215 research outputs found

    Algebraic Quantum Error-Correction Codes

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    Based on the group structure of a unitary Lie algebra, a scheme is provided to systematically and exhaustively generate quantum error correction codes, including the additive and nonadditive codes. The syndromes in the process of error-correction distinguished by different orthogonal vector subspaces, the coset subspaces. Moreover, the generated codes can be classified into four types with respect to the spinors in the unitary Lie algebra and a chosen initial quantum state

    Plasma Membrane Association but Not Midzone Recruitment of RhoGEF ECT2 Is Essential for Cytokinesis

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    Cytokinesis, the final step of cell division, begins with the formation of a cleavage furrow. How the mitotic spindle specifies the furrow at the equator in animal cells remains unknown. Current models propose that the concentration of the RhoGEF ECT2 at the spindle midzone and the equatorial plasma membrane directs furrow formation. Using chemical genetic and optogenetic tools, we demonstrate that the association of ECT2 with the plasma membrane during anaphase is required and sufficient for cytokinesis. Local membrane targeting of ECT2 leads to unilateral furrowing, highlighting the importance of local ECT2 activity. ECT2 mutations that prevent centralspindlin binding compromise concentration of ECT2 at the midzone and equatorial membrane but sustain cytokinesis. While the association of ECT2 with the plasma membrane is essential for cytokinesis, our data suggest that ECT2 recruitment to the spindle midzone is insufficient to account for equatorial furrowing and may act redundantly with yet-uncharacterized signals.Cancer Research U

    Kinetochore genes are coordinately up-regulated in human tumors as part of a FoxM1-related cell division program

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    The key player in directing proper chromosome segregation is the macromolecular kinetochore complex, which mediates DNA–microtubule interactions. Previous studies testing individual kinetochore genes documented examples of their overexpression in tumors relative to normal tissue, leading to proposals that up-regulation of specific kinetochore genes may promote tumor progression. However, kinetochore components do not function in isolation, and previous studies did not comprehensively compare the expression behavior of kinetochore components. Here we analyze the expression behavior of the full range of human kinetochore components in diverse published expression compendia, including normal tissues and tumor samples. Our results demonstrate that kinetochore genes are rarely overexpressed individually. Instead, we find that core kinetochore genes are coordinately regulated with other cell division genes under virtually all conditions. This expression pattern is strongly correlated with the expression of the forkhead transcription factor FoxM1, which binds to the majority of cell division promoters. These observations suggest that kinetochore gene up-regulation in cancer reflects a general activation of the cell division program and that altered expression of individual kinetochore genes is unlikely to play a causal role in tumorigenesis.Leukemia & Lymphoma Society of America (Scholar Award)National Institute of General Medical Sciences (U.S.) (Grant GM088313)American Cancer Society (Research Scholar Grant 121776)National Science Foundation (U.S.). Graduate Research Fellowshi

    Metabolic syndrome and abdominal fat are associated with inflammation, but not with clinical outcomes, in peritoneal dialysis patients

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    BACKGROUND: In the general population, metabolic syndrome (MetS) is correlated with visceral fat and a risk factor for cardiovascular disease (CVD); however, little is known about the significance of abdominal fat and its association with inflammation and medication use in peritoneal dialysis (PD) patients. We investigated the relationship of visceral fat area (VFA) with C-reactive protein (CRP) levels and medication use in PD patients and followed their clinical outcomes. METHODS: In a prospective study from February 2009 to February 2012, we assessed diabetes mellitus (DM) status, clinical and PD-associated characteristics, medication use, CRP levels, components of MetS, and VFA in 183 PD patients. These patients were categorized into 3 groups based on MetS and DM status: non-MetS (group 1, n = 73), MetS (group 2, n = 65), and DM (group 3, n = 45). VFA was evaluated by computed tomography (CT) and corrected for body mass index (BMI). RESULTS: Patients in group 1 had smaller VFAs than patients in groups 2 and 3 (3.2 ± 1.8, 4.6 ± 1.9, and 4.9 ± 2.0 cm(2)/[kg/m(2)], respectively, P < 0.05) and lower CRP levels (0.97 ± 2.31, 1.27 ± 2.57, and 1.11 ± 1.35 mg/dL, respectively, P < 0.05). VFA increased with the number of criteria met for MetS. After adjusting for age, body weight, and sex, CRP and albumin levels functioned as independent positive predictors of VFA; on other hand, the use of renin-angiotensin system blockers was inversely correlated with VFA in PD patients without DM. In the survival analysis, DM patients (group 3) had the poorest survival among the 3 groups, but no significant differences were found between groups 1 and 2. CONCLUSION: This study showed that VFA and MetS are associated with CRP levels but cannot predict survival in PD patients without DM. The complex relationship of nutritional parameters to VFA and MetS may explain these results. The type of antihypertensive medication used was also associated with the VFA. The mechanisms behind these findings warrant further investigation

    Novel Ultrasonographic Fatty Liver Indicator Can Predict Hepatitis in Children With Non-alcoholic Fatty Liver Disease

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    Background: Childhood non-alcoholic fatty liver disease (NAFLD) is a public health issue worldwide. To date, liver biopsy remains the gold standard for diagnosing the severity of NAFLD. However, this invasive procedure might contribute to complications. Owing to this reason, a good non-invasive tool to estimate NAFLD in children is urgently needed. We sought to investigate whether a non-invasive semi-quantitative ultrasonographic fatty liver indicator (US-FLI) can estimate NAFLD in children.Methods: Children aged between 10 and 18 years were enrolled prospectively. Abdominal ultrasonography was performed by a single experienced pediatric gastroenterologist and the non-invasive semi-quantitative US-FLI score were used. Patients were diagnosed with NAFLD if they had a US-FLI score ≥2. The anthropometric measures, obesity-related biochemical results, and levels of tumor necrosis factor-α, interleukin-6, caspase-cleaved cytokeratin fragment of cytokeratin 18 (M30), and adiponectin were also checked.Results: Overall, 117 children aged 10–18 years were enrolled. The anthropometric measures and obesity-related biochemical parameters (hsCRP, triglyceride, uric acid, AST, ALT, γ-GT, homeostatic model assessment insulin resistance (HOMA-IR), and M30) were significantly higher in the obesity group than in the non-obesity group (p &lt; 0.05). Similarly, the US-FLI score was significantly higher in the obesity group than that in the non-obesity group (p &lt; 0.001). Multiple linear regression showed that the US-FLI score was significantly associated with the waist-to-height ratio, uric acid, adiponectin, and M30 levels (all p &lt; 0.05) in children with obesity. The US-FLI score ≥6 was the optimal cut-off point for predicting the hepatitis in children with NAFLD. The area under the receiver operating characteristic curve was 0.710 (95% CI: 0.572–0.847; p = 0.005).Conclusions: The non-invasive US-FLI score can predict hepatitis in children with NAFLD without mandatory liver biopsy. Moreover, the waist-to-height ratio, uric acid, adiponectin, and M30 levels were significantly associated with US-FLI score in children with obesity

    HLJ1 is a novel caspase-3 substrate and its expression enhances UV-induced apoptosis in non-small cell lung carcinoma

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    Carcinogenesis is determined based on both cell proliferation and death rates. Recent studies demonstrate that heat shock proteins (HSPs) regulate apoptosis. HLJ1, a member of the DnaJ-like Hsp40 family, is a newly identified tumor suppressor protein closely related to relapse and survival in non-small cell lung cancer (NSCLC) patients. However, its role in apoptosis is currently unknown. In this study, NSCLC cell lines displaying varying HLJ1 expression levels were subjected to ultraviolet (UV) irradiation, followed by flow cytometry. Interestingly, the percentages of apoptotic cells in the seven cell lines examined were positively correlated with HLJ1 expression. Enforcing expression of HLJ1 in low-HLJ1 expressing highly invasive cells promoted UV-induced apoptosis through enhancing JNK and caspase-3 activation in NSCLC. Additionally, UV irradiation led to reduced levels of HLJ1 predominantly in apoptotic cells. The pan-caspase inhibitor, zVAD-fmk and caspase-3-specific inhibitor, DEVD-fmk, prevented UV-induced degradation of HLJ1 by the late stage of apoptosis. Further experiments revealed a non-typical caspase-3 cleavage site (MEID) at amino acid 125–128 of HLJ1. Our results collectively suggest that HLJ1 is a novel substrate of caspase-3 during the UV-induced apoptotic process

    Factor quinolinone inhibitors disrupt spindles and multiple LSF (TFCP2)-protein interactions in mitosis, including with microtubule-associated proteins

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    Factor quinolinone inhibitors (FQIs), a first-in-class set of small molecule inhibitors targeted to the transcription factor LSF (TFCP2), exhibit promising cancer chemotherapeutic properties. FQI1, the initial lead compound identified, unexpectedly induced a concentration-dependent delay in mitotic progression. Here, we show that FQI1 can rapidly and reversibly lead to mitotic arrest, even when added directly to mitotic cells, implying that FQI1-mediated mitotic defects are not transcriptionally based. Furthermore, treatment with FQIs resulted in a striking, concentration-dependent diminishment of spindle microtubules, accompanied by a concentration-dependent increase in multi-aster formation. Aberrant γ-tubulin localization was also observed. These phenotypes suggest that perturbation of spindle microtubules is the primary event leading to the mitotic delays upon FQI1 treatment. Previously, FQIs were shown to specifically inhibit not only LSF DNA-binding activity, which requires LSF oligomerization to tetramers, but also other specific LSF-protein interactions. Other transcription factors participate in mitosis through non-transcriptional means, and we recently reported that LSF directly binds α-tubulin and is present in purified cellular tubulin preparations. Consistent with a microtubule role for LSF, here we show that LSF enhanced the rate of tubulin polymerization in vitro, and FQI1 inhibited such polymerization. To probe whether the FQI1-mediated spindle abnormalities could result from inhibition of mitotic LSF-protein interactions, mass spectrometry was performed using as bait an inducible, tagged form of LSF that is biotinylated by endogenous enzymes. The global proteomics analysis yielded expected associations for a transcription factor, notably with RNA processing machinery, but also to nontranscriptional components. In particular, and consistent with spindle disruption due to FQI treatment, mitotic, FQI1-sensitive interactions were identified between the biotinylated LSF and microtubule-associated proteins that regulate spindle assembly, positioning, and dynamics, as well as centrosome-associated proteins. Probing the mitotic LSF interactome using small molecule inhibitors therefore supported a non-transcriptional role for LSF in mediating progression through mitosis.UL1 TR001430 - NCATS NIH HHS; R01 GM078240 - NIGMS NIH HHSPublished versio
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