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Yang Y, Jia X, Yang X, Wang J, Fang Y, Ying X, Zhang M, Wei J, Pan Y. Targeting VDAC: A potential therapeutic approach for mitochondrial dysfunction in Alzheimer's disease. Brain Res 2024; 1835:148920. [PMID: 38599511 DOI: 10.1016/j.brainres.2024.148920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/05/2024] [Indexed: 04/12/2024]
Abstract
Mitochondrial dysfunction has been implicated in the pathogenesis of Alzheimer's disease, a neurodegenerative disorder characterized by progressive cognitive decline. Voltage-dependent anion channel (VDAC), a protein located in the outer mitochondrial membrane, plays a critical role in regulating mitochondrial function and cellular energy metabolism. Recent studies have identified VDAC as a potential therapeutic target for Alzheimer's disease. This article aims to provide an overview of the role of VDAC in mitochondrial dysfunction, its association with Alzheimer's disease, and the potential of targeting VDAC for developing novel therapeutic interventions. Understanding the involvement of VDAC in Alzheimer's disease may pave the way for the development of effective treatments that can restore mitochondrial function and halt disease progression.
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Affiliation(s)
- Yaqian Yang
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
| | - Xiaotao Jia
- Department of Neurology, The Affifiliated Xi'an Central Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710003, China
| | - Xinmao Yang
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
| | - Jie Wang
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
| | - Yan Fang
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
| | - Xiaoping Ying
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
| | - Meiqian Zhang
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
| | - Jing Wei
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
| | - Yanfang Pan
- Department of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China.
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2
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Yuan Z, van Delft MF, Li MX, Sumardy F, Smith BJ, Huang DCS, Lessene G, Khakam Y, Jin R, He S, Smith NA, Birkinshaw RW, Czabotar PE, Dewson G. Key residues in the VDAC2-BAK complex can be targeted to modulate apoptosis. PLoS Biol 2024; 22:e3002617. [PMID: 38696533 PMCID: PMC11098506 DOI: 10.1371/journal.pbio.3002617] [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: 12/23/2023] [Revised: 05/16/2024] [Accepted: 04/05/2024] [Indexed: 05/04/2024] Open
Abstract
BAK and BAX execute intrinsic apoptosis by permeabilising the mitochondrial outer membrane. Their activity is regulated through interactions with pro-survival BCL-2 family proteins and with non-BCL-2 proteins including the mitochondrial channel protein VDAC2. VDAC2 is important for bringing both BAK and BAX to mitochondria where they execute their apoptotic function. Despite this important function in apoptosis, while interactions with pro-survival family members are well characterised and have culminated in the development of drugs that target these interfaces to induce cancer cell apoptosis, the interaction between BAK and VDAC2 remains largely undefined. Deep scanning mutagenesis coupled with cysteine linkage identified key residues in the interaction between BAK and VDAC2. Obstructive labelling of specific residues in the BH3 domain or hydrophobic groove of BAK disrupted this interaction. Conversely, mutating specific residues in a cytosol-exposed region of VDAC2 stabilised the interaction with BAK and inhibited BAK apoptotic activity. Thus, this VDAC2-BAK interaction site can potentially be targeted to either inhibit BAK-mediated apoptosis in scenarios where excessive apoptosis contributes to disease or to promote BAK-mediated apoptosis for cancer therapy.
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Affiliation(s)
- Zheng Yuan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Mark F. van Delft
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Mark Xiang Li
- Peter MacCallum Cancer Centre, Parkville, Melbourne, Australia
| | - Fransisca Sumardy
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
| | - Brian J. Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - David C. S. Huang
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Guillaume Lessene
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, Melbourne, Australia
| | - Yelena Khakam
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
| | - Ruitao Jin
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
- Research School of Biology, Australian National University, Canberra, Australia
| | - Sitong He
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Nicholas A. Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Richard W. Birkinshaw
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Peter E. Czabotar
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Grant Dewson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
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3
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Magrì A, Lipari CLR, Caccamo A, Battiato G, Conti Nibali S, De Pinto V, Guarino F, Messina A. AAV-mediated upregulation of VDAC1 rescues the mitochondrial respiration and sirtuins expression in a SOD1 mouse model of inherited ALS. Cell Death Discov 2024; 10:178. [PMID: 38627359 PMCID: PMC11021507 DOI: 10.1038/s41420-024-01949-w] [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: 11/17/2023] [Revised: 03/29/2024] [Accepted: 04/08/2024] [Indexed: 04/19/2024] Open
Abstract
Mitochondrial dysfunction represents one of the most common molecular hallmarks of both sporadic and familial forms of amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder caused by the selective degeneration and death of motor neurons. The accumulation of misfolded proteins on and within mitochondria, as observed for SOD1 G93A mutant, correlates with a drastic reduction of mitochondrial respiration and the inhibition of metabolites exchanges, including ADP/ATP and NAD+/NADH, across the Voltage-Dependent Anion-selective Channel 1 (VDAC1), the most abundant channel protein of the outer mitochondrial membrane. Here, we show that the AAV-mediated upregulation of VDAC1 in the spinal cord of transgenic mice expressing SOD1 G93A completely rescues the mitochondrial respiratory profile. This correlates with the increased activity and levels of key regulators of mitochondrial functions and maintenance, namely the respiratory chain Complex I and the sirtuins (Sirt), especially Sirt3. Furthermore, the selective increase of these mitochondrial proteins is associated with an increase in Tom20 levels, the receptor subunit of the TOM complex. Overall, our results indicate that the overexpression of VDAC1 has beneficial effects on ALS-affected tissue by stabilizing the Complex I-Sirt3 axis.
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Affiliation(s)
- Andrea Magrì
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via S. Sofia 97, 95123, Catania, Italy
- we.MitoBiotech s.r.l., C.so Italia 172, 95125, Catania, Italy
| | - Cristiana Lucia Rita Lipari
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123, Catania, Italy
| | - Antonella Caccamo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le F. Stagno d'Alcontres 32, 98166, Messina, Italy
| | - Giuseppe Battiato
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123, Catania, Italy
| | - Stefano Conti Nibali
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123, Catania, Italy
| | - Vito De Pinto
- we.MitoBiotech s.r.l., C.so Italia 172, 95125, Catania, Italy
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123, Catania, Italy
| | - Francesca Guarino
- we.MitoBiotech s.r.l., C.so Italia 172, 95125, Catania, Italy
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123, Catania, Italy
| | - Angela Messina
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via S. Sofia 97, 95123, Catania, Italy.
- we.MitoBiotech s.r.l., C.so Italia 172, 95125, Catania, Italy.
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4
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Bartman S, Coppotelli G, Ross JM. Mitochondrial Dysfunction: A Key Player in Brain Aging and Diseases. Curr Issues Mol Biol 2024; 46:1987-2026. [PMID: 38534746 DOI: 10.3390/cimb46030130] [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: 02/14/2024] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/28/2024] Open
Abstract
Mitochondria are thought to have become incorporated within the eukaryotic cell approximately 2 billion years ago and play a role in a variety of cellular processes, such as energy production, calcium buffering and homeostasis, steroid synthesis, cell growth, and apoptosis, as well as inflammation and ROS production. Considering that mitochondria are involved in a multitude of cellular processes, mitochondrial dysfunction has been shown to play a role within several age-related diseases, including cancers, diabetes (type 2), and neurodegenerative diseases, although the underlying mechanisms are not entirely understood. The significant increase in lifespan and increased incidence of age-related diseases over recent decades has confirmed the necessity to understand the mechanisms by which mitochondrial dysfunction impacts the process of aging and age-related diseases. In this review, we will offer a brief overview of mitochondria, along with structure and function of this important organelle. We will then discuss the cause and consequence of mitochondrial dysfunction in the aging process, with a particular focus on its role in inflammation, cognitive decline, and neurodegenerative diseases, such as Huntington's disease, Parkinson's disease, and Alzheimer's disease. We will offer insight into therapies and interventions currently used to preserve or restore mitochondrial functioning during aging and neurodegeneration.
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Affiliation(s)
- Sydney Bartman
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - Giuseppe Coppotelli
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - Jaime M Ross
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
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5
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Dong X, Li Y, Sheng X, Zhou W, Sun A, Dai H. Mitochondria-related signaling pathways involved in breast cancer regulate ferroptosis. Genes Dis 2024; 11:358-366. [PMID: 37588231 PMCID: PMC10425853 DOI: 10.1016/j.gendis.2023.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/20/2023] [Accepted: 03/11/2023] [Indexed: 08/18/2023] Open
Abstract
Ferroptosis is a novel form of regulated cell death characterized by iron-dependent excessive lipid peroxidation. The core organelle involved in ferroptosis is mitochondria. Mitochondria undergoing ferroptosis are distinct from normal mitochondria in terms of morphology, biochemistry, gene expression, and energy metabolism. An increasing number of studies have shown that mitochondria and their associated metabolic pathways mediate ferroptosis in the development and progression of breast cancer. In this review, we discuss the relevant research about ferroptosis in breast cancer and provide a comprehensive summary of mitochondrial regulation in ferroptosis from the perspective of lipid metabolism, oxidative phosphorylation, ion metabolism, glycometabolism, and nucleotide metabolism. We also summarize the application of mitochondrial metabolism-related pathways as ferroptosis treatment targets. Here we provide new insights into the relationship between mitochondria, ferroptosis, and breast cancer treatment.
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Affiliation(s)
- Xinrui Dong
- Department of Breast Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Ye Li
- Department of Breast Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Xiaonan Sheng
- Department of Breast Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Weihang Zhou
- Department of Breast Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Aijun Sun
- Department of Thyroid and Breast Oncological Surgery, Xuzhou Medical College Affiliated Huaian Hospital, Huai'an, Jiangsu 223001, China
| | - Huijuan Dai
- Department of Breast Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
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6
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Berezhkovskii AM, Bezrukov SM. Counter-Intuitive Features of Particle Dynamics in Nanopores. Int J Mol Sci 2023; 24:15923. [PMID: 37958906 PMCID: PMC10648703 DOI: 10.3390/ijms242115923] [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: 09/22/2023] [Revised: 10/27/2023] [Accepted: 10/29/2023] [Indexed: 11/15/2023] Open
Abstract
Using the framework of a continuous diffusion model based on the Smoluchowski equation, we analyze particle dynamics in the confinement of a transmembrane nanopore. We briefly review existing analytical results to highlight consequences of interactions between the channel nanopore and the translocating particles. These interactions are described within a minimalistic approach by lumping together multiple physical forces acting on the particle in the pore into a one-dimensional potential of mean force. Such radical simplification allows us to obtain transparent analytical results, often in a simple algebraic form. While most of our findings are quite intuitive, some of them may seem unexpected and even surprising at first glance. The focus is on five examples: (i) attractive interactions between the particles and the nanopore create a potential well and thus cause the particles to spend more time in the pore but, nevertheless, increase their net flux; (ii) if the potential well-describing particle-pore interaction occupies only a part of the pore length, the mean translocation time is a non-monotonic function of the well length, first increasing and then decreasing with the length; (iii) when a rectangular potential well occupies the entire nanopore, the mean particle residence time in the pore is independent of the particle diffusivity inside the pore and depends only on its diffusivity in the bulk; (iv) although in the presence of a potential bias applied to the nanopore the "downhill" particle flux is higher than the "uphill" one, the mean translocation times and their distributions are identical, i.e., independent of the translocation direction; and (v) fast spontaneous gating affects nanopore selectivity when its characteristic time is comparable to that of the particle transport through the pore.
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Affiliation(s)
| | - Sergey M. Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
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7
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Ventura C, Junco M, Santiago Valtierra FX, Gooz M, Zhiwei Y, Townsend DM, Woster PM, Maldonado EN. Synergism of small molecules targeting VDAC with sorafenib, regorafenib or lenvatinib on hepatocarcinoma cell proliferation and survival. Eur J Pharmacol 2023; 957:176034. [PMID: 37652292 PMCID: PMC10586475 DOI: 10.1016/j.ejphar.2023.176034] [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: 05/14/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
Voltage dependent anion channels (VDAC) in the outer mitochondrial membrane regulate the influx of metabolites that sustain mitochondrial metabolism and the efflux of ATP to the cytosol. Free tubulin and NADH close VDAC. The VDAC-binding small molecules X1 and SC18 modulate mitochondrial metabolism. X1 antagonizes the inhibitory effect of tubulin on VDAC. SC18 occupies an NADH-binding pocket in the inner wall of all VDAC isoforms. Here, we hypothesized that X1 and SC18 have a synergistic effect with sorafenib, regorafenib or lenvatinib to arrest proliferation and induce death in hepatocarcinoma cells. We used colony formation assays to determine cell proliferation, and a combination of calcein/propidium iodide, and trypan blue exclusion to assess cell death in the well differentiated Huh7 and the poorly differentiated SNU-449 cells. Synergism was assessed using the Chou-Talalay method. The inhibitory effect of X1, SC18, sorafenib, regorafenib and lenvatinib was concentration and time dependent. IC50s calculated from the inhibition of clonogenic capacity were lower than those determined from cell survival. At IC50s that inhibited cell proliferation, SC18 arrested cells in G0/G1. SC18 at 0.25-2 IC50s had a synergistic effect with sorafenib on clonogenic inhibition in Huh7 and SNU-449 cells, and with regorafenib or lenvatinib in SNU-449 cells. X1 or SC18 also had synergistic effects with sorafenib on promoting cell death at 0.5-2 IC50s for SC18 in Huh7 and SNU-449 cells. These results suggest that small molecules targeting VDAC represent a potential new class of drugs to treat liver cancer.
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Affiliation(s)
- C Ventura
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA; Institute for Immunological and Physiopathological Studies (IIFP), National Scientific and Technical Research Council (CONICET), Argentina
| | - M Junco
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - F X Santiago Valtierra
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - M Gooz
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Y Zhiwei
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - D M Townsend
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - P M Woster
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - E N Maldonado
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
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Kostenko S, Khatua B, Trivedi S, Pillai AN, McFayden B, Morsy M, Rajalingamgari P, Sharma V, Noel P, Patel K, El-Kurdi B, Borges da Silva H, Chen X, Chandan V, Navina S, Vela S, Cartin-Ceba R, Snozek C, Singh VP. Amphipathic Liponecrosis Impairs Bacterial Clearance and Causes Infection During Sterile Inflammation. Gastroenterology 2023; 165:999-1015. [PMID: 37263302 DOI: 10.1053/j.gastro.2023.05.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/04/2023] [Accepted: 05/15/2023] [Indexed: 06/03/2023]
Abstract
BACKGROUND & AIMS Although transient bacteremia is common during dental and endoscopic procedures, infections developing during sterile diseases like acute pancreatitis (AP) can have grave consequences. We examined how impaired bacterial clearance may cause this transition. METHODS Blood samples from patients with AP, normal controls, and rodents with pancreatitis or those administered different nonesterified fatty acids (NEFAs) were analyzed for albumin-unbound NEFAs, microbiome, and inflammatory cell injury. Macrophage uptake of unbound NEFAs using a novel coumarin tracer were done and the downstream effects-NEFA-membrane phospholipid (phosphatidylcholine) interactions-were studied on isothermal titration calorimetry. RESULTS Patients with infected AP had higher circulating unsaturated NEFAs; unbound NEFAs, including linoleic acid (LA) and oleic acid (OA); higher bacterial 16S DNA; mitochondrial DNA; altered β-diversity; enrichment in Pseudomonadales; and increased annexin V-positive myeloid (CD14) and CD3-positive T cells on admission. These, and increased circulating dead inflammatory cells, were also noted in rodents with unbound, unsaturated NEFAs. Isothermal titration calorimetry showed progressively stronger unbound LA interactions with aqueous media, phosphatidylcholine, cardiolipin, and albumin. Unbound NEFAs were taken into protein-free membranes, cells, and mitochondria, inducing voltage-dependent anion channel oligomerization, reducing ATP, and impairing phagocytosis. These were reversed by albumin. In vivo, unbound LA and OA increased bacterial loads and impaired phagocytosis, causing infection. LA and OA were more potent for these amphipathic interactions than the hydrophobic palmitic acid. CONCLUSIONS Release of stored LA and OA can increase their circulating unbound levels and cause amphipathic liponecrosis of immune cells via uptake by membrane phospholipids. This impairs bacterial clearance and causes infection during sterile inflammation.
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Affiliation(s)
| | | | | | | | - Bryce McFayden
- Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Mahmoud Morsy
- Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | | | - Vijeta Sharma
- Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Pawan Noel
- Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Krutika Patel
- Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Bara El-Kurdi
- Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | | | - Xianfeng Chen
- Department of Research Services, Mayo Clinic, Rochester, Minnesota
| | - Vishal Chandan
- Department of Pathology, School of Medicine, University of California, Irvine, California
| | | | - Stacie Vela
- Gastroenterology Section, Carl T. Hayden Veterans' Administration Medical Center, Phoenix, Arizona
| | - Rodrigo Cartin-Ceba
- Department of Pulmonary and Critical Care Medicine, Mayo Clinic, Scottsdale, Arizona
| | - Christine Snozek
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona
| | - Vijay P Singh
- Department of Medicine, Mayo Clinic, Rochester, Minnesota; Department of Biochemistry and Molecular Biology, Mayo Clinic, Scottsdale, Arizona.
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9
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Bora JR, Mahalakshmi R. Photoradical-Mediated Catalyst-Independent Protein Cross-Link with Unusual Fluorescence Properties. Chembiochem 2023; 24:e202300380. [PMID: 37232210 PMCID: PMC7615464 DOI: 10.1002/cbic.202300380] [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] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 05/27/2023]
Abstract
Photo-actively modified natural amino acids have served as lucrative probes for precise mapping of the dynamics, interaction networks, and turnover of cytosolic proteins both in vivo and ex vivo. In our attempts to extend the utility of photoreactive reporters to map the molecular characteristics of vital membrane proteins, we carried out site-selective incorporation of 7-fluoro-indole in the human mitochondrial outer membrane protein VDAC2 (voltage-dependent anion channel isoform 2), with the aim of generating Trp-Phe/Tyr cross-links. Prolonged irradiation at 282 nm provided us with a surprisingly unusual fluorophore that displayed sizably red-shifted excitation (λex-max =280 nm→360 nm) and emission (λem-max =330 nm→430 nm) spectra that was reversible with organic solvents. By measuring the kinetics of the photo-activated cross-linking with a library of hVDAC2 variants, we demonstrate that formation of this unusual fluorophore is kinetically retarded, independent of tryptophan, and is site-specific. Using other membrane (Tom40 and Sam50) and cytosolic (MscR and DNA Pol I) proteins, we additionally show that formation of this fluorophore is protein-independent. Our findings reveal the photoradical-mediated accumulation of reversible tyrosine cross-links, with unusual fluorescent properties. Our findings have immediate applications in protein biochemistry and UV-mediated protein aggregation and cellular damage, opening avenues for formulating therapeutics that prolong cell viability in humans.
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Affiliation(s)
- Jinam Ravindra Bora
- Molecular Biophysics Laboratory Department of Biological Sciences Indian Institute of Science Education and Research Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh (India)
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory Department of Biological Sciences Indian Institute of Science Education and Research Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh (India)
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10
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Greiser M, Karbowski M, Kaplan AD, Coleman AK, Verhoeven N, Mannella CA, Lederer WJ, Boyman L. Calcium and bicarbonate signaling pathways have pivotal, resonating roles in matching ATP production to demand. eLife 2023; 12:e84204. [PMID: 37272417 PMCID: PMC10284600 DOI: 10.7554/elife.84204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 06/01/2023] [Indexed: 06/06/2023] Open
Abstract
Mitochondrial ATP production in ventricular cardiomyocytes must be continually adjusted to rapidly replenish the ATP consumed by the working heart. Two systems are known to be critical in this regulation: mitochondrial matrix Ca2+ ([Ca2+]m) and blood flow that is tuned by local cardiomyocyte metabolic signaling. However, these two regulatory systems do not fully account for the physiological range of ATP consumption observed. We report here on the identity, location, and signaling cascade of a third regulatory system -- CO2/bicarbonate. CO2 is generated in the mitochondrial matrix as a metabolic waste product of the oxidation of nutrients. It is a lipid soluble gas that rapidly permeates the inner mitochondrial membrane and produces bicarbonate in a reaction accelerated by carbonic anhydrase. The bicarbonate level is tracked physiologically by a bicarbonate-activated soluble adenylyl cyclase (sAC). Using structural Airyscan super-resolution imaging and functional measurements we find that sAC is primarily inside the mitochondria of ventricular cardiomyocytes where it generates cAMP when activated by bicarbonate. Our data strongly suggest that ATP production in these mitochondria is regulated by this cAMP signaling cascade operating within the inter-membrane space by activating local EPAC1 (Exchange Protein directly Activated by cAMP) which turns on Rap1 (Ras-related protein-1). Thus, mitochondrial ATP production is increased by bicarbonate-triggered sAC-signaling through Rap1. Additional evidence is presented indicating that the cAMP signaling itself does not occur directly in the matrix. We also show that this third signaling process involving bicarbonate and sAC activates the mitochondrial ATP production machinery by working independently of, yet in conjunction with, [Ca2+]m-dependent ATP production to meet the energy needs of cellular activity in both health and disease. We propose that the bicarbonate and calcium signaling arms function in a resonant or complementary manner to match mitochondrial ATP production to the full range of energy consumption in ventricular cardiomyocytes.
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Affiliation(s)
- Maura Greiser
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
- Claude D. Pepper Older Americans Independence Center, University of Maryland School of MedicineBaltimoreUnited States
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Biochemistry and Molecular Biology, University of Maryland School of MedicineBaltimoreUnited States
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Baltimore School of MedicineBaltimoreUnited States
| | - Aaron David Kaplan
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of MedicineBaltimoreUnited States
| | - Andrew Kyle Coleman
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
| | - Nicolas Verhoeven
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Biochemistry and Molecular Biology, University of Maryland School of MedicineBaltimoreUnited States
| | - Carmen A Mannella
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Baltimore School of MedicineBaltimoreUnited States
| | - Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Baltimore School of MedicineBaltimoreUnited States
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11
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Mannella C. In Silico Exploration of Alternative Conformational States of VDAC. Molecules 2023; 28:molecules28083309. [PMID: 37110543 PMCID: PMC10144127 DOI: 10.3390/molecules28083309] [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: 03/22/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
VDAC (Voltage-Dependent Anion-selective Channel) is the primary metabolite pore in the mitochondrial outer membrane (OM). Atomic structures of VDAC, consistent with its physiological "open" state, are β-barrels formed by 19 transmembrane (TM) β-strands and an N-terminal segment (NTERM) that folds inside the pore lumen. However, structures are lacking for VDAC's partially "closed" states. To provide clues about possible VDAC conformers, we used the RoseTTAFold neural network to predict structures for human and fungal VDAC sequences modified to mimic removal from the pore wall or lumen of "cryptic" domains, i.e., segments buried in atomic models yet accessible to antibodies in OM-bound VDAC. Predicted in vacuo structures for full-length VDAC sequences are 19-strand β-barrels similar to atomic models, but with weaker H-bonding between TM strands and reduced interactions between NTERM and the pore wall. Excision of combinations of "cryptic" subregions yields β-barrels with smaller diameters, wide gaps between N- and C-terminal β-strands, and in some cases disruption of the β-sheet (associated with strained backbone H-bond registration). Tandem repeats of modified VDAC sequences also were explored, as was domain swapping in monomer constructs. Implications of the results for possible alternative conformational states of VDAC are discussed.
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Affiliation(s)
- Carmen Mannella
- Department of Physiology and Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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12
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Allon I, Pettesh J, Livoff A, Schlapobersky M, Nahlieli O, Michaeli E. Voltage-Dependent Anion Channel 1 Expression in Oral Malignant and Premalignant Lesions. Diagnostics (Basel) 2023; 13:diagnostics13071225. [PMID: 37046443 PMCID: PMC10093190 DOI: 10.3390/diagnostics13071225] [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: 02/14/2023] [Revised: 03/19/2023] [Accepted: 03/20/2023] [Indexed: 04/14/2023] Open
Abstract
BACKGROUND The voltage-dependent anion channel 1 protein (VDAC1) plays a role in cellular metabolism and survival. It was found to be down or upregulated (overexpressed) in different malignancies but it was never studied in application to oral lesions. The purpose of this study was to retrospectively evaluate the expression of VDAC1 in biopsies of oral premalignant, malignant, and malignancy-neutral lesions and to examine the possible correlations to their clinicopathological parameters. MATERIALS AND METHODS 103 biopsies including 49 oral squamous cell carcinoma, 33 epithelial dysplasia, and 21 fibrous hyperplasia samples were immunohistochemically stained with anti-VDAC1 antibodies for semi-quantitative evaluation. The antibody detection was performed with 3,3'-diaminobenzidine (DAB). The clinicopathological information was examined for possible correlations with VDAC1. RESULTS VDAC1 expression was lower in oral squamous cell carcinoma 0.63 ± 0.40 and in oral epithelial dysplasia 0.61 ± 0.36 biopsies compared to fibrous hyperplasia biopsies 1.45 ± 0.28 (p < 0.01 for both; Kruskal-Wallis test). CONCLUSION Oral squamous cell carcinoma and epithelial dysplasia tissues demonstrated decreased VDAC1 protein expression if compared to fibrous hyperplasia samples, but were not different from each other, suggesting that the involvement of VDAC1 in oral carcinogenesis is an early stage event, regulating cells to live or die.
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Affiliation(s)
- Irit Allon
- Institute of Pathology, Barzilai University Medical Center, Ashkelon 7830604, Israel
- School of Health Sciences, The Ben-Gurion University of the Negev, Beer-Sheba 84105, Israel
| | - Jacob Pettesh
- Oral Medicine Unit, Barzilai University Medical Center, Ashkelon 7830604, Israel
| | - Alejandro Livoff
- Institute of Pathology, Barzilai University Medical Center, Ashkelon 7830604, Israel
| | - Mark Schlapobersky
- Institute of Pathology, Barzilai University Medical Center, Ashkelon 7830604, Israel
| | - Oded Nahlieli
- School of Health Sciences, The Ben-Gurion University of the Negev, Beer-Sheba 84105, Israel
- Department of Oral & Maxillofacial Surgery, Barzilai University Medical Center, Ashkelon 7830604, Israel
| | - Eli Michaeli
- School of Health Sciences, The Ben-Gurion University of the Negev, Beer-Sheba 84105, Israel
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13
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Magrì A, Cubisino SAM, Battiato G, Lipari CLR, Conti Nibali S, Saab MW, Pittalà A, Amorini AM, De Pinto V, Messina A. VDAC1 Knockout Affects Mitochondrial Oxygen Consumption Triggering a Rearrangement of ETC by Impacting on Complex I Activity. Int J Mol Sci 2023; 24:ijms24043687. [PMID: 36835102 PMCID: PMC9963415 DOI: 10.3390/ijms24043687] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 02/04/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
Voltage-Dependent Anion-selective Channel isoform 1 (VDAC1) is the most abundant isoform of the outer mitochondrial membrane (OMM) porins and the principal gate for ions and metabolites to and from the organelle. VDAC1 is also involved in a number of additional functions, such as the regulation of apoptosis. Although the protein is not directly involved in mitochondrial respiration, its deletion in yeast triggers a complete rewiring of the whole cell metabolism, with the inactivation of the main mitochondrial functions. In this work, we analyzed in detail the impact of VDAC1 knockout on mitochondrial respiration in the near-haploid human cell line HAP1. Results indicate that, despite the presence of other VDAC isoforms in the cell, the inactivation of VDAC1 correlates with a dramatic impairment in oxygen consumption and a re-organization of the relative contributions of the electron transport chain (ETC) enzymes. Precisely, in VDAC1 knockout HAP1 cells, the complex I-linked respiration (N-pathway) is increased by drawing resources from respiratory reserves. Overall, the data reported here strengthen the key role of VDAC1 as a general regulator of mitochondrial metabolism.
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Affiliation(s)
- Andrea Magrì
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via S. Sofia 64, 95125 Catania, Italy
- we.MitoBiotech S.R.L., C.so Italia 174, 95125 Catania, Italy
- Correspondence:
| | | | - Giuseppe Battiato
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 64, 95125 Catania, Italy
| | - Cristiana Lucia Rita Lipari
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 64, 95125 Catania, Italy
| | - Stefano Conti Nibali
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 64, 95125 Catania, Italy
| | - Miriam Wissam Saab
- Department of Biomedical and Biotechnological Sciences, Division of Medical Biochemistry, University of Catania, Via S. Sofia 97, 95123 Catania, Italy
| | - Alessandra Pittalà
- Department of Biomedical and Biotechnological Sciences, Division of Medical Biochemistry, University of Catania, Via S. Sofia 97, 95123 Catania, Italy
| | - Angela Maria Amorini
- Department of Biomedical and Biotechnological Sciences, Division of Medical Biochemistry, University of Catania, Via S. Sofia 97, 95123 Catania, Italy
| | - Vito De Pinto
- we.MitoBiotech S.R.L., C.so Italia 174, 95125 Catania, Italy
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 64, 95125 Catania, Italy
| | - Angela Messina
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via S. Sofia 64, 95125 Catania, Italy
- we.MitoBiotech S.R.L., C.so Italia 174, 95125 Catania, Italy
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14
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Reduced mitochondria provide an essential function for the cytosolic methionine cycle. Curr Biol 2022; 32:5057-5068.e5. [PMID: 36347252 PMCID: PMC9746703 DOI: 10.1016/j.cub.2022.10.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/15/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022]
Abstract
The loss of mitochondria in oxymonad protists has been associated with the redirection of the essential Fe-S cluster assembly to the cytosol. Yet as our knowledge of diverse free-living protists broadens, the list of functions of their mitochondrial-related organelles (MROs) expands. We revealed another such function in the closest oxymonad relative, Paratrimastix pyriformis, after we solved the proteome of its MRO with high accuracy, using localization of organelle proteins by isotope tagging (LOPIT). The newly assigned enzymes connect to the glycine cleavage system (GCS) and produce folate derivatives with one-carbon units and formate. These are likely to be used by the cytosolic methionine cycle involved in S-adenosyl methionine recycling. The data provide consistency with the presence of the GCS in MROs of free-living species and its absence in most endobionts, which typically lose the methionine cycle and, in the case of oxymonads, the mitochondria.
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15
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Rosa N, Speelman-Rooms F, Parys JB, Bultynck G. Modulation of Ca 2+ signaling by antiapoptotic Bcl-2 versus Bcl-xL: From molecular mechanisms to relevance for cancer cell survival. Biochim Biophys Acta Rev Cancer 2022; 1877:188791. [PMID: 36162541 DOI: 10.1016/j.bbcan.2022.188791] [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: 06/08/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022]
Abstract
Members of the Bcl-2-protein family are key controllers of apoptotic cell death. The family is divided into antiapoptotic (including Bcl-2 itself, Bcl-xL, Mcl-1, etc.) and proapoptotic members (Bax, Bak, Bim, Bim, Puma, Noxa, Bad, etc.). These proteins are well known for their canonical role in the mitochondria, where they control mitochondrial outer membrane permeabilization and subsequent apoptosis. However, several proteins are recognized as modulators of intracellular Ca2+ signals that originate from the endoplasmic reticulum (ER), the major intracellular Ca2+-storage organelle. More than 25 years ago, Bcl-2, the founding member of the family, was reported to control apoptosis through Ca2+ signaling. Further work elucidated that Bcl-2 directly targets and inhibits inositol 1,4,5-trisphosphate receptors (IP3Rs), thereby suppressing proapoptotic Ca2+ signaling. In addition to Bcl-2, Bcl-xL was also shown to impact cell survival by sensitizing IP3R function, thereby promoting prosurvival oscillatory Ca2+ release. However, new work challenges this model and demonstrates that Bcl-2 and Bcl-xL can both function as inhibitors of IP3Rs. This suggests that, depending on the cell context, Bcl-xL could support very distinct Ca2+ patterns. This not only raises several questions but also opens new possibilities for the treatment of Bcl-xL-dependent cancers. In this review, we will discuss the similarities and divergences between Bcl-2 and Bcl-xL regarding Ca2+ homeostasis and IP3R modulation from both a molecular and a functional point of view, with particular emphasis on cancer cell death resistance mechanisms.
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Affiliation(s)
- Nicolas Rosa
- KU Leuven, Laboratory of Molecular & Cellular Signaling, Department of Cellular & Molecular Medicine, Campus Gasthuisberg O/N-I bus 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Femke Speelman-Rooms
- KU Leuven, Laboratory of Molecular & Cellular Signaling, Department of Cellular & Molecular Medicine, Campus Gasthuisberg O/N-I bus 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular & Cellular Signaling, Department of Cellular & Molecular Medicine, Campus Gasthuisberg O/N-I bus 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular & Cellular Signaling, Department of Cellular & Molecular Medicine, Campus Gasthuisberg O/N-I bus 802, Herestraat 49, BE-3000 Leuven, Belgium.
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16
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Liu J, Yang J. Mitochondria-associated membranes: A hub for neurodegenerative diseases. Biomed Pharmacother 2022; 149:112890. [PMID: 35367757 DOI: 10.1016/j.biopha.2022.112890] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/24/2022] [Accepted: 03/24/2022] [Indexed: 11/02/2022] Open
Abstract
In eukaryotic cells, organelles could coordinate complex mechanisms of signaling transduction metabolism and gene expression through their functional interactions. The functional domain between ER and mitochondria, called mitochondria-associated membranes (MAM), is closely associated with various physiological functions including intracellular lipid transport, Ca2+ transfer, mitochondria function maintenance, and autophagosome formation. In addition, more evidence suggests that MAM modulate cellular functions in health and disease. Studies have also demonstrated the association of MAM with numerous diseases, including neurodegenerative diseases, cancer, viral infection, obesity, and diabetes. In fact, recent evidence revealed a close relationship of MAM with Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), and other neurodegenerative diseases. In this view, elucidating the role of MAM in neurodegenerative diseases is particularly important. This review will focus the main tethering protein complexes of MAM and functions of MAM. Besides, the role of MAM in the regulation of neurodegenerative diseases and the potential molecular mechanisms is introduced to provide a new understanding of the pathogenesis of these diseases.
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Affiliation(s)
- Jinxuan Liu
- Department of Toxicology, School of Public Health, China Medical University, NO.77 Puhe road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.
| | - Jinghua Yang
- Department of Toxicology, School of Public Health, China Medical University, NO.77 Puhe road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.
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17
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Magalingam KB, Somanath SD, Ramdas P, Haleagrahara N, Radhakrishnan AK. 6-Hydroxydopamine Induces Neurodegeneration in Terminally Differentiated SH-SY5Y Neuroblastoma Cells via Enrichment of the Nucleosomal Degradation Pathway: a Global Proteomics Approach. J Mol Neurosci 2022; 72:1026-1046. [PMID: 35258800 PMCID: PMC9064865 DOI: 10.1007/s12031-021-01962-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 12/22/2021] [Indexed: 01/07/2023]
Abstract
The SH-SY5Y human neuroblastoma cells have been used for decades as a cell-based model of dopaminergic neurons to explore the underlying science of cellular and molecular mechanisms of neurodegeneration in Parkinson’s disease (PD). However, data revealing the protein expression changes in 6-OHDA induced cytotoxicity in differentiated SH-SY5Y cells remain void. Therefore, we investigated the differentially regulated proteins expressed in terminally differentiated SH-SY5Y cells (differ-SH-SY5Y neural cells) exposed to 6-hydroxydopamine (6-OHDA) using the LC–MS/MS technology and construed the data using the online bioinformatics databases such as PANTHER, STRING, and KEGG. Our studies demonstrated that the neuronal development in differ-SH-SY5Y neural cells was indicated by the overexpression of proteins responsible for neurite formations such as calnexin (CANX) and calreticulin (CALR) besides significant downregulation of ribosomal proteins. The enrichment of the KEGG ribosome pathway was detected with significant downregulation (p < 0.05) of all the 21 ribosomal proteins in differ-SH-SY5Y neural cells compared with undifferentiated cells. Whereas in the PD model, the pathological changes induced by 6-OHDA were indicated by the presence of unfolded and misfolded proteins, which triggered the response of 10 kDa heat shock proteins (HSP), namely HSPE1 and HSPA9. Moreover, the 6-OHDA-induced neurodegeneration in differ-SH-SY5Y neural cells also upregulated the voltage-dependent anion-selective channel protein 1 (VDAC1) protein and enriched the KEGG systemic lupus erythematosus (SLE) pathway that was regulated by 17 histone proteins (p < 0.05) in differ-SH-SY5Y neural cells. These results suggest that the nucleosomal degradation pathway may have regulated the 6-OHDA induced neurodegeneration in PD cell-based model, which is reflected by increased apoptosis and histone release in differ-SH-SY5Y neural cells.
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Affiliation(s)
- Kasthuri Bai Magalingam
- School of Postgraduate Studies, International Medical University, Kuala Lumpur, Malaysia
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University, Malaysia, Bandar Sunway, Malaysia
| | - Sushela Devi Somanath
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Premdass Ramdas
- Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Nagaraja Haleagrahara
- College of Public Health, Medicine and Veterinary Sciences, James Cook University, Townsville, QLD, 4811, Australia
| | - Ammu Kutty Radhakrishnan
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University, Malaysia, Bandar Sunway, Malaysia.
- Monash-Industry Palm Oil Education and Research Platform (MIPO), Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
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18
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Homocysteine-Thiolactone Modulates Gating of Mitochondrial Voltage-Dependent Anion Channel (VDAC) and Protects It from Induced Oxidative Stress. J Membr Biol 2022; 255:79-97. [PMID: 35103807 DOI: 10.1007/s00232-022-00215-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/10/2022] [Indexed: 12/26/2022]
Abstract
The gating of the Voltage-Dependent Anion Channel (VDAC) is linked to oxidative stress through increased generation of mitochondrial ROS with increasing mitochondrial membrane potential (ΔΨm). It has been already reported that H2O2 increases the single-channel conductance of VDAC on a bilayer lipid membrane. On the other hand, homocysteine (Hcy) has been reported to induce mitochondria-mediated cell death. It is argued that the thiol-form of homocysteine, HTL could be the plausible molecule responsible for the alteration in the function of proteins, such as VDAC. It is hypothesized that HTL interacts with VDAC that causes functional abnormalities. An investigation was undertaken to study the interaction of HTL with VDAC under H2O2 induced oxidative stress through biophysical and electrophysiological methods. Fluorescence spectroscopic studies indicate that HTL interacts with VDAC, but under induced oxidative stress the effect is prevented partially. Similarly, bilayer electrophysiology studies suggest that HTL shows a reduction in VDAC single-channel conductance, but the effects are partially prevented under an oxidative environment. Gly172 and His181 are predicted through bioinformatics tools to be the most plausible binding residues of HTL in Rat VDAC. The binding of HTL and H2O2 with VDAC appears to be cooperative as per our analysis of experimental data in the light of the Hill-Langmuir equation. The binding energies are estimated to be - 4.7 kcal mol-1 and - 2.8 kcal mol-1, respectively. The present in vitro studies suggest that when mitochondrial VDAC is under oxidative stress, the effects of amino acid metabolites like HTL are suppressed.
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19
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Preto J, Gorny H, Krimm I. A Deep Dive into VDAC1 Conformational Diversity Using All-Atom Simulations Provides New Insights into the Structural Origin of the Closed States. Int J Mol Sci 2022; 23:ijms23031175. [PMID: 35163095 PMCID: PMC8834982 DOI: 10.3390/ijms23031175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/13/2022] [Accepted: 01/19/2022] [Indexed: 01/14/2023] Open
Abstract
The voltage-dependent anion channel 1 (VDAC1) is a crucial mitochondrial transporter that controls the flow of ions and respiratory metabolites entering or exiting mitochondria. As a voltage-gated channel, VDAC1 can switch between a high-conducting “open” state and a low-conducting “closed” state emerging at high transmembrane (TM) potentials. Although cell homeostasis depends on channel gating to regulate the transport of ions and metabolites, structural hallmarks characterizing the closed states remain unknown. Here, we performed microsecond accelerated molecular dynamics to highlight a vast region of VDAC1 conformational landscape accessible at typical voltages known to promote closure. Conformers exhibiting durable subconducting properties inherent to closed states were identified. In all cases, the low conductance was due to the particular positioning of an unfolded part of the N-terminus, which obstructed the channel pore. While the N-terminal tail was found to be sensitive to voltage orientation, our models suggest that stable low-conducting states of VDAC1 predominantly take place from disordered events and do not result from the displacement of a voltage sensor or a significant change in the pore. In addition, our results were consistent with conductance jumps observed experimentally and corroborated a recent study describing entropy as a key factor for VDAC gating.
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20
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Proteomic Shifts Reflecting Oxidative Stress and Reduced Capacity for Protein Synthesis, and Alterations to Mitochondrial Membranes in Neurospora crassa Lacking VDAC. Microorganisms 2022; 10:microorganisms10020198. [PMID: 35208654 PMCID: PMC8877502 DOI: 10.3390/microorganisms10020198] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 11/24/2022] Open
Abstract
Voltage-dependent anion-selective channels (VDAC) maintain the bidirectional flow of small metabolites across the mitochondrial outer membrane and participate in the regulation of multiple cellular processes. To understand the roles of VDAC in cellular homeostasis, preliminary proteomic analyses of S100 cytosolic and mitochondria-enriched fractions from a VDAC-less Neurospora crassa strain (ΔPor-1) were performed. In the variant cells, less abundant proteins include subunits of translation initiation factor eIF-2, enzymes in the shikimate pathway leading to precursors of aromatic amino acids, and enzymes involved in sulfate assimilation and in the synthesis of methionine, cysteine, alanine, serine, and threonine. In contrast, some of the more abundant proteins are involved in electron flow, such as the α subunit of the electron transfer flavoprotein and lactate dehydrogenase, which is involved in one pathway leading to pyruvate synthesis. Increased levels of catalase and catalase activity support predicted increased levels of oxidative stress in ΔPor-1 cells, and higher levels of protein disulfide isomerase suggest activation of the unfolded protein response in the endoplasmic reticulum. ΔPor-1 cells are cold-sensitive, which led us to investigate the impact of the absence of VDAC on several mitochondrial membrane characteristics. Mitochondrial membranes in ΔPor-1 are more fluid than those of wild-type cells, the ratio of C18:1 to C18:3n3 acyl chains is reduced, and ergosterol levels are lower. In summary, these initial results indicate that VDAC-less N. crassa cells are characterized by a lower abundance of proteins involved in amino acid and protein synthesis and by increases in some associated with pyruvate metabolism and stress responses. Membrane lipids and hyphal morphology are also impacted by the absence of VDAC.
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21
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Liu J, Wang L, Ge L, Sun W, Song Z, Lu X, Jin C, Wu S, Yang J. Lanthanum decreased VAPB-PTPP51, BAP31-FIS1, and MFN2-MFN1 expression of mitochondria-associated membranes and induced abnormal autophagy in rat hippocampus. Food Chem Toxicol 2022; 161:112831. [DOI: 10.1016/j.fct.2022.112831] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/03/2022] [Accepted: 01/20/2022] [Indexed: 12/21/2022]
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22
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Loh D, Reiter RJ. Melatonin: Regulation of Biomolecular Condensates in Neurodegenerative Disorders. Antioxidants (Basel) 2021; 10:1483. [PMID: 34573116 PMCID: PMC8465482 DOI: 10.3390/antiox10091483] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Biomolecular condensates are membraneless organelles (MLOs) that form dynamic, chemically distinct subcellular compartments organizing macromolecules such as proteins, RNA, and DNA in unicellular prokaryotic bacteria and complex eukaryotic cells. Separated from surrounding environments, MLOs in the nucleoplasm, cytoplasm, and mitochondria assemble by liquid-liquid phase separation (LLPS) into transient, non-static, liquid-like droplets that regulate essential molecular functions. LLPS is primarily controlled by post-translational modifications (PTMs) that fine-tune the balance between attractive and repulsive charge states and/or binding motifs of proteins. Aberrant phase separation due to dysregulated membrane lipid rafts and/or PTMs, as well as the absence of adequate hydrotropic small molecules such as ATP, or the presence of specific RNA proteins can cause pathological protein aggregation in neurodegenerative disorders. Melatonin may exert a dominant influence over phase separation in biomolecular condensates by optimizing membrane and MLO interdependent reactions through stabilizing lipid raft domains, reducing line tension, and maintaining negative membrane curvature and fluidity. As a potent antioxidant, melatonin protects cardiolipin and other membrane lipids from peroxidation cascades, supporting protein trafficking, signaling, ion channel activities, and ATPase functionality during condensate coacervation or dissolution. Melatonin may even control condensate LLPS through PTM and balance mRNA- and RNA-binding protein composition by regulating N6-methyladenosine (m6A) modifications. There is currently a lack of pharmaceuticals targeting neurodegenerative disorders via the regulation of phase separation. The potential of melatonin in the modulation of biomolecular condensate in the attenuation of aberrant condensate aggregation in neurodegenerative disorders is discussed in this review.
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Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX 78229, USA
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23
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Syrjanen J, Michalski K, Kawate T, Furukawa H. On the molecular nature of large-pore channels. J Mol Biol 2021; 433:166994. [PMID: 33865869 PMCID: PMC8409005 DOI: 10.1016/j.jmb.2021.166994] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 12/25/2022]
Abstract
Membrane transport is a fundamental means to control basic cellular processes such as apoptosis, inflammation, and neurodegeneration and is mediated by a number of transporters, pumps, and channels. Accumulating evidence over the last half century has shown that a type of so-called "large-pore channel" exists in various tissues and organs in gap-junctional and non-gap-junctional forms in order to flow not only ions but also metabolites such as ATP. They are formed by a number of protein families with little or no evolutionary linkages including connexin, innexin, pannexin, leucine-rich repeat-containing 8 (LRRC8), and calcium homeostasis modulator (CALHM). This review summarizes the history and concept of large-pore channels starting from connexin gap junction channels to the more recent developments in innexin, pannexin, LRRC8, and CALHM. We describe structural and functional features of large-pore channels that are crucial for their diverse functions on the basis of available structures.
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Affiliation(s)
- Johanna Syrjanen
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Kevin Michalski
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Toshimitsu Kawate
- Department of Molecular Medicine, Fields of Biochemistry, Molecular, and Cell Biology (BMCB), and Biophysics, Cornell University, Ithaca, NY 14853, USA
| | - Hiro Furukawa
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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24
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Molecular mechanism of thiamine pyrophosphate import into mitochondria: a molecular simulation study. J Comput Aided Mol Des 2021; 35:987-1007. [PMID: 34406552 DOI: 10.1007/s10822-021-00414-5] [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: 04/09/2021] [Accepted: 07/26/2021] [Indexed: 10/20/2022]
Abstract
The import of thiamine pyrophosphate (TPP) through both mitochondrial membranes was studied using a total of 3-µs molecular dynamics simulations. Regarding the translocation through the mitochondrial outer membrane, our simulations support the conjecture that TPP uses the voltage-dependent anion channel, the major pore of this membrane, for its passage to the intermembrane space, as its transport presents significant analogies with that used by other metabolites previously studied, in particular with ATP. As far as passing through the mitochondrial inner membrane is concerned, our simulations show that the specific carrier of TPP has a single binding site that becomes accessible, through an alternating access mechanism. The preference of this transporter for TPP can be rationalized mainly by three residues located in the binding site that differ from those identified in the ATP/ADP carrier, the most studied member of the mitochondrial carrier family. The simulated transport mechanism of TPP highlights the essential role, at the energetic level, of the contributions coming from the formation and breakage of two networks of salt bridges, one on the side of the matrix and the other on the side of the intermembrane space, as well as the interactions, mainly of an ionic nature, formed by TPP upon its binding. The energy contribution provided by the cytosolic network establishes a lower barrier than that of the matrix network, which can be explained by the lower interaction energy of TPP on the matrix side or possibly a uniport activity.
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25
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Puiggalí-Jou A, Molina BG, Lopes-Rodrigues M, Michaux C, Perpète EA, Zanuy D, Alemán C. Self-standing, conducting and capacitive biomimetic hybrid nanomembranes for selective molecular ion separation. Phys Chem Chem Phys 2021; 23:16157-16164. [PMID: 34297025 DOI: 10.1039/d1cp01840j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hybrid free-standing biomimetic materials are developed by integrating the VDAC36 β-barrel protein into robust and flexible three-layered polymer nanomembranes. The first and third layers are prepared by spin-coating a mixture of poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA). PVA nanofeatures are transformed into controlled nanoperforations by solvent-etching. The two nanoperforated PLA layers are separated by an electroactive layer, which is successfully electropolymerized by introducing a conducting sacrificial substrate under the first PLA nanosheet. Finally, the nanomaterial is consolidated by immobilizing the VDAC36 protein, active as an ion channel, into the nanoperforations of the upper layer. The integration of the protein causes a significant reduction of the material resistance, which decreases from 21.9 to 3.9 kΩ cm2. Electrochemical impedance spectroscopy studies using inorganic ions and molecular metabolites (i.e.l-lysine and ATP) not only reveal that the hybrid films behave as electrochemical supercapacitors but also indicate the most appropriate conditions to obtain selective responses against molecular ions as a function of their charge. The combination of polymers and proteins is promising for the development of new devices for engineering, biotechnological and biomedical applications.
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Affiliation(s)
- Anna Puiggalí-Jou
- Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya, C/Eduard Maristany 10-14, Edif. I2, 08019, Barcelona, Spain.
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26
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Mitostasis, Calcium and Free Radicals in Health, Aging and Neurodegeneration. Biomolecules 2021; 11:biom11071012. [PMID: 34356637 PMCID: PMC8301949 DOI: 10.3390/biom11071012] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 12/18/2022] Open
Abstract
Mitochondria play key roles in ATP supply, calcium homeostasis, redox balance control and apoptosis, which in neurons are fundamental for neurotransmission and to allow synaptic plasticity. Their functional integrity is maintained by mitostasis, a process that involves mitochondrial transport, anchoring, fusion and fission processes regulated by different signaling pathways but mainly by the peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). PGC-1α also favors Ca2+ homeostasis, reduces oxidative stress, modulates inflammatory processes and mobilizes mitochondria to where they are needed. To achieve their functions, mitochondria are tightly connected to the endoplasmic reticulum (ER) through specialized structures of the ER termed mitochondria-associated membranes (MAMs), which facilitate the communication between these two organelles mainly to aim Ca2+ buffering. Alterations in mitochondrial activity enhance reactive oxygen species (ROS) production, disturbing the physiological metabolism and causing cell damage. Furthermore, cytosolic Ca2+ overload results in an increase in mitochondrial Ca2+, resulting in mitochondrial dysfunction and the induction of mitochondrial permeability transition pore (mPTP) opening, leading to mitochondrial swelling and cell death through apoptosis as demonstrated in several neuropathologies. In summary, mitochondrial homeostasis is critical to maintain neuronal function; in fact, their regulation aims to improve neuronal viability and to protect against aging and neurodegenerative diseases.
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27
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Madec AM, Perrier J, Panthu B, Dingreville F. Role of mitochondria-associated endoplasmic reticulum membrane (MAMs) interactions and calcium exchange in the development of type 2 diabetes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 363:169-202. [PMID: 34392929 DOI: 10.1016/bs.ircmb.2021.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Glucotoxicity-induced β-cell dysfunction in type 2 diabetes is associated with alterations of mitochondria and the endoplasmic reticulum (ER). Mitochondria and ER form a network in cells that controls cell function and fate. Mitochondria of the pancreatic β cell play a central role in the secretion of insulin in response to glucose through their ability to produce ATP. Both organelles interact at contact sites, defined as mitochondria-associated membranes (MAMs), which were recently implicated in the regulation of glucose homeostasis. Here, we review MAM functions in the cell and we focus on the crosstalk between the ER and Mitochondria in the context of T2D, highlighting the pivotal role played by MAMs especially in β cells through inter-organelle calcium exchange and glucotoxicity-associated β cell dysfunction.
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Affiliation(s)
| | - Johan Perrier
- CarMeN Laboratory, INSERM U1060, INRA U1397, Lyon, France
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28
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Rostovtseva TK, Bezrukov SM, Hoogerheide DP. Regulation of Mitochondrial Respiration by VDAC Is Enhanced by Membrane-Bound Inhibitors with Disordered Polyanionic C-Terminal Domains. Int J Mol Sci 2021; 22:ijms22147358. [PMID: 34298976 PMCID: PMC8306229 DOI: 10.3390/ijms22147358] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 12/18/2022] Open
Abstract
The voltage-dependent anion channel (VDAC) is the primary regulating pathway of water-soluble metabolites and ions across the mitochondrial outer membrane. When reconstituted into lipid membranes, VDAC responds to sufficiently large transmembrane potentials by transitioning to gated states in which ATP/ADP flux is reduced and calcium flux is increased. Two otherwise unrelated cytosolic proteins, tubulin, and α-synuclein (αSyn), dock with VDAC by a novel mechanism in which the transmembrane potential draws their disordered, polyanionic C-terminal domains into and through the VDAC channel, thus physically blocking the pore. For both tubulin and αSyn, the blocked state is observed at much lower transmembrane potentials than VDAC gated states, such that in the presence of these cytosolic docking proteins, VDAC’s sensitivity to transmembrane potential is dramatically increased. Remarkably, the features of the VDAC gated states relevant for bioenergetics—reduced metabolite flux and increased calcium flux—are preserved in the blocked state induced by either docking protein. The ability of tubulin and αSyn to modulate mitochondrial potential and ATP production in vivo is now supported by many studies. The common physical origin of the interactions of both tubulin and αSyn with VDAC leads to a general model of a VDAC inhibitor, facilitates predictions of the effect of post-translational modifications of known inhibitors, and points the way toward the development of novel therapeutics targeting VDAC.
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Affiliation(s)
- Tatiana K. Rostovtseva
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
- Correspondence:
| | - Sergey M. Bezrukov
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
| | - David P. Hoogerheide
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA;
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29
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Di Rosa MC, Guarino F, Conti Nibali S, Magrì A, De Pinto V. Voltage-Dependent Anion Selective Channel Isoforms in Yeast: Expression, Structure, and Functions. Front Physiol 2021; 12:675708. [PMID: 34093236 PMCID: PMC8171188 DOI: 10.3389/fphys.2021.675708] [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: 03/03/2021] [Accepted: 04/20/2021] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial porins, also known as voltage-dependent anion selective channels (VDACs), are pore-forming molecules of the outer mitochondrial membranes, involved in the regulation of metabolic flux between cytosol and mitochondria. Playing such an essential role, VDAC proteins are evolutionary conserved and isoforms are present in numerous species. The quest for specific function(s) related to the raise of multiple isoforms is an intriguing theme. The yeast Saccharomyces cerevisiae genome is endowed with two different VDAC genes encoding for two distinct porin isoforms, definitely less characterized in comparison to mammalian counterpart. While yVDAC1 has been extensively studied, the second isoform, yVDAC2, is much less expressed, and has a still misunderstood function. This review will recapitulate the known and poorly known information in the literature, in the light of the growing interest about the features of VDAC isoforms in the cell.
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Affiliation(s)
- Maria Carmela Di Rosa
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Francesca Guarino
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.,we.MitoBiotech S.R.L., Catania, Italy
| | - Stefano Conti Nibali
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Andrea Magrì
- we.MitoBiotech S.R.L., Catania, Italy.,Department of Biological, Geological and Environmental Sciences, University of Catania, Catania, Italy
| | - Vito De Pinto
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.,we.MitoBiotech S.R.L., Catania, Italy
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30
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Alpha-Synuclein and Mitochondrial Dysfunction in Parkinson's Disease: The Emerging Role of VDAC. Biomolecules 2021; 11:biom11050718. [PMID: 34064816 PMCID: PMC8170894 DOI: 10.3390/biom11050718] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/05/2021] [Accepted: 05/08/2021] [Indexed: 12/12/2022] Open
Abstract
Alpha-Synuclein (αSyn) is a protein whose function is still debated, as well as its role in modulation of mitochondrial function in both physiological and pathological conditions. Mitochondrial porins or Voltage-Dependent Anion Channel (VDAC) proteins are the main gates for ADP/ATP and various substrates towards the organelle. Furthermore, they act as a mitochondrial hub for many cytosolic proteins, including αSyn. This review analyzes the main aspects of αSyn-mitochondria interaction, focusing on the role of VDAC and its emerging involvement in the pathological processes.
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31
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Nguyen TMD, Klett D, Combarnous Y. Fluoxetine affects cytosolic cAMP, ATP, Ca 2+ responses to forskolin, and survival of human ovarian granulosa tumor COV434 cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2021; 25:189-195. [PMID: 33859059 PMCID: PMC8050605 DOI: 10.4196/kjpp.2021.25.3.189] [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] [Received: 10/05/2020] [Revised: 11/18/2020] [Accepted: 01/07/2021] [Indexed: 12/03/2022]
Abstract
Fluoxetine (FLX), a selective serotonin reuptake inhibitor antidepressant, exhibits various other mechanisms of action in numerous cell types and has been shown to induce cell death in cancer cells, paving the way for its potential use in cancer therapy. The aim of this study was to determine the off-target effects of the anti-depressant drug FLX, on the human ovarian granulosa tumor COV434 cells stimulated by forskolin (FSK), by measuring the real-time kinetics of intracellular cyclic AMP (cAMP), ATP level, cytoplasmic calcium ([Ca2+]cyt) and survival of COV434 cells. We show that incubating COV434 cells with FLX (between 0.6 and 10 µM) induces a decrease in intracellular cAMP response to FSK, a drop in ATP content and stimulates cytoplasmic Ca2+ accumulation in COV434 cells. Only the highest concentrations of FLX (5–10 µM) diminished cell viability. The present report is the first to identify an action mechanism of FLX in human tumor ovarian cells COV434 cells and thus opening the way to potential use of fluoxetine as a complementary tool, in granulosa tumor treatments.
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Affiliation(s)
- Thi Mong Diep Nguyen
- Physiologie de la Reproduction & des Comportements Laboratory, Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique & Environnementale (INRAe), University of Tours, Nouzilly 37380, France.,Faculty of Natural Sciences, Quy Nhon University, Quy Nhon 820000, Vietnam
| | - Danièle Klett
- Physiologie de la Reproduction & des Comportements Laboratory, Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique & Environnementale (INRAe), University of Tours, Nouzilly 37380, France
| | - Yves Combarnous
- Physiologie de la Reproduction & des Comportements Laboratory, Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique & Environnementale (INRAe), University of Tours, Nouzilly 37380, France
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32
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Najbauer EE, Becker S, Giller K, Zweckstetter M, Lange A, Steinem C, de Groot BL, Griesinger C, Andreas LB. Structure, gating and interactions of the voltage-dependent anion channel. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2021; 50:159-172. [PMID: 33782728 PMCID: PMC8071794 DOI: 10.1007/s00249-021-01515-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 02/19/2021] [Accepted: 03/08/2021] [Indexed: 12/14/2022]
Abstract
The voltage-dependent anion channel (VDAC) is one of the most highly abundant proteins found in the outer mitochondrial membrane, and was one of the earliest discovered. Here we review progress in understanding VDAC function with a focus on its structure, discussing various models proposed for voltage gating as well as potential drug targets to modulate the channel’s function. In addition, we explore the sensitivity of VDAC structure to variations in the membrane environment, comparing DMPC-only, DMPC with cholesterol, and near-native lipid compositions, and use magic-angle spinning NMR spectroscopy to locate cholesterol on the outside of the β-barrel. We find that the VDAC protein structure remains unchanged in different membrane compositions, including conditions with cholesterol.
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Affiliation(s)
- Eszter E Najbauer
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Stefan Becker
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Karin Giller
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Markus Zweckstetter
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.,Senior Research Group of Translational Structural Biology in Dementia, Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany.,Department of Neurology, University Medical Center Göttingen, University of Göttingen, Waldweg 33, 37073, Göttingen, Germany
| | - Adam Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut Für Molekulare Pharmakologie, 13125, Berlin, Germany.,Institut Für Biologie, Humboldt-Universität Zu Berlin, 10115, Berlin, Germany
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany.,Max-Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Bert L de Groot
- Department of Theoretical and Computational Biophysics, Max-Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Christian Griesinger
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Loren B Andreas
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
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33
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Saidani H, Léonetti M, Kmita H, Homblé F. The Open State Selectivity of the Bean Seed VDAC Depends on Stigmasterol and Ion Concentration. Int J Mol Sci 2021; 22:ijms22063034. [PMID: 33809742 PMCID: PMC8002290 DOI: 10.3390/ijms22063034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 03/12/2021] [Indexed: 11/16/2022] Open
Abstract
The voltage-dependent anion channel (VDAC) is the major pathway for metabolites and ions transport through the mitochondrial outer membrane. It can regulate the flow of solutes by switching to a low conductance state correlated with a selectivity reversal, or by a selectivity inversion of its open state. The later one was observed in non-plant VDACs and is poorly characterized. We aim at investigating the selectivity inversion of the open state using plant VDAC purified from Phaseolus coccineus (PcVDAC) to evaluate its physiological role. Our main findings are: (1) The VDAC selectivity inversion of the open state occurs in PcVDAC, (2) Ion concentration and stigmasterol affect the occurrence of the open state selectivity inversion and stigmasterol appears to interact directly with PcVDAC. Interestingly, electrophysiological data concerning the selectivity inversion of the PcVDAC open state suggests that the phenomenon probably does not have a significant physiological effect in vivo.
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Affiliation(s)
- Hayet Saidani
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Boulevard du Triomphe CP 206/2, B-1050 Bruxelles, Belgium;
- Laboratory of Functional Neurophysiology and Pathology, Research Unit, UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, 1068 Tunis, Tunisia
| | - Marc Léonetti
- Université de. Grenoble Alpes, CNRS, LRP, 38000 Grenoble, France;
| | - Hanna Kmita
- Department of Bioenergetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland;
| | - Fabrice Homblé
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Boulevard du Triomphe CP 206/2, B-1050 Bruxelles, Belgium;
- Correspondence: ; Tel.: +32-2-650-5383
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34
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Abstract
The evolution of the eukaryotic cell from the primal endosymbiotic event involved a complex series of adaptations driven primarily by energy optimization. Transfer of genes from endosymbiont to host and concomitant expansion (by infolding) of the endosymbiont's chemiosmotic membrane greatly increased output of adenosine triphosphate (ATP) and placed selective pressure on the membrane at the host-endosymbiont interface to sustain the energy advantage. It is hypothesized that critical functions at this interface (metabolite exchange, polypeptide import, barrier integrity to proteins and DNA) were managed by a precursor β-barrel protein ("pβB") from which the voltage-dependent anion-selective channel (VDAC) descended. VDAC's role as hub for disparate and increasingly complex processes suggests an adaptability that likely springs from a feature inherited from pβB, retained because of important advantages conferred. It is proposed that this property is the remarkable structural flexibility evidenced in VDAC's gating mechanism, a possible origin of which is discussed.
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Affiliation(s)
- Carmen A Mannella
- Department of Physiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
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35
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Hwang HY, Shim JS, Kim D, Kwon HJ. Antidepressant drug sertraline modulates AMPK-MTOR signaling-mediated autophagy via targeting mitochondrial VDAC1 protein. Autophagy 2020; 17:2783-2799. [PMID: 33124469 PMCID: PMC8525979 DOI: 10.1080/15548627.2020.1841953] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Macroautophagy/autophagy (hereafter autophagy), the process of mass degradation of unnecessary elements within the cell, is often dysregulated in many diseases such as cancer, atherosclerosis, and neurodegenerative diseases. Hence, autophagy modulating agents have a great potential to be therapeutic agents for the autophagy-related diseases. Here we report that an anti-depressant drug sertraline (Sert) is an autophagy-inducing agent. Mechanistically, Sert potentially binds to and antagonizes the mitochondrial VDAC1 (voltage dependent anion channel 1), resulting in reduced cellular ATP (adenosine triphosphate) level, activation of AMP-activated protein kinase (AMPK) and inhibition of its downstream, MTOR (mechanistic target of rapamycin kinase)-RPS6KB1 (ribosomal protein S6 kinase B1) signaling pathway. Cells lacking VDAC1 expression completely abrogate the modulatory effect of Sert on AMPK-MTOR pathway and autophagy-inducing activity. We further show that Sert suppresses tauopathy by promoting the autophagic degradation of MAPT (microtubule associated protein tau) protein via inducing autophagy. Our study demonstrates the potential of Sert as a novel small molecule autophagy-inducing agent and provides a new drug candidate to treat autophagy related diseases by targeting VDAC1. Abbreviations: AMP: adenosine monophosphate; AMPK: AMP-activated protein kinase; ATP: adenosine triphosphate; Baf: bafilomycin A1; BiFC: biomolecular fluorescence complementation; CAMKK2/CAMKKB: calcium/calmodulin dependent protein kinase kinase 2; CC: compound C; DARTS: drug affinity responsive target stability; HUVECs: human umbilical vein endothelial cells; Inda: indatraline; STK11/LKB1: serine/threonine kinase 11; MAPT: microtubule associated protein tau; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; 3-MA: 3-methyladenine; MEFs: mouse embryonic fibroblasts; MTOR: mechanistic target of rapamycin kinase; PI3K: phosphoinositide 3-kinase; Rapa: rapamycin; Sert: sertraline; RPS6KB1: ribosomal protein S6 kinase B1; SQSTM1/p62: sequestosome 1; SLC6A4/SERT1: solute carrier family 6 member 4; TFEB: transcription factor EB; VDAC1: voltage dependent anion channel 1; WT: wild-type; WM: wortmannin.
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Affiliation(s)
- Hui-Yun Hwang
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Joong Sup Shim
- Faculty of Health Sciences, University of Macau, Taipa, China
| | - Dasol Kim
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Ho Jeong Kwon
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
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36
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Selective knockdown of hexokinase 2 in rods leads to age-related photoreceptor degeneration and retinal metabolic remodeling. Cell Death Dis 2020; 11:885. [PMID: 33082308 PMCID: PMC7576789 DOI: 10.1038/s41419-020-03103-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022]
Abstract
Photoreceptors, the primary site of phototransduction in the retina, require energy and metabolites to constantly renew their outer segments. They preferentially consume most glucose through aerobic glycolysis despite possessing abundant mitochondria and enzymes for oxidative phosphorylation (OXPHOS). Exactly how photoreceptors balance aerobic glycolysis and mitochondrial OXPHOS to regulate their survival is still unclear. We crossed rhodopsin-Cre mice with hexokinase 2 (HK2)-floxed mice to study the effect of knocking down HK2, the first rate-limiting enzyme in glycolysis, on retinal health and metabolic remodeling. Immunohistochemistry and Western blots were performed to study changes in photoreceptor-specific proteins and key enzymes in glycolysis and the tricarboxylic acid (TCA) cycle. Changes in retinal structure and function were studied by optical coherence tomography and electroretinography. Mass spectrometry was performed to profile changes in 13C-glucose-derived metabolites in glycolysis and the TCA cycle. We found that knocking down HK2 in rods led to age-related photoreceptor degeneration, evidenced by reduced expression of photoreceptor-specific proteins, age-related reductions of the outer nuclear layer, photoreceptor inner and outer segments and impaired electroretinographic responses. Loss of HK2 in rods led to upregulation of HK1, phosphorylation of pyruvate kinase muscle isozyme 2, mitochondrial stress proteins and enzymes in the TCA cycle. Mass spectrometry found that the deletion of HK2 in rods resulted in accumulation of 13C-glucose along with decreased pyruvate and increased metabolites in the TCA cycle. Our data suggest that HK2-mediated aerobic glycolysis is indispensable for the maintenance of photoreceptor structure and function and that long-term inhibition of glycolysis leads to photoreceptor degeneration.
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37
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Malik C, Ghosh S. Regulation of Single-Channel Conductance of Voltage-Dependent Anion Channel by Mercuric Chloride in a Planar Lipid Bilayer. J Membr Biol 2020; 253:357-371. [PMID: 32748041 DOI: 10.1007/s00232-020-00134-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/24/2020] [Indexed: 11/26/2022]
Abstract
The existence of mercury in various forms, e.g., elemental, organic, and inorganic has been known for decades. In any of these forms, it is poisonous to metabolism. In this, an investigation about the effect of the inorganic form of mercury, i.e., mercuric chloride (HgCl2) to the mitochondrial voltage-dependent anion channel (VDAC), has been done after isolation from the cardiac and brain tissues of Wistar rats. In vitro electrophysiology experiments were performed in Cardiolipin planar lipid bilayer membrane (BLM) to study the change in the conductance, selectivity, and gating charge of VDAC post HgCl2 treatment. A reduction in mean conductance of VDAC from 4.3 ± 0.18 to 1.66 ± 0.11 nS was observed. Further, the Gating charge calculated before (± 3.5) and after HgCl2 treatment (± 2.3) showed significant difference. Later, VDAC's behavior was studied at different concentrations of HgCl2 ranging from 0.1 μM to 1 mM. The Inhibitory concentration (IC50) was calculated from the linear regression plot. The IC50 was found to be 488.1 μM. In the asymmetrical HgCl2 (5:1), a permeability ratio of cation to anion was found to be 4.2. It is interpreted that VDAC functioning is affected due to the application of 4 mM HgCl2 and a reduction in the conductance, gating charge, and permeability of VDAC was detected. The results provide clues to HgCl2-induced toxicity mediated through VDAC in the Cardiolipin BLM.
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Affiliation(s)
- Chetan Malik
- Department of Biophysics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Subhendu Ghosh
- Department of Biophysics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
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38
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Rostovtseva TK, Queralt-Martín M, Rosencrans WM, Bezrukov SM. Targeting the Multiple Physiologic Roles of VDAC With Steroids and Hydrophobic Drugs. Front Physiol 2020; 11:446. [PMID: 32457654 PMCID: PMC7221028 DOI: 10.3389/fphys.2020.00446] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/09/2020] [Indexed: 12/12/2022] Open
Abstract
There is accumulating evidence that endogenous steroids and non-polar drugs are involved in the regulation of mitochondrial physiology. Many of these hydrophobic compounds interact with the Voltage Dependent Anion Channel (VDAC). This major metabolite channel in the mitochondrial outer membrane (MOM) regulates the exchange of ions and water-soluble metabolites, such as ATP and ADP, across the MOM, thus governing mitochondrial respiration. Proteomics and biochemical approaches together with molecular dynamics simulations have identified an impressively large number of non-polar compounds, including endogenous, able to bind to VDAC. These findings have sparked speculation that both natural steroids and synthetic hydrophobic drugs regulate mitochondrial physiology by directly affecting VDAC ion channel properties and modulating its metabolite permeability. Here we evaluate recent studies investigating the effect of identified VDAC-binding natural steroids and non-polar drugs on VDAC channel functioning. We argue that while many compounds are found to bind to the VDAC protein, they do not necessarily affect its channel functions in vitro. However, they may modify other aspects of VDAC physiology such as interaction with its cytosolic partner proteins or complex formation with other mitochondrial membrane proteins, thus altering mitochondrial function.
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Affiliation(s)
- Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - William M Rosencrans
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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39
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Calabrò E, Magazù S, Currò M, Ientile R. The inverse relation between mitochondrial transmembrane potential and proteins α-helix in neuronal-like cells under static magnetic field and the role of VDAC. Electromagn Biol Med 2020; 39:176-182. [PMID: 32149540 DOI: 10.1080/15368378.2020.1737808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In this study, a correlation between cell channel α-helices displacement and the mitochondrial transmembrane potential after exposure of 3, 7, 15 and 24 h of neuronal-like cells to a uniform magnetic field at the intensity of 2 mT was shown. Fourier Transform Infrared (FTIR) Spectroscopy and fluorescence techniques were used to analyze the secondary structure of protein content and mitochondrial transmembrane potential, respectively. The main result of this study was represented by a significant inverse relation between the mitochondrial transmembrane potential and the intensity of the Amide I band that can be associated with time exposure. Given that mitochondrial transmembrane potential should be related to the gating state of voltage-dependent anion channel (VDAC) in mitochondrial membrane, this result could have a relevant role in medicine. Indeed, VDAC's irregular behavior can be associated with several varieties of mitochondria-associated pathologies and various forms of cancer and neurodegeneration.
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Affiliation(s)
- Emanuele Calabrò
- Department of Mathematical and Informatics Sciences, Physical Sciences and Earth Sciences of Messina University, Messina, Italy
| | - Salvatore Magazù
- Department of Mathematical and Informatics Sciences, Physical Sciences and Earth Sciences of Messina University, Messina, Italy.,Department of Biochemical and Dental Sciences and Morphological and Functional Image, University of Messina, Messina, Italy.,Le Studium, Loire Valley Institute for Advanced Studies, Orléans & Tours, France.,Centre de Biophysique Moleculaire (CBM), rue Charles Sandron, Laboratoire Interfaces, Confinement, Materiaux et Nanostructures (ICMN) - UMR 7374 CNRS, Université d'Orleans, Orleans, France.,INDAM - Gruppo Nazionale per la Fisica Matematica - GNFM, Istituto Nazionale di Alta Matematica "F. Severi, Rome, Italy
| | - Monica Currò
- Department of Biochemical and Dental Sciences and Morphological and Functional Image, University of Messina, Messina, Italy
| | - Riccardo Ientile
- Department of Biochemical and Dental Sciences and Morphological and Functional Image, University of Messina, Messina, Italy
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40
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Molina BG, Lopes-Rodrigues M, Estrany F, Michaux C, Perpète EA, Armelin E, Alemán C. Free-standing flexible and biomimetic hybrid membranes for ions and ATP transport. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.117931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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41
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Böhm R, Amodeo GF, Murlidaran S, Chavali S, Wagner G, Winterhalter M, Brannigan G, Hiller S. The Structural Basis for Low Conductance in the Membrane Protein VDAC upon β-NADH Binding and Voltage Gating. Structure 2020; 28:206-214.e4. [PMID: 31862297 PMCID: PMC8353649 DOI: 10.1016/j.str.2019.11.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/27/2019] [Accepted: 11/26/2019] [Indexed: 11/26/2022]
Abstract
The voltage-dependent anion channel (VDAC) forms the primary diffusion pore of the outer mitochondrial membrane. In its apo form, VDAC adopts an open conformation with high conductance. States of lower conductance can be induced by ligand binding or the application of voltage. Here, we clarify at the atomic level how β-NADH binding leads to a low-conductance state and characterize the role of the VDAC N-terminal helix in voltage gating. A high-resolution NMR structure of human VDAC-1 with bound NADH, combined with molecular dynamics simulation show that β-NADH binding reduces the pore conductance sterically without triggering a structural change. Electrophysiology recordings of crosslinked protein variants and NMR relaxation experiments probing different time scales show that increased helix dynamics is present in the open state and that motions of the N-terminal helices are involved in the VDAC voltage gating mechanism.
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Affiliation(s)
- Raphael Böhm
- Biozentrum, University of Basel, Basel 4056, Switzerland
| | | | - Sruthi Murlidaran
- Center for Computational Biology, Rutgers University, Camden, NJ 08102, USA
| | - Shashank Chavali
- Department of Biology, Rutgers University, Camden, NJ 08201, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Grace Brannigan
- Center for Computational Biology, Rutgers University, Camden, NJ 08102, USA; Department of Physics, Center for Computational and Integrative Biology, Rutgers University, Camden, NJ 08201, USA
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42
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Xie D, Audi SH, Dash RK. A size-modified poisson-boltzmann ion channel model in a solvent of multiple ionic species: Application to voltage-dependent anion channel. J Comput Chem 2020; 41:218-230. [PMID: 31845398 PMCID: PMC8189662 DOI: 10.1002/jcc.26091] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/30/2019] [Accepted: 09/24/2019] [Indexed: 12/30/2022]
Abstract
We present a new size-modified Poisson-Boltzmann ion channel (SMPBIC) model and use it to calculate the electrostatic potential, ionic concentrations, and electrostatic solvation free energy for a voltage-dependent anion channel (VDAC) on a biological membrane in a solution mixture of multiple ionic species. In particular, the new SMPBIC model adopts a membrane surface charge density and a natural Neumann boundary condition to reflect the charge effect of the membrane on the electrostatics of VDAC. To avoid the singularity difficulties caused by the atomic charges of VDAC, the new SMPBIC model is split into three submodels such that the solution of one of the submodels is obtained analytically and contains all the singularity points of the SMPBIC model. The other two submodels are then solved numerically much more efficiently than the original SMPBIC model. As an application of this SMPBIC submodel partitioning scheme, we derive a new formula for computing the electrostatic solvation free energy. Numerical results for a human VDAC isoform 1 (hVDAC1) in three different salt solutions, each with up to five different ionic species, confirm the significant effects of membrane surface charges on both the electrostatics and ionic concentrations. The results also show that the new SMPBIC model can describe well the anion selectivity property of hVDAC1, and that the new electrostatic solvation free energy formula can significantly improve the accuracy of the currently used formula. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Dexuan Xie
- Department of Mathematical Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, 53201
| | - Said H Audi
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin, 53233
| | - Ranjan K Dash
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226
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43
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Müller WE, Schröder HC, Wang X. Inorganic Polyphosphates As Storage for and Generator of Metabolic Energy in the Extracellular Matrix. Chem Rev 2019; 119:12337-12374. [PMID: 31738523 PMCID: PMC6935868 DOI: 10.1021/acs.chemrev.9b00460] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Indexed: 12/14/2022]
Abstract
Inorganic polyphosphates (polyP) consist of linear chains of orthophosphate residues, linked by high-energy phosphoanhydride bonds. They are evolutionarily old biopolymers that are present from bacteria to man. No other molecule concentrates as much (bio)chemically usable energy as polyP. However, the function and metabolism of this long-neglected polymer are scarcely known, especially in higher eukaryotes. In recent years, interest in polyP experienced a renaissance, beginning with the discovery of polyP as phosphate source in bone mineralization. Later, two discoveries placed polyP into the focus of regenerative medicine applications. First, polyP shows morphogenetic activity, i.e., induces cell differentiation via gene induction, and, second, acts as an energy storage and donor in the extracellular space. Studies on acidocalcisomes and mitochondria provided first insights into the enzymatic basis of eukaryotic polyP formation. In addition, a concerted action of alkaline phosphatase and adenylate kinase proved crucial for ADP/ATP generation from polyP. PolyP added extracellularly to mammalian cells resulted in a 3-fold increase of ATP. The importance and mechanism of this phosphotransfer reaction for energy-consuming processes in the extracellular matrix are discussed. This review aims to give a critical overview about the formation and function of this unique polymer that is capable of storing (bio)chemically useful energy.
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Affiliation(s)
- Werner E.G. Müller
- ERC Advanced Investigator
Grant Research
Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - Heinz C. Schröder
- ERC Advanced Investigator
Grant Research
Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator
Grant Research
Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
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44
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Lopes-Rodrigues M, Matagne A, Zanuy D, Alemán C, Perpète EA, Michaux C. Structural and functional characterization of Solanum tuberosum VDAC36. Proteins 2019; 88:729-739. [PMID: 31833115 DOI: 10.1002/prot.25861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/26/2019] [Accepted: 12/06/2019] [Indexed: 11/05/2022]
Abstract
As it forms water-filled channel in the mitochondria outer membrane and diffuses essential metabolites such as NADH and ATP, the voltage-dependent anion channel (VDAC) protein family plays a central role in all eukaryotic cells. In comparison with their mammalian homologues, little is known about the structural and functional properties of plant VDACs. In the present contribution, one of the two VDACs isoforms of Solanum tuberosum, stVDAC36, has been successfully overexpressed and refolded by an in-house method, as demonstrated by the information on its secondary and tertiary structure gathered from circular dichroism and intrinsic fluorescence. Cross-linking and molecular modeling studies have evidenced the presence of dimers and tetramers, and they suggest the formation of an intermolecular disulfide bond between two stVDAC36 monomers. The pore-forming activity was also assessed by liposome swelling assays, indicating a typical pore diameter between 2.0 and 2.7 nm. Finally, insights about the ATP binding inside the pore are given by docking studies and electrostatic calculations.
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Affiliation(s)
- Maximilien Lopes-Rodrigues
- Laboratoire de Chimie Physique des Biomolécules, Unité de Chimie Physique Théorique et Structurale (UCPTS), University of Namur, Namur, Belgium.,Namur Institute of Structured Matter, University of Namur, Namur, Belgium.,Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya, C/Eduard Maristany, Barcelona, Spain.,Barcelona Research Center for Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Eduard Maristany, Barcelona, Spain
| | - André Matagne
- Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines (CIP), Université de Liège, Liège, Belgium
| | - David Zanuy
- Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya, C/Eduard Maristany, Barcelona, Spain
| | - Carlos Alemán
- Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya, C/Eduard Maristany, Barcelona, Spain.,Barcelona Research Center for Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Eduard Maristany, Barcelona, Spain
| | - Eric A Perpète
- Laboratoire de Chimie Physique des Biomolécules, Unité de Chimie Physique Théorique et Structurale (UCPTS), University of Namur, Namur, Belgium.,Namur Institute of Structured Matter, University of Namur, Namur, Belgium.,Namur Research Institute for Life Sciences, University of Namur, Namur, Belgium
| | - Catherine Michaux
- Laboratoire de Chimie Physique des Biomolécules, Unité de Chimie Physique Théorique et Structurale (UCPTS), University of Namur, Namur, Belgium.,Namur Institute of Structured Matter, University of Namur, Namur, Belgium.,Institute of Life-Earth-Environment, University of Namur, Namur, Belgium
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45
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Eddy MT, Yu TY, Wagner G, Griffin RG. Structural characterization of the human membrane protein VDAC2 in lipid bilayers by MAS NMR. JOURNAL OF BIOMOLECULAR NMR 2019; 73:451-460. [PMID: 31407201 PMCID: PMC6819253 DOI: 10.1007/s10858-019-00242-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 03/19/2019] [Indexed: 05/25/2023]
Abstract
The second isoform of the human voltage dependent anion channel (VDAC2) is a mitochondrial porin that translocates calcium and other metabolites across the outer mitochondrial membrane. VDAC2 has been implicated in cardioprotection and plays a critical role in a unique apoptotic pathway in tumor cells. Despite its medical importance, there have been few biophysical studies of VDAC2 in large part due to the difficulty of obtaining homogeneous preparations of the protein for spectroscopic characterization. Here we present high resolution magic angle spinning nuclear magnetic resonance (NMR) data obtained from homogeneous preparation of human VDAC2 in 2D crystalline lipid bilayers. The excellent resolution in the spectra permit several sequence-specific assignments of the signals for a large portion of the VDAC2 N-terminus and several other residues in two- and three-dimensional heteronuclear correlation experiments. The first 12 residues appear to be dynamic, are not visible in cross polarization experiments, and they are not sufficiently mobile on very fast timescales to be visible in 13C INEPT experiments. A comparison of the NMR spectra of VDAC2 and VDAC1 obtained from highly similar preparations demonstrates that the spectral quality, line shapes and peak dispersion exhibited by the two proteins are nearly identical. This suggests an overall similar dynamic behavior and conformational homogeneity, which is in contrast to two earlier reports that suggested an inherent conformational heterogeneity of VDAC2 in membranes. The current data suggest that the sample preparation and spectroscopic methods are likely applicable to studying other human membrane porins, including human VDAC3, which has not yet been structurally characterized.
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Affiliation(s)
- Matthew T Eddy
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Departments of Chemistry, University of Florida, Gainesville, FL, 32611, USA
| | - Tsyr-Yan Yu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan, Republic of China
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Robert G Griffin
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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46
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Respiration of permeabilized cardiomyocytes from mice: no sex differences, but substrate-dependent changes in the apparent ADP-affinity. Sci Rep 2019; 9:12592. [PMID: 31467353 PMCID: PMC6715638 DOI: 10.1038/s41598-019-48964-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 08/12/2019] [Indexed: 11/17/2022] Open
Abstract
Sex differences in cardiac physiology are getting increased attention. This study assessed whether isolated, permeabilized cardiomyocytes from male and female C57BL/6 mice differ in terms of their respiration with multiple substrates and overall intracellular diffusion restriction estimated by the apparent ADP-affinity of respiration. Using respirometry, we recorded 1) the activities of respiratory complexes I, II and IV, 2) the respiration rate with substrates fuelling either complex I, II, or I + II, and 3) the apparent ADP-affinity with substrates fuelling complex I and I + II. The respiration rates were normalized to protein content and citrate synthase (CS) activity. We found no sex differences in CS activity (a marker of mitochondrial content) normalized to protein content or in any of the respiration measurements. This suggests that cardiomyocytes from male and female mice do not differ in terms of mitochondrial respiratory capacity and apparent ADP-affinity. Pyruvate modestly lowered the respiration rate, when added to succinate, glutamate and malate. This may be explained by intramitochondrial compartmentalization caused by the formation of supercomplexes and their association with specific dehydrogenases. To our knowledge, we show for the first time that the apparent ADP-affinity was substrate-dependent. This suggests that substrates may change or regulate intracellular barriers in cardiomyocytes.
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47
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Rabbani N, Thornalley PJ. Hexokinase-2 Glycolytic Overload in Diabetes and Ischemia-Reperfusion Injury. Trends Endocrinol Metab 2019; 30:419-431. [PMID: 31221272 DOI: 10.1016/j.tem.2019.04.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/21/2019] [Accepted: 04/25/2019] [Indexed: 01/12/2023]
Abstract
Hexokinase-2 (HK2) was recently found to produce increased metabolic flux through glycolysis in hyperglycemia without concurrent transcriptional or other functional regulation. Rather, stabilization to proteolysis by increased glucose substrate binding produced unscheduled increased glucose metabolism in response to high cytosolic glucose concentration. This produces abnormal increases in glycolytic intermediates or glycolytic overload, driving cell dysfunction and vulnerability to the damaging effects of hyperglycemia in diabetes, explaining tissue-specific pathogenesis. Glycolytic overload is also activated in ischemia-reperfusion injury and cell senescence. A further key feature is HK2 displacement from mitochondria by increased glucose-6-phosphate concentration, inducing mitochondrial dysfunction and oxidative stress. This pathogenic mechanism suggested new targets for therapeutics development that gave promising outcomes in initial clinical evaluation.
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Affiliation(s)
- Naila Rabbani
- Clinical Sciences Research Laboratories, Warwick Medical School, University of Warwick, University Hospital, Coventry CV2 2DX, UK
| | - Paul J Thornalley
- Diabetes Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 34110, Doha, Qatar.
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48
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Inhibition by fluoxetine of LH-stimulated cyclic AMP synthesis in tumor Leydig cells partly involves AMPK activation. PLoS One 2019; 14:e0217519. [PMID: 31163038 PMCID: PMC6548379 DOI: 10.1371/journal.pone.0217519] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/13/2019] [Indexed: 12/21/2022] Open
Abstract
Fluoxetine (FLX), a widely used antidepressant primarily acting as a selective serotonin reuptake inhibitor (SSRI), has been shown to exhibit other mechanisms of action in various cell types. Consequently, it might have unexpected adverse effects not related to its intended use, possibly in the endocrine regulation of reproduction. We show in the present report that after a 1-hour preincubation of MLTC-1 Leydig cells with FLX, the intracellular cyclic adenosine monophosphate (cAMP) responses to Luteinizing Hormone (LH) and forskolin (FSK) are reduced through AMPK-dependent and -independent pathways respectively. FLX at low concentrations (12.5μM and 25μM) induced this inhibition without triggering AMPK phosphorylation, while higher FLX concentrations (50μM and 100μM) induced AMPK phosphorylation and lowered ATP concentration similarly to Metformin. Pretreatment with the specific AMPK inhibitor Compound C (CpdC), significantly diminished the inhibition of cAMP synthesis caused by high concentration of FLX. Moreover, as expected FLX also caused a decline of steroidogenesis which is under the control of cAMP. Taken together, these findings demonstrate that the inhibition of cAMP synthesis by FLX is dose-dependent and occurs in MLTC-1 cells through two mechanisms, AMPK-independent and AMPK-dependent, at low and high concentrations, respectively. FLX also inhibited hormone-induced steroidogenesis in MLTC-1 cells and mouse testicular Leydig cells, suggesting similar mechanisms in both cell types.
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49
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Warnez‐Soulie J, Macia M, Lac S, Pecchi E, Bernard M, Bendahan D, Bartoli M, Carrier A, Giannesini B. Tumor protein 53-induced nuclear protein 1 deficiency alters mouse gastrocnemius muscle function and bioenergetics in vivo. Physiol Rep 2019; 7:e14055. [PMID: 31124296 PMCID: PMC6533175 DOI: 10.14814/phy2.14055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 03/14/2019] [Indexed: 12/06/2022] Open
Abstract
Tumor protein 53-induced nuclear protein 1 (TP53INP1) deficiency leads to oxidative stress-associated obesity and insulin resistance. Although skeletal muscle has a predominant role in the development of metabolic syndrome, the bioenergetics and functional consequences of TP53INP1 deficiency upon this tissue remain undocumented. To clarify this issue, gastrocnemius muscle mechanical performance, energy metabolism, and anatomy were investigated in TP53INP1-deficient and wild-type mice using a multidisciplinary approach implementing noninvasive multimodal-NMR techniques. TP53INP1 deficiency increased body adiposity but did not affect cytosolic oxidative stress, lipid content, and mitochondrial pool and capacity in myocyte. During a fatiguing bout of exercise, the in vivo oxidative ATP synthesis capacity was dramatically reduced in TP53INP1-deficient mice despite ADP level (the main in vivo stimulator of mitochondrial respiration) did not differ between both genotypes. Moreover, TP53INP1 deficiency did not alter fatigue resistance but paradoxically increased the contractile force, whereas there were no differences for muscle fiber-type distribution and calcium homeostasis between both genotypes. In addition, muscle proton efflux was decreased in TP53INP1-deficient mice, thereby indicating a reduced blood supply. In conclusion, TP53INP1 plays a role in muscle function and bioenergetics through oxidative capacity impairment possibly as the consequence of abnormal mitochondrial respiration regulation and/or defective blood supply.
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Affiliation(s)
| | | | - Sophie Lac
- Aix Marseille Univ, CNRS, INSERM, Institut Paoli‐Calmettes, CRCMMarseilleFrance
| | | | | | | | | | - Alice Carrier
- Aix Marseille Univ, CNRS, INSERM, Institut Paoli‐Calmettes, CRCMMarseilleFrance
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50
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Succinylation-dependent mitochondrial translocation of PKM2 promotes cell survival in response to nutritional stress. Cell Death Dis 2019; 10:170. [PMID: 30787272 PMCID: PMC6382874 DOI: 10.1038/s41419-018-1271-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/22/2018] [Accepted: 11/28/2018] [Indexed: 01/15/2023]
Abstract
Tumor growth and progression is characteristically associated with the synergistic effects of uncontrolled cellular proliferation and cell survival under stress. Pyruvate kinase M2 (PKM2) contributes to both of these effects. However, the specific mechanism by which PKM2 promotes uncontrolled proliferation or cell survival under stress in different nutritional environments is unclear. We show that succinylation mediated mitochondrial translocation of PKM2 under glucose starvation plays a role in switching the cellular machinery from proliferation to cell survival mode and vice versa. Mitochondrial PKM2 inhibits ubiquitination-mediated degradation of voltage-dependent anion channel 3 (VDAC3) and increases mitochondrial permeability to generate more ATP for cell survival under nutritional depletion. We found there is a positive correlation of upregulation of mitochondrial PKM2 and upregulation of VDAC3 in human colon cancer. This shows the mechanisms identified in this study in fact play a role in neoplastic biology. We therefore developed a small molecule designated compound 8 that blocks mitochondrial translocation of PKM2 and inhibits tumor development. Our data suggest that blocking PKM2 mitochondrial function with a small molecule inhibitor has potential for cancer treatment.
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