소포체 스트레스에 의한 대식세포의 세포사멸 : caspase 11의 잠재적 역할 a potential implication of caspase 11

정상원,김용찬,이혜영,백상기,김영상,강광일 충남대학교 생물공학연구소 2004 생물공학연구지 Vol.10 No.1

Apoptosis is caused by a set of previously latent proteases, the caspases, which cleave several hundred cellular substrates. It has been established that there are two basic signaling pathways to caspases activation. One is initiated by engagement of cell surface death receptors (extrinsic pathway). The other is provoked by perturbation of the mitochondrial membrane promoted by physical or chemical stress agents (intrinsic pathway). Recent studies point to the endoplasmic reticulum (ER) as a third subcellular compartment implicated in apoptotic cell death. The ER regulates protein synthesis, protein folding and trafficking, cellular responses to stress and intracellular calcium (Ca^(++)) levels. Alterations in Ca^(++) homeostasis and accumulation of misfolded proteins in the ER cause ER stress that ultimately leads to apoptotic cell death. Prolonged ER stress is linked to the pathogenesis of several different neurodegenerative disorders. However, ER stress-mediated cell death pathway in macrophage has not been studied well. Here, we demonstrate evidence for the thapsigargin-induced cell death and the potential contribution of caspase-11 which could be induced by ER stress in macrophage.

사람의 성산자극 호르몬 α-Subunit 유전자와 결합하는 Trans-Acting Factor의 확인 및 분석

송석민,백상기,김균언 충남대학교 생물공학연구소 1999 생물공학연구지 Vol.7 No.-

The 5' flanking region of the α-subunit gene of human chorionic gonadotropin was tested for the binding with the nuclear extracts of the JAR choriocarcinoma cells. Gel mobility shift assay has demonstrated that two BstNI restriction fragments, 150 bp and 340 bp respectively, have binding activities with the nuclear extracts. The 150 bp fragment was chosen to examine in detail, since several transcription factor binding sites have already been reported within the 340 bp fragment. Band competition assay showed that the binding of 150 bp fragment is highly sequence-specific. The binding activity was further narrowed down to a 55 bp fragment, which was generated by Nsi1 digestion of the 150 bp fragment. DNasel footprinting assay revealed the binding sites on the nucleotide levels from -511 to -499. The binding sites were again confirmed by a oligonucleotide-directed mutagenesis of the 150 bp fragment followed by a gel mobility shift assay. Functional aspect of this binding was evaluated with the DNA-mediated gene transfer techniques. However, in several appoaches tried so far, no effect on the transcription efficiency was observed, implicating a structural role of the binding. In this line, it is worth to note that the binding activity of the 150 bp fragment was observed in every cell or tissue nuclear extracts tested so far.

공공의 이익을 위한 특허발명의 강제실시 : 의약발명을 중심으로

유병선,백상기 충남대학교 생물공학연구소 2005 생물공학연구지 Vol.11 No.1

This study focuses on the establishment of compulsory license to the patented invention, particularly pharmaceutic patent for public interests. With a view to promoting the development of technology and industry, Patents Act grants patentees an exclusive right to exploit the patented invention. For the purpose of the same goal, on the other hand, Patents Act imposes a few limits upon the exclusive right of patentees. A compulsory license is one of the limits upon patent right. A compulsory license is not an exceptional management from outside, it already exists in the inside of the right in view of the fact that Patent is the right granted artificially to contribute to the development of the industry. Pharmaceutic patent is closely related to human life directly or indirectly. Accordingly it has been discussed internationally to establish compulsory license to pharmaceutic patent for public interests. Regarding this problem, advanced countries and undeveloped countries are at issue with each other. We examine our position about compulsory license to pharmaceutic patent considering the degree of industrial development, especially the reality of pharmaceutic industry where Multinational Corporation of foreign country produces the most medicine. In case of Korea, there is a necessity for compulsory license in wide ranges in comparison with advanced countries such as Canada, Britain, Germany, France and so on within the limits of Agreement on TRIPs. In view of the above statements, it raises several problems of compulsory license under the Patent Act of Korea and proposes their solution. First of all there needs the realistic interpretation of the requirements for public interests and the flexible viewpoint about compulsory license to pharmaceutic patent. It is finally submitted that statutory provisions on compulsory license are designed as an efficient means of promoting goals of the Patents Acts and, also, that terms, conditions and procedures for compulsory license will have to be amended to make a better balance between the interests of patentees and public interest.

B 림프구의 면역반응 조절과 자가면역

이혜영,백상기 충남대학교 생물공학연구소 2003 생물공학연구지 Vol.9 No.1

The immune system of any organism must preserve a well balance between activation and inhibition. It must raise an effective immune response to target non-self molecules while not hampering the organism itself. Failure to maintain this balance will result in either immunodeficiency or autoimmunity. In many systemic autoimmune diseases, the production of pathogenic autoantibodies, released from B lymphocytes, has been the causes of autoimmunity, although the nature of the mechanism remains unclear. In recent years, several factors involved in the survival and inhibition of B lymphocytes were uncovered and found to be related to the several autoimmune diseases. Those are B lymphocytes inhibitory receptors and cytokines such as FcrRⅡ, CD22, PD-1, BAFF and BAFF-R. Investigating the genetic alterations and signalling components in these molecules and the consequences for the regulation of apoptosis/survival could show distinct ways to cure autoimmune diseases.

일산화질소에 의한 유전자 발현 조절 : T세포 활성화 과정에서의 일산화질소의 역할 Roles of NO in T cell activation

김용찬,백상기,김영상 충남대학교 생물공학연구소 2003 생물공학연구지 Vol.9 No.2

Current interest in nitric oxide(NO) is derived from its numerous biological roles. NO modulates transcription factors that bind specific gene-regulatory regions responsible for changing microenvironment. In this way, NO regulates gene transcription and functional cellular responses to adapt changed metabolic environment against a variety of stress and disease conditions. NO is a potential key mediator of T-cell developments and responses. This review introduce recent understanding of mechanism by which NO regulates the gene expression and modulates the cellular responses in various conditions. From this review, basic insights into how cell activities are coordinated by NO will be provided.

플라이애시를 다량 사용한 콘크리트의 수화발열 특성과 압축강도 특성에 관한 실험적 연구

조규현,박무영,백민수,김우재,임남기,정상진 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

This study is for the great quantity use of fly-ash. For the producing of high volume concrete from the use of fly-ash, the method of replacement between bonding agents and fine aggregate by fly-ash at the slt was used that the adiabatic temperature rise of concrete about the mass member which bad been produced by the method that was mentioned before, and the hydration heat of the core test pieces in concrete was measured. Also the core test pieces which were replaced with fly-ash was studied by the compressive strength's comparison between standard care test pieces and core test pieces. In the case of mass test pieces, hydration heat and the time to reach the highest temperature were decreased by an increase in replaced fly-ash's amounts of concrete. In addition, among the test pieces having the same amounts of concrete, the test pieces having more replaced amounts of fly-ash's fine aggregate showed higher hydration heat and the increased time to reach the highest temperature. Compressive strength was also increased by hydration heat's decrease according to fly-ash replacement. Replacement of fly-ash was more effective in high temperature environment.

Nitric oxide(NO)의 조절과 기능 : 대식세포주에서 NO에 의해 상향 조절되는 유전자의 분석 Identification of a gene that is up-regulated in RAW264.7 macrophage cells by nitric oxide

맹옥희,김용찬,김영상,백상기,이혜영 충남대학교 생물공학연구소 2002 생물공학연구지 Vol.8 No.2

Nitric oxide (NO) and NO synthases have become an important research topic in cellular and molecular biology. NO is produced by many mammalian cells and performs a broad spectrum of signaling functions in the immunological, neurological and vascular system. NO has multiple molecular targets. It can not only directly influence the activity of transcription factors but also modulate upstream signaling cascades as well as the processing of the primary gene products. It was hypothesized that NO production induced a specific set of henetic programs that might serve to alter cellular metabolism in macrophage. A technique called suppression subtractive hybridization (SSH) was adopted to identify genes differentially expressed in NO-stimulated cells.

사람 HPRT 유전자 발현벡터 제조와 생쥐 Sp2/0 myeloma 세포주에서의 발현

고창보,김용만,김영진,백상기 충남대학교 기초과학연구소 1997 忠南科學硏究誌 Vol.24 No.1

To construct expression vector for the human HPRT gene, pRSVneo plasmid conferring resistance to neomycin-kanamycin(Tn5) antibiotics and pHPT 31 containing human HPRT cDNA were used to subclone human HPRT cDNA. For construction of recombinant pRSVneo carrying human HPRT, pRSVneo-HPRT, the human HPRT cDNA fragment from pHPT31 plasmid was inserted into polyadenylation site (BamHI site) behind the neo gene fragment of pRSVneo plasmid. For the other expression vector, pRSV-HPRT, the neo gene and small portion of the untranslated 5′franking region were removed from the pRSVneo-HPRT. The HPRT gene of the two vectors were constructed in right orientation. Each recombinant vector was introduced into cultured HPRT-deficient mouse cell line, Sp2/0 by calcium mediated DNA transfection and the transfected cells were selected under HAT selection condition. The HPRT activity of the lysates from the selected cell was higher than that of the lysates from spleen cells of mouse. The HPRT activity of pRSVneo-HPRT vector was higher than that of pRSV-HPRT one. To find out whether the HPRT activity of the transfected cells selected under HAT medium was expressed by transfected vectors or by spontaneous mutations, it was cultured to reselect in G418 medium. It showed that the nature of the HPRT activity was resulted from the transfected vectors.

대식세포주 RAW264.7에서 Nitric oxide에 의해 과발현되는 CD53의 기능분석

김태림,이혜영,김인규,백상기 충남대학교 생물공학연구소 2004 생물공학연구지 Vol.10 No.2

The CD53 antigen is a member of the tetraspanin membrane protein family that is expressed in the lymphoid-myeloid lineage. It is highly expressed in Radio-resistant tumor cells. Recently, it was reported that CD53 associates with the GSH-metabolizing protein γ-glutamyl transpeptidase. Its biological roles however remains unknown. Macrophages activated by microbial lipopolysaccharides (LPS) produce a burst of nitric oxide and reactive oxygen species. Nitric oxide plays important roles in macrophage activation as a toxic agent towards infectious organisms, an inducer or suppressor of apoptosis or an immunoregulator, whether nitric oxide can induce or inhibit apoptosis is highly dependent on different cell types at different stages of the inflammatory process. Using cDNA microarrays, we identified CD53 as one of the principal genes up-regulated by exposure of macrophages to LPS. We found that mRNA and protein levels of CD53 were increased by nitric oxide as well as LPS treatment in macrophages. Cells stably transfected with sense CD53 cDNA had lower levels of peroxide, and were more resistant to γ-irradiation. The stably transfected RAW264.7 cells with antisense CD53 recombination had the opposite properties. Activation of CD53 by cross-linking with monoclonal anti-CD53 antibody (OX-79) showed the expression of the inducible nitric oxide synthase. We propose that the induction of CD53 is one of major self-protection mechanisms of macrophages against LPS induced-oxidative stress and irradiation.

무정자증과 핍정자증 남자 Y-염색체 SRY 유전자의 염기서열 분석

김영진,유선아,백상기 충남대학교 생물공학연구소 1999 생물공학연구지 Vol.7 No.-

In order to study the genetic causes of sterility in azoospermia and severe oligospermia, we investigated the sequences of the SRY (sex determining region of Y chromosome) gene that is known to determine the maleness of human. A 609 bp fragment of SRY open reading frame, containing the entire known SRY, was amplified from genomic DNA with primers XES2 and XES7. It was amplified from genomci DNA of one normal man, three azoospermic man and four severe oligospermic man. These amplified DNAs were subcloned for DNA sequencing. In this study, we found that normal, azoospermic and severe oligospermic men had the base of thymine at 155th codon region, while SRY sequence study by Sinclair et al. (1990) showed the base of cytosine. As a result, C → T transition mutation at 155th codon in SRY gene coding region had occurred but there was no change in the amino acid sequence [serine (AGC) → serine (AGT)]. It seems that the polymorphism in the coding region of SRY gene was found in Korean population for the first time.