Adiponectin’s roles in lipid and glucose metabolism modulation in fish: Mechanisms and perspectives

Abstract Glucose and lipid metabolisms are central in determining the growth and the health status of cultured fish and thus are of pivotal interest for modern aquaculture. Adiponectin is a fat‐derived hormone that plays a vital role in glucose and lipid homeostasis. While abundant knowledge is available on adiponectin in mammals, less is known in fish, though it has been documented that adiponectin is certainly important in the modulation of teleosts’ lipid and glucose metabolism too. Adiponectin exerts its metabolic effects via two receptors, AdipoR1 and AdipoR2, which then, in a tissue‐dependent manner, initiate a series of signal transduction events, eventually resulting in increased glucose utilization and fatty acid β‐oxidation. In teleosts, adiponectin and its receptors genes were first identified in zebrafish in 2008, and since then, increasing numbers of adiponectin and its receptors have been cloned in a variety of cultured fish species. This review attempts to provide the first, thorough overview of the discovery and identification of adiponectin, its receptors and their expression, regulation and signal transduction in fish. Then, the potential effects and mechanisms of adiponectin on energy (lipid and glucose) homeostasis are described, before concluding on possible therapeutic approaches to enhance adiponectin actions. It is envisaged that the present work will contribute, first, to knowledge gain in the evolution of energy homeostasis in vertebrates, and then, to provide a much‐needed additional theoretical fundament for a healthier and further performance‐improved aquaculture.