The key difference between regeneration and fibrosis is that regeneration involves replacing injured cells with cells of the same type while fibrosis involves replacing parenchyma tissue with connective tissues, leading to the formation of permanent scar tissue.
Repairing of the damaged tissue is a fundamental biological process. This process replaces dead and damaged cells orderly, and it is critically important for survival. If neglected, it can lead to the formation of permanent scar tissue, an organ failure and death. There are two distinct phases in this repair process. They are regenerative phase and fibrosis. In the regenerative phase, the injured cells are replaced by the same kind of cells. In fibrosis, connective tissue replaces normal parenchyma tissue.
CONTENTS
1. Overview and Key Difference
2. What is Regeneration
3. What is Fibrosis
4. Similarities Between Regeneration and Fibrosis
5. Side by Side Comparison – Regeneration vs Fibrosis in Tabular Form
6. Summary
What is Regeneration?
Regeneration is a critical biological process that is fundamental to the survival of the organism. In regeneration, complete restoration of the structure and function of the damaged tissue takes place. In order for regeneration to happen, the cells should not be in the post-mitotic phase, and the connective tissue framework should be intact. Here, the injured cells are replaced by the same type of cells in regeneration. As a result, the injured tissue is completely repaired, and its structure and function are restored by the regeneration process. Unlike in fibrosis, there is no scar formation in regeneration. Regeneration takes place in many tissues. Therefore, tissue regeneration includes regeneration of epithelial tissue, regeneration of fibrous tissue, regeneration of cartilage tissue and bone tissue, regeneration of blood vessels, regeneration of muscle tissue, and regeneration of nerve tissue.
Figure 01: Regeneration
Macrophages play a key role in tissue regeneration. They create a regeneration-permissive environment. Moreover, several other cell types, including monocytes, are also needed for regeneration. In addition, blood vessels play a critical role in nerve regeneration by serving as guides or tracks for the regenerative nerve cells to grow along.
What is Fibrosis?
Fibrosis is a phase of wound healing or repairing process. It is the process of pathological wound healing in which connective tissue replaces normal parenchymal tissue. Ultimately it results in the formation of permanent scar tissue. It will also lead to the loss of function in the tissue. The deposition of connective tissue interferes with or totally inhibits the normal architecture and function of the underlying organ or tissue. Fibrosis restores some original structures but can cause structural derangements.
Figure 02: Fibrosis
There are several reasons for fibrosis. They are repeated injuries, chronic inflammation and repair. During fibrosis, excessive accumulation of extracellular matrix components, such as the collagen, takes place, leading to the formation of a permanent fibrotic scar. Fibrosis occurs in many body tissues. It can occur as a part of the normal healing process or as a pathological process. There are several preventive measures for fibrosis. They include stopping smoking, avoiding exposure to known irritants, attending any flu jabs and oxygen therapy. Pulmonary fibrosis, cardiac fibrosis and liver fibrosis are the three main types of fibrosis.
What are the Similarities Between Regeneration and Fibrosis?
- Regeneration and fibrosis are two distinct phases of the tissue repair process.
- Both share a common cascade of injury-induced events.
What is the Difference Between Regeneration and Fibrosis?
Regeneration is the complete restoration of the organ structure and function after an injury while fibrosis is a phase of tissue repair in which connective tissues replaces parenchymal tissues. Thus, this is the key difference between regeneration and fibrosis. In regeneration, complete restoration of the structure of the damaged is possible. Fibrosis restores some original structures but can cause structural derangements.
Below is a summary tabulation of the difference between regeneration and fibrosis.
Summary – Regeneration vs Fibrosis
Regeneration and fibrosis are two phases of the tissue repair process. In regeneration, the injured cells are replaced by the same type of cells. As a result, complete restoration of the structure and function of the tissue takes place. On the other hand, in fibrosis, connective tissue replaces the parenchymal tissue. A permanent scar formation takes place. Though some of the tissues are restored, the function of the tissue cannot be completely restored by fibrosis. Thus, this summarizes the difference between regeneration and fibrosis.
Reference:
1. “Fibrosis.” Wikipedia, Wikimedia Foundation, 9 Dec. 2020, Available here.
2. Cordero-Espinoza, Lucía, and Meritxell Huch. “The Balancing Act of the Liver: Tissue Regeneration versus Fibrosis.” The Journal of Clinical Investigation, American Society for Clinical Investigation, 2 Jan. 2018, Available here.
Image Courtesy:
1. “Liver regeneration” By ELMcKinlay – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Cardiac amyloidosis very high mag movat” By Nephron – Own work (CC BY-SA 3.0) via Commons Wikimedia
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