Transcriptional profiles for distinct aggregation states of mutant Huntingtin exon 1 protein unmask new Huntington's disease pathways

Date

2017-09

Authors

Moily, Nagaraj S.
Ormsby, Angelique R.
Stojilovic, Aleksandar
Ramdzan, Yasmin M.
Diesch, Jeannine
Hannan, Ross D.
Zajac, Michelle S.
Hannan, Anthony J.
Oshlack, Alicia
Hatters, Danny M.

Journal Title

Journal ISSN

Volume Title

Publisher

Elsevier

Abstract

Huntington's disease is caused by polyglutamine (polyQ)-expansion mutations in the CAG tandem repeat of the Huntingtin gene. The central feature of Huntington's disease pathology is the aggregation of mutant Huntingtin (Htt) protein into micrometer-sized inclusion bodies. Soluble mutant Htt states are most proteotoxic and trigger an enhanced risk of death whereas inclusions confer different changes to cellular health, and may even provide adaptive responses to stress. Yet the molecular mechanisms underpinning these changes remain unclear. Using the flow cytometry method of pulse-shape analysis (PulSA) to sort neuroblastoma (Neuro2a) cells enriched with mutant or wild-type Htt into different aggregation states, we clarified which transcriptional signatures were specifically attributable to cells before versus after inclusion assembly. Dampened CREB signalling was the most striking change overall and invoked specifically by soluble mutant Httex1 states. Toxicity could be rescued by stimulation of CREB signalling. Other biological processes mapped to different changes before and after aggregation included NF-kB signalling, autophagy, SUMOylation, transcription regulation by histone deacetylases and BRD4, NAD+ biosynthesis, ribosome biogenesis and altered HIF-1 signalling. These findings open the path for therapeutic strategies targeting key molecular changes invoked prior to, and subsequently to, Httex1 aggregation.

Description

Keywords

amyloid, huntington's disease, neurodegenerative disease, protein misfolding

Citation

Source

Molecular and cellular neurosciences

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

DOI

10.1016/j.mcn.2017.07.004

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