CD36 Is a Matrix Metalloproteinase-9 Substrate That Stimulates Neutrophil Apoptosis and Removal During Cardiac Remodeling. (February 2016)

• Record Type: Journal Article
• Authors: DeLeon-Pennell, Kristine Y.; Tian, Yuan; Zhang, Bai; Cates, Courtney A.; Iyer, Rugmani Padmanabhan; Cannon, Presley; Shah, Punit; Aiyetan, Paul; Halade, Ganesh V.; Ma, Yonggang; Flynn, Elizabeth; Zhang, Zhen; Jin, Yu-Fang; Zhang, Hui; Lindsey, Merry L.
• Is Part Of: Circulation. Volume 9:Number 1(2016)
• Publication Date: 2016-02
• Subjects: extracellular matrix -- immunoblotting -- infarction -- inflammation -- myocardial -- proteomics; Arrhythmia -- Periodicals; Heart -- Electric properties -- Periodicals; 616.1042
• DOI: 10.1161/CIRCGENETICS.115.001249
• Languages: English
• ISSNs: 1942-325X

Abstract

Abstract : Background—: After myocardial infarction, the left ventricle undergoes a wound healing response that includes the robust infiltration of neutrophils and macrophages to facilitate removal of dead myocytes as well as turnover of the extracellular matrix. Matrix metalloproteinase (MMP)-9 is a key enzyme that regulates post-myocardial infarction left ventricular remodeling. Methods and Results—: Infarct regions from wild-type and MMP-9 null mice (n=8 per group) analyzed by glycoproteomics showed that of 541 N -glycosylated proteins quantified, 45 proteins were at least 2-fold upregulated or downregulated with MMP-9 deletion (all P <0.05). Cartilage intermediate layer protein and platelet glycoprotein 4 (CD36) were identified as having the highest fold increase in MMP-9 null mice. By immunoblotting, CD36 but not cartilage intermediate layer protein decreased steadily during the time course post-myocardial infarction, which identified CD36 as a candidate MMP-9 substrate. MMP-9 was confirmed in vitro and in vivo to proteolytically degrade CD36. In vitro stimulation of day 7 post-myocardial infarction macrophages with MMP-9 or a CD36-blocking peptide reduced phagocytic capacity. Dual immunofluorescence revealed concomitant accumulation of apoptotic neutrophils in the MMP-9 null group compared with wild-type group. In vitro stimulation of isolated neutrophils with MMP-9 decreased neutrophil apoptosis, indicated by reduced caspase-9 expression. Conclusions—: Our data reveal a new cell-signaling role for MMP-9 through CD36 degradation to regulate macrophage phagocytosis and neutrophil apoptosis. Abstract : Supplemental Digital Content is available in the text.