title: The histone methyltransferase inhibitor BIX01294 enhances the cardiac potential of bone marrow cells.
abstract: Bone marrow (BM) has long been considered a potential stem cell source for cardiac repair due to its abundance and accessibility. Although previous investigations have generated cardiomyocytes from BM, yields have been low, and far less than produced from ES or induced pluripotent stem cells (iPSCs). Since differentiation of pluripotent cells is difficult to control, we investigated whether BM cardiac competency could be enhanced without making cells pluripotent. From screens of various molecules that have been shown to assist iPSC production or maintain the ES cell phenotype, we identified the G9a histone methyltransferase inhibitor BIX01294 as a potential reprogramming agent for converting BM cells to a cardiac-competent phenotype. BM cells exposed to BIX01294 displayed significantly elevated expression of brachyury, Mesp1, and islet1, which are genes associated with embryonic cardiac progenitors. In contrast, BIX01294 treatment minimally affected ectodermal, endodermal, and pluripotency gene expression by BM cells. Expression of cardiac-associated genes Nkx2.5, GATA4, Hand1, Hand2, Tbx5, myocardin, and titin was enhanced 114, 76, 276, 46, 635, 123, and 5-fold in response to the cardiogenic stimulator Wnt11 when BM cells were pretreated with BIX01294. Immunofluorescent analysis demonstrated that BIX01294 exposure allowed for the subsequent display of various muscle proteins within the cells. The effect of BIX01294 on the BM cell phenotype and differentiation potential corresponded to an overall decrease in methylation of histone H3 at lysine9, which is the primary target of G9a histone methyltransferase. In summary, these data suggest that BIX01294 inhibition of chromatin methylation reprograms BM cells to a cardiac-competent progenitor phenotype.
authors.affiliation: New York Medical College/Westchester Medical Center Stem Cell Laboratory, Department of Physiology, New York Medical College, Valhalla, New York, USA.
authors.forename: Nadejda V
authors.initials: NV
authors.lastname: Mezentseva
authors.forename: Jinpu
authors.initials: J
authors.lastname: Yang
authors.forename: Keerat
authors.initials: K
authors.lastname: Kaur
authors.forename: Grazia
authors.initials: G
authors.lastname: Iaffaldano
authors.forename: Mathieu C
authors.initials: MC
authors.lastname: Rémond
authors.forename: Carol A
authors.initials: CA
authors.lastname: Eisenberg
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Eisenberg
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis; D001381:Azepines / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000201:enzymology; D005786:Gene Expression Regulation / Q000187:drug effects; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051379:Mice; D009124:Muscle Proteins / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000201:enzymology; D032383:Myocytes, Cardiac / Q000166:cytology / Q000201:enzymology; D011799:Quinazolines / Q000494:pharmacology*
chemical_list: D000943:Antigens, Differentiation; D001381:Azepines; C518299:BIX 01294; D009124:Muscle Proteins; D011799:Quinazolines; C533711:G9a protein, mouse; D011495:Histone-Lysine N-Methyltransferase