• 제목/요약/키워드: Biological mechanism

검색결과 1,501건 처리시간 0.041초

Role of G Protein-Coupled Estrogen Receptor in Cancer Progression

  • Jung, Joohee
    • Toxicological Research
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    • 제35권3호
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    • pp.209-214
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    • 2019
  • Cancer is the leading cause of mortality worldwide. In cancer progression, sex hormones and their receptors are thought to be major factors. Many studies have reported the effects of estrogen and estrogen receptors (ERs) in cancer development and progression. Among them, G protein-coupled estrogen receptor (GPER), a G protein-coupled receptor, has been identified as an estrogen membrane receptor unrelated to nuclear ER. The mechanism of GPER, including its biological action, function, and role, has been studied in various cancer types. In this review, we discuss the relation between GPER and estrogen or estrogen agonists/antagonists and cancer progression.

Enhancing Effect and Action Mechanism of Interleukin-4 Production in Activated T Cells by Phytoestrogens

  • Park, Jin;Kim, Tae-Sung
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.131.1-131.1
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    • 2003
  • Phytoestrogens are naturally occurring compounds derived from plants. Structurally, some phytoestrogens resemble endogenous estrogen of humans and animals. Phytoestrogens exhibit estrogen agonist/antagonist properties and have many biological effects such as prevention of hormone-dependent breast cancer, anti-oxidative activity, inhibition of tyrosine kinase activities and inhibition of angiogenesis. In this study we investigated whether biochanin A, a phytoestrogen, and its metabolites such genistein, p-ethylphenol and phenolic aic affect IL-4 production in EL-4 thymoma cell-line and primary lymph node cells. (omitted)

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Effects of chitosan on the decreased renal dipeptidase release by nitric oxide from renal proximal tubules

  • Yoon, Hyun-Joong;Park, Eun-Mi;Park, Haeng-Soon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.319.2-319.2
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    • 2002
  • Chitin is a major component of the shells of crustacea such as crab. shrimp and crawfish. Renal dipeptidase (RDPase. EC 3.4.13.19), an ectoenzyme of renal proximal tubules. is covalently bound to outer leaflet of lipid bilayer via glycosylphosphatidylinositol (GPI)-anchor. The biological role of RDPase was suggested as the hydrolysis of dipeptide into free-amino acids before renal reabsorption. The underlying biochemical mechanism of decreased RDPase release was suggested as nitric oxide (NO) production. (omitted)

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식물 자원을 활용한 염증반응 조절 (Modulation of Inflammation by Plant Resources)

  • 이하늘;성수희;김보람;김진호;서찬;임수아;김정은;정지민;정진우
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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    • pp.17-17
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    • 2023
  • Chrysanthemum zawadskii (C. zawadskii) is used in traditional East Asian medicine for the treatment of various diseases, including inflammatory disease. However, it has remained unclear whether extracts of C. zawadskii inhibit inflammasome activation in macrophages. The present study assessed the inhibitory effect of an ethanol extract of C. zawadskii (CZE) on the activation of the inflammasome in macrophages and the underlying mechanism. Bone marrow[-derived macrophages (BMDMs) were obtained from wild-type C57BL/6 mice. The release of IL-1β and lactate dehydrogenase in response to nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activators, such as ATP, nigericin and monosodium urate (MSU) crystals, was significantly decreased by CZE in lipopolysaccharide(LPS)-primed BMDMs. Western blotting revealed that CZE inhibited ATP-induced caspase-1 cleavage and IL-1β maturation. To investigate whether CZE inhibits the priming step of the NLRP3 inflammasome, we confirmed the role of CZE at the gene level using RT-qPCR. CZE also downregulated the gene expression of NLRP3 and pro-IL-1β as well as NF-κB activation in BMDMs in response to LPS. Apoptosis associated speck-like protein containing a caspase-recruitment domain (CARD) oligomerization and speck formation by NLRP3 inflammasome activators were suppressed by CZE. By contrast, CZE did not affect NLR family CARD domain containing protein 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome activation in response to Salmonella typhimurium and poly(dA:dT) in LPS-primed BMDMs, respectively. The results revealed that three key components of CZE, namely linarin, 3,5-dicaffeoylquinic acid and chlorogenic acid, decreased IL-1β secretion in response to ATP, nigericin and MSU. These findings suggest that CZE effectively inhibited activation of the NLRP3 inflammasome.

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The Existence of a Putative Regulatory Element in 3'-Untranslated Region of Proto-oncogene HOX11's mRNA

  • Li, Yue;Jiang, Zhao-Zhao;Chen, Hai-Xu;Leung, Wai-Keung;Sung, Joseph J.Y.;Ma, Wei-Jun
    • BMB Reports
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    • 제38권4호
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    • pp.500-506
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    • 2005
  • HOX11 encodes a homeodomain-containing transcription factor which directs the development of the spleen during embryogenesis. While HOX11 expression is normally silenced through an unknown mechanism in all tissues by adulthood, the deregulation of HOX11 expression is associated with leukemia, such as T-cell acute lymphoblastic leukemia. The elucidation of regulatory elements contributing to the molecular mechanism underlying the regulation of HOX11 gene expression is of great importance. Previous reports of HOX11 regulatory elements mainly focused on the 5'-flanking region of HOX11 on the chromosome related to transcriptional control. To expand the search of putative cis-elements involved in HOX11 regulation at the post-transcriptional level, we analyzed HOX11 mRNA 3'-untranslated region (3'UTR) and found an AU-rich region. To characterize this AU-rich region, in vitro analysis of HOX11 mRNA 3'UTR was performed with human RNA-binding protein HuR, which interacts with AU-rich element (ARE) existing in the 3'UTR of many growth factors' and cytokines' mRNAs. Our results showed that the HOX11 mRNA 3'UTR can specifically bind with human HuR protein in vitro. This specific binding could be competed effectively by typical ARE containing RNA. After the deletion of the AU-rich region present in the HOX11 mRNA 3'UTR, the interaction of HOX11 mRNA 3'UTR with HuR protein was abolished. These findings suggest that HOX11 mRNA 3'UTR contains cis-acting element which shares similarity in the action pattern with RE-HuR interactions and may involve in the post-transcriptional regulation of the HOX11 gene.

신체화의 생물학적 기전 : 신체화의 신경심리학적 모델을 중심으로 (Biological Mechanism of Somatization : Mainly Focused on the Neuropsychological Model of Somatization)

  • 이영호
    • 정신신체의학
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    • 제8권1호
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    • pp.122-140
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    • 2000
  • 신체화 장애란 명백한 기질적 병리가 없이 다양한 신체 증상을 호소하는 만성 장애를 말한다. 그런데 신체화 장애는 역사적으로 기질적인 이상이 없이 신체적인 증상이 나타나는 히스테리와 연관이 있다고 알려져 왔다. 따라서 신체화와 관련된 대부분의 이론들은 주로 정신역동이나 사회적인 관점에 초점이 맞추어져 왔다. 그러나 감정적인 문제나 정신질환이 신체화로 나타나는 기전에서 신경생물학적인 관점에 대한 관심 또한 적지 않았었다. 이런 신경생물학적인 관점에서 히스테리아의 원형으로 알려져 있는 Anna O 증례조차도 신경심리학적인 관점에서 재조명되기도 하였다. 몇몇 신경생리학적 및 신경심리학적 연구결과들, 히스테리 환자에서 신체화증상 표현의 좌우 반구차이에 대한 연구결과들이 신체화의 생물학적 근거를 뒷받침해 주고 있다. 최근 들어 신체화 장애의 신경영상검사는 신체화 장애에서 뇌의 기능 이상이 존재함을 보여 주고 있다. 이에 저자는 생물학적 관점에서 신체화의 과정을 설명해 줄 수 있는 몇몇 가설들을 고찰하고 이를 바탕으로 신체화에 대한 새로운 신경심리학적 가설을 제시하고자 한다. 이와 함께 이 가설을 신체화 장애의 치료에 어떻게 적용시킬 수 있을까도 논의하고 이 가설의 제한정과 이 영역에 있어 앞으로의 발전 방향에 대해서도 논의하려고 한다.

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Streptococcus mutans의 전사체 분석과 독활 추출물로부터 활성 성분 분리 (Transcriptome Analysis of Streptococcus mutans and Separation of Active Ingredients from the Extract of Aralia continentalis)

  • 이현정;강다영;이윤채;김정남
    • 생명과학회지
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    • 제33권7호
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    • pp.538-548
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    • 2023
  • 식물 천연추출물에서 항균력을 갖는 활성 물질을 분리하고 이를 구강 건강 관리 제품에 사용하려는 연구가 진행되고 있다. 본 연구에서는 유기용매를 사용하여 독활과 우방자로부터 추출한 복합 화합물에 대한 구강 감염균인 Streptococcus mutans의 특정 유전자 발현 변화를 분석하여 항균 기작을 분석하고자 하였다. 전사체 분석 결과, 두 가지 천연추출물에 의해 다양한 대사 및 생리 작용과 연관된 유전자의 발현이 공통적으로 증가하거나 감소하는 것으로 나타났다. 세 가지 유전자(SMU_1584c, SMU_2133c, SMU_921)는 공통적으로 높은 수준으로 발현되었으며, 특히 이 중 SMU_921 (rcrR)은 두 가지 sugar phosphotransferase system (PTS)의 전사 활성자로써 당원의 수송과 생물막 형성에 기여하는 것으로 알려져 있다. 또한, 우방자 추출물에 비해 다수의 유전자 발현 변화에 영향을 미치는 것으로 나타난 독활 추출물의 성분 분석을 진행하였고, 활성 분획의 가스 크로마토그래피-질량분석법(GC-MS)을 통해 두 가지 활성 단일 물질을 동정하였다. 물질 분리 과정에서 여러 유기용매 분획 중 hexane층(ACEH)의 항균 활성이 가장 높게 관찰되었다. 다양종 미생물 군집을 사용한 실험결과, S. mutans에 대한 ACEH의 항균 특이성이 관찰되었으나, 상대적으로 S. sanguinis와 S. gordonii의 생균수도 크게 감소하는 것으로 나타났다. 이러한 결과는 독활 천연추출물의 광범위한 항균 활성을 시사하며, 동정한 단일 물질의 항균 기작을 분석하여 맞춤형 항균 소재 개발에 중요한 기초 자료를 제공할 수 있다.

노화의 기전과 예방 (Mechanism of aging and prevention)

  • 김재식
    • IMMUNE NETWORK
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    • 제1권2호
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    • pp.104-108
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    • 2001
  • Aging is a senescence and defined as a normal physiologic and structural alterations in almost all organ systems with age. As Leonard Hayflick, one of the first gerontologists to propose a theory of biologic aging, indicated that a theory of aging or longevity satisfies the changes of above conditions to be universal, progressive, intrinsic and deleterious. Although a number of theories have been proposed, it is now clear that cell aging (cell senescence) is multifactorial. No single mechanism can account for the many varied manifestations of biological aging. Many theories have been proposed in attempt to understand and explain the process of aging. Aging is effected in individual by genetic factors, diet, social conditions, and the occurrence of age-related diseases as diabetes, hypertension, and arthritis. It involves an endogenous molecular program of cellular senescence as well as continuous exposure throughout life to adverse exogenous influences, leading to progressive infringement on the cell's survivability so called wear and tear. So we could say the basic mechanism of aging depends on the irreversible and universal processes at cellular and molecular level. The immediate cause of these changes is probably an interference in the function of cell's macromolecules-DNA, RNA, and cell proteins-and in the flow of information between these macromolecules. The crucial questions, unanswered at present, concerns what causes these changes in truth. Common theories of aging are able to classify as followings for the easy comprehension. 1. Biological, 1) molecular theories - a. error theory, b. programmed aging theory, c. somatic mutation theory, d. transcription theory, e. run-out-of program theory, 2) cellular theories - a. wear and tear theory, b. cross-link theory, c. clinker theory, d. free radical theory, e. waste product theory, 3) system level theory-a. immunologic/autoimmune theory, 4) others - a. telomere theory, b. rate of living theory, c. stress theory, etc. Prevention of aging is theoretically depending on the cause or theory of aging. However no single theory is available and no definite method of delaying the aging process is possible by this moment. The most popular action is anti-oxidant therapy using vitamin E and C, melatonin and DHEA, etc. Another proposal for the reverse of life-span is TCP-17 and IL-16 administration from the mouse bone marrow B cell line study for the immunoglobulin VDJ rearrangement with RAG-1 and RAG-2. Recently conclusional suggestion for the extending of maximum life-span thought to be the calory restriction.

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살충성 Imidacloprid의 가수분해 반응 메카니즘 (Kinetics and Mechanism of Hydrolysis of Insecticidal Imidacloprid)

  • 유성재;강문성;성낙도
    • Applied Biological Chemistry
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    • 제40권1호
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    • pp.53-57
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    • 1997
  • 중성과 알카리성의 $45^{\circ}C$, 15%(v/v) dioxane 수용액중에서 살충성 imidacloprid (lUPAC:1-(6-chloro-3-pyridylmethyl)-3-N-nitro-iminoimidazolidine-2-ylideneamine)의 가수분해 반응속도 상수를 측정하고 pH-효과, 용매효과(m=0.04, n=0.30 및 m${\ll}$l), 열역학적 활성화 파라미터(${\Delta}S^{\neq}$=-0.03e.u. 및 ${\Delta}S^{\neq}=16.14\;kcal{\cdot}mol^-$), 반응 생성물 분석등의 결과로부터 반응 속도식($K_{obs}=4.56{\times}10^{-3}[OH^-]$)을 유도하여 특정 염기촉매 반응($K_{OH^-}$)으로 사면체($sp^3$) 중간체인 1-(6-chloro-3-pyridylmethyl)-2-hydroxy-2-imidazolidinylisonitraminate(I)을 거쳐 imidazolidine 고리 열림반응으로 $\beta$-3-(6-chloro-3-pyridylmethyl)aminoethyl-1-nitrourea(III)를 경유한 다음에 1-(6-chloro-3-pyridylmethyl)aminoethyl-1-nitrourea(III)으로 분해되는 일련의 친핵성 첨가-제거($Ad_N-E$) 반응메카니즘을 제안하였다. 그리고 $45^{\circ}C$의 중성(pH 8.0)에서 반감기(t1/2)는 약 4.5개월로 잔류성이 큰 화합물임을 알았다.

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골아세포내 $Ca^{2+}$ 활성도의 조절기전 (Mechanism of $Ca^{2+}$ Regulation in Osteoblast-like Cells)

  • 박미정
    • Journal of Korean Biological Nursing Science
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    • 제1권1호
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    • pp.25-41
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    • 1999
  • Physiological activity of osteoblast including bone formation is known to be closely related to the increase of intracellular $Ca^{2+}$ activity($[Ca^{2+}]_i$) in osteoblast. $Ca^{2+}$ is an important intracellular messenger in diverse cellular functions, and regulation of its level is mediated by the transmembrane $Ca^{2+}$ movement via $Ca^{2+}$ channels, $Na^+-Ca^{2+}$ exchange, and by intracellular $Ca^{2+}$ movement through the intracellular stores. The purpose of this study is to investigate how the intracellular $Ca^{2+}$ is regulated in osteoblast-like cells(OLCs) by measuring $Ca^{2+}$ activity with cell imaging technique. OLCs were isolated from femur and tibia of neonatal rats, and cultured for 7 days. Cultured OLCs were loaded with a $Ca^{2+}$-sensitive fluorescent dye, Fura-2, and fluorescence images were monitored with a cooled CCD camera. The images were processed and analyzed with an image analyzing software. The results were as follows. (1) $[Ca^{2+}]_i$ of OLC decreased as the $Ca^{2+}$ concentration in the superfusing Tyrode solution was lowered. When $Na^+$ concentration in the superfusing solution was decreased, $[Ca^{2+}]_i$ increased.. These suggest that $Ca^{2+}$ flux occurs via the $Na^+-Ca^{2+}$ exchange mechanism. (2) When $Na^+$ in the superfusing solution was removed. a transient $Ca^{2+}$, increase($Ca^{2+}$ spike) was occasionally observed. However, $Ca^{2+}$ spike was not observed after adding 1 ${\mu}M$ thapsigargin. This implies that the generation of $Ca^{2+}$ spike is mediated by the release of $Ca^{2+}$ from endoplasmic reticulum(ER). (3) As the $Ca^{2+}$ concentration in the superfusing solution was raised, the frequency of 0mM $Na^+$-induced $Ca^{2+}$ spike increased, suggesting that $Ca^{2+}$-induced $Ca^{2+}$ release(CICR) mechanism exists. (4) After $[Ca^{2+}]_i$ was decreased with the superfusion of $Ca^{2+}$-free solution containing thapsigargin, the recovery of $[Ca^{2+}]_i$ with reperfusion of 2.5mM $Ca^{2+}$ solution transiently exceeded the control level, suggesting that the depletion of $Ca^{2+}$ in ER induces $Ca^{2+}$ influx from extracellular medium via store-operated $Ca^{2+}$ influx(SOCI) mechanism. (5) $[Ca^{2+}]_i$ was not affected by the superfusion of 25mM $K^+$ Tyrode solution. These results suggest that intracellular $Ca^{2+}$ activity in osteoblast is regulated by transmembrane $Ca^{2+}$ flux via $Na^+-Ca^{2+}$ exchange, $Ca^{2+}$ release from the internal store (ER) via $Ca^{2+}$-induced $Ca^{2+}$ release, and store-operated $Ca^{2+}$ influx across the cell membrane.

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