A role for alphavbeta3 integrin during implantation in the rabbit model

Area of Science:

• Reproductive Biology
• Developmental Biology
• Cellular Adhesion

Background:

• Uterine receptivity is key for successful implantation.
• Alpha(v)beta(3) integrin is a biomarker for uterine receptivity in various species.
• The distribution of alpha(v)beta(3) integrin in the rabbit implantation model was previously unknown.

Purpose of the Study:

• To investigate the expression and distribution of alpha(v)beta(3) integrin subunit in the rabbit uterus during implantation.
• To determine the functional role of alpha(v)beta(3) integrin in early embryo-maternal interactions in rabbits.

Main Methods:

• Reverse transcription-polymerase chain reaction (RT-PCR) to analyze mRNA expression.
• Immunohistochemistry and immunofluorescence to localize protein expression.
• In situ hybridization to detect mRNA localization.
• Functional blocking studies using anti-alpha(v)beta(3) antibody and RGD peptides.

Main Results:

• Alpha(v)beta(3) integrin was strongly expressed on the Day 6.5 rabbit blastocyst.
• Beta(3) subunit mRNA levels were higher at implantation sites compared to non-implantation sites.
• Immunohistochemistry showed minimal beta(3) immunoreactivity on the endometrial epithelium, while in situ hybridization revealed beta(3) mRNA in the myometrium and trophoblast.
• Blocking alpha(v)beta(3) integrin with LM609 antibody or RGD peptides significantly reduced the number of implantation sites.

Conclusions:

• The alpha(v)beta(3) integrin is expressed on the rabbit embryo and trophoblast.
• This integrin plays a significant role in early embryo-maternal interactions during implantation in the rabbit.
• The rabbit model is suitable for studying the functional significance of alpha(v)beta(3) integrin in implantation.