359 research outputs found
Expression of citrulline and homocitrulline residues in the lungs of non-smokers and smokers : implications for autoimmunity in rheumatoid arthritis
Introduction: Smoking is a well-established risk factor for rheumatoid arthritis (RA), and it has been proposed that smoking-induced citrullination renders autoantigens immunogenic. To investigate this mechanism, we examined human lung tissue from 40 subjects with defined smoking status, with or without chronic obstructive pulmonary disease (COPD), and control tissues from other organs for citrullinated proteins and the deiminating enzymes peptidylarginine deiminase type-2 (PAD2) and -4 (PAD4).
Methods: Lung tissue samples, dissected from lobectomy specimens from 10 never smokers, 10 smokers without airflow limitation, 13 COPD smokers and eight COPD ex-smokers, and control tissue samples (spleen, skeletal muscle, liver, ovary, lymph node, kidney and heart), were analysed for citrullinated proteins, PAD2 and PAD4 by immunoblotting. Citrulline and homocitrulline residues in enolase and vimentin were analysed by partial purification by gel electrophoresis followed by mass spectrometry in 12 of the lung samples and one from each control tissues. Band intensities were scored semi-quantitatively and analysed by two-tailed Mann-Whitney T-test.
Results: Within the lung tissue samples, citrullinated proteins, PAD2 and PAD4 were found in all samples, with an increase in citrullination in COPD (P = 0.039), but minimal difference between smokers and non-smokers (P = 0.77). Citrullination was also detected at lower levels in the tissues from other organs, principally in lymph node, kidney and skeletal muscle. Mass spectrometry of the lung samples showed that vimentin was citrullinated at positions 71, 304, 346, 410 and 450 in non-smokers and smokers both with and without COPD. A homocitrulline at position 104 was found in four out of six COPD samples and one out of six non-COPD. Citrulline-450 was also found in three of the control tissues. There were no citrulline or homocitrulline residues demonstrated in a-enolase.
Conclusions: We have shown evidence of citrullination of vimentin, a major autoantigen in RA, in both non-smokers and smokers. The increase in citrullinated proteins in COPD suggests that citrullination in the lungs of smokers is mainly due to inflammation. The ubiquity of citrullination of vimentin in the lungs and other tissues suggests that the relationship between smoking and autoimmunity in RA may be more complex than previously thought
Feasibility and Comparative Effectiveness for the Delivery of the National Diabetes Prevention Program through Cooperative Extension in Rural Communities
The U.S. Cooperative Extension Service (CE) has potential to deliver the National Diabetes Prevention Program (NDPP) to rural residents with prediabetes. However, the CE remains underutilized for the delivery of NDPP. We compared the feasibility/effectiveness of the NDPP (0–6 mos.) delivered by CE personnel to rural residents with prediabetes using Zoom® (CE-Zoom®) or by our research staff using Facebook® (FB). Adults (n = 31, age ~55 years) were enrolled (CE-Zoom® n = 16, FB n = 15). Attendance did not differ significantly between groups (CE Zoom® = 69%, FB = 83%, p = 0.15). Participant retention was similar in the CE Zoom® (88%) and FB groups (87%). CE-Zoom® and FB® groups provided weekly, self-monitoring data for 83% and 84% of the 24 potential weeks, respectively. Six-month weight loss was not different between groups (CE-Zoom® = −5.99 ± 8.0 kg, −5.4%, FB = −1.68 ± 3.3 kg, −1.6% p = 0.13). Participants achieving ≥5% weight loss was greater in the CE-Zoom® (44%) compared with the FB group (7%, p = 0.04). Participants achieving the NDPP program goal for physical activity (≥150 min/week) did not differ (CE-Zoom® = 75%, FB = 67%, p = 0.91). This pilot trial demonstrated the potential feasibility and effectiveness of the NDPP delivered by CE personnel in a group remote format (Zoom®) to adults with prediabetes living in rural areas
Identifying Elements of \u3cem\u3eKinder- und Jugendliteratur\u3c/em\u3e
Kinder- und Jugendliteratur, children’s literature written for the purpose of teaching or entertaining young people, has been present in German literature since the Middle Ages. This genre has changed as German literature progressed, reflecting the developments of each era, including such periods as the Romantic, the Biedermeier, Realism, Modernism and Postmodernism. As such, we examined individual works of German Kinder- und Jugendliteratur for the purpose of identifying distinctive features which situate them within children’s literature as well as in the respective historical genre. The works examined were Nußknacker und Mausekönig (1816) by E. T. A. Hoffmann, Emil und die Detektive (1929) by Erich Kästner, Försters Pucki (1935) by Madge Trott, Jan und das Wildpferd (1957) by Heinrich Denneborg, Die Wolke (1987) by Gudrun Pausewang, and Tintenherz (2003) by Cornelia Funke. We present our findings in the form of a Wimmelbuch, a typical form of German Kinder- und Jugendliteratur made popular during the Biedermeier period of the mid-1800s
The surprisingly facile formation of Pd(I)-phosphido complexes from ortho-biphenylphosphines and palladium acetate
Systematic review and network meta-analysis with individual participant data on cord management at preterm birth (iCOMP): study protocol
Introduction
Timing of cord clamping and other cord management strategies may improve outcomes at preterm birth. However, it is unclear whether benefits apply to all preterm subgroups. Previous and current trials compare various policies, including time-based or physiology-based deferred cord clamping, and cord milking. Individual participant data (IPD) enable exploration of different strategies within subgroups. Network meta-analysis (NMA) enables comparison and ranking of all available interventions using a combination of direct and indirect comparisons.
Objectives
(1) To evaluate the effectiveness of cord management strategies for preterm infants on neonatal mortality and morbidity overall and for different participant characteristics using IPD meta-analysis. (2) To evaluate and rank the effect of different cord management strategies for preterm births on mortality and other key outcomes using NMA.
Methods and analysis
Systematic searches of Medline, Embase, clinical trial registries, and other sources for all ongoing and completed randomised controlled trials comparing cord management strategies at preterm birth (before 37 weeks’ gestation) have been completed up to 13 February 2019, but will be updated regularly to include additional trials. IPD will be sought for all trials; aggregate summary data will be included where IPD are unavailable. First, deferred clamping and cord milking will be compared with immediate clamping in pairwise IPD meta-analyses. The primary outcome will be death prior to hospital discharge. Effect differences will be explored for prespecified participant subgroups. Second, all identified cord management strategies will be compared and ranked in an IPD NMA for the primary outcome and the key secondary outcomes. Treatment effect differences by participant characteristics will be identified. Inconsistency and heterogeneity will be explored.
Ethics and dissemination
Ethics approval for this project has been granted by the University of Sydney Human Research Ethics Committee (2018/886). Results will be relevant to clinicians, guideline developers and policy-makers, and will be disseminated via publications, presentations and media releases
Association of distinct fine specificities of anti-citrullinated peptide antibodies with elevated immune responses to Prevotella intermedia in a subgroup of patients with rheumatoid arthritis and periodontitis
Objective
In addition to the long-established link with smoking, periodontitis (PD) is also a risk factor for rheumatoid arthritis (RA). To elucidate the mechanism by which PD could induce antibodies to citrullinated peptides (ACPA), we examine the antibody response to a novel citrullinated peptide from cytokeratin type I 13 identified in gingival crevicular fluid (GCF), and compare the response to 4 other citrullinated peptides in patients with RA, well-characterized for PD and smoking.
Methods
The citrullinomes of GCF and periodontal tissue from people with PD were mapped by mass spectrometry. Antibodies to citrullinated peptides from cytokeratin type I 13 (cCK13), tenascin-C (cTNC5), vimentin (cVIM), enolase (CEP-1) and fibrinogen β (cFIBβ) were examined by ELISA in patients with RA (n=287) and osteoarthritis (OA) (n=330), and cross-reactivity assessed by inhibition assays.
Results
A novel citrullinated peptide cCK13-1 (444TSNASGR-cit-TSDV-cit-RP458) identified in GCF, exhibited elevated antibody responses in RA patients (24%). Anti-cCK13-1 antibodies correlated with anti-cTNC5 antibodies, and absorption experiments confirmed this was not due to cross-reactivity. Only anti-cCK13-1 and anti-cTNC5 were associated with antibodies to the periodontal pathogen Prevotella intermedia (p=0.05 and p =0.001 respectively), but not with antibodies to Porphyromonas gingivalis arginine gingipains. Antibodies to CEP-1, cFIBβ and cVIM correlated with each other, and with smoking and shared epitope risk factors in RA.
Conclusion
This study identifies two groups of ACPA fine specificities associated with different RA risk factors; one predominantly linked to smoking and shared epitope, the other linking anti- cTNC5 and cCK13-1 to infection with the periodontal pathogen P. intermedia
Pathologic gene network rewiring implicates PPP1R3A as a central regulator in pressure overload heart failure
Heart failure is a leading cause of mortality, yet our understanding of the genetic interactions underlying this disease remains incomplete. Here, we harvest 1352 healthy and failing human hearts directly from transplant center operating rooms, and obtain genome-wide genotyping and gene expression measurements for a subset of 313. We build failing and non-failing cardiac regulatory gene networks, revealing important regulators and cardiac expression quantitative trait loci (eQTLs). PPP1R3A emerges as a regulator whose network connectivity changes significantly between health and disease. RNA sequencing after PPP1R3A knockdown validates network-based predictions, and highlights metabolic pathway regulation associated with increased cardiomyocyte size and perturbed respiratory metabolism. Mice lacking PPP1R3A are protected against pressure-overload heart failure. We present a global gene interaction map of the human heart failure transition, identify previously unreported cardiac eQTLs, and demonstrate the discovery potential of disease-specific networks through the description of PPP1R3A as a central regulator in heart failure
Single-cell longitudinal analysis of SARS-CoV-2 infection in human airway epithelium identifies target cells, alterations in gene expression, and cell state changes.
There are currently limited Food and Drug Administration (FDA)-approved drugs and vaccines for the treatment or prevention of Coronavirus Disease 2019 (COVID-19). Enhanced understanding of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and pathogenesis is critical for the development of therapeutics. To provide insight into viral replication, cell tropism, and host-viral interactions of SARS-CoV-2, we performed single-cell (sc) RNA sequencing (RNA-seq) of experimentally infected human bronchial epithelial cells (HBECs) in air-liquid interface (ALI) cultures over a time course. This revealed novel polyadenylated viral transcripts and highlighted ciliated cells as a major target at the onset of infection, which we confirmed by electron and immunofluorescence microscopy. Over the course of infection, the cell tropism of SARS-CoV-2 expands to other epithelial cell types including basal and club cells. Infection induces cell-intrinsic expression of type I and type III interferons (IFNs) and interleukin (IL)-6 but not IL-1. This results in expression of interferon-stimulated genes (ISGs) in both infected and bystander cells. This provides a detailed characterization of genes, cell types, and cell state changes associated with SARS-CoV-2 infection in the human airway
Tissue-resident, extravascular Ly6c- monocytes are critical for inflammation in the synovium
Monocytes are abundant immune cells that infiltrate inflamed organs. However, the majority of monocyte studies focus on circulating cells, rather than those in tissue. Here, we identify and characterize an intravascular synovial monocyte population resembling circulating non-classical monocytes and an extravascular tissue-resident monocyte-lineage cell (TR-MC) population distinct in surface marker and transcriptional profile from circulating monocytes, dendritic cells, and tissue macrophages that are conserved in rheumatoid arthritis (RA) patients. TR-MCs are independent of NR4A1 and CCR2, long lived, and embryonically derived. TR-MCs undergo increased proliferation and reverse diapedesis dependent on LFA1 in response to arthrogenic stimuli and are required for the development of RA-like disease. Moreover, pathways that are activated in TR-MCs at the peak of arthritis overlap with those that are downregulated in LFA1-/- TR-MCs. These findings show a facet of mononuclear cell biology that could be imperative to understanding tissue-resident myeloid cell function in RA.</p
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