Down-regulation of tissue inhibitor of metalloproteinase-3 (TIMP-3) expression is necessary for adipocyte differentiation.

Authors:
Bernot D, Barruet E, Poggi M, Bonardo B, Alessi MC, Peiretti F.
In:
Source: J Biol Chem
Publication Date: (2010)
Issue: 285(9): 6508-14
Research Area:
Basic Research
Cells used in publication:
Adipocyte (pre), human
Species: human
Tissue Origin: adipose
3T3-L1 ad
Species: mouse
Tissue Origin: embryo
Embryonic fibroblast, mouse (MEF)primary
Species: mouse
Tissue Origin: embryo
Platform:
Nucleofector™ I/II/2b
Abstract
Matrix metalloproteinase activity is essential for proper extracellular matrix remodeling that takes place during adipose tissue formation. Four tissue inhibitors of matrix metalloproteinases (TIMPs) regulate their activity. However, the role of TIMPs in adipocyte differentiation is poorly understood. We found that the expression of all TIMPs was modified during adipocyte differentiation, but that of TIMP-3 was distinguished by its extreme down-regulation. TIMP-3 expression was closely linked to the differentiation process. Indeed, it remained low during the adipocyte differentiation but increased when cell differentiation was prevented. We identified the transcription factor Sp1 as being responsible for the regulation of TIMP-3 expression during adipocyte differentiation. Overexpression of TIMP-3 reduced adipocyte differentiation, underlining its active role in this process. TIMP-3 overexpression decreased the expression of the early and obligate key inductors of adipogenesis KrĂĽppel-like factor 4 (Klf4), early growth response 2 (Egr2/Krox20), and CAAT/enhancer-binding protein beta (C/EBPbeta). Our results indicate that during preadipocyte differentiation, the Sp1-dependent decrease in TIMP-3 expression is required for the successful implementation of the adipocyte differentiation program.