Objective To investigate the expression of transcription factors including nuclear factor-κB （NF-κB） and activator protein-1 （AP-1） in vascular endothelial cells （ECs） in different flow fields， and provide experimental evidence for mechanical signal effects on gene regulation pattern of ECs. Methods Cultured human umbilical vein ECs were loaded into steady flow chambers of laminar flow or turbulent flow and observed at 6 time points （0.5 h， 1 h， 2 h， 3 h， 4 h and 5 h） based on different load time. Spacial and temporal characteristics of NF-κB and AP-1 expression in ECs in different flow chambers were detected at a protein level by laser confocal microscope. Results In laminar flow， NF-κB expression rose to peak at 1 hour （26.49±1.63， P＜0.05）and then declined. In turbulent flow， NF-κB expression rose to peak at 3 hours （34.41±6.43， P＜0.05）. In laminar flow， c-Jun/AP-1 expression was transiently elevated， reached its peak at 0.5 hour （18.95±5.38，P＜0.05）and then fell to its baseline level. In turbulent flow， c-Jun/AP-1 expression rose slowly but steady to peak（P＜0.05） . Conclusion The effects of turbulent flow on NF-κB and AP-1 expression in ECs are different from those of laminar flow. Up-regulation and activation of NF-κB and AP-1 expression in ECs induced by turbulent flow may cause pathological changes in morphological structure and functional behavior of ECs.
Objective To investigate the influence of RNA interference targeting c-Jun gene on the proliferation of rat vascular smooth muscle cells (VSMCs). Methods The experiment was performed with c-Jun siRNA （c-Jun siRNA group）, control reverse sequence siRNA (control siRNA group) or no siRNA (control group). VSMCs were transfected with siRNA targeting c-Jun gene by liposome. Effects of c-Jun siRNA on mRNA and protein expressions of c-Jun were examined by RT-PCR analysis and Western blot respectively. MTT test and 3H-TdR incorporation were used to detect VSMCs proliferation. Cell cycle analysis of VSMCs in vitro was determined by flow cytometer. Results The expression levels of mRNA and protein of c-Jun in c-Jun siRNA group were significantly lower than those in control group （P＜0.05， P＜0.01). There was no significant difference between control group and control siRNA group （Pgt;0.05）. Proliferation activity of VSMCs decreased significantly in c-Jun siRNA group compared with that in control group （P＜0.05） and VSMCs was blocked in the G0/G1 phase of cell cycle significantly （P＜0.05）. There was no significant difference between control group and control siRNA group （Pgt;0.05）. Conclusion c-Jun gene silenced by RNA interference can inhibit VSMCs proliferation effectively in vitro.