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Nunez-Figueredo 2014 Brain Res Bull

From Bioblast
Publications in the MiPMap
Nunez-Figueredo Y, Pardo-Andreu GL, Ramirez-Sanchez J, Delgado-Hernandez R, Ochoa-Rodriguez E, Verdecia-Reyes Y, Naal Z, Muller AP, Portela LV, Souza DO (2014) Antioxidant effects of JM-20 on rat brain mitochondria and synaptosomes: Mitoprotection against Ca2+-induced mitochondrial impairment. Brain Res Bull 109:68-76.

» PMID: 25305343

Nunez-Figueredo Y, Pardo-Andreu GL, Ramirez-Sanchez J, Delgado-Hernandez R, Ochoa-Rodriguez E, Verdecia-Reyes Y, Naal Z, Muller AP, Portela LV, Souza DO (2014) Brain Res Bull

Abstract: Because mitochondrial oxidative stress and impairment are important mediators of neuronal damage in neurodegenerative diseases and in brain ischemia/reperfusion, in the present study, we evaluated the antioxidant and mitoprotective effect of a new promising neuroprotective molecule, JM-20, in mitochondria and synaptosomes isolated from rat brains. JM-20 inhibited succinate-mediated H2O2 generation in both mitochondria and synaptosomes incubated in depolarized (high K+) medium at extremely low micromolar concentration and with identical IC50 values of 0.91 μM. JM-20 also repressed glucoseinduced H2O2 generation stimulated by rotenone or by antimycin A in synaptosomes incubated in high sodium-polarized medium at extremely low IC50 values of 0.395 μM and 2.452 μM, respectively. JM-20 was unable to react directly with H2O2 or with superoxide anion radicals but displayed a cathodic reduction peak at −0.71 V, which is close to that of oxygen (−0.8 V), indicating high electron affinity. JM-20 also inhibited uncoupled respiration in mitochondria or synaptosomes and was a more effective inhibitor in the presence of the respiratory substrates glutamate/malate than in the presence of succinate. JM-20 also prevented Ca2+ -induced mitochondrial permeability transition pore opening, membrane potential dissipation and cytochrome c release, which are key pathogenic events during stroke. This molecule also prevented Ca2+ influx into synaptosomes and mitochondria; the former effect was a consequence of the latter because JM-20 inhibition followed the patterns of carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP), which is a classic mitochondrial uncoupler. Because the mitochondrion is considered an important source and target of neuronal cell death signaling after an ischemic insult, the antioxidant and protective effects of JM-20 against the deleterious effects of Ca2+ observed at the mitochondrial level in this study may endow this molecule with the ability to succeed in mitochondrion-targeted strategies to combat ischemic brain damage. Keywords: JM-20, Antioxidan, t Mitochondria, Synaptosomes, Neuroprotector, Brain ischemia, Amplex red

O2k-Network Lab: BR Criciuma Muller AP

Labels: MiParea: Respiration 

Stress:Ischemia-reperfusion  Organism: Rat  Tissue;cell: Nervous system  Preparation: Isolated mitochondria 

Regulation: Calcium  Coupling state: ET  Pathway: N, S  HRR: Oxygraph-2k