Extracellular matrix

Definition

The extracellular matrix (ECM) is a complex network of proteins and carbohydrates secreted by cells that provides structural and biochemical support to surrounding cells. This intricate framework plays a crucial role in cellular communication, tissue organization, and influences cell behavior, making it essential for processes such as development, healing, and maintenance of tissue integrity.

5 Must Know Facts For Your Next Test

1. The ECM is composed of a variety of proteins, including collagen, elastin, and fibronectin, as well as glycoproteins and proteoglycans.
2. The composition and organization of the ECM can vary significantly between different tissues, influencing their mechanical properties and functions.
3. During development, the ECM plays a vital role in cell fate determination by providing biochemical cues that guide differentiation and tissue formation.
4. In 3D cell culture systems, the ECM mimics the in vivo environment, allowing for more accurate modeling of tissue structure and function.
5. Disruptions or alterations in the ECM can lead to various diseases, including cancer, fibrosis, and developmental disorders.

Review Questions

• How does the extracellular matrix influence cell fate determination during development?
  • The extracellular matrix influences cell fate determination by providing essential biochemical signals and physical cues that guide cell differentiation. Different components of the ECM can interact with cell surface receptors like integrins to activate signaling pathways that determine whether a cell will become a specific type of tissue. For example, changes in ECM composition can affect stem cell differentiation into muscle or neural cells based on the mechanical properties and biochemical signals present.
• Discuss the role of extracellular matrix components such as collagen and fibronectin in 3D cell culture systems.
  • In 3D cell culture systems, components like collagen and fibronectin create a supportive environment that closely resembles natural tissue architecture. Collagen provides structural integrity while fibronectin facilitates cell adhesion and migration. These interactions promote more realistic cellular behavior compared to traditional 2D cultures, allowing researchers to study developmental processes, drug responses, and disease mechanisms in a more physiologically relevant context.
• Evaluate the implications of extracellular matrix dysfunction in diseases such as cancer and fibrosis.
  • Dysfunction of the extracellular matrix has significant implications for diseases like cancer and fibrosis. In cancer, altered ECM composition can promote tumor progression by facilitating invasion and metastasis through changes in cell adhesion and signaling. In fibrosis, excessive ECM deposition leads to stiffening of tissues, impairing function and contributing to organ failure. Understanding these connections highlights the importance of targeting ECM components for therapeutic interventions and underscores its critical role in maintaining tissue homeostasis.

Related terms

Collagen: A primary structural protein found in the extracellular matrix that provides strength and support to various tissues.

Fibronectin: An important glycoprotein in the ECM that aids in cell adhesion, growth, migration, and differentiation.

Integrins:

Transmembrane receptors that facilitate cell-ECM adhesion and play key roles in signaling pathways that affect cell behavior.