Latest discovery could point to why women are more likely to get Alzheimer’s

Dec 16, 2022
Source: Getty Images.

In a recent study scientists have discovered that an inflammatory immune protein is much more common in the brains of women with Alzheimer’s, offering a hint as to why women are more susceptible to the condition than men.

As part of the Mechanistic insight into female predominance in Alzheimer’s disease based on aberrant protein S-nitrosylation of C3 study, scientists from Scripps Research and Massachusetts Institute of Technology (MIT) used methods to detect S-nitrosylation, which can modify a protein’s function, to quantify proteins modified in 40 postmortem human brains.

Half of the brains examined were from people who had died of Alzheimer’s, while the other half were from people who hadn’t with each group divided equally between males and females.

In the brains affected by Alzheimer’s, the scientists found 1,449 different proteins that had been modified by S-nitrosylation.

Among the proteins modified the most in this manner, there were several associated wit Alzheimer’s, including complement C3, with the levels of S-nitrosylated C3 (SNO-C3) more than six-fold higher in female Alzheimer’s brains compared to male Alzheimer’s brains.

Study senior author Stuart Lipton, MD, PhD said the “new findings suggest that chemical modification of a component of the complement system helps drive Alzheimer’s, and may explain, at least in part, why the disease predominantly affects women.”

“Why women are more likely to get Alzheimer’s has long been a mystery, but I think our results represent an important piece of the puzzle that mechanistically explains the increased vulnerability of women as they age,” Lipton said.

Previous studies have offered some insight as to why SNO-C3 is more common if female brains, with evidence pointing to the female hormone estrogen which has protective properties for the brain.

Researchers hypothesised that the protective properties are reduced when estrogen levels drop with menopause.

The findings adds to recent research which identified a gene that could also be responsible for increasing the risk of Alzheimer’s disease in women.

The study, published in Alzheimer’s Disease & Dementia: The Journal of the Alzheimer’s Association, was conducted by researchers at the School of Public Health, Boston University School of Medicine (MED), and the University of Chicago who identified a connection between a protein-coding gene called MGMT and an increased risk of Alzheimer’s disease in women.

As part of the study, researchers conducted a genome-wide association study (GWAS) for Alzheimer’s in two independent datasets using different study approaches.

One approach analysed dementia in a large extended family of Hutterites, who are a population of central European ancestry who due to their isolated culture and small gene pool, are often studied for genetic determinants of disease. The individuals in this first approach of the study were all women with Alzheimer’s.

The second approach analysed data from a group of 10,340 women who had reduced levels of APOE ε4, a gene considered to hold a strong link to the development of Alzheimer’s in those aged over 65.

Researchers found a significant association between MGMT and the development of Alzheimer’s Disease.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.

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