Influence of Stim1 on TRPC post-translational modulation and cardiac hypertrophy

描述（由申请人提供）：典型瞬时受体电位（TRPC）通道与钙调神经磷酸酶-活化T细胞核因子（Cn-NFAT）信号传导介导的适应不良性心脏肥大相关。然而，对通道活动的调节还没有很好地理解。我们的实验室已经报道了PKG磷酸化抑制TRPC 6活性的一种调节机制。在HEK293细胞中的研究表明TRPC通道活性也可以通过门控基质相互作用蛋白-1（Stim1）来调节，该蛋白最近被报道有助于体内的肥大反应。初步数据表明，Stim1和TRPC 6通道耦合可能会影响PKG抑制通道。这项工作有可能促进我们对心脏肥大和随后的心力衰竭的分子机制的理解。通过更好地了解TRPC通道的调节，这在心脏病理学的实验和模型中很重要，并且在人类心脏病中也被上调，我们将了解有关治疗靶点的线索。我们假设STIM1与心肌细胞中的TRPC 3和TRPC 6通道相互作用，导致NFAT介导的钙离子进入和肥大信号增加。此外，我们认为心肌细胞中Stim1和TRPC 3/6通道的偶联阻止了PKG磷酸化。我们将通过检查离体心肌细胞中的钙内流来测试这一点，并在体内探索心脏肥大的啮齿动物模型中Stim1和TRPC通道之间的相互作用。 公共卫生相关性：经典瞬时电位受体（TRPC）通道在心力衰竭的发生中发挥作用。目前尚不清楚在心脏病理学背景下通道活性是如何调节的，但基质相互作用分子1（Stim1）可能发挥重要作用。我们试图探索这种关系，并获得对心力衰竭发展的洞察力，以确定抑制该过程的方法。

DESCRIPTION (provided by applicant): Canonical transient receptor potential (TRPC) channels are linked in maladaptive cardiac hypertrophy mediated by calcineurin-nuclear factor of activated T cells (Cn- NFAT) signaling. Yet, the regulation of channel activity is not well understood. Our lab has reported on one regulatory mechanism of by which PKG phosphorylation inhibits TRPC6 activity. Studies in HEK293 cells indicate TRPC channel activity may also be modulated by gating of stromal interacting protein-1 (Stim1) which was recently reported to contribute to the hypertrophic response in vivo. Preliminary data suggests that Stim1 and TRPC6 channel coupling may influence PKG inhibition of the channel. The proposed work has the potential to advance our understanding of the molecular mechanisms of cardiac hypertrophy and subsequent heart failure. By better understanding the modulation of TRPC channels, which are important in experimental and models of cardiac pathology and are also upregulated in human heart disease, we will learn clues about targets for therapy. We hypothesize that STIM1 interacts with TRPC3 and TRPC6 channels in the cardiomyocyte leading to increased calcium entry and hypertrophic signaling mediated by NFAT. Additionally, we propose that the coupling of Stim1 and TRPC3/6 channels in the cardiomyocyte prevents PKG phosphorylation. We will test this by examining the calcium influx in isolated cardiomyocytes, and in vivo we will explore the interaction between Stim1 and TRPC channels in rodent models of cardiac hypertrophy. PUBLIC HEALTH RELEVANCE: Canonical transient potential receptor (TRPC) channels play a role in the development of heart failure. It is not understood how the channel activity is regulated in the setting of cardiac pathology but stromal interaction molecule 1 (Stim1) may play an important role. We seek to explore this relationship and gain insight to development of heart failure in an effort to identify ways to inhibit the process.