dCas9-based epigenome editing suggests acquisition of histone methylation is not sufficient for target gene repression.

Distinct epigenomic profiles of histone marks have been associated with gene expression, but questions regarding the causal relationship remain. Here we investigated the activity of a broad collection of genomically targeted epigenetic regulators that could write epigenetic marks associated with a repressed chromatin state (G9A, SUV39H1, Krüppel-associated box (KRAB), DNMT3A as well as the first targetable versions of Ezh2 and Friend of GATA-1 (FOG1)). dCas9 fusions produced target gene repression over a range of 0- to 10-fold that varied by locus and cell type. dCpf1 fusions were unable to repress gene expression. The most persistent gene repression required the action of several effector domains; however, KRAB-dCas9 did not contribute to persistence in contrast to previous reports. A 'direct tethering' strategy attaching the Ezh2 methyltransferase enzyme to dCas9, as well as a 'recruitment' strategy attaching the N-terminal 45 residues of FOG1 to dCas9 to recruit the endogenous nucleosome remodeling and deacetylase complex, were both successful in targeted deposition of H3K27me3. Surprisingly, however, repression was not correlated with deposition of either H3K9me3 or H3K27me3. Our results suggest that so-called repressive histone modifications are not sufficient for gene repression. The easily programmable dCas9 toolkit allowed precise control of epigenetic information and dissection of the relationship between the epigenome and gene regulation

Cost-efficient nanoscopy reveals nanoscale architecture of liver cells and platelets

Single-molecule localization microscopy (SMLM) provides a powerful toolkit to specifically resolve intracellular structures on the nanometer scale, even approaching resolution classically reserved for electron microscopy (EM). Although instruments for SMLM are technically simple to implement, researchers tend to stick to commercial microscopes for SMLM implementations. Here we report the construction and use of a “custom-built” multi-color channel SMLM system to study liver sinusoidal endothelial cells (LSECs) and platelets, which costs significantly less than a commercial system. This microscope allows the introduction of highly affordable and low-maintenance SMLM hardware and methods to laboratories that, for example, lack access to core facilities housing high-end commercial microscopes for SMLM and EM. Using our custom-built microscope and freely available software from image acquisition to analysis, we image LSECs and platelets with lateral resolution down to about 50 nm. Furthermore, we use this microscope to examine the effect of drugs and toxins on cellular morphology

CCR5AS lncRNA variation differentially regulates CCR5, influencing HIV disease outcome.

Multiple genome-wide studies have identified associations between outcome of human immunodeficiency virus (HIV) infection and polymorphisms in and around the gene encoding the HIV co-receptor CCR5, but the functional basis for the strongest of these associations, rs1015164A/G, is unknown. We found that rs1015164 marks variation in an activating transcription factor 1 binding site that controls expression of the antisense long noncoding RNA (lncRNA) CCR5AS. Knockdown or enhancement of CCR5AS expression resulted in a corresponding change in CCR5 expression on CD4+ T cells. CCR5AS interfered with interactions between the RNA-binding protein Raly and the CCR5 3' untranslated region, protecting CCR5 messenger RNA from Raly-mediated degradation. Reduction in CCR5 expression through inhibition of CCR5AS diminished infection of CD4+ T cells with CCR5-tropic HIV in vitro. These data represent a rare determination of the functional importance of a genome-wide disease association where expression of a lncRNA affects HIV infection and disease progression

Assay strategies for the discovery and validation of therapeutics targeting <i>Brugia pahangi</i> Hsp90

The chemotherapy of lymphatic filariasis relies upon drugs such as diethylcarbamazine and ivermectin that largely target the microfilarial stages of the parasite, necessitating continued treatment over the long reproductive life span of the adult worm. The identification of compounds that target adult worms has been a long-term goal of WHO. Here we describe a fluorescence polarization assay for the identification of compounds that target Hsp90 in adult filarial worms. The assay was originally developed to identify inhibitors of Hsp90 in tumor cells, and relies upon the ability of small molecules to inhibit the binding of fluorescently labelled geldanamycin to Hsp90. We demonstrate that the assay works well with soluble extracts of Brugia, while extracts of the free-living nematode C. elegans fail to bind the probe, in agreement with data from other experiments. The assay was validated using known inhibitors of Hsp90 that compete with geldanamycin for binding to Hsp90, including members of the synthetic purine-scaffold series of compounds. The efficacy of some of these compounds against adult worms was confirmed in vitro. Moreover, the assay is sufficiently sensitive to differentiate between binding of purine-scaffold compounds to human and Brugia Hsp90. The assay is suitable for high-throughput screening and provides the first example of a format with the potential to identify novel inhibitors of Hsp90 in filarial worms and in other parasitic species where Hsp90 may be a target

Development of the Advancing the Patient Experience in COPD Registry:A Modified Delphi Study

Background: Chronic obstructive pulmonary disease (COPD) is commonly managed by family physicians, but little is known about specifics of management and how this may be improved. The Advancing the Patient Experience in COPD (APEX COPD) registry will be the first U.S. primary care, health system-based registry following patients diagnosed with COPD longitudinally, using a standardized set of variables to investigate how patients are managed in real life and assess outcomes of various management strategies.Objective: Gaining expert consensus on a standardized list of variables to capture in the APEX COPD registry.Methods: A modified, Delphi process was used to reach consensus on which data to collect in the registry from electronic health records (EHRs), patient-reported information (PRI) and patient-reported outcomes (PRO), and by physicians during subsequent office visits. The Delphi panel comprised 14 primary care and specialty COPD experts from the United States and internationally. The process consisted of 3 iterative rounds. Responses were collected electronically.Results: Of the initial 195 variables considered, consensus was reached to include up to 115 EHR variables, 34 PRI/PRO variables and 5 office-visit variables in the APEX COPD registry. These should include information on symptom burden, diagnosis, COPD exacerbations, lung function, quality of life, comorbidities, smoking status/history, treatment specifics (including side effects), inhaler management, and patient education/self-management.Conclusion: COPD experts agreed upon the core variables to collect from EHR data and from patients to populate the APEX COPD registry. Data will eventually be integrated, standardized and stored in the APEX COPD database and used for approved COPD-related research.</p

Development of the Advancing the Patient Experience (APEX) in COPD Registry : A Modified Delphi Study

Funding statement: APEX COPD is conducted by Optimum Patient Care (OPC) Global Limited, and co-funded by OPC Global and Boehringer Ingelheim Pharmaceuticals, Inc. (BIPI). The author(s) meet criteria for authorship as recommended by the International Committee of Medical Journal Editors (ICMJE). The authors received no direct compensation related to the development of the manuscript. Writing, editorial support, and/or formatting assistance was provided by Ms. Audrey Ang of the Observational and Pragmatic Research Institute, Singapore, and Dr. Lisa Buttle of Medscript Ltd, Ireland, which was funded by BIPI. BIPI was given the opportunity to review the manuscript for medical and scientific accuracy as well as intellectual property considerations. Acknowledgments The author(s) meet criteria for authorship as recommended by the International Committee of Medical Journal Editors (ICMJE). We thank Dr. Alvaro Aranda (Hospital Auxilio Mutuo, San Juan, Puerto Rico) for his scientific and clinical contributions during the drafting of this manuscript. We also thank Ms. Audrey Ang for editorial assistance, Ms. Bronte Sawyer for project coordination, and Dr. Lisa Buttle for assistance with drafting the article. Dr. Ruth B. Murray is acknowledged for her substantial contribution to the interpretation, summarization and presentation of data in this article and significant intellectual input to the manuscript. She has provided her final approval of the version to be published and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Dr. Ruth B. Murray is the founder and director of Medscript Ltd., a company that provided writing and editorial support for APEX COPD publications.Peer reviewedPostprin

Variation in Demographic and Clinical Characteristics of COPD Patients Managed in U.S. Primary Care : Data from a Real-Life COPD Registry

Peer reviewedPostprin