Effect of Vitamin D on Experimental Autoimmune Neuroinflammation Is Dependent on Haplotypes Comprising Naturally Occurring Allelic Variants of CIITA (Mhc2ta).

An increasing body of evidence associates low vitamin D levels with increased risk of multiple sclerosis (MS), suggesting the possibility of a gene-environment interaction for this environmental factor in MS pathogenesis. Moreover, it has been shown that vitamin D downregulates major histocompatibility complex (MHC) class II expression in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. We here report about the impact of a dietary vitamin D supplementation on EAE in the rat strains having functionally relevant allelic variations in the CIITA (Mhc2ta) gene, a master regulator of MHC class II expression. Full length myelin oligodendrocyte glycoprotein (MOG)-EAE was induced in DA.PVGav1-Vra4 congenic rats harboring the Vra4 locus from PVG strain in the EAE- susceptible DA background, and compared to the parental strains. The congenic rats fed with either vitamin D supplemented, deprived or regular diet developed an intermediate clinical EAE phenotype, in contrast to DA and PVG strains. Immunopathological studies revealed vitamin D dose-dependent effect on demyelination and inflammatory infiltration of the central nervous system (CNS), expression of MHC class II and CIITA, as well as downregulation of a range of pro-inflammatory genes. Taken together, our findings demonstrate an impact of vitamin D on the target tissue pathology and peripheral immune response during EAE in DA.PVGav1-Vra4 congenic strain. Thereby, our data provide evidence of a modulatory effect of vitamin D in context of genetic variances in the Vra4 locus/Mhc2ta gene in MS-like neuroinflammation, with potential relevance for the human demyelinating disease.

Maternal vitamin D deficiency and fetal distress/birth asphyxia: a population-based nested case-control study.

OBJECTIVE: Vitamin D deficiency causes not only skeletal problems but also muscle weakness, including heart muscle. If the fetal heart is also affected, it might be more susceptible to fetal distress and birth asphyxia. In this pilot study, we hypothesised that low maternal vitamin D levels are over-represented in pregnancies with fetal distress/birth asphyxia. DESIGN AND SETTING: A population-based nested case-control study. PATIENTS: Banked sera of 2496 women from the 12th week of pregnancy. OUTCOME MEASURES: Vitamin D levels were analysed using a direct competitive chemiluminescence immunoassay. Vitamin D levels in early gestation in women delivered by emergency caesarean section due to suspected fetal distress were compared to those in controls. Birth asphyxia was defined as Apgar <7 at 5 min and/or umbilical cord pH≤7.15. RESULTS: Vitamin D levels were significantly lower in mothers delivered by emergency caesarean section due to suspected fetal distress (n=53, 43.6±18 nmol/L) compared to controls (n=120, 48.6±19 nmol/L, p=0.04). Birth asphyxia was more common in women with vitamin D deficiency (n=95) in early pregnancy (OR 2.4, 95% CI 1.1 to 5.7). CONCLUSIONS: Low vitamin D levels in early pregnancy may be associated with emergency caesarean section due to suspected fetal distress and birth asphyxia. If our findings are supported by further studies, preferably on severe birth asphyxia, vitamin D supplementation/sun exposure in pregnancy may lower the risk of subsequent birth asphyxia.

Efficacy of vitamin D in treating multiple sclerosis-like neuroinflammation depends on developmental stage.

The association of vitamin D deficiency with higher prevalence, relapse rate and progression of multiple sclerosis (MS) has stimulated great interest in using vitamin D supplementation as a preventative measure and even a therapy for established MS. However, there is a considerable lack of evidence when it comes to an age/developmental stage-dependent efficacy of vitamin D action and a time-window for the most effective prophylactic treatment remains unclear. We studied the effect of vitamin D supplementation in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), an animal model of MS, at three different developmental stages in rats. Supplementation treatment was initiated: i) prior to gestation and maintained throughout pre- and early postnatal development (gestation and lactation); ii) after weaning, throughout juvenile/adolescence period and iii) in adult age. We observed a marked attenuation of EAE in juvenile/adolescent rats reflected in a less severe CNS inflammation and demyelination, accompanied by a lower amount of IFN-γ producing MOG-specific T cells. Moreover, the cytokine expression pattern in these rats reflected a more anti-inflammatory phenotype of their peripheral immune response. However, the same supplementation regimen failed to improve the disease outcome both in adult rats and in rats treated during pre- and early post-natal development. Our data demonstrate a developmental stage-dependent efficiency of vitamin D to ameliorate neuroinflammation, suggesting that childhood and adolescence should be the target for the most effective preventive treatment.

Homogeneous assay for real-time and simultaneous detection of thymidine kinase 1 and deoxycytidine kinase activities.

Measurement of thymidine kinase-1 (TK1) and deoxycytidine kinase (dCK) activity may be useful in cancer disease management. Therefore, a one-step homogeneous assay for real-time determination of TK1 and dCK was developed by combining enzyme complementation with fluorescent signal generation using primer extension and a quenched probe oligodeoxyribonucleotide system at 37 °C. Complementation, for producing dCTP and TTP from nucleoside substrates, was carried out by dTMP kinase and/or UMP/CMP kinase and nucleoside diphosphate kinase. dNTP was continuously incorporated into a fixed oligodeoxyribonucleotide primer, template, and probe system, and the fluorescent signal was generated by using the combined actions of primer extension and 5' exonuclease activity of Thermophilus aquaticus (Taq) DNA polymerase for specific relief of fluorescent quenching. Fluorescence was captured at 1-min intervals using a real-time polymerase chain reaction (PCR) instrument. A horizontal threshold line, crossing all sample relative fluorescent units (RFU) values at the level of the RFU of the blank sample at the end of the assay (i.e., 90 min), was drawn, obtaining RFU measurement data in minutes for each sample. Duplex proof of principle was demonstrated by the independent determination of different amounts of dCK and TK1 in combination. R(2) values of 0.90 were demonstrated with Prolifigen TK-REA U/L reference values obtained from pathological canine and human serum samples.

Depressed adolescents in a case-series were low in vitamin D and depression was ameliorated by vitamin D supplementation.

AIM: The relationship between depression in adolescents and vitamin D was studied in a case-series that included effects of vitamin D supplementation. METHODS: Serum 25OH vitamin D (25OHD) levels in 54 Swedish depressed adolescents were investigated. Subjects with vitamin D deficiency were given vitamin D(3) over 3 months (n = 48). To evaluate well-being and symptoms related to depression and vitamin D status, the WHO-5 well-being scale, the Mood and Feelings Questionnaire (MFQ-S) and a vitamin D deficiency scale were used. RESULTS: Mean serum 25OHD in the depressed adolescents was 41 at baseline and 91 nmol/L (p < 0.001) after supplementation. Basal 25OHD levels correlated positively with well-being (p < 0.05). After vitamin D supplementation, well-being increased (p < 0.001) and there was a significant improvement in eight of the nine items in the vitamin D deficiency scale: depressed feeling (p < 0.001), irritability (p < 0.05), tiredness (p < 0.001), mood swings (p < 0.01), sleep difficulties (p < 0.01), weakness (p < 0.01), ability to concentrate (p < 0.05) and pain (p < 0.05). There was a significant amelioration of depression according to the MFQ-S (p < 0.05). CONCLUSION: This study showed low levels of vitamin D in 54 depressed adolescents, positive correlation between vitamin D and well-being, and improved symptoms related to depression and vitamin D deficiency after vitamin D supplementation.

Physical training increases osteoprotegerin in postmenopausal women.

The purpose of this study was to explore whether mechanical loading by exercise over a 1-year period in postmenopausal women had an effect on the receptor activator for nuclear factor kappa B ligand/osteoprotegerin (RANKL/OPG) system or the levels of the Wnt-signaling antagonist sclerostin. A total of 112 postmenopausal were randomized to either sedentary life (controls) or physical activity (training group). Ninety-two women fulfilled the study protocol. The training program consisted of three fast 30-min walks and one or two 1-h aerobic training sessions per week. The effect on the bone mineral density of the hip assessed with dual X-ray absorptiometry was positive as reported earlier. Blood samples were taken from participants at baseline and after 1 year and serum levels of OPG, RANKL and sclerostin were quantified together with the bone metabolism markers C-terminal telopeptide of collagen type I (CTX) and bone-specific alkaline phosphatase (BALP). The results were analyzed using an analysis of covariance model using baseline values as the covariate. The training group displayed a clear mean increase of OPG +7.55 pg/ml compared to controls (p = 0.007). The mean changes for RANKL +0.19 pg/ml (square-root transformed data) and sclerostin +0.62 pmol/l were non-significant (p = 0.13 and p = 0.34). The changes in bone turnover markers CTX and BALP showed a tendency to decrease in the training group versus controls but the changes were small and non-significant. Although our study is limited in number of participating women, we have been able to show an OPG-associated, and RANKL- and sclerostin-independent, training-induced inhibition of postmenopausal bone loss.

Serum cardiac troponin T, troponin I, plasma BNP and left ventricular mass index in professional football players.

UNLABELLED: Concentrations of cardiac troponins (cTn) in serum or plasma may be elevated in several disease states other than acute coronary syndromes. In heart failure and end stage renal disease, cardiac troponin T (cTnT) correlates positively with left ventricular mass index (LVMI). Exercise-induced elevation of cardiac troponins in well-trained athletes has been confirmed by several reports but the aetiology and clinical significance is unclear. In the present study, we measured baseline concentrations of cardiac markers and investigated whether or not serum cTnT is associated with left ventricular hypertrophy (LVH) in professional football players. METHODS: Twenty-three male professional football players with a mean age of 23 years (range 18-32) were studied. Echocardiography and blood sampling were carried out approx 24h after a training session. Serum cTnT, other cardiac markers and plasma brain natriuretic peptide (BNP) were compared with LVMI. RESULTS: cTnT was only detectable in one subject. The prevalence of elevated cardiac troponin I (cTnI), creatine kinase MB (CKMB) and creatine kinase was higher than for cTnT. cTnI concentrations were higher in football players than in controls. LVMI did not correlate with any of the cardiac markers. Plasma BNP concentrations were normal in all subjects. CONCLUSION: Serum cTnT concentrations were not elevated in healthy professional football players with LVH. This argues against the hypothesis that LVH per se may cause increased cTnT. The finding of higher cTnI in football players than in non-athletic controls should be confirmed and the aetiology elucidated.

Cardiac troponin T content in heart and skeletal muscle and in blood samples from ApoE/LDL receptor double knockout mice.

BACKGROUND: The isolated perfused mouse heart is a useful experimental model, and cardiac troponin T (cTnT) in coronary effluent may be a sensitive marker of myocardial damage. In recent years, the apolipoprotein E/low-density lipoprotein receptor double knockout (apoE/LDLr KO) mice have become valuable tools in atherosclerosis research. The aim of the study was to validate measurements of cTnT in heart, skeletal muscle, and serum of apoE/LDLr KO mice. METHODS: Wild-type C57BL/6J mice were fed with standard diet, and apoE/LDLr KO mice were fed an atherogenic diet. Blood was sampled from the jugular vein or the thoracic cavity. Heart and femoral skeletal muscle were sampled and homogenized. cTnT was measured with the third-generation cTnT assay (Troponin T STAT) on Elecsys 2010 immunoassay analyser (Roche Diagnostics). RESULTS: Median serum cTnT in samples from the thoracic cavity of C57BL/6J mice was about 20-90 times higher, and from ApoE/LDLr KO mice about 30 times higher than serum cTnT in samples from the external jugular vein. There was no difference in cTnT content (microg cTnT/g heart muscle) in hearts from C57BL/6J and apoE/LDLr KO mice. The median cTnT content in skeletal muscle was less than 0.1% of the cTnT content in heart muscle. CONCLUSION: There is no difference in cTnT content of heart muscle comparing C57BL/6J and ApoE/LDLr KO mice, which have larger hearts. Sampling from the thoracic cavity causes unacceptably high cTnT levels. Serum cTnT in samples from the jugular vein is only slightly elevated. Elevated baseline levels of cTnT in mice are not caused by troponin T from skeletal muscle.

Elevated cardiac troponin T in peritoneal dialysis patients is associated with CRP and predicts all-cause mortality and cardiac death.

BACKGROUND: Cardiac troponin T (cTnT) is a highly sensitive and specific marker of myocardial damage. In sera from patients with end-stage renal disease, cTnT may be elevated without other signs of acute myocardial injury. It has been shown that elevated cTnT in haemodialysis patients is associated with poor prognostic outcome. The aim of the present study was to test the hypothesis that elevated cTnT in a single serum sample from peritoneal dialysis (PD) patients is of prognostic importance. METHODS: Blood samples were taken from 26 randomly selected PD patients without signs of acute myocardial ischaemia. Sera were analysed for: cTnT with the second generation TnT ELISA on ES 300; cardiac troponin I (cTnI) with Opus Plus; and for creatine kinase-MB (CKMB) mass and C-reactive protein (CRP). After 4 years, clinical outcomes were evaluated by chart review. The influence on survival was tested with Kaplan-Meier analysis and Cox's proportional regression analysis. RESULTS: Concentrations of cTnT >/=0.04 micro g/l and CRP >/=10 mg/l were strong predictors of all-cause mortality in univariate analysis. Twelve out of 14 patients with cTnT >/=0.04 micro g/l died compared with three out of 12 with cTnT <0.04 micro g/l. Other factors that influenced survival were age and the presence of ischaemic heart disease (IHD). There was a significant positive correlation between cTnT and CRP, and between cTnT and age. Cardiac troponin T was an independent predictor compared with age but not compared with CRP and IHD. Neither cTnI nor CKMB mass concentrations were related to survival. CONCLUSION: Elevated serum concentrations of cTnT significantly predicted poor outcome and there was a correlation between cTnT and CRP concentrations in samples from PD patients. Cardiac troponin I and CKMB mass had no prognostic value.