Fig. 8

Effects of interleukin-6 (IL-6) on aquaporin-4 (AQP4) expression in cultured spinal cord astrocytes. a Spinal cord astrocytes were exposed to exogenous IL-6 at 0, 0.1, 1, or 10 ng/ml. After 24 h exposure, the membrane and cytoplasmic AQP4 expression in spinal cord astrocytes were markedly increased in the IL-6 0.1 ng/ml group, IL-6 1 ng/ml group, and IL-6 10 ng/ml group. *P < 0.05 vs. 0 ng/ml group (three replicates). b IL-6 levels increased in the surrounding medium of the OGD/R group after 24 h of the reoxygenation process after OGD. In comparison, this increase was significantly reduced in the OGD/R + HMGB1 shRNA group. *P < 0.05 vs. OGD/R group (three replicates). c The effects of astrocyte conditioned medium (ACM) on AQP4 expression in cultured spinal cord astrocytes. Twenty-four hours exposure of spinal cord astrocytes to the ACM obtained from the OGD/R group significantly increased the membrane and cytoplasmic AQP4 expression when compared with astrocytes incubated with the ACM obtained from the OGD/R + HMGB1 shRNA group. *P < 0.05 vs. astrocytes + OGD6h/R24h ACM group (three replicates). d Western blot analysis showed that the neutralizing anti-rat-IL-6 antibody could significantly reverse the upregulation effect of exogenous IL-6 or OGD/R ACM containing increased IL-6 on AQP4 expression in cultured spinal cord astrocytes. #P < 0.05 vs. astrocytes + IL-6 group; *P < 0.05 vs. astrocytes + OGD6h/R24h ACM group (three replicates)