| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
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| Research Abstract |
Immunohistochemical studies revealed that a serine proteinase inhibitor B-43 purified and cloned from bovine brain was present in the neurons medium to large in size in the bovine brain, especially in the brain stem and the spinal cord. The B-43-immunoreactive neurons contained motor nuclei in the pons and medulla oblongata, motor neurons in the anterior spinal cord, pyramidal cells in the cerebral cortex, pyramidal cells in the hippocampus CA 3 regions and large neurons in the striatum. beta-43 was also localized in GFAP-positive astrocytes. Recombinant B-43 labeled with [35S]-methionine formed SDS-stable complexes with thrombin, trypsin, nerve growth factor and kallikrein. GST-B-43 fusion protein concentration-dependently inhibited the amidolytic activity of thrombin, trypsin and alpha-chymotrypsin but not elastase, These results suggested that thrombin and trypsin-like serine proteinase were the preferred target proteinases of B-43. The mouse homolog (P1-6) of bovine B-43 was cloned. Northern blot analysis showed a high level of expression of Pl-S mRNA in brain stem and diencephalon as compared with other regions in the adult brain, The expression of Pl-6 mRNA in the Whole brain was increased gradually until 11 days after birth and was decreased again in the adult brain. In situ hybridization analysis revealed that the mRNA was localized in pyramidal cell layer of the post-natal hippocampus, especially in CA 3 region, and layer V of the cerebral cortex. In the brain stem, the facial nucleus and the motor nucleus of trigeminal nerve were strongly positive for Pl-6 mRNA.Brain ischemia induced by bilateral ligation of the common carotid artery led to an increase in Pl-6 mRNA expression, accompanied by the degeneration of hippocampal pyramidal cells. These results suggested the involvement of PI-6/B-43 in the maturation of neurons and degenerative and regenerative processes.
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