Fibronectin

Definition

Fibronectin is a high-molecular-weight glycoprotein that plays a crucial role in cell adhesion, growth, migration, and differentiation. It acts as a bridge between cells and the extracellular matrix (ECM), helping to organize the ECM structure and facilitating communication between cells and their environment.

5 Must Know Facts For Your Next Test

1. Fibronectin exists in two forms: soluble fibronectin found in blood plasma and insoluble fibronectin which is part of the extracellular matrix.
2. It binds to integrins on the cell surface, which helps anchor cells to the ECM and initiates intracellular signaling pathways.
3. Fibronectin is crucial during embryonic development, wound healing, and tissue repair by promoting cell migration and proliferation.
4. It is produced by various cell types, including fibroblasts and endothelial cells, showcasing its importance in multiple tissues.
5. Alterations in fibronectin levels or function can be associated with various diseases, including cancer, fibrosis, and cardiovascular disorders.

Review Questions

• How does fibronectin facilitate cell communication with the extracellular matrix?
  • Fibronectin plays a key role in cell communication with the extracellular matrix by serving as a bridge between cells and ECM components. It binds to integrin receptors on the cell surface, which allows for physical attachment to the ECM. This interaction not only helps to stabilize the cellular environment but also initiates signaling cascades that influence cell behavior such as migration, proliferation, and differentiation.
• Discuss the significance of fibronectin in processes like wound healing and tissue repair.
  • Fibronectin is vital in wound healing and tissue repair because it promotes cell migration to the site of injury. As cells adhere to fibronectin through integrins, they can move into the damaged area, proliferate, and eventually help restore tissue integrity. Additionally, fibronectin helps to organize other ECM components that are essential for proper tissue structure and function during the repair process.
• Evaluate the implications of altered fibronectin levels in diseases such as cancer and fibrosis.
  • Altered levels of fibronectin can have significant implications for diseases like cancer and fibrosis. In cancer, increased fibronectin can enhance tumor cell adhesion and invasion, contributing to metastasis. Conversely, in fibrosis, excessive fibronectin deposition can lead to tissue stiffness and impaired organ function. Understanding these changes helps researchers target fibronectin pathways for potential therapeutic interventions aimed at managing these conditions.

Related terms

Extracellular Matrix: A complex network of proteins and carbohydrates that provides structural and biochemical support to surrounding cells.

Integrins: Transmembrane receptors that facilitate cell-ECM adhesion and are essential for transmitting signals between the ECM and the cell.

Laminin:

A key glycoprotein in the basement membrane that, along with fibronectin, plays a vital role in cell attachment and tissue structure.