title: Cardioprotection by a novel recombinant serine protease inhibitor in myocardial ischemia and reperfusion injury.
abstract: Polymorphonuclear neutrophils (PMN) play an important role in myocardial ischemia/reperfusion (MI/R) injury; however, the role of neutrophilic proteases is less understood. The effects of a novel serine protease inhibitor (serpin), LEX032, were investigated in a murine model of MI (20 min) and R (24 hr) injury in vivo. LEX032 is a recombinant human alpha 1-antichymotrypsin in which six amino acid residues were replaced around the active center with those of alpha-1 protease inhibitor. LEX032 has the ability to inhibit both neutrophil elastase and cathepsin G, two major neutral serine proteases in neutrophils, as well as superoxide generation. LEX032 (25 or 50 mg/kg) administered i.v. 1 min before reperfusion significantly attenuated myocardial necrotic injury evaluated by cardiac creatine kinase loss compared to MI/R rats receiving only vehicle (P < .001). Moreover, cardiac myeloperoxidase activity, an index of PMN accumulation, in the ischemic myocardium was significantly attenuated by LEX032 as compared with rats receiving vehicle (P < .001). LEX032 also moderately attenuated leukotriene B4-stimulated PMN adherence to rat superior mesenteric artery endothelium and markedly diminished superoxide radical release from LTB4-stimulated PMN in vitro. In a glycogen-induced rat peritonitis model, LEX032 (50 mg/kg) significantly attenuated PMN transmigration into the peritoneal cavity in vivo. In conclusion, the recombinant serine protease inhibitor, LEX032, appears to be an effective agent for attenuating MI/R injury by inhibiting neutrophil-accumulation into the ischemic-reperfused myocardium and by inactivating cytotoxic metabolites (proteases and superoxide radical) released from neutrophils.
authors.affiliation: Department of Physiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
authors.forename: T
authors.initials: T
authors.lastname: Murohara
authors.forename: J P
authors.initials: JP
authors.lastname: Guo
authors.forename: A M
authors.initials: AM
authors.lastname: Lefer
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002634:Chemotaxis, Leukocyte; D003402:Creatine Kinase / Q000378:metabolism; D004730:Endothelium, Vascular / Q000473:pathology; D006003:Glycogen / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D007975:Leukotriene B4 / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D017202:Myocardial Ischemia / Q000188:drug therapy* / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy* / Q000473:pathology; D009206:Myocardium / Q000201:enzymology; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism; D010529:Peritoneal Cavity / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000627:therapeutic use; D015842:Serine Proteinase Inhibitors / Q000627:therapeutic use*; D015843:Serpins / Q000627:therapeutic use*; D013481:Superoxides / Q000378:metabolism
chemical_list: D007375:Interleukin-1; C095800:LEX 032; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors; D015843:Serpins; D013481:Superoxides; D007975:Leukotriene B4; D006003:Glycogen; D003402:Creatine Kinase