OBJECTIVETo study the effect of inflammatory factors on cell proliferation and apoptosis in insulin-like grown factor 1 (IGF1)-slienced human coronary artery smooth muscle cells (hCASMCs).

METHODSWe silenced the expression of IGF1 in hCASMCs using the lentivirus-mediated RNA interference technology. Blank control group and negative control group were set using the hCASMCs without the infection of a virus vector and the hCASMCs with the infection of a negative control virus vector, respectively. After the treatment of these cells with both tumor necrosis factor-α 50 ng/ml and interleukin-1β 40 ng/ml, the concentration of IGF1 in cell-culture medium was detected by enzyme-linked immunosorbent assay, and the proliferation and apoptosis were evaluated by MTT assay and flow cytometry.

RESULTSAfter the simulation with inflammatory factors, the concentration of IGF1 in the supernatant fluid of cultured IGF1-slienced hCASMCs was significantly lower than those in the blank control group and negative control group [(426.35±120.96) vs. (1 030.69±54.69) and (992.82±26.90)pg/ml, P=0.000). The proliferation of IGF1-slienced hCASMCs was substantially much less than the two control groups (0.302±0.011 vs. 0.401±0.028 and 0.302±0.011, F=37.628, P=0.000), and the apoptosis rate of IGF1-slienced hCASMCs was significant increased compared with the other two groups [(10.57±0.99)% vs. (0.19±0.13)% and (1.31±0.30)%, P=0.001].

CONCLUSIONInflammatory factors can inhibit the cell proliferation and promote apoptosis after the knock-down of IGF1 in hCASMCs.