Open AccessBMP‐2 and FGF‐2 Synergistically Facilitate Adoption of a Cardiac Phenotype in Somatic Bone Marrow c‐kit+/Sca‐1+ Stem Cells
Author(s) -
DeGeorge, Jr. Brent R.,
Rosenberg Marc,
Eckstein Volker,
Gao Erhe,
Herzog Nicole,
Katus Hugo A.,
Koch Walter J.,
Frey Norbert,
Most Patrick
Publication year - 2008
Publication title -
clinical and translational science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.303
H-Index - 44
eISSN - 1752-8062
pISSN - 1752-8054
DOI - 10.1111/j.1752-8062.2008.00034.x
Subject(s) - paracrine signalling , green fluorescent protein , stem cell , microbiology and biotechnology , bone morphogenetic protein , bone marrow , biology , fibroblast growth factor , haematopoiesis , stem cell factor , bone morphogenetic protein 2 , immunology , in vitro , biochemistry , receptor , gene
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 (∼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.