NTU Undergraduates' research April 2014 - Biosciences | Página 35

IN VITRO SIMULATION OF RENAL INJURY
MEASUREMENT OF TRANSFORMING GROWTH FACTOR-β1 AND ROLE OF
PROTEIN CROSS-LINKING ENZYME TISSUE TRANSGLUTAMINASE

by

SONIA DA COSTA FERNANDES

Abstract

Normal tissue remodeling and repair processes in the kidney involves synthesis and
deposition of ECM components collagen type I and II, fibronectin and laminin by mesangial
cells, myofibroblasts and tubules as a result of TGF-β1 signaling. TGF-β1 requires
activation in order to mediate its physiological function. TG2, is an ECM crosslinking
protein which mediates cell-matrix adhesion, crosslinking of ECM fibrils and binds to TGFβ1 LTBP, thus localizing the cytokine to the area where appropriate stimuli will result in its
rapid activation. Since deposition of elevated levels of extracellular matrix (ECM) proteins
in the tubulointerstitial areas of the kidney is a key feature of progressive renal disorders
and ultimately causes renal failure, this experiment aims to confirm that active TGF-β1 is
elevated in a normal rat renal proximal tubular cell line (NRK52 E) during cell wounding, in
the presence of ROS species and in a cyslosporine A (CsA) – mediated renal fibrosis model,
and that the presence of exogenous tTG may induce TGF-β1 activation and augment the
wounding healing process of physically disrupted cell.