A functional role of gelatinase A in the development of nutritionally induced obesity in mice.
BACKGROUND
Development of adipose tissue is a complex process involving adipogenesis, angiogenesis and proteolytic remodeling of the extracellular matrix. The matrix metalloproteinase (MMP) system plays an important role in these processes.


OBJECTIVE
To establish a functional role of gelatinase A (MMP-2) in the development of adipose tissue.


METHODS
Mice with genetic deficiency in gelatinase A (MMP-2(-/-)) and their wild-type littermates (MMP-2(+/+)), as well as wild-type mice treated with a gelatinase inhibitor, were kept on a high-fat diet (HFD) for 15 weeks, and this was followed by analysis of weight and composition of the fat pads.


RESULTS
MMP-2(-/-) mice gained significantly (P < 0.05) less weight on the HFD than MMP-2(+/+) mice, resulting in lower body weights (P < 0.0005). The weights of the isolated subcutaneous and gonadal adipose tissues were also significantly lower (P < 0.005 and P < 0.0005, respectively). Immunohistochemical analysis revealed significant (P < 0.05) adipocyte hypotrophy in both fat pads. Treatment of wild-type mice with the gelatinase inhibitor Tolylsam resulted in an approximately 15% reduction of body weight (P < 0.0001) and significantly lower subcutaneous and gonadal adipose tissue mass, associated with adipose hypotrophy (all P < 0.0001).


CONCLUSIONS
Deficiency of MMP-2 impairs adipose tissue development in mice by contributing to adipocyte hypotrophy.
Van Hul
M
M
Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium.
Lijnen
H R
HR
D017667:Adipocytes / Q000166:cytology; D000273:Adipose Tissue / Q000254:growth & development; D000818:Animals; D050218:Body Fat Distribution; D001835:Body Weight; D020778:Matrix Metalloproteinase 2 / Q000172:deficiency / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009765:Obesity / Q000209:etiology*
D020778:Matrix Metalloproteinase 2