scholarly journals Deficiency in the anti-apoptotic protein DJ-1 promotes intestinal epithelial cell apoptosis and aggravates inflammatory bowel disease via p53

2020 ◽  
Vol 295 (13) ◽  
pp. 4237-4251 ◽  
Author(s):  
Jie Zhang ◽  
Min Xu ◽  
Weihua Zhou ◽  
Dejian Li ◽  
Hong Zhang ◽  
...  

Parkinson disease autosomal recessive, early onset 7 (PARK7 or DJ-1) is involved in multiple physiological processes and exerts anti-apoptotic effects on multiple cell types. Increased intestinal epithelial cell (IEC) apoptosis and excessive activation of the p53 signaling pathway is a hallmark of inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). However, whether DJ-1 plays a role in colitis is unclear. To determine whether DJ-1 deficiency is involved in the p53 activation that results in IEC apoptosis in colitis, here we performed immunostaining, real-time PCR, and immunoblotting analyses to assess DJ-1 expression in human UC and CD samples. In the inflamed intestines of individuals with IBD, DJ-1 expression was decreased and negatively correlated with p53 expression. DJ-1 deficiency significantly aggravated colitis, evidenced by increased intestinal inflammation and exacerbated IEC apoptosis. Moreover, DJ-1 directly interacted with p53, and reduced DJ-1 levels increased p53 levels both in vivo and in vitro and were associated with decreased p53 degradation via the lysosomal pathway. We also induced experimental colitis with dextran sulfate sodium in mice and found that compared with DJ-1−/− mice, DJ-1−/−p53−/− mice have reduced apoptosis and inflammation and increased epithelial barrier integrity. Furthermore, pharmacological inhibition of p53 relieved inflammation in the DJ-1−/− mice. In conclusion, reduced DJ-1 expression promotes inflammation and IEC apoptosis via p53 in colitis, suggesting that the modulation of DJ-1 expression may be a potential therapeutic strategy for managing colitis.

Physiology ◽  
2018 ◽  
Vol 33 (5) ◽  
pp. 360-369 ◽  
Author(s):  
Gabriella Leung ◽  
Aleixo M. Muise

The incidence of inflammatory bowel disease (IBD) is increasing worldwide, most notably in young children. The development of disease is a combination of several factors, including genetics, environment, the microbiota, and immune system. Recently, next-generation sequencing has allowed for the identification of novel genetic causes for intestinal disease, including pediatric inflammatory bowel disease (IBD). These IBD genes can generally be grouped into genes causing either primary immunodeficiency or intestinal epithelial defects (the focus of this review). Most of these genes have been functionally validated with in vitro and/or animal models, and have been demonstrated to cause intestinal disease. Intestinal epithelial IBD genes are of particular interest since they are the least amenable to current therapies; therefore, further research is warranted to develop potential therapies. A number of cellular pathways are impacted with intestinal epithelial IBD genes, including intestinal epithelial cell adhesion and generation of reactive oxygen species. Here, we describe the currently known IBD risk alleles and monogenic causal intestinal epithelial genes, their putative roles in preserving intestinal epithelial cell homeostasis, and their implications for IBD pathophysiology.


2000 ◽  
Vol 68 (12) ◽  
pp. 7010-7017 ◽  
Author(s):  
Elke Cario ◽  
Daniel K. Podolsky

ABSTRACT Initiation and perpetuation of the inflammatory intestinal responses in inflammatory bowel disease (IBD) may result from an exaggerated host defense reaction of the intestinal epithelium to endogenous lumenal bacterial flora. Intestinal epithelial cell lines constitutively express several functional Toll-like receptors (TLRs) which appear to be key regulators of the innate response system. The aim of this study was to characterize the expression pattern of TLR2, TLR3, TLR4, and TLR5 in primary intestinal epithelial cells from patients with IBD. Small intestinal and colonic biopsy specimens were collected from patients with IBD (Crohn's disease [CD], ulcerative colitis [UC]) and controls. Non-IBD specimens were assessed by immunofluorescence histochemistry using polyclonal antibodies specific for TLR2, TLR3, TLR4, and TLR5. Primary intestinal epithelial cells (IEC) of normal mucosa constitutively expressed TLR3 and TLR5, while TLR2 and TLR4 were only barely detectable. In active IBD, the expression of TLR3 and TLR4 was differentially modulated in the intestinal epithelium. TLR3 was significantly downregulated in IEC in active CD but not in UC. In contrast, TLR4 was strongly upregulated in both UC and CD. TLR2 and TLR5 expression remained unchanged in IBD. These data suggest that IBD may be associated with distinctive changes in selective TLR expression in the intestinal epithelium, implying that alterations in the innate response system may contribute to the pathogenesis of these disorders.


2020 ◽  
Vol 26 (12) ◽  
pp. 1856-1868
Author(s):  
Stefanie Derer ◽  
Ann-Kathrin Brethack ◽  
Carlotta Pietsch ◽  
Sebastian T Jendrek ◽  
Thomas Nitzsche ◽  
...  

Abstract Adherent-invasive Escherichia coli have been suggested to play a pivotal role within the pathophysiology of inflammatory bowel disease (IBD). Autoantibodies against distinct splicing variants of glycoprotein 2 (GP2), an intestinal receptor of the bacterial adhesin FimH, frequently occur in IBD patients. Hence, we aimed to functionally characterize GP2-directed autoantibodies as a putative part of IBD’s pathophysiology. Ex vivo, GP2-splicing variant 4 (GP2#4) but not variant 2 was expressed on intestinal M or L cells with elevated expression patterns in IBD patients. The GP2#4 expression was induced in vitro by tumor necrosis factor (TNF)-α. The IBD-associated GP2 autoantibodies inhibited FimH binding to GP2#4 and were decreased in anti-TNFα-treated Crohn’s disease patients with ileocolonic disease manifestation. In vivo, mice immunized against GP2 before infection with adherent-invasive bacteria displayed exacerbated intestinal inflammation. In summary, autoimmunity against intestinal expressed GP2#4 results in enhanced attachment of flagellated bacteria to the intestinal epithelium and thereby may drive IBD’s pathophysiology.


2018 ◽  
Vol 215 (7) ◽  
pp. 1839-1852 ◽  
Author(s):  
Michael G. Kattah ◽  
Ling Shao ◽  
Yenny Y. Rosli ◽  
Hiromichi Shimizu ◽  
Michael I. Whang ◽  
...  

A20 (TNFAIP3) and ABIN-1 (TNIP1) are candidate susceptibility genes for inflammatory bowel disease and other autoimmune or inflammatory diseases, but it is unclear how these proteins interact in vivo to prevent disease. Here we show that intestinal epithelial cell (IEC)-specific deletion of either A20 or ABIN-1 alone leads to negligible IEC loss, whereas simultaneous deletion of both A20 and ABIN-1 leads to rapid IEC death and mouse lethality. Deletion of both A20 and ABIN-1 from enteroids causes spontaneous cell death in the absence of microbes or hematopoietic cells. Studies with enteroids reveal that A20 and ABIN-1 synergistically restrict death by inhibiting TNF-induced caspase 8 activation and RIPK1 kinase activity. Inhibition of RIPK1 kinase activity alone, or caspase inhibition combined with RIPK3 deletion, abrogates IEC death by blocking both apoptosis and necroptosis in A20 and ABIN-1 double-deficient cells. These data show that the disease susceptibility proteins A20 and ABIN-1 synergistically prevent intestinal inflammation by restricting IEC death and preserving tissue integrity.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Katherine Luo ◽  
Stewart Siyan Cao

In eukaryotic cells, perturbation of protein folding homeostasis in the endoplasmic reticulum (ER) causes accumulation of unfolded and misfolded proteins in the ER lumen, which activates intracellular signaling pathways termed the unfolded protein response (UPR). Recent studies have linked ER stress and the UPR to inflammatory bowel disease (IBD). The microenvironment of the ER is affected by a myriad of intestinal luminal molecules, implicating ER stress and the UPR in proper maintenance of intestinal homeostasis. Several intestinal cell populations, including Paneth and goblet cells, require robust ER function for protein folding, maturation, and secretion. Prolonged ER stress and impaired UPR signaling may cause IBD through: (1) induction of intestinal epithelial cell apoptosis, (2) disruption of mucosal barrier function, and (3) induction of the proinflammatory response in the gut. Based on our increased understanding of ER stress in IBD, new pharmacological approaches can be developed to improve intestinal homeostasis by targeting ER protein-folding in the intestinal epithelial cells (IECs).


Gut ◽  
1999 ◽  
Vol 44 (5) ◽  
pp. 629-635 ◽  
Author(s):  
J Wedemeyer ◽  
A Lorentz ◽  
M Göke ◽  
P N Meier ◽  
P Flemming ◽  
...  

BACKGROUNDThe β chemokine monocyte chemotactic protein 3 (MCP-3) has chemoattractant and activating capabilities in monocytes, lymphocytes, eosinophils, and basophils.AIMSTo investigate MCP-3 expression in inflammatory conditions of the human intestinal mucosa.PATIENTSForty five colon biopsy specimens from 18 patients with inflammatory bowel disease (IBD; 16 specimens from inflamed and 10 from non-inflamed areas) and 19 control patients were examined.METHODSImmunohistochemical staining and reverse transcription polymerase chain reaction (RT-PCR) were used for MCP-3 detection in tissue sections. Intestinal epithelial cell lines (HT-29, Caco-2, T-84) were stimulated with interleukin (IL) 1β, IL-6, and tumour necrosis factor α (TNF-α) and examined for MCP-3 protein and mRNA expression using immunocytochemistry and RT-PCR, respectively.RESULTSIn tissue sections, MCP-3 protein was detected predominantly in epithelial cells, both in patients with IBD and in controls. MCP-3 staining was particularly pronounced at sites of active mucosal inflammation. The intensity of MCP-3 staining was positively correlated with the extent of epithelial destruction. In intestinal epithelial cell lines, MCP-3 mRNA was expressed, whereas MCP-3 protein was not consistently detected.CONCLUSIONSOur data show that MCP-3 protein is present in normal and inflamed intestinal tissue. MCP-3 production is substantially enhanced in areas of active inflammation, suggesting an immunoregulatory role of MCP-3 in intestinal inflammation.


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