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1.
Acta Neuropathol ; 148(1): 14, 2024 Aug 01.
Article de Anglais | MEDLINE | ID: mdl-39088078

RÉSUMÉ

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative spinocerebellar ataxia caused by a polyglutamine-coding CAG repeat expansion in the ATXN3 gene. While the CAG length correlates negatively with the age at onset, it accounts for approximately 50% of its variability only. Despite larger efforts in identifying contributing genetic factors, candidate genes with a robust and plausible impact on the molecular pathogenesis of MJD are scarce. Therefore, we analysed missense single nucleotide polymorphism variants in the PRKN gene encoding the Parkinson's disease-associated E3 ubiquitin ligase parkin, which is a well-described interaction partner of the MJD protein ataxin-3, a deubiquitinase. By performing a correlation analysis in the to-date largest MJD cohort of more than 900 individuals, we identified the V380L variant as a relevant factor, decreasing the age at onset by 3 years in homozygous carriers. Functional analysis in an MJD cell model demonstrated that parkin V380L did not modulate soluble or aggregate levels of ataxin-3 but reduced the interaction of the two proteins. Moreover, the presence of parkin V380L interfered with the execution of mitophagy-the autophagic removal of surplus or damaged mitochondria-thereby compromising cell viability. In summary, we identified the V380L variant in parkin as a genetic modifier of MJD, with negative repercussions on its molecular pathogenesis and disease age at onset.


Sujet(s)
Maladie de Machado-Joseph , Mitophagie , Ubiquitin-protein ligases , Maladie de Machado-Joseph/génétique , Maladie de Machado-Joseph/anatomopathologie , Humains , Ubiquitin-protein ligases/génétique , Mitophagie/génétique , Mitophagie/physiologie , Mâle , Femelle , Adulte d'âge moyen , Adulte , Polymorphisme de nucléotide simple , Ataxine-3/génétique , Âge de début , Protéines de répression
2.
Sci Adv ; 10(31): eadp0443, 2024 Aug 02.
Article de Anglais | MEDLINE | ID: mdl-39093974

RÉSUMÉ

Mitochondrial fusion and fission accompany adaptive responses to stress and altered metabolic demands. Inner membrane fusion and cristae morphogenesis depends on optic atrophy 1 (Opa1), which is expressed in different isoforms and is cleaved from a membrane-bound, long to a soluble, short form. Here, we have analyzed the physiological role of Opa1 isoforms and Opa1 processing by generating mouse lines expressing only one cleavable Opa1 isoform or a non-cleavable variant thereof. Our results show that expression of a single cleavable or non-cleavable Opa1 isoform preserves embryonic development and the health of adult mice. Opa1 processing is dispensable under metabolic and thermal stress but prolongs life span and protects against mitochondrial cardiomyopathy in OXPHOS-deficient Cox10-/- mice. Mechanistically, loss of Opa1 processing disturbs the balance between mitochondrial biogenesis and mitophagy, suppressing cardiac hypertrophic growth in Cox10-/- hearts. Our results highlight the critical regulatory role of Opa1 processing, mitochondrial dynamics, and metabolism for cardiac hypertrophy.


Sujet(s)
Cardiomyopathies , dGTPases , Animaux , dGTPases/métabolisme , dGTPases/génétique , Souris , Cardiomyopathies/métabolisme , Cardiomyopathies/génétique , Cardiomyopathies/anatomopathologie , Dynamique mitochondriale , Mitophagie/génétique , Souris knockout , Isoformes de protéines/métabolisme , Isoformes de protéines/génétique , Mitochondries/métabolisme , Modèles animaux de maladie humaine , Développement embryonnaire/génétique
3.
PeerJ ; 12: e17837, 2024.
Article de Anglais | MEDLINE | ID: mdl-39099653

RÉSUMÉ

Hexavalent chromium (Cr(VI)) is a hazardous metallic compound commonly used in industrial processes. The liver, responsible for metabolism and detoxification, is the main target organ of Cr(VI). Toxicity experiments were performed to investigate the impacts of low-dose exposure to Cr(VI) on rat livers. It was revealed that exposure of 0.05 mg/kg potassium dichromate (K2Cr2O7) and 0.25 mg/kg K2Cr2O7 notably increased malondialdehyde (MDA) levels and the expressions of P-AMPK, P-ULK, PINK1, P-Parkin, and LC3II/LC3I, and significantly reduced SOD activity and P-mTOR and P62 expression levels in liver. Electron microscopy showed that CR(VI) exposure significantly increased mitophagy and the destruction of mitochondrial structure. This study simulates the respiratory exposure mode of CR(VI) workers through intratracheal instillation of CR(VI) in rats. It confirms that autophagy in hepatocytes is induced by low concentrations of CR(VI) and suggest that the liver damage caused by CR(VI) may be associated with the AMPK-related PINK/Parkin signaling pathway.


Sujet(s)
Chrome , Foie , Mitophagie , Protein kinases , Transduction du signal , Ubiquitin-protein ligases , Animaux , Chrome/toxicité , Mitophagie/effets des médicaments et des substances chimiques , Protein kinases/métabolisme , Ubiquitin-protein ligases/métabolisme , Transduction du signal/effets des médicaments et des substances chimiques , Foie/effets des médicaments et des substances chimiques , Foie/métabolisme , Foie/anatomopathologie , Rats , Mâle , Dichromate de potassium/toxicité , AMP-Activated Protein Kinases/métabolisme , Rat Sprague-Dawley , Malonaldéhyde/métabolisme
4.
Exp Cell Res ; 441(2): 114182, 2024 Aug 15.
Article de Anglais | MEDLINE | ID: mdl-39094903

RÉSUMÉ

Kawasaki disease (KD) is a systemic vasculitis with an unknown cause that primarily affects children. The objective of this study was to explore the function and underlying mechanism of mitophagy in Mycoplasma pneumoniae (MP)-induced KD. To create MP-induced KD models, Human coronary endothelial cells (HCAECs) and DBA/2 mice were employed and treated with Mp-Lipid-associated membrane proteins (LAMPs). Lactate dehydrogenase (LDH) levels were tested to determine cellular damage or death. The inflammatory cytokines tumor necrosis factor (TNF)--α and interleukin (IL)-6 were measured using the Enzyme-Linked Immunosorbent Assay (ELISA) method. RT-qPCR and Western blotting were used to determine the expression of Intercellular Adhesion Molecule(ICAM)-1, vascular cell adhesion molecule (VCAM)-1, inducible nitric oxide synthase(iNOS), LC3, p62, PINK1(a mitochondrial serine/threonine-protein kinase), and PARKIN(a cytosolic E3-ubiquitin ligase). The adenosine triphosphate (ATP), reactive oxygen species (ROS), and mitochondrial membrane potential(MMP) levels were measured to determine mitochondrial function. Mitophagy was investigated using immunofluorescence and a mitophagy detection test. Autophagosome and mitochondrial morphology were examined using transmission electron microscopy. To identify inflammatory cell infiltration, hematoxylin and eosin staining was utilized. Mp-LAMPs increased the levels of TNF-α, IL-6, ICAM-1, VCAM-1, and iNOS in an HCAEC cell model, along with LDH release. After Mp-LAMPs exposure, there was a rise in LC3 and a reduction in p62. Meanwhile, the expression of PINK1 and Parkin was increased. Cyclosporin A dramatically increased ATP synthesis and MMP in HCAEC cells treated with Mp-LAMPs, while suppressing ROS generation, demonstrating excessive mitophagy-related mitochondrial dysfunction. Additionally, neither body weight nor artery tissue were affected due to PINK1 and Parkin suppression Cyclosporin A in Mp-LAMPs-treated mice. These findings indicated that PINK1/Parkin-mediated mitophagy inhibition may be a therapeutic target for MP-induced KD.


Sujet(s)
Mitophagie , Maladie de Kawasaki , Mycoplasma pneumoniae , Protein kinases , Ubiquitin-protein ligases , Animaux , Maladie de Kawasaki/métabolisme , Maladie de Kawasaki/anatomopathologie , Protein kinases/métabolisme , Humains , Souris , Ubiquitin-protein ligases/métabolisme , Ubiquitin-protein ligases/génétique , Mycoplasma pneumoniae/pathogénicité , Souris de lignée DBA , Cellules endothéliales/métabolisme , Cellules endothéliales/anatomopathologie , Pneumopathie à mycoplasmes/métabolisme , Pneumopathie à mycoplasmes/anatomopathologie , Pneumopathie à mycoplasmes/microbiologie , Mitochondries/métabolisme , Mitochondries/anatomopathologie , Espèces réactives de l'oxygène/métabolisme , Potentiel de membrane mitochondriale
5.
Int J Mol Sci ; 25(15)2024 Jul 30.
Article de Anglais | MEDLINE | ID: mdl-39125927

RÉSUMÉ

During the development of animal organs, various adverse stimuli or toxic environments can induce oxidative stress and delay ovarian development. Paeoniflorin (PF), the main active ingredient of the traditional Chinese herb Paeonia lactiflora Pall., has protective effects on various diseases by preventing oxidative stress. However, the mechanism by which PF attenuates oxidative damage in mouse ovaries remains unclear. We evaluated the protective effects of PF on ovaries in an H2O2-induced mouse oxidative stress model. The H2O2-induced mouse ovarian oxidative stress model was used to explore the protective effect of PF on ovarian development. Histology and follicular development were observed. We then detected related indicators of cell apoptosis, oxidative stress, and autophagy in mouse ovaries. We found that PF inhibited H2O2-induced ovarian cell apoptosis and ferroptosis and promoted granulosa cell proliferation. PF prevented oxidative stress by increasing nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression levels. In addition, the autophagic flux of ovarian cells was activated and was accompanied by increased lysosomal biogenesis. Moreover, PF-mediated autophagy was involved in clearing mitochondria damaged by H2O2. Importantly, PF administration significantly increased the number of primordial follicles, primary follicles, secondary follicles, and antral follicles. PF administration improved ovarian sizes compared with the H2O2 group. The present study suggested that PF administration reversed H2O2-induced ovarian developmental delay and promoted follicle development. PF-activated mitophagy is crucial for preventing oxidative stress and improving mitochondrial quality.


Sujet(s)
Glucosides , Peroxyde d'hydrogène , Mitophagie , Ovaire , Stress oxydatif , Animaux , Femelle , Stress oxydatif/effets des médicaments et des substances chimiques , Glucosides/pharmacologie , Souris , Ovaire/effets des médicaments et des substances chimiques , Ovaire/métabolisme , Mitophagie/effets des médicaments et des substances chimiques , Peroxyde d'hydrogène/métabolisme , Monoterpènes/pharmacologie , Apoptose/effets des médicaments et des substances chimiques , Autophagie/effets des médicaments et des substances chimiques , Heme oxygenase-1/métabolisme , Prolifération cellulaire/effets des médicaments et des substances chimiques , Facteur-2 apparenté à NF-E2/métabolisme , Cellules de la granulosa/effets des médicaments et des substances chimiques , Cellules de la granulosa/métabolisme
6.
FASEB J ; 38(15): e23865, 2024 Aug 15.
Article de Anglais | MEDLINE | ID: mdl-39096136

RÉSUMÉ

A thorough comprehension of age-related variances in orthodontic tooth movement (OTM) and bone remodeling response to mechanical force holds significant implications for enhancing orthodontic treatment. Mitophagy plays a crucial role in bone metabolism and various age-related diseases. However, the impact of mitophagy on the bone remodeling process during OTM remains elusive. Using adolescent (6 weeks old) and adult (12 months old) rats, we established OTM models and observed that orthodontic force increased the expression of the mitophagy proteins PTEN-induced putative kinase 1 (PINK1) and Parkin, as well as the number of tartrate-resistant acid phosphatase-positive osteoclasts and osteocalcin-positive osteoblasts. These biological changes were found to be age-related. In vitro, compression force loading promoted PINK1/Parkin-dependent mitophagy in periodontal ligament stem cells (PDLSCs) derived from adolescents (12-16 years old) and adults (25-35 years old). Furthermore, adult PDLSCs exhibited lower levels of mitophagy, impaired mitochondrial function, and a decreased ratio of RANKL/OPG compared to young PDLSCs after compression. Transfection of siRNA confirmed that inhibition of mitophagy in PDLSC resulted in decreased mitochondrial function and reduced RANKL/OPG ratio. Application of mitophagy inducer Urolithin A enhanced bone remodeling and accelerated OTM in rats, while the mitophagy inhibitor Mdivi-1 had the opposite effect. These findings indicate that force-stimulated PDLSC mitophagy contributes to alveolar bone remodeling during OTM, and age-related impairment of mitophagy negatively impacts the PDLSC response to mechanical stimulus. Our findings enhance the understanding of mitochondrial mechanotransduction and offer new targets to tackle current clinical challenges in orthodontic therapy.


Sujet(s)
Mitochondries , Mitophagie , Ostéoprotégérine , Desmodonte , Ligand de RANK , Mouvement dentaire , Animaux , Mitophagie/physiologie , Rats , Ligand de RANK/métabolisme , Desmodonte/métabolisme , Ostéoprotégérine/métabolisme , Mitochondries/métabolisme , Mâle , Protein kinases/métabolisme , Rat Sprague-Dawley , Adolescent , Ubiquitin-protein ligases/métabolisme , Ubiquitin-protein ligases/génétique , Cellules souches/métabolisme , Remodelage osseux/physiologie , Cellules cultivées
7.
Cell Death Dis ; 15(8): 591, 2024 Aug 15.
Article de Anglais | MEDLINE | ID: mdl-39143050

RÉSUMÉ

Neurons rely heavily on high mitochondrial metabolism to provide sufficient energy for proper development. However, it remains unclear how neurons maintain high oxidative phosphorylation (OXPHOS) during development. Mitophagy plays a pivotal role in maintaining mitochondrial quality and quantity. We herein describe that G protein-coupled receptor 50 (GPR50) is a novel mitophagy receptor, which harbors the LC3-interacting region (LIR) and is required in mitophagy under stress conditions. Although it does not localize in mitochondria under normal culturing conditions, GPR50 is recruited to the depolarized mitochondrial membrane upon mitophagy stress, which marks the mitochondrial portion and recruits the assembling autophagosomes, eventually facilitating the mitochondrial fragments to be engulfed by the autophagosomes. Mutations Δ502-505 and T532A attenuate GPR50-mediated mitophagy by disrupting the binding of GPR50 to LC3 and the mitochondrial recruitment of GPR50. Deficiency of GPR50 causes the accumulation of damaged mitochondria and disrupts OXPHOS, resulting in insufficient ATP production and excessive ROS generation, eventually impairing neuronal development. GPR50-deficient mice exhibit impaired social recognition, which is rescued by prenatal treatment with mitoQ, a mitochondrially antioxidant. The present study identifies GPR50 as a novel mitophagy receptor that is required to maintain mitochondrial OXPHOS in developing neurons.


Sujet(s)
Mitochondries , Mitophagie , Neurones , Récepteurs couplés aux protéines G , Animaux , Récepteurs couplés aux protéines G/métabolisme , Récepteurs couplés aux protéines G/génétique , Neurones/métabolisme , Mitochondries/métabolisme , Souris , Humains , Phosphorylation oxydative , Protéines associées aux microtubules/métabolisme , Protéines associées aux microtubules/génétique , Espèces réactives de l'oxygène/métabolisme , Souris knockout , Neurogenèse
8.
Methods Mol Biol ; 2845: 1-14, 2024.
Article de Anglais | MEDLINE | ID: mdl-39115653

RÉSUMÉ

Selective removal of excess or damaged mitochondria is an evolutionarily conserved process that contributes to mitochondrial quality and quantity control. This catabolic event relies on autophagy, a membrane trafficking system that sequesters cytoplasmic constituents into double membrane-bound autophagosomes and delivers them to lysosomes (vacuoles in yeast) for hydrolytic degradation and is thus termed mitophagy. Dysregulation of mitophagy is associated with various diseases, highlighting its physiological relevance. In budding yeast, the pro-mitophagic single-pass membrane protein Atg32 is upregulated under prolonged respiration or nutrient starvation, anchored on the surface of mitochondria, and activated to recruit the autophagy machinery for the formation of autophagosomes surrounding mitochondria. In this chapter, we provide protocols to assess Atg32-mediated mitophagy using fluorescence microscopy and immunoblotting.


Sujet(s)
Microscopie de fluorescence , Mitochondries , Mitophagie , Saccharomycetales , Microscopie de fluorescence/méthodes , Saccharomycetales/métabolisme , Mitochondries/métabolisme , Immunotransfert/méthodes , Protéines associées à l'autophagie/métabolisme , Protéines associées à l'autophagie/génétique , Protéines de Saccharomyces cerevisiae/métabolisme , Protéines de Saccharomyces cerevisiae/génétique , Saccharomyces cerevisiae/métabolisme , Saccharomyces cerevisiae/génétique , Autophagie/physiologie , Autophagosomes/métabolisme , Récepteurs cytoplasmiques et nucléaires
9.
Methods Mol Biol ; 2845: 39-53, 2024.
Article de Anglais | MEDLINE | ID: mdl-39115656

RÉSUMÉ

Like most eukaryotic cells, mitophagy is essential in plant development and stress response. Several recent studies have revealed proteins that regulate this process, such as Friendly (FMT) and TraB family proteins (TRB), which are plant-unique mitophagy regulators so far. Here, we describe methods for studying mitophagy activity in plants through conventional microscopy and the use of loss-of-function mutants, such as using transgenic mitochondrial marker lines followed by image analysis, chemical inhibitor treatment, and plant phenotype studies. These methods can be used in combination to identify the putative mitophagy regulators and understand their functions in mitochondrial-related activities in plants.


Sujet(s)
Mitochondries , Mitophagie , Mitochondries/métabolisme , Arabidopsis/métabolisme , Arabidopsis/génétique , Plantes/métabolisme , Plantes/génétique , Phénotype , Protéines d'Arabidopsis/métabolisme , Protéines d'Arabidopsis/génétique , Végétaux génétiquement modifiés
10.
Methods Mol Biol ; 2845: 79-93, 2024.
Article de Anglais | MEDLINE | ID: mdl-39115659

RÉSUMÉ

Mitophagy is the degradation of mitochondria via the autophagy-lysosome system, disruption of which has been linked to multiple neurodegenerative diseases. As a flux process involving the identification, tagging, and degradation of subcellular components, the analysis of mitophagy benefits from the microscopy analysis of fluorescent reporters. Studying the pathogenic mechanisms of disease also benefits from analysis in animal models in order to capture the complex interplay of molecular and cell biological phenomena. Here, we describe protocols to analyze mitophagy reporters in Drosophila by light microscopy.


Sujet(s)
Mitochondries , Mitophagie , Animaux , Mitochondries/métabolisme , Gènes rapporteurs , Drosophila/métabolisme , Microscopie de fluorescence/méthodes , Drosophila melanogaster/métabolisme , Lysosomes/métabolisme , Autophagie/physiologie , Protéines de Drosophila/métabolisme , Protéines de Drosophila/génétique
11.
Methods Mol Biol ; 2845: 55-66, 2024.
Article de Anglais | MEDLINE | ID: mdl-39115657

RÉSUMÉ

Preserving mitochondrial homeostasis is vital, particularly for the energetically demanding and metabolically active nerve cells. Mitophagy, the selective autophagic removal of mitochondria, stands out as a prominent mechanism for efficient mitochondrial turnover, which is crucial for proper neuronal development and function. Dysfunctional mitochondria and disrupted mitophagy pathways have been linked to a diverse array of neurological disorders. The nematode Caenorhabditis elegans, with its well-defined nervous system, serves as an excellent model to unravel the intricate involvement of mitophagy in developing neurons. This chapter describes the use of Rosella biosensor in C. elegans to monitor neuronal mitophagy, providing a user-friendly platform for screening genes and drugs affecting mitophagic pathways under physiological conditions or in the context of neurodevelopmental pathologies.


Sujet(s)
Caenorhabditis elegans , Mitochondries , Mitophagie , Neurones , Animaux , Caenorhabditis elegans/métabolisme , Neurones/métabolisme , Neurones/cytologie , Mitochondries/métabolisme , Techniques de biocapteur/méthodes , Protéines de Caenorhabditis elegans/métabolisme , Protéines de Caenorhabditis elegans/génétique
12.
Methods Mol Biol ; 2845: 141-150, 2024.
Article de Anglais | MEDLINE | ID: mdl-39115663

RÉSUMÉ

We outline our approach for studying the selective autophagy of peroxisomes (pexophagy), using fluorescence microscopy in tissue cell culture models. Ratiometric reporters, which specifically localize to peroxisomes, allow a quantitative assessment of pexophagy in fixed and live cells, as well as whole organisms. We discuss chemical and physiological inducers of pexophagy and any overlap with the induction of mitophagy.


Sujet(s)
Microscopie de fluorescence , Péroxysomes , Péroxysomes/métabolisme , Microscopie de fluorescence/méthodes , Humains , Animaux , Autophagie/physiologie , Mitophagie
13.
Methods Mol Biol ; 2845: 151-160, 2024.
Article de Anglais | MEDLINE | ID: mdl-39115664

RÉSUMÉ

Mitochondria-targeted Keima (mt-Keima) is a pH-sensitive, acid-stable fluorescent protein used for the quantification of mitophagy. Mt-Keima contains a mitochondrial matrix targeting sequence and has bimodal excitation with peaks at 440 nM in neutral environments and 586 nM in acidic environments. From this bimodal excitation, a ratiometric signal may be calculated to quantify mitophagy in live cells. This chapter describes procedures for measuring mitophagy by flow cytometry and live cell confocal microscopy with mt-Keima.


Sujet(s)
Cytométrie en flux , Microscopie confocale , Mitochondries , Mitophagie , Humains , Mitochondries/métabolisme , Microscopie confocale/méthodes , Cytométrie en flux/méthodes , Protéines luminescentes/métabolisme , Protéines luminescentes/génétique , Cellules HeLa , Concentration en ions d'hydrogène
14.
Methods Mol Biol ; 2845: 161-175, 2024.
Article de Anglais | MEDLINE | ID: mdl-39115665

RÉSUMÉ

The purpose of this protocol is to provide a comprehensive, stepwise guide for assessing mitophagy flux utilizing a live-cell mt-KEIMA approach. The proposed protocol is sensitive, reproducible, quantitative, and easy to perform. While mitophagy has been extensively studied, current methodologies primarily focus on terminal measurements, neglecting the dynamic aspect of this process. Hence, the introduction of this straightforward live-cell mitophagy tracing protocol enables real-time monitoring of the dynamics of mitochondrial selective autophagy, thereby enhancing the ability to draw conclusions regarding key regulators and the reversibility of the process. The assay employs a lentiviral approach to induce mt-KEIMA expression in primary or immortalized cell lines. Subsequently, the respective mitophagy reporter cells are observed using a live-cell imaging system at specific time intervals, and further quantification allows the detection of mitophagy flux. This protocol has proven efficacious in investigating mitophagy flux, including responses to chemical inducers or genetically modified cells over time. Notably, this approach is well-suited for large throughput screening of chemicals or appropriate gene-editing libraries that may influence mitophagy responses in cells.


Sujet(s)
Mitochondries , Mitophagie , Humains , Mitochondries/métabolisme , Lignée cellulaire , Lentivirus/génétique
15.
Theranostics ; 14(11): 4278-4296, 2024.
Article de Anglais | MEDLINE | ID: mdl-39113800

RÉSUMÉ

Background: Ulcerative colitis (UC) is an intestinal inflammatory disease that is strongly associated with mitochondrial damage and dysfunction as well as mitophagy and lacks of satisfactory treatments. Hair follicle mesenchymal stem cell (HF-MSC)-derived exosomes owe benefit effectiveness on inflammatory therapies. Hypoxia-preconditioned HF-MSCs exhibit enhanced proliferation and migration abilities, and their exosomes exert stronger effects than normal exosomes. However, the therapeutic function of Hy-Exos in UC is unknown. Methods: The inflammation model was established with LPS-treated MODE-K cells, and the mouse UC model was established by dextran sulfate sodium (DSS) administration. The therapeutic effects of HF-MSC-derived exosomes (Exos) and hypoxia-preconditioned HF-MSC-derived exosomes (Hy-Exos) were compared in vitro and in vivo. Immunofluorescence staining and western blotting were used to explore the effects of Hy-Exos on mitochondrial function, mitochondrial fission and fusion and mitophagy. MiRNA sequencing analysis was applied to investigate the differences in components between Exos and Hy-Exos. Results: Hy-Exos had a better therapeutic effect on LPS-treated MODE-K cells and DSS-induced UC mice. Hy-Exos promoted colonic tight junction proteins expression, suppressed the oxidative stress response, and reduced UC-related inflammatory injury. Hy-Exos may exert these effects via miR-214-3p-mediated inhibition of the PI3K/AKT/mTOR signaling pathway, maintenance of mitochondrial dynamic stability, alleviation of mitochondrial dysfunction and enhancement of mitophagy. Conclusion: This study revealed a vital role for Hy-Exos in suppressing inflammatory progression in UC and suggested that miR-214-3p is a potential critical target for Hy-Exos in alleviating UC.


Sujet(s)
Rectocolite hémorragique , Modèles animaux de maladie humaine , Exosomes , Follicule pileux , Cellules souches mésenchymateuses , Mitophagie , Phosphatidylinositol 3-kinases , Protéines proto-oncogènes c-akt , Transduction du signal , Sérine-thréonine kinases TOR , Animaux , Rectocolite hémorragique/métabolisme , Rectocolite hémorragique/thérapie , Rectocolite hémorragique/anatomopathologie , Cellules souches mésenchymateuses/métabolisme , Exosomes/métabolisme , Souris , Protéines proto-oncogènes c-akt/métabolisme , Sérine-thréonine kinases TOR/métabolisme , Phosphatidylinositol 3-kinases/métabolisme , Follicule pileux/métabolisme , Sulfate dextran , Mâle , Mitochondries/métabolisme , Souris de lignée C57BL , microARN/métabolisme , microARN/génétique , Humains
16.
Int J Immunopathol Pharmacol ; 38: 3946320241271724, 2024.
Article de Anglais | MEDLINE | ID: mdl-39116410

RÉSUMÉ

This study aimed to investigate whether the beneficial effects of PCA on chondrocyte senescence are mediated through the regulation of mitophagy. Chondrocyte senescence plays a significant role in the development and progression of knee osteoarthritis (OA). The compound protocatechuic aldehyde (PCA), which is abundant in the roots of Salvia miltiorrhiza, has been reported to have antioxidant properties and the ability to protect against cellular senescence. To achieve this goal, a destabilization of the medial meniscus (DMM)-induced mouse OA model and a lipopolysaccharide (LPS)-induced chondrocyte senescence model were used, in combination with PINK1 gene knockdown or overexpression. After treatment with PCA, cellular senescence was assessed using Senescence-Associated ß-Galactosidase (SA-ß-Gal) staining, DNA damage was evaluated using Hosphorylation of the Ser-139 (γH2AX) staining, reactive oxygen species (ROS) levels were measured using Dichlorodihydrofluorescein diacetate (DCFH-DA) staining, mitochondrial membrane potential was determined using a 5,5',6,6'-TETRACHLORO-1,1',3,3'-*. TETRAETHYBENZIMIDA (JC-1) kit, and mitochondrial autophagy was examined using Mitophagy staining. Western blot analysis was also performed to detect changes in senescence-related proteins, PINK1/Parkin pathway proteins, and mitophagy-related proteins. Our results demonstrated that PCA effectively reduced chondrocyte senescence, increased the mitochondrial membrane potential, facilitated mitochondrial autophagy, and upregulated the PINK1/Parkin pathway. Furthermore, silencing PINK1 weakened the protective effects of PCA, whereas PINK1 overexpression enhanced the effects of PCA on LPS-induced chondrocytes. PCA attenuates chondrocyte senescence by regulating PINK1/Parkin-mediated mitochondrial autophagy, ultimately reducing cartilage degeneration.


Sujet(s)
Benzaldéhydes , Catéchols , Vieillissement de la cellule , Chondrocytes , Mitophagie , Protein kinases , Ubiquitin-protein ligases , Chondrocytes/effets des médicaments et des substances chimiques , Chondrocytes/métabolisme , Chondrocytes/anatomopathologie , Animaux , Vieillissement de la cellule/effets des médicaments et des substances chimiques , Ubiquitin-protein ligases/métabolisme , Ubiquitin-protein ligases/génétique , Mitophagie/effets des médicaments et des substances chimiques , Protein kinases/métabolisme , Souris , Catéchols/pharmacologie , Benzaldéhydes/pharmacologie , Espèces réactives de l'oxygène/métabolisme , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/métabolisme , Mitochondries/anatomopathologie , Mâle , Souris de lignée C57BL , Autophagie/effets des médicaments et des substances chimiques , Potentiel de membrane mitochondriale/effets des médicaments et des substances chimiques , Gonarthrose/anatomopathologie , Gonarthrose/métabolisme , Gonarthrose/traitement médicamenteux
17.
Commun Biol ; 7(1): 961, 2024 Aug 08.
Article de Anglais | MEDLINE | ID: mdl-39117722

RÉSUMÉ

Parkinson's disease (PD) is the second most common neurodegenerative disease in the world. Although most cases are sporadic and occur later in life, 10-15% of cases are genetic. Loss-of-function mutations in the ring-between-ring E3 ubiquitin ligase parkin, encoded by the PRKN gene, cause autosomal recessive forms of early onset PD. Together with the kinase PINK1, parkin forms a mitochondrial quality control pathway that tags damaged mitochondria for clearance. Under basal conditions, parkin is inhibited and compounds that increase its activity have been proposed as a therapy for PD. Recently, several naturally occurring hyperactive parkin variants were identified, which increased mitophagy in cultured cells. Here, we validate the hyperactivities of these variants in vitro and compare the levels of activity of the variants to those of the wild-type and the well-characterized hyperactive variant, W403A. We also study the effects of mutating the parkin ACT (activating element) on parkin activity in vitro. This work advances our understanding of the pathogenicity of parkin variants and is an important first step in the design of molecules to increase parkin activity.


Sujet(s)
Ubiquitin-protein ligases , Ubiquitin-protein ligases/génétique , Ubiquitin-protein ligases/métabolisme , Humains , Maladie de Parkinson/génétique , Maladie de Parkinson/métabolisme , Mutation , Mitophagie/génétique , Mitochondries/métabolisme , Mitochondries/génétique , Cellules HEK293
18.
Cell Death Dis ; 15(7): 473, 2024 Jul 02.
Article de Anglais | MEDLINE | ID: mdl-38956064

RÉSUMÉ

Damage to renal tubular epithelial cells (RTECs) signaled the onset and progression of sepsis-associated acute kidney injury (SA-AKI). Recent research on mitochondria has revealed that mitophagy plays a crucial physiological role in alleviating injury to RTECs and it is suppressed progressively by the inflammation response in SA-AKI. However, the mechanism by which inflammation influences mitophagy remains poorly understood. We examined how macrophage migration inhibitory factor (MIF), a pro-inflammatory protein, influences the PINK1-Parkin pathway of mitophagy by studying protein-protein interactions when MIF was inhibited or overexpressed. Surprisingly, elevated levels of MIF were found to directly bind to PINK1, disrupting its interaction with Parkin. This interference hindered the recruitment of Parkin to mitochondria and impeded the initiation of mitophagy. Furthermore, this outcome led to significant apoptosis of RTECs, which could, however, be reversed by an MIF inhibitor ISO-1 and/or a new mitophagy activator T0467. These findings highlight the detrimental impact of MIF on renal damage through its disruption of the interaction between PINK1 and Parkin, and the therapeutic potential of ISO-1 and T0467 in mitigating SA-AKI. This study offers a fresh perspective on treating SA-AKI by targeting MIF and mitophagy.


Sujet(s)
Atteinte rénale aigüe , Facteurs inhibiteurs de la migration des macrophages , Mitophagie , Protein kinases , Sepsie , Ubiquitin-protein ligases , Facteurs inhibiteurs de la migration des macrophages/métabolisme , Facteurs inhibiteurs de la migration des macrophages/génétique , Atteinte rénale aigüe/métabolisme , Atteinte rénale aigüe/anatomopathologie , Ubiquitin-protein ligases/métabolisme , Ubiquitin-protein ligases/génétique , Protein kinases/métabolisme , Sepsie/complications , Sepsie/métabolisme , Animaux , Humains , Mitochondries/métabolisme , Tubules rénaux/métabolisme , Tubules rénaux/anatomopathologie , Cellules épithéliales/métabolisme , Cellules épithéliales/anatomopathologie , Apoptose , Liaison aux protéines , Mâle , Intramolecular oxidoreductases/métabolisme
19.
Cardiovasc Diabetol ; 23(1): 261, 2024 Jul 18.
Article de Anglais | MEDLINE | ID: mdl-39026280

RÉSUMÉ

Mitochondria play a central role in cellular energy metabolism, and their dysfunction is increasingly recognized as a critical factor in the pathogenesis of diabetes-related cardiac pathophysiology, including vulnerability to ischemic events that culminate in myocardial infarction on the one hand and ventricular arrhythmias on the other. In diabetes, hyperglycemia and altered metabolic substrates lead to excessive production of reactive oxygen species (ROS) by mitochondria, initiating a cascade of oxidative stress that damages mitochondrial DNA, proteins, and lipids. This mitochondrial injury compromises the efficiency of oxidative phosphorylation, leading to impaired ATP production. The resulting energy deficit and oxidative damage contribute to functional abnormalities in cardiac cells, placing the heart at an increased risk of electromechanical dysfunction and irreversible cell death in response to ischemic insults. While cardiac mitochondria are often considered to be relatively autonomous entities in their capacity to produce energy and ROS, their highly dynamic nature within an elaborate network of closely-coupled organelles that occupies 30-40% of the cardiomyocyte volume is fundamental to their ability to exert intricate regulation over global cardiac function. In this article, we review evidence linking the dynamic properties of the mitochondrial network to overall cardiac function and its response to injury. We then highlight select studies linking mitochondrial ultrastructural alterations driven by changes in mitochondrial fission, fusion and mitophagy in promoting cardiac ischemic injury to the diabetic heart.


Sujet(s)
Cardiomyopathies diabétiques , Métabolisme énergétique , Mitochondries du myocarde , Ischémie myocardique , Stress oxydatif , Humains , Mitochondries du myocarde/métabolisme , Mitochondries du myocarde/anatomopathologie , Animaux , Cardiomyopathies diabétiques/métabolisme , Cardiomyopathies diabétiques/physiopathologie , Cardiomyopathies diabétiques/anatomopathologie , Cardiomyopathies diabétiques/étiologie , Ischémie myocardique/métabolisme , Ischémie myocardique/physiopathologie , Ischémie myocardique/anatomopathologie , Dynamique mitochondriale , Mitophagie , Espèces réactives de l'oxygène/métabolisme , Myocytes cardiaques/métabolisme , Myocytes cardiaques/anatomopathologie , Transduction du signal
20.
Alzheimers Res Ther ; 16(1): 160, 2024 Jul 19.
Article de Anglais | MEDLINE | ID: mdl-39030577

RÉSUMÉ

BACKGROUND: Alpha-lipoic acid (ALA) has a neuroprotective effect on neurodegenerative diseases. In the clinic, ALA can improve cognitive impairments in patients with Alzheimer's disease (AD) and other dementias. Animal studies have confirmed the anti-amyloidosis effect of ALA, but its underlying mechanism remains unclear. In particular, the role of ALA in amyloid-ß precursor protein (APP) metabolism has not been fully elucidated. OBJECTIVE: To investigate whether ALA can reduce the amyloidogenic effect of APP in a transgenic mouse model of AD, and to study the mechanism underlying this effect. METHODS: ALA was infused into 2-month-old APP23/PS45 transgenic mice for 4 consecutive months and their cognitive function and AD-like pathology were then evaluated. An ALA drug concentration gradient was applied to 20E2 cells in vitro to evaluate its effect on the expression of APP proteolytic enzymes and metabolites. The mechanism by which ALA affects APP processing was studied using GI254023X, an inhibitor of A Disintegrin and Metalloproteinase 10 (ADAM10), as well as the mitochondrial toxic drug carbonyl cyanide m-chlorophenylhydrazone (CCCP). RESULTS: Administration of ALA ameliorated amyloid plaque neuropathology in the brain tissue of APP23/PS45 mice and reduced learning and memory impairment. ALA also increased the expression of ADAM10 in 20E2 cells and the non-amyloidogenic processing of APP to produce the 83 amino acid C-terminal fragment (C83). In addition to activating autophagy, ALA also significantly promoted mitophagy. BNIP3L-knockdown reduced the mat/pro ratio of ADAM10. By using CCCP, ALA was found to regulate BNIP3L-mediated mitophagy, thereby promoting the α-cleavage of APP. CONCLUSIONS: The enhanced α-secretase cleavage of APP by ADAM10 is the primary mechanism through which ALA ameliorates the cognitive deficits in APP23/PS45 transgenic mice. BNIP3L-mediated mitophagy contributes to the anti-amyloid properties of ALA by facilitating the maturation of ADAM10. This study provides novel experimental evidence for the treatment of AD with ALA.


Sujet(s)
Protéine ADAM10 , Amyloid precursor protein secretases , Précurseur de la protéine bêta-amyloïde , Dysfonctionnement cognitif , Souris transgéniques , Mitophagie , Acide lipoïque , Animaux , Acide lipoïque/pharmacologie , Mitophagie/effets des médicaments et des substances chimiques , Protéine ADAM10/métabolisme , Souris , Précurseur de la protéine bêta-amyloïde/génétique , Précurseur de la protéine bêta-amyloïde/métabolisme , Dysfonctionnement cognitif/traitement médicamenteux , Dysfonctionnement cognitif/métabolisme , Amyloid precursor protein secretases/métabolisme , Maladie d'Alzheimer/traitement médicamenteux , Maladie d'Alzheimer/métabolisme , Maladie d'Alzheimer/génétique , Modèles animaux de maladie humaine , Protéines membranaires/métabolisme , Protéines membranaires/génétique , Neuroprotecteurs/pharmacologie , Souris de lignée C57BL , Mâle
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