Regulation of miRNA-467b on TNF-α in painful diabetic neuropathy

Abstract

Objective To investigate the effect of miRNA-467b on the regulation of TNF-α in painful diabetic neuropathy. Methods Forty 8 week old male SD rats were divided into model group and blank group, with 20 rats in each groups. The model group was injected with streptozotocin for restruetion of painful diabetic neuropathy, and the blank control group were injected with sodium chloride injection. The model group was sudivided into experimental group and control group at 1 weeks after completion of modeling, with 10 rats in each group. The experimental group was injected with synthetic miRNA-467b, and the control group was injected with the same amount of sodium chloride injection. The neuropathic pain and the expression of miRNA-467b and TNF-α were detected in all rats. Results The latency of mechanical pain and thermal pain in the model group were lower than that in the blank group (P<0.05), and the latency of mechanical pain and thermal pain in the experimental group was also higher than that in the control group (P<0.05). The expression of miRNA-467b in the model group were lower than that in the blank group, and the TNF-α expression were increased, there were significant difference (P<0.05); and the miRNA-467b, TNF-α mRNA expression levels in the experimental group were significantly different compared with the control group (P<0.05). The expression of TNF-α protein in the experimental group was decreased, which was significantly different from that in the control group(P<0.05), and the expression of TNF-α protein in the model group was higher than that in the blank group (P<0.05). Conclusions The expression of miRNA-467b is down-regulated in painful diabetic neuropathy, and miRNA-467b can positively regulate the down- regulation of TNF-α and cause hyperalgesia. Key words: Mechanical pain; Heat pain; miRNA-467b; Diabetic neuropathy; TNF- alpha