Regeneration cell adhesion molecules

Cell adhesion molecules may also function in regeneration 118... 

Cell adhesion molecules (CAMs) play critical roles in all facets of nervous system development and maintenance. Important phenomena in which CAMs are involved include initial formation of the neural tube and the neural crest, migration of all neurons and glial cells, axonal outgrowth and guidance, target selection, synaptic stabilization and plasticity, myelination and nerve regeneration after injury (see Chs 4,24,28-30 and 53). Adhesion molecules interact with each other and with nonadhesive cell-surface and/or cytoplasmic molecules, and, in the two... 

Adhesion molecules such as LI, neural cell adhesion molecule (N-CAM) and N-cadherin promote axonal regeneration by homophilic interactions between axons and Schwann cell surfaces (see Ch. 7). The expression of p75 (low affinity NGF receptor, Ch. 27) is also increased at the Schwann cell surface after injury. Extracellular matrix molecules, such as tenascin and proteoglycans, increase the regenerative potential of damaged peripheral nerves by binding to integrins on the axonal surface. 

Polysialic acid (PSA) is a linear homopolymer of a2-8- or a2-9-linked sialic acid attached to protein scaffolds inclnding the neural cell adhesion molecule (NCAM). Two Golgi-resident polysialyltransferases, PST and STX, are responsible for its synthesis. Although PSA is widely distributed in embryonic tissues, it is normally found only in regenerating neural and muscle tissues in adults. Neo-expression of PSA is often associated with metastatic cancer (115). 

Martini R, Schachner M. 1988. Immunoelectron microscopic localization of neural cell adhesion molecules (LI, N-CAM, and myelin-associated glycoprotein) in regenerating adult mouse sciatic nerve. J CeU Biol 106 1735-1746. 

For example, PA self-assembly is hybridized with fibronectin epitope RGDS (cell adhesion molecule) and HA crystals that nucleate around the phosphoserine residues of PA under appropriate physiological conditions (referring to the biomineralization section in Chapter 4), forming 3-D biomimetic systems as a matrix to promote bone regeneration [15]. Efficacy of this tissue engineering scaffold was tested in an rat... 

Becker, T., Becker, C. G., Niemann, U., Naujoks, M. C., Gerardy, S. R., and Roth, G., 1993b, Amphibian-specific regulation of polysialic acid and the neural cell adhesion molecule in development and regeneration of the retinotectal system of the salamander Pleurodeles waltl, J. Comp. Neurol. 336 532-544. 

Cell surface adhesion molecules, which promote regeneration, are expressed on plasmalemma of both Schwann cells and regenerating peripheral axons 520... 

Cadherins are Ca -binding adhesion molecules that mediate homophilic interaction between cells. Cadherins are particularly important for selective fasciculation of regenerating axons. For instance, E-cadherin mediates attachment of unmyelinated sensory fibers and stabilizes glial network [42], and N-cadherin mediates axon-Schwann ceU interactions during regeneration [39, 43]. 

Are there other roles for the basal lamina during regeneration Once axons are guided to the muscle basal lamina by Schwann cell columns, adhesive molecules in the muscle basal lamina may play a docking function to help stabilize synapses. Existing end-plates, thereby, may be better able than other surfaces of muscle to retain contacts with... 

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