miR-340-5p alleviates the damage effect of LPS on nucleus pulposus cells by negatively regulating the expression of SOX4.

BACKGROUND

Previous studies show that about 80% of lumbar disc degeneration (LDD) patients experience back or leg pain, affecting their quality of life. However, the causes of LDD are not fully understood. This study focused on exploring the expression level of miR-340-5p and SRY-related high-mobility-group box 4 (SOX4) in LDD and attempts to clarify its potential mechanism in the pathological process of LDD.

METHODS

A total of 88 patients with LDD and 80 non-LDD patients were continuously included in this study. The miR-340-5p levels in nucleus pulposus (NP) tissues were measured using Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR). The potential diagnostic significance of miR-340-5p for LDD was evaluated by generating a Receiver Operating Characteristic (ROC) curve. The impacts of miR-340-5p on Lipopolysaccharide (LPS)-stimulated NP cells were analyzed through the Cell Counting Kit-8 (CCK-8) method, and apoptosis levels were quantified using flow cytometry. Additionally, the concentrations of inflammatory cytokines and extracellular matrix (ECM) remodeling markers were assessed with Enzyme-Linked Immunosorbent Assay (ELISA) kits.

RESULTS

miR-340-5p was abnormally down-regulated in LDD patients and the ROC curve showed that miR-340-5p has diagnostic value for LDD (AUC = 0.909, sensitivity = 81.8%, specificity = 85.0%, cutoff value = 0.815). Additionally, the enforced expression of miR-340-5p promoted proliferation and ECM remodeling and inhibited the level of apoptosis and pro-inflammatory factors in LPS-damaged NP cells. However, overexpression of SOX4 counteracted the effects of miR-340-5p overexpression on LPS-induced NP cells.

CONCLUSIONS

miR-340-5p alleviates the damage effect of LPS on NP cells by negatively regulating the SOX4, and miR-340-5p may be a potential therapeutic target for LDD.