scholarly journals Bacteroides fragilis Strain ZY-312 Defense against Cronobacter sakazakii-Induced Necrotizing Enterocolitis In Vitro and in a Neonatal Rat Model

mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Hongying Fan ◽  
Zhenhui Chen ◽  
Ruqin Lin ◽  
Yangyang Liu ◽  
Xianbo Wu ◽  
...  
Keyword(s):  
Cell Death ◽  
Necrotizing Enterocolitis ◽  
Bacteroides Fragilis ◽  
Neonatal Rat ◽  
Cronobacter Sakazakii ◽  
Barrier Dysfunction ◽  
Content Type ◽  
Epithelial Barrier Dysfunction

ABSTRACT Cronobacter sakazakii is an important pathogen associated with the development of necrotizing enterocolitis (NEC), infant sepsis, and meningitis. Several randomized prospective clinical trials demonstrated that oral probiotics could decrease the incidence of NEC. Previously, we isolated and characterized a novel probiotic, Bacteroides fragilis strain ZY-312. However, it remains unclear how ZY-312 protects the host from the effects of C. sakazakii infection. To understand the underlying mechanisms triggering the probiotic effects, we tested the hypothesis that there was cross talk between probiotics/probiotics-modulated microbiota and the local immune system, governed by the permeability of the intestinal mucosa, using in vitro and in vivo models for the intestinal permeability. The probiotic effects of ZY-312 on intestinal epithelial cells were first examined, and the results revealed that ZY-312 inhibited C. sakazakii invasion, C. sakazakii-induced dual cell death (pyroptosis and apoptosis), and epithelial barrier dysfunction in vitro and in vivo. The presence of ZY-312 also resulted in decreased expression of an inflammasome (NOD-like receptor family member pyrin domain-containing protein 3 [NLRP3]), caspase-3, and serine protease caspase-1 in a neonatal rat model. Furthermore, ZY-312 significantly modulated the compositions of the intestinal bacterial communities and decreased the relative abundances of Proteobacteria and Gammaproteobacteria but increased the relative abundances of Bacteroides and Bacillus in neonatal rats. In conclusion, our findings have shown for the first time that the probiotic B. fragilis ZY-312 suppresses C. sakazakii-induced NEC by modulating the proinflammatory response and dual cell death (apoptosis and pyroptosis). IMPORTANCE Cronobacter sakazakii is an opportunistic pathogenic bacterium that can cause necrotizing enterocolitis (NEC). However, the mechanism of pathogenicity of C. sakazakii is largely unknown. Here we have now demonstrated that apoptotic and pyroptotic stimuli are effectors of C. sakazakii-induced NEC. Previously, we isolated a novel probiotic strain candidate from fecal samples from healthy infants and characterized it as Bacteroides fragilis strain ZY-312. Functional characterization reveals that ZY-312 inhibited C. sakazakii invasion, restoring epithelial barrier dysfunction, decreasing the expression of inflammatory cytokines, and reducing dual cell death (pyroptosis and apoptosis). Furthermore, the presence of ZY-132 was sufficient to hinder the adverse reaction seen with C. sakazakii in a C. sakazakii-induced NEC model. Taking the results together, our study demonstrated the utility of ZY-312 as a promising probiotic agent for the prevention of NEC.

scholarly journals Bacteroides fragilis defense against Cronobacter sakazakii-induced pathogenicity by regulating the intestinal epithelial barrier function and attenuating both apoptotic and pyroptotic cell death

2018 ◽  
Author(s):  
Hongying Fan ◽  
Ruqin Lin ◽  
Zhenhui Chen ◽  
Xingyu Leng ◽  
Xianbo Wu ◽  
...  
Keyword(s):  
Cell Death ◽  
Necrotizing Enterocolitis ◽  
Neonatal Rat ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Cronobacter Sakazakii ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Dysfunction

AbstractCronobacter sakazakii (CS), an important pathogen, is associated with the development of necrotizing enterocolitis (NEC), infant sepsis, and meningitis. Several randomized prospective clinical trials demonstrated that oral probiotics could decrease the incidence of NEC. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. However, it remains unclear how ZY-312 protects the host from the effects of CS infection. To understand the underlying mechanisms triggering the probiotic effects, we tested the hypothesis that there was a cross-talk between probiotics/probiotics-modulated microbiota and the local immune system, governed by the permeability of the intestinal mucosa using in vitro and in vivo models for the intestinal permeability. The probiotic effects of ZY-312 on intestinal epithelial cells were first examined, which revealed that ZY-312 inhibited CS invasion, CS-induced dual cell death (pyroptosis and apoptosis), and epithelial barrier dysfunction in vitro and in vivo. ZY-312 also decreased the expression of an inflammasome (NOD-like receptor family member pyrin domain-containing protein 3 (NLRP3), caspase-3, and serine protease caspase-1 in a neonatal rat model. Furthermore, ZY-312 significantly modulated the compositions of the intestinal bacterial communities, and decreased the relative abundances of Proteobacteria, Gamma proteobacteria, but increased the relative abundance of Bacteroides and Bacillus in neonatal rats. In conclusion, our findings have shown for the first time that the probiotic, B. fragilis ZY-312, suppresses CS-induced NEC by modulating the pro-inflammatory response and dual cell death (apoptosis and pyroptosis).Author summaryCronobacter sakazakii, a major necrotizing enterocolitis pathogen, is used as a model microorganism for the study of opportunistic bacteria in the pathogenesis of necrotizing enterocolitis. Here, we have now unequivocally demonstrated that both apoptotic and pyroptotic stimuli contribute to the pathogenesis of Cronobacter sakazakii -induced necrotizing enterocolitis. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. We found that the ZY-312 defense against Cronobacter sakazakii-induced necrotizing enterocolitis by inhibiting Cronobacter sakazakii invasion, epithelial barrier dysfunction, the expression of inflammatory cytokines and dual cell death (pyroptosis and apoptosis). This study demonstrates the utility of ZY-312 as a promising probiotic agent for the prevention and treatment of various intestinal diseases, including NEC.

scholarly journals Advanced Organ-on-a-Chip Devices to Investigate Liver Multi-Organ Communication: Focus on Gut, Microbiota and Brain

2019 ◽  
Vol 6 (4) ◽  
pp. 91 ◽  
Author(s):  
Lucia Boeri ◽  
Luca Izzo ◽  
Lorenzo Sardelli ◽  
Marta Tunesi ◽  
Diego Albani ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
In Vitro Modeling ◽  
Reciprocal Influence ◽  
Organ On A Chip ◽  
Epithelial Barrier Dysfunction

The liver is a key organ that can communicate with many other districts of the human body. In the last few decades, much interest has focused on the interaction between the liver and the gut microbiota, with their reciprocal influence on biosynthesis pathways and the integrity the intestinal epithelial barrier. Dysbiosis or liver disorders lead to0 epithelial barrier dysfunction, altering membrane permeability to toxins. Clinical and experimental evidence shows that the permeability hence the delivery of neurotoxins such as LPS, ammonia and salsolinol contribute to neurological disorders. These findings suggested multi-organ communication between the gut microbiota, the liver and the brain. With a view to in vitro modeling this liver-based multi-organ communication, we describe the latest advanced liver-on-a-chip devices and discuss the need for new organ-on-a-chip platforms for in vitro modeling the in vivo multi-organ connection pathways in physiological and pathological situations.

scholarly journals The role of secreted Hsp90α in HDM-induced asthmatic airway epithelial barrier dysfunction

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Cuiping Ye ◽  
Chaowen Huang ◽  
Mengchen Zou ◽  
Yahui Hu ◽  
Lishan Luo ◽  
...  
Keyword(s):  
Barrier Function ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Asthmatic Airway ◽  
Epithelial Barrier Dysfunction

Abstract Background The dysfunction of airway epithelial barrier is closely related to the pathogenesis of asthma. Secreted Hsp90α participates in inflammation and Hsp90 inhibitor protects endothelial dysfunction. In the current study, we aimed to explore the role of secreted Hsp90α in asthmatic airway epithelial barrier function. Methods Male BALB/c mice were sensitized and challenged with HDM to generate asthma model. The 16HBE and Hsp90α-knockdown cells were cultured and treated according to the experiment requirements. Transepithelial Electric Resistance (TEER) and permeability of epithelial layer in vitro, distribution and expression of junction proteins both in vivo and in vitro were used to evaluate the epithelial barrier function. Western Blot was used to evaluate the expression of junction proteins and phosphorylated AKT in cells and lung tissues while ELISA were used to evaluate the Hsp90α expression and cytokines release in the lung homogenate. Results HDM resulted in a dysfunction of airway epithelial barrier both in vivo and in vitro, paralleled with the increased expression and release of Hsp90α. All of which were rescued in Hsp90α-knockdown cells or co-administration of 1G6-D7. Furthermore, either 1G6-D7 or PI3K inhibitor LY294002 suppressed the significant phosphorylation of AKT, which caused by secreted and recombinant Hsp90α, resulting in the restoration of epithelial barrier function. Conclusions Secreted Hsp90α medicates HDM-induced asthmatic airway epithelial barrier dysfunction via PI3K/AKT pathway, indicating that anti-secreted Hsp90α therapy might be a potential treatment to asthma in future.

scholarly journals Putative Inv Is Essential for Basolateral Invasion of Caco-2 Cells and Acts Synergistically with OmpA To AffectIn VitroandIn VivoVirulence of Cronobacter sakazakii ATCC 29544

2014 ◽  
Vol 82 (5) ◽  
pp. 1755-1765 ◽  
Author(s):  
Dilini Chandrapala ◽  
Kyumson Kim ◽  
Younho Choi ◽  
Amal Senevirathne ◽  
Dong-Hyun Kang ◽  
...  
Keyword(s):  
Outer Membrane Proteins ◽  
Opportunistic Pathogen ◽  
Additive Effect ◽  
Neonatal Meningitis ◽  
Cronobacter Sakazakii ◽  
Content Type ◽  
Enteric Infections ◽  
Culture Models

ABSTRACTCronobacter sakazakiiis an opportunistic pathogen that causes neonatal meningitis and necrotizing enterocolitis. Its interaction with intestinal epithelium is important in the pathogenesis of enteric infections. In this study, we investigated the involvement of theinvgene in the virulence ofC. sakazakiiATCC 29544in vitroandin vivo. Sequence analysis ofC. sakazakiiATCC 29544invrevealed that it is different from otherC. sakazakiiisolates. In various cell culture models, an Δinvdeletion mutant showed significantly lowered invasion efficiency, which was restored upon genetic complementation. Studying invasion potentials using tight-junction-disrupted Caco-2 cells suggested that theinvgene product mediates basolateral invasion ofC. sakazakiiATCC 29544. In addition, comparison of invasion potentials of double mutant (ΔompA Δinv) and single mutants (ΔompAand Δinv) provided evidence for an additive effect of the two putative outer membrane proteins. Finally, the importance ofinvand the additive effect of putative Inv and OmpA were also proven in anin vivorat pup model. This report is the first to demonstrate two proteins working synergisticallyin vitro, as well asin vivoinC. sakazakiipathogenesis.

scholarly journals Ma Xing Shi Gan Decoction Protects against PM2.5-Induced Lung Injury through Suppression of Epithelial-to-Mesenchymal Transition (EMT) and Epithelial Barrier Disruption

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Ye-fang Wang ◽  
Yu-xiang Fei ◽  
Bo Zhao ◽  
Qi-yang Yin ◽  
Jian-ping Zhu ◽  
...  
Keyword(s):  
Lung Injury ◽  
Epithelial To Mesenchymal Transition ◽  
Cell Model ◽  
Alveolar Epithelial Cell ◽  
Epithelial Barrier ◽  
Barrier Dysfunction ◽  
Mesenchymal Transition ◽  
Epithelial Barrier Dysfunction

This research was designed to explore the effect of Ma Xing Shi Gan decoction (MXD) in alleviating particulate matter less than 2.5 μm in diameter (PM2.5) induced lung injury from the perspective of epithelial barrier protection and inhibition of epithelial-to-mesenchymal transition (EMT). Rats were exposed to PM2.5 to establish a lung injury model in vivo, and a PM2.5-stimulated primary cultured type II alveolar epithelial cell model was introduced in vitro. Our results indicated that MXD alleviated the weight loss and pathologic changes and improved the epithelial barrier dysfunction. MXD also significantly inhibited the TGF-β/Smad3 pathway, increased the level of ZO-1 and claudin-5, and reversed the EMT process. Notably, the protection of MXD was abolished by TGF-β in vitro. Our results indicated that MXD has a protection against PM2.5-induced lung injury. The proposed mechanism is reversing PM2.5-induced EMT through inhibiting TGF-β/Smad3 pathway and then upregulating the expression of tight-junction proteins.

scholarly journals Dps and DpsL Mediate SurvivalIn VitroandIn Vivoduring the Prolonged Oxidative Stress Response in Bacteroides fragilis

2015 ◽  
Vol 197 (20) ◽  
pp. 3329-3338 ◽  
Author(s):  
Michael I. Betteken ◽  
Edson R. Rocha ◽  
C. Jeffrey Smith
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Peritoneal Cavity ◽  
Bacteroides Fragilis ◽  
Oxidative Stress Response ◽  
Iron Storage ◽  
Content Type ◽  
Iron Storage Proteins

ABSTRACTBacteroides fragilisis a Gram-negative anaerobe and member of the human intestinal tract microbiome, where it plays many beneficial roles. However, translocation of the organism to the peritoneal cavity can lead to peritonitis, intra-abdominal abscess formation, bacteremia, and sepsis. During translocation,B. fragilisis exposed to increased oxidative stress from the oxygenated tissues of the peritoneal cavity and the immune response. In order to survive,B. fragilismounts a robust oxidative stress response consisting of an acute and a prolonged oxidative stress (POST) response. This report demonstrates that the ability to induce high levels of resistance totert-butyl hydroperoxide (tBOOH) after extended exposure to air can be linked to the POST response. Disk diffusion assays comparing the wild type to a Δdpsmutant and a ΔdpsΔbfrmutant showed greater sensitivity of the mutants to tBOOH after exposure to air, suggesting that Dps and DpsL play a role in the resistance phenotype. Complementation studies withdpsorbfr(encoding DpsL) restored tBOOH resistance, suggesting a role for both of these ferritin-family proteins in the response. Additionally, cultures treated with the iron chelator dipyridyl were not killed by tBOOH, indicating Dps and DpsL function by sequestering iron to prevent cellular damage. Anin vivoanimal model showed that the ΔdpsΔbfrmutant was attenuated, indicating that management of iron is important for survival within the abscess. Together, these data demonstrate a role for Dps and DpsL in the POST response which mediates survivalin vitroandin vivo.IMPORTANCEB. fragilisis the anaerobe most frequently isolated from extraintestinal opportunistic infections, but there is a paucity of information about the factors that allow this organism to survive outside its normal intestinal environment. This report demonstrates that the iron storage proteins Dps and DpsL protect against oxidative stress and that they contribute to survival bothin vitroandin vivo. Additionally, this work demonstrates an important role for the POST response inB. fragilissurvival and provides insight into the complex regulation of this response.

P3116New role of EPAC1 in Anthracycline-induced cardiotoxicity and anticancer therapy

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Belhadef ◽  
M Ribeiro ◽  
M Mazevet ◽  
M Laudette ◽  
B Crozatier ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Membrane ◽  
Reactive Oxygen Species Generation ◽  
Neonatal Rat ◽  
Dna Intercalation ◽  
Mice Model ◽  
Rat Cardiomyocytes ◽  
Knock Out

Abstract Introduction Doxorubicin (Dox) is an anthracycline commonly used to treat many types of cancer; unfortunately this chemotherapeutic agent induces many side effects such as cardiotoxicity leading to dilated cardiomyopathy (DCM). The cardiotoxicity of Dox has been related to reactive oxygen species generation, DNA intercalation, topoisomerase II inhibition and bioenergetics alterations leading to cardiomyocyte death. Objective Nowadays the challenge is to find new treatment options aiming at reducing Dox cardiotoxicity. Epac (exchange protein directly activated by cAMP) signaling could be worth investigating as Epac activates small G proteins which are known to be involved in Dox-induced cardiotoxicity. Methods We investigated the time/dose-dependent Dox effect on Epac signaling in both in vivo mice model (C57Bl63/ Knock-out Epac1 mice, iv injections, 12mg/kg cumulative dose) and in vitro (primary culture of neonatal rat cardiomyocytes (NRVM, 24h, Dox 1μM). Results In vivo, Dox-treated mice developed a DCM associated with Ca2+ homeostasis dysfunction (increase of Ca2+ waves and Ca2+ leaks). In vitro, as measured by flow cytometry and western blot, Dox (1μM) induced DNA damages and cell death in NRVM. This cell death is associated with apoptotic features including mitochondrial membrane permeabilization, caspase activation and cell size reduction. The inhibition of Epac1 (ESI09, CE3F4) decreased Dox-induced DNA damage, loss of mitochondrial membrane potential, apoptosis and finally cardiomyocyte death. Moreover, in vivo, Epac1 KO mice were protected against Dox-induced cardiotoxicity by unaltered cardiac function (no DCM) and calcium homeostasis at 15 weeks post-treatment. Conclusion Inhibition of Epac1 could be a valuable therapeutic strategy to limit Dox-induced cardiomyopathy during cancer chemotherapy. Indeed, preliminary data show also that preventing Dox-induced cardiotoxicity, the inhibition of Epac1 can also potentiate cancerous cells death. Acknowledgement/Funding Labex Lermit (ANR 0033), Torino and Inserm

O-027 PTPN2 Deficiency Exacerbates Epithelial Barrier Dysfunction in vivo and in vitro via Redistribution of Occludin and ZO-1

2013 ◽  
Vol 19 ◽  
pp. S16
Author(s):  
Ronald Marchelletta ◽  
Stephan Myers ◽  
Lucas Bernts ◽  
Taylaur Smith ◽  
Young Park ◽  
...  
Keyword(s):  
Epithelial Barrier ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Dysfunction

scholarly journals Secreted Cyclic Di-GMP Induces Stalk Cell Differentiation in the Eukaryote Dictyostelium discoideum

2015 ◽  
Vol 198 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Zhi-hui Chen ◽  
Pauline Schaap
Keyword(s):  
Cell Death ◽  
Cell Differentiation ◽  
Dictyostelium Discoideum ◽  
Autophagic Cell Death ◽  
Stalk Cell ◽  
Signal Molecule ◽  
Major Life ◽  
Content Type

Cyclic di-GMP (c-di-GMP) is currently recognized as the most widely used intracellular signal molecule in prokaryotes, but roles in eukaryotes were only recently discovered. In the social amoebaDictyostelium discoideum, c-di-GMP, produced by a prokaryote-type diguanylate cyclase, induces the differentiation of stalk cells, thereby enabling the formation of spore-bearing fruiting bodies. In this review, we summarize the currently known mechanisms that control the major life cycle transitions ofDictyosteliumand focus particularly on the role of c-di-GMP in stalk formation. Stalk cell differentiation has characteristics of autophagic cell death, a process that also occurs in higher eukaryotes. We discuss the respective roles of c-di-GMP and of another signal molecule, differentiation-inducing factor 1, in autophagic cell deathin vitroand in stalk formationin vivo.

scholarly journals CD4+T Cell Hyporesponsiveness after Repeated Exposure to Schistosoma mansoni Larvae Is Dependent upon Interleukin-10

2015 ◽  
Vol 83 (4) ◽  
pp. 1418-1430 ◽  
Author(s):  
Catriona T. Prendergast ◽  
David E. Sanin ◽  
Peter C. Cook ◽  
Adrian P. Mountford
Keyword(s):  
Cell Death ◽  
T Cell ◽  
Schistosoma Mansoni ◽  
Interleukin 2 ◽  
Interleukin 10 ◽  
Multiple Infections ◽  
Content Type ◽  
Key Factor

The effect that multiple percutaneous exposures toSchistosomalarvae has on the development of early CD4+lymphocyte reactivity is unclear, yet it is important in the context of humans living in areas where schistosomiasis is endemic. In a murine model of multiple infections, we show that exposure of mice to repeated doses (4×) ofSchistosoma mansonicercariae, compared to a single dose (1×), results in CD4+T cell hyporesponsiveness within the skin-draining lymph nodes (sdLN), manifested as reduced CD4+cell proliferation and cytokine production. FoxP3+CD4+regulatory T cells were present in similar numbers in the sdLN of 4× and 1× mice and thus are unlikely to have a role in effecting hyporesponsiveness. Moreover, anergy of the CD4+cell population from 4× mice was slight, as proliferation was only partly circumvented through thein vitroaddition of exogenous interleukin-2 (IL-2), and thein vivoblockade of the regulatory molecule PD1 had a minimal effect on restoring responsiveness. In contrast, IL-10 was observed to be critical in mediating hyporesponsiveness, as CD4+cells from the sdLN of 4× mice deficient for IL-10 were readily able to proliferate, unlike those from 4× wild-type cohorts. CD4+cells from the sdLN of 4× mice exhibited higher levels of apoptosis and cell death, but in the absence of IL-10, there was significantly less cell death. Combined, our data show that IL-10 is a key factor in the development of CD4+T cell hyporesponsiveness after repeated parasite exposure involving CD4+cell apoptosis.

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