title: Galectin-1 is part of human trophoblast invasion machinery--a functional study in vitro.
abstract: BACKGROUND
  Interactions of glycoconjugates with endogenous galectins, have been long proposed to participate in several reproductive processes including implantation. In human placenta gal-1, gal-3, gal-8, and gal-13 proteins are known to be present. Each of them has been proposed to play multiple functions, but so far no clear picture has emerged. We hypothesized that gal-1 participates in trophoblast invasion, and conducted Matrigel invasion assay using isolated cytotrophoblast from first trimester placenta and HTR-8/SVneo cell line to test it.
  
  
  RESULTS
  Function blocking anti-gal-1 antibody was employed to assess participation of endogenous gal-1 in cell adhesion, cell invasion of HTR-8/SVneo cells. When gal-1 was blocked in isolated trophoblast cell invasion was reduced to 75% of control (SEM ± 6.3, P<0.001) and to 66% of control (SEM ± 1.7, P<0.001) in HTR-8/SVneo cell line. Increased availability of gal-1, as two molecular forms of recombinant human gal-1 (CS-gal-1 and Ox-gal-1), resulted in increased cell invasion by cytotrophoblast to 151% (SEM ± 16, P<0.01) with 1 ng/ml of CS-gal-1, and to 192% (SEM ± 51, P<0.05) with 1 µg/ml of Ox-gal-1. Stimulation was also observed in HTR-8/SVneo cells, to 317% (SEM ± 58, P<0.001) by CS-gal-1, and to 200% (SEM ± 24, P<0.001) by Ox-gal-1 at 1 µg/ml. Both sets of results confirmed involvement of gal-1 in trophoblast invasion. Galectin profile of isolated cytotrophoblast and HTR-8/SVneo cells was established using RT-PCR and real-time PCR and found to consist of gal-1, gal-3 and gal-8 for both cell types. Only gal-1 was located at the trophoblast cell membrane, as determined by FACS analysis, which is consistent with the results of the functional tests.
  
  
  CONCLUSIONS
  These findings qualify gal-1 as a member of human trophoblast cell invasion machinery.
authors.affiliation: Laboratory for Biology of Reproduction, Institute INEP, University of Belgrade, Belgrade, Serbia.
authors.forename: Nikola
authors.initials: N
authors.lastname: Kolundžić
authors.forename: Žanka
authors.initials: Ž
authors.lastname: Bojić-Trbojević
authors.forename: Tamara
authors.initials: T
authors.lastname: Kovačević
authors.forename: Ivana
authors.initials: I
authors.lastname: Stefanoska
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kadoya
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Vićovac
mesh_terms: D019138:Antibodies, Blocking / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D002469:Cell Separation; D002470:Cell Survival / Q000187:drug effects; D005434:Flow Cytometry; D037483:Galectin 1 / Q000276:immunology / Q000378:metabolism*; D037502:Galectin 3 / Q000378:metabolism; D037161:Galectins / Q000378:metabolism; D006801:Humans; D007785:Lactose / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins / Q000378:metabolism; D014327:Trophoblasts / Q000166:cytology* / Q000378:metabolism*
chemical_list: D019138:Antibodies, Blocking; D037483:Galectin 1; D037502:Galectin 3; D037161:Galectins; C091991:LGALS8 protein, human; D011994:Recombinant Proteins; D007785:Lactose