| Project/Area Number |
11670447
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
内科学一般
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| Research Institution | Kobe University |
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Principal Investigator |
KOSHIBA Masahiro Kobe University School of Medicine, Assistant Professor (Lecturer), 医学部, 講師 (70301827)
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| Co-Investigator(Kenkyū-buntansha) |
KUMAGAI Shunichi Kobe University School of Medicine, Professor, 医学部, 教授 (00153346)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | rheumatoid arthritis / adenosine / purinergic receptors / adenosine transporter / adjuvant arthritis / apoptosis / therapy / caspase / アデノシンA2B受容体 / サイクリックAMP / 細胞増殖 |
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| Research Abstract |
1) Effects of Extracellular Adenosine on Human Synovial Cells
2-Chloroadenosine (2-CADO), an adenosine deaminase (ADA) resistant general Adenosine (Ado) agonist, induced the apoptosis on the fibroblast-like synoviocytes (FLS) from rheumatoid arthritis (RA) patients (RA-FLS) in a dose-dependent manner. Incubation of FLS with Ado resulted in the inhibition of proliferation as early as an hour, which was time- and concentration-dependent.
2) Expression of Cell-surface Adenosine Receptors on FLS
RT-PCR assay revealed that RA-FLS and two human FLS lines expressed all the four Adenosine Receptors (AdoR) mRNA (A_1, A_<2A>, A_<2B> and A_3). Functional analysis using the selective AdoR agonists and antagonists revealed that cAMP-increasing A_<2B> AdoR was functionally dominant on FLS.
3) Molecular Mechanisms of Adenosine-mediated Apoptosis on FLS
A potent ado transporter inhibitor NBT, but the selective AdoR antagonists, suppressed the RA-FLS apoptosis bar 2-CADO.Incubation with cell-permeable cAMP analog or co-incubation of Ado with ADA inhibitor also failed to inhibit the apoptosis, while general caspase inhibitor z-VAD-fmk was capable of blocking the apoptosis. These data indicated the machinery that the exogenous 2-CADO after entering into the cells activated the caspases and induced the apoptotic cell death.
4) Anti-rheumatic Effect of Adenosine Transporter Inhibitors in vivo
The results mentioned above opened the possibility of the ado transporter inhibitors as novel ant-rheumatic drugs. We have started to test this in rat adjuvant arthritis model. The preliminary results were that the systemic administration of NBT appears similarly or even more effective than methotrexate. Thus the further in vivo investigation of the anti-rheumatic effects of NBT and other nucleoside transporters will open a new therapeutic strategy of RA.
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