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1.
Genes Dev ; 36(7-8): 495-510, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35483740

RESUMEN

The identity of human protein-coding genes is well known, yet our in-depth knowledge of their molecular functions and domain architecture remains limited by shortcomings in homology-based predictions and experimental approaches focused on whole-gene depletion. To bridge this knowledge gap, we developed a method that leverages CRISPR-Cas9-induced mutations across protein-coding genes for the a priori identification of functional regions at the sequence level. As a test case, we applied this method to 48 human mitotic genes, revealing hundreds of regions required for cell proliferation, including domains that were experimentally characterized, ones that were predicted based on homology, and novel ones. We validated screen outcomes for 15 regions, including amino acids 387-402 of Mad1, which were previously uncharacterized but contribute to Mad1 kinetochore localization and chromosome segregation fidelity. Altogether, we demonstrate that CRISPR-Cas9-based tiling mutagenesis identifies key functional domains in protein-coding genes de novo, which elucidates separation of function mutants and allows functional annotation across the human proteome.


Asunto(s)
Sistemas CRISPR-Cas , Sistemas CRISPR-Cas/genética , Humanos , Mutagénesis
2.
Development ; 150(18)2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37665168

RESUMEN

Chicken embryos are a powerful and widely used animal model in developmental biology studies. Since the development of CRISPR technology, gene-edited chickens have been generated by transferring primordial germ cells (PGCs) into recipients after genetic modifications. However, low inheritance caused by competition between host germ cells and the transferred cells is a common complication and greatly reduces production efficiency. Here, we generated a gene-edited chicken, in which germ cells can be ablated in a drug-dependent manner, as recipients for gene-edited PGC transfer. We used the nitroreductase/metronidazole (NTR/Mtz) system for cell ablation, in which nitroreductase produces cytotoxic alkylating agents from administered metronidazole, causing cell apoptosis. The chicken Vasa homolog (CVH) gene locus was used to drive the expression of the nitroreductase gene in a germ cell-specific manner. In addition, a fluorescent protein gene, mCherry, was also placed in the CVH locus to visualize the PGCs. We named this system 'germ cell-specific autonomous removal induction' (gSAMURAI). gSAMURAI chickens will be an ideal recipient to produce offspring derived from transplanted exogenous germ cells.


Asunto(s)
Pollos , Metronidazol , Embrión de Pollo , Animales , Pollos/genética , Células Germinativas/metabolismo , Nitrorreductasas/metabolismo
3.
Development ; 150(14)2023 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-37485540

RESUMEN

Accurate chromosome segregation, monitored by the spindle assembly checkpoint (SAC), is crucial for the production of euploid cells. Previous in vitro studies by us and others showed that Mad2, a core member of the SAC, performs a checkpoint function in oocyte meiosis. Here, through an oocyte-specific knockout approach in mouse, we reconfirmed that Mad2-deficient oocytes exhibit an accelerated metaphase-to-anaphase transition caused by premature degradation of securin and cyclin B1 and subsequent activation of separase in meiosis I. However, it was surprising that the knockout mice were completely fertile and the resulting oocytes were euploid. In the absence of Mad2, other SAC proteins, including BubR1, Bub3 and Mad1, were normally recruited to the kinetochores, which likely explains the balanced chromosome separation. Further studies showed that the chromosome separation in Mad2-null oocytes was particularly sensitive to environmental changes and, when matured in vitro, showed chromosome misalignment, lagging chromosomes, and aneuploidy with premature separation of sister chromatids, which was exacerbated at a lower temperature. We reveal for the first time that Mad2 is dispensable for proper chromosome segregation but acts to mitigate environmental stress in meiotic oocytes.


Asunto(s)
Proteínas de Ciclo Celular , Huso Acromático , Animales , Ratones , Proteínas de Ciclo Celular/metabolismo , Huso Acromático/metabolismo , Proteínas Mad2/genética , Proteínas Mad2/metabolismo , Segregación Cromosómica/genética , Oocitos/metabolismo , Cinetocoros/metabolismo , Meiosis/genética
4.
EMBO Rep ; 25(6): 2743-2772, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38806674

RESUMEN

Interference with microtubule dynamics in mitosis activates the spindle assembly checkpoint (SAC) to prevent chromosome segregation errors. The SAC induces mitotic arrest by inhibiting the anaphase-promoting complex (APC) via the mitotic checkpoint complex (MCC). The MCC component MAD2 neutralizes the critical APC cofactor, CDC20, preventing exit from mitosis. Extended mitotic arrest can promote mitochondrial apoptosis and caspase activation. However, the impact of mitotic cell death on tissue homeostasis in vivo is ill-defined. By conditional MAD2 overexpression, we observe that chronic SAC activation triggers bone marrow aplasia and intestinal atrophy in mice. While myelosuppression can be compensated for, gastrointestinal atrophy is detrimental. Remarkably, deletion of pro-apoptotic Bim/Bcl2l11 prevents gastrointestinal syndrome, while neither loss of Noxa/Pmaip or co-deletion of Bid and Puma/Bbc3 has such a protective effect, identifying BIM as rate-limiting apoptosis effector in mitotic cell death of the gastrointestinal epithelium. In contrast, only overexpression of anti-apoptotic BCL2, but none of the BH3-only protein deficiencies mentioned above, can mitigate myelosuppression. Our findings highlight tissue and cell-type-specific survival dependencies in response to SAC perturbation in vivo.


Asunto(s)
Proteínas Reguladoras de la Apoptosis , Apoptosis , Proteína 11 Similar a Bcl2 , Puntos de Control de la Fase M del Ciclo Celular , Proteínas Mad2 , Proteínas Proto-Oncogénicas c-bcl-2 , Animales , Proteína 11 Similar a Bcl2/metabolismo , Proteína 11 Similar a Bcl2/genética , Ratones , Proteínas Mad2/metabolismo , Proteínas Mad2/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Atrofia , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/genética , Mitosis , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/metabolismo , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/genética , Proteínas Cdc20/metabolismo , Proteínas Cdc20/genética , Médula Ósea/patología , Médula Ósea/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Proteínas Supresoras de Tumor
5.
Mol Cell ; 70(4): 628-638.e5, 2018 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-29775579

RESUMEN

Cell survival to replication stress depends on the activation of the Mec1ATR-Rad53 checkpoint response that protects the integrity of stalled forks and controls the origin firing program. Here we found that Mad2, a member of the spindle assembly checkpoint (SAC), contributes to efficient origin firing and to cell survival in response to replication stress. We show that Rad53 and Mad2 promote S-phase cyclin expression through different mechanisms: while Rad53 influences Clb5,6 degradation, Mad2 promotes their protein synthesis. We found that Mad2 co-sediments with polysomes and modulates the association of the translation inhibitor Caf204E-BP with the translation machinery and the initiation factor eIF4E. This Mad2-dependent translational regulatory process does not depend on other SAC proteins. Altogether our observations indicate that Mad2 has an additional function outside of mitosis to control DNA synthesis and collaborates with the Mec1-Rad53 regulatory axis to allow cell survival in response to replication stress.


Asunto(s)
Ciclinas/genética , Replicación del ADN , Proteínas Mad2/metabolismo , Mitosis , Biosíntesis de Proteínas , Fase S , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Quinasa de Punto de Control 2/genética , Quinasa de Punto de Control 2/metabolismo , Ciclina B/genética , Ciclina B/metabolismo , Ciclinas/metabolismo , Proteínas Mad2/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Origen de Réplica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Proteínas de Saccharomyces cerevisiae/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
6.
Proteins ; 2024 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-38221646

RESUMEN

The spindle checkpoint complex is a key surveillance mechanism in cell division that prevents premature separation of sister chromatids. Mad2 is an integral component of this spindle checkpoint complex that recognizes cognate substrates such as Mad1 and Cdc20 in its closed (C-Mad2) conformation by fastening a "seatbelt" around short peptide regions that bind to the substrate recognition site. Mad2 is also a metamorphic protein that adopts not only the fold found in C-Mad2, but also a structurally distinct open conformation (O-Mad2) which is incapable of binding substrates. Here, we show using chemical exchange saturation transfer (CEST) and relaxation dispersion (CPMG) NMR experiments that Mad2 transiently populates three other higher free energy states with millisecond lifetimes, two in equilibrium with C-Mad2 (E1 and E2) and one with O-Mad2 (E3). E1 is a mimic of substrate-bound C-Mad2 in which the N-terminus of one C-Mad2 molecule inserts into the seatbelt region of a second molecule of C-Mad2, providing a potential pathway for autoinhibition of C-Mad2. E2 is the "unbuckled" conformation of C-Mad2 that facilitates the triage of molecules along competing fold-switching and substrate binding pathways. The E3 conformation that coexists with O-Mad2 shows fluctuations at a hydrophobic lock that is required for stabilizing the O-Mad2 fold and we hypothesize that E3 represents an early intermediate on-pathway towards conversion to C-Mad2. Collectively, the NMR data highlight the rugged free energy landscape of Mad2 with multiple low-lying intermediates that interlink substrate-binding and fold-switching, and also emphasize the role of molecular dynamics in its function.

7.
EMBO J ; 39(12): e103180, 2020 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-32202322

RESUMEN

Cyclin B:CDK1 is the master kinase regulator of mitosis. We show here that, in addition to its kinase functions, mammalian Cyclin B also scaffolds a localised signalling pathway to help preserve genome stability. Cyclin B1 localises to an expanded region of the outer kinetochore, known as the corona, where it scaffolds the spindle assembly checkpoint (SAC) machinery by binding directly to MAD1. In vitro reconstitutions map the key binding interface to a few acidic residues in the N-terminal region of MAD1, and point mutations in this sequence abolish MAD1 corona localisation and weaken the SAC. Therefore, Cyclin B1 is the long-sought-after scaffold that links MAD1 to the corona, and this specific pool of MAD1 is needed to generate a robust SAC response. Robustness arises because Cyclin B1:MAD1 localisation loses dependence on MPS1 kinase after the corona has been established, ensuring that corona-localised MAD1 can still be phosphorylated when MPS1 activity is low. Therefore, this study explains how corona-MAD1 generates a robust SAC signal, and it reveals a scaffolding role for the key mitotic kinase, Cyclin B1:CDK1, which ultimately helps to inhibit its own degradation.


Asunto(s)
Puntos de Control del Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Ciclina B1/metabolismo , Cinetocoros/metabolismo , Mitosis , Proteína Quinasa CDC2/genética , Proteína Quinasa CDC2/metabolismo , Proteínas de Ciclo Celular/genética , Ciclina B1/genética , Células HeLa , Humanos , Mutación Puntual , Dominios Proteicos
8.
Plant Biotechnol J ; 22(2): 401-412, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37864303

RESUMEN

The ErCas12a nuclease, also known as MAD7, is part of a CRISPR/Cas system from Eubacterium rectale and distantly related to Cas12a nucleases. As it shares only 31% sequence homology with the commonly used AsCas12a, its intellectual property may not be covered by the granted patent rights for Cas12a nucleases. Thus, ErCas12a became an attractive alternative for practical applications. However, the editing efficiency of ErCas12a is strongly target sequence- and temperature-dependent. Therefore, optimization of the enzyme activity through protein engineering is especially attractive for its application in plants, as they are cultivated at lower temperatures. Based on the knowledge obtained from the optimization of Cas12a nucleases, we opted to improve the gene editing efficiency of ErCas12a by introducing analogous amino acid exchanges. Interestingly, neither of these mutations analogous to those in the enhanced or Ultra versions of AsCas12a resulted in significant editing enhancement of ErCas12a in Arabidopsis thaliana. However, two different mutations, V156R and K172R, in putative alpha helical structures of the enzyme showed a detectable improvement in editing. By combining these two mutations, we obtained an improved ErCas12a (imErCas12a) variant, showing several-fold increase in activity in comparison to the wild-type enzyme in Arabidopsis. This variant yields strong editing efficiencies at 22 °C which could be further increased by raising the cultivation temperature to 28 °C and even enabled editing of formerly inaccessible targets. Additionally, no enhanced off-site activity was detected. Thus, imErCas12a is an economically attractive and efficient alternative to other CRISPR/Cas systems for plant genome engineering.


Asunto(s)
Arabidopsis , Edición Génica , Arabidopsis/metabolismo , Sistemas CRISPR-Cas/genética , Endonucleasas/genética
9.
EMBO Rep ; 23(6): e54171, 2022 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-35384228

RESUMEN

Accurate mitotic progression relies on the dynamic phosphorylation of multiple substrates by key mitotic kinases. Cyclin-dependent kinase 1 is a master kinase that coordinates mitotic progression and requires its regulatory subunit Cyclin B to ensure full kinase activity and substrate specificity. The function of Cyclin B2, which is a closely related family member of Cyclin B1, remains largely elusive. Here, we show that Mad2 promotes the kinetochore localization of Cyclin B2 and that their interaction at the kinetochores guides accurate chromosome segregation. Our biochemical analyses have characterized the Mad2-Cyclin B2 interaction and delineated a novel Mad2-interacting motif (MIM) on Cyclin B2. The functional importance of the Cyclin B2-Mad2 interaction was demonstrated by real-time imaging in which MIM-deficient mutant Cyclin B2 failed to rescue the chromosomal segregation defects. Taken together, we have delineated a previously undefined function of Cyclin B2 at the kinetochore and have established, in human cells, a mechanism of action by which Mad2 contributes to the spindle checkpoint.


Asunto(s)
Ciclina B2/metabolismo , Cinetocoros , Puntos de Control de la Fase M del Ciclo Celular , Proteínas Mad2/metabolismo , Proteínas de Ciclo Celular/metabolismo , Humanos , Cinetocoros/metabolismo , Mitosis , Huso Acromático/metabolismo
10.
Exp Cell Res ; 429(2): 113672, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37339729

RESUMEN

Heat shock is a physiological and environmental stress that leads to the denaturation and inactivation of cellular proteins and is used in hyperthermia cancer therapy. Previously, we revealed that mild heat shock (42 °C) delays the mitotic progression by activating the spindle assembly checkpoint (SAC). However, it is unclear whether SAC activation is maintained at higher temperatures than 42 °C. Here, we demonstrated that a high temperature of 44 °C just before mitotic entry led to a prolonged mitotic delay in the early phase, which was shortened by the SAC inhibitor, AZ3146, indicating SAC activation. Interestingly, mitotic slippage was observed at 44 °C after a prolonged delay but not at 42 °C heat shock. Furthermore, the multinuclear cells were generated by mitotic slippage in 44 °C-treated cells. Immunofluorescence analysis revealed that heat shock at 44 °C reduces the kinetochore localization of MAD2, which is essential for mitotic checkpoint activation, in nocodazole-arrested mitotic cells. These results indicate that 44 °C heat shock causes SAC inactivation even after full activation of SAC and suggest that decreased localization of MAD2 at the kinetochore is involved in heat shock-induced mitotic slippage, resulting in multinucleation. Since mitotic slippage causes drug resistance and chromosomal instability, we propose that there may be a risk of cancer malignancy when the cells are exposed to high temperatures.


Asunto(s)
Proteínas de Ciclo Celular , Puntos de Control de la Fase M del Ciclo Celular , Humanos , Proteínas de Ciclo Celular/genética , Proteínas Mad2/genética , Proteínas Mad2/metabolismo , Temperatura , Huso Acromático/metabolismo , Respuesta al Choque Térmico , Mitosis
11.
Sleep Breath ; 28(3): 1037-1049, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38180683

RESUMEN

The aim of this systematic review and meta-analysis was to analyze whether or not mandibular advancement devices (MADs) produce changes in blood pressure in patients with obstructive sleep apnea (OSA) in relation to use time and if the device is used at night or day. MATERIALS AND METHOD: A systematic review of the literature and meta-analysis was carried out in accordance with PRISMA guidelines. In the bibliographic search, a total of four databases were consulted: PubMed-Medline, Scopus, Web of Science, and Cochrane. Of the 622 articles initially revealed, 160 duplicates were eliminated. After applying the selection criteria, 17 articles were included for the qualitative analysis and 4 for the meta-analysis. The studies were combined using a random effects model with the inverse method of variance, determining the mean differences in systolic and diastolic pressure before and after treatment using the MAD splint as the effect size. Day/night circadian effect and treatment time were analyzed using meta-regression with a mixed-effects model. RESULTS: MAD treatment was not found to affect diastolic pressure. By combining the four studies with the control group in a meta-analysis (I2 = 75%; z = - 0.15; p-value = 0.882), the mean difference in diastolic pressure between the MAD group and the control group was estimated at - 0.06 (- 0.86; 0.74). The meta-regression also showed no significant effect of day/night (p = 0.560) or treatment time (p = 0.854) on diastolic pressure. When combining the four studies with the control group (I2 = 84%%; z = - 1.47; p-value = 0.142), a non-significant mean difference in systolic pressure between the MAD group and the control group of - 0.99 (- 2.31; 0.33) was estimated in the meta-analysis. However, when assessing the effect of day/night or treatment time on systolic blood pressure using a meta-regression, the latter showed significant covariates that reduce systolic blood pressure values in the model at night (p < 0.001) and in relation to treatment time (p < 0.001). CONCLUSIONS: Only systolic pressure appears to be affected by the use of the MAD in patients with OSA, and this decrease in systolic pressure is greater at night and when treatment time is longer.


Asunto(s)
Presión Sanguínea , Avance Mandibular , Apnea Obstructiva del Sueño , Humanos , Presión Sanguínea/fisiología , Ritmo Circadiano/fisiología , Avance Mandibular/instrumentación , Ferulas Oclusales , Apnea Obstructiva del Sueño/terapia , Apnea Obstructiva del Sueño/fisiopatología
12.
Biochem Genet ; 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38683465

RESUMEN

Ovarian cancer develops insidiously and is frequently diagnosed at advanced stages. Screening for ovarian cancer is an effective strategy for reducing mortality. This study aimed to investigate the molecular mechanisms underlying the development of ovarian cancer and identify novel tumor biomarkers for the diagnosis and prognosis of ovarian cancer. Three databases containing gene expression profiles specific to serous ovarian cancer (GSE18520, GSE12470, and GSE26712) were acquired. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were analyzed for the differentially expressed gene (DEGs). The protein-protein interaction (PPI) network was constructed using the STRING database. The pivotal genes in the PPI network were screened using the Cytoscape software. Survival curve analysis was performed using a Kaplan-Meier Plotter. The cancer genome atlas and Gene Expression Omnibus databases were used to find the relationship between Hub gene and serous ovarian cancer. PCR and immunohistochemistry were used to detect the expression of Hub gene in serous ovarian cancer tissues and cells. Downstream pathways of the candidate tumor marker genes were predicted using Gene Set Enrichment Analysis. In this study, 252 DEGs were screened for pathway enrichment. 20 Hub genes were identified. Survival analysis suggested that Aurka, Bub1b, Cenpf, Cks1b, Kif20a, Mad2l1, Racgap1, and Ube2c were associated with the survival of patients with serous ovarian cancer. MAD2L1 and BUB1B levels were significantly different in serous ovarian cancer at different stages. Finally, Mad2l1 was found to play a role in the cell cycle, oocyte meiosis, and ubiquitin-mediated proteolysis. Meanwhile, Bub1b may play a role in the cell cycle, ubiquitin-mediated proteolysis, and spliceosome processes. Mad2l1 and Bub1b could be used as markers to predict ovarian carcinogenesis and prognosis, providing candidate targets for the diagnosis and treatment of serous ovarian cancer.

13.
Breed Sci ; 74(1): 22-31, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-39246434

RESUMEN

Food shortages due to population growth and climate change are expected to occur in the near future as a problem that urgently requires solutions. Conventional breeding techniques, notably crossbreeding and mutation breeding, are known for being inefficient and time-consuming in obtaining seeds and seedlings with desired traits. Thus, there is an urgent need for novel methods for efficient plant breeding. Breeding by genome editing is receiving substantial attention because it can efficiently modify the target gene to obtain desired traits compared with conventional methods. Among the programmable sequence-specific nucleases that have been developed for genome editing, CRISPR-Cas12a and CRISPR-MAD7 nucleases are becoming more broadly adopted for the application of genome editing in grains, vegetables and fruits. Additionally, ST8, an improved variant of MAD7, has been developed to enhance genome editing efficiency and has potential for application to breeding of crops.

14.
Qual Health Res ; : 10497323241231896, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38472146

RESUMEN

Both post-qualitative inquiry and Mad methodologies sit on the fringes of qualitative health research, although their potential for creating new knowledges and practices is increasingly recognised. In this article, we explore the possibilities created by bringing these approaches together within research led by, or centring, mental health service users and survivors. We outline and reflect on a workshop undertaken with peer support workers to map affective intensities within mental health assemblages. We suggest the tensions between post-qualitative and Mad research approaches hold potential for mental health research, and qualitative health research more broadly, bringing together theory and the experiences of service users/survivors to think-feel-become otherwise in relation to health care, peer support, and activism.

15.
Int J Mol Sci ; 25(15)2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39125589

RESUMEN

Recent research into laminopathic lipodystrophies-rare genetic disorders caused by mutations in the LMNA gene-has greatly expanded our knowledge of their complex pathology and metabolic implications. These disorders, including Hutchinson-Gilford progeria syndrome (HGPS), Mandibuloacral Dysplasia (MAD), and Familial Partial Lipodystrophy (FPLD), serve as crucial models for studying accelerated aging and metabolic dysfunction, enhancing our understanding of the cellular and molecular mechanisms involved. Research on laminopathies has highlighted how LMNA mutations disrupt adipose tissue function and metabolic regulation, leading to altered fat distribution and metabolic pathway dysfunctions. Such insights improve our understanding of the pathophysiological interactions between genetic anomalies and metabolic processes. This review merges current knowledge on the phenotypic classifications of these diseases and their associated metabolic complications, such as insulin resistance, hypertriglyceridemia, hepatic steatosis, and metabolic syndrome, all of which elevate the risk of cardiovascular disease, stroke, and diabetes. Additionally, a range of published therapeutic strategies, including gene editing, antisense oligonucleotides, and novel pharmacological interventions aimed at addressing defective adipocyte differentiation and lipid metabolism, will be explored. These therapies target the core dysfunctional lamin A protein, aiming to mitigate symptoms and provide a foundation for addressing similar metabolic and genetic disorders.


Asunto(s)
Lamina Tipo A , Lipodistrofia , Humanos , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Lipodistrofia/genética , Lipodistrofia/metabolismo , Lipodistrofia/terapia , Animales , Laminopatías/genética , Laminopatías/metabolismo , Progeria/genética , Progeria/metabolismo , Progeria/patología , Mutación , Lipodistrofia Parcial Familiar/genética , Lipodistrofia Parcial Familiar/metabolismo , Lipodistrofia Parcial Familiar/terapia , Metabolismo de los Lípidos/genética , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Resistencia a la Insulina/genética , Edición Génica
16.
Nurs Inq ; 31(1): e12576, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37381596

RESUMEN

Beginning with a critical examination of the humanist assumptions of critical ethnography, this article interrogates and surfaces problems with the ontological and epistemological orientations of this research methodology. In drawing on exemplar empirical data from an arts-based project, the article demonstrates the limitations in the humanist-based qualitative research approach and advances a postdualist, postrepresentationalist direction for critical ethnography called entangled ethnography. Using data from a larger study that examined the perspectives of racialized mad artists, what is demonstrated in this inquiry is that the entanglement of bodies, objects, and meaning-making practices is central to working with the ontologically excluded, such as those who find themselves in various states of disembodiment and/or corporeal and psychic distribution. We propose the redevelopment of critical ethnography, extended by entanglement theory (a critical posthuman theory), and suggest that for it to be an inclusive methodology, critical ethnography must be conceptualized as in the process of becoming and always in regeneration, open to critique, extension, and redevelopment.


Asunto(s)
Antropología Cultural , Humanismo , Humanos , Antropología Cultural/métodos , Investigación Cualitativa , Proyectos de Investigación , Conocimiento
17.
Nurs Philos ; 25(3): e12486, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38853432

RESUMEN

Nurses working in outreach capacities frequently encounter disaffiliated or 'hard to reach' populations, such as those experiencing homelessness, those who use substances, and those with mental health concerns. Despite best efforts, nurses regularly fail to find meaningful engagement with these populations. Mobilizing the work of Deleuze and Guattari, this paper will critically examine conventional outreach nursing practices as rooted in the royal science of psychiatry, which many 'survivors' of psychiatric interventions reject. The field of Mad Studies offers an understanding of patient resistance to outreach nursing interventions. Delueze and Guattari's concepts of packs and sorcerers provide a framework to envision alternative nursing practices as a form of resistance and creativity, where new alliances may be formed outside the coercive confines of traditional practices. In response to patient resistance, outreach nurses themselves must assemble packs and engage in acts of sorcery.


Asunto(s)
Enfermeras y Enfermeros , Humanos , Enfermeras y Enfermeros/psicología
18.
EMBO J ; 38(7)2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30782962

RESUMEN

Kinetochore localized Mad1 is essential for generating a "wait anaphase" signal during mitosis, hereby ensuring accurate chromosome segregation. Inconsistent models for the function and quantitative contribution of the two mammalian Mad1 kinetochore receptors: Bub1 and the Rod-Zw10-Zwilch (RZZ) complex exist. By combining genome editing and RNAi, we achieve penetrant removal of Bub1 and Rod in human cells, which reveals that efficient checkpoint signaling depends on the integrated activities of these proteins. Rod removal reduces the proximity of Bub1 and Mad1, and we can bypass the requirement for Rod by tethering Mad1 to kinetochores or increasing the strength of the Bub1-Mad1 interaction. We find that Bub1 has checkpoint functions independent of Mad1 localization that are supported by low levels of Bub1 suggesting a catalytic function. In conclusion, our results support an integrated model for the Mad1 receptors in which the primary role of RZZ is to localize Mad1 at kinetochores to generate the Mad1-Bub1 complex.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Cinetocoros , Puntos de Control de la Fase M del Ciclo Celular , Proteínas Asociadas a Microtúbulos/metabolismo , Proteína de Unión al Tracto de Polipirimidina/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas Cromosómicas no Histona/genética , Células HeLa , Humanos , Proteínas Asociadas a Microtúbulos/genética , Mitosis , Proteína de Unión al Tracto de Polipirimidina/genética , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal , Huso Acromático
19.
J Synchrotron Radiat ; 30(Pt 5): 885-894, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37526994

RESUMEN

In X-ray macromolecular crystallography (MX), single-wavelength anomalous dispersion (SAD) and multi-wavelength anomalous dispersion (MAD) techniques are commonly used for obtaining experimental phases. For an MX synchrotron beamline to support SAD and MAD techniques it is a prerequisite to have a reliable, fast and well automated energy scan routine. This work reports on a continuous energy scan procedure newly implemented at the BioMAX MX beamline at MAX IV Laboratory. The continuous energy scan is fully automated, capable of measuring accurate fluorescence counts over the absorption edge of interest while minimizing the sample exposure to X-rays, and is about a factor of five faster compared with a conventional step scan previously operational at BioMAX. The implementation of the continuous energy scan facilitates the prompt access to the anomalous scattering data, required for the SAD and MAD experiments.

20.
J Transl Med ; 21(1): 863, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-38017538

RESUMEN

BACKGROUND: Glioblastoma, the most common primary malignant tumor of the brain, is associated with poor prognosis. Glioblastoma cells exhibit high proliferative and invasive properties, and glioblastoma stem cells (GSCs) have been shown to play a crucial role in the malignant behavior of glioblastoma cells. This study aims to investigate the molecular mechanisms involved in GSCs maintenance and malignant progression. METHODS: Bioinformatics analysis was performed based on data from public databases to explore the expression profile of Mitotic arrest deficient 2 like 2 (MAD2L2) and its potential function in glioma. The impact of MAD2L2 on glioblastoma cell behaviors was assessed through cell viability assays (CCK8), colony formation assays, 5-Ethynyl-2'-deoxyuridine (EDU) incorporation assays, scratch assays, and transwell migration/invasion assays. The findings from in vitro experiments were further validated in vivo using xenograft tumor model. GSCs were isolated from the U87 and LN229 cell lines through flow cytometry and the stemness characteristics were verified by immunofluorescence staining. The sphere-forming ability of GSCs was examined using the stem cell sphere formation assay. Bioinformatics methods were conducted to identified the potential downstream target genes of MAD2L2, followed by in vitro experimental validation. Furthermore, potential upstream transcription factors that regulate MAD2L2 expression were confirmed through chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays. RESULTS: The MAD2L2 exhibited high expression in glioblastoma samples and showed significant correlation with patient prognosis. In vitro and in vivo experiments confirmed that silencing of MAD2L2 led to decreased proliferation, invasion, and migration capabilities of glioblastoma cells, while decreasing stemness characteristics of glioblastoma stem cells. Conversely, overexpression of MAD2L2 enhanced these malignant behaviors. Further investigation revealed that MYC proto-oncogene (c-MYC) mediated the functional role of MAD2L2 in glioblastoma, which was further validated through a rescue experiment. Moreover, using dual-luciferase reporter gene assays and ChIP assays determined that the upstream transcription factor E2F-1 regulated the expression of MAD2L2. CONCLUSION: Our study elucidated the role of MAD2L2 in maintaining glioblastoma stemness and promoting malignant behaviors through the regulation of c-MYC, suggesting its potential as a therapeutic target.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Glioma , Animales , Humanos , Glioblastoma/patología , Neoplasias Encefálicas/patología , Proliferación Celular , Células Madre Neoplásicas/patología , Glioma/patología , Modelos Animales de Enfermedad , Luciferasas/metabolismo , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Proteínas Mad2/genética , Proteínas Mad2/metabolismo
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