scholarly journals Characterization of a set of abdominal neuroendocrine cells that regulate stress physiology using colocalized diuretic peptides in Drosophila

2017 ◽  
Author(s):  
Meet Zandawala ◽  
Richard Marley ◽  
Shireen A. Davies ◽  
Dick R. Nässel
Keyword(s):  
Stress Responses ◽  
Water Retention ◽  
Fluid Secretion ◽  
Cell Types ◽  
Neurosecretory Cells ◽  
Malpighian Tubules ◽  
Neuroendocrine Cells ◽  
Signaling Systems ◽  
Diuretic Hormone ◽  
Functional Relations

AbstractMultiple neuropeptides are known to regulate water and ion balance in Drosophila melanogaster. Several of these peptides also have other functions in physiology and behavior. Examples are corticotropin-releasing factor-like diuretic hormone (diuretic hormone 44; DH44) and leucokinin (LK), both of which induce fluid secretion by Malpighian tubules (MTs), but also regulate stress responses, feeding, circadian activity and other behaviors. Here, we investigated the functional relations between the LK and DH44 signaling systems. DH44 and LK peptides are only colocalized in a set of abdominal neurosecretory cells (ABLKs). Targeted knockdown of each of these peptides in ABLKs leads to increased resistance to desiccation, starvation and ionic stress. Food ingestion is diminished by knockdown of DH44, but not LK, and water retention is increased by LK knockdown only. Thus, the two colocalized peptides display similar systemic actions, but differ with respect to regulation of feeding and body water retention. We also demonstrated that DH44 and LK have additive effects on fluid secretion by MTs. It is likely that the colocalized peptides are coreleased from ABLKs into the circulation and act on the tubules where they target different cell types and signaling systems to regulate diuresis and stress tolerance. Additional targets seem to be specific for each of the two peptides and subserve regulation of feeding and water retention. Our data suggest that the ABLKs and hormonal actions are sufficient for many of the known DH44 and LK functions, and that the remaining neurons in the CNS play other functional roles.

THE EFFECTS OF MANDUCA SEXTA DIURETIC HORMONE ON FLUID TRANSPORT BY THE MALPIGHIAN TUBULES AND CRYPTONEPHRIC COMPLEX OF MANDUCA SEXTA

1993 ◽  
Vol 178 (1) ◽  
pp. 231-243 ◽  
Author(s):  
N. Audsley ◽  
G. M. Coast ◽  
D. A. Schooley
Keyword(s):  
Cyclic Amp ◽  
Manduca Sexta ◽  
Fluid Transport ◽  
Basal Membrane ◽  
Fluid Secretion ◽  
Hormonal Control ◽  
Malpighian Tubules ◽  
Proximal Tubules ◽  
Fluid Absorption ◽  
Diuretic Hormone

1. Manduca sexta diuretic hormone (Mas-DH) stimulates fluid secretion by adult Malpighian tubules of M. sexta, demonstrating its site of diuretic action in M. sexta for the first time. It was not possible to develop a suitable bioassay to measure fluid secretion in larval proximal tubules. 2. Mas-DH has an antidiuretic action on the cryptonephric complex of larval M. sexta because it increases fluid absorption from the rectum. It appears that in this complex Mas-DH is acting on a Na+/K+/2Cl- co-transporter, presumably on the basal membrane of the cryptonephric Malpighian tubules, because Mas-DH-stimulated fluid absorption by the cryptonephric complex is inhibited by bumetanide or the removal of Cl-, Na+ or K+ from the haemolymph side of the tissue. This is the first demonstration of hormonal control of fluid absorption by the cryptonephric complex. 3. Concomitant with the stimulation of fluid transport, Mas-DH increases the amount of cyclic AMP secreted by adult Malpighian tubules and the cryptonephric complex. In addition, Mas-DH promotes cyclic AMP production by the larval proximal tubules.

Insect-Like Characteristics of the Malpighian Tubules of a Non-Insect: Fluid Secretion in the Centipede Uthobius Forficatus (Myriapoda: Chilopoda)

1991 ◽  
Vol 158 (1) ◽  
pp. 165-180
Author(s):  
ANGELA WENNING ◽  
U. T. E. GREISINGER ◽  
JACQUES P. PROUX
Keyword(s):  
Cyclic Amp ◽  
Flow Rate ◽  
Fluid Secretion ◽  
Urine Flow ◽  
Malpighian Tubules ◽  
Urine Flow Rate ◽  
Dibutyryl Cyclic Amp ◽  
Diuretic Hormone ◽  
Urine Formation ◽  
Lithobius Forficatus

Fluid secretion by isolated upper and lower portions of Malpighian tubules in the centipede Lithobius forficatus L. was studied. Ion requirements, cellular and transepithelial potentials, dependence on external osmolality and the effects of an insect diuretic factor and transport-active drugs were investigated. Unlike many insects, L. forficatus exhibited strongly Na+-dependent, K+-independent urine formation. However, as in many insects, upper and lower tubule portions from L. forficatus produced a K+-enriched, hypertonic fluid, and the transepithelial potential was positive with respect to the haemolymph. Furthermore, furosemide (5×10−4moll−1) reversibly inhibited urine formation. Ouabain, even at 10−3moll−1, had little effect on urine flow rate in upper tubules but inhibited secretion in lower tubules, albeit not completely. Locust diuretic hormone (at 10−7moll−1) enhanced fluid secretion in L. forficatus, but its action was not mimicked by dibutyryl cyclic AMP. The results suggest that some characteristics attributed exclusively to insects are common to non-insect arthropods.

scholarly journals Single nucleus RNASeq profiling of mouse lung: reduced dissociation bias and improved detection of rare cell types compared with single cell RNASeq

2020 ◽  
Author(s):  
Jeffrey R Koenitzer ◽  
Haojia Wu ◽  
Jeffrey J Atkinson ◽  
Steven L Brody ◽  
Benjamin D Humphreys
Keyword(s):  
Single Cell ◽  
Stress Responses ◽  
Cell Types ◽  
Neuroendocrine Cells ◽  
Cdna Libraries ◽  
Mouse Lung ◽  
Cell Detection ◽  
Mrna Levels ◽  
Gene Detection ◽  
Single Nucleus

AbstractRATIONALESingle cell RNA-sequencing (scRNASeq) has led to multiple recent advances in our understanding of lung biology and pathophysiology, but utility is limited by the need for fresh samples, loss of cell types due to death or inadequate dissociation, and the induction of transcriptional stress responses during tissue digestion. Single nucleus RNASeq (snRNASeq) has addressed these deficiencies in some other tissues, but no protocol exists for lung. We sought to develop such a protocol and compare its results with scRNA-seq.METHODSSingle nucleus suspensions were prepared rapidly (45 min) from two mouse lungs in lysis buffer on ice while a single cell suspension from an additional mouse lung was generated using a combination of enzymatic and mechanical dissociation (1.5 h). Cells and nuclei were processed using the 10x Genomics platform, and following sequencing of cDNA libraries single cell data was analyzed by Seurat.RESULTS16,656 single nucleus and 11,934 single cell transcriptomes were generated. Despite reduced mRNA levels in nuclei vs. cells, gene detection rates were equivalent in snRNASeq and scRNASeq (∼1,750 genes and 3,000 UMI per cell) when mapping intronic and exonic reads. snRNASeq identified a much greater proportion of epithelial cells than scRNASeq (46% vs 2% of total), including basal and neuroendocrine cells, while reducing immune cells from 54% to 15%. snRNASeq transcripts are enriched for transcription factors and signaling proteins, with reduced detection of housekeeping genes, mitochondrial genes, and artifactual stress response genes. Both techniques improved mesenchymal cell detection over previous studies, and analysis of fibroblast diversity showed two transcriptionally distinct populations of Col13a1+ cells, termed Bmper+ and Brinp1+ fibroblasts. To define homeostatic signaling relationships among cell types, receptor-ligand mapping of was performed for alveolar compartment cells using snRNASeq data, revealing complex interplay among epithelial, mesenchymal, and capillary endothelial cells.CONCLUSIONSingle nucleus RNASeq can be readily applied to snap frozen, archival murine lung samples, improves dissociation bias, eliminates artifactual gene expression and provides similar gene detection compared to scRNASeq.

scholarly journals SYNERGISM OF HORMONES CONTROLLING EPITHELIAL FLUID TRANSPORT IN AN INSECT

1993 ◽  
Vol 174 (1) ◽  
pp. 65-80 ◽  
Author(s):  
S. H. P. Maddrell ◽  
W. S. Herman ◽  
J. A. Farndale ◽  
J A Riegel
Keyword(s):  
Adenylate Cyclase ◽  
Fluid Transport ◽  
Fluid Secretion ◽  
Rapid Onset ◽  
Threshold Concentration ◽  
Malpighian Tubules ◽  
Dependent Manner ◽  
Response Curves ◽  
Diuretic Hormone ◽  
Dose Dependent

Forskolin stimulates rapid fluid secretion by the Malpighian tubules of Rhodnius prolixus at concentrations above 5x10–6 mol l-1. In the presence of a threshold concentration of forskolin, the tubules are 30–50 times more sensitive to 5-hydroxytryptamine (5-HT) than in its absence. Similar synergism is seen between 5-HT and extracts of the mesothoracic ganglionic mass (which is rich in the peptide diuretic hormone, DH) and between 5-HT and samples of haemolymph, also rich in peptide DH, from fed insects 1–2 h after feeding. The dose-response curves for mixtures of forskolin and 5-HT and of peptide DH and 5-HT are all very steep, approximately five times steeper than for any one stimulant alone. Forskolin, 5-HT and extracts of the ganglionic mass all stimulated adenylate cyclase from broken membrane preparations from the Malpighian tubules in a dose-dependent manner and at doses similar to those required to stimulate fluid secretion by intact tubules. Mixtures of ganglionic extract and 5- HT stimulated adenylate cyclase activity in a synergistic fashion. Injections into fifth-instar Rhodnius, 24 h before feeding, of 5,7-dihydroxytryptamine, which is known to block or reduce 5-HT release, caused delays in the onset of the consequent diuresis or prevented it altogether. This is consistent with the proposal that the rapid onset of diuresis after feeding is caused by the simultaneous release of 5-HT and peptide DH acting synergistically.

scholarly journals ION AND FLUID SECRETION BY DIFFERENT SEGMENTS OF THE MALPIGHIAN TUBULES OF THE BLACK FIELD CRICKET TELEOGRYLLUS OCEANICUS

1993 ◽  
Vol 177 (1) ◽  
pp. 1-22
Author(s):  
A. T. Marshall ◽  
P. Cooper ◽  
G. D. Rippon ◽  
A. E. Patak
Keyword(s):  
Cyclic Amp ◽  
Fluid Secretion ◽  
Distal Segment ◽  
Malpighian Tubules ◽  
Secretion Rate ◽  
Osmotic Concentration ◽  
Corpora Cardiaca ◽  
Diuretic Hormone ◽  
High Concentrations ◽  
Tubule Fluid

Cricket Malpighian tubules have two morphologically distinct segments, a thin distal segment, which occupies approximately 10 % of the total tubule length, and a main segment. The two segments differ in secretion rates and response to corpora cardiaca extract. The secreted fluids differ in osmotic concentration and elemental composition. The distal segment secretes fluid at a rate (per mm length) which is approximately twice that of the main segment under control conditions. After stimulation by corpora cardiaca extract (Cc) the rate from the main segment approximately doubles whilst the distal segment rate remains unchanged. Fluid from the main segment and the whole tubule is slightly hypo-osmotic to the medium (5–11 mosmol kg-1) under control conditions, whereas that from the distal segment is slightly hyperosmotic (12 mosmol kg-1). On stimulation with Cc, the whole tubule fluid becomes slightly hyperosmotic (12 mosmol kg-1), that from the main segment remains slightly hypo-osmotic (3 mosmol kg-1) but fluid from the distal segment becomes very hyperosmotic (55 mosmol kg-1). Differences between the tubule fluid and the medium osmolality are indicated in parentheses. Fluid from the main segment has high concentrations of K (166 mmol l-1), Cl (111 mmol l-1), Na (41 mmol l-1) and P (83 mmol l-1), whereas that from the distal segment has high concentrations of K (101 mmol l-1) and Cl (137 mmol l-1). On stimulation with Cc, the elemental concentrations in fluids from the main segments and whole tubules do not change significantly but the K and Cl concentrations in distal segment fluid increase (182 and 188 mmol l-1 respectively). The Mg present in whole tubule fluid is derived largely from the distal segment. The ionic composition accounts for the observed osmotic concentrations in fluid from whole tubules, main segments and stimulated distal segments, but not for the concentrations in fluid from unstimulated distal segments. The fluid from unstimulated distal segments contains an unidentified organic solute accounting for approximately 90 mosmol kg-1 of the osmotic concentration. The distal segment contributes 22 % and 11 % of the fluid volume, 26 % Cl, 14 % K and 12 % Cl, 11 % K in control and Cc-stimulated tubules respectively. Considerably higher values are observed in individual tubules. The distal segment makes a significant contribution to the total ion output of the tubule. The cyclic AMP content of tubule segments treated with corpora cardiaca extract was found to increase in both main and distal segments. When expressed in terms of protein content there was no difference between segments. However, in terms of total cell volume, the cells of the distal segment had a tenfold greater cyclic AMP content than those of the main segment. This is consistent with a 10- to 20-fold higher secretion rate of K by the distal segment. It is suggested that the distal segment, whilst having a higher length-specific fluid secretion rate than the main segment, is, nevertheless, concerned primarily with ion and solute secretion since it is unresponsive to diuretic hormone. The prime role of the main segment, which does respond to diuretic hormone, is fluid secretion. There appear to be major differences in hydraulic conductivity between the two segments.

scholarly journals A neuroendocrine pathway modulating osmotic stress in Drosophila

2019 ◽  
Author(s):  
Meet Zandawala ◽  
Thomas Nguyen ◽  
Marta Balanyà Segura ◽  
Helena A. D. Johard ◽  
Mirjam Amcoff ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Responses ◽  
Desiccation Tolerance ◽  
Fat Body ◽  
Neurosecretory Cells ◽  
Malpighian Tubules ◽  
Ionic Balance ◽  
Chill Coma ◽  
Energy Mobilization ◽  
Neuroendocrine Axis

AbstractEnvironmental factors challenge the physiological homeostasis in animals, thereby evoking stress responses. Various mechanisms have evolved to counter stress at the organism level, including regulation by neuropeptides. Although much progress has been made on the mechanisms and neuropeptides influencing nutritional stress, relatively little is known about the factors and pathways regulating osmotic and ionic stresses. Here, we uncover the neuropeptide Corazonin (Crz) as a neuroendocrine factor that modulates the release of an osmoregulatory peptide, CAPA, to regulate tolerance to osmotic and ionic stress. Both knockdown of Crz and acute injections of Crz peptide impact desiccation tolerance and recovery from chill-coma. Comprehensive mapping of the Crz receptor (CrzR) expression identified three pairs of Capa-expressing neurons (Va neurons) in the ventral nerve cord that mediate these effects of Crz. We further show that Crz is released during dry starvation (desiccation) and acts to restore homeostasis by inhibiting CAPA release via inhibition of cAMP production in Va neurons. Finally, knockdown of CrzR in Va neurons also affects CAPA release, and consequently influences desiccation tolerance and chill-coma recovery, considered proxies for diuretic state. Thus, Crz modulates Va neurons to maintain osmotic and ionic homeostasis, which in turn influences stress tolerance. Taken together with our previous work showing that systemic Crz signaling acts to restore nutrients levels by promoting food search and feeding, we propose that Crz signaling also ensures osmotic homeostasis by inhibiting the anti-diuretic CAPA peptides. Thus, Crz ameliorates stress-associated physiology through systemic modulation of both peptidergic neurosecretory cells and the fat body in Drosophila.Author summaryInsects are among the largest groups of animals and have adapted to inhabit almost all environments on Earth. Their success in surviving extreme conditions stems largely from their ability to withstand environmental stress, such as desiccation and cold. However, the neural mechanisms that are responsible for coordinating responses to counter these stresses are largely unknown. To address this, we delineate a neuroendocrine axis utilizing the neuropeptides Corazonin (Crz) and CAPA, that coordinate responses to metabolic and osmotic stress. We show that Crz modulates the release of an anti-diuretic peptide, CAPA from a set of neurosecretory cells. CAPA in turn influences osmotic and ionic balance via actions on the Malpighian tubules (the insect analogs of the kidney) and the intestine. Taken together with earlier work, our data suggest that Crz acts to restore metabolic homeostasis at starvation and as a cosenquence of energy mobilization and ensuing metabolic water production, fluid balance needs to be adjusted and therefore CAPA release is inhibited. Hence, this work provides a mechanistic understanding of the neuroendocrine mitigation of metabolic and osmotic stress by two peptide systems.

scholarly journals Specialized stellate cells offer a privileged route for rapid water flux in Drosophila renal tubule

2020 ◽  
Vol 117 (3) ◽  
pp. 1779-1787 ◽  
Author(s):  
Pablo Cabrero ◽  
Selim Terhzaz ◽  
Anthony J. Dornan ◽  
Saurav Ghimire ◽  
Heather L. Holmes ◽  
...  
Keyword(s):  
Water Permeability ◽  
Plasma Membranes ◽  
Water Flux ◽  
Stellate Cells ◽  
Fluid Secretion ◽  
Cell Types ◽  
Renal Tissue ◽  
Malpighian Tubules ◽  
Very High

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.

scholarly journals 5-Hydroxytryptamine: a second diuretic hormone in Rhodnius prolixus

1991 ◽  
Vol 156 (1) ◽  
pp. 557-566 ◽  
Author(s):  
S. H. Maddrell ◽  
W. S. Herman ◽  
R. L. Mooney ◽  
J. A. Overton
Keyword(s):  
Salivary Glands ◽  
Malpighian Tubule ◽  
Peptide Hormone ◽  
Fluid Secretion ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Biologically Active ◽  
Diuretic Hormone ◽  
Naturally Occurring ◽  
Tubule Fluid

Bioassays of 5-hydroxytryptamine (5-HT) in fifth-instar Rhodnius prolixus haemolymph using Calliphora salivary glands indicate that: (1) biologically active 5-HT is present, (2) in unfed animals there is not enough 5-HT to stimulate Malpighian tubule fluid secretion, and (3) there is enough 5-HT soon after the initiation of feeding to stimulate rapid tubule secretion. The 5-HT receptor antagonists ketanserin and spiperone reversibly and selectively inhibit 5-HT-induced fluid secretion, indicating the presence of specific 5-HT receptors on Rhodnius Malpighian tubules. The data provide evidence that 5-HT is a naturally occurring hormone acting with a previously described peptide hormone to regulate diuresis in this species.

Fine Structure of the Malpighian Tubules of the Mosquito, Culex pipiens

1971 ◽  
Vol 29 ◽  
pp. 402-403
Author(s):  
Brendan Clifford
Keyword(s):  
Fine Structure ◽  
Culex Pipiens ◽  
Stellate Cell ◽  
Malpighian Tubule ◽  
Cell Types ◽  
Instar Larva ◽  
Malpighian Tubules ◽  
Calliphora Erythrocephala ◽  
Distinct Cell ◽  
Basal Plasma

An ultrastructural investigation of the Malpighian tubules of the fourth instar larva of Culex pipiens was undertaken as part of a continuing study of the fine structure of transport epithelia.Each of the five Malpighian tubules was found to be morphologically identical and regionally undifferentiated. Two distinct cell types, the primary and stellate, were found intermingled along the length of each tubule. The ultrastructure of the stellate cell was previously described in the Malpighian tubule of the blowfly, Calliphora erythrocephala by Berridge and Oschman.The basal plasma membrane of the primary cell is extremely irregular, giving rise to a complex interconnecting network of basal channels. The compartments of cytoplasm entrapped within this system of basal infoldings contain mitochondria, free ribosomes, and small amounts of rough endoplasmic reticulum. The mitochondria are distinctive in that the cristae run parallel to the long axis of the organelle.

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