The relationship between the expression patterns of fibronectin and its receptors-α5β1 and αVβ3 integrins and the defect of angiogenesis after cerebral ischemia in aged mice

ObjectiveTo investigate the relationship between the expression patterns of fibronectin(Fn) and its receptors-α5β1 and αVβ3 integrins and angiogenesis after cerebral ischemia in aged mice.MethodsBoth young(2months) and aged(18 months) C57BL6 male mice were subject to middle cerebral artery occlusion. The brain endothelial cells(BECs) proliferation was assessed by using dual-immunofluorescent staning(IF) for Ki67 and CD31 and the vessel density was quantified by counting the number of CD31-positive vessels per field of view. The expression patterns of Fn,α5β1 and αVβ3 on blood vessels was assessed by using dual-IF for CD31/ɑ5,CD31/β3 and CD31/Fn.ResultsThe number of CD31/Ki67 dual-positive cells in the penumbra at day 7 after cerebral ischemia of was significantly lower in the aged mice than in the young mice(4.7±0.8/field,P 0.05). The number of CD31-positive vessels in the penumbra at0.01). Furthermore,the expression of Fn,α5 and β3 on blood vessels in the penumbra at day 7 after cerebral ischemia was significantly lower in age mice than in the young mice(P 0.05).ConclusionsThe cerebral angiogenesis after cerebral ischemia is impaired in the aged stroked mice,which is associated with the low expression of fibronectin and its receptors-α5β1 and αVβ3 integrins on blood vessels.