Synthesis and release of activin and noggin by cultured human amniotic epithelial cells.
Recent studies suggest that extra-embryonic tissues may be essential sources of early organizing signals for the mouse embryo. In vitro studies of human amniotic epithelial cells (HAEC) have shown that the amnion can produce various biologically active substances. In this study, the synthesis and release of activin A and noggin, and the activin signaling pathway, was investigated in HAEC. Conditioned medium from cultured HAEC contained activin A which was functionally active in Xenopus laevis animal cap assays. Immunohistochemistry, western blotting and reverse transcription-polymerase chain reaction confirmed that HAEC also synthesize and release noggin. Noggin transcripts were induced by the addition of recombinant activin A, and activin A was inhibited by activin antibody except in the presence of cycloheximide (CHX). These data demonstrate that noggin mRNA expression is induced directly by activin A without new protein synthesis, indicating that noggin is a primary response gene. The results suggest that there is an activin signaling pathway in HAEC, and that the human amnion might therefore be involved in neural formation during early development.
Koyano
Satoru
S
Department of Inherited Metabolic Disease, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
Fukui
Akimasa
A
Uchida
Saiko
S
Yamada
Kazuto
K
Asashima
Makoto
M
Sakuragawa
Norio
N
D028341:Activins / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D000650:Amnion / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000494:pharmacology; D001681:Biological Assay; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D004847:Epithelial Cells / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D028322:Inhibin-beta Subunits / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014982:Xenopus laevis; D000099176:Noggin Protein
D028341:Activins; D000906:Antibodies; D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D017077:Culture Media, Conditioned; D028322:Inhibin-beta Subunits; D012333:RNA, Messenger; D000099176:Noggin Protein; C422405:activin A