Figure 2.

Leptin actions in white adipose tissue. White adipose tissue (WAT) is composed of by adipocytes, among other cells types. White adipocytes are cells with capacity to store lipids in a large droplet. WAT adipose tissue is more than a reservoir, as it also serves as an endocrine organ that produce and release several adipocytokines with effects in obesity, including leptin. Leptin has several effects in WAT, in direct or indirect mechanisms. Thus, leptin can promote adipogenesis, lipolysis or browning in this tissue. Recently, leptin actions in immune system have sparked the interest in the field; briefly, this hormone stimulates the production of pro-inflammatory cytokines and it is implicated in adipose tissue macrophages (ATMs) polarization. Also, leptin stimulates the apoptotic adipocyte process, another promising area since fat loss could be achieved by decreasing the number of adipocytes through apoptosis.