| Project/Area Number |
13671483
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Orthopaedic surgery
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
OHTSU Susumu Tohoku University School of Med. Research Associate, 大学院・医学系研究科, 助手 (90312553)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOKUBUN Shoichi Tohoku University School of Med. Professor, 大学院・医学系研究科, 教授 (60186658)
ITOH Tsunetoshi Tohoku University School of Med. Professor, 大学院・医学系研究科, 教授 (90004746)
OONUMA Masahiro Tohoku University Hospital, Research Associate, 医学部附属病院, 助手 (90344663)
|
|---|
| Project Period (FY) |
2001 – 2002
|
| Project Status |
Completed (Fiscal Year 2002)
|
| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
|
|---|
| Keywords | Rheumatoid arthritis / v-ATPase / synovial cell |
|---|
| Research Abstract |
The release of acidic components by H^+ ATPases is an important prerequisite for the decalcification of bone. Apart from the ubiquitously expressed vacuolar (v)- ATPase that is also found on the ruffled membrane of osteoclasts, isoforms of this v-ATPase have been found on the surface of some non-osieoclastic cells. Based on evidence suggesting that activated fibroblasts release acidic components and are able to resorb bone actively, we studied the expression of this osteoclast-like v-ATPase previously called kidney type (ATP6B1) in rheumatoid arthritis synovial fibroblasts (RA-SF), osteoarthritis (OA)-SF and prosthesis loosening fibroblasts (PLF).
RT-PCR revealed the expression of B subunit mRNA for the kidney type v-ATPase in all samples. However, quantitative real time PCR showed considerable differences in the expression between RA-SF, OA-SF and PLF. Specifically, RA-SF showed a 2.6 fold increase in the v-ATPase expression as compared to OA-SF, and v-ATPase levels in PLF were increased 103.2-fold compared to OA-SF. In situ hybridization demonstrated the expression of the v-ATPase in fibroblasts but not in CD68^+ macrophages or in endothelial cells of all tissues. Again, the staining was most intense in the APL samples. The stimulation with acidic medium adjusted to pH 6.0 and pH 5.0 significantly enhanced the expression of ATP6B1, whereas II- 1β and IL-6 showed no influence on this mRNA levels.
We conclude that the increased expression of v-ATPases may be part of the cellular activation seen in RA-SF and PLF. In addition, extensive upregulation of the expression of this osteoclast-like v-ATPase in PLF may be caused by tbe acidic environment and not inflammatory cytokines.
|
