Studies on the role of adhesive proteins in maintaining pregnancy.
It is well known that maternal fibrinogen (Fg) and factor X III are essential for maintaining early pregnancy. We studied their role by analysis of clinical reports and immunohistochemical investigation.


METHODS
(1) We analyzed the pregnancy cases of congenital afibrinogenemia and congenital factor X III deficiency. (2) Immunohistochemical staining of Fg, subunit A of factor X III (X IIIA) and fibronectin (Fn) were performed in the human implantation site, placenta, and endometrial cells cultured in serum-free medium.


RESULTS
(1) Afibrinogenemia needed to be administrated Fg from 4 weeks' gestation (4 wG), and factor X III deficiency needed factor X III concentrate from 5 wG, in order to prevent abortion. (2) Implantation tissues: Fg, cellular X IIIA and Fn were present at the decidual stroma around invasive cytotrophoblasts at 5 wG. X IIIA-positive cells coincided with LN-5-positive macrophages. Placenta: Fg, cellular X IIIA and Fn were present in the decidual layer. Endometrial culture cells: Fn was secreted by spindle-like shaped cells. X IIIA was secreted by round-shaped cells.


CONCLUSIONS
Maternal Fg and factor X III are essential just after 4-5 wG, and in that period they and Fn are present abundantly in decidual stroma around invasive cytotrophoblasts. It is concluded that when cytotrophoblasts invade endometrium maternal Fg, factor X III and Fn are concerned with cytotrophoblasts' anchoring as adhesive proteins.
Asahina
T
T
Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Japan. asahina@hama-med.ac.jp
Kobayashi
T
T
Okada
Y
Y
Itoh
M
M
Yamashita
M
M
Inamato
Y
Y
Terao
T
T
D000022:Abortion, Spontaneous / Q000517:prevention & control; D000328:Adult; D000347:Afibrinogenemia / Q000151:congenital / Q000628:therapy; D004717:Endometrium / Q000166:cytology / Q000378:metabolism; D005176:Factor XIII / Q000378:metabolism / Q000502:physiology* / Q000627:therapeutic use; D005177:Factor XIII Deficiency / Q000151:congenital / Q000628:therapy; D005260:Female; D005333:Fetus / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism / Q000502:physiology* / Q000627:therapeutic use; D006801:Humans; D007150:Immunohistochemistry; D010920:Placenta / Q000166:cytology / Q000378:metabolism; D011247:Pregnancy / Q000378:metabolism / Q000502:physiology*; D011261:Pregnancy Trimester, First / Q000502:physiology; D014018:Tissue Distribution
D005340:Fibrinogen; D005176:Factor XIII