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Davis GH, Zaya A, Pearce MMP. Impairment of the Glial Phagolysosomal System Drives Prion-Like Propagation in a Drosophila Model of Huntington's Disease. J Neurosci 2024; 44:e1256232024. [PMID: 38589228 PMCID: PMC11097281 DOI: 10.1523/jneurosci.1256-23.2024] [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: 07/06/2023] [Revised: 01/31/2024] [Accepted: 02/26/2024] [Indexed: 04/10/2024] Open
Abstract
Protein misfolding, aggregation, and spread through the brain are primary drivers of neurodegenerative disease pathogenesis. Phagocytic glia are responsible for regulating the load of pathological proteins in the brain, but emerging evidence suggests that glia may also act as vectors for aggregate spread. Accumulation of protein aggregates could compromise the ability of glia to eliminate toxic materials from the brain by disrupting efficient degradation in the phagolysosomal system. A better understanding of phagocytic glial cell deficiencies in the disease state could help to identify novel therapeutic targets for multiple neurological disorders. Here, we report that mutant huntingtin (mHTT) aggregates impair glial responsiveness to injury and capacity to degrade neuronal debris in male and female adult Drosophila expressing the gene that causes Huntington's disease (HD). mHTT aggregate formation in neurons impairs engulfment and clearance of injured axons and causes accumulation of phagolysosomes in glia. Neuronal mHTT expression induces upregulation of key innate immunity and phagocytic genes, some of which were found to regulate mHTT aggregate burden in the brain. A forward genetic screen revealed Rab10 as a novel component of Draper-dependent phagocytosis that regulates mHTT aggregate transmission from neurons to glia. These data suggest that glial phagocytic defects enable engulfed mHTT aggregates to evade lysosomal degradation and acquire prion-like characteristics. Together, our findings uncover new mechanisms that enhance our understanding of the beneficial and harmful effects of phagocytic glia in HD and other neurodegenerative diseases.
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Affiliation(s)
- Graham H Davis
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, New Jersey 08028
- Department of Biology, Saint Joseph's University, Philadelphia, Pennsylvania 19131
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
| | - Aprem Zaya
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
| | - Margaret M Panning Pearce
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, New Jersey 08028
- Department of Biology, Saint Joseph's University, Philadelphia, Pennsylvania 19131
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
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2
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Perlmutter JI, Chapman JR, Wilkinson MC, Nevarez-Saenz I, Unckless RL. A single amino acid polymorphism in natural Metchnikowin alleles of Drosophila results in systemic immunity and life history tradeoffs. PLoS Genet 2024; 20:e1011155. [PMID: 38466751 PMCID: PMC10957085 DOI: 10.1371/journal.pgen.1011155] [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: 07/06/2023] [Revised: 03/21/2024] [Accepted: 01/26/2024] [Indexed: 03/13/2024] Open
Abstract
Antimicrobial peptides (AMPs) are at the interface of interactions between hosts and microbes and are therefore expected to be rapidly evolving in a coevolutionary arms race with pathogens. In contrast, previous work demonstrated that insect AMPs tend to evolve more slowly than the genome average. Metchikowin (Mtk) is a Drosophila AMP that has a single amino acid residue that segregates as either proline (P) or arginine (R) in populations of four different species, some of which diverged more than 10 million years ago. These results suggest that there is a distinct functional importance to each allele. The most likely hypotheses are driven by two main questions: does each allele have a different efficacy against different specific pathogens (specificity hypothesis)? Or, is one allele a more potent antimicrobial, but with a host fitness cost (autoimmune hypothesis)? To assess their functional differences, we created D. melanogaster lines with the P allele, R allele, or Mtk null mutation using CRISPR/Cas9 genome editing and performed a series of life history and infection assays to assess them. In males, testing of systemic immune responses to a repertoire of bacteria and fungi demonstrated that the R allele performs as well or better than the P and null alleles with most infections. Females show some results that contrast with males, with Mtk alleles either not contributing to survival or with the P allele outperforming the R allele. In addition, measurements of life history traits demonstrate that the R allele is more costly in the absence of infection for both sexes. These results are consistent with both the specificity hypothesis (either allele can perform better against certain pathogens depending on context), and the autoimmune hypothesis (the R allele is generally the more potent antimicrobial in males, and carries a fitness cost). These results provide strong in vivo evidence that differential fitness with or without infection and sex-based functional differences in alleles may be adaptive mechanisms of maintaining immune gene polymorphisms in contrast with expectations of rapid evolution. Therefore, a complex interplay of forces including pathogen species and host sex may lead to balancing selection for immune genotypes. Strikingly, this selection may act on even a single amino acid polymorphism in an AMP.
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Affiliation(s)
- Jessamyn I. Perlmutter
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Joanne R. Chapman
- Institute of Environmental and Scientific Research (ESR), Christchurch, New Zealand
| | - Mason C. Wilkinson
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Isaac Nevarez-Saenz
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Robert L. Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
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3
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Davis GH, Zaya A, Pearce MMP. Impairment of the glial phagolysosomal system drives prion-like propagation in a Drosophila model of Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.04.560952. [PMID: 38370619 PMCID: PMC10871239 DOI: 10.1101/2023.10.04.560952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Protein misfolding, aggregation, and spread through the brain are primary drivers of neurodegenerative diseases pathogenesis. Phagocytic glia are responsible for regulating the load of pathogenic protein aggregates in the brain, but emerging evidence suggests that glia may also act as vectors for aggregate spread. Accumulation of protein aggregates could compromise the ability of glia to eliminate toxic materials from the brain by disrupting efficient degradation in the phagolysosomal system. A better understanding of phagocytic glial cell deficiencies in the disease state could help to identify novel therapeutic targets for multiple neurological disorders. Here, we report that mutant huntingtin (mHTT) aggregates impair glial responsiveness to injury and capacity to degrade neuronal debris in male and female adult Drosophila expressing the gene that causes Huntington's disease (HD). mHTT aggregate formation in neurons impairs engulfment and clearance of injured axons and causes accumulation of phagolysosomes in glia. Neuronal mHTT expression induces upregulation of key innate immunity and phagocytic genes, some of which were found to regulate mHTT aggregate burden in the brain. Finally, a forward genetic screen revealed Rab10 as a novel component of Draper-dependent phagocytosis that regulates mHTT aggregate transmission from neurons to glia. These data suggest that glial phagocytic defects enable engulfed mHTT aggregates to evade lysosomal degradation and acquire prion-like characteristics. Together, our findings reveal new mechanisms that enhance our understanding of the beneficial and potentially harmful effects of phagocytic glia in HD and potentially other neurodegenerative diseases.
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Affiliation(s)
- Graham H. Davis
- Rowan University, Department of Biological and Biomedical Sciences, Glassboro, NJ 08028
- Saint Joseph’s University, Department of Biology, Philadelphia, PA 19131
- University of the Sciences, Department of Biological Sciences, Philadelphia, PA 19104
| | - Aprem Zaya
- University of the Sciences, Department of Biological Sciences, Philadelphia, PA 19104
| | - Margaret M. Panning Pearce
- Rowan University, Department of Biological and Biomedical Sciences, Glassboro, NJ 08028
- Saint Joseph’s University, Department of Biology, Philadelphia, PA 19131
- University of the Sciences, Department of Biological Sciences, Philadelphia, PA 19104
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4
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Singh K, Gupta JK, Kumar S, Soni U. A Review of the Common Neurodegenerative Disorders: Current Therapeutic Approaches and the Potential Role of Bioactive Peptides. Curr Protein Pept Sci 2024; 25:507-526. [PMID: 38561605 DOI: 10.2174/0113892037275221240327042353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
Neurodegenerative disorders, which include Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS), represent a significant and growing global health challenge. Current therapies predominantly focus on symptom management rather than altering disease progression. In this review, we discuss the major therapeutic strategies in practice for these disorders, highlighting their limitations. For AD, the mainstay treatments are cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists. For PD, dopamine replacement therapies, including levodopa, are commonly used. HD is managed primarily with symptomatic treatments, and reusable extends survival in ALS. However, none of these therapies halts or substantially slows the neurodegenerative process. In contrast, this review highlights emerging research into bioactive peptides as potential therapeutic agents. These naturally occurring or synthetically designed molecules can interact with specific cellular targets, potentially modulating disease processes. Preclinical studies suggest that bioactive peptides may mitigate oxidative stress, inflammation, and protein misfolding, which are common pathological features in neurodegenerative diseases. Clinical trials using bioactive peptides for neurodegeneration are limited but show promising initial results. For instance, hemiacetal, a γ-secretase inhibitor peptide, has shown potential in AD by reducing amyloid-beta production, though its development was discontinued due to side effects. Despite these advancements, many challenges remain, including identifying optimal peptides, confirming their mechanisms of action, and overcoming obstacles related to their delivery to the brain. Future research should prioritize the discovery and development of novel bioactive peptides and improve our understanding of their pharmacokinetics and pharmacodynamics. Ultimately, this approach may lead to more effective therapies for neurodegenerative disorders, moving beyond symptom management to potentially modify the course of these devastating diseases.
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Affiliation(s)
- Kuldeep Singh
- Department of Pharmacology, Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
| | - Jeetendra Kumar Gupta
- Department of Pharmacology, Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
| | - Shivendra Kumar
- Department of Pharmacology, Rajiv Academy for Pharmacy, Mathura, Uttar Pradesh, India
| | - Urvashi Soni
- Department of Pharmacology, School of Health Sciences and Technology, Dr. Vishwanath Karad MIT World Peace University, Kothrud, Pune, Maharashtra, India
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5
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Vincow ES, Thomas RE, Milstein G, Pareek G, Bammler T, MacDonald J, Pallanck L. Glucocerebrosidase deficiency leads to neuropathology via cellular immune activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.13.571406. [PMID: 38168223 PMCID: PMC10760128 DOI: 10.1101/2023.12.13.571406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Mutations in GBA (glucosylceramidase beta), which encodes the lysosomal enzyme glucocerebrosidase (GCase), are the strongest genetic risk factor for the neurodegenerative disorders Parkinson's disease (PD) and Lewy body dementia. Recent work has suggested that neuroinflammation may be an important factor in the risk conferred by GBA mutations. We therefore systematically tested the contributions of immune-related genes to neuropathology in a Drosophila model of GCase deficiency. We identified target immune factors via RNA-Seq and proteomics on heads from GCase-deficient flies, which revealed both increased abundance of humoral factors and increased macrophage activation. We then manipulated the identified immune factors and measured their effect on head protein aggregates, a hallmark of neurodegenerative disease. Genetic ablation of humoral (secreted) immune factors did not suppress the development of protein aggregation. By contrast, re-expressing Gba1b in activated macrophages suppressed head protein aggregation in Gba1b mutants and rescued their lifespan and behavioral deficits. Moreover, reducing the GCase substrate glucosylceramide in activated macrophages also ameliorated Gba1b mutant phenotypes. Taken together, our findings show that glucosylceramide accumulation due to GCase deficiency leads to macrophage activation, which in turn promotes the development of neuropathology.
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Affiliation(s)
- Evelyn S. Vincow
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Ruth E. Thomas
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gillian Milstein
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gautam Pareek
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Theo Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - James MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Leo Pallanck
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
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6
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Tower J. Markers and mechanisms of death in Drosophila. FRONTIERS IN AGING 2023; 4:1292040. [PMID: 38149028 PMCID: PMC10749947 DOI: 10.3389/fragi.2023.1292040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/30/2023] [Indexed: 12/28/2023]
Abstract
Parameters correlated with age and mortality in Drosophila melanogaster include decreased negative geotaxis and centrophobism behaviors, decreased climbing and walking speed, and darkened pigments in oenocytes and eye. Cessation of egg laying predicts death within approximately 5 days. Endogenous green fluorescence in eye and body increases hours prior to death. Many flies exhibit erratic movement hours before death, often leading to falls. Loss of intestinal barrier integrity (IBI) is assayed by feeding blue dye ("Smurf" phenotype), and Smurf flies typically die within 0-48 h. Some studies report most flies exhibit Smurf, whereas multiple groups report most flies die without exhibiting Smurf. Transgenic reporters containing heat shock gene promoters and innate immune response gene promoters progressively increase expression with age, and partly predict remaining life span. Innate immune reporters increase with age in every fly, prior to any Smurf phenotype, in presence or absence of antibiotics. Many flies die on their side or supine (on their back) position. The data suggest three mechanisms for death of Drosophila. One is loss of IBI, as revealed by Smurf assay. The second is nervous system malfunction, leading to erratic behavior, locomotor malfunction, and falls. The aged fly is often unable to right itself after a fall to a side-ways or supine position, leading to inability to access the food and subsequent dehydration/starvation. Finally, some flies die upright without Smurf phenotype, suggesting a possible third mechanism. The frequency of these mechanisms varies between strains and culture conditions, which may affect efficacy of life span interventions.
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Affiliation(s)
- John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
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7
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Lee S, Jun YW, Linares GR, Butler B, Yuva-Adyemir Y, Moore J, Krishnan G, Ruiz-Juarez B, Santana M, Pons M, Silverman N, Weng Z, Ichida JK, Gao FB. Downregulation of Hsp90 and the antimicrobial peptide Mtk suppresses poly(GR)-induced neurotoxicity in C9ORF72-ALS/FTD. Neuron 2023; 111:1381-1390.e6. [PMID: 36931278 PMCID: PMC10264157 DOI: 10.1016/j.neuron.2023.02.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/22/2023] [Accepted: 02/16/2023] [Indexed: 03/18/2023]
Abstract
GGGGCC repeat expansion in the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Repeat RNAs can be translated into dipeptide repeat proteins, including poly(GR), whose mechanisms of action remain largely unknown. In an RNA-seq analysis of poly(GR) toxicity in Drosophila, we found that several antimicrobial peptide genes, such as metchnikowin (Mtk), and heat shock protein (Hsp) genes are activated. Mtk knockdown in the fly eye or in all neurons suppresses poly(GR) neurotoxicity. These findings suggest a cell-autonomous role of Mtk in neurodegeneration. Hsp90 knockdown partially rescues both poly(GR) toxicity in flies and neurodegeneration in C9ORF72 motor neurons derived from induced pluripotent stem cells (iPSCs). Topoisomerase II (TopoII) regulates poly(GR)-induced upregulation of Hsp90 and Mtk. TopoII knockdown also suppresses poly(GR) toxicity in Drosophila and improves survival of C9ORF72 iPSC-derived motor neurons. These results suggest potential novel therapeutic targets for C9ORF72-ALS/FTD.
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Affiliation(s)
- Soojin Lee
- Department of Neurology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Yong-Woo Jun
- Department of Neurology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Gabriel R Linares
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Brandon Butler
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Yeliz Yuva-Adyemir
- Department of Neurology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Jill Moore
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Gopinath Krishnan
- Department of Neurology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Bryan Ruiz-Juarez
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Manuel Santana
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Marine Pons
- Department of Neurology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Neal Silverman
- Division of Infectious Diseases and Immunology, Department of Medicine, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Justin K Ichida
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Fen-Biao Gao
- Department of Neurology, UMass Chan Medical School, Worcester, MA 01605, USA.
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8
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Katzenberger RJ, Ganetzky B, Wassarman DA. Lissencephaly-1 mutations enhance traumatic brain injury outcomes in Drosophila. Genetics 2023; 223:iyad008. [PMID: 36683334 PMCID: PMC9991514 DOI: 10.1093/genetics/iyad008] [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: 11/14/2022] [Revised: 11/14/2022] [Accepted: 01/16/2023] [Indexed: 01/24/2023] Open
Abstract
Traumatic brain injury (TBI) outcomes vary greatly among individuals, but most of the variation remains unexplained. Using a Drosophila melanogaster TBI model and 178 genetically diverse lines from the Drosophila Genetic Reference Panel (DGRP), we investigated the role that genetic variation plays in determining TBI outcomes. Following injury at 20-27 days old, DGRP lines varied considerably in mortality within 24 h ("early mortality"). Additionally, the disparity in early mortality resulting from injury at 20-27 vs 0-7 days old differed among DGRP lines. These data support a polygenic basis for differences in TBI outcomes, where some gene variants elicit their effects by acting on aging-related processes. Our genome-wide association study of DGRP lines identified associations between single nucleotide polymorphisms in Lissencephaly-1 (Lis-1) and Patronin and early mortality following injury at 20-27 days old. Lis-1 regulates dynein, a microtubule motor required for retrograde transport of many cargoes, and Patronin protects microtubule minus ends against depolymerization. While Patronin mutants did not affect early mortality, Lis-1 compound heterozygotes (Lis-1x/Lis-1y) had increased early mortality following injury at 20-27 or 0-7 days old compared with Lis-1 heterozygotes (Lis-1x/+), and flies that survived 24 h after injury had increased neurodegeneration but an unaltered lifespan, indicating that Lis-1 affects TBI outcomes independently of effects on aging. These data suggest that Lis-1 activity is required in the brain to ameliorate TBI outcomes through effects on axonal transport, microtubule stability, and other microtubule proteins, such as tau, implicated in chronic traumatic encephalopathy, a TBI-associated neurodegenerative disease in humans.
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Affiliation(s)
- Rebeccah J Katzenberger
- Department of Medical Genetics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Barry Ganetzky
- Department of Genetics, College of Agricultural and Life Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - David A Wassarman
- Department of Medical Genetics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
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Nukala KM, Lilienthal AJ, Lye SH, Bassuk AG, Chtarbanova S, Manak JR. Downregulation of oxidative stress-mediated glial innate immune response suppresses seizures in a fly epilepsy model. Cell Rep 2023; 42:112004. [PMID: 36641750 PMCID: PMC9942582 DOI: 10.1016/j.celrep.2023.112004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 11/30/2022] [Accepted: 01/03/2023] [Indexed: 01/15/2023] Open
Abstract
Previous work in our laboratory has shown that mutations in prickle (pk) cause myoclonic-like seizures and ataxia in Drosophila, similar to what is observed in humans carrying mutations in orthologous PRICKLE genes. Here, we show that pk mutant brains show elevated, sustained neuronal cell death that correlates with increasing seizure penetrance, as well as an upregulation of mitochondrial oxidative stress and innate immune response (IIR) genes. Moreover, flies exhibiting more robust seizures show increased levels of IIR-associated target gene expression suggesting they may be linked. Genetic knockdown in glia of either arm of the IIR (Immune Deficiency [Imd] or Toll) leads to a reduction in neuronal death, which in turn suppresses seizure activity, with oxidative stress acting upstream of IIR. These data provide direct genetic evidence that oxidative stress in combination with glial-mediated IIR leads to progression of an epilepsy disorder.
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Affiliation(s)
- Krishna M Nukala
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
| | | | - Shu Hui Lye
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Alexander G Bassuk
- Department of Pediatrics, University of Iowa and Carver College of Medicine, Iowa City, IA 52242, USA; Department of Neurology, University of Iowa and Carver College of Medicine, Iowa City, IA 52242, USA; The Iowa Neuroscience Institute, University of Iowa and Carver College of Medicine, Iowa City, IA 52242, USA
| | | | - J Robert Manak
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA; Department of Pediatrics, University of Iowa and Carver College of Medicine, Iowa City, IA 52242, USA.
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10
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Perlmutter JI, Chapman JR, Wilkinson MC, Nevarez-Saenz I, Unckless RL. A single amino acid polymorphism in natural Metchnikowin alleles of Drosophila results in systemic immunity and life history tradeoffs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.16.524277. [PMID: 36712113 PMCID: PMC9882182 DOI: 10.1101/2023.01.16.524277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Antimicrobial peptides (AMPs) are at the interface of interactions between hosts and microbes and are therefore expected to be fast evolving in a coevolutionary arms race with pathogens. In contrast, previous work demonstrated that one AMP, Metchikowin (Mtk), has a single residue that segregates as either proline (P) or arginine (R) in populations of four different Drosophila species, some of which diverged more than 10 million years ago. The recurrent finding of this polymorphism regardless of geography or host species, coupled with evidence of balancing selection in Drosophila AMPs, suggest there is a distinct functional importance to each allele. The most likely hypotheses involve alleles having specificity to different pathogens or the more potent allele conferring a cost on the host. To assess their functional differences, we created D. melanogaster lines with the P allele, R allele, or Mtk null mutation using CRISPR/Cas9 genome editing. Here, we report results from experiments assessing the two hypotheses using these lines. In males, testing of systemic immune responses to a repertoire of bacteria and fungi demonstrated that the R allele performs as well or better than the P and null alleles with most infections. With some pathogens, however, females show results in contrast with males where Mtk alleles either do not contribute to survival or where the P allele outperforms the R allele. In addition, measurements of life history traits demonstrate that the R allele is more costly in the absence of infection for both sexes. These results provide strong in vivo evidence that differential fitness with or without infection and sex-based functional differences in alleles may be adaptive mechanisms of maintaining immune gene polymorphisms in contrast with expectations of rapid evolution. Therefore, a complex interplay of forces including pathogen species and host sex may lead to balancing selection for immune genotypes. Strikingly, this selection may act on even a single amino acid polymorphism in an AMP.
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Affiliation(s)
| | - Joanne R. Chapman
- Institute of Environmental and Scientific Research (ESR), Christchurch, New Zealand
| | - Mason C. Wilkinson
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Isaac Nevarez-Saenz
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Robert L. Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
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11
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Hanson MA, Lemaitre B. Repeated truncation of a modular antimicrobial peptide gene for neural context. PLoS Genet 2022; 18:e1010259. [PMID: 35714143 PMCID: PMC9246212 DOI: 10.1371/journal.pgen.1010259] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/30/2022] [Accepted: 05/17/2022] [Indexed: 12/29/2022] Open
Abstract
Antimicrobial peptides (AMPs) are host-encoded antibiotics that combat invading pathogens. These genes commonly encode multiple products as post-translationally cleaved polypeptides. Recent studies have highlighted roles for AMPs in neurological contexts suggesting functions for these defence molecules beyond infection. During our immune study characterizing the antimicrobial peptide gene Baramicin, we recovered multiple Baramicin paralogs in Drosophila melanogaster and other species, united by their N-terminal IM24 domain. Not all paralogs were immune-induced. Here, through careful dissection of the Baramicin family's evolutionary history, we find that paralogs lacking immune induction result from repeated events of duplication and subsequent truncation of the coding sequence from an immune-inducible ancestor. These truncations leave only the IM24 domain as the prominent gene product. Surprisingly, using mutation and targeted gene silencing we demonstrate that two such genes are adapted for function in neural contexts in D. melanogaster. We also show enrichment in the head for independent Baramicin genes in other species. The Baramicin evolutionary history reveals that the IM24 Baramicin domain is not strictly useful in an immune context. We thus provide a case study for how an AMP-encoding gene might play dual roles in both immune and non-immune processes via its multiple peptide products. As many AMP genes encode polypeptides, a full understanding of how immune effectors interact with the nervous system will require consideration of all their peptide products.
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Affiliation(s)
- Mark A. Hanson
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- * E-mail:
| | - Bruno Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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12
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Delventhal R, Wooder ER, Basturk M, Sattar M, Lai J, Bolton D, Muthukumar G, Ulgherait M, Shirasu-Hiza MM. Dietary restriction ameliorates TBI-induced phenotypes in Drosophila melanogaster. Sci Rep 2022; 12:9523. [PMID: 35681073 PMCID: PMC9184478 DOI: 10.1038/s41598-022-13128-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/20/2022] [Indexed: 11/25/2022] Open
Abstract
Traumatic brain injury (TBI) affects millions annually and is associated with long-term health decline. TBI also shares molecular and cellular hallmarks with neurodegenerative diseases (NDs), typically increasing in prevalence with age, and is a major risk factor for developing neurodegeneration later in life. While our understanding of genes and pathways that underlie neurotoxicity in specific NDs has advanced, we still lack a complete understanding of early molecular and physiological changes that drive neurodegeneration, particularly as an individual ages following a TBI. Recently Drosophila has been introduced as a model organism for studying closed-head TBI. In this paper, we deliver a TBI to flies early in adult life, and then measure molecular and physiological phenotypes at short-, mid-, and long-term timepoints following the injury. We aim to identify the timing of changes that contribute to neurodegeneration. Here we confirm prior work demonstrating a TBI-induced decline in lifespan, and present evidence of a progressive decline in locomotor function, robust acute and modest chronic neuroinflammation, and a late-onset increase in protein aggregation. We also present evidence of metabolic dysfunction, in the form of starvation sensitivity and decreased lipids, that persists beyond the immediate injury response, but does not differ long-term. An intervention of dietary restriction (DR) partially ameliorates some TBI-induced phenotypes, including lifespan and locomotor function, though it does not alter the pattern of starvation sensitivity of injured flies. In the future, molecular pathways identified as altered following TBI—particularly in the short-, or mid-term—could present potential therapeutic targets.
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Affiliation(s)
- Rebecca Delventhal
- Department of Biology, Lake Forest College, Lake Forest, IL, 60045, USA.
| | - Emily R Wooder
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Maylis Basturk
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Mohima Sattar
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Jonathan Lai
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Danielle Bolton
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Gayathri Muthukumar
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Matthew Ulgherait
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Mimi M Shirasu-Hiza
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, 10032, USA.
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13
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Stuart BAR, Franitza AL, E L. Regulatory Roles of Antimicrobial Peptides in the Nervous System: Implications for Neuronal Aging. Front Cell Neurosci 2022; 16:843790. [PMID: 35321204 PMCID: PMC8936185 DOI: 10.3389/fncel.2022.843790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 01/31/2022] [Indexed: 12/12/2022] Open
Abstract
Antimicrobial peptides (AMPs) are classically known as important effector molecules in innate immunity across all multicellular organisms. However, emerging evidence begins to suggest multifunctional properties of AMPs beyond their antimicrobial activity, surprisingly including their roles in regulating neuronal function, such as sleep and memory formation. Aging, which is fundamental to neurodegeneration in both physiological and disease conditions, interestingly affects the expression pattern of many AMPs in an infection-independent manner. While it remains unclear whether these are coincidental events, or a mechanistic relationship exists, previous studies have suggested a close link between AMPs and a few key proteins involved in neurodegenerative diseases. This review discusses recent literature and advances in understanding the crosstalk between AMPs and the nervous system at both molecular and functional levels, with the aim to explore how AMPs may relate to neuronal vulnerability in aging.
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Affiliation(s)
- Bradey A. R. Stuart
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Ariel L. Franitza
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Lezi E
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, United States
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States
- *Correspondence: Lezi E
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14
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Aggarwal P, Thapliyal D, Sarkar S. The past and present of Drosophila models of Traumatic Brain Injury. J Neurosci Methods 2022; 371:109533. [DOI: 10.1016/j.jneumeth.2022.109533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 11/30/2022]
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15
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Ketogenic diet reduces early mortality following traumatic brain injury in Drosophila via the PPARγ ortholog Eip75B. PLoS One 2021; 16:e0258873. [PMID: 34699541 PMCID: PMC8547619 DOI: 10.1371/journal.pone.0258873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 10/06/2021] [Indexed: 11/19/2022] Open
Abstract
Traumatic brain injury (TBI) is a common neurological disorder whose outcomes vary widely depending on a variety of environmental factors, including diet. Using a Drosophila melanogaster TBI model that reproduces key aspects of TBI in humans, we previously found that the diet consumed immediately following a primary brain injury has a substantial effect on the incidence of mortality within 24 h (early mortality). Flies that receive equivalent primary injuries have a higher incidence of early mortality when fed high-carbohydrate diets versus water. Here, we report that flies fed high-fat ketogenic diet (KD) following TBI exhibited early mortality that was equivalent to that of flies fed water and that flies protected from early mortality by KD continued to show survival benefits weeks later. KD also has beneficial effects in mammalian TBI models, indicating that the mechanism of action of KD is evolutionarily conserved. To probe the mechanism, we examined the effect of KD in flies mutant for Eip75B, an ortholog of the transcription factor PPARγ (peroxisome proliferator-activated receptor gamma) that contributes to the mechanism of action of KD and has neuroprotective effects in mammalian TBI models. We found that the incidence of early mortality of Eip75B mutant flies was higher when they were fed KD than when they were fed water following TBI. These data indicate that Eip75B/PPARγ is necessary for the beneficial effects of KD following TBI. In summary, this work provides the first evidence that KD activates PPARγ to reduce deleterious outcomes of TBI and it demonstrates the utility of the fly TBI model for dissecting molecular pathways that contribute to heterogeneity in TBI outcomes.
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16
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Buhlman LM, Krishna G, Jones TB, Thomas TC. Drosophila as a model to explore secondary injury cascades after traumatic brain injury. Biomed Pharmacother 2021; 142:112079. [PMID: 34463269 PMCID: PMC8458259 DOI: 10.1016/j.biopha.2021.112079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/14/2022] Open
Abstract
Drosophilae are emerging as a valuable model to study traumatic brain injury (TBI)-induced secondary injury cascades that drive persisting neuroinflammation and neurodegenerative pathology that imposes significant risk for long-term neurological deficits. As in mammals, TBI in Drosophila triggers axonal injury, metabolic crisis, oxidative stress, and a robust innate immune response. Subsequent neurodegeneration stresses quality control systems and perpetuates an environment for neuroprotection, regeneration, and delayed cell death via highly conserved cell signaling pathways. Fly injury models continue to be developed and validated for both whole-body and head-specific injury to isolate, evaluate, and modulate these parallel pathways. In conjunction with powerful genetic tools, the ability for longitudinal evaluation, and associated neurological deficits that can be tested with established behavioral tasks, Drosophilae are an attractive model to explore secondary injury cascades and therapeutic intervention after TBI. Here, we review similarities and differences between mammalian and fly pathophysiology and highlight strategies for their use in translational neurotrauma research.
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Affiliation(s)
- Lori M Buhlman
- Biomedical Sciences Program, Midwestern University, Glendale, AZ, USA.
| | - Gokul Krishna
- Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA; Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA
| | - T Bucky Jones
- Department of Anatomy, Midwestern University, Glendale, AZ, USA
| | - Theresa Currier Thomas
- Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA; Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA; Phoenix VA Health Care System, Phoenix, AZ, USA.
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17
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Shah EJ, Hüttemann M, Sanderson TH, Gurdziel K, Ruden DM. Inhibiting Mitochondrial Cytochrome c Oxidase Downregulates Gene Transcription After Traumatic Brain Injury in Drosophila. Front Physiol 2021; 12:628777. [PMID: 33790803 PMCID: PMC8005633 DOI: 10.3389/fphys.2021.628777] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/23/2021] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injuries (TBIs) caused by a sudden impact to the head alter behavior and impair physical and cognitive function. Besides the severity, type and area of the brain affected, the outcome of TBI is also influenced by the patient’s biological sex. Previous studies reporting mitochondrial dysfunction mainly focused on exponential reactive oxygen species (ROS) generation, increased mitochondrial membrane potential, and altered mitochondrial dynamics as a key player in the outcome to brain injury. In this study, we evaluated the effect of a near-infrared (NIR) light exposure on gene expression in a Drosophila TBI model. NIR interacts with cytochrome c oxidase (COX) of the electron transport chain to reduce mitochondrial membrane potential hyperpolarization, attenuate ROS generation, and apoptosis. We subjected w1118 male and female flies to TBI using a high-impact trauma (HIT) device and subsequently exposed the isolated fly brains to a COX-inhibitory wavelength of 750 nm for 2 hours (hr). Genome-wide 3′-mRNA-sequencing of fly brains revealed that injured w1118 females exhibit greater changes in transcription compared to males at 1, 2, and 4 hours (hr) after TBI. Inhibiting COX by exposure to NIR downregulates gene expression in injured females but has minimal effect in injured males. Our results suggest that mitochondrial COX modulation with NIR alters gene expression in Drosophila following TBI and the response to injury and NIR exposure varies by biological sex.
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Affiliation(s)
- Ekta J Shah
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, United States
| | - Thomas H Sanderson
- Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Katherine Gurdziel
- Office of the Vice President of Research, Wayne State University, Detroit, MI, United States
| | - Douglas M Ruden
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States.,Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, United States.,Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States
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18
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Willes AM, Krcmarik TR, Daughtry AE, Brusich DJ. Repetitive mild traumatic brain injury causes synergistic effects on mortality. MICROPUBLICATION BIOLOGY 2021; 2021:10.17912/micropub.biology.000356. [PMID: 33474534 PMCID: PMC7812388 DOI: 10.17912/micropub.biology.000356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Repetitive mild TBI (rmTBI) events are common in the U.S. However, rmTBI is challenging to study and this contributes to a poor understanding of mechanistic bases for disease following these injuries. We used fruit flies (D. melanogaster) and a modified version of the high-impact trauma (HIT) method of TBI to assess the pattern of mortality observed after rmTBI. We found that the pattern of mortality was synergistic after a critical number of injuries, similar to that observed previously at more moderate levels of TBI severity. The identity of cellular and molecular factors which contribute to the synergistic effect on mortality remain unknown, but this model offers a platform for investigation into such factors.
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Affiliation(s)
| | | | | | - Douglas J Brusich
- University of Wisconsin - Green Bay, Green Bay, WI USA,
Correspondence to: Douglas J Brusich ()
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19
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Swanson LC, Trujillo EA, Thiede GH, Katzenberger RJ, Shishkova E, Coon JJ, Ganetzky B, Wassarman DA. Survival Following Traumatic Brain Injury in Drosophila Is Increased by Heterozygosity for a Mutation of the NF-κB Innate Immune Response Transcription Factor Relish. Genetics 2020; 216:1117-1136. [PMID: 33109529 PMCID: PMC7768241 DOI: 10.1534/genetics.120.303776] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/26/2020] [Indexed: 12/16/2022] Open
Abstract
Traumatic brain injury (TBI) pathologies are caused by primary and secondary injuries. Primary injuries result from physical damage to the brain, and secondary injuries arise from cellular responses to primary injuries. A characteristic cellular response is sustained activation of inflammatory pathways commonly mediated by nuclear factor-κB (NF-κB) transcription factors. Using a Drosophila melanogaster TBI model, we previously found that the main proximal transcriptional response to primary injuries is triggered by activation of Toll and Imd innate immune response pathways that engage NF-κB factors Dif and Relish (Rel), respectively. Here, we found by mass spectrometry that Rel protein level increased in fly heads at 4-8 hr after TBI. To investigate the necessity of Rel for secondary injuries, we generated a null allele, Reldel , by CRISPR/Cas9 editing. When heterozygous but not homozygous, the Reldel mutation reduced mortality at 24 hr after TBI and increased the lifespan of injured flies. Additionally, the effect of heterozygosity for Reldel on mortality was modulated by genetic background and diet. To identify genes that facilitate effects of Reldel on TBI outcomes, we compared genome-wide mRNA expression profiles of uninjured and injured +/+, +/Reldel , and Reldel /Reldel flies at 4 hr following TBI. Only a few genes changed expression more than twofold in +/Reldel flies relative to +/+ and Reldel /Reldel flies, and they were not canonical innate immune response genes. Therefore, Rel is necessary for TBI-induced secondary injuries but in complex ways involving Rel gene dose, genetic background, diet, and possibly small changes in expression of innate immune response genes.
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Affiliation(s)
- Laura C Swanson
- Department of Medical Genetics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706
- Medical Scientist Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Edna A Trujillo
- Department of Chemistry, College of Letters & Science, University of Wisconsin-Madison, Madison, Wisconsin 53706
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Gene H Thiede
- Department of Medical Genetics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Rebeccah J Katzenberger
- Department of Medical Genetics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Evgenia Shishkova
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, Wisconsin 53706
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Joshua J Coon
- Department of Chemistry, College of Letters & Science, University of Wisconsin-Madison, Madison, Wisconsin 53706
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, Wisconsin 53706
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706
- Morgridge Institute for Research, Madison, Wisconsin 53706
| | - Barry Ganetzky
- Department of Genetics, College of Agricultural and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - David A Wassarman
- Department of Medical Genetics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706
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