脂多糖对人单核细胞株THP-1细胞HIF-1α及其靶基因GLUT-1表达的影响

Effects of lipopolysaccharide on expression of hypoxia inducible factor-1α and its target gene GLUT-1 in human monocyte lines THP-1 cells

目的研究脂多糖（LPS）对人单核细胞株THP-1细胞低氧诱导因子-1α（HIF-1α）及其靶基因葡萄糖转运载体-1（GLUT-1）表达的影响。方法以1μg／mLLPS分别处理体外常规培养的THP-1细胞0、2、4、6、8h。采用Western blotting检测THP-1细胞HIF-1α蛋白表达，RT—PCR技术检测HIF-1αmRNA与GLUT-1mRNA表达。以不同浓度的LPS（0、0．01、0．1、1μg／mL）分别刺激THP-1细胞6h，Western blotting检测HIF—1α蛋白表达。结果1μg／mLLPS作用2h时，THP-1细胞的HIF—1α蛋白表达开始增加，4h时显著增加（P〈0．05），6～8h时达高峰（P〈0．01）。0．01μg／mLLPS刺激6h，THP-1细胞的HIF—1α蛋白表达较对照组明显升高（P〈0．05）；当0．1μg／mLLPS和1μg／mLLPS刺激6h时，HIF-1α蛋白表达更高，与对照组相比差异有高度统计学意义（P〈0．01）。提示LPS能够诱导THP-1细胞内HIF—1α蛋白表达，并且呈时间和浓度依赖性。1μg／mLLPS作用2、4、6、8h均能上调THP-1细胞HIF-1α与GLUT-1mRNA水平（P〈0．01），且随时间的延长表达逐渐增加。结论LPS能够促进人单核细胞株THP-1细胞HIF-1α及其靶基因GLUT-1的表达。

Objective To investigate the effects of lipopolysaccharide （LPS） on the expression of hypoxia inducible factor- 1α （HIF-1α） and its target gene glucose transpoter-1 （GLUT-1）in human monocyte lines THP-1. Methods THP-1 cells were stimulated with 1 μg/mL LPS for 0, 2, 4, 6 or 8 h. The expression of HIF-1α protein of THP-1 cells was detected by Western blotting, and RT-PCR was employed to detect the expression of HIF-1α mRNA and GLUT-1 mRNA. THP-1 cells were exposed to different concentrations of LPS （0, 0.01,0.1 and 1 μg/mL） for 6 h, and the expression of HIF-1α protein of THP-1 cells was detected by Western blotting. Results The expression of HIF-1α protein of THP-1 cells began to increase 2 h after being treated with 1 μg/mL LPS, significantly increased after exposure for 4 h （ P 〈 0.05） , and reached the peak during 6 to 8 h in the presence of LPS （P 〈 0.01 ）. The expression of HIF-lct protein of THP-1 cells was significantly higher than that of control group when being treated with 0.01 μg/mL LPS for 6 h （ P 〈 0.05） , and was even higher when being treated with 0.1 μg/mL or 1 μg/mL LPS for 6 h（ P 〈 0.01 ）. LPS induced the expression of HIF-1α protein of THP-1 cells in a time and dose-dependent manner. The expression of HIF-lot mRNA and GLUT-1 mRNA was up- regulated in the presence of 1 μg/mL LPS for 2, 4, 6 and 8 h （P 〈 0.01 ） , and increased with time of exposure. Conclusion LPS can promote the expression of HIF-1α and its target gene GLUT-1 in human monocyte lines THP-1 cells.