28 research outputs found

    Xpo7 is a broad-spectrum exportin and a nuclear import receptor

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    Exportins bind cargo molecules in a RanGTP-dependent manner inside nuclei and transport them through nuclear pores to the cytoplasm. CRM1/Xpo1 is the best-characterized exportin because specific inhibitors such as leptomycin B allow straightforward cargo validations in vivo. The analysis of other exportins lagged far behind, foremost because no such inhibitors had been available for them. In this study, we explored the cargo spectrum of exportin 7/Xpo7 in depth and identified not only ∌200 potential export cargoes but also, surprisingly, ∌30 nuclear import substrates. Moreover, we developed anti-Xpo7 nanobodies that acutely block Xpo7 function when transfected into cultured cells. The inhibition is pathway specific, mislocalizes export cargoes of Xpo7 to the nucleus and import substrates to the cytoplasm, and allowed validation of numerous tested cargo candidates. This establishes Xpo7 as a broad-spectrum bidirectional transporter and paves the way for a much deeper analysis of exportin and importin function in the future

    Osteoblasts mediate the adverse effects of glucocorticoids on fuel metabolism

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    Long-term glucocorticoid treatment is associated with numerous adverse outcomes, including weight gain, insulin resistance, and diabetes; however, the pathogenesis of these side effects remains obscure. Glucocorticoids also suppress osteoblast function, including osteocalcin synthesis. Osteocalcin is an osteoblast-specific peptide that is reported to be involved in normal murine fuel metabolism. We now demonstrate that osteoblasts play a pivotal role in the pathogenesis of glucocorticoid-induced dysmetabolism. Osteoblast-targeted disruption of glucocorticoid signaling significantly attenuated the suppression of osteocalcin synthesis and prevented the development of insulin resistance, glucose intolerance, and abnormal weight gain in corticosterone-treated mice. Nearly identical effects were observed in glucocorticoid-treated animals following heterotopic (hepatic) expression of both carboxylated and uncarboxylated osteocalcin through gene therapy, which additionally led to a reduction in hepatic lipid deposition and improved phosphorylation of the insulin receptor. These data suggest that the effects of exogenous high-dose glucocorticoids on insulin target tissues and systemic energy metabolism are mediated, at least in part, through the skeleton.NHMRC Grants 402462 and 63281

    The German National Pandemic Cohort Network (NAPKON): rationale, study design and baseline characteristics

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    Schons M, Pilgram L, Reese J-P, et al. The German National Pandemic Cohort Network (NAPKON): rationale, study design and baseline characteristics. European Journal of Epidemiology . 2022.The German government initiated the Network University Medicine (NUM) in early 2020 to improve national research activities on the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic. To this end, 36 German Academic Medical Centers started to collaborate on 13 projects, with the largest being the National Pandemic Cohort Network (NAPKON). The NAPKON's goal is creating the most comprehensive Coronavirus Disease 2019 (COVID-19) cohort in Germany. Within NAPKON, adult and pediatric patients are observed in three complementary cohort platforms (Cross-Sectoral, High-Resolution and Population-Based) from the initial infection until up to three years of follow-up. Study procedures comprise comprehensive clinical and imaging diagnostics, quality-of-life assessment, patient-reported outcomes and biosampling. The three cohort platforms build on four infrastructure core units (Interaction, Biosampling, Epidemiology, and Integration) and collaborations with NUM projects. Key components of the data capture, regulatory, and data privacy are based on the German Centre for Cardiovascular Research. By April 01, 2022, 34 university and 40 non-university hospitals have enrolled 5298 patients with local data quality reviews performed on 4727 (89%). 47% were female, the median age was 52 (IQR 36-62-) and 50 pediatric cases were included. 44% of patients were hospitalized, 15% admitted to an intensive care unit, and 12% of patients deceased while enrolled. 8845 visits with biosampling in 4349 patients were conducted by April 03, 2022. In this overview article, we summarize NAPKON's design, relevant milestones including first study population characteristics, and outline the potential of NAPKON for German and international research activities.Trial registration https://clinicaltrials.gov/ct2/show/NCT04768998 . https://clinicaltrials.gov/ct2/show/NCT04747366 . https://clinicaltrials.gov/ct2/show/NCT04679584. © 2022. The Author(s)

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    “Scanxiety” and a sense of control: the perspective of lung cancer survivors and their caregivers on follow-up - a qualitative study

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    Abstract Objectives Lung cancer survivors often suffer from physical, emotional and social long-term effects of disease and treatment. Caregivers are also affected by the cancer diagnosis throughout the course of the disease and are frequently burdened by high levels of psychosocial stress. However, little is known about how follow-up care after the completed treatment phase can help to improve long-term quality of life. In the context of patient-centred cancer care, considering the survivors’ and caregivers’ perspectives is an important step toward improving care structures. We therefore explored how lung cancer survivors and their caregivers experience follow-up examinations and their possible psychosocial effects on everyday life in order to shed light on what support is helpful for improving their quality of life. Material and Methods 25 survivors after curative lung cancer treatment and 17 caregivers underwent a face-to-face semi-structured, audio-recorded interview that was analysed using qualitative content analysis. Results Especially burdened cancer survivors and caregivers described recurring anxiety before a follow-up appointment influencing their everyday life. At the same time, follow-up care also provided reassurance of still being healthy and helped regain a sense of security and control until the following scan. Despite possible long-term consequences in everyday life, the interviewees reported that the survivors® psychosocial needs were not explicitly assessed or discussed. Nevertheless, the interviewees indicated that conversations with the physician were important for the success of “good” follow-up care. Conclusion Anxiety surrounding follow-up scans, also known as “scanxiety”, is a common problem. In this study, we expanded on previous findings and found a positive aspect of scans, namely regaining a sense of security and control, which can strengthen the psychological well-being of the survivors and their families. To optimize follow-up care and improve the quality of life of lung cancer survivors and caregivers, strategies to integrate psychosocial care, like the introduction of survivorship care plans or increased use of patient-reported outcomes, should be explored in the future

    Shining light on the histamine H2 receptor: Synthesis of carbamoylguanidine-type agonists as a pharmacological tool to study internalization

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    So far, only little is known about the internalization process of the histamine H-2 receptor (H2R). One promising approach to study such dynamic processes is the use of agonistic fluorescent ligands. Therefore, a series of carbamoylguanidine-type H2R agonists containing various fluorophores, heterocycles, and linkers (28-40) was synthesized. The ligands were pharmacologically characterized in several binding and functional assays. These studies revealed a significantly biased efficacy (Emax) for some of the compounds, e.g. 32: whereas 32 acted as strong partial (E-max: 0.77, mini-Gs recruitment) or full agonist (E-max: 1.04, [35S]GTP.S binding) with respect to G protein activation, it was only a weak partial agonist regarding beta-arrestin1/2 recruitment (E-max: 0.09-0.12) and failed to promote H2R internalization (confocal microscopy). On the other hand, H2R internalization was observed for compounds that exhibited moderate agonistic activity in the beta-arrestin1/2 pathways (E-max >= 22). The presented differently-biased fluorescent ligands are versatile molecular tools for future H2R studies on receptor trafficking and internalization e.g. using fluorescence microscopy

    The roseoflavin producer Streptomyces davaonensis has a high catalytic capacity and specific genetic adaptations with regard to the biosynthesis of riboflavin.

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    Kissling L, Schneider C, Seibel K, et al. The roseoflavin producer Streptomyces davaonensis has a high catalytic capacity and specific genetic adaptations with regard to the biosynthesis of riboflavin. Environmental microbiology. 2020.The bacterium Streptomyces davaonensis synthesizes the antibiotic roseoflavin in the stationary phase of growth. The starting point for roseoflavin biosynthesis is riboflavin (vitamin B2 ) and four enzymes (RibC, RosB, RosA and RosC) are necessary to convert a vitamin (riboflavin) into a potent, broad-spectrum antibiotic (roseoflavin). In S. davaonensis seven enzymatic functions are required to synthesize the roseoflavin precursor riboflavin from the central building blocks GTP and ribulose 5-phosphate. When compared to other bacterial and in particular Streptomyces genomes the S. davaonensis genome contains an unusual high number (21) of putative riboflavin biosynthetic genes (rib genes), including a rib gene encoding an additional riboflavin synthase originating from an Archaeon. We show by complementation analyses and enzyme assays that 17 out of these 21 putative rib genes indeed encode for riboflavin biosynthetic enzymes. Biochemical analyses of selected enzymes support this finding. Transcriptome analyses show that all of the rib genes are expressed either in the exponential or in the stationary phase of growth and thus do not represent silent genes. We conclude that the Rib enzymes produced in the stationary phase represent a physiological adaptation to support roseoflavin biosynthesis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved
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