The adipocyte as an endocrine cell

Abstract

Adipose tissue contains many cell types. Among the more abundant are adipocytes, preadipocytes, immune cells, and endothelial cells. During times of excess caloric intake, these cells have to adjust and remodel to accommodate the increased demand for triglyceride storage. Based on a comprehensive analysis of the total adipose tissue secretome, this article focuses on three areas of adipokine biology: (1) How does the adipocyte interact with the extracellular matrix over the course of obesity? (2) Does the adipocyte, per se, play a role in the innate immune response? (3) How is the angiogenic profile of adipose tissue linked to the development of insulin resistance? The authors present a comprehensive overview of all of the currently available secreted adipose tissue products that have been identified at the protein level.

Figure 1. Cartoon representation of white adipose tissue in the lean (left) vs. obese (right) state

Adipocytes are shown with yellow triglyceride droplets and blue cytoplasm. In the lean state the light blue cytoplasm represent a state of normoxia, whereas the dark blue in the obese state represents a hypoxic state. Pre adipocytes are shown in brown, macrophages in green, blood vessels/endothelial cells in red, and the extracellular matrix as black.