Mechanisms through which sympathetic nervous system inhibitors mobilise hepatic stem cells in non alcoholic fatty liver disease. (360G-Wellcome-077090_Z_05_A)

Background: Non alcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease in the West. The main risk factors for the development of NAFLD are obesity and type 2 diabetes. Animal models of NAFLD have steatotic, inflamed livers with inhibited hepatocyte replication and increased oval cell (OC) numbers as occurs in human NAFLD. OC are facultative bi-potential liver-resident stem cells which can differentiate into hepatocytes if the mature hepatocytes reach a critically low number, or if the mature hepatocytes are prevented from dividing by hepatotoxic drugs or disease. My earlier experiments with models of NAFLD showed that sympathetic nervous system (SNS) inhibitors such as prazosin, an a-1 adrenoceptor antagonist, or 6-hydroxydopamine increase OC numbers, with resultant reduced liver injury and an enhanced regenerative response. We have also shown that hepatic stellate cells (HSC) - the liver's principal fibrogenic cells, are also regulated by the SNS. The mechanisms through which the SNS regulate OC and HSC are, however, not known.