Figure 3: Microglia activation by cell-released α-synuclein is mediated by TLR2. | Nature Communications

Figure 3: Microglia activation by cell-released α-synuclein is mediated by TLR2.

From: Neuron-released oligomeric α-synuclein is an endogenous agonist of TLR2 for paracrine activation of microglia

Figure 3

(a) Expression of cytokines and chemokines upon treatment of αSCM in WT, Tlr2−/−, Tlr3−/−, and Tlr4−/− mouse microglia (n=3). (b) αSCM-induced cytokine production and release in WT and Tlr2−/− microglia (n=3). (c) Effects of TLR2-blocking antibody (T2.5) on induction of IL-1β mRNA. Microglia were pre-incubated with either T2.5 or control IgG for 30 min before addition of αSCM or LZCM (n=3). (d) TLR2 activity was determined in the HEK-Blue-TLR2 reporter cells. Pam3CSK4 (10 ng ml−1) is a known TLR2 agonist and used as a positive control (n=3). (e) Induction of IL-1β mRNA by different amounts of α-synuclein purified from αSCM (n=3). (f) TLR2 activation by the endogenous α-synuclein released from mouse primary cortical neurons. Culture media from WT and α-synuclein null mice primary neurons were treated to the HEK-Blue-TLR2 reporter cells (n=3). (g,h) TLR2-dependent IκB degradation (g) and phosphorylation of p38 MAP kinase (h) in microglia exposed to αSCM (n=3). Relative mRNA expressions (a,c,e) were determined at 2 h post treatment. Cytokine ELISA (b) was performed at 6 h post treatment. IκB degradation (g) and p38 phosphorylation (h) analyses were performed at 15 min post treatment. All data were analysed using unpaired t-test. Error bars represent±s.e.m. *P<0.05; **P<0.01; ***P<0.001. ‘n’ represents the number of independent experiments, and each experiment was performed at least in triplicate.

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