Division of Psychiatry, Department of Clinical Sciences, Umeå University, Umeå, Sweden.
PLoS One. 2012;7(4):e34292. doi: 10.1371/journal.pone.0034292. Epub 2012 Apr 10.
Telomere length shortens with cellular division, and leukocyte telomere length is used as a marker for systemic telomere length. The hippocampus hosts adult neurogenesis and is an important structure for episodic memory, and carriers of the apolipoprotein E ε4 allele exhibit higher hippocampal atrophy rates and differing telomere dynamics compared with non-carriers. The authors investigated whether leukocyte telomere length was associated with hippocampal volume in 57 cognitively intact subjects (29 ε3/ε3 carriers; 28 ε4 carriers) aged 49-79 yr. Leukocyte telomere length correlated inversely with left (r(s) = -0.465; p = 0.011), right (r(s) = -0.414; p = 0.025), and total hippocampus volume (r(s) = -0.519; p = 0.004) among APOE ε3/ε3 carriers, but not among ε4 carriers. However, the ε4 carriers fit with the general correlation pattern exhibited by the ε3/ε3 carriers, as ε4 carriers on average had longer telomeres and smaller hippocampi compared with ε3/ε3 carriers. The relationship observed can be interpreted as long telomeres representing a history of relatively low cellular proliferation, reflected in smaller hippocampal volumes. The results support the potential of leukocyte telomere length being used as a biomarker for tapping functional and structural processes of the aging brain.
端粒长度随着细胞分裂而缩短，白细胞端粒长度被用作全身端粒长度的标志物。海马体容纳成人神经发生，是情景记忆的重要结构，载脂蛋白 E ε4 等位基因的携带者与非携带者相比，表现出更高的海马体萎缩率和不同的端粒动力学。作者研究了白细胞端粒长度是否与 57 名认知正常的受试者（29 名 ε3/ε3 携带者；28 名 ε4 携带者）的海马体体积有关，这些受试者年龄在 49-79 岁之间。在 APOE ε3/ε3 携带者中，白细胞端粒长度与左侧（r(s)=-0.465；p=0.011）、右侧（r(s)=-0.414；p=0.025）和总海马体体积（r(s)=-0.519；p=0.004）呈负相关，但在 ε4 携带者中则没有。然而，ε4 携带者与 ε3/ε3 携带者表现出的一般相关性模式相吻合，因为与 ε3/ε3 携带者相比，ε4 携带者的端粒通常更长，海马体更小。观察到的关系可以解释为长端粒代表相对较低的细胞增殖历史，反映在较小的海马体体积中。研究结果支持白细胞端粒长度作为检测衰老大脑功能和结构过程的生物标志物的潜力。
