Department of Biofunctional Evaluation, Molecular Pharmacology, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
J Neuroinflammation. 2013 Aug 23;10:105. doi: 10.1186/1742-2094-10-105.
To improve the clinical outcome of patients who suffered ischemic stroke, cerebral ischemia-reperfusion (I/R) injury is one of the major concerns that should be conquered. Inflammatory reactions are considered a major contributor to brain injury following cerebral ischemia, and I/R exacerbates these reactions. The aim of this study was to investigate the possible ameliorative effects of progranulin (PGRN) against I/R injury in mice.
In vivo I/R was induced in four-week-old male ddY mice by 2 h of MCAO (middle cerebral artery occlusion) followed by 22 h of reperfusion. We evaluate expression of PGRN in I/R brain, efficacy of recombinant-PGRN (r-PGRN) treatment and its therapeutic time-window on I/R injury. Two hours after MCAO, 1.0 ng of r-PRGN or PBS was administered via intracerebroventricular. We assess neutrophil infiltration, expression of tumor necrosis factor (TNF)-α, matrix metalloproteinase-9 (MMP-9) and phosphorylation of nuclear factor-κB (NF-κB) by immunofluorescense staining and Western blotting. We also investigate neutrophil chemotaxis and intercellular adhesion molecule-1 (ICAM-1) expression in vitro inflammation models using isolated neutrophils and endothelial cells.
We found that expression of PGRN was decreased in the I/R mouse brain. r-PGRN treatment at 2 h after MCAO resulted in a reduction in the infarct volume and decreased brain swelling; this led to an improvement in neurological scores and to a reduction of mortality rate at 24 h and 7 d after MCAO, respectively. Immunohistochemistry, Western blotting, and gelatin zymography also confirmed that r-PGRN treatment suppressed neutrophil recruitment into the I/R brain, and this led to a reduction of NF-κB and MMP-9 activation. In the in vitro inflammation models, PGRN suppressed both the neutrophil chemotaxis and ICAM-1 expression caused by TNF-α in endothelial cells.
PGRN exerted ameliorative effects against I/R-induced inflammation, and these effects may be due to the inhibition of neutrophil recruitment into the I/R brain.
为了改善缺血性脑卒中患者的临床预后，脑缺血再灌注（I/R）损伤是需要克服的主要关注点之一。炎症反应被认为是脑缺血后脑损伤的主要原因，而 I/R 会加剧这些反应。本研究旨在探讨粒细胞集落刺激因子（PGRN）对小鼠 I/R 损伤的可能改善作用。
通过 2 小时大脑中动脉闭塞（MCAO）后再灌注 22 小时，在 4 周龄雄性 ddY 小鼠中诱导体内 I/R。我们评估了 I/R 脑内 PGRN 的表达、重组-PGRN（r-PGRN）治疗的疗效及其对 I/R 损伤的治疗时间窗。MCAO 后 2 小时，通过侧脑室给予 1.0ng r-PRGN 或 PBS。通过免疫荧光染色和 Western blot 评估中性粒细胞浸润、肿瘤坏死因子（TNF）-α、基质金属蛋白酶-9（MMP-9）和核因子-κB（NF-κB）磷酸化的表达。我们还使用分离的中性粒细胞和内皮细胞在体外炎症模型中研究中性粒细胞趋化性和细胞间黏附分子-1（ICAM-1）的表达。
我们发现 PGRN 的表达在 I/R 小鼠脑内减少。MCAO 后 2 小时给予 r-PGRN 治疗可减少梗死体积和脑肿胀；这导致神经评分在 MCAO 后 24 小时和 7 天分别改善，并降低死亡率。免疫组织化学、Western blot 和明胶酶谱也证实 r-PGRN 治疗抑制了 I/R 脑内中性粒细胞的募集，并降低了 NF-κB 和 MMP-9 的激活。在体外炎症模型中，PGRN 抑制了 TNF-α诱导的内皮细胞中中性粒细胞的趋化性和 ICAM-1 的表达。
PGRN 对 I/R 诱导的炎症具有改善作用，其作用机制可能是抑制中性粒细胞向 I/R 脑内募集。
