Dynamic expression of E-cadherin in embryonic stem cell differentiation in vitro and correlation with cell adhesion

Anbin HU; Xiaoshun HE; Bing HUANG; Jiye CAI

ABSTRACT

BACKGROUND:

E-cadhedn plays an important role in development of liver tissue in the embryonic stage.Therefore,it is importance for investigating the feasibility of dynamic expression of E-cadherin in embryonic stern cell differentiation to in vitro development of liver tissue.

OBJECTIVE:

To observe the dynamic expression of E-cadherin in embryonic stem cell differentiation and the effect on cell adhesion.DESIGN,TIME AND

SETTING:

An in vitro cytological observation was performed at Surgical Laboratory of the First Affiliated Hospital of Sun Yat-sen University from December 2007 to December 2008.MATERIALSEmbryonic stem cells of BALB/c mice were obtained from Professor Huang (Department of Ophthalmology,Sun Yat-sen University).Twenty 13-day-old pregnant BALB/c mice of clean grade were provided by the Experimental Animal Centar of Sun Yat-sen University.

METHODS:

Following trypsinization,embryonic stem cells were suspend-incubated in DMEM culture medium containing fetal bovine serum,2-mercaptoethanol,HEPES,penicillin,and streptomycin.Embryoid body was formed 5 days after normal development and incubated in the culture plate at day 6.Liver tissue which was obtained from 13-day-old pregnant BALB/c mice was prepared for fetal liver cells which were frozen-sectioned as the controls.MAIN OUTCOME

MEASURES:

E-cadherin expression was detected using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry st varying time points of 1,5,9,13,and 17 days in stages of initial differentiation of embryonic stem cells,formation of embryoid body,and formation of differentiated clusters.Additionally,the effect of E-cadherin expression on cell adhesion was also detected.

RESULTS:

RT-PCR showed that E-cadherin mRNA expression was not observed at day 1 but peaked at day 5;gradually,the expression was decreased until the expression was stopped at day 17.E-cadherin mRNA expression was strong in fetal liver cells in the control group.Immunocytochemistry showed a similar outcome.Morphologically,embryonic stem cells developed from unicells into compact three-embryonic layer embryoid body and into incompact cell population.

CONCLUSION:

E-cadherin expression correlates with differentiated cell adhesion;additionally,the lost expression in an in vitro environment may be an important cause for unable regularization of differentiated cells.