Bone marrow stromal cells contract synchronously with cardiomyocytes in a coculture system.
OBJECTIVE
Cell transplantation is a promising therapy for improving damaged heart function. Cardiac environmental factors are thought to be powerful differentiation inducers, but their effects are not well understood because of their in vivo nature. We simulated the cardiac environment using coculture and evaluated cardiomyogenic differentiation in bone marrow stromal cells and synchronous contraction with other cardiomyocytes.


METHODS
Experiment 1. We evaluated the labeling efficiency, intensity, and pattern of green fluorescence in the transgenic mouse expressing green fluorescent protein-derived bone marrow stromal cells (GFP-BMCs) from initial plating through 8 weeks under fluorescent microscopy. Experiment 2. GFP-BMCs (10(5) cells) were cocultured with neonatal rat cardiomyocytes (10(5) cells). We also evaluated the incorporation, myogenic differentiation, and synchronous contraction of GFP-BMCs for 1 week under the same microscopy with a digital video camera.


RESULTS
Experiment 1. All GFP-BMCs but red blood cells maintained green fluorescence from initial plating through 8 weeks. Experiment 2. Some GFP-BMCs were incorporated in parallel with cardiomyocytes and showed myotube-like formation on day 1. On day 2, GFP-BMCs started to contract synchronously with cardiomyocytes. GFP-BMCs formed colonies and maintained synchronous contraction on day 7.


CONCLUSIONS
Direct cell-to-cell interaction with cardiomyocytes is essential for myogenic differentiation and synchronous contraction of bone marrow cells. This coculture is a simple tool for simulating the cardiac environment and evaluating phenotypic changes in vitro.
Tomita
Shinji
S
Department of Regenerative Medicine, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Nakatani
Takeshi
T
Fukuhara
Shinya
S
Morisaki
Takayuki
T
Yutani
Chikao
C
Kitamura
Soichiro
S
D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D051379:Mice; D008822:Mice, Transgenic; D009206:Myocardium / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley