New research offers hope of a blood test for Alzheimer’s

Tiny snippets of genetic material called microRNA may help with early detection of conditions such as Alzheimer’s disease, according to new research by Indiana University.

The study, which has been published in the journal Nature Scientific Reports, found that changes in microRNA are detectable in mice long before they start to show symptoms from neurodegeneration. These microRNA changes may represent an early warning sign for the condition.

Hui-Chen Lu, the study’s lead author, said: ‘Identifying biomarkers early in a disease is important for diagnosing the condition, and following its progression and response to treatment. You need something that can predict your future.’

There is currently no treatment to stop or reverse the effects of neurodegenerative diseases such as Alzheimer’s, Parkinson’s, ALS or Huntington’s.

Due to their stability in urine and blood, there is growing interest in using microRNA as biomarkers for disease prediction and diagnosis. Lu’s study is an early step to learn whether microRNA can be used to detect neurodegenerative disorders.

To explore this question, Lu and colleagues looked at microRNA and messenger RNA in two groups: a healthy group and a group genetically modified to develop symptoms of dementia. The team found the highest level of deviation from normal levels was found in the microRNA of the dementia group before their physical symptoms developed.

‘Higher levels of pre-symptomatic microRNA dysregulation are significant because it strongly suggests that it may have a role in changes in the brain in later stages,’ Lu said.

The team then compared the microRNA changes to the messenger RNA changes to identify biological pathways affected by microRNA dysregulation. Their analysis suggested that changes in microRNA affected pathways related to immunity in the dementia-prone model.

In response, the team then conducted additional tests to study a specific type of microRNA that was elevated in those with dementia.

They found that introducing this microRNA into the brain triggered a significant neuroinflammation. The result is important since many other studies have shown that chronic inflammation contributes to many types of disease, including neurodegeneration.

The next step will be to learn whether microRNA 142 is easily detectable through a blood test, Lu said.