Abstract:

BACKGROUND: Previous studies have found that Schwann cells, olfactory ensheathing cells, neural stem cells and activated macrophages may repair nerve injuries, but these cells have some deficiencies, such as source restrictions, tumorigenicity, and allograft rejection. Amniotic epithelial cells have no above-mentioned limits, and possess multiple-differentiation potential. After the induction, amniotic epithelial cells may differentiate into cardiomyocyte-like cells, neural stem cells, liver cells, osteoblasts and chondrocytes.
OBJECTIVE: To culture rat amniotic epithelial cells which can be induced to differentiate into neural-like stem cells.
METHODS: Rat amniotic epithelial cells were collected from late pregnancy rats using digestion method. Serum-free medium of nerve stem cells was used to induce rat amniotic epithelial cells into neural-like stem cells. Normal and induced cells were identified by immunocytochemistry and reverse transcription-PCR methods.
RESULTS AND CONCLUSION: The morphological observation showed that amniotic epithelial cells cultured in the conditioned medium presented with cell body retraction and part of nuclei showed refractive enhancement; dendrite- and axon-like structures appeared, and these processes were woven into a mesh and adhered firmly. Immunocytochemistry results showed that the induced amniotic epithelial cells had a slightly stronger expression of Nestin and glial fibrillary acidic protein, while the pluripotent markers SSEA-4 and Vimentin expressions were weakened. Reverse transcription-PCR test showed that the induced amniotic epithelial cells had a higher mRNA expression of Nestin, glial fibrillary acidic protein and microtubule-associated protein, while the mRNA expression of mesodermal smooth muscle cell marker smooth muscle-22α and pluripotent markers Sox-2 and Nanog declined. These findings suggest that cultured rat amniotic epithelial cells can be induced to differentiate into neural-like stem cells.

Key words: stem cells, stem cell culture and differentiation, amniotic epithelial cells, induction, differentiation, neural-like stem cells, Nestin, glial fibrillary acidic protein, microtubule-associated protein, National “973&rdquo, Program of China, stem cell photographs-containing paper