Mechanisms of Akt3 gene knockout on neuropathic pain in mice with sciatic nerve ligation / 中华行为医学与脑科学杂志

ABSTRACT

Objective:To explore the mechanism of Akt3 gene knockout on neuropathic pain induced by sciatic nerve ligation.Methods:Twelve Akt3 knockout mice with SPF grade C57BL/6 mice as background were randomly divided into Akt3 gene knockout + Sham group (Akt3 -/-+ Sham, n=6)and Akt3 gene knockout + CCI group(Akt3 -/-+ CCI, n=6). Twelve wild type C57BL/6 mice were randomly divided into wild + Sham group (WT + Sham, n=6) and wild + CCI group (WT + CCI, n=6) by random number table. Chronic sciatic nerve ligation was used to make neuropathic pain model in CCI group, and sham group was subjected to sham operation. The paw withdrawal mechanical threshold (PWMT) was measured 1 day before operation and 7 days after CCI. Three mice were randomly killed in Sham group 7 days after modeling, and 3 mice in CCI group were killed at 7 days and 14 days respectively.The L3-5 spinal cord segment was taken. Akt3, phosphorylated Akt (p-Akt), GSK3β and phosphorylated NR2B (p-NR2B) were detected by Western blot. SPSS 21.0 software was used for statistical analysis. Results:Group time interaction effects of PWMT, the expression of protein Akt3, p-Akt, GSK3β, p-NR2B in spinal cord were significantly different ( F=16.667, 269.899, 26.651, 572.998, 37.836, P<0.01). Compared with the Akt3 -/-+ Sham group, the PWMT in Akt3 -/-+ CCI group was significantly lower((0.34±0.20)g, (1.18±0.11)g, P<0.01), and the expression of p-Akt((0.90±0.08), (0.51±0.06), P<0.01), GSK3β((0.74±0.04), (0.29±0.02), P<0.01) and p-NR2B((0.96±0.11), (0.71±0.04), P<0.05) in spinal cord increased. Compared with the WT+ CCI group, the PWMT of the Akt3 -/-+ CCI group was obviously lower((0.34±0.20)g , (0.49±0.12)g, P<0.05), and the expression of p-Akt((0.90±0.08), (1.02±0.17), P<0.05)decreased, and the expression of GSK3β((0.74±0.04), (0.57±0.09), P<0.01) and p-NR2B((0.96±0.11), (0.91±0.08), P<0.05) increased. Conclusion:After Akt3 gene knockout, the aggravation of neuropathic pain after sciatic nerve ligation may be related with the change of Akt/GSK3β/NR2B expression.