Integrated multi-omics analysis identifies lipid metabolism biomarkers in ONFH and reveals therapeutic potential of retinoic acid.

Osteonecrosis of the femoral head (ONFH) is a debilitating condition frequently associated with dysregulation in lipid metabolism. The objective of this study was to identify potential biomarkers for ONFH through various analytical methods and experimental verification, thereby providing a robust reference for disease treatment. Utilizing public datasets, differential analysis was conducted and integrated with weighted gene co-expression network analysis to pinpoint key genes. Subsequently, biomarkers related to lipid metabolism in ONFH were identified by combining machine learning techniques with receiver operating characteristic curves. Furthermore, based on these biomarkers, a nomogram model was developed for diagnostic prediction. Immune infiltration was assessed, and drug predictions involved molecular docking studies. Finally, the relationship between biomarkers and immune cells was investigated through single-cell analysis. Then the system experiment is carried out to verify. Thirty key genes were identified, primarily enriched in "phospholipid metabolic processes" and "lysosome". A total of three biomarkers-CREBBP, GLB1, and PSAP-were recognized as exhibiting strong diagnostic efficacy. The nomogram incorporating these biomarkers demonstrated accurate predictive capabilities. Immune infiltration analysis revealed altered levels of neutrophils and activated dendritic cells in ONFH that correlated with biomarker expression. Additionally, molecular docking studies indicated stable interactions between the identified biomarkers and potential therapeutic agents such as estradiol and retinoic acid. Single-cell sequencing analysis uncovered significant differences in biomarker expression across various immune cell types including T cells. Finally, it was verified that retinoic acid improved ONFH by hsa-miR-320a/GLB1 in vitro and in vivo. This study identifies CREBBP, GLB1, and PSAP as promising biomarkers for ONFH while underscoring their potential roles in lipid metabolism and immune modulation. Moreover, we confirmed the important conclusion that retinoic acid improves ONFH through hsa-miR-320a/GLB1. Future investigations into the therapeutic implications of these findings may offer new avenues for ONFH management.