Effect of tissue inhibitor of metalloproteinases-1 siRNA on endothelial cells injury induced by septic serum / 中华急诊医学杂志

ABSTRACT

Objective To investigate the effect and possible mechanism of tissue inhibitor of Metalloproteinases-l(TIMP-1) siRNA on human umbilical vein endothelial cells injury induced by serum of septic patient.Methods Serum samples were separately collected from septic patients and healthy controls.Human umbilical vein endothelial cells (HUVECs) were randomly divided into blank group (normal culture cells),control group (culture medium with 10％ control serum),septic group (culture medium with 10％ septic serum),negative control group (negative siRNA + 10％ septic serum),and TIMP-l siRNA group (TIMP-1 siRNA + 10％ septic serum).The survival rate of endothelial cells was detected by MTT assay.The levels of matrix Metalloproteinase-9 (MMP-9) and TIMP-1 in supernatant of culture medium were measured by enzyme-linked immunosorbent assay (ELISA).The levels of MMP-9,TIMP-1 and Thrombomoduline (TM) in endothelial cells were examined by Western blot.Results Compared with control group,the cell survival rate of septic group decreased 12 hours after the addition of serum (P＜0.05) and reached minimum 48 hours later.The levels of MMP-9 and TIMP-1 in supernatant of culture medium of septic group significantly increased (P＜0.01).The levels of MMP-9 and TIMP-1 increased in the septic group (P＜0.01),while the level of TM reduced at the same time in septic group (P＜0.01).Compared with septic group,the cell survival rate ofTIMP-1 siRNA group decreased (P＜0.05).The level of MMP-9 in supematant of culture medium of TIMP-1 siRNA group increased (P＜0.05),while the level of TIMP-1 decreased (P＜0.05).The level of MMP-9 increased in TIMP-1 siRNA group (P＜0.01),whereas the levels of TIMP-1 and TM reduced in TIMP-1 siRNA group (P＜0.01).Conclusions TIMP-1 plays a protective role in endothelial cells injury induced by septic serum.