Hemorrhage Induced Brain Injury

脑出血(ICH)是一种毁灭性的中风。脑出血对大脑的损害是由于 不断增长的血肿和凝块形成，通过浮肿和细胞凋亡损害邻近的大脑。 虽然这些都是脑出血后的不同病理实体，但我们有数据表明，它们有一些共同之处 共同的机制。我们发现血肿周围脑组织的细胞凋亡部分是由谷氨酸介导的。 兴奋性毒性。这让我们找到了非受体酪氨酸激酶pp60-Src(Src)，因为它增强了功能 通过NR2A亚单位的直接磷酸化而影响NMDA受体。我们发现，Src激酶的活性 大鼠实验性脑出血后增加4倍，Src家族激酶(SFK)成员Lyn增加超过 21倍于脑出血后，和Src抑制剂减少细胞凋亡和改善脑出血后的行为结局。 我们假设Src在ICH介导的细胞凋亡和水肿中起中心作用：ICH导致凝血酶 Src受体激活，激活NR2A亚单位，介导细胞凋亡；脑出血激活凝血酶 受体通过Src激活HIF和MMPs，导致水肿和不良行为结局。这些 假说是基于以前的研究表明凝血酶介导急性脑水肿。 脑出血后，凝血酶通过凝血酶受体激活Src。因此，这些研究将 检查：(A)脑出血对Src的影响；(B)凝血酶激活Src；(C)脑出血诱导的磷酸化 (D)Src对HIF-1、HIF-1靶基因和MMPs的激活；(E)Src的作用 阻断脑出血大鼠模型对细胞存活、水肿和行为结局的影响 (ICH)。将解决以下目标：目标#1a-d：证明Src mRNA、Src蛋白、Src 脑出血后，磷酸化和Src活性增加。确定凝血酶拮抗剂是否阻断 这些脑出血引起的Src的变化以及凝血酶和凝血酶受体激动剂是否复制脑出血 诱导的Src的变化。目的#2.观察HIF-1靶基因血管内皮细胞生长因子(VEGF)中HIF-1的变化，探讨HIF-1的作用机制。 大鼠脑出血后基质金属蛋白酶与NMDA受体亚单位的磷酸化状态 且不存在药物阻滞剂。目的#3.证明Src的药理抑制作用 改善大鼠脑出血后细胞存活、减轻脑水肿和改善行为结局(A) 使用脑出血的输血模型和(B)使用缝合诱导的脑出血血管破裂模型。

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.