The complex association between the immune system and the skeletal system in osteoporosis: A study of single-cell RNA sequencing.

Objective: Osteoporosis (OP) is a disease characterized by decreased bone mass, deteriorated microstructure, and increased fragility and fracture risk. The diagnosis and prevention of OP and its complications have become major public health challenges. Therefore, exploring the complex ecological connections between the immune and skeletal systems may provide new insights for clinical prevention and treatment strategies.

Methods: First, we performed single-cell RNA sequencing on human lumbar lamina tissue and conducted clustering and subgroup analysis of quality-controlled single-cell transcriptome data to identify target subgroups. Subsequently, enrichment analysis and pseudotime analysis were performed. In addition, we conducted in-depth studies on the gene regulatory network between different cell subgroups and the communication between bone immune cells.

Results: In this study, we identified several cell subgroups that may be involved in the progression of OP. For example, the CCL4 NKT and CXCL8 neutrophils subgroups promote OP progression by mediating an inflammatory environment that disrupts bone homeostasis, and the MNDA Mac subgroup promotes osteoclast differentiation to promote OP. Moreover, the TNFAIP6 Obl, NR4A2 B and HMGN2 erythrocyte subgroups promoted the balance of bone metabolism and suppressed OP. In the cell communication network, Obl closely interacts with immune cell subgroups through the CXCR4-CXCL12, CTGF-ITGB2, and TNFSF14-TNFRSF14 axes.

Conclusion: Our research revealed specific subgroups and intercellular interactions that play crucial roles in the pathogenesis of OP, providing potential new insights for more precise therapeutic interventions for OP.