Fig. 4. ADK inhibitor and A3AR agonist attenuate morphine-induced NLRP3 inflammasome activation and neuroinflammation. When compared with saline-infused rats, the expression of NLRP3 (A), cleaved caspase 1 (B), and IL-1β and TNF (C) increased by day 6 in the spinal cords harvested from rats morphine infusion. Daily intrathecal ABT-702 (30 nmol/day), but not its vehicle, attenuated these events (A–C) and increased IL-10 (C). Inhibition of A3AR signaling with MRS1523 (1 nmol/day) abrogated the effects of ABT-702 (A–C). Oral administration of MRS5698 (0.3 mg/kg per day) attenuated morphine-induced NLRP3 (D), cleaved caspase 1 (E), and IL-1β and TNF (F) and increased IL-10 expression (F). The vehicle used for the A3AR agonist was 10% DMSO in 0.5% methylcellulose. Results are mean ± S.D. and analyzed by two-tailed, one-way ANOVA with Dunnett’s comparisons. (A) F(3,20) = 308, P = 6.8 × 10−17, η2 = 0.98, n = 6/group; (B) F(3,20) = 355, P = 1.7 × 10−17, η2 = 0.98, n = 6/group; (C) IL-1β - F(3,8) = 52, P = 1.3 × 10−5, η2 = 0.95, n = 3/group; TNF: F(3,8) = 13, P = 0.0017, η2 = 0.83, n = 3/group; IL-10: F(3,8) = 34, P = 6.9 × 10−5, η2 = 0.95, n = 3/group; (D) F(2,15) = 179, P = 3.5 × 10−11, η2 = 0.96, n = 6/group; (E) F(2,15) = 158, P = 8.3 × 10−11, η2 = 0.95, n = 6/group; (F) IL-1β: F(2,12) = 66, P = 3.3 × 10−7, η2 = 0.92, n = 5/group; TNF: F(2,12) = 29, P = 2.5 × 10−5, η2 = 0.83, n = 5/group; IL-10: F(2,12) = 40, P = 64.9 × 10−6, η2 = 0.95, n = 5/group. *P < 0.05 vs. Veh + Sal; †P < 0.05 vs. Veh + Mor; §P < 0.05 vs. ABT-702 + Mor. GAPDH, glyceraldehyde-3-phosphate dehydrogenase; Mor, morphine; Sal, saline; Veh, vehicle.