title: CREG protects from myocardial ischemia/reperfusion injury by regulating myocardial autophagy and apoptosis.
abstract: Human cellular repressor of E1A-stimulated genes (CREG) is a secreted glycoprotein that regulates tissue and cell homeostasis and has been shown to antagonize heart fibrosis, which indicates a potential protective effect of CREG against cardiomyocyte chronic damage. However, little is known about the role of CREG in myocardial tissue acute injury, in this study, we aimed to investigate the role of CREG in myocardial ischemia/reperfusion (MI/R) injury and clarify the mechanism of action.
  
  
  
  Wild-type Creg (Creg+/+), heterozygous Creg (Creg+/-) mice and mice pretreated with infusion of recombinant 0.3mg/kg·d CREG protein (reCreg+/+) were subjected to 30min of left ascending coronary ischemia and 24h of reperfusion. Evan's Blue-triphenyl- tetrazolium chloride (TTC) solution and echocardiography analysis were used to evaluate the effects of CREG on MI/R mice. The underlying mechanisms were further determined by cultured myocardial cells in vitro. Our findings revealed that the level of CREG protein in mouse hearts was significantly decreased after mice were subjected to MI/R. Moreover, Creg+/-mice had larger infarction size 2h after reperfusion and worse cardiac function 28days after MI/R injury compared to that in Creg+/+mice. However, reCreg+/+mice could maintain CREG at a high level even after MI/R injury, and mitigated infarction size and improved cardiac function significantly. In Creg+/-mice, myocardial autophagy was dysfunctional characterized by accumulation of LC3A and p62, while apoptotic cell number increase was detected by cleaved caspase-3 blotting and TUNEL staining. Conversely, decreased apoptosis and activated autophagy were detected in reCreg+/+mice. Furthermore, chloroquine, a kind of autophagy blocker, was used to demonstrate recombinant CREG protected cardiomyocytes against apoptosis mediated by activating autophagy both in vivo and in vitro. Finally, we found CREG was involved into lysosomal protein transfer and improve cellular autophagy.
  
  
  
  CREG protects heart against MI/R injury-induced cardiomyocytes apoptosis by activating lysosomal autophagy. This article is part of a Special Issue entitled: Genetic and epigenetic control of heart failure - edited by Jun Ren and Megan Yingmei Zhang.
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China; Xijing Hospital, Fourth Military Medical University, Xi'an, Shanxi, China.
authors.forename: Haixu
authors.initials: H
authors.lastname: Song
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Chenghui
authors.initials: C
authors.lastname: Yan
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Tian
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhu
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Meili
authors.initials: M
authors.lastname: Liu
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Chengfei
authors.initials: C
authors.lastname: Peng
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China.
authors.forename: Quanyu
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA, USA.
authors.forename: Erhe
authors.initials: E
authors.lastname: Gao
authors.affiliation: Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China. Electronic address: yaling.han1953@gmail.com.
authors.forename: Yaling
authors.initials: Y
authors.lastname: Han
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D002738:Chloroquine / Q000494:pharmacology*; D004195:Disease Models, Animal; D008247:Lysosomes / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D015428:Myocardial Reperfusion Injury / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C485248:Creg protein, mouse; D009124:Muscle Proteins; D012097:Repressor Proteins; D002738:Chloroquine
keywords: Apoptosis; Autophagy; CREG; Cardiac function; Ischemia/reperfusion injury; Lysosome