Transcriptome analysis of fetal kidney RNA from GR-null and control mice at E18.5

Glucocorticoid steroid hormones play essential roles for maturation and growth of many fetal organs including the lung and heart, yet the kidney-specific roles are not well characterised. Glucocorticoids activate the intracellular glucocorticoid receptor (GR) that acts primarily as nuclear transcriptional regulators. We analysed the effect of loss of GR expression on the fetal kidney transcriptome at E18.5 by RNA sequencing. Total RNA was extracted from control (n=4) and GR-null (n=3) kidneys. Loss of GR expression resulted in 2473 differentially expressed genes (FDR < 0.05), 288 genes with absolute LogFC > 1 & FDR < 0.05, which identified 16 upregulated and 25 downregulated primary ciliary genes (FDR < 0.05). Primary cilia are cell signalling and environment sensing organelles that protrude from cell membranes and play important roles during embryogenesis and tissue homeostasis. Little is known of the cellular pathways regulating ciliogenesis. Our findings indicate a role of glucocorticoid signalling in primary cilia formation in renal tubular cells of the developing mouse kidney. Total RNA was isolated from embryonic kidneys using TRIzolTM reagent (Invitogen, USA) according to the manufacturer’s instructions. Total RNA was analysed using a Bioanalyzer 2100 (Agilent Technologies, USA) and Next generation RNA sequencing (NGS RNA-seq) was performed by Genewiz Biotechnology, Suzhou, China. RNA sequencing (20 million reads) was performed on the Illumina Hiseq platform, in a 2 x 150 bp paired-end format.