Research
New neurotrophin species: their role in neurodegenerative diseases, aging and pain
The neurotrophins are growth factors required by discrete cell types for survival and maintenance, with a broad range of activities in the nervous system and beyond. In 2006 we have described new species of NGF resulting from posttranslational modification of the mature neurotrophin resulting from nitration of tyrosine residues. Importantly, nitrated NGF form high molecular weight oligomers and display a gain-of-function through interaction with p75NTR. We propose nitrated NGF is formed during inflammation, playing a specific activity in nociception. The aims of the present research are to identify the specific activity of nitrated neurotrophins in different models including inflammatory pain and cornea wound healing and to develop neutralizing antibodies with potential therapeutic application. In collaboration with other groups within the IPM, we also attempt to determine the structural and physicochemical properties of nitrated NGF and characterize the binding to receptors.
Characterization of AbA cells and their pathogenic mechanisms
AbA cells (from aberrant astrocytes) are a new type of glial cells recently isolated by our group from degenerating spinal cord from SOD1G93A rats and mice. These cells display high proliferative potential, inflammatory features and markers of un-differentiated astrocytes. Notably, AbA cells are highly and specifically neurotoxic to neurons, being pathogenic candidates for the progression of neurodegenerative diseases. The biology of AbA is being studied in the context of a collaborative study involving other local institutions. The aim of our research at the IP Montevideo is to characterize the transcriptome and secretome of AbA cells, using microarrays and mass spectrometry technologies respectively. Also, we attempt to identify markers to label these cells in different models of neurodegenerative diseases and to test whether or not these cells exert a pathogenic role.
Development of new vectors for gene therapy targeting neurotrophin receptors
The increasing knowledge in molecular pathology made possible the design of therapeutic strategies based on DNA or RNA delivery. These approaches must be biologically safe and guaranty a phenotypical impact. The most conventional vehicles, the genetically modified viral vectors, still present biosafety concerns. There is a need to explore new non-viral vehicles with low biological risks. The present project proposes the application of modular protein design through the rational combination of multiple functional domains. In particular, we are currently developing recombinant proteins that include functional domains combining neurotrophins motifs (to allow macroendocytosis in neurons and glial cells), RGD motifs, nuclear location signals, endosomal escape fusogenic peptides and basic domains. This research will be performed within the frame of an international collaborative program (leaded by Dr. Antoni Villaverde, UAB, Spain), that has pioneered the design and validation of this type of vectors. We have previously shown that they are able to transfer therapeutic DNA resulting in a therapeutic impact in vivo, with no acute inflammatory reaction. The resulting vehicles will be characterized quantitatively in in vitro models of nervous system through a range of properties including productivity, purification, self-assembly, stability, specificity, toxicity, endosomal escape, nuclear transport, uncoating and gene expression.