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Down-Regulation of Replication Factor C-40 (RFC40) Causes Chromosomal Missegregation in Neonatal and Hypertrophic Adult Rat Cardiac Myocytes
- Source :
- PLoS ONE, PLoS ONE, Vol 7, Iss 6, p e39009 (2012)
- Publication Year :
- 2012
- Publisher :
- Public Library of Science, 2012.
-
Abstract
- BACKGROUND: Adult mammalian cardiac myocytes are generally assumed to be terminally differentiated; nonetheless, a small fraction of cardiac myocytes have been shown to replicate during ventricular remodeling. However, the expression of Replication Factor C (RFC; RFC140/40/38/37/36) and DNA polymerase δ (Pol δ) proteins, which are required for DNA synthesis and cell proliferation, in the adult normal and hypertrophied hearts has been rarely studied. METHODS: We performed qRT-PCR and Western blot analysis to determine the levels of RFC and Pol δ message and proteins in the adult normal cardiac myocytes and cardiac fibroblasts, as well as in adult normal and pulmonary arterial hypertension induced right ventricular hypertrophied hearts. Immunohistochemical analyses were performed to determine the localization of the re-expressed DNA replication and cell cycle proteins in adult normal (control) and hypertrophied right ventricle. We determined right ventricular cardiac myocyte polyploidy and chromosomal missegregation/aneuploidy using Fluorescent in situ hybridization (FISH) for rat chromosome 12. RESULTS: RFC40-mRNA and protein was undetectable, whereas Pol δ message was detectable in the cardiac myocytes isolated from control adult hearts. Although RFC40 and Pol δ message and protein significantly increased in hypertrophied hearts as compared to the control hearts; however, this increase was marginal as compared to the fetal hearts. Immunohistochemical analyses revealed that in addition to RFC40, proliferative and mitotic markers such as cyclin A, phospho-Aurora A/B/C kinase and phospho-histone 3 were also re-expressed/up-regulated simultaneously in the cardiac myocytes. Interestingly, FISH analyses demonstrated cardiac myocytes polyploidy and chromosomal missegregation/aneuploidy in these hearts. Knock-down of endogenous RFC40 caused chromosomal missegregation/aneuploidy and decrease in the rat neonatal cardiac myocyte numbers. CONCLUSION: Our novel findings suggest that transcription of RFC40 is suppressed in the normal adult cardiac myocytes and its insufficient re-expression may be responsible for causing chromosomal missegregation/aneuploidy and in cardiac myocytes during right ventricular hypertrophy.
- Subjects :
- Male
DNA polymerase
lcsh:Medicine
Gene Expression
Cardiovascular
Biochemistry
Rats, Sprague-Dawley
Molecular Cell Biology
Myocyte
Replication Protein C
lcsh:Science
Cells, Cultured
In Situ Hybridization, Fluorescence
Multidisciplinary
biology
Animal Models
Immunohistochemistry
Cell biology
Hypertension
Medicine
Biotechnology
Research Article
Down-Regulation
Cardiomegaly
Real-Time Polymerase Chain Reaction
Chromosomes
Molecular Genetics
Cytogenetics
Replication factor C
Model Organisms
Downregulation and upregulation
medicine
Genetics
Animals
Gene Regulation
Pulmonary Vascular Diseases
Ventricular remodeling
Protein Interactions
Molecular Biology
Biology
DNA Polymerase III
Heart Failure
DNA synthesis
Cell growth
Myocardium
lcsh:R
DNA replication
Proteins
medicine.disease
Molecular biology
Rats
Animals, Newborn
biology.protein
Rat
lcsh:Q
Protein Translation
Developmental Biology
Subjects
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 7
- Issue :
- 6
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.doi.dedup.....d652a20ce3eb9d35195046920eabb20c