Comprehensive serum CircRNA profiling identifies CircRNA_103372 as a novel diagnostic biomarker for intervertebral disc degeneration.

OBJECTIVE

To investigate the different expression patterns of circular RNAs (circRNAs) in the serum of patients with intervertebral disc degeneration (IDD).

METHODS

The circRNA microarrays were utilized to detect differential expression profiles in the serum of patients with IDD. Bioinformatics tools such as Gene Ontology analysis, Venn analysis, and protein-protein interaction (PPI) network construction were employed to identify functional molecules potentially linked to IDD. The interaction among 00, miR-205-5p, and cyclic-AMP (cAMP)-response element-binding protein 1 (CREB1) was validated using qRT-PCR and immunohistochemistry (IHC).

RESULTS

A total of 401 differentially expressed circRNAs were identified, with circRNA_103372 showing a significant down-regulation in nucleus pulposus (NP) tissues and serum of patients with IDD (FC = 3.23, p = 0.007). Subsequently, an interaction network involving circRNA_103372-miR-205-5p-CREB1 was constructed. Furthermore, qRT-PCR validation demonstrated that in degenerated human NP cells, both circRNA_103372 and CREB1 were downregulated, whereas hsa-miR-205-5p was upregulated. Furthermore, IHC confirmed the expression pattern of CREB1 in both rat and human IDD samples, revealing a significant reduction in CREB1 expression.

CONCLUSIONS

Serum circRNA_103372 is significantly down-regulated in patients with IDD and may be a novel, non-invasive circulating biomarker for IDD.