ABSTRACT
Objective To evaluate the role of suppressor of cytokine signaling 3 ( SOCS3) in the spinal cord of chronic sciatic constriction injury ( CCI) mice. Methods Part one:four Kunming mice were selected to receive the CCI operation by sciatic nerve ligation. Seven days after operation the mice were sac-rificed and L4～6 segments of the spinal cord were removed. The co-expression of SOCS3 with NeuN ( for neurons),GFAP (for astrocytes),or IBA1 (for microglia) in spinal were detected by immunohistofluores-cence. Part two:thirty-two Kunming mice were divided into 4 groups according to random number table:sham operation group (group SH),CCI group (group BP),CCI+Lenti-SOCS3 group (group BS),CCI +Lenti-vector group (group BV). Group BS were intrathcal injected of Lenti-SOCS3 (2 μl) and group BV were intrathcal injected of Lenti-vector (2 μl) on 7 d,8 d,9 d after operation. Paw withdrawal latency ( PWL) and paw withdrawal threshold ( PWT) were measured at 1 d before operation and 5,7,10,12,14 d after operation. Mice were then sacrificed and L4～6 segments of the spinal cord were removed for determina-tion of GFAP,IBA-1 by Western blot and IL-6,IL-1β,TNF-α by Elisa on 14 d. Results SOCS3 was dis-tributed in dorsal horn,and expressed in astrocytes and microglia,but hardly colocalized with neurons. Com-pared with group SH,the PWL and PWT of group BP and BV were significantly decreased after operation (all P<0. 05),and the expression of GFAP,IBA-1,IL-6,IL-1β and TNF-α was significantly increased (all P<0. 05). Compared with group BV,the PWL (5. 1±0. 9,7. 5±0. 8,7. 2±1. 4) and PWT (6. 1±1. 4,8. 9± 1. 1,8. 2±2. 1) of group BS was significantly increased on 10,12,14 d (all P<0. 05),and the expression of GFAP (1. 69±0. 45),IBA-1(1. 76±0. 25),IL-6 (181±8),IL-1β (151±7),TNF-α (216±9) was signifi-cantly downregulated (P<0. 05) . Conclusion SOCS3 alleviates neuropathic pain by inhibiting the glial ac-tivation and the expression of proinflammatory cytokines IL-6,IL-1β,TNF-α.