The Extracellular Matrix Protein MAGP1 Is a Key Regulator of Adipose Tissue Remodeling During Obesity

In response to increases in fat mass, as seen in obesity, the adipose tissue undergoes distinct structural remodeling (1). Recent attention has focused on the importance of the extracellular matrix (ECM) in remodeling of adipose tissue during the development of obesity. The ECM not only provides structural support to the surrounding cells, but also plays a crucial role in the biological function of different organs. Components of the ECM include structural proteins, such as collagen and fibrillins, and various classes of adhesion proteins, such as fibronectin and proteoglycan. Fibrillins are large proteins that form extracellular microfibril suprastructures ubiquitously found in elastic and nonelastic tissues. Constitutive components of the microfibrils also include the microfibril-associated glycoproteins (MAGPs) 1 and 2 (2,3). Microfibrils appear to have dual roles: They confer mechanical stability and limited elasticity to tissues and modulate the activity of members of the transforming growth factor-β (TGF-β) superfamily (4–6). The importance of microfibrils in regulating TGF-β activity is illustrated by the phenotype associated …