Effects of EGF and bFGF on expression of microtubule-associated protein tau and MAP-2 mRNA of mononuclear cells derived from human umbilical cord blood / 中国病理生理杂志

ABSTRACT

AIM: To explore the regulatory effects of cytokines such as EGF, bFGF on expression of neural-specific molecules in mononuclear cells (MNCs) cultured in H-DMEM medium. METHODS: The umbilical cord blood samples were collected from health puerperal natural delivery. The mononuclear cells were isolated by centrifugation over Lymphoprep and planted in T-75 flasks containing H-DMEM medium with or without addition of EGF, bFGF or EGF plus bFGF at a final concentration of 20 ?g/L, respectively. Phenotypic changes were monitored by inverse phase-contrast microscopy. Tau and MAP2 mRNA were determined by reverse-transcript polymerase chain reaction (RT-PCR). Tau and MAP2-positive cell were determined by immunocytochemistry. RESULTS: The expression of tau protein mRNA was negative in uncultured cells, but MAP2 mRNA was positive. In cultured cells, tau protein mRNA expressed positively, MAP2 mRNA expression was upregulated by EGF+bFGF, EGF or bFGF compared with control group (no cytokines). The upregulatory capability of EGF+bFGF to MAP2 mRNA expression was stronger than that of EGF or bFGF alone. The same upregulatory tendency was noted in tau mRNA expression. In the group of control, bFGF, EGF, EGF+bFGF, the rate of MAP2-positive cells was 14.4%, 19.6%, 25.6%, 33.5%, respectively. Tau protein-positive cells were 13.5%, 15.3%, 21.4%, 29.8%, respectively. Under inverse microscopy, the freshly isolated MNCs were small and round, after culturing, the cells became larger with some big, long cytodenrites in the EGF+bFGF group, with 1 or 2 threadlike cytodenrites in the EGF group, or with some short multi-dendron like-astrocyte in the bFGF group and control group, but the number of astrocyte-like cells in the control group was less than that in bFGF group. CONCLUSION: MNCs derived from human umbilical cord blood cells express some neural specific molecules and are upregulated by cytokines, especially EGF and bFGF, which have the synergetic action. [