Inactivation of Tau oligomer toxicity by G3BP1 and USP10 in Alzheimer's disease

2020 Fiscal Year Research-status Report

• Project/Area Number: 20K16142
• Research Institution: Niigata University
• Principal Investigator: アニシモフ セルゲイ 新潟大学, 医歯学系, 特任助手 (70867572)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: USP10 / Synuclein / Neurodegeneration / Tau

Outline of Annual Research Achievements

Ubiquitinated protein oligomers are neurotoxic and play a major role in several neurodegenerative diseases, including Alzheimer's (AD) and Parkinson's diseases (PD). In AD and PD, tau and α-synuclein (αSyn) are known to be the causative proteins, respectively. Oligomers of ubiquitinated tau and αSyn cause neuronal dysfunction and cell death. It is unclear how the toxicity of tau and αSyn oligomers is regulated in the normal brains and how it is dysregulated in the patient brains. We have found that USP10 promotes the aggregation of αSyn and reduces the toxicity in non-neuronal cells. We are studying how USP10 promotes the aggregation of αSyn and tau and reduces their toxicities. We are also studying whether USP10 decreases the amount of αSyn or tau oligomers in neuronal cells.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

According to our research plan, we are characterizing USP10 activity to the amount, oligomerization and aggregation of α-synuclein and Tau in neuronal cells. We have established the five most common PD associated mutants of α-synuclein and are testing whether USP10 regulates the activity of α-synuclein mutants in a different way than wild-type α-synuclein.

Strategy for Future Research Activity

(1) We will use siRNAs to reduce the amount of USP10, G3BP1, G3BP2 or p62 in neuronal cell lines expressing either α-synuclein or Tau. These cells will be treated with MG-132 for 12 hours to induce oligomers and aggresomes of ub αSyn or Tau. We will evaluate cell death by measuring cell metabolism and and check the amount of αSyn or Tau oligomers by western blot analysis.
(2) By using respective KD cells we will measure the activities of G3BP1, G3BP2 and USP10 to p62-dependent degradation of αSyn or Tau in neuronal cells by western blot analysis.
(3) We will investigate whether USP10, p62, G3BP1 and/or G3BP2 bind to a proteasome subunit by co-immunoprecipitation analysis and examine whether the interaction with a proteasome subunit inhibits a proteasome activity.

Causes of Carryover

Due to the SARS-CoV-2 pandemic, the planned participation in the conference was cancelled, resulting in a carry-over of travel expenses.
For the same reason, the delivery of plastic consumables that we had planned to purchase was delayed, resulting in a carryover of consumables expenses.