Endoplasmic reticulum stress and unfolded protein response are involved in paediatric inflammatory bowel disease

2014 ◽  
Vol 46 (9) ◽  
pp. 788-794 ◽  
Author(s):  
Anna Negroni ◽  
Enrica Prete ◽  
Roberta Vitali ◽  
Vincenzo Cesi ◽  
Marina Aloi ◽  
...  
2019 ◽  
Vol 25 (9) ◽  
pp. 1481-1496 ◽  
Author(s):  
Kirsty M Hooper ◽  
Victor Casanova ◽  
Sadie Kemp ◽  
Katherine A Staines ◽  
Jack Satsangi ◽  
...  

Abstract Background Genetic studies have strongly linked autophagy to Crohn’s disease (CD), and stimulating autophagy in CD patients may be therapeutically beneficial. The aim of this study was to evaluate the effect of current inflammatory bowel disease (IBD) drugs on autophagy and investigate molecular mechanisms of action and functional outcomes in relation to this cellular process. Methods Autophagy marker LC3 was evaluated by confocal fluorescence microscopy and flow cytometry. Drug mechanism of action was investigated by polymerase chain reaction (PCR) array with changes in signaling pathways examined by immunoblot and quantitative reverse transcription PCR (RT-qPCR). Clearance of adherent-invasive Escherichia coli (AIEC) and levels of pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) were evaluated by gentamicin protection assays and RT-qPCR, respectively. The marker LC3 was analyzed in peripheral blood mononuclear cells (PBMCs) from pediatric patients by flow cytometry. Results Azathioprine induces autophagy via mechanisms involving modulation of mechanistic target of rapamycin (mTORC1) signaling and stimulation of the unfolded protein response (UPR) sensor PERK. Induction of autophagy with azathioprine correlated with the enhanced clearance of AIEC and dampened AIEC-induced increases in TNFα. Azathioprine induced significant increase in autophagosome bound LC3-II in PBMC populations ex vivo, supporting in vitro findings. In patients, the CD-associated ATG16L1 T300A single-nucleotide polymorphism did not attenuate azathioprine induction of autophagy. Conclusions Modulation of autophagy via mTORC1 and the UPR may contribute to the therapeutic efficacy of azathioprine in IBD.


2013 ◽  
Vol 144 (5) ◽  
pp. S-470 ◽  
Author(s):  
Orazio Palmieri ◽  
Teresa M. Creanza ◽  
Giuseppe Corritore ◽  
Tiziana Latiano ◽  
Nello Buccianti ◽  
...  

2011 ◽  
Vol 441 (1) ◽  
pp. 87-93 ◽  
Author(s):  
J. Jasper Deuring ◽  
Colin de Haar ◽  
Chantal L. Koelewijn ◽  
Ernst J. Kuipers ◽  
Maikel P. Peppelenbosch ◽  
...  

Xenotoxic damage in inflammatory diseases, including IBD (inflammatory bowel disease), is compounded by reduced activity of the xenobiotic transporter ABCG2 (ATP-binding-cassette G2) during the inflammatory state. An association between the activation of the unfolded protein response pathway and inflammation prompted us to investigate the possibility that reduced ABCG2 activity is causally linked to this response. To this end, we correlated expression of ABCG2 and the unfolded protein response marker GRP78 (glucose-regulated protein of 78 kDa) in colon biopsies from healthy individuals (n=9) and patients with inactive (n=67) or active (n=55) IBD, ischaemic colitis (n=10) or infectious colitis (n=14). In addition, tissue specimens throughout the small bowel from healthy individuals (n=27) and from patients with inactive (n=9) or active (n=25) Crohn's disease were co-stained for ABCG2 and GRP78. In all biopsies from patients with active inflammation, irrespective of the underlying disease, an absolute negative correlation was observed between epithelial ABCG2 expression and GRP78 expression, suggesting that inflammation-dependent activation of the unfolded protein response is responsible for suppression of ABCG2 function. The link between the unfolded protein response and functional ABCG2 expression was further corroborated by live imaging of ABCG2-expressing cells, which showed that various inflammatory mediators, including nitric oxide, activate the unfolded protein response and concomitantly reduce plasma membrane localization as well as transport function of ABCG2. Thus a novel mechanism for explaining xenobiotic stress during inflammation emerges in which intestinal inflammation activates the unfolded protein response, in turn abrogating defences against xenobiotic challenge by impairing ABCG2 expression and function.


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