Dataset Information

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

ABSTRACT: 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.

SUBMITTER: Deschamps AM

PROVIDER: S-EPMC2663358 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

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

Deschamps Anne M AM Zavadzkas Juozas J Murphy Rebecca L RL Koval Christine N CN McLean Julie E JE Jeffords Laura L Saunders Stuart M SM Sheats Nina J NJ Stroud Robert E RE Spinale Francis G FG

American journal of physiology. Heart and circulatory physiology 20071207 2

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 ...[more]

PMID: 18065523

Similar Datasets

Project description:Membrane type 1 matrix metalloproteinase (MT1-MMP) is critical to a number of proteolytic and profibrotic events. However, upstream regulation of MT1-MMP with myocardial ischemia-reperfusion remains poorly understood. MicroRNAs regulate post-transcriptional events, and in silico mapping has identified a conserved sequence in MT1-MMP for microRNA-133a. This study tested the hypothesis that changes in microRNA-133a regulation occur with myocardial ischemia-reperfusion, which contributes to time- and region-dependent changes in MT1-MMP activity and processing of MT1-MMP substrates.Yorkshire pigs (n = 12) underwent ischemia-reperfusion (90 minutes ischemia and 120 minutes reperfusion), where regional preload recruitable stroke work (sonomicrometry), interstitial MT1-MMP activity (microdialysis), Smad2 abundance (immunoblotting), and interstitial microRNA-133a (polymerase chain reaction) were determined within the ischemia-reperfusion and remote regions. Human left ventricular fibroblasts were transduced with microRNA-133a and anti-microRNA-133a (lentivirus) to determine the effects on MT1-MMP protein abundance.With ischemia-reperfusion, regional preload recruitable stroke work decreased from steady state (139 ± 20 mm Hg to 44 ± 11 mm Hg, P < .05) within the ischemia-reperfusion region. MT1-MMP activity increased in both regions. Phosphorylated Smad2 increased within the ischemia-reperfusion region. Both in vitro and in vivo interstitial levels of microRNA-133a decreased with ischemia and returned to steady-state levels with reperfusion. In vitro transduction of microRNA-133a in left ventricular fibroblasts decreased MT1-MMP levels.Modulation of MT1-MMP activity and microRNA-133a exportation into the myocardial interstitium occurred in the setting of acute myocardial ischemia-reperfusion. In addition, changes in microRNA-133a expression in left ventricular fibroblasts resulted in an inverse modulation of MT1-MMP abundance. Therefore, targeting of microRNA-133a represents a potentially novel means for regulating the cascade of profibrotic events after ischemia-reperfusion.

Project description:Background and aimsThis study examined whether enhanced susceptibility of steatotic liver to ischemia-reperfusion (I/R) injury is due to impaired recruitment of bone marrow (BM) progenitors of liver sinusoidal endothelial cells (LSECs, also called sinusoidal endothelial cell progenitor cells [sprocs]) with diminished repair of injured LSECs and whether restoring signaling to recruit BM sprocs reduces I/R injury.Approach and resultsHepatic vessels were clamped for 1 hour in rats fed a high-fat, high-fructose (HFHF) diet for 5, 10, or 15 weeks. Matrix metalloproteinase 9 (MMP-9) antisense oligonucleotides (ASO) or an MMP inhibitor were used to induce liver-selective MMP-9 inhibition. HFHF rats had mild, moderate, and severe steatosis, respectively, at 5, 10, and 15 weeks. I/R injury was enhanced in HFHF rats; this was accompanied by complete absence of hepatic vascular endothelial growth factor (VEGF)-stromal cell-derived factor 1 (sdf1) signaling, leading to lack of BM sproc recruitment. Liver-selective MMP-9 inhibition to protect against proteolytic cleavage of hepatic VEGF using either MMP-9 ASO or intraportal MMP inhibitor in 5-week and 10-week HFHF rats enhanced hepatic VEGF-sdf1 signaling, increased BM sproc recruitment, and reduced alanine aminotransferase (ALT) by 92% and 77% at 5 weeks and by 80% and 64% at 10 weeks of the HFHF diet, respectively. After I/R injury in 15-week HFHF rats, the MMP inhibitor reduced active MMP-9 expression by 97%, ameliorated histologic evidence of injury, and reduced ALT by 58%, which is comparable to control rats sustaining I/R injury. Rescue therapy with intraportal MMP inhibitor, given after ischemia, in the 5-week HFHF rat reduced ALT by 71% and reduced necrosis.ConclusionsLack of signaling to recruit BM sprocs that repair injured LSECs renders steatotic liver more susceptible to I/R injury. Liver-selective MMP-9 inhibition enhances VEGF-sdf1 signaling and recruitment of BM sprocs, which markedly protects against I/R injury, even in severely steatotic rats.

Dataset Information

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

Publications

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

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets