Sexual Dimorphic Regulation of Liver Gene Expression by Glucocorticoids

ABSTRACT: Males and females exhibit differences in the incidence of many major diseases including auto-immune diseases, hepatocellular carcinoma, diabetes, and osteoporosis, which all have important inflammatory components in their etiology. Glucocorticoids are the primary physiological anti-inflammatory hormone in all mammals and synthetic derivatives of these hormones are widely prescribed as anti-inflammatory agents irrespective of gender. Surprisingly we report a marked sexually dimorphic regulation of gene expression by glucocorticoids in the rat liver. Eight distinct patterns of glucocorticoid regulated genes were identified and two revealed genes that respond to glucocorticoid treatment in both sexes in opposite directions (anti-correlated genes. We also identified gender-specific groups of genes regulated by glucocorticoids. Pathways analysis identified sex-specific glucocorticoid regulated gene expression in several canonical pathways that have been implicated in human disease in which disease susceptibility is sex-biased. For example, comparison of number of genes involved in inflammatory disorders between sexes, revealed 84 additional glucocorticoid responsive genes in the male rat. Our data suggests that glucocorticoids thorough sexually-dimorphic regulation of gene expression modulate gender specific homeostatic functions in male and female liver. Adult males and females adrenalectomized Sprague-Dawley rats (8-10 weeks of age) (females Distrous 1) were treated with vehicle (Phosphate Buffered Saline – 400 µl) or Dexamethasone (1mg/Kg i.p.) purchased from Steraloids (Newport, RI). Liver was harvested 6 hours after treatment and kept in RNA later solution at 4oC over night. Samples were frozen and stored at -80oC. Three replicate microarrays were completed for each group (male vehicle, male dexamethasone, female vehicle and female dexamethasone) for a total of 12 microarrays. Each microarray was hybridized using a pooled RNA sample, and each pool was created from equal amounts of total RNA from three independent RNA samples, representing individual animals (n=9 animals per group). This approach provides appropriate biological replication within the constraints of a limiting number of microarrays (C. Kendziorski, R. A. Irizarry, K. S. Chen, J. D. Haag, M. N. Gould, Proc Natl Acad Sci U S A 102, 4252 Mar 22, 2005).

ORGANISM(S): Rattus norvegicus

SUBMITTER: NIEHS Microarray Core 

PROVIDER: E-GEOD-13461 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress