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Benavides S, Palavecino R, Riquelme JA, Montecinos L, Finkelstein JP, Donoso P, Sánchez G. Inhibition of NOX2 or NLRP3 inflammasome prevents cardiac remote ischemic preconditioning. Front Physiol 2024; 14:1327402. [PMID: 38288352 PMCID: PMC10822933 DOI: 10.3389/fphys.2023.1327402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/20/2023] [Indexed: 01/31/2024] Open
Abstract
Introduction: Short episodes of ischemia-reperfusion (IR) in the heart (classical ischemic preconditioning, IPC) or in a limb (remote ischemic preconditioning, RIPC) before a prolonged ischemic episode, reduce the size of the infarct. It is unknown whether IPC and RIPC share common mechanisms of protection. Animals KO for NOX2, a superoxide-producing enzyme, or KO for NLRP3, a protein component of inflammasome, are not protected by IPC. The aim of this study was to investigate if NOX2 or NLRP3 inflammasome are involved in the protection induced by RIPC. Methods: We preconditioned rats using 4 × 5 min periods of IR in the limb with or without a NOX2 inhibitor (apocynin) or an NLRP3 inhibitor (Bay117082). In isolated hearts, we measured the infarct size after 30 min of ischemia and 60 min of reperfusion. In hearts from preconditioned rats we measured the activity of NOX2; the mRNA of Nrf2, gamma-glutamylcysteine ligase, glutathione dehydrogenase, thioredoxin reductase and sulfiredoxin by RT-qPCR; the content of glutathione; the activation of the NLRP3 inflammasome and the content of IL-1β and IL-10 in cardiac tissue. In exosomes isolated from plasma, we quantified NOX2 activity. Results: The infarct size after IR decreased from 40% in controls to 9% of the heart volume after RIPC. This protective effect was lost in the presence of both inhibitors. RIPC increased NOX2 activity in the heart and exosomes, as indicated by the increased association of p47phox to the membrane and by the increased oxidation rate of NADPH. RIPC also increased the mRNA of Nrf2 and antioxidant enzymes. Also, RIPC increased the content of glutathione and the GSH/GSSG ratio. The inflammasome proteins NLRP3, procaspase-1, and caspase-1 were all increased in the hearts of RIPC rats. At the end of RIPC protocol, IL-1β increased in plasma but decreased in cardiac tissue. At the same time, IL-10 did not change in cardiac tissue but increased by 70% during the next 50 min of perfusion. Conclusion: RIPC activates NOX2 which upregulates the heart's antioxidant defenses and activates the NLRP3 inflammasome which stimulates a cardiac anti-inflammatory response. These changes may underlie the decrease in the infarct size induced by RIPC.
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Affiliation(s)
- Sandra Benavides
- Physiopathology Program, Institute of Biomedical Sciences, School of Medicine, Universidad de Chile, Santiago, Chile
| | - Rodrigo Palavecino
- Physiopathology Program, Institute of Biomedical Sciences, School of Medicine, Universidad de Chile, Santiago, Chile
| | - Jaime A. Riquelme
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
- Interuniversity Center for Healthy Aging, Santiago, Chile
| | - Luis Montecinos
- Physiology Program, Institute of Biomedical Sciences, School of Medicine, Universidad de Chile, Santiago, Chile
| | - José Pablo Finkelstein
- Physiology Program, Institute of Biomedical Sciences, School of Medicine, Universidad de Chile, Santiago, Chile
| | - Paulina Donoso
- Physiology Program, Institute of Biomedical Sciences, School of Medicine, Universidad de Chile, Santiago, Chile
| | - Gina Sánchez
- Physiopathology Program, Institute of Biomedical Sciences, School of Medicine, Universidad de Chile, Santiago, Chile
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Sánchez G, Chalmers S, Ahumada X, Montecinos L, Olmedo I, Eisner V, Riveros A, Kogan MJ, Lavandero S, Pedrozo Z, Donoso P. Inhibition of chymotrypsin-like activity of the proteasome by ixazomib prevents mitochondrial dysfunction during myocardial ischemia. PLoS One 2020; 15:e0233591. [PMID: 32453773 PMCID: PMC7250417 DOI: 10.1371/journal.pone.0233591] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 05/10/2020] [Indexed: 01/02/2023] Open
Abstract
The heart is critically dependent on mitochondrial respiration for energy supply. Ischemia decreases oxygen availability, with catastrophic consequences for cellular energy systems. After a few minutes of ischemia, the mitochondrial respiratory chain halts, ATP levels drop and ion gradients across cell membranes collapse. Activation of cellular proteases and generation of reactive oxygen species by mitochondria during ischemia alter mitochondrial membrane permeability, causing mitochondrial swelling and fragmentation and eventually cell death. The mitochondria, therefore, are important targets of cardioprotection against ischemic injury. We have previously shown that ixazomib (IXA), a proteasome inhibitor used for treating multiple myeloma, effectively reduced the size of the infarct produced by global ischemia in isolated rat hearts and prevented degradation of the sarcoplasmic reticulum calcium release channel RyR2. The aim of this work was to further characterize the protective effect of IXA by determining its effect on mitochondrial morphology and function after ischemia. We also quantified the effect of IXA on levels of mitofusin-2, a protein involved in maintaining mitochondrial morphology and mitochondria-SR communication. We found that mitochondria were significantly preserved and functional parameters such as oxygen consumption, the ability to generate a membrane potential, and glutathione content were improved in mitochondria isolated from hearts perfused with IXA prior to ischemia. IXA also blocked the release of cytochrome c observed in ischemia and significantly preserved mitofusin-2 integrity. These beneficial effects resulted in a significant decrease in the left ventricular end diastolic pressure upon reperfusion and a smaller infarct in isolated hearts.
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Affiliation(s)
- Gina Sánchez
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Centro de Estudios en Ejercicio, Metabolismo y Cáncer, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- * E-mail: (GS); (PD)
| | - Stefanie Chalmers
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Xavier Ahumada
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Luis Montecinos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ivonne Olmedo
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Veronica Eisner
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ana Riveros
- Departamento de Química Farmacológica y Toxicológica, Facultad Ciencias Químicas y Farmacéuticas Universidad de Chile, Santiago, Chile
| | - Marcelo J. Kogan
- Departamento de Química Farmacológica y Toxicológica, Facultad Ciencias Químicas y Farmacéuticas Universidad de Chile, Santiago, Chile
| | - Sergio Lavandero
- Centro de Estudios en Ejercicio, Metabolismo y Cáncer, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Departamento de Bioquímica y Biología Molecular, Facultad Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Santiago, Chile
| | - Zully Pedrozo
- Centro de Estudios en Ejercicio, Metabolismo y Cáncer, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Santiago, Chile
| | - Paulina Donoso
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- * E-mail: (GS); (PD)
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3
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More J, Galusso N, Veloso P, Montecinos L, Finkelstein JP, Sanchez G, Bull R, Valdés JL, Hidalgo C, Paula-Lima A. N-Acetylcysteine Prevents the Spatial Memory Deficits and the Redox-Dependent RyR2 Decrease Displayed by an Alzheimer's Disease Rat Model. Front Aging Neurosci 2018; 10:399. [PMID: 30574085 PMCID: PMC6291746 DOI: 10.3389/fnagi.2018.00399] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 11/19/2018] [Indexed: 12/28/2022] Open
Abstract
We have previously reported that primary hippocampal neurons exposed to synaptotoxic amyloid beta oligomers (AβOs), which are likely causative agents of Alzheimer’s disease (AD), exhibit abnormal Ca2+ signals, mitochondrial dysfunction and defective structural plasticity. Additionally, AβOs-exposed neurons exhibit a decrease in the protein content of type-2 ryanodine receptor (RyR2) Ca2+ channels, which exert critical roles in hippocampal synaptic plasticity and spatial memory processes. The antioxidant N-acetylcysteine (NAC) prevents these deleterious effects of AβOs in vitro. The main contribution of the present work is to show that AβOs injections directly into the hippocampus, by engaging oxidation-mediated reversible pathways significantly decreased RyR2 protein content but increased single RyR2 channel activation by Ca2+ and caused considerable spatial memory deficits. AβOs injections into the CA3 hippocampal region impaired rat performance in the Oasis maze spatial memory task, decreased hippocampal glutathione levels and overall content of plasticity-related proteins (c-Fos, Arc, and RyR2) and increased ERK1/2 phosphorylation. In contrast, in hippocampus-derived mitochondria-associated membranes (MAM) AβOs injections increased RyR2 levels. Rats fed with NAC for 3-weeks prior to AβOs injections displayed comparable redox potential, RyR2 and Arc protein contents, similar ERK1/2 phosphorylation and RyR2 single channel activation by Ca2+ as saline-injected (control) rats. NAC-fed rats subsequently injected with AβOs displayed the same behavior in the spatial memory task as control rats. Based on the present in vivo results, we propose that redox-sensitive neuronal RyR2 channels partake in the mechanism underlying AβOs-induced memory disruption in rodents.
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Affiliation(s)
- Jamileth More
- Faculty of Medicine, Biomedical Neuroscience Institute, Universidad de Chile, Santiago, Chile
| | - Nadia Galusso
- Department of Neurochemistry, Stockholm University, Stockholm, Sweden
| | - Pablo Veloso
- Faculty of Dentistry, Institute for Research in Dental Sciences, Universidad de Chile, Santiago, Chile
| | - Luis Montecinos
- CEMC, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | | | - Gina Sanchez
- CEMC, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Pathophysiology Program, Faculty of Medicine, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Ricardo Bull
- Physiology and Biophysics Program, Faculty of Medicine, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - José Luis Valdés
- Faculty of Medicine, Biomedical Neuroscience Institute, Universidad de Chile, Santiago, Chile.,Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Cecilia Hidalgo
- Faculty of Medicine, Biomedical Neuroscience Institute, Universidad de Chile, Santiago, Chile.,CEMC, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Physiology and Biophysics Program, Faculty of Medicine, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Andrea Paula-Lima
- Faculty of Medicine, Biomedical Neuroscience Institute, Universidad de Chile, Santiago, Chile.,Faculty of Dentistry, Institute for Research in Dental Sciences, Universidad de Chile, Santiago, Chile
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Sánchez G, Araneda F, Peña JP, Finkelstein JP, Riquelme JA, Montecinos L, Barrientos G, Llanos P, Pedrozo Z, Said M, Bull R, Donoso P. High-Fat-Diet-Induced Obesity Produces Spontaneous Ventricular Arrhythmias and Increases the Activity of Ryanodine Receptors in Mice. Int J Mol Sci 2018; 19:ijms19020533. [PMID: 29439404 PMCID: PMC5855755 DOI: 10.3390/ijms19020533] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 01/26/2018] [Accepted: 02/07/2018] [Indexed: 12/27/2022] Open
Abstract
Ventricular arrhythmias are a common cause of sudden cardiac death, and their occurrence is higher in obese subjects. Abnormal gating of ryanodine receptors (RyR2), the calcium release channels of the sarcoplasmic reticulum, can produce ventricular arrhythmias. Since obesity promotes oxidative stress and RyR2 are redox-sensitive channels, we investigated whether the RyR2 activity was altered in obese mice. Mice fed a high fat diet (HFD) became obese after eight weeks and exhibited a significant increase in the occurrence of ventricular arrhythmias. Single RyR2 channels isolated from the hearts of obese mice were more active in planar bilayers than those isolated from the hearts of the control mice. At the molecular level, RyR2 channels from HFD-fed mice had substantially fewer free thiol residues, suggesting that redox modifications were responsible for the higher activity. Apocynin, provided in the drinking water, completely prevented the appearance of ventricular arrhythmias in HFD-fed mice, and normalized the activity and content of the free thiol residues of the protein. HFD increased the expression of NOX4, an isoform of NADPH oxidase, in the heart. Our results suggest that HFD increases the activity of RyR2 channels via a redox-dependent mechanism, favoring the appearance of ventricular arrhythmias.
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Affiliation(s)
- Gina Sánchez
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
| | - Felipe Araneda
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
| | - Juan Pedro Peña
- Escuela de Ciencias Veterinarias, Universidad de Viña del Mar, 2572007 Viña del Mar, Valparaíso, Chile.
| | - José Pablo Finkelstein
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
| | - Jaime A Riquelme
- Advanced Center for Chronic Diseases, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, 8380494 Santiago, Chile.
| | - Luis Montecinos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
| | - Genaro Barrientos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
| | - Paola Llanos
- Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, 8380492 Santiago, Chile.
| | - Zully Pedrozo
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
- Advanced Center for Chronic Diseases, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, 8380494 Santiago, Chile.
| | - Matilde Said
- Centro de Investigaciones Cardiovasculares, CCT-CONICET La Plata, Facultad de Medicina, Universidad Nacional de La Plata, 1900 La Plata, Argentina.
| | - Ricardo Bull
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
| | - Paulina Donoso
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile.
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5
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Sanchez G, Berrios D, Olmedo I, Pezoa J, Riquelme JA, Montecinos L, Pedrozo Z, Donoso P. Activation of Chymotrypsin-Like Activity of the Proteasome during Ischemia Induces Myocardial Dysfunction and Death. PLoS One 2016; 11:e0161068. [PMID: 27529620 PMCID: PMC4986934 DOI: 10.1371/journal.pone.0161068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 07/29/2016] [Indexed: 01/02/2023] Open
Abstract
Inhibitors of the ubiquitin-proteasome system improve hemodynamic parameters and decrease the infarct size after ischemia reperfusion. The molecular basis of this protection is not fully understood since most available data report inhibition of the 26 proteasome after ischemia reperfusion. The decrease in cellular ATP levels during ischemia leads to the dissociation of the 26S proteasome into the 19S regulatory complex and the 20S catalytic core, which results in protein degradation independently of ubiquitination. There is scarce information on the activity of the 20S proteasome during cardiac ischemia. Accordingly, the aim of this work was to determine the effects of 30 minutes of ischemia, or 30 min of ischemia followed by 60 minutes of reperfusion on the three main peptidase activities of the 20S proteasome in Langendorff perfused rat hearts. We found that 30 min of ischemia produced a significant increase in the chymotrypsin-like activity of the proteasome, without changes in its caspase-like or trypsin-like activities. In contrast, all three activities were decreased upon reperfusion. Ixazomib, perfused before ischemia at a concentration that reduced the chymotrypsin-like activity to 50% of the control values, without affecting the other proteasomal activities, improved the hemodynamic parameters upon reperfusion and decreased the infarct size. Ixazomib also prevented the 50% reduction in RyR2 content observed after ischemia. The protection was lost, however, when simultaneous inhibition of chymotrypsin-like and caspase-like activities of the proteasome was achieved at higher concentration of ixazomib. Our results suggest that selective inhibition of chymotrypsin-like activity of the proteasome during ischemia preserves key proteins for cardiomyocyte function and exerts a positive impact on cardiac performance after reperfusion.
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Affiliation(s)
- Gina Sanchez
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Centro de Estudios Moleculares de la Célula, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Daniela Berrios
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ivonne Olmedo
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Javier Pezoa
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Jaime A Riquelme
- Advanced Center for Chronic Diseases, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Luis Montecinos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Zully Pedrozo
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Paulina Donoso
- Centro de Estudios Moleculares de la Célula, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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6
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Ferrer P, Tello M, Montecinos L, Tordecilla R, Rodríguez C, Beltrán C, Guzmán MA, Ferrés M, Pérez CM, Afani A. Prevalence of R5 and X4 HIV variants in antiretroviral treatment experienced patients with virologic failure. J Clin Virol 2014; 60:290-4. [PMID: 24793966 DOI: 10.1016/j.jcv.2014.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 04/01/2014] [Accepted: 04/06/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND Antiretroviral therapy (ART) inhibits virus replication. Nevertheless, ART has the disadvantage of generate selective resistance and adverse events. Coreceptor antagonists are a family of antiretroviral drugs that are used with the prior knowledge of patients HIV tropism. OBJECTIVES The purpose of this work was to estimate the prevalence of R5 and X4 variants among Chilean patients under antiretroviral therapy and virological failure and investigate variables such as plasma viral load (pVL) and CD4 cell count in the population studied. STUDY DESIGN HIV RNA or proviral DNA was extracted from 454 consecutives patients and tropism testing was performed using a genotypic method performed with Geno2pheno setting a cutoff value for FPR 5.75%. RESULTS Among 454 individuals analyzed, 299 (66%) harbouring exclusively R5 variants. They not displayed a better clinical profile than individuals harbouring X4 strains (22%). For R5 patients the median of pVL and CD4 cell count were 268,000copies/mL, and 223cells/μL respectively. For X4 samples the values were 368,000copies/mL and 214cells/μL [P>0.05]). Only, 53 patients (12%) could not be analyzed and were categorized as non-reportable. CONCLUSIONS The genotypic method confirmed that R5 strains were more prevalent despite the fact that patients were treatment-experienced for several years. The genotypic strategy proved to be a faster and cost-effective option as compared to phenotypic assays. According to our results, two of every three patients under antiretroviral therapy and with virologic failure harbour R5 strains, and may be candidates for use of a CCR5 antagonist.
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Affiliation(s)
- P Ferrer
- Laboratorio de Medicina Molecular, Hospital Clínico Universidad de Chile, Santiago, Chile.
| | - M Tello
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
| | - L Montecinos
- Laboratorio de Infectología y Virología Molecular, División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile.
| | - R Tordecilla
- Laboratorio de Medicina Molecular, Hospital Clínico Universidad de Chile, Santiago, Chile.
| | - C Rodríguez
- Laboratorio de Medicina Molecular, Hospital Clínico Universidad de Chile, Santiago, Chile.
| | - C Beltrán
- Departamento de Infectología, Complejo Asistencial Barros Luco. Facultad de Medicina, Universidad de Santiago de Chile, and Chilean AIDS Cohort (ChiAC), Santiago, Chile.
| | - M A Guzmán
- Laboratorio de Medicina Molecular, Hospital Clínico Universidad de Chile, Santiago, Chile.
| | - M Ferrés
- Laboratorio de Infectología y Virología Molecular, División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile.
| | - C M Pérez
- Laboratorio de Infectología y Virología Molecular, División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile.
| | - A Afani
- Laboratorio de Medicina Molecular, Hospital Clínico Universidad de Chile, Santiago, Chile.
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Donoso P, Finkelstein JP, Montecinos L, Said M, Sánchez G, Vittone L, Bull R. Stimulation of NOX2 in isolated hearts reversibly sensitizes RyR2 channels to activation by cytoplasmic calcium. J Mol Cell Cardiol 2014; 68:38-46. [PMID: 24417961 DOI: 10.1016/j.yjmcc.2013.12.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 11/25/2013] [Accepted: 12/31/2013] [Indexed: 01/25/2023]
Abstract
The response of ryanodine receptor (RyR) channels to cytoplasmic free calcium concentration ([Ca(2+)]) is redox sensitive. Here, we report the effects of a mild oxidative stress on cardiac RyR (RyR2) channels in Langendorff perfused rat hearts. Single RyR2 channels from control ventricles displayed the same three responses to Ca(2+) reported in other mammalian tissues, characterized by low, moderate, or high maximal activation. A single episode of 5 min of global ischemia, followed by 1 min of reperfusion, enhanced 2.3-fold the activity of NOX2 compared to controls and changed the frequency distribution of the different responses of RyR2 channels to calcium, favoring the more active ones: high activity response increased and low activity response decreased with respect to controls. This change was fully prevented by perfusion with apocynin or VAS 2870 before ischemia and totally reversed by the extension of the reperfusion period to 15 min. In vitro activation of NOX2 in control SR vesicles mimicked the effect of the ischemia/reperfusion episode on the frequencies of emergence of single RyR2 channel responses to [Ca(2+)] and increased 2.2-fold the rate of calcium release in Ca(2+)-loaded SR vesicles. In vitro changes were reversed at the single channel level by DTT and in isolated SR vesicles by glutaredoxin. Our results indicate that in whole hearts a mild oxidative stress enhances the response of cardiac RyR2 channels to calcium via NOX2 activation, probably by S-glutathionylation of RyR2 protein. This change is transitory and fully reversible, suggesting a possible role of redox modification in the physiological response of cardiac RyR2 to cellular calcium influx.
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Affiliation(s)
- Paulina Donoso
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Chile
| | - José Pablo Finkelstein
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Chile
| | - Luis Montecinos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Chile
| | - Matilde Said
- Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, Argentina
| | - Gina Sánchez
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Chile
| | - Leticia Vittone
- Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, Argentina
| | - Ricardo Bull
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Chile.
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8
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Sánchez G, Fernández C, Montecinos L, Domenech RJ, Donoso P. Preconditioning tachycardia decreases the activity of the mitochondrial permeability transition pore in the dog heart. Biochem Biophys Res Commun 2011; 410:916-21. [PMID: 21708132 DOI: 10.1016/j.bbrc.2011.06.095] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Accepted: 06/11/2011] [Indexed: 10/18/2022]
Abstract
Cardioprotection by preconditioning is a central issue of current research on heart function. Several reports indicate that preventing the assembly and opening of the mitochondrial permeability transition pore (mPTP) protects the heart against ischemia-reperfusion injury. We have previously reported that brief episodes of tachycardia decrease the infarct size produced by subsequent prolonged occlusion of a coronary artery, indicating that controlled tachycardia is an effective preconditioning manoeuvre. The effects of preconditioning tachycardia on mPTP activity have not been reported. Therefore, in this work we investigated if preconditioning tachycardia protects against calcium-induced mitochondrial swelling, a measure of mPTP activity. We found that tachycardia decreased by 2.5-fold the rate of mitochondrial calcium-induced swelling, a factor that presumably contributes to the cardioprotective effects of tachycardia. The oxidative status of the cell increased after tachycardia, as evidenced by the decrease in the cellular and mitochondrial GSH/GSSG ratio. We also observed increased S-glutathionylation of cyclophilin-D, an essential mPTP component, after tachycardia. This reversible redox modification of cyclophilin-D may account, al least in part, for the decreased mPTP activity produced by preconditioning tachycardia.
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Affiliation(s)
- Gina Sánchez
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Independencia 1027, Santiago 8389100, Chile.
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Rodríguez JP, Montecinos L, Ríos S, Reyes P, Martínez J. Mesenchymal stem cells from osteoporotic patients produce a type I collagen-deficient extracellular matrix favoring adipogenic differentiation. J Cell Biochem 2000; 79:557-65. [PMID: 10996846 DOI: 10.1002/1097-4644(20001215)79:4<557::aid-jcb40>3.0.co;2-h] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Mesenchymal stem cells (MSCs), precursor cells resident in the bone marrow, have the capacity to differentiate into bone, cartilage, fat, and connective tissue. We have recently reported that MSCs from "healthy" donors differ from cells obtained from osteoporotic postmenopausal women in their proliferation rate, mitogenic response to osteogenic growth factors, and potential to mineralize. The purpose of this study was to examine the factors that explain the differential capacity of MSCs derived from "healthy" control and osteoporotic postmenopausal women to support mineralization. In addition, we examined the factors that regulate the differentiation of osteoporotic cells into adipocytes. For this purpose, we isolated MSCs from bone marrow of donors and analyzed the synthesis and deposition of type I collagen, the main component of bone extracellular matrix, the time course of gelatinolytic activity expression, the deposition of transforming growth factor beta (TGF-beta), and the ability of cells to differentiate into adipocytes. Our results indicate that cells derived from osteoporotic donors synthesized 50% less type I collagen than normal cells and maintained higher levels of gelatinolytic activity under differentiation conditions (70% versus 15% after 14 days in culture). MSCs derived from osteoporotic women produced 60-65% less TGF-beta and expressed higher adipogenic capacity. We conclude that the capacity of MSCs derived from osteoporotic postmenopausal women to generate and maintain type I collagen-rich extracellular matrix is decreased, favoring their adipogenic differentiation. These observations may explain the decreased mineralization previously observed in these types of cells.
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Affiliation(s)
- J P Rodríguez
- Laboratorio de Biología Celular, INTA, Universidad de Chile, Santiago, Chile.
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Villegas J, Zárraga AM, Muller I, Montecinos L, Werner E, Brito M, Meneses AM, Burzio LO. A novel chimeric mitochondrial RNA localized in the nucleus of mouse sperm. DNA Cell Biol 2000; 19:579-88. [PMID: 11034550 DOI: 10.1089/104454900439809] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Six identical cDNA clones corresponding to an RNA of 1685 nucleotides that is enriched in mouse sperm compared with testis were isolated from a mouse testis cDNA library. The sequence of these clones corresponds to the 16S mitochondrial RNA plus an inverted repeat of 120 bp covalently joined to the 5' end of the RNA. By RT-PCR, it was demonstrated that this transcript, referred to as chimeric RNA, was present in mouse sperm, testis, liver, kidney, brain, and spleen. The absence of an equivalent sequence in mitochondrial DNA or as a mitochondrial pseudogene in total DNA extracted from sperm, testis, and somatic tissues suggests that the chimeric RNA is a post-transcriptional product, maybe resulting from a trans splicing reaction. The chimeric RNA was found by RT-PCR in total RNA extracted from purified sperm heads. This result was confirmed by in situ hybridization, which showed clear staining of the sperm nucleus with probes corresponding to sequences of the mitochondrial 16S RNA and the inverted repeat.
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Affiliation(s)
- J Villegas
- Bios Chile Ingeniería Genética S.A., Institute for Fundamental and Applied Biology and Fundación Ciencia Para La Vida, Nuñoa, Santiago, Chile
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Montecinos L, Ramírez B, Lisboa C, Borzone G. [Peroxide metabolism on respiratory muscles: effect of growth, maturation and aging]. Rev Med Chil 1999; 127:269-75. [PMID: 10436710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Glutathione peroxidase (GSHPx) and catalase are two important cellular antioxidant enzymes involved in H2O2 and lipid-peroxide metabolism. AIM To study the effects of growth, maturation and aging on the activity of these enzymes. MATERIAL AND METHODS GSHPx and catalase specific activities were measured in samples of diaphragm and intercostal muscle of male Sprague-Dawley rats of different ages (21, 50, 70, 180 and 365 days), anesthetised with chloral hydrate (45 mg/100 g i.p.). RESULTS The diaphragm and intercostal muscles did not differ in GSHPx activity at 21 days. After that, GSHPx activity increased progressively with age, but following a different pattern, in each muscle, suggesting an increase in enzyme substrates with age. In one year old animals, GSHPx activity was 5 times higher for the diaphragm and 3 times higher for the intercostal muscles, when compared with values observed at 21 days of age. Catalase activity also increased with age in the diaphragm but not in the intercostal muscles. CONCLUSIONS GSHPx activity increases progressively with age in rat respiratory muscles, with a time course that is specific of each muscle. Catalase activity increases with age only in the diaphragm. These results support the hypothesis that antioxidants in respiratory muscles undergo specific regulatory changes with age.
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Affiliation(s)
- L Montecinos
- Departamento Enfermedades Respiratorias, Pontificia Universidad Católica de Chile, Santiago, Chile
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Bazaes S, Montecinos L, Krautwurst H, Goldie H, Cardemil E, Jabalquinto AM. Identification of reactive conserved histidines in phosphoenolpyruvate carboxykinases from Escherichia coli and Saccharomyces cerevisiae. Biochim Biophys Acta 1997; 1337:166-74. [PMID: 9048893 DOI: 10.1016/s0167-4838(96)00155-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Escherichia coli and Saccharomyces cerevisiae phospho enol pyruvate (PEP) carboxykinases are inactivated by diethylpyrocarbonate (DEP). Inactivation follows pseudo-first-order kinetics and exhibits a second order rate constant of 0.8 M-1 s-1 for the bacterial enzyme and of 3.3 M-1 s-1 for the yeast carboxykinase. A mixture of ADP + PEP + MnCl2 protects against inactivation by DEP, suggesting that residues within the active site are being modified. After digestion of the modified proteins with trypsin, the labeled peptides were isolated by reverse-phase high-performance liquid chromatography and sequenced by Edman degradation. His-271 of E. coli carboxykinase and His-273 of the yeast enzyme were identified as the reactive amino-acid residues. The modified histidine residues occupy equivalent positions in these enzymes, and they are located in a highly conserved region of all ATP-dependent phospho enol pyruvate carboxykinases described so far.
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Affiliation(s)
- S Bazaes
- Departamento de Química, Universidad Metropolitana de Ciencias de la Educación, Santiago, Chile
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Montecinos L, Bravo L, Tedias M, Jara R, Peralta MI, Alvarez R, Ríos C, Miranda S, Alvarez MI, Zanghellini G. [Rehabilitation of chronic mental patients. A combination of function delegation scheme with operative conditioning technics]. Acta Psiquiatr Psicol Am Lat 1978; 24:35-40. [PMID: 685702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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