Sex-dependent gene expression patterns in control and Rspo1 gain-of-function mouse adrenals

Purpose: Ectopic Rspo1 expression in the mouse adrenal gland (driven by Sf1-Cre) leads to a sexually dimorphic phenotype of adrenocortical hyperplasia and tissue degeneration. In order to gain a mechanistic understanding of the sexual dimorphism, we compared the gene expression profiles of Rspo1-overexpressing animals (Rspo1 GOF) with control littermates. Methods: Total RNA was extracted from whole adrenals of male and female, control and Rspo1GOF mice during puberty (4 weeks). mRNA sequencing and differential gene expression analysis was conducted by Novogene Co. Hierarchical clustering and principal component analysis were conducted using Phantasus. Gene set enrichment analysis was performed using Broad's institute GSEA and the Molecular Signatures database. Conclusions: After Rspo1 transgene expression, sex is the second most important component that explains variability among the experimental groups. Genes specifically upregulated in female Rspo1GOF adrenals vs all the other groups are enriched in DNA proliferation and cell cycle genes, targets of E2F transcription factros and the DREAM complex. Genes specifically upregulated in male Rspo1GOF adrenals are related to immune system regulation. Verification of the RNA Seq results by experimental methods has showed that ectopic proliferation in the mutant adrenals is female-specific and that androgen receptor signalling plays a role in proliferation arrest in male animals. Moreover, accumulation of abnormal foamy-like macrophages in the male adrenals leads to tissue degeneration. We provide expression data for four groups: male control, female control, male Rspo1GOF, female Rspo1GOF. We analysed 4 biological replicates (individual mice) for each group.