title: Overexpression of mitochondrial transcription factor a ameliorates mitochondrial deficiencies and cardiac failure after myocardial infarction.
abstract: BACKGROUND
  Mitochondrial DNA (mtDNA) copy number is decreased not only in mtDNA-mutation diseases but also in a wide variety of acquired degenerative and ischemic diseases. Mitochondrial transcription factor A (TFAM) is essential for mtDNA transcription and replication. Myocardial mtDNA copy number and TFAM expression both decreased in cardiac failure. However, the functional significance of TFAM has not been established in this disease state.
  
  
  RESULTS
  We have now addressed this question by creating transgenic (Tg) mice that overexpress human TFAM gene and examined whether TFAM could protect the heart from mtDNA deficiencies and attenuate left ventricular (LV) remodeling and failure after myocardial infarction (MI) created by ligating the left coronary artery. TFAM overexpression could ameliorate the decrease in mtDNA copy number and mitochondrial complex enzyme activities in post-MI hearts. Survival rate during 4 weeks of MI was significantly higher in Tg-MI than in wild-type (WT) littermates (WT-MI), although infarct size was comparable. LV cavity dilatation and dysfunction were significantly attenuated in Tg-MI. LV end-diastolic pressure was increased in WT-MI, and it was also reduced in Tg-MI. Improvement of LV function in Tg-MI was accompanied by a decrease in myocyte hypertrophy, apoptosis, and interstitial fibrosis as well as oxidative stress in the noninfarcted LV.
  
  
  CONCLUSIONS
  Overexpression of TFAM inhibited LV remodeling after MI. TFAM may provide a novel therapeutic strategy of cardiac failure.
authors.affiliation: Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ikeuchi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Matsusaka
authors.forename: Dongchon
authors.initials: D
authors.lastname: Kang
authors.forename: Shouji
authors.initials: S
authors.lastname: Matsushima
authors.forename: Tomomi
authors.initials: T
authors.lastname: Ide
authors.forename: Toru
authors.initials: T
authors.lastname: Kubota
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Naotaka
authors.initials: N
authors.lastname: Hamasaki
authors.forename: Akira
authors.initials: A
authors.lastname: Takeshita
authors.forename: Kenji
authors.initials: K
authors.lastname: Sunagawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsutsui
mesh_terms: D000818:Animals; D003433:Crosses, Genetic; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D006333:Heart Failure / Q000503:physiopathology / Q000517:prevention & control*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008929:Mitochondria, Heart / Q000201:enzymology / Q000235:genetics; D028361:Mitochondrial Diseases / Q000503:physiopathology / Q000517:prevention & control*; D024101:Mitochondrial Proteins / Q000235:genetics*; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; D014157:Transcription Factors; C422562:mitochondrial transcription factor A