Age- And Cell-Type-Specific Effects Of Histone Variant H2Be In The Brain
Our brains are incredibly complex, and their function relies on the precise regulation of our genes. This regulation involves special proteins called histones, which act like spools around which our DNA is wound. Sometimes, these standard histones are replaced by “variant” forms that can fine-tune how genes are turned on or off. One such variant, called H2BE, has been found to be particularly important in the brain.
New research shows that H2BE becomes more abundant in two key types of brain cells—neurons (which transmit information) and astrocytes (which support neurons)—as we age. In younger brains, H2BE is essential for the proper functioning of synapses, the connections between neurons, by promoting the expression of genes vital for these connections. It ensures that our brain cells can communicate effectively.
However, as the brain ages, the role of H2BE becomes more nuanced. While its absence still affects synaptic genes in neurons, it also appears to temper some of the age-related changes in gene activity that occur in both neurons and astrocytes. Interestingly, experiments in aging mice revealed that losing H2BE had a dual effect on memory: it impaired the ability to form long-term memories but surprisingly enhanced working memory, which is crucial for temporary information storage and manipulation. These findings highlight a fascinating link between these histone variants, the changes in gene expression that happen as we age in different brain cells, and our memory abilities.
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