SIGNAL-TRANSDUCTION IN HEPATIC STELLATE CELLS

Hepatic stellate cells (HSC) are presently regarded as one of the key cell types involved in the progression of liver fibrosis and in the re lated pathophysiological and clinical complications. Following acute o r chronic liver tissue damage, HSC undergo a process of activation tow ards a phenotype characterised by increased proliferation, motility, c ontractility and synthesis of extracellular matrix (ECM) components. S everal factors have been shown to play a key role in the promotion of the full-blown picture of activated HSC. These include extensive chang es in the composition and organisation of the ECM, the secretion of se veral growth factors, cytokines, chemokines, products of oxidative str ess and other soluble factors. It is evident that each cellular respon se to extracellular stimuli must be framed in a scenario where differe nt forces modulate one another and result in a prevalent biological ef fect. Along these lines, the identification and characterisation of in tracellular signalling pathways activated by different stimuli in HSC represent a mandatory step. In this review article we have made an att empt to summarise recent acquisitions to our knowledge of the involvem ent of different intracellular signalling pathways in key aspects of H SC biology.