60 research outputs found

    Up-regulation of MiR-205 under hypoxia promotes epithelial-mesenchymal transition by targeting ASPP2

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    The epithelial–mesenchymal transition (EMT) is one of the crucial procedures for cancer invasion and distal metastasis. Despite undergoing intensive studies, the mechanisms underlying EMT remain to be completely elucidated. Here, we identified that apoptosis-stimulating protein of p53-2 (ASPP2) is a novel target of MiR-205 in various cancers. Interestingly, the binding site of MiR-205 at the 3′-untranslated region of ASPP2 was highly conserved among different species. An inverse correlation between MiR-205 and ASPP2 was further observed in vivo in cervical cancers, suggesting MiR-205 may be an important physiological inhibitor of ASPP2. Hypoxia is a hallmark of solid tumor microenvironment and one of such conditions to induce EMT. Notably, MiR-205 was remarkably induced by hypoxia in cervical and lung cancer cells. A marked suppression of ASPP2 was observed simultaneously. Further studies confirmed that hypoxia-induced ASPP2 suppression was mainly attributed to the elevated MiR-205. Interestingly, the alteration of MiR-205/ASPP2 under hypoxia was accompanied with the decreased epithelial marker E-cadherin and increased mesenchymal marker Vimentin, as well as a morphological transition from the typical cobblestone-like appearance to the mesenchymal-like structure. More importantly, MiR-205 mimics or ASPP2 silencing similarly promoted EMT process. By contrast, ASPP2 recovery or MiR-205 inhibitor reversed MiR-205-dependent EMT. Further studies demonstrated that the newly revealed MiR-205/ASPP2 axis promoted cell migration and also increased cell proliferation both in vivo and in vitro. These data together implicated a critical impact of MiR-205/ASPP2 on promoting EMT. MiR-205/ASPP2 may be potential diagnostic and therapeutic biomarkers in cervical and lung cancers

    Analysis of index gases of coal spontaneous combustion using fourier transform infrared spectrometer

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    Analysis of the index gases of coal for the prevention of spontaneous combustion is of great importance for the enhancement of coal mine safety. In this work, Fourier Transform Infrared Spectrometer (FTIRS) is presented to be used to analyze the index gases of coal in real time to monitor spontaneous combustion conditions. Both the instrument parameters and the analysis method are introduced at first by combining characteristics of the absorption spectra of the target analyte with the analysis requirements. Next, more than ten sets of the gas mixture containing ten components (CH 4 , C 2 H 6 , C 3 H 8 , iso-C 4 H 10 , n-C 4 H 10 , C 2 H 4 , C 3 H 6 , C 2 H 2 , CO, and CO 2 ) are included and analyzed with a Spectrum Two FTIRS made by Perkin Elmer. The testing results show that the detection limit of most analytes is less than 2 × 10 −6 . All the detection limits meet the monitoring requirements of coal spontaneous combustion in China, which means that FTIRS may be an ideal instrument and the analysis method used in this paper is sufficient for spontaneous combustion gas monitoring on-line and even in situ, since FTIRS has many advantages such as fast analysis, being maintenance-free, and good safety

    Effect of Peripheral Administration of Kisspeptin-10 on Dynamic LH Secretion in Prepubertal Ewes

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    The aim of the present study was to clarify the effect of kisspeptin-10 on LH secretion in prepubertal ewes. In experiment 1, prepubertal ewes fitted with indwelling jugular catheters were randomly assigned to receive 0, 0.5, 1 or 2 mg of kisspeptin-10 dissolved in saline, and serial blood samples were collected at 15-min intervals for 180 min to analyze the response curves of LH after injection. In experiment 2, prepubertal ewes fitted with indwelling jugular catheters were injected with 0 or 1 mg of kisspeptin-10 dissolved in saline and the injection was repeated 3 times at 1 h interval and serial blood samples were collected at 15-min intervals for 210 min to analyze the response curves of LH after injection. The results showed that single intravenous administration of 0.5, 1 and 2 mg of kisspeptin-10 all could significantly increased LH secretion in prepubertal ewes, and the effect of 1 and 2 mg of kisspeptin-10 on LH secretion was higher than that of 0.5 mg group. The results also showed that repeated intravenous administration of kisspeptin-10 could effectively increase LH secretion and repeated administration did not influence the effect of kisspeptin-10 on LH secretion in prepubertal ewe. In conclusion, the present study indicated that single or repeated intravenous administration of kisspeptin-10 could effectively increase LH secretion in prepubertal ewes

    “Adjust Zang and arouse spirit” electroacupuncture ameliorates cognitive impairment by reducing endoplasmic reticulum stress in db/db mice

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    IntroductionDiabetic cognitive impairment (DCI) is a chronic complication of the central nervous system (CNS) caused by diabetes that affects learning and memory capacities over time. Recently, acupuncture has been shown to improve cognitive impairment in streptozotocin-induced diabetic rats. However, the effects of electroacupuncture on DCI and its underlying mechanism have not yet been elucidated in detail. MethodsIn this study, we used db/db mice as DCI animal models which showed low cognitive, learning and memory functions. Electroacupuncture significantly ameliorated DCI, which is reflected by better spatial learning and memory function using behavioral tests. The db/db mice with cognitive impairment were randomly divided into a model group (Mod) and an electroacupuncture treatment group (Acup), while db/m mice were used as a normal control group (Con). First, the mice were subjected to behavioural tests using the Morris water maze (MWM), and body weight, blood glucose, insulin, triglycerides (TG) and total cholesterol (TC) were observed; HE, Nissl, and TUNEL staining were used to observe the morphological changes and neuronal apoptosis in the mice hippocampus; Finally, Western blot and rt-PCR were applied to detect the essential proteins and mRNA of ERS and insulin signalling pathway, as well as the expression levels of Tau and Aβ.ResultsElectroacupuncture significantly ameliorated DCI, which is reflected by better spatial learning and memory function using behavioral tests. Moreover, electroacupuncture attenuated diabetes-induced morphological structure change, neuronal apoptosis in the hippocampus of db/db mice. Our results revealed that electroacupuncture could regulate the expression levels of Tau and Aβ by improving hippocampal ERS levels in db/db mice, inhibiting JNK activation, attenuating IRS1 serine phosphorylation, and restoring normal transduction of the insulin signaling pathway.DiscussionIn summary, ERS and insulin signaling pathway paly causal roles in DCI development. Electroacupuncture can significantly alleviate the pathogenesis of DCI, improve mice's learning and memory ability, and improve cognitive dysfunction. This study adds to our understanding of the effect of acupuncture on DCI and opens the door to further research on DCI

    The 5th International Conference on Biomedical Engineering and Biotechnology (ICBEB 2016)

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    Glucan phosphate inhibits HMGB-1 release from rat myocardial H9C2 cells in sepsis via TLR4/NF-кB signal pathway

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    Purpose: The effect of glucan phosphate (GP) on the release of HMGB-1 from rat myocardial cells (H9C2) during lipopolysaccharide-induced sepsis, and the underlying mechanisms, were investigated. Methods: H9C2 cells were divided into three groups: normal; lipopolysaccharide (LPS) (1 mg/ml LPS); and, LPS+GP (2 mg/ml GP). Western blot was used to determine toll-like receptor 4 (TLR4) levels, and electrophoretic mobility-shift assays (EMSA) was used to determine nuclear factor-кB (NF-кB) activity 3, 6 and 9 h after treatment. HMGB-1 mRNA levels in cultured cells were determined by real-time PCR and supernatant HMGB-1 protein levels were evaluated by ELISA at 12, 24, 36 and 48 h after treatment. Following the transfection of H9C2 cells with Ad5-IкBα, which inhibits NF-кB activity, TLR4, NF-кB and HMGB-1 levels were determined. Results: Intracellular TLR4 levels and NF-кB activity in LPS and LPS+GP groups increased 3-9 h after stimulation, but the increased levels of TLR4 and elevated activity of NF-кB were significantly lower in the LPS+GP group vs. the LPS group. HMGB-1 mRNA levels in both LPS and LPS+GP groups, increased gradually from 24 h after stimulation, but the increase was more obvious in the LPS group vs. the LPS+GP group. Supernatant HMGB-1 levels in the LPS and LPS+GP groups increased gradually from 9 h after stimulation, and also increased markedly in the LPS group. After the inhibition of NF-кB activity, LPS-induced HMGB-1 release decreased significantly (

    Two independent positive feedbacks and bistability in the Bcl-2 apoptotic switch.

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    BackgroundThe complex interplay between B-cell lymphoma 2 (Bcl-2) family proteins constitutes a crucial checkpoint in apoptosis. Its detailed molecular mechanism remains controversial. Our former modeling studies have selected the 'Direct Activation Model' as a better explanation for experimental observations. In this paper, we continue to extend this model by adding interactions according to updating experimental findings.Methodology/principal findingsThrough mathematical simulation we found bistability, a kind of switch, can arise from a positive (double negative) feedback in the Bcl-2 interaction network established by anti-apoptotic group of Bcl-2 family proteins. Moreover, Bax/Bak auto-activation as an independent positive feedback can enforce the bistability, and make it more robust to parameter variations. By ensemble stochastic modeling, we also elucidated how intrinsic noise can change ultrasensitive switches into gradual responses. Our modeling result agrees well with recent experimental data where bimodal Bax activation distributions in cell population were found.Conclusions/significanceAlong with the growing experimental evidences, our studies successfully elucidate the switch mechanism embedded in the Bcl-2 interaction network and provide insights into pharmacological manipulation of Bcl-2 apoptotic switch as further cancer therapies
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