PA-FABP, a novel marker of human epidermal transit amplifying cells revealed by 2D protein gel electrophoresis and cDNA array hybridisation.
Human epidermal stem cells express higher levels of beta1 integrins than their more differentiated daughters, transit amplifying cells. In a search for additional stem and transit cell markers we used proteomics and differential cDNA hybridisation to compare keratinocytes fractionated on the basis of beta1 integrin expression. There were remarkably few differences between the two populations and none of the RNAs differed in abundance by more than 2-fold. Nevertheless, proteomics revealed upregulated expression of epidermal fatty acid binding protein (PA-FABP, also known as E-FABP), Annexin II and two keratin related proteins in the transit population. An unknown high molecular mass protein was upregulated in the stem cell population. The upregulation of PA-FABP was confirmed by Northern blotting and conventional and whole mount labelling of human epidermis. We conclude that PA-FABP is a novel marker of epidermal transit amplifying cells.
O'Shaughnessy
R F
RF
Keratinocyte Laboratory, Imperial Cancer Research Fund, London, UK.
Seery
J P
JP
Celis
J E
JE
Frischauf
A
A
Watt
F M
FM
D016475:3T3 Cells; D000818:Animals; D015415:Biomarkers; D015152:Blotting, Northern / Q000379:methods; D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics; D002478:Cells, Cultured; D018076:DNA, Complementary; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004817:Epidermis / Q000737:chemistry* / Q000473:pathology; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D019084:Fluorescent Antibody Technique, Indirect; D020869:Gene Expression Profiling; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D051379:Mice; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D011817:Rabbits; D025521:Tumor Suppressor Proteins
D015415:Biomarkers; D002352:Carrier Proteins; D018076:DNA, Complementary; C493412:FABP5 protein, human; C107608:FABP7 protein, human; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011506:Proteins; D025521:Tumor Suppressor Proteins