scholarly journals Bacterial Wall Components such as Lipothecoid Acid, Peptidoglycan, Liposaccharide and Lipid A Stimulate Cell Proliferation in Intestinal Epithelial Cells

2001 ◽  
Vol 13 (2) ◽  
pp. 124-128
Author(s):  
Jaime H. Olaya, Vadim Neopikhanov,
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cells ◽  
Lipid A ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Stimulate Cell ◽  
Wall Components ◽  
Stimulate Cell Proliferation

Induction of endothelin-1 synthesis by IL-2 and its modulation of rat intestinal epithelial cell growth

1998 ◽  
Vol 275 (3) ◽  
pp. G556-G563 ◽  
Author(s):  
Takeharu Shigematsu ◽  
Soichiro Miura ◽  
Masahiko Hirokawa ◽  
Ryota Hokari ◽  
Hajime Higuchi ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Proliferative Response ◽  
Intestinal Epithelial Cell ◽  
Culture Media ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial

Endothelin (ET), a vasoconstrictive peptide, is known to have a variety of biological actions. Although ET is released by vascular endothelial cells, other cell populations also have been reported to synthesize and release ET. In this study, we examined whether ET is synthesized by intestinal epithelial cells and whether it affects induction of epithelial cell proliferation by interleukin-2 (IL-2). Subconfluent monolayers of intestinal epithelial cells (IEC-6 and IEC-18) were maintained in serum-free medium before addition of rat IL-2. Both IEC-6 and IEC-18 cells released ET-1 into the medium under unstimulated conditions, as determined by a sandwich ELISA. IL-2 significantly enhanced ET-1 release in a time-dependent manner. ET-3 was not detectable in the culture media of either cell line. Expression of ET-1 and ET-3 mRNA in epithelial cells was assessed by competitive PCR. Both cell lines were shown to express ET-1 mRNA, but no ET-3 mRNA was detected. IL-2 treatment enhanced ET-1 mRNA expression by both IEC-6 and IEC-18 cells. Both cell lines also expressed mRNA for ETA and ETB receptor subtypes. When cell proliferation was assessed, exogenous ET-1 induced a slight proliferative response in both types of cells that was consistent and significant at low ET-1 concentrations; cell growth was inhibited at a higher concentration (10−7M). IL-2 produced a significant proliferative response in both cell lines. However, the addition of ET-1 (10−7 M) to culture media attenuated the IL-2-induced increase in cell proliferation. ETA-receptor antagonists significantly enhanced cellular proliferation, suggesting involvement of the ETA receptor in modulation of IL-2-induced intestinal epithelial cell growth.

scholarly journals Human intestinal epithelial cell-induced CD8+ T cell activation is mediated through CD8 and the activation of CD8-associated p56lck.

1995 ◽  
Vol 182 (4) ◽  
pp. 1079-1088 ◽  
Author(s):  
Y Li ◽  
X Y Yio ◽  
L Mayer
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Intestinal Epithelial Cells ◽  
T Cell Proliferation ◽  
Intestinal Epithelial

The activation of CD8+ suppressor T cells by normal intestinal epithelial cells in antigen-specific or allogeneic mixed cell culture systems has significant implications for the regulation of mucosal immune responses. In this study, we found that the capacity of epithelial cells to induce CD8+ suppressor T cell activation appeared to be linked to the binding of CD8 molecules on the T cell surface. This appears to be mediated by a non-class I molecule expressed on the epithelial cell surface, which binds to CD8 and results in the activation of the CD8-associated src-like tyrosine kinase, p56lck. Epithelial cell-stimulated p56lck activation is an early event (in contrast to monocytes) and is essential for T cell activation, since proliferation could be completely abrogated by pretreatment of T cells with genestein or herbamycin, both of which are protein tyrosine kinase inhibitors. Pretreatment of T cells with anti-CD8 or of intestinal epithelial cells with an anti-epithelial cell mAb B9 inhibited p56lck activation and further confirmed that CD8 on the T cell and a CD8 ligand on the epithelial cell were involved in this T cell activation event. The specificity of this reaction was confirmed in experiments in which murine transfectants 3G4 and 3G8, expressing CD4 or CD8, respectively, were used. Coculture of 3G8 with epithelial cells but not with monocytes activated p56lck in this cell line, whereas p56lck was preferentially activated in 3G4 cells when monocytes were used as the stimulator cells. Although stimulation through CD8- and CD8-associated p56lck was important for epithelial cell-induced T cell activation, T cell proliferation could not be induced by cross-linking CD8 alone with monoclonal antibody anti-CD8. These data suggest that a second signal, possibly through the T cell antigen receptor since activation of the T cell receptor-associated kinase fyn was also seen, is required for epithelial cell-driven T cell proliferation.

scholarly journals JunD enhances miR-29b levels transcriptionally and posttranscriptionally to inhibit proliferation of intestinal epithelial cells

2015 ◽  
Vol 308 (10) ◽  
pp. C813-C824 ◽  
Author(s):  
Tongtong Zou ◽  
Jaladanki N. Rao ◽  
Lan Liu ◽  
Lan Xiao ◽  
Hee Kyoung Chung ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Transcription Factor ◽  
Epithelial Cells ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Intestinal Epithelial Cells ◽  
Inhibitory Effect ◽  
Microrna Expression ◽  
Intestinal Epithelial ◽  
Gut Epithelium

Through its actions as component of the activating protein-1 (AP-1) transcription factor, JunD potently represses cell proliferation. Here we report a novel function of JunD in the regulation of microRNA expression in intestinal epithelial cells (IECs). Ectopically expressed JunD specifically increased the expression of primary and mature forms of miR-29b, whereas JunD silencing inhibited miR-29b expression. JunD directly interacted with the miR-29b1 promoter via AP-1-binding sites, whereas mutation of AP-1 sites from the miR-29b1 promoter prevented JunD-mediated transcriptional activation of the miR-29b1 gene. JunD also enhanced formation of the Drosha microprocessor complex, thus further promoting miR-29b biogenesis. Cellular polyamines were found to regulate miR-29b expression by altering JunD abundance, since the increase in miR-29b expression levels in polyamine-deficient cells was abolished by JunD silencing. In addition, miR-29b silencing prevented JunD-induced repression of IEC proliferation. Our findings indicate that JunD activates miR-29b by enhancing its transcription and processing, which contribute to the inhibitory effect of JunD on IEC growth and maintenance of gut epithelium homeostasis.

Short- and long-term regulation of intestinal Na+/H+ exchange by Toll-like receptors TLR4 and TLR5

2015 ◽  
Vol 309 (8) ◽  
pp. G703-G715 ◽  
Author(s):  
José Miguel Cabral ◽  
Daniela Grácio ◽  
Patrício Soares-da-Silva ◽  
Fernando Magro
Keyword(s):  
Epithelial Cells ◽  
Lipid A ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Short Term ◽  
Monophosphoryl Lipid A ◽  
Nhe1 Activity ◽  
Short And Long Term ◽  
Tlr4 Activation

Inappropriate activation of pattern recognition receptors has been described as a potential trigger in the development of inflammatory bowel disease (IBD). In this study, we evaluated the activity and expression of Na+/H+ exchanger (NHE) subtypes in T84 intestinal epithelial cells during Toll-like receptor 4 (TLR4) activation by monophosphoryl lipid A and TLR5 by flagellin. NHE activity and intracellular pH were evaluated by spectrofluorescence. Additionally, kinase activities were evaluated by ELISA, and siRNA was used to specifically inhibit adenylyl cyclase (AC). Monophosphoryl lipid A (MPLA) (0.01–50.00 μg/ml) and flagellin (10–500 ng/ml) inhibited NHE1 activity in a concentration-dependent manner (MPLA short term −25.2 ± 5.0%, long term −31.9 ± 4.0%; flagellin short term −14.9 ± 2.0%, long term −19.1 ± 2.0%). Both ligands triggered AC3, PKA, PLC, and PKC signal molecules. Long-term exposure to flagellin and MPLA induced opposite changes on NHE3 activity; flagellin increased NHE3 activity (∼10%) with overexpression of membrane protein, whereas MPLA decreased NHE3 activity (−17.3 ± 3.0%). MPLA and flagellin simultaneously had synergistic effects on NHE activity. MPLA and flagellin impaired pHi recovery after intracellular acidification. The simultaneous exposure to MPLA and flagellin induced a substantial pHi reduction (−0.55 ± 0.03 pH units). Activation of TLR4 and TLR5 exerts marked inhibition of NHE1 activity in intestinal epithelial cells. Transduction mechanisms set into motion during TLR4-mediated and long-term TLR5-mediated inhibition of NHE1 activity involve AC3, PKA, PLC, and PKC. However, short- and long-term TLR4 activation and TLR5 activation might use different signaling pathways. The physiological alterations on intestinal epithelial cells described here may be useful in the development of better IBD therapeutics.

scholarly journals SOX9 directly regulates IGFBP-4 in the intestinal epithelium

2013 ◽  
Vol 305 (1) ◽  
pp. G74-G83 ◽  
Author(s):  
Zhongcheng Shi ◽  
Chi-I Chiang ◽  
Toni-Ann Mistretta ◽  
Angela Major ◽  
Yuko Mori-Akiyama
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Epithelial Cells ◽  
Target Genes ◽  
Intestinal Epithelial Cells ◽  
Neutralizing Antibody ◽  
Intestinal Epithelial ◽  
Loss Of Function ◽  
Deficient Mice

SOX9 regulates cell lineage specification by directly regulating target genes in a discrete number of tissues, and previous reports have shown cell proliferative and suppressive roles for SOX9. Although SOX9 is expressed in colorectal cancer, only a few direct targets have been identified in intestinal epithelial cells. We previously demonstrated increased proliferation in Sox9-deficient crypts through loss-of-function studies, indicating that SOX9 suppresses cell proliferation. In this study, crypt epithelial cells isolated from Sox9-deficient mice were used to identify potential target genes of SOX9. Insulin-like growth factor (IGF)-binding protein 4 (IGFBP-4), an inhibitor of the IGF/IGF receptor pathway, was significantly downregulated in Sox9-deficient intestinal epithelial cells and adenoma cells of Sox9-deficient Apc Min/+ mice. Immunolocalization experiments revealed that IGFBP-4 colocalized with SOX9 in mouse and human intestinal epithelial cells and in specimens from patients with primary colorectal cancer. Reporter assays and chromatin immunoprecipitation demonstrated direct binding of SOX9 to the IGFBP-4 promoter. Overexpression of SOX9 attenuated cell proliferation, which was restored following treatment with a neutralizing antibody against IGFBP-4. These results suggest that SOX9 regulates cell proliferation, at least in part via IGFBP-4. Furthermore, the antiproliferative effect of SOX9 was confirmed in vivo using Sox9-deficient mice, which showed increased tumor burden when bred with Apc Min/+ mice. Our results demonstrate, for the first time, that SOX9 is a transcriptional regulator of IGFBP-4 and that SOX9-induced activation of IGFBP-4 may be one of the mechanisms by which SOX9 suppresses cell proliferation and progression of colon cancer.

scholarly journals α-Chaconine Affects the Apoptosis, Mechanical Barrier Function, and Antioxidant Ability of Mouse Small Intestinal Epithelial Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuhua He ◽  
Jiaqi Chen ◽  
Qiyue Zhang ◽  
Jialong Zhang ◽  
Lulai Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cells ◽  
Barrier Function ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Antioxidant Ability ◽  
Glutamylcysteine Synthetase ◽  
A Cell ◽  
Small Intestinal ◽  
Mechanical Barrier

α-Chaconine is the most abundant glycoalkaloid in potato and toxic to the animal digestive system, but the mechanisms underlying the toxicity are unclear. In this study, mouse small intestinal epithelial cells were incubated with α-chaconine at 0, 0.4, and 0.8 μg/mL for 24, 48, and 72 h to examine apoptosis, mechanical barrier function, and antioxidant ability of the cells using a cell metabolic activity assay, flow cytometry, Western blot, immunofluorescence, and fluorescence quantitative PCR. The results showed that α-chaconine significantly decreased cell proliferation rate, increased apoptosis rate, decreased transepithelial electrical resistance (TEER) value, and increased alkaline phosphatase (AKP) and lactate dehydrogenase (LDH) activities, and there were interactions between α-chaconine concentration and incubation time. α-Chaconine significantly reduced the relative and mRNA expressions of genes coding tight junction proteins zonula occludens-1 (ZO-1) and occludin, increased malondialdehyde (MDA) content, decreased total glutathione (T-GSH) content, reduced the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and γ-glutamylcysteine synthetase (γ-GCS) and the mRNA expressions of SOD, CAT, GSH-Px, and γ-GCS genes. In conclusion, α-chaconine disrupts the cell cycle, destroys the mechanical barrier and permeability of mucosal epithelium, inhibits cell proliferation, and accelerates cell apoptosis.

scholarly journals PSIX-17 Investigating the biological activities of sodium cellobionate produced from cellulosic biomass

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 187-187
Author(s):  
Lauren Kovanda ◽  
Zhiliang Fan ◽  
Xunde Li ◽  
Yanhong Liu
Keyword(s):  
Cell Proliferation ◽  
Antimicrobial Activity ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial Cells ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Intestinal Epithelial

Abstract A novel method has been developed to easily hydrolyze cellulose to sodium cellobionate in a filamentous fungas, Neurospora crassa. The objectives of this experiment were to investigate the in vitro biological activities of sodium cellobionate. Antioxidant activity was evaluated with 3 chemical-based assays, including DPPH radical scavenging assay (DPPH), Trolox equivalent antioxidant capacity assay (TEAC), and ferric reducing antioxidant power assay (FRAP). Antimicrobial activity was determined as minimum inhibitory concentration (MIC) that prevented growth of tested bacteria, including four gram-negative bacteria (Escherichia coli F18 and ATCC 25922, and Salmonella Typhimurium ATCC 14028 and a wild strain isolated from cull diary cows in California) and one gram-positive bacteria (Enterococcus faecalis ATCC 29212). Anti-inflammatory activity was tested by analyzing TNF-α production with porcine alveolar macrophages that were challenged with lipopolysaccharide. A porcine intestinal epithelial cell line, IPEC-J2, was also used to test the effects of cellobionate on cell proliferation of intestinal epithelial cells. The tested doses of sodium cellobionate were 0, 0.04, 0.20, 1.00, 2.00, 4.00, 20.00, and 40.00 mg/mL. All assays were performed with over 6 replicates, except that MIC assays were performed as triplicate. All data were analyzed by PROC MIXED of SAS. Sodium cellobionate did not have radical scavenging capacity, but had weak FRAP (9.68 μM L-Cysteine equivalent) and TEAC (69% reduction) at the dose of 40 mg/mL. MIC results revealed that sodium cellobionate did not inhibit the growth of all tested bacteria, indicating it does not have antimicrobial activity within the range of tested doses. Sodium cellobionate did not exhibit anti-inflammatory activities, but significantly enhanced (P < 0.05) intestinal epithelial cell proliferation in vitro by 24.00%, 39.64%, and 25.98% when the doses were 1.00, 2.00, and 4.00 mg/mL, respectively. Results of this experiment indicate that cellobionate has limited biological activities in vitro, except that this biomass product could strongly stimulate the proliferation of intestinal epithelial cells. Future research will focus on the potential impacts of sodium cellobionate on intestinal physiology in vivo.

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