2023, Vol. 27 ›› Issue (11): 1692-1700

Hyperoxia-induced differential expression of microRNAs mediates lung injury in neonatal rats

Wang Lina, Zhang Rong, Kang Lan, Lei Xiaoping, He Hongxia, Dong Wenbin   

Abstract: BACKGROUND: The main pathological features of bronchopulmonary dysplasia are stagnation of lung development and minor tissue damage. Fetal lung development needs to go through five stages, and a preterm infant cannot survive after birth until the cystic stage. Therefore, research on the pathogenesis of premature birth- and hyperoxia-induced bronchopulmonary dysplasia has focused on cystic and alveolar phases.
OBJECTIVE: To investigate the regulatory role of differentially expressed microRNAs in hyperoxia-associated bronchopulmonary dysplasia during two developmental stages – cystic and alveolar stages.
METHODS: Newborn Sprague-Dawley rats were randomly into four groups: in 0 day group (n=10), rat lung tissue was taken immediately after birth; 4-, 7-, 14-day groups were further divided into two subgroups – hyperoxia group (exposed to persistent hyperoxia with an oxygen concentration of 85%-90%, n=10) and air group (exposed to the air with FiO2: 21%, n=10). Lung samples tissue were then taken at postnatal days 4, 7, 14. MicroRNAs in lung tissue were acquired using miRNA-Seq technology to build a library, and sequenced on the Illumina platform. Differently expressed microRNAs between different groups were screened by Deseq2 (Version 1.10.1) and Venn map. Gene ontology enrichment and protein-protein interaction analysis were performed to predict target proteins of differentially expressed microRNAs.
RESULTS AND CONCLUSION: There were 633 microRNAs in the 0-day group, 609, 614, and 584 microRNAs in the hyperoxia group at postnatal days 4, 7, 14, respectively, and 629, 608, and 581 in the corresponding air groups. The hyperoxia group obtained 130, 3, and 114 differentially expressed microRNAs during postnatal days 0-4 (cystic stage), 4-7, and 4-14 (alveolar stage), respectively. And the corresponding air group received 106, 0, 111 differentially expressed microRNAs respectively. There were 91, 0, and 79 differentially expressed microRNAs in the two groups at different stages. During the cystic and alveolar phases, miR-34a-5p and miR-21-5p were significantly expressed in the lung tissue of neonatal rats in the hyperoxia group. miR-34a-5p had 198 target proteins, which concentrated around the Pdgfrb/Pdgfra/Ngfr; miR-21-5p had 302 target proteins that mainly revolved around the Mapk1/Stat3. To conclude, miR-34a-5p and miR-21-5p are highly expressed in the cystic and alveolar stages under hyperoxia exposure, targeting the proteins about PDGFRB/PDGFRA/NGFR and MAPK1/Stat3 respectively, which mediate the process of lung development and participate in the occurrence and development of bronchopulmonary dysplasia.
Key words: bronchopulmonary dysplasia, microRNA high-throughput sequencing, miRNA-21-5p, miR-34a-5p, MAPK1/Start3, PDGFRB/PDGFRA/NGFR