| Co-Investigator(Kenkyū-buntansha) |
IKEMOTO Kazuhisa Fujita Health University, School of Medicine, Assistant, 医学部, 助手 (40351019)
SHIRAISHI Hiroaki Fujita Health University, School of Medicine, Assistant, 医学部, 助手 (80319285)
NOMURA Takahide Fujita Health University, School of Medicine, Professor, 医学部, 教授 (20156227)
ICHINOSE Hiroshi Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, Professor, 大学院・生命理工学研究科, 教授 (90192492)
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| Research Abstract |
Tetrahydrobiopterin (BH4) synthesized from GTP In viva Is an essential cofactor for phenylalanine hydroxylase which converts phenylalanin to tyrosirie, tyrosine hydroxylase and tryptophan hydroxylase which are rate-limiting enzymes for catecholamine and serotonin biosynthesis, respectively. Also BH4 is known as a cofactor for nitric oxide synthase.
1,We established 6-pyruvoyltetrahydropterin synthase (PTPS) knockout (PTPS-KO) mice by gene targeting, which catalyzes the second step of BH4 biosynthesis, previously. In this project we grafted the thymus from PTPS-KO embryos to nude mice, and also grafted blood stem cells to radiated CsilsL/6 mice. We analyzed differentiated lymphocytes, by surface antigens by FACS, mixture assay, PEA assay, LPS and ConA stimulation. However, we did not detect significant difference between lymphocytes from homozygotes and those from wild types.
2,We Injected BH4, L-DOPA and 5-HTP Intraperitonealy to PTPS-KO neonates respectively and assayed monoamine contents, TH and TPH activity. In the brain of L-DOPA and 5-HTP Injected mice, monoamine content rapidly elevated and was metabolized, compare to BH4 supplementation.
3,We established several transgenlc mice lines using human PTPS cDNA under the control of 5.8 kb mouse dopamine β-hydroxylase genomic promoter (DPS). A DPS transgenlc line crossed to PTPS-KO heteroxygotes and successively rescued them after weaning (PTPS-KO, DPSG). PTPS-KO, DPS6 mice showed evident developmental retardation. BW of PTPS-KO, DPS6 is 60 % of those of wild type littermates. In 8 to 12 weeks, plasma phenylalanine content of PTPS-KO, DPS6 mice were 37.4 times higher than those of wild type mice.
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