NTU Undergraduates' research April 2014 - Biosciences | Page 107

Activation of Latent Transforming Growth Factor-β upon
cellular wounding in a model of renal tubular epithelial cells
The process of wound healing is elicited immediately after an injury, recruits several different cell
types whereby cross communication is achieved through the release of numerous cytokines, which is
further enhanced during the inflammatory response. Transforming Growth Factor- β (TGF-β) has
been identified as a critical pro-fibrotic cytokine which becomes locally induced upon injury. The
activation of TGF-β is a tightly controlled mechanism which involves numerous potential activators,
although the exact mechanism of each activator is yet to be fully understood . Once activated. TGF-β
has the ability to induce cellular regeneration and influence gene express-ion, bringing about the
synthesis of various matrix components such as collagen, fibronectin and deposition of extracellular
matrix (ECM), thus inducing closure of the wound.
Using mink lung cells transfected with the plasminogen activator inhibitor-1 promoter luciferase
construct (PA1-L) we were able to quantify active and total TGF-β1 induced by a cell wounding
model of renal tubular epithelial cells. We found that wounding of the cell monolayer induces the
activation of TGF-β1 in tubular epithelial cells, supporting the findings of activation upon injury.