128P London, UK
Pharmacology 2017

 

 

Reversal of β-amyloid induced microglial activation by an agonist of Fpr2

E. S. Wickstead1,2, S. J. Getting1, C. Biggs1, S. McArthur2. 1Science & Technology, University of Westminster, London, United Kingdom, 2Institute of Dentistry, Queen Mary, University of London, London, United Kingdom.

Introduction: Inflammation and oxidative stress are central contributors to Alzheimer’s disease (AD) pathology [1,2], and are well established to associate with increasing levels of amyloid beta (Aβ) [3]. Centrally driven by microglia, they contribute to neuronal death [4]. Dampening or reversing this hyperactive microglial state may protect neurons from chronic oxidative and inflammatory damage and is a potential therapeutic strategy for AD. The G-protein coupled receptor Fpr2 is known to play a key role in peripheral inflammatory resolution [5], and is expressed on microglia [6]; we hypothesised that activation of this receptor with the agonist Quin-C1 (4-Butoxy-N-[1,4-dihydro-2-(4-methoxyphenyl)-4-oxo-3(2H)-quinazolinyl]benzamide) could abrogate Aβ1-42-induced reactive oxygen species (ROS) production and promote an anti-inflammatory phenotype.

Methods: Immortalised murine microglia (BV2 cells) were stimulated with Aβ1-42 (100nM) for 10 min prior to the administration of Quin-C1 (100nM). ROS production was detected every 5 min for 2h with carboxy-H2DCFDA. Both BV2 cells and primary murine microglia were stimulated with Aβ1-42 (100nM) for 1h prior to the addition of Quin-C1 (100nM). The expression of CD38 and CD206 was determined by flow cytometry 24h following Aβ1-42.

Results: Quin-C1 reduced Aβ1-42-induced ROS release (% of Untreated: Quin-C1 = 100.7%, Aβ1-42 = 124.4% and Aβ1-42 + Quin-C1 = 97.5% respectively; n = 4-6, P < 0.05), an effect inhibited by prior treatment with the Fpr2 antagonist WRW4 (10μM; WRW4 + Aβ1-42 + Quin-C1 = 119.8%; n = 3-4, P < 0.05). Aβ1-42 upregulated the expression of CD38 (mean florescence intensity [MFI]: Untreated = 4.7, Quin-C1 = 5.1, Aβ1-42 = 10.6 respectively; n = 3; P < 0.05) whilst Quin-C1 significantly reduced this back to untreated levels (MFI: Aβ1-42 + Quin-C1 = 4.1; n = 3; P < 0.05). Quin-C1 increased the expression of CD206 (MFI: Untreated = 5.2, Quin-C1 = 11.5, Aβ1-42 + Quin-C1 = 8.4; n = 3; P < 0.05), whereas Aβ1-42 alone had no effect (MFI: Aβ1-42 = 3.7; n = 3).

Conclusions: Together, these data suggest that Fpr2 is a therapeutic target for the control of oxidative stress and neuroinflammation in AD, through its pharmacological potential as an anti-oxidative and immunomodulatory drug target.

References:

1. Heneka et al. (2015). Lancet Neurol 14: 388-405.

2. Kamat et al. (2016). Mol Neurobiol 53: 648-661.

3. Rosales-Corral et al. (2015). Oxid Med Cell Longev 2015: 985845.

4. Cunningham C (2013). Glia 61: 71-90.

5. Hughes et al. (2017). Br J Pharmacy 174: 2393-2408.

6. McArthur et al. (2010). J Immunol 185: 6317-28.