Articles by Jonatan Sanchez-Garcia in JoVE
Purification of Transcripts and Metabolites from Drosophila Heads Kurt Jensen1, Jonatan Sanchez-Garcia1, Caroline Williams2, Swati Khare1, Krishanu Mathur1, Rita M. Graze3, Daniel A. Hahn2, Lauren M. McIntyre3, Diego E. Rincon-Limas1,4, Pedro Fernandez-Funez1,4 1Department of Neurology, McKnight Brain Institute, University of Florida, 2Department of Entomology and Nematology, University of Florida, 3Genetics Institute, Department of Molecular Genetics and Microbiology, University of Florida, 4McKnight Brain Institute, Department of Neuroscience, Genetics Institute, Center for Translational Research on Neurodegenerative Diseases, and Center for Movement Disorders and Neurorestoration, University of Florida We describe here the procedures for the extraction and purification of mRNA and metabolites from Drosophila heads. We are applying these techniques to better understand the cellular perturbations underlying neuronal degeneration. These methodologies can be easily scaled and adapted for other "omic" projects.
Other articles by Jonatan Sanchez-Garcia on PubMed
The ER Stress Factor XBP1s Prevents Amyloid-beta Neurotoxicity Human Molecular Genetics. Jun, 2011 | Pubmed ID: 21389082 Alzheimer's disease (AD) is an incurable neurodegenerative disorder clinically characterized by progressive cognitive impairment. A prominent pathologic hallmark in the AD brain is the abnormal accumulation of the amyloid-Î² 1-42 peptide (AÎ²), but the exact pathways mediating AÎ² neurotoxicity remain enigmatic. Endoplasmic reticulum (ER) stress is induced during AD, and has been indirectly implicated as a mediator of AÎ² neurotoxicity. We report here that AÎ² activates the ER stress response factor X-box binding protein 1 (XBP1) in transgenic flies and in mammalian cultured neurons, yielding its active form, the transcription factor XBP1s. XBP1s shows neuroprotective activity in two different AD models, flies expressing AÎ² and mammalian cultured neurons treated with AÎ² oligomers. Trying to identify the mechanisms mediating XBP1s neuroprotection, we found that in PC12 cells treated with AÎ² oligomers, XBP1s prevents the accumulation of free calcium (Ca(2+)) in the cytosol. This protective activity can be mediated by the downregulation of a specific isoform of the ryanodine Ca(2+) channel, RyR3. In support of this observation, a mutation in the only ryanodine receptor (RyR) in flies also suppresses AÎ² neurotoxicity, indicating the conserved mechanisms between the two AD models. These results underscore the functional relevance of XBP1s in AÎ² toxicity, and uncover the potential of XBP1 and RyR as targets for AD therapeutics.
Pulling Rabbits to Reveal the Secrets of the Prion Protein Communicative & Integrative Biology. May, 2011 | Pubmed ID: 21980555 The Prion protein (PrP) is a membrane-tethered glycoprotein that plays a central role in a unique class of neurodegenerative diseases that affect humans and other mammals. Prion diseases have genetic and sporadic origins, but their infectious nature sets them apart from other neurodegenerative disorders. According to the "protein-only" hypothesis, misfolded PrP conformers (prions) are responsible for both spongiform degeneration of the brain and disease transmissibility. Thus, understanding PrP conformational dynamics is key to developing effective therapies. Classic studies showing the different susceptibility to prion disease in mammals have recently found support in structural and transgenic studies with PrP from susceptible (mouse, hamster) and resistant (rabbit, horse, dog) animals. These studies identify key residues in PrP that determine both PrP structure and its propensity to acquire a Î²-structure conformation proposed to be neurotoxic.