The Effect
of Cytokines on Expression of Growth Hormone Gene
in Rat Pituitary GH3 Cells
GONG Feng-Ying, DENG
Jie-Ying*, SHI Yi-Fan, ZHANG Dian-Xi
( Department of Endocrinology, Peking Union Medical College
Hospital, Chinese Academy Medical Sciences & Peking Union Medical College,
Beijing 100730, China )
Abstract To study the effect of interleukin-11 (IL-11),
ciliary neurotropic factor (CNTF) and transforming growth factor-b (TGF-b) on the hGH gene promoter
activity in rat pituitary GH3 cells and the interaction with pituitary-specific
transcription factor Pit-1, firstly the stable transformed GH3 cell line which
contained hGH gene promoter –484 to 30 bp and luciferase reporter gene
was established, then the concentration of GH in the medium and lysate of GH3
cells and luciferase activities in GH3 cells were measured, after treating
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. The
results of our experiments showed that IL-11 (20 nmol/L), CNTF (10 nmol/L) and
TGF-b (5 nmol/L) regulated secretion and synthesis of GH, and the
luciferase expression in stable-transformed GH3 cells. IL-11 and CNTF had a
stimulatory effect, whereas TGF-b had an inhibitory one. Neither
overexpression of Pit-1 nor inhibition of Pit-1 expression could affect the
regulatory role of these cytokines. In conclusion, IL-11, CNTF and TGF-b regulated the GH production
in pituitary GH3 cell line by regulating the hGH gene promoter activity,
while Pit-1 might not be involved in the roles.
Key
words
cytokine; hGH gene promoter; GH3 cells; Pit-1 protein
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