Effect of lead exposure on neuroinflammation of hippocampus and cognitive impairment in diabetic rats / 中国职业医学

OBJECTIVE: To explore the effects of lead exposure on inflammatory damage of hippocampus and cognitive impairment in diabetic rats. METHODS: The specific pathogen free(SPF) male healthy Wistar rats were randomly divided into control group and lead-exposed group. The SPF male Goto-Kakisaki Wistar rats rats were randomly divided into diabetes group and diabetes lead-exposed group, with 10 rats in each group. Rats in lead-exposed group and diabetes lead-exposed group were continuously exposed to lead acetate water with a mass fraction of 0.025% for 9 weeks. Rats in control group and diabetes group were given distilled water. The body weight and blood glucose level of rats were measured before lead exposure and at 1, 3, 5, 7 and 9 weeks after exposure. After the exposure, Morris water maze test was used to evaluate the learning and memory ability of rats. The lead levels in whole blood and hippocampal tissues were detected by inductively coupled plasma mass spectrometry, and the expression of mRNA and protein expression of inflammatory factors in hippocampal tissues of rats were detected by real-time fluorescence quantitative polymerase chain reaction and enzyme-linked immunoadsorption, respectively. RESULTS: At the end of lead exposure, the difference of body mass of rats in the diabetes group and the diabetes lead-exposed group was not statistically significant compared with that in the same group before exposure(all P values were >0.05); but the body mass of rats in these two groups was lower than that of the control group and the lead-exposure group(all P values were <0.05). The blood glucose levels of rats were higher in the diabetic group and the diabetes lead-exposed group than that in the control group and the lead-exposed group, respectively(all P values were <0.05). Morris water maze test showed that the escape latency of rats in the 1 st, 2 nd and 3 rd day were longer in diabetes group and the diabetes lead-exposed group than that in the control group and the lead-exposed group(all P values were <0.05). The number of times of crossing platforms were less in the lead-exposed group and the diabetes group than that of the control group(all P values were <0.05). The number of times of crossing platforms was more in the diabetes lead-exposed group than that in the other 3 groups(all P values were <0.05). The levels of lead in blood and hippocampus of rats were higher in the lead-exposed group than those in the control group(all P values were <0.05), and those in the diabetes lead-exposed group were higher than that in the other 3 groups(all P values were <0.05). The relative expression of mRNA of interferon-γ(ifn-γ) and interleukin(il)-6 in hippocampal tissues of rats was higher in the lead-exposed group and the diabetes group than that of the control group(all P values were <0.05). The relative expression of mRNA of tumour necrosis factor-α(tnf-α) and il-1β in the hippocampal tissues of rats was higher in the diabetes group than that of the control group and the lead-exposed group, respectively(all P values were <0.05). The relative expression of mRNA of ifn-γ, tnf-α, il-1β and il-6 in hippocampal tissues of rats was higher in the diabetes lead-exposed group than that of the other 3 groups(all P values were <0.05). The relative protein expression of IFN-γ, TNF-α, IL-4 and IL-6 in hippocampal tissues of rats was higher in lead-exposed group than that of the control group(all P values were <0.05). The relative protein expression of IFN-γ, TNF-α, IL-1β and IL-6 in hippocampal tissues of rats was higher in diabetes group than that of the control group(all P values were <0.05). The relative protein expression of IFN-γ, IL-1β and IL-6 in hippocampal tissues of rats was higher in diabetes group than that of the other 3 groups(all P values were <0.05). CONCLUSION: Diabetes can promote the lead accumulation in the blood and hippocampus of rats. The combined effect of lead exposure and diabetes can up-regulate the expression of pro-inflammatory cytokines in the hippocampal tissues of rats, aggravate the inflammatory response, and have a synergistic effect on the cognitive impairment in rats.

Transfecting pcDNA3-TRAF4-DM-TRAF improves proliferation of human breast cancer cell MDA-MB-231 / 基础医学与临床

Objective_To investigate whether overexpression of TRAF4 in human breast cancer may have impact on its cell proliferation.Methods_This study has two groups, MDA-MB-231 transfected with pcDNA3-TRAF4-DM-TRAF or pcDNA3 .We detected the expression and localization of TRAF4 with immunofluorescence and western blot.We detected the expression of the phosphorylation level of p70S6K and S6 with westernblot.Flow cytometry was used to detecte cell cycle.MTT Assay was used to detected cell reproductive capacity.Results_TRAF4 local-ized in both cytoplasm and nuclei in MDA-MB-231.Nuclear expression of TRAF4 in nuclei was lower than that in cytoplasm (P<0.05).After pcDNA3-TRAF4-DM-TRAF was transfected into the cells, the expression of TRAF4 in nuclei was increased (P<0.05).The phosphorylation level of p70S6K and S6 significantly increaseced (P<0.05,P<0.01).More S phase cells were recorded(P<0.01) by FCM.The cell proliferation was promoted by MTT ( P<0.01) .Conclusions_The expression of TRAF4 in nuclei may play an important role in the cell prolif-eratuion by promoting p70S6K and S6 activation.

Silencing of Fanconi Anemia Complementation Group F Exhibits Potent Chemosensitization of Mitomycin C Activity in Breast Cancer Cells / 한국유방암학회지

PURPOSE: Fanconi anemia complementation group F (FANCF) is a key factor to maintaining the function of Fanconi anaemia/BRCA (FA/BRCA) pathway, a DNA-damage response pathway. However, the functional role of FANCF in breast cancer has not been elucidated. In the present study, we evaluated the chemosensitization effect of FANCF in breast cancer cells. METHODS: We performed specific knockdown of the endogenous FANCF in breast cancer cells by transfecting the cells with an FANCF short hairpin RNA (shRNA) vector. Cell viability was measured with a Cell Counting Kit-8, and DNA damage was assessed with the alkaline comet assay. The apoptosis, cell cycle, and drug accumulation were measured by flow cytometric analysis. Protein expression levels were determined by Western blot analysis, using specific antibodies. RESULTS: The analyses of two breast cancer cell lines (MCF-7 and MDA-MB-435S) demonstrated that the FANCF shRNA could effectively block the FA/BRCA pathway through the inhibition of Fanconi anemia complementation group D2 ubiquitination. Moreover, FANCF silencing potentiated the sensitivity of cells to mitomycin C (MMC), where combined FANCF shRNA/MMC treatment inhibited cell proliferation, induced S-phase arrest, apoptosis, and DNA fragmentation, and reduced the mitochondrial membrane potential, compared with MMC treatment alone. CONCLUSION: Taken together, this study demonstrates that the inhibition of FANCF by its shRNA leads to a synergistic enhancement of MMC cytotoxicity in breast cancer cells. These results suggest that the inhibition of the FA/BRCA pathway is a useful adjunct to cytotoxic chemotherapy for the treatment of breast cancer.

Expression of telomerase genes in cancer development in atypical hyperplasia of the mammary duct / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate telomerase gene expression in precancerous mammary lesion, such as atypical ductal hyperplasia and breast cancer and to study the relationship between expression and malignant transformation.</p><p><b>METHODS</b>Expression of human telomerase genes (hTR) and human reverse transcriptase gene (hTRT) in 76 cases of mammary tissue was evaluated using in situ hybridization and included 50 cases of mammary hyperplasia, 6 of which were benign hyperplasia, 9 were mild atypical hyperplasia, 12 were moderate atypical hyperplasia, 23 were severe atypical hyperplasia and 26 were mammary cancer.</p><p><b>RESULTS</b>The expressions of hTR and hTRT mRNA were much weaker or negative in benign hyperplasia (16.6%, 0), weak to mild moderate in atypical hyperplasia (22.2%, 11.1%, 33.3%, 25.0%), strong in severe atypical hyperplasia (60.9%, 52.1%), and significantly strong in mammary cancer (88.5%, 80.8%). The difference between mild-moderate atypical hyperplasia, invasive ductal carcinoma and severe atypical hyperplasia was significant (P < 0.05) and the difference between severe atypical hyperplasia and intraductal carcinoma was not significant (P > 0.05).</p><p><b>CONCLUSION</b>Telomerase genes (hTR and hTRT) expressions are related to the transformation of atypical hyperplasia. Activated telomerase may play a role in mammary cancer development.</p>

Expression of telomerase genes in mamary atypical ductal hyperplasia / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the relationship of telomerase genes and the malignant transformation of atypical mammary ductal hyperplasia.</p><p><b>METHODS</b>Telomerase genes hTR and hTRT in 50 cases of mammary hyperplasia (the cases included 6 benign hyperplasia, 9 mild atypical hyperplasia, 12 medium atypical hyperplasia, 23 severe atypical hyperplasia) and 26 cases of breast carcinoma were detected by in situ hybridization.</p><p><b>RESULTS</b>The expression of hTR and hTRT mRNA were weak or negative in benign hyperplasia (1/6, 0), weaker in mild-moderate atypical hyperplasia (2/9, 1/9, 4/12, and 3/12), strong in severe atypical hyperplasia (14/23, 60.9% and 12/23, 52.1%), while very strong expression (23/26, 88.5% and 21/25, 80.8%) in carcinoma of the breast. The difference between mild-moderate atypical hyperplasia, invasive ductal carcinoma and severe atypical hyperplasia was significant (P < 0.05) and the difference between severe atypital hyperplasia and intraductal carcinoma was not significant (P > 0.05).</p><p><b>CONCLUSIONS</b>Telmerase genes (hTR, hTRT) expression is closely related to the malignant transformation of atypical hyperplasia. The reactivated telomerase may play a crucial role in the development of breast cancer.</p>