PhD Study : Regulation of microRNAs in Type 2 Diabetes Mellitus

Summary

Background to the project:

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are incretin hormones whose primary role is to act as important regulators of glucose-induced insulin secretion (1). Understanding their physiological and/or pathophysiological role in type 2 diabetes mellitus (T2DM) is key to improving treatments (2-3). Recent evidence has linked the effect of incretin hormones to the role of microRNAs (miRNAs) in pancreatic beta cells (4-5). miRNAs are short, non-coding RNAs which regulate gene expression and their aberrant expression has been associated with many diseases, including T2DM (6). However, the mechanisms underlying the functional role of microRNAs in the pathogenesis of T2DM remains poorly understood.

There is some evidence to suggest that expression of several miRNAs are influenced by hormones such as GIP and GLP-1 (7-8), but research into the effects of these hormones on miRNAs is still at a very early stage. Therefore, we propose to investigate if incretins and associated stable forms influence the expression and function of a panel of miRNAs. This will uncover pathways that are important in development of insulin resistance and beta-cell dysfunction, with a view to identifying possible targets for therapeutic intervention and potential biomarkers for diagnosis and monitoring response to treatment.

Experimental Design Objectives:

1. To determine if incretin hormone effects on pancreatic beta cells are mediated through miRNAs.

2. To identify and validate novel targets of selected miRNAs.

3. To establish the role of miRNAs in the pathogenesis of T2DM.

Methodology

The methods outlined below are routinely used in the laboratories of both supervisors and papers featuring similar experimental approaches have been published (2-3, 9-10).

A. In vivo tissue analysis (Objective 1) microRNA analysis will be performed on tissues (pancreas, liver, brain) and blood collected from a rodent model of T2DM (high fat fed mice) which have been treated with incretin peptides.

B. Cell culture and Treatment (Objective 1 & 2) Interesting miRNA candidates from part (A) will be further validated in beta cell in vitro models, using control versus treated mouse (MIN-6), rat (BRIN-BD11) and human (1.1B4) beta cell lines. Effects on insulin release will be measured using insulin radioimmunoassay (RIA) as previously described (2).

C. Functional Analysis of selected miRNA (Objective 2 & 3) The novelty of this work will be increased by in silico analysis to identify potential targets, combined with in vitro analysis to validate predictions.

Skills required of applicant:

*Good Laboratory practical skills

*Good oral and written presentation skills

*Good critical thinking and analytical skills

*Good IT skills

*Good work ethic and ability to work independently

*Experience of data analysis and statistical packages (e.g. SPSS)

References:

1.Gault Diabet Med. 2018;35(1):33-40.

2.Martin et al Biochim Biophys Acta. 2013;1830(6):3407-13.

3.Irwin & Flatt World J Diabetes 2015;10(6):1285-1295.

4.Jacovetti et al J Clin Invest. 2012;122(10):3541-51.

5.Belgardt et al Nat Med. 2015;21(6):619-27.

6.Feng Int J Mol Sci. 2016;17(10)

7.Shang et al 2015;29(9):1243-1253.

8.Wang et al. Biochem Biophys Res Commun. 2015;466(1):33-39.

9.Lynch et al Prostate 2016;76(13):1146-5910.

10.Lynch et al  Prostate 2016;76(7):637-648.

Essential criteria

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.

Desirable Criteria

If the University receives a large number of applicants for the project, the following desirable criteria may be applied to shortlist applicants for interview.

• Experience of presentation of research findings

Funding and eligibility