Goblet cell membrane differentiations in the midgut of a lepidopteran larva

1976 ◽  
Vol 20 (2) ◽  
pp. 357-375
Author(s):  
N.E. Flower ◽  
B.K. Filshie
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Active Transport ◽  
Goblet Cell ◽  
Goblet Cells ◽  
Wide Channel ◽  
Lepidopteran Larvae ◽  
Lanthanum Tracer ◽  
Cell Cavity

So-called goblet cells are present in the midgut of lepidopteran larvae. They are thought to be involved in the active transport of potassium out of the haemolymph and into the gut lumen. A number of plasma membrane differentiations within the goblet cell cavity has been investigated using conventional staining, lanthanum tracer and freeze-etch techniques. Of particular interest are junction-like inter- and intra-membrane differentiations found on the villus-like cytoplasmic projections present at the apical tip of the goblet cell cavities. These cytoplasmic projections appear to act as a valve; in some cases they seem to close off the top of the goblet cell cavity, so isolating it from the gut lumen, while in other cases they are spread apart leaving a wide channel from the cavity into the lumen. The junction-like structures on these cytoplasmic projections are different in structure from the septate-type junctions which seal the midgut cells together at their apical borders, and the 2 types are present on the same plasma membrane, often within one micron of each other. The need for a different type of junction may possibly be related to the fact that it occurs between 2 areas of the same plasma membrane. The morphology of this unusual junction-like structure is discussed and 2 diagrams are presented to illustrate our interpretation of its structure.

Cytoskeleton of intestinal goblet cells: role of actin filaments in baseline secretion

1990 ◽  
Vol 259 (6) ◽  
pp. G991-G997 ◽  
Author(s):  
M. G. Oliver ◽  
R. D. Specian
Keyword(s):  
Plasma Membrane ◽  
Goblet Cell ◽  
Actin Filaments ◽  
Cellular Response ◽  
Apical Cell ◽  
Goblet Cells ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
Cytochemical Localization

Although microtubules appear necessary to maintain mucin granule transport in intestinal goblet cells, the role of microfilaments in mucus secretion is unknown. To determine the functional significance of microfilaments in goblet cell secretion, fluorescent cytochemistry of microfilaments and autoradiographic studies on granule movement were performed on rabbit intestinal goblet cells, with and without the actin depolymerizing agents, cytochalasin D (cyto D), and dihydro-cytochalasin B (dihydro B). In normal goblet cells, cytochemical localization of F-actin with NBD-phallacidin demonstrated their restriction to the apical surface of the goblet cell. Visualization of the goblet cell apical surface by electron microscopy revealed the presence of a thin layer of cytoplasm overlying the granule mass. Treatment with cyto D and dihydro B eliminated NBD-phallacidin staining of the apical cell surface. Quantitative analysis of baseline granule translocation demonstrated that treatment with cyto D and dihydro B resulted in dramatic acceleration of granule movement through goblet cells. This cellular response results from an increase in baseline secretion and facilitation of secretion of newly synthesized mucins, not stimulation of an accelerated secretory event. These data imply that actin filaments fulfill a barrier function in baseline secretion by hindering granule access to the plasma membrane; once the granule contacts the plasma membrane, exocytosis occurs. Secretion is balanced by the translocation of subjacent granules. In contrast, an accelerated secretory event is not triggered by plasma membrane access alone; this event requires a regulatory signal. We hypothesize that, unlike accelerated secretion, baseline secretion is constitutive, with exocytosis limited solely by the physical constraint of secretory granule access to the apical plasma membrane.

scholarly journals ACTIVE TRANSPORT BY THE CECROPIA MIDGUT

1966 ◽  
Vol 31 (1) ◽  
pp. 107-134 ◽  
Author(s):  
Everett Anderson ◽  
William R. Harvey
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Goblet Cell ◽  
Plasma Membranes ◽  
Goblet Cells ◽  
Potassium Transport ◽  
Columnar Cell ◽  
Morphological Data ◽  
Basal Region ◽  
Cytoplasmic Matrix

A morphological basis for transcellular potassium transport in the midgut of the mature fifth instar larvae of Hyalophora cecropia has been established through studies with the light and electron microscopes. The single-layered epithelium consists of two distinct cell types, the columnar cell and the goblet cell. No regenerative cells are present. Both columnar and goblet cells rest on a well developed basement lamina. The basal portion of the columnar cell is incompletely divided into compartments by deep infoldings of the plasma membrane, whereas the apical end consists of numerous cytoplasmic projections, each of which is covered with a fine fuzzy or filamentous material. The cytoplasm of this cell contains large amounts of rough endoplasmic reticulum, microtubules, and mitochondria. In the basal region of the cell the mitochondria are oriented parallel to the long axes of the folded plasma-lemma, but in the intermediate and apical portions they are randomly scattered within the cytoplasmic matrix. Compared to the columnar cell, the goblet cell has relatively little endoplasmic reticulum. On the other hand, the plications of the plasma membrane of the goblet cell greatly exceed those of the columnar cell. One can distinguish at least four characteristic types of folding: (a) basal podocytelike extensions, (b) lateral evaginations, (c) apical microvilli, and (d) specialized cytoplasmic projections which line the goblet chamber. Apically, the projections are large and branch to form villus-like units, whereas in the major portion of the cavity each projection appears to contain an elongate mitochondrion. Junctional complexes of similar kind and position appear between neighboring columnar cells and between adjacent columnar and goblet cells as follows: a zonula adherens is found near the luminal surface and is followed by one or more zonulae occludentes. The morphological data obtained in this study and the physiological information on ion transport through the midgut epithelium have encouraged us to suggest that the goblet cell may be the principal unit of active potassium transport from the hemolymph to the lumen of the midgut. We have postulated that ion accumulation by mitochondria in close association with plicated plasma membranes may play a role in the active movement of potassium across the midgut.

scholarly journals A50 MODULATION OF GOBLET CELL ACTIVITY DURING GIARDIA DUODENALIS INFECTION: A ROLE FOR PAR2

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 6-7
Author(s):  
E Fekete ◽  
C B Amat ◽  
T Allain ◽  
M Hollenberg ◽  
K Mihara ◽  
...  
Keyword(s):  
Gene Expression ◽  
Goblet Cell ◽  
Cysteine Protease ◽  
Protease Activity ◽  
Calcium Release ◽  
Cell Activity ◽  
Goblet Cells ◽  
Giardia Infection ◽  
Mucus Production ◽  
Mucin Gene

Abstract Background Giardia duodenalis has been shown to alter the structure of the intestinal mucus layers during infection via obscure mechanisms. We hypothesize that goblet cell activity may be disrupted in part due to proteolytic activation of protease-activated receptor 2 (PAR2) by Giardia proteases, resulting in disruption of mucus production and secretion by intestinal goblet cells. Aims Characterize alterations in goblet cell activity during Giardia infection, focusing on the roles of Giardia protease activity and PAR2. Methods Chinese hamster ovary cells transfected with nano-luciferase tagged PAR2 were incubated with Giardia NF or GSM trophozoites. Cleavage within the activation domain results in release of enzymes into the supernatant. Luminescence in the supernatant was measured as an indication of PAR cleavage by Giardia. LS174T, a human colonic mucus-producing cell line, was infected with Giardia trophozoites (isolates NF, WB, S2, and GSM). Prior to infection, trophozoites were treated with E64, a broad-spectrum cysteine protease inhibitor, and LS174T were treated with a PAR2 antagonist, a calcium chelator, or an ERK1/2 inhibitor. Quantitative PCR (qPCR) was performed for the MUC2 mucin gene. Wild-type (WT) and PAR2 knockout (KO) mice were infected with Giardia. Colonic mucus was stained using fluorescein-coupled wheat-germ agglutinin (WGA), and qPCR was performed for Muc2 and Muc5ac. Results Giardia trophozoites cleaved PAR2 within the N-terminal activation domain in a cysteine protease-dependent manner. Cleavage was isolate dependent, with isolates that show higher protease activity cleaving at a higher rate. High protease activity Giardia isolates increased MUC2 gene expression in LS714T. This increase was attenuated by inhibition of Giardia cysteine protease activity, and by antagonism of PAR2, inhibition of calcium release, or inhibition of ERK1/2 activity in LS174T cells. Both Muc2 and Muc5ac expression were upregulated in the colons of WT mice in response to Giardia infection, while in the jejunum Muc2 expression decreased and Muc5ac expression increased. In KO, no changes in gene expression were seen in the colon in response to Giardia infection, while in the jejunum, Muc2 expression was unchanged and Muc5ac expression decreased. Both WT infected and KO noninfected mice showed thinning of the colonic mucus layer compared to WT controls. There was some recovery in thickness in KO infected mice. Conclusions PAR2 plays a significant role in the regulation of mucin gene expression in mice and in a human colonic cell line. Results suggest that Giardia cysteine proteases cleave and activate PAR2, leading to calcium release and activation of the MAPK pathway in goblet cells, ultimately leading to altered mucin gene expression. Findings identify a novel regulatory pathway for mucus production by intestinal goblet cells. Funding Agencies CAG, CCC

scholarly journals Molecular cloning of mouse intestinal trefoil factor and its expression during goblet cell changes

1995 ◽  
Vol 311 (1) ◽  
pp. 293-297 ◽  
Author(s):  
M Tomita ◽  
H Itoh ◽  
N Ishikawa ◽  
A Higa ◽  
H Ide ◽  
...  
Keyword(s):  
Goblet Cell ◽  
Goblet Cells ◽  
Recovery Phase ◽  
Nippostrongylus Brasiliensis ◽  
Trefoil Factor ◽  
Intestinal Trefoil Factor ◽  
Cell Hyperplasia ◽  
Reverse Transcription Pcr ◽  
Rapid Amplification ◽  
Mitf Expression

A cDNA encoding mouse intestinal trefoil factor (mITF) was successfully cloned and sequenced from the small intestine of C57BL/6 mouse by using the combination of reverse transcription-PCR and rapid amplification of cDNA ends methods. The gene was, similar to rat and human ITFs, mainly expressed in the small and large intestine. The mITF expression was up-regulated during the recovery phase after depletion of goblet cells in acetic acid-induced colitis. On the other hand, the expression in the jejunum was not altered, while goblet cell hyperplasia was induced by Nippostrongylus brasiliensis infection. These results suggest that the mITF expression did not simply correlate with the number of goblet cells. The mITF may play an important role in the maintenance and repair of mucosal function of the rectum. Additionally, the mITF in the jejunum may play a role in alteration of the physicochemical nature of goblet cell mucins, thereby affecting the establishment of intestinal helminths.

Barrier role of actin filaments in regulated mucin secretion from airway goblet cells

2005 ◽  
Vol 288 (1) ◽  
pp. C46-C56 ◽  
Author(s):  
Camille Ehre ◽  
Andrea H. Rossi ◽  
Lubna H. Abdullah ◽  
Kathleen De Pestel ◽  
Sandra Hill ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Actin Filaments ◽  
Fluorescent Protein ◽  
Secretory Granules ◽  
Yellow Fluorescent Protein ◽  
Goblet Cells ◽  
Actin Binding ◽  
Secretory Cells ◽  
Cortical Actin ◽  
Mucin Secretion

Airway goblet cells secrete mucin onto mucosal surfaces under the regulation of an apical, phospholipase C/Gq-coupled P2Y2receptor. We tested whether cortical actin filaments negatively regulate exocytosis in goblet cells by forming a barrier between secretory granules and plasma membrane docking sites as postulated for other secretory cells. Immunostaining of human lung tissues and SPOC1 cells (an epithelial, mucin-secreting cell line) revealed an apical distribution of β- and γ-actin in ciliated and goblet cells. In goblet cells, actin appeared as a prominent subplasmalemmal sheet lying between granules and the apical membrane, and it disappeared from SPOC1 cells activated by purinergic agonist. Disruption of actin filaments with latrunculin A stimulated SPOC1 cell mucin secretion under basal and agonist-activated conditions, whereas stabilization with jasplakinolide or overexpression of β- or γ-actin conjugated to yellow fluorescent protein (YFP) inhibited secretion. Myristoylated alanine-rich C kinase substrate, a PKC-activated actin-plasma membrane tethering protein, was phosphorylated after agonist stimulation, suggesting a translocation to the cytosol. Scinderin (or adseverin), a Ca2+-activated actin filament severing and capping protein was cloned from human airway and SPOC1 cells, and synthetic peptides corresponding to its actin-binding domains inhibited mucin secretion. We conclude that actin filaments negatively regulate mucin secretion basally in airway goblet cells and are dynamically remodeled in agonist-stimulated cells to promote exocytosis.

Membrane changes associated with mucus production by intestinal goblet cells

1978 ◽  
Vol 33 (1) ◽  
pp. 301-316
Author(s):  
J.G. Swift ◽  
T.M. Mukherjee
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Fusion ◽  
Thin Section ◽  
Structural Organization ◽  
Freeze Fracture ◽  
Goblet Cells ◽  
Mucus Production ◽  
Membrane Reorganization ◽  
Membrane Changes

Changes in the structural organization of membranes of mucous bodies and the plasma membrane that occur during mucus production in goblet cells of rat rectum have been studied by thin-section and freeze-fracture techniques. Immature mucous bodies are bounded by a trilaminar membrane and fracture faces of the membrane have randomly distributed intramembrane particles. During maturation, mucous bodies become packed tightly together and changes in the structure of their membranes include (1) fusion of apposing membranes of adjacent bodies to form a pentalaminar structure, (2) a reduction in the density of particles on membrane fracture faces, and (3) exclusion of particles from regions of membrane apposition. Some trilaminar membranes of mucous bodies fuse with the lumenal plasma membrane to form a pentalaminar structure. Sites of apposition between mucous body membranes and the lumenal plasma membrane are seen as particle-cleared bulges on fracture faces of the plasma membrane. Our results indicate that membrane reorganization associated with mucous production in goblet cells includes a reduction and redistribution of some membrane proteins and that membrane fusion occurs between portions of membranes from which proteins have been displaced.

scholarly journals Tear Ferning Test and Pathological Effects on Ocular Surface before and after Topical Cyclosporine in Vernal Keratoconjunctivitis Patients

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Marcella Nebbioso ◽  
Marta Sacchetti ◽  
Guia Bianchi ◽  
Anna Maria Zicari ◽  
Marzia Duse ◽  
...  
Keyword(s):  
Cell Density ◽  
Goblet Cell ◽  
Ocular Surface ◽  
Goblet Cells ◽  
Significant Alteration ◽  
Vernal Keratoconjunctivitis ◽  
Eye Drops ◽  
Before And After ◽  
Tear Ferning Test ◽  
Goblet Cell Density

Background. Vernal keratoconjunctivitis (VKC) is a rare ocular surface inflammatory disease that affects mainly boys in the first decade of life. Clinical observations show that it generally regresses spontaneously with the onset of puberty, but therapeutic measures must be taken before then to control the course of the disease. Purpose.To evaluate the role of the lacrimal mucous component in VKC patients and compare tear ferning test (TFT) modifications, MUC5AC levels in tears, and density of conjunctival goblet cells to clinical characteristics before and after treatment with cyclosporine A (CY) in eye drops. Methods. Forty-seven patients affected by VKC and 30 healthy subjects aged between 3 and 16 years of life were enrolled. All individuals were submitted to complete eye examination and skin prick test (SPT) for the most common allergens. Then, they were subjected to collection of the tears and to impression cytology to evaluate TFT, MUC5AC levels, and conjunctival goblet cell density, before and after treatment with CY in eye drops. Results. Comparing the VKC group vs. the control group at baseline, a significant alteration in the degree of the ferns was found, indicating a pathological condition of the lacrimal mucous layer. In addition, an increased number of goblet cells were observed in the patients. The concentration of lacrimal secretory mucins (MUC5AC) did not show significant differences between the 2 groups. Patients treated with CY have reported improvements of some signs and symptoms of disease activity, including TFT, and a tendency of conjunctival goblet cell density to normalise. Conclusions. The results obtained demonstrated for the first time a significant alteration of the lacrimal mucin component evaluated in the VKC group, and an improvement of the latter after CY therapy.

Time-Course of Changes in the Plasma–Membrane Lipid Bilayer and Cellular Ultrastructure Induced by Tumour Necrosis Factor-α in K 562 and Daudi Cells

1995 ◽  
Vol 23 (4) ◽  
pp. 254-263 ◽  
Author(s):  
M Marutaka ◽  
H Iwagaki ◽  
K Mizukawa ◽  
N Tanaka ◽  
K Orita
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Fluidity ◽  
Time Course ◽  
Membrane Lipid ◽  
Plasma Membrane Lipid ◽  
Membrane Lipid Bilayer ◽  
Cell Membrane Fluidity ◽  
K 562 Cells ◽  
Factor Α

The time-course of changes in the plasma-membrane lipid bilayer induced by tumour necrosis factor-α (TNF) were investigated in cultured cells using spin-label electron-spin-resonance techniques. Treatment of K 562 cells, a human chronic myelocytic leukaemia cell line, in suspension culture with TNF for up to 6 h caused an initial increase in cell-membrane fluidity, which returned to the control level after 12 h of treatment. After 24 h of treatment, the cell-membrane fluidity had decreased and this decrease was maintained after 48 h of treatment. In Daudi cells, a human malignant lymphoma cell line, TNF, did not induce any changes in cell-membrane fluidity, indicating that the effect of TNF on membrane structure is cell-specific. The early and transient change in membrane fluidity in K 562 cells is probably related to signal generation, while the later, persistent change may reflect the phenotype of TNF-treated cells, in particular, changes in the plasma membrane-cytoplasmic complex. Histochemical electron microscopic studies indicated that the membrane fluidity changes induced by TNF have an ultrastructural correlate.

scholarly journals Comparative Roles of the Cell Wall and Cell Membrane in Limiting Uptake of Xenobiotic Molecules by Saccharomyces cerevisiae

2003 ◽  
Vol 47 (6) ◽  
pp. 2012-2014 ◽  
Author(s):  
Mustapha Aouida ◽  
Omar Tounekti ◽  
Omrane Belhadj ◽  
Lluis M. Mir
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Protein

ABSTRACT Using reversible electropermeabilization of cells and spheroplasts, we show that the cell wall and plasma membrane partly account for bleomycin resistance by acting as two independent barriers. We also report on the presence of a membrane protein that may be responsible for bleomycin internalization and toxicity in Saccharomyces cerevisiae.

scholarly journals Cation-chloride cotransporters, Na/K pump, and channels in cell water and ions regulation: in silico and experimental studies of the U937 cells under stopping the pump and during RVD

2021 ◽  
Author(s):  
Alexey A Vereninov ◽  
Valentina Yurinskaya
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Real Time ◽  
Intracellular Signaling ◽  
Ion Homeostasis ◽  
Regulatory Volume Decrease ◽  
Experimental Studies ◽  
U937 Cells ◽  
Ionic Homeostasis ◽  
Monovalent Ions

Cation-coupled chloride cotransporters play a key role in generating the Cl− electrochemical gradient on the cell membrane which is important for regulation of many cellular processes. However, the cooperation of transporters and channels of the plasma membrane in holding the ionic homeostasis of the whole cell remains poorly characterized because of the lack of a suitable tool for its computation. Our software successfully predicted in real-time changes in the ion homeostasis of U937 cells after stopping the Na/K pump, but so far considered the model with only NC cotransporter. Here the model with all main types of cotransporters is used in computation of the rearrangements of ionic homeostasis due to stopping the pump and associated with the regulatory volume decrease (RVD) of cells swollen in hypoosmolar medium. The parameters obtained for the real U937 cells are used. Successful prediction of changes in ion homeostasis in real-time after stopping the pump using the model with all major cotransporters indicates that the model is reliable. Using this model for analysis RVD showed that there is a "physical" RVD, associated with the time-dependent changes in electrochemical ion gradients, but not with alteration of channels and transporters of the plasma membrane that should be considered in studies of truly active regulatory processes mediated by the intracellular signaling network. The developed software can be useful for calculation of the balance of the partial unidirectional fluxes of monovalent ions across the cell membrane of various cells under various conditions.

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