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He W, He W, Chen X, Zeng L, Zeng L, Liu Y, He P, Sun Z. Mitochondrial elongation confers protection against doxorubicin-induced cardiotoxicity. Biochem Pharmacol 2024; 229:116495. [PMID: 39159875 DOI: 10.1016/j.bcp.2024.116495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 08/14/2024] [Accepted: 08/16/2024] [Indexed: 08/21/2024]
Abstract
Doxorubicin (DOX)-induced cardiac damage remains a leading cause of death amongst cancer survivors. DOX-induced cardiotoxicity (DIC) is mediated by disturbed mitochondrial dynamics, but it remains debated that the mechanisms by which DOX disrupted equilibrium between mitochondrial fission and fusion. In the present study, we observed that DOX induced mitochondrial elongation in multiple cardiovascular cell lines. Mechanically, DOX not only downregulated the mitochondrial fusion proteins including Mitofusin 1/2 (MFN1/2) and Optic atrophy 1 (OPA1), but also induced lower motility of dynamin-related protein 1(Drp1) and its phosphorylation on 637 serine, which could inhibit mitochondrial fission. Interestingly, DOX failed to induce mitochondrial elongation in cardiomyocytes co-treated with protein kinase A (PKA) inhibitor H89 or expressing phosphodeficient Drp1-S637A variants. Besides, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) was able to blocked the mitochondrial elongation induced by DOX treatment, which could be phenocopied by OPA1 knockdown. Therefore, we speculated that DOX inhibited mitochondrial fission and fusion simultaneously, yet enabled mitochondrial fusion dominate the mitochondrial dynamics, resulting in mitochondrial elongation as the main manifestation. Notably, blocking mitochondrial elongation by inhibiting Drp1-S637 phosphorylation or OPA1 knockdown aggravated DOX-induced cardiomyocytes death. Based on these results, we propose a novel mechanistic model that DOX-induced mitochondrial elongation is attributed to the equilibrium disturbance of mitochondrial dynamics, which serves as an adaptive response and confers protection against DIC.
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Affiliation(s)
- Weibin He
- Department of Cardiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510000 Guangzhou, China; Department of Cardiology, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Guangdong Cardiovascular Institute, 510000 Guangzhou, China
| | - Wenlong He
- Department of Cardiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510000 Guangzhou, China; Department of Cardiology, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Guangdong Cardiovascular Institute, 510000 Guangzhou, China
| | - Xiaopan Chen
- Department of Cardiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510000 Guangzhou, China
| | - Lin Zeng
- Department of Cardiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510000 Guangzhou, China; Department of Cardiology, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Guangdong Cardiovascular Institute, 510000 Guangzhou, China
| | - Lihuan Zeng
- Department of Cardiology, Department of Guangdong Provincial People's Hospital's Nanhai Hospital, The Second Hospital of Nanhai District Foshan City, Foshan, China
| | - Yuanhui Liu
- Department of Cardiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510000 Guangzhou, China; Department of Cardiology, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Guangdong Cardiovascular Institute, 510000 Guangzhou, China.
| | - Pengcheng He
- Department of Cardiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510000 Guangzhou, China; Department of Cardiology, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Guangdong Cardiovascular Institute, 510000 Guangzhou, China; Department of Cardiology, Heyuan People's Hospital, 517000 Heyuan, China.
| | - Zhongchan Sun
- Department of Cardiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510000 Guangzhou, China; Department of Cardiology, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Guangdong Cardiovascular Institute, 510000 Guangzhou, China.
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2
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Read TA, Cisterna BA, Skruber K, Ahmadieh S, Liu TM, Vitriol JA, Shi Y, Black JB, Butler MT, Lindamood HL, Lefebvre AE, Cherezova A, Ilatovskaya DV, Bear JE, Weintraub NL, Vitriol EA. The actin binding protein profilin 1 localizes inside mitochondria and is critical for their function. EMBO Rep 2024; 25:3240-3262. [PMID: 39026010 PMCID: PMC11316047 DOI: 10.1038/s44319-024-00209-3] [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: 08/17/2023] [Revised: 06/16/2024] [Accepted: 06/28/2024] [Indexed: 07/20/2024] Open
Abstract
The monomer-binding protein profilin 1 (PFN1) plays a crucial role in actin polymerization. However, mutations in PFN1 are also linked to hereditary amyotrophic lateral sclerosis, resulting in a broad range of cellular pathologies which cannot be explained by its primary function as a cytosolic actin assembly factor. This implies that there are important, undiscovered roles for PFN1 in cellular physiology. Here we screened knockout cells for novel phenotypes associated with PFN1 loss of function and discovered that mitophagy was significantly upregulated. Indeed, despite successful autophagosome formation, fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells accumulate depolarized, dysmorphic mitochondria with altered metabolic properties. Surprisingly, we also discovered that PFN1 is present inside mitochondria and provide evidence that mitochondrial defects associated with PFN1 loss are not caused by reduced actin polymerization in the cytosol. These findings suggest a previously unrecognized role for PFN1 in maintaining mitochondrial integrity and highlight new pathogenic mechanisms that can result from PFN1 dysregulation.
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Affiliation(s)
- Tracy-Ann Read
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA.
| | - Bruno A Cisterna
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kristen Skruber
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - Samah Ahmadieh
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Tatiana M Liu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Josefine A Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Yang Shi
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Department of Population Health Sciences, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Joseph B Black
- Division of Urologic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Mitchell T Butler
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Halli L Lindamood
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | | | - Alena Cherezova
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - James E Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Neal L Weintraub
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Eric A Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA.
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3
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Deshmukh V, Martin JF. SETD3 is a mechanosensitive enzyme that methylates actin on His73 to regulate mitochondrial dynamics and function. J Cell Sci 2024; 137:jcs261268. [PMID: 38896010 PMCID: PMC11304411 DOI: 10.1242/jcs.261268] [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: 04/21/2023] [Accepted: 06/06/2024] [Indexed: 06/21/2024] Open
Abstract
Mitochondria, which act as sensors of metabolic homeostasis and metabolite signaling, form a dynamic intracellular network that continuously changes shape, size and localization to respond to localized cellular energy demands. Mitochondrial dynamics and function depend on interactions with the F-actin cytoskeleton that are poorly understood. Here, we show that SET domain protein 3 (SETD3), a recently described actin histidine methyltransferase, directly methylates actin at histidine-73 and enhances F-actin polymerization on mitochondria. SETD3 is a mechano-sensitive enzyme that is localized on the outer mitochondrial membrane and promotes actin polymerization around mitochondria. SETD3 loss of function leads to diminished F-actin around mitochondria and a decrease in mitochondrial branch length, branch number and mitochondrial movement. Our functional analysis revealed that SETD3 is required for oxidative phosphorylation, and mitochondrial complex I assembly and function. Our data further indicate that SETD3 regulates F-actin formation around mitochondria and is essential for maintaining mitochondrial morphology, movement and function. Finally, we discovered that SETD3 levels are regulated by extracellular matrix (ECM) stiffness and regulate mitochondrial shape in response to changes in ECM stiffness. These findings provide new insight into the mechanism for F-actin polymerization around mitochondria.
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Affiliation(s)
- Vaibhav Deshmukh
- Department of Integrative Physiology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - James F. Martin
- Department of Integrative Physiology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
- Cardiomyocyte Renewal Lab, Texas Heart Institute, 6770 Bertner Avenue, Houston, Texas 77030, USA
- Center for Organ Repair and Renewal, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
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4
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Gatti P, Schiavon C, Manor U, Germain M. Mitochondria- and ER-associated actin are required for mitochondrial fusion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.13.544768. [PMID: 37398222 PMCID: PMC10312652 DOI: 10.1101/2023.06.13.544768] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Mitochondria play a crucial role in the regulation of cellular metabolism and signalling. Mitochondrial activity is modulated by the processes of mitochondrial fission and fusion, which are required to properly balance respiratory and metabolic functions, transfer material between mitochondria, and remove defective mitochondria. Mitochondrial fission occurs at sites of contact between the endoplasmic reticulum (ER) and mitochondria, and is dependent on the formation of actin filaments that drive mitochondrial constriction and the recruitment and activation of the dynamin-related GTPase fission protein DRP1. The requirement for mitochondria- and ER-associated actin filaments in mitochondrial fission remains unclear, and the role of actin in mitochondrial fusion remains entirely unexplored. Here we show that preventing the formation of actin filaments on either mitochondria or the ER disrupts both mitochondrial fission and fusion. We show that fusion but not fission is dependent on Arp2/3, whereas both fission and fusion are dependent on INF2 formin-dependent actin polymerization. We also show that mitochondria-associated actin marks fusion sites prior to the dynamin family GTPase fusion protein MFN2. Together, our work introduces a novel method for perturbing organelle-associated actin filaments, and demonstrates a previously unknown role for actin in mitochondrial fusion.
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Affiliation(s)
- Priya Gatti
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
- Centre d’Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Montréal, Montréal, Québec, Canada
- Réseau Intersectoriel de Recherche en Santé de l’Université du Québec (RISUQ)
| | - Cara Schiavon
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Marc Germain
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
- Centre d’Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Montréal, Montréal, Québec, Canada
- Réseau Intersectoriel de Recherche en Santé de l’Université du Québec (RISUQ)
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5
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Wu K, Shieh JS, Qin L, Guo JJ. Mitochondrial mechanisms in the pathogenesis of chronic inflammatory musculoskeletal disorders. Cell Biosci 2024; 14:76. [PMID: 38849951 PMCID: PMC11162051 DOI: 10.1186/s13578-024-01259-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/29/2024] [Indexed: 06/09/2024] Open
Abstract
Chronic inflammatory musculoskeletal disorders characterized by prolonged muscle inflammation, resulting in enduring pain and diminished functionality, pose significant challenges for the patients. Emerging scientific evidence points to mitochondrial malfunction as a pivotal factor contributing to these ailments. Mitochondria play a critical role in powering skeletal muscle activity, but in the context of persistent inflammation, disruptions in their quantity, configuration, and performance have been well-documented. Various disturbances, encompassing alterations in mitochondrial dynamics (such as fission and fusion), calcium regulation, oxidative stress, biogenesis, and the process of mitophagy, are believed to play a central role in the progression of these disorders. Additionally, unfolded protein responses and the accumulation of fatty acids within muscle cells may adversely affect the internal milieu, impairing the equilibrium of mitochondrial functioning. The structural discrepancies between different mitochondrial subsets namely, intramyofibrillar and subsarcolemmal mitochondria likely impact their metabolic capabilities and susceptibility to inflammatory influences. The release of signals from damaged mitochondria is known to incite inflammatory responses. Intriguingly, migrasomes and extracellular vesicles serve as vehicles for intercellular transfer of mitochondria, aiding in the removal of impaired mitochondria and regulation of inflammation. Viral infections have been implicated in inducing stress on mitochondria. Prolonged dysfunction of these vital organelles sustains oxidative harm, metabolic irregularities, and heightened cytokine release, impeding the body's ability to repair tissues. This review provides a comprehensive analysis of advancements in understanding changes in the intracellular environment, mitochondrial architecture and distribution, biogenesis, dynamics, autophagy, oxidative stress, cytokines associated with mitochondria, vesicular structures, and associated membranes in the context of chronic inflammatory musculoskeletal disorders. Strategies targeting key elements regulating mitochondrial quality exhibit promise in the restoration of mitochondrial function, alleviation of inflammation, and enhancement of overall outcomes.
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Affiliation(s)
- Kailun Wu
- Department of Orthopedics, The Fourth Affiliated Hospital of Soochow University/Suzhou Dushu Lake Hospital, Suzhou, Jiangsu, People's Republic of China
- Department of Orthopedics and Sports Medicine, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China
| | - Ju-Sheng Shieh
- Department of Periodontology, School of Dentistry, Tri-Service General Hospital, National Defense Medical Center, Taipei City, 11490, Taiwan
| | - Ling Qin
- Musculoskeletal Research Laboratory of the Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - Jiong Jiong Guo
- Department of Orthopedics and Sports Medicine, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China.
- MOE China-Europe Sports Medicine Belt and Road Joint Laboratory, Soochow University, Suzhou, Jiangsu, People's Republic of China.
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6
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Coscia SM, Moore AS, Thompson CP, Tirrito CF, Ostap EM, Holzbaur ELF. An interphase actin wave promotes mitochondrial content mixing and organelle homeostasis. Nat Commun 2024; 15:3793. [PMID: 38714822 PMCID: PMC11076292 DOI: 10.1038/s41467-024-48189-1] [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: 05/05/2023] [Accepted: 04/22/2024] [Indexed: 05/10/2024] Open
Abstract
Across the cell cycle, mitochondrial dynamics are regulated by a cycling wave of actin polymerization/depolymerization. In metaphase, this wave induces actin comet tails on mitochondria that propel these organelles to drive spatial mixing, resulting in their equitable inheritance by daughter cells. In contrast, during interphase the cycling actin wave promotes localized mitochondrial fission. Here, we identify the F-actin nucleator/elongator FMNL1 as a positive regulator of the wave. FMNL1-depleted cells exhibit decreased mitochondrial polarization, decreased mitochondrial oxygen consumption, and increased production of reactive oxygen species. Accompanying these changes is a loss of hetero-fusion of wave-fragmented mitochondria. Thus, we propose that the interphase actin wave maintains mitochondrial homeostasis by promoting mitochondrial content mixing. Finally, we investigate the mechanistic basis for the observation that the wave drives mitochondrial motility in metaphase but mitochondrial fission in interphase. Our data indicate that when the force of actin polymerization is resisted by mitochondrial tethering to microtubules, as in interphase, fission results.
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Affiliation(s)
- Stephen M Coscia
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Andrew S Moore
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, USA
| | - Cameron P Thompson
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Christian F Tirrito
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - E Michael Ostap
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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7
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Theodore CJ, Wagner LH, Campellone KG. Autophagosome turnover requires Arp2/3 complex-mediated maintenance of lysosomal integrity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584718. [PMID: 38559247 PMCID: PMC10980047 DOI: 10.1101/2024.03.12.584718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Autophagy is an intracellular degradation process that maintains homeostasis, responds to stress, and plays key roles in the prevention of aging and disease. Autophagosome biogenesis, vesicle rocketing, and autolysosome tubulation are controlled by multiple actin nucleation factors, but the impact of actin assembly on completion of the autophagic pathway is not well understood. Here we studied autophagosome and lysosome remodeling in fibroblasts harboring an inducible knockout (iKO) of the Arp2/3 complex, an essential actin nucleator. Arp2/3 complex ablation resulted in increased basal levels of autophagy receptors and lipidated membrane proteins from the LC3 and GABARAP families. Under both steady-state and starvation conditions, Arp2/3 iKO cells accumulated abnormally high numbers of autolysosomes, suggesting a defect in autophagic flux. The inability of Arp2/3 complex-deficient cells to complete autolysosome degradation and turnover is explained by the presence of damaged, leaky lysosomes. In cells treated with an acute lysosomal membrane-damaging agent, the Arp2/3-activating protein WHAMM is recruited to lysosomes, where Arp2/3 complex-dependent actin assembly is crucial for restoring intact lysosomal structure. These results establish the Arp2/3 complex as a central player late in the canonical autophagy pathway and reveal a new role for the actin nucleation machinery in maintaining lysosomal integrity.
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Affiliation(s)
- Corey J. Theodore
- Department of Molecular and Cell Biology; University of Connecticut, Storrs CT, USA
- Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | - Lianna H. Wagner
- Department of Molecular and Cell Biology; University of Connecticut, Storrs CT, USA
- Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | - Kenneth G. Campellone
- Department of Molecular and Cell Biology; University of Connecticut, Storrs CT, USA
- Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
- Center on Aging, UConn Health; University of Connecticut, Storrs CT, USA
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8
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Zhu Q, Combs ME, Liu J, Bai X, Wang WB, Herring LE, Liu J, Locasale JW, Bowles DE, Gross RT, Pla MM, Mack CP, Taylor JM. GRAF1 integrates PINK1-Parkin signaling and actin dynamics to mediate cardiac mitochondrial homeostasis. Nat Commun 2023; 14:8187. [PMID: 38081847 PMCID: PMC10713658 DOI: 10.1038/s41467-023-43889-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
The serine/threonine kinase, PINK1, and the E3 ubiquitin ligase, Parkin, are known to facilitate LC3-dependent autophagosomal encasement and lysosomal clearance of dysfunctional mitochondria, and defects in this process contribute to a variety of cardiometabolic and neurological diseases. Although recent evidence indicates that dynamic actin remodeling plays an important role in PINK1/Parkin-mediated mitochondrial autophagy (mitophagy), the underlying signaling mechanisms remain unknown. Here, we identify the RhoGAP GRAF1 (Arhgap26) as a PINK1 substrate that regulates mitophagy. GRAF1 promotes the release of damaged mitochondria from F-actin anchors, regulates mitochondrial-associated Arp2/3-mediated actin remodeling and facilitates Parkin-LC3 interactions to enhance mitochondria capture by autophagosomes. Graf1 phosphorylation on PINK1-dependent sites is dysregulated in human heart failure, and cardiomyocyte-restricted Graf1 depletion in mice blunts mitochondrial clearance and attenuates compensatory metabolic adaptations to stress. Overall, we identify GRAF1 as an enzyme that coordinates cytoskeletal and metabolic remodeling to promote cardioprotection.
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Affiliation(s)
- Qiang Zhu
- Department of Pathology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Matthew E Combs
- Department of Pathology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Juan Liu
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Xue Bai
- Department of Pathology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Wenbo B Wang
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Laura E Herring
- UNC Proteomics Core Facility, Department of Pharmacology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jiandong Liu
- Department of Pathology, University of North Carolina, Chapel Hill, NC, 27599, USA
- McAllister Heart Institute University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Dawn E Bowles
- Division of Surgical Sciences, Duke University Medical Center, Durham, NC, 27710, USA
| | - Ryan T Gross
- Division of Surgical Sciences, Duke University Medical Center, Durham, NC, 27710, USA
| | - Michelle Mendiola Pla
- Division of Surgical Sciences, Duke University Medical Center, Durham, NC, 27710, USA
| | - Christopher P Mack
- Department of Pathology, University of North Carolina, Chapel Hill, NC, 27599, USA
- McAllister Heart Institute University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Joan M Taylor
- Department of Pathology, University of North Carolina, Chapel Hill, NC, 27599, USA.
- McAllister Heart Institute University of North Carolina, Chapel Hill, NC, 27599, USA.
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9
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Huang D, Chen S, Xiong D, Wang H, Zhu L, Wei Y, Li Y, Zou S. Mitochondrial Dynamics: Working with the Cytoskeleton and Intracellular Organelles to Mediate Mechanotransduction. Aging Dis 2023; 14:1511-1532. [PMID: 37196113 PMCID: PMC10529762 DOI: 10.14336/ad.2023.0201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/01/2023] [Indexed: 05/19/2023] Open
Abstract
Cells are constantly exposed to various mechanical environments; therefore, it is important that they are able to sense and adapt to changes. It is known that the cytoskeleton plays a critical role in mediating and generating extra- and intracellular forces and that mitochondrial dynamics are crucial for maintaining energy homeostasis. Nevertheless, the mechanisms by which cells integrate mechanosensing, mechanotransduction, and metabolic reprogramming remain poorly understood. In this review, we first discuss the interaction between mitochondrial dynamics and cytoskeletal components, followed by the annotation of membranous organelles intimately related to mitochondrial dynamic events. Finally, we discuss the evidence supporting the participation of mitochondria in mechanotransduction and corresponding alterations in cellular energy conditions. Notable advances in bioenergetics and biomechanics suggest that the mechanotransduction system composed of mitochondria, the cytoskeletal system, and membranous organelles is regulated through mitochondrial dynamics, which may be a promising target for further investigation and precision therapies.
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Affiliation(s)
| | | | | | | | | | | | - Yuyu Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Shujuan Zou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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10
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Read TA, Cisterna BA, Skruber K, Ahmadieh S, Lindamood HL, Vitriol JA, Shi Y, Lefebvre AE, Black JB, Butler MT, Bear JE, Cherezova A, Ilatovskaya DV, Weintraub NL, Vitriol EA. The actin binding protein profilin 1 is critical for mitochondria function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.07.552354. [PMID: 37609280 PMCID: PMC10441311 DOI: 10.1101/2023.08.07.552354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Profilin 1 (PFN1) is an actin binding protein that is vital for the polymerization of monomeric actin into filaments. Here we screened knockout cells for novel functions of PFN1 and discovered that mitophagy, a type of selective autophagy that removes defective or damaged mitochondria from the cell, was significantly upregulated in the absence of PFN1. Despite successful autophagosome formation and fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells still accumulate damaged, dysfunctional mitochondria. Subsequent imaging and functional assays showed that loss of PFN1 significantly affects mitochondria morphology, dynamics, and respiration. Further experiments revealed that PFN1 is located to the mitochondria matrix and is likely regulating mitochondria function from within rather than through polymerizing actin at the mitochondria surface. Finally, PFN1 mutants associated with amyotrophic lateral sclerosis (ALS) fail to rescue PFN1 knockout mitochondrial phenotypes and form aggregates within mitochondria, further perturbing them. Together, these results suggest a novel function for PFN1 in regulating mitochondria and identify a potential pathogenic mechanism of ALS-linked PFN1 variants.
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Affiliation(s)
- Tracy-Ann Read
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Bruno A. Cisterna
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kristen Skruber
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - Samah Ahmadieh
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Halli L. Lindamood
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Josefine A. Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Yang Shi
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Department of Population Health Sciences, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | | | - Joseph B. Black
- Division of Urologic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Mitchell T. Butler
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Alena Cherezova
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Daria V. Ilatovskaya
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Neil L. Weintraub
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Eric A. Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
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11
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Mageswaran SK, Grotjahn DA, Zeng X, Barad BA, Medina M, Hoang MH, Dobro MJ, Chang YW, Xu M, Yang WY, Jensen GJ. Nanoscale details of mitochondrial constriction revealed by cryoelectron tomography. Biophys J 2023; 122:3768-3782. [PMID: 37533259 PMCID: PMC10541493 DOI: 10.1016/j.bpj.2023.07.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/14/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023] Open
Abstract
Mitochondria adapt to changing cellular environments, stress stimuli, and metabolic demands through dramatic morphological remodeling of their shape, and thus function. Such mitochondrial dynamics is often dependent on cytoskeletal filament interactions. However, the precise organization of these filamentous assemblies remains speculative. Here, we apply cryogenic electron tomography to directly image the nanoscale architecture of the cytoskeletal-membrane interactions involved in mitochondrial dynamics in response to damage. We induced mitochondrial damage via membrane depolarization, a cellular stress associated with mitochondrial fragmentation and mitophagy. We find that, in response to acute membrane depolarization, mammalian mitochondria predominantly organize into tubular morphology that abundantly displays constrictions. We observe long bundles of both unbranched actin and septin filaments enriched at these constrictions. We also observed septin-microtubule interactions at these sites and elsewhere, suggesting that these two filaments guide each other in the cytosolic space. Together, our results provide empirical parameters for the architecture of mitochondrial constriction factors to validate/refine existing models and inform the development of new ones.
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Affiliation(s)
- Shrawan Kumar Mageswaran
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California; Department of Biophysics and Biochemistry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Danielle Ann Grotjahn
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California.
| | - Xiangrui Zeng
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Benjamin Asher Barad
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California
| | - Michaela Medina
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California
| | - My Hanh Hoang
- Department of Biophysics and Biochemistry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Yi-Wei Chang
- Department of Biophysics and Biochemistry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Min Xu
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Wei Yuan Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California; Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah.
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12
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Fung TS, Chakrabarti R, Higgs HN. The multiple links between actin and mitochondria. Nat Rev Mol Cell Biol 2023; 24:651-667. [PMID: 37277471 PMCID: PMC10528321 DOI: 10.1038/s41580-023-00613-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2023] [Indexed: 06/07/2023]
Abstract
Actin plays many well-known roles in cells, and understanding any specific role is often confounded by the overlap of multiple actin-based structures in space and time. Here, we review our rapidly expanding understanding of actin in mitochondrial biology, where actin plays multiple distinct roles, exemplifying the versatility of actin and its functions in cell biology. One well-studied role of actin in mitochondrial biology is its role in mitochondrial fission, where actin polymerization from the endoplasmic reticulum through the formin INF2 has been shown to stimulate two distinct steps. However, roles for actin during other types of mitochondrial fission, dependent on the Arp2/3 complex, have also been described. In addition, actin performs functions independent of mitochondrial fission. During mitochondrial dysfunction, two distinct phases of Arp2/3 complex-mediated actin polymerization can be triggered. First, within 5 min of dysfunction, rapid actin assembly around mitochondria serves to suppress mitochondrial shape changes and to stimulate glycolysis. At a later time point, at more than 1 h post-dysfunction, a second round of actin polymerization prepares mitochondria for mitophagy. Finally, actin can both stimulate and inhibit mitochondrial motility depending on the context. These motility effects can either be through the polymerization of actin itself or through myosin-based processes, with myosin 19 being an important mitochondrially attached myosin. Overall, distinct actin structures assemble in response to diverse stimuli to affect specific changes to mitochondria.
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Affiliation(s)
- Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
- MitoCare Center, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.
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13
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Shimura D, Shaw RM. Live-cell imaging and analysis of actin-mediated mitochondrial fission. STAR Protoc 2023; 4:101958. [PMID: 36542522 PMCID: PMC9795527 DOI: 10.1016/j.xpro.2022.101958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/02/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Current approaches, such as fixed-cell imaging or single-snapshot imaging, are insufficient to capture cytoskeleton-mediated mitochondrial fission. Here, we present a protocol to capture actin-mediated mitochondrial fission using high-resolution time-lapse imaging. We describe steps starting from cell preparation and mitochondria labeling through to live-cell imaging and final analysis. This approach is also applicable for analysis of multiple cytoskeleton-mediated organelle events such as vesicle trafficking, membrane fusion, and endocytic events in live cells. For complete details on the use and execution of this protocol, please refer to Shimura et al. (2021).1.
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Affiliation(s)
- Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Surgery, School of Medicine, University of Utah, Salt Lake City, UT 84112, USA.
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA.
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14
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Quintana-Cabrera R, Scorrano L. Determinants and outcomes of mitochondrial dynamics. Mol Cell 2023; 83:857-876. [PMID: 36889315 DOI: 10.1016/j.molcel.2023.02.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/13/2023] [Accepted: 02/13/2023] [Indexed: 03/09/2023]
Abstract
Mitochondria are not only central organelles in metabolism and energy conversion but are also platforms for cellular signaling cascades. Classically, the shape and ultrastructure of mitochondria were depicted as static. The discovery of morphological transitions during cell death and of conserved genes controlling mitochondrial fusion and fission contributed to establishing the concept that mitochondrial morphology and ultrastructure are dynamically regulated by mitochondria-shaping proteins. These finely tuned, dynamic changes in mitochondrial shape can in turn control mitochondrial function, and their alterations in human diseases suggest that this space can be explored for drug discovery. Here, we review the basic tenets and molecular mechanisms of mitochondrial morphology and ultrastructure, describing how they can coordinately define mitochondrial function.
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Affiliation(s)
| | - Luca Scorrano
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; Department of Biology, University of Padova, Via U. Bassi 58B, 35121 Padova, Italy.
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15
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Campellone KG, Lebek NM, King VL. Branching out in different directions: Emerging cellular functions for the Arp2/3 complex and WASP-family actin nucleation factors. Eur J Cell Biol 2023; 102:151301. [PMID: 36907023 DOI: 10.1016/j.ejcb.2023.151301] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 02/07/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
The actin cytoskeleton impacts practically every function of a eukaryotic cell. Historically, the best-characterized cytoskeletal activities are in cell morphogenesis, motility, and division. The structural and dynamic properties of the actin cytoskeleton are also crucial for establishing, maintaining, and changing the organization of membrane-bound organelles and other intracellular structures. Such activities are important in nearly all animal cells and tissues, although distinct anatomical regions and physiological systems rely on different regulatory factors. Recent work indicates that the Arp2/3 complex, a broadly expressed actin nucleator, drives actin assembly during several intracellular stress response pathways. These newly described Arp2/3-mediated cytoskeletal rearrangements are coordinated by members of the Wiskott-Aldrich Syndrome Protein (WASP) family of actin nucleation-promoting factors. Thus, the Arp2/3 complex and WASP-family proteins are emerging as crucial players in cytoplasmic and nuclear activities including autophagy, apoptosis, chromatin dynamics, and DNA repair. Characterizations of the functions of the actin assembly machinery in such stress response mechanisms are advancing our understanding of both normal and pathogenic processes, and hold great promise for providing insights into organismal development and interventions for disease.
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Affiliation(s)
- Kenneth G Campellone
- Department of Molecular and Cell Biology, Institute for Systems Genomics; University of Connecticut; Storrs, CT, USA.
| | - Nadine M Lebek
- Department of Molecular and Cell Biology, Institute for Systems Genomics; University of Connecticut; Storrs, CT, USA
| | - Virginia L King
- Department of Molecular and Cell Biology, Institute for Systems Genomics; University of Connecticut; Storrs, CT, USA
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16
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O'Sullivan JDB, Bullen A, Mann ZF. Mitochondrial form and function in hair cells. Hear Res 2023; 428:108660. [PMID: 36525891 DOI: 10.1016/j.heares.2022.108660] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/07/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
Hair cells (HCs) are specialised sensory receptors residing in the neurosensory epithelia of inner ear sense organs. The precise morphological and physiological properties of HCs allow us to perceive sound and interact with the world around us. Mitochondria play a significant role in normal HC function and are also intricately involved in HC death. They generate ATP essential for sustaining the activity of ion pumps, Ca2+ transporters and the integrity of the stereociliary bundle during transduction as well as regulating cytosolic calcium homoeostasis during synaptic transmission. Advances in imaging techniques have allowed us to study mitochondrial populations throughout the HC, and how they interact with other organelles. These analyses have identified distinct mitochondrial populations between the apical and basolateral portions of the HC, in which mitochondrial morphology appears determined by the physiological processes in the different cellular compartments. Studies in HCs across species show that ototoxic agents, ageing and noise damage directly impact mitochondrial structure and function resulting in HC death. Deciphering the molecular mechanisms underlying this mitochondrial sensitivity, and how their morphology relates to their function during HC death, requires that we first understand this relationship in the context of normal HC function.
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Affiliation(s)
- James D B O'Sullivan
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral, Craniofacial Sciences, King's College London, London SE1 9RT, U.K
| | - Anwen Bullen
- UCL Ear Institute, University College London, London WC1×8EE, U.K.
| | - Zoë F Mann
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral, Craniofacial Sciences, King's College London, London SE1 9RT, U.K.
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17
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Chakrabarti R, Fung TS, Kang T, Elonkirjo PW, Suomalainen A, Usherwood EJ, Higgs HN. Mitochondrial dysfunction triggers actin polymerization necessary for rapid glycolytic activation. J Cell Biol 2022; 221:e202201160. [PMID: 36102863 PMCID: PMC9477750 DOI: 10.1083/jcb.202201160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/02/2022] [Accepted: 08/25/2022] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial damage represents a dramatic change in cellular homeostasis. One rapid response is perimitochondrial actin polymerization, termed acute damage-induced actin (ADA). The consequences of ADA are not understood. In this study, we show evidence suggesting that ADA is linked to rapid glycolytic activation upon mitochondrial damage in multiple cells, including mouse embryonic fibroblasts and effector CD8+ T lymphocytes. ADA-inducing treatments include CCCP, antimycin, rotenone, oligomycin, and hypoxia. The Arp2/3 complex inhibitor CK666 or the mitochondrial sodium-calcium exchanger (NCLX) inhibitor CGP37157 inhibits both ADA and the glycolytic increase within 5 min, supporting ADA's role in glycolytic stimulation. Two situations causing chronic reductions in mitochondrial ATP production, mitochondrial DNA depletion and mutation to the NDUFS4 subunit of complex 1 of the electron transport chain, cause persistent perimitochondrial actin filaments similar to ADA. CK666 treatment causes rapid mitochondrial actin loss and a drop in ATP in NDUFS4 knock-out cells. We propose that ADA is necessary for rapid glycolytic activation upon mitochondrial impairment, to re-establish ATP production.
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Affiliation(s)
- Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Taewook Kang
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Pieti W. Elonkirjo
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anu Suomalainen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Edward J. Usherwood
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Henry N. Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
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18
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Kage F, Vicente-Manzanares M, McEwan BC, Kettenbach AN, Higgs HN. Myosin II proteins are required for organization of calcium-induced actin networks upstream of mitochondrial division. Mol Biol Cell 2022; 33:ar63. [PMID: 35427150 PMCID: PMC9561854 DOI: 10.1091/mbc.e22-01-0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The formin INF2 polymerizes a calcium-activated cytoplasmic network of actin filaments, which we refer to as calcium-induced actin polymerization (CIA). CIA plays important roles in multiple cellular processes, including mitochondrial dynamics and vesicle transport. Here, we show that nonmuscle myosin II (NMII) is activated within 60 s of calcium stimulation and rapidly recruited to the CIA network. Knockout of any individual NMII in U2OS cells affects the organization of the CIA network, as well as three downstream effects: endoplasmic-reticulum-to-mitochondrial calcium transfer, mitochondrial Drp1 recruitment, and mitochondrial division. Interestingly, while NMIIC is the least abundant NMII in U2OS cells (>200-fold less than NMIIA and >10-fold less than NMIIB), its knockout is equally deleterious to CIA. On the basis of these results, we propose that myosin II filaments containing all three NMII heavy chains exert organizational and contractile roles in the CIA network. In addition, NMIIA knockout causes a significant decrease in myosin regulatory light chain levels, which might have additional effects.
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Affiliation(s)
- Frieda Kage
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Miguel Vicente-Manzanares
- Centro de Investigacion del Cancer/Instituto de Biologia Molecular y Celular del Cancer, Centro Mixto Universidad de Salamanca, 37007 Salamanca, Spain
| | - Brennan C. McEwan
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Arminja N. Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Henry N. Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
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19
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Fung TS, Chakrabarti R, Kollasser J, Rottner K, Stradal TEB, Kage F, Higgs HN. Parallel kinase pathways stimulate actin polymerization at depolarized mitochondria. Curr Biol 2022; 32:1577-1592.e8. [PMID: 35290799 PMCID: PMC9078333 DOI: 10.1016/j.cub.2022.02.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/04/2022] [Accepted: 02/21/2022] [Indexed: 12/31/2022]
Abstract
Mitochondrial damage (MtD) represents a dramatic change in cellular homeostasis, necessitating metabolic changes and stimulating mitophagy. One rapid response to MtD is a rapid peri-mitochondrial actin polymerization termed ADA (acute damage-induced actin). The activation mechanism for ADA is unknown. Here, we use mitochondrial depolarization or the complex I inhibitor metformin to induce ADA. We show that two parallel signaling pathways are required for ADA. In one pathway, increased cytosolic calcium in turn activates PKC-β, Rac, WAVE regulatory complex, and Arp2/3 complex. In the other pathway, a drop in cellular ATP in turn activates AMPK (through LKB1), Cdc42, and FMNL formins. We also identify putative guanine nucleotide exchange factors for Rac and Cdc42, Trio and Fgd1, respectively, whose phosphorylation states increase upon mitochondrial depolarization and whose suppression inhibits ADA. The depolarization-induced calcium increase is dependent on the mitochondrial sodium-calcium exchanger NCLX, suggesting initial mitochondrial calcium efflux. We also show that ADA inhibition results in enhanced mitochondrial shape changes upon mitochondrial depolarization, suggesting that ADA inhibits these shape changes. These depolarization-induced shape changes are not fragmentation but a circularization of the inner mitochondrial membrane, which is dependent on the inner mitochondrial membrane protease Oma1. ADA inhibition increases the proteolytic processing of an Oma1 substrate, the dynamin GTPase Opa1. These results show that ADA requires the combined action of the Arp2/3 complex and formin proteins to polymerize a network of actin filaments around mitochondria and that the ADA network inhibits the rapid mitochondrial shape changes that occur upon mitochondrial depolarization.
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Affiliation(s)
- Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Jana Kollasser
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Klemens Rottner
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany; Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany
| | - Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Frieda Kage
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA.
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20
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Fernández Casafuz AB, De Rossi MC, Bruno L. Morphological fluctuations of individual mitochondria in living cells. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 34:094005. [PMID: 34847540 DOI: 10.1088/1361-648x/ac3e9c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/30/2021] [Indexed: 06/13/2023]
Abstract
Uncovering the link between mitochondrial morphology, dynamics, positioning and function is challenging. Mitochondria are very flexible organelles that are subject to tension and compression within cells. Recent findings highlighted the importance of these mechanical aspects in the regulation of mitochondria dynamics, arising the question on which are the processes and mechanisms involved in their shape remodeling. In this work we explored in detail the morphological changes and spatio-temporal fluctuations of these organelles in livingXenopus laevismelanophores, a well-characterized cellular model. We developed an automatic method for the classification of mitochondria shapes based on the analysis of the curvature of the contour shape from confocal microscopy images. A persistence length of 2.1μm was measured, quantifying, for the first time, the bending plasticity of mitochondria in their cellular environment. The shape evolution at the single organelle level was followed during a few minutes revealing that mitochondria can bend and unbend in the seconds timescale. Furthermore, the inspection of confocal movies simultaneously registering fluorescent mitochondria and microtubules suggests that the cytoskeleton network architecture and dynamics play a significant role in mitochondria shape remodeling and fluctuations. For instance changes from sinuous to elongated organelles related to transitions from confined behavior to fast directed motion along microtubule tracks were observed.
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Affiliation(s)
- Agustina B Fernández Casafuz
- CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Instituto de Cálculo, Buenos Aires, Argentina
| | - María Cecilia De Rossi
- CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina
| | - Luciana Bruno
- CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Instituto de Cálculo, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina
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21
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Galvan DL, Mise K, Danesh FR. Mitochondrial Regulation of Diabetic Kidney Disease. Front Med (Lausanne) 2021; 8:745279. [PMID: 34646847 PMCID: PMC8502854 DOI: 10.3389/fmed.2021.745279] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 08/30/2021] [Indexed: 12/14/2022] Open
Abstract
The role and nature of mitochondrial dysfunction in diabetic kidney disease (DKD) has been extensively studied. Yet, the molecular drivers of mitochondrial remodeling in DKD are poorly understood. Diabetic kidney cells exhibit a cascade of mitochondrial dysfunction ranging from changes in mitochondrial morphology to significant alterations in mitochondrial biogenesis, biosynthetic, bioenergetics and production of reactive oxygen species (ROS). How these changes individually or in aggregate contribute to progression of DKD remain to be fully elucidated. Nevertheless, because of the remarkable progress in our basic understanding of the role of mitochondrial biology and its dysfunction in DKD, there is great excitement on future targeted therapies based on improving mitochondrial function in DKD. This review will highlight the latest advances in understanding the nature of mitochondria dysfunction and its role in progression of DKD, and the development of mitochondrial targets that could be potentially used to prevent its progression.
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Affiliation(s)
- Daniel L Galvan
- Section of Nephrology, The University of Texas at MD Anderson Cancer Center, Houston, TX, United States
| | - Koki Mise
- Section of Nephrology, The University of Texas at MD Anderson Cancer Center, Houston, TX, United States.,Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Farhad R Danesh
- Section of Nephrology, The University of Texas at MD Anderson Cancer Center, Houston, TX, United States.,Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, United States
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22
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Bamburg JR, Minamide LS, Wiggan O, Tahtamouni LH, Kuhn TB. Cofilin and Actin Dynamics: Multiple Modes of Regulation and Their Impacts in Neuronal Development and Degeneration. Cells 2021; 10:cells10102726. [PMID: 34685706 PMCID: PMC8534876 DOI: 10.3390/cells10102726] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 02/06/2023] Open
Abstract
Proteins of the actin depolymerizing factor (ADF)/cofilin family are ubiquitous among eukaryotes and are essential regulators of actin dynamics and function. Mammalian neurons express cofilin-1 as the major isoform, but ADF and cofilin-2 are also expressed. All isoforms bind preferentially and cooperatively along ADP-subunits in F-actin, affecting the filament helical rotation, and when either alone or when enhanced by other proteins, promotes filament severing and subunit turnover. Although self-regulating cofilin-mediated actin dynamics can drive motility without post-translational regulation, cells utilize many mechanisms to locally control cofilin, including cooperation/competition with other proteins. Newly identified post-translational modifications function with or are independent from the well-established phosphorylation of serine 3 and provide unexplored avenues for isoform specific regulation. Cofilin modulates actin transport and function in the nucleus as well as actin organization associated with mitochondrial fission and mitophagy. Under neuronal stress conditions, cofilin-saturated F-actin fragments can undergo oxidative cross-linking and bundle together to form cofilin-actin rods. Rods form in abundance within neurons around brain ischemic lesions and can be rapidly induced in neurites of most hippocampal and cortical neurons through energy depletion or glutamate-induced excitotoxicity. In ~20% of rodent hippocampal neurons, rods form more slowly in a receptor-mediated process triggered by factors intimately connected to disease-related dementias, e.g., amyloid-β in Alzheimer’s disease. This rod-inducing pathway requires a cellular prion protein, NADPH oxidase, and G-protein coupled receptors, e.g., CXCR4 and CCR5. Here, we will review many aspects of cofilin regulation and its contribution to synaptic loss and pathology of neurodegenerative diseases.
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Affiliation(s)
- James R. Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Correspondence: ; Tel.: +1-970-988-9120; Fax: +1-970-491-0494
| | - Laurie S. Minamide
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
| | - O’Neil Wiggan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
| | - Lubna H. Tahtamouni
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Department of Biology and Biotechnology, The Hashemite University, Zarqa 13115, Jordan
| | - Thomas B. Kuhn
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, AK 99775, USA
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23
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Local complement factor H protects kidney endothelial cell structure and function. Kidney Int 2021; 100:824-836. [PMID: 34139209 DOI: 10.1016/j.kint.2021.05.033] [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: 05/20/2020] [Revised: 05/09/2021] [Accepted: 05/20/2021] [Indexed: 12/25/2022]
Abstract
Factor H (FH) is a critical regulator of the alternative complement pathway and its deficiency or mutation underlie kidney diseases such as dense deposit disease. Since vascular dysfunction is an important facet of kidney disease, maintaining optimal function of the lining endothelial cells is important for vascular health. To investigate the molecular mechanisms that are regulated by FH in endothelial cells, FH deficient and sufficient mouse kidney endothelial cell cultures were established. Endothelial FH deficiency resulted in cytoskeletal remodeling, increased angiogenic potential, loss of cellular layer integrity and increased cell proliferation. FH reconstitution prevented these FH-dependent proliferative changes. Respiratory flux analysis showed reduced basal mitochondrial respiration, ATP production and maximal respiratory capacity in FH deficient endothelial cells, while proton leak remained unaltered. Similar changes were observed in FH deficient human glomerular endothelial cells indicating the translational potential of these studies. Gene expression analysis revealed that the FH-dependent gene changes in mouse kidney endothelial cells include significant upregulation of genes involved in inflammation and the complement system. The transcription factor nuclear factor-kB, that regulates many biological processes, was translocated from the cytoplasm to the nucleus in the absence of FH. Thus, our studies show the functional relevance of intrinsic FH in kidney endothelial cells in man and mouse.
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24
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Sun X, Alford J, Qiu H. Structural and Functional Remodeling of Mitochondria in Cardiac Diseases. Int J Mol Sci 2021; 22:ijms22084167. [PMID: 33920673 PMCID: PMC8072869 DOI: 10.3390/ijms22084167] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/14/2021] [Accepted: 04/15/2021] [Indexed: 12/31/2022] Open
Abstract
Mitochondria undergo structural and functional remodeling to meet the cell demand in response to the intracellular and extracellular stimulations, playing an essential role in maintaining normal cellular function. Merging evidence demonstrated that dysregulation of mitochondrial remodeling is a fundamental driving force of complex human diseases, highlighting its crucial pathophysiological roles and therapeutic potential. In this review, we outlined the progress of the molecular basis of mitochondrial structural and functional remodeling and their regulatory network. In particular, we summarized the latest evidence of the fundamental association of impaired mitochondrial remodeling in developing diverse cardiac diseases and the underlying mechanisms. We also explored the therapeutic potential related to mitochondrial remodeling and future research direction. This updated information would improve our knowledge of mitochondrial biology and cardiac diseases’ pathogenesis, which would inspire new potential strategies for treating these diseases by targeting mitochondria remodeling.
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Affiliation(s)
| | | | - Hongyu Qiu
- Correspondence: ; Tel.: +404-413-3371; Fax: +404-413-9566
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25
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Abstract
Mitochondria are multifunctional organelles that not only produce energy for the cell, but are also important for cell signalling, apoptosis and many biosynthetic pathways. In most cell types, they form highly dynamic networks that are constantly remodelled through fission and fusion events, repositioned by motor-dependent transport and degraded when they become dysfunctional. Motor proteins and their tracks are key regulators of mitochondrial homeostasis, and in this Review, we discuss the diverse functions of the three classes of motor proteins associated with mitochondria - the actin-based myosins, as well as the microtubule-based kinesins and dynein. In addition, Miro and TRAK proteins act as adaptors that link kinesin-1 and dynein, as well as myosin of class XIX (MYO19), to mitochondria and coordinate microtubule- and actin-based motor activities. Here, we highlight the roles of motor proteins and motor-linked track dynamics in the transporting and docking of mitochondria, and emphasize their adaptations in specialized cells. Finally, we discuss how motor-cargo complexes mediate changes in mitochondrial morphology through fission and fusion, and how they modulate the turnover of damaged organelles via quality control pathways, such as mitophagy. Understanding the importance of motor proteins for mitochondrial homeostasis will help to elucidate the molecular basis of a number of human diseases.
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Affiliation(s)
- Antonina J Kruppa
- Cambridge Institute for Medical Research, Department of Clinical Biochemistry, University of Cambridge, Cambridge Biomedical Campus, The Keith Peters Building, Hills Road, Cambridge CB2 0XY, UK
| | - Folma Buss
- Cambridge Institute for Medical Research, Department of Clinical Biochemistry, University of Cambridge, Cambridge Biomedical Campus, The Keith Peters Building, Hills Road, Cambridge CB2 0XY, UK
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26
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Fenton AR, Jongens TA, Holzbaur ELF. Mitochondrial dynamics: Shaping and remodeling an organelle network. Curr Opin Cell Biol 2021; 68:28-36. [PMID: 32961383 PMCID: PMC7925334 DOI: 10.1016/j.ceb.2020.08.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 01/07/2023]
Abstract
Mitochondria form networks that continually remodel and adapt to carry out their cellular function. The mitochondrial network is remodeled through changes in mitochondrial morphology, number, and distribution within the cell. Mitochondrial dynamics depend directly on fission, fusion, shape transition, and transport or tethering along the cytoskeleton. Over the past several years, many of the mechanisms underlying these processes have been uncovered. It has become clear that each process is precisely and contextually regulated within the cell. Here, we discuss the mechanisms regulating each aspect of mitochondrial dynamics, which together shape the network as a whole.
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Affiliation(s)
- Adam R Fenton
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA; Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Thomas A Jongens
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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27
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A M, Latario CJ, Pickrell LE, Higgs HN. Lysine acetylation of cytoskeletal proteins: Emergence of an actin code. J Biophys Biochem Cytol 2020; 219:211455. [PMID: 33044556 PMCID: PMC7555357 DOI: 10.1083/jcb.202006151] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/26/2020] [Accepted: 09/02/2020] [Indexed: 02/06/2023] Open
Abstract
Reversible lysine acetylation of nuclear proteins such as histones is a long-established important regulatory mechanism for chromatin remodeling and transcription. In the cytoplasm, acetylation of a number of cytoskeletal proteins, including tubulin, cortactin, and the formin mDia2, regulates both cytoskeletal assembly and stability. More recently, acetylation of actin itself was revealed to regulate cytoplasmic actin polymerization through the formin INF2, with downstream effects on ER-to-mitochondrial calcium transfer, mitochondrial fission, and vesicle transport. This finding raises the possibility that actin acetylation, along with other post-translational modifications to actin, might constitute an "actin code," similar to the "histone code" or "tubulin code," controlling functional shifts to these central cellular proteins. Given the multiple roles of actin in nuclear functions, its modifications might also have important roles in gene expression.
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28
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Ipponjima S, Umino Y, Nagayama M, Denda M. Live imaging of alterations in cellular morphology and organelles during cornification using an epidermal equivalent model. Sci Rep 2020; 10:5515. [PMID: 32218450 PMCID: PMC7099034 DOI: 10.1038/s41598-020-62240-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/09/2020] [Indexed: 11/30/2022] Open
Abstract
The stratum corneum plays a crucial role in epidermal barrier function. Various changes occur in granular cells at the uppermost stratum granulosum during cornification. To understand the temporal details of this process, we visualized the cell shape and organelles of cornifying keratinocytes in a living human epidermal equivalent model. Three-dimensional time-lapse imaging with a two-photon microscope revealed that the granular cells did not simply flatten but first temporarily expanded in thickness just before flattening during cornification. Moreover, before expansion, intracellular vesicles abruptly stopped moving, and mitochondria were depolarized. When mitochondrial morphology and quantity were assessed, granular cells with fewer, mostly punctate mitochondria tended to transition to corneocytes. Several minutes after flattening, DNA leakage from the nucleus was visualized. We also observed extension of the cell-flattening time induced by the suppression of filaggrin expression. Overall, we successfully visualized the time-course of cornification, which describes temporal relationships between alterations in the transition from granular cells to corneocytes.
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Affiliation(s)
- Sari Ipponjima
- Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan.
| | - Yuki Umino
- Shiseido Global Innovation Center, Yokohama, Japan
| | - Masaharu Nagayama
- Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
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29
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De Martino S, Zhang W, Klausen L, Lou HY, Li X, Alfonso FS, Cavalli S, Netti PA, Santoro F, Cui B. Dynamic Manipulation of Cell Membrane Curvature by Light-Driven Reshaping of Azopolymer. NANO LETTERS 2020; 20:577-584. [PMID: 31846332 PMCID: PMC7207080 DOI: 10.1021/acs.nanolett.9b04307] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Local curvatures on the cell membrane serve as signaling hubs that promote curvature-dependent protein interactions and modulate a variety of cellular processes including endocytosis, exocytosis, and the actin cytoskeleton. However, precisely controlling the location and the degree of membrane curvature in live cells has not been possible until recently, where studies show that nanofabricated vertical structures on a substrate can imprint their shapes on the cell membrane to induce well-defined curvatures in adherent cells. Nevertheless, the intrinsic static nature of these engineered nanostructures prevents dynamic modulation of membrane curvatures. In this work, we engineer light-responsive polymer structures whose shape can be dynamically modulated by light and thus change the induced-membrane curvatures on-demand. Specifically, we fabricate three-dimensional azobenzene-based polymer structures that change from a vertical pillar to an elongated vertical bar shape upon green light illumination. We observe that U2OS cells cultured on azopolymer nanostructures rapidly respond to the topographical change of the substrate underneath. The dynamically induced high membrane curvatures at bar ends promote local accumulation of actin fibers and actin nucleator Arp2/3 complex. The ability to dynamically manipulate the membrane curvature and analyze protein response in real-time provides a new way to study curvature-dependent processes in live cells.
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Affiliation(s)
- Selene De Martino
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci, 53, 80125 Napoli, Italy
- Dipartimento di Ingegneria Chimica dei Materiali e della Produzione Industriale, DICMAPI, Università degli Studi di Napoli Federico II, Piazzale Tecchio, 80, 80125 Napoli, Italy
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, United States
| | - Wei Zhang
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, United States
| | - Lasse Klausen
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, United States
| | - Hsin-Ya Lou
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, United States
| | - Xiao Li
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, United States
| | - Felix S. Alfonso
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, United States
| | - Silvia Cavalli
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci, 53, 80125 Napoli, Italy
| | - Paolo A. Netti
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci, 53, 80125 Napoli, Italy
- Dipartimento di Ingegneria Chimica dei Materiali e della Produzione Industriale, DICMAPI, Università degli Studi di Napoli Federico II, Piazzale Tecchio, 80, 80125 Napoli, Italy
| | - Francesca Santoro
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci, 53, 80125 Napoli, Italy
- Corresponding Authors:.
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, United States
- Corresponding Authors:.
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30
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Regulation of INF2-mediated actin polymerization through site-specific lysine acetylation of actin itself. Proc Natl Acad Sci U S A 2019; 117:439-447. [PMID: 31871199 DOI: 10.1073/pnas.1914072117] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
INF2 is a formin protein that accelerates actin polymerization. A common mechanism for formin regulation is autoinhibition, through interaction between the N-terminal diaphanous inhibitory domain (DID) and C-terminal diaphanous autoregulatory domain (DAD). We recently showed that INF2 uses a variant of this mechanism that we term "facilitated autoinhibition," whereby a complex consisting of cyclase-associated protein (CAP) bound to lysine-acetylated actin (KAc-actin) is required for INF2 inhibition, in a manner requiring INF2-DID. Deacetylation of actin in the CAP/KAc-actin complex activates INF2. Here we use lysine-to-glutamine mutations as acetylmimetics to map the relevant lysines on actin for INF2 regulation, focusing on K50, K61, and K328. Biochemically, K50Q- and K61Q-actin, when bound to CAP2, inhibit full-length INF2 but not INF2 lacking DID. When not bound to CAP, these mutant actins polymerize similarly to WT-actin in the presence or absence of INF2, suggesting that the effect of the mutation is directly on INF2 regulation. In U2OS cells, K50Q- and K61Q-actin inhibit INF2-mediated actin polymerization when expressed at low levels. Direct-binding studies show that the CAP WH2 domain binds INF2-DID with submicromolar affinity but has weak affinity for actin monomers, while INF2-DAD binds CAP/K50Q-actin 5-fold better than CAP/WT-actin. Actin in complex with full-length CAP2 is predominately ATP-bound. These interactions suggest an inhibition model whereby CAP/KAc-actin serves as a bridge between INF2 DID and DAD. In U2OS cells, INF2 is 90-fold and 5-fold less abundant than CAP1 and CAP2, respectively, suggesting that there is sufficient CAP for full INF2 inhibition.
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31
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First person – Tak Shun Fung. J Cell Sci 2019. [DOI: 10.1242/jcs.238477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Tak Shun Fung is first author on ‘Two distinct actin filament populations have effects on mitochondria, with differences in stimuli and assembly factors’, published in JCS. Tak Shun is a graduate student in the lab of Prof. Henry Higgs at Geisel School of Medicine at Dartmouth, USA, investigating the relationship between actin cytoskeletal dynamics and mitochondrial dynamics.
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