Diabetic neuropathic pain (DNP) is one of the most common chronic peripheral neuropathies in diabetes mellitus (DM). Objective. To observe the underlying mechanism of the effects of Yiqi Huoxue Tongluo Decoction (YQHX) on DNP rats. Methods. SD rats were intraperitoneally injected with 35 mg/kg streptozotocin (STZ) to prepare DNP models and were treated with YQHX for 8 weeks. Results. Studies have shown that the drug restores some levels of MWT, TWL, and MNCV, downregulates the levels of inflammatory factors IL-6, IL-1β, and TNF-α, downregulates the levels of ASK1-MKK3-p38, and weakens the level of OX42 activation. Conclusion. Yiqi Huoxue Tongluo Decoction can relieve DNP by affecting the activity of spinal cord microglia and the ASK1-MKK3-p38 signaling pathway, thereby reducing the central sensitization caused by the inflammatory response of DNP rats.

Diabetic neuropathy (DN) is one of the chronic complications of diabetes which can cause severe harm to patients. In order to determine the key genes and pathways related to the pathogenesis of DN, we downloaded the microarray data set GSE27382 from Gene Expression Omnibus (GEO) and adopted bioinformatics methods for comprehensive analysis, including functional enrichment, construction of PPI networks, central genes screening, TFs-target interaction analysis, and evaluation of immune infiltration characteristics. Finally, we examined quantitative real- time PCR (qPCR) to validate the expression of hub genes. A total of 318 differentially expressed genes (DEGs) were identified, among which 125 upregulated DEGs were enriched in the mitotic nuclear division, extracellular region, immunoglobulin receptor binding, and p53 signaling pathway, while 193 downregulated DEGs were enriched in ion transport, membrane, synapse, sodium channel activity, and retrograde endocannabinoid signaling. GSEA plots showed that condensed nuclear chromosome kinetochore were the most significant enriched gene set positively correlated with the DN group. Importantly, we identified five central genes (Birc5, Bub1, Cdk1, Ccnb2, and Ccnb1), and KEGG pathway analysis showed that the five hub genes were focused on progesterone-mediated oocyte maturation, cell cycle, and p53 signaling pathway. The proportion of immune cells from DN tissue and normal group showed significant individual differences. In DN samples, T cells CD4 memory resting and dendritic cells resting accounted for a higher proportion, and macrophage M2 accounted for a lower proportion. In addition, all five central genes showed consistent correlation with immune cell infiltration levels. qPCR showed the same expression trend of five central genes as in our analysis. Our research identified key genes related to differential genes and immune infiltration related to the pathogenesis of DN and provided new diagnostic and potential therapeutic targets for DN.

Object: Exploring the effect of Tetrahydropalmatine (THP) on diabetic neuropathic pain (DNP) and its possible mechanism. Methods: The type 2 diabetic (T2DM) rat models were prepared by high-fat and high-sugar feeding combined with a single small-dose intraperitoneal injection of streptozotocin (STZ). When the mechanical withdrawal threshold (MWT) and the thermal withdrawal latency (TWL) of T2DM model rats decreased to less than 85% which were judged as DNP-bearing rats. After treatment with or without THP, the protein expression of hypertonic glycerol reactive kinase (p38), phosphorylated hypertonic glycerol-responsive kinase (p-p38) and OX42 (a specific marker of microglia) were detected by Western Blot and and the mRNA content of p38 and OX42 were detected by qRT-PCR. The expression of pro-inflammatory factors IL-1β, IL-6, TNF-α, as well as chemotactic factors and their receptors including CXCL1, CXCR2, CCL2 and CCR2 in spinal tissues were detected by ELISA. Serum FINS and GSP content were also detected by ELISA. Double-label immunofluorescence were used to observe the expression of OX42 and p-p38 in the spinal dorsal horn. Results: Results showed that THP inhibited microglial activation of spinal in DNP rats. And after THP intervention, the MWT and TWL of DNP rats decreased, the expression of p38, p-p38 and OX42 in the spinal cord tissues of rats was significantly reduced while the mRNA of p38 and OX42 also reduced. The expression of IL-1β, IL-6, TNF-α, CXCL1, CXCR2, CCL2 and CCR2 in the spinal cord tissues of rats was significantly reduced (P < 0.01). At the same time, THP significantly proved FINS, but did not affect FBG and GSP in DNP rats. Conclusions: THP significantly alleviates pain symptoms in DNP rats, and this effect may be achieved by inhibiting the inflammatory response caused by the activation of microglia mediated by the p38-MAPK signaling pathway.