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Background and Purpose: secondary brain injury (secondary brain injury, SBI) increased primary brain trauma mortality, disability rates and affect the prognosis of the key factors. SBI specific mechanism is still not very clear, previous studies mainly related to the following categories: 1, free radical damage; 2, abnormal calcium metabolism of neurons; 3 neurotransmitter doctrine; 4, abnormal blood clotting mechanism; 5, energy metabolism ; 6, cerebral inflammatory damage. The inflammatory response is one of the body is the most common pathophysiological process, the body clear of harmful substances, a means of pathogenic microorganisms and their defense mechanism, but excessive inflammation damage body tissues, but also become an important reason. The waterfall cascading inflammatory response induced damage mechanism is particularly important, leading to brain cell degeneration and necrosis of the main reasons. Inflammatory cascade waterfall formation is often difficult to reverse, so start early intervention is extremely important in inflammation. Interleukin-1 receptor-associated kinase (Interleukin-1 receptor associated kinase, IRAK) the inflammation early signal transduction of the key factors have been discovered in recent years, important to study the role of of IRAK family in SBI development. Microglial cells are the main cells of the brain involved in the inflammatory response, activation can release a variety of inflammatory cytokines, with secondary brain injury and a variety of other diseases of the central nervous system are closely related. At present, research on the relationship of microglia and inflammatory cytokines such as IL-1β, TNF-α and other more; microglia IRAK family existence and its significance, few studies. This study was designed by the observation mouse microglial cells under normal and hypoxic conditions in vitro IRAK-1, IRAK-4, and the expression of inflammatory cytokines TNF-α, and explore the correlation between them, in order to understand the central nervous system ischemic hypoxic conditions, IRAK family's role in microglia-mediated inflammatory response mechanisms and significance. Method: grouping in normoxic conditions and 3% O mouse microglial cell line N9 cells were incubated 1h, 3h, 6h, 12h, 24h, with the semi-quantitative RT-2 under hypoxic conditions PCR, Western Blot IRAK-1, IRAK-4 mRNA and protein expression EILSA method detects TNF-α levels in the culture medium, and were cultured under normoxic cells compared. The laser scanning confocal microscope to observe the expression changes in intracellular IRAK-4. Results: (1) the normal cultured microglia memory in the course of the inflammatory response starts to play an important role TLR/IL-1R signal transduction system key factor IRAK-1 and IRAK-4; (2) microglia set hypoxic environment within, 6h With prolonged hypoxia time, IRAK-1 and IRAK-4 mRNA and protein expression normoxic group gradually increased, hypoxia 3h IRAK-1 and IRAK-4 mRNA and protein expression was significantly higher (P lt; 0.01), 6h reached a peak (P lt; 0.01), hypoxia 12h remained at a high level (P lt; 0.01) 24h nearly normal levels; (3) laser scanning confocal microscope display : IRAK-4 under normoxic mainly expressed in the cytoplasm as hypoxia time IRAK-4 fluorescence was strength gradually strengthen, the fluorescence intensity of the cell membrane around the enhanced strength decreased fluorescence was 24 hours; (4) cell culture medium TNF-α levels with normoxic group in hypoxia 6h or less gradually increased with prolonged hypoxia time 3h increased significantly (P lt; 0.01), peaked at 6h (P lt; 0.01), hypoxia 12h still maintain at a high level (P lt; 0.01), 24h decreased to near normal levels; (5) IRAK-1 and IRAK-4 protein expression under hypoxic conditions change and changes in the culture supernatant TNF-α concentrations showed a significant positive correlation (r = 0.867 and 0.863, respectively, P lt; 0.05). Conclusion: 1. Preliminary experiments verify vitro cultured mouse microglia IRAK family signaling system key factor IRAK-1 and IRAK-4; 2. Cultured mouse microglial cells N9 N9 memory in hypoxia early IRAK-1, IRAK-4 mRNA and protein expression; cultured mouse microglia N9 in the hypoxic certain time IRAK-1, IRAK-4 protein and culture supernatant TNF- The expression of α concentrations were positively correlated.
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