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Gera J, Kumar D, Chauhan G, Choudhary A, Rani L, Mandal L, Mandal S. High sugar diet-induced fatty acid oxidation potentiates cytokine-dependent cardiac ECM remodeling. J Cell Biol 2024; 223:e202306087. [PMID: 38916917 PMCID: PMC11199913 DOI: 10.1083/jcb.202306087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 03/09/2024] [Accepted: 06/06/2024] [Indexed: 06/26/2024] Open
Abstract
Context-dependent physiological remodeling of the extracellular matrix (ECM) is essential for development and organ homeostasis. On the other hand, consumption of high-caloric diet leverages ECM remodeling to create pathological conditions that impede the functionality of different organs, including the heart. However, the mechanistic basis of high caloric diet-induced ECM remodeling has yet to be elucidated. Employing in vivo molecular genetic analyses in Drosophila, we demonstrate that high dietary sugar triggers ROS-independent activation of JNK signaling to promote fatty acid oxidation (FAO) in the pericardial cells (nephrocytes). An elevated level of FAO, in turn, induces histone acetylation-dependent transcriptional upregulation of the cytokine Unpaired 3 (Upd3). Release of pericardial Upd3 augments fat body-specific expression of the cardiac ECM protein Pericardin, leading to progressive cardiac fibrosis. Importantly, this pathway is quite distinct from the ROS-Ask1-JNK/p38 axis that regulates Upd3 expression under normal physiological conditions. Our results unravel an unknown physiological role of FAO in cytokine-dependent ECM remodeling, bearing implications in diabetic fibrosis.
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Affiliation(s)
- Jayati Gera
- Department of Biological Sciences, Molecular Cell and Developmental Biology Laboratory, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Dheeraj Kumar
- Department of Biological Sciences, Molecular Cell and Developmental Biology Laboratory, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Gunjan Chauhan
- Department of Biological Sciences, Molecular Cell and Developmental Biology Laboratory, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Adarsh Choudhary
- Department of Biological Sciences, Molecular Cell and Developmental Biology Laboratory, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Lavi Rani
- Department of Biological Sciences, Molecular Cell and Developmental Biology Laboratory, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Lolitika Mandal
- Department of Biological Sciences, Developmental Genetics Laboratory, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Sudip Mandal
- Department of Biological Sciences, Molecular Cell and Developmental Biology Laboratory, Indian Institute of Science Education and Research Mohali, Punjab, India
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2
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Dondi C, Vogler G, Gupta A, Walls SM, Kervadec A, Marchant J, Romero MR, Diop S, Goode J, Thomas JB, Colas AR, Bodmer R, Montminy M, Ocorr K. The nutrient sensor CRTC and Sarcalumenin/thinman represent an alternate pathway in cardiac hypertrophy. Cell Rep 2024; 43:114549. [PMID: 39093699 PMCID: PMC11402474 DOI: 10.1016/j.celrep.2024.114549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 05/06/2024] [Accepted: 07/12/2024] [Indexed: 08/04/2024] Open
Abstract
CREB-regulated transcription co-activator (CRTC) is activated by Calcineurin (CaN) to regulate gluconeogenic genes. CaN also has roles in cardiac hypertrophy. Here, we explore a cardiac-autonomous role for CRTC in cardiac hypertrophy. In Drosophila, CRTC mutants exhibit severe cardiac restriction, myofibrillar disorganization, fibrosis, and tachycardia. Cardiac-specific CRTC knockdown (KD) phenocopies mutants, and cardiac overexpression causes hypertrophy. CaN-induced hypertrophy in Drosophila is reduced in CRTC mutants, suggesting that CRTC mediates the effects. RNA sequencing (RNA-seq) of CRTC-KD and -overexpressing hearts reveals contraregulation of metabolic genes. Genes with conserved CREB sites include the fly ortholog of Sarcalumenin, a Ca2+-binding protein. Cardiac manipulation of this gene recapitulates the CRTC-KD and -overexpression phenotypes. CRTC KD in zebrafish also causes cardiac restriction, and CRTC KD in human induced cardiomyocytes causes a reduction in Srl expression and increased action potential duration. Our data from three model systems suggest that CaN-CRTC-Sarcalumenin signaling represents an alternate, conserved pathway underlying cardiac function and hypertrophy.
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Affiliation(s)
- Cristiana Dondi
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Georg Vogler
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Anjali Gupta
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Stanley M Walls
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Anaïs Kervadec
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - James Marchant
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Michaela R Romero
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Soda Diop
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jason Goode
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - John B Thomas
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Alex R Colas
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Marc Montminy
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Karen Ocorr
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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3
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Vieira Contreras F, Auger GM, Müller L, Richter V, Huetteroth W, Seufert F, Hildebrand PW, Scholz N, Thum AS, Ljaschenko D, Blanco-Redondo B, Langenhan T. The adhesion G-protein-coupled receptor mayo/CG11318 controls midgut development in Drosophila. Cell Rep 2024; 43:113640. [PMID: 38180839 DOI: 10.1016/j.celrep.2023.113640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 11/14/2023] [Accepted: 12/16/2023] [Indexed: 01/07/2024] Open
Abstract
Adhesion G-protein-coupled receptors (aGPCRs) form a large family of cell surface molecules with versatile tasks in organ development. Many aGPCRs still await their functional and pharmacological deorphanization. Here, we characterized the orphan aGPCR CG11318/mayo of Drosophila melanogaster and found it expressed in specific regions of the gastrointestinal canal and anal plates, epithelial specializations that control ion homeostasis. Genetic removal of mayo results in tachycardia, which is caused by hyperkalemia of the larval hemolymph. The hyperkalemic effect can be mimicked by a raise in ambient potassium concentration, while normal potassium levels in mayoKO mutants can be restored by pharmacological inhibition of potassium channels. Intriguingly, hyperkalemia and tachycardia are caused non-cell autonomously through mayo-dependent control of enterocyte proliferation in the larval midgut, which is the primary function of this aGPCR. These findings characterize the ancestral aGPCR Mayo as a homeostatic regulator of gut development.
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Affiliation(s)
- Fernando Vieira Contreras
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Genevieve M Auger
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Lena Müller
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Vincent Richter
- Institute of Biology, Department of Genetics, Faculty of Life Sciences, Leipzig University, Talstraße 33, 04103 Leipzig, Germany
| | - Wolf Huetteroth
- Institute of Biology, Department of Genetics, Faculty of Life Sciences, Leipzig University, Talstraße 33, 04103 Leipzig, Germany
| | - Florian Seufert
- Institute for Medical Physics and Biophysics, Medical Faculty, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany
| | - Peter W Hildebrand
- Institute for Medical Physics and Biophysics, Medical Faculty, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany
| | - Nicole Scholz
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Andreas S Thum
- Institute of Biology, Department of Genetics, Faculty of Life Sciences, Leipzig University, Talstraße 33, 04103 Leipzig, Germany
| | - Dmitrij Ljaschenko
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Beatriz Blanco-Redondo
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany.
| | - Tobias Langenhan
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany; Institute of Biology, Faculty of Life Sciences, Leipzig University, Talstraße 33, 04103 Leipzig, Germany; Comprehensive Cancer Center Central Germany (CCCG), Germany.
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4
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Zhu JY, Lee JG, Fu Y, van de Leemput J, Ray PE, Han Z. APOL1-G2 accelerates nephrocyte cell death by inhibiting the autophagy pathway. Dis Model Mech 2023; 16:dmm050223. [PMID: 37969018 PMCID: PMC10765414 DOI: 10.1242/dmm.050223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 10/30/2023] [Indexed: 11/17/2023] Open
Abstract
People of African ancestry who carry the APOL1 risk alleles G1 or G2 are at high risk of developing kidney diseases through not fully understood mechanisms that impair the function of podocytes. It is also not clear whether the APOL1-G1 and APOL1-G2 risk alleles affect these cells through similar mechanisms. Previously, we have developed transgenic Drosophila melanogaster lines expressing either the human APOL1 reference allele (G0) or APOL1-G1 specifically in nephrocytes, the cells homologous to mammalian podocytes. We have found that nephrocytes that expressed the APOL1-G1 risk allele display accelerated cell death, in a manner similar to that of cultured human podocytes and APOL1 transgenic mouse models. Here, to compare how the APOL1-G1 and APOL1-G2 risk alleles affect the structure and function of nephrocytes in vivo, we generated nephrocyte-specific transgenic flies that either expressed the APOL1-G2 or both G1 and G2 (G1G2) risk alleles on the same allele. We found that APOL1-G2- and APOL1-G1G2-expressing nephrocytes developed more severe changes in autophagic pathways, acidification of organelles and the structure of the slit diaphragm, compared to G1-expressing nephrocytes, leading to their premature death. We conclude that both risk alleles affect similar key cell trafficking pathways, leading to reduced autophagy and suggesting new therapeutic targets to prevent APOL1 kidney diseases.
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Affiliation(s)
- Jun-yi Zhu
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jin-Gu Lee
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yulong Fu
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Joyce van de Leemput
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Patricio E. Ray
- Department of Pediatrics, Child Health Research Center, University of Virginia, Charlottesville, VA 22903, USA
| | - Zhe Han
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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5
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Bierzynska A, Bull K, Miellet S, Dean P, Neal C, Colby E, McCarthy HJ, Hegde S, Sinha MD, Bugarin Diz C, Stirrups K, Megy K, Mapeta R, Penkett C, Marsh S, Forrester N, Afzal M, Stark H, BioResource NIHR, Williams M, Welsh GI, Koziell AB, Hartley PS, Saleem MA. Exploring the relevance of NUP93 variants in steroid-resistant nephrotic syndrome using next generation sequencing and a fly kidney model. Pediatr Nephrol 2022; 37:2643-2656. [PMID: 35211795 PMCID: PMC9489583 DOI: 10.1007/s00467-022-05440-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 12/10/2021] [Accepted: 12/21/2021] [Indexed: 10/24/2022]
Abstract
BACKGROUND Variants in genes encoding nuclear pore complex (NPC) proteins are a newly identified cause of paediatric steroid-resistant nephrotic syndrome (SRNS). Recent reports describing NUP93 variants suggest these could be a significant cause of paediatric onset SRNS. We report NUP93 cases in the UK and demonstrate in vivo functional effects of Nup93 depletion in a fly (Drosophila melanogaster) nephrocyte model. METHODS Three hundred thirty-seven paediatric SRNS patients from the National cohort of patients with Nephrotic Syndrome (NephroS) were whole exome and/or whole genome sequenced. Patients were screened for over 70 genes known to be associated with Nephrotic Syndrome (NS). D. melanogaster Nup93 knockdown was achieved by RNA interference using nephrocyte-restricted drivers. RESULTS Six novel homozygous and compound heterozygous NUP93 variants were detected in 3 sporadic and 2 familial paediatric onset SRNS characterised histologically by focal segmental glomerulosclerosis (FSGS) and progressing to kidney failure by 12 months from clinical diagnosis. Silencing of the two orthologs of human NUP93 expressed in D. melanogaster, Nup93-1, and Nup93-2 resulted in significant signal reduction of up to 82% in adult pericardial nephrocytes with concomitant disruption of NPC protein expression. Additionally, nephrocyte morphology was highly abnormal in Nup93-1 and Nup93-2 silenced flies surviving to adulthood. CONCLUSION We expand the spectrum of NUP93 variants detected in paediatric onset SRNS and demonstrate its incidence within a national cohort. Silencing of either D. melanogaster Nup93 ortholog caused a severe nephrocyte phenotype, signaling an important role for the nucleoporin complex in podocyte biology. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Agnieszka Bierzynska
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Katherine Bull
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sara Miellet
- Department of Life and Environmental Science, Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB England, UK
- Illawarra Health and Medical Research Institute, Molecular Horizons and School of Medicine, University of Wollongong, Wollongong, Australia
| | - Philip Dean
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Chris Neal
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Elizabeth Colby
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Hugh J. McCarthy
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
- School of Medicine, University of Sydney and Children’s Hospital at Westmead, Westmead, Australia
| | - Shivaram Hegde
- Children’s Kidney Centre, University Hospital of Wales, Cardiff, UK
| | - Manish D. Sinha
- Department of Paediatric Nephrology, Evelina London Children’s Hospital, Guy’s and St, Thomas’ Hospital, London, UK
| | - Carmen Bugarin Diz
- School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, SE1 7EH UK
| | - Kathleen Stirrups
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Karyn Megy
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Rutendo Mapeta
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Chris Penkett
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Sarah Marsh
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Natalie Forrester
- Illawarra Health and Medical Research Institute, Molecular Horizons and School of Medicine, University of Wollongong, Wollongong, Australia
| | - Maryam Afzal
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Hannah Stark
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - NIHR BioResource
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Maggie Williams
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Gavin I. Welsh
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Ania B. Koziell
- Department of Paediatric Nephrology, Evelina London Children’s Hospital, Guy’s and St, Thomas’ Hospital, London, UK
- School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, SE1 7EH UK
| | - Paul S. Hartley
- Department of Life and Environmental Science, Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB England, UK
| | - Moin A. Saleem
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
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Schroeder AM, Nielsen T, Lynott M, Vogler G, Colas AR, Bodmer R. Nascent polypeptide-Associated Complex and Signal Recognition Particle have cardiac-specific roles in heart development and remodeling. PLoS Genet 2022; 18:e1010448. [PMID: 36240221 PMCID: PMC9604979 DOI: 10.1371/journal.pgen.1010448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 10/26/2022] [Accepted: 09/27/2022] [Indexed: 11/25/2022] Open
Abstract
Establishing a catalog of Congenital Heart Disease (CHD) genes and identifying functional networks would improve our understanding of its oligogenic underpinnings. Our studies identified protein biogenesis cofactors Nascent polypeptide-Associated Complex (NAC) and Signal-Recognition-Particle (SRP) as disease candidates and novel regulators of cardiac differentiation and morphogenesis. Knockdown (KD) of the alpha- (Nacα) or beta-subunit (bicaudal, bic) of NAC in the developing Drosophila heart disrupted cardiac developmental remodeling resulting in a fly with no heart. Heart loss was rescued by combined KD of Nacα with the posterior patterning Hox gene Abd-B. Consistent with a central role for this interaction in cardiogenesis, KD of Nacα in cardiac progenitors derived from human iPSCs impaired cardiac differentiation while co-KD with human HOXC12 and HOXD12 rescued this phenotype. Our data suggest that Nacα KD preprograms cardioblasts in the embryo for abortive remodeling later during metamorphosis, as Nacα KD during translation-intensive larval growth or pupal remodeling only causes moderate heart defects. KD of SRP subunits in the developing fly heart produced phenotypes that targeted specific segments and cell types, again suggesting cardiac-specific and spatially regulated activities. Together, we demonstrated directed function for NAC and SRP in heart development, and that regulation of NAC function depends on Hox genes.
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Affiliation(s)
- Analyne M. Schroeder
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- * E-mail: (AMS); (RB)
| | - Tanja Nielsen
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Michaela Lynott
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Georg Vogler
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Alexandre R. Colas
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- * E-mail: (AMS); (RB)
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7
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Identification and Characterization of UDP-Glycosyltransferase Genes in a Cerambycid Beetle, Pharsalia antennata Gahan, 1894 (Coleoptera: Cerambycidae). DIVERSITY 2022. [DOI: 10.3390/d14050348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The cerambycid beetle, Pharsalia antennata Gahan, 1894 (Coleoptera: Cerambycidae), is a wood-boring pest that spends most of its life cycle in the trunks or under the bark of trees. These distinctive biological characteristics make it likely that this beetle will encounter a number of plant defensive compounds, coupled with a broad range of host plants, possibly resulting in the overexpression or expansion of uridine diphosphate (UDP)-glycosyltransferase (UGT) genes. Here, we identified and characterized the UGT gene family in P. antennata through transcriptome data, sequence and phylogenetic analyses, and PCR and homology modeling approaches. In total, 59 transcripts encoding UGTs were identified, 34 of which harbored full-length sequences and shared high conservation with the UGTs of Anoplophora glabripennis. Of the 34 PantUGTs, only 31.78% amino acid identity was observed on average, but catalytic and sugar binding residues were highly conserved. Phylogenetic analyses revealed four Cerambycidae-specific clades, including 30 members from P. antennata. Combining the transcriptome and PCR data showed that PantUGTs had a wide tissue expression, and the majority of the genes were presented mainly in antennae or abdomens, suggesting their putative roles in olfaction and detoxification. This study provides, for the first time, information on the molecular and genetic basis of P. antennata, greatly enhancing our knowledge of the detoxification-related UGT gene family.
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PI(4,5)P2 controls slit diaphragm formation and endocytosis in Drosophila nephrocytes. Cell Mol Life Sci 2022; 79:248. [PMID: 35437696 PMCID: PMC9016003 DOI: 10.1007/s00018-022-04273-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 03/01/2022] [Accepted: 03/24/2022] [Indexed: 12/03/2022]
Abstract
Drosophila nephrocytes are an emerging model system for mammalian podocytes and proximal tubules as well as for the investigation of kidney diseases. Like podocytes, nephrocytes exhibit characteristics of epithelial cells, but the role of phospholipids in polarization of these cells is yet unclear. In epithelia, phosphatidylinositol(4,5)bisphosphate (PI(4,5)P2) and phosphatidylinositol(3,4,5)-trisphosphate (PI(3,4,5)P3) are asymmetrically distributed in the plasma membrane and determine apical–basal polarity. Here, we demonstrate that both phospholipids are present in the plasma membrane of nephrocytes, but only PI(4,5)P2 accumulates at slit diaphragms. Knockdown of Skittles, a phosphatidylinositol(4)phosphate 5-kinase, which produces PI(4,5)P2, abolished slit diaphragm formation and led to strongly reduced endocytosis. Notably, reduction in PI(3,4,5)P3 by overexpression of PTEN or expression of a dominant-negative phosphatidylinositol-3-kinase did not affect nephrocyte function, whereas enhanced formation of PI(3,4,5)P3 by constitutively active phosphatidylinositol-3-kinase resulted in strong slit diaphragm and endocytosis defects by ectopic activation of the Akt/mTOR pathway. Thus, PI(4,5)P2 but not PI(3,4,5)P3 is essential for slit diaphragm formation and nephrocyte function. However, PI(3,4,5)P3 has to be tightly controlled to ensure nephrocyte development.
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9
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Stern DL. Transgenic tools for targeted chromosome rearrangements allow construction of balancer chromosomes in non- melanogaster Drosophila species. G3 GENES|GENOMES|GENETICS 2022; 12:6526388. [PMID: 35143616 PMCID: PMC8982376 DOI: 10.1093/g3journal/jkac030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/29/2022] [Indexed: 11/13/2022]
Abstract
Abstract
Perhaps the most valuable single set of resources for genetic studies of Drosophila melanogaster is the collection of multiply inverted chromosomes commonly known as balancer chromosomes. Balancers prevent the recovery of recombination exchange products within genomic regions included in inversions and allow perpetual maintenance of deleterious alleles in living stocks and the execution of complex genetic crosses. Balancer chromosomes have been generated traditionally by exposing animals to ionizing radiation and screening for altered chromosome structure or for unusual marker segregation patterns. These approaches are tedious and unpredictable, and have failed to produce the desired products in some species. Here, I describe transgenic tools that allow targeted chromosome rearrangements in Drosophila species. The key new resources are engineered reporter genes containing introns with yeast recombination sites and enhancers that drive fluorescent reporter genes in multiple body regions. These tools were used to generate a doubly inverted chromosome 3R in Drosophila simulans that serves as an effective balancer chromosome.
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Affiliation(s)
- David L Stern
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
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10
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Gera J, Budakoti P, Suhag M, Mandal L, Mandal S. Physiological ROS controls Upd3-dependent modeling of ECM to support cardiac function in Drosophila. SCIENCE ADVANCES 2022; 8:eabj4991. [PMID: 35179958 PMCID: PMC8856619 DOI: 10.1126/sciadv.abj4991] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Despite their highly reactive nature, reactive oxygen species (ROS) at the physiological level serve as signaling molecules regulating diverse biological processes. While ROS usually act autonomously, they also function as local paracrine signals by diffusing out of the cells producing them. Using in vivo molecular genetic analyses in Drosophila, we provide evidence for ROS-dependent paracrine signaling that does not entail ROS release. We show that elevated levels of physiological ROS within the pericardial cells activate a signaling cascade transduced by Ask1, c-Jun N-terminal kinase, and p38 to regulate the expression of the cytokine Unpaired 3 (Upd3). Upd3 released by the pericardial cells controls fat body-specific expression of the extracellular matrix (ECM) protein Pericardin, essential for cardiac function and healthy life span. Therefore, our work reveals an unexpected inter-organ communication circuitry wherein high physiological levels of ROS regulate cytokine-dependent modulation of cardiac ECM with implications in normal and pathophysiological conditions.
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Affiliation(s)
- Jayati Gera
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Punjab 140306, India
| | - Prerna Budakoti
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Punjab 140306, India
| | - Meghna Suhag
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Punjab 140306, India
| | - Lolitika Mandal
- Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Punjab 140306, India
| | - Sudip Mandal
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Punjab 140306, India
- Corresponding author.
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11
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The Pathophysiologic Role of Gelsolin in Chronic Kidney Disease: Focus on Podocytes. Int J Mol Sci 2021; 22:ijms222413281. [PMID: 34948078 PMCID: PMC8704698 DOI: 10.3390/ijms222413281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/28/2021] [Accepted: 12/07/2021] [Indexed: 11/19/2022] Open
Abstract
Chronic kidney disease (CKD) is normally related to proteinuria, a common finding in a compromised glomerular filtration barrier (GFB). GFB is a structure composed of glomerular endothelial cells, the basement membrane, and the podocytes. CKD with podocyte damage may be associated with actin cytoskeleton reorganization, resulting in podocyte effacement. Gelsolin plays a critical role in several diseases, including cardiovascular diseases and cancer. Our current study aimed to determine the connection between gelsolin and podocyte, and thus the mechanism underlying podocyte injury in CKD. Experiments were carried out on Drosophila to demonstrate whether gelsolin had a physiological role in maintaining podocyte. Furthermore, the survival rate of gelsolin-knocked down Drosophila larvae was extensively reduced after AgNO3 exposure. Secondly, the in vitro podocytes treated with puromycin aminonucleoside (PAN) enhanced the gelsolin protein expression, as well as small GTPase RhoA and Rac1, which also regulated actin dynamic expression incrementally with the PAN concentrations. Thirdly, we further demonstrated in vivo that GSN was highly expressed inside the glomeruli with mitochondrial dysfunction in a CKD mouse model. Our findings suggest that an excess of gelsolin may contribute to podocytes damage in glomeruli.
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12
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Boulet M, Renaud Y, Lapraz F, Benmimoun B, Vandel L, Waltzer L. Characterization of the Drosophila Adult Hematopoietic System Reveals a Rare Cell Population With Differentiation and Proliferation Potential. Front Cell Dev Biol 2021; 9:739357. [PMID: 34722521 PMCID: PMC8550105 DOI: 10.3389/fcell.2021.739357] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 09/22/2021] [Indexed: 02/06/2023] Open
Abstract
While many studies have described Drosophila embryonic and larval blood cells, the hematopoietic system of the imago remains poorly characterized and conflicting data have been published concerning adult hematopoiesis. Using a combination of blood cell markers, we show that the adult hematopoietic system is essentially composed of a few distinct mature blood cell types. In addition, our transcriptomics results indicate that adult and larval blood cells have both common and specific features and it appears that adult hemocytes reactivate many genes expressed in embryonic blood cells. Interestingly, we identify a small set of blood cells that does not express differentiation markers but rather maintains the expression of the progenitor marker domeMeso. Yet, we show that these cells are derived from the posterior signaling center, a specialized population of cells present in the larval lymph gland, rather than from larval blood cell progenitors, and that their maintenance depends on the EBF transcription factor Collier. Furthermore, while these cells are normally quiescent, we find that some of them can differentiate and proliferate in response to bacterial infection. In sum, our results indicate that adult flies harbor a small population of specialized cells with limited hematopoietic potential and further support the idea that no substantial hematopoiesis takes place during adulthood.
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Affiliation(s)
- Manon Boulet
- Université Clermont Auvergne, Centre National de la Recherche Scientifique, Institut National de la Sante et de la Recherche Medicale, Institut Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Yoan Renaud
- Université Clermont Auvergne, Centre National de la Recherche Scientifique, Institut National de la Sante et de la Recherche Medicale, Institut Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - François Lapraz
- Centre de Biologie du Développement, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Billel Benmimoun
- Centre de Biologie du Développement, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Laurence Vandel
- Université Clermont Auvergne, Centre National de la Recherche Scientifique, Institut National de la Sante et de la Recherche Medicale, Institut Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Lucas Waltzer
- Université Clermont Auvergne, Centre National de la Recherche Scientifique, Institut National de la Sante et de la Recherche Medicale, Institut Génétique Reproduction et Développement, Clermont-Ferrand, France.,Centre de Biologie du Développement, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
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13
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Mysh M, Poulton JS. The Basolateral Polarity Module Promotes Slit Diaphragm Formation in Drosophila Nephrocytes, a Model of Vertebrate Podocytes. J Am Soc Nephrol 2021; 32:1409-1424. [PMID: 33795424 PMCID: PMC8259641 DOI: 10.1681/asn.2020071050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/12/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Podocyte slit diaphragms (SDs) are intercellular junctions that function as size-selective filters, excluding most proteins from urine. Abnormalities in SDs cause proteinuria and nephrotic syndrome. Podocytes exhibit apicobasal polarity, which can affect fundamental aspects of cell biology, including morphology, intercellular junction formation, and asymmetric protein distribution along the plasma membrane. Apical polarity protein mutations cause nephrotic syndrome, and data suggest apical polarity proteins regulate SD formation. However, there is no evidence that basolateral polarity proteins regulate SDs. Thus, the role of apicobasal polarity in podocytes remains unclear. METHODS Genetic manipulations and transgenic reporters determined the effects of disrupting apicobasal polarity proteins in Drosophila nephrocytes, which have SDs similar to those of mammalian podocytes. Confocal and electron microscopy were used to characterize SD integrity after loss of basolateral polarity proteins, and genetic-interaction studies illuminated relationships among apicobasal polarity proteins. RESULTS The study identified four novel regulators of nephrocyte SDs: Dlg, Lgl, Scrib, and Par-1. These proteins comprise the basolateral polarity module and its effector kinase. The data suggest these proteins work together, with apical polarity proteins, to regulate SDs by promoting normal endocytosis and trafficking of SD proteins. CONCLUSIONS Given the recognized importance of apical polarity proteins and SD protein trafficking in podocytopathies, the findings connecting basolateral polarity proteins to these processes significantly advance our understanding of SD regulation.
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Affiliation(s)
- Michael Mysh
- Department of Biology, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - John S. Poulton
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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14
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Lubojemska A, Stefana MI, Sorge S, Bailey AP, Lampe L, Yoshimura A, Burrell A, Collinson L, Gould AP. Adipose triglyceride lipase protects renal cell endocytosis in a Drosophila dietary model of chronic kidney disease. PLoS Biol 2021; 19:e3001230. [PMID: 33945525 PMCID: PMC8121332 DOI: 10.1371/journal.pbio.3001230] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 05/14/2021] [Accepted: 04/13/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity-related renal lipotoxicity and chronic kidney disease (CKD) are prevalent pathologies with complex aetiologies. One hallmark of renal lipotoxicity is the ectopic accumulation of lipid droplets in kidney podocytes and in proximal tubule cells. Renal lipid droplets are observed in human CKD patients and in high-fat diet (HFD) rodent models, but their precise role remains unclear. Here, we establish a HFD model in Drosophila that recapitulates renal lipid droplets and several other aspects of mammalian CKD. Cell type-specific genetic manipulations show that lipid can overflow from adipose tissue and is taken up by renal cells called nephrocytes. A HFD drives nephrocyte lipid uptake via the multiligand receptor Cubilin (Cubn), leading to the ectopic accumulation of lipid droplets. These nephrocyte lipid droplets correlate with endoplasmic reticulum (ER) and mitochondrial deficits, as well as with impaired macromolecular endocytosis, a key conserved function of renal cells. Nephrocyte knockdown of diglyceride acyltransferase 1 (DGAT1), overexpression of adipose triglyceride lipase (ATGL), and epistasis tests together reveal that fatty acid flux through the lipid droplet triglyceride compartment protects the ER, mitochondria, and endocytosis of renal cells. Strikingly, boosting nephrocyte expression of the lipid droplet resident enzyme ATGL is sufficient to rescue HFD-induced defects in renal endocytosis. Moreover, endocytic rescue requires a conserved mitochondrial regulator, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC1α). This study demonstrates that lipid droplet lipolysis counteracts the harmful effects of a HFD via a mitochondrial pathway that protects renal endocytosis. It also provides a genetic strategy for determining whether lipid droplets in different biological contexts function primarily to release beneficial or to sequester toxic lipids.
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Affiliation(s)
- Aleksandra Lubojemska
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - M. Irina Stefana
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Sebastian Sorge
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Andrew P. Bailey
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lena Lampe
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Azumi Yoshimura
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Alana Burrell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Alex P. Gould
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
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15
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Ahn SJ, Marygold SJ. The UDP-Glycosyltransferase Family in Drosophila melanogaster: Nomenclature Update, Gene Expression and Phylogenetic Analysis. Front Physiol 2021; 12:648481. [PMID: 33815151 PMCID: PMC8010143 DOI: 10.3389/fphys.2021.648481] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/22/2021] [Indexed: 12/15/2022] Open
Abstract
UDP-glycosyltransferases (UGTs) are important conjugation enzymes found in all kingdoms of life, catalyzing a sugar conjugation with small lipophilic compounds and playing a crucial role in detoxification and homeostasis. The UGT gene family is defined by a signature motif in the C-terminal domain where the uridine diphosphate (UDP)-sugar donor binds. UGTs have been identified in a number of insect genomes over the last decade and much progress has been achieved in characterizing their expression patterns and molecular functions. Here, we present an update of the complete repertoire of UGT genes in Drosophila melanogaster and provide a brief overview of the latest research in this model insect. A total of 35 UGT genes are found in the D. melanogaster genome, localized to chromosomes 2 and 3 with a high degree of gene duplications on the chromosome arm 3R. All D. melanogaster UGT genes have now been named in FlyBase according to the unified UGT nomenclature guidelines. A phylogenetic analysis of UGT genes shows lineage-specific gene duplications. Analysis of anatomical and induced gene expression patterns demonstrate that some UGT genes are differentially expressed in various tissues or after environmental treatments. Extended searches of UGT orthologs from 18 additional Drosophila species reveal a diversity of UGT gene numbers and composition. The roles of Drosophila UGTs identified to date are briefly reviewed, and include xenobiotic metabolism, nicotine resistance, olfaction, cold tolerance, sclerotization, pigmentation, and immunity. Together, the updated genomic information and research overview provided herein will aid further research in this developing field.
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Affiliation(s)
- Seung-Joon Ahn
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Steven J Marygold
- FlyBase, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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16
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Lim HY, Bao H, Liu Y, Wang W. Select Septate Junction Proteins Direct ROS-Mediated Paracrine Regulation of Drosophila Cardiac Function. Cell Rep 2020; 28:1455-1470.e4. [PMID: 31390561 DOI: 10.1016/j.celrep.2019.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 04/18/2019] [Accepted: 06/27/2019] [Indexed: 12/27/2022] Open
Abstract
Septate junction (SJ) complex proteins act in unison to provide a paracellular barrier and maintain structural integrity. Here, we identify a non-barrier role of two individual SJ proteins, Coracle (Cora) and Kune-kune (Kune). Reactive oxygen species (ROS)-p38 MAPK signaling in non-myocytic pericardial cells (PCs) is important for maintaining normal cardiac physiology in Drosophila. However, the underlying mechanisms remain unknown. We find that in PCs, Cora and Kune are altered in abundance in response to manipulations of ROS-p38 signaling. Genetic analyses establish Cora and Kune as key effectors of ROS-p38 signaling in PCs on proper heart function. We further determine that Cora regulates normal Kune levels in PCs, which in turn modulates normal Kune levels in the cardiomyocytes essential for proper heart function. Our results thereby reveal select SJ proteins Cora and Kune as signaling mediators of the PC-derived ROS regulation of cardiac physiology.
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Affiliation(s)
- Hui-Ying Lim
- Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, OK, USA.
| | - Hong Bao
- Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Ying Liu
- Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Weidong Wang
- Department of Medicine, Section of Endocrinology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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17
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Modeling Podocyte Biology Using Drosophila Nephrocytes. Methods Mol Biol 2019. [PMID: 31701442 DOI: 10.1007/978-1-4939-9841-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Vertebrate podocytes are kidney glomerular cells critically required for normal renal filtration. To fulfill their role, podocytes form molecular sieves known as slit diaphragms that contribute to the glomerular filtration barrier. The disruption of podocyte biology or slit diaphragm formation in humans is a precursor to albuminuria, renal failure, and cardiovascular morbidity. Due to genetic and functional similarities, the nephrocytes of Drosophila are increasingly used to model the genetic and metabolic basis of human podocyte biology. They have the advantage that they are a much quicker system to study compared to other murine transgenic models. In this chapter we present methods to modulate and study Drosophila nephrocyte function and diaphragm formation.
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18
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Kawasaki Y, Matsumoto A, Miyaki T, Kinoshita M, Kakuta S, Sakai T, Ichimura K. Three-dimensional architecture of pericardial nephrocytes in Drosophila melanogaster revealed by FIB/SEM tomography. Cell Tissue Res 2019; 378:289-300. [PMID: 31089884 DOI: 10.1007/s00441-019-03037-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/15/2019] [Indexed: 01/07/2023]
Abstract
Nephrocytes are similar in structure to podocytes and play a role in the isolation of toxic substances from hemolymph in insects. Drosophila melanogaster nephrocytes have recently been used to study podocyte function and disease. However, the three-dimensional ultrastructure of nephrocytes is not clearly understood because their surrounding basement membrane makes it difficult to observe using conventional scanning electron microscopy. We reconstructed the three-dimensional ultrastructure of Drosophila pericardial nephrocytes using serial focused-ion beam/scanning electron microscopy (FIB/SEM) images. The basal surfaces were occupied by foot processes and slit-like spaces between them. The slit-like spaces corresponded to the podocyte filtration slits and were formed by longitudinal infolding/invagination of the basal plasma membrane. The basal surface between the slit-like spaces became the foot processes, which ran almost linearly, and had a "washboard-like" appearance. Both ends of the foot processes were usually anastomosed to neighboring foot processes and thus free ends were rarely observed. We demonstrated that FIB/SEM is a powerful tool to better understand the three-dimensional architecture of nephrocytes.
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Affiliation(s)
- Yuto Kawasaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Akira Matsumoto
- Department of Biology, Juntendo University School of Medicine, Inzai, Chiba, Japan
| | - Takayuki Miyaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Mui Kinoshita
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Soichiro Kakuta
- Laboratory of Morphology and Image Analysis, Center for Biomedical Research Resources, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tatsuo Sakai
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Koichiro Ichimura
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan. .,Laboratory of Morphology and Image Analysis, Center for Biomedical Research Resources, Juntendo University Graduate School of Medicine, Tokyo, Japan.
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19
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Odenthal J, Brinkkoetter PT. Drosophila melanogaster and its nephrocytes: A versatile model for glomerular research. Methods Cell Biol 2019; 154:217-240. [PMID: 31493819 DOI: 10.1016/bs.mcb.2019.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Glomerular disorders are a predominant cause of chronic kidney diseases and end-stage renal failure. Especially podocytes, epithelial cells which represent the outermost part of the filtration barrier, are affected by disease and experience a gradual loss of function. Despite recent advances in identifying potential pathways underlying podocyte injury, treatment remains challenging. It is therefore desirable to employ suitable model organisms in order to study glomerular disease and elucidate affected pathways. Due to its diverse ways of genetic manipulation and high genomic conservation, Drosophila melanogaster is a powerful model organism for biomedical research. The fly was recently used to assess podocytopathies by exploiting the nephrocyte system. Nephrocytes are spherical cells within the body cavity of the fly responsible for detoxification and clearance of unwanted substances. More importantly, they share many characteristics with mammalian podocytes. Here, we summarize how to use Drosophila as a model organism for podocyte research. We discuss examples of techniques that can be used to genetically manipulate nephrocytes and provide protocols for nephrocyte isolation and for morphological as well as functional analysis.
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Affiliation(s)
- Johanna Odenthal
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; CECAD, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Paul Thomas Brinkkoetter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; CECAD, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
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20
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Headcase is a Repressor of Lamellocyte Fate in Drosophila melanogaster. Genes (Basel) 2019; 10:genes10030173. [PMID: 30841641 PMCID: PMC6470581 DOI: 10.3390/genes10030173] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 01/12/2023] Open
Abstract
Due to the evolutionary conservation of the regulation of hematopoiesis, Drosophila provides an excellent model organism to study blood cell differentiation and hematopoietic stem cell (HSC) maintenance. The larvae of Drosophila melanogaster respond to immune induction with the production of special effector blood cells, the lamellocytes, which encapsulate and subsequently kill the invader. Lamellocytes differentiate as a result of a concerted action of all three hematopoietic compartments of the larva: the lymph gland, the circulating hemocytes, and the sessile tissue. Within the lymph gland, the communication of the functional zones, the maintenance of HSC fate, and the differentiation of effector blood cells are regulated by a complex network of signaling pathways. Applying gene conversion, mutational analysis, and a candidate based genetic interaction screen, we investigated the role of Headcase (Hdc), the homolog of the tumor suppressor HECA in the hematopoiesis of Drosophila. We found that naive loss-of-function hdc mutant larvae produce lamellocytes, showing that Hdc has a repressive role in effector blood cell differentiation. We demonstrate that hdc genetically interacts with the Hedgehog and the Decapentaplegic pathways in the hematopoietic niche of the lymph gland. By adding further details to the model of blood cell fate regulation in the lymph gland of the larva, our findings contribute to the better understanding of HSC maintenance.
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21
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Banerjee U, Girard JR, Goins LM, Spratford CM. Drosophila as a Genetic Model for Hematopoiesis. Genetics 2019; 211:367-417. [PMID: 30733377 PMCID: PMC6366919 DOI: 10.1534/genetics.118.300223] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/05/2018] [Indexed: 12/17/2022] Open
Abstract
In this FlyBook chapter, we present a survey of the current literature on the development of the hematopoietic system in Drosophila The Drosophila blood system consists entirely of cells that function in innate immunity, tissue integrity, wound healing, and various forms of stress response, and are therefore functionally similar to myeloid cells in mammals. The primary cell types are specialized for phagocytic, melanization, and encapsulation functions. As in mammalian systems, multiple sites of hematopoiesis are evident in Drosophila and the mechanisms involved in this process employ many of the same molecular strategies that exemplify blood development in humans. Drosophila blood progenitors respond to internal and external stress by coopting developmental pathways that involve both local and systemic signals. An important goal of these Drosophila studies is to develop the tools and mechanisms critical to further our understanding of human hematopoiesis during homeostasis and dysfunction.
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Affiliation(s)
- Utpal Banerjee
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095
- Molecular Biology Institute, University of California, Los Angeles, California 90095
- Department of Biological Chemistry, University of California, Los Angeles, California 90095
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, California 90095
| | - Juliet R Girard
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095
| | - Lauren M Goins
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095
| | - Carrie M Spratford
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095
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22
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Vaughan L, Marley R, Miellet S, Hartley PS. The impact of SPARC on age-related cardiac dysfunction and fibrosis in Drosophila. Exp Gerontol 2018; 109:59-66. [PMID: 29032244 PMCID: PMC6094046 DOI: 10.1016/j.exger.2017.10.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/17/2017] [Accepted: 10/11/2017] [Indexed: 12/17/2022]
Abstract
Tissue fibrosis, an accumulation of extracellular matrix proteins such as collagen, accompanies cardiac ageing in humans and this is linked to an increased risk of cardiac failure. The mechanisms driving age-related tissue fibrosis and cardiac dysfunction are unclear, yet clinically important. Drosophila is amenable to the study of cardiac ageing as well as collagen deposition; however it is unclear whether collagen accumulates in the ageing Drosophila heart. This work examined collagen deposition and cardiac function in ageing Drosophila, in the context of reduced expression of collagen-interacting protein SPARC (Secreted Protein Acidic and Rich in Cysteine) an evolutionarily conserved protein linked with fibrosis. Heart function was measured using high frame rate videomicroscopy. Collagen deposition was monitored using a fluorescently-tagged collagen IV reporter (encoded by the Viking gene) and staining of the cardiac collagen, Pericardin. The Drosophila heart accumulated collagen IV and Pericardin as flies aged. Associated with this was a decline in cardiac function. SPARC heterozygous flies lived longer than controls and showed little to no age-related cardiac dysfunction. As flies of both genotypes aged, cardiac levels of collagen IV (Viking) and Pericardin increased similarly. Over-expression of SPARC caused cardiomyopathy and increased Pericardin deposition. The findings demonstrate that, like humans, the Drosophila heart develops a fibrosis-like phenotype as it ages. Although having no gross impact on collagen accumulation, reduced SPARC expression extended Drosophila lifespan and cardiac health span. It is proposed that cardiac fibrosis in humans may develop due to the activation of conserved mechanisms and that SPARC may mediate cardiac ageing by mechanisms more subtle than gross accumulation of collagen.
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Affiliation(s)
- Leigh Vaughan
- Bournemouth University, Department of Life and Environmental Science, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB, UK
| | - Richard Marley
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8QQ, UK
| | - Sara Miellet
- Bournemouth University, Department of Life and Environmental Science, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB, UK
| | - Paul S Hartley
- Bournemouth University, Department of Life and Environmental Science, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB, UK.
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23
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Bazzi W, Cattenoz PB, Delaporte C, Dasari V, Sakr R, Yuasa Y, Giangrande A. Embryonic hematopoiesis modulates the inflammatory response and larval hematopoiesis in Drosophila. eLife 2018; 7:e34890. [PMID: 29992900 PMCID: PMC6040882 DOI: 10.7554/elife.34890] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 06/18/2018] [Indexed: 11/25/2022] Open
Abstract
Recent lineage tracing analyses have significantly improved our understanding of immune system development and highlighted the importance of the different hematopoietic waves. The current challenge is to understand whether these waves interact and whether this affects the function of the immune system. Here we report a molecular pathway regulating the immune response and involving the communication between embryonic and larval hematopoietic waves in Drosophila. Down-regulating the transcription factor Gcm specific to embryonic hematopoiesis enhances the larval phenotypes induced by over-expressing the pro-inflammatory Jak/Stat pathway or by wasp infestation. Gcm works by modulating the transduction of the Upd cytokines to the site of larval hematopoiesis and hence the response to chronic (Jak/Stat over-expression) and acute (wasp infestation) immune challenges. Thus, homeostatic interactions control the function of the immune system in physiology and pathology. Our data also indicate that a transiently expressed developmental pathway has a long-lasting effect on the immune response.
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Affiliation(s)
- Wael Bazzi
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
- UMR7104Centre National de la Recherche ScientifiqueIllkirchFrance
- U1258Institut National de la Santé et de la Recherche MédicaleIllkirchFrance
- Université de StrasbourgIllkirchFrance
| | - Pierre B Cattenoz
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
- UMR7104Centre National de la Recherche ScientifiqueIllkirchFrance
- U1258Institut National de la Santé et de la Recherche MédicaleIllkirchFrance
- Université de StrasbourgIllkirchFrance
| | - Claude Delaporte
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
- UMR7104Centre National de la Recherche ScientifiqueIllkirchFrance
- U1258Institut National de la Santé et de la Recherche MédicaleIllkirchFrance
- Université de StrasbourgIllkirchFrance
| | - Vasanthi Dasari
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
- UMR7104Centre National de la Recherche ScientifiqueIllkirchFrance
- U1258Institut National de la Santé et de la Recherche MédicaleIllkirchFrance
- Université de StrasbourgIllkirchFrance
| | - Rosy Sakr
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
- UMR7104Centre National de la Recherche ScientifiqueIllkirchFrance
- U1258Institut National de la Santé et de la Recherche MédicaleIllkirchFrance
- Université de StrasbourgIllkirchFrance
| | - Yoshihiro Yuasa
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
- UMR7104Centre National de la Recherche ScientifiqueIllkirchFrance
- U1258Institut National de la Santé et de la Recherche MédicaleIllkirchFrance
- Université de StrasbourgIllkirchFrance
| | - Angela Giangrande
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
- UMR7104Centre National de la Recherche ScientifiqueIllkirchFrance
- U1258Institut National de la Santé et de la Recherche MédicaleIllkirchFrance
- Université de StrasbourgIllkirchFrance
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24
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Drosophila pericardial nephrocyte ultrastructure changes during ageing. Mech Ageing Dev 2018; 173:9-20. [DOI: 10.1016/j.mad.2018.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/17/2018] [Accepted: 04/23/2018] [Indexed: 10/17/2022]
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Abstract
Excess adipose fat accumulation, or obesity, is a growing problem worldwide in terms of both the rate of incidence and the severity of obesity-associated metabolic disease. Adipose tissue evolved in animals as a specialized dynamic lipid storage depot: adipose cells synthesize fat (a process called lipogenesis) when energy is plentiful and mobilize stored fat (a process called lipolysis) when energy is needed. When a disruption of lipid homeostasis favors increased fat synthesis and storage with little turnover owing to genetic predisposition, overnutrition or sedentary living, complications such as diabetes and cardiovascular disease are more likely to arise. The vinegar fly Drosophila melanogaster (Diptera: Drosophilidae) is used as a model to better understand the mechanisms governing fat metabolism and distribution. Flies offer a wealth of paradigms with which to study the regulation and physiological effects of fat accumulation. Obese flies accumulate triacylglycerols in the fat body, an organ similar to mammalian adipose tissue, which specializes in lipid storage and catabolism. Discoveries in Drosophila have ranged from endocrine hormones that control obesity to subcellular mechanisms that regulate lipogenesis and lipolysis, many of which are evolutionarily conserved. Furthermore, obese flies exhibit pathophysiological complications, including hyperglycemia, reduced longevity and cardiovascular function - similar to those observed in obese humans. Here, we review some of the salient features of the fly that enable researchers to study the contributions of feeding, absorption, distribution and the metabolism of lipids to systemic physiology.
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Affiliation(s)
- Laura Palanker Musselman
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, NY 13902, USA
| | - Ronald P Kühnlein
- Department of Biochemistry 1, Institute of Molecular Biosciences, University of Graz, Humboldtstraβe 50/II, A-8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
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26
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Del Signore SJ, Biber SA, Lehmann KS, Heimler SR, Rosenfeld BH, Eskin TL, Sweeney ST, Rodal AA. dOCRL maintains immune cell quiescence by regulating endosomal traffic. PLoS Genet 2017; 13:e1007052. [PMID: 29028801 PMCID: PMC5656325 DOI: 10.1371/journal.pgen.1007052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 10/25/2017] [Accepted: 10/04/2017] [Indexed: 01/07/2023] Open
Abstract
Lowe Syndrome is a developmental disorder characterized by eye, kidney, and neurological pathologies, and is caused by mutations in the phosphatidylinositol-5-phosphatase OCRL. OCRL plays diverse roles in endocytic and endolysosomal trafficking, cytokinesis, and ciliogenesis, but it is unclear which of these cellular functions underlie specific patient symptoms. Here, we show that mutation of Drosophila OCRL causes cell-autonomous activation of hemocytes, which are macrophage-like cells of the innate immune system. Among many cell biological defects that we identified in docrl mutant hemocytes, we pinpointed the cause of innate immune cell activation to reduced Rab11-dependent recycling traffic and concomitantly increased Rab7-dependent late endosome traffic. Loss of docrl amplifies multiple immune-relevant signals, including Toll, Jun kinase, and STAT, and leads to Rab11-sensitive mis-sorting and excessive secretion of the Toll ligand Spåtzle. Thus, docrl regulation of endosomal traffic maintains hemocytes in a poised, but quiescent state, suggesting mechanisms by which endosomal misregulation of signaling may contribute to symptoms of Lowe syndrome. Lowe syndrome is a developmental disorder characterized by severe kidney, eye, and neurological symptoms, and is caused by mutations in the gene OCRL. OCRL has been shown to control many steps of packaging and transport of materials within cells, though it remains unclear which of these disrupted transport steps cause each of the many symptoms in Lowe syndrome patients. We found that in fruit flies, loss of OCRL caused transport defects at specific internal compartments in innate immune cells, resulting in amplification of multiple critical inflammatory signals. Similar inflammatory signals have been implicated in forms of epilepsy, which is a primary symptom in Lowe syndrome patients. Thus, our work uncovers a new function for OCRL in animals, and opens an exciting new avenue of investigation into how loss of OCRL causes the symptoms of Lowe syndrome.
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Affiliation(s)
- Steven J. Del Signore
- Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Sarah A. Biber
- Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Katherine S. Lehmann
- Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Stephanie R. Heimler
- Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Benjamin H. Rosenfeld
- Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Tania L. Eskin
- Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Sean T. Sweeney
- Department of Biology, University of York, York, United Kingdom
| | - Avital A. Rodal
- Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
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27
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Zhu JY, Fu Y, Richman A, Zhao Z, Ray PE, Han Z. A Personalized Model of COQ2 Nephropathy Rescued by the Wild-Type COQ2 Allele or Dietary Coenzyme Q 10 Supplementation. J Am Soc Nephrol 2017; 28:2607-2617. [PMID: 28428331 DOI: 10.1681/asn.2016060626] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 03/09/2017] [Indexed: 12/26/2022] Open
Abstract
Clinical studies have identified patients with nephrotic syndrome caused by mutations in genes involved in the biosynthesis of coenzyme Q10 (CoQ10), a lipid component of the mitochondrial electron transport chain and an important antioxidant. However, the cellular mechanisms through which these mutations induce podocyte injury remain obscure. Here, we exploited the striking similarities between Drosophila nephrocytes and human podocytes to develop a Drosophila model of these renal diseases, and performed a systematic in vivo analysis assessing the role of CoQ10 pathway genes in renal function. Nephrocyte-specific silencing of Coq2, Coq6, and Coq8, which are genes involved in the CoQ10 pathway that have been associated with genetic nephrotic syndrome in humans, induced dramatic adverse changes in these cells. In particular, silencing of Coq2 led to an abnormal localization of slit diaphragms, collapse of lacunar channels, and more dysmorphic mitochondria. In addition, Coq2-deficient nephrocytes showed elevated levels of autophagy and mitophagy, increased levels of reactive oxygen species, and increased sensitivity to oxidative stress. Dietary supplementation with CoQ10 at least partially rescued these defects. Furthermore, expressing the wild-type human COQ2 gene specifically in nephrocytes rescued the defective protein uptake, but expressing the mutant allele derived from a patient with COQ2 nephropathy did not. We conclude that transgenic Drosophila lines carrying mutations in the CoQ10 pathway genes are clinically relevant models with which to explore the pathogenesis of podocyte injury and could serve as a new platform to test novel therapeutic approaches.
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Affiliation(s)
- Jun-Yi Zhu
- Centers for Cancer and Immunology Research and
| | - Yulong Fu
- Centers for Cancer and Immunology Research and
| | | | - Zhanzheng Zhao
- Department of Nephrology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China; and
| | - Patricio E Ray
- Genetic Medicine Research, Children's National Health System, Washington, DC.,Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Zhe Han
- Centers for Cancer and Immunology Research and .,Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, DC
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28
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Helmstädter M, Huber TB, Hermle T. Using the Drosophila Nephrocyte to Model Podocyte Function and Disease. Front Pediatr 2017; 5:262. [PMID: 29270398 PMCID: PMC5725439 DOI: 10.3389/fped.2017.00262] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 11/24/2017] [Indexed: 12/19/2022] Open
Abstract
Glomerular disorders are a major cause of end-stage renal disease and effective therapies are often lacking. Nephrocytes are considered to be part of the Drosophila excretory system and form slit diaphragms across cellular membrane invaginations. Nehphrocytes have been shown to share functional, morphological, and molecular features with podocytes, which form the glomerular filter in vertebrates. Here, we report the progress and the evolving tool-set of this model system. Combining a functional, accessible slit diaphragm with the power of the genetic tool-kit in Drosophila, the nephrocyte has the potential to greatly advance our understanding of the glomerular filtration barrier in health and disease.
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Affiliation(s)
- Martin Helmstädter
- Renal Division, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias Hermle
- Renal Division, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
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29
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Hartley PS, Motamedchaboki K, Bodmer R, Ocorr K. SPARC-Dependent Cardiomyopathy in Drosophila. ACTA ACUST UNITED AC 2016; 9:119-29. [PMID: 26839388 PMCID: PMC4838489 DOI: 10.1161/circgenetics.115.001254] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 01/27/2016] [Indexed: 12/17/2022]
Abstract
Supplemental Digital Content is available in the text. Background— The Drosophila heart is an important model for studying the genetics underpinning mammalian cardiac function. The system comprises contractile cardiomyocytes, adjacent to which are pairs of highly endocytic pericardial nephrocytes that modulate cardiac function by uncharacterized mechanisms. Identifying these mechanisms and the molecules involved is important because they may be relevant to human cardiac physiology. Methods and Results— This work aimed to identify circulating cardiomodulatory factors of potential relevance to humans using the Drosophila nephrocyte–cardiomyocyte system. A Kruppel-like factor 15 (dKlf15) loss-of-function strategy was used to ablate nephrocytes and then heart function and the hemolymph proteome were analyzed. Ablation of nephrocytes led to a severe cardiomyopathy characterized by a lengthening of diastolic interval. Rendering adult nephrocytes dysfunctional by disrupting their endocytic function or temporally conditional knockdown of dKlf15 led to a similar cardiomyopathy. Proteomics revealed that nephrocytes regulate the circulating levels of many secreted proteins, the most notable of which was the evolutionarily conserved matricellular protein Secreted Protein Acidic and Rich in Cysteine (SPARC), a protein involved in mammalian cardiac function. Finally, reducing SPARC gene dosage ameliorated the cardiomyopathy that developed in the absence of nephrocytes. Conclusions— The data implicate SPARC in the noncell autonomous control of cardiac function in Drosophila and suggest that modulation of SPARC gene expression may ameliorate cardiac dysfunction in humans.
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Affiliation(s)
- Paul S Hartley
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA.
| | - Khatereh Motamedchaboki
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Rolf Bodmer
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Karen Ocorr
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA.
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30
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Ivy JR, Drechsler M, Catterson JH, Bodmer R, Ocorr K, Paululat A, Hartley PS. Klf15 Is Critical for the Development and Differentiation of Drosophila Nephrocytes. PLoS One 2015; 10:e0134620. [PMID: 26301956 PMCID: PMC4547745 DOI: 10.1371/journal.pone.0134620] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 07/11/2015] [Indexed: 12/20/2022] Open
Abstract
Insect nephrocytes are highly endocytic scavenger cells that represent the only invertebrate model for the study of human kidney podocytes. Despite their importance, nephrocyte development is largely uncharacterised. This work tested whether the insect ortholog of mammalian Kidney Krüppel-Like Factor (Klf15), a transcription factor required for mammalian podocyte differentiation, was required for insect nephrocyte development. It was found that expression of Drosophila Klf15 (dKlf15, previously known as Bteb2) was restricted to the only two nephrocyte populations in Drosophila, the garland cells and pericardial nephrocytes. Loss of dKlf15 function led to attrition of both nephrocyte populations and sensitised larvae to the xenotoxin silver nitrate. Although pericardial nephrocytes in dKlf15 loss of function mutants were specified during embryogenesis, they failed to express the slit diaphragm gene sticks and stones and did not form slit diaphragms. Conditional silencing of dKlf15 in adults led to reduced surface expression of the endocytic receptor Amnionless and loss of in vivo scavenger function. Over-expression of dKlf15 increased nephrocyte numbers and rescued age-dependent decline in nephrocyte function. The data place dKlf15 upstream of sns and Amnionless in a nephrocyte-restricted differentiation pathway and suggest dKlf15 expression is both necessary and sufficient to sustain nephrocyte differentiation. These findings explain the physiological relevance of dKlf15 in Drosophila and imply that the role of KLF15 in human podocytes is evolutionarily conserved.
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Affiliation(s)
- Jessica R. Ivy
- University of Edinburgh / British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Maik Drechsler
- Department of Zoology & Developmental Biology, University of Osnabrück, Barbarastr. 11, D-49069 Osnabrück, Germany
| | - James H. Catterson
- University of Edinburgh / British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Rolf Bodmer
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Karen Ocorr
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Achim Paululat
- Department of Zoology & Developmental Biology, University of Osnabrück, Barbarastr. 11, D-49069 Osnabrück, Germany
| | - Paul S. Hartley
- Department of Life and Environmental Science, University of Bournemouth, Talbot Campus, Poole, Dorset BH12 5BB, United Kingdom
- * E-mail:
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31
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Evans CJ, Liu T, Banerjee U. Drosophila hematopoiesis: Markers and methods for molecular genetic analysis. Methods 2014; 68:242-51. [PMID: 24613936 PMCID: PMC4051208 DOI: 10.1016/j.ymeth.2014.02.038] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 02/26/2014] [Accepted: 02/28/2014] [Indexed: 01/09/2023] Open
Abstract
Analyses of the Drosophila hematopoietic system are becoming more and more prevalent as developmental and functional parallels with vertebrate blood cells become more evident. Investigative work on the fly blood system has, out of necessity, led to the identification of new molecular markers for blood cell types and lineages and to the refinement of useful molecular genetic tools and analytical methods. This review briefly describes the Drosophila hematopoietic system at different developmental stages, summarizes the major useful cell markers and tools for each stage, and provides basic protocols for practical analysis of circulating blood cells and of the lymph gland, the larval hematopoietic organ.
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Affiliation(s)
- Cory J Evans
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ting Liu
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Utpal Banerjee
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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32
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ROS regulate cardiac function via a distinct paracrine mechanism. Cell Rep 2014; 7:35-44. [PMID: 24656823 PMCID: PMC4164050 DOI: 10.1016/j.celrep.2014.02.029] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/10/2014] [Accepted: 02/20/2014] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) can act cell autonomously and in a paracrine manner by diffusing into nearby cells. Here, we reveal a ROS-mediated paracrine signaling mechanism that does not require entry of ROS into target cells. We found that under physiological conditions, nonmyocytic pericardial cells (PCs) of the Drosophila heart contain elevated levels of ROS compared to the neighboring cardiomyocytes (CMs). We show that ROS in PCs act in a paracrine manner to regulate normal cardiac function, not by diffusing into the CMs to exert their function, but by eliciting a downstream D-MKK3-D-p38 MAPK signaling cascade in PCs that acts on the CMs to regulate their function. We find that ROS-D-p38 signaling in PCs during development is also important for establishing normal adult cardiac function. Our results provide evidence for a previously unrecognized role of ROS in mediating PC/CM interactions that significantly modulates heart function.
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Honti V, Csordás G, Kurucz É, Márkus R, Andó I. The cell-mediated immunity of Drosophila melanogaster: hemocyte lineages, immune compartments, microanatomy and regulation. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 42:47-56. [PMID: 23800719 DOI: 10.1016/j.dci.2013.06.005] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 06/02/2023]
Abstract
In the animal kingdom, innate immunity is the first line of defense against invading pathogens. The dangers of microbial and parasitic attacks are countered by similar mechanisms, involving the prototypes of the cell-mediated immune responses, the phagocytosis and encapsulation. Work on Drosophila has played an important role in promoting an understanding of the basic mechanisms of phylogenetically conserved modules of innate immunity. The aim of this review is to survey the developments in the identification and functional definition of immune cell types and the immunological compartments of Drosophila melanogaster. We focus on the molecular and developmental aspects of the blood cell types and compartments, as well as the dynamics of blood cell development and the immune response. Further advances in the characterization of the innate immune mechanisms in Drosophila will provide basic clues to the understanding of the importance of the evolutionary conserved mechanisms of innate immune defenses in the animal kingdom.
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Affiliation(s)
- Viktor Honti
- Institute of Genetics Biological Research Centre of the Hungarian Academy of Sciences, P.O. Box 521, Szeged H-6701, Hungary
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34
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Rahman MM, Sykiotis GP, Nishimura M, Bodmer R, Bohmann D. Declining signal dependence of Nrf2-MafS-regulated gene expression correlates with aging phenotypes. Aging Cell 2013; 12:554-62. [PMID: 23521918 PMCID: PMC3714369 DOI: 10.1111/acel.12078] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2013] [Indexed: 11/26/2022] Open
Abstract
Aging is a degenerative process characterized by declining molecular, cell and organ functions, and accompanied by the progressive accumulation of oxidatively damaged macromolecules. This increased oxidative damage may be causally related to an age-associated dysfunction of defense mechanisms, which effectively protect young individuals from oxidative insults. Consistently, older organisms are more sensitive to acute oxidative stress exposures than young ones. In studies on the Drosophila Nrf2 transcription factor CncC, we have investigated possible causes for this loss of stress resistance and its connection to the aging process. Nrf2 is a master regulator of antioxidant and stress defense gene expression with established functions in the control of longevity. Here, we show that the expression of protective Nrf2/CncC target genes in unstressed conditions does not generally decrease in older flies. However, aging flies progressively lose the ability to activate Nrf2 targets in response to acute stress exposure. We propose that the resulting inability to dynamically adjust the expression of Nrf2 target genes to the organism's internal and external conditions contributes to age-related loss of homeostasis and fitness. In support of this hypothesis, we find the Drosophila small Maf protein, MafS, an Nrf2 dimerization partner, to be critical to maintain responsiveness of the Nrf2 system: overexpression of MafS in older flies preserves Nrf2/CncC signaling competence and antagonizes age-associated functional decline. The maintenance of acute stress resistance, motor function, and heart performance in aging flies overexpressing MafS supports a critical role for signal responsiveness of Nrf2 function in promoting youthful phenotypes.
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Affiliation(s)
- M. Mahidur Rahman
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Gerasimos P. Sykiotis
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Mayuko Nishimura
- Development and Aging Program, Sanford/Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Rolf Bodmer
- Development and Aging Program, Sanford/Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Dirk Bohmann
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
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35
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Pendse J, Ramachandran PV, Na J, Narisu N, Fink JL, Cagan RL, Collins FS, Baranski TJ. A Drosophila functional evaluation of candidates from human genome-wide association studies of type 2 diabetes and related metabolic traits identifies tissue-specific roles for dHHEX. BMC Genomics 2013; 14:136. [PMID: 23445342 PMCID: PMC3608171 DOI: 10.1186/1471-2164-14-136] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 02/14/2013] [Indexed: 12/30/2022] Open
Abstract
Background Genome-wide association studies (GWAS) identify regions of the genome that are associated with particular traits, but do not typically identify specific causative genetic elements. For example, while a large number of single nucleotide polymorphisms associated with type 2 diabetes (T2D) and related traits have been identified by human GWAS, only a few genes have functional evidence to support or to rule out a role in cellular metabolism or dietary interactions. Here, we use a recently developed Drosophila model in which high-sucrose feeding induces phenotypes similar to T2D to assess orthologs of human GWAS-identified candidate genes for risk of T2D and related traits. Results Disrupting orthologs of certain T2D candidate genes (HHEX, THADA, PPARG, KCNJ11) led to sucrose-dependent toxicity. Tissue-specific knockdown of the HHEX ortholog dHHEX (CG7056) directed metabolic defects and enhanced lethality; for example, fat-body-specific loss of dHHEX led to increased hemolymph glucose and reduced insulin sensitivity. Conclusion Candidate genes identified in human genetic studies of metabolic traits can be prioritized and functionally characterized using a simple Drosophila approach. To our knowledge, this is the first large-scale effort to study the functional interaction between GWAS-identified candidate genes and an environmental risk factor such as diet in a model organism system.
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Affiliation(s)
- Jay Pendse
- Department of Developmental and Regenerative Biology, Mount SinaiSchool of Medicine, New York, NY, USA
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Na J, Musselman LP, Pendse J, Baranski TJ, Bodmer R, Ocorr K, Cagan R. A Drosophila model of high sugar diet-induced cardiomyopathy. PLoS Genet 2013; 9:e1003175. [PMID: 23326243 PMCID: PMC3542070 DOI: 10.1371/journal.pgen.1003175] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 10/22/2012] [Indexed: 12/16/2022] Open
Abstract
Diets high in carbohydrates have long been linked to progressive heart dysfunction, yet the mechanisms by which chronic high sugar leads to heart failure remain poorly understood. Here we combine diet, genetics, and physiology to establish an adult Drosophila melanogaster model of chronic high sugar-induced heart disease. We demonstrate deterioration of heart function accompanied by fibrosis-like collagen accumulation, insulin signaling defects, and fat accumulation. The result was a shorter life span that was more severe in the presence of reduced insulin and P38 signaling. We provide evidence of a role for hexosamine flux, a metabolic pathway accessed by glucose. Increased hexosamine flux led to heart function defects and structural damage; conversely, cardiac-specific reduction of pathway activity prevented sugar-induced heart dysfunction. Our data establish Drosophila as a useful system for exploring specific aspects of diet-induced heart dysfunction and emphasize enzymes within the hexosamine biosynthetic pathway as candidate therapeutic targets.
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Affiliation(s)
- Jianbo Na
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Laura Palanker Musselman
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jay Pendse
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Thomas J. Baranski
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Rolf Bodmer
- Development and Aging Program, NASCR Center, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Karen Ocorr
- Development and Aging Program, NASCR Center, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail:
| | - Ross Cagan
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, United States of America
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Zhang F, Zhao Y, Han Z. An in vivo functional analysis system for renal gene discovery in Drosophila pericardial nephrocytes. J Am Soc Nephrol 2013; 24:191-7. [PMID: 23291470 DOI: 10.1681/asn.2012080769] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The difficulty in accessing mammalian nephrons in vivo hinders the study of podocyte biology. The Drosophila nephrocyte shares remarkable similarities to the glomerular podocyte, but the lack of a functional readout for nephrocytes makes it challenging to study this model of the podocyte, which could potentially harness the power of Drosophila genetics. Here, we present a functional analysis of nephrocytes and establish an in vivo system to screen for renal genes. We found that nephrocytes efficiently take up secreted fluorescent protein, and therefore, we generated a transgenic line carrying secreted fluorescent protein and combined it with a nephrocyte-specific driver for targeted gene knockdown, allowing the identification of genes required for nephrocyte function. To validate this system, we examined the effects of knocking down sns and duf, the Drosophila homologs of nephrin and Neph1, respectively, in pericardial nephrocytes. Knockdown of sns or duf completely abolished the accumulation of the fluorescent protein in pericardial nephrocytes. Examining the ultrastructure revealed that the formation of the nephrocyte diaphragm and lacunar structure, which is essential for protein uptake, requires sns. Our preliminary genetic screen also identified Mec2, which encodes the homolog of mammalian Podocin. Taken together, these data suggest that the Drosophila pericardial nephrocyte is a useful in vivo model to help identify genes involved in podocyte biology and facilitate the discovery of renal disease genes.
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Affiliation(s)
- Fujian Zhang
- Department of Internal Medicine, Division of Molecular Medicine and Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Regulation of hemocytes in Drosophila requires dappled cytochrome b5. Biochem Genet 2011; 49:329-51. [PMID: 21279680 PMCID: PMC3092937 DOI: 10.1007/s10528-010-9411-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 12/20/2010] [Indexed: 12/12/2022]
Abstract
A major category of mutant hematopoietic phenotypes in Drosophila is melanotic tumors or nodules, which consist of abnormal and overproliferated blood cells, similar to granulomas. Our analyses of the melanotic mutant dappled have revealed a novel type of gene involved in blood cell regulation. The dappled gene is an essential gene that encodes cytochrome b5, a conserved hemoprotein that participates in electron transfer in multiple biochemical reactions and pathways. Viable mutations of dappled cause melanotic nodules and hemocyte misregulation during both hematopoietic waves of development. The sexes are similarly affected, but hemocyte number is different in females and males of both mutants and wild type. Additionally, initial tests show that curcumin enhances the dappled melanotic phenotype and establish screening of endogenous and xenobiotic compounds as a route for analysis of cytochrome b5 function. Overall, dappled provides a tractable genetic model for cytochrome b5, which has been difficult to study in higher organisms.
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Honti V, Csordás G, Márkus R, Kurucz E, Jankovics F, Andó I. Cell lineage tracing reveals the plasticity of the hemocyte lineages and of the hematopoietic compartments in Drosophila melanogaster. Mol Immunol 2010; 47:1997-2004. [PMID: 20483458 DOI: 10.1016/j.molimm.2010.04.017] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 04/22/2010] [Indexed: 10/19/2022]
Abstract
Much of our knowledge on hematopoiesis, hematopoietic compartments, hematopoietic cell lineages and immunity has been derived from studies on the vertebrate immune system. The sophisticated innate immunity of insects, the phylogenetic conservation and the power of Drosophila genetics allowed the investigation of immune cell (hemocyte) lineage relationships in Drosophila melanogaster. The development of the hemocyte lineages in Drosophila is a result of a precisely regulated succession of intracellular and intercellular events, though the nature and extent of these interactions are not known. We describe here a cell lineage tracing system set up to analyze the development of hemocyte lineages and functionally distinct hemocyte subsets. This system allowed us to distinguish two major embryonic hemocyte lineages, the crq and Dot lineages, in two, physically separated compartments, the embryonic macrophages and the embryonic lymph gland. We followed the fate and development of these lineages in the construction of the larval hematopoietic compartments and during the cell-mediated immune response, the encapsulation reaction. Our results revealed the considerable plasticity and concerted action of the hematopoietic compartments and the hemocyte lineages in the development of the innate immune system and in the course of the cell-mediated immune response in Drosophila.
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Affiliation(s)
- Viktor Honti
- Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Temesvári krt. 62, 6726 Szeged, Csongrád, Hungary
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Shafer OT, Taghert PH. RNA-interference knockdown of Drosophila pigment dispersing factor in neuronal subsets: the anatomical basis of a neuropeptide's circadian functions. PLoS One 2009; 4:e8298. [PMID: 20011537 PMCID: PMC2788783 DOI: 10.1371/journal.pone.0008298] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Accepted: 11/17/2009] [Indexed: 01/18/2023] Open
Abstract
Background In animals, neuropeptide signaling is an important component of circadian timekeeping. The neuropeptide pigment dispersing factor (PDF) is required for several aspects of circadian activity rhythms in Drosophila. Methodology/Principal Findings Here we investigate the anatomical basis for PDF's various circadian functions by targeted PDF RNA-interference in specific classes of Drosophila neuron. We demonstrate that PDF is required in the ventro-lateral neurons (vLNs) of the central brain and not in the abdominal ganglion for normal activity rhythms. Differential knockdown of PDF in the large or small vLNs indicates that PDF from the small vLNs is likely responsible for the maintenance of free-running activity rhythms and that PDF is not required in the large vLNs for normal behavior. PDF's role in setting the period of free-running activity rhythms and the proper timing of evening activity under light:dark cycles emanates from both subtypes of vLN, since PDF in either class of vLN was sufficient for these aspects of behavior. Conclusions/Significance These results reveal the neuroanatomical basis PDF's various circadian functions and refine our understanding of the clock neuron circuitry of Drosophila.
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Affiliation(s)
- Orie T Shafer
- Department of Anatomy and Neurobiology, Washington University Medical School, St. Louis, Missouri, United States of America.
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Soukup SF, Culi J, Gubb D. Uptake of the necrotic serpin in Drosophila melanogaster via the lipophorin receptor-1. PLoS Genet 2009; 5:e1000532. [PMID: 19557185 PMCID: PMC2694266 DOI: 10.1371/journal.pgen.1000532] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Accepted: 05/22/2009] [Indexed: 11/18/2022] Open
Abstract
The humoral response to fungal and Gram-positive infections is regulated by the serpin-family inhibitor, Necrotic. Following immune-challenge, a proteolytic cascade is activated which signals through the Toll receptor. Toll activation results in a range of antibiotic peptides being synthesised in the fat-body and exported to the haemolymph. As with mammalian serpins, Necrotic turnover in Drosophila is rapid. This serpin is synthesised in the fat-body, but its site of degradation has been unclear. By “freezing” endocytosis with a temperature sensitive Dynamin mutation, we demonstrate that Necrotic is removed from the haemolymph in two groups of giant cells: the garland and pericardial athrocytes. Necrotic uptake responds rapidly to infection, being visibly increased after 30 mins and peaking at 6–8 hours. Co-localisation of anti-Nec with anti-AP50, Rab5, and Rab7 antibodies establishes that the serpin is processed through multi-vesicular bodies and delivered to the lysosome, where it co-localises with the ubiquitin-binding protein, HRS. Nec does not co-localise with Rab11, indicating that the serpin is not re-exported from athrocytes. Instead, mutations which block late endosome/lysosome fusion (dor, hk, and car) cause accumulation of Necrotic-positive endosomes, even in the absence of infection. Knockdown of the 6 Drosophila orthologues of the mammalian LDL receptor family with dsRNA identifies LpR1 as an enhancer of the immune response. Uptake of Necrotic from the haemolymph is blocked by a chromosomal deletion of LpR1. In conclusion, we identify the cells and the receptor molecule responsible for the uptake and degradation of the Necrotic serpin in Drosophila melanogaster. The scavenging of serpin/proteinase complexes may be a critical step in the regulation of proteolytic cascades. Serpin inhibitors control a wide range of rapid physiological responses that are activated by proteolytic cascades, such as blood coagulation, inflammation, the complement pathway, and angiogenesis. They interact with their target proteinases by a “suicide inhibition” mechanism, which generates an inert, denatured, serpin/proteinase complex. In mammals, humoral serpins are secreted from the liver into the blood plasma. The denatured complex is later endocytosed back into the liver and degraded. In Drosophila, the Necrotic serpin is secreted from the fat-body into the haemolymph, where it controls the humoral immune response. We show here, however, that Necrotic is not endocytosed in the fat-body, but in the garland and pericardial athrocytes. These cells clear serpins from the haemolymph extremely rapidly. The Necrotic-binding receptor for this process is LpR1, a member of the LDLR family. The endocytosed serpin is targeted for lysosomal degradation, with none being recycled to the haemolymph. More importantly, we show that mutations in LpR1 cause a profound effect on the immune response. Thus, our results indicate that the scavenging of serpin/proteinase complexes might be a critical step in the regulation of proteolytic cascades.
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Affiliation(s)
| | - Joaquim Culi
- Centro Andaluz de Biología del Desarrollo (CSIC-UPO), Universidad Pablo de Olavide, Sevilla, Spain
| | - David Gubb
- Functional Genomics Unit, CIC bioGUNE, Derio, Spain
- * E-mail:
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Control of metabolic homeostasis by stress signaling is mediated by the lipocalin NLaz. PLoS Genet 2009; 5:e1000460. [PMID: 19390610 PMCID: PMC2667264 DOI: 10.1371/journal.pgen.1000460] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Accepted: 03/25/2009] [Indexed: 11/19/2022] Open
Abstract
Metabolic homeostasis in metazoans is regulated by endocrine control of insulin/IGF signaling (IIS) activity. Stress and inflammatory signaling pathways--such as Jun-N-terminal Kinase (JNK) signaling--repress IIS, curtailing anabolic processes to promote stress tolerance and extend lifespan. While this interaction constitutes an adaptive response that allows managing energy resources under stress conditions, excessive JNK activity in adipose tissue of vertebrates has been found to cause insulin resistance, promoting type II diabetes. Thus, the interaction between JNK and IIS has to be tightly regulated to ensure proper metabolic adaptation to environmental challenges. Here, we identify a new regulatory mechanism by which JNK influences metabolism systemically. We show that JNK signaling is required for metabolic homeostasis in flies and that this function is mediated by the Drosophila Lipocalin family member Neural Lazarillo (NLaz), a homologue of vertebrate Apolipoprotein D (ApoD) and Retinol Binding Protein 4 (RBP4). Lipocalins are emerging as central regulators of peripheral insulin sensitivity and have been implicated in metabolic diseases. NLaz is transcriptionally regulated by JNK signaling and is required for JNK-mediated stress and starvation tolerance. Loss of NLaz function reduces stress resistance and lifespan, while its over-expression represses growth, promotes stress tolerance and extends lifespan--phenotypes that are consistent with reduced IIS activity. Accordingly, we find that NLaz represses IIS activity in larvae and adult flies. Our results show that JNK-NLaz signaling antagonizes IIS and is critical for metabolic adaptation of the organism to environmental challenges. The JNK pathway and Lipocalins are structurally and functionally conserved, suggesting that similar interactions represent an evolutionarily conserved system for the control of metabolic homeostasis.
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Mann T, Bodmer R, Pandur P. The Drosophila homolog of vertebrate Islet1 is a key component in early cardiogenesis. Development 2008; 136:317-26. [PMID: 19088091 DOI: 10.1242/dev.022533] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In mouse, the LIM-homeodomain transcription factor Islet1 (Isl1) has been shown to demarcate a separate cardiac cell population that is essential for the formation of the right ventricle and the outflow tract of the heart. Whether Isl1 plays a crucial role in the early regulatory network of transcription factors that establishes a cardiac fate in mesodermal cells has not been fully resolved. We have analyzed the role of the Drosophila homolog of Isl1, tailup (tup), in cardiac specification and formation of the dorsal vessel. The early expression of Tup in the cardiac mesoderm suggests that Tup functions in cardiac specification. Indeed, tup mutants are characterized by a reduction of the essential early cardiac transcription factors Tin, Pnr and Dorsocross1-3 (Doc). Conversely, Tup expression depends on each of these cardiac factors, as well as on the early inductive signals Dpp and Wg. Genetic interactions show that tup cooperates with tin, pnr and Doc in heart cell specification. Germ layer-specific loss-of-function and rescue experiments reveal that Tup also functions in the ectoderm to regulate cardiogenesis and implicate the involvement of different LIM-domain-interacting proteins in the mesoderm and ectoderm. Gain-of-function analyses for tup and pnr suggest that a proper balance of these factors is also required for the specification of Eve-expressing pericardial cells. Since tup is required for proper cardiogenesis in an invertebrate organism, we believe it is appropriate to include tup/Isl1 in the core set of ancestral cardiac transcription factors that govern a cardiac fate.
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Affiliation(s)
- Tabea Mann
- Institute for Biochemistry and Molecular Biology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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Das D, Aradhya R, Ashoka D, Inamdar M. Macromolecular uptake in Drosophila pericardial cells requires rudhira function. Exp Cell Res 2008; 314:1804-10. [PMID: 18355807 DOI: 10.1016/j.yexcr.2008.02.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 02/13/2008] [Accepted: 02/19/2008] [Indexed: 01/10/2023]
Abstract
The vertebrate reticuloendothelial system (RES) functions to remove potentially damaging macromolecules, such as excess hormones, immune-peptides and -complexes, bacterial-endotoxins, microorganisms and tumor cells. Insect hemocytes and nephrocytes - which include pericardial cells (PCs) and garland cells - are thought to be functionally equivalent to the RES. Although the ability of both vertebrate scavenger endothelial cells (SECs) and PCs to sequester colloidal and soluble macromolecules has been demonstrated the molecular mechanism of this function remains to be investigated. We report here the functional characterization of Drosophila larval PCs with important insights into their cellular uptake pathways. We demonstrate the nephrocyte function of PCs in live animals. We also develop and use live-cell assays to show that PCs take up soluble macromolecules in a Dynamin-dependent manner and colloids by a Dynamin-independent pathway. We had earlier identified Drosophila rudhira (Drudh) as a specific marker for PCs. Using RNAi mediated knock-down we show that Drudh regulates macropinocytic uptake in PCs. Our study establishes important functions for Drosophila PCs, describes methods to identify and study them, provides a genetic handle for further investigation of their role in maintaining homeostasis and demonstrates that they perform key subsets of the roles played by the vertebrate RES.
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Affiliation(s)
- Debjani Das
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560064, India
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Leeuw TK, Reith RM, Simonette RA, Harden ME, Cherukuri P, Tsyboulski DA, Beckingham KM, Weisman RB. Single-walled carbon nanotubes in the intact organism: near-IR imaging and biocompatibility studies in Drosophila. NANO LETTERS 2007; 7:2650-4. [PMID: 17696559 DOI: 10.1021/nl0710452] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The ability of near-infrared fluorescence imaging to detect single-walled carbon nanotubes (SWNTs) in organisms and biological tissues has been explored using Drosophila melanogaster (fruit flies). Drosophila larvae were raised on food containing approximately 10 ppm of disaggregated SWNTs. Their viability and growth were not reduced by nanotube ingestion. Near-IR nanotube fluorescence was imaged from intact living larvae, and individual nanotubes in dissected tissue specimens were imaged, structurally identified, and counted to estimate a biodistribution.
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Affiliation(s)
- Tonya K Leeuw
- Department of Chemistry, Center for Biological and Environmental Nanotechnology, R. E. Smalley Institute for Nanoscale Science and Technology, and Institute for Biosciences and Bioengineering, Rice University, 6100 Main Street, Houston, Texas 77005, USA
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46
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Llorens JV, Navarro JA, Martínez-Sebastián MJ, Baylies MK, Schneuwly S, Botella JA, Moltó MD. Causative role of oxidative stress in a Drosophila model of Friedreich ataxia. FASEB J 2007; 21:333-44. [PMID: 17167074 DOI: 10.1096/fj.05-5709com] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Friedreich ataxia (FA), the most common form of hereditary ataxia, is caused by a deficit in the mitochondrial protein frataxin. While several hypotheses have been suggested, frataxin function is not well understood. Oxidative stress has been suggested to play a role in the pathophysiology of FA, but this view has been recently questioned, and its link to frataxin is unclear. Here, we report the use of RNA interference (RNAi) to suppress the Drosophila frataxin gene (fh) expression. This model system parallels the situation in FA patients, namely a moderate systemic reduction of frataxin levels compatible with normal embryonic development. Under these conditions, fh-RNAi flies showed a shortened life span, reduced climbing abilities, and enhanced sensitivity to oxidative stress. Under hyperoxia, fh-RNAi flies also showed a dramatic reduction of aconitase activity that seriously impairs the mitochondrial respiration while the activities of succinate dehydrogenase, respiratory complex I and II, and indirectly complex III and IV are normal. Remarkably, frataxin overexpression also induced the oxidative-mediated inactivation of mitochondrial aconitase. This work demonstrates, for the first time, the essential function of frataxin in protecting aconitase from oxidative stress-dependent inactivation in a multicellular organism. Moreover our data support an important role of oxidative stress in the progression of FA and suggest a tissue-dependent sensitivity to frataxin imbalance. We propose that in FA, the oxidative mediated inactivation of aconitase, which occurs normally during the aging process, is enhanced due to the lack of frataxin.
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Affiliation(s)
- José V Llorens
- Departament de Genètica, Universitat de València, Carrer Doctor Moliner 50, 46100-Burjassot, Valencia, Spain
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Dolezal T, Dolezelova E, Zurovec M, Bryant PJ. A role for adenosine deaminase in Drosophila larval development. PLoS Biol 2005; 3:e201. [PMID: 15907156 PMCID: PMC1135298 DOI: 10.1371/journal.pbio.0030201] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Accepted: 03/29/2005] [Indexed: 11/24/2022] Open
Abstract
Adenosine deaminase (ADA) is an enzyme present in all organisms that catalyzes the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine. Both adenosine and deoxyadenosine are biologically active purines that can have a deep impact on cellular physiology; notably, ADA deficiency in humans causes severe combined immunodeficiency. We have established a Drosophila model to study the effects of altered adenosine levels in vivo by genetic elimination of adenosine deaminase-related growth factor-A (ADGF-A), which has ADA activity and is expressed in the gut and hematopoietic organ. Here we show that the hemocytes (blood cells) are the main regulator of adenosine in the Drosophila larva, as was speculated previously for mammals. The elevated level of adenosine in the hemolymph due to lack of ADGF-A leads to apparently inconsistent phenotypic effects: precocious metamorphic changes including differentiation of macrophage-like cells and fat body disintegration on one hand, and delay of development with block of pupariation on the other. The block of pupariation appears to involve signaling through the adenosine receptor (AdoR), but fat body disintegration, which is promoted by action of the hemocytes, seems to be independent of the AdoR. The existence of such an independent mechanism has also been suggested in mammals. Adenosine deaminase is critically important to survival; congenital deficiency in humans leads to severe immunodeficiency. Here, the authors demonstrate that adenosine deaminase deficiency in flies results in severe developmental defects.
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Affiliation(s)
- Tomas Dolezal
- 1Developmental Biology Center, University of California, Irvine, California, United States of America
| | - Eva Dolezelova
- 2Institute of Entomology and University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Michal Zurovec
- 2Institute of Entomology and University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Peter J Bryant
- 1Developmental Biology Center, University of California, Irvine, California, United States of America
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Jung SH, Evans CJ, Uemura C, Banerjee U. The Drosophila lymph gland as a developmental model of hematopoiesis. Development 2005; 132:2521-33. [PMID: 15857916 DOI: 10.1242/dev.01837] [Citation(s) in RCA: 298] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Drosophila hematopoiesis occurs in a specialized organ called the lymph gland. In this systematic analysis of lymph gland structure and gene expression, we define the developmental steps in the maturation of blood cells (hemocytes) from their precursors. In particular, distinct zones of hemocyte maturation, signaling and proliferation in the lymph gland during hematopoietic progression are described. Different stages of hemocyte development have been classified according to marker expression and placed within developmental niches: a medullary zone for quiescent prohemocytes, a cortical zone for maturing hemocytes and a zone called the posterior signaling center for specialized signaling hemocytes. This establishes a framework for the identification of Drosophila blood cells, at various stages of maturation, and provides a genetic basis for spatial and temporal events that govern hemocyte development. The cellular events identified in this analysis further establish Drosophila as a model system for hematopoiesis.
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Affiliation(s)
- Seung-Hye Jung
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA 90095, USA
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49
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Muyrers-Chen I, Rozovskaia T, Lee N, Kersey JH, Nakamura T, Canaani E, Paro R. Expression of leukemic MLL fusion proteins in Drosophila affects cell cycle control and chromosome morphology. Oncogene 2004; 23:8639-48. [PMID: 15378024 DOI: 10.1038/sj.onc.1207904] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Mixed Lineage Leukemia (MLL) gene is involved in lymphoblastic and myeloid leukemia through chromosome translocations leading to fusion of MLL to partner genes, or through internal MLL rearrangements. MLL is the mammalian counterpart of the Drosophila trithorax (trx) gene, involved in maintaining active gene expression states. We have used transgenic Drosophila to assess the molecular targets and cellular processes affected by MLL and two of its leukemic fusion proteins. We find that whereas expression of normal human MLL in flies does not result in phenotypic alterations, overexpressing the human MLL-AF9 and MLL-AF4 proteins causes larval to pupal lethality, which interestingly resembles the phenotypes displayed by certain Drosophila trx mutant alleles. MLL-AF9 and MLL-AF4 transgenic flies exhibit antagonistic alterations in cell cycle progression. Additionally, flies expressing MLL-AF9 display impairment in higher order chromatin integrity, evidenced in decondensation of mitotic figures. The effects of MLL fusion proteins in Drosophila suggest that alteration of chromatin structure by MLL fusion proteins may contribute to the lethal phenotype. Our results indicate that the mode(s) of action of MLL-AF9 in Drosophila varies from that of MLL-AF4. Taken together, the expression of MLL fusion proteins in Drosophila provides a new and powerful system to reveal and characterize biological activities associated with MLL fusion proteins.
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