gms | German Medical Science

Multipotent precursors, able to generate neurons, astrocytes and oligodendrocytes have been isolated from human brain embryos in the past and from neurogenic regions of the adult brains more recently. The isolation of multipotent neural precursors from adult human brains has opened new perspectives in the study of adult neurogenesis and brain repair potentials. The present study describes the in vitro isolation, proliferation and differentiation of a neural progenitor population from the adult human brain.

Tissue isolated from surgical samples taken during stereotactic surgeries or partial temporal lobotomy from epilepsy patients, was enzymatically digested and propagated into substrate-free culture flasks. Cells were proliferated as neurospheres in growth medium supplemented with mitogens. Differentiation of expanded cells was acquired by plating dissociated spheres, onto polyornithine coated cover-slips in mitogen-free medium. After 14 days, the cultures were fixed and processed for immunocytochemistry against βIII-tubulin, microtubule associated protein 2 (MAP-2), glial fibrillary acid protein (GFAP), neuroepethilial precurcor cell marker–nestin. The proliferative activity of the cultures was investigated with BrdU incorporation assay – 62 hours incubation of the respective cultures with medium containing 10 nM of BrdU, followed by 14 days of differentiation.

48 samples were used for this study. Samples obtained during stereotactic biopsies (n=12) were very small and showed no proliferation capacities. The average age of the patients participating in this part of the study was 55.5 years. On the other hand, samples that were obtained during epilepsy surgeries (n= 36) came from younger patients (average 25.5 years old) and included cells that could proliferate (up to 5 months) and differentiate in vitro. Immunostaining of these cultures revealed bIII-tubulin, MAP-2, GFAP, nestin and BrdU positive cells.

The present study suggests that adult human neural progenitor cells can be isolated and expanded in vitro, without losing their potential to differentiate into cells with neuronal or glia features. Therefore, these cells might serve as a useful source of human neurons for neuroregenerative strategies in neurological diseases as well as a human cell model to investigate the regenerative potential of endogenous neural stem cells.