Endocrine

, Volume 21, Issue 2, pp 185–195

A peptide derived from the human leptin molecule is a potent inhibitor of the leptin receptor function in rabbit endometrial cells

Authors

    • Boston Biomedical Research Institute (BBRI)
  • Paul C. Leavis
    • Boston Biomedical Research Institute (BBRI)
    • Department of PhysiologyTufts University School of Medicine
Article

DOI: 10.1385/ENDO:21:2:185

Cite this article as:
Gonzalez, R.R. & Leavis, P.C. Endocr (2003) 21: 185. doi:10.1385/ENDO:21:2:185

Abstract

In this article we show that rabbit endometrial cells express leptin receptor and that human leptin triggers phosphorylation of signal transducer and activator of transcription 3 and up-regulates the expression of interleukin-1 receptor type I as was previously found in human endometrial cells. Interestingly, leptin also upregulates the secretion of leukemia inhibitory factor and expression of its receptor by rabbit endometrial cells. Analysis of a structural model of the leptin-leptin receptor complex suggested that helices I and III of the human leptin structure were likely sites of interaction with the cytokine binding domain of leptin receptor. Accordingly, we synthesized a peptide (LPA-2) comprising helix III (residues 70–95) and investigated its ability to inhibit leptin receptor function. The effects of LPA-2 were assayed in rabbit endometrial cells, and an antileptin receptor antibody and a scrambled version of LPA-2 were used as positive and negative controls, respectively. LPA-2 binds specifically and with high affinity (Ki ∼ 0.6×10−10M) to leptin receptor and is a potent inhibitor of its functions in rabbit endometrial cells. Because leukemia inhibitory factor and interleukin-1 have been implicated in embryo implantation, our results raise the possibility that the LPA-2-induced inhibition of leptin receptor may be exploited to study the actions of leptin in endometrium and in other tissues under conditions characterized by abnormal leptin production.

Key Words

Leptin peptide antagonistleptin receptorinterleukin 1leukemia inhibitory factorendometrial receptivityimplantation

Copyright information

© Humana Press Inc 2003