低密度脂蛋白诱导动脉平滑肌细胞表达MIP-1α mRNA

Low Density Lipoprotein Induced the Expr ession of MIP-1α mRNA in Aortic Smooth Muscle Cells

目的 探讨天然和氧化低密度脂蛋白 (n LDL ,ox LDL)能否诱导培养的兔主动脉平滑肌细胞表达巨噬细胞炎性蛋白 (MIP) 1αmRNA。方法 将培养的兔主动脉平滑肌细胞暴露于n LDL、ox LDL后 ,分别用原位分子杂交法及逆转录聚合酶链反应 (RT PCR)检测其MIP 1αmRNA的表达。结果 培养的兔主动脉平滑肌细胞能表达低水平的MIP 1αmRNA ,天然及氧化低密度脂蛋白能增强平滑肌细胞表达MIP 1αmRNA ,组间差异有极显著性意义 (P <0 0 1)。结论 n LDL和ox LDL通过诱导平滑肌细胞表达MIP 1α 。

Objective To understand whether native and oxidized low density lipoprotein (n-LDL, ox- LDL) can induce cultured aortic smooth muscle cells (SMCs) to express macrophage inflammatory protein-1α mRNA. Methods LDL was isolated from normal blood donors by density gradient ultracentrifugation, and was oxidatively modified by adding CuCl 2. Af ter a 24 h-exposure of the cultured SMCs to n-LDL and ox-LDL respectively, th e expression of MIP-1α mRNA was determined by in situ hybridization using a MIP-1α cDNA probe, and was detected by RT-PCR as well. Results In situ hybridization revealed that cultured aort ic SMCs could express MIP-1α mRNA at a low level. Both n-LDL and ox-LDL coul d enhance the MIP-1α mRNA expression in SMCs, and the later had a more stronge r effect than the former. Densitometry scans showed that the mean absorbance val ues of SMCs in the control, n-LDL and ox-LDL groups were 0 0379, 0 0814 and 0 1146, respectively. Analysis of variance showed that there was a significant difference among the groups (F=137 4, P<0 01). RT-PCR showed that bot h n-LDL and ox-LDL could enhance the MIP-1α mRNA expression in cultured SMCs as well. Conclusion Both n-LDL and ox-LDL may play an important role in the formation of early atherosclerotic lesions through inducing SMCs to expr ess MIP-1α.