Abstract: Objective To investigate the dynamic changes of leukotriene C4 (LTC4), type 2 innate lymphoid cell(ILC2) and related cytokines (IL-4, IL-5 and IL-13) in the lung tissue of mice with bronchopulmonary dysplasia (BPD). Methods C57BL / 6 mice were randomly divided into air group and hyperoxia group.The hyperoxia group was exposed to 85% oxygen for 1, 7 and 14 days to replicate the BPD model.HE staining microscopy was used to observe the pathological changes of the lung tissue of mice. The percentages of ILC2 and CysLT1R⁺ILC2 were detected by flow cytometry.The contents of LTC4, IL-4, IL-5 and IL-13 were detected by ELISA.Western blot was used to detect the expression of LTC4-C synthase (LTC4S).RT-qPCR was used to detect the mRNA expression of LTC4S and cysteine leukotriene type 1 receptor (CysLT1R). Results Compared with air group, the percentage of ILC2 and CysLT1R⁺ILC2 in hyperoxia group and the expression of CysLT1R mRNA all increased(P＜0.05);The expression of IL-4, IL-5 and IL-13 in the hyperoxia group increased and were higher than those in the air group at the same time point (P＜0.05);LTC4 content, LTC4S protein and mRNA expression were significantly increased in hyperoxia group (P＜0.05). Conclusions In BPD, LTC4 increases and may induce the increase of ILC2 and related cytokines (IL-4, IL-5 and IL-13) through CysLT1R.

Key words: leukotriene C4, type 2 innate lymphocytes, type 2 inflammatory response, bronchopulmonary dysplasia