[Transcriptomic characteristics of cervical endplate cartilage in cervical spondylosis and effects of acupotomy on the FGF18/Akt axis with cervical spondylosis].

OBJECTIVES: To explore the transcriptomic characteristics of the endplate cartilage of the cervical intervertebral disc in cervical spondylosis (CS) and the effects of acupotomy on expressions of fibroblast growth factor 18 (FGF18)/protein kinase B (Akt) axis key molecules. METHODS: Transcriptomic analyses were performed using bioinformatics methods based on the GEO database. In the animal experiment, 24 New Zealand rabbits were randomized equally into control, CS model, and acupotomy groups. In the latter two groups, CS models were established followed 7 days later by acupotomy intervention (once a week for 3 weeks) or no particular treatment. Histopathological changes and cell apoptosis in the intervertebral discs were examined with HE staining and TUNEL assay, and the mRNA expressions of FGF18, FGFR3, and Akt in the intervertebral discs were detected using RT-qPCR; the localization and expressions of FGF18, p-Akt, and Akt proteins were examined with immunohistochemistry. RESULTS: The endplate cartilage in CS exhibited numerous differentially expressed genes enriched in the PI3K-Akt signaling, calcium signaling, and Rap1 signaling pathways. CS rabbits showed obvious changes in the cervical spine curvature and joint degenerations, changes in cervical intervertebral disc texture, thinning of the annulus fibrosus, shrinkage or even absence of the nucleus pulposus, and increased apoptotic cells in the endplate cartilage, which were all obviously alleviated after acupotomy. No significant differences were found in the mRNA expressions of FGF18, FGFR3, and Akt in the cervical intervertebral discs among the 3 groups. Acupotomy significantly increased FGF18 and p-Akt protein expressions and reduced the Akt/p-Akt ratio in the cervical endplate cartilage of CS rabbits. CONCLUSIONS: The cervical endplate cartilage of CS show numerous differentially expressed genes. Acupotomy may delay degenerative changes of the intervertebral discs and improves CS by activating the FGF18/Akt axis to reduce apoptosis of endplate cartilage cells.