EP300 and muscle atrophy: In L6 muscle cells treated with dexamethasone (a commonly used in vitro model of muscle atrophy), the downregulation of p300 can reduce the acetylation of the transcription factors C/EBP, FOXO, and p65; decrease the expression of the ubiquitin ligase MuRF1; and reduce dexamethasone-induced muscular atrophy [149].