@phdthesis{Kuzkina2020, author = {Kuzkina, Anastasia}, title = {Dermal α-synuclein oligomers and aggregates in Parkinson's disease}, doi = {10.25972/OPUS-20436}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204369}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Lewy bodies and Lewy neurites are neuropathological hallmarks of Parkinson's disease (PD). These depositions in the brain mostly consist of aggregated α-synuclein (α-syn) phosphorylated at Ser129. A number of studies reported detection of phosphorylated α-syn (p-α-syn) in the dermal nerve fibers in Parkinson's disease. The objective of this study was to investigate whether pathological α-syn accumulations detected in the skin represent aggregated protein. A number of methods aimed at detecting α-syn oligomers and aggregates were first tested and optimized on the brain samples in PD and normal control. These methods included proximity ligation assay (PLA), PET-blot, immunohistochemical (IHC) stains with α-syn aggregate (5G4) or oligomer specific (ASyO5) antibodies and a stain against native α-syn (syn211) after proteinase K (PK) digestion. Subsequently, the most specific methods (stains with 5G4, ASyO5 and syn211 after PK digestion) were studied in two separate patient and control cohorts. Anti-p-α-syn stain was performed in parallel. Single sections from at least 2 biopsy sites from 44 patients and 22 controls (cohort 1) as well as serial sections of 4 biopsy sites from 27 patients and 5 controls (cohort 2) were systematically studied for presence of aggregated and oligomeric α-syn. In total, 5G4 positive deposits were found in 24\% (cohort 1) and 37\% (cohort 2), ASyO5 positive lesions in 17,7\% (cohort 1) and 33\% (cohort 2), syn211 positive lesions after PK digestion in 38,7\% (cohort 1) and 48\% (cohort 2) of cases. There was a major overlap among positivity for a particular staining on the patient level and in most cases, the same nerve fiber was found to be positive for all 4 markers in neighboring sections. Among the skin biopsies which contained p-α-syn accumulation, 59\% were also PK resistant, 41\% were 5G4 positive and 45\% were ASyO5 positive. The samples belonging to normal controls did not show any positive signal in either of the newly established stainings or in the anti-p-α-syn staining. Using 3 distinct IHC methods, α-syn oligomers and aggregates were detectable in the majority of p-α-syn positive skin biopsies. This finding supports the hypothesis that α-syn aggregation occurs in the peripheral (i.e. dermal) nerves and can be specifically detected using skin biopsy.}, subject = {Parkinson-Krankheit}, language = {en} }