title: α-Enolase plays a catalytically independent role in doxorubicin-induced cardiomyocyte apoptosis and mitochondrial dysfunction.
abstract: BACKGROUND
  α-Enolase is a glycolytic enzyme with "second jobs" beyond its catalytic activity. However, its possible contribution to cardiac dysfunction remains to be determined. The present study aimed to investigate the role of α-enolase in doxorubicin (Dox)-induced cardiomyopathy as well as the underlying mechanisms.
  
  
  METHODS
  The expression of α-enolase was detected in rat hearts and primary cultured rat cardiomyocytes with or without Dox administration. An adenovirus carrying short-hairpin interfering RNA targeting α-enolase was constructed and transduced specifically into the heart by intramyocardial injection. Heart function, cell apoptosis and mitochondrial function were measured following Dox administration. In addition, by using gain- and loss-of-function approaches to regulate α-enolase expression in primary cultured rat cardiomyocytes, we investigated the role of endogenous, wide type and catalytically inactive mutant α-enolase in cardiomyocyte apoptosis and ATP generation. Furthermore, the involvement of α-enolase in AMPK phosphorylation was also studied.
  
  
  RESULTS
  The mRNA and protein expression of cardiac α-enolase was significantly upregulated by Dox. Genetic silencing of α-enolase in rat hearts and cultured cardiomyocytes attenuated Dox-induced apoptosis and mitochondrial dysfunction. In contrast, overexpression of wide-type or catalytically inactive α-enolase in cardiomyocytes mimicked the detrimental role of Dox in inducing apoptosis and ATP reduction. AMPK dephosphorylation was further demonstrated to be involved in the proapoptotic and ATP-depriving effects of α-enolase.
  
  
  CONCLUSIONS
  Our findings provided the evidence that α-enolase has a catalytically independent role in inducing cardiomyocyte apoptosis and mitochondrial dysfunction, which could be at least partially contributed to the inhibition of AMPK phosphorylation.
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China; School of Medicine, Guangxi University of Science and Technology, No. 257 Liu-shi Road, Liuzhou 545005, Guangxi, PR China.
authors.forename: Si
authors.initials: S
authors.lastname: Gao
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Xiao-jun
authors.initials: XJ
authors.lastname: Feng
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Zhi-ping
authors.initials: ZP
authors.lastname: Liu
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China; Guangzhou Research Institute of Snake Venom, Guangzhou Medical College, Guangzhou 510182, Guangdong, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lu
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Xiao-yang
authors.initials: XY
authors.lastname: Huang
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Jiao-jiao
authors.initials: JJ
authors.lastname: Wang
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China.
authors.forename: Shao-rui
authors.initials: SR
authors.lastname: Chen
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China. Electronic address: yejt@mail.sysu.edu.cn.
authors.forename: Jian-tao
authors.initials: JT
authors.lastname: Ye
authors.affiliation: Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Higher Education Mega Center, No. 132 East Wai-huan Road, Guangzhou 510006, Guangdong, PR China. Electronic address: liupq@mail.sysu.edu.cn.
authors.forename: Pei-qing
authors.initials: PQ
authors.lastname: Liu
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000256:Adenoviridae / Q000378:metabolism; D000263:Adenylate Kinase / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D055162:Biocatalysis / Q000187:drug effects; D019069:Cell Respiration / Q000187:drug effects; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000201:enzymology*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D004317:Doxorubicin; D000255:Adenosine Triphosphate; D000263:Adenylate Kinase; D010751:Phosphopyruvate Hydratase
keywords: AMPK; Apoptosis; Cardiomyocyte; Doxorubicin; Mitochondria; α-Enolase