基于miR-223-3p/NLRP3轴研究右美托咪定对机械通气肺损伤大鼠炎性反应的影响

A study of the effect of dexmedetomidine on the inflammatory response of rats with mechanical ventilation lung injury based on miR-223-3p/NLRP3 axis

目的本研究通过建立机械通气性肺损伤(ventilator-induced lung injury,VILI)大鼠模型,探究右美托咪定(dexmedetomidine,DEX)对其炎性反应及微小RNA-223-3p/核苷酸结合寡聚化结构域样蛋白3(NLRP3)轴的影响。方法将60只成年健康6周龄SPF级雄性SD大鼠采用随机数字表法随机分为5组:对照组(NC组)、模型组(M组)、低(L-DEX组)、中(M-DEX组)、高(H-DEX组)剂量DEX组,每组12只;L-DEX组、M-DEX组、H-DEX组在机械通气中分别以静脉滴注0.5、2.5、5.0μg/(kg·h)DEX。4 h末处死,检测各组大鼠肺通透指数(lung permeability index,LPI)、肺组织湿重/干重(wet weight/dry weight,W/D)比值、肺组织miR-223-3p、NLRP3 mRNA及蛋白、caspase-1蛋白表达水平及肺组织匀浆中白细胞介素-1β(IL-1β)、IL-18水平。结果与M组比较,L-DEX组、M-DEX组、H-DEX组大鼠LPI、W/D比值、NLRP3 mRNA(4.04±0.38、2.12±0.32、1.98±0.25)及NLRP3蛋白(0.92±0.11、0.58±0.06、0.39±0.02)、caspase-1蛋白、IL-1β、IL-18水平依次降低(M组NLRP3 mRNA为5.47±0.62,NLRP3为1.31±0.27),miR-223-3p水平依次升高(均P<0.05)。结论 DEX可能通过上调miR-223-3p表达,下调NLRP3、caspase-1蛋白及下游炎症因子表达,与miR-223-3p/NLRP3轴密切相关,减轻大鼠VILI及炎症反应。

Objective The ventilator-induced lung injury(VILI) rat model was established in this study to explore the influence of DEX on its inflammatory response and the axis of microRNA-223-3 p/nucleotide binding oligomeric domain-like protein 3(miR-223-3 p/NLRP3). Methods The adult healthy 6-week-old Specific pathogen-free(SPF) grade male SD rats of were randomly divided into 5 groups using the random number table: control group(NC group), model group(M group), low dose DEX group(L-DEX group), medium dose DEX group(M-DEX group), high dose(H-DEX group) DEX group, 12 rats in each group;the rats were given 0.5, 2.5 and 5.0 μg/(kg·h) DEX intravenously in L-DEX group, M-DEX group and H-DEX group respectively. At the end of 4 h, the rats were sacrificed and the lung permeability index(LPI) and the ratio of lung tissue wet weight to dry weight(W/D), miR-223-3 p, NLRP3 mRNA and protein, caspase-1 protein expression and IL-1β and IL-18 levels in lung homogenate were measured. Results Compared with group M, the LPI, W/D ratio, NLRP3 mRNA(4.04±0.38, 2.12±0.32, 1.98±0.25) and NLRP3 protein(0.92±0.11, 0.58±0.06, 0.39±0.02), caspase-1 protein, IL-1β, IL-18 levels in L-DEX group, M-DEX group and H-DEX group decreased in turn, while NLRP3 mRNA in group M was 5.47±062, and NLRP3 protein was 1.31±0.27), and the level of miR-223-3 p increased in turn in the L-DEX group, M-DEX group, H-DEX group(P<0.05). Conclusion DEX may up-regulate the expression of miR-223-3 p, down-regulate the expression of NLRP3, caspase-1 and downstream inflammatory factors, which is closely related to the miR-223-3 p/NLRP3 axis, so as to reduce the VILI and inflammatory response in rats.