Vitamin D3 promotes cerebral angiogenesis after cerebral infarction in rats by activating Shh signaling pathway.

Abstract

This study aims at investigating the neuroprotective role of Vitamin D3 (VitD3) in rats with cerebral infarction and its molecular mechanisms. Male Sprague- Dawley (SD) rats were selected and randomly divided into sham operation group, middle cerebral artery occlusion (MCAO) model group, and VitD3 treatment group. The therapeutic effect of VitD3 was evaluated via neurobehavioral scoring and triphenyltetrazolium chloride (TTC) staining. For the evaluation of VitD3 influence on cerebral blood perfusion, Micro-PET imaging technique was applied. The mRNA levels of vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) gene were detected via Real-Time Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Immunofluorescence staining assay was employed to determine the changes in micro-vessel density. Bromodeoxyuridine (Brdu) assay was used to count the number of new vascular endothelial cells. Protein expressions of key genes in the Shh signaling pathway were detected by Western blotting. Our results showed that VitD3 improved the score of neurological function and decreased the size of cerebral infarction in MCAO rats. VitD3 improved cerebral perfusion in the ischemic area after MCAO. VitD3 up-regulated levels of vascular growth-related factors. VitD3 elevated micro-vessel density after cerebral infarction and promoted the proliferation of vascular endothelial cells in the ischemic cortex. The sonic hedgehog (Shh) signaling pathway in the ischemic cortex of MCAO rats was activated after VitD3 treatment. We showed that VitD3 improves cerebral perfusion and reduces neurological impairment in MCAO rats via activating the Shh signaling pathway.