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

急性缺血性中风的治疗方法有着巨大的临床需求。目前，重组 组织纤溶酶原激活剂（tPA）是FDA批准的唯一用于治疗急性缺血性中风的药物。 然而，只有不到5%的缺血性卒中患者由于继发性脑卒中风险增加而接受tPA治疗。 脑出血和水肿形成。因此，存在开发新的治疗剂的未满足的需求， 联合tPA改善卒中结局，减少继发性并发症，延长 给药tPA的窗口。苔藓抑素-1，一种超强效的PKC调节剂，可能为 急性缺血性中风的治疗。我们研究的长期目标是确定和开发治疗方法 这显著提高了tPA的安全性，使更多的缺血性中风患者有资格接受tPA治疗。 血栓溶解本提案的目的是确定tPA时间窗是否可以在老年大鼠中延长， 给药苔藓抑素-1和tPA。中心假设是，PKC通过给予 苔藓抑素-1在缺血性脑梗死急性期减轻脑内皮功能障碍; 从而降低损伤程度，增加安全再灌注的时间窗。 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）， 施用苔藓抑素-1减少了半球肿胀和BBB通透性， 功能恢复使用我们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）确定苔藓抑素-1的最佳剂量并验证PKC抑制剂 治疗靶点&（2）确定苔藓抑素-1改善脑血管功能的治疗靶点 后MCAO。具体目标1检验了工作假设，即在6 ℃下共同施用苔藓抑素-1与tPA， MCAO后2 h将选择性激活神经元和脑微血管中的PKCe， 苔藓抑素-1（10-30 mcg/m2）产生最有效的中风结果。具体目标2测试 在MCAO后6小时共同施用苔藓抑素-1和tPA减少脑肿胀的工作假设， 通过选择性激活脑内PKCε减轻出血性转化并改善卒中结局 内皮细胞减弱梗死半球中的BBB功能障碍。由于流行和衰弱 由于缺血性中风的影响，对更好的治疗策略的需求不能被夸大。可惜 能够将有希望的临床前发现转化为临床缓解卒中后大脑的有效药物 到目前为止，破坏已经失败。该提案将确定苔藓抑素-1与tPA联合给药是否改善了 卒中结局&延长急性缺血性卒中后tPA时间窗。该提案的结果是 巨大改善缺血性中风治疗方式的转化潜力。

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.