Interruption of endothelin signaling modifies membrane type 1 matrix metalloproteinase activity during ischemia and reperfusion

Abstract

Deschamps AM, Zavadzkas J, Murphy RL, Koval CN, McLean JE, Jeffords L, Saunders SM, Sheats NJ, Stroud RE, Spinale FG. Interruption of endothelin signaling modifies membrane type 1 matrix metalloproteinase activity during ischemia and reperfusion. Am J Physiol Heart Circ Physiol 294: H875-H883, 2008. First published December 7, 2007 doi:10.1152/ajpheart.00918.2007.-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 ϭ 9) during I/R (90 min I/120 min R). Local ET A receptor antagonism (BQ-123, 1 M) and PKC inhibition (chelerythrine, 1 M) were performed in parallel microdialysis probes. MT1-MMP activity was increased during I/R by 122 Ϯ 10% (P Ͻ 0.05) and was unchanged from baseline with ET antagonism and/or PKC inhibition. Selective PKC isoform induction occurred such that PKC-␤II increased by 198 Ϯ 31% (P Ͻ 0.05). MT1-MMP phosphothreonine, a putative PKC phosphorylation site, was increased by 121 Ϯ 8% (P Ͻ 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. myocardial interstitium; microdialysis; protein kinase C; phosphorylation; ischemia-reperfusion TRANSIENT LEFT VENTRICULAR (LV) dysfunction and changes in the myocyte-matrix interface occur with ischemia-reperfusion (I/R) (7,8,48). Matrix metalloproteinases, or MMPs, are a family of extracellular matrix (ECM) degrading enzymes that have been implicated in this process (23, 37). One specific MMP, membrane type-1 matrix metalloproteinase (MT1-MMP), has been shown previously to be increased in human heart failure, and interstitial activation of MT1-MMP is induced with periods of I/R (3, 10, 30, 38). MT1-MMP is a significant MMP family member due to the fact that it has multiple functions, including local ECM degradation, activation of other MMP family members, and processing of other bioactive molecules, including growth factors and cytokines (13,19,25). In light of MT1-MMP's pleiotropic proteolytic capabilities, activation of this enzyme may influence myocardial biology with I/R. Biological stimuli operative in the setting of I/R can potentially influence MT1-MMP posttranslational states and activity. For example, cytokines, oxidative stress, and endot...

ETAselective receptor antagonism prevents ventricular remodeling in volume-overloaded rats

“…A potential connection between ET-1 and MMP induction in pathological disease states has been observed from investigations of tumor cell invasion, cancerous growth, arthritis, and vascular remodeling (1, 2, 5, 45, 46). The recent study by Deschamps et al (17) found ET A selective receptor antagonism attenuated the ET-1-mediated increase in membrane type 1 MMP activity following ischemia-reperfusion. However, this study did not address changes in overall LV function secondary to ET-1-mediated myocardial remodeling.…”

Heterogeneity in MT1-MMP activity with ischemia-reperfusion and previous myocardial infarction: relation to regional myocardial function

“…A sterile microdialysis probe containing a 4-mmlong membrane (20 kDa, CMA/Microdialysis, North Chelmsford, MA) was placed into the LV midmyocardium in two regions: the main region served by the first and second obtuse marginal branches of the LCx (LCx region) and the region served by the diagonal branches of the LAD (LAD region). These microdialysis probes have been successfully placed in the LV of animals and patients previously to measure local bioactive signaling and MMP activity (5,6,22,38). Moreover, it has been demonstrated that this surgical approach for placement of the microdialysis probe was not associated with alterations in blood flow or extravasation of red blood cells, did not change local bioactive peptide levels, and was not associated with an acute inflammatory response (5,6).…”

“…One of the best-characterized and prototypical membrane type MMPs is membrane type-I MMP (MT1-MMP), which has been reported to be increased in abundance and activity in the context of I/R (5). Moreover, studies (3,6) have established that MT1-MMP is induced by upstream bioactive molecules such as PKC and endothelin. However, whether and to what degree MT1-MMP is induced within the remote region before I/R, and whether it would be increased in magnitude after the I/R event, remain to be demonstrated.…”

Effects of nonselective endothelin-1 receptor antagonism on cardiac mast cell-mediated ventricular remodeling in rats

“…Initial cleavage of collagen by collagenase is necessary in order for gelatinases to complete degradation. Thus it is possible that other MMPs, including collagenases, may continue to be affected in the bosentan-treated AV fistula hearts (10,12). Regardless, it would appear that this relative protection against adverse extracellular matrix remodeling persisted beyond the acute effects of ET-1 antagonism on MMP activation, given the attenuated LV chamber dilatation seen in the 14-day bosentan-treated group.…”