| First Author | Cifuentes-Diaz C | Year | 1998 |
| Journal | Cell Mol Biol (Noisy-le-grand) | Volume | 44 |
| Issue | 2 | Pages | 357-79 |
| PubMed ID | 9593587 | Mgi Jnum | J:47799 |
| Mgi Id | MGI:1206051 | Citation | Cifuentes-Diaz C, et al. (1998) The peripheral nerve and the neuromuscular junction are affected in the tenascin-C-deficient mouse. Cell Mol Biol (Noisy-Le-Grand) 44(2):357-79 |
| abstractText | A thorough examination of the structure and plasticity of the neuromuscular system was performed in tenascin-C mutant mice deficient in tenascin-C. The study of the peripheral nerve revealed a number of abnormal features. In the motor nerve, numerous unmyelinated and myelinated fibers with degraded myelin were present. Schwann cell processes often enclosed degenerative terminals. Transgene (beta-galactosidase) expression analyzed at the ultrastructural level was found to be unequally distributed in the mutant's neuromuscular tissues. At the NMJ, preterminal disorganization was prevalent. Some axon terminals exhibited abnormal overgrowth. A surprising lack of beta-galactosidase expression at some cellular sites known to possess tenascin-C in wild type mice correlated best with marked changes in the cytoarchitecture of the peripheral nerve and NMJ. In some other -but not all- cellular sites which normally express the molecule, immunofluorescence analysis suggested the presence of significant but low levels of tenascin-C-like immunoreactivity together with beta-galactosidase expression. Messenger RNA detection by RT-PCR confirmed the presence of low amounts of tenascin-C mRNA in skeletal muscle suggesting that the mice deficient in tenascin-C are not complete knock-outs of this gene, but low-expression mutants. Following in vivo injections of botulinum type-A toxin, we observed a greatly reduced sprouting response of the motor nerves in tenascin-C mutant mice. We also observed that N-CAM and beta-catenin were overexpressed in the mutant. Our results suggest that tenascin-C is involved both in stabilization and in plasticity of the NMJ. |
