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The EMBO Journal discusses the current state of RNA research and presents a series of review articles throughout 2023 that will cover various aspects of RNA biology.
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Looking back at the journal's first issue in January 1982 provides an opportunity to reflect on its historical development and to introduce upcoming initiatives.
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Stress granules (SGs) are cytoplasmic assemblies of mRNPs stalled in translation initiation. They are induced by various stress conditions, including exposure to the environmental toxin and carcinogen arsenic. While perturbed SG turnover is linked to the pathogenesis of neurodegenerative diseases, the molecular mechanisms underlying SG formation and turnover are still poorly understood. Here, we show that ZFAND1 is an evolutionarily conserved regulator of SG clearance. ZFAND1 interacts with two key factors of protein degradation, the 26S proteasome and the ubiquitin-selective segregase p97, and recruits them to arsenite-induced SGs. In the absence of ZFAND1, SGs lack the 26S proteasome and p97, accumulate defective ribosomal products, and persist after arsenite removal, indicating their transformation into aberrant, disease-linked SGs. Accordingly, ZFAND1 depletion is epistatic to the expression of pathogenic mutant p97 with respect to SG clearance, suggesting that ZFAND1 function is relevant to the multisystem degenerative disorder IBMPFD/ALS.
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Arsenitos/toxicidad , Gránulos Citoplasmáticos/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Compuestos de Sodio/toxicidad , Estrés Fisiológico , Factor 2 Asociado a Receptor de TNF/metabolismo , Autofagia/efectos de los fármacos , Gránulos Citoplasmáticos/enzimología , Gránulos Citoplasmáticos/patología , Células HEK293 , Células HeLa , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Complejo de la Endopetidasa Proteasomal/genética , Transporte de Proteínas , Proteolisis , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Transducción de Señal/efectos de los fármacos , Factor 2 Asociado a Receptor de TNF/genéticaRESUMEN
Human RECQL4 is a member of the RecQ family of DNA helicases and functions during DNA replication and repair. RECQL4 mutations are associated with developmental defects and cancer. Although RECQL4 mutations lead to disease, RECQL4 overexpression is also observed in cancer, including breast and prostate. Thus, tight regulation of RECQL4 protein levels is crucial for genome stability. Because mammalian RECQL4 is essential, how cells regulate RECQL4 protein levels is largely unknown. Utilizing budding yeast, we investigated the RECQL4 homolog, HRQ1, during DNA crosslink repair. We find that Hrq1 functions in the error-free template switching pathway to mediate DNA intrastrand crosslink repair. Although Hrq1 mediates repair of cisplatin-induced lesions, it is paradoxically degraded by the proteasome following cisplatin treatment. By identifying the targeted lysine residues, we show that preventing Hrq1 degradation results in increased recombination and mutagenesis. Like yeast, human RECQL4 is similarly degraded upon exposure to crosslinking agents. Furthermore, over-expression of RECQL4 results in increased RAD51 foci, which is dependent on its helicase activity. Using bioinformatic analysis, we observe that RECQL4 overexpression correlates with increased recombination and mutations. Overall, our study uncovers a role for Hrq1/RECQL4 in DNA intrastrand crosslink repair and provides further insight how misregulation of RECQL4 can promote genomic instability, a cancer hallmark.
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Neoplasias de la Mama , Proteínas de Saccharomyces cerevisiae , Neoplasias de la Mama/genética , Cisplatino/farmacología , ADN , Femenino , Inestabilidad Genómica/genética , Humanos , Lisina/genética , Complejo de la Endopetidasa Proteasomal/genética , RecQ Helicasas/metabolismo , Recombinación Genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMEN
Nucleotide excision repair (NER) is an evolutionarily conserved mechanism that processes helix-destabilizing and/or -distorting DNA lesions, such as UV-induced photoproducts. Here, we investigate the dynamic protein-DNA interactions during the damage recognition step using single-molecule fluorescence microscopy. Quantum dot-labeled Rad4-Rad23 (yeast XPC-RAD23B ortholog) forms non-motile complexes or conducts a one-dimensional search via either random diffusion or constrained motion. Atomic force microcopy analysis of Rad4 with the ß-hairpin domain 3 (BHD3) deleted reveals that this motif is non-essential for damage-specific binding and DNA bending. Furthermore, we find that deletion of seven residues in the tip of ß-hairpin in BHD3 increases Rad4-Rad23 constrained motion at the expense of stable binding at sites of DNA lesions, without diminishing cellular UV resistance or photoproduct repair in vivo. These results suggest a distinct intermediate in the damage recognition process during NER, allowing dynamic DNA damage detection at a distance.
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Reparación del ADN , ADN de Hongos/genética , Proteínas de Unión al ADN/genética , Regulación Fúngica de la Expresión Génica , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/efectos de la radiación , Secuencia de Aminoácidos , Secuencia de Bases , Sitios de Unión , Daño del ADN , ADN de Hongos/química , ADN de Hongos/metabolismo , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Microscopía de Fuerza Atómica , Microscopía Fluorescente , Conformación de Ácido Nucleico , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Puntos Cuánticos/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Eliminación de Secuencia , Imagen Individual de Molécula , Rayos UltravioletaRESUMEN
BackgroundUnprecedented non-pharmaceutical interventions to control the COVID-19 pandemic also had an effect on other infectious diseases.AimWe aimed to determine their impact on transmission and diagnosis of notifiable diseases other than COVID-19 in Bavaria, Germany, in 2020 and 2021.MethodsWe compared weekly cases of 15 notifiable infectious diseases recorded in Bavaria between 1 January 2016 and 31 December 2021 in time series analyses, median age and time-to-diagnosis using Wilcoxon rank sum test and hospitalisation rates using univariable logistic regression during three time periods: pre-pandemic (weeks 1 2016-9 2020), pandemic years 1 (weeks 10-52 2020) and 2 (2021).ResultsWeekly case numbers decreased in pandemic year 1 for all diseases assessed except influenza, Lyme disease and tick-borne encephalitis; markedly for norovirus gastroenteritis (IRR = 0.15; 95% CI: 0.12-0.20) and pertussis (IRR = 0.22; 95% CI: 0.18-0.26). In pandemic year 2, influenza (IRR = 0.04; 95% CI: 0.02-0.09) and pertussis (IRR = 0.11; 95% CI: 0.09-0.14) decreased markedly, but also chickenpox, dengue fever, Haemophilus influenzae invasive infection, hepatitis C, legionellosis, noro- and rotavirus gastroenteritis and salmonellosis. For enterohaemorrhagic Escherichia coli infections, median age decreased in pandemic years 1 and 2 (4 years, interquartile range (IQR): 1-32 and 3 years, IQR: 1-18 vs 11 years, IQR: 2-42); hospitalisation proportions increased in pandemic year 1 (OR = 1.60; 95% CI: 1.08-2.34).ConclusionReductions for various infectious diseases and changes in case characteristics in 2020 and 2021 indicate reduced transmission of notifiable diseases other than COVID-19 due to interventions and under-detection.
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COVID-19 , Enfermedades Transmisibles , Gastroenteritis , Gripe Humana , Tos Ferina , Humanos , Pandemias , Tos Ferina/epidemiología , Gripe Humana/epidemiología , COVID-19/epidemiología , Enfermedades Transmisibles/epidemiología , Gastroenteritis/epidemiologíaRESUMEN
BackgroundLyme borreliosis (LB), caused by Borrelia burgdorferi (Bb), is the most common tick-borne infection in Germany. Antibodies against Bb are prevalent in the general population but information on temporal changes of prevalence and estimates of seroconversion (seroincidence) and seroreversion are lacking, especially for children and adolescents.AimWe aimed at assessing antibodies against Bb and factors associated with seropositivity in children and adolescents in Germany.MethodsWe estimated seroprevalence via two consecutive cross-sectional surveys (2003-2006 and 2014-2017). Based on a longitudinal survey component, we estimated annual seroconversion/seroreversion rates.ResultsSeroprevalence was 4.4% (95% confidence interval (CI): 3.9-4.9%) from 2003 to 2006 and 4.1% (95% CI: 3.2-5.1%) from 2014 to 2017. Seroprevalence increased with age, was higher in male children, the south-eastern regions of Germany and among those with a high socioeconomic status. The annual seroconversion rate was 0.3% and the annual seroreversion rate 3.9%. Males were more likely to seroconvert compared with females. Low antibody levels were the main predictor of seroreversion.ConclusionWe did not detect a change in seroprevalence in children and adolescents in Germany over a period of 11â¯years. Potential long-term changes, for example due to climatic changes, need to be assessed in consecutive serosurveys. Seroconversion was more likely among children and adolescents than among adults, representing a target group for preventive measures. Seroreversion rates are over twice as high in children and adolescents compared with previous studies among adults. Thus, seroprevalence estimates and seroconversion rates in children are likely underestimated.
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Borrelia burgdorferi , Enfermedad de Lyme , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Anticuerpos Antibacterianos , Estudios Transversales , Alemania/epidemiología , Inmunoglobulina G , Seroconversión , Estudios Seroepidemiológicos , Enfermedad de Lyme/epidemiologíaRESUMEN
Pathogenic germline TP53 variants predispose to a wide range of early onset cancers, often recognized as the Li-Fraumeni syndrome (LFS). They are also identified in 1% of families with hereditary breast cancer (HrBC) that do not fulfill the criteria for LFS. In this study, we present a total of 24 different TP53 variants identified in 31 Swedish families with LFS or HrBC. Ten of these variants, nine exonic and one splice, have previously not been described as germline pathogenic variants. The nine exonic variants were functionally characterized and demonstrated partial transactivation activity compared to wild-type p53. Some show nuclear localization similar to wild-type p53 while others possess cytoplasmic or perinuclear localization. The four frameshift variants (W91Gfs*32, L111 Wfs*12, S227 Lfs*20 and S240Kfs*25) had negligible, while F134 L and T231del had low level of p53 activity. The L111 Wfs*12 and T231del variants are also deficient for induction of apoptosis. The missense variant R110C retain p53 effects and the nonsense E349* shows at least partial transcription factor activity but has reduced ability to trigger apoptosis. This is the first functional characterization of novel germline TP53 pathogenic or likely pathogenic variants in the Swedish cohort as an attempt to understand its association with LFS and HrBC, respectively.
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Variación Genética , Mutación de Línea Germinal , Proteína p53 Supresora de Tumor/genética , Alelos , Sustitución de Aminoácidos , Apoptosis , Línea Celular Tumoral , Regulación de la Expresión Génica , Estudios de Asociación Genética , Sitios Genéticos , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Síndrome de Li-Fraumeni/genética , Transporte de Proteínas , Análisis de Secuencia de ADN , SueciaRESUMEN
BACKGROUND: In Germany, antenatal influenza vaccination is recommended since 2010, but uptake remains low. Several countries recently introduced antenatal pertussis vaccination, which is currently under consideration in Germany. We conducted a survey among gynaecologists on attitudes, practices and barriers regarding influenza and pertussis vaccination during pregnancy. METHODS: Gynaecologists were invited to complete a pre-tested, 24-item questionnaire published in the German Professional Association of Gynaecologists' journal in September 2017 within 2 months. Associations between variables were examined using Chi-Squared, Fischer's Exact or t-tests. Variables associated with gynaecologists' self-reported implementation of vaccination in pregnant women were identified using univariate and multivariate logistic regression analyses. RESULTS: Of 867 participants (response 11%), 91.4 and 59.4% reported currently vaccinating pregnant women against influenza and pertussis, respectively. Gynaecologists who reported obtaining annual influenza vaccination and actively informing their patients about these vaccinations were significantly more likely to vaccinate pregnant women against influenza (96.5% vs. 65.7 and 95.1% vs. 62.2%) and pertussis (63.1% vs. 44.3 and 82.4% vs. 12.9%). Performing influenza vaccination was least likely among gynaecologists who perceived logistical difficulties as a vaccination barrier (35.9%), while pertussis vaccination was least likely if the lacking official recommendation (32.0%), logistical difficulties (27.1%), safety concerns (17.5%) and limited vaccine effectiveness (11.1%) were perceived as barriers. Of participants not yet vaccinating pregnant women against pertussis, 86.5% reported they would follow an official recommendation. Including vaccination recommendations in the maternity record (95.2%) and informing the public (88.7%) and health care professionals (86.6%) were considered the most suitable measures to achieve high pertussis vaccination coverage. CONCLUSIONS: The large proportion reporting performance of influenza vaccination during pregnancy and high acceptance of a potential recommendation for pertussis vaccination reflected positive attitudes towards vaccination among participants. However, factors associated with failure to vaccinate may be more prevalent among non-participants. Results suggest that gynaecologists' confidence in vaccination is crucial for implementing vaccination in pregnancy. Thus, doubts on vaccine effectiveness and safety should be allayed among gynaecologists and pregnant women via various communication channels, and solutions for logistical barriers sought. Including antenatal vaccination recommendations in the maternity record would serve as an important reminder for both groups.
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Actitud del Personal de Salud , Conocimientos, Actitudes y Práctica en Salud , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Aceptación de la Atención de Salud , Tos Ferina/prevención & control , Femenino , Alemania , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud/estadística & datos numéricos , Embarazo , Encuestas y CuestionariosRESUMEN
Damage repair mechanisms at transcriptionally active sites during the G0/G1 phase are largely unknown. To elucidate these mechanisms, we introduced genome site-specific oxidative DNA damage and determined the role of transcription in repair factor assembly. We find that KU and NBS1 are recruited to damage sites independent of transcription. However, assembly of RPA1, RAD51C, RAD51, and RAD52 at such sites is strictly governed by active transcription and requires both wild-type Cockayne syndrome protein B (CSB) function and the presence of RNA in the G0/G1 phase. We show that the ATPase activity of CSB is indispensable for loading and binding of the recombination factors. CSB counters radiation-induced DNA damage in both cells and zebrafish models. Taken together, our results have uncovered a novel, RNA-based recombination mechanism by which CSB protects genome stability from strand breaks at transcriptionally active sites and may provide insight into the clinical manifestations of Cockayne syndrome.
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Ciclo Celular/genética , Daño del ADN , ADN Helicasas/genética , Enzimas Reparadoras del ADN/genética , Recombinación Homóloga , ARN/genética , Antígenos Nucleares/genética , Antígenos Nucleares/metabolismo , Western Blotting , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Células Cultivadas , Síndrome de Cockayne/genética , Síndrome de Cockayne/metabolismo , Síndrome de Cockayne/patología , ADN Helicasas/metabolismo , Reparación del ADN , Enzimas Reparadoras del ADN/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Fase G1/genética , Células HEK293 , Células HeLa , Humanos , Autoantígeno Ku , Microscopía Confocal , Modelos Genéticos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Unión a Poli-ADP-Ribosa , ARN/metabolismo , Interferencia de ARN , Recombinasa Rad51/genética , Recombinasa Rad51/metabolismo , Proteína Recombinante y Reparadora de ADN Rad52/genética , Proteína Recombinante y Reparadora de ADN Rad52/metabolismo , Proteína de Replicación A/genética , Proteína de Replicación A/metabolismo , Fase de Descanso del Ciclo Celular/genética , Transcripción GenéticaRESUMEN
DNA damage must be repaired in an accurate and timely fashion to preserve genome stability. Cellular mechanisms preventing genome instability are crucial to human health because genome instability is considered a hallmark of cancer. Collectively referred to as the DNA damage response, conserved pathways ensure proper DNA damage recognition and repair. The function of numerous DNA damage response components is fine-tuned by posttranslational modifications, including ubiquitination. This not only involves the enzyme cascade responsible for conjugating ubiquitin to substrates but also requires enzymes that mediate directed removal of ubiquitin. Deubiquitinases remove ubiquitin from substrates to prevent degradation or to mediate signaling functions. The Saccharomyces cerevisiae deubiquitinase Ubp7 has been characterized previously as an endocytic factor. However, here we identify Ubp7 as a novel factor affecting S phase progression after hydroxyurea treatment and demonstrate an evolutionary and genetic interaction of Ubp7 with DNA damage repair pathways of homologous recombination and nucleotide excision repair. We find that deletion of UBP7 sensitizes cells to hydroxyurea and cisplatin and demonstrate that factors that stabilize replication forks are critical under these conditions. Furthermore, ubp7Δ cells exhibit an S phase progression defect upon checkpoint activation by hydroxyurea treatment. ubp7Δ mutants are epistatic to factors involved in histone maintenance and modification, and we find that a subset of Ubp7 is chromatin-associated. In summary, our results suggest that Ubp7 contributes to S phase progression by affecting the chromatin state at replication forks, and we propose histone H2B ubiquitination as a potential substrate of Ubp7.
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Cromatina/enzimología , Proteínas Fúngicas/metabolismo , Fase S , Saccharomycetales/enzimología , Proteasas Ubiquitina-Específicas/metabolismo , Cromatina/efectos de los fármacos , Cromatina/metabolismo , Cisplatino/farmacología , Reactivos de Enlaces Cruzados/farmacología , Reparación del ADN , Replicación del ADN/efectos de los fármacos , Proteínas Fúngicas/genética , Eliminación de Gen , Inestabilidad Genómica/efectos de los fármacos , Histonas/metabolismo , Hidroxiurea/farmacología , Viabilidad Microbiana/efectos de los fármacos , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Fase S/efectos de los fármacos , Saccharomycetales/citología , Saccharomycetales/efectos de los fármacos , Saccharomycetales/crecimiento & desarrollo , Proteasas Ubiquitina-Específicas/genéticaRESUMEN
The cellular response to DNA double-strand breaks is orchestrated by the protein kinase ATM, which phosphorylates key actors in the DNA repair network. WRAP53ß is a multifunctional protein that controls trafficking of factors to Cajal bodies, telomeres and DNA double-strand breaks but what regulates the involvement of WRAP53ß in these separate processes remains unclear. Here, we show that in response to various types of DNA damage, including IR and UV, WRAP53ß is phosphorylated on serine residue 64 by ATM with a time-course that parallels its accumulation at DNA lesions. Interestingly, recruitment of phosphorylated WRAP53ß (pWRAP53ßS64) to sites of such DNA damage promotes its interaction with γH2AX at these locations. Moreover, pWRAP53ßS64 stimulates the accumulation of the repair factor 53BP1 at DNA double-strand breaks and enhances repair of this type of damage via homologous recombination and non-homologous end joining. At the same time, phosphorylation of WRAP53ß is dispensable for its localization to Cajal bodies, where it accumulates even in unstressed cells. These findings not only reveal ATM to be an upstream regulator of WRAP53ß, but also indicates that phosphorylation of WRAP53ß at serine 64 controls its involvement in the DNA damage response and may also restrict its other functions.
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Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Cuerpos Enrollados/metabolismo , Daño del ADN , Telomerasa/metabolismo , Línea Celular Tumoral , Roturas del ADN de Doble Cadena/efectos de la radiación , Daño del ADN/efectos de los fármacos , Daño del ADN/efectos de la radiación , Reparación del ADN , Proteínas de Unión al ADN/metabolismo , Histonas/metabolismo , Humanos , Modelos Biológicos , Chaperonas Moleculares , Fosforilación , Unión Proteica , Radiación Ionizante , Rayos UltravioletaRESUMEN
The chromatin-remodelling complex B-WICH, comprised of William syndrome transcription factor, the ATPase SNF2h and nuclear myosin, specifically activates RNA polymerase III transcription of the 5S rRNA and 7SL genes. However, the underlying mechanism is unknown. Using high-resolution MN walking we demonstrate here that B-WICH changes the chromatin structure in the vicinity of the 5S rRNA and 7SL RNA genes during RNA polymerase III transcription. The action of B-WICH is required for the binding of the RNA polymerase machinery and the regulatory factors c-Myc at the 5S rRNA and 7SL RNA genes. In addition to the c-Myc binding site at the 5S genes, we have revealed a novel c-Myc and Max binding site in the intergenic spacer of the 5S rDNA. This region also contains a region remodelled by B-WICH. We demonstrate that c-Myc binds to both sites in a Max-dependent way, and thereby activate transcription by acetylating histone H3. The novel binding patterns of c-Myc and Max link transcription of 5S rRNA to the Myc/Max/Mxd network. Since B-WICH acts prior to c-Myc and other factors, we propose a model in which the B-WICH complex is required to maintain an open chromatin structure at these RNA polymerase III genes. This is a prerequisite for the binding of additional regulatory factors.
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Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Ensamble y Desensamble de Cromatina , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Polimerasa III/metabolismo , Factores de Transcripción/metabolismo , Activación Transcripcional , Sitios de Unión , Cromatina/química , Células HeLa , Histona Acetiltransferasas/metabolismo , Histonas/metabolismo , Humanos , Unión Proteica , ARN Ribosómico 5S/genética , ARN Citoplasmático Pequeño/genética , Partícula de Reconocimiento de Señal/genéticaRESUMEN
BACKGROUND: Lymphatic fistulas are common complications after lymph node dissections in melanoma patients. We investigated whether drain management could improve the patient's outcome. METHODS: Patients who underwent axillary or inguinal lymph node dissection (RALND or RILND) for malignant melanoma were recorded in a prospective database. Two different methods of drain management were compared. Either the drain was removed no later than the eighth postoperative day (period I, 2003-2007) or it was left in place until fluid flow was below 50 ml in 24 h for two consecutive days (period II, 2008-2011). The main outcome criterion was the incidence of seroma punctures after drain removal. RESULTS: 374 patients were analysed. The incidence of seroma punctures significantly decreased in period II. The number of patients with elevated lymphatic secretions rose by 41.3% (RALND) and 38.1% (RILND). With the exception of lymphatic fistulas, we observed significantly more local complications with need for treatment in period I (n = 104, 52%) than in period II (n = 31, 18%). In period II, the hospital stays after both procedures were significantly reduced. CONCLUSIONS: We conclude that quantity-guided drain management leads to a prolonged interval of drainage but is associated with a lower incidence of seroma formation and shorter hospital stay.
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Drenaje/métodos , Escisión del Ganglio Linfático/efectos adversos , Melanoma/cirugía , Seroma/prevención & control , Neoplasias Cutáneas/cirugía , Infección de la Herida Quirúrgica/prevención & control , Adulto , Anciano , Estudios de Cohortes , Femenino , Humanos , Incidencia , Tiempo de Internación , Masculino , Melanoma/secundario , Persona de Mediana Edad , Cuidados Posoperatorios , Seroma/epidemiología , Neoplasias Cutáneas/patología , Infección de la Herida Quirúrgica/epidemiologíaRESUMEN
Actin and nuclear myosin 1c (NM1) cooperate in RNA polymerase I (pol I) transcription. NM1 is also part of a multiprotein assembly, B-WICH, which is involved in transcription. This assembly contains the chromatin remodeling complex WICH with its subunits WSTF and SNF2h. We report here that NM1 binds SNF2h with enhanced affinity upon impairment of the actin-binding function. ChIP analysis revealed that NM1, SNF2h, and actin gene occupancies are cell cycle-dependent and require intact motor function. At the onset of cell division, when transcription is temporarily blocked, B-WICH is disassembled due to WSTF phosphorylation, to be reassembled on the active gene at exit from mitosis. NM1 gene knockdown and motor function inhibition, or stable expression of NM1 mutants that do not interact with actin or chromatin, overall repressed rRNA synthesis by stalling pol I at the gene promoter, led to chromatin alterations by changing the state of H3K9 acetylation at gene promoter, and delayed cell cycle progression. These results suggest a unique structural role for NM1 in which the interaction with SNF2h stabilizes B-WICH at the gene promoter and facilitates recruitment of the HAT PCAF. This leads to a permissive chromatin structure required for transcription activation.
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Actinas , Puntos de Control del Ciclo Celular , Ensamble y Desensamble de Cromatina/genética , Miosina Tipo I , ARN Ribosómico , Acetilación , Actinas/genética , Actinas/metabolismo , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Núcleo Celular/metabolismo , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Células HEK293 , Células HeLa , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Miosina Tipo I/genética , Miosina Tipo I/metabolismo , Regiones Promotoras Genéticas , Unión Proteica , ARN Polimerasa I/metabolismo , ARN Ribosómico/genética , ARN Ribosómico/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcripción GenéticaRESUMEN
The mod(mdg4) locus of Drosophila melanogaster contains several transcription units encoded on both DNA strands. The mod(mdg4) pre-mRNAs are alternatively spliced, and a very significant fraction of the mature mod(mdg4) mRNAs are formed by trans-splicing. We have studied the transcripts derived from one of the anti-sense regions within the mod(mdg4) locus in order to shed light on the expression of this complex locus. We have characterized the expression of anti-sense mod(mdg4) transcripts in S2 cells, mapped their transcription start sites and cleavage sites, identified and quantified alternatively spliced transcripts, and obtained insight into the regulation of the mod(mdg4) trans-splicing. In a previous study, we had shown that the alternative splicing of some mod(mdg4) transcripts was regulated by Brahma (BRM), the ATPase subunit of the SWI/SNF chromatin-remodeling complex. Here we show, using RNA interference and overexpression of recombinant BRM proteins, that the levels of BRM affect specifically the abundance of a trans-spliced mod(mdg4) mRNA isoform in both S2 cells and larvae. This specific effect on trans-splicing is accompanied by a local increase in the density of RNA polymerase II and by a change in the phosphorylation state of the C-terminal domain of the large subunit of RNA polymerase II. Interestingly, the regulation of the mod(mdg4) splicing by BRM is independent of the ATPase activity of BRM, which suggests that the mechanism by which BRM modulates trans-splicing is independent of its chromatin-remodeling activity.
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Proteínas de Ciclo Celular/metabolismo , Ensamble y Desensamble de Cromatina , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Interferencia de ARN , ARN/metabolismo , Transactivadores/metabolismo , Trans-Empalme , Factores de Transcripción/genética , Empalme Alternativo , Animales , Línea Celular , Drosophila melanogaster/embriología , Drosophila melanogaster/genética , Regulación de la Expresión Génica , División del ARN , Isoformas de ARN/metabolismo , ARN Polimerasa II/metabolismo , Sitio de Iniciación de la TranscripciónRESUMEN
In 2020, a record number of tick-borne encephalitis (TBE) cases was reported in major endemic areas in Germany, i.e., the southern federal states of Baden-Wuerttemberg and Bavaria. Most cases were unvaccinated. Other tick-borne diseases (TBDs), including Lyme borreliosis and tularemia, are rising, too. Thus, strategies are needed to increase TBE vaccination uptake in risk areas and promote education on TBD prevention. Primary care physicians are key providers of both vaccinations and TBD education. The TBD-Prevention (TBD-Prev) study aimed to investigate the knowledge, attitudes and behaviors of primary care physicians in Baden-Wuerttemberg and Bavaria with regard to TBE vaccination and prevention of TBDs and to derive strategies for increasing vaccination rates and improving knowledge about TBE and other TBDs in the population and among primary care physicians. We invited all primary care physicians (N = 14,046) in both states to participate by mail. Using standardized, self-administered questionnaires, available both on paper and online, we asked physicians anonymously about their knowledge, attitudes and behaviors with respect to TBE vaccination and TBD prevention and their need for further information/educational materials. A total of 2321 physicians participated between May and September 2022 (response rate 17%), of whom 1222 (53%) worked in Baden-Wuerttemberg and 1067 (46%) in Bavaria. Among the participating physicians, 56% were male, 71% were >50 years and 51% worked in an individual practice. Furthermore, 91% were aware of the German national vaccination guidelines, and 98% perceived their knowledge of the risks and benefits of vaccination as adequate. A total of 97% offer TBE vaccinations, 67% provide vaccination counselling during initial consultations with new patients and 64% actively remind patients about due vaccinations. In addition, 24% expressed a need for further information materials, mainly traditional, analogue media such as flyers (82%) and posters (50%), and named timeliness, quality assurance, easy comprehensibility and independence from the pharmaceutical industry as the most important characteristics of such materials. Almost all participating physicians reported offering TBE vaccinations and feeling well-informed about TBE vaccination and TBDs. However, active offering of vaccinations and education could be further improved, and additional, low-threshold information materials are needed. Based on these results, we will develop and provide various materials on TBE vaccination and TBDs, in particular flyers and posters, for use by physicians during consultations.
RESUMEN
In November 2018, a tularaemia outbreak occurred in Bavaria, Germany, among participants of a hare hunt and butchery employees handling the hares. We conducted an epidemiological outbreak investigation, including a retrospective cohort study among hunting participants, to identify likely transmission routes and activities associated with infection. Twelve of 41 participants were antibody-positive for Francisella (F.) tularensis (attack rate: 29%). Cases reported influenza-like symptoms (n = 11), lymphadenopathy (n = 1) and conjunctivitis (n = 1). Infection only occurred in those hunting participants present while hares were processed, while risk of infection was highest when directly involved (RR = 10.0; 95%CI: 2.6-392). F. tularensis was isolated from 1/4 hares. Only two individuals reported using some of the recommended personal protective equipment (PPE). Occurrence of mainly non-specific symptoms, likely due to early treatment, was not indicative of a specific transmission route. Transmissions via direct (skin/mucosa) contact and by inhalation of contaminated aerosols seem plausible. Promoting and increasing appropriate use of PPE among people processing hares is crucial to prevent future outbreaks.
Asunto(s)
Francisella tularensis , Liebres , Tularemia , Animales , Brotes de Enfermedades , Alemania/epidemiología , Humanos , Estudios Retrospectivos , Tularemia/epidemiología , Tularemia/veterinariaRESUMEN
The mesenchymal stroma harbors an important population of cells that possess stem cell-like characteristics including self renewal and differentiation capacities and can be derived from a variety of different sources. These multipotent mesenchymal stem cells (MSC) can be found in nearly all tissues and are mostly located in perivascular niches. MSC have migratory abilities and can secrete protective factors and act as a primary matrix for tissue regeneration during inflammation, tissue injuries and certain cancers.These functions underlie the important physiological roles of MSC and underscore a significant potential for the clinical use of distinct populations from the various tissues. MSC derived from different adult (adipose tissue, peripheral blood, bone marrow) and neonatal tissues (particular parts of the placenta and umbilical cord) are therefore compared in this mini-review with respect to their cell biological properties, surface marker expression and proliferative capacities. In addition, several MSC functions including in vitro and in vivo differentiation capacities within a variety of lineages and immune-modulatory properties are highlighted. Differences in the extracellular milieu such as the presence of interacting neighbouring cell populations, exposure to proteases or a hypoxic microenvironment contribute to functional developments within MSC populations originating from different tissues, and intracellular conditions such as the expression levels of certain micro RNAs can additionally balance MSC function and fate.