Toll样受体4在小儿支原体肺炎中的作用及对IL-6、IL-8、TNF-α表达的影响

Role of Toll-like Receptor 4 in Children with Mycoplasma Pneumonia and the Influence on Interleukin-6,Interleukin-8,Tumor Necrosis Factor-α Expression

目的探讨Toll样受体4(TLR4)在小儿急性期支原体肺炎中的作用及可能机制。方法选择2011年1月至2014年8月于天津市北辰区妇女儿童保健中心收治的急性期支原体肺炎患儿50例作为急性期组,选择同时间于天津市北辰区妇女儿童保健中心和天津市公安医院收治的支原体肺炎稳定期患儿50例作为稳定期组,50例健康儿童为健康对照组。检测受试者阻断前及TLR4、TLR2阻断后白细胞介素(IL)6、IL-8、肿瘤坏死因子(TNF)α的表达情况。结果急性期组患儿外周血单核细胞中,TLR4 mRNA水平显著高于稳定期组和健康对照组(0.034±0.010比0.016±0.008,0.014±0.006,P<0.01);急性期组阻断前血清IL-6、IL-8、TNF-α水平显著高于健康对照组[(8 352±276)ng/L比(6 027±258)ng/L,(1 910±100)ng/L比(510±29)ng/L,(355±19)ng/L比(492±77)ng/L,P<0.01];TLR4阻断后IL-6、IL-8、TNF-α水平[(7 510±220)ng/L,(980±90)ng/L,(391±23)ng/L]显著低于阻断前(P<0.01);TLR2阻断后外周血单核细胞上清中IL-6、IL-8、TNF-α水平[(8 288±270)ng/L,(1 897±98)ng/L,(498±47)ng/L]与阻断前比较差异无统计学意义(P>0.05)。结论 TLR4表达上调与小儿支原体肺炎发作有关,TLR4可上调炎性因子的表达引起支原体肺炎的发病。

Objective To evaluate the role and mechanism of Toll-like receptor 4( TLR4) in children with mycoplasma pneumonia. Methods Fifty cases with acute attack of mycoplasma pneumonia admitted to Tianjin Beichen District Women and Children Health Care Center during Jan. 2011 and Aug. 2014 were selected as an acute stage group,and 50 patients at stable stage of mycoplasma pneumonia and 50 healthy children from Tianjin Beichen District Women and Children Health Care Center and Tianjin Public Security Hospital during the same period were selected as a stable stage group and a healthy control group,respectively. The levels of TLR4,interleukin( IL)-6,IL-8,tumor necrosis factor( TNF)-α were tested.Results The contents of TLR4 mRNA in the acute stage group were higher than those in both the stable stage group and control group( 0. 034 ± 0. 010 vs 0. 016 ± 0. 008,0. 014 ± 0. 006,P < 0. 01). In the acute stage group,the levels of IL-6,IL-8 and TNF-α before TLR4 inhibition were higher than those in the control group[IL-6:( 8 352 ± 276) ng/L vs( 6 027 ±258) ng/L,IL-8:( 1 910 ± 100) ng/L vs( 510 ± 29) ng/L,TNF-α:( 355 ± 19) ng/L vs( 492 ± 77) ng/L,P < 0. 01].The levels of IL-6,IL-8 and TNF-α were significantly decreased after TLR4 blocking [( 7 510 ± 220) ng/L,( 980 ±90) ng/L,( 391 ± 23) ng/L]( P < 0. 01). However,the levels of IL-6,IL-8 and TNF-α were not significantly fluctuated after TLR2 block [( 8 288 ± 270) ng/L,( 1 897 ± 98) ng/L,( 498 ± 47) ng/L]P > 0. 05). Conclusion TLR4 upregulation is related with acute attack of mycoplasma pneumonia by promoting the inflammation expression of the inflammatory factors.