TNF-α、NF-κB在大鼠压疮深部组织损伤中的表达及其对细胞凋亡作用

Expressions of tumor necrosis factor-α and NF-kappa B in skeletal muscles and its effect on apoptosis in deep tissue injury of rats

目的:探讨肿瘤坏死因子-α(TNF-α)、核转录因子-κB(NF-κB)及细胞凋亡在大鼠压疮局部受压组织损伤不同时点表达和作用。方法:建立压疮动物模型,将54只雄性SD大鼠随机分为1个对照组和8个压疮实验组(n=6),实验组施压9个循环(3 c/d,3 d),分别观察1 d、3 d、5 d、7 d,光镜下观察局部骨骼肌组织病理变化;Western blot检测各组骨骼肌组织TNF-α蛋白表达变化;免疫组化检测NF-kB和半胱氨酸天冬氨酸蛋白酶-3(caspase-3)的蛋白表达并分析其相关性;Hochest染色骨骼肌细胞凋亡细胞数。结果:与对照组相比,各实验组骨骼肌组织结构紊乱、组织间隙增宽、细胞肿胀、炎症细胞增多,恢复期组织病理改变逐渐减轻,炎症细胞减少;各实验组骨骼肌组织中TNF-α、NF-κB、caspase-3的水平均显著升高(P<0.05),1 d达到高峰,3 d逐渐下降,但7 d NF-κB、caspase-3的水平仍显著高于对照组(P<0.01);细胞凋亡数呈先升高后下降的趋势;各实验组的TNF-α表达与NF-κB、caspase-3的表达呈正相关(P<0.05),NF-κB表达与caspase-3的表达呈显著正相关(P<0.01)。结论:压疮深部组织损伤中,局部受压组织中炎症与凋亡同时存在,NF-κB不仅参与了炎症发生的过程,而且在启动细胞凋亡方面具有重要作用。

Objective： To evaluate the changes of tumor necrosis factor-α（TNF-α） and nuclear factor-κB（NF-κB） expression in muscle of pressure ulcer rats and explore the relationship with apoptosis. Methods： Fifty-four male SD rats were randomly divided into nine goups（ n = 6）, the experiment groups were pressed 9 circles（3 circles/day, 3 days）, then observed on the lst, 3rd, hematoxylin and eosin staining under the microscope; the expression of TNF-α was detected by Western blot; the expressions of NF-κB and caspase-3 were determined by immunohistochemistry, and evaluated the relationship of TNF-α with NF-κB and caspase-3; the number of apoptotic cells in compressed muscle tissue was detected by Hoechst 33258 staining under the fluorescence microscope. Results： Compared with the control group, histology examination showed that the tissue structure in experiment groups was in disorder, inter-space was wider, cell edema and the number of inflammatory cells were increased, the tissue was arranged in order and inflammatory cell recnfitment was gradually attenuated. The expressions of TNF-α, NF-κB and caspase-3 were higher in the experiment groups than those in the control group（ P 〈 0.05）, reached their peak on the first day, gradually decreased on the 3rd day, but still had a significantly higher level than that in the control group （ P 〈 0.01） on the 7th day; rllae number of apoptotic cells of experiment groups had a downward trend after the first rise under the fluorescence microscope; the expressions of TNF-α and NF-κB caspase-3 were found to have positive correlationship（ P 〈 0.05）, the expressions of NF-κB and caspase-3 were found to have positive correlationship（ P 〈 0.01 ）. Conclusion： Apoptosis is closely correlated with inflammation in deep tissue injury of pressure deer, NF-κB plays a role not only in the formation of inflammation, but also triggering apoptosis, which may induce the pathological change and clinical progress of pressure ulcer.