Glucagon-like peptide-1 (GLP-1) is an incertin hormone secreted postprandially from intestinal L-cells with established actions to increase glucose-dependent insulin secretion and reduce appetite [Irwin & Flatt 2015]. Similarly, neurotensin (NT), is a 13 amino acid neuropeptide secreted by pancreatic nerves and enteroendocrine cells in response to a meal, with established effects on energy balance [Khan et al. 2017]. Both peptide hormones have also been shown to possess proliferative actions on pancreatic beta-cells and augment beta-cell function [Irwin & Flatt 2015; Khan et al. 2017].
Thus, there is clear potential for additive or synergistic benefits of these two hormones in obesity-diabetes. In full agreement with this, neurotensin has recently been revealed to synergise with the clinically approved GLP-1 analogue, liraglutide, to help reverse obesity in high fat fed mice [Ratner et al. 2019]. In a related theme, our laboratory has also recently shown clear antidiabetic synergy between other similar gut derived peptide hormones, namely glucose-dependent insulinotropic polypeptide (GIP) and xenin [Martin et al. 2012].
These observations later lead to the development of a single GIP/xenin hybrid peptide capable of simultaneously activating both receptor pathways [Hasib et al. 2017]. Indeed, this novel GIP/xenin hybrid displayed prominent antidiabetic therapeutic potential in rodent models of diabetes [Hasib et al. 2017]. Notably, GIP is the sister incretin of GLP-1, while xenin-25 and neurotensin share considerable homology. Thus, the established GIP/xenin axis [Craig et al. 2018] may be broadly similar to the postulated GLP-1/neurotensin interaction that will be investigated within the current research project. Moreover, given that GLP-1-based treatments are already clinically approved, unlike GIP, the potential therapeutic impact of GLP-1/NT peptides is more credible.
As such, this PhD project will build on initial exciting findings with GLP-1 and neurotensin peptides, akin to previous published work on GIP and xenin from our laboratory, with the possibility of progressing to generation of a GLP-1/NT hybrid peptide that would have considerable therapeutic promise for type 2 diabetes.
Therefore, the core objectives of this PhD research project are:
Applicants should note that Laboratory bench fees of £6,000.00 per annum are required for this self-funded PhD project.
Applicants should hold, or expect to obtain, a First or Upper Second Class Honours Degree in a subject relevant to the proposed area of study.
We may also consider applications from those who hold equivalent qualifications, for example, a Lower Second Class Honours Degree plus a Master’s Degree with Distinction.
In exceptional circumstances, the University may consider a portfolio of evidence from applicants who have appropriate professional experience which is equivalent to the learning outcomes of an Honours degree in lieu of academic qualifications.
If the University receives a large number of applicants for the project, the following desirable criteria may be applied to shortlist applicants for interview.
Craig SL, Gault VA, Irwin N. Emerging therapeutic potential for xenin and related peptides in obesity and diabetes. Diabetes Metab Res Rev. 2018 34(6):e3006.
Hasib A, Ng MT, Gault VA, Khan D, Parthsarathy V, Flatt PR, Irwin N. An enzymatically stable GIP/xenin hybrid peptide restores GIP sensitivity, enhances beta cell function and improves glucose homeostasis in high-fat-fed mice. Diabetologia. 2017 60(3):541-552.
Irwin N, Flatt PR. New perspectives on exploitation of incretin peptides for the treatment of diabetes and related disorders. World J Diabetes. 2015 6(15):1285-95.
Khan D, Vasu S, Moffett RC, Gault VA, Flatt PR, Irwin N. Locally produced xenin and the neurotensinergic system in pancreatic islet function and β-cell survival. Biol Chem. 2017 399(1):79-92.
Ratner C, He Z, Grunddal KV, Skov LJ, Hartmann B, Zhang F, Feuchtinger A, Bjerregaard A, Christoffersen C, Tschöp MH, Finan B, DiMarchi RD, Leinninger GM, Williams KW, Clemmensen C, Holst B. Long-Acting Neurotensin Synergizes With Liraglutide to Reverse Obesity Through a Melanocortin-Dependent Pathway. Diabetes. 2019 68(6):1329-1340.
Submission deadline
Wednesday 1 September 2021
12:00AM
Interview Date
To Be Confirmed
Preferred student start date
To Be Confirmed
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