Proteomics Analysis of Human Serum from Patients with Aortic Aneurysms

The rupture of abdominal aortic aneurysms (AAA) accounts for 10,000 deaths per annum in the UK alone.Currently, the only treatment is via open surgery or endovascular repair.Since both these surgical approaches carry a high mortality there is a great clinical need for drug based or cell based therapy for this pathology.We hypothesise that patients with AAA will have a unique reportoir of circulating proteins which will allow us to identify new drug targets or new early diagnostic markers.

We will be using a proteomic approach to identify the differences in plasma/serum collected from patients with aortic aneurysms compared to control samples. Proteomics is the large scale study of gene expression at the protein level incorporating structural, interaction and expression proteomics. For this study we will be focusing on expression proteomics. The aim here is to detect and identify all, or a subset of the proteins in a particular sample (e.g. cell, tissue, serum) and find out which of these proteins are present, absent or differentially expressed in a related subject to a specific variation, thus leading to the discovery of new protein markers of disease, so-called ‘biomarkers’ and novel pathophysiological mechanisms for diagnostic/prognostic purposes and of novel targets for drug discovery. We will be utilizing two main technologies; two-dimensional gel electrophoresis (2-DE) and mass spectrometry. Using 2-DE, proteins are separated in the first dimension according to their charge properties (isoelectric point, pI) under denaturing conditions, followed by their separation in the second dimension according to their relative molecular mass by SDS-PAGE. From this study, we hope to identify proteins associated with aneurysm development.

This project will offer the opportunity for someone to learn the art of proteomics and to work in a research environment. The Cardiac Proteomics group within the department of Cardiac and Vascular Sciences is a fully furnished laboratory equipped to perform quantitative proteomic analysis of tissue, cells or body fluid. From sample preparation and quantification to running the two-dimensional gels and bioinformatics, all this is performed in-house, with the mass spectrometry carried out using the facilities in the Biomics centre.

Dr De Souza is a Proteomic Specialist, primarily focusing on cardiac proteomics.

Two-dimensional gel separation of human plasma. Partitioned plasma proteins were separated on pH 4-7 L IPG strips, followed by a 12% SDS polyacrylamide gel. Protein spots were visualized using silver staining.

References

Matt, P., Carrel, T. et al. Proteomics in cardiovascular surgery. J Thorac Cardiovasc Surg. 2007; 133: 210-214

De Souza, A.I., Wait, R. et al. Heat shock protein 27 is associated with freedom from graft vasculopathy after human cardiac transplantation. Circ Res. 2005; 97: 192-198