DEBORA LEVY
Projetos de Pesquisa
Unidades Organizacionais
LIM/19 - Laboratório de Histocompatibilidade e Imunidade Celular, Hospital das Clínicas, Faculdade de Medicina
8 resultados
Resultados de Busca
Agora exibindo 1 - 8 de 8
- Antioxidant Properties and Cytoprotective Effect of Pistacia lentiscus L. Seed Oil against 7 beta-Hydroxycholesterol-Induced Toxicity in C2C12 Myoblasts: Reduction in Oxidative Stress, Mitochondrial and Peroxisomal Dysfunctions and Attenuation of Cell Death(2021) GHZAIEL, Imen; ZARROUK, Amira; NURY, Thomas; LIBERGOLI, Michela; FLORIO, Francesca; HAMMOUDA, Souha; MENETRIER, Franck; AVOSCAN, Laure; YAMMINE, Aline; SAMADI, Mohammad; LATRUFFE, Norbert; BIRESSI, Stefano; LEVY, Debora; BYDLOWSKI, Sergio Paulo; HAMMAMI, Sonia; VEJUX, Anne; HAMMAMI, Mohamed; LIZARD, GerardAging is characterized by a progressive increase in oxidative stress, which favors lipid peroxidation and the formation of cholesterol oxide derivatives, including 7 beta-hydroxycholesterol (7 beta-OHC). This oxysterol, which is known to trigger oxidative stress, inflammation, and cell death, could contribute to the aging process and age-related diseases, such as sarcopenia. Identifying molecules or mixtures of molecules preventing the toxicity of 7 beta-OHC is therefore an important issue. This study consists of determining the chemical composition of Tunisian Pistacia lentiscus L. seed oil (PLSO) used in the Tunisian diet and evaluating its ability to counteract the cytotoxic effects induced by 7 beta-OHC in murine C2C12 myoblasts. The effects of 7 beta-OHC (50 mu M; 24 h), associated or not with PLSO, were studied on cell viability, oxidative stress, and on mitochondrial and peroxisomal damages induction. alpha-Tocopherol (400 mu M) was used as the positive control for cytoprotection. Our data show that PLSO is rich in bioactive compounds; it contains polyunsaturated fatty acids, and several nutrients with antioxidant properties: phytosterols, alpha-tocopherol, carotenoids, flavonoids, and phenolic compounds. When associated with PLSO (100 mu g/mL), the 7 beta-OHC-induced cytotoxic effects were strongly attenuated. The cytoprotection was in the range of those observed with alpha-tocopherol. This cytoprotective effect was characterized by prevention of cell death and organelle dysfunction (restoration of cell adhesion, cell viability, and plasma membrane integrity; prevention of mitochondrial and peroxisomal damage) and attenuation of oxidative stress (reduction in reactive oxygen species overproduction in whole cells and at the mitochondrial level; decrease in lipid and protein oxidation products formation; and normalization of antioxidant enzyme activities: glutathione peroxidase (GPx) and superoxide dismutase (SOD)). These results provide evidence that PLSO has similar antioxidant properties than alpha-tocopherol used at high concentration and contains a mixture of molecules capable to attenuate 7 beta-OHC-induced cytotoxic effects in C2C12 myoblasts. These data reinforce the interest in edible oils associated with the Mediterranean diet, such as PLSO, in the prevention of age-related diseases, such as sarcopenia.
- Rare Pathogenic Variants in Mitochondrial and Inflammation-Associated Genes May Lead to Inflammatory Cardiomyopathy in Chagas Disease(2021) OUARHACHE, Maryem; MARQUET, Sandrine; FRADE, Amanda Farage; FERREIRA, Ariela Mota; IANNI, Barbara; ALMEIDA, Rafael Ribeiro; NUNES, Joao Paulo Silva; FERREIRA, Ludmila Rodrigues Pinto; RIGAUD, Vagner Oliveira-Carvalho; CANDIDO, Darlan; MADY, Charles; ZANIRATTO, Ricardo Costa Fernandes; BUCK, Paula; TORRES, Magali; GALLARDO, Frederic; ANDRIEUX, Pauline; BYDLOWSKY, Sergio; LEVY, Debora; ABEL, Laurent; CARDOSO, Clareci Silva; SANTOS-JUNIOR, Omar Ribeiro; OLIVEIRA, Lea Campos; OLIVEIRA, Claudia Di Lorenzo; NUNES, Maria Do Carmo; COBAT, Aurelie; KALIL, Jorge; RIBEIRO, Antonio Luiz; SABINO, Ester Cerdeira; CUNHA-NETO, Edecio; CHEVILLARD, ChristopheCardiomyopathies are an important cause of heart failure and sudden cardiac death. Little is known about the role of rare genetic variants in inflammatory cardiomyopathy. Chronic Chagas disease cardiomyopathy (CCC) is an inflammatory cardiomyopathy prevalent in Latin America, developing in 30% of the 6 million patients chronically infected by the protozoan Trypanosoma cruzi, while 60% remain free of heart disease (asymptomatic (ASY)). The cytokine interferon-gamma and mitochondrial dysfunction are known to play a major pathogenetic role. Chagas disease provides a unique model to probe for genetic variants involved in inflammatory cardiomyopathy. Methods We used whole exome sequencing to study nuclear families containing multiple cases of Chagas disease. We searched for rare pathogenic variants shared by all family members with CCC but absent in infected ASY siblings and in unrelated ASY. Results We identified heterozygous, pathogenic variants linked to CCC in all tested families on 22 distinct genes, from which 20 were mitochondrial or inflammation-related - most of the latter involved in proinflammatory cytokine production. Significantly, incubation with IFN-gamma on a human cardiomyocyte line treated with an inhibitor of dihydroorotate dehydrogenase brequinar (enzyme showing a loss-of-function variant in one family) markedly reduced mitochondrial membrane potential (Delta psi M), indicating mitochondrial dysfunction. Conclusion Mitochondrial dysfunction and inflammation may be genetically determined in CCC, driven by rare genetic variants. We hypothesize that CCC-linked genetic variants increase mitochondrial susceptibility to IFN-gamma-induced damage in the myocardium, leading to the cardiomyopathy phenotype in Chagas disease. This mechanism may also be operative in other inflammatory cardiomyopathies.
- Impairment of Multiple Mitochondrial Energy Metabolism Pathways in the Heart of Chagas Disease Cardiomyopathy Patients(2021) TEIXEIRA, Priscila Camillo; DUCRET, Axel; LANGEN, Hanno; NOGOCEKE, Everson; SANTOS, Ronaldo Honorato Barros; NUNES, Joao Paulo Silva; BENVENUTI, Luiz; LEVY, Debora; BYDLOWSKI, Sergio Paulo; BOCCHI, Edimar Alcides; TAKARA, Andreia Kuramoto; FIORELLI, Alfredo Inacio; STOLF, Noedir Antonio; POMERANZEFF, Pablo; CHEVILLARD, Christophe; KALIL, Jorge; CUNHA-NETO, EdecioChagas disease cardiomyopathy (CCC) is an inflammatory dilated cardiomyopathy occurring in 30% of the 6 million infected with the protozoan Trypanosoma cruzi in Latin America. Survival is significantly lower in CCC than ischemic (IC) and idiopathic dilated cardiomyopathy (DCM). Previous studies disclosed a selective decrease in mitochondrial ATP synthase alpha expression and creatine kinase activity in CCC myocardium as compared to IDC and IC, as well as decreased in vivo myocardial ATP production. Aiming to identify additional constraints in energy metabolism specific to CCC, we performed a proteomic study in myocardial tissue samples from CCC, IC and DCM obtained at transplantation, in comparison with control myocardial tissue samples from organ donors. Left ventricle free wall myocardial samples were subject to two-dimensional electrophoresis with fluorescent labeling (2D-DIGE) and protein identification by mass spectrometry. We found altered expression of proteins related to mitochondrial energy metabolism, cardiac remodeling, and oxidative stress in the 3 patient groups. Pathways analysis of proteins differentially expressed in CCC disclosed mitochondrial dysfunction, fatty acid metabolism and transmembrane potential of mitochondria. CCC patients' myocardium displayed reduced expression of 22 mitochondrial proteins belonging to energy metabolism pathways, as compared to 17 in DCM and 3 in IC. Significantly, 6 beta-oxidation enzymes were reduced in CCC, while only 2 of them were down-regulated in DCM and 1 in IC. We also observed that the cytokine IFN-gamma, previously described with increased levels in CCC, reduces mitochondrial membrane potential in cardiomyocytes. Results suggest a major reduction of mitochondrial energy metabolism and mitochondrial dysfunction in CCC myocardium which may be in part linked to IFN-gamma. This may partially explain the worse prognosis of CCC as compared to DCM or IC.
- Impact of Oxysterols on Cell Death, Proliferation, and Differentiation Induction: Current Status(2021) FREITAS, Fabio Alessandro de; LEVY, Debora; ZARROUK, Amira; LIZARD, Gerard; BYDLOWSKI, Sergio PauloOxysterols are oxidized derivatives of cholesterol produced by enzymatic activity or non-enzymatic pathways (auto-oxidation). The oxidation processes lead to the synthesis of about 60 different oxysterols. Several oxysterols have physiological, pathophysiological, and pharmacological activities. The effects of oxysterols on cell death processes, especially apoptosis, autophagy, necrosis, and oxiapoptophagy, as well as their action on cell proliferation, are reviewed here. These effects, also observed in several cancer cell lines, could potentially be useful in cancer treatment. The effects of oxysterols on cell differentiation are also described. Among them, the properties of stimulating the osteogenic differentiation of mesenchymal stem cells while inhibiting adipogenic differentiation may be useful in regenerative medicine.
- Co-Exposure of Cardiomyocytes to IFN-gamma and TNF-alpha Induces Mitochondrial Dysfunction and Nitro-Oxidative Stress: Implications for the Pathogenesis of Chronic Chagas Disease Cardiomyopathy(2021) NUNES, Joao Paulo Silva; ANDRIEUX, Pauline; BROCHET, Pauline; ALMEIDA, Rafael Ribeiro; KITANO, Eduardo; HONDA, Andre Kenji; IWAI, Leo Kei; ANDRADE-SILVA, Debora; GOUDENEGE, David; SILVA, Karla Deysiree Alcantara; VIEIRA, Raquel de Souza; LEVY, Debora; BYDLOWSKI, Sergio Paulo; GALLARDO, Frederic; TORRES, Magali; BOCCHI, Edimar Alcides; MANO, Miguel; SANTOS, Ronaldo Honorato Barros; BACAL, Fernando; POMERANTZEFF, Pablo; LAURINDO, Francisco Rafael Martins; TEIXEIRA, Priscila Camillo; NAKAYA, Helder I.; KALIL, Jorge; PROCACCIO, Vincent; CHEVILLARD, Christophe; CUNHA-NETO, EdecioInfection by the protozoan Trypanosoma cruzi causes Chagas disease cardiomyopathy (CCC) and can lead to arrhythmia, heart failure and death. Chagas disease affects 8 million people worldwide, and chronic production of the cytokines IFN-gamma and TNF-alpha by T cells together with mitochondrial dysfunction are important players for the poor prognosis of the disease. Mitochondria occupy 40% of the cardiomyocytes volume and produce 95% of cellular ATP that sustain the life-long cycles of heart contraction. As IFN-gamma and TNF-alpha have been described to affect mitochondrial function, we hypothesized that IFN-gamma and TNF-alpha are involved in the myocardial mitochondrial dysfunction observed in CCC patients. In this study, we quantified markers of mitochondrial dysfunction and nitro-oxidative stress in CCC heart tissue and in IFN-gamma/TNF-alpha-stimulated AC-16 human cardiomyocytes. We found that CCC myocardium displayed increased levels of nitro-oxidative stress and reduced mitochondrial DNA as compared with myocardial tissue from patients with dilated cardiomyopathy (DCM). IFN-gamma/TNF-alpha treatment of AC-16 cardiomyocytes induced increased nitro-oxidative stress and decreased the mitochondrial membrane potential (Delta psi m). We found that the STAT1/NF-kappa B/NOS2 axis is involved in the IFN-gamma/TNF-alpha-induced decrease of Delta psi m in AC-16 cardiomyocytes. Furthermore, treatment with mitochondria-sparing agonists of AMPK, NRF2 and SIRT1 rescues Delta psi m in IFN-gamma/TNF-alpha-stimulated cells. Proteomic and gene expression analyses revealed that IFN-gamma/TNF-alpha-treated cells corroborate mitochondrial dysfunction, transmembrane potential of mitochondria, altered fatty acid metabolism and cardiac necrosis/cell death. Functional assays conducted on Seahorse respirometer showed that cytokine-stimulated cells display decreased glycolytic and mitochondrial ATP production, dependency of fatty acid oxidation as well as increased proton leak and non-mitochondrial oxygen consumption. Together, our results suggest that IFN-gamma and TNF-alpha cause direct damage to cardiomyocytes' mitochondria by promoting oxidative and nitrosative stress and impairing energy production pathways. We hypothesize that treatment with agonists of AMPK, NRF2 and SIRT1 might be an approach to ameliorate the progression of Chagas disease cardiomyopathy.
- Protocol for qRT-PCR analysis from formalin fixed paraffin embedded tissue sections from diffuse large b-cell lymphoma: Validation of the six-gene predictor score(2016) TEKIN, Nilgun; OMIDVAR, Nader; MORRIS, Tim Peter; CONGET, Paulette; BRUNA, Flavia; TIMAR, Botond; GAGYI, Eva; BASAK, Ranjan; NAIK, Omkar; AUEWARKUL, Chirayu; SRITANA, Narongrit; LEVY, Debora; CERCI, Juliano Julio; BYDLOWSKI, Sergio Paulo; PEREIRA, Juliana; DIMAMAY, Mark Pierre; NATIVIDAD, Filipinas; CHUNG, June-Key; BELDER, Nevin; KUZU, Isinsu; PAEZ, Diana; DONDI, Maurizio; CARR, Robert; OZDAG, Hilal; PADUA, Rose AnnAs a part of an international study on the molecular analysis of Diffuse Large B-cell Lymphoma (DLBCL), a robust protocol for gene expression analysis from RNA extraction to qRT-PCR using Formalin Fixed Paraffin Embedded tissues was developed. Here a study was conducted to define a strategy to validate the previously reported 6-gene (LMO2, BCL6, FN1, CCND2, SCYA3 and BCL2) model as predictor of prognosis in DLBCL. To avoid variation, all samples were tested in a single centre and single platform. This study comprised 8 countries (Brazil, Chile, Hungary, India, Philippines, S. Korea, Thailand and Turkey). Using the Kaplan-Meier and log rank test on patients (n=162) and two mortality risk groups (with those above and below the mean representing high and low risk groups) confirmed that the 6-gene predictor score correlates significantly with overall survival (OS, p< 0.01) but not with event free survival (EFS, p= 0.18). Adding the International Prognostic Index (IPI) shows that the 6-gene predictor score correlates significantly with high IPI scores for OS (p< 0.05), whereas those with low IPI scores show a trend not reaching significance (p= 0.08). This study defined an effective and economical qRT-PCR strategy and validated the 6-gene score as a predictor of OS in an international setting.
- Chagas Disease Megaesophagus Patients Carrying Variant MRPS18B P260A Display Nitro-Oxidative Stress and Mitochondrial Dysfunction in Response to IFN-gamma Stimulus(2022) SILVA, Karla Deysiree Alcantara; NUNES, Joao Paulo Silva; ANDRIEUX, Pauline; BROCHET, Pauline; ALMEIDA, Rafael Ribeiro; TAKARA, Andreia Cristina Kazue Kuramoto; PEREIRA, Natalia Bueno; ABEL, Laurent; COBAT, Aurelie; ZANIRATTO, Ricardo Costa Fernandes; LEVY, Debora; BYDLOWSKI, Sergio Paulo; CECCONELLO, Ivan; SEGURO, Francisco Carlos Bernal da Costa; KALIL, Jorge; CHEVILLARD, Christophe; CUNHA-NETO, EdecioChagas disease (CD), caused by the protozoan parasite Trypanosoma cruzi, affects 8 million people, and around 1/3 develop chronic cardiac (CCC) or digestive disease (megaesophagus/megacolon), while the majority remain asymptomatic, in the indeterminate form of Chagas disease (ASY). Most CCC cases in families with multiple Chagas disease patients carry damaging mutations in mitochondrial genes. We searched for exonic mutations associated to chagasic megaesophagus (CME) in genes essential to mitochondrial processes. We performed whole exome sequencing of 13 CME and 45 ASY patients. We found the damaging variant MRPS18B 688C > G P230A, in five out of the 13 CME patients (one of them being homozygous; 38.4%), while the variant appeared in one out of 45 ASY patients (2.2%). We analyzed the interferon (IFN)-gamma-induced nitro-oxidative stress and mitochondrial function of EBV-transformed lymphoblastoid cell lines. We found the CME carriers of the mutation displayed increased levels of nitrite and nitrated proteins; in addition, the homozygous (G/G) CME patient also showed increased mitochondrial superoxide and reduced levels of ATP production. The results suggest that pathogenic mitochondrial mutations may contribute to cytokine-induced nitro-oxidative stress and mitochondrial dysfunction. We hypothesize that, in mutation carriers, IFN-gamma produced in the esophageal myenteric plexus might cause nitro-oxidative stress and mitochondrial dysfunction in neurons, contributing to megaesophagus.
conferenceObject DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL) STUDY REVEALS BIOLOGICAL HETEROGENEITY BETWEEN ETHNICALLY DIVERSE COUNTRIES; VALIDATION OF 6-GENE PROGNOSTIC SCORE IN AN INTERNATIONAL COHORT(2016) TEKIN, N.; OMIDVAR, N.; MORRIS, T.; TIMAR, B.; GAGYI, E.; CONGET, P.; BRUNA, F.; BASAK, R.; NAIK, O.; AUEWARAKUL, C. Udomsakdi; SRITANA, N.; LEVY, D.; BYDLOWSKI, S. P.; PEREIRA, J.; DIMAMAY, M. P.; NATIVIDAD, F.; CHUNG, J. K.; BELDER, N.; KUZU, I.; PAEZ, D.; DONDI, M.; CARR, R.; OZDAG, H.; PADUA, R. A.