Department of Spine Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
J Cell Biochem. 2013 Jan;114(1):144-51. doi: 10.1002/jcb.24311.
The brain-derived neurotrophic factor (BDNF) participates in the regulation of cortical neurons by influencing the release of glutamate. However, the specific mechanisms are unclear. Hence, we isolated and cultured the cortical neurons of Sprague Dawley rats. Specific inhibitors of TrkB, Src, PLC-γ1, Akt, and MEK1/2 (i.e., K252a, PP2, U73122, LY294002, and PD98059, respectively) were used to treat cortical neurons and to detect the glutamate release from cortical neurons stimulated with BDNF. BDNF significantly increased glutamate release, and simultaneously enhanced phosphorylation levels of TrkB, Src, PLC-γ, Akt, and Erk1/2. For BDNF-stimulated cortical neurons, K252a inhibited glutamate release and inhibited the phosphorylation levels of TrkB, Src, PLC-γ, Erk1/2, and Akt (P < 0.05). PP2 reduced the glutamate release from BDNF-stimulated cortical neurons (P < 0.05) and inhibited the phosphorylation levels of TrkB and PLC-γ1 (P < 0.05). However, PP2 had no effect on the phosphorylation levels of Erk1/2 or Akt (P > 0.05). U73122 inhibited the glutamate release from BDNF-stimulated cortical neurons, but had no influence on the phosphorylation levels of TrkB, Src, Erk1/2, or Akt (P > 0.05). LY294002 and PD98059 did not affect the BDNF-stimulated glutamate release and did not inhibit the phosphorylation levels of TrkB, Src, or PLC-γ1. In summary, BDNF stimulated the glutamate release from cortical neurons via the TrkB/Src/PLC-γ1 signaling pathway.
脑源性神经营养因子（BDNF）通过影响谷氨酸的释放参与皮质神经元的调节。然而，具体的机制尚不清楚。因此，我们分离并培养了 Sprague Dawley 大鼠的皮质神经元。使用 TrkB、Src、PLC-γ1、Akt 和 MEK1/2 的特异性抑制剂（即 K252a、PP2、U73122、LY294002 和 PD98059）分别处理皮质神经元，并检测 BDNF 刺激皮质神经元时谷氨酸的释放。BDNF 显著增加谷氨酸释放，并同时增强 TrkB、Src、PLC-γ、Akt 和 Erk1/2 的磷酸化水平。对于 BDNF 刺激的皮质神经元，K252a 抑制谷氨酸释放并抑制 TrkB、Src、PLC-γ、Erk1/2 和 Akt 的磷酸化水平（P<0.05）。PP2 降低 BDNF 刺激的皮质神经元的谷氨酸释放（P<0.05）并抑制 TrkB 和 PLC-γ1 的磷酸化水平（P<0.05）。然而，PP2 对 Erk1/2 或 Akt 的磷酸化水平没有影响（P>0.05）。U73122 抑制 BDNF 刺激的皮质神经元的谷氨酸释放，但对 TrkB、Src、Erk1/2 或 Akt 的磷酸化水平没有影响（P>0.05）。LY294002 和 PD98059 不影响 BDNF 刺激的谷氨酸释放，也不抑制 TrkB、Src 或 PLC-γ1 的磷酸化水平。综上所述，BDNF 通过 TrkB/Src/PLC-γ1 信号通路刺激皮质神经元的谷氨酸释放。
