Growth cone collapse and neurite retraction from cultured Helisoma neurons in response to antibody Fab fragments against an extracellular matrix protein.
Helisoma neurons require a factor(s) present in conditioned medium (CM), for successful neurite outgrowth in vitro. A approximately 300 kDa Helisoma extracellular matrix (ECM) protein has been identified in CM and is necessary for neurite initiation. Here we show that purified approximately 300 kDa ECM protein supports outgrowth. Furthermore, anti- approximately 300 kDa Fab fragments cause a rapid, dose-dependent decrease in outgrowth when added to neurons already growing in CM, culminating in growth cone collapse and neurite retraction at 200 micrograms/ml. Collapsing growth cones rapidly lost lamellipodia and filopodia transformed into long filamentous strands. Contortion of microtubules in retracting neurites into serpentine shapes, apparently by compressive forces, suggests that large-scale microtubule depolymerization is not a prerequisite for growth cone retraction. These results imply that substrate-bound approximately 300 kDa CM protein is necessary and sufficient for CM-stimulated growth cone initiation and neurite elongation from Helisoma neurons.
Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston 29425.
J D
JD
Miller
R D
RD
Hadley
C E
CE
Hammond
D000818:Animals; D017077:Culture Media, Conditioned; D016326:Extracellular Matrix Proteins / Q000276:immunology* / Q000302:isolation & purification; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000254:growth & development; D015151:Immunoblotting; D007140:Immunoglobulin Fab Fragments / Q000276:immunology*; D007150:Immunohistochemistry; D008870:Microtubules / Q000187:drug effects / Q000648:ultrastructure; D016501:Neurites / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D012908:Snails / Q000502:physiology*
D017077:Culture Media, Conditioned; D016326:Extracellular Matrix Proteins; D007140:Immunoglobulin Fab Fragments