• Applied Microscopy
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• 제26권3호
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• pp.293-303
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• 1996

This paper aims to probe that the effect of high dose of cyclophosphamide to the Sertoli cells of the mouse was examined by transmission electron microscope. In the normal group, Sertoli cells contact each other around the basal aspect of the seminiferous tubule, forming numerous row of tight junction, blood-testis barrier. Sertoli cells contain smooth endoplasmic reticulum, well developed Golgi comples, a number of round mitochondria and microfilament. The cytoplasmic necrosis are observed from the 1-time treated group. In the 2-times treated group, smooth endoplasmic reticulum are more developed than normal group, but cisternae are partially dilated. In the 3-times treated group, the smooth endoplasmic reticulum are not developed. In the 2-times treated group, the inner membrane of the mitochondria are partially disrupted, and cristae are all disrupted in the 3-times treated group. The microfilaments are not observed in the all treated groups. According to the results above, it seems that smooth endoplasmic reticulum, mitochondria, and microfilament are disrupted by toxic effects of the cyclosphamide to the Sertoli cells of the mouse.

• 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.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권1호
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• pp.51-56
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• 1999

This paper presents a new transient overvoltage blocking device (TOBD) for info-communication facilities with low power and high frequency bandwidth. Conventional protection devices have some problems such as low frequency bandwidth, low energy capacity and high remnant voltage. In order to improve these limitations, thehybrid type TOBD, which consists of a gas tube, avalanche diodes and junction typefield effect transistors (JFETs), was designed and fabricated. The TOBD differs from the conventional protection devices in configuration, and JFETs were used as an active non-linear element and a high speed switching diode with low capacitance limits high current. Therefore the avalanche dilde with low energy capacity are protected fromthe high current, and the TOBD has a very small input capacitance. From the performance test using combination surge generator, which can produce $1.2/50\mus\;4.2kV_{max}\; 8/20\mus\; 2.1kA_{max}$, it is confirmed that proposed TOBD has an excellent protection performance in tight clamping voltage and limiting current characteristics.

• Reproductive and Developmental Biology
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• 제40권2호
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• pp.23-26
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• 2016

Transcription factor called activating enhancer binding protein 2C (AP2-gamma) is found in a variety of species and expressed from oocyte stage onwards, particularly restricted to the trophectoderm. Recent studies demonstrated that ablation of Tfap2c led to failure of tight junction biogenesis, particularly the knock-down embryos of Tfap2c did not form cavity from morula to blastocyst in mouse and pig. We speculated that the Tfa2pc may also be involved in desmosome biogenesis because blastocoel formation is coincident with the establishment of desmosome. To determine this, we depleted Tfap2c injecting siRNA into one-cell zygote and analysed the expression levels of genes that are required for desmosome complex such as PkP2, Pkp3, Dsc2, and Dsg2. We found only Pkp3 was up-regulated in the knockdowned morula embryos. Interestingly, upstream region of Pkp3 had putative Tfap2c binding sites. In conclusion, our results suggest that Tfap2c is not a crucial factor but somehow it might be involved in desmosome biogenesis directly or indirectly via Pkp3.

• 대한수의학회지
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• 제56권2호
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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.

• 한국발생생물학회지:발생과생식
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• 제25권1호
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• pp.1-14
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• 2021

The Syrian (golden) hamsters are seasonal breeders whose reproductive functions are active in summer and inactive in winter. In experimental facility mimicking winter climate, short photoperiod (SP) induces gonadal regression. The blood-testis barrier (BTB) of the sexually involuted animals have been reported to be permeable, allowing developing germ cells to be engulfed or sloughed off the epithelium of the seminiferous tubules. The expressions of genes related to the tight junction composing of BTB were investigated in the reproductive active and inactive testes. Claudin-11, occludin, and junctional adhesion molecule (JAM) were definitely expressed in the active testes but not discernably detected in the inactive testes. And spermatozoa (sperm) were observed in the whole lengths of epididymides in the active testes. They were witnessed in only cauda region of the epididymides but not in caput and corpus regions in animals with the inactive testes. The results imply that the disorganization of BTB is associated with the testicular regression. The developing germ cells are swallowed into the Sertoli cells or travel into the lumen, as supported by the presence of the sperm delayed in the last region of the epididymis. These outcomes suggest that both apoptosis and desquamation are the processes that eliminate the germ cells during the regressing stage in the Syrian hamsters.

• Journal of Microbiology and Biotechnology
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• 제31권11호
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• pp.1568-1575
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• 2021

Obesity and related metabolic diseases are major problems worldwide. Some probiotics are currently considered potential therapeutic strategies for obesity. We aimed to investigate the anti-obesity efficacy of Latilactobacillus sakei WIKIM31 in obese mice induced by a high fat diet. The administration of a high-fat diet with L. sakei WIKIM31 reduced body weight gain, epididymal fat mass, triglyceride and total cholesterol levels in the blood, and remarkably decreased the expression of lipogenesis-related genes in the epididymal adipose tissue and liver. Interestingly, intake of L. sakei WIKIM31 improved gut barrier function by increasing the gene expression of tight junction proteins and suppressing the inflammatory responses. Additionally, L. sakei WIKIM31 enhanced the production of short-chain fatty acids, such as butyrate and propionate, in the intestinal tract. These results showed that L. sakei WIKIM31 can be used as a potential therapeutic probiotic for obesity.

• Applied Microscopy
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• 제16권2호
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• pp.1-13
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• 1986

The purpose of this study was to investigate the morphology and intercellular junctions of the odontoblast of dental pulp in the rat incisor by means of the freeze fracture electron microscopy. Twenty male Sprague-Dawley rats weighing $150{\sim}200g$ were used. After being anesthetized by an intraperitoneal injection of 0.5 ml sodium pentobarbital per kg in body weight(60 mg/ml) the animals were perfused with 2.5% glutaraldehyde-2% paraformaldehyde fixative in 0.1 M cacodylate buffer, pH 7.2 through the ascending aorta for one hour. The incisors were carefully extracted from the jaws and demineralized by suspending them in 0.1 M EDTA in 3% glutaraldehyde (pH 7.2) for two weeks. After demineralization, the specimens were obtained from the portion divided into five equal parts. For freeze-fracture replication, demineralized tissues were infiltrated for several hours with 10%, 25% glycerol in 0.1M cacodylate buffer as a cryoprotectant and then frozen in liquid Freon 22 and stored in liquid nitrogen. Fracturing and replication were done in Balzers BAF 400D high-vacuum freeze-fracture apparatus at $-120^{\circ}C$ under routine $5X10^{-7}$ Torr vacuum. The tissue was immediately replicated with platinum unidirectionally at $45^{\circ}$ angle and reinforced with carbon at $90^{\circ}$ angle unidirectionally or by using a rotary stage. The replication process was monitored by a quartz-crystal device. The replicas were immersed in 100% methanol overnight. The tissue was then digested from the replica by clorox (laundry bleach), placed into 5% EDTA, and washed repeatedly with distilled water. The replicas were picked up on 0.3% formvar-coated 75 mesh grids and examined in the JEOL 100B electron microscope. The results were as follows; 1. Both in thin sections and freeze-fracture replicas, three types of intercellular junctions were recognizable in the plasma membrane of odontoblast: gap junction, tight junction and desmosome-like junction. 2. The nuclear pores were evenly distributed over the nuclear envelope. The pore complex formed a ring about 70 nm in diameter. 3. Gap junctions were found between odontoblasts as well as odontoblasts and neighbouring pulp cells (fibroblast, subodontoblastic cell process, nerve-like fibre). Gap junctions, which were round, ellipsoid and pear-shaped and 600 nm in diameter, were observed in the odontoblast. 4. Numerous round and ellipsoid gap junctions could be frequently seen on the plasma membranes in cell body and apical part of the odontoblasts. On the P face, the junctions were recognized as a cluster of closely packed particles, measuring about 9 nm in diameter, and on the E face, the junctions were recognized as a shallow grooves.

• Applied Microscopy
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• 제31권2호
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• pp.157-165
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• 2001

정상 성인 고환의 버팀세포(Sertoli cell)는 비분열세포이며, 정세관(seminiferous tubule)단면에서 비교적 불분명하게 관찰되고, 정세관 세포 성분의 $10\sim15%$를 차지하고 있다. 전자현미경적으로 버팅 세포는 특징적인 핵소체와 원형질막 및 세포질 소기관을 갖고 있다. 원형질막은 사춘기에 발달한 두 종류 즉 버팅세포와 버팀세포 및 버팅세포와 생식세포 사이의 세포연접을 가지고 있다. 그러나 태이에서 버팅세포의 정확한 미세구조에 대한 기술은 드물다. 이에 본 저자는 태아 고환의 발생 제 14주부터 제27주 사이의 17예를 수집하여 정상 미세구조를 확인하고, 태아기 버팀세포의 분화 양상을 알아보고자 하였다. 태아기에서 버팀세포와 생식세포 및 버팀세포와 버팀세포 사이의 세포연접은 부착반점과 비슷한 구조로 이루어져 있었고, 이들은 관찰 대상인 태령 제14주부터 관찰되었다. 태아기 버팅세포의 세포소기관의 발달은 전반적으로 미약하였다. 비교적 풍부하게 사립체가 태령 제14주부터 관찰되었고, 무과립세포질세망이 소수, 그리고 과립세포질세망이 비교적 풍부하게 관찰되었다. 지방소포의 수는 비교적 일정하게 관찰되었고, 포도당입자는 발생 단계에 따라 점차 증가하는 소견을 보였다. 미세섬유와 Charcot-Bottcher의 결정소체는 본 연구대상에서는 관찰되지 않았다. 결론적으로, 태아기의 버팀세포에서는 어른에서 관찰되는 특징적인 소견들이 관찰되지 않았으며, 어른과는 다소 다른 전자현미경 소견을 나타냈다. 하지만 버팅세포의 분화양상을 정확히 알기 위해서는 태령 제27주 이후부터 사춘기까지의 연구가 추가되어야 할 것으로 생각한다.

• Journal of Gastric Cancer
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• 제20권4호
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• pp.408-420
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• 2020

Purpose: Isoform 2 of tight junction protein claudin-18 (CLDN18.2) is a potential target for gastric cancer treatment. A treatment targeting CLDN18.2 has shown promising results in gastric cancer. We investigated the clinical significance of CLDN18.2 and other cell-adherens junction molecules (Rho GTPase-activating protein [RhoGAP] and E-cadherin) in metastatic diffuse-type gastric cancer (mDGC). Materials and Methods: We evaluated CLDN18.2, RhoGAP, and E-cadherin expression using two-plex immunofluorescence and quantitative data analysis of H-scores of 77 consecutive mDGC patients who received first-line platinum-based chemotherapy between March 2015 and February 2017. Results: CLDN18.2 and E-cadherin expression was significantly lower in patients with peritoneal metastasis (PM) than those without PM at the time of diagnosis (P=0.010 and 0.013, respectively), whereas it was significantly higher in patients who never developed PM from diagnosis to death than in those who did (P=0.001 and 0.003, respectively). Meanwhile, CLDN18.2 and E-cadherin expression levels were significantly higher in patients with bone metastasis than in those without bone metastasis (P=0.010 and 0.001, respectively). Moreover, we identified a positive correlation between the expression of CLDN18.2 and E-cadherin (P<0.001), RhoGAP and CLDN18.2 (P=0.004), and RhoGAP and E-cadherin (P=0.001). Conversely, CLDN18.2, RhoGAP, and E-cadherin expression was not associated with chemotherapy response and survival. Conclusions: CLDN18.2 expression was reduced in patients with PM but significantly intact in those with bone metastasis. Furthermore, CLDN18.2 expression was positively correlated with other adherens junction molecules, which is clinically associated with mDGC and PM pathogenesis.