Neuronal differentiation of stem cells derived from human umbilical cord matrix.

摘要

Stem cells have shown promising therapeutic potential and provide an ideal model for studying development and disease. However, the controversy surrounding the use of human embryonic stem (ES) cells has led to the search for a new highly versatile source of stem cells. Recently stem cells were isolated from the human umbilical cord matrix (HUCM). These cells express markers of stem cells and appear to be highly plastic. Further the cells are derived from the human umbilical cord, which is discarded after birth and is therefore regarded as a non-controversial source of stem cells. HUCM cell lines were isolated from human umbilical cords obtained via cesarean section, grown in culture and induced to differentiate into a neuronal cell type via treatment with bFGF and antioxidants. Following differentiation HUCM cells exhibited electrical excitability which was not present in non-induced cells. Protein biochemistry studies show HUCM cells express myofibroblast proteins and following neuronal induction the cells express neuronal proteins. Further protein analysis of induced and non-induced HUCM cell samples was achieved using 2D electrophoresis. Various combinations of running conditions, buffers and sample preparation methods were first compared in order to find the ideal conditions for separation of HUCM cell lysates. Subsequent analysis of HUCM cell lysates separated via 2D gel electrophoresis showed significant changes in protein expression following neuronal induction of HUCM cells.{09}A functional proteomics approach was then employed to elucidate key proteins involved in the differentiation of HUCM cells into neurons. Induced and non-induced samples were compared to induced cells treated with potassium and signaling cascade blockers in an effort to identify proteins involved in neural differentiation. All samples were subjected to 2D gel electrophoresis.{09}Gels were then analyzed and the results of blockade studies indicated more than 20 proteins whose expression is altered when treated with blockers. The results of these studies show that analysis of HUCM cells using proteomics is a powerful method by which proteins that are key in human disease and development can be identified. Furthermore, the studies show that HUCM cells are an easily obtainable, highly versatile alternative source of stem cells.