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1.
J Infect Dis ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38636496

RESUMO

Respiratory syncytial virus (RSV) causes severe infections in infants, immunocompromised or elderly individuals resulting in annual epidemics of respiratory disease. Currently, limited clinical surveillance and the lack of predictable seasonal dynamics limits the public health response. Wastewater-based epidemiology (WBE) has recently been used globally as a key metric in determining prevalence of SARS-CoV-2 in the community but its application to other respiratory viruses is limited. In this study, we present an integrated genomic WBE approach, applying RT-qPCR and partial G-gene sequencing to track RSV levels and variants in the community. We report increasing detection of RSV in wastewater concomitant with increasing numbers of positive clinical cases. Analysis of wastewater-derived RSV sequences permitted identification of distinct circulating lineages within and between seasons. Altogether, our genomic WBE platform has the potential to complement ongoing global surveillance and aid the management of RSV by informing the timely deployment of pharmaceutical and non-pharmaceutical interventions.

2.
Cell Rep ; 42(7): 112778, 2023 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-37453058

RESUMO

The regulatory effect of non-coding large-scale structural variations (SVs) on proto-oncogene activation remains unclear. This study investigated SV-mediated gene dysregulation by profiling 3D cancer genome maps from 40 patients with colorectal cancer (CRC). We developed a machine learning-based method for spatial characterization of the altered 3D cancer genome. This revealed a frequent establishment of "de novo chromatin contacts" that can span multiple topologically associating domains (TADs) in addition to the canonical TAD fusion/shuffle model. Using this information, we precisely identified super-enhancer (SE)-hijacking and its clonal characteristics. Clonal SE-hijacking genes, such as TOP2B, are recurrently associated with cell-cycle/DNA-processing functions, which can potentially be used as CRC prognostic markers. Oncogene activation and increased drug resistance due to SE-hijacking were validated by reconstructing the patient's SV using CRISPR-Cas9. Collectively, the spatial and clonality-resolved analysis of the 3D cancer genome reveals regulatory principles of large-scale SVs in oncogene activation and their clinical implications.


Assuntos
Neoplasias Colorretais , Genoma , Humanos , Prognóstico , Cromatina , DNA , Neoplasias Colorretais/genética
3.
Lett Appl Microbiol ; 76(6)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37133410

RESUMO

Wastewater Based Epidemiology (WBE) has become an integral part of the public health effort to track the levels of SARS-CoV-2 within communities. Detection of SARS-CoV-2 in wastewater can be challenging due to relatively low levels of virus within the sample. The wastewater matrix is also comprised of commercial and domestically derived contaminants, as well as RNases, all of which can adversely affect RT-qPCR analysis. To improve SARS-CoV-2 detection within wastewater samples we investigated both the effect of template dilution (as a means to reduce RT-qPCR inhibition) and sample stabilisation via addition of DNA/RNA Shield™ and/or RNA Later™ (to prevent RNA degradation via RNases) as a means to improve viral fragment detection. Using both methodologies, a significant improvement in SARS-CoV-2 detection from wastewater samples was observed. No adverse effects of stabilising agent addition on downstream Next-Generation Sequencing workflows were detected.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Excipientes , Águas Residuárias , RNA , RNA Viral/genética
4.
Chest ; 164(3): 625-636, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37011709

RESUMO

BACKGROUND: Epstein-Barr virus (EBV) frequently is measured at high levels in COPD using sputum quantitative polymerase chain reaction, whereas airway immunohistochemistry analysis has shown EBV detection to be common in severe disease. RESEARCH QUESTION: Is valaciclovir safe and effective for EBV suppression in COPD? STUDY DESIGN AND METHODS: The Epstein-Barr Virus Suppression in COPD (EViSCO) trial was a randomized double-blind placebo-controlled trial conducted at the Mater Hospital Belfast, Northern Ireland. Eligible patients had stable moderate-to-severe COPD and sputum EBV (measured using quantitative polymerase chain reaction) and were assigned randomly (1:1) to valaciclovir (1 g tid) or matching placebo for 8 weeks. The primary efficacy outcome was sputum EBV suppression (defined as ≥ 90% sputum viral load reduction) at week 8. The primary safety outcome was the incidence of serious adverse reactions. Secondary outcome measures were FEV1 and drug tolerability. Exploratory outcomes included changes in quality of life, sputum cell counts, and cytokines. RESULTS: From November 2, 2018, through March 12, 2020, 84 patients were assigned randomly (n = 43 to valaciclovir). Eighty-one patients completed trial follow-up and were included in the intention-to-treat analysis of the primary outcome. A greater number of participants in the valaciclovir group achieved EBV suppression (n = 36 [87.8%] vs n = 17 [42.5%]; P < .001). Valaciclovir was associated with a significant reduction in sputum EBV titer compared with placebo (-90,404 copies/mL [interquartile range, -298,000 to -15,200 copies/mL] vs -3,940 copies/mL [interquartile range, -114,400 to 50,150 copies/mL]; P = .002). A statistically nonsignificant 24-mL numerical FEV1 increase was shown in the valaciclovir group (difference, -44 mL [95% CI, -150 to 62 mL]; P = .41). However, a reduction in sputum white cell count was noted in the valaciclovir group compared with the placebo group (difference, 2.89 [95% CI, 1.5 × 106-7.4 × 106]; P = .003). INTERPRETATION: Valaciclovir is safe and effective for EBV suppression in COPD and may attenuate the sputum inflammatory cell infiltrate. The findings from the current study provide support for a larger trial to evaluate long-term clinical outcomes. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03699904; URL: www. CLINICALTRIALS: gov.


Assuntos
Infecções por Vírus Epstein-Barr , Doença Pulmonar Obstrutiva Crônica , Humanos , Valaciclovir/uso terapêutico , Herpesvirus Humano 4 , Qualidade de Vida , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Método Duplo-Cego , Resultado do Tratamento
5.
Sci Adv ; 9(15): eabo2467, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-37058563

RESUMO

Parkinson's disease (PD) is a progressive neurodegenerative disorder. However, cell type-dependent transcriptional regulatory programs responsible for PD pathogenesis remain elusive. Here, we establish transcriptomic and epigenomic landscapes of the substantia nigra by profiling 113,207 nuclei obtained from healthy controls and patients with PD. Our multiomics data integration provides cell type annotation of 128,724 cis-regulatory elements (cREs) and uncovers cell type-specific dysregulations in cREs with a strong transcriptional influence on genes implicated in PD. The establishment of high-resolution three-dimensional chromatin contact maps identifies 656 target genes of dysregulated cREs and genetic risk loci, uncovering both potential and known PD risk genes. Notably, these candidate genes exhibit modular gene expression patterns with unique molecular signatures in distinct cell types, highlighting altered molecular mechanisms in dopaminergic neurons and glial cells including oligodendrocytes and microglia. Together, our single-cell transcriptome and epigenome reveal cell type-specific disruption in transcriptional regulations related to PD.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/metabolismo , Multiômica , Perfilação da Expressão Gênica , Neurônios Dopaminérgicos/metabolismo , Transcriptoma
6.
Heliyon ; 9(3): e14039, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36915530

RESUMO

Several studies have identified mutations in neuroprotective genes in a few cases of Parkinson's disease (PD); however, the role of alternative splicing changes in PD remains unelucidated. Based on the transcriptome analysis of substantia nigra (SN) tissues obtained from PD cases and age-matched healthy controls, we identified a novel alternative splicing variant of DJ-1, lacking exon 6 (DJ-1 ΔE6), frequently detected in the SN of patients with PD. We found that the exon 6 skipping of DJ-1 induces mitochondrial dysfunction and impaired antioxidant capability. According to an in silico modeling study, the exon 6 skipping of DJ-1 disrupts the structural state suitable for the oxidation of the cysteine 106 residue that is a prerequisite for activating its neuroprotective roles. Our results suggest that change in DJ-1 alternative splicing may contribute to PD progression and provide an insight for studying PD etiology and its potential therapeutic targets.

7.
Exp Mol Med ; 54(10): 1756-1765, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36229591

RESUMO

Clonal hematopoiesis of indeterminate potential (CHIP), a common aging-related process that predisposes individuals to various inflammatory responses, has been reported to be associated with COVID-19 severity. However, the immunological signature and the exact gene expression program by which the presence of CHIP exerts its clinical impact on COVID-19 remain to be elucidated. In this study, we generated a single-cell transcriptome landscape of severe COVID-19 according to the presence of CHIP using peripheral blood mononuclear cells. Patients with CHIP exhibited a potent IFN-γ response in exacerbating inflammation, particularly in classical monocytes, compared to patients without CHIP. To dissect the regulatory mechanism of CHIP (+)-specific IFN-γ response gene expression in severe COVID-19, we identified DNMT3A CHIP mutation-dependent differentially methylated regions (DMRs) and annotated their putative target genes based on long-range chromatin interactions. We revealed that CHIP mutant-driven hypo-DMRs at poised cis-regulatory elements appear to facilitate the CHIP (+)-specific IFN-γ-mediated inflammatory immune response. Our results highlight that the presence of CHIP may increase the susceptibility to hyperinflammation through the reorganization of chromatin architecture, establishing a novel subgroup of severe COVID-19 patients.


Assuntos
COVID-19 , Hematopoiese Clonal , Humanos , Transcriptoma , Hematopoese/genética , COVID-19/genética , Leucócitos Mononucleares , Mutação , Cromatina/genética , Perfilação da Expressão Gênica
9.
Pharmacogenomics ; 23(3): 173-182, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35042388

RESUMO

Aim: To evaluate the effect of pharmacogenomics (PGx) education for pharmacists. Materials & Methods: Three-part weekly webinar series occurred in 2021. Pharmacists were assessed on their PGx knowledge at baseline and after each webinar. The primary end point was a change in the percent of correct responses between the baseline and week 1 assessment. Secondary end points included change in knowledge at weeks 4-8 and change in self-efficacy. Results: In total, 19 of 58 participants were eligible for the primary analysis, which showed an average improvement of 37% (p < 0.0001). Knowledge remained consistent between week 1 and weeks 4-8. Average self-efficacy increased (p < 0.0001) and was maintained at weeks 4-8. Conclusion: The PGx webinar series resulted in a lasting improvement in PGx knowledge and self-efficacy.


Assuntos
Educação em Farmácia , Farmacogenética/educação , Desempenho Acadêmico , Adulto , Educação a Distância/métodos , Educação em Farmácia/métodos , Avaliação Educacional , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Farmacêuticos/estatística & dados numéricos , Adulto Jovem
10.
NAR Genom Bioinform ; 4(4): lqac095, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36601579

RESUMO

Genetic differences inferred from sequencing reads can be used for demultiplexing of pooled single-cell RNA-seq (scRNA-seq) data across multiple donors without WGS-based reference genotypes. However, such methods could not be directly applied to single-cell ATAC-seq (scATAC-seq) data owing to the lower read coverage for each variant compared to scRNA-seq. We propose a new software, scATAC-seq Variant-based EstimatioN for GEnotype ReSolving (scAVENGERS), which resolves this issue by calling more individual-specific germline variants and using an optimized mixture model for the scATAC-seq. The benchmark conducted with three synthetic multiplexed scATAC-seq datasets of peripheral blood mononuclear cells and prefrontal cortex tissues showed outstanding performance compared to existing methods in terms of accuracy, doublet detection, and a portion of donor-assigned cells. Furthermore, analyzing the effect of the improved sections provided insight into handling pooled single-cell data in the future. Our source code of the devised software is available at GitHub: https://github.com/kaistcbfg/scAVENGERS.

11.
Heart Fail Rev ; 27(3): 755-766, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33495937

RESUMO

Obesity is a growing worldwide epidemic with significant economic burden that carries with it impacts on every physiologic system including the cardiovascular system. Specifically, the risk of heart failure has been shown to increase dramatically in obese individuals. The purpose of this review is to provide background on the individual burdens of heart failure and obesity, followed by exploring proposed physiologic mechanisms that interconnect these conditions, and furthermore introduce treatment strategies for weight loss focusing on bariatric surgery. Review of the existing literature on patients with obesity and heart failure who have undergone bariatric surgery is presented, compared, and contrasted.


Assuntos
Cirurgia Bariátrica , Insuficiência Cardíaca , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/cirurgia , Humanos , Obesidade/complicações , Obesidade/cirurgia , Redução de Peso
12.
Mol Cells ; 44(11): 805-829, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34764232

RESUMO

CCCTC-binding factor (CTCF) critically contributes to 3D chromatin organization by determining topologically associated domain (TAD) borders. Although CTCF primarily binds at TAD borders, there also exist putative CTCF-binding sites within TADs, which are spread throughout the genome by retrotransposition. However, the detailed mechanism responsible for masking the putative CTCF-binding sites remains largely elusive. Here, we show that the ATP-dependent chromatin remodeler, chromodomain helicase DNA-binding 4 (CHD4), regulates chromatin accessibility to conceal aberrant CTCF-binding sites embedded in H3K9me3-enriched heterochromatic B2 short interspersed nuclear elements (SINEs) in mouse embryonic stem cells (mESCs). Upon CHD4 depletion, these aberrant CTCF-binding sites become accessible and aberrant CTCF recruitment occurs within TADs, resulting in disorganization of local TADs. RNA-binding intrinsically disordered domains (IDRs) of CHD4 are required to prevent this aberrant CTCF binding, and CHD4 is critical for the repression of B2 SINE transcripts. These results collectively reveal that a CHD4-mediated mechanism ensures appropriate CTCF binding and associated TAD organization in mESCs.


Assuntos
Fator de Ligação a CCCTC/metabolismo , Cromatina/metabolismo , DNA Helicases/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Animais , Sítios de Ligação , Técnicas de Cultura de Células , Camundongos
13.
Ann Surg Oncol ; 28(13): 8884-8891, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34275048

RESUMO

Despite advances in imaging and biopsy techniques, the management of thyroid nodules often remains a diagnostic and clinical challenge. In particular, patients with cytologically indeterminate nodules often undergo diagnostic thyroidectomy although only a minority of patients are found to have thyroid malignancy on final pathology. More recently, several molecular testing platforms have been developed to improve the stratification of cancer risk for patients with cytologically indeterminate thyroid nodules. Based on numerous studies demonstrating its accuracy, molecular testing has been incorporated as an important diagnostic adjunct in the management of indeterminate thyroid nodules in the National Comprehensive Cancer Network Guidelines as well as in the American Thyroid Association (ATA) and American Association of Endocrine Surgeons (AAES) guidelines. This overview describes the currently available molecular testing platforms and highlights the published data to date on the clinical validity and utility of molecular testing in the contemporary management of thyroid nodules.


Assuntos
Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Humanos , Técnicas de Diagnóstico Molecular , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/cirurgia , Nódulo da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/genética , Nódulo da Glândula Tireoide/cirurgia , Tireoidectomia , Estados Unidos
14.
Genomics Inform ; 19(1): e3, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33840167

RESUMO

Functional interpretation of noncoding genetic variants associated with complex human diseases and traits remains a challenge. In an effort to enhance our understanding of common germline variants associated with lung cancer, we categorize regulatory elements based on eight major cell types of human lung tissue. Our results show that 21.68% of lung cancer‒associated risk variants are linked to noncoding regulatory elements, nearly half of which are cell type‒specific. Integrative analysis of high-resolution long-range chromatin interactome maps and single-cell RNA-sequencing data of lung tumors uncovers number of putative target genes of these variants and functionally relevant cell types, which display a potential biological link to cancer susceptibility. The present study greatly expands the scope of functional annotation of lung cancer‒associated genetic risk factors and dictates probable cell types involved in lung carcinogenesis.

16.
J Gastrointest Surg ; 25(11): 2908-2919, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33634422

RESUMO

BACKGROUND: Prognostication based on preoperative clinical factors is lacking in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). This study aims to determine the value of preoperative tumor markers as predictors of progression-free survival (PFS) and overall survival (OS) for patients with peritoneal carcinomatosis from a primary mucinous adenocarcinoma of the appendix (MACA). METHODS: We queried the United States HIPEC Collaborative, a database of patients with peritoneal carcinomatosis treated with CRS/HIPEC at twelve institutions between 2000 and 2017, identifying 409 patients with MACA. Multivariate analysis was used to identify independent predictors of disease progression. Subgroup analysis was conducted to evaluate the impact of tumor grade on the predictive value of tumor markers. RESULTS: CA19-9 [HR 2.44, CI 1.2-3.4] emerged as an independent predictor of PFS while CEA [HR 4.98, CI 1.06-23.46] was independently predictive of OS (p <0.01). Tumor differentiation was the most potent predictor of both PFS (poorly differentiated vs well, [HR 4.5 CI 2.01-9.94]) and OS ([poorly differentiated vs well-differentiated: [HR 13.5, CI 3.16-57.78]), p <0.05. Among patients with combined CA19-9 elevation and poorly differentiated histology, 86% recurred within a year of CRS/HIPEC (p < 0.01). Similarly, the coexistence of CEA elevation and unfavorable histology led to the lowest survival rate at two years [36%, p < 0.01]. CA-125 was not predictive of PFS or OS. CONCLUSION: Elevated preoperative CA19-9 portends worse PFS, while elevated CEA predicts worse OS after CRS/HIPEC in patients with MACA. This study provides additional evidence that CA19-9 and CEA levels should be collected during standard preoperative bloodwork, while CA-125 can likely be omitted. Tumor differentiation, when added to preoperative tumor marker levels, provides powerful prognostic information. Prospective studies are required to confirm this association.


Assuntos
Adenocarcinoma , Neoplasias do Apêndice , Apêndice , Hipertermia Induzida , Neoplasias Peritoneais , Adenocarcinoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias do Apêndice/terapia , Biomarcadores Tumorais , Terapia Combinada , Procedimentos Cirúrgicos de Citorredução , Humanos , Quimioterapia Intraperitoneal Hipertérmica , Neoplasias Peritoneais/tratamento farmacológico , Estudos Retrospectivos , Taxa de Sobrevida
17.
Surg Oncol ; 36: 138-146, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33418464

RESUMO

BACKGROUND AND OBJECTIVES: Routine lymphadenectomy (LND) for resectable hepatocellular carcinoma (HCC) remains controversial. We evaluated national LND trends to identify pre-operative factors associated with node-positive disease to determine which patients might benefit from LND. METHODS: We identified HCC patients in the National Cancer Database (NCDB) treated with surgical resection between 2004 and 2015. Demographic, operative, pathologic, and survival data were compared. Multivariable regression was performed to determine preoperative predictors of pathologic nodal disease. RESULTS: Of 8095 total resected patients, 1442 (17.8%) underwent hepatectomy with LND. Patients who received LND had higher preoperative clinical T (T3-T4: 20.0% vs 12.1%, p < 0.001) and N (N1: 3.3% vs 0.6%, p < 0.001) stages. The strongest independent predictor of pathologic nodal disease was clinical N stage (OR 106.54, CI 44.10-257.42). Survival was highest in patients whose surgeons omitted LND or were found with LND to be node-negative on final pathology (p < 0.001). Clinical node positivity had high negative predictive value (97.9%) but moderate positive predictive value (56.3%) in estimating pathologic nodal status. CONCLUSIONS: Defining preoperative clinical nodal status is imperative in HCC patients. Clinical node positivity was the strongest predictor of pathologic nodal disease and its associated worse prognosis. LND can be considered selectively in clinically node-positive patients.


Assuntos
Carcinoma Hepatocelular/cirurgia , Hepatectomia/mortalidade , Neoplasias Hepáticas/cirurgia , Excisão de Linfonodo/mortalidade , Linfonodos/patologia , Padrões de Prática Médica/estatística & dados numéricos , Idoso , Carcinoma Hepatocelular/patologia , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
18.
Surg Oncol ; 37: 101492, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33465587

RESUMO

BACKGROUND: While recent studies have introduced the composite measure of a textbook outcome (TO) for measuring postoperative outcomes, the incidence of a TO has not been characterized among patients undergoing cytoreductive surgery (CRS) for peritoneal surface malignancies (PSM). STUDY DESIGN: All patients who underwent CRS ± hyperthermic intraperitoneal chemotherapy (HIPEC) between 1999 and 2017 from 12 institutions were included. A TO was defined as the absence of any of the following criteria: completeness of cytoreduction >1, reoperation within 90-days, readmission within 90-days, mortality within 90-days, any grade ≥2 complication, hospital stay >75th percentile, and non-home discharge. RESULTS: Among 1904 patients who underwent CRS, only 30.9% achieved a TO while 69.1% failed to achieve a TO most commonly because of postoperative complications. On multivariable analysis, factors associated with achieving a TO were age <65 years (OR: 1.5), albumin ≥3.5 g/dl (OR: 5.7), receipt of HIPEC (OR: 4.5), PCI ≤14 (OR: 2.2), intravenous fluid volume ≤10,000 ml (OR: 2.1), blood loss ≤1000 ml (OR: 4.2) and operative time <7 h (OR: 1.9); while receipt of neoadjuvant therapy (OR: 0.7) and liver resection (OR: 0.4) were associated with not achieving a TO (all p < 0.05). TO was associated with improved overall survival (median 159 months vs 56 months, p < 0.01) even after controlling for confounders on Cox regression (hazard ratio: 2.5, p < 0.01). CONCLUSION: Among patients undergoing CRS ± HIPEC for PSM, failure to achieve a TO is common and independently associated with worse overall survival.


Assuntos
Procedimentos Cirúrgicos de Citorredução , Neoplasias Peritoneais/cirurgia , Idoso , Procedimentos Cirúrgicos de Citorredução/efeitos adversos , Procedimentos Cirúrgicos de Citorredução/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Resultado do Tratamento , Estados Unidos/epidemiologia
19.
Nucleic Acids Res ; 49(3): 1426-1435, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33476368

RESUMO

Recombinase A (RecA) is central to homologous recombination. However, despite significant advances, the mechanism with which RecA is able to orchestrate a search for homology remains elusive. DNA nanostructure-augmented high-speed AFM offers the spatial and temporal resolutions required to study the RecA recombination mechanism directly and at the single molecule level. We present the direct in situ observation of RecA-orchestrated alignment of homologous DNA strands to form a stable recombination product within a supporting DNA nanostructure. We show the existence of subtle and short-lived states in the interaction landscape, which suggests that RecA transiently samples micro-homology at the single RecA monomer-level throughout the search for sequence alignment. These transient interactions form the early steps in the search for sequence homology, prior to the formation of stable pairings at >8 nucleotide seeds. The removal of sequence micro-homology results in the loss of the associated transient sampling at that location.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Escherichia coli/metabolismo , Recombinação Homóloga , Recombinases Rec A/metabolismo , DNA/química , Microscopia de Força Atômica , Nanoestruturas/química , Polimerização , Homologia de Sequência do Ácido Nucleico
20.
Front Cell Infect Microbiol ; 11: 764585, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35368453

RESUMO

To date, investigations of the microbiota in the lungs of people with Cystic Fibrosis (PWCF) have primarily focused on microbial community composition in luminal mucus, with fewer studies observing the microbiota in tissue samples from explanted lung tissue. Here, we analysed both tissue and airway luminal mucus samples extracted from whole explanted lungs of PWCF and unused donor lungs. We determined if the lung microbiota in end-stage CF varied within and between patients, was spatially heterogeneous and related to localized structural damage. Microbial community composition was determined by Illumina MiSeq sequencing and related to the CF-Computed Tomography (CT) score and features of end-stage lung disease on micro-CT. Ninety-eight CF tissue (n=11 patients), 20 CF luminal mucus (n=8 patients) and 33 donor tissue (n=4 patients) samples were analysed. Additionally, we compared 20 paired CF tissue and luminal mucus samples that enabled a direct "geographical" comparison of the microbiota in these two niches. Significant differences in microbial communities were apparent between the 3 groups. However, overlap between the three groups, particularly between CF and donor tissue and CF tissue and CF luminal mucus was also observed. Microbial diversity was lower in CF luminal mucus compared to CF tissue, with dominance higher in luminal mucus. For both CF and donor tissue, intra- and inter-patient variability in ecological parameters was observed. No relationships were observed between ecological parameters and CF-CT score, or features of end-stage lung disease. The end-stage CF lung is characterised by a low diversity microbiota, differing within and between individuals. No clear relationship was observed between regional microbiota variation and structural lung damage.


Assuntos
Fibrose Cística , Microbiota , Humanos , Pulmão/diagnóstico por imagem , Muco , Tomografia Computadorizada por Raios X
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