G9a histone methyltransferase inhibitor BIX01294 promotes expansion of adult cardiac progenitor cells without changing their phenotype or differentiation potential.
OBJECTIVE
As a follow-up to our previous reports showing that the G9a histone methyltransferase-specific inhibitor BIX01294 enhances bone marrow cell cardiac potential, this drug was examined for its effects on cardiomyocytes and mouse cardiac progenitor cells (CPCs).


METHODS
Cardiomyocytes and cardiac explants were cultured ± BIX01294, and examined for changes in cardiac function, protein and gene expression. Additionally, enriched populations of CPCs, contained in the 'phase bright cell' component of explants, were harvested from non-treated and BIX01294-treated cardiac tissue, and assayed for differences in cell phenotype and differentiation potential. Mouse CPCs were cultured with rat cardiomyocytes to allow differentiation of the progenitors to be assayed using species-specific PCR primers.


RESULTS
While BIX01294 had no discernible effect on myocyte function and sarcomeric organization, treatment with this drug significantly increased CPC proliferation, as indicated by enhanced MTT metabolization and BrdUrd incorporation (4.1- and 2.0-fold, respectively, P < 0.001) after 48 h labelling, and increased Ki67 expression (4.8-fold, P < 0.001) after 7 days culture. Heart explants exposed to BIX01294 generated 3.6-fold (P < 0.005) greater yields of CPCs by 2 weeks culture. Importantly, CPCs obtained from non-treated and BIX01294-treated cultures did not differ in phenotype or differentiation potential.


CONCLUSIONS
These data indicate that BIX01294 can expand CPCs without undermining their capacity as cardiac progenitors, and suggest that this drug may have utility for generating large numbers of CPCs for cardiac repair.
New York Medical College/Westchester Medical Center Stem Cell Laboratory, Departments of Physiology and Medicine, New York Medical College, Valhalla, New York, 10595, USA.
K
K
Kaur
New York Medical College/Westchester Medical Center Stem Cell Laboratory, Departments of Physiology and Medicine, New York Medical College, Valhalla, New York, 10595, USA.|Department of Biology and Genomics, New York University, New York, New York, 10003, USA.
J
J
Yang
Department of Physiology and Medicine, New York Medical College, Valhalla, New York, 10595, USA.
J G
JG
Edwards
New York Medical College/Westchester Medical Center Stem Cell Laboratory, Departments of Physiology and Medicine, New York Medical College, Valhalla, New York, 10595, USA.
C A
CA
Eisenberg
New York Medical College/Westchester Medical Center Stem Cell Laboratory, Departments of Physiology and Medicine, New York Medical College, Valhalla, New York, 10595, USA.
L M
LM
Eisenberg
D053687:Adult Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001381:Azepines / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D018920:Coculture Techniques; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology*; D017208:Rats, Wistar
D001381:Azepines; C518299:BIX 01294; D004791:Enzyme Inhibitors; D011799:Quinazolines; C577330:Ehmt2 protein, rat; C533711:G9a protein, mouse; D011495:Histone-Lysine N-Methyltransferase