Optimization of production process of Aeromonas veronii CA07 strain inactivated vaccine / 中国生物制品学杂志

@#Abstract：Objective To optimize the production process of inactivated vaccine of Aeromonas veronii（AV）CA07 strain. Methods The fermentation culture process of AV CA07 strain liquid was determined through the optimization of the culture time（2～16 h），medium（optimized fermentation medium，LB medium and NB medium）and fermentation conditions（in⁃ oculation amount of 1%，5%，10% and 15%；ventilation rate of 2，4，6 and 8 L／min and fermentation time of 6，8，10 and 12 h）. The optimal inactivation process was determined through the comparison of the final concentration of formalde⁃ hyde solution（0. 10%，0. 20%，0. 30% and 0. 40%），inactivation temperature（28 and 37 ℃）and inactivation time（24， 48 and 72 h）. The large⁃scale production process of inactivated vaccine of AV CA07 strain in 500 L fermentor was estab⁃ lished and the prepared vaccines were tested for safety and immunogenicity. Results The optimal inoculation amount of AV CA07 strain was 5%，ventilation rate was 4 L／min and culture time was 10 ~ 12 h. The optimal inactivation condition was adding formaldehyde solution with final concentration of 0. 30% incubating at 37 ℃ for 24 h. The number of viable bacteria in the fermentation broth of AV CA07 strain prepared in 500 L fermentor was more than 8 × 109 CFU／mL. All crucian carps immunized with the inactivated vaccine by abdomen survived. After challenge，the relative immune protection rate was more than 90%. Conclusion AV CA07 strain inactivated vaccine prepared by optimized production process showed good safety and immunogenicity.

Comparative study of three cell morphological analysis methods on in vitro micronucleus assay / 上海预防医学

Objective To investigate the feasibility of genotoxicity assessment for chemicals via flow cytometry (FCM) and high-content screening (HCS) based on high-throughput screening in vitro micronucleus assays. Methods In reference to the methodology of OECD TG487, the typical positive controls, cyclophosphamide (CP) and mitomycin C (MMC), were selected.And no serum MEM medium was treated as negative control.Dose range of CP was 5-20 mg/L and MMC was 0.25-1.0 mg/L.CHL cells were treated with three concentrations of each chemical for 4 h.High-throughput screening in vitro micronucleus assays based on FCM and HCS were established.The results of the frequency of micronuclei were compared to traditional cytokinesis blocking micronucleus assay in each group with or without metabolic activation. Results The frequencies of micronuclei induced by CP and MMC (ascending rank) were separately 1.9%, 7.6%, 10.4% and 5.9%, 11.4%, 16.7%, which were obtained by conventional microscopic scoring.The frequencies of micronuclei induced by CP and MMC (ascending rank) were separately 2.8%, 2.6%, 7.8% and 3.2%, 3.7%, 5.1%, which were obtained by flow cytometry screening.The frequencies of micronuclei induced by CP and MMC (ascending rank) were separately2.8%, 6.2%, 9.1% and 7.9%, 10.1%, 10.2%, which were obtained by high-content screening.Compared with negative controls, the differences of the results were statistically significant(P < 0.05), and there was a dose-response relationship. Conclusion In this study, the results of high-throughput screening assays of FCM and HCS are in accordance to the results of traditional cytokinesis blocking micronucleus assay, indicating that high-throughput screening in vitro micronucleus assays could detect micronucleus formation automatically and improve the efficiency.Therefore, the method could provide data support for using high-throughput screening in vitro micronucleus assays into genotoxicity assessment of chemicals.

Effects of high glucose exposure on permeability of brain microvascular endothelial cells / 上海预防医学

Objective To investigate the permeability of brain microvascular endothelial cells under the condition of high glucose exposure. Methods The bEnd.3 cell line was chosen to detect the value of trans- endothelial electrical resistance (TEER), the activity of alkaline phosphatase (ALP) and γ-glutamyl transferase (γ-GT).Hence, the characteristics of blood-brain barrier in cell model were identified.The permeability of brain microvascular endothelial cells on high glucose exposure was evaluated by cell morphology, cell viability, intracellular lactate dehydrogenase activity and relative expression of ZO-1 and Occludin genes. Results The value of TEER, the activity of ALP and γ-GT increased gradually with increasing incubation time.The observation of cell morphology showed that the number of cells decreased significantly under high glucose exposure, and the adherence was unstable.Cell viability decreased with higher concentration of glucose or longer exposure time under high glucose exposure.The activity of lactate dehydrogenase was also decreased, and there were significant differences among the dose groups (P < 0.05).In addition, the expression levels of tight junction protein ZO-1 and Occludin were further detected.It was found that high glucose exposure inhibited the expression of ZO-1 and Occludin genes in a dose-dependent manner. Conclusion The bEnd.3 cell line has the characteristics of blood-brain barrier.High glucose exposure inhibited the expression of tight junction protein ZO-1 and Occludin. The results might be related to the change of the permeability in brain microvascular endothelial cells

Comparative study of three cell morphological analysis methods on in vitro micronucleus assay / 上海预防医学

Objective To investigate the feasibility of genotoxicity assessment for chemicals via flow cytometry (FCM) and high-content screening (HCS) based on high-throughput screening in vitro micronucleus assays. Methods In reference to the methodology of OECD TG487, the typical positive controls, cyclophosphamide (CP) and mitomycin C (MMC), were selected.And no serum MEM medium was treated as negative control.Dose range of CP was 5-20 mg/L and MMC was 0.25-1.0 mg/L.CHL cells were treated with three concentrations of each chemical for 4 h.High-throughput screening in vitro micronucleus assays based on FCM and HCS were established.The results of the frequency of micronuclei were compared to traditional cytokinesis blocking micronucleus assay in each group with or without metabolic activation. Results The frequencies of micronuclei induced by CP and MMC (ascending rank) were separately 1.9%, 7.6%, 10.4% and 5.9%, 11.4%, 16.7%, which were obtained by conventional microscopic scoring.The frequencies of micronuclei induced by CP and MMC (ascending rank) were separately 2.8%, 2.6%, 7.8% and 3.2%, 3.7%, 5.1%, which were obtained by flow cytometry screening.The frequencies of micronuclei induced by CP and MMC (ascending rank) were separately2.8%, 6.2%, 9.1% and 7.9%, 10.1%, 10.2%, which were obtained by high-content screening.Compared with negative controls, the differences of the results were statistically significant(P < 0.05), and there was a dose-response relationship. Conclusion In this study, the results of high-throughput screening assays of FCM and HCS are in accordance to the results of traditional cytokinesis blocking micronucleus assay, indicating that high-throughput screening in vitro micronucleus assays could detect micronucleus formation automatically and improve the efficiency.Therefore, the method could provide data support for using high-throughput screening in vitro micronucleus assays into genotoxicity assessment of chemicals.

Effects of high glucose exposure on permeability of brain microvascular endothelial cells / 上海预防医学

Objective To investigate the permeability of brain microvascular endothelial cells under the condition of high glucose exposure. Methods The bEnd.3 cell line was chosen to detect the value of trans- endothelial electrical resistance (TEER), the activity of alkaline phosphatase (ALP) and γ-glutamyl transferase (γ-GT).Hence, the characteristics of blood-brain barrier in cell model were identified.The permeability of brain microvascular endothelial cells on high glucose exposure was evaluated by cell morphology, cell viability, intracellular lactate dehydrogenase activity and relative expression of ZO-1 and Occludin genes. Results The value of TEER, the activity of ALP and γ-GT increased gradually with increasing incubation time.The observation of cell morphology showed that the number of cells decreased significantly under high glucose exposure, and the adherence was unstable.Cell viability decreased with higher concentration of glucose or longer exposure time under high glucose exposure.The activity of lactate dehydrogenase was also decreased, and there were significant differences among the dose groups (P < 0.05).In addition, the expression levels of tight junction protein ZO-1 and Occludin were further detected.It was found that high glucose exposure inhibited the expression of ZO-1 and Occludin genes in a dose-dependent manner. Conclusion The bEnd.3 cell line has the characteristics of blood-brain barrier.High glucose exposure inhibited the expression of tight junction protein ZO-1 and Occludin. The results might be related to the change of the permeability in brain microvascular endothelial cells

Effect of passage number on the activity and spontaneous reverse mutation of Ames test strains / 上海预防医学

Objective We explored the stability of the bacteria strains used in the Ames test to provide a basis for determining the appropriate passage number at which the biological characteristics of the strains would not change. Methods The Salmonella typhimurium (TA97a, TA98, TA100 and TA102 strains) were selected as the experimental strains.The original frozen strains and frozen strains with different passage times were used to compare the biological characteristics and the spontaneously reverting colonies. Results The biological characteristics of four kinds of strains, which were histidine deficiency, lipidpolysaccharide barrier defect, ampicillin resistance, UV sensitivity, and tetracycline resistance, did not change at F1-F6 generation when compared with the F0 generation.However, as for the number of spontaneously reverting colonies, a statistically significant difference (P < 0.05) occurred at F3 generation when compared with F0 generation for the TA97a strain, and a significant difference (P < 0.05) occurred at F4 generation for TA100 and TA102 strains. Conclusion Passage number of strains used in Ames test could affect their spontaneous reversion mutation rate.The passage number should be less than 4 for TA98、TA100、TA102 strains, and less than 3 for TA97a in Ames test.

Molecular authentication of Sailonggu and its resource distribution in Qinghai-Tibet Plateau / 中国中药杂志

To provide accurate information on geographic distribution of crude drug Sailonggu in the plateau, we identified zokor species (Eospalax spp.) in Qinghai-Tibet Plateau using molecular methods. Based on the mitochondrial cytochrome B (cytb) gene sequences, we then extracted haplotypes from these sequences and reconstructed phylogenetic trees for the haplotypes using both maximum likelihood (ML) and Bayesian inference (BI) methods. Based on the trees, the species of each sample were determined. Five hundred and three samples from 35 populations were sequenced and their whole cytb sequences (1140 bp) were obtained. From these sequences 150 haplotypes were detected, in which, 126 were Eospalax baileyi, 20 were E. cansus, and 4 were E. smithi of the 35 populations, 28 were E. baileyi type, 5 were E. cansus type, and the remaining 2 were mixed of E. baileyi + E. cansus (DT2) and E. baileyi + E. smithi (ZN3). The results showed that, the regions around the Qinghai lake and near the upper stream of Yellow River started at Guide could be viewed as the producing area of authentic Sailonggu, and also, the cytb gene is a powerful molecular marker to determine the species of zokors as well as for the authentication of geographic distribution of Sailonggu.

Spatial-temporal analysis on the distribution of infected snail at the village level in Anhui province, 2006-2012 / 中华流行病学杂志

Objective The characteristics of spatial-temporal distribution on infected snails were analyzed at the village level in Anhui province,2006-2012.Methods Data on the distribution of infected snails from 2006 to 2012 in Anhui province was collected.Spatial database was established by ArcGIS 9.3.Retrospective spatial-temporal cluster analysis was done by SaTScan 9.1.1 at the village level.Results Eight areas with increased risk and distributed along the upstream to downstream of Yangtze and connecting branch rivers,were found having infected snails,from 2006 through 2012,including one area in 2006,five in 2006-2008,one in 2007-2009 and one in 2009-2011,respectively.Proportion on the number of areas with infected snails decreased from 6.2％ in 2006 to 0.5％ in 2012.Conclusion The spatial-temporal distribution of infected snail was not random but there appeared significant clusters.The trend seemed to be declining in Anhui province,between 2006 and 2012.Areas being detected as smails positive were important for the schistosomiasis control program to be carried out in Anhui province.

Study on sperm damage caused by trichloroethylene in male rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study in vitro sperm damage caused by trichloroethylene in male rats.</p><p><b>METHODS</b>Sperms of Sprague-Dawley (SD) rats were collected 4 hours after being contaminated by trichloroethylene of 0, 2, 4, 6, 8, and 10 mmol/L in vitro. Giemsa staining was performed to observe the morphological changes of sperms, and flow cytometer was used to detect the changes in mitochondrial membrane potential.</p><p><b>RESULTS</b>The sperm motilities in 6, 8, and 10 mmol/L trichloroethylene groups decreased significantly compared with that in control group (P <0.01); the sperm aberration rates in 8 and 10 mmol/L trichloroethylene groups were significantly higher than that in control group (P<0.01). With the increase in exposure dose, the proportion of sperms with reduced mitochondrial membrane potential increased, and there were significant differences in sperm apoptosis rate between the 4, 6, 8, and 10 mmol/L trichloroethylene groups and control group (P<0.01).</p><p><b>CONCLUSION</b>In vitro exposure to trichloroethylene can reduce sperm motility and increase the aberration rate and apoptosis rate of sperms in male SD rats.</p>

Chi-square analysis of the reduction of ATP levels in L-02 hepatocytes by hexavalent chromium

This study explored the reduction of adenosine triphosphate (ATP) levels in L-02 hepatocytes by hexavalent chromium (Cr(VI)) using chi-square analysis. Cells were treated with 2, 4, 8, 16, or 32 μM Cr(VI) for 12, 24, or 36 h. Methyl thiazolyl tetrazolium (MTT) experiments and measurements of intracellular ATP levels were performed by spectrophotometry or bioluminescence assays following Cr(VI) treatment. The chi-square test was used to determine the difference between cell survival rate and ATP levels. For the chi-square analysis, the results of the MTT or ATP experiments were transformed into a relative ratio with respect to the control (%). The relative ATP levels increased at 12 h, decreased at 24 h, and increased slightly again at 36 h following 4, 8, 16, 32 μM Cr(VI) treatment, corresponding to a "V-shaped" curve. Furthermore, the results of the chi-square analysis demonstrated a significant difference of the ATP level in the 32-μM Cr(VI) group (P < 0.05). The results suggest that the chi-square test can be applied to analyze the interference effects of Cr(VI) on ATP levels in L-02 hepatocytes. The decreased ATP levels at 24 h indicated disruption of mitochondrial energy metabolism and the slight increase of ATP levels at 36 h indicated partial recovery of mitochondrial function or activated glycolysis in L-02 hepatocytes.

Evaluation on the effect of comprehensive control strategy of schistosomiasis with emphasis on infection source control in Anhui province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of comprehensive control strategy of schistosomiasis with emphasis on infection source control in Anhui province.</p><p><b>METHODS</b>Forty endemic villages in Guichi district, Chizhou city, Anhui province were selected as national pilot villages in the years from 2006 to 2008, and another 10 provincial pilot villages were respectively selected from 10 highly endemic villages in 7 cities in 2007. The comprehensive infection source control measures, including "replace cattle with machines", "raise livestock in pens", "improve the sanitary toilets", "supply safe water " and so on were carried out among the above pilot villages. At the end of 2008, 13 national pilot villages and 6 provincial pilot villages were selected to investigate the popularity of schistosomiasis, and the effect of the comprehensive control strategy in those villages were compared.</p><p><b>RESULTS</b>After implementing the comprehensive control strategy, the infectious rate of schistosomiasis in national pilot villages decreased from 4.57% (487/10 659) to 1.76% (147/8370), with the reduction rate at 61.49%, whose difference showed statistical significance (χ(2) = 115.16, P < 0.01); and the density of infected snails decreased from 0.0067/0.1 m(2) to 0.0008/0.1 m(2), the infectious rate of snails decreased from 0.28% to 0.04%, whose reduction rates were 88.06% and 85.71% respectively. While as to the provincial pilot villages, the infectious rate of schistosomiasis decreased from 1.27% (54/4254) to 0.21% (14/6592), with the reduction rate at 83.46%, whose difference showed statistical significance (χ(2) = 94.57, P < 0.01); and the density of infected snails decreased from 0.0025/0.1 m(2) to 0.0003/0.1 m(2), the infection rate of snails decreased from 0.13% to 0.05%, whose reduction rates were 88.00% and 61.54% respectively.</p><p><b>CONCLUSION</b>The comprehensive control strategy with emphasis on infection source control implemented in marshland and lake regions can effectively control the transmission of schistosomiasis.</p>

Role of poly (ADP-ribose) polymerase 1 on DNA methylation variation induced by B(a)P in human bronchial epithelial cell / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate DNA methylation variation in human cells induces by B(a)P, and to explore the role of PARP1 during this process.</p><p><b>METHODS</b>The changes of DNA methylation of 16HBE and its PARP1-deficient cells exposed to B(a)P (1.0, 2.0, 5.0, 10.0, 15.0, 30.0 µmol/L) were investigated by immunofluorescence and high performance capillary electrophoresis, and simultaneously, the expression level of PARP 1 and DNMT 1 were monitored dynamically.</p><p><b>RESULTS</b>The percentage of methylated DNA of overall genome (mCpG%) in 16HBE and 16HBE-shPARP1 cells were separately (4.04 ± 0.08)% and (9.69 ± 0.50)%. After being treated by 5-DAC for 72 hours, mCpG% decreased to (3.15 ± 0.14)% and (6.07 ± 0.54)%. After both being exposed to B(a)P for 72 hours, the mCpG% in 16HBE group (ascending rank) were separately (5.10 ± 0.13), (4.25 ± 0.10), (3.91 ± 0.10), (4.23 ± 0.27), (3.70 ± 0.15), (3.08 ± 0.07); while the figures in 16HBE-shPARP1 group (ascending rank) were respectively (10.63 ± 0.60), (13.08 ± 0.68), (9.75 ± 0.55), (7.32 ± 0.67), (6.90 ± 0.49) and (6.27 ± 0.21). The difference of the results was statistically significant (F values were 61.67 and 60.91, P < 0.01). For 16HBE group, expression of PARP 1 and DNMT 1 were 141.0%, 158.0%, 167.0%, 239.0%, 149.0%, 82.9% and 108.0%, 117.0%, 125.0%, 162.0%, 275.0%, 233.0% comparing with the control group, whose difference also has statistical significance (t values were 11.45, 17.32, 32.24, 33.44, 20.21 and 9.87, P < 0.01). For 16HBE-shPARP1 group, expression of PARP 1 and DNMT 1 were 169.0%, 217.0%, 259.0%, 323.0%, 321.0%, 256.0% and 86.0%, 135.0%, 151.0%, 180.0%, 229.0%, 186.0% comparing with the control group, with statistical significance (t values were 9.06, 15.92, 22.68, 26.23, 37.19 and 21.15, P < 0.01). When the dose of B(a)P reached 5.0 µmol/L, the mRNA expression of DNMT 1 in 16HBE group (ascending rank) were 125.0%, 162.0%, 275.0%, 233.0% times of it in control group, with statistical significance (t values were 12.74, 24.92, 55.11, 59.07, P < 0.01); while the dose of B(a)P reached 2.0 µmol/L, the mRNA expression of DNMT 1 in 16HBE-shPARP1 group were 135.0%, 151.0%, 180.0%, 229.0%, 186.0% of the results in control group, and the differences were statistically significant (t values were 23.82, 40.17, 32.69, 74.85, 46.76, P < 0.01).</p><p><b>CONCLUSION</b>The hypomethylation of 16HBE cells induced by B(a)P might be one important molecular phenomenon in its malignant transformation process. It suggests that PARP1 could regulate DNA methylation by inhibiting the enzyme activity of DNMT1, and this effect could be alleviated by PARP1-deficiency.</p>

The effect of DNA methyltransferase 1 low expression on the global genome DNA methylation status of 16HBE cell / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To construct DNA methyltransferase 1 (DNMT1) low expression 16HBE cell line and observe the variation of cell cycle and global genomic DNA methylation.</p><p><b>METHODS</b>The method of Lenti-virus induced RNA interference was applied to introduce four different shRNA fragment into 16HBE cells. Flow cytometry and 5-mC immunofluorescence methods were used to observe the cell cycle and global DNA methylation status of DNMT1 low expression 16HBE cells.</p><p><b>RESULTS</b>The DNMT1 protein relative expression level of 16HBE-shDNMT1-4 cell line was down regulated about 44% (P < 0.05) compared with the control. No obvious differences of cell cycle and global genome DNA methylation status were observed between the 16HBE and 16HBE-shDNMT1.</p><p><b>CONCLUSION</b>The DNMT1 gene low expression cell is successfully constructed, and there are no obvious changes happened on the cell cycle and global genomic DNA methylation.</p>

Genome DNA hypomethylation in the process of crystalline nickel-induced cell malignant transformation / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe the effect of crystalline NiS on genome DNA methylation profile in in vitro cultured cells.</p><p><b>METHODS</b>16HBE Cells were treated with crystalline NiS at 0.25, 0.50, 1.00 and 2.00 µg/cm(2) for 24 h and three times at total. DAC treatment was given at 3 µmol/L for 72 h.5-mC immunofluorescence and SssI methyltransferase assay methods were applied to investigate if the hypomethylation of genome DNA involved.</p><p><b>RESULTS</b>The results of 5-mC immunofluorescence showed that the fluorescence intensity of NiS-treated cells were decreased in some degree, and transformed cells were decreased dramatically. By the SssI methylase assay, an average of (81.9 ± 7.3)% methylated CpG were found in negative control cells. By contrast, (77.9 ± 6.2)%, (75.3 ± 6.8)%, (59.5 ± 4.9)%, (67.4 ± 5.1)% methylated CpG were observed in cells treated with NiS for three times at dosage of 0.25, 0.50, 1.00 and 2.00 µg/cm(2) which were abbreviated as NiS0.25, NiS0.50, NiS1.00, NiS2.00 respectively. The ANOVA analysis results showed that there was a significant difference in the 5 groups above (F = 124.95, P < 0.01). The results of Dunnett-t test showed that the methylated CpG of both group NiS1.00 and NiS2.00 were significantly decreased compared with the negative control group (t values were 7.64, 4.89 respectively, P < 0.01). For methylated CpG, (46.2 ± 4.1)% and (43.6% ± 4.3)% were observed in NiS-transformed cells (NSTC1 and NSTC2) which were dramatically decreased compared with the negative control group (t values were 12.79, 13.56 respectively, P < 0.01).</p><p><b>CONCLUSION</b>Genomic DNA methylation levels were decreased during NiS induced malignant transformation.</p>

Effect of hydroquinone on expression of ubiquitin-ligating enzyme Rad18 in human L-02 hepatic cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of hydroquinone (HQ) on expression of ubiquitin-ligating enzyme Rad18 in human hepatic cells (L-02), and to explore the role and possible mechanism of Rad18 involved in toxicity of HQ to hepatic cells.</p><p><b>METHODS</b>After L-02 hepatic cells were exposed to HQ with various concentrations (0, 5, 10, 20, 40, 80 and 160 micromol/L) for 24 h, cell survival rate was measured by MTT assay; DNA impairment was evaluated by single cell gel electrophoresis (SCGE); The expression levels of Rad18 mRNA and protein were detected by Real-time fluorescent quantitative polymerase chain reaction (QPCR) technique and Western blot method respectively.</p><p><b>RESULTS</b>HQ with concentration from 0 to 80 micromol/L had little effect on survival rate of L-02 (P > 0.05); Whereas the survival rate in the group of 160 micromol/L was significantly lower than in the control with the significant difference (P < 0.01) after treated with HQ for 24 h; The higher dose of HQ presented, the more degrees of olive tail moment (OTM) were produced and a dose-dependent relationship was shown. HQ in a low concentration (0 to approximately 40 micromol/L) could induce increase in the expression of Rad18 mRNA and protein which was in proportion to the increment of HQ concentration; the expression of Rad18 mRNA was enhanced increasingly, while the expression of Rad18 protein unchanged basically once the concentration of HQ exceeded 40 micromol/L; Besides, there was a positive correlation between OTM and the expression level of Rad18 mRNA (r = 0.919, P < 0.01).</p><p><b>CONCLUSION</b>HQ could regulate up the expression of Rad18 in L-02 hepatic cells.</p>

Relationship between polymerase eta expression and DNA damage-tolerance in human hepatic cells by hydroquinone / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of hydroquinone (HQ) on expression of Polymerase eta (Pol eta) and DNA damage in human hepatic cells (L-02), and to explore the role and possible mechanism of Pol eta involved in the process of DNA damage-tolerance.</p><p><b>METHODS</b>After L-02 hepatic cells were exposed to HQ with various concentrations (0, 5, 10, 20, 40, 80 and 160 micromol/L) for 24 h, cell survival rate was detected by MTT assay; DNA impairment was detected by single cell gel electrophoresis (SCGE); Real-time fluorescent quantitative PCR and Western blotting methods were used to measure the expression of Pol eta at the mRNA and protein level in L-02 hepatic cells exposed to HQ with various concentrations (0, 5, 10, 20, 40, 80 and 160 micromol/L).</p><p><b>RESULTS</b>MTT assay showed that HQ with concentrations from 0 to 80 micromol/L had little effect on the survival rate of L-02 (P>0.05); whereas the survival rate of the group of 160 micromol/Lwas significantly higher than that of the control (P<0.01) after being treated with HQ for 24 h; the higher dose of HQ presented, the more degrees of DNA damage were produced. It was found that HQ in a low concentration (1-80 micromol/L) could induce the expression of Pol eta which was in proportion to the increasements of HQ concentration; the expression levels of mRNA and protein were reached to the maximum when treated with 80 micromol/L; the expression of Pol eta decreased (the relative quantity values were 2.32 +/- 0.16 and 1.20 respectively) once the concentration of HQ exceeded 160 micromol/L as compared with the group of 80 micromol/L, but it was higher than that of the control.</p><p><b>CONCLUSION</b>This study suggested that Pol eta might involve in the process of DNA damage-tolerance induced by HQ in the hepatic cells.</p>

Role of cell-surface nucleolin in lipopolysaccharide-stimulated expression and secretion of TNF-alpha and IL-1beta / 中南大学学报(医学版)

OBJECTIVE@#To explore the role of cell-surface nucleolin in lipopolysaccharide (LPS)-stimulated expression and secretion of TNF-alpha and IL-1beta in human THP-1 monocytes.@*METHODS@#Immuno-fluorescence assay and Western blot were used to identify the expression of nucleolin on the surface of THP-1 monocytes. Inactivation of nucleolin was induced by anti-nucleolin monoclonal antibody blockage, and the expression and secretion of TNF-alpha and IL-1beta were observed by using reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immuno-sorbent assay (ELISA)respectively in LPS-mediated human THP-1 monocyte inflammatory model.@*RESULTS@#Immuno-fluorescence showed that nucleolin was localized on the cell surface of THP-1 monocytes as indicated by dotted red fluorescence. Western blot assay indicated that nucleolin existed in the cell membrane fractions. RT-PCR assay showed that the expressions of TNF-alpha and IL-1beta mRNA significantly increased at 2 h and 3 h after the treatment with 1000 microg/L LPS. After 1 h pretreatment with anti-nucleolin antibody, the levels of TNF-alpha and IL-1beta mRNA decreased compared with an anti-nucleolin antibody untreated group and an irrelevant IgG+LPS group (P<0.05). ELISA assay showed that the pretreatment with anti-nucleolin antibody inhibited significantly the secretion of LPS-induced levels of TNF-alpha and IL-1beta after 4, 12 and 24 h treatment with 1000 microg/L LPS.@*CONCLUSION@#Nucleolin expresses on the cell surface of THP-1 monocytes and involves in the LPS-mediated expression and secretion of TNF-alpha and IL-1beta.

Effect of HSP72 on acute injury of neonatal cardiomyocytes induced by oxidative stress / 中南大学学报(医学版)

OBJECTIVE@#To explore the protective effect of HSP72 on the acute injury of cardiomyocyte induced by oxidative stress.@*METHODS@#Cardiomyocytes of neonatal rats treated with heat shock (42 degrees C, 30 min, recovery for 6 h) to induce the expression of HSP72 and HSP72 antisense oligonucleotide was transformed to block the expression of HSP72. 0.5 mmol/L (final concentration) H2O2 was added into the culture medium to mimic oxidative stress, and to induce the acute injury of neonatal cardiomyocytes. The release of LDH and the total protein synthesis were applied to evaluate the injury of cardiomyocyte of neonatal rats.@*RESULTS@#Oxidative stress could significantly increase the release of LDH, and inhibit the total protein synthesis. By inducing the expression of HSPs, heat shock pretreatment significantly reduced the release of LDH and relieved the oxidative stress-mediated inhibition of total protein synthesis. Moreover, HSP7-2 anti-sense oligonucleotide could remarkably block the protective effect of heat shock pretreatment on the cellular injuries induced by H2O2.@*CONCLUSION@#HSP72 plays a most important role in the acute injury of cardiomyocyte mediated by oxidative stress.

Oxidative stress-induced accumulation of heat shock protein 70 within nucleolus / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of oxidative stress on the accumulation of heat shock protein 70 (HSP70) within C2C12 myogenic cells.@*METHODS@#Heat shock response (42 degrees C for 1 h and recovery for 12 h at 37 degrees C) was used to induce the expression of heat shock protein 70. We constructed a recombinant plasmid of HSP70 with enhanced green fluorescent protein (EGFP). After being transfected transiently into C2C12 cells, immunoblotting was used to detect the expression of HSP70 induced by heat shock response and transfection. Immunocytochemistry, fluorescent microscopy and immunoblotting were used to detect the translocation of HSP70.@*RESULTS@#Immunoblotting showed that the overexpression of HSP70 was induced by heat shock response and transient transfenction. HSP70 localized within the cytoplasm of the normal cells, but HSP70 translocated from the cytoplasm to the nucleus and the nucleolus at 1 h after the treatment of oxidative stress (0.5 mmol/L H2O2) by using immunocytochemistry, fluorescent microscopy and immunoblotting for cellular partial proteins.@*CONCLUSION@#Oxidative stress may induce the accumulation of heat shock protein 70 within the nucleolus.