title: Inhibition of ischemic cardiomyocyte apoptosis through targeted ablation of Bnip3 restrains postinfarction remodeling in mice.
abstract: Following myocardial infarction, nonischemic myocyte death results in infarct expansion, myocardial loss, and ventricular dysfunction. Here, we demonstrate that a specific proapoptotic gene, Bnip3, minimizes ventricular remodeling in the mouse, despite having no effect on early or late infarct size. We evaluated the effects of ablating Bnip3 on cardiomyocyte death, infarct size, and ventricular remodeling after surgical ischemia/reperfusion (IR) injury in mice. Immediately following IR, no significant differences were observed between Bnip3(-/-) and WT mice. However, at 2 days after IR, apoptosis was diminished in Bnip3(-/-) periinfarct and remote myocardium, and at 3 weeks after IR, Bnip3(-/-) mice exhibited preserved LV systolic performance, diminished LV dilation, and decreased ventricular sphericalization. These results suggest myocardial salvage by inhibition of apoptosis. Forced cardiac expression of Bnip3 increased cardiomyocyte apoptosis in unstressed mice, causing progressive LV dilation and diminished systolic function. Conditional Bnip3 overexpression prior to coronary ligation increased apoptosis and infarct size. These studies identify postischemic apoptosis by myocardial Bnip3 as a major determinant of ventricular remodeling in the infarcted heart, suggesting that Bnip3 may be an attractive therapeutic target.
authors.affiliation: Center for Molecular Cardiovascular Research and Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA.
authors.forename: Abhinav
authors.initials: A
authors.lastname: Diwan
authors.forename: Maike
authors.initials: M
authors.lastname: Krenz
authors.forename: Faisal M
authors.initials: FM
authors.lastname: Syed
authors.forename: Janaka
authors.initials: J
authors.lastname: Wansapura
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Ren
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Koesters
authors.forename: Hairong
authors.initials: H
authors.lastname: Li
authors.forename: Lorrie A
authors.initials: LA
authors.lastname: Kirshenbaum
authors.forename: Harvey S
authors.initials: HS
authors.lastname: Hahn
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Robbins
authors.forename: W Keith
authors.initials: WK
authors.lastname: Jones
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Dorn
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008817:Mice, Mutant Strains; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D009203:Myocardial Infarction / Q000473:pathology*; D015428:Myocardial Reperfusion Injury / Q000235:genetics* / Q000473:pathology*; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology*; D020257:Ventricular Remodeling / Q000235:genetics*
chemical_list: C508686:BNip3 protein, mouse; D008565:Membrane Proteins; D024101:Mitochondrial Proteins