• 제목/요약/키워드: Tight-junction

검색결과 149건 처리시간 0.034초

정보통신기기용 과도전압 차단장치의 개발에 관한 연구 (A Study on the Development of a Transient Voltage Blocking Device for Info-communication Facilities)

  • 한주순
    • Journal of Advanced Marine Engineering and Technology
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    • 제23권2호
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    • pp.159-167
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    • 1999
  • This paper presents a new transient voltage blocking device(TOBD)which low power and high frequency bandwidth to protect info-communication facilities from transient voltages. Conventional protection devices have some problems such as low frequency bandwidth low ener-gy capacity and high remnant voltage. in order to improve these limitations a hybrid type TOBD which consists of a gas tube avalanche diodes and junction type field effect transistor (JFETs) is developed. The TOBD differs from the conventional protection devices in configuration and JFETs are used as an active non-linear element and a high speed switching diode with low capacitance limited high current. Therefore the avalanche diode with low energy capacity are protected from the high current and the TOBD has a very small input capacitance. From the performance test using combination surge generator which can produce $1.2/50{\mu}m$ 4.2 kV/max, $8/20{\mu}m$ 2.1 kAmax it is confirmed that the proposed TOBD has an excellent protection per-formance in tight clamping voltage and limiting current characteristics.

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쥐의 뇌 미세혈관 내피세포를 이용한 뇌혈관장벽 내피세포의 배양과 특성 (Primary Culture and Characteristics of Blood-Brain Barrier Endothelial Cells from Rat Brain Microvessel)

  • 이희상;김석중;김대진;정윤희;김성수;이원복;김경용
    • Applied Microscopy
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    • 제35권4호
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    • pp.55-63
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    • 2005
  • 쥐의 뇌로부터 미세혈관에서 분리하고 배양한 내피세포의 특성을 현미경관찰, 면역염색과 전기저항을 측정해 관찰하였다. 미세혈관 내피세포는 배양 후 $5{\sim}6$일 경에 단층을 형성하였으며 특징적으로 소용돌이치는 모양을 나타냈다. 내피세포 단층의 전기저항은 배양 후 5일 경까지 따라 증가하였고 이후로는 감소하였다. 면역형광염색에서 anti-GFAP, anti-GalC, anti-neurofilament 160/200 kD antibody에 대한 면역반응을 거의 찾아볼 수 없었어 별아교세포, 희소돌기아교세포 및 신경세포에 의한 우려할 만한 오염은 배제할 수 있었다. vWF 항원에 대한 면역반응은 내피세포의 세포질에 Weibel-Palade 과립이 전반적으로 퍼져 있었다. 치밀이음부를 구성하는 occludin, ZO-1, ZO-2에 대한 면역반응은 내피세포의 접촉부위에서 매우 특징적으로 나타나고 있었다. 요약하면 쥐의 뇌 미세혈관 내피세포를 분리, 배양하여 형태학적, 조직면역 화학적 방법과 전기저항을 측정하여 내피세포의 특성을 확인하였다. 이 생체외 혈액뇌장벽 모델은 앞으로 진행될 액뇌장벽의 특징을 규명하고자 하는 시험관내 실험에 유용하게 이용될 수 있을 것이다.

생강계피 복합물이 장내 유익균 증식 및 염증조절 기능에 미치는 영향 (Effect of ginger and cinnamon extract mixtures on the growth of intestinal bacteria and intestinal inflammation)

  • 김민주;김민서;강성태;김지연
    • Journal of Applied Biological Chemistry
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    • 제60권4호
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    • pp.321-326
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    • 2017
  • 본 연구에서 생강과 계피 추출물 및 복합물의 장내 개선 효능을 조사하였다. 생강계피 복합물을 Modified EG 액체배지에 처리하고 대표적인 유익균인 B. longum, Lactobacillus sp.와 L. acidophilus 균주를 접종하여 생육 활성을 관찰하였다. 그리고 사람의 장상피세포인 Caco-2 cell과 마우스의 대식세포인 RAW 264.7을 co-culture한 model에서 생강계피 복합물을 처리한 후 lipopolysaccharide (LPS)로 자극시켜 Transepithelial electrical resistance (TEER), permeability 그리고 nitrite 생성량을 확인하였다. 그 결과, 생강계피 복합물을 생강 : 계피 1:5로 처리 시, B. longum, Lactobacillus sp. 및 L. acidophilus 세 가지 균주의 성장을 모두 최대로 상승시켜 생육 활성 효과가 우수하였다. 특히 생강계피 복합물은 대조군에 비해 Lactobacillus sp. 균주의 가장 높은 생육 상승을 나타내어 생강계피 복합물에 젖산균의 생육인자를 함유할 것으로 추정된다. 반면 장 염증활성 조절을 확인하기 위한 co-culture model에서는, LPS 처리군과 비교하여, 생강계피 복합물 처리군 중 생강 : 계피 1 : 1, 1 : 3, 1 : 5와 1 : 7 복합물이 대조군과 비슷하거나 더 높게 증가하였고, tight junction(TJ) permeability는 생강 : 계피 3 : 1, 1 : 1, 1 : 3과 1 : 5 복합물에서 대조군과 비슷하게 감소하였다. 또한, 생강: 계피 1 : 1, 1 : 5와 1 : 7 복합물은 nitrite의 수준을 감소시켰다. 장내 유익균의 생육 및 장 염증 억제 활성 결과를 종합하여 볼 때 생강계피 복합물 중 생강 : 계피 1 : 5 복합물이 장내 유익균과 염증 조절에 좋은 효과를 나타내는 최적 복합비율이라고 판단할 수 있다.

마치현 추출물 함유 제제 KDC16-2의 생리 활성 효과 (Bioactive effects of a Herbal Formula KDC16-2 Consisting Portulaca oleracea L. Extracts)

  • 허가영;이소영;김연용;장현재;이승재;이승웅;최정호;노문철
    • 생약학회지
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    • 제50권1호
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    • pp.37-45
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    • 2019
  • Portulaca oleracea L. (PL) has been used in traditional medicine herb for treatment of various diseases, such as diarrhea, dysentery, and skin inflammation. Previous studies have shown that the PL regulates the inflammation by inhibition of pro-inflammatory cytokines. Although PL might have improvement effects of intestinal function and bioactive effects, there are not enough studies to demonstrate. This study investigated the effects of KDC16-2 on the improvement of intestinal function and anti-inflammatory effects in vivo and in vitro. The improvement effect of intestinal function was measured fecal amount, water content and intestinal transit rate in KDC16-2 treated ICR mice. As results, compared with the control group, the KDC16-2 group showed a significant increase in wet fecal weight, dry fecal weight and fecal water content. The intestinal transit rate of KDC16-2 group was significantly increased. Based on the results, KDC16-2 is considered to have effects on improving intestinal function. The effect of anti-inflammatory demonstrated by using dextran sulfate sodium (DSS)-induced colitis mice. The mice were administered 3% DSS along with KDC16-2 (100, 300 mg/kg) for 14 days. DSS-induced colitis mice were significantly ameliorated in KDC16-2 treated group, including body weight loss, colon length shortening, tight junction protein of colon and histological colon injury. The levels of inflammatory mediators (IgG2a, IgA, C-reactive protein and Myeloperoxidase) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-${\alpha}$, Interleukin (IL)-6) which are involved in inflammatory responses were increased in the DSS-treated group as compared to those in the control group, and the levels were significantly decreased in the KDC16-2 groups. In addition, we investigated the impact of KDC16-2 on lipopolysaccharide (LPS)-induced inflammatory responses in J774A.1 cells. KDC16-2 inhibited production of prostaglandin E2 (PGE2) and reactive oxygen species (ROS). These results suggested that the KDC16-2 could effectively alleviate the dysfunction of intestinal and inflammatory mediators. Thus, these KDC16-2 can be potentially used as health functional food of intestinal.

허혈성 뇌졸중 모델에서 혈액-뇌 장벽에 보호효과를 나타내는 한약처방, 한약재 및 활성화합물 (Protective Effects of Traditional Korean Medicine Preparations, Herbs, and Active Compounds on the Blood-brain Barrier in Ischemic Stroke Models)

  • 신수빈;장석주;이나경;최병태;신화경
    • 생명과학회지
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    • 제32권7호
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    • pp.550-566
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    • 2022
  • 뇌졸중은 세계적으로 사망과 장기간인 신체적, 인지적 장애의 주요 원인들 중 하나이며, 매년 약 1,500만명의 사람들에게 영향을 미친다. 뇌졸중의 병태 생리학적 과정은 다수의 사건들이 관여하는 복잡한 과정으로, 그 중 혈액-뇌 장벽(blood-brain barrier: BBB)의 붕괴는 허혈성 뇌손상의 진행에 크게 기여하는 것으로 알려져 있다. 따라서 BBB 붕괴는 뇌졸중의 특징으로 인식되므로 허혈성 뇌졸중에서 BBB 기능 장애를 보호할 수 있는 새로운 치료 전략을 개발하는 것이 뇌졸중 치료에 매우 중요하다. 전통한약은 천연물로 구성되어 있으며, 이는 뇌졸중 치료약 개발을 위한 유망한 원천이 될 수 있다. 실제로 여러 연구에서 뇌졸중에 대한 한의학의 효능이 밝혀져 허혈성 뇌졸중에 대한 한의학적 치료 가치가 부각되고 있다. 본 리뷰에서는 허혈성 뇌졸중으로 인한 BBB 붕괴에 대한 전통적인 한의학의 처방, 탕약, 약재 및 활성 성분의 개선효과에 관한 현재 정보와 기본 메커니즘을 요약 정리하였다. 이러한 연구가 한의학의 신경보호 효과에 대한 추가 조사를 촉진하고 뇌졸중 환자에 대한 한방유래의 임상시험 시행을 활성화하는데 도움이 되기를 기대한다.

Effects of functional nutrients on chicken intestinal epithelial cells induced with oxidative stress

  • Hyun Woo Kim;Seung Yun Lee;Sun Jin Hur;Dong Yong Kil;Jong Hyuk Kim
    • Journal of Animal Science and Technology
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    • 제65권5호
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    • pp.1040-1052
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    • 2023
  • The objective of this study was to investigate the protective effects of functional nutrients including various functional amino acids, vitamins, and minerals on chicken intestinal epithelial cells (cIECs) treated with oxidative stress. The cIECs were isolated from specific pathogen free eggs. Cells were exposed to 0 mM supplement (control), 20 mM threonine (Thr), 0.4 mM tryptophan (Trp), 1 mM glycine (Gly), 10 μM vitamin C (VC), 40 μM vitamin E (VE), 5 μM vitamin A (VA), 34 μM chromium (Cr), 0.42 μM selenium (Se), and 50 μM zinc (Zn) for 24 h with 6 replicates for each treatment. After 24 h, cells were further incubated with fresh culture medium (positive control, PC) or 1 mM H2O2 with different supplements (negative control, NC and each treatment). Oxidative stress was measured by cell proliferation, whereas tight junction barrier function was analyzed by fluorescein isothiocyanate (FITC)-dextran permeability and transepithelial electrical resistance (TEER). Results indicated that cell viability and TEER values were less (p < 0.05) in NC treatments with oxidative stress than in PC treatments. In addition, FITC-dextran values were greater (p < 0.05) in NC treatments with oxidative stress than in PC treatments. The supplementations of Thr, Trp, Gly, VC, and VE in cells treated with H2O2 showed greater (p < 0.05) cell viability than the supplementation of VA, Cr, Se, and Zn. The supplementations of Trp, Gly, VC, and Se in cells treated with H2O2 showed the least (p < 0.05) cellular permeability. In addition, the supplementation of Thr, VE, VA, Cr, and Zn in cells treated with H2O2 decreased (p < 0.05) cellular permeability. At 48 h, the supplementations of Thr, Trp, and Gly in cells treated with H2O2 showed the greatest (p < 0.05) TEER values among all treatments, and the supplementations of VC and VE in cells treated with H2O2 showed greater (p < 0.05) TEER values than the supplementations of VA, Cr, Se, and Zn in cells treated with H2O2. In conclusion, Thr, Trp, Gly, and VC supplements were effective in improving cell viability and intestinal barrier function of cIECs exposed to oxidative stress.

Effects of 3,3′,4,4′,5-pentachloro biphenyl (PCB126) on the Expression the Tight Junction Genes in Cultured Mouse Neonatal Testis

  • Gye, Myeong-Chan;Fukuzawa, Noriho Honda;Ohsako, Seiichiro
    • 한국발생생물학회:학술대회논문집
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    • 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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    • pp.63-63
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    • 2003
  • In an effort to uncover the spermatogenic impairment by the polychlorinated biphenyls (PCBs), the expression of tight junctions (TJs) genes important for the formation of the blood testis barrier (BTB) were examined following the 3,3',4,4',5-pentachloro biphenyl (PCB126) treatment in cultured neonatal testis in mice. At 4 days (D4) after 10 and 100 nM PCB126 treatment the expression of claudin-11 was significantly increased when compared with vehicle control. In contrast no difference in occludin and claudin-1 expression was found among the experimental group. On D8, 100 nM PCB126 significantly increased the expression of claudin-11 but not occludin and claudin-1. 1 uM PCB126 treatment significantly decreased expressions of occludin and ciaudin -1, suggesting the general toxic effect on the Sertoli cell. Because PCB126 does not alter the proliferative activity of spermatogenic cells and Sertoli cells in neonatal testis, it is likely that increase in the expression of claudin-11 by low dose of PCB126 may attribute to the alteration of the Sertoli cells differentiation in testis. It also emphasized that PCB126 might have differentially affected the transcription of TJ genes in Sertoli cells. In conclusion, this result suggests that the structure of TJ may be targeted by PCB126 in neonatal testis in mice and that co-PCB is potentially harmful to spermatogenesis by alteration of the development of BTB.

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장내 상피세포 점막 투과성에 대한 유산균 및 금은화의 효과 (In Vitro Profiling of Bacterial Influence and Herbal Applications of Lonicerae Flos on the Permeability of Intestinal Epithelial Cells)

  • 이신지;이명종;정지은;김호준
    • 한국식품영양과학회지
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    • 제41권7호
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    • pp.881-887
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    • 2012
  • 유산균과 금은화, 발효 금은화는 장누수 증후군과 연관된 장 상피세포 점막 투과성 감소에 대하여 유의한 효과를 나타내었다. 따라서 유산균을 단독으로 사용하는 방법과 유산균을 이용해 발효시킨 금은화를 증가된 장 투과성 및 장내미생물 불균형으로 인한 장누수 증후군과 관련된 일련의 증상들을 치료하고 면역관련 질환 및 만성 염증성 질환에도 응용할 수 있을 것으로 예상되며 이에 대한 앞으로의 추가 연구가 필요할 것으로 사료된다.

Structural properties of vacancy defects, dislocations, and edges in graphene

  • Lee, Gun-Do;Yoon, Eui-Joon;Hwang, Nong-Moon;Kim, Young-Kuk;Ihm, Ji-Soon;Wang, Cai-Zhuang;Ho, Kai-Ming
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.428-429
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    • 2011
  • Recently, we performed ab initio total energy calculation and tight-binding molecular dynamics (TBMD) simulation to study structures and the reconstruction of native defects in graphene. In the previous study, we predicted by TBMD simulation that a double vacancy in graphene is reconstructed into a 555-777 composed of triple pentagons and triple heptagons [1]. The structural change from pentagon-octagon-pentagon (5-8-5) to 555-777 has been confirmed by recent experiments [2,3] and the detail of the reconstruction process is carefully studied by ab initio calculation. Pentagon-heptagon (5-7) pairs are also found to play an important role in the reconstruction of vacancy in graphene and single wall carbon nanotube [4]. In the TBMD simulation of graphene nanoribbon (GNR), we found the evaporation of carbon atoms from both the zigzag and armchair edges is preceded by the formation of heptagon rings, which serve as a gateway for carbon atoms to escape. In the simulation for a GNR armchair-zigzag-armchair junction, carbon atoms are evaporated row-by-row from the outermost row of the zigzag edge [5], which is in excellent agreement with recent experiments [2, 6]. We also present the recent results on the formation and development of dislocation in graphene. It is found that the coalescence of 5-7 pairs with vacancy defects develops dislocation in graphene and induces the separation of two 5-7 pairs. Our TBMD simulations also show that adatoms are ejected and evaporated from graphene surface due to large strain around 5-7 pairs. It is observed that an adatom wanders on the graphene surface and helps non-hexagonal rings change into stable hexagonal rings before its evaporation.

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Contributions of HO-1-Dependent MAPK to Regulating Intestinal Barrier Disruption

  • Zhang, Zhenling;Zhang, Qiuping;Li, Fang;Xin, Yi;Duan, Zhijun
    • Biomolecules & Therapeutics
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    • 제29권2호
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    • pp.175-183
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    • 2021
  • The mitogen-activated protein kinase (MAPK) pathway controls intestinal epithelial barrier permeability by regulating tight junctions (TJs) and epithelial cells damage. Heme oxygenase-1 (HO-1) and carbon monoxide (CO) protect the intestinal epithelial barrier function, but the molecular mechanism is not yet clarified. MAPK activation and barrier permeability were studied using monolayers of Caco-2 cells treated with tissue necrosis factor α (TNF-α) transfected with FUGW-HO-1 or pLKO.1-sh-HO-1 plasmid. Intestinal mucosal barrier permeability and MAPK activation were also investigated using carbon tetrachloride (CCl4) administration with CoPP (a HO-1 inducer), ZnPP (a HO-1 inhibitor), CO releasing molecule 2 (CORM-2), or inactived-CORM-2-treated wild-type mice and mice with HO-1 deficiency in intestinal epithelial cells. TNF-α increased epithelial TJ disruption and cleaved caspase-3 expression, induced ERK, p38, and JNK phosphorylation. In addition, HO-1 blocked TNF-α-induced increase in epithelial TJs disruption, cleaved caspase-3 expression, as well as ERK, p38, and JNK phosphorylation in an HO-1-dependent manner. CoPP and CORM-2 directly ameliorated intestinal mucosal injury, attenuated TJ disruption and cleaved caspase-3 expression, and inhibited epithelial ERK, p38, and JNK phosphorylation after chronic CCl4 injection. Conversely, ZnPP completely reversed these effects. Furthermore, mice with intestinal epithelial HO-1 deficient exhibited a robust increase in mucosal TJs disruption, cleaved caspase-3 expression, and MAPKs activation as compared to the control group mice. These data demonstrated that HO-1-dependent MAPK signaling inhibition preserves the intestinal mucosal barrier integrity by abrogating TJ dysregulation and epithelial cell damage. The differential targeting of gut HO-1-MAPK axis leads to improved intestinal disease therapy.