Ubiquitin gene expression in skeletal muscle is increased by tumour necrosis factor-alpha.

An acute intravenous administration of 100 micrograms/kg body weight of recombinant tumour necrosis factor-alpha resulted in a time-dependent increase in the levels of ubiquitin mRNAs in rat skeletal muscle. The results presented here, together with previous observations demonstrating that the cytokine increases the conjugation of proteins with ubiquitin in rat skeletal muscle (1), suggest that the ubiquitin system for non-lysosomal protein degradation could have a very important role in the mechanism triggered by tumour necrosis factor-alpha which is responsible for enhanced muscle proteolysis in sepsis and other pathological states.