New Insights into MMP function in Adipogenesis

Abstract

Matrix metalloproteinases (MMPs) mediate homeostasis of the extracellular environment. This equilibrium is modified and/or altered during normal (adipocyte differentiation, mammary gland involution, wound healing) or pathological (obesity, cancer) biological processes. While the role of MMPs is well known during tissue involution, wound healing, and cancer, their implication during adipogenesis has just begun to unfold. Although not designed to be comprehensive, this chapter provides in vitro and in vivo evidence that matrix degradation is essential for adipogenesis, and that the proteolytic activity of MMPs is critical for adipose tissue development. Moreover, obesity is currently a sign of poor prognosis in various human carcinomas. In this context, the involvement of MMP11 in adipocyte-cancer cell interaction/cross talk during the early invasive steps of carcinomas provides evidence that the MMP system participates in this process, and highlights a new link between obesity and cancer. How adipocytes and MMPs might cooperate to favor tumor progression, and notably the possible role of adipokines and adipose tissue angiogenesis, will be discussed.