Monochloramine induces reorganization of nuclear speckles and phosphorylation of SRp30 in human colonic epithelial cells: role of protein kinase C

2003 ◽  
Vol 285 (5) ◽  
pp. C1294-C1303 ◽  
Author(s):  
Ya-Qin Zhu ◽  
Yu Lu ◽  
Xiao-Di Tan
Keyword(s):  
Gastrointestinal Tract ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Morphological Changes ◽  
Sr Proteins ◽  
Mrna Splicing ◽  
Intestinal Epithelial ◽  
Nuclear Speckles ◽  
Colonic Epithelial Cells ◽  
Stimulation Of

Intestinal epithelial cells are constantly stimulated by reactive oxidant metabolites (ROMs) in inflamed mucosa. Monochloramine (NH2Cl), a cell-permeant ROM, is particularly relevant to the pathogenesis of inflammation in the gastrointestinal tract. Nuclear speckles, a unique nuclear subcompartment, accumulate a family of proteins, namely, serine- and arginine-rich (SR) proteins. They play important roles in regulation of pre-mRNA splicing. Currently, little is known about the link between inflammatory stimulation and the pre-mRNA splicing process, although gene expression is changed in inflamed tissues. The present study was designed to investigate whether stimulation of human colonic epithelial cells (HT-29 and Caco-2 cell lines) with NH2Cl affects nuclear speckles and their components. By indirect immunofluorescence, nuclear speckles have been shown to undergo rapid aggregation after NH2Cl stimulation. By utilizing Western blotting, SRp30 (a subset of SR proteins) in intestinal epithelial cells was found to be phosphorylated after NH2Cl treatment, whereas other SR proteins were not responsive to NH2Cl stimulation. The cytotoxic effect of NH2Cl was excluded by both negative lactate dehydrogenase assay and propidium iodide staining. Therefore, NH2Cl-induced morphological changes on nuclear speckles and phosphorylated SRp30 do not result from intestinal epithelial injury. Furthermore, the effect of NH2Cl on nuclear speckles and SRp30 was blocked by bisindolylmaleimide I, a selective PKC inhibitor. Together, the available data suggest that stimulation of intestinal epithelial cells with NH2Cl results in a consequent change on pre-mRNA splicing machinery via a distinctive signal pathway involving activation of PKC. This effect may contribute to oxidant-induced pathophysiological changes in the gastrointestinal tract.

Alteration of gene expression by intestinal epithelial cells precedes colitis in interleukin-2-deficient mice

1998 ◽  
Vol 274 (3) ◽  
pp. G472-G479 ◽  
Author(s):  
Maarten A. C. Meijssen ◽  
Steven L. Brandwein ◽  
Hans-Christian Reinecker ◽  
Atul K. Bhan ◽  
Daniel K. Podolsky
Keyword(s):  
Epithelial Cells ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Colonic Epithelial Cells ◽  
Tnf Α ◽  
Small Intestinal ◽  
Cd14 Mrna ◽  
Tgf Β1

Intestinal epithelial cells may be actively involved in the immunoregulatory pathways leading to intestinal inflammation. The aim of this study was to assess expression by intestinal epithelial cells of cytokines with potential involvement in the development of intestinal inflammation in interleukin (IL)-2-deficient [(−/−)] mice. Wild-type mice, mice heterozygous for the disrupted IL-2 gene, and IL-2(−/−) mice were studied at 6, 16, and 24 wk of age. The mRNA levels of transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), IL-1β, IL-6, IL-15, KC, JE, and CD14 in colonic and small intestinal epithelial cells were assessed by Northern blot analysis. CD14 was also measured by Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR). TGF-β1 mRNA was constitutively expressed in both colonic and small intestinal epithelial cells with increased expression in the colonic epithelium of colitic mice. CD14 was detected only in colonic epithelial cells, and mRNA levels increased severalfold in IL-2(−/−) mice with colitis. Northern analysis demonstrated increased levels of TGF-β1 and CD14 mRNA in colonic epithelial cells of IL-2(−/−) mice before the development of signs of colitis. CD14 mRNA and protein expression in the epithelial cells of colitic mice were confirmed by RT-PCR and Western blot analysis of isolated cells. In addition, IL-2(−/−) mice also expressed increased levels of IL-15 mRNA in small intestinal and colonic epithelial cells compared with heterozygous control mice. TNF-α, IL-1β, IL-6, KC, and JE mRNAs were only detectable in colonic epithelial cells of mice after the onset of colitis. Enhanced expression of TGF-β1, IL-15, and CD14 by colonic epithelial cells may play a role in the subsequent development of colitis in IL-2(−/−) mice.

On the mechanism of folate transport in isolated intestinal epithelial cells

1981 ◽  
Vol 240 (2) ◽  
pp. G170-G175 ◽  
Author(s):  
Y. Eilam ◽  
M. Ariel ◽  
M. Jablonska ◽  
N. Grossowicz
Keyword(s):  
Steady State ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
State Level ◽  
Metabolic Inhibitors ◽  
Intestinal Epithelial ◽  
Coupled Transport ◽  
Folate Transport ◽  
Kinetics Of ◽  
Stimulation Of

The mechanism of folic acid (FA) uptake was studied in isolated intestinal epithelial cells prepared from 2- to 6-wk-old chicks. The cells accumulated FA, reaching a level of three- to fivefold that at equilibrium. In the presence of the metabolic inhibitors, NaN3 or KCN, FA was taken up only until equilibration while accumulation of FA was inhibited. Addition of these inhibitors at a steady state of FA accumulation caused a release of intracellular FA. The kinetics of FA uptake were found to be saturable (Km = 3.5 x 10(-5) M), indicating a carrier-mediated mechanism. The steady-state level of FA accumulation was higher as the concentration of NA+ in the medium increased from 0 to 120 mM. This stimulation of FA uptake by Na+ was not due to the stimulation of glucose uptake, because in experiments carried out in the presence of phlorizin, a glucose-transport inhibitor, FA accumulation was not diminished. It is suggested that FA is taken up by a Na+-coupled transport system.

scholarly journals Differential expression of endothelin-2 along the mouse intestinal tract

2005 ◽  
Vol 35 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Satoshi Takizawa ◽  
Tsuyoshi Uchide ◽  
Javier Adur ◽  
Takaharu Kozakai ◽  
Eiichi Kotake-Nara ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Epithelial Cells ◽  
Intestinal Tract ◽  
Intestinal Epithelial Cells ◽  
Immunohistochemical Analysis ◽  
Pcr Analysis ◽  
Intestinal Epithelial ◽  
Peyer’S Patch ◽  
Peyer's Patch ◽  
Specific Distribution

Endothelin (ET)-2, an ET family peptide, is highly expressed in intestine. However, the specific distribution and function of ET-2 remain unknown. We elucidated the expression profile and localization of ET-2 in mouse gastrointestinal tract. Real-time PCR analysis revealed that ET-2 gene expression in the gastrointestinal tract of healthy animals was relatively high in the colon. Immunohistochemical analysis revealed ET-2-like immunoreactivity mainly in epithelial cells of the mucosa throughout the intestinal tract of healthy animals. Intracellularly, ET-2 was concentrated close to the basement membrane of intestinal epithelial cells. A weak ET-2-like immunoreactivity was also localized to some neurofibers and the myenteric plexus of the muscle layer, coexpressing with vasoactive intestinal peptide. ET-2-like immunoreactivity was also detected at Brunner’s glands of the duodenum and follicle-associated epithelium of Peyer’s patch. In contrast, ET-1-like immunoreactivity was uniformly distributed in epithelial cells. In dextran sulfate sodium (DSS)-induced colitis, colonic ET-2 was upregulated during the late stage of DSS treatment. These results suggest that in intestinal epithelial cells ET-2 could be secreted into the lamina propria and the dome region in Peyer’s patch, and that it might modulate immune cells in these sites for mucosal defense.

Sign in / Sign up

Export Citation Format

Share Document