BackgroundInflammatory 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.MethodsA 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-α, IL-1β, 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-κB and AP-1 was measured by luciferase reporter assay and/or electrophoretic mobility shift assay.ResultsWe found that LPS stimulated the expression of TNF-α, IL-1β, IL-6, MCP-1 and iNOS in murine microglia and astrocytes in which MAP kinases, NF-κB and AP-1 were differentially involved. Resveratrol inhibited LPS-induced expression and release of TNF-α, IL-6, MCP-1, and iNOS/NO in both cell types with more potency in microglia, and inhibited LPS-induced expression of IL-1β 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-κB activation in both cell types, but inhibited AP-1 activation only in microglia.ConclusionThese 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.
Little is known about recent variation of temperate glaciers on the Tibetan Plateau, although they are of particular theoretical and practical interests in terms of climate change and water supply. The study of glacier mass balance and terminus variation for six temperate glaciers in the Parlung Zangbo River basin, southeast Tibetan Plateau, shows the facts of the overall negative mass balance and the continued terminus retreat from 2005/2006 to 2007/2008. The mass balances of smaller glaciers were more negative compared to larger glaciers. Referring the trend of glacier mass balance in the Hengduan Mountains, the Himalayas and glacier shrinkage in southeast Tibetan Plateau, the mass loss and recession of temperate glacier in this region are expected if the current climate condition continues.
Southeast Tibetan Plateau, temperate glacier, glacier fluctuations, mass balance
Citation:Yang W, Yao T D, Xu B Q, et al. Characteristics of recent temperate glacier fluctuations in the Parlung Zangbo River basin, southeast Tibetan Plateau.
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