Cell permeant peptidomimetics to prevent delayed vasospasm and neurological deficits after subarachnoid hemorrhage

项目摘要 蛛网膜下腔出血（SAH）由于颅内动脉瘤破裂导致延迟性 血管痉挛导致神经缺血（中风）。总体发病率（严重神经功能缺损， 10-20%的幸存者）和死亡率（50%）都很高，而且该病影响的是相对年轻的成年人 人口预防SAH后迟发性血管痉挛和神经缺血的治疗选择是 目前仅限于血流动力学优化和尼莫地平，其具有边际临床功效。 因此，SAH后迟发性血管痉挛的治疗代表了孤儿未满足的临床需求 具有严重临床后果的人群。 用现有的血管扩张剂治疗蛛网膜下腔出血引起的血管痉挛的尝试经常失败，因为全身性的 低血压（导致脑灌注减少）和难治性脑血管系统 一氧化氮（NO）依赖性信号通路的激活。5 NO信号调节血管 平滑肌（VSM）松弛和脑血流调节。受损的反应 脑血管对血管舒张剂的依赖性，即SAH后血管舒张受损，可能是由于下调 在SAH后NO通路中的信号元件。这项调查的假设是， 用合理设计的下游效应物的细胞渗透性磷酸肽模拟物治疗 NO通路的蛋白质将绕过下调的信号传导元件，恢复血管舒张， 预防SAH后迟发性血管痉挛。这种方法更有针对性和化学计量比 激活或抑制受体或酶的方法。此外，这种方法特别 用于SAH，其中预防全身性低血压和优化脑血管舒张， 至高无上。 cGMP依赖性蛋白底物的一类细胞渗透性磷酸肽类似物 激酶（PKG）和一种调节VSM松弛的肌动蛋白相关蛋白被合理设计 并合成三个候选肽被证明在离体中直接松弛完整的VSM 生物活性测定。序列最短、生物活性最强的肽段（表示为VP 3） 被选为用于测定体内功效的最佳肽。

PROJECT SUMMARY Subarachnoid hemorrhage (SAH) due to rupture of an intracranial aneurysm leads to delayed vasospasm resulting in neuroischemia (stroke). The overall morbidity (profound neurologic deficit in 10-20% of survivors) and mortality (50%) are high, and the disease affects a relatively young adult population. Therapeutic options to prevent delayed vasospasm and neuroischemia after SAH are currently limited to hemodynamic optimization and nimodipine, which have marginal clinical efficacy. Thus, treatment of delayed vasospasm after SAH represents an unmet clinical need in an orphan population with severe clinical consequences. Attempts to treat SAH-induced vasospasm with existing vasodilators often fail because of systemic hypotension (leading to decreased cerebral perfusion) and a cerebral vasculature that is refractory to activation of nitric oxide (NO)-dependent signaling pathways.5 NO signaling modulates vascular smooth muscle (VSM) relaxation and regulation of cerebral blood flow. The impaired response of cerebral vessels to vasodilators, i.e. impaired vasorelaxation after SAH, is likely due to down regulation of the signaling elements in the NO pathway after SAH. The hypothesis of this investigation is that treatment with a rationally designed, cell permeant phosphopeptide mimetic of a downstream effector protein of the NO pathway will bypass downregulated signaling elements, restore vasorelaxation, and prevent delayed vasospasm after SAH. This approach is more targeted and stoichiometric than approaches that activate or inhibit receptors or enzymes. In addition, this approach is particularly useful in SAH where preventing systemic hypotension and optimizing cerebral vasodilation is paramount. A family of cell permeant phosphopeptide analogues of a substrate of cGMP-dependent Protein Kinase (PKG), and an actin-associated protein that modulates VSM relaxation, were rationally designed and synthesized. Three candidate peptides were demonstrated to directly relax intact VSM in ex vivo bioactivity assays. The peptide with the shortest sequence (denoted as VP3) and strongest bioactivity was chosen as the optimal peptide for use to determine in vivo efficacy.