TY - JOUR
T1 - α-Synuclein activates innate immunity but suppresses interferon-γ expression in murine astrocytes
AU - Wang, Jintang
AU - Chen, Zheng
AU - Walston, Jeremy D.
AU - Gao, Peisong
AU - Gao, Maolong
AU - Leng, Sean X.
N1 - Funding Information:
This work was supported by the Irma and Paul Milstein Program for Senior Health, the Milstein Medical Asian American Partnership (MMAAP) Foundation (http://www. mmaapf.org) (Dr. Jintang Wang), and in part by grants R21-AG-043874 and R01AI108907 from National Institutes of Health (Dr. Sean X. Leng).
Funding Information:
This work was supported by the Irma and Paul Milstein Program for Senior Health, the Milstein Medical Asian American Partnership (MMAAP) Foundation (http://www.mmaapf.org) (Dr. Jintang Wang), and in part by grants R21-AG-043874 and R01AI108907 from National Institutes of Health (Dr. Sean X. Leng).
Publisher Copyright:
© 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd
PY - 2018/7
Y1 - 2018/7
N2 - Glial activation and neuroinflammation contribute to pathogenesis of neurodegenerative diseases, linked to neuron loss and dysfunction. α-Synuclein (α-syn), as a metabolite of neuron, can induce microglia activation to trigger innate immune response. However, whether α-syn, as well as its mutants (A53T, A30P, and E46K), induces astrocyte activation and inflammatory response is not fully elucidated. In this study, we used A53T mutant and wild-type α-syns to stimulate primary astrocytes in dose- and time-dependent manners (0.5, 2, 8, and 20 μg/ml for 24 hr or 3, 12, 24, and 48 hr at 2 μg/ml), and evaluated activation of several canonical inflammatory pathway components. The results showed that A53T mutant or wild-type α-syn significantly upregulated mRNA expression of toll-like receptor (TLR)2, TLR3, nuclear factor-κB and interleukin (IL)-1β, displaying a pattern of positive dose–effect correlation or negative time–effect correlation. Such upregulation was confirmed at protein levels of TLR2 (at 20 μg/ml), TLR3 (at most doses), and IL-1β (at 3 hr) by western blotting. Blockage of TLR2 other than TLR4 inhibited TLR3 and IL-1β mRNA expressions. By contrast, interferon (IFN)-γ was significantly downregulated at mRNA, protein, and protein release levels, especially at high concentrations of α-syns or early time-points. These findings indicate that α-syn was a TLRs-mediated immunogenic agent (A53T mutant stronger than wild-type α-syn). The stimulation patterns suggest that persistent release and accumulation of α-syn is required for the maintenance of innate immunity activation, and IFN-γ expression inhibition by α-syn suggests a novel immune molecule interaction mechanism underlying pathogenesis of neurodegenerative diseases.
AB - Glial activation and neuroinflammation contribute to pathogenesis of neurodegenerative diseases, linked to neuron loss and dysfunction. α-Synuclein (α-syn), as a metabolite of neuron, can induce microglia activation to trigger innate immune response. However, whether α-syn, as well as its mutants (A53T, A30P, and E46K), induces astrocyte activation and inflammatory response is not fully elucidated. In this study, we used A53T mutant and wild-type α-syns to stimulate primary astrocytes in dose- and time-dependent manners (0.5, 2, 8, and 20 μg/ml for 24 hr or 3, 12, 24, and 48 hr at 2 μg/ml), and evaluated activation of several canonical inflammatory pathway components. The results showed that A53T mutant or wild-type α-syn significantly upregulated mRNA expression of toll-like receptor (TLR)2, TLR3, nuclear factor-κB and interleukin (IL)-1β, displaying a pattern of positive dose–effect correlation or negative time–effect correlation. Such upregulation was confirmed at protein levels of TLR2 (at 20 μg/ml), TLR3 (at most doses), and IL-1β (at 3 hr) by western blotting. Blockage of TLR2 other than TLR4 inhibited TLR3 and IL-1β mRNA expressions. By contrast, interferon (IFN)-γ was significantly downregulated at mRNA, protein, and protein release levels, especially at high concentrations of α-syns or early time-points. These findings indicate that α-syn was a TLRs-mediated immunogenic agent (A53T mutant stronger than wild-type α-syn). The stimulation patterns suggest that persistent release and accumulation of α-syn is required for the maintenance of innate immunity activation, and IFN-γ expression inhibition by α-syn suggests a novel immune molecule interaction mechanism underlying pathogenesis of neurodegenerative diseases.
KW - astrocytes
KW - cytokines
KW - innate immunity
KW - interferon-γ
KW - toll-like receptors
KW - α-synuclein
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U2 - 10.1111/ejn.13956
DO - 10.1111/ejn.13956
M3 - Article
C2 - 29779267
AN - SCOPUS:85050121675
VL - 48
SP - 1583
EP - 1599
JO - European Journal of Neuroscience
JF - European Journal of Neuroscience
SN - 0953-816X
IS - 1
ER -