Latvian Biomedical Research and Study Centre, Ratsupites iela 1, Riga LV-1067, Latvia; Faculty of Biology, University of Latvia, Jelgavas Street 1, Riga LV-1004, Latvia.
Latvian Biomedical Research and Study Centre, Ratsupites iela 1, Riga LV-1067, Latvia; Riga Stradins University, Dzirciema iela 16, Riga LV-1007, Latvia.
Arch Gerontol Geriatr. 2019 Jul-Aug;83:131-137. doi: 10.1016/j.archger.2019.04.007. Epub 2019 Apr 12.
There are more and more studies on telomere length (TL) and mitochondrial DNA (mtDNA), and it has been proven that these factors play a significant role in the aging of the immune system thereby it is important to understand how it varies in different cell types for more accurate conclusions. The aim of this study was to look into dynamics of mtDNA amount in conjunction with TL in peripheral blood mononuclear cells (PBMC) during aging in comparison with whole blood (WB) cells. Overall, 53 samples were divided into three age groups: 20-39 year age group, 40-59 year age group and 60-79 year age group. MtDNA amount was determined by qPCR TaqMan, and TL was measured by Southern blotting of terminal restriction fragments (TRFs). PBMC had much higher mtDNA copy number (CN) amount than WB samples. Furthermore, with age, it increased in PBMC, while in WB mtDNA CN count did not change. TL in the elderly group was shorter in PBMC fraction than in WB cells. It also looked like that in PBMC TL shortened faster than in WB. In conclusions, it appears that during the aging process both mtDNA CN and TL were more stable in WB than in PBMC fraction where changes were more drastically pronounced, but more studies using larger sample cohorts should be performed to confirm this observation.
越来越多的研究关注端粒长度（TL）和线粒体 DNA（mtDNA），已经证明这些因素在免疫系统衰老中起着重要作用，因此了解它们在不同细胞类型中的变化对于得出更准确的结论非常重要。本研究旨在研究外周血单核细胞（PBMC）中 mtDNA 量与 TL 随年龄变化的动态，与全血（WB）细胞进行比较。总共将 53 个样本分为三个年龄组：20-39 岁年龄组、40-59 岁年龄组和 60-79 岁年龄组。通过 qPCR TaqMan 测定 mtDNA 量，通过 Southern 印迹末端限制片段（TRFs）测量 TL。PBMC 的 mtDNA 拷贝数（CN）明显高于 WB 样本。此外，随着年龄的增长，PBMC 中的 mtDNA CN 增加，而 WB 中的 mtDNA CN 计数没有变化。老年组 PBMC 中的 TL 比 WB 细胞短。看起来 PBMC 中的 TL 比 WB 缩短得更快。总之，在衰老过程中，mtDNA CN 和 TL 在 WB 中比在 PBMC 中更稳定，后者的变化更为明显，但需要进行更多使用更大样本量的研究来证实这一观察结果。
