Participants

Santiago Lamas and collaborators Santiago Lamas Centro de Biologia Molecular Severo Ochoa CBMSO. CSIC Molecular Pathophysiology of the Vascular Wall

Our work is focused on the understanding of the molecular, biochemical, and cellular mechanisms that underlie the pathology of the vascular wall. This includes the study of the regulation of gene expression by shear stress, oxidative stress and nitrosative stress in endothelial cells and the study of postranslational modifications of proteins relevant to vascular function in the context of pro-inflammatory, pro-atherogenic or pro-oxidative situations.

Functional role of postranslational modifications of proteins induced by oxidative and nitrosative stress in the vascular wall.

The S-nitrosylation of cysteines and nitration of tyrosines appear to be biochemical mechanisms of the response to nitroxidative stress. However, the major challenge remains as to which specific targets are really operative in vivo and to what extent these modifications are responsible for the development of pathophysiological settings. In this regard, through the application of proteomic techniques and mass spectrometry analysis we have identified a group of proteins that undergo S-nitrosylation in endothelial cells. At present we are trying to understand the pathophysiological significance of this post-translational modification in cellular models of endothelial damage and ischemia-reperfusion. We would now like to apply the relevance of this knowledge to in vivo pathophysiological models of disease using animals and patients.

Development of animal models of vascular disease

A crucial event in the development of vascular disease is the balance between extracellular matrix degradation and deposition which ultimately leads to the establishment or resolution of fibrosis. Fibrosis is central to many chronic diseases such as atherosclerosis, cirrhosis, scleroderma or interstitial lung damage. Even when part of the molecular mechanisms leading to it are well known, no clues are available to effectively defer or suppress this process. In order to understand the role of pro-fibrotic and vasoconstrictive agents in vascular damage we are developing a transgenic mouse with conditional and selective expression of TGF-β in endothelial cells with the purpose of understanding the role of the TGF-β-endothelin-1 axis in vascular injury and fibrosis. We are also in the process of identifying novel mechanisms of regulation of the endothelin-1 gene related to postranscriptional regulation, in particular the role of proteins actin as redox sensors.

Contributions to the consortium

Our group is in a position to provide expertise on endothelial cell biology in general terms and on the control of vascular tone by endothelial vasoactive factors in particular. We can offer several cellular models for the study of endothelial cell damage as well as provide experience on the study of reactive oxygen and nitrogen species and their related postranslational modifications. We are currently developing techniques to address the relevance of flow-mediated changes in the redox status of endothelial cells. In addition we are developing animal models for the study of vascular wall fibrosis related to the action of TGF-β and endothelin 1.

Flourescence microscopy

Fluorescence microscopy showing the labeling of endothelial cells with an Smad3 antibody. The left panel shows endogenous expression of Smad3, while the right panel depicts cells overexpressed with the Smad3 protein. The green labeling shows Smad3 labeling after staining with a secondary antibody coupled to FITC. The blue color identifies nuclei with the probe Hoechst 33342

Publications

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