Vitamin k2 improves endothelial progenitor cells vascular repair in rats dyslipidaemia
Abstract. Background: Vitamin k2 (menaquinone-7) was reported to possess a vascular protective action against atherogenesis through reduction of vascular calcification. Objectives: The present study investigated whether the augmentation of endothelial progenitor cells’ (EPCs) reparative capacity could be an underlying mechanism behind vitamin k2 vasoprotective action, in a rat model of dyslipidaemia. Methods: Forty-five Wistar rats were randomly assigned to normal control (15-rat) or dyslipidaemic rats (30-rat) fed on laboratory show or high fat diet (HFD), respectively. Dyslipidaemic rats were further assigned to receive either vehicle or vitamin k2 (30 mg/kg) 5 days a week, orally for 8 weeks. At the end of the study, lipid profile was assessed. Thoracic aortae were dissected for histopathological examination, immunostaining for detection of EPCs markers; CD133 and vascular endothelial growth factor receptor-2 (VEGFR-2), and b-catenin expression, and for expression of NADPH oxidase4 (NOX4). Vascular function was assessed biologically in-vitro. Results: Vitamin k2supplementation conferred an endothelial protection and anti-atherogenic potential when compared to vehicle treated HFD fed rats. The increase in EPCs numbers appears to play a pivotal role in the vaso-protective action of vitamin K2 that could be mediated by interplay between vascular Wnt/b-catenin signalling and NOX4 expression. Conclusion: 8-week treatment with vitamin k2 increases EPCs count in rats with dyslipidemia and whether continued vitamin k2 supplementation confers sustained EPCs endothelial regeneration warrants further investigation.