Fig. 3

Inhibiting GPER expression in the DRG and SDH alleviates spared nerve injury (SNI)-induced pain behaviours in rats and simultaneously restores GABAα2 expression. A, B The oestrogen receptor-α antagonist (MPP; 1 ng/μl, 1 μl) or the G protein-coupled oestrogen receptor antagonist (G15; 1.8 μg/μl, 1 μl) oestrogen receptor-β antagonist (PHTPP; 1 ng/μl, 1 μl) was intrathecally injected into the subarachnoid space of SNI rats on Day 5 to detect mechanical allodynia and cold hyperalgesia. ^***p < 0.001 versus vehicle (10% dimethyl sulfoxide; Kruskal–Wallis test followed by Dunn’s multiple comparison test). C Quantification of the mRNA content of GABA receptor subunits in the DRG defined. Error bars in all panels represent S.E.M. (n = 3, one-way ANOVA. ^***p < 0.001 versus Sham; ^###p < 0.001 versus SNI). D Intrathecal injection of the G protein-coupled oestrogen receptor-1 antagonist (G15; 1.8 μg/μl, 1 μl) into the subarachnoid space of SNI rats on day5 to detect mRNA content of oestrogen receptor-α, oestrogen receptor-β, and G protein-coupled oestrogen receptor in the DRG (n = 3, one-way ANOVA. ^***p < 0.01 versus Sham; ^#p < 0.05, ^##p < 0.01 versus SNI). E, F Western blot images and quantification for GPER, ERα, ERβ, and GABAα2 in the DRG after sham, SNI and intrathecal injection of G15 of rats. (n = 3, one-way ANOVA. ^***p < 0.001 versus Sham; ^###p < 0.001 versus SNI). G Immunofluorescence coexpression of GPER and GABAα2 in the dorsal root ganglia of rats on Day 5 after SNI. Scale bars = 50 μm, n = 6