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Browsing Buenos Aires by Author "Bustamante, Juanita"
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    Alcohol hangover induces nitric oxide metabolism changes by impairing NMDA receptor-PSD95-nNOS pathway
    (Elsevier, 2021-5-5) Karadayian, Analía G. ; Bustamante, Juanita ; Lores-Arnaiz, Silvia
    Alcohol hangover is defined as the combination of mental and physical symptoms experienced the day after a single episode of heavy drinking, starting when blood alcohol concentration approaches zero. We previously evidenced increments in free radical generation and an imbalance in antioxidant defences in non-synaptic mitochondria and synaptosomes during hangover. It is widely known that acute alcohol exposure induces changes in nitric oxide (NO) production and blocks the binding of glutamate to NMDAR in central nervous system. Our aim was to evaluate the residual effect of acute ethanol exposure (hangover) on NO metabolism and the role of NMDA receptor-PSD95-nNOS pathway in non-synaptic mitochondria and synaptosomes from mouse brain cortex. Results obtained for the synaptosomes fraction showed a 37% decrease in NO total content, a 36% decrease in NOS activity and a 19% decrease in nNOS protein expression. The in vitro addition of glutamate to synaptosomes produced a concentration-dependent enhancement of NO production which was significantly lower in samples from hangover mice than in controls for all the glutamate concentrations tested. A similar patter of response was observed for nNOS activity being decreased both in basal conditions and after glutamate addition. In addition, synaptosomes exhibited a 64% and 15% reduction in NMDA receptor subunit GluN2B and PSD-95 protein expression, respectively. Together with this, glutamate-induced calcium entry was significant decreased in synaptosomes from alcohol-treated mice. On the other hand, in non-synaptic mitochondria, no significant differences were observed in NO content, NOS activity or nNOS protein expression. The expression of iNOS remained unaltered in synaptosomes and non-synaptic mitochondria. Here we demonstrated that hangover effects on NO metabolism are strongly evidenced in synaptosomes probably due to a disruption in NMDAR/PSD- 95/nNOS pathway.
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    Alcohol hangover: impairments in behavior and bioenergetics in central nervous system
    (Biocell, 2016-4-16) Karadayian, Analía G. ; Bustamante, Juanita ; Lores-Arnaiz, Silvia
    Alcohol hangover (AH) is defined as the temporary state after alcohol binge-like drinking, starting when EtOH is absent in plasma. Results from our laboratory have shown behavioral impairments and mitochondrial dysfunction in an experimental model of AH in mice. Our model consisted in a single i.p. injection of EtOH (3.8 g/kg BW) or saline solution in male and female mice, sacrificing the animals 6 hours after injection. Motor and affective behavior together with mitochondrial function and free radical production were evaluated in brain cortex and cerebellum during AH. Results showed that hangover animals exhibited a significant reduction in neuromuscular coordination, motor strength and locomotion together with a loss of gait stability and walking deficiencies. Moreover, an increment in anxiety-like behavior together with fear-related phenotype and depression signs were observed. In relation to bioenergetics metabolism, AH induced a reduction in oxygen uptake, inhibition of respiratory complexes, changes in mitochondrial membrane permeability, decrease in transmembrane potential, increase in O2•- and H2O2 production and impairment in nitric oxide metabolism. All together our data suggest that the physiopathological state of AH involves behavioral impairments and mitochondrial dysfunction in mouse brain cortex and cerebellum showing the long lasting effects of acute EtOH exposure in CNS.
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    Ketamine effect on intracellular and mitochondrial calcium mobilization
    (Biocell, 2016) Bustamante, Juanita ; Czerniczyniec, Analía G. ; Lores-Arnaiz, Silvia
    The suppressive effects of ketamine on intracellular calcium has been reported in a variety of cells although the mechanisms involved are not well understood. The aim of this work was to evaluate the ketamine effect on the mitochondrial Ca2+ accumulation and the cellular Ca2+ mobilization using FLUO4-AM and flow cytometry. The results showed that mitochondria from ketamine injected animals presented a lower ability to retain calcium at concentrations higher than 20 µM, as compared with controls (saline injected animals). In addition, ketamine showed a significant decreased KCl-induced intracellular calcium concentration. KCl increased calcium influx through cellular depolarization. According to the data presented herein, ketamine presents a clear inhibitory effect on cytosolic Ca2+ transport mechanisms, independently from their action on the calcium channel associated NMDA receptor.
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    Lactic acid transport mediated by aquaporin-9 : implications on the pathophysiology of preeclampsia
    (Frontiers, 2021) Acosta, Lucas Hernán ; Medina, Yollyseth ; Reppetti, Julieta ; Corominas, Ana ; Bustamante, Juanita ; Szpilbarg, Natalia ; Damiano, Alicia E.
    Aquaporin-9 (AQP9) expression is significantly increased in preeclamptic placentas. Since feto-maternal water transfer is not altered in preeclampsia, the main role of AQP9 in human placenta is unclear. Given that AQP9 is also a metabolite channel, we aimed to evaluate the participation of AQP9 in lactate transfer across the human placenta. Explants from normal term placentas were cultured in low glucose medium with or without L-lactic acid and in the presence and absence of AQP9 blockers (0.3 mM HgCl2 or 0.5 mM Phloretin). Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and lactate dehydrogenase release. Apoptotic indexes were analyzed by Bax/Bcl-2 ratio and Terminal Deoxynucleotidyltransferase-Mediated dUTP Nick-End Labeling assay. Heavy/large and light/small mitochondrial subpopulations were obtained by differential centrifugation, and AQP9 expression was detected by Western blot. We found that apoptosis was induced when placental explants were cultured in low glucose medium while the addition of L-lactic acid prevented cell death. In this condition, AQP9 blocking increased the apoptotic indexes. We also confirmed the presence of two mitochondrial subpopulations which exhibit different morphologic and metabolic states. Western blot revealed AQP9 expression only in the heavy/large mitochondrial subpopulation. This is the first report that shows that AQP9 is expressed in the heavy/large mitochondrial subpopulation of trophoblasts. Thus, AQP9 may mediate not only the lactic acid entrance into the cytosol but also into the mitochondria. Consequently, its lack of functionality in preeclamptic placentas may impair lactic acid utilization by the placenta, adversely affecting the survival of the trophoblast cells and enhancing the systemic endothelial dysfunction.