Figure 7.

Ca²⁺ overload related to NF-κB activation and proinflammatory cytokines secretion induced by Cr(VI). The L02 cells were pretreated with BAPTA-AM prior to Cr(VI) treatment for 4 weeks. (a) The cytoplasmic and mitochondrial Ca²⁺ concentration was determined by spectrofluorometry. (b) β-Galactosidase Staining Kit (200x) (the percentage of senescent cells was showed in bar graph) and (c) DAPI staining were used to detect SAHF (200x). (d) The secretion of IL-6 and FGF23 were assayed by ELISA kit. (e) The protein levels of p65 (cytoplasm and nucleus) and (f) IκBα and IKKα were determined by Western blot. ImageJ software was used to analyze the relative levels of proteins normalized to the expression of GAPDH. All experiments were repeated at least 3 times and expressed as mean ± SD. ^∗p < 0.05, compared with control; ^#p < 0.05, compared with Cr(VI)-exposed group. For the sake of clarity, the same control GAPDH was applied to compare with all experimentally relevant proteins with the same exposure time detected on the same SDS-PAGE gel unless otherwise stated.