The Role of Bcl-2 and Retinoic Acid during Embryonic Stem Cell Differentiation in Vitro

• Main Authors: Wei Lu Chen, 魏履貞
• Other Authors: 王建平
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/60816598499845317832

碩士 === 國立成功大學 === 生物學系 === 87 === There are 80 to 90 percent of neurons will die during nervous system development of vertebrates because of apoptosis. The proto - oncogene product Bcl-2 is unique in that it inhibits apoptosis rather than promoting cell proliferation. In the other hand, retinoic acid (RA) is one of the principle active metabolites of Vitamin A (retinol), and is believed to be essential for development, cell differentiation and physiological homeostasis. In the present study, we use mouse embryonic stem cells (ES cells) as a model to analyze the role of Bcl-2 and RA in neuronal differentiation during ES cells differentiation via Embryoid Body (EBs) formation or RA induction in vitro. According to our immunohistochemistry results, we found that the expression of neuron-specific genes encoding NFL, NFM, and NFH were corresponding to the in vivo condition no matter through EB formation or RA induction. But incubation of ES cells with 10-7M RA can facilitate the neuronal differentiation about 5 days earlier than EB formation induced differentiation. In the other hand, during the ES cells differentiation, the Bcl-2 protein is specific expressed in neuronal-like and fibroblast-like differentiated cells, and the expression amount of NFL, NFM, and NFH is larger after Bcl-2 expression. In addition, ES cells can differentiate into five different kinds of cells via EB formation: fibroblast-like; neuronal-like; epithelial-like; and two different kinds of self-contracting cells. Previous studies indicated that in vitro ES cells can differentiate into two self-contracting cells: skeletal muscle cells and cardiomyocytes. But the morphology of the two self-contracting cells we found is not identical to them. What kind of cells they are still to be clarified. Taken together, our results demonstrate that RA induction is an efficient method to stimulate ES cells differentiate into neurons and the Bcl-2 protein seems to facilitate the neuronal differentiation. Besides neurons, there are several other cell types also differentiated from ES cells indicating that this model system might be useful for studying early developmental process in vitro.