Effects of trichloroethylene on hepatotoxicity in cytochrome 2E1-silenced hepatocytes / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To prepare cytochrome (CYP)2E1-silenced hepatocytes by lentivirus-mediated RNA interference technology and to investigate the hepatotoxicity of trichloroethylene (TCE) in CYP2E1-silenced hepatocytes.</p><p><b>METHODS</b>Short hairpin RNA fragments were designed and synthesized and were then ligated into the lentiviral vector; single colonies were screened; the plasmid was extracted after PCR and sequence identification and then transferred into L02 hepatocytes; the CYP2E1-silenced hepatocytes were selected; real-time quantitative PCR and Western blot were used to evaluate the interference effects. The obtained CYP2E1-silenced hepatocytes, as well as normal L02 hepatocytes, were treated with TCE (0, 0.25, 0.50, 1.00, 2.00, and 4.00 mmol/L). The cell viability and half maximal inhibitory concentration (IC50) of TCE were measured; the apoptotic rate of cells was measured by flow cytometry; the mRNA expression levels of apoptosis genes and oncogenes were measured by real-time quantitative PCR.</p><p><b>RESULTS</b>The IC50s of TCE for L02 hepatocytes and CYP2E1-silenced hepatocytes were 15.1 mmol/L and 23.6 mmol/L, respectively. The apoptotic rate increased as the dose of TCE rose in the two types of cells; the CYP2E1-silenced hepatocytes hada significantly lower apoptotic rate than L02 hepatocytes when they were exposed to 2.0 and 4.0 mmol/L TCE (P < 0.05 or P < 0.01). The mRNA expression level of bcl-2 (anti-apoptosis gene) in CYP2E1-silenced hepatocytes was 15% ∼ 60% higher than that in L02 hepatocytes (P < 0.01), while the mRNA expression levels of caspase-3 and caspase-9 (apoptosis genes) in CYP2E1-silenced hepatocytes were 30% ∼ 60% lower than those in L02 hepatocytes (P < 0.01). The mRNA expression level of p53 (cancer suppressor gene) in CYP2E1-silenced hepatocytes was 81 - 278% higher than that in L02 hepatocytes (P < 0.01), while the mRNA expression levels of c-fos and k-ras (oncogenes) in CYP2E1-silenced hepatocytes were 20-68% lower than those in L02 hepatocytes (P < 0.01).</p><p><b>CONCLUSION</b>CYP2E1-silenced cells can be successfully prepared by lentivirus-mediated RNA interference technology. Silencing CYP2E1 gene can reduce the hepatotoxicity of TCE and inhibit the expression of some apoptosis genes and oncogenes, suggesting that CYP2E1 gene plays an important role in TCE metabolism and is related to the hepatotoxicity of TCE.</p>

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>

IFN-gamma enzyme-linked immunospot assay versus PPD tuberculin skin test in the diagnosis of tuberculous epididymitis / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the potential application of IFN-gamma enzyme-linked immunospot (ELISPOT) assay in the diagnosis of tuberculous epididymitis (TE) by comparing ELISPOT assay with the traditional purified protein derivative (PPD) tuberculin skin test.</p><p><b>METHODS</b>We examined 13 TE patients using an in-house ELISPOT kit, another 11 TE patients by PPD skin testing, and 57 healthy male volunteers by parallel test with both the methods.</p><p><b>RESULTS</b>Twelve (92.3%) of the 13 TE cases were positive on ELISPOT assay, and 10 (90.9%) of the 11 TE cases positive on PPD skin test, with no statistically significant differences between the two groups (P > 0.05). Among the 57 healthy male volunteers, 8 (14.0%) were positive on ELISPOT, and 28 (49.1%) positive on PPD test, the latter significantly higher than the former (P < 0.001).</p><p><b>CONCLUSION</b>In terms of sensitivity, ELISPOT assay is similar to PPD test in the examination of tuberculous epididymitis. As for specificity, ELISPOT assay seems better than PPD test in differentiating tuberculous epididymitis patients from healthy males.</p>

Screening and identification of differential serum proteins related to dermatitis medicamentosa-like of trichloroethylene / 中华预防医学杂志

<p><b>OBJECTIVE</b>To screen and identify differential serum proteins which might be involved in dermatitis medicamentosa-like of trichloroethylene (DMLT).</p><p><b>METHODS</b>Three groups of sera were collected from population exposed to trichloroethylene (TCE) (group I), patients suffering from DMLT (group II), and the healed cases (group III). After removing albumin and IgG in the three pools of sera, a comparative proteomic analysis was carried out. The images were analyzed using ImageMaster Platinum 2D 5.0 to screen the differentially expressed proteins. The protein spots were then subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry sequencing of tryptic peptides for further identification.</p><p><b>RESULTS</b>The depletion of albumin and IgG greatly increased the number of protein spots to 300 ± 12.Five differential spots were identified, which were complement component C4b, apolipoprotein A-I, apolipoprotein C-III apolipoprotein C-II and transthyretin. Compared with group I, the expression levels of complement component C4b in group III and apolipoprotein C-II in group II were up-regulated (1.352 88-fold, 1.512 14-fold, respectively); compared with group I, the expression levels of apolipoprotein A-I, apolipoprotein C-III and transthyretin in group II were down-regulated (1.601 17-fold, 1.034 49-fold, 1.313 35-fold, respectively).</p><p><b>CONCLUSION</b>The findings of this study show that most of the identified differential proteins are closely related to immunity and liver dysfunction, which provides some evidence on elucidating the mechanisms and screening of biomarkers of TCE intoxication.</p>