fibroblasti

Fibroblasti, known in English as fibroblasts, are resident mesenchymal cells located in connective tissues throughout the body. They are typically spindle-shaped and dispersed within the extracellular matrix. Their primary functions are the synthesis and remodeling of the extracellular matrix, including collagen types I and III, elastin, fibronectin, and proteoglycans. They also secrete matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) that regulate ECM turnover, and they interact with the ECM via cell surface receptors to migrate and proliferate in response to tissue injury.

In homeostasis, fibroblasti maintain tissue structure and participate in repair after injury. Following damage, they become activated fibroblasts and can differentiate into myofibroblasts, which express alpha-smooth muscle actin and gain contractile capacity to help close wounds. As repair completes, most myofibroblasts undergo apoptosis or revert to a quiescent state; prolonged myofibroblast activity contributes to scarring and fibrotic changes.

Fibroblasti show tissue-specific variation, reflecting diverse roles. Dermal fibroblasti support skin integrity and wound healing; cardiac fibroblasts participate in scar formation after myocardial injury; liver and other organs involve activated fibroblast-like cells in fibrogenesis. Their activity is regulated by signaling pathways such as transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), fibroblast growth factors (FGFs), and by mechanical cues from the surrounding matrix.

Clinical relevance: Aberrant fibroblast activation and ECM deposition underlie fibrotic diseases that disrupt organ function. In cancer, cancer-associated fibroblasts shape the tumor microenvironment and can influence progression and therapy response. Research and therapeutic efforts target fibroblast activation, ECM production, and signaling pathways to mitigate fibrosis or to modify tumor stroma.