Beta-adrenergically stimulated RNA expression in Syk deficient brown adipocytes

Cre recombinase activity was induced in differentiating brown adipocytes from CreERT2 Sykflox/flox mice in vitro, which resulted in a partial loss of Syk protein in mature brown adipocytes. Such cells were viable, morphologically normal and displayed largely normal gene expression as indicated by mRNA sequencing and qPCR analysis, suggesting that Syk is not required for survival and gene expression of terminally differentiated brown adipocytes. mRNA sequencing of Syk depleted brown adipocytes treated with 0.1 microM isoproterenol for 6 h showed that 2460 genes were not induced or suppressed upon stimulation. Gene set enrichment analysis revealed a great enrichment for genes essential for mitochondrial respiration and biogenesis, for genes associated with and required for adipogenesis, as well as for genes responsive to various stimuli in adipocytes among genes highly ranked by reduced fold changes in response to isoproterenol in the Syk deficient brown adipocytes. Poly A+ RNA sequencing (TrueSeqStrandedPolyA) was performed on RNA samples from in vitro tamoxifen treated day 8 brown adipocytes derived from UBC-CreERT2 Sykflox/flox and Sykflox/flox mice 6 h following stimulation with 0.1 μM isoproterenol in serum free medium and from unstimulated controls using a Illumina HiSeq genome sequencer.