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1.
Nature ; 583(7817): 603-608, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32641832

RESUMEN

Astrocytes take up glucose from the bloodstream to provide energy to the brain, thereby allowing neuronal activity and behavioural responses1-5. By contrast, astrocytes are under neuronal control through specific neurotransmitter receptors5-7. However, whether the activation of astroglial receptors can directly regulate cellular glucose metabolism to eventually modulate behavioural responses is unclear. Here we show that activation of mouse astroglial type-1 cannabinoid receptors associated with mitochondrial membranes (mtCB1) hampers the metabolism of glucose and the production of lactate in the brain, resulting in altered neuronal functions and, in turn, impaired behavioural responses in social interaction assays. Specifically, activation of astroglial mtCB1 receptors reduces the phosphorylation of the mitochondrial complex I subunit NDUFS4, which decreases the stability and activity of complex I. This leads to a reduction in the generation of reactive oxygen species by astrocytes and affects the glycolytic production of lactate through the hypoxia-inducible factor 1 pathway, eventually resulting in neuronal redox stress and impairment of behavioural responses in social interaction assays. Genetic and pharmacological correction of each of these effects abolishes the effect of cannabinoid treatment on the observed behaviour. These findings suggest that mtCB1 receptor signalling can directly regulate astroglial glucose metabolism to fine-tune neuronal activity and behaviour in mice.


Asunto(s)
Astrocitos/metabolismo , Metabolismo Energético , Glucosa/metabolismo , Mitocondrias/metabolismo , Receptor Cannabinoide CB1/metabolismo , Animales , Astrocitos/citología , Astrocitos/efectos de los fármacos , Agonistas de Receptores de Cannabinoides/farmacología , Células Cultivadas , Dronabinol/farmacología , Complejo I de Transporte de Electrón/química , Complejo I de Transporte de Electrón/metabolismo , Metabolismo Energético/efectos de los fármacos , Glucólisis/efectos de los fármacos , Humanos , Factor 1 Inducible por Hipoxia/metabolismo , Ácido Láctico/metabolismo , Masculino , Ratones , Mitocondrias/efectos de los fármacos , Membranas Mitocondriales/metabolismo , Oxidación-Reducción , Fosforilación , Especies Reactivas de Oxígeno/metabolismo , Receptor Cannabinoide CB1/agonistas , Conducta Social
2.
FASEB J ; 37(11): e23222, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37781970

RESUMEN

The mechanisms that underpin aging are still elusive. In this study, we suggest that the ability of mitochondria to oxidize different substrates, which is known as metabolic flexibility, is involved in this process. To verify our hypothesis, we used honey bees (Apis mellifera carnica) at different ages, to assess mitochondrial oxygen consumption and enzymatic activities of key enzymes of the energetic metabolism as well as ATP5A1 content (subunit of ATP synthase) and adenylic energy charge (AEC). We also measured mRNA abundance of genes involved in mitochondrial functions and the antioxidant system. Our results demonstrated that mitochondrial respiration increased with age and favored respiration through complexes I and II of the electron transport system (ETS) while glycerol-3-phosphate (G3P) oxidation was relatively decreased. In addition, glycolytic, tricarboxylic acid cycle and ETS enzymatic activities increased, which was associated with higher ATP5A1 content and AEC. Furthermore, we detected an early decrease in the mRNA abundance of subunits of NADH ubiquinone oxidoreductase subunit B2 (NDUFB2, complex I), mitochondrial cytochrome b (CYTB, complex III) of the ETS as well as superoxide dismutase 1 and a later decrease for vitellogenin, catalase and mitochondrial cytochrome c oxidase subunit 1 (COX1, complex IV). Thus, our study suggests that the energetic metabolism is optimized with aging in honey bees, mainly through quantitative and qualitative mitochondrial changes, rather than showing signs of senescence. Moreover, aging modulated metabolic flexibility, which might reflect an underpinning mechanism that explains lifespan disparities between the different castes of worker bees.


Asunto(s)
Envejecimiento , Mitocondrias , Abejas , Animales , Antioxidantes , Consumo de Oxígeno , ARN Mensajero
3.
Cell Mol Life Sci ; 79(6): 327, 2022 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-35637383

RESUMEN

The architecture of mitochondria adapts to physiological contexts: while mitochondrial fragmentation is usually associated to quality control and cell death, mitochondrial elongation often enhances cell survival during stress. Understanding how these events are regulated is important to elucidate how mitochondrial dynamics control cell fate. Here, we show that the tyrosine kinase Src regulates mitochondrial morphology. Deletion of Src increased mitochondrial size and reduced cellular respiration independently of mitochondrial mass, mitochondrial membrane potential or ATP levels. Re-expression of Src targeted to the mitochondrial matrix, but not of Src targeted to the plasma membrane, rescued mitochondrial morphology in a kinase activity-dependent manner. These findings highlight a novel function for Src in the control of mitochondrial dynamics.


Asunto(s)
Mitocondrias , Familia-src Quinasas , Respiración de la Célula , Potencial de la Membrana Mitocondrial , Mitocondrias/metabolismo , Fosforilación , Familia-src Quinasas/genética , Familia-src Quinasas/metabolismo
4.
Nature ; 539(7630): 555-559, 2016 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-27828947

RESUMEN

Cellular activity in the brain depends on the high energetic support provided by mitochondria, the cell organelles which use energy sources to generate ATP. Acute cannabinoid intoxication induces amnesia in humans and animals, and the activation of type-1 cannabinoid receptors present at brain mitochondria membranes (mtCB1) can directly alter mitochondrial energetic activity. Although the pathological impact of chronic mitochondrial dysfunctions in the brain is well established, the involvement of acute modulation of mitochondrial activity in high brain functions, including learning and memory, is unknown. Here, we show that acute cannabinoid-induced memory impairment in mice requires activation of hippocampal mtCB1 receptors. Genetic exclusion of CB1 receptors from hippocampal mitochondria prevents cannabinoid-induced reduction of mitochondrial mobility, synaptic transmission and memory formation. mtCB1 receptors signal through intra-mitochondrial Gαi protein activation and consequent inhibition of soluble-adenylyl cyclase (sAC). The resulting inhibition of protein kinase A (PKA)-dependent phosphorylation of specific subunits of the mitochondrial electron transport system eventually leads to decreased cellular respiration. Hippocampal inhibition of sAC activity or manipulation of intra-mitochondrial PKA signalling or phosphorylation of the Complex I subunit NDUFS2 inhibit bioenergetic and amnesic effects of cannabinoids. Thus, the G protein-coupled mtCB1 receptors regulate memory processes via modulation of mitochondrial energy metabolism. By directly linking mitochondrial activity to memory formation, these data reveal that bioenergetic processes are primary acute regulators of cognitive functions.


Asunto(s)
Cannabinoides/efectos adversos , Trastornos de la Memoria/inducido químicamente , Memoria/efectos de los fármacos , Memoria/fisiología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Adenilil Ciclasas/metabolismo , Animales , Cannabinoides/metabolismo , Respiración de la Célula/efectos de los fármacos , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Transporte de Electrón/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Femenino , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/patología , Masculino , Trastornos de la Memoria/enzimología , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/patología , Ratones , Membranas Mitocondriales/efectos de los fármacos , Membranas Mitocondriales/enzimología , Membranas Mitocondriales/metabolismo , NADH Deshidrogenasa/metabolismo , Fosforilación Oxidativa/efectos de los fármacos , Receptor Cannabinoide CB1/deficiencia , Receptor Cannabinoide CB1/genética , Receptor Cannabinoide CB1/metabolismo , Transducción de Señal/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos
5.
Cell Physiol Biochem ; 54(4): 517-537, 2020 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-32428391

RESUMEN

BACKGROUND/AIMS: Src kinase family members, including c-Src, are involved in numerous signaling pathways and have been observed inside different cellular compartments. Notably, c-Src modulates carbohydrate and fatty acid metabolism and is involved in the metabolic rewiring of cancer cells. This kinase is found within mitochondria where it targets different proteins to impact on the organelle functions and overall metabolism. Surprisingly, no global metabolic characterization of Src has been performed although c-Src knock-out mice have been available for 30 years. Considering that c-Src is sensitive to various metabolites, c-Src might represent a crucial player in metabolic adjustments induced by nutrient stress. The aim of this work was to characterize the impact of c-Src on mitochondrial activity and overall metabolism using multi-omic characterization. METHODS: Src+/+ and Src-/- mice were fed ad libitum or fasted during 24h and were then analyzed using multi-omics. RESULTS: We observed that deletion of c-Src is linked to lower phosphorylation of Y412-NDUFA8, inhibition of oxygen consumption and accumulation of metabolites involved in glycolysis, TCA cycle and amino acid metabolism in mice fed ad libitum. Finally, metabolomics and (phosphotyrosine) proteomics are differently impacted by Src according to nutrient availability. CONCLUSION: The findings presented here highlight that c-Src reduces mitochondrial metabolism and impacts the metabolic adjustment induced by nutrient stress.


Asunto(s)
Mitocondrias/metabolismo , Fosfotirosina/metabolismo , Proteoma/metabolismo , Familia-src Quinasas/metabolismo , Animales , Encéfalo/metabolismo , Cromatografía Liquida , Ciclo del Ácido Cítrico/genética , Cromatografía de Gases y Espectrometría de Masas , Glucólisis/genética , Riñón/metabolismo , Ratones , Ratones Noqueados , Mitocondrias/enzimología , Mitocondrias/genética , Mitocondrias Hepáticas/genética , Mitocondrias Hepáticas/metabolismo , Nutrientes/metabolismo , Fosforilación , Fosfotirosina/genética , Proteómica , Espectrometría de Masas en Tándem , Familia-src Quinasas/genética
6.
Int J Mol Sci ; 21(21)2020 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-33167377

RESUMEN

Mitochondria are fully integrated in cell signaling. Reversible phosphorylation is involved in adjusting mitochondrial physiology to the cellular needs. Protein kinase A (PKA) phosphorylates several substrates present at the external surface of mitochondria to maintain cellular homeostasis. However, few targets of PKA located inside the organelle are known. The aim of this work was to characterize the impact and the interactome of PKA located inside mitochondria. Our results show that the overexpression of intramitochondrial PKA decreases cellular respiration and increases superoxide levels. Using proximity-dependent biotinylation, followed by LC-MS/MS analysis and in silico phospho-site prediction, we identified 21 mitochondrial proteins potentially targeted by PKA. We confirmed the interaction of PKA with TIM44 using coimmunoprecipitation and observed that TIM44-S80 is a key residue for the interaction between the protein and the kinase. These findings provide insights into the interactome of intramitochondrial PKA and suggest new potential mechanisms in the regulation of mitochondrial functions.


Asunto(s)
Biotinilación/métodos , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas Mitocondriales/metabolismo , Mapeo de Interacción de Proteínas/métodos , Coloración y Etiquetado/métodos , Respiración de la Célula/fisiología , Reactivos de Enlaces Cruzados/química , Proteínas Quinasas Dependientes de AMP Cíclico/química , Células HEK293 , Células HeLa , Humanos , Inmunoprecipitación/métodos , Microscopía Fluorescente , Mitocondrias/química , Mitocondrias/metabolismo , Proteínas Mitocondriales/química , Unión Proteica , Procesamiento Proteico-Postraduccional , Transducción de Señal
7.
Bioessays ; 39(12)2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29058339

RESUMEN

CB1 receptors are functionally present within brain mitochondria (mtCB1), although they are usually considered specifically targeted to plasma membrane. Acute activation of mtCB1 alters mitochondrial ATP generation, synaptic transmission, and memory performance. However, the detailed mechanism linking disrupted mitochondrial metabolism and synaptic transmission is still uncharacterized. CB1 receptors are among the most abundant G protein-coupled receptors in the brain and impact on several processes, including fear coping, anxiety, stress, learning, and memory. Mitochondria perform several key physiological processes for neuronal homeostasis, including production of ATP and reactive oxygen species, calcium buffering, metabolism of neurotransmitters, and apoptosis. It is therefore possible that acute activation of mtCB1 impacts on these different mitochondrial functions to modulate synaptic transmission. In reviewing and integrating across the literature in this area, we describe the possible mechanisms involved in the regulation of brain physiology by mtCB1 receptors.


Asunto(s)
Encéfalo/metabolismo , Mitocondrias/genética , Neuronas/metabolismo , Receptor Cannabinoide CB1/metabolismo , Transmisión Sináptica/fisiología , Adenosina Trifosfato/biosíntesis , Animales , Ansiedad/genética , Ansiedad/metabolismo , Ansiedad/fisiopatología , Encéfalo/citología , Calcio/metabolismo , Miedo/fisiología , Humanos , Memoria/fisiología , Mitocondrias/metabolismo , Plasticidad Neuronal/fisiología , Neuronas/citología , Especies Reactivas de Oxígeno/metabolismo , Receptor Cannabinoide CB1/genética , Estrés Psicológico/genética , Estrés Psicológico/metabolismo , Estrés Psicológico/fisiopatología
8.
Biochim Biophys Acta Mol Cell Res ; 1864(1): 169-176, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28340937

RESUMEN

During starvation, intra-mitochondrial sirtuins, NAD+ sensitive deacylating enzymes that modulate metabolic homeostasis and survival, directly adjust mitochondrial function to nutrient availability; concomitantly, mitochondria elongate to escape autophagic degradation. However, whether sirtuins also impinge on mitochondrial dynamics is still uncharacterized. Here we show that the mitochondrial Sirtuin 5 (Sirt5) is essential for starvation induced mitochondrial elongation. Deletion of Sirt5 in mouse embryonic fibroblasts increased levels of mitochondrial dynamics of 51kDa protein and mitochondrial fission protein 1, leading to mitochondrial accumulation of the pro-fission dynamin related protein 1 and to mitochondrial fragmentation. During starvation, Sirt5 deletion blunted mitochondrial elongation, resulting in increased mitophagy. Our results indicate that starvation induced mitochondrial elongation and evasion from autophagic degradation requires the energy sensor Sirt5.


Asunto(s)
Dinaminas/genética , Fibroblastos/metabolismo , Glucosa/farmacología , Mitocondrias/efectos de los fármacos , Dinámicas Mitocondriales/efectos de los fármacos , Sirtuinas/genética , Animales , Autofagia/efectos de los fármacos , Línea Celular Transformada , Medios de Cultivo/farmacología , Dinaminas/metabolismo , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Eliminación de Gen , Glucosa/deficiencia , Ratones , Mitocondrias/metabolismo , Dinámicas Mitocondriales/genética , Mitofagia/efectos de los fármacos , Factores Protectores , Sirtuinas/deficiencia , Estrés Fisiológico
9.
Biochim Biophys Acta Bioenerg ; 1859(9): 868-877, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29694829

RESUMEN

Mitochondria are key organelles for cellular homeostasis. They generate the most part of ATP that is used by cells through oxidative phosphorylation. They also produce reactive oxygen species, neurotransmitters and other signaling molecules. They are important for calcium homeostasis and apoptosis. Considering the role of this organelle, it is not surprising that most mitochondrial dysfunctions are linked to the development of pathologies. Various mechanisms adjust mitochondrial activity according to physiological needs. The cAMP-PKA signaling emerged in recent years as a direct and powerful mean to regulate mitochondrial functions. Multiple evidence demonstrates that such pathway can be triggered from cytosol or directly within mitochondria. Notably, specific anchor proteins target PKA to mitochondria whereas enzymes necessary for generation and degradation of cAMP are found directly in these organelles. Mitochondrial PKA targets proteins localized in different compartments of mitochondria, and related to various functions. Alterations of mitochondrial cAMP-PKA signaling affect the development of several physiopathological conditions, including neurodegenerative diseases. It is however difficult to discriminate between the effects of cAMP-PKA signaling triggered from cytosol or directly in mitochondria. The specific roles of PKA localized in different mitochondrial compartments are also not completely understood. The aim of this work is to review the role of cAMP-PKA signaling in mitochondrial (patho)physiology.


Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Enfermedades Mitocondriales/fisiopatología , Transducción de Señal , Animales , Humanos
10.
Biochim Biophys Acta ; 1817(5): 718-25, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22321370

RESUMEN

The tyrosine kinase Src is upregulated in several cancer cells. In such cells, there is a metabolic reprogramming elevating aerobic glycolysis that seems partly dependent on Src activation. Src kinase was recently shown to be targeted to mitochondria where it modulates mitochondrial bioenergetics in non-proliferative tissues and cells. The main goal of our study was to determine if increased Src kinase activity could also influence mitochondrial metabolism in cancer cells (143B and DU145 cells). We have shown that 143B and DU145 cells produce most of the ATP through glycolysis but also that the inhibition of OXPHOS led to a significant decrease in proliferation which was not due to a decrease in the total ATP levels. These results indicate that a more important role for mitochondria in cancer cells could be ensuring mitochondrial functions other than ATP production. This study is the first to show a putative influence of intramitochondrial Src kinase on oxidative phosphorylation in cancer cells. Indeed, we have shown that Src kinase inhibition led to a decrease in mitochondrial respiration via a specific decrease in complex I activities (NADH-ubiquinone oxidoreductase). This decrease is associated with a lower phosphorylation of the complex I subunit NDUFB10. These results suggest that the preservation of complex I function by mitochondrial Src kinase could be important in the development of the overall phenotype of cancer.


Asunto(s)
Complejo I de Transporte de Electrón/metabolismo , NADH Deshidrogenasa/metabolismo , Familia-src Quinasas/metabolismo , Adenosina Trifosfato/metabolismo , Línea Celular Tumoral , Respiración de la Célula/efectos de los fármacos , Cromatografía Liquida , Metabolismo Energético/efectos de los fármacos , Humanos , Espectrometría de Masas , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/enzimología , Fosforilación/efectos de los fármacos , Fosfotirosina/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Transporte de Proteínas/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Familia-src Quinasas/antagonistas & inhibidores
11.
Biomolecules ; 13(4)2023 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-37189442

RESUMEN

Mitochondria are the prime source of cellular energy, and are also responsible for important processes such as oxidative stress, apoptosis and Ca2+ homeostasis. Depression is a psychiatric disease characterized by alteration in the metabolism, neurotransmission and neuroplasticity. In this manuscript, we summarize the recent evidence linking mitochondrial dysfunction to the pathophysiology of depression. Impaired expression of mitochondria-related genes, damage to mitochondrial membrane proteins and lipids, disruption of the electron transport chain, higher oxidative stress, neuroinflammation and apoptosis are all observed in preclinical models of depression and most of these parameters can be altered in the brain of patients with depression. A deeper knowledge of the depression pathophysiology and the identification of phenotypes and biomarkers with respect to mitochondrial dysfunction are needed to help early diagnosis and the development of new treatment strategies for this devastating disorder.


Asunto(s)
Depresión , Trastornos Mentales , Humanos , Mitocondrias/metabolismo , ADN Mitocondrial/metabolismo , Trastornos Mentales/metabolismo , Estrés Oxidativo
12.
Cell Death Dis ; 14(11): 729, 2023 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-37949858

RESUMEN

Accumulation of α-synuclein aggregates in the substantia nigra pars compacta is central in the pathophysiology of Parkinson's disease, leading to the degeneration of dopaminergic neurons and the manifestation of motor symptoms. Although several PD models mimic the pathological accumulation of α-synuclein after overexpression, they do not allow for controlling and monitoring its aggregation. We recently generated a new optogenetic tool by which we can spatiotemporally control the aggregation of α-synuclein using a light-induced protein aggregation system. Using this innovative tool, we aimed to characterize the impact of α-synuclein clustering on mitochondria, whose activity is crucial to maintain neuronal survival. We observed that aggregates of α-synuclein transiently and dynamically interact with mitochondria, leading to mitochondrial depolarization, lower ATP production, mitochondrial fragmentation and degradation via cardiolipin externalization-dependent mitophagy. Aggregation of α-synuclein also leads to lower mitochondrial content in human dopaminergic neurons and in mouse midbrain. Interestingly, overexpression of α-synuclein alone did not induce mitochondrial degradation. This work is among the first to clearly discriminate between the impact of α-synuclein overexpression and aggregation on mitochondria. This study thus represents a new framework to characterize the role of mitochondria in PD.


Asunto(s)
Enfermedad de Parkinson , alfa-Sinucleína , Animales , Humanos , Ratones , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Cardiolipinas/metabolismo , Neuronas Dopaminérgicas/metabolismo , Mitocondrias/metabolismo , Mitofagia , Enfermedad de Parkinson/metabolismo , Sustancia Negra/metabolismo
13.
Nat Med ; 29(6): 1487-1499, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37291212

RESUMEN

Cannabis use disorder (CUD) is widespread, and there is no pharmacotherapy to facilitate its treatment. AEF0117, the first of a new pharmacological class, is a signaling-specific inhibitor of the cannabinoid receptor 1 (CB1-SSi). AEF0117 selectively inhibits a subset of intracellular effects resulting from Δ9-tetrahydrocannabinol (THC) binding without modifying behavior per se. In mice and non-human primates, AEF0117 decreased cannabinoid self-administration and THC-related behavioral impairment without producing significant adverse effects. In single-ascending-dose (0.2 mg, 0.6 mg, 2 mg and 6 mg; n = 40) and multiple-ascending-dose (0.6 mg, 2 mg and 6 mg; n = 24) phase 1 trials, healthy volunteers were randomized to ascending-dose cohorts (n = 8 per cohort; 6:2 AEF0117 to placebo randomization). In both studies, AEF0117 was safe and well tolerated (primary outcome measurements). In a double-blind, placebo-controlled, crossover phase 2a trial, volunteers with CUD were randomized to two ascending-dose cohorts (0.06 mg, n = 14; 1 mg, n = 15). AEF0117 significantly reduced cannabis' positive subjective effects (primary outcome measurement, assessed by visual analog scales) by 19% (0.06 mg) and 38% (1 mg) compared to placebo (P < 0.04). AEF0117 (1 mg) also reduced cannabis self-administration (P < 0.05). In volunteers with CUD, AEF0117 was well tolerated and did not precipitate cannabis withdrawal. These data suggest that AEF0117 is a safe and potentially efficacious treatment for CUD.ClinicalTrials.gov identifiers: NCT03325595 , NCT03443895 and NCT03717272 .


Asunto(s)
Cannabis , Alucinógenos , Abuso de Marihuana , Síndrome de Abstinencia a Sustancias , Animales , Ratones , Método Doble Ciego , Dronabinol/efectos adversos , Alucinógenos/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Síndrome de Abstinencia a Sustancias/tratamiento farmacológico
14.
Hum Mutat ; 33(4): 681-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22241583

RESUMEN

Some cases of maternally inherited isolated deafness are caused by mtDNA mutations, frequently following an exposure to aminoglycosides. Two mitochondrial genes have been clearly described as being affected by mutations responsible for this pathology: the ribosomal RNA 12S gene and the transfer RNA serine (UCN) gene. A previous study identified several candidate novel mtDNA mutations, localized in a variety of mitochondrial genes, found in patients with no previous treatment with aminoglycosides. Five of these candidate mutations are characterized in the present study. These mutations are localized in subunit ND1 of complex I of the respiratory chain (m.3388C>A [p.MT-ND1:Leu28Met]), the tRNA for Isoleucine (m.4295A>G), subunit COII of complex IV (m.8078G>A [p.MT-CO2:Val165Ile]), the tRNA of Serine 2 (AGU/C) (m.12236G>A), and Cytochrome B, subunit of complex III (m.15077G>A [p.MT-CYB:Glu111Lys]). Cybrid cell lines have been constructed for each of the studied mtDNA mutations and functional studies have been performed to assess the possible consequences of these mutations on mitochondrial bioenergetics. This study shows that a variety of mitochondrial genes, including protein-coding genes, can be responsible for nonsyndromic deafness, and that exposure to aminoglycosides is not required to develop the disease, giving new insights on the molecular bases of this pathology.


Asunto(s)
ADN Mitocondrial , Pérdida Auditiva/genética , Mutación , NADH Deshidrogenasa/genética , ARN de Transferencia de Serina/genética , Aminoglicósidos/efectos adversos , Línea Celular , Respiración de la Célula/genética , Citocromos b/genética , Citocromos b/metabolismo , Femenino , Pérdida Auditiva/inducido químicamente , Humanos , Masculino , Mitocondrias/genética , Mitocondrias/metabolismo , Madres , NADH Deshidrogenasa/química , NADH Deshidrogenasa/metabolismo , Linaje , Fosforilación , Polimorfismo de Longitud del Fragmento de Restricción , Conformación Proteica , ARN de Transferencia de Isoleucina/genética , ARN de Transferencia de Serina/metabolismo
15.
Biochim Biophys Acta ; 1807(6): 707-18, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21692240

RESUMEN

The AMP-activated protein kinase agonist AICAR mimics a low intracellular energy state and inhibits the proliferation of cancer cells by different mechanisms, which may depend on the bioenergetic signature of these cells. AICAR can also stimulate mitochondrial biogenesis in myoblasts, neurons and HeLa cells. Yet, whether the reactivation of oxidative phosphorylation biogenesis by AICAR contributes to the growth arrest of cancer cells remains undetermined. To investigate this possibility, we looked at the impact of 24- and 48-hour treatments with 750 µM AICAR on human cancer cell lines (HeLa, DU145, and HEPG2), non-cancer cells (EM64, FM14, and HLF), embryonic cells (MRC5) and Rho(0) cells. We determined the bioenergetic profile of these cells and assessed the effect of AICAR on oxidative phosphorylation biogeneis, cell viability and cell proliferation, ROS generation, mitochondrial membrane potential and apoptosis induction. We also followed possible changes in metabolic regulators such as Akt and Hif1-α stabilization which might participate to the anti-proliferative effect of AICAR. Our results demonstrated a strong and cancer-specific anti-growth effect of AICAR that may be explained by three different modes according to cell type: the first mode included stimulation of the mitochondrial apoptotic pathway however with compensatory activation of Akt and upregulation of oxidative phosphorylation. In the second mode of action of AICAR Akt phosphorylation was reduced. In the third mode of action, apoptosis was activated by different pathways. The sensitivity to AICAR was higher in cells with a low steady-state ATP content and a high proliferation rate.


Asunto(s)
Aminoimidazol Carboxamida/análogos & derivados , Proliferación Celular/efectos de los fármacos , Neoplasias/patología , Proteína Oncogénica v-akt/metabolismo , Fosforilación Oxidativa/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Ribonucleótidos/farmacología , Aminoimidazol Carboxamida/farmacología , Evaluación Preclínica de Medicamentos , Activación Enzimática/efectos de los fármacos , Células HeLa , Células Hep G2 , Humanos , Hipoglucemiantes/farmacología , Especificidad de Órganos/efectos de los fármacos , Factores de Tiempo , Células Tumorales Cultivadas
16.
Cell Mol Life Sci ; 68(15): 2603-13, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21063895

RESUMEN

Given the presence of Src and PTP1B within rat brain mitochondria, we have investigated whether PTP1B regulates Src activity in mitochondria as in the cytosol. Results showed that Src was stimulated by in vitro addition of ATP to mitochondria, and this stimulation was reversed by a membrane-permeable allosteric inhibitor of PTP1B and by a potent selective Src inhibitor. They also indicated a direct action of PTP1B on phosphorylated tyrosine 527 residue of Src, thus implicating a role for PTP1B in the modulation of Src activity in mitochondria. Putative Src and PTP1B substrates were identified by liquid chromatography tandem mass spectrometry and two-dimensional blue native/SDS-PAGE. Both inhibitors inhibited ADP-stimulated respirations concurrently with Src activation and complex IV activation by ATP, while having no effect or increasing the activity of the other complexes. Our analysis emphasizes the regulatory function of Src and its modulation by PTP1B on oxidative phosphorylation in mitochondria.


Asunto(s)
Encéfalo/metabolismo , Mitocondrias/metabolismo , Fosforilación Oxidativa , Proteína Tirosina Fosfatasa no Receptora Tipo 1/fisiología , Familia-src Quinasas/metabolismo , Animales , Electroforesis en Gel de Poliacrilamida , Activación Enzimática , Masculino , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Ratas , Ratas Wistar , Tirosina/metabolismo
17.
Mitochondrion ; 57: 257-269, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33412331

RESUMEN

C-Src kinase is localized in several subcellular compartments, including mitochondria where it is involved in the regulation of organelle functions and overall metabolism. Surprisingly, the characterization of the intramitochondrial Src interactome has never been fully determined. Using in vitro proximity-dependent biotin identification (BioID) coupled to mass spectrometry, we identified 51 candidate proteins that may interact directly or indirectly with c-Src within the mitochondrial matrix. Pathway analysis suggests that these proteins are involved in a large array of mitochondrial functions such as protein folding and import, mitochondrial organization and transport, oxidative phosphorylation, tricarboxylic acid cycle and metabolism of amino and fatty acids. Among these proteins, we identified 24 tyrosine phosphorylation sites in 17 mitochondrial proteins (AKAP1, VDAC1, VDAC2, VDAC3, LonP1, Hsp90, SLP2, PHB2, MIC60, UBA1, EF-Tu, LRPPRC, ACO2, OAT, ACAT1, ETFß and ATP5ß) as potential substrates for intramitochondrial Src using in silico prediction of tyrosine phospho-sites. Interaction of c-Src with SLP2 and ATP5ß was confirmed using coimmunoprecipitation. This study suggests that the intramitochondrial Src could target several proteins and regulate different mitochondrial functions.


Asunto(s)
Proteínas Sanguíneas/metabolismo , Proteínas de la Membrana/metabolismo , Mitocondrias/metabolismo , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Proteínas Proto-Oncogénicas pp60(c-src)/metabolismo , Cromatografía Liquida , Regulación de la Expresión Génica , Células HEK293 , Células HeLa , Humanos , Fosforilación , Prohibitinas , Mapeo de Interacción de Proteínas , Proteínas Proto-Oncogénicas pp60(c-src)/genética , Espectrometría de Masas en Tándem
18.
Mol Immunol ; 135: 1-11, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33838400

RESUMEN

Neutrophils play a key role in the innate immunity with their ability to generate and release inflammatory mediators that promote the inflammatory response and consequently restore the hemostasis. As active participants in several steps of the normal inflammatory response, neutrophils are also involved in chronic inflammatory diseases such as asthma, atherosclerosis, and arthritis. Given their dual role in the modulation of inflammation, regulating the inflammatory response of neutrophils has been suggested as an important therapeutic approach by numerous researchers. The neutrophils have a relatively short lifespan, which can be problematic for some in vitro experiments. To address this issue, researchers have used the human monomyelocyte cell line PLB-985 as an in vitro model for exploratory experiments addressing neutrophil-related physiological functions. PLB-985 cells can be differentiated into a neutrophil-like phenotype upon exposure to several agonists, including dimethyl sulfoxide (DMSO). Whether this differentiation of PLB-985 affects important features related to the neutrophil's normal functions (i.e., mitochondrial activity, eicosanoid production) remains elusive, and characterizing these changes will be the focal point of this study. Our results indicate that the differentiation affected the proliferation of PLB-985 cells, without inducing apoptosis. A significant decrease in mitochondrial respiration was observed in differentiated PLB-985 cells. However, the overall mitochondria content was not affected. Immunoblotting with mitochondrial antibodies revealed a strong modulation of the succinate dehydrogenase A, superoxide dismutase 2, ubiquinol-cytochrome c reductase core protein 2 and ATP synthase subunit α in differentiated PLB-985 cells. Finally, eicosanoids (leukotriene B4, 12-hydroxyheptadecatrienoic and 15-hydroxyeicosatetraenoic acids) production was significantly increased in differentiated cells. In summary, our data demonstrate that the differentiation process of PLB-985 cells does not impact their viability despite a reduced respiratory state of the cells. This process is also accompanied by modulation of the inflammatory state of the cell. Of importance, our data suggest that PLB-985 cells could be suitable in vitro candidates to study mitochondrial-related dysfunctions in inflammatory diseases.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Dimetilsulfóxido/farmacología , Eicosanoides/metabolismo , Mitocondrias/metabolismo , Neutrófilos/citología , Apoptosis/efectos de los fármacos , Diferenciación Celular/inmunología , Línea Celular , Proliferación Celular/efectos de los fármacos , Complejo II de Transporte de Electrones/metabolismo , Complejo III de Transporte de Electrones/metabolismo , Trampas Extracelulares/efectos de los fármacos , Depuradores de Radicales Libres/farmacología , Humanos , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Neutrófilos/inmunología , Fagocitosis/efectos de los fármacos , Superóxido Dismutasa/metabolismo
19.
Front Cell Dev Biol ; 9: 714710, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34434934

RESUMEN

Peroxisome biogenesis disorders (PBDs) are a group of metabolic developmental diseases caused by mutations in one or more genes encoding peroxisomal proteins. Zellweger syndrome spectrum (PBD-ZSS) results from metabolic dysfunction caused by damaged or non-functional peroxisomes and manifests as a multi-organ syndrome with significant morbidity and mortality for which there is no current drug therapy. Mild PBD-ZSS patients can exhibit a more progressive disease course and could benefit from the identification of drugs to improve the quality of life and extend the lifespan of affected individuals. Our study used a high-throughput screen of FDA-approved compounds to identify compounds that improve peroxisome function and biogenesis in human fibroblast cells carrying the mild PBD-ZSS variant, PEX1G843D. Our screen identified the nitrogen oxide donor, S-nitrosoglutathione (GSNO), as a potential therapeutic for this mild form of PBD-ZSS. Further biochemical characterization showed that GSNO enhances both peroxisome number and function in PEX1G843D mutant fibroblasts and leads to increased survival and longer lifespan in an in vivo humanized Drosophila model carrying the PEX1G843D mutation. GSNO is therefore a strong candidate to be translated to clinical trials as a potential therapeutic for mild PBD-ZSS.

20.
Neuron ; 109(9): 1513-1526.e11, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33770505

RESUMEN

Recent advances in neuroscience have positioned brain circuits as key units in controlling behavior, implying that their positive or negative modulation necessarily leads to specific behavioral outcomes. However, emerging evidence suggests that the activation or inhibition of specific brain circuits can actually produce multimodal behavioral outcomes. This study shows that activation of a receptor at different subcellular locations in the same neuronal circuit can determine distinct behaviors. Pharmacological activation of type 1 cannabinoid (CB1) receptors in the striatonigral circuit elicits both antinociception and catalepsy in mice. The decrease in nociception depends on the activation of plasma membrane-residing CB1 receptors (pmCB1), leading to the inhibition of cytosolic PKA activity and substance P release. By contrast, mitochondrial-associated CB1 receptors (mtCB1) located at the same terminals mediate cannabinoid-induced catalepsy through the decrease in intra-mitochondrial PKA-dependent cellular respiration and synaptic transmission. Thus, subcellular-specific CB1 receptor signaling within striatonigral circuits determines multimodal control of behavior.


Asunto(s)
Encéfalo/metabolismo , Receptor Cannabinoide CB1/metabolismo , Transducción de Señal/fisiología , Transmisión Sináptica/fisiología , Animales , Encéfalo/efectos de los fármacos , Agonistas de Receptores de Cannabinoides/farmacología , Antagonistas de Receptores de Cannabinoides/farmacología , Catalepsia/inducido químicamente , Membrana Celular/metabolismo , Células HEK293 , Células HeLa , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Nocicepción/efectos de los fármacos , Nocicepción/fisiología , Transducción de Señal/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos
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