LINC00687 Regulates PRDX2 Expression in High Glucose-Induced Nonunion after Digital Replantation

Diabetic nonunion is a major clinical challenge with unclear molecular mechanisms. This study systematically investigated the key genes and molecular mechanisms of bone nonunion after finger replantation induced by high glucose using Gene Expression Omnibus (GEO), bioinformatics, and experimental analyses. In total, 179 differentially expressed mRNAs and one lncRNA (DElncRNA) were identified using the GEO dataset. Functional enrichment analysis showed that these genes were mainly involved in the regulation of autophagy and metabolism. Protein-protein interaction network analysis identified five core genes (Peroxiredoxin 2 [PRDX2], FK506 binding protein 8 [FKBP8], SHANK-associated RH domain interactor [SHARPIN], WD repeat domain 45 [WDR45], and gamma-aminobutyric acid type A receptor-associated protein like 2 [GABARAPL2]), three of which exhibited good binding affinities for potential therapeutic agents. Immune infiltration analysis revealed significant differences in the CD8+ T cell proportions between nonunion and healthy samples. We constructed a competitive endogenous RNA network (long intergenic non-protein coding RNA 687 [LINC00687]-miR-4443-PRDX2) and verified its direct regulatory interaction using a dual-luciferase reporter assay. FKBP8, PRDX2, SHARPIN, WDR45, and GABARAPL2 were overexpressed in tissue samples from patients with type 2 diabetes mellitus fracture nonunion. Animal experiments further confirmed that LINC00687 upregulated PRDX2 expression by sponging miR-4443 in a hyperglycemic environment, thereby inhibiting bone healing. This study not only identified PRDX2 and other genes as potential biomarkers of diabetic nonunion but also clarified the regulatory role of the LINC00687/miR-4443/PRDX2 axis in hyperglycemia-induced nonunion, providing a new molecular target for clinical prevention and treatment.