Proteomics of Huntington's disease-affected human embryonic stem cells reveals an evolving pathology involving mitochondrial dysfunction and metabolic disturbances

Leon R. McQuade, Anushree Balachandran, Heather A. Scott, Simer Khaira, Mark S. Baker*, Uli Schmidt

*Corresponding author for this work

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a mutation in the Huntingtin gene, where excessive (≥36) CAG repeats encode for glutamine expansion in the huntingtin protein. Research using mouse models and human pathological material has indicated dysfunctions in a myriad of systems, including mitochondrial and ubiquitin/proteasome complexes, cytoskeletal transport, signaling, and transcriptional regulation. Here, we examined the earliest biochemical and pathways involved in HD pathology. We conducted a proteomics study combined with immunocytochemical analysis of undifferentiated HD-affected and unaffected human embryonic stem cells (hESC). Analysis of 1883 identifications derived from membrane and cytosolic enriched fractions revealed mitochondria as the primary dysfunctional organ in HD-affected pluripotent cells in the absence of significant differences in huntingtin protein. Furthermore, on the basis of analysis of 645 proteins found in neurodifferentiated hESC, we show a shift to transcriptional dysregulation and cytoskeletal abnormalities as the primary pathologies in HD-affected cells differentiating along neural lineages in vitro. We also show this is concomitant with an up-regulation in expression of huntingtin protein in HD-affected cells. This study demonstrates the utility of a model that recapitulates HD pathology and offers insights into disease initiation, etiology, progression, and potential therapeutic intervention.

Original languageEnglish
Pages (from-to)5648-5659
Number of pages12
JournalJournal of Proteome Research
Volume13
Issue number12
DOIs
Publication statusPublished - 5 Dec 2014

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