Defining how pathogenic Htt aggregation state alters the transcriptome — ASN Events
  1. Schedule
  2. Session 5: Poster Session A
  3.  Defining how pathogenic Htt aggregation state alters the transcriptome

 Defining how pathogenic Htt aggregation state alters the transcriptome (#178)

Nagaraj S Moily 1 , Yasmin Mohamed Ramdzan 1 , Jeannine Diesch 2 , Ross D Hannan 2 , Kathryn E Holt 1 , Anthony J Hannan 3 , Danny Hatters 1
  1. Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Melbourne, Victoria, Australia
  2. Department of Oncology, Peter MacCallum Cancer Center, Melbourne, Victoria, Australia
  3. Florey Institute of Neuroscience and Mental Health, Melbourne Brain Center, Melbourne, Victoria, Australia

Huntington's disease (HD) is caused by polyglutamine expansion in the huntingtin protein (Htt) that induces inappropriate aggregation, cytotoxicity and subsequent neuronal cell death. The process of aggregation involves the formation of at least three intermediates: monomers of HTT fragment, soluble oligomers and large insoluble aggregates. The resultant abnormal protein-protein interactions and abnormal protein complexes have been postulated to disrupt the normal transcriptional program in neurons; yet it remains unclear precisely how aggregation is involved in these changes. Expression levels of many genes are known to be altered in a HD mouse models and in human HD brain.

We are investigating how different Htt aggregation states alter the transcriptome, which may unmask clues as to how aggregation itself damages a cell or conversely how the cell attempts to mitigate damage caused by the aggregation process. We will answer this question by tracing the specific gene expression changes in relation to changes in aggregation state of mutant Htt in a cell culture model of HD. This will be achieved using flow cytometry methods we have developed (Ramdzan 2012) that enables us to separate and recover cells expressing polyglutamine-expanded Htt enriched with Htt in a monomeric state from cells enriched with Htt as soluble oligomers or large insoluble aggregates. We discuss our use of this method and future goals to analysis recovered cell populations by RNA-Seq.

  1. Ramdzan, Y. M., Polling, S., Chia, C. P., Ng, I. H., Ormsby, A. R., Croft, N. P., Purcell, A. W., Bogoyevitch, M. A., Ng, D. C., Gleeson, P. A., and Hatters, D. M. (2012) Tracking protein aggregation and mislocalization in cells with flow cytometry, Nat. Methods 9, 467-470.