41.2:
Introduction to Fibroblasts
Fibroblasts are versatile connective tissue cells that perform diverse functions such as healing wounds, maintaining the extracellular matrix or ECM, and transforming into other connective tissue cells.
During wound healing, a blood clot forms, and platelets at the injury site release multiple growth factors. These growth factors activate fibroblasts to transform into myofibroblasts.
These cells can proliferate and produce ECM proteins. ECM proteins facilitate wound healing by binding growth factors, directing cytoskeletal reorganization, and degrading other ECM molecules, among other functions.
Fibroblasts can transform into different cell types of the connective tissue family. Fibroblasts can transdifferentiate into fat cells, bone cells, or smooth muscle cells based on their physical or chemical environment.
Fibroblasts can also be reprogrammed to form induced pluripotent cells, promising tools in regenerative medicine.
41.2:
Introduction to Fibroblasts
Rudolph Virchow discovered spindle-shaped cells called fibroblasts in 1858. Inactive fibroblasts, called fibrocytes, become activated by various stimuli, such as growth factors and inflammatory cytokines. Activated fibroblasts play a crucial role in wound healing, inflammation, formation of new blood vessels, and cancer progression. Uncontrolled activation of fibroblasts results in fibrosis, the excess deposition of fibrous tissue, which can lead to scarring and affect normal organs. This results in fibrotic disorders such as liver cirrhosis, kidney cirrhosis, and cardiac fibrosis.
In addition to being easily accessible in the body, fibroblasts can also be cultured in the laboratory as primary cell cultures or permanent cell lines. Fibroblast cell lines have been used for years to determine the pathogenesis of certain specific diseases. Currently, fibroblasts are also used for modeling diseases.
Fibroblasts can retain the memory of their anatomical positions through changes in gene expression and chromatin modifications. This includes memories of the location of their tissue of origin and memories of previous inflammation. This property of keeping memories of various stimuli supports fibroblasts’ role in immune responses and tissue homeostasis.
Suggested Reading
- Kendall, R. T., & Feghali-Bostwick, C. A. (2014). Fibroblasts in fibrosis: novel roles and mediators. Frontiers in pharmacology, 5, 123.
- Chang, H. Y., Chi, J. T., Dudoit, S., Bondre, C., van de Rijn, M., Botstein, D., & Brown, P. O. (2002). Diversity, topographic differentiation, and positional memory in human fibroblasts. Proceedings of the National Academy of Sciences, 99(20), 12877-12882.
- Fernandes, I. R., Russo, F. B., Pignatari, G. C., Evangelinellis, M. M., Tavolari, S., Muotri, A. R., & Beltrão-Braga, P. C. B. (2016). Fibroblast sources: Where can we get them?. Cytotechnology, 68(2), 223-228.
- Kirk, T., Ahmed, A., & Rognoni, E. (2021). Fibroblast memory in development, homeostasis and disease. Cells, 10(11), 2840.