Identification and characterization of differentially expressed genes in denervated muscle

Denervation results in a series of changes in skeletal muscle. To elucidate the molecular basis underlying these changes, it is important to identify the profile of altered gene expression in skeletal muscle following nerve i njury. In the present study, we have examined the differentially expressed genes in denervated gastrocnemius muscle using RNA fingerprinting by arbitr arily primed PCR. Eight differentially expressed mRNA transcripts have been identified. A bilateral regulatory profile can be observed for the up-regu lated genes in both denervated and contralateral control muscle following u nilateral sciatic nerve injury. The temporal expression profiles of the den ervation-regulated genes in muscle during development, together with their dependency on nerve activity, suggest potential functional roles following nerve injury in vivo. In particular, the identification of two apoptosis-re lated genes in denervated muscle provides molecular evidence that the apopt otic process is likely to be involved in the intricate changes that lead to muscle atrophy. Our findings not only allow the identification of novel ge nes, but also suggest possible functions for some known genes in muscle fol lowing nerve injury. Taken together, these findings provide important insig hts into our understanding of the molecular events in denervated muscle and suggest that the differentially expressed genes may play potential roles d uring muscle denervation and regeneration.