LncRNA SNHG6 accelerates hyperoxia-induced lung cell injury via regulating miR-335 to activate KLF5/NF-κB pathway.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a common chronic lung disease in premature infants, and its pathogenesis has not been clarified. Long non-coding RNAs (lncRNA) have important functions in cell bioactivity. However, their role in developmental lung disease remains unclear. OBJECTIVE: The aim of this study was to demonstrate the role of lncRNA SNHG6 (SNHG6) in BPD and its underlying mechanisms. METHODS: The blood of patients with BPD were collected, and BPD model of BEAS-2B cells was established by hyperoxia method. SNHG6, miR-335 and KLF5 mRNA expression were detected by RT-qPCR. Western blot was conducted to measure the levels of apoptosis-related proteins' expression and NF-κB pathway related proteins. BEAS-2B cell viability and apoptosis were assessed by CCK-8 and flow cytometry, respectively. Assay Kit was applied to detect ROS, MDA and SOD levels, respectively. ELISA was performed to assess the levels of inflammatory factors. The binding site of miR-335 with SNHG6 or KLF5 were predicted by using DIANA or TargetScan, and which was verified by double luciferase reporter assay. RESULTS: Firstly, SNHG6 was highly expressed and miR-335 was lowly expressed in BPD model, SNHG6 knockdown and miR-335 mimics both alleviated hyperoxia-induced lung cell injury, and SNHG6 targeted miR-335. Subsequently, KLF5 was targeted by miR-335, and KLF5 promoted lung cell injury via activating NF-κB pathway. Furthermore, SNHG6 mediated lung cell injury via regulating the miR-335/KLF5/NF-κB pathway. CONCLUSION: Our research confirmed that SNHG6 mediated hyperoxia-induced lung cell injury via regulating the miR-335/KLF5/NF-κB pathway. These findings suggest that SNHG6 serves as promising targets for the treatment of newborns with BPD.

ETS1 Ameliorates Hyperoxia-Induced Alveolar Epithelial Cell Injury by Regulating the TGM2-Mediated Wnt/ß-Catenin Pathway.

PURPOSE: Bronchopulmonary dysplasia (BPD) is a chronic lung disease that affects newborns who need oxygen therapy, and high-concentration oxygen therapy may cause neonatal morbidity and mortality in newborns. E26 oncogene homologue 1 (ETS1) and transglutaminase 2 (TGM2) have been reported to be associated with lung cell injury. However, the mechanism of ETS1 in regulating BPD is still unclear. METHODS: Hyperoxia-induced A549 cells to simulate hyperoxia-induced alveolar epithelial cell injury. MTT assays and colony formation assays were performed to investigate the proliferation of A549 cells. Flow cytometry was carried out to quantify the apoptosis of A549 cells. The expression levels of ETS1 and TGM2 were quantified by qRT-PCR. The protein expression levels of ETS1, TGM2, ß-catenin, c-Jun and MET were measured by western blot. Overexpression of ETS1, overexpression of TGM2, overexpression of ETS1 with downregulation of TGM2 and overexpression of TGM2 with inhibition of Wnt/ß-catenin pathway were performed to investigate the role of ETS1, TGM2 and Wnt/ß-catenin pathways in hyperoxia-induced alveolar epithelial cell injury. RESULTS: Hyperoxia decreased the proliferation and promoted the apoptosis of cells in a time-dependent manner. Moreover, overexpression of ETS1 rescued the effect of hyperoxia on proliferation and apoptosis. In addition, overexpression of TGM2 participated in the regulation of hyperoxia-induced proliferation and apoptosis. ETS1 regulated hyperoxia-induced alveolar epithelial cell injury through the Wnt/ß-catenin pathway via TGM2. CONCLUSION: ETS1 ameliorates hyperoxia-induced alveolar epithelial cell injury through the TGM2-mediated Wnt/ß-catenin pathway.

Angiogenesis-related genes may be a more important factor than matrix metalloproteinases in bronchopulmonary dysplasia development.

We characterized the expression profile of angiogenesis-related genes (ARG) and matrix metalloproteinase (MMP) genes in preterm infants, with and without bronchopulmonary dysplasia (BPD). We reanalyzed a gene expression dataset for preterm infants from the Gene Expression Omnibus database using the Gene-Cloud of Biotechnology Information platform. A total of 1,652 genes were differentially (1.2-fold change) expressed: 811 were highly expressed in infants with BPD, and 841 were highly expressed in those without BPD. Twenty-eight and 11 ARGs were upregulated in infants with and without BPD, respectively. Among 27 detected MMPs and TIMPs, MMP8, MMP9, MMP25, TIMP2 and TIMP3 were differently expressed. Levels of THBS1, MMP8, MMP9, MMP25, TIMP2 and TIMP3 increased as severity of BPD and retinopathy of prematurity (ROP) increased, whereas ETS1, LEF1 and SPOCK2 exhibited the opposite trend. Expression of ETS1 and LEF1 had a fitting rate of R2 = 0.849 and P < 0.001. ELISAs showed a positive correlation between THBS1 and CD36 (receptor of THBS1) levels in serum samples from preterm infants. Our study indicates that the upregulation of THBS1 and downregulation of ETS1, LEF1 promotes BPD in preterm infants by disrupting blood vessel formation rather than by dysregulation of MMPs and TIMPs.