Dexmedetomidine attenuates lipopolysaccharide-induced proinflammatory response in primary microglia.
BACKGROUND
Neuroinflammation mediated by microglia has been implicated in delirium. Suppression of microglial activation may therefore contribute to alleviate delirium. It has been reported that dexmedetomidine (DEX) has a potent anti-inflammatory property. In the present study, we investigated the effects of DEX on the production of proinflammatory mediators in lipopolysaccharide-stimulated microglia.


METHODS
The concentrations of DEX were chosen to correspond to 1, 10, and 100 times of clinically relevant concentration (i.e., 1, 10, and 100ng/mL). The levels of proinflammatory mediators, such as inducible nitric oxide synthase or nitric oxide, prostaglandin E(2), interleukin 1β, and tumor necrosis factor α, were measured.


RESULTS
DEX at 1ng/mL did not affect the production of proinflammatory mediators. DEX at 10 and 100ng/mL significantly inhibited the release of nitric oxide, prostaglandin E(2), interleukin 1β, and tumor necrosis factor α and the expression of inducible nitric oxide synthase messenger RNA.


CONCLUSIONS
These results suggest that DEX is a potent suppressor of lipopolysaccharide-induced inflammation in activated microglia and may be a potential therapeutic agent for the treatment of intensive care unit delirium.
Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, China. pm751101@yahoo.com.cn
Mian
M
Peng
Yan-Lin
YL
Wang
Cheng-Yao
CY
Wang
Chang
C
Chen
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015415:Biomarkers / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020927:Dexmedetomidine / Q000494:pharmacology / Q000627:therapeutic use*; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007249:Inflammation / Q000139:chemically induced* / Q000378:metabolism / Q000517:prevention & control*; D053583:Interleukin-1beta / Q000378:metabolism; D008070:Lipopolysaccharides / Q000009:adverse effects* / Q000494:pharmacology; D017628:Microglia / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D020927:Dexmedetomidine; D052247:Nitric Oxide Synthase Type II; D015232:Dinoprostone