The Microvascular Organization of the Gas exchange Organs of the Australian Lungfish, Neoceratodus forsteri (Krefft)

1983 ◽  
Vol 31 (5) ◽  
pp. 651 ◽  
Author(s):  
BJ Gannon ◽  
DJ Randall ◽  
J Browing ◽  
RJG Lester ◽  
LJ Rogers
Keyword(s):  
Epithelial Cell ◽  
Corpus Cavernosum ◽  
Leading Edge ◽  
Ciliary Epithelium ◽  
Microvascular Network ◽  
Squamous Epithelial Cell ◽  
Pillar Cell ◽  
Secondary Lamellae ◽  
General Organization ◽  
Australian Lungfish

The general organization of the gill microvasculature of Neoceratodus is similar to that reported for elasmobranchs. A corpus cavernosum is situated between the afferent filamental artery and afferent lamellar arterioles. The microvascular network of the lamellar blood sheet consists of a series of major channels, curving in concentric arcs from afferent to efferent lamellar arterioles, with minor radial cross-connections between these major channels; the basal lamellar channels are not buried in the filament. The afferent filamental arteries also supply blood to the interbranchial septum, which extends almost to the filament tip. The water-blood barrier of 3-4 �m consists of up to three cells: the surface epithelial cell, the pillar cell flange. plus a frequently interposed interstitial cell; there is a prominent basal lamina immediately external to the pillar cell flange. Adjacent gill secondary lamellae are commonly fused at their free margins near the leading edge into groups of from two to five. The micro-organization of the pseudobranch is in general similar to that of the posterior holobranchs. The lung is divided into a series of air sacs by stout septae which contain large amounts of smooth muscle. The respiratory epithelium is of two types: a squamous epithelium underlain by a dense capillary sheet, and isolated patches of a columnar muco-ciliary epithelium associated with only few capillaries. The air-blood barrier (approximately 3 �m thick) consists of a squamous epithelial cell process and attenuated vesiculated endothelial cell cytoplasm, with two basal laminae and intervening interstitial space situated between these.

scholarly journals Morpho-Functional Alterations in the Gills of a Seawater Teleost, the Ornate Wrasse (Thalassoma pavo L.), after Short-Term Exposure to Chlorpyrifos

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Rachele Macirella ◽  
Vittoria Curcio ◽  
Elvira Brunelli
Keyword(s):  
Goblet Cells ◽  
High Concentration ◽  
Short Term ◽  
Cell Degeneration ◽  
Widespread Species ◽  
Pillar Cell ◽  
Secondary Lamellae ◽  
Short Term Exposure ◽  
First Time ◽  
Sublethal Concentrations

Chlorpyrifos (CPF) is an organophosphorus insecticide commonly used for domestic and agricultural purposes. The risk posed by environmental contamination from CPF is well acknowledged, and it has been detected worldwide in aquatic habitats and coastal areas. In addition, due to its slower degradation in seawater compared to freshwater, CPF is of particular concern for marine environments. Here, we investigated for the first time the morpho-functional alterations induced by CPF on the gills of Thalassoma pavo, a widespread species in the Mediterranean Sea. We tested the effects of two sublethal concentrations (4 and 8 µg/L) after 48 and 96 h. Our study demonstrates that the alterations induced by CPF are dose and time-dependent and highlight the harmful properties of this insecticide. After exposure to the low tested concentration, the more frequent alteration is an intense proliferation of the primary epithelium, whereas after exposure to the high concentration, the primary epithelium proliferation is less extensive, and the most evident effects are the thinning of secondary lamellae and the ectopia of chloride and goblet cells. CPF also modulated the expression of Na+/K+-ATPase. Dilation of lamellar apical tips, pillar cell degeneration, and appearance of aneurysms are often observed.

scholarly journals Autotaxin induces lung epithelial cell migration through lysoPLD activity-dependent and -independent pathways

2011 ◽  
Vol 439 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Jing Zhao ◽  
Donghong He ◽  
Evgeny Berdyshev ◽  
Mintao Zhong ◽  
Ravi Salgia ◽  
...  
Keyword(s):  
Cell Migration ◽  
Epithelial Cell ◽  
Cell Surface ◽  
Leading Edge ◽  
Lung Epithelial Cell ◽  
Intratracheal Administration ◽  
Lpa Receptor ◽  
Epithelial Cell Migration ◽  
Lung Epithelial ◽  
Integrin Β4

Lung cell migration is a crucial step for re-epithelialization that in turn is essential for remodelling and repair after lung injury. In the present paper we hypothesize that secreted ATX (autotaxin), which exhibits lysoPLD (lysophospholipase D) activity, stimulates lung epithelial cell migration through LPA (lysophosphatidic acid) generation-dependent and -independent pathways. Release of endogenous ATX protein and activity was detected in lung epithelial cell culture medium. ATX with V5 tag overexpressed conditional medium had higher LPA levels compared with control medium and stimulated cell migration through Gαi-coupled LPA receptors, cytoskeleton rearrangement, phosphorylation of PKC (protein kinase C) δ and cortactin at the leading edge of migrating cells. Inhibition of PKCδ attenuated ATX–V5 overexpressed conditional medium-mediated phosphorylation of cortactin. In addition, a recombinant ATX mutant, lacking lysoPLD activity, or heat-inactived ATX also induced lung epithelial cell migration. Extracelluar ATX bound to the LPA receptor and integrin β4 complex on A549 cell surface. Finally, intratracheal administration of LPS (lipopolysaccharide) into the mouse airway induced ATX release and LPA production in BAL (bronchoalveolar lavage) fluid. These results suggested a significant role for ATX in lung epithelial cell migration and remodelling through its ability to induce LPA production-mediated phosphorylation of PKCδ and cortactin. In addition we also demonstrated assocation of ATX with the epithelial cell-surface LPA receptor and integrin β4.

scholarly journals Nasal Colonisation by Staphylococcus aureus Depends upon Clumping Factor B Binding to the Squamous Epithelial Cell Envelope Protein Loricrin

2012 ◽  
Vol 8 (12) ◽  
pp. e1003092 ◽  
Author(s):  
Michelle E. Mulcahy ◽  
Joan A. Geoghegan ◽  
Ian R. Monk ◽  
Kate M. O'Keeffe ◽  
Evelyn J. Walsh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Epithelial Cell ◽  
Envelope Protein ◽  
Cell Envelope ◽  
Factor B ◽  
Squamous Epithelial Cell ◽  
Clumping Factor B

scholarly journals Force-Induced Strengthening of the Interaction between Staphylococcus aureus Clumping Factor B and Loricrin

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Pauline Vitry ◽  
Claire Valotteau ◽  
Cécile Feuillie ◽  
Simon Bernard ◽  
David Alsteens ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Epithelial Cell ◽  
Envelope Protein ◽  
Cell Envelope ◽  
Surface Protein ◽  
Binding Mechanism ◽  
Factor B ◽  
Squamous Epithelial Cell ◽  
High Affinity ◽  
Clumping Factor B

ABSTRACT Bacterial pathogens that colonize host surfaces are subjected to physical stresses such as fluid flow and cell surface contacts. How bacteria respond to such mechanical cues is an important yet poorly understood issue. Staphylococcus aureus uses a repertoire of surface proteins to resist shear stress during the colonization of host tissues, but whether their adhesive functions can be modulated by physical forces is not known. Here, we show that the interaction of S. aureus clumping factor B (ClfB) with the squamous epithelial cell envelope protein loricrin is enhanced by mechanical force. We find that ClfB mediates S. aureus adhesion to loricrin through weak and strong molecular interactions both in a laboratory strain and in a clinical isolate. Strong forces (~1,500 pN), among the strongest measured for a receptor-ligand bond, are consistent with a high-affinity “dock, lock, and latch” binding mechanism involving dynamic conformational changes in the adhesin. Notably, we demonstrate that the strength of the ClfB-loricrin bond increases as mechanical force is applied. These findings favor a two-state model whereby bacterial adhesion to loricrin is enhanced through force-induced conformational changes in the ClfB molecule, from a weakly binding folded state to a strongly binding extended state. This force-sensitive mechanism may provide S. aureus with a means to finely tune its adhesive properties during the colonization of host surfaces, helping cells to attach firmly under high shear stress and to detach and spread under low shear stress. IMPORTANCE Staphylococcus aureus colonizes the human skin and the nose and can cause various disorders, including superficial skin lesions and invasive infections. During nasal colonization, the S. aureus surface protein clumping factor B (ClfB) binds to the squamous epithelial cell envelope protein loricrin, but the molecular interactions involved are poorly understood. Here, we unravel the molecular mechanism guiding the ClfB-loricrin interaction. We show that the ClfB-loricrin bond is remarkably strong, consistent with a high-affinity “dock, lock, and latch” binding mechanism. We discover that the ClfB-loricrin interaction is enhanced under tensile loading, thus providing evidence that the function of an S. aureus surface protein can be activated by physical stress. IMPORTANCE Staphylococcus aureus colonizes the human skin and the nose and can cause various disorders, including superficial skin lesions and invasive infections. During nasal colonization, the S. aureus surface protein clumping factor B (ClfB) binds to the squamous epithelial cell envelope protein loricrin, but the molecular interactions involved are poorly understood. Here, we unravel the molecular mechanism guiding the ClfB-loricrin interaction. We show that the ClfB-loricrin bond is remarkably strong, consistent with a high-affinity “dock, lock, and latch” binding mechanism. We discover that the ClfB-loricrin interaction is enhanced under tensile loading, thus providing evidence that the function of an S. aureus surface protein can be activated by physical stress.

scholarly journals Cellular events and behaviors after grafting of stratified squamous epithelial cell sheet onto a hydrated collagen gel

FEBS Open Bio ◽  
2017 ◽  
Vol 7 (5) ◽  
pp. 691-704 ◽  
Author(s):  
Yoshiyuki Kasai ◽  
Naoya Takeda ◽  
Shinichiro Kobayashi ◽  
Ryo Takagi ◽  
Masayuki Yamato
Keyword(s):  
Epithelial Cell ◽  
Cell Sheet ◽  
Collagen Gel ◽  
Squamous Epithelial Cell ◽  
Cellular Events ◽  
And Behaviors ◽  
Hydrated Collagen Gel

Induction of maxillary and mandibular squamous epithelial cell proliferation in mink ( Neovison vison ) by β‐naphthoflavone

2019 ◽  
Vol 38 (2) ◽  
pp. 460-463
Author(s):  
Danielle K. Matz ◽  
Joanna Chuck ◽  
Robin J. Hosmer ◽  
Hannah C. Piper ◽  
Jane E. Link ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Neovison Vison ◽  
Epithelial Cell Proliferation ◽  
Squamous Epithelial Cell
Sign in / Sign up

Export Citation Format

Share Document