The roles and the kinetics of gp91 phox after traumatic brain injury in mice

gp91 phox在小鼠脑外伤后的作用和动力学

基本信息

批准号：
20592128
负责人：
DOHI Kenji
金额：
$ 2.91万
依托单位：
Showa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

项目摘要

INTRODUCTION :We hypothesized that gp91phox (NOX2), a subunit of NADPH oxidase, generates superoxide anion (O2-) and has a major causative role in traumatic brain injury (TBI). To evaluate the functional role of gp91phox and reactive oxygen species (ROS) on TBI, we carried out controlled cortical impact in gp91phox knockout mice (gp91phox-/-). We also used a microglial cell line to determine the activated cell phenotype that contributes to gp91phox generation.METHODS :Unilateral TBI was induced in gp91phox-/- and wild-type (Wt) mice (C57/B6J) (25-30 g). The expression and roles of gp91phox after TBI were investigated using immunoblotting and staining techniques. Levels of O2- and peroxynitrite were determined in situ in the mouse brain. The activated phenotype in microglia that expressed gp91phox was determined in a microglial cell line, BV-2, in the presence of IFNgamma or IL-4.RESULTS :Gp91phox expression increased mainly in amoeboid-shaped microglial cells of the ipsilateral hemisphere of Wt mice after TBI. The contusion area, number of TUNEL-positive cells, and amount of O2- and peroxynitrite metabolites produced were less in gp91phox-/- mice than in Wt. In the presence of IFNgamma, BV-2 cells had increased inducible nitric oxide synthase and nitric oxide levels, consistent with a classical activated phenotype, and drastically increased expression of gp91phox.CONCLUSIONS :Classical activated microglia promote ROS formation through gp91phox and have an important role in brain damage following TBI. Modulating gp91phox and gp91phox -derived ROS may provide a new therapeutic strategy in combating post-traumatic brain injury.

简介：我们假设 gp91phox (NOX2) 是 NADPH 氧化酶的一个亚基，可产生超氧阴离子 (O2-)，并在创伤性脑损伤 (TBI) 中起主要致病作用。为了评估 gp91phox 和活性氧 (ROS) 对 TBI 的功能作用，我们对 gp91phox 敲除小鼠 (gp91phox-/-) 进行了受控的皮质影响。我们还使用小胶质细胞系来确定有助于 gp91phox 生成的激活细胞表型。方法：在 gp91phox-/- 和野生型 (Wt) 小鼠 (C57/B6J) (25-30 g) 中诱导单侧 TBI。使用免疫印迹和染色技术研究了 TBI 后 gp91phox 的表达和作用。在小鼠大脑中原位测定 O2- 和过氧亚硝酸盐的水平。在存在 IFNgamma 或 IL-4 的情况下，在小胶质细胞系 BV-2 中测定了表达 gp91phox 的小胶质细胞中的激活表型。结果：Gp91phox 表达主要在 Wt 小鼠同侧半球的变形虫形小胶质细胞中增加。创伤性脑损伤。 gp91phox-/- 小鼠的挫伤面积、TUNEL 阳性细胞的数量以及产生的 O2- 和过氧亚硝酸盐代谢物的量均少于 Wt 小鼠。在 IFNgamma 存在的情况下，BV-2 细胞的诱导型一氧化氮合酶和一氧化氮水平增加，与经典激活表型一致，并且 gp91phox 表达显着增加。结论：经典激活小胶质细胞通过 gp91phox 促进 ROS 形成，并具有重要作用TBI 后的脑损伤。调节 gp91phox 和 gp91phox 衍生的 ROS 可能为对抗创伤后脑损伤提供新的治疗策略。