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Hong TT, Hu F, Ge WJ, Zhang R, Du J, Thakur K, Tang SM, Wei ZJ. Selenium Treatment Alleviates the Inhibition Caused by Nep-L Gene Knockdown in Silkworm (Bombyx mori). Biol Trace Elem Res 2024:10.1007/s12011-024-04248-8. [PMID: 38819778 DOI: 10.1007/s12011-024-04248-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 05/25/2024] [Indexed: 06/01/2024]
Abstract
Recent studies have emphasized the beneficial effects of 50 μM selenium (Se) on the growth and development of the silkworm, Bombyx mori; however, less is known about its underlying mechanism. To unravel the effect of 50 μM Se on the silkworms with neutral endopeptidase 24.11-like gene (NEP-L) knockdown, we injected small interfering RNA (siRNA) into the body cavity of silkworms. Phenotypic characteristics, mRNA expression of the Nep-L gene, and enriched Se content were evaluated in silkworms from each treatment group. After injecting Nep-L siRNA, the body weight, cocoon quality (cocoon weight, cocoon shell weight, and cocoon shell ratio), and egg production of silkworms were significantly reduced, without any significant effect on egg laying number. However, Se treatment could significantly alleviate the inhibition of body weight, and cocoon quality, without significant effects on egg laying number and production. In addition, the gene knockdown increased Se content in the B. mori. On the molecular level, the targeted Nep-L gene was inhibited significantly by siRNA interference, essentially with the strongest effect at 24 h after RNAi, followed by steady recovery. Among the three fragments, the siRNA of Nep-L-3 was the most effective in interfering with target gene expression. Nep-L gene showed the highest expression in Malpighian tubules (MTs). Both at the phenotypic and genotypic levels, our results show that Nep-L knockdown can exert a significant inhibitory effect on silkworms, and 50 μM Se can reverse the negative effect, which provides a practical prospect for strengthening the silkworm food industry.
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Affiliation(s)
- Ting-Ting Hong
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, PR China
| | - Fei Hu
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, PR China.
- School of Biological Science and Engineering, North Minzu University, Yinchuan, 750021, People's Republic of China.
| | - Wen-Jie Ge
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, PR China
| | - Rui Zhang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, PR China
| | - Juan Du
- School of Biological Science and Engineering, North Minzu University, Yinchuan, 750021, People's Republic of China
| | - Kiran Thakur
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, PR China
- School of Biological Science and Engineering, North Minzu University, Yinchuan, 750021, People's Republic of China
| | - Shun-Ming Tang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212003, PR China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, PR China
| | - Zhao-Jun Wei
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, PR China.
- School of Biological Science and Engineering, North Minzu University, Yinchuan, 750021, People's Republic of China.
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Buhr A, Schiemann R, Meyer H. Neprilysin 4: an essential peptidase with multifaceted physiological relevance. Biol Chem 2023; 404:513-520. [PMID: 36653344 DOI: 10.1515/hsz-2022-0286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023]
Abstract
Neprilysins are highly conserved ectoenzymes that hydrolyze and thus inactivate signaling peptides in the extracellular space. Herein, we focus on Neprilysin 4 from Drosophila melanogaster and evaluate the existing knowledge on the physiological relevance of the peptidase. Particular attention is paid to the role of the neprilysin in regulating feeding behavior and the expression of insulin-like peptides in the central nervous system. In addition, we assess the function of the peptidase in controlling the activity of the sarcoplasmic and endoplasmic reticulum Ca2+ ATPase in myocytes, as well as the underlying molecular mechanism in detail.
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Affiliation(s)
- Annika Buhr
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Ronja Schiemann
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Heiko Meyer
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany.,Center for Cellular Nanoanalytics (CellNanOs), Barbarastrasse 11, D-49076 Osnabruck, Germany
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3
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Klinke N, Meyer H, Ratnavadivel S, Reinhardt M, Heinisch JJ, Malmendal A, Milting H, Paululat A. A Drosophila melanogaster model for TMEM43-related arrhythmogenic right ventricular cardiomyopathy type 5. Cell Mol Life Sci 2022; 79:444. [PMID: 35869176 PMCID: PMC9307560 DOI: 10.1007/s00018-022-04458-0] [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: 04/08/2022] [Revised: 06/01/2022] [Accepted: 06/28/2022] [Indexed: 11/03/2022]
Abstract
AbstractArrhythmogenic right ventricular cardiomyopathy (ARVC) is a severe cardiac disease that leads to heart failure or sudden cardiac death (SCD). For the pathogenesis of ARVC, various mutations in at least eight different genes have been identified. A rare form of ARVC is associated with the mutation TMEM43 p.S358L, which is a fully penetrant variant in male carriers. TMEM43 p.S358 is homologous to CG8111 p.S333 in Drosophila melanogaster. We established CRISPR/Cas9-mediated CG8111 knock-out mutants in Drosophila, as well as transgenic fly lines carrying an overexpression construct of the CG8111 p.S333L substitution. Knock-out flies developed normally, whereas the overexpression of CG8111 p.S333L caused growth defects, loss of body weight, cardiac arrhythmias, and premature death. An evaluation of a series of model mutants that replaced S333 by selected amino acids proved that the conserved serine is critical for the physiological function of CG8111. Metabolomic and proteomic analyses revealed that the S333 in CG8111 is essential to proper energy homeostasis and lipid metabolism in the fly. Of note, metabolic impairments were also found in the murine Tmem43 disease model, and fibrofatty replacement is a hallmark of human ARVC5. These findings contribute to a more comprehensive understanding of the molecular functions of CG8111 in Drosophila, and can represent a valuable basis to assess the aetiology of the human TMEM43 p.S358L variant in more detail.
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Schiemann R, Buhr A, Cordes E, Walter S, Heinisch JJ, Ferrero P, Milting H, Paululat A, Meyer H. Neprilysins regulate muscle contraction and heart function via cleavage of SERCA-inhibitory micropeptides. Nat Commun 2022; 13:4420. [PMID: 35906206 PMCID: PMC9338278 DOI: 10.1038/s41467-022-31974-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/06/2022] [Indexed: 12/26/2022] Open
Abstract
Muscle contraction depends on strictly controlled Ca2+ transients within myocytes. A major player maintaining these transients is the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase, SERCA. Activity of SERCA is regulated by binding of micropeptides and impaired expression or function of these peptides results in cardiomyopathy. To date, it is not known how homeostasis or turnover of the micropeptides is regulated. Herein, we find that the Drosophila endopeptidase Neprilysin 4 hydrolyzes SERCA-inhibitory Sarcolamban peptides in membranes of the sarcoplasmic reticulum, thereby ensuring proper regulation of SERCA. Cleavage is necessary and sufficient to maintain homeostasis and function of the micropeptides. Analyses on human Neprilysin, sarcolipin, and ventricular cardiomyocytes indicates that the regulatory mechanism is evolutionarily conserved. By identifying a neprilysin as essential regulator of SERCA activity and Ca2+ homeostasis in cardiomyocytes, these data contribute to a more comprehensive understanding of the complex mechanisms that control muscle contraction and heart function in health and disease.
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Affiliation(s)
- Ronja Schiemann
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany
| | - Annika Buhr
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany
| | - Eva Cordes
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany
| | - Stefan Walter
- Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany
| | - Jürgen J Heinisch
- Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany.,Department of Genetics, Osnabrück University, 49076, Osnabrück, Germany
| | - Paola Ferrero
- Center for Cardiovascular Research - CONICET/National University of La Plata, 1900, La Plata, Argentina
| | - Hendrik Milting
- Heart & Diabetes Center NRW, University of Bochum, Erich & Hanna Klessmann-Institute for Cardiovascular Research and Development, 32545, Bad Oeynhausen, Germany
| | - Achim Paululat
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany.,Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany
| | - Heiko Meyer
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany. .,Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany.
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Santalla M, García A, Mattiazzi A, Valverde CA, Schiemann R, Paululat A, Hernández G, Meyer H, Ferrero P. Interplay between SERCA, 4E-BP, and eIF4E in the Drosophila heart. PLoS One 2022; 17:e0267156. [PMID: 35588119 PMCID: PMC9119464 DOI: 10.1371/journal.pone.0267156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 04/03/2022] [Indexed: 11/19/2022] Open
Abstract
Appropriate cardiac performance depends on a tightly controlled handling of Ca2+ in a broad range of species, from invertebrates to mammals. The role of the Ca2+ ATPase, SERCA, in Ca2+ handling is pivotal, and its activity is regulated, inter alia, by interacting with distinct proteins. Herein, we give evidence that 4E binding protein (4E-BP) is a novel regulator of SERCA activity in Drosophila melanogaster during cardiac function. Flies over-expressing 4E-BP showed improved cardiac performance in young individuals associated with incremented SERCA activity. Moreover, we demonstrate that SERCA interacts with translation initiation factors eIF4E-1, eIF4E-2 and eIF4E-4 in a yeast two-hybrid assay. The specific identification of eIF4E-4 in cardiac tissue leads us to propose that the interaction of elF4E-4 with SERCA may be the basis of the cardiac effects observed in 4E-BP over-expressing flies associated with incremented SERCA activity.
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Affiliation(s)
- Manuela Santalla
- Departamento de Ciencias Básicas y Experimentales, UNNOBA, Pergamino, Buenos Aires, Argentina
- Centro de Investigaciones Cardiovasculares ‘Dr. Horacio E. Cingolani’, CONICET-UNLP, La Plata, Buenos Aires, Argentina
| | - Alejandra García
- Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), Mexico City, Mexico
| | - Alicia Mattiazzi
- Centro de Investigaciones Cardiovasculares ‘Dr. Horacio E. Cingolani’, CONICET-UNLP, La Plata, Buenos Aires, Argentina
| | - Carlos A. Valverde
- Centro de Investigaciones Cardiovasculares ‘Dr. Horacio E. Cingolani’, CONICET-UNLP, La Plata, Buenos Aires, Argentina
| | - Ronja Schiemann
- Department of Zoology & Developmental Biology, Osnabrück University, Osnabrück, Germany
| | - Achim Paululat
- Department of Zoology & Developmental Biology, Osnabrück University, Osnabrück, Germany
| | - Greco Hernández
- Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), Mexico City, Mexico
| | - Heiko Meyer
- Department of Zoology & Developmental Biology, Osnabrück University, Osnabrück, Germany
- * E-mail: (PF); (HM)
| | - Paola Ferrero
- Departamento de Ciencias Básicas y Experimentales, UNNOBA, Pergamino, Buenos Aires, Argentina
- Centro de Investigaciones Cardiovasculares ‘Dr. Horacio E. Cingolani’, CONICET-UNLP, La Plata, Buenos Aires, Argentina
- * E-mail: (PF); (HM)
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Meyer H, Buhr A, Callaerts P, Schiemann R, Wolfner MF, Marygold SJ. Identification and bioinformatic analysis of neprilysin and neprilysin-like metalloendopeptidases in Drosophila melanogaster. MICROPUBLICATION BIOLOGY 2021; 2021:10.17912/micropub.biology.000410. [PMID: 34189422 PMCID: PMC8223033 DOI: 10.17912/micropub.biology.000410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The neprilysin (M13) family of metalloendopeptidases comprises highly conserved ectoenzymes that cleave and thereby inactivate many physiologically relevant peptides in the extracellular space. Impaired neprilysin activity is associated with numerous human diseases. Here, we present a comprehensive list and classification of M13 family members in Drosophila melanogaster. Seven Neprilysin (Nep) genes encode active peptidases, while 21 Neprilysin-like (Nepl) genes encode proteins predicted to be catalytically inactive. RNAseq data demonstrate that all 28 genes are expressed during development, often in a tissue-specific pattern. Most Nep proteins possess a transmembrane domain, whereas almost all Nepl proteins are predicted to be secreted.
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Affiliation(s)
- Heiko Meyer
- Department of Zoology & Developmental Biology, Osnabrück University, 49076 Osnabrück, Germany,
Correspondence to: Heiko Meyer (); Steven J. Marygold ()
| | - Annika Buhr
- Department of Zoology & Developmental Biology, Osnabrück University, 49076 Osnabrück, Germany
| | - Patrick Callaerts
- Laboratory of Behavioral and Developmental Genetics, Department of Human Genetics, KULeuven, University of Leuven, B-3000 Leuven, Belgium
| | - Ronja Schiemann
- Department of Zoology & Developmental Biology, Osnabrück University, 49076 Osnabrück, Germany
| | - Mariana F. Wolfner
- Department of Molecular Biology & Genetics, Cornell University, Ithaca NY 14853 USA
| | - Steven J. Marygold
- FlyBase, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, U.K.,
Correspondence to: Heiko Meyer (); Steven J. Marygold ()
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7
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Pathak H, Varghese J. Edem1 activity in the fat body regulates insulin signalling and metabolic homeostasis in Drosophila. Life Sci Alliance 2021; 4:4/8/e202101079. [PMID: 34140347 PMCID: PMC8321676 DOI: 10.26508/lsa.202101079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 11/24/2022] Open
Abstract
Edem1, an endoplasmic reticulum-resident protein, acts in the fat body to regulate insulin signalling and metabolic status in Drosophila, which aids in survival against nutrient deprivation. In Drosophila, nutrient status is sensed by the fat body, a functional homolog of mammalian liver and white adipocytes. The fat body conveys nutrient information to insulin-producing cells through humoral factors which regulate Drosophila insulin-like peptide levels and insulin signalling. Insulin signalling has pleiotropic functions, which include the management of growth and metabolic pathways. Here, we report that Edem1 (endoplasmic reticulum degradation–enhancing α-mannosidase–like protein 1), an endoplasmic reticulum–resident protein involved in protein quality control, acts in the fat body to regulate insulin signalling and thereby the metabolic status in Drosophila. Edem1 limits the fat body–derived Drosophila tumor necrosis factor-α Eiger activity on insulin-producing cells and maintains systemic insulin signalling in fed conditions. During food deprivation, edem1 gene expression levels drop, which aids in the reduction of systemic insulin signalling crucial for survival. Overall, we demonstrate that Edem1 plays a vital role in helping the organism to endure a fluctuating nutrient environment by managing insulin signalling and metabolic homeostasis.
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Affiliation(s)
- Himani Pathak
- School of Biology, Indian Institute of Science Education and Research (IISER TVM) Thiruvananthapuram, Kerala, India
| | - Jishy Varghese
- School of Biology, Indian Institute of Science Education and Research (IISER TVM) Thiruvananthapuram, Kerala, India
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8
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Mitra R, Richhariya S, Jayakumar S, Notani D, Hasan G. IP3-mediated Ca2+ signals regulate larval to pupal transition under nutrient stress through the H3K36 methyltransferase Set2. Development 2021; 148:269014. [PMID: 34117888 DOI: 10.1242/dev.199018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 05/04/2021] [Indexed: 12/13/2022]
Abstract
Persistent loss of dietary protein usually signals a shutdown of key metabolic pathways. In Drosophila larvae that have reached a 'critical weight' and can pupariate to form viable adults, such a metabolic shutdown would needlessly lead to death. Inositol 1,4,5-trisphosphate-mediated calcium (IP3/Ca2+) release in some interneurons (vGlutVGN6341) allows Drosophila larvae to pupariate on a protein-deficient diet by partially circumventing this shutdown through upregulation of neuropeptide signaling and the expression of ecdysone synthesis genes. Here, we show that IP3/Ca2+ signals in vGlutVGN6341 neurons drive expression of Set2, a gene encoding Drosophila Histone 3 Lysine 36 methyltransferase. Furthermore, Set2 expression is required for larvae to pupariate in the absence of dietary protein. IP3/Ca2+ signal-driven Set2 expression upregulates key Ca2+-signaling genes through a novel positive-feedback loop. Transcriptomic studies, coupled with analysis of existing ChIP-seq datasets, identified genes from larval and pupal stages that normally exhibit robust H3K36 trimethyl marks on their gene bodies and concomitantly undergo stronger downregulation by knockdown of either the intracellular Ca2+ release channel IP3R or Set2. IP3/Ca2+ signals thus regulate gene expression through Set2-mediated H3K36 marks on select neuronal genes for the larval to pupal transition.
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Affiliation(s)
- Rishav Mitra
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Shlesha Richhariya
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Siddharth Jayakumar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Dimple Notani
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
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Opachaloemphan C, Mancini G, Konstantinides N, Parikh A, Mlejnek J, Yan H, Reinberg D, Desplan C. Early behavioral and molecular events leading to caste switching in the ant Harpegnathos. Genes Dev 2021; 35:410-424. [PMID: 33602869 PMCID: PMC7919410 DOI: 10.1101/gad.343699.120] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/15/2021] [Indexed: 12/14/2022]
Abstract
Ant societies show a division of labor in which a queen is in charge of reproduction while nonreproductive workers maintain the colony. In Harpegnathos saltator, workers retain reproductive ability, inhibited by the queen pheromones. Following the queen loss, the colony undergoes social unrest with an antennal dueling tournament. Most workers quickly abandon the tournament while a few workers continue the dueling for months and become gamergates (pseudoqueens). However, the temporal dynamics of the social behavior and molecular mechanisms underlining the caste transition and social dominance remain unclear. By tracking behaviors, we show that the gamergate fate is accurately determined 3 d after initiation of the tournament. To identify genetic factors responsible for this commitment, we compared transcriptomes of different tissues between dueling and nondueling workers. We found that juvenile hormone is globally repressed, whereas ecdysone biosynthesis in the ovary is increased in gamergates. We show that molecular changes in the brain serve as earliest caste predictors compared with other tissues. Thus, behavioral and molecular data indicate that despite the prolonged social upheaval, the gamergate fate is rapidly established, suggesting a robust re-establishment of social structure.
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Affiliation(s)
- Comzit Opachaloemphan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
| | - Giacomo Mancini
- Department of Biology, New York University, New York, New York 10003, USA
| | | | - Apurva Parikh
- Department of Biology, New York University, New York, New York 10003, USA
| | - Jakub Mlejnek
- Department of Biology, New York University, New York, New York 10003, USA
| | - Hua Yan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, New York 10016, USA
| | - Danny Reinberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, New York 10016, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, New York 10003, USA
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Bretscher H, O’Connor MB. The Role of Muscle in Insect Energy Homeostasis. Front Physiol 2020; 11:580687. [PMID: 33192587 PMCID: PMC7649811 DOI: 10.3389/fphys.2020.580687] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/09/2020] [Indexed: 12/16/2022] Open
Abstract
Maintaining energy homeostasis is critical for ensuring proper growth and maximizing survival potential of all organisms. Here we review the role of somatic muscle in regulating energy homeostasis in insects. The muscle is not only a large consumer of energy, it also plays a crucial role in regulating metabolic signaling pathways and energy stores of the organism. We examine the metabolic pathways required to supply the muscle with energy, as well as muscle-derived signals that regulate metabolic energy homeostasis.
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Affiliation(s)
| | - Michael B. O’Connor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, United States
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11
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Drosophila Middle-Term Memory: Amnesiac is Required for PKA Activation in the Mushroom Bodies, a Function Modulated by Neprilysin 1. J Neurosci 2020; 40:4219-4229. [PMID: 32303647 DOI: 10.1523/jneurosci.2311-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 03/30/2020] [Accepted: 04/05/2020] [Indexed: 11/21/2022] Open
Abstract
In Drosophila, the mushroom bodies (MB) constitute the central brain structure for olfactory associative memory. As in mammals, the cAMP/PKA pathway plays a key role in memory formation. In the MB, Rutabaga (Rut) adenylate cyclase acts as a coincidence detector during associative conditioning to integrate calcium influx resulting from acetylcholine stimulation and G-protein activation resulting from dopaminergic stimulation. Amnesiac encodes a secreted neuropeptide required in the MB for two phases of aversive olfactory memory. Previous sequence analysis has revealed strong homology with the mammalian pituitary adenylate cyclase-activating peptide (PACAP). Here, we examined whether amnesiac is involved in cAMP/PKA dynamics in response to dopamine and acetylcholine co-stimulation in living flies. Experiments were conducted with both sexes, or with either sex. Our data show that amnesiac is necessary for the PKA activation process that results from coincidence detection in the MB. Since PACAP peptide is cleaved by the human membrane neprilysin hNEP, we searched for an interaction between Amnesiac and Neprilysin 1 (Nep1), a fly neprilysin involved in memory. We show that when Nep1 expression is acutely knocked down in adult MB, memory deficits displayed by amn hypomorphic mutants are rescued. Consistently, Nep1 inhibition also restores normal PKA activation in amn mutant flies. Taken together, the results suggest that Nep1 targets Amnesiac degradation to terminate its signaling function. Our work thus highlights a key role for Amnesiac in establishing within the MB the PKA dynamics that sustain middle-term memory (MTM) formation, a function modulated by Nep1.SIGNIFICANCE STATEMENT The Drosophila amnesiac gene encodes a secreted neuropeptide whose expression is required for specific memory phases in the mushroom bodies (MB), the olfactory memory center. Here, we show that Amnesiac is required for PKA activation resulting from coincidence detection, a mechanism by which the MB integrate two spatially distinct stimuli to encode associative memory. Furthermore, our results uncover a functional relationship between Amnesiac and Neprilysin 1 (Nep1), a membrane peptidase involved in memory and expressed in the MB. These results suggest that Nep1 modulates Amnesiac levels. We propose that on conditioning, Amnesiac release from the MB allows, via an autocrine process, the sustaining of PKA activation-mediating memory, which subsequently is inactivated by Nep1 degradation.
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12
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Sudhakar SR, Pathak H, Rehman N, Fernandes J, Vishnu S, Varghese J. Insulin signalling elicits hunger-induced feeding in Drosophila. Dev Biol 2020; 459:87-99. [DOI: 10.1016/j.ydbio.2019.11.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 11/18/2019] [Accepted: 11/20/2019] [Indexed: 12/21/2022]
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13
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Gómez IM, Rodríguez MA, Santalla M, Kassis G, Colman Lerner JE, Aranda JO, Sedán D, Andrinolo D, Valverde CA, Ferrero P. Inhalation of marijuana affects Drosophila heart function. Biol Open 2019; 8:bio.044081. [PMID: 31324618 PMCID: PMC6737967 DOI: 10.1242/bio.044081] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We investigated the effect of inhalation of vaporized marijuana on cardiac function in Drosophila melanogaster, a suitable genetic model for studying human diseases. Adult flies were exposed to marijuana for variable time periods and the effects on cardiac function were studied. Short treatment protocol incremented heart-rate variability. Contractility was augmented only under prolonged exposure to cannabis and it was associated with incremented calcium transient within cardiomyocytes. Neither the activity of the major proteins responsible for calcium handling nor the calcium load of the sarcoplasmic reticulum were affected by the cannabis treatment. The observed changes manifested in the cardiomyocytes even in the absence of the canonical cannabinoid receptors described in mammals. Our results are the first evidence of the in vivo impact of phytocannabinoids in D. melanogaster. By providing a simple and affordable platform prior to mammalian models, this characterization of cardiac function under marijuana exposure opens new paths for conducting genetic screenings using vaporized compounds.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Ivana M Gómez
- Centro de Investigaciones Cardiovasculares 'Dr. Horacio E. Cingolani', Facultad de Ciencias Médicas, UNLP, La Plata 1900, Argentina
| | - Maia A Rodríguez
- Centro de Investigaciones Cardiovasculares 'Dr. Horacio E. Cingolani', Facultad de Ciencias Médicas, UNLP, La Plata 1900, Argentina
| | - Manuela Santalla
- Centro de Investigaciones Cardiovasculares 'Dr. Horacio E. Cingolani', Facultad de Ciencias Médicas, UNLP, La Plata 1900, Argentina.,Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Pergamino 2700, Argentina
| | | | - Jorge E Colman Lerner
- Centro de Investigación y Desarrollo en Ciencias Aplicadas Facultad de Ciencias Exactas, CCT La Plata-UNLP-CICPBA, La Plata 1900, Argentina
| | - J Oswaldo Aranda
- Programa Ambiental de Extensión Universitaria. Facultad de Ciencias Exactas-UNLP, La Plata 1900, Argentina
| | - Daniela Sedán
- Centro de Investigaciones del medio Ambiente Facultad de Ciencias Exactas, CCT La Plata-UNLP, La Plata 1900, Argentina
| | - Dario Andrinolo
- Centro de Investigaciones del medio Ambiente Facultad de Ciencias Exactas, CCT La Plata-UNLP, La Plata 1900, Argentina
| | - Carlos A Valverde
- Centro de Investigaciones Cardiovasculares 'Dr. Horacio E. Cingolani', Facultad de Ciencias Médicas, UNLP, La Plata 1900, Argentina
| | - Paola Ferrero
- Centro de Investigaciones Cardiovasculares 'Dr. Horacio E. Cingolani', Facultad de Ciencias Médicas, UNLP, La Plata 1900, Argentina .,Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Pergamino 2700, Argentina
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14
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Ramirez AK, Dankel S, Cai W, Sakaguchi M, Kasif S, Kahn CR. Membrane metallo-endopeptidase (Neprilysin) regulates inflammatory response and insulin signaling in white preadipocytes. Mol Metab 2019; 22:21-36. [PMID: 30795914 PMCID: PMC6437599 DOI: 10.1016/j.molmet.2019.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 01/04/2019] [Accepted: 01/17/2019] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Accumulation of visceral white adipose tissue (WAT) associates with insulin resistance, adipose tissue inflammation, and metabolic syndrome, whereas accumulation of subcutaneous WAT may be protective. We aimed to identify molecular mechanisms that might provide mechanistic insights underlying the phenotypic differences in these tissues. Membrane Metallo-Endopeptidase (MME/Neprislyin) is an extracellular, membrane-bound protease enriched in subcutaneous WAT that can target degradation of a variety of peptides, including insulin, IL6, and β-amyloids. We hypothesized that MME contributes to adipose depot-specific metabolic properties. METHODS We performed RNA sequencing on human subcutaneous and visceral preadipocytes and array gene expression profiling in murine subcutaneous and visceral preadipocytes. We conducted several insulin signaling and inflammatory response experiments on different cellular states of MME expression. RESULTS MME in white preadipocytes is expressed at a higher level in subcutaneous compared to visceral WAT and favors insulin signaling and a low inflammatory response. Thus, knockdown of MME in subcutaneous preadipocytes increased the inflammatory response to substance P and amyloid β aggregates. This associated with increased basal insulin signaling and decreased insulin-stimulated signaling. Moreover, MME differentially regulates the internalization and turnover of the α/β subunits of the insulin receptor. CONCLUSION MME is a novel regulator of the insulin receptor in adipose tissue. Given the clinical significance of both chronic inflammation and insulin sensitivity in metabolic disease, these results show a potentially new target to increase insulin sensitivity and decrease inflammatory susceptibility.
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Affiliation(s)
- Alfred K Ramirez
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA; Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Simon Dankel
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA; Hormone Laboratory, Haukeland University Hospital, 5020 Bergen, Norway
| | - Weikang Cai
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Masaji Sakaguchi
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Simon Kasif
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Graduate Program in Bioinformatics, Boston University, Boston, MA 02215, USA
| | - C Ronald Kahn
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA.
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15
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Nässel DR, Zandawala M. Recent advances in neuropeptide signaling in Drosophila, from genes to physiology and behavior. Prog Neurobiol 2019; 179:101607. [PMID: 30905728 DOI: 10.1016/j.pneurobio.2019.02.003] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/18/2019] [Accepted: 02/28/2019] [Indexed: 12/11/2022]
Abstract
This review focuses on neuropeptides and peptide hormones, the largest and most diverse class of neuroactive substances, known in Drosophila and other animals to play roles in almost all aspects of daily life, as w;1;ell as in developmental processes. We provide an update on novel neuropeptides and receptors identified in the last decade, and highlight progress in analysis of neuropeptide signaling in Drosophila. Especially exciting is the huge amount of work published on novel functions of neuropeptides and peptide hormones in Drosophila, largely due to the rapid developments of powerful genetic methods, imaging techniques and innovative assays. We critically discuss the roles of peptides in olfaction, taste, foraging, feeding, clock function/sleep, aggression, mating/reproduction, learning and other behaviors, as well as in regulation of development, growth, metabolic and water homeostasis, stress responses, fecundity, and lifespan. We furthermore provide novel information on neuropeptide distribution and organization of peptidergic systems, as well as the phylogenetic relations between Drosophila neuropeptides and those of other phyla, including mammals. As will be shown, neuropeptide signaling is phylogenetically ancient, and not only are the structures of the peptides, precursors and receptors conserved over evolution, but also many functions of neuropeptide signaling in physiology and behavior.
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Affiliation(s)
- Dick R Nässel
- Department of Zoology, Stockholm University, Stockholm, Sweden.
| | - Meet Zandawala
- Department of Zoology, Stockholm University, Stockholm, Sweden; Department of Neuroscience, Brown University, Providence, RI, USA.
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16
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Schiemann R, Lammers K, Janz M, Lohmann J, Paululat A, Meyer H. Identification and In Vivo Characterisation of Cardioactive Peptides in Drosophila melanogaster. Int J Mol Sci 2018; 20:ijms20010002. [PMID: 30577424 PMCID: PMC6337577 DOI: 10.3390/ijms20010002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 11/22/2018] [Indexed: 12/23/2022] Open
Abstract
Neuropeptides and peptide hormones serve as critical regulators of numerous biological processes, including development, growth, reproduction, physiology, and behaviour. In mammals, peptidergic regulatory systems are complex and often involve multiple peptides that act at different levels and relay to different receptors. To improve the mechanistic understanding of such complex systems, invertebrate models in which evolutionarily conserved peptides and receptors regulate similar biological processes but in a less complex manner have emerged as highly valuable. Drosophila melanogaster represents a favoured model for the characterisation of novel peptidergic signalling events and for evaluating the relevance of those events in vivo. In the present study, we analysed a set of neuropeptides and peptide hormones for their ability to modulate cardiac function in semi-intact larval Drosophila melanogaster. We identified numerous peptides that significantly affected heart parameters such as heart rate, systolic and diastolic interval, rhythmicity, and contractility. Thus, peptidergic regulation of the Drosophila heart is not restricted to chronotropic adaptation but also includes inotropic modulation. By specifically interfering with the expression of corresponding peptides in transgenic animals, we assessed the in vivo relevance of the respective peptidergic regulation. Based on the functional conservation of certain peptides throughout the animal kingdom, the identified cardiomodulatory activities may be relevant not only to proper heart function in Drosophila, but also to corresponding processes in vertebrates, including humans.
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Affiliation(s)
- Ronja Schiemann
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Kay Lammers
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Maren Janz
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Jana Lohmann
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Achim Paululat
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Heiko Meyer
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
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17
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Wilmes AC, Klinke N, Rotstein B, Meyer H, Paululat A. Biosynthesis and assembly of the Collagen IV-like protein Pericardin in Drosophila melanogaster. Biol Open 2018; 7:7/4/bio030361. [PMID: 29685999 PMCID: PMC5936059 DOI: 10.1242/bio.030361] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In Drosophila, formation of the cardiac extracellular matrix (ECM) starts during embryogenesis. Assembly and incorporation of structural proteins such as Collagen IV, Pericardin, and Laminin A, B1, and B2 into the cardiac ECM is critical to the maintenance of heart integrity and functionality and, therefore, to longevity of the animal. The cardiac ECM connects the heart tube with the alary muscles; thus, the ECM contributes to a flexible positioning of the heart within the animal's body. Moreover, the cardiac ECM holds the larval pericardial nephrocytes in close proximity to the heart tube and the inflow tract, which is assumed to be critical to efficient haemolymph clearance. Mutations in either structural ECM constituents or ECM receptors cause breakdown of the ECM network upon ageing, with disconnection of the heart tube from alary muscles becoming apparent at larval stages. Finally, the heart becomes non-functional. Here, we characterised existing and new pericardin mutants and investigated biosynthesis, secretion, and assembly of Pericardin in matrices. We identified two new pericardin alleles, which turned out to be a null (pericardin3-548) and a hypomorphic allele (pericardin3-21). Both mutants could be rescued with a genomic duplication of a fosmid coding for the pericardin locus. Biochemical analysis revealed that Pericardin is highly glycosylated and forms redox-dependent multimers. Multimer formation is remarkably reduced in animals deficient for the prolyl-4 hydroxylase cluster at 75D3-4. Summary: We identified two new pericardin alleles. Both mutants could be rescued with a genomic duplication of a fosmid coding for the pericardin locus. Biochemical analysis revealed that Pericardin is highly glycosylated and forms redox-dependent multimers.
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Affiliation(s)
- Ariane C Wilmes
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Nora Klinke
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Barbara Rotstein
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Heiko Meyer
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Achim Paululat
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
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18
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Rotstein B, Post Y, Reinhardt M, Lammers K, Buhr A, Heinisch JJ, Meyer H, Paululat A. Distinct domains in the matricellular protein Lonely heart are crucial for cardiac extracellular matrix formation and heart function in Drosophila. J Biol Chem 2018; 293:7864-7879. [PMID: 29599288 DOI: 10.1074/jbc.m117.817940] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 03/29/2018] [Indexed: 12/22/2022] Open
Abstract
The biomechanical properties of extracellular matrices (ECMs) are critical to many biological processes, including cell-cell communication and cell migration and function. The correct balance between stiffness and elasticity is essential to the function of numerous tissues, including blood vessels and the lymphatic system, and depends on ECM constituents (the "matrisome") and on their level of interconnection. However, despite its physiological relevance, the matrisome composition and organization remain poorly understood. Previously, we reported that the ADAMTS-like protein Lonely heart (Loh) is critical for recruiting the type IV collagen-like protein Pericardin to the cardiac ECM. Here, we utilized Drosophila as a simple and genetically amenable invertebrate model for studying Loh-mediated recruitment of tissue-specific ECM components such as Pericardin to the ECM. We focused on the functional relevance of distinct Loh domains to protein localization and Pericardin recruitment. Analysis of Loh deletion constructs revealed that one thrombospondin type 1 repeat (TSR1-1), which has an embedded WXXW motif, is critical for anchoring Loh to the ECM. Two other thrombospondin repeats, TSR1-2 and TSR1-4, the latter containing a CXXTCXXG motif, appeared to be dispensable for tethering Loh to the ECM but were crucial for proper interaction with and recruitment of Pericardin. Moreover, our results also suggested that Pericardin in the cardiac ECM primarily ensures the structural integrity of the heart, rather than increasing tissue flexibility. In conclusion, our work provides new insights into the roles of thrombospondin type 1 repeats and advances our understanding of cardiac ECM assembly and function.
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Affiliation(s)
| | - Yanina Post
- From the Departments of Zoology and Developmental Biology and
| | | | - Kay Lammers
- From the Departments of Zoology and Developmental Biology and
| | - Annika Buhr
- From the Departments of Zoology and Developmental Biology and
| | - Jürgen J Heinisch
- Genetics, Faculty of Biology & Chemistry, University of Osnabrück Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Heiko Meyer
- From the Departments of Zoology and Developmental Biology and
| | - Achim Paululat
- From the Departments of Zoology and Developmental Biology and
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19
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Yang H, Hultmark D. Drosophila muscles regulate the immune response against wasp infection via carbohydrate metabolism. Sci Rep 2017; 7:15713. [PMID: 29146985 PMCID: PMC5691183 DOI: 10.1038/s41598-017-15940-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 11/06/2017] [Indexed: 11/09/2022] Open
Abstract
We recently found that JAK/STAT signaling in skeletal muscles is important for the immune response of Drosophila larvae against wasp infection, but it was not clear how muscles could affect the immune response. Here we show that insulin signaling is required in muscles, but not in fat body or hemocytes, during larval development for an efficient encapsulation response and for the formation of lamellocytes. This effect requires TOR signaling. We show that muscle tissue affects the immune response by acting as a master regulator of carbohydrate metabolism in the infected animal, via JAK/STAT and insulin signaling in the muscles, and that there is indirect positive feedback between JAK/STAT and insulin signaling in the muscles. Specifically, stimulation of JAK/STAT signaling in the muscles can rescue the deficient immune response when insulin signaling is suppressed. Our results shed new light on the interaction between metabolism, immunity, and tissue communication.
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Affiliation(s)
- Hairu Yang
- Department of Molecular Biology, Umeå University, S-901 87, Umeå, Sweden.,Immunology Program, Memorial Sloan Kettering Cancer Center (MSKCC), New York, NY, 10065, USA
| | - Dan Hultmark
- Department of Molecular Biology, Umeå University, S-901 87, Umeå, Sweden. .,Institute of Biomedical Technology, University of Tampere, FI-33520, Tampere, Finland.
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20
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Drosophila Neprilysin 1 Rescues Memory Deficits Caused by Amyloid-β Peptide. J Neurosci 2017; 37:10334-10345. [PMID: 28931572 DOI: 10.1523/jneurosci.1634-17.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/07/2017] [Accepted: 09/15/2017] [Indexed: 02/02/2023] Open
Abstract
Neprilysins are Type II metalloproteinases known to degrade and inactivate a number of small peptides, in particular the mammalian amyloid-β peptide (Aβ). In Drosophila, several neprilysins expressed in the brain are required for middle-term (MTM) and long-term memory (LTM) in the dorsal paired medial (DPM) neurons, a pair of large neurons that broadly innervate the mushroom bodies (MB), the center of olfactory memory. These data indicate that one or several peptides need to be degraded for MTM and LTM. We have previously shown that the fly amyloid precursor protein (APPL) is required for memory in the MB. We show here that APPL is also required in adult DPM neurons for MTM and LTM formation. This finding prompted us to search for an interaction between neprilysins and Drosophila Aβ (dAβ), a cleavage product of APPL. To find out whether dAβ was a neprilysin's target, we used inducible drivers to modulate neprilysin 1 (Nep1) and dAβ expression in adult DPM neurons. Experiments were conducted either in both sexes or in females. We show that Nep1 inhibition makes dAβ expression detrimental to both MTM and LTM. Conversely, memory deficits displayed by dAβ-expressing flies are rescued by Nep1 overexpression. Consistent with behavioral data, biochemical analyses confirmed that Nep1 degrades dAβ. Together, our findings establish that Nep1 and dAβ expressed in DPM neurons are functionally linked for memory processes, suggesting that dAβ is a physiological target for Nep1.SIGNIFICANCE STATEMENT Neprilysins are endopeptidases known to degrade a number of small peptides and in particular the amyloid peptide. We previously showed that all four neprilysins expressed in the Drosophila brain are involved in specific phases of olfactory memory. Here we show that an increase in the level of the neprilysin 1 peptidase overcomes memory deficits induced by amyloid peptide in young flies. Together, the data reveal a functional interaction between neprilysin 1 and amyloid peptide, suggesting that neprilysin 1 degrades amyloid peptide. These findings raise the possibility that, under nonpathological conditions, mammalian neprilysins degrade amyloid peptide to ensure memory formation.
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