The end portions of chromosomes, telomeres, are important in protecting the genes inside. Every time a cell divides, these telomeres become shorter. After multiple cell divisions, the telomeres become so short that the cell either self-dies or wind up in an aged, resting stage. Measurement of telomere lengths therefore provides information about how many times the cells has divided in the past.
This new study is part of the major Betula Project, which, according to the Swedish Research Council, is one of the ten strongest research settings in Sweden and has the goal of studying how the memory changes during aging. It comprises 427 non-demented individuals between the ages of 41 and 81 years. The scientists studied whether individuals with different forms of apolipoprotein E (APOE) have different telomere lengths in their blood cells and whether variations in telomere length is linked to memory capacity, assessed with the help of memory tests. Previous research has described the connection between the form of APOE 4 and cardiovascular disease and dementia. It has also been shown that this variant increases the risk of a type of memory degradation that is most pronounced in older individuals without dementia. This is a degradation of memory in the so-called episodic memory system, which, in simple terms, has the assignment of remembering episodes in life.
In summary the newly published study shows that individuals with APOE 4 have longer telomeres than those with other APOE variants. It was also found that the difference in telomere length between APOE 4 and other APOE variants increased the younger the individuals compared were. In the group that had the variant APOE 4 the individuals with the longest telomeres performed less well on episodic memory tests but not on other tests.
The APOE protein plays a central role in transporting and metabolizing blood fats, but the various forms also appear to have different effects on other processes in the body. The 4 variant is linked with worse blood fats, more inflammation, and increased oxidative stress compared with the 2 and 3 variants. It has previously been shown that both inflammation and oxidative stress lead to shorter telomere length. It was therefore surprising that individuals with the 4 variant had longer telomeres than individuals with the other APOE forms. The longer telomeres support the notion that the cells have undergone a lower number of cell divisions and that the differences in length arose at some time prior to the lower age limit for the study. Such reduced cell division early in life may be an explanation for the worse episodic memory of people with the 4 variant compared with that of individuals with other variants. More studies are needed to confirm these findings and to determine through what mechanisms long telomeres are associated with poorer episodic memory and with any other possible APOE 4-associated processes in the body.
The researchers behind the study are Karl-Fredrik Norrback, Rolf Adolfsson, Göran Roos, and Lars Nyberg at Umeå University; Lars-Göran Nilsson, Stockholm University; and Thomas Karlsson, Linköping University, as well as doctoral candidate Mikael Wikgren. The project coordinator Annelie Nordin has also been important for the conducting of the study.
For more information, please contact: Karl-Fredrik Norrback, MD, PhD, Dept. of Clinical Science, Division of Psychiatry, Umeå University, Mobile phone: +46 (0)70-441 5904, e-mail: firstname.lastname@example.org
Pressofficer Hans Fällman; email@example.com; +46-70 691 28 29
Reference: Wikgren M, Karlsson T, Nilbrink T, Nordfjäll K, Hultdin J, Sleegers K, Van Broeckhoven C, Nyberg L, Roos G, Nilsson LG, Adolfsson R, Norrback KF APOE epsilon4 is associated with longer telomeres, and longer telomeres among epsilon4 carriers predicts worse episodic memory, Neurobiology of Aging, 2010 Apr 13 (10.1016/j.neurobiolaging.2010.03.004).
Hans Fällman | idw
Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)
Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Health and Medicine
13.12.2017 | Physics and Astronomy
13.12.2017 | Life Sciences