Vol.30 No.3 (2008 June): 387-391

Enhancement of Survival, Proliferation and Differentiation into Neurons of Neural Progenitor Cells Isolated from Rats Hippocampus by Brain Derived Neurotrophic Factor

Ting-Song Li, Li Jiang*, Heng-Sheng Chen, Xiao-Ping Zhang

(Department of Neurology, the Children's Hospital, Chongqing Medical University, Chongqing 400014, China)

Abstract The objective of the study is to explore the effect of brain derived neurotrophic factor (BDNF) on the neural progenitor/stem cells (NPCs) of rat hippocampus. NPCs were obtained from Wistar rats at embryonic day 15-16 and cultured in serum-free medium, then the neurospheres were harvested, fixed and immunostained for nestin (the protein marker of stem cells); NPCs were induced to differentiate with 1% fetal calf serum containing medium; The single NPC was obtained by a mechanical dissociation and grown for 3 days in medium containing BDNF at the concentration of 10?00 ng/ml then the number of neurosphere were counted and the diameter of neurosphere were measured; Tunel staining positive cells and the level of lactic acid dehydrogenase (LDH) in culture medium were used to evaluate the effect of BDNF on the NPCs survival; β tubulin III (Tuj-1) immunostaining was used to label the neurons differentiated from NPCs, and the percentage of Tuj-1 positive cells among DAPI positive cells in the BDNF and control group were compared. Additionally, the length of neurite in Tuj-1 immunostaining positive cells was measured. The results showed that nestin-positive NPCs exhibited the ability of self-proliferation and could be induced to differentiate into neurons and astrocytes. BDNF at the concentration of 10-200 ng/ml enhanced the proliferation of NPCs at the cell density of 5กม10⁵ cells/ml, while 40 ng/ml BDNF exhibited the strongest proliferation enhancement; Diameter of newly formed neurosphere with 40 ng/ml BDNF was increased obviously while the apoptosis rate (Tunel⁺/DAPI⁺) and LDH leakage of 40 ng/ml BDNF group was significantly decreased compared with the control group. In 40 ng/ml BDNF group, more neurons (Tuj-1⁺ cells) were observed and total neuritic length in Tuj-1⁺ cells were significantly longer, compared to the control group. Our study suggest that BDNF has a neuroprotective effect, can promote NPCs proliferation and induce them differentiation into neurons.

Key words neural progenitor/stem cells; hippocampus; brain derived neurotrophic factor; proliferation; differentiation

Received: November 19, 2007 Accepted: January 29, 2008
This work was supported by the National Natural Science Foundation of China (No.30672217) and Science Foundation of Chongqing Health Bureau (No.06-2-158)
*Corresponding author. Tel: 86-23-63624424, E-mail: dr_jiangli@126.com