Scientific Research

Research areas

CEINBIO has focused on elucidating the mechanisms of some oxidative stress associated diseases, with a multidisciplinary approach of chemists, biochemists and physicians. Some research areas include the redox biology of proteins and lipids, nitration mechanisms, mitochondrial oxidative metabolism, biochemical basis of neurodegeneration and inflammation, oxidative injury in hypertension and diabetes, redox metabolism of parasites (Trypanosoma cruzi and Platyhelminthes), design and synthesis of antioxidant, antiatherogenic, antichagasic and neuroprotective drugs. These research areas allow a multidisciplinary approach at different levels, from chemical synthesis and biochemistry to cell and animal models of diseases, associated with oxidative stress and its application to human pathology.

Cytochrome c is key protein on mitochondrial respiration and apoptotic cell death. On the other hand, cytochrome c can elicit a weak peroxidatic activity, which can increase under different conditions (e.g. tyrosine nitration or cardiolipin interaction) that may lead to conformational changes in cytochrome c. This research area focuses in structural studies of such alternative conformations of cytochrome c and its functional consequences.

This research area focuses on the mitochondrial formation of reactive oxygen and nitrogen species, mainly peroxynitrite; nitro-oxidative modifications of mitochondrial proteins, their functional consequences in mitochondrial dynamics, apoptosis and modulation by mitochondrially-targeted antioxidants. Also evaluates the role of nitro-oxidative stress on aconitase modulation of respiratory control in different tissues.

Given the strong evidences that relate mitochondrial dysfunction and nitro-oxidative stress to the development of endothelial dysfunction and atherosclerosis, we investigate the molecular pathways and mechanisms that link these processes. Particularly, we study peroxynitrite production by endothelial cells exposed to various pathophysiological stimuli (leptin, oxidized LDL, hyperglycemia) and their modulation by synthetic antioxidants in cellular and animal models.

We study the mechanisms and kinetics of various biomolecules, particularly, proteins and peptides with reactive oxygen and nitrogen species. Peptides with cytoprotective activity and hydrophobic tyrosine analogs as well as endogenous antioxidants are analyzed.

This research area emphasis on enzymatic mechanisms, substrate specificity and superoxide dismutation kinetics by SOD isoforms. Also analyzes peroxide reduction (hydrogen peroxide, lipid peroxides and peroxynitrite) by peroxiredoxins and ascorbate peroxidases of T. cruzi. The mechanism and kinetics of nitro-oxidative inactivation of these proteins are evaluated.

Having demonstrated the formation of peroxynitrite by activated macrophages during phagocytosis, we propose to quantify the flow of oxidants formed under different stimulus. We investigate their diffusion to the phagosome (using T.cruzi models of infection) and nitro-oxidative modification of the phagocytized targets.

We study the efect of nitro-oxidative stress on the suceptibility to infection by T. Cruzi and its modulation by parasite antioxidant systems.

We evaluate the mechanism that link neuronal death and nitro-oxidative stress in animal and cellular models of neurodegenerative diseases. In particular we are interested in the role of mitochondria and peroxynitrite on cell death.

Our group has synthetized and characterized nitroalkenes derived from free (oleic, linoleic, arachidonic acid) and esterified fatty acids (methylarachidonate) as well as cholesteryl esters (cholesteryl-linoleate) by several methodologies including TLC, HPLC, LC-MS, NMR e IR. Current works involve novel biologically relevant isomers synthesis such as stereospecific enzymatic synthesis of nitroarachidonic acid by cyclo-oxygenase and lipo-oxygenases.

ENOS is synthetized and characterized for the development of preclinical studies to identify a drug candidate towards clinical trials in humans, with the aim of primary prevention of atherosclerosis. The stability, interaction with alpha-TPP followed by biodistribution, toxicity and dosage were analized for the selected compounds.

In addition to various biological protective effects of nitroalkenes already described by our group (vasorelaxation, NO release, etc), we study nitroarachidonic acid interactions with inflammatory response -associated enzymes: COX, LOX, NOX, NOS2. We are interested in determine whether arachidonic acid nitration is capable of divert these enzyme usual signaling pathways, promoting anti-inflammatory response. This area includes the recent study of COX and LOX pathways in human platelets and neutrophils as well as in the mice model of atherosclerosis LDL(R-/-).

This research area analizes whether the arachidonic acid nitration favors the formation of lipoproteic adducts between nitroarachidonic and alpha-synuclein, a protein found in various neurodegenerative processes. We propose that the formation of such electrophilic adducts could have an indirect protective role by means of the attenuation of synuclein aggregation.

The erythrocyte is particularly subject to oxidative stress because of free radical species production on the vascular endothelium under pathological conditions such as hyperglycemia or inflammation. We investigate on the oxidative modifications of enzymatic (particularly peroxiredoxin) and non-enzymatic (e.g.hemoglobin) components and its functional consequences, looking for potential biomarkers of vascular stress.

Cellular compartmentalization delimits and regulates cellular functions. The mechanism of action of free radicals and derived species depends, among other factors, on the ability to permeate biomembranes. We are mainly interested in study the physical and chemical interactions of these species with membranes (lipid peroxidation, membrane protein oxidation).

A variety of methodologies (analytical, histological and inmunohistochemical) has been developed in our laboratory to evaluate and study nitrated lipids, as footprints of anti-inflamatory processes on cellular and in vivo models. These methodologies includes the analysis of atherosclerotic lesions and plasma parameters (vitamin E, TBARS, nitro tyrosine, nitro lipids, LDL oxidation).

This area covers the study of the anti-inflammatory response of nitroalkenes and ENOS in cellular and animal models including macrophages derived from cell lines and extracted from rat spleen subjected to inflamatory processes, as well as the atherosclerosis mice model LDL (R-/-). We empathizes on the evaluation of signaling pathways involved in inflammatory response such as Nrf2, NFkB, fase II enzyme induction, citokines secretion.

Our studies focus on the bioenergetic and metabolic alterations that accompany the induction of cellular senescence by oxidants, genotoxic agents and oncogenes. We are interested in particular in the role of energy and lipid metabolism in the establishment and maintenance of senescence and the senescence associated secretory phenotype.

We evaluate mitochondrial bioenergetics, oxidative metabolism, dynamics and biogenesis of melanoma cells; assessing, in particular, the alterations in mitochondrial function caused by chemotherapy and targeted therapies.