TL;DR
Get workout gear delivered free with Prime
- Fast, free delivery on millions of items
- Prime Video, Amazon Music and more included
- Member-only deals all year
A study of human brain tissue and experiments in mice linked lower NRF2 activity in oligodendrocytes to abnormal myelin, loss of large nerve fibers and faster cognitive decline. The findings point to a possible treatment target, but they do not show that drugs acting on NRF2 can prevent age-related decline in people.
Researchers led by the University of Edinburgh and the UK Dementia Research Institute have linked dysfunction in brain cells that maintain nerve insulation to faster cognitive decline in older age. Their study, published in Nature Medicine, connects lower levels of the protective protein NRF2 in these cells with abnormal myelin and damage to nerve fibers, while experiments in mice provide evidence that reducing NRF2 can cause similar changes.
The team studied members of the Lothian Birth Cohort 1936, whose cognitive abilities had been tracked over many decades. Of 1,091 people enrolled, 866 completed additional testing after age 70. Researchers assessed memory, processing speed and spatial ability between ages 70 and 82. Most participants experienced some decline, but the pace differed, allowing the researchers to compare brain tissue from people with different rates of change.
In tissue collected after death from a subset of participants, faster decline was associated with fewer large nerve fibers and an abnormal accumulation of myelin, the coating that helps electrical signals travel along nerve fibers. The researchers said these tissue changes tracked with the rate of cognitive decline, rather than simply with cognitive performance at one age. The association does not, by itself, establish that the tissue changes caused the decline.
The researchers focused on oligodendrocytes, the cells that produce and maintain myelin. People with more severe decline had lower levels of NRF2 in these cells. In mice, selectively reducing NRF2 in oligodendrocytes led to excessive myelin, loss of large nerve fibers and less improvement on cognitive tests as the animals aged. These experiments support a possible causal role for the pathway in mice, but do not establish how it operates in people.
A Possible Target in Myelin Cells
The findings suggest that cells usually understood as supportive may contribute to age-related brain changes when their protective functions falter. That shifts attention beyond nerve cells themselves to the oligodendrocytes that maintain myelin, and to how their condition might affect communication across the brain.
The study also identifies NRF2 as a possible therapeutic target. Medicines that affect this pathway are already used for other neurological conditions, including multiple sclerosis. However, the research does not show that those drugs prevent cognitive decline in older adults, nor does it establish that a treatment safe or effective for one condition would work for another. The potential is a basis for further research, not a treatment recommendation.
As an affiliate, we earn on qualifying purchases.
From Cohort Records to Mouse Tests
The human findings draw on a cohort with unusually long cognitive records: participants’ abilities had been assessed from childhood into older age. Researchers could compare changes over time with later examinations of brain tissue, helping them look for biological features associated with different rates of decline.
That human analysis was observational. The mouse experiments added a separate line of evidence by reducing NRF2 specifically in oligodendrocytes and examining the effects. Together, the approaches connect a pattern seen in people with a mechanism that could be tested experimentally, but they do not show that all cognitive decline in aging stems from this pathway.
The research builds on the known role of myelin in nerve signaling. Its contribution is the suggestion that abnormal myelin and dysfunction in the cells maintaining it may be associated with how quickly cognition changes, rather than serving only as background features of an aging brain.
“As the prevalence of cognitive decline is rising with an aging population and no current treatments exist, we are excited about this work as it points to a potential strategy for new therapeutic strategies to preserve cognitive ability in aging.”
— Veronique Miron, MRC Senior Non-Clinical Fellow and UK Dementia Research Institute group leader at the University of Edinburgh and St. Michael’s Hospital
As an affiliate, we earn on qualifying purchases.
Human Treatment Evidence Is Missing
The study does not establish that reduced NRF2 is the cause of cognitive decline in people. The human tissue analysis shows an association, while the experiments that manipulated NRF2 were conducted in mice. The supplied report does not specify how many participants’ post-mortem tissue was examined or provide effect sizes for the reported associations.
It is also unclear whether NRF2-targeting medicines used for other conditions could safely and effectively address age-related cognitive decline. The researchers have identified a pathway for further study; clinical benefit in older adults has not been demonstrated. The findings also do not show that the pathway explains every form or cause of cognitive change with age.
oligodendrocyte support supplement
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Testing the Pathway in People
Further research will need to determine whether changes in oligodendrocyte NRF2 activity precede cognitive decline in people and whether modifying the pathway can protect nerve fibers. Any move toward repurposing existing medicines would require studies assessing the right patients, dose, timing, safety and cognitive outcomes.
Until clinical trials test those questions, the work should be understood as a biological finding and a possible treatment direction. No change to medication or care for cognitive concerns follows from this study alone.
As an affiliate, we earn on qualifying purchases.
Key Questions
Which brain cells are implicated in the study?
The researchers studied oligodendrocytes, cells that produce and maintain myelin, the coating around nerve fibers.
What is NRF2, and what did the study find?
NRF2 is a protein involved in regulating cellular defenses and normal function. The study reported lower NRF2 levels in oligodendrocytes in people with greater cognitive decline, and found that reducing it in mouse oligodendrocytes caused related changes to myelin and nerve fibers.
Does the study prove that abnormal myelin causes cognitive decline in people?
No. The human results show an association between tissue features and the rate of decline. Experiments in mice support a possible mechanism, but do not prove the same causal process in people.
The study raises that possibility because some medicines act on the NRF2 pathway, but it did not test such treatment in older adults. Whether an existing medicine could help, and whether it would be safe and effective for this purpose, remains unknown.
Source: rss
Halloween Picks
halloween
As an affiliate, we earn on qualifying purchases.
