Study on the Mechanism of BMSCs in Regulating NF-κB Signal Pathway by Targeting miR-449a to Improve the Inflammatory Response to Peripheral Nerve Injury.

Objective: To evaluate the mechanism of Bone Marrow Mesenchymal Stem Cells (BMSCs) in regulating NF-κB signal pathway by targeting miR-449a.

Methods: Stem cells were transfected by over-expressing and inhibiting miR-449a to detect the levels and viability of miR-449a in stem cells after transfection. Stem cells and neurons were co-cultured in vitro to evaluate the in vitro mechanism of stem cells over-expressing miR-449a on neurons.

Results: After the addition of neurons, the neuronal activity of miR-449a over-expression group increased significantly, the expression of NF-κB signal pathway proteins (IκBα, p50, and p65) decreased, and the inflammatory cytokines (TNF-α and IL-1β) decreased significantly (P<0.05). In vivo experiments in rats also showed that rats were unresponsive, did not chirp or elude after being stimulated. After stem cell therapy, the weight and response of rats gradually returned to normal levels. miR-449a expression significantly increased in the stem cell + miR-449a over-expression group, expression of NF-κB signal pathway proteins (IκBα, p50, and p65) decreased, inflammatory cytokines (TNF-α and IL-1β) significantly decreased, and cell activity significantly increased (P<0.05).

Conclusions: BMSCs can modulate NF-κB signaling pathway by targeting miR-449a, so as to reduce the inflammatory response to peripheral nerve injury and repair nerve injury.