Hum. Reprod. Advance Access originally published online on July 24, 2009
Human Reproduction 2009 24(11):2879-2889; doi:10.1093/humrep/dep250
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Interactions between galectin-3 and integrinβ3 in regulating endometrial cell proliferation and adhesion
1 Department of Reproductive Endocrinology, Obstetrics & Gynecology Hospital, Fudan University, 413 Zhaozhou Road, Shanghai 200011, China 2 Liver Cancer Institute, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
3 Correspondence address. Tel: +86-21-63455050; Fax: +86-21-63457331; E-mail: zhang.wei.fudan{at}gmail.com
BACKGROUND: Galectin-3 (gal-3) is a β-galactoside-binding protein which can be detected in endometrium. The study was designed to investigate synergism of gal-3 and integrinβ3 in endometrial cell proliferation and adhesion in an in vitro model of endometrial receptivity.
METHODS: The RL95-2 cell line was employed as an in vitro model for receptive endometrium. Cells transfected with gal-3 siRNA or treated with exogenous gal-3 were incubated with or without function-blocking integrinβ1/3 antibody for evaluating synergism of gal-3 and integrins on cell proliferation and adhesion. Proliferation was measured by BrdU incorporation, and adhesion to fibronectin (FN) was determined by an adhesion assay. Integrin expression was analyzed by Flow Cytometry and western blots. Bewo spheroids were co-cultured with the RL95-2 monolayer to mimic the blastocyst–endometrial interaction, and colocalization of gal-3, integrinβ3 and FN at the interface was observed by confocal microscopy.
RESULTS: The knock-down of gal-3 inhibited RL95-2 cell proliferation and adhesion. However, a reduction of proliferation and adhesion was also observed in presence of exogenous gal-3, and this was further reduced by a functional block to integrinβ3. Moreover, gal-3 knock-down significantly increased integrinβ3 expression, however, the colocalization of integrinβ3 and FN was not increased. As expected, the colocalization of integrinβ3 was decreased with the knock-down of gal-3.
CONCLUSIONS: This study has provided an in vitro model for the complex interactions between gal-3 and integrinβ3 in the regulation of endometrial cell proliferation and adhesion.
Key words: galectin-3/integrin/endometrial receptivity/proliferation/adhesion
Submitted on December 5, 2008; resubmitted on June 1, 2009; accepted on June 19, 2009.