GABAergic neuronal differentiation induced by brain-derived neurotrophic factor in human mesenchymal stem cells

Abstract

Mesenchymal stem cells (MSCs) have been derived from different sources including adipose tissue (AT), bone marrow (BM), and umbilical cord blood (UCB). We investigated that human MSCs may differentiate into neurons that produce γ-aminobutyric acid ((GABA)ergic neurons) in response to brain-derived neurotrophic factor (BDNF). This potential for GABAergic neuronal differentiation was also evaluated in MSCs derived from different sources of AT, BM, and UCB. For this purpose, the AT-, BM-, and UCB-MSCs were plated onto poly-D-lysine/laminin with BDNF, and were compared with control MSCs cultured without BDNF. To compare various neuronal differentiation potential among BM-, UCB-, and AT-MSCs, reverse transcription polymerase chain reaction was performed with nestin, a neural stem cell marker, ChAT, a cholinergic neuronal marker, TH, a dopaminergic neuronal marker, and GAD67, a GABAergic neuronal marker. Immunocytochemistry was also assessed as the expression of βIII-tubulin and GABA. As a result, the BDNF-treated groups of BM-, UCB-, and AT-MSCs expressed nestin at higher levels than control MSCs. In addition, the BDNF-treated groups of BM- and UCB-MSCs expressed GAD67 at higher levels than control MSCs, whereas GAD67 was not increased in the BDNF-treated group of AT-MSCs. In immunocytochemistry, exposure to BDNF promoted GABAergic neuronal differentiation, as demonstrated by the increased percentages of GABA+/GABA+ /4′,6-diamidino-2-phenylindole (DAPI)+ cells compared with the control cultures of AT-, BM-, and UCB-MSCs. In particular, after the BDNF-induced GABAergic neuronal differentiation, GABA+/DAPI+ cells (%) were significantly increased in BM-MSCs compared with the other groups. In conclusion, BM-MSC is the most ideal cell source for human MSCs into GABAergic neuronal differentiation.