Proteomic characterization of EPCs and CECs "in vivo" from acute coronary syndrome patients and control subjects.

BACKGROUND: Circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) represent two scarce blood populations that are thought to play important roles in tissue vascularization. They have also been proposed as potential markers for more than a dozen pathologies. Moreover, EPCs have arisen as a new therapeutic option for cardiovascular disease. However nowadays there is certain controversy about their roles and a better understanding of EPC biology is required to develop new strategies for forthcoming therapies. METHODS: Flow cytometry analysis was performed on freshly isolated mononuclear cells from control subjects and Acute Coronary Syndrome (ACS) patients. EPCs and CECs for both groups were isolated and quantified. Statistical analyses were performed to test the potential biomarker usefulness of both populations in ACS together with the first "in vivo" proteomic characterizations of these populations. RESULTS: Our results do not show statistical differences in the quantification of CECs and EPCs in control subjects and ACS patients. The proteomic characterization allowed us to identify 673 proteins associated to CECs (389 in controls and 462 in ACS patients), and another 502 proteins in EPCs (350 in controls and 274 in ACS patients). CONCLUSIONS: Our data show the necessity to obtain a more accurate and specific phenotype of CECs and EPCs cells as well as a flow cytometry "golden standard" protocol, before they can be considered useful clinical markers. GENERAL SIGNIFICANCE: The proteomic data suggest a potential effect of ACS in the protein profiles of these cells.

An optimal protocol to analyze the rat spinal cord proteome.

Since the function of the spinal cord depends on the proteins found there, better defing the normal Spinal Cord Proteome is an important and challenging task. Although brain and cerebrospinal fluid samples from patients with different central nervous system (CNS) disorders have been studied, a thorough examination of specific spinal cord proteins and the changes induced by injury or associated to conditions such as neurodegeneration, spasticity and neuropathies has yet to be performed. In the present study, we aimed to describe total protein content in the spinal cord of healthy rats, employing different proteomics tools. Accordingly, we have developed a fast, easy, and reproducible sequential protocol for protein extraction from rat spinal cords. We employed conventional two dimensional electrophoresis (2DE) in different pH ranges (eg. 4-7, 3-11 NL) combined with identification by mass spectrometry (MALDI-TOF/TOF), as well as first dimension protein separation combined with Liquid Chromatography Mass Spectrometry/Mass Spectrometry (LC-MS/MS) to maximise the benefits of this technology. The value of these techniques is demonstrated here by the identification of several proteins known to be associated with neuroglial structures, neurotransmission, cell survival and nerve growth in the central nervous system. Furthermore this study identified many spinal proteins that have not previously been described in the literature and which may play an important role as either sensitive biomarkers of dysfunction or of recovery after Spinal Cord Injury.