Vitamin D Receptor Gene Polymorphisms and Risk of Knee Osteoarthritis: Possible Correlations with TNF-α, Macrophage Migration Inhibitory Factor, and 25-Hydroxycholecalciferol Status

Osteoarthritis (OA) etiology and pathogenesis not yet fully understood. We studied the role of vitamin D receptor single-nucleotide polymorphisms (VDR-SNPs), vitamin D3, serum and synovial macrophage migration inhibitory factor (MIF), and tumor necrosis factor-α (TNF-α) in the development and progression of knee OA (KOA). This study included 205 Egyptian subjects (105 patients with KOA and 100 unrelated, healthy matched subjects selected as controls). The patient group was divided into three groups according to KOA severity (mild, moderate, and severe), with 35 patients in each group. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used for the ApaI and TaqI SNPs. Vitamin D, serum and synovial TNF-α, and MIF assays were performed using ELISA kits. There were significantly lower serum levels of 25-hydroxycholecalciferol with significant increasing TNF-α and MIF levels in relation to disease severity among the cases (all: p˂0.05).Wild homozygous and heterozygous mutant genotypes (GG+GT) and G allele of ApaI demonstrated risk for KOA development, with odds ratio OR = 6.313 (95% confidence interval (CI) 2.074-19.210) and OR = 1.532 (95%CI 1.013-2.317), respectively. Homozygous mutant CC genotype and C allele of TaqI could be considered a risk factor associated with KOA development, with OR = 2.667 (95%CI 1.270-5.601) and OR = 0.737 (95%CI 0.496-1.095), respectively. VDR-SNPs, vitamin D3, TNF-α, and MIF could play an essential role in the pathogenesis and progression of KOA with mechanistic associations.

1,25-Dihydroxycholecalciferol (calcitriol) modifies uptake and release of 25-hydroxycholecalciferol in skeletal muscle cells in culture

The major circulating metabolite of vitamin D₃, 25-hydroxycholecalciferol [25(OH)D], has a remarkably long half-life in blood for a (seco)steroid. Data from our studies and others are consistent with the hypothesis that there is a role for skeletal muscle in the maintenance of vitamin D status. Muscle cells internalise vitamin D-binding protein (DBP) from the circulation by means of a megalin/cubilin plasma membrane transport mechanism. The internalised DBP molecules then bind to actin and thus provide an intracellular array of high affinity binding sites for its specific ligand, 25(OH)D. There is evidence that the residence time for DBP in muscle cells is short and that it undergoes proteolytic degradation, releasing bound 25(OH)D. The processes of internalisation of DBP and its intracellular residence time, bound to actin, appear to be regulated. To explore whether 1,25-dihydroxycholecalciferol (calcitriol) has any effect on this process, cell cultures of myotubes and primary skeletal muscle fibers were incubated in a medium containing 10^-10M calcitriol but with no added DBP. After 3h pre-incubation with calcitriol, the net uptake of 25(OH)D by these calcitriol-treated cells over a further 4h was significantly greater than that in vehicle-treated control cells. This was accompanied by a significant increase in intracellular DBP protein. However, after 16h of pre-incubation with calcitriol, the muscle cells showed a significantly depressed ability to accumulate 25(OH)D compared to control cells over a further 4 or 16hours. These effects of pre-incubation with calcitriol were abolished in fibers from VDR-knockout mice. The effect was also abolished by the addition of 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS), which inhibits chloride channel opening. Incubation of C2 myotubes with calcitriol also significantly reduced retention of previously accumulated 25(OH)D after 4 or 8h. It is concluded from these in vitro studies that calcitriol can modify the DBP-dependent uptake and release of 25(OH)D by skeletal muscle cells in a manner that suggests some inducible change in the function of these cells.

The importance of vitamin D in maternal and child health: a global perspective

Vitamin D and calcium are important nutrients for skeletal growth and bone health. Children and pregnant women are particularly vulnerable to 25-hydroxy vitamin D deficiency (VDD). VDD, with or without dietary calcium deficiency, can lead to nutritional rickets (NR), osteomalacia, and disturbances in calcium homeostasis. Multiple studies have linked VDD to adverse health outcomes in both children and pregnant women that extend beyond bone health. VDD remains an important global public health concern, and an important differentiation must be made between the impact of VDD on children and adults. Reports of increased incidence of NR continue to emerge. NR is an entirely preventable condition, which could be eradicated in infants and children worldwide with adequate vitamin D and calcium supplementation. The desire and necessity to put in place systems for preventing this potentially devastating pediatric disease should not elicit dispute. VDD and NR are global public health issues that require a collaborative, multi-level approach for the implementation of feasible preventative strategies. This review highlights the history, risk factors, and controversies related to VDD during pregnancy and childhood with a particular focus on global NR prevention.

Vitamin D deficiency, oxidative stress and antioxidant status: only weak association seen in the absence of advanced age, obesity or pre-existing disease

Vitamin D deficiency (plasma 25-hydroxycholecalciferol (25(OH)D)70 % of participants were vitamin D deficient. No significant correlations and no biomarker differences across 25(OH)D quartiles or groups were seen except for total antioxidant status. A weak direct association (r 0·252, P<0·05) was observed between 25(OH)D and FRAP, and those in the lowest 25(OH)D quartile and group had significantly lower FRAP values. Results did not reveal a clear link between vitamin D status and oxidative stress biomarkers in the absence of advanced age, obesity and disease, though some evidence of depleted antioxidant status in those with vitamin D deficiency was seen. Poor antioxidant status may pre-date increased oxidative stress. Study of effects of correction of deficiency on antioxidant status and oxidative stress in vitamin D-deficient but otherwise healthy subjects is needed.

Serum 25-hydroxyvitamin D3 and 24R,25-dihydroxyvitamin D3 concentrations in adult dogs are more substantially increased by oral supplementation of 25-hydroxyvitamin D3 than by vitamin D3

We previously found a weak response in serum 25-hydroxyvitamin D₃ (25(OH)D₃) concentrations when dogs were supplemented with oral vitamin D₃ (D₃). In the present study, we determined the relative potency of oral 25(OH)D₃ compared with D₃ for increasing vitamin D status in dogs with low serum 25(OH)D concentrations. Four male and three female, 4-year-old, intact, lean, genetically related, Chinese-crested/beagle dogs were studied in a randomised, single cross-over trial. After feeding a low-vitamin D diet (<4 IU/100 g) for 30 d, four dogs received daily D₃ supplementation at 2·3 µg/kg body weight^0·75, while three dogs received a molar equivalency as 25(OH)D₃. The supplements, dissolved in ethanol, were applied to a commercial treat for consumption. Serum 25(OH)D₃ and 24R,25-dihydroxyvitamin D₃ (24R,25(OH)₂D₃) were analysed weekly using a validated HPLC method. Both supplementations increased (P ≤ 0·01) serum 25(OH)D₃ concentrations. However, oral 25(OH)D₃ resulted in greater (P < 0·0001) concentrations than D₃ by week 1, with a difference of 173 % (P < 0·0001) by week 2. The supplementation period was limited to 14 d after serum 25(OH)D₃ concentrations were not appearing to plateau. Thereafter, a washout period of 1 month separated the cross-over. Following 25(OH)D₃, but not D₃ supplementation, serum 24R,25(OH)₂D₃ concentrations increased (P ≤ 0·02), 3 to 5 weeks after initiating supplementation. Vitamin D status, as indicated by serum 25(OH)D₃ and 24R,25(OH)₂D₃ concentrations, is more rapidly and efficiently increased in adult dogs by oral supplementation of 25(OH)D₃ than D₃.

Multicomponent, multitarget integrated adjustment - Metabolomics study of Qizhiweitong particles curing gastrointestinal motility disorders in mice induced by atropine

ETHNOPHARMACOLOGICAL RELEVANCE

Qizhiweitong particles (QZWT) which is derived from the Sinisan decoction in Shang Han Za Bing Lun, composed of Bupleurum chinenis, Paeonia obovata, Citrus aurantium L., Glycyrrhiza uralensis Fisch., Cyperus rotundus and Rhizoma Corydalis is a traditional Chinese medicine (TCM) treating gastrointestinal diseases. It have been used in clinical for years. It have been used in clinical for years. According to previous research, Bupleurum chinenis, Citrus aurantium, Cyperus rotundus in QZWT play the role of promoting gastric peristalsis, which consist of complex chemical constituents. The aim of this study is to probe the multiple effective components with gastrointestinal prokinetic efficacy in QZWT and investigate the multitarget integrated adjustment mechanism of QZWT curing atropine-induced gastrointestinal motility dysfunction mice.

MATERIALS AND METHODS

One hundred and thirty two male mice were randomly divided into 11 groups, including control group, model group, Domperidone group, Mosapride group, QZWT group and six components groups. With gastric retention rate, rate of small intestine propulsion, serum content of GAS and MTL as indexes to evaluate the curing effect on gastrointestinal movement disorders caused by atropine in mice. A serum metabonomics method based on the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) had been established to investigate the mechanism of QZWT and these components, and PCA and PLS-DA have been used to distinguish different groups and found potential biomarkers.

RESULTS

Four components from six present good prokinetic effects, including Bupleurum Polysaccharide, Citrus aurantium flavonoid, Citrus aurantium essential oil and Cyperus rotundus flavonoids. These components and QZWT regulate 5 potential biomarkers in the body, and primarily involved in 5 metabolic pathways. These potential biomarkers possess direct or indirect connections, each biomarker regulated by multiple components, each component adjusting multiple targets, and QZWT is nearly the sum of its components.

CONCLUSIONS

This experiment deepened our understanding of insufficient gastrointestinal dynamics, confirmed that QZWT treating gastrointestinal disorders was through multicomponent, multitarget ways. These results fully reflect the multiple targets synergy characteristics of TCM.

Impact of a cholesterol membrane transporter's inhibition on vitamin D absorption: A double-blind randomized placebo-controlled study

Oral supplements are important to prevent and treat vitamin D deficiency. Despite the growing number of prescriptions, vitamin D's absorptive mechanisms are not clearly elucidated. By evaluating the effect of ezetimibe on vitamin D absorption, we aim to determine if the cholesterol transporter Niemann-Pick C1-Like 1 transporter contributes to it. This randomized, double-blind, placebo-controlled trial (ClinicalTrials.govNCT02234544) was developed in a South Brazilian University Hospital. Fifty-one medical students were randomized to ezetimibe 10mg/day or placebo for 5 days. On the fifth and 19th days, blood samples for 25-hydroxycholecalciferol (25OHD), parathyroid hormone (PTH), calcium, and albumin were collected. After the first blood sample collection, all participants received a single oral 50,000 IU cholecalciferol dose during a 15 g-fat meal. Serum 25OHD levels were measured by the immunoassay Diasorin Liaison®. Measurements were compared in a general linear model adjusted for multiple comparisons by the Bonferroni test. Before cholecalciferol administration, 25OHD was <30 ng/mL and <20 ng/mL, respectively, in all and in 82.3% of the participants. Fourteen days after a single 50,000 IU oral dose of cholecalciferol, mean (SD) changes in serum 25OHD were similar in both groups, after adjustment to BMI and 25OHD levels before cholecalciferol administration (p=0.26): 8.7 (3.7) ng/mL in the ezetimibe group, versus 10.0 (3.8) ng/mL in the placebo group. Mean serum 25OHD, PTH, calcium and albumin levels remained similar in both groups. We conclude that ezetimibe had no effect on the mean change in serum 25OHD after a single oral dose of cholecalciferol, in these healthy and young adults.

Evaluation of Relative Bioavailability of 25-Hydroxycholecalciferol to Cholecalciferol for Broiler Chickens

This study was conducted to evaluate the relative bioavailability (RBV) of 25-hydroxycholecalciferol (25-OH-D₃) to cholecalciferol (vitamin D₃) in 1- to 21-d-old broiler chickens fed with calcium (Ca)- and phosphorus (P)-deficient diets. On the day of hatch, 450 female Ross 308 broiler chickens were assigned to nine treatments, with five replicates of ten birds each. The basal diet contained 0.50% Ca and 0.25% non-phytate phosphorus (NPP) and was not supplemented with vitamin D. Vitamin D₃ was fed at 0, 2.5, 5.0, 10.0, and 20.0 μg/kg, and 25-OH-D₃ was fed at 1.25, 2.5, 5.0, and 10.0 μg/kg. The RBV of 25-OH-D₃ was determined using vitamin D₃ as the standard source by the slope ratio method. Vitamin D₃ and 25-OH-D₃ intake was used as the independent variable for regression analysis. The linear relationships between the level of vitamin D₃ or 25-OH-D₃ and body weight gain (BWG) and the weight, length, ash weight, and the percentage of ash, Ca, and P in femur, tibia, and metatarsus of broiler chickens were observed. Using BWG as the criterion, the RBV value of 25-OH-D₃ to vitamin D₃ was 1.85. Using the mineralization of the femur, tibia, and metatarsus as criteria, the RBV of 25-OH-D₃ to vitamin D₃ ranged from 1.82 to 2.45, 1.86 to 2.52, and 1.65 to 2.05, respectively. These data indicate that 25-OH-D₃ is approximately 2.03 times as active as vitamin D₃ in promoting growth performance and bone mineralization in broiler chicken diets.

Measurement of circulating 25-hydroxyvitamin D: A historical review

The constantly increasing requests for the measurement of serum 25-hydroxyvitamin D over the last years has led reagent manufacturers to market different automated and semi-automated methods, that being unfortunately not fully harmonized, yield different results. Liquid chromatography coupled to tandem mass spectrometry (LC/MS2) has more recently been introduced. This approach allows the distinction between the two forms of 25-hydroxyvitamin D and to measure other metabolites. This approach also requires harmonization to curtail the differences between the different analytical methods. To meet this requirement, the American National Institutes of Health (NIH), the Centre for Disease Control and Prevention (CDC) in Atlanta, the National Institute of Standards and Technology (NIST) and the vitamin D Reference laboratory of Ghent University have pooled their expertise to develop a standardization program. This article reviews the main elements and the difficulties of the automated and semi-automated methods for 25-hydroxyvitamin D, from sample preparation to the analytical phase, as well as those related to mass spectrometry. It also emphasizes the need for standardization to better define the clinical decision thresholds of vitamin D nutritional status.

Calcium-phosphate metabolism in patients with multiple sclerosis

INTRODUCTION AND OBJECTIVES

The purpose of this study was to evaluate the concentration of 25-hydroxycholecalciferol and parameters of calcium-phosphate metabolism at different periods of relapsing-remitting multiple sclerosis (RRMS).

MATERIALS AND METHODS

Forty-five patients, residents of Poland (49°-50°, N), were enrolled in the study, i.e. 15 immediately after the diagnosis of RRMS, 15 at the early stage and 15 at the advanced stage of RRMS. The results were compared to values obtained in 20 age- and sex-matched controls.

RESULTS

Lower serum concentrations of 25-hydroxycholecalciferol and ionised calcium were found in patients compared to the control group. In patients with the disease duration of 5-6 years, concentrations of 25-hydroxycholecalciferol and ionised calcium were lower than in patients in the earlier period of RRMS. The inverse and clearer direction of changes was found in parathormone serum concentration in patients compared to the controls. In patients with a longer disease duration, a significantly lower 25-hydroxycholecalciferol concentration was found in female patients compared to male patients. In patients, more frequent 25-hydroxycholecalciferol and unsaturated fatty acids' supplementation was observed compared to the controls.

CONCLUSIONS

In RRMS patients, calcium-phosphate metabolism is disturbed which increases during disease progression.