Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada.
Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada.
Physiol Rep. 2024 Aug;12(16):e70001. doi: 10.14814/phy2.70001.
Brain-derived neurotrophic factor (BDNF) content and signaling has been identified as one potential regulator of amyloid precursor protein (APP) processing. Recently published work has demonstrated that BDNF reduces BACE1 activity while also elevating the inhibition of GSK3β in the prefrontal cortex of male C57BL/6J mice. These results provide evidence that BDNF alters APP processing by reducing BACE1 activity, which may act through GSK3β inhibition. The purpose of this study was to further explore the role of GSK3β in BDNF-induced regulation on BACE1 activity. We utilized a cell culture and an in vitro activity assay model to pharmacologically target BDNF and GSK3β signaling to confirm its involvement in the BDNF response. Treatment of differentiated SH-SY5Y neuronal cells with 75 ng/mL BDNF resulted in elevated pTrkB content, pAkt content, pGSK3β content, and reduced BACE1 activity. An in vitro BACE1 activity assay utilizing mouse prefrontal cortex (n = 6/group) supplemented with BDNF, BDNF + ANA12 (Trkb antagonist), or BDNF + wortmannin (Akt inhibitor) demonstrated that BDNF reduced BACE1 activity; however, in the presence of TrkB or Akt inhibition, this effect was abolished. An in vitro ADAM10 activity assay utilizing mouse prefrontal cortex (n = 6/group) supplemented with BDNF, BDNF + ANA12 (Trkb antagonist), or BDNF + wortmannin (Akt inhibitor) demonstrated that BDNF did not alter ADAM10 activity. However, inhibiting BDNF signaling reduced ADAM10 activity. Collectively these studies suggest that GSK3β inhibition may be necessary for BDNF-induced reductions in BACE1 activity. These findings will allow for the optimization of future therapeutic strategies by selectively targeting TrkB activation and GSK3β inhibition.
脑源性神经营养因子（BDNF）的含量和信号转导已被确定为调节淀粉样前体蛋白（APP）加工的潜在调节剂之一。最近发表的研究工作表明，BDNF 降低了 BACE1 的活性，同时也提高了雄性 C57BL/6J 小鼠前额叶皮层中 GSK3β 的抑制作用。这些结果提供了证据表明，BDNF 通过降低 BACE1 的活性来改变 APP 的加工，这可能是通过 GSK3β 的抑制作用来实现的。本研究的目的是进一步探讨 GSK3β 在 BDNF 诱导的 BACE1 活性调节中的作用。我们利用细胞培养和体外活性测定模型，对 BDNF 和 GSK3β 信号进行药理学靶向处理，以确认其参与 BDNF 反应。用 75ng/ml BDNF 处理分化的 SH-SY5Y 神经元细胞，导致 pTrkB 含量、pAkt 含量、pGSK3β 含量升高，BACE1 活性降低。利用补充 BDNF、BDNF+ANA12（TrkB 拮抗剂）或 BDNF+wortmannin（Akt 抑制剂）的小鼠前额叶皮层进行体外 BACE1 活性测定，结果表明 BDNF 降低了 BACE1 的活性；然而，在 TrkB 或 Akt 抑制存在的情况下，这种作用被消除。利用补充 BDNF、BDNF+ANA12（TrkB 拮抗剂）或 BDNF+wortmannin（Akt 抑制剂）的小鼠前额叶皮层进行体外 ADAM10 活性测定，结果表明 BDNF 不改变 ADAM10 的活性。然而，抑制 BDNF 信号降低了 ADAM10 的活性。这些研究表明，GSK3β 的抑制可能是 BDNF 诱导的 BACE1 活性降低所必需的。这些发现将允许通过选择性靶向 TrkB 激活和 GSK3β 抑制来优化未来的治疗策略。
