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1.
Microbiol Spectr ; 12(2): e0239723, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38189291

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic demonstrated the need for accurate diagnostic testing for the early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although the pandemic has ended, accurate assays are still needed to monitor viral spread at national levels and beyond through population and wastewater surveillance. To enhance early detection, SARS-CoV-2 assays should have high diagnostic accuracy and should be validated to assure accurate results. Three distinct SARS-CoV-2 assays were evaluated with clinical samples using the VALCOR (VALidation of SARS-CORona Virus-2 assays) framework, with the TaqPath COVID-19 assay (ThermoFisher Scientific, USA) as a comparator. We evaluated clinical sensitivity, specificity, limit of detection (LOD), and overall concordance between comparator and three index Allplex SARS-CoV-2 assays (Seegene, South Korea): Allplex-SC2, Allplex-SC2Fast (Fast PCR), and Allplex-SC2FabR (SARS-CoV-2/FluA/FluB/respiratory syncytial virus). Analytical performance and LOD of index assays were assessed using a dilution series of three synthetic SARS-CoV-2 sequence reference materials (RMs). Ninety SARS-CoV-2 positives and 90 SARS-CoV-2 negatives were tested. All Allplex assays had 100.0% sensitivity (95%CI = 95.9%-100.0%). Allplex-SC2 and Allplex-SC2Fast assays had 97.8% specificity (95%CI = 92.3%-99.7%) and 98.9% overall concordance [κ = 0.978 (95%CI = 0.947-1.000)]. Allplex-SC2FabR assay showed 100.0% specificity (95%CI = 95.9%-100.0%) and 100.0% overall concordance [κ = 1.000 (95%CI = 1.000-1.000)]. LOD assessment of index assays revealed detection down to 2.61 × 102 copies/mL in clinical samples, while the analytical LOD was 9.00 × 102 copies/mL. In conclusion, the evaluation of the three Seegene Allplex SARS-CoV-2 assays showed high sensitivity and specificity and an overall good assay concordance with the comparator. The assays showed low analytical LOD using RM and even a slightly lower LOD in clinical samples. Non-overlapping target gene sequences between SARS-CoV-2 assays and RMs emphasize the need for aligning targeted sequences of diagnostic assays and RMs.IMPORTANCEThe coronavirus disease 2019 pandemic has a significant impact on global public health, economies, and societies. As shown through the first phases of the pandemic, accurate and timely diagnosis is crucial for disease control, prevention, and monitoring. Though the pandemic phase of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has concluded, diagnostic assays remain in demand to monitor SARS-CoV-2 at the individual patient level, regionally, and nationally, as well as to remain an infectious disease preparedness instrument to monitor any new SARS-CoV-2 dissemination across borders using population and wastewater surveillance. The anticipation by WHO and central health care policy entities such as the Center for Disease Control, EMA, and multiple national health authorities is that SARS-CoV-2 will reside as an endemic respiratory disease for years to come. The key strategic consideration is hence shifting from combating a pandemic situation with a high number of patients to instead allowing precise diagnostics of suspected patients with the intention of correct management in a low-prevalence setting.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Águas Residuárias , Sensibilidade e Especificidade , Vigilância Epidemiológica Baseada em Águas Residuárias
2.
Skeletal Radiol ; 53(2): 401-406, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37556017

RESUMO

Primary lymphoma of the bone (PLB) is a rare entity, with a majority of pediatric cases presenting in the metaphysis of long bones. There have been only seven reported cases to date of pediatric lymphoma of the bone arising from the epiphysis, of which only two have been described in the proximal tibia. We report a pediatric case of PLB in the tibial epiphysis which presented initially with knee pain. Imaging was performed with X-ray, MRI, CT, and PET-CT with bone biopsies revealing diffuse large B-cell lymphoma. This patient also showed a second, synchronous lesion in the left iliac bone, which was also biopsy proven to diffuse large B-cell lymphoma. Lymphoma in the epiphysis for children is rare and often confused with infectious etiologies or other types of tumors. Misdiagnosis may result in inappropriate treatment and possible progression of the disease, thus making early identification important to initiate therapy.


Assuntos
Linfoma Difuso de Grandes Células B , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Humanos , Criança , Linfoma Difuso de Grandes Células B/diagnóstico por imagem , Linfoma Difuso de Grandes Células B/patologia , Radiografia , Epífises/diagnóstico por imagem , Epífises/patologia , Imageamento por Ressonância Magnética
3.
J Neurosurg ; : 1-8, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38064694

RESUMO

OBJECTIVE: Olfactory groove meningiomas (OGMs) often require surgical removal. The introduction of recent keyhole approaches raises the question of whether these tumors may be better treated through a smaller cranial opening. One such approach, the supraorbital keyhole craniotomy, has never been compared with more traditional open transcranial approaches with regard to outcome. In this study, the authors compared clinical, radiographic, and functional quality of life (QOL) outcomes between the keyhole supraorbital approach (SOA) and traditional transcranial approach (TTA) for OGMs. They sought to examine the potential advantages and disadvantages of open/TTA versus keyhole SOA for the resection of OGMs in a relatively case-matched series of patients. METHODS: A retrospective, single-institution review of 57 patients undergoing a keyhole SOA or larger traditional transcranial (frontotemporal, pterional, or bifrontal) craniotomy for newly diagnosed OGMs between 2005 and 2023 was performed. Extent of resection, olfaction, length of stay (LOS), radiographic volumetric assessment of postoperative vasogenic and cytotoxic edema, and QOL (using the Anterior Skull Base Questionnaire) were assessed. RESULTS: Thirty-two SOA and 25 TTA patients were included. The mean EOR was not significantly different by approach (TTA: 99.1% vs SOA: 98.4%, p = 0.91). Olfaction was preserved or improved at similar rates (TTA: 47% vs SOA: 43%, p = 0.99). The mean LOS was significantly shorter for SOA patients (4.1 ± 2.8 days) than for TTA patients (9.4 ± 11.2 days) (p = 0.002). The authors found an association between an increase in postoperative FLAIR cerebral edema and TTA (p = 0.031). QOL as assessed by the ASQB at last follow-up did not differ significantly between groups (p = 0.74). CONCLUSIONS: The keyhole SOA was associated with a statistically significant decrease in LOS and less postoperative edema relative to traditional open approaches.

4.
J Med Virol ; 95(9): e29093, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37702556

RESUMO

The implementation of cervical screening based on human papillomavirus (HPV) continues to progress rapidly across countries. Evidence has shown that assays detecting high-risk human papillomavirus (hrHPV) deoxyribonucleic acid (DNA) are more effective than cytology-based screening. Validation of new hrHPV DNA assays requires both noninferior clinical accuracy compared to a standard comparator for cervical precancer and good reproducibility. This study builds upon previous diagnostic accuracy assessments of the RIATOL HPV genotyping qPCR assay and aims to evaluate the international validation criteria for reproducibility. The intra- and interreproducibility of the RIATOL-qPCR assay were assessed using 550 remnant cervical cell material from the cytology archive of the National Reference Center for HPV in Belgium. Specimens were collected in the context of cervical cancer screening and tested in two different laboratories. The international reproducibility criteria include the lower bound of 95% confidence interval of the intra- and interlaboratory agreement regarding the detection of hrHPV DNA exceeding 87% with kappa ≥0.50. The RIATOL-qPCR assay demonstrated excellent intralaboratory reproducibility, achieving an overall agreement of 98.2 (95% CI 96.6-99.1%) and a kappa of 0.96. Interlaboratory testing showed an overall agreement of 98.5 (95% CI 97.1-99.4%) with a kappa of 0.97. The RIATOL-qPCR assay fulfills the third criterion for HPV test reproducibility requirement for use in cervical cancer screening.


Assuntos
Infecções por Papillomavirus , Neoplasias do Colo do Útero , Humanos , Feminino , Detecção Precoce de Câncer , Neoplasias do Colo do Útero/diagnóstico , Genótipo , Infecções por Papillomavirus/diagnóstico , Reprodutibilidade dos Testes , Papillomaviridae/genética , Papillomavirus Humano , DNA
5.
Am J Perinatol ; 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37429320

RESUMO

OBJECTIVE: Our objective was to characterize the incidence, associated clinical factors, timing of infection, microbiology, and incidence of concordant blood culture of urinary tract infections (UTIs) in very low birth weight (VLBW <1,500g) infants. STUDY DESIGN: Multicenter observational cohort study of VLBW infants with gestational age (GA) ≤32 weeks, still hospitalized on postnatal day 7, and discharged 2010 to 2018 from Pediatrix Medical Group neonatal intensive care units. Demographic and clinical characteristics of infants with and without UTI were compared. Multivariable logistic regression evaluated adjusted odds of UTI diagnosis. RESULTS: Of 86,492 included infants, 5,988 (7%) had a UTI. The most common pathogen was Enterococcus spp. (20%), followed by Escherichia coli (19%) and Klebsiella spp. (18%). Candida spp. (6%) was the most common nonbacterial pathogen. Concordant-positive blood culture was present in 8% of infants with UTI diagnoses. UTI was associated with lower GA, male sex, vaginal delivery, prenatal steroid exposure, and longer duration of hospitalization. CONCLUSION: UTI is a common cause of infection in VLBW infants, especially among the smallest, most premature, male infants, and those with a longer duration of hospitalization. Neonatal clinicians should consider obtaining urine culture in the setting of late-onset sepsis evaluations in VLBW infants. KEY POINTS: · UTI is a common cause of LOS in VLBW infants.. · The most common pathogens are Enterococcus spp. and E. coli.. · UTI risk varies among different VLBW infant populations.. · Next steps should include evaluation of preventative measures..

6.
Euro Surveill ; 28(26)2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37382885

RESUMO

BackgroundThe Belgian COVID-19 vaccination campaign aimed to reduce disease spread and severity.AimWe estimated SARS-CoV-2 variant-specific vaccine effectiveness against symptomatic infection (VEi) and hospitalisation (VEh), given time since vaccination and prior infection.MethodsNationwide healthcare records from July 2021 to May 2022 on testing and vaccination were combined with a clinical hospital survey. We used a test-negative design and proportional hazard regression to estimate VEi and VEh, controlling for prior infection, time since vaccination, age, sex, residence and calendar week of sampling.ResultsWe included 1,932,546 symptomatic individuals, of whom 734,115 tested positive. VEi against Delta waned from an initial estimate of 80% (95% confidence interval (CI): 80-81) to 55% (95% CI: 54-55) 100-150 days after the primary vaccination course. Booster vaccination increased initial VEi to 85% (95% CI: 84-85). Against Omicron, an initial VEi of 33% (95% CI: 30-36) waned to 17% (95% CI: 15-18), while booster vaccination increased VEi to 50% (95% CI: 49-50), which waned to 20% (95% CI: 19-21) 100-150 days after vaccination. Initial VEh for booster vaccination decreased from 96% (95% CI: 95-96) against Delta to 87% (95% CI: 86-89) against Omicron. VEh against Omicron waned to 73% (95% CI: 71-75) 100-150 days after booster vaccination. While recent prior infections conferred higher protection, infections occurring before 2021 remained associated with significant risk reduction against symptomatic infection. Vaccination and prior infection outperformed vaccination or prior infection only.ConclusionWe report waning and a significant decrease in VEi and VEh from Delta to Omicron-dominant periods. Booster vaccination and prior infection attenuated these effects.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , SARS-CoV-2 , Bélgica/epidemiologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , Eficácia de Vacinas , Hospitalização
7.
J Med Virol ; 95(1): e28417, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36541733

RESUMO

Human papillomavirus (HPV) assays used in cervical cancer screening should be clinically validated according to international criteria. OncoPredict HPV® Screening (SCR) is a partial genotyping multiplex real-time PCR assay targeting E6/E7 genes of 13 high-risk (hr) HPVs. OncoPredict HPV® SCR (index assay) identifies HPV-16 and HPV-18 separately, 11 other hrHPV in aggregate and includes quality controls for sample adequacy, DNA extraction efficiency and PCR inhibition. 1300 VALGENT-2 study samples (from women aged 20-60 attending the Scottish cervical cancer screening program) were tested with the index assay and the GP5+/6+ PCR enzyme immunoassay (standard comparator assay). Non-inferior accuracy detecting cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) of the index versus comparator was verified. Intra- and interlaboratory reproducibility of the index was evaluated by overall concordance and Cohen's kappa, using a sub-population (n = 526). Relative sensitivity and specificity for CIN2+ of the index versus comparator were 1.01 (95% confidence interval [CI]: 0.99-1.03) and 1.02 (95% CI: 1.0-1.04), respectively. Noninferiority p values were all ≤0.05, except for CIN3+ in patients ≥30 years. Excellent intra- and interlaboratory reproducibility was shown with concordance >98% and kappas >0.95. OncoPredict HPV® SCR fulfills the three international validation criteria for hrHPV DNA tests in cervical cancer screening.


Assuntos
Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/diagnóstico , Papillomavirus Humano , Técnicas de Genotipagem , Infecções por Papillomavirus/diagnóstico , Detecção Precoce de Câncer , Reprodutibilidade dos Testes , Papillomaviridae/genética , Sensibilidade e Especificidade , Reação em Cadeia da Polimerase em Tempo Real
8.
Nat Struct Mol Biol ; 29(11): 1113-1121, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36352138

RESUMO

The addition of poly(UG) ('pUG') repeats to 3' termini of mRNAs drives gene silencing and transgenerational epigenetic inheritance in the metazoan Caenorhabditis elegans. pUG tails promote silencing by recruiting an RNA-dependent RNA polymerase (RdRP) that synthesizes small interfering RNAs. Here we show that active pUG tails require a minimum of 11.5 repeats and adopt a quadruplex (G4) structure we term the pUG fold. The pUG fold differs from known G4s in that it has a left-handed backbone similar to Z-RNA, no consecutive guanosines in its sequence, and three G quartets and one U quartet stacked non-sequentially. The compact pUG fold binds six potassium ions and brings the RNA ends into close proximity. The biological importance of the pUG fold is emphasized by our observations that porphyrin molecules bind to the pUG fold and inhibit both gene silencing and binding of RdRP. Moreover, specific 7-deaza substitutions that disrupt the pUG fold neither bind RdRP nor induce RNA silencing. These data define the pUG fold as a previously unrecognized RNA structural motif that drives gene silencing. The pUG fold can also form internally within larger RNA molecules. Approximately 20,000 pUG-fold sequences are found in noncoding regions of human RNAs, suggesting that the fold probably has biological roles beyond gene silencing.


Assuntos
Proteínas de Caenorhabditis elegans , Inativação Gênica , Humanos , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , RNA Polimerase Dependente de RNA
10.
Radiol Case Rep ; 17(9): 2960-2962, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35755119

RESUMO

Desmoid tumors are rare soft tissue tumors with slow growth and high recurrence rates. They typically arise sporadically in the abdominal wall or retroperitoneum, with a few rare cases reported after trauma and surgery. Postoperative desmoid tumors in adults are very rare with only 7 reported cases involving the paraspinal location. This is the first reported case of a male patient with a postoperative paraspinal desmoid tumor.

11.
Viruses ; 14(6)2022 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-35746768

RESUMO

This retrospective multi-center matched cohort study assessed the risk for severe COVID-19 (combination of severity indicators), intensive care unit (ICU) admission, and in-hospital mortality in hospitalized patients when infected with the Omicron variant compared to when infected with the Delta variant. The study is based on a causal framework using individually-linked data from national COVID-19 registries. The study population consisted of 954 COVID-19 patients (of which, 445 were infected with Omicron) above 18 years old admitted to a Belgian hospital during the autumn and winter season 2021-2022, and with available viral genomic data. Patients were matched based on the hospital, whereas other possible confounders (demographics, comorbidities, vaccination status, socio-economic status, and ICU occupancy) were adjusted for by using a multivariable logistic regression analysis. The estimated standardized risk for severe COVID-19 and ICU admission in hospitalized patients was significantly lower (RR = 0.63; 95% CI (0.30; 0.97) and RR = 0.56; 95% CI (0.14; 0.99), respectively) when infected with the Omicron variant, whereas in-hospital mortality was not significantly different according to the SARS-CoV-2 variant (RR = 0.78, 95% CI (0.28-1.29)). This study demonstrates the added value of integrated genomic and clinical surveillance to recognize the multifactorial nature of COVID-19 pathogenesis.


Assuntos
COVID-19 , SARS-CoV-2 , Adolescente , Bélgica/epidemiologia , COVID-19/epidemiologia , Estudos de Coortes , Humanos , Estudos Retrospectivos , SARS-CoV-2/genética , Estações do Ano
12.
Cardiovasc Intervent Radiol ; 45(5): 578-581, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34859308

RESUMO

This retrospective analysis reviews five patients with transjugular intrahepatic portosystemic shunt (TIPS) who underwent percutaneous microwave ablation of hepatocellular carcinoma between January 2017 and September 2020. Mean tumor diameter was 2.0 cm (range 1.3-2.9 cm), and mean tumor distance from TIPS was 2.3 cm (range 1.5-3.3 cm). There were no major adverse events, and the TIPS patency was 100% post-ablation. The technical success rate was 100%, and the complete response rate was 100%. In this small study, percutaneous microwave ablation appears safe and effective for the treatment of hepatocellular carcinoma in patients with TIPS in the short-term follow-up period.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Derivação Portossistêmica Transjugular Intra-Hepática , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/cirurgia , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/cirurgia , Micro-Ondas/uso terapêutico , Derivação Portossistêmica Transjugular Intra-Hepática/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento
13.
Vaccines (Basel) ; 11(1)2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36679859

RESUMO

We aimed to investigate vaccine effectiveness against progression to severe COVID-19 (acute respiratory distress syndrome (ARDS), intensive care unit (ICU) admission and/or death) and in-hospital death in a cohort of hospitalized COVID-19 patients. Mixed effects logistic regression analyses were performed to estimate the association between receiving a primary COVID-19 vaccination schedule and severe outcomes after adjusting for patient, hospital, and vaccination characteristics. Additionally, the effects of the vaccine brands including mRNA vaccines mRNA-1273 and BNT162b2, and adenovirus-vector vaccines ChAdOx1 (AZ) and Ad26.COV2.S (J&J) were compared to each other. This retrospective, multicenter cohort study included 2493 COVID-19 patients hospitalized across 73 acute care hospitals in Belgium during the time period 15 August 2021-14 November 2021 when the Delta variant (B1.617.2) was predominant. Hospitalized COVID-19 patients that received a primary vaccination schedule had lower odds of progressing to severe disease (OR (95% CI); 0.48 (0.38; 0.60)) and in-hospital death (OR (95% CI); 0.49 (0.36; 0.65)) than unvaccinated patients. Among the vaccinated patients older than 75 years, mRNA vaccines and AZ seemed to confer similar protection, while one dose of J&J showed lower protection in this age category. In conclusion, a primary vaccination schedule protects against worsening of COVID-19 to severe outcomes among hospitalized patients.

14.
Radiol Case Rep ; 16(8): 2035-2037, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34158887

RESUMO

Gastric variceal (GV) bleeding is an important and fatal complication for cirrhotic patients which has historically been controlled with sclerosants and band ligation. Cyanoacrylate glue therapy has emerged as a more favorable option with bleeding control of up to 90% and low complication rates; however, several reports show possible ectopic systemic glue migration, most commonly into the portomesenteric system and leading to portal hypertension. To decompress portal pressures and mitigate future complications, transjugular intrahepatic portosystemic shunt (TIPS) placement may be a viable rescue therapy. We present two cases of TIPS placement for an 18-year-old and 51-year-old male in the setting of endoscopic glue migration into the portomesenteric system that demonstrate feasibility and success in temporizing acute variceal bleeding. Both cases demonstrated decompressing portovenous pressures but may result in need for re-intervention.

15.
Vet Radiol Ultrasound ; 62(6): 666-673, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34086380

RESUMO

The aim of this retrospective observational study was to characterize the MRI appearance of retinal detachment (RD) in a sample of dogs and cats. Study inclusion was based on the following medical record criteria: (a) had a diagnosis of RD in at least one eye by either funduscopic examination or ocular ultrasound and had an MRI evaluation including the eyes, or (b) had a diagnosis of RD documented in an MRI report for at least one eye and also had a clinical eye examination. Eighteen patients (12 dogs, 6 cats) and 35 eyes met the inclusion criteria, although four eyes that were clinically examined could not be visualized funduscopically and did not have ocular ultrasound performed (criterion 2). The MRI and clinical diagnosis (via either funduscopy or ultrasound) of RD/no RD was concordant in 27 of 31 eyes (87%). Qualitatively, RD appeared as a variable intensity curvilinear structure located internal and adjacent to the sclera on all sequences and was best delineated on T2W sequences. RDs inconsistently contrast enhanced and, although there was no statistical difference, subjectively appeared more clearly delineated on dorsal and parasagittal images. In conclusion, findings from the current study support using MRI as an ancillary diagnostic test for confirmation or further characterization of RD in dogs and cats.


Assuntos
Doenças do Gato , Doenças do Cão , Descolamento Retiniano , Animais , Doenças do Gato/diagnóstico por imagem , Gatos , Doenças do Cão/diagnóstico por imagem , Cães , Imageamento por Ressonância Magnética/veterinária , Descolamento Retiniano/diagnóstico por imagem , Descolamento Retiniano/veterinária
17.
Genetics ; 216(4): 1071-1085, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33055090

RESUMO

Small regulatory RNAs, such as small interfering RNAs (siRNAs) and PIWI-interacting RNAs, regulate splicing, transcription, and genome integrity in many eukaryotes. In Caenorhabditis elegans, siRNAs bind nuclear Argonautes (AGOs), which interact with homologous premessenger RNAs to recruit downstream silencing effectors, such as NRDE-2, to direct cotranscriptional gene silencing [or nuclear RNA interference (RNAi)]. To further our understanding of the mechanism of nuclear RNAi, we conducted immunoprecipitation-mass spectrometry on C. elegans NRDE-2 The major NRDE-2 interacting protein identified was the RNA helicase MTR-4 Co-immunoprecipitation analyses confirmed a physical association between NRDE-2 and MTR-4 MTR-4 colocalizes with NRDE-2 within the nuclei of most/all C. elegans somatic and germline cells. MTR-4 is required for nuclear RNAi, and interestingly, MTR-4 is recruited to premessenger RNAs undergoing nuclear RNAi via a process requiring nuclear siRNAs, the nuclear AGO HRDE-1, and NRDE-2, indicating that MTR-4 is a component of the C. elegans nuclear RNAi machinery. Finally, we confirm previous reports showing that human (Hs)NRDE2 and HsMTR4 also physically interact. Our data show that the NRDE-2/MTR-4 interactions are evolutionarily conserved, and that, in C. elegans, the NRDE-2/MTR-4 complex contributes to siRNA-directed cotranscriptional gene silencing.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Sequência Conservada , Inativação Gênica , Células HEK293 , Humanos , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética
18.
Nature ; 582(7811): 283-288, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32499657

RESUMO

Mobile genetic elements threaten genome integrity in all organisms. RDE-3 (also known as MUT-2) is a ribonucleotidyltransferase that is required for transposon silencing and RNA interference in Caenorhabditis elegans1-4. When tethered to RNAs in heterologous expression systems, RDE-3 can add long stretches of alternating non-templated uridine (U) and guanosine (G) ribonucleotides to the 3' termini of these RNAs (designated poly(UG) or pUG tails)5. Here we show that, in its natural context in C. elegans, RDE-3 adds pUG tails to targets of RNA interference, as well as to transposon RNAs. RNA fragments attached to pUG tails with more than 16 perfectly alternating 3' U and G nucleotides become gene-silencing agents. pUG tails promote gene silencing by recruiting RNA-dependent RNA polymerases, which use pUG-tailed RNAs (pUG RNAs) as templates to synthesize small interfering RNAs (siRNAs). Our results show that cycles of pUG RNA-templated siRNA synthesis and siRNA-directed pUG RNA biogenesis underlie double-stranded-RNA-directed transgenerational epigenetic inheritance in the C. elegans germline. We speculate that this pUG RNA-siRNA silencing loop enables parents to inoculate progeny against the expression of unwanted or parasitic genetic elements.


Assuntos
Caenorhabditis elegans/genética , Caenorhabditis elegans/parasitologia , Epigênese Genética/genética , Genoma/genética , Hereditariedade , Poli G/genética , Poli U/genética , RNA Mensageiro/genética , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Células Germinativas/citologia , Células Germinativas/metabolismo , Masculino , Nucleotidiltransferases/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Polimerase Dependente de RNA/metabolismo , Moldes Genéticos
20.
Cell Rep ; 28(9): 2317-2330.e8, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31461649

RESUMO

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor and bi-functional lipid and protein phosphatase. We report that the metabolic regulator pyruvate dehydrogenase kinase1 (PDHK1) is a synthetic-essential gene in PTEN-deficient cancer and normal cells. The PTEN protein phosphatase dephosphorylates nuclear factor κB (NF-κB)-activating protein (NKAP) and limits NFκB activation to suppress expression of PDHK1, a NF-κB target gene. Loss of the PTEN protein phosphatase upregulates PDHK1 to induce aerobic glycolysis and PDHK1 cellular dependence. PTEN-deficient human tumors harbor increased PDHK1, a biomarker of decreased patient survival. This study uncovers a PTEN-regulated signaling pathway and reveals PDHK1 as a potential target in PTEN-deficient cancers.


Assuntos
Neoplasias/metabolismo , PTEN Fosfo-Hidrolase/genética , Piruvato Desidrogenase Quinase de Transferência de Acetil/genética , Animais , Linhagem Celular Tumoral , Feminino , Glicólise , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , NF-kappa B/metabolismo , Neoplasias/genética , Neoplasias/patologia , PTEN Fosfo-Hidrolase/economia , PTEN Fosfo-Hidrolase/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil/metabolismo , Proteínas Repressoras/metabolismo
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