Total RNA was extracted using Trizol Reagent (Invitrogen) and reverse-transcribed into cDNA using PrimeScript RT Master Mix (TaKaRa). Real-time PCR was performed using the TB Green Premix Ex Taq II system (TaKaRa) with an Applied Biosystem 7500 instrument (Applied Biosystems).21 (link) Primer sequences were listed in online supplemental table 1. Relative expression to β-actin was determined using the ∆∆Ct method.