Abstract
We have previously shown that myelin-associated glycoprotein (MAG) inhibits neurite growth from a neuronal cell line. In this study we show that 60% of axonal growth cones of postnatal day 1 hippocampal neurons collapsed when they encountered polystyrene beads coated with recombinant MAG (rMAG). Such collapse was not observed with denatured rMAG. Neurite growth from rat embryonic hippocampal and neonatal cerebellar neurons was also inhibited about 80% on tissue culture substrates coated with rMAG. To investigate further the inhibitory activity of MAG in myelin, we purified myelin from MAG-deficient mice and separated octylglucoside extracts of myelin by diethylaminoethyl (DEAE) ion-exchange chromatography. Although there was no significant difference in neurite growth on myelin purified from MAG-/- and MAG+/+ mice, differences were observed in the fractionated material. The major inhibitory peak that is associated with MAG in normal mice was significantly reduced in MAG-deficient mice. These results suggest that although MAG contributes significantly to axon growth inhibition associated with myelin, its lack in MAG-deficient mice is masked by other non-MAG inhibitors. Axon regeneration in these mice was also examined after thoracic lesions of the corticospinal tracts. A very small number of anterogradely labeled axons extended up to 13.2 mm past the lesion in MAG-/- mice. Although there is some enhancement of axon generation, the poor growth after spinal cord injury in MAG-/mice may be due to the presence of other non-MAG inhibitors. The in vitro studies, however, provide the first evidence that MAG modulates growth cone behavior and inhibits neurite growth by causing growth cone collapse.
| Original language | English |
|---|---|
| Pages (from-to) | 404-414 |
| Number of pages | 11 |
| Journal | Journal of Neuroscience Research |
| Volume | 46 |
| Issue number | 4 |
| DOIs | |
| State | Published - 1996 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Neuroscience(all)
Cite this
Myelin-associated glycoprotein inhibits neurite/axon growth and causes growth cone collapse. / Li, Maria; Shibata, Annemarie; Li, Chumei; Braun, Peter E.; McKerracher, Lisa; Roder, John; Kater, Stanley B.; David, Samuel.
In: Journal of Neuroscience Research, Vol. 46, No. 4, 1996, p. 404-414.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Myelin-associated glycoprotein inhibits neurite/axon growth and causes growth cone collapse
AU - Li, Maria
AU - Shibata, Annemarie
AU - Li, Chumei
AU - Braun, Peter E.
AU - McKerracher, Lisa
AU - Roder, John
AU - Kater, Stanley B.
AU - David, Samuel
PY - 1996
Y1 - 1996
N2 - We have previously shown that myelin-associated glycoprotein (MAG) inhibits neurite growth from a neuronal cell line. In this study we show that 60% of axonal growth cones of postnatal day 1 hippocampal neurons collapsed when they encountered polystyrene beads coated with recombinant MAG (rMAG). Such collapse was not observed with denatured rMAG. Neurite growth from rat embryonic hippocampal and neonatal cerebellar neurons was also inhibited about 80% on tissue culture substrates coated with rMAG. To investigate further the inhibitory activity of MAG in myelin, we purified myelin from MAG-deficient mice and separated octylglucoside extracts of myelin by diethylaminoethyl (DEAE) ion-exchange chromatography. Although there was no significant difference in neurite growth on myelin purified from MAG-/- and MAG+/+ mice, differences were observed in the fractionated material. The major inhibitory peak that is associated with MAG in normal mice was significantly reduced in MAG-deficient mice. These results suggest that although MAG contributes significantly to axon growth inhibition associated with myelin, its lack in MAG-deficient mice is masked by other non-MAG inhibitors. Axon regeneration in these mice was also examined after thoracic lesions of the corticospinal tracts. A very small number of anterogradely labeled axons extended up to 13.2 mm past the lesion in MAG-/- mice. Although there is some enhancement of axon generation, the poor growth after spinal cord injury in MAG-/mice may be due to the presence of other non-MAG inhibitors. The in vitro studies, however, provide the first evidence that MAG modulates growth cone behavior and inhibits neurite growth by causing growth cone collapse.
AB - We have previously shown that myelin-associated glycoprotein (MAG) inhibits neurite growth from a neuronal cell line. In this study we show that 60% of axonal growth cones of postnatal day 1 hippocampal neurons collapsed when they encountered polystyrene beads coated with recombinant MAG (rMAG). Such collapse was not observed with denatured rMAG. Neurite growth from rat embryonic hippocampal and neonatal cerebellar neurons was also inhibited about 80% on tissue culture substrates coated with rMAG. To investigate further the inhibitory activity of MAG in myelin, we purified myelin from MAG-deficient mice and separated octylglucoside extracts of myelin by diethylaminoethyl (DEAE) ion-exchange chromatography. Although there was no significant difference in neurite growth on myelin purified from MAG-/- and MAG+/+ mice, differences were observed in the fractionated material. The major inhibitory peak that is associated with MAG in normal mice was significantly reduced in MAG-deficient mice. These results suggest that although MAG contributes significantly to axon growth inhibition associated with myelin, its lack in MAG-deficient mice is masked by other non-MAG inhibitors. Axon regeneration in these mice was also examined after thoracic lesions of the corticospinal tracts. A very small number of anterogradely labeled axons extended up to 13.2 mm past the lesion in MAG-/- mice. Although there is some enhancement of axon generation, the poor growth after spinal cord injury in MAG-/mice may be due to the presence of other non-MAG inhibitors. The in vitro studies, however, provide the first evidence that MAG modulates growth cone behavior and inhibits neurite growth by causing growth cone collapse.
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UR - http://www.scopus.com/inward/citedby.url?scp=0029831520&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1097-4547(19961115)46:4<404::AID-JNR2>3.0.CO;2-K
DO - 10.1002/(SICI)1097-4547(19961115)46:4<404::AID-JNR2>3.0.CO;2-K
M3 - Article
C2 - 8950700
AN - SCOPUS:0029831520
VL - 46
SP - 404
EP - 414
JO - Journal of Neuroscience Research
JF - Journal of Neuroscience Research
SN - 0360-4012
IS - 4
ER -