1
|
Brantley SE, Stouthamer CM, Kr P, Fischer ML, Hill J, Schlenke TA, Mortimer NT. Host JAK-STAT activity is a target of parasitoid wasp virulence strategies. PLoS Pathog 2024; 20:e1012349. [PMID: 38950076 PMCID: PMC11244843 DOI: 10.1371/journal.ppat.1012349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 07/12/2024] [Accepted: 06/17/2024] [Indexed: 07/03/2024] Open
Abstract
Innate immune responses that allow hosts to survive infection depend on the action of multiple conserved signaling pathways. Pathogens and parasites in turn have evolved virulence factors to target these immune signaling pathways in an attempt to overcome host immunity. Consequently, the interactions between host immune molecules and pathogen virulence factors play an important role in determining the outcome of an infection. The immune responses of Drosophila melanogaster provide a valuable model to understand immune signaling and host-pathogen interactions. Flies are commonly infected by parasitoid wasps and mount a coordinated cellular immune response following infection. This response is characterized by the production of specialized blood cells called lamellocytes that form a tight capsule around wasp eggs in the host hemocoel. The conserved JAK-STAT signaling pathway has been implicated in lamellocyte proliferation and is required for successful encapsulation of wasp eggs. Here we show that activity of Stat92E, the D. melanogaster STAT ortholog, is induced in immune tissues following parasitoid infection. Virulent wasp species are able to suppress Stat92E activity during infection, suggesting they target JAK-STAT pathway activation as a virulence strategy. Furthermore, two wasp species (Leptopilina guineaensis and Ganaspis xanthopoda) suppress phenotypes associated with a gain-of-function mutation in hopscotch, the D. melanogaster JAK ortholog, indicating that they inhibit the activity of the core signaling components of the JAK-STAT pathway. Our data suggest that parasitoid wasp virulence factors block JAK-STAT signaling to overcome fly immune defenses.
Collapse
Affiliation(s)
- Susanna E Brantley
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Corinne M Stouthamer
- Department of Entomology, University of Arizona, Tucson, Arizona, United States of America
| | - Pooja Kr
- School of Biological Sciences, Illinois State University, Normal, Illinois, United States of America
| | - Mary L Fischer
- School of Biological Sciences, Illinois State University, Normal, Illinois, United States of America
| | - Joshua Hill
- School of Biological Sciences, Illinois State University, Normal, Illinois, United States of America
| | - Todd A Schlenke
- Department of Entomology, University of Arizona, Tucson, Arizona, United States of America
| | - Nathan T Mortimer
- School of Biological Sciences, Illinois State University, Normal, Illinois, United States of America
- Department of Biochemistry & Biophysics, Oregon State University, Corvallis, Oregon, United States of America
| |
Collapse
|
2
|
Garza AB, Garcia R, Solis LM, Halfon MS, Girgis HZ. EnhancerTracker: Comparing cell-type-specific enhancer activity of DNA sequence triplets via an ensemble of deep convolutional neural networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.23.573198. [PMID: 38187673 PMCID: PMC10769370 DOI: 10.1101/2023.12.23.573198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Motivation Transcriptional enhancers - unlike promoters - are unrestrained by distance or strand orientation with respect to their target genes, making their computational identification a challenge. Further, there are insufficient numbers of confirmed enhancers for many cell types, preventing robust training of machine-learning-based models for enhancer prediction for such cell types. Results We present EnhancerTracker , a novel tool that leverages an ensemble of deep separable convolutional neural networks to identify cell-type-specific enhancers with the need of only two confirmed enhancers. EnhancerTracker is trained, validated, and tested on 52,789 putative enhancers obtained from the FANTOM5 Project and control sequences derived from the human genome. Unlike available tools, which accept one sequence at a time, the input to our tool is three sequences; the first two are enhancers active in the same cell type. EnhancerTracker outputs 1 if the third sequence is an enhancer active in the same cell type(s) where the first two enhancers are active. It outputs 0 otherwise. On a held-out set (15%), EnhancerTracker achieved an accuracy of 64%, a specificity of 93%, a recall of 35%, a precision of 84%, and an F1 score of 49%. Availability and implementation https://github.com/BioinformaticsToolsmith/EnhancerTracker. Contact hani.girgis@tamuk.edu.
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Chung HL, Ye Q, Park YJ, Zuo Z, Mok JW, Kanca O, Tattikota SG, Lu S, Perrimon N, Lee HK, Bellen HJ. Very-long-chain fatty acids induce glial-derived sphingosine-1-phosphate synthesis, secretion, and neuroinflammation. Cell Metab 2023; 35:855-874.e5. [PMID: 37084732 PMCID: PMC10160010 DOI: 10.1016/j.cmet.2023.03.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 01/10/2023] [Accepted: 03/29/2023] [Indexed: 04/23/2023]
Abstract
VLCFAs (very-long-chain fatty acids) are the most abundant fatty acids in myelin. Hence, during demyelination or aging, glia are exposed to higher levels of VLCFA than normal. We report that glia convert these VLCFA into sphingosine-1-phosphate (S1P) via a glial-specific S1P pathway. Excess S1P causes neuroinflammation, NF-κB activation, and macrophage infiltration into the CNS. Suppressing the function of S1P in fly glia or neurons, or administration of Fingolimod, an S1P receptor antagonist, strongly attenuates the phenotypes caused by excess VLCFAs. In contrast, elevating the VLCFA levels in glia and immune cells exacerbates these phenotypes. Elevated VLCFA and S1P are also toxic in vertebrates based on a mouse model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). Indeed, reducing VLCFA with bezafibrate ameliorates the phenotypes. Moreover, simultaneous use of bezafibrate and fingolimod synergizes to improve EAE, suggesting that lowering VLCFA and S1P is a treatment avenue for MS.
Collapse
Affiliation(s)
- Hyung-Lok Chung
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Qi Ye
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Department of Pediatrics, Section of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ye-Jin Park
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jung-Wan Mok
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | | | - Shenzhao Lu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Nobert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA; Howard Hughes Medical Institute and Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Hyun Kyoung Lee
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Department of Pediatrics, Section of Neurology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA.
| |
Collapse
|
5
|
Kanwal A, Joshi PV, Mandal S, Mandal L. Ubx-Collier signaling cascade maintains blood progenitors in the posterior lobes of the Drosophila larval lymph gland. PLoS Genet 2021; 17:e1009709. [PMID: 34370733 PMCID: PMC8376192 DOI: 10.1371/journal.pgen.1009709] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 08/19/2021] [Accepted: 07/12/2021] [Indexed: 12/02/2022] Open
Abstract
Drosophila larval hematopoiesis occurs in a specialized multi-lobed organ called the lymph gland. Extensive characterization of the organ has provided mechanistic insights into events related to developmental hematopoiesis. Spanning from the thoracic to the abdominal segment of the larvae, this organ comprises a pair of primary, secondary, and tertiary lobes. Much of our understanding arises from the studies on the primary lobe, while the secondary and tertiary lobes have remained mostly unexplored. Previous studies have inferred that these lobes are composed of progenitors that differentiate during pupation; however, the mechanistic basis of this extended progenitor state remains unclear. This study shows that posterior lobe progenitors are maintained by a local signaling center defined by Ubx and Collier in the tertiary lobe. This Ubx zone in the tertiary lobe shares several markers with the niche of the primary lobe. Ubx domain regulates the homeostasis of the posterior lobe progenitors in normal development and an immune-challenged scenario. Our study establishes the lymph gland as a model to tease out how the progenitors interface with the dual niches within an organ during development and disorders.
Collapse
Affiliation(s)
- Aditya Kanwal
- Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Pranav Vijay Joshi
- Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Sudip Mandal
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Lolitika Mandal
- Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| |
Collapse
|
6
|
Yu S, Luo F, Jin LH. Rab5 and Rab11 maintain hematopoietic homeostasis by restricting multiple signaling pathways in Drosophila. eLife 2021; 10:60870. [PMID: 33560224 PMCID: PMC7891935 DOI: 10.7554/elife.60870] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 02/08/2021] [Indexed: 12/26/2022] Open
Abstract
The hematopoietic system of Drosophila is a powerful genetic model for studying hematopoiesis, and vesicle trafficking is important for signal transduction during various developmental processes; however, its interaction with hematopoiesis is currently largely unknown. In this article, we selected three endosome markers, Rab5, Rab7, and Rab11, that play a key role in membrane trafficking and determined whether they participate in hematopoiesis. Inhibiting Rab5 or Rab11 in hemocytes or the cortical zone (CZ) significantly induced cell overproliferation and lamellocyte formation in circulating hemocytes and lymph glands and disrupted blood cell progenitor maintenance. Lamellocyte formation involves the JNK, Toll, and Ras/EGFR signaling pathways. Notably, lamellocyte formation was also associated with JNK-dependent autophagy. In conclusion, we identified Rab5 and Rab11 as novel regulators of hematopoiesis, and our results advance the understanding of the mechanisms underlying the maintenance of hematopoietic homeostasis as well as the pathology of blood disorders such as leukemia.
Collapse
Affiliation(s)
- Shichao Yu
- Department of Genetics, College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Fangzhou Luo
- Department of Genetics, College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Li Hua Jin
- Department of Genetics, College of Life Sciences, Northeast Forestry University, Harbin, China
| |
Collapse
|
7
|
Tiwari SK, Toshniwal AG, Mandal S, Mandal L. Fatty acid β-oxidation is required for the differentiation of larval hematopoietic progenitors in Drosophila. eLife 2020; 9:53247. [PMID: 32530419 PMCID: PMC7347386 DOI: 10.7554/elife.53247] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 06/11/2020] [Indexed: 12/12/2022] Open
Abstract
Cell-intrinsic and extrinsic signals regulate the state and fate of stem and progenitor cells. Recent advances in metabolomics illustrate that various metabolic pathways are also important in regulating stem cell fate. However, our understanding of the metabolic control of the state and fate of progenitor cells is in its infancy. Using Drosophila hematopoietic organ: lymph gland, we demonstrate that Fatty Acid Oxidation (FAO) is essential for the differentiation of blood cell progenitors. In the absence of FAO, the progenitors are unable to differentiate and exhibit altered histone acetylation. Interestingly, acetate supplementation rescues both histone acetylation and the differentiation defects. We further show that the CPT1/whd (withered), the rate-limiting enzyme of FAO, is transcriptionally regulated by Jun-Kinase (JNK), which has been previously implicated in progenitor differentiation. Our study thus reveals how the cellular signaling machinery integrates with the metabolic cue to facilitate the differentiation program. Stem cells are special precursor cells, found in all animals from flies to humans, that can give rise to all the mature cell types in the body. Their job is to generate supplies of new cells wherever these are needed. This is important because it allows damaged or worn-out tissues to be repaired and replaced by fresh, healthy cells. As part of this renewal process, stem cells generate pools of more specialized cells, called progenitor cells. These can be thought of as half-way to maturation and can only develop in a more restricted number of ways. For example, so-called myeloid progenitor cells from humans can only develop into a specific group of blood cell types, collectively termed the myeloid lineage. Fruit flies, like many other animals, also have several different types of blood cells. The fly’s repertoire of blood cells is very similar to the human myeloid lineage, and these cells also develop from the fly equivalent of myeloid progenitor cells. These progenitors are found in a specialized organ in fruit fly larvae called the lymph gland, where the blood forms. These similarities between fruit flies and humans mean that flies are a good model to study how myeloid progenitor cells mature. A lot is already known about the molecules that signal to progenitor cells how and when to mature. However, the role of metabolism – the chemical reactions that process nutrients and provide energy inside cells – is still poorly understood. Tiwari et al. set out to identify which metabolic reactions myeloid progenitor cells require and how these reactions might shape the progenitors’ development into mature blood cells. The experiments in this study used fruit fly larvae that had been genetically altered so that they could no longer perform key chemical reactions needed for the breakdown of fats. In these mutant larvae, the progenitors within the lymph gland could not give rise to mature blood cells. This showed that myeloid progenitor cells need to be able to break down fats in order to develop properly. These results highlight a previously unappreciated role for metabolism in controlling the development of progenitor cells. If this effect also occurs in humans, this knowledge could one day help medical researchers engineer replacement tissues in the lab, or even increase our own bodies’ ability to regenerate blood, and potentially other organs.
Collapse
Affiliation(s)
- Satish Kumar Tiwari
- Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Ashish Ganeshlalji Toshniwal
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Sudip Mandal
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Lolitika Mandal
- Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| |
Collapse
|
8
|
Tattikota SG, Cho B, Liu Y, Hu Y, Barrera V, Steinbaugh MJ, Yoon SH, Comjean A, Li F, Dervis F, Hung RJ, Nam JW, Ho Sui S, Shim J, Perrimon N. A single-cell survey of Drosophila blood. eLife 2020; 9:e54818. [PMID: 32396065 PMCID: PMC7237219 DOI: 10.7554/elife.54818] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 05/08/2020] [Indexed: 12/30/2022] Open
Abstract
Drosophila blood cells, called hemocytes, are classified into plasmatocytes, crystal cells, and lamellocytes based on the expression of a few marker genes and cell morphologies, which are inadequate to classify the complete hemocyte repertoire. Here, we used single-cell RNA sequencing (scRNA-seq) to map hemocytes across different inflammatory conditions in larvae. We resolved plasmatocytes into different states based on the expression of genes involved in cell cycle, antimicrobial response, and metabolism together with the identification of intermediate states. Further, we discovered rare subsets within crystal cells and lamellocytes that express fibroblast growth factor (FGF) ligand branchless and receptor breathless, respectively. We demonstrate that these FGF components are required for mediating effective immune responses against parasitoid wasp eggs, highlighting a novel role for FGF signaling in inter-hemocyte crosstalk. Our scRNA-seq analysis reveals the diversity of hemocytes and provides a rich resource of gene expression profiles for a systems-level understanding of their functions.
Collapse
Affiliation(s)
| | - Bumsik Cho
- Department of Life Science, Hanyang UniversitySeoulRepublic of Korea
| | - Yifang Liu
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Yanhui Hu
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | | | | | - Sang-Ho Yoon
- Department of Life Science, Hanyang UniversitySeoulRepublic of Korea
| | - Aram Comjean
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Fangge Li
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Franz Dervis
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Ruei-Jiun Hung
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Jin-Wu Nam
- Department of Life Science, Hanyang UniversitySeoulRepublic of Korea
| | | | - Jiwon Shim
- Department of Life Science, Hanyang UniversitySeoulRepublic of Korea
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
- Howard Hughes Medical InstituteBostonUnited States
| |
Collapse
|
9
|
CCAP regulates feeding behavior via the NPF pathway in Drosophila adults. Proc Natl Acad Sci U S A 2020; 117:7401-7408. [PMID: 32179671 DOI: 10.1073/pnas.1914037117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The intake of macronutrients is crucial for the fitness of any animal and is mainly regulated by peripheral signals to the brain. How the brain receives and translates these peripheral signals or how these interactions lead to changes in feeding behavior is not well-understood. We discovered that 2 crustacean cardioactive peptide (CCAP)-expressing neurons in Drosophila adults regulate feeding behavior and metabolism. Notably, loss of CCAP, or knocking down the CCAP receptor (CCAP-R) in 2 dorsal median neurons, inhibits the release of neuropeptide F (NPF), which regulates feeding behavior. Furthermore, under starvation conditions, flies normally have an increased sensitivity to sugar; however, loss of CCAP, or CCAP-R in 2 dorsal median NPF neurons, inhibited sugar sensitivity in satiated and starved flies. Separate from its regulation of NPF signaling, the CCAP peptide also regulates triglyceride levels. Additionally, genetic and optogenetic studies demonstrate that CCAP signaling is necessary and sufficient to stimulate a reflexive feeding behavior, the proboscis extension reflex (PER), elicited when external food cues are interpreted as palatable. Dopaminergic signaling was also sufficient to induce a PER. On the other hand, although necessary, NPF neurons were not able to induce a PER. These data illustrate that the CCAP peptide is a central regulator of feeding behavior and metabolism in adult flies, and that NPF neurons have an important regulatory role within this system.
Collapse
|
10
|
Tomoyasu Y, Halfon MS. How to study enhancers in non-traditional insect models. ACTA ACUST UNITED AC 2020; 223:223/Suppl_1/jeb212241. [PMID: 32034049 DOI: 10.1242/jeb.212241] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Transcriptional enhancers are central to the function and evolution of genes and gene regulation. At the organismal level, enhancers play a crucial role in coordinating tissue- and context-dependent gene expression. At the population level, changes in enhancers are thought to be a major driving force that facilitates evolution of diverse traits. An amazing array of diverse traits seen in insect morphology, physiology and behavior has been the subject of research for centuries. Although enhancer studies in insects outside of Drosophila have been limited, recent advances in functional genomic approaches have begun to make such studies possible in an increasing selection of insect species. Here, instead of comprehensively reviewing currently available technologies for enhancer studies in established model organisms such as Drosophila, we focus on a subset of computational and experimental approaches that are likely applicable to non-Drosophila insects, and discuss the pros and cons of each approach. We discuss the importance of validating enhancer function and evaluate several possible validation methods, such as reporter assays and genome editing. Key points and potential pitfalls when establishing a reporter assay system in non-traditional insect models are also discussed. We close with a discussion of how to advance enhancer studies in insects, both by improving computational approaches and by expanding the genetic toolbox in various insects. Through these discussions, this Review provides a conceptual framework for studying the function and evolution of enhancers in non-traditional insect models.
Collapse
Affiliation(s)
| | - Marc S Halfon
- Department of Biochemistry, University at Buffalo-State University of New York, Buffalo, NY 14203, USA
| |
Collapse
|
11
|
Kwon SY, Massey K, Watson MA, Hussain T, Volpe G, Buckley CD, Nicolaou A, Badenhorst P. Oxidised metabolites of the omega-6 fatty acid linoleic acid activate dFOXO. Life Sci Alliance 2020; 3:3/2/e201900356. [PMID: 31992650 PMCID: PMC6988086 DOI: 10.26508/lsa.201900356] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 01/04/2023] Open
Abstract
Obesity-induced inflammation, or meta-inflammation, plays key roles in metabolic syndrome and is a significant risk factor in diabetes and cardiovascular disease. To investigate causal links between obesity, meta-inflammation, and insulin signaling we established a Drosophila model to determine how elevated dietary fat and changes in the levels and balance of saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) influence inflammation. We observe negligible effect of saturated fatty acid on inflammation but marked enhancement or suppression by omega-6 and omega-3 PUFAs, respectively. Using combined lipidomic and genetic analysis, we show omega-6 PUFA enhances meta-inflammation by producing linoleic acid-derived lipid mediator 9-hydroxy-octadecadienoic acid (9-HODE). Transcriptome analysis reveals 9-HODE functions by regulating FOXO family transcription factors. We show 9-HODE activates JNK, triggering FOXO nuclear localisation and chromatin binding. FOXO TFs are important transducers of the insulin signaling pathway that are normally down-regulated by insulin. By activating FOXO, 9-HODE could antagonise insulin signaling providing a molecular conduit linking changes in dietary fatty acid balance, meta-inflammation, and insulin resistance.
Collapse
Affiliation(s)
- So Yeon Kwon
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, UK
| | - Karen Massey
- Bradford School of Pharmacy, University of Bradford, Bradford, UK
| | - Mark A Watson
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, UK
| | - Tayab Hussain
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, UK
| | - Giacomo Volpe
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, UK
| | - Christopher D Buckley
- Institute of Inflammation and Ageing, Centre for Translational Inflammation Research, Queen Elizabeth Hospital, Edgbaston, UK.,Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK
| | - Anna Nicolaou
- Bradford School of Pharmacy, University of Bradford, Bradford, UK.,Laboratory for Lipidomics and Lipid Biology, Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, Manchester, UK
| | - Paul Badenhorst
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, UK
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Tokusumi Y, Tokusumi T, Schulz RA. Mechanical stress to Drosophila larvae stimulates a cellular immune response through the JAK/STAT signaling pathway. Biochem Biophys Res Commun 2018; 502:415-421. [DOI: 10.1016/j.bbrc.2018.05.192] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 05/28/2018] [Indexed: 11/27/2022]
|
14
|
Yu S, Luo F, Jin LH. The Drosophila lymph gland is an ideal model for studying hematopoiesis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 83:60-69. [PMID: 29191551 DOI: 10.1016/j.dci.2017.11.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 10/30/2017] [Accepted: 11/26/2017] [Indexed: 06/07/2023]
Abstract
Hematopoiesis in Drosophila melanogaster occurs throughout the entire life cycle, from the embryo to adulthood. The healthy lymph gland, as a hematopoietic organ during the larval stage, can give rise to two mature types of hemocytes, plasmatocytes and crystal cells, which persist into the pupal and adult stages. Homeostasis of the lymph gland is tightly controlled by a series of conserved factors and signaling pathways, which also play key roles in mammalian hematopoiesis. Thus, revealing the hematopoietic mechanisms in Drosophila will advance our understanding of hematopoietic stem cells and their niche as well as leukemia in mammals. In addition, the lymph gland employs a battery of strategies to produce lamellocytes, another type of mature hemocyte, to fight against parasitic wasp eggs, making the lymph gland an important immunological organ. In this review, the developmental process of the lymph gland and the regulatory networks of hematopoiesis are summarized. Moreover, we outline the current knowledge and novel insight into homeostasis of the lymph gland.
Collapse
Affiliation(s)
- Shichao Yu
- Department of Genetics, College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Fangzhou Luo
- Department of Genetics, College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Li Hua Jin
- Department of Genetics, College of Life Sciences, Northeast Forestry University, Harbin, China.
| |
Collapse
|
15
|
Tokusumi T, Tokusumi Y, Schulz RA. The mir-7 and bag of marbles genes regulate Hedgehog pathway signaling in blood cell progenitors in Drosophila larval lymph glands. Genesis 2018; 56:e23210. [PMID: 29663653 DOI: 10.1002/dvg.23210] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/05/2018] [Accepted: 04/05/2018] [Indexed: 01/03/2023]
Abstract
Hedgehog (Hh) pathway signaling is crucial for the maintenance of blood cell progenitors in the lymph gland hematopoietic organ present in Drosophila third instar larvae. Previous studies from our lab have likewise shown the importance of the mir-7 and bag of marbles (bam) genes in maintaining the progenitor state. Thus, we sought to investigate a possible interaction between the Hh pathway and mir-7/bam in the prohemocyte population within this hematopoietic tissue. Gain of function mir-7 was able to rescue a blood cell progenitor depletion phenotype caused by Patched (Ptc) inhibition of Hh pathway signaling in these cells. Similarly, expression of a dominant/negative version of Ptc was able to rescue the severe reduction of prohemocytes due to bam loss of function. Furthermore, we demonstrated that Suppressor of fused [Su(fu)], another known inhibitor of Hh signaling, likely serves as a translational repression target of the mir-7 miRNA. Our results suggest the mir-7/bam combination regulates the Hh signaling network through repression of Su(fu) to maintain hemocyte progenitors in the larval lymph gland.
Collapse
Affiliation(s)
- Tsuyoshi Tokusumi
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
| | - Yumiko Tokusumi
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
| | - Robert A Schulz
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
| |
Collapse
|
16
|
Tokusumi Y, Tokusumi T, Schulz RA. The nociception genes painless and Piezo are required for the cellular immune response of Drosophila larvae to wasp parasitization. Biochem Biophys Res Commun 2017; 486:893-897. [PMID: 28342875 DOI: 10.1016/j.bbrc.2017.03.116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 03/21/2017] [Indexed: 12/23/2022]
Abstract
In vertebrates, interaction between the nervous system and immune system is important to protect a challenged host from stress inputs from external sources. In this study, we demonstrate that sensory neurons are involved in the cellular immune response elicited by wasp infestation of Drosophila larvae. Multidendritic class IV neurons sense contacts from external stimuli and induce avoidance behaviors for host defense. Our findings show that inactivation of these sensory neurons impairs the cellular response against wasp parasitization. We also demonstrate that the nociception genes encoding the mechanosensory receptors Painless and Piezo, both expressed in class IV neurons, are essential for the normal cellular immune response to parasite challenge.
Collapse
Affiliation(s)
- Yumiko Tokusumi
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Tsuyoshi Tokusumi
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Robert A Schulz
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
| |
Collapse
|