Background: Endothelial cells are sensitive to changes in both blood components and mechanical stimuli. Endothelial cells may undergo phenotypic changes, such as changes in adhesion protein expression, under different shear stress conditions. Such changes may impact platelet and monocyte adhesion to endothelial cells. This phenomenon is linked to chronic vascular inflammation and the development of atherosclerosis. In the present study, we investigated the effects of ginkgolide B on platelet and monocyte adhesion to human umbilical vein endothelial cells (HUVECs) under different conditions of laminar shear stress.
Methods: Platelet and monocyte adhesion to endothelial cells was determined by the Bioflux 1000. HUVECs were incubated with ginkgolide B or aspirin for 12 h, and then TNFα was added for 2 h to induce the inflammatory response under conditions of 1 and 9 dyn/cm2 laminar shear stress. The protein expression was analyzed by Western blot.
Results: The number of platelets that adhered was greater under conditions of 1 dyn/cm2 than under conditions of 9 dyn/cm2 of laminar shear stress (74.8 ± 19.2 and 59.5 ± 15.1, respectively). Ginkgolide B reduced the tumor necrosis factor α (TNFα)-induced increase in platelet and monocyte adhesion to HUVECs at 1 and 9 dyn/cm2 of laminar shear stress. In TNFα-treated HUVECs, the number of monocytes that adhered was greater under conditions of 1 dyn/cm2 of laminar shear stress compared with 9 dyn/cm2 (29.1 ± 4.9 and 22.7 ± 3.7, respectively). Ginkgolide B inhibited the TNFα-induced expression of vascular cell adhesion molecule-1(VCAM-1), VE-cadherin, and Cx43 in HUVECs at 1 and 9 dyn/cm2. The expression of these proteins was not different between 1 and 9 dyn/cm2.
Conclusions: Ginkgolide B suppressed platelet and monocyte adhesion under different conditions of laminar shear stress. Moreover, ginkgolide B reduced VCAM-1, VE-cadherin and Cx43 expression in TNFα-treated HUVECs under laminar shear stress. This suggested that ginkgolide B might shed light on the treatment of inflammation in atherosclerosis.
Keywords: Endothelial cells; Ginkgolide B; Platelets; Shear stress; VCAM-1; VE-cadherin.