title: Oxidative stress during mitochondrial biogenesis compromises mtDNA integrity in growing hearts and induces a global DNA repair response.
abstract: Cardiomyocyte development in mammals is characterized by a transition from hyperplastic to hypertrophic growth soon after birth. The rise of cardiomyocyte cell mass in postnatal life goes along with a proportionally bigger increase in the mitochondrial mass in response to growing energy requirements. Relatively little is known about the molecular processes regulating mitochondrial biogenesis and mitochondrial DNA (mtDNA) maintenance during developmental cardiac hypertrophy. Genome-wide transcriptional profiling revealed the activation of transcriptional regulatory circuits controlling mitochondrial biogenesis in growing rat hearts. In particular, we detected a specific upregulation of factors involved in mtDNA expression and translation. More surprisingly, we found a specific upregulation of DNA repair proteins directly linked to increased oxidative damage during heart mitochondrial biogenesis, but only relatively minor changes in the mtDNA replication machinery. Our study paves the way for improved understanding of mitochondrial biogenesis, mtDNA maintenance and physiological adaptation processes in the heart and provides the first evidence for the recruitment of nucleotide excision repair proteins to mtDNA in cardiomyocytes upon DNA damage.
authors.affiliation: Department of Cardiac Development and Remodelling, Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany. Jaakko.Pohjoismaeki@mpi-bn.mpg.de
authors.forename: Jaakko L O
authors.initials: JL
authors.lastname: Pohjoismäki
authors.forename: Thomas
authors.initials: T
authors.lastname: Boettger
authors.forename: Zhipei
authors.initials: Z
authors.lastname: Liu
authors.forename: Steffi
authors.initials: S
authors.lastname: Goffart
authors.forename: Marten
authors.initials: M
authors.lastname: Szibor
authors.forename: Thomas
authors.initials: T
authors.lastname: Braun
mesh_terms: D000375:Aging / Q000235:genetics; D000818:Animals; D049108:Cell Enlargement; D004249:DNA Damage; D004260:DNA Repair; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000378:metabolism*; D005786:Gene Expression Regulation; D006321:Heart / Q000196:embryology / Q000254:growth & development*; D008929:Mitochondria, Heart / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D015854:Up-Regulation
chemical_list: D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins