Effect of insulin-like growth factor 1 and insulin on promoter activity of human ?1(Ⅰ) procollagen gene / 中国免疫学杂志

ABSTRACT

Objective:To study the effect of insulin like growth factor 1 and insulin on the promoter activity of human ?1(Ⅰ) procollagen (COL1A1) gene and the influence of tumor necrosis factor ?(TNF?), interferon ? (IFN?) and interferon ?(IFN?) on the effect Methods:Two deletion constructs,pCOLH0 27 and pCOLH2 5 ,containing portions of 5' flanking region of the gene ( 268～+42 bp and 2 483～+42 bp respectively) ligated to the chloramphenicol acetyltransferase (CAT) reporter gene ,were transiently transfected into human skin fibroblasts The cells were subsequently treated with IGF 1 or insulin, and TNF? or IFN? or IFN? The CAT activity was assessed 24 h after the cytokines added Results:The results showed that 13 nmol/L IGF 1 caused 3 68 fold and 4 04 fold increase in the CAT activity of pCOLH0 27 and pCOLH2 5 respectively and that 2 5 ?mol/L insulin caused 3 69 fold and 3 93 fold increase in the activity of the two plasmids respectively TNF?,IFN? and IFN? reduced IGF 1 or insulin induced promoter activity of pCOLH2 5 Conclusion:IGF 1 and insulin could increase the promoter activity of the human (COL1A1) gene TNF?,IFN? and IFN? could suppress the promoter activity induced by IGF 1 and insulin