Cell movement, also known as
cell motility, is a fundamental process in the life of cells. It involves the dynamic reorganization of the
cytoskeleton and interaction with the extracellular matrix, enabling cells to navigate through their environment. This process is crucial in various physiological and pathological contexts, including embryonic development, immune responses, and cancer metastasis.
Cells move through a series of coordinated steps. First, they extend a protrusion such as a
lamellipodium or filopodium. This is followed by the formation of new adhesions to the substrate at the leading edge. The cell then contracts, pulling itself forward, and finally, detaches at the rear. This process is driven by the polymerization and depolymerization of
actin filaments and the activity of motor proteins like
myosin.
There are several types of cell movement:
The
cytoskeleton is integral to cell movement. It comprises actin filaments, microtubules, and intermediate filaments. Actin filaments are primarily involved in forming cell protrusions and generating contractile forces. Microtubules aid in intracellular transport and spatial organization of organelles, while intermediate filaments provide structural support.
Cell movement is tightly regulated by various signaling pathways. Key regulators include
Rho GTPases, which modulate the organization of the actin cytoskeleton. Additionally, growth factors, cytokines, and the extracellular matrix components provide cues that guide cell movement. Cell adhesion molecules like
integrins also play a crucial role in mediating interactions with the substrate.
Several techniques are employed to study cell movement in histology:
Dysregulation of cell movement is implicated in various diseases. For instance, cancer metastasis involves the invasion and migration of cancer cells from the primary tumor to distant sites. Chronic inflammatory diseases are characterized by the aberrant migration of immune cells. Understanding the mechanisms of cell movement can thus aid in the development of therapeutic strategies for these conditions.
