Synthesis and secretion of apolipoprotein E by cultured human keratinocytes.
Non-polar lipids are synthesized by keratinocytes in the epidermis and transported to the extracellular space where they contribute to formation of a permeability barrier. Transport of non-polar lipids in other organs and tissues usually occurs with the lipid complexed to an apolipoprotein. In this study we set out to learn if apolipoprotein E is produced by human epidermal keratinocytes in culture. Analysis of total cellular RNA from cultured keratinocytes showed the presence of human apolipoprotein E mRNA at concentrations ranging from 2.5 to 35 molecules/cell. The cells secrete a protein identified as apo E on the basis of molecular weight, isoform pattern, and immunoreactivity. Enzyme linked immunosorbent assay of media from keratinocyte cultures indicated that apolipoprotein E is secreted at a rate of 0.92 ng/h/10(6) cells.
Gordon
D A
DA
Department of Oral Biology and Pathology, School of Dental Medicine, State University of New York, Stony Brook 11794-8702.
Fenjves
E S
ES
Williams
D L
DL
Taichman
L B
LB
D001057:Apolipoproteins E / Q000096:biosynthesis* / Q000378:metabolism; D002478:Cells, Cultured; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D006801:Humans; D007633:Keratins; D011233:Precipitin Tests; D012313:RNA / Q000032:analysis
D001057:Apolipoproteins E; D012313:RNA; D007633:Keratins