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Koichi Murata, Toshiyuki Kitaori,
Shinya Oishi,
Naoki Watanabe,
Hiroyuki Yoshitomi,
Shimei Tanida,
Masahiro Ishikawa,
Takashi Kasahara,
Hideyuki Shibuya,
Nobutaka Fujii,
Takashi Nagasawa,
Takashi Nakamura,
Hiromu Ito
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ABSTRACT: Stromal cell-derived factor 1 (SDF-1/CXCL12/PBSF) plays important roles in the biological and physiological functions of haematopoietic and mesenchymal stem cells. This chemokine regulates the formation of multiple organ systems during embryogenesis. However, its roles in skeletal development remain unclear. Here we investigated the roles of SDF-1 in chondrocyte differentiation. We demonstrated that SDF-1 protein was expressed at pre-hypertrophic and hypertrophic chondrocytes in the newly formed endochondral callus of rib fracture as well as in the growth plate of normal mouse tibia by immunohistochemical analysis. Using SDF-1(-/-) mouse embryo, we histologically showed that the total length of the whole humeri of SDF-1(-/-) mice was significantly shorter than that of wild-type mice, which was contributed mainly by shorter hypertrophic and calcified zones in SDF-1(-/-) mice. Actin cytoskeleton of hypertrophic chondrocytes in SDF-1(-/-) mouse humeri showed less F-actin and rounder shape than that of wild-type mice. Primary chondrocytes from SDF-1(-/-) mice showed the enhanced formation of philopodia and loss of F-actin. The administration of SDF-1 to primary chondrocytes of wild-type mice and SDF-1(-/-) mice promoted the formation of actin stress fibers. Organ culture of embryonic metatarsals from SDF-1(-/-) mice showed the growth delay, which was recovered by an exogenous administration of SDF-1. mRNA expression of type X collagen in metatarsals and in primary chondrocytes of SDF-1(-/-) mouse embryo was down-regulated while the administration of SDF-1 to metatarsals recovered. These data suggests that SDF-1 regulates the actin organization and stimulates bone growth by mediating chondrocyte hypertrophy.
PLoS ONE 01/2012; 7(5):e37163. · 4.09 Impact Factor
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ABSTRACT: Prostaglandin E2 (PGE2) is one of pro-inflammatory mediators. PGE2 maintains the homeostasis of many organs including articular cartilage, and a previous report showed that continuous inhibition of PGE2 accelerates the progression of osteoarthritis (OA). While PGE2 inhibits matrix metalloprotease (MMP) expression in several types of cells, little is known on direct effects of PGE2 on MMP expression in articular chondrocytes. The objective of this study was to investigate direct effects of PGE2 on IL-1beta-induced MMP-1 and MMP-13 expression and the intracellular signaling in articular chondrocytes. PGE2 showed inhibitory effects on IL-1beta-induced MMP-1 and MMP-13 expression demonstrated by immunoblotting both in OA and normal chondrocytes, which was further confirmed by enzyme-linked immunosorbent assay and immunohistochemistry of explant cultures of articular cartilages. An EP4 agonist, ONO-AE1-329, mimicked the inhibitory effect of PGE2, while an EP4 antagonist, ONO-AE3-208, blocked the effects. PGE2 suppressed the phosphorylation of JNK and ERK MAP kinases, but only knockdown of JNK by specific siRNA mimicked the effect of PGE2. PGE2 further inhibited the phosphorylation of MKK4 without suppression of MKK7 phosphorylation, and of c-JUN to decrease expression levels of MMP-1 and MMP-13. These results demonstrate that PGE2 inhibits IL-1beta-induced MMP-1 and MMP-13 productions via EP4 by suppressing MKK4-JNK MAP kinase-c-JUN pathway.
Journal of Cellular Biochemistry 12/2009; 109(2):425-33. · 2.87 Impact Factor
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ABSTRACT: Although a notable amount of CCL20 is detectable in the synovial fluid of human rheumatoid arthritis (RA), its role in the pathogenesis of RA remains to be determined. IL-1beta vigorously induced the production of CCL20 from FLSs of human RA and the production of CCL20 induced by TNF-alpha was partially attributed to a trace amount of IL-1beta induced by TNF-alpha. Although IL-6 failed to induce CCL20, TNF-alpha-induced IL-6 enhanced the production of CCL20 in an autocrine/paracrine manner. To determine the role of CCL20 and its sole receptor CCR6 in the recruitment of mononuclear cells (MNCs) into the inflamed joint of RA, conditioned medium of IL-1beta-stimulated FLSs was used in migration assays. The conditioned medium significantly recruited CCR6(+) MNCs in a CCL20-dependent manner. The production of CCL20 induced by TNF-alpha and IL-1beta was modified by helper-T-cell-derived cytokines. Interestingly, CCL20 enhanced the production of IL-6 coordinately with the stimulation of IL-17 but not with that of IFN-gamma. These findings imply FLSs stimulated by proinflammatory cytokines recruit CCR6(+) MNCs including IL-17-producing-helper T cells into the inflamed joint, leading to the enhancement of the production of CCL20, which chemokine and IL-17 coordinately induce proinflammatory cytokines.
Cytokine 07/2009; 47(2):112-8. · 3.02 Impact Factor
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ABSTRACT: We report a case of 43-year-old woman with an overlap syndrome of systemic lupus erythematosus (SLE) and dermatomyositis who developed erosive arthritis with extracapsular cysts involving multiple joints. An extensive synovectomy for the left wrist joint and a total joint replacement for the right hip joint were required to achieve complete symptom relief. She was not diagnosed with rheumatoid arthritis (RA). This was a rare case of SLE manifesting non-RA erosive arthritis that required surgical interventions.
Modern Rheumatology 05/2009; 19(4):431-6. · 1.58 Impact Factor
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ABSTRACT: Stromal cell-derived factor 1 (SDF-1; CXCL12/pre-B cell growth-stimulating factor) is a dominant chemokine in bone marrow and is known to be involved in inflammatory diseases, including rheumatoid arthritis. However, its role in bone repair remains unknown. The purpose of this study was to investigate the role of SDF-1 and its receptor, CXCR4, in bone healing.
The expression of SDF-1 during the repair of a murine structural femoral bone graft was examined by real-time polymerase chain reaction and immunohistochemical analysis. The bone graft model was treated with anti-SDF-1 neutralizing antibody or TF14016, an antagonist for CXCR4, and evaluated by histomorphometry. The functional effect of SDF-1 on primary mesenchymal stem cells was determined by in vitro and in vivo migration assays. New bone formation in an exchanging-graft model was compared with that in the autograft models, using mice partially lacking SDF-1 (SDF-1(+/-)) or CXCR4 (CXCR4(+/-)).
The expression of SDF1 messenger RNA was increased during the healing of live bone grafts but was not increased in dead grafts. High expression of SDF-1 protein was observed in the periosteum of the live graft. New bone formation was inhibited by the administration of anti-SDF-1 antibody or TF14016. SDF-1 increased mesenchymal stem cell chemotaxis in vitro in a dose-dependent manner. The in vivo migration study demonstrated that mesenchymal stem cells recruited by SDF-1 participate in endochondral bone repair. Bone formation was decreased in SDF-1(+/-) and CXCR4(+/-) mice and was restored by the graft bones from CXCR4(+/-) mice transplanted into the SDF-1(+/-) femur, but not vice versa.
SDF-1 is induced in the periosteum of injured bone and promotes endochondral bone repair by recruiting mesenchymal stem cells to the site of injury.
Arthritis & Rheumatism 03/2009; 60(3):813-23. · 7.87 Impact Factor
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ABSTRACT: Gene therapy is a promising clinical tool that is no longer limited as a method to supplement genetic deficits, but rather is considered reliable for delivering proteins to specific tissues or cells. Recombinant adeno-associated virus (rAAV) vector is one of the most potent gene transfer vehicles. Many biomaterials have been used in reconstructive surgery, but their biological inactivity has limited their use. To overcome shortcomings of available bone-related biomaterials, we investigated the combination of rAAV with biomaterials. Taking advantage of the method of lyophilizing rAAV onto biomaterials, we showed that an rAAV coating successfully induced beta-galactosidase protein expression by rat fibroblasts on hydroxyapatite, beta-tricalcium phosphate, and titanium alloy in vitro. beta-Galactosidase expression was detected for 8 weeks after implantation of rAAV-coated hydroxyapatite into rat back muscles in vivo. A coating of bone morphogenetic protein-2-expressing rAAV induced significant de novo bone formation on hydroxyapatite in rat back muscles. Our study demonstrates that the combination of lyophilized rAAV and biomaterials presents a promising strategy for bone regenerative medicine.
Journal of Orthopaedic Research 03/2009; 27(9):1162-8. · 2.81 Impact Factor
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ABSTRACT: A novel femoral intramedullary plug with a sliding mechanism has been developed and evaluated clinically. The new plug consists of a pair of specially designed components, each shaped like an obliquely cut cylinder. Postoperative plain radiographs of 30 arthroplasties using the plug were examined for cement leakage, plug migration, and radiolucent line formation between the cement and the femoral cortex. Plugging was complete in 22 cases. Leakage of the cement was seen in 4 cases, and migration of the plug was seen in the other 4 cases. Our study showed the efficacy of the plug in occluding the femoral canal completely in 14 of 22 cases. The plug appears to be promising for clinical applications, because it has good biocompatibility and can occlude the femoral canal tightly.
The Journal of Arthroplasty 05/2003; 18(3):367-70. · 2.38 Impact Factor
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Toshiyuki Kitaori
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ABSTRACT: Kyoto University (京都大学) 0048 新制・課程博士 博士(医学) 甲第14906号 医博第3391号 新制/医/978 27344 UT51-2009-M820 2009-09-24 京都大学大学院医学研究科外科系専攻 (主査)教授 戸口田 淳也, 教授 開 祐司, 教授 鈴木 茂彦 学位規則第4条第1項該当
