Bioinformatics and validation reveal the potential target of curcumin in the treatment of diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a common nerve-damaging complication of diabetes mellitus. Effective treatments are needed to alleviate and reverse diabetes-associated damage to the peripheral nerves. Curcumin is an effective neuroprotectant that plays a protective role in DPN promoted by Schwann cells (SCs) lesions. However, the potential molecular mechanism of curcumin remains unclear. Therefore, our aim is to study the detailed molecular mechanism of curcumin-mediated SCs repair in order to improve the efficacy of curcumin in the clinical treatment of DPN. First, candidate target genes of curcumin in rat SC line RSC96 cells stimulated by high glucose were identified by RNA sequencing and bioinformatic analyses. Enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) was carried out by Metascape, followed by 8 algorithms on Cytoscape to determine 4 hub genes, namly Hmox1, Pten, Vegfa and Myc. Next, gene set enrichment analysis (GSEA) and Pearson function showed that Hmox1 was significantly correlated with apoptosis. Subsequently, qRT-PCR, MTT assay, flow cytometry, caspase-3 activity detection and westernblot showed that curcumin treatment increased RSC96 cell viability, reduced cell apoptosis, increased Hmox1, Pten, Vegfa and Myc expression, and up-regulated Akt phosphorylation level under high glucose environment. Finally, molecular docking predicted the binding site of curcumin to Hmox1. These results suggest that curcumin can reduce the apoptosis of SCs induced by high glucose, and Hmox1 is a potential target for curcumin. Our findings provide new insights about the mechanism of action of curcumin on SC as a potential treatment in DPN.