Alpha-synuclein and tau protein are both associated with neurodegenerative diseases, but they have distinct properties, functions, and pathological roles:
1. Normal Function:
Alpha-synuclein: Found predominantly in neurons, particularly in presynaptic terminals, alpha-synuclein plays a role in regulating synaptic vesicle trafficking and neurotransmitter release.
Tau protein: Tau is a microtubule-associated protein found mainly in neurons, where it stabilizes microtubules in axons, aiding in the proper structure and function of neurons by supporting intracellular transport.
2. Pathological Role:
Alpha-synuclein: In neurodegenerative diseases, alpha-synuclein can misfold and aggregate into insoluble fibrils, forming Lewy bodies. This accumulation is primarily associated with Parkinson’s disease, dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), collectively known as synucleinopathies.
Tau protein: Tau can become hyperphosphorylated, leading to the formation of insoluble tangles, known as neurofibrillary tangles (NFTs). These tangles are a hallmark of Alzheimer’s disease and other tauopathies, including progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).
3. Diseases Involved:
Alpha-synuclein: Predominantly involved in synucleinopathies, such as Parkinson’s disease, multiple system atrophy, and dementia with Lewy bodies.
Tau protein: Mainly associated with tauopathies, including Alzheimer’s disease, frontotemporal dementia (FTD), and other conditions where neurofibrillary tangles play a central role.
4. Aggregation Patterns:
Alpha-synuclein: Aggregates into Lewy bodies, which are intraneuronal inclusions, and are widely distributed in different brain regions in synucleinopathies.
Tau protein: Forms neurofibrillary tangles inside neurons, often seen in the hippocampus and cerebral cortex, particularly in Alzheimer’s disease.
5. Spread in the Brain:
Alpha-synuclein: Propagates through the brain in a prion-like manner, contributing to the progressive spread of pathology, affecting both dopaminergic and non-dopaminergic systems.
Tau protein: Also spreads in a prion-like manner but primarily affects cortical and hippocampal areas involved in memory and cognition.
In summary, alpha-synuclein and tau protein are both implicated in neurodegenerative diseases, but they differ in their normal functions, the types of aggregates they form, and the diseases they are primarily associated with (synucleinopathies for alpha-synuclein and tauopathies for tau protein).
Verifiziert von Dr. Petya Stefanova
