Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
1.
Mech Ageing Dev ; 198: 111518, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34139214

RESUMO

INTRODUCTION: Aging represents a major risk factors for metabolic diseases, such as diabetes, obesity, or neurodegeneration. Polyphenols and their metabolites, especially simple phenolic acids, gained growing attention as a preventive strategy against age-related, non-communicable diseases, due to their hormetic potential. Using Caenorhabditis elegans (C. elegans) we investigate the effect of protocatechuic, gallic, and vanillic acid on mitochondrial function, health parameters, and the induction of potential hormetic pathways. METHODS: Lifespan, heat-stress resistance and chemotaxis of C. elegans strain P X 627, a specific model for aging, were assessed in 2-day and 10-day old nematodes. Mitochondrial membrane potential (ΔΨm) and ATP generation were measured. mRNA expression levels of longevity and energy metabolism-related genes were determined using qRT-PCR. RESULTS: All phenolic acids were able to significantly increase the nematodes lifespan, heat-stress resistance and chemotaxis at micromolar concentrations. While ΔΨm was only affected by age, vanillic acid (VA) significantly decreased ATP concentrations in aged nematodes. Longevity pathways, were activated by all phenolic acids, while VA also induced glycolytic activity and response to cold. CONCLUSION: While life- and health span parameters are positively affected by the investigated phenolic acids, the concentrations applied were unable to affect mitochondrial performance. Therefore we suggest a hormetic mode of action, especially by activation of the sirtuin-pathway.


Assuntos
Envelhecimento , Ácido Gálico/farmacologia , Hormese , Hidroxibenzoatos/farmacologia , Polifenóis/farmacologia , Ácido Vanílico/farmacologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/metabolismo , Animais , Anticarcinógenos/farmacologia , Caenorhabditis elegans , Quimiotaxia/efeitos dos fármacos , Quimiotaxia/fisiologia , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Aromatizantes/farmacologia , Resposta ao Choque Térmico/efeitos dos fármacos , Hormese/efeitos dos fármacos , Hormese/fisiologia , Longevidade/efeitos dos fármacos , Longevidade/genética , Redes e Vias Metabólicas/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Renovação Mitocondrial/fisiologia
2.
Biochem J ; 478(4): 749-764, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33626141

RESUMO

The incidence of cocaine abuse is increasing especially in the U.K. where the rates are among the highest in Europe. In addition to its role as a psychostimulant, cocaine has profound effect on brain metabolism, impacting glycolysis and impairing oxidative phosphorylation. Cocaine exposure alters metabolic gene expression and protein networks in brain regions including the prefrontal cortex, the ventral tegmental area and the nucleus accumbens, the principal nuclei of the brain reward system. Here, we focus on how cocaine impacts mitochondrial function, in particular through alterations in electron transport chain function, reactive oxygen species (ROS) production and oxidative stress (OS), mitochondrial dynamics and mitophagy. Finally, we describe the impact of cocaine on brain energy metabolism in the developing brain following prenatal exposure. The plethora of mitochondrial functions altered following cocaine exposure suggest that therapies maintaining mitochondrial functional integrity may hold promise in mitigating cocaine pathology and addiction.


Assuntos
Transtornos Relacionados ao Uso de Cocaína/metabolismo , Mitocôndrias/fisiologia , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/metabolismo , Cocaína/farmacologia , Cocaína/toxicidade , Metabolismo Energético/efeitos dos fármacos , Feminino , Glicólise/efeitos dos fármacos , Humanos , Camundongos , Necrose Dirigida por Permeabilidade Transmembrânica da Mitocôndria/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Biogênese de Organelas , Fosforilação Oxidativa/efeitos dos fármacos , Estresse Oxidativo , Gravidez , Complicações na Gravidez/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal , Ratos , Espécies Reativas de Oxigênio , Recompensa , Síndrome de Abstinência a Substâncias/metabolismo
3.
Oxid Med Cell Longev ; 2020: 3656419, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32765806

RESUMO

Curcumin has extensive therapeutic potential because of its antioxidant, anti-inflammatory, and antiproliferative properties. Multiple preclinical studies in vitro and in vivo have proven curcumin to be effective against various cancers. These potent effects are driven by curcumin's ability to induce G2/M cell cycle arrest, induce autophagy, activate apoptosis, disrupt molecular signaling, inhibit invasion and metastasis, and increase the efficacy of current chemotherapeutics. Here, we focus on the hormetic behavior of curcumin. Frequently, low doses of natural chemical products activate an adaptive stress response, whereas high doses activate acute responses like autophagy and cell death. This phenomenon is often referred to as hormesis. Curcumin causes cell death and primarily initiates an autophagic step (mitophagy). At higher doses, cells undergo mitochondrial destabilization due to calcium release from the endoplasmic reticulum, and die. Herein, we address the complex crosstalk that involves mitochondrial biogenesis, mitochondrial destabilization accompanied by mitophagy, and cell death.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Curcumina/uso terapêutico , Renovação Mitocondrial/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Curcumina/farmacologia , Humanos
4.
Acta Neuropathol Commun ; 8(1): 36, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32197663

RESUMO

Neurodegenerative disorders, including chemotherapy-induced cognitive impairment, are associated with neuronal mitochondrial dysfunction. Cisplatin, a commonly used chemotherapeutic, induces neuronal mitochondrial dysfunction in vivo and in vitro. Astrocytes are key players in supporting neuronal development, synaptogenesis, axonal growth, metabolism and, potentially mitochondrial health. We tested the hypothesis that astrocytes transfer healthy mitochondria to neurons after cisplatin treatment to restore neuronal health.We used an in vitro system in which astrocytes containing mito-mCherry-labeled mitochondria were co-cultured with primary cortical neurons damaged by cisplatin. Culture of primary cortical neurons with cisplatin reduced neuronal survival and depolarized neuronal mitochondrial membrane potential. Cisplatin induced abnormalities in neuronal calcium dynamics that were characterized by increased resting calcium levels, reduced calcium responses to stimulation with KCl, and slower calcium clearance. The same dose of cisplatin that caused neuronal damage did not affect astrocyte survival or astrocytic mitochondrial respiration. Co-culture of cisplatin-treated neurons with astrocytes increased neuronal survival, restored neuronal mitochondrial membrane potential, and normalized neuronal calcium dynamics especially in neurons that had received mitochondria from astrocytes which underlines the importance of mitochondrial transfer. These beneficial effects of astrocytes were associated with transfer of mitochondria from astrocytes to cisplatin-treated neurons. We show that siRNA-mediated knockdown of the Rho-GTPase Miro-1 in astrocytes reduced mitochondrial transfer from astrocytes to neurons and prevented the normalization of neuronal calcium dynamics.In conclusion, we showed that transfer of mitochondria from astrocytes to neurons rescues neurons from the damage induced by cisplatin treatment. Astrocytes are far more resistant to cisplatin than cortical neurons. We propose that transfer of functional mitochondria from astrocytes to neurons is an important repair mechanism to protect the vulnerable cortical neurons against the toxic effects of cisplatin.


Assuntos
Antineoplásicos/toxicidade , Astrócitos/efeitos dos fármacos , Cálcio/metabolismo , Cisplatino/toxicidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Animais , Astrócitos/metabolismo , Astrócitos/fisiologia , Sinalização do Cálcio , Respiração Celular/efeitos dos fármacos , Comprometimento Cognitivo Relacionado à Quimioterapia/etiologia , Comprometimento Cognitivo Relacionado à Quimioterapia/metabolismo , Técnicas de Cocultura , Técnicas de Silenciamento de Genes , Técnicas In Vitro , Substâncias Luminescentes , Proteínas Luminescentes , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Renovação Mitocondrial/efeitos dos fármacos , Neurônios/metabolismo , Síndromes Neurotóxicas , Imagem Óptica , Consumo de Oxigênio/efeitos dos fármacos , Cultura Primária de Células , Ratos , Proteínas rho de Ligação ao GTP/genética , Proteína Vermelha Fluorescente
5.
Physiol Rep ; 8(1): e14340, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31960608

RESUMO

Caffeine has been shown to directly increase fatty acid oxidation, in part, by promoting mitochondrial biogenesis. Mitochondrial biogenesis is often coupled with mitophagy, the autophagy-lysosomal degradation of mitochondria. Increased mitochondrial biogenesis and mitophagy promote mitochondrial turnover, which can enhance aerobic metabolism. In addition, recent studies have revealed that cellular lipid droplets can be directly utilized in an autophagy-dependent manner, a process known as lipophagy. Although caffeine has been shown to promote autophagy and mitochondrial biogenesis in skeletal muscles, it remains unclear whether caffeine can increase lipophagy and mitochondrial turnover in skeletal muscle as well. The purpose of this study was to determine the possible contribution of lipophagy to caffeine-dependent lipid utilization. Furthermore, we sought to determine whether caffeine could increase mitochondrial turnover, which may also contribute to elevated fatty acid oxidation. Treating fully differentiated C2C12 skeletal myotubes with 0.5 mM oleic acid (OA) for 24 hr promoted an approximate 2.5-fold increase in cellular lipid storage. Treating skeletal myotubes with 0.5 mM OA plus 0.5 mM caffeine for an additional 24 hr effectively returned cellular lipid stores to control levels, and this was associated with an increase in markers of autophagosomes and autophagic flux, as well as elevated autophagosome density in TEM images. The addition of autophagy inhibitors 3-methyladenine (10 mM) or bafilomycin A1 (10 µM) reduced caffeine-dependent lipid utilization by approximately 30%. However, fluorescence and transmission electron microscopy analysis revealed no direct evidence of lipophagy in skeletal myotubes, and there was also no lipophagy-dependent increase in fatty acid oxidation. Finally, caffeine treatment promoted an 80% increase in mitochondrial turnover, which coincided with a 35% increase in mitochondrial fragmentation. Our results suggest that caffeine administration causes an autophagy-dependent decrease in lipid content by increasing mitochondrial turnover in mammalian skeletal myotubes.


Assuntos
Autofagia/efeitos dos fármacos , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Adenina/análogos & derivados , Adenina/farmacologia , Animais , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Autofagossomos/ultraestrutura , Linhagem Celular , Ácidos Graxos/metabolismo , Citometria de Fluxo , Macrolídeos/farmacologia , Camundongos , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Dinâmica Mitocondrial/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/ultraestrutura , Mioblastos , Ácido Oleico/metabolismo , Biogênese de Organelas , Oxirredução , Consumo de Oxigênio
6.
Lab Invest ; 99(12): 1795-1809, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31570770

RESUMO

Sepsis-related acute lung injury (ALI) remains a major cause of mortality in critically ill patients and lacks specific therapy. Mitochondrial dysfunction is involved in the progression of septic lung injury. Mitochondrial dynamics, mitophagy, and biogenesis converge to constitute the assiduous quality control of mitochondria (MQC). Heme oxygenase-1 (HO-1) protects against sepsis-induced ALI through the modulation of mitochondrial dynamics. However, the causal relationship between HO-1 and the general processes of MQC, and their associated cellular pathways in sepsis-related ALI remain ill-defined. Herein, lipopolysaccharide (LPS)-induced ALI in Sprague-Dawley rats together with LPS-induced oxidative injury in RAW264.7 macrophages were used to investigate whether the PI3K/Akt pathway-mediated induction of HO-1 preserves MQC and alleviates septic lung injury. After pretreatment with hemin, a potent inducer of HO-1, LPS-induced cell apoptosis, enhanced mitochondrial fragmentation, and mitochondrial membrane potential damage were significantly reduced in macrophages. In rats, these effects were accompanied by a higher survival rate, less damage to lung tissue, a 28.5% elevation in lung mitochondria MnSOD activity, and a 39.2% increase in respiratory control ratios. Concomitantly, HO-1 induction preserved the dynamic process of mitochondrial fusion/fission (Mfn2, OPA1, Drp1), promoted mitochondrial biogenesis (NRF1, PGC1α, Tfam), and facilitated the key mediators of mitochondrial mitophagy (Parkin, PINK1) at mRNA and protein levels. Notably, LY294002, a PI3K inhibitor, or knockdown of PI3K by small interfering RNA significantly suppressed Akt phosphorylation, attenuated HO-1 induction, and further reversed these beneficial effects evoked by hemin pretreatment in RAW264.7 cells or rats received LPS, indicating a direct involvement of PI3K/Akt pathway. Taken together, our results indicated that HO-1 activation, through PI3K/Akt pathway, plays a critical role in protecting lung from oxidative injury in the setting of sepsis by regulating MQC. HO-1 may therefore be a therapeutic target for the prevention sepsis-related lung injury.


Assuntos
Lesão Pulmonar Aguda/prevenção & controle , Heme Oxigenase-1/metabolismo , Hemina/uso terapêutico , Renovação Mitocondrial/efeitos dos fármacos , Sepse/complicações , Lesão Pulmonar Aguda/etiologia , Animais , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática , Hemina/farmacologia , Lipopolissacarídeos , Pulmão/enzimologia , Masculino , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células RAW 264.7 , Ratos Sprague-Dawley , Transdução de Sinais
7.
Cell Death Dis ; 10(6): 421, 2019 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-31142733

RESUMO

Vacuole membrane protein (VMP1) is a putative autophagy protein, which together with Beclin-1 acts as a molecular switch in activating autophagy. In the present study the role of VMP1 was analysed in CD34+ cells of cord blood (CB) and primary acute myeloid leukemia (AML) cells and cell lines. An increased expression of VMP1 was observed in a subset of AML patients. Functional studies in normal CB CD34+ cells indicated that inhibiting VMP1 expression reduced autophagic-flux, coinciding with reduced expansion of hematopoietic stem and progenitor cells (HSPC), delayed differentiation, increased apoptosis and impaired in vivo engraftment. Comparable results were observed in leukemic cell lines and primary AML CD34+ cells. Ultrastructural analysis indicated that leukemic cells overexpressing VMP1 displayed a reduced number of mitochondrial structures, while the number of lysosomal degradation structures was increased. The overexpression of VMP1 did not affect cell proliferation and differentiation, but increased autophagic-flux and improved mitochondrial quality, which coincided with an increased threshold for venetoclax-induced loss of mitochondrial outer membrane permeabilization (MOMP) and apoptosis. In conclusion, our data indicate that in leukemic cells high VMP1 is involved with mitochondrial quality control.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Proteínas de Membrana/metabolismo , Sulfonamidas/farmacologia , Animais , Antígenos CD34/metabolismo , Pontos de Checagem do Ciclo Celular , Feminino , Sangue Fetal/citologia , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Renovação Mitocondrial/efeitos dos fármacos , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteína Sequestossoma-1/metabolismo
8.
J Mol Biol ; 430(24): 4823-4833, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30389435

RESUMO

Elamipretide is a tetrapeptide that restores defects in mitochondrial function, binds to cardiolipin, and is being tested in clinical trials for mitochondria-related diseases. However, whether elamipretide modulates mitochondrial quality control and dynamics, processes essential to preserve mitochondrial function, is unclear. Thus, we tested the effects of elamipretide on mitochondrial morphology, mitophagosome formation, and their early disruption induced by excess nutrients in INS1 ß-cells. Elamipretide treatment was sufficient to increase engulfment of mitochondria into autophagosomes in control INS1 ß-cells, without inducing widespread changes in mitochondrial morphology or membrane potential. In an early pathogenic context mimicked by short-term exposure to nutrient excess, elamipretide treatment prevented both mitochondrial fragmentation and defects in the engulfment of mitochondria into autophagosomes. On the other hand, elamipretide did not prevent lysosomal defects induced by nutrient excess. Accordingly, elamipretide treatment did not entail benefits on pathogenic p62 and LC3II accumulation or on insulin secretory function. In conclusion, our data show that elamipretide selectively stimulates the engulfment of mitochondria into autophagosomes and prevents its defects induced by nutrient excess. Thus, we propose that improved selectivity of mitochondrial quality control processes might contribute to the benefits stemming from elamipretide treatments in other disease models.


Assuntos
Autofagossomos/metabolismo , Células Secretoras de Insulina/citologia , Mitocôndrias/efeitos dos fármacos , Nutrientes/farmacologia , Oligopeptídeos/farmacologia , Linhagem Celular , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Lisossomos/metabolismo , Potencial da Membrana Mitocondrial , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/metabolismo , Renovação Mitocondrial/efeitos dos fármacos , Proteínas de Ligação a RNA/metabolismo
9.
Antiviral Res ; 133: 178-82, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27496003

RESUMO

Zidovudine (ZDV) is a widely used component of antiretroviral therapy (ART) in resource-limited settings, despite its known adverse effects, which include mitochondrial toxicity in muscle, liver and adipose tissue. It has also been associated with impaired immunological recovery. We hypothesised that ZDV might impair mitochondrial health and survival of primary T cells. We performed a cross-sectional analysis of mitochondrial function, mitophagy and susceptibility to apoptosis in healthy donor primary T cells after exposure to ZDV in vitro, together with T cells from patients who were virologically suppressed on ZDV-containing ART regimens for ≥1 year and age-matched subjects receiving non-ZDV ART regimens. The proportion of T cells expressing mitochondrial reactive oxygen species (mtROS) was significantly higher after in vitro (CD4(+) T cells and CD8(+) T cells) and in vivo (CD4(+) T cells) exposure to ZDV than other antiretroviral agents. We did not detect any effect of ZDV on mitophagy, as indicated by change in autophagic flux. However, spontaneous apoptosis, indicated by upregulation of caspase-3 was greater in ZDV-exposed T cells. In conclusion, ZDV exposure was associated with impaired mitochondrial turnover and increased susceptibility to apoptosis in T cells. These mechanisms could contribute to sub-optimal immune reconstitution.


Assuntos
Fármacos Anti-HIV/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Renovação Mitocondrial/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Zidovudina/farmacologia , Adulto , Idoso , Terapia Antirretroviral de Alta Atividade , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Contagem de Linfócito CD4 , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Linfócitos T/imunologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-27086599

RESUMO

Recent studies show that enhanced mitochondrial biogenesis can "fuel" the cancer cells to grow and migrate. It is therefore proposed that inhibiting the mitochondrial biogenesis could be a new approach to cancer therapy. This review summarizes recent patents and papers in the development of small molecule inhibitors of key regulators responsible for tumor mitochondrial biogenesis, including PPARγcoactivator-1α(PGC-1α), PPARγcoactivator-1ß, estrogen-related receptor family (ERRs), estrogen receptor α(ERα), mammalian target of rapamycin, c-Myc and PPARs.


Assuntos
Antineoplásicos/uso terapêutico , Mitocôndrias/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Biogênese de Organelas , Animais , Antineoplásicos/química , Descoberta de Drogas , Humanos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Estrutura Molecular , Terapia de Alvo Molecular , Neoplasias/metabolismo , Neoplasias/patologia , Patentes como Assunto , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
11.
Ann N Y Acad Sci ; 1350: 52-60, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26301952

RESUMO

Estrogen enhances mitochondrial function by enhancing mitochondrial biogenesis and sustaining mitochondrial energy-transducing capacity. Shifts in mitochondrial bioenergetic pathways from oxidative phosphorylation to glycolysis have been hypothesized to be involved in estrogen-induced tumorigenesis. Studies have shown that mitochondria are an important target of estrogen. Estrogen receptor-ß (ERß) has been shown to localize to mitochondria in a ligand-dependent or -independent manner and can affect mitochondrial bioenergetics and anti-apoptotic signaling. However, the functional role of mitochondrial ERß in tumorigenesis remains unclear. Clinical studies of ERß-related tumorigenesis have shown that ERß stimulates mitochondrial metabolism to meet the high energy demands of processes such as cell proliferation, cell survival, and transformation. Thus, in elucidating the precise role of mitochondrial ERß in cell transformation and tumorigenesis, it will be particularly valuable to explore new approaches for the development of medical treatments targeting mitochondrial ERß-mediated mitochondrial function and preventing apoptosis.


Assuntos
Carcinogênese/metabolismo , Metabolismo Energético , Receptor beta de Estrogênio/agonistas , Estrogênios/metabolismo , Mitocôndrias/metabolismo , Renovação Mitocondrial , Modelos Biológicos , Animais , Apoptose/efeitos dos fármacos , Carcinogênese/induzido quimicamente , Carcinógenos Ambientais/metabolismo , Carcinógenos Ambientais/toxicidade , Metabolismo Energético/efeitos dos fármacos , Receptor beta de Estrogênio/metabolismo , Estrogênios/efeitos adversos , Humanos , Ligantes , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Renovação Mitocondrial/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
12.
Am J Physiol Gastrointest Liver Physiol ; 309(1): G21-9, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25951827

RESUMO

Hepatic ischemia-reperfusion (I/R) can cause hepatocellular injury associated with the inflammatory response and mitochondrial dysfunction. We studied the protective effects of the phosphodiesterase inhibitor cilostazol in hepatic I/R and the roles of mitochondria and the Nrf2/heme oxygenase-1 (HO-1) system. Wild-type, Hmox1(-/-), or Nrf2(-/-) mice were subjected to hepatic I/R in the absence or presence of cilostazol followed by measurements of liver injury. Primary hepatocytes were subjected to cilostazol with the HO-1 inhibitor ZnPP, or Nrf2-specific siRNA, followed by assessment of mitochondrial biogenesis. Preconditioning with cilostazol prior to hepatic I/R protected against hepatocellular injury and mitochondrial dysfunction. Cilostazol reduced the serum levels of alanine aminotransferase, TNF-α, and liver myeloperoxidase content relative to control I/R-treated mice. In primary hepatocytes, cilostazol increased the expression of HO-1, and markers of mitochondrial biogenesis, PGC-1α, NRF-1, and TFAM, induced the mitochondrial proteins COX III and COX IV and increased mtDNA and mitochondria content. Pretreatment of primary hepatocytes with ZnPP inhibited cilostazol-induced PGC-1α, NRF-1, and TFAM mRNA expression and reduced mtDNA and mitochondria content. Genetic silencing of Nrf2 prevented the induction of HO-1 and mitochondrial biogenesis by cilostazol in HepG2 cells. Cilostazol induced hepatic HO-1 production and mitochondrial biogenesis in wild-type mice, but not in Hmox1(-/-) or Nrf2(-/-) mice, and failed to protect against liver injury in Nrf2(-/-) mice. These results suggest that I/R injury can impair hepatic mitochondrial function, which can be reversed by cilostazol treatment. These results also suggest that cilostazol-induced mitochondrial biogenesis was mediated by an Nrf-2- and HO-1-dependent pathway.


Assuntos
Heme Oxigenase-1/metabolismo , Fígado/irrigação sanguínea , Fígado/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Tetrazóis/farmacologia , Animais , Cilostazol , Citoproteção , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Heme Oxigenase-1/deficiência , Heme Oxigenase-1/genética , Células Hep G2 , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Humanos , Fígado/enzimologia , Fígado/patologia , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos Endogâmicos BALB C , Camundongos Knockout , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias Hepáticas/patologia , Fator 2 Relacionado a NF-E2/deficiência , Fator 2 Relacionado a NF-E2/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Inibidores da Fosfodiesterase 3/farmacologia , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
Toxicology ; 334: 1-11, 2015 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-25997894

RESUMO

Doxorubicin (DOX) is currently used in cancer chemotherapy, however, its use often results in adverse effects highlighted by the development of cardiomyopathy and ultimately heart failure. Interestingly, DOX cardiotoxicity is decreased by resveratrol or by physical activity, suggesting that increased mitochondrial activity may be protective. Conversely, recent studies showed that troglitazone, a PPARγ agonist, increases the cytotoxicity of DOX against breast cancer cells by up-regulating mitochondrial biogenesis. The hypothesis for the current investigation was that DOX cytotoxicity in H9c2 cardiomyoblasts is decreased when mitochondrial capacity is increased. We focused on several end-points for DOX cytotoxicity, including loss of cell mass, apoptotic signaling and alterations of autophagic-related proteins. Our results show that a galactose-based, modified cell culture medium increased H9c2 basal mitochondrial respiration, protein content, and mtDNA copy number without increasing maximal or spare respiratory capacity. H9c2 cardiomyoblasts cultured in the galactose-modified media showed lower DOX-induced activation of the apoptotic pathway, measured by decreased caspase-3 and -9 activation, and lower p53 expression, although ultimately loss of cells was not prevented. Treatment with the PPARγ agonist troglitazone had no effect on DOX toxicity in this cardiac cell line, which agrees with the fact that troglitazone did not increase mitochondrial DNA content or capacity at the concentrations and duration of exposure used in this investigation. Our results show that mitochondrial remodeling caused by stimulating basal rates of oxidative phosphorylation decreased DOX-induced apoptotic signaling and increased DOX-induced autophagy in H9c2 cardiomyoblasts. The differential effect on cytotoxicity in cardiac versus breast cancer cell lines suggests a possible overall improvement in the clinical efficacy for doxorubicin in treating cancer.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Doxorrubicina/toxicidade , Mitocôndrias Cardíacas/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Mioblastos Cardíacos/efeitos dos fármacos , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Respiração Celular/efeitos dos fármacos , Cromanos/farmacologia , Meios de Cultura/metabolismo , Replicação do DNA/efeitos dos fármacos , DNA Mitocondrial/biossíntese , Relação Dose-Resposta a Droga , Feminino , Humanos , Células MCF-7 , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Mioblastos Cardíacos/metabolismo , Mioblastos Cardíacos/patologia , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Ratos , Transdução de Sinais/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Fatores de Tempo , Troglitazona , Regulação para Cima
15.
Biochim Biophys Acta ; 1853(7): 1574-85, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25769432

RESUMO

Even though oxidative stress damage from excessive production of ROS is a well known phenomenon, the impact of reductive stress remains poorly understood. This study tested the hypothesis that cellular reductive stress could lead to mitochondrial malfunction, triggering a mitochondrial hormesis (mitohormesis) phenomenon able to protect mitochondria from the deleterious effects of statins. We performed several in vitro experiments on L6 myoblasts and studied the effects of N-acetylcysteine (NAC) at different exposure times. Direct NAC exposure (1mM) led to reductive stress, impairing mitochondrial function by decreasing maximal mitochondrial respiration and increasing H2O2production. After 24h of incubation, the reactive oxygen species (ROS) production was increased. The resulting mitochondrial oxidation activated mitochondrial biogenesis pathways at the mRNA level. After one week of exposure, mitochondria were well-adapted as shown by the decrease of cellular ROS, the increase of mitochondrial content, as well as of the antioxidant capacities. Atorvastatin (ATO) exposure (100µM) for 24h increased ROS levels, reduced the percentage of live cells, and increased the total percentage of apoptotic cells. NAC exposure during 3days failed to protect cells from the deleterious effects of statins. On the other hand, NAC pretreatment during one week triggered mitochondrial hormesis and reduced the deleterious effect of statins. These results contribute to a better understanding of the redox-dependant pathways linked to mitochondria, showing that reductive stress could trigger mitochondrial hormesis phenomenon.


Assuntos
Hormese , Mitocôndrias/metabolismo , Mioblastos/metabolismo , Estresse Fisiológico , Acetilcisteína/farmacologia , Animais , Respiração Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Hormese/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Mitocôndrias/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Mioblastos/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Ratos , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Fatores de Tempo
16.
Exp Physiol ; 100(1): 12-22, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25557727

RESUMO

NEW FINDINGS: What is the central question of this study? Does dietary quercetin enrichment improve biochemical and histological outcomes in hearts from mdx mice? What is the main finding and what is its importance? Biochemical and histological findings suggest that chronic quercetin feeding of mdx mice may improve mitochondrial function and attenuate tissue pathology. Patients with Duchenne muscular dystrophy suffer from cardiac pathology, which causes up to 40% of all deaths because of fibrosis and cardiac complications. Quercetin is a flavonol with anti-inflammatory and antioxidant effects and is also an activator of peroxisome proliferator-activated receptor γ coactivator 1α capable of antioxidant upregulation, mitochondrial biogenesis and prevention of cardiac complications. We sought to determine the extent to which dietary quercetin enrichment prevents (experiment 1) and rescues cardiac pathology (experiment 2) in mdx mice. In experiment 1, 3-week-old mdx mice were fed control chow (C3w6m, n = 10) or chow containing 0.2% quercetin for 6 months (Q3w6m, n = 10). In experiment 2, 3-month-old mdx mice were fed control chow (C3m6m, n = 10) or 0.2% chow containing 0.2% quercetin for 6 months (Q3m6m, n = 10). Hearts were excised for histological and biochemical analyses. In experiment 1, Western blot targets for mitochondrial biogenesis (cytochrome c, P = 0.007) and antioxidant expression (superoxide dismutase 2, P = 0.014) increased in Q3w6m mice compared with C3w6m. Histology revealed increased utrophin (P = 0.025) and decreased matrix metalloproteinase 9 abundance (P = 0.040) in Q3w6m mice compared with C3w6m. In experiment 2, relative (P = 0.023) and absolute heart weights (P = 0.020) decreased in Q3m6m mice compared with C3m6m. Indications of damage (Haematoxylin- and Eosin-stained sections, P = 0.007) and Western blot analysis of transforming growth factor ß1 (P = 0.009) were decreased in Q3m6m mice. Six months of quercetin feeding increased a mitochondrial biomarker, antioxidant protein and utrophin and decreased matrix metalloproteinase 9 in young mice. Given that these adaptations are associated with attenuated cardiac pathology and damage, the present findings may indicate that dietary quercetin enrichment attenuates dystrophic cardiac pathology, but physiological confirmation is needed.


Assuntos
Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/prevenção & controle , Suplementos Nutricionais , Mitocôndrias Cardíacas/efeitos dos fármacos , Distrofia Muscular Animal/tratamento farmacológico , Distrofia Muscular de Duchenne/tratamento farmacológico , Miocárdio/patologia , Quercetina/farmacologia , Animais , Cardiomiopatias/genética , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Citocromos c/metabolismo , Citoproteção , Modelos Animais de Doenças , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos mdx , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Renovação Mitocondrial/efeitos dos fármacos , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/metabolismo , Distrofia Muscular Animal/patologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patologia , Miocárdio/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Fator de Crescimento Transformador beta1/metabolismo , Utrofina/metabolismo
17.
Aging (Albany NY) ; 7(1): 38-52, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25596819

RESUMO

To elucidate gene expression pathways underlying age-associated impairment in influenza vaccine response, we screened young (age 21-30) and older (age≥65) adults receiving influenza vaccine in two consecutive seasons and identified those with strong or absent response to vaccine, including a subset of older adults meeting criteria for frailty. PBMCs obtained prior to vaccination (Day 0) and at day 2 or 4, day 7 and day 28 post-vaccine were subjected to gene expression microarray analysis. We defined a response signature and also detected induction of a type I interferon response at day 2 and a plasma cell signature at day 7 post-vaccine in young responders. The response signature was dysregulated in older adults, with the plasma cell signature induced at day 2, and was never induced in frail subjects (who were all non-responders). We also identified a mitochondrial signature in young vaccine responders containing genes mediating mitochondrial biogenesis and oxidative phosphorylation that was consistent in two different vaccine seasons and verified by analyses of mitochondrial content and protein expression. These results represent the first genome-wide transcriptional profiling analysis of age-associated dynamics following influenza vaccination, and implicate changes in mitochondrial biogenesis and function as a critical factor in human vaccine responsiveness.


Assuntos
Envelhecimento/genética , DNA Mitocondrial/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Leucócitos Mononucleares/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Vacinação , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/imunologia , Envelhecimento/metabolismo , Células Cultivadas , Feminino , Perfilação da Expressão Gênica/métodos , Estudo de Associação Genômica Ampla , Humanos , Influenza Humana/genética , Influenza Humana/imunologia , Influenza Humana/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Renovação Mitocondrial/efeitos dos fármacos , Renovação Mitocondrial/genética , Análise de Sequência com Séries de Oligonucleotídeos , Fosforilação Oxidativa/efeitos dos fármacos , Estações do Ano , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
18.
Cell Cycle ; 14(1): 56-63, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25483068

RESUMO

Despite extensive study, the mechanisms of cell fate choice upon p53 activation remain poorly understood. Using genome-wide shRNA screening, we recently identified the ATM kinase as synthetic lethal with Nutlin-3, an MDM2 inhibitor that leads to non-genotoxic p53 activation. Here, we demonstrate that while this synthetic lethal interaction relies upon components of both the intrinsic and extrinsic apoptotic pathways (e.g., BAX and BID), it is not due to significant ATM effects on the expression of p53 target genes. Instead, loss of ATM activity results in increased mitochondria and reactive oxygen species that drive apoptosis. Finally, we provide evidence that pharmacologic inhibition of ATM blocks autophagy in direct opposition to p53, which activates this process, and that inhibition of autophagy is sufficient to elicit an apoptotic response when combined with Nutlin-3.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Renovação Mitocondrial , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Autofagia/efeitos dos fármacos , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/antagonistas & inibidores , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Caspase 8/química , Caspase 8/genética , Caspase 8/metabolismo , Células HCT116 , Proteínas de Choque Térmico/metabolismo , Humanos , Imidazóis/farmacologia , Mitocôndrias/metabolismo , Renovação Mitocondrial/efeitos dos fármacos , Morfolinas/toxicidade , Proteínas Nucleares/metabolismo , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Pironas/toxicidade , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
19.
Biochim Biophys Acta ; 1851(3): 273-81, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25542506

RESUMO

α-Lipoic acid (α-Lip) is a natural occurring antioxidant with beneficial anti-obesity properties. The aim of this study was to investigate the putative effects of α-Lip on mitochondrial biogenesis and the acquirement of brown-like characteristics by subcutaneous adipocytes from overweight/obese subjects. Thus, fully differentiated human subcutaneous adipocytes were treated with α-Lip (100 and 250µM) for 24h for studies on mitochondrial content and morphology, mitochondrial DNA (mtDNA) copy number, fatty acid oxidation enzymes and brown/beige characteristic genes. The involvement of the Sirtuin1/Peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (SIRT1/PGC-1α) pathway was also evaluated. Our results showed that α-Lip increased mitochondrial content in cultured human adipocytes as revealed by electron microscopy and by mitotracker green labeling. Moreover, an enhancement in mtDNA content was observed. This increase was accompanied by an up-regulation of SIRT1 protein levels, a decrease in PGC-1α acetylation and up-regulation of Nuclear respiratory factor 1 (Nrf1) and Mitochondrial transcription factor (Tfam) transcription factors. Enhanced oxygen consumption and fatty acid oxidation enzymes, Carnitine palmitoyl transferase 1 and Acyl-coenzyme A oxidase (CPT-1 and ACOX) were also observed. Mitochondria from α-Lip-treated adipocytes exhibited some morphological characteristics of brown mitochondria, and α-Lip also induced up-regulation of some brown/beige adipocytes markers such as cell death-inducing DFFA-like effector a (Cidea) and T-box 1 (Tbx1). Moreover, α-Lip up-regulated PR domain containing 16 (Prdm16) mRNA levels in treated adipocytes. Therefore, our study suggests the ability of α-Lip to promote mitochondrial biogenesis and brown-like remodeling in cultured white subcutaneous adipocytes from overweight/obese donors.


Assuntos
Adipócitos Marrons/efeitos dos fármacos , Antioxidantes/farmacologia , Mitocôndrias/efeitos dos fármacos , Renovação Mitocondrial/efeitos dos fármacos , Ácido Tióctico/farmacologia , Acetilação/efeitos dos fármacos , Adipócitos Marrons/metabolismo , Adipócitos Marrons/patologia , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Diferenciação Celular , Variações do Número de Cópias de DNA/efeitos dos fármacos , DNA Mitocondrial/agonistas , DNA Mitocondrial/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Fator 1 Nuclear Respiratório/genética , Fator 1 Nuclear Respiratório/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Oxirredutases/genética , Oxirredutases/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Cultura Primária de Células , Transdução de Sinais , Sirtuína 1/genética , Sirtuína 1/metabolismo , Gordura Subcutânea/efeitos dos fármacos , Gordura Subcutânea/metabolismo , Gordura Subcutânea/patologia , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
20.
Diabetes Obes Metab ; 17(1): 52-60, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25200673

RESUMO

AIM: To determine the effect of pioglitazone treatment on in vivo and ex vivo muscle mitochondrial function in a rat model of diabetes. METHODS: Both the lean, healthy rats and the obese, diabetic rats are Zucker Diabetic Fatty (ZDF) rats. The homozygous fa/fa ZDF rats are obese and diabetic. The heterozygous fa/+ ZDF rats are lean and healthy. Diabetic Zucker Diabetic Fatty rats were treated with either pioglitazone (30 mg/kg/day) or water as a control (n = 6 per group), for 2 weeks. In vivo ¹H and ³¹P magnetic resonance spectroscopy was performed on skeletal muscle to assess intramyocellular lipid (IMCL) content and muscle oxidative capacity, respectively. Ex vivo muscle mitochondrial respiratory capacity was evaluated using high-resolution respirometry. In addition, several markers of mitochondrial content were determined. RESULTS: IMCL content was 14-fold higher and in vivo muscle oxidative capacity was 26% lower in diabetic rats compared with lean rats, which was, however, not caused by impairments of ex vivo mitochondrial respiratory capacity or a lower mitochondrial content. Pioglitazone treatment restored in vivo muscle oxidative capacity in diabetic rats to the level of lean controls. This amelioration was not accompanied by an increase in mitochondrial content or ex vivo mitochondrial respiratory capacity, but rather was paralleled by an improvement in lipid homeostasis, that is lowering of plasma triglycerides and muscle lipid and long-chain acylcarnitine content. CONCLUSION: Diminished in vivo muscle oxidative capacity in diabetic rats results from mitochondrial lipid overload and can be alleviated by redirecting the lipids from the muscle into adipose tissue using pioglitazone treatment.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metabolismo dos Lipídeos/efeitos dos fármacos , Doenças Mitocondriais/prevenção & controle , Músculo Esquelético/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Tiazolidinedionas/uso terapêutico , Animais , Biomarcadores/metabolismo , Carnitina/análogos & derivados , Carnitina/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Hipertrigliceridemia/complicações , Hipertrigliceridemia/prevenção & controle , Hipoglicemiantes/efeitos adversos , Hipolipemiantes/uso terapêutico , Masculino , Mitocôndrias Musculares/efeitos dos fármacos , Mitocôndrias Musculares/metabolismo , Doenças Mitocondriais/complicações , Renovação Mitocondrial/efeitos dos fármacos , Músculo Esquelético/metabolismo , Obesidade/complicações , Fosforilação Oxidativa/efeitos dos fármacos , PPAR gama/antagonistas & inibidores , Pioglitazona , Ratos Zucker , Tiazolidinedionas/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...