See online expanded experimental procedures in the Supporting Materials. Groups of data are presented as mean ± standard error. We performed statistical comparisons with the unpaired two-tailed Student’s t test. A value of P < 0.05 was considered statistically

significant. We examined PXD101 supplier the 24-hour rhythm of BAF60a mRNA and protein levels in various mouse tissues. As shown in Fig. 1A, hepatic BAF60a mRNA levels had a diurnal rhythm that peaks at ZT21 (ZT0 is the onset at hour 0 of subjective light period), gradually declined thereafter, and reached a nadir at ZT13. The rhythmic expression pattern of BAF60a coincided with that of Bmal1, an important regulator in the clock machinery (Fig. 1A). A similar profile was also observed in epididymal fat tissue, but not in skeletal

muscle, heart, and kidney. Immunoblotting analyses indicated that BAF60a protein expression was significantly higher at ZT21 and ZT1 than other timepoints, consistent with the oscillation of the mRNA (Fig. 1B). Interestingly, other protein subunits of SWI/SNF complex such as Brg-1, Brm, Ini1, and BAF155 did not show a marked circadian expression at the transcriptional or translational level (Supporting Fig. 1; Fig. 1B). To determine whether the oscillation of BAF60a expression was controlled by an endogenous clock, we analyzed BAF60a mRNA expression in the livers of mice kept in constant darkness. Moderate amplitude oscillation of the BGJ398 research buy BAF60a mRNA was observed under these conditions, as in the LD cycle (Fig. 1C). In addition,

the expression of BAF60a homologs, including BAF60b and selleck chemicals BAF60c, also showed mild circadian rhythms in liver (Supporting Fig. 1). To investigate the nonredundancy of BAF60a in maintenance of the clock network, we next transduced C57/Bl6J mice through tail veins with adenoviruses expressing random or shRNA directed toward BAF60a. As expected, the expression levels of BAF60a were successfully down-regulated by adenoviruses at all examined timepoints (Fig. 2A). Knockdown of BAF60a in the liver significantly disrupted rhythmic expression patterns of clock genes including Bmal1, Per1, Per2, Rev-erbα, and Cry1 (Fig. 2A), as well as genes involved in key metabolic pathways including gluconeogenesis (G6Pase and PEPCK), glucose oxidation (PDK4), fatty acid β-oxidation (Cpt1a and Acox1), and mitochondrial respiration(Aco2 and Cox4a) (Fig. 2B). Notably, the expression levels of some of the examined clock components were lower than controls, whereas their expression pattern (oscillations) seemed to remain intact, suggesting that BAF60a dominantly affects the amplitude rather than the phase. On the other hand, the rhythmic expression pattern of other clock genes (Clock and Cry2) and lipogenic genes (ApoB and FAS), as well as PGC-1α, was not altered, indicating that BAF60a exerts specific effects on the downstream targets (Fig. 2B; Supporting Fig. 2). We also compared postprandial values for blood metabolic parameters in these animals.