Objective To study the important virulence regulation genes of Brucella,and to understand their function.Methods Quantitative RT-PCR was used to quantify their relative transcription profiles under stress conditions and during macrophage cell infection.Results These genes were activated at different levels under these conditions and during cell infection,indicating their roles in pathogenesis at different srage of infection.Conclusion The transcription profiles of these genes have different effects about their functions.

Objective : To used Toll⁃like receptor 4( TLR4) inhibitor ( TAK⁃242) investigate the role of TLR4 in the early stage of acetaminophen (APAP) Ⅳinduced acute liver injury in mice. Methods : Fifty⁃eight male institute of cancer research( ICR) mice were randomly divided into control group ( normal control group , solvent control group , inhibitor control group) and experimental group (APAP 4 ⁃ hour group , APAP + TAK⁃242 4 ⁃ hour group , APAP 12 ⁃ hour group , APAP + TAK⁃242 12 ⁃ hour group) . Mice in the experimental group were given a single dose of APAP (300 mg/kg) and TAK⁃242 (3 mg/kg) were given intraperitoneal injection 3 ⁃ hour before APAP injection. The serum alanine aminotransferase (ALT) level and liver index of mice in each group were compared ; HE staining showed pathological changes of liver tissue;the level of high mobility group box⁃1 (HMGB1) was determined by immunohistochemistry;the levels of TLR4 , HMGB1 and nuclear factor kappa B(NF⁃κB) protein were detected by Western blot;the levels of monocyte chemoattractant protein⁃1( MCP⁃1) , interleukin( IL) Ⅳ1β , tumor necrosis factor⁃α ( TNF⁃α ) and IL⁃6 genes were determined by real⁃time fluorescence quantitative PCR ( RT⁃qPCR) . The content of IL⁃6 in liver tissue was determined by enzyme linked immunosorbent assay (ELISA) . Results : HE staining showed liver tissue of mice obvious swelling and congestion of in APAP group at 4 ⁃hour and typical lobular central necrosis in APAP group at 12 ⁃ hour;the degree of liver necrosis in APAP + TAK⁃242 groups at 4 ⁃ hour and 12⁃ hour was less than that in APAP group at the same time point. Compared with the normal control group , serum ALT level , liver index , TLR4 , HMGB1 , NF⁃κB protein content , MCP⁃1 , IL⁃1β , TNF⁃α , IL⁃6 gene levels and IL⁃6 content in liver tissue of APAP 4 ⁃ hour group increased ; serum ALT level , liver index , HMGB1 protein content and IL⁃6 content in liver tissue increased in APAP 12 ⁃ hour group. Compared with APAP 4 ⁃ hour group , serum ALT level , liver index , TLR4 , HMGB1 , NF⁃κB protein content , MCP⁃1 , IL⁃1β , TNF⁃α , IL⁃6 gene level and IL⁃6 content in liver tissue decreased in APAP + TAK⁃242 4 ⁃ hour group. Compared with APAP 12 ⁃hour group , the levels of TLR4 , HMGB1 protein and MCP⁃1 , IL⁃1β , TNF⁃α genes in APAP + TAK⁃242 12 ⁃ hour group decreased. Conclusion nhibition of TLR4 may inhibit TLR4/HMGB1 pathway to reduce the inflammatory response in the early stage of acetaminophen⁃induced acute liver injury in mice.

Objective To investigate whether Toll-like receptor 4 (TLR4) inhibition affects liver regeneration during acetaminophen (APAP)-induced liver injury in mice, as well as the mechanism of TLR4 involved in liver regeneration. Methods A total of 78 male CD-1 mice were divided into nine groups using a random number table, i.e., three control groups (normal control group, solvent control group, inhibitor control group) with 6 mice in each group and six experimental groups (APAP 24-hour group, TAK-242+APAP 24-hour group, APAP 48-hour group, TAK-242+APAP 48-hour group, APAP 72-hour group, TAK-242+APAP 72-hour group) with 10 mice in each group. The mice in the experimental groups were given a single dose of intraperitoneally injected APAP (300 mg/kg), and TAK-242 was intraperitoneally injected at a dose of 3 mg/kg at 3 hours before APAP administration. Serum and liver tissue samples were collected at different time points. The biochemical method was used to measure the serum level of alanine aminotransferase (ALT); HE staining was used to observe liver pathological changes; RT-PCR, Western blot, and immunohistochemistry were used to measure the expression levels of Cyclin D1, PCNA, Ki-67, STAT3, and p-STAT3. The t -test was used for comparison of normally distributed continuous data between two groups; a one-way analysis of variance was used for comparison between multiple groups, and the least significant difference t -test was used for further comparison between two groups. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups, and the Kruskal-Wallis H test was used for comparison between multiple groups and further comparison between two groups. Results Compared with the normal control group, the APAP 24-hour and 48-hour groups had a significantly higher serum level of ALT (both P < 0.05), and the TAK-242+APAP 24-hour and 48-hour groups had a significantly higher serum level of ALT than the APAP group at the same time point (both P < 0.05). HE staining showed typical central lobular necrosis in the liver of APAP-treated mice, and the TAK-242+APAP 24-hour and 48-hour groups had a significantly larger necrotic area than the APAP group at the same time point (both P < 0.05). RT-PCR, Western blot, and immunohistochemistry showed that the TAK-242+APAP 24-hour, 48-hour, and 72-hour groups had significantly lower mRNA and protein expression levels of Cyclin D1 than the APAP group at the same time point (all P < 0.05); the TAK-242+APAP 24-hour, 48-hour, and 72-hour groups had a significantly lower mRNA expression level of PCNA than the APAP group at the same time point (all P < 0.05), and the TAK-242+APAP 24-hour and 48-hour groups had a significantly lower protein expression level of PCNA than the APAP group at the same time point (all P < 0.05); the TAK-242+APAP 24-hour and 72-hour groups had a significantly lower mRNA expression level of Ki-67 than the APAP group at the same time point (all P < 0.05), and the TAK-242+APAP 24-hour, 48-hour, and 72-hour groups had a significantly lower protein expression level of Ki-67 than the APAP group at the same time point (all P < 0.05). In addition, the TAK-242+APAP 24-hour and 48-hour groups had a significantly lower phosphorylation level of STAT3 than the APAP group at the same time point (both P < 0.05). Conclusion TLR4 may promote liver regeneration by increasing the phosphorylation level of STAT3 during APAP-induced liver injury in mice.

OBJECTIVE: To observe the effect of maltolate aluminum on synaptic plasticity in the hippocampus of rats and to explore the regulatory effect and mechanism of metabotropic glutamate receptor 1(mGluR1). METHODS: Specific pathogen free healthy adult male SD rats were randomly divided into control group, aluminum group, aluminum agonist group and aluminum antagonist group, 8 rats in each group. The rats in the control group received no treatment; the rats in aluminum group were injected with 5 μL 10 mmol/L maltolate aluminum solution into the lateral ventricle; the rats in aluminum agonists and aluminum antagonist group were injected with 3 μL 10 mmol/L maltolate aluminum solution plus 2 μL 0.1 μmol/L mGluR1 agonist or 2 μL 0.2 μmol/L mGluR1 antagonists into the lateral ventricle, respectively.Maltolate aluminum solution was injected every 2 days and continued for 10 days. After maltolate aluminum exposure, the amplitudes of long-term potentiation(LTP) in hippocampal CA1 region of rats were measured, and the relative expression levels of mRNA and protein of mGluR1, N-methyl-D-aspartate receptor(NMDAR1) and protein kinase C(PKC) in hippocampus tissue of rats were detected by real-time fluorescence quantitative polymerase chain reaction and Western blotting. RESULTS: The amplitude of LTP in hippocampal CA1 region in aluminum group and aluminum agonist group was lower than that in the control group and the aluminum antagonist group(P<0.05). Compared with the control group, the relative expression of mGluR1 mRNA and protein in the aluminum group increased, the relative expression of PKC and NMDAR1 mRNA and protein in the aluminum group decreased(P<0.05). Compared with the aluminum group, the relative expression of mGluR1 mRNA and protein in the aluminum agonist group increased, while the NMDAR1 mRNA decreased(P<0.05); the relative expression of mGluR1 mRNA and protein in the aluminum antagonist group decreased, while the NMDAR1 mRNA and protein increased(P<0.05). Compared with the aluminum agonist group, the relative expression of mGluR1 mRNA and protein decreased, while the NMDAR1 mRNA and protein increased in the aluminum antagonist group(P<0.05). The relative expression level of PKC mRNA and protein in aluminum agonist group and aluminum antagonist group was not statistically significant(P>0.05), and there was no statistical significance in these two groups compared with control group and aluminum group(P>0.05). CONCLUSION: Maltolate aluminum exposure can inhibit synaptic plasticity by inhibiting LTP in hippocampus of rats, and the mechanism may be related to the regulation of NMDAR1 expression by mGluR1.

OBJECTIVE: To study the effect of sub-chronic aluminum exposure on synaptic plasticity in the hippocampus of rats and to explore the mechanism of phosphatidylinositol 3 kinase(PI3 K)/protein kinase B(AKT)/rapamycin target protein(mTOR) signaling pathway. METHODS: Specific pathogen free adult healthy male SD rats were randomly divided into control group and low-, medium-and high-dose groups based on body weight, with 10 rats in each group. Rats were treated with maltol aluminum solution at the concentrations of 0, 10, 20 and 40 μmol/kg body weight by intraperitoneal injection, 5 days per week for 3 months. After the exposure, rats were weighed. Morris water maze was used to test the learning and memory ability, and the two-electrode binding technique was used to record the long-term potentiation(LTP) amplitude in the hippocampus CA1 area of rats. The protein expression of PI3 K, AKT and mTOR in rat hippocampus tissues was detected by Western blot. RESULTS: After the exposure, the body weights of rats in the medium-and high-dose groups were lower than that of the control group(P<0.05). The results of the positioning navigation experiment showed that the escape latencies of the rats in the medium-and high-dose groups were shorter than that in the control group during the 2 nd to 4 th days of the experiment(P<0.05). The results of space exploration experiments showed that there was no statistical difference on the target quadrant retention time and the number of crossing the platform among the 4 groups(P>0.05). At 1, 30, and 60 min after high-frequency stimulation, the LTP amplitudes in the hippocampus CA1 area of the aluminum-treated groups were lower than that of the control group at the same time point(P<0.05), and the LTP amplitudes of hippocampus CA1 area of rats decreased with the increase of maltol aluminum exposure dose(P<0.01). The relative expression of PI3 K, AKT and mTOR protein in the hippocampus tissues of the aluminum-treated groups was lower than that of the control group(P<0.05), and the relative expression of the above three proteins decreased with the increase of the maltol aluminum exposure dose(P <0.01). CONCLUSION: Sub-chronic aluminum exposure could lead to dose-dependent inhibition of hippocampus synaptic plasticity in rats, thereby impairing the spatial learning ability of rats. This process may be related to inhibition of PI3 K/AKT/mTOR signaling pathway by aluminum.