ABSTRACT
Objective:To observe and verify the changes of transcriptome in hyperoxia-induced acute lung injury (HALI), and to further clarify the changes of pathways in HALI.Methods:Twelve healthy male C57BL/6J mice were randomly divided into normoxia group and HALI group according to the random number table, with 6 mice in each group. The mice in the normoxia group were fed normally in the room, and the mice in the HALI group was exposed to 95% oxygen to reproduce the HALI animal model. After 72 hours of hyperoxia exposure, the lung tissues were taken for transcriptome sequencing, and then Kyoto Encyclopedia of Genes and Genomes database (KEGG) pathway enrichment analysis was performed. The pathological changes of lung tissue were observed under light microscope after hematoxylin-eosin (HE) staining. Real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to verify the key molecules in the signal pathways closely related to HALI identified by transcriptomics analysis.Results:Transcriptomic analysis showed that hyperoxia induced 537 differentially expressed genes in lung tissue of mice as compared with the normoxia group including 239 up-regulated genes and 298 down-regulated genes. Further KEGG pathway enrichment analysis identified 20 most significantly enriched pathway entries, and the top three pathways were ferroptosis signaling pathway, p53 signaling pathway and glutathione (GSH) metabolism signaling pathway. The related genes in the ferroptosis signaling pathway included the up-regulated gene heme oxygenase-1 (HO-1) and the down-regulated gene solute carrier family 7 member 11 (SLC7A11). The related genes in the p53 signaling pathway included the up-regulated gene tumor suppressor gene p53 and the down-regulated gene murine double minute 2 (MDM2). The related gene in the GSH metabolic signaling pathway was up-regulated gene glutaredoxin 1 (Grx1). The light microscope showed that the pulmonary alveolar structure of the normoxia group was normal. In the HALI group, the pulmonary alveolar septum widened and thickened, and the alveolar cavity shrank or disappeared. RT-RCR and Western blotting confirmed that compared with the normoxia group, the mRNA and protein expressions of HO-1 and p53 in lung tissue of the HALI group were significantly increased [HO-1 mRNA (2 -ΔΔCt): 2.16±0.17 vs. 1.00±0.00, HO-1 protein (HO-1/β-actin): 1.05±0.01 vs. 0.79±0.01, p53 mRNA (2 -ΔΔCt): 2.52±0.13 vs. 1.00±0.00, p53 protein (p53/β-actin): 1.12±0.02 vs. 0.58±0.03, all P < 0.05], and the mRNA and protein expressions of Grx1, MDM2, SLC7A11 were significantly decreased [Grx1 mRNA (2 -ΔΔCt): 0.53±0.05 vs. 1.00±0.00, Grx1 protein (Grx1/β-actin): 0.54±0.03 vs. 0.93±0.01, MDM2 mRNA (2 -ΔΔCt): 0.48±0.03 vs. 1.00±0.00, MDM2 protein (MDM2/β-actin): 0.57±0.02 vs. 1.05±0.01, SLC7A11 mRNA (2 -ΔΔCt): 0.50±0.06 vs. 1.00±0.00, SLC7A11 protein (SLC7A11/β-actin): 0.72±0.03 vs. 0.98±0.01, all P < 0.05]. Conclusions:HALI is closely related to ferroptosis, p53 and GSH metabolism signaling pathways. Targeting the key targets in ferroptosis, p53 and GSH metabolism signaling pathways may be an important strategy for the prevention and treatment of HALI.
ABSTRACT
Mitophagy is the selective degradation of damaged mitochondria, and it is of great significance to maintain the normal quantity and quality of mitochondria to ensure cell homeostasis and survival. Necroptosis is a type of programmed cell necrosis that can be induced by excessive mitophagy. Reactive oxygen species (ROS) are produced mainly by mitochondria and can damage mitochondria. Hyperoxic acute lung injury (HALI) is a serious complication of clinical oxygen therapy, and its pathogenesis is not clear. Existing studies have shown that mitophagy and necroptosis are involved in the occurrence of HALI. There are many mechanisms regulating mitophagy and necroptosis, including tumor necrosis factor-α (TNF-α), E3 ubiquitin protein ligase (PINK1/Parkin) protein pathway encoded by PTEN-induced kinase 1/PARK2 gene, phosphoglycerate mutase 5 (PGAM5), etc. PGAM5 has been proved to be a key factor linking mitophagy and necroptosis. Previous studies of our team found that the mechanism of microRNA-21-5p (miR-21-5p) alleviating HALI was related to its pGAM5-mediated inhibition of mitophagy, but the mechanism of PGAM5-mediated mitophagy and necroptosis remains unclear. Therefore, this paper reviews the targets of PGAM5-mediated mitophagy and necroptosis, in order to find clues of lung protection of pGAM5-mediated mitophagy and necroptosis in HALI, and provide theoretical basis for subsequent basic research.
ABSTRACT
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are characterized by the destruction of the barrier function of alveolar epithelial cells and capillary endothelial cells and the recruitment of inflammatory cells, which leads to alveolar and interstitial edema, hyaline membrane formation and inflammatory infiltration of the lungs, etc. The mechanism is not completely defined. The current treatment plan focuses on comprehensive treatments such as ventilator support treatment, fluid management, and nutritional support, but the prognosis is still poor. Studies have shown that extracellular vesicle microRNA (miRNA) from different sources participate in regulating the function of epithelial cells, endothelial cells and phagocytes in different ways, thus aggravating or improving ALI, and have diagnostic, differential diagnosis and the therapeutic value. In this article, the mechanism, diagnostic and differerntial value of extracellular vesicle miRNA from different sources in ALI and the therapy of extracellular vesicle miRNA from stem cell in ALI are reviewed.