COMPLEMENT-MEDIATED NEURONAL INJURY IN STROKE

描述（来自申请人的摘要）：缺血性中风是脑缺血的主要原因。 死亡和残疾，治疗选择非常有限。的 治疗的困境所造成的对立的目标，实现快速 再灌注和预防脑出血（ICH），使我们 考虑到靶向炎症范例的效用， 级联，用于缺血性卒中的抑制。研究是由 补体激活直接导致脑损伤假说 可能间接降低tPA的疗效， 补体的纤溶酶依赖性活化。模型中的初步数据 使用基因缺陷小鼠的中风研究指出， 通过P-和E-选择素和ICAM-1糖蛋白募集白细胞 粘附受体最近，我们发现缺血会触发神经元 以表达早期补体成分（C1 q，从而潜在地标记 自身用于裂解或受体介导的免疫清除。C1 q表达， 缺血性损伤的神经元结合可溶性截短形式的细胞外 补体受体1（sCR 1）的结构域，可抑制局部补体 激活并在中风中提供部分脑保护。当这个 补体抑制蛋白通过sLex-糖基化共价修饰， 此外，抑制选择素介导的事件，观察到显着的收益， 减少白细胞和血小板募集，导致安全， 即使延迟治疗也能提供持久保护。在我们的新的初步数据 再灌注中风的灵长类动物（狒狒）模型显示类似的上调， 脑缺血再灌注后脑微血管选择素和神经元C1 q的表达 区在狒狒中风的双盲安慰剂对照试验中， 完成后，人源化抗P-/E-选择素抗体显示出中度的 脑保护功效综合这些数据，我们可以推测， 选择素和补体介导的免疫炎症机制是 与中风病理生理相关，同时抑制 这两种机制都可以提供新的和有用的治疗靶点。此外，委员会认为， 鉴于纤溶酶可以激活补体，而抗补体方法可以 特别适用于中风，以提高治疗效果， rtPA的窗口。这些数据直接导致具体目标，即：（1） 使用C1 qa-/-小鼠证明C1 q表达在鼠中风中的作用， 确定c1 q表达的作用是否是通过激活 补体级联和/或通过跨膜和胞质溶质的局部结合 受体导致增强的氧化应激和吞噬作用;（2）确定 tPA溶栓是否激活补体，从而减少它的 保护脑中风的能力;（3）确定 C1 q表达在灵长类中风中的病理生理作用 补体阻断（与sCR 1）策略以及联合抗粘附 受体，抗补体策略（sCR 1/SLex）。

DESCRIPTION (From Applicant's Abstract): Ischemic stroke is a leading cause of death and disability, for which treatment options are very limited. The therapeutic dilemma created by the opposing goals of achieving rapid reperfusion and preventing intracerebral hemorrhage (ICH), has led us to consider the utility of targeting an inflammatory paradigm, the complement cascade, for inhibition in ischemic stroke. Studies are driven by the hypothesis that complement activation contributes directly to cerebral injury in stroke and may indirectly reduce the efficacy of tPA due to plasmin-dependent activation of complement. Preliminary data in a model of stroke using gene deficient mice have pointed to the critical deleterious role for leukocyte recruitment via the P- and E-selectin and ICAM-1 glycoprotein adhesion receptors. More recently, we have shown that ischemia triggers neurons to express an early complement component (C1q, thereby potentially flagging themselves for lysis or receptor mediated immune clearance. C1q-expressing, ischemically injured neurons bind a soluble truncated form of the extracellular domain of the complement receptor 1 (sCR1), which inhibits local complement activation and confers partial cerebral protection in stroke. When this complement-inhibitory protein is covalently modified by sLex- glycosylation to additionally inhibit selectin-mediated events, striking gains are observed in terms of reducing leukocyte and platelet recruitment, leading to a safe, durable protection even with delayed treatment. Preliminary data in our new primate (baboon) model of reperfused stroke demonstrate similar upregulation of cerebral microvascular selectin and neuronal C1q expression in the ischemic zone. In a double-blind placebo-controlled trial of baboon stroke we have just completed, a humanized anti-P-/E-selectin antibody demonstrated moderate cerebral protective efficacy. Together, these data lead us to hypothesize that selectin- and complement-mediated immune-inflammatory mechanisms are pathophysiologically relevant in stroke, and that simultaneous inhibition of both mechanisms may provide a novel and useful therapeutic target. Furthermore, given that plasmin may activate complement, and anti-complement approach might be especially useful in stroke to increase the efficacy of and therapeutic window for rtPA. These data lead directly to the Specific Aims, which are: (1) demonstrate the role of C1q expression in murine stroke using C1qa -/- mice and determine whether the effect of c1q expression is injurious via activation of the complement cascade and/or via local binding of transmembrane and cytosolic receptors leading to enhanced oxidative stress and phagocytosis; (2) determine whether thrombolysis with tPA activates complement, thereby diminishing it's capacity to protect the brain in stroke; and (3) determine the pathophysiological contribution of C1q expression in primate stroke using complement blockade (with sCR1) strategy as well as a combined anti-adhesion receptor, anti-complement strategy (sCR1/SLex).