NHE2 and NHE3 are human and rabbit intestinal brush-border proteins

1996 ◽  
Vol 270 (1) ◽  
pp. G29-G41 ◽  
Author(s):  
W. A. Hoogerwerf ◽  
S. C. Tsao ◽  
O. Devuyst ◽  
S. A. Levine ◽  
C. H. Yun ◽  
...  
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Brush Border ◽  
Basolateral Membrane ◽  
Goblet Cells ◽  
Basolateral Membranes ◽  
Western Analysis ◽  
Rabbit Jejunum ◽  
Colon And Rectum ◽  
Descending Colon

Rabbit NHE2 and NHE3 are two epithelial isoform Na+/H+ exchangers (NHE), the messages for which are found predominantly and entirely, respectively, in renal, intestinal, and gastric mucosa. The current studies used Western analysis and immunohistochemistry to identify and characterize the apical vs. basolateral membrane distribution of NHE2 and NHE3 in intestinal epithelial cells. Based on Western analysis, NHE2 and NHE3 both are present in brush-border but not basolateral membranes of small intestine. Both NHE2 and NHE3 are 85-kDa proteins. Consistent with Western analysis, NHE2 and NHE3 are immunolocalired to the brush-border but not basolateral membranes of villus epithelial cells, but not goblet cells, in human jejunum and ileum and in surface epithelial cells in the ascending and descending colon and rectum. In addition, NHE2 and NHE3 are present in small amounts in the crypt cell brush border of human jejunum, ileum, ascending and descending colon, and rectum. In rabbit jejunum, ileum, and ascending colon, NHE2 and NHE3 are present in the brush border of epithelial and not goblet cells, again much more in the villus (small intestine)/ surface cells (colon) than the crypt. NHE2 but not NHE3 is present in the brush border of rabbit descending colon surface cells and in small amounts in crypt cells. NHE2 and NHE3 are both human and rabbit small intestinal and colonic epithelial cell brush-border Na+/H+ exchanger isoforms that colocalize in all intestinal segments except rabbit descending colon, which lacks NHE3.

scholarly journals (Na+ + K+)-ATPase and plasma membrane polarity of intestinal epithelial cells: presence of a brush border antigen in the distal large intestine that is immunologically related to beta subunit.

1989 ◽  
Vol 109 (3) ◽  
pp. 1057-1069 ◽  
Author(s):  
A Marxer ◽  
B Stieger ◽  
A Quaroni ◽  
M Kashgarian ◽  
H P Hauri
Keyword(s):  
Monoclonal Antibody ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Brush Border ◽  
Basolateral Membrane ◽  
Apical Cell ◽  
Distal Colon ◽  
Proximal Colon ◽  
Beta Subunit ◽  
Cell Pole

The previously produced monoclonal antibody IEC 1/48 against cultured rat intestinal crypt cells (Quaroni, A., and K. J. Isselbacher. 1981. J. Natl. Cancer Inst. 67:1353-1362) was extensively characterized and found to be directed against the beta subunit of (Na+ + K+)-ATPase as assessed by immunological and enzymatic criteria. Under nondenaturing conditions the antibody precipitated the alpha-beta enzyme complex (98,000 and 48,000 Mr). This probe, together with the monoclonal antibody C 62.4 against the alpha subunit (Kashgarian, M., D. Biemesderfer, M. Caplan, and B. Forbush. 1985. Kidney Int. 28:899-913), was used to localize (Na+ + K+)-ATPase in epithelial cells along the rat intestinal tract by immunofluorescence and immunoelectron microscopy. Both antibodies exclusively labeled the basolateral membrane of small intestine and proximal colon epithelial cells. However, in the distal colon, IEC 1/48, but not C 62.4, also labeled the brush border membrane. The cross-reacting beta-subunit-like antigen on the apical cell pole was tightly associated with isolated brush borders but was apparently devoid of (Na+ + K+)-ATPase activity. Subcellular fractionation of colonocytes in conjunction with limited proteolysis and surface radioiodination of intestinal segments suggested that the cross-reacting antigen in the brush border may be very similar to the beta subunit. The results support the notion that in the small intestine and proximal colon the enzyme subunits are exclusively targeted to the basolateral membrane while in the distal colon nonassembled beta subunit or a beta-subunit-like protein is also transported to the apical cell pole.

Expression and localization of aquaporins in rat gastrointestinal tract

1999 ◽  
Vol 276 (3) ◽  
pp. C621-C627 ◽  
Author(s):  
Yu Koyama ◽  
Tadashi Yamamoto ◽  
Tatsuo Tani ◽  
Kouei Nihei ◽  
Daisuke Kondo ◽  
...  
Keyword(s):  
Small Intestine ◽  
In Situ Hybridization ◽  
Gastrointestinal Tract ◽  
Epithelial Cells ◽  
Cellular Localization ◽  
Basolateral Membrane ◽  
Rnase Protection Assay ◽  
Rnase Protection ◽  
Basolateral Membranes

A family of water-selective channels, aquaporins (AQP), has been demonstrated in various organs and tissues. However, the localization and expression of the AQP family members in the gastrointestinal tract have not been entirely elucidated. This study aimed to demonstrate the expression and distribution of several types of the AQP family and to speculate on their role in water transport in the rat gastrointestinal tract. By RNase protection assay, expression of AQP1–5 and AQP8 was examined in various portions through the gastrointestinal tract. AQP1 and AQP3 mRNAs were diffusely expressed from esophagus to colon, and their expression was relatively intense in the small intestine and colon. In contrast, AQP4 mRNA was selectively expressed in the stomach and small intestine and AQP8 mRNA in the jejunum and colon. Immunohistochemistry and in situ hybridization demonstrated cellular localization of these AQP in these portions. AQP1 was localized on endothelial cells of lymphatic vessels in the submucosa and lamina propria throughout the gastrointestinal tract. AQP3 was detected on the circumferential plasma membranes of stratified squamous epithelial cells in the esophagus and basolateral membranes of cardiac gland epithelia in the lower stomach and of surface columnar epithelia in the colon. However, AQP3 was not apparently detected in the small intestine. AQP4 was present on the basolateral membrane of the parietal cells in the lower stomach and selectively in the basolateral membranes of deep intestinal gland cells in the small intestine. AQP8 mRNA expression was demonstrated in the absorptive columnar epithelial cells of the jejunum and colon by in situ hybridization. These findings may indicate that water crosses the epithelial layer through these water channels, suggesting a possible role of the transcellular route for water intake or outlet in the gastrointestinal tract.

Subcellular distribution of nucleotide cyclases in rat intestinal epithelium.

1978 ◽  
Vol 235 (5) ◽  
pp. E539 ◽  
Author(s):  
M W Walling ◽  
A K Mircheff ◽  
C H Van Os ◽  
E M Wright
Keyword(s):  
Adenylate Cyclase ◽  
Guanylate Cyclase ◽  
Brush Border ◽  
Linear Regression Analysis ◽  
Basolateral Membrane ◽  
Multiple Linear Regression Analysis ◽  
Isolated Cells ◽  
Basolateral Membranes ◽  
Rat Duodenum ◽  
Triton X

The subcellular distributions of adenylate cyclase and guanylate cyclase were determined for the mature enterocyte from the rat duodenum. Brush-border and basolateral membranes were prepared from isolated cells by an analytical isolation procedure, and multiple linear regression analysis was used to obtain a quantitative estimate of the distribution of recovered cyclase activities between the brush borders and basolateral membranes. Adenylate cyclase was largely confined to the basolateral surface of the epithelium, whereas guanylate cyclase was found on the brush-border and basolateral membrane fractions in the ratio 2.4:1. There was no evidence for the presence of nucleotide cyclases in the cytosol. Guanylate cyclase in both the brush-border and basolateral membranes was stimulated by epinephrine, insulin, and Triton X-100, but not by carbachol. Adenylate cyclase was not influenced by epinephrine, but was markedly stimulated by NaF and vasoactive intestinal peptide. These results are discussed in relation to the effects of hormones on transport across the small intestine.

scholarly journals Putative linear motifs mediate the trafficking to apical and basolateral membranes

2020 ◽  
Author(s):  
Laszlo Dobson ◽  
András Zeke ◽  
Levente Szekeres ◽  
Tamás Langó ◽  
Gábor Tusnády
Keyword(s):  
Epithelial Cells ◽  
Drug Transport ◽  
Basolateral Membrane ◽  
Transmembrane Proteins ◽  
Transport Processes ◽  
Membrane Domains ◽  
Protein Distribution ◽  
Basolateral Membranes ◽  
Linear Motifs ◽  
Cellular Components

AbstractCell polarity refers to the asymmetric organisation of cellular components in various cells. Epithelial cells are the best known examples of polarized cells, featuring apical and basolateral membrane domains. Despite huge efforts, the exact rules governing the protein distribution in such domains are still elusive. In this study we examined linear motifs accumulating in these parts and based on the results we prepared ‘Classical’ and Convolutional Neural Networks to classify human transmembrane proteins localizing into apical/basolateral membranes. Asymmetric expression of drug transporters results in vectorial drug transport, governing the pharmacokinetics of numerous substances, yet the data on how proteins are sorted in epithelial cells is very scattered. The provided dataset may offer help to experimentalists to characterize novel molecular targets to regulate transport processes more precisely.

Selective permeability barrier to urea in shark rectal gland

2005 ◽  
Vol 289 (1) ◽  
pp. F83-F89 ◽  
Author(s):  
Joshua D. Zeidel ◽  
John C. Mathai ◽  
John D. Campbell ◽  
Wily G. Ruiz ◽  
Gerard L. Apodaca ◽  
...  
Keyword(s):  
Activation Energy ◽  
Epithelial Cells ◽  
Water Flow ◽  
Water Permeability ◽  
Apical Membrane ◽  
Basolateral Membrane ◽  
Water Flux ◽  
Rectal Gland ◽  
Basolateral Membranes ◽  
Urea Permeability

Elasmobranchs such as the dogfish shark Squalus acanthius achieve osmotic homeostasis by maintaining urea concentrations in the 300- to 400-mM range, thus offsetting to some degree ambient marine osmolalities of 900–1,000 mosmol/kgH2O. These creatures also maintain salt balance without losing urea by secreting a NaCl-rich (500 mM) and urea-poor (18 mM) fluid from the rectal gland that is isotonic with the plasma. The composition of the rectal gland fluid suggests that its epithelial cells are permeable to water and not to urea. Because previous work showed that lipid bilayers that permit water flux do not block flux of urea, we reasoned that the plasma membranes of rectal gland epithelial cells must either have aquaporin water channels or must have some selective barrier to urea flux. We therefore isolated apical and basolateral membranes from shark rectal glands and determined their permeabilities to water and urea. Apical membrane fractions were markedly enriched for Na-K-2Cl cotransporter, whereas basolateral membrane fractions were enriched for Na-K-ATPase. Basolateral membrane osmotic water permeability (Pf) averaged 4.3 ± 1.3 × 10−3 cm/s, whereas urea permeability averaged 4.2 ± 0.8 × 10−7 cm/s. The activation energy for water flow averaged 16.4 kcal/mol. Apical membrane Pf averaged 7.5 ± 1.6 × 10−4 cm/s, and urea permeability averaged 2.2 ± 0.4 × 10−7 cm/s, with an average activation energy for water flow of 18.6 kcal/mol. The relatively low water permeabilities and high activation energies argue strongly against water flux via aquaporins. Comparison of membrane water and urea permeabilities with those of artificial liposomes and other isolated biological membranes indicates that the basolateral membrane urea permeability is fivefold lower than would be anticipated for its water permeability. These results indicate that the rectal gland maintains a selective barrier to urea in its basolateral membranes.

Transport of citrate across the brush border and basolateral membrane of rat small intestine

1994 ◽  
Vol 109 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Siegfried Wolffram ◽  
Rene Unternährer ◽  
Beat Grenacher ◽  
Erwin Scharrer
Keyword(s):  
Small Intestine ◽  
Brush Border ◽  
Basolateral Membrane ◽  
Rat Small Intestine

scholarly journals Basolateral membrane K+ channels in renal epithelial cells

2012 ◽  
Vol 302 (9) ◽  
pp. F1069-F1081 ◽  
Author(s):  
Kirk L. Hamilton ◽  
Daniel C. Devor
Keyword(s):  
Epithelial Cells ◽  
Collecting Duct ◽  
Basolateral Membrane ◽  
Gene Families ◽  
Proper Function ◽  
Major Function ◽  
Basolateral Membranes ◽  
Family Approach ◽  
Membrane Transport Proteins ◽  
Significant Disease

The major function of epithelial tissues is to maintain proper ion, solute, and water homeostasis. The tubule of the renal nephron has an amazingly simple structure, lined by epithelial cells, yet the segments (i.e., proximal tubule vs. collecting duct) of the nephron have unique transport functions. The functional differences are because epithelial cells are polarized and thus possess different patterns (distributions) of membrane transport proteins in the apical and basolateral membranes of the cell. K+ channels play critical roles in normal physiology. Over 90 different genes for K+ channels have been identified in the human genome. Epithelial K+ channels can be located within either or both the apical and basolateral membranes of the cell. One of the primary functions of basolateral K+ channels is to recycle K+ across the basolateral membrane for proper function of the Na+-K+-ATPase, among other functions. Mutations of these channels can cause significant disease. The focus of this review is to provide an overview of the basolateral K+ channels of the nephron, providing potential physiological functions and pathophysiology of these channels, where appropriate. We have taken a “K+ channel gene family” approach in presenting the representative basolateral K+ channels of the nephron. The basolateral K+ channels of the renal epithelia are represented by members of the KCNK, KCNJ, KCNQ, KCNE, and SLO gene families.

scholarly journals Epidemiologi Kriptosporidiosis

2017 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Esy Maryanti
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Single Cell ◽  
Brush Border ◽  
Opportunistic Infections ◽  
Immunocompromised Patient ◽  
Common Species

Cryptosporidiosis is a disease caused by Cryptosporidium sp. Cryptosporidium sp. are single cell of coccidian caninfected human and animals. Cryptosporidiosis are considered a cause of emerging and opportunistic infections inhuman. Oocysts of Cryptosporidium are ovoid or spherical and 4 to 6 micrometers diameters. The parasite is located inthe brush border of the epithelial cells of the small intestine. Currently, eight species of Cryptosporidium are known toinfect human and there are two species, C parvum and C muris which most common species reported to infect childrenand immunocompromised patient especially AIDS patient with diarrhea.

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