• Reproductive and Developmental Biology
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• 제28권3호
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• pp.147-153
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• 2004

The oocyte and its surrounding granulosa cells co-exist in a closed compartment called a follicle, although they receive many signals from other parts of the body. It is well established that the intercellular communications between the oocyte and granulosa cells are required for normal oocyte development and ovulation during folliculogenesis. Gap junctions are intercellular channels allowing the direct transmission of ions and small molecules between coupled cells. Several lines of studies have shown that multiple connexins (Cx, subunits of gap junction) are expressed in mammalian ovarian follicles. Among them, two major connexins Cx37 and Cx43 are expressed in different manner. While the gap junction channels formed by Cx37 are localized between the oocyte and encompassing granulosa cells, the intercellular channels by Cx43 are located between granulosa cells. In this review, I will summarize the general properties of gap junction channels and discuss their possible formation (or compatibility) of intercellular channels formed by the oocyte and granulosa cells.

• 생명과학회지
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• 제14권5호
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• pp.882-890
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• 2004

간극결합(gap junction)은 이웃하는 두 세포사이에 형성된 막 구조물로 이를 통하여 각종 이온들과 여러 가지 분자들이 통과한다. 일반적으로 알려진 세포의 이온채널(예를 들어 $Na^{+}$ 이온채널과$K^+$이온채널)과 구별하여 두 세포사이에 형성된 간극결합을 세포간 채널(intercellular channel)이라고도 부른다. 간극결합채널(gap junction channel)은 단순히 수동적으로 열려있는 통로가 아니라 여러 가지 자극 즉 pH, 칼슘이온(calcium ion), 전압(voltage), 그리고 화학적인 변형(주로 인산화, phosphorylation)에 의해서 개폐(gating, opening and closing)가 조절되는 이온채널이다. 그 가운데서도 전압에 의한 간극결합채널 개폐 변화가 가장 많이 연구되었다. 세포안과 바깥에 형성된 전압차이(membrane potential, $V_m$) 보다는 주로 두 세포 사이에 형성된 전압차이(transjunctional voltage, $V_j$)에 의해서 간극결합채널은 민감하게 반응한다. 본 총설에서는 간극결합채널의 일반적인 특성을 정리해보고 전압-의존적인(voltage-dependent) 채널개폐에 관한 기전을 논의하고자 한다.

• Journal of Ginseng Research
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• 제30권2호
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• pp.64-69
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• 2006

Gap junctional channels, allowing rapid intercellular communication and synchronization of coupled cell activities, play crucial roles in many signaling processes, including a variety of cell activities. Consequently, a modulation of the gap junctional intercellular communication (GJIC) should be a potential pharmacological target. In the present, the GJIC of a epithelial-derived rat mammary cells (BICR-M1Rk) was assessed in the presence of ginseng saponin, by using an established method of scrape-loading dye transfer assay. The transfer of Lucifer yellow (diameter: 1.2 nm) among the neighboring BICR-M1Rk cells, in which connexin43 (Cx43) is a major gap junction channel-forming protein, was significantly retarded at a concentration of $10{\mu}g/ml$ ginseng saponin. By using both methods of RT-PCR and Western blotting, it was demonstrated that ginseng saponin modulated neither the mRNA synthesis of Cx43 nor the translational process of Cx43. This ginseng saponin-induced modification of GJIC was a similar phenomenon observed under the $\beta$-glycyrrhetinic acid treatment, a well-known gap junction channel blocker. Taken together, it is reasonable to conclude that the ginseng saponin inhibits GJIC only by modulating the gating property of gap junction channels.

• Archives of Pharmacal Research
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• 제19권4호
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• pp.264-268
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• 1996

Panax-ginseng saponin has been known to exert various pharmacological effects on cellular metabolism. This study was performed to determine the effect of ginseng saponin on gap junction channel-mediated intercellular communication, using an established in vitro system of reconstituted gap junction channels. Gap junction channels are a specialized plasma membrane fraction, which are permeable to relatively large water-soluble molecules. The sucrose permeable property of reconstituted gap junction channels was completely inhibited with 0.1 % (w/v) of ginseng saponin. We also compared the effect of ginseng saponin with that of Triton X-100, a nonionic detergent, on the same system. Triton X-100 showed significantly different effect on sucrose-permeability of gap junction channel from that was affected by ginseng saponin. The structures of liposomes containing gap junction channels was significantly destroyed by Triton X-100.

• Journal of Microbiology and Biotechnology
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• 제21권5호
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• pp.477-482
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• 2011

There are accumulating evidences suggesting that connexin (Cx), a gap junction channel-forming protein, acts as a growth suppressor in various cancer cells, and this effect is attributeed to the gap junction-mediated intercellular communication (GJIC). In order to characterize the relationship between the growth-arresting activity of Cx26 and its cytoplasmic localizations after expression, we linked a nuclear export signal (NES) sequence to Cx26 cDNA before transfecting into a rat breast cancer cell line. A confocal fluorescent microscopic observation revealed that the insertion of NES minimized the nuclear expression of Cx26, and increased its cytoplasmic expression, including plasma membrane junctions. Total cell counting and BrdUrd-labeling experiments showed that the growth of the breast cancer cells was inhibited by 74% upon transfection of Cx26-NES, whereas only 9% inhibition was observed with only Cx26 cDNA.

• 생명과학회지
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• 제17권11호
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• pp.1517-1522
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• 2007

간극결합(intercellular channel)은 인접하는 두 세포사이에 형성된 이온채널이며 이를 통해서 각종 이온, 이차 신호전달물질, 그리고 1 kDa 미만의 대사물질들이 통과한다. 아울러, sodium 혹은 potassium 이온채널처럼 반쪽의 간극결합(connexon 혹은 hemichannel)도 세포막채널로서 작용을 한다. 현재까지 간극결합을 구성하는 connexin (Cx) 단위체는 26종류 이상이 확인되었다. 이 가운데, Cx32, Cx38, Cx46 그리고 Cx50 만이 간극결합채널뿐만 아니라 세포막채널로서도 기능을 수행한다. Xenopus oocytes에서 connexin 38 (Cx38)이 발현하는 것으로 알려져 있지만 Cx38의 생물리학적 특성이 단일채널수준에서 연구가 진행된 경우는 없다. 이번 연구에서는 Cx38 채널의 생물리학적 특성, 즉 전압-의존적 개폐와 투과성(전기전도도와 이온선택성)을 알아보고자 단일채널기록을 수행하였다. Cx38 hemichannel은 전압-의존적인 빠른 개폐와 느린 개폐의 특성을 보였다. 양성전압 환경에서는 Cx38 채널이 낮은 열릴 확률(open probability)로 빠른 개폐가 유도된 반면, 음성전압에서는 느린 개폐가 높은 열릴 확률로 유도되었다. bi-ionic 실험을 통하여, Cx38 채널은 양이온보다 음이온을 더 선택 적으로 통과시킨다는 점을 알게 되었다. Cx38의 아미노산서열을 살펴보면, 아미노말단부위에 전하를 띠는 5개의 아미노산 잔기가 존재한다. 앞으로 이들 잔기를 치환시킨 돌연변이 Cx38 채널을 이용하여 과연 이들 아미노산 부위가 전압-의존적 개폐와 투과성에 관여하는 지 여부를 조사하는 연구는 매우 흥미로운 결과를 도출할 것으로 기대한다.

• 생명과학회지
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• 제34권6호
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• pp.426-433
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• 2024

식물이 가장 쉽게 노출되는 환경적 위험은 수분 스트레스이다. Abscisic acid (ABA)는 환경 스트레스에 적응하기 위해 식물에서 생성되는 식물 호르몬이다. 식물에서 기공의 가장 중요한 역할은 광합성 활성에 크게 영향을 주는 CO₂를 흡수하여 슈크로스의 합성을 활발하게 유도하는 것이다. 또한 기공은 증산작용을 통해 H₂O를 방출하는 통로이며, 식물의 뿌리가 토양에서 물과 무기 물질을 지속적으로 흡수할 수 있도록 수분퍼텐셜의 기울기를 형성하는 기능을 한다. 식물은 수분 스트레스 환경에 노출되면, 기공을 닫아 수분 손실을 최소화하는 메커니즘을 가진다. 환경에 따른 기공 닫힘 메커니즘들과 관련하여 가장 잘 밝혀진 가설은 수분 스트레스에 대한 기공 반응이다. 식물이 충분한 수분을 공급받은 상태일 때, 기공은 일주기 리듬에 따라 낮에는 열리고 밤에는 닫힌다. 또한 세포간극 안에 CO₂ 농도가 증가하면 기공이 닫힌다. 그러나 일주기 리듬과 세포간극 안의 CO₂ 농도 증가로 인한 기공 닫힘 메커니즘은 명확하게 알려져 있지 않다. 식물이 수분 스트레스에 놓이면, 공변세포 세포질의 ABA 농도 증가는 동일한 세포질 내에 Ca²⁺ 농도 증가를 유도하여 원형질막에서 탈분극이 발생한다. 그 결과, 액포막에 있는 외향성 K⁺-채널과 느린 음이온 채널들인 SLAC1, SLAH3가 활성화되어 K⁺, Cl^-, 그리고 malate^2-를 방출하여 기공이 닫히는 것으로 알려져 있다. 따라서 본 논문은 수분 스트레스로 인한 기공 닫힘 메커니즘에 대하여 조사하였다.

• Korean Journal of Acupuncture
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• 제35권4호
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• pp.187-202
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• 2018

Objectives : Non-invasive transcranial electrical stimulation is one of therapeutic interventions to change in neural excitability of the cortex. Transcranial electro-acupuncture (TEA) can modulate brain functions through changes in cortical excitability as a model of non-invasive transcranial electrical stimulation. Some composites of fermented Scutellaria baicalenis (FSB) can activate intercellular signaling pathways for activation of brain-derived neurotrophic factor that is critical for formation of neural plasticity in stroke patients. This study was aimed at evaluation of combinatory treatment of TEA and FSB on behavior recovery and cortical neural excitability in rodent focal stroke model. Methods : Focal ischemic stroke was induced by photothrombotic injury to the motor cortex of adult rats. Application of TEA with 20 Hz and $200{\mu}A$ in combination with daily oral treatment of FBS was given to stroke animals for 3 weeks. Motor recovery was evaluated by rotating bean test and ladder working test. Electrical activity of cortical pyramidal neurons of stroke model was evaluated by using multi-channel extracellular recording technique and thallium autometallography. Results : Compared with control stroke group who did not receive any treatment, Combination of TEA and FSB treatment resulted in more rapid recovery of forelimb movement following focal stroke. This combination treatment also elicited increase in spontaneous firing rate of putative pyramidal neurons. Furthermore expression of metabolic marker for neural excitability was upregulated in peri-infract area under thallium autometallography. Conclusions : These results suggest that combination treatment of TEA and FSB can be a possible remedy for motor recovery in focal stroke.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제47권2호
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• pp.91-98
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• 2021

Objectives: Hyaluronoglucosaminidase (hyaluronidase) increases the local intercellular permeability of the peripheral lymphatic channel and capillaries, which may help reduce edema. In the present study, the effects of hyaluronidase on postoperative edema and pain reduction were evaluated. Materials and Methods: The study included 38 patients who underwent guided bone regeneration (GBR) surgery before implantation. Patients were randomly assigned to either the control group (n=20) or the test group (n=18). Hyaluronidase was injected into the GBR site of subjects in the test group. Postoperative edema was evaluated by measuring the distance between specific facial landmarks immediately after surgery (T1) and 2-4 days after surgery (T2). The degree of pain at T2 and at 10-14 days after surgery (T3) was assessed. Results: In the test group, the degree of swelling was lower than in the control group, however, only two measurements, from the tragus to the mouth corner and from the outer canthus to the mouth corner, showed statistically significant differences (P=0.012 and P=0.001, respectively). The anti-edema effect of hyaluronidase was more effective in the maxilla than in the mandible. In the maxilla, the percentage of facial swelling was significant for three measurements. However, in the mandible, the percentage of facial swelling was significant for only one measurement. Low levels of pain that were similar at T2 and T3 were reported in both groups. Conclusion: The results indicate the degree of swelling was lower in the test group and hyaluronidase appeared to be more effective in the maxilla. The degree of pain reduction was similar between groups. Further in vivo and randomized controlled trials with larger sample sizes are warranted.