Selected ongoing research projects
The goal of the Unit of Proteomics is to develop new, generally applicable technologies for proteomic analysis for generating new discoveries in specific areas of cardiovascular research using a synergistic combination of contemporary two-dimensional gel electrophoresis, a well established mass spectrometry facility, and state-of-the-art methods of biochemistry and gene expression/regulation analysis.
Several proteomic approaches have been recently applied by the Unit of Proteomics to the study of: a) plasma; b) circulating cells; c) circulating mediators (lipoprotein, microparticles); d) secreted proteins (secretome); e) cell cultured systems; f) tissues; and g) organelles in the search for new mechanistic or diagnostic biomarkers for cardiovascular diseases.
The incorporation of proteomic analysis of plasma into functional biochemical and biological approaches provides a powerful mean of identifying patho/physiological pathways in cardiovascular diseases as it allows the simultaneous detection of different circulating proteins and their post-translational modifications that cannot be identified by conventional measurements. We applied this approach to the investigation of the complex network of molecular mechanisms involved in the deleterious effects of coronary artery bypass graft (CABG) surgery and in coronary artery disease (CAD).
Circulating cells represent an important target of proteomics because they can bear information reflecting directly an inflammatory or pro-coagulant state related to the pathology. We focused on the analysis of platelets whose participation in the genesis of chronic atherosclerotic lesions and the formation of thrombi that acutely occlude arteries, causing serious disease, is now well established.
- Circulating mediators: lipoprotein and microparticles
The mechanisms by which human low density lipoprotein LDL manifests its atherogenic properties have been, indeed, the topic of intense investigation during the past decades but, still, few data have been reported on proteins contained in human LDL and their possible functional roles. Our proteomic analysis revealed the presence of proteins not previously described to reside in LDL, including prenylcysteine lyase (PCL1), orosomucoid, retinol-binding protein, and paraoxonase-1. Of interest, PCL1, an enzyme crucial for the degradation of prenylated proteins, generates free cysteine, isoprenoid aldehyde and hydrogen peroxide. The integration of the proteomic data with biochemical and gene expression analysis allowed us to assess that PCL1 is generated along with nascent lipoprotein and that it can itself generate an oxidant, thus suggesting that PCL1 may play a significant role in atherogenesis.
The secretome recently emerged as a new term to describe the global study of proteins that are secreted by a cell at any given time or under certain conditions, constitutes an important class of proteins that control and regulate a multitude of biological and physiological processes, thus making it a clinically relevant source for biomarkers and therapeutic target discoveries. In this respect, the application of a global proteomic approach to determine the effect of statins on the proteins released, “secretome”, by endothelial cells, could help to understand novel mechanisms by which statins promote some of their beneficial effects.
- The unexplored human mitral valve prolapse proteome
This translational research program is aimed to investigate the cellular and molecular regulators of tissue remodeling during the development of human Myxomatous Mitral Valve Prolapse (MVP), the most common indication for mitral valve surgery due to severe mitral regurgitation merging proteomics and cellular biology approaches. Echocardiographically,
Focusing on specific organelle proteomes affords an attractive alternative to reduce the tremendous complexity of the cellular/tissue proteomes and represents an attainable goal for better spatial and functional correlations of the identified proteins.
- The Italian MT-HPP Initiative
The mitochondrial Human Proteome Project (mt-HPP) is a Human Proteome Organization (HUPO) initiative led by the Italian Proteomics Association (ItPA), focused on human mitochondrial proteins. Due to the intrinsic nature of the mitochondrial proteome, this action is part of both the chromosome-centric Human Proteome Project (c-HPP) and the Biology/Disease Human Proteome Project (B/D-HPP). The main goal of this effort is to obtain robust information about the integrative role of proteins acting at the mitochondrial level, considering both those encoded by the mitochondrial DNA (mt-DNA) and by the nuclear DNA. The project is conducted with the support of HUPO and under supervision of external advisors (Peipei Ping, University of California Los Angeles; Mohano Babu, University of Regina, Canada).
- Proteomic analysis of in vitro cell systems
In the context of cellular proteome we are currently interested in the cellular phenotyping following gene silencing by RNAi. We are currently exploring the inhibition effect of the Tissue Factor (TF) expression by its specific siRNA in cardiomyocytes.