Before memories fade: the protein that predicts Alzheimer's 20 years earlier
A study published in Cell Reports Medicine by Shilin Luo and colleagues puts the spotlight on a protein that opens up new scenarios for early diagnosis
Key points
Everyone knows it as the 'memory disease'. But in reality, Alzheimer's disease starts long before one begins to forget the names of things or people or gets lost on the way home. The problem creeps in quietly, even 20 years before symptoms appear. And when the memory falters, the damage is often already in an advanced stage.
That is why today the real challenge is not just to cure Alzheimer's, but to discover it as early as possible, so that the available therapies can reach their full potential. But to do so, we need to track down the 'whispers' of the disease, the spies of something moving in the shadows.
The results of a Chinese study
And a study recently published in Cell Reports Medicine by Shilin Luo and colleagues turns the spotlight on a protein defined by an anonymous acronym - PPP2R5C - that could become the Columbus egg of early diagnosis. The researchers observed that its levels in the blood progressively decrease already in the early stages of the disease, long before the Tau protein - one of the main contributors to neuronal damage - takes on a pathological role.
To understand why this finding is important, we need to take a step back. Alzheimer's is characterised by two major changes: the accumulation of beta-amyloid outside the neurons and the formation of tangles of altered tau protein inside nerve cells. It is precisely Tau, when excessively 'phosphorylated', that loses its stabilising function within neurons and contributes to their death.
This is where PPP2R5C comes in. This protein is a subunit of a key enzyme that in the brain is responsible for 'cleaning up' tau from excess phosphorylation. If PPP2R5C decreases, the enzyme PP2A functions less efficiently. And pathological tau is more likely to accumulate, leading to neuronal death.
