蛋白酶激活受体-2在大鼠体内体外脑缺血模型中的作用研究

Role of protease activated receptor-2 in in vivo and in vitro rat models of ischemic stroke

目的研究蛋白酶激活受体-2(PAR-2)在大鼠体内外脑缺血模型中的作用。方法以PAR-2激活肽(AP)和拮抗剂(Anta)为工具药,使用大脑中动脉阻塞和氧糖剥夺的方法分别建立大鼠和大鼠胚胎脑皮质神经元的缺血模型,观察PAR-2在缺血损伤中的作用及表达变化。用肌动描记器记录PAR-2对正常或来自脑缺血大鼠的大脑中动脉(MCA)血管张力的影响。结果蛋白质印迹法表明PAR-2在缺血侧大脑皮质中表达增多,缺血前给予PAR-2 AP(SLIGRL-NH2)显著改善了体内和体外模型缺血导致的损伤,且能够被PAR-2 Anta(ENMD-1068)所抑制。PAR-2 AP能够使MCA产生一氧化氮依赖性舒张,但是不能被ENMD-1068所抑制。结论 PAR-2有望作为预防性治疗脑缺血疾病的靶点进行研究,ENMD-1068能够抑制SLIGRL-NH2对脑缺血的保护作用。

Objective To determine the effect of protease activated receptor-2（PAR-2） in in vivo and in vitro rat models of ischemic stroke. Methods The effect and expression of PAR-2 were investigated by using PAR-2 activating peptide（AP） and PAR-2 antagonist in rat ischemic stroke models, which were established by middle cerebral artery occlusion and oxygen glucose deprivation. The effects of PAR-2 on vascular tension of middle cerebral artery（MCA） from normal and ischemic rat brain were observed with myograph. Results Western blot showed that the expression of PAR-2 was increased in the ipsilateral brain cortex of rats subject to ischemia, pretreatment of PAR-2 AP（SLIGRL-NH2） protected damages induced by ischemia, and the protection was blocked by PAR-2 antagonist（ENMD-1068）. PAR-2 AP showed nitric oxide-dependent vasodilator action in MCA, which was not blocked by ENMD-1068. Conclusion PAR-2 is identified as a promising target for the development of novel prophylactic treatment of ischemic brain disease, and PAR-2 antagonists can inhibit its protection against ischemia, possibly through vascular-independent way.