Differentially expressed genes during disuse atrophy.. Mus musculus

To identify atrophy genes directly targeted by Bcl-3 transactivator at a genome wide level, we performed whole transcript expression array and ChIP-seq for muscles from weight bearing or 5-day hind limb unloaded mice. Genes that showed increased expression with unloading and a Bcl-3 peak in the promoter (from ChIP-seq data) were considered as Bcl-3 direct targets during disuse atrophy. Using ChIP array, we identified 241 direct targets for Bcl-3. Our data describe Bcl-3 as a global regulator both of the proteolysis and the change in energy metabolism that are essential components of muscle atrophy due to disuse. Overall design: Disuse skeletal muscle atrophy was induced by hind limb unloading. Weight bearing (WB) or 5-day hind limb unloaded (HU) muscles were harvested for total RNA isolation and processed for whole transcript expression profiling. We chose to examine gene expression and Bcl-3 binding from 5-day unloaded muscles because our previous time course study of disuse atrophy suggested that most genes are differentially regulated at this time point, and thus, would best represent the time for Bcl-3 binding to the gene targets of the NF-kB transcriptional network.