Abstract
Background: Trabeculation is an integral component of cardiac ventricular morphogenesis and is dependent on the matrix metalloproteinase, ADAMTS1. A substrate of ADAMTS1 is the proteoglycan versican which is expressed in the developing ventricle and which has been implicated in trabeculation. Fibulin-1 is a versican and ADAMTS1-binding extracellular matrix protein required for ventricular morphogenesis. Here we investigated the involvement of fibulin-1 in ADAMTS1-mediated cleavage of versican in vitro, and the involvement of fibulin-1 in versican cleavage in ventricular morphogenesis. Results: We show that fibulin-1 is a cofactor for ADAMTS1-dependent in vitro cleavage of versican V1, yielding a 70-kDa amino-terminal fragment. Furthermore, fibulin-1-deficiency in mice was found to cause a significant reduction (>90%) in ventricular levels of the 70-kDa versican V1 cleavage product and a 2-fold increase in trabecular cardiomyocyte proliferation. Decreased versican V1 cleavage and augmented trabecular cardiomyocyte proliferation in fibulin-1 null hearts is accompanied by increased ventricular activation of ErbB2 and Erk1/2. By contrast, versican deficiency was found to lead to decreased cardiomyocyte proliferation and reduced ventricular trabeculation. Conclusion: We conclude that fibulin-1 regulates versican-dependent events in ventricular morphogenesis by promoting ADAMTS1 cleavage of versican leading to suppression of trabecular cardiomyocyte proliferation mediated by the ErbB2-Map kinase pathway.
Original language | English (US) |
---|---|
Pages (from-to) | 303-314 |
Number of pages | 12 |
Journal | Developmental Dynamics |
Volume | 241 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2012 |
Externally published | Yes |
Keywords
- ADAMTS-1
- Brg1
- Cardiomyocyte
- DPEAAE
- ErbB2
- Erk1/2
- Fbln1
- Fibulin-1
- Knockout
- Trabeculation
- Ventricular noncompaction
- Versican
ASJC Scopus subject areas
- Developmental Biology