Resveratrol differentially modulates inflammatory responses of microglia and astrocytes.
BACKGROUND
Inflammatory responses in the CNS mediated by activated glial cells play an important role in host-defense but are also involved in the development of neurodegenerative diseases. Resveratrol is a natural polyphenolic compound that has cardioprotective, anticancer and anti-inflammatory properties. We investigated the capacity of resveratrol to protect microglia and astrocyte from inflammatory insults and explored mechanisms underlying different inhibitory effects of resveratrol on microglia and astrocytes.


METHODS
A murine microglia cell line (N9), primary microglia, or astrocytes were stimulated by LPS with or without different concentrations of resveratrol. The expression and release of proinflammatory cytokines (TNF-alpha, IL-1beta, IL-6, MCP-1) and iNOS/NO by the cells were measured by PCR/real-time PCR and ELISA, respectively. The phosphorylation of the MAP kinase superfamily was analyzed by western blotting, and activation of NF-kappaB and AP-1 was measured by luciferase reporter assay and/or electrophoretic mobility shift assay.


RESULTS
We found that LPS stimulated the expression of TNF-alpha, IL-1beta, IL-6, MCP-1 and iNOS in murine microglia and astrocytes in which MAP kinases, NF-kappaB and AP-1 were differentially involved. Resveratrol inhibited LPS-induced expression and release of TNF-alpha, IL-6, MCP-1, and iNOS/NO in both cell types with more potency in microglia, and inhibited LPS-induced expression of IL-1beta in microglia but not astrocytes. Resveratrol had no effect on LPS-stimulated phosphorylation of ERK1/2 and p38 in microglia and astrocytes, but slightly inhibited LPS-stimulated phosphorylation of JNK in astrocytes. Resveratrol inhibited LPS-induced NF-kappaB activation in both cell types, but inhibited AP-1 activation only in microglia.


CONCLUSIONS
These results suggest that murine microglia and astrocytes produce proinflammatory cytokines and NO in response to LPS in a similar pattern with some differences in signaling molecules involved, and further suggest that resveratrol exerts anti-inflammatory effects in microglia and astrocytes by inhibiting different proinflammatory cytokines and key signaling molecules.
Lu
Xiaofeng
X
Key laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Ma
Lili
L
Ruan
Lingfei
L
Kong
Yan
Y
Mou
Haiwei
H
Zhang
Zhijie
Z
Wang
Zhijun
Z
Wang
Ji Ming
JM
Le
Yingying
Y
D000704:Analysis of Variance; D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D007249:Inflammation / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D017628:Microglia / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D000077185:Resveratrol; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013267:Stilbenes / Q000494:pharmacology*
D016207:Cytokines; D008070:Lipopolysaccharides; D013267:Stilbenes; D052247:Nitric Oxide Synthase Type II; D020928:Mitogen-Activated Protein Kinases; D000077185:Resveratrol