Epithelial distribution of neural receptors in the guinea pig small intestine

2005 ◽  
Vol 83 (5) ◽  
pp. 389-395 ◽  
Author(s):  
Carolyn J Baglole ◽  
Joseph S Davison ◽  
Jonathan B Meddings
Keyword(s):  
Epithelial Cells ◽  
Guinea Pig ◽  
Adrenergic Receptors ◽  
Cellular Localization ◽  
Specific Binding ◽  
Cell Types ◽  
Intraepithelial Lymphocytes ◽  
Histamine Receptors ◽  
Intestinal Epithelial ◽  
Β Adrenergic Receptors

Neural and paracrine agents, such as dopamine, epinephrine, and histamine, affect intestinal epithelial function, but it is unclear if these agents act on receptors directly at the enterocyte level. The cellular localization and villus-crypt distribution of adrenergic, dopamine, and histamine receptors within the intestinal epithelium is obscure and needs to be identified. Single cell populations of villus or crypt epithelial cells were isolated from the jejunum of adult guinea pigs. Enterocytes were separated from intraepithelial lymphocytes by flow cytometry and specific binding was determined using fluorescent probes. α1-adrenergic receptors were located on villus and crypt intraepithelial lymphocytes and enterocytes. β-adrenergic receptors were found on villus and crypt enterocytes. Dopamine receptors were found on all cell types examined, whereas histamine receptors were not detected (<10% for each cell population). These studies demonstrated that (1) receptors for epinephrine and dopamine exist on epithelial cells of the guinea pig jejunum, (2) β-adrenergic receptors are found primarily on villus and crypt enterocytes and (3) intraepithelial lymphocytes contain α1-adrenergic, but have few β-adrenergic, receptors. The presence of neural receptors suggests that these agents are acting, at least in part, at the enterocyte or intraepithelial lymphocyte levels to modulate intestinal and immune function.Key words: enterocyte, receptor, intestine, epithelium.

scholarly journals RNA regulons are essential in intestinal homeostasis

2019 ◽  
Vol 316 (1) ◽  
pp. G197-G204 ◽  
Author(s):  
Louis R. Parham ◽  
Patrick A. Williams ◽  
Priya Chatterji ◽  
Kelly A. Whelan ◽  
Kathryn E. Hamilton
Keyword(s):  
Epithelial Cells ◽  
Rna Binding ◽  
Environmental Changes ◽  
Cell Function ◽  
Rna Binding Proteins ◽  
Cell Types ◽  
Intestinal Epithelial ◽  
Cell Dynamics ◽  
Functional Roles ◽  
Proliferating Cell

Intestinal epithelial cells are among the most rapidly proliferating cell types in the human body. There are several different subtypes of epithelial cells, each with unique functional roles in responding to the ever-changing environment. The epithelium’s ability for rapid and customized responses to environmental changes requires multitiered levels of gene regulation. An emerging paradigm in gastrointestinal epithelial cells is the regulation of functionally related mRNA families, or regulons, via RNA-binding proteins (RBPs). RBPs represent a rapid and efficient mechanism to regulate gene expression and cell function. In this review, we will provide an overview of intestinal epithelial RBPs and how they contribute specifically to intestinal epithelial stem cell dynamics. In addition, we will highlight key gaps in knowledge in the global understanding of RBPs in gastrointestinal physiology as an opportunity for future studies.

scholarly journals Agonist binding to β-adrenergic receptors on human airway epithelial cells inhibits migration and wound repair

2015 ◽  
Vol 309 (12) ◽  
pp. C847-C855 ◽  
Author(s):  
Elizabeth R. Peitzman ◽  
Nathan A. Zaidman ◽  
Peter J. Maniak ◽  
Scott M. O'Grady
Keyword(s):  
Epithelial Cells ◽  
Protein Phosphatase ◽  
Adrenergic Receptors ◽  
Wound Repair ◽  
Wound Closure ◽  
Basal Membrane ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Phosphatase 2A ◽  
Β Adrenergic Receptors

Human airway epithelial cells express β-adrenergic receptors (β-ARs), which regulate mucociliary clearance by stimulating transepithelial anion transport and ciliary beat frequency. Previous studies using airway epithelial cells showed that stimulation with isoproterenol increased cell migration and wound repair by a cAMP-dependent mechanism. In the present study, impedance-sensing arrays were used to measure cell migration and epithelial restitution following wounding of confluent normal human bronchial epithelial (NHBE) and Calu-3 cells by electroporation. Stimulation with epinephrine or the β2-AR-selective agonist salbutamol significantly delayed wound closure and reduced the mean surface area of lamellipodia protruding into the wound. Treatment with the β-AR bias agonist carvedilol or isoetharine also produced a delay in epithelial restitution similar in magnitude to epinephrine and salbutamol. Measurements of extracellular signal-regulated kinase phosphorylation following salbutamol or carvedilol stimulation showed no significant change in the level of phosphorylation compared with untreated control cells. However, inhibition of protein phosphatase 2A activity completely blocked the delay in wound closure produced by β-AR agonists. In Calu-3 cells, where CFTR expression was inhibited by RNAi, salbutamol did not inhibit wound repair, suggesting that β-AR agonist stimulation and loss of CFTR function share a common pathway leading to inhibition of epithelial repair. Confocal images of the basal membrane of Calu-3 cells labeled with anti-β1-integrin (clone HUTS-4) antibody showed that treatment with epinephrine or carvedilol reduced the level of activated integrin in the membrane. These findings suggest that treatment with β-AR agonists delays airway epithelial repair by a G protein- and cAMP-independent mechanism involving protein phosphatase 2A and a reduction in β1-integrin activation in the basal membrane.

scholarly journals Adrenergic and Cholinergic Receptors of Cerebral Microvessels

1981 ◽  
Vol 1 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Sami I. Harik ◽  
Virendra K. Sharma ◽  
John R. Wetherbee ◽  
Robert H. Warren ◽  
Shailesh P. Banerjee
Keyword(s):  
Adrenergic Receptors ◽  
Specific Binding ◽  
Cholinergic Receptors ◽  
Biologically Active ◽  
Adrenergic Agonists ◽  
Muscarinic Cholinergic Receptors ◽  
Cerebral Microvessels ◽  
Binding Characteristics ◽  
Muscarinic Cholinergic ◽  
Β Adrenergic Receptors

The presence of α- and β-adrenergic and muscarinic cholinergic receptors in cerebral microvessels of the rat and pig was assessed by ligand binding techniques. The results demonstrate the presence of specific binding to α2- and β-adrenergic receptors but no appreciable specific binding to α1-adrenergic or muscarinic cholinergic receptors. β-Adrenergic receptors of pig cerebral microvessels are similar to those of the brain and other organs in their binding characteristics to the tritiated ligand and in their stereospecificity of binding to the biologically active isomers of β-adrenergic agonists. Further evidence derived from the differential potency of binding displacement by the various β-adrenergic agonists and selective β1- and β2-adrenergic antagonists indicates that β-adrenergic receptors of pig cerebral microvessels are mostly of the β2-subtype.

scholarly journals The Dual Tropism of Noroviruses

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Christiane E. Wobus
Keyword(s):  
Epithelial Cells ◽  
Rna Viruses ◽  
Intestinal Epithelial Cells ◽  
Mammalian Species ◽  
Cell Types ◽  
Economic Losses ◽  
Cell Tropism ◽  
Intestinal Epithelial ◽  
Complex Cell ◽  
Significant Morbidity

ABSTRACTNoroviruses are highly prevalent enteric RNA viruses. Human noroviruses (HuNoVs) cause significant morbidity, mortality, and economic losses worldwide. Infections also occur in other mammalian species, including mice. Despite the discovery of the first norovirus in 1972, the viral tropism has long remained an enigma. A long-held assumption was that these viruses infect intestinal epithelial cells. Recent data support a more complex cell tropism of epithelial and nonepithelial cell types.

Epithelial localization of a reptilian Na+/H+ exchanger homologous to NHE-1

1997 ◽  
Vol 272 (6) ◽  
pp. G1594-G1606 ◽  
Author(s):  
S. P. Harris ◽  
T. V. Strong ◽  
N. Wys ◽  
N. W. Richards ◽  
J. Pouyssegur ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cellular Localization ◽  
Cell Types ◽  
Transport Processes ◽  
Transepithelial Transport ◽  
Immunofluorescent Localization ◽  
Basolateral Membranes ◽  
Partial Length ◽  
High Level ◽  
Exchange Activity

Basolateral membranes of turtle (Pseudemys scripta) colon epithelial cells exhibit robust Na+/H+ exchange activity that can be activated by cell shrinkage and is blocked by amiloride [M. A. Post and D. C. Dawson. Am. J. Physiol. 262 Cell Physiol. 31):C1089-C1094, 1992]. The colonic epithelium actively absorbs Na+ and secretes K+ and HCO3-, but the role of basolateral Na+/H+ exchange, if any, in transepithelial transport is unknown. The current studies were undertaken to identify the gene product(s) responsible for the observed basolateral Na+/H+ exchange activity and to determine the cellular localization of the reptilian Na+/H+ exchange protein. We cloned and sequenced partial-length cDNAs that are likely to encode a reptilian homologue of the mammalian NHE-1 Na+/H+ exchanger isoform. The partial-length cDNAs were > 80% identical to mammalian NHE-1 homologues at the nucleotide level and recognized a transcript (approximately 5.8-6.0 kb) in RNA isolated from turtle colon, small intestine, stomach, kidney, urinary bladder, heart, and liver. In situ hybridization showed that mRNA encoding the reptile homologue of NHE-1 was expressed predominantly in the epithelial cells of these tissues. Immunofluorescent localization of the reptilian Na+/H+ exchanger protein using an antibody raised against a human NHE-1 fusion protein confirmed that protein expression paralleled abundant mRNA expression in epithelial cells of turtle stomach and colon, as well as in some nephron segments, and showed that the reptile NHE-1 homologue was localized exclusively to the basolateral membranes of these cells. The relatively high level of NHE-1 expression in epithelial cells, particularly those of the colon and stomach, suggests that NHE-1 function is important for the maintenance or regulation of ion transport processes that occur in these cell types.

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