For microarray analysis, six rats were used for each group for microarray study. Total RNA was isolated from lung tissues of six rats from each of the three experimental groups by TRIzol reagent (Thermo Fisher Scientific, Waltham, MA, USA) and purified using a Qiagen RNeasy Micro Kit (Qiagen NV, Venlo, the Netherlands). RNA integrity was checked using standard agarose gel electrophoresis and ethidium bromide staining.
Purified RNA was polymerase chain reaction amplified using a First Strand cDNA Synthesis Kit (Hoffman-La Roche Ltd., Basel, Switzerland) and labeled using an Agilent Quick Amp Kit (Agilent Technologies, Santa Clara, CA, USA). Then, RNA was hybridized with Agilent Whole Rat Genome Oligo Microarray (4×44 K) and washed. Finally, the slides were analyzed using an Agilent DNA microarray scanner (part number G2505B).
The raw microarray data were further analyzed using Agilent GeneSpring GX software Version 11.0. Processed data were subsequently filtered for significant detection (Student’s t-test screening, P<0.05) and differential expression versus COPD model rats (fold change, |log ratio| >1).
Purified RNA was polymerase chain reaction amplified using a First Strand cDNA Synthesis Kit (Hoffman-La Roche Ltd., Basel, Switzerland) and labeled using an Agilent Quick Amp Kit (Agilent Technologies, Santa Clara, CA, USA). Then, RNA was hybridized with Agilent Whole Rat Genome Oligo Microarray (4×44 K) and washed. Finally, the slides were analyzed using an Agilent DNA microarray scanner (part number G2505B).
The raw microarray data were further analyzed using Agilent GeneSpring GX software Version 11.0. Processed data were subsequently filtered for significant detection (Student’s t-test screening, P<0.05) and differential expression versus COPD model rats (fold change, |log ratio| >1).