Small interfering RNA-mediated α-enolase knockdown suppresses glycolysis and proliferation of human glioma U251 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of α-enolase (ENO1) in regulating glucose metabolism and cell growth in human glioma cells.</p><p><b>METHODS</b>Glucose uptake and lactate generation were assessed to evaluate the changes in glucose metabolism in human glioma U251 cells with small interfering RNA (siRNA)-mediated ENO1 knockdown. MTT assay and 5-ethynyl-2'-deoxyuridine (EdU) staining were used to examine the cell growth and cell cycle changes following siRNA transfection of the cells.</p><p><b>RESULTS</b>Transfection of U251 cells with siRNA-ENO1 markedly reduced glucose uptake (P=0.023) and lactate generation (P=0.007) in the cells and resulted in significant suppression of cell proliferation (*P<0.05) since the second day following the transfection. Transfection with siRNA-ENO1 also obviously suppressed cell cycle G1/S transition in the cells (P=0.0425). The expressions of HK2 and LDHA, the marker genes for glucose metabolism, were significantly down-regulated in the cells with siRNA-mediated ENO1 knockdown.</p><p><b>CONCLUSION</b>ENO1 as a potential oncogene promotes glioma cell growth by positively modulating glucose metabolism.</p>

Pathological analysis and mRNA expression of apoptosis genes in rat kidney tissue after subacute melamine treatment / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>to investigate pathological changes and mRNA expression of apoptosis genes bcl-2, bax and Caspase-3 in rat kidney tissue after rats are administrated with melamine for 28 days.</p><p><b>METHODS</b>10 male SD rats and 10 female SD rats in each group were administrated with three doses of melamine (low dose, middle dose, high dose) by gavage for 28 days. The animals were divided into three experimental groups and one control group. The doses for male rats were 200, 400, 800 mg/kg, but for female rats they were 150, 300, 600 mg/kg. After melamine treatment the animals were sacrificed and the kidneys were taken out for pathological analysis and for detecting mRNA expression of bcl-2, bax and Caspase-3 with fluorescent quantitative PCR assay.</p><p><b>RESULTS</b>the tubular cylinders were observed in three experimental groups. The positive rates of tubular cylinders in three groups (from low dose to high dose) were 11/20, 13/20, 16/20, respectively. Additionally, melamine induced a significant decrease in mRNA expression of bcl-2 at low dose, middle dose or high dose, bcl-2 expression decreased by 20.58% - 49.51% in three groups treated with melamine. Furthermore, bax mRNA levels increased by 44.66% - 300.96% in groups treated with three doses of melamine, and Caspase-3 mRNA levels increased by 64.76% - 360.75% in groups treated with three doses of melamine.</p><p><b>CONCLUSIONS</b>melamine could induce pathological changes of rat kidneys, and it also induces a significant alteration of apoptosis Bcl-2, Bax and Caspase-3 mRNA expression in rat kidney tissue.</p>

Effect of cadmium chloride on the expression and phosphorylation of mitogen-activated protein kinase in normal rat kidney epithelial cells / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the effect of cadmium chloride on the expression and phosphorylation of mitogen-activated protein kinase (MAPK) in normal rat kidney epithelial (NRK) cells.</p><p><b>METHODS</b>The NRK cells were incubated with cadmium chloride either at respective dose (0, 1, 5, 10, 20, 40 µmol/L) for 24 h or at same dose (10 µmol/L) for respective time (0, 0.5, 1.0, 2.0, 4.0, 8.0 h). Western blotting was applied to test the expression of MAPK in NRK cells (ERK1/2, p38, JNK); and phosphor-specific antibody to detect the phosphorylated MAPK (p-ERK1/2, p-p38, p-JNK).</p><p><b>RESULTS</b>There was no significant difference in the MAPK expression among the groups either treated with different doses or for different time; however, the level of phosphorylated MAPK was comparatively higher than it in control group. There was an obvious expression of p-ERK1/2 at 1.00 ± 0.06 in the group incubated with 10 µmol/L CdCl(2); and the expression in the 20 µmol/L and 40 µmol/L CdCl(2) group was 2.58 ± 0.11, 2.76 ± 0.23 respectively, which was 1.58 and 1.76 times more than it in 10 µmol/L CdCl(2) group. The differences were statistically significant (F = 827.70, P < 0.01). The respective expression of p-p38MAPK in the 20 µmol/L (2.47 ± 0.20)and 40 µmol/L CdCl(2) group (3.73 ± 0.25)was 1.47 and 2.73 times more than it in control group (1.00 ± 0.02), and the differences were also statistically significant (F = 280.06, P < 0.01). There was a dose-effect relationship of the concentration of cadmium in the expression of p-ERK1/2 (r = 0.919, t = 4.69, P = 0.009) and p-p38MAPK (r = 0.945, t = 5.79, P = 0.004). Additionally, phosphorylated MAPK expressed in a time-dependent manner. The expression of p-ERK1/2 was obvious in the group incubated for 1 h (1.26 ± 0.11), and the respective expression in the 4 h group (1.51 ± 0.07) and 8 h group (3.53 ± 0.23) was 1.5 and 3.5 times of it in the control group (1.00 ± 0.02). The differences were statistically significant (F = 427.82, P < 0.001). The expression of p-p38MAPK increased significantly in 1 h group (1.31 ± 0.07); while the respective expression in 4 h group (3.53 ± 0.32) and 8 h group (4.41 ± 0.38) was 3.5 and 4.4 times of it in control group (1.00 ± 0.03). The differences were also statistically significant (F = 280.06, P < 0.001).</p><p><b>CONCLUSION</b>Cadmium chloride could significantly enhance the phosphorylation of MAPK in NRK cells; and it is probably associated with the activation of MAPK.</p>

Study on skin sensitization as well as liver and kidney impairment in guinea pigs treated with trichloroethylene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study skin sensitization as well as liver and kidney impairment in guinea pigs treated with trichloroethylene (TCE).</p><p><b>METHODS</b>Guinea pig maximization test (GPMT) was applied in this study, guinea pigs were divided into 3 groups, namely negative control, positive control and TCE treatment. Animals of 3 groups were administrated with olive oil, 2, 4-dinitrochlorobenzene (DNCB), and TCE, respectively, by intradermal injection. The animal skin was observed and blood was collected after various treatment, the liver function tests were conducted, including detection of activities of ALT, AST, LDH and levels of creatinine, uric acid, and urea with automatic biochemical analyzer.</p><p><b>RESULTS</b>Obvious skin impairment was observed in the groups of positive control and TCE treatment, the skin impairment included erythema and edema, the sensitization rate was 100% in positive control and 83.3% in TCE treatment group. Additionally, the activities of ALT, AST and LDH increased significantly in the groups of positive control and TCE treatment when compared with the negative control.</p><p><b>CONCLUSIONS</b>Trichloroethylene is one of the strong hypersensitizing substances, it could induce skin allergic reaction and liver impairment in guinea pigs.</p>