A new model for embryo implantation: coculture of blastocysts and Ishikawa cells

Abstract

Objective: To explore and develop a new in vitro implantation model that reflects the main process of embryo attachment and invasion. Study design: One of the limitations in human embryo implantation research is lack of an available in vitro model that faithfully replicates human embryo–uterine interactions. In the present study, we examined the attachment and invasiveness of blastocysts from mice in Ishikawa cell (IK), a human endometrial cell, to clarify whether this new model is suitable to study implantation of embryos. We used IK and placed it in contact with blastocysts to initiate coculture experiments using a specifically designed medium. The culture medium was composed of Ham F-12/Dulbecco’s modified Eagle medium (1:1), 30% fetal calf serum, 63.5 nmol/L progesterone, 7.14 nmol/L estradiol-17β, 100 mg/ml of insulin, and 20 ng/ml epidermal growth factor. The culture for 24 h clearly demonstrated that embryos were capable of attachment to the IK and displayed partial invasion. Results: Our results showed that embryos attached to the IK and displayed partial invasion after coculture of blastocysts with IK for 48 h. Conclusions: The model is capable of demonstrating the procedure of attachment and invasion of embryo into the endometrial cells and has promises to be used in studies related to early embryo implantation in human endometrium.

Keywords::

• Attachment
• blastocyst
• embryo
• implantation
• invasiveness
• model

Acknowledgement

The authors acknowledge Dr. Minyue Dong for his help in the paper writing.

Declaration of interest: The authors report no conflicts of interest. This work was supported by National Natural Science Foundation of China (NSFC No. 30901604), the technology applying research for public welfare of Zhejiang Province (No. 2010C33167), the Medical Scientific Research Program of Zhejiang Province (No. 2009B100), the Key Research Program of the Bureau of Family Planning and Reproduction of Zhejiang Province (No. 200887). Supported by the Key Scientific Research Project (No. 2012CB944900), and the Fundamental Research Funds for the Central Universities.