Protective effects of testosterone on presynaptic terminals against oligomeric β -amyloid peptide in primary culture of hippocampal neurons

Chi Fai Lau, Yuen Shan Ho, Clara Hiu Ling Hung, Suthicha Wuwongse, Chun Hei Poon, Kin Chiu, Xifei Yang, Leung Wing Chu, Raymond Chuen Chung Chang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

20 Citations (Scopus)

Abstract

Increasing lines of evidence support that testosterone may have neuroprotective effects. While observational studies reported an association between higher bioavailable testosterone or brain testosterone levels and reduced risk of Alzheimer's disease (AD), there is limited understanding of the underlying neuroprotective mechanisms. Previous studies demonstrated that testosterone could alleviate neurotoxicity induced by β-amyloid (Aβ), but these findings mainly focused on neuronal apoptosis. Since synaptic dysfunction and degeneration are early events during the pathogenesis of AD, we aim to investigate the effects of testosterone on oligomeric Aβ-induced synaptic changes. Our data suggested that exposure of primary cultured hippocampal neurons to oligomeric Aβ could reduce the length of neurites and decrease the expression of presynaptic proteins including synaptophysin, synaptotagmin, and synapsin-1. Aβ also disrupted synaptic vesicle recycling and protein folding machinery. Testosterone preserved the integrity of neurites and the expression of presynaptic proteins. It also attenuated Aβ-induced impairment of synaptic exocytosis. By using letrozole as an aromatase antagonist, we further demonstrated that the effects of testosterone on exocytosis were unlikely to be mediated through the estrogen receptor pathway. Furthermore, we showed that testosterone could attenuate Aβ-induced reduction of HSP70, which suggests a novel mechanism that links testosterone and its protective function on Aβ-induced synaptic damage. Taken together, our data provide further evidence on the beneficial effects of testosterone, which may be useful for future drug development for AD.
Original languageEnglish
Article number103906
JournalBioMed Research International
Volume2014
DOIs
Publication statusPublished - 1 Jan 2014
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

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