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The Anti-dyskinetic Effect of the Clinic-ready MGluRpositive Allosteric Modulator AZD8529 in the 6-OHDA-lesioned Rat

Abstract

L-3,4-dihydroxyphenylalanine (L-DOPA) remains the main treatment for motor symptoms of Parkinson's disease (PD). However, chronic use is associated with the development of complications such as L-DOPA-induced dyskinesia. We previously demonstrated that LY-487,379, a highly selective metabotropic glutamate receptor 2 (mGluR2) positive allosteric modulator (PAM), reduces the severity of L-DOPA-induced abnormal involuntary movements (AIMs) in the 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD, without interfering with the anti-parkinsonian action of L-DOPA. Here, we seek to determine the effect of AZD8529, another highly selective mGluR2 PAM, on L-DOPA-induced AIMs in the 6-OHDA-lesioned rat. Unlike LY-487,379, AZD8529 has previously undergone clinical trials and could therefore be repurposed if proven efficacious in pre-clinical studies. We first determined the pharmacokinetic (PK) profile of AZD8529 to administer doses leading to clinically relevant plasma levels in the behavioural studies. Then, dyskinetic 6-OHDAlesioned rats were administered AZD8529 (0.1, 0.3, and 1 mg/kg) or vehicle in combination with L-DOPA followed by assessment of AIMs severity. The cylinder test was then used to evaluate the effect of AZD8529 on the anti-parkinsonian action of L-DOPA. We found that AZD8529 (0.1, 0.3 and 1 mg/kg) in combination with L-DOPA significantly reduced the severity of AIMs duration (P < 0.05), but not amplitude, when compared to L-DOPA/vehicle. AZD8529 administration did not interfere with L-DOPA anti-parkinsonian action. Our results provide evidence that mGluR2 positive allosteric modulation with AZD8529 may be a viable, yet relatively modest, treatment strategy to alleviate L-DOPA-induced.

References
1.
Acri J, Cross A, Skolnick P . From bench to bedside: mGluR2 positive allosteric modulators as medications to treat substance use disorders. Psychopharmacology (Berl). 2016; 234(9-10):1347-1355. DOI: 10.1007/s00213-016-4501-9. View

2.
Ahlskog J, Muenter M . Frequency of levodopa-related dyskinesias and motor fluctuations as estimated from the cumulative literature. Mov Disord. 2001; 16(3):448-58. DOI: 10.1002/mds.1090. View

3.
Anwyl R . Metabotropic glutamate receptors: electrophysiological properties and role in plasticity. Brain Res Brain Res Rev. 1999; 29(1):83-120. DOI: 10.1016/s0165-0173(98)00050-2. View

4.
Bespalov A, Muller R, Relo A, Hudzik T . Drug Tolerance: A Known Unknown in Translational Neuroscience. Trends Pharmacol Sci. 2016; 37(5):364-378. DOI: 10.1016/j.tips.2016.01.008. View

5.
Bezard E, Brotchie J, Gross C . Pathophysiology of levodopa-induced dyskinesia: potential for new therapies. Nat Rev Neurosci. 2001; 2(8):577-88. DOI: 10.1038/35086062. View