Differential Expression Profile And Function Analysis Of Circular RNA In Human Nucleus Pulposus Cells Under Compression Stress

Objective:Low back pain caused by intervertebral disc degeneration(IDD)is very common in modern society,causing a heavy social burden and a decline in the quality of life of patients.IDD is a pathological process mediated by multiple factors,in which compression-stimulated nucleus pulposus cell damage plays a key part.Studies have found that circular RNA(circRNA),as a type of endogenous non-coding RNA,plays an important role in the pathogenesis of many diseases.However,the relationship between circRNA and compression-induced nucleus pulposus cell damage remains unclear.This project aimed to explore the differential expression profile of circRNA in human nucleus pulposus cells under compression stimulation,and to further analyze its potential biological functions and mechanism through bioinformatics.Methods:The Trizol method was used to extract total RNA from three control nucleus pulposus cell samples and three compression-treated nucleus pulposus cell samples,and the purity and concentration of RNA were determined by Nano Drop ND-1000.Using microarray assays to screen out the differentially expressed circRNA under compression stimulation.The qRT-PCR technique was used to verify the expression of differentially expressed circRNA in control nucleus pulposus cells and compression-stimulated nucleus pulposus cells.The bioinformatics database was used to predict and analyze the mi RNA binding sites of the differentially expressed circRNA,and the luciferase reporter gene experiment was used to detect and analyze the direct effect of circRNA on its potential targeted binding mi RNA.Result:This project has successfully constructed the differential expression profile of circRNA in human nucleus pulposus cells under compression stimulation.A total of1784 significantly differentially expressed circular RNAs were detected from the two groups of nucleus pulposus cell samples,including 286 differentially up-regulated and1498 differentially down-regulated.From the down-regulated circRNA,part of them were further screened for qRT-PCR verification.The results showed that the expression pattern of circRNAs was consistent with the circRNAs detected by the microarray assays,and the fold change of hsa＿circ＿0044722 was the most significant.Bioinformatics analysis predicted the potential mi RNA binding sites of hsa＿circ＿0044722,and we further confirmed that hsa＿circ＿0044722 can directly sponge mi R-34a-5p to regulate the expression of target genes.Conclusion: Differential expression changes of circRNAs occurred in the disc nucleus pulposus cells under compression stimulation,and most of the circRNAs was down-regulated due to compression stimulation.The significantly down-regulated hsa＿circ＿0044722 could function as a mi RNA sponge to bind to mi R-34a-5p.Circ RNA played a very important role in compression-induced nucleus pulposus cell damage.