Microdissected kidneys were submerged in RNAlater (Qiagen), then homogenized using micropestele (Avantor #211-2100). Total RNA was purified by RNeasy mini kit (Qiagen) according to manufacturer's instructions. Quantification and quality control were done by Bioanalyzer (now Agilent) followed by Illumina TruSeq library preparation and sequencing with Illumina Hiseq2500.