Analysis of molecular events associated with adult rat dorsal hippocampus demyelination following treatment with vitamin D3

Abstract

Demyelination is the pathological hallmark of multiple sclerosis (MS) lesions. Considering the involvement of hippocampus in MS, we aim to evaluate the effect of vitamin D3 on molecular events in the dorsal hippocampus (CA1 area) following the induction of experimental demyelination in rats. All experiments were carried out on adult male Wistar rats. For demyelination induction, 2 μL lysophosphatidyl choline (LPC) was injected into the CA1 area of rat brain using stereotaxic surgery. Animals were treated with vitamin D3 dissolved in sesame oil at doses of 5 μg/kg intra-peritoneally for 7, 14 and 21 days post receiving LPC. The hippocampus tissue was then removed to measuring the expression of Olig2 (marker of OPCs), GFAP (marker of astrocyte) and Nogo-A (axonal growth inhibitor) genes into lesion. RT-PCR analysis indicated that following hippocampus demyelination Olig2, GFAP and Nogo-A genes expression were significantly increased on days 7, 14 and 21 post lesion. While administration of vitamin D3 for 7, 14 and 21 days post lesion significantly caused a decrease in Olig2, GFAP and Nogo-A genes expression. Our results indicated the positive effect of vitamins D3 on process of remyelination by enhancing oligodendrocyte precursors’ recruitment and decreasing of inhibitory genes such as Nogo-A and GFAP in the context of demyelinating diseases like MS.