Imaging Membrane Lipids During Neurodegeneration

细胞的质膜主要由脂质组成，是一种流体动力学结构，具有改变其组成和密度以调节和反应外部环境的能力。一种方法是通过形成称为脂筏的特殊膜微域。由于其结构的可变性，成像脂质（和脂筏）提出了挑战，特别是当试图通过使用标准成像方法检测它们时。因此，本提案将采用新颖和创新的方法来检测和表征膜脂的组成，包括存在于脂筏中的膜脂。这一建议将进一步表征膜脂组成如何在不同的神经毒性刺激下发生变化，并将膜组成的变化与神经元细胞死亡的易感性联系起来。在此，我们提出了两种创新的方法，在体外和体内脑损伤模型中成像神经元膜脂成分，具体目的如下：(1)在体外研究应激后脂筏结构域的反应；(2)使用成像质谱法成像脂筏结构域内的神经节苷脂和其他鞘脂。这两个目标都是可以实现的，并且可以在NSERC发现基金的5年时间框架内完成。MSI是一种相对较新的成像技术，尽管有几个加拿大机构使用MALDI-TOF分析样品，但很少使用MALDI-TOF原位成像脂质。我们认为这是NSERC发现基金提案的一个明显优势。这项研究计划的影响将超出我们实验室的研究结果。我们希望为这些成像技术的使用建立一个强有力的理论基础，特别是在IMS方面，并使它们可供大学社区使用。这将为不同研究小组之间的科学协同作用提供一个物理来源。我们认为，这项研究计划的影响也将通过高素质人才的特殊培训潜力来感受到。通过提供一个独特的培训环境，学员可以学习体外和体内技术，我们将提供坚实的培训和支持基础，帮助他们取得成功。

The plasma membrane of cells, composed mainly of lipids, is a fluid dynamic structure that has the ability to change its composition and density to adjust and react to its external environment. One way to do this is through the formation of specialized membrane micro domains called lipid rafts. Due to their variability of structure, imaging lipids (and lipid rafts) have posed a challenge, especially when trying to detect them by using standard imaging methods. Therefore this proposal will employ novel and innovative methodology to detect and characterize the composition membrane lipids, including those present in lipid rafts. This proposal will further characterize how membrane lipid composition changes in response to different neuro-toxic stimuli and will correlate shifting membrane composition with vulnerability to neuron cell death. Here we propose two innovative means of imaging components of neuronal membrane lipids in vitro and in vivo models of brain injury with the following specific aims: (1) Examine the response of lipid raft domains following stress in vitro and (2) Image gangliosides and other sphingolipids within lipid raft domains using imaging mass spectrometry. Both these aims are achievable and can be completed within the 5 year time-frame of an NSERC Discovery Grant. MSI is a relatively new imaging technique, and although there are several Canadian intuitions using MALDI-TOF analysis of samples, very few are using MALDI-TOF to image lipids in situ. We feel this is a distinct advantage of this NSERC Discovery Grant proposal. The impact of this research program will extend beyond the findings from our laboratory. We hope to build a strong rationale for the use of these imaging techniques, especially with respect to IMS and make them available to the University community. This will provide a physical source where scientific synergy can take place among different research groups. We feel that the impact of this research program will also be felt through the exceptional training potential of highly qualified personnel. By providing a unique training environment where trainees can learn both in vitro and in vivo techniques, we will provide a solid foundation of training and support to help them become successful.