Immunological evidence that the neural adhesion molecule L1 is expressed in fish brain and optic nerve

TY - JOUR

T1 - Immunological evidence that the neural adhesion molecule L1 is expressed in fish brain and optic nerve

T2 - possible association with optic nerve regeneration

AU - Blaugrund, E

AU - Bartsch, U

AU - Martini, R

AU - Schachner, M

AU - Schwartz, M

PY - 1990/10/22

Y1 - 1990/10/22

N2 - In the mammalian peripheral nervous system (PNS), expression of the neural adhesion molecule L1 on Schwann cells and neurons has been correlated with axonal growth during development and regeneration. The present study was undertaken to examine whether a similar correlation exists between a lesion-induced increase of L1 expression and regenerative capacity in the central nervous system (CNS). The fish optic nerve was used as a model for a successfully regenerating region of the CNS. Immunochemical and immunohistological experiments carried out with immunoaffinity purified polyclonal antibodies, generated against L1 from mouse brain, showed that carp optic nerve and brain, but not liver, contained L1 immunoreactivity. Western blot analysis of brain tissue yielded one distinct band at 200 kDa, while a double band at 200 kDa and two low-molecular weight bands at 120 and 100 kDa, possibly degradation products, were seen in the optic nerve. Immunohistological examination of normal optic nerves revealed L1 immunoreactivity, predominantly associated with connective tissue boundaries of nerve fascicles and with blood vessels, as well as inside axonal fascicles. L1 immunoreactivity was increased by 25%, 8 days after crushing of the optic nerve, as determined by radioimmunoassay on a nerve segment distal to the site of injury and compared with untreated control nerves. Increased levels of L1 were also seen by immunohistology and found to be predominantly associated, as in the normal nerve, with connective tissue boundaries and blood vessels. These observations suggest that a lesion-induced increase in L1 expression in the fish optic nerve is associated with axonal regrowth in the CNS.

AB - In the mammalian peripheral nervous system (PNS), expression of the neural adhesion molecule L1 on Schwann cells and neurons has been correlated with axonal growth during development and regeneration. The present study was undertaken to examine whether a similar correlation exists between a lesion-induced increase of L1 expression and regenerative capacity in the central nervous system (CNS). The fish optic nerve was used as a model for a successfully regenerating region of the CNS. Immunochemical and immunohistological experiments carried out with immunoaffinity purified polyclonal antibodies, generated against L1 from mouse brain, showed that carp optic nerve and brain, but not liver, contained L1 immunoreactivity. Western blot analysis of brain tissue yielded one distinct band at 200 kDa, while a double band at 200 kDa and two low-molecular weight bands at 120 and 100 kDa, possibly degradation products, were seen in the optic nerve. Immunohistological examination of normal optic nerves revealed L1 immunoreactivity, predominantly associated with connective tissue boundaries of nerve fascicles and with blood vessels, as well as inside axonal fascicles. L1 immunoreactivity was increased by 25%, 8 days after crushing of the optic nerve, as determined by radioimmunoassay on a nerve segment distal to the site of injury and compared with untreated control nerves. Increased levels of L1 were also seen by immunohistology and found to be predominantly associated, as in the normal nerve, with connective tissue boundaries and blood vessels. These observations suggest that a lesion-induced increase in L1 expression in the fish optic nerve is associated with axonal regrowth in the CNS.

KW - Animals

KW - Blotting, Western

KW - Brain

KW - Carps

KW - Cell Adhesion Molecules, Neuronal

KW - Immunohistochemistry

KW - In Vitro Techniques

KW - Mice

KW - Molecular Weight

KW - Nerve Regeneration

KW - Nerve Tissue Proteins

KW - Optic Nerve

KW - Radioimmunoassay

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

M3 - SCORING: Journal article

C2 - 2265355

VL - 530

SP - 239

EP - 244

JO - BRAIN RES

JF - BRAIN RES

SN - 0006-8993

IS - 2

ER -