Non-Skeletal Activities of Vitamin D: From Physiology to Brain Pathology

Clinical correlates of serum 25-hydroxyvitamin D in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) patients have lower levels of serum 25-hydroxyvitamin D (25(OH)D) than the general population. Previous studies have suggested a negative association between 25(OH)D and clinical features of PD, but the data are inconsistent.

MATERIALS AND METHODS

We conducted a cross-sectional, observational study. Serum 25(OH)D, disease (Hoehn-Yahr stage [HY]) and clinical symptom (Unified Parkinson Disease Rating Scale [UPDRS]) severity and global cognitive functions (Mini-Mental State Examination [MMSE]) were studied in 500 consecutive PD patients not using vitamin D supplements. Information on sunlight exposure and dietary intakes (using a 66-item food frequency questionnaire) were also collected. A convenient sample of age and sex-matched community healthy controls (N = 100) was included as a control group.

RESULTS

PD patients had lower 25(OH)D serum levels than controls. Deficiency status (<20 ng/mL) was found in 65.6% of patients. 25(OH)D levels were independently correlated to sunlight exposure (P = .002) and vitamin D intake (P = .009). In multivariate models, using a Mendelian randomization approach, lower serum 25(OH)D was associated with more severe disease (HY, P = .035), worse clinical symptoms (UPDRS Part-III total score [P = .006] and dopaminergic [P = .033] and non-dopaminergic subscores [P = .001]) and greater global cognitive function impairment (P = .041). Neither cognitive functions nor clinical features were associated with reduced intake of vitamin D and sunlight exposure.

CONCLUSION

: Serum 25(OH)D was negatively correlated with disease and symptoms severity, as well as with global cognitive functions. Our study adds to the evidence that low 25(OH)D may affect the progression of PD negatively. Intervention studies in this area are required.

The importance of T cell-derived cytokines in post-kala-azar dermal leishmaniasis

Infection with the same species of Leishmania (L)donovani causes different manifestations including visceral leishmaniasis (VL) and post kala-azar dermal leishmaniasis (PKDL), indicating that the host-related immunological parameters perform a decisive role in the pathogenesis of diseases. As PKDL is a reservoir of the parasite, a better understanding of the host immune responses is necessary to restrict the L. donovani transmission. The proper local production of Th1 cell-related cytokines (including IFN-γ, TNF-α and IL-12), Th17 cell-derived cytokines (such as IL-17A, IL-17F and IL-22), and CD8⁺ cytotoxic T lymphocyte (CTL)-derived IFN-γ are protective against PKDL. However, dominant production of regulatory CD4⁺ T cell-derived cytokines (such as IL-10 and TGF-β), Th2 cell-derived cytokines (such as IL-4/IL-13), M2 macrophage-derived cytokines (such as IL-4 and IL-10), keratinocyte-derived IL-10, regulatory CD8⁺ T cell-derived IL-10, and dendritic cell-derived IL-10, IL-27 and IL-21 can contribute to the parasite persistence and PKDL development. Understanding of the T cell-related cytokine network within PKDL lesions gives rise to novel insights concerning the role of each cytokine in the protection or susceptibility to disease. Manipulation of the cytokine network can be considered as an interesting immunotherapeutic strategy for the treatment of L. donovani-mediated PKDL.

Genetic variants of vitamin D metabolism-related DHCR7/NADSYN1 locus and CYP2R1 gene are associated with clinical features of Parkinson's disease

PURPOSE/AIM OF THE STUDY

Parkinson's disease (PD) is the second most common neurodegenerative disorder. Vitamin D deficiency is suggested to be related to PD. A genome-wide association study indicated that genes involved in vitamin D metabolism affect vitamin D levels. Among these genes, single nucleotide polymorphisms (SNPs) of the vitamin D receptor (VDR) and vitamin D binding protein (VDBP/GC) genes have also been demonstrated to be associated with PD risk. Our aim was to investigate the relevance of SNPs within the 7-dehydrocholesterol reductase/nicotinamide adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) locus and vitamin D 25-hydroxylase (CYP2R1) gene, which encode important enzymes that play a role in the vitamin D synthesis pathway, with PD and its clinical features.

MATERIALS AND METHODS

Genotypes of 382 PD patients and 240 cognitively healthy individuals were evaluated by a LightSNiP assay for a total of 10 SNPs within the DHCR7/NADSYN1 locus and CYP2R1 gene.

RESULTS

There were no significant differences in the allele and genotype distributions of any of the SNPs between any patient groups and healthy subjects. However, our results indicated that all of the SNPs within the DHCR7/NADSYN1 locus and CYP2R1 gene, except rs1993116, were associated with clinical motor features of PD including initial predominant symptom, freezing of gait (FoG) and falls as well as disease stage and duration of the disease.

CONCLUSIONS

In conclusion, genetic variants of the DHCR7/NADSYN1 locus and the CYP2R1 gene might be related to the inefficient utilization of vitamin D independent from vitamin D levels, and it might result in differences in the clinical features of PD patients.

Oral intermittent vitamin D substitution: influence of pharmaceutical form and dosage frequency on medication adherence: a randomized clinical trial

Background

To assess adherence to and preference for vitamin D substitution with different pharmaceutical forms and frequencies of administration.

Methods

A focus group of stakeholders aimed at preparing the design of an interventional, randomized, cross-over study with 2 × 2 groups obtaining monthly or weekly vitamin D products in liquid or solid form for 3 months each. Dosage corresponds to cumulated amount of recommended 800 IU daily (5.600 IU weekly / 24.000 IU monthly). Main inclusion criteria were a vitamin D serum value < 50 nmol/l and age ≥ 18 years. Primary endpoint was adherence, secondary endpoints were preferences and vitamin D serum levels.

Results

The focus group reached consensus for preference of a monthly administration of solid forms to adults.

Full datasets were obtained from 97 participants. Adherence was significantly higher with monthly (79.5–100.0%) than weekly (66.4–98.1%) administration. Vitamin D levels increased significantly (p < 0.001) in all participants. An optimal value of > 75 nmol/l was achieved by 32% after 3 months and by 50% after 6 months. Preferred formulation was solid form (tablets, capsules) for 71% of participants, and preferred dosage frequency was monthly for 39% of participants.

Conclusions

Monthly oral vitamin D in solid form lead to the highest adherence, and is preferred by the participants. However, only one third of study participants achieved values in the optimal range of > 75 nmol/l cholecalciferol using weekly or monthly administration providing an average daily cholecalciferol dose of 800 IU.

Trial registration

NCT03121593 | SNCTP000002251. Registered 30. May 2017,. Prospectively registered.

Network pharmacology strategy for predicting the correlation of Systemic Scleroderma with Vitamin D deficiency

The deficiency of Vitamin D (V_D) is a common symptom of systemic scleroderma (SSc), but the correlation of V_D deficiency and SSc is not completely clear. Therefore, a strategy based on network pharmacology was designed to explore the correlation of V_D deficiency and SSc. After a series of network construction and analysis, 5 integrins were predicated as the kernel targets in the correlation of V_D deficiency and SSc, including ITGA5, ITGA4, ITGB3, ITGB1 and ITGAV. The crucial pathways in which the kernel targets participated were mainly involved in the function of immune, vascular and internal organ. The regulation modules of crucial pathways were closely related to the biological processes in the pathological of SSc. Taken together, the analysis predicted that the deficiency of V_D might affect the pathological of SSc through the mediation of these integrins. Therefore, targeted regulation of these integrins might be an effective therapy against SSc.

Association between serum vitamin D and depressive symptoms in apparently healthy male adults undergoing routine health check-ups at a single centre

OBJECTIVE

To determine the level of vitamin D and to identify the association between vitamin D and depressive symptoms in apparently healthy Korean male adults.

DESIGN

A retrospective study design. Among 43 513 participants between 1 March and 30 November 2018, after eliminating participants with a history of depression or vitamin D deficiency, 9058 were included. To determine the level of vitamin D, serum 25-hydroxyvitamin D [25(OH)D] was measured. To assess the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was used.

SETTING

South Korea.

PARTICIPANTS

Male adults who underwent routine health check-ups.

RESULTS

The average vitamin D level was 22·31 ± 7·09 ng/ml as 25(OH)D, while the number of subjects in the vitamin D insufficiency group with a finding of <20 ng/ml was 3783 (41·8 %). The mean CES-D score in all subjects was 8·31 ± 5·97 points, and the proportion of the depressive symptoms group with a score of ≥16 was 8·71 %. The OR of patients in the depressive symptoms group also being in the insufficiency group was found to be 1·49 (95 % CI 1·12, 2·00).

CONCLUSIONS

A total of 41·8 % of apparently healthy male adults had vitamin D levels <20 ng/ml. We identified an association between vitamin D insufficiency and depressive symptoms in apparently healthy Korean male adults.

Carboxymethyllysine and carboxyethyllysine in multiple sclerosis patients

Introduction

Advanced glycation end-products (AGE) are involved in the pathogenesis of many diseases, including neurodegenerative diseases such as multiple sclerosis (MS). The aim of the study was to evaluate the intensity of the protein glycation process in patients with multiple sclerosis and its possible involvement in disease activity.

Material and methods

The study group (n = 45) consisted of patients suffering from MS, and the control group (n = 31) consisted of healthy adults. Concentrations of selected glycation markers such as carboxymethyllysine (CML) and carboxyethyllysine (CEL) in sera of patients with MS and healthy volunteers were determined by enzyme-linked immunosorbent assay (ELISA).

Results

Serum CML and CEL concentrations in patients with MS were higher than in healthy volunteers but only for CML the difference was statistically significant. CML concentrations positively correlated with CEL concentrations only in the healthy persons. In MS patients the serum CML and CEL concentrations did not differ significantly depending on the duration of the disease and depending on the EDSS (Expanded Disability Status Scale) score.

Conclusions

Multiple sclerosis is accompanied by an intensification of protein glycation processes, especially within the pathways leading to the formation of carboxymethyllysine. The duration of the disease and the degree of motor impairment do not appear to affect the progression of the glycation processes. However, the disease process associated with multiple sclerosis may affect the relationship between CML and CEL concentrations.

Combined treatment with vitamin D3 and antibody agents suppresses secondary heart transplant rejection in the early postoperative period

BACKGROUND

Accelerated transplant rejection mediated by donor reactive memory T cells is another barrier to the induction of graft tolerance. The aim of this study was to investigate the immunosuppressing effects of vitamin D (1,25(OH)2D3), administered alone or in combination with a costimulatory blockade treatment, on rejection of secondary heart allografts in a mouse model.

METHODS

Circular full-thickness skin grafts from BALB/c mice were cut and grafted onto the lumbar regions of C57BL/6 mice as allo-primed recipients. Four weeks after skin grafting, the vascularized hearts from the BALB/c mice were transplanted heterotopically into the allo-primed recipients using a non-suture cuff technique. The recipients were then randomly divided into four groups and given either intraperitoneal injection of isotype, Ab, 1,25(OH)2D3, or a combination of Ab and 1,25(OH)2D3. Allograft incidence was determined by hematoxylin-eosin staining, and cytokine expression was assessed by the quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and cytometric bead arrays. Spleen cells from the recipient were used to assess mixed lymphocyte reactions. Memory T cells and regulatory T cells (Tregs) in spleen cells were measured by flow cytometry.

RESULTS

The median allograft survival time was longer with the combined treatment with Ab and 1,25(OH)2D3 than with no treatment or with treatment with Ab or 1,25(OH)2D3 alone. The grafts were protected from infiltration by inflammatory cells and by inhibition of interleukin 2 and interferon gamma expression. Rejection was initially suppressed in the early postoperative period by a reduction in the number of memory T cells and induction of Foxp3⁺ Tregs, but this effect disappeared by day 15 after transplantation upon withdrawal of the treatment.

CONCLUSION

Vitamin D3 administered as an immunosuppressive agent, when combined with monoclonal antibody treatment, may protect heart grafts from memory T cell responses in a secondary heart transplant model.