CALPAIN AND CASPASE PROTEOLYSIS OF BRAIN SPECTRIN

创伤性脑损伤(TBI)是一个重要的医疗保健问题 美国每年影响200多万人，其中 大约500,000人入院。快速、持续的钙蛋白酶 激活被认为是一种重要的细胞内事件， 颅脑损伤后的神经病理反应。另外，白介素2- 1半胱氨酸蛋白酶的β转换酶(ICE)家族(最近 更名为caspase)也被认为在 颅脑损伤的病理生理学。然而，区域和时间分布的 TBI中的这些蛋白水解酶还没有得到充分的研究。具体的 这项提案的目的是研究钙激活酶和半胱氨酸氨基转移酶介导的 神经细胞骨架蛋白α-血影蛋白的蛋白分解 啮齿动物脑损伤后15分钟至90天的不同脑区， 并将血影蛋白的降解情况与 神经形态的改变。这个项目的一个新特点是 使用同时免疫标记天然α-抗体的抗体 血影蛋白(240kD)，钙蛋白特异性的血影蛋白分解产物 (SBDP)(145kD)和caspase特异性SBDP(120kD)。 斑点。具体目标集中在解决中央 假设脑外伤导致快速和持久的地区性-以及 钙蛋白水解酶和半胱氨酸天冬氨酸氨基转移酶介导的α-半胱氨酸的时间特异性模式 已知易受神经元影响的脑区中的幽灵蛋白分解 侮辱。这项调查将有助于不断壮大的 对致病的病理生理机制的认识 脑外伤后细胞、实质和行为的发病率。

Traumatic brain injury (TBI) is a significant health care issue in the United States affecting more than 2 million persons annually, with approximately 500,000 hospital admissions. Rapid and sustained calpain activation is thought to be an important intracellular event mediating the neuropathological response to TBI. In addition, the interleukin- 1beta-converting enzyme (ICE) family of cysteine proteases (recently renamed caspases) has also been posited as having an important role in the pathophysiology of TBI. However, regional and temporal profiles of these proteases in TBI have not been fully characterized. The Specific Aims of this proposal are to examine calpain-and caspase-mediated proteolysis of the neuronal cytoskeletal protein, alpha-spectrin, in various brain regions from 15 minutes to 90 days following rodent TBI, and to correlate the profile of spectrin degradation to neuromorphological alterations. A novel feature of this project is the employment of an antibody that concurrently immunolabels native alpha- spectrin (240 kD), the calpain-specific spectrin breakdown product (SBDP) (145 kD), and the caspase-specific SBDP (120 kD) on Western blots. The Specific Aims are focused towards addressing the central hypothesis that TBI causes rapid and enduring regionally- and temporally-specific patterns of calpain- and caspase-mediated alpha- spectrin proteolysis in brain regions known to be vulnerable to neuronal insult. This investigation will contribute to the growing body of knowledge regarding the pathophysiological mechanisms contributing to cellular, parenchymal, and behavioral morbidity following TBI.