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A Novel Antagonist Peptide Reveals a Physiological Role of Insulin-Like Peptide 5 in Control of Colorectal Function

  • Ruslan V. Pustovit
  • , Xiaozhou Zhang
  • , Jamie J.M. Liew
  • , Praveen Praveen
  • , Mengjie Liu
  • , Ada Koo
  • , Lalita Oparija-Rogenmozere
  • , Qinghao Ou
  • , Martina Kocan
  • , Shuai Nie
  • , Ross A.D. Bathgate
  • , John B. Furness
  • , Mohammed Akhter Hossain

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Insulin-like peptide 5 (INSL5), the natural ligand for the relaxin family peptide receptor 4 (RXFP4), is a gut hormone that is exclusively produced by colonic L-cells. We have recently developed an analogue of INSL5, INSL5-A13, that acts as an RXFP4 agonist in vitro and stimulates colorectal propulsion in wild-type mice but not in RXFP4-knockout mice. These results suggest that INSL5 may have a physiological role in the control of colorectal motility. To investigate this possibility, in this study we designed and developed a novel INSL5 analogue, INSL5-A13NR. This compound is a potent antagonist, without significant agonist activity, in two in vitro assays. We report here for the first time that this novel antagonist peptide blocks agonist-induced increase in colon motility in mice that express RXFP4. Our data also show that colorectal propulsion induced by intracolonic administration of bacterial products (short-chain fatty acids, SCFAs) is antagonized by INSL5-A13NR. Therefore, INSL5-A13NR is an important research tool and potential drug lead for the treatment of colon motility disorders, such as bacterial diarrheas.

Original languageEnglish
Pages (from-to)1665-1674
Number of pages10
JournalACS Pharmacology and Translational Science
Volume4
Issue number5
DOIs
Publication statusPublished - 8 Oct 2021

Keywords

  • colon motility
  • GPCR
  • INSL5
  • insulin-like peptide 5
  • relaxin family peptide receptor 4
  • RXFP4

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