scholarly journals 3343 Identification of host-microbial interaction networks that mediate intestinal epithelial barrier function in necrotizing enterocolitis

2019 ◽  
Vol 3 (s1) ◽  
pp. 13-13
Author(s):  
David R Hill ◽  
Roberto Cieza ◽  
Veda K. Yadagiri ◽  
Phillip Tarr ◽  
Jason R. Spence ◽  
...  

OBJECTIVES/SPECIFIC AIMS: The central goal of this proposal is to characterize the mechanisms that mediate success or failure of immature intestinal barrier in necrotizing enterocilitis. METHODS/STUDY POPULATION: To do this, I will utilize stem cell derived human intestinal organoids (HIOs), an innovative model of the immature intestine, and a cohort of bacterial isolates collected from premature infants who developed NEC to interrogate the cause-effect relationship of these strains on maintenance of the intestinal barrier. I hypothesize that the epithelial response to bacterial colonization is strain-dependent and results in differences in inflammatory signaling that shape epithelial barrier function in the immature intestine. RESULTS/ANTICIPATED RESULTS: Preliminary data shows that colonization of HIOs with different bacteria leads to species-specific changes in barrier function, and some species selectively damage the epithelial barrier while others enhance epithelial barrier function. I have identified key inflammatory signals that serve as central drivers of intestinal barrier function. DISCUSSION/SIGNIFICANCE OF IMPACT: Characterization of this process is expected to substantially advance scientific understanding of early events in NEC pathogenesis and lead to new opportunities for targeted therapeutic intervention to accelerate barrier maturation or prevent hyperinflammatory reactivity in the neonatal intestine. The research proposed in this application represents an entirely novel approach to studying host-microbial interactions in the immature. Conceptually, this novel translational approach will help to define the pivotal role of colonizing bacteria in initiating epithelial inflammation in NEC patients.

2015 ◽  
Vol 308 (12) ◽  
pp. G981-G993 ◽  
Author(s):  
Juan Antonio Rodríguez-Feo ◽  
Marta Puerto ◽  
Carolina Fernández-Mena ◽  
Cristina Verdejo ◽  
José Manuel Lara ◽  
...  

Inflammatory bowel disease (IBD) is characterized by an impaired intestinal barrier function. We aimed to investigate the role of reticulon-4B (RTN-4B/NOGO-B), a structural protein of the endoplasmic reticulum, in intestinal barrier function and IBD. We used immunohistochemistry, confocal microscopy, real-time PCR, and Western blotting to study tissue distribution and expression levels of RTN-4B/NOGO-B in control and IBD samples from mouse and humans. We also targeted RTN-4B/NOGO-B using siRNAs in cultured human intestinal epithelial cell (IECs). Epithelial barrier permeability was assessed by transepithelial electrical resistance (TEER) measurement. RTN-4B/NOGO-B is expressed in the intestine mainly by IECs. Confocal microscopy revealed a colocalization of RTN-4B, E-cadherin, and polymerized actin fibers in tissue and cultured IECs. RTN-4B mRNA and protein expression were lower in the colon of IL-10−/− compared with wild-type mice. Colocalization of RTN-4B/E-cadherin/actin was reduced in the colon of IL-10−/− mice. Analysis of endoscopic biopsies from IBD patients showed a significant reduction of RTN-4B/NOGO-B expression in inflamed mucosa compared with control. Treatment of IECs with H2O2 reduced TEER values and triggered phosphorylation of RTN-4B in serine 107 residues as well as downregulation of RTN-4B expression. Acute RTN-4B/NOGO-B knockdown by siRNAs resulted in a decreased TEER values and reduction of E-cadherin and α-catenin expression and in the amount of F-actin-rich filaments in IECs. Epithelial RTN-4B/NOGO-B was downregulated in human and experimental IBD. RTN-4B participates in the intestinal epithelial barrier function, most likely via its involvement in E-cadherin, α-catenin expression, and actin cytoskeleton organization at sites of cell-to-cell contacts.


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.


Pharmacology ◽  
2019 ◽  
Vol 105 (1-2) ◽  
pp. 102-108 ◽  
Author(s):  
Norio Nishii ◽  
Tadayuki Oshima ◽  
Min Li ◽  
Hirotsugu Eda ◽  
Kumiko Nakamura ◽  
...  

Introduction: Lubiprostone, a chloride channel activator, is said to reduce epithelial permeability. However, whether lubiprostone has a direct effect on the epithelial barrier function and how it modulates the intestinal barrier function remain unknown. Therefore, the effects of lubiprostone on intestinal barrier function were evaluated in vitro. Methods: Caco-2 cells were used to assess the intestinal barrier function. To examine the expression of claudins, immunoblotting was performed with specific antibodies. The effects of lubiprostone on cytokines (IFNγ, IL-6, and IL-1β) and aspirin-induced epithelial barrier disruption were assessed by transepithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC) labeled-dextran permeability. Results: IFNγ, IL-6, IL-1β, and aspirin significantly decreased TEER and increased epithelial permeability. Lubiprostone significantly improved the IFNγ-induced decrease in TEER in a dose-dependent manner. Lubiprostone significantly reduced the IFNγ-induced increase in FITC labeled-dextran permeability. The changes induced by IL-6, IL-1β, and aspirin were not affected by lubiprostone. The expression of claudin-1, but not claudin-3, claudin-4, occludin, and ZO-1 was significantly increased by lubiprostone. Conclusion: Lubiprostone significantly improved the IFNγ-induced decrease in TEER and increase in FITC labeled-dextran permeability. Lubiprostone increased the expression of claudin-1, and this increase may be related to the effect of lubiprostone on the epithelial barrier function.


2017 ◽  
Vol 8 (3) ◽  
pp. 1144-1151 ◽  
Author(s):  
Qianru Chen ◽  
Oliver Chen ◽  
Isabela M. Martins ◽  
Hu Hou ◽  
Xue Zhao ◽  
...  

Alaska pollock skin derived collagen peptides could be considered as dietary supplements for intestinal barrier function promotion and associated diseases.


Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 486 ◽  
Author(s):  
Li ◽  
Mao ◽  
Zhang ◽  
Yu ◽  
Zhu

Succinate is a metabolic intermediate of the tricarboxylic acid (TCA) cycle in all aerobic organisms, and is also a vital microbial metabolite in the gut. Although succinate is known to regulate intestinal metabolism and immune function, its role in the protection of the intestinal epithelial barrier function and inflammation is poorly characterized. In this study, we evaluated the effects of succinate on intestinal epithelial barrier function and inflammation in pigs. Twenty-four growing pigs were distributed into three groups (n = 8) and received either a basal diet (control group) or the same diet supplemented with 0.1% succinate or 1% succinate. The diet supplemented with 1% succinate led to alterations in the intestinal morphology. We confirmed in vitro that 5 mM succinate treatment modulated intestinal epithelial permeability by increased transepithelial electrical resistance (TEER) in intestinal porcine epithelial cell (IPEC)-J2 cells. Furthermore, succinate treatment increased the abundance of tight junction proteins claudin-1, zona occluden (ZO)-1, and ZO-2 in the jejunum in vivo and in vitro. In addition, dietary succinate supplementation promoted the expression of inflammatory cytokines interleukin (IL)-25, IL-10, IL-8, and IL-18 in the jejunum. Taken together, these data identify a novel role of succinate in the modulation of intestinal epithelial barrier function, which may be a nutritional target to improve gut health in animals.


2021 ◽  
Author(s):  
Hassan M. Heshmati

Nonalcoholic fatty liver disease (NAFLD) is a leading liver disease worldwide with a prevalence of approximately 25% among adult population. The highest prevalence is observed in Middle East and the lowest prevalence in Africa. NAFLD is a spectrum of liver disorders ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). Pro-inflammatory diet, overweight/obesity, inflammation, insulin resistance, prediabetes, type 2 diabetes, dyslipidemia, disrupted gut microbiome, and impaired intestinal barrier function are important risk factors associated with and/or contributing to NAFLD. Gut microbiome is a complex and diverse microbial ecosystem essential for the maintenance of human health. It is influenced by several factors including diet and medications. Gut microbiome can be disrupted in NAFLD. Intestinal epithelial barrier is the largest and most important barrier against the external environment and plays an important role in health and disease. Several factors including diet and gut microbiome impact intestinal barrier function. NAFLD can be associated with impaired intestinal barrier function (increased intestinal permeability). There are no specific drugs that directly treat NAFLD. The first-line therapy of NAFLD is currently lifestyle intervention. Weight loss is an important component in the treatment of NAFLD subjects who have excess body weight. Gut microbiome and intestinal epithelial barrier are becoming promising targets for the treatment of several diseases including NAFLD. In the absence of approved pharmacotherapy for the treatment of NAFLD/NASH, in addition to lifestyle intervention and weight loss (in case of excess body weight), focus should also be on correcting gut microbiome and intestinal permeability (directly and/or through gut microbiome modulation) using diet (e.g., low-fat diet, high-fiber diet, and Mediterranean diet), prebiotics (nondigestible food ingredients), probiotics (nonpathogenic living microorganisms), synbiotics (combination of prebiotics and probiotics), and fecal microbiota transplantation (transfer of healthy stool).


2015 ◽  
Vol 114 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Jie Zhao ◽  
Peiliang Shi ◽  
Ye Sun ◽  
Jing Sun ◽  
Jian-Ning Dong ◽  
...  

A defect in the intestinal barrier is one of the characteristics of Crohn's disease (CD). The tight junction (TJ) changes and death of epithelial cells caused by intestinal inflammation play an important role in the development of CD. DHA, a long-chain PUFA, has been shown to be helpful in treating inflammatory bowel disease in experimental models by inhibiting the NF-κB pathway. The present study aimed at investigating the specific effect of DHA on the intestinal barrier function in IL-10-deficient mice. IL-10-deficient mice (IL-10− / −) at 16 weeks of age with established colitis were treated with DHA (i.g. 35·5 mg/kg per d) for 2 weeks. The severity of their colitis, levels of pro-inflammatory cytokines, epithelial gene expression, the distributions of TJ proteins (occludin and zona occludens (ZO)-1), and epithelial apoptosis in the proximal colon were measured at the end of the experiment. DHA treatment attenuated the established colitis and was associated with reduced infiltration of inflammatory cells in the colonic mucosa, lower mean histological scores and decreased levels of pro-inflammatory cytokines (IL-17, TNF-α and interferon-γ). Moreover, enhanced barrier function was observed in the DHA-treated mice that resulted from attenuated colonic permeability, rescued expression and corrected distributions of occludin and ZO-1. The results of the present study indicate that DHA therapy may ameliorate experimental colitis in IL-10− / − mice by improving the intestinal epithelial barrier function.


2010 ◽  
Vol 298 (6) ◽  
pp. G807-G819 ◽  
Author(s):  
Christina L. Ohland ◽  
Wallace K. MacNaughton

The intestinal tract is a diverse microenvironment where more than 500 species of bacteria thrive. A single layer of epithelium is all that separates these commensal microorganisms and pathogens from the underlying immune cells, and thus epithelial barrier function is a key component in the arsenal of defense mechanisms required to prevent infection and inflammation. The epithelial barrier consists of a dense mucous layer containing secretory IgA and antimicrobial peptides as well as dynamic junctional complexes that regulate permeability between cells. Probiotics are live microorganisms that confer benefit to the host and that have been suggested to ameliorate or prevent diseases including antibiotic-associated diarrhea, irritable bowel syndrome, and inflammatory bowel disease. Probiotics likely function through enhancement of barrier function, immunomodulation, and competitive adherence to the mucus and epithelium. This review summarizes the evidence about effects of the many available probiotics with an emphasis on intestinal barrier function and the mechanisms affected by probiotics.


2008 ◽  
Vol 294 (1) ◽  
pp. G139-G147 ◽  
Author(s):  
Xiaoyi Sun ◽  
Hua Yang ◽  
Keisuke Nose ◽  
Satoko Nose ◽  
Emir Q. Haxhija ◽  
...  

Loss of intestinal epithelial barrier function (EBF) is a major problem associated with total parenteral nutrition (TPN) administration. We have previously identified intestinal intraepithelial lymphocyte (IEL)-derived interferon-γ (IFN-γ) as a contributing factor to this barrier loss. The objective was to determine whether other IEL-derived cytokines may also contribute to intestinal epithelial barrier breakdown. C57BL6J male mice received TPN or enteral nutrition (control) for 7 days. IEL-derived interleukin-10 (IL-10) was then measured. A significant decline in IEL-derived IL-10 expression was seen with TPN administration, a cytokine that has been shown in vitro to maintain tight junction integrity. We hypothesized that this change in IEL-derived IL-10 expression could contribute to TPN-associated barrier loss. An additional group of mice was given exogenous recombinant IL-10. Ussing chamber experiments showed that EBF markedly declined in the TPN group. TPN resulted in a significant decrease of IEL-derived IL-10 expression. The expression of several tight junction molecules also decreased with TPN administration. Exogenous IL-10 administration in TPN mice significantly attenuated the TPN-associated decline in zonula occludens (ZO)-1, E-cadherin, and occludin expression, as well as a loss of intestinal barrier function. TPN administration led to a marked decline in IEL-derived IL-10 expression. This decline was coincident with a loss of intestinal EBF. As the decline was partially attenuated with the administration of exogenous IL-10, our findings suggest that loss of IL-10 may be a contributing mechanism to TPN-associated epithelial barrier loss.


Sign in / Sign up

Export Citation Format

Share Document