Upregulation and redistribution of cadherins reveal specific glial and muscle cell phenotypes during wallerian degeneration and muscle denervation in the mouse.
In the present work, we investigated the expression of cadherin mRNAs in the adult neuromuscular system either under normal conditions or following experimental neurotomy. Cadherin-6, a marker of Schwann cell precursors, was not expressed in the adult peripheral nerve, while M-cadherin, cadherin-11, and N-cadherin were expressed both by glial and conjunctive cells. Moreover, the three transcripts were transiently upregulated in the distal stump of neurotomized sciatic nerve during Wallerian degeneration: N-cadherin was abundant in myelinating Schwann cells during myelin degradation, while M-cadherin and cadherin-11 may be upregulated in proliferating Schwann cells. M-cadherin, cadherin-11, and N-cadherin were also detected in myofibres and endomysium of adult gastrocnemius muscle. Following neurotomy, cadherin-11 was only transiently increased in denervated myofibres, while M-cadherin was increased and sustained for at least 21 days postoperation. In contrast, N-cadherin was not upregulated in denervated myofibres. Thus, we defined here a combination of cadherins expressed in the adult nerve and muscle, and modulated during Wallerian degeneration and muscle denervation. The comparison of the expression pattern of this combination of cadherins to the one previously described during embryonic development shows that chronically denervated Schwann and muscle cells do not reverse to embryonic state (recapitulative hypothesis), but present specific phenotypic features.
Padilla
F
F
INSERM U 440, Signalisation et Différenciation Cellulaires dans les Systèmes Nerveux et Musculaire, Institut du Fer à Moulin, Paris, France. padilla@ifm.inserm.fr
Marc Mège
R
R
Sobel
A
A
Nicolet
M
M
D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics; D017403:In Situ Hybridization; D051379:Mice; D009121:Muscle Denervation; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D009457:Neuroglia / Q000378:metabolism*; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D012583:Schwann Cells / Q000378:metabolism; D020426:Sciatic Neuropathy / Q000378:metabolism / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics; D015854:Up-Regulation; D014855:Wallerian Degeneration / Q000378:metabolism* / Q000473:pathology
D015820:Cadherins; D004268:DNA-Binding Proteins; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; D012333:RNA, Messenger; D014157:Transcription Factors; C068686:Pax3 protein, mouse; C086960:osteoblast cadherin; C087310:K cadherin