الملخص
Objective:To study the effects of fluoride on apoptosis and oxidative stress levels of spinal cord nerve cells in rats.Methods:A total of 54 6-week-old Sprague-Dawley female rats, weighing 150 - 200 g, were selected and fed for 1 week. They were divided into a control group [given deionized water containing 0 mg/L sodium fluoride (NaF)], a low fluoride group (given deionized water containing 50 mg/L NaF), and a high fluoride group (given deionized water containing 100 mg/L NaF) using a random number table method, with 18 rats in each group. All groups received standard feed. After 4, 8, and 12 weeks of fluoride exposure, six rats were selected from each group to observe the occurrence of dental fluorosis, and the motor function of hind limbs in rats was evaluated based on the Basso-Beattie-Bresnahan (BBB) score. Then the rats were anesthetized with 5% chloral hydrate via intraperitoneal injection and euthanized by cardiac puncture. Spinal cord tissue of the rats was collected to detect the activities of oxidative stress factors such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as the contents of malondialdehyde (MDA) and catalase (CAT). After 12 weeks of fluoride exposure, morphologic changes in rat spinal cord neurons were observed using Nissl staining, and apoptosis of spinal cord nerve cells was detected using the TdT mediated dUTP nick end labeling (TUNEL) cell apoptosis detection kit. The Western blotting was used to detect the expression of B-lymphoblastoma-2 (Bcl-2) gene related X protein (Bax), Bcl-2 promoter (Bad), and Bcl-2 protein in rat spinal cord tissue; immunofluorescence staining was used to observe the expression of Bax and Bcl-2 protein in spinal cord neurons.Results:After 12 weeks of fluoride exposure, rats in both the low fluoride and high fluoride groups developed varying degrees of dental fluorosis; the differences of BBB scores of rats in the control, low fluoride, and high fluoride groups were statistically significant ( F = 14.09, P < 0.001). The differences of SOD [(124.04 ± 4.87), (96.66 ± 15.01), (91.12 ± 15.87) U/mg prot] and GSH-Px activitives [(561.92 ± 59.65), (456.83 ± 29.51), (385.07 ± 74.87) U/mg prot], MDA [(9.96 ± 1.50), (16.64 ± 2.05), (20.80 ± 3.37) nmol/mg prot] and CAT contents [(8.97 ± 1.05), (6.39 ± 0.97), (6.42 ± 0.83) nmol/mg prot] among the control, low fluoride, and high fluoride groups were statistically significant ( F = 11.17, 14.19, 30.12, 14.52, P < 0.05). Among them, the SOD, GSH-Px activities, and CAT content in the low fluoride and high fluoride groups were lower than those in the control group, while the MDA content was higher than that in the control group ( P < 0.05). The GSH-Px activity in the high fluoride group was lower than that in the low fluoride group, and MDA content was higher than that in the low fluoride group ( P < 0.05). The intact neuronal structures and clear visible nuclei were seen, and Nissl bodies were uniformly stained in the spinal cord neurons of the control group rats, with more numbers, and no apoptotic cells were observed; the staining of Nissl bodies in the spinal cord neurons of rats was uneven in the low fluoride and high fluoride groups, with fewer numbers, and more apoptotic cells. There were statistically significant differences in the apoptosis rate of spinal cord nerve cells and the expression levels of Bax, Bad, and Bcl-2 protein in the spinal cord tissues of rats in the control, low fluoride, and high fluoride groups ( F = 272.81, 35.53, 17.57, 92.50, P < 0.05). The results of immunofluorescence staining showed that there were statistically significant differences in the fluorescent intensity of Bax and Bcl-2 proteins in the spinal cord neurons of rats in the control, low fluoride, and high fluoride groups ( F = 12.67, 22.14, P < 0.05). Conclusion:Chronic fluorosis induces a decrease in antioxidant enzyme activity, an increase in lipid peroxidation levels, and an increase in neuronal apoptosis in the spinal cord of rats.
الملخص
Aim To observe the effects of rapamycin (Rapa) and starvation-induced autophagy on the morphology of neuronal cells, tau protein aggregation and expression of phosphorylated tau protein, to explore the possible mechanism of cytoprotective effect of these two classical autophagy inducers on phosphorylated tau expressing cells.Methods N2a cells were transfected with GFP-tau plasmid, and equal amount of empty vector was used as control.Then cells were incubated with or without okadaic acid(OA) for 12 h, followed by treatment with autophagy inducers rapamycin(Rapa) and EBSS, autophagy inhibitor Bafilomycin A1(Baf A1) for 6 h.DAB was used to observe tau expression and cell morphology.Confocal microscopy was used to observe the intracellular tau aggregation.TUNEL assay and cleaved caspase-3 level were used to detect cell apoptosis.Immunoblot was used to detect the expression of phosphorylated tau and autophagy-related proteins.Results Our study showed that the N2a cells treated with OA exhibited small cell body, retracted processes and increased tau aggregation, compared with only tau-expressing cells.Rapa and EBSS treatment significantly improved cell morphology, decreased tau aggregation and reduced cell apoptosis.On the contrary, Baf A1 treatment induced aberrant cell shape and increased tau aggregation and cell apoptosis.In addition, Rapa significantly decreased the high molecular weight, phosphorylated tau whereas EBSS especially decreased the low molecular weight phosphorylated tau.Conclusions Rapa and EBSS is alleviate hyperphosphorylated tau-induced cytotoxicity through different mechanism.Rapamycin mainly decreases phosphorylated tau oligomers, while EBSS liable to decrease the soluble phosphorylated tau.
الملخص
Purpose To investigate the expression of RNF2 in breast disease tissues and cell lines,and to analyze the association between expression of RNF2 and clinicopathological characteristics in breast carcinoma.Methods Expression of RNF2 protein and mRNA levels was detected using immunohistochemistry of EnVision two-step and qRT-PCR in breast carcinoma and benign breast disease as well as in cell lines.Results RNF2 expression was sigmificantly higher in breast carcinoma tissue specimens compared with benign breast disease specimens (P ＜0.05).Besides,the expression of RNF2 protein was significantly associated to tumor size,lymph node status and TNM stage (P ＜ 0.05 for both),but was not related to age,histological grade,the expression of ER,PR and HER-2 (P ＞ 0.05 for both).Higher expression of RNF2 mRNA was detected in breast carcinoma cell lines compared with breast epithelial cell lines (P ＜ 0.05).Conclusion RNF2 is overexpressed in breast carcinoma and can be a potential therapeutic target for breast carcinoma.
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Aim To investigate the effect of α1-anti-trypsin Z variant (ATZ)overexpression on cell autoph-agy.Methods HEK 293T cells were transfected with pcDNA3.1 zeo+/ATM or pcDNA3.1 zeo+/ATZ,e-qual amount of empty vector was used as control.Cells were treated with NH4Cl for 4 hours and processed for detecting ATZ,LC3 and p62 by immunoblot.Mean-while ,expression and intracellular localization of ATZ, LC3 in 293 T cells were observed with double labeled immunofluorescence.The mRNA levels of autophagy-related genes were measured by real-time PCR.Immu-nohistochemistry was used to observe the morphology of ATZ-positive cells.Results Compared with the control,higher LC3Ⅱ levels and LC3 puncta were observed in ATZ transfected cells.Meanwhile,the levelsof p62 were decreased in ATZ transfected cells,andreversed by NH4 Cl (25 mmol·L -1 )treatment.Overexpression of ATZ increased the mRNA levels of Atg5and Atg12,but had no obvious influence on Beclin1.ATZoverexpressing cells presented abnormal morphologies.The nuclei became reduced,condensed,and even disappeared in ATZpositive cells.Conclusion ATZ overexpression increases autophagy activity whichmay be related to increasing Atg5 and Atg12 levels.
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Objective To investigate the incidence of diseases in member of rescue teams in the Wenchuan earthquake in Sichuan Province.Method Twenty days afer the Wenchuan earthquake in 2008,5 068 resucing staff of rescue learns as random and cluster sample were investigated and analyzed to find the factors impacting their fitness associated with their characters,diseases,work,and encampment styles.Results Members of rescue teams suffered from the following diseases:insect dermatitis (18.37%),tinea pedis (10.83%),acute upper respiratory infection (10.56%)and solar dermatitis (6.20%).Contrasted by work tasks,staff resucing on the front line had the highest incidence of acute upper-respiratory infection(11.04%) ,logistics workers had the highest incidence of tinea pedis(15.21% ),and more patients of acute gastroenteritis,insect dermatitis,gingivitis emerged from medical personnel group(P<0.05).The encampment sites were devided into three sorts:plain land,hillside and valley.The staff stayed at valley had higher incidence of acute upper respiratory infection (24.90%),insect dermatitis (36.50%) and tinca pedis (20.02%)than those worked at plain land and hillside (P<0.01).The incidence of acute gastroerrteritis(1.26%) ha staff resides hillside is lower than that in valley or plain land (P<0.05).Conclusions In the period of rescue actions in the guake-hit region,the members of rescue teams suffered from famihar diseases such as dermatitis and acute upper-respiratory infection,etc.The incidence of diseases is associated with their work tasks and the topography of cantonment.
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Endoplasmic reticulum(ER) is a locus where proteins are modified,folded and calcium stored.The accumulation of unfolded protein and disorder of calcium ion can lead to ER stress.Early ER stress will induce unfolded protein response(UPR)which may be protective to cells.On the contrary,long-time strong ER stress will induce cell apoptosis,even death.ER stress has been suggested to be involved in some human neurodegenerative diseases.However,the exact contributions of ER stress in the various disease processes are yet unknown.This review mainly summarizes recently reported discoveries concerning ER stress associated with neurodegenerative diseases and highlights current knowledge in this field that may reveal novel insight into disease mechanisms and help to design better therapies for these disorders.