研究者詳細 - 久保田　聡

論文 - 久保田　聡

分割表示 229 件中 161 - 180 件目／全件表示 >>

Downregulation of rheumatoid arthritis-related antigen RA-A47 (HSP47/colligin-2) in chondrocytic cell lines induces apoptosis and cell-surface expression of RA-A47 in association with CD9

T Hattori, K von der Mark, H Kawaki, Y Yutani, S Kubota, T Nakanishi, H Eberspaecher, B de Crombrugghe, M Takigawa

JOURNAL OF CELLULAR PHYSIOLOGY 202 ( 1 ) 191 - 204 2005年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-LISS

Previously, we showed that gene expression of the rheurnatoid arthritis-related antigen RA-A47, which is identical to human heat shock protein (HSP)47, was downregulated in chondrocytes by inflammatory cytokines such as TNFalpha. Associated with this phenomenon, RA-A47 appeared on the cell surface concomitant with upregulation of metabolic factors related to cartilage destruction. The upregulation of the metabolic factors could be achieved by clownregulation of RA-A47 expression with ra-a47-specific anti-senseoligonucleotide. Here, we show that the enhanced surface expression of RA-A47 on a chondrocytic cell line, HCS-2/ 8 was also a direct result of RA-A47 downregulation by ra-a47 anti-sense oligonucleoticle, independent of the cytokine effects. Moreover, cell-surface expression of CD9, a l integrin-associated transmembrane protein that is involved in cell adhesion and cell motility events, was enhanced in the ra-a47 anti-sense oligonucleoticle-treated cells. The CD9 was colocalized with RA-A47 on the cell surface, where it may have affected integrin signaling. Furthermore, Annexin-V binding to the cell surface and the level of a number of apoptosis-related genes including caspase-9 were increased after ra-a47 anti-sense oligonucleoticle treatment, suggesting that enhanced surface expression of RA-A47 and CD9 may be initiating apoptosis. Differential screening using a cDNA gene array showed induction of metal lothionein-III and chemokine receptor CXCR4 and of factors of the Notch signaling pathway by the anti-sense treatment, but not by TNFalpha.. Thus, here we show for the first time an alternative mechanism of inducing apoptosis by downregulating molecular chaperones, independent of the action of TNFalpha. The surface-exposed RA-A47 may induce autoantibodies and inflammatory reactions in autoimmune disease situations such as rheurnatoid arthritis. J. Cell. Physiol. 202: 191 -204, 2005. (C) 2004 Wiley-Liss, Inc.

DOI： 10.1002/jcp.20112

Roles of CCN2/CTGF in the control of growth and regeneration.

Takigawa, M, Nishida, T, Kubota, S

In CCN Proteins: A New Family of Cell Growth and Differentiation Regulators (Perbal B. & Takigawa M. eds.) 19 - 59 2005年

岡山大学歯学部１年次生におけるテュートリアル教育の問題点と今後の課題.

完山学, 久保田聡, 市川博之, 十川紀夫, 平田あずみ, 美藤純弘, 岡本信, 福永智広, 香川智正, 中山周子, 坂本友紀, 吉田登志子, 宮脇卓也, 西村英紀, 松村誠士, 窪木拓男

岡山歯学会雑誌 24 ( 2 ) 97 - 104 2005年

岡山大学歯学部１年次学生に対するテュートリアル教育の成果：平成15年度プログラムの多面的解析.

久保田聡, 完山学, 吉田登志子, 十川紀夫, 山本龍生, 平田あずみ, 美藤純弘, 十川千春, 市川博之, 鈴木康司, 衣田圭宏, 丸尾幸憲, 宮脇卓也, 香川智正, 西村英紀, 窪木拓男, 松村誠士

岡山歯学会雑誌 24 ( 2 ) 85 - 95 2005年

A DEAD box protein facilitates HIV-1 replication as a cellular co-factor of Rev

JH Fang, S Kubota, B Yang, NM Zhou, H Zhang, R Godbout, RJ Pomerantz

VIROLOGY 330 ( 2 ) 471 - 480 2004年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

HIV-1 Rev escorts unspliced viral mRNAs out of the nucleus of infected cells, which allows formation of infectious HIV-1 virions. We have identified a putative DEAD box (Asp-Glu-Ala-Asp) RNA helicase, DDX1, as a cellular co-factor of Rev, through yeast and mammalian two-hybrid systems using the N-terminal motif of Rev as "bait". DDX1 is not a functional homolog of HIV-1 Rev, but down-regulation of DDX1 resulted in an alternative splicing pattern of Rev-responsive element (RRE)-containing mRNA, and attenuation of Gag p24 antigen production from HLfb rev(-) cells rescued by exogenous Rev. Co-transfection of a DDX1 expression vector with HIV-1 significantly increased viral production. DDX1 binding to Rev, as well as to the RRE, strongly suggest that DDX1 affects Rev function through the Rev-RRE axis. Moreover, down-regulation of DDX1 altered the steady state subcellular distribution of Rev, from nuclear/nucleolar to cytoplasmic dominance. These findings indicate that DDX1 is a critical cellular co-factor for Rev function, which maintains the proper subcellular distribution of this lentiviral regulatory protein. Therefore, alterations in DDX1-Rev interactions could induce HIV-1 persistence and targeting DDX1 may lead to rationally designed and novel anti-HIV-1 strategies and therapeutics. (C) 2004 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.virol.2004.09.039

Abundant retention and release of connective tissue growth factor (CTGF/CCN2) by platelets

S Kubota, K Kawata, T Yanagita, H Doi, T Kitoh, M Takigawa

JOURNAL OF BIOCHEMISTRY 136 ( 3 ) 279 - 282 2004年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JAPANESE BIOCHEMICAL SOC

Wound healing and tissue regeneration are usually initiated by coagulation followed by fibrous tissue formation. In the present study, we discovered an abundance of connective tissue growth factor (CTGF/CCN2) in human platelets, which was released along with the coagulation process. The CTGF/CCN2 content in platelets was 10-fold higher than that in arterial tissue. Furthermore, the CTGF/CCN2 content in a single platelet was computed to be more than 20-fold higher than that of any other growth factor reported. Considering that CTGF/CCN2 promotes angiogenesis, cartilage regeneration, fibrosis and platelet adhesion, it may be now regarded as one of the major functional components of platelets.

DOI： 10.1093/jb/mvh126

Regeneration of defects in articular cartilage in rat knee joints by CCN2 (connective tissue growth factor)

T Nishida, S Kubota, S Kojima, T Kuboki, K Nakao, T Kushibiki, Y Tabata, M Takigawa

JOURNAL OF BONE AND MINERAL RESEARCH 19 ( 8 ) 1308 - 1319 2004年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC BONE & MINERAL RES

CTGF/CCN2, a hypertrophic chondrocyte-specific gene product, possessed the ability to repair damaged articular cartilage in two animal models, which were experimental osteoarthritis and full-thickness defects of articular cartilage. These findings suggest that CTGF/CCN2 may be useful in regeneration of articular cartilage.
Introduction: Connective tissue growth factor (CTGF)/CCN2 is a unique growth factor that stimulates the proliferation and differentiation, but not hypertrophy, of articular chondrocytes in vitro. The objective of this study was to investigate the therapeutic use of CTGF/CCN2.
Materials and Methods: The effects of recombinant CTGF/CCN2 (rCTGF/CCN2) on repair of damaged cartilage were evaluated by using both the monoiodoacetic acid (MIA)-induced experimental rat osteoarthritis (OA) model and full-thickness defects of rat articular cartilage in vivo.
Results: In the MIA-induced OA model, quantitative real-time RT-PCR assays showed a significant increase in the level of CTGF/CCN2 mRNA, and immunohistochemical analysis and in situ hybridization revealed that the clustered chondrocytes, in which Clustering indicates an attempt to repair the damaged cartilage, produced CTGF/CCN2. Therefore, CTGF/CCN2 was suspected to play critical roles in cartilage repair. In fact, a single injection of rCTGF/CCN2 incorporated in gelatin hydrogel (rCTGF/CCN2-hydrogel) into the joint cavity of MIA-induced OA model rats repaired their articular cartilage to the extent that it became histologically similar to normal articular cartilage. Next, to examine the effect of rCTGF/CCN2 on the repair of articular cartilage, we created defects (2 mm in diameter) on the surface of articular cartilage in situ and implanted rCTGF/CCN2-hydrogel or PBS-hydrogel therein with collagen sponge. In the group implanted with rCTGF/CCN2-hydrogel collagen, new cartilage filled the defect 4 weeks postoperatively. In contrast, only soft tissue repair occurred when the PBS-hydrogel collagen was implanted. Consistent with these in vivo effects, rCTGF/CCN2 enhanced type II collagen and aggrecan mRNA expression in mouse bone marrow-derived stromal cells and induced chondrogenesis in vitro.
Conclusion: These findings suggest the utility of CTGF/CCN2 in the regeneration of articular cartilage.

DOI： 10.1359/JBMR.040322

The significance of interferon and ribavirin combination therapy followed by interferon monotherapy for patients with chronic hepatitis C in Japan 査読

N Hiramatsu, A Kasahara, F Nakanishi, T Toyama, M Tsujii, S Tsuji, T Kanto, T Takehara, M Kato, H Yoshihara, M Naito, K Katayama, T Hijioka, H Hagiwara, S Kubota, M Oshita, H Meren, M Masuzawa, Y Haruna, E Mita, K Suzuki, N Hayashi

HEPATOLOGY RESEARCH 29 ( 3 ) 142 - 147 2004年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI IRELAND LTD

One hundred seventy-one patients with chronic hepatitis C were included in this study (genotype 1 and high viral loads (1H), n = 130; non-1H, n = 37; N.D., n = 4). The combination therapy of interferon and ribavirin for 24 weeks with an additional 24 weeks of interferon monotherapy (48-week treatment) was undergone by 42 1H patients and 5 non-1H patients. The combination therapy of interferon and ribavirin was administered for 24 weeks in 67 1H patients and 22 non-1H patients. Among the 1H patients, the HCV relapse rate was significantly higher in those receiving 24-week combination treatment than in those receiving 48-week treatment (78% versus 42%, P = 0.003). Among the non-1H patients, no significant difference was found between them. Sustained virological response (SVR) rates were observed to decrease as the timing of HCV RNA disappearance was delayed. In spite of the small rate (16%), SVR was obtained from the patients who became negative for HCV RNA by week 24 (beyond week 12) only in those receiving 48-week treatment. In 1H patients, 24-week combination treatment followed by interferon monotherapy for 24 weeks was concluded to be the treatment offering the most hope among those that the medical insurance can be applied in Japan. (C) 2004 Published by Elsevier B.V.

DOI： 10.1016/j.hepres.2004.03.008

Module-specific antibodies against human connective tissue growth factor: Utility for structural and functional analysis of the factor as related to chondrocytes

M Minato, S Kubota, H Kawaki, T Nishida, A Miyauchi, H Hanagata, T Nakanishi, T Takano-Yamamoto, M Takigawa

JOURNAL OF BIOCHEMISTRY 135 ( 3 ) 347 - 354 2004年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JAPANESE BIOCHEMICAL SOC

Connective tissue growth factor/hypertrophic chondrocyte specific gene product 24 (CTGF/Hcs24/CCN2) shows diverse functions in the process of endochondral ossification. It promotes not only the proliferation and differentiation of chondrocytes and osteoblasts in vitro, but also angiogenesis in vivo. The ctgf gene is a member of the gene family called CCN, and it encodes the characteristic 4-module structure of this family, with the protein containing IGFBP, VWC, TSP and CT modules. We raised several monoclonal antibodies and polyclonal antisera against CTGF, and located the epitopes in the modules by Western blotting. For mapping the epitopes, Brevibacillus-produced independent modules were utilized. As a result, at least 1. antibody or antiserum was prepared for the detection of each module in CTGF. Western blotting with these antibodies is expected to be useful for the analysis of CTGF fragmentation. Moreover, we examined the effects of these monoclonal antibodies on the biological functions of CTGF. One out of 3 humanized monoclonal antibodies was found to neutralize efficiently the stimulatory effect of CTGF on chondrocytic cell proliferation. This particular antibody bound to the CT module. In contrast, surprisingly, all of the 3 antibodies recognizing IGFBP, VWC and CT modules stimulated proteoglycan synthesis in chondrocytic cells. Together with previous findings, these results provide insight into the structural-functional relationships of CTGF in executing multiple functions.

DOI： 10.1093/jb/mvh042

Downregulation of a rheumatoid arthritis-related antigen (RA-A47) by ra-a47 antisense oligonucleotides induces inflammatory factors in chondrocytes

T Hattori, H Kawaki, S Kubota, Y Yutani, B De Crombrugghe, K Von Der Mark, M Takigawa

JOURNAL OF CELLULAR PHYSIOLOGY 197 ( 1 ) 94 - 102 2003年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

Previously we have shown that the expression of RA-A47 (rheumatoid arthritis-related antigen) which is identical to HSP47, a collagen-binding chaperon, is downregulated in chondrocytes by tumor necrosis factor alpha (TNFalpha). RA-A47 was also found on the surface of chondrocytes where it is recognized as an antigen in the serum of rheumatoid arthritis (RA) patients. Its translocation to the cell surface from endoplasmic reticulum membrane where it is normally located was also enhanced by TNFalpha. To understand the significance of RA-A47 downregulation in chondrocytes independent from other effects of TNFalpha, we used an antisense oligonucleotide approach and investigated the effect of this treatment on the expression of molecules related to matrix degradation and production of growth factors for chondrocytic, endothelial, and synovial cells. Here we show that treatment of rabbit chondrocyes and human chondrosarcoma cells HCS-2/8 by ra-a47 antisense S-oligonucleotides significantly reduced the expression of ra-a47 both at mRNA and protein level. Interestingly, this TNFalpha-independent RA-A47 clownregulation was associated with a strong induction of matrix metalloproteinase (MMP)-9 mRNA and inducible NO synthase (iNOS) mRNA. The induction of active-type MMP-9 was further detected by gelatin zymography. Under the same conditions, the release of basic fibroblast growth factor (bFGF) and connective tissue growth factor (CTGF) from HCS-2/8 cells into the conditioned medium (CM) was strongly enhanced. These effects were not a result of TNFalpha upregulation, since the ra-a47 antisense oligonucleotide treatment did not enhance TNFalpha synthesis. These observations indicate that clownregulation of RA-A47 induces TNFalpha-independent cartilage-degrading pathways involving iNOS and MMP-9. Furthermore, the stimulation of bFGF and CTGF release from chondrocytes may stimulate the proliferation of adjacent endothelial and/or synovial cells. (C) 2003 Wiley-Liss, Inc.

DOI： 10.1002/jcp.10341

Novel enzyme-linked immunosorbent assay systems for the quantitative analysis of connective tissue growth factor (CTGF/Hcs24/CCN2): Detection of HTLV-I tax-induced CTGF from a human carcinoma cell line

H Kawaki, S Kubota, M Minato, NH Moritani, T Hattori, H Hanagata, M Kubota, A Miyauchi, T Nakanishi, M Takigawa

DNA AND CELL BIOLOGY 22 ( 10 ) 641 - 648 2003年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MARY ANN LIEBERT INC PUBL

Connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 (CTGF/Hcs24/CCN2) is known as a multifunctional growth factor. It stimulates proliferation, migration, and extracellular matrix production of mesenchymal cells, and is highly expressed in hypertrophic chondrocytes. In this study, we constructed useful ELISA systems for the analysis of CTGF and its modular fragments. For this objective we prepared four different antihuman CTGF monoclonal antibodies. One, specific for the VWC module, was utilized as the detecting antibody, and the other three, recognizing CT, IGFBP, and VWC modules, respectively, were employed as capture antibodies. Then we established three novel quantitative analysis systems for CTGF. The first system recognizing CT and VWC modules was useful to measure full-length CTGF with improved sensitivity. Utilizing this system, we found significant enhancement of CTGF production from a human carcinoma cell line transduced by HTLV-I tax gene, where the finding indicates the possible involvement of Tax in carcinogenesis. The second system, seeing IGFBP and VWC modules, could quantify not only CTGF, but also may be useful to analyze processed N-terminal fragments. The third system, utilizing capture and detection antibodies against the VWC module, was able to quantify the VWC module only, while it did not recognize full-length CTGF. Since CTGF is actually processed into subfragments, and functional assignment of each module is of interest, these systems are expected to contribute to the progress of CTGF investigations.

Transcriptional induction of connective tissue growth factor/hypertrophic chondrocyte-specific 24 gene by dexamethasone in human chondrocytic cells 査読

S Kubota, NH Moritani, H Kawaki, H Mimura, M Minato, M Takigawa

BONE 33 ( 4 ) 694 - 702 2003年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE INC

Connective tissue growth factor (CTGF/Hcs24) is a critical growth factor for chondrocytic growth and differentiation. In this report, we describe for the first time glucocorticoid-mediated induction of the CTGF/Hcs24 gene in a chondrocytic cell line, HCS-2/8. Steady-state mRNA levels of CTGF/Hcs24 were remarkably increased after treatment with 50 nM dexamethasone, as confirmed by Northern blotting and quantitative real-time polymerase chain reaction (PCR) analysis. Corresponding to the increase in mRNA, production of CTGF/Hcs24 protein was remarkably enhanced, following a time course of up to 6 h. The observed increase in mRNA can be ascribed to transcriptional enhancement, since the stability of CTGF/Hcs24 mRNA was not affected by the same concentration of dexamethasone, which was indicated by the results of an mRNA degradation assay. However, unexpectedly, the prototypic ctgf/hcs24 promoter was not responsible for the dexamethasone stimulation, suggesting the glucocorticoid receptor binding site(s) to be elsewhere in the CTGF/Hcs24 gene. Enhancement of the prototypic promoter activity by dexamethasone was observed in murine fibroblastic cells, demonstrating the complexity of the regulatory mechanism of ctgf/hcs24 gene expression. Of importance, dexamethasone at the same concentration significantly stimulated proteoglycan synthesis in HCS-2/8 cells up to the same levels as exogenously added CTGF/Hcs24. These findings represent a novel effect of glucocorticoid on the production of CTGF/Hcs24 by chondrocytic cells, and indicate that CTGF/Hcs24 may mediate the stimulative effect of dexamethasone on chondrocytic phenotypes. Also, our results shed light on the complex mechanism of CTGF/Hcs24 induction by glucocorticoids. (C) 2003 Elsevier Inc. All rights reserved.

DOI： 10.1016/S8756-3282(03)00227-8

Connective tissue growth factor expressed in rat alveolar bone regeneration sites after tooth extraction

M Kanyama, T Kuboki, K Akiyama, K Nawachi, FM Miyauchi, H Yatani, S Kubota, T Nakanishi, M Takigawa

ARCHIVES OF ORAL BIOLOGY 48 ( 10 ) 723 - 730 2003年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Objective: To understand bone regeneration process after tooth extraction could be a clue to develop a new strategy for alveolar bone reconstruction. Recently, accumulated evidences support that connective tissue growth factor (CTGF) is implicated in tissue repair of many tissues. In this study, we investigated the spatial and temporal expression of CTGF in the rat tooth extraction sockets. Design: Five weeks old wild type mate rats (weighing 120 g) were used for this experiment. Expression of CTGF was determined by immunohistochemistry and in situ hybridization in the rat upper molar tooth extraction sockets at 2, 4, 7, 10 and 14 days after tooth extraction. Results: CTGF was expressed strongly in the endothelial. cells migrating into the granulation tissue at the bottom of the sockets during 4 days after tooth extraction. During the reparative process, no apparent chondrocyte-like cell appeared in the sockets, while osteoblast-like cells proliferated in the sockets with low CTGF expression at 7, 10, 14 days after extraction. As expected, no staining was observed with the preimmune rabbit IgG and CTGF sense probe. CTGF may play an important rote in angiogenesis and granulation tissue formation specifically at early heating stage after tooth extraction to initiate alveolar bone repair. Conclusion: CTGF was expressed at early heating stage of the rat tooth extraction wound. (C) 2003 Elsevier Ltd. All. rights reserved.

DOI： 10.1016/S0003-9969(03)00153-5

CTGF/Hcs24/CCN2, hypertrophic chondrocyte-specific gene product, interacts with perlecan in regulating the proliferation and differentiation of chondrocytes.

T Nishida, S Kubota, T Fukunaga, S Kondo, G Yosimichi, T Nakanishi, T Takano-Yamamoto, M Takigawa

JOURNAL OF BONE AND MINERAL RESEARCH 18 S108 - S108 2003年9月

CTGF/Hcs24, hypertrophic chondrocyte-specific gene product, interacts with perlecan in regulating the proliferation and differentiation of chondrocytes 査読

T Nishida, S Kubota, T Fukunaga, S Kondo, G Yosimichi, T Nakanishi, T Takano-Yamamoto, M Takigawa

JOURNAL OF CELLULAR PHYSIOLOGY 196 ( 2 ) 265 - 275 2003年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-LISS

Connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 (CTGF/Hcs24) plays important roles in the control of the proliferation and differentiation of chondrocytes in vitro. To clarify the mechanisms of regulation by CTGF/Hcs24 with respect to cartilage metabolism, we investigated the interaction between CTGF/Hcs24 and heparan sulfate proteoglycan perlecan. An immunofluorescence study showed that CTGF/Hcs24 was colocalized with heparan sulfate and perlecan in human chondrosarcoma-derived chondrocytic cell line HCS-2/8 in vitro. Northern blot analysis showed that perlecan, syndecan-1, -2, and -4 transcripts were detected in HCS-2/8 cells. Particularly, expression of the perlecan gene increased markedly in HCS-2/8 cells by recombinant CTGF/Hcs24 (rCTGF/Hcs24) treatment. We also found that CTGF/Hcs24 interacted with perlecan from HCS-2/8 cells in vitro. Furthermore, CTGF/Hcs24-stimulated gene expression of the aggrecan gene, as well as DNA/proteoglycan synthesis, was diminished when HCS-2/8 cells were pretreated with heparinase, indicating that the effects of CTGF/Hcs24 on chondrocytes occurred through the interaction between CTGF/Hcs24 and heparan sulfate on the cells. An in vivo study using mouse growth plate revealed that CTGF/Hcs24 produced by hypertrophic chondrocytes was localized from the proliferative to the hypertrophic zone, whereas perlecan was predominantly localized in the prehyphertrophic zone. Consistent with such findings in vivo, the binding of I-125-rCTGF/Hcs24 to maturing chondrocytes was at higher levels than that to chondrocytes in hypertrophic stages. These findings suggest that CTGF/Hcs24 produced in the hypertrophic region may act on chondrocytes in the proliferative and maturative zone via some heparan sulfate proteoglycan, such as perlecan. (C) 2003 Wiley-Liss, Inc.

DOI： 10.1002/jpc.10277

Transcriptional induction of connective tissue growth factor hypertrophic chondrocyte-specific 24 gene by dexamethasone in human chondrocytic cells

S Kubota, NH Moritami, H Kawaki, H Mimura, M Minato, M Takigawa

BONE 32 ( 5 ) S98 - S98 2003年5月

Suppressive effect of overexpressed connective tissue growth factor on tumor cell growth in a human oral squamous cell carcinoma-derived cell line

NH Moritani, S Kubota, T Nishida, H Kawaki, S Kondo, T Sugahara, M Takigawa

CANCER LETTERS 192 ( 2 ) 205 - 214 2003年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI IRELAND LTD

Connective tissue growth factor (CTGF) is known to be a multifunctional growth factor that is overexpressed. in several types of malignancies. In this study, effects of CTGF gene overexpression on the phenotypes of oral squamous cell carcinoma cells were investigated by using a cell line with undetectable endogenous CTGF expression. Surprisingly, our results indicated that CTGF-overexpressed clones were characterized by attenuated cell growth and less potent tumorigenicity, with coincidental downregulation of prothymosin a gene. Although CTGF is known to promote cell proliferation in mesenchymal cells, our present results suggest that CTGF acts as a negative regulator of the cell growth in oral squamous cell carcinoma possibly through its interaction with growth modifiers inside the cell. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.

DOI： 10.1016/S0304-3835(02)00718-8

Role of CTGF/HCS24/ecogenin in skeletal growth control

M Takigawa, T Nakanishi, S Kubota, T Nishida

JOURNAL OF CELLULAR PHYSIOLOGY 194 ( 3 ) 256 - 266 2003年3月

記述言語：英語出版者・発行元：WILEY-LISS

Connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 (CTGF/Hcs24) is a multifunctional growth factor for chondrocytes, osteoblasts, and vascular endothelial cells. CTGF/Hcs24 promotes the proliferation and maturation of growth cartilage cells and articular cartilage cells in culture and hypertrophy of growth cartilage cells in culture. The factor also stimulates the proliferation and differentiation of cultured osteoblastic cells. Moreover, CTGF/Hcs24 promotes the adhesion, proliferation, and migration of vascular endothelial cells, as well as induces tube formation by the cells and strong angiogenesis in vivo. Because angiogenesis is critical for the replacement of cartilage with bone at the final stage of endochondral ossification and because gene expression of CTGF/Hcs24 predominates in hypertrophic chondrocytes in the physiological state, a major physiological role for this factor should be the promotion of the entire process of endochondral ossification, with the factor acting on the above three types of cells as a paracrine factor. Thus, CTGF/Hcs24 should be called "ecogenin: endochondral ossification genetic factor." In addition to hypertrophic chondrocytes, osteoblasts activated by various stimuli including wounding also express a significantly high level of CTGF/Hcs24. These findings in conjunction with in vitro findings about osteoblasts mentioned above suggest the involvement of CTGF/Hcs24 in intramembranous ossification and bone modeling/remodeling. Because angiogenesis is also critical for intramembranous ossification and bone remodeling, CTGF/Hcs24 expressed in endothelial cells activated by various stimuli including wounding may also play important roles in direct bone formation. In conclusion, although the most important physiological role of CTGF/Hcs24 is ecogenin action, the factors also play important roles in skeletal growth and modeling/remodeling via its direct action on osteoblasts under both physiological and pathological conditions. (C) 2003 Wiley-Liss, Inc.

DOI： 10.1002/jcp.10206

Conserved repressive regulation of connective tissue growth factor/hypertrophic chondrocyte-specific gene 24 (ctgf/hcs24) enabled by different elements and factors among vertebrate species

Y Mukudai, S Kubota, M Takigawa

BIOLOGICAL CHEMISTRY 384 ( 1 ) 1 - 9 2003年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WALTER DE GRUYTER & CO

CTGF/Hcs24 is a multifunctional growth factor that potentiates the growth and differentiation of various cells. Our previous study revealed that the 3'-UTR of mammalian CTGF/Hcs24 mRNA contains a small segment that represses the gene expression in cis fashion. In this study, we isolated and characterized a chicken CTGF/Hcs24 cDNA clone. Chicken ctgf/hcs24 mRNA showed highly conserved homology in the ORF to that of mammalian species, whereas the homology in the 3'-UTR was relatively low. Northern blotting analysis revealed that chicken ctgf/hcs24 mRNA was expressed most strongly in cartilage, and also in brain, lung, heart, but faintly in liver. Thereafter we analyzed the functional potential of the 3'-UTR of ctgf/hcs24 cDNA to regulate its gene expression by reporter gene assay, and found that it repressed gene expression in cis fashion, specifically in avian cells, but not in mammalian cells. Conversely, the mammalian 3'-UTR showed less repressive activity in avian cells than in mammalian cells. Deletion analysis showed that a segment near the polyadenyl tail of the 3'-UTR of chicken ctgf/hcs24 played an important functional role, unlike in the mammalian species. Thus, we uncovered a novel mode of functional conservation of the ctgf/hcs24 3'-UTR among vertebrate species mediated by different factors.

Interaction of AP-1 and the ctgf gene: a possible driver of chondrocyte hypertrophy in growth cartilage

NH Moritani, S Kubota, T Eguchi, T Fukunaga, T Yamashiro, T Takano-Yamamoto, H Tahara, K Ohyama, T Sugahara, M Takigawa

JOURNAL OF BONE AND MINERAL METABOLISM 21 ( 4 ) 205 - 210 2003年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER-VERLAG TOKYO

The expression of the connective tissue growth factor (ctgf) gene increases along with the differentiation of growth cartilage cells, and the highest expression is observed in the hypertrophic stage. Similarly, recent reports demonstrated c-fos expression in chondrocytes in the early hypertrophic zone of growth cartilage, and suggested that the c-fos gene may play a crucial role in the regulation of hypertrophic differentiation. A chondrocytic human cell line, HCS-2/8, is known to retain a variety of chondrocytic phenotypes. When such cells were kept overconfluent, they expressed increasing levels of c-fos transcripts along a time course phenotypically similar to that of hypertrophic differentiation. Moreover, by using a competitive electromobility-shift assay, we found that AP-1, a Fos/Jun heterodimer, in HCS-2/8 was capable of binding not only to a typical AP-1-binding DNA fragment but also to the enhancer fragment of the ctgf gene. Based on the findings above, we hypothesize that, prior to hypertrophic differentiation, AP-1-related oncogenes are activated and that their gene products subsequently activate ctgf gene expression, which might eventually induce hypertrophy.

DOI： 10.1007/s00774-003-0410-1

　前のページ - 次のページ　

1
2
3
4
5
6
7
8
9
10
11
12