Adhesion to fibronectin induces megakaryocytic differentiation of JAS-REN cells.
BACKGROUND
Binding of integrins to the extracellular matrix elicits various responses. We have previously reported a megakaryocytic-erythroid cell line (JAS-R) that showed phenotypic changes after adhesion to plastic dishes. However, the matrix protein and the mechanism responsible for megakaryocytic differentiation still remain unknown.


METHODS
JAS-REN (erythroid) cells were cultured on dishes coated with various proteins. The cells were treated with RGDS, a tetrapeptide ligand to integrins, or phorbol ester (12-o-tetradecanoylphorbol-13-acetate, TPA) for 48 hours and then were harvested. Subsequently, the cell surface markers were analyzed using flow cytometry and gene expression was studied by RT-PCR.


RESULTS
The JAS-REN cells adhered to fibronectin-coated dishes, but showed poor adhesion to dishes coated with collagen, laminin or poly-D-lysine. The TPA-stimulated JAS-REN cells showed an increase in the expression of integrin alphaIIbbeta3 complex (CD41a) and integrin beta3 (CD61), while glycophorin A (CD235a) expression was decreased. JAS-REN cells that were adherent to fibronectin-coated dishes also showed a similar pattern of phenotype to TPA-treated cells, but the changes were not so prominent. RT-PCR revealed that TPA treatment altered the gene expression profile of JAS-REN cells, making it similar to that of JAS-RAD (megakaryocytic) cells. The RGDS-treated and fibronectin adherent JAS-REN cells also showed a mostly similar expression profile to JAS-RAD cells, but these two stimuli did not alter the gene expression profile as TPA stimulation did. Transcription factors, FLI1 and GFI1, were induced by all stimuli.


CONCLUSIONS
Signals triggered by adhesion to fibronectin result in the induction of FLI1 that may play a pivotal role in the lineage shift of JAS-REN cells from erythroid to megakaryocytic.
Yamada
Hisashi
H
Department of Molecular Genetics, Institute of DNA Medicine, Jikei University, School of Medicine, Tokyo 125-8506, Japan. hyamad@jikei.ac.jp
Sekikawa
Tetsuaki
T
Agawa
Miyuki
M
Iwase
Satsuki
S
Suzuki
Hideaki
H
Horiguchi-Yamada
Junko
J
D002448:Cell Adhesion; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D019070:Cell Lineage; D004912:Erythrocytes / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D005353:Fibronectins / Q000494:pharmacology; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D005353:Fibronectins; D009842:Oligopeptides; C046617:arginyl-glycyl-aspartyl-serine; D013755:Tetradecanoylphorbol Acetate