New Delhi, Dec 30: Immune cells in a female’s brain with Alzheimer’s disease may tend to trigger more activity of genes known to be involved in neuroinflammation than in a male, a study in mice has found which may potentially explain why more females are diagnosed with the neurodegenerative condition.
Alzheimer’s disease is an ageing-related disorder in which speech, memory and thought processes steadily decline with age and can eventually interfere with one’s daily functioning.
Researchers led by those at the University of Rochester, US, found that immune cells in the brain, known as microglia, act differently in male and female mice with Alzheimer’s disease and appear to cause residual harm in the female brain.
Findings published in the Journal of Neuroinflammation show that microglia in female mice respond to amyloid-beta plaques with a stronger interferon response. Amyloid-beta plaques are proteins in the brain that accumulate to form sticky clumps seen in patients with Alzheimer’s disease.
Interferons are a type of signalling protein, or ‘cytokines’, produced by the immune system to fight viruses and bacteria. Studies have shown that interferons can drive neuroinflammation and can damage synapses where two neurons connect.
As immune cells in the brain consume amyloid-beta plaques, they may be exposed to DNA or RNA, mistake it for a virus and cause the cells to release interferon, the researchers said.
The study also found that microglia in female mice leave behind larger and more irregular plaques, which damage more neuronal connections or synapses, compared to those in the male mice’s brains.
“It was surprising to see that female microglia had such a strong interferon response and that these interferon-responsive microglia were taking up more amyloid-beta,” first author Lia Calcines-Rodriguez from the University of Rochester said.
“Interestingly, we did not see differences in amyloid-beta pathology or microglia gene expression in females at different hormonal stages of their cycle, suggesting that hormone fluctuation may not explain these differences,” Calcines-Rodriguez said.
Interferon signalling in the brain’s immune cells could be a potential target for sex-specific, personalised treatment to combat Alzheimer’s disease, she said.
The authors “show that there are sex-specific alterations in (amyloid-beta) plaque morphology and that endogenous hormonal fluctuations across the oestrous cycle do not overtly affect (amyloid-beta) pathology or microglial transcriptomic profiles.” “Furthermore, our study identifies a novel sex-specific enhancement of interferon signalling in female microglia responding to (amyloid-beta), which may constitute a new therapeutic target for personalised medicine in (Alzheimer’s disease),” they said. (PTI)
The post Study in mice with Alzheimer’s finds higher immune response in female brain than in male appeared first on Daily Excelsior.