Advances in research on the role of Siglec-1 in diseases / 中国比较医学杂志

Sialoadhesin ( Siglec-1 or CD169 ) is a sialic acid-binding Ig-like lectin expressed selectively on macrophage subsets. In inflammatory response, Siglec-1 can modulate the secretion of MIP-1 alpha / beta, MCP-1, MIP-2 and other cytokines, and promote the occurrence of inflammatory reaction. During viral infection, Siglec-1 can promote the infection and phagocytosis of virus by mediating the binding of pathogens and macrophages. In the regulation of immunity, Siglec-1 can regulate innate immunity and adaptive immunity, by inhibiting the excessive expression of IFN-α and the activation of DC cells. This review mainly focuses on the new advances of research on Siglec-1 in pathogen infections, inflammation and immunoregulation.

Protective effect of tenuigenin on cytotoxicity of primary cultures of cortical neurons induced by amyloid beta-protein 1-40 (Abeta(1-40)) / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of tenuigenin (TEN) on aggregated amyloid beta-protein 1-40 (Abeta(1-40)-induced cytotoxicity of primary cultural cortical neurons in vitro.</p><p><b>METHOD</b>In order to establish neurotoxic model, the primary cultural rat cortical neurons were treated with 25 micromol x L(-1) aggregated Abeta(1-40), which were divided into a model group and 3 different dose groups of TEN (50, 100, 200 micromol x L(-1), respectively), and a normal control group with no treatment of Abeta(1-40) was set up. The morphological changes of the neurons before and after administration of TEN were examined under a phase contrast microscope. Neuronal viabilities were detected by MTT colorimetry. Injuring degrees of the neuronal membrane were assessed by lactate dehydrogenase (LDH) colorimetry.</p><p><b>RESULT</b>As compared with the normal control, treatment of primary cultural neurons with Ap, (25 micromol x L(-1)) for 24 h caused a significant decrease in viabilities and morphological changes of nerve cells, with neurons losing adherent ability or shedding, and the synapse shortening found by microscope. The percentage of apoptotic nerve cells and the LDH leakage were significantly decreased, and the survival rate of neurons was significantly increased in both the TEN high and medium dose groups.</p><p><b>CONCLUSION</b>The aggregated Abeta(1-40) has a definite neurotoxicity for cultural cortical neurons, and TEN can significantly protect the neurons from the cytotoxicity of Abeta(1-40).</p>

Expression of the heat-shock protein 70 family polymorphism in A549 cell line exposed to benzo(a)pyrene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the pattern of polymorphism expression of heat-shock protein 70 (HSP70) family in A549 cell line treated with different concentrations of benzo(a)pyrene (BaP) and its probable biological effect.</p><p><b>METHOD</b>Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was used for the HSP70 expression analysis.</p><p><b>RESULTS</b>2D-PAGE showed that when A549 cells were exposed to different concentrations of BaP (0.1, 1.0, 5.0, 10.0 micromol/L) for 24, 48 h respectively, the HSP72 in A549 gradually declined as BaP concentrations increased [the integral OD (IOD)] for 24 h were: 150.36 +/- 26.03, 98.57 +/- 13.34, 64.92 +/- 15.03, 34.65 +/- 19.10, 32.92 +/- 18.71 respectively, for 48 h: 126.85 +/- 17.41, 106.19 +/- 15.32, 73.64 +/- 21.02, 35.18 +/- 11.95, 16.27 +/- 9.35 respectively), while the IOD of HSP73 did not show any remarkable change (24 h: 102.29 +/- 21.24, 87.71 +/- 18.70, 71.19 +/- 14.08, 71.87 +/- 15.16, 72.78 +/- 17.31 respectively; 48 h: 86.66 +/- 16.86, 75.67 +/- 10.61, 66.83 +/- 12.63, 67.29 +/- 10.26, 91.37 +/- 13.68 respectively).</p><p><b>CONCLUSION</b>BaP can inhibit HSP72 expression and with certain dose-effect relationship, but cannot affect HSP73 expression.</p>

Role of heat shock protein 70 expression in DNA damage induced by benzo(a)pyrene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore heat shock protein 70 (HSP70) expression of A549 cells and its role in DNA damage caused by benzo(a)pyrene (BaP).</p><p><b>METHODS</b>Human adenocarcinoma A549 cells were cultured in vitro, exposed by different concentrations of BaP (0, 1.25, 2.50, 5.00, 10.00 micro mol/L) for 6 hours, or 10 micro mol/L of BaP for different time (0, 4, 8, 12, 16, 24 and 48 h). Then HSP70 expression and DNA damage were detected using Western-blot and single cell gel electrophoresis (SCGE) assay respectively, and the relationship between HSP70 expression and DNA damage was further analyzed.</p><p><b>RESULTS</b>The integral optical densities of HSP70 in A549 cells treated with 1.25, 2.50, 5.00 and 10.00 micro mol/L BaP for 6 h (49.63 +/- 1.30, 45.72 +/- 1.03, 40.53 +/- 0.95, 37.50 +/- 1.20 respectively) were lower than that of the control cells (59.43 +/- 1.17) (P < 0.05). When A549 cells were exposed to 10 micro mol/L BaP for 4, 8, 12, 16 h, the integral optical densities of HSP70 were 33.33 +/- 0.80, 29.23 +/- 0.91, 12.51 +/- 0.96, 9.50 +/- 1.25 respectively, and there was an increasing tendency of the expression of HSP70 for 24 - 48 h (20.06 +/- 1.38, 24.51 +/- 1.39), however, all were different from that in control group (56.59 +/- 0.85) (P < 0.05). DNA damage scores in 10(6) A549 cells treated with 2.50, 5.00 and 10.00 micro mol/L BaP for 6 h (23,718 +/- 2,938, 30,128 +/- 2,937, 44,231 +/- 3,846) were significantly higher than that of the control cell (9,615 +/- 1,923) (P < 0.05). When A549 cells were exposed to 10 micro mol/L BaP for 4, 8, 12, 16, 24, 48 h, DNA damage scores (16,667 +/- 4,003, 38,461 +/- 1,924, 5,615 +/- 3,847, 76,282 +/- 2,937, 7,513 +/- 1,110 and 58,975 +/- 9,487) were also higher than that of control group (P < 0.05). There was a negative correlation between DNA damage and the expression of HSP70 when A549 cells were exposed to different concentrations of BaP.</p><p><b>CONCLUSION</b>HSP70 might enhance intracellular defenses against DNA damage induced by BaP.</p>

Effects of mitogen activated protein kinase signal transduction pathways on heat shock protein 70 gene expression in endothelial cells exposed to benzo(a)pryene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of mitogen activated protein kinase (MAPK) signal transduction pathways on heat shock protein 70 (HSP70) gene expression in endothelial cells exposed to benzo(a)pryene (BaP).</p><p><b>METHODS</b>Porcine aortic endothelial cells were pre-treated or by PD98059 (10 micro mol/L) or SB203580 (20 micro mol/L) for 1 hour, then treated with different concentrations of BaP (0, 0.1, 0.5, 1.0, 5.0 and 10.0 micro mol/L) for 24 hours respectively;Expression levels of three phosphorylated MAPKs [extracellular signal regulated protein kinase (ERK), c-Jun amino-terminal kinase (JNK), and p38] and HSP70 were determined by Western-blot.</p><p><b>RESULTS</b>The three phosphorylated MAPKs expressional levels especially p-ERK1 had different extents of changes with dose-response relationship under BaP exposure. BaP inhibited the expression of HSP70, which significantly decreased in medium and high dose group (>or= 1.0 micro mol/L) but did not decrease in control group (P < 0.05). Although the inhibitor of ERK (PD98059) could partly weaken the inhibited effects of BaP on HSP70 expression, HSP70 expression levels of endothelial cells pre-treated with PD98059 were still significantly lower than that of control cells (P < 0.05).</p><p><b>CONCLUSION</b>ERK1 pathway might play some roles in HSP70 gene expression in endothelial cells exposed to BaP, and other unknown signal pathways might also have some effects on this process.</p>

The expression of cytochrome P450 1A1 of endothelial cells induced by benzo(a)pyrene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effect of benzo(a)pyrene (BaP) on the expression and the activities of cytochrome P450 1A1 (CYP1A1) of porcine aortic endothelial cells.</p><p><b>METHODS</b>Porcine aortic endothelial cells were cultured in vitro, and treated with different concentrations of BaP (0, 0.5, 1.0, 5.0, 10.0 micro mol/L) for 24 hours, CYP1A1 expression was determined by Western blot and immunohistochemistry. At the same time, the ethoxyresorufin-o-deethylase (EROD) activities were measured by spectrofluorometer.</p><p><b>RESULTS</b>By Western blot, the expression of CYP1A1 of control cells was not found, but the expression of CYP1A1 of cells treated with BaP was found; By immunohistochemistry, only part of endothelial cells treated with BaP had positive expression of CYP1A1. The peak activities of EROD induced by BaP was at the concentration of 0.5 - 1.0 micro mol/L.</p><p><b>CONCLUSION</b>BaP could induce part of endothelial cells to synthesize CYP1A1. BaP of 0.5 - 1.0 micro mol/L could induce peak activities of EROD.</p>

Difference in lymphocyte heat shock protein 71 (HSP71) expression in soldiers of armed police forces from different climatic zones / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyze the difference between basal and heat-inducible levels of lymphocyte heat shock protein 71 (HSP71) expression in soldiers from Beijing, Zhengzhou and Guangzhou.</p><p><b>METHODS</b>Flow cytometry and Comet assay were used to detect the level of HSP71 and DNA damage respectively.</p><p><b>RESULTS</b>Comet assay showed that there was no significant DNA damage before and after heat stress at 41 degrees C for 1 h, and also no difference found among the 3 climatic zones(P > 0.05). HSP71 of all soldiers in the 3 zones elevated after stress (P < 0.05). The basal and heat-inducible levels of HSP71 in Beijing soldiers(845.87 +/- 135.60 and 1254. 47 +/- 239.05 mean fluorescence intensity respectively) were higher than those in Guangzhou soldiers(702.73 +/- 184.70 and 861.72 +/- 225.12 mean fluorescence intensity respectively) (P < 0.05).</p><p><b>CONCLUSION</b>The differences of lymphocyte HSP71 expression before and after heat stress among the soldiers from Beijing, Zhengzhou and Guangzhou suggest that basal and heat-inducible levels of lymphocyte HSP71 expression may be considered as a valuable index to evaluate heat tolerance of soldiers in different climatic zones.</p>