Figure 5.

Pathways of hepatic stellate cell activation including those contributing to initiation and perpetuation. Initiation is provoked by soluble stimuli that include oxidant stress signals, apoptotic bodies, lipopolysaccharide, and cytokine stimuli from neighbouring cells. Perpetuation is characterised by specific phenotypic changes including proliferation, contractility, fibrogenesis, altered matrix degradation, chemotaxis, and cytokine signalling. Reproduced with permission from Friedman[30]. CTGF: Connective tissue growth factor; ET: Endothelin; FGF: Fibroblast growth factor; LPS: Lipopolysaccharide; MMP: Matrix metalloproteinase; MT-1: membrane type-1, NK: Natural killer, NO: Nitrous oxide; PDGF: Platelet derived growth factor; TIMP: Tissue inhibitor of metalloproteases; TGF: Transforming growth factor; TLR: Toll like receptor; TRAIL: Tumour necrosis factor-related apoptosis-inducing ligand; VEGF: Vascular endothelial growth factor.