Researchers at the University of Eastern Finland have discovered new changes occurring in the human brain in the early stages of Alzheimer's disease. The researchers used a multiomic approach to determine RNA, protein, and phosphorylation levels and carried out further neurobioinformatic analyzes on them. The findings, drawing on data from a Finnish biobank of brain tissue samples, were published in Neurobiology of Disease.

In order to find new predictive biomarkers and targets of treatment for Alzheimer's disease, it is crucial to identify accumulation-induced early changes in the brain. Plenty of research has been conducted into changes occurring in the RNA expression of genes in the brain of people with Alzheimer's disease, but very few studies have been focused on the entire protein covering the entire set of proteins expressed in cells.

Protein levels

"Yet, we know that changes in expression are not always translated to the protein level, and we also know that phosphorylation regulates the function of the proteins produced, therefore, it is essential to look at multiple levels of regulation at the same time in order to understand the functional changes taking place in the early stages of Alzheimer's disease, "Postdoctoral Researcher Mikael Marttinen from the University of Eastern Finland explains.

In the newly published study, researchers from the University of Eastern Finland used data available in a unique Finnish biobank of brain tissue samples , where samples are categorized according to the accumulation of phosphorylated tau protein, representing the different stages of Alzheimer's disease.

Genome-wide analysis

By carrying out genome-wide analysis of the samples for changes in RNA, proteins and protein phosphorylation, and by conducting neurobioinformatics analyzes, the researchers managed to demonstrate associations of functional changes in certain brain cell types with Alzheimer's-related accumulation of phosphorylated tau protein.

The researchers also showed that they can be used to classify patients in different stages of the disease .

Further research will focus on whether or not the brain cancer in the different stages of the disease are also visible in cerebrospinal fluid and blood samples, and if these could be used as new predictors of Alzheimer's disease. Furthermore, the changes discovered in the early stages of the disease open up new avenues for potential targets of treatment for Alzheimer's disease.