Faculty Profiles - EGUCHI Takanori

Promoter Analyses of CCN Genes

Takanori Eguchi, Satoshi Kubota, Masaharu Takigawa

Methods in Molecular Biology 177 - 185 2017

Cellular Reprogramming Using Defined Factors and MicroRNAs. Reviewed International journal

Takanori Eguchi, Takuo Kuboki

Stem cells international 2016 7530942 - 7530942 2016

Authorship：Lead author,　Corresponding author Language：English Publisher：Hindawi Publishing Corporation

Development of human bodies, organs, and tissues contains numerous steps of cellular differentiation including an initial zygote, embryonic stem (ES) cells, three germ layers, and multiple expertized lineages of cells. Induced pluripotent stem (iPS) cells have been recently developed using defined reprogramming factors such as Nanog, Klf5, Oct3/4 (Pou5f1), Sox2, and Myc. This outstanding innovation is largely changing life science and medicine. Methods of direct reprogramming of cells into myocytes, neurons, chondrocytes, and osteoblasts have been further developed using modified combination of factors such as N-myc, L-myc, Sox9, and microRNAs in defined cell/tissue culture conditions. Mesenchymal stem cells (MSCs) and dental pulp stem cells (DPSCs) are also emerging multipotent stem cells with particular microRNA expression signatures. It was shown that miRNA-720 had a role in cellular reprogramming through targeting the pluripotency factor Nanog and induction of DNA methyltransferases (DNMTs). This review reports histories, topics, and idea of cellular reprogramming.

DOI： 10.1155/2016/7530942

A Novel High-Throughput 3D Screening System for EMT Inhibitors: A Pilot Screening Discovered the EMT Inhibitory Activity of CDK2 Inhibitor SU9516. Reviewed International journal

Kazuya Arai, Takanori Eguchi, M Mamunur Rahman, Ruriko Sakamoto, Norio Masuda, Tetsuya Nakatsura, Stuart K Calderwood, Ken-Ichi Kozaki, Manabu Itoh

PloS one 11 ( 9 ) e0162394 2016

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：PUBLIC LIBRARY SCIENCE

Epithelial-mesenchymal transition (EMT) is a crucial pathological event in cancer, particularly in tumor cell budding and metastasis. Therefore, control of EMT can represent a novel therapeutic strategy in cancer. Here, we introduce an innovative three-dimensional (3D) high-throughput screening (HTS) system that leads to an identification of EMT inhibitors. For the establishment of the novel 3D-HTS system, we chose NanoCulture Plates (NCP) that provided a gel-free micro-patterned scaffold for cells and were independent of other spheroid formation systems using soft-agar. In the NCP-based 3D cell culture system, A549 lung cancer cells migrated, gathered, and then formed multiple spheroids within 7 days. Live cell imaging experiments showed that an established EMT-inducer TGF-β promoted peripheral cells around the core of spheroids to acquire mesenchymal spindle shapes, loss of intercellular adhesion, and migration from the spheroids. Along with such morphological change, EMT-related gene expression signatures were altered, particularly alteration of mRNA levels of ECAD/CDH1, NCAD/CDH2, VIM and ZEB1/TCF8. These EMT-related phenotypic changes were blocked by SB431542, a TGF-βreceptor I (TGFβR1) inhibitor. Inside of the spheroids were highly hypoxic; in contrast, spheroid-derived peripheral migrating cells were normoxic, revealed by visualization and quantification using Hypoxia Probe. Thus, TGF-β-triggered EMT caused spheroid hypoplasia and loss of hypoxia. Spheroid EMT inhibitory (SEMTIN) activity of SB431542 was calculated from fluorescence intensities of the Hypoxia Probe, and then was utilized in a drug screening of EMT-inhibitory small molecule compounds. In a pilot screening, 9 of 1,330 compounds were above the thresholds of the SEMTIN activity and cell viability. Finally, two compounds SB-525334 and SU9516 showed SEMTIN activities in a dose dependent manner. SB-525334 was a known TGFβR1 inhibitor. SU9516 was a cyclin-dependent kinase 2 (CDK2) inhibitor, which we showed also had an EMT-inhibitory activity. The half maximal inhibitory concentration (IC50) of SB-525334 and SU9516 were 0.31 μM and 1.21 μM, respectively, while IC50 of SB431542 was 2.38 μM. Taken together, it was shown that this 3D NCP-based HTS system was useful for screening of EMT-regulatory drugs.

DOI： 10.1371/journal.pone.0162394

Targeting the hsp70 gene delays mammary tumor initiation and inhibits tumor cell metastasis Reviewed

J. Gong, D. Weng, T. Eguchi, A. Murshid, M. Y. Sherman, B. Song, S. K. Calderwood

ONCOGENE 34 ( 43 ) 5460 - 5471 2015.10

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

Elevated levels of the inducible heat-shock protein 70 (Hsp72) have been implicated in mammary tumorigenesis in histological investigations of human breast cancer. We therefore examined the role of Hsp72 in mice, using animals in which the hsp70 gene was inactivated. We used a spontaneous tumor system with mice expressing the polyomavirus middle T (PyMT) oncogene under control of the mouse mammary tumor virus (MMTV) long-terminal repeat (MMT mice). These mice developed spontaneous, metastatic mammary cancer. We then showed Hsp72 to be upregulated in a fraction of mammary cancer initiating cells (CIC) within the MMT tumor cell population. These cells were characterized by elevated surface levels of stem cell markers CD44 and Sca1 and by rapid metastasis. Inactivation of the hsp70 gene delayed the initiation of mammary tumors. This delay in tumor initiation imposed by loss of hsp70 was correlated with a decreased pool of CIC. Interestingly, hsp70 knockout significantly reduced invasion and metastasis by mammary tumor cells and implicated its product Hsp72 in cell migration and formation of secondary neoplasms. Impaired tumorigenesis and metastasis in hsp70-knockout MMT mice was associated with downregulation of the met gene and reduced activition of the oncogenic c-Met protein. These experiments therefore showed Hsp72 to be involved in the growth and progression of mammary carcinoma and highlighted this protein as a potential target for anticancer drug development.

DOI： 10.1038/onc.2015.1

Role and Regulation of Myeloid Zinc Finger Protein 1 in Cancer. Reviewed International journal

Taka Eguchi, Thomas Prince, Barbara Wegiel, Stuart K Calderwood

Journal of cellular biochemistry 116 ( 10 ) 2146 - 54 2015.10

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Myeloid zinc finger 1 (MZF1) belongs to the SCAN-Zinc Finger (SCAN-ZF) transcription factor family that has recently been implicated in a number of types of cancer. Although the initial studies concentrated on the role of MZF1 in myeloid differentiation and leukemia, the factor now appears to be involved in the etiology of major solid tumors such as lung, cervical, breast, and colorectal cancer. Here we discuss the regulation of MZF1 that mediated its recruitment and activation in cancer, concentrating on posttranslational modification by phosphorylation, and sumoylation, formation of promyelocytic leukemia nuclear bodies and its association with co-activators and co-repressors.

DOI： 10.1002/jcb.25203

HSF1 regulation of β-catenin in mammary cancer cells through control of HuR/elavL1 expression. Reviewed International journal

Shiuh-Dih Chou, Ayesha Murshid, Takanori Eguchi, Jianlin Gong, Stuart K Calderwood

Oncogene 34 ( 17 ) 2178 - 2188 2015.4

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

There is now compelling evidence to indicate a place for heat shock factor 1 (HSF1) in mammary carcinogenesis, tumour progression and metastasis. Here we have investigated a role for HSF1 in regulating the expression of the stem cell renewal factor β-catenin in immortalized human mammary epithelial and carcinoma cells. We found HSF1 to be involved in regulating the translation of β-catenin, by investigating effects of gain and loss of HSF1 on this protein. Interestingly, although HSF1 is a potent transcription factor, it was not directly involved in regulating levels of β-catenin mRNA. Instead, our data suggest a complex role in translational regulation. HSF1 was shown to regulate levels of the RNA-binding protein HuR that controlled β-catenin translation. An extra complexity was added to this scenario when it was shown that the long non-coding RNA molecule lincRNA-p21, known to be involved in β-catenin mRNA (CTNNB1) translational regulation, was controlled by HSF1 repression. We have shown previously that HSF1 was positively regulated through phosphorylation by mammalian target of rapamycin (mTOR) kinase on a key residue, serine 326, essential for transcriptional activity. In this study, we found that mTOR knockdown not only decreased HSF1-S326 phosphorylation in mammary cells, but also decreased β-catenin expression through a mechanism requiring HuR. Our data point to a complex role for HSF1 in the regulation of HuR and β-catenin expression that may be significant in mammary carcinogenesis.

DOI： 10.1038/onc.2014.177

OstemiR: A Novel Panel of MicroRNA Biomarkers in Osteoblastic and Osteocytic Differentiation from Mesencymal Stem Cells

Eguchi, Takanori, Hara, Emilio Satoshi, Ono, Mitsuaki, Watanabe, Ken, Kuboki, Takuo, Calderwood, Stuart

Faseb Journal 29 ( 3 ) e58796 2015

miRNA-720 regulates the stem cell phenotype and differentiation of human dental pulp-derived mesenchymal stromal cells

Hara, Emilio Satoshi, Ono, Mitsuaki, Eguchi, Takanori, Hai Thanh Pham, Tajima, Shoji, Calderwood, Stuart K., Matsumoto, Takuya, Kuboki, Takuo, IEEE

2014 International Symposium on Micro-Nanomechatronics and Human Science (Mhs) 1 - 2 2014

Stress proteins in aging and life span. Reviewed International journal

Ayesha Murshid, Takanori Eguchi, Stuart K Calderwood

International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group 29 ( 5 ) 442 - 7 2013.8

Language：English Publishing type：Research paper (scientific journal) Publisher：INFORMA HEALTHCARE

Heat shock proteins (HSP) are molecular chaperones and have been implicated in longevity and aging in many species. Their major functions include chaperoning misfolded or newly synthesised polypeptides, protecting cells from proteotoxic stress, and processing of immunogenic agents. These proteins are expressed constitutively and can be induced by stresses such as heat, oxidative stress and many more. The induction of HSP in aging could potentially maintain protein homeostasis and longevity by refolding the damaged proteins which accumulate during aging and are toxic to cells. HSP are shown to increase life span in model organisms such as Caenorhabditis elegans and decrease aging-related proteotoxicity. Thus, decrease in HSP in aging is associated with disruption of cellular homeostasis which causes diseases such as cancer, cell senescence and neurodegeneration. HSP levels are decreased with aging in most organs including neurons. Aging also causes attenuation or alteration of many signalling pathways as well as the expression of transcription factors such as heat shock factor (HSF). The alteration in regulation and synthesis of Forkhead box O3a (FoxO3a) family of transcription factors as well as major antioxidant enzymes (manganese superoxide dismutase, catalase) are also seen in aging. Among many signalling mechanisms involved in altering longevity and aging, the insulin/IGF-1 pathway and the Sir2 deacetylase are highly significant. This review enquires into the role of some of these pathways in longevity/aging along with HSP.

DOI： 10.3109/02656736.2013.798873

miRNA-720 controls stem cell phenotype, proliferation and differentiation of human dental pulp cells. Reviewed International journal

Emilio Satoshi Hara, Mitsuaki Ono, Takanori Eguchi, Satoshi Kubota, Hai Thanh Pham, Wataru Sonoyama, Shoji Tajima, Masaharu Takigawa, Stuart K Calderwood, Takuo Kuboki

PloS one 8 ( 12 ) e83545 2013

Language：English Publishing type：Research paper (scientific journal)

Dental pulp cells (DPCs) are known to be enriched in stem/progenitor cells but not well characterized yet. Small non-coding microRNAs (miRNAs) have been identified to control protein translation, mRNA stability and transcription, and have been reported to play important roles in stem cell biology, related to cell reprogramming, maintenance of stemness and regulation of cell differentiation. In order to characterize dental pulp stem/progenitor cells and its mechanism of differentiation, we herein sorted stem-cell-enriched side population (SP) cells from human DPCs and periodontal ligament cells (PDLCs), and performed a locked nucleic acid (LNA)-based miRNA array. As a result, miR-720 was highly expressed in the differentiated main population (MP) cells compared to that in SP cells. In silico analysis and a reporter assay showed that miR-720 targets the stem cell marker NANOG, indicating that miR-720 could promote differentiation of dental pulp stem/progenitor cells by repressing NANOG. Indeed, gain-and loss-of-function analyses showed that miR-720 controls NANOG transcript and protein levels. Moreover, transfection of miR-720 significantly decreased the number of cells positive for the early stem cell marker SSEA-4. Concomitantly, mRNA levels of DNA methyltransferases (DNMTs), which are known to play crucial factors during stem cell differentiation, were also increased by miR-720 through unknown mechanism. Finally, miR-720 decreased DPC proliferation as determined by immunocytochemical analysis against ki-67, and promoted odontogenic differentiation as demonstrated by alizarin red staining, as well as alkaline phosphatase and osteopontin mRNA levels. Our findings identify miR-720 as a novel miRNA regulating the differentiation of DPCs.

DOI： 10.1371/journal.pone.0083545

Role of LRP1 in transport of CCN2 protein in chondrocytes. Reviewed International journal

Kazumi Kawata, Satoshi Kubota, Takanori Eguchi, Eriko Aoyama, Norifumi H Moritani, Seiji Kondo, Takashi Nishida, Masaharu Takigawa

Journal of cell science 125 ( Pt 12 ) 2965 - 72 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：COMPANY OF BIOLOGISTS LTD

Low-density lipoprotein receptor-related protein 1 (LRP1) is known to be a receptor for signal transmission and endocytosis. We have previously reported that LRP1 regulates WNT-β-catenin and protein kinase C signaling in chondrocytes, represses the hypertrophy of chondrocytes during endochondral ossification and that LRP1 is colocalized with a ligand, CCN family member 2 (CCN2; also known as connective tissue growth factor, CTGF), which conducts endochondral ossification, in chondrocytes. However, the role of LRP1 in the endocytic transport of CCN2 in chondrocytes is not yet understood. In the present study, we investigated the interaction between LRP1 and CCN2 during endocytic trafficking. Small interfering RNA (siRNA)-mediated knockdown of LRP1 in chondrocytic HCS-2/8 cells showed that the amount of exogenous CCN2 binding and/or incorporation was decreased in the LRP1 downregulated cells. Importantly, we observed that CCN2 internalization in chondrocytes was dependent on clathrin, and internalizated CCN2 was colocalized with an early or recycling endosome marker. Transcytosis of CCN2 through HCS-2/8 cells was confirmed by performing experiments with a trans-well apparatus, and the amount of transcytosed CCN2 was decreased by an LRP1 antagonist. These findings rule out possible leakage and confirm the crucial involvement of LRP1 during experimental transcytosis. Moreover, under hypoxic conditions that mimic the cartilaginous microenvironment, the level of LRP1 and the amount of transcytosed CCN2 increased, and these increases were neutralized by treatment with the LRP1 antagonist. The distribution of LRP1 and its antagonist in the growth plate in vivo was consistent with that of CCN2 in this tissue, which is produced by and transported by LRP1 from the chondrocytes in the prehypertrophic layer. These findings suggest that LRP1 mediates the transcytosis of CCN2, which might be a crucial event that determines the distribution of CCN2 in cartilage.

DOI： 10.1242/jcs.101956

Role of low-density lipoprotein receptor related protein 1 (LRP1) in CCN2/connective tissue growth factor (CTGF) protein transport in chondrocytes Reviewed

Kawata., K, Kubota, S, Eguchi, T, Aoyama, E, Moritani, N, Kondo, S, Nishida, T, Takigawa, M

J Cell Sci 15 2965 - 2972 2012

低密度リポタンパク受容体関連タンパク1(LRP1)による軟骨細胞でのCCNファミリー2/結合組織成長因子(CCN2/CTGF)タンパク質輸送

河田かずみ, 久保田聡, 江口傑徳, 青山絵理子, 近藤誠二, 滝川正春

日本結合組織学会学術大会・マトリックス研究会大会合同学術集会プログラム・抄録集 43回・58回 76 - 76 2011.5

A coding RNA segment that enhances the ribosomal recruitment of chicken ccn1 mRNA. Reviewed International journal

Yoshiki Mukudai, Satoshi Kubota, Takanori Eguchi, Kumi Sumiyoshi, Danilo Janune, Seiji Kondo, Satoru Shintani, Masaharu Takigawa

Journal of cellular biochemistry 111 ( 6 ) 1607 - 18 2010.12

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

CCN1, a member of the CCN family of proteins, plays important physiological or pathological roles in a variety of tissues. In the present study, we initially found a highly guanine-cytosine (GC)-rich region of approximately 200 bp near the 5'-end of the open reading frame, which was always truncated by amplification of the corresponding cDNA region through the conventional polymerase chain reaction. An RNA in vitro folding assay and selective ribonuclease digestion of the corresponding segment of the ccn1 mRNA confirmed the involvement of a stable secondary structure. Subsequent RNA electromobility-shift assays demonstrated the specific binding of some cytoplasmic factor(s) in chicken embryo fibroblasts to the RNA segment. Moreover, the corresponding cDNA fragment strongly enhanced the expression of the reporter gene in cis at the 5'-end, but did not do so at the 3'-end. According to the results of a ribosomal assembly test, the effect of the mRNA segment can predominantly be ascribed to the enhancement of transport and/or entry of the mRNA into the ribosome. Finally, the minimal GC-rich mRNA segment that was predicted and demonstrated to form a secondary structure was confirmed to be a functional regulatory element. Thus, we here uncover a novel dual-functionality of the mRNA segment in the ccn1 open reading frame, which segment acts as a cis-element that mediates posttranscriptional gene regulation, while retaining the information for the amino acid sequence of the resultant protein.

DOI： 10.1002/jcb.22894

軟骨細胞のCCN2蛋白質輸送における低比重リポ蛋白受容体関連蛋白質1(LRP1)の役割(Role of the low-density lipoprotein receptor related protein 1 (LRP1) in CCN2 protein transportation in chondrocytes)

河田かずみ, 久保田聡, 江口傑徳, 青山絵理子, 近藤誠二, 滝川正春

日本生化学会大会・日本分子生物学会年会合同大会講演要旨集 83回・33回 2T10 - 12 2010.12

低密度リポタンパク受容体関連タンパク1(LRP1)による軟骨細胞でのタンパク質輸送

河田かずみ, 久保田聡, 江口傑徳, 青山絵理子, 近藤誠二, 滝川正春

日本骨代謝学会学術集会プログラム抄録集 28回 188 - 188 2010.7

Role of the low-density lipoprotein receptor-related protein-1 in regulation of chondrocyte differentiation. Reviewed International journal

Kazumi Kawata, Satoshi Kubota, Takanori Eguchi, Norifumi H Moritani, Tsuyoshi Shimo, Seiji Kondo, Takashi Nishida, Shogo Minagi, Masaharu Takigawa

Journal of cellular physiology 222 ( 1 ) 138 - 48 2010.1

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-LISS

The low-density lipoprotein receptor-related protein 1 (LRP1) is known as an endocytic and signal transmission receptor. We formerly reported the gene expression and the localization of LRP1 in cartilage tissue and chondrocytes, but its roles in the differentiation of chondrocytes remained to be investigated. Here, in order to address this issue, we employed RNAi strategy to knockdown lrp1 in chondrocytic cells and obtained findings indicating a critical role therein. As a result of lrp1 knockdown, aggrecan and col2a1 mRNA levels were decreased. However, that of col10a1 or mmp13 mRNA was rather increased. Under this condition, we performed a promoter assay for Axin2, which is known to be induced by activation of the WNT/beta-catenin (betacat) signaling pathway. Thereby, we found that Axin2 promoter activity was enhanced in the lrp1 knockdown cells. Furthermore, when the WNT/beta-catenin pathway was activated in chondrocytic cells by WNT3a or SB216763, which inhibits the phosphorylation of GSK3beta, the mRNA levels of aggrecan and col2a1 were decreased, whereas that of mmp13 was increased. Additionally, the level of phosphorylated protein kinase C (PKC) zeta was also decreased in the lrp1 knockdown cells. When the phosphorylation of PKCzeta was selectively inhibited, aggrecan and col2a1 mRNA levels decreased, whereas the mmp13 mRNA level increased. These data demonstrate that LRP1 exerts remarkable effects to retain the mature phenotype of chondrocytes as a critical mediator of cell signaling. Our findings also indicate that the onset of hypertrophy during endochondral ossification appears to be particularly dependent on the WNT and PKC signaling initiated by LRP1.

DOI： 10.1002/jcp.21930

Nucleophosmin/B23: A Multifunctional Regulator that Determines the Fate of CCN2 mRNA

Satoshi Kubota, Yoshiki Mukudai, Harumi Kawaki, Seiji Kondo, Takanori Eguchi, Kumi Sumiyoshi, Toshihiro Ohgawara, Tsuyoshi Shimo, Masaharu Takigawa

CCN PROTEINS IN HEALTH AND DISEASE: AN OVERVIEW OF THE FIFTH INTERNATIONAL WORKSHOP ON THE CCN FAMILY OF GENES 41 - + 2010

Language：English Publishing type：Research paper (international conference proceedings) Publisher：SPRINGER-VERLAG BERLIN

CCN2/CTGF is a multifunctional molecule that has been shown to play a central role in chondrocyte differentiation. During this process, the expression of ccn2 is tightly regulated to confer a maximal level at prehypertrophic - hypertrophic stages, in which the 3'-untranslated region (UTR) of the mRNA is critically involved in mediating its post-transcriptional regulation. In our previous studies, we found that a 40-kDa protein binding specifically to an RNA cis-element, 3'-100/50, in the 3'-UTR of the chicken ccn2 mRNA regulated the intracellular stability of the mRNA. The interaction of this 40-kDa protein with 3'-100/50 was enhanced in proliferating chondrocytes, in which ccn2 mRNA is rapidly degraded; whereas a prolonged half life of ccn2 mRNA is observed in hypertrophic chondrocytes, where the interaction of the 40 kDa-protein and 3'-100/50 is diminished. Collectively, the data suggested that this 40-kDa protein acts as a ccn2-specific mRNA destabilizer during chondrocyte differentiation.
In this present study we finally identified this 40-kDa protein as nucleophosmin (NPM)/B23. NPM is a nuclear-cytoplasmic shuttling protein that is characterized by its multiple functionality. This protein is known to be a histone chaperone, a regulator of ribosomal RNA transcription, as well as an RNA-binding post-transcriptional regulator of gene expression. In our hands, direct binding of NPM to 3'-100/50 was confirmed not only by RNA EMSA and UV crosslinking assays, but also by RNA immunoprecipitation analysis. By using recombinant chicken NPM, we could successfully reconstitute the post-transcriptional regulation of ccn2 by NPM in vitro and found that this regulation was more robust in chondrocytes than in fibroblasts. Furthermore, siRNA-mediated gene silencing of NPM in vivo clearly showed enhanced ccn2 gene expression and a prolonged half life of the ccn2 mRNA, confirming the functional property of NPM as a specific destabilizer of the ccn2 mRNA in living cells.
The 5'-100/50 element, a target of NPM, is evolutionally conserved among vertebrate species. Therefore, we consider NPM to be a critical post-transcriptional regulator of ccn2 acting via 3'-UTR during endochondral ossification and possibly, in other physiological and pathological states as well.

DOI： 10.1007/978-90-481-3779-4_4

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Novel Transcriptional Regulation of CCN2/CTGF by Nuclear Translocation of MMP3

Other Link： http://orcid.org/0000-0002-9600-4430

Takanori Eguchi, Satoshi Kubota, Kazumi Kawata, Yoshiki Mukudai, Junji Uehara, Toshihiro Ohgawara, Soichiro Ibaragi, Akira Sasaki, Takuo Kuboki, Masaharu Takigawa

CCN PROTEINS IN HEALTH AND DISEASE: AN OVERVIEW OF THE FIFTH INTERNATIONAL WORKSHOP ON THE CCN FAMILY OF GENES 255 - + 2010

Authorship：Lead author Language：English Publishing type：Research paper (international conference proceedings) Publisher：SPRINGER-VERLAG BERLIN

CCN2/CTGF, previously known as Connective Tissue Growth Factor, is a crucial regulator of extra-cellular matrix (ECM), which promotes ECM synthesis and stabilization. As their family name clearly implies, matrix metalloproteases (MMPs) are also localized in the ECM, where they function as proteases, modulating cell signaling by cleaving proteins such as matrix proteins, growth factors and growth factor receptors. Strong expression of CCN2/CTGF in chondrocytic cells occurs through transcription enhancer dominant in chondrocytes (TRENDIC). Matrix metalloprotease-3 (MMP3) is a novel TRENDIC-binding transcription factor for CCN2/CTGF expression. First, MMP3 cDNA was cloned as a TRENDIC-binding factor by Southwestern screening. The interaction between MMP3 and TRENDIC was confirmed by a gel shift assay and chromatin immunoprecipitation. The CCN2/CTGF promoter was activated by transfected MMP3, whereas a TRENDIC mutant for the promoter lost the response. In addition, the knockdown of MMP3 suppressed CCN2/CTGF expression. Cytochemical and histochemical analyses demonstrated that MMP3 was detected in the nuclei of chondrocytic cells in culture and also in the nuclei of normal and osteoarthritic chondrocytes in vivo. The nuclear translocation of externally added recombinant MMP3 was observed in 30 min after the addition, and six putative nuclear localization signals were found in MMP3. These results indicated a novel trans-activation mechanism of CCN2/CTGF by the nuclear translocation of MMP3 through binding with TRENDIC in chondrocytes. Although MMPs historically had been recognized as a protease for extra-cellular proteins, this study indicated that it also stimulates ECM synthesis through CCN2/CTGF trans-activation. This novel regulatory role of the ECM may contribute to understanding the mechanism of not only the development, but also the pathogenesis of arthritis fibrosis and periodontitis.

DOI： 10.1007/978-90-481-3779-4_19

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