Role of neuronal RNA granules in the etiology of neuropsychiatric disorders

2020 Fiscal Year Research-status Report

• Project/Area Number: 19K16273
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Krzyzanowski Marek 国立研究開発法人理化学研究所, 脳神経科学研究センター, 基礎科学特別研究員 (10837181)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: translation / RNA granules / psychiatric disorders / memory

Outline of Annual Research Achievements

Previously, I compared the composition of brain RNA granules from wild-type and neuropsychiatric disorder model mice by quantitative protein mass-spectrometry (MS), using isobaric tags. Recently, I supplemented those experiments with another MS approach - label free quantification (LFQ). Together, these datasets suggest many proteins mildly change their abundance in the brain RNA granules of disease model mice.
Since impaired local translation may cause defects in learning, I investigated how RNA granules change in cultured neurons during cLTP (chemical long-term potentiation) induction. Preliminary MS data show a few proteins changing significantly upon stimulation, however additional data is needed to have a deeper insight into the regulation of RNA granules in response to stimulation.

Current Status of Research Progress

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

Reason

During the last fiscal year I focused on the long-term culture of cortical neurons at high-density and evaluated their responsiveness to the cLTP-inducing protocol. I applied biochemical method of RNA granule purification that I developed previously for the brain material. I obtained the reference RNA granule proteome data from untreated cultured neurons. Additionally I expanded the available data on the RNA granule proteome in neuropsychiatric disorder model mice.

Strategy for Future Research Activity

I will continue to gather the data on the changes occurring to RNA granules depending on neuronal activity (cLTP), including at various time points post-stimulation. To gain insight into the changes occurring locally in the cell periphery (axon and dendrites) I will culture neurons on permeable support membranes to isolate RNA granules separately from cell body and neurites. Next, the behaviour of proteins that are differentially regulated during cLTP will be checked by fluorescent microscopy.
Using western blotting I will validate the abundance changes of the selected RNA granule proteins deregulated in neuropsychiatric disorder model mouse brain, that were identified with the two different MS approaches.