1
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Xu K, Saaoud F, Shao Y, Lu Y, Yang Q, Jiang X, Wang H, Yang X. A new paradigm in intracellular immunology: Mitochondria emerging as leading immune organelles. Redox Biol 2024; 76:103331. [PMID: 39216270 PMCID: PMC11402145 DOI: 10.1016/j.redox.2024.103331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Revised: 08/23/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024] Open
Abstract
Mitochondria, traditionally recognized as cellular 'powerhouses' due to their pivotal role in energy production, have emerged as multifunctional organelles at the intersection of bioenergetics, metabolic signaling, and immunity. However, the understanding of their exact contributions to immunity and inflammation is still developing. This review first introduces the innovative concept of intracellular immunity, emphasizing how mitochondria serve as critical immune signaling hubs. They are instrumental in recognizing and responding to pathogen and danger signals, and in modulating immune responses. We also propose mitochondria as the leading immune organelles, drawing parallels with the broader immune system in their functions of antigen presentation, immune regulation, and immune response. Our comprehensive review explores mitochondrial immune signaling pathways, their therapeutic potential in managing inflammation and chronic diseases, and discusses cutting-edge methodologies for mitochondrial research. Targeting a broad readership of both experts in mitochondrial functions and newcomers to the field, this review sets forth new directions that could transform our understanding of intracellular immunity and the integrated immune functions of intracellular organelles.
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Affiliation(s)
- Keman Xu
- Lemole Center for Integrated Lymphatics and Vascular Research, USA
| | - Fatma Saaoud
- Lemole Center for Integrated Lymphatics and Vascular Research, USA
| | - Ying Shao
- Lemole Center for Integrated Lymphatics and Vascular Research, USA
| | - Yifan Lu
- Lemole Center for Integrated Lymphatics and Vascular Research, USA
| | | | - Xiaohua Jiang
- Lemole Center for Integrated Lymphatics and Vascular Research, USA; Metabolic Disease Research and Thrombosis Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
| | - Hong Wang
- Metabolic Disease Research and Thrombosis Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
| | - Xiaofeng Yang
- Lemole Center for Integrated Lymphatics and Vascular Research, USA; Metabolic Disease Research and Thrombosis Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA.
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2
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Sleigh JN, Mattedi F, Richter S, Annuario E, Ng K, Steinmark IE, Ivanova I, Darabán IL, Joshi PP, Rhymes ER, Awale S, Yahioglu G, Mitchell JC, Suhling K, Schiavo G, Vagnoni A. Age-specific and compartment-dependent changes in mitochondrial homeostasis and cytoplasmic viscosity in mouse peripheral neurons. Aging Cell 2024; 23:e14250. [PMID: 38881280 PMCID: PMC11464114 DOI: 10.1111/acel.14250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/26/2024] [Accepted: 05/20/2024] [Indexed: 06/18/2024] Open
Abstract
Mitochondria are dynamic bioenergetic hubs that become compromised with age. In neurons, declining mitochondrial axonal transport has been associated with reduced cellular health. However, it is still unclear to what extent the decline of mitochondrial transport and function observed during ageing are coupled, and if somal and axonal mitochondria display compartment-specific features that make them more susceptible to the ageing process. It is also not known whether the biophysical state of the cytoplasm, thought to affect many cellular functions, changes with age to impact mitochondrial trafficking and homeostasis. Focusing on the mouse peripheral nervous system, we show that age-dependent decline in mitochondrial trafficking is accompanied by reduction of mitochondrial membrane potential and intramitochondrial viscosity, but not calcium buffering, in both somal and axonal mitochondria. Intriguingly, we observe a specific increase in cytoplasmic viscosity in the neuronal cell body, where mitochondria are most polarised, which correlates with decreased cytoplasmic diffusiveness. Increasing cytoplasmic crowding in the somatic compartment of DRG neurons grown in microfluidic chambers reduces mitochondrial axonal trafficking, suggesting a mechanistic link between the regulation of cytoplasmic viscosity and mitochondrial dynamics. Our work provides a reference for studying the relationship between neuronal mitochondrial homeostasis and the viscoelasticity of the cytoplasm in a compartment-dependent manner during ageing.
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Affiliation(s)
- James N. Sleigh
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease CentreUCL Queen Square Institute of Neurology, University College LondonLondonUK
- UK Dementia Research Institute, University College LondonLondonUK
| | - Francesca Mattedi
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
- Present address:
Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology, University College LondonLondonUK
| | - Sandy Richter
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
- Present address:
Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Emily Annuario
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
| | - Kristal Ng
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
| | | | | | - István L. Darabán
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
| | - Parth P. Joshi
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
- Present address:
Sunderland Medical School, University of SunderlandSunderlandUK
| | - Elena R. Rhymes
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease CentreUCL Queen Square Institute of Neurology, University College LondonLondonUK
- UK Dementia Research Institute, University College LondonLondonUK
| | - Shirwa Awale
- Department of PhysicsKing's College LondonLondonUK
| | - Gokhan Yahioglu
- Antikor Biopharma Ltd, Stevenage Bioscience CatalystStevenageUK
| | - Jacqueline C. Mitchell
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
| | | | - Giampietro Schiavo
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease CentreUCL Queen Square Institute of Neurology, University College LondonLondonUK
- UK Dementia Research Institute, University College LondonLondonUK
| | - Alessio Vagnoni
- Department of Basic and Clinical NeurosciencesMaurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondonUK
- MIA‐PortugalMultidisciplinary Institute of Ageing, University of CoimbraCoimbraPortugal
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3
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Handley S, Anwer AG, Knab A, Bhargava A, Goldys EM. AutoMitoNetwork: Software for analyzing mitochondrial networks in autofluorescence images to enable label-free cell classification. Cytometry A 2024; 105:688-703. [PMID: 39078083 DOI: 10.1002/cyto.a.24889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 07/08/2024] [Accepted: 07/10/2024] [Indexed: 07/31/2024]
Abstract
High-resolution mitochondria imaging in combination with image analysis tools have significantly advanced our understanding of cellular function in health and disease. However, most image analysis tools for mitochondrial studies have been designed to work with fluorescently labeled images only. Additionally, efforts to integrate features describing mitochondrial networks with machine learning techniques for the differentiation of cell types have been limited. Herein, we present AutoMitoNetwork software for image-based assessment of mitochondrial networks in label-free autofluorescence images using a range of interpretable morphological, intensity, and textural features. To demonstrate its utility, we characterized unstained mitochondrial networks in healthy retinal cells and in retinal cells exposed to two types of treatments: rotenone, which directly inhibited mitochondrial respiration and ATP production, and iodoacetic acid, which had a milder impact on mitochondrial networks via the inhibition of anaerobic glycolysis. For both cases, our multi-dimensional feature analysis combined with a support vector machine classifier distinguished between healthy cells and those treated with rotenone or iodoacetic acid. Subtle changes in morphological features were measured including increased fragmentation in the treated retinal cells, pointing to an association with metabolic mechanisms. AutoMitoNetwork opens new options for image-based machine learning in label-free imaging, diagnostics, and mitochondrial disease drug development.
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Affiliation(s)
- Shannon Handley
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), University of New South Wales, Sydney, New South Wales, Australia
- The Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Ayad G Anwer
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), University of New South Wales, Sydney, New South Wales, Australia
- The Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Aline Knab
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), University of New South Wales, Sydney, New South Wales, Australia
- The Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Akanksha Bhargava
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), University of New South Wales, Sydney, New South Wales, Australia
- The Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Ewa M Goldys
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), University of New South Wales, Sydney, New South Wales, Australia
- The Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
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Das R, Maity S, Das P, Kamal IM, Chakrabarti S, Chakrabarti O. CMT2A-linked MFN2 mutation, T206I promotes mitochondrial hyperfusion and predisposes cells towards mitophagy. Mitochondrion 2024; 74:101825. [PMID: 38092249 DOI: 10.1016/j.mito.2023.101825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 12/01/2023] [Accepted: 12/09/2023] [Indexed: 12/21/2023]
Abstract
Mutations in Mitofusin2 (MFN2) associated with the pathology of the debilitating neuropathy Charcot-Marie-Tooth type 2A (CMT2A) are known to alter mitochondrial morphology. Previously, such mutations have been shown to elicit two diametrically opposite phenotypes - while some mutations have been causally linked to enhanced mitochondrial fragmentation, others have been shown to induce hyperfusion. Our study identifies one such MFN2 mutant, T206I that causes mitochondrial hyperfusion. Cells expressing this MFN2 mutant have elongated and interconnected mitochondria. T206I-MFN2 mutation in the GTPase domain increases MFN2 stability and renders cells susceptible to stress. We show that cells expressing T206I-MFN2 have a higher predisposition towards mitophagy under conditions of serum starvation. We also detect increased DRP1 recruitment onto the outer mitochondrial membrane, though the total DRP1 protein level remains unchanged. Here we have characterized a lesser studied CMT2A-linked MFN2 mutant to show that its presence affects mitochondrial morphology and homeostasis.
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Affiliation(s)
- Rajdeep Das
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India; Homi Bhabha National Institute, India
| | - Sebabrata Maity
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India; Homi Bhabha National Institute, India
| | - Palamou Das
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India; Homi Bhabha National Institute, India
| | - Izaz Monir Kamal
- Structural Biology and Bioinformatics Division, CSIR Indian Institute of Chemical Biology, CN 6, Sector V, Salt Lake, Kolkata 700091, India; Academy of Scientific and Innovative Research (AcSIR), Gaziabad, India
| | - Saikat Chakrabarti
- Structural Biology and Bioinformatics Division, CSIR Indian Institute of Chemical Biology, CN 6, Sector V, Salt Lake, Kolkata 700091, India; Academy of Scientific and Innovative Research (AcSIR), Gaziabad, India
| | - Oishee Chakrabarti
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India; Homi Bhabha National Institute, India.
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5
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Agarwala S, Saini M, Parker D, Mitra K. Enrichment of carcinogen-driven "mitochondria-primed" human skin stem cells and their identification using single-cell analyses. STAR Protoc 2023; 4:102545. [PMID: 37690024 PMCID: PMC10500471 DOI: 10.1016/j.xpro.2023.102545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 07/03/2023] [Accepted: 08/07/2023] [Indexed: 09/12/2023] Open
Abstract
Previous work has shown that mitochondria play a critical role in priming stem cells to self-renew and proliferate. Here, we describe a protocol for enriching and identifying the mitochondria-primed stem cells (mpSCs) for their characterization and applications. We describe steps for enriching mpSCs with the environmental carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin in a skin keratinocyte lineage and for identifying mpSCs using single-cell transcriptomics and single-cell microscopy analyses of expression of relevant stem cell markers. For complete details on the use and execution of this protocol, please refer to Spurlock et al.1.
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Affiliation(s)
- Swati Agarwala
- Department of Biology, Trivedi School of BioSciences, Ashoka University, Sonipat, Haryana 131029, India
| | - Mayank Saini
- Department of Biology, Trivedi School of BioSciences, Ashoka University, Sonipat, Haryana 131029, India
| | - Danitra Parker
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Kasturi Mitra
- Department of Biology, Trivedi School of BioSciences, Ashoka University, Sonipat, Haryana 131029, India; Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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6
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Rickard BP, Overchuk M, Chappell VA, Kemal Ruhi M, Sinawang PD, Nguyen Hoang TT, Akin D, Demirci U, Franco W, Fenton SE, Santos JH, Rizvi I. Methods to Evaluate Changes in Mitochondrial Structure and Function in Cancer. Cancers (Basel) 2023; 15:2564. [PMID: 37174030 PMCID: PMC10177605 DOI: 10.3390/cancers15092564] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Mitochondria are regulators of key cellular processes, including energy production and redox homeostasis. Mitochondrial dysfunction is associated with various human diseases, including cancer. Importantly, both structural and functional changes can alter mitochondrial function. Morphologic and quantifiable changes in mitochondria can affect their function and contribute to disease. Structural mitochondrial changes include alterations in cristae morphology, mitochondrial DNA integrity and quantity, and dynamics, such as fission and fusion. Functional parameters related to mitochondrial biology include the production of reactive oxygen species, bioenergetic capacity, calcium retention, and membrane potential. Although these parameters can occur independently of one another, changes in mitochondrial structure and function are often interrelated. Thus, evaluating changes in both mitochondrial structure and function is crucial to understanding the molecular events involved in disease onset and progression. This review focuses on the relationship between alterations in mitochondrial structure and function and cancer, with a particular emphasis on gynecologic malignancies. Selecting methods with tractable parameters may be critical to identifying and targeting mitochondria-related therapeutic options. Methods to measure changes in mitochondrial structure and function, with the associated benefits and limitations, are summarized.
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Affiliation(s)
- Brittany P. Rickard
- Curriculum in Toxicology & Environmental Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Marta Overchuk
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, and North Carolina State University, Raleigh, NC 27695, USA
| | - Vesna A. Chappell
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Mustafa Kemal Ruhi
- Institute of Biomedical Engineering, Boğaziçi University, Istanbul 34684, Turkey
| | - Prima Dewi Sinawang
- Canary Center at Stanford for Cancer Early Detection, Department of Radiology, School of Medicine, Palo Alto, CA 94304, USA
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Tina Thuy Nguyen Hoang
- Department of Biomedical Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Demir Akin
- Canary Center at Stanford for Cancer Early Detection, Department of Radiology, School of Medicine, Palo Alto, CA 94304, USA
- Center for Cancer Nanotechnology Excellence for Translational Diagnostics (CCNE-TD), School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Utkan Demirci
- Canary Center at Stanford for Cancer Early Detection, Department of Radiology, School of Medicine, Palo Alto, CA 94304, USA
| | - Walfre Franco
- Department of Biomedical Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Suzanne E. Fenton
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Janine H. Santos
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Imran Rizvi
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, and North Carolina State University, Raleigh, NC 27695, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
- Center for Environmental Health and Susceptibility, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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7
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Chang YW, Tony Yang T, Chen MC, Liaw YG, Yin CF, Lin-Yan XQ, Huang TY, Hou JT, Hung YH, Hsu CL, Huang HC, Juan HF. Spatial and temporal dynamics of ATP synthase from mitochondria toward the cell surface. Commun Biol 2023; 6:427. [PMID: 37072500 PMCID: PMC10113393 DOI: 10.1038/s42003-023-04785-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 03/30/2023] [Indexed: 04/20/2023] Open
Abstract
Ectopic ATP synthase complex (eATP synthase), located on cancer cell surface, has been reported to possess catalytic activity that facilitates the generation of ATP in the extracellular environment to establish a suitable microenvironment and to be a potential target for cancer therapy. However, the mechanism of intracellular ATP synthase complex transport remains unclear. Using a combination of spatial proteomics, interaction proteomics, and transcriptomics analyses, we find ATP synthase complex is first assembled in the mitochondria and subsequently delivered to the cell surface along the microtubule via the interplay of dynamin-related protein 1 (DRP1) and kinesin family member 5B (KIF5B). We further demonstrate that the mitochondrial membrane fuses to the plasma membrane in turn to anchor ATP syntheses on the cell surface using super-resolution imaging and real-time fusion assay in live cells. Our results provide a blueprint of eATP synthase trafficking and contribute to the understanding of the dynamics of tumor progression.
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Grants
- 109-2221-E-010-012-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- MOST 109-2221-E-010-011-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- MOST 109-2327-B-006-004 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- MOST 109-2320-B-002-017-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- MOST 109-2221-E-002-161-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- NTU-110L8808 Ministry of Education (Ministry of Education, Republic of China (Taiwan))
- NTU-CC-109L104702-2 Ministry of Education (Ministry of Education, Republic of China (Taiwan))
- NTU-110L7103 Ministry of Education (Ministry of Education, Republic of China (Taiwan))
- NTU-111L7107 Ministry of Education (Ministry of Education, Republic of China (Taiwan))
- NTU-CC-112L892102 Ministry of Education (Ministry of Education, Republic of China (Taiwan))
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Affiliation(s)
- Yi-Wen Chang
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - T Tony Yang
- Department of Electrical Engineering, National Taiwan University, Taipei, 106, Taiwan
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, 106, Taiwan
| | - Min-Chun Chen
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Y-Geh Liaw
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Chieh-Fan Yin
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Xiu-Qi Lin-Yan
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Ting-Yu Huang
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Jen-Tzu Hou
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Yi-Hsuan Hung
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
| | - Chia-Lang Hsu
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei, 100, Taiwan
| | - Hsuan-Cheng Huang
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, 112, Taiwan.
| | - Hsueh-Fen Juan
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106, Taiwan.
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, 106, Taiwan.
- Center for Computational and Systems Biology, National Taiwan University, Taipei, 106, Taiwan.
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Santo-Domingo J, Lassueur S, Galindo AN, Alvarez-Illera P, Romero-Sanz S, Caldero-Escudero E, de la Fuente S, Dayon L, Wiederkehr A. SLC25A46 promotes mitochondrial fission and mediates resistance to lipotoxic stress in INS-1E insulin-secreting cells. J Cell Sci 2023; 136:jcs260049. [PMID: 36942724 DOI: 10.1242/jcs.260049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 03/01/2023] [Indexed: 03/23/2023] Open
Abstract
Glucose sensing in pancreatic β-cells depends on oxidative phosphorylation and mitochondria-derived signals that promote insulin secretion. Using mass spectrometry-based phosphoproteomics to search for downstream effectors of glucose-dependent signal transduction in INS-1E insulinoma cells, we identified the outer mitochondrial membrane protein SLC25A46. Under resting glucose concentrations, SLC25A46 was phosphorylated on a pair of threonine residues (T44/T45) and was dephosphorylated in response to glucose-induced Ca2+ signals. Overexpression of SLC25A46 in INS-1E cells caused complete mitochondrial fragmentation, resulting in a mild mitochondrial defect associated with lowered glucose-induced insulin secretion. In contrast, inactivation of the Slc25a46 gene resulted in dramatic mitochondrial hyperfusion, without affecting respiratory activity or insulin secretion. Consequently, SLC25A46 is not essential for metabolism-secretion coupling under normal nutrient conditions. Importantly, insulin-secreting cells lacking SLC25A46 had an exacerbated sensitivity to lipotoxic conditions, undergoing massive apoptosis when exposed to palmitate. Therefore, in addition to its role in mitochondrial dynamics, SLC25A46 plays a role in preventing mitochondria-induced apoptosis in INS-E cells exposed to nutrient stress. By protecting mitochondria, SLC25A46 might help to maintain β-cell mass essential for blood glucose control.
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Affiliation(s)
- Jaime Santo-Domingo
- Department of Cell Biology, Nestlé Institute of Health Sciences, Nestlé Research, CH-1015 Lausanne, Switzerland
- Department of Biochemistry and Molecular Biology, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Faculty of Medicine, 47003 Valladolid, Spain
| | - Steve Lassueur
- Department of Cell Biology, Nestlé Institute of Health Sciences, Nestlé Research, CH-1015 Lausanne, Switzerland
| | - Antonio Núñez Galindo
- Proteomics, Nestlé Institute of Food Safety & Analytical Sciences, Nestlé Research, CH-1015 Lausanne, Switzerland
| | - Pilar Alvarez-Illera
- Department of Biochemistry and Molecular Biology, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Faculty of Medicine, 47003 Valladolid, Spain
| | - Silvia Romero-Sanz
- Department of Biochemistry and Molecular Biology, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Faculty of Medicine, 47003 Valladolid, Spain
| | - Elena Caldero-Escudero
- Department of Biochemistry and Molecular Biology, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Faculty of Medicine, 47003 Valladolid, Spain
| | - Sergio de la Fuente
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Loïc Dayon
- Proteomics, Nestlé Institute of Food Safety & Analytical Sciences, Nestlé Research, CH-1015 Lausanne, Switzerland
- Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Andreas Wiederkehr
- Department of Cell Biology, Nestlé Institute of Health Sciences, Nestlé Research, CH-1015 Lausanne, Switzerland
- Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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9
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Adiga D, Bhat S, Shukla V, Shah HV, Kuthethur R, Chakrabarty S, Kabekkodu SP. Double C-2 like domain beta (DOC2B) induces calcium dependent oxidative stress to promote lipotoxicity and mitochondrial dysfunction for its tumor suppressive function. Free Radic Biol Med 2023; 201:1-13. [PMID: 36913987 DOI: 10.1016/j.freeradbiomed.2023.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/07/2023] [Accepted: 03/07/2023] [Indexed: 03/13/2023]
Abstract
Mitochondria are biosynthetic and bioenergetic organelles that regulate many biological processes, including metabolism, oxidative stress, and cell death. Cervical cancer (CC) cells show impairments in mitochondrial structure and function and are linked with cancer progression. DOC2B is a tumor suppressor with anti-proliferative, anti-migratory, anti-invasive, and anti-metastatic function in CC. For the first time, we demonstrated the role of the DOC2B-mitochondrial axis with tumor growth regulatory functions in CC. We used DOC2B overexpression and knockdown model systems to show that DOC2B is localized to mitochondria and induces Ca2+-mediated lipotoxicity. DOC2B expression induced mitochondrial morphological changes with the subsequent reduction in mitochondrial DNA copy number, mitochondrial mass, and mitochondrial membrane potential. Intracellular and mitochondrial Ca2+, intracellular O.-2, and ATP levels were substantially elevated in the presence of DOC2B. DOC2B manipulation reduced glucose uptake, lactate production, and mitochondrial complex-IV activity. The presence of DOC2B significantly reduced the proteins associated with mitochondrial structure and biogenesis with the concomitant activation of AMPK signaling. Augmented lipid peroxidation (LPO) in the presence of DOC2B was a Ca2+-dependent process. Our findings demonstrated that DOC2B promotes lipid accumulation, oxidative stress, and LPO through intracellular Ca2+ overload, which may contribute to mitochondrial dysfunction and tumor-suppressive properties of DOC2B. We propose that the DOC2B-Ca2+-oxidative stress-LPO-mitochondrial axis could be targeted for confining CC. Further, the induction of lipotoxicity in tumor cells by activating DOC2B could serve as a novel therapeutic approach in CC.
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Affiliation(s)
- Divya Adiga
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Samatha Bhat
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Vaibhav Shukla
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Henil Vinit Shah
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Raviprasad Kuthethur
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Sanjiban Chakrabarty
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Shama Prasada Kabekkodu
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India.
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10
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Zheng Y, Ye Z, Xiao Y. Subtle Structural Translation Magically Modulates the Super-Resolution Imaging of Self-Blinking Rhodamines. Anal Chem 2023; 95:4172-4179. [PMID: 36787420 DOI: 10.1021/acs.analchem.2c05298] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The evolution of super-resolution imaging techniques is benefited from the ongoing competition for optimal rhodamine fluorophores. Yet, it seems blind to construct the desired rhodamine molecule matching the imaging need without the knowledge on imaging impact of even the minimum structural translation. Herein, we have designed a pair of self-blinking sulforhodamines (STMR and SRhB) with the bare distinction of methyl or ethyl substituents and engineered them with Halo protein ligands. Although the two possess similar spectral properties (λab, λfl, ϕ, etc.), they demonstrated unique single-molecule characteristics preferring to individual imaging applications. Experimentally, STMR with high emissive rates was qualified for imaging structures with rapid dynamics (endoplasmic reticulum, and mitochondria), and SRhB with prolonged on-times and photostability was suited for relatively "static" nuclei and microtubules. Using this new knowledge, the mitochondrial morphology during apoptosis and ferroptosis was first super-resolved by STMR. Our study highlights the significance of even the smallest structural modification to the modulation of super-resolution imaging performance and would provide insights for future fluorophore design.
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Affiliation(s)
- Ying Zheng
- State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials Oriented Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Zhiwei Ye
- State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials Oriented Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Yi Xiao
- State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials Oriented Chemical Engineering, Dalian University of Technology, Dalian 116024, China
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11
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Li SJ, Liu H, Wu FF, Feng DY, Zhang S, Zheng J, Wang L, Tian F, Yang YL, Wang YY. Meshed neuronal mitochondrial networks empowered by AI-powered classifiers and immersive VR reconstruction. Front Neurosci 2023; 17:1059965. [PMID: 36816131 PMCID: PMC9932543 DOI: 10.3389/fnins.2023.1059965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 01/16/2023] [Indexed: 02/05/2023] Open
Abstract
Mitochondrial networks are defined as a continuous matrix lumen, but the morphological feature of neuronal mitochondrial networks is not clear due to the lack of suitable analysis techniques. The aim of the present study is to develop a framework to capture and analyze the neuronal mitochondrial networks by using 4-step process composed of 2D and 3D observation, primary and secondary virtual reality (VR) analysis, with the help of artificial intelligence (AI)-powered Aivia segmentation an classifiers. In order to fulfill this purpose, we first generated the PCs-Mito-GFP mice, in which green fluorescence protein (GFP) could be expressed on the outer mitochondrial membrane specifically on the cerebellar Purkinje cells (PCs), thus all mitochondria in the giant neuronal soma, complex dendritic arborization trees and long projection axons of Purkinje cells could be easily detected under a laser scanning confocal microscope. The 4-step process resolved the complicated neuronal mitochondrial networks into discrete neuronal mitochondrial meshes. Second, we measured the two parameters of the neuronal mitochondrial meshes, and the results showed that the surface area (μm2) of mitochondrial meshes was the biggest in dendritic trees (45.30 ± 53.21), the smallest in granular-like axons (3.99 ± 1.82), and moderate in soma (27.81 ± 22.22) and silk-like axons (17.50 ± 15.19). These values showed statistically different among different subcellular locations. The volume (μm3) of mitochondrial meshes was the biggest in dendritic trees (9.97 ± 12.34), the smallest in granular-like axons (0.43 ± 0.25), and moderate in soma (6.26 ± 6.46) and silk-like axons (3.52 ± 4.29). These values showed significantly different among different subcellular locations. Finally, we found both the surface area and the volume of mitochondrial meshes in dendritic trees and soma within the Purkinje cells in PCs-Mito-GFP mice after receiving the training with the simulating long-term pilot flight concentrating increased significantly. The precise reconstruction of neuronal mitochondrial networks is extremely laborious, the present 4-step workflow powered by artificial intelligence and virtual reality reconstruction could successfully address these challenges.
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Affiliation(s)
- Shu-Jiao Li
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Teaching Demonstration Center, School of Basic Medicine, Air Force Medical University (Fourth Military Medical University), Xi’an, China
| | - Hui Liu
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Teaching Demonstration Center, School of Basic Medicine, Air Force Medical University (Fourth Military Medical University), Xi’an, China,Department of Human Anatomy, Histology and Embryology, Medical School of Yan’an University, Yan’an, China
| | - Fei-Fei Wu
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Teaching Demonstration Center, School of Basic Medicine, Air Force Medical University (Fourth Military Medical University), Xi’an, China
| | - Da-Yun Feng
- Department of Neurosurgery, Tangdu Hospital, Air Force Medical University (Fourth Military Medical University), Xi’an, China
| | - Shuai Zhang
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Teaching Demonstration Center, School of Basic Medicine, Air Force Medical University (Fourth Military Medical University), Xi’an, China
| | - Jie Zheng
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Teaching Demonstration Center, School of Basic Medicine, Air Force Medical University (Fourth Military Medical University), Xi’an, China,Department of Human Anatomy, Histology and Embryology, Medical School of Yan’an University, Yan’an, China
| | - Lu Wang
- Department of Human Anatomy, Histology and Embryology, Medical School of Yan’an University, Yan’an, China,Lu Wang,
| | - Fei Tian
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Teaching Demonstration Center, School of Basic Medicine, Air Force Medical University (Fourth Military Medical University), Xi’an, China,Fei Tian,
| | - Yan-Ling Yang
- Department of Hepatobiliary Surgery, Xijing Hospital, Air Force Medical University (Fourth Military Medical University), Xi’an, China,Yan-Ling Yang,
| | - Ya-Yun Wang
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Teaching Demonstration Center, School of Basic Medicine, Air Force Medical University (Fourth Military Medical University), Xi’an, China,State Key Laboratory of Military Stomatology, School of Stomatology, Air Force Medical University (Fourth Military Medical University), Xi’an, China,*Correspondence: Ya-Yun Wang, ,
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12
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O’Reilly CL, Miller BF, Lewis TL. Exercise and mitochondrial remodeling to prevent age-related neurodegeneration. J Appl Physiol (1985) 2023; 134:181-189. [PMID: 36519568 PMCID: PMC9829476 DOI: 10.1152/japplphysiol.00611.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Healthy brain activity requires precise ion and energy management creating a strong reliance on mitochondrial function. Age-related neurodegeneration leads to a decline in mitochondrial function and increased oxidative stress, with associated declines in mitochondrial mass, respiration capacity, and respiration efficiency. The interdependent processes of mitochondrial protein turnover and mitochondrial dynamics, known together as mitochondrial remodeling, play essential roles in mitochondrial health and therefore brain function. This mini-review describes the role of mitochondria in neurodegeneration and brain health, current practices for assessing both aspects of mitochondrial remodeling, and how exercise mitigates the adverse effects of aging in the brain. Exercise training elicits functional adaptations to improve brain health, and current literature strongly suggests that mitochondrial remodeling plays a vital role in these positive adaptations. Despite substantial implications that the two aspects of mitochondrial remodeling are interdependent, very few investigations have simultaneously measured mitochondrial dynamics and protein synthesis. An improved understanding of the partnership between mitochondrial protein turnover and mitochondrial dynamics will provide a better understanding of their role in both brain health and disease, as well as how they induce protection following exercise.
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Affiliation(s)
- Colleen L. O’Reilly
- 1Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Benjamin F. Miller
- 1Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma,2Oklahoma City Veterans Association, Oklahoma City, Oklahoma
| | - Tommy L. Lewis
- 1Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
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13
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Basilico B, Palamà IE, D’Amone S, Lauro C, Rosito M, Grieco M, Ratano P, Cordella F, Sanchini C, Di Angelantonio S, Ragozzino D, Cascione M, Gigli G, Cortese B. Substrate stiffness effect on molecular crosstalk of epithelial-mesenchymal transition mediators of human glioblastoma cells. Front Oncol 2022; 12:983507. [PMID: 36091138 PMCID: PMC9454310 DOI: 10.3389/fonc.2022.983507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/04/2022] [Indexed: 11/13/2022] Open
Abstract
The complexity of the microenvironment effects on cell response, show accumulating evidence that glioblastoma (GBM) migration and invasiveness are influenced by the mechanical rigidity of their surroundings. The epithelial–mesenchymal transition (EMT) is a well-recognized driving force of the invasive behavior of cancer. However, the primary mechanisms of EMT initiation and progression remain unclear. We have previously showed that certain substrate stiffness can selectively stimulate human GBM U251-MG and GL15 glioblastoma cell lines motility. The present study unifies several known EMT mediators to uncover the reason of the regulation and response to these stiffnesses. Our results revealed that changing the rigidity of the mechanical environment tuned the response of both cell lines through change in morphological features, epithelial-mesenchymal markers (E-, N-Cadherin), EGFR and ROS expressions in an interrelated manner. Specifically, a stiffer microenvironment induced a mesenchymal cell shape, a more fragmented morphology, higher intracellular cytosolic ROS expression and lower mitochondrial ROS. Finally, we observed that cells more motile showed a more depolarized mitochondrial membrane potential. Unravelling the process that regulates GBM cells’ infiltrative behavior could provide new opportunities for identification of new targets and less invasive approaches for treatment.
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Affiliation(s)
| | - Ilaria Elena Palamà
- National Research Council-Nanotechnology Institute (CNR Nanotec), Lecce, Italy
| | - Stefania D’Amone
- National Research Council-Nanotechnology Institute (CNR Nanotec), Lecce, Italy
| | - Clotilde Lauro
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy
| | - Maria Rosito
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy
- Center for Life Nanoscience, Italian Institute of Technology (IIT), Rome, Italy
| | - Maddalena Grieco
- National Research Council-Nanotechnology Institute (CNR Nanotec), Lecce, Italy
| | - Patrizia Ratano
- National Research Council-Nanotechnology Institute (CNR Nanotec), Rome, Italy
| | - Federica Cordella
- Center for Life Nanoscience, Italian Institute of Technology (IIT), Rome, Italy
| | - Caterina Sanchini
- Center for Life Nanoscience, Italian Institute of Technology (IIT), Rome, Italy
| | - Silvia Di Angelantonio
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy
- Center for Life Nanoscience, Italian Institute of Technology (IIT), Rome, Italy
| | - Davide Ragozzino
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy
| | | | - Giuseppe Gigli
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy
- Department of Mathematics and Physics “Ennio De Giorgi” University of Salento, Lecce, Italy
| | - Barbara Cortese
- National Research Council-Nanotechnology Institute (CNR Nanotec), Rome, Italy
- *Correspondence: Barbara Cortese,
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14
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Das R, Das S, Chakrabarti S, Chakrabarti O. CMT2A-linked mitochondrial hyperfusion-driving mutant MFN2 perturbs ER-mitochondrial associations and Ca 2+ homeostasis. Biol Cell 2022; 114:309-319. [PMID: 35924634 DOI: 10.1111/boc.202100098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 06/15/2022] [Accepted: 06/17/2022] [Indexed: 11/27/2022]
Abstract
Mitofusin2 (MFN2), an important molecular player that regulates mitochondrial fusion, also helps maintain the inter-organellar contact sites, referred as mitochondria associated membranes (MAMs) that exist between the ER and mitochondria. Here we show that a mutant of MFN2, R364W-MFN2, linked with the Charcot Marie Tooth disease, promotes mitochondrial hyperfusion, alters ER mitochondrial associations at the MAM junctions and perturbs inter-organellar calcium homeostasis. Such hyperfused mitochondria are also predisposed towards stress and undergo rapid fission upon induction of mild stress. Thus, here we report that presence of the R364W-MFN2 mutation makes cells susceptible towards stress, thus negatively affecting cellular health. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Rajdeep Das
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India.,Homi Bhabha, National Institute
| | - Subhrangshu Das
- Structural Biology and Bioinformatics Division, CSIR Indian Institute of Chemical Biology, CN 6, Sector V, Salt Lake, Kolkata, 700091, India.,Academy of Scientific and Innovative Research (AcSIR), Gaziabad, India
| | - Saikat Chakrabarti
- Structural Biology and Bioinformatics Division, CSIR Indian Institute of Chemical Biology, CN 6, Sector V, Salt Lake, Kolkata, 700091, India.,Academy of Scientific and Innovative Research (AcSIR), Gaziabad, India
| | - Oishee Chakrabarti
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India.,Homi Bhabha, National Institute
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15
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Tong Y, Zhang Z, Wang S. Role of Mitochondria in Retinal Pigment Epithelial Aging and Degeneration. FRONTIERS IN AGING 2022; 3:926627. [PMID: 35912040 PMCID: PMC9337215 DOI: 10.3389/fragi.2022.926627] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/21/2022] [Indexed: 12/17/2022]
Abstract
Retinal pigment epithelial (RPE) cells form a monolayer between the neuroretina and choroid. It has multiple important functions, including acting as outer blood-retina barrier, maintaining the function of neuroretina and photoreceptors, participating in the visual cycle and regulating retinal immune response. Due to high oxidative stress environment, RPE cells are vulnerable to dysfunction, cellular senescence, and cell death, which underlies RPE aging and age-related diseases, including age-related macular degeneration (AMD). Mitochondria are the powerhouse of cells and a major source of cellular reactive oxygen species (ROS) that contribute to mitochondrial DNA damage, cell death, senescence, and age-related diseases. Mitochondria also undergo dynamic changes including fission/fusion, biogenesis and mitophagy for quality control in response to stresses. The role of mitochondria, especially mitochondrial dynamics, in RPE aging and age-related diseases, is still unclear. In this review, we summarize the current understanding of mitochondrial function, biogenesis and especially dynamics such as morphological changes and mitophagy in RPE aging and age-related RPE diseases, as well as in the biological processes of RPE cellular senescence and cell death. We also discuss the current preclinical and clinical research efforts to prevent or treat RPE degeneration by restoring mitochondrial function and dynamics.
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Affiliation(s)
- Yao Tong
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
| | - Zunyi Zhang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
| | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
- Department of Ophthalmology, Tulane University, New Orleans, LA, United States
- Tulane Personalized Health Institute, Tulane University, New Orleans, LA, United States
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16
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Das R, Kamal IM, Das S, Chakrabarti S, Chakrabarti O. MITOL-mediated DRP1 ubiquitylation and degradation promotes mitochondrial hyperfusion in CMT2A-linked MFN2 mutant. J Cell Sci 2021; 135:273638. [PMID: 34870686 DOI: 10.1242/jcs.257808] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 11/29/2021] [Indexed: 11/20/2022] Open
Abstract
Mutations in Mitofusin2 (MFN2), associated with the pathology of the debilitating neuropathy, Charcot-Marie-Tooth type 2A (CMT2A) are known to alter mitochondrial morphology. One such abundant MFN2 mutant, R364W results in the generation of elongated, interconnected mitochondria. However, the mechanism leading to this mitochondrial aberration remains poorly understood. Here we show that mitochondrial hyperfusion in the presence of R364W-MFN2 is due to increased degradation of DRP1. The Ubiquitin E3 ligase MITOL is known to ubiquitylate both MFN2 and DRP1. Interaction with and its subsequent ubiquitylation by MITOL is stronger in presence of WT-MFN2 than R364W-MFN2. This differential interaction of MITOL with MFN2 in the presence of R364W-MFN2 renders the ligase more available for DRP1 ubiquitylation. Multimonoubiquitylation and proteasomal degradation of DRP1 in R364W-MFN2 cells in the presence of MITOL eventually leads to mitochondrial hyperfusion. Here we provide a mechanistic insight into mitochondrial hyperfusion, while also reporting that MFN2 can indirectly modulate DRP1 - an effect not shown before.
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Affiliation(s)
- Rajdeep Das
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata - 700064, India.,Homi Bhabha National Institute, India
| | - Izaz Monir Kamal
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, CN 6, Sector V, Salt Lake, Kolkata - 700091, India.,Academy of Scientific and Innovative Research (AcSIR), Gaziabad, India
| | - Subhrangshu Das
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, CN 6, Sector V, Salt Lake, Kolkata - 700091, India
| | - Saikat Chakrabarti
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, CN 6, Sector V, Salt Lake, Kolkata - 700091, India.,Academy of Scientific and Innovative Research (AcSIR), Gaziabad, India
| | - Oishee Chakrabarti
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata - 700064, India.,Homi Bhabha National Institute, India
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17
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Spurlock B, Parker D, Basu MK, Hjelmeland A, GC S, Liu S, Siegal GP, Gunter A, Moran A, Mitra K. Fine-tuned repression of Drp1-driven mitochondrial fission primes a 'stem/progenitor-like state' to support neoplastic transformation. eLife 2021; 10:e68394. [PMID: 34545812 PMCID: PMC8497058 DOI: 10.7554/elife.68394] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 09/08/2021] [Indexed: 12/13/2022] Open
Abstract
Gene knockout of the master regulator of mitochondrial fission, Drp1, prevents neoplastic transformation. Also, mitochondrial fission and its opposing process of mitochondrial fusion are emerging as crucial regulators of stemness. Intriguingly, stem/progenitor cells maintaining repressed mitochondrial fission are primed for self-renewal and proliferation. Using our newly derived carcinogen transformed human cell model, we demonstrate that fine-tuned Drp1 repression primes a slow cycling 'stem/progenitor-like state', which is characterized by small networks of fused mitochondria and a gene-expression profile with elevated functional stem/progenitor markers (Krt15, Sox2 etc) and their regulators (Cyclin E). Fine tuning Drp1 protein by reducing its activating phosphorylation sustains the neoplastic stem/progenitor cell markers. Whereas, fine-tuned reduction of Drp1 protein maintains the characteristic mitochondrial shape and gene-expression of the primed 'stem/progenitor-like state' to accelerate neoplastic transformation, and more complete reduction of Drp1 protein prevents it. Therefore, our data highlights a 'goldilocks' level of Drp1 repression supporting stem/progenitor state dependent neoplastic transformation.
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Affiliation(s)
- Brian Spurlock
- Department of Genetics, University of Alabama at BirminghamBirminghamUnited States
| | - Danitra Parker
- Department of Genetics, University of Alabama at BirminghamBirminghamUnited States
| | - Malay Kumar Basu
- Departments of Pathology, University of Alabama at BirminghamBirminghamUnited States
| | - Anita Hjelmeland
- Department of Cell Development and Integrative Biology, University of Alabama at BirminghamBirminghamUnited States
| | - Sajina GC
- Department of Cell Development and Integrative Biology, University of Alabama at BirminghamBirminghamUnited States
| | - Shanrun Liu
- Department of Genetics, University of Alabama at BirminghamBirminghamUnited States
| | - Gene P Siegal
- Departments of Pathology, Surgery, Genetics and Cell and Developmental Biology, University of Alabama at BirminghamBirminghamUnited States
| | - Alan Gunter
- Department of Genetics, University of Alabama at BirminghamBirminghamUnited States
| | - Aida Moran
- Department of Genetics, University of Alabama at BirminghamBirminghamUnited States
| | - Kasturi Mitra
- Department of Genetics, University of Alabama at BirminghamBirminghamUnited States
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18
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Toxoplasma gondii association with host mitochondria requires key mitochondrial protein import machinery. Proc Natl Acad Sci U S A 2021; 118:2013336118. [PMID: 33723040 PMCID: PMC7999873 DOI: 10.1073/pnas.2013336118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Host mitochondrial association (HMA) is a well-known phenomenon during Toxoplasma gondii infection of the host cell. The T. gondii locus mitochondrial association factor 1 (MAF1) is required for HMA and MAF1 encodes distinct paralogs of secreted dense granule effector proteins, some of which mediate the HMA phenotype (MAF1b paralogs drive HMA; MAF1a paralogs do not). To identify host proteins required for MAF1b-mediated HMA, we performed unbiased, label-free quantitative proteomics on host cells infected with type II parasites expressing MAF1b, MAF1a, and an HMA-incompetent MAF1b mutant. Across these samples, we identified ∼1,360 MAF1-interacting proteins, but only 13 that were significantly and uniquely enriched in MAF1b pull-downs. The gene products include multiple mitochondria-associated proteins, including those that traffic to the mitochondrial outer membrane. Based on follow-up endoribonuclease-prepared short interfering RNA (esiRNA) experiments targeting these candidate MAF1b-targeted host factors, we determined that the mitochondrial receptor protein TOM70 and mitochondria-specific chaperone HSPA9 were essential mediators of HMA. Additionally, the enrichment of TOM70 at the parasitophorous vacuole membrane interface suggests parasite-driven sequestration of TOM70 by the parasite. These results show that the interface between the T. gondii vacuole and the host mitochondria is characterized by interactions between a single parasite effector and multiple target host proteins, some of which are critical for the HMA phenotype itself. The elucidation of the functional members of this complex will permit us to explain the link between HMA and changes in the biology of the host cell.
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19
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Chu Y, Park J, Kim E, Lee S. Fluorescent Materials for Monitoring Mitochondrial Biology. MATERIALS (BASEL, SWITZERLAND) 2021; 14:4180. [PMID: 34361379 PMCID: PMC8347261 DOI: 10.3390/ma14154180] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 01/10/2023]
Abstract
Mitochondria play important roles in diverse cellular processes such as energy production, cellular metabolism, and apoptosis to promote cell death. To investigate mitochondria-associated biological processes such as structure, dynamics, morphological change, metabolism, and mitophagy, there exists a continuous demand for visualizing and monitoring techniques elucidating mitochondrial biology and disease-relevancy. Due to the advantages of high sensitivity and practicality, fluorescence phenomena have been most widely used as scientific techniques for the visualization of biological phenomena and systems. In this review, we briefly overview the different types of fluorescent materials such as chemical probes, peptide- or protein-based probes, and nanomaterials for monitoring mitochondrial biology.
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Affiliation(s)
- Yeonjeong Chu
- Creative Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; (Y.C.); (J.P.)
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Jisoo Park
- Creative Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; (Y.C.); (J.P.)
| | - Eunha Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Sanghee Lee
- Creative Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; (Y.C.); (J.P.)
- Department of HY-KIST Bio-Convergence, Hanyang University, Seoul 02792, Korea
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20
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Drabik K, Piecyk K, Wolny A, Szulc-Dąbrowska L, Dębska-Vielhaber G, Vielhaber S, Duszyński J, Malińska D, Szczepanowska J. Adaptation of mitochondrial network dynamics and velocity of mitochondrial movement to chronic stress present in fibroblasts derived from patients with sporadic form of Alzheimer's disease. FASEB J 2021; 35:e21586. [PMID: 33960016 DOI: 10.1096/fj.202001978rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 03/11/2021] [Accepted: 03/25/2021] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Only 10% of all cases are familial form, the remaining 90% are sporadic form with unknown genetic background. The etiology of sporadic AD is still not fully understood. Pathogenesis and pathobiology of this disease are limited due to the limited number of experimental models. We used primary culture of fibroblasts derived from patients diagnosed with sporadic form of AD for investigation of dynamic properties of mitochondria, including fission-fusion process and localization of mitochondria within the cell. We observed differences in mitochondrial network organization with decreased mitochondrial transport velocity, and a drop in the frequency of fusion-fission events. These studies show how mitochondrial dynamics adapt to the conditions of long-term mitochondrial stress that prevails in cells of sporadic form of AD.
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Affiliation(s)
| | - Karolina Piecyk
- Nencki Institute of Experimental Biology, Warsaw, Poland.,Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Artur Wolny
- Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Lidia Szulc-Dąbrowska
- Institute of Veterinary Medicine, Department of Preclinical Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | | | - Stefan Vielhaber
- Department of Neurology, Otto-von-Guericke University of Magdeburg, Magdeburg, Germany
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21
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Cretin E, Lopes P, Vimont E, Tatsuta T, Langer T, Gazi A, Sachse M, Yu‐Wai‐Man P, Reynier P, Wai T. High-throughput screening identifies suppressors of mitochondrial fragmentation in OPA1 fibroblasts. EMBO Mol Med 2021; 13:e13579. [PMID: 34014035 PMCID: PMC8185549 DOI: 10.15252/emmm.202013579] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 12/22/2022] Open
Abstract
Mutations in OPA1 cause autosomal dominant optic atrophy (DOA) as well as DOA+, a phenotype characterized by more severe neurological deficits. OPA1 deficiency causes mitochondrial fragmentation and also disrupts cristae, respiration, mitochondrial DNA (mtDNA) maintenance, and cell viability. It has not yet been established whether phenotypic severity can be modulated by genetic modifiers of OPA1. We screened the entire known mitochondrial proteome (1,531 genes) to identify genes that control mitochondrial morphology using a first-in-kind imaging pipeline. We identified 145 known and novel candidate genes whose depletion promoted elongation or fragmentation of the mitochondrial network in control fibroblasts and 91 in DOA+ patient fibroblasts that prevented mitochondrial fragmentation, including phosphatidyl glycerophosphate synthase (PGS1). PGS1 depletion reduces CL content in mitochondria and rebalances mitochondrial dynamics in OPA1-deficient fibroblasts by inhibiting mitochondrial fission, which improves defective respiration, but does not rescue mtDNA depletion, cristae dysmorphology, or apoptotic sensitivity. Our data reveal that the multifaceted roles of OPA1 in mitochondria can be functionally uncoupled by modulating mitochondrial lipid metabolism, providing novel insights into the cellular relevance of mitochondrial fragmentation.
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Affiliation(s)
- Emma Cretin
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
- Université de ParisParisFrance
| | - Priscilla Lopes
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
| | - Elodie Vimont
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
| | | | - Thomas Langer
- Max‐Planck‐Institute for Biology of AgeingCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Anastasia Gazi
- UTechS Ultrastructural Bio ImagingInstitut PasteurParisFrance
| | - Martin Sachse
- UTechS Ultrastructural Bio ImagingInstitut PasteurParisFrance
| | - Patrick Yu‐Wai‐Man
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology UnitDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Cambridge Eye UnitAddenbrooke's HospitalCambridge University HospitalsCambridgeUK
- Moorfields Eye HospitalLondonUK
- UCL Institute of OphthalmologyUniversity College LondonLondonUK
| | - Pascal Reynier
- Laboratoire de Biochimie et biologie moléculaireCentre Hospitalier UniversitaireAngersFrance
- Unité Mixte de Recherche MITOVASCCNRS 6015INSERM U1083Université d'AngersAngersFrance
| | - Timothy Wai
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
- Université de ParisParisFrance
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22
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Tabernilla A, dos Santos Rodrigues B, Pieters A, Caufriez A, Leroy K, Van Campenhout R, Cooreman A, Gomes AR, Arnesdotter E, Gijbels E, Vinken M. In Vitro Liver Toxicity Testing of Chemicals: A Pragmatic Approach. Int J Mol Sci 2021; 22:5038. [PMID: 34068678 PMCID: PMC8126138 DOI: 10.3390/ijms22095038] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 02/07/2023] Open
Abstract
The liver is among the most frequently targeted organs by noxious chemicals of diverse nature. Liver toxicity testing using laboratory animals not only raises serious ethical questions, but is also rather poorly predictive of human safety towards chemicals. Increasing attention is, therefore, being paid to the development of non-animal and human-based testing schemes, which rely to a great extent on in vitro methodology. The present paper proposes a rationalized tiered in vitro testing strategy to detect liver toxicity triggered by chemicals, in which the first tier is focused on assessing general cytotoxicity, while the second tier is aimed at identifying liver-specific toxicity as such. A state-of-the-art overview is provided of the most commonly used in vitro assays that can be used in both tiers. Advantages and disadvantages of each assay as well as overall practical considerations are discussed.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Mathieu Vinken
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.T.); (B.d.S.R.); (A.P.); (A.C.); (K.L.); (R.V.C.); (A.C.); (A.R.G.); (E.A.); (E.G.)
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23
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Peruzzotti-Jametti L, Bernstock JD, Willis CM, Manferrari G, Rogall R, Fernandez-Vizarra E, Williamson JC, Braga A, van den Bosch A, Leonardi T, Krzak G, Kittel Á, Benincá C, Vicario N, Tan S, Bastos C, Bicci I, Iraci N, Smith JA, Peacock B, Muller KH, Lehner PJ, Buzas EI, Faria N, Zeviani M, Frezza C, Brisson A, Matheson NJ, Viscomi C, Pluchino S. Neural stem cells traffic functional mitochondria via extracellular vesicles. PLoS Biol 2021; 19:e3001166. [PMID: 33826607 PMCID: PMC8055036 DOI: 10.1371/journal.pbio.3001166] [Citation(s) in RCA: 115] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/19/2021] [Accepted: 03/02/2021] [Indexed: 12/20/2022] Open
Abstract
Neural stem cell (NSC) transplantation induces recovery in animal models of central nervous system (CNS) diseases. Although the replacement of lost endogenous cells was originally proposed as the primary healing mechanism of NSC grafts, it is now clear that transplanted NSCs operate via multiple mechanisms, including the horizontal exchange of therapeutic cargoes to host cells via extracellular vesicles (EVs). EVs are membrane particles trafficking nucleic acids, proteins, metabolites and metabolic enzymes, lipids, and entire organelles. However, the function and the contribution of these cargoes to the broad therapeutic effects of NSCs are yet to be fully understood. Mitochondrial dysfunction is an established feature of several inflammatory and degenerative CNS disorders, most of which are potentially treatable with exogenous stem cell therapeutics. Herein, we investigated the hypothesis that NSCs release and traffic functional mitochondria via EVs to restore mitochondrial function in target cells. Untargeted proteomics revealed a significant enrichment of mitochondrial proteins spontaneously released by NSCs in EVs. Morphological and functional analyses confirmed the presence of ultrastructurally intact mitochondria within EVs with conserved membrane potential and respiration. We found that the transfer of these mitochondria from EVs to mtDNA-deficient L929 Rho0 cells rescued mitochondrial function and increased Rho0 cell survival. Furthermore, the incorporation of mitochondria from EVs into inflammatory mononuclear phagocytes restored normal mitochondrial dynamics and cellular metabolism and reduced the expression of pro-inflammatory markers in target cells. When transplanted in an animal model of multiple sclerosis, exogenous NSCs actively transferred mitochondria to mononuclear phagocytes and induced a significant amelioration of clinical deficits. Our data provide the first evidence that NSCs deliver functional mitochondria to target cells via EVs, paving the way for the development of novel (a)cellular approaches aimed at restoring mitochondrial dysfunction not only in multiple sclerosis, but also in degenerative neurological diseases.
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Affiliation(s)
- Luca Peruzzotti-Jametti
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | - Joshua D. Bernstock
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
- National Institutes of Health (NINDS/NIH), Bethesda, Maryland, United States of America
| | - Cory M. Willis
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | - Giulia Manferrari
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | - Rebecca Rogall
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | | | - James C. Williamson
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of Cambridge, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge, United Kingdom
| | - Alice Braga
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | - Aletta van den Bosch
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | - Tommaso Leonardi
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
- Center for Genomic Science of IIT@SEMM, Istituto Italiano di Tecnologia (IIT), Milan, Italy
| | - Grzegorz Krzak
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | - Ágnes Kittel
- Institute of Experimental Medicine, Eötvös Lorand Research Network, Budapest, Hungary
| | - Cristiane Benincá
- MRC Mitochondrial Biology Unit, University of Cambridge, United Kingdom
| | - Nunzio Vicario
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
- Department of Biomedical and Biotechnological Sciences (BIOMETEC), University of Catania, Italy
| | | | - Carlos Bastos
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Iacopo Bicci
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
| | - Nunzio Iraci
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
- Department of Biomedical and Biotechnological Sciences (BIOMETEC), University of Catania, Italy
| | - Jayden A. Smith
- Cambridge Innovation Technologies Consulting (CITC) Limited, United Kingdom
| | - Ben Peacock
- NanoFCM Co., Ltd, Nottingham, United Kingdom
| | | | - Paul J. Lehner
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of Cambridge, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge, United Kingdom
| | - Edit Iren Buzas
- Semmelweis University, Budapest, Hungary
- HCEMM Kft HU, Budapest, Hungary
- ELKH-SE, Budapest, Hungary
| | - Nuno Faria
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, United Kingdom
| | - Christian Frezza
- MRC Cancer Unit, Hutchison/MRC Research Centre, University of Cambridge, Cambridge United Kingdom
| | | | - Nicholas J. Matheson
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of Cambridge, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge, United Kingdom
| | - Carlo Viscomi
- MRC Mitochondrial Biology Unit, University of Cambridge, United Kingdom
| | - Stefano Pluchino
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, United Kingdom
- Cambridge Innovation Technologies Consulting (CITC) Limited, United Kingdom
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24
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Spurlock B, Hanumanthu VS, Mitra K. Strategy of Isolating 'Primed' Tumor Initiating Cells Based on Mitochondrial Transmembrane Potential. Bio Protoc 2021; 11:e3945. [PMID: 33796619 PMCID: PMC8005873 DOI: 10.21769/bioprotoc.3945] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 12/13/2020] [Accepted: 01/19/2021] [Indexed: 12/13/2022] Open
Abstract
Various stem cells have been found to be dependent on mitochondrial energetics. The role of mitochondria in regulating the self-renewal of normal stem cells and stem-like tumor initiating cells (TICs) is increasingly being appreciated. We proposed that TIC populations have a sub population of cells that are "primed" by mitochondria for self-renewal. Using ovarian cancer model, we have developed a protocol to identify and isolate these "primed" cells using Fluorescence-Assisted Cell Sorting (FACS). We combined live cell stains for a functional marker of TICs and for mitochondrial transmembrane potential to enrich TICs with higher mitochondrial potential that form in vitro spheroids 10-fold more than the other TICs with lower mitochondrial potential. This protocol can be directly used or modified to be used in various cell types. Thus, this protocol is anticipated to be invaluable for the basic understanding of mitochondrial and energetic heterogeneity within stem cell population, and may also prove valuable in translational studies in regenerative medicine and cancer biology.
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Affiliation(s)
- Brian Spurlock
- Department of Genetics, University of Alabama at Birmingham, AL 35294, USA
,
*For correspondence: ;
| | - Vidya Sagar Hanumanthu
- Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, AL 35294, USA
| | - Kasturi Mitra
- Department of Genetics, University of Alabama at Birmingham, AL 35294, USA
,
*For correspondence: ;
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25
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Thorne LS, Rochford G, Williams TD, Southam AD, Rodriguez-Blanco G, Dunn WB, Hodges NJ. Cytoglobin protects cancer cells from apoptosis by regulation of mitochondrial cardiolipin. Sci Rep 2021; 11:985. [PMID: 33441751 PMCID: PMC7806642 DOI: 10.1038/s41598-020-79830-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022] Open
Abstract
Cytoglobin is important in the progression of oral squamous cell carcinoma but the molecular and cellular basis remain to be elucidated. In the current study, we develop a new cell model to study the function of cytoglobin in oral squamous carcinoma and response to cisplatin. Transcriptomic profiling showed cytoglobin mediated changes in expression of genes related to stress response, redox metabolism, mitochondrial function, cell adhesion, and fatty acid metabolism. Cellular and biochemical studies show that cytoglobin expression results in changes to phenotype associated with cancer progression including: increased cellular proliferation, motility and cell cycle progression. Cytoglobin also protects cells from cisplatin-induced apoptosis and oxidative stress with levels of the antioxidant glutathione increased and total and mitochondrial reactive oxygen species levels reduced. The mechanism of cisplatin resistance involved inhibition of caspase 9 activation and cytoglobin protected mitochondria from oxidative stress-induced fission. To understand the mechanism behind these phenotypic changes we employed lipidomic analysis and demonstrate that levels of the redox sensitive and apoptosis regulating cardiolipin are significantly up-regulated in cells expressing cytoglobin. In conclusion, our data shows that cytoglobin expression results in important phenotypic changes that could be exploited by cancer cells in vivo to facilitate disease progression.
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Affiliation(s)
- Lorna S Thorne
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Garret Rochford
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Timothy D Williams
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Andrew D Southam
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Phenome Centre Birmingham, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Giovanny Rodriguez-Blanco
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Phenome Centre Birmingham, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Warwick B Dunn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Phenome Centre Birmingham, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Nikolas J Hodges
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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26
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Zorkau M, Proctor-Kent Y, Berlinguer-Palmini R, Hamilton A, Chrzanowska-Lightowlers ZM, Lightowlers RN. Visualizing Mitochondrial Ribosomal RNA and Mitochondrial Protein Synthesis in Human Cell Lines. Methods Mol Biol 2021; 2192:159-181. [PMID: 33230773 DOI: 10.1007/978-1-0716-0834-0_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Human mitochondria contain their own DNA (mtDNA) that encodes 13 proteins all of which are core subunits of oxidative phosphorylation (OXPHOS) complexes. To form functional complexes, these 13 components need to be correctly assembled with approximately 70 nuclear-encoded subunits that are imported following synthesis in the cytosol. How this complicated coordinated translation and assembly is choreographed is still not clear. Methods are being developed to determine whether all members of a particular complex are translated in close proximity, whether protein synthesis is clustered in submitochondrial factories, whether these align with incoming polypeptides, and if there is evidence for co-translational translation that is regulated and limited by the interaction of the incoming proteins with synthesis of their mtDNA-encoded partners. Two methods are described in this chapter to visualize the distribution of mitochondrial ribosomal RNAs in conjunction with newly synthesized mitochondrial proteins. The first combines RNA Fluorescent In Situ Hybridization (FISH) and super-resolution immunocytochemistry to pinpoint mitochondrial ribosomal RNA. The second localizes nascent translation within the mitochondrial network through non-canonical amino acid labeling, click chemistry and fluorescent microscopy.
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Affiliation(s)
- Matthew Zorkau
- Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Newcastle University, Medical School, Newcastle Upon Tyne, UK
| | - Yasmin Proctor-Kent
- Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Newcastle University, Medical School, Newcastle Upon Tyne, UK
| | | | - Andrew Hamilton
- School of Medicine, Dentistry and Nursing, Glasgow University, Glasgow, UK
| | - Zofia M Chrzanowska-Lightowlers
- Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Newcastle University, Medical School, Newcastle Upon Tyne, UK.
| | - Robert N Lightowlers
- Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Newcastle University, Medical School, Newcastle Upon Tyne, UK.
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27
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Retrograde Mitochondrial Transport Is Essential for Organelle Distribution and Health in Zebrafish Neurons. J Neurosci 2020; 41:1371-1392. [PMID: 33376159 PMCID: PMC7896009 DOI: 10.1523/jneurosci.1316-20.2020] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 12/12/2022] Open
Abstract
In neurons, mitochondria are transported by molecular motors throughout the cell to form and maintain functional neural connections. These organelles have many critical functions in neurons and are of high interest as their dysfunction is associated with disease. While the mechanics and impact of anterograde mitochondrial movement toward axon terminals are beginning to be understood, the frequency and function of retrograde (cell body directed) mitochondrial transport in neurons are still largely unexplored. While existing evidence indicates that some mitochondria are retrogradely transported for degradation in the cell body, the precise impact of disrupting retrograde transport on the organelles and the axon was unknown. Using long-term, in vivo imaging, we examined mitochondrial motility in zebrafish sensory and motor axons. We show that retrograde transport of mitochondria from axon terminals allows replacement of the axon terminal population within a day. By tracking these organelles, we show that not all mitochondria that leave the axon terminal are degraded; rather, they persist over several days. Disrupting retrograde mitochondrial flux in neurons leads to accumulation of aged organelles in axon terminals and loss of cell body mitochondria. Assays of neural circuit activity demonstrated that disrupting mitochondrial transport and function has no effect on sensory axon terminal activity but does negatively impact motor neuron axons. Taken together, our work supports a previously unappreciated role for retrograde mitochondrial transport in the maintenance of a homeostatic distribution of mitochondria in neurons and illustrates the downstream effects of disrupting this process on sensory and motor circuits. SIGNIFICANCE STATEMENT Disrupted mitochondrial transport has been linked to neurodegenerative disease. Retrograde transport of this organelle has been implicated in turnover of aged organelles through lysosomal degradation in the cell body. Consistent with this, we provide evidence that retrograde mitochondrial transport is important for removing aged organelles from axons; however, we show that these organelles are not solely degraded, rather they persist in neurons for days. Disrupting retrograde mitochondrial transport impacts the homeostatic distribution of mitochondria throughout the neuron and the function of motor, but not sensory, axon synapses. Together, our work shows the conserved reliance on retrograde mitochondrial transport for maintaining a healthy mitochondrial pool in neurons and illustrates the disparate effects of disrupting this process on sensory versus motor circuits.
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28
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Pasquale V, Ducci G, Campioni G, Ventrici A, Assalini C, Busti S, Vanoni M, Vago R, Sacco E. Profiling and Targeting of Energy and Redox Metabolism in Grade 2 Bladder Cancer Cells with Different Invasiveness Properties. Cells 2020; 9:cells9122669. [PMID: 33322565 PMCID: PMC7764708 DOI: 10.3390/cells9122669] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022] Open
Abstract
Bladder cancer is one of the most prevalent deadly diseases worldwide. Grade 2 tumors represent a good window of therapeutic intervention, whose optimization requires high resolution biomarker identification. Here we characterize energy metabolism and cellular properties associated with spreading and tumor progression of RT112 and 5637, two Grade 2 cancer cell lines derived from human bladder, representative of luminal-like and basal-like tumors, respectively. The two cell lines have similar proliferation rates, but only 5637 cells show efficient lateral migration. In contrast, RT112 cells are more prone to form spheroids. RT112 cells produce more ATP by glycolysis and OXPHOS, present overall higher metabolic plasticity and are less sensitive than 5637 to nutritional perturbation of cell proliferation and migration induced by treatment with 2-deoxyglucose and metformin. On the contrary, spheroid formation is less sensitive to metabolic perturbations in 5637 than RT112 cells. The ability of metformin to reduce, although with different efficiency, cell proliferation, sphere formation and migration in both cell lines, suggests that OXPHOS targeting could be an effective strategy to reduce the invasiveness of Grade 2 bladder cancer cells.
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Affiliation(s)
- Valentina Pasquale
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy; (V.P.); (G.D.); (G.C.); (A.V.); (S.B.)
- SYSBIO-ISBE-IT-Candidate National Node of Italy for ISBE, Research Infrastructure for Systems Biology Europe, 20126 Milan, Italy
| | - Giacomo Ducci
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy; (V.P.); (G.D.); (G.C.); (A.V.); (S.B.)
- SYSBIO-ISBE-IT-Candidate National Node of Italy for ISBE, Research Infrastructure for Systems Biology Europe, 20126 Milan, Italy
| | - Gloria Campioni
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy; (V.P.); (G.D.); (G.C.); (A.V.); (S.B.)
- SYSBIO-ISBE-IT-Candidate National Node of Italy for ISBE, Research Infrastructure for Systems Biology Europe, 20126 Milan, Italy
| | - Adria Ventrici
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy; (V.P.); (G.D.); (G.C.); (A.V.); (S.B.)
| | - Chiara Assalini
- Urological Research Institute, Division of Experimental Oncology, IRCCS San Raffaele Hospital, 20132 Milan, Italy;
| | - Stefano Busti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy; (V.P.); (G.D.); (G.C.); (A.V.); (S.B.)
- SYSBIO-ISBE-IT-Candidate National Node of Italy for ISBE, Research Infrastructure for Systems Biology Europe, 20126 Milan, Italy
| | - Marco Vanoni
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy; (V.P.); (G.D.); (G.C.); (A.V.); (S.B.)
- SYSBIO-ISBE-IT-Candidate National Node of Italy for ISBE, Research Infrastructure for Systems Biology Europe, 20126 Milan, Italy
- Correspondence: (M.V.); (R.V.); (E.S.); Tel.: +39-02-6448-3525 (M.V.); +39-02-2643-5664 (R.V.); +39-02-6448-3379 (E.S.)
| | - Riccardo Vago
- Urological Research Institute, Division of Experimental Oncology, IRCCS San Raffaele Hospital, 20132 Milan, Italy;
- Università Vita-Salute San Raffaele, 20132 Milan, Italy
- Correspondence: (M.V.); (R.V.); (E.S.); Tel.: +39-02-6448-3525 (M.V.); +39-02-2643-5664 (R.V.); +39-02-6448-3379 (E.S.)
| | - Elena Sacco
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy; (V.P.); (G.D.); (G.C.); (A.V.); (S.B.)
- SYSBIO-ISBE-IT-Candidate National Node of Italy for ISBE, Research Infrastructure for Systems Biology Europe, 20126 Milan, Italy
- Correspondence: (M.V.); (R.V.); (E.S.); Tel.: +39-02-6448-3525 (M.V.); +39-02-2643-5664 (R.V.); +39-02-6448-3379 (E.S.)
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29
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Gambini E, Martinelli I, Stadiotti I, Vinci MC, Scopece A, Eramo L, Sommariva E, Resta J, Benaouadi S, Cogliati E, Paolin A, Parini A, Pompilio G, Savagner F. Differences in Mitochondrial Membrane Potential Identify Distinct Populations of Human Cardiac Mesenchymal Progenitor Cells. Int J Mol Sci 2020; 21:ijms21207467. [PMID: 33050449 PMCID: PMC7590175 DOI: 10.3390/ijms21207467] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 02/07/2023] Open
Abstract
Adult human cardiac mesenchymal progenitor cells (hCmPC) are multipotent resident populations involved in cardiac homeostasis and heart repair. Even if the mechanisms have not yet been fully elucidated, the stem cell differentiation is guided by the mitochondrial metabolism; however, mitochondrial approaches to identify hCmPC with enhanced stemness and/or differentiation capability for cellular therapy are not established. Here we demonstrated that hCmPCs sorted for low and high mitochondrial membrane potential (using a lipophilic cationic dye tetramethylrhodamine methyl ester, TMRM), presented differences in energy metabolism from preferential glycolysis to oxidative rates. TMRM-high cells are highly efficient in terms of oxygen consumption rate, basal and maximal respiration, and spare respiratory capacity compared to TMRM-low cells. TMRM-high cells showed characteristics of pre-committed cells and were associated with higher in vitro differentiation capacity through endothelial, cardiac-like, and, to a lesser extent, adipogenic and chondro/osteogenic cell lineage, when compared with TMRM-low cells. Conversely, TMRM-low showed higher self-renewal potential. To conclude, we identified two hCmPC populations with different metabolic profile, stemness maturity, and differentiation potential. Our findings suggest that metabolic sorting can isolate cells with higher regenerative capacity and/or long-term survival. This metabolism-based strategy to select cells may be broadly applicable to therapies.
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Affiliation(s)
- Elisa Gambini
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
- Correspondence:
| | - Ilenia Martinelli
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Toulouse, 31432 Toulouse, France; (I.M.); (S.B.); (A.P.); (F.S.)
| | - Ilaria Stadiotti
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
| | - Maria Cristina Vinci
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
| | - Alessandro Scopece
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
| | - Luana Eramo
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
| | - Elena Sommariva
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
| | - Jessica Resta
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Toulouse, 31432 Toulouse, France; (I.M.); (S.B.); (A.P.); (F.S.)
| | - Sabrina Benaouadi
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Toulouse, 31432 Toulouse, France; (I.M.); (S.B.); (A.P.); (F.S.)
| | - Elisa Cogliati
- Treviso Tissue Bank Foundation, Via Antonio Scarpa 9, 31100 Treviso, Italy; (E.C.); (A.P.)
| | - Adolfo Paolin
- Treviso Tissue Bank Foundation, Via Antonio Scarpa 9, 31100 Treviso, Italy; (E.C.); (A.P.)
| | - Angelo Parini
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Toulouse, 31432 Toulouse, France; (I.M.); (S.B.); (A.P.); (F.S.)
| | - Giulio Pompilio
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Carlo Parea 4, 20138 Milan, Italy; (I.S.); (M.C.V.); (A.S.); (L.E.); (E.S.); (J.R.); (G.P.)
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milan, Italy
| | - Frederique Savagner
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Toulouse, 31432 Toulouse, France; (I.M.); (S.B.); (A.P.); (F.S.)
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30
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Tumor Necrosis Factor-Like Weak Inducer of Apoptosis (TWEAK) Enhances Activation of STAT3/NLRC4 Inflammasome Signaling Axis through PKCδ in Astrocytes: Implications for Parkinson's Disease. Cells 2020; 9:cells9081831. [PMID: 32759670 PMCID: PMC7464730 DOI: 10.3390/cells9081831] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/26/2020] [Accepted: 07/31/2020] [Indexed: 12/15/2022] Open
Abstract
Astrocytic dysfunction has been implicated in Parkinson's disease (PD) pathogenesis. While the Tumor necrosis factor-like weak inducer of apoptosis (TWEAK)/Fn14 signaling axis is known to play a role in PD-like neuropathology, the molecular mechanisms that govern this process remain poorly understood. Herein, we show that TWEAK levels are elevated in PD serum compared to controls. Moreover, using both U373 human astrocyte cells and primary mouse astrocytes, we demonstrate that TWEAK induces mitochondrial oxidative stress as well as protein kinase C delta (PKCδ) and signal transducer and activator of transcription 3 (STAT3) activation, accompanied by NLRC4 inflammasome activation and upregulation and release of proinflammatory cytokines, including IL-1β, TNF-α, and IL-18. Mechanistically, TWEAK-induced PKCδ activation enhances the STAT3/NLRC4 signaling pathway and other proinflammatory mediators through a mitochondrial oxidative stress-dependent mechanism. We further show that PKCδ knockdown and mito-apocynin, a mitochondrial antioxidant, suppress TWEAK-induced proinflammatory NLRC4/STAT3 signaling and cellular oxidative stress response. Notably, we validated our in vitro findings in an MPTP mouse model of PD and in mice receiving intrastriatal administration of TWEAK. These results indicate that TWEAK is a key regulator of astroglial reactivity and illustrate a novel mechanism by which mitochondrial oxidative stress may influence dopaminergic neuronal survival in PD.
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31
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Quantitative Phosphoproteomics Reveals Cell Alignment and Mitochondrial Length Change under Cyclic Stretching in Lung Cells. Int J Mol Sci 2020; 21:ijms21114074. [PMID: 32517296 PMCID: PMC7312583 DOI: 10.3390/ijms21114074] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022] Open
Abstract
Lung cancer is a leading cause of death. Most previous studies have been based on traditional cell-culturing methods. However, lung cells are periodically subjected to mechanical forces during breathing. Understanding the mechanisms underlying the cyclic stretching induced in lung cells may be important for lung cancer therapy. Here, we applied cyclic stretching to stimulate the continual contraction that is present under physiological conditions in lung cells. We first uncovered the stretching-induced phosphoproteome in lung cancer cell line A549 and fibroblast cell line IMR-90. We identified 2048 and 2604 phosphosites corresponding to 837 and 1008 phosphoproteins in A549 and IMR-90, respectively. Furthermore, we combined our phosphoproteomics and public gene expression data to identify the biological functions in response to cyclic stretching. Interestingly, cytoskeletal and mitochondrial reorganization were enriched. We further used cell imaging analysis to validate the profiling results and found that this physical force changed cell alignment and mitochondrial length. This study not only reveals the molecular mechanism of cyclic stretching but also provides evidence that cell stretching causes cellular rearrangement and mitochondrial length change.
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32
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Rutkai I, Evans WR, Bess N, Salter-Cid T, Čikić S, Chandra PK, Katakam PVG, Mostany R, Busija DW. Chronic imaging of mitochondria in the murine cerebral vasculature using in vivo two-photon microscopy. Am J Physiol Heart Circ Physiol 2020; 318:H1379-H1386. [PMID: 32330090 DOI: 10.1152/ajpheart.00751.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mitochondria are important regulators of cerebral vascular function in health and disease, but progress in understanding their roles has been hindered by methodological limitations. We report the first in vivo imaging of mitochondria specific to the cerebral endothelium in real time in the same mouse for extended periods. Mice expressing Dendra2 fluorescent protein in mitochondria (mito-Dendra2) in the cerebral vascular endothelium were generated by breeding PhAM-floxed and Tie2-Cre mice. We used mito-Dendra2 expression, cranial window implantation, and two-photon microscopy to visualize mitochondria in the cerebral vascular endothelium of mice. Immunohistochemistry and mitochondrial staining were used to confirm the localization of the mitochondrial signal to endothelial cells and the specificity of mito-Dendra2 to mitochondria. Mito-Dendra2 and Rhodamine B-conjugated dextran allowed simultaneous determinations of mitochondrial density, vessel diameters, area, and mitochondria-to-vessel ratio in vivo, repeatedly, in the same mouse. Endothelial expression of mito-Dendra2 was confirmed in vitro on brain slices and aorta. In addition, we observed an overlapping mito-Dendra2 and Chromeo mitochondrial staining of cultured brain microvascular endothelial cells. Repeated imaging of the same location in the cerebral microcirculation in the same mouse demonstrated stability of mito-Dendra2. While the overall mitochondrial signal was stable over time, mitochondria within the same endothelial cell were mobile. In conclusion, our results indicate that the mito-Dendra2 signal and vascular parameters are suitable for real-time and longitudinal examination of mitochondria in vivo in the cerebral vasculature of mice.NEW & NOTEWORTHY We introduce an innovative in vivo approach to study mitochondria in the cerebral circulation in their physiological environment by demonstrating the feasibility of long-term imaging and three-dimensional reconstruction. We postulate that the appropriate combination of Cre/Lox system and two-photon microscopy will contribute to a better understanding of the role of mitochondria in not only endothelium but also the different cell types of the cerebral circulation.
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Affiliation(s)
- Ibolya Rutkai
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.,Tulane Brain Institute, Tulane University, New Orleans, Louisiana
| | - Wesley R Evans
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.,Tulane Brain Institute, Tulane University, New Orleans, Louisiana
| | - Nikita Bess
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Tomas Salter-Cid
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.,Tulane Brain Institute, Tulane University, New Orleans, Louisiana
| | - Siniša Čikić
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Partha K Chandra
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Prasad V G Katakam
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.,Tulane Brain Institute, Tulane University, New Orleans, Louisiana
| | - Ricardo Mostany
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.,Tulane Brain Institute, Tulane University, New Orleans, Louisiana
| | - David W Busija
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.,Tulane Brain Institute, Tulane University, New Orleans, Louisiana
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33
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Investigating Tunneling Nanotubes in Cancer Cells: Guidelines for Structural and Functional Studies through Cell Imaging. BIOMED RESEARCH INTERNATIONAL 2020; 2020:2701345. [PMID: 32351987 PMCID: PMC7174938 DOI: 10.1155/2020/2701345] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 03/23/2020] [Indexed: 12/24/2022]
Abstract
By allowing insured communication between cancer cells themselves and with the neighboring stromal cells, tunneling nanotubes (TNTs) are involved in the multistep process of cancer development from tumorigenesis to the treatment resistance. However, despite their critical role in the biology of cancer, the study of the TNTs has been announced challenging due to not only the absence of a specific biomarker but also the fragile and transitory nature of their structure and the fact that they are hovering freely above the substratum. Here, we proposed to review guidelines to follow for studying the structure and functionality of TNTs in tumoral neuroendocrine cells (PC12) and nontumorigenic human bronchial epithelial cells (HBEC-3, H28). In particular, we reported how crucial is it (i) to consider the culture conditions (culture surface, cell density), (ii) to visualize the formation of TNTs in living cells (mechanisms of formation, 3D representation), and (iii) to identify the cytoskeleton components and the associated elements (categories, origin, tip, and formation/transport) in the TNTs. We also focused on the input of high-resolution cell imaging approaches including Stimulated Emission Depletion (STED) nanoscopy, Transmitted and Scanning Electron Microscopies (TEM and SEM). In addition, we underlined the important role of the organelles in the mechanisms of TNT formation and transfer between the cancer cells. Finally, new biological models for the identification of the TNTs between cancer cells and stromal cells (liquid air interface, ex vivo, in vivo) and the clinical considerations will also be discussed.
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34
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Perry CJ, Warren EC, Damstra-Oddy JL, Storey C, Francione LM, Annesley SJ, Fisher PR, Müller-Taubenberger A, Williams RSB. A Dictyostelium discoideum mitochondrial fluorescent tagging vector that does not affect respiratory function. Biochem Biophys Rep 2020; 22:100751. [PMID: 32258439 PMCID: PMC7109396 DOI: 10.1016/j.bbrep.2020.100751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/05/2020] [Accepted: 03/10/2020] [Indexed: 02/01/2023] Open
Abstract
Visualizing mitochondria in living Dictyostelium discoideum cells using fluorescent dyes is often problematic due to variability in staining, metabolism of the dyes, and unknown potential effects of the dyes on mitochondrial function. We show that fluorescent labelling of mitochondria, using an N-terminal mitochondrial localization sequence derived from the D. discoideum protein GcvH1 (glycine cleavage system H1) attached to a red fluorescent protein enables clear mitochondrial imaging. We also show that this labelling has no effect upon mitochondria load or respiratory function.
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Affiliation(s)
- Christopher J Perry
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Eleanor C Warren
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Joseph L Damstra-Oddy
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Claire Storey
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Lisa M Francione
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Sarah J Annesley
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Paul R Fisher
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, 3086, Australia
| | | | - Robin S B Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
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35
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Single organelle analysis to characterize mitochondrial function and crosstalk during viral infection. Sci Rep 2019; 9:8492. [PMID: 31186476 PMCID: PMC6560178 DOI: 10.1038/s41598-019-44922-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 05/23/2019] [Indexed: 12/23/2022] Open
Abstract
Mitochondria are key for cellular metabolism and signalling processes during viral infection. We report a methodology to analyse mitochondrial properties at the single-organelle level during viral infection using a recombinant adenovirus coding for a mitochondrial tracer protein for tagging and detection by multispectral flow cytometry. Resolution at the level of tagged individual mitochondria revealed changes in mitochondrial size, membrane potential and displayed a fragile phenotype during viral infection of cells. Thus, single-organelle and multi-parameter resolution allows to explore altered energy metabolism and antiviral defence by tagged mitochondria selectively in virus-infected cells and will be instrumental to identify viral immune escape and to develop and monitor novel mitochondrial-targeted therapies.
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36
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Spurlock B, Gupta P, Basu MK, Mukherjee A, Hjelmeland AB, Darley-Usmar V, Parker D, Foxall ME, Mitra K. New quantitative approach reveals heterogeneity in mitochondrial structure-function relations in tumor-initiating cells. J Cell Sci 2019; 132:jcs.230755. [PMID: 30910831 DOI: 10.1242/jcs.230755] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/18/2019] [Indexed: 12/12/2022] Open
Abstract
Steady-state mitochondrial structure or morphology is primarily maintained by a balance of opposing fission and fusion events between individual mitochondria, which is collectively referred to as mitochondrial dynamics. The details of the bidirectional relationship between the status of mitochondrial dynamics (structure) and energetics (function) require methods to integrate these mitochondrial aspects. To study the quantitative relationship between the status of mitochondrial dynamics (fission, fusion, matrix continuity and diameter) and energetics (ATP and redox), we have developed an analytical approach called mito-SinCe2 After validating and providing proof of principle, we applied mito-SinCe2 on ovarian tumor-initiating cells (ovTICs). Mito-SinCe2 analyses led to the hypothesis that mitochondria-dependent ovTICs interconvert between three states, that have distinct relationships between mitochondrial energetics and dynamics. Interestingly, fusion and ATP increase linearly with each other only once a certain level of fusion is attained. Moreover, mitochondrial dynamics status changes linearly with ATP or with redox, but not simultaneously with both. Furthermore, mito-SinCe2 analyses can potentially predict new quantitative features of the opposing fission versus fusion relationship and classify cells into functional classes based on their mito-SinCe2 states.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Brian Spurlock
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Priyanka Gupta
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Malay Kumar Basu
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Avik Mukherjee
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Anita B Hjelmeland
- Department of Cell Development and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Victor Darley-Usmar
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Danitra Parker
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - McKenzie E Foxall
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Kasturi Mitra
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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37
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Alfaqaan S, Yoshida T, Imamura H, Tsukano C, Takemoto Y, Kakizuka A. PPARα-Mediated Positive-Feedback Loop Contributes to Cold Exposure Memory. Sci Rep 2019; 9:4538. [PMID: 30872768 PMCID: PMC6418111 DOI: 10.1038/s41598-019-40633-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/20/2019] [Indexed: 12/17/2022] Open
Abstract
Fluctuations in food availability and shifts in temperature are typical environmental changes experienced by animals. These environmental shifts sometimes portend more severe changes; e.g., chilly north winds precede the onset of winter. Such telltale signs may be indicators for animals to prepare for such a shift. Here we show that HEK293A cells, cultured under starvation conditions, can “memorize” a short exposure to cold temperature (15 °C), which was evidenced by their higher survival rate compared to cells continuously grown at 37 °C. We refer to this phenomenon as “cold adaptation”. The cold-exposed cells retained high ATP levels, and addition of etomoxir, a fatty acid oxidation inhibitor, abrogated the enhanced cell survival. In our standard protocol, cold adaptation required linoleic acid (LA) supplementation along with the activity of Δ-6-desaturase (D6D), a key enzyme in LA metabolism. Moreover, supplementation with the LA metabolite arachidonic acid (AA), which is a high-affinity agonist of peroxisome proliferator-activated receptor-alpha (PPARα), was able to underpin the cold adaptation, even in the presence of a D6D inhibitor. Cold exposure with added LA or AA prompted a surge in PPARα levels, followed by the induction of D6D expression; addition of a PPARα antagonist or a D6D inhibitor abrogated both their expression, and reduced cell survival to control levels. We also found that the brief cold exposure transiently prevents PPARα degradation by inhibiting the ubiquitin proteasome system, and starvation contributes to the enhancement of PPARα activity by inhibiting mTORC1. Our results reveal an innate adaptive positive-feedback mechanism with a PPARα-D6D-AA axis that is triggered by a brief cold exposure in cells. “Cold adaptation” could have evolved to increase strength and resilience against imminent extreme cold temperatures.
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Affiliation(s)
- Soaad Alfaqaan
- Laboratory of Functional Biology, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Tomoki Yoshida
- Laboratory of Functional Biology, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Hiromi Imamura
- Laboratory of Functional Biology, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Chihiro Tsukano
- Department of Organic Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Sakyo-ku, Kyoto, Japan
| | - Yoshiji Takemoto
- Department of Organic Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Sakyo-ku, Kyoto, Japan
| | - Akira Kakizuka
- Laboratory of Functional Biology, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan.
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38
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Kaushal JB, Popli P, Sankhwar P, Shukla V, Dwivedi A. Sonic hedgehog protects endometrial hyperplasial cells against oxidative stress via suppressing mitochondrial fission protein dynamin-like GTPase (Drp1). Free Radic Biol Med 2018; 129:582-599. [PMID: 30347228 DOI: 10.1016/j.freeradbiomed.2018.10.427] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/12/2018] [Accepted: 10/14/2018] [Indexed: 02/07/2023]
Abstract
Hh/Gli1 cascade as well as Gsk3β-Gli1 crosstalk play crucial role in estrogen-dependent progression of endometrial hyperplasia (EH). However, the underlying mechanisms involved in progression of disease still remain unclear. In the present study, we explored the role of Hh signaling in protection of endometrial hyperplasial cells against oxidative stress and the underlying mechanism involved therein. EH cells were found to be more resistant towards H2O2-induced oxidative stress (IC50: ~ 3×) as compared with normal endometrial cells. Estrogen (E2) pre-treatment followed by cytotoxic dose of H2O2, almost rescued the EH cells from apoptosis and caused the increased expression of downstream Shh signaling molecules i.e., Smo, Ptch and Gli1. Whereas pretreatment with cyclopamine was not able to curtail H2O2-induced effects indicating that estrogen protects these cells via activation of Shh pathway. Further, H2O2-induced ROS and lipid peroxidation alongwith decreased activities of antioxidant enzymes glutathione peroxidase and superoxide dismutase were found to be reversed in EH cells pre-exposed to E2 or rShh. The rShh suppressed H2O2-induced cell death and caused attenuation of mitochondrial apoptotic mediators and prevented disruption in mitochondrial morphology and mitochondrial membrane potential in EH cells. The functional blockage of signaling by Shh siRNA or Gli1siRNA led to significantly increased expression of mitochondrial fission protein dynamin-like GTPase (Drp1). The H2O2-treated EH cells showed diminished Gli1 and increased Drp1 expression, concurrent with reduced p-Drp1-(serine637). Whereas rShh pre-treated EH cells presented normal mitochondrial dynamics with dense, long networks of mitochondria alongwith nuclear accumulation of Gli1 and the decreased expression of Drp1. Overall, our results implicated that Shh signaling modulates antioxidant defense system and stabilizes mitochondrial dynamics by suppressing Drp1 protein which maintains survival of EH cells against oxidative stress.
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Affiliation(s)
- Jyoti B Kaushal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, U.P., India; Academy of Scientific and Innovative Research (AcSIR), CSIR-CDRI Campus, Lucknow 226031, U.P., India
| | - Pooja Popli
- Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, U.P., India
| | - Pushplata Sankhwar
- Department of Obstetrics & Gynaecology, King George's Medical University, Lucknow 226003, U.P., India
| | - Vinay Shukla
- Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, U.P., India; Academy of Scientific and Innovative Research (AcSIR), CSIR-CDRI Campus, Lucknow 226031, U.P., India
| | - Anila Dwivedi
- Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, U.P., India; Academy of Scientific and Innovative Research (AcSIR), CSIR-CDRI Campus, Lucknow 226031, U.P., India.
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39
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Tobias IC, Khazaee R, Betts DH. Analysis of Mitochondrial Dimensions and Cristae Structure in Pluripotent Stem Cells Using Transmission Electron Microscopy. ACTA ACUST UNITED AC 2018; 47:e67. [PMID: 30303625 DOI: 10.1002/cpsc.67] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dynamic alterations to mitochondrial structure and function regulate cell fate decisions and underlie multiple age-related and genetic diseases that are modeled using embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Transmission electron microscopy (TEM) can be used to obtain high-resolution micrographs of mitochondria, but mitochondrial ultrastructure is easily distorted during specimen processing. This unit describes a method that preserves mitochondrial membrane structure from adherent ESC cultures for TEM sample preparation. This procedure is useful for assessing ultrastructural changes to mitochondria during differentiation, reprogramming, or experimental manipulation of ESC metabolism. We provide comprehensive protocols for: (1) preparation of ESC cultures for TEM; (2) retrieval of thin sections from individual ESCs; and (3) contrast staining and morphometric analysis of mitochondria and cristae. This unit also describes an alternative procedure for samples with low cell numbers and a supporting protocol for morphometric image analysis. Collectively, these protocols allow for the observation and quantitative analysis of mitochondria in ESCs. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- I C Tobias
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - R Khazaee
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,Lawson Health Research Institute, Western University, London, Ontario, Canada.,Biotron Integrated Microscopy Facility, Biotron Research Centre, Western University, London, Ontario, Canada
| | - D H Betts
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,Children's Health Research Institute, Western University, London, Ontario, Canada
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40
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Roobala C, Ilanila IP, Basu JK. Applications of STED fluorescence nanoscopy in unravelling nanoscale structure and dynamics of biological systems. J Biosci 2018; 43:471-484. [PMID: 30002267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fluorescence microscopy, especially confocal microscopy, has revolutionized the field of biological imaging. Breaking the optical diffraction barrier of conventional light microscopy, through the advent of super-resolution microscopy, has ushered in the potential for a second revolution through unprecedented insight into nanoscale structure and dynamics in biological systems. Stimulated emission depletion (STED) microscopy is one such super-resolution microscopy technique which provides real-time enhanced-resolution imaging capabilities. In addition, it can be easily integrated with well-established fluorescence-based techniques such as fluorescence correlation spectroscopy (FCS) in order to capture the structure of cellular membranes at the nanoscale with high temporal resolution. In this review, we discuss the theory of STED and different modalities of operation in order to achieve the best resolution. Various applications of this technique in cell imaging, especially that of neuronal cell imaging, are discussed as well as examples of application of STED imaging in unravelling structure formation on biological membranes. Finally, we have discussed examples from some of our recent studies on nanoscale structure and dynamics of lipids in model membranes, due to interaction with proteins, as revealed by combination of STED and FCS techniques.
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Affiliation(s)
- C Roobala
- Department of Physics, Indian Institute of Science, Bengaluru 560 012, India
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41
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Blank ML, Parker ML, Ramaswamy R, Powell CJ, English ED, Adomako-Ankomah Y, Pernas LF, Workman SD, Boothroyd JC, Boulanger MJ, Boyle JP. A Toxoplasma gondii locus required for the direct manipulation of host mitochondria has maintained multiple ancestral functions. Mol Microbiol 2018; 108:519-535. [PMID: 29505111 PMCID: PMC6245547 DOI: 10.1111/mmi.13947] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2018] [Indexed: 01/16/2023]
Abstract
The Toxoplasma gondii locus mitochondrial association factor 1 (MAF1) encodes multiple paralogs, some of which mediate host mitochondrial association (HMA). Previous work showed that HMA was a trait that arose in T. gondii through neofunctionalization of an ancestral MAF1 ortholog. Structural analysis of HMA-competent and incompetent MAF1 paralogs (MAF1b and MAF1a, respectively) revealed that both paralogs harbor an ADP ribose binding macro-domain, with comparatively low (micromolar) affinity for ADP ribose. Replacing the 16 C-terminal residues of MAF1b with those of MAF1a abrogated HMA, and we also show that only three residues in the C-terminal helix are required for MAF1-mediated HMA. Importantly these same three residues are also required for the in vivo growth advantage conferred by MAF1b, providing a definitive link between in vivo proliferation and manipulation of host mitochondria. Co-immunoprecipitation assays reveal that the ability to interact with the mitochondrial MICOS complex is shared by HMA-competent and incompetent MAF1 paralogs and mutants. The weak ADPr coordination and ability to interact with the MICOS complex shared between divergent paralogs may represent modular ancestral functions for this tandemly expanded and diversified T. gondii locus.
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Affiliation(s)
- Matthew L. Blank
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michelle L. Parker
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Raghavendran Ramaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Cameron J. Powell
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Elizabeth D. English
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Yaw Adomako-Ankomah
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lena F. Pernas
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Sean D. Workman
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - John C. Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Martin J. Boulanger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Jon P. Boyle
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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42
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Fu D, Lippincott-Schwartz J. Monitoring the Effects of Pharmacological Reagents on Mitochondrial Morphology. ACTA ACUST UNITED AC 2018; 79:e45. [PMID: 29924486 DOI: 10.1002/cpcb.45] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This protocol describes how to apply appropriate pharmacological controls to induce mitochondrial fusion or fission in studies of mitochondria morphology for four different mammalian cell types, HepG2 human liver hepatocellular carcinoma cells, MCF7 human breast adenocarcinoma cells, HEK293 human embryonic kidney cells, and collagen sandwich culture of primary rat hepatocytes. The protocol provides methods of treating cells with these pharmacological controls, staining mitochondria with commercially available MitoTracker Green and TMRE dyes, and imaging the mitochondrial morphology in live cells using a confocal fluorescent microscope. It also describes the cell culture methods needed for this protocol. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Dong Fu
- UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, North Carolina.,Faculty of Pharmacy, The University of Sydney, Sydney, Australia
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43
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Lahuerta M, Aguado C, Sánchez-Martín P, Sanz P, Knecht E. Degradation of altered mitochondria by autophagy is impaired in Lafora disease. FEBS J 2018; 285:2071-2090. [PMID: 29645350 DOI: 10.1111/febs.14468] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 03/23/2018] [Accepted: 04/04/2018] [Indexed: 11/27/2022]
Abstract
Lafora disease (LD) is a fatal neurodegenerative disorder caused mostly by mutations in either of two genes encoding laforin and malin. LD is characterized by accumulation of a poorly branched form of glycogen in the cytoplasm of neurons and other cells. We previously reported dysfunctional mitochondria in different LD models. Now, using mitochondrial uncouplers and respiratory chain inhibitors, we have investigated with human fibroblasts a possible alteration in the selective degradation of damaged mitochondria (mitophagy) in LD. By flow cytometry of MitoTracker-labelled cells and measuring the levels of various mitochondrial proteins by western blot, we found in LD fibroblasts a partial impairment in the increased mitochondrial degradation produced by these treatments. In addition, colocalization of mitochondrial and lysosomal markers decreased in LD fibroblasts. All these results are consistent with a partial impairment in the induced autophagic degradation of dysfunctional mitochondria in LD fibroblasts. However, canonical recruitment of Parkin to mitochondria under these conditions remained unaffected in LD fibroblasts, and also in SH-SY5Y cells after malin and laforin overexpression. Neither mitochondrial localization nor protein levels of Bcl-2-like protein 13, another component of the mitophagic machinery that operates under these conditions, were affected in LD fibroblasts. In contrast, although these treatments raised autophagy in both control and LD fibroblasts, this enhanced autophagy was clearly lower in the latter cells. Therefore, the autophagic degradation of altered mitochondria is impaired in LD, which is due to a partial defect in the autophagic response and not in the canonical mitophagy signalling pathways.
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Affiliation(s)
| | - Carmen Aguado
- Centro de Investigación Príncipe Felipe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Pablo Sánchez-Martín
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.,Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Pascual Sanz
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.,Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Erwin Knecht
- Centro de Investigación Príncipe Felipe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
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44
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Harwig MC, Viana MP, Egner JM, Harwig JJ, Widlansky ME, Rafelski SM, Hill RB. Methods for imaging mammalian mitochondrial morphology: A prospective on MitoGraph. Anal Biochem 2018; 552:81-99. [PMID: 29505779 DOI: 10.1016/j.ab.2018.02.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/06/2018] [Accepted: 02/22/2018] [Indexed: 12/22/2022]
Abstract
Mitochondria are found in a variety of shapes, from small round punctate structures to a highly interconnected web. This morphological diversity is important for function, but complicates quantification. Consequently, early quantification efforts relied on various qualitative descriptors that understandably reduce the complexity of the network leading to challenges in consistency across the field. Recent application of state-of-the-art computational tools have resulted in more quantitative approaches. This prospective highlights the implementation of MitoGraph, an open-source image analysis platform for measuring mitochondrial morphology initially optimized for use with Saccharomyces cerevisiae. Here Mitograph was assessed on five different mammalian cells types, all of which were accurately segmented by MitoGraph analysis. MitoGraph also successfully differentiated between distinct mitochondrial morphologies that ranged from entirely fragmented to hyper-elongated. General recommendations are also provided for confocal imaging of labeled mitochondria (using mito-YFP, MitoTracker dyes and immunostaining parameters). Widespread adoption of MitoGraph will help achieve a long-sought goal of consistent and reproducible quantification of mitochondrial morphology.
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Affiliation(s)
- Megan C Harwig
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | - Matheus P Viana
- Visual Analytics and Comprehension Group, IBM Research, Brazil; Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California Irvine, Irvine, CA, 92697, United States
| | - John M Egner
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | | | - Michael E Widlansky
- Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | - Susanne M Rafelski
- Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California Irvine, Irvine, CA, 92697, United States; Assay Development, Allen Institute for Cell Science, Seattle, WA, 98109, United States
| | - R Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States.
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45
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Small-Vessel Vasculopathy Due to Aberrant Autophagy in LAMP-2 Deficiency. Sci Rep 2018; 8:3326. [PMID: 29463847 PMCID: PMC5820257 DOI: 10.1038/s41598-018-21602-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 02/06/2018] [Indexed: 02/02/2023] Open
Abstract
Lysosomal associated membrane protein 2 (LAMP2) is physiologically implicated in autophagy. A genetic LAMP2 defect causes Danon disease, which consists of two major phenotypes of myopathy and cardiomyopathy. In addition, arteriopathy may manifest on rare occasions but the pathological basis remains unknown. We encountered two Danon families that developed small-vessel vasculopathy in the coronary or cerebral arteries. To investigate the underlying mechanisms, we characterized the biological features of LAMP-2–deficient mice and cultured cells. LAMP-2–deficient mice at 9–24 months of age showed medial thickening with luminal stenosis due to proliferation of vascular smooth muscle cells (VSMC) in muscular arteries. Ultrastructural analysis of VSMC revealed various autophagic vacuoles scattered throughout the cytoplasm, suggesting impaired autophagy of long-lived metabolites and degraded organelles (i.e., mitochondria). The VSMC in Lamp2 null mice expressed more vimentin but less α-smooth muscle actin (α-SMA), indicating a switch from contractile to synthetic phenotype. Silencing of LAMP2 in cultured human brain VSMC showed the same phenotypic transition with mitochondrial fragmentation, enhanced mitochondrial respiration, and overproduction of reactive oxygen species (ROS). These findings indicate that LAMP-2 deficiency leads to arterial medial hypertrophy with the phenotypic conversion of VSMC, resulting from age-dependent accumulation of cellular waste generated by aberrant autophagy.
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46
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Abstract
Mitochondria exist in a dynamic state inside mammalian cells. They undergo processes of fusion and fission to adjust their shape according to the different cell needs. Different proteins tightly regulate these dynamics: Opa-1 and Mitofusin-1 and Mitofusin-2 are the main profusion proteins, while Drp1 and its different receptors (Mff, Fis1, MiD49, MiD51) regulate mitochondrial fission. The dynamic nature of the mitochondrial network has become evident and detectable, thanks to recent advances in live imaging video microscopy and to the availability of mitochondria-tagged fluorescent proteins. High-resolution confocal reconstruction of mitochondria over time allows researchers to visualize mitochondria shape changes in living cells, under different experimental conditions. Moreover, in recent years, different techniques in living cells have been developed to study the process of mitochondria fusion in more details. Among them are fluorescence recovery after photobleaching (FRAP) of mitochondria-tagged GFP (mtGFP), use of photoactivatable mtGFP, polyethylene glycol (PEG)-based fusion of mtGFP and mtRFP cells, and Renilla luciferase assay (for population studies). In addition, in combination with imaging, the analysis of the expression levels of the different mitochondria-shaping proteins, along with that of their activation status, represents a powerful tool to investigate potential modulations of the mitochondrial network. Here, we review this aspect and then mention a number of techniques, with particular attention to their relative protocols.
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Affiliation(s)
- Luca Simula
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
- Department of Pediatric Hematology and Oncology, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Silvia Campello
- Department of Biology, University of Rome Tor Vergata, Rome, Italy.
- IRCCS, Fondazione Santa Lucia, Rome, Italy.
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47
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Li X, Jiang M, Lam JWY, Tang BZ, Qu JY. Mitochondrial Imaging with Combined Fluorescence and Stimulated Raman Scattering Microscopy Using a Probe of the Aggregation-Induced Emission Characteristic. J Am Chem Soc 2017; 139:17022-17030. [PMID: 29111701 DOI: 10.1021/jacs.7b06273] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In vivo quantitative measurement of biodistribution plays a critical role in the drug/probe development and diagnosis/treatment process monitoring. In this work, we report a probe, named AIE-SRS-Mito, for imaging mitochondria in live cells via fluorescence (FL) and stimulated Raman scattering (SRS) imaging. The probe features an aggregation-induced emission (AIE) characteristic and possesses an enhanced alkyne Raman peak at 2223 cm-1. The dual-mode imaging of AIE-SRS-Mito for selective mitochondrion-targeting was examined on a homemade FL-SRS microscope system. The detection limit of the probe in the SRS imaging was estimated to be 8.5 μM. Due to the linear concentration dependence of SRS and inertness of the alkyne Raman signal to environmental changes, the intracellular distribution of the probe was studied, showing a local concentration of >2.0 mM in the mitochondria matrix, which was >100-fold higher than the incubation concentration. To the best of our knowledge, this is the first time that the local concentration of AIE molecules inside cells has been measured noninvasively and directly. Also, the nonquenching effect of such AIE molecules in cell imaging has been verified by the positive correlation of FL and SRS signals. Our work will encourage the utilization of SRS microscopy for quantitative characterization of FL probes or other nonfluorescent compounds in living biological systems and the development of FL-SRS dual-mode probes for specific biotargets.
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Affiliation(s)
- Xuesong Li
- Department of Electronic and Computer Engineering, ‡Center of Systems Biology and Human Health, School of Science, and Institute for Advanced Study, and §Department of Chemistry, Hong Kong Branch of the Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Division of Biomedical Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong China
| | - Meijuan Jiang
- Department of Electronic and Computer Engineering, ‡Center of Systems Biology and Human Health, School of Science, and Institute for Advanced Study, and §Department of Chemistry, Hong Kong Branch of the Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Division of Biomedical Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong China
| | - Jacky W Y Lam
- Department of Electronic and Computer Engineering, ‡Center of Systems Biology and Human Health, School of Science, and Institute for Advanced Study, and §Department of Chemistry, Hong Kong Branch of the Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Division of Biomedical Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong China
| | - Ben Zhong Tang
- Department of Electronic and Computer Engineering, ‡Center of Systems Biology and Human Health, School of Science, and Institute for Advanced Study, and §Department of Chemistry, Hong Kong Branch of the Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Division of Biomedical Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong China
| | - Jianan Y Qu
- Department of Electronic and Computer Engineering, ‡Center of Systems Biology and Human Health, School of Science, and Institute for Advanced Study, and §Department of Chemistry, Hong Kong Branch of the Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Division of Biomedical Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong China
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48
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Sarkar S, Malovic E, Harishchandra DS, Ghaisas S, Panicker N, Charli A, Palanisamy BN, Rokad D, Jin H, Anantharam V, Kanthasamy A, Kanthasamy AG. Mitochondrial impairment in microglia amplifies NLRP3 inflammasome proinflammatory signaling in cell culture and animal models of Parkinson's disease. NPJ PARKINSONS DISEASE 2017; 3:30. [PMID: 29057315 PMCID: PMC5645400 DOI: 10.1038/s41531-017-0032-2] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/21/2017] [Accepted: 08/23/2017] [Indexed: 02/06/2023]
Abstract
The NLRP3 inflammasome signaling pathway is a major contributor to the neuroinflammatory process in the central nervous system. Oxidative stress and mitochondrial dysfunction are key pathophysiological processes of many chronic neurodegenerative diseases, including Parkinson’s disease (PD). However, the inter-relationship between mitochondrial defects and neuroinflammation is not well understood. In the present study, we show that impaired mitochondrial function can augment the NLRP3 inflammasome-driven proinflammatory cascade in microglia. Primary mouse microglia treated with the common inflammogen LPS increased NLRP3 and pro-IL-1β expression. Interestingly, exposure of LPS-primed microglial cells to the mitochondrial complex-I inhibitory pesticides rotenone and tebufenpyrad specifically potentiated the NLRP3 induction, ASC speck formation and pro-IL-1β processing to IL-1β in a dose-dependent manner, indicating that mitochondrial impairment heightened the NLRP3 inflammasome-mediated proinflammatory response in microglia. The neurotoxic pesticide-induced NLRP3 inflammasome activation was accompanied by bioenergetic defects and lysosomal dysfunction in microglia. Furthermore, the pesticides enhanced mitochondrial ROS generation in primary microglia, while amelioration of mitochondria-derived ROS by the mitochondria-targeted antioxidant mito-apocynin completely abolished IL-1β release, indicating mitochondrial ROS drives potentiation of the NLRP3 inflammasome in microglia. Exposure to conditioned media obtained from mitochondrial inhibitor-treated, LPS-primed microglial cells, but not unprimed cells, induced dopaminergic neurodegeneration in cultured primary mesencephalic and human dopaminergic neuronal cells (LUHMES). Notably, our in vivo results with chronic rotenone rodent models of PD further support the activation of proinflammatory NLRP3 inflammasome signaling due to mitochondrial dysfunction. Collectively, our results demonstrate that mitochondrial impairment in microglia can amplify NLRP3 inflammasome signaling, which augments the dopaminergic neurodegenerative process. A team of American researchers demonstrate that disruption of mitochondria in microglia contributes to inflammation and neurodegeneration. Anumantha G. Kanthasamy at Iowa State University in Ames, IA and colleagues examined the effect of pesticides known to impair mitochondrial function on proinflammatory signaling pathways in microglia, the brain’s immune cells. They found that both rotenone and tebufenpyrad specifically stimulated the NLRP3 inflammasome, a multi-protein complex implicated in neuroinflammatory processes. The pesticide-treated microglia were able to cause more damage to neuronal cells than the untreated ones, indicating that mitochondrial dysfunction in microglia augments neurodegeneration. The authors also show that in rodents chronically exposed to rotenone, which causes many of the features of Parkinson’s disease (PD), the NLRP3 inflammasome is activated. These findings contribute to better understand the mechanisms driving chronic neuroinflammation in PD.
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Affiliation(s)
- Souvarish Sarkar
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA
| | - Emir Malovic
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA
| | - Dilshan S Harishchandra
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA.,Present Address: Perelman School of Medicine, Abramson Family Cancer Research Institute, University of Pennsylvania, 421 Curie Boulevard, 642 BRB II/III, Philadelphia, PA 19104 USA
| | - Shivani Ghaisas
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA.,Present Address: Perelman School of Medicine, Abramson Family Cancer Research Institute, University of Pennsylvania, 421 Curie Boulevard, 642 BRB II/III, Philadelphia, PA 19104 USA
| | - Nikhil Panicker
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA.,Present Address: Institute for Cell Engineering, The Johns Hopkins School of Medicine, 733 North Broadway, Baltimore, MD 21210 USA
| | - Adhithiya Charli
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA
| | | | - Dharmin Rokad
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA
| | - Huajun Jin
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA
| | | | - Arthi Kanthasamy
- Department of Biomedical Science, Iowa State University, Ames, IA 50011 USA
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49
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Mukherjee R, Majumder P, Chakrabarti O. MGRN1-mediated ubiquitination of α-tubulin regulates microtubule dynamics and intracellular transport. Traffic 2017; 18:791-807. [PMID: 28902452 DOI: 10.1111/tra.12527] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 09/01/2017] [Accepted: 09/06/2017] [Indexed: 12/26/2022]
Abstract
MGRN1-mediated ubiquitination of α-tubulin regulates microtubule stability and mitotic spindle positioning in mitotic cells. This study elucidates the effect of MGRN1-mediated ubiquitination of α-tubulin in interphase cells. Here, we show that MGRN1-mediated ubiquitination regulates dynamics of EB1-labeled plus ends of microtubules. Intracellular transport of mitochondria and endosomes are affected in cultured cells where functional MGRN1 is depleted. Defects in microtubule-dependent organellar transport are evident in cells where noncanonical K6-mediated ubiquitination of α-tubulin by MGRN1 is compromised. Loss of MGRN1 has been previously correlated with late-onset spongiform neurodegeneration. Mislocalised cytosolically exposed PrP (Ctm PrP) interacts with MGRN1 leading to its loss of function. Expression of Ctm PrP generating mutants of PrP[PrP(A117V) and PrP(KHII)] lead to decrease in MGRN1-mediated ubiquitination of α-tubulin and intracellular transport defects. Brain lysates from PrP(A117V) transgenic mice also indicate loss of tubulin polymerization as compared to non-transgenic controls. Depletion of MGRN1 activity may hamper physiologically important processes like mitochondrial movement in neuronal processes and intracellular transport of ligands through the endosomal pathway thereby contributing to the pathogenesis of neurodegeneration in certain types of prion diseases.
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Affiliation(s)
- Rukmini Mukherjee
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
| | - Priyanka Majumder
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
| | - Oishee Chakrabarti
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
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50
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Kwon YJ, Guha S, Tuluc F, Falk MJ. High-throughput BioSorter quantification of relative mitochondrial content and membrane potential in living Caenorhabditis elegans. Mitochondrion 2017; 40:42-50. [PMID: 28986305 DOI: 10.1016/j.mito.2017.09.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 09/07/2017] [Accepted: 09/13/2017] [Indexed: 12/26/2022]
Abstract
Mitochondrial respiratory chain disease is caused by a wide range of individually rare genetic disorders that impair cellular energy metabolism. While fluorescence microscopy analysis of nematodes fed MitoTracker Green (MTG) and tetramethylrhodamine ethyl ester (TMRE) can reliably quantify relative mitochondrial density and membrane potential, respectively, in C. elegans models of mitochondrial dysfunction, it is a tedious process with limitations in the number and age of animals that can be studied. A novel, large particle, flow cytometry-based method reported here accelerates and automates the relative quantitation of mitochondrial physiology in nematode populations. Relative fluorescence profiles of nematode populations co-labeled with MTG and TMRE were obtained and analyzed by BioSorter (Union Biometrica). Variables tested included genetic mutation (wild-type N2 Bristol versus nuclear-encoded respiratory chain complex I mutant gas-1(fc21) worms), animal age (day 1 versus day 4 adults), classical respiratory chain inhibitor and uncoupler effects (oligomycin, FCCP), and pharmacologic therapy duration (24h versus 96h treatments with glucose or nicotinic acid). A custom MATLAB script, which can be run on any computer with MATLAB runtime, was written to automatically quantify and analyze results in large animal populations. BioSorter analysis independently validated relative MTG and TMRE changes that we had previously performed by fluorescence microscopy in a variety of experimental conditions, with notably greater animal population sizes and substantially reduced experimental time. Older, fragile animal populations that are difficult to study by microscopy approaches were readily amenable to analysis with the BioSorter method. Overall, this high-throughput method enables efficient relative quantitation of in vivo mitochondrial physiology over time in a living animal in response to gene mutations and candidate therapies, which can be used to accelerate the translation of basic research into optimization of clinical therapies for mitochondrial disease.
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Affiliation(s)
- Young Joon Kwon
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, United States.
| | - Sujay Guha
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, United States.
| | - Florin Tuluc
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, United States; Division of Allergy and Immunology and Flow Cytometry Core Laboratory, Children's Hospital of Philadelphia, Philadelphia, PA, United States.
| | - Marni J Falk
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, United States; Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States.
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