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Background In the process of radiotherapy, when radiation kills tumor cells, it inevitably damages normal tissue cells. Objective To investigate the role of Toll-like receptor 4 (TLR4)/nuclear factor−kappa B (NF-κB) signaling pathway in the improvement of cognitive impairment induced by ionizing radiation by hydrogen-rich water before and after whole brain irradiation in rats. Methods Fifteen male SD rats were randomly divided into three groups: control group, irradiated group (IR group), and hydrogen-rich water intervention group (IR+HRW group), with 5 rats in each group. The control group was not irradiated, but was given purified water (20 mL·kg−1) by gavage every day, while the IR group and the IR+HRW group were irradiated with a single dose of 20 Gy. Three days before, 10 min before, and 30 days after irradiation, purified water/hydrogen-rich water (20 mL·kg−1) was given by continuous gavage every day. The general condition of the rats was observed every day, and the body weight were measured on the 7th, 14th, 21st, and 30th days after irradiation. On the 30th day after irradiation, the learning and memory ability of the rats was tested by Morris water maze; the pathological changes of hippocampus were detected by hematoxylin-eosin (HE) staining after sacrificing the rats; the contents of glutathione (GSH), malondialdehyde (MDA), interleukin-1β (IL-1β), and hydroxyl radicals in brain tissues were detected by enzyme linked immunosorbent assay (ELISA); the mRNA and protein expression levels of TLR4, NF-κB, NOD-like receptor pyrin domain 3 (NLRP3), and cysteinyl aspartate specific proteinase 1 (Caspase 1) were detected by quantitative real-time PCR (qRT-PCR) and Western blotting in the hippocampus of rats. Results After irradiation, the rats in the IR group showed symptoms such as head hair removal and salivation, while the symptoms of the rats in the IR+HRW group were milder. No animal died in the control and the IR+HRW groups, while one rat died in the IR group. From day 14 to day 30 after irradiation, the body weight of the rats in the IR+HRW group tended to be higher than that in the IR group, but the difference was not statistically significant (P>0.05). The Morris water maze results showed that the escape latency of the IR+HRW group was shortened compared with that of IR group from day 1 to day 5 except day 3, but the difference was not statistically significant (P>0.05). For the rats in the IR+HRW group, it took less time to reach the original location of the platform after removing the platform on day 6 and the number of crossing the platform and the residence time in the original platform quadrant increased (P<0.05). The HE staining showed that the number of hippocampal cells in the IR+HRW group was slightly reduced and arranged neatly, without obvious nuclear hyperchromatic and pyknotic phenomenon. The ELISA results showed that the MDA and hydroxyl radical levels were decreased in the IR+HRW group compared with the IR group (P<0.05), the GSH content was increased, and the IL-1β concentration was decreased, but the differences were not statistically significant (P>0.05). The results of qRT-PCR showed that the mRNA expression levels of TLR4 and Caspase 1 in the hippocampus of the IR+HRW group were decreased compared with the IR group (P<0.05), and the mRNA expression levels of NF-κB and NLRP3 were also decreased, but the differences were not statistically significant (P>0.05). The results of Western blotting showed that the expression levels of TLR4 and Caspase 1 protein in the hippocampus of the IR+HRW group were decreased compared with the IR group (P<0.05), and the expression levels of NF-κB p65 and NLRP3 protein were also decreased, but the differences were not statistically significant (P>0.05). Conclusion Hydrogen-rich water can improve cognitive impairment induced by ionizing radiation in rats, and its mechanism may be related to regulating TLR4/NF-κB signaling pathway, inhibiting inflammatory factors, and attenuating oxidative stress.
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Background At present, radiation therapy is widely used in clinical treatment of tumors. However, while radiation therapy damages tumor cells, it also injures surrounding normal tissues. Studies have shown that hydrogen is a potential radiation-protective agent. Objective To investigate the neuroprotective mechanisms of hydrogen-rich water activating phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/cysteinyl aspartate specificproteinase-9 (Caspase-9) signaling pathway in acute radiation-induced brain injury. Methods Forty male SD rats were randomly divided into four groups: control group, irradiation only group (IR), high-dose hydrogen-rich water intervention group (IR+HHRW), and low-dose hydrogen-rich water intervention group (IR+LHRW), 10 rats in each group. Except for the control group, animals in each group received a single 20 Gy whole brain irradiation. Animals in all groups were gavaged once a day from 3 d before irradiation to 7 d after irradiation, pure water (20 mL·kg−1) was given to the control and the IR groups, and hydrogen-rich water (20 mL·kg−1, 10 mL·kg−1) was given to the IR+HHRW and the IR+LHRW groups. After 7 d of intervention, 5 rats in each group were selected for the Morris water maze experiment for behavioral evaluation. Autopsies were conducted after anesthesia for the remaining animals and blood samples were collected for hematological analysis. Rat brains were harvested for TUNEL staining to observe neuronal apoptosis. HE staining was performed to observe histopathological changes, enzyme-linked immunosorbent assay was adopted to detect oxidative stress-related indicators, and real-time PCR and Western blotting were used to measure the expressions of PI3K/AKT/Caspase-9 pathway-related genes and proteins. Results The body weight of rats receiving irradiation decreased after 7 d of irradiation compared with the control group (P<0.05), and the symptoms such as arched back and malaise occurred to varying degrees, and the symptoms of rats in the IR+HHRW group were significantly milder than those in the IR group. The behavioral test results showed that the escape latency of rats in the IR+HHRW group or the IR+LHRW group was shorter than that in the IR group from day 2 to day 5 (P<0.05), and it took less time for rats in the IR+HHRW group to reach the original position after removing the platform on day 6 (P<0.05). The hematological test results showed that red blood cell (RBC) count, hemoglobin (HGB) level, and white blood cell (WBC) count were significantly decreased in the IR group (P<0.05), and the changes in the IR+HHRW group were improved (P<0.05). The HE staining results showed that the number of abnormal nerve cells, broken and dissolved nuclei, and the degree of damage in the IR+HHRW group were significantly reduced than those in the IR group. The results of oxidative stress evaluation showed that the ability of the IR group to inhibit free radicals decreased, the level of malondialdehyde (MDA) increased (P<0.01); the MDA level decreased after LHRW intervention (P<0.05); the SOD activity was elevated after HHRW intervention (P<0.05). The TUNEL staining results showed that the apoptosis signals in the IR+HHRW group were sparser than those in the IR group (P<0.05). The real-time PCR results showed that compared with the IR group, the mRNA expression levels of PI3K and AKT in the IR+HHRW group and the IR+LHRW group increased (P<0.05), while the mRNA expression levels of Cytc and Caspase-9 decreased (P<0.05). The Western blotting results showed that compared with the IR group, the phospho-AKT (pAKT) protein expression level in the IR+HHRW group increased significantly (P<0.05), while the expression of Caspase-9 and Cytc proteins decreased significantly (P<0.05). Conclusion Hydrogen-rich water can significantly reduce inflammation and oxidative stress caused by acute irradiation-induced brain injury, and decrease neuronal apoptosis. The mechanism may be related to the PI3K/AKT/Caspase-9 signaling pathway.
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Objective To investigate the endocytosis and exocytosis of soluble uranium in human kidney proximal tubular epithelial (HK-2) cells and the cytotoxicity after uranium exposure. Methods Cell Counting Kit-8 assay was used to determine the cell viability after different concentrations of uranium exposure, and optical microscopy and transmission electron microscopy were used to observe the changes in cells after uranium exposure. Inductively coupled plasma mass spectrometry was used to monitor the endocytosis and exocytosis of uranium over time by cells. Flow cytometry was used to assess the changes in cell cycle and apoptosis after uranium exposure. Results After uranium exposure, HK-2 cells showed dose-dependent damage; cell cycle was arrested in G1 phase; cell apoptosis and necrosis occurred; cell proliferation was inhibited. The content of endocytic uranium increased gradually within 24 h, and there was a threshold for uranium endocytosis, while the fraction of uranium binding to cell surface was low (< 0.2%). Over 40% of the endocytic uranium would be exocytosed within 1 h. Uranium could form needle-like precipitates in both intracellular and extracellular areas after uranium exposure. Conclusion After uranium exposure, cells show decreased viability, cell cycle arrest, and cell apoptosis. The process of endocytosis and exocytosis of soluble uranium is very rapid. HK-2 cells can convert soluble uranium into non-toxic precipitates.
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Objective@#To establish a method for the determination of aluminum in blood, and to detect the aluminum content in the blood of occupational aluminum workers.@*Methods@#The morning blood of the aluminum workers was collected in an anticoagulation tube, and the supernatant was centrifuged. The supernatant was diluted with 4% nitric acid containing 1% Triton for 24 h at room temperature, and the supernatant was centrifuged. The supernatant was filtered and the blood aluminum concentration was measured by inductively coupled plasma mass spectrometry and quantified by external standard method.@*Results@#The detection limit of ICP-MS method was 0.39 μg/L, the linear range was 0-160 μg/L, the recoveries were 98.24%-99.65%, and the precision was 0.19%-0.28%. The recoveries of graphite furnace atomic absorption spectrophotometry (GFAAS) were 97.17%-111.18%, and the precision was 0.35%-0.44%. The average blood aluminum concentration of aluminum workers in the normal control group was (19.87±10.65) μg/L. The average blood aluminum concentration of aluminum workers in the expose group was (31.12±11.43) μg/L.@*Conclusion@#The method of ICP-MS for the determination of aluminum concentration in blood has a simple pretreatment process, high recovery rate, low detection limit and high precision, which is suitable for popularization.
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Objective To investigate the protective effect of hydrogen-rich water on rat cognitive dysfunction induced by ionizing radiation.Methods A total of 20 SD rats were randomly divided into four groups with the ramdom number table method: control group(C),hydrogen-rich water group(HRW),irradiation group(IR)and hydrogen-rich water intervention group(HRW+IR),with 5 rats in each group.The spatial memory ability of rats was tested by a morris water maze.The expression of apoptosis-related genes was detected by real-time fluorescence quantitative PCR.The changes of glutathione(GSH),8-hydroxydeoxy guanosine(8-OHdG)and malondialdehyde(MDA)and SOD were also measured.Results The escape latency(F＝6.003,P＜0.05)and the swimming distances(F＝3.850,P＜0.05)of rats in four different groups had statistically significant differences.Compared with the IR group,the escape latency of the HRW+IR group was significantly decreased at 3,4,5 d after irradiation(P＜0.05),and the swimming distance of this group became much longer(P＜0.05).The levels of GSH,8-OHdG and MDA in these four groups had statistically significant differences(F＝6.450,5.033,4.113,P＜0.05).Compared with IR group,the concentration of GSH was increased(P＜0.05),but MDA and 8-OHdG decreased(P＜0.05)in the brain tissue of HRW+IR group,and the expressions of caspase-3,caspase-9 and bax genes were reduced(t＝2.956,3.087,5.246,P＜0.05),while the expression of bcl-2 gene was enhanced(t ＝-3.640,P ＜0.05)in the HRW+IR group.Conclusions Hydrogen-rich water attenuates the oxidative damage of ionizing radiation by neutralizing oxyhydrogen free radicals and thus protects brain from radiation damage.
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Objective To investigate the changes of gene expression profile in Beagle dogs' peripheral blood lymphocytes after acute irradiation.Methods Totally 20 male adult Beagle dogs were randomly divided into four groups including non-treatment blank control group and three radiation groups exposed to 0.5,2.0,and 5.0 Gy of γ-rays,respectively.Six hours after radiation,the peripheral blood were collected for lymphocytes isolation.Total RNA was extracted from the lymphocytes and analyzed by microarray hybridization.The differential gene profiles of radiation groups were analyzed by gene ontology (GO) analysis and kyoto encyclopedia of genes and genomes (KEGG) pathways analysis,and the alerted genes were further confirmed by the real time quantitative PCR (qRT-PCR) assay.Results Compared to the blank control group,the expressions of 308 genes in the radiation groups were perturbed over 2-fold of control,including 61 genes up-regulated and 247 genes down-regulated,which were mainly associated with immune response and cancer occurrence.The GO analysis indicated that the differential expressed genes were associated with cell connection,signal transduction,oxidation-reduction reaction and metabolism.The KEGG pathway analysis showed that some physiological and biochemical processes were involved,such as phagocytosis,tumor pathway,p53 signaling pathway,JAK-STAT signal pathway,cell differentiation,and proliferation,oxidative phosphorylation,glycogen dysplasia and other pathways.The microarray data of the alterations of apoptosis enhancing nuclease (AEN) and mitogenactivated protein kinase 13 (MAP3K13) gene expressions were further confirmed by qRT-PCR.Conclusions Exposure to different doses of acute γ-ray irradiation had significant impact on the gene expressions in Beagle dogs' peripheral blood lymphocytes and those differential expressed genes were related to a series of biological processes and pathways including immune response,metabolism and carcinogenesis.
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Objective To investigate the impacts of γ-ray radiation on gene expressions of peripheral blood lymphocytes in SD rats,and to screen differential expression genes and biological pathways closely related to radiation injury.Methods The differential gene expression of peripheral blood lymphocytes in SD rats was selected by microarray at 6 h after 2 Gy 60Co γ-ray exposure in vitro and in vivo.Bioinformatics analysis of the differentially expressed genes was performed by using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases.Real-time quantitative PCR was applied to verify the screen results of the microarray.Results Fifty-five genes with three times over-expressed level were screened out from the radiation groups both in vitro and in vivo and they were involved in 6 signaling pathways.There were two differentially expressed genes of microarray assay were verified by PCR assay.Conclusions Differential expressed genes in the peripheral blood lymphocytes of SD rats could be induced by γ-ray radiation and they cooperatively contributed to a variety of biological processes.
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<p><b>OBJECTIVE</b>To investigate the effect of aluminum exposure on neuronal apoptosis of rats hippocampus and the correlation of and synaptic plasticity.</p><p><b>METHODS</b>There were 40 SPF grade SD rats which were randomly divided into four groups: the control group, the low dose group, the medium dose group and the high dose group, 10 rats in each group. The rats were daily gavaged with aluminum lactate for 30 days. The hippocampal fEPSPs in rat was measured by electrophysiological grapher and the neuronal apoptosis in hippocampus was detected by Flow cytometer. In addition, the relative expression of gene which includes caspase-3, 8, 9 was measured by Real-time PCR.</p><p><b>RESULTS</b>Compared to the control group, the average of fEPSPs which after HFS 10, 20, 30, 40, 50, 60 min was decreased at different time point in the low dose group, the medium dose group and the high dose group (P < 0.05). Compared with the control group, the rate of apoptosis was significantly increased in the medium dose group and the high dose group (P < 0.05). Compared to the control group, the relative expression of caspase-3 in the medium dose group and the high dose group was significantly increased in Real-time PCR (P < 0.05), and the relative expression of caspase-8 in the high dose group was significantly increased (P < 0.05).</p><p><b>CONCLUSION</b>Aluminum exposure may induced neuronal apoptosis in rats, and then affect hippocampal synaptic plasticity.</p>
Subject(s)
Animals , Rats , Aluminum , Toxicity , Aluminum Compounds , Toxicity , Apoptosis , Caspase 3 , Metabolism , Caspase 8 , Metabolism , Hippocampus , Cell Biology , Lactates , Toxicity , Neuronal Plasticity , Neurons , Cell Biology , Rats, Sprague-DawleyABSTRACT
Objective To observe the protective effects of different doses of hydrogen-rich water on radiation injury in mice,so as to provide scientific basis for the application of hydrogen-rich water.Methods The ICR mice were randomly divided into control group,irradiation group,amifostine group and hydrogen-rich water of low,medium and high dose groups.The 30 days survival rate,body weight,hematology parameters,serum biochemical parameters,organ weight and coefficient,bone marrow micronucleus rate,bone marrow nucleated cell count were observed after total body irradiation with 9.0 Gy gamma rays.Results After 30 d of irradiation,the hydrogen-rich water showed obvious protective effect on the survival rate and body weight in a dose dependent manner so that the survival was significantly higher than that of irradiation group (t =-2.67,P ＜ 0.05).The biochemical index,such as TP,ALB and CRE in the low dose group,TP,ALB,TBIL and CRE in the medium dose group,and TP,ALB,GLU,TBIL,BUN,GRE and UA in the high dose group also indicated the protective effects of hydrogen-rich water (t =-2.04--4.11,P ＜ 0.05).But the protective effect of hydrogen-rich water was not observed in hematology,organ weight and coefficient,and bone marrow micronucleus induction.Conclusions The hydrogen-rich water has anti-radiation effect,which may depend on the dose of hydrogen.