Expression analysis of vitamin D signaling pathway genes in epileptic patients

Vitamin D deficiency has been detected in epileptic patients. Vitamin D hasbeen shown to participate in neuroprotection, brain cell proliferation anddifferentiation. Consequently, vitamin D supplements have been suggested asalternative treatments in epileptic patients. We aimed at assessment ofvitamin D signaling pathway in epileptic patients. In the present study weevaluated vitamin D serum concentration as well as expression of vitamin Dreceptor (VDR) gene and genes encoding for vitamin D activating enzyme 1-alpha-hydroxylase (CYP27B1) and deactivating enzyme 24- hyroxylase(CYP24A1) in epileptic patients compared with healthy individuals. We foundsignificant lower levels of vitamin D in epileptic patients compared withhealthy subjects. Expression analyses showed significant down-regulation ofVDR expression in peripheral blood of epileptic patients compared withhealthy subjects (Relative expression (REx)=0.16, P< 0.001). However, therewas no significant difference in CYP24A1 expression between epilepticpatients and normal subjects. CYP27B1 expression analysis showedsignificant up-regulation in male patients aged between 30 and 40 (REx=5.43,P=0.013). After using two-way ANCOVA for adjusting the effects of sex andage, there was a statistically significant difference in the VDR expressionvalues between patient and control groups.Spearman correlation analysis showed no significant correlation betweengenes expression levels and patients age or vitamin D serum concentrations.However, we found significant correlations between VDR expression levelsand CYP24A1/ CYP27B1 expression levels in epileptic patients.There was also a significant correlation between the expression levels ofCYP24A1 and CYP27B1 (r=0.349 and P=0.001). Our study shows a possiblerole for VDR in the pathogenesis of epilepsy.

Keywords:

Vitamin D , VDR , CYP27B1 , CYP24A1 , Epilepsy