Inflammasomes in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a leading liver disorder in the world. Inflammation is one of the most important pathological events during the development of NAFLD and also represents the hallmark between simple steatosis and non-alcoholic steatohepatitis (NASH). Inflammasomes are novel protein complex platforms assembled in response to pattern-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Currently, there are several identified inflammasomes, including nod-like receptor protein (NLRP)-1, 2, 3, 6, 10, 12, NLRC4 and absent in melanoma 2 (AIM2) inflammasomes. In the liver, inflammasomes are primarily expressed in immune cells. However, increasing evidence suggests that their expressions in other types of cells in the liver are also present. In general, inflammasomes are up-regulated in various liver diseases. In NAFLD, it is reported that the levels of inflammasome components (e.g. NLRPs, caspase-1, IL-1beta and IL-18) are elevated. Silence of these components attenuates hepatic injury. Collectively, the main purposes of this review are to examine the recent progress of hepatic inflammasome research and to discuss possible directions of therapeutic strategy and development against NAFLD.