Cystatin F involvement in adenosine A(2A) receptor-mediated neuroinflammation in BV2 microglial cells

Our previous studies have shown adenosine A(2A) R activation markedly promotes the expression of cystatin F (CF) and exacerbates the white matter lesions induced by hypoxic brain injuries. Thus, we hypothesized that CF was probably involved in neuroinflammation of activated microglia induced by A(2A) R activation. We transfected the BV2 cells with a CF shRNA vector and examined the production of pro-inflammatory cytokines in hypoxic-BV2 cells in which A(2A) R was activated or inactivated to confirm this hypothesis. Additionally, we also investigated the probable signaling pathways involved in modulation of A(2A) R activation on CF expression in hypoxia-activated BV2 cells. Activation of A(2A) R promoted CF expression, which was significantly increased after the low glucose and hypoxia treatments in BV2 cells. CF gene knockdown markedly inhibited the increase in the expression of pro-inflammatory cytokines induced by A(2A) R activation in hypoxic-BV2 cells. Furthermore, the increased expression of the CF induced by A(2A) R activation was remarkably inhibited in hypoxic-BV2 cells administrated with the PKA inhibitor H-89 and the PKC inhibitor staurosporine. Hence, these results indicate that hypoxia BV2 cells highly express CF, which is involved in A(2A) R activation-mediated neuroinflammation via the PKA/CREB and PKC/CREB or ERK1/2 signaling pathways.