他克莫司通过活化T细胞核因子c1促进大鼠创伤性脑损伤后神经功能修复的作用

Tacrolimus promotes neurological outcomes after traumatic brain injury in rats through activation of nuclear factor of activated T cell c1

目的探讨他克莫司通过调节活化T细胞核因子（NFAT）cl促进大鼠创伤性脑损伤（TBI）后神经功能修复的作用。方法选择90只SD大鼠，利用液压打击制作大鼠中度TBI模型。按随机数字表分为假手术组、TBI组和他克莫司治疗组。假手术组只接受开颅手术并连续7d腹腔注射等体积0．9％等渗盐水；TBI组连续7d腹腔注射等体积0．9％等渗盐水；他克莫司组连续7d腹腔注射等体积他克莫司（1mg／kg）。利用改良神经功能评分（mNSS）和水通道蛋白（AQP4）mRNA表达评价神经功能损伤程度。TBI后1，7，14d采用酶联免疫吸附实验（ELISA）和RT—PCR检测白细胞介素一2（IL一2）、，y干扰素（IFN一^y）蛋白和mRNA表达，RT—PCR、Westernblot和免疫荧光检测钙调神经磷酸酶（CaN）和NFATcl信号通路活化情况。结果mNSS结果显示，他克莫司治疗组在TBI后1，7，14d得分显著低于TBI组（P〈0．05），但仍高于假手术组。RT—PCR结果显示，TBI后1d他克莫司治疗组AQP4mRNA的表达水平显著降低，但仍高于假手术组。ELISA和RT—PCR结果显示，与TBI组比较，他克莫司治疗组在各时相点IL-2和IFN-γ的mRNA表达水平和蛋白含量均降低，尤以1d降低最为显著（P〈0．05）。RT—PCR和Westernblot结果显示，与TBI组比较，他克莫司治疗组TBI后CaN的mRNA和蛋白表达降低（P〈0．05）。免疫荧光检测结果显示，与假手术组比较，TBI后7d胞浆中NFATcl显著入核；与TBI组比较，他克莫司治疗组TBI胞浆中NFATc-1的蛋白入核受到抑制（P〈0．05）。结论他克莫司通过调节NFATcl来抑制炎症反应，减轻中度TBI后脑水肿程度，促进神经功能修复。

Objective To observe the effect of tacrolimus on neurological outcomes after traumatic brain injury （TBI） in rats through the activation of nuclear factor of activated T cell cl （NFATcl）. Methods The fluid percussion injury model of TBI was used in the study. Ninety SD rats were divided into Sham group, TBI group and Tacrolimus group according to the random number table. Sham group received intraperitoneal saline solution injection for 7 days after sham injury. TBI group and Tacrolimus group were respectively administered intraperitoneal saline solution injection or tacrolimus （ 1 mg/kg） for 7 days after the induction of FPI. Severity of neurological dysfunction effects was evaluated using the modified neurological severity score （mNSS） and level of aquaporin 4 （AQP4） mRNA. Levels of interleukiu-2 （IL-2） and interferon-~/ （IFN-~） protein and mRNA were detected by RT-PCR and ELISA method. Activation of CaN/NFATcl signal was checked by RT-PCR, Western blot and immunofluorescence staining. Results mNSS in Tacrolimus group was significantly reduced compared to TBI group at days 1, 7 and 14 postinjury （P 〈0.05）, but the score remained higher than that in Sham group. Expression of AQP4 mRNA in Tacrolimus group was significantly reduced compared to TB! group at day 1 postinjury, but the level remained higher than that in sham group. Expressions of IL-2 and IFN-~ mRNA and protein in tacrolimus group were reduced compared to TBI group, especially at day 1 postinjury （P 〈 0. 05 ）. Expressions of CaN mRNA and protein in tacrolimus group were significantly down-regulated compared to TBI group （P 〈 0.05）. NFATcl nuclear entry was obvious at day 7 postinjury, but tacrolimus displayed an inhibitory effect against the nuclear entry of NFATcl （P 〈 0.05）. Conclusion Tacrolimus relieves inflammatory responses, attenuates brain edema after moderate TBI and facilitates neurological outcomes by regnlating the NFATcl.