RESUMO
Background: Low back pain or sciatic pain because of lumbar intervertebral disc herniation (LDH) is caused by mechanical compression and/or an inflammatory component on the nerve root. However, it is difficult to define to what extent each component contributes to the pain. This study attempted to explore the effects of macrophage polarization on clinical symptoms in patients experiencing LDH after surgery, and investigated the association between macrophage cell percentages and clinical efficacy. Methods: This study retrospectively harvested nucleus pulposus (NP) tissue samples from 117 patients. Clinical symptoms and efficacy using the visual analog scale (VAS) and Oswestry Disability Index (ODI) were evaluated at different time points preoperatively and postoperatively. CD68, CCR7, CD163, and CD206 were selected as macrophage phenotypic markers. Results: Seventy-six samples showed positive expression of macrophage markers in NP samples of patients with LDH, whereas 41 patients displayed negative results. No significant differences were detected between the two groups, involvement of several demographic data, and preoperative clinical findings. With respect to the macrophage-positive group, no significant correlation was detected between the positive rate of the four markers and the VAS score or ODI after surgery. However, patients with NP samples positive for CD68 and CCR7 expression showed significantly lower VAS scores 1 week after surgery compared with those in the negative group. Moreover, the improvement in VAS score showed a strong positive correlation with CD68- and CCR7-positive cell percentages. Conclusions: Our results indicated that pro-inflammatory M1 macrophages may be associated with the reduction of chronic pain after surgery. Therefore, these findings contribute to better personalized pharmacological interventions for patients with LDH, considering the heterogeneity of pain.
RESUMO
Macrophage infiltration and polarization have been increasingly observed in intervertebral disc (IVD) degeneration (IDD). However, their biological roles in IDD are still unrevealed. We harvested conditioned media (CM) derived from a spectrum of macrophages induced from THP-1 cells, and examined how they affect nucleus pulposus cells (NPCs) in vitro, by studying cell proliferation, extracellular matrix (ECM) synthesis, and pro-inflammation expression; and in vivo by injection CM in a rat IDD model. Then, high-throughput sequencing was used to detect differentially expressed genes (DEGs). Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) networks were used to further analysis. Higher CCR7+ (M1 marker) and CD206+ (M2 marker) cell counts were found in the degenerated human IVD tissues as compared with the control. Furthermore, the cell co-culture model showed M1CM attenuated NPC proliferation, downregulated the expression of ECM anabolic genes encoding aggrecan and collagen IIα1, upregulated the expression of ECM catabolic genes encoding MMP-13, and inflammation-related genes encoding IL-1ß, IL-6, and IL-12, while M2CM showed contrasting trends. In IDD model, higher histological scores and lower disc height index were found following M1CM treatment, while M2CM exhibited opposite results. M1CM injection decreased ECM anabolic and increased ECM catabolic, as well as the upregulation of inflammation-related genes after 8 weeks treatment, while M2CM slowed down these trends. Finally, a total of 637 upregulated and 655 downregulated genes were detected in M1CM treated NPCs, and 975 upregulated genes and 930 downregulated genes in the M2CM groups. The top 30 GO terms were shown and the most significant KEGG pathway was cell cycle in both groups. Based on the PPI analysis, the five most significant hub genes were PLK1, KIF20A, RRM2, CDC20, and UBE2C in the M1CM groups and RRM2, CCNB1, CDC20, PLK1, and UBE2C in the M2CM groups. In conclusion, macrophage polarization exhibited diverse roles in IDD progression, with M1CM exacerbating cell proliferation suppression and IVD degeneration, while M2CM attenuated IDD development. These findings may facilitate the further elucidation of the role of macrophage polarization in IDD, and provide novel insights into the therapeutic potential of macrophages.