MALDI Imaging Mass Spectrometry to validate novel transgenic mouse models lacking melanocortin peptide hormones

Project Code: 10467818

Faculty: Faculty of Medical and Health Sciences

Department: Physiology

Main Supervisor: Dr Kathy Mountjoy

Application open date: 09 Sep 2020

Application deadline: 28 Feb 2022

Enrolment information: NZ Citizens, NZ Permanent Residents

Introduction

Multiple melanocortin peptides in the pituitary and brain are some of the most important hormones involved in the regulation of stress, body weight, obesity, type-2 diabetes and neurological disorders. Despite these pivotal roles, very little is known about which of the specific roles for brain or pituitary derived melanocortin peptide hormones. We hypothesise that specific melanocortin peptides produced from brain and pituitary work together regulating diverse physiological responses. Specific functions for pituitary and brain melanocortin peptides are currently not understood. Here, we will utilise the specificity and sensitivity of imaging mass spectrometry to detect, map and quantify endogenous melanocortin peptide hormones in mouse pituitary and brain sections

 

What we are looking for in a successful applicant

Seeking students with a passion for biomedical research. There are opportunities for Masters students to continue this research project at the PhD level.

Objective

This project will apply state-of-the-art MALDI imaging mass spectrometry technology to identify, map, and quantitate POMC cleavage products through mouse pituitary and brain. MALDI imaging mass spectrometry is a proteomic technique that combines the specificity and sensitivity of mass spectrometry with spatial information to map tissue-wide distribution of multiple analytes simultaneously, directly from a single tissue section. A standard curve-based quantitative approach was used to generate proof-of-principle absolute quantitative MALDI images of POMC-derived peptides. Unique transgenic mouse models that lack specific melanocortin peptides either in the brain or in pituitary are being developed by a collaborator in Dallas, Texas. Frozen tissues will be sent to NZ and melanocortin peptide expression will be validated in this project using MALDI imaging mass spectrometry.

This study will advance knowledge on how the natural melanocortin system regulates appetite and body weight. This knowledge could eventually lead to effective therapies for today’s obesity epidemic.

Other information

Skills taught:

·         Cryostat cutting thin pituitary and brain sections from frozen tissue

·         Histology: haematoxylin and eosin staining

·         Light microscopy and documentation of capture images

·          MALDI imaging mass spectrometry

·          Proteomic data searching

 

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