Chymase Inhibition Prevents Fibronectin and Myofibrillar Loss and Improves Cardiomyocyte Function and LV Torsion Angle in Dogs with Isolated Mitral Regurgitation.
Publication/Presentation Date
10-12-2010
Abstract
BACKGROUND: The left ventricular (LV) dilatation of isolated mitral regurgitation (MR) is associated with an increase in chymase and a decrease in interstitial collagen and extracellular matrix. In addition to profibrotic effects, chymase has significant antifibrotic actions because it activates matrix metalloproteinases and kallikrein and degrades fibronectin. Thus, we hypothesize that chymase inhibitor (CI) will attenuate extracellular matrix loss and LV remodeling in MR.
METHODS AND RESULTS: We studied dogs with 4 months of untreated MR (MR; n=9) or MR treated with CI (MR+CI; n=8). Cine MRI demonstrated a >40% increase in LV end-diastolic volume in both groups, consistent with a failure of CI to improve a 25% decrease in interstitial collagen in MR. However, LV cardiomyocyte fractional shortening was decreased in MR versus normal dogs (3.71±0.24% versus 4.81±0.31%; P
CONCLUSIONS: These results suggest that chymase disrupts cell surface-fibronectin connections and FAK phosphorylation that can adversely affect cardiomyocyte myofibrillar structure and function. The greater effect of CI on epicardial versus endocardial titin and noncollagen cell surface proteins may be responsible for the increase in torsion angle in chronic MR.
Volume
122
Issue
15
First Page
1488
Last Page
1495
ISSN
1524-4539
Published In/Presented At
Pat, B., Chen, Y., Killingsworth, C., Gladden, J. D., Shi, K., Zheng, J., & ... Dell'italia, L. J. (2010). Chymase inhibition prevents fibronectin and myofibrillar loss and improves cardiomyocyte function and LV torsion angle in dogs with isolated mitral regurgitation. Circulation, 122(15), 1488-1495. doi:10.1161/CIRCULATIONAHA.109.
Disciplines
Cardiology | Medical Sciences | Medical Specialties | Medicine and Health Sciences
PubMedID
20876440
LVHN link
http://search.ebscohost.com/login.aspx?direct=true&db=mnh&AN=20876440&site=ehost-live&scope=site
Department(s)
Department of Medicine, Department of Medicine Faculty, Department of Medicine Fellows and Residents
Document Type
Article