Fukushima Teruyuki, Liu Rong-Yu, Byrne John H
Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, The University of Texas Medical School at Houston, Houston, Texas 77030, USA.
Hippocampus. 2007;17(1):5-9. doi: 10.1002/hipo.20243.
Transforming growth factor-betas (TGF-betas) are widely expressed and play roles as multifunctional growth factors and regulators of key events in development, disease, and repair. However, it is not known whether TGF-betas affect the plasticity of hippocampal neurons. As a first step to address this issue, we examined whether TGF-beta2 modulated the electrophysiological and biochemical properties of cultured hippocampal neurons. We found that prolonged 24 h treatment with TGF-beta2 induced facilitation of evoked postsynaptic currents (ePSCs). This facilitation was associated with a decrease in short-term synaptic depression of ePSCs and increases in both the amplitude and frequency of spontaneous miniature postsynaptic currents (mPSCs). The long-term changes of ePSCs and mPSCs may be associated with cAMP response element-binding protein (CREB), which has been previously implicated in long-term potentiation. Immunofluorescence techniques and Western blot analysis both revealed that TGF-beta2 enhanced the phosphorylation of CREB. Together, these results suggest that TGF-beta2 may play a role in the cascade of events underlying long-term synaptic facilitation in hippocampus, and that CREB may be an important mediator of these effects.
转化生长因子-β（TGF-β）广泛表达，并作为多功能生长因子以及发育、疾病和修复过程中关键事件的调节因子发挥作用。然而，尚不清楚TGF-β是否会影响海马神经元的可塑性。作为解决该问题的第一步，我们研究了TGF-β2是否调节培养的海马神经元的电生理和生化特性。我们发现，用TGF-β2进行24小时的长时间处理会诱导诱发突触后电流（ePSC）的易化。这种易化与ePSC的短期突触抑制的降低以及自发微小突触后电流（mPSC）的幅度和频率的增加有关。ePSC和mPSC的长期变化可能与cAMP反应元件结合蛋白（CREB）有关，CREB先前已被证明与长期增强有关。免疫荧光技术和蛋白质印迹分析均显示，TGF-β2增强了CREB的磷酸化。总之，这些结果表明，TGF-β2可能在海马长期突触易化的一系列事件中发挥作用，并且CREB可能是这些作用的重要介导因子。
