scholarly journals Crosstalk Between Nuclear Glucose-Regulated Protein 78 and Tumor Protein 53 Contributes to the Lipopolysaccharide Aggravated Apoptosis of Endoplasmic Reticulum Stress-Responsive Porcine Intestinal Epithelial Cells

2018 ◽  
Vol 48 (6) ◽  
pp. 2441-2455 ◽  
Author(s):  
Qian Jiang ◽  
Gang Liu ◽  
Jiashun Chen ◽  
Kang Yao ◽  
Yulong Yin

Background/Aims: Lipopolysaccharides (LPSs) act as virulence factors that trigger intestinal inflammation and thereby compromise the production of pigs worldwide. Intestinal diseases and dysfunction have been attributed to endoplasmic reticulum stress (ERS) and the subsequent apoptosis of intestinal epithelial cells. Therefore It is important to explore whether LPSs aggravate ERS-mediated apoptosis of intestinal epithelial cells. Methods: ERS and inflammation models were established in porcine cell line J2 (IPEC-J2) and the cells were treated with tunicamycin or LPS at specific times. The expression of marker proteins was determined by western blot and immunofluorescence. Possible crosstalk between proteins was analyzed by co-immunoprecipitation. Small interfering RNA transfection was employed to verify the mechanisms. Results: We found that Escherichia coli-derived LPS aggravated ERS and ERS-mediated apoptosis in ERS-responsive IPEC-J2 cells. The crosstalk between nuclear glucose-regulated protein 78 (GRP78) and tumor protein 53 (p53) was verified to trigger this LPS-aggravated apoptosis of ERS-responsive intestinal cells. Conclusion: This novel finding implies that intestinal malfunctions might solely originate from the effects of Gram-negative bacteria on ERS-responsive intestinal cells. The regulation of ERS signaling (especially the crosstalk between nuclear GRP78 and p53) in ERS-responsive/rapidly growing intestines may help intestinal cells survive from Gram-negative bacterial infections.

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Shen Yan ◽  
Liu Yingchao ◽  
Wang Zhangliu ◽  
Ruan Xianli ◽  
Li Si ◽  
...  

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.


2020 ◽  
Vol 11 ◽  
Author(s):  
Sanchez Preethi Eugene ◽  
Vadde Sudhakar Reddy ◽  
Jamma Trinath

The intestinal tract encompasses the largest mucosal surface fortified with a fine layer of intestinal epithelial cells along with highly sophisticated network of the lamina propria immune cells that are indispensable to sustain gut homeostasis. However, it can be challenging to uphold homeostasis when these cells in the intestine are perpetually exposed to insults of both endogenous and exogenous origin. The complex networking and dynamic microenvironment in the intestine demand highly functional cells ultimately burdening the endoplasmic reticulum (ER) leading to ER stress. Unresolved ER stress is one of the primary contributors to the pathogenesis of inflammatory bowel diseases (IBD). Studies also suggest that ER stress can be the primary cause of inflammation and/or the consequence of inflammation. Therefore, understanding the patterns of expression of ER stress regulators and deciphering the intricate interplay between ER stress and inflammatory pathways in intestinal epithelial cells in association with lamina propria immune cells contribute toward the development of novel therapies to tackle IBD. This review provides imperative insights into the molecular markers involved in the pathogenesis of IBD by potentiating ER stress and inflammation and briefly describes the potential pharmacological intervention strategies to mitigate ER stress and IBD. In addition, genetic mutations in the biomarkers contributing to abnormalities in the ER stress signaling pathways further emphasizes the relevance of biomarkers in potential treatment for IBD.


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