A membrane-type matrix metalloproteinase, termed MT1-MMP, acts as the dominant pericellular collagenase during adipose tissue development (Chun et al., Cell 2006). MT1-MMP-null mice harbor a heretofore unrecognized, and major, defect in the development of adipose tissue and succumb to premature death. Despite the ability of MT1-MMP-null adipocyte precursor cells to fully differentiate into functional adipocytes under a 2-D in vitro condition, they are unable to engage adipogenic program in a 3-D collagenous microenvironment, which recapitulates an in vivo setting. High-calorie diet and hyperinsulinemia together increase adipose tissue mass. Both the expansion of adipocyte size and de novo adipogenesis contribute to the expansion of adult adipose tissue mass. Given the role of MT1-MMP in development, we ask a question whether the collagenolytic tissue remodeling contributes to obesity progression in the adult. As such, the applicant initiated a series of experiments to investigate the role of MT1-MMP-dependent collagenolysis in high fat-induced obesity and its molecular link to insulin signaling. Preliminary data suggest that the haploinsufficiency of MT1-MP substantially decreases high-fat induced weight gain (?50%). Further, human MT1-MMP gene polymorphisms are found to modify collagenolytic activity and human obesity. Thus, MT1-MMP-dependent proteolytic tissue remodeling is considered as a process critical for the regulation of obesity and metabolism in the adult. This research project will focus on identifying the role of MT1-MMP in regulation of collagenolysis, adipose tissue mass, and glucose metabolism in obesity progression. Moreover, the molecular mechanisms of 3-D adipocyte differentiation will be dissected and characterized by examining the spatial, temporal link of MT1-MMP-dependent collagenolysis to insulin signaling and adipocyte function. This should provide a unique perspective for understanding the molecular mechanisms of the tissue remodeling that regulates the progression of obesity and the consequent deterioration of cardiovascular system.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08DK078801-02
Application #
7759594
Study Section
Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK)
Program Officer
Hyde, James F
Project Start
2009-09-01
Project End
2012-08-31
Budget Start
2010-09-01
Budget End
2011-08-31
Support Year
2
Fiscal Year
2010
Total Cost
$133,758
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Chun, Tae-Hwa (2012) Peri-adipocyte ECM remodeling in obesity and adipose tissue fibrosis. Adipocyte 1:89-95
Sato-Kusubata, Kaori; Jiang, Yibin; Ueno, Yoko et al. (2011) Adipogenic histone mark regulation by matrix metalloproteinase 14 in collagen-rich microenvironments. Mol Endocrinol 25:745-53
Chun, Tae-Hwa; Inoue, Mayumi; Morisaki, Hiroko et al. (2010) Genetic link between obesity and MMP14-dependent adipogenic collagen turnover. Diabetes 59:2484-94