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Vue Z, Vang C, Wanjalla CN, Marshall AG, Neikirk K, Stephens D, Perales S, Garza-Lopez E, Beasley HK, Kirabo A, Doe YJ, Campbell D, Fears L, Alghanem A, Scudese E, Owens B, Morton DJ, Williams CR, Conley Z, Antentor H. A workshop to enrich physiological understanding through hands-on learning about mitochondria-endoplasmic reticulum contact sites. ADVANCES IN PHYSIOLOGY EDUCATION 2024; 48:808-817. [PMID: 39236104 DOI: 10.1152/advan.00271.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 07/03/2024] [Accepted: 08/15/2024] [Indexed: 09/07/2024]
Abstract
Physiology is an important field for students to gain a better understanding of biological mechanisms. Yet, many students often find it difficult to learn from lectures, resulting in poor retention. Here, we utilize a learning workshop model to teach students at different levels ranging from middle school to undergraduate. We specifically designed a workshop to teach students about mitochondria-endoplasmic reticulum contact (MERC) sites. The workshop was implemented for middle school students in a laboratory setting that incorporated a pretest to gauge prior knowledge, instructional time, hands-on activities, interactive learning from experts, and a posttest. We observed that the students remained engaged during the session of interactive methods, teamed with their peers to complete tasks, and delighted in the experience. Implications for the design of future physiological workshops are further offered.NEW & NOTEWORTHY This manuscript offers a design for a workshop that utilizes blended learning to engage middle school, high school, and undergraduate students while teaching them about mitochondria-endoplasmic reticulum contact sites.
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Affiliation(s)
- Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Chia Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Celestine N Wanjalla
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Dominique Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Sulema Perales
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Heather K Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Yelena Janumyan Doe
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Desmond Campbell
- Collaborative for STEM Education and Outreach, Department of Teaching and Learning, Vanderbilt University, Nashville, Tennessee, United States
| | - Letimicia Fears
- Collaborative for STEM Education and Outreach, Department of Teaching and Learning, Vanderbilt University, Nashville, Tennessee, United States
| | - Ahmad Alghanem
- King Abdullah International Medical Research Center (KAIMRC), Ali Al Arini, Ar Rimayah, Riyadh, Saudi Arabia
| | - Estevão Scudese
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Sport Sciences and Exercise Laboratory (LaCEE), Catholic University of Petrópolis (UCP), Petrópolis, Brazil
| | - Beverly Owens
- Department of Chemistry, Cleveland Early College High School, Shelby, North Carolina, United States
| | - Derrick J Morton
- Department of Biomedical Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, California, United States
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States
| | - Clintoria R Williams
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio, United States
| | - Zachary Conley
- Collaborative for STEM Education and Outreach, Department of Teaching and Learning, Vanderbilt University, Nashville, Tennessee, United States
| | - Hinton Antentor
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
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Raby A, Missiroli S, Sanatine P, Langui D, Pansiot J, Beaude N, Vezzana L, Saleh R, Marinello M, Laforge M, Pinton P, Buj-Bello A, Burgo A. Spastin regulates ER-mitochondrial contact sites and mitochondrial homeostasis. iScience 2024; 27:110683. [PMID: 39252960 PMCID: PMC11382127 DOI: 10.1016/j.isci.2024.110683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 05/20/2024] [Accepted: 08/05/2024] [Indexed: 09/11/2024] Open
Abstract
Mitochondria-endoplasmic reticulum (ER) contact sites (MERCs) emerged to play critical roles in numerous cellular processes, and their dysregulation has been associated to neurodegenerative disorders. Mutations in the SPG4 gene coding for spastin are among the main causes of hereditary spastic paraplegia (HSP). Spastin binds and severs microtubules, and the long isoform of this protein, namely M1, spans the outer leaflet of ER membrane where it interacts with other ER-HSP proteins. Here, we showed that overexpressed M1 spastin localizes in ER-mitochondria intersections and that endogenous spastin accumulates in MERCs. We demonstrated in different cellular models that downregulation of spastin enhances the number of MERCs, alters mitochondrial morphology, and impairs ER and mitochondrial calcium homeostasis. These effects are associated with reduced mitochondrial membrane potential, oxygen species levels, and oxidative metabolism. These findings extend our knowledge on the role of spastin in the ER and suggest MERCs deregulation as potential causes of SPG4-HSP disease.
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Affiliation(s)
- Amelie Raby
- Genethon, 91000 Evry, France
- Université Paris-Saclay, University Evry, Inserm, Genethon, Integrare Research Unit UMR_S951, 91000 Evry, France
| | - Sonia Missiroli
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, and Technopole of Ferrara, Laboratory for Advanced Therapies (LTTA), 44121 Ferrara, Italy
| | | | - Dominique Langui
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm U1127, CNRS, APHP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Julien Pansiot
- Université Paris Cité, NeuroDiderot, Inserm, 75019 Paris, France
| | - Nissai Beaude
- Genethon, 91000 Evry, France
- Université Paris-Saclay, University Evry, Inserm, Genethon, Integrare Research Unit UMR_S951, 91000 Evry, France
| | - Lucie Vezzana
- Genethon, 91000 Evry, France
- Université Paris-Saclay, University Evry, Inserm, Genethon, Integrare Research Unit UMR_S951, 91000 Evry, France
| | - Rachelle Saleh
- Université Paris Cité, NeuroDiderot, Inserm, 75019 Paris, France
| | - Martina Marinello
- Genethon, 91000 Evry, France
- Université Paris-Saclay, University Evry, Inserm, Genethon, Integrare Research Unit UMR_S951, 91000 Evry, France
| | - Mireille Laforge
- Université Paris Cité, NeuroDiderot, Inserm, 75019 Paris, France
| | - Paolo Pinton
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, and Technopole of Ferrara, Laboratory for Advanced Therapies (LTTA), 44121 Ferrara, Italy
| | - Ana Buj-Bello
- Genethon, 91000 Evry, France
- Université Paris-Saclay, University Evry, Inserm, Genethon, Integrare Research Unit UMR_S951, 91000 Evry, France
| | - Andrea Burgo
- Genethon, 91000 Evry, France
- Université Paris-Saclay, University Evry, Inserm, Genethon, Integrare Research Unit UMR_S951, 91000 Evry, France
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3
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Guo M, Liu R, Zhang F, Qu J, Yang Y, Li X. A new perspective on liver diseases: Focusing on the mitochondria-associated endoplasmic reticulum membranes. Pharmacol Res 2024; 208:107409. [PMID: 39284429 DOI: 10.1016/j.phrs.2024.107409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 08/29/2024] [Accepted: 09/10/2024] [Indexed: 09/19/2024]
Abstract
The pathogenesis of liver diseases is multifaceted and intricate, posing a persistent global public health challenge with limited therapeutic options. Therefore, further research into liver diseases is imperative for better comprehension and advancement in treatment strategies. Numerous studies have confirmed the endoplasmic reticulum (ER) and mitochondria as key organelles driving liver diseases. Notably, the mitochondrial-associated ER membranes (MAMs) establish a physical and functional connection between the ER and mitochondria, highlighting the importance of inter-organelle communication in maintaining their functional homeostasis. This review delves into the intricate architecture and regulative mechanism of the integrated MAM that facilitate the physiological transfer of signals and substances between organelles. Additionally, we also provide a detailed overview regarding the varied pathogenic roles of malfunctioning MAM in liver diseases, focusing on its involvement in the progression of ER stress and mitochondrial dysfunction, the regulation of mitochondrial dynamics and Ca2+ transfer, as well as the disruption of lipid and glucose homeostasis. Furthermore, the current challenges and prospects associated with MAM in liver disease research are thoroughly discussed. In conclusion, elucidating the specific structure and function of MAM in different liver diseases may pave the way for novel therapeutic strategies.
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Affiliation(s)
- Mengyu Guo
- School of Life Sciences, Beijing University of Chinese Medicine, 100029, China
| | - Runping Liu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, 100029, China
| | - Fukun Zhang
- School of Life Sciences, Beijing University of Chinese Medicine, 100029, China
| | - Jiaorong Qu
- School of Life Sciences, Beijing University of Chinese Medicine, 100029, China
| | - Yun Yang
- School of Life Sciences, Beijing University of Chinese Medicine, 100029, China
| | - Xiaojiaoyang Li
- School of Life Sciences, Beijing University of Chinese Medicine, 100029, China.
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4
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Yamada K, St Croix C, Stolz DB, Tyurina YY, Tyurin VA, Bradley LR, Kapralov AA, Deng Y, Zhou X, Wei Q, Liao B, Fukuda N, Sullivan M, Trudeau J, Ray A, Kagan VE, Zhao J, Wenzel SE. Compartmentalized mitochondrial ferroptosis converges with optineurin-mediated mitophagy to impact airway epithelial cell phenotypes and asthma outcomes. Nat Commun 2024; 15:5818. [PMID: 38987265 PMCID: PMC11237105 DOI: 10.1038/s41467-024-50222-2] [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: 07/11/2023] [Accepted: 07/03/2024] [Indexed: 07/12/2024] Open
Abstract
A stable mitochondrial pool is crucial for healthy cell function and survival. Altered redox biology can adversely affect mitochondria through induction of a variety of cell death and survival pathways, yet the understanding of mitochondria and their dysfunction in primary human cells and in specific disease states, including asthma, is modest. Ferroptosis is traditionally considered an iron dependent, hydroperoxy-phospholipid executed process, which induces cytosolic and mitochondrial damage to drive programmed cell death. However, in this report we identify a lipoxygenase orchestrated, compartmentally-targeted ferroptosis-associated peroxidation process which occurs in a subpopulation of dysfunctional mitochondria, without promoting cell death. Rather, this mitochondrial peroxidation process tightly couples with PTEN-induced kinase (PINK)-1(PINK1)-Parkin-Optineurin mediated mitophagy in an effort to preserve the pool of functional mitochondria and prevent cell death. These combined peroxidation processes lead to altered epithelial cell phenotypes and loss of ciliated cells which associate with worsened asthma severity. Ferroptosis-targeted interventions of this process could preserve healthy mitochondria, reverse cell phenotypic changes and improve disease outcomes.
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Affiliation(s)
- Kazuhiro Yamada
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Department of Respiratory Medicine, Graduate School of Medicine, Osaka Metropolitan University, Osaka, 545-8585, Japan
| | - Claudette St Croix
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Donna B Stolz
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Yulia Y Tyurina
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Vladimir A Tyurin
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Laura R Bradley
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Alexander A Kapralov
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Yanhan Deng
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Department of Rheumatology and Immunology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiuxia Zhou
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Qi Wei
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Bo Liao
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Department of Otolaryngology-Head & Neck Surgery, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Nobuhiko Fukuda
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan
| | - Mara Sullivan
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - John Trudeau
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Anuradha Ray
- Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Valerian E Kagan
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Jinming Zhao
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
| | - Sally E Wenzel
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
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5
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Elwakiel A, Mathew A, Isermann B. The role of endoplasmic reticulum-mitochondria-associated membranes in diabetic kidney disease. Cardiovasc Res 2024; 119:2875-2883. [PMID: 38367274 DOI: 10.1093/cvr/cvad190] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/03/2023] [Accepted: 07/07/2023] [Indexed: 02/19/2024] Open
Abstract
Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide. The pathomechanisms of DKD are multifactorial, yet haemodynamic and metabolic changes in the early stages of the disease appear to predispose towards irreversible functional loss and histopathological changes. Recent studies highlight the importance of endoplasmic reticulum-mitochondria-associated membranes (ER-MAMs), structures conveying important cellular homeostatic and metabolic effects, in the pathology of DKD. Disruption of ER-MAM integrity in diabetic kidneys is associated with DKD progression, but the regulation of ER-MAMs and their pathogenic contribution remain largely unknown. Exploring the cell-specific components and dynamic changes of ER-MAMs in diabetic kidneys may lead to the identification of new approaches to detect and stratify diabetic patients with DKD. In addition, these insights may lead to novel therapeutic approaches to target and/or reverse disease progression. In this review, we discuss the association of ER-MAMs with key pathomechanisms driving DKD such as insulin resistance, dyslipidaemia, ER stress, and inflammasome activation and the importance of further exploration of ER-MAMs as diagnostic and therapeutic targets in DKD.
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Affiliation(s)
- Ahmed Elwakiel
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Paul-List-Straße 13/15, 04103 Leipzig, Germany
| | - Akash Mathew
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Paul-List-Straße 13/15, 04103 Leipzig, Germany
| | - Berend Isermann
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Paul-List-Straße 13/15, 04103 Leipzig, Germany
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6
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Hall MR, Kunjumon TK, Ghosh PP, Currie L, Mathur J. Organelle Interactions in Plant Cells. Results Probl Cell Differ 2024; 73:43-69. [PMID: 39242374 DOI: 10.1007/978-3-031-62036-2_3] [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] [Indexed: 09/09/2024]
Abstract
The sequestration of enzymes and associated processes into sub-cellular domains, called organelles, is considered a defining feature of eukaryotic cells. However, what leads to specific outcomes and allows a eukaryotic cell to function singularly is the interactivity and exchanges between discrete organelles. Our ability to observe and assess sub-cellular interactions in living plant cells has expanded greatly following the creation of fluorescent fusion proteins targeted to different organelles. Notably, organelle interactivity changes quickly in response to stress and reverts to a normal less interactive state as homeostasis is re-established. Using key observations of some of the organelles present in a plant cell, this chapter provides a brief overview of our present understanding of organelle interactions in plant cells.
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Affiliation(s)
- Maya-Renee Hall
- Laboratory of Plant Development & Interactions, Department of Molecular & Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Thomas Kadanthottu Kunjumon
- Laboratory of Plant Development & Interactions, Department of Molecular & Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Puja Puspa Ghosh
- Laboratory of Plant Development & Interactions, Department of Molecular & Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Laura Currie
- Laboratory of Plant Development & Interactions, Department of Molecular & Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Jaideep Mathur
- Laboratory of Plant Development & Interactions, Department of Molecular & Cellular Biology, University of Guelph, Guelph, ON, Canada.
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7
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Neikirk K, Lopez EG, Marshall AG, Alghanem A, Krystofiak E, Kula B, Smith N, Shao J, Katti P, Hinton A. Call to action to properly utilize electron microscopy to measure organelles to monitor disease. Eur J Cell Biol 2023; 102:151365. [PMID: 37864884 DOI: 10.1016/j.ejcb.2023.151365] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/14/2023] [Accepted: 10/15/2023] [Indexed: 10/23/2023] Open
Abstract
This review provides an overview of the current methods for quantifying mitochondrial ultrastructure, including cristae morphology, mitochondrial contact sites, and recycling machinery and a guide to utilizing electron microscopy to effectively measure these organelles. Quantitative analysis of mitochondrial ultrastructure is essential for understanding mitochondrial biology and developing therapeutic strategies for mitochondrial-related diseases. Techniques such as transmission electron microscopy (TEM) and serial block face-scanning electron microscopy, as well as how they can be combined with other techniques including confocal microscopy, super-resolution microscopy, and correlative light and electron microscopy are discussed. Beyond their limitations and challenges, we also offer specific magnifications that may be best suited for TEM analysis of mitochondrial, endoplasmic reticulum, and recycling machinery. Finally, perspectives on future quantification methods are offered.
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Affiliation(s)
- Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Edgar-Garza Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Ahmad Alghanem
- King Abdullah International Medical Research Center (KAIMRC), Ali Al Arini, Ar Rimayah, Riyadh 11481, Saudi Arabia
| | - Evan Krystofiak
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Bartosz Kula
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester 14642, USA
| | - Nathan Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester 14642, USA
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, USA
| | - Prasanna Katti
- National Heart, Lung and Blood Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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8
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Stephens DC, Crabtree A, Beasley HK, Garza-Lopez E, Neikirk K, Mungai M, Vang L, Vue Z, Vue N, Marshall AG, Turner K, Shao J, Murray S, Gaddy JA, Wanjalla C, Davis J, Damo S, Hinton AO. Optimizing In Situ Proximity Ligation Assays for Mitochondria, ER, or MERC Markers in Skeletal Muscle Tissue and Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.20.541599. [PMID: 37292700 PMCID: PMC10245739 DOI: 10.1101/2023.05.20.541599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Proximity ligation assays (PLA) use specific antibodies to detect endogenous protein-protein interactions. PLA is a highly useful biochemical technique that allows two proteins within close proximity to be visualized with fluorescent probes amplified by PCR. While this technique has gained prominence, the use of PLA in mouse skeletal muscle (SkM) is novel. In this article, we discuss how the PLA method can be used in SkM to study the protein-protein interactions within mitochondria-endoplasmic reticulum contact sites (MERCs).
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Affiliation(s)
- Dominique C. Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Amber Crabtree
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Heather K. Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Margaret Mungai
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Neng Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Andrea G. Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Kyrin Turner
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Sandra Murray
- Department of Cell Biology, College of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Jennifer A. Gaddy
- Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, 37232 USA
- Tennessee Valley Healthcare Systems, U.S. Department of Veterans Affairs, Nashville, Tennessee, 37212 USA
| | - Celestine Wanjalla
- Vanderbilt University Medical Center: Department of Medicine, Division of Infectious Disease, Nashville, TN, USA
| | - Jamaine Davis
- Department of Biochemistry and Cancer Biology. Meharry Medical College, Nashville, TN, 37208, USA
| | - Steven Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Antentor O. Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
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9
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Panes-Fernandez J, Godoy PA, Gavilan J, Ramírez-Molina O, Burgos CF, Marileo A, Flores-Núñez O, Castro PA, Moraga-Cid G, Yévenes GE, Muñoz-Montesino C, Fuentealba J. TG2 promotes amyloid beta aggregates: Impact on ER-mitochondria crosstalk, calcium homeostasis and synaptic function in Alzheimer’s disease. Biomed Pharmacother 2023; 162:114596. [PMID: 36989728 DOI: 10.1016/j.biopha.2023.114596] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/20/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by cognitive impairment that increasingly affects the elderly. AD's main features have been related to cellular and molecular events, including the aberrant aggregation of the amyloid beta peptide (Aβ), Ca2+ dyshomeostasis, and increased mitochondria-associated membranes (MAMs). Transglutaminase type 2 (TG2) is a ubiquitous enzyme whose primary role is the Ca2+-dependent proteins transamidation, including the Aβ peptide. TG2 activity has been closely related to cellular damage and death. We detected increased TG2 levels in neuronal cells treated with Aβ oligomers (AβOs) and hippocampal slices from J20 mice using cellular and molecular approaches. In this work, we characterized the capacity of TG2 to interact and promote Aβ toxic aggregates (AβTG2). AβTG2 induced an acute increase in intracellular Ca2+, miniature currents, and hiperexcitability, consistent with an increased mitochondrial Ca2+ overload, IP3R-VDAC tethering, and mitochondria-endoplasmic reticulum contacts (MERCs). AβTG2 also decreased neuronal viability and excitatory postsynaptic currents, reinforcing the idea of synaptic failure associated with MAMs dysregulation mediated by TG2. Z-DON treatment, TG2 inhibitor, reduced calcium overload, mitochondrial membrane potential loss, and synaptic failure, indicating an involvement of TG2 in a toxic cycle which increases Aβ aggregation, Ca2+ overload, and MAMs upregulation. These data provide novel information regarding the role TG2 plays in synaptic function and contribute additional evidence to support the further development of TG2 inhibitors as a disease-modifying strategy for AD.
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10
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Kim S, Coukos R, Gao F, Krainc D. Dysregulation of organelle membrane contact sites in neurological diseases. Neuron 2022; 110:2386-2408. [PMID: 35561676 PMCID: PMC9357093 DOI: 10.1016/j.neuron.2022.04.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/21/2022] [Accepted: 04/18/2022] [Indexed: 10/18/2022]
Abstract
The defining evolutionary feature of eukaryotic cells is the emergence of membrane-bound organelles. Compartmentalization allows each organelle to maintain a spatially, physically, and chemically distinct environment, which greatly bolsters individual organelle function. However, the activities of each organelle must be balanced and are interdependent for cellular homeostasis. Therefore, properly regulated interactions between organelles, either physically or functionally, remain critical for overall cellular health and behavior. In particular, neuronal homeostasis depends heavily on the proper regulation of organelle function and cross talk, and deficits in these functions are frequently associated with diseases. In this review, we examine the emerging role of organelle contacts in neurological diseases and discuss how the disruption of contacts contributes to disease pathogenesis. Understanding the molecular mechanisms underlying the formation and regulation of organelle contacts will broaden our knowledge of their role in health and disease, laying the groundwork for the development of new therapies targeting interorganelle cross talk and function.
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Affiliation(s)
- Soojin Kim
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Robert Coukos
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Fanding Gao
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL 60611, USA.
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Zaman M, Shutt TE. The Role of Impaired Mitochondrial Dynamics in MFN2-Mediated Pathology. Front Cell Dev Biol 2022; 10:858286. [PMID: 35399520 PMCID: PMC8989266 DOI: 10.3389/fcell.2022.858286] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/07/2022] [Indexed: 12/17/2022] Open
Abstract
The Mitofusin 2 protein (MFN2), encoded by the MFN2 gene, was first described for its role in mediating mitochondrial fusion. However, MFN2 is now recognized to play additional roles in mitochondrial autophagy (mitophagy), mitochondrial motility, lipid transfer, and as a tether to other organelles including the endoplasmic reticulum (ER) and lipid droplets. The tethering role of MFN2 is an important mediator of mitochondrial-ER contact sites (MERCs), which themselves have many important functions that regulate mitochondria, including calcium homeostasis and lipid metabolism. Exemplifying the importance of MFN2, pathogenic variants in MFN2 are established to cause the peripheral neuropathy Charcot-Marie-Tooth Disease Subtype 2A (CMT2A). However, the mechanistic basis for disease is not clear. Moreover, additional pathogenic phenotypes such as lipomatosis, distal myopathy, optic atrophy, and hearing loss, can also sometimes be present in patients with CMT2A. Given these variable patient phenotypes, and the many cellular roles played by MFN2, the mechanistic underpinnings of the cellular impairments by which MFN2 dysfunction leads to disease are likely to be complex. Here, we will review what is known about the various functions of MFN2 that are impaired by pathogenic variants causing CMT2A, with a specific emphasis on the ties between MFN2 variants and MERCs.
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Affiliation(s)
- Mashiat Zaman
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute (ACHRI), Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Timothy E Shutt
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute (ACHRI), Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Department of Medical Genetics, University of Calgary, Calgary, AB, Canada
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Poggio E, Brini M, Calì T. Get Closer to the World of Contact Sites: A Beginner's Guide to Proximity-Driven Fluorescent Probes. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2022; 5:25152564221135748. [PMID: 37366505 PMCID: PMC10243574 DOI: 10.1177/25152564221135748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
To maintain cellular homeostasis and to coordinate the proper response to a specific stimulus, information must be integrated throughout the cell in a well-organized network, in which organelles are the crucial nodes and membrane contact sites are the main edges. Membrane contact sites are the cellular subdomains where two or more organelles come into close apposition and interact with each other. Even though many inter-organelle contacts have been identified, most of them are still not fully characterized, therefore their study is an appealing and expanding field of research. Thanks to significant technological progress, many tools are now available or are in rapid development, making it difficult to choose which one is the most suitable for answering a specific biological question. Here we distinguish two different experimental approaches for studying inter-organelle contact sites. The first one aims to morphologically characterize the sites of membrane contact and to identify the molecular players involved, relying mainly on the application of biochemical and electron microscopy (EM)-related methods. The second approach aims to understand the functional importance of a specific contact, focusing on spatio-temporal details. For this purpose, proximity-driven fluorescent probes are the experimental tools of choice, since they allow the monitoring and quantification of membrane contact sites and their dynamics in living cells under different cellular conditions or upon different stimuli. In this review, we focus on these tools with the purpose of highlighting their great versatility and how they can be applied in the study of membrane contacts. We will extensively describe all the different types of proximity-driven fluorescent tools, discussing their benefits and drawbacks, ultimately providing some suggestions to choose and apply the appropriate methods on a case-to-case basis and to obtain the best experimental outcomes.
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Affiliation(s)
- Elena Poggio
- Department of Biology (DiBio), University of
Padova, Padova, Italy
| | - Marisa Brini
- Department of Biology (DiBio), University of
Padova, Padova, Italy
- Study Center for Neurodegeneration (CESNE),
University of Padova, Padova, Italy
| | - Tito Calì
- Study Center for Neurodegeneration (CESNE),
University of Padova, Padova, Italy
- Department of Biomedical Sciences (DSB),
University of Padova, Padova, Italy
- Padova Neuroscience Center (PNC), University
of Padova, Padova, Italy
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