MiRNA Expression In The Peripheral Blood Of A Neonatal Rat Hypoxia-Ischemia Model Of Self-Resuscitated Rats

Background/Aims:The hypoxia-ischemia is the predominant neurologic lesion in preterm infants who survive brain injury.In this study,we assessed the changes in profiles of microRNAs?miRNAs?in the peripheral blood of SD rats with hypoxia-ischemia of self-resuscitated.We attempted to find highly differentiated miRNA to provide biological indicators for clinical diagnosis and prognosis of hypoxia-hypoxia brain damage?HIBD?.Methods:?1?The newborn mouse HI model was established:P4 baby mice were separated from the mother mouse and exposed to hypoxia for 7 minutes?pure N₂[100%]was used in a closed container?.After N₂ was injected for 1-2 minutes,the body cyanosis was observed in the experiment.About 5 minutes later,each baby mouse was accompanied by decreased mobility and convulsions until it was paralyzed.At the end of hypoxia treatment,the pups were put back into the rearing cage and self-resuscitated.?2?Preparation of peripheral blood next generation sequence?NGS?sequencing specimens:1 SD mouse was anaesthesia sacrificed in each group of HI and the control group.Abdominal lamination was performed to separate the abdominal aorta.1 ml of blood was collected by puncture and placed in a 1.5ml tapered bottom tube and stored at-80°C for standby sequencing.High throughput deep second-generation sequencing was used to the expression profiles of miRNA in peripheral blood of hypoxia-ischemia?HI?group and control group of newborn SD rats?day 4 after birth?.?3?Bioinformatics analysis:the related cell signaling pathways and functions were predicted using Gene Ontology?GO?and Kyoto Encyclopedia of Genes and Genomes?KEGG?.MiRBase 22.1 database was used to predict miRNA and HIBD related target genes.Results:A total of 1049 mature reliable miRNAs were discovered in the peripheral blood of rats with HI injury.The types of miRNA in the control group were 525.There were 524 miRNA species in the HI group.Among them,27 miRNA types in the control group were different from those in the HI group,and the miRNA types were highly correlated between the two groups.A total of 38 more reliable miRNA were dysregulated in rats with HI injury,indicating a potential role in the condition.A total of 38 miRNA were identified to be differentially expressed(fold change[2^-??Ct]>2.5 and P value<0.05)in HI rats compared with the control group,including 21upregulated and 17 downregulated miRNAs.The glutamatergic synapse pathway,myelin lipid metabolism,neural activity ligand-receptor interaction and the vascular epithelial growth factor?VEGF?signaling pathway,both associated with hypoxia/ischemia injury induced rats,were in over activated.Some of the target genes in these significantly up-regulated or down-regulated miRNAs are highly correlated with the occurrence of HIBD,central nervous system development in infancy,and possible clinical sequelae.There was no significant difference in the brain tissue between to two groups,and the white matter under the cortex and corpus callosum not exhibited leukoaraiosis,ventricles were expanded,the arrangement of neurons in the gray matter was disordered,and apoptosis was evident.Conclusion:Compared with newborn rats in the control group,this experiment found differential expression of miRNA in the brain tissue of the HI model rats.In this study,we have identified miR-200 family,miR-471 family,miR-429,miR-216 and miR-871could assist the development of novel diagnostic biomarker.The miRNA lineage of HI lesions established in this study can be helpful to the diagnosis and prognosis of HIBD in the future,and provide ideas for the development of more biotherapy of RNA interference in the future.