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Objective To evaluate the role of autophagy in dexmedetomidine-induced reduction of lipopolysaccharide ( LPS)-caused inflammatory responses in macrophages of mice. Methods Mouse mac-rophage cell line RAW264. 7 cultured in vitro were seeded in 6-well or 96-well plates and divided into 4 groups ( n=20 each ) when cell confluence reached 60％ using a random number table method: control group (group Con), LPS group, LPS plus dexmedetomidine group (group LPS+DEX), and LPS plus dexmedetomidine plus autophagy inhibitor 3-MA group (group LPS+DEX+3-MA). PBS was added and cells were cultured for 12 h in group Con. LPS at the final concentration of 1000 ng∕ml was added and cells were incubated for 12 h in group LPS. LPS at the final concentration of 1000 ng∕ml was added, and then dexmedetomidine at the final concentration of 1 μmol∕L was immediately added, and cells were incubated for 12 h in group LPS+Dex. In group LPS+Dex+3-MA, 3-MA at the final concentration of 2 mmol∕L was added and cells were incubated for 1 h, LPS at the final concentration of 1000 ng∕ml was added, and then dexmedetomidine at the final concentration of 1 μmol∕L was immediately added, and cells were incubated for 12 h. Cell viability was detected by CCK-8 assay, and the concentrations of nitrous oxide ( NO) , tumor necrosis factor-alpha ( TNF-α) and interleukin-1beta ( IL-1β) in the supernatant were determined by en-zyme-linked immunosorbent assay, and the expression of microtubule-associated protein 1 light chain 3 Ⅰ( LC3 Ⅰ) , LC3Ⅱ, P62 and Bcelin-1 was detected by Western blot. LC3Ⅱ∕LC3Ⅰ ratio was calculated. Results Compared with group Con, the cell viability was significantly decreased, the concentrations of TNF-α, IL-1β and NO and LC3Ⅱ∕LC3Ⅰratio were increased, and the expression of P62 and Beclin1 was up-regulated in group LPS (P<0. 05). Compared with group LPS, the cell viability was significantly in-creased, the concentrations of TNF-α, IL-1βand NO were decreased, LC3Ⅱ∕LC3Ⅰratio was increased, the expression of P62 was down-regulated, and the expression of Beclin1 was up-regulated in group LPS+DEX ( P<0. 05) . Compared with group LPS+Dex, the cell viability was significantly decreased, the con-centrations of TNF-α, IL-1β and NO were increased, LC3Ⅱ∕LC3Ⅰ ratio was decreased, the expression of P62 was up-regulated, and the expression of Beclin1 was down-regulated in group LPS+Dex+3-MA ( P<0. 05) . Conclusion Enhanced autophagy is involved in dexmedetomidine-induced reduction of LPS-caused inflammatory responses in macrophages of mice.
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Objective To evaluate the effect of dexmedetomidine on expression of hypoxia-inducible factor-1α (HIF-1α) during endotoxin-caused apoptosis in macrophages of mice.Methods Mouse macrophage cell line RAW264.7 cultured in vitro were seeded in 6-well or 96-well plates and divided into 4 groups (n=16 each) when cell confluence reached 60％-70％ using a random number table method:control group (group Con),dexmedetomidine group (group Dex),lipopolysaccharide (LPS) group,and LPS plus dexmedetomidine group (group LPS+Dex).Phosphate buffer solution was added in group Con.Dexmedetomidine 1 μmol/L was added in group Dex.LPS 1 μg/ml was added in LPS and LPS+Dex groups.Dexmedetomidine 1 μmol/L was added immediately after adding LPS in group LPS+Dex.Cells were then cultured for 24 h in each group.Cell apoptosis was measured using TUNEL,mitochondrial membrane potential using JC-1,reactive oxygen species (ROS) content by ROS kit,and ATP content by ATP kit.The apoptosis rate was calculated.The expression of HIF-1α,cytochrome C (Cyt-c),caspase-9 and cleaved caspase-3 was detected by Western blot.Results Compared with group Con,the apoptosis rate and ROS content were significantly increased,ATP content and mitochondrial membrane potential were decreased,the expression of HIF-1α,Cyt-c,caspase-9 and cleaved caspase-3 was up-regulated in group LPS (P＜ 0.05),and no significant change was found in the parameters mentioned above in group Dex (P＞0.05).Compared with group LPS,the apoptosis rate and ROS content were significantly decreased,ATP content and mitochondrial membrane potential were increased,the expression of HIF-1α was up-regulated,and the expression of Cyt-c,caspase-9 and cleaved caspase-3 was down-regulated in group LPS + Dex (P＜0.05).Conclusion Dexmedetomidine can reduce endotoxin-caused oxidative stress injury to macrophages,improve mitochondrial function and inhibit mitochondrial apoptosis,and the mechanism may be related to upregulating the expression of HIF-1α in mice.
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Objective To investigate the changes in FUNDC1/microtubule-associated protein 1 light chain 3 Ⅱ (LC3 Ⅱ) signaling pathway during sepsis-induced liver injury in mice.Methods Tbirtytwo clean-grade healthy male C57BL/6 mice,aged 6 weeks,weighing 20-25 g,were divided into sham operation group (n =8) and sepsis group (n =24) using a random number table method.Sepsis was induced by cecal ligation and puncture.Blood samples were obtained at 24 h after operation in sham operation group and at 6,12 and 24 h after establishing the model in sepsis group for determination of concentrations of alanine aminotransferase and aspartate aminotransferase in serum.Mice were then sacrificed,and the right lobe of livers was removed for examination of the pathological changes and for determination of the expression of FUNDC1 and LC3 Ⅱ by Western blot.The mitochondria in the right lobe of livers were isolated to measure the respiratory function,and respiratory control rate was calculated.Results Compared with sham operation group,the concentrations of alanine aminotransferase and aspartate aminotransferase in serum and pathological scores were significantly increased,the respiratory control rate of mitochondria was decreased,the expression of FUNDC1 was down-regulated,and the expression of LC3 Ⅱ was up-regulated at each time point after establishing the model in sepsis group (P＜0.05).Conclusion The mechanism by which sepsis induces liver injury may be related to inhibiting activation of FUNDC1/LC3 Ⅱ signaling pathway in mice.
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Objective To evaluate the effect of hydrogen on blood brain barrier of mice with sepsisassociated encephalopathy (SAE).Methods A total of 100 adult male ICR mice,aged 6-8 weeks,weighing 20-25 g,were divided into 4 groups (n =25 each) using a random number table method:sham operation group (group Sham),sham operation plus hydrogen group (group Sham+H),group SAE and SAE plus hydrogen group (group SAE+ H).Sepsis was induced by cecal ligation and puncture (CLP).Sham+H and SAE+H groups inhaled 2％ hydrogen for 1 h starting from 1 and 6 h after CLP,respectively.At 24 h after CLP,Evans blue (EB) was injected via the caudal vein,and then the mice were sacrificed and brain tissues were removed for measuring the EB and water contents,for examining the pathological changes of hippocampi (with a light microscope) and for detecting the expression of occludin and VE-cadherin (by Western blot).Morris water maze test was performed at days 10-16 after CLP.Results Compared with group Sham,the contents of EB and water in brain tissues were significantly increased,the expression of occludin and VE-cadherin was down-regulated,the escape latency was prolonged,and the number of crossing the original platform was reduced in SAE and SAE+H groups (P＜0.05).Compared with group SAE,the contents of EB and water in brain tissues were significantly decreased,the expression of occludin and VE-cadherin was up-regulated,the escape latency was shortened,the number of crossing the original platform was increased (P＜0.05),and the pathological changes of hippocampi were significantly attenuated in group SAE+H.Conclusion The mechanism by which hydrogen mitigates SAE may be related to reducing the damage to blood brain barrier of mice.