Differential expression of ciliary neurotrophic factor receptor in skeletal muscle of chick and rat after nerve injury.
The activities of ciliary neurotrophic factor (CNTF) were initially thought to be restricted to cells in the nervous system. However, the recent identification of its receptor specificity-conferring alpha component (CNTFR alpha) in skeletal muscle has provided the clue to the unexpected actions of CNTF in the periphery. In the present study, we demonstrated that the mRNA expression of CNTFR alpha in chick skeletal muscle was decreased by approximately 10-fold after nerve transection; this finding is in sharp contrast to the dramatic up-regulation observed in denervated rat muscle. As a first step toward investigating the differential regulation of CNTFR alpha in chick and rat, we examined the mRNA expression of CNTFR alpha in different types of muscle following nerve injury in young and adult animals. Our findings demonstrated that the differential expression of CNTFR alpha observed in denervated skeletal muscle of the chick and rat was not dependent on age or muscle type. The temporal profile of the changes in CNTFR alpha expression was, however, dependent on the age of the chick as well as the types of muscles. Furthermore, the low level of CNTFR alpha expression observed in denervated chick muscle recovered to almost control levels in regenerating skeletal muscle. Taken together, our findings provided the first extensive analysis on the mRNA expression of CNTFR alpha and the alpha subunit of the acetylcholine receptor in various skeletal muscles of the chick following nerve injury and regeneration.
Ip
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Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Fu
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Tsim
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Ip
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D000375:Aging / Q000502:physiology*; D000818:Animals; D015152:Blotting, Northern; D002645:Chickens; D015536:Down-Regulation; D009121:Muscle Denervation; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development / Q000294:innervation* / Q000378:metabolism*; D009409:Nerve Crush; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification; D051381:Rats; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis*; D012038:Regeneration; D012584:Sciatic Nerve / Q000254:growth & development / Q000502:physiology*; D014158:Transcription, Genetic
D012333:RNA, Messenger; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor