Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York 11794, USA.
Anal Chem. 2010 Apr 1;82(7):2711-6. doi: 10.1021/ac1002728.
Polyunsaturated fatty acids are essential to brain functions such as membrane fluidity, signal transduction, and cell survival. It is also thought that low levels of unsaturated lipid in the brain may contribute to Alzheimer's disease (AD) risk or severity. However, it is not known how accumulation of unsaturated lipids is affected in different regions of the hippocampus, which is a central target of AD plaque pathology, during aging. In this study, we used Fourier transform infrared imaging (FTIRI) to visualize the unsaturated lipid content in specific regions of the hippocampus in the PSAPP mouse model of AD as a function of plaque formation. Specifically, the unsaturated lipid content was imaged using the olefinic =CH stretching mode at 3012 cm(-1). The axonal, dendritic, and somatic layers of the hippocampus were examined in the mice at 13, 24, 40, and 56 weeks old. Results showed that lipid unsaturation in the axonal layer was significantly increased with normal aging in control (CNT) mice (p < 0.01) but remained low and relatively constant in PSAPP mice. Thus, these findings indicate that unsaturated lipid content is reduced in hippocampal white matter during amyloid pathogenesis and that maintaining unsaturated lipid content early in the disease may be critical in avoiding progression of the disease.
多不饱和脂肪酸对大脑功能至关重要，如膜流动性、信号转导和细胞存活。人们还认为，大脑中不饱和脂质水平低可能导致阿尔茨海默病（AD）的风险或严重程度增加。然而，尚不清楚在衰老过程中，AD 斑块病理学的中枢靶区——海马体的不同区域中，不饱和脂质的积累是如何受到影响的。在这项研究中，我们使用傅里叶变换红外成像（FTIRI）来可视化 AD 的 PSAPP 小鼠模型中海马体特定区域的不饱和脂质含量，作为斑块形成的函数。具体来说，使用 3012cm-1 的烯键 =CH 伸缩模式对不饱和脂质含量进行成像。在 13、24、40 和 56 周龄的小鼠中，检查了海马体的轴突、树突和体细胞层。结果表明，在对照（CNT）小鼠中，随着正常衰老，轴突层中的脂质不饱和显著增加（p<0.01），但在 PSAPP 小鼠中保持低且相对稳定。因此，这些发现表明，在淀粉样蛋白发病过程中，海马体白质中的不饱和脂质含量减少，并且在疾病早期维持不饱和脂质含量可能对于避免疾病进展至关重要。
