Abstract Details

Title Ubiquilin2 Mutations in Parkinson's Disease Extend the Spectrum of Ubiquilinopathies

Topic Movement Disorders

Presentation(s) IN2 - (-)

Poster/Presentation
Number 004

Objective

Background Ubiquilin2 belongs to the ubiquitin-like protein family which delivers uiquitinated proteins to the proteasome system (UPS) and autophagosome for protein and organelle degradation. Mutant ubiquilin2 recruits protein aggregates and become a pathological hallmark in several neurodegenerative diseases, such as ALS and ALS-dementia. To identify whether the ubiquilin2-positive inclusions is a common phenomenon in neurodegenerative diseases, Parkinson disease, the second most common in the world was chosen to screen for ubiquilin2 mutations.

Design/Methods Genomic DNA was PCR-amplified and sequenced by a CEQ-8000 system (Beckman Coulter). Immunohistochemistry and immunofluorescent stain were performed by standard protocol. Expression vectors of ubiquilin2-WT and mutations were co-expressed into Neuro-2A and SH-SY5C cell lines with either UbG76V-GFP or LC3-GFP reporters and analyzed by a BD LSRFortessa flow cytometer and BD FACSDiva softwarse.

Results We sequenced 400 PD patients and found two mutations (M1, M2) which were absent in controls. Ubiquilin2 was found in Lewy bodies and Lewy neuritis in the substantia nigra in M1. In Neuro-2A cells, the cleavage of GFP in UPS reporter of the PD-related mutations showed no difference, and the autophagosome marker (LC3-GFP) showed a tendency of impairment in M2. After tested SH-SY5C cells which have some dopaminergic charactersistics, LC3 impairment showed intensified. Both mutations showed cell-type-related autophagosome impairment, p <0.0004.

Conclusions The novel PD-related mutations locate in different functional domains other than the reported PXX region mutations. The new mutations did not cause any disruption in proteasome system in vitro, while they exhibited cell specific autophagy impairment. The patient with M1 showed ubiquilin2-positive inclusions in dopaminergic cells. Our results demonstrate that ubiquilinopathies are etiologic and/or pathologic factors underlying a wide spectrum of neurodegenerative diseases.

Authors/Disclosures
Yong Shi, PhD (Northwestern University) PRESENTER	No disclosure on file
	No disclosure on file
Faisal Fecto, MD, PhD (Advocate Medical Group)	The institution of Dr. Fecto has received research support from NINDS.
	No disclosure on file
Juanzhi Fang (EMD Serono)	No disclosure on file
	No disclosure on file
Han-Xiang Deng, MD	Dr. Deng has nothing to disclose.
	No disclosure on file
Alexander H. Rajput, MD, FAAN (Royal Univ Hosp/division of Neuro)	Dr. Rajput has received personal compensation in the range of $500-$4,999 for serving as a Peer reviewer with CQDM.
Joseph Jankovic, MD, FAAN (Baylor College of Medicine)	Dr. Jankovic has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Revance. Dr. Jankovic has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Revance, Allergan. The institution of Dr. Jankovic has received research support from Baylor College of Medicine. Dr. Jankovic has received research support from Abbvie. The institution of Dr. Jankovic has received research support from Abbvie.
Ali H. Rajput, MD, FAAN (Royal Univ Hospital/Dept of Neuro)	No disclosure on file
Teepu Siddique, MD, FAAN	No disclosure on file

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