title: Expression of CD44 adhesion molecules on human placentae.
abstract: OBJECTIVE
  This study was performed to characterize CD44 expression in human placentae.
  
  
  METHODS
  We conducted reverse transcriptase polymerase chain reaction (RT-PCR) analyses of CD44H (hematopoietic form, also called CD44s) and CD44R1 (epithelial form) in 14 normal term placentae, and immunohistochemical analysis of CD44H and CD44v6 in 31 placentae (25 term and 6 first-trimester).
  
  
  RESULTS
  All 14 term placentae expressed CD44H (double bands) suggesting expression of alternative isoforms on the placentae. CD44R1 was expressed on 3 of 14 (21.4%) term placentae. Immunohistochemical analysis revealed expression of CD44H in all the placentae examined. However, positive staining for CD44v6 was observed in 3 of 6 (50%) first-trimester and only 6 of 25 (24%) term placentae showing decreased expression on term placentae. Positive staining for CD44v6 was observed on the trophoblast surface of immature villi especially in the sub-chorionic area where hypoxic conditions prevail.
  
  
  CONCLUSIONS
  These results suggest that CD44 splicing variants might play a role in the invasion of trophoblast into maternal tissue in early pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Chel Hun
authors.initials: CH
authors.lastname: Choi
authors.forename: Cheong Rae
authors.initials: CR
authors.lastname: Roh
authors.forename: Tae-Joong
authors.initials: TJ
authors.lastname: Kim
authors.forename: Yoon-La
authors.initials: YL
authors.lastname: Choi
authors.forename: Jeong-Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Byoung-Gie
authors.initials: BG
authors.lastname: Kim
authors.forename: Je-Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Duk-Soo
authors.initials: DS
authors.lastname: Bae
mesh_terms: D017398:Alternative Splicing; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D018960:Hyaluronan Receptors