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Wang W, Chen JS, He PY, Zhang MH, Cao HQ, Palli SR, Sheng CW. Identification and pharmacological characterization of pH-sensitive chloride channels in the fall armyworm, Spodoptera frugiperda. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 177:104243. [PMID: 39645056 DOI: 10.1016/j.ibmb.2024.104243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2024] [Revised: 11/11/2024] [Accepted: 12/04/2024] [Indexed: 12/09/2024]
Abstract
The pH-sensitive chloride channels (pHCls) are unique to invertebrates and play crucial roles in fluid regulation, food selection, and intake. In this study, we identified and isolated two cDNAs encoding the SfpHCl1 and SfpHCl2 subunits from the fall armyworm, Spodoptera frugiperda. Both subunits exhibited similar expression patterns. When expressed in Xenopus laevis oocytes, SfpHCl1 and SfpHCl2 formed functional chloride channels with reversal potentials indicative of chloride selectivity. Shifts in extracellular pH from acidic to alkaline conditions induced inward currents in both SfpHCl1 and SfpHCl2, with EC50 values of pH 8.24 and 8.49, respectively. Zinc ions (Zn2⁺) and the insecticide emamectin benzoate (EB) also activated concentration-dependent inward currents in these channels, whether expressed individually or co-expressed. Notably, SfpHCl1 and SfpHCl2 channels exhibited significant differences in their activation and deactivation time constants. These findings elucidate the biophysical and pharmacological characteristics of pH-sensitive, zinc-gated chloride channels, which, being exclusive to invertebrates, present a promising target for the development of highly specific insecticides.
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Affiliation(s)
- Wei Wang
- The Key Laboratory of Agri-products Quality and Biosafety, Ministry of Education, Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China
| | - Jia-Sheng Chen
- The Key Laboratory of Agri-products Quality and Biosafety, Ministry of Education, Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China; Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
| | - Pei-Yun He
- The Key Laboratory of Agri-products Quality and Biosafety, Ministry of Education, Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China
| | - Mo-Han Zhang
- The Key Laboratory of Agri-products Quality and Biosafety, Ministry of Education, Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China
| | - Hai-Qun Cao
- The Key Laboratory of Agri-products Quality and Biosafety, Ministry of Education, Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China; Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China
| | - Subba Reddy Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
| | - Cheng-Wang Sheng
- The Key Laboratory of Agri-products Quality and Biosafety, Ministry of Education, Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China; Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, PR China.
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2
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Agard MA, Zandawala M, Paluzzi JPV. Another fly diuretic hormone: tachykinins increase fluid and ion transport by adult Drosophila melanogaster Malpighian 'renal' tubules. J Exp Biol 2024; 227:jeb247668. [PMID: 39319454 DOI: 10.1242/jeb.247668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 09/05/2024] [Indexed: 09/26/2024]
Abstract
Insects such as the model organism Drosophila melanogaster must modulate their internal physiology to withstand changes in temperature and availability of water and food. Regulation of the excretory system by peptidergic hormones is one mechanism by which insects maintain their internal homeostasis. Tachykinins are a family of neuropeptides that have been shown to stimulate fluid secretion from the Malpighian 'renal' tubules (MTs) in some insect species, but it is unclear if that is the case in the fruit fly, D. melanogaster. A central objective of the current study was to examine the physiological role of tachykinin signaling in the MTs of adult D. melanogaster. Using the genetic toolbox available in this model organism along with in vitro and whole-animal bioassays, our results indicate that Drosophila tachykinins (DTKs) function as diuretic hormones by binding to the DTK receptor (DTKR) localized in stellate cells of the MTs. Specifically, DTK activates cation and anion transport across the stimulated MTs, which impairs their survival in response to desiccation because of their inability to conserve water. Thus, besides their previously described roles in neuromodulation of pathways controlling locomotion and food search, olfactory processing, aggression, lipid metabolism and metabolic stress, processing of noxious stimuli and hormone release, DTKs also appear to function as bona fide endocrine factors regulating the excretory system and appear essential for the maintenance of hydromineral balance.
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Affiliation(s)
- Marishia A Agard
- Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Meet Zandawala
- Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno 89557, NV, USA
| | - Jean-Paul V Paluzzi
- Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
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3
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Dates J, Kolosov D. Voltage-gated ion channels as novel regulators of epithelial ion transport in the osmoregulatory organs of insects. FRONTIERS IN INSECT SCIENCE 2024; 4:1385895. [PMID: 38835480 PMCID: PMC11148248 DOI: 10.3389/finsc.2024.1385895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 05/01/2024] [Indexed: 06/06/2024]
Abstract
Voltage-gated ion channels (VGICs) respond to changes in membrane potential (Vm) and typically exhibit fast kinetic properties. They play an important role in signal detection and propagation in excitable tissues. In contrast, the role of VGICs in non-excitable tissues like epithelia is less studied and less clear. Studies in epithelia of vertebrates and invertebrates demonstrate wide expression of VGICs in epithelia of animals. Recently, VGICs have emerged as regulators of ion transport in the Malpighian tubules (MTs) and other osmoregulatory organs of insects. This mini-review aims to concisely summarize which VGICs have been implicated in the regulation of ion transport in the osmoregulatory epithelia of insects to date, and highlight select groups for further study. We have also speculated on the roles VGICs may potentially play in regulating processes connected directly to ion transport in insects (e.g., acid-base balance, desiccation, thermal tolerance). This review is not meant to be exhaustive but should rather serve as a thought-provoking collection of select existing highlights on VGICs, and to emphasize how understudied this mechanism of ion transport regulation is in insect epithelia.
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Affiliation(s)
- Jocelyne Dates
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, United States
| | - Dennis Kolosov
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, United States
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4
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Xu J, Liu Y, Yang F, Cao Y, Chen W, Li JSS, Zhang S, Comjean A, Hu Y, Perrimon N. Mechanistic characterization of a Drosophila model of paraneoplastic nephrotic syndrome. Nat Commun 2024; 15:1241. [PMID: 38336808 PMCID: PMC10858251 DOI: 10.1038/s41467-024-45493-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
Paraneoplastic syndromes occur in cancer patients and originate from dysfunction of organs at a distance from the tumor or its metastasis. A wide range of organs can be affected in paraneoplastic syndromes; however, the pathological mechanisms by which tumors influence host organs are poorly understood. Recent studies in the fly uncovered that tumor secreted factors target host organs, leading to pathological effects. In this study, using a Drosophila gut tumor model, we characterize a mechanism of tumor-induced kidney dysfunction. Specifically, we find that Pvf1, a PDGF/VEGF signaling ligand, secreted by gut tumors activates the PvR/JNK/Jra signaling pathway in the principal cells of the kidney, leading to mis-expression of renal genes and paraneoplastic renal syndrome-like phenotypes. Our study describes an important mechanism by which gut tumors perturb the function of the kidney, which might be of clinical relevance for the treatment of paraneoplastic syndromes.
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Affiliation(s)
- Jun Xu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| | - Ying Liu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| | - Fangying Yang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yurou Cao
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Weihang Chen
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Joshua Shing Shun Li
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Shuai Zhang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Aram Comjean
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Yanhui Hu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Boston, MA, USA.
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5
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Halberg KV, Denholm B. Mechanisms of Systemic Osmoregulation in Insects. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:415-438. [PMID: 37758224 DOI: 10.1146/annurev-ento-040323-021222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Water is essential to life. Terrestrial insects lose water by evaporation from the body surface and respiratory surfaces, as well as in the excretory products, posing a challenge made more acute by their high surface-to-volume ratio. These losses must be kept to a minimum and be offset by water gained from other sources. By contrast, insects such as the blood-sucking bug Rhodnius prolixus consume up to 10 times their body weight in a single blood meal, necessitating rapid expulsion of excess water and ions. How do insects manage their ion and water budgets? A century of study has revealed a great deal about the organ systems that insects use to maintain their ion and water balance and their regulation. Traditionally, a taxonomically wide range of species were studied, whereas more recent research has focused on model organisms to leverage the power of the molecular genetic approach. Key advances in new technologies have become available for a wider range of species in the past decade. We document how these approaches have already begun to inform our understanding of the diversity and conservation of insect systemic osmoregulation. We advocate that these technologies be combined with traditional approaches to study a broader range of nonmodel species to gain a comprehensive overview of the mechanism underpinning systemic osmoregulation in the most species-rich group of animals on earth, the insects.
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Affiliation(s)
- Kenneth Veland Halberg
- Section for Cell and Neurobiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark;
| | - Barry Denholm
- Department of Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
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6
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Dornan AJ, Halberg KV, Beuter LK, Davies SA, Dow JAT. Compromised junctional integrity phenocopies age-dependent renal dysfunction in Drosophila Snakeskin mutants. J Cell Sci 2023; 136:jcs261118. [PMID: 37694602 PMCID: PMC10565245 DOI: 10.1242/jcs.261118] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
Transporting epithelia provide a protective barrier against pathogenic insults while allowing the controlled exchange of ions, solutes and water with the external environment. In invertebrates, these functions depend on formation and maintenance of 'tight' septate junctions (SJs). However, the mechanism by which SJs affect transport competence and tissue homeostasis, and how these are modulated by ageing, remain incompletely understood. Here, we demonstrate that the Drosophila renal (Malpighian) tubules undergo an age-dependent decline in secretory capacity, which correlates with mislocalisation of SJ proteins and progressive degeneration in cellular morphology and tissue homeostasis. Acute loss of the SJ protein Snakeskin in adult tubules induced progressive changes in cellular and tissue architecture, including altered expression and localisation of junctional proteins with concomitant loss of cell polarity and barrier integrity, demonstrating that compromised junctional integrity is sufficient to replicate these ageing-related phenotypes. Taken together, our work demonstrates a crucial link between epithelial barrier integrity, tubule transport competence, renal homeostasis and organismal viability, as well as providing novel insights into the mechanisms underpinning ageing and renal disease.
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Affiliation(s)
- Anthony J. Dornan
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Kenneth V. Halberg
- Section for Cell and Neurobiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen DK-2100, Denmark
| | - Liesa-Kristin Beuter
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
- Department of Animal Ecology and Systematics, Justus-Liebig-University Giessen, Giessen D-35392, Germany
| | - Shireen-Anne Davies
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Julian A. T. Dow
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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7
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Koyama T, Rana DW, Halberg KV. Managing fuels and fluids: Network integration of osmoregulatory and metabolic hormonal circuits in the polymodal control of homeostasis in insects. Bioessays 2023; 45:e2300011. [PMID: 37327252 DOI: 10.1002/bies.202300011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 05/19/2023] [Accepted: 05/30/2023] [Indexed: 06/18/2023]
Abstract
Osmoregulation in insects is an essential process whereby changes in hemolymph osmotic pressure induce the release of diuretic or antidiuretic hormones to recruit individual osmoregulatory responses in a manner that optimizes overall homeostasis. However, the mechanisms by which different osmoregulatory circuits interact with other homeostatic networks to implement the correct homeostatic program remain largely unexplored. Surprisingly, recent advances in insect genetics have revealed several important metabolic functions are regulated by classic osmoregulatory pathways, suggesting that internal cues related to osmotic and metabolic perturbations are integrated by the same hormonal networks. Here, we review our current knowledge on the network mechanisms that underpin systemic osmoregulation and discuss the remarkable parallels between the hormonal networks that regulate body fluid balance and those involved in energy homeostasis to provide a framework for understanding the polymodal optimization of homeostasis in insects.
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Affiliation(s)
- Takashi Koyama
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Danial Wasim Rana
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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8
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Xu J, Liu Y, Li H, Tarashansky AJ, Kalicki CH, Hung RJ, Hu Y, Comjean A, Kolluru SS, Wang B, Quake SR, Luo L, McMahon AP, Dow JAT, Perrimon N. Transcriptional and functional motifs defining renal function revealed by single-nucleus RNA sequencing. Proc Natl Acad Sci U S A 2022; 119:e2203179119. [PMID: 35696569 PMCID: PMC9231607 DOI: 10.1073/pnas.2203179119] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/11/2022] [Indexed: 01/09/2023] Open
Abstract
Recent advances in single-cell sequencing provide a unique opportunity to gain novel insights into the diversity, lineage, and functions of cell types constituting a tissue/organ. Here, we performed a single-nucleus study of the adult Drosophila renal system, consisting of Malpighian tubules and nephrocytes, which shares similarities with the mammalian kidney. We identified 11 distinct clusters representing renal stem cells, stellate cells, regionally specific principal cells, garland nephrocyte cells, and pericardial nephrocytes. Characterization of the transcription factors specific to each cluster identified fruitless (fru) as playing a role in stem cell regeneration and Hepatocyte nuclear factor 4 (Hnf4) in regulating glycogen and triglyceride metabolism. In addition, we identified a number of genes, including Rho guanine nucleotide exchange factor at 64C (RhoGEF64c), Frequenin 2 (Frq2), Prip, and CG1093 that are involved in regulating the unusual star shape of stellate cells. Importantly, the single-nucleus dataset allows visualization of the expression at the organ level of genes involved in ion transport and junctional permeability, providing a systems-level view of the organization and physiological roles of the tubules. Finally, a cross-species analysis allowed us to match the fly kidney cell types to mouse kidney cell types and planarian protonephridia, knowledge that will help the generation of kidney disease models. Altogether, our study provides a comprehensive resource for studying the fly kidney.
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Affiliation(s)
- Jun Xu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Yifang Liu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Hongjie Li
- Department of Biology, Stanford University, Stanford, CA 94305
- HHMI, Stanford University, Stanford, CA 94305
| | - Alexander J. Tarashansky
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Colin H. Kalicki
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Ruei-Jiun Hung
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Yanhui Hu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Aram Comjean
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Sai Saroja Kolluru
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Stephen R. Quake
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Liqun Luo
- Department of Biology, Stanford University, Stanford, CA 94305
- HHMI, Stanford University, Stanford, CA 94305
| | - Andrew P. McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
| | - Julian A. T. Dow
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
- HHMI, Harvard University, Boston, MA 02115
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9
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Dow JAT, Krause SA, Herzyk P. Updates on ion and water transport by the Malpighian tubule. CURRENT OPINION IN INSECT SCIENCE 2021; 47:31-37. [PMID: 33705976 PMCID: PMC9586879 DOI: 10.1016/j.cois.2021.02.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/26/2021] [Accepted: 02/27/2021] [Indexed: 05/29/2023]
Abstract
The Malpighian (renal) tubule is capable of transporting fluid at remarkable rates. This review will focus on recent insights into the mechanisms by which these high rates are achieved and controlled, with particular reference to the tubules of Drosophila melanogaster, in which the combination of physiology and genetics has led to particularly rapid progress. Like many vertebrate epithelia, the Drosophila tubule has specialized cell types, with active cation transport confined to a large, metabolically active principal cell; whereas the smaller intercalated stellate cell controls chloride and water shunts to achieve net fluid secretion. Recently, the genes underlying many of these processes have been identified, functionally validated and localized within the tubule. The imminent arrival of new types of post-genomic data (notably single cell sequencing) will herald an exciting era of new discovery.
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Affiliation(s)
- Julian A T Dow
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Sue Ann Krause
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Pawel Herzyk
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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10
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Jonusaite S, Rodan AR. Molecular basis for epithelial morphogenesis and ion transport in the Malpighian tubule. CURRENT OPINION IN INSECT SCIENCE 2021; 47:7-11. [PMID: 33581351 PMCID: PMC8353009 DOI: 10.1016/j.cois.2021.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 05/04/2023]
Abstract
During development, the insect Malpighian tubule undergoes several programmed morphogenetic events that give rise to the tubule's ability to transport ions and water at unparalleled speed. Studies in Diptera, in particular, have greatly increased our understanding of the molecular pathways underlying embryonic tubule development. In this review, we discuss recent work that has revealed new insights into the molecular players required for the development and maintenance of structurally and functionally intact adult Malpighian tubules. We highlight the contribution of the smooth septate junction (sSJ) proteins to the morphogenesis and transport function of the epithelial cells of the Drosophila melanogaster Malpighian tubule and also discuss new findings on the role of the GATAe transcription factor. We also consider the roles of sSJ proteins in the fly midgut, as compared to the Malpighian tubule, and the importance of cellular context for the functions of these proteins.
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Affiliation(s)
- Sima Jonusaite
- Department of Internal Medicine, Division of Nephrology and Hypertension, and Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Department of Integrative Biology, University of Guelph, Guelph, Ontario NIG 2W1, Canada
| | - Aylin R Rodan
- Department of Internal Medicine, Division of Nephrology and Hypertension, and Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, UT, USA.
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11
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Cohen E, Sawyer JK, Peterson NG, Dow JAT, Fox DT. Physiology, Development, and Disease Modeling in the Drosophila Excretory System. Genetics 2020; 214:235-264. [PMID: 32029579 PMCID: PMC7017010 DOI: 10.1534/genetics.119.302289] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 11/04/2019] [Indexed: 02/06/2023] Open
Abstract
The insect excretory system contains two organ systems acting in concert: the Malpighian tubules and the hindgut perform essential roles in excretion and ionic and osmotic homeostasis. For over 350 years, these two organs have fascinated biologists as a model of organ structure and function. As part of a recent surge in interest, research on the Malpighian tubules and hindgut of Drosophila have uncovered important paradigms of organ physiology and development. Further, many human disease processes can be modeled in these organs. Here, focusing on discoveries in the past 10 years, we provide an overview of the anatomy and physiology of the Drosophila excretory system. We describe the major developmental events that build these organs during embryogenesis, remodel them during metamorphosis, and repair them following injury. Finally, we highlight the use of the Malpighian tubules and hindgut as accessible models of human disease biology. The Malpighian tubule is a particularly excellent model to study rapid fluid transport, neuroendocrine control of renal function, and modeling of numerous human renal conditions such as kidney stones, while the hindgut provides an outstanding model for processes such as the role of cell chirality in development, nonstem cell-based injury repair, cancer-promoting processes, and communication between the intestine and nervous system.
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Affiliation(s)
| | - Jessica K Sawyer
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, and
| | | | - Julian A T Dow
- Institute of Molecular, Cell, and Systems Biology, University of Glasgow, G12 8QQ, United Kingdom
| | - Donald T Fox
- Department of Cell Biology and
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, and
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12
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Jonusaite S, Beyenbach KW, Meyer H, Paululat A, Izumi Y, Furuse M, Rodan AR. The septate junction protein Mesh is required for epithelial morphogenesis, ion transport, and paracellular permeability in the Drosophila Malpighian tubule. Am J Physiol Cell Physiol 2020; 318:C675-C694. [PMID: 31913700 DOI: 10.1152/ajpcell.00492.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Septate junctions (SJs) are occluding cell-cell junctions that have roles in paracellular permeability and barrier function in the epithelia of invertebrates. Arthropods have two types of SJs, pleated SJs and smooth SJs (sSJs). In Drosophila melanogaster, sSJs are found in the midgut and Malpighian tubules, but the functions of sSJs and their protein components in the tubule epithelium are unknown. Here we examined the role of the previously identified integral sSJ component, Mesh, in the Malpighian tubule. We genetically manipulated mesh specifically in the principal cells of the tubule at different life stages. Tubules of flies with developmental mesh knockdown revealed defects in epithelial architecture, sSJ molecular and structural organization, and lack of urine production in basal and kinin-stimulated conditions, resulting in edema and early adult lethality. Knockdown of mesh during adulthood did not disrupt tubule epithelial and sSJ integrity but decreased the transepithelial potential, diminished transepithelial fluid and ion transport, and decreased paracellular permeability to 4-kDa dextran. Drosophila kinin decreased transepithelial potential and increased chloride permeability, and it stimulated fluid secretion in both control and adult mesh knockdown tubules but had no effect on 4-kDa dextran flux. Together, these data indicate roles for Mesh in the developmental maturation of the Drosophila Malpighian tubule and in ion and macromolecular transport in the adult tubule.
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Affiliation(s)
- Sima Jonusaite
- Division of Nephrology and Hypertension, Department of Internal Medicine, and Molecular Medicine Program, University of Utah, Salt Lake City, Utah
| | - Klaus W Beyenbach
- Division of Animal Physiology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Heiko Meyer
- Division of Zoology and Developmental Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany
| | - Achim Paululat
- Division of Zoology and Developmental Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany
| | - Yasushi Izumi
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Okazaki, Japan
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Okazaki, Japan
| | - Aylin R Rodan
- Division of Nephrology and Hypertension, Department of Internal Medicine, and Molecular Medicine Program, University of Utah, Salt Lake City, Utah.,Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
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Specialized stellate cells offer a privileged route for rapid water flux in Drosophila renal tubule. Proc Natl Acad Sci U S A 2020; 117:1779-1787. [PMID: 31907321 PMCID: PMC6983416 DOI: 10.1073/pnas.1915943117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Insects are highly successful, in part through an excellent ability to osmoregulate. The renal (Malpighian) tubules can secrete fluid faster on a per-cell basis than any other epithelium, but the route for these remarkable water fluxes has not been established. In Drosophila melanogaster, we show that 4 genes of the major intrinsic protein family are expressed at a very high level in the fly renal tissue: the aquaporins (AQPs) Drip and Prip and the aquaglyceroporins Eglp2 and Eglp4 As predicted from their structure, and by their transport function by expressing these proteins in Xenopus oocytes, Drip, Prip, and Eglp2 show significant and specific water permeability, whereas Eglp2 and Eglp4 show very high permeability to glycerol and urea. Knockdowns of any of these genes result in impaired hormone-induced fluid secretion. The Drosophila tubule has 2 main secretory cell types: active cation-transporting principal cells, wherein the aquaglyceroporins localize to opposite plasma membranes, and small stellate cells, the site of the chloride shunt conductance, with these AQPs localizing to opposite plasma membranes. This suggests a model in which osmotically obliged water flows through the stellate cells. Consistent with this model, fluorescently labeled dextran, an in vivo marker of membrane water permeability, is trapped in the basal infoldings of the stellate cells after kinin diuretic peptide stimulation, confirming that these cells provide the major route for transepithelial water flux. The spatial segregation of these components of epithelial water transport may help to explain the unique success of the higher insects in regulating their internal environments.
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Kolosov D, O'Donnell MJ. Mechanisms and regulation of chloride transport in the Malpighian tubules of the larval cabbage looper Trichoplusia ni. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 116:103263. [PMID: 31682921 DOI: 10.1016/j.ibmb.2019.103263] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 10/22/2019] [Accepted: 10/29/2019] [Indexed: 06/10/2023]
Abstract
Malpighian tubules (MTs) and the hindgut together constitute the excretory system of insects. Larvae of lepidopterans (butterflies and moths) demonstrate the so-called cryptonephric arrangement, where the distal blind end of each MT is embedded into the rectal complex. The rest of the free tubule is modified into several distinct regions that differ greatly in the transport of cations and water. However, relatively little is known about the transport of counter-anions (e.g., Cl- and HCO3-) by the MTs of lepidopteran larvae. In the current study we used ion-selective microelectrodes to characterize Cl- transport in the distinct regions of the free MT of the larval Trichoplusia ni. Firstly, we note that Cl- transport in the MTs is sensitive to the Cl- concentration of the bathing saline, and several regions of the MTs are capable of either secreting or reabsorbing Cl-. In the distal ileac plexus (DIP), a region previously characterized by cellular heterogeneity and its ability to switch between cation secretion and reabsorption, principal cells (PCs) toggled between Cl- reabsorption (in high-Cl- saline) and Cl- secretion (in low-Cl- saline). In contrast, secondary cells (SCs) in the DIP secreted Cl- regardless of saline Cl- concentration. Mechanistically, we have detected a number of 'leak' and ligand-gated Cl- channels (ClC) and demonstrated that Cl- channels are involved in Cl- secretion. Additionally, we demonstrated that the lumen-positive transepithelial potential increased in response to glycine. Using the scanning ion-selective electrode technique we demonstrated that glycine stimulated Cl- secretion by SCs, but not by PCs. In contrast, when MTs were deprived of glycine, a decrease in Cl- secretion, coupled with a decrease in the TEP, was observed. In contrast to the effects of glycine, an active dose of helicokinin reduced Cl- secretion by PCs, but not by SCs. Lastly, we detected expression of chloride-bicarbonate exchangers (CBE) in all regions of the free tubule. Scans of H+ transport across the tubule indicated that base equivalents are likely reabsorbed across the ileac plexus. Blocking ClC or CBE led to secretion of a more basic fluid, indicating lack of base reabsorption. We suggest that the transport of Cl- in the MTs of larval lepidopterans (i) may be correlated with the reabsorption of base, (ii) may be sensitive to Cl- concentration in the haemolymph, and (iii) could be regulated by helicokinin and glycine.
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Affiliation(s)
- Dennis Kolosov
- Department of Biology, McMaster University, 1280 Main St West, Hamilton, ON, L8S4K1, Canada.
| | - Michael J O'Donnell
- Department of Biology, McMaster University, 1280 Main St West, Hamilton, ON, L8S4K1, Canada
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