• 대한한의학방제학회지
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• 제32권2호
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• pp.111-120
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• 2024

Objectives : Intestinal epithelial cell damage is closely associated with various intestinal diseases, such as Inflammatory Bowel Disease (IBD), Celiac Disease and Gastroenteritis, and it plays a crucial role in the development and progression of intestinal diseases. Therefore, it is important to develop drugs that target protection of intestinal epithelial cells. Here, we aimed to investigated whether Bambusae Caulis in Liquamen (BCL) against t-BHP induced oxidative stress injury in human intestinal epithelial cells and to explore the underlying molecular mechanism. Methods : In this study, we performed MTT assay, measurement of ROS generation, and immunoblot analysis to determine the cytoprotective efficacy in HT29 cells (human colorectal adenocarinoma cell line with epithelial morphogy). Results : First, we checked that BCL was not cytotoxic up to concentration 30 ㎍/mL in HT29 cells. Then, we confirmed that BCL inhibited t-BHP-induced ROS and cell death. BCL also reversed the expression of proteins associated apoptosis. Next, to confirm the relationship between efficacy of BCL and Nrf2, we conducted experiments using siNrf2. Asresult, the effects of inhibiting ROS production and cell death of BCL was reversed by siNrf2. Conclusion : BCL prevents t-BHP-induced oxidative stress and apoptosis. And the efficacy of BCL is related to Nrf2 activation.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.132.2-132.2
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• 2003

Vibrio vulnificus, a Gram-negative estuarine bacterium, is the causative agent of food-borne diseases, such as life-threatening septicemia. V. vulnificus penetrating into the intestinal epithelial barrier stimulates an inflammatory response in the adjacent intestinal mucosa. Therefore, interaction between V. vulnificus and intestinal cells is important for understanding of both the immunology of mucosal surfaces and V. vulnificus. In this study we investigated the effects of V. vulnificus infection on cytokine gene expression of human intestinal epithelial cells, Caco-2 and INT-407 cells. (omitted)

• 대한미생물학회지
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• 제34권5호
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• pp.479-489
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• 1999

Invasion of enteric bacteria, such as Salmonella and invasive E. coli, into intestinal epithelial cells induces proinflammatory gene responses and finally epithelial cell apoptosis. In this study, we asked whether invasive bacterial infection of human intestinal epithelial cells could upregulate cyclooxygenase-2 (COX-2) gene expression and whether increased COX-2 expression could influence intestinal epithelial cell apoptosis. Expression of COX-2 mRNA and prostaglandin (PG) $E_2$ production were upregulated in HT-29 colon epithelial cells which were infected with S. dublin or invasive E. coli, as examined by quantitative RT-PCR and radioimmunoassay. Inhibition of COX-2 expression and $PGE_2$ production using NS-398, a specific COX-2 inhibitor, showed a significant increase of epithelial cell apoptosis and caspase-3 activation in HT-29 cells infected with invasive bacteria. However, the addition of valerylsalicylate, a specific COX-1 inhibitor, did not change apoptosis in S. dublin-infected HT-29 cells. These results suggest that up regulated COX-2 expression and $PGE_2$ production in response to invasive bacterial infection could contribute to host defense by inhibiting apoptosis of intestinal epithelial cells.

• Biomolecules & Therapeutics
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• 제29권2호
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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.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.479-491
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• 2015

Lactobacillus species have been shown to enhance intestinal epithelial barrier function, modulate host immune responses, and suppress the growth of pathogenic bacteria, yeasts, molds, and viruses. Thus, lactobacilli have been used as probiotics for treating various diseases, including intestinal disorders, and as biological preservatives in the food and agricultural industries. However, the molecular mechanisms used by lactobacilli to suppress pathogenic bacterial infections have been poorly characterized. We previously isolated Lactobacillus plantarum JSA22 from buckwheat sokseongjang, a traditional Korean fermented soybean food, which possessed high enzymatic, fibrinolytic, and broad-spectrum antimicrobial activity against foodborne pathogens. In this study, we investigated the effects of L. plantarum JSA22 on the growth of S. Typhimurium and S. Typhimurium-induced cytotoxicity by stimulating the host immune response in intestinal epithelial cells. The results showed that coincubation of S. Typhimurium and L. plantarum JSA22 with intestinal epithelial cells suppressed S. Typhimurium infection, S. Typhimurium-induced NF-κB activation, and IL-8 production, and lowered the phosphorylation of both Akt and p38. These data indicated that L. plantarum JSA22 has probiotic properties, and can inhibit S. Typhimurium infection of intestinal epithelial cells. Our findings can be used to develop therapeutic and prophylactic agents against pathogenic bacteria.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1309-1316
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• 2023

To exert their beneficial effects, it is essential for the commensal bacteria of probiotic supplements to be sufficiently protected as they pass through the low pH environment of the stomach, and effectively colonize the intestinal epithelium downstream. Here, we investigated the effect of a multilayer coating containing red ginseng dietary fiber, on the acid tolerance, and the adhesion and proliferation capacities of three Lactobacillus strains (Limosilactobacillus reuteri KGC1901, Lacticaseibacillus casei KGC1201, Limosilactobacillus fermentum KGC1601) isolated from Panax ginseng, using HT-29 cells, mucin-coated plates, and human pluripotent stem cell-derived intestinal epithelial cells as in vitro models of human gut physiology. We observed that the multilayer-coated strains displayed improved survival rates after passage through gastric juice, as well as high adhesion and proliferation capacities within the various gut epithelial systems tested, compared to their uncoated counterparts. Our findings demonstrated that the multilayer coat effectively protected commensal microbiota and led to improved adhesion and colonization of intestinal epithelial cells, and consequently to higher probiotic efficacy.

• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1175-1182
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• 2021

We investigated the effect of bovine lactoferricin (Lfcin-B), a peptide derived from bovine lactoferrin, on activation of intestinal epithelial cells in IEC-6 intestinal cell, and protection against in vivo rotavirus (RV) infection. Treatment with Lfcin-B significantly enhanced the growth of IEC-6 cells and increased their capacity for attachment and spreading in culture plates. Also, Lfcin-B synergistically augmented the binding of IEC-6 cells to laminin, a component of the extracellular matrix (ECM). In the analysis of the intracellular mechanism related to Lfcin-B-induced activation of IEC-6 cells, this peptide upregulated tyrosine-dependent phosphorylation of focal adhesion kinase (FAK) and paxillin, which are intracellular proteins associated with cell adhesion, spreading, and signal transduction during cell activation. An experiment using synthetic peptides with various sequences of amino acids revealed that a sequence of 9 amino acids (FKCRRWQWR) corresponding to 17-25 of the N-terminus of Lfcin-B is responsible for the epithelial cell activation. In an in vivo experiment, treatment with Lfcin-B one day before RV infection effectively prevented RV-induced diarrhea and significantly reduced RV titers in the bowels of infected mice. These results suggest that Lfcin-B plays meaningful roles in the maintenance and repair of intestinal mucosal tissues, as well as in protecting against intestinal infection by RV. Collectively, Lfcin-B is a promising candidate with potential applications in drugs or functional foods beneficial for intestinal health and mucosal immunity.

• International Journal of Stem Cells
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• 제17권3호
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• pp.213-223
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• 2024

Tissue-specific adult stem cells are pivotal in maintaining tissue homeostasis, especially in the rapidly renewing intestinal epithelium. At the heart of this process are leucine-rich repeat-containing G protein-coupled receptor 5-expressing crypt base columnar cells (CBCs) that differentiate into various intestinal epithelial cells. However, while these CBCs are vital for tissue turnover, they are vulnerable to cytotoxic agents. Recent advances indicate that alternative stem cell sources drive the epithelial regeneration post-injury. Techniques like lineage tracing and single-cell RNA sequencing, combined with in vitro organoid systems, highlight the remarkable cellular adaptability of the intestinal epithelium during repair. These regenerative responses are mediated by the reactivation of conserved stem cells, predominantly quiescent stem cells and revival stem cells. With focus on these cells, this review unpacks underlying mechanisms governing intestinal regeneration and explores their potential clinical applications.

• Nutrition Research and Practice
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• 제9권2호
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• pp.117-122
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• 2015

BACKGROUND/OBJECTIVES: Curcumin, a major component of the Curcuma species, contains antioxidant and anti-inflammatory properties. Although it was found to induce apoptosis in cancer cells, the functional role of curcumin as well as its molecular mechanism in anti-inflammatory response, particularly in intestinal cells, has been less investigated. The intestine epithelial barrier is the first barrier and the most important location for the substrate coming from the lumen of the gut. SUBJECTS/METHODS: We administered curcumin treatment in the human intestinal epithelial cell lines, T84 and Caco-2. We examined endoplasmic reticulum (ER) stress response by thapsigargin, qPCR of XBP1 and BiP, electrophysiology by wild-type cholera toxin in the cells. RESULTS: In this study, we showed that curcumin treatment reduces ER stress and thereby decreases inflammatory response in human intestinal epithelial cells. In addition, curcumin confers protection without damaging the membrane tight junction or actin skeleton change in intestine epithelial cells. Therefore, curcumin treatment protects the gut from bacterial invasion via reduction of ER stress and anti-inflammatory response in intestinal epithelial cells. CONCLUSIONS: Taken together, our data demonstrate the important role of curcumin in protecting the intestine by modulating ER stress and inflammatory response post intoxication.

• 한국환경과학회지
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• 제28권2호
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• pp.249-257
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• 2019

Ulmus davidiana Nakai (UDN) has been traditionally used as a herbal medicine to treat inflammatory diseases in Korea. In the present study, we investigated the anti-ecotoxic potential of a 116 kDa glycoprotein isolated from UDN (UDN glycoprotein) in human intestinal epithelial INT-407 cells. We demonstrated that UDN glycoprotein ($20{\mu}g/mL$) could inhibit the production of lactate dehydrogenase (LDH) induced by toluene, an ecotoxic substance. Additionally, we found that the toluene-induced intestinal cytotoxicity was mediated by the phosphorylation of p38 Mitogen-Activated Protein Kinase (MAPK) via the production of intracellular Reactive Oxygen Species (ROS). The UDN glycoprotein significantly decreased the levels of ROS production and p38 MAPK activation in toluene-stimulated INT-407 cells. Moreover, the UDN glycoprotein inhibits the phosphorylation of nuclear factor-kappa B ($NF-{\kappa}B$), which is responsible for the production of LDH, in toluene-stimulated INT-407 cells. Collectively, our data indicate that UDN glycoprotein is a natural antioxidant and a modulator of ecotoxicity signaling pathways in human intestinal epithelial cells.