| Project/Area Number |
18591655
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Orthopaedic surgery
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
MIURA Toshiki (2007) The University of Tokyo, Faculty of Medicine, Assistant Professor (20376479)
深井 厚 (2006) 東京大学, 医学部附属病院, 助手 (20422298)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAKAYAMA Shuichi The University of Tokyo, Faculty of Medicine, Assistant Professor (80401066)
HARA Nobuhiro The University of Tokyo, Faculty of Medicine, Assistant Professor (00422296)
OGATA Naoshi The University of Tokyo, Faculty of Medicine, Visiting Assistant Professor (10361495)
KAWANO Hirotaka The University of Tokyo, Faculty of Medicine, Lecturer (20345218)
三浦 俊樹 東京大学, 医学部附属病院, 助教 (20376479)
|
|---|
| Project Period (FY) |
2006 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥3,590,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥390,000)
Fiscal Year 2007: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2006: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
|---|
| Keywords | Osteoarthritis / Canonical Wnt signaling / TCF / LEF-1 / Hypertrophy / Sox9 |
|---|
| Research Abstract |
To better understand the role of the canonical Wnt signaling pathway in cartilage development and Osteoarthritis (OA) condition, we adenovirally expressed a constitutively active (ca) or a dominant negative (dn) form of lymphoid enhancer factor-1 (LEF-1), the main nuclear effecter of the pathway, in undifferentiated mesenchymal cells, chondrogenic cells and primary chondrocytes, and examined the expression of markers for chondrogenic differentiation and hypertrophy. caLEF-1 and LiCl, an activator of the canonical pathway, promoted both chondrogenic differentiation and hypertrophy, whereas dnLEF-1 and the gene silencing of β-catenin suppressed LiCl promoted effects. To investigate whether these effects were dependent on Sox9, a master regulator of cartilage development, we stimulated Sox9-deficient ES cells with the pathway. caLEF-1 and LiCl promoted both chondrogenic differentiation and hypertrophy in wild-type but not in Sox9-deficient cells. The response of Sox9-deficient cells was restored by the adenoviral expression of Sox9. Thus, the canonical Wnt signaling pathway promotes chondrocyte differentiation in a Sox9-dependent manner. Next, In vivo experiment, mouse OA model was created by surgical transection of the medial collateral ligament and resection of the medial meniscus of the knee joints of wild-type. Cartilage destruction and osteophyte formation in the medial tibial cartilage were compared by histologic and radiographic analyses. Expression of type X collagen, TCF/LEF-1 and β-catenin was examined by immunohistochemistry. TCF/LEF-1 was induced in the articular cartilage of wild-type mice at the early stage of OA, almost simultaneously with type X collagen as compared with wild-type mice. These in vivo results perform similar functions with that RUNX-2 contributes to the pathogenesis of OA through chondrocyte hypertrophy and matrixbreakdown after the induction of joint instability (Our group published).
|
