Title: Sex-specific early growth hormone responses in mouse liver (Mus musculus)

Accession Number: GSE17644

Link to Dataset: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE17644

Repository: Gene Expression Omnibus (GEO)

Data Type(s): Gene Expression

Experiment Type(s): Expression profiling by array

Organism(s): Mus musculus

Summary: Sex differences in liver gene expression are dictated by sex-differences in circulating growth hormone (GH) profiles. Presently, the pituitary hormone dependence of mouse liver gene expression was investigated on a global scale to discover sex-specific early GH response genes that might contribute to sex-specific regulation of downstream GH targets and to ascertain whether intrinsic sex-differences characterize hepatic responses to plasma GH stimulation. RNA expression analysis using 41,000-feature microarrays revealed two distinct classes of sex-specific mouse liver genes: genes subject to positive regulation (class-I) and genes subject to negative regulation by pituitary hormones (class-II). Genes activated or repressed in hypophysectomized (Hypox) mouse liver within 30-90min of GH pulse treatment at a physiological dose were identified as direct targets of GH action (early response genes). Intrinsic sex-differences in the GH responsiveness of a subset of these early response genes were observed. Notably, 45 male-specific genes, including five encoding transcriptional regulators that may mediate downstream sex-specific transcriptional responses, were rapidly induced by GH (within 30min) in Hypox male but not Hypox female mouse liver. The early GH response genes were enriched in 29 male-specific targets of the transcription factor Mef2, whose activation in hepatic stellate cells is associated with liver fibrosis leading to hepatocellular carcinoma, a male-predominant disease. Thus, the rapid activation by GH pulses of certain sex-specific genes is modulated by intrinsic sex-specific factors, which may be associated with prior hormone exposure (epigenetic mechanisms) or genetic factors that are pituitary-independent, and could contribute to sex-differences in predisposition to liver cancer or other hepatic pathophysiologies.

Publication(s) associated with this dataset:

• Wauthier V, Sugathan A, Meyer RD, Dombkowski AA, Waxman DJ. 2010. Intrinsic Sex Differences in the Early Growth Hormone Responsiveness of Sex-Specific Genes in Mouse Liver. Mol Endocrinol 24(3):667-668. doi:10.1210/me.2009-0454 PMID:20150183 PMCID:PMC2840812

Project(s) associated with this dataset:

• Boston University: Training Core