These authors contributed equally.
Non-motor parkinsonian pathology in aging A53T α-Synuclein mice is associated with progressive synucleinopathy and altered enzymatic function
Article first published online: 20 NOV 2013
© 2013 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of The International Society for Neurochemistry
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Journal of Neurochemistry
Volume 128, Issue 4, pages 536–546, February 2014
How to Cite
J. Neurochem. (2014) 128, 536–546.
- Issue published online: 9 FEB 2014
- Article first published online: 20 NOV 2013
- Accepted manuscript online: 7 OCT 2013 12:37PM EST
- Manuscript Accepted: 1 OCT 2013
- Manuscript Revised: 27 SEP 2013
- Manuscript Received: 30 AUG 2013
- NINDS. Grant Number: NS42094
- Ministry of Education of China. Grant Number: BS2010YY036
- enzymatic dysregulation;
- loss of a-Syn function;
Aging, the main risk factor for Parkinson's disease (PD), is associated with increased α–synuclein levels in substantia nigra pars compacta (SNc). Excess α-synuclein spurs Lewy-like pathology and dysregulates the activity of protein phosphatase 2A (PP2A). PP2A dephosphorylates many neuroproteins, including the catecholamine rate-limiting enzyme, tyrosine hydroxylase (TH). A loss of nigral dopaminergic neurons induces PD movement problems, but before those abnormalities occur, behaviors such as olfactory loss, anxiety, and constipation often manifest. Identifying mouse models with early PD behavioral changes could provide a model in which to test emerging therapeutic compounds. To this end, we evaluated mice expressing A53T mutant human (A53T) α–synuclein for behavior and α–synuclein pathology in olfactory bulb, adrenal gland, and gut. Aging A53T mice exhibited olfactory loss and anxiety that paralleled olfactory and adrenal α-synuclein aggregation. PP2A activity was also diminished in olfactory and adrenal tissues harboring insoluble α-synuclein. Low adrenal PP2A activity co-occurred with TH hyperactivity, making this the first study to link adrenal synucleinopathy to anxiety and catecholamine dysregulation. Aggregated A53T α–synuclein recombinant protein also had impaired stimulatory effects on soluble recombinant PP2A. Collectively, the data identify an excellent model in which to screen compounds for their ability to block the spread of α-synuclein pathology associated with pre-motor stages of PD.
Aging A53T α-synuclein mice develop behaviors common to premotor Parkinson's disease (PD) with synucleinopathy occuring in adrenal gland, olfactory bulb, and intestine. Insoluble aggregated A53T α-synuclein loses PP2A-stimulatory-effects, which normally down regulate dopamine synthesis. This is the first study to link adrenal synucleinopathy to catecholamine dysregulation and anxiety. The mice are an excellent model for testing emerging neuroprotective therapies for PD.