Grant-in-Aid for International Scientific Research.
|Section||Joint Research .|
|Research Institution||KYOTO UNIVERSITY|
NAKAO Kazuwa Kyoto Univ., Graduate School of Medicine.Professor, 医学研究科, 教授 (00172263)
細田 公則 京都大学, 総合人間学部, 助手 (40271598)
MUKOYAMA Masashi Kyoto Univ., Graduate School of Medicine, Asist.Professor, 医学研究科, 助手 (40270558)
斎藤 能彦 京都大学, 医学研究科, 助手 (30250260)
ITOH Hiroshi Kyoto Univ., Graduate School of Medicine, Asist.Professor, 医学研究科, 助手 (40252457)
TANAKA Issei Kyoto Univ., Graduate School of Medicine, Assoc.Professor, 医学研究科, 助教授 (80179738)
GANTEN Detle マックスデルブリュック医学研究所, 所長
BURNETT John メーヨークリニック, 心臓腎臓研究所, 教授
YANAGISAWA M テキサス大学, 医学部, 教授
INAGAMI Tada バンダービルト大学, 医学部, 教授
VUCTIR J Dza ハーバード大学, 医学部, 教授
DZAU VictorJ ハーバード大学, 医学部, 教授
DZAU Victor J Harvard Medical School, Department of Medicine, Chairman
INAGAMI Tadashi Vanderbilt University, School of Medicine, Professor
|Project Fiscal Year
1996 – 1996
Completed(Fiscal Year 1996)
|Budget Amount *help
¥7,500,000 (Direct Cost : ¥7,500,000)
Fiscal Year 1996 : ¥7,500,000 (Direct Cost : ¥7,500,000)
|Keywords||Natriuretic peptide / Endothelin / Angiotensin receptor / Cardiovascular hormone / Molecular biology / Knockout mouse / Transgenic mouse / Gene transfer / ナトリウム利尿ペプチド / エンドセリン / アンジオテンシン受容体 / 心臓血管ホルモン / 分子生物学 / ノックアウトマウス / トランスジェニックマウス / 遺伝子導入|
Recent studies have shown that novel' cardiovascular hormones' may be implicated in various cardiovascular disorders such as hypertension and myocardial infarction. To further explore their roles, we studied the natriuretic peptide system, endothelin system, and renin-angiotensin system at the molecular level in clinical and experimental settings, including genetically engineered animal models.
Endothelial production of C-type natriuretic peptide (CNP), possessing vasorelaxant and antiproliferative properties, was markedly increased through TGF-BETA activation under coculture with vascular smooth muscle cells (VSVC), and was significantly decreased by vascular endothelial growth factor or insulin. Furthermore, the G1 arrest was induced by adenovirus-mediated CNP gene transfer into VSMC,and CNP induced an antiproliferative homeobox Gax as opposed to the effect of angiotensinII.Thus, these Multiple mediators may be interacting locally in vascular remodeling, being potential targets for ca
rdiovacular gene therapy. We also showed that transgenic mice overexpressing brain natriuretic peptide(BNP) exhibited significant hypotension with decreased cardiac mass, suggesting its cardioprotective effect. We further revealed that the BNP and ANP genes are organized in tandem in the mouse and humangenomes.
We also revealed the presence of short nonfunctional forms of the endothelin-A receptor in various human tissues by alternative RNA splicing, suggesting a regulatory role in its gene expression.
Angiotensin II type 2(AT_2) receptor was abundantly expressed in human myometrium and markedly down-regulated during pregnancy, suggesting its role in uterine function. In cultured rat mesangial cells, the AT_2 receptor was markedly induced upon confluency and exerted an antiproliferative effect, counteracting the AT_1 receptor. Lower expression of the AT_2 receptor in genetically hypertensive rat kidneys suggested its implication in pathogenesis of hypertension. Furthermore, in hypertensive transgenic rats overexpressing mouse renin (Ren-2), cardiac secretion of ANP and BNP upon stimulation was attenuated, suggesting its contribution to their cardiovascular complications. Less