scholarly journals Akt Kinase Activation Blocks Apoptosis in Intestinal Epithelial Cells by Inhibiting Caspase-3 after Polyamine Depletion

2004 ◽  
Vol 279 (21) ◽  
pp. 22539-22547 ◽  
Author(s):  
Huifang M. Zhang ◽  
Jaladanki N. Rao ◽  
Xin Guo ◽  
Lan Liu ◽  
Tongtong Zou ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Akt Kinase ◽  
Kinase Activation

LPA protects intestinal epithelial cells from apoptosis by inhibiting the mitochondrial pathway

2003 ◽  
Vol 284 (5) ◽  
pp. G821-G829 ◽  
Author(s):  
Wenlin Deng ◽  
De-An Wang ◽  
Elvira Gosmanova ◽  
Leonard R. Johnson ◽  
Gabor Tigyi
Keyword(s):  
Epithelial Cells ◽  
Cytochrome C ◽  
Protein Expression ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Antiapoptotic Activity

We previously showed ( Gastroenterology 123: 206–216, 2002) that lysophosphatidic acid (LPA) protects and rescues rat intestinal epithelial cells (IEC-6) from apoptosis. Here, we provide evidence for the LPA-elicited inhibition of the mitochondrial apoptotic pathway leading to attenuation of caspase-3 activation. Pretreatment of IEC-6 cells with LPA inhibited campothecin-induced caspase-9 and caspase-3 activation and DNA fragmentation. A caspase-9 inhibitor peptide mimicked the LPA-elicited antiapoptotic activity. LPA elicited ERK1/ERK2 and PKB/Akt phosphorylation. The LPA-elicited antiapoptotic activity and inhibition of caspase-9 activity were abrogated by pertussis toxin, PD 98059, wortmannin, and LY 294002. LPA reduced cytochrome c release from mitochondria and prevented activation of caspase-9. LPA prevented translocation of Bax from cytosol to mitochondria and increased the expression of the antiapoptotic Bcl-2 mRNA and protein. LPA had no effect on Bcl-xl, Bad, and Bak mRNA or protein expression. These data indicate that LPA protects IEC-6 cells from camptothecin-induced apoptosis through Gi-coupled inhibition of caspase-3 activation mediated by the attenuation of caspase-9 activation due to diminished cytochrome c release, involving upregulation of Bcl-2 protein expression and prevention of Bax translocation.

scholarly journals Effect of Berberine from Coptis chinensis on Apoptosis of Intestinal Epithelial Cells in a Mouse Model of Ulcerative Colitis: Role of Endoplasmic Reticulum Stress

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Shen Yan ◽  
Liu Yingchao ◽  
Wang Zhangliu ◽  
Ruan Xianli ◽  
Li Si ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Endoplasmic Reticulum Stress ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
High Dose ◽  
Intestinal Epithelial ◽  
Model Group ◽  
Caspase 12

The purpose of this study was to verify the effect of berberine (BBR) on endoplasmic reticulum stress (ERS) and apoptosis of intestinal epithelial cells (IECs) in mice with ulcerative colitis (UC). BALB/c mice were randomly divided into five groups as follows: blank control, model, and low-, medium-, and high-dose BBR. A dextran sodium sulfate- (DSS-) induced model of UC was prepared, and the low-, medium-, and high-dose BBR groups were simultaneously gavaged with a BBR suspension for 7 d. Disease activity index (DAI) was assessed, and tissue damage index (TDI) was assessed from colon samples after the last administration. TUNEL assays were used to detect apoptosis of IECs. Immunohistochemistry and/or real-time PCR were applied to determine the expression of GRP78, caspase-12, and caspase-3. In all BBR treatment groups, clinical symptoms of colitis and histopathological damage were significantly reduced. The high-dose BBR group exhibited particularly pronounced decrease (p<0.01) in both DAI (0.48 ± 0.36) and TDI (1.62 ± 0.64) relative to the model group (1.50 ± 0.65 and 3.88 ± 0.04, respectively). In colon tissues of the model group, the number of apoptotic IECs was significantly increased; the expression of GRP78, caspase-12, and caspase-3 proteins was significantly increased; and the expression of the GRP78 mRNA was upregulated. In low-, medium-, and high-dose BBR groups, the number of apoptotic IECs was significantly reduced. Moreover, GRP78 and caspase-3 expression levels were significantly decreased in the medium- and high-dose BBR groups, caspase-12 expression was significantly decreased in the high-dose BBR group, and the GRP78 mRNA expression level was significantly decreased in the high-dose BBR group. BBR can effectively reduce the rate of IEC apoptosis in UC mice and alleviate the inflammatory response in the colon. The underlying mechanism seems to involve ERS modulation and inhibition of ERS-mediated activation of the caspase-12/caspase-3 apoptosis signaling pathway.

scholarly journals Brain-Derived Neurotrophic Factor Modulates Intestinal Barrier by Inhibiting Intestinal Epithelial Cells Apoptosis in Mice

2018 ◽  
pp. 475-485 ◽  
Author(s):  
D.-Y. ZHAO ◽  
W.-X. ZHANG ◽  
Q.-Q. QI ◽  
X. LONG ◽  
X. LI ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Colonic Mucosa ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Intestinal Barrier ◽  
Intestinal Epithelial ◽  
Tight Junction Proteins ◽  
Intestinal Barrier Integrity ◽  
Junction Proteins ◽  
Active Caspase

We aimed to investigate the effects of brain-derived neurotrophic factor (BDNF) on apoptosis of intestinal epithelial cells (IECs) and alterations of intestinal barrier integrity using BDNF knock-out mice model. Colonic tissues from BDNF+/+ mice and BDNF+/- mice were prepared for this study. The integrity of colonic mucosa was evaluated by measuring trans-mucosa electrical resistance and tissue conductance in Ussing chamber. The colonic epithelial structure was analyzed by transmission electron microscopy. Apoptosis involvement was determined with TUNEL staining, active caspase-3 immunostaining and Western blotting for the protein expression of active caspase-3, Bax and Bcl-2. The expression levels and distribution of tight junction proteins were evaluated by immunohistochemistry or Western blots. Compared with BDNF+/+ mice, BDNF+/- mice displayed impaired integrity and ultrastructure alterations in their colonic mucosa, which was characterized by diminished microvilli, mitochondrial swelling and epithelial cells apoptosis. Altered intestinal barrier function was linked to excessive apoptosis of IECs demonstrated by the higher proportion of TUNEL-positive apoptotic cells and enhanced caspase activities in BDNF+/- mice. Increased expression of Bax and claudin-2 proteins and reduced Bcl-2 and tight junction proteins (occludin, ZO-1 and claudin-1) expression were also detected in the colonic mucosa of BDNF+/- mice. BDNF may play a role in the maintenance of intestinal barrier integrity via its anti-apoptotic properties.

scholarly journals Platelet-activating factor-induced apoptosis is blocked by Bcl-2 in rat intestinal epithelial cells

2004 ◽  
Vol 286 (2) ◽  
pp. G340-G350 ◽  
Author(s):  
Jing Lu ◽  
Michael S. Caplan ◽  
Anita P. Saraf ◽  
Dan Li ◽  
Luba Adler ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Epithelial Cells ◽  
Dna Fragmentation ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Regulatory Gene ◽  
Mucosal Injury ◽  
Intestinal Epithelial

Plateletactivating factor (PAF) is a key mediator in pathogenesis of inflammatory bowel diseases (IBDs) but mechanisms of PAF-induced mucosal injury are poorly understood. To determine whether apoptosis and the Bcl-2-family of apoptosis regulatory gene products play a role in PAF-induced mucosal injury, we stably and conditionally overexpressed bcl-2 in rat small intestinal epithelial cells-6 under the control of a lactose-inducible promoter. Western blot analysis and immuno-histochemistry were used to verify inducible Bcl-2 and to analyze Bcl-2 and a proapoptotic member of the Bcl-2 family, Bax, subcellular distribution. DNA fragmentation was quantified by ELISA, caspase activity was measured by using fluorogenic peptide substrates, and mitochondrial membrane potential was assayed by 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) and fluorescence digital imaging. Bcl-2 expression was highly inducible by lactose analog isopropyl-β-d-thiogalactoside (IPTG) and was localized predominantly to mitochondria. In the absence of bcl-2 overexpression and after treatment with PAF, Bax translocated to mitochondria, and mitochondrial membrane potential collapsed within 1 h, followed by caspase-3 activation, which peaked at 6 h with an ensuing DNA fragmentation maximizing at 18 h. After IPTG-induction of bcl-2 expression, PAF failed to induce DNA fragmentation, caspase-3 activation, Bax translocation, or a collapse of mitochondrial membrane potential. These data are the first to show that PAF can activate apoptotic machinery in enterocytes via a mechanism involving Bax translocation and collapse of mitochondrial membrane potential and that both of these events are under control by bcl-2 expression levels. A better understanding of the role of PAF and Bcl-2 family of apoptosis regulators in epithelial cell death might aid design of better therapeutic or preventive strategies for IBDs.

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.

NF-κB-mediated IAP expression induces resistance of intestinal epithelial cells to apoptosis after polyamine depletion

2004 ◽  
Vol 286 (5) ◽  
pp. C1009-C1018 ◽  
Author(s):  
Tongtong Zou ◽  
Jaladanki N. Rao ◽  
Xin Guo ◽  
Lan Liu ◽  
Huifang M. Zhang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
Intestinal Epithelial ◽  
Tnf Α ◽  
Induced Apoptosis ◽  
Necrosis Factor ◽  
Active Caspase

Apoptosis plays a crucial role in maintenance of intestinal epithelial integrity and is highly regulated by numerous factors, including cellular polyamines. We recently showed that polyamines regulate nuclear factor (NF)-κB activity in normal intestinal epithelial (IEC-6) cells and that polyamine depletion activates NF-κB and promotes resistance to apoptosis. The current study went further to determine whether the inhibitors of apoptosis (IAP) family of proteins, c-IAP2 and XIAP, are downstream targets of activated NF-κB and play a role in antiapoptotic activity of polyamine depletion in IEC-6 cells. Depletion of cellular polyamines by α-difluoromethylornithine not only activated NF-κB activity but also increased expression of c-IAP2 and XIAP. Specific inhibition of NF-κB by the recombinant adenoviral vector containing IκBα superrepressor (Ad Iκ BSR) prevented the induction of c-IAP2 and XIAP in polyamine-deficient cells. Decreased levels of c-IAP2 and XIAP proteins by inactivation of NF-κB through Ad Iκ BSR infection or treatment with the specific inhibitor Smac also overcame the resistance of polyamine-depleted cells to apoptosis induced by the combination of tumor necrosis factor (TNF)-α and cycloheximide (CHX). Although polyamine depletion did not alter levels of procaspase-3 protein, it inhibited formation of the active caspase-3. Decreased levels of c-IAP2 and XIAP by Smac prevented the inhibitory effect of polyamine depletion on the cleavage of procaspase-3 to the active caspase-3. These results indicate that polyamine depletion increases expression of c-IAP2 and XIAP by activating NF-κB in intestinal epithelial cells. Increased c-IAP2 and XIAP after polyamine depletion induce the resistance to TNF-α/CHX-induced apoptosis, at least partially, through inhibition of the caspase-3 activity.

scholarly journals Silencing of peroxiredoxin 1 expression ameliorates ulcerative colitis in a rat model

2021 ◽  
Vol 49 (3) ◽  
pp. 030006052098631
Author(s):  
Na Wu ◽  
Xinchong Du ◽  
Zhao Peng ◽  
Zetian Zhang ◽  
Lijun Cui ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Epithelial Cells ◽  
Western Blotting ◽  
Inflammatory Cytokines ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Colon Injury ◽  
Peroxiredoxin 1 ◽  
Tnf Α

Background Peroxiredoxin 1 (PRDX1), a protein with anti-inflammatory and anti-apoptotic properties, shows elevated expression in ulcerative colitis (UC). However, PRDX1's specific role in UC is poorly understood. Methods UC was induced in rats using dextran sulfate sodium (DSS). In vivo RNA interference was used to silence the PRDX1 expression. PRDX1 expression levels and the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β and interferon (IFN)-γ in tissues were assessed by real-time quantitative polymerase chain reaction and western blotting. Colonic injury was assessed by hematoxylin–eosin staining. ELISA was used to assess levels of the inflammatory cytokines TNF-α, IL-1β and IL-6 in colon tissues. Apoptosis of intestinal epithelial cells was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling, and expression of the apoptotic proteins bcl-2, Bax, cleaved caspase-3 and caspase-3 was assessed by western blotting. Results PRDX1 expression was significantly increased in rats with DSS-induced UC. Silencing of PRDX1 expression improved colon injury in rats with DSS-induced UC. In addition, silencing of PRDX1 expression inhibited inflammatory responses and apoptosis of intestinal epithelial cells in rats with DSS-induced UC. Conclusions Silencing of PRDX1 expression can ameliorate colon injury in rats with DSS-induced UC.

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