Propofol attenuates mast cell degranulation via inhibiting the miR-221/PI3K/Akt/[Ca.sup.2+] pathway

The aim of the present study was to investigate the effect of propofol on immunoglobulin (Ig)E-activated mast cell degranulation and explore the underlying mechanisms responsible. RBL-2H3 cells were treated with propofol for at a variety of concentrations and different amounts of time. Cell viability was assessed using an MTT assay and microRNA (miR)-221 expression was quantified using reverse transcription-quantitative polymerase chain reaction. RBL-2H3 cells were transfected with miR-221 mimic or a negative control and degranulation, including the release of [beta]-hexosaminidase and histamine, was evaluated using an ELISA kit. The effect of miR-221 overexpression on the phosphorylation of protein kinase B (Akt) was detected using western blotting and extracellular [Ca.sup.2+] influx was measured via afura-2 assay. The phosphoinositide 3-kinase(PI3K) inhibitor LY294002 was used to investigate the association between PI3K/Akt signaling and [Ca.sup.2+] influx in the presence of propofol. The results demonstrated that propofol treatment suppressed RBL-2H3 cell proliferation in a dose- and time-dependent manner. Propofol inhibited miR-221 expression in a dose-dependent manner compared with the control group; however, the inhibitive effect was significantly abrogated following transfection with miR-221 mimics. Furthermore, [beta]-hexosaminidase and histamine release, PI3K/Akt signaling and [Ca.sup.2+] influx were decreased following propofol application. miR-221 overexpression markedly ameliorated the suppressive effect of propofol. Treatment with LY294002 reversed the propofol-induced decrement of [Ca.sup.2+] influx on IgE-mediated RBL-2H3 cells, suggesting an association between PI3K/Akt signaling and [Ca.sup.2+] influx. In conclusion, the results of the present study suggest that propofol treatment attenuates mast cell degranulation via inhibiting the miR-221/PI3K/Akt/[Ca.sup.2+] pathway. These results indicate that propofol may have a potential therapeutic effect as a treatment for allergic diseases. Key words: propofol, RBL-2H3 cells, mast cell degranulation, microRNA-221, phosphoinositide 3-kinase/protein kinase B pathway, [Ca.sup.2+] influx