207 research outputs found

    Analysis of Chlamydia pneumoniae and AD-like Pathology in the Brains of BALB/c Mice Following Direct Intra-cranial Infection

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    Alzheimer’s disease (AD) is an age-related progressive neurodegenerative disorder and the most common form of dementia. The pathology in the central nervous system (CNS) impairs memory and cognition, hindering the capabilities and the quality of life of the individual. This project continues studying the role of infection and Alzheimer’s disease, as previous studies in this laboratory have done, and contributes to the overall understanding of the possible causes of this disease. In this study, BALB/c mice were infected, via direct intracranial injection, with a respiratory isolate (AR-39) of Chlamydia pneumoniae. Their brains were analyzed at 7 and 14 days post-infection, via immunohistochemistry, for the presence of C. pneumoniae, amyloid deposits and activated glial cells. The goal of this project was to measure the location and degree of C. pneumoniae burden, amyloid deposition and glial cell activation in the CNS following direct intracranial injection and to compare this data with results obtained from previous studies in this laboratory. We hypothesized that C. pneumoniae antigen and activated inflammatory cells will be observed in the infected mouse brains following direct intracranial injection and Aβ deposition will be observed in areas where inflammation occurs. C. pneumoniae, amyloid deposits and activated glial cells were detected in the brains following direct intracranial infection with C. pneumoniae. In infected mice there was an approximate 3.5-fold increase of C. pneumoniae antigen burden compared to uninfected mice at day 7 and there was an approximate 5.5-fold increase of C. pneumoniae antigen burden compared to uninfected mice at day 14. The burden of C. pneumoniae antigen, in the infected mice, increased 1.009-fold (no change) from day 7 to day 14 post-infection. The amyloid burden in infected mice increased approximately 3-fold compared to uninfected mice at day 7 and increased greater than10-fold compared to uninfected mice at day 14. The burden of amyloid, in the infected mice, increased 7-fold from day 7 to 14. From 7 to 14 days post-infection the C. pneumoniae and amyloid deposits located near the injection site spread distally from this location to other regions of the brain. Global activation of glia was observed in the CNS of infected mice at both 7 and 14 days post-infection. This data confirms that C. pneumoniae is capable of establishing an infection in the CNS. Although deposits were observed, the lack of a substantial amount of amyloid deposits suggested that the generation of deposits may require longer than 14 days following C. pneumoniae infection. As early as 7 days post-infection, inflammation is observed in response to the presence of C. pneumoniae and/or soluble amyloid in the CNS and the contribution of both infection with C. pneumoniae and the presence of soluble amyloid elicit the inflammatory response that presumably precedes and contributes to amyloid depositionhttps://digitalcommons.pcom.edu/posters/1003/thumbnail.jp

    Analysis of SARS-CoV-2 Emergent variants following AZD7442 (tixagevimab/cilgavimab) for early outpatient treatment of COVID-19 (TACKLE trial)

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    Introduction: AZD7442 (tixagevimab/cilgavimab) comprises neutralising monoclonal antibodies (mAbs) that bind to distinct non-overlapping epitopes on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. Viral evolution during mAb therapy can select for variants with reduced neutralisation susceptibility. We examined treatment-emergent SARS-CoV-2 variants during TACKLE (NCT04723394), a phase 3 study of AZD7442 for early outpatient treatment of coronavirus disease 2019 (COVID-19). Methods: Non-hospitalised adults with mild-to-moderate COVID-19 were randomised and dosed ≤ 7 days from symptom onset with AZD7442 (n = 452) or placebo (n = 451). Next-generation sequencing of the spike gene was performed on SARS-CoV-2 reverse-transcription polymerase chain reaction-positive nasopharyngeal swabs at baseline and study days 3, 6, and 15 post dosing. SARS-CoV-2 lineages were assigned using spike nucleotide sequences. Amino acid substitutions were analysed at allele fractions (AF; % of sequence reads represented by substitution) ≥ 25% and 3% to 25%. In vitro susceptibility to tixagevimab, cilgavimab, and AZD7442 was evaluated for all identified treatment-emergent variants using a pseudotyped microneutralisation assay. Results: Longitudinal spike sequences were available for 461 participants (AZD7442, n = 235; placebo, n = 226) and showed that treatment-emergent variants at any time were rare, with 5 (2.1%) AZD7442 participants presenting ≥ 1 substitution in tixagevimab/cilgavimab binding sites at AF ≥ 25%. At AF 3% to 25%, treatment-emergent variants were observed in 15 (6.4%) AZD7442 and 12 (5.3%) placebo participants. All treatment-emergent variants showed in vitro susceptibility to AZD7442. Conclusion: These data indicate that AZD7442 creates a high genetic barrier for resistance and is a feasible option for COVID-19 treatment

    Analysis of SARS-CoV-2 Emergent Variants Following AZD7442 (Tixagevimab/Cilgavimab) for Early Outpatient Treatment of COVID-19 (TACKLE Trial)

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    Introduction: AZD7442 (tixagevimab/cilgavimab) comprises neutralising monoclonal antibodies (mAbs) that bind to distinct non-overlapping epitopes on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. Viral evolution during mAb therapy can select for variants with reduced neutralisation susceptibility. We examined treatment-emergent SARS-CoV-2 variants during TACKLE (NCT04723394), a phase 3 study of AZD7442 for early outpatient treatment of coronavirus disease 2019 (COVID-19). // Methods: Non-hospitalised adults with mild-to-moderate COVID-19 were randomised and dosed ≤ 7 days from symptom onset with AZD7442 (n = 452) or placebo (n = 451). Next-generation sequencing of the spike gene was performed on SARS-CoV-2 reverse-transcription polymerase chain reaction-positive nasopharyngeal swabs at baseline and study days 3, 6, and 15 post dosing. SARS-CoV-2 lineages were assigned using spike nucleotide sequences. Amino acid substitutions were analysed at allele fractions (AF; % of sequence reads represented by substitution) ≥ 25% and 3% to 25%. In vitro susceptibility to tixagevimab, cilgavimab, and AZD7442 was evaluated for all identified treatment-emergent variants using a pseudotyped microneutralisation assay. // Results: Longitudinal spike sequences were available for 461 participants (AZD7442, n = 235; placebo, n = 226) and showed that treatment-emergent variants at any time were rare, with 5 (2.1%) AZD7442 participants presenting ≥ 1 substitution in tixagevimab/cilgavimab binding sites at AF ≥ 25%. At AF 3% to 25%, treatment-emergent variants were observed in 15 (6.4%) AZD7442 and 12 (5.3%) placebo participants. All treatment-emergent variants showed in vitro susceptibility to AZD7442. // Conclusion: These data indicate that AZD7442 creates a high genetic barrier for resistance and is a feasible option for COVID-19 treatment

    A process model of natural attenuation in drainage from a historic mining district

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    A process model was used to better understand the controls on the chemical evolution of drainage in a historic mining district. At the Pecos Mine Operable Unit, New Mexico, drainage near the waste rock pile is acidic (pH varies from 3.0--5.0) and carries high concentrations of Zn, Al, Cu and Pb. As drainage flows toward the Pecos River, pH increases to greater than 7 and heavy metal content decreases. A process model of natural attenuation in this drainage shows the main controls on pH are reaction with a local bedrock that contains limestone, and concurrent mixing with tributary streams. Models that account for both calcite dissolution and mixing reproduce the observed decrease in aqueous metal concentrations with increasing pH. Contaminant concentrations attenuate primarily via two distinct pathways: Al, Cu, Fe and Pb precipitate directly from solution, whereas Zn, Mg, Mn and SO{sub 4} concentrations decrease primarily through dilution. Additionally, Pb adsorbs to precipitating hydroxide surfaces

    Plasma microRNA expression in adolescents and young adults with endometriosis: the importance of hormone use

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    IntroductionPrior studies have investigated the diagnostic potential of microRNA (miRNA) expression profiles for endometriosis. However, the vast majority of previous studies have only included adult women. Therefore, we sought to investigate differential expression of miRNAs among adolescents and young adults with endometriosis.MethodsThe Women's Health Study: from Adolescence to Adulthood (A2A) is an ongoing WERF EPHect compliant longitudinal cohort. Our analysis included 64 patients with surgically-confirmed endometriosis (96% rASRM stage I/II) and 118 females never diagnosed with endometriosis frequency matched on age (median = 21 years) and hormone use at blood draw. MicroRNA measurement was separated into discovery (10 cases and 10 controls) and internal replication (54 cases and 108 controls) phases. The levels of 754 plasma miRNAs were assayed in the discovery phase using PCR with rigorous internal control measures, with the relative expression of miRNA among cases vs. controls calculated using the 2−ΔΔCt method. miRNAs that were significant in univariate analyses stratified by hormone use were included in the internal replication phase. The internal replication phase was split 2:1 into a training and testing set and utilized FirePlex miRNA assay to assess 63 miRNAs in neural network analyses. The testing set of the validation phase was utilized to calculate the area under the curve (AUC) of the best fit models from the training set including hormone use as a covariate.ResultsIn the discovery phase, 49 miRNAs were differentially expressed between endometriosis cases and controls. The associations of the 49 miRNAs differed by hormone use at the time of blood draw. Neural network analysis in the testing set of the internal replication phase determined a final model comprising 5 miRNAs (miR-542-3p, let-7b-3p, miR-548i, miR-769-5p, miR-30c-1-3p), yielding AUC = 0.77 (95% CI: 0.67–0.87, p < 0.001). Sensitivity in the testing dataset improved (83.3% vs. 72.2%) while the specificity decreased (58.3% vs. 72.2%) compared to the training set.ConclusionThe results suggest that miR-542-3p, let-7b-3p, miR-548i, miR-769-5p, miR-30c-1-3p may be dysregulated among adolescent and young adults with endometriosis. Hormone use was a significant modifier of miRNA dysregulation and should be considered rigorously in miRNA diagnostic studies

    p68/DdX5 supports β-Catenin & RNAP II during androgen receptor mediated transcription in prostate cancer

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    The DEAD box RNA helicase p68 (Ddx5) is an important androgen receptor (AR) transcriptional co-activator in prostate cancer (PCa) and is over-expressed in late stage disease. β-Catenin is a multifunctional protein with important structural and signalling functions which is up-regulated in PCa and similar to p68, interacts with the AR to co-activate expression of AR target genes. Importantly, p68 forms complexes with nuclear β-Catenin and promotes gene transcription in colon cancer indicating a functional interplay between these two proteins in cancer progression. In this study, we explore the relationship of p68 and β-Catenin in PCa to assess their potential co-operation in AR-dependent gene expression, which may be of importance in the development of castrate resistant prostate cancer (CRPCa). We use immunoprecipitation to demonstrate a novel interaction between p68 and β-Catenin in the nucleus of PCa cells, which is androgen dependent in LNCaP cells but androgen independent in a hormone refractory derivative of the same cell line (representative of the CRPCa disease type). Enhanced AR activity is seen in androgen-dependent luciferase reporter assays upon transient co-transfection of p68 and β-Catenin as an additive effect, and p68-depleted Chromatin-Immunoprecipitation (ChIP) showed a decrease in the recruitment of the AR and β-Catenin to androgen responsive promoter regions. In addition, we found p68 immunoprecipitated with the processive and non-processive form of RNA polymerase II (RNAP II) and show p68 recruited to elongating regions of the AR mediated PSA gene, suggesting a role for p68 in facilitating RNAP II transcription of AR mediated genes. These results suggest p68 is important in facilitating β-Catenin and AR transcriptional activity in PCa cells

    Integrated RNA and DNA sequencing reveals early drivers of metastatic breast cancer

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    Breast cancer metastasis remains a clinical challenge, even within a single patient across multiple sites of the disease. Genome-wide comparisons of both the DNA and gene expression of primary tumors and metastases in multiple patients could help elucidate the underlying mechanisms that cause breast cancer metastasis. To address this issue, we performed DNA exome and RNA sequencing of matched primary tumors and multiple metastases from 16 patients, totaling 83 distinct specimens. We identified tumor-specific drivers by integrating known protein-protein network information with RNA expression and somatic DNA alterations and found that genetic drivers were predominantly established in the primary tumor and maintained through metastatic spreading. In addition, our analyses revealed that most genetic drivers were DNA copy number changes, the TP53 mutation was a recurrent founding mutation regardless of subtype, and that multiclonal seeding of metastases was frequent and occurred in multiple subtypes. Genetic drivers unique to metastasis were identified as somatic mutations in the estrogen and androgen receptor genes. These results highlight the complexity of metastatic spreading, be it monoclonal or multiclonal, and suggest that most metastatic drivers are established in the primary tumor, despite the substantial heterogeneity seen in the metastases

    Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

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    Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
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