RNA sequencing analysis reveals new findings of hyperbaric oxygen treatment on rats with acute carbon monoxide poisoning

Objective: To elucidate the altered gene network in the brains of carbon monoxide (CO) poisoned rats after treatment with hyperbaric oxygen (HBO2). Methods: RNA sequencing (RNA-seq) analysis was performed to examine differentially expressed genes (DEGs) in brain tissue samples from nine male rats: a normal control group; a CO poisoning group; and an HBO2 treatment group (three rats/group). Reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative PCR were used for validation of the DEGs in another 18 male rats (six rats/group). Results: RNA-seq revealed that two genes were up regulated (4.18 and 8.76 log to the base 2 fold change) (p<0.05) in the CO-poisoned rats relative to the control rats; two genes were upregulated (3.88 and 7.69 log to the base 2 fold change); and 23 genes were down regulated (3.49-15.12 log to the base 2 fold change) (p<0.05) in the brains of the HBO2-treated rats relative to the CO-poisoned rats. Target prediction of DEGs by gene network analysis and analysis of pathways affected suggested that regulation of gene expressions of dopamine metabolism and nitric oxide (NO) synthesis were significantly affected by CO poisoning and HBO2 treatment. Results of RT-PCR and real-ime quantitative PCR indicated that four genes (Pomc, GH-1, Pr1 and Fsh beta) associated with hormone secretion in the hypothalamic-pituitary system have potential as markers for prognosis of CO poisoning and efficacy evaluation of HBO2 treatment. Conclusion: This study is the first RNA-seq analysis profile of HBO2 treatment on rats with acute CO poisoning. It concludes that changes of hormone secretion in the hypothalamic-pituitary system, dopamine metabolism and NO synthesis involved in brain damage and behavior abnormalities after CO poisoning and HBO2 therapy may regulate these changes.