RÉSUMÉ
Despite its robust proteopathic nature, the spatiotemporal signature of disrupted protein modules in sporadic Alzheimer's disease (AD) brains remains poorly understood. This considered oxidative stress contributes to AD progression and early intervention with coenzyme Q10 or its reduced form, ubiquinol, delays the progression of the disease. Using MALDI-MSI and functional bioinformatic analysis, we have developed a protocol to express how deregulated protein modules arise from hippocampus and cortex in the AD mice model 3xTG-AD in an age-dependent manner. This strategy allowed us to identify which modules can be efficiently restored to a non-pathological condition by early intervention with ubiquinol. Indeed, an early deregulation of proteostasis-related protein modules, oxidative stress and metabolism has been observed in the hippocampus of 6-month mice (early AD) and the mirrored in cortical regions of 12-month mice (middle/late AD). This observation has been validated by IHC using mouse and human brain sections, suggesting that these protein modules are also affected in humans. The emergence of disrupted protein modules with AD signature can be prevented by early dietary intervention with ubiquinol in the 3xTG-AD mice model.
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PURPOSE: Most monotherapies available against glioblastoma multiforme (GBM) target individual hallmarks of this aggressive brain tumor with minimal success. In this article, we propose a therapeutic strategy using coenzyme Q10 (CoQ10) as a pleiotropic factor that crosses the blood-brain barrier and accumulates in cell membranes acting as an antioxidant, and in mitochondrial membranes as a regulator of cell bioenergetics and gene expression. METHODS: Xenografts of U251 cells in nu/nu mice were used to assay tumor growth, hypoxia, angiogenesis, and inflammation. An orthotopic model was used to explore microglial infiltration, tumor growth, and invasion into the brain parenchyma. Cell proliferation, migration, invasion, proteome remodeling, and secretome were assayed in vitro. Conditioned media were used to assay angiogenesis, monocyte chemoattraction, and differentiation into macrophages in vitro. RESULTS: CoQ10 treatment decreased tumor volume in xenografts and orthotopic models, although its effect on tumor cell proliferation was not direct. Tumors from mice treated with CoQ10 were less hypoxic and vascularized, having less infiltration from inflammatory cells. Treatment-induced downregulation of HIF-1α and NF-kB led to a complete remodeling of the tumor cells proteome and secretome, impacting angiogenesis, monocyte infiltration, and their differentiation into macrophages. Besides, tumor cell migration and invasion were drastically restricted by mechanisms involving modulation of the actin cytoskeleton and downregulation of matrix metalloproteases (MMPs). CONCLUSIONS: CoQ10 has a pleiotropic effect on GBM growth, targeting several hallmarks simultaneously. Thus, its integration into current treatments of this fatal disease should be considered.
Sujet(s)
Tumeurs du cerveau , Glioblastome , Humains , Souris , Animaux , Glioblastome/anatomopathologie , Ubiquinones/pharmacologie , Ubiquinones/usage thérapeutique , Protéome , Antioxydants , Tumeurs du cerveau/anatomopathologie , Hypoxie , Inflammation , Lignée cellulaire tumoraleRÉSUMÉ
Although the basis of Alzheimer's disease (AD) etiology remains unknown, oxidative stress (OS) has been recognized as a prodromal factor associated to its progression. OS refers to an imbalance between oxidant and antioxidant systems, which usually consist in an overproduction of reactive oxygen species (ROS) and reactive nitrogen species (RNS) which overwhelms the intrinsic antioxidant defenses. Due to this increased production of ROS and RNS, several biological functions such as glucose metabolism or synaptic activity are impaired. In AD, growing evidence links the ROS-mediated damages with molecular targets including mitochondrial dynamics and function, protein quality control system, and autophagic pathways, affecting the proteostasis balance. In this scenario, OS should be considered as not only a major feature in the pathophysiology of AD but also a potential target to combat the progression of the disease. In this review, we will discuss the role of OS in mitochondrial dysfunction, protein quality control systems, and autophagy associated to AD and suggest innovative therapeutic strategies based on a better understanding of the role of OS and proteostasis.
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OBJECTIVES: To investigate how the modulation of the oxidative balance affects cytotoxic therapies in glioblastoma, in vitro. MATERIAL AND METHODS: Human glioblastoma U251 and T98 cells and normal astrocytes C8D1A were loaded with coenzyme Q10 (CoQ). Mitochondrial superoxide ion (O2-) and H2O2 were measured by fluorescence microscopy. OXPHOS performance was assessed in U251 cells with an oxytherm Clark-type electrode. Radio- and chemotherapy cytotoxicity was assessed by immunostaining of γH2AX (24â¯h), annexin V and nuclei morphology, at short (72â¯h) and long (15â¯d) time. Hif-1α, SOD1, SOD2 and NQO1 were determined by immunolabeling. Catalase activity was measured by classic enzymatic assay. Glutathione levels and total antioxidant capacity were quantified using commercial kits. RESULTS: CoQ did not affect oxygen consumption but reduced the level of O2- and H2O2 while shifted to a pro-oxidant cell status mainly due to a decrease in catalase activity and SOD2 level. Hif-1α was dampened, echoed by a decrease lactate and several key metabolites involved in glutathione synthesis. CoQ-treated cells were twofold more sensitive than control to radiation-induced DNA damage and apoptosis in short and long-term clonogenic assays, potentiating TMZ-induced cytotoxicity, without affecting non-transformed astrocytes. CONCLUSIONS: CoQ acts as sensitizer for cytotoxic therapies, disarming GBM cells, but not normal astrocytes, against further pro-oxidant injuries, being potentially useful in clinical practice for this fatal pathology.
Sujet(s)
Tumeurs du cerveau/radiothérapie , Dacarbazine/analogues et dérivés , Glioblastome/radiothérapie , Ubiquinones/analogues et dérivés , Antioxydants/usage thérapeutique , Apoptose/physiologie , Tumeurs du cerveau/traitement médicamenteux , Tumeurs du cerveau/enzymologie , Altération de l'ADN , Dacarbazine/pharmacologie , Glioblastome/traitement médicamenteux , Glioblastome/enzymologie , Humains , Peroxyde d'hydrogène/métabolisme , Mitochondries/métabolisme , Stress oxydatif , Consommation d'oxygène/physiologie , Radiotolérance , Espèces réactives de l'oxygène/métabolisme , Témozolomide , Cellules cancéreuses en culture , Ubiquinones/métabolisme , Ubiquinones/pharmacologieSujet(s)
Évolution clonale/génétique , Leucémie aigüe myéloïde/diagnostic , Leucémie aigüe myéloïde/génétique , Mutation , Protéines nucléaires/génétique , Phénotype , Marqueurs biologiques tumoraux , Analyse de mutations d'ADN , Études d'associations génétiques , Étude d'association pangénomique , Humains , Leucémie aigüe myéloïde/mortalité , Nucléophosmine , Pronostic , RécidiveRÉSUMÉ
INTRODUCTION: The advent of anti-tumor necrosis factor alpha (anti-TNFα) drugs has considerably improved medical management in rheumatoid arthritis (RA) patients, although it has been reported to be ineffective in a fraction of them. MicroRNAs (miRNAs) are small, non-coding RNAs that act as fine-tuning regulators of gene expression. Targeting miRNAs by gain or loss of function approaches have brought therapeutic effects in various disease models. The aim of this study was to investigate serum miRNA levels as predictive biomarkers of response to anti-TNFα therapy in RA patients. METHODS: In total, 95 RA patients undergoing anti-TNFα/disease-modifying antirheumatic drugs (anti-TNFα/DMARDs) combined treatments were enrolled. Serum samples were obtained at 0 and 6 months and therapeutic efficacy was assessed. miRNAs were isolated from the serum of 10 patients before and after anti-TNFα/DMARDs combination therapy, cDNA transcribed and pooled, and human serum miRNA polymerase chain reaction (PCR) arrays were performed. Subsequently, selected miRNAs were analyzed in a validation cohort consisting of 85 RA patients. Correlation studies with clinical and serological variables were also performed. RESULTS: Ninety percent of RA patients responded to anti-TNFα/DMARDs combination therapy according to European League Against Rheumatism (EULAR) criteria. Array analysis showed that 91% of miRNAS were overexpressed and 9% downregulated after therapy. Functional classification revealed a preponderance of target mRNAs involved in reduction of cells maturation--especially on chondrocytes--as well as in immune and inflammatory response, cardiovascular disease, connective tissue and musculoskeletal system. Six out of ten miRNAs selected for validation were found significantly upregulated by anti-TNFα/DMARDs combination therapy (miR-16-5p, miR-23-3p, miR125b-5p, miR-126-3p, miRN-146a-5p, miR-223-3p). Only responder patients showed an increase in those miRNAs after therapy, and paralleled the reduction of TNFα, interleukin (IL)-6, IL-17, rheumatoid factor (RF), and C-reactive protein (CRP). Correlation studies demonstrated associations between validated miRNAs and clinical and inflammatory parameters. Further, we identified a specific plasma miRNA signature (miR-23 and miR-223) that may serve both as predictor and biomarker of response to anti-TNFα/DMARDs combination therapy. CONCLUSIONS: miRNA levels in the serum of RA patients before and after anti-TNFα/DMARDs combination therapy are potential novel biomarkers for predicting and monitoring therapy outcome.
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Antirhumatismaux/usage thérapeutique , Polyarthrite rhumatoïde/sang , microARN/sang , Facteur de nécrose tumorale alpha/antagonistes et inhibiteurs , Adulte , Sujet âgé , Polyarthrite rhumatoïde/traitement médicamenteux , Marqueurs biologiques/sang , Femelle , Humains , Mâle , Adulte d'âge moyen , Jeune adulteRÉSUMÉ
Neuropathological symptoms of Alzheimer's disease appear in advances stages, once neuronal damage arises. Nevertheless, recent studies demonstrate that in early asymptomatic stages, ß-amyloid peptide damages the cerebral microvasculature through mechanisms that involve an increase in reactive oxygen species and calcium, which induces necrosis and apoptosis of endothelial cells, leading to cerebrovascular dysfunction. The goal of our work is to study the potential preventive effect of the lipophilic antioxidant coenzyme Q (CoQ) against ß-amyloid-induced damage on human endothelial cells. We analyzed the protective effect of CoQ against Aß-induced injury in human umbilical vein endothelial cells (HUVECs) using fluorescence and confocal microscopy, biochemical techniques and RMN-based metabolomics. Our results show that CoQ pretreatment of HUVECs delayed Aß incorporation into the plasma membrane and mitochondria. Moreover, CoQ reduced the influx of extracellular Ca(2+), and Ca(2+) release from mitochondria due to opening the mitochondrial transition pore after ß-amyloid administration, in addition to decreasing O2(.-) and H2O2 levels. Pretreatment with CoQ also prevented ß-amyloid-induced HUVECs necrosis and apoptosis, restored their ability to proliferate, migrate and form tube-like structures in vitro, which is mirrored by a restoration of the cell metabolic profile to control levels. CoQ protected endothelial cells from Aß-induced injury at physiological concentrations in human plasma after oral CoQ supplementation and thus could be a promising molecule to protect endothelial cells against amyloid angiopathy.
Sujet(s)
Peptides bêta-amyloïdes/métabolisme , Endothélium vasculaire/effets des médicaments et des substances chimiques , Stress oxydatif , Ubiquinones/analogues et dérivés , Endothélium vasculaire/cytologie , Endothélium vasculaire/métabolisme , Cellules endothéliales de la veine ombilicale humaine , Humains , Ubiquinones/pharmacologieRÉSUMÉ
Increased oxidative stress seems to be a key factor underlying natural processes of aging, but also to occur prior to neuropathological hallmarks of neurodegenerative diseases. The present work studied the temporal variation of three key antioxidant enzymes in cortex and hippocampus during the development of behavioral and cognitive symptoms in 3xTg-AD mice, and as compared to age-matched controls. At 2 months of age, when no intraneuronal Aß immunoreactivity has been reported, increased neophobia shown as a delayed and reduced rearing, evidenced the onset of BPSD-like symptoms at premorbid stages of disease. In these animals, NQO1 was found increased in both the hippocampus (800%) and cortex (400%) and progressively diminished at older ages. SOD1 was increased in the hippocampus at 4 months of age, when neuronal Aß accumulation has been established. These hippocampal increases of antioxidants before the prodromal emergence of cognitive symptoms support their role as defense mechanisms. SIRT1 levels showed opposite age-dependent changes in cortex (increase) and hippocampus (decrease) relative to controls. Prodromal cognitive deficits emerged at 6 months of age, concomitantly to cortical overexpression of SIRT1 but down-regulation of NQO1 and SIRT1 in the hippocampus, suggesting inadequate antioxidative protection to prevent or delay the subjacent neuronal damage. The present data further support the link between oxidative status and the anxious profile. Their crosstalk may underline AD-pathological mechanisms that may lead to deranged physiology and selective neuronal degeneration. It also points out increased neophobia and high expression of NQO1 among the first indicators of disease in the 3xTg-AD mice.
Sujet(s)
Vieillissement/psychologie , Maladie d'Alzheimer/métabolisme , Maladie d'Alzheimer/psychologie , Cognition , NADPH dehydrogenase (quinone)/métabolisme , Sirtuine-1/métabolisme , Vieillissement/métabolisme , Précurseur de la protéine bêta-amyloïde/métabolisme , Animaux , Cortex cérébral/métabolisme , Modèles animaux de maladie humaine , Hippocampe/métabolisme , Mâle , Souris , Souris de lignée C57BL , Souris transgéniques , Superoxide dismutase/métabolisme , Superoxide dismutase-1RÉSUMÉ
Obesity prevalence is reaching pandemic proportions becoming a major public health threat for many industrialized nations. It is especially worrying as it causes a higher risk of premature death due to associated diseases such as type 2 diabetes, cardiovascular disease, and some cancers. Current evidence shows biological and genetic differences between adipose tissues depending on its anatomical location. Particularly, upper body/visceral fat distribution in obesity is closely linked to metabolic complications. In this report, we characterize for the first time the secretome of rat adipose tissue explants from different anatomical localizations and its differential analysis. Visceral, subcutaneous, and gonadal fat specific secretomes and differentially secreted proteins among the three fat depots were analyzed by 2-DE and MS. Reference maps for location-specific adipose tissue secretomes are shown and the 45 most significant differences are listed. Identified proteins include classical adipokines and novel secreted proteins. Interestingly, our results show that the type of proteins and their role in different biological processes diverge significantly when comparing the set of proteins identified from visceral, subcutaneous and gonadal fat explants. This study emphasizes and supports the differential role of adipose tissue in accordance to its anatomical localization.