Matrix metalloproteinase 11 protects from diabesity and promotes metabolic switch

1 MMP11 overexpression is a bad prognostic factor in various human carcinomas. Interestingly, this proteinase is not expressed in malignant cells themselves but is secreted by adjacent non-malignant mesenchymal/stromal cells, such as cancer associated fibroblasts (CAFs) and adipocytes (CAAs), which favors cancer cell survival and progression. As MMP11 negatively regulates adipogenesis in vitro, we hypothesized that it may play a role in whole body metabolism and energy homeostasis. We used an in vivo gain-(Mmp11-Tg mice) and loss-(Mmp11−/− mice) of-function approach to address the systemic function of MMP11. Strikingly, MMP11 overexpression protects against type 2 diabetes while Mmp11−/− mice exhibit hallmarks of metabolic syndrome. Moreover, Mmp11-Tg mice were protected from diet-induced obesity and display mitochondrial dysfunction, due to oxidative stress, and metabolic switch from oxidative phosphorylation to aerobic glycolysis. This Warburg-like effect observed in adipose tissues might provide a rationale for the deleterious impact of CAA-secreted MMP11, favouring tumor progression. MMP11 overexpression also leads to increased circulating IGF1 levels and the activation of the IGF1/AKT/FOXO1 cascade, an important metabolic signalling pathway. Our data reveal a major role for MMP11 in controlling energy metabolism, and provide new clues for understanding the relationship between metabolism, cancer progression and patient outcome. More and more epidemiological data attribute a pernicious effect to metabolic disorders, notably obesity and diabetes , on cancer progression. Moreover, metformin, a drug commonly administered for type 2 diabetes, displays antitumor properties 1. To date, most studies have emphasized tumor aggressiveness in a context of already constituted metabolic disorders. Less attention has been given to the ability of cancer cells to impact on metabolism via molecules abnormally expressed by primary tumors and/or metastases. This effect may be of interest and should therefore be evaluated to unravel the link between metabolism and cancer. Matrix metalloproteinase 11 (MMP11; previously named stromelysin-3) 2