BioProject

To investigate the specific role of PGC-1 coactivators in brown fat cells, we generated immortal preadipocyte lines from the brown adipose tissue of mice lacking PGC-1alpha. More...

To investigate the specific role of PGC-1 coactivators in brown fat cells, we generated immortal preadipocyte lines from the brown adipose tissue of mice lacking PGC-1alpha. We could then efficiently knockdown PGC-1beta expression by shRNA expression. Loss of PGC-1alpha did not alter brown fat differentiation but severly reduced the induction of thermogenic genes. In order to assess the specific requirement for PGC-1α in the global transcriptional response to cAMP, we used Affymetrix arrays to compare the sets of genes induced in response to a 4 hr dbcAMP treatment in differentiated wt and KO cells. This analysis revealed that 88 genes were induced more than 3-fold in the wt cells; of these, 54 (61% of total) were similarly increased in both wt and KO. However, 28 genes (32% of total) were decreased by at least 50% in the KO cells compared to wt cells. These data were confirmed by quantitative PCR for a subset of genes. These data indicate that PGC-1α is required for proper expression of approximately one third of the genes induced in response to cAMP in brown fat cells, but this set of sensitive genes is enriched in those involved in adaptative thermogenesis. Keywords: thermogenic gene program Overall design: WT and PGC-1alpha KO brown preadipocytes were differentiated into mature brown adipocytes for seven days. Cells were then treated with dibutyryl cAMP for four hours. Two replicates were made for each condition: WT non treated, WT treated with cAMP, KO non treated, KO treated with cAMP. Less...