Endothelial cells of the human microvasculature express epidermal fatty acid-binding protein.
Epidermal fatty acid-binding protein (E-FABP), previously characterized in human keratinocytes, is a cytoplasmic protein of 15 kD that specifically binds fatty acids (FAs). Previous PAGE-immunoblotting studies indicated that several human tissues display an immunoreactive band with an electrophoretic mobility identical to that of E-FABP. The aim of this study was to determine in which cells, other than keratinocytes, E-FABP might be expressed. By immunohistochemistry, we show that E-FABP is expressed in endothelial cells of the microvasculature of the placenta, heart, skeletal muscle, small intestine, lung, and renal medulla. Interestingly, in lung, a tissue of endodermal origin, E-FABP staining was also localized to secretory cells, ie, Clara cells, goblet cells, and probably a subpopulation of pneumocytes. RNA isolated from cultured human umbilical vein and normal human dermal microvascular endothelial cells was analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR). Southern blotting and sequencing of the cloned RT-PCR products demonstrate that endothelial E-FABP is identical to keratinocyte E-FABP. These data suggest that E-FABP-mediated FA transport occurs at the level of the microvasculature in several FA target organs.
Masouyé
I
I
Department of Dermatology, University Hospital, Geneva, Switzerland.
Hagens
G
G
Van Kuppevelt
T H
TH
Madsen
P
P
Saurat
J H
JH
Veerkamp
J H
JH
Pepper
M S
MS
Siegenthaler
G
G
D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008833:Microcirculation / Q000166:cytology / Q000378:metabolism; D018996:Myelin P2 Protein / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D014018:Tissue Distribution; D025521:Tumor Suppressor Proteins
D002352:Carrier Proteins; D017931:DNA Primers; C493412:FABP5 protein, human; C107608:FABP7 protein, human; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D018996:Myelin P2 Protein; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins