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1.
Cell ; 186(6): 1212-1229.e21, 2023 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-36827974

RESUMO

Mitochondrial activity differs markedly between organs, but it is not known how and when this arises. Here we show that cell lineage-specific expression profiles involving essential mitochondrial genes emerge at an early stage in mouse development, including tissue-specific isoforms present before organ formation. However, the nuclear transcriptional signatures were not independent of organelle function. Genetically disrupting intra-mitochondrial protein synthesis with two different mtDNA mutations induced cell lineage-specific compensatory responses, including molecular pathways not previously implicated in organellar maintenance. We saw downregulation of genes whose expression is known to exacerbate the effects of exogenous mitochondrial toxins, indicating a transcriptional adaptation to mitochondrial dysfunction during embryonic development. The compensatory pathways were both tissue and mutation specific and under the control of transcription factors which promote organelle resilience. These are likely to contribute to the tissue specificity which characterizes human mitochondrial diseases and are potential targets for organ-directed treatments.


Assuntos
Mitocôndrias , Organogênese , Animais , Feminino , Humanos , Camundongos , Gravidez , Linhagem da Célula , DNA Mitocondrial/genética , Mitocôndrias/metabolismo , Doenças Mitocondriais , Especificidade de Órgãos , Desenvolvimento Embrionário , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo
2.
Cell ; 182(3): 641-654.e20, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32615085

RESUMO

Targeting glycolysis has been considered therapeutically intractable owing to its essential housekeeping role. However, the context-dependent requirement for individual glycolytic steps has not been fully explored. We show that CRISPR-mediated targeting of glycolysis in T cells in mice results in global loss of Th17 cells, whereas deficiency of the glycolytic enzyme glucose phosphate isomerase (Gpi1) selectively eliminates inflammatory encephalitogenic and colitogenic Th17 cells, without substantially affecting homeostatic microbiota-specific Th17 cells. In homeostatic Th17 cells, partial blockade of glycolysis upon Gpi1 inactivation was compensated by pentose phosphate pathway flux and increased mitochondrial respiration. In contrast, inflammatory Th17 cells experience a hypoxic microenvironment known to limit mitochondrial respiration, which is incompatible with loss of Gpi1. Our study suggests that inhibiting glycolysis by targeting Gpi1 could be an effective therapeutic strategy with minimum toxicity for Th17-mediated autoimmune diseases, and, more generally, that metabolic redundancies can be exploited for selective targeting of disease processes.


Assuntos
Diferenciação Celular/imunologia , Encefalomielite Autoimune Experimental/imunologia , Glucose-6-Fosfato Isomerase/metabolismo , Glicólise/genética , Fosforilação Oxidativa , Via de Pentose Fosfato/fisiologia , Células Th17/metabolismo , Animais , Hipóxia Celular/genética , Hipóxia Celular/imunologia , Quimera/genética , Cromatografia Gasosa , Cromatografia Líquida , Infecções por Clostridium/imunologia , Citocinas/deficiência , Citocinas/genética , Citocinas/metabolismo , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/metabolismo , Glucose-6-Fosfato Isomerase/genética , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/genética , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/metabolismo , Glicólise/imunologia , Homeostase/genética , Homeostase/imunologia , Inflamação/genética , Inflamação/imunologia , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mucosa/imunologia , Mucosa/metabolismo , Mucosa/microbiologia , Via de Pentose Fosfato/genética , Via de Pentose Fosfato/imunologia , RNA-Seq , Análise de Célula Única , Células Th17/imunologia , Células Th17/patologia
3.
Cell ; 178(2): 473-490.e26, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31230715

RESUMO

We introduce APEX-seq, a method for RNA sequencing based on direct proximity labeling of RNA using the peroxidase enzyme APEX2. APEX-seq in nine distinct subcellular locales produced a nanometer-resolution spatial map of the human transcriptome as a resource, revealing extensive patterns of localization for diverse RNA classes and transcript isoforms. We uncover a radial organization of the nuclear transcriptome, which is gated at the inner surface of the nuclear pore for cytoplasmic export of processed transcripts. We identify two distinct pathways of messenger RNA localization to mitochondria, each associated with specific sets of transcripts for building complementary macromolecular machines within the organelle. APEX-seq should be widely applicable to many systems, enabling comprehensive investigations of the spatial transcriptome.


Assuntos
DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Endonucleases/metabolismo , Enzimas Multifuncionais/metabolismo , RNA/metabolismo , Análise de Sequência de RNA/métodos , Corantes Fluorescentes/química , Células HEK293 , Humanos , Microscopia de Fluorescência , Mitocôndrias/genética , RNA/química , RNA Mensageiro/química , RNA Mensageiro/metabolismo , Transcriptoma
4.
Cell ; 167(2): 471-483.e10, 2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27693358

RESUMO

Mitochondrial ribosomes translate membrane integral core subunits of the oxidative phosphorylation system encoded by mtDNA. These translation products associate with nuclear-encoded, imported proteins to form enzyme complexes that produce ATP. Here, we show that human mitochondrial ribosomes display translational plasticity to cope with the supply of imported nuclear-encoded subunits. Ribosomes expressing mitochondrial-encoded COX1 mRNA selectively engage with cytochrome c oxidase assembly factors in the inner membrane. Assembly defects of the cytochrome c oxidase arrest mitochondrial translation in a ribosome nascent chain complex with a partially membrane-inserted COX1 translation product. This complex represents a primed state of the translation product that can be retrieved for assembly. These findings establish a mammalian translational plasticity pathway in mitochondria that enables adaptation of mitochondrial protein synthesis to the influx of nuclear-encoded subunits.


Assuntos
Ciclo-Oxigenase 1/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/enzimologia , Proteínas Mitocondriais/metabolismo , Transporte Ativo do Núcleo Celular , Linhagem Celular Tumoral , Ciclo-Oxigenase 1/biossíntese , Ciclo-Oxigenase 1/genética , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/biossíntese , Complexo IV da Cadeia de Transporte de Elétrons/genética , Células HEK293 , Humanos , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Proteínas Mitocondriais/biossíntese , Proteínas Mitocondriais/genética , Fosforilação Oxidativa , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Mitocondrial , Ribossomos/metabolismo
5.
Cell ; 167(3): 722-738.e23, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27768893

RESUMO

A functional crosstalk between epigenetic regulators and metabolic control could provide a mechanism to adapt cellular responses to environmental cues. We report that the well-known nuclear MYST family acetyl transferase MOF and a subset of its non-specific lethal complex partners reside in mitochondria. MOF regulates oxidative phosphorylation by controlling expression of respiratory genes from both nuclear and mtDNA in aerobically respiring cells. MOF binds mtDNA, and this binding is dependent on KANSL3. The mitochondrial pool of MOF, but not a catalytically deficient mutant, rescues respiratory and mtDNA transcriptional defects triggered by the absence of MOF. Mof conditional knockout has catastrophic consequences for tissues with high-energy consumption, triggering hypertrophic cardiomyopathy and cardiac failure in murine hearts; cardiomyocytes show severe mitochondrial degeneration and deregulation of mitochondrial nutrient metabolism and oxidative phosphorylation pathways. Thus, MOF is a dual-transcriptional regulator of nuclear and mitochondrial genomes connecting epigenetics and metabolism.


Assuntos
Metabolismo Energético/genética , Epigênese Genética , Histona Acetiltransferases/metabolismo , Mitocôndrias Musculares/enzimologia , Fatores de Transcrição/metabolismo , Transcrição Gênica , Animais , Cardiomiopatia Hipertrófica/genética , Respiração Celular/genética , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Células HeLa , Insuficiência Cardíaca/genética , Histona Acetiltransferases/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Knockout , Mitocôndrias Cardíacas/enzimologia , Mitocôndrias Cardíacas/genética , Mitocôndrias Musculares/genética , Miócitos Cardíacos/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosforilação Oxidativa , Fatores de Transcrição/genética
6.
Immunity ; 54(8): 1698-1714.e5, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34233154

RESUMO

Antigen-specific CD8+ T cells in chronic viral infections and tumors functionally deteriorate, a process known as exhaustion. Exhausted T cells are sustained by precursors of exhausted (Tpex) cells that self-renew while continuously generating exhausted effector (Tex) cells. However, it remains unknown how Tpex cells maintain their functionality. Here, we demonstrate that Tpex cells sustained mitochondrial fitness, including high spare respiratory capacity, while Tex cells deteriorated metabolically over time. Tpex cells showed early suppression of mTOR kinase signaling but retained the ability to activate this pathway in response to antigen receptor signals. Early transient mTOR inhibition improved long-term T cell responses and checkpoint inhibition. Transforming growth factor-ß repressed mTOR signaling in exhausted T cells and was a critical determinant of Tpex cell metabolism and function. Overall, we demonstrate that the preservation of cellular metabolism allows Tpex cells to retain long-term functionality to sustain T cell responses during chronic infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Metabolismo Energético/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mitocôndrias/metabolismo , Transdução de Sinais/imunologia
7.
Immunity ; 49(4): 654-665.e5, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30266340

RESUMO

Recruitment of immune cells with antimicrobial activities is essential to fight local infections but has the potential to trigger immunopathology. Whether the immune system has the ability to sense inflammation intensity and self-adjust accordingly to limit tissue damage remains to be fully established. During local infection with an intracellular pathogen, we have shown that nitric oxide (NO) produced by recruited monocyte-derived cells was essential to limit inflammation and cell recruitment. Mechanistically, we have provided evidence that NO dampened monocyte-derived cell cytokine and chemokine production by inhibiting cellular respiration and reducing cellular ATP:ADP ratio. Such metabolic control operated at the tissue level but only when a sufficient number of NO-producing cells reached the site of infection. Thus, NO production and activity act as a quorum sensing mechanism to help terminate the inflammatory response.


Assuntos
Citocinas/imunologia , Inflamação/imunologia , Monócitos/imunologia , Óxido Nítrico/imunologia , Animais , Células Cultivadas , Citocinas/metabolismo , Células HEK293 , Interações Hospedeiro-Parasita/imunologia , Humanos , Inflamação/metabolismo , Inflamação/parasitologia , Leishmania major/imunologia , Leishmania major/fisiologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/metabolismo , Leishmaniose Cutânea/parasitologia , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/parasitologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Monócitos/metabolismo , Monócitos/parasitologia , Óxido Nítrico/metabolismo , Percepção de Quorum/imunologia
8.
Proc Natl Acad Sci U S A ; 121(28): e2319994121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38959032

RESUMO

Upon encountering allergens, CD4+ T cells differentiate into IL-4-producing Th2 cells in lymph nodes, which later transform into polyfunctional Th2 cells producing IL-5 and IL-13 in inflamed tissues. However, the precise mechanism underlying their polyfunctionality remains elusive. In this study, we elucidate the pivotal role of NRF2 in polyfunctional Th2 cells in murine models of allergic asthma and in human Th2 cells. We found that an increase in reactive oxygen species (ROS) in immune cells infiltrating the lungs is necessary for the development of eosinophilic asthma and polyfunctional Th2 cells in vivo. Deletion of the ROS sensor NRF2 specifically in T cells, but not in dendritic cells, significantly abolished eosinophilia and polyfunctional Th2 cells in the airway. Mechanistically, NRF2 intrinsic to T cells is essential for inducing optimal oxidative phosphorylation and glycolysis capacity, thereby driving Th2 cell polyfunctionality independently of IL-33, partially by inducing PPARγ. Treatment with an NRF2 inhibitor leads to a substantial decrease in polyfunctional Th2 cells and subsequent eosinophilia in mice and a reduction in the production of Th2 cytokines from peripheral blood mononuclear cells in asthmatic patients. These findings highlight the critical role of Nrf2 as a spatial and temporal metabolic hub that is essential for polyfunctional Th2 cells, suggesting potential therapeutic implications for allergic diseases.


Assuntos
Asma , Fator 2 Relacionado a NF-E2 , Espécies Reativas de Oxigênio , Células Th2 , Fator 2 Relacionado a NF-E2/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , Animais , Camundongos , Asma/imunologia , Asma/metabolismo , Humanos , Espécies Reativas de Oxigênio/metabolismo , PPAR gama/metabolismo , Fosforilação Oxidativa , Glicólise , Pulmão/imunologia , Pulmão/metabolismo , Camundongos Knockout , Modelos Animais de Doenças , Feminino , Citocinas/metabolismo , Camundongos Endogâmicos C57BL , Interleucina-33/metabolismo , Eosinofilia/imunologia , Eosinofilia/metabolismo
9.
Hum Mol Genet ; 33(R1): R47-R52, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38779773

RESUMO

The mitochondrial oxidative phosphorylation (OXPHOS) system produces the majority of energy required by cells. Given the mitochondrion's endosymbiotic origin, the OXPHOS machinery is still under dual genetic control where most OXPHOS subunits are encoded by the nuclear DNA and imported into mitochondria, while a small subset is encoded on the mitochondrion's own genome, the mitochondrial DNA (mtDNA). The nuclear and mtDNA encoded subunits must be expressed and assembled in a highly orchestrated fashion to form a functional OXPHOS system and meanwhile prevent the generation of any harmful assembly intermediates. While several mechanisms have evolved in eukaryotes to achieve such a coordinated expression, this review will focus on how the translation of mtDNA encoded OXPHOS subunits is tailored to OXPHOS assembly.


Assuntos
DNA Mitocondrial , Mitocôndrias , Fosforilação Oxidativa , Biossíntese de Proteínas , Mitocôndrias/metabolismo , Mitocôndrias/genética , Humanos , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Animais
10.
EMBO J ; 41(19): e111528, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-35997165

RESUMO

The regulation of cellular energy metabolism is central to most physiological and pathophysiological processes. However, most current methods have limited ability to functionally probe metabolic pathways in individual cells. Here, we describe SPICE-Met (Single-cell Profiling and Imaging of Cell Energy Metabolism), a method for profiling energy metabolism in single cells using flow cytometry or imaging. We generated a transgenic mouse expressing PercevalHR, a fluorescent reporter for cellular ATP:ADP ratio. Modulation of PercevalHR fluorescence with metabolic inhibitors was used to infer the dependence of energy metabolism on oxidative phosphorylation and glycolysis in defined cell populations identified by flow cytometry. We applied SPICE-Met to analyze T-cell memory development during vaccination. Finally, we used SPICE-Met in combination with real-time imaging to dissect the heterogeneity and plasticity of energy metabolism in single macrophages ex vivo and identify three distinct metabolic patterns. Functional probing of energy metabolism with single-cell resolution should greatly facilitate the study of immunometabolism at a steady state, during disease pathogenesis or in response to therapy.


Assuntos
Metabolismo Energético , Fosforilação Oxidativa , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Metabolismo Energético/fisiologia , Glicólise/fisiologia , Camundongos , Camundongos Transgênicos
11.
EMBO J ; 41(23): e110595, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36305367

RESUMO

Mammalian SWI/SNF/BAF chromatin remodeling complexes influence cell lineage determination. While the contribution of these complexes to neural progenitor cell (NPC) proliferation and differentiation has been reported, little is known about the transcriptional profiles that determine neurogenesis or gliogenesis. Here, we report that BCL7A is a modulator of the SWI/SNF/BAF complex that stimulates the genome-wide occupancy of the ATPase subunit BRG1. We demonstrate that BCL7A is dispensable for SWI/SNF/BAF complex integrity, whereas it is essential to regulate Notch/Wnt pathway signaling and mitochondrial bioenergetics in differentiating NPCs. Pharmacological stimulation of Wnt signaling restores mitochondrial respiration and attenuates the defective neurogenic patterns observed in NPCs lacking BCL7A. Consistently, treatment with an enhancer of mitochondrial biogenesis, pioglitazone, partially restores mitochondrial respiration and stimulates neuronal differentiation of BCL7A-deficient NPCs. Using conditional BCL7A knockout mice, we reveal that BCL7A expression in NPCs and postmitotic neurons is required for neuronal plasticity and supports behavioral and cognitive performance. Together, our findings define the specific contribution of BCL7A-containing SWI/SNF/BAF complexes to mitochondria-driven NPC commitment, thereby providing a better understanding of the cell-intrinsic transcriptional processes that connect metabolism, neuronal morphogenesis, and cognitive flexibility.


Assuntos
Diferenciação Celular , Proteínas dos Microfilamentos , Células-Tronco Neurais , Animais , Camundongos , Adenosina Trifosfatases/metabolismo , Montagem e Desmontagem da Cromatina , Metabolismo Energético , Mitocôndrias/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas dos Microfilamentos/metabolismo , Células-Tronco Neurais/citologia
12.
J Biol Chem ; 300(3): 105670, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272226

RESUMO

Schizosaccharomyces pombe Php4 is the regulatory subunit of the CCAAT-binding complexes and plays an important role in the regulation of iron homeostasis and iron-dependent metabolism. Here, we show that Php4 undergoes ubiquitin-dependent degradation in the late logarithmic and stationary phases. The degradation and ubiquitination of Php4 could be attenuated by deletion of hul6, a gene encoding a putative HECT-type E3 ubiquitin ligase. The expression levels of Hul6 and Php4 are oppositely regulated during cell growth. Hul6 interacts with the C-terminal region of Php4. Two lysine residues (K217 and K274) located in the C-terminal region of Php4 are required for its polyubiquitination. Increasing the levels of Php4 by deletion of hul6 or overexpression of php4 decreased expression of Php4 target proteins involved in iron-dependent metabolic pathways such as the tricarboxylic cycle and mitochondrial oxidative phosphorylation, thus causing increased sensitivity to high-iron and reductions in succinate dehydrogenase and mitochondrial complex II activities. Hul6 is located primarily in the mitochondrial outer membrane and most likely targets cytosolic Php4 for ubiquitination and degradation. Taken together, our data suggest that Hul6 regulates iron-dependent metabolism through degradation of Php4 under normal growth conditions. Our results also suggest that Hul6 promotes iron-dependent metabolism to help the cell to adapt to a nutrient-starved growth phase.


Assuntos
Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Citosol/metabolismo , Ferro/metabolismo , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Ubiquitina/metabolismo
13.
EMBO J ; 40(21): e108648, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34542926

RESUMO

So-called ρ0 cells lack mitochondrial DNA and are therefore incapable of aerobic ATP synthesis. How cells adapt to survive ablation of oxidative phosphorylation remains poorly understood. Complexome profiling analysis of ρ0 cells covered 1,002 mitochondrial proteins and revealed changes in abundance and organization of numerous multiprotein complexes including previously not described assemblies. Beyond multiple subassemblies of complexes that would normally contain components encoded by mitochondrial DNA, we observed widespread reorganization of the complexome. This included distinct changes in the expression pattern of adenine nucleotide carrier isoforms, other mitochondrial transporters, and components of the protein import machinery. Remarkably, ablation of mitochondrial DNA hardly affected the complexes organizing cristae junctions indicating that the altered cristae morphology in ρ0 mitochondria predominantly resulted from the loss of complex V dimers required to impose narrow curvatures to the inner membrane. Our data provide a comprehensive resource for in-depth analysis of remodeling of the mitochondrial complexome in response to respiratory deficiency.


Assuntos
Adaptação Fisiológica , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Complexos Multiproteicos/genética , Trifosfato de Adenosina/metabolismo , Linhagem Celular Tumoral , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Expressão Gênica , Humanos , Mitocôndrias/patologia , Membranas Mitocondriais/química , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/deficiência , Complexos Multiproteicos/deficiência , Osteoblastos/metabolismo , Osteoblastos/patologia , Fosforilação Oxidativa
14.
Development ; 149(8)2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-34850846

RESUMO

The role of reactive oxygen species (ROS) in myeloid development is well established. However, its aberrant generation alters hematopoiesis. Thus, a comprehensive understanding of events controlling ROS homeostasis forms the central focus of this study. We show that, in homeostasis, myeloid-like blood progenitor cells of the Drosophila larvae, which reside in a specialized hematopoietic organ termed the lymph gland, use TCA to generate ROS. However, excessive ROS production leads to lymph gland growth retardation. Therefore, to moderate blood progenitor ROS, Drosophila larvae rely on olfaction and its downstream systemic GABA. GABA internalization and its breakdown into succinate by progenitor cells activates pyruvate dehydrogenase kinase (PDK), which controls inhibitory phosphorylation of pyruvate dehydrogenase (PDH). PDH is the rate-limiting enzyme that connects pyruvate to the TCA cycle and to oxidative phosphorylation. Thus, GABA metabolism via PDK activation maintains TCA activity and blood progenitor ROS homeostasis, and supports normal lymph gland growth. Consequently, animals that fail to smell also fail to sustain TCA activity and ROS homeostasis, which leads to lymph gland growth retardation. Overall, this study describes the requirement of animal odor-sensing and GABA in myeloid ROS regulation and hematopoietic growth control.


Assuntos
Hematopoese , Células-Tronco Hematopoéticas/metabolismo , Olfato , Ácido gama-Aminobutírico/metabolismo , Animais , Drosophila melanogaster , Oxirredução , Ácido gama-Aminobutírico/genética
15.
FASEB J ; 38(8): e23615, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38651657

RESUMO

Athletes increasingly engage in repeated sprint training consisting in repeated short all-out efforts interspersed by short recoveries. When performed in hypoxia (RSH), it may lead to greater training effects than in normoxia (RSN); however, the underlying molecular mechanisms remain unclear. This study aimed at elucidating the effects of RSH on skeletal muscle metabolic adaptations as compared to RSN. Sixteen healthy young men performed nine repeated sprint training sessions in either normoxia (FIO2 = 0.209, RSN, n = 7) or normobaric hypoxia (FIO2 = 0.136, RSH, n = 9). Before and after the training period, exercise performance was assessed by using repeated sprint ability (RSA) and Wingate tests. Vastus lateralis muscle biopsies were performed to investigate muscle metabolic adaptations using proteomics combined with western blot analysis. Similar improvements were observed in RSA and Wingate tests in both RSN and RSH groups. At the muscle level, RSN and RSH reduced oxidative phosphorylation protein content but triggered an increase in mitochondrial biogenesis proteins. Proteomics showed an increase in several S100A family proteins in the RSH group, among which S100A13 most strongly. We confirmed a significant increase in S100A13 protein by western blot in RSH, which was associated with increased Akt phosphorylation and its downstream targets regulating protein synthesis. Altogether our data indicate that RSH may activate an S100A/Akt pathway to trigger specific adaptations as compared to RSN.


Assuntos
Adaptação Fisiológica , Hipóxia , Músculo Esquelético , Proteínas S100 , Transdução de Sinais , Humanos , Masculino , Hipóxia/metabolismo , Músculo Esquelético/metabolismo , Adaptação Fisiológica/fisiologia , Transdução de Sinais/fisiologia , Adulto Jovem , Proteínas S100/metabolismo , Adulto , Proteínas Proto-Oncogênicas c-akt/metabolismo , Exercício Físico/fisiologia
16.
Eur Heart J ; 45(4): 287-305, 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-37992083

RESUMO

BACKGROUND AND AIMS: Stanford type A aortic dissection (AD) is a degenerative aortic remodelling disease marked by an exceedingly high mortality without effective pharmacologic therapies. Smooth muscle cells (SMCs) lining tunica media adopt a range of states, and their transformation from contractile to synthetic phenotypes fundamentally triggers AD. However, the underlying pathomechanisms governing this population shift and subsequent AD, particularly at distinct disease temporal stages, remain elusive. METHODS: Ascending aortas from nine patients undergoing ascending aorta replacement and five individuals undergoing heart transplantation were subjected to single-cell RNA sequencing. The pathogenic targets governing the phenotypic switch of SMCs were identified by trajectory inference, functional scoring, single-cell regulatory network inference and clustering, regulon, and interactome analyses and confirmed using human ascending aortas, primary SMCs, and a ß-aminopropionitrile monofumarate-induced AD model. RESULTS: The transcriptional profiles of 93 397 cells revealed a dynamic temporal-specific phenotypic transition and marked elevation of the activator protein-1 (AP-1) complex, actively enabling synthetic SMC expansion. Mechanistically, tumour necrosis factor signalling enhanced AP-1 transcriptional activity by dampening mitochondrial oxidative phosphorylation (OXPHOS). Targeting this axis with the OXPHOS enhancer coenzyme Q10 or AP-1-specific inhibitor T-5224 impedes phenotypic transition and aortic degeneration while improving survival by 42.88% (58.3%-83.3% for coenzyme Q10 treatment), 150.15% (33.3%-83.3% for 2-week T-5224), and 175.38% (33.3%-91.7% for 3-week T-5224) in the ß-aminopropionitrile monofumarate-induced AD model. CONCLUSIONS: This cross-sectional compendium of cellular atlas of human ascending aortas during AD progression provides previously unappreciated insights into a transcriptional programme permitting aortic degeneration, highlighting a translational proof of concept for an anti-remodelling intervention as an attractive strategy to manage temporal-specific AD by modulating the tumour necrosis factor-OXPHOS-AP-1 axis.


Assuntos
Doenças da Aorta , Dissecção Aórtica , Benzofenonas , Isoxazóis , Doenças Vasculares , Humanos , Fator de Transcrição AP-1 , Aminopropionitrilo , Estudos Transversais , Dissecção Aórtica/genética , Doenças da Aorta/patologia , Doenças Vasculares/patologia , Miócitos de Músculo Liso/patologia , Miócitos de Músculo Liso/fisiologia , Fatores de Necrose Tumoral
17.
J Biol Chem ; 299(2): 102865, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36603763

RESUMO

Mitochondrial ribosomes are specialized to translate the 13 membrane proteins encoded in the mitochondrial genome, which shapes the oxidative phosphorylation complexes essential for cellular energy metabolism. Despite the importance of mitochondrial translation (MT) control, it is challenging to identify and quantify the mitochondrial-encoded proteins because of their hydrophobic nature and low abundance. Here, we introduce a mass spectrometry-based proteomic method that combines biochemical isolation of mitochondria with pulse stable isotope labeling by amino acids in cell culture. Our method provides the highest protein identification rate with the shortest measurement time among currently available methods, enabling us to quantify 12 of the 13 mitochondrial-encoded proteins. We applied this method to uncover the global picture of (post-)translational regulation of both mitochondrial- and nuclear-encoded subunits of oxidative phosphorylation complexes. We found that inhibition of MT led to degradation of orphan nuclear-encoded subunits that are considered to form subcomplexes with the mitochondrial-encoded subunits. This method should be readily applicable to study MT programs in many contexts, including oxidative stress and mitochondrial disease.


Assuntos
Mitocôndrias , Biossíntese de Proteínas , Proteômica , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Ribossomos Mitocondriais/metabolismo , Fosforilação Oxidativa , Proteômica/métodos
18.
J Cell Physiol ; 239(6): e31286, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38666481

RESUMO

In our previous study, IRX5 has been revealed a significant role in adipogenesis of hBMSCs. Considering the expansion of adipose tissue in bone marrow in aged and ovariectomy-related osteoporosis, the effect of IRX5 on the osteogenesis of BMSCs still needs to be elucidated. In vivo, models of aging-induced and ovariectomy-induced osteoporotic mice, and in vitro studies of IRX5 gene gain- and loss-of-function in hBMSCs were employed. Histology, immunofluorescence, qRT-PCR, and Western blot analysis were performed to detect the functions of IRX5 in hBMSCs osteogenic differentiation. RNA-seq, transmission electron microscopy, Seahorse mito-stress assay, and Surface Sensing of Translation assay were conducted to explore the effect of mammalian/mechanistic target of rapamycin (mTOR)-mediated ribosomal translation and mitochondrial functions in the regulation of hBMSCs differentiation by IRX5. As a result, elevated IRX5 protein expression levels were observed in the bone marrow of osteoporotic mice compared to normal mice. IRX5 overexpression attenuated osteogenic processes, whereas IRX5 knockdown resulted in enhanced osteogenesis in hBMSCs. RNA-seq and enrichment analysis unveiled that IRX5 overexpression exerted inhibitory effects on ribosomal translation and mitochondrial functions. Furthermore, the application of the mTOR activator, MHY1485, effectively reversed the inhibitory impact of IRX5 on osteogenesis and mitochondrial functions in hBMSCs. In summary, our findings suggest that IRX5 restricts mTOR-mediated ribosomal translation, consequently impairing mitochondrial OxPhos, which in turn results in osteogenic dysfunction of hBMSCs.


Assuntos
Diferenciação Celular , Células-Tronco Mesenquimais , Osteogênese , Biossíntese de Proteínas , Serina-Treonina Quinases TOR , Animais , Humanos , Camundongos , Diferenciação Celular/genética , Células Cultivadas , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mitocôndrias/genética , Osteogênese/genética , Osteoporose/genética , Osteoporose/patologia , Osteoporose/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Masculino , Linhagem Celular , Ribossomos/metabolismo
19.
BMC Genomics ; 25(1): 298, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509489

RESUMO

Mitochondrial genomes play important roles in studying genome evolution, phylogenetic analyses, and species identification. Amphipods (Class Malacostraca, Order Amphipoda) are one of the most ecologically diverse crustacean groups occurring in a diverse array of aquatic and terrestrial environments globally, from freshwater streams and lakes to groundwater aquifers and the deep sea, but we have a limited understanding of how habitat influences the molecular evolution of mitochondrial energy metabolism. Subterranean amphipods likely experience different evolutionary pressures on energy management compared to surface-dwelling taxa that generally encounter higher levels of predation and energy resources and live in more variable environments. In this study, we compared the mitogenomes, including the 13 protein-coding genes involved in the oxidative phosphorylation (OXPHOS) pathway, of surface and subterranean amphipods to uncover potentially different molecular signals of energy metabolism between surface and subterranean environments in this diverse crustacean group. We compared base composition, codon usage, gene order rearrangement, conducted comparative mitogenomic and phylogenomic analyses, and examined evolutionary signals of 35 amphipod mitogenomes representing 13 families, with an emphasis on Crangonyctidae. Mitogenome size, AT content, GC-skew, gene order, uncommon start codons, location of putative control region (CR), length of rrnL and intergenic spacers differed between surface and subterranean amphipods. Among crangonyctid amphipods, the spring-dwelling Crangonyx forbesi exhibited a unique gene order, a long nad5 locus, longer rrnL and rrnS loci, and unconventional start codons. Evidence of directional selection was detected in several protein-encoding genes of the OXPHOS pathway in the mitogenomes of surface amphipods, while a signal of purifying selection was more prominent in subterranean species, which is consistent with the hypothesis that the mitogenome of surface-adapted species has evolved in response to a more energy demanding environment compared to subterranean amphipods. Overall, gene order, locations of non-coding regions, and base-substitution rates points to habitat as an important factor influencing the evolution of amphipod mitogenomes.


Assuntos
Anfípodes , Genoma Mitocondrial , Humanos , Animais , Anfípodes/genética , Filogenia , Códon de Iniciação , Evolução Molecular
20.
Am J Physiol Endocrinol Metab ; 326(2): E124-E133, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38088866

RESUMO

Soy protein has shown remarkable effectiveness in reducing fat mass compared with other protein sources, and exercise has the potential to further enhance this fat loss effect. Previous studies have demonstrated that soy protein intake leads to decreased fatty acid synthesis, which contributes to its fat-loss properties. However, the exact mechanism by which these lipids are consumed remains unclear. To investigate this, we conducted a comprehensive study using C57/BL6 male mice, comparing the effects of soy and casein proteins with and without exercise (Casein-Sed, Casein-Ex, Soy-Sed, and Soy-Ex groups) under high- and low-protein conditions (14% or 40% protein). Our findings revealed that combining soy protein intake with exercise significantly reduced epididymal white adipose tissue (eWAT) weight, particularly in the high-protein diet group. Further analysis revealed that exercise increased the expression of lipid oxidation-regulatory proteins, including mitochondrial oxidative phosphorylation protein (OXPHOS) complexes, in the plantaris muscle regardless of the protein source. Although soy protein intake did not directly affect muscle mitochondrial protein expression, the activity of OXPHOS complex I was additively enhanced by exercise and soy protein under the 40% protein condition. Notably, complex I activity inversely correlated with eWAT weight in the soy protein diet group. These results highlight the potential link between improved complex I activity induced by soy protein and fat mass reduction, which emphasizes the promising benefits of combining soy protein with exercise in promoting fat loss.NEW & NOTEWORTHY The findings revealed that soy protein intake combined with exercise resulted in reduced adipose tissue weight compared with that obtained with casein protein intake. Furthermore, the joint impact of exercise and soy protein consumption resulted in enhanced activity of oxidative phosphorylation protein (OXPHOS) complex I in fast-twitch muscles, which appears to be associated with fat mass reduction. These findings elucidate the potential additive effects of soy protein and exercise on body weight management.


Assuntos
Caseínas , Proteínas de Soja , Masculino , Camundongos , Animais , Proteínas de Soja/farmacologia , Proteínas de Soja/metabolismo , Caseínas/metabolismo , Caseínas/farmacologia , Gordura Intra-Abdominal , Dieta , Músculo Esquelético/metabolismo , Ingestão de Alimentos/fisiologia
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