Seaweed polysaccharide mitigates intestinal barrier dysfunction induced by enterotoxigenic Escherichia coli through NF‐κB pathway suppression in porcine intestinal epithelial cells

2021 ◽  
Author(s):  
Xiaobo Guo ◽  
Jun Chen ◽  
Jin Yang ◽  
Qin He ◽  
Bowen Luo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Intestinal Barrier ◽  
Enterotoxigenic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Intestinal Barrier Dysfunction

scholarly journals Mesenchymal stem cell-derived microvesicles improve intestinal barrier function by restoring mitochondrial dynamic balance in sepsis rats

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Danyang Zheng ◽  
Henan Zhou ◽  
Hongchen Wang ◽  
Yu Zhu ◽  
Yue Wu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Barrier Function ◽  
Intestinal Epithelial Cells ◽  
Dynamic Balance ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Mitochondrial Dynamic ◽  
Intestinal Barrier Dysfunction

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.

scholarly journals Binding of CFA/I Pili of Enterotoxigenic Escherichia coli to Asialo-GM1 Is Mediated by the Minor Pilin CfaE

2016 ◽  
Vol 84 (5) ◽  
pp. 1642-1649 ◽  
Author(s):  
T. P. Vipin Madhavan ◽  
James D. Riches ◽  
Martin J. Scanlon ◽  
Glen C. Ulett ◽  
Harry Sakellaris
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Current Model ◽  
Large Family ◽  
Binding Activity ◽  
Enterotoxigenic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Content Type ◽  
Asialo Gm1

CFA/I pili are representatives of a large family of related pili that mediate the adherence of enterotoxigenicEscherichia colito intestinal epithelial cells. They are assembled via the alternate chaperone-usher pathway and consist of two subunits, CfaB, which makes up the pilus shaft and a single pilus tip-associated subunit, CfaE. The current model of pilus-mediated adherence proposes that CFA/I has two distinct binding activities; the CfaE subunit is responsible for binding to receptors of unknown structure on erythrocyte and intestinal epithelial cell surfaces, while CfaB binds to various glycosphingolipids, including asialo-GM1. In this report, we present two independent lines of evidence that, contrary to the existing model, CfaB does not bind to asialo-GM1 independently of CfaE. Neither purified CfaB subunits nor CfaB assembled into pili bind to asialo-GM1. Instead, we demonstrate that binding activity toward asialo-GM1 resides in CfaE and this is essential for pilus binding to Caco-2 intestinal epithelial cells. We conclude that the binding activities of CFA/I pili for asialo-GM1, erythrocytes, and intestinal cells are inseparable, require the same amino acid residues in CfaE, and therefore depend on the same or very similar binding mechanisms.

scholarly journals Adherent-Invasive and Non-Invasive Escherichia coli Isolates Differ in Their Effects on Caenorhabditis elegans’ Lifespan

2021 ◽  
Vol 9 (9) ◽  
pp. 1823
Author(s):  
Maria Beatriz de Sousa de Sousa Figueiredo ◽  
Elizabeth Pradel ◽  
Fanny George ◽  
Séverine Mahieux ◽  
Isabelle Houcke ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Caenorhabditis Elegans ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Host Bacterium ◽  
Soil Nematode ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
E Coli ◽  
C Elegans

The adherent-invasive Escherichia coli (AIEC) pathotype has been implicated in the pathogenesis of inflammatory bowel diseases in general and in Crohn’s disease (CD) in particular. AIEC strains are primarily characterized by their ability to adhere to and invade intestinal epithelial cells. However, the genetic and phenotypic features of AIEC isolates vary greatly as a function of the strain’s clonality, host factors, and the gut microenvironment. It is thus essential to identify the determinants of AIEC pathogenicity and understand their role in intestinal epithelial barrier dysfunction and inflammation. We reasoned that soil nematode Caenorhabditis elegans (a simple but powerful model of host-bacterium interactions) could be used to study the virulence of AIEC vs. non- AIEC E. coli strains. Indeed, we found that the colonization of C. elegans (strain N2) by E. coli impacted survival in a strain-specific manner. Moreover, the AIEC strains’ ability to invade cells in vitro was linked to the median lifespan in C. elegans (strain PX627). However, neither the E. coli intrinsic invasiveness (i.e., the fact for an individual strain to be characterized as invasive or not) nor AIEC’s virulence levels (i.e., the intensity of invasion, established in % from the infectious inoculum) in intestinal epithelial cells was correlated with C. elegans’ lifespan in the killing assay. Nevertheless, AIEC longevity of C. elegans might be a relevant model for screening anti-adhesion drugs and anti-invasive probiotics.

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