27 research outputs found

    14-3-3σ-NEDD4L axis promotes ubiquitination and degradation of HIF-1α in colorectal cancer

    No full text
    Summary: A hypoxic microenvironment contributes to tumor progression, with hypoxia-inducible factor-1α (HIF-1α) being a critical regulator. We have reported that 14-3-3σ is negatively associated with HIF-1α expression; however, its role in hypoxia-induced tumor progression remains poorly characterized. Here we show that 14-3-3σ suppresses cancer hypoxia-induced metastasis and angiogenesis in colorectal cancer (CRC). 14-3-3σ opposes HIF-1α expression by regulating the protein stability of HIF-1α, thereby decreasing HIF-1α transcriptional activity and suppressing tumor progression. Mechanistic studies show that the 14-3-3σ-interacting protein neural precursor cell-expressed developmentally down-regulated 4-like (NEDD4L) is an E3 ligase that targets HIF-1α. 14-3-3σ promotes the binding of S448-phosphorylated NEDD4L to HIF-1α, thereby enhancing HIF-1α poly-ubiquitination and subsequent proteasome-mediated degradation. Consistent with this anti-tumorigenic function for 14-3-3σ, low 14-3-3σ expression levels correlate with poor CRC patient survival, and 14-3-3σ enhances the response of CRC to bevacizumab. These results reveal an important mechanism for 14-3-3σ in tumor suppression through HIF-1α regulation

    Delivery of epirubicin via slow infusion as a strategy to mitigate chemotherapy-induced cardiotoxicity.

    No full text
    Continuous infusion of doxorubicin has been a strategy to reduce cardiotoxicity. Epirubicin is another anthracycline in common clinical use. However, evidence is lacking regarding whether this strategy can reduce cardiotoxicity of epirubicin without compromising antineoplastic efficacy.Healthy rats were randomized into groups: epirubicin (8 mg/kg) delivered intraperitoneally via micro osmotic pumps (MOP), epirubicin (8 mg/kg) by intraperitoneal (IP) bolus injection, and placebo control. Blood samples were collected for analyzing biomarkers of myocardial injury and pharmacokinetics. At chosen times, sub-groups of animals were sacrificed for histopathology. A mouse breast cancer cell line (4T1), stably transfected with luciferase, was orthotopically allografted in female mice, and treated in three groups as described above for the rats. Tumor growth was monitored by measuring tumor size as well as bioluminescence.Delivery by IP bolus and by MOP achieved essentially the same area under the curve of epirubicin plasma concentration time profile. Blood biomarkers showed that the degree of myocardial injury in MOP group was lower than that of IP group. Histopathology showed that there was less eosinophilic enhancement, interstitial hemorrhage and necrotizing muscle atrophy in MOP group than IP group. In the orthotopic breast cancer allograft mouse model, the antineoplastic effect of epirubicin by MOP was not different from that by IP as measured by tumor weights or by in vivo bioluminescence.Slow delivery of epirubicin by MOP reduced cardiotoxicity without compromising the antineoplastic effect compared to IP bolus delivery. These in vivo data support our previous clinical data that continuous intravenous infusion of epirubicin using micro infusion pumps over 48-96 hours had less cardiotoxicity than intravenous bolus injections. However, whether multiple doses of epirubicin given by MOP result in a lower magnitude of long term cardiomyopathy remains to be further investigated

    Abnormal Bone Metabolism May Be a Primary Causative Factor of Keel Bone Fractures in Laying Hens

    No full text
    Keel bone damage negatively affects the welfare, production performance, egg quality, and mobility of laying hens. This study aimed to investigate whether abnormal bone metabolism causes keel bone damage in laying hens. Eighty Hy-line Brown laying hens were housed in eight furnished cages with 10 birds per cage and studied from 18 to 29 weeks of age (WOA). Accordingly, keel bone status was assessed at 18, 22, 25, and 29 WOA using the X-ray method, and the serum samples of laying hens with normal keel (NK), deviated keel (DK), and fractured keel (FK) that occurred at 29 WOA were collected across all the time-points. Subsequently, the serum samples were used to measure markers related to the metabolism of Ca and P and activities of osteoblast and osteoclast. The results showed that FK laying hens had lighter bodyweight than NK and DK birds throughout the trial (p < 0.05), while the keel bone length and weight were not different in NK, DK, and FK hens at 29 WOA (p > 0.05). Moreover, bone hematoxylin and eosin (H&E) staining and tartrate-resistant acid phosphatase (TRAP) staining indicated that damaged keel bone had evident pathological changes. In the FK hens, serum P level was reduced but serum 1,25-dihydroxy-vitamin D3 (1,25-(OH)2D3) and 25-hydroxyvitamin D3 (25-OHD3) levels were elevated compared to NK hens (p < 0.05). Additionally, DK hens had higher levels of serum 1,25-(OH)2D3, parathyroid hormone (PTH) and calcitonin (CT), and lower level of serum 25-OHD3 than the NK birds (p < 0.05). Furthermore, serum alkaline phosphatase (ALP), osteocalcin (OC), osteoprotegerin (OPG), TRAP, and corticosterone (CORT) levels were elevated in DK and FK hens compared to NK hens (p < 0.05). The levels of serum Ca, P, PTH, ALP, TRAP, OPG, OC, and CORT in laying hens fluctuated with the age of the birds. Generally, the results of this study indicate that keel bone damage, especially fractures, could be associated with abnormal bone metabolism in laying hens

    Safety and immunogenicity of an experimental live combination vaccine against enterovirus 71 and coxsackievirus A16 in rhesus monkeys

    No full text
    Enterovirus 71 (EV-A71) and Coxsackievirus A16 (CV-A16) are the two most common pathogens causing hand, foot, and mouth disease (HFMD). Previously, we obtained one candidate live attenuated strain each for EV-A71 and CV-A16; here, we evaluated the safety and immunogenicity of a combinedlive vaccine against EV-A71 and CV-A16 generated from these two candidate strains. Rhesus monkeys were intramuscularly treated with a live combinationvaccine against both EV-A71 and CV-A16 or with either vaccine alone. No fever or atypical clinical signs were observed in any animals. Monkeys vaccinated with the combinationlive vaccine presented no notable pathological changes in the brain, spinal cord, lung, and liver; in contrast, these regions showed inflammatory cell infiltration in monkeys treated with EV-A71 alone or CV-A16 alone. Weak viremia was detected in plasma after inoculation with the combinationvaccine; however, the duration of viral shedding in feces was increased. Biochemical studies revealed a slight increase in aspartate aminotransferase levels in monkeys inoculated with the live combination vaccine; however, histopathological findings did not attribute this change to liver damage. We also found that the live combinationvaccine induced a dual humoral immune response. Cytokine analysis indicated that the combined EV-A71/CV-A16 vaccine significantly down-regulated interleukin-8 production. Here, we have demonstrated that the live attenuated EV-A71/CV-A16 vaccine was safe and could trigger a dual specific immune response. However, its immune protection efficacy requires further investigation

    Surface structure-dependent pyrite oxidation in relatively dry and moist air: Implications for the reaction mechanism and sulfur evolution

    No full text
    Pyrite oxidation not only is environmentally significant in the formation of acid mine (or acid rock) drainage and oxidative acidification of lacustrine sediment but also is a critical stage in geochemical sulfur evolution. The oxidation process is always controlled by the reactivity of pyrite, which in turn is controlled by its surface structure. In this study, the oxidation behavior of naturally existing {100}, {111}, and {210} facets of pyrite was investigated using a comprehensive approach combining X-ray photoelectron spectroscopy, diffuse reflectance Fourier transform infrared spectroscopy, and time-of-flight secondary-ion mass spectrometry with periodic density functional theoretical (DFT) calculations. The experimental results show that (i) the initial oxidation rates of both pyrite {111} and {210} are much greater than that of pyrite {100}; (ii) the initial oxidation rate of pyrite {210} is greater than that of pyrite {111} in low relative humidity, which is reversed in high relative humidity; and (iii) inner sphere oxygen-bearing sulfur species are originally generated from surface reactions and then converted to outer sphere species. The facet dependent rate law can be expressed as: r({hkl}) = k({hkl})h(a)P(0.5) (t + 1)(-0.5), where r({hkl}) is the orientation dependent reaction rate, k{hkl} is the orientation dependent rate constant, h is the relative humidity, P is the oxygen partial pressure, and t is the oxidation time in seconds. {111} is the most sensitive facet for pyrite oxidation. Combined with DFT theoretical investigations, water catalyzed electron transfer is speculated as the rate-limiting step. These findings disclose the structure-reactivity dependence of pyrite, which not only presents new insight into the mechanism of pyrite oxidation but also provides fundamental data to evaluate sulfur speciation evolution, suggesting that the surface structure sensitivity should be considered to estimate the reactivity at the mineral-water interface. (C) 2018 Elsevier Ltd. All rights reserved

    Histopathology of epirubicin-induced myocardial damage.

    No full text
    <p>Representative photomicrographs of hematoxylin-eosin-stained slides of rat heart tissues from 3 groups of mice [control, epirubicin (bolus), and epirubicin (infusion)] are shown as labeled. Features such as focal interstitial hemorrhage (blue arrow), eosinophilic enhancement (solid black arrow), and wavy myocardial fibers (yellow arrow head) are indicated. Due to heart beats, paralyzed myocardial fibers become wavy, and this is a sign of loss of contractility.</p

    Equal <i>in vivo</i> antineoplastic efficacy of two methods of epirubicin administration.

    No full text
    <p>(A) Schematic representation of the experimental design and timing of data and sample collection from mice. (B) The tumor growth curves of orthotopic breast cancer allografts are shown for the three different groups of mice as labeled. Error bars represent standard errors; **, P<0.01; ***, P<0.001. (C) The photonic radiance from tumors was measured by bioluminescence imaging at 10 min post injection of D-luciferin. The error bars represent standard errors; *, P<0.05; **, P<0.01. (D) A representative comparison of bioluminescence intensity at 10 min in the three labeled groups of mice is shown. The color scale of the photon counts is labeled to the left of the images.</p

    A comparative study of multiple clinical enterovirus 71 isolates and evaluation of cross protection of inactivated vaccine strain FY-23 K-B in vitro

    No full text
    Abstract Background Enterovirus 71 (EV71) is one of the causative agents of hand, foot and mouth disease, which mostly affects infants and children and leads to severe neurological diseases. Vaccination offers the best option for disease control. We have screened the virus strain FY-23 K-B, which is used as an inactivated vaccine strain. An important issue in the development of vaccines is whether they provide cross protection against all other strains. Methods We collected and identified 19 clinical EV71 isolates from mainland China, which all belong to the C4 genotype. We established growth curves of the strains in Vero cells, performed genetic analysis, and evaluated the cross protection efficacy through neutralizing assays using antisera from a rabbit, monkey and adult human immunized with the FY-23 K-B vaccine strain. Results The antisera showed broad cross protection among the C4 subgroup strains and homotype strain. Neutralizing indexes (NIs) among the isolates and homotype strain of antisera varied between 56.2–1995.3 for rabbit, 17.8–42,169.7 for monkey and 31.6–17,782.8 for human, whereas NIs against Coxsackievirus A16 or other enteroviruses were below 10. Conclusions These results suggested that FY-23 K-B used as an antigen could elicit broad spectrum neutralizing antibodies with cross protective efficacy among C4 genotype strains

    Pharmacokinetic profiles of intraperitoneal bolus injection and intraperitoneal micro osmotic pump infusion in rats.

    No full text
    <p>(A) Schematic representation of the experimental design and timing of sample collection. (B) The mean plasma concentrations of the bolus group (solid black circle) and those of the pump infusion group (open circle) are as labeled. The error bars represent the 95% confidence intervals.</p
    corecore