Mechanism of protective role of miR-874-3p in intervertebral disc degeneration.

Background: The intervertebral disc can increase the amplitude of spinal motion, withstand pressure, buffer vibration, and protect the brain and spinal cord. It is also the main reason why height changes, but the regulatory mechanism is still unclear, and this study mainly explored the role of miR-874-3p in intervertebral disc degeneration (IDD).

Methods: The mechanism and perform correlation analysis of miR-874-3p and the pathological degree and prognosis of patients with IDD. miR-874-3p is involved in the progression of several diseases, such as cell differentiation, proliferation, apoptosis and extracellular matrix degradation, overexpressing cell line GV369-miR-874-3p-NP was obtained by infected nucleus pulposus (NP) cells, and the empty vector GV369-NP group was set with the blank group. The expression of the tag protein (green fluorescent protein, GFP) was visualized by fluorescence microscopy, followed by real-time polymerase chain reaction (PCR) method to detect miR-874-3p expression, apoptosis by flow cytometry, luciferase reporter analysis for verifying the targeting relationship between miR-874-3p, caspase-3, B-cell lymphoma-2 (Bcl-2) and Bax in cells, and examined the changes in cellular mitochondrial membrane potential using kits.

Results: The expression of miR-874-3p was significantly reduced in IDD patients, and was negatively correlated with matrix metallopeptidase 2 (MMP2) and downregulated matrix metallopeptidase 3 (MMP3) in the NP cells. In addition, western blot revealed that overexpression of miR-874-3p increased the aggregation protein level in the NP cells.

Conclusions: miR-874-3p can inhibit the cell death of IDD, and not only participate in caspase-3 and Fas-associating protein with a novel death domain (FADD)-mediated apoptosis through targeted regulation of exogenous MMP2/MMP3 pathway, but also play a role in cell apoptosis through mitochondrial pathway.