Nutrient-sensing mechanisms in painful diabetic peripheral neuropathy: identification of hub miRNA-mRNA regulatory networks via multi-omics sequencing of the dorsal root ganglia

Painful diabetic peripheral neuropathy (PDPN) is a common and debilitating complication of diabetes mellitus, with complex clinical manifestations and pathogenesis. From the perspective of PDPN progression, how nutrient sensing alters gene transcription represents a scientifically significant question worthy of investigation. However, the underlying molecular mechanisms, particularly the association between post-transcriptional regulatory processes in the dorsal root ganglia (DRG) and PDPN, remain poorly understood. Therefore, this study employed an integrated multi-omics approach to comprehensively profile the miRNA and mRNA expression landscape and analyze their regulatory networks in the DRG of a well-established rat model of PDPN.

Eighteen male SD rats (aged 4 to 5 weeks, weighing 90 to 100 g) were randomly divided into a vehicle control group and a PDPN group. The rat model of PDPN was established by an intraperitoneal injection of streptozotocin (STZ). The DRG tissues from L4 to L6 were harvested from both groups (n=3 per group) for high-throughput sequencing of miRNAs and mRNAs. Bioinformatic analyses were performed to identify differentially expressed miRNAs (DEmiRs) and mRNAs (DEGs), followed by GO and KEGG enrichment analyses. An integrated miRNA-mRNA regulatory network was constructed. Preliminary validation was performed using RT-qPCR, with subsequent comparative analysis with relevant human-derived data.

A total of 11 significantly upregulated and 7 significantly downregulated DEmiRs (|log2FC| >1, P<0.05), along with 416 upregulated and 110 downregulated DEGs (|log2FC| >1, P<0.05), were identified. KEGG pathway analysis revealed that DEGs were significantly enriched in the pathways closely related to pain and diabetic metabolism (threshold P<0.05), such as neuroactive ligand-receptor interaction and lipid metabolism. Through construction of the miRNA-mRNA regulatory network, the results indicated that Ms4a2, Itgax, Wnt3, Tnn, and their upstream miRNAs may serve as core hubs regulating PDPN progression.

This study provides an initial systematic depiction of the miRNA-mRNA interaction network in the DRG of a PDPN model, demonstrating that Ms4a2, Itgax, Wnt3, Tnn, and their upstream miRNAs may modulate nutrient-sensing mechanisms involved in PDPN progression. Multiple potential therapeutic targets for PDPN are identified, including let-7i-5p, miR-9a-5p, miR-543-5p, miR-199a-5p, miR-324-5p, miR-702-3p, Ikzf3, Klhl6, Igsf6, Tmc8, Tmc1, Lmx1a, Cldn16, Vwc2, and Cyp2c23. Importantly, sphingolipid metabolism is regarded as a key pathway likely connecting metabolic alterations to the development of PDPN. Our work preliminarily explores the nutrient-sensing mechanisms underlying PDPN progression from a novel perspective.