Therapeutic use of bryostatin-1 to extend tPA time window following MCAO

有巨大的临床需求，以改善治疗急性缺血性卒中。目前，重组 组织型纤溶酶原激活剂(TPA)是FDA批准的治疗急性缺血性卒中的唯一药物。 然而，只有不到5%的缺血性中风患者接受tPA治疗，因为继发性中风的风险增加。 脑出血和脑水肿形成。因此，存在着开发有效的新疗法的未得到满足的需求 联合tPA可改善卒中结局，减少继发并发症，延长治疗时间 管理tPA的窗口。Bryostatin-1，一种超强的PKC调节剂，可能为 急性缺血性卒中的治疗。我们研究的长期目标是确定和发展治疗学 这显著改善了tPA的安全性，使更多的缺血性中风患者有资格获得 溶栓治疗。本建议的目的是确定是否可以延长老年大鼠的tPA时间窗。 同时给予Bryostatin-1和tPA。中心假说是通过给药来激活PKCϵ 缺血性脑梗塞急性期Bryostatin-1减轻脑内皮细胞功能障碍； 因此，减少损伤程度，增加窗口，可以安全地完成再灌流。 基本原理是使用两种不同的神经损伤模型(MCAO和轻度创伤性脑损伤)， 给予Bryostatin-1可减少大脑半球肿胀和血脑屏障通透性，提高存活率和 功能恢复。使用我们的临床相关的缺血性中风模型，我们将使用生化， 神经病理学和行为测量，以检验我们的中心假设并实现这一目标 建议，如这两个具体目标所述：(1)确定Bryostatin-1的最佳剂量并验证PKCϵ为 改善脑血管功能的治疗靶点&(2)Bryostatin-1治疗靶点的确定 大脑中动脉阻塞后。特异性目标1检验了Bryostatin-1和tPA在6点联合给药的工作假说 MCAO后h，选择性地激活神经元和脑微血管中的PKCE，这将是低剂量的 Bryostatin-1(10-30微克/平方米)可产生最有效的中风预后。特定目标2测试 大脑中动脉阻塞后6小时联合应用Bryostatin-1和tPA可减少脑肿胀， 选择性激活脑内蛋白激酶Cε减轻出血性转化和改善卒中预后 内皮细胞减轻梗死侧大脑半球血脑屏障功能障碍。因盛行而衰弱 对于缺血性中风的影响，更好的治疗策略的必要性怎么强调都不为过。不幸的是， 能够将有希望的临床前发现转化为有效的药物，在临床上缓解中风后的脑部症状 到目前为止，损害已经失败了。这项提案将确定bryostatin-1与tPA联合应用是否会改善 卒中结局&延长急性缺血性卒中后的tPA时间窗。这项提议的结果是 极大地改善缺血性中风治疗方法的翻译潜力。

There is a tremendous clinical need for improved treatment of acute ischemic stroke. Currently, recombinant tissue plasminogen activator (tPA) is the only FDA approved drug for treatment of acute ischemic stroke. However, less than 5% of people suffering an ischemic stroke receive tPA due to increased risk of secondary cerebral hemorrhage and edema formation. Thus, an unmet need exists to develop novel therapeutics that work in combination with tPA to improve stroke outcome, reduce secondary complications, and extend the time window for administering tPA. Bryostatin-1, an ultrapotent PKC modulator, may provide substantial benefit for treatment of acute ischemic stroke. The long-term goal of our research is to identify and develop therapeutics that markedly improve the safety profile of tPA so that more victims of ischemic stroke are eligible for thrombolysis. The objective of this proposal is to determine if tPA time window can be extended in aged rats co- administered bryostatin-1 with tPA. The central hypothesis is that PKCϵ activation by administration of bryostatin-1 during the acute phase of ischemic cerebral infarction attenuates cerebral endothelium dysfunction; thus, decreasing the degree of injury & increasing the window, in which reperfusion can be safely accomplished. Rationale is that using two separate models of neurological injury (MCAO & mild traumatic brain injury), administration of bryostatin-1 reduced hemispheric swelling & BBB permeability with improved survival & functional recovery. Using our clinically relevant ischemic stroke model, we will use biochemical, neuropathological, and behavioral measures, to test our central hypothesis and accomplish the objective of this proposal, as described in these two specific aims: (1) Identify optimal dose of bryostatin-1 & validate PKCϵ as a therapeutic target & (2) identify therapeutic target of bryostatin-1 that improves cerebrovascular function post- MCAO. Specific aim 1 tests the working hypothesis that co-administration of bryostatin-1 with tPA at 6 h after MCAO will selectively activate PKCe in neurons & cerebral microvessels & it will be lower doses of bryostatin-1 (10-30 mcg/m2) that produce the most efficacious stroke outcome. Specific aim 2 test the working hyothesis that co-administration of bryostatin-1 with tPA at 6 h after MCAO reduces cerebral swelling, mitigates hemorrhagic transformation & improves stroke outcome by selective PKCε activation in cerebral endothelial cells attenuating BBB dysfunction in the infarcted hemisphere. Due to the prevalence & debilitating effects of ischemic stroke, the need for better therapeutic strategies cannot be overstated. Unfortunately, the ability to translate promising preclinical findings into effective drugs that clinically mitigate post-stroke brain damage has, to date, failed. This proposal will determine if co-administration of bryostatin-1 with tPA improves stroke outcome & extends the tPA time window following acute ischemic stroke. Results from this proposal have the translational potential to vastly improve the way ischemic stroke is treated.