scholarly journals Basic helix–loop–helix protein E47-mediated p21Waf1/Cip1 gene expression regulates apoptosis of intestinal epithelial cells

2007 ◽  
Vol 407 (2) ◽  
pp. 243-254 ◽  
Author(s):  
Sujoy Bhattacharya ◽  
Huazhang Guo ◽  
Ramesh M. Ray ◽  
Leonard R. Johnson
Keyword(s):  
Epithelial Cells ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Protein Levels ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Apoptotic Protein

Inhibition of ornithine decarboxylase by DFMO (α-difluromethylornithine) and subsequent polyamine depletion increases p21Cip1 protein, induces cell cycle arrest and confers resistance to apoptosis on intestinal epithelial cells. However, the mechanism by which polyamines regulate p21Cip1 expression and apoptosis is unknown. On the basis of the involvement of p21Cip1 as an anti-apoptotic protein, we tested the role of p21Cip1 in providing protection from apoptosis. Simultaneously, we investigated the role of E47, a basic helix–loop–helix protein, in the regulation of p21Cip1 gene transcription. Gene-specific siRNA (small interfering RNA) decreased E47 protein levels, increased p21Cip1 promoter activity and protein levels and protected cells from TNFα (tumour necrosis factor α)-induced apoptosis. Knockdown of p21Cip1 protein by siRNA resulted in cells becoming more susceptible to apoptosis. In contrast, incubation with EGF (epidermal growth factor) stimulated p21Cip1 mRNA and protein levels and rescued cells from apoptosis. During apoptosis, the level of E47 mRNA increased, causing a concomitant decrease in p21Cip1 mRNA and protein levels. Polyamine depletion decreased E47 mRNA levels and cell survival. Caspase 3-mediated cleavage of p130Cas has been implicated in p21Cip1 transcription. The progression of apoptosis led to a caspase 3-dependent cleavage of p130Cas and generated a 31 kDa fragment, which translocated to the nucleus, associated with nuclear E47 and inhibited p21Cip1 transcription. Polyamine depletion inhibited all these effects. Transient expression of the 31 kDa fragment prevented the expression of p21Cip1 protein and increased apoptosis. These results implicate p21Cip1 as an anti-apoptotic protein and suggest a role for polyamines in the regulation of p21Cip1 via the transcription repressor E47. Caspase-mediated cleavage of p130Cas generates a 31 kDa fragment, inhibits p21Cip1 transcription and acts as an amplifier of apoptotic signalling.

scholarly journals Baicalin-Induced Autophagy Preserved LPS-Stimulated Intestinal Cells from Inflammation and Alterations of Paracellular Permeability

2021 ◽  
Vol 22 (5) ◽  
pp. 2315
Author(s):  
Valentina Rizzo ◽  
Nadia Ferlazzo ◽  
Monica Currò ◽  
Gaetano Isola ◽  
Marco Matarese ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Paracellular Permeability ◽  
Autophagic Flux ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Beneficial Effects ◽  
Protein Levels ◽  
Inflammatory Conditions ◽  
Anti Inflammatory

Several studies have demonstrated a relevant role of intestinal epithelial cells in the immune response and in chronic inflammatory conditions, including ulcers, colitis, and Crohn’s disease. Baicalin (BA), extracted from the root of Scutellaria baicalensis, has various beneficial healthy effects, including anti-inflammatory activity. However, few studies have evaluated BA effects on autophagic signaling in epithelial cell response to inflammatory stimuli. To explore possible beneficial effects of BA, HT-29 cells were exposed to lipopolysaccharide (LPS), in presence or absence of BA, for 4 h. We evaluated mRNA levels of autophagy-related genes and cytokines, triggering inflammatory response. Furthermore, the expression of claudin 1, involved in the regulation of paracellular permeability was analyzed. BA treatment repressed LPS-induced expression of TNF-α and IL-1β. The down-regulation of autophagy-related genes induced by LPS was counteracted by cell pretreatment with BA. Under these conditions, BA reduced the NF-κB activation caused by LPS. Also, BA restored mRNA and protein levels of claudin 1, which were reduced by LPS. In conclusion, in intestinal epithelial cells BA regulates the NF-κB activation and modulates both autophagic and inflammatory processes, leading to an improvement of paracellular permeability. These results suggest that the anti-inflammatory effects of BA can be associated to the regulation of autophagic flux.

scholarly journals Clostridium difficile toxins A and B decrease intestinal SLC26A3 protein expression

2018 ◽  
Vol 315 (1) ◽  
pp. G43-G52 ◽  
Author(s):  
Hayley Coffing ◽  
Shubha Priyamvada ◽  
Arivarasu N. Anbazhagan ◽  
Christine Salibay ◽  
Melinda Engevik ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Critical Factor ◽  
The United States ◽  
Mrna Levels ◽  
Apical Surface ◽  
Intestinal Epithelial ◽  
Protein Levels ◽  
Anion Transporter

Clostridium difficile infection (CDI) is the primary cause of nosocomial diarrhea in the United States. Although C. difficile toxins A and B are the primary mediators of CDI, the overall pathophysiology underlying C. difficile-associated diarrhea remains poorly understood. Studies have shown that a decrease in both NHE3 (Na+/H+ exchanger) and DRA (downregulated in adenoma, Cl−/[Formula: see text] exchanger), resulting in decreased electrolyte absorption, is implicated in infectious and inflammatory diarrhea. Furthermore, studies have shown that NHE3 is depleted at the apical surface of intestinal epithelial cells and downregulated in patients with CDI, but the role of DRA in CDI remains unknown. In the current studies, we examined the effects of C. difficile toxins TcdA and TcdB on DRA protein and mRNA levels in intestinal epithelial cells (IECs). Our data demonstrated that DRA protein levels were significantly reduced in response to TcdA and TcdB in IECs in culture. This effect was also specific to DRA, as NHE3 and PAT-1 (putative anion transporter 1) protein levels were unaffected by TcdA and TcdB. Additionally, purified TcdA and TcdA + TcdB, but not TcdB, resulted in a decrease in colonic DRA protein levels in a toxigenic mouse model of CDI. Finally, patients with recurrent CDI also exhibited significantly reduced expression of colonic DRA protein. Together, these findings indicate that C. difficile toxins markedly downregulate intestinal expression of DRA which may contribute to the diarrheal phenotype of CDI. NEW & NOTEWORTHY Our studies demonstrate, for the first time, that C. difficile toxins reduce DRA protein, but not mRNA, levels in intestinal epithelial cells. These findings suggest that a downregulation of DRA may be a critical factor in C. difficile infection-associated diarrhea.

Prevention of Dextran Sulfate Sodium-induced Mouse Colitis by a Fungal Protein Ling Zhi-8 via Promoting the Barrier Function of Intestinal Epithelial Cells

2021 ◽  
Author(s):  
Yu-Huan Chen ◽  
Jenn-Yeu Shin ◽  
Hsiu-Mei Wei ◽  
Chi-Chen Lin ◽  
Linda Chia-Hui Yu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Immune Cells ◽  
Ganoderma Lucidum ◽  
Dextran Sulfate ◽  
Dextran Sulfate Sodium ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Fungal Protein ◽  
Fungal Immunomodulatory Protein

A fungal immunomodulatory protein Ling Zhi-8 (LZ-8) isolated from Ganoderma lucidum (GL) regulates immune cells and inhibits tumor growth; however, the role of LZ-8 in intestinal epithelial cells (IECs) is...

scholarly journals Rspo3 regulates the abnormal differentiation of small intestinal epithelial cells in diabetic state

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ti-Dong Shan ◽  
Han Yue ◽  
Xue-Guo Sun ◽  
Yue-Ping Jiang ◽  
Li Chen
Keyword(s):  
Epithelial Cells ◽  
Bioinformatics Analysis ◽  
Intestinal Epithelial Cells ◽  
Underlying Mechanism ◽  
Luciferase Reporter ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Diabetic State ◽  
Definitive Evidence

Abstract Background The complications caused by diabetes mellitus (DM) are the focus of clinical treatment. However, little is known about diabetic enteropathy (DE) and its potential underlying mechanism. Methods Intestinal epithelial cells (IECs) and intestinal epithelial stem cells (IESCs) were harvested from BKS.Cg-Dock7m+/+Leprdb/JNju (DM) mice, and the expression of R-Spondin 3 (Rspo3) was detected by RT-qPCR, Western blotting, immunohistochemistry, and immunofluorescence. The role of Rspo3 in the abnormal differentiation of IECs during DM was confirmed by knockdown experiments. Through miRNA expression profiling, bioinformatics analysis, and RT-qPCR, we further analyzed the differentiation-related miRNAs in the IECs from mice with DM. Results Abnormal differentiation of IECs was observed in the mice with DM. The expression of Rspo3 was upregulated in the IECs from the mice with DM. This phenomenon was associated with Rspo3 overexpression. Additionally, Rspo3 is a major determinant of Lgr5+ stem cell identity in the diabetic state. Microarray analysis, bioinformatics analysis, and luciferase reporter assays revealed that microRNA (miR)-380-5p directly targeted Rspo3. Moreover, miR-380-5p upregulation was observed to attenuate the abnormal differentiation of IECs by regulating Rspo3 expression. Conclusions Together, our results provide definitive evidence of the essential role of Rspo3 in the differentiation of IECs in DM.

scholarly journals Protective role of berberine on ulcerative colitis through modulating enteric glial cells–intestinal epithelial cells–immune cells interactions

2020 ◽  
Vol 10 (3) ◽  
pp. 447-461 ◽  
Author(s):  
Heng Li ◽  
Chen Fan ◽  
Huimin Lu ◽  
Chunlan Feng ◽  
Peilan He ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Epithelial Cells ◽  
Glial Cells ◽  
Immune Cells ◽  
Intestinal Epithelial Cells ◽  
Protective Role ◽  
Intestinal Epithelial ◽  
Enteric Glial Cells

Cholera Toxin Destabilizes Retromer to Inhibit NA + /H + Exchanger3 Activity in Intestinal Epithelial Cells- Possible Therapeutic Role of a Retromer Stabilizer in Treating Diarrhea

2017 ◽  
Vol 152 (5) ◽  
pp. S67
Author(s):  
Varsha Singh ◽  
Jianbo Yang ◽  
Jianyi Yin ◽  
Ming Tse ◽  
Nicholas C. Zachos ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cholera Toxin ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Therapeutic Role

Role of chemokine receptors and intestinal epithelial cells in the mucosal inflammation and tolerance

2016 ◽  
Vol 101 (2) ◽  
pp. 377-394 ◽  
Author(s):  
Neeraja Kulkarni ◽  
Manisha Pathak ◽  
Girdhari Lal
Keyword(s):  
Epithelial Cells ◽  
Chemokine Receptors ◽  
Intestinal Epithelial Cells ◽  
Mucosal Inflammation ◽  
Intestinal Epithelial

scholarly journals Expression of lysophosphatidic acid receptor 5 is necessary for the regulation of intestinal Na+/H+ exchanger 3 by lysophosphatidic acid in vivo

2018 ◽  
Vol 315 (4) ◽  
pp. G433-G442 ◽  
Author(s):  
Kayte A. Jenkin ◽  
Peijian He ◽  
C. Chris Yun
Keyword(s):  
Epithelial Cells ◽  
Lysophosphatidic Acid ◽  
Direct Evidence ◽  
Intestinal Epithelial Cells ◽  
Regulatory Role ◽  
Intestinal Epithelial ◽  
Fluid Absorption ◽  
Wild Type

Lysophosphatidic acid (LPA) is a bioactive lipid molecule, which regulates a broad range of pathophysiological processes. Recent studies have demonstrated that LPA modulates electrolyte flux in the intestine, and its potential as an antidiarrheal agent has been suggested. Of six LPA receptors, LPA5 is highly expressed in the intestine. Recent studies by our group have demonstrated activation of Na+/H+ exchanger 3 (NHE3) by LPA5. However, much of what has been elucidated was achieved using colonic cell lines that were transfected to express LPA5. In the current study, we engineered a mouse that lacks LPA5 in intestinal epithelial cells, Lpar5ΔIEC, and investigated the role of LPA5 in NHE3 regulation and fluid absorption in vivo. The intestine of Lpar5ΔIEC mice appeared morphologically normal, and the stool frequency and fecal water content were unchanged compared with wild-type mice. Basal rates of NHE3 activity and fluid absorption and total NHE3 expression were not changed in Lpar5ΔIEC mice. However, LPA did not activate NHE3 activity or fluid absorption in Lpar5ΔIEC mice, providing direct evidence for the regulatory role of LPA5. NHE3 activation involves trafficking of NHE3 from the terminal web to microvilli, and this mobilization of NHE3 by LPA was abolished in Lpar5ΔIEC mice. Dysregulation of NHE3 was specific to LPA, and insulin and cholera toxin were able to stimulate and inhibit NHE3, respectively, in both wild-type and Lpar5ΔIEC mice. The current study for the first time demonstrates the necessity of LPA5 in LPA-mediated stimulation of NHE3 in vivo. NEW & NOTEWORTHY This study is the first to assess the role of LPA5 in NHE3 regulation and fluid absorption in vivo using a mouse that lacks LPA5 in intestinal epithelial cells, Lpar5ΔIEC. Basal rates of NHE3 activity and fluid absorption, and total NHE3 expression were not changed in Lpar5ΔIEC mice. However, LPA did not activate NHE3 activity or fluid absorption in Lpar5ΔIEC mice, providing direct evidence for the regulatory role of LPA5.

Comparison of intestinal folate carrier clone expressed in IEC-6 cells and in Xenopusoocytes

1998 ◽  
Vol 274 (1) ◽  
pp. C289-C294 ◽  
Author(s):  
Chandira K. Kumar ◽  
Toai T. Nguyen ◽  
Francis B. Gonzales ◽  
Hamid M. Said
Keyword(s):  
Folic Acid ◽  
Epithelial Cells ◽  
Cdna Clone ◽  
Xenopus Oocytes ◽  
Intestinal Epithelial Cells ◽  
Maximal Velocity ◽  
Mrna Levels ◽  
Acidic Ph ◽  
Intestinal Epithelial ◽  
Folate Transport

We recently identified a cDNA clone from mouse small intestine, which appears to be involved in folate transport when expressed in Xenopus oocytes. The open reading frame of this clone is identical to that of the reduced folate carrier (RFC) (K. H. Dixon, B. C. Lanpher, J. Chiu, K. Kelley, and K. H. Cowan. J. Biol. Chem. 269: 17–20, 1994). The characteristics of this cDNA clone [previously referred to as intestinal folate carrier 1 (IFC-1)] expressed in Xenopus oocytes, however, were found to be different from the characteristics of folate transport in native small intestinal epithelial cells. To further study these differences, we determined the characteristics of RFC when expressed in an intestinal epithelial cell line, IEC-6, and compared the findings to its characteristics when expressed in Xenopus oocytes. RFC was stably transfected into IEC-6 cells by electroporation; its cRNA was microinjected into Xenopus oocytes. Northern blot analysis of poly(A)+RNA from IEC-6 cells stably transfected with RFC cDNA (IEC-6/RFC) showed a twofold increase in RFC mRNA levels over controls. Similarly, uptake of folic acid and 5-methyltetrahydrofolate (5-MTHF) by IEC-6/RFC was found to be fourfold higher than uptake in control sublines. This increase in folic acid and 5-MTHF uptake was inhibited by treating IEC-6/RFC cells with cholesterol-modified antisense DNA oligonucleotides. The increase in uptake was found to be mainly mediated through an increase in the maximal velocity ( V max) of the uptake process [the apparent Michaelis-Menten constant ( K m) also changed (range was 0.31 to 1.56 μM), but no specific trend was seen]. In both IEC-6/RFC and control sublines, the uptake of both folic acid and 5-MTHF displayed 1) pH dependency, with a higher uptake at acidic pH 5.5 compared with pH 7.5, and 2) inhibition to the same extent by both reduced and oxidized folate derivatives. These characteristics are very similar to those seen in native intestinal epithelial cells. In contrast, RFC expressed in Xenopus oocytes showed 1) higher uptake at neutral and alkaline pH 7.5 compared with acidic pH 5.5 and 2) higher sensitivity to reduced compared with oxidized folate derivatives. Results of these studies demonstrate that the characteristics of RFC vary depending on the cell system in which it is expressed. Furthermore, the results may suggest the involvement of cell- or tissue-specific posttranslational modification(s) and/or the existence of an auxiliary protein that may account for the differences in the characteristics of the intestinal RFC when expressed in Xenopus oocytes compared with when expressed in intestinal epithelial cells.

scholarly journals Mitochondrial gene expression in small intestinal epithelial cells

1995 ◽  
Vol 308 (2) ◽  
pp. 665-671 ◽  
Author(s):  
T P Mayall ◽  
I Bjarnason ◽  
U Y Khoo ◽  
T J Peters ◽  
A J S Macpherson
Keyword(s):  
Epithelial Cells ◽  
Cytochrome Oxidase ◽  
Cytochrome B ◽  
Intestinal Epithelial Cells ◽  
Mitochondrial Gene ◽  
Cytochrome Oxidase I ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Mitochondrial Transcription Factor ◽  
Small Intestinal

Most mitochondrial genes are transcribed as a single large transcript from the heavy strand of mitochondrial DNA, and are subsequently processed into the proximal mitochondrial (mt) 12 S and 16 S rRNAs, and the more distal tRNAs and mRNAs. We have shown that in intestinal epithelial biopsies the steady-state levels of mt 12 S and 16 S rRNA are an order of magnitude greater than those of mt mRNAs. Fractionation of rat small intestinal epithelial cells on the basis of their maturity has shown that the greatest ratios of 12 S mt rRNA/cytochrome b mt mRNA or 12 S mt rRNA/cytochrome oxidase I mt mRNA are found in the surface mature enterocytes, with a progressive decrease towards the crypt immature enteroblasts. Cytochrome b and cytochrome oxidase I mt mRNA levels are relatively uniform along the crypt-villus axis, but fractionation experiments showed increased levels in the crypt base. The levels of human mitochondrial transcription factor A are also greater in immature crypt enteroblasts compared with mature villus enterocytes. These results show that the relative levels of mt rRNA and mRNA are distinctly regulated in intestinal epithelial cells according to the crypt-villus position and differentiation status of the cells, and that there are higher mt mRNA and mt TFA levels in the crypts, consistent with increased transcriptional activity during mitochondrial biogenesis in the immature enteroblasts.

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