Skip to main content
Fig. 3 | Journal of Neuroinflammation

Fig. 3

From: Immunoregulation of microglial polarization: an unrecognized physiological function of α-synuclein

Fig. 3

Monomeric α-Syn regulates microglia towards anti-inflammatory phenotype through ERK, NF-κB, and PPARγ pathways. a α-Syn (100 nM) treatment of primary microglia inhibits p-ERK without obvious effect on total ERK. b The densitometric analysis shows significant decrease of p-ERK under α-Syn treatment. c Inhibition of honokiol inducing ERK phosphorylation is observed under monomeric α-Syn treatment (n = 3). d Quantification of ERK and p-ERK. (Band 1: microglia without stimulation. Band 2, 3: pre-treatment with α-Syn for 30min, then treated with 10 μM and 20 μM honokiol for 90 min, respectively. Band 4, 5: post-treatment with α-Syn for 30min following 10 μM and 20 μM honokiol treatment for 90 min. Band 6: microglia treated with 20 μM honokiol only for 90 min). e Co-IP of BV2 cell-generated protein is performed using α-Syn and ERK antibodies, and the interaction of α-Syn with ERK is detected at 15 min, 30 min, 1 h, and 2 h post α-Syn treatment (n = 3). f Co-localization of α-Syn (green) and ERK (red) in primary microglia after treatment with α-Syn for 15 min (Scale bar = 100 μm, n = 3 replications). g Co-localization of α-Syn (green) and ERK (red) in microglia of mouse brain (scale bar = 10μm, n = 5 mice). h α-Syn (100 nM) treatment prevents NF-κB expression and induces PPARγ. NF-κB activation related proteins IKKα/β and p-IKBα also show a significant decrease in primary microglia after treatment by α-Syn (n = 3 independent experiments). i NF-κB (green) is mainly in the cytoplasm of primary microglia with α-Syn treatment compared with that of LPS treatment, which shows a condensed expression in the nucleus confirmed by confocal microscopy (Scale bar = 10 μm. n = 5). j α-Syn (100nM) treatment inhibits NF-κB translocation into the nucleus of primary microglia with reduction of NF-κB and p-NF-κB in the nucleus (n = 3 independent experiments). k Fluorescence intensity of NF-κB in nuclear in BV2. One-way ANOVA with Newman Keuls multiple comparison test. Bar graphs show mean + s.e.m.*p < 0.05; **p < 0.01; ***p < 0.001

Back to article page