Protective Effects of Astragalus Membranaceus and Ligustrazine on Rat Brain Microvascular Endothelial Cell Injury after Oxygen-Glucose Deprivation/ Reoxygenation by Suppressing the PKCδ/MARCKS Pathway.

Abstract

Cell death is a main pathological change in brain ischemia. Astragalus membranaceus (Ast) and ligustrazine (Lig), as traditional Chinese herbs, have a protective effect against ischemia-reperfusion injury. We aim to find whether the underlying protective mechanism of Astragalus membranaceus and ligustrazine against Oxygen-glucose deprivation/reoxygenation (OGD/R) -induced injury in RBMECs is related to PKCδ/MARCKS pathway. OGD/R preconditioning was instituted in rat brain microvascular endothelial cells (RBMECs). The survival and apoptosis of RBMECs were detected by a Cell Counting Kit-8 and TUNEL staining; PKCδ/MARCKS and MMP9 expression were examined by immunofluorescence, western blot and quantitative real-time PCR. OGD/R stimulation significantly increased RBMEC apoptosis, whereas Ast+Lig, Rottlerin or Ast+Lig+Rottlerin treatment evidently reduced cellular apoptosis and increased cell viability (P <0.05). Furthermore, Ast+Lig, Rottlerin or Ast+Lig+Rottlerin treatment significantly reduced mRNA expression levels of PKCδ/MARCKS and MMP9 (P <0.05), compared to OGD/R control group. Moreover, Ast+Lig, Rottlerin or Ast+Lig+Rottlerin treatment evidently reduced protein expression levels of PKCδ, MMP9, and MARCKS (P <0.05), compared to OGD/R control group, detected by western blotting or immunofluorescence. The administration of Astragalus membranaceus and ligustrazine protected RBMECs against OGD/R-induced apoptosis. PKCδ/MARCKS and MMP9 expression were significantly increased after OGD/R stimulation, while Astragalus membranaceus and ligustrazine treatment evidently suppressed. Collectively, Astragalus membranaceus and ligustrazine play protective effects against OGD/R-induced injury in RBMECs through regulating PKCδ/MARCKS pathway to inhibit MMP9 activation.