The mechanism of irreversible aging of the brain


Photo: Eric Gaillard / Reuters

Biologists at the Massachusetts Institute of technology (USA) found that with age, some neurons there is an accumulation of short fragments of RNA that are formed under oxidative stress. This process leads to irreversible changes in the brain. About the study reported in a press release on MedicalXpress.

According to scientists, the accumulation of short-chain RNA molecules is a marker for neurodegenerative diseases, the risk of which increases with age. It also reduces the amount of synthesized proteins that are important for the functions of the Central nervous system. This phenomenon was observed both in mouse and human brain, including a region called the striatum (striped body). This anatomical structure is responsible for muscle function and is associated with Parkinson’s and Huntington’s.

There are different types of RNA, including messenger RNA (mRNA). the mRNA performs the function of transfer of genetic information from DNA to the ribosomes, which build protein chains in accordance with the sequence of nucleotides in RNA. The researchers analyzed RNA in the projection spiny neurons D1 and D2 in young and old mice. This type of neurons is 95 percent of all neurons in the striatum.

It turned out that in D1 neurons in older animals about 400 genes produce only short fragments of mRNA called the 3’untranslated regions. They were attached to the ribosome, preventing the correct synthesis of proteins. The failure cause is oxidative stress caused by increased formation of reactive oxygen species in neurons. The radicals react with the active site of the enzyme ABCE1, which separates mRNA from the ribosomes after completion of protein synthesis.

The researchers also found a similar process in the tissues of the human brain, including the frontal lobe of the cerebral cortex.

Video, photo All from Russia.


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