Molecular mechanism vascular remodeling and blood pressure regulation by orphan receptor, and theraputic

孤儿受体血管重塑和血压调节的分子机制及治疗

• 批准号: 12557064
• 负责人: HORIUCHI Masatsugu
• 金额: $ 8.26万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12557064/
• 关键词: Vascular remodeling; Cardiac hypertrohy; Transcription factor; Gene transfer; Renin; LXR; RXR; c-mvc; クローニング; 心血管リモデリング; エンハンサー; サイレンサー; C-myc; cAMP; おとり型核酸医薬(デコイ)療法

Renin, an enzyme important in cardiovascular homeostasis, is regulated by cAMP. Our previous studies suggested that renin gene expression is regulated, at least partly, by a novel as acting DNA element (CNRE) in the gene's 5'-flanking region. We demonstrate here that a CNRE binding protein is the mouse homologue of human LXRa using a yeast one-hybrid cloning system. LXRα is a member of the superfamily of nuclear receptor regulators of transcription and functions as a heterodimer with RXRα, another member of this family. To examine the function of LXRα on the expression of renin gene, we transfected the renin-producing renal As4.1 cells with LXRα expression plasmid. Transient overexpression of LXRα in As4.1 cells confers cAMP inducibility to reporter constructs containing the CNRE. Moreover, following stable transfection of LXRα, As4.1 cells show a cAMP-inducible upregulation of renin mRNA expression with a significant increase in nuclear binding activity to CNRE, which is antagonized b … More y an anti-LXRα antibody. Interestingly, LXRα can also bind to the homologous CNRE in the c-myc promoter and mediate cAMP-inducible c-myc expression. The identification of LXRα as a novel cAMP responsive nuclear modulator of renin and c-myc gene expression should provide new insights not only into its role in nuclear receptor-signaling pathway, but also in the understanding of cardiovascular pathophysiology. To examine the pathophysiological roles of LXRα in cardiovascular remodeling, we employed polyethylene cuff-induced vascular injury model in me femoral artery mouse model. We found that LXRα was transactivated associated with the increase in the expression of c-myc and renin, and neointimal hyperplasia. We also observed that LXRα was upregulated in pressure-overload-induced cardiac hypertrophy in mice. Moreover, we demonstrated that activation of renin-angiotensin system is important in the cardiovascular remodeling in these mouse models. These results suggest the pathophysiological importance of LXRα in cardiovascular remodeling and LXRα can be a future target for gene therapy for cardiovascular diseases. Less

肾素是一种在心血管稳态中重要的酶，受cAMP调节。我们以前的研究表明，肾素基因的表达至少部分地受到该基因5 '侧翼区的一个新的作为作用的DNA元件（CNRE）的调控。我们在这里使用酵母单杂交克隆系统证明了CNRE结合蛋白是人类LXR的小鼠同源物。LXRα是核受体转录调节因子超家族的成员，与该家族的另一个成员RXRα形成异源二聚体。为研究LXRα对肾素基因表达的影响，我们将LXRα表达质粒转染肾细胞系As4.1，观察LXRα对肾素基因表达的影响。LXRα在As4.1细胞中的瞬时过表达使cAMP诱导含有CNRE的报告基因构建体。此外，在稳定转染LXRα后，As4.1细胞显示cAMP诱导的肾素mRNA表达上调，同时细胞核与CNRE的结合活性显著增加，这被B拮抗。 ...更多信息 y抗LXR α抗体。有趣的是，LXRα还可以结合c-myc启动子中的同源CNRE，并介导cAMP诱导的c-myc表达。LXRα作为一种新型的cAMP反应性核调节剂，可调节肾素和c-myc基因的表达，这不仅为研究其在核受体信号通路中的作用提供了新的视角，而且对心血管病理生理学的研究也具有重要意义。为了研究LXRα在心血管重构中的病理生理作用，我们在小鼠股动脉模型中采用聚乙烯袖套诱导的血管损伤模型。我们发现LXRα的反式激活与c-myc和renin的表达增加以及新生内膜增生有关。我们还观察到LXRα在压力超负荷诱导的小鼠心肌肥大中上调。此外，我们证明了在这些小鼠模型中，肾素-血管紧张素系统的激活在心血管重构中是重要的。这些结果提示LXRα在心血管重构中具有重要的病理生理学意义，LXRα有望成为心血管疾病基因治疗的新靶点。少

项目成果

Suzuki, J., Iwai, M., Nakagami, H., Wu, L., Chen, R., Sugaya, T., Hamada, M., Hiwada, K., Horiuchi, M.: "Role of angiotensin II-regulated apoptosis via distinct AT1 and AT2 receptors in neointimal formation"Circulation. 106. 847-853 (2002)

Suzuki, J.、Iwai, M.、Nakagami, H.、Wu, L.、Chen, R.、Sugaya, T.、Hamada, M.、Hiwada, K.、Horiuchi, M.：“血管紧张素 II 的作用

Tamura, K., Y.E.Chen, Horiuchi, M., Q.Chen, Z.Yang, Daviet, L., H.Mu, Pratt, R.E. and Dzau, V.J.: "A novel function of LXRα as a cAMP-responsive transcriptional regulator of renin"Proc Natl Acad Sci USA. 97. 8513-8518 (2000)

Tamura, K.、Y.E.Chen、Horiuchi, M.、Q.Chen、Z.Yang、Daviet, L.、H.Mu、Pratt, R.E. 和 Dzau, V.J.：“LXRα 作为 cAMP 响应性转录的新功能肾素调节剂“Proc Natl Acad Sci USA. 97. 8513-8518 (2000)

Tamura,K.,Y.E.Chen.,Horiuchi,M.,Q,Chen.,Z,Yang.,Daviet,L.,H,Mu.,Pratt,R.E.and Dzau,V.J.: "A novel function of LXRα as a cAMP-responsive transcriptional regulator of renin."Proc.Natl.Acad,Sci.USA.. 97. 8513-8518 (2000)

Tamura, K., Y.E.Chen., Horiuchi,M.,Q,Chen.,Z,Yang.,Daviet,L.,H,Mu.,Pratt,R.E. 和 Dzau,V.J.：“LXRα 作为肾素的 cAMP 反应性转录调节因子。“Proc.Natl.Acad,Sci.USA.. 97. 8513-8518 (2000)

Wu, L., Iwai, M., Nakagami, H., Chen, R., Suzuki, J., Akishita, M., de Gasparo, M., Horiuchi, M.: "Effect of AT1 receptor blockade on cardiac remodeling in AT2 receptor mull mice"Arteriosclero Thromb Vasc Biol. 22. 49-54 (2002)

Wu, L.、Iwai, M.、Nakagami, H.、Chen, R.、Suzuki, J.、Akishita, M.、de Gasparo, M.、Horiuchi, M.：“AT1 受体阻断对心脏重构的影响

Liu, H-W., Iwai, M., Takeda-Matsubara, Y., Wu, L., Li, J-M., Okumura, M., Cui, T-X, Horiuchi, M.: "Effect of estrogen and the AT1 receptor blocker on neointima formation"Hypertension. 40. 451-457 (2002)

Liu, H-W.、Iwai, M.、Takeda-Matsubara, Y.、Wu, L.、Li, J-M.、Okumura, M.、Cui, T-X、Horiuchi, M.：“雌激素和 AT1 受体阻滞剂的作用