| Summary |
The purpose of this study is to investigate the role of SIRT1 in high-fat diet-induced liver steatosis and insulin resistance. SIRT1 is a nuclear enzyme that could remove an acetyl-group from target proteins by using NAD as co-substrate. Homologs of this protein in yeast and the roundworm C. elegans are able to delay the aging process in response to nutrients. However, the molecular mechanism by which SIRT1 sense the environment to mediate this response are poorly understood. We have shown that when chronically fed with a 40%-fat diet, SIRT1 heterozygous animals gain significantly more weight compared to wild type littermates. They are also hyperinsulimia, more insulin-resistant, and accumulate more lipids in liver. Interestingly, these animals also show signs of premature aging, such as an early appearance of gray fur, defective motor activity, and decreased fertility. In this microarray study, we analyzed the gene expression profiles in the liver of WT low-fat diet, Het low-fat diet, WT high-fat diet, and Het high-fat diet using Agilent Whole Genome Mouse 4x44 multiplex format oligo arrays following the Agilent-1-color microarray-based gene expression analysis protocol. This microarray analysis concluded that SIRT1 Het mice reponsed to the high-fat diet differently from the WT control mice. |
