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Found 37684 matches. Displaying 2251-2260
Chauve L, Le Pen J, Hodge F, Todtenhaupt P, Biggins L, Miska EA, Andrews S, Casanueva O
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High-Throughput Quantitative RT-PCR in Single and Bulk C. elegans Samples Using Nanofluidic Technology

JOVE-JOURNAL OF VISUALIZED EXPERIMENTS 2020 MAY; ?(159):? Article e61132
This paper presents a high-throughput reverse transcription quantitative PCR (RT-qPCR) assay for Caenorhabditis elegans that is fast, robust, and highly sensitive. This protocol obtains precise measurements of gene expression from single worms or from bulk samples. The protocol presented here provides a novel adaptation of existing methods for complementary DNA (cDNA) preparation coupled to a nanofluidic RT-qPCR platform. The first part of this protocol, named 'Worm-to-CT', allows cDNA production directly from nematodes without the need for prior mRNA isolation. It increases experimental throughput by allowing the preparation of cDNA from 96 worms in 3.5 h. The second part of the protocol uses existing nanofluidic technology to run high-throughput RT-qPCR on the cDNA. This paper evaluates two different nanofluidic chips: the first runs 96 samples and 96 targets, resulting in 9,216 reactions in approximately 1.5 days of benchwork. The second chip type consists of six 12 x 12 arrays, resulting in 864 reactions. Here, the Worm-to-CT method is demonstrated by quantifying mRNA levels of genes encoding heat shock proteins from single worms and from bulk samples. Provided is an extensive list of primers designed to amplify processed RNA for the majority of coding genes within the C. elegans genome.
Wu XJ, Spence JS, Das T, Yuan XQ, Chen CJ, Zhang YQ, Li YM, Sun YN, Chandran K, Hang HC, Peng T
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Site-Specific Photo-Crosslinking Proteomics Reveal Regulation of IFITM3 Trafficking and Turnover by VCP/p97 ATPase

CELL CHEMICAL BIOLOGY 2020 MAY 21; 27(5):571-585.e6
Interferon-induced transmembrane protein 3 (IFITM3) is a key interferon effector that broadly prevents infection by diverse viruses. However, the cellular factors that control IFITM3 homeostasis and antiviral activity have not been fully elucidated. Using site-specific photo-crosslinking and quantitative proteomic analysis, here we present the identification and functional characterization of VCP/p97 AAA-ATPase as a primary interaction partner of IFITM3. We show that IFITM3 ubiquitination at lysine 24 is crucial for VCP binding, trafficking, turnover, and engagement with incoming virus particles. Consistently, pharmacological inhibition of VCP/p97 ATPase activity leads to defective IFITM3 lysosomal sorting, turnover, and co-trafficking with virus particles. Our results showcase the utility of site-specific protein photo-crosslinking in mammalian cells and reveal VCP/p97 as a key cellular factor involved in IFITM3 trafficking and homeostasis.
Huang TT, Matsuyama HJ, Tsukada Y, Singhvi A, Syu RT, Lu Y, Shaham S, Mori I, Pan CL
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Age-dependent changes in response property and morphology of a thermosensory neuron and thermotaxis behavior in Caenorhabditis elegans

AGING CELL 2020 MAY; 19(5):? Article e13146
Age-dependent cognitive and behavioral deterioration may arise from defects in different components of the nervous system, including those of neurons, synapses, glial cells, or a combination of them. We find that AFD, the primary thermosensory neuron of Caenorhabditis elegans, in aged animals is characterized by loss of sensory ending integrity, including reduced actin-based microvilli abundance and aggregation of thermosensory guanylyl cyclases. At the functional level, AFD neurons in aged animals are hypersensitive to high temperatures and show sustained sensory-evoked calcium dynamics, resulting in a prolonged operating range. At the behavioral level, senescent animals display cryophilic behaviors that remain plastic to acute temperature changes. Excessive cyclase activity of the AFD-specific guanylyl cyclase, GCY-8, is associated with developmental defects in AFD sensory ending and cryophilic behavior. Surprisingly, loss of the GCY-8 cyclase domain reduces these age-dependent morphological and behavioral changes, while a prolonged AFD operating range still exists in gcy-8 animals. The lack of apparent correlation between age-dependent changes in the morphology or stimuli-evoked response properties of primary sensory neurons and those in related behaviors highlights the importance of quantitative analyses of aging features when interpreting age-related changes at structural and functional levels. Our work identifies aging hallmarks in AFD receptive ending, temperature-evoked AFD responses, and experience-based thermotaxis behavior, which serve as a foundation to further elucidate the neural basis of cognitive aging.
Frew JW, Grand D, Navrazhina K, Krueger JG
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Beyond antibodies: B cells in Hidradenitis Suppurativa: Bystanders, contributors or therapeutic targets?

EXPERIMENTAL DERMATOLOGY 2020 MAY; 29(5):509-515
Hidradenitis Suppurativa (HS) is a chronic inflammatory dermatosis in which B cells play a prominent but unclear role. Our understanding of the role of B cells in innate and adaptive immunity (including antibody production, antigen presentation and effector functions) is rapidly evolving; and these novel findings require integration into the pathophysiologic model of HS. B cells are transiently present in normal human skin and have functions in the maintenance of innate cutaneous immunity. Recruitment and trafficking of B cells in significant numbers to skin is mediated via B cell-specific chemokines as well as shared signalling with T-cells. The evidence suggests that the presence of antibody-secreting B cells is not sufficient to induce clinical disease and T-cell interaction is required to induce clinical disease. Such interactions can occur in secondary lymphoid organs adjacent to involved tissue or in tertiary lymphoid organs which develop in response to the HS inflammatory milieu. This milieu directly mediates the types of antibodies produced by B cells, given the role of cytokines in B-cell class switching. Identified antibodies in HS (IgG, IgM, ASCA, ACPA) currently demonstrate no evidence of pathogenicity, but may be novel biomarkers for disease severity. B cells also have anti-inflammatory properties through production of IL-10 and IL-35 which require experimental validation. Overall, B cells in HS are likely to be involved in amplification of a pre-existing inflammatory response; but it remains unclear whether they may be directly pathogenic.
Stanley S, Vanarsa K, Soliman S, Habazi D, Pedroza C, Gidley G, Zhang T, Mohan S, Der E, Suryawanshi H, Tuschl T, Buyon J, Putterman C, Mok CC, Petri M, Saxena R, Mohan C
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Comprehensive aptamer-based screening identifies a spectrum of urinary biomarkers of lupus nephritis across ethnicities

NATURE COMMUNICATIONS 2020 MAY 4; 11(1):2197
Emerging urinary biomarkers continue to show promise in evaluating lupus nephritis (LN). Here, we screen urine from active LN patients for 1129 proteins using an aptamer-based platform, followed by ELISA validation in two independent cohorts comprised of 127 inactive lupus, 107 active LN, 67 active non-renal lupus patients and 74 healthy controls, of three different ethnicities. Urine proteins that best distinguish active LN from inactive disease are ALCAM, PF-4, properdin, and VCAM-1 among African-Americans, sE-selectin, VCAM-1, BFL-1 and Hemopexin among Caucasians, and ALCAM, VCAM-1, TFPI and PF-4 among Asians. Most of these correlate significantly with disease activity indices in the respective ethnic groups, and surpass conventional metrics in identifying active LN, with better sensitivity, and negative/positive predictive values. Several elevated urinary molecules are also expressed within the kidneys in LN, based on single-cell RNAseq analysis. Longitudinal studies are warranted to assess the utility of these biomarkers in tracking lupus nephritis. Developing noninvasive diagnostic biomarkers for lupus nephritis (LN) diagnosis is an important clinical goal. Here the authors identify urinary proteins correlated with active LN and disease severity, which differ across ethnicities but collectively outperform the current clinical method.
Beguelin W, Teater M, Meydan C, Hoehn KB, Phillip JM, Soshnev AA, Venturutti L, Rivas MA, Calvo-Fernandez MT, Gutierrez J, Camarillo JM, Takata K, Tarte K, Kelleher NL, Steidl C, Mason CE, Elemento O, Allis CD, Kleinstein SH, Melnick AM
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Mutant EZH2 Induces a Pre-malignant Lymphoma Niche by Reprogramming the Immune Response

CANCER CELL 2020 MAY 11; 37(5):655-673.e11
Follicular lymphomas (FLs) are slow-growing, indolent tumors containing extensive follicular dendritic cell (FDC) networks and recurrent EZH2 gain-of-function mutations. Paradoxically, FLs originate from highly proliferative germinal center (GC) B cells with proliferation strictly dependent on interactions with T follicular helper cells. Herein, we show that EZH2 mutations initiate FL by attenuating GC B cell requirement for T cell help and driving slow expansion of GC centrocytes that become enmeshed with and dependent on FDCs. By impairing T cell help, mutant EZH2 prevents induction of proliferative MYC programs. Thus, EZH2 mutation fosters malignant transformation by epigenetically reprograming B cells to form an aberrant immunological niche that reflects characteristic features of human FLs, explaining how indolent tumors arise from GC B cells.
Gerber A, Ito K, Chu CS, Roeder RG
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Gene-Specific Control of tRNA Expression by RNA Polymerase II

MOLECULAR CELL 2020 MAY 21; 78(4):765-778.e7
Increasing evidence suggests that tRNA levels are dynamically and specifically regulated in response to internal and external cues to modulate the cellular translational program. However, the molecular players and the mechanisms regulating the gene-specific expression of tRNAs are still unknown. Using an inducible auxin-degron system to rapidly deplete RPB1 (the largest subunit of RNA Pol II) in living cells, we identified Pol II as a direct gene-specific regulator of tRNA transcription. Our data suggest that Pol II transcription robustly interferes with Pol III function at specific tRNA genes. This activity was further found to be essential for MAF1-mediated repression of a large set of tRNA genes during serum starvation, indicating that repression of tRNA genes by Pol II is dynamically regulated. Hence, Pol II plays a direct and central role in the gene-specific regulation of tRNA expression.
Iyengar MF, Soto LF, Requena D, Ruiz-Alejos AO, Huaylinos Y, Velasquez R, Bernabe-Ortiz A, Gilman RH
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Tear biomarkers and corneal sensitivity as an indicator of neuropathy in type 2 diabetes

DIABETES RESEARCH AND CLINICAL PRACTICE 2020 MAY; 163(?):? Article 108143
Aims: Explore potential of 31 tear biomarkers involved in screening for diabetic peripheral neuropathy (DPN). Assess the utility of aesthesiometry for measuring corneal damage in DPN and determine optimal cutoff point for detecting DPN. Methods: Screening test pilot study recruited 90 participants from a tertiary hospital in Lima, Peru. Participants were grouped by diabetes and neuropathy status. Tears collected on Schirmer strips, and proteins measured by both ELISA and multiplex-bead assay. Corneal sensitivity was measured by aesthesiometry, and DPN by vibration perception threshold testing. Results: There were 89 participants included in the analysis. The mean age was 55.7 +/- 1.46, and 58.4% were female. MMP-9 and TGF-alpha concentrations were higher in participants with DPN versus diabetes alone, though not significant. Aesthesiometry was decreased in individuals with DPN when compared to participants with diabetes alone (p < 0.01) and normal controls (p < 0.01). Optimal cutoff point for aesthesiometry was found to be 5.8 cm, with 79% sensitivity and 75% specificity. Conclusions: Tears are an insufficient standalone tool for detecting DPN based on the biomarkers analyzed. Aesthesiometry is a simple, inexpensive, and accurate method to assess corneal damage associated with moderate-severe DPN, and its integration into screening practices has potential to improve detection of DPN in poor-resource settings. (C) 2020 Elsevier B.V. All rights reserved.
Gleicher N, Albertini DF, Barad DH, Homer H, Modi D, Murtinger M, Patrizio P, Orvieto R, Takahashi S, Weghofer A, Ziebe S, Noyes N
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The 2019PGDISposition statement on transfer of mosaic embryos within a context of new information on PGT-A

REPRODUCTIVE BIOLOGY AND ENDOCRINOLOGY 2020 MAY 29; 18(1):? Article 57
Background A recently published Position Statement (PS) by thePreimplantation Genetics Diagnosis International Society (PGDIS)regarding utilization of preimplantation genetic testing for aneuploidy (PGT-A) in association with in vitro fertilization (IVF) contained inaccuracies and misrepresentations. Because opinions issued by thePGDIShave since 2016 determined worldwide IVF practice, corrections appear of importance. Methods TheInternational Do No Harm Group in IVF (IDNHG-IVF)is a spontaneously coalesced body of international investigators, concerned with increasing utilization of add-ons to IVF. It is responsible for the presented consensus statement, which as a final document was reached after review of the pertinent literature and again revised after the recent publication of the STAR trial and related commentaries. Results In contrast to the PGDIA-PS, we recommend restrictions to the increasing, and by IVF centers now often even mandated, utilization of PGT-A in IVF cycles. While PGT-A has been proposed as a tool for achieving enhanced singleton livebirth outcomes through embryo selection, continued false-positive rates and increasing evidence for embryonic self-correction downstream from the testing stage, has ledIDNHG-IVFto conclude that currently available data are insufficient to impose overreaching recommendations for PGT-A utilization. Discussion Here presented consensus offers an alternative to the 2019PGDISposition statement regarding utilization of preimplantation genetic testing for aneuploidy (PGT-A) in association with in vitro fertilization (IVF). Mindful of what appears to offer best outcomes for patients, and in full consideration of patient autonomy, here presented opinion is based on best available evidence, with the goal of improving safety and efficacy of IVF and minimizing wastage of embryos with potential for healthy births. Conclusions As thePGDISnever suggested restrictions on clinical utilization of PGT-A in IVF, here presented rebuttal represents an act of self-regulation by parts of the IVF community in attempts to control increasing utilization of different unproven recent add-ons to IVF.
Frew JW, Jiang CS, Singh N, Grand D, Navrazhina K, Vaughan R, Krueger JG
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Clinical response rates, placebo response rates, and significantly associated covariates are dependent on choice of outcome measure in hidradenitis suppurativa: A post hoc analysis of PIONEER 1 and 2 individual patient data

JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY 2020 MAY; 82(5):1150-1157
Background: The hidradenitis suppurativa clinical response (HiSCR) is the gold standard primary outcome measure for hidradenitis suppurativa clinical trials; however, it does not assess the presence of draining tunnels, a common finding in advanced disease. It is unclear what the effect of the presence or absence of draining tunnels has on the efficacy of adalimumab therapy in moderate and advanced disease. Objectives: We evaluated the efficacy of adalimumab versus placebo using the International Hidradenitis Suppurativa Severity Scoring System (IHS4). Additionally, we assessed the effect of draining tunnels on therapeutic response as measured by both the HiSCR and change in nodule counts. Methods: Reanalysis was conducted with the IHS4 and PIONEER 1 and 2 individual patient data. Both binary outcomes (achieving HiSCR and achieving change in IHS4 severity category) and continuous outcomes (nodule counts and IHS4 score) were calculated with R. Regression modeling was undertaken to assess the effect of draining tunnels and other variables. P<.05 was considered statistically significant. Results: The significance of adalimumab therapy depended on the outcome measure used. Placebo response rates were highest when binary outcome measures were used. Draining tunnels, smoking, antibiotics, and body mass index influenced HiSCR response in PIONEER 2. Significant differences in disease severity were observed between PIONEER 1 and 2 data sets. Conclusions: Elevated placebo response rates in PIONEER 1 and 2 are partially attributable to the use of binary outcome measures. Draining tunnels influence clinical response as measured by HiSCR and nodule counts in PIONEER 2. Further investigation into the effect of body mass index on clinical response is required.