Single-cell and experimental analyses identify mitochondrial dysfunction–related genes Hmgcs2, Nudt5, and Cpt1c in painful diabetic peripheral neuropathy

Painful diabetic peripheral neuropathy (PDPN) is a multifactorial disabling complication of diabetes, yet the pathogenesis involving mitochondrial dysfunction in immune cells remains unclear. This study aimed to identify mitochondrial dysfunction-related genes (MD-RGs) in PDPN and explore their mechanisms. Based on single-cell omics analysis, we identified three key MD-RGs (Hmgcs2, Nudt5, and Cpt1c) shared across different datasets and validated them in rat PDPN models. Gene set enrichment analysis revealed their association with cell polarity, sympathetic nerve development, and neurotransmitter pathways. We further observed distinct expression patterns of these genes in fibroblasts and macrophages within the dorsal root ganglion of PDPN. Hmgcs2 and Nudt5 were significantly downregulated in fibroblasts, while Cpt1c was upregulated. Conversely, Nudt5 and Cpt1c were significantly upregulated in macrophages, with Hmgcs2 downregulated. Functional enrichment analysis revealed that fibroblasts in PDPN primarily associated with polyamine/sulfate biosynthesis, while macrophages predominantly enriched for glycerol/choline metabolism, indicating distinct metabolic functions between the two cell types. Through molecular docking and dynamic simulation analysis, we further identified chlorothiazide and hydrochlorothiazide as stable binders to HMGCS2, suggesting potential as targeted therapeutics for PDPN. These findings indicate that Hmgcs2, Nudt5, and Cpt1c are key MD-RGs in the PDPN pathogenesis and provide novel therapeutic development strategies.