New signs of brain aging discovered
Scientists from America and the UK have managed to establish how the expression of genes in different parts of the brain changes as we age.
The study of gene expression suggests that the aging of the human brain is determined by a complex of changes at the molecular level.
The genes responsible for aging are known to scientists. When gene expression changes, the protein composition of the cell changes, which means that the functions and properties of tissues change. Until now, no clear pattern has been established between changes in gene expression and the areas of the cerebral cortex where they occur. In this work, scientists were able to characterize changes in the expression of more than 100 genes associated with aging. To do this, ten brain regions were studied in 480 people aged 16 to 106 years.
It has been shown that the genes of neuroglia cells – oligodendrocytes and astrocytes – cells that bind to neurons and regulate their activity increase their expression with aging, especially in the hippocampus, responsible for the translation of short-term memory into long-term memory, and the substantia nigra, which plays an important role in the control of motor functions. The expression of microglia and endothelium genes – a thin layer of cells on the inner surface of blood vessels – also increases.
By methods of immunohistochemical analysis – selective labeling of proteins in a tissue sample to determine the level of gene expression – it was shown that the number of oligodendrocytes and nerve inclusions in the cerebral cortex decreases.
These data show that the expression of some genes increases, and some decreases. That is, changes in the brain as we age are not unambiguous.
Such studies allow the expression of neuroglia and endothelium genes to determine the biological age of the organism quite accurately, which gives direction to the following studies – according to scientists, it is necessary to investigate the relationship of neuron-glial mechanisms with aging and with the development of senile diseases.
The work was published in the journal Cell Reports (Soreq et al., Major Shifts in Glial Regional Identity Are a Transcriptional Hallmark of Human Brain Aging).
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18.01.2017