BMP-2 and FGF-2 synergistically facilitate adoption of a cardiac phenotype in somatic bone marrow c-kit+/Sca-1+ stem cells.

Abstract

The aim of this study was to explore the effect of bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2)- paracrine factors implicated in both cardiac embryogenesis and cardiac repair following myocardial infarction (MI)-on murine bone marrow stem cell (mBMSC) differentiation in an ex vivo cardiac microenvironment. For this purpose, green fluorescent protein (GFP) expressing hematopoietic lineage negative (lin-) c-kit ligand (c-kit) and stem cell antigen-1 (Sca-1) positive (GFP-lin-/c-kit+/sca+) mBMSC were co-cultured with neonatal rat ventricular cardiomyocytes (NVCMs). GFP+ mBMSC significantly induced the expression of BMP-2 and FGF-2 in NVCMs, and approximately 4% GFP+ mBMSCs could be recovered from the co-culture at day 10. The addition of BMP-2 in concert with FGF-2 significantly enhanced the amount of integrated GFP+ mBMSCs by 5-fold ( approximately 20%), whereas the addition of anti-BMP-2 and/or anti-FGF-2 antibodies completely abolished this effect. An analysis of calcium cycling revealed robust calcium transients in GFP+ mBMSCs treated with BMP-2/FGF-2 compared to untreated co-cultures. BMP-2 and FGF-2 addition led to a significant induction of early (NK2 transcription factor related, locus 5; Nkx2.5, GATA binding protein 4; GATA-4) and late (myosin light chain kinase [MLC-2v], connexin 43 [Cx43]) cardiac marker mRNA expression in mBMSCs following co-culture. In addition, re-cultured fluorescence-activated cell sorting (FACS)-purified BMP-2/FGF-2-treated mBMSCs revealed robust calcium transients in response to electrical field stimulation which were inhibited by the L-type calcium channel (LTCC) inhibitor, nifedipine, and displayed caffeine-sensitive intracellular calcium stores. In summary, our results show that mBMSCs can adopt a functional cardiac phenotype through treatment with factors essential to embryonic cardiogenesis that are induced after cardiac ischemia. This study provides the first evidence that mBMSCs with long-term self-renewal potential possess the capability to serve as a functional cardiomyocyte precursor through the appropriate paracrine input and cross-talk within an appropriate cardiac microenvironment.

• Authors: Brent R Degeorge Jr, Marc Rosenberg, Volker Eckstein, Erhe Gao, Nicole Herzog, Hugo A Katus, Walter J Koch, Norbert Frey, Patrick Most
• Journal: Clinical and translational science (Clin Transl Sci) Vol. 1 Issue 2 Pg. 116-25 (Sep 2008) ISSN: 1752-8062 [Electronic] United States
• PMID: 20443832 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Ataxin-1
• Ataxins
• Atxn1 protein, mouse
• Atxn1 protein, rat
• Bone Morphogenetic Protein 2
• Nerve Tissue Proteins
• Nuclear Proteins
• Protein Isoforms
• RNA, Messenger
• Stem Cell Factor
• Transforming Growth Factor beta
• Fibroblast Growth Factor 2
• Green Fluorescent Proteins
• Calcium

Topics

• Animals
• Animals, Newborn
• Ataxin-1
• Ataxins
• Bone Marrow Cells (cytology)
• Bone Morphogenetic Protein 2 (genetics, metabolism, pharmacology)
• Calcium (metabolism)
• Coculture Techniques
• Fibroblast Growth Factor 2 (genetics, metabolism, pharmacology)
• Gene Expression Regulation (drug effects)
• Green Fluorescent Proteins (metabolism)
• Mice
• Myocardial Infarction (genetics, pathology)
• Myocardium (pathology)
• Myocytes, Cardiac (drug effects, metabolism)
• Nerve Tissue Proteins (metabolism)
• Nuclear Proteins (metabolism)
• Organogenesis (drug effects, genetics)
• Phenotype
• Protein Isoforms (genetics, metabolism)
• RNA, Messenger (genetics, metabolism)
• Rats
• Stem Cell Factor (metabolism)
• Stem Cells (cytology, drug effects, metabolism)
• Transforming Growth Factor beta (genetics, metabolism)