Expression of lymphatic vascular endothelial hyaluronan receptor-1 (LYVE-1) in the human placenta.
BACKGROUND
Lymphatic vascular endothelial hyaluronan receptor-1 (LYVE-1) is a selective marker for lymphatic endothelium and a homolog of CD44, the hyaluronan (HA) receptor. HA in the extracellular matrix plays roles in tissue remodeling, development, and homeostasis, and as an HA receptor, LYVE-1 mediated HA metabolism might regulate these events. Currently, little is known about the lymphatic character within the human placenta. This study therefore determined LYVE-1 and other lymphatic markers in human placentas.


RESULTS
Placentas and villous tissue were fixed and immunostained for human LYVE-1 and CD44 and examined by RT-PCR. LYVE-1 was expressed at both protein and mRNA levels in trophoblast cells (TC) and in villous core endothelium (VCE). Predominant protein expression for LYVE-1 was observed in syncytiotrophoblast cells (TCs) of preterm placentas. Neither mRNA or protein for CD44 was expressed. Other blood and lymphatic-lineage molecules (VEGF-A, -C, and -D, Flt-1, KDR, Flt-4, and Prox-1) were examined by RT-PCR. VEGF-A, VEGF-D, and Flt-1 mRNA were observed in TCs and VCEs, while mRNA for VEGF-C, KDR, and Flt-4 was mainly observed in VCEs. Prox-1 was found at the mRNA, but not protein level in TCs and VCEs. Our findings indicate (1) the importance of LYVE-1, but not CD44, in regulation of HA metabolism in the maternal-fetal interface and fetal circulation, and (2) possible dual blood and lymphatic phenotypic characteristics in fetal endothelium. These results provide new insights into HA metabolism and lymphatic-lineage molecule expression in the human placenta.
Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, 71130, USA.
Baihan
B
Gu
J Steven
JS
Alexander
Yang
Y
Gu
Yanping
Y
Zhang
David F
DF
Lewis
Yuping
Y
Wang
D004730:Endothelium, Vascular / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D042601:Lymphatic Vessels / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000096:biosynthesis* / Q000235:genetics*
C119248:LYVE1 protein, human; D012333:RNA, Messenger; D033921:Vesicular Transport Proteins