Expression Analysis of Vitamin D Signaling Pathway Genes in Epileptic Patients

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.

Cholecalciferol Supplementation Impacts Behavior and Hippocampal Neuroglial Reorganization in Vitamin D-Deficient Rats

Vitamin D deficiency (VDD) is widespread around the world and has been extensively documented to affect various health conditions, including the cognitive functioning of the brain. Serum 25-hydroxylated forms of vitamin D are traditionally used to determine vitamin D status. However, there is now evidence that cholecalciferol activation can occur and be controlled by locally expressed enzymes in the brain. This study aimed to investigate the effects of cholecalciferol supplementation on cognitive function in rats who underwent transient VDD in adulthood. Thirty-six adult Wistar rats were administered paricalcitol (seven doses of 32 ng injected every other day) along with a "vitamin D-free" diet to induce VDD, which was confirmed using a LC-MS/MS serum analysis of the cholecalciferol and 25-hydroxyvitamin D3 levels. Treatment was performed by including 1000 IU/kg and 10,000 IU/kg cholecalciferol in the diet. Cognitive performance was evaluated using the novel object recognition (NOR), Morris water maze (MWM), and radial arm maze (RAM) tests. An immunohistochemical analysis of the brain regions involved in learning and memory was performed by quantifying the neurons, astrocytes, and microglia labelled with anti-neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP), and ionized calcium-binding adaptor molecule 1 (Iba-1) antibodies, respectively. The vitamin D deficient group showed the lowest performance in both the MWM and RAM tests. In contrast, the cholecalciferol-treated groups exhibited a faster learning curve. However, no difference was detected between the groups in the NOR test. On the other hand, differences in the cellular organization of the hippocampus and amygdala were observed between the groups. Cholecalciferol supplementation decreased the density of the Iba-1- and GFAP-labeled cells in the hilus and cornu Ammonis 3 (CA3) regions of the hippocampus and in the amygdala. These results support vitamin D's substantial role in learning and memory. They also highlight that subtle changes of cognitive function induced by transient VDD could be reversed by cholecalciferol supplementation. Further studies are needed to better understand VDD and cholecalciferol's effects on the brain structure and function.

Novel biomarker for predicting sepsis mortality: vitamin D receptor

Objective

There are currently no studies on the role of vitamin D receptor (VDR) levels as a cause of or risk factor for sepsis. We aimed to establish the association between VDR levels and 28-day mortality in critically ill patients with sepsis.

Methods

This prospective cross-sectional observational study included 148 patients diagnosed with sepsis who were treated in the intensive care unit. We measured VDR levels, laboratory characteristics, and health scores and related them to survival.

Results

The 148 patients included 96 survivors and 52 non-survivors, with VDR levels of 1.92 and 1.36 ng/mL, respectively. Baseline VDR was a significant predictor of 28-day mortality, with an area under the curve of 0.778. A low VDR level was significantly associated with lower overall survival in patients with sepsis according to Kaplan–Meier curve analysis. VDR levels were also negatively correlated with lactate, C-reactive protein, acute physiological and clinical health evaluation (APACHE) II and sequential organ failure assessment (SOFA) scores, and disease severity.

Conclusions

VDR levels were associated with high 28-day mortality and negatively correlated with lactate, C-reactive protein, APACHE II and SOFA scores, and disease severity in patients with sepsis. VDR levels can predict poor outcomes in patients with sepsis.

Gene expression profiles of YAP1, TAZ, CRB3, and VDR in familial and sporadic multiple sclerosis among an Iranian population

Alterations in the regulatory mechanisms that control the process of myelination in the nervous system, may lead to the impaired myelination in the Multiple sclerosis. The Hippo pathway is an important mediator of myelination in the nervous system and might contribute to the pathophysiology of MS. This study examined via qPCR the RNA expression of YAP1, TAZ, and CRB3 as the key effectors of the Hippo pathway and also, VDR in the peripheral blood of 35 sporadic, 37 familial MS patients; and also 34 healthy first-degree relatives of the familial MS patients (HFR) and 40 healthy individuals without a family history of the disease (control). The results showed the increased expression of VDR in the sporadic group, as compared to other groups. There was also an increased expression of TAZ in the familial and HFR groups, as compared to the control group. The familial and sporadic patients displayed a significantly lower level of expression of YAP1 in comparison to the HFR group. The increased expression level in the sporadic patients and control group, as compared to the HFR group, was seen in CRB3. We also assessed different clinical parameters and MRI characteristics of the patients. Overall, these findings suggest that Hippo pathway effectors and also VDR gene may play a potential role in the pathophysiology of the sporadic and familial forms of MS. Confirmation of different gene expression patterns in sporadic and familial MS groups may have obvious implications for the personalization of therapies in the disease.

The impact of vitamin D supplementation on VDR gene expression and body composition in monozygotic twins: randomized controlled trial

Vitamin D supplementation is widely used. However, there is no consensus on the use and dosage of this supplement and the existing recommendations arise from studies based on the benefits that this nutrient can facilitate in bones. In addition, individual genetics can influence the response to supplementation, therefore, research involving monozygotic twins aims to reduce these differences in phenotypic responses. The objective of this randomised controlled study is to examine the effect of vitamin D supplementation on body composition and the expression of the vitamin D receptor (VDR) mRNA. An intervention was performed through supplementation with cholecalciferol at the concentration of 2000 IU in 90 healthy adult monozygotic twins (male or female pairs) for 2 months. The findings showed that serum vitamin D concentration increased by 65% and VDR gene expression sixty times (p = 0.001). Changes in body composition parameters were observed regarding body fat and lean mass. Our results indicate that an increase in serum vitamin D concentration may have potential therapeutic implications.

Expression Analysis of lncRNAs in Refractory and Non-Refractory Epileptic Patients

Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in the pathogenesis of neuropsychiatric disorders such as epilepsy. In the current study, we evaluated expression of eight lncRNAs in 80 epileptic patients (40 refractory and 40 non-refractory ones) and 40 normal individual using quantitative real-time PCR. Bayesian regression model showed significant higher expression of UCA1 in both refractory and non-refractory groups compared with controls (posterior beta of relative expression (RE) = 2.03, P value = 0.003, and posterior beta of RE = 4.05, P value < 0.0001, respectively). Besides, expression of UCA1 was higher in non-refractory patients compared with refractory ones (posterior beta of RE = 2.008, P value = 0.019). When repeating statistical analyses in a gender-based manner, differences in expression of UCA1 were significant in all subgroup analyses except for male non-refractory vs. refractory subgroups analysis. Expression levels of NKILA and ANRIL were higher in both refractory and non-refractory groups compared with controls (posterior beta of RE = 1.565, P value = 0.018, and posterior beta of RE = 1.902, P value = 0.006 for NKILA; posterior beta of RE = 1.304, P value < 0.0001, and posterior beta of RE = 1.603, P value = 0.019 for ANRIL, respectively). However, expression levels of these two lncRNAs were not different between refractory and non-refractory groups. Gender-based analysis for these two lncRNAs revealed similar results except for lack of difference in ANRIL expression between male refractory group and controls. Expression of THRIL was significantly lower in both refractory and non-refractory groups compared with controls (posterior beta of RE = - 0.842, P value = 0.044 and posterior beta of RE = - 1.969, P value < 0.0001, respectively). Furthermore, expression of this lncRNA was lower in non-refractory patients compared with refractory ones (posterior beta of RE = - 1.129, P value = 0.002). However, no significant difference was detected between non-refractory and refractory patients either in males or females. The interactions between gender and relative expressions of PACER, DILC, and MALAT1 were significant, so the results were assessed in gender-based manner. In females, expression of DILC was higher in non-refractory patients compared with refractory ones (posterior beta of RE = 0.959, P value = 0.044). Expression of MALAT1 was lower in female non-refractory patients compared with controls and in female non-refractory patients compared with refractory ones (posterior beta of RE = - 1.35, P value = 0.002, and posterior beta of RE = - 0.942, P value = 0.045, respectively). Finally, expression of PACER was higher in refractory patients vs. controls and non-refractory patients vs. controls in both male and female subgroups. However, comparison between non-refractory and refractory patients revealed significant results only among females. Expression of none of the assessed lncRNAs was correlated with age of study participants. There were robust correlations between expression levels of lncRNAs. The most robust correlations were detected between UCA1 and PACER (r = 0.84, P < 0.0001) and between UCA1 and ANRIL (r = 0.75, P < 0.0001). Taken together, our study demonstrated dysregulation of lncRNAs in peripheral blood of epileptic patients and potentiated them as biomarkers for this neurologic condition.

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.

Expression analysis of GRIN2B, BDNF, and IL-1β genes in the whole blood of epileptic patients

Epilepsy is a brain disorder with a global prevalence of 1%. It has been attributed to genetics and environmental factors. Despite efforts to identify the molecular pathology of epilepsy, the underlying mechanism is not understood yet. This study was carried out to compare GRIN2B, BDNF, and IL-1β gene expressions in 50 patients suffering from generalized epilepsy with tonic-colonic seizures and 50 age- and sex-matched healthy subjects using TaqMan Real-time PCR. Our results demonstrated significant upregulation of these genes in people with epilepsy compared with healthy subjects. We also found a positive correlation between GRIN2B and BDNF expression (r²=0.4619, p < 0.0001), BDNF and IL-1β expression (r² = 0.515, p < 0.0001), and GRIN2B and IL-1β gene expressions (r² = 0.666, p < 0.0001) which implies the possibility to estimate the expression level of these genes by assessment of expression of one of them. Considering the results of the previous animal studies which showed upregulation of these genes in brain tissues of epileptic animals, the expression levels of GRIN2B, BDNF, and IL-1β in blood samples might be related to their expression in brain samples. Future studies are needed to assess the role of these genes in the pathogenesis of epilepsy and evaluate whether altered expression of these genes along with imaging methods can facilitate subtyping the epilepsy.

Expression Analysis of CYFIP1 and CAMKK2 Genes in the Blood of Epileptic and Schizophrenic Patients

Schizophrenia and epilepsy are two prevalent neurological disorders with high global burden to the society. Genome-wide studies have identified potential underlying causes for these neurological diseases. In the present case-control study, we have assessed expression of CYFIP1 and CAMKK2 genes in the blood samples of epileptic and schizophrenic patients compared with healthy subjects. A total of 180 subjects including 40 epileptic patients, 50 schizophrenic patients, and 90 healthy individuals participated in the study. Expression of the mentioned genes was measured using TaqMan real-time PCR. The results demonstrated a significant upregulation of CYFIP1 gene expression in epileptic patients (P = 0.029). CAMKK2 was downregulated in female schizophrenic patients compared with female healthy individuals (P = 0.048). These results may provide new insight into the pathogenesis of epilepsy and schizophrenia and suggest these genes as potential therapeutic targets for these neurological disorders. Future studies should evaluate these results in larger cohorts of patients.

The burgeoning role of cytochrome P450-mediated vitamin D metabolites against colorectal cancer

The metabolites of vitamin D₃ (VD3) mediated by different cytochrome P450 (CYP) enzymes, play fundamental roles in many physiological processes in relation to human health. These metabolites regulate a variety of cellular signal pathways through the direct binding of activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Thus, the polymorphisms of VDR and VD3 metabolizing enzymes lead to differentiated efficiency of VD3 and further affect serum VD3 levels. Moreover, VDR activation is demonstrated to inhibit the growth of various cancers, including colorectal cancer. However, excessive intake of vitamin D may lead to hypercalcemia, which limits the application of vitamin D tremendously. In this review, we have summarized the advances in VD3 research, especially the metabolism map of VD3 and the molecular mechanisms of inhibiting growth and inducing differentiation in colorectal cancer mediated by VDR-associated cellular signal pathways. The relationship between VDR polymorphism and the risk of colorectal cancer is also illustrated. In particular, novel pathways of the activation of VD3 started by CYP11A1 and CYP3A4 are highlighted, which produce several noncalcemic and antiproliferative metabolites. At last, the hypothesis is put forward that further research of CYP-mediated VD3 metabolites may develop therapeutic agents for colorectal cancer without resulting in hypercalcemia.