| Co-Investigator(Kenkyū-buntansha) |
YAO Atsushi Faculty of Medicine, University of Tokyo, Medical staff, 医学部・附属病院, 医員
HARADA Kazumasa Faculty of Medicine, University of Tokyo, Medical staff, 医学部・附属病院, 医員
MATSUI Hiroshi Faculty of Medicine, University of Tokyo, Assistant, 医学部・附属病院, 助手 (30282669)
SHIMIZU Tatsuya Faculty of Medicine, University of Tokyo, Medical staff, 医学部・附属病院, 医員
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| Research Abstract |
The objective of this project was to elucidate functional significance of hypoxia-inducible factor 1α (HIF-1α), a member of the basic-helix-loop-helix-Per/ARNT/Sim (bHLH-PAS) protein family, in the ischemic-reperfused myocardium. Particularly, we analyzed expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS), which are among target genes of HIF-1α, in cardiac myocytes.
1) Analyses of VEGF expression in cardiac myocytes : Using cultured neonatal rat myocytes, we have observed that expression of VEGF was augmented by lipopolysaccaharide (LPS) (Sugishita Y, et al. Biochem Biophys Res Commun, 2000) or adenosine (via its A_2 receptor). On the other hand, we have analyzed expression of the chick VEGF in cultured 10-day-old chick embryonic ventricular myocytes (CEVM) (Sugishita Y, et al. J Mol Cell Caardiol, 2000).
2) Analyses of the chick iNOS gene expression in CEVM : We have obtained the data showing that both NF-κB and Ets-1 are involved in the LPS-induced transactivation of the chick iNOS geen in CEVM (Takahashi T, et al. Mol Cell Biochem, submitted).
3) Molecular cloning and expressional analyses of the chick HIF-1α cDNA in CEVM : We have cloned cDNAs encoding the chick HIF-1α from CEVM with RT-PCR and Race methods. We then examined expression of the chick HIF-1α mRNA species in various embryonic tissues. The deduced amino acid sequence of the chick HIF-1α cDNA showed 79% identity with that of the human HIF-1α cDNA.In contrast, sequence homology between the chick HIF-1α and endothelial PAS protein 1 (EPAS1), another member of the bHLH-PAS proteins, was only low (49%). HIF-1α mRNA was expressed abundantly in CEVM, but scarcely in the liver, which was quite different from expression pattem of EPAS1 mRNA.These data suggest that HIF-1α may be involved in embryonic cardiovascular development (Takahashi T, et al. Biochem Biophys Res Commun, 2001, in press).
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