• Proceedings of the PSK Conference
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• 2003.10b
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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)

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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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 Environmental Science International
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• v.28 no.2
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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.

• Nutrition Research and Practice
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• v.9 no.2
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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.

• The Journal of the Korean Society for Microbiology
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• v.34 no.5
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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.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1292-1300
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• 2006

Aeromonas encheleia, a potential human intestinal pathogen, was shown to infect a human intestinal epithelial cell line (Caco-2) in a noninvasive manner. The transcriptional profile of the Caco-2 cells after infection with the bacteria revealed an upregulated expression of genes involved in chloride secretion, including that of phospholipase A2 (PLA2) and platelet-activating factor (PAF) acetylhydrolase (PAFAH2). This was also confirmed by a real-time RT-PCR analysis. As expected from PLA2 induction, PAF was produced when the Caco-2 cells were infected with the bacteria, and PAF was also produced when the cells were treated with a bacterial culture supernatant including bacterial extracellular proteins, yet lacking lipopolysaccharides. Bacterial aerolysin was shown to induce the production of PAF.

• Natural Product Sciences
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• v.15 no.4
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• pp.185-191
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• 2009

Intestinal epithelial cells (IEC) play an important role in the mucosal immune system. IEC-derived mediators of inflammatory cascades play a principal role in the development of colon inflammation. The aim of this study was to investigate the inhibitory effect of aqueous extracts of Schizandra chinensis fruits (SC-Ex) on the production of inflammatory mediators by the human colonic epithelial cells. HT-29 cells were stimulated with dextran sulfate sodium in the presence or absence of SC-Ex to examine the cytoprotection and production of IL-8 and reactive oxygen species (ROS). It was shown that dextran sulfate sodium (DSS) caused the reduction of cell viability and production of IL-8 and ROS in DSS-treated HT-29 cells. We observed that the treatment of SC-Ex protected significantly cell proliferation from DSS-induced damage in dose-dependent manner. SC-Ex (10 and 100 ${\mu}g$/ml) also suppressed DSS-induced production of IL-8 mRNA and protein. Moreover, DSS-induced ROS production was inhibited markedly by the treatment of 100 ${\mu}g$/ml SC-Ex. These results suggest that SC-Ex has the protective effects on DSS-induced cell damage and the release of inflammatory mediators in the intestinal epithelial cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.881-887
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• 2012

This study was designed to examine influence of bacteria and herbal applications of Lonicerae Flos on the permeability of intestinal epithelial cells. The HCT-116 human intestinal cell was used as an in vivo model of "leaky gut". Dextran sodium sulphate (DSS) was used to induce an increase in the permeability of epithelial cell tight junctions. Probiotics including Lactobacillus acidophilus, Lactobacillus plantarum, Salomonella spp. and Staphylococcus aureus were used to evaluate bacterial influence on the intestinal epithelial cells. Herbal extract Lonicerae Flos was also assessed to find out what kind of effects it has when used alone or fermented with Lactobacillus plantarum. The permeability of intestinal cell lines was assessed using transepithelial electrical resistance (TEER) and horseradish peroxide (HRP) assessments. This data provides evidence for the probiotic benefits of intestinal permeability. The data also provides promising evidence of herbal effects on reducing intestinal permeability, especially when fermented with probiotics.

• BMB Reports
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• v.45 no.8
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• pp.433-441
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• 2012

Human milk, which nourishes the early infants, is a source of bioactive components for the infant growth, development and commensal formulation as well. Human milk oligosaccharide is a group of complex and diverse glycans that is apparently not absorbed in human gastrointestinal tract. Although most mammalian milk contains oligosaccharides, oligosaccharides in human milk exhibit unique features in terms of their types, amounts, sizes, and functionalities. In addition to the prevention of infectious bacteria and the development of early immune system, human milk oligosaccharides are able to facilitate the healthy intestinal microbiota. Bifidobacterial intestinal microbiota appears to be established by the unilateral interaction between milk oligosaccharides, human intestinal activity and commensals. Digestibility, membrane transportation and catabolic activity by bacteria and intestinal epithelial cells, all of which are linked to the structural of human milk oligosaccharides, are crucial in determining intestinal microbiota.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.616-630
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• 2023

BACKGROUND/OBJECTIVES: Indole-3-propionic acid (IPA) is a tryptophan-derived microbial metabolite that has been associated with protective effects against inflammatory and metabolic diseases. However, there is a lack of knowledge regarding the effects of IPA under physiological conditions and at the intestinal level. MATERIALS/METHODS: Human intestinal epithelial Caco-2 cells were treated for 2, 24, and/or 72 h with IPA or its precursors - indole, tryptophan, and propionate - at 1, 10, 100, 250, or 500 μM to assess cell viability, integrity, differentiation, and proliferation. RESULTS: IPA induced cell proliferation and this effect was associated with a higher expression of extracellular signal-regulated kinase 2 (ERK2) and a lower expression of c-Jun. Although indole and propionate also induced cell proliferation, this involved ERK2 and c-Jun independent mechanisms. On the other hand, both tryptophan and propionate increased cell integrity and reduced the expression of claudin-1, whereas propionate decreased cell differentiation. CONCLUSIONS: In conclusion, these findings suggested that IPA and its precursors distinctly contribute to the proliferation, differentiation, and barrier function properties of human intestinal epithelial cells. Moreover, the pro-proliferative effect of IPA in intestinal epithelial cells was not explained by its precursors and is rather related to its whole chemical structure. Maintaining IPA at physiological levels, e.g., through IPA-producing commensal bacteria, may be important to preserve the integrity of the intestinal barrier and play an integral role in maintaining metabolic homeostasis.