Gene expression profiling (RNA-seq with partial depletion of rRNA) of livers of hypophysectomized male mice treated with a single pulse of growth hormone (GH)

We investigated the effects of a single pulse of growth hormone on the transcriptional activation of STAT5 target genes in hypophysectomized male mouse liver. This GEO series is part of a larger study, where we investigated the impact of a single pulse of GH given to hypophysectomized mice on local liver chromatin accessibility [DNase hypersensitive site analysis], transcription rates [hnRNA analysis], and gene expression [quantitative PCR and RNA-Seq] determined 30, 90 or 240 min later. The STAT5-dependent but sex-independent early GH response genes Igf1 and Cish showed rapid, GH pulse-induced increases in chromatin accessibility and gene transcription, reversing the effects of hypophysectomy. Rapid increases in liver chromatin accessibility and transcriptional activity were also induced in hypophysectomized male mice for some (Ces2b, Ugt2b38) but not for other liver STAT5-dependent male-biased genes (Cyp7b1). Moreover, in pituitary-intact male mice, Igf1, Cish, Ces2b and Ugt2b38 all showed remarkable cycles of chromatin opening and closing, and associated cycles of induced gene transcription, which closely followed each endogenous pulse of liver STAT5 activity. Thus, the endogenous rhythms of male plasma GH pulsation dynamically open and then close liver chromatin at discrete, localized regulatory sites in temporal association with transcriptional activation of Igf1, Cish and a subset of STAT5-dependent male-biased genes. Overall design: Liver RNA was isolated from hypophysectomized male mice that were untreated, or were treated with a single pulse of GH and euthanized 30, 90 or 240 minutes later. 8 Individual RNA samples were pooled to make 2 biological replicates per condition for RNA-seq analysis.

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Connerney J, Lau-Corona D, Rampersaud A, Waxman DJ