Cyclic strain-mediated regulation of endothelial matrix metalloproteinase-2 expression and activity.
OBJECTIVE
To investigate the role of cyclic strain in controlling matrix metalloproteinase-2 (MMP-2) expression and activity in endothelial cells (ECs) in vitro.


METHODS
A Flexercell Tension Plus FX-4000T system was used to apply a physiological level of equibiaxial cyclic strain (0-10% strain, 60 cycles/min, 0-24 h, cardiac waveform) to bovine aortic endothelial cells (BAECs). Cells and conditioned media were harvested for analysis of MMP-2/9 expression and activity (pro and active) using reverse-transcriptase polymerase chain reaction (RT-PCR), Western blotting and zymography techniques.


RESULTS
Cyclic strain significantly increased MMP-2 expression and activity force- and time-dependently. Pretreatment with Gialpha-protein inhibitors, pertussis toxin (PTX) and NF023, transient expression of inhibitory mutants of Gialpha-subunits, or pretreatment with RGD peptides to block RGD-dependent integrin signaling failed to attenuate strain-induced increases in MMP-2 expression in BAECs. In contrast, inhibition of Gbetagamma-signaling with betaArk-ct or tyrosine kinase blockade with genistein reduced strain-induced MMP-2 expression while concomitantly inhibiting strain-induced p38 and ERK activity in these cells. Pretreatment with PD169316 and PD98059 to selectively inhibit p38 and ERK activity, respectively, also resulted in a significant inhibition of the strain-induced MMP-2 response. Finally, inhibition of the adaptor protein, Shc, (via Shc-SH2 transfection) resulted in a significant decrease in strain-induced MMP-2 activity concomitant with a reduction in ERK activity in BAECs.


CONCLUSIONS
Cyclic strain stimulates MMP-2 expression, in part, by stimulating both p38- and ERK-dependent pathways through activation of Gbetagamma and tyrosine kinase in BAECs.
von Offenberg Sweeney
Nicholas
N
Vascular Health Research Centre, Faculty of Science and Health, Dublin City University, Glasnevin, Dublin 9, Ireland.
Cummins
Philip M
PM
Birney
Yvonne A
YA
Cullen
John P
JP
Redmond
Eileen M
EM
Cahill
Paul A
PA
D000818:Animals; D001011:Aorta; D002417:Cattle; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000201:enzymology*; D004730:Endothelium, Vascular / Q000201:enzymology*; D019204:GTP-Binding Proteins / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D011673:Pulsatile Flow; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical; D048051:p38 Mitogen-Activated Protein Kinases
D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020778:Matrix Metalloproteinase 2; D019204:GTP-Binding Proteins