Expression of liver fatty acid binding protein alters growth and differentiation of embryonic stem cells.
Although expression of liver fatty acid binding protein (L-FABP) modulates cell growth, it is not known if L-FABP also alters cell morphology and differentiation. Therefore, pluripotent embryonic stem cells were transfected with cDNA encoding L-FABP and a series of clones expressing increasing levels of L-FABP were isolated. Untransfected ES cells, as well as ES cells transfected only with empty vector, spontaneously differentiated from rounded adipocyte-like to fibroblast-like morphology, concomitant with marked reduction in expression of stage-specific embryonic antigen (SSEA-1). These changes in morphology and expression of SSEA-1 were greatest in ES cell clones expressing L-FABP above a threshold level. Immunofluorescence confocal microscopy revealed that L-FABP was primarily localized in a diffuse-cytosolic pattern along with a lesser degree of punctate L-FABP expression in the nucleus. Nuclear localization of L-FABP was preferentially increased in clones expressing higher levels of L-FABP. In summary, L-FABP expression altered ES cell morphology and expression of SSEA-1. Taken together with the fact that L-FABP was detected in the nucleus, these data suggested that L-FABP may play a more direct, heretofore unknown, role in regulating ES cell differentiation by acting in the nucleus as well as cytoplasm.
Schroeder
F
F
Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station 77843-4466, USA.
Atshaves
B P
BP
Starodub
O
O
Boedeker
A L
AL
Smith
R R
RR
Roths
J B
JB
Foxworth
W B
WB
Kier
A B
AB
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D002999:Clone Cells; D004622:Embryo, Mammalian / Q000166:cytology; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental; D006131:Growth Inhibitors / Q000494:pharmacology; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D016256:Lewis X Antigen / Q000502:physiology; D008099:Liver / Q000378:metabolism*; D008222:Lymphokines / Q000494:pharmacology; D051379:Mice; D018613:Microscopy, Confocal; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D014162:Transfection
D002352:Carrier Proteins; C493320:Fabp1 protein, mouse; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D006131:Growth Inhibitors; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D016256:Lewis X Antigen; C507838:Lif protein, mouse; D008222:Lymphokines; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins