• 생명과학회지
• /
• 제27권5호
• /
• pp.600-610
• /
• 2017

가려움증의 분류는 수용체성 가려움증(Pruritoceptive itch), 신경병증 가려움증(Neuropathic itch), 신경성 가려움증(Neurogenic itch), 심인성 가려움증(Psychogenic itch)의 신경생리학적 기전에 따른 4가지 카테고리로 분류하는 것이 일반적이었으나 최근 임상적인 기준을 통해 분류하기도 한다. 가려움증의 신경전달 경로는 히스타민-의존 경로와 히스타민-비의존 경로 2가지로 나뉘며 각 가려움증 매개체마다 서로 다른 수용체와 신경펩티드가 작용한다. 히스타민, BAM8-22, chloroquine 등의 가려움증 매개체는 히스타민-의존 경로를 통해 신호가 전달되며 cowhage spicule, 단백분해효소(protease), TSLP (Thymic stromal lymphopoietin) 등의 매개체가 히스타민-비의존 경로와 관련있다는 보고가 있다. 이러한 가려움증 매개체, 수용체, 신경펩티드는 가려움증 치료의 대상이 된다. 가려움증과 통증은 대표적인 유해자극으로서 과거에는 두 감각이 하나의 유해자극수용체를 통해 전달된다는 주장이 있었지만 최근 밝혀진 바에 따르면 가려움증과 통증은 독립적인 신경전달체계를 가지고 있으며 두 신경체계는 서로 억제작용을 한다. 가려움증 뉴런의 선택적 소집단이 존재한다는 주장을 뒷받침하는 연구들이 이 주장에 무게를 싣고 있다. 또한 가려움증과 통증의 상호 길항작용에 대해서도 다양한 기전으로 설명되고 있다. 최근에도 새롭게 연구되는 매개체와 수용체들이 많은 연구들을 통해 밝혀지고 있다. 특히 최근에는 히스타민 4 수용체에 대한 연구가 활발히 진행되고 있는데, 이는 T 세포 같은 면역세포 자체에 발현되어 있어 이 H4 수용체를 차단하는 치료제는 말초의 매개체를 차단하는 기존의 히스타민 수용체 차단제와는 달리 가려움증 만성화에 중요한 염증 반응 자체를 억제할 수 있다는 점에서 그 유용성이 크다고 할 수 있다. 가려움증의 기본적인 발생 기전에 대한 이해와 새로운 가려움증 매개체에 대한 연구는 효과적인 치료법의 개발로 이어질 것이며 이것이 가려움증 연구가 나아갈 바로 생각한다.

• Journal of Ginseng Research
• /
• 제42권2호
• /
• pp.199-207
• /
• 2018

Background: Ginseng is a well-known traditional Chinese medicine that has been widely used in a range of therapeutic and healthcare applications in East Asian countries. Microbial transformation is regarded as an effective and useful technology in modification of nature products for finding new chemical derivatives with potent bioactivities. In this study, three minor derivatives of ginsenoside compound K were isolated and the inducing effects in the Wingless-type MMTV integration site (Wnt) signaling pathway were also investigated. Methods: New compounds were purified from scale-up fermentation of ginsenoside Rb1 by Paecilomyces bainier sp. 229 through repeated silica gel column chromatography and high pressure liquid chromatography. Their structures were determined based on spectral data and X-ray diffraction. The inductive activities of these compounds on the Wnt signaling pathway were conducted on MC3T3-E1 cells by quantitative real-time polymerase chain reaction analysis. Results: The structures of a known 3-keto derivative and two new dehydrogenated metabolites were elucidated. The crystal structure of the 3-keto derivative was reported for the first time and its conformation was compared with that of ginsenoside compound K. The inductive effects of these compounds on osteogenic differentiation by activating the Wnt/b-catenin signaling pathway were explained for the first time. Conclusion: This study may provide a new insight into the metabolic pathway of ginsenoside by microbial transformation. In addition, the results might provide a reasonable explanation for the activity of ginseng in treating osteoporosis and supply good monomer ginsenoside resources for nutraceutical or pharmaceutical development.

• Animal Bioscience
• /
• 제34권1호
• /
• pp.143-153
• /
• 2021

Objective: To explore the molecular mechanisms of fatty liver hemorrhagic syndrome (FLHS) in laying hens, an experiment was conducted to reveal the differences in histopathological observation and gene expression between FLHS group and normal group. Methods: We compared the histopathological difference using hematoxylin and eosin staining and proceeded with RNA sequencing of adipose tissue to search differentially expressed genes and enriched biological processes and pathways. Then we validated the mRNA expression levels by real-time polymerase chain reaction and quantified protein levels in the circulation by enzyme-linked immunosorbent assay. Results: We identified 100 differentially expressed transcripts corresponding to 66 genes (DEGs) were identified between FLHS-affected group and normal group. Seven DEGs were significantly enriched in the immune response process and lipid metabolic process, including phospholipase A2 group V, WAP kunitz and netrin domain containing 2, delta 4-desaturase sphingolipid 2, perilipin 3, interleukin-6 (IL-6), ciliary neurotrophic factor (CNTF), and suppressor of cytokine signaling 3 (SOCS3). And these genes could be the targets of immune response and be involved in metabolic homeostasis during the process of FLHS in laying hens. Based on functional categories of the DEGs, we further proposed a model to explain the etiology and pathogenesis of FLHS. IL-6 and SOCS3 mediate inflammatory responses and the satiety hormone of leptin, induce dysfunction of Jak-STAT signaling pathway, leading to insulin resistance and lipid metabolic disorders. Conversely, CNTF may reduce tissue destruction during inflammatory attacks and confer protection from inflammation-induced insulin resistance in FLHS chickens. Conclusion: These findings highlight the therapeutic implications of targeting the JAK-STAT pathway. Inhibition of IL6 and SOCS3 and facilitation of CNTF could serve as a favorable strategy to enhance insulin action and improve glucose homoeostasis, which are of importance for treating obesity-related disorders for chickens.

• Parasites, Hosts and Diseases
• /
• 제56권2호
• /
• pp.135-145
• /
• 2018

Due to the critical location and physiological activities of the retinal pigment epithelial (RPE) cell, it is constantly subjected to contact with various infectious agents and inflammatory mediators. However, little is known about the signaling events in RPE involved in Toxoplasma gondii infection and development. The aim of the study is to screen the host mRNA transcriptional change of 3 inflammation-related gene categories, PI3K/Akt pathway regulatory components, blood vessel development factors and ROS regulators, to prove that PI3K/Akt or mTOR signaling pathway play an essential role in regulating the selected inflammation-related genes. The selected genes include PH domain and leucine- rich-repeat protein phosphatases (PHLPP), casein kinase2 (CK2), vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), glutamate-cysteine ligase (GCL), glutathione S-transferase (GST), and NAD(P)H: quinone oxidoreductase (NQO1). Using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we found that T. gondii up-regulates PHLPP2, $CK2{\beta}$, VEGF, GCL, GST and NQO1 gene expression levels, but down-regulates PHLPP1 and PEDF mRNA transcription levels. PI3K inhibition and mTOR inhibition by specific inhibitors showed that most of these host gene expression patterns were due to activation of PI3K/Akt or mTOR pathways with some exceptional cases. Taken together, our results reveal a new molecular mechanism of these gene expression change dependent on PI3K/Akt or mTOR pathways and highlight more systematical insight of how an intracellular T. gondii can manipulate host genes to avoid host defense.

• 공업화학
• /
• 제17권6호
• /
• pp.638-643
• /
• 2006

과잉수소 반응조건하에서 dichloromethane ($CH_{2}Cl_{2}$)의 열분해 생성물질의 반응경로를 규명하기 위해서 등온 관형반응기를 이용하여 무산소, 1 atm, 반응온도 $525{\sim}900^{\circ}C$, 반응시간 0.3~2.0 sec에서 반응을 수행하였다. $CH_{2}Cl_{2}$ : $H_{2}$ mole 비는 전 실험에서 4 : 96으로 유지하였으며 반응물 $CH_{2}Cl_{2}$ 분해 및 생성물의 농도는 on-line GC를 이용하여 정량 분석하였으며, 미량의 미지 화합물은 batch 시료로써 GC/MS로 정성 분석하였다. 반응시간 1 sec를 기준으로 반응물 $CH_{2}Cl_{2}$는 $600^{\circ}C$ 부근에서 분해가 시작되어 $780^{\circ}C$에서 99% 이상 분해되었다. 반응 주요생성물은 $CH_{3}Cl$, $CH_{4}$, $C_{2}H_{4}$, $C_{2}H_{6}$, HCl이 생성되었으며, 미량 생성물로는 $CHClCCl_{2}$, CHClCHCl, $CH_{2}CHCl$, $C_{2}H_{2}$가 생성되었다. 본 연구에서는 반응물질 분해 및 중간생성물 분포 특성과 열역학 및 반응속도 원리를 근거로 주요 생성물질 반응경로를 제시하였으며, 그 결과는 $CH_{2}Cl_{2}$ 및 유사한 염화탄화수소 화합물 열분해시 일어날 수 있는 열분해공정 이해를 위한 자료로 이용된다.

• 청정기술
• /
• 제26권4호
• /
• pp.311-320
• /
• 2020

본 연구에서는 단순 침전법으로 제조한 CdS 및 CdZnS/ZnO 광촉매를 이용하여 가시광선하에서 로다민 B, 메틸 오렌지 및 메틸렌 블루 등에 대한 광분해 반응 연구를 수행하였다. 특히 염료와 광촉매의 물리화학적 성질이 전체 광촉매 반응의 반응 경로에 미치는 영향에 대해 중점을 두고 검토하였다. X선 회절분석법, UV-vis 확산반사 분광법 그리고 X선 광전자 분광분석법 등을 이용하여 제조된 촉매들의 물리화학적 특성을 분석하였다. CdS 및 CdZnS/ZnO 광촉매 모두 자외선뿐만 아니라 가시광선 영역에 있어서도 우수한 광흡수 특성을 나타내었다. 메틸 오렌지의 경우에는 CdS 및 CdZnS/ZnO 각각의 광촉매 상에서 동일한 반응기구를 통해 반응이 진행되는 반면, 로다민 B 및 메틸렌 블루는 각각의 광촉매 상에서 서로 다른 반응 경로를 통해 광분해 반응이 진행되는 것으로 나타났다. 특히 메틸렌 블루의 광분해 반응을 보면, CdZnS/ZnO 광촉매 상에서는 주로 단일분자 형태로 전체 반응이 진행되지만, CdS 상에서는 반응 초기부터 이량체를 형성하였다. 이와 같은 결과들은 CdS 및 CdZnS/ZnO 각각의 반도체 광촉매들의 전도대의 띠끝 전위 차이와 염료들의 흡착 특성 차이에 기인한 것으로 판단된다.

• Journal of Photoscience
• /
• 제6권1호
• /
• pp.29-36
• /
• 1999

Chlorophasts are a central structural feature of stomatal guard cells. Guard cell chloroplasts have both photosystems I and II (PS I and II), carry out O2 evoluation , cyclic and noncyclic photophosporylation, and possess the Calvin-Benson cycle enzymes involved in CO2 fixation. These imply that guard cell chloroplasts have a normal photosynthetic carbon reduction pathway just like their mesophyll counterparts, indicating similar fuctional organization of thylakoid membranes in both types of mesophyll and guard cell chloroplasts. It has been, however, found that guard cell chloroplasts have distinctive and comparative properties in their photosynthetic performance. In this article, I review the intrinsic features on the light reaction of and carbon reduction by guard cell chloroplasts.

• Journal of Microbiology and Biotechnology
• /
• 제7권3호
• /
• pp.212-214
• /
• 1997

A new isolate, Bacillus sp. ALK-7 can synthesize ethylene from l-aminocyclopropane-l-carboxylic acid (ACC) as well as from methionine. The ACC has only been recognized as a key intermediate found in the metabolic pathway leading to ethylene formation in various plants. The efficiency of ethylene formation from the ACC by Bacillus sp. ALK-7 was about 2 times as high as that from the methionine. The reaction from ACC to ethylene formation was also shown to be mediated by the cell-free extracts of Bacillus sp. ALK-7.

• BMB Reports
• /
• 제33권1호
• /
• pp.1-36
• /
• 2000

Acetohydroxyacid synthase (EC 4.1.3.18) catalyses the first reaction in the pathway for synthesis of the branched-chain amino acids. The enzyme is inhibited by several commercial herbicides and has been subjected to detailed study over the last 20 to 30 years. Here we review the progress that has been made in understanding its structure, regulation, mechanism, and inhibition.

• 한국군사과학기술학회지
• /
• 제14권4호
• /
• pp.726-731
• /
• 2011

Polymers containing tetrazole groups are very attractive as energetic materials. Copolymer having tetrazole groups could be obtained by 3-steps from commercially available epichlorohydrin. These methods provide a new synthetic pathway to construct polymers containing tetrazole groups from non-energetic polynitrile compounds. These polymers are expected to be good candidates for green and high energetic materials.