Development of human embryonic stem cell derivation.

Objective: To establish human embryonic stem (hES) cells from human embryos.

Design: Experimental study.

Setting: Reproductive Medicine Unit, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University.

Material And Method: Abnormal and normal fertilization embryos were cultured in vitro until reaching blastocyst stage. Four different methods for isolation of ICMs were used. Immunosurgery, mechanical isolation, laser assists, and whole blastocyst culture were performed. The feeder layers used in the present study were fibroblasts, isolated from either mouse or human. Mechanical splitting of ICM outgrowths or hES-like cells was performed for propagation of cells. Characterization of hES-like cells was conducted by morphology, detection of immunostaining of Oct-4, and enzymatic activity of alkaline phosphatase (AP). HES-like cells were spontaneously differentiated through suspension culture of embryoid body (EB). Subsequent differentiation was done on gelatin-coated dishes.

Main Outcome Measure: Establishment of hES cells.

Results: By using abnormal fertilization embryos, 80.0% (8/10) of blastocysts were able to attach on the feeder layers, 50% (4/8) formed ICM outgrowths, but no hES-like cells were established. By using normal fertilization embryos, 84.6% (22/26) of blastocysts were able to attach on feeder layers, 18.2% (4/22) formed ICM outgrowths. One hES-like cell line was successfully established by using mechanical isolation of ICMs and human adult skin fibroblasts as feeder layers. This hES-like cells exhibited typical morphology of hES cells, positive staining for Oct-4 and AP. hES-like cells were able to form EB and differentiated into neural-like cells.

Conclusion: This is the first report in Thailand that hES-like cells can be isolated from normal development human embryos at blastocysts-stage using mechanical isolation of ICM and culture with human adult skin fibroblast as feeder layers.