Skip to main content
. Author manuscript; available in PMC: 2021 Sep 1.
Published in final edited form as: Neurochem Int. 2020 May 23;138:104770. doi: 10.1016/j.neuint.2020.104770

Fig. 6. ADX88178 does not exert its anti-inflammatory actions through mGlur4 receptor.

Fig. 6.

Specificity of ADX88178 for mGlu4 receptor was measured. (A) Western immunoblotting using equal amounts of protein from BV2 microglia and mouse cortex revealed that expression of mGluR4 at protein level is very low. (B) At the mRNA level, expression of GRM4 gene in BV2 microglia is significantly lower than in the mouse cortex (****P<0.0001 vs. BV2 microglia). (C-E) qPCR demonstrated a 48% reduction in GRM4 mRNA expression in GRM4 siRNA group compared with scrambled (scrm) control. ADX88178 significantly attenuated LPS-stimulated IL-1β (P<0.0001 LPS vs. LPS+ADX88178 in both scrm control and GRM4 siRNA) and NOS2 (P<0.01, LPS vs. LPS+ADX88178 in scrm control and P<0.05 in GRM4 siRNA) gene expressions. (F) LPS significantly increased TNF-α protein in LPS alone, scrm-treated LPS, and GRM4 siRNA-treated LPS groups (####P<0.0001 vs. control for all three groups) and pretreatment with ADX88178 reduced LPS-induced TNF-α release for all three treatments (****P<0.0001 vs. each respective LPS groups). (G) Group III antagonist, MPPG, did not prevent ADX88178 attenuation of NO levels after LPS stimulation even at the highest concentrations of the antagonist (****P<0.0001, LPS vs. LPS+ADX88178+MPPG 100μM). Statistical analyses: (6C) was analyzed using one-tailed t-test (P=0.073). All remaining data were analyzed using one-way ANOVA for multiple comparisons with post hoc Tukey’s test. ##P<0.01, ####P<0.0001 in comparison with control (Scrm LPS in 6D-E); *P<0.05, ****P<0.0001 in comparison with LPS (GRM4 siRNA LPS in 6D-E).