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Neurobiology of Disease Jun 2024Ataxia Telangiectasia (AT) is a rare disorder caused by mutations in the ATM gene and results in progressive neurodegeneration for reasons that remain poorly understood....
Ataxia Telangiectasia (AT) is a rare disorder caused by mutations in the ATM gene and results in progressive neurodegeneration for reasons that remain poorly understood. In addition to its central role in nuclear DNA repair, ATM operates outside the nucleus to regulate metabolism, redox homeostasis and mitochondrial function. However, a systematic investigation into how and when loss of ATM affects these parameters in relevant human neuronal models of AT was lacking. We therefore used cortical neurons and brain organoids from AT-patient iPSC and gene corrected isogenic controls to reveal levels of mitochondrial dysfunction, oxidative stress, and senescence that vary with developmental maturity. Transcriptome analyses identified disruptions in regulatory networks related to mitochondrial function and maintenance, including alterations in the PARP/SIRT signalling axis and dysregulation of key mitophagy and mitochondrial fission-fusion processes. We further show that antioxidants reduce ROS and restore neurite branching in AT neuronal cultures, and ameliorate impaired neuronal activity in AT brain organoids. We conclude that progressive mitochondrial dysfunction and aberrant ROS production are important contributors to neurodegeneration in AT and are strongly linked to ATM's role in mitochondrial homeostasis regulation.
PubMed: 38876322
DOI: 10.1016/j.nbd.2024.106562 -
Journal of Dairy Science Jun 2024Mitochondrial dysfunction has been reported to occur in the mammary gland of dairy cows suffering from ketosis. Prohibitin 2 (PHB2) plays a crucial role in regulating...
Mitochondrial dysfunction has been reported to occur in the mammary gland of dairy cows suffering from ketosis. Prohibitin 2 (PHB2) plays a crucial role in regulating mitophagy, which clears impaired mitochondria to maintain normal mitochondrial function. Therefore, the current study aimed to investigate how PHB2 mediates mitophagy, thereby influencing mitochondrial function in the bovine mammary epithelial cell MAC-T. First, mammary gland tissue and blood samples were collected from healthy cows (control; n = 15, BHB <0.6 mM) and cows with clinical ketosis (CK; n = 15, BHB >3.0 mM). Compared with the control group, the CK group exhibited lower dry matter intake (DMI), milk production, milk protein, milk lactose, and serum glucose. In contrast, milk fat, serum nonesterified fatty acids (NEFA) and BHB were greater in CK group. The protein abundance of PHB2, peroxisome proliferator activated receptor-γ coactivator-1α (PGC-1α), mitofusin 2 (MFN2) in whole cell lysates (WCL), as well as PHB2, sequestosome-1 (SQSTM1, also called p62), microtubule-associated protein 1 light chain 3-II (LC3-II), and ubiquitinated proteins in mitochondrial fraction were significantly lower in the CK group. ATP content of mammary gland tissue in CK group was lower than that of healthy cows. Second, MAC-T were cultured and treated with NEFA (0, 0.3, 0.6, 1.2 mM). MAC-T treated with 1.2 mM NEFA displayed decreased protein abundance of PHB2, PGC-1α, MFN2 in WCL, as well as protein abundance of PHB2, p62, LC3-II, and ubiquitinated proteins in mitochondrial fraction. The content of ATP and JC-1 aggregates in 1.2 mM NEFA group were lower than in the 0 mM NEFA group. Additionally, 1.2 mM NEFA disrupted the fusion between mitochondria and lysosomes. MAC-T were then pretreated with 100 nM rapamycin, followed by treatment with or without NEFA. Rapamycin alleviated impaired mitophagy and mitochondria dysfunction induced by 1.2 mM NEFA. Third, MAC-T were transfected with small interfering RNA to silence PHB2 or a plasmid for overexpression of PHB2, followed by treatment with or without NEFA. The silencing of PHB2 aggravated 1.2 mM NEFA induced impaired mitophagy and mitochondrial dysfunction, whereas the overexpression of PHB2 alleviated these effects. Overall, this study provides evidence that PHB2, in regulation of mitophagy, is a mechanism for bovine mammary epithelial cells to counteract NEFA-induced mitochondrial dysfunction.
PubMed: 38876225
DOI: 10.3168/jds.2024-24800 -
Ecotoxicology and Environmental Safety Jul 2024Aflatoxin B1 (AFB1) is commonly found in feed ingredients and foods all over the world, posing a significant threat to food safety and public health in animals and...
Aflatoxin B1 (AFB1) is commonly found in feed ingredients and foods all over the world, posing a significant threat to food safety and public health in animals and humans. Lactobacillus salivarius (L. salivarius) was recorded to improve the intestinal health and performance of chickens. However, whether L. salivarius can alleviate AFB1-induced hepatotoxicity in geese was unknown. A total of 300 Lande geese were randomly assigned to five groups: control group, AFB1 low-dose group (L), L. salivarius+AFB1 low-dose group (LL), AFB1 high dosage groups (H), L. salivarius+AFB1 high dosage groups (LH), respectively. The results showed that the concentrations of ALT, AST, and GGT significantly increased after exposure to AFB1. Similarly, severe damage of hepatic morphology was observed including the hepatic structure injury and inflammatory cell infiltration. The oxidative stress was evidenced by the elevated concentrations of MDA, and decreased activities of GSH-Px, GSH and SOD. The observation of immunofluorescence, real-time PCR, and western blotting showed that the expression of PINK1 and the value of LC3II/LC3I were increased, but that of p62 significantly decreased after AFB1 exposure. Moreover, the supplementation of L. salivarius effectively improved the geese performance, ameliorated AFB1-induced oxidative stress, inhibited mitochondrial mitophagy and enhanced the liver restoration to normal level. The present study demonstrated that L. salivarius ameliorated AFB1-induced the hepatotoxicity by decreasing the oxidative stress, and regulating the expression of PINK1/Parkin-mediated mitophagy in the mitochondria of the geese liver. Furthermore, this investigation suggested that L. salivarius might serve as a novel and safe additive for preventing AFB1 contamination in poultry feed.
Topics: Animals; Aflatoxin B1; Geese; Mitophagy; Ubiquitin-Protein Ligases; Ligilactobacillus salivarius; Liver; Protein Kinases; Chemical and Drug Induced Liver Injury; Oxidative Stress; Probiotics
PubMed: 38875822
DOI: 10.1016/j.ecoenv.2024.116574 -
Scientific Reports Jun 2024Barth syndrome (BTHS) is a lethal rare genetic disorder, which results in cardiac dysfunction, severe skeletal muscle weakness, immune issues and growth delay. Mutations...
Barth syndrome (BTHS) is a lethal rare genetic disorder, which results in cardiac dysfunction, severe skeletal muscle weakness, immune issues and growth delay. Mutations in the TAFAZZIN gene, which is responsible for the remodeling of the phospholipid cardiolipin (CL), lead to abnormalities in mitochondrial membrane, including alteration of mature CL acyl composition and the presence of monolysocardiolipin (MLCL). The dramatic increase in the MLCL/CL ratio is the hallmark of patients with BTHS, which is associated with mitochondrial bioenergetics dysfunction and altered membrane ultrastructure. There are currently no specific therapies for BTHS. Here, we showed that cardiac mitochondria isolated from TAFAZZIN knockdown (Taz) mice presented abnormal ultrastructural membrane morphology, accumulation of vacuoles, pro-fission conditions and defective mitophagy. Interestingly, we found that in vivo treatment of Taz mice with a CL-targeted small peptide (named SS-31) was able to restore mitochondrial morphology in tafazzin-deficient heart by affecting specific proteins involved in dynamic process and mitophagy. This agrees with our previous data showing an improvement in mitochondrial respiratory efficiency associated with increased supercomplex organization in Taz mice under the same pharmacological treatment. Taken together our findings confirm the beneficial effect of SS-31 in the amelioration of tafazzin-deficient dysfunctional mitochondria in a BTHS animal model.
Topics: Animals; Barth Syndrome; Mitophagy; Disease Models, Animal; Mice; Acyltransferases; Cardiolipins; Mitochondria, Heart; Transcription Factors; Lysophospholipids; Mice, Knockout; Oligopeptides
PubMed: 38871974
DOI: 10.1038/s41598-024-64368-y -
International Journal of Reproductive... Mar 2023Bisphenol A (BPA), an endocrine-disrupting agent, is widely used as polycarbonate plastics for producing food containers. BPA exposure at environmentally relevant...
BACKGROUND
Bisphenol A (BPA), an endocrine-disrupting agent, is widely used as polycarbonate plastics for producing food containers. BPA exposure at environmentally relevant concentrations can cause reproductive disorders.
OBJECTIVE
The effect of Naringenin (NG) on BPA-induced Sertoli cell toxicity and its mechanism was examined in the present study.
MATERIALS AND METHODS
In this experimental-laboratory study, the mouse TM4 cells were treated to BPA (0.8 μM) or NG for 24 hr at concentrations of 10, 20, and 50 μg/ml. Cell viability, reactive oxygen species (ROS) production, malondialdehyde (MDA) content, antioxidant level, and mitochondrial membrane potential (MMP) were examined. The expression of mitophagy-related genes, including Parkin and PTEN-induced putative kinase 1 (Pink1), was also evaluated.
RESULTS
BPA significantly lowered the viability of the Sertoli cells (p= 0.004). Pink1 and Parkin levels of the BPA group were significantly increased (p 0.001), while the MMP was considerably decreased (p 0.001). BPA raised MDA and ROS levels (p 0.001) and reduced antioxidant biomarkers (p= 0.003). NG at the 20 and 50 μg/ml concentrations could significantly improve the viability and MMP of TM4 cells (p= 0.034). NG depending on concentration, could decrease Pink1 and Parkin at mRNA and protein levels compared to the BPA group (p = 0.024). NG enhanced antioxidant factors, while ROS and MDA levels were decreased in the BPA-exposed cells.
CONCLUSION
The beneficial impacts of NG on BPA-exposed Sertoli cells are related to the suppression of mitophagy and the reduction of oxidative stress.
PubMed: 38868445
DOI: 10.18502/ijrm.v22i3.16166 -
Molecular Medicine (Cambridge, Mass.) Jun 2024Deep vein thrombosis (DVT) is a common vascular surgical disease caused by the coagulation of blood in the deep veins, and predominantly occur in the lower limbs....
BACKGROUND
Deep vein thrombosis (DVT) is a common vascular surgical disease caused by the coagulation of blood in the deep veins, and predominantly occur in the lower limbs. Endothelial progenitor cells (EPCs) are multi-functional stem cells, which are precursors of vascular endothelial cells. EPCs have gradually evolved into a promising treatment strategy for promoting deep vein thrombus dissolution and recanalization through the stimulation of various physical and chemical factors.
METHODS
In this study, we utilized a mouse DVT model and performed several experiments including qRT-PCR, Western blot, tube formation, wound healing, Transwell assay, immunofluorescence, flow cytometry analysis, and immunoprecipitation to investigate the role of HOXD9 in the function of EPCs cells. The therapeutic effect of EPCs overexpressing HOXD9 on the DVT model and its mechanism were also explored.
RESULTS
Overexpression of HOXD9 significantly enhanced the angiogenesis and migration abilities of EPCs, while inhibiting cell apoptosis. Additionally, results indicated that HOXD9 specifically targeted the HRD1 promoter region and regulated the downstream PINK1-mediated mitophagy. Interestingly, intravenous injection of EPCs overexpressing HOXD9 into mice promoted thrombus dissolution and recanalization, significantly decreasing venous thrombosis.
CONCLUSIONS
The findings of this study reveal that HOXD9 plays a pivotal role in stimulating vascular formation in endothelial progenitor cells, indicating its potential as a therapeutic target for DVT management.
Topics: Animals; Endothelial Progenitor Cells; Mice; Venous Thrombosis; Homeodomain Proteins; Mitophagy; Disease Models, Animal; Neovascularization, Physiologic; Cell Movement; Male; Apoptosis; Humans; Angiogenesis
PubMed: 38867168
DOI: 10.1186/s10020-024-00852-5 -
Annals of Human Biology Feb 2024Mitophagy and ferroptosis occur in intracerebral haemorrhage (ICH) but our understanding of mitophagy and ferroptosis-related genes remains incomplete.
BACKGROUND
Mitophagy and ferroptosis occur in intracerebral haemorrhage (ICH) but our understanding of mitophagy and ferroptosis-related genes remains incomplete.
AIM
This study aims to identify shared ICH genes for both processes.
METHODS
ICH differentially expressed mitophagy and ferroptosis-related genes (DEMFRGs) were sourced from the GEO database and literature. Enrichment analysis elucidated functions. Hub genes were selected via STRING, MCODE, and MCC algorithms in Cytoscape. miRNAs targeting hubs were predicted using miRWalk 3.0, forming a miRNA-hub gene network. Immune microenvironment variances were assessed with MCP and TIMER. Potential small molecules for ICH were forecasted CMap database.
RESULTS
64 DEMFRGs and ten hub genes potentially involved in various processes like ferroptosis, TNF signalling pathway, MAPK signalling pathway, and NF-kappa B signalling pathway were discovered. Several miRNAs were identified as shared targets of hub genes. The ICH group showed increased infiltration of monocytic lineage and myeloid dendritic cells compared to the Healthy group. Ten potential small molecule drugs (e.g. Zebularine, TWS-119, CG-930) were predicted CMap.
CONCLUSION
Several shared genes between mitophagy and ferroptosis potentially drive ICH progression TNF, MAPK, and NF-kappa B pathways. These results offer valuable insights for further exploring the connection between mitophagy, ferroptosis, and ICH.
Topics: Mitophagy; Ferroptosis; Cerebral Hemorrhage; Humans; Computational Biology; MicroRNAs; Gene Regulatory Networks
PubMed: 38863372
DOI: 10.1080/03014460.2024.2334719 -
Cell Death Discovery Jun 2024Hypoxic-ischaemic encephalopathy (HIE) in termed infants remains a significant cause of morbidity and mortality worldwide despite the introduction of therapeutic... (Review)
Review
Hypoxic-ischaemic encephalopathy (HIE) in termed infants remains a significant cause of morbidity and mortality worldwide despite the introduction of therapeutic hypothermia. Depending on the cell type, cellular context, metabolic predisposition and insult severity, cell death in the injured immature brain can be highly heterogenous. A continuum of cell death exists in the H/I-injured immature brain. Aside from apoptosis, emerging evidence supports the pathological activation of necroptosis, pyroptosis and ferroptosis as alternative regulated cell death (RCD) in HIE to trigger neuroinflammation and metabolic disturbances in addition to cell loss. Upregulation of autophagy and mitophagy in HIE represents an intrinsic neuroprotective strategy. Molecular crosstalk between RCD pathways implies one RCD mechanism may compensate for the loss of function of another. Moreover, mitochondrion was identified as the signalling "hub" where different RCD pathways converge. The highly-orchestrated nature of RCD makes them promising therapeutic targets. Better understanding of RCD mechanisms and crosstalk between RCD subtypes likely shed light on novel therapy development for HIE. The identification of a potential RCD converging node may open up the opportunity for simultaneous and synergistic inhibition of cell death in the immature brain.
PubMed: 38862503
DOI: 10.1038/s41420-024-02014-2 -
MBio Jun 2024Sepsis and chronic infections with , a leading "ESKAPE" bacterial pathogen, are associated with increased morbidity and mortality and skeletal muscle atrophy. The...
UNLABELLED
Sepsis and chronic infections with , a leading "ESKAPE" bacterial pathogen, are associated with increased morbidity and mortality and skeletal muscle atrophy. The actions of this pathogen on skeletal muscle remain poorly understood. In skeletal muscle, mitochondria serve as a crucial energy source, which may be perturbed by infection. Here, using the well-established backburn and infection model of murine infection we deciphered the systemic impact of the quorum-sensing transcription factor MvfR (multiple virulence factor regulator) by interrogating, 5 days post-infection, its effect on mitochondrial-related functions in the gastrocnemius skeletal muscle and the outcome of the pharmacological inhibition of MvfR function and that of the mitochondrial-targeted peptide, Szeto-Schiller 31 (SS-31). Our findings show that the MvfR perturbs adenosine triphosphate generation, oxidative phosphorylation, and antioxidant response, elevates the production of reactive oxygen species, and promotes oxidative damage of mitochondrial DNA in the gastrocnemius muscle of infected mice. These impairments in mitochondrial-related functions were corroborated by the alteration of key mitochondrial proteins involved in electron transport, mitochondrial biogenesis, dynamics and quality control, and mitochondrial uncoupling. Pharmacological inhibition of MvfR using the potent anti-MvfR lead, D88, we developed, or the mitochondrial-targeted peptide SS-31 rescued the MvfR-mediated alterations observed in mice infected with the wild-type strain PA14. Our study provides insights into the actions of MvfR in orchestrating mitochondrial dysfunction in the skeletal murine muscle, and it presents novel therapeutic approaches for optimizing clinical outcomes in affected patients.
IMPORTANCE
Skeletal muscle, pivotal for many functions in the human body, including breathing and protecting internal organs, contains abundant mitochondria essential for maintaining cellular homeostasis during infection. The effect of (PA) infections on skeletal muscle remains poorly understood. Our study delves into the role of a central quorum-sensing transcription factor, multiple virulence factor regulator (MvfR), that controls the expression of multiple acute and chronic virulence functions that contribute to the pathogenicity of PA. The significance of our study lies in the role of MvfR in the metabolic perturbances linked to mitochondrial functions in skeletal muscle and the effectiveness of the novel MvfR inhibitor and the mitochondrial-targeted peptide SS-31 in alleviating the mitochondrial disturbances caused by PA in skeletal muscle. Inhibiting MvfR or interfering with its effects can be a potential therapeutic strategy to curb PA virulence.
PubMed: 38860823
DOI: 10.1128/mbio.01292-24 -
Neurobiology of Disease Aug 2024Neuroinflammation and mitochondrial dysfunction are closely intertwined with the pathophysiology of neurological disorders. Recent studies have elucidated profound... (Review)
Review
Neuroinflammation and mitochondrial dysfunction are closely intertwined with the pathophysiology of neurological disorders. Recent studies have elucidated profound alterations in mitochondrial dynamics across a spectrum of neurological disorders. Dynamin-related protein 1 (DRP1) emerges as a pivotal regulator of mitochondrial fission, with its dysregulation disrupting mitochondrial homeostasis and fueling neuroinflammation, thereby exacerbating disease severity. In addition to its role in mitochondrial dynamics, DRP1 plays a crucial role in modulating inflammation-related pathways. This review synthesizes important functions of DRP1 in the central nervous system (CNS) and the impact of epigenetic modification on the progression of neurodegenerative diseases. The intricate interplay between neuroinflammation and DRP1 in microglia and astrocytes, central contributors to neuroinflammation, is expounded upon. Furthermore, the use of DRP1 inhibitors to influence the activation of microglia and astrocytes, as well as their involvement in processes such as mitophagy, mitochondrial oxidative stress, and calcium ion transport in CNS-mediated neuroinflammation, is scrutinized. The modulation of microglia to astrocyte crosstalk by DRP1 and its role in inflammatory neurodegeneration is also highlighted. Overall, targeting DRP1 presents a promising avenue for ameliorating neuroinflammation and enhancing the therapeutic management of neurological disorders.
Topics: Dynamins; Humans; Mitochondrial Dynamics; Neurodegenerative Diseases; Animals; Neuroinflammatory Diseases; Inflammation; Astrocytes; Microglia; Mitochondria
PubMed: 38857809
DOI: 10.1016/j.nbd.2024.106561