What is the Difference Between Fibroblast and Myofibroblast

The key difference between fibroblast and myofibroblast is that fibroblast is found in the mesenchymal cells that are normally present in the stroma of many tissues, while myofibroblast is a differentiated fibroblast with contractile activity.

Fibroblast and myofibroblast play a key role in skin homeostasis and physiological tissue repair. They are usually embedded in the extracellular matrix they secrete. The microenvironment of these cells forms a network of tissues during tissue repair, which leads to tissue differentiation, proliferation, or apoptosis. Fibroblasts are capable of modifying the mechanical properties of the extracellular matrix within the tissue and transition to myofibroblasts. Myofibroblasts are specialized fibroblasts with contractile activity.

CONTENTS

1. Overview and Key Difference
2. What is Fibroblast 
3. What is Myofibroblast
4. Similarities – Fibroblast and Myofibroblast
5. Fibroblast vs Myofibroblast in Tabular Form
6. Summary – Fibroblast vs Myofibroblast

What is Fibroblast?

Fibroblast is a biological cell that produces the extracellular matrix and collagen and is present commonly in the connective tissues producing the structural framework for animal tissues. In the connective tissue of animals, fibroblasts are the most common type of cell present. These cells have a branched cytoplasm. The cytoplasm surrounds an elliptical speckled nucleus with two or more nuclei.

Figure 01: Fibroblasts

All fibroblasts can be identified by the characteristic abundant rough endoplasmic reticulum. Fibroblasts do not form flat monolayers, unlike the epithelial cells that line body structures. They are also not restricted by a polarizing attachment to a basal lamina on one side. Fibroblasts may contribute to basal lamina components in some situations. The function of fibroblasts is to produce collagen fibers, glycosaminoglycans, reticular and elastic fibers. They also play a major role in wound healing by contracting the edges of the wound. Apart from the two common functions, fibroblasts play a critical role in an immune response to a tissue injury and are also involved in initiating inflammation in the presence of pathogenic microorganisms.

What is Myofibroblast?

Myofibroblast is a contractile fusiform cell with the presence of α-smooth muscle actin within its cytoplasmic stress fibers. Myofibroblasts develop during the differentiation process of fibroblasts. Fibroblasts can be transformed into myofibroblasts using photo-remediation. Myofibroblasts express high levels of cytokines, extracellular matrix, and α-smooth muscle actin. They play an important role in inflammation, connective tissue deposition, and lung tissue mechanics.

Figure 02: Myofibroblasts

Moreover, myofibroblasts were identified in the granulation tissue during skin wound healing. Myofibroblasts are typically found in granulation tissue, scar tissue (fibrosis), and the stroma of tumors. They are also present in the gastrointestinal tract and genitourinary tract. In these places, myofibroblasts are present sub-epithelially in the mucosa surfaces.

What are the Similarities Between Fibroblast and Myofibroblast?

• Fibroblast and myofibroblast are two types of biological cells.
• They have a common origin.
• Both fibroblasts and myofibroblasts play a major role in wound healing.
• Moreover, both cells speed up wound healing by contracting the edges of the wound efficiently.

What is the Difference Between Fibroblast and Myofibroblast?

Fibroblast is found in the mesenchymal cells that are normally present in the stroma of many tissues, while myofibroblast is a differentiated fibroblast. Thus, this is the key difference between fibroblast and myofibroblast. Also, a fibroblast is a large, flat, and elongated cell that extends out from the ends of the cell body. Whereas, the myofibroblasts are large cells with ruffled membranes with a highly active endoplasmic reticulum. Moreover, fibroblasts do not have actin smooth muscles, while myofibroblasts have actin smooth muscles.

The below infographic presents the differences between fibroblast and myofibroblast in tabular form for side by side comparison.

Summary – Fibroblast vs Myofibroblast

Fibroblast and myofibroblast play a key role in physiological tissue repair or wound healing. Fibroblast is found in the mesenchymal cells that are normally present in the stroma of many tissues. Whereas, myofibroblast is a differentiated fibroblast. Moreover, the function of fibroblasts is to produce collagen fibers, glycosaminoglycans, reticular and elastic fibers. Meanwhile, myofibroblasts play an important role in inflammation, connective tissue deposition, and lung tissue mechanics. Furthermore, myofibroblasts develop as a result of the differentiation of fibroblasts. So, this summarizes the difference between fibroblast and myofibroblast.

Reference:

1. HS;, Baum J;Duffy. “Fibroblasts and Myofibroblasts: What Are We Talking about?” Journal of Cardiovascular Pharmacology, U.S. National Library of Medicine.
2. McAnulty, Robin J. “Fibroblasts and Myofibroblasts: Their Source, Function and Role in Disease.” The International Journal of Biochemistry & Cell Biology, Pergamon, 23 Nov. 2006.

Image Courtesy:

1. “Fibroblasts 2” By Judyta Dulnik – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Miofibroblastos cardiacos” By Leslye Venegas y Danica Jimenez – Own work (CC BY 4.0) via Commons Wikimedia

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