Roles of Voltage- and cation-independent TRPC channels in cardiac hypertrophy

电压和阳离子无关的 TRPC 通道在心脏肥大中的作用

基本信息

批准号：
20390025
负责人：
KUROSE Hitoshi
金额：
$ 12.48万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-20390025/
关键词：
心肥大 TRPCチャネルリン酸化 cGMP ホスホジエステラーゼ阻害剤圧負荷 cGMP依存性タンパク質リン酸化酵素ホスホジエステラーゼ5阻害剤圧負荷ストレス cAMP依存性リン酸化酵素 cGMP依存性リン酸化酵素細胞内Ca^<2+>制御選択的阻害剤化合物Pyr3 圧負荷モデル

项目摘要

We have reported that angiotensin II or endothelin-1 stimulation induce hypertrophic responses through transient receptor potential canonical channel 3 (TRPC3) and TRPC6-mediated Ca2+ influx using rat neonatal cardiomyocytes. TRPC3/TRPC6 are voltage-independent and cation-non-selective ion channels, and activated by diacylglycerol generated by Gq-stimulated phospholipase C activation. However, these results were obtained from in vitro cell system using receptor stimulation of cardiomyocytes isolated from newborn rats. It is essential to demonstrate the importance of TRPC3/TRPC6 in in vivo hypertrophy model. Therefore, we have examined whether TRPC3/TRPC6 are involved in pressure overload-induced cardiac hypertrophy. Pressure overload is considered as a mouse model of chronic human hypertension, and induces cardiac hypertrophy. As the compound Pyr3 that selectively inhibits TRPC3 was available, we obtained it and administered to pressure overloaded mice. Pressure overload is applied by … More transverse aortic constriction procedure (TAC), and Pyr3 is administered by osmotic mini-pump. Pressure overload-induced hypertrophy was inhibited in Pyr3-treated mice as compare to wild type mice, which was as assessed by increased size of cardiomyocytes and increased expression of ANP. Furthermore, cardiac function such as fractional shortening is improved by the treatment with Pyr3. Next, we also examined the involvement of TRPC6 in pressure overload-induced cardiac hypertrophy. As the function of TRPC6 is inhibited by phosphorylation of TRPC6, we used a cGMP-selective phosphodiesterase (phosphodiesterase type 5:PDE5) inhibitor, sildenafil, for the increase in cardiac cGMP content. The treatment with sildenafil inhibited cardiac hypertrophy by pressure overload. The increased expression of various marker genes of hypertrophy was inhibited by the treatment with sildenafil. In sidenafil-treated mice, anti-phospho-TRPC6 antibody revealed that TRPC6 was phosphorylated at a specific site that is essential for TRPC6-mediated Ca^<2+> influx. These results suggest that TRPC3/TRPC6-mediated Ca^<2+> influx plays an important role in cardiac hypertrophy in vivo as well as in vitro. Less

我们报道了血管紧张素II或内皮素-1模拟通过瞬态受体潜在的规范通道3（TRPC3）和TRPC6介导的CA2+使用大鼠新生儿心肌细胞诱导肥厚的反应。 TRPC3/TRPC6是不依赖电压的和阳离子 - 非选择性离子通道，并由GQ刺激的磷脂酶C激活产生的二酰基甘油激活。但是，使用从新生大鼠分离的心肌细胞的受体刺激从体外细胞系统中获得这些结果。重要的是要证明在体内肥大模型中TRPC3/TRPC6的重要性。因此，我们检查了TRPC3/TRPC6是否参与压力超负荷引起的心脏肥大。压力超负荷被认为是慢性人类高血压的小鼠模型和诱导的心脏肥大。由于可以选择性地抑制TRPC3的化合物PYR3，因此我们获得了并给予压力超载小鼠。压力超负荷是通过…更多的横向主动脉收缩程序（TAC）施加的，而PyR3由渗透微型泵施用。与野生型小鼠相比，在PYR3处理的小鼠中抑制了压力超负荷引起的肥大，这是通过心肌细胞尺寸增加和ANP表达增加所评估的。此外，用pyr3的处理可以改善心脏功能，例如分数缩短。接下来，我们还检查了TRPC6参与压力超负荷引起的心脏肥大。由于TRPC6的磷酸化抑制了TRPC6的功能，因此我们使用了CGMP选择性磷酸二酯酶（磷酸二酯酶5：PDE5）抑制剂Sildenafil，以增加心脏CGMP含量的增加。西地那非治疗通过压力超负荷抑制心肥力。用二氧化硅凝胶处理抑制了各种肥大标记基因的表达增加。在西多纳非治疗的小鼠中，抗磷酸-TRPC6抗体表明TRPC6在特定位点磷酸化，这对于TRPC6介导的Ca^<2+>影响是必不可少的。这些结果表明，TRPC3/TRPC6介导的CA^<2+>影响在体内和体外在心脏肥大中起着重要作用。较少的