| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
|
|---|
| Research Abstract |
[Purpose] Hypoxia-inducible factor I (HW-1) is originally identified as a nuclear factor that is induced by hypoxia and bound to a site in the erythropoietin (Epo) hypoxia-response element (HRE). HIF-1 plays an important role in 02 homeostasis by activating transcription of genes whose' products mediate essential cellular and systemic response to hypoxia, including erythropoiesis, glycolysis, vasculogenesis, and vasodilatation. The aim of this study is to clarify hypoxia response of pulmonary arterial (PA) endothelium by addition of genetic modification to secrete reporter gene (Re) product following adenovirus-mediated transfer of both Re cDNA and hypoxia response cis-element. [Method] To evaluate hypoxia response of PA endothelium, two type of adenovirus vector were constructed. One adenovirus vector contains Re expression cassette with hypoxia response cis element (HRE) isolated from Epo genome (AdHRE), and the other one is adenovirus vector containing Re expression cassette without
… More
HRE (Ad) as control vector. Using these vectors, hypoxia response of PA endothelium, aortic endothelium was evaluated by using the ratio of production of Re product in exposure to hypoxia and normoxia. [Results) Each Ad treated-endothelium exposed to hypoxia had no increase in the ratio of Re production, compared with Ad treated endothelium in normoxia. In marked contrast, AdHRE-infected PA endothelium exposed to hypoxia had an increase in the ratio of Re production, 4 fold compared with AdHRE infected PA endothelium in normoxia (p<O.OOl). Furthermore, interestingly, AdHRE infected endothelium in distal PA exposed to hypoxia had a significantly large increase in the ratio of Re production, 2 fold compared with AdHRE infected endotbeliuxn in proximal PA exposed to hypoxia (p<O.OOl). To evaluate hypoxia response in different type of endothelium, aortic endothelium was exposed to hypoxia following treatment with AdHERE.AdHRE-treated-aortic endothelium has a plateau in the ratio of Re production 12 hrs following the exposure to hypoxia, 4 or 2 fold compared with AdHRE-treated each endothelium in normoxia. [Conclusion] Analysis system of hypoxia response was established by using adenovirus-mediated transfer of hypoxia response cis element. Our current study using this HRE transfer system demonstrated that hypoxia response of PAE showed larger than that of AE of systemic circulation, especially endothelium in distal PA relevant to vascular remodeling had a markedly larger hypoxia response. This HRE- gene transfer system was feasible to evaluate disorder of hypoxia response in circulatory or pulmonary diseases. Less
|
