Immune system may protect against Alzheimer's

July, 2012

New studies involving genetically-engineered mice and older adult humans support a connection between the immune system and cognitive impairment in old age.

A number of studies have come out in recent years linking age-related cognitive decline and dementia risk to inflammation and infection (put inflammation into the “Search this site” box at the top of the page and you’ll see what I mean). New research suggests one important mechanism.

In a mouse study, mice engineered to be deficient in receptors for the CCR2 gene — a crucial element in removing beta-amyloid and also important for neurogenesis — developed Alzheimer’s-like pathology more quickly. When these mice had CCR2 expression boosted, accumulation of beta-amyloid decreased and the mice’s memory improved.

In the human study, the expression levels of thousands of genes from 691 older adults (average age 73) in Italy (part of the long-running InCHIANTI study) were analyzed. Both cognitive performance and cognitive decline over 9 years (according to MMSE scores) were significantly associated with the expression of this same gene. That is, greater CCR2 activity was associated with lower cognitive scores and greater decline.

Expression of the CCR2 gene was also positively associated with the Alzheimer’s gene — meaning that those who carry the APOE4 variant are more likely to have higher CCR2 activity.

The finding adds yet more weight to the importance of preventing / treating inflammation and infection.

Reference: 

[2960] Harries, L. W., Bradley-Smith R. M., Llewellyn D. J., Pilling L. C., Fellows A., Henley W., et al.
(2012).  Leukocyte CCR2 Expression Is Associated with Mini-Mental State Examination Score in Older Adults.
Rejuvenation Research. 120518094735004 - 120518094735004.

Naert, G. & Rivest S. 2012. Hematopoietic CC-chemokine receptor 2-(CCR2) competent cells are protective for the cognitive impairments and amyloid pathology in a transgenic mouse model of Alzheimer's disease. Molecular Medicine, 18(1), 297-313.

El Khoury J, et al. 2007. Ccr2 deficiency impairs microglial accumulation and accelerates progression of Alzheimer-like disease. Nature Medicine, 13, 432–8.

Related News

A study (“Midlife in the United States”) assessing 3,343 men and women aged 32-84 (mean age 56), of whom almost 40% had at least a 4-year college degree, has found evidence that frequent cognitive activity can counteract the detrimental effect of poor education on age-related cognitive decline.

Previous research has shown that older adults are more likely to incorrectly repeat an action in situations where a

It’s now well established that older brains tend to find it harder to filter out irrelevant information. But now a new study suggests that that isn’t all bad.

A study involving 155 women aged 65-75 has found that those who participated in resistance training once or twice weekly for a year significantly improved their selective attention (maintaining mental focus) and conflict resolution (as well as muscular function of course!), compared to those who

A number of rodent studies have shown that blueberries can improve aging memory; now for the first time, a human study provides evidence.

A study involving 57 cognitively healthy older adults has found that those who showed decreased memory performance two years later (20 of the 57) had higher baseline levels of phosphorylated tau231 in the

Midlife hypertension has been confirmed as a risk factor for the development of dementia in late life, but there have been conflicting findings about the role of late-life hypertension.

By following 597 Alzheimer’s patients over 15 years, researchers have determined that a simple progression rate can be calculated at the initial visit, using symptom onset and present performance, and that this can reliably identify slow, intermediate and rapid progression.

A survey of more than 100 studies involving PIB-PET, a diagnostic tool that involves injecting a radiotracer called

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news
Error | About memory

Error

The website encountered an unexpected error. Please try again later.