30 research outputs found
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Accelerated epigenetic aging and DNA methylation alterations in Berardinelli-Seip congenital lipodystrophy
Berardinelli–Seip Congenital Lipodystrophy type 2 (CGL2) is a very rare human genetic disorder with potential significance to the understanding of the pathobiology of aging. CGL2 patients display characteristic progeroid features and suffer from type 2 diabetes, insulin resistance, and fatty liver. In this study, we profiled genome-wide DNA methylation levels in CGL2 patients with BSCL2 mutations to study epigenetic age acceleration and DNA methylation alterations. This analysis revealed significant age acceleration in blood DNA of CGL2 patients using both first and second generation epigenetic clocks. We also observed a shortened lifespan of C. elegans following knockdown of the BSCL2 homolog seip-1 on a daf-16/Foxo mutant background. DNA methylation analysis revealed significant differentially methylated sites enriched for lyase activity, kinase regulator activity, protein kinase regulator activity, and kinase activator activity. We could also observe significant hypomethylation in the promoter of the Dual Specificity Phosphatase 22 (DUSP22) gene when comparing CGL2 patients vs controls. We conclude that in line with the observed progeroid features, CGL2 patients exhibit significant epigenetic age acceleration and DNA methylation alterations that might affect pathways/genes of potential relevance to the disease
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E4 ligase–specific ubiquitination hubs coordinate DNA double-strand-break repair and apoptosis
Multiple protein ubiquitination events at DNA double-strand breaks (DSBs) regulate damage recognition, signaling and repair. It has remained poorly understood how the repair process of DSBs is coordinated with the apoptotic response. Here, we identified the E4 ubiquitin ligase UFD-2 as a mediator of DNA-damage-induced apoptosis in a genetic screen in Caenorhabditis elegans. We found that, after initiation of homologous recombination by RAD-51, UFD-2 forms foci that contain substrate-processivity factors including the ubiquitin-selective segregase CDC-48 (p97), the deubiquitination enzyme ATX-3 (Ataxin-3) and the proteasome. In the absence of UFD-2, RAD-51 foci persist, and DNA damage-induced apoptosis is prevented. In contrast, UFD-2 foci are retained until recombination intermediates are removed by the Holliday-junction-processing enzymes GEN-1, MUS-81 or XPF-1. Formation of UFD-2 foci also requires proapoptotic CEP-1 (p53) signaling. Our findings establish a central role of UFD-2 in the coordination between the DNA-repair process and the apoptotic response
Both the Caspase CSP-1 and a Caspase-Independent Pathway Promote Programmed Cell Death in Parallel to the Canonical Pathway for Apoptosis in Caenorhabditis elegans
Caspases are cysteine proteases that can drive apoptosis in metazoans and have critical functions in the elimination of cells during development, the maintenance of tissue homeostasis, and responses to cellular damage. Although a growing body of research suggests that programmed cell death can occur in the absence of caspases, mammalian studies of caspase-independent apoptosis are confounded by the existence of at least seven caspase homologs that can function redundantly to promote cell death. Caspase-independent programmed cell death is also thought to occur in the invertebrate nematode Caenorhabditis elegans. The C. elegans genome contains four caspase genes (ced-3, csp-1, csp-2, and csp-3), of which only ced-3 has been demonstrated to promote apoptosis. Here, we show that CSP-1 is a pro-apoptotic caspase that promotes programmed cell death in a subset of cells fated to die during C. elegans embryogenesis. csp-1 is expressed robustly in late pachytene nuclei of the germline and is required maternally for its role in embryonic programmed cell deaths. Unlike CED-3, CSP-1 is not regulated by the APAF-1 homolog CED-4 or the BCL-2 homolog CED-9, revealing that csp-1 functions independently of the canonical genetic pathway for apoptosis. Previously we demonstrated that embryos lacking all four caspases can eliminate cells through an extrusion mechanism and that these cells are apoptotic. Extruded cells differ from cells that normally undergo programmed cell death not only by being extruded but also by not being engulfed by neighboring cells. In this study, we identify in csp-3; csp-1; csp-2 ced-3 quadruple mutants apoptotic cell corpses that fully resemble wild-type cell corpses: these caspase-deficient cell corpses are morphologically apoptotic, are not extruded, and are internalized by engulfing cells. We conclude that both caspase-dependent and caspase-independent pathways promote apoptotic programmed cell death and the phagocytosis of cell corpses in parallel to the canonical apoptosis pathway involving CED-3 activation.Howard Hughes Medical InstituteDamon Runyon Cancer Research FoundationCharles A. King Trus
C. elegans EIF-3.K Promotes Programmed Cell Death through CED-3 Caspase
Programmed cell death (apoptosis) is essential for the development and homeostasis of metazoans. The central step in the execution of programmed cell death is the activation of caspases. In C. elegans, the core cell death regulators EGL-1(a BH3 domain-containing protein), CED-9 (Bcl-2), and CED-4 (Apaf-1) act in an inhibitory cascade to activate the CED-3 caspase. Here we have identified an additional component eif-3.K (eukaryotic translation initiation factor 3 subunit k) that acts upstream of ced-3 to promote programmed cell death. The loss of eif-3.K reduced cell deaths in both somatic and germ cells, whereas the overexpression of eif-3.K resulted in a slight but significant increase in cell death. Using a cell-specific promoter, we show that eif-3.K promotes cell death in a cell-autonomous manner. In addition, the loss of eif-3.K significantly suppressed cell death-induced through the overexpression of ced-4, but not ced-3, indicating a distinct requirement for eif-3.K in apoptosis. Reciprocally, a loss of ced-3 suppressed cell death induced by the overexpression of eif-3.K. These results indicate that eif-3.K requires ced-3 to promote programmed cell death and that eif-3.K acts upstream of ced-3 to promote this process. The EIF-3.K protein is ubiquitously expressed in embryos and larvae and localizes to the cytoplasm. A structure-function analysis revealed that the 61 amino acid long WH domain of EIF-3.K, potentially involved in protein-DNA/RNA interactions, is both necessary and sufficient for the cell death-promoting activity of EIF-3.K. Because human eIF3k was able to partially substitute for C. elegans eif-3.K in the promotion of cell death, this WH domain-dependent EIF-3.K-mediated cell death process has potentially been conserved throughout evolution
Концептуальная модель инновационного усовершенствования сферы услуг для неправительственного высшего образования
Using a qualitative method, this study developed a model for service innovation excellence for non-governmental higher education. Analysis of qualitative data showed that five major themes including innovation leadership, innovation strategies, innovation process, innovation resources, competencies and capabilities of faculty members form innovation excellence of non-governmental higher education. The most important strategies identified for achieving innovation in higher education institutions included innovation creation, benchmarking, expert recruitment, and joint venture and innovation absorption. In addition, task competency, learning ability, research skills, innovation intention, information literacy, creative thinking and teamwork skills are the most important competencies and capabilities identified for realization of innovation in higher education institutions.Використовуючи якісний метод, у статті розроблена модель інноваційного удосконалення в сфері послуг для недержавної вищої освіти. Аналіз якісних даних показав, що п'ять основних напрямків, включаючи інноваційне лідерство, інноваційні стратегії, інноваційний процес, інноваційні ресурси, компетенції та можливості викладачів, формують інноваційне удосконалення недержавної вищої освіти. Найбільш важливі стратегії, які були визначені для досягнення інновацій у вищих навчальних закладах, включають створення інновацій, порівняльний аналіз, підбір експертів, спільне підприємство та інноваційне поглинання. Крім того, компетенція завдання, здатність до навчання, дослідницькі навички, прагнення до інновацій, інформаційна грамотність, творче мислення і навички командної роботи є найбільш важливими компетенціями і можливостями, виявленими для реалізації інновацій у вищих навчальних закладах.Используя качественный метод, в статье разработана модель инновационного усовершенствования в сфере услуг для негосударственного высшего образования. Анализ качественных данных показал, что пять основных направлений, включая инновационное лидерство, инновационные стратегии, инновационный процесс, инновационные ресурсы, компетенции и возможности преподавателей, формируют инновационное усовершенствование негосударственного высшего образования. Наиболее важные стратегии, которые были определены для достижения инноваций в высших учебных заведениях, включают создание инноваций, сравнительный анализ, подбор экспертов, совместное предприятие и инновационное поглощение. Кроме того, компетенция задачи, способность к обучению, исследовательские навыки, стремление к инновациям, информационная грамотность, творческое мышление и навыки командной работы являются наиболее важными компетенциями и возможностями, выявленными для реализации инноваций в высших учебных заведениях
Концептуальная модель инновационного усовершенствования сферы услуг для неправительственного высшего образования
Using a qualitative method, this study developed a model for service innovation excellence for non-governmental higher education. Analysis of qualitative data showed that five major themes including innovation leadership, innovation strategies, innovation process, innovation resources, competencies and capabilities of faculty members form innovation excellence of non-governmental higher education. The most important strategies identified for achieving innovation in higher education institutions included innovation creation, benchmarking, expert recruitment, and joint venture and innovation absorption. In addition, task competency, learning ability, research skills, innovation intention, information literacy, creative thinking and teamwork skills are the most important competencies and capabilities identified for realization of innovation in higher education institutions.Використовуючи якісний метод, у статті розроблена модель інноваційного удосконалення в сфері послуг для недержавної вищої освіти. Аналіз якісних даних показав, що п'ять основних напрямків, включаючи інноваційне лідерство, інноваційні стратегії, інноваційний процес, інноваційні ресурси, компетенції та можливості викладачів, формують інноваційне удосконалення недержавної вищої освіти. Найбільш важливі стратегії, які були визначені для досягнення інновацій у вищих навчальних закладах, включають створення інновацій, порівняльний аналіз, підбір експертів, спільне підприємство та інноваційне поглинання. Крім того, компетенція завдання, здатність до навчання, дослідницькі навички, прагнення до інновацій, інформаційна грамотність, творче мислення і навички командної роботи є найбільш важливими компетенціями і можливостями, виявленими для реалізації інновацій у вищих навчальних закладах.Используя качественный метод, в статье разработана модель инновационного усовершенствования в сфере услуг для негосударственного высшего образования. Анализ качественных данных показал, что пять основных направлений, включая инновационное лидерство, инновационные стратегии, инновационный процесс, инновационные ресурсы, компетенции и возможности преподавателей, формируют инновационное усовершенствование негосударственного высшего образования. Наиболее важные стратегии, которые были определены для достижения инноваций в высших учебных заведениях, включают создание инноваций, сравнительный анализ, подбор экспертов, совместное предприятие и инновационное поглощение. Кроме того, компетенция задачи, способность к обучению, исследовательские навыки, стремление к инновациям, информационная грамотность, творческое мышление и навыки командной работы являются наиболее важными компетенциями и возможностями, выявленными для реализации инноваций в высших учебных заведениях
The Opportunistic Pathogen Serratia marcescens Utilizes Type VI Secretion To Target Bacterial Competitors
The type VI secretion system (T6SS) is the most recently described and least understood of the protein secretion systems of Gram-negative bacteria. It is widely distributed and has been implicated in the virulence of various pathogens, but its mechanism and exact mode of action remain to be defined. Additionally there have been several very recent reports that some T6SSs can target bacteria rather than eukaryotic cells. Serratia marcescens is an opportunistic enteric pathogen, a class of bacteria responsible for a significant proportion of hospital-acquired infections. We describe the identification of a functional T6SS in S. marcescens strain Db10, the first report of type VI secretion by an opportunist enteric bacterium. The T6SS of S. marcescens Db10 is active, with secretion of Hcp to the culture medium readily detected, and is expressed constitutively under normal growth conditions from a large transcriptional unit. Expression of the T6SS genes did not appear to be dependent on the integrity of the T6SS. The S. marcescens Db10 T6SS is not required for virulence in three nonmammalian virulence models. It does, however, exhibit dramatic antibacterial killing activity against several other bacterial species and is required for S. marcescens to persist in a mixed culture with another opportunist pathogen, Enterobacter cloacae. Importantly, this antibacterial killing activity is highly strain specific, with the S. marcescens Db10 T6SS being highly effective against another strain of S. marcescens with a very similar and active T6SS. We conclude that type VI secretion plays a crucial role in the competitiveness, and thus indirectly the virulence, of S. marcescens and other opportunistic bacterial pathogens
Dynamic SUMO modification regulates mitotic chromosome assembly and cell cycle progression in Caenorhabditis elegans
The small ubiquitin-like modifier (SUMO), initially characterized as a suppressor of a mutation in the gene encoding the centromeric protein MIF2, is involved in many aspects of cell cycle regulation. The dynamics of conjugation and deconjugation and the role of SUMO during the cell cycle remain unexplored. Here we used Caenorhabditis elegans to establish the contribution of SUMO to a timely and accurate cell division. Chromatin-associated SUMO conjugates increase during metaphase but decrease rapidly during anaphase. Accumulation of SUMO conjugates on the metaphase plate and proper chromosome alignment depend on the SUMO E2 conjugating enzyme UBC-9 and SUMO E3 ligase PIAS(GEI-17). Deconjugation is achieved by the SUMO protease ULP-4 and is crucial for correct progression through the cell cycle. Moreover, ULP-4 is necessary for Aurora B(AIR-2) extraction from chromatin and relocation to the spindle mid-zone. Our results show that dynamic SUMO conjugation plays a role in cell cycle progression