In a healing skin wound, fibroblast proliferation and collagen deposition begin around day 3 and peak in the second week. Which cytokine is the most potent stimulator of fibroblast migration, proliferation and extracellular matrix synthesis at this stage?

• A Interferon gamma
• B Tumor necrosis factor alpha
• C Interleukin-4
• D Transforming growth factor beta ✓

Explanation

TGF-beta, released by platelets, macrophages and T cells, is the most fibrogenic cytokine known: it recruits fibroblasts, stimulates collagen, fibronectin and proteoglycan synthesis, and inhibits matrix degradation by reducing metalloproteinases and increasing tissue inhibitors of metalloproteinases. Interferon gamma and TNF-alpha actually inhibit fibroblast proliferation and collagen synthesis, which is why they can be antifibrotic in granulomatous disease.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.