Hemorrhage Induced Brain Injury

描述（申请人提供）：脑出血（ICH）是一种毁灭性的中风。脑出血引起的脑损伤是由于不断增长的血肿和凝块形成，通过水肿和细胞凋亡损害邻近的大脑。虽然这些是脑出血后发生的不同病理实体，但我们有数据表明它们有一些共同的机制。我们发现脑血肿周围细胞凋亡部分是由谷氨酸兴奋毒性介导的。这使我们发现了非受体酪氨酸激酶pp60-Src (Src)，因为它通过NR2A亚基的直接磷酸化增强了NMDA受体的功能。我们发现大鼠实验性脑出血后Src激酶活性增加了4倍，Src家族激酶（SFK）成员Lyn增加了21倍以上，Src抑制剂减少了脑出血后的细胞凋亡并改善了行为结果。我们假设Src在脑出血介导的细胞凋亡和水肿中起核心作用：脑出血导致凝血酶受体激活Src，激活介导细胞凋亡的NR2A亚基；脑出血激活凝血酶受体，凝血酶受体通过Src激活HIF和MMPs，产生水肿和不良行为结果。这些假设是基于先前的研究表明凝血酶介导脑出血后急性脑水肿，凝血酶通过凝血酶受体激活Src。因此，这些研究将探讨：(a) ICH对Src的影响；(b)凝血酶活化Src；(c) ICH诱导Src磷酸化NMDA受体；(d) HIF-1、HIF-1靶基因和MMPs的Src激活；(e) Src阻断对脑出血大鼠模型细胞存活、水肿和行为结局的影响。目标#1a-d：证明ICH后Src mRNA、Src蛋白、Src磷酸化和Src活性增加。确定凝血酶拮抗剂是否阻断这些脑出血诱导的Src变化，凝血酶和凝血酶受体激动剂是否重现脑出血诱导的Src变化。目标# 2。在Src药物阻断和非药物阻断大鼠脑出血后HIF-1、HIF-1靶基因VEGF、基质金属蛋白酶和NMDA受体亚基磷酸化状态的变化。目标# 3。证明Src的药理学抑制可以改善大鼠脑出血后的细胞存活，减少脑水肿并改善行为结果(a)使用脑出血输注模型和(b)使用缝线诱导的脑出血血管破裂模型。

DESCRIPTION (provided by applicant): Intracerebral hemorrhage (ICH) is a devastating stroke. The damage that occurs in brain from ICH is due to the growing hematoma and clot formation that damages the adjacent brain through edema and apoptosis. Though these are distinct pathologic entities that occur following ICH, we have data that they share some common mechanisms. We found that apoptosis in peri-hematoma brain is mediated in part by glutamate excitotoxicity. This led us to the non-receptor tyrosine kinase, pp60-Src (Src) because it potentiates function of NMDA receptors through direct phosphorylation of the NR2A subunit. We found that Src kinase activity increases 4 fold following experimental ICH in rats, the Src family kinase (SFK) member Lyn increases over 21 fold following ICH, and Src inhibitors decrease apoptosis and improve behavioral outcome following ICH. We hypothesize that Src plays a central role in ICH mediated apoptosis and edema: ICH causes thrombin receptor activation of Src that activates NR2A subunits that mediate apoptosis; and ICH activates thrombin receptors which activates HIF and MMPs via Src to produce edema and poor behavioral outcome. These hypotheses are based upon previous studies showing that thrombin mediates the acute brain edema following ICH, and that thrombin activates Src via the thrombin receptor. Therefore, these studies will examine: (a) the effect of ICH on Src; (b) thrombin activation of Src; (c) ICH induced phosphorylation of NMDA receptors by Src; (d) Src activation of HIF-1, HIF-1 target genes and MMPs; and (e) the effect of Src blockade on cell survival, edema and behavioral outcome using rat models of intracerebral hemorrhage (ICH). The following aims will be addressed: Aims #1a-d: Demonstrate that Src mRNA, Src protein, Src phosphorylation and Src activity increase following ICH. Determine whether thrombin antagonists block these ICH induced changes of Src and whether thrombin and thrombin receptor agonists reproduce the ICH induced changes of Src. Aim #2. Demonstrate changes of HIF-1, of the HIF-1 target gene VEGF, and the Matrix Metalloproteinases and the phosphorylation state of NMDA receptor subunits after ICH in rats with and with out pharmacological blockade of Src. Aim #3. Demonstrate that pharmacological inhibition of Src improves cell survival, decreases brain edema and improves behavioral outcome following ICH in rats (a) using a blood infusion model of ICH and (b) using a suture induced vessel rupture model of ICH.