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1.
Hum Mol Genet ; 28(10): 1645-1660, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30629163

RESUMO

Mutations of LRRK2, encoding leucine-rich repeat kinase 2 (LRRK2), are the leading cause of autosomal dominant Parkinson's disease (PD). The most frequent of these mutations, G2019S substitution, increases kinase activity, but it remains unclear how it causes PD. Recent studies suggest that LRRK2 modulates mitochondrial homeostasis. Mitochondrial dysfunction plays a key role in the pathogenesis of autosomal recessive PD forms linked to PARK2 and PINK1, encoding the cytosolic E3 ubiquitin-protein ligase Parkin and the mitochondrial kinase PINK1, which jointly regulate mitophagy. We explored the role of LRRK2 and its kinase activity in PINK1/Parkin-dependent mitophagy. LRRK2 increased mitochondrial aggregation and attenuated mitochondrial clearance in cells coexpressing Parkin and exposed to the protonophore carbonylcyanide m-chlorophenylhydrazone. Förster resonance energy transfer imaging microscopy showed that LRRK2 impaired the interactions between Parkin and Drp1 and their mitochondrial targets early in mitophagy. The inhibition of LRRK2 kinase activity by a 'kinase-dead' LRRK2 mutation or with a pharmacological inhibitor (LRRK2-IN-1) restored these interactions. The monitoring of mitophagy in human primary fibroblasts with the novel dual-fluorescence mtRosella reporter and a new hypothermic shock paradigm revealed similar defects in PD patients with the G2019S LRRK2 substitution or PARK2 mutations relative to healthy subjects. This defect was restored by LRRK2-IN-1 treatment in LRRK2 patients only. Our results suggest that PD forms due to LRRK2 and PARK2 mutations involve pathogenic mechanisms converging on PINK1/Parkin-dependent mitophagy.


Assuntos
Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Doença de Parkinson/genética , Proteínas Quinases/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Benzodiazepinonas/farmacologia , Carbonil Cianeto m-Clorofenil Hidrazona/análogos & derivados , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Transferência Ressonante de Energia de Fluorescência , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/antagonistas & inibidores , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , Mitocôndrias/patologia , Mitofagia/efeitos dos fármacos , Mutação , Doença de Parkinson/patologia , Fosforilação , Cultura Primária de Células , Pirimidinas/farmacologia
2.
Am J Hum Genet ; 98(3): 500-513, 2016 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-26942284

RESUMO

Autosomal-recessive early-onset parkinsonism is clinically and genetically heterogeneous. The genetic causes of approximately 50% of autosomal-recessive early-onset forms of Parkinson disease (PD) remain to be elucidated. Homozygozity mapping and exome sequencing in 62 isolated individuals with early-onset parkinsonism and confirmed consanguinity followed by data mining in the exomes of 1,348 PD-affected individuals identified, in three isolated subjects, homozygous or compound heterozygous truncating mutations in vacuolar protein sorting 13C (VPS13C). VPS13C mutations are associated with a distinct form of early-onset parkinsonism characterized by rapid and severe disease progression and early cognitive decline; the pathological features were striking and reminiscent of diffuse Lewy body disease. In cell models, VPS13C partly localized to the outer membrane of mitochondria. Silencing of VPS13C was associated with lower mitochondrial membrane potential, mitochondrial fragmentation, increased respiration rates, exacerbated PINK1/Parkin-dependent mitophagy, and transcriptional upregulation of PARK2 in response to mitochondrial damage. This work suggests that loss of function of VPS13C is a cause of autosomal-recessive early-onset parkinsonism with a distinctive phenotype of rapid and severe progression.


Assuntos
Mitofagia/genética , Transtornos Parkinsonianos/genética , Proteínas Quinases/genética , Proteínas/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Animais , Células COS , Estudos de Casos e Controles , Consanguinidade , Feminino , Inativação Gênica , Heterogeneidade Genética , Células HEK293 , Heterozigoto , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Parkinsonianos/diagnóstico , Linhagem , Fenótipo , Proteínas Quinases/metabolismo , Proteínas/metabolismo , Reprodutibilidade dos Testes , Turquia , Ubiquitina-Proteína Ligases/metabolismo
3.
Glia ; 66(8): 1736-1751, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29665074

RESUMO

Neuroinflammation and mitochondrial dysfunction, key mechanisms in the pathogenesis of Parkinson's disease (PD), are usually explored independently. Loss-of-function mutations of PARK2 and PARK6, encoding the E3 ubiquitin protein ligase Parkin and the mitochondrial serine/threonine kinase PINK1, account for a large proportion of cases of autosomal recessive early-onset PD. PINK1 and Parkin regulate mitochondrial quality control and have been linked to the modulation of innate immunity pathways. We report here an exacerbation of NLRP3 inflammasome activation by specific inducers in microglia and bone marrow-derived macrophages from Park2-/- and Pink1-/- mice. The caspase 1-dependent release of IL-1ß and IL-18 was, therefore, enhanced in Park2-/- and Pink1-/- cells. This defect was confirmed in blood-derived macrophages from patients with PARK2 mutations and was reversed by MCC950, which specifically inhibits NLRP3 inflammasome complex formation. Enhanced NLRP3 signaling in Parkin-deficient cells was accompanied by a lack of induction of A20, a well-known negative regulator of the NF-κB pathway recently shown to attenuate NLRP3 inflammasome activity. We also found an inverse correlation between A20 abundance and IL-1ß release, in human macrophages challenged with NLRP3 inflammasome inducers. Overall, our observations suggest that the A20/NLRP3-inflammasome axis participates in the pathogenesis of PARK2-linked PD, paving the way for the exploration of its potential as a biomarker and treatment target.


Assuntos
Retroalimentação Fisiológica/fisiologia , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Ubiquitina-Proteína Ligases/deficiência , Adulto , Humanos , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Microglia/metabolismo , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , NF-kappa B/metabolismo
4.
Clin Sci (Lond) ; 121(9): 405-13, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21605084

RESUMO

We tested whether inhibition of mitochondrial membrane potential dissipation by CsA (ciclosporin A) would prevent doxorubicin-induced myocardial and mitochondrial dysfunction. Acute and subchronic models of doxorubicin exposition were performed in mice with either a single intraperitoneal bolus (10 mg/kg of body weight, intraperitoneal) or one injection of 4 mg·kg(-1) of body weight·week(-1) during 5 weeks. Follow-up was at 1.5 weeks and 16 weeks in acute and subchronic models respectively. Mice received either CsA (1 mg/kg of body weight, intraperitoneal on alternate days) or saline until follow-up. Heart function was evaluated by echocardiography. Mitochondrial measurements included oxygen consumption, membrane potential and externally added calcium-induced mitochondrial permeability transition. Mitochondrial mass was evaluated by transmission electronic microscopy and mtDNA (mitochondrial DNA) content. Mitochondrial dynamics were detected as the expression of GTPases involved in mitochondrial fusion and fission. In both the acute and chronic models, doxorubicin decreased left ventricular fractional shortening and survival. Heart function and survival were improved by CsA, but not by tacrolimus (FK506), a ciclosporin derivative with no inhibitory effect on the mitochondrial transition pore. In the acute model, doxorubicin exposure was associated with increased mtDNA content, mitochondrial fragmentation and changes in mitochondrial fusion- and fission-related transcripts [increases in Mfn2 (mitofusin 2), Opa1 (optic atrophy 1 homologue) and Fis1 (fission 1 homologue), and no changes in Drp1 (dynamin 1-like)]. CsA did not alter mitochondrial biogenesis, but prevented mitochondrial fragmentation and partially restored the mitochondrial energy-producing capacity. These findings suggest that in vivo CsA treatment may limit MPTP (mitochondrial permeability transition pore) opening, mitochondrial potential loss and contractile depression in acute and chronic models of cardiac toxicity induced by doxorubicin.


Assuntos
Ciclosporina/farmacologia , Doxorrubicina/efeitos adversos , Cardiopatias/induzido quimicamente , Cardiopatias/patologia , Mitocôndrias Cardíacas/metabolismo , Miocárdio/patologia , Animais , Antibióticos Antineoplásicos/farmacologia , Primers do DNA/genética , DNA Mitocondrial/metabolismo , Imunossupressores/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Cardíacas/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , Permeabilidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Apoptosis ; 15(7): 769-81, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20151196

RESUMO

Lamellarin D (Lam D), a marine alkaloid, exhibits a potent cytotoxicity against many different tumors. The pro-apoptotic function of Lam D has been attributed to its direct induction of mitochondrial permeability transition (MPT). This study was undertaken to explore the mechanisms through which Lam D promotes changes in mitochondrial function and as a result apoptosis. The use of eight Lam derivatives provides useful structure-apoptosis relationships. We demonstrate that Lam D and structural analogues induce apoptosis of cancer cells by acting directly on mitochondria inducing reduction of mitochondrial membrane potential, swelling and cytochrome c release. Cyclosporin A, a well-known inhibitor of MPT, completely prevents mitochondrial signs of apoptosis. The drug decreases calcium uptake by mitochondria but not by microsomes indicating that Lam D-dependent permeability is specific to mitochondrial membranes. In addition, upon Lam D exposure, a rapid decline of mitochondrial respiration and ATP synthesis occurs in isolated mitochondria as well as in intact cells. Evaluation of the site of action of Lam D on the electron-transport chain revealed that the activity of respiratory chain complex III is reduced by a half. To determine whether Lam D could induce MPT-dependent apoptosis by inhibiting mitochondrial respiration, we generated respiration-deficient cells (rho0) derived from human melanoma cells. In comparison to parental cells, rho0 cells are totally resistant to the induction of MPT-dependent apoptosis by Lam D. Our results indicate that functional mitochondria are required for Lam D-induced apoptosis. Inhibition of mitochondrial respiration is responsible for MPT-dependent apoptosis of cancer cells induced by Lam-D.


Assuntos
Antineoplásicos/toxicidade , Apoptose , Cumarínicos/toxicidade , Compostos Heterocíclicos de 4 ou mais Anéis/toxicidade , Isoquinolinas/toxicidade , Mitocôndrias/efeitos dos fármacos , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Cumarínicos/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Humanos , Isoquinolinas/química , Células Jurkat , Camundongos , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , Consumo de Oxigênio/efeitos dos fármacos , Ratos
6.
Crit Care Med ; 38(10): 2031-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20657270

RESUMO

OBJECTIVE: Several studies report calcium mishandling, sarcomere disarray, and caspase activation during heart failure. Although active caspases have been shown to cleave myofibrillar proteins, little is known regarding their effects on calcium handling proteins. Therefore, we aimed to explore how endotoxin-induced caspase activation disrupts intracellular calcium regulation. DESIGN: Randomized controlled trial. SETTING: Small animal research laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: Sepsis was induced by injection of endotoxin (10 mg/kg, intravenously). Caspase inhibition was achieved by coinjection with zVAD.fmk (3 mg/kg, intravenously). We first isolated adult rat ventricular myocytes from control, endotoxin, and (endotoxin + zVAD)-treated rats to characterize contractile parameters and cellular calcium homeostasis. Underlying molecular mechanisms responsible for calcium mishandling were explored on sarcoplasmic reticulum vesicles and mitochondria prepared from treated animals. All experiments were performed 4 hrs postendotoxin treatment. MEASUREMENTS AND MAIN RESULTS: zVAD normalized reductions in fractional cell shortening and relaxation rate triggered by endotoxin treatment. Both sarco-/endoplasmic reticulum Ca-ATPase and mitochondria-dependent calcium uptakes were impaired after endotoxin treatment and prevented when myocytes were isolated from zVAD-treated endotoxinic rat hearts. zVAD blocked endotoxin-induced phospholamban dephosphorylation, protein phosphatase 2A activation, and mitochondrial calcium retention capacity reduction. To strengthen these results, control sarcoplasmic reticulum vesicles and mitochondria were incubated with active recombinant caspase-3. Although no effects were observed on mitochondria, caspase-3 directly exerts detrimental effects on sarcoplasmic reticulum calcium uptake capacity by activating protein phosphatase 2A, leading to phospholamban dephosphorylation. CONCLUSIONS: Caspase inhibition protects from endotoxin-induced sarcoplasmic reticulum calcium uptake capacity reduction and mitochondrial dysfunction.


Assuntos
Caspases/metabolismo , Endotoxinas/farmacologia , Miócitos Cardíacos/fisiologia , Proteína Fosfatase 2/metabolismo , Animais , Western Blotting , Cálcio/análise , Cálcio/metabolismo , Cálcio/fisiologia , Caspases/fisiologia , Ativação Enzimática/fisiologia , Insuficiência Cardíaca/enzimologia , Insuficiência Cardíaca/fisiopatologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/fisiologia , Mitocôndrias Cardíacas/química , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/fisiologia , Contração Miocárdica/efeitos dos fármacos , Contração Miocárdica/fisiologia , Miócitos Cardíacos/química , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/enzimologia , Proteína Fosfatase 2/fisiologia , Ratos , Ratos Sprague-Dawley
7.
J Pharmacol Exp Ther ; 329(2): 641-8, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19190234

RESUMO

Use of metal carbonyl-based compounds capable of releasing carbon monoxide (CO) in biological systems have emerged as a potential adjunctive therapy for sepsis via their antioxidant, anti-inflammatory, and antiapoptotic effects. The role of CO in regulation of mitochondrial dysfunction and biogenesis associated with sepsis has not been investigated. In the present study, we employed a ruthenium-based water-soluble CO carrier, tricarbonylchoro(glycinato)ruthenium (II) (CORM-3), one of the novel CO-releasing molecules (CO-RMs), to test whether CO can improve cardiac mitochondrial dysfunction and survival in peritonitis-induced sepsis. Peritonitis was performed in mice by cecal ligation and perforation. Tumor necrosis factor-alpha, interleukin-10, and nitrite/nitrate plasma levels were tested to evaluate the systemic inflammatory response. Functional mitochondrial studies included determination of membrane potential, respiration, and redox status. Oxidative stress was evaluated by measurements of mitochondrial hydrogen peroxide, carbonyl protein and GSH levels. Mitochondrial biogenesis was assessed by peroxisome proliferator-activated receptor gamma coactivator (PGC)-1alpha protein expression and mitochondrial DNA (mtDNA) copy number. The systemic inflammatory response elicited by peritonitis was accompanied by mitochondrial energetic metabolism deterioration and reduced PGC-1alpha protein expression. CORM-3 treatment in septic mice restored the deleterious effects of sepsis on mitochondrial membrane potential, respiratory control ratio, and energetics. It is interesting that administration of CORM-3 during sepsis elicited a mild oxidative stress response that stimulated mitochondrial biogenesis with PGC-1alpha protein expression and mtDNA copy number increases. Our results reveal that delivery of controlled amounts of CO dramatically reduced mortality in septic mice, indicating that CO-RMs could be used therapeutically to prevent organ dysfunction and death in sepsis.


Assuntos
Monóxido de Carbono/farmacologia , Metabolismo Energético/efeitos dos fármacos , Mitocôndrias Cardíacas/efeitos dos fármacos , Compostos Organometálicos/administração & dosagem , Sepse/prevenção & controle , Animais , Monóxido de Carbono/metabolismo , DNA Mitocondrial/biossíntese , Modelos Animais de Doenças , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos ICR , Mitocôndrias Cardíacas/metabolismo , NAD/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Peritonite/complicações , Sepse/etiologia , Sepse/metabolismo
8.
Open Biol ; 8(11)2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30404819

RESUMO

Mutations in PINK1 and Parkin result in autosomal recessive Parkinson's disease (PD). Cell culture and in vitro studies have elaborated the PINK1-dependent regulation of Parkin and defined how this dyad orchestrates the elimination of damaged mitochondria via mitophagy. PINK1 phosphorylates ubiquitin at serine 65 (Ser65) and Parkin at an equivalent Ser65 residue located within its N-terminal ubiquitin-like domain, resulting in activation; however, the physiological significance of Parkin Ser65 phosphorylation in vivo in mammals remains unknown. To address this, we generated a Parkin Ser65Ala (S65A) knock-in mouse model. We observe endogenous Parkin Ser65 phosphorylation and activation in mature primary neurons following mitochondrial depolarization and reveal this is disrupted in ParkinS65A/S65A neurons. Phenotypically, ParkinS65A/S65A mice exhibit selective motor dysfunction in the absence of any overt neurodegeneration or alterations in nigrostriatal mitophagy. The clinical relevance of our findings is substantiated by the discovery of homozygous PARKIN (PARK2) p.S65N mutations in two unrelated patients with PD. Moreover, biochemical and structural analysis demonstrates that the ParkinS65N/S65N mutant is pathogenic and cannot be activated by PINK1. Our findings highlight the central role of Parkin Ser65 phosphorylation in health and disease.


Assuntos
Mitocôndrias/metabolismo , Mitofagia , Doença de Parkinson/metabolismo , Proteínas Quinases/metabolismo , Ubiquitina-Proteína Ligases , Animais , Humanos , Camundongos , Camundongos Transgênicos , Mitocôndrias/genética , Mitocôndrias/patologia , Doença de Parkinson/genética , Doença de Parkinson/patologia , Fosforilação/genética , Proteínas Quinases/genética , Serina/genética , Serina/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
9.
Mitochondrion ; 6(3): 149-54, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16725383

RESUMO

Growing evidence suggest that, in the heart, sphingosine participates to contractile dysfunction by altering calcium transients and mitochondria function. However, mechanisms underlying sphingosine-induced cardiac mitochondria dysfunction are poorly understood. Here, we studied the effects of sphingosine on isolated cardiac mitochondria of either wild-type or Bcl-2 overexpressing transgenic mice. Sphingosine induced reductions in ADP-coupled respiration, membrane potential, mitochondrial cytochrome c content and ATP production, which were partially prevented by cyclosporine A and mitochondrial Bcl-2 overexpression. These data suggest that sphingosine promotes mitochondrial permeability transition pore opening, which may result in uncoupled respiration and participate in cardiac contractile dysfunction.


Assuntos
Mitocôndrias/metabolismo , Contração Miocárdica , Esfingosina/farmacologia , Animais , Cálcio/metabolismo , Ciclosporina/farmacologia , Citocromos c/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Esfingosina/metabolismo
10.
Can J Cardiol ; 29(4): 510-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23062666

RESUMO

BACKGROUND: Mechanical dyssynchrony associated with rapid pacing induces cardiac cell stress and myocardial apoptotic pathway activation that has been implicated in the pathophysiology of left ventricular (LV) dysfunction. Effects of dyssynchrony per se are not fully understood. The objective of our study was to test whether ventricular dyssynchrony would elicit myocardial alterations in LV calcium handling regulation and cell survival or apoptosis signalling in right ventricular-paced swine. METHODS: Implantation of pacemaker was performed under anaesthesia. Endocardial bipolar screw lead was inserted into the right jugular vein and positioned either in the right atrium or at the right ventricular (RV) apex. Swine were paced at 150 beats per minute for 3 weeks. RESULTS: Compared with right atrial pacing, RV pacing led to abnormal LV sarcoplasmic reticulum calcium uptake (315 ± 65 vs 155 ± 55 nmol/min/mg, P < 0.05) and LV calcium-handling protein expression, ie, 35% reduction in ryanodine receptor 2, 25% decline in sarcoplasmic reticulum Ca(2+) ATPase, 70% increase in Na(+)/Ca(2+) exchanger, and 10% increase in phospholamban. RV pacing also elicited activation of LV apoptotic cascades without nuclear apoptosis. So-called interrupted apoptosis was the result of increased expression of X-linked inhibitor of apoptosis protein. Apoptosis and calcium mishandling were documented in absence of depressed heart function (ejection fraction 62 ± 8% vs 57 ± 12%, in right atrial- and RV-paced hearts, respectively, P > 0.05). CONCLUSIONS: Slow rate RV pacing causes mechanical dyssynchrony and profound LV alterations in both apoptotic pathways and calcium handling in the early stages of pacing-induced cardiomyopathy.


Assuntos
Apoptose , Cálcio/metabolismo , Estimulação Cardíaca Artificial/efeitos adversos , Cardiomiopatias/etiologia , Frequência Cardíaca , Ventrículos do Coração , Miócitos Cardíacos/metabolismo , Animais , Western Blotting , Proteínas de Ligação ao Cálcio/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Cardiomiopatias/metabolismo , Caspases/metabolismo , Sobrevivência Celular , Ecocardiografia , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação da Expressão Gênica , Ventrículos do Coração/metabolismo , Ventrículos do Coração/fisiopatologia , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Retículo Sarcoplasmático/metabolismo , Suínos , Fator de Necrose Tumoral alfa/análise
11.
PLoS One ; 8(3): e58718, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23536817

RESUMO

AIMS: Development of metabolic syndrome is associated with impaired cardiac performance, mitochondrial dysfunction and pro-inflammatory cytokine increase, such as the macrophage migration inhibitory factor MIF. Depending on conditions, MIF may exert both beneficial and deleterious effects on the myocardium. Therefore, we tested whether pharmacological inhibition of MIF prevented or worsened metabolic syndrome-induced myocardial dysfunction. METHODS AND RESULTS: C57BL/6J mice were fed for ten weeks with 60% fat-enriched diet (HFD) or normal diet (ND). MIF inhibition was obtained by injecting mice twice a week with ISO-1, for three consecutive weeks. Then, triglycerides, cholesterol, fat mass, glucose intolerance, insulin resistance, ex vivo cardiac contractility, animal energetic substrate utilization assessed by indirect calorimetry and mitochondrial respiration and biogenesis were evaluated. HFD led to fat mass increase, dyslipidemia, glucose intolerance and insulin resistance. ISO-1 did not alter these parameters. However, MIF inhibition was responsible for HFD-induced cardiac dysfunction worsening. Mouse capacity to increase oxygen consumption in response to exercise was reduced in HFD compared to ND, and further diminished in ISO-1-treated HFD group. Mitochondrial respiration was reduced in HFD mice, treated or not with ISO-1. Compared to ND, mitochondrial biogenesis signaling was upregulated in the HFD as demonstrated by mitochondrial DNA amount and PGC-1α expression. However, this increase in biogenesis was blocked by ISO-1 treatment. CONCLUSION: MIF inhibition achieved by ISO-1 was responsible for a reduction in HFD-induced mitochondrial biogenesis signaling that could explain majored cardiac dysfunction observed in HFD mice treated with MIF inhibitor.


Assuntos
Cardiomiopatias/etiologia , Cardiomiopatias/fisiopatologia , Isoxazóis/farmacologia , Fatores Inibidores da Migração de Macrófagos/antagonistas & inibidores , Síndrome Metabólica/complicações , Síndrome Metabólica/metabolismo , Miocárdio/metabolismo , Animais , Metabolismo dos Carboidratos/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Metabolismo Energético/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fatores Inibidores da Migração de Macrófagos/genética , Fatores Inibidores da Migração de Macrófagos/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Consumo de Oxigênio/efeitos dos fármacos
12.
Vet J ; 194(2): 222-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22658821

RESUMO

The analysis of exhaled breath condensate (EBC) offers the potential for identifying lung disease markers in humans and animals, but methodological issues and standardised procedures need to be addressed before the technique can be considered for use in applications to help understand the role of environmental pollution in respiratory diseases. The purpose of this study was to develop and implement a new device using a glass-chamber for collecting EBC non-invasively from rats in order to analyse EBC markers in lipopolysaccharide (LPS)-induced acute lung injury. Eighty-four adult rats were used in five different series of experiments to determine the source of EBC formation, intra-day and inter-day variability, and the influence of environmental parameters on EBC markers. The hypothesis that inflammation induces an oxidative stress was assessed by measuring pH, nitrogen oxides (NOx) and hydrogen peroxide (H(2)O(2)) in EBC. The results confirmed that EBC fluid was generated at the level of the respiratory tract. The repeatability studies of disease markers indicated higher concentrations of NOx and H(2)O(2) at midday compared to the morning, but there were no significant difference between measurements on consecutive days. EBC volume was influenced by both ambient temperature and humidity. Moreover, 3h after LPS challenge, significantly increased concentrations of both NOx and H(2)O(2) were observed in EBC of the LPS group compared with controls (P=0.005 and P=0.027, respectively). These results suggested that EBC collection may be a valuable tool to monitor the presence of markers, such as NOx and H(2)O(2), in an animal model of LPS-induced acute lung injury.


Assuntos
Testes Respiratórios/métodos , Peróxido de Hidrogênio/análise , Lipopolissacarídeos , Pneumopatias/induzido quimicamente , Pneumopatias/metabolismo , Óxidos de Nitrogênio/análise , Animais , Testes Respiratórios/instrumentação , Líquido da Lavagem Broncoalveolar/citologia , Endotoxemia/metabolismo , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Inflamação/fisiopatologia , Masculino , Estresse Oxidativo/fisiologia , Ratos , Ratos Sprague-Dawley , Sistema Respiratório/metabolismo , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodos , Manejo de Espécimes/veterinária
13.
PLoS One ; 7(8): e41836, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22870253

RESUMO

AIMS: Metabolic syndrome induces cardiac dysfunction associated with mitochondria abnormalities. As low levels of carbon monoxide (CO) may improve myocardial and mitochondrial activities, we tested whether a CO-releasing molecule (CORM-3) reverses metabolic syndrome-induced cardiac alteration through changes in mitochondrial biogenesis, dynamics and autophagy. METHODS AND RESULTS: Mice were fed with normal diet (ND) or high-fat diet (HFD) for twelve weeks. Then, mice received two intraperitoneal injections of CORM-3 (10 mg x kg(-1)), with the second one given 16 hours after the first. Contractile function in isolated hearts and mitochondrial parameters were evaluated 24 hours after the last injection. Mitochondrial population was explored by electron microscopy. Changes in mitochondrial dynamics, biogenesis and autophagy were assessed by western-blot and RT-qPCR. Left ventricular developed pressure was reduced in HFD hearts. Mitochondria from HFD hearts presented reduced membrane potential and diminished ADP-coupled respiration. CORM-3 restored both cardiac and mitochondrial functions. Size and number of mitochondria increased in the HFD hearts but not in the CORM-3-treated HFD group. CORM-3 modulated HFD-activated mitochondrial fusion and biogenesis signalling. While autophagy was not activated in the HFD group, CORM-3 increased the autophagy marker LC3-II. Finally, ex vivo experiments demonstrated that autophagy inhibition by 3-methyladenine abolished the cardioprotective effects of CORM-3. CONCLUSION: CORM-3 may modulate pathways controlling mitochondrial quality, thus leading to improvements of mitochondrial efficiency and HFD-induced cardiac dysfunction.


Assuntos
Antimetabólitos/farmacologia , Monóxido de Carbono/farmacologia , Cardiopatias , Síndrome Metabólica , Mitocôndrias Cardíacas/metabolismo , Contração Miocárdica/efeitos dos fármacos , Compostos Organometálicos/farmacologia , Animais , Autofagia/efeitos dos fármacos , Gorduras na Dieta/efeitos adversos , Feminino , Cardiopatias/tratamento farmacológico , Cardiopatias/etiologia , Cardiopatias/metabolismo , Cardiopatias/fisiopatologia , Humanos , Síndrome Metabólica/induzido quimicamente , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Síndrome Metabólica/fisiopatologia , Camundongos , Transdução de Sinais/efeitos dos fármacos
14.
Pharmacol Rep ; 63(5): 1189-94, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22180361

RESUMO

The objective of the present study was to delineate the role of excessive accumulation of mitochondrial nitrogen species contributing to oxidative stress induced by hypoxia/reoxygenation in isolated mitochondria. The present study shows that incubation of isolated rat heart mitochondria under hypoxic, but not anoxic conditions, followed by reoxygenation decreases the rate of mitochondrial oxygen consumption, mitochondrial membrane potential, and calcium retention capacity. These alterations were prevented, at least in part, by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a nitric oxide (NO) scavenger, N(G)-nitro-L-arginine-methyl ester (L-NAME), a broad-spectrum NO synthase inhibitor, or tempol, a superoxide dismutase mimetic and catalytic scavenger of peroxynitrite-derived radicals. In conclusion, these findings suggest a crucial role for nitric oxide pathways in cardiac oxidative stress induced by hypoxia/reoxygenation.


Assuntos
Hipóxia Celular , Mitocôndrias Cardíacas/patologia , Óxido Nítrico/metabolismo , Oxigênio/metabolismo , Animais , Benzoatos/farmacologia , Óxidos N-Cíclicos/farmacologia , Imidazóis/farmacologia , Técnicas In Vitro , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias Cardíacas/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Marcadores de Spin
15.
J Am Coll Cardiol ; 48(2): 377-85, 2006 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-16843190

RESUMO

OBJECTIVES: The purpose of this study was to test whether mitochondrial dysfunction is causative of sepsis sequelae, a mouse model of peritonitis sepsis induced by cecal ligation and perforation. Inhibition of mitochondrial permeability transition was achieved by means of pharmacological drugs and overexpression of the antiapoptotic protein B-cell leukemia (Bcl)-2. BACKGROUND: Sepsis is the leading cause of death in critically ill patients and the predominant cause of multiple organ failure. Although precise mechanisms by which sepsis leads to multiple organ dysfunction are unknown, growing evidence suggests that perturbations of key mitochondrial functions, including adenosine triphosphate production, Ca2+ homeostasis, oxygen-derived free radical production, and permeability transition, might be involved in sepsis pathophysiology. METHODS: Heart and lung functions were evaluated respectively by means of isolated heart preparation, bronchoalveolar lavage fluid protein concentration, lung wet/dry weight ratio, lung homogenate myeloperoxidase activity, and histopathologic grading. Respiratory fluxes, calcium uptake, and membrane potential were evaluated in isolated heart mitochondria. RESULTS: Peritonitis sepsis induced multiple organ dysfunction, mitochondrial abnormalities, and increased mortality rate, which were reduced by pharmacological inhibition of mitochondrial transition by cyclosporine derivatives and mitochondrial Bcl-2 overexpression. CONCLUSIONS: Our study provides strong evidence that mitochondrial permeability transition plays a critical role in septic organ dysfunction. These studies demonstrate that mitochondrial dysfunction in sepsis is causative rather than epiphenomenal and relevant in terms of vital organ function and outcome. Regarding the critical role of heart failure in the pathophysiology of septic shock, our study also indicates a potentially new therapeutic approach for treatment of sepsis syndrome.


Assuntos
Membranas Intracelulares/efeitos dos fármacos , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/metabolismo , Peritonite/fisiopatologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sepse/fisiopatologia , Animais , Líquido da Lavagem Broncoalveolar , Caspases/metabolismo , Ciclosporina/farmacologia , Modelos Animais de Doenças , Imunossupressores/farmacologia , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Insuficiência de Múltiplos Órgãos/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Nitritos/sangue , Peritonite/metabolismo , Permeabilidade/efeitos dos fármacos , Sepse/metabolismo
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