Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 275, Issue 27, Pages 20355-20360Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M001660200
Keywords
-
Categories
Funding
- NHLBI NIH HHS [HL 35753] Funding Source: Medline
Ask authors/readers for more resources
Expression of the brain natriuretic peptide (BNP) gene in cultured neonatal rat ventricular myocytes is activated by mechanical strain in vitro. We explored the role of cell-matrix contacts in initiating the strain-dependent increment in human BNP (hBNP) promoter activity. Coating the culture surface with fibronectin effected a dose-dependent increase in basal hBNP luciferase activity and amplification of the response to strain. Preincubation of myocytes with an RGD peptide (GRGDSP) or with soluble fibronectin, each of which would be predicted to compete for cell-matrix interactions, resulted in a dose dependent reduction in strain-dependent hBNP promoter activity. A functionally inert RGE peptide (GRGESP) was without effect. Using fluorescence-activated cell sorting, we demonstrated the presence of beta(1), beta(3), and alpha(V)beta(5) integrins in myocytes as well as non-myocytes and alpha 1 only in non-myocytes in our cultures. Inclusion of antibodies directed against beta(1), beta(3), or alpha(V)beta(5) but not alpha(1), alpha(2), or cadherin, was effective in blocking the BNP promoter response to mechanical strain. These same antibodies (anti-beta(3), -beta(1), and -alpha(V)beta(5)) had a similar inhibitory effect on strain-stimulated ERK, p38 MAPK, and, to a lesser extent, JNK activities in these cells. Cotransfection with chimeric integrin receptors capable of acting as dominant-negative inhibitors of integrin function demonstrated suppression of strain-dependent BNP promoter activity when vectors encoding beta(1) or beta(3), but not beta(5), alpha(5), or a carboxyl-terminal deletion mutant of beta(3) (beta(3)B), were employed. These studies underscore the importance of cell-matrix interactions in controlling cardiac gene expression and suggest a potentially important role for these interactions in signaling responses to mechanical stimuli within the myocardium.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available