Transcriptome Profile of Rat Adrenal Evoked by Gonadectomy and Testosterone or Estradiol Replacement

Abstract

Sex differences in adrenal cortex structure and function are well known in different species. In the rat, they are manifested as larger adrenal cortex and higher corticosterone secretion by females compared with males. These sex differences depend, among others, on functioning of the hypothalamic-pituitary-adrenal axis (HPA). In this aspect, it is widely accepted that testosterone exerts an inhibitory and estradiol stimulatory effect on the said axis. The molecular bases of these sex-related differences are poorly understood. Therefore, we performed studies aimed to demonstrate the effect of testosterone and estradiol on the expression of differentially regulated genes in rat adrenal gland. The classical method applied in the study—gonadectomy and gonadal hormone replacement—allows obtaining results suggesting a physiological role of the tested hormone (testosterone or estradiol) in the regulation of the specific genes. Adult male and female rats were either gonadectomized or sham operated. Half of orchiectomized rats were replaced with testosterone while ovariectomized ones with estradiol. Transcriptome was identified by means of Affymetrix® Rat Gene 2.1 ST Array. Differentially expressed genes were analyzed by means of DAVID web-based bioinformatic tools and confirmed by means of Gene Set Enrichment Analysis. For selected genes, validation of the results was performed using QPCR. Performed experiments have provided unexpected results. Contrary to expectations, in orchiectomized rats, testosterone replacement stimulates expression of numerous genes, mainly those associated with lipids and cholesterol metabolism. However, in ovariectomized animals, estradiol replacement inhibits the expression of genes, mainly those involved in intracellular signaling pathways. The physiological relevance of these findings awaits further research.

PKA signaling drives reticularis differentiation and sexually dimorphic adrenal cortex renewal

“…In contrast to females, however, endocrine hyperactivity in castrated DAdKO males seemed less dependent on upregulation of de novo cholesterol synthesis genes. Although contribution of the mevalonate pathway remains to be functionally assessed, this was reminiscent of recent transcriptomic analyses in rat adrenals, suggesting that genes related to cholesterol homeostasis were more sensitive to hormonal regulation in females than in males (39). Altogether, these data establish that Prkar1a genetic ablation in the adult adrenocortical lineage leads to endocrine hyperactivity and conversion of inner zF into a reticularis-like zone, which is unrelated to the X-zone.…”

The effects of flutamide on the neonatal rat hypothalamic–pituitary–adrenal and gonadal axes in response to hypoxia

“…The main motivation for this study was our previous findings that neonatal stressors program the control of HPA axis, insulin and glucose, and other metabolic biomarkers in the adult rat in a sexually dimorphic manner (Gehrand et al, 2018(Gehrand et al, , 2016Raff et al, 2018). Based on the literature, we thought that stress-induced testosterone responses in the neonatal male rat could be responsible for this longterm programming (Boksa & Zhang, 2008;Brunton, 2015;Clarkson & Herbison, 2016;Jopek et al, 2017;Kasprzak & Lesniewska, 1986;Liu & Du, 2002;Slob, Ooms, & Vreeburg, 1980;Vega Matuszczyk, Silverin, & Larsson, 1990;Ward, Ward, Denning, French, & Hendricks, 2002). Flutamide has previously been used in the neonatal rat to modulate the effects of circulating androgens (McCormick & Mahoney, 1999;Ongaro, Castrogiovanni, Giovambattista, Gaillard, & Spinedi, 2011).…”

“…testosterone may be responsible for long-term, sexually dimorphic programming in male rats (Brunton, 2015;Jopek et al, 2017;Kasprzak & Lesniewska, 1986;Kitay, 1963aKitay, , 1963bSeale, Wood, Atkinson, Lightman, & Harbuz, 2005).…”

ZFP91 zinc finger protein expression pattern in normal tissues and cancers

“…Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. Analyses were performed as described earlier (14,(17)(18)(19). Briefly, primers were designed by Primer 3 software (Whitehead Institute for Biomedical Research, Cambridge, USA) and purchased from the Laboratory of DNA Sequencing and Oligonucleotide Synthesis (Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland).…”