1
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Zhang J, Ruiz M, Bergh PO, Henricsson M, Stojanović N, Devkota R, Henn M, Bohlooly-Y M, Hernández-Hernández A, Alsheimer M, Borén J, Pilon M, Shibuya H. Regulation of meiotic telomere dynamics through membrane fluidity promoted by AdipoR2-ELOVL2. Nat Commun 2024; 15:2315. [PMID: 38485951 PMCID: PMC10940294 DOI: 10.1038/s41467-024-46718-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 02/29/2024] [Indexed: 03/18/2024] Open
Abstract
The cellular membrane in male meiotic germ cells contains a unique class of phospholipids and sphingolipids that is required for male reproduction. Here, we show that a conserved membrane fluidity sensor, AdipoR2, regulates the meiosis-specific lipidome in mouse testes by promoting the synthesis of sphingolipids containing very-long-chain polyunsaturated fatty acids (VLC-PUFAs). AdipoR2 upregulates the expression of a fatty acid elongase, ELOVL2, both transcriptionally and post-transcriptionally, to synthesize VLC-PUFA. The depletion of VLC-PUFAs and subsequent accumulation of palmitic acid in AdipoR2 knockout testes stiffens the cellular membrane and causes the invagination of the nuclear envelope. This condition impairs the nuclear peripheral distribution of meiotic telomeres, leading to errors in homologous synapsis and recombination. Further, the stiffened membrane impairs the formation of intercellular bridges and the germ cell syncytium, which disrupts the orderly arrangement of cell types within the seminiferous tubules. According to our findings we propose a framework in which the highly-fluid membrane microenvironment shaped by AdipoR2-ELOVL2 underpins meiosis-specific chromosome dynamics in testes.
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Affiliation(s)
- Jingjing Zhang
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden
| | - Per-Olof Bergh
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, 41467, Gothenburg, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, 41467, Gothenburg, Sweden
| | - Nena Stojanović
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden
| | - Marius Henn
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074, Würzburg, Germany
| | | | - Abrahan Hernández-Hernández
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
- National Genomics Infrastructure, Science for Life Laboratory, Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Manfred Alsheimer
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074, Würzburg, Germany
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, 41467, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden.
| | - Hiroki Shibuya
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden.
- Laboratory for Gametogenesis, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan.
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2
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Palmgren H, Petkevicius K, Bartesaghi S, Ahnmark A, Ruiz M, Nilsson R, Löfgren L, Glover MS, Andréasson AC, Andersson L, Becquart C, Kurczy M, Kull B, Wallin S, Karlsson D, Hess S, Maresca M, Bohlooly-Y M, Peng XR, Pilon M. Elevated Adipocyte Membrane Phospholipid Saturation Does Not Compromise Insulin Signaling. Diabetes 2023; 72:1350-1363. [PMID: 36580483 PMCID: PMC10545576 DOI: 10.2337/db22-0293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 12/24/2022] [Indexed: 12/30/2022]
Abstract
Increased saturated fatty acid (SFA) levels in membrane phospholipids have been implicated in the development of metabolic disease. Here, we tested the hypothesis that increased SFA content in cell membranes negatively impacts adipocyte insulin signaling. Preadipocyte cell models with elevated SFA levels in phospholipids were generated by disrupting the ADIPOR2 locus, which resulted in a striking twofold increase in SFA-containing phosphatidylcholines and phosphatidylethanolamines, which persisted in differentiated adipocytes. Similar changes in phospholipid composition were observed in white adipose tissues isolated from the ADIPOR2-knockout mice. The SFA levels in phospholipids could be further increased by treating ADIPOR2-deficient cells with palmitic acid and resulted in reduced membrane fluidity and endoplasmic reticulum stress in mouse and human preadipocytes. Strikingly, increased SFA levels in differentiated adipocyte phospholipids had no effect on adipocyte gene expression or insulin signaling in vitro. Similarly, increased adipocyte phospholipid saturation did not impair white adipose tissue function in vivo, even in mice fed a high-saturated fat diet at thermoneutrality. We conclude that increasing SFA levels in adipocyte phospholipids is well tolerated and does not affect adipocyte insulin signaling in vitro and in vivo.
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Affiliation(s)
- Henrik Palmgren
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Kasparas Petkevicius
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Stefano Bartesaghi
- Translational Science and Experimental Medicine, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Andrea Ahnmark
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ralf Nilsson
- Translational Science and Experimental Medicine, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Lars Löfgren
- Translational Science and Experimental Medicine, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Matthew S. Glover
- Dynamic Omics, Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD
| | - Anne-Christine Andréasson
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Liselotte Andersson
- Animal Science & Technologies, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Cécile Becquart
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Michael Kurczy
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Bengt Kull
- Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Simonetta Wallin
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Daniel Karlsson
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Sonja Hess
- Dynamic Omics, Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD
| | - Marcello Maresca
- Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Xiao-Rong Peng
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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3
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Pilon M, Ruiz M. PAQR proteins and the evolution of a superpower: Eating all kinds of fats: Animals rely on evolutionarily conserved membrane homeostasis proteins to compensate for dietary variation. Bioessays 2023; 45:e2300079. [PMID: 37345585 DOI: 10.1002/bies.202300079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/23/2023]
Abstract
Recently published work showed that members of the PAQR protein family are activated by cell membrane rigidity and contribute to our ability to eat a wide variety of diets. Cell membranes are primarily composed of phospholipids containing dietarily obtained fatty acids, which poses a challenge to membrane properties because diets can vary greatly in their fatty acid composition and could impart opposite properties to the cellular membranes. In particular, saturated fatty acids (SFAs) can pack tightly and form rigid membranes (like butter at room temperature) while unsaturated fatty acids (UFAs) form more fluid membranes (like vegetable oils). Proteins of the PAQR protein family, characterized by the presence of seven transmembrane domains and a cytosolic N-terminus, contribute to membrane homeostasis in bacteria, yeasts, and animals. These proteins respond to membrane rigidity by stimulating fatty acid desaturation and incorporation of UFAs into phospholipids and explain the ability of animals to thrive on diets with widely varied fat composition. Also see the video abstract here: https://youtu.be/6ckcvaDdbQg.
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Affiliation(s)
- Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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4
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Ruiz M, Devkota R, Kaper D, Ruhanen H, Busayavalasa K, Radović U, Henricsson M, Käkelä R, Borén J, Pilon M. AdipoR2 recruits protein interactors to promote fatty acid elongation and membrane fluidity. J Biol Chem 2023:104799. [PMID: 37164154 DOI: 10.1016/j.jbc.2023.104799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/12/2023] Open
Abstract
The human AdipoR2 and its C. elegans homolog PAQR-2 are multi-pass plasma membrane proteins that protect cells against membrane rigidification. However, how AdipoR2 promotes membrane fluidity mechanistically is not clear. Using 13C-labelled fatty acids, we show that AdipoR2 can promote the elongation and incorporation of membrane-fluidizing polyunsaturated fatty acids into phospholipids. To elucidate the molecular basis of these activities, we performed immunoprecipitations of tagged AdipoR2 and PAQR-2 expressed in HEK293 cells or whole C. elegans, respectively, and identified co-immunoprecipitated proteins using mass spectroscopy. We found that several of the evolutionarily conserved AdipoR2/PAQR-2 interactors are important for fatty acid elongation and incorporation into phospholipids. We experimentally verified some of these interactions, namely with the dehydratase HACD3 that is essential for the third of four steps in long-chain fatty acid elongation, and ACSL4 that is important for activation of unsaturated fatty acids and their channeling into phospholipids. We conclude that AdipoR2 and PAQR-2 can recruit protein interactors to promote the production and incorporation of unsaturated fatty acids into phospholipids.
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Affiliation(s)
- Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Delaney Kaper
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Hanna Ruhanen
- Helsinki University Lipidomics Unit, Helsinki Institute of Life Science, Biocenter Finland, Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Kiran Busayavalasa
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Uroš Radović
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Reijo Käkelä
- Helsinki University Lipidomics Unit, Helsinki Institute of Life Science, Biocenter Finland, Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
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5
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Laudette M, Lindbom M, Arif M, Cinato M, Ruiz M, Doran S, Miljanovic A, Rutberg M, Andersson L, Klevstig M, Henricsson M, Bergh PO, Bollano E, Aung N, Smith JG, Pilon M, Hyötyläinen T, Orešič M, Perkins R, Mardinoglu A, Levin MC, Borén J. Cardiomyocyte-specific PCSK9 deficiency compromises mitochondrial bioenergetics and heart function. Cardiovasc Res 2023:7070420. [PMID: 36880401 DOI: 10.1093/cvr/cvad041] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/23/2022] [Accepted: 01/09/2023] [Indexed: 03/08/2023] Open
Abstract
AIMS PCSK9, which is expressed mainly in the liver and at low levels in the heart, regulates cholesterol levels by directing low-density lipoprotein receptors to degradation. Studies to determine the role of PCSK9 in the heart are complicated by the close link between cardiac function and systemic lipid metabolism. Here, we sought to elucidate the function of PCSK9 specifically in the heart by generating and analysing mice with cardiomyocyte-specific Pcsk9 deficiency (CM-Pcsk9-/- mice) and by silencing Pcsk9 acutely in a cell culture model of adult cardiomyocyte-like cells. METHODS AND RESULTS Mice with cardiomyocyte-specific deletion of Pcsk9 had reduced contractile capacity, impaired cardiac function and left ventricular dilatation at 28 weeks of age and died prematurely. Transcriptomic analyses revealed alterations of signalling pathways linked to cardiomyopathy and energy metabolism in hearts from CM-Pcsk9-/- mice versus wildtype littermates. In agreement, levels of genes and proteins involved in mitochondrial metabolism were reduced in CM-Pcsk9-/- hearts. By using a Seahorse flux analyser, we showed that mitochondrial but not glycolytic function was impaired in cardiomyocytes from CM-Pcsk9-/- mice. We further showed that assembly and activity of electron transport chain (ETC) complexes were altered in isolated mitochondria from CM-Pcsk9-/- mice. Circulating lipid levels were unchanged in CM-Pcsk9-/- mice, but the lipid composition of mitochondrial membranes was altered. In addition, cardiomyocytes from CM-Pcsk9-/- mice had an increased number of mitochondria-ER contacts and alterations in the morphology of cristae, the physical location of the ETC complexes. We also showed that acute Pcsk9 silencing in adult cardiomyocyte-like cells reduced the activity of ETC complexes and impaired mitochondrial metabolism. CONCLUSION PCSK9, despite its low expression in cardiomyocytes, contributes to cardiac metabolic function, and PCSK9 deficiency in cardiomyocytes is linked to cardiomyopathy, impaired heart function, and compromised energy production. TRANSLATIONAL PERSPECTIVE PCSK9 is mainly present in the circulation where it regulates plasma cholesterol levels. Here we show that PCSK9 mediates intracellular functions that differ from its extracellular functions. We further show that intracellular PCSK9 in cardiomyocytes, despite low expression levels, is important for maintaining physiological cardiac metabolism and function.
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Affiliation(s)
- Marion Laudette
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Malin Lindbom
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Muhammad Arif
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Mathieu Cinato
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Stephen Doran
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, United Kingdom
| | - Azra Miljanovic
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Mikael Rutberg
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Linda Andersson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Martina Klevstig
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Per-Olof Bergh
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Entela Bollano
- Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Nay Aung
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom.,National Institute for Health Research, Barts Cardiovascular Biomedical Research Centre, Queen Mary University of London, United Kingdom.,Barts Heart Centre, St Bartholomew's Hospital, Barts Health National Health Service Trust, West Smithfield, London, United Kingdom
| | - J Gustav Smith
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.,Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Tuulia Hyötyläinen
- School of Natural Sciences and Technology, Örebro University, Örebro, Sweden
| | - Matej Orešič
- School of Medical Sciences, Örebro University, Örebro, Sweden.,Turku Bioscience Centre, University of Turku, Turku, Finland
| | - Rosie Perkins
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Adil Mardinoglu
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden.,Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, United Kingdom
| | - Malin C Levin
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.,Sahlgrenska University Hospital, Gothenburg, Sweden
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6
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Pilon M. AdipoR2 promotes fatty acid desaturation, elongation and incorporation into phospholipids in response to membrane rigidification. Biophys J 2023; 122:4a. [PMID: 36784580 DOI: 10.1016/j.bpj.2022.11.258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Marc Pilon
- University of Gothenburg, Gothenburg, Sweden
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7
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Petkevicius K, Palmgren H, Glover MS, Ahnmark A, Andréasson AC, Madeyski-Bengtson K, Kawana H, Allman EL, Kaper D, Uhrbom M, Andersson L, Aasehaug L, Forsström J, Wallin S, Ahlstedt I, Leke R, Karlsson D, González-King H, Löfgren L, Nilsson R, Pellegrini G, Kono N, Aoki J, Hess S, Sienski G, Pilon M, Bohlooly-Y M, Maresca M, Peng XR. TLCD1 and TLCD2 regulate cellular phosphatidylethanolamine composition and promote the progression of non-alcoholic steatohepatitis. Nat Commun 2022; 13:6020. [PMID: 36241646 PMCID: PMC9568529 DOI: 10.1038/s41467-022-33735-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 09/29/2022] [Indexed: 11/29/2022] Open
Abstract
The fatty acid composition of phosphatidylethanolamine (PE) determines cellular metabolism, oxidative stress, and inflammation. However, our understanding of how cells regulate PE composition is limited. Here, we identify a genetic locus on mouse chromosome 11, containing two poorly characterized genes Tlcd1 and Tlcd2, that strongly influences PE composition. We generated Tlcd1/2 double-knockout (DKO) mice and found that they have reduced levels of hepatic monounsaturated fatty acid (MUFA)-containing PE species. Mechanistically, TLCD1/2 proteins act cell intrinsically to promote the incorporation of MUFAs into PEs. Furthermore, TLCD1/2 interact with the mitochondria in an evolutionarily conserved manner and regulate mitochondrial PE composition. Lastly, we demonstrate the biological relevance of our findings in dietary models of metabolic disease, where Tlcd1/2 DKO mice display attenuated development of non-alcoholic steatohepatitis compared to controls. Overall, we identify TLCD1/2 proteins as key regulators of cellular PE composition, with our findings having broad implications in understanding and treating disease. The regulation of cellular phosphatidylethanolamine (PE) acyl chain composition is poorly understood. Here, the authors show that TLCD1 and TLCD2 proteins mediate the formation of monounsaturated fatty acid-containing PE species and promote the progression of non-alcoholic steatohepatitis.
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Affiliation(s)
- Kasparas Petkevicius
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden. .,Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden.
| | - Henrik Palmgren
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden.,Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Matthew S Glover
- Dynamic Omics, Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Andrea Ahnmark
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Anne-Christine Andréasson
- Bioscience Cardiovascular, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Hiroki Kawana
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.,Advanced Research & Development Programs for Medical Innovation (AMED-LEAP), Tokyo, Japan
| | - Erik L Allman
- Dynamic Omics, Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Delaney Kaper
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Martin Uhrbom
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Liselotte Andersson
- Clinical Pharmacology and Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Leif Aasehaug
- Bioscience Cardiovascular, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Johan Forsström
- Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Simonetta Wallin
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Ingela Ahlstedt
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Renata Leke
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Daniel Karlsson
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Hernán González-King
- Bioscience Cardiovascular, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Lars Löfgren
- Translational Science and Experimental Medicine, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Ralf Nilsson
- Translational Science and Experimental Medicine, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Giovanni Pellegrini
- Clinical Pharmacology and Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Nozomu Kono
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Junken Aoki
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.,Advanced Research & Development Programs for Medical Innovation (AMED-LEAP), Tokyo, Japan
| | - Sonja Hess
- Dynamic Omics, Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Grzegorz Sienski
- Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | | | - Marcello Maresca
- Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Xiao-Rong Peng
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
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8
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Ruiz M, Svensk E, Einarsson E, Grahn EP, Pilon M. A small molecule screen for paqr-2 suppressors identifies Tyloxapol as a membrane fluidizer for C. elegans and mammalian cells. Biochim Biophys Acta Biomembr 2022; 1864:183959. [PMID: 35588889 DOI: 10.1016/j.bbamem.2022.183959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/20/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Defects in cell membrane homeostasis are implicated in numerous disorders, including cancer, neurodegeneration and diabetes. There is therefore a need for a powerful model to study membrane homeostasis and to identify eventual therapeutic routes. The C. elegans gene paqr-2 encodes a homolog of the mammalian AdipoR1 and AdipoR2 proteins that, when mutated, causes a membrane homeostasis defect accompanied by multiple phenotypes such as intolerance to dietary saturated fatty acids, intolerance to cold and a characteristic tail tip morphology defect. We screened a compound library to identify molecules that can suppress the paqr-2 phenotypes. A single positive hit, Tyloxapol, was found that very effectively suppresses multiple paqr-2 phenotypes. Tyloxapol is a non-ionic detergent currently in use clinically as an expectorant. Importantly, we examined the potential of Tyloxapol as a fluidizer in human cells and found that it improves the viability and membrane fluidity of AdipoR2-deficient human cells challenged with palmitic acid, a membrane-rigidifying saturated fatty acid.
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Affiliation(s)
- Mario Ruiz
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Emma Svensk
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Elinor Einarsson
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Erik Podda Grahn
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Marc Pilon
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden.
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9
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Ruiz M, Henricsson M, Borén J, Pilon M. Palmitic acid causes increased dihydroceramide levels when desaturase expression is directly silenced or indirectly lowered by silencing AdipoR2. Lipids Health Dis 2021; 20:173. [PMID: 34839823 PMCID: PMC8627610 DOI: 10.1186/s12944-021-01600-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/13/2021] [Indexed: 11/10/2022] Open
Abstract
Background AdipoR1 and AdipoR2 (AdipoRs) are plasma membrane proteins often considered to act as adiponectin receptors with a ceramidase activity. Additionally, the AdipoRs and their yeast and C. elegans orthologs are emerging as membrane homeostasis regulators that counter membrane rigidification by promoting fatty acid desaturation and incorporation of unsaturated fatty acids into phospholipids, thus restoring fluidity. Methods Using cultured cells, the effects of AdipoR silencing or over-expression on the levels and composition of several sphingolipid classes were examined. Results AdipoR2 silencing in the presence of exogenous palmitic acid potently causes increased levels of dihydroceramides, a ceramide precursor in the de novo ceramide synthesis pathway. Conversely, AdipoR2 over-expression caused a depletion of dihydroceramides. Conclusions The results are consistent with AdipoR2 silencing leading to increased intracellular supply of palmitic acid that in turn leads to increased dihydroceramide synthesis via the rate-limiting serine palmitoyl transferase step. In agreement with this model, inhibiting the desaturase SCD or SREBF1/2 (positive regulators of SCD) also causes a strong increase in dihydroceramide levels. Supplementary Information The online version contains supplementary material available at 10.1186/s12944-021-01600-y.
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Affiliation(s)
- Mario Ruiz
- Department Chemistry and Molecular Biology, Univ. Gothenburg, Box 462, 405 30, Gothenburg, Sweden
| | - Marcus Henricsson
- Department Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30, Gothenburg, Sweden
| | - Jan Borén
- Department Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30, Gothenburg, Sweden
| | - Marc Pilon
- Department Chemistry and Molecular Biology, Univ. Gothenburg, Box 462, 405 30, Gothenburg, Sweden.
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10
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Besse L, Besse A, Stolze SC, Sobh A, Zaal EA, van der Ham AJ, Ruiz M, Phuyal S, Büchler L, Sathianathan M, Florea BI, Borén J, Ståhlman M, Huber J, Bolomsky A, Ludwig H, Hannich JT, Loguinov A, Everts B, Berkers CR, Pilon M, Farhan H, Vulpe CD, Overkleeft HS, Driessen C. Treatment with HIV-Protease Inhibitor Nelfinavir Identifies Membrane Lipid Composition and Fluidity as a Therapeutic Target in Advanced Multiple Myeloma. Cancer Res 2021; 81:4581-4593. [PMID: 34158378 DOI: 10.1158/0008-5472.can-20-3323] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 04/30/2021] [Accepted: 06/21/2021] [Indexed: 11/16/2022]
Abstract
The HIV-protease inhibitor nelfinavir has shown broad anticancer activity in various preclinical and clinical contexts. In patients with advanced, proteasome inhibitor (PI)-refractory multiple myeloma, nelfinavir-based therapy resulted in 65% partial response or better, suggesting that this may be a highly active chemotherapeutic option in this setting. The broad anticancer mechanism of action of nelfinavir implies that it interferes with fundamental aspects of cancer cell biology. We combined proteome-wide affinity-purification of nelfinavir-interacting proteins with genome-wide CRISPR/Cas9-based screening to identify protein partners that interact with nelfinavir in an activity-dependent manner alongside candidate genetic contributors affecting nelfinavir cytotoxicity. Nelfinavir had multiple activity-specific binding partners embedded in lipid bilayers of mitochondria and the endoplasmic reticulum. Nelfinavir affected the fluidity and composition of lipid-rich membranes, disrupted mitochondrial respiration, blocked vesicular transport, and affected the function of membrane-embedded drug efflux transporter ABCB1, triggering the integrated stress response. Sensitivity to nelfinavir was dependent on ADIPOR2, which maintains membrane fluidity by promoting fatty acid desaturation and incorporation into phospholipids. Supplementation with fatty acids prevented the nelfinavir-induced effect on mitochondrial metabolism, drug-efflux transporters, and stress-response activation. Conversely, depletion of fatty acids/cholesterol pools by the FDA-approved drug ezetimibe showed a synergistic anticancer activity with nelfinavir in vitro. These results identify the modification of lipid-rich membranes by nelfinavir as a novel mechanism of action to achieve broad anticancer activity, which may be suitable for the treatment of PI-refractory multiple myeloma. SIGNIFICANCE: Nelfinavir induces lipid bilayer stress in cellular organelles that disrupts mitochondrial respiration and transmembrane protein transport, resulting in broad anticancer activity via metabolic rewiring and activation of the unfolded protein response.
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Affiliation(s)
- Lenka Besse
- Laboratory of Experimental Oncology, Clinic for Medical Oncology and Hematology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
| | - Andrej Besse
- Laboratory of Experimental Oncology, Clinic for Medical Oncology and Hematology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Sara C Stolze
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Amin Sobh
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Esther A Zaal
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Alwin J van der Ham
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Santosh Phuyal
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Lorina Büchler
- Laboratory of Experimental Oncology, Clinic for Medical Oncology and Hematology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Marc Sathianathan
- Laboratory of Experimental Oncology, Clinic for Medical Oncology and Hematology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Bogdan I Florea
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Julia Huber
- Department of Medicine I, Wilhelminen Cancer Research Institute, Klinik Ottakring, Vienna, Austria
| | - Arnold Bolomsky
- Department of Medicine I, Wilhelminen Cancer Research Institute, Klinik Ottakring, Vienna, Austria
| | - Heinz Ludwig
- Department of Medicine I, Wilhelminen Cancer Research Institute, Klinik Ottakring, Vienna, Austria
| | - J Thomas Hannich
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Alex Loguinov
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Bart Everts
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Celia R Berkers
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Hesso Farhan
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Institute of Pathophysiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Christopher D Vulpe
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | | | - Christoph Driessen
- Laboratory of Experimental Oncology, Clinic for Medical Oncology and Hematology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
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Devkota R, Kaper D, Bodhicharla R, Henricsson M, Borén J, Pilon M. A Genetic Titration of Membrane Composition in C. elegans Reveals its Importance for Multiple Cellular and Physiological Traits. Genetics 2021; 219:6298595. [PMID: 34125894 PMCID: PMC9335940 DOI: 10.1093/genetics/iyab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 06/08/2021] [Indexed: 12/21/2022] Open
Abstract
Communicating editor: B. Grant The composition and biophysical properties of cellular membranes must be tightly regulated to maintain the proper functions of myriad processes within cells. To better understand the importance of membrane homeostasis, we assembled a panel of five Caenorhabditis elegans strains that show a wide span of membrane composition and properties, ranging from excessively rich in saturated fatty acids (SFAs) and rigid to excessively rich in polyunsaturated fatty acids (PUFAs) and fluid. The genotypes of the five strain are, from most rigid to most fluid: paqr-1(tm3262); paqr-2(tm3410), paqr-2(tm3410), N2 (wild-type), mdt-15(et14); nhr-49(et8), and mdt-15(et14); nhr-49(et8); acs-13(et54). We confirmed the excess SFA/rigidity-to-excess PUFA/fluidity gradient using the methods of fluorescence recovery after photobleaching (FRAP) and lipidomics analysis. The five strains were then studied for a variety of cellular and physiological traits and found to exhibit defects in: permeability, lipid peroxidation, growth at different temperatures, tolerance to SFA-rich diets, lifespan, brood size, vitellogenin trafficking, oogenesis, and autophagy during starvation. The excessively rigid strains often exhibited defects in opposite directions compared to the excessively fluid strains. We conclude that deviation from wild-type membrane homeostasis is pleiotropically deleterious for numerous cellular/physiological traits. The strains introduced here should prove useful to further study the cellular and physiological consequences of impaired membrane homeostasis.
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Affiliation(s)
- Ranjan Devkota
- Dept.Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden
| | - Delaney Kaper
- Dept.Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden
| | - Rakesh Bodhicharla
- Dept.Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden
| | - Marcus Henricsson
- Dept. Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30 Gothenburg, Sweden
| | - Jan Borén
- Dept. Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30 Gothenburg, Sweden
| | - Marc Pilon
- Dept.Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden
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12
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Abstract
The ADIPOR1 and ADIPOR2 proteins (ADIPORs) are generally considered as adiponectin receptors with anti-diabetic properties. However, studies on the yeast and C. elegans homologs of the mammalian ADIPORs, and of the ADIPORs themselves in various mammalian cell models, support an updated/different view. Based on findings in these experimental models, the ADIPORs are now emerging as evolutionarily conserved regulators of membrane homeostasis that do not require adiponectin to act as membrane fluidity sensors and regulate phospholipid composition. More specifically, membrane rigidification activates ADIPOR signaling to promote fatty acid desaturation and incorporation of polyunsaturated fatty acids into membrane phospholipids until fluidity is restored. The present review summarizes the evidence supporting this new view of the ADIPORs, and briefly examines physiological consequences.
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Affiliation(s)
- Marc Pilon
- Dept. Chemistry and Molecular Biology, Univ. Gothenburg, Box 462, S-405 30, Gothenburg, Sweden.
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13
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Devkota R, Henricsson M, Borén J, Pilon M. The C. elegans PAQR-2 and IGLR-2 membrane homeostasis proteins are uniquely essential for tolerating dietary saturated fats. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158883. [PMID: 33444761 DOI: 10.1016/j.bbalip.2021.158883] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/18/2020] [Accepted: 01/06/2021] [Indexed: 01/07/2023]
Abstract
How cells maintain vital membrane lipid homeostasis while obtaining most of their constituent fatty acids from a varied diet remains largely unknown. Here, we report the first whole-organism (Caenorhabditis elegans) forward genetic screen to identify genes essential for tolerance to dietary saturated fatty acids (SFAs). We found that only the PAQR-2/IGLR-2 pathway, homologous to the human adiponectin receptor 2 (AdipoR2) pathway, is uniquely essential to prevent SFA-mediated toxicity. When provided a SFA-rich diet, worms lacking either protein accumulate an excess of SFAs in their membrane phospholipids, which is accompanied by membrane rigidification. Additionally, we used fluorescence resonance energy transfer (FRET) to show that the interaction between PAQR-2 and IGLR-2 is regulated by membrane fluidity, suggesting a mechanism by which this protein complex senses membrane properties. We also created versions of PAQR-2 that lacked parts of the cytoplasmic N-terminal domain and showed that these were still functional, though still dependent on the interaction with IGLR-2. We conclude that membrane homeostasis via the PAQR-2/IGLR-2 fluidity sensor is the only pathway specifically essential for the non-toxic uptake of dietary SFAs in C. elegans.
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Affiliation(s)
- Ranjan Devkota
- Dept. Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden
| | - Marcus Henricsson
- Dept. Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30 Gothenburg, Sweden
| | - Jan Borén
- Dept. Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30 Gothenburg, Sweden
| | - Marc Pilon
- Dept. Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden.
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14
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Ruiz M, Palmgren H, Henricsson M, Devkota R, Jaiswal H, Maresca M, Bohlooly-Y M, Peng XR, Borén J, Pilon M. Extensive transcription mis-regulation and membrane defects in AdipoR2-deficient cells challenged with saturated fatty acids. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158884. [PMID: 33444759 DOI: 10.1016/j.bbalip.2021.158884] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/18/2020] [Accepted: 01/06/2021] [Indexed: 12/24/2022]
Abstract
How cells maintain vital membrane lipid homeostasis while obtaining most of their constituent fatty acids from a varied diet remains largely unknown. Here, we used transcriptomics, lipidomics, growth and respiration assays, and membrane property analyses in human HEK293 cells or human umbilical vein endothelial cells (HUVEC) to show that the function of AdipoR2 is to respond to membrane rigidification by regulating many lipid metabolism genes. We also show that AdipoR2-dependent membrane homeostasis is critical for growth and respiration in cells challenged with saturated fatty acids. Additionally, we found that AdipoR2 deficiency causes transcriptome and cell physiological defects similar to those observed in SREBP-deficient cells upon SFA challenge. Finally, we compared several genes considered important for lipid homeostasis, namely AdipoR2, SCD, FADS2, PEMT and ACSL4, and found that AdipoR2 and SCD are the most important among these to prevent membrane rigidification and excess saturation when human cells are challenged with exogenous SFAs. We conclude that AdipoR2-dependent membrane homeostasis is one of the primary mechanisms that protects against exogenous SFAs.
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Affiliation(s)
- Mario Ruiz
- Dept. Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden
| | - Henrik Palmgren
- Metabolism Bioscience, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Marcus Henricsson
- Dept. Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30 Gothenburg, Sweden
| | - Ranjan Devkota
- Dept. Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden
| | - Himjyot Jaiswal
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden; CellinkAB, Arvid Wallgrens Backe 20, 413 46 Gothenburg, Sweden
| | - Marcello Maresca
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Xiao-Rong Peng
- Metabolism Bioscience, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Jan Borén
- Dept. Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, Univ. of Gothenburg, 405 30 Gothenburg, Sweden
| | - Marc Pilon
- Dept. Chemistry and Molecular Biology, Univ. Gothenburg, 405 30 Gothenburg, Sweden.
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15
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Zhang X, Blockhuys S, Devkota R, Pilon M, Wittung-Stafshede P. The Caenorhabditis elegans homolog of human copper chaperone Atox1, CUC-1, aids in distal tip cell migration. Biometals 2020; 33:147-157. [PMID: 32506305 PMCID: PMC7295847 DOI: 10.1007/s10534-020-00239-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/30/2020] [Indexed: 12/01/2022]
Abstract
Cell migration is a fundamental biological process involved in for example embryonic development, immune system and wound healing. Cell migration is also a key step in cancer metastasis and the human copper chaperone Atox1 was recently found to facilitate this process in breast cancer cells. To explore the role of the copper chaperone in other cell migration processes, we here investigated the putative involvement of an Atox1 homolog in Caenorhabditis elegans, CUC-1, in distal tip cell migration, which is a key process during the development of the C. elegans gonad. Using knock-out worms, in which the cuc-1 gene was removed by CRISPR-Cas9 technology, we probed life span, brood size, as well as distal tip cell migration in the absence or presence of supplemented copper. Upon scoring of gonads, we found that cuc-1 knock-out, but not wild-type, worms exhibited distal tip cell migration defects in approximately 10–15% of animals and, had a significantly reduced brood size. Importantly, the distal tip cell migration defect was rescued by a wild-type cuc-1 transgene provided to cuc-1 knock-out worms. The results obtained here for C. elegans CUC-1 imply that Atox1 homologs, in addition to their well-known cytoplasmic copper transport, may contribute to developmental cell migration processes.
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Affiliation(s)
- Xiaolu Zhang
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Stéphanie Blockhuys
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390, Gothenburg, Sweden
| | - Pernilla Wittung-Stafshede
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
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Zadra A, Pilon M, Desautels A, Montplaisir J. Stress, dreams and sleep deprivation as precipitating factors for sleepwalking. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.1224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Ruiz M, Bodhicharla R, Ståhlman M, Svensk E, Busayavalasa K, Palmgren H, Ruhanen H, Boren J, Pilon M. Evolutionarily conserved long-chain Acyl-CoA synthetases regulate membrane composition and fluidity. eLife 2019; 8:47733. [PMID: 31769755 PMCID: PMC6901333 DOI: 10.7554/elife.47733] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 11/23/2019] [Indexed: 12/19/2022] Open
Abstract
The human AdipoR1 and AdipoR2 proteins, as well as their C. elegans homolog PAQR-2, protect against cell membrane rigidification by exogenous saturated fatty acids by regulating phospholipid composition. Here, we show that mutations in the C. elegans gene acs-13 help to suppress the phenotypes of paqr-2 mutant worms, including their characteristic membrane fluidity defects. acs-13 encodes a homolog of the human acyl-CoA synthetase ACSL1, and localizes to the mitochondrial membrane where it likely activates long chains fatty acids for import and degradation. Using siRNA combined with lipidomics and membrane fluidity assays (FRAP and Laurdan dye staining) we further show that the human ACSL1 potentiates lipotoxicity by the saturated fatty acid palmitate: silencing ACSL1 protects against the membrane rigidifying effects of palmitate and acts as a suppressor of AdipoR2 knockdown, thus echoing the C. elegans findings. We conclude that acs-13 mutations in C. elegans and ACSL1 knockdown in human cells prevent lipotoxicity by promoting increased levels of polyunsaturated fatty acid-containing phospholipids.
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Affiliation(s)
- Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Rakesh Bodhicharla
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Emma Svensk
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Kiran Busayavalasa
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Henrik Palmgren
- Metabolism BioScience, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Hanna Ruhanen
- Helsinki University Lipidomics Unit, Helsinki Institute for Life Science, Helsinki, Finland.,Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jan Boren
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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de Mendoza D, Pilon M. Control of membrane lipid homeostasis by lipid-bilayer associated sensors: A mechanism conserved from bacteria to humans. Prog Lipid Res 2019; 76:100996. [DOI: 10.1016/j.plipres.2019.100996] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/25/2019] [Accepted: 06/28/2019] [Indexed: 12/31/2022]
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Ruiz M, Ståhlman M, Borén J, Pilon M. AdipoR1 and AdipoR2 maintain membrane fluidity in most human cell types and independently of adiponectin. J Lipid Res 2019; 60:995-1004. [PMID: 30890562 PMCID: PMC6495173 DOI: 10.1194/jlr.m092494] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/07/2019] [Indexed: 12/16/2022] Open
Abstract
The FA composition of phospholipids must be tightly regulated to maintain optimal cell membrane properties and compensate for a highly variable supply of dietary FAs. Previous studies have shown that AdipoR2 and its homologue PAQR-2 are important regulators of phospholipid FA composition in HEK293 cells and Caenorhabditiselegans, respectively. Here we show that both AdipoR1 and AdipoR2 are essential for sustaining desaturase expression and high levels of unsaturated FAs in membrane phospholipids of many human cell types, including primary human umbilical vein endothelial cells, and for preventing membrane rigidification in cells challenged with exogenous palmitate, a saturated FA. Three independent methods confirm the role of the AdipoRs as regulators of membrane composition and fluidity: fluorescence recovery after photobleaching, measurements of Laurdan dye generalized polarization, and mass spectrometry to determine the FA composition of phospholipids. Furthermore, we show that the AdipoRs can prevent lipotoxicity in the complete absence of adiponectin, their putative ligand. We propose that the primary cellular function of AdipoR1 and AdipoR2 is to maintain membrane fluidity in most human cell types and that adiponectin is not required for this function.
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Affiliation(s)
- Mario Ruiz
- Department of Chemistry and Molecular Biology; University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology; University of Gothenburg, Gothenburg, Sweden.
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Ruiz M, Bodhicharla R, Svensk E, Devkota R, Busayavalasa K, Palmgren H, Ståhlman M, Boren J, Pilon M. Membrane fluidity is regulated by the C. elegans transmembrane protein FLD-1 and its human homologs TLCD1/2. eLife 2018; 7:e40686. [PMID: 30509349 PMCID: PMC6279351 DOI: 10.7554/elife.40686] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/04/2018] [Indexed: 12/15/2022] Open
Abstract
Dietary fatty acids are the main building blocks for cell membranes in animals, and mechanisms must therefore exist that compensate for dietary variations. We isolated C. elegans mutants that improved tolerance to dietary saturated fat in a sensitized genetic background, including eight alleles of the novel gene fld-1 that encodes a homolog of the human TLCD1 and TLCD2 transmembrane proteins. FLD-1 is localized on plasma membranes and acts by limiting the levels of highly membrane-fluidizing long-chain polyunsaturated fatty acid-containing phospholipids. Human TLCD1/2 also regulate membrane fluidity by limiting the levels of polyunsaturated fatty acid-containing membrane phospholipids. FLD-1 and TLCD1/2 do not regulate the synthesis of long-chain polyunsaturated fatty acids but rather limit their incorporation into phospholipids. We conclude that inhibition of FLD-1 or TLCD1/2 prevents lipotoxicity by allowing increased levels of membrane phospholipids that contain fluidizing long-chain polyunsaturated fatty acids. Editorial note This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Mario Ruiz
- Department of Chemistry and Molecular BiologyUniversity of GothenburgGothenburgSweden
| | - Rakesh Bodhicharla
- Department of Chemistry and Molecular BiologyUniversity of GothenburgGothenburgSweden
| | - Emma Svensk
- Department of Chemistry and Molecular BiologyUniversity of GothenburgGothenburgSweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular BiologyUniversity of GothenburgGothenburgSweden
| | - Kiran Busayavalasa
- Department of Chemistry and Molecular BiologyUniversity of GothenburgGothenburgSweden
| | - Henrik Palmgren
- Department of Chemistry and Molecular BiologyUniversity of GothenburgGothenburgSweden
- Diabetes Bioscience, Cardiovascular, Renal and Metabolism, IMED Biotech UnitAstraZenecaGothenburgSweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of MedicineUniversity of GothenburgGothenburgSweden
| | - Jan Boren
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of MedicineUniversity of GothenburgGothenburgSweden
| | - Marc Pilon
- Department of Chemistry and Molecular BiologyUniversity of GothenburgGothenburgSweden
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Devkota R, Pilon M. FRAP: A Powerful Method to Evaluate Membrane Fluidity in Caenorhabditis elegans. Bio Protoc 2018; 8:e2913. [PMID: 34395742 DOI: 10.21769/bioprotoc.2913] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/11/2018] [Accepted: 06/12/2018] [Indexed: 11/02/2022] Open
Abstract
FRAP (Fluorescence Recovery After Photobleaching) is probably the most direct method to investigate the dynamics of molecules in living cells. Here, we describe FRAP to quantify membrane fluidity in C. elegans. Using FRAP, we have shown that cold, glucose and exogenous saturated fatty acids can decrease the fluidity of cellular membranes in certain mutants.
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Affiliation(s)
- Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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Devkota R, Svensk E, Ruiz M, Ståhlman M, Borén J, Pilon M. The adiponectin receptor AdipoR2 and its Caenorhabditis elegans homolog PAQR-2 prevent membrane rigidification by exogenous saturated fatty acids. PLoS Genet 2017; 13:e1007004. [PMID: 28886012 PMCID: PMC5607217 DOI: 10.1371/journal.pgen.1007004] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/20/2017] [Accepted: 08/31/2017] [Indexed: 01/03/2023] Open
Abstract
Dietary fatty acids can be incorporated directly into phospholipids. This poses a specific challenge to cellular membranes since their composition, hence properties, could greatly vary with different diets. That vast variations in diets are tolerated therefore implies the existence of regulatory mechanisms that monitor and regulate membrane compositions. Here we show that the adiponectin receptor AdipoR2, and its C. elegans homolog PAQR-2, are essential to counter the membrane rigidifying effects of exogenously provided saturated fatty acids. In particular, we use dietary supplements or mutated E. coli as food, together with direct measurements of membrane fluidity and composition, to show that diets containing a high ratio of saturated to monounsaturated fatty acids cause membrane rigidity and lethality in the paqr-2 mutant. We also show that mammalian cells in which AdipoR2 has been knocked-down by siRNA are unable to prevent the membrane-rigidifying effects of palmitic acid. We conclude that the PAQR-2 and AdipoR2 proteins share an evolutionarily conserved function that maintains membrane fluidity in the presence of exogenous saturated fatty acids.
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Affiliation(s)
- Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Emma Svensk
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
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Svensk E, Biermann J, Hammarsten S, Magnusson F, Pilon M. Leveraging the withered tail tip phenotype in C. elegans to identify proteins that influence membrane properties. Worm 2016; 5:e1206171. [PMID: 27695656 PMCID: PMC5022664 DOI: 10.1080/21624054.2016.1206171] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/13/2016] [Accepted: 06/20/2016] [Indexed: 11/11/2022]
Abstract
The properties of cellular membranes are critical for most cellular functions and are influenced by several parameters including phospholipid composition, integral and peripheral membrane proteins, and environmental conditions such as temperature. We previously showed that the C. elegans paqr-2 and iglr-2 mutants have a defect in membrane homeostasis and exhibit several distinct phenotypes, including a characteristic tail tip defect and cold intolerance. In the present study we report that screening for novel mutants with these 2 defects can lead to the identification of genes that are important contributors to membrane properties. In particular we isolated 3 novel alleles of sma-1, the C. elegans homolog of βH spectrin, and 2 novel alleles of dpy-23, which encodes the C. elegans homolog of the AP2 μ subunit. We also show that sma-1 and dpy-23 act on membrane properties in pathways distinct from that of paqr-2 and iglr-2.
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Affiliation(s)
- Emma Svensk
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg, Sweden
| | - Jana Biermann
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg, Sweden
| | - Sofia Hammarsten
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg, Sweden
| | - Fredrik Magnusson
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg, Sweden
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Svensk E, Devkota R, Ståhlman M, Ranji P, Rauthan M, Magnusson F, Hammarsten S, Johansson M, Borén J, Pilon M. Correction: Caenorhabditis elegans PAQR-2 and IGLR-2 Protect against Glucose Toxicity by Modulating Membrane Lipid Composition. PLoS Genet 2016; 12:e1006112. [PMID: 27257966 PMCID: PMC4892886 DOI: 10.1371/journal.pgen.1006112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Svensk E, Devkota R, Ståhlman M, Ranji P, Rauthan M, Magnusson F, Hammarsten S, Johansson M, Borén J, Pilon M. Caenorhabditis elegans PAQR-2 and IGLR-2 Protect against Glucose Toxicity by Modulating Membrane Lipid Composition. PLoS Genet 2016; 12:e1005982. [PMID: 27082444 PMCID: PMC4833288 DOI: 10.1371/journal.pgen.1005982] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/16/2016] [Indexed: 12/19/2022] Open
Abstract
In spite of the worldwide impact of diabetes on human health, the mechanisms behind glucose toxicity remain elusive. Here we show that C. elegans mutants lacking paqr-2, the worm homolog of the adiponectin receptors AdipoR1/2, or its newly identified functional partner iglr-2, are glucose intolerant and die in the presence of as little as 20 mM glucose. Using FRAP (Fluorescence Recovery After Photobleaching) on living worms, we found that cultivation in the presence of glucose causes a decrease in membrane fluidity in paqr-2 and iglr-2 mutants and that genetic suppressors of this sensitivity act to restore membrane fluidity by promoting fatty acid desaturation. The essential roles of paqr-2 and iglr-2 in the presence of glucose are completely independent from daf-2 and daf-16, the C. elegans homologs of the insulin receptor and its downstream target FoxO, respectively. Using bimolecular fluorescence complementation, we also show that PAQR-2 and IGLR-2 interact on plasma membranes and thus may act together as a fluidity sensor that controls membrane lipid composition.
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Affiliation(s)
- Emma Svensk
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Parmida Ranji
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Manish Rauthan
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Magnusson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Sofia Hammarsten
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Maja Johansson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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Rauthan M, Pilon M. A chemical screen to identify inducers of the mitochondrial unfolded protein response in C. elegans. Worm 2015; 4:e1096490. [PMID: 27123370 PMCID: PMC4826155 DOI: 10.1080/21624054.2015.1096490] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 09/09/2015] [Accepted: 09/15/2015] [Indexed: 01/09/2023]
Abstract
We previously showed that inhibition of the mevalonate pathway in C. elegans causes inhibition of protein prenylation, developmental arrest and lethality. We also showed that constitutive activation of the mitochondrial unfolded protein response, UPRmt, is an effective way for C. elegans to become resistant to the negative effects of mevalonate pathway inhibition. This was an important finding since statins, a drug class prescribed to lower cholesterol levels in patients, act by inhibiting the mevalonate pathway, and it is therefore possible that some of their undesirable side effects could be alleviated by activating the UPRmt. Here, we screened a chemical library and identified 4 compounds that specifically activated the UPRmt. One of these compounds, methacycline hydrochloride (a tetracycline antibiotic) also protected C. elegans and mammalian cells from statin toxicity. Methacycline hydrochloride and ethidium bromide, a known UPRmt activator, were also tested in mice: only ethidium bromide significantly activate the UPRmt in skeletal muscles.
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Affiliation(s)
- Manish Rauthan
- Department of Chemistry and Molecular Biology; University of Gothenburg ; Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology; University of Gothenburg ; Gothenburg, Sweden
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27
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Abstract
Autophagy is a catabolic process in which long-lived proteins and organelles are degraded for recycling in the cytoplasm. In the nematode Caenorhabditis elegans autophagy is associated with formation of the dauer larva, an alternative developmental stage that worms can enter under poor growth conditions. We have shown that C. elegans mutants that experience caloric restriction because they are feeding-defective also exhibit elevated autophagy and decreased levels of fat deposits, as well as smaller cells and, consequently, a smaller body size. Our results suggest novel relationships between caloric restriction, longevity, body size and autophagy.
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Affiliation(s)
- Catarina Mörck
- Department of Cell and Molecular Biology, Göteborg University, Medicinaregatan 9, Göteborg S-405 30, Sweden
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Ranji P, Rauthan M, Pitot C, Pilon M. Loss of HMG-CoA reductase in C. elegans causes defects in protein prenylation and muscle mitochondria. PLoS One 2014; 9:e100033. [PMID: 24918786 PMCID: PMC4053411 DOI: 10.1371/journal.pone.0100033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/21/2014] [Indexed: 01/14/2023] Open
Abstract
HMG-CoA reductase is the rate-limiting enzyme in the mevalonate pathway and the target of cholesterol-lowering statins. We characterized the C. elegans hmgr-1(tm4368) mutant, which lacks HMG-CoA reductase, and show that its phenotypes recapitulate that of statin treatment, though in a more severe form. Specifically, the hmgr-1(tm4368) mutant has defects in growth, reproduction and protein prenylation, is rescued by exogenous mevalonate, exhibits constitutive activation of the UPRer and requires less mevalonate to be healthy when the UPRmt is activated by a constitutively active form of ATFS-1. We also show that different amounts of mevalonate are required for different physiological processes, with reproduction requiring the highest levels. Finally, we provide evidence that the mevalonate pathway is required for the activation of the UPRmt.
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Affiliation(s)
- Parmida Ranji
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Manish Rauthan
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Christophe Pitot
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
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29
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Pilon M. Developmental genetics of the Caenorhabditis elegans pharynx. Wiley Interdiscip Rev Dev Biol 2014; 3:263-80. [PMID: 25262818 PMCID: PMC4314705 DOI: 10.1002/wdev.139] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 04/03/2014] [Accepted: 04/15/2014] [Indexed: 11/07/2022]
Abstract
The Caenorhabditis elegans pharynx is a rhythmically pumping organ composed initially of 80 cells that, through fusions, amount to 62 cells in the adult worm. During the first 100 min of development, most future pharyngeal cells are born and gather into a double-plate primordium surrounded by a basal lamina. All pharyngeal cells express the transcription factor PHA-4, of which the concentration increases throughout development, triggering a sequential activation of genes with promoters responding differentially to PHA-4 protein levels. The oblong-shaped pharyngeal primordium becomes polarized, many cells taking on wedge shapes with their narrow ends toward the center, hence forming an epithelial cyst. The primordium then elongates, and reorientations of the cells at the anterior and posterior ends form the mouth and pharyngeal-intestinal openings, respectively. The 20 pharyngeal neurons establish complex but reproducible trajectories using 'fishing line' and growth cone-driven mechanisms, and the gland cells also similarly develop their processes. The genetics behind many fate decisions and morphogenetic processes are being elucidated, and reveal the pharynx to be a fruitful model for developmental biologists.
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Affiliation(s)
- Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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30
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Pilon M, Svensk E. PAQR-2 may be a regulator of membrane fluidity during cold adaptation. Worm 2013; 2:e27123. [PMID: 24744984 DOI: 10.4161/worm.27123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 11/07/2013] [Indexed: 12/14/2022]
Abstract
PAQR-2 is a C. elegans homolog of the mammalian adiponectin receptors. We have recently shown that PAQR-2 is essential for the ability of C. elegans to grow at its lower temperature range, i.e., 15 °C, and that the likely role of PAQR-2 during cold adaptation is to regulate membrane fluidity by promoting fatty acid desaturation. Here we present a summary of this work, with an emphasis on placing our C. elegans findings in the context of mammalian biology.
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Affiliation(s)
- Marc Pilon
- Department of Chemistry and Molecular Biology; University of Gothenburg; Medicinaregatan 9C; Gothenburg, Sweden
| | - Emma Svensk
- Department of Chemistry and Molecular Biology; University of Gothenburg; Medicinaregatan 9C; Gothenburg, Sweden
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Svensk E, Ståhlman M, Andersson CH, Johansson M, Borén J, Pilon M. PAQR-2 regulates fatty acid desaturation during cold adaptation in C. elegans. PLoS Genet 2013; 9:e1003801. [PMID: 24068966 PMCID: PMC3772066 DOI: 10.1371/journal.pgen.1003801] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 08/01/2013] [Indexed: 01/19/2023] Open
Abstract
C. elegans PAQR-2 is homologous to the insulin-sensitizing adiponectin receptors in mammals, and essential for adaptation to growth at 15°C, a low but usually acceptable temperature for this organism. By screening for novel paqr-2 suppressors, we identified mutations in genes involved in phosphatidylcholine synthesis (cept-1, pcyt-1 and sams-1) and fatty acid metabolism (ech-7, hacd-1, mdt-15, nhr-49 and sbp-1). We then show genetic evidence that paqr-2, phosphatidylcholines, sbp-1 and Δ9-desaturases form a cold adaptation pathway that regulates the increase in unsaturated fatty acids necessary to retain membrane fluidity at low temperatures. This model is supported by the observations that the paqr-2 suppressors normalize the levels of saturated fatty acids, and that low concentrations of detergents that increase membrane fluidity can rescue the paqr-2 mutant. Cold-blooded organisms such as insects, fish or worms must make physiological adjustments when the temperature in their environment decreases. One essential adaptive measure is to increase the fluidity of the cellular membranes that are made of fatty molecules and would tend to harden at low temperatures, just as butter would. In our study we identify genes that are regulated by PAQR-2, a membrane protein that we show to be essential for adjusting the membrane fluidity during cold adaptation in the nematode C. elegans. Interestingly, the genes influenced by PAQR-2 are all involved in fatty acid metabolism. We speculate that the human homologs of PAQR-2, which are receptors for the hormone adiponectin, may have similar functions.
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Affiliation(s)
- Emma Svensk
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Carl-Henrik Andersson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Maja Johansson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
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Abstract
The mevalonate pathway in human is responsible for the synthesis of cholesterol and other important biomolecules such as coenzyme Q, dolichols and isoprenoids. These molecules are required in the cell for functions ranging from signaling to membrane integrity, protein prenylation and glycosylation, and energy homeostasis. The pathway consists of a main trunk followed by sub-branches that synthesize the different biomolecules. The majority of our knowledge about the mevalonate pathway is currently focused on the cholesterol synthesis branch, which is the target of the cholesterol-lowering statins; less is known about the function and regulation of the non-cholesterol-related branches. To study them, we need a biological system where it is possible to specifically modulate these metabolic branches individually or in groups. The nematode Caenorhabditis elegans (C. elegans) is a promising model to study these non-cholesterol branches since its mevalonate pathway seems very well conserved with that in human except that it has no cholesterol synthesis branch. The simple genetic makeup and tractability of C. elegans makes it relatively easy to identify and manipulate key genetic components of the mevalonate pathway, and to evaluate the consequences of tampering with their activity. This general experimental approach should lead to new insights into the physiological roles of the non-cholesterol part of the mevalonate pathway. This review will focus on the current knowledge related to the mevalonate pathway in C. elegans and its possible applications as a model organism to study the non-cholesterol functions of this pathway.
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Affiliation(s)
- Manish Rauthan
- Department of Cell and Molecular Biology, University of Gothenburg, S-405 30 Gothenburg, Sweden
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Mörck C, Vivekanand V, Jafari G, Pilon M. C. elegans ten-1 is synthetic lethal with mutations in cytoskeleton regulators, and enhances many axon guidance defective mutants. BMC Dev Biol 2010; 10:55. [PMID: 20497576 PMCID: PMC2887410 DOI: 10.1186/1471-213x-10-55] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 05/24/2010] [Indexed: 12/24/2022]
Abstract
BACKGROUND Teneurins are transmembrane proteins that assist morphogenetic processes in many organisms. ten-1 is the C. elegans teneurin homolog with two transcripts, ten-1a and ten-1b, that respectively encode a long (TEN-1L) and short (TEN-1S) form of the protein. We previously isolated a C. elegans mutant where one pharyngeal neuron was frequently misplaced, and now show that it corresponds to a novel allele of ten-1. RESULTS The novel ten-1(et5) allele is a hypomorph since its post-embryonic phenotype is weaker than the null alleles ten-1(ok641) and ten-1(tm651). ten-1 mutants have defects in all pharyngeal neurons that we examined, and in vivo reporters show that only the long form of the ten-1 gene is expressed in the pharynx, specifically in six marginal cells and the M2 neurons. Defects in the pharyngeal M2 neurons were enhanced when the ten-1(ok641) mutation was combined with mutations in the following genes: mig-14, unc-5, unc-51, unc-52 and unc-129. None of the body neurons examined show any defects in the ten-1(ok641) mutant, but genetic interaction studies reveal that ten-1(ok641) is synthetic lethal with sax-3, unc-34 and unc-73, and examination of the hypodermal cells in embryos of the ten-1(ok641) mutant point to a role of ten-1 during hypodermal cell morphogenesis. CONCLUSIONS Our results are consistent with ten-1 normally providing a function complementary to the cytoskeletal remodeling processes that occur in migrating cells or cells undergoing morphogenesis. It is possible that ten-1 influences the composition/distribution of extracellular matrix.
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Affiliation(s)
- Catarina Mörck
- Department of Cell and Molecular Biology, University of Gothenburg S-405 30 Gothenburg, Sweden
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34
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Pilon M. Fishing lines, time-delayed guideposts, and other tricks used by developing pharyngeal neurons in Caenorhabditis elegans. Dev Dyn 2008; 237:2073-80. [PMID: 18651660 DOI: 10.1002/dvdy.21636] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The 20 neurons that innervate the Caenorhabditis elegans pharynx form a simple nervous system that develops and operates in near complete isolation from the rest of the worm body and, therefore, offers a manageable degree of complexity for developmental genetics studies. This review discusses the progress that has been made in determining the mechanisms by which 4 of the 20 pharyngeal neurons develop, and emphasizes surprising processes that add to the classic growth cone guidance model which is usually thought to explain how most axons establish their trajectories.
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Affiliation(s)
- Marc Pilon
- Department of Cell Molecular Biology, University of Göteborg, Göteborg, Sweden.
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35
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Pilon M, Mailhot M, Comtois A, Soulieres D, Charpentier D, Letarte N, Moride Y. Evaluation of a protocol algorithm for the treatment of epidermal growth factor receptor inhibitors-induced dermatological side effects (EPIDERM Study). J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.20755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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36
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Axäng C, Rauthan M, Hall DH, Pilon M. Developmental genetics of the C. elegans pharyngeal neurons NSML and NSMR. BMC Dev Biol 2008; 8:38. [PMID: 18400083 PMCID: PMC2375884 DOI: 10.1186/1471-213x-8-38] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 04/09/2008] [Indexed: 01/02/2023]
Abstract
BACKGROUND We are interested in understanding how the twenty neurons of the C. elegans pharynx develop in an intricate yet reproducible way within the narrow confines of the embryonic pharyngeal primordium. To complement an earlier study of the pharyngeal M2 motorneurons, we have now examined the effect of almost forty mutations on the morphology of a bilateral pair of pharyngeal neurosecretory-motor neurons, the NSMs. RESULTS A careful description of the NSM morphology led to the discovery of a third, hitherto unreported process originating from the NSM cell body and that is likely to play a proprioceptive function. We found that the three NSM processes are differently sensitive to mutations. The major dorsal branch was most sensitive to mutations that affect growth cone guidance and function (e.g. unc-6, unc-34, unc-73), while the major sub-ventral branch was more sensitive to mutations that affect components of the extracellular matrix (e.g. sdn-1). Of the tested mutations, only unc-101, which affects an adaptin, caused the loss of the newly described thin minor process. The major processes developed synaptic branches post-embryonically, and these exhibited activity-dependent plasticity. CONCLUSION By studying the effects of nearly forty different mutations we have learned that the different NSM processes require different genes for their proper guidance and use both growth cone dependent and growth cone independent mechanisms for establishing their proper trajectories. The two major NSM processes develop in a growth cone dependent manner, although the sub-ventral process relies more on substrate adhesion. The minor process also uses growth cones but uniquely develops using a mechanism that depends on the clathrin adaptor molecule UNC-101. Together with the guidance of the M2 neuron, this is the second case of a pharyngeal neuron establishing one of its processes using an unexpected mechanism.
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Affiliation(s)
- Claes Axäng
- Dept, Cell and Molecular Biology, Göteborg University, Box 462, S-405 30, Sweden.
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Dias J, Talbot S, Pilon M, Sénécal J, de Champlain J, Couture R. Kinin B1 Receptor as a Therapeutic Target in the Treatment of Diabetes. Can J Diabetes 2008. [DOI: 10.1016/s1499-2671(08)24252-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Molin M, Pilon M, Blomberg A. Dihydroxyacetone-induced death is accompanied by advanced glycation endproduct formation in selected proteins ofSaccharomyces cerevisiaeandCaenorhabditis elegans. Proteomics 2007; 7:3764-74. [PMID: 17890650 DOI: 10.1002/pmic.200700165] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Advanced glycation endproduct (AGE) formation is an important mechanism for protein deterioration during diabetic complications and ageing. The effects on AGE formation following dihydroxyacetone (DHA) stress were studied in two model organisms, the yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans. Total protein AGEs, detected using an anti-N(epsilon)-carboxyalkyllysine-specific monoclonal antibody, displayed a strong correlation to DHA-induced yeast cell mortality in the wild-type and hypersensitive as well as resistant mutant strains. During DHA-induced cell death we also detected AGEs as the formation of acidic protein modifications by 2-D PAGE. Furthermore, we confirmed AGE targets immunologically on 2-D gel-separated protein extracted from DHA-treated cells. AGE modification of several metabolic enzymes (Eno2p, Adh1p, Met6 and Pgk1p) and actin (Act1p) displayed a strong correlation to DHA-induced cell death. DHA was toxic to C. elegans even at low concentration and also in this organism AGE formation accompanied death. We propose the use of DHA as a model AGE-generating substance for its apparent lack of a clear oxidative stress connection, and yeast and worm as model organisms to identify genetic determinants of protein AGE formation.
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Affiliation(s)
- Mikael Molin
- Department of Cell and Molecular Biology, Göteborg University, Göteborg, Sweden
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Hellerer T, Axäng C, Brackmann C, Hillertz P, Pilon M, Enejder A. Monitoring of lipid storage in Caenorhabditis elegans using coherent anti-Stokes Raman scattering (CARS) microscopy. Proc Natl Acad Sci U S A 2007; 104:14658-63. [PMID: 17804796 PMCID: PMC1976189 DOI: 10.1073/pnas.0703594104] [Citation(s) in RCA: 257] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Better understanding of the fundamental mechanisms behind metabolic diseases requires methods to monitor lipid stores on single-cell level in vivo. We have used Caenorhabditis elegans as a model organism to demonstrate the limitations of fluorescence microscopy for imaging of lipids compared with coherent anti-Stokes Raman scattering (CARS) microscopy, the latter allowing chemically specific and label-free imaging in living organisms. CARS microscopy was used to quantitatively monitor the impact of genetic variations in metabolic pathways on lipid storage in 60 specimens of C. elegans. We found that the feeding-defective mutant pha-3 contained a lipid volume fraction one-third of that found in control worms. In contrast, mutants (daf-2, daf-4 dauer) with deficiencies in the insulin and transforming growth factors (IGF and TGF-beta) signaling pathways had lipid volume fractions that were 1.4 and 2 times larger than controls, respectively. This was observed as an accumulation of small-sized lipid droplets in the hypodermal cells, hosting as much as 40% of the total lipid volume in contrast to the 9% for the wild-type larvae. Spectral CARS microscopy measurements indicated that this is accompanied by a shift in the ordering of the lipids from gel to liquid phase. We conclude that the degree of hypodermal lipid storage and the lipid phase can be used as a marker of lipid metabolism shift. This study shows that CARS microscopy has the potential to become a sensitive and important tool for studies of lipid storage mechanisms, improving our understanding of phenomena underlying metabolic disorders.
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Affiliation(s)
- Thomas Hellerer
- *Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Göteborg, Sweden; and
| | - Claes Axäng
- *Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Göteborg, Sweden; and
| | - Christian Brackmann
- *Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Göteborg, Sweden; and
| | - Per Hillertz
- *Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Göteborg, Sweden; and
| | - Marc Pilon
- Göteborg University, Department of Cell and Molecular Biology, SE-405 30 Göteborg, Sweden
| | - Annika Enejder
- *Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Göteborg, Sweden; and
- To whom correspondence should be addressed. E-mail:
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Thi Thu Cuc N, Pilon M. An Aphelenchoides sp. nematode Parasitic of Polianthes tuberosa in the Mekong Delta. J Nematol 2007; 39:248-257. [PMID: 19259495 PMCID: PMC2586507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Indexed: 05/27/2023] Open
Abstract
Polianthes tuberosa is a commercially valuable flower crop in the Mekong Delta of Vietnam that is propagated by the harvesting and planting of bulbs. The cultivation of P. tuberosa is complicated by an endemic nematode infection that damages a high proportion of the plants. Based on morphological criteria and ribosomal RNA gene sequencing, we have determined that the infection is caused by an Aphelenchoides sp. nematode and is most likely Aphelenchoides besseyi. By scoring various parts of harvested plants with flowers for the presence of viable nematodes over a period of six months, we determined that the nematode is an ectoparasite that can survive the intercrop periods, especially in the bulbs that are used to plant new crops. A comparison of farming practices in the Mekong Delta failed to identify useful control methods, but rather indicated that fields that have cultivated P. tuberosa for the longest periods suffer the worst damage from the nematode infection. Finally, we demonstrated that the nematode is capable of infecting 30 rice cultivars but does not cause the white tip disease usually associated with A. besseyi infection.
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Affiliation(s)
- Nguyen Thi Thu Cuc
- Cantho University, College of Agriculture and Applied Biology, Department of Plant Protection, 3/2 street, Can Tho City, Vietnam Department of Cell and Molecular Biology, Göteborg University, S-405 30 Göteborg, Sweden
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Dias JP, Ismael MA, Pilon M, de Champlain J, Ferrari B, Carayon P, Couture R. The kinin B1 receptor antagonist SSR240612 reverses tactile and cold allodynia in an experimental rat model of insulin resistance. Br J Pharmacol 2007; 152:280-7. [PMID: 17618300 PMCID: PMC1978253 DOI: 10.1038/sj.bjp.0707388] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE Diabetes causes sensory polyneuropathy with associated pain in the form of tactile allodynia and thermal hyperalgesia which are often intractable and resistant to current therapy. This study tested the beneficial effects of the non-peptide and orally active kinin B(1) receptor antagonist SSR240612 against tactile and cold allodynia in a rat model of insulin resistance. EXPERIMENTAL APPROACH Rats were fed with 10% D-glucose for 12 weeks and effects of orally administered SSR240612 (0.3-30 mg kg(-1)) were determined on the development of tactile and cold allodynia. Possible interference of SSR240612 with vascular oxidative stress and pancreatic function was also addressed. KEY RESULTS Glucose-fed rats exhibited tactile and cold allodynia, increases in systolic blood pressure and higher plasma levels of insulin and glucose, at 12 weeks. SSR240612 blocked tactile and cold allodynia at 3 h (ID(50)=5.5 and 7.1 mg kg(-1), respectively) in glucose-fed rats but had no effect in control rats. The antagonist (10 mg kg(-1)) had no effect on plasma glucose and insulin, insulin resistance (HOMA index) and aortic superoxide anion production in glucose-fed rats. CONCLUSIONS AND IMPLICATIONS We provide the first evidence that the B(1) receptors are involved in allodynia in an experimental rat model of insulin resistance. Allodynia was alleviated by SSR240612 most likely through a direct inhibition of B(1) receptors affecting spinal cord and/or sensory nerve excitation. Thus, orally active non-peptide B(1) receptor antagonists should have clinical therapeutic potential in the treatment of sensory polyneuropathy.
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Affiliation(s)
- J P Dias
- Department of Physiology, Faculty of Medicine, Université de Montréal Montréal, Québec, Canada
| | - M A Ismael
- Department of Physiology, Faculty of Medicine, Université de Montréal Montréal, Québec, Canada
| | - M Pilon
- Department of Physiology, Faculty of Medicine, Université de Montréal Montréal, Québec, Canada
| | - J de Champlain
- Department of Physiology, Faculty of Medicine, Université de Montréal Montréal, Québec, Canada
| | - B Ferrari
- Sanofi-Aventis R&D Montpellier, France
| | - P Carayon
- Sanofi-Aventis R&D Montpellier, France
| | - R Couture
- Department of Physiology, Faculty of Medicine, Université de Montréal Montréal, Québec, Canada
- Author for correspondence:
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Mörck C, Axäng C, Goksör M, Pilon M. Misexpression of acetylcholinesterases in the C. elegans pha-2 mutant accompanies ultrastructural defects in pharyngeal muscle cells. Dev Biol 2006; 297:446-60. [PMID: 16806153 DOI: 10.1016/j.ydbio.2006.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 05/08/2006] [Accepted: 05/18/2006] [Indexed: 11/24/2022]
Abstract
pha-2 is the Caenorhabditis elegans homolog of the vertebrate homeobox gene Hex. Embryonic expression of pha-2 is mostly pharyngeal and the only described mutant allele of pha-2 results in a severe pharyngeal defect in which certain muscle cells (pm5 cells) and neurons are grossly deformed. Here, we performed a detailed characterization of the pha-2 phenotype using cell-type-specific reporters, physical manipulation of the nuclei in pharyngeal muscle cells using "optical tweezers", electron microscopy, staining of the actin cytoskeleton as well as phenotypic rescue and ectopic expression experiments. The main findings of the present study are (i) the pha-2 (ad472) mutation specifically impairs the pharyngeal expression of pha-2; (ii) in the pha-2 mutant, the cytoskeleton of the pm5 cells is measurably weaker than in normal cells and is severely disrupted by large tubular structures and organelles; (iii) the pm5 cells of the pha-2 mutant fail to express the acetylcholinesterase genes ace-1 and ace-2; (iv) ectopic expression of pha-2 can induce ectopic expression of ace-1 and ace-2; and (v) the anc-1 mutant with mislocalized pm5 cell nuclei occasionally shows an isthmus phenotype similar to that of pha-2 worms.
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Affiliation(s)
- Catarina Mörck
- Department of Cell and Molecular Biology, Göteborg University, Box 462, SE-405 30 Göteborg, Sweden
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Mörck C, Pilon M. C. elegans feeding defective mutants have shorter body lengths and increased autophagy. BMC Dev Biol 2006; 6:39. [PMID: 16884547 PMCID: PMC1559592 DOI: 10.1186/1471-213x-6-39] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 08/03/2006] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mutations that cause feeding defects in the nematode C. elegans are known to increase life span. Here we show that feeding defective mutants also have a second general trait in common, namely that they are small. RESULTS Our measurements of the body lengths of a variety of feeding defective mutants, or of a variety of double mutants affecting other pathways that regulate body length in C. elegans, i.e. the DBL-1/TGFbeta, TAX-6/calcineurin and the SMA-1/betaH-spectrin pathways, indicate that food uptake acts as a separate pathway regulating body length. In early stages, before eating begins, feeding defective worms have no defect in body length or, in some cases, have only slightly smaller body length compared to wild-type. A significant difference in body length is first noticeable at later larval stages, a difference that probably correlates with increasing starvation. We also show that autophagy is induced and that the quantity of fat is decreased in starved worms. CONCLUSION Our results indicate that the long-term starvation seen in feeding-defective C. elegans mutants activates autophagy, and leads to depletion of fat deposits, small cell size and small body size.
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Affiliation(s)
- Catarina Mörck
- Dept. Cell and Molecular Biology, Göteborg University, Box 462, SE-405 30 Göteborg, Sweden
| | - Marc Pilon
- Dept. Cell and Molecular Biology, Göteborg University, Box 462, SE-405 30 Göteborg, Sweden
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Abstract
Mutations in myosin heavy chain (MyHC) genes recently have been shown to be associated with various forms of congenital myopathies: myosin myopathies. The MyHC IIa E706K mutation is associated with congenital joint contractures, early-onset muscle weakness, and progressive course with moderate to severe muscle weakness later in life. To study the pathogenicity of this MyHC mutation, we investigated the effect of the corresponding mutation (E710K) in the major MyHC isoform (MyHC B) of the body wall muscle of the nematode Caenorhabditis elegans. Worms with null mutations in the MyHC B gene (unc-54) are severely paralyzed and depleted of thick filaments in the body wall muscle sarcomeres. unc-54 null mutants with extrachromosomal arrays of a gene construct including the entire wild-type unc-54 gene were partially rescued as determined by a motility assay and by morphological analysis of the body wall muscle. Analysis of unc-54 null mutants with extrachromosomal arrays of the unc-54 gene with the E710K mutation were severely paralyzed but showed formation of thick filaments in the body wall muscle. We conclude that the MyHC E706K (E710K in C. elegans) mutation is pathogenic and that the effect is primarily functional rather than structural because thick filaments are formed. The C. elegans model may be useful to study suspected pathogenic mutations in MyHC genes associated with human muscle diseases.
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Affiliation(s)
- Homa Tajsharghi
- Department of Pathology, Göteborg University, Sahlgrenska Hospital, Göteborg, Sweden.
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Pilon M. The amazing world of nematodes. Trends Parasitol 2005. [DOI: 10.1016/j.pt.2005.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
The Caenorhabditis elegans pharynx is a neuromuscular tube of which the function is to pump and crush bacteria, and inject them into the intestine. The 80-cell pharynx develops via the morphogenesis and differentiation of the cells that compose its semi-spherical primordium, and requires the activity of several evolutionarily conserved genes, such as pha-4 (the homolog to the Drosophila forkhead and vertebrate FoxA), ceh-22 (the homolog to the Drosophila tinman and vertebrate Nkx2.5), and pha-2 (the homolog to the vertebrate Hex). There are 20 neurons in the pharynx, each with a reproducible unique trajectory. Developmental genetic analysis of axon guidance in the pharynx indicates that some axon trajectories are in part established without growth cones, whereas other parts necessitate growth cone function and guidance. Here we provide an overview of the developmental genetics of the Caenorhabditis elegans pharynx, with an emphasis on its nervous system.
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Affiliation(s)
- Marc Pilon
- Lundberg Laboratory, Chalmers University, Göteborg S-405 30, Sweden.
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Mörck C, Rauthan M, Wågberg F, Pilon M. pha-2 encodes the C. elegans ortholog of the homeodomain protein HEX and is required for the formation of the pharyngeal isthmus. Dev Biol 2004; 272:403-18. [PMID: 15282157 DOI: 10.1016/j.ydbio.2004.05.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2004] [Revised: 05/12/2004] [Accepted: 05/14/2004] [Indexed: 11/30/2022]
Abstract
The pha-2 mutant was isolated in 1993 by Leon Avery in a screen for worms with visible defects in pharyngeal feeding behavior. In pha-2 mutant worms, the pharyngeal isthmus is abnormally thick and short and, in contrast to wild-type worms, harbors several cell nuclei. We show here that pha-2 encodes a homeodomain protein and is homologous to the vertebrate homeobox gene, Hex (also known as Prh). Consistent with a function in pharyngeal development, the pha-2 gene is expressed in the pharyngeal primordium of Caenorhabditis elegans embryos, particularly in pm5 cells that form the bulk of the isthmus. We show that in the pha-2 mutant there is a failure of the pm5 cells to elongate anteriorly while keeping their nuclei within the nascent posterior bulb to form the isthmus during the 3-fold embryonic stage. We also present evidence that pha-2 regulates itself positively in pm5 cells, that it is a downstream target of the forkhead gene pha-4, and that it may also act in the isthmus as an inhibitor of the ceh-22 gene, an Nkx2.5 homolog. Finally, we have begun characterizing the regulation of the pha-2 gene and find that intronic sequences are essential for the complete pha-2 expression profile. The present report is the first to examine the expression and function of an invertebrate Hex homolog, that is, the C. elegans pha-2 gene.
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Affiliation(s)
- Catarina Mörck
- Lundberg Laboratory, Chalmers University, Göteborg S-405 30, Sweden
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Abstract
We wish to understand how the trajectories of the twenty pharyngeal neurons of C. elegans are established. In this study we focused on the two bilateral M2 pharyngeal motorneurons, which each have their cell body located in the posterior bulb and send one axon through the isthmus and into the metacorpus. We used a GFP reporter to visualize these neurons in cell-autonomous and cell-non-autonomous axon guidance mutant backgrounds, as well as other mutant classes. Our main findings are: 1). Mutants with impaired growth cone functions, such as unc-6, unc-51, unc-73 and sax-3, often exhibit abnormal terminations and inappropriate trajectories at the distal ends of the M2 axons, i.e. within the metacorpus; and 2). Growth cone function mutants never exhibit abnormalities in the proximal part of the M2 neuron trajectories, i.e. between the cell body and the metacorpus. Our results suggest that the proximal and distal trajectories are established using distinct mechanisms, including a growth cone-independent process to establish the proximal trajectory. We isolated five novel mutants in a screen for worms exhibiting abnormal morphology of the M2 neurons. These mutants define a new gene class designated mnm (M neuron morphology abnormal).
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Affiliation(s)
- Catarina Mörck
- Lundberg Laboratory, Chalmers University, Medicinaregatan 9C, Box 462, S-405 30, Göteborg, Sweden
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Kang D, Pilon M, Weisblat DA. Maternal and zygotic expression of a nanos-class gene in the leech Helobdella robusta: primordial germ cells arise from segmental mesoderm. Dev Biol 2002; 245:28-41. [PMID: 11969253 DOI: 10.1006/dbio.2002.0615] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The nanos-class gene of the leech Helobdella robusta (Hro-nos) is present as a maternal transcript whose levels decay during cleavage; HRO-NOS protein is more abundant in the D quadrant cells relative to the A, B, and C quadrants; and HRO-NOS is more abundant in the ectodermal precursor cell (DNOPQ) than in its sister mesodermal precursor (DM) (Pilon and Weisblat, 1997). Here, using in situ hybridization, we show that Hro-nos mRNA is broadly distributed throughout the zygote, is concentrated in both animal and vegetal teloplasm during stage 1 and is at higher levels in DNOPQ than in DM at stage 4b. Hro-nos expression increases after stage 7, as judged by in situ hybridization, developmental RT-PCR, and western blots; this increase must therefore represent later zygotic expression. Of particular interest, during stages 9 and 10, each of 11 mid-body segments (M8-M18) has a pair of Hro-nos positive "spots" comprising of one or two large cells each. These spots later disappear in an anteroposterior progression. We find that these Hro-nos-expressing cells are of mesodermal origin, arising in a segmentally iterated manner from the M lineage, and correspond to cells previously proposed as primordial germ cells (PGCs; Bürger, 1891; Weisblat and Shankland, 1985). These results support the proposal that nanos-class genes functioned in the specification of germline cells in the ancestral bilaterian and possibly in a separate process related to embryonic polarity in the ancestral protostome.
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Affiliation(s)
- Dongmin Kang
- Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020, USA
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