Immunomodulatory effects of Inter-alpha Inhibitors in attenuating Ischemic Stroke

 描述(申请人提供)：目前批准用于人类的中风疗法是有限的。临床上可用的一种药物是溶栓剂组织型纤溶酶原激活剂(t-PA)，只有在症状出现后4.5小时内使用才会出现，并伴随着极大的颅内出血风险。因此，只有一小部分患者接受了这种疗法。新出现的数据表明，缺血后氧化应激和炎症介质促进了脑损伤和缺血性病变的扩大。由于炎症反应延迟(几小时到几天)，它是一个有吸引力的治疗干预目标。α-抑制蛋白(IAIP)是在血液中循环的复杂蛋白(250 kDa和125 kDa)，由多个亚基组成。在日本和中国，已经从尿液中分离出一个亚单位(轻链，也被称为bikunin)，并被临床用于治疗急性胰腺炎和其他炎症性疾病。然而，这个亚基的半衰期很短(3-10分钟)，需要大量的蛋白质和持续的静脉输注。我们建议评估IAIP的血源性复合体形式(半衰期为8-12小时)。作为一种潜在的神经保护剂，因为这种形式更适合临床使用。由于复合体中其他亚单位(重链)的存在，该配方还可能具有附加保护作用。在我们实验室的初步工作中，使用外源性血液来源的人IAIP剂量为30 mg/kg(该剂量已显示出对脓毒症的保护作用)发现，IAIP对年轻成年小鼠实验性中风后具有显著的神经保护作用。即使在脑缺血发作后6小时给予IAIP，脑梗塞体积也会缩小，功能结果也会改善。我们现在已经证明，这种保护剂可以持续30天，而且这种制剂对老年动物也有保护作用。基于这些非常有希望的初步结果，我们建议系统地确定最佳剂量，检查药代动力学，并直接评估脑和血清中IAIP(Aim1)的水平。我们将确定在慢性(1个月和3个月)终点是否维持了老年小鼠的神经保护和行为改善(目标2)，并确定是否在中风的栓子模型中也看到了保护(目标3)。这些研究是为响应NINDS“翻译研究中的探索性/发展性项目”(PAR13-023)项目而设计的。

 DESCRIPTION (provided by applicant): Current stroke therapies approved for human use are limited. The one drug clinically available, the thrombolytic agent tissue plasminogen activator (t-PA), is indicated only if administered within 4.5 hours of symptom onset and carries with it a significant risk of intracranial hemorrhage. Consequently, only a small percentage of patients receive this therapy. Emerging data suggest that post-ischemic oxidative stress and inflammatory mediators contribute to brain injury and expansion of the ischemic lesion. As the inflammatory response is delayed (hours to days), it is an attractive target for therapeutic intervention. Inter-alpha inhibitor proteins (IAIP) are complex proteins (250 and 125 kDa) circulating in blood, which consist of multiple subunits. In Japan and China, one subunit (the light chain, also known as bikunin) has been isolated from urine and is used clinically to treat acute pancreatitis and other inflammatory diseases. However, the half-life of this subunit is very short (3-10 min), requiring large amounts of protein and constant intravenous infusion. We propose to evaluate the blood-derived complexes form of IAIP (half-life of 8-12 hrs.) as a potential neuroprotective agent, as this form is more feasible for clinical use. This formulation may also have additive protective effects due to the presence of other subunits (the heavy chain) in the complex. Preliminary work in our lab using exogenously administered blood-derived human IAIP at a dose of 30mg/kg (a dose that has shown protection in sepsis) found that IAIP is strikingly neuroprotective after experimental stroke in young adult mice. Infarct volumes are reduced and functional outcomes improved even when IAIP was given six hours after ischemic onset. We have now shown that the protection is sustained at 30 days, and that this agent is also protective in aged animals. Based on these very promising initial results we propose to systematically determine the optimal dose, examine the pharmacokinetics, and directly evaluate brain and serum levels of IAIP (Aim1). We will determine if neuroprotection and behavioral improvements are sustained at chronic (1 and 3 month) endpoints in aged mice of both sexes (Aim 2) and determine if protection is also seen in an embolic model of stroke (Aim 3). These studies were designed in response to the NINDS "Exploratory/Developmental Projects in Translational Research" (PAR13-023) program.