• Molecules and Cells
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• v.24 no.2
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• pp.167-176
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• 2007

Peroxisome proliferator-activated receptor-gamma ($PPAR{\gamma}$) is expressed at very high levels in the gastrointestinal epithelium. Many of the functions of $PPAR{\gamma}$ in gastrointestinal epithelial cells have been elucidated in recent years, and a pattern is emerging which suggests that this receptor plays an important role in gastrointestinal physiology. There is also strong evidence that $PPAR{\gamma}$ is a colon cancer suppressor in pre-clinical rodent models of sporadic colon cancer, and there is considerable interest in exploitation of $PPAR{\gamma}$ agonists as prophylactic or chemopreventive agents in colon cancer. Studies in mice and in human colon cancer cell lines suggest several mechanisms that might account for the tumor suppressive effects of $PPAR{\gamma}$ agonists, although it is not in all cases clear whether these effects are altogether mediated by $PPAR{\gamma}$. Conversely, several reports suggest that $PPAR{\gamma}$ agonists may promote colon cancer under certain circumstances. This possibility warrants considerable attention since several million individuals with type II diabetes are currently taking $PPAR{\gamma}$ agonists. This review will focus on recent data related to four critical questions: what is the physiological function of $PPAR{\gamma}$ in gastrointestinal epithelial cells; how does $PPAR{\gamma}$ suppress colon carcinogenesis; is $PPAR{\gamma}$ a tumor promoter; and what is the future of $PPAR{\gamma}$ in colon cancer prevention?

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.289-297
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• 2002

The regional distribution and relative frequency of neurohormonal peptides-producing cells were demonstrated in the gut of the stomach teleost, the Mandarin fish, Siniperca scherzeri Steindachner, using 7 types of specific antisera raised against mammalian regulatory peptides. The gastrointestinal tract of the Mandarin fish was divided into three portions from proximal to distal, stomach, small intestine and large intestine. Cells showing immunoreactivities against regulatory peptides were situated in the epithelial lining, between epithelial cells, and gastric or intestinal gland regions with various frequencies along with gastrointestinal tract. Mast of immunoreactive cells in the epithelial lining portion were generally spherical or spindle shape having long cytoplasmic process that were reached to the lumen (open type cell) while cells showing round in shape (closed type cell) were found in the gastric gland of the stomach occasionally. Serctonin-, samatostatin-, gastrin-, cholecystokinin (CCK)-8- and human pancreatic polypeptide (HPP)-immunoreactive cells were observed in this study. However, no insulin- and glucagon-immunoreactive cells were found. Serotonin- and somatostatin-immunoreactive cells were restricted to the stomach regions with moderate and numerous frequencies, respectively. Gastrin-immunoreactive cells were demonstrated in the stomach and small intestinal portions with a few and moderate frequencies, respectively and CCK-8-immunoreactive cells were restricted to the small intestinal portions with moderate frequency. In addition, HPP-immunoreactive cells were demonstrated in the stomach and small intestine with numerous frequencies, respectively. In conclusion, the distribution and relative frequency of these immunoreactive cells in the gastrointestinal tract of the Mandarin fish shows peculiar patterns compared to those of other stomach and/or stomachless teleost.

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.597-603
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• 1993

The purpose of this stady was to investigate division cells by in vivo bromodeoxyuridine(Brdur) immunohistochemistry for labeling the proliferative epithelial cells in the gastrointestinal tracts of rats. Rats were administrated intraperitonially by twice consecutive injections of 24 hr interval with Brdur(0.05mg/g BW/time) and then were sacrificied at 1 hour after last injection. The specimens were taken from the stomach, small intestine(ileum), and large intestine(colon). The well-oriented crypts and villi in the preparations were examined, The crypt columns and villi were devided into 10 segments from crypt base to surface of the lumen or to villis top. Labeling index(LI) was measured by counting the number of Brdur-positive cells against the total number of crypt column cells in the stomach and large intestine and also against the total numbers of crypt column and it's villi epiterial cells in the small intestine. 1. In the stomach, the LI in each part from segment 1 to segment 10 of the crypt column were 4.2%, 5.0%. 6.6%, 9.0%, 11.3%, 15.3%, 9.3%, 15.6%, 11.3%, 0%, respectively and it's mean LI were 8.7%. The Brdur-positive epithelial cells were predominantly located in the middle regions and middle-upper regions of the crypt columns. 2. In the small intestine, the LI in each part from segment 1 to segment 10 of were 62.4%, 50.9%, 27.8%, 22.5%, 18.6%, 12.1%, 7.5%, 4.3%, 2.5%, 1.4%, respectively and it's mean LI were 21.0%. The Brdur-positive epithelial cells were predominantly located in the lower regions of the crypt columns and tended to be less in the higher regions of the villi than that in the crypt column. 3. In the large intestine, the LI in each part from segment 1 to segment 10 of the crypt column were 19.4%, 29.9%, 34.1%, 41.6%, 41.2%, 32.4%, 25.4%, 15.4%, 10.8%, 1.2%, respectively and it's mean LI were 25.1%, The Brdur-positive epithelial cells were predominantly in the middle and middle-lower regions of the crypt columns. 4. The organs with higher LI were ordered as the large intestine(25.1%), small intestine(21.0%) and stomach(8.7%).

• Development and Reproduction
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• v.23 no.4
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• pp.305-311
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• 2019

Small intestine has a structure called villi that increases the mucosal surface area for nutrient absorption. Intricate and tight epithelial-mesenchymal interactions are required for villi development. These interactions are regulated by signaling molecules, physical forces, and epithelial deformation. Signaling molecules include hedgehog (Hh), bone morphogenetic protein (BMP) and Wnt ligands. The Hh ligand is expressed from the epithelium and binds to the underlying mesenchymal cells, resulting in aggregation into mesenchymal clusters. The clusters express BMP and Wnt ligands to control its size and spacing between clusters. The clusters then form villi. Despite the fact that the villi formation is studied extensively, we do not have a complete understanding. In addition, the recent study shows there is a great relationship between the overexpression of the Hh signal and development of cancer in the gastrointestinal tract. Therefore, signaling between epithelial and mesenchymal cells and their physical interactions will be discussed on this review.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.12-19
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• 1999

The regional distributions and relative frequencies of the gastrin, secretin and pancreatic polypeptide(PP)-immunoreactive cells in the gastrointestinal tract of the fetus(180 days of gestation) of Korean native goat were studied with immunohistochemical(ABC) methods. Gastrin-immunoreactive cells were detected in fundus, pylorus and duodenum and these cells were most predominant in pylorus. Secretin-immunoreactive cells were observed in pylorus, duodenum and ileum. PP-immunoreactive cells were restricted to fundus. These immunoreactive cells were situated in surface epithelium and mucosal gland regions. The regional distribution and relative frequency of PP-immunoreactive cells was somewhat different to the adult Korean native goat. Immunoreactive cells in the surface epithelial regions were open typed cells which were spindle shaped cells but closed typed cells which were round or/to spherical shaped cells were observed in the mucosal gland regions.

• Journal of Environmental Science International
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• v.31 no.1
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• pp.23-31
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• 2022

As a herbal supplement, Dioscorea batatas Decne (DBD) presents potent antioxidant activity and diverse health benefits. In the present study, functions of a 30 kDa glycoprotein isolated from DBD (hereafter, DBD glycoprotein) in the regulation of feed efficiency and fecal malodor in mice were explored. DBD glycoprotein produced protective effect against cytotoxicity induced by the ecotoxicological endocrine-disrupting substance bisphenol A in gastrointestinal epithelial HT-29 cells. To investigate its potential roles in the regulation of feed efficiency and fecal malodor, mice were administered an oral injection of DBD glycoprotein for 2 weeks. Compared with the control values, the weight of internal organs (liver, heart, kidney, and spleen) and levels of glutamate pyruvate transaminase, glutamate oxaloacetate transaminase, and lactic dehydrogenase were not significantly changed during DBD glycoprotein administration for 2 weeks. Interestingly, DBD glycoprotein improved feed efficiency and reduced hydrogen sulfide concentration without altering the ammonia level in mouse feces. Collectively, these results indicate that DBD glycoprotein is a functional agent that exerts gastrointestinal protective effects against ecotoxicological substances, improves feed efficiency, and reduces fecal malodor.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.333-339
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• 1992

The regional distribution and relative frequency of occurrence of endocrine cells in nine segments of the gastrointestinal(GI) tract of snakehead(Ophicephalus argus) were investigated by immunohistochemical methods using specific antisera against 5- hydroxyptrytamine(5-HT), somatostatin, gastrin/cholecystokinin(GAS/CCK), glucagon, bovine chromogranin, porcine chromogranin and insulin. Four types of immunoreactive cells for 5-HT, somatostatin, GAS/CCK and glucagon were observed in the GI tract. These cells were generally appeared in the mucosal epithelia or located at the interface of the mucosal epithelial layer and intestinal glandular region. 5-HT-immunoreactive(IR) cells were found in segment II, III, IV, V and VI, and the most numerous in segment IV. Somatostatin-IR cells were found in segment II, III, IV and V, and the most numerous in segment III. GAS/CCK-IR cells in segment VI, VII and glucagon-IR cells in segment III, IV, V were detected but a few in these segments. No bovine chromogranin-, porcine chromogranin- and insulin-IR cells were detected throughout the GI tract of the snakehead.

• IMMUNE NETWORK
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• v.15 no.1
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• pp.44-49
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• 2015

Interactions between microbes and epithelial cells in the gastrointestinal tract are closely associated with regulation of intestinal mucosal immune responses. Recent studies have highlighted the modulation of mucosal immunity by microbe-derived molecules such as ATP and short-chain fatty acids. In this study, we undertook to characterize the expression of the ATP-gated $P2X_7$ receptor ($P2X_7R$) on M cells and its role in gastrointestinal mucosal immune regulation because it was poorly characterized in Peyer's patches, although purinergic signaling via $P2X_7R$ and luminal ATP have been considered to play an important role in the gastrointestinal tract. Here, we present the first report on the expression of $P2X_7R$ on M cells and characterize the role of $P2X_7R$ in immune enhancement by ATP or LL-37.

• Journal of Gastric Cancer
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• v.21 no.4
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• pp.439-456
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• 2021

Purpose: Gastric cancer (GC) has high morbidity and mortality and is a serious threat to public health. The flavonoid compound vitexin is known to exhibit anti-tumor activity. In this study, we explored the therapeutic potential of vitexin in GC and its underlying mechanism. Materials and Methods: The viability, migration, and invasion of GC cells were determined using MTT, scratch wound healing, and transwell assays, respectively. Target molecule expression was determined by western blotting. Tumor growth and liver metastasis were evaluated in vivo using nude mice. Protein expression in the tumor tissues was examined by immunohistochemistry. Results: Vitexin inhibited GC cell viability, migration, invasion, and epithelial-mesenchymal transition (EMT) in a dose-dependent manner. Vitexin treatment led to the inactivation of phosphatidylinositol-3-kinase (PI3K)/AKT/hypoxia-inducible factor-1α (HIF-1α) pathway by repressing HMGB1 expression. Vitexin-mediated inhibition in proliferation, migration, invasion and EMT of GC cells were counteracted by hyper-activation of PI3K/AKT/HIF-1α pathway or HMGB1 overexpression. Finally, vitexin inhibited the xenograft tumor growth and liver metastasis in vivo by suppressing HMGB1 expression. Conclusions: Vitexin inhibited the malignant progression of GC in vitro and in vivo by suppressing HMGB1-mediated activation of PI3K/Akt/HIF-1α signaling pathway. Thus, vitexin may serve as a promising therapeutic agent for the treatment of GC.

• The Korea Journal of Herbology
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• v.38 no.1
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• pp.21-30
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• 2023

Objective : Gardeniae Fructus (GF) has bitter and cold nature. Thus, it has been traditionally prescribed in processed form roasted with ginger juice for patients with a weak stomach. This study investigated the effects of processed GF in tert-butyl hydroperoxide (tBHP)-treated gastric epithelial cells. Methods : Processed GF was made by applying 40% ginger juice or 10% ethanol for 24 h and then roasting at 150℃ for 5 minutes. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Mitochondrial membrane potential (MMP) was monitored by flow cytometry using the membrane permeable fluorescent dye Rh123. Protein expression was measured by Western blot analysis. Results : Cell viability was reduced by tBHP and restored by ethanol extract of GF (GFE). In the TUNEL assay, it was found that cell death by tBHP was due to apoptosis, and GFE had an anti-apoptotic effect. Processed GF roasted with ginger juice showed the best anti-apoptotic effect. Processed GF also inhibited MMP loss and restored tBHP-induced changes in expression levels of apoptosis-related proteins. Increased ROS production and GSH depletion after tBHP treatment were significantly reduced by processed GF. In addition, tBHP-induced activation of mitogen-activated protein kinase (MAPK) was inhibited by processed GF. Conclusion : These results demonstrate that the processed GF is able to protect gastric epithelial cells from oxidative stress-induced cell death with antiapoptotic and antioxidant activity. In addition, it shows that the processing of GF, which have been traditionally used for gastrointestinal protection, partially have scientific validity.