Evidence of a novel isoform of placenta growth factor (PlGF-4) expressed in human trophoblast and endothelial cells.
Placenta growth factor (PlGF), a homodimeric glycoprotein that is homologous to vascular endothelial growth factor (VEGF), is mitogenic to endothelial cells and protects trophoblast from apoptosis. Alternative splicing of mature mRNA gives rise to three known isoforms of PlGF. PlGF is expressed by human trophoblast during normal pregnancy, however, it is not known which isoforms are produced. We have utilized RT-PCR to characterize PlGF isoform expression in normal human trophoblast and umbilical vein endothelial cells (HUVEC). Our results show that PlGF-1, PlGF-2, and PlGF-3 isoforms are expressed by trophoblast and HUVECs. In addition, both cell types also express a novel variant of PlGF, tentatively termed PlGF-4, which has not been previously reported. PlGF-4 consists of the same sequence of PlGF-3, plus the heparin binding domain previously thought to be present only in PlGF-2. Presence of the heparin binding domain in PlGF-4 suggests that this variant would remain cell membrane-associated and thus could influence trophoblast and endothelial cells in an autocrine manner.
Yang
Wen
W
Department of Obstetrics and Gynecology, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37920, USA.
Ahn
Henry
H
Hinrichs
Monica
M
Torry
Ronald J
RJ
Torry
Donald S
DS
D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000737:chemistry*; D005260:Female; D006801:Humans; D000072483:Placenta Growth Factor; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000096:biosynthesis* / Q000235:genetics; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014327:Trophoblasts / Q000737:chemistry*; D014471:Umbilical Veins / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
C000608036:PGF protein, human; D011257:Pregnancy Proteins; D020033:Protein Isoforms; D042461:Vascular Endothelial Growth Factor A; D000072483:Placenta Growth Factor