Receptor Potential channels (TRPs) have not only expanded in number (to 26 functional channels) but also expanded the view of our interface with the physical and chemical environment. Some are heat and cold sensors while others monitor endogenous and/or exogenous chemical signals. Some TRP channels monitor osmotic potential, and others measure cell movement, stretching, and fluid flow. Many TRP channels are major players in nociception and integration of pain signals. One member of the vanilloid sub-family of channels is TRPV6. This channel is highly selective for divalent cations, particularly calcium, and plays a part in general whole-body calcium homeostasis, capturing calcium in the gut from the diet. TRPV6 can be greatly elevated in a number of cancers deriving from epithelia and considerable study has been made of its role in the cancer phenotype where calcium control is dysfunctional. This review compiles and updates recent published work on TRPV6 as a promising drug target in a number of cancers including those afflicting breast, ovarian, prostate and pancreatic tissues.

The mTOR Signaling Pathway Activity and Vitamin D Availability Control the Expression of Most Autism Predisposition Genes

Autism spectrum disorder (ASD) has a strong and complex genetic component with an estimate of more than 1000 genes implicated cataloged in SFARI (Simon′s Foundation Autism Research Initiative) gene database. A significant part of both syndromic and idiopathic autism cases can be attributed to disorders caused by the mechanistic target of rapamycin (mTOR)-dependent translation deregulation. We conducted gene-set analyses and revealed that 606 out of 1053 genes (58%) included in the SFARI Gene database and 179 out of 281 genes (64%) included in the first three categories of the database (“high confidence”, “strong candidate”, and “suggestive evidence”) could be attributed to one of the four groups: 1. FMRP (fragile X mental retardation protein) target genes, 2. mTOR signaling network genes, 3. mTOR-modulated genes, 4. vitamin D3 sensitive genes. The additional gene network analysis revealed 43 new genes and 127 new interactions, so in the whole 222 out of 281 (79%) high scored genes from SFARI Gene database were connected with mTOR signaling activity and/or dependent on vitamin D3 availability directly or indirectly. We hypothesized that genetic and/or environment mTOR hyperactivation, including provocation by vitamin D deficiency, might be a common mechanism controlling the expressivity of most autism predisposition genes and even core symptoms of autism.

Vitamin D-VDR Signaling Inhibits Wnt/β-Catenin-Mediated Melanoma Progression and Promotes Antitumor Immunity

1α,25-Dihydroxyvitamin D3 signals via the vitamin D receptor (VDR). Higher serum vitamin D is associated with thinner primary melanoma and better outcome, although a causal mechanism has not been established. As patients with melanoma commonly avoid sun exposure, and consequent vitamin D deficiency might worsen outcomes, we interrogated 703 primary melanoma transcriptomes to understand the role of vitamin D-VDR signaling and replicated the findings in The Cancer Genome Atlas metastases. VDR expression was independently protective for melanoma-related death in both primary and metastatic disease. High tumor VDR expression was associated with upregulation of pathways mediating antitumor immunity and corresponding with higher imputed immune cell scores and histologically detected tumor-infiltrating lymphocytes. High VDR-expressing tumors had downregulation of proliferative pathways, notably Wnt/β-catenin signaling. Deleterious low VDR levels resulted from promoter methylation and gene deletion in metastases. Vitamin D deficiency (<25 nmol/L ∼ 10 ng/mL) shortened survival in primary melanoma in a VDR-dependent manner. In vitro functional validation studies showed that elevated vitamin D-VDR signaling inhibited Wnt/β-catenin signaling genes. Murine melanoma cells overexpressing VDR produced fewer pulmonary metastases than controls in tail-vein metastasis assays. In summary, vitamin D-VDR signaling contributes to controlling pro-proliferative/immunosuppressive Wnt/β-catenin signaling in melanoma and this is associated with less metastatic disease and stronger host immune responses. This is evidence of a causal relationship between vitamin D-VDR signaling and melanoma survival, which should be explored as a therapeutic target in primary resistance to checkpoint blockade. SIGNIFICANCE: VDR expression could potentially be used as a biomarker to stratify patients with melanoma that may respond better to immunotherapy.

Calcitriol suppresses lipopolysaccharide-induced alveolar bone damage in rats by regulating T helper cell subset polarization

BACKGROUND

Although the immunomodulatory properties of calcitriol in bone metabolism have been documented for decades, its therapeutic role in the management of periodontitis remains largely unexplored. In this study, we hypothesized that calcitriol suppresses lipopolysaccharide (LPS)-induced alveolar bone loss by regulating T helper (Th) cell subset polarization.

METHODS

To test this hypothesis, we determined the effect of calcitriol intervention on the development of LPS-induced periodontitis in rats in terms of bone loss (micro-CT analysis), local inflammatory infiltration levels, the number of osteoclasts (hematoxylin and eosin staining) and the level of osteoclastogenesis (tartrate-resistant acid phosphatase method). Furthermore, immunohistochemistry was used to assess the expression levels of the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) as well as the cytokine levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-17, and IL-10 throughout the LPS-injected region. Finally, the polarization potential of Th cells in peripheral blood was analyzed using flow cytometry.

RESULTS

Calcitriol intervention decreased alveolar bone loss in response to LPS injection and inflammatory cell infiltration. Analysis of osteoclast number and RANKL and OPG expression showed that bone resorption activity was largely suppressed in response to calcitriol administration, along with decreased IL-17 levels but increased IL-4 and IL-10 levels in periodontal tissues (the LPS-injected region). Similarly, the percentages of Th2 and Treg cells in peripheral blood increased, but the percentages of Th1 and Th17 cells decreased in rats receiving calcitriol.

CONCLUSION

Our findings suggest that calcitriol can be used to inhibit bone loss in experimental periodontitis, likely via the regulation of local and systemic Th cell polarization.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Early Rehabilitation Program and Vitamin D Supplementation Improves Sensitivity of Balance and the Postural Control in Patients after Posterior Lumbar Interbody Fusion: A Randomized Trial

BACKGROUND

The introduction of early rehabilitation exercise is the foundation of treatment post-Posterior lumbar interbody fusion (PLIF) surgery, and the search for additional sources of reinforcement physiotherapy seems to be very important.

METHODS

The patients were randomly divided into the vitamin D3 (n = 15; D3) supplemented group and received 3200 IU per day for five weeks before surgery and the placebo group (n = 18; Pl) received vegetable oil during the same time. The patients began the supervisor rehabilitation program four weeks after surgery.

RESULTS

The limits of stability (LOS) were significantly improved in the D3 group after 5 and 14 weeks (p < 0.05), while in the Pl group, progress was only observed after 14 weeks (p < 0.05). The LOS were also higher in the D3 group than in the Pl group after five weeks of supervised rehabilitation (p < 0.05). In the postural stability (PST) test, significant progress was observed in the D3 group after 14 weeks (p < 0.02). In addition, neither rehabilitation nor supplementation had significant effects on the risk of falls (RFT).

CONCLUSIONS

Vitamin D supplementation seems to ameliorate the effects of an early postoperative rehabilitation program implemented four weeks after posterior lumbar interbody fusion. Early physiotherapy treatment after PLIF surgery combined with vitamin D supplementation appears to be a very important combination with regard to the patients' recovery process.

Vitamin D as a Potential Agent for Ischemic Axonal Regeneration after Epineurial Devascularization of the Sciatic Nerve

BACKGROUND

Although vitamin D has several noncalcemic functions particularly on nervous system, its neuroregenerative roles on ischemic peripheral nerve injury has not been reported. In this study, it was aimed to investigate the effect of vitamin D3 after epineurial devascularization of the sciatic nerve.

METHODS

Forty adult female Wistar rats were randomly divided into four groups: Group 1 (Control), Group 2 (Sham-operated), Group 3 (Epineurial devascularization + vitamin D3 treatment), Group 4 (Epineurial devascularization + vehicle treatment). Recovery of the sciatic nerve was analyzed by functional (sciatic functional index, pinch test and biochemical analyses) and morphological (electron microscopic analysis and wet muscle weight analysis) methods.

RESULTS

Comparison of the data revealed that vitamin D3 administration had a beneficial effect on regeneration after epineurial devascularization.

CONCLUSION

We suggest that vitamin D3 is an effective agent in the prevention of ischemic peripheral nerve insults.

Effects of Vitamin D Use on Outcomes of Psychotic Symptoms in Alzheimer Disease Patients

OBJECTIVE

To identify medications that may prevent psychosis in patients with Alzheimer disease (AD).

METHODS

The authors compared the frequency of medication usage among patients with AD with or without psychosis symptoms (AD + P versus AD - P). The authors also conducted survival analysis on time to psychosis for patients with AD to identify drugs with beneficial effects. The authors further explored the potential molecular mechanisms of identified drugs by gene-signature analysis. Specifically, the gene expression profiles induced by the identified drug(s) were collected to derive a list of most perturbed genes. These genes were further analyzed by the associations of their genetic variations with AD or psychosis-related phenotypes.

RESULTS

Vitamin D was used more often in AD - P patients than in AD + P patients. Vitamin D was also significantly associated with delayed time to psychosis. AD and/or psychosis-related genes were enriched in the list of genes most perturbed by vitamin D, specifically genes involved in the regulation of calcium signaling downstream of the vitamin D receptor.

CONCLUSION

Vitamin D was associated with delayed onset of psychotic symptoms in patients with AD. Its mechanisms of action provide a novel direction for development of drugs to prevent or treat psychosis in AD. In addition, genetic variations in vitamin D-regulated genes may provide a biomarker signature to identify a subpopulation of patients who can benefit from vitamin D treatment.

A complete physical mapping of the vitamin D receptor gene for dental implant loss: A pilot study

OBJECTIVES

The aim of this pilot case-control study was to investigate the association of clinical variables and genetic polymorphisms in the vitamin D receptor gene (VDR) with dental implant loss.

MATERIAL AND METHODS

This study was carried out with 244 individuals with mean age 51.90 ± 11.28 (81 cases and 163 controls matched by age, sex, and smoking habit). Also, the clusterization phenomenon was investigated stratifying the sample into two groups: (a) 34 patients with multiple losses (presenting two or more lost implants) and (b) 210 without multiple losses (up to one implant loss). Sociodemographic, clinical, and periodontal parameters were analyzed. The tagSNPs in the VDR gene were analyzed by real-time PCR. Univariate and multivariate analyses were performed (p < .05).

RESULTS

Edentulism, number of implants installed, and Gingival, Plaque, and Calculus Indexes were associated with implant loss in the univariate analysis. After the multivariate analysis, the allele G of rs3782905 in the recessive model, together with number of installed implants and Gingival Index, was associated with implant failure.

CONCLUSION

It is suggested that the allele G of rs3782905 in the recessive model may be a new genetic risk marker for dental implant loss in patients who lost two or more dental implants. In addition, number of implants installed and Gingival Index were also associated. Replication is mandatory to confirm these findings, due to the modest sample size of this work.

Antimicrobial and Immune-Modulatory Effects of Vitamin D Provide Promising Antibiotics-Independent Approaches to Tackle Bacterial Infections - Lessons Learnt from a Literature Survey

Antimicrobial multidrug-resistance (MDR) constitutes an emerging threat to global health and makes the effective prevention and treatment of many, particularly severe infections challenging, if not impossible. Many antibiotic classes have lost antimicrobial efficacy against a plethora of infectious agents including bacterial species due to microbial acquisition of distinct resistance genes. Hence, the development of novel anti-infectious intervention strategies including antibiotic-independent approaches is urgently needed. Vitamins such as vitamin D and vitamin D derivates might be such promising molecular candidates to combat infections caused by bacteria including MDR strains. Using the Pubmed database, we therefore performed an in-depth literature survey, searching for publications on the antimicrobial effect of vitamin D directed against bacteria including MDR strains. In vitro and clinical studies between 2009 and 2019 revealed that vitamin D does, in fact, possess antimicrobial properties against both Gram-positive and Gram-negative bacterial species, whereas conflicting results could be obtained from in vivo studies. Taken together, the potential anti-infectious effects for the antibiotic-independent application of vitamin D and/or an adjunct therapy in combination with antibiotic compounds directed against infectious diseases such as tuberculosis, H. pylori infections, or skin diseases, for instance, should be considered and further investigated in more detail.

Vitamin D, Skeletal Muscle Function and Athletic Performance in Athletes-A Narrative Review

The active form of vitamin D (calcitriol) exerts its biological effects by binding to nuclear vitamin D receptors (VDRs), which are found in most human extraskeletal cells, including skeletal muscles. Vitamin D deficiency may cause deficits in strength, and lead to fatty degeneration of type II muscle fibers, which has been found to negatively correlate with physical performance. Vitamin D supplementation has been shown to improve vitamin D status and can positively affect skeletal muscles. The purpose of this study is to summarize the current evidence of the relationship between vitamin D, skeletal muscle function and physical performance in athletes. Additionally, we will discuss the effect of vitamin D supplementation on athletic performance in players. Further studies are necessary to fully characterize the underlying mechanisms of calcitriol action in the human skeletal muscle tissue, and to understand how these actions impact the athletic performance in athletes.

Genetic Polymorphisms of Pharmacogenomic VIP Variants in the Circassian Subpopulation from Jordan

BACKGROUND

It has been suggested that genetic variation within candidate pharmacogenes contributes to the differences in drug safety and efficacy as well as risk of adverse drug reactions among different ethnic groups. Illustrating the polymorphic distribution of Very Important Pharmacogenes (VIPs) in various ethnic groups will contribute to the development of personalized medicine for those populations.

OBJECTIVE

The present study aimed to identify the polymorphic distribution of VIPs in the Circassian subpopulation of Jordan and compare their allele frequencies with those of other populations.

METHODS

A total of 130 healthy and unrelated Circassian adults from Jordan were randomly recruited and genotyped for eleven VIP variants within the thiopurine S-methyltransferase (TPMT), ATP-binding cassette, sub-family B, member 1 (ABCB1), and vitamin D receptor (VDR) genes via Sequenom's MassARRAY® genotyping platform (iPLEX GOLD).

RESULTS

Our data on the allelic frequencies of the investigated VIP variants were compared to those of 18 other populations, comprising 11 HapMap populations, 6 Exome Aggregation Consortium populations, and the Chechen- Jordanian population from Jordan. Circassian-Jordanians were found to most resemble the African, Chechen- Jordanian, European (Finnish), European (non-Finnish), and South-Asian populations.

CONCLUSION

Circassians from Jordan significantly differ from other populations in terms of the allelic frequencies of selected VIP variants. The present findings constitute the first set of pharmacogenetic data for Circassian population from Jordan, providing a basis for safe drug administration that may be useful in diagnosing and treating diseases in this ethnic group.

Skeletal and Extraskeletal Actions of Vitamin D: Current Evidence and Outstanding Questions

The etiology of endemic rickets was discovered a century ago. Vitamin D is the precursor of 25-hydroxyvitamin D and other metabolites, including 1,25(OH)2D, the ligand for the vitamin D receptor (VDR). The effects of the vitamin D endocrine system on bone and its growth plate are primarily indirect and mediated by its effect on intestinal calcium transport and serum calcium and phosphate homeostasis. Rickets and osteomalacia can be prevented by daily supplements of 400 IU of vitamin D. Vitamin D deficiency (serum 25-hydroxyvitamin D <50 nmol/L) accelerates bone turnover, bone loss, and osteoporotic fractures. These risks can be reduced by 800 IU of vitamin D together with an appropriate calcium intake, given to institutionalized or vitamin D-deficient elderly subjects. VDR and vitamin D metabolic enzymes are widely expressed. Numerous genetic, molecular, cellular, and animal studies strongly suggest that vitamin D signaling has many extraskeletal effects. These include regulation of cell proliferation, immune and muscle function, skin differentiation, and reproduction, as well as vascular and metabolic properties. From observational studies in human subjects, poor vitamin D status is associated with nearly all diseases predicted by these extraskeletal actions. Results of randomized controlled trials and Mendelian randomization studies are supportive of vitamin D supplementation in reducing the incidence of some diseases, but, globally, conclusions are mixed. These findings point to a need for continued ongoing and future basic and clinical studies to better define whether vitamin D status can be optimized to improve many aspects of human health. Vitamin D deficiency enhances the risk of osteoporotic fractures and is associated with many diseases. We review what is established and what is plausible regarding the health effects of vitamin D.

The Modulatory Action of Vitamin D on the Renin-Angiotensin System and the Determination of Hepatic Insulin Resistance

Vitamin D deficiency or hypovitaminosis D is associated with increased risks of insulin resistance, type 2 diabetes mellitus (T2DM) and its related non-alcoholic fatty liver disease (NAFLD). Meanwhile, inappropriate over-activation of the renin–angiotensin system (RAS) in the liver leads to the hepatic dysfunction and increased risk of T2DM, such as abnormalities in lipid and glucose metabolism. Our previous findings have shown that calcitriol, an active metabolite of vitamin D, reduces hepatic triglyceride accumulation and glucose output in diabetic db/db mice and human hepatocellular cell HepG2 cells under insulin-resistant conditions. Notwithstanding the existence of this evidence, the protective action of vitamin D in the modulation of overexpressed RAS-induced metabolic abnormalities in the liver under insulin resistance remains to be elusive and investigated. Herein, we have reported the potential interaction between vitamin D and RAS; and its beneficial effects on the expression and function of the RAS components in HepG2 cells and primary hepatocytes under insulin-resistance states. Our study findings suggest that hormonal vitamin D (calcitriol) has modulatory action on the inappropriate upregulation of the hepatic RAS under insulin-resistant conditions. If confirmed, vitamin D supplementation might provide a nutraceutical potential as a cost-effective approach for the management of hepatic metabolic dysfunction as observed in T2DM and related NAFLD.

The Vitamin D Receptor Gene Polymorphisms in Asthmatic Children: A Case-Control Study

Background: The association between vitamin D receptor (VDR) polymorphisms and the risk of asthma remains unclear. This study aimed to investigate the effect of VDR gene polymorphisms and VDR mRNA expression levels on respiratory function, nitric oxide levels in expiratory air, and serum vitamin D levels in children with asthma. Materials and Methods: The study included 80 healthy children (control group) and 100 asthmatic children (asthma group) between the age of 5 and 18 years. The VDR genotypes (ApaI, TaqI, and FokI) and VDR mRNA levels were determined in all groups. Results: There was no statistically significant difference in vitamin D levels between the asthma group and the control group (P > 0.05). A significant association was found between both genotype (CC) of the TaqI polymorphism [odds ratio (OR) = 0.2, 95% confidence interval (CI) (0.07-0.5), P = 0.003] and genotype (CA) of ApaI polymorphisms [OR = 0.2, 95% CI (0.07-0.8), P = 0.02], and asthma risk. In addition, when single-nucleotide polymorphism allelic frequencies between asthma and control groups were compared there is no significant association (P > 0.05). When compared to control group, VDR mRNA expression in asthma group decreased in genotypes CC and CA of ApaI and in genotypes TT and TC of TaqI (P < 0.05). Conclusion: The results provide supporting evidence for an association between TaqI and ApaI polymorphisms and asthma susceptibility.

Severe obesity and vitamin D deficiency treatment options before bariatric surgery: a randomized clinical trial

BACKGROUND

Obesity, which has various complications and co-morbidities, is an epidemic issue worldwide. Vitamin D deficiency (VDD) is a well-known metabolic disorder among patients with severe obesity. While they are good candidates for bariatric surgery, this deficiency can affect the outcome of surgery negatively.

OBJECTIVES

The aim of this study was to compare 3 different VDD treatment strategies for use before bariatric surgery and compare serum vitamin D levels after 7 weeks.

SETTINGS

University hospital, Isfahan, Iran.

METHODS

This was a single-blinded, randomized clinical trial on 100 patients who were referred for bariatric surgery from 2016 to 2018. Vitamin D (VitD) level was checked before surgery for the patients included in the study, if their VitD level was <30 ng/mL. We rechecked their serum VitD in the 8^th week, after 7 weeks of treatment. The participants were randomly allocated into 3 groups: 33 patients were treated with 50,000 units VitD₃ capsules every week for 7 weeks; 33 patients were treated with a single dose of 300,000 units VitD₃ ampoule; and 34 patients were treated with a combination of a half of the injection dose, followed by the oral capsule for 4 weeks.

RESULTS

No case was lost during the follow-up time. No significant differences were found among the 3 groups in terms of their age (P = .654), body mass index (P = .434), sex (P = .799), initial 25(OH) VitD level (P = .273), and history of supplement use (P = .45). Mean serum VitD levels were 15.21, 13.16, and 13.37 ng/mL, respectively, before the surgery and reached 32.91, 24.74, and 29.49 ng/mL after 7 weeks of treatment in oral, injection, and combined groups, respectively. Finally, the 7-week oral treatment option had significantly higher levels of VitD (P value = .034).

CONCLUSION

VDD treatment with 50,000 units VitD₃ capsule every week for 7 weeks before bariatric surgery yields a higher level of VitD. Based on our findings, injectable supplements are not recommended for VDD treatment.

Vitamin D and the nervous system

Objective: to summarise the activities that Vitamin D (VD) carries out in the brain and to clarify the potential role of VD in neurological diseases. Methods: a literature research has been performed in Pubmed using the following keywords: 'Vitamin D', 'nervous system', 'brain'. Results: the studies reviewed show that VD contributes to cerebral activity in both embryonic and adult brain, helping the connectivity of neural circuits responsible for locomotor, emotional and reward-dependent behavior. Low VD serum levels have been found in patients affected by Alzheimer Disease, Parkinson Disease, Multiple Sclerosis, Autism Spectrum Disorders, Sleep Disorders and Schizophrenia. Discussion: findings are controversial and should be interpreted with caution, since most of the studies performed have observational study set and few interventional studies are available, producing conflicting results. Overall, it can be stated that the potential role of Vitamin D in neurological diseases is mostly unclear and further randomised controlled trials are needed to understand better whether Vitamin D supplementation treatment can be useful in brain disorders.

Cholecalciferol (Vitamin D3) Reduces Rat Neuropathic Pain by Modulating Opioid Signaling

The impact of vitamin D on sensory function, including pain processing, has been receiving increasing attention. Indeed, vitamin D deficiency is associated with various chronic pain conditions, and several lines of evidence indicate that vitamin D supplementation may trigger pain relief. However, the underlying mechanisms of action remain poorly understood. We used inflammatory and non-inflammatory rat models of chronic pain to evaluate the benefits of vitamin D₃ (cholecalciferol) on pain symptoms. We found that cholecalciferol supplementation improved mechanical nociceptive thresholds in monoarthritic animals and reduced mechanical hyperalgesia and cold allodynia in a model of mononeuropathy. Transcriptomic analysis of cerebrum, dorsal root ganglia, and spinal cord tissues indicate that cholecalciferol supplementation induces a massive gene dysregulation which, in the cerebrum, is associated with opioid signaling (23 genes), nociception (14), and allodynia (8), and, in the dorsal root ganglia, with axonal guidance (37 genes) and nociception (17). Among the identified cerebral dysregulated nociception-, allodynia-, and opioid-associated genes, 21 can be associated with vitamin D metabolism. However, it appears that their expression is modulated by intermediate regulators such as diverse protein kinases and not, as expected, by the vitamin D receptor. Overall, several genes-Oxt, Pdyn, Penk, Pomc, Pth, Tac1, and Tgfb1-encoding for peptides/hormones stand out as top candidates to explain the therapeutic benefit of vitamin D₃ supplementation. Further studies are now warranted to detail the precise mechanisms of action but also the most favorable doses and time windows for pain relief.

Role of CYP1A1, ABCG2, CYP24A1 and VDR gene polymorphisms on the evaluation of cardiac iron overload in thalassaemia patients

OBJECTIVES

Iron-burden-induced arrhythmia and heart failure are among the leading causes of morbidity and mortality in β-thalassaemia major patients. T2* cardiac magnetic resonance remains the only reliable noninvasive method for the heart iron excess assessment. We explored the role of single nucleotide polymorphisms involved in vitamin D metabolism, transport and activity and in deferasirox (DFX) metabolism on cardiac iron burden.

PATIENTS AND METHODS

One hundred and five β-thalassaemia patients, treated with DFX, were enrolled in the present study. Drug plasma Ctrough was measured by a high-performance liquid chromatography-ultraviolet method. Allelic discrimination was carried out using the real-time PCR.

RESULTS

CYP1A1*1189 CC, ABCG2 421 GA, CYP24A1 8620 GG and VDR TaqI CC single nucleotide polymorphisms influenced T2* values. Age, serum ferritin, ABCG2 421 GA, ABCG2 1194 +928 TC/CC, CYP24A1 22776 TT and VDR TaqI TC/CC were retained in linear regression model.

CONCLUSION

Our results suggested, for the first time, the role of DFX and vitamin D pharmacogenetics on cardiac iron overload.

TGF-β1 Impairs Vitamin D-Induced and Constitutive Airway Epithelial Host Defense Mechanisms

Airway epithelium is an important site for local vitamin D (VD) metabolism; this can be negatively affected by inflammatory mediators. VD is an important regulator of respiratory host defense, for example, by increasing the expression of hCAP18/LL-37. TGF-β1 is increased in chronic obstructive pulmonary disease (COPD), and known to decrease the expression of constitutive host defense mediators such as secretory leukocyte protease inhibitor (SLPI) and polymeric immunoglobulin receptor (pIgR). VD has been shown to affect TGF-β1-signaling by inhibiting TGF-β1-induced epithelial-to-mesenchymal transition. However, interactions between VD and TGF-β1, relevant for the understanding host defense in COPD, are incompletely understood. Therefore, the aim of the present study was to investigate the combined effects of VD and TGF-β1 on airway epithelial cell host defense mechanisms. Exposure to TGF-β1 reduced both baseline and VD-induced expression of hCAP18/LL-37, partly by increasing the expression of the VD-degrading enzyme CYP24A1. TGF-β1 alone decreased the number of secretory club and goblet cells and reduced the expression of constitutive host defense mediators SLPI, s/lPLUNC and pIgR, effects that were not modulated by VD. These results suggest that TGF-β1 may decrease the respiratory host defense both directly by reducing the expression of host defense mediators, and indirectly by affecting VD-mediated effects such as expression of hCAP18/LL-37.

Transcriptomic Response to 1,25-Dihydroxyvitamin D in Human Fibroblasts with or without a Functional Vitamin D Receptor (VDR): Novel Target Genes and Insights into VDR Basal Transcriptional Activity

The vitamin D receptor (VDR) mediates vitamin D actions beyond bone health. While VDR activation by 1,25-dihydroxyvitamin D (1,25D) leads to robust transcriptional regulation, less is known about VDR actions in the absence of 1,25D. We analyzed the transcriptomic response to 1,25D in fibroblasts bearing a severe homozygous hereditary vitamin D resistant rickets-related p.Arg30* VDR mutation (MUT) and in control fibroblasts (CO). Roughly 4.5% of the transcriptome was regulated by 1,25D in CO fibroblasts, while MUT cells without a functional VDR were insensitive to 1,25D. Novel VDR target genes identified in human fibroblasts included bone and cartilage factors CILP, EFNB2, and GALNT12. Vehicle-treated CO and MUT fibroblasts had strikingly different transcriptomes, suggesting basal VDR activity. Indeed, oppositional transcriptional effects in basal conditions versus after 1,25D activation were implied for a subset of target genes mostly involved with cell cycle. Cell proliferation assays corroborated this conjectured oppositional basal VDR activity, indicating that precise 1,25D dosage in target tissues might be essential for modulating vitamin D actions in human health.

Clinical and metabolic response to vitamin D plus probiotic in schizophrenia patients

BACKGROUND

This study determined the effects of a novel combination of vitamin D and probiotic on metabolic and clinical symptoms in chronic schizophrenia.

METHODS

This trial was conducted among 60 patients with chronic schizophrenia to receive either 50,000 IU vitamin D3 every 2 weeks plus 8 × 10⁹ CFU/day probiotic (n = 30) or placebo (n = 30) for 12 weeks.

RESULTS

Vitamin D and probiotic co-supplementation was associated with a significant improvement in the general (- 3.1 ± 4.7 vs. + 0.3 ± 3.9, P = 0.004) and total PANSS scores (- 7.4 ± 8.7 vs. -1.9 ± 7.5, P = 0.01). Vitamin D and probiotic co-supplementation also significantly increased total antioxidant capacity (+ 51.1 ± 129.7 vs. -20.7 ± 53.3 mmol/L, P = 0.007), and significantly decreased malondialdehyde (- 0.3 ± 0.9 vs. + 0.2 ± 0.4 μmol/L, P = 0.01) and high sensitivity C-reactive protein levels (- 2.3 ± 3.0 vs. -0.3 ± 0.8 mg/L, P = 0.001) compared with the placebo. Moreover, taking vitamin D plus probiotic significantly reduced fasting plasma glucose (- 7.0 ± 9.9 vs. -0.2 ± 9.9 mg/dL, P = 0.01), insulin concentrations (- 2.7 ± 2.3 vs. + 0.4 ± 2.0 μIU/mL, P < 0.001), homeostasis model of assessment-estimated insulin resistance (- 0.8 ± 0.7 vs. + 0.1 ± 0.7, P < 0.001), triglycerides (- 7.8 ± 25.2 vs. + 10.1 ± 30.8 mg/dL, P = 0.01) and total cholesterol levels (- 4.9 ± 15.0 vs. + 5.9 ± 19.5 mg/dL, P = 0.04) and total-/HDL-cholesterol ratio (- 0.1 ± 0.6 vs. + 0.3 ± 0.8, P = 0.04).

CONCLUSION

Probiotic and vitamin D for 12 weeks to chronic schizophrenia had beneficial effects on the general and total PANSS score, and metabolic profiles.

TRIAL REGISTRATION

This study was retrospectively registered in the Iranian website ( www.irct.ir ) for clinical trials registration ( http://www.irct.ir : IRCT2017072333551N2). 07-31-2017 2.

Effect of Vitamin D Supplement on Mood Status and Inflammation in Vitamin D Deficient Type 2 Diabetic Women with Anxiety: A Randomized Clinical Trial

Background:

Vitamin D plays an important role in nervous health and depression. Vitamin D deficiency and anxiety affect diabetic status. The purpose of this study was to determine the effect of vitamin D supplementation on anxiety, depression, and inflammation in diabetic women with anxiety.

Methods:

In this randomized controlled trial, totally 51 women with type 2 diabetes (T2DM) and vitamin D deficiency were randomly allocated to receive one oral pearl of 50,000 IU vitamin D3 (26 women) or a placebo (25 women) fortnightly for 16 weeks. Anthropometric indices, sun exposure, dietary intake, depression, anxiety, and stress scores and biochemical biomarkers including high sensitivity C-reactive protein (hs-CRP) and interleukin-10 (IL-10) were measured at the baseline and after 16-week supplementation.

Results:

Mean ± SD age of participant was 47.43 ± 9.57 years old. Baseline values were not different between the groups. Anxiety score changes were significantly lower in vitamin D group than the controls (P = 0.001). Within group comparison indicated that depression in supplement group with lower vitamin D levels was significantly reduced. Serum hs-CRP reduced (P = 0.01), while IL-10 concentrations increased (P = 0.04) in the intervention group.

Conclusions:

Vitamin D supplementation can improve mood status and anti-inflammatory biomarkers in female diabetics with anxiety and vitamin D deficiency.

Vitamin D in malaria: more hypotheses than clues

Vitamin D is a secosteroid hormone regulating calcium and phosphate metabolism, immune response and brain development. Low blood 25(OH)D levels have been reported in patients affected by infectious diseases caused by parasites, including malaria. Despite the high effectiveness of antimalarials, malaria is burdened with high morbidity and mortality, and the search for additional therapies is rapidly growing. Furthermore, available preventive measures have proved to be barely effective so far. Finding new prevention and therapy tools is a matter of urgency. Studies on animal models and humans have hypothesized some mechanisms by which the hormone can influence malaria pathogenesis, and the role of Vitamin D supplementation in preventing and treating this disease has been suggested. Few studies on the association between Vitamin D and malaria are available and disagreeing results have been reported. Studies in humans reporting an association between low 25(OH)D circulating levels and Malaria have a small sample size and observational study-set. Randomized controlled trials are needed in order to understand if Vitamin D administration might play a role in preventing and treating malaria.

The Association Between Vitamin D Status, Vitamin D Supplementation, Sunlight Exposure, and Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND This literature review and meta-analysis aimed to determine the association between deficiency of vitamin D, or 25-hydroxyvitamin D, and Parkinson's disease, and whether vitamin D from supplements and sunlight improves the symptoms of Parkinson's disease. MATERIAL AND METHODS A literature review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Systematic literature review was performed using databases that included the Web of Science, PubMed, the Cochrane Library, and Embase. The Jadad scale (the Oxford quality scoring system) and the Newcastle-Ottawa scale (NOS) were used to evaluate the quality of the studies. RESULTS Eight studies were included in the meta-analysis. Both 25-hydroxyvitamin D insufficiency (<30 ng/mL) (OR, 1.77; 95% CI, 1.29-2.43; P<0.001) and deficiency (<20 ng/mL) (OR, 2.55; 95% CI, 1.98-3.27; P<0.001) were significantly associated with an increased risk of Parkinson's disease when compared with normal controls Sunlight exposure (³15 min/week) was significantly associated with a reduced risk of Parkinson's disease (OR, 0.02; 95% CI, 0.00-0.10; P<0.001). The use of vitamin D supplements was effective in increasing 25-hydroxyvitamin D levels (SMD, 1.79; 95% CI, 1.40-2.18; P<0.001), but had no significant effect on motor function (MD, -1.82; 95% CI, -5.10-1.45; P=0.275) in patients with Parkinson's disease. CONCLUSIONS Insufficiency and deficiency of 25-hydroxyvitamin D and reduced exposure to sunlight were significantly associated with an increased risk of Parkinson's disease. However, vitamin D supplements resulted in no significant benefits in improving motor function for patients with Parkinson's disease.

The effect of vitamin D pathway genes and deferasirox pharmacogenetics on liver iron in thalassaemia major patients

Monitoring and treating iron overload is crucial in transfusion-dependent thalassaemia patients. Liver stiffness measurement by transient elastography and T2* magnetic resonance imaging represent non-invasive ways to evaluate the adequacy of the iron chelation treatment. We explored the role of single nucleotide polymorphisms involved in vitamin D metabolism, transport and activity, and in deferasirox metabolism on liver iron burden parameters. One-hundred and five beta-thalassaemia patients, treated with deferasirox, have been enrolled. Drug plasma C_trough and AUC were measured by a HPLC-UV method. Allelic discrimination was performed by real-time PCR. Age, UGT1A1-364 CT/TT and CYP27B1 -1260 GT/TT positively predicted liver stiffness values. Deferasirox dose and serum ferritin negatively predicted T2* data, whereas age and CYP2D6 1457 GG genotype positively influenced these values. The discoveries of this research may be useful for personalized medicine and the proposed method could be applied in patients with hereditary hemochromatosis and myelodysplastic syndromes.

Lower vitamin D levels are associated with depression in patients with gout

BACKGROUND

Depression is commonly observed among patients with gout. Low levels of vitamin D have been associated with depression in non-gout subjects. We examined the association of vitamin D levels with depression in patients with gout.

METHODS

We conducted a cross-sectional study of 186 gout patients at the Endocrinology Department of First Affiliated Hospital of Jiaxing University. Levels of serum 25-hydroxyvi-tamin D (25(OH)D) were determined using a competitive protein-binding assay. The 17-item Hamilton Depression Scale was used for screening for depressive symptoms. Diagnosis of depression in gout patients was made in accordance with Diagnostic and Statistical Manual of Mental Disorders, fifth edition criteria for depression. Multivariate analysis was performed using logistic regression models.

RESULTS

Thirty-two gout patients (17.2%) were diagnosed as having depression. Patients with depression showed significantly lower 25(OH)D levels as compared to patients without depression (46.4±19.0 vs 57.0±17.3 nmol/L, P<0.001). Significant differences in 25(OH)D quartiles of gout patients were observed between the patients with depression and the patients without depression (P=0.003). In multivariate analyses, serum 25(OH)D levels (≤40.0 nmol/L) were independently associated with depression in patients with gout (OR 3.833, 95% CI 1.406-10.453, P=0.009).

CONCLUSION

Our study demonstrates an important association between serum vitamin D levels and depression in patients with gout.

The Vitamin D Binding Protein and Inflammatory Injury: A Mediator or Sentinel of Tissue Damage?

Neutrophils are the most abundant type of white blood cell in most mammals including humans. The primary role of these cells is host defense against microbes and clearance of tissue debris in order to facilitate wound healing and tissue regeneration. The recruitment of neutrophils from blood into tissues is a key step in this process and is mediated by numerous different chemoattractants. The neutrophil migratory response is essential for host defense and survival, but excessive tissue accumulation of neutrophils is observed in many inflammatory disorders and strongly correlates with disease pathology. The vitamin D binding protein (DBP) is a circulating multifunctional plasma protein that can significantly enhance the chemotactic activity of neutrophil chemoattractants both in vitro and in vivo. Recent in vivo studies using DBP deficient mice showed that DBP plays a larger and more central role during inflammation since it induces selective recruitment of neutrophils, and this cofactor function is not restricted to C5a, as prior in vitro studies indicated, but can enhance chemotaxis to many chemoattractants. DBP also is an extracellular scavenger for actin released from damaged/dead cells and formation of DBP-actin complexes is an immediate host response to tissue injury. Recent in vitro evidence indicates that DBP bound to G-actin, and not free DBP, functions as an indirect but essential cofactor for neutrophil migration. DBP-actin complexes always will be formed regardless of what initiated an inflammation, since release of actin from damaged cells is a common feature in all types of injury and DBP is abundant and ubiquitous in all extracellular fluids. Indeed, these complexes have been detected in blood and tissue fluids from both humans and experimental animals following various forms of injury. The published data strongly supports the premise that DBP-actin complexes are the functional neutrophil chemotactic cofactor that enhances neutrophil chemotaxis in vitro and augments neutrophilic inflammation in vivo. This review will assess the fundamental role of DBP in neutrophilic inflammation and injury.

Lack of Vitamin D Receptor Leads to Hyperfunction of Claudin-2 in Intestinal Inflammatory Responses

BACKGROUND

Vitamin D3 and vitamin D receptor (VDR) are involved in the pathogenesis of inflammatory bowel disease (IBD) and bacterial infection. Claudin-2 is a junction protein that mediates paracellular water transport in epithelia. Elevation of Claudin-2 is associated with active IBD. However, VDR involved in epithelial junctions under inflammation and infection remains largely unknown. We investigated the mechanisms on how VDR and Claudin-2 are related in inflamed states.

METHODS

Using cultured VDR-/- enteroids, human intestinal epithelial cells, VDR-/- mice with Salmonella- or DSS-colitis, and human IBD samples, we investigated the mechanisms how VDR and Claudin-2 are related in inflamed states.

RESULTS

After Salmonella infection had taken place, we observed significantly enhanced Claudin-2 and an increased bacterial invasion and translocation. A lack of VDR regulation led to a robust increase of Claudin-2 at the mRNA and protein levels post-infection. In DSS-treated VDR-/- mice, Claudin-2 was significantly increased. Location and quantification of Claudin-2 protein in the mouse colons treated with DSS also confirmed these results. Inflammatory cytokines were significantly higher in the serum and mRNA levels in intestine, which are known to increase Claudin-2. Furthermore, in inflamed intestine of ulcerative colitis patients, VDR expression was low and Claudin-2 was enhanced. Mechanistically, we identified the enhanced Claudin-2 promoter activity through the binding sites of NF-κB and STAT in inflamed VDR-/- cells.

CONCLUSIONS

Our studies have identified a new role for intestinal epithelial VDR in regulating barrier functions in the context of infection and inflammation.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in the Era of the Human Microbiome: Persistent Pathogens Drive Chronic Symptoms by Interfering With Host Metabolism, Gene Expression, and Immunity

The illness ME/CFS has been repeatedly tied to infectious agents such as Epstein Barr Virus. Expanding research on the human microbiome now allows ME/CFS-associated pathogens to be studied as interacting members of human microbiome communities. Humans harbor these vast ecosystems of bacteria, viruses and fungi in nearly all tissue and blood. Most well-studied inflammatory conditions are tied to dysbiosis or imbalance of the human microbiome. While gut microbiome dysbiosis has been identified in ME/CFS, microbes and viruses outside the gut can also contribute to the illness. Pathobionts, and their associated proteins/metabolites, often control human metabolism and gene expression in a manner that pushes the body toward a state of illness. Intracellular pathogens, including many associated with ME/CFS, drive microbiome dysbiosis by directly interfering with human transcription, translation, and DNA repair processes. Molecular mimicry between host and pathogen proteins/metabolites further complicates this interference. Other human pathogens disable mitochondria or dysregulate host nervous system signaling. Antibodies and/or clonal T cells identified in patients with ME/CFS are likely activated in response to these persistent microbiome pathogens. Different human pathogens have evolved similar survival mechanisms to disable the host immune response and host metabolic pathways. The metabolic dysfunction driven by these organisms can result in similar clusters of inflammatory symptoms. ME/CFS may be driven by this pathogen-induced dysfunction, with the nature of dysbiosis and symptom presentation varying based on a patient's unique infectious and environmental history. Under such conditions, patients would benefit from treatments that support the human immune system in an effort to reverse the infectious disease process.

No Association between Polymorphisms of Vitamin D and Oxytocin Receptor Genes and Autistic Spectrum Disorder in a Sample of Turkish Children

Objective

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in social skills and communication with repetitive behaviors. Etiology is still unclear although it is thought to develop with interaction of genes and environmental factors. Oxytocin has extensive effects on intrauterine brain development. Vitamin D, affects neural development and differentiation and contributes to the regulation of around 900 genes including oxytocin receptor gene. In the present study, the contribution of D vitamin receptor and oxytocin receptor gene polymorphisms in the development of ASD in Turkish community was investigated. To our knowledge, this is the first study examining these two associated genes together in the literature.

Methods

Eighty-five patients diagnosed with ASD according to DSM-5 who were referred to outpatient clinics of Child and Adolescent Psychiatry of Başkent University and Mersin University and 52 healthy, age and gender-matched controls were included in the present study. Vitamin D receptor gene rs731236 (Taq1), rs2228570 (Fok1), rs1544410 (Bsm1), rs7975232 (Apa1) polymorphisms and oxytocin receptor gene rs1042778 and rs2268493 polymorphisms were investigated using real time polymerase chain reaction method.

Results

No significant difference between groups in terms of distribution of genotype and alleles in each of polymorphisms for these genes could be found.

Conclusion

Knowledge of genes and polymorphisms associated with the development of ASD may be beneficial for early diagnosis and future treatment. Further studies with larger populations are required to demonstrate molecular pathways which may play part in the development of ASD in Turkey.