Intensive Care Unit, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530000, People's Republic of China.
Department of Physiology, Guangxi Medical University, Nanning, Guangxi 530000, People's Republic of China.
Int Immunopharmacol. 2021 Apr;93:107377. doi: 10.1016/j.intimp.2021.107377. Epub 2021 Jan 29.
Cerebral ischemia-reperfusion injury (CIRI) is the leading cause of poor neurological prognosis after cardiopulmonary resuscitation (CPR). We previously reported that the extracellular signal-regulated kinase (ERK) activation mediates CIRI. Here, we explored the potential ERK/calpain-2 pathway role in CIRI using a rat model of cardiac arrest (CA).
Adult male Sprague-Dawley rats suffered from CA/CPR-induced CIRI, received saline, DMSO, PD98059 (ERK1/2 inhibitor, 0.3 mg/kg), or MDL28170 (calpain inhibitor, 3.0 mg/kg) after spontaneous circulation recovery. The survival rate and the neurological deficit score (NDS) were utilized to assess the brain function. Hematoxylin stain, Nissl staining, and transmission electron microscopy were used to evaluate the neuron injury. The expression levels of p-ERK, ERK, calpain-2, neuroinflammation-related markers (GFAP, Iba1, IL-1β, TNF-α), and necroptosis proteins (TNFR1, RIPK1, RIPK3, p-MLKL, and MLKL) in the brain tissues were determined by western blotting and immunohistochemistry. Fluorescent multiplex immunohistochemistry was used to analyze the p-ERK, calpain-2, and RIPK3 co-expression in neurons, and RIPK3 expression levels in microglia or astrocytes.
At 24 h after CA/CPR, the rats in the saline-treated and DMSO groups presented with injury tissue morphology, low NDS, ERK/calpain-2 pathway activation, and inflammatory cytokine and necroptosis protein over-expression in the brain tissue. After PD98059 and MDL28170 treatment, the brain function was improved, while inflammatory response and necroptosis were suppressed by ERK/calpain-2 pathway inhibition.
Inflammation activation and necroptosis involved in CA/CPR-induced CIRI were regulated by the ERK/calpain-2 signaling pathway. Inhibition of that pathway can reduce neuroinflammation and necroptosis after CIRI in the CA model rats.
脑缺血再灌注损伤（CIRI）是心肺复苏（CPR）后神经预后不良的主要原因。我们之前报道细胞外信号调节激酶（ERK）激活介导 CIRI。在这里，我们使用心脏骤停（CA）大鼠模型探索了 ERK/钙蛋白酶-2 通路在 CIRI 中的潜在作用。
成年雄性 Sprague-Dawley 大鼠发生 CA/CPR 诱导的 CIRI，自主循环恢复后给予生理盐水、DMSO、PD98059（ERK1/2 抑制剂，0.3mg/kg）或 MDL28170（钙蛋白酶抑制剂，3.0mg/kg）。用生存率和神经功能缺损评分（NDS）评估脑功能。苏木精染色、尼氏染色和透射电镜用于评估神经元损伤。用 Western blot 和免疫组化检测脑组织中 p-ERK、ERK、钙蛋白酶-2、神经炎症相关标志物（GFAP、Iba1、IL-1β、TNF-α）和坏死性凋亡蛋白（TNFR1、RIPK1、RIPK3、p-MLKL 和 MLKL）的表达水平。荧光多重免疫组化用于分析神经元中 p-ERK、钙蛋白酶-2 和 RIPK3 的共表达以及小胶质细胞或星形胶质细胞中 RIPK3 的表达水平。
CA/CPR 后 24h，生理盐水组和 DMSO 组大鼠组织形态学损伤，NDS 低，脑组织中 ERK/钙蛋白酶-2 通路激活，炎症细胞因子和坏死性凋亡蛋白表达升高。用 PD98059 和 MDL28170 治疗后，脑功能改善，ERK/钙蛋白酶-2 通路抑制抑制炎症反应和坏死性凋亡。
CA/CPR 诱导的 CIRI 中涉及的炎症激活和坏死性凋亡受 ERK/钙蛋白酶-2 信号通路调节。抑制该通路可减少 CA 模型大鼠 CIRI 后的神经炎症和坏死性凋亡。
