title: Laminin B1 and collagen type IV gene expression in transected peripheral nerve: reinnervation compared to denervation.
abstract: The expression of B1 laminin and type IV collagen was followed in the microsurgically isolated endoneurium of transected rat sciatic nerves from 3 days until 8 weeks. Northern hybridizations revealed that after nerve transection the proximal stumps of denervated, as well as freely regenerating, nerves showed a markedly increased expression of laminin and type IV collagen which lasted from 3 days up to 8 weeks. In the distal stumps, close to the site of transection (2-7 mm), the expression of laminin, and to a certain extent that of type IV collagen, seemed to be enhanced if free axonal reinnervation was allowed. Further distally (10-15 mm), the patterns of B1 laminin and type IV collagen expression were similar in both experimental groups, so that an increased expression was noticed during the first 2 weeks. The present results suggest that laminin and type IV collagen gene expression is markedly different in different parts of transected rat sciatic nerve. During peripheral nerve regeneration, there is a long-lasting basement membrane gene expression in the proximal stump. In the distal part of the transected nerve, the axonal reinnervation possibly up-regulates, but is not essential for, the expression of B1 laminin and type IV collagen.
mesh_terms: D000818:Animals; D001369:Axons / Q000737:chemistry / Q000502:physiology; D015152:Blotting, Northern; D003094:Collagen / Q000235:genetics* / Q000378:metabolism; D003714:Denervation; D015870:Gene Expression / Q000235:genetics* / Q000502:physiology; D007797:Laminin / Q000235:genetics* / Q000378:metabolism; D009416:Nerve Regeneration; D010525:Peripheral Nerves / Q000378:metabolism* / Q000502:physiology* / Q000601:surgery*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D009418:S100 Proteins / Q000032:analysis; D013194:Staining and Labeling
chemical_list: D007797:Laminin; D012333:RNA, Messenger; D009418:S100 Proteins; D003094:Collagen