目的 基于miR-223-3p探讨淫羊藿苷治疗大鼠颅脑外伤神经损伤的作用机制。方法 随机选取70只大鼠，建立局部脑挫裂伤模型，将建模成功的60只大鼠随机分为模型组、淫羊藿苷（30 mg/kg）组、淫羊藿苷（30 mg/kg）＋阴性对照组和淫羊藿苷（30 mg/kg）＋miR-223-3p antagomir组，每组15只，另取15只大鼠作为对照组。给予相应药物进行干预，末次干预2 h后，对各组大鼠进行改良神经功能缺损评分（modified neurological severity scores，mNSS）；测定各组大鼠脑组织含水量；采用ELISA法检测各组大鼠脑组织白细胞介素-18（interleukin-18，IL-18）和IL-1β水平；采用苏木素-伊红（HE）染色法观察各组大鼠脑组织病理变化；采用TUNEL染色法观察各组大鼠脑组织神经元凋亡情况；采用qRT-PCR法检测各组大鼠脑组织miR-223-3p和核苷酸结合寡聚化结构域样受体蛋白3（nucleotide-binding oligomerization domain-like receptor protein 3，NLRP3）mRNA表达情况；采用Western blotting法检测各组大鼠脑组织NLRP3、半胱氨酸蛋白酶-1（Caspase-1）、B淋巴细胞瘤2（B-cell lymphoma 2，Bcl-2）和Bcl-2相关X蛋白（Bcl-2 associated X protein，Bax）蛋白表达情况；采用双荧光素酶报告基因系统检测miR-223-3p对NLRP3的靶向性。结果 与模型组比较，淫羊藿苷组大鼠mNSS显著降低（P<0.05），脑组织含水量显著降低（P<0.05），脑组织IL-18和IL-1β水平显著降低（P<0.05）；脑组织损伤面积和红细胞数减少；神经元细胞凋亡指数显著降低（P<0.05）；脑组织miR-223-3p mRNA表达水平升高，NLRP3 mRNA表达水平显著降低（P<0.05）；脑组织NLRP3、Caspase-1和Bax蛋白表达水平降低，Bcl-2蛋白表达水平显著升高（P<0.05）。与淫羊藿苷组比较，淫羊藿苷＋miR-223-3p antagomir可显著逆转上述指标（P<0.05）。双荧光素酶报告结果显示，miR-223-3p可靶向调控NLRP3。结论 淫羊藿苷对大鼠颅脑外伤神经损伤具有改善作用，其作用机制可能与调控miR-223-3p从而靶向抑制NLRP3表达、抑制炎性反应、减少神经元细胞凋亡有关。

Objective To explore the mechanism of icariin on nerve injury in rats with craniocerebral trauma based on miR-223-3p. Methods Seventy rats were randomly selected to establish a local brain contusion model. Sixty rats were successfully modeled and randomly divided into model group, icariin (30 mg/kg) group, icariin (30 mg/kg) + NC group and icariin (30 mg/kg) + miR-223-3p antagomir group, with fifteen rats in each group, and 15 rats were selected as control group. The corresponding drugs were given for intervention. 2 h after last intervention, rats in each group were subjected to record modified neurological severity scores (mNSS); Water content of brain tissue of rats in each group was measured; ELISA was used to detect interleukin-18 (IL-18) and IL-1β levels in brain tissue of rats in each group; Hematoxylin-eosin (HE) staining method was used to observe the pathological changes of brain tissue of rats in each group; TUNEL staining method was used to observe neuron apoptosis in brain tissue of rats in each group; qRT-PCR was used to detect miR-223-3p and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) mRNA expressions in brain tissue of rats in each group; Western blotting was used to detect NLRP3, Caspase-1, B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X protein (Bax) protein expressions in brain tissue of rats in each group; Dual luciferase reporter gene system was used to detect the targeting of miR-223-3p to NLRP3. Results Compared with model group, mNSS of rats in icariin group was significantly reduced (P < 0.05), brain tissue water content was reduced (P < 0.05), IL-18 and IL-1β levels in brain tissue were reduced (P < 0.05); Brain tissue damage area and red blood cell count were decreased; Neuronal cell apoptosis index was decreased (P < 0.05); miR-223-3p mRNA expression in brain tissue was increased, and NLRP3 mRNA expression was decreased (P < 0.05); NLRP3, Caspase-1 and Bax protein expressions in brain tissue were reduced, and Bcl-2 protein expression were increased (P < 0.05). Compared with icariin group, icariin + miR-223-3p antagomir group significantly reversed the above indicators (P < 0.05). The result of dual luciferase report showed that miR-223-3p could target NLRP3. Conclusion Icariin can improve nerve injury in rats with craniocerebral trauma, its mechanism may be related to the inhibition of NLRP3 expression byregulating miR-223-3p, inhibition of inflammatory response and reduction of neuronal cell apoptosis.

R285.5

国家自然科学基金资助项目（81971171）