Brake for dementia
Alzheimer's disease is the main cause of dementia, and existing therapeutic strategies cannot prevent, slow down or cure it. The disease is characterized by memory impairment caused by degeneration and death of neurons in different areas of the brain, including the hippocampus, in which memories are formed. Researchers from the Netherlands Institute of Neuroscience (NIN) have discovered and tested a way to rejuvenate the brain and counteract memory deterioration.
New cells in the old brain
Previously, several studies have demonstrated the presence of new cells in the hippocampus of elderly people, which proves that the so-called adult neurogenesis continues throughout life. This process is associated with many aspects of learning and memory in both animals and humans. More intensive adult neurogenesis in patients with Alzheimer's disease appears to correlate with better cognitive performance at the end of life. This may indicate that new neurons in the human brain form a kind of cognitive reserve, which subsequently provides resistance to memory loss. In a new study, a group from NIN studied whether enhancing adult neurogenesis can prevent or weaken the clinical manifestations of dementia in Alzheimer's disease.
Small, yes, he was good
Seven years ago, while studying miRNA-132, which is expressed in the human brain, the research team came across a rather unexpected circumstance: the expression of this molecule was reduced in the brains of patients with Alzheimer's disease. miRNA-132 probably controls the homeostasis of neuronal stem cells in the central nervous system.
To find out whether miRNA-132 can regulate neurogenesis in the hippocampus of healthy people and patients with Alzheimer's disease, the researchers used various mouse models of Alzheimer's disease, cultured human neuronal stem cells and postmortem human brain tissue. They found that this miRNA is necessary for adult neurogenesis in the hippocampus, and a decrease in its level in the brain of adult mice or in human neuronal stem cells stops the process of creating new neurons.
However, increasing the concentration of miRNA-132 by intraventricular injection of a synthetic oligonucleotide mimicking miR-132 in the brains of mice with Alzheimer's disease restores neurogenesis and counteracts memory impairment.
The data obtained prove the concept of the supposed therapeutic potential of enhancing adult neurogenesis in Alzheimer's disease. The authors' next goal is to evaluate the efficacy and safety of targeting miRNA–132 as a therapy for Alzheimer's disease.
Article by H.Walgrave et al. Restoring miR-132 expression rescues adult hippocampal neurogenesis and memory deficits in Alzheimer's disease is published in the journal Cell Stem Cell.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru according to the Netherlands Institute for Neuroscience: 'Rejuvenating' the Alzheimer’s brain.