PAULO MAGNO MARTINS DOURADO
Projetos de Pesquisa
Unidades Organizacionais
10 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 10
- Exercise reestablishes autophagic flux and mitochondrial quality control in heart failure(2017) CAMPOS, Juliane C.; QUELICONI, Bruno B.; BOZI, Luiz H. M.; BECHARA, Luiz R. G.; DOURADO, Paulo M. M.; ANDRES, Allen M.; JANNIG, Paulo R.; GOMES, Katia M. S.; ZAMBELLI, Vanessa O.; ROCHA-RESENDE, Cibele; GUATIMOSIM, Silvia; BRUM, Patricia C.; MOCHLY-ROSEN, Daria; GOTTLIEB, Roberta A.; KOWALTOWSKI, Alicia J.; FERREIRA, Julio C. B.We previously reported that facilitating the clearance of damaged mitochondria through macroautophagy/autophagy protects against acute myocardial infarction. Here we characterize the impact of exercise, a safe strategy against cardiovascular disease, on cardiac autophagy and its contribution to mitochondrial quality control, bioenergetics and oxidative damage in a post-myocardial infarction-induced heart failure animal model. We found that failing hearts displayed reduced autophagic flux depicted by accumulation of autophagy-related markers and loss of responsiveness to chloroquine treatment at 4 and 12 wk after myocardial infarction. These changes were accompanied by accumulation of fragmented mitochondria with reduced O-2 consumption, elevated H2O2 release and increased Ca2+-Cinduced mitochondrial permeability transition pore opening. Of interest, disruption of autophagic flux was sufficient to decrease cardiac mitochondrial function in sham-treated animals and increase cardiomyocyte toxicity upon mitochondrial stress. Importantly, 8 wk of exercise training, starting 4 wk after myocardial infarction at a time when autophagy and mitochondrial oxidative capacity were already impaired, improved cardiac autophagic flux. These changes were followed by reduced mitochondrial number: size ratio, increased mitochondrial bioenergetics and better cardiac function. Moreover, exercise training increased cardiac mitochondrial number, size and oxidative capacity without affecting autophagic flux in sham-treated animals. Further supporting an autophagy mechanism for exercise-induced improvements of mitochondrial bioenergetics in heart failure, acute in vivo inhibition of autophagic flux was sufficient to mitigate the increased mitochondrial oxidative capacity triggered by exercise in failing hearts. Collectively, our findings uncover the potential contribution of exercise in restoring cardiac autophagy flux in heart failure, which is associated with better mitochondrial quality control, bioenergetics and cardiac function.
- High- versus moderate-intensity aerobic exercise training effects on skeletal muscle of infarcted rats(2013) MOREIRA, Jose B. N.; BECHARA, Luiz R. G.; BOZI, Luiz H. M.; JANNIG, Paulo R.; MONTEIRO, Alex W. A.; DOURADO, Paulo M.; WISLOFF, Ulrik; BRUM, Patricia C.Moreira JB, Bechara LR, Bozi LH, Jannig PR, Monteiro AW, Dourado PM, Wisloff U, Brum PC. High- versus moderate-intensity aerobic exercise training effects on skeletal muscle of infarcted rats. J Appl Physiol 114: 1029-1041, 2013. First published February 21, 2013; doi:10.1152/japplphysiol.00760.2012.-Poor skeletal muscle performance was shown to strongly predict mortality and long-term prognosis in a variety of diseases, including heart failure (HF). Despite the known benefits of aerobic exercise training (AET) in improving the skeletal muscle phenotype in HF, the optimal exercise intensity to elicit maximal outcomes is still under debate. Therefore, the aim of the present study was to compare the effects of high-intensity AET with those of a moderate-intensity protocol on skeletal muscle of infarcted rats. Wistar rats underwent myocardial infarction (MI) or sham surgery. MI groups were submitted either to an untrained (MI-UNT); moderate-intensity (MI-CMT, 60% (V) over dot(O2) (max)); or matched volume, high-intensity AET (MI-HIT, intervals at 85% (V) over dot(O2) (max)) protocol. High-intensity AET (HIT) was superior to moderate-intensity AET (CMT) in improving aerobic capacity, assessed by treadmill running tests. Cardiac contractile function, measured by echocardiography, was equally improved by both AET protocols. CMT and HIT prevented the MI-induced decay of skeletal muscle citrate synthase and hexokinase maximal activities, and increased glycogen content, without significant differences between protocols. Similar improvements in skeletal muscle redox balance and deactivation of the ubiquitin-proteasome system were also observed after CMT and HIT. Such intracellular findings were accompanied by prevented skeletal muscle atrophy in both MI-CMT and MI-HIT groups, whereas no major differences were observed between protocols. Taken together, our data suggest that despite superior effects of HIT in improving functional capacity, skeletal muscle adaptations were remarkably similar among protocols, leading to the conclusion that skeletal myopathy in infarcted rats was equally prevented by either moderate-intensity or high-intensity AET.
- Exercise training decreases NADPH oxidase activity and restores skeletal muscle mass in heart failure rats(2017) CUNHA, Telma F.; BECHARA, Luiz R. G.; BACURAU, Aline V. N.; JANNIG, Paulo R.; VOLTARELLI, Vanessa A.; DOURADO, Paulo M.; VASCONCELOS, Andrea R.; SCAVONE, Cristoforo; FERREIRA, Julio C. B.; BRUM, Patricia C.We have recently demonstrated that NADPH oxidase hyperactivity, NF-kappa B activation, and increased p38 phosphorylation lead to atrophy of glycolytic muscle in heart failure (HF). Aerobic exercise training (AET) is an efficient strategy to counteract skeletal muscle atrophy in this syndrome. Therefore, we tested whether AET would regulate muscle redox balance and protein degradation by decreasing NADPH oxidase hyperactivity and reestablishing NF-kappa B signaling, p38 phosphorylation, and proteasome activity in plantaris muscle of myocardial infarcted-induced HF (MI) rats. Thirty-two male Wistar rats underwent MI or fictitious surgery (SHAM) and were randomly assigned into untrained (UNT) and trained (T; 8 wk of AET on treadmill) groups. AET prevented HF signals and skeletal muscle atrophy in MI-T, which showed an improved exercise tolerance, attenuated cardiac dysfunction and increased plantaris fiber cross-sectional area. To verify the role of inflammation and redox imbalance in triggering protein degradation, circulating TNF-alpha levels, NADPH oxidase profile, NF-kappa B signaling, p38 protein levels, and proteasome activity were assessed. MI-T showed a reduced TNF-alpha levels, NADPH oxidase activity, and Nox2 mRNA expression toward SHAM-UNT levels. The rescue of NADPH oxidase activity induced by AET in MI rats was paralleled by reducing nuclear binding activity of the NF-kappa B, p38 phosphorylation, atrogin-1, mRNA levels, and 26S chymotrypsin-like proteasome activity. Taken together our data provide evidence for AET improving plantaris redox homeostasis in HF associated with a decreased NADPH oxidase, redox-sensitive proteins activation, and proteasome hyperactivity further preventing atrophy. These data reinforce the role of AET as an efficient therapy for muscle wasting in HF. NEW & NOTEWORTHY This study demonstrates, for the first time, the contribution of aerobic exercise training (AET) in decreasing muscle NADPH oxidase activity associated with reduced reactive oxygen species production and systemic inflammation, which diminish NF-kappa B overactivation, p38 phosphorylation, and ubiquitin proteasome system hyperactivity. These molecular changes counteract plantaris atrophy in trained myocardial infarction-induced heart failure rats. Our data provide new evidence into how AET may regulate protein degradation and thus prevent skeletal muscle atrophy.
- Lack of beta(2)-adrenoceptors aggravates heart failure-induced skeletal muscle myopathy in mice(2014) VOLTARELLI, Vanessa A.; BECHARA, Luiz R. G.; BACURAU, Aline V. N.; MATTOS, Katt C.; DOURADO, Paulo M. M.; BUENO JR., Carlos R.; CASARINI, Dulce E.; NEGRAO, Carlos E.; BRUM, Patricia C.Skeletal myopathy is a hallmark of heart failure (HF) and has been associated with a poor prognosis. HF and other chronic degenerative diseases share a common feature of a stressed system: sympathetic hyperactivity. Although beneficial acutely, chronic sympathetic hyperactivity is one of the main triggers of skeletal myopathy in HF. Considering that (2)-adrenoceptors mediate the activity of sympathetic nervous system in skeletal muscle, we presently evaluated the contribution of (2)-adrenoceptors for the morphofunctional alterations in skeletal muscle and also for exercise intolerance induced by HF. Male WT and (2)-adrenoceptor knockout mice on a FVB genetic background (2KO) were submitted to myocardial infarction (MI) or SHAM surgery. Ninety days after MI both WT and 2KO mice presented to cardiac dysfunction and remodelling accompanied by significantly increased norepinephrine and epinephrine plasma levels, exercise intolerance, changes towards more glycolytic fibres and vascular rarefaction in plantaris muscle. However, 2KO MI mice displayed more pronounced exercise intolerance and skeletal myopathy when compared to WT MI mice. Skeletal muscle atrophy of infarcted 2KO mice was paralleled by reduced levels of phosphorylated Akt at Ser 473 while increased levels of proteins related with the ubiquitin--proteasome system, and increased 26S proteasome activity. Taken together, our results suggest that lack of (2)-adrenoceptors worsen and/or anticipate the skeletal myopathy observed in HF.
- Aldehydic load and aldehyde dehydrogenase 2 profile during the progression of post-myocardial infarction cardiomyopathy: Benefits of Alda-1(2015) GOMES, Katia M. S.; BECHARA, Luiz R. G.; LIMA, Vanessa M.; RIBEIRO, Marcio A. C.; CAMPOS, Juliane C.; DOURADO, Paulo M.; KOWALTOWSKI, Alicia J.; MOCHLY-ROSEN, Daria; FERREIRA, Julio C. B.Background/objectives: We previously demonstrated that reducing cardiac aldehydic load by aldehyde dehydrogenase 2 (ALDH2), a mitochondrial enzyme responsible for metabolizing the major lipid peroxidation product, protects against acute ischemia/reperfusion injury and chronic heart failure. However, time-dependent changes in ALDH2 profile, aldehydic load and mitochondrial bioenergetics during progression of post-myocardial infarction (post-MI) cardiomyopathy are unknown and should be established to determine the optimal time window for drug treatment. Methods: Here we characterized cardiac ALDH2 activity and expression, lipid peroxidation, 4-hydroxy-2-nonenal (4-HNE) adduct formation, glutathione pool and mitochondrial energy metabolism and H2O2 release during the 4 weeks after permanent left anterior descending (LAD) coronary artery occlusion in rats. Results: We observed a sustained disruption of cardiac mitochondrial function during the progression of post-MI cardiomyopathy, characterized by >50% reduced mitochondrial respiratory control ratios and up to 2 fold increase in H2O2 release. Mitochondrial dysfunction was accompanied by accumulation of cardiac and circulating lipid peroxides and 4-HNE protein adducts and down-regulation of electron transport chain complexes I and V. Moreover, increased aldehydic load was associated with a 90% reduction in cardiac ALDH2 activity and increased glutathione pool. Further supporting an ALDH2 mechanism, sustained Alda-1 treatment (starting 24 h after permanent LAD occlusion surgery) prevented aldehydic overload, mitochondrial dysfunction and improved ventricular function in post-MI cardiomyopathy rats. Conclusion: Taken together, our findings demonstrate a disrupted mitochondrial metabolism along with an insufficient cardiac ALDH2-mediated aldehyde clearance during the progression of ventricular dysfunction, suggesting a potential therapeutic value of ALDH2 activators during the progression of post-myocardial infarction cardiomyopathy.
- Aldehyde dehydrogenase 2 activation in heart failure restores mitochondrial function and improves ventricular function and remodelling(2014) GOMES, Katia M. S.; CAMPOS, Juliane C.; BECHARA, Luiz R. G.; QUELICONI, Bruno; LIMA, Vanessa M.; DISATNIK, Marie-Helene; MAGNO, Paulo; CHEN, Che-Hong; BRUM, Patricia C.; KOWALTOWSKI, Alicia J.; MOCHLY-ROSEN, Daria; FERREIRA, Julio C. B.Aims We previously demonstrated that pharmacological activation of mitochondrial aldehyde dehydrogenase 2 (ALDH2) protects the heart against acute ischaemia/reperfusion injury. Here, we determined the benefits of chronic activation of ALDH2 on the progression of heart failure (HF) using a post-myocardial infarction model. Methods and results We showed that a 6-week treatment of myocardial infarction-induced HF rats with a selective ALDH2 activator (Alda-1), starting 4 weeks after myocardial infarction at a time when ventricular remodelling and cardiac dysfunction were present, improved cardiomyocyte shortening, cardiac function, left ventricular compliance and diastolic function under basal conditions, and after isoproterenol stimulation. Importantly, sustained Alda-1 treatment showed no toxicity and promoted a cardiac anti-remodelling effect by suppressing myocardial hypertrophy and fibrosis. Moreover, accumulation of 4-hydroxynonenal (4-HNE)-protein adducts and protein carbonyls seen in HF was not observed in Alda-1-treated rats, suggesting that increasing the activity of ALDH2 contributes to the reduction of aldehydic load in failing hearts. ALDH2 activation was associated with improved mitochondrial function, including elevated mitochondrial respiratory control ratios and reduced H2O2 release. Importantly, selective ALDH2 activation decreased mitochondrial Ca2+-induced permeability transition and cytochromec release in failing hearts. Further supporting a mitochondrial mechanism for ALDH2, Alda-1 treatment preserved mitochondrial function upon in vitro aldehydic load. Conclusions Selective activation of mitochondrial ALDH2 is sufficient to improve the HF outcome by reducing the toxic effects of aldehydic overload on mitochondrial bioenergetics and reactive oxygen species generation, suggesting that ALDH2 activators, such as Alda-1, have a potential therapeutic value for treating HF patients.
- NADPH oxidase hyperactivity induces plantaris atrophy in heart failure rats(2014) BECHARA, Luiz R. G.; MOREIRA, Jose B. N.; JANNIG, Paulo R.; VOLTARELLI, Vanessa A.; DOURADO, Paulo M.; VASCONCELOS, Andrea R.; SCAVONE, Cristoforo; RAMIRES, Paulo R.; BRUM, Patricia C.Background: Skeletal muscle wasting is associated with poor prognosis and increased mortality in heart failure (HF) patients. Glycolytic muscles are more susceptible to catabolic wasting than oxidative ones. This is particularly important in HF since glycolytic muscle wasting is associated with increased levels of reactive oxygen species (ROS). However, the main ROS sources involved in muscle redox imbalance in HF have not been characterized. Therefore, we hypothesized that NADPH oxidases would be hyperactivated in the plantaris muscle of infarcted rats, contributing to oxidative stress and hyperactivation of the ubiquitin-proteasome system(UPS), ultimately leading to atrophy. Methods: Rats were submitted to myocardial infarction (MI) or Sham surgery. Four weeks after surgery, MI and Sham groups underwent eight weeks of treatment with apocynin, a NADPH oxidase inhibitor, or placebo. NADPH oxidase activity, oxidative stress markers, NF-kappa B activity, p38 MAPK phosphorylation, mRNA and sarcolemmal protein levels of NADPH oxidase components, UPS activation and fiber cross-sectional area were assessed in the plantaris muscle. Results: The plantaris of MI rats displayed atrophy associated with increased Nox2 mRNA and sarcolemmal protein levels, NADPH oxidase activity, ROS production, lipid hydroperoxides levels, NF-kappa B activity, p38 MAPK phosphorylation and UPS activation. NADPH oxidase inhibition by apocynin prevented MI-induced skeletal muscle atrophy by reducing ROS production, NF-kappa B hyperactivation, p38 MAPK phosphorylation and proteasomal hyperactivity. Conclusion: Our data provide evidence for NADPH oxidase hyperactivation as an important source of ROS production leading to plantaris atrophy in heart failure rats, suggesting that this enzyme complex plays key role in skeletal muscle wasting in HF.
- A selective inhibitor of mitofusin 1-beta IIPKC association improves heart failure outcome in rats(2019) FERREIRA, Julio C. B.; CAMPOS, Juliane C.; QVIT, Nir; QI, Xin; BOZI, Luiz H. M.; BECHARA, Luiz R. G.; LIMA, Vanessa M.; QUELICONI, Bruno B.; DISATNIK, Marie-Helene; DOURADO, Paulo M. M.; KOWALTOWSKI, Alicia J.; MOCHLY-ROSEN, DariaWe previously demonstrated that beta II protein kinase C (beta IIPKC) activity is elevated in failing hearts and contributes to this pathology. Here we report that beta IIPKC accumulates on the mitochondrial outer membrane and phosphorylates mitofusin 1 (Mfn1) at serine 86. Mfn1 phosphorylation results in partial loss of its GTPase activity and in a buildup of fragmented and dysfunctional mitochondria in heart failure. beta IIPKC siRNA or a beta IIPKC inhibitor mitigates mitochondrial fragmentation and cell death. We confirm that Mfn1-beta IIPKC interaction alone is critical in inhibiting mitochondrial function and cardiac myocyte viability using SAM beta A, a rationally-designed peptide that selectively antagonizes Mfn1-ss IIPKC association. SAM beta A treatment protects cultured neonatal and adult cardiac myocytes, but not Mfn1 knockout cells, from stress-induced death. Importantly, SAM beta A treatment re-establishes mitochondrial morphology and function and improves cardiac contractility in rats with heart failure, suggesting that SAM beta A may be a potential treatment for patients with heart failure.
- Autophagy Signaling in Skeletal Muscle of Infarcted Rats(2014) JANNIG, Paulo R.; MOREIRA, Jose B. N.; BECHARA, Luiz R. G.; BOZI, Luiz H. M.; BACURAU, Aline V.; MONTEIRO, Alex W. A.; DOURADO, Paulo M.; WISLOFF, Ulrik; BRUM, Patricia C.Background: Heart failure (HF)-induced skeletal muscle atrophy is often associated to exercise intolerance and poor prognosis. Better understanding of the molecular mechanisms underlying HF-induced muscle atrophy may contribute to the development of pharmacological strategies to prevent or treat such condition. It has been shown that autophagy-lysosome system is an important mechanism for maintenance of muscle mass. However, its role in HF-induced myopathy has not been addressed yet. Therefore, the aim of the present study was to evaluate autophagy signaling in myocardial infarction (MI)-induced muscle atrophy in rats. Methods/Principal Findings: Wistar rats underwent MI or Sham surgeries, and after 12 weeks were submitted to echocardiography, exercise tolerance and histology evaluations. Cathepsin L activity and expression of autophagy-related genes and proteins were assessed in soleus and plantaris muscles by fluorimetric assay, qRT-PCR and immunoblotting, respectively. MI rats displayed exercise intolerance, left ventricular dysfunction and dilation, thereby suggesting the presence of HF. The key findings of the present study were: a) upregulation of autophagy-related genes (GABARAPL1, ATG7, BNIP3, CTSL1 and LAMP2) was observed only in plantaris while muscle atrophy was observed in both soleus and plantaris muscles, and b) Cathepsin L activity, Bnip3 and Fis1 protein levels, and levels of lipid hydroperoxides were increased specifically in plantaris muscle of MI rats. Conclusions: Altogether our results provide evidence for autophagy signaling regulation in HF-induced plantaris atrophy but not soleus atrophy. Therefore, autophagy-lysosome system is differentially regulated in atrophic muscles comprising different fiber-types and metabolic characteristics.
- Exercise Training Restores Cardiac Protein Quality Control in Heart Failure(2012) CAMPOS, Juliane C.; QUELICONI, Bruno B.; DOURADO, Paulo M. M.; CUNHA, Telma F.; ZAMBELLI, Vanessa O.; BECHARA, Luiz R. G.; KOWALTOWSKI, Alicia J.; BRUM, Patricia C.; MOCHLY-ROSEN, Daria; FERREIRA, Julio C. B.Exercise training is a well-known coadjuvant in heart failure treatment; however, the molecular mechanisms underlying its beneficial effects remain elusive. Despite the primary cause, heart failure is often preceded by two distinct phenomena: mitochondria dysfunction and cytosolic protein quality control disruption. The objective of the study was to determine the contribution of exercise training in regulating cardiac mitochondria metabolism and cytosolic protein quality control in a post-myocardial infarction-induced heart failure (MI-HF) animal model. Our data demonstrated that isolated cardiac mitochondria from MI-HF rats displayed decreased oxygen consumption, reduced maximum calcium uptake and elevated H2O2 release. These changes were accompanied by exacerbated cardiac oxidative stress and proteasomal insufficiency. Declined proteasomal activity contributes to cardiac protein quality control disruption in our MI-HF model. Using cultured neonatal cardiomyocytes, we showed that either antimycin A or H2O2 resulted in inactivation of proteasomal peptidase activity, accumulation of oxidized proteins and cell death, recapitulating our in vivo model. Of interest, eight weeks of exercise training improved cardiac function, peak oxygen uptake and exercise tolerance in MI-HF rats. Moreover, exercise training restored mitochondrial oxygen consumption, increased Ca2+-induced permeability transition and reduced H2O2 release in MI-HF rats. These changes were followed by reduced oxidative stress and better cardiac protein quality control. Taken together, our findings uncover the potential contribution of mitochondrial dysfunction and cytosolic protein quality control disruption to heart failure and highlight the positive effects of exercise training in re-establishing cardiac mitochondrial physiology and protein quality control, reinforcing the importance of this intervention as a nonpharmacological tool for heart failure therapy.