scholarly journals Localization and Bioreactivity of Cysteine-Rich Secretions in the Marine Gastropod Nucella lapillus

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 276
Author(s):  
Mariaelena D’Ambrosio ◽  
Cátia Gonçalves ◽  
Mariana Calmão ◽  
Maria Rodrigues ◽  
Pedro M. Costa
Keyword(s):  
Salivary Glands ◽  
Digestive Gland ◽  
Crude Protein ◽  
Ex Vivo ◽  
Gill Tissue ◽  
Marine Biodiversity ◽  
Nucella Lapillus ◽  
Promising Target ◽  
Toxin Secretion ◽  
Molecular Damage

Marine biodiversity has been yielding promising novel bioproducts from venomous animals. Despite the auspices of conotoxins, which originated the paradigmatic painkiller Prialt, the biotechnological potential of gastropod venoms remains to be explored. Marine bioprospecting is expanding towards temperate species like the dogwhelk Nucella lapillus, which is suspected to secrete immobilizing agents through its salivary glands with a relaxing effect on the musculature of its preferential prey, Mytilus sp. This work focused on detecting, localizing, and testing the bioreactivity of cysteine-rich proteins and peptides, whose presence is a signature of animal venoms and poisons. The highest content of thiols was found in crude protein extracts from the digestive gland, which is associated with digestion, followed by the peribuccal mass, where the salivary glands are located. Conversely, the foot and siphon (which the gastropod uses for feeding) are not the main organs involved in toxin secretion. Ex vivo bioassays with Mytilus gill tissue disclosed the differential bioreactivity of crude protein extracts. Secretions from the digestive gland and peribuccal mass caused the most significant molecular damage, with evidence for the induction of apoptosis. These early findings indicate that salivary glands are a promising target for the extraction and characterization of bioactive cysteine-rich proteinaceous toxins from the species.

Experiments with P32 and I131 on Species of Helix, Arion, and Agriolimax

1952 ◽  
Vol s3-93 (22) ◽  
pp. 133-146
Author(s):  
VERA FRETTER
Keyword(s):  
Salivary Glands ◽  
Digestive Gland ◽  
Radioactive Iodine ◽  
Helix Pomatia ◽  
Relative Activity ◽  
The Body ◽  
Ionic Exchange ◽  
Digestive Cells ◽  
Metabolic Activities ◽  
Calcium Cells

If Helix aspersa, H. pomatia, Arion hortensis, and Agriolimax agrestis be fed on a diet which contains P32, autoradiographs show that the isotope is taken up by the digestive and lime cells of the digestive gland. From the formermost of it passes to the haemocoel, though some is retained for immediate metabolic activities; in the lime cells it is stored in calcium spherules. A very small amount of the tracer enters the body through the wall of the oesophagus, and more through the intestine, this site of diffusion being most pronounced directly after hibernation. The P33 in the haemocoel is dispersed to all tissues: all of them take up a little; in some it becomes concentrated. Concentrations appear in the nerve ring, the mucous and salivary glands, the odontophore and certain cells of the mantle. In the nervous system deposits are heavy around the fibres and slight in the cytoplasm of the cells; they indicate a compound, soluble in alcohol, which may be phospholipine, associated with medullated nerves. The phosphorus in mucous cells, most pronounced in the pedal and salivary glands, may be combined with the calcium which stabilizes mucus and prevents its rapid dispersal. The incorporation of isotope into the developing tooth of the radula indicates the relative activity of the basoblasts and cuspidoblasts: in early development of a tooth the basoblast secretes more actively, but as it becomes effete secretion by the cuspidoblast is accelerated. When the tooth is liberated from the latter there is no further addition to its substance. Phosphorus deposits in the mantle are in the calcium cells which secrete the shell. Here, as in the lime cells, and around certain blood-vessels, excess may be stored as calcium phosphate; reserves in the digestive gland are the largest. Amoebocytes concerned with the regeneration of the shell of Helix pomatia and H. aspersa carry the tracer element, and some of it is deposited in the shell. Also in the slug the tracer is transported by amoebocytes. Radioactive iodine in the lumen of the gut is taken up most readily by digestive cells; some enters the lime cells. Only in sparing quantities does this isotope pass from the gland to the rest of the body, and this entry is presumably associated with ionic exchange. It is not accumulated in any cell, except in the kidney whence it is excreted; it leaves the digestive cells to pass from the body with the faeces.

scholarly journals Murine Cytomegalovirus Spread Depends on the Infected Myeloid Cell Type

2019 ◽  
Vol 93 (15) ◽  
Author(s):  
Helen E. Farrell ◽  
Kimberley Bruce ◽  
Clara Lawler ◽  
Philip G. Stevenson
Keyword(s):  
Dendritic Cells ◽  
Salivary Gland ◽  
Salivary Glands ◽  
Olfactory Epithelium ◽  
Ex Vivo ◽  
Myeloid Cells ◽  
Murine Cytomegalovirus ◽  
Cell Type ◽  
High Endothelial Venules ◽  
Brown Adipose

ABSTRACTCytomegaloviruses (CMVs) colonize blood-borne myeloid cells. Murine CMV (MCMV) spreads from the lungs via infected CD11c+cells, consistent with an important role for dendritic cells (DC). We show here that MCMV entering via the olfactory epithelium, a natural transmission portal, also spreads via infected DC. They reached lymph nodes, entered the blood via high endothelial venules, and then entered the salivary glands, driven by constitutive signaling of the viral M33 G protein-coupled receptor (GPCR). Intraperitoneal infection also delivered MCMV to the salivary glands via DC. However, it also seeded F4/80+infected macrophages to the blood; they did not enter the salivary glands or require M33 for extravasation. Instead, they seeded infection to a range of other sites, including brown adipose tissue (BAT). Peritoneal cells infectedex vivothen adoptively transferred showed similar cell type-dependent differences in distribution, with abundant F4/80+cells in BAT and CD11c+cells in the salivary glands. BAT colonization by CMV-infected cells was insensitive to pertussis toxin inhibition of the GPCR signaling through Gi/osubstrate, whereas salivary gland colonization was sensitive. Since salivary gland infection required both M33 and Gi/o-coupled signaling, whereas BAT infection required neither, these migrations were mechanistically distinct. MCMV spread from the lungs or nose depended on DC, controlled by M33. Infecting other monocyte populations resulted in unpredictable new infections.IMPORTANCECytomegaloviruses (CMVs) spread through the blood by infecting monocytes, and this can lead to disease. With murine CMV (MCMV) we can track infected myeloid cells and so understand how CMVs spread. Previous experiments have injected MCMV into the peritoneal cavity. MCMV normally enters mice via the olfactory epithelium. We show that olfactory infection spreads via dendritic cells, which MCMV directs to the salivary glands. Peritoneal infection similarly reached the salivary glands via dendritic cells. However, it also infected other monocyte types, and they spread infection to other tissues. Thus, infecting the “wrong” monocytes altered virus spread, with potential to cause disease. These results provide a basis for understanding how the monocyte types infected by human CMV might promote different infection outcomes.

The ultrastructure of the fore-gut of the redia of Parorchis acanthus Nicoll (Digenea: Philophthalmidae) from the digestive gland of Nucella lapillus L

Parasitology ◽  
1983 ◽  
Vol 87 (1) ◽  
pp. 151-158 ◽  
Author(s):  
F. Gwendolen Rees
Keyword(s):  
Digestive Gland ◽  
Body Surface ◽  
Buccal Cavity ◽  
The Body ◽  
Unusual Feature ◽  
Nucella Lapillus ◽  
Cytoplasmic Inclusions ◽  
Parorchis Acanthus ◽  
Ventral Nucleus ◽  
Rapid Passage

SUMMARYThe fore-gut of the redia of Parorchis acanthus is ingestive in function. It consists of a buccal cavity, suctorial pharynx and an oesophagus divided into anterior and posterior regions. The syncytial lining is continuous with that covering the body surface, except for the posterior region of the oesophagus which is lined by a separate syncytium. This latter has different cytoplasmic inclusions and the unusual feature of a single ventral nucleus in the outer cytoplasmic epidermis. Intrinsic and extrinsic muscles are responsible, respectively, for the fairly rapid passage of food through the fore-gut and for support. Secretion bodies in the epidermis are probably discharged into the lumen and pass with food into the intestine where they may be involved in extracellular digestion. Young rediae feed mainly by mouth while older, immotile rediae absorb nutrients mainly through the body surface.

The ultrastructure of the intestine of the redia of Parorchis acanthus Nicoll (Digenea: Philophthalmidae) from the digestive gland of Nucella lapillus L

Parasitology ◽  
1983 ◽  
Vol 87 (1) ◽  
pp. 159-166 ◽  
Author(s):  
F. Gwendolen Rees
Keyword(s):  
Plasma Membrane ◽  
Digestive Gland ◽  
Lipid Bodies ◽  
Nucella Lapillus ◽  
Dense Bodies ◽  
Parenchyma Cells ◽  
Basal Plasma Membrane ◽  
Basal Plasma ◽  
Parorchis Acanthus

SUMMARYThe intestine of the redia of Parorchis acanthus is lined by a gastrodermis and surrounded by inner longitudinal and outer circular muscles. The gastrodermis consists of alternating rings of dense and lucent cells of similar dimensions, with similar nuclei and with microvilli on the lumenal surface. The dense cells contain ribosomes, dense secretion bodies, vesicles and a few lipid bodies. Ribosomes, dense bodies and lipids are absent from the lucent cells but vesicles are present which, as in the dense cells, pass along the microvilli to be discharged into the lumen. Both types of cells are secretory, absorptive and transportive. The lucent cells, in addition, store glycogen in areas of the cytoplasm devoid of organelles. Tips of processes from the parenchyma cells are engulfed in pockets in the basal plasma membrane, of both, facilitating transport of nutrients from the gastrodermis directly into the parenchyma

Les osidases digestives de l'escargot Helix aspersa: localisations et variations en fonction de l'état nutritionnel

1992 ◽  
Vol 70 (11) ◽  
pp. 2234-2241 ◽  
Author(s):  
Maryvonne Charrier ◽  
Corinne Rouland
Keyword(s):  
Salivary Glands ◽  
Digestive Tract ◽  
Digestive Gland ◽  
Bacterial Flora ◽  
Helix Aspersa ◽  
Similar Distribution ◽  
Synergistic Activity

Osidases were studied in brown garden snails, Helix aspersa Müller, fed or starved for 4 or 7 weeks. The digestive tract was divided into seven regions: oesophagus, crop, stomach, intestine, rectum, salivary glands, and digestive gland. The results revealed the presence of a large number of enzymes that attack alimentary carbohydrates. However, α-heterosides and starch were poorly hydrolysed, and amylase was not derived from saliva. Enzymatic secretions continued in snails subjected to 7 weeks of starvation and accumulated in the stomach, while these enzymes were active mainly in the oesophagus and the crop during nutrition. Several hypotheses are presented, including that the most active enzymes, mannanases and cellulases, may be secreted both by the salivary glands and by the digestive gland. A similar distribution is postulated for two oligosaccharidases, maltase and saccharase. Since a bacterial flora exists in the digestive tract, we also consider the possibility of a synergistic activity between osidases from the snail and those originating from the microflora.

scholarly journals A functionally distinct neutrophil landscape in severe COVID-19 reveals opportunities for adjunctive therapies

2021 ◽  
Author(s):  
Rachita Panda ◽  
Fernanda Vargas E Silva Castanheira ◽  
Jared Schlechte ◽  
Bas GJ Surewaard ◽  
Hanjoo Brian Shim ◽  
...  
Keyword(s):  
Single Cell Analysis ◽  
Ex Vivo ◽  
Diffuse Alveolar Damage ◽  
Neutrophil Activation ◽  
Effector Functions ◽  
Immune Mediated ◽  
Promising Target ◽  
Life Threatening ◽  
Outstanding Question ◽  
Neutrophil Response

Acute respiratory distress syndrome (ARDS) is a life-threatening syndrome of respiratory failure and diffuse alveolar damage that results from dysregulated local and systemic immune activation, causing pulmonary vascular, parenchymal and alveolar damage. SARS-CoV-2 infection has become the dominant cause of ARDS worldwide, and emerging evidence implicates neutrophils and their cytotoxic arsenal of effector functions as central drivers of immune-mediated lung injury in COVID-19 ARDS. However, a key outstanding question is whether COVID-19 drives a unique program of neutrophil activation or effector functions that contributes to the severe pathogenesis of this pandemic illness, and whether this unique neutrophil response can be targeted to attenuate disease. Using a combination of high-dimensional single cell analysis and ex vivo functional assays of neutrophils from patients with COVID-19 ARDS compared to non-COVID ARDS (caused by bacterial pneumonia), we identified a functionally distinct landscape of neutrophil activation in COVID-19 ARDS that was intrinsically programmed during SARS-CoV-2 infection. Furthermore, neutrophils in COVID-19 ARDS were functionally primed to produce high amounts of neutrophil extracellular traps (NETs). Surprisingly, this unique pathological program of neutrophil priming escaped conventional therapy with dexamethasone, thereby revealing a promising target for adjunctive immunotherapy in severe COVID-19.

Development of a Gill Perfusion Apparatus for Studying the Interaction of Fish Pathogens with Gill Tissue

2000 ◽  
Vol 28 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Annemie Decostere ◽  
James F. Turnbull ◽  
Richard Ducatelle ◽  
Freddy Haesebrouck
Keyword(s):  
Ex Vivo ◽  
Minimum Weight ◽  
Gill Tissue ◽  
Branchial Arch ◽  
Ringer Solution ◽  
Perfusion Fluid ◽  
Ex Vivo Model ◽  
Fish Pathogens ◽  
The Individual ◽  
Branchial Artery

An isolated perfused gill preparation was developed for the study of the association of gill pathogens with the branchial tissue. The preparation consisted of an excised branchial arch from common carp ( Cyprinus carpio L., minimum weight 300g), perfused via the afferent branchial artery. Filtered and heparinised Cortland solution was used as the perfusion fluid and infused by means of a drip (3-litre bag). The average perfusion rate was 1.5ml/minute/arch/kg body weight. The outflowing perfusate was collected from a cannula in the efferent branchial artery. The individual gill arch was suspended in a circular organ chamber filled with Ringer solution, which was aerated and kept at a constant temperature of 20°C. Unperfused gill arches maintained in Ringer solution at the same temperature served as controls. Cortland solution proved to be a satisfactory perfusion fluid, maintaining the perfused gills in a healthy condition for at least 4 hours with no, or only slight, oedema after 90 minutes, and slight or moderate oedema after 4 hours. The unperfused gill displayed excessive necrosis and loss of architecture after 4 hours. The Cortland perfused gill apparatus could thus prove to be an alternative ex vivo model of particular use in the study of the early interaction of gill associated pathogens with the branchial tissue.

scholarly journals Defective NaCl Reabsorption in Salivary Glands of Eda-Null X-LHED Mice

2018 ◽  
Vol 97 (11) ◽  
pp. 1244-1251 ◽  
Author(s):  
T. Mukaibo ◽  
T. Munemasa ◽  
C. Masaki ◽  
C.Y. Cui ◽  
J.E. Melvin
Keyword(s):  
Salivary Glands ◽  
Ectodermal Dysplasia ◽  
Ex Vivo ◽  
Quantitative Polymerase Chain Reaction ◽  
Fluid Secretion ◽  
Primary Objective ◽  
Wild Type ◽  
Human Form ◽  
Submandibular Glands ◽  
Major Salivary Glands

Mutations in the ectodysplasin A gene ( EDA) cause X-LHED (X-linked hypohidrotic ectodermal dysplasia), the most common human form of ectodermal dysplasia. Defective EDA signaling is linked to hypoplastic development of epithelial tissues, resulting in hypotrichosis, hypodontia, hypohidrosis, and xerostomia. The primary objective of the present study was to better understand the salivary gland dysfunction associated with ectodermal dysplasia using the analogous murine disorder. The salivary flow rate and ion composition of the 3 major salivary glands were determined in adult Eda-deficient Tabby hemizygous male (Ta/Y) and heterozygous female (Ta/X) mice. Submandibular and sublingual glands of Eda-mutant mice were smaller than wild-type littermates, while parotid gland weight was not significantly altered. Fluid secretion by the 3 major salivary glands was essentially unchanged, but the decrease in submandibular gland size was associated with a dramatic loss of ducts in Ta/Y and Ta/X mice. Reabsorption of Na+ and Cl–, previously linked in salivary glands to Scnn1 Na+ channels and Cftr Cl- channels, respectively, was markedly reduced at high flow rates in the ex vivo submandibular glands of Ta/Y mice (~60%) and, to a lesser extent, Ta/X mice (Na+ by 14%). Consistent with decreased Na+ reabsorption in Ta/Y mice, quantitative polymerase chain reaction analysis detected decreased mRNA expression for Scnn1b and Scnn1g, genes encoding the β and γ subunits, respectively. Moreover, the Na+ channel blocker amiloride significantly inhibited Na+ and Cl– reabsorption by wild-type male submandibular glands to levels comparable to those observed in Ta/Y mice. In summary, fluid secretion was intact in the salivary glands of Eda-deficient mice but displayed marked Na+ and Cl– reabsorption defects that correlated with the loss of duct cells and decreased Scnn1 Na+ channel expression. These results provide a likely mechanism for the elevated NaCl concentration observed in the saliva of affected male and female patients with X-LHED.

scholarly journals Ex Vivo and In Vitro Identification of a Consensus Promoter for VSG Genes Expressed by Metacyclic-Stage Trypanosomes in the Tsetse Fly

2002 ◽  
Vol 1 (6) ◽  
pp. 1000-1009 ◽  
Author(s):  
Michael L. Ginger ◽  
Patricia A. Blundell ◽  
Alyson M. Lewis ◽  
Alison Browitt ◽  
Arthur Günzl ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Ex Vivo ◽  
In Vitro Transcription ◽  
Tsetse Fly ◽  
Surface Glycoprotein ◽  
Start Site ◽  
Transcription Start ◽  
Transcription System ◽  
Rapid Amplification

ABSTRACT The trypanosome variant surface glycoprotein (VSG) is first expressed during differentiation to the infective, metacyclic population in tsetse fly salivary glands. Unlike the VSG genes expressed by bloodstream form trypanosomes, metacyclic VSGs (MVSGs) have their own promoters. The scarcity of metacyclic cells has meant that only indirect approaches have been used to study these promoters, and not even their identities have been agreed on. Here, we isolated trypanosomes by dissection from salivary glands and used an approach involving 5′ rapid amplification of cDNA ends to identify the transcription start site of three MVSGs. This shows that the authentic start site is that proposed for the MVAT series of MVSGs (K. S. Kim and J. E. Donelson, J. Biol. Chem. 272:24637-24645, 1997). In the more readily accessible procyclic trypanosome stage, where MVSGs are normally silent, we used reporter gene assays and linker scanning analysis to confirm that the 67 bp upstream of the start site is a promoter. This is confirmed further by accurate initiation in a homologous in vitro transcription system. We show also that MVSG promoters become derepressed when tested outwith their endogenous, subtelomeric loci. The MVSG promoters are only loosely conserved with bloodstream VSG promoters, and our detailed analysis of the 1.63 MVSG promoter reveals that its activity depends on the start site itself and sequences 26 to 49 bp and 56 to 60 bp upstream. These are longer than those necessary for the bloodstream promoter.

scholarly journals Viral Gene Transfer to Developing Mouse Salivary Glands

2011 ◽  
Vol 91 (2) ◽  
pp. 197-202 ◽  
Author(s):  
J.C. Hsu ◽  
G. Di Pasquale ◽  
J.S. Harunaga ◽  
T. Onodera ◽  
M.P. Hoffman ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Salivary Glands ◽  
High Efficiency ◽  
Ex Vivo ◽  
Mesenchymal Cell ◽  
Branching Morphogenesis ◽  
Viral Gene ◽  
Cell Type Specificity ◽  
Embryonic Mouse ◽  
Viral Gene Transfer

Branching morphogenesis is essential for the formation of salivary glands, kidneys, lungs, and many other organs during development, but the mechanisms underlying this process are not adequately understood. Microarray and other gene expression methods have been powerful approaches for identifying candidate genes that potentially regulate branching morphogenesis. However, functional validation of the proposed roles for these genes has been severely hampered by the absence of efficient techniques to genetically manipulate cells within embryonic organs. Using ex vivo cultured embryonic mouse submandibular glands (SMGs) as models to study branching morphogenesis, we have identified new vectors for viral gene transfer with high efficiency and cell-type specificity to developing SMGs. We screened adenovirus, lentivirus, and 11 types of adeno-associated viruses (AAV) for their ability to transduce embryonic day 12 or 13 SMGs. We identified two AAV types, AAV2 and bovine AAV (BAAV), that are selective in targeting expression differentially to SMG epithelial and mesenchymal cell populations, respectively. Transduction of SMG epithelia with self-complementary (sc) AAV2 expressing fibroblast growth factor 7 (Fgf7) supported gland survival and enhanced SMG branching morphogenesis. Our findings represent, to our knowledge, the first successful selective gene targeting to epithelial vs. mesenchymal cells in an organ undergoing branching morphogenesis.

Sign in / Sign up

Export Citation Format

Share Document