Adiponectin Inhibits KISS-1 Gene Transcription And Expression Through AMPK And Sp-1 In The Hypothalamic GT1-7 Neurons

Objective: The study was to investigate the effect of adiponectin on KISS-1 mRNA expression and transcription regulation of KISS-1 gene in GT1-7 hypothalamic cells. We also explore the potential signal pathway of adiponectin regulates KISS-1 gene.Methods :( 1) GT1-7 Hypothalamic cells were treated with different concentrations of globular adiponectin (0.1-5 ug/ml), then the levers of KISS1 mRNA were detected by Real-time PCR.(2) The 2-kb PGL3-Kiss1 promoter constructs were transiently transfected into GT1-7 cells. Cells were then treated with adiponectin (1-10 ug/ml), and the luciferase activity was determined using Dual-Luciferase Reporter Assay System (Pormega). (3) KISS-1 gene expression levels were detected after cells were treated with globular adiponectin, AICAR, compound C, or AMPK siRNA. (4) Cells were treated with different concentrations of globular adiponectin (1-10 ug/ml), AICAR, Compound C, AMPKα1-siRNA, then SP1 protein levers were determined by Western blot.Results: (1) KISS1 mRNA expression was inhibited by globular adiponectin (gAd)( 0.1-5 ug/ml) in the GT1-7 hypothalamic cells . (2) The KISS-1 promoter activity was significantly repressed in a time-dependent and concentration-dependent manner.(3) Artificial AMPK activation by AICAR (1mM) resulted in an obviously decrease in KISS1 mRNA expression and promoter activity. Conversly, inhibition of AMPK by compound C, a relatively specific AMPK inhibitor, and AMPKα1-siRNA augmented KISS1 mRNA expression. (4) Global adiponectin and AICAR increased the lever of SP1 protein, however, Compound C and AMPKα1-siRNA decreased SP1 protein levers in the GT1-7 cells.Conclusions: Globular adiponectin (gAd) conspicuously inhibits KISS1 mRNA expression and gene transcription in the GT1-7 Hypothalamic cells. Adiponectin regulates KISS-1 gene expression partly through AMPK and SP1 signal pathway.