Lindsey ML, Goshorn DK, Squires CE, Escobar GP, Hendrick JW, Mingoia JT, Sweterlitsch SE, Spinale FG. Age-dependent changes in myocardial matrix metalloproteinase/tissue inhibitor of metalloproteinase profiles and fibroblast function.
Cardiovasc Res 2005;
66:410-9. [PMID:
15820210 DOI:
10.1016/j.cardiores.2004.11.029]
[Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 11/03/2004] [Accepted: 11/24/2004] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE
To evaluate the effects of aging on left ventricular (LV) geometry, collagen levels, matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) abundance, and myocardial fibroblast function.
METHODS
Young (3-month-old; n=28), middle-aged (MA; 15-month-old; n=17), and old (23-month-old; n=16) CB6F1 mice of both sexes were used in this study. Echocardiographic parameters were measured; collagen, MMP, and TIMP levels were determined for both the soluble and insoluble protein fractions; and fibroblast function was evaluated.
RESULTS
LV end-diastolic dimensions and wall thickness increased in both MA and old mice, accompanied by increased soluble protein and decreased insoluble collagen. Immunoblotting revealed differential MMP/TIMP profiles. Compared to MA levels, MMP-3, MMP-8, MMP-9, MMP-12, and MMP-14 increased, and TIMP-3 and TIMP-4 decreased in the insoluble fraction of old mice, suggesting increased extracellular matrix (ECM) degradative capacity. Fibroblast proliferation was blunted with age.
CONCLUSION
This study, for the first time, identified specific differences in cellular and extracellular processes that likely contribute to age-dependent ECM remodeling.
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