RNA isolation and microarray profiling

Liver tissues were thawed and homogenized on ice in TRIzol (Invitrogen; Thermo Fisher Scientific, Inc., Waltham, MA, USA) and total RNA was extracted using the TRIzol kit (cat. no. 15596-026; Invitrogen; Thermo Fisher Scientific, Inc.), according to the manufacturer's protocol. Concentration and purity of RNA were determined using the ASP-3700 spectrophotometer (ACT Gene, Inc., Piscataway, NJ, USA).

Whole-genome expression profiling was performed using Agilent mouse 4×44 K microarrays (Kang Chen Bio-Tech, Inc., Shanghai, China). Briefly, RNA samples were amplified and labeled with the Agilent One-Color RNA Spike-In Kit (cat. no. 5188-5282; Agilent Technologies, Inc., Santa Clara, CA, USA), and cRNA was hybridized to the arrays in the Agilent Hybridization Chamber (Agilent Technologies, Inc.). Hybridization and washing were performed with the Gene Expression Wash Buffer kit (cat. no. 5188-5327; Agilent Technologies, Inc.), and arrays were scanned with the GenePix 4000B microarray scanner (Molecular Devices LLC, Sunnyvale, CA, USA). Image analysis for grid alignment and the expression data was performed with Nimble Scan software (version 2.5; Roche NimbleGen, Inc., Madison, WI, USA). Volcano plots (GeneSpring Software, version 7.2; Aligent Technologies, Inc.) were used to analyze the raw data files.