Hypoxia specifically promotes the adhesion of pulmonary vascular endothelial cells to monocytes

CHEN Ting; TAN Xiaoling; YANG Chengzhong; LI Manman; YANG Rong

doi:10.13431/j.cnki.immunol.j.20170052

Abstract：To study the adhesion property to monocytes of vascular endothelial cells from pulmonary circulation and systemic circulation under hypoxia condition,we analyzed the adhesion of rat pulmonary artery endothelial cells (RPAEC) and rat aortic endothelial cells (RAEC) to monocyte U937.The experimental rats were divided into six groups:normoxic RPAEC+normoxic U937(CPE+CU),hypoxic RPAEC+normoxic U937 (HPE+CU),hypoxic RPAEC + hypoxic U937(HPE + HU),normoxic RAEC + normoxic U937 (CAE + CU),hypoxic RAEC + normoxic U937(HAE + CU) and hypoxic RAEC + hypoxic U937(HAE + HU).Flow cytometry,fluorescence quantitative analysis and fluorescence microscopy were used to detect the monocyte adhesion state.Flow cytometry analysis showed that the percent of DiI+ cell in HPE+CU group was much higher than that of CPE+CU group (P＜ 0.05),but there had no obvious difference between HPE + HU and HPE + CU groups on the percent of DiI + cell.Interestingly,no significant difference was observed in RAEC adhesion to U937 cell between hypoxic and normoxic conditions.Fluorescence density of cell lysates from the group of HPE + CU was much higher than that from CPE+CU group (P＜0.05),while no difference of the density was existed between HPE+HU and HPE+ CU groups.Similarly,there was no difference in fluorescence density in the cell lysates from RAEC and U937 cell adhesion groups.We further detected the cell adhesion of U937 with hypoxic RPAEC by fluorescence microscope.The results showed that monocyte adhesion rate and endothelial cell adhesion ability were significantly increased in HPE +CU group compared with CPE + CU (P＜0.05).However,no difference was detected between HPE+ HU and HPE+CU groups.In conclusion,hypoxia could specifically promote the adhesion of RPAEC cells to U937 cells,no matter U937 treated with or without hypoxia.