THE GROWTH PROPERTY OF NEURAL STEM CELLS ISOLATED FROM DIFFERENT PARTS OF MICE CNS——AN IN VITRO STUDY / 解剖学报

ABSTRACT

Objective To compare the growth property of the stem cells taken from different brain regions at the same developmental stage. Methods Mice embryos at the same development stage were isolated under sterile conditions, cortex, striatum, diencephalon, mid-hind brain and spinal cord were collected and pooled separately, after single-cell suspension obtained, different regions' cell suspensions were seeded in FGF supplemented serum-free culture medium. Followed the neural stem cell clone(neurospheres) fromation, immuno-cytochemistry method was utilized to identify the cell characteristics, all these clones were passaged under same conditions, clone formation and cell migration were observed under phase-contrast microscope. Results In the FGF added serum-free medium, neural cells experienced a large scale death within 48h after being seeded, then few single cells began to proliferate and formed the floating cell clones in the medium. These clones (neurospheres) could form new clones when seeded as single cell suspension. If these clones were seeded on poly-orithine, they could differentiate into neurons and glia cells. Compare the clone formation and cell migration, we found that cortex, striatum, diencephalon all could form floating clones with different rate, the cortex formed clones at the highest rate, striatum and diencephalon at lower rate; few neurospheres formed from cortex adhered to the culture plate substrate and few cells were found migrating out from the adhered clones, striatum and diencephalon derived neurospheres adhered the plate more easily, and there were apparent cell migration. Mid-hind brain and spinal cord formed clones at the lowest rate, floating clones were scarce, and the clones adhered to the substrate readily, there were large amount of cell migrating out from these adhered clones. Conclusion Neural stem cells could proliferate and be passaged in vitro in serum-free medium, and they could be induced to differentiate under certain conditions into major cells types of CNS, there were differences in clone forming rate and cell migration between neural stem cells derived from different CNC regions, nonetheless they were at the same development stage, this may reflect that, in some degree, these cells can keep some of their region-specified developmental intrinsic property in vitro.