MicroRNA-17-mediated down-regulation of apoptotic protease activating factor 1 attenuates apoptosome formation and subsequent apoptosis of cardiomyocytes.
Heart diseases such as myocardial infarction (MI) can damage individual cardiomyocytes, leading to the activation of cell death programs. The most scrutinized type of cell death in the heart is apoptosis, and one of the key events during the propagation of apoptotic signaling is the formation of apoptosomes, which relay apoptotic signals by activating caspase-9. As one of the major components of apoptosomes, apoptotic protease activating factor 1 (Apaf-1) facilitates the formation of apoptosomes containing cytochrome c (Cyto-c) and deoxyadenosine triphosphate (dATP). Thus, it may be possible to suppress the activation of the apoptotic program by down-regulating the expression of Apaf-1 using miRNAs. To validate this hypothesis, we selected a number of candidate miRNAs that were expected to target Apaf-1 based on miRNA target prediction databases. Among these candidate miRNAs, we empirically identified miR-17 as a novel Apaf-1-targeting miRNA. The delivery of exogenous miR-17 suppressed Apaf-1 expression and consequently attenuated formation of the apoptosome complex containing caspase-9, as demonstrated by co-immunoprecipitation and immunocytochemistry. Furthermore, miR-17 suppressed the cleavage of procaspase-9 and the subsequent activation of caspase-3, which is downstream of activated caspase-9. Cell viability tests also indicated that miR-17 pretreatment significantly prevented the norepinephrine-induced apoptosis of cardiomyocytes, suggesting that down-regulation of apoptosome formation may be an effective strategy to prevent cellular apoptosis. These results demonstrate the potential of miR-17 as an effective anti-apoptotic agent.
Department of Cardiovascular & Thoracic Surgery, College of Medicine, Catholic Kwandong University, Gangneung, Gangwon-do 210-701, Republic of Korea; Department of Medicine, The Graduate School, Yonsei University, Seoul 120-752, Republic of Korea.
Seungjun
S
Song
Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 120-752, Republic of Korea.
Hyang-Hee
HH
Seo
Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 120-752, Republic of Korea.
Se-Yeon
SY
Lee
Department of Integrated Omics for Biomedical Sciences, Yonsei University, Seoul 120-752, Republic of Korea.
Chang Yeon
CY
Lee
Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 120-752, Republic of Korea.
Jiyun
J
Lee
Division of Cardiovascular Surgery, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea.
Kyung-Jong
KJ
Yoo
Department of Cardiovascular & Thoracic Surgery, College of Medicine, Catholic Kwandong University, Gangneung, Gangwon-do 210-701, Republic of Korea.
Cheesoon
C
Yoon
Catholic Kwandong University International St. Mary's Hospital, Incheon Metropolitan City 404-834, Republic of Korea; Institute for Bio-Medical Convergence, College of Medicine, Catholic Kwandong University, Gangneung-si, Gangwon-do 210-701, Republic of Korea.
Eunhyun
E
Choi
Catholic Kwandong University International St. Mary's Hospital, Incheon Metropolitan City 404-834, Republic of Korea; Institute for Bio-Medical Convergence, College of Medicine, Catholic Kwandong University, Gangneung-si, Gangwon-do 210-701, Republic of Korea. Electronic address: kchwang@cku.ac.kr.
Ki-Chul
KC
Hwang
Catholic Kwandong University International St. Mary's Hospital, Incheon Metropolitan City 404-834, Republic of Korea; Institute for Bio-Medical Convergence, College of Medicine, Catholic Kwandong University, Gangneung-si, Gangwon-do 210-701, Republic of Korea. Electronic address: sam1017@ish.or.kr.
Seahyoung
S
Lee
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D053478:Apoptosomes / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D053477:Apoptotic Protease-Activating Factor 1 / Q000235:genetics / Q000378:metabolism*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism; D003838:Deoxyadenine Nucleotides / Q000378:metabolism; D005786:Gene Expression Regulation; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D061251:Primary Cell Culture; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D014162:Transfection
C506594:Apaf1 protein, rat; D053478:Apoptosomes; D053477:Apoptotic Protease-Activating Factor 1; D003838:Deoxyadenine Nucleotides; C000601368:MIRN17 microRNA, rat; D035683:MicroRNAs; D045304:Cytochromes c; D053148:Caspase 3; D053453:Caspase 9; D009638:Norepinephrine
Apaf-1; Apoptosome; Cardiomyocytes; miR-17