Abstract:

Objective   To investigate the effect of epidermal growth factor (EGF)-like domain 7 (EGFL7) of human umbilical vein endothelial cells (HUVEC) on apoptosis of cocultured human aortic smooth muscle cells (AoSMC) and its signal transduction pathway. Methods   HUVEC and AoSMC were co-cultured in cell co-culture pools. The special siRNA targeting EGFL7 was transfected into HUVEC by lipofectamine, irrelevant siRNA as the negative group(neg) and siRNA-nontransfected cells as the control group(con).When the Egfl7 gene was silenced in HUVEC, AoSMC cell survival rates were determined by MTS, LDH, ATP and Caspase-3 release amount by spectrophotometry, and Bcl-2 and bax expressions in AoSMC by RT-PCR. Results   AoSMC survival rates decreased significantly after 24,36 and 48 hours（P<0.05）. There were significant differences in ATP release amount, LDH content in medium and Caspase-3amount at 12, 24, 36 and 48 hours（P<0.05）. The bcl-2 expression was gently reduced and there were significant differences at 24, 36 and 48 hours compared with the control and negative group（P<0.05）. While there was no significant difference in the bax expression（P>0.05）. Conclusion   The silence of EGFL7 in HUVEC could promote apoptosis of AoSMC. EGFL7 may regulate apoptosis of SMC via Bcl-2-related signal pathway.

Key words: Epidermal growth factorlike domain 7; RNA interference; Smooth Muscle Cell; Apoptosis; Atherosclerosis