• Title/Summary/Keyword: mucosal barrier

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Berberine Prevents Intestinal Mucosal Barrier Damage During Early Phase of Sepsis in Rat through the Toll-Like Receptors Signaling Pathway

  • Li, Guo-Xun;Wang, Xi-Mo;Jiang, Tao;Gong, Jian-Feng;Niu, Ling-Ying;Li, Ning
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.1
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    • pp.1-7
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    • 2015
  • Our previous study has shown berberine prevents damage to the intestinal mucosal barrier during early phase of sepsis in rat through mechanisms independent of the NOD-like receptors signaling pathway. In this study, we explored the regulatory effects of berberine on Toll-like receptors during the intestinal mucosal damaging process in rats. Male Sprague-Dawlay (SD) rats were treated with berberine for 5 d before undergoing cecal ligation and puncture (CLP) to induce polymicrobial sepsis. The expression of Toll-like receptor 2 (TLR 2), TLR 4, TLR 9, the activity of nuclear factor-kappa B ($NF-{\kappa}B$), the levels of selected cytokines and chemokines, percentage of cell death in intestinal epithelial cells, and mucosal permeability were investigated at 0, 2, 6, 12 and 24 h after CLP. Results showed that the tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) level were significantly lower in berberine-treated rats compared to the control animals. Conversely, the expression level of tight junction proteins, percentage of cell death in intestinal epithelial cells and the mucosal permeability were significantly higher in berberine-treated rats. The mRNA expression of TLR 2, TLR 4, and TLR 9 were significantly affected by berberine treatment. Our results indicate that pretreatment with berberine attenuates tissue injury and protects the intestinal mucosal barrier in early phase of sepsis and this may possibly have been mediated through the TLRs pathway.

Contributions of HO-1-Dependent MAPK to Regulating Intestinal Barrier Disruption

  • Zhang, Zhenling;Zhang, Qiuping;Li, Fang;Xin, Yi;Duan, Zhijun
    • Biomolecules & Therapeutics
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    • v.29 no.2
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    • pp.175-183
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    • 2021
  • The mitogen-activated protein kinase (MAPK) pathway controls intestinal epithelial barrier permeability by regulating tight junctions (TJs) and epithelial cells damage. Heme oxygenase-1 (HO-1) and carbon monoxide (CO) protect the intestinal epithelial barrier function, but the molecular mechanism is not yet clarified. MAPK activation and barrier permeability were studied using monolayers of Caco-2 cells treated with tissue necrosis factor α (TNF-α) transfected with FUGW-HO-1 or pLKO.1-sh-HO-1 plasmid. Intestinal mucosal barrier permeability and MAPK activation were also investigated using carbon tetrachloride (CCl4) administration with CoPP (a HO-1 inducer), ZnPP (a HO-1 inhibitor), CO releasing molecule 2 (CORM-2), or inactived-CORM-2-treated wild-type mice and mice with HO-1 deficiency in intestinal epithelial cells. TNF-α increased epithelial TJ disruption and cleaved caspase-3 expression, induced ERK, p38, and JNK phosphorylation. In addition, HO-1 blocked TNF-α-induced increase in epithelial TJs disruption, cleaved caspase-3 expression, as well as ERK, p38, and JNK phosphorylation in an HO-1-dependent manner. CoPP and CORM-2 directly ameliorated intestinal mucosal injury, attenuated TJ disruption and cleaved caspase-3 expression, and inhibited epithelial ERK, p38, and JNK phosphorylation after chronic CCl4 injection. Conversely, ZnPP completely reversed these effects. Furthermore, mice with intestinal epithelial HO-1 deficient exhibited a robust increase in mucosal TJs disruption, cleaved caspase-3 expression, and MAPKs activation as compared to the control group mice. These data demonstrated that HO-1-dependent MAPK signaling inhibition preserves the intestinal mucosal barrier integrity by abrogating TJ dysregulation and epithelial cell damage. The differential targeting of gut HO-1-MAPK axis leads to improved intestinal disease therapy.

Local Immunity of Pediatric Adenoid with Allergic Rhinitis & Sinusitis (알레르기 비염 및 부비동염에 의한 아데노이드의 국소 면역에 대한 고찰)

  • Yeo, Seung-Geun;Park, Dong-Choon;Hong, Chang-Kee;Sim, Ju-Sup;Cha, Chang-Il
    • IMMUNE NETWORK
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    • v.7 no.2
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    • pp.87-94
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    • 2007
  • Background: Chronic rhino-sinusitis and persistent allergic rhinitis is often cited as risk factor for developing adenoid hypertrophy or adenoiditis, but this relationship has not been studied extensively. In this study, we evaluated the mucosal barrier, squamous changes of ciliated epithelium, IgA secretion and BCL-6 expression in adenoids, and adenoid size. Methods: Six children with allergic rhinitis and sinusitis, nine children with only allergic rhinitis, nine children with only sinusitis and six children without any history of allergic rhinitis and sinusitis were enrolled. H-E stain of adenoid for squamous metaplasia, immunohistochemical study of adenoid for IgA and BCL-6, cytokeratin stain for evaluation of mucosal barrier and lateral view X-ray for adenoid size were performed. ANOVA test was used in the analysis and data showing p value of less than 0.05 were considered significant. Results: The number of ciliated cells had tendency to be decreased and squamous metaplasia had tendency to be increased in three experimental groups (p>0.05). Deterioration of mucosal barrier had tendency to be detected in three experimental groups than control group (p>0.05). BCL-6 had tendency to be increased and IgA secretion had tendency to be decreased in three experimental groups (p>0.05). There is no difference in adenoid size between three experimental groups and control group. Conclusion: Despite the expectation that adenoid would be affectecd by allergic rhinitis and rhino-sinusitis, we found no evidence for influence of adenoid immunity.

Heat stress on microbiota composition, barrier integrity, and nutrient transport in gut, production performance, and its amelioration in farm animals

  • Patra, Amlan Kumar;Kar, Indrajit
    • Journal of Animal Science and Technology
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    • v.63 no.2
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    • pp.211-247
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    • 2021
  • Livestock species experience several stresses, particularly weaning, transportation, overproduction, crowding, temperature, and diseases in their life. Heat stress (HS) is one of the most stressors, which is encountered in livestock production systems throughout the world, especially in the tropical regions and is likely to be intensified due to global rise in environmental temperature. The gut has emerged as one of the major target organs affected by HS. The alpha- and beta-diversity of gut microbiota composition are altered due to heat exposure to animals with greater colonization of pathogenic microbiota groups. HS also induces several changes in the gut including damages of microstructures of the mucosal epithelia, increased oxidative insults, reduced immunity, and increased permeability of the gut to toxins and pathogens. Vulnerability of the intestinal barrier integrity leads to invasion of pathogenic microbes and translocation of antigens to the blood circulations, which ultimately may cause systematic inflammations and immune responses. Moreover, digestion of nutrients in the guts may be impaired due to reduced enzymatic activity in the digesta, reduced surface areas for absorption and injury to the mucosal structure and altered expressions of the nutrient transport proteins and genes. The systematic hormonal changes due to HS along with alterations in immune and inflammatory responses often cause reduced feed intake and production performance in livestock and poultry. The altered microbiome likely orchestrates to the hosts for various relevant biological phenomena occurring in the body, but the exact mechanisms how functional communications occur between the microbiota and HS responses are yet to be elucidated. This review aims to discuss the effects of HS on microbiota composition, mucosal structure, oxidant-antioxidant balance mechanism, immunity, and barrier integrity in the gut, and production performance of farm animals along with the dietary ameliorations of HS. Also, this review attempts to explain the mechanisms how these biological responses are affected by HS.

A Comparative Study of Pyeongwi-san, Ijin-tang and Pyeongjintang Extracts on Indomethacin-Induced Gastric Mucosal Lesions in Mice (Indomethacin으로 유발된 생쥐의 위점막 손상에 대한 평위산(平胃散), 이진탕(二陳湯) 및 평진탕(平陳湯)의 비교연구)

  • Ji, Hyeon-Chyol;Baek, Tae-Hyeun
    • The Journal of Korean Medicine
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    • v.32 no.2
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    • pp.102-117
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    • 2011
  • Objectives: This study was performed to investigate the protective and treating efficacy of Pyeongwi-san, Ijin-tang, and Pyeongjin-tang extracts to the mice with gastric mucosal lesions induced from indomethacin. Methods: In order to verify protective and treating efficacy of Pyeongwi-san, Ijin-tang, and Pyeongjin-tang extracts to the mice with gastric mucosal lesions induced from indomethacin, I administered the extracts of these prescriptions to three group, and induced gastric mucosal lesion by indomethacin, and then I observed the gastric mucosal morphology of stomach, changes from stress resulting from HSP70, changes of gastro-protection (mucous barrier, COX-1). After I observed the anti-oxidant effect, and anti-inflammation effect (IKK mRNA, iNOS mRNA, COX-2 mRNA) in vitro, I induced gastric mucosal lesion by indomethacin, and administered the extracts of each prescriptions to three group, and then I observed the gastric mucosal morphology, anti-inflammation effect to mucosa (NF-${\kappa}$B, iNOS, COX-2) in vivo. Results & Conclusions: 1. Hemorrhagic erosion and damaged mucus secreting cell, positive responses to HSP70 were decreased in all the before-gastric-mucosal-lesion-induced groups, compared to non-extract administered group. The effects were good in the order of Pyeongwi-san extracts administered group, Pyeongjin-tang extracts administered group and Ijin-tang extracts administered group. 2. In all the before-gastric-mucosal-lesion-induced groups, gastro- protection functions (mucous barrier, COX-1) were significant. The effects were good in the order of Pyeongwi-san extracts administered group, Pyeongjin-tang extracts administered group and Ijin-tang extracts administered group. 3. Anti-oxidant effect was significant in Pyeongwi-san extracts, Ijin-tang extracts and Pyeongjin-tang extracts. The effects were good in the order of Pyeongjin-tang extracts, Pyeongwi-san extracts and Ijin-tang extracts. 4. The anti-inflammation effects in vitro were good in Pyeongwi-san extracts, Ijin-tang extracts and Pyeongjin-tang extracts. Especially Pyeongjin-tang extracts showed the most prominent results. Damaged mucus secreting cells and the positive reactions of NF-${\kappa}$B, iNOS, COX-2 in vivo were decreased in after-gastric-mucosal-lesion-induced groups compared to non-extract administered group. The effects were good in the order of Pyeongjin-tang extracts administered group, Pyeongwi-san extracts administered group and Ijin-tang extracts administered group. These results show that Pyeongwi-san, Ijin-tang and Pyeongjin-tang are effective on both in protecting and treating the gastric mucosal membrane. Pyeongwi-san is more effective than other prescriptions, in protecting gastric mucosal membrane, and Pyeongjin-tang is more effective in treating gastric mucosal lesion.

Development of adjuvant for effective oral vaccine application (경구백신의 효율적인 적용을 위한 면역 보조제 개발)

  • Kim, Sae-Hae;Seo, Ki-Weon;Kim, Ju;Jang, Yong-Suk
    • Journal of Plant Biotechnology
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    • v.37 no.3
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    • pp.283-291
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    • 2010
  • Vaccine is one of the best known and most successful applications of immunological theory to human health and it protects human life through inducing the immune response in systemic compartment. However, when we consider the fact that mucosal epithelium is exposed to diverse foreign materials including viruses, bacteria, and food antigens and protects body from entry of unwanted materials using layer of tightly joined epithelial cells, establishing the immunological barrier on the lining of mucosal surfaces is believed to be an effective strategy to protect body from unwanted antigens. Unfortunately, however, oral mucosal site, which is considered as the best target to induce mucosal immune response due to application convenience, is prone to induce immune tolerance rather than immune stimulation. Since intestinal epithelium is tightly organized, a prerequisite for successful mucosal vaccination is delivery of antigen to mucosal immune induction site including a complex system of highly specialized cells such as M cells. Consequently, development of efficient mucosal adjuvant capable of introducing antigens to mucosal immune induction site and overcome oral tolerance is an important subject in oral vaccine development. In this review, various approaches on the development of oral mucosal adjuvants being suggested for effective oral mucosal immune induction.

Pathophysiology and protective approaches of gut injury in critical illness

  • Jung, Chang Yeon;Bae, Jung Min
    • Journal of Yeungnam Medical Science
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    • v.38 no.1
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    • pp.27-33
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    • 2021
  • The gut is a complex organ that has played an important role in digestion, absorption, endocrine functions, and immunity. The gut mucosal barriers consist of the immunologic barrier and nonimmunologic barrier. During critical illnesses, the gut is susceptible to injury due to the induction of intestinal hyperpermeability. Gut hyperpermeability and barrier dysfunction may lead to systemic inflammatory response syndrome. Additionally, gut microbiota are altered during critical illnesses. The etiology of such microbiome alterations in critical illnesses is multifactorial. The interaction or systemic host defense modulation between distant organs and the gut microbiome is increasingly studied in disease research. No treatment modality exists to significantly enhance the gut epithelial integrity, permeability, or mucus layer in critically ill patients. However, multiple helpful approaches including clinical and preclinical strategies exist. Enteral nutrition is associated with an increased mucosal barrier in animal and human studies. The trophic effects of enteral nutrition might help to maintain the intestinal physiology, prevent atrophy of gut villi, reduce intestinal permeability, and protect against ischemia-reperfusion injury. The microbiome approach such as the use of probiotics, fecal microbial transplantation, and selective decontamination of the digestive tract has been suggested. However, its evidence does not have a high quality. To promote rapid hypertrophy of the small bowel, various factors have been reported, including the epidermal growth factor, membrane permeant inhibitor of myosin light chain kinase, mucus surrogate, pharmacologic vagus nerve agonist, immune-enhancing diet, and glucagon-like peptide-2 as preclinical strategies. However, the evidence remains unclear.

Gut Microbiota in Inflammatory Bowel Disease

  • Shim, Jung Ok
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.16 no.1
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    • pp.17-21
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    • 2013
  • The gut mucosal barrier plays an important role in maintaining a delicate immune homeostasis. The pathogenesis of inflammatory bowel disease (IBD) is considered to involve a defective mucosal immunity along with a genetic predisposition. Recent views have suggested an excessive response to components of the gut microbiota in IBD. A condition of "dysbiosis", with alterations of the gut microbial composition, has been observed in patients with IBD. In this article, the author review recent studies of gut microbiota in IBD, particularly the importance of the gut microbiota in the pathogenesis of pediatric IBD.

Physiological understanding of host-microbial pathogen interactions in the gut

  • Lee, Sei-Jung;Choi, Sang Ho;Han, Ho Jae
    • Korean Journal of Veterinary Research
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    • v.56 no.2
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    • pp.57-66
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    • 2016
  • The gut epithelial barrier, which is composed of the mucosal layer and the intestinal epithelium, has multiple defense mechanisms and interconnected regulatory mechanisms against enteric microbial pathogens. However, many bacterial pathogens have highly evolved infectious stratagems that manipulate mucin production, epithelial cell-cell junctions, cell death, and cell turnover to promote their replication and pathogenicity in the gut epithelial barrier. In this review, we focus on current knowledge about how bacterial pathogens regulate mucin levels to circumvent the epithelial mucus barrier and target cell-cell junctions to invade deeper tissues and increase their colonization. We also describe how bacterial pathogens manipulate various modes of epithelial cell death to facilitate bacterial dissemination and virulence effects. Finally, we discuss recent investigating how bacterial pathogens regulate epithelial cell turnover and intestinal stem cell populations to modulate intestinal epithelium homeostasis.

The American Cockroach Peptide Periplanetasin-2 Blocks Clostridium Difficile Toxin A-Induced Cell Damage and Inflammation in the Gut

  • Hong, Ji;Zhang, Peng;Yoon, I Na;Hwang, Jae Sam;Kang, Jin Ku;Kim, Ho
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.694-700
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    • 2017
  • Clostridium difficile, which causes pseudomembranous colitis, releases toxin A and toxin B. These toxins are considered to be the main causative agents for the disease pathogenesis, and their expression is associated with a marked increase of apoptosis in mucosal epithelial cells. Colonic epithelial cells are believed to form a physical barrier between the lumen and the submucosa, and abnormally increased mucosal epithelial cell apoptosis is considered to be an initial step in gut inflammation responses. Therefore, one approach to treating pseudomembranous colitis would be to develop agents that block the mucosal epithelial cell apoptosis caused by toxin A, thus restoring barrier function and curing inflammatory responses in the gut. We recently isolated an antimicrobial peptide, Periplanetasin-2 (Peri-2, YPCKLNLKLGKVPFH) from the American cockroach, whose extracts have shown great potential for clinical use. Here, we assessed whether Peri-2 could inhibit the cell toxicity and inflammation caused by C. difficile toxin A. Indeed, in human colonocyte HT29 cells, Peri-2 inhibited the toxin A-induced decrease in cell proliferation and ameliorated the cell apoptosis induced by this toxin. Moreover, in the toxin A-induced mouse enteritis model, Peri-2 blocked the mucosal disruption and inflammatory response caused by toxin A. These results suggest that the American cockroach peptide Peri-2 could be a possible drug candidate for addressing the pseudomembranous colitis caused by C. difficile toxin A.