RESUMO
Nutrient excess increases skeletal muscle oxidant production and mitochondrial fragmentation that may result in impaired mitochondrial function, a hallmark of skeletal muscle insulin resistance. This led us to explore whether an endogenous gas molecule, carbon monoxide (CO), which is thought to prevent weight gain and metabolic dysfunction in mice consuming high-fat diets, alters mitochondrial morphology and respiration in C2C12 myoblasts exposed to high glucose (15.6 mM) and high fat (250 µM BSA-palmitate) (HGHF). Also, skeletal muscle mitochondrial morphology, distribution, respiration, and energy expenditure were examined in obese resistant (OR) and obese prone (OP) rats that consumed a high-fat and high-sucrose diet for 10 wk with or without intermittent low-dose inhaled CO and/or exercise training. In cells exposed to HGHF, superoxide production, mitochondrial membrane potential (ΔΨm), mitochondrial fission regulatory protein dynamin-related protein 1 (Drp1) and mitochondrial fragmentation increased, while mitochondrial respiratory capacity was reduced. CO decreased HGHF-induced superoxide production, Drp1 protein levels and mitochondrial fragmentation, maintained ΔΨm, and increased mitochondrial respiratory capacity. In comparison with lean OR rats, OP rats had smaller skeletal muscle mitochondria that contained disorganized cristae, a normal mitochondrial distribution, but reduced citrate synthase protein expression, normal respiratory responses, and a lower energy expenditure. The combination of inhaled CO and exercise produced the greatest effect on mitochondrial morphology, increasing ADP-stimulated respiration in the presence of pyruvate, and preventing a decline in resting energy expenditure. These data support a therapeutic role for CO and exercise in preserving mitochondrial morphology and respiration during metabolic overload.
Assuntos
Monóxido de Carbono/metabolismo , Dinaminas/genética , Obesidade/genética , Aumento de Peso/genética , Animais , Monóxido de Carbono/farmacologia , Dieta Hiperlipídica , Metabolismo Energético/efeitos dos fármacos , Humanos , Camundongos , Mitocôndrias Musculares/metabolismo , Mitocôndrias Musculares/patologia , Dinâmica Mitocondrial/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Mioblastos/metabolismo , Mioblastos/patologia , Obesidade/metabolismo , Obesidade/patologia , Condicionamento Físico Animal , Ratos , Espécies Reativas de Oxigênio/metabolismo , Sacarose/efeitos adversosRESUMO
Energy homeostasis regulation is essential for the maintenance of life. Neuronal hypothalamic populations are involved in the regulation of energy balance. In order play this role, they require energy: mitochondria, indeed, have a key role in ensuring a constant energy supply to neurons. Mitochondria are cellular organelles that are involved in dynamic processes; their dysfunction has been associated with many diseases, such as obesity and type 2 diabetes, indicating their importance in cellular metabolism and bioenergetics. Food intake excess can induce mitochondrial dysfunction with consequent production of reactive oxygen species (ROS) and oxidative stress. Several studies have shown the involvement of mitochondrial dynamics in the modulation of releasing agouti-related protein (AgRP) and proopiomelanocortin (POMC) neuronal activity, although the mechanisms are still unclear. However, recent studies have shown that changes in mitochondrial metabolism, such as in inflammation, can contribute also to the activation of the microglial system in several diseases, especially degenerative diseases. This review is aimed to summarize the link between mitochondrial dynamics and hypothalamic neurons in the regulation of glucose and energy homeostasis. Furthermore, we focus on the importance of microglia activation in the pathogenesis of many diseases, such as obesity, and on the relationship with mitochondrial dynamics, although this process is still largely unknown.
Assuntos
Proteína Relacionada com Agouti/genética , Metabolismo Energético/genética , Dinâmica Mitocondrial/genética , Neurônios/metabolismo , Pró-Proteína Convertases/genética , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Humanos , Hipotálamo/metabolismo , Microglia/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Obesidade/genética , Obesidade/metabolismo , Obesidade/patologia , Estresse Oxidativo/genéticaRESUMO
Cellular senescence is an endpoint of chemotherapy, and targeted therapies in melanoma and the senescence-associated secretory phenotype (SASP) can affect tumor growth and microenvironment, influencing treatment outcomes. Metabolic interventions can modulate the SASP, and an enhanced mitochondrial energy metabolism supports resistance to therapy in melanoma cells. Herein, we assessed the mitochondrial function of therapy-induced senescent melanoma cells obtained after exposing the cells to temozolomide (TMZ), a methylating chemotherapeutic agent. Senescence induction in melanoma was accompanied by a substantial increase in mitochondrial basal, ATP-linked, and maximum respiration rates and in coupling efficiency, spare respiratory capacity, and respiratory control ratio. Further examinations revealed an increase in mitochondrial mass and length. Alterations in mitochondrial function and morphology were confirmed in isolated senescent cells, obtained by cell-size sorting. An increase in mitofusin 1 and 2 (MFN1 and 2) expression and levels was observed in senescent cells, pointing to alterations in mitochondrial fusion. Silencing mitofusin expression with short hairpin RNA (shRNA) prevented the increase in mitochondrial length, oxygen consumption rate and secretion of interleukin 6 (IL-6), a component of the SASP, in melanoma senescent cells. Our results represent the first in-depth study of mitochondrial function in therapy-induced senescence in melanoma. They indicate that senescence increases mitochondrial mass, length and energy metabolism; and highlight mitochondria as potential pharmacological targets to modulate senescence and the SASP.
Assuntos
Senescência Celular , Metabolismo Energético , GTP Fosfo-Hidrolases/metabolismo , Melanoma Experimental/metabolismo , Mitocôndrias/metabolismo , Proteínas de Neoplasias/metabolismo , Animais , GTP Fosfo-Hidrolases/genética , Inativação Gênica , Interleucina-6/genética , Interleucina-6/metabolismo , Melanoma Experimental/genética , Melanoma Experimental/patologia , Camundongos , Mitocôndrias/genética , Mitocôndrias/patologia , Dinâmica Mitocondrial/efeitos dos fármacos , Dinâmica Mitocondrial/genética , Proteínas de Neoplasias/genética , Temozolomida/farmacologiaRESUMO
Mitochondrial fragmentation and bioenergetic failure manifest in Huntington's disease (HD), a fatal neurodegenerative disease. The factors that couple mitochondrial fusion/fission with bioenergetics and their impacts on neurodegeneration however remain poorly understood. Our proteomic analysis identifies mitochondrial protein ATAD3A as an interactor of mitochondrial fission GTPase, Drp1, in HD. Here we show that, in HD, ATAD3A dimerization due to deacetylation at K135 residue is required for Drp1-mediated mitochondrial fragmentation. Disturbance of ATAD3A steady state impairs mtDNA maintenance by disrupting TFAM/mtDNA binding. Blocking Drp1/ATAD3A interaction with a peptide, DA1, abolishes ATAD3A oligomerization, suppresses mitochondrial fragmentation and mtDNA lesion, and reduces bioenergetic deficits and cell death in HD mouse- and patient-derived cells. DA1 treatment reduces behavioral and neuropathological phenotypes in HD transgenic mice. Our findings demonstrate that ATAD3A plays a key role in neurodegeneration by linking Drp1-induced mitochondrial fragmentation to defective mtDNA maintenance, suggesting that DA1 might be useful for developing HD therapeutics.
Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Metabolismo Energético/genética , Doença de Huntington/genética , Proteínas de Membrana/genética , Dinâmica Mitocondrial/genética , Proteínas Mitocondriais/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Animais , Morte Celular , Linhagem Celular , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/metabolismo , Dinaminas/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Proteínas de Grupo de Alta Mobilidade/metabolismo , Humanos , Doença de Huntington/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Mitocondriais/metabolismo , Mutação , Neurônios/metabolismo , Proteômica , Fatores de Transcrição/metabolismoRESUMO
The aim of this study is to investigate whether copper (Cu) could induce testicular poisoning and influence the mitochondrial dynamics, apoptosis, and autophagy in chickens. For this purpose, thirty-six 1-day-old male Hy-line chickens were divided into control group (C group) and test group (Cu group). The chickens were exposed to 0 (C group) or 300 mg/kg (Cu group) of copper sulfate (CuSO4) for 30, 60, and 90 days. CuSO4 was added into the basal diet to make supplements. Testis tissues were subjected to observation of ultrastructure and detection of testis-related indexes. The results indicated that in the test group, the levels of the pro-apoptotic genes were up-regulated and the levels of the anti-apoptotic genes were down-regulated; the levels of mitochondrial fission-related genes markedly increased, and the levels of mitochondrial fusion-related genes were highly decreased; autophagy-related gene (autophagy-associated gene 4B (ATG4B), dynein, microtubule-associated protein 1 light chain 3 beta (LC3-II), ATG5, and beclin-1) levels were increased, while mammalian target of rapamycin (mTOR) and LC3-I levels were declined. The results of transmission electron microscopy (TEM) demonstrated that Cu induced mitochondrial fragmentation, which induced autophagy and apoptosis in chicken testes. In conclusion, CuSO4 exposure can influence the mitochondrial dynamics balance and lead to mitochondria-initiated intrinsic pathway of apoptosis and autophagy, which triggers the testicular poisoning in chickens. What is more, there is a correlation among mitochondrial dynamics, apoptosis, and autophagy.
Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Galinhas/crescimento & desenvolvimento , Cobre/toxicidade , Dinâmica Mitocondrial/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Apoptose/genética , Proteínas Reguladoras de Apoptose/genética , Autofagia/genética , Galinhas/genética , Expressão Gênica/efeitos dos fármacos , Masculino , Dinâmica Mitocondrial/genética , Proteínas Mitocondriais/genética , Testículo/ultraestruturaRESUMO
Currently, electrical stimulation (ES) is used to induce changes in various tissues and cellular processes, but its effects on mitochondrial dynamics and mechanisms are unknown. The aim of this study was to compare the effects of monophasic and biphasic, anodal, and cathodal ES on apoptosis, proliferation, and mitochondrial dynamics in neuroblastoma SH-SY5Y cells. Cells were cultured and treated with ES. Alamar blue assay was performed to measure cell proliferation. The proteins expression of apoptotic-related proteins Bcl-2 associated X (Bax), B cell lymphoma 2 (Bcl-2), optic-atrophy-1 (OPA1), mitofusin2 (Mfn2), phosphorylated dynamin-related protein 1 at serine 616 (p-DRP1), and total dynamin-related protein 1 (Total-DRP1) were also determined. The results showed that monophasic anodal and biphasic anodal/cathodal (Bi Anod) ES for 1 hr at 125 pulses per minute (2.0 Hz) produced the most significant increase in cell proliferation. In addition, monophasic anodal and Bi Anod ES treated cells displayed a significant increase in the levels of anti-apoptotic protein Bcl-2, whereas the Bax levels were not changed. Moreover, the levels of Mfn2 were increased in the cells treated by Bi Anod, and OPA1 was increased by monophasic anodal and Bi Anod ES, indicating increased mitochondrial fusion in these ES-treated cells. However, the levels of mitochondrial fission indicated by DRP1 remained unchanged compared with non-stimulated cells. These findings were confirmed through visualization of mitochondria using Mitotracker Deep Red, demonstrating that monophasic anodal and Bi Anod ES could induce pro-survival effects in SH-SY5Y cells through increasing cell proliferation and mitochondrial fusion. Future research is needed to validate these findings for the clinical application of monophasic anodal and Bi Anod ES.
Assuntos
Apoptose/efeitos da radiação , Proliferação de Células/efeitos da radiação , Estimulação Elétrica , Dinâmica Mitocondrial/efeitos da radiação , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Dinaminas , GTP Fosfo-Hidrolases/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Associadas aos Microtúbulos/genética , Mitocôndrias/genética , Mitocôndrias/efeitos da radiação , Dinâmica Mitocondrial/genética , Proteínas Mitocondriais/genética , Fosforilação/genética , Fosforilação/efeitos da radiação , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína X Associada a bcl-2/genéticaRESUMO
Restrictive anorexia nervosa is associated with reduced eating and severe body weight loss leading to a cachectic state. Hypothalamus plays a major role in the regulation of food intake and energy homeostasis. In the present study, alterations of hypothalamic proteome and particularly of proteins involved in energy and mitochondrial metabolism have been observed in female activity-based anorexia (ABA) mice that exhibited a reduced food intake and a severe weight loss. In the hypothalamus, mitochondrial dynamic was also modified during ABA with an increase of fission without modification of fusion. In addition, increased dynamin-1, and LC3II/LC3I ratio signed an activation of autophagy while protein synthesis was increased. In conclusion, proteomic analysis revealed an adaptive hypothalamic protein response in ABA female mice with both altered mitochondrial response and activated autophagy.
Assuntos
Anorexia Nervosa/genética , Dinamina I/genética , Hipotálamo/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Dinâmica Mitocondrial/genética , Proteoma/genética , Aconitato Hidratase/genética , Aconitato Hidratase/metabolismo , Animais , Anorexia , Anorexia Nervosa/metabolismo , Anorexia Nervosa/fisiopatologia , Autofagia/genética , Modelos Animais de Doenças , Dinamina I/metabolismo , Ingestão de Alimentos/genética , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Hipotálamo/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/metabolismo , Condicionamento Físico Animal , Biossíntese de Proteínas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteoma/metabolismo , Receptores de Enterotoxina/genética , Receptores de Enterotoxina/metabolismo , Transdução de Sinais , Redução de Peso/genéticaRESUMO
Psychological stress, depression and anxiety lead to multiple organ dysfunctions wherein stress-related mucosal disease (SRMD) is common to people experiencing stress and also occur as a side effect in patients admitted to intensive care units; however the underlying molecular aetiology is still obscure. We report that in rat-SRMD model, cold restraint-stress severely damaged gut mitochondrial functions to generate superoxide anion (O2â¢-), depleted ATP and shifted mitochondrial fission-fusion dynamics towards enhanced fission to induce mucosal injury. Activation of mitophagy to clear damaged and fragmented mitochondria was evident from mitochondrial translocation of Parkin and PINK1 along with enhanced mitochondrial proteome ubiquitination, depletion of mitochondrial DNA copy number and TOM 20. However, excess and sustained accumulation of O2â¢--generating defective mitochondria overpowered the mitophagic machinery, ultimately triggering Bax-dependent apoptosis and NF-κB-intervened pro-inflammatory mucosal injury. We further observed that stress-induced enhanced serum corticosterone stimulated mitochondrial recruitment of glucocorticoid receptor (GR), which contributed to gut mitochondrial dysfunctions as documented from reduced ETC complex 1 activity, mitochondrial O2â¢- accumulation, depolarization and hyper-fission. GR-antagonism by RU486 or specific scavenging of mitochondrial O2â¢- by a mitochondrially targeted antioxidant mitoTEMPO ameliorated stress-induced mucosal damage. Gut mitopathology and mucosal injury were also averted when the perception of mental stress was blocked by pre-treatment with a sedative or antipsychotic. Altogether, we suggest the role of mitochondrial GR-O2â¢--fission cohort in brain-mitochondria cross-talk during acute mental stress and advocate the utilization of this pathway as a potential target to prevent mitochondrial unrest and gastropathy bypassing central nervous system.
Assuntos
Trifosfato de Adenosina/metabolismo , Mucosa Gástrica/metabolismo , Imobilização/psicologia , Mitocôndrias/metabolismo , Estresse Psicológico/metabolismo , Animais , Antipsicóticos/farmacologia , Temperatura Baixa , Corticosterona/sangue , Complexo I de Transporte de Elétrons/genética , Complexo I de Transporte de Elétrons/metabolismo , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Regulação da Expressão Gênica , Imobilização/métodos , Inflamação , Proteínas de Membrana Transportadoras , Mifepristona/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Dinâmica Mitocondrial/efeitos dos fármacos , Dinâmica Mitocondrial/genética , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Mitofagia/efeitos dos fármacos , Mitofagia/genética , NF-kappa B/genética , NF-kappa B/metabolismo , Compostos Organofosforados/farmacologia , Estresse Oxidativo , Piperidinas/farmacologia , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Ratos Sprague-Dawley , Receptores de Superfície Celular , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores de Glucocorticoides/antagonistas & inibidores , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Estômago , Estresse Psicológico/genética , Estresse Psicológico/patologia , Superóxidos/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Osteosarcoma is an aggressive bone cancer arising from primitive transformed cells of mesenchymal origin to form malignant osteoid. Phyllanthus urinaria [Formula: see text]P. urinaria[Formula: see text] is a widely used folk medicine in cancer treatment, however the mechanism of P. urinaria inhibited human osteosarcoma is unclear. The present study was aimed at investigating the antitumoral effects of an aqueous P. urinaria on human osteosarcoma in vivo and the related underlying mechanisms, mainly focusing on mitochondrial dynamic dysfunction. Our results showed that oral administration of P. urinaria to mice led to significant inhibition of tumor development without substantial changes to body weight or major organs. Histological examinations with H&E, Giemsa, and Masson trichrome stains confirmed inhibition of tumor growth by the P. urinaria treatment. Immunohistochemical staining of proliferation markers antigen KI-67 (Ki67) and proliferating cell nuclear antigen (PCNA), as well as a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay demonstrated a decrease of tumor proliferation and an increase of apoptosis, which was associated with the modulation of B-cell lymphoma 2 (Bcl-2) family activating the caspase cascade in the P. urinaria-treated mice. The neovascularization marker cluster of differentiation 31 (CD31) was inhibited in P. urinaria-treated xenografts, implicating the potential anti-angiogenic effect of P. urinaria. P. urinaria treatment resulted in a significant decrease in the mitochondrial fusion proteins, including mitofusin 1/2 (Mfn1/2) and optic atrophy type 1 (Opa1), as well as an increase in the fission protein dynamin-related protein 1 (Drp1). The results of this study suggest mitochondrial dysfunction is associated with dynamic change that is involved in the apoptosis and anti-angiogenesis elicited by P. urinaria.
Assuntos
Antineoplásicos Fitogênicos , Apoptose/efeitos dos fármacos , Apoptose/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Dinâmica Mitocondrial/efeitos dos fármacos , Dinâmica Mitocondrial/genética , Osteonecrose/genética , Osteonecrose/patologia , Osteossarcoma/genética , Osteossarcoma/patologia , Phyllanthus/química , Fitoterapia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Animais , DNA Nucleotidilexotransferase/metabolismo , Xenoenxertos , Humanos , Antígeno Ki-67/metabolismo , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Extratos Vegetais/isolamento & purificação , Antígeno Nuclear de Célula em Proliferação/metabolismoRESUMO
The purpose of our study was to investigate the protective effects of a natural product-'curcumin'- in Alzheimer's disease (AD)-like neurons. Although much research has been done in AD, very little has been reported on the effects of curcumin on mitochondrial biogenesis, dynamics, function and synaptic activities. Therefore, the present study investigated the protective effects against amyloid ß (Aß) induced mitochondrial and synaptic toxicities. Using human neuroblastoma (SHSY5Y) cells, curcumin and Aß, we studied the protective effects of curcumin against Aß. Further, we also studied preventive (curcumin+Aß) and intervention (Aß+curcumin) effects of curcumin against Aß in SHSY5Y cells. Using real time RT-PCR, immunoblotting and immunofluorescence analysis, we measured mRNA and protein levels of mitochondrial dynamics, mitochondrial biogenesis and synaptic genes. We also assessed mitochondrial function by measuring hydrogen peroxide, lipid peroxidation, cytochrome oxidase activity and mitochondrial ATP. Cell viability was studied using the MTT assay. Aß was found to impair mitochondrial dynamics, reduce mitochondrial biogenesis and decrease synaptic activity and mitochondrial function. In contrast, curcumin enhanced mitochondrial fusion activity and reduced fission machinery, and increased biogenesis and synaptic proteins. Mitochondrial function and cell viability were elevated in curcumin treated cells. Interestingly, curcumin pre- and post-treated cells incubated with Aß showed reduced mitochondrial dysfunction, and maintained cell viability and mitochondrial dynamics, mitochondrial biogenesis and synaptic activity. Further, the protective effects of curcumin were stronger in pretreated SHSY5Y cells than in post-treated cells, indicating that curcumin works better in prevention than treatment in AD-like neurons. Our findings suggest that curcumin is a promising drug molecule to treat AD patients.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/toxicidade , Produtos Biológicos/uso terapêutico , Curcumina/uso terapêutico , Mitocôndrias/patologia , Fármacos Neuroprotetores/uso terapêutico , Sinapses/patologia , Doença de Alzheimer/patologia , Produtos Biológicos/farmacologia , Linhagem Celular Tumoral , Curcumina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos , Dinâmica Mitocondrial/genética , Fármacos Neuroprotetores/farmacologia , Biogênese de Organelas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sinapses/efeitos dos fármacos , Sinapses/genética , Sinapses/metabolismoRESUMO
Mitochondria are bioenergetic hotspots, producing the bulk of ATP by the oxidative phosphorylation process. Mitochondria are also structurally dynamic and undergo coordinated fusion and fission to maintain their function. Recent studies of the mitochondrial fusion machinery have provided new evidence in detailing their role in mitochondrial metabolism. Remarkably, mitofusin 2, in addition to its role in fusion, is important for maintaining coenzyme Q levels and may be an integral player in the mevalonate synthesis pathway. Here, we review the bioenergetic roles of mitochondrial dynamics and emphasize the importance of the in vitro growth conditions when evaluating mitochondrial respiration. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016,' edited by Prof. Paolo Bernardi.