57 research outputs found

    CGEF-1 regulates mTORC1 signaling during adult longevity and stress response in

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    The mechanistic target of rapamycin (mTOR) kinase is central to metabolism and growth, and has a conserved role in aging. mTOR functions in two complexes, mTORC1 and mTORC2. In diverse eukaryotes, inhibition of mTORC1 signaling increases lifespan. mTORC1 transduces anabolic signals to stimulate protein synthesis and inhibits autophagy. In this study, we demonstrate that CGEF-1, theC. eleganshomolog of the human guanine nucleotide exchange factor Dbl, is a novel binding partner of RHEB-1 and activator of mTORC1 signaling inC. elegans.cgef-1mutants display prolonged lifespan and enhanced stress resistance. The transcription factors DAF-16/FoxO and SKN-1/Nrf are required for increased longevity and stress tolerance, and induce protective gene expression incgef-1mutants. Genetic evidence indicates thatcgef-1functions in the same pathway withrheb-1, the mTOR kinaselet-363, anddaf-15/Raptor. Whencgef-1is inactivated, phosphorylation of 4E-BP, a central mTORC1 substrate for protein translation is reduced inC. elegans. Moreover, autophagy is increased uponcgef-1and mTORC1 inhibition. In addition, we show that in human cells Dbl associates with Rheb and stimulates mTORC1 downstream targets for protein synthesis suggesting that the function of CGEF-1/Dbl in the mTORC1 signaling pathway is evolutionarily conserved. These findings have important implications for mTOR functions and signaling mechanisms in aging and age-related diseases

    SCD5 Regulation by VHL Affects Cell Proliferation and Lipid Homeostasis in ccRCC

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    Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of renal cancer, and inactivation of the VHL tumor suppressor gene is found in almost all cases of hereditary and sporadic ccRCCs. CcRCC is associated with the reprogramming of fatty acid metabolism, and stearoyl-CoA desaturases (SCDs) are the main enzymes controlling fatty acid composition in cells. In this study, we report that mRNA and protein expression of the stearoyl-CoA desaturase SCD5 is downregulated in VHL-deficient cell lines. Similarly, in C. elegans vhl-1 mutants, FAT-7/SCD5 activity is repressed, supporting an evolutionary conservation. SCD5 regulation by VHL depends on HIF, and loss of SCD5 promotes cell proliferation and a metabolic shift towards ceramide production. In summary, we identify a novel regulatory function of VHL in relation to SCD5 and fatty acid metabolism, and propose a new mechanism of how loss of VHL may contribute to ccRCC tumor formation and progression

    Differential prognostic utility of adiposity measures in chronic kidney disease

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    Objective Adipose tissue contributes to adverse outcomes in chronic kidney disease (CKD), but there is uncertainty regarding the prognostic relevance of different adiposity measures. We analyzed the associations of neck circumference (NC), waist circumference (WC), and body mass index (BMI) with clinical outcomes in patients with mild to severe CKD. Methods The German Chronic Kidney Disease (GCKD) study is a prospective cohort study, which enrolled Caucasian adults with mild to severe CKD, defined as estimated glomerular filtration rate (eGFR): 30–60 mL/min/1.73 m2, or >60 mL/min/1.73 m2 in the presence of overt proteinuria. Associations of NC, WC and BMI with all-cause death, major cardiovascular events (MACE: a composite of non-fatal stroke, non-fatal myocardial infarction, peripheral artery disease intervention, and cardiovascular death), kidney failure (a composite of dialysis or transplantation) were analyzed using multivariable Cox proportional hazards regression models adjusted for confounders and the Akaike information criteria (AIC) were calculated. Models included sex interactions with adiposity measures. Results A total of 4537 participants (59% male) were included in the analysis. During a 6.5-year follow-up, 339 participants died, 510 experienced MACE, and 341 developed kidney failure. In fully adjusted models, NC was associated with all-cause death in women (HR 1.080 per cm; 95% CI 1.009–1.155), but not in men. Irrespective of sex, WC was associated with all-cause death (HR 1.014 per cm; 95% CI 1.005–1.038). NC and WC showed no association with MACE or kidney failure. BMI was not associated with any of the analyzed outcomes. Models of all-cause death including WC offered the best (lowest) AIC. Conclusion In Caucasian patients with mild to severe CKD, higher NC (in women) and WC were significantly associated with increased risk of death from any cause, but BMI was not

    Earth as a Tool for Astrobiology—A European Perspective

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    The Efficacy of Short-Term Psycho-Oncological Interventions for Women with Gynaecological Cancer: A Randomized Study

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    Objectives: We aimed to examine the efficacy of two psycho-oncological interventions in anxiety, depression, and self-perceived as well as physiological stress in inpatients with gynaecological cancer. Methods: Forty-five women were included in the trial. Thirty-five were categorized as being at high risk of anxiety and depression, and were randomized to either a single psycho-oncological therapy session or a single-session relaxation intervention. Results: A significant decrease in anxiety [mean (tâ‚€) = 12, mean (t1) = 7.47, p = 0.001] and depression [mean (tâ‚€) = 9.71, mean (t1) = 6.35, p 1) = 8.22, p = 0.003], whereas depression did not. A comparative analysis of both interventions showed a trend in favour of psycho-oncological therapy for the treatment of depression (F = 3.3, p = 0.078). However, self-reported stress (p = 0.031) and different objective stress parameters only significantly decreased in the relaxation group. Conclusions: Psycho-oncological interventions should represent an essential part of interdisciplinary care for gynaecological cancer patients. Both types of intervention may reduce anxiety. However, the single psycho-oncological therapy session might be slightly more effective in treating depression, whereas the single-session relaxation intervention seems to have a stronger effect on physiological stress parameters.Peer Reviewe

    Functional and spatial analysis of C. elegans SYG-1 and SYG-2, orthologs of the Neph/nephrin cell adhesion module directing selective synaptogenesis.

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    The assembly of specific synaptic connections represents a prime example of cellular recognition. Members of the Ig superfamily are among the most ancient proteins represented in the genomes of both mammalian and invertebrate organisms, where they constitute a trans-synaptic adhesion system. The correct connectivity patterns of the highly conserved immunoglobulin superfamily proteins nephrin and Neph1 are crucial for the assembly of functional neuronal circuits and the formation of the kidney slit diaphragm, a synapse-like structure forming the filtration barrier. Here, we utilize the nematode C. elegans model for studying the requirements of synaptic specificity mediated by nephrin-Neph proteins. In C. elegans, the nephrin/Neph1 orthologs SYG-2 and SYG-1 form intercellular contacts strictly in trans between epithelial guidepost cells and neurons specifying the localization of synapses. We demonstrate a functional conservation between mammalian nephrin and SYG-2. Expression of nephrin effectively compensated loss of syg-2 function in C. elegans and restored defective synaptic connectivity further establishing the C. elegans system as a valuable model for slit diaphragm proteins. Next, we investigated the effect of SYG-1 and SYG-2 trans homodimerization respectively. Strikingly, synapse assembly could be induced by homophilic SYG-1 but not SYG-2 binding indicating a critical role of SYG-1 intracellular signalling for morphogenetic events and pointing toward the dynamic and stochastic nature of extra- and intracellular nephrin-Neph interactions to generate reproducible patterns of synaptic connectivity

    DOI:10.1068/htwu492 Thermal conductivity of food materials at elevated temperatures

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    Abstract. In order to expand the available information on thermal conductivity of foods, within the framework of COST Action 93, a collaborative study was organised. In the first step, typical food components (apple pulp, meat, olive oil, sodium caseinate, starch, tomato paste) were used as standards for measurements, and in the second step, standardised glass beads were used for calibration experiments. The results have demonstrated that it is rather difficult to come up with reliable accurate information. Problems are to some extent related to the measuring procedures, in particular the variability in contact between heat source and test material and/or contact between test material and thermal sensors. Further problems arise for products which are not stable throughout the duration of the experiment.

    Treating C3 glomerulopathy with eculizumab

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    Abstract Background C3 glomerulopathy (C3G) is a rare, but severe glomerular disease with grim prognosis. The complex pathogenesis is just unfolding, and involves acquired as well as inherited dysregulation of the alternative pathway of the complement cascade. Currently, there is no established therapy. Treatment with the C5 complement inhibitor eculizumab may be a therapeutic option. However, due to rarity of the disease, parameters predicting treatment response remain largely unknown. Methods Seven patients with C3G (five with C3 glomerulonephritis and two with dense deposit disease) were treated with eculizumab. Subjects underwent biopsy before enrollment. The histopathology, clinical data, and response to eculizumab treatment were analyzed. The key parameters to determine outcome were changes of serum creatinine and urinary protein over time. Results After treatment with eculizumab, four subjects showed significantly improved or stable renal function and urinary protein. A positive response occurred between 2 weeks and 6 months after therapy initiation. One subject (with allograft recurrent C3 glomerulonephritis) initially showed a positive response, but relapsed when eculizumab was discontinued, and did not respond after re-initiation of treatment. Two subjects showed impaired renal function and increasing urinary protein despite therapy with eculizumab. Conclusions Eculizumab may be a therapeutic option for a subset of C3G patients. The response to eculizumab is heterogeneous, and early as well as continuous treatment may be necessary to prevent disease progression. These findings emphasize the need for studies identifying genetic and functional complement abnormalities that may help to guide eculizumab treatment and predict response

    Comparison of different anticoagulation strategies for renal replacement therapy in critically ill patients with COVID-19: a cohort study

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    Background!#!Critically ill coronavirus disease 2019 (COVID-19) patients have a high risk of acute kidney injury (AKI) that requires renal replacement therapy (RRT). A state of hypercoagulability reduces circuit life spans. To maintain circuit patency and therapeutic efficiency, an optimized anticoagulation strategy is needed. This study investigates whether alternative anticoagulation strategies for RRT during COVID-19 are superior to administration of unfractionated heparin (UFH).!##!Methods!#!Retrospective cohort study on 71 critically ill COVID-19 patients (≥18 years), admitted to intensive care units at a tertiary health care facility in the southwestern part of Germany between February 26 and May 21, 2020. We collected data on the disease course, AKI, RRT, and thromboembolic events. Four different anticoagulatory regimens were administered. Anticoagulation during continuous veno-venous hemodialysis (CVVHD) was performed with UFH or citrate. Anticoagulation during sustained low-efficiency daily dialysis (SLEDD) was performed with UFH, argatroban, or low molecular weight heparin (LMWH). Primary outcome is the effect of the anticoagulation regimen on mean treatment times of RRT.!##!Results!#!In patients receiving CVVHD, mean treatment time in the UFH group was 21.3 h (SEM: ±5.6 h), in the citrate group 45.6 h (SEM: ±2.7 h). Citrate anticoagulation significantly prolonged treatment times by 24.4 h (P = .001). In patients receiving SLEDD, mean treatment time with UFH was 8.1 h (SEM: ±1.3 h), with argatroban 8.0 h (SEM: ±0.9 h), and with LMWH 11.8 h (SEM: ±0.5 h). LMWH significantly prolonged treatment times by 3.7 h (P = .008) and 3.8 h (P = .002), respectively.!##!Conclusions!#!UFH fails to prevent early clotting events in the dialysis circuit during COVID-19. For patients, who do not require effective systemic anticoagulation, regional citrate dialysis is the most effective strategy. For patients, who require effective systemic anticoagulation, the usage of LMWH results in the longest circuit life spans. The proposed anticoagulatory strategies are safe, can easily be monitored, and allow an individualized treatment
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