title: Calpain inhibitors exhibit matrix metalloproteinase-2 inhibitory activity.
abstract: Matrix metalloproteinase (MMP)-2 is a zinc-dependent endopeptidase which, alongside its known extracellular actions, plays fundamental roles in oxidative stress-induced injury to the heart. Intracellular cleavage targets of MMP-2 selectively mediating this injury include the sarcomeric proteins troponin I, myosin light chain-1 and titin; some of these are also targeted by calpains. In myocardial ischemia and reperfusion injury, inhibitors of MMP-2 and some calpain inhibitors were shown to improve the recovery of contractile function. We hypothesized that the protective effects of calpain inhibitors may be due in part to their ability to inhibit MMP-2. Four calpain inhibitors (calpain inhibitor III, ALLM, ALLN, and PD-150606) were tested for their ability to inhibit MMP-2 in comparison to the selective MMP inhibitor ONO-4817. At 100 μM, all calpain inhibitors, except ALLM, showed significant inhibition of MMP-2 gelatinolytic activity. When assessed by the troponin I proteolysis assay, both ALLN and PD-150606, but neither ALLM nor calpain inhibitor III (at 20 μM), significantly inhibited MMP-2 activity. Using a fluorogenic MMP substrate peptide OmniMMP in a kinetic assay the rank order of IC(50) values against MMP-2 were: PD-150606<ALLN<calpain inhibitor III <<< ALLM. These experiments show that the calpain inhibitors PD-150606 and ALLN have significant additional pharmacological activity as MMP-2 inhibitors. This suggests that the protective effect of some calpain inhibitors is due in part to their ability to inhibit MMP activity.
authors.affiliation: Department of Pharmacology, University of Alberta, Edmonton, AB, Canada T6G 2S2.
authors.forename: Mohammad A M
authors.initials: MA
authors.lastname: Ali
authors.forename: Alesandra
authors.initials: A
authors.lastname: Stepanko
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Fan
authors.forename: Andrew
authors.initials: A
authors.lastname: Holt
authors.forename: Richard
authors.initials: R
authors.lastname: Schulz
mesh_terms: D000179:Acrylates / Q000494:pharmacology; D002154:Calpain / Q000037:antagonists & inhibitors*; D002384:Catalysis / Q000187:drug effects; D002460:Cell Line; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004151:Dipeptides / Q000494:pharmacology; D005780:Gelatin / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D007976:Leupeptins / Q000494:pharmacology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D009842:Oligopeptides / Q000494:pharmacology; D010647:Phenyl Ethers / Q000494:pharmacology; D019210:Troponin I / Q000378:metabolism
chemical_list: D000179:Acrylates; D015853:Cysteine Proteinase Inhibitors; D004151:Dipeptides; D007976:Leupeptins; D061965:Matrix Metalloproteinase Inhibitors; C414368:N-hydroxy-5-ethoxymethyloxy-2-methyl-4-(4-phenoxybenzoyl)aminopentanamide; D009842:Oligopeptides; C100442:PD 150606; D010647:Phenyl Ethers; D019210:Troponin I; C063261:acetylleucyl-leucyl-norleucinal; C069861:calpain inhibitor 2; D005780:Gelatin; D002154:Calpain; D020778:Matrix Metalloproteinase 2; C058076:calpain inhibitor III