What is the Difference Between Fibroblast and Myofibroblast?

Fibroblasts and myofibroblasts are both cell types involved in the production and maintenance of the extracellular matrix, but they have distinct characteristics and functions:

Fibroblasts:

• Primary role in producing and maintaining extracellular matrix.
• Present throughout the human body.
• Expressed in the normal heart, with a smooth, regular surface and a large nucleus.

Myofibroblasts:

• Originate from fibroblasts and are not part of normal cardiac tissue, appearing only following cardiac injury.
• Function in active fibrosis by expressing high levels of extracellular matrix and fibrogenic cytokines.
• Distinguished from fibroblasts by their high level of exocytotic activity, presence of smooth muscle actin, and bundles of microfilaments that terminate at the cell surface in a structure called the fibronexus or mature local adhesion.

Fibroblasts can differentiate into myofibroblasts upon mechanical or biochemical stimulation, such as during wound healing or in response to injury. The transition from fibroblast to myofibroblast is regulated by various factors, including mechanical and physical stress. The presence of myofibroblasts can either promote healing and prevent scar formation or inhibit healing and promote fibrosis, depending on the specific conditions.

Comparative Table: Fibroblast vs Myofibroblast

Fibroblasts and myofibroblasts are both involved in the formation of extracellular matrix and play a key role in tissue repair. However, they have distinct differences in their structure and function. Here is a table summarizing the differences between fibroblasts and myofibroblasts:

Fibroblasts are typically found in the mesenchymal cells of many tissues, while myofibroblasts are differentiated fibroblasts that have developed contractile activity. Myofibroblasts are not part of normal cardiac tissue and only appear following cardiac injury. They play a more active role in cardiac function compared to fibroblasts.