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Follicular mucinosis (FM) is a rare inflammatory disorder histologically characterized by mucin deposition in the follicular epithelium. There is no standard therapy for FM and several treatments have been described in the literature. We present the case of a 59 year-old female affected by a recalcitrant FM with diffuse scalp alopecia, in which complete clinical remission was achieved after a combination of topical tacalcitol and photodynamic therapy.

Numerous in vitro and in vivo studies have demonstrated that calcitriol [1,25(OH)2D3] and different vitamin D analogs possess antineoplastic activity, regulating proliferation, differentiation and apoptosis, as well as angiogenesis. Vitamin D compounds have been shown to exert synergistic effects when used in combination with different agents used in anticancer therapies in different cancer models. The aim of this study was to evaluate the mechanisms of the cooperation of the vitamin D compounds [1,24(OH)2D3 (PRI-2191) and 1,25(OH)2D3] with tyrosine kinase inhibitors (imatinib and sunitinib) together with cytostatics (cisplatin and docetaxel) in an A549 non-small cell lung cancer model. The cytotoxic effects of the test compounds used in different combinations were evaluated on A549 lung cancer cells, as well as on human lung microvascular endothelial cells (HLMECs). The effects of such combinations on the cell cycle and cell death were also determined. In addition, changes in the expression of proteins involved in cell cycle regulation, angiogenesis and the action of vitamin D were analyzed. Moreover, the effects of 1,24(OH)2D3 on the anticancer activity of sunitinib and sunitinib in combination with docetaxel were examined in an A549 lung cancer model in vivo. Experiments aiming at evaluating the cytotoxicity of the combinations of the test agents revealed that imatinib and sunitinib together with cisplatin or docetaxel exerted potent anti-proliferative effects in vitro on A549 lung cancer cells and in HLMECs; however, 1,24(OH)2D3 and 1,25(OH)2D3 enhanced the cytotoxic effects only in the endothelial cells. Among the test agents, sunitinib and cisplatin decreased the secretion of vascular endothelial growth factor (VEGF)-A from the A549 lung cancer cells. The decrease in the VEGF-A level following incubation with cisplatin correlated with a higher p53 protein expression, while no such correlation was observed following treatment of the A549 cells with sunitinib. Sunitinib together with docetaxel and 1,24(OH)2D3 exhibited a more potent anticancer activity in the A549 lung cancer model compared to double combinations and to treatment with the compounds alone. The observed anticancer activity may be the result of the influence of the test agents on the process of tumor angiogenesis, for example, through the downregulation of VEGF-A expression in tumor and also on the induction of cell death inside the tumor.

In mouse skin models, mast cells have been shown to express vitamin D receptor (VDR) that can mediate the immunosuppressive effects of ultraviolet B radiation and vitamin D3. However, VDR activation leads to the expression of CYP24A1, a hydroxylase that can inactivate vitamin D3 metabolites. To examine immunoreactivity to VDR and CYP24A1 in mast cells from normal human skin, keratinocyte skin cancers, and disorders of chronic inflammation. Frozen biopsies were collected from the non-lesional and lesional skin of patients with actinic keratosis (AK), Bowen's disease/squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and psoriasis. The expression of VDR and CYP24A1 in tryptase-positive mast cells was analysed using double-staining methods. Less than 0.5% of the mast cells were immunoreactive to VDR in both the non-lesional and lesional skin for all disease groups. In non-lesional skin, only 0.5-2.9% of the mast cells were immunopositive for CYP24A1, however, the percentage of mast cells containing CYP24A1 was significantly increased in lesional skin of AK, SCC, and BCC. In contrast to human skin, LAD2 mast cells cultured from a patient with mast cell sarcoma/leukaemia revealed that about 34% and 6.5% of the cells were immunopositive for VDR and CYP24A1, respectively. Whereas a very small proportion of mast cells in human skin express VDR and CYP24A1, the proportion of mast cells expressing CYP24A1 in keratinocyte skin cancers is increased; the mechanism underlying this is unclear.

Background Vitamin D analogues and NBUVB phototherapy are both well-established modalities of treatment in psoriasis. The objective of this open label, intra individual, left right study was to compare two different Vitamin D analogues, calcipotriol and tacalcitol, in combination with NBUVB phototherapy in chronic stable plaque psoriasis. Methods Thirty patients with stable plaque psoriasis were enrolled for a 12 week clinical trial. The target lesion on left side was treated topically with tacalcitol ointment once daily, while that on the right side was treated with calcipotriol ointment twice daily. NBUVB phototherapy was given thrice weekly. Efficacy was assessed by target plaque scoring. Results Both therapies resulted in statistically significant reduction in erythema, scaling, thickness and target plaque score, seen as early as 2 weeks into therapy. However, Calcipotriol combination led to an earlier clearance of plaques and a lesser relapse rate than tacalcitol combination. The number of treatment sessions and cumulative NBUVB doses were significantly lower in the calcipotriol-treated group. Conclusion Both vitamin D analogues appear to be safe, effective and cosmetically acceptable, calcipotriol being more efficacious, well tolerated with a rapid onset of action and a better maintenance of response. This article is protected by copyright. All rights reserved.

Purpose: Supplementation with dietary forms of vitamin D is commonplace in clinical medicine, elite athletic cohorts and the general population, yet the response of all major vitamin D metabolites to high doses of vitamin D is poorly characterized. We aimed to identify the responses of all major vitamin D metabolites to moderate and high dose supplemental vitamin D3. Methods: A repeated measures design was implemented in which 46 elite professional European athletes were block randomized based on their basal 25[OH]D concentration into two treatment groups. Athletes received either 35,000 or 70,000 IU.week-1 vitamin D3 for 12 weeks and 42 athletes completed the trial. Blood samples were collected over 18 weeks to monitor the response to supplementation and withdrawal from supplementation. Results: Both doses led to significant increases in serum 25[OH]D and 1,25[OH]2D3. 70,000 IU.week-1 also resulted in a significant increase of the metabolite 24,25[OH]¬2D at weeks 6 and 12 that persisted following supplementation withdrawal at week 18, despite a marked decrease in 1,25[OH]2D3. Intact PTH was decreased in both groups by week 6 and remained suppressed throughout the trial. Conclusions: High dose vitamin D3 supplementation (70,000 IU.week-1) may be detrimental for its intended purposes due to increased 24,25[OH]2D production. Rapid withdrawal from high dose supplementation may inhibit the bioactivity of 1,25[OH]2D3 as a consequence of sustained increases in 24,25[OH]2D that persist as 25[OH]D and 1,25[OH]2D concentrations decrease. These data imply that lower doses of vitamin D3 ingested frequently may be most appropriate and gradual withdrawal from supplementation as opposed to rapid withdrawal may be favorable.

WOS: 000392528100001, PubMed: 28115793, Objective. It was examined whether PTH and 25-dihydroxyvitamin D(25(OH)D) levels, together or separately, are indicators of the risk of stroke. Materials and Methods. This prospective study was performed at two centers. In the study, 100 patients diagnosed with acute ischemic stroke and 100 control individuals in the same age range were examined. In addition to neurological examination, cranial imaging, extensive routine blood chemistry, PTH, and 25(OH) D levels were evaluated in all cases. Stroke risk factors were determined. Logistic regression was used for statistical analysis. Results. A total of 60 patients and 79 control individuals were included in the study. Different estimation models were designed in order to examine the relationship between PTH and 25(OH) D levels with stroke. According to modeling results, it was determined that the most effective predictor for risk of stroke was 25(OH) D levels, followed by hypertension and PTH levels, respectively. Conclusion. PTH and 25(OH) D levels together can make important contributions to determination of stroke risk, and further investigations are needed to understand this relationship more fully.

Darier disease (DD) is a rare type of inherited keratinizing disorder with no definitive therapeutic approach. The objective of this study is to provide a detailed literature review of all the available treatment modalities of Darier disease, including those that are both surgical and non surgical, to compare their efficacies and to propose a novel therapeutic approach. A complete search of the literature for all articles describing the different treatments of Darier disease, with no restrictions on patients' ages, gender or nationalities, was performed with the use of PubMed. A total of 68 articles were included in the study: 3 prospective studies, 44 case reports/case series and 21 letters/correspondences/clinical images. The treatments described were topical, oral or physical. Retinoids (isotretinoin, tazarotene and adapalene) and fluorouracil were the two most effective topical treatments. Oral retinoids were the most effective oral therapy and were prescribed in the cases of generalized Darier disease. For localized and resistant skin lesions, physical therapies including surgical excision, dermabrasion and CO2 laser ablation were the first line choices. Limitations of this article include the inability to verify the accuracy of the published data, the relatively small sample size, the absence of randomized controlled clinical trials and possible unidentified confounding factors in various studies. In every therapeutic approach to Darier disease, consideration of patient comorbidities, disease distribution, severity and treatment accessibility is essential. Large and randomized clinical trials are necessary for the comparison of the efficacy and the safety of all the treatments of Darier disease and settling a consensus for management.

1,25-Dihydroxycholecalciferol, the hormonally active vitamin D3 metabolite, is known to exhibit therapeutic effects against breast cancer, mainly by lowering the expression of estrogen receptors and aromatase activity. Previously, the safety of the vitamin D active metabolite (24R)-1,24-dihydroxycholecalciferol (PRI-2191) and 1,25(OH)2D3 analog PRI-2205 was tested, and the in vitro activity of these analogs against different cancer cell lines was studied. We determined the effect of the two vitamin D compounds on anastrozole (An) activity against breast cancer based on antiproliferative activity, ELISA, flow cytometry, enzyme inhibition potency, PCR, and xenograft study. Both the vitamin D active metabolite and synthetic analog regulated the growth of not only estrogen receptor-positive cells (T47D and MCF-7, in vitro and in vivo), but also hormone-independent cancer cells such as SKBR-3 (HER-2-positive) and MDA-MB-231 (triple-negative), despite their relatively low VDR expression. Combined with An, PRI-2191 and PRI-2205 significantly inhibited the tumor growth of MCF-7 cells. Potentiation of the antitumor activity in combined treatment of MCF-7 tumor-bearing mice is related to the reduced activity of aromatase by both An (enzyme inhibition) and vitamin D compounds (switched off/decreased aromatase gene expression, decreased expression of other genes related to estrogen signaling) and by regulation of the expression of the estrogen receptor ERα and VDR.

The disorder of X-linked hypophosphatemia (XLH), results in the supressed renal production of active 1α,25-dihydroxyvitamin D (1,25(OH)2D) due to elevated fibroblast growth factor-23 (FGF23) levels. While adequate 25(OH)D levels are generally associated with improved mineralisation of the skeleton independent of circulating 1,25(OH)2D levels, it is unclear whether raising 25(OH)D to sufficiently high levels through dietary vitamin D3 administration contributes to improving bone mineralisation in the murine homolog for XLH, Hyp mice. Three-week-old male Hyp mice were fed one of four diets containing either 1000 IU (C) or 20,000 IU (D) vitamin D3/kg diet with either 0.35% phosphate or 1.25% phosphate (P) until 12 weeks of age (n = 12/group). When compared to C-fed mice, D-fed mice significantly elevated serum 25(OH)D levels to 72.8 ± 4.9 nmol/L (2-fold, p < 0.001) and increased both cortical bone mineral density (15%, p < 0.01), and vertebral trabecular BV/TV% (80%, p < 0.001), despite persistent hypophosphatemia and normocalcemia. The increase in bone volume was associated with improved Tb.Th (12%, p < 0.01) and Tb.N (63%, p < 0.001). Unlike with D-diet, P-fed mice resulted in increased femoral (15%, p < 0.001) and vertebral (12%, p < 0.001) length, and a 34% increase in vertebral trabecular BV/TV% when compared to control fed animals (p < 0.001). However, the addition of the high P diet to the high D diet did not result in additive effects on bone mineralisation when compared to the effects of D diet alone, despite serum 25(OH)D levels elevated to 118.8 ± 8.6 nmol/L. In D-fed mice, the increase in bone mineral density and volume was associated with reduced osteoid volume, reduced ObS/BS, and a trend for reduced serum PTH levels, suggesting reduced bone turnover in these animals. Thus, elevating serum 25(OH)D levels independently improves bone mineralisation in Hyp mice without causing hypercalcemia, suggesting that further studies are required in XLH patients to establish the role of increasing 25(OH)D levels in improving bone mineralisation. Refereed/Peer-reviewed

SummaryBackground Phototherapy especially NB-UVB has been considered as mainstay of therapy in non-segmental vitiligo (generalized type). Topical tacalcitol has also been claimed to be effective, either as monotherapy or as combination therapy. Purpose Comparison of clinical efficacy and safety of NBUVB in combination with topical tacalcitol versus NBUVB alone in vitiligo. Material & methods Thirty patients with symmetrical vitiliginous lesions were enrolled for 24 weeks. Patients were instructed to apply tacalcitol ointment on right side of body once daily. In addition, the whole body was irradiated with NBUVB thrice weekly. All the patients were examined and lesional photography was done. Patients were also followed-up for 6 months post-treatment. Results Our study resulted in two key findings- (1) There was statistically significant difference in mean percentage of re-pigmentation at 8, 16 and 24 weeks between combination therapy and NBUVB. (2) The mean cumulative dose and number of treatment sessions for initial re-pigmentation were significantly lower with combination therapy. No serious adverse effects were observed during the study period. Conclusion Topical tacalcitol potentiates efficacy of NBUVB as it enhances extent of pigmentation, decrease time to re-pigmentation and lowers the cumulative doses of NBUVB, thereby leading to greater patient satisfaction and improved compliance. This article is protected by copyright. All rights reserved.

There is evidence of a role of vitamin D in cognitive functioning, but little is known about the type of functions involved. To describe vitamin D status in a population of old patients with memory complaints and its relationships with cognitive performance and white matter lesions. A retrospective single-centre observational study from the medical records of 244 patients who had a measurement of serum 25OHD together with a battery of neuropsychological tests during a complete geriatric and memory assessment in a day care hospital. The results of the 10 neuropsychological tests considered in this study were analysed as binary variables, opposing patients with results within the highest two tertiles to patients with the worse results or unable to perform the test. Mean age of people included was 80.2 ± 8.1 years and 64% of patients were women. Severe deficiency in vitamin D (25OHD

Background Bi-allelic CYP24A1 mutations can cause idiopathic infantile hypercalcemia (IIH), adult-onset nephrocalcinosis, and possibly bone metabolism disturbances. It is currently unclear if heterozygous carriers experience clinical problems or biochemical abnormalities. Our objective is to gain insight in the biochemical profile and health problems in CYP24A1 heterozygotes. Study design Cross-sectional evaluation of participants. Data of previously reported carriers are reviewed. Setting and participants Outpatient clinic of a tertiary care hospital. Participants were eight family members of an infant with a well-characterized homozygous CYP24A1 mutation c.1186C > T p.(Arg396Trp). Outcomes Serum vitamin D metabolites. Symptoms or biochemical signs of hypercalcemia, hypercalciuria or nephrocalcinosis. Bone health in heterozygous as compared to wild type (WT) subjects. Measurements Genotyping by Sanger sequencing; vitamin D metabolites by liquid chromatography tandem mass spectrometry; renal, calcium and bone markers by biochemical analyses; presence of nephrocalcinosis by renal ultrasound; bone health by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. Results Six participants were heterozygous carriers of the mutation. None of the heterozygous subjects had experienced IIH. One had a documented history of nephrolithiasis, two others had complaints compatible with this diagnosis. No major differences between WT and heterozygous subjects were found regarding bone health, serum or urinary calcium or 25OHD/24,25(OH)2D ratio. Literature reports on three out of 33 heterozygous cases suffering from IIH. In all three, the 25OHD/24,25(OH)2D ratio was highly elevated. Nephrocalcinosis was frequently reported in family members of IIH cases. Limitations Small sample size, lack of a large control group. Conclusions Our and literature data suggest that most heterozygous CYP24A1 mutation carriers have a normal 25OHD/24,25(OH)2D ratio, are usually asymptomatic and have a normal skeletal status but may possibly be at increased risk of nephrocalcinosis. A review of the available literature suggests that an elevated 25OHD/24,25(OH)2D ratio may be associated with symptoms of IHH, irrespective of carrier status.

A novel pathway of vitamin D activation by CYP11A has previously been elucidated. To define the mechanism of action of its major dihydroxy-products, we tested the divergence and overlap between the gene expression profiles of human epidermal keratinocytes treated with either CYP11A1-derived 20,23(OH)2D3 or classical 1,25(OH)2D3. Both secosteroids have significant chemical similarity with the only differences being the positions of the hydroxyl groups. mRNA was isolated and examined by microarray analysis using Illumina&rsquo, s HumanWG-6 chip/arrays and subsequent bioinformatics analyses. Marked differences in the up- and downregulated genes were observed between 1,25(OH)2D3- and 20,23(OH)2D3-treated cells. Hierarchical clustering identified both distinct, opposite and common (overlapping) gene expression patterns. CYP24A1 was a common gene strongly activated by both compounds, a finding confirmed by qPCR. Ingenuity pathway analysis identified VDR/RXR signaling as the top canonical pathway induced by 1,25(OH)2D3. In contrast, the top canonical pathway induced by 20,23(OH)2D3 was AhR, with VDR/RXR being the second nuclear receptor signaling pathway identified. QPCR analyses validated the former finding by revealing that 20,23(OH)2D3 stimulated CYP1A1 and CYP1B1 gene expression, effects located downstream of AhR. Similar stimulation was observed with 20(OH)D3, the precursor to 20,23(OH)2D3, as well as with its downstream metabolite, 17,20,23(OH)3D3. Using a Human AhR Reporter Assay System we showed marked activation of AhR activity by 20,23(OH)2D3, with weaker stimulation by 20(OH)D3. Finally, molecular modeling using an AhR LBD model predicted vitamin D3 hydroxyderivatives to be good ligands for this receptor. Thus, our microarray, qPCR, functional studies and molecular modeling indicate that AhR is the major receptor target for 20,23(OH)2D3, opening an exciting area of investigation on the interaction of different vitamin D3-hydroxyderivatives with AhR and the subsequent downstream activation of signal transduction pathways in a cell-type-dependent manner.

Vitamin D plays an important role in maintaining skeletal development and bone homeostasis. Although vitamin D has been extensively researched, the direct effect of 1,25(OH)

Macrophages are highly plastic cells. Depending on stimulation, macrophages rapidly polarize to functionally distinct phenotypes that are involved in the pathogenesis of inflammatory bowel disease (IBD). 1,25‑Dihydroxyvitamin D (1,25(OH)2D3) has immunomodulatory activity, and 1,25(OH)2D3 deficiency is correlated with autoimmune diseases, especially IBD. This study aimed to explore whether 1,25(OH)2D3 modulates macrophage polarization in inflammation. Peripheral blood mononuclear cells and colitis mice were treated with 1,25(OH)2D3. Macrophages were transfected with siRNA-vitamin D receptor (VDR) or miR-125b mimic or inhibitor, and 1,25(OH)2D3-pretreated colitis mice were injected with a miR-125b agomir. The distribution of macrophage subsets and macrophage subtype characteristics was analyzed. As expected, 1,25(OH)2D3 transformed lipopolysaccharide-induced M1 macrophages to the M2 subset, downregulated tumor necrosis factor-α and interleukin (IL)-6 expression and interferon regulatory factor 5 (IRF5) phosphorylation, and upregulated IL-10, arginase-1, VDR, and IRF4 expression. SiRNA-VDR and miR-125b mimic significantly impaired 1,25(OH)2D3 activity. In colitis mice, 1,25(OH)2D3 pretreatment ameliorated disease activity, converted M1 macrophages to the M2 subtype, suppressed IRF5 phosphorylation, and increased IRF4 expression in lamina propria mononuclear cells (LPMC). miR-125b agomir injections reversed 1,25(OH)2D3 action. Collectively, the results demonstrate that 1,25(OH)2D3 downregulates miR-125b expression and promotes M1 macrophage polarization to the M2 subtype. 1,25(OH)2D3 pretreatment ameliorated colitis by restoring the LPMC macrophage subtype balance.

Vitamin D has immunomodulatory, anti-inflammatory, antioxidant, and anti-fibrotic actions that may impact on the occurrence and outcome of immune-mediated disease. The goals of this review are to describe the nature of these expanded roles, examine the implications of vitamin D deficiency in autoimmune hepatitis, and identify opportunities for future investigation. Abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed. Vitamin D receptors are expressed on the principal cell populations involved in the innate and adaptive immune responses. Macrophages and dendritic cells can produce 1,25-dihydroxyvitamin D within the microenvironment. This active form of vitamin D can inhibit immune cell proliferation, promote an anti-inflammatory cytokine profile, expand regulatory T cells, enhance glucocorticoid actions, increase glutathione production, and inhibit hepatic stellate cells. Vitamin D deficiency has been commonly present in patients with immune-mediated liver and non-liver diseases, and it has been associated with histological severity, advanced hepatic fibrosis, and non-response to conventional glucocorticoid therapy in autoimmune hepatitis. Vitamin D analogues with high potency, low calcemic effects, and independence from hepatic hydroxylation are possible interventions. In conclusion, vitamin D has properties that could ameliorate immune-mediated disease, and vitamin D deficiency has been a common finding in immune-mediated liver and non-liver diseases, including autoimmune hepatitis. Loss of vitamin D-dependent homeostatic mechanisms may promote disease progression. Vitamin D analogues that are independent of hepatic hydroxylation constitute an investigational opportunity to supplement current management of autoimmune hepatitis.

Three 23-hydroxylated vitamin D

In our previous study, calcitriol and its analogs PRI-2191 and PRI-2205 stimulated 4T1 mouse mammary gland cancer metastasis. Therefore, we aimed to analyze the inflammatory response in 4T1-bearing mice treated with these compounds. Gene expression analysis of the splenocytes and regional lymph nodes demonstrated prevalence of the T helper lymphocytes (Th2) response with an increased activity of regulatory T (Treg) lymphocytes in mice treated with these compounds. We also observed an increased number of mature granulocytes and B lymphocytes and a decreased number of TCD4+, TCD4+CD25+, and TCD8+, as well as natural killer (NK) CD335+, cells in the blood of mice treated with calcitriol and its analogs. Among the splenocytes, we observed a significant decrease in NK CD335+ cells and an increase in TCD8+ cells. Calcitriol and its analogs decreased the levels of interleukin (IL)-1&beta, and IL-10 and increased the level of interferon gamma (IFN-&gamma, ) in the plasma. In the tumor tissue, they caused an increase in the level of IL-10. Gene expression analysis of lung tissue demonstrated an increased level of osteopontin (Spp1) and transforming growth factor &beta, (TGF-&beta, ) mRNA. The expression of Spp1 was also elevated in lymph nodes. Calcitriol and its analogs caused prevalence of tumor-conducive changes in the immune system of 4T1 tumor-bearing mice, despite the induction of some tumor-disadvantageous effects.

MiR-125b belongs to the class of microRNAs, which are short endogenous non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. Recently, it was reported that miR-125b was found to promote migration and invasion of MCF-7 cells and was involved in chemotherapeutic resistance. Decreasing miR-125b expression would have potential therapeutic significance in preventing dissemination of breast cancer cells. The objective of this study was to evaluate miR-125b expression levels in MCF-7 cells following treatment with 1,25-dihydroxyvitamin D3 (calcitriol) and 1,24-dihydroxyvitamin D3 (tacalcitol), active metabolite and synthetic analog of vitamin D3, respectively. We found that treatment with both calcitriol and tacalcitol caused a decrease in miR-125b expression. In addition, treatment with calcitriol and tacalcitol resulted in an increase in the level of pro-apoptotic BAK1 protein encoded by the target gene of miR-125b. We are discussing the putative mechanism of inhibition of the miR-125b expression by vitamin D receptor (VDR) agonists and we suggest that calcitriol and tacalcitol may be used as a miR-125b inhibitor in breast cancer cells expressing VDR.

This study was supported by the National Science Center granted on the basis of the decision number DEC‑2013/11/B/NZ5/00162. This study was also supported by Wroclaw Center of Biotechnology within a program - The Leading National Research Center (KNOW) for years 2014‑2018; Low vitamin D status is considered as a risk factor for breast cancer and has prognostic significance. Furthermore, vitamin D deficiency increases after adjuvant cancer therapy, which alters bone metabolism increasing the risk of osteoporosis. It is now postulated that vitamin D supplementation in breast cancer treatment delays the recurrence of cancer thereby extending survival. We evaluated the impact of calcitriol and its low-calcemic analogs, PRI2191 and PRI2205, on the tumor growth, angiogenesis, and metastasis of 4T1 mouse mammary gland cancer. Gene expression analysis related to cancer invasion/metastasis, realtime PCR, ELISA, western blotting, and histochemical studies were performed. In vitro studies were conducted to compare the effects of calcitriol and its analogs on 4T1 and 67NR cell proliferation and expression of selected proteins. Calcitriol and its analogs increased lung metastasis without influencing the growth of primary tumor. The levels of plasma 17beta-estradiol and transforming growth factor beta (TGFbeta) were found to be elevated after treatment. Moreover, the results showed that tumor blood perfusion improved and osteopontin (OPN) levels increased, whereas vascular endothelial growth factor (VEGF) and TGFbeta levels decreased in tumors from treated mice. All the studied treatments resulted in increased collagen content in the tumor tissue in the early step of tumor progression, and calcitriol caused an increase in collagen content in lung tissue. In addition, in vitro proliferation of 4T1 tumor cells was not found to be affected by calcitriol or its analogs in contrast to non-metastatic 67NR cells. Calcitriol and its analogs enhanced the metastatic potential of 4T1 mouse mammary gland cancer by inducing the secretion of OPN probably via host cells. In addition, OPN tumor overexpression prevailed over the decreasing tumor TGFbeta level and blood vessel normalization via tumor VEGF deprivation induced by calcitriol and its analogs. Moreover, the increased plasma TGFbeta and 17beta-estradiol levels contributed to the facilitation of metastatic process

Androgens act in concert with vitamin D to influence reabsorption of calcium. However, it is unclear whether androgens directly regulate vitamin D homeostasis or control other cellular events that are related to vitamin D metabolism. To examine whether the expression of vitamin D-related genes in mouse kidney is driven by androgens or androgen-dependent effects, the androgen receptor and other sex steroid receptors were monitored in orchidectomized mice treated with 5α-dihydrotestosterone (DHT). Our results revealed that exposing orchidectomized mice to DHT inhibited the expression of progesterone receptor (Pgr) with or without estrogen receptor α expression, the latter was confirmed by ER-positive (MCF7 and T47D) or -negative (PCT) cells analysis. The loss of Pgr in turn decreased the expression of renal 24-hydroxylase

This study was aimed to determine whether hypocalcemic analogs of active forms of vitamins D modulate expression of genes related to stem-like phenotype in colon cancer cell lines HT-29 and HCT-116 undergoing renewal after the treatment with 5-fluorouracil (5-FU). Both lines express vitamin D receptor, but differ in differentiation stage and vitamin D sensitivity. Cells that resisted the 5-FU exposure were treated with synthetic analog of 1,25-dihydroxyvitamin D2 (PRI-1906) and analogs of 1,25-dihydroxyvitamin D3 (PRI-2191 and PRI-2205). Proliferative activity was more profoundly affected by vitamin D analogs in HT-29/5-FU than in HCT-116/5-FU cells. In HT-29/5-FU cells, analogs PRI-1906 and PRI-2191 downregulated the expression of genes related to survival, re-growth, and invasiveness during renewal, while PRI-2205 increased expression of genes related to differentiation only. In HCT-116/5-FU cells, PRI-2191 decreased the expression of stemness- and angiogenesis-related genes, whereas PRI-1906 augmented their expression. The effects in HCT-116/5-FU cells were observed at higher concentrations of the analogs than those used for HT-29/5-FU cells. Out of the series of analogs studied, PRI-2191 might be used to counteract the renewal of both moderately and poorly differentiated cancer cells following conventional treatment.

CYP11A1 hydroxylates vitamin D3 producing 20S-hydroxyvitamin D3 [20(OH)D3] and 20S,23-dihydroxyvitamin D3 [20,23(OH)2D3] as the major and most characterized metabolites. Both display immuno-regulatory and anti-cancer properties while being non-calcemic. A previous study indicated 20(OH)D3 can be metabolized by rat CYP24A1 to products including 20S,24-dihydroxyvitamin D3 [20,24(OH)2D3] and 20S,25-dihydroxyvitamin D3, with both producing greater inhibition of melanoma colony formation than 20(OH)D3. The aim of this study was to characterize the ability of rat and human CYP24A1 to metabolize 20(OH)D3 and 20,23(OH)2D3. Both isoforms metabolized 20(OH)D3 to the same dihydroxyvitamin D species with no secondary metabolites being observed. Hydroxylation at C24 produced both enantiomers of 20,24(OH)2D3. For rat CYP24A1 the preferred initial site of hydroxylation was at C24 whereas the human enzyme preferred C25. 20,23(OH)2D3 was initially metabolized to 20S,23,24-trihydroxyvitamin D3 and 20S,23,25-trihydroxyvitamin D3 by rat and human CYP24A1 as determined by NMR, with both isoforms showing a preference for initial hydroxylation at C25. CYP24A1 was able to further oxidize these metabolites in a series of reactions which included the cleavage of C23-C24 bond, as indicated by high resolution mass spectrometry of the products, analogous to the catabolism of 1,25(OH)2D3 via the C24-oxidation pathway. Similar catalytic efficiencies were observed for the metabolism of 20(OH)D3 and 20,23(OH)2D3 by human CYP24A1 and were lower than for the metabolism of 1,25(OH)2D3. We conclude that rat and human CYP24A1 metabolizes 20(OH)D3 producing only dihydroxyvitamin D3 species as products which retain biological activity, whereas 20,23(OH)2D3 undergoes multiple oxidations which include cleavage of the side chain.

Vitamin D and its derivatives have modulatory effects in immunological and inflammatory responses. Such properties suggest that they might have an impact on chronic inflammatory airway diseases, including nasal polyposis. The aim of this study was to understand the role of vitamin D in chronic rhinosinusitis with nasal polyps (CRSwNP) by investigating its effect on the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9 in nasal polyp-derived fibroblasts. Two primary fibroblast cultures were established from nasal polyp tissues obtained during surgery. The nasal polyp-derived fibroblasts were stimulated with tumor necrosis factor-α (TNF-α; 10 ng/mL) for 24 hours, followed by replacement with media alone or with vitamin D derivatives (calcitriol or tacalcitol; 10μM) and incubated for another 24 hours. After the treatments, the levels of MMP-2 and MMP-9 secreted were evaluated by both enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. ELISA results revealed that TNF-α could substantially stimulate the secretion of MMP-2 (p

Vitamin D3 (VD3) analogues-containing ointments are known to occasionally cause hypercalcemia in psoriasis patients, and the frequency of hypercalcemia is suggested to vary based on the VD3 analogue used. In this study, to address the differences in calcemic effects of VD3-containing ointments, the calcemic effects of marketed VD3-containing ointments, including calcipotriol (Cal), maxacalcitol (Max), tacalcitol (Tac), calcipotriol/betamethasone dipropionate (Cal/BDP) and maxacalcitol/betamethasone butyrate propionate (Max/BBP) ointments, were evaluated in a rat model of imiquimod-induced dermatitis. The topical application of Tac, Max and Max/BBP ointments, but not Cal and Cal/BDP ointments, to the imiquimod-induced skin lesions significantly induced an increase in the serum calcium level compared with the vaseline-treated group. Calcemic effect of VD3 analogues in rats treated with VD3-containing ointments was analyzed by evaluating the expression of vitamin D receptor target genes, such as Cyp24a1, Trpv5 and CalbindinD28k, in the intestine and kidney. Real-time reverse transcription PCR (RT-PCR) analysis showed that the renal and intestinal Cyp24a1 expressions in the Cal- and Cal/BDP-treated groups were significantly lower than those in the Tac-, Max- and Max/BBP-treated groups, suggesting that systemic exposure of VD3 analogues in the Cal- and Cal/BDP-treated groups were lower than those in the other ointment-treated groups. In addition, the renal Trpv5 and CalbindinD28k expressions, calcium-transporting genes, were increased in the Max- and Max/BBP-treated groups compared with the Cal- and Cal/BDP-treated groups. Thus, because of the low systemic exposure of VD3 analogues, Cal and Cal/BDP ointments have lower calcemic effect than the other VD3-containing ointments in rats with psoriasis-like dermatitis.

We evaluated associations of serum 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) levels in a cohort of HIV-infected and HIV-uninfected men at risk for infection in the United States. Stored samples collected between 1999 and 2008 were tested for vitamin D metabolites between 2014 and 2015. Vitamin D deficiency was defined as a serum concentration of 25[OH]D

Cross-complementation studies offer the possibility to overcome limitations imposed by the inherent complexity of multicellular organisms in the study of human diseases, by taking advantage of simpler model organisms like the budding yeast Saccharomyces cerevisiae. This review deals with, (1) the use of S. cerevisiae as a model organism to study human diseases, (2) yeast-based screening systems for the detection of disease modifiers, (3) Hailey–Hailey as an example of a calcium-related disease, and (4) the presentation of a yeast-based model to search for chemical modifiers of Hailey–Hailey disease. The preliminary experimental data presented and discussed here show that it is possible to use yeast as a model system for Hailey–Hailey disease and suggest that in all likelihood, yeast has the potential to reveal candidate drugs for the treatment of this disorder. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau, B. Research in MB's laboratory is funded by the Institut National de la Santé et de la Recherche Médicale (Inserm) and Université de Bretagne Occidentale (UBO). Research in REW's laboratory is funded by the Spanish Ministry of Economy and Competitiveness (BFU2010-21339), the Junta de Andalucía (P08-CTS-04297) and the European Union (FEDER).

In the present study, we evaluated the antitumor effect of two synthetic analogs of vitamin D, namely PRI-2191 [(24R)-1,24-dihydroxyvitamin D3] and PRI-2205 (5,6-trans calcipotriol), in combined human colon HT-29 cancer treatment with 5-fluorouracil (5-FU). Mice bearing HT-29 tumors transplanted subcutaneously or orthotopically were injected with vitamin D analogs and 5-FU in various schedules. A statistically significant inhibition of subcutaneous or orthotopic tumor growth was observed as a result of combined therapy. In HT-29 tumors and in cells from in vitro culture, we observed increased vitamin D receptor (VDR) expression after treatment with either PRI-2205 or 5-FU alone, or in combination. Moreover, PRI-2205 decreased the percentage of cells from intestinal tumors in G2/M and S stages and increased sub-G1. Increased VDR expression was also observed after combined treatment of mice with 5-FU and PRI-2191. Moreover, our docking studies showed that PRI-2205 has stronger affinity for VDR, DBP and CAR/RXR ligand binding domains than PRI-2191. PRI-2191 analog, used with 5-FU, increased the percentage of subcutaneous tumor cells in G0/G1 and decreased the percentage in G2/M, S and sub-G1 populations as compared to 5-FU alone. In in vitro studies, we observed increased expression of p21 and p-ERK1/2 diminution via use of both analogs as compared to use of 5-FU alone. Simultaneously, PRI-2191 antagonizes some pro-apoptotic activities of 5-FU in vitro. However, in spite of these disadvantageous effects in terms of apoptosis, the therapeutic effect expressed as tumor growth retardation by PRI-2191 is significant. Our results suggest that the mechanism of potentiation of 5-FU antitumor action by both analogs is realized via increased p21 expression and decreased p-ERK1/2 level which may lead to diminution of thymidylate synthase expression. Higher binding affinity for VDR, DBP, but also for CAR\RXR ligand binding domain of PRI-2205 may, in part, explain its very low toxicity with sustained anticancer activity.

RORα and RORγ are expressed in human skin cells that produce the noncalcemic 20-hydroxyvitamin D3 [20(OH)D3] and 20,23-dihydroxyvitamin D3 [20,23(OH)2D3]. Chinese hamster ovary (CHO) cells stably expressing a Tet-on RORα or RORγ expression vector and a ROR-responsive element (RORE)-LUC reporter, and a mammalian 2-hybrid model examining the interaction between the ligand binding domain (LBD) of RORα or RORγ with an LBD-interacting LXXLL-peptide, were used to study ROR-antagonist activities. These assays revealed that 20(OH)D3 and 20,23(OH)2D3 function as antagonists of RORα and RORγ. Moreover, 20(OH)D3 inhibited the activation of the promoter of the Bmal1 and G6pase genes, targets of RORα, and 20(OH)D3 and 20,23(OH)2D3 inhibited Il17 promoter activity in Jurkat cells overexpressing RORα or RORγ. Molecular modeling using crystal structures of the LBDs of RORα and RORγ revealed docking scores for 20(OH)D3, 20,23(OH)2D3 and 1,25(OH)2D3 similar to those of the natural ligands, predicting good binding to the receptor. Notably, 20(OH)D3, 20,23(OH)2D3, and 1,25(OH)2D3 inhibited RORE-mediated activation of a reporter in keratinocytes and melanoma cells and inhibited IL-17 production by immune cells. Our study identifies a novel signaling pathway, in which 20(OH)D3 and 20,23(OH)2D3 act as antagonists or inverse agonists of RORα and RORγ, that opens new possibilities for local (skin) or systemic regulation.—Slominski, A. T., Kim, T.-K., Takeda, Y., Janjetovic, Z., Broz˙yna, A. A., Skobowiat, C., Wang, J., Postlethwaite, A., Li, W., Tuckey, R. C., Jetten, A. M. RORα and ROR γ are expressed in human skin and serve as receptors for endogenously produced noncalcemic 20-hydroxy- and 20,23-dihydroxyvitamin D.

Eosinophils appear to be central inflammatory cells in the pathogenesis of rhinosinusitis with nasal polyps (NP). One of the most predominantly recognized eosinophil chemoattractants is RANTES. The aim of this study was to assess the influence of vitamin D (VD) derivates on RANTES expression in the culture of nasal polyp fibroblasts.NP fibroblast cell cultures derived from 16 patients with NP were first stimulated with bacterial LPS and than incubated in increasing concentrations (from 10(-7)M to 10(-4)M) of calcitriol, tacalcitol or budesonide and in combination with one of VD derivate with budesonide in 1:1, 1:3 and 3:1 ratios. Quantitative analysis of RANTES level was conducted in culture supernatants using an ELISA method.The highest calcitriol concentration (10(-4)M) as well as tacalcitol at 10(-5)M and 10(-4)M reduced RANTES production significantly compared to the control (201.1pg/ml, 338.7pg/ml, 211.3pg/ml v 571.78pg/ml; p0.05). Budesonide and calcitriol administered in 1:3 ratio and budesonide and tacalcitol in 1:1 and 1:3 reduced RANTES concentration significantly better than each of the drug used in monotherapy (p0.05). Budesonide and tacalcitol in 1:1 and 1:3 ratios suppressed RANTES production to the lowest level (171.8±97.6pg/ml and 178.7±105.22pg/ml, respectively).Active VD compounds via downregulation of RANTES production exert a potential role as a complementary element in the therapy of chronic rhinosinusitis with NP. Compounds consisting of budesonide and VD derivate have an advantage over both drugs used in monotherapy.

The long-term effects of vitamin D analogues and metabolites on renal function were assessed in 24 patients with and without chronic renal failure. Treatment for periods of 5-45 months did not adversely affect renal function in 10 of 11 patients with stable renal function, although transient hypercalcaemia did cause transient rises in plasma creatinine. Of 13 patients with progressive renal failure before treatment, vitamin D-like compounds or the vehicle used for their administration may have accelerated renal failure in 3 patients independently of changes in plasma calcium or phosphate. Particular difficulties in assessing the effects of vitamin D-like compounds in progressive renal disease are discussed.