| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1998: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Inducible nitric oxide synthase (iNOS) has been implicated in development and maintenance of many inflammatory diseases. We at first demonstrated that in cultued vascular smooth muscls cells (VSMC), the LPS-induced iNOS expression is almost totally dependent on the LPS-induced production of inter leukin 1beta (IL- 1beta) which then induces iNOS gene expression in an autocrine fashion. Therefore, we further studied the signal transduction mechanisms involved in the IL-1 receptor activation iNOS gene expression pathway. Protein kinase C (PKC) family, involved in the transmission of a wide variety of extracellular signals, is classified into three groups ; conventinal (cPKC), novel (nPKC) and atypical (aPKC). We identified 5 isozymes, alpha (cPKC), delta, epsilon(nPKC), iota and lambda(aPKC) in VSMC with Western blot technique. The PKCalpha knockdown by antisense-oligodeoxynucleotide (AS -ODN) against PKCalpha mRNA depleted PKCalpha without any effect on the other types of the isozymes, and inhibited iNOS mRNA production stimulated by IL-1beta by about 50 %, but had no influence on NF-kappaB translocation by IL-1beta. On the other hand, a selective PKC inhibitor Ro31-8220, which could not discriminate among the PKC isozymes, did not inhibit NF-kappaB translocation but abolished IL-1beta-stimulated iNOS gene expression. These results suggest that IL-1 receptor activation transmits signals in a PKC-dependent manner : about 50 % of the activity was due to the PKCalpha species, and that NF-kappaB translocation may not be necessary for iNOS gene expression initiated by IL-1beta.
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