Increased severity of chemically induced seizures in mice with partially deleted Vitamin D receptor gene

Correlation analysis of 25(OH)D with cognitive function in epilepsy patients: A cross-sectional study

OBJECTIVE

To analyze the correlation between the level of 25(OH)D in peripheral blood and cognitive function in patients with epilepsy, and to find the biomarkers of epilepsy complicated with cognitive dysfunction.

METHODS

68 patients with epilepsy and 30 healthy subjects were included in this study. The 25(OH)D level in peripheral blood of all subjects was detected and the score of the Montreal Cognitive Assessment Scale was performed. The patients with epilepsy were divided into a cognitively normal group (36 cases) and a cognitively impaired group (32 cases) according to the scale score. The inter-group scale score and 25(OH)D level were compared, and the correlation was analyzed.

RESULTS

The levels of 25(OH)D and MOCA in epileptic group were significantly lower than those in healthy control group. The 25(OH)D and MOCA of the cognitively impaired group were significantly lower than those of the cognitively normal group. Logistic regression analysis indicated that serum 25(OH)D level was an independent risk factor for epilepsy combined with cognitive impairment (OR = 0.704, P = 0.014). The area under ROC curve of serum 25(OH)D for diagnosis of epilepsy combined with cognitive impairment was 0.924 (95 %CI 0.866,0.981), the critical value was 34.50 nmol/L, the sensitivity was 0.778, and the specificity was 0.906.

CONCLUSION

Decreased levels of vitamin D are associated with cognitive impairment associated with epilepsy, and it may be a biomarker for early screening of cognitive impairment.

Vitamin D deficiency and effect of treatment on seizure frequency and quality of life parameters in patients with drug-resistant epilepsy: A randomized clinical trial

OBJECTIVE

This study was undertaken to assess the effect of treatment of vitamin D deficiency in drug-resistant epilepsy.

METHODS

We conducted a multicenter, double-blind, placebo-controlled, randomized clinical trial, including patients aged ≥15 years with drug-resistant focal or generalized epilepsy. Patients with 25-hydroxyvitamin D (25[OH]D) < 30 ng/mL were randomized to an experimental group (EG) receiving vitamin D3 (cholecalciferol, 100 000 IU, five doses in 3 months) or a control group (CG) receiving matched placebo. During the open-label study, EG patients received 100 000 IU/month for 6 months, whereas CG patients received five doses in 3 months then 1/month for 3 months. Monitoring included seizure frequency (SF), 25(OH)D, calcium, albumin, creatinine assays, and standardized scales for fatigue, anxiety-depression, and quality of life (Modified Fatigue Impact Scale [M-FIS], Hospital Anxiety and Depression Scale, Quality of Life in Epilepsy [QOLIE-31]) at 3, 6, and 12 months. The primary efficacy outcome was the percentage of SF reduction compared to the reference period and CG at 3 months. Secondary outcomes were SF and bilateral tonic-clonic seizure (BTCS) reduction, scale score changes, and correlations with 25(OH)D during the follow-up.

RESULTS

Eighty-eight patients were enrolled in the study (56 females, aged 17-74 years), with median baseline SF per 3 months = 16.5 and ≥2 antiseizure medications in 88.6%. In 75 patients (85%), 25(OH)D was <30 ng/mL; 40 of them were randomly assigned to EG and 34 to CG. After the 3-month blinded period, SF reduction did not significantly differ between groups. However, during the open-label period, SF significantly decreased (30% median SF reduction, 33% responder rate at 12 months). BTCSs were reduced by 52%. M-FIS and QOLIE-31 scores were significantly improved at the whole group level. SF reduction correlated with 25(OH)D > 30 ng/mL for >6 months.

SIGNIFICANCE

Despite no proven effect after the 3-month blinded period, the open-label study suggests that long-term vitamin D3 supplementation with optimal 25(OH)D may reduce SF and BTCSs, with a positive effect on fatigue and quality of life. These findings need to be confirmed by further long-term studies.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03475225 (03-22-2018).

Hormonal Changes in Women with Epilepsy

Epilepsy is a prevalent neurological disorder among women globally, often requiring long-term treatment. Hormonal fluctuations in women with epilepsy (WWE) can have reciprocal effects on epilepsy and antiseizure medications (ASMs), posing significant challenges for WWE. Notably, WWE commonly experience endocrine alterations such as thyroid dysfunctions, low bone metabolism, and reproductive hormone irregularities. On the one hand, the presence of hormones in women with epilepsy affects their susceptibility to epilepsy as well as the metabolism of antiseizure medications in various ways. On the other hand, epilepsy itself and the use of antiseizure medications impact the production, secretion, and metabolism of hormones, resulting in low fertility, increased risk of pregnancy complications, negative offspring outcomes, and so on. In order to develop more precise treatment strategies in the future, it is necessary to comprehend the explicit relationships between hormones, epilepsy, and antiseizure medications, as well as to elucidate the currently known mechanisms underlying these interactions.

Molecular insights into the pathogenic impact of vitamin D deficiency in neurological disorders

Neurological disorders are the major cause of disability, leading to a decrease in quality of life by impairing cognitive, sensorimotor, and motor functioning. Several factors have been proposed in the pathogenesis of neurobehavioral changes, including nutritional, environmental, and genetic predisposition. Vitamin D (VD) is an environmental and nutritional factor that is widely distributed in the central nervous system's subcortical grey matter, neurons of the substantia nigra, hippocampus, thalamus, and hypothalamus. It is implicated in the regulation of several brain functions by preserving neuronal structures. It is a hormone rather than a nutritional vitamin that exerts a regulatory role in the pathophysiology of several neurological disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and multiple sclerosis. A growing body of epidemiological evidence suggests that VD is critical in neuronal development and shows neuroprotective effects by influencing the production and release of neurotrophins, antioxidants, immunomodulatory, regulation of intracellular calcium balance, and direct effect on the growth and differentiation of nerve cells. This review provides up-to-date and comprehensive information on vitamin D deficiency, risk factors, and clinical and preclinical evidence on its relationship with neurological disorders. Furthermore, this review provides mechanistic insight into the implications of vitamin D and its deficiency on the pathogenesis of neurological disorders. Thus, an understanding of the crucial role of vitamin D in the neurobiology of neurodegenerative disorders can assist in the better management of vitamin D-deficient individuals.

In vivo electrophysiological study of vitamin D3 protective effects on PTZ-induced seizures in rats

Background and purpose

The purpose of the current study was to investigate the protective effects of acute and chronic administration of different doses of vitamin D3 on pentylenetetrazol (PTZ)-induced epileptiform activities in rats.

Experimental approach

Sixty Wistar rats in chronic and acute groups were used in this study. In the chronic groups, animals received vitamin D3 at 50, 100, and 150 μg/kg; vitamin D3 (50 μg/kg, i.p.) + diazepam (0.1 mg/kg, i.p.), and almond oil (i.p.) daily for two weeks whereas, in the acute groups the animal received a single dose of chemicals just 30 min before PTZ administration. The electrophysiological recording was performed by implanting a unilateral bipolar electrode in the pyramidal cell layer of the CA1 region of the hippocampus. Epileptic activities were induced by intraperitoneal injection of PTZ (80 mg/kg, i.p.). The spike count and amplitude were analyzed using the eTrace software.

Finding/Results

Chronic administration of all doses of vitamin D3 and its combination with diazepam significantly reduced both spike counts and amplitudes following PTZ administration. While the acute doses were ineffective.

Conclusion and implication

The results of the study indicated that chronic but not acute administration of vitamin D3 has a protective effect on PTZ-induced epileptiform activity in rats.

The effects of vitamin D3 and melatonin combination on pentylenetetrazole-induced seizures in mice

BACKGROUND

Epileptic seizures are associated with the overproduction of free radicals in the brain leading to neuronal cell death. Therefore, reduction of oxidative stress may inhibit seizure-induced neuronal cell damage. Current study evaluated the effects of Vit D3 and melatonin and their combination on pentylenetetrazol (PTZ)-induced tonic clonic seizures in mice.

METHODS

Animals were divided into six groups. Group I was administrated with normal saline (0.5 ml, intraperitoneally (i.p.)) on the 15th day of experiment. Group II was injected with PTZ (60 mg/kg dissolved in 0.5 ml normal saline, i.p) on the 15th day. Groups III-IV were treated with diazepam (4 mg/kg/day), Vit D3 (6000 IU/kg/day), melatonin (20 mg/kg/day) and Vit D3 (6000 IU/kg/day)/melatonin (20 mg/kg/day), respectively, and were then injected with PTZ (60 mg/kg) on the 15th day of experiment. Immediately after the injection of PTZ on the 15th day, mice were observed for a 30-min period for the measurement of seizure latency and duration. For determination of oxidative stress markers, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured in mouse brains.

RESULTS

Treatment with Vit D3, melatonin, and Vit D3/melatonin significantly increased seizure latency and decreased seizure duration. The brain level of MDA was lower and SOD activity was greater than the PTZ group. Mice treated with Vit D3/melatonin had lower seizure duration compared to other treated groups.

CONCLUSIONS

Combination of Vit D3 and melatonin may reduce seizure frequency in epileptic patients; this effect may result from various mechanisms including inhibition of oxidative stress.

Therapeutic effect of acute and chronic use of different doses of vitamin D3 on seizure responses and cognitive impairments induced by pentylenetetrazole in immature male rats

Objective(s):

This study aimed to evaluate the effects of acute and chronic intake of different doses of vitamin D3 on seizure responses and cognitive impairment induced by pentylenetetrazole (PTZ) in immature male rats.

Materials and Methods:

Sixty-six immature male NMRI rats were divided into control (10), epileptic (10), and treatment groups (46). The stage 5 latency (S5L) and stage 5 duration (S5D) were assessed along with the shuttle box test. Levels of antioxidant enzymes and inflammatory factors along with genes involved in inflammation, oxidative damage, apoptosis, and mTORc1 were measured in the hippocampus tissue of the brain of controlled and treated rats. Serum levels of parathyroid hormone (PTH), vitamin D, calcium, and phosphorus were also assessed.

Results:

The results showed that the ability to learn, memory consolidation, and memory retention in epileptic rats were reduced. In addition, S5D increased and S5L decreased in epileptic rats, while being effectively ameliorated by chronic and acute vitamin D intake. The results showed that vitamin D in different doses acutely and chronically decreased the levels of oxidative and inflammatory biomarkers in hippocampus tissue and inhibited the expression of genes involved in inflammation, oxidative damage, apoptosis, and mTORc1 in the hippocampus tissue of epileptic rats.

Conclusion:

The results showed that vitamin D in different doses acutely and chronically could improve cognitive impairments and convulsive responses in epileptic rats by improving neurotransmission, inflammation, apoptosis, and oxidative damage.

A vitamin D enriched diet attenuates sex-specific behavioral deficits, increases the lifespan, but does not rescue bone abnormalities in a mouse model of cortical dysplasia

Individuals who experience recurrent spontaneous seizures often show behavioral and physiological comorbidities. Those with epilepsy are at a high risk of bone fractures (independent of seizure-related falls) and show a higher rate of a diagnosis of Autism Spectrum Disorder. The neural subset-specific (NS) Pten knockout (KO) mouse has an epilepsy phenotype, has been characterized to show autistic-like deficits, and has an osteoporosis phenotype. The current study examined the effect of a vitamin D enriched diet (20,000 IU VD) in the NS-Pten KO and wildtype mice. Mice were placed onto a vitamin D enriched diet at 4 weeks of age and maintained on that diet throughout testing. Behavioral testing began at 6 weeks of age and included tests for general activity, anxiety, repetitive behaviors, social behaviors, and memory. Results indicated that a vitamin D diet attenuated hypoactivity levels in male KO mice (p < 0.05). In a social partition task, vitamin D increased sociability in male wildtype mice, (p < 0.05). Most significantly, vitamin D fortified diet increased percent survival in KO animals and decreased the level of microglia marker IBA-1 and mTOR (mammalian target of rapamycin) downstream targets pS6 and pAKT. A high vitamin D diet did not reverse bone deficits in male or female KO mice. Overall, these findings suggest that a vitamin D enriched diet had a significant impact on the behavioral phenotype of NS-Pten KO mice, suggesting that dietary manipulations could be a potential therapeutic option for autistic-like behavior.

Vitamin D Supplementation is Beneficial for Children with Autism Spectrum Disorder: A Meta-analysis

Objective

We conducted a meta-analysis of randomized controlled trials to explore whether vitamin D supplementation is beneficial for symptom improvement in children with autism spectrum disorder.

Methods

We systematically searched the PubMed database, EMBASE, Cochrane Library, Web of Science, Sino-Med, Wanfang Data, and China National Knowledge Infrastructure mainly up to September 2019. Using a fixed effects model, we calculated the standard mean difference with 95% confidence interval. Furthermore, we analyzed baseline serum 25-hydroxyvitamin D levels and outcome scores including the Social Responsiveness Scale and Child Autism Rating Scale scores after vitamin D supplementation.

Results

There was no significant difference in baseline serum 25-hydroxyvitamin D levels among 203 children included from three studies in the meta-analysis. After vitamin D supplementation, the outcome scores in the experimental group were dramatically elevated compared with those in the control group (p = 0.03).

Conclusion

Vitamin D supplementation improves the typical symptoms of autism spectrum disorder, as indicated by reduced Social Responsiveness Scale and Child Autism Rating Scale scores; thus, it is beneficial for children with autism spectrum disorder.

Neuroinflammation impact in epileptogenesis and new treatment strategy

Epilepsy is considered a major serious chronic neurological disorder, characterized by recurrent seizures. It is usually associated with a history of a lesion in the nervous system. Irregular activation of inflammatory molecules in the injured tissue is an important factor in the development of epilepsy. It is unclear how the imbalanced regulation of inflammatory mediators contributes to epilepsy. A recent research goal is to identify interconnected inflammation pathways which may be involved in the development of epilepsy. The clinical use of available antiepileptic drugs is often restricted by their limitations, incidence of several side effects, and drug interactions. So development of new drugs, which modulate epilepsy through novel mechanisms, is necessary. Alternative therapies and diet have recently reported positive treatment outcomes in epilepsy. Vitamin D (Vit D) has shown prophylactic and therapeutic potential in different neurological disorders. So, the aim of current study was to review the associations between different brain inflammatory mediators and epileptogenesis, to strengthen the idea that targeting inflammatory pathway may be an effective therapeutic strategy to prevent or treat epilepsy. In addition, neuroprotective effects and mechanisms of Vit D in clinical and preclinical studies of epilepsy were reviewed.

Vitamin D status among patients with drug-resistant and non-drug-resistant epilepsy

Background & Aims: Epilepsy affects nearly 70 million people worldwide. Vitamin D deficiency may influence the balance of certain epilepsies. The purpose of this study was to determine the vitamin D status and anthropometric measurements of people with epilepsy (PWE), according to their pharmacosensitivity. Methods: Forty-six PWE, with or without drug resistance, underwent nutritional assessment after giving consent. Weight, body mass index (BMI), triceps skinfold thickness (TSF), fat mass (FM) and free fat mass (FFM) by bioelectrical impedance analysis were measured. Serum vitamin D was determined without supplementation. Deficiency was defined as a level < 30 ng/mL. Statistical analysis involved Student t test, ANOVA and Chi². Results: Patients were aged 44.5 ± 14.3 years, with 60.9% of drug-resistance. BMI was 28.7 ± 7.0, 2.2% were malnourished and 30.4% obese according to the BMI. The average vitamin D level was 15.3 ± 9.9 ng/mL, with 87.0% of deficiency, and 40.0% of severe deficiency (<10 ng/mL). The TSF was higher in drug-resistant cases (p = 0.03). There was no link between drug resistance and anthropometric measurements, FM, FFM or vitamin D concentration. Conclusions: Although limited in size, this study showed that PWE are more often obese. Vitamin D deficiency is more common than in the general population, with a much higher prevalence of severe deficiency.

Expression analysis of vitamin D receptor-associated lncRNAs in epileptic patients

Vitamin D has been vastly acknowledged as a neuroactive steroid controlling neurodevelopment. As it exerts its functions through activation of vitamin D receptor (VDR), several studies have assessed the role of VDR in brain function. More recently, a number of long non-coding RNAs (lncRNAs) have been recognized that alter expression of VDR. In the current study, we evaluated expression of four VDR-related lncRNAs (LINC00511, LINC00346, SNHG6 and SNHG16) in peripheral blood of 40 epileptic patients and 39 healthy subjects using quantitative real time PCR method. The relative expression levels of SNHG16 and LINC00511 were higher in epileptic patients compared with healthy subjects. For SNHG16, the difference was only significant between male patients and male controls, while LINC00511 had the opposite pattern. The results of Quantile regression model showed significant associations between SNHG6 and SNHG16 expressions and gender (P values of 0.027 and 0.009 respectively). Significant correlations were detected between expression levels of SNHG6 and SNHG16 (r = 0.32, P = 0.004), SNHG6 and LINC00346 (r = 0.37, P = 0.001), SNHG16 and LINC00346 (r = 0.30, P = 0.007) as well as SNHG16 and LINC00511 (r = 0.29, P = 0.009). Expression of LINC00346 was inversely correlated with vitamin D levels only in male epileptic patients (r = -0.58, P = 0.011). Expression of SNHG6 was correlated with vitamin D levels in male controls but no other subgroups (r = 0.51, P = 0.044). Based on the results of ROC curve analysis, SNHG16 had the diagnostic power of 0.86 in male subjects. Taken together, the current study provides evidences for dys-regulation of VDR-related lncRNAs in epileptic patients. The clinical significance of these finding should be explored in future studies.

Functional Nutrients for Epilepsy

Epilepsy is a common neurological disorder of which seizures are a core symptom. Approximately one third of epileptic patients are resistant to antiepileptic drugs and therefore require alternative therapeutic options. Dietary and nutritional supplements can in some cases replace drugs, but with the exception of ketogenic diets, there are no officially recommended dietary considerations for patients with epilepsy. In this review we summarize a selection of nutritional suggestions that have proved beneficial in treating different types of epilepsy. We describe the types of seizures and epilepsy and follow this with an introduction to basic molecular mechanisms. We then examine several functional nutrients for which there is clinical evidence of therapeutic efficacy in reducing seizures or epilepsy-associated sudden death. We also discuss experimental results that demonstrate possible molecular mechanisms elicited by the administration of various nutrients. The availability of multiple dietary and nutritional candidates that show favorable outcomes in animals implies that assessing the clinical potential of these substances will improve translational medicine, ultimately benefitting epilepsy patients.

Safety and tolerability of Vitamin D3 5000 IU/day in epilepsy

PURPOSE

Preclinical and early clinical research indicates that Vitamin D3 may reduce seizures in both animal models and open-label clinical trials.

METHODS

This is an initial report of an ongoing pilot study of oral Vitamin D3 5000 IU/day in subjects with drug-resistant epilepsy. After Institutional Review Board (IRB) approval and informed consent, subjects with ;less than one focal onset or generalized tonic-clonic seizure per month were enrolled. Subjects entered a 4-week baseline, followed by a 12-week treatment period. Serum 25, OH Vitamin D3, Blood Urea Nitrogen (BUN), creatinine, and calcium levels were monitored at baseline and at 6 and 12 weeks.

RESULTS

High-dose Vitamin D3 5000 IU/day was well tolerated. Serum 25, OH Vitamin D3 levels increased significantly at six and twelve weeks. Vitamin D insufficiency, defined as a 25, OH Vitamin D3 level of <20 ng/ml normalized in all subjects with insufficient vitamin D levels. Median seizure frequency declined from 5.18 seizures per month to 3.64 seizures per month at 6 weeks and to 4.2 seizures per month at 12 weeks. The median percent change in seizure frequency was -26.9% at six weeks, and -10.7% at 12 weeks (not significant, Wilcoxon Signed Rank Test, P > 0.34).

CONCLUSIONS

High-dose oral Vitamin D3, 5000 IU/day was safe and well tolerated in subjects with epilepsy. Vitamin D levels increased significantly at 6 and 12 weeks but never exceeded potentially toxic levels, defined as >100 ng/ml. To reduce variability, we will now recruit subjects who only have three or more seizures per month.

Epilepsy and vitamin D: a comprehensive review of current knowledge

Vitamin D has been considered as neurosteroid, and its pivotal role in neuroprotection, brain development, and immunomodulation has been noticed in studies; however, our knowledge regarding its role in neurological disorders is still developing. The potential role of vitamin D in the pathophysiology and treatment of epilepsy, as one the most prevalent neurological disorders, has received less attention in recent years. In this article, we review the possible relationship between vitamin D and epilepsy from different aspects, including the action mechanism of vitamin D in the central nervous system and ecological and epidemiological findings. We also present the outcome of studies that evaluated the level of vitamin D and the impact of administrating vitamin D in epileptic patients or animal subjects. We also review the current evidence on interactions between vitamin D and antiepileptic drugs.

Vitamin D3 for the Treatment of Epilepsy: Basic Mechanisms, Animal Models, and Clinical Trials

There is increasing evidence supporting dietary and alternative therapies for epilepsy, including the ketogenic diet, modified Atkins diet, and omega-3 fatty acids. Vitamin D3 is actively under investigation as a potential intervention for epilepsy. Vitamin D3 is fat-soluble steroid, which shows promise in animal models of epilepsy. Basic research has shed light on the possible mechanisms by which Vitamin D3 may reduce seizures, and animal data support the efficacy of Vitamin D3 in rat and mouse models of epilepsy. Very little clinical data exist to support the treatment of human epilepsy with Vitamin D3, but positive findings from preliminary clinical trials warrant larger Phase I and II clinical trials in order to more rigorously determine the potential therapeutic value of Vitamin D3 as a treatment for human epilepsy.

Exploratory Metabolomics Profiling in the Kainic Acid Rat Model Reveals Depletion of 25-Hydroxyvitamin D3 during Epileptogenesis

Currently, no reliable markers are available to evaluate the epileptogenic potential of a brain injury. The electroencephalogram is the standard method of diagnosis of epilepsy; however, it is not used to predict the risk of developing epilepsy. Biomarkers that indicate an individual's risk to develop epilepsy, especially those measurable in the periphery are urgently needed. Temporal lobe epilepsy (TLE), the most common form of acquired epilepsy, is characterized by spontaneous recurrent seizures following brain injury and a seizure-free "latent" period. Elucidation of mechanisms at play during epilepsy development (epileptogenesis) in animal models of TLE could enable the identification of predictive biomarkers. Our pilot study using liquid chromatography-mass spectrometry metabolomics analysis revealed changes (p-value ≤ 0.05, ≥1.5-fold change) in lipid, purine, and sterol metabolism in rat plasma and hippocampus during epileptogenesis and chronic epilepsy in the kainic acid model of TLE. Notably, disease development was associated with dysregulation of vitamin D3 metabolism at all stages and plasma 25-hydroxyvitamin D3 depletion in the acute and latent phase of injury-induced epileptogenesis. These data suggest that plasma VD3 metabolites reflect the severity of an epileptogenic insult and that a panel of plasma VD3 metabolites may be able to serve as a marker of epileptogenesis.

Inhibitor effect of paricalcitol in rat model of pentylenetetrazol-induced seizures

Vitamin D has various systemic effects on bone metabolism, modulation of the immune system, stabilization of the cell membrane, oxidative stress, inflammation, apoptosis, and various other hormones. Differing from active vitamin D, paricalcitol is a relatively safe VDR agonist due to its relatively few side effects. This study has investigated the anticonvulsant effect of paricalcitol in convulsions induced by pentylenetetrazole (PTZ). 36 male Sprague-Dawley rats were divided randomly into two groups: 18 for EEG recording (PTZ 35 mg/kg) and 18 for behavioral studies (PTZ 70 mg/kg). Forty-five minutes before the PTZ injection, both groups of rats were given 5 and 10 μg/kg of paricalcitol i.p., respectively. Racine convulsion scores, first myoclonic jerk time, spike percentages, and antioxidant status were evaluated in the groups. Our results showed that the Racine's Convulsion Scale (RCS) score significantly dropped in the paricalcitol-treated group, analysis of the first myoclonic jerk (FMJ) latencies demonstrated a significantly longer latency in the paricalcitol-applied group, and spike percentages at EEG recordings significantly decreased with paricalcitol. Moreover, MDA levels were lower and SOD activity were higher in the 5 μg/kg paricalcitol group compared to the saline group; these results were more prominent in 10 μg/kg paricalcitol group. Our study has demonstrated that paricalcitol has protective effects on PTZ-induced convulsions. Based on the SOD and MDA levels in our study, these effects may result from the antioxidant characteristics of paricalcitol.

Clinical and genetic findings in a Chinese family with VDR-associated hereditary vitamin D-resistant rickets

Hereditary vitamin D-resistant rickets (HVDRR) is a rare autosomal recessive disorder characterized by severe rickets, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. This disorder is caused by homogeneous or heterogeneous mutations affecting the function of the vitamin D receptor (VDR), which lead to complete or partial target organ resistance to the action of 1,25-dihydroxy vitamin D. A non-consanguineous family of Chinese Han origin with one affected individual demonstrating HVDRR was recruited, with the proband evaluated clinically, biochemically and radiographically. To identify the presence of mutations in the VDR gene, all the exons and exon–intron junctions of the VDR gene from all family members were amplified using PCR and sequenced. The proband showed rickets, progressive alopecia, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. She also suffered from epilepsy, which is rarely seen in patients with HVDRR. Direct sequencing analysis revealed a homozygous missense mutation c.122G>A (p.C41Y) in the VDR gene of the proband, which is located in the first zinc finger of the DNA-binding domain. Both parents had a normal phenotype and were found to be heterozygous for this mutation. We report a Chinese Han family with one individual affected with HVDRR. A homozygous missense mutation c.122G>A (p.C41Y) in the VDR gene was found to be responsible for the patient’s syndrome. In contrast to the results of treatment of HVDRR in other patients, our patient responded well to a supplement of oral calcium and a low dose of calcitriol.

1,25(OH)2D3 dependent overt hyperactivity phenotype in klotho-hypomorphic mice

Klotho, a protein mainly expressed in kidney and cerebral choroid plexus, is a powerful regulator of 1,25(OH)₂D₃ formation. Klotho-deficient mice (kl/kl) suffer from excessive plasma 1,25(OH)₂D₃-, Ca²⁺- and phosphate-concentrations, leading to severe soft tissue calcification and accelerated aging. NH₄Cl treatment prevents tissue calcification and premature ageing without affecting 1,25(OH)₂D₃-formation. The present study explored the impact of excessive 1,25(OH)₂D₃ formation in NH₄Cl-treated kl/kl-mice on behavior. To this end kl/kl-mice and wild-type mice were treated with NH₄Cl and either control diet or vitamin D deficient diet (LVD). As a result, plasma 1,25(OH)₂D₃-, Ca²⁺- and phosphate-concentrations were significantly higher in untreated and in NH₄Cl-treated kl/kl-mice than in wild-type mice, a difference abrogated by LVD. In each, open field, dark-light box, and O-maze NH₄Cl-treated kl/kl-mice showed significantly higher exploratory behavior than untreated wild-type mice, a difference abrogated by LVD. The time of floating in the forced swimming test was significantly shorter in NH₄Cl treated kl/kl-mice compared to untreated wild-type mice and to kl/kl-mice on LVD. In wild-type animals, NH₄Cl treatment did not significantly alter 1,25(OH)₂D₃, calcium and phosphate concentrations or exploratory behavior. In conclusion, the excessive 1,25(OH)₂D₃ formation in klotho-hypomorphic mice has a profound effect on murine behavior.

Association between Vitamin D Receptor Gene Polymorphisms with Childhood Temporal Lobe Epilepsy

Vitamin D (VD) is implicated in multiple aspects of human physiology and vitamin D receptor (VDR) polymorphisms are associated with a variety of neuropsychiatric disorders. Although VD deficiency is highly prevalent in epilepsy patients and converging evidence indicates a role for VD in the development of epilepsy, no data is available on the possible relationship between epilepsy and genetic variations of VDR. In this study, 150 controls and 82 patients with temporal lobe epilepsy (TLE) were genotyped for five common VDR polymorphisms (Cdx-2, FokI, BsmI, ApaI and TaqI) by the polymerase chain reaction-ligase detection reaction method. Our results revealed that the frequency of FokI AC genotype was significantly higher in the control group than in the patients (p = 0.003, OR = 0.39, 95% CI = 0.21–0.73), whereas the AA genotype of ApaI SNP was more frequent in patients than in controls (p = 0.018, OR = 2.92, 95% CI = 1.2–7.1). However, no statistically significant association was found between Cdx-2, BsmI and TaqI polymorphisms and epilepsy. Additionally, in haplotype analysis, we found the haplotype GAT (BsmI/ApaI/TaqI) conferred significantly increased risk for developing TLE (p = 0.039, OR = 1.62, 95% CI = 1.02–2.56). As far as we know, these results firstly underline the importance of VDR polymorphisms for the genetic susceptibility to epilepsy.

Vitamin D Deficiency in Children With Newly Diagnosed Idiopathic Epilepsy

Several studies have shown a link between vitamin D deficiency and epilepsy. This study includes 60 newly diagnosed idiopathic epilepsy patients and 101 healthy controls (between the ages of 5 and 16). Each group was also divided into two subgroups according to seasonal changes in terms of months of longer versus shorter daylight. We retrospectively evaluated the levels of calcium, phosphorus, alkaline phosphatase, parathyroid hormone, and 25-OH vitamin-D3 in the study participants. Levels below 20 ng/ml were defined as vitamin D deficiency and levels of 20-30 ng/ml as insufficiency. There were no significant differences in age, gender distribution and levels of calcium, phosphorus, alkaline phosphatase and parathyroid hormone between the groups. The level of 25-OH vitamin-D3 in the patient group was significantly lower when compared to the control group (p < 0.05) (14.07 ± 8.12 and 23.38 ± 12.80 ng/ml, respectively). This difference also held true when evaluation was made according to seasonal evaluation (12.38 ± 6.53 and 17.64 ± 1.14 in shorter daylight and 18.71 ± 9.87 and 30.82 ± 1.04 in longer daylight).

Vitamin D receptor activation induces P-glycoprotein and increases brain efflux of quinidine: an intracerebral microdialysis study in conscious rats

PURPOSE

Since the vitamin D receptor (VDR) was found to up-regulate cerebral P-glycoprotein expression in vitro and in mice, we extend our findings to rats by assessing the effect of rat Vdr activation on brain efflux of quinidine, a P-gp substrate that is eliminated primarily by cytochrome P450 3a.

METHODS

We treated rats with vehicle or the active VDR ligand, 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] (4.8 or 6.4 nmol/kg i.p. every 2nd day × 4) and examined P-gp expression and cerebral quinidine disposition via microdialysis in control and treatment studies conducted longitudinally in the same rat.

RESULTS

The 6.4 nmol/kg 1,25(OH)2D3 dose increased cerebral P-gp expression 1.75-fold whereas hepatic Cyp3a remained unchanged. Although there was no change in systemic clearance elicited by 1,25(OH)2D3, brain extracellular fluid quinidine concentrations were lower in treated rats. We noted that insertion of indwelling catheters increased plasma protein binding of quinidine and serial sampling decreased the blood:plasma concentration ratio, factors that alter distribution ratios in microdialysis studies. After appropriate correction, KECF/P,uu and KECF/B,uu, or ratios of quinidine unbound concentrations in brain extracellular fluid to plasma or blood at steady-state, were more than halved.

CONCLUSION

We demonstrate that VDR activation increases cerebral P-gp expression and delimits brain penetration of P-gp substrates.

Epilepsy treatment by sacrificing vitamin D

Epilepsy is one of the most common neurologic disorders in childhood that often requires long term treatment with antiepileptic drugs. Both antiepileptic treatment and the comorbidities associated with epilepsy have a negative impact on bone health in growing children. Given the fact that vitamin D deficiency is a major public health problem worldwide, clinicians caring for children with chronic diseases should be aware of effects of the medication on the bone metabolism. Yet, vitamin D deficiency due to antiepileptic treatment is an overlooked issue among neurologists. In this review, we briefly describe vitamin D metabolism and the effect of vitamin D in the brain. We also discuss the literature in terms of vitamin D deficiency and antiepileptic treatment in the pediatric population.

Review: the role of vitamin D in nervous system health and disease

Vitamin D and its metabolites have pleomorphic roles in both nervous system health and disease. Animal models have been paramount in contributing to our knowledge and understanding of the consequences of vitamin D deficiency on brain development and its implications for adult psychiatric and neurological diseases. The conflation of in vitro, ex vivo, and animal model data provide compelling evidence that vitamin D has a crucial role in proliferation, differentiation, neurotrophism, neuroprotection, neurotransmission, and neuroplasticity. Vitamin D exerts its biological function not only by influencing cellular processes directly, but also by influencing gene expression through vitamin D response elements. This review highlights the epidemiological, neuropathological, experimental and molecular genetic evidence implicating vitamin D as a candidate in influencing susceptibility to a number of psychiatric and neurological diseases. The strength of evidence varies for schizophrenia, autism, Parkinson's disease, amyotrophic lateral sclerosis, Alzheimer's disease, and is especially strong for multiple sclerosis.

Epilepsy and vitamin D

Several disorders, both systemic and those of the nervous system, have been linked with vitamin D deficiency. Neurological disorders with a vitamin D link include but are not limited to multiple sclerosis, Alzheimer and Parkinson disease, as well as cerebrovascular disorders. Epilepsy which is the second leading neurological disorder received much less attention. We review evidence supporting a link between vitamin D and epilepsy including those coming from ecological as well as interventional and animal studies. We also assess the literature on the interaction between antiepileptic drugs and vitamin D. Converging evidence indicates a role for vitamin D deficiency in the pathophysiology of epilepsy.

Vitamin D, effects on brain development, adult brain function and the links between low levels of vitamin D and neuropsychiatric disease

Increasingly vitamin D deficiency is being associated with a number of psychiatric conditions. In particular for disorders with a developmental basis, such as autistic spectrum disorder and schizophrenia the neurobiological plausibility of this association is strengthened by the preclinical data indicating vitamin D deficiency in early life affects neuronal differentiation, axonal connectivity, dopamine ontogeny and brain structure and function. More recently epidemiological associations have been made between low vitamin D and psychiatric disorders not typically associated with abnormalities in brain development such as depression and Alzheimer's disease. Once again the preclinical findings revealing that vitamin D can regulate catecholamine levels and protect against specific Alzheimer-like pathology increase the plausibility of this link. In this review we have attempted to integrate this clinical epidemiology with potential vitamin D-mediated basic mechanisms. Throughout the review we have highlighted areas where we think future research should focus.

Neonatal seizures: controversies and challenges in translating new therapies from the lab to the isolette

Neonatal seizures have unique properties that have proved challenging for both clinicians and basic science researchers. Clinical therapies aimed at neonatal seizures have proven only partially effective and new therapies are slow to develop. This article will discuss neonatal seizures within the framework of the barriers that exist to the development of new therapies, and the challenges inherent in bringing new therapies from the bench to the bedside. With the European Union and USA creating national collaborative project infrastructure, improved collaborative resources should advance clinical research on urgently needed new therapies for this disorder.

Correction of vitamin D deficiency improves seizure control in epilepsy: a pilot study

There is growing interest concerning the role of vitamin D in various medical conditions such as diabetes and oncological, cardiovascular and central nervous system disorders. Although vitamin D deficiency is known to be highly prevalent among epilepsy patients, only a single study, published nearly forty years ago, assessed the effect of vitamin D on seizure control. Here, we measured serum 25-hydroxy-vitamin D (25(OH)D) levels and normalized it by administration of vitamin D3 in 13 patients with pharmacoresistant epilepsy. To see if vitamin D3 has an impact on seizure frequency, we compared seizure numbers during a 90-day period before and after treatment onset. We found that seizure numbers significantly decreased upon vitamin D3 supplementation. Median seizure reduction was 40%. We conclude that the normalization of serum vitamin 25(OH)D level has an anticonvulsant effect.

Assessing vitamin D in the central nervous system

Epidemiological and experimental evidence suggest that vitamin D deficiency is a risk factor for multiple sclerosis and other autoimmune diseases. The activated form of vitamin D exerts several immunomodulating properties in vitro and in vivo, that could contribute to explain the association with multiple sclerosis. Hypovitaminosis D is also associated with several other neurological diseases that is less likely mediated by dysregulated immune responses, including Parkinson's disease and Alzheimer's disease, schizophrenia and affective disorders, suggesting a more diverse role for vitamin D in the maintenance of brain health. Accordingly, both the vitamin D receptor and the enzymes necessary to synthesize bioactive 1,25-dihydroxyvitamin D are expressed in the brain, and hypovitaminosis D is associated with abnormal development and function of the brain. We here review current knowledge on the intrathecal vitamin D homeostasis in heath and disease, highlighting the need to assess vitamin D in the intrathecal compartment.

Vitamin D, a neuro-immunomodulator: implications for neurodegenerative and autoimmune diseases

It has been known for more than 20 years that vitamin D exerts marked effects on immune and neural cells. These non-classical actions of vitamin D have recently gained a renewed attention since it has been shown that diminished levels of vitamin D induce immune-mediated symptoms in animal models of autoimmune diseases and is a risk factor for various brain diseases. For example, it has been demonstrated that vitamin D (i) modulates the production of several neurotrophins, (ii) up-regulates Interleukin-4 and (iii) inhibits the differentiation and survival of dendritic cells, resulting in impaired allo-reactive T cell activation. Not surprisingly, vitamin D has been found to be a strong candidate risk-modifying factor for Multiple Sclerosis (MS), the most prevalent neurological and inflammatory disease in the young adult population. Vitamin D is a seco-steroid hormone, produced photochemically in the animal epidermis. The action of ultraviolet light (UVB) on 7-dehydrocholesterol results in the production of pre-vitamin D which, after thermo-conversion and two separate hydroxylations, gives rise to the active 1,25-dihydroxyvitamin D. Vitamin D acts through two types of receptors: (i) the vitamin D receptor (VDR), a member of the steroid/thyroid hormone superfamily of transcription factors, and (ii) the MARRS (membrane associated, rapid response steroid binding) receptor, also known as Erp57/Grp58. In this article, we review some of the mechanisms that may underlie the role of vitamin D in various brain diseases. We then assess how vitamin D imbalance may lay the foundation for a range of adult disorders, including brain pathologies (Parkinson's disease, epilepsy, depression) and immune-mediated disorders (rheumatoid arthritis, type I diabetes mellitus, systemic lupus erythematosus or inflammatory bowel diseases). Multidisciplinary scientific collaborations are now required to fully appreciate the complex role of vitamin D in mammal metabolism.

Vitamin D, nervous system and aging

This is a mini-review of vitamin D(3), its active metabolites and their functioning in the central nervous system (CNS), especially in relation to nervous system pathologies and aging. The vitamin D(3) endocrine system consists of 3 active calcipherol hormones: calcidiol (25OHD(3)), 1alpha-calcitriol (1alpha,25(OH)2D(3)) and 24-calcitriol (24,25(OH)2D(3)). The impact of the calcipherol hormone system on aging, health and disease is discussed. Low serum calcidiol concentrations are associated with an increased risk of several chronic diseases including osteoporosis, cancer, diabetes, autoimmune disorders, hypertension, atherosclerosis and muscle weakness all of which can be considered aging-related diseases. The relationship of many of these diseases and aging-related changes in physiology show a U-shaped response curve to serum calcidiol concentrations. Clinical data suggest that vitamin D(3) insufficiency is associated with an increased risk of several CNS diseases, including multiple sclerosis, Alzheimer's and Parkinson's disease, seasonal affective disorder and schizophrenia. In line with this, recent animal and human studies suggest that vitamin D insufficiency is associated with abnormal development and functioning of the CNS. Overall, imbalances in the calcipherol system appear to cause abnormal function, including premature aging, of the CNS.

Benefits of sunlight: vitamin D deficiency might increase the risk of sudden unexpected death in epilepsy

Epilepsy is the most common serious neurological condition and sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Information concerning risk factors for SUDEP is conflicting, but high seizure frequency is a potential risk factor. Additionally, potential pathomechanisms for SUDEP are unknown, but it is very probable that cardiac arrhythmias during and between seizures or transmission of epileptic activity to the heart via the autonomic nervous system potentially play a role. In parallel, studies have shown a link between vitamin D dysfunction and epilepsy. Moreover, several evidences in the literature suggest an association between low vitamin D and seizures, indicating the possibility of anticonvulsant properties of this hormone. Quite interesting, a growing body of data suggests that low vitamin D levels may adversely affect cardiovascular health, directly associated with death from heart failure and sudden cardiac death. In view of the above findings, our research group focused in this review article that SUDEP, at least in some cases, could be related with low vitamin D levels.

Progressive hearing loss in mice with a mutated vitamin D receptor gene

BACKGROUND

Both hypo- and hypervitaminosis D can cause sensorineural hearing loss, and aural symptoms due to vitamin D insufficiency are especially common during gravidity. Hormonal forms of vitamin D regulate transcription by binding with the high-affinity vitamin D receptor (VDR).

OBJECTIVE

To assess the effects of impaired vitamin D action in VDR knockout (KO) mice on hearing, cochlear morphology, and cochlear gene expression.

MATERIALS AND METHODS

Eighteen young male and female mice (10 VDR KO and 8 wild type, WT, < or =6 months old), 33 adult male and female mice (16 VDR KO and 17 WT, between 7 and 14 months old), and 11 aged male and female mice (5 VDR KO and 6 WT, > or =15 months old) on 129S1 genetic background were studied. Auditory thresholds were evaluated by auditory brain stem response. Morphological changes were analyzed using plastic embedding and light microscopy. The expression of key genes (known to play a role in the regulation of cochlear function), and caspase 3 activity, were assessed using immunofluorescent confocal microscopy.

RESULTS

There was a statistically significant difference between the young and the adult groups, and between the adult and aged groups of WT mice. There was also a statistically significant difference between the adult and aged groups in VDR KO mice, and between the young WT group and the young VDR KO group. Spiral ganglion cell loss was observed in the basal turn of adult VDR KO mice, a phenomenon infrequently found in WT mice. Expression of connexin 26, KCNJ10, and transient receptor potential channel vanilloid subfamily 4/6 was not affected by VDR KO-mediated hearing loss. Caspase 3 activation was detected in the spiral ganglion cell and its satellite cells, stria vascularis, spiral ligament fibrocytes, and the organ of Corti in both genotypes. However, the percentage of positive cells and the staining intensity were lower in the VDR KO (compared to the WT) mice.

CONCLUSION

These data suggest that sensorineural hearing loss progressively developed at an earlier age in VDR KO mice. While the fundamental gene expressions in the cochlea were not influenced by VDR mutation, it resulted in decrease of caspase 3 activation, which may be one of the factors underlying accelerating age-related hearing loss observed in VDR KO mice.

Cholecalciferol enhances the anticonvulsant effect of conventional antiepileptic drugs in the mouse model of maximal electroshock

The interactions between cholecalciferol, a precursor of the active form of Vitamin D(3), and conventional antiepileptic drugs (valproate, carbamazepine, phenytoin, and phenobarbital) were studied in the maximal electroshock test in mice. Vitamin D(3) applied i.p. at doses of 37.5 and 75 mug/kg, but not at 18.75 mug/kg, significantly raised the electroconvulsive threshold. Furthermore, cholecalciferol (at its highest subthreshold dose of 18.75 mug) potentiated the anticonvulsant activity of phenytoin and valproate. The action of carbamazepine and phenobarbital was also enhanced by Vitamin D(3), but when it was given at the higher dose of 37.5 mug/kg. Cholecalciferol, antiepileptic drugs, and their combinations did not produce significant adverse effects evaluated in the chimney test (motor coordination) and passive-avoidance task (long-term memory). Cholecalciferol did not significantly increase the brain concentrations of conventional antiepileptics, indicating a pharmacodynamic nature of revealed interactions. Our findings show that cholecalciferol may play an anticonvulsant role in the brain and can influence the efficacy of antiepileptic drugs, at least in experimental conditions.

Neurosteroid hormone vitamin D and its utility in clinical nutrition

PURPOSE OF REVIEW

Vitamin D is a seco-steroid hormone with multiple functions in the nervous system. We discuss clinical and experimental evidence of the role of vitamin D in normal and pathological brain functions, and analyze the relative importance of vitamin D-modulated brain mechanisms at different stages of life. We also outline perspectives for the use of vitamin D in clinical nutrition to prevent or treat various brain disorders.

RECENT FINDINGS

Numerous brain dysfunctions are linked to vitamin D deficits and/or dysfunctions of its receptors. In both animals and humans, vitamin D serves as an important endogenous and/or exogenous regulator of neuroprotection, antiepileptic and anticalcification effects, neuro-immunomodulation, interplay with neurotransmitters and hormones, modulation of behaviors, brain ageing, and some other, less-explored, brain processes.

SUMMARY

Vitamin D emerges as an important neurosteroid hormone in the brain, with a strong potential for age-specific applications in clinical nutrition.

Decreased expression of thyroid receptor-associated protein 220 in temporal lobe tissue of patients with refractory epilepsy

PURPOSE

TRAP220 (thyroid hormone receptor-associated protein) functions as a coactivator for nuclear receptors and stimulates transcription by recruiting the TRAP mediator complex to hormone responsive promoter regions. Thus, TRAP220 enhances the function of thyroid/steroid hormone receptors such as thyroid hormone and oestrogen receptors. This study investigated the expression of TRAP220 mRNA and protein level in epileptic brains comparing with human control.

METHODS

We examined the expression of TRAP220 mRNA and protein levels in temporal lobes from patients with chronic pharmacoresistant epilepsy who have undergone surgery.

RESULTS

Expression of TRAP220 mRNA and protein was shown to be decreased significantly in the temporal cortex of the patients with epilepsy.

CONCLUSIONS

Our work showed that a decrease in TRAP220 mRNA and protein levels may be involved in the pathophysiology of epilepsy and may be associated with impairment of the brain caused by frequent seizures.