Fig. 2

GRK2 involved in EA analgesia and neuroinflammation reduction. A Experimental strategy for inhibiting spinal cord GRK2 expression by virus injection. B Western blot analysis showed that GRK2 protein expression was downregulated in the spinal dorsal horn of the mice 3 weeks after the virus administration. Results are normalized to GAPDH and shown as ratios to eGFP control group. Values are represented as mean ± SEM. *p < 0.05 versus eGFP control group. Student’s t test was used for comparisons. C Representative images of the expression of eGFP in the spinal cord at the third week after AAV administration to the spinal cord, scale bar = 100 μm. D Downregulation of GRK2 in the spinal cord eliminated the analgesic effect of EA in CFA-induced mechanical allodynia. Values are represented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001. The statistical method is two-way ANOVA multiple comparisons. E–G Real-time PCR analysis showed that the mRNA expression of CD16/32, iNOSIL-1β had no significant change. H–J Real-time PCR analysis showed the increase of the mRNA expression of CD206, IL-10, TGF-β by EA was inhibited by the downregulation of GRK2. Results are normalized to GAPDH mRNA. Values are represented as mean ± SEM. *p < 0.05. Student’s t test was used for comparisons