Cytokines regulate the promoter activities of human growth hormone gene in rat pituitary MtT/S cells / 中国免疫学杂志

ABSTRACT

Objective:To study the effect of interleukin-11(IL-11),ciliary neurotropic factor (CNTF) and transforming growth factor-β (TGF-β) on the hGH gene promoter activity in rat pituitary MtT/S cells and the interaction with pituitary-specific transcription factor Pit-1.Methods:Stable transformed MtT/S cell line which contains hGH gene promoter -484-30 bp and luciferase reporter gene firstly established,then the concentration of GH in the medium and lysate of MtT/S cells and luciferase activities in MtT/S cells were measured after treatment these cells with the above cytokines,the effects of cytokines on secretion and synthesis of GH,and the promoter activity of the hGH gene were observed.Results:The results showed that IL-11(20 nmol/L),CNTF(10 nmol/L) and TGF-β(5 nmol/L) regulated secretion and synthesis of GH,and the luciferase expression in stable transformed MtT/S cells.IL-11 and CNTF had the stimulatory effect,whereas TGF-β had the inhibitory effect.Neither overexpression of Pit-1 nor inhibiting Pit-1 expression affected the regulatory role of these cytokines.Conclusion:IL-11,CNTF and TGF-β regulate the GH production in pituitary MtT/S cell line by regulating the hGH gene promoter activity.Pit-1 may not be involved in these actions.