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BioRxiv : the Preprint Server For... Jun 2024Angiogenesis plays a vital role for postnatal development and tissue repair following ischemia. Reactive oxygen species (ROS) generated by NADPH oxidases (NOXes) and...
Angiogenesis plays a vital role for postnatal development and tissue repair following ischemia. Reactive oxygen species (ROS) generated by NADPH oxidases (NOXes) and mitochondria act as signaling molecules that promote angiogenesis in endothelial cells (ECs) which mainly relies on aerobic glycolysis for ATP production. However, the connections linking redox signaling with glycolysis are not well understood. The GTPase Drp1 is a member of the dynamin superfamily that moves from cytosol to mitochondria through posttranslational modifications to induce mitochondrial fission. The role of Drp1 in ROS-dependent VEGF signaling and angiogenesis in ECs has not been previously described. Here, we identify an unexpected function of endothelial Drp1 as a redox sensor, transmitting VEGF-induced H O signals to enhance glycolysis and angiogenesis. Loss of Drp1 expression in ECs inhibited VEGF-induced angiogenic responses. Mechanistically, VEGF rapidly induced the NOX4-dependent sulfenylation (CysOH) of Drp1 on Cys , promoting disulfide bond formation with the metabolic kinase AMPK and subsequent sulfenylation of AMPK at Cys via the mitochondrial fission-mitoROS axis. This cysteine oxidation of AMPK, in turn, enhanced glycolysis and angiogenesis. , mice with EC-specific Drp1 deficiency or CRISPR/Cas9-engineered "redox-dead" (Cys to Ala) Drp1 knock-in mutations exhibited impaired retinal angiogenesis and post-ischemic neovascularization. Our findings uncover a novel role for endothelial Drp1 in linking VEGF-induced mitochondrial redox signaling to glycolysis through a cysteine oxidation-mediated Drp1-AMPK redox relay, driving both developmental and reparative angiogenesis.
PubMed: 38915542
DOI: 10.1101/2024.06.15.599174 -
Journal of Cancer 2024As we delve into the intricate world of mitochondrial inner membrane proteins, particularly Optic Atrophy types 1 and 3 (OPA1/3), we uncover their pivotal role in...
As we delve into the intricate world of mitochondrial inner membrane proteins, particularly Optic Atrophy types 1 and 3 (OPA1/3), we uncover their pivotal role in maintaining mitochondrial dynamic equilibrium and fusion, crucial for cellular energy production and synthesis. Despite extensive scrutiny, the significance of OPA1/3 in breast cancer (BRCA) and its interplay with the immune microenvironment remain elusive. We meticulously sourced BRCA data from renowned repositories such as The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), Gene Expression Omnibus (GEO), and the Human Protein Atlas (HPA), leveraging cutting-edge techniques including single-cell RNA-sequencing (scRNA-seq), spatial transcriptomics, and pharmacogenomics. Through multifaceted data analysis, we endeavored to unravel the intricate role and potential value of OPA1/3 in BRCA tumorigenesis and progression. Our investigation reveals a conspicuous upregulation of OPA1/3 expression in BRCA, correlating with dismal prognoses. Kaplan-Meier plot analysis underscores that heightened OPA1/3 levels are associated with poor survival rates. Both clinical specimens and biobank biopsies corroborate the elevated expression of OPA1/3 in breast cancer patients. Moreover, scRNA-seq unveils a strong correlation between OPA1/3 and macrophage infiltration in the BRCA immune milieu, alongside its association with the cellular communication network involving CXCL, TGFb, VEGF, and IL16. In light of these findings, OPA1/3 emerges as a promising contender for therapeutic targeting and as a potential diagnostic, prognostic, and survival biomarker in BRCA. The implications of our study underscore the pressing need to explore these novel biomarkers to enhance patient outcomes.
PubMed: 38911373
DOI: 10.7150/jca.96100 -
Nature Communications Jun 2024Chemoresistance is a main reason for treatment failure in patients with nasopharyngeal carcinoma, but the exact regulatory mechanism underlying chemoresistance in...
Chemoresistance is a main reason for treatment failure in patients with nasopharyngeal carcinoma, but the exact regulatory mechanism underlying chemoresistance in nasopharyngeal carcinoma remains to be elucidated. Here, we identify PJA1 as a key E3 ubiquitin ligase involved in nasopharyngeal carcinoma chemoresistance that is highly expressed in nasopharyngeal carcinoma patients with nonresponse to docetaxel-cisplatin-5-fluorouracil induction chemotherapy. We find that PJA1 facilitates docetaxel resistance by inhibiting GSDME-mediated pyroptosis in nasopharyngeal carcinoma cells. Mechanistically, PJA1 promotes the degradation of the mitochondrial protein PGAM5 by increasing its K48-linked ubiquitination at K88, which further facilitates DRP1 phosphorylation at S637 and reduced mitochondrial reactive oxygen species production, resulting in suppression of GSDME-mediated pyroptosis and the antitumour immune response. PGAM5 knockdown fully restores the docetaxel sensitization effect of PJA1 knockdown. Moreover, pharmacological targeting of PJA1 with the small molecule inhibitor RTA402 enhances the docetaxel sensitivity of nasopharyngeal carcinoma in vitro and in vivo. Clinically, high PJA1 expression indicates inferior survival and poor clinical efficacy of TPF IC in nasopharyngeal carcinoma patients. Our study emphasizes the essential role of E3 ligases in regulating chemoresistance and provides therapeutic strategies for nasopharyngeal carcinoma based on targeting the ubiquitin-proteasome system.
Topics: Humans; Docetaxel; Drug Resistance, Neoplasm; Nasopharyngeal Carcinoma; Cell Line, Tumor; Nasopharyngeal Neoplasms; Pyroptosis; Ubiquitination; Animals; Ubiquitin-Protein Ligases; Mice; Mice, Nude; Female; Dynamins; Reactive Oxygen Species; Phosphoprotein Phosphatases; Male; Xenograft Model Antitumor Assays; Mice, Inbred BALB C; Antineoplastic Agents; Phosphorylation; Mitochondrial Proteins; Fluorouracil; Gene Expression Regulation, Neoplastic; Mitochondria; Cisplatin; Middle Aged; Gasdermins
PubMed: 38906860
DOI: 10.1038/s41467-024-49675-2 -
Scientific Reports Jun 2024Increasing evidence supports the hypothesis that cancer progression is under mitochondrial control. Mitochondrial fission plays a pivotal role in the maintenance of...
Increasing evidence supports the hypothesis that cancer progression is under mitochondrial control. Mitochondrial fission plays a pivotal role in the maintenance of cancer cell homeostasis. The inhibition of DRP1, the main regulator of mitochondrial fission, with the mitochondrial division inhibitor (mdivi-1) had been associated with cancer cell sensitivity to chemotherapeutics and decrease proliferation. Here, using breast cancer cells we find that mdivi-1 induces the detachment of the cells, leading to a bulk of floating cells that conserved their viability. Despite a decrease in their proliferative and clonogenic capabilities, these floating cells maintain the capacity to re-adhere upon re-seeding and retain their migratory and invasive potential. Interestingly, the cell detachment induced by mdivi-1 is independent of DRP1 but relies on inhibition of mitochondrial complex I. Furthermore, mdivi-1 induces cell detachment rely on glucose and the pentose phosphate pathway. Our data evidence a novel DRP1-independent effect of mdivi-1 in the attachment of cancer cells. The generation of floating viable cells restricts the use of mdivi-1 as a therapeutic agent and demonstrates that mdivi-1 effect on cancer cells are more complex than anticipated.
Topics: Humans; Dynamins; Breast Neoplasms; Female; Extracellular Matrix; Cell Line, Tumor; Quinazolinones; Mitochondrial Dynamics; Cell Adhesion; Cell Movement; Cell Survival; Cell Proliferation; Mitochondria
PubMed: 38898058
DOI: 10.1038/s41598-024-64228-9 -
Scientific Reports Jun 2024Mesoscale physics bridges the gap between the microscopic degrees of freedom of a system and its large-scale continuous behavior and highlights the role of a few key...
Mesoscale physics bridges the gap between the microscopic degrees of freedom of a system and its large-scale continuous behavior and highlights the role of a few key quantities in complex and multiscale phenomena, like dynamin-driven fission of lipid membranes. The dynamin protein wraps the neck formed during clathrin-mediated endocytosis, for instance, and constricts it until severing occurs. Although ubiquitous and fundamental for life, the cooperation between the GTP-consuming conformational changes within the protein and the full-scale response of the underlying lipid substrate is yet to be unraveled. In this work, we build an effective mesoscopic model from constriction to fission of lipid tubules based on continuum membrane elasticity and implicitly accounting for ratchet-like power strokes of dynamins. Localization of the fission event, the overall geometry, and the energy expenditure we predict comply with the major experimental findings. This bolsters the idea that a continuous picture emerges soon enough to relate dynamin polymerization length and membrane rigidity and tension with the optimal pathway to fission. We therefore suggest that dynamins found in in vivo processes may optimize their structure accordingly. Ultimately, we shed light on real-time conductance measurements available in literature and predict the fission time dependency on elastic parameters.
Topics: Dynamins; Elasticity; Endocytosis; Membrane Lipids; Lipid Bilayers
PubMed: 38890460
DOI: 10.1038/s41598-024-64685-2 -
Nature Communications Jun 2024Chlamydia invasion of epithelial cells is a pathogen-driven process involving two functionally distinct effectors - TarP and TmeA. They collaborate to promote robust...
Chlamydia invasion of epithelial cells is a pathogen-driven process involving two functionally distinct effectors - TarP and TmeA. They collaborate to promote robust actin dynamics at sites of entry. Here, we extend studies on the molecular mechanism of invasion by implicating the host GTPase dynamin 2 (Dyn2) in the completion of pathogen uptake. Importantly, Dyn2 function is modulated by TarP and TmeA at the levels of recruitment and activation through oligomerization, respectively. TarP-dependent recruitment requires phosphatidylinositol 3-kinase and the small GTPase Rac1, while TmeA has a post-recruitment role related to Dyn2 oligomerization. This is based on the rescue of invasion duration and efficiency in the absence of TmeA by the Dyn2 oligomer-stabilizing small molecule activator Ryngo 1-23. Notably, Dyn2 also regulated turnover of TarP- and TmeA-associated actin networks, with disrupted Dyn2 function resulting in aberrant turnover dynamics, thus establishing the interdependent functional relationship between Dyn2 and the effectors TarP and TmeA.
Topics: Chlamydia trachomatis; Humans; Dynamin II; HeLa Cells; Actins; rac1 GTP-Binding Protein; Bacterial Proteins; Chlamydia Infections; Host-Pathogen Interactions; Epithelial Cells
PubMed: 38858371
DOI: 10.1038/s41467-024-49350-6 -
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 -
Biomedicine & Pharmacotherapy =... Jul 2024The roles and mechanisms of A-kinase anchoring protein 1 (AKAP1) in vascular smooth muscle cell (VSMC) phenotypic modulation and neointima formation are currently...
The roles and mechanisms of A-kinase anchoring protein 1 (AKAP1) in vascular smooth muscle cell (VSMC) phenotypic modulation and neointima formation are currently unknown. AKAP1 is a mitochondrial PKA-anchored protein and maintains mitochondrial homeostasis. This study aimed to investigate how AKAP1/PKA signaling plays a protective role in inhibiting VSMC phenotypic transformation and neointima formation by regulating mitochondrial fission. The results showed that both PDGF-BB treatment and balloon injury reduced the transcription, expression, and mitochondrial anchoring of AKAP1. In vitro, the overexpression of AKAP1 significantly inhibited PDGF-BB mediated VSMC proliferation and migration, whereas AKAP1 knockdown further aggravated VSMC phenotypic transformation. Additionally, in the balloon injury model in vivo, AKAP1 overexpression reduced neointima formation, the muscle fiber area ratio, and rat VSMC proliferation and migration. Furthermore, PDGF-BB and balloon injury inhibited Drp1 phosphorylation at Ser637 and promoted Drp1 activity and mitochondrial midzone fission; AKAP1 overexpression reversed these effects. AKAP1 overexpression also inhibited the distribution of mitochondria at the plasma membrane and the reduction of PKARIIβ expression induced by PDGF-BB, as evidenced by an increase in mitochondria-plasma membrane distance as well as PKARIIβ protein levels. Moreover, the PKA agonist promoted Drp1 phosphorylation (Ser637) and inhibited PDGF-BB-mediated mitochondrial fission, cell proliferation, and migration. The PKA antagonist reversed the increase in Drp1 phosphorylation (Ser637) and the decline in mitochondrial midzone fission and VSMC phenotypic transformation caused by AKAP1 overexpression. The results of this study reveal that AKAP1 protects VSMCs against phenotypic modulation by improving Drp1 phosphorylation at Ser637 through PKA and inhibiting mitochondrial fission, thereby preventing neointima formation.
Topics: Animals; A Kinase Anchor Proteins; Mitochondrial Dynamics; Muscle, Smooth, Vascular; Neointima; Dynamins; Rats, Sprague-Dawley; Cell Proliferation; Male; Rats; Phenotype; Myocytes, Smooth Muscle; Becaplermin; Cell Movement; Signal Transduction; Cyclic AMP-Dependent Protein Kinases; Phosphorylation; Cells, Cultured
PubMed: 38850669
DOI: 10.1016/j.biopha.2024.116858 -
Redox Biology Jul 2024The dynamic regulation of mitochondria through fission and fusion is essential for maintaining cellular homeostasis. In this study, we discovered a role of...
The dynamic regulation of mitochondria through fission and fusion is essential for maintaining cellular homeostasis. In this study, we discovered a role of coactivator-associated arginine methyltransferase 1 (CARM1) in mitochondrial dynamics. CARM1 methylates specific residues (R403 and R634) on dynamin-related protein 1 (DRP1). Methylated DRP1 interacts with mitochondrial fission factor (Mff) and forms self-assembly on the outer mitochondrial membrane, thereby triggering fission, reducing oxygen consumption, and increasing reactive oxygen species (ROS) production. This sets in motion a feedback loop that facilitates the translocation of CARM1 from the nucleus to the cytoplasm, enhancing DRP1 methylation and ROS production through mitochondrial fragmentation. Consequently, ROS reinforces the CARM1-DRP1-ROS axis, resulting in cellular senescence. Depletion of CARM1 or DRP1 impedes cellular senescence by reducing ROS accumulation. The uncovering of the above-described mechanism fills a missing piece in the vicious cycle of ROS-induced senescence and contributes to a better understanding of the aging process.
Topics: Mitochondrial Dynamics; Dynamins; Protein-Arginine N-Methyltransferases; Humans; Reactive Oxygen Species; Methylation; Cytoplasm; Cellular Senescence; Mitochondria; Mitochondrial Proteins; Membrane Proteins
PubMed: 38838552
DOI: 10.1016/j.redox.2024.103212 -
Life Science Alliance Aug 2024In cells, mitochondria undergo constant fusion and fission. An essential factor for fission is the mammalian dynamin-related protein 1 (Drp1). Dysregulation of Drp1 is...
In cells, mitochondria undergo constant fusion and fission. An essential factor for fission is the mammalian dynamin-related protein 1 (Drp1). Dysregulation of Drp1 is associated with neurodegenerative diseases including Parkinson's, cardiovascular diseases and cancer, making Drp1 a pivotal biomarker for monitoring mitochondrial status and potential pathophysiological conditions. Here, we developed nanobodies (Nbs) as versatile binding molecules for proteomics, advanced microscopy and live cell imaging of Drp1. To specifically enrich endogenous Drp1 with interacting proteins for proteomics, we functionalized high-affinity Nbs into advanced capture matrices. Furthermore, we detected Drp1 by bivalent Nbs combined with site-directed fluorophore labelling in super-resolution STORM microscopy. For real-time imaging of Drp1, we intracellularly expressed fluorescently labelled Nbs, so-called chromobodies (Cbs). To improve the signal-to-noise ratio, we further converted Cbs into a "turnover-accelerated" format. With these imaging probes, we visualized the dynamics of endogenous Drp1 upon compound-induced mitochondrial fission in living cells. Considering the wide range of research applications, the presented Nb toolset will open up new possibilities for advanced functional studies of Drp1 in disease-relevant models.
Topics: Dynamins; Mitochondrial Dynamics; Humans; Single-Domain Antibodies; Mitochondria; Proteomics; Animals; Protein Binding; HeLa Cells; Mitochondrial Proteins
PubMed: 38816213
DOI: 10.26508/lsa.202402608