Molecular Human Reproduction, Vol. 6, No. 8, 735-742,
August 2000
© 2000 European Society of Human Reproduction and Embryology
Uterine physiology |
Human myometrial cells in culture express specific binding sites for urinary trypsin inhibitor
Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Handacho 3600, Hamamatsu, Shizuoka, 431-3192, Japan
Abstract
Urinary trypsin inhibitor (UTI), which is present in amniotic fluid, prevents uterine contractility during pregnancy possibly via specific binding protein mechanisms. To test for the presence of UTI binding sites on the cell surface, we prepared cultured myometrial cells obtained at biopsy from 12 pregnant women and performed binding, competition, and cross-linking experiments using a specific radiolabelled UTI as a ligand. We report for the first time two classes of binding sites of differing affinities. Scatchard analysis at 4°C, using radioiodinated UTI, revealed that UTI binds to 35 000 high affinity binding sites/cell (Kd = 9.1x10–9 mol/l) and 450 000 lower affinity binding sites/cell (Kd = 3.5x10–7 mol/l) in cultured myometrial cells. It appears to be the low affinity site that is internalized, and this has been identified as a protein of ~45 kDa by cross-linking and immunoaffinity labelling studies. Monoclonal antibodies against the NH2-terminal fragment of UTI abrogated specific binding of this protein to the cells. Treatment of the cells with hyaluronidase resulted in >80% inhibition of the [125I]-labelled UTI binding to the cells. These data show that the UTI binding site, which is hyaluronidase sensitive, is expressed on the surface of human uterine myometrial cells to accumulate the UTI molecule during pregnancy.
myometrium/parturition/urinary trypsin inhibitor/UTI/UTI-binding protein
Notes
1 To whom correspondence should be addressed at: Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Handacho 3600, Hamamatsu, Shizuoka, 431-3192, Japan. E-mail: hirame{at}hama-med.ac.jp
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  K. Inagaki, H. Kobayashi, R. Yoshida, Y. Kanada, Y. Fukuda, T. Yagyu, T. Kondo, N. Kurita, T. Kitanaka, Y. Yamada, et al. Suppression of Urokinase Expression and Invasion by a Soybean Kunitz Trypsin Inhibitor Are Mediated through Inhibition of Src-dependent Signaling Pathways J. Biol. Chem., September 9, 2005; 280(36): 31428 - 31437. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. S. Soloff, Y.-J. Jeng, M. Ilies, S. L. Soloff, M. G. Izban, T. G. Wood, N. I. Panova, G. V.N. Velagaleti, and G. D. Anderson Immortalization and characterization of human myometrial cells from term-pregnant patients using a telomerase expression vector Mol. Hum. Reprod., September 1, 2004; 10(9): 685 - 695. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Schlabritz-Loutsevitch, N. Hellner, R. Middendorf, D. Muller, and J. Olcese The Human Myometrium as a Target for Melatonin J. Clin. Endocrinol. Metab., February 1, 2003; 88(2): 908 - 913. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Suzuki, H. Kobayashi, M. Fujie, T. Nishida, M. Takigawa, N. Kanayama, and T. Terao Kunitz-type Protease Inhibitor Bikunin Disrupts Phorbol Ester-induced Oligomerization of CD44 Variant Isoforms Containing Epitope v9 and Subsequently Suppresses Expression of Urokinase-type Plasminogen Activator in Human Chondrosarcoma Cells J. Biol. Chem., March 1, 2002; 277(10): 8022 - 8032. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Hirashima, H. Kobayashi, M. Suzuki, Y. Tanaka, N. Kanayama, M. Fujie, T. Nishida, M. Takigawa, and T. Terao Characterization of Binding Properties of Urinary Trypsin Inhibitor to Cell-associated Binding Sites on Human Chondrosarcoma Cell Line HCS-2/8 J. Biol. Chem., April 20, 2001; 276(17): 13650 - 13656. [Abstract] [Full Text] [PDF]
|
|