三油酸甘油酯对大鼠主动脉血管平滑肌细胞增殖的影响

Effects of glyceryl trioleate on the proliferation of rat aortic smooth muscle cells

摘要:

目的：研究三油酸甘油酯对大鼠主动脉血管平滑肌细胞（rat aortic smooth muscle cells，RASMC）增殖的影响。方法：采用体外细胞培养、油红染色观察细胞形态的变化；MTT法、流式细胞术检测三油酸甘油酯对RASMC增殖的影响。结果：油红染色结果显示三油酸甘油酯使RASMC失去原来长梭形外观，胞体变大；三油酸甘油酯浓度越高变化越明显，2 000 mg/dl已无正常细胞存在。三油酸甘油酯对RASMC增殖的影响与作用时间及三油酸甘油酯的浓度密切相关。在24 h≤125 mg/dl，表现为抑制增殖作用；24 h≥250 mg/dl及48~72 h≤500 mg/dl，表现为促进增殖作用，其中24 h，1 000 mg/dl时增殖率最大约为115.9%，与对照组相比差异有统计学意义（t=-3.74，P=0.002）；48~72 h>500 mg/dl及96~144 h，62.5~2 000 mg/dl表现为抑制增殖作用，其中，48、72 h这2个时间点在2 000 mg/dl的增殖率分别较对照组下降42.7%（t=13.08，P=0.000）和65%（t=129.53，P=0.000），与对照组相比差异有统计学意义。流式周期结果表明，三油酸甘油酯组G0/G1期的百分比较对照组降低，而S期百分比增高。流式凋亡结果为，除了24 h和144 h外，其余各时间点的凋亡率较对照组降低，其中72 h及120 h的凋亡率分别为1.1%（F=14.39，P=0.019），0.7%（F=9.96，P=0.034），与对照组相比差异有统计学意义。另外，细胞增殖与凋亡的变化方向一致。结论：三油酸甘油酯对RASMC增殖的影响是双向的，即在低浓度短时间及高浓度长时间的抑制增殖作用，在中间合适的浓度及时间表现为促进增殖作用；细胞增殖周期试验结果也支持三油酸甘油酯具有一定的促进或抑制大鼠主动脉血管平滑肌细胞增殖作用；高浓度脂质对细胞的直接毒性作用、诱导细胞的增殖或凋亡作用，可能共同参与调控血管平滑肌细胞的数目及功能。

Abstract:

Objective：To investigate the effects of glyceryl trioleate on the proliferation of rat aortic smooth muscle cells（RASMC）. Methods：Cell culture was used in this experiment. Oil red staining was used to observe changes in cell morphology. The proliferation effect of glyceryl trioleate on RASMC was tested by MTT and flow cytometry. Results：Oil red staining results showed that RASMC lost its long fusiform appearance and somata got bigger. The higher the concentration of glyceryl trioleate，the more obvious the changes；no normal cell was existed in glyceryl trioleate with concentration of 2 000 mg/dl. Effects of glyceryl trioleate on the proliferation of RASMC were in time and dose relationship. Glyceryl trioleate inhibited the proliferation of RASMC under the condition of 24 h and ≤125 mg/dl while glyceryl trioleate promoted the proliferation of RASMC under the conditions of 24 h and ≥250 mg/dl as well as 48-72 h and ≤ 500 mg/dl. Glyceryl trioleate reached the highest proliferation rate of 115.9% under the condition of 24 h and 1 000 mg/dl，significantly different from that in control group（t=-3.74，P=0.002）. Glyceryl trioleate inhibited the proliferation of RASMC under the condition of 48-72 h and >500 mg/dl as well as 96-144 h and 62.5-2 000 mg/dl. The proliferation rate decreased by 42.7% and 65% compared with those in control group（t=13.08，P=0.000）（t=129.53，P=0.000） under the condition of 24 h，72 h and 2 000 mg/dl. Flow cycle results revealed that G0/G1-phase percentage reduced in glyceryl trioleate group than in control group while percentage of S-phase increased in glyceryl trioleate group than in control group. Apoptosis percentage decreased in glyceryl trioleate group than in control group in every time point except 24 h and 144 h. The apoptosis rate was 1.1%（F=14.39，P=0.019） and 0.7%（F=9.96，P=0.034） in glyceryl trioleate group，statistically different from those in control group. In addi－tion，the changes of cell proliferation and apoptosis were in the same direction. Conclusion：The effect of glyceryl trioleate on the proliferation of RASMC is bidirectional：low concentration and short time as well as high concentration and long time exhibit inhibit－ing effect while moderate time and concentration exhibit promoting effect. The results of cell proliferation cycle also support the pro－moting or inhibiting effect of glyceryl trioleate on the proliferation of RASMC. The direct cytotoxic effect，induced cell proliferation or apoptosis of high concentration lipids may involved in the regulation of vascular smooth muscle cells number and function.