keratinocyte migration

Definition

Target type: biologicalprocess

The directed movement of a keratinocyte, epidermal cells which synthesize keratin, from one site to another. [ISBN:0721662544]

Keratinocyte migration is a complex process that plays a crucial role in wound healing, skin development, and immune responses. It involves a series of coordinated events, including detachment from the basal layer, migration across the extracellular matrix, and re-attachment at the wound edge.

**1. Detachment from the Basal Layer:**
- Keratinocytes in the basal layer are tightly connected by cell-cell junctions, primarily desmosomes and adherens junctions.
- Upon receiving signals, such as growth factors or cytokines, keratinocytes initiate the breakdown of these junctions.
- Enzymes like matrix metalloproteinases (MMPs) and disintegrins and metalloproteinases (ADAMs) are involved in the degradation of the extracellular matrix components that hold keratinocytes together.

**2. Migration Across the Extracellular Matrix:**
- Once detached, keratinocytes extend protrusions called lamellipodia and filopodia, which act as sensing and exploratory structures.
- These protrusions are driven by actin polymerization, which is regulated by signaling pathways involving Rho GTPases like Rac and Rho.
- Keratinocytes adhere to the extracellular matrix components, such as fibronectin, collagen, and laminin, through integrin receptors.
- Integrin receptors bind to the extracellular matrix and link to the cytoskeleton, providing traction for movement.

**3. Re-attachment at the Wound Edge:**
- As keratinocytes migrate towards the wound edge, they encounter other keratinocytes and the surrounding matrix.
- They re-establish cell-cell junctions and adhere to the matrix, contributing to wound closure.
- Growth factors and cytokines secreted by the wound environment and migrating cells stimulate proliferation and differentiation of keratinocytes, leading to tissue regeneration.

**4. Key Factors Influencing Keratinocyte Migration:**
- **Growth Factors:** Epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and platelet-derived growth factor (PDGF) stimulate keratinocyte migration.
- **Cytokines:** Interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) enhance keratinocyte migration.
- **Extracellular Matrix Components:** Fibronectin, collagen, and laminin provide adhesion sites for keratinocytes.
- **Cell-Cell Interactions:** Cadherins and other cell adhesion molecules regulate cell-cell contacts and promote migration.
- **Mechanical Forces:** Tension and compression forces generated during migration influence cell shape and directionality.

**Overall, keratinocyte migration is a tightly regulated and dynamic process that requires the coordinated action of multiple signaling pathways, adhesion molecules, and cytoskeletal components. It plays a critical role in wound healing and skin regeneration, highlighting the importance of understanding this process for therapeutic interventions.'
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Proteins (2)

Compounds (65)