• International Journal of Stem Cells
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• v.17 no.3
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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.

• 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)

• International Journal of Stem Cells
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• v.17 no.1
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• pp.51-58
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• 2024

With the activity of intestinal stem cells and continuous turnover, the gut epithelium is one of the most dynamic tissues in animals. Due to its simple yet conserved tissue structure and enteric cell composition as well as advanced genetic and histologic techniques, Drosophila serves as a valuable model system for investigating the regulation of intestinal stem cells. The Drosophila gut epithelium is in constant contact with indigenous microbiota and encounters externally introduced "non-self" substances, including foodborne pathogens. Therefore, in addition to its role in digestion and nutrient absorption, another essential function of the gut epithelium is to control the expansion of microbes while maintaining its structural integrity, necessitating a tissue turnover process involving intestinal stem cell activity. As a result, the microbiome and pathogens serve as important factors in regulating intestinal tissue turnover. In this manuscript, I discuss crucial discoveries revealing the interaction between gut microbes and the host's innate immune system, closely associated with the regulation of intestinal stem cell proliferation and differentiation, ultimately contributing to epithelial homeostasis.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.200-210
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• 2002

Objectives: Dojeckjiyu-tang has been used to treat Hwaseol & Jeokri. The object of this study is examination of the treatment effect of Dojeckjiyu-tang for ulcerative colitis of the mouse descending colon. Methods and Materials : Twenty-one rats were divided into 3 groups and treated as follows: the control group was untreated mice. The UCE group was ulcerative colitis elicited mice. The DJT group was Dojeckjiyu-tang treated mice after ulcerative colitis elicitation. The groups were examined with common morphology, paneth cells in intestinal crypt, absorptive cells and goblet cells in epithelium, cell division in mucose, COX-1 as mucosal protector, COX-2 (which appears to play an important role in inflammation), IL-2R-, ICMA-1-inducing cellular immuno-chainreaction, and the distribution of apoptotic cells. Results: 1. The morphology of colonic mucosa from UCE mice: the disappearance of epithelium and intestinal propria in hemorrhagic erosions were seen, but in the morphology of colonic mucosa from DJT-treated mice, the configuration of epithelium and intestinal propria were the same as normal. 2. The distribution of goblet cells and absorptive cells with microvilli in intestinal propria from UCE mice: a noticeable decrease of goblet cells and absorptive cells with microvilli were seen, but with the distribution of goblet cells and absorptive cells with microvilli in intestinal propria from DJT -treated mice, the configuration of goblet cells and absorptive cells with microvilli were the same as normal. 3. The immunohistochemical stain for BrdD in colonic mucosa and COX-1 in lamina propria from UCE mice: BrdU positive cells and COX-1 positive cells in the region of hemorrhagic erosion disappeared, but in the immunohistochemical stain for BrdU in colonic mucosa and COX-1 in lamina propria from DIT-treated mice, BrdU positive cells and COX-1 positive cells were seen. 4. The immunohistochemical stain for COX-2 in lamina propria, IL-2R-in lamina propria, intestinal propria and submucosa and ICMA-1 in intestinal propria and submucosa from DCE mice: a noticeable increase COX-2, IL-2R-, ICMA-1 positive cells were seen, but in the immunohistochemical stain for COX-2 in lamina propria, IL-2R-in lamina propria, intestinal propria and submucosa and ICMA-1 in intestinal propria and submucosa from DJT-treated mice, a numerical decrease of COX-2, IL-2R-, ICMA-1 positive cells was observed. 5. The distribution of apoptotic cells in epithelium and lamina propria from UCE mice: a noticeable increase of apoptotic cells in region of hemorrhagic erosion was seen, but in the distribution of apoptotic cells in epithelium and lamina propria from DJT-treated mice, a remarkable decrease of apoptotic cells was seen. Conclusions: According to the above results, Dojeckjiyu-tang has a moderate effect on ulcerative colitis in descending colon.

• Herbal Formula Science
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• v.32 no.2
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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.

• IMMUNE NETWORK
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• v.15 no.1
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• pp.1-8
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• 2015

Innate immune cells survey antigenic materials beneath our body surfaces and provide a front-line response to internal and external danger signals. Dendritic cells (DCs), a subset of innate immune cells, are critical sentinels that perform multiple roles in immune responses, from acting as principal modulators to priming an adaptive immune response through antigen-specific signaling. In the gut, DCs meet exogenous, non-harmful food antigens as well as vast commensal microbes under steady-state conditions. In other instances, they must combat pathogenic microbes to prevent infections. In this review, we focus on the function of intestinal DCs in maintaining intestinal immune homeostasis. Specifically, we describe how intestinal DCs affect IgA production from B cells and influence the generation of unique subsets of T cell.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.350-355
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• 2004

Sulforhodamine B (SRB) assay is a rapid, sensitive, and inexpensive method for measuring cell proliferation and chemosensitivity. However, the lactate dehydrogenase (LDH) release assay is generally used to measure cytototoxicity of infectious microorganisms against host cells. In this study, we investigated the possibility of applying the SRB assay to determine cytotoxicity for infectious microorganisms, and compared the results with those obtained by the LDH release assay. We used Vibrio vulnificus as a model of infectious microorganisms. The SRB assay showed that V vulnificus strongly induced cytotoxic activity against human intestinal cells, Caco-2 and INT-407 cells. The degree of cytotoxicity closely correlated with infection time and number ratios of V. vulnificus to intestinal cells (MOI, multiplicity of infection). Furthermore, cytotoxicity values obtained by SRB assay correlated well with results obtained by the LDH release assay, and both assays gave a linear response with respect to MOI Heat-inactivation of V. vulnificus for 35 min at $60^{\circ}C$ did not induce cytotoxic activity, indicating that viability of V. vulnificus is crucial for cytotoxic activity against intestinal cells. Although both assays are suitable as cytotoxicity endpoints, the SRB assay is recommended for measuring cytotoxicity of infectious microorganisms against host cells because of its significantly lower cost and more stable endpoint than the LDH release assay.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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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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• v.15 no.1
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• pp.104-111
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• 2022

Many of early findings regarding intestinal stem cells (ISCs) and their niche in the human intestine have relied on colorectal cancer cell lines and labor-intensive and time-consuming mouse models. However, these models cannot accurately recapitulate the physiologically relevant aspects of human ISCs. In this study, we demonstrate a reliable and robust culture method for 3D expanding intestinal spheroids (InS^exp) mainly comprising ISCs and progenitors, which can be derived from 3D human intestinal organoids (HIOs). We did functional chararcterization of InS^exp derived from 3D HIOs, differentiated from human pluripotent stem cells, and optimization culture methods. Our results indicate that InS^exp can be rapidly expanded and easily passaged, and show enhanced growth rates via WNT pathway activation. InS^exp are capable of exponential cell expansion and cryopreservation. Furthermore, in vitro-matured HIO-derived InS^exp proliferate faster than immature HIO-derived InS^exp with preservation of the parental HIO characteristics. These findings may facilitate the development of scalable culture systems for the long-term maintenance of human ISCs and provide an alternative platform for studying ISC biology.

• International Journal of Industrial Entomology and Biomaterials
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• v.43 no.2
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• pp.94-98
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• 2021

Reactive oxygen species (ROS) induce a variety of cellular responses, such as proliferation, differentiation, senescence, and apoptosis. Intestinal epithelial cells are continuously exposed to ROS, and excessive generation of ROS severely damages cells via oxidative stress. Pro-inflammatory cytokines may lead to intestinal inflammation and damage by inducing excessive ROS generation. In this study, we showed that papiliocin, an antimicrobial peptide, significantly inhibited ROS production, without affecting cell viability. Moreover, TNF-α and IL-6 expression was decreased in the intestinal epithelial cells. The activity of papiliocin may significantly contribute to preserving the integrity of the intestinal mucosa against oxidative damage and inflammation-related disorders.