Because of a lack of sensitive biomarkers,the diagnosis of Alzheimer＇s disease（AD） cannot be made prior to symptom manifestation.Therefore,it is crucial to identify novel biomarkers for the presymptomatic diagnosis...Because of a lack of sensitive biomarkers,the diagnosis of Alzheimer＇s disease（AD） cannot be made prior to symptom manifestation.Therefore,it is crucial to identify novel biomarkers for the presymptomatic diagnosis of AD.While brain lesions are a major feature of AD,retinal pathological changes also occur in patients.In this study,we investigated the temporal changes in β-site APP-cleaving enzyme 1（BACE1） expression in the retina and brain to determine whether it could serve as a suitable biomarker for early monitoring of AD.APP/PS-1 transgenic mice,3,6 and 8 months of age,were used as an experimental group,and age-matched C57/BL6 wild-type mice served as the control group.In the Morris water maze test,there were no significant differences in escape latency or in the number of crossings in the target area among mice of different ages.Compared with wild-type mice,no changes in learning or memory abilities were detected in transgenic mice at 3 months of age.However,compared with wild-type mice,the escape latency was significantly increased in transgenic mice at 6 months,starting on day 3,and at 8 months,starting on day 2,during Morris water maze training.In addition,the number of crossings of the target area was significantly decreased in transgenic mice.The learning and memory abilities of transgenic mice were further worsened at 8 months of age.Immunohistochemical staining revealed no BACE1 plaques in wild-type mice at 3,6 or 8 months or in transgenic mice at 3 months,but they were clearly found in the entorhinal cortex,hippocampus and prefrontal cortex of transgenic mice at 6 and 8 months.BACE1 expression was not detected in the retina of wild-type mice at 3 months,but weak BACE1 expression was detected in the ganglion cell layer,inner plexiform layer and outer plexiform layer at 6 and 8 months.In transgenic mice,BACE1 expression in the ganglion cell layer was increased at 3 months,and BACE1 expression in the ganglion cell layer,inner plexiform layer and outer plexiform layer was significantly increased at 6 and 8 months,compared with age-matched wild-type mice.Taken together,these results indicate that changes in BACE1 expression appear earlier in the retina than in the brain and precede behavioral deficits.Our findings suggest that abnormal expression of BACE1 in the retina is an early pathological change in APP/PS-1 transgenic mice,and that BACE1 might have potential as a biomarker for the early diagnosis of AD in humans.展开更多
Bone marrow mesenchymal stem cells (MSCs) can differentiate into smooth muscle cells (SMCs) and have tremendous potential for cell therapy and tissue engineering. In this study, to understand the effects of TGF-β3 on...Bone marrow mesenchymal stem cells (MSCs) can differentiate into smooth muscle cells (SMCs) and have tremendous potential for cell therapy and tissue engineering. In this study, to understand the effects of TGF-β3 on rat bone marrow-derived MSCs and the underlying molecular mechanism of this differentiation process, we investigated that the changes of myocardin-related transcription factors (MRTFs) at the transcriptional level after rat MSCs were treated with TGF-β3. The results showed that TGF-β3 increased the expression of contractile genes, such as SM22, smooth muscle-myosin heavy chain (SM- MHC), SM-α-actin in MSCs. When TGF-β3 induced MSCs differentiation into SMCs, myocardin and MRTF-A were activated. The data indicated that TGF-β3 induced rat bone marrow-derived MSCs differentiation into SMCs by activating mypcardin and MRTF-A.展开更多
Myocardin-related transcription factors A (MRTF-A) is a myocardin-related transcription factor that have been found strongly activated CarG box–containing genes through its direct binding to serum response factor (SR...Myocardin-related transcription factors A (MRTF-A) is a myocardin-related transcription factor that have been found strongly activated CarG box–containing genes through its direct binding to serum response factor (SRF). In the present study, the MRTF-A ex-pression vector was constructed. The MTT assay showed that transfection of MRTF-A could significantly decrease the anti-tumor effect of tamoxifen on MCF-7 breast cancer cells. The bioinformatics analysis found that the CarG element existed in the pro-moter region of COMT gene of many familiar verte-brates, including of human, rhesus macaque, chimpanzee, etc. The results of RT-PCR assay further showed that MRTF-A could enhance the transcrip-tion level of COMT. These results are the first to indicate that COMT might be a target gene which could be regulated by MRTF-A/SRF, and such transactivation event might be involved in the process of tamoxifen resistance.展开更多
Human industrial activities have caused environmental uranium(U) pollution, resulting in uranium(Ⅵ) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characteriz...Human industrial activities have caused environmental uranium(U) pollution, resulting in uranium(Ⅵ) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characterized by X-ray fluorescence(XRF), and Fourier transform infrared reflection(FT-IR), as well as by GC/MS metabolomics analysis, to study the response to uranium(Ⅵ) stress. The biomass of Penicillium decreased after exposure to 100 mg/L U.Uranium combined with carboxyl groups, amino groups, and phosphate groups to form uranium mineralized deposits on the surface of this fungal strain. The α-activity concentration of uranium in the strain was 2.57×10^(6)Bq/kg, and the β-activity concentration was 2.27×10^(5)Bq/kg. Metabolomics analysis identified 118 different metabolites, as well as metabolic disruption of organic acids and derivatives. Further analysis showed that uranium significantly affected the metabolism of 9 amino acids in Penicillium. These amino acids were related to the TCA cycle and ABC transporter. At the same time, uranium exhibited nucleotide metabolism toxicity to Penicillium. This study provides an in-depth understanding of the uranium tolerance mechanism of Penicillium and provides a theoretical basis for Penicillium to degrade hyper-enriched plants.展开更多
A novel sorbent for the removal of uranyl ion was prepared by expanded rice husk powder. Batch adsorption experiments were performed on factors of p H,temperature, initial uranyl ion concentration, adsorbent dosage an...A novel sorbent for the removal of uranyl ion was prepared by expanded rice husk powder. Batch adsorption experiments were performed on factors of p H,temperature, initial uranyl ion concentration, adsorbent dosage and contact time to evaluate the adsorption capacity. The results show that the saturation adsorption capacity is 5.7 mg·g^-1 using expanded rice husk powder treating uranyl ion aqueous solution（80 mg·g^-1） for 24 h at 25 ℃ with initial pH3. Adsorption process could be well described by Langmuir isotherm model. The adsorption kinetic data are fitted well with pseudo-second-order model. The results obtained show that expanded rice husk adsorbent is a promising adsorbent for the removal of uranium from aqueous solutions.展开更多
基金supported by the National Natural Science Foundation of China(to JFH,DC,JBT),No.81371011,81400399,81471107a grant from the Project of Innovation-driven Plan of Central South University(to DC),No.2015CXS022+2 种基金a grant from the National Key Technologies Research and Development Program of China(to JFH),No.2012BAK14B03Fundamental Research Funds of Central South University of China(to HW),No.2010QZZD022Graduate Thesis Innovation Foundation of Central South University of China(to LL),No.2011ssxt106
文摘Because of a lack of sensitive biomarkers,the diagnosis of Alzheimer＇s disease（AD） cannot be made prior to symptom manifestation.Therefore,it is crucial to identify novel biomarkers for the presymptomatic diagnosis of AD.While brain lesions are a major feature of AD,retinal pathological changes also occur in patients.In this study,we investigated the temporal changes in β-site APP-cleaving enzyme 1（BACE1） expression in the retina and brain to determine whether it could serve as a suitable biomarker for early monitoring of AD.APP/PS-1 transgenic mice,3,6 and 8 months of age,were used as an experimental group,and age-matched C57/BL6 wild-type mice served as the control group.In the Morris water maze test,there were no significant differences in escape latency or in the number of crossings in the target area among mice of different ages.Compared with wild-type mice,no changes in learning or memory abilities were detected in transgenic mice at 3 months of age.However,compared with wild-type mice,the escape latency was significantly increased in transgenic mice at 6 months,starting on day 3,and at 8 months,starting on day 2,during Morris water maze training.In addition,the number of crossings of the target area was significantly decreased in transgenic mice.The learning and memory abilities of transgenic mice were further worsened at 8 months of age.Immunohistochemical staining revealed no BACE1 plaques in wild-type mice at 3,6 or 8 months or in transgenic mice at 3 months,but they were clearly found in the entorhinal cortex,hippocampus and prefrontal cortex of transgenic mice at 6 and 8 months.BACE1 expression was not detected in the retina of wild-type mice at 3 months,but weak BACE1 expression was detected in the ganglion cell layer,inner plexiform layer and outer plexiform layer at 6 and 8 months.In transgenic mice,BACE1 expression in the ganglion cell layer was increased at 3 months,and BACE1 expression in the ganglion cell layer,inner plexiform layer and outer plexiform layer was significantly increased at 6 and 8 months,compared with age-matched wild-type mice.Taken together,these results indicate that changes in BACE1 expression appear earlier in the retina than in the brain and precede behavioral deficits.Our findings suggest that abnormal expression of BACE1 in the retina is an early pathological change in APP/PS-1 transgenic mice,and that BACE1 might have potential as a biomarker for the early diagnosis of AD in humans.
文摘Bone marrow mesenchymal stem cells (MSCs) can differentiate into smooth muscle cells (SMCs) and have tremendous potential for cell therapy and tissue engineering. In this study, to understand the effects of TGF-β3 on rat bone marrow-derived MSCs and the underlying molecular mechanism of this differentiation process, we investigated that the changes of myocardin-related transcription factors (MRTFs) at the transcriptional level after rat MSCs were treated with TGF-β3. The results showed that TGF-β3 increased the expression of contractile genes, such as SM22, smooth muscle-myosin heavy chain (SM- MHC), SM-α-actin in MSCs. When TGF-β3 induced MSCs differentiation into SMCs, myocardin and MRTF-A were activated. The data indicated that TGF-β3 induced rat bone marrow-derived MSCs differentiation into SMCs by activating mypcardin and MRTF-A.
文摘Myocardin-related transcription factors A (MRTF-A) is a myocardin-related transcription factor that have been found strongly activated CarG box–containing genes through its direct binding to serum response factor (SRF). In the present study, the MRTF-A ex-pression vector was constructed. The MTT assay showed that transfection of MRTF-A could significantly decrease the anti-tumor effect of tamoxifen on MCF-7 breast cancer cells. The bioinformatics analysis found that the CarG element existed in the pro-moter region of COMT gene of many familiar verte-brates, including of human, rhesus macaque, chimpanzee, etc. The results of RT-PCR assay further showed that MRTF-A could enhance the transcrip-tion level of COMT. These results are the first to indicate that COMT might be a target gene which could be regulated by MRTF-A/SRF, and such transactivation event might be involved in the process of tamoxifen resistance.
基金supported by the State Key Laboratory of NBC Protection for Civilian Open Fund Project (No. SKLNBC201921)。
文摘Human industrial activities have caused environmental uranium(U) pollution, resulting in uranium(Ⅵ) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characterized by X-ray fluorescence(XRF), and Fourier transform infrared reflection(FT-IR), as well as by GC/MS metabolomics analysis, to study the response to uranium(Ⅵ) stress. The biomass of Penicillium decreased after exposure to 100 mg/L U.Uranium combined with carboxyl groups, amino groups, and phosphate groups to form uranium mineralized deposits on the surface of this fungal strain. The α-activity concentration of uranium in the strain was 2.57×10^(6)Bq/kg, and the β-activity concentration was 2.27×10^(5)Bq/kg. Metabolomics analysis identified 118 different metabolites, as well as metabolic disruption of organic acids and derivatives. Further analysis showed that uranium significantly affected the metabolism of 9 amino acids in Penicillium. These amino acids were related to the TCA cycle and ABC transporter. At the same time, uranium exhibited nucleotide metabolism toxicity to Penicillium. This study provides an in-depth understanding of the uranium tolerance mechanism of Penicillium and provides a theoretical basis for Penicillium to degrade hyper-enriched plants.
基金financially supported by the National Natural Science Foundation of China (No. 21406182)the National Decommissioning of Nuclear Facilities and Radioactive Waste Management Research Projects Focus, State Administration of Science, Technology and Industry for National Defense (SASTIND), China (No. 2014-806)the Science and Technology Project of Qinghai Province (No. 2014-GX-Q04)
文摘A novel sorbent for the removal of uranyl ion was prepared by expanded rice husk powder. Batch adsorption experiments were performed on factors of p H,temperature, initial uranyl ion concentration, adsorbent dosage and contact time to evaluate the adsorption capacity. The results show that the saturation adsorption capacity is 5.7 mg·g^-1 using expanded rice husk powder treating uranyl ion aqueous solution（80 mg·g^-1） for 24 h at 25 ℃ with initial pH3. Adsorption process could be well described by Langmuir isotherm model. The adsorption kinetic data are fitted well with pseudo-second-order model. The results obtained show that expanded rice husk adsorbent is a promising adsorbent for the removal of uranium from aqueous solutions.
