Figure 2

CTGF is a central mediator of tissue remodeling and fibrosis. Many different stimuli can induce expression of CTGF, which then promotes formation of myofibroblasts by modulating differentiation of other cells, including epithelial cells (EMT, epithelial to mesenchymal transition), resident fibroblasts or recruited fibrocytes (bone-marrow-derived, circulating mesenchymal stem cells). CTGF also promotes activation of the myofibroblasts and stimulates extracellular matrix (ECM) deposition and tissue remodeling. Remodeling in the vasculature can produce local hypertension that induces the expression of more CTGF, resulting in a positive feedback loop. Other positive feedback loops result from cytokines whose expression may be stimulated by CTGF, that in turn induce the expression of CTGF.