Differentiating neurons process the mechanical stimulus by exerting the protrusive forces through lamellipodia and filopodia. We used optical tweezers, video imaging and immunocytochemistry to analyze the role of non-muscle myosin-II on the protrusive force exerted by lamellipodia and filopodia from developing growth cones (GCs) of isolated Dorsal Root Ganglia (DRG) neurons. When the activity of myosin-II was inhibited by 30â ... 1/4M Blebbistatin protrusion/retraction cycles of lamellipodia slowed down and during retraction lamellipodia could not lift up axially as in control condition. Inhibition of actin polymerization with 25â ...nM Cytochalasin-D and of microtubule polymerization with 500â ...nM Nocodazole slowed down the protrusion/retraction cycles, but only Cytochalasin-D decreased lamellipodia axial motion. The force exerted by lamellipodia treated with Blebbistatin decreased by 50%, but, surprisingly, the force exerted by filopodia increased by 20-50%. The concomitant disruption of microtubules caused by Nocodazole abolished the increase of the force exerted by filopodia treated with Blebbistatin. These results suggest that; i-Myosin-II controls the force exerted by lamellipodia and filopodia; ii-contractions of the actomyosin complex formed by filaments of actin and myosin have an active role in ruffle formation; iii-myosin-II is an essential component of the structural stability of GCs architecture.
|Titolo:||The role of myosin-II in force generation of DRG filopodia and lamellipodia|
|Autori:||Sayyad, W.A.; Amin, L; Fabris, P; Ercolini, E; Torre, V.|
|Data di pubblicazione:||2015|
|Digital Object Identifier (DOI):||10.1038/srep07842|
|Fulltext via DOI:||10.1038/srep07842|
|Appare nelle tipologie:||1.1 Journal article|