Early changes in Huntington's disease patient brains involve alterations in cytoskeletal and synaptic elements

Nicholas A. Diprospero, Er Yun Chen, Vinod Charles, Markus Plomann, Jeffrey H. Kordower, Danilo A. Tagle

Research output: Contribution to journalArticlepeer-review

110 Scopus citations

Abstract

Huntington's disease (HD) is caused by a polyglutamine repeat expansion in the N-terminus of the huntingtin protein. Huntingtin is normally present in the cytoplasm where it may interact with structural and synaptic elements. The mechanism of HD pathogenesis remains unknown but studies indicate a toxic gain-of-function possibly through aberrant protein interactions. To investigate whether early degenerative changes in HD involve alterations of cytoskeletal and vesicular components, we examined early cellular changes in the frontal cortex of HD presymptomatic (PS), early pathological grade (grade 1) and late-stage (grade 3 and 4) patients as compared to age-matched controls. Morphologic analysis using silver impregnation revealed a progressive decrease in neuronal fiber density and organization in pyramidal cell layers beginning in presymptomatic HD cases. Immunocytochemical analyses for the cytoskeletal markers α -tubulin, microtubule-associated protein 2, and phosphorylated neurofilament demonstrated a concomitant loss of staining in early grade cases. Immunoblotting for synaptic proteins revealed a reduction in complexin 2, which was marked in some grade 1 HD cases and significantly reduced in all late stage cases. Interestingly, we demonstrate that two synaptic proteins, dynamin and PACSIN 1, which were unchanged by immunoblotting, showed a striking loss by immunocytochemistry beginning in early stage HD tissue suggesting abnormal distribution of these proteins. We propose that mutant huntingtin affects proteins involved in synaptic function and cytoskeletal integrity before symptoms develop which may influence early disease onset and/or progression.

Original languageEnglish (US)
Pages (from-to)517-533
Number of pages17
JournalJournal of Neurocytology
Volume33
Issue number5
DOIs
StatePublished - Sep 2004
Externally publishedYes

ASJC Scopus subject areas

  • Anatomy
  • Neuroscience(all)
  • Histology
  • Cell Biology

Fingerprint

Dive into the research topics of 'Early changes in Huntington's disease patient brains involve alterations in cytoskeletal and synaptic elements'. Together they form a unique fingerprint.

Cite this