TNF-α刺激不同潮气量通气小鼠对细胞因子表达的影响

The Effect of TNF-α on the Cytokines Expression in mice with Different Tidal Volume Ventilation

目的:探讨TNF-α刺激不同VT通气小鼠对细胞因子表达影响。方法:36只SPF级雄性BALB/c小鼠,随机分三组:A组:自主呼吸4 h,n=12;S组:VT=6 m L/kg,机械通气4 h,n=12;L组:VT=20 m L/kg,机械通气4 h,n=12。各组再分2亚组:对照组(C组,尾静脉注射生理盐水,n=6)、实验组(T组,以20μg/kg尾静脉注射TNF-α,n=6)。观察肺组织形态学及细胞超微结构变化;检测血清和BALF炎性因子的表达、NF-κBm RNA及蛋白的表达。结果:L组肺呈水肿、部分实变,炎性细胞积聚,巨噬细胞膜、核染色质、板层小体、微绒毛等损伤性改变,且T组较C组明显;与A组及S组比较,L组血清、BALF中TNF-α,IL-1β,IL-6,IL-10表达及NF-κB m RNA及蛋白表达均明显升高,有统计学意义(P<0.05)。T组与C组比较,TNF-α,IL-1β,IL-6,IL-10表达及NF-κb m RNA及蛋白表达均明显升高,有统计学意义(P<0.05),且NF-κB表达与TNF-α、IL-1β,IL-6呈正相关。结论:TNF-α是VAP发病的关键因子,可能为临床预防VAP提供新方法。

Objective To investigate the effect of tumor necrosis factor-α （TNF-α） on cytokines expression in mice with different tidal volume （VT）. Methods Thirty six SPF male BALB/c mice were randomly divided into three groups： A group （spontaneously breathed 4 h）, S and L group （mechanically ventilated 4 h, VT = 6 mL/kg and VT = 20 mL/kg）. The three groups were then randomly divided into two subgroups （C and T group, n = 6）. Mice in C group were injected with NS, while that of T groups were injected with TNF-α at 20 μg/kg from tail intravenous. Morphological manifestation was observed by hematoxylin and eosin staining. Ultrastructure of macrophages were examined by transmission electron microscopy. The expression of TNF-α, interleukin （IL）-1β, IL-6, IL-10 in serum and BALF were measured by ELISA. The expression of NF-κB mRNA and protein were detected by RT-PCR and WB, respectively. Results Compared with A and S group, following could be observed under light microscope in L group： the pulmonary interstitial edema, consolidation of part of the lung tissue, alveolar space fusion and a number of inflammatory cells infihration. The expression of TNF-α, IL-1β, IL-6, IL-10 in serum and BALF, the expression of NF- κB mRNA and protein in macrophages of L group were significantly higher than those of A and S group （both P 〈 0.05）. The expression of these cytokines and NF-κB mRNA and protein were increased in T group （P 〈 0.05）. The expression NF-κB is positively correlated with the expression of TNF-α, IL-1β and IL-6. Conclusion TNF-α is a key factor in inflammation of ventilation induced lung injury, which may provide a new method for prevention of VILI in clinical practice.