LincR-PPP2R5C regulates the PP2A signaling pathway in the macrophage-myofibroblast transition in a mouse model of epidural fibrosis.

Low back pain after spine surgery is a major complication due to excessive epidural fibrosis, which compresses the lumbar nerve. Macrophage-myofibroblast transition (MMT) promoted epidural fibrosis in a mouse laminectomy model. Previously, we demonstrated that LincR-PPP2R5C regulated CD4 + T-cell differentiation. Here, we aimed to explore the roles and mechanisms of LincR-PPP2R5C in macrophages in epidural fibrosis. In M2 macrophages, the level of LincR-PPP2R5C was significantly decreased. Upon overexpression, LincR-PPP2R5C induced M1-macrophage polarization and reduced MMT. In contrast, LincR-PPP2R5C deficiency promoted M2-macrophage polarization and increased MMT. Mechanistically, LincR-PPP2R5C modulated the expression of α-SMA in macrophages via the PP2A signaling pathway. In vivo, LincR-PPP2R5C deficiency aggravated epidural fibrosis by enhancing MMT in a mouse model of laminectomy, and this effect was abolished in mice with macrophage depletion. Our study shed light on the effects of LincR-PPP2R5C on macrophage differentiation and MMT in epidural fibrosis.