Modulation of the inhibitory substrate properties of oligodendrocytes by platelet-derived growth factor.
Although growth cones typically collapse after encountering O1/galactocerebroside (GalC)-positive oligodendrocytes, the majority of growth cones traversed oligodendrocytes, which were raised for 8-10 d in medium containing 10 ng/ml platelet-derived growth factor (PDGF). Oligodendrocytes raised 8-10 d in control medium caused growth cone collapse as they normally do, but failed to elicit this response after being transferred to PDGF-containing medium for an additional 8-10 d. The opposite was observed when PDGF-treated oligodendrocytes were brought to control medium. Growth cones collapsed when contacting these cells. Oligodendrocytes also lost their collapse-inducing activity when raised in medium conditioned by astrocytes, known to produce PDGF. Antibody IN-1 is directed against against neurite growth inhibitors (NI), proteins of 35 and 250 kDa on the surface of O1/GalC-positive oligodendrocytes, which are known to elicit growth cone collapse. IN-1 immunoreactivity was markedly reduced in PDGF-treated oligodendrocytes. However, both PDGF-treated and control oligodendrocytes exhibited myelin-associated glycoprotein, proteolipid protein, and myelin basic protein immunoreactivity. This suggests that PDGF-treatment affects NI expression but does not interfere with the expression of advanced myelin marker proteins. Because NI cause growth cone collapse, the loss of collapse-inducing activity by PDGF-treated oligodendrocytes suggests that PDGF regulates, directly or indirectly, the expression of these proteins.
Lang
D M
DM
Faculty of Biology, University of Konstanz, Germany.
Hille
M G
MG
Schwab
M E
ME
Stuermer
C A
CA
D000818:Animals; D000906:Antibodies / Q000276:immunology; D001253:Astrocytes / Q000502:physiology; D015415:Biomarkers; D017077:Culture Media, Conditioned; D006131:Growth Inhibitors / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000378:metabolism; D009186:Myelin Sheath / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009836:Oligodendroglia / Q000187:drug effects* / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D051381:Rats
D000906:Antibodies; D015415:Biomarkers; D017077:Culture Media, Conditioned; D006131:Growth Inhibitors; D009419:Nerve Tissue Proteins; D010982:Platelet-Derived Growth Factor