Cellular migration

Cellular migration refers to the movement of cells from one location to another. It is a fundamental process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular directions to specific locations. Errors during this process have serious consequences, including intellectual disability, vascular disease, tumor formation and metastasis. An understanding of the mechanism by which cells migrate may lead to the development of novel therapeutic strategies for controlling, for example, invasive tumor cells.

Mechanism of Cellular Migration

Cellular migration is not a random process. It is directed by chemical signals in the cell's environment. The process of cellular migration involves a series of steps: polarization, protrusion, adhesion, contraction and retraction.

• Polarization is the first step in cellular migration. It involves the reorganization of the cytoskeleton and the cell membrane to form a leading edge and a trailing edge. The leading edge is the part of the cell that moves forward in response to the chemical signal, while the trailing edge is the part of the cell that remains stationary.

• Protrusion is the next step in cellular migration. It involves the extension of the leading edge of the cell. This is achieved by the polymerization of actin filaments at the leading edge to push the cell membrane forward.

• Adhesion involves the cell sticking to its substrate. This is achieved by the formation of focal adhesions, which are complexes of proteins that link the actin filaments to the substrate.

• Contraction involves the pulling of the cell body forward. This is achieved by the contraction of myosin II molecules in the cell.

• Retraction involves the detachment of the trailing edge from the substrate. This is achieved by the disassembly of focal adhesions.

Role in Disease

Abnormal cellular migration can lead to a variety of diseases, including cancer, cardiovascular disease, and developmental disorders. For example, in cancer, tumor cells can migrate from their original location to other parts of the body, a process known as metastasis. In cardiovascular disease, the migration of smooth muscle cells can lead to the formation of atherosclerotic plaques. In developmental disorders, abnormal cellular migration can lead to intellectual disability and other neurological disorders.

See Also

• Chemotaxis
• Haptotaxis
• Cell adhesion
• Cytoskeleton