Low Shear Stress Induces Inflammatory Response via CX3CR1/NF-κB Signal Pathway in Human Umbilical Vein Endothelial Cells

Background Cardiovascular disease has become a major cause of death worldwide.Atherosclerosis is the pathological basis of many cardiovascular diseases.It is well established that hemodynamics also play an important role in endothelial cell mediated atherosclerotic development.In the process of inflammatory reaction,the damage of vascular endothelial cells is the initial link,and various factors can cause damage of endothelial cells.The change of shear stress is considered to be one of the important factors.In the body,vascular endothelial cells are constantly exposed to blood flow.Flow conditions critically regulate endothelial cell functions in the vasculature.Shear stress not only influences the endothelial cell morphology,migration,differentiation and proliferation,but also regulates the expression of proteins in the endothelial cells.Reduced shear stress resulting from disturbed blood flow can drive the development of vascular inflammatory lesions and promote the formation of atherosclerosis.In the present study,the objective of our study is the comprehensive identification of CX3CR1/NF-κB signaling pathway involved in low shear stress(LSS)-induced inflammation in HUVECs through protein profiling and cell function experiment.Methods Human umbilical vein endothelial cell was cultured onglass slides and placed in a parallel plate flow chamber.M199 culture medium was used for low laminar shear stress at 4.14 dyn/cm2,2 h for the testing group,CX3CR1 sh-RNA and NF-κB inhibitor PDTC are used to block the effects of CX3CR1 and P65.The expression levels of the protein were determined by western blot analysis.Mononuclear cell adhesion assays and scratch assays are used to detect cell adhesion and migration.Results Western blotting analyses revealed that compared with the controls,there is a significant increase in the expression of CX3CR1,nucleusP65,intercellular adhesion molecule-1(ICAM-1),vascular cell adhesion molecule-1(VCAM-1)and Interleukin-6(IL-6),while the expression of cytosolic P65 and IκB was significantly reduced in human umbilical vein endothelial cells(HUVECs)treated with LSS.CX3CR1 Sh-RNA was use to reveal its effect on LSS-induced inflammation.Further,specific NF-κB P65 inhibitors(PDTC)were used to reveal the downstream NF-κB P65 exclusively involved in LSS-induced inflammation in HUVECs,this effect can be abrogated by CX3CR1 sh-RNA and NF-κB inhibitors.Monocyte adhesion assay and scratch test revealed LSS promotes adhesion of monocytes and migration of cells,this effect can be abrogated by CX3CR1 sh-RNA and NF-κB inhibitors.LSS is involved in the expression of adhesion moleculesand chemokines,which are important for the initiation of endothelial inflammation-related atherosclerosis.Conclusions The activation of CX3CR1/NF-κB signaling pathway induced by low shear stress in endothelial cells may lead to the future therapeutic targets of atherosclerotic inflammation.