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1.
Cell Death Discov ; 10(1): 125, 2024 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-38461295

RESUMEN

Meriolin derivatives represent a new class of kinase inhibitors with a pronounced cytotoxic potential. Here, we investigated a newly synthesized meriolin derivative (termed meriolin 16) that displayed a strong apoptotic potential in Jurkat leukemia and Ramos lymphoma cells. Meriolin 16 induced apoptosis in rapid kinetics (within 2-3 h) and more potently (IC50: 50 nM) than the previously described derivatives meriolin 31 and 36 [1]. Exposure of Ramos cells to meriolin 16, 31, or 36 for 5 min was sufficient to trigger severe and irreversible cytotoxicity. Apoptosis induction by all three meriolin derivatives was independent of death receptor signaling but required caspase-9 and Apaf-1 as central mediators of the mitochondrial death pathway. Meriolin-induced mitochondrial toxicity was demonstrated by disruption of the mitochondrial membrane potential (ΔΨm), mitochondrial release of proapoptotic Smac, processing of the dynamin-like GTPase OPA1, and subsequent fragmentation of mitochondria. Remarkably, all meriolin derivatives were able to activate the mitochondrial death pathway in Jurkat cells, even in the presence of the antiapoptotic Bcl-2 protein. In addition, meriolins were capable of inducing cell death in imatinib-resistant K562 and KCL22 chronic myeloid leukemia cells as well as in cisplatin-resistant J82 urothelial carcinoma and 2102EP germ cell tumor cells. Given the frequent inactivation of the mitochondrial apoptosis pathway by tumor cells, such as through overexpression of antiapoptotic Bcl-2, meriolin derivatives emerge as promising therapeutic agents for overcoming treatment resistance.

2.
Int J Mol Sci ; 24(21)2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37958537

RESUMEN

The survival motor neuron (SMN) complex is a multi-megadalton complex involved in post-transcriptional gene expression in eukaryotes via promotion of the biogenesis of uridine-rich small nuclear ribonucleoproteins (UsnRNPs). The functional center of the complex is formed from the SMN/Gemin2 subunit. By binding the pentameric ring made up of the Sm proteins SmD1/D2/E/F/G and allowing for their transfer to a uridine-rich short nuclear RNA (UsnRNA), the Gemin2 protein in particular is crucial for the selectivity of the Sm core assembly. It is well established that post-translational modifications control UsnRNP biogenesis. In our work presented here, we emphasize the crucial role of Gemin2, showing that the phospho-status of Gemin2 influences the capacity of the SMN complex to condense in Cajal bodies (CBs) in vivo. Additionally, we define Gemin2 as a novel and particular binding partner and phosphorylation substrate of the mTOR pathway kinase ribosomal protein S6 kinase beta-1 (p70S6K). Experiments using size exclusion chromatography further demonstrated that the Gemin2 protein functions as a connecting element between the 6S complex and the SMN complex. As a result, p70S6K knockdown lowered the number of CBs, which in turn inhibited in vivo UsnRNP synthesis. In summary, these findings reveal a unique regulatory mechanism of UsnRNP biogenesis.


Asunto(s)
Proteínas de Unión al ARN , Proteínas Quinasas S6 Ribosómicas 70-kDa , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Fosforilación , Ribonucleoproteínas Nucleares Pequeñas/genética , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas del Complejo SMN/genética , Uridina/metabolismo
3.
Front Immunol ; 14: 1257265, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37965324

RESUMEN

Background: Quantification of the SARS-CoV-2-specific immune response by serological immunoassays is critical for the management of the COVID-19 pandemic. In particular, neutralizing antibody titers to the viral spike (S) protein have been proposed as a correlate of protection (CoP). The WHO established the First International Standard (WHO IS) for anti-SARS-CoV-2 immunoglobulin (Ig) (NIBSC 20/136) to harmonize binding assays with the same antigen specificity by assigning the same unitage in binding antibody units (BAU)/ml. Method: In this study, we analyzed the S1-specific antibody response in a cohort of healthcare workers in Germany (n = 76) during a three-dose vaccination course over 8.5 months. Subjects received either heterologous or homologous prime-boost vaccination with ChAdOx1 nCoV-19 (AstraZeneca) and BNT162b2 (Pfizer-BioNTech) or three doses of BNT162b2. Antibodies were quantified using three anti-S1 binding assays (ELISA, ECLIA, and PETIA) harmonized to the WHO IS. Serum levels of neutralizing antibodies were determined using a surrogate virus neutralization test (sVNT). Binding assays were compared using Spearman's rank correlation and Passing-Bablok regression. Findings: All assays showed good correlation and similar antibody kinetics correlating with neutralizing potential. However, the assays show large proportional differences in BAU/ml. ECLIA and PETIA, which detect total antibodies against the receptor- binding domain (RBD) within the S1 subunit, interact similarly with the convalescent plasma-derived WHO IS but differently with vaccine serum, indicating a high sensitivity to the IgG/IgM/IgA ratio. Conclusion: All three binding assays allow monitoring of the antibody response in COVID-19-vaccinated individuals. However, the assay-specific differences hinder the definition of a common protective threshold in BAU/ml. Our results highlight the need for the thoughtful use of conversion factors and consideration of method-specific differences. To improve the management of future pandemics and harmonize total antibody assays, we should strive for reference material with a well-characterized Ig isotype composition.


Asunto(s)
COVID-19 , Vacunas , Humanos , Vacuna BNT162 , SARS-CoV-2 , Epítopos , ChAdOx1 nCoV-19 , Pandemias , Sueroterapia para COVID-19 , Isotipos de Inmunoglobulinas , Anticuerpos Antivirales
4.
Methods Mol Biol ; 2684: 101-109, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37410229

RESUMEN

The human COMPASS complexes regulate gene expression during development and cell differentiation. Three distinct subunits, KMT2C, KMT2D, and KDM6A (also known as UTX), are frequently mutated in urothelial carcinoma, possibly disrupting the formation of functional COMPASS complexes. Here, we describe methods to evaluate the formation of these large native protein complexes in urothelial carcinoma (UC) cell lines harboring different mutations in KMT2C/D. To this end COMPASS complexes were purified from nuclear extracts by size exclusion chromatography (SEC) using a Sepharose 6 column. SEC fractions were then separated by 3-8% Tris-acetate gradient polyacrylamide gel and the COMPASS complex subunits KMT2C, UTX, WDR5, and RBBP5 were detected by immunoblotting. In this fashion, the formation of a COMPASS complex could be observed in UC cells with wild-type but not in cells with mutant KMT2C and KMTD.


Asunto(s)
Carcinoma de Células Transicionales , Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/genética , Núcleo Celular , Diferenciación Celular , Cromatografía en Gel , Péptidos y Proteínas de Señalización Intracelular
5.
Int J Mol Sci ; 24(13)2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37446139

RESUMEN

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. The fast and accurate diagnosis of sepsis by procalcitonin (PCT) has emerged as an essential tool in clinical medicine. Although in use in the clinical laboratory for a long time, PCT quantification has not yet been standardized. The International Federation of Clinical Chemistry working group on the standardization of PCT (IFCC-WG PCT) aims to provide an LC-MS/MS-based reference method as well as the highest metrological order reference material to address this diagnostic need. Here, we present the systematic evaluation of the efficiency of an immuno-enrichment method, based on functionalized Sepharose, magnetic-core, or polystyrene (latex) nano-particles, to quantitatively precipitate PCT from different human sample materials. This method may be utilized for both mass spectrometric and proteomic purposes. In summary, only magnetic-core nano-particles functionalized by polyclonal PCT antibodies can fulfil the necessary requirements of the international standardization of PCT. An optimized method proved significant benefits in quantitative and specific precipitation as well as in the subsequent LC-MS/MS detection of PCT in human serum samples or HeLa cell extract. Based on this finding, further attempts of the PCT standardization process will utilize a magnetic core-derived immuno-enrichment step, combined with subsequent quantitative LC-MS/MS detection.


Asunto(s)
Nanopartículas , Sepsis , Humanos , Polipéptido alfa Relacionado con Calcitonina , Sefarosa , Cromatografía Liquida , Células HeLa , Poliestirenos , Proteómica , Espectrometría de Masas en Tándem , Sepsis/diagnóstico , Anticuerpos , Fenómenos Magnéticos , Biomarcadores
6.
Seizure ; 110: 21-27, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37302157

RESUMEN

PURPOSE: To analyze the safety profile of subdural and depth electrode implantation in a large monocentric cohort of patients of all ages undergoing intracranial EEG exploration because of drug resistant focal epilepsy diagnosed and implanted by a constant team of epileptologists and neurosurgeons. METHODS: We retrospectively analyzed data from 452 implantations in 420 patients undergoing invasive presurgical evaluation at the Freiburg Epilepsy Center from 1999 to 2019 (n = 160 subdural electrodes, n = 156 depth electrodes and n = 136 combination of both approaches). Complications were classified as hemorrhage with or without clinical manifestations, infection-associated and other complications. Furthermore, possible risk factors (age, duration of invasive monitoring, number of electrode contacts used) and changes in complication rates during the study period were analyzed. RESULTS: The most frequent complications in both implantation groups were hemorrhages. Subdural electrode explorations caused significantly more symptomatic hemorrhages and required more operative interventions (SDE 9.9%, DE 0.3%, p < 0.05). Hemorrhage risk was higher for grids with 64 contacts than for smaller grids (p < 0.05). The infection rate was very low (0,2%). A transient neurological deficit occurred in 8.8% of all implantations and persisted for at least 3 months in 1.3%. Transient, but not persistent neurological deficits were more common in patients with implanted subdural electrodes than in the depth electrode group. CONCLUSION: The use of subdural electrodes was associated with a higher risk of hemorrhage and transient neurological symptoms. However persistent deficits were rare with either approach, demonstrating that intracranial investigations using either subdural electrodes or depth electrodes carry acceptable risks in patients with drug-resistant focal epilepsy.


Asunto(s)
Epilepsia Refractaria , Epilepsias Parciales , Humanos , Procedimientos Neuroquirúrgicos/efectos adversos , Electroencefalografía/efectos adversos , Estudios Retrospectivos , Complicaciones Posoperatorias/etiología , Epilepsia Refractaria/diagnóstico , Electrodos Implantados/efectos adversos , Epilepsias Parciales/diagnóstico
7.
Curr Issues Mol Biol ; 45(6): 4557-4573, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37367038

RESUMEN

In recent years, various forms of caloric restriction (CR) and amino acid or protein restriction (AAR or PR) have shown not only success in preventing age-associated diseases, such as type II diabetes and cardiovascular diseases, but also potential for cancer therapy. These strategies not only reprogram metabolism to low-energy metabolism (LEM), which is disadvantageous for neoplastic cells, but also significantly inhibit proliferation. Head and neck squamous cell carcinoma (HNSCC) is one of the most common tumour types, with over 600,000 new cases diagnosed annually worldwide. With a 5-year survival rate of approximately 55%, the poor prognosis has not improved despite extensive research and new adjuvant therapies. Therefore, for the first time, we analysed the potential of methionine restriction (MetR) in selected HNSCC cell lines. We investigated the influence of MetR on cell proliferation and vitality, the compensation for MetR by homocysteine, the gene regulation of different amino acid transporters, and the influence of cisplatin on cell proliferation in different HNSCC cell lines.

8.
Neuropathol Appl Neurobiol ; 49(2): e12899, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36879456

RESUMEN

AIMS: How and why lymphoma cells home to the central nervous system and vitreoretinal compartment in primary diffuse large B-cell lymphoma of the central nervous system remain unknown. Our aim was to create an in vivo model to study lymphoma cell tropism to the central nervous system. METHODS: We established a patient-derived central nervous system lymphoma xenograft mouse model and characterised xenografts derived from four primary and four secondary central nervous system lymphoma patients using immunohistochemistry, flow cytometry and nucleic acid sequencing technology. In reimplantation experiments, we analysed dissemination patterns of orthotopic and heterotopic xenografts and performed RNA sequencing of different involved organs to detect differences at the transcriptome level. RESULTS: We found that xenografted primary central nervous system lymphoma cells home to the central nervous system and eye after intrasplenic transplantation, mimicking central nervous system and primary vitreoretinal lymphoma pathology, respectively. Transcriptomic analysis revealed distinct signatures for lymphoma cells in the brain in comparison to the spleen as well as a small overlap of commonly regulated genes in both primary and secondary central nervous system lymphoma. CONCLUSION: This in vivo tumour model preserves key features of primary and secondary central nervous system lymphoma and can be used to explore critical pathways for the central nervous system and retinal tropism with the goal to find new targets for novel therapeutic approaches.


Asunto(s)
Neoplasias del Sistema Nervioso Central , Linfoma de Células B Grandes Difuso , Neoplasias de la Retina , Humanos , Animales , Ratones , Xenoinjertos , Neoplasias de la Retina/diagnóstico , Neoplasias de la Retina/tratamiento farmacológico , Neoplasias de la Retina/patología , Cuerpo Vítreo/metabolismo , Cuerpo Vítreo/patología , Neoplasias del Sistema Nervioso Central/patología , Sistema Nervioso Central/patología , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Retina/metabolismo
9.
Comput Struct Biotechnol J ; 21: 2100-2109, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36968021

RESUMEN

The spliceosome, responsible for all mature protein-coding transcripts of eukaryotic intron-containing genes, consists of small uridine-rich nuclear ribonucleoproteins (UsnRNPs). The assembly of UsnRNPs depends, on one hand, on the arginine methylation of Sm proteins catalyzed by the PRMT5 complex. On the other hand, it depends on the phosphorylation of the PRMT5 subunit pICln by the Uncoordinated Like Kinase 1 (ULK1). In consequence, phosphorylation of pICln affects the stability of the UsnRNP assembly intermediate, the so-called 6 S complex. The detailed mechanisms of phosphorylation-dependent integrity and subsequent UsnRNP assembly of the 6 S complex in vivo have not yet been analyzed. By using a phospho-specific antibody against ULK1-dependent phosphorylation sites of pICln, we visualize the intracellular distribution of phosphorylated pICln. Furthermore, we detect the colocaliphosphor-pICln1 with phospho-pICln by size-exclusion chromatography and immunofluorescence techniques. We also show that phosphorylated pICln is predominantly present in the 6 S complex. The addition of ULK1 to in vitro produced 6 S complex, as well as the reconstitution of ULK1 in ULK1-deficient cells, increases the efficiency of snRNP biogenesis. Accordingly, inhibition of ULK1 and the associated decreased pICln phosphorylation lead to accumulation of the 6 S complex and reduction in the spliceosomal activity of the cell.

10.
Biomedicines ; 11(1)2023 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-36672668

RESUMEN

Since SARS-CoV-2 emerged in December 2019 in Wuhan, the resulting pandemic has paralyzed the economic and cultural life of the world. Variants of concern (VOC) strongly increase pressure on public health systems. Rapid, easy-to-use, and cost-effective assays are essential to manage the pandemic. Here we present a bioinformatical approach for the fast and efficient design of two innovative serological Particle Enhanced Turbidimetric Immunoassays (PETIA) to quantify the SARS-CoV-2 immunoresponse. To confirm bioinformatical assumptions, an S-RBD- and a Nucleocapsid-based PETIA were produced. Sensitivity and specificity were compared for 95 patient samples using a BioMajesty™ fully automated analyzer. The S-RBD-based PETIA showed necessary specificity (98%) over the N protein-based PETIA (21%). Further, the reactivity and cross-reactivity of the RBD-based PETIA towards variant-derived antibodies of SARS-CoV-2 were assessed by a quenching inhibition test. The inhibition kinetics of the S-RBD variants Alpha, Beta, Delta, Gamma, Kappa, and Omicron were evaluated. In summary, we showed that specific and robust PETIA immunoassays can be rapidly designed and developed. The quantification of the SARS-CoV-2-related immunoresponse of variants (Alpha to Kappa) is possible using specific RBD assays. In contrast, Omicron revealed lower cross-reactivity (approx. 50%). To ensure the quantification of the Omicron variant, modified immunoassays appear to be necessary.

11.
J Mol Cell Cardiol ; 175: 29-43, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36493853

RESUMEN

Regenerating the injured heart remains one of the most vexing challenges in cardiovascular medicine. Cell therapy has shown potential for treatment of myocardial infarction, but low cell retention so far has limited its success. Here we show that intramyocardial injection of highly apoptosis-resistant unrestricted somatic stem cells (USSC) into infarcted rat hearts resulted in an unprecedented thickening of the left ventricular wall with cTnT+/BrdU+ cardiomyocytes that was paralleled by progressively restored ejection fraction. USSC induced significant T-cell enrichment in ischemic tissue with enhanced expression of T-cell related cytokines. Inhibition of T-cell activation by anti-CD28 monoclonal antibody, fully abolished the regenerative response which was restored by adoptive T-cell transfer. Secretome analysis of USSC and lineage tracing studies suggest that USSC secrete paracrine factors over an extended period of time which boosts a T-cell driven endogenous regenerative response mainly from adult cardiomyocytes.


Asunto(s)
Células Madre Adultas , Infarto del Miocardio , Ratas , Animales , Linfocitos T , Infarto del Miocardio/terapia , Miocitos Cardíacos , Citocinas
12.
J Neurointerv Surg ; 15(7): 708-711, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35853700

RESUMEN

BACKGROUND: Minimally invasive intracranial drain placement is a common neurosurgical emergency procedure in patients with intracerebral hemorrhage (ICH). We aimed to retrospectively investigate the accuracy of conventional freehand (bedside) hemorrhage drain placement and to prospectively compare the accuracy of augmented/mixed reality-guided (AR) versus frame-based stereotaxy-guided (STX) and freehand drain placement in a phantom model. METHODS: A retrospective, single-center analysis evaluated the accuracy of drain placement in 73 consecutive ICH with a visual rating of postinterventional CT data. In a head phantom with a simulated deep ICH, five neurosurgeons performed four punctures for each technique: STX, AR, and the freehand technique. The Euclidean distance to the target point and the lateral deviation of the achieved trajectory from the planned trajectory at target point level were compared between the three methods. RESULTS: Analysis of the clinical cases revealed an optimal drainage position in only 46/73 (63%). Correction of the drain was necessary in 23/73 cases (32%). In the phantom study, accuracy of AR was significantly higher than the freehand method (P<0.001 for both Euclidean and lateral distances). The Euclidean distance using AR (median 3 mm) was close to that using STX (median 1.95 mm; P=0.023). CONCLUSIONS: We demonstrated that the accuracy of the freehand technique was low and that subsequent position correction was common. In a phantom model, AR drainage placement was significantly more precise than the freehand method. AR has great potential to increase precision of emergency intracranial punctures in a bedside setting.


Asunto(s)
Realidad Aumentada , Humanos , Estudios Retrospectivos , Punciones/métodos , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/cirugía , Drenaje/métodos
13.
Eur J Anaesthesiol ; 40(2): 121-129, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36121289

RESUMEN

BACKGROUND: Neuraxial access is necessary for an array of procedures in anaesthesia, interventional pain medicine and neurosurgery. The commonly used anatomical landmark technique is challenging and requires practical experience. OBJECTIVE: We aimed to evaluate the technical feasibility of an augmented reality-guided approach for neuraxial access and tested the hypothesis that its use would improve success as the primary outcome. As secondary outcomes, we measured accuracy and the procedural duration compared with the classical landmark approach. DESIGN: A randomised phantom-based study. SETTING: The three-dimensional image of a thoracolumbar phantom spine model with the surrounding soft tissue was created with a neurosurgical planning workstation and ideal trajectories to the epidural space on the levels T10-L1 were planned using a paramedian approach. Both the three-dimensional holographic image of the spine and the trajectories were transferred to an augmented reality-headset. Four probands (two anaesthesiologists, one neuroradiologist and one stereotactic neurosurgeon) performed 20 attempts, 10 each of either conventional landmark or augmented reality-guided epidural punctures, where anatomical level, side and sequence of modality were all randomised. OUTCOME MEASURES: Accuracy was assessed by measuring Euclidean distance and lateral deviation from the predefined target point. Success of epidural puncture on the first attempt was compared between the conventional and the augmented reality-guided approaches. RESULTS: Success was achieved in 82.5% of the attempts using augmented reality technique, compared with 40% with the conventional approach [ P  = 0.0002, odds ratio (OR) for success: 7.07]. Euclidean distance (6.1 vs. 12 mm, P  < 0.0001) and lateral deviation (3.7 vs. 9.2 mm, P  < 0.0001) were significantly smaller using augmented reality. Augmented reality-guided puncture was significantly faster than with the conventional landmark approach (52.5 vs. 67.5 s, P  = 0.0015). CONCLUSION: Augmented reality guidance significantly improved the accuracy and success in an experimental phantom model of epidural puncture. With further technical development, augmented reality guidance might prove helpful in anatomically challenging neuraxial procedures.


Asunto(s)
Realidad Aumentada , Humanos , Espacio Epidural/diagnóstico por imagen , Fantasmas de Imagen , Punciones/métodos
14.
J Med Chem ; 65(22): 15300-15311, 2022 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-36378254

RESUMEN

The PRMT5-MEP50 methyltransferase is a major target for anticancer drug discovery, and modulators of its interactions with different regulatory proteins are in high demand because they modulate PRMT5 substrate selectivity. We describe a strategy for the development of a PRMT5/adaptor protein PPI inhibitor, which includes the design and synthesis of macrocyclic peptides based on the motif for the interaction of PRMT5 with its adaptor protein RioK1. After the initial exploration of different macrocycle sizes and cyclization linkages, analysis of a peptide library identified hot spots for the variation of the amino acid structure. The incorporation of nonproteinogenic amino acids into the macrocyclic peptide led to a potent cyclic PRMT5 binding peptide (Ki = 66 nM), which selectively inhibits the interaction of PRMT5 with the adaptor proteins RioK1 and pICln (IC50 = 654 nM) but not with the alternative adaptor protein MEP50. The inhibitor is a promising tool for further biological investigation of this intriguing protein interface.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteína-Arginina N-Metiltransferasas , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Inhibidores Enzimáticos/farmacología , Descubrimiento de Drogas
15.
Cell Death Dis ; 13(11): 938, 2022 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-36347842

RESUMEN

Inhibition of the mitochondrial metabolism offers a promising therapeutic approach for the treatment of cancer. Here, we identify the mycotoxin viriditoxin (VDT), derived from the endophytic fungus Cladosporium cladosporioides, as an interesting candidate for leukemia and lymphoma treatment. VDT displayed a high cytotoxic potential and rapid kinetics of caspase activation in Jurkat leukemia and Ramos lymphoma cells in contrast to solid tumor cells that were affected to a much lesser extent. Most remarkably, human hematopoietic stem and progenitor cells and peripheral blood mononuclear cells derived from healthy donors were profoundly resilient to VDT-induced cytotoxicity. Likewise, the colony-forming capacity was affected only at very high concentrations, which provides a therapeutic window for cancer treatment. Intriguingly, VDT could directly activate the mitochondrial apoptosis pathway in leukemia cells in the presence of antiapoptotic Bcl-2 proteins. The mitochondrial toxicity of VDT was further confirmed by inhibition of mitochondrial respiration, breakdown of the mitochondrial membrane potential (ΔΨm), the release of mitochondrial cytochrome c, generation of reactive oxygen species (ROS), processing of the dynamin-like GTPase OPA1 and subsequent fission of mitochondria. Thus, VDT-mediated targeting of mitochondrial oxidative phosphorylation (OXPHOS) might represent a promising therapeutic approach for the treatment of leukemia and lymphoma without affecting hematopoietic stem and progenitor cells.


Asunto(s)
Leucemia , Linfoma , Micotoxinas , Humanos , Micotoxinas/metabolismo , Leucocitos Mononucleares/metabolismo , Apoptosis , Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Leucemia/tratamiento farmacológico , Leucemia/metabolismo , Linfoma/tratamiento farmacológico , Linfoma/metabolismo , Potencial de la Membrana Mitocondrial
16.
Front Immunol ; 13: 915338, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36059441

RESUMEN

Background: Since December 2019, SARS-CoV-2 has been keeping the world in suspense. Rapid tests, molecular diagnosis of acute infections, and vaccination campaigns with vaccines are building blocks of strategic pandemic control worldwide. For laboratory diagnostics, the quantification of the antibody titer of convalescents and vaccinated patients is thus increasingly coming to the fore. Methods: Here we present an evaluation on the comparability of five serological tests on a cohort of 13 patients with mild COVID-19 disease. Also participants who were vaccinated after recovery were included in this study. All common immune methods (ELISA, CLIA, PETIA) and SARS-CoV-2 specific antigens (N-, S1- and RBD-) were specifically tracked and directly compared for up to 455 days. The titer of recovered participants was also set to the degree of symptoms during infection and the occurrence of Long-COVID. In addition, relative comparability of different serological tests, all standardized to WHO, was set in reference to the neutralizing potential of the corresponding participants. Findings: The individual immune responses over 455 days after a mild SARS-CoV-2 infection remain stable, in contrast to vaccinated participants. All sero-tests reveal comparable performance and dynamics during the study and compared well to a surrogate neutralization test. Conclusion: The information presented here will help clinicians in the daily laboratory work in the selection and evaluation of different serological tests offered. The data also will support in respect of a sero-test-based neutralization cutoff.


Asunto(s)
COVID-19 , Anticuerpos Antivirales , COVID-19/complicaciones , Humanos , Pandemias , SARS-CoV-2 , Síndrome Post Agudo de COVID-19
17.
Biol Chem ; 403(10): 907-915, 2022 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-36040368

RESUMEN

Protein-arginine methylation is a common posttranslational modification, crucial to various cellular processes, such as protein-protein interactions or binding to nucleic acids. The central enzyme of symmetric protein arginine methylation in mammals is the protein arginine methyltransferase 5 (PRMT5). While the methylation reaction itself is well understood, recruitment and differentiation among substrates remain less clear. One mechanism to regulate the diversity of PRMT5 substrate recognition is the mutual binding to the adaptor proteins pICln or RioK1. Here, we describe the specific interaction of Nuclear Factor 90 (NF90) with the PRMT5-WD45-RioK1 complex. We show for the first time that NF90 is symmetrically dimethylated by PRMT5 within the RG-rich region in its C-terminus. Since upregulation of PRMT5 is a hallmark of many cancer cells, the characterization of its dimethylation and modulation by specific commercial inhibitors in vivo presented here may contribute to a better understanding of PRMT5 function and its role in cancer.


Asunto(s)
Proteínas del Factor Nuclear 90 , Proteína-Arginina N-Metiltransferasas , Animales , Arginina/metabolismo , Mamíferos/metabolismo , Metilación , Proteínas del Factor Nuclear 90/genética , Proteínas del Factor Nuclear 90/metabolismo , Procesamiento Proteico-Postraduccional , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo
18.
Neurosurg Rev ; 45(4): 2745-2755, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35441994

RESUMEN

Defects of the cranial vault often require cosmetic reconstruction with patient-specific implants, particularly in cases of craniofacial involvement. However, fabrication takes time and is expensive; therefore, efforts must be made to develop more rapidly available and more cost-effective alternatives. The current study investigated the feasibility of an augmented reality (AR)-assisted single-step procedure for repairing bony defects involving the facial skeleton and the skull base. In an experimental setting, nine neurosurgeons fabricated AR-assisted and conventionally shaped ("freehand") implants from polymethylmethacrylate (PMMA) on a skull model with a craniofacial bony defect. Deviations of the surface profile in comparison with the original model were quantified by means of volumetry, and the cosmetic results were evaluated using a multicomponent scoring system, each by two blinded neurosurgeons. Handling the AR equipment proved to be quite comfortable. The median volume deviating from the surface profile of the original model was low in the AR-assisted implants (6.40 cm3) and significantly reduced in comparison with the conventionally shaped implants (13.48 cm3). The cosmetic appearance of the AR-assisted implants was rated as very good (median 25.00 out of 30 points) and significantly improved in comparison with the conventionally shaped implants (median 14.75 out of 30 points). Our experiments showed outstanding results regarding the possibilities of AR-assisted procedures for single-step reconstruction of craniofacial defects. Although patient-specific implants still represent the gold standard in esthetic aspects, AR-assisted procedures hold high potential for an immediately and widely available, cost-effective alternative providing excellent cosmetic outcomes.


Asunto(s)
Realidad Aumentada , Neurocirugia , Procedimientos de Cirugía Plástica , Craneotomía/métodos , Humanos , Prótesis e Implantes , Procedimientos de Cirugía Plástica/métodos , Cráneo/cirugía , Base del Cráneo/cirugía
19.
Artículo en Alemán | MEDLINE | ID: mdl-35419640

RESUMEN

In addition to the national pandemic plan to cope with the COVID-19 pandemic, it is stipulated that the Federal Centre for Health Education (BZgA) provides information on coronavirus SARS-CoV­2 for the general population via a subpage of www.infektionsschutz.de . In particular, the informational material should contain answers to frequently asked questions (FAQ) as well as behavioural recommendations for prevention.This article describes how information content is created ad hoc in the form of FAQ and why these FAQ are significant for crisis communication. The evolution of the FAQ from a simple information instrument to an inter-institutional rapid reaction tool in the context of risk communication on COVID-19 becomes clear. Close cooperation between the authorities is required to ensure that information is provided in a congruent and up-to-date manner. The work and coordination processes as well as various update procedures are presented. Theoretical implications for crisis communication and crisis management can be derived from the work processes described and assessed.These processes can be taken up by other institutions as examples of good practice and, if necessary, further developed and/or transferred to other contexts.


Asunto(s)
COVID-19 , COVID-19/prevención & control , Comunicación , Alemania/epidemiología , Humanos , Pandemias/prevención & control , SARS-CoV-2
20.
Clin Chim Acta ; 529: 67-75, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35167843

RESUMEN

BACKGROUND AND AIMS: Sepsis is a major concern worldwide, affecting 49 million individuals and being related to 11 million deaths. Its fast diagnosis is the key factor to guarantee a positive prognosis. Procalcitonin (PCT) has emerged as one powerful biomarker to early diagnose sepsis and for monitoring of antibiotic treatment. However, its clinical utility is jeopardized by missing standardisation. MATERIALS AND METHODS: Here we present a 1-year follow-up of the External Quality Assessment (EQA) in Germany, depicting substantial discrepancies among manufacturers and the used assay technology of current PCT measurements. A direct method comparison on two immunoassays (Abbott vs. DiaSys) on a set of 135 routine samples was used to analyse the causes of observed deviations. RESULTS: All BRAHMS-licensed manufacturers (Thermo, Roche, Abbott, Siemens, Biomérieux), the Beckman and DiaSys immunoassays as well as all assay types (fluorescence, luminescence, PETIA) reveal substantial recovery differences between each other. However, upon a non-linear re-standardization of calibrators, the two directly compared methods (Abbott, DiaSys) are well interchangeable. CONCLUSION: This work demonstrates the heterogenic situation of PCT measurements in Germany among manufacturers and all methods. By introducing dedicated correction factors, comparable results of PCT can be achieved. This work also strengthens the inevitability of calibrator traceability and higher metrological reference materials on PCT.


Asunto(s)
Polipéptido alfa Relacionado con Calcitonina , Sepsis , Biomarcadores , Humanos , Inmunoensayo/métodos , Estándares de Referencia , Sepsis/diagnóstico
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