Figure 9.

The role and potential mechanism of M1 and M2 macrophages in the process of IDD. Macrophages take part in IDD mainly in M1 and M2 polarization rather than macrophage themselves. Specifically, M1CM inhibits cell proliferation and exacerbates IVD degeneration, while M2CM promote cell proliferation and attenuates IDD development. A total of 1038 DEGs were identified in M1CM treated NPCs, and 1905 DEGs in the M2CM group. Cell cycle was the most significant pathway enriched in KEGG enrichment, and organelle fission, nuclear division, and chromosome segregation were highly enriched in GO functional enrichment in both treatment NPCs. Finally, the five most significant genes in the M1CM group were PLK1, KIF20A, RRM2, CDC20, UBE2C and those in the M2CM groups were RRM2, CCNB1, CDC20, PLK1, and UBE2C. IDD, intervertebral disc degeneration; IVD, intervertebral disc.