Perfluorooctane sulfonate mediates secretion of IL-1β through PI3K/AKT NF-кB pathway in astrocytes

Abstract

Perfluorooctane sulfonate (PFOS) is a persistent and bioaccumulative compound that has been widely used in various fields of life and industrial productions, because of its special chemical and physical properties. Numerous studies have indicated significant neurotoxic effect of PFOS, especially on neurons and microglia. However, the influence of PFOS on astrocyte physiology remains unclear. In this study, we showed that PFOS triggered reactive astrocytosis in time- and dose-dependent manners. The low-doses of PFOS increased the cell number and the expression of glial fibrillary acidic protein (GFAP), a well-known hallmark of reactive astrocytes, in C6 astrocyte cells. ELISA and RT-PCR analysis showed that PFOS promoted the expression and secretion of Interleukin-1 beta (IL-1β) in dose- and time-dependent manners. Furthermore, PFOS exposure could induce the phosphorylation and degradation of IκBα, and the translocation of NF-κB p65 from the cytoplasm to the nucleus in C6 glioma cell line. Thus, the NF-кB signaling pathway can be activated after PFOS exposure. In addition, pretreatment with AKT inhibitor LY294002 could obviously attenuate PFOS-induced NF-κB activation and IL-1β secretion. Taken together, these results indicated that PFOS could facilitate reactive astrocytosis and the secretion of pro-inflammatory cytokines through AKT-dependent NF-κB signaling pathway.

Keywords: AKT; Astrocytes; IL-1β; NF-κB; Perfluorooctane sulfonate.