[Abstract Title]. - Society for Neuroscience

Poster
247. Parkinson's Disease Interventions: Animal and Clinical Models
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 247.16/S11
Topic: C.02.d. Therapies
Title: Effect of T-817MA on 1-Methyl-4-phenylpyridinium (MPP+) and Amyloid β (Aβ)
induced dying-back degeneration in primary culture of rat cortical neurons
Authors: *K. HIRATA 1,2 , M. SUGIMORI 1 , R. LLINAS 1 ;
1 Dept Physiol Neurosci, New York Univ. Med. Cntr, New York, NY; 2 Res. Labs., Toyama
Chem. Co., Ltd., Toyama, Japan
Abstract: Fast axonal transport (FAT) defects are present in a variety of neurodegenerative
diseases, probably associated with a lost of synaptic function characteristic of a “dying-back”
neuropathy. We previously demonstrated that 1-Methyl-4-phenylpyridinium (MPP + ) and
amyloid-β peptide 1-42 (Aβ) impaired mitochondria FAT in primary culture of rat cortex neurons.
Here we demonstrate that bath application of either MPP + or Aβ induce dying back degeneration
in rat cortical primary culture. We further studied whether such “dying back” event could be
prevented by T-817MA (1-{3-[2-(1-Benzothiophen-5-yl)ethoxy]propyl}azetidin-3-ol maleate), a
pharmacological agent developed specifically for neurodegenerative disorders such as
Alzheimer‟s disease. Primary cortical cell cultures were prepared from E17 Sprague-Dauley rat.
At 7-10 days of culture, cells were exposed to 30 κM MPP + or 10 κM Aβ, both of which can
cause mitochondria FAT impairment. Dying back phenomena was determined optically with a
Olympus IX-71 microscope and MagnaFire digital CCD camera, using three criteria: (1)
Morphological observation under bright field microscopy. (2) Fluorescence imaging (FITC) with
conjugated Annexin V, which binds specifically to phosphatidylserine translocated to the outer
plasma membrane during apoptosis. (3) Imaging active synaptic terminals based on FM1-43
endocytosis . MPP + treatment at 30κM for 24 hr induced mitochondria FAT impairment with no
morphological changes. On the other hand, longer treatment (more than 3 days) of MPP + induced
membrane beading and shrinking in distant neurites. Annexin V-FITC binding was identified on
neurite beads and blebs in MPP + treated cultures with little binding on neuronal cell somata . In
these terminals synaptic activity, judged by the endocytosis of FM1-43, was reduced. These
results indicate that MPP + can induce dying back phenomena at the same concentration that
induced mitochondria FAT impairment. Aβ, which has been known to induce dying back
degeneration, also induced similar dying back changes as seen in MPP + treatment in our culture.
Simultaneous application of 1 κM of T-817MA with MPP + or Aβ prevented the dying back
phenomena induced by the neurotoxins. This result indicates that T-817MA can rescue dying
back degeneration in the neurons and might have benefit for neurodegenerative disease