Affordable Access

deepdyve-link deepdyve-link
Publisher Website

Postnatal cardiomyocyte growth and mitochondrial reorganization cause multiple changes in the proteome of human cardiomyocytes.

Authors
Type
Published Article
Journal
Molecular BioSystems
1742-2051
Publisher
The Royal Society of Chemistry
Publication Date
Volume
9
Issue
6
Pages
1210–1219
Identifiers
DOI: 10.1039/c3mb25556e
PMID: 23459711
Source
Medline
License
Unknown

Abstract

Fetal (fCM) and adult cardiomyocytes (aCM) significantly differ from each other both by structure and biochemical properties. aCM own a higher mitochondrial mass compared to fCM due to increased energy demand and show a greater density and higher degree of structural organization of myofibrils. The energy metabolism in aCM relies virtually completely on β-oxidation of fatty acids while fCM use carbohydrates. Rewinding of the aCM phenotype (de-differentiation) arises frequently in diseased hearts spurring questions about its functional relevance and the extent of de-differentiation. Yet, surprisingly little is known about the changes in the human proteome occurring during maturation of fCM to aCM. Here, we examined differences between human fetal and adult hearts resulting in the quantification of 3500 proteins. Moreover, we analyzed mitochondrial proteomes from both stages to obtain more detailed insight into underlying biochemical differences. We found that the majority of changes between fCM and aCM were attributed to growth and maturation of cardiomyocytes. As expected, adult hearts showed higher mitochondrial mass and expressed increased levels of proteins involved in energy metabolism but relatively lower copy numbers of mitochondrial DNA (mtDNA) per total cell volume. We uncovered that the TFAM/mtDNA ratio was kept constant during postnatal development despite a significant increase of mitochondrial protein per mtDNA in adult mitochondria, which revises previous concepts.

Statistics

Seen <100 times