NF-κB抑制剂对脑出血大鼠神经损伤的影响

目的:探讨核因子κB(NF-κB)抑制剂吡咯烷二硫代氨基甲酸盐(PDTC)对脑出血(ICH)大鼠神经功能及神经细胞凋亡的调节作用。方法:取SPF级SD大鼠随机分假手术组(sham组)、ICH组、PDTC低浓度组(Plow组)和PDTC高浓度组(P_(high)组),每组6只。采用自体血注入法建立大鼠ICH模型,Plow组和P_(high)组在缺血后2h分别给予100 mg/kg和200 mg/kg的PDTC腹腔注射,sham组和ICH组给予等体积的生理盐水;24 h后,采用改良的Longa分级法进行神经功能评分;TUNEL法测定神经细胞凋亡情况;并检测脑组织中丙二醛(MDA)的含量和超氧化物歧化酶(SOD)的活性。此外,采用Western blot法检测脑组织中p-P65及cleaved caspase-3的蛋白水平。结果:与sham组相比,ICH组大鼠的神经功能评分显著升高(P0.05);应用PDTC后,Plow组和P_(high)组动物的神经功能评分都有所降低,但2组间差异无统计学意义。与sham组相比,ICH组大鼠神经细胞凋亡明显增多(P0.05);应用PDTC后,2组动物神经细胞凋亡数目显著降低,且P_(high)组的细胞凋亡数目显著低于Plow组(P0.05)。与sham组相比,ICH组大鼠脑组织的MDA含量升高,SOD活性降低(P0.05);应用PDTC后,2组动物脑组织中的MDA含量显著降低,而SOD活性升高,且这一趋势在P_(high)组表现更为明显。与sham组相比,ICH组大鼠脑组织中p-P65和cleaved caspase-3的蛋白水平显著增加(P0.05);应用PDTC后,2组动物脑组织中p-P65和cleaved caspase-3的蛋白水平显著降低,且P_(high)组中p-P65和cleaved caspase-3的蛋白水平显著低于Plow组。结论:NF-κB抑制剂PDTC能减轻脑出血后继发性脑损伤,且大剂量作用效果较好;其作用机制可能与降低MDA含量、提高SOD活性进而抑制神经细胞凋亡有关。

Effects of NF-κB inhibitor on nerve injury in rats after intracerebral hemorrhage

AIM: To investigate the regulatory effect of nuclear factor-κB (NF-κB) inhibitor, pyrrolidine dithiocarbamate (PDTC), on nerve function and neural cell apoptosis in rats after intracerebral hemorrhage (ICH). METHODS: SPF Sprague-Dawley rats were randomly divided into 4 groups with 6 rats in each group:sham group, ICH group, PDTC at low concentration (P_low) group and PDTC at high concentration (P_high) group. Autologous blood injection was used to establish ICH model. After 2 h of surgery, the rats in P_low group and P_high group were intraperitoneal injected with PDTC at 100 mg/kg and 200 mg/kg, respectively, while rats in sham group and ICH group were injected with the same volume of saline. The neurological function score was classified with modified Longa grading method. TUNEL assay was used to detected the neural cell apoptosis, and the content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured. Furthermore, the protein levels of p-P65 and cleaved caspase-3 in brain tissues were determined by Western blot. RESULTS: Compared with sham group, the rats in ICH group had higher neurological function score (P<0.05). After treatment with PDTC, the neurological function score was decreased (P<0.05), but no significant difference between P_low group and P_high group was observed. Compared with sham group, the number of apoptotic cells in ICH group was increased (P<0.05). After treatment with PDTC, the neural cell apoptosis was restrained, and the number of apoptotic cells in P_high group was lower than that in P_low group (P<0.05). Compared with sham group, the content of MDA was increased and the activity of SOD was decreased in ICH group (P<0.05). After treatment with PDTC, the content of MDA was decreased while the activity of SOD was increased, and the variation trend was more obvious in P_high group (P<0.05). Compared with sham group, the protein levels of p-P65 and cleaved caspase-3 in ICH group were increased (P<0.05). After treatment with PDTC, the protein levels of p-P65 and cleaved caspase-3 were decreased, and those in P_high group were lower than those in P_low group. CONCLUSION: NF-κB inhibitor PDTC plays a role in the se-condary brain injury after ICH, and the protective effect increases at the higher dose. The mechanism may be related to reducing MDA content and increasing SOD activity, and further inhibiting neural cell apoptosis.