SIRT1 dosage-dependent effects on cell proliferation and metabolism

The goal of this project is to understand the dosage-dependent effects of SIRT1, the most conserved mammalian NAD+-dependent protein deacetylase, on cell proliferation and metabolism. Our recent studies indicate that SIRT1 has a dosage-dependent effect on cell metabolism and proliferation. Heterozygous deletion of SIRT1 enhance glycolysis and glutaminolysis, thereby promoting cell proliferation and stress resistance. Yet homozygous deletion of SIRT1 triggers cellular apoptotic pathways, leading to increased cell death. To understand the molecular mechanisms underlying this dose-dependent effect, we examined the transcriptomes of SIRT1 WT, Het, and KO MEFs cultured in complete DMEM medium by microarray analysis. 4 groups of female WT, SIRT1 Het, and SIRT1 KO MEFs were cultured in complete medium and harvested in the log-growth phase.Total RNA was isolated using the Qiagen RNeasy mini-kit, and gene expression profiles were analyzed using Agilent Whole Mouse Genome 4x44 multiplex format oligo arrays (014868) (Agilent Technologies, Santa Clara, CA), following the Agilent 1-color microarray-based gene expression analysis protocol.