New insight of obesity-associated NAFLD: Dysregulated "crosstalk" between multi-organ and the liver?

Obesity plays a crucial role in the development of non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanism for the pathogenesis of obesity-associated NAFLD remains largely obscure. Although the "multiple hit" theory provides a more accurate explanation of NAFLD pathogenesis, it still cannot fully explain precisely how obesity causes NAFLD. The liver is the key integrator of the body's energy needs, receiving input from multi-ple metabolically active organs. Thus, recent studies have advocated the "multiple crosstalk" hypothesis, highlighting that obesity-related hepatic steatosis may be the result of dysregu-lated "crosstalk" among multiple extra-hepatic organs and the liver in obesity. A wide variety of circulating endocrine hormones work together to orchestrate this "crosstalk". Of note, with deepening understanding of the endocrine system, the perception of hormones has gradually risen from the narrow sense (i.e. traditional hormones) to the broad sense of hormones as or-ganokines and exosomes. In this review, we focus on the perspective of organic endocrine hor-mones (organokines) and molecular endocrine hormones (exosomes), summarizing systematically how the two types of new hormones mediate the dialogue between extra -hepatic organs and liver in the pathogenesis of obesity-related NAFLD. 2022 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).