COEXISTANCE OF THE S100BETA+ CELL POPULATIONS OF THE OLIGODENDROCYTE AND ASTROCYTE IMMUNOPHENOTYPES IN THE DEVELOPING HUMAN NEOCORTEX

S100beta is widely used as an astroglial marker with soma/endfeet location and glioblastoma prognostic marker. It is also referred to express in developing oligodendrocytes.
Brain hemisphaerias from sixteen human fetuses at the stages from 11 gestational weeks (GW) to birth were used in the study. Double-labeling fluorescence with the anti-S100beta, -OLIG2, -SOX10 and -SOX9, -ALDH1L1, -GFAP revealed coexistence of the S100beta+ cells coexpressing oligodendroglial transcriptional factors with S100beta+ cells, which demonstrate colocalization with astroglial markers at the all stages from early to late fetal periods, also as in the white and gray matter of a newborn.
Dorsal gliogenic wave in a human fetal telencephalon turns on at the end of early fetal period possessing astroglial marker manifestation, including the S100beta, in the ventricular/subventricular zones after 17GW. In contrast to other markers of a mature astroglial cell (GFAP, ALDH1L1), which first appearing and further expansion align with the dorsal gliogenic wave, S100b+ cells present in a developing human cortex earlier – from the pre-fetal stage. S100beta+ cell distribution in the telencephalon of early fetuses is close to the OLIG2/SOX10- and differ from the SOX9-marker pattern. The majority of S100beta+ cells possess colocalization with OLIG2/SOX10 at the pre-fetal period. Early S100beta+ cells of oligodendrocyte immunophenotype seem to be of ventral (ganglionic eminence) origin. S100b+ cells double-labelled with OLIG2/SOX10 demonstrate differ stage-depend pattering and quantitative ratios in comparison with S100beta+/SOX9+ cells at all stages. Our results evidence for the S100b+ cell population diversity in the developing human neocortex with the oligodendroglial immunophenotype predominance.