2.1. Definition and characteristics of lamellipodia
Lamellipodia are characterized by a complex and dynamic actin
cytoskeleton organization. The actin filaments within lamellipodia form
a dense meshwork, creating a broad, sheet-like protrusion at the leading
edge of migrating cells. This organization is largely regulated by the
Arp2/3 complex and WASP, orchestrating the polymerization of actin
filaments in a branched pattern [8]. The dynamic interplay between
actin assembly and disassembly within lamellipodia allows for rapid
membrane protrusion and retraction, facilitating efficient cell
movement. Lamellipodia are essential for promoting cell motility by
facilitating adhesion to the ECM and establishing focal contacts. The
leading edge of lamellipodia contains membrane ruffles, allowing for
dynamic interactions with the surrounding environment [19]. The
continuous extension and retraction of lamellipodia create a wave-like
pattern, propelling the cell forward. This dynamic behavior is crucial
for processes such as chemotaxis, where cells navigate gradients of
signaling molecules, and haptotaxis, where cells move along
concentration gradients of matrix-bound factors [10,21,22].