Паркинсон ауруындағы нейрондардағы сфералық инклюзиялар

Spherical inclusion commonly found in damaged neurons

Lewy bodies are the inclusion bodies – abnormal aggregations of protein – that develop inside nerve cells affected by Parkinson's disease (PD), the Lewy body dementias (Parkinson's disease dementia and dementia with Lewy bodies (DLB)), and some other disorders. They are also seen in cases of multiple system atrophy, particularly the parkinsonian variant (MSA P). Lewy bodies appear as spherical masses in the cytoplasm that displace other cell components. For instance, some Lewy bodies tend to displace the nucleus to one side of the cell. There are two main kinds of Lewy bodies: classical and cortical. Lewy bodies may be found in the midbrain (within the substantia nigra) or within the cortex. A classical Lewy body is an eosinophilic cytoplasmic inclusion consisting of a dense core surrounded by a halo of 10 nm wide radiating fibrils, the primary structural component of which is alpha synuclein.

In 1910, Fritz Heinrich Lewy was studying in Berlin for his doctorate. He was the first doctor to notice some unusual proteins in the brain, comparing them to earlier findings by Gonzalo Rodríguez Lafora. Konstantin Nikolaevich Trétiakoff found them in 1919 in the substantia nigra of PD brains, called them corps de Lewy and is credited with the eponym. Eliasz Engelhardt, who is in the neurology department at Federal University of Rio de Janeiro, argued in 2017 that Lafora should be credited with the eponym, because he named them six years before Trétiakoff.

A Lewy body is composed of the protein alpha synuclein associated with other proteins, such as ubiquitin, neurofilament protein, and alpha B crystallin. Tau proteins may also be present, and Lewy bodies may occasionally be surrounded by neurofibrillary tangles. Lewy bodies and neurofibrillary tangles can occasionally exist in the same neuron, particularly in the amygdala. Alpha synuclein modulates DNA repair processes, including repair of DNA double strand breaks (DSBs) by the process of non homologous end joining The repair function of alpha synuclein appears to be greatly reduced in Lewy body bearing neurons, and this reduction may trigger cell death. Mutations are the reason behind their damaged repair function. One mutation in particular, in the gene encoding for presynaptic alpha synuclein, was found to have been passed down from family members with PD. When misfolded proteins aggregate, or clump together, many diseases are more likely to develop, including those that are associated with Lewy bodies. Aggregation is believed to occur when there is a high amount of misfolded proteins in the ubiquitin proteasome pathway, which are then brought to a resulting aggresome so they can be organized into one place. This makes it an important protein family in regards to Lewy body associated diseases, and there are at least 7 forms of it that have been clearly identified in mammals. as well as in patients with other tauopathies.

Lewy neurites are abnormal neurites in diseased neurons, containing granular material and abnormal α synuclein filaments similar to those found in Lewy bodies. Like Lewy bodies, Lewy neurites are a feature of α synucleinopathies such as dementia with Lewy bodies, Parkinson's disease, and multiple system atrophy. They are also found in the CA2 3 region of the hippocampus in Alzheimer's disease.