TRPV1在低频脉冲电刺激中对侧支血管生长的作用及机制研究

Collateral vessel growth plays a important role in the treatment of ischemic disease. In our preliminary experiments we found that the neural regulation is an important factor that contributes to collateral vessels growth by releasing neuropeptide, while electrical stimulation can promote nerve secretes a variety of neuroactive peptides then induce angiogenesis. So, through electrical stimulation promotes the collateral vessel growth has become an important strategy for therapy of ischemic diseases. At the present, it is unclear the exactly mechanism that induce nerve secretes neuroactive peptides. Transient receptor potential vanilloid receptor 1(TRPV1) as a key signaling receptors located in the sensory nerves and blood vessels, which can transfer some important stimula signals to the intracellular instantaneously, then trigger downstream signaling pathways to regulate a variety of neuropeptides or neurotransmitters act on the blood vessel. Accordingly, we speculate TRPV1 maybe the key molecular that caused nerve release neuropeptides in the low frequency pulse electrical stimulation. The project to be adopted by ①To detect the expression of TRPV1 in the collateral vessels after the low frequency pulse electrical stimulation;② To detect the effect and mechanism of TRPV1 mediated low frequency pulse electrical stimulation on the collateral vessel growth through TRPV1 overexpression or blocked;③ To further explore TRPV1 downstream signaling pathways in vitro. This project is expected to provide a new ideas and drug target for the treatment of ischemic diseases.

促进侧支血管生长是治疗缺血性疾病的理想策略。文献和我们的前期工作表明神经肽在内的多种神经介质对侧支血管生长具有重要的促进作用，而电刺激能促进神经分泌多种神经活性肽，进而诱导缺血区域血管生长。因此，通过电刺激促进侧支血管生长有望已成为治疗缺血性疾病的重要途径。目前，究竟是什么机制诱导神经分泌神经活性肽的释放尚不清楚。瞬时受体电位香草酸亚型1 （TRPV1）作为关键的信号感受器分布于感觉神经和血管，可将一些重要的刺激信号瞬时传递到胞内，触发下游信号途径调控多种神经活性肽作用于血管。据此我们设想TRPV1可能是低频脉冲电刺激引起神经释放神经肽等的关键分子。本课题拟通过①低频脉冲电刺激后检测TRPV1在侧支血管的表达变化；②过表达或阻断TRPV1，探讨其在低频脉冲电刺激中对侧支血管生长的作用及其机制；③体外实验进一步探讨TRPV1其下游的信号途径。本项目有望为缺血性疾病的治疗提供新的思路和药物靶点

促侧支血管生长是治疗缺血性疾病的理想策略，电刺激通过激活神经与血管之间的信息传递促进神经分泌多种神经肽诱导缺血区域的血管生长。瞬时受体电位香草酸亚型1 （TRPV1）作为关键的信号感受器可将一些重要的刺激信号瞬时传递到胞内，触发下游信号途径调控多种神经活性肽作用于血管。因此，我们推测TRPV1可能是低频脉冲电刺激引起神经释放神经肽等的关键分子。本项目主要研究了：（1）低频脉冲电刺激对大鼠后肢股动脉结扎诱导侧支血管生长的作用及TRPV1的表达变化；（2）过表达TRPV1后，探讨其在低频脉冲电刺激中对侧支血管生长的作用及其机制；（3）体外培养主动脉血管平滑肌细胞和内皮细胞进一步探讨TRPV1其下游的信号调控途径。取得以下重要结果：（1）低频脉冲电刺激通过增强局部的神经活动促进了侧支血管的生长。可见明显密集呈网状分布的侧支血管，且管腔增大，管壁增殖能力活跃，改善了后肢局部的缺血，表现为骨骼肌肌纤维形态完整；（2）通过过表达TRPV1后，其介导的低频脉冲电刺激促进了侧支血管的生长。表现为侧支小动脉和侧支血管的数目增加，且发育为管腔较大的侧支血管，血管壁各层细胞增殖活跃，血管外膜炎症细胞增多；一氧化氮合酶和外膜成纤维细胞的表达增加。其机制主要是一方面通过促进侧支血管的数目增加，血管壁各层细胞的增殖，血管外膜炎症细胞的浸润，内皮型一氧化氮合酶的表达增加，从而表现为侧支血管外膜炎症的形成，侧支血管壁各层积极的重塑，促进侧支血管的生长；另一方面，血管壁外膜成纤维细胞的激活，使得血管的弹性纤维成分得以充分降解，允许血管壁的向外扩张，从而促进侧支血管的外向性生长；（3）TRPV1介导的Ca2+脉冲，可通过激活钙依赖性转录调节因子和内皮型一氧化氮合酶的表达，从而参与调控侧支血管生长。本课题的研究结果揭示了在复杂的侧支血管生长分子调控网络中，TRPV1可作为核心信号感受器介导低频脉冲电刺激促进侧支血管的生长，从而为临床应用电刺激治疗缺血性疾病提供实验依据和理论指导。