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Krieger MR, Abrahamian M, He KL, Atamdede S, Hakimjavadi H, Momcilovic M, Ostrow D, Maggo SD, Tsang YP, Gai X, Chanfreau GF, Shackelford DB, Teitell MA, Koehler CM. Trafficking of mitochondrial double-stranded RNA from mitochondria to the cytosol. Life Sci Alliance 2024; 7:e202302396. [PMID: 38955468 PMCID: PMC11220484 DOI: 10.26508/lsa.202302396] [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: 09/26/2023] [Revised: 06/25/2024] [Accepted: 06/25/2024] [Indexed: 07/04/2024] Open
Abstract
In addition to mitochondrial DNA, mitochondrial double-stranded RNA (mtdsRNA) is exported from mitochondria. However, specific channels for RNA transport have not been demonstrated. Here, we begin to characterize channel candidates for mtdsRNA export from the mitochondrial matrix to the cytosol. Down-regulation of SUV3 resulted in the accumulation of mtdsRNAs in the matrix, whereas down-regulation of PNPase resulted in the export of mtdsRNAs to the cytosol. Targeting experiments show that PNPase functions in both the intermembrane space and matrix. Strand-specific sequencing of the double-stranded RNA confirms the mitochondrial origin. Inhibiting or down-regulating outer membrane proteins VDAC1/2 and BAK/BAX or inner membrane proteins PHB1/2 strongly attenuated the export of mtdsRNAs to the cytosol. The cytosolic mtdsRNAs subsequently localized to large granules containing the stress protein TIA-1 and activated the type 1 interferon stress response pathway. Abundant mtdsRNAs were detected in a subset of non-small-cell lung cancer cell lines that were glycolytic, indicating relevance in cancer biology. Thus, we propose that mtdsRNA is a new damage-associated molecular pattern that is exported from mitochondria in a regulated manner.
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Affiliation(s)
- Matthew R Krieger
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
| | | | - Kevin L He
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
| | - Sean Atamdede
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
| | | | - Milica Momcilovic
- Pulmonary and Critical Care Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
| | - Dejerianne Ostrow
- Department of Pathology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Simran Ds Maggo
- Department of Pathology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Yik Pui Tsang
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
| | - Xiaowu Gai
- Department of Pathology, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
- Molecular Biology Institute, UCLA, Los Angeles, CA, USA
| | - David B Shackelford
- Pulmonary and Critical Care Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
| | - Michael A Teitell
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
- Molecular Biology Institute, UCLA, Los Angeles, CA, USA
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, CA, USA
- Broad Stem Cell Research Center, UCLA, Los Angeles, CA, USA
- NanoSystems Institute, UCLA, Los Angeles, CA, USA
| | - Carla M Koehler
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
- Molecular Biology Institute, UCLA, Los Angeles, CA, USA
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2
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Taylor AD, Hathaway QA, Kunovac A, Pinti MV, Newman MS, Cook CC, Cramer ER, Starcovic SA, Winters MT, Westemeier-Rice ES, Fink GK, Durr AJ, Rizwan S, Shepherd DL, Robart AR, Martinez I, Hollander JM. Mitochondrial sequencing identifies long noncoding RNA features that promote binding to PNPase. Am J Physiol Cell Physiol 2024; 327:C221-C236. [PMID: 38826135 DOI: 10.1152/ajpcell.00648.2023] [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: 11/27/2023] [Revised: 05/24/2024] [Accepted: 05/24/2024] [Indexed: 06/04/2024]
Abstract
Extranuclear localization of long noncoding RNAs (lncRNAs) is poorly understood. Based on machine learning evaluations, we propose a lncRNA-mitochondrial interaction pathway where polynucleotide phosphorylase (PNPase), through domains that provide specificity for primary sequence and secondary structure, binds nuclear-encoded lncRNAs to facilitate mitochondrial import. Using FVB/NJ mouse and human cardiac tissues, RNA from isolated subcellular compartments (cytoplasmic and mitochondrial) and cross-linked immunoprecipitate (CLIP) with PNPase within the mitochondrion were sequenced on the Illumina HiSeq and MiSeq, respectively. lncRNA sequence and structure were evaluated through supervised [classification and regression trees (CART) and support vector machines (SVM)] machine learning algorithms. In HL-1 cells, quantitative PCR of PNPase CLIP knockout mutants (KH and S1) was performed. In vitro fluorescence assays assessed PNPase RNA binding capacity and verified with PNPase CLIP. One hundred twelve (mouse) and 1,548 (human) lncRNAs were identified in the mitochondrion with Malat1 being the most abundant. Most noncoding RNAs binding PNPase were lncRNAs, including Malat1. lncRNA fragments bound to PNPase compared against randomly generated sequences of similar length showed stratification with SVM and CART algorithms. The lncRNAs bound to PNPase were used to create a criterion for binding, with experimental validation revealing increased binding affinity of RNA designed to bind PNPase compared to control RNA. The binding of lncRNAs to PNPase was decreased through the knockout of RNA binding domains KH and S1. In conclusion, sequence and secondary structural features identified by machine learning enhance the likelihood of nuclear-encoded lncRNAs binding to PNPase and undergoing import into the mitochondrion.NEW & NOTEWORTHY Long noncoding RNAs (lncRNAs) are relatively novel RNAs with increasingly prominent roles in regulating genetic expression, mainly in the nucleus but more recently in regions such as the mitochondrion. This study explores how lncRNAs interact with polynucleotide phosphorylase (PNPase), a protein that regulates RNA import into the mitochondrion. Machine learning identified several RNA structural features that improved lncRNA binding to PNPase, which may be useful in targeting RNA therapeutics to the mitochondrion.
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Affiliation(s)
- Andrew D Taylor
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Mitochondria, Metabolism, and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Quincy A Hathaway
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Heart and Vascular Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Medical Education, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Amina Kunovac
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Mitochondria, Metabolism, and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Mark V Pinti
- Mitochondria, Metabolism, and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- West Virginia University School of Pharmacy, Morgantown, West Virginia, United States
| | - Mackenzie S Newman
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Chris C Cook
- Cardiovascular and Thoracic Surgery, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Evan R Cramer
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Sarah A Starcovic
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Michael T Winters
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University Cancer Institute, School of Medicine, Morgantown, West Virginia, United States
| | - Emily S Westemeier-Rice
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University Cancer Institute, School of Medicine, Morgantown, West Virginia, United States
| | - Garrett K Fink
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Andrya J Durr
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Mitochondria, Metabolism, and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Saira Rizwan
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Mitochondria, Metabolism, and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Danielle L Shepherd
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Mitochondria, Metabolism, and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Aaron R Robart
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown, West Virginia, United States
| | - Ivan Martinez
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University Cancer Institute, School of Medicine, Morgantown, West Virginia, United States
| | - John M Hollander
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Mitochondria, Metabolism, and Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, West Virginia, United States
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3
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Trease AJ, Totusek S, Lichter EZ, Stauch KL, Fox HS. Mitochondrial DNA Instability Supersedes Parkin Mutations in Driving Mitochondrial Proteomic Alterations and Functional Deficits in Polg Mutator Mice. Int J Mol Sci 2024; 25:6441. [PMID: 38928146 PMCID: PMC11203920 DOI: 10.3390/ijms25126441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/30/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Mitochondrial quality control is essential in mitochondrial function. To examine the importance of Parkin-dependent mechanisms in mitochondrial quality control, we assessed the impact of modulating Parkin on proteome flux and mitochondrial function in a context of reduced mtDNA fidelity. To accomplish this, we crossed either the Parkin knockout mouse or ParkinW402A knock-in mouse lines to the Polg mitochondrial mutator line to generate homozygous double mutants. In vivo longitudinal isotopic metabolic labeling was followed by isolation of liver mitochondria and synaptic terminals from the brain, which are rich in mitochondria. Mass spectrometry and bioenergetics analysis were assessed. We demonstrate that slower mitochondrial protein turnover is associated with loss of mtDNA fidelity in liver mitochondria but not synaptic terminals, and bioenergetic function in both tissues is impaired. Pathway analysis revealed loss of mtDNA fidelity is associated with disturbances of key metabolic pathways, consistent with its association with metabolic disorders and neurodegeneration. Furthermore, we find that loss of Parkin leads to exacerbation of Polg-driven proteomic consequences, though it may be bioenergetically protective in tissues exhibiting rapid mitochondrial turnover. Finally, we provide evidence that, surprisingly, dis-autoinhibition of Parkin (ParkinW402A) functionally resembles Parkin knockout and fails to rescue deleterious Polg-driven effects. Our study accomplishes three main outcomes: (1) it supports recent studies suggesting that Parkin dependence is low in response to an increased mtDNA mutational load, (2) it provides evidence of a potential protective role of Parkin insufficiency, and (3) it draws into question the therapeutic attractiveness of enhancing Parkin function.
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Affiliation(s)
- Andrew J. Trease
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (A.J.T.); (S.T.); (K.L.S.)
| | - Steven Totusek
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (A.J.T.); (S.T.); (K.L.S.)
| | - Eliezer Z. Lichter
- Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA;
| | - Kelly L. Stauch
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (A.J.T.); (S.T.); (K.L.S.)
| | - Howard S. Fox
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (A.J.T.); (S.T.); (K.L.S.)
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4
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Falchi FA, Forti F, Carnelli C, Genco A, Pizzoccheri R, Manzari C, Pavesi G, Briani F. Human PNPase causes RNA stabilization and accumulation of R-loops in the Escherichia coli model system. Sci Rep 2023; 13:11771. [PMID: 37479726 PMCID: PMC10362022 DOI: 10.1038/s41598-023-38924-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 07/17/2023] [Indexed: 07/23/2023] Open
Abstract
Polyribonucleotide phosphorylase (PNPase) is a phosphorolytic RNA exonuclease highly conserved throughout evolution. In Escherichia coli, PNPase controls complex phenotypic traits like biofilm formation and growth at low temperature. In human cells, PNPase is located in mitochondria, where it is implicated in the RNA import from the cytoplasm, the mitochondrial RNA degradation and the processing of R-loops, namely stable RNA-DNA hybrids displacing a DNA strand. In this work, we show that the human PNPase (hPNPase) expressed in E. coli causes oxidative stress, SOS response activation and R-loops accumulation. Hundreds of E. coli RNAs are stabilized in presence of hPNPase, whereas only few transcripts are destabilized. Moreover, phenotypic traits typical of E. coli strains lacking PNPase are strengthened in presence of the human enzyme. We discuss the hypothesis that hPNPase expressed in E. coli may bind, but not degrade, the RNA, in agreement with previous in vitro data showing that phosphate concentrations in the range of those found in the bacterial cytoplasm and, more relevant, in the mitochondria, inhibit its activity.
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Affiliation(s)
- Federica A Falchi
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Francesca Forti
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Cristina Carnelli
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Aurelia Genco
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Roberto Pizzoccheri
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Caterina Manzari
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari "Aldo Moro", 70121, Bari, Italy
| | - Giulio Pavesi
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy.
| | - Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy.
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5
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Hsu CG, Li W, Sowden M, Chávez CL, Berk BC. Pnpt1 mediates NLRP3 inflammasome activation by MAVS and metabolic reprogramming in macrophages. Cell Mol Immunol 2023; 20:131-142. [PMID: 36596874 PMCID: PMC9886977 DOI: 10.1038/s41423-022-00962-2] [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] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 11/13/2022] [Indexed: 01/05/2023] Open
Abstract
Polyribonucleotide nucleotidyltransferase 1 (Pnpt1) plays critical roles in mitochondrial homeostasis by controlling mitochondrial RNA (mt-RNA) processing, trafficking and degradation. Pnpt1 deficiency results in mitochondrial dysfunction that triggers a type I interferon response, suggesting a role in inflammation. However, the role of Pnpt1 in inflammasome activation remains largely unknown. In this study, we generated myeloid-specific Pnpt1-knockout mice and demonstrated that Pnpt1 depletion enhanced interleukin-1 beta (IL-1β) and interleukin-18 (IL-18) secretion in a mouse sepsis model. Using cultured peritoneal and bone marrow-derived macrophages, we demonstrated that Pnpt1 regulated NLRP3 inflammasome-dependent IL-1β release in response to lipopolysaccharide (LPS), followed by nigericin, ATP or poly (I:C) treatment. Pnpt1 deficiency in macrophages increased glycolysis after LPS administration and mt-reactive oxygen species (mt-ROS) after NLRP3 inflammasome activation. Pnpt1 activation of the inflammasome was dependent on increased glycolysis and the expression of mitochondrial antiviral-signaling protein (MAVS) but not NF-κB signaling. Collectively, these data suggest that Pnpt1 is an important mediator of inflammation, as shown by activation of the NLRP3 inflammasome in murine sepsis and cultured macrophages.
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Affiliation(s)
- Chia George Hsu
- Department of Medicine, Aab Cardiovascular Research Institute, University of Rochester, Rochester, NY, USA
| | - Wenjia Li
- Department of Medicine, Aab Cardiovascular Research Institute, University of Rochester, Rochester, NY, USA
- Department of Cardiovascular Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China
| | - Mark Sowden
- Department of Medicine, Aab Cardiovascular Research Institute, University of Rochester, Rochester, NY, USA
| | - Camila Lage Chávez
- Department of Medicine, Aab Cardiovascular Research Institute, University of Rochester, Rochester, NY, USA
| | - Bradford C Berk
- Department of Medicine, Aab Cardiovascular Research Institute, University of Rochester, Rochester, NY, USA.
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6
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Ventura I, Revert F, Revert-Ros F, Gómez-Tatay L, Prieto-Ruiz JA, Hernández-Andreu JM. SP1 and NFY Regulate the Expression of PNPT1, a Gene Encoding a Mitochondrial Protein Involved in Cancer. Int J Mol Sci 2022; 23:ijms231911399. [PMID: 36232701 PMCID: PMC9570217 DOI: 10.3390/ijms231911399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/13/2022] [Accepted: 09/23/2022] [Indexed: 11/26/2022] Open
Abstract
The Polyribonucleotide nucleotidyltransferase 1 gene (PNPT1) encodes polynucleotide phosphorylase (PNPase), a 3′-5′ exoribonuclease involved in mitochondrial RNA degradation and surveillance and RNA import into the mitochondrion. Here, we have characterized the PNPT1 promoter by in silico analysis, luciferase reporter assays, electrophoretic mobility shift assays (EMSA), chromatin immunoprecipitation (ChIP), siRNA-based mRNA silencing and RT-qPCR. We show that the Specificity protein 1 (SP1) transcription factor and Nuclear transcription factor Y (NFY) bind the PNPT1 promoter, and have a relevant role regulating the promoter activity, PNPT1 expression, and mitochondrial activity. We also found in Kaplan–Meier survival curves that a high expression of either PNPase, SP1 or NFY subunit A (NFYA) is associated with a poor prognosis in liver cancer. In summary, our results show the relevance of SP1 and NFY in PNPT1 expression, and point to SP1/NFY and PNPase as possible targets in anti-cancer therapy.
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7
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How RNases Shape Mitochondrial Transcriptomes. Int J Mol Sci 2022; 23:ijms23116141. [PMID: 35682820 PMCID: PMC9181182 DOI: 10.3390/ijms23116141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/17/2022] Open
Abstract
Mitochondria are the power houses of eukaryote cells. These endosymbiotic organelles of prokaryote origin are considered as semi-autonomous since they have retained a genome and fully functional gene expression mechanisms. These pathways are particularly interesting because they combine features inherited from the bacterial ancestor of mitochondria with characteristics that appeared during eukaryote evolution. RNA biology is thus particularly diverse in mitochondria. It involves an unexpectedly vast array of factors, some of which being universal to all mitochondria and others being specific from specific eukaryote clades. Among them, ribonucleases are particularly prominent. They play pivotal functions such as the maturation of transcript ends, RNA degradation and surveillance functions that are required to attain the pool of mature RNAs required to synthesize essential mitochondrial proteins such as respiratory chain proteins. Beyond these functions, mitochondrial ribonucleases are also involved in the maintenance and replication of mitochondrial DNA, and even possibly in the biogenesis of mitochondrial ribosomes. The diversity of mitochondrial RNases is reviewed here, showing for instance how in some cases a bacterial-type enzyme was kept in some eukaryotes, while in other clades, eukaryote specific enzymes were recruited for the same function.
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8
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Falchi FA, Pizzoccheri R, Briani F. Activity and Function in Human Cells of the Evolutionary Conserved Exonuclease Polynucleotide Phosphorylase. Int J Mol Sci 2022; 23:ijms23031652. [PMID: 35163574 PMCID: PMC8836086 DOI: 10.3390/ijms23031652] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 01/28/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023] Open
Abstract
Polynucleotide phosphorylase (PNPase) is a phosphorolytic RNA exonuclease highly conserved throughout evolution. Human PNPase (hPNPase) is located in mitochondria and is essential for mitochondrial function and homeostasis. Not surprisingly, mutations in the PNPT1 gene, encoding hPNPase, cause serious diseases. hPNPase has been implicated in a plethora of processes taking place in different cell compartments and involving other proteins, some of which physically interact with hPNPase. This paper reviews hPNPase RNA binding and catalytic activity in relation with the protein structure and in comparison, with the activity of bacterial PNPases. The functions ascribed to hPNPase in different cell compartments are discussed, highlighting the gaps that still need to be filled to understand the physiological role of this ancient protein in human cells.
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9
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Santeford A, Lee AY, Sene A, Hassman LM, Sergushichev AA, Loginicheva E, Artyomov MN, Ruzycki PA, Apte RS. Loss of Mir146b with aging contributes to inflammation and mitochondrial dysfunction in thioglycollate-elicited peritoneal macrophages. eLife 2021; 10:e66703. [PMID: 34423778 PMCID: PMC8412946 DOI: 10.7554/elife.66703] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 08/20/2021] [Indexed: 12/12/2022] Open
Abstract
Macrophages undergo programmatic changes with age, leading to altered cytokine polarization and immune dysfunction, shifting these critical immune cells from protective sentinels to disease promoters. The molecular mechanisms underlying macrophage inflammaging are poorly understood. Using an unbiased RNA sequencing (RNA-seq) approach, we identified Mir146b as a microRNA whose expression progressively and unidirectionally declined with age in thioglycollate-elicited murine macrophages. Mir146b deficiency led to altered macrophage cytokine expression and reduced mitochondrial metabolic activity, two hallmarks of cellular aging. Single-cell RNA-seq identified patterns of altered inflammation and interferon gamma signaling in Mir146b-deficient macrophages. Identification of Mir146b as a potential regulator of macrophage aging provides novel insights into immune dysfunction associated with aging.
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Affiliation(s)
- Andrea Santeford
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Aaron Y Lee
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Abdoulaye Sene
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Lynn M Hassman
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Alexey A Sergushichev
- Department of Pathology and Immunology, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Ekaterina Loginicheva
- Department of Pathology and Immunology, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Maxim N Artyomov
- Department of Pathology and Immunology, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Philip A Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of MedicineSt. LouisUnited States
| | - Rajendra S Apte
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of MedicineSt. LouisUnited States
- Department of Medicine, Washington University in St. Louis School of MedicineSt. LouisUnited States
- Department of Developmental Biology, Washington University in St. Louis School of MedicineSt. LouisUnited States
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10
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Garcia-Mayea Y, Mir C, Masson F, Paciucci R, LLeonart ME. Insights into new mechanisms and models of cancer stem cell multidrug resistance. Semin Cancer Biol 2020; 60:166-180. [PMID: 31369817 DOI: 10.1016/j.semcancer.2019.07.022] [Citation(s) in RCA: 170] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 12/24/2022]
Abstract
The acquisition of genetic alterations, clonal evolution, and the tumor microenvironment promote cancer progression, metastasis and therapy resistance. These events correspond to the establishment of the great phenotypic heterogeneity and plasticity of cancer cells that contribute to tumor progression and resistant disease. Targeting resistant cancers is a major challenge in oncology; however, the underlying processes are not yet fully understood. Even though current treatments can reduce tumor size and increase life expectancy, relapse and multidrug resistance (MDR) ultimately remain the second cause of death in developed countries. Recent evidence points toward stem-like phenotypes in cancer cells, promoted by cancer stem cells (CSCs), as the main culprit of cancer relapse, resistance (radiotherapy, hormone therapy, and/or chemotherapy) and metastasis. Many mechanisms have been proposed for CSC resistance, such as drug efflux through ABC transporters, overactivation of the DNA damage response (DDR), apoptosis evasion, prosurvival pathways activation, cell cycle promotion and/or cell metabolic alterations. Nonetheless, targeted therapy toward these specific CSC mechanisms is only partially effective to prevent or abolish resistance, suggesting underlying additional causes for CSC resilience. This article aims to provide an integrated picture of the MDR mechanisms that operate in CSCs' behavior and to propose a novel model of tumor evolution during chemotherapy. Targeting the pathways mentioned here might hold promise and reveal new strategies for future clinical therapeutic approaches.
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Affiliation(s)
- Y Garcia-Mayea
- Biomedical Research in Cancer Stem Cells, Vall d´Hebron Research Institute (VHIR), Passeig Vall d´Hebron 119-129, 08035 Barcelona, Spain
| | - C Mir
- Biomedical Research in Cancer Stem Cells, Vall d´Hebron Research Institute (VHIR), Passeig Vall d´Hebron 119-129, 08035 Barcelona, Spain
| | - F Masson
- Biomedical Research in Cancer Stem Cells, Vall d´Hebron Research Institute (VHIR), Passeig Vall d´Hebron 119-129, 08035 Barcelona, Spain
| | - R Paciucci
- Clinical Biochemistry Group, Vall d'Hebron Hospital and Vall d´Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d´Hebron 119-129, 08035 Barcelona, Spain
| | - M E LLeonart
- Biomedical Research in Cancer Stem Cells, Vall d´Hebron Research Institute (VHIR), Passeig Vall d´Hebron 119-129, 08035 Barcelona, Spain; Spanish Biomedical Research Network Centre in Oncology, CIBERONC, Spain.
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11
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Cameron TA, Matz LM, De Lay NR. Polynucleotide phosphorylase: Not merely an RNase but a pivotal post-transcriptional regulator. PLoS Genet 2018; 14:e1007654. [PMID: 30307990 PMCID: PMC6181284 DOI: 10.1371/journal.pgen.1007654] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Almost 60 years ago, Severo Ochoa was awarded the Nobel Prize in Physiology or Medicine for his discovery of the enzymatic synthesis of RNA by polynucleotide phosphorylase (PNPase). Although this discovery provided an important tool for deciphering the genetic code, subsequent work revealed that the predominant function of PNPase in bacteria and eukaryotes is catalyzing the reverse reaction, i.e., the release of ribonucleotides from RNA. PNPase has a crucial role in RNA metabolism in bacteria and eukaryotes mainly through its roles in processing and degrading RNAs, but additional functions in RNA metabolism have recently been reported for this enzyme. Here, we discuss these established and noncanonical functions for PNPase and the possibility that the major impact of PNPase on cell physiology is through its unorthodox roles.
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Affiliation(s)
- Todd A. Cameron
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, United States of America
| | - Lisa M. Matz
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, United States of America
| | - Nicholas R. De Lay
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, United States of America
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas, United States of America
- * E-mail:
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