Interruption of endothelin signaling modifies membrane type 1 matrix metalloproteinase activity during ischemia and reperfusion.
The matrix metalloproteinases (MMPs), in particular, membrane type 1 MMP (MT1-MMP), are increased in the context of myocardial ischemia and reperfusion (I/R) and likely contribute to myocardial dysfunction. One potential upstream induction mechanism for MT1-MMP is endothelin (ET) release and subsequent protein kinase C (PKC) activation. Modulation of ET and PKC signaling with respect to MT1-MMP activity with I/R has yet to be explored. Accordingly, this study examined in vivo MT1-MMP activation during I/R following modification of ET signaling and PKC activation. With the use of a novel fluorogenic microdialysis system, myocardial interstitial MT1-MMP activity was measured in pigs (30 kg; n = 9) during I/R (90 min I/120 min R). Local ET(A) receptor antagonism (BQ-123, 1 microM) and PKC inhibition (chelerythrine, 1 microM) were performed in parallel microdialysis probes. MT1-MMP activity was increased during I/R by 122 +/- 10% (P < 0.05) and was unchanged from baseline with ET antagonism and/or PKC inhibition. Selective PKC isoform induction occurred such that PKC-betaII increased by 198 +/- 31% (P < 0.05). MT1-MMP phosphothreonine, a putative PKC phosphorylation site, was increased by 121 +/- 8% (P < 0.05) in the I/R region. These studies demonstrate for the first time that increased interstitial MT1-MMP activity during I/R is a result of the ET/PKC pathway and may be due to enhanced phosphorylation of MT1-MMP. These findings identify multiple potential targets for modulating a local proteolytic pathway operative during I/R.
Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, SC 29403, USA.
Anne M
AM
Deschamps
Juozas
J
Zavadzkas
Rebecca L
RL
Murphy
Christine N
CN
Koval
Julie E
JE
McLean
Laura
L
Jeffords
Stuart M
SM
Saunders
Nina J
NJ
Sheats
Robert E
RE
Stroud
Francis G
FG
Spinale
D000818:Animals; D065131:Endothelin B Receptor Antagonists; D016232:Endothelins / Q000502:physiology*; D005456:Fluorescent Dyes; D047468:Immunoprecipitation; D007527:Isoenzymes / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D017551:Microdialysis; D015428:Myocardial Reperfusion Injury / Q000201:enzymology / Q000503:physiopathology*; D010456:Peptides, Cyclic / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D044023:Receptor, Endothelin B / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology; D013552:Swine; D013912:Threonine / Q000378:metabolism
D065131:Endothelin B Receptor Antagonists; D016232:Endothelins; D005456:Fluorescent Dyes; D007527:Isoenzymes; D010456:Peptides, Cyclic; D044023:Receptor, Endothelin B; D013912:Threonine; D011493:Protein Kinase C; D053511:Matrix Metalloproteinase 14; C072247:cyclo(Trp-Asp-Pro-Val-Leu)