Colitis Linked to Endoplasmic Reticulum Stress Induces Trypsin Activity Affecting Epithelial Functions

Author(s):  
Núria Solà Tapias ◽  
Alexandre Denadai-Souza ◽  
Claire Rolland-Fourcade ◽  
Muriel Quaranta-Nicaise ◽  
Catherine Blanpied ◽  
...  

Abstract Background and Aims Intestinal epithelial cells [IECs] from inflammatory bowel disease [IBD] patients exhibit an excessive induction of endoplasmic reticulum stress [ER stress] linked to altered intestinal barrier function and inflammation. Colonic tissues and the luminal content of IBD patients are also characterized by increased serine protease activity. The possible link between ER stress and serine protease activity in colitis-associated epithelial dysfunctions is unknown. We aimed to study the association between ER stress and serine protease activity in enterocytes and its impact on intestinal functions Methods The impact of ER stress induced by Thapsigargin on serine protease secretion was studied using either human intestinal cell lines or organoids. Moreover, treating human intestinal cells with protease-activated receptor antagonists allowed us to investigate ER stress-resulting molecular mechanisms that induce proteolytic activity and alter intestinal epithelial cell biology. Results Colonic biopsies from IBD patients exhibited increased epithelial trypsin-like activity associated with elevated ER stress. Induction of ER stress in human intestinal epithelial cells displayed enhanced apical trypsin-like activity. ER stress-induced increased trypsin activity destabilized intestinal barrier function by increasing permeability and by controlling inflammatory mediators such as C-X-C chemokine ligand 8 [CXCL8]. The deleterious impact of ER stress-associated trypsin activity was specifically dependent on the activation of protease-activated receptors 2 and 4. Conclusions Excessive ER stress in IECs caused an increased release of trypsin activity that, in turn, altered intestinal barrier function, promoting the development of inflammatory process.

2020 ◽  
Vol 159 (5) ◽  
pp. 1763-1777.e14 ◽  
Author(s):  
Marianne R. Spalinger ◽  
Anica Sayoc-Becerra ◽  
Alina N. Santos ◽  
Ali Shawki ◽  
Vinicius Canale ◽  
...  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 109-110
Author(s):  
Lauren L Kovanda ◽  
Monika Hejna ◽  
Yanhong Liu

Abstract Intestinal barrier function in vitro is quantified by the transepithelial electrical resistance (TEER) across epithelial cell monolayers due to polarization and expression of tight junction proteins. The objective of the current study was to measure the TEER of porcine intestinal epithelial cells (IPEC-J2) treated with butyric acid, sodium butyrate, monobutyrin and tributyrin. MTT assays were performed for each compound to determine cell viability and appropriate treatment doses. Butyric acid and tributyrin treatments were: 0, 0.5, 1, 2, and 4 mM. Monobutyrin and sodium butyrate doses were: 0, 1, 2, 4, 8 mM. Cells were seeded at 5 × 105 cells/mL into 12-well plates on Corning transwell inserts. Cells were cultured for 4 to 5 days (until all wells had TEER close to 1000 Ωcm2) and were then treated with organic acids. Each compound was tested in a randomized complete block design with 10 replicates. TEER was measured in Ωcm2 using a Millicell ERS-2 voltohmmeter at 0 h (before treatment) and at 24, 48, and 72 h post-treatment. All data were analyzed by PROC MIXED of SAS. Butyric acid linearly enhanced (P < 0.001) TEER of IPEC-J2 dose-dependently, with the highest TEER observed at doses of 1 and 2 mM at each time point. Sodium butyrate did not impact TEER at h 24, but linearly increased (P < 0.05) TEER at h 48 and 72. Treatment of monobutyrin linearly improved (P < 0.001) TEER at h 24, 48, and 72, with the highest TEER observed at the dose of 8 mM. Tributyrin had the tendency to improve (P < 0.10) TEER at h 48 and 72 when the highest dose was applied. Results of the current in vitro study indicate that butyric acid and its derivatives may improve intestinal barrier function of pigs, which requires verification in vivo.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Danyang Zheng ◽  
Henan Zhou ◽  
Hongchen Wang ◽  
Yu Zhu ◽  
Yue Wu ◽  
...  

Abstract Background Sepsis is a major cause of death in ICU, and intestinal barrier dysfunction is its important complication, while the treatment is limited. Recently, mesenchymal stem cell-derived microvesicles (MMVs) attract much attention as a strategy of cell-free treatment; whether MMVs are therapeutic in sepsis induced-intestinal barrier dysfunction is obscure. Methods In this study, cecal ligation and puncture-induced sepsis rats and lipopolysaccharide-stimulated intestinal epithelial cells to investigate the effect of MMVs on intestinal barrier dysfunction. MMVs were harvested from mesenchymal stem cells and were injected into sepsis rats, and the intestinal barrier function was measured. Afterward, MMVs were incubated with intestinal epithelial cells, and the effect of MMVs on mitochondrial dynamic balance was measured. Then the expression of mfn1, mfn2, OPA1, and PGC-1α in MMVs were measured by western blot. By upregulation and downregulation of mfn2 and PGC-1α, the role of MMVs in mitochondrial dynamic balance was investigated. Finally, the role of MMV-carried mitochondria in mitochondrial dynamic balance was investigated. Results MMVs restored the intestinal barrier function by improving mitochondrial dynamic balance and metabolism of mitochondria. Further study revealed that MMVs delivered mfn2 and PGC-1α to intestinal epithelial cells, and promoted mitochondrial fusion and biogenesis, thereby improving mitochondrial dynamic balance. Furthermore, MMVs delivered functional mitochondria to intestinal epithelial cells and enhanced energy metabolism directly. Conclusion MMVs can deliver mfn2, PGC-1α, and functional mitochondria to intestinal epithelial cells, synergistically improve mitochondrial dynamic balance of target cells after sepsis, and restore the mitochondrial function and intestinal barrier function. The study illustrated that MMVs might be a promising strategy for the treatment of sepsis.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Jing Wang ◽  
Siddhartha S Ghosh ◽  
Shobha Ghosh

Association between circulating lipopolysaccharide (LPS) and metabolic diseases (such as Type 2 Diabetes and atherosclerosis) has shifted the focus from high fat high cholesterol containing western type diet (WD)-induced changes in gut microbiota per se to release of gut bacteria-derived products into circulation as the possible mechanism for the chronic inflammatory state underlying the development of these diseases. We demonstrated earlier that WD-induced changes in intestinal barrier function increases the release of LPS into systemic circulation and oral supplementation with curcumin not only reduces the levels of systemic LPS but also attenuates the subsequent development of glucose intolerance and atherosclerosis. Although curcumin is reported to exert potent anti-inflammatory effects in vitro , its poor bioavailability has raised doubts about a causal relationship between oral supplementation and the in vivo effects. It is hypothesized that curcumin attenuates WD-induced chronic inflammation and associated metabolic diseases by modulating the function of intestinal epithelial cells (IECs) and the objective of the present study was to delineate the underlying mechanisms. Human IEC lines, Caco-2, HT-29 and T-84 were used for these studies and modulation of direct as well as indirect effects of LPS on tight junctions as well as intracellular signaling were examined. Pre-treatment with Curcumin prevented LPS-induced disruption of tight junctions. LPS-induced secretion of master cytokine IL-1β was also dramatically reduced by pre-treatment with curcumin. Furthermore, curcumin also attenuated IL-1β induced activation of p-38 MAPK involved in the phosphorylation of tight junction proteins and subsequent disruption of their normal arrangement. Based on these data, the sites of curcumin actions leading to preservation of intestinal barrier function are shown in the Figure (activation and inhibition denoted by + and - symbols in green circles).


Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 187
Author(s):  
Lokman Pang ◽  
Jennifer Huynh ◽  
Mariah G. Alorro ◽  
Xia Li ◽  
Matthias Ernst ◽  
...  

The intestinal epithelium provides a barrier against commensal and pathogenic microorganisms. Barrier dysfunction promotes chronic inflammation, which can drive the pathogenesis of inflammatory bowel disease (IBD) and colorectal cancer (CRC). Although the Signal Transducer and Activator of Transcription-3 (STAT3) is overexpressed in both intestinal epithelial cells and immune cells in IBD patients, the role of the interleukin (IL)-6 family of cytokines through the shared IL-6ST/gp130 receptor and its associated STAT3 signalling in intestinal barrier integrity is unclear. We therefore investigated the role of STAT3 in retaining epithelial barrier integrity using dextran sulfate sodium (DSS)-induced colitis in two genetically modified mouse models, to either reduce STAT1/3 activation in response to IL-6 family cytokines with a truncated gp130∆STAT allele (GP130∆STAT/+), or by inducing short hairpin-mediated knockdown of Stat3 (shStat3). Here, we show that mice with reduced STAT3 activity are highly susceptible to DSS-induced colitis. Mechanistically, the IL-6/gp130/STAT3 signalling cascade orchestrates intestinal barrier function by modulating cytokine secretion and promoting epithelial integrity to maintain a defence against bacteria. Our study also identifies a crucial role of STAT3 in controlling intestinal permeability through tight junction proteins. Thus, therapeutically targeting the IL-6/gp130/STAT3 signalling axis to promote barrier function may serve as a treatment strategy for IBD patients.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hee Soon Shin ◽  
Sun Young Jung ◽  
Su Yeon Back ◽  
Jeong-Ryong Do ◽  
Dong-Hwa Shon

Fructus Arctiiis used as a traditional herbal medicine to treat inflammatory diseases in oriental countries. This study aimed to investigate effect ofF. Arctiiextract on intestinal barrier function in human intestinal epithelial Caco-2 cells and to reveal the active component ofF. Arctii. We measured transepithelial electrical resistance (TEER) value (as an index of barrier function) and ovalbumin (OVA) permeation (as an index of permeability) to observe the changes of intestinal barrier function. The treatment ofF. Arctiiincreased TEER value and decreased OVA influx on Caco-2 cell monolayers. Furthermore, we found that arctigenin as an active component ofF. Arctiiincreased TEER value and reduced permeability of OVA from apical to the basolateral side but not arctiin. In the present study, we revealed thatF. Arctiicould enhance intestinal barrier function, and its active component was an arctigenin on the functionality. We expect that the arctigenin fromF. Arctiicould contribute to prevention of inflammatory, allergic, and infectious diseases by reinforcing intestinal barrier function.


Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 67 ◽  
Author(s):  
Shara Francesca Rapa ◽  
Rosanna Di Paola ◽  
Marika Cordaro ◽  
Rosalba Siracusa ◽  
Ramona D’Amico ◽  
...  

Intestinal epithelial barrier impairment plays a key pathogenic role in inflammatory bowel diseases (IBDs). In particular, together with oxidative stress, intestinal epithelial barrier alteration is considered as upstream event in ulcerative colitis (UC). In order to identify new products of natural origin with a potential activity for UC treatment, this study evaluated the effects of plumericin, a spirolactone iridoid, present as one of the main bioactive components in the bark of Himatanthus sucuuba (Woodson). Plumericin was evaluated for its ability to improve barrier function and to reduce apoptotic parameters during inflammation, both in intestinal epithelial cells (IEC-6), and in an animal experimental model of 2, 4, 6-dinitrobenzene sulfonic acid (DNBS)-induced colitis. Our results indicated that plumericin increased the expression of adhesion molecules, enhanced IEC-6 cells actin cytoskeleton rearrangement, and promoted their motility. Moreover, plumericin reduced apoptotic parameters in IEC-6. These results were confirmed in vivo. Plumericin reduced the activity of myeloperoxidase, inhibited the expression of ICAM-1, P-selectin, and the formation of PAR, and reduced apoptosis parameters in mice colitis induced by DNBS. These results support a pharmacological potential of plumericin in the treatment of UC, due to its ability to improve the structural integrity of the intestinal epithelium and its barrier function.


2020 ◽  
Vol 295 (25) ◽  
pp. 8602-8612
Author(s):  
Vikash Singh ◽  
Chethana P. Gowda ◽  
Vishal Singh ◽  
Ashwinkumar S. Ganapathy ◽  
Dipti M. Karamchandani ◽  
...  

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) is an mRNA-binding protein that has an oncofetal pattern of expression. It is also expressed in intestinal tissue, suggesting that it has a possible role in intestinal homeostasis. To investigate this possibility, here we generated Villin CreERT2:Igf2bp1flox/flox mice, which enabled induction of an IGF2BP1 knockout specifically in intestinal epithelial cells (IECs) of adult mice. Using gut barrier and epithelial permeability assays and several biochemical approaches, we found that IGF2BP1 ablation in the adult intestinal epithelium causes mild active colitis and mild-to-moderate active enteritis. Moreover, the IGF2BP1 deletion aggravated dextran sodium sulfate–induced colitis. We also found that IGF2BP1 removal compromises barrier function of the intestinal epithelium, resulting from altered protein expression at tight junctions. Mechanistically, IGF2BP1 interacted with the mRNA of the tight-junction protein occludin (Ocln), stabilizing Ocln mRNA and inducing expression of occludin in IECs. Furthermore, ectopic occludin expression in IGF2BP1-knockdown cells restored barrier function. We conclude that IGF2BP1-dependent regulation of occludin expression is an important mechanism in intestinal barrier function maintenance and in the prevention of colitis.


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