bims-mitdyn Biomed News
on Mitochondrial dynamics: mechanisms
Issue of 2023–11–05
sixteen papers selected by
Edmond Chan, Queen’s University, School of Medicine
  1. Autoregulatory control of mitochondrial glutathione homeostasis.
  2. UNC-49 is a redox-sensitive GABAA receptor that regulates the mitochondrial unfolded protein response cell nonautonomously.
  3. DIAPH1-MFN2 interaction regulates mitochondria-SR/ER contact and modulates ischemic/hypoxic stress.
  4. A human mitofusin 2 mutation can cause mitophagic cardiomyopathy.
  5. Regulatory T cells shield muscle mitochondria from interferon-γ-mediated damage to promote the beneficial effects of exercise.
  6. LPGAT1 controls MEGDEL syndrome by coupling phosphatidylglycerol remodeling with mitochondrial transport.
  7. New roles of LPGAT1: From mitochondrial import of phosphatidylglycerol to MEGDEL disease.
  8. MUC1-C integrates aerobic glycolysis with suppression of oxidative phosphorylation in triple-negative breast cancer stem cells.
  9. RCCD1 promotes breast carcinogenesis through regulating hypoxia-associated mitochondrial homeostasis.
  10. Mitochondrial regulation in stem cells.
  11. Mitochondrial complexome and import network.
  12. Super-resolution microscopy: Insights into mitochondria-lysosome crosstalk in health and disease.
  13. The nonstructural protein 1 of respiratory syncytial virus hijacks host mitophagy as a novel mitophagy receptor to evade the type I IFN response in HEp-2 cells.
  14. The mechanisms and roles of mitochondrial dynamics in C. elegans.
  15. Activated Drp1 Initiates the Formation of Endoplasmic Reticulum-Mitochondrial Contacts via Shrm4-Mediated Actin Bundling.
  16. A practical perspective on how to develop, implement, execute, and reproduce high-resolution respirometry experiments: The physiologist's guide to an Oroboros O2k.
  1. Science. 2023 Nov 02. eadf4154
    Autoregulatory control of mitochondrial glutathione homeostasis.
    Yuyang Liu, Shanshan Liu, Anju Tomar, Frederick S Yen, Gokhan Unlu, Nathalie Ropek, Ross A Weber, Ying Wang, Artem Khan, Mark Gad, Junhui Peng, Erdem Terzi, Hanan Alwaseem, Alexandra E Pagano, Søren Heissel, Henrik Molina, Benjamin Allwein, Timothy C Kenny, Richard L Possemato, Li Zhao, Richard K Hite, Ekaterina V Vinogradova, Sheref S Mansy, Kıvanç Birsoy.
      Mitochondria must maintain adequate amounts of metabolites for protective and biosynthetic functions. However, how mitochondria sense the abundance of metabolites and regulate metabolic homeostasis is not well understood. We focused on glutathione (GSH), a critical redox metabolite in mitochondria and identified a feedback mechanism that controls its abundance through the mitochondrial GSH transporter, SLC25A39. Under physiological conditions, SLC25A39 is rapidly degraded by a mitochondrial protease, AFG3L2. Depletion of GSH dissociates AFG3L2 from SLC25A39, causing a compensatory increase in mitochondrial GSH uptake. Genetic and proteomic analysis identified a putative iron-sulfur cluster in the matrix-facing loop of SLC25A39 to be essential for this regulation, coupling mitochondrial iron homeostasis to GSH import. Altogether, our work revealed a paradigm for the autoregulatory control of metabolic homeostasis in organelles.
    DOI:  https://doi.org/10.1126/science.adf4154
  2. Sci Adv. 2023 11 03. 9(44): eadh2584
    UNC-49 is a redox-sensitive GABAA receptor that regulates the mitochondrial unfolded protein response cell nonautonomously.
    Franziska Pohl, Allison L Germann, Jack Mao, Sydney Hou, Bayode Bakare, Paul Kong Thoo Lin, Kyari Yates, Michael L Nonet, Gustav Akk, Kerry Kornfeld, Jason M Held.
      The γ-aminobutyric acid-mediated (GABAergic) system participates in many aspects of organismal physiology and disease, including proteostasis, neuronal dysfunction, and life-span extension. Many of these phenotypes are also regulated by reactive oxygen species (ROS), but the redox mechanisms linking the GABAergic system to these phenotypes are not well defined. Here, we report that GABAergic redox signaling cell nonautonomously activates many stress response pathways in Caenorhabditis elegans and enhances vulnerability to proteostasis disease in the absence of oxidative stress. Cell nonautonomous redox activation of the mitochondrial unfolded protein response (mitoUPR) proteostasis network requires UNC-49, a GABAA receptor that we show is activated by hydrogen peroxide. MitoUPR induction by a spinocerebellar ataxia type 3 (SCA3) C. elegans neurodegenerative disease model was similarly dependent on UNC-49 in C. elegans. These results demonstrate a multi-tissue paradigm for redox signaling in the GABAergic system that is transduced via a GABAA receptor to function in cell nonautonomous regulation of health, proteostasis, and disease.
    DOI:  https://doi.org/10.1126/sciadv.adh2584
  3. Nat Commun. 2023 Oct 30. 14(1): 6900
    DIAPH1-MFN2 interaction regulates mitochondria-SR/ER contact and modulates ischemic/hypoxic stress.
    Gautham Yepuri, Lisa M Ramirez, Gregory G Theophall, Sergei V Reverdatto, Nosirudeen Quadri, Syed Nurul Hasan, Lei Bu, Devi Thiagarajan, Robin Wilson, Raquel López Díez, Paul F Gugger, Kaamashri Mangar, Navneet Narula, Stuart D Katz, Boyan Zhou, Huilin Li, Aleksandr B Stotland, Roberta A Gottlieb, Ann Marie Schmidt, Alexander Shekhtman, Ravichandran Ramasamy.
      Inter-organelle contact and communication between mitochondria and sarco/endoplasmic reticulum (SR/ER) maintain cellular homeostasis and are profoundly disturbed during tissue ischemia. We tested the hypothesis that the formin Diaphanous-1 (DIAPH1), which regulates actin dynamics, signal transduction and metabolic functions, contributes to these processes. We demonstrate that DIAPH1 interacts directly with Mitofusin-2 (MFN2) to shorten mitochondria-SR/ER distance, thereby enhancing mitochondria-ER contact in cells including cardiomyocytes, endothelial cells and macrophages. Solution structure studies affirm the interaction between the Diaphanous Inhibitory Domain and the cytosolic GTPase domain of MFN2. In male rodent and human cardiomyocytes, DIAPH1-MFN2 interaction regulates mitochondrial turnover, mitophagy, and oxidative stress. Introduction of synthetic linker construct, which shorten the mitochondria-SR/ER distance, mitigated the molecular and functional benefits of DIAPH1 silencing in ischemia. This work establishes fundamental roles for DIAPH1-MFN2 interaction in the regulation of mitochondria-SR/ER contact networks. We propose that targeting pathways that regulate DIAPH1-MFN2 interactions may facilitate recovery from tissue ischemia.
    DOI:  https://doi.org/10.1038/s41467-023-42521-x
  4. Elife. 2023 Nov 01. pii: e84235. [Epub ahead of print]12
    A human mitofusin 2 mutation can cause mitophagic cardiomyopathy.
    Antonietta Franco, Jiajia Li, Daniel P Kelly, Ray E Hershberger, Ali J Marian, Renate M Lewis, Moshi Song, Xiawei Dang, Alina D Schmidt, Mary E Mathyer, John R Edwards, Cristina de Guzman Strong, Gerald W Dorn.
      Cardiac muscle has the highest mitochondrial density of any human tissue, but mitochondrial dysfunction is not a recognized cause of isolated cardiomyopathy. Here, we determined that the rare mitofusin (MFN) 2 R400Q mutation is 15-20× over-represented in clinical cardiomyopathy, whereas this specific mutation is not reported as a cause of MFN2 mutant-induced peripheral neuropathy, Charcot-Marie-Tooth disease type 2A (CMT2A). Accordingly, we interrogated the enzymatic, biophysical, and functional characteristics of MFN2 Q400 versus wild-type and CMT2A-causing MFN2 mutants. All MFN2 mutants had impaired mitochondrial fusion, the canonical MFN2 function. Compared to MFN2 T105M that lacked catalytic GTPase activity and exhibited normal activation-induced changes in conformation, MFN2 R400Q and M376A had normal GTPase activity with impaired conformational shifting. MFN2 R400Q did not suppress mitochondrial motility, provoke mitochondrial depolarization, or dominantly suppress mitochondrial respiration like MFN2 T105M. By contrast to MFN2 T105M and M376A, MFN2 R400Q was uniquely defective in recruiting Parkin to mitochondria. CRISPR editing of the R400Q mutation into the mouse Mfn2 gene induced perinatal cardiomyopathy with no other organ involvement; knock-in of Mfn2 T105M or M376V did not affect the heart. RNA sequencing and metabolomics of cardiomyopathic Mfn2 Q/Q400 hearts revealed signature abnormalities recapitulating experimental mitophagic cardiomyopathy. Indeed, cultured cardiomyoblasts and in vivo cardiomyocytes expressing MFN2 Q400 had mitophagy defects with increased sensitivity to doxorubicin. MFN2 R400Q is the first known natural mitophagy-defective MFN2 mutant. Its unique profile of dysfunction evokes mitophagic cardiomyopathy, suggesting a mechanism for enrichment in clinical cardiomyopathy.
    Keywords:  cardiomyopathy; developmental biology; heart; mitochondria; mitofusins; mouse
    DOI:  https://doi.org/10.7554/eLife.84235
  5. Sci Immunol. 2023 Nov 03. 8(89): eadi5377
    Regulatory T cells shield muscle mitochondria from interferon-γ-mediated damage to promote the beneficial effects of exercise.
    P Kent Langston, Yizhi Sun, Birgitta A Ryback, Amber L Mueller, Bruce M Spiegelman, Christophe Benoist, Diane Mathis.
      Exercise enhances physical performance and reduces the risk of many disorders such as cardiovascular disease, type 2 diabetes, dementia, and cancer. Exercise characteristically incites an inflammatory response, notably in skeletal muscles. Although some effector mechanisms have been identified, regulatory elements activated in response to exercise remain obscure. Here, we have addressed the roles of Foxp3+CD4+ regulatory T cells (Tregs) in the healthful activities of exercise via immunologic, transcriptomic, histologic, metabolic, and biochemical analyses of acute and chronic exercise models in mice. Exercise rapidly induced expansion of the muscle Treg compartment, thereby guarding against overexuberant production of interferon-γ and consequent metabolic disruptions, particularly mitochondrial aberrancies. The performance-enhancing effects of exercise training were dampened in the absence of Tregs. Thus, exercise is a natural Treg booster with therapeutic potential in disease and aging contexts.
    DOI:  https://doi.org/10.1126/sciimmunol.adi5377
  6. Cell Rep. 2023 Nov 01. pii: S2211-1247(23)01226-3. [Epub ahead of print]42(11): 113214
    LPGAT1 controls MEGDEL syndrome by coupling phosphatidylglycerol remodeling with mitochondrial transport.
    Haoran Sun, Jun Zhang, Qianqian Ye, Ting Jiang, Xueling Liu, Xiaoyang Zhang, Fanyu Zeng, Jie Li, Yue Zheng, Xianlin Han, Chuan Su, Yuguang Shi.
      Phosphatidylglycerol (PG) is a mitochondrial phospholipid required for mitochondrial cristae structure and cardiolipin synthesis. PG must be remodeled to its mature form at the endoplasmic reticulum (ER) after mitochondrial biosynthesis to achieve its biological functions. Defective PG remodeling causes MEGDEL (non-alcohol fatty liver disease and 3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-like) syndrome through poorly defined mechanisms. Here, we identify LPGAT1, an acyltransferase that catalyzes PG remodeling, as a candidate gene for MEGDEL syndrome. We show that PG remodeling by LPGAT1 at the ER is closely coordinated with mitochondrial transport through interaction with the prohibitin/TIMM14 mitochondrial import motor. Accordingly, ablation of LPGAT1 or TIMM14 not only causes aberrant fatty acyl compositions but also ER retention of newly remodeled PG, leading to profound loss in mitochondrial crista structure and respiration. Consequently, genetic deletion of the LPGAT1 in mice leads to cardinal features of MEGDEL syndrome, including 3-methylglutaconic aciduria, deafness, dilated cardiomyopathy, and premature death, which are highly reminiscent of those caused by TIMM14 mutations in humans.
    Keywords:  CP: Cell biology; LPGAT1; MEGDEL syndrome; mitochondrial dysfunction; phosphatidylglycerol; prohibitin/TIM complex
    DOI:  https://doi.org/10.1016/j.celrep.2023.113214
  7. Cell Rep. 2023 Nov 01. pii: S2211-1247(23)01388-8. [Epub ahead of print]42(11): 113376
    New roles of LPGAT1: From mitochondrial import of phosphatidylglycerol to MEGDEL disease.
    Vera Filipa Monteiro-Cardoso, Francesca Giordano.
      Dysregulation of mitochondrial lipidome is associated with several human pathologies. Sun et al.1 show that LPGAT1 cooperates with TIMM14 to regulate phosphatidylglycerol transport from the endoplasmic reticulum to the mitochondria, and uncover the involvement of LPGAT1 deficiency in MEGDEL syndrome.
    DOI:  https://doi.org/10.1016/j.celrep.2023.113376
  8. iScience. 2023 Nov 17. 26(11): 108168
    MUC1-C integrates aerobic glycolysis with suppression of oxidative phosphorylation in triple-negative breast cancer stem cells.
    Nami Yamashita, Henry Withers, Yoshihiro Morimoto, Atrayee Bhattacharya, Naoki Haratake, Tatsuaki Daimon, Atsushi Fushimi, Ayako Nakashoji, Aaron R Thorner, Emily Isenhart, Spencer Rosario, Mark D Long, Donald Kufe.
      Activation of the MUC1-C protein promotes lineage plasticity, epigenetic reprogramming, and the cancer stem cell (CSC) state. The present studies performed on enriched populations of triple-negative breast cancer (TNBC) CSCs demonstrate that MUC1-C is essential for integrating activation of glycolytic pathway genes with self-renewal and tumorigenicity. MUC1-C further integrates the glycolytic pathway with suppression of mitochondrial DNA (mtDNA) genes encoding components of mitochondrial Complexes I-V. The repression of mtDNA genes is explained by MUC1-C-mediated (i) downregulation of the mitochondrial transcription factor A (TFAM) required for mtDNA transcription and (ii) induction of the mitochondrial transcription termination factor 3 (mTERF3). In support of pathogenesis that suppresses mitochondrial ROS production, targeting MUC1-C increases (i) mtDNA gene transcription, (ii) superoxide levels, and (iii) loss of self-renewal capacity. These findings and scRNA-seq analysis of CSC subpopulations indicate that MUC1-C regulates self-renewal and redox balance by integrating activation of glycolysis with suppression of oxidative phosphorylation.
    Keywords:  Cell biology; Molecular biology; Omics; Transcriptomics
    DOI:  https://doi.org/10.1016/j.isci.2023.108168
  9. Oncogene. 2023 Oct 31.
    RCCD1 promotes breast carcinogenesis through regulating hypoxia-associated mitochondrial homeostasis.
    Yani Peng, Xiaoping Liu, Xinhua Liu, Xiao Cheng, Lu Xia, Leyi Qin, Sudun Guan, Yue Wang, Xiaodi Wu, Jiajing Wu, Dong Yan, Jianying Liu, Yu Zhang, Luyang Sun, Jing Liang, Yongfeng Shang.
      Regulator of chromosome condensation domain-containing protein 1 (RCCD1), previously reported as a partner of histone H3K36 demethylase KDM8 involved in chromosome segregation, has been identified as a potential driver for breast cancer in a recent transcriptome-wide association study. We report here that, unexpectedly, RCCD1 is also localized in mitochondria. We show that RCCD1 resides in the mitochondrial matrix, where it interacts with the mitochondrial contact site/cristae organizing system (MICOS) and mitochondrial DNA (mtDNA) to regulate mtDNA transcription, oxidative phosphorylation, and the production of reactive oxygen species. Interestingly, RCCD1 is upregulated under hypoxic conditions, leading to decreased generation of reactive oxygen species and alleviated apoptosis favoring cancer cell survival. We show that RCCD1 promotes breast cancer cell proliferation in vitro and accelerates breast tumor growth in vivo. Indeed, RCCD1 is overexpressed in breast carcinomas, and its level of expression is associated with aggressive breast cancer phenotypes and poor patient survival. Our study reveals an additional dimension of RCCD1 functionality in regulating mitochondrial homeostasis, whose dysregulation inflicts pathologic states such as breast cancer.
    DOI:  https://doi.org/10.1038/s41388-023-02877-2
  10. Trends Cell Biol. 2023 Oct 31. pii: S0962-8924(23)00207-6. [Epub ahead of print]
    Mitochondrial regulation in stem cells.
    Yifei Wang, Marine Barthez, Danica Chen.
      Stem cells persist throughout the lifespan to repair and regenerate tissues due to their unique ability to self-renew and differentiate. Here we reflect on the recent discoveries in stem cells that highlight a mitochondrial metabolic checkpoint at the restriction point of the stem cell cycle. Mitochondrial activation supports stem cell proliferation and differentiation by providing energy supply and metabolites as signaling molecules. Concomitant mitochondrial stress can lead to loss of stem cell self-renewal and requires the surveillance of various mitochondrial quality control mechanisms. During aging, a mitochondrial protective program mediated by several sirtuins becomes dysregulated and can be targeted to reverse stem cell aging and tissue degeneration, giving hope for targeting the mitochondrial metabolic checkpoint for treating tissue degenerative diseases.
    Keywords:  NAD; NLRP3; SIRT2; SIRT3; SIRT7; aging
    DOI:  https://doi.org/10.1016/j.tcb.2023.10.003
  11. Trends Cell Biol. 2023 Oct 30. pii: S0962-8924(23)00208-8. [Epub ahead of print]
    Mitochondrial complexome and import network.
    Fabian den Brave, Uwe Schulte, Bernd Fakler, Nikolaus Pfanner, Thomas Becker.
      Mitochondria perform crucial functions in cellular metabolism, protein and lipid biogenesis, quality control, and signaling. The systematic analysis of protein complexes and interaction networks provided exciting insights into the structural and functional organization of mitochondria. Most mitochondrial proteins do not act as independent units, but are interconnected by stable or dynamic protein-protein interactions. Protein translocases are responsible for importing precursor proteins into mitochondria and form central elements of several protein interaction networks. These networks include molecular chaperones and quality control factors, metabolite channels and respiratory chain complexes, and membrane and organellar contact sites. Protein translocases link the distinct networks into an overarching network, the mitochondrial import network (MitimNet), to coordinate biogenesis, membrane organization and function of mitochondria.
    Keywords:  cell organelles; energetics; metabolism; mitochondria; morphology; protein assembly; protein networks; protein sorting
    DOI:  https://doi.org/10.1016/j.tcb.2023.10.004
  12. J Cell Biol. 2023 Dec 04. pii: e202305032. [Epub ahead of print]222(12):
    Super-resolution microscopy: Insights into mitochondria-lysosome crosstalk in health and disease.
    Eric D Leisten, Abby C Woods, Yvette C Wong.
      Live super-resolution microscopy has allowed for new insights into recently identified mitochondria-lysosome contact sites, which mediate crosstalk between mitochondria and lysosomes, including co-regulation of Rab7 GTP hydrolysis and Drp1 GTP hydrolysis. Here, we highlight recent findings and future perspectives on this dynamic pathway and its roles in health and disease.
    DOI:  https://doi.org/10.1083/jcb.202305032
  13. mBio. 2023 Nov 01. e0148023
    The nonstructural protein 1 of respiratory syncytial virus hijacks host mitophagy as a novel mitophagy receptor to evade the type I IFN response in HEp-2 cells.
    Jing Cheng, Yutong Wang, Lizheng Yin, Wenzhang Liang, Jing Zhang, Cuiqing Ma, Yu Zhang, Bo Liu, Jiachao Wang, Weiting Zhao, Miao Li, Lin Wei.
      Mitochondria are good targets for viruses to manipulate their hosts. However, it remains obscure whether respiratory syncytial virus (RSV) target mitochondria to suppress the type I interferon (IFN) responses. Here, we show that nonstructural protein 1 (NS1) protein of RSV interacts with Tu translation elongation factor mitochondrial (TUFM), which can lead to its localization in mitochondria and finally induce TUFM-dependent mitophagy and inhibition of IFNβ. Mechanically, NS1-mediated TUFM-dependent mitophagy does not depend on the PINK1-PARKIN pathway and classic mitophagy receptors. Importantly, NS1 may act as a new receptor protein to bridge mitochondria and autophagosomes by interacting with TUFM and LC3B. The LIR motif of NS1 protein is essential for its interaction with LC3B and is of great importance for its mitophagy induction and IFNβ suppression. Finally, NS1-induced TUFM-dependent mitophagy was essential for its attenuated IFNβ response using autophagy-deficient cells and mice. Our study provides a novel mitophagy receptor molecular and a new antiviral option by suppressing antiviral innate immune via targeting TUFM-dependent mitophagy. IMPORTANCE It is a worthy concern for us to understand virus-host interactions which affect progression and prognosis of disease. We demonstrated that the non-structural protein 1 of respiratory syncytial virus (RSV NS1) may act as a novel mitophagy receptor to induce mitophagy by binding LC3B and mitochondrial protein TUFM, and finally dampen interferon (IFN) responses induced by RIG1 and RSV infection. TUFM is beneficial for RSV replication in vivo and vitro. It is new and interesting that RSV NS1 may function as a mitophagy receptor to interact with LC3B. The LIR motif of NS1 protein is essential for its interaction with LC3B. We further confirm that RSV NS1 inhibited IFNβ response and promoted RSV replication in autophagy-dependent mechanisms in vivo and vitro. Our study contributes to understanding virus-host interaction, enriching our insights into RSV pathogenic mechanism and exploiting new antiviral treatments targeting TUFM.
    Keywords:  IFNβ; RSV NS1 protein; TUFM; mitophagy; viral replication
    DOI:  https://doi.org/10.1128/mbio.01480-23
  14. Semin Cell Dev Biol. 2023 Oct 31. pii: S1084-9521(23)00203-3. [Epub ahead of print]
    The mechanisms and roles of mitochondrial dynamics in C. elegans.
    Daniel Campbell, Steven Zuryn.
      If mitochondria are the powerhouses of the cell, then mitochondrial dynamics are the power grid that regulates how that energy output is directed and maintained in response to unique physiological demands. Fission and fusion dynamics are highly regulated processes that fine-tune the mitochondrial networks of cells to enable appropriate responses to intrinsic and extrinsic stimuli, thereby maintaining cellular and organismal homeostasis. These dynamics shape many aspects of an organism's healthspan including development, longevity, stress resistance, immunity, and response to disease. In this review, we discuss the latest findings regarding the mechanisms and roles of mitochondrial dynamics by focussing on the nematode Caenorhabditis elegans. Whole live-animal studies in C. elegans have enabled a true organismal-level understanding of the impact that mitochondrial dynamics play in homeostasis over a lifetime.
    Keywords:  Development; Disease; Fission; Fusion; Longevity; Quality-control
    DOI:  https://doi.org/10.1016/j.semcdb.2023.10.006
  15. Adv Sci (Weinh). 2023 Nov 01. e2304885
    Activated Drp1 Initiates the Formation of Endoplasmic Reticulum-Mitochondrial Contacts via Shrm4-Mediated Actin Bundling.
    Chenyang Duan, Ruixue Liu, Lei Kuang, Zisen Zhang, Dongyao Hou, Danyang Zheng, Xinming Xiang, He Huang, Liangming Liu, Tao Li.
      Excessive mitochondrial fission following ischemia and hypoxia relies on the formation of contacts between the endoplasmic reticulum and mitochondria (ER-Mito); however, the specific mechanisms behind this process remain unclear. Confocal microscopy and time course recording are used to investigate how ischemia and hypoxia affect the activation of dynamin-related protein 1 (Drp1), a protein central to mitochondrial dynamics, ER-Mito interactions, and the consequences of modifying the expression of Drp1, shroom (Shrm) 4, and inverted formin (INF) 2 on ER-Mito contact establishment. Both Drp1 activation and ER-Mito contact initiation cause excessive mitochondrial fission and dysfunction under ischemic-hypoxic conditions. The activated form of Drp1 aids in ER-Mito contact initiation by recruiting Shrm4 and promoting actin bundling between the ER and mitochondria. This process relies on the structural interplay between INF2 and scattered F-actin on the ER. This study uncovers new roles of cytoplasmic Drp1, providing valuable insights for devising strategies to manage mitochondrial imbalances in the context of ischemic-hypoxic injury.
    Keywords:  Drp1; ER-Mito contact; actin bundling; mitochondrial fission; shrm4
    DOI:  https://doi.org/10.1002/advs.202304885
  16. FASEB J. 2023 Dec;37(12): e23280
    A practical perspective on how to develop, implement, execute, and reproduce high-resolution respirometry experiments: The physiologist's guide to an Oroboros O2k.
    Maureen A Walsh, Robert V Musci, Robert A Jacobs, Karyn L Hamilton.
      The development of high-resolution respirometry (HRR) has greatly expanded the analytical scope to study mitochondrial respiratory control relative to specific tissue/cell types across various metabolic states. Specifically, the Oroboros Oxygraph 2000 (O2k) is a common tool for measuring rates of mitochondrial respiration and is the focus of this perspective. The O2k platform is amenable for answering numerous bioenergetic questions. However, inherent variability with HRR-derived data, both within and amongst users, can impede progress in bioenergetics research. Therefore, we advocate for several vital considerations when planning and conducting O2k experiments to ultimately enhance transparency and reproducibility across laboratories. In this perspective, we offer guidance for best practices of mitochondrial preparation, protocol selection, and measures to increase reproducibility. The goal of this perspective is to propagate the use of the O2k, enhance reliability and validity for both new and experienced O2k users, and provide a reference for peer reviewers.
    Keywords:  Oroboros O2k; bioenergetics; isolated mitochondria; mitochondria; permeabilized fibers; protocol development
    DOI:  https://doi.org/10.1096/fj.202301644RR
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