scholarly journals Bacteriophage EK99P-1 Alleviates Enterotoxigenic Escherichia Coli K99-Induced Barrier Dysfunction and Inflammation

Author(s):  
Narae Kim ◽  
Min jeong Gu ◽  
Yoon-Chul Kye ◽  
Young-Jun Ju ◽  
Rira Hong ◽  
...  

Abstract Bacteriophages have long been used as a potential alternative to antibiotics for livestock due to their ability to specifically kill ETEC, which are a major cause of diarrhea in piglets. However, the control of ETEC infection by phages within intestinal epithelial cells, and their relationship with host immune responses, remain poorly understood. In this study, we evaluated the effect of phage EK99P-1 against ETEC K99-infected IPEC-J2. Phage EK99P-1 prevented ETEC K99-induced barrier disruption by attenuating the increased permeability mediated by the loss of tight junction proteins such as ZO-1, occludin, and claudin-3. ETEC K99-induced inflammatory responses, such as IL-8 secretion, were decreased by treatment with phage EK99P-1. We used a IPEC-J2/PBMC Transwell co-culture system to investigate whether the modulation of barrier disruption and chemokine secretion by phage EK99P-1 in ETEC K99-infected IPEC-J2 would influence basolateral immune cells. The results showed that phage EK99P-1 reduced the mRNA expression of ETEC K99-induced pro-inflammatory cytokines, IL-1β and IL-8, from PBMC collected on the basolateral side. Together, these results suggest that phage EK99P-1 prevented ETEC K99-induced barrier dysfunction in IPEC-J2 and alleviated inflammation caused by ETEC K99 infection. Reinforcement of the intestinal barrier by phage EK99P-1 also modulates the immune cell inflammatory response.

2021 ◽  
Author(s):  
Narae Kim ◽  
Min jeong Gu ◽  
Yoon-Chul Kye ◽  
Young-Jun Ju ◽  
Rira Hong ◽  
...  

Abstract Background Bacteriophages have long been used as a potential alternative to antibiotics for livestock due to their ability to specifically kill enterotoxigenic Escherichia coli (ETEC), which are a major cause of diarrhea in piglets. However, the control of ETEC infection by phages within intestinal epithelial cells, and their relationship with host immune responses, remain poorly understood. Results In this study, we evaluated the effect of phage EK99P-1 against ETEC K99-infected porcine intestinal epithelial cell line (IPEC-J2). Phage EK99P-1 prevented ETEC K99-induced barrier disruption by attenuating the increased permeability mediated by the loss of tight junction proteins such as zonula occludens-1 (ZO-1), occludin, and claudin-3. ETEC K99-induced inflammatory responses, such as IL-8 secretion, were decreased by treatment with phage EK99P-1. We used a IPEC-J2/peripheral blood mononuclear cell (PBMC) Transwell co-culture system to investigate whether the modulation of barrier disruption and chemokine secretion by phage EK99P-1 in ETEC K99-infected IPEC-J2 would influence basolateral immune cells. The results showed that phage EK99P-1 reduced the mRNA expression of ETEC K99-induced pro-inflammatory cytokines, interleukin (IL)-1β and IL-8, from pPBMC collected on the basolateral side. Conclusion Together, these results suggest that phage EK99P-1 prevented ETEC K99-induced barrier dysfunction in IPEC-J2 and alleviated inflammation caused by ETEC K99 infection. Reinforcement of the intestinal barrier by phage EK99P-1 also modulates the immune cell inflammatory response.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Shengbo Chen ◽  
Hongbin Liu ◽  
Zhijun Li ◽  
Jingyi Tang ◽  
Bing Huang ◽  
...  

AbstractIntestinal barrier function defects and dysregulation of intestinal immune responses are two key contributory factors in the pathogenesis of ulcerative colitis (UC). Phenazine biosynthesis-like domain-containing protein (PBLD) was recently identified as a tumor suppressor in gastric cancer, hepatocellular carcinoma, and breast cancer; however, its role in UC remains unclear. Therefore, we analyzed colonic tissue samples from patients with UC and constructed specific intestinal epithelial PBLD-deficient (PBLDIEC−/−) mice to investigate the role of this protein in UC pathogenesis. We found that epithelial PBLD was decreased in patients with UC and was correlated with levels of tight junction (TJ) and inflammatory proteins. PBLDIEC−/− mice were more susceptible to dextran sulfate sodium (DSS)- and 2,4,6-trinitrobenzene sulfonic acid-induced colitis compared with wild-type (WT) mice. In DSS-induced colitis, PBLDIEC−/− mice had impaired intestinal barrier function and greater immune cell infiltration in colonic tissue than WT mice. Furthermore, TJ proteins were markedly reduced in PBLDIEC−/− mice compared with WT mice with colitis. Nuclear factor (NF)-κB activation was markedly elevated and resulted in higher expression levels of downstream effectors (C–C motif chemokine ligand 20, interleukin [IL]-1β, IL-6, and tumor necrosis factor [TNF]-α) in colonic epithelial cells isolated from PBLDIEC−/− mice than WT mice with colitis. PBLD overexpression in intestinal epithelial cells (IECs) consistently inhibited TNF-α/interferon-γ-induced intestinal barrier disruption and TNF-α-induced inflammatory responses via the suppression of NF-κB. In addition, IKK inhibition (IKK-16) rescued excessive inflammatory responses induced by TNF-α in PBLD knockdown FHC cells. Co-immunoprecipitation assays showed that PBLD may interact with IKKα and IKKβ, thus inhibiting NF-κB signaling, decreasing inflammatory mediator production, attenuating colonic inflammation, and improving intestinal barrier function. Modulating PBLD expression may provide a novel approach for treatment in patients with UC.


2020 ◽  
Vol 11 ◽  
Author(s):  
Runze Quan ◽  
Chaoyue Chen ◽  
Wei Yan ◽  
Ying Zhang ◽  
Xi Zhao ◽  
...  

B cell-activating factor (BAFF) production is increased in septic patients. However, the specific role of BAFF in sepsis remains unknown. This study was designed to investigate the expression and function of BAFF in an experimental endotoxemia model and to identify the potential mechanisms. We established an endotoxemia mouse (6–8 weeks, 20–22 g) model by administering 30 mg/kg lipopolysaccharide (LPS). BAFF levels in the circulating system and organ tissues were measured 4 and 8 h after LPS injection. Survival rates in the endotoxemia mice were monitored for 72 h after BAFF blockade. The effects of BAFF blockade on systemic and local inflammation, organ injuries, and intestinal barrier function were also evaluated 4 h after LPS treatment. BAFF production was systemically and locally elevated after LPS challenge. BAFF blockade improved the survival rate, systemic inflammation, and multi-organ injuries. Moreover, BAFF blockade attenuated both intestinal inflammation and impaired intestinal permeability. BAFF blockade upregulated ZO-1 and occludin protein levels via the NF-κB/MLCK/MLC signaling pathway. These results suggested that BAFF blockade protects against lethal endotoxemia at least partially by alleviating inflammation, multi-organ injuries, and improving intestinal barrier function and provides a novel focus for further research on sepsis and experimental evidence for clinical therapy.


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.


Amino Acids ◽  
2021 ◽  
Author(s):  
Tatsuya Hasegawa ◽  
Ami Mizugaki ◽  
Yoshiko Inoue ◽  
Hiroyuki Kato ◽  
Hitoshi Murakami

AbstractIntestinal oxidative stress produces pro-inflammatory cytokines, which increase tight junction (TJ) permeability, leading to intestinal and systemic inflammation. Cystine (Cys2) is a substrate of glutathione (GSH) and inhibits inflammation, however, it is unclear whether Cys2 locally improves intestinal barrier dysfunction. Thus, we investigated the local effects of Cys2 on oxidative stress-induced TJ permeability and intestinal inflammatory responses. Caco-2 cells were cultured in a Cys2-supplemented medium for 24 h and then treated with H2O2 for 2 h. We assessed TJ permeability by measuring transepithelial electrical resistance and the paracellular flux of fluorescein isothiocyanate–dextran 4 kDa. We measured the concentration of Cys2 and GSH after Cys2 pretreatment. The mRNA expression of pro-inflammatory cytokines was assessed. In addition, the levels of TJ proteins were assessed by measuring the expression of TJ proteins in the whole cells and the ratio of TJ proteins in the detergent-insoluble fractions to soluble fractions (IS/S ratio). Cys2 treatment reduced H2O2-induced TJ permeability. Cys2 did not change the expression of TJ proteins in the whole cells, however, suppressed the IS/S ratio of claudin-4. Intercellular levels of Cys2 and GSH significantly increased in cells treated with Cys2. Cys2 treatment suppressed the mRNA expression of pro-inflammatory cytokines, and the mRNA levels were significantly correlated with TJ permeability. In conclusion, Cys2 treatment locally reduced oxidative stress-induced intestinal barrier dysfunction possively due to the mitigation of claudin-4 dislocalization. Furthermore, the effect of Cys2 on the improvement of intestinal barrier function is related to the local suppression of oxidative stress-induced pro-inflammatory responses.


Author(s):  
Athanasia Apostolou ◽  
Rohit A. Panchakshari ◽  
Antara Banerjee ◽  
Dimitris V. Manatakis ◽  
Maria D. Paraskevopoulou ◽  
...  

ABSTRACTThe intestinal epithelial barrier supports the symbiotic relationship between the microbiota colonizing the intestinal epithelium and the host immune system to maintain homeostasis. Leaky barrier is increasingly recognized as part of the pathogenesis of a number of chronic conditions in addition to inflammatory and infectious diseases. As our understanding on the regulation of the barrier remains limited, effective therapeutic targeting for the compromised barrier is still an unmet need. Here we combined advancements on the organoids and Organ-on-Chip technologies to establish a micro-engineered Colon Intestine-Chip for studying development and regulation of the human intestinal barrier. Our data demonstrate the significance of the endothelium in co-culture with the epithelial cells within a tissue-relevant microenvironment for the establishment of a tight epithelial barrier of polarized cells. Pathway analysis of the RNA sequencing (RNA-Seq), revealed significant upregulation of mechanisms relevant to the maturation of the intestinal epithelium in organoid-derived epithelial cells in co-culture with endothelium as compared to organoids maintained in suspension. We provide evidence that the Colon Intestine-Chip platform responds to interferon gamma (IFNγ), a prototype cytokine utilized to model inflammation-induced barrier disruption, by induction of apoptosis and reorganization of the apical junctional complexes as shown with other systems. We also describe the mechanism of action of interleukin 22 (IL-22) on mature, organoid-derived intestinal epithelial cells that is consistent with barrier disruption. Overall we propose the Colon Intestine-Chip as a promising human organoid-derived platform to decipher mechanisms driving the development of leaky gut in patients and enable their translation for this unmet medical need.


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