Histochemistry and Cell Biology

, Volume 141, Issue 4, pp 423–430

Calpain 2 activity increases at the time of implantation in rat uterine luminal epithelial cells and administration of calpain inhibitor significantly reduces implantation sites

  • Yui Kaneko
  • Christopher R. Murphy
  • Margot L. Day
Original Paper

DOI: 10.1007/s00418-013-1165-y

Cite this article as:
Kaneko, Y., Murphy, C.R. & Day, M.L. Histochem Cell Biol (2014) 141: 423. doi:10.1007/s00418-013-1165-y

Abstract

The present study investigated the role of calpain 2 in rat uterine luminal epithelial cells during early pregnancy. Calpain 2 is an intracellular calcium-dependent proteolytic enzyme which cleaves numerous focal adhesion proteins. Calpain 2 was concentrated along the basal cell surface of uterine luminal epithelial cells at the predicted site of focal adhesions on day 1 of pregnancy and remained unchanged at the time of implantation as observed by immunofluorescence microscopy. However, Western blotting analysis showed a marked increase in the active form and a significant decrease in the latent form of calpain 2 at the time of implantation. The increase in calpain 2 activity coincides with the disassembly of focal adhesion proteins, talin, paxillin, integrin β1 and β3 from the site of focal adhesions. Intraperitoneal injection of calpain inhibitor, calpain inhibitor l (ALLN), significantly reduced the number of implantation sites, implying that calpain 2 plays an important role in implantation. The present study suggests a role for calpain 2 in the disassembly of focal adhesions, which has been previously shown to play a key role in uterine receptivity for implantation.

Keywords

Calpain 2ImplantationUterine luminal epithelial cells

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Yui Kaneko
    • 1
  • Christopher R. Murphy
    • 1
  • Margot L. Day
    • 2
  1. 1.School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch InstituteThe University of SydneySydneyAustralia
  2. 2.School of Medical Sciences (Discipline of Physiology) and The Bosch InstituteThe University of SydneySydneyAustralia