Fig. 5.

Overview of leptin actions in the adipose organ. Leptin exerts central actions, modulating energy homeostasis and influencing multiple endocrine actions, and peripheral actions in different tissues. In the adipose organ, leptin exerts key regulatory actions through direct or indirect mechanisms, with short/medium- and long-term implications. Leptin promotes adipogenesis, lipolysis, fatty acid oxidation, apoptosis, browning, and stimulates BAT thermogenesis. At high concentrations, leptin also stimulates the production of pro-inflammatory cytokines and promotes inflammation. Moreover, during critical windows of development, leptin may exert central neurotrophic actions, affecting leptin-sensitive brain circuits involved in adipose tissue regulation, which can lead to morphological and physiological changes in the adipose tissue, with long-lasting consequences for later function and metabolic health. Therefore, adequate amounts of leptin during the perinatal period, both during the foetal and suckling periods, seem to be essential for the proper development of the adipose organ and may also compromise later leptin action. A better understanding of the mechanisms and actions of leptin in the adipose organ, as well as in other target tissues, may lead to new approaches in obesity prevention and treatment since the early stages of life