A cellular atlas of Pitx2-dependent cardiac development.

The Pitx2 gene encodes a homeobox transcription factor that is required for mammalian development. Disruption of PITX2 expression in humans causes congenital heart diseases and is associated with atrial fibrillation; however, the cellular and molecular processes dictated by Pitx2 during cardiac ontogeny remain unclear. To characterize the role of Pitx2 during murine heart development we sequenced over 75,000 single cardiac cell transcriptomes between two key developmental timepoints in control and Pitx2 null embryos. We found that cardiac cell composition was dramatically altered in mutants at both E10.5 and E13.5. Interestingly, the differentiation dynamics of both anterior and posterior second heart field-derived progenitor cells were disrupted in Pitx2 mutants. We also uncovered evidence for defects in left-right asymmetry within atrial cardiomyocyte populations. Furthermore, we were able to detail defects in cardiac outflow tract and valve development associated with Pitx2 Our findings offer insight into Pitx2 function and provide a compilation of gene expression signatures for further detailing the complexities of heart development that will serve as the foundation for future studies of cardiac morphogenesis, congenital heart disease and arrhythmogenesis.

Long-range Pitx2c enhancer-promoter interactions prevent predisposition to atrial fibrillation.

Genome-wide association studies found that increased risk for atrial fibrillation (AF), the most common human heart arrhythmia, is associated with noncoding sequence variants located in proximity to PITX2 Cardiomyocyte-specific epigenomic and comparative genomics uncovered 2 AF-associated enhancers neighboring PITX2 with varying conservation in mice. Chromosome conformation capture experiments in mice revealed that the Pitx2c promoter directly contacted the AF-associated enhancer regions. CRISPR/Cas9-mediated deletion of a 20-kb topologically engaged enhancer led to reduced Pitx2c transcription and AF predisposition. Allele-specific chromatin immunoprecipitation sequencing on hybrid heterozygous enhancer knockout mice revealed that long-range interaction of an AF-associated region with the Pitx2c promoter was required for maintenance of the Pitx2c promoter chromatin state. Long-range looping was mediated by CCCTC-binding factor (CTCF), since genetic disruption of the intronic CTCF-binding site caused reduced Pitx2c expression, AF predisposition, and diminished active chromatin marks on Pitx2 AF risk variants located at 4q25 reside in genomic regions possessing long-range transcriptional regulatory functions directed at PITX2.

Bolstering the Number and Function of HSV-1-Specific CD8+ Effector Memory T Cells and Tissue-Resident Memory T Cells in Latently Infected Trigeminal Ganglia Reduces Recurrent Ocular Herpes Infection and Disease.

HSV type 1 (HSV-1) is a prevalent human pathogen that infects >3.72 billion individuals worldwide and can cause potentially blinding recurrent corneal herpetic disease. HSV-1 establishes latency within sensory neurons of trigeminal ganglia (TG), and TG-resident CD8+ T cells play a critical role in preventing its reactivation. The repertoire, phenotype, and function of protective CD8+ T cells are unknown. Bolstering the apparent feeble numbers of CD8+ T cells in TG remains a challenge for immunotherapeutic strategies. In this study, a comprehensive panel of 467 HLA-A*0201-restricted CD8+ T cell epitopes was predicted from the entire HSV-1 genome. CD8+ T cell responses to these genome-wide epitopes were compared in HSV-1-seropositive symptomatic individuals (with a history of numerous episodes of recurrent herpetic disease) and asymptomatic (ASYMP) individuals (who are infected but never experienced any recurrent herpetic disease). Frequent polyfunctional HSV-specific IFN-γ+CD107a/b+CD44highCD62LlowCD8+ effector memory T cells were detected in ASYMP individuals and were primarily directed against three "ASYMP" epitopes. In contrast, symptomatic individuals have more monofunctional CD44highCD62LhighCD8+ central memory T cells. Furthermore, therapeutic immunization with an innovative prime/pull vaccine, based on priming with multiple ASYMP epitopes (prime) and neurotropic TG delivery of the T cell-attracting chemokine CXCL10 (pull), boosted the number and function of CD44highCD62LlowCD8+ effector memory T cells and CD103highCD8+ tissue-resident T cells in TG of latently infected HLA-A*0201-transgenic mice and reduced recurrent ocular herpes following UV-B-induced reactivation. These findings have profound implications in the development of T cell-based immunotherapeutic strategies to treat blinding recurrent herpes infection and disease.

CXCL10/CXCR3-Dependent Mobilization of Herpes Simplex Virus-Specific CD8+ TEM and CD8+ TRM Cells within Infected Tissues Allows Efficient Protection against Recurrent Herpesvirus Infection and Disease.

Herpes simplex virus 1 (HSV-1) establishes latency within the sensory neurons of the trigeminal ganglia (TG). HSV-specific memory CD8+ T cells play a critical role in preventing HSV-1 reactivation from TG and subsequent virus shedding in tears that trigger recurrent corneal herpetic disease. The CXC chemokine ligand 10 (CXCL10)/CXC chemokine receptor 3 (CXCR3) chemokine pathway promotes T cell immunity to many viral pathogens, but its importance in CD8+ T cell immunity to recurrent herpes has been poorly elucidated. In this study, we determined how the CXCL10/CXCR3 pathway affects TG- and cornea-resident CD8+ T cell responses to recurrent ocular herpesvirus infection and disease using a well-established murine model in which HSV-1 reactivation was induced from latently infected TG by UV-B light. Following UV-B-induced HSV-1 reactivation, a significant increase in both the number and function of HSV-specific CXCR3+ CD8+ T cells was detected in TG and corneas of protected C57BL/6 (B6) mice, but not in TG and corneas of nonprotected CXCL10-/- or CXCR3-/- deficient mice. This increase was associated with a significant reduction in both virus shedding and recurrent corneal herpetic disease. Furthermore, delivery of exogenous CXCL10 chemokine in TG of CXCL10-/- mice, using the neurotropic adeno-associated virus type 8 (AAV8) vector, boosted the number and function of effector memory CD8+ T cells (TEM) and tissue-resident memory CD8+ T cells (TRM), but not of central memory CD8+ T cells (TCM), locally within TG, and improved protection against recurrent herpesvirus infection and disease in CXCL10-/- deficient mice. These findings demonstrate that the CXCL10/CXCR3 chemokine pathway is critical in shaping CD8+ T cell immunity, locally within latently infected tissues, which protects against recurrent herpesvirus infection and disease.IMPORTANCE We determined how the CXCL10/CXCR3 pathway affects CD8+ T cell responses to recurrent ocular herpesvirus infection and disease. Using a well-established murine model, in which HSV-1 reactivation in latently infected trigeminal ganglia was induced by UV-B light, we demonstrated that lack of either CXCL10 chemokine or its CXCR3 receptor compromised the mobilization of functional CD8+ TEM and CD8+ TRM cells within latently infected trigeminal ganglia following virus reactivation. This lack of T cell mobilization was associated with an increase in recurrent ocular herpesvirus infection and disease. Inversely, augmenting the amount of CXCL10 in trigeminal ganglia of latently infected CXCL10-deficient mice significantly restored the number of local antiviral CD8+ TEM and CD8+ TRM cells associated with protection against recurrent ocular herpes. Based on these findings, a novel "prime/pull" therapeutic ocular herpes vaccine strategy is proposed and discussed.

Prior Authorization, Copayments, and Utilization of Sacubitril/Valsartan in Medicare and Commercial Plans in Patients With Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Slow uptake of sacubitril/valsartan in patients with heart failure with reduced ejection fraction has been reported, which may negatively impact clinical outcomes. We characterized prior authorization (PA) burden, prescription copayment, and utilization of sacubitril/valsartan by insurance plan type to identify potential barriers to its use. METHODS: We conducted a national population-level, cross-sectional study using PA data from an insurance coverage website accessed in March 2019 and IQVIA National Prescription Audit data from August 2018 to July 2019. Primary outcomes were proportion of plans requiring PA, frequency of specific PA criteria, number of sacubitril/valsartan prescriptions, and copayments per insurance plan type. RESULTS: Overall, 48.1% (1394/2896) of insurance plans required PA for sacubitril/valsartan. Fewer Medicare (27.7%) than commercial (57.2%) plans required PA (P<0.001). For both plan types, the most frequently required PA criteria were ejection fraction (71.6%, 90.9%) and New York Heart Association class (60.4%, 90.8%) for Medicare and commercial plans, respectively. Copayment amounts varied by plan type, with more sacubitril/valsartan prescriptions for commercial plans not requiring a patient copayment (32.4%) compared with Medicare plans (19.3%; P<0.001). There were 814 437 sacubitril/valsartan prescriptions for Medicare and 822 292 for commercial plans dispensed from August 2018 to July 2019. Based on estimated heart failure with reduced ejection fraction populations for each plan type, 4-fold more sacubitril/valsartan prescriptions were dispensed in commercial than in Medicare plans (820 versus 215 prescriptions/1000 individuals in the heart failure with reduced ejection fraction population). The estimated proportion of heart failure with reduced ejection fraction patients prescribed sacubitril/valsartan was 3.6% (1.5%-6.8%) for Medicare and 13.7% (4.9%-31.8%) for commercial plan populations. CONCLUSIONS: Despite commercial plans having greater PA requirements than Medicare, population-adjusted use of sacubitril/valsartan was higher in commercial plans. Given that commercial plans had more prescriptions with low copayments than Medicare, copayment policies may be more influential on sacubitril/valsartan use than its PA policies. Low sacubitril/valsartan use in both plan types highlights the multifactorial nature of medication underutilization that includes factors beyond the drug policies that we evaluated.

Siamese KG-LSTM: A deep learning model for enriching UMLS Metathesaurus synonymy.

The Unified Medical Language System, or UMLS, is a repository of medical terminology developed by the U.S. National Library of Medicine for improving the computer system's ability of understanding the biomedical and health languages. The UMLS Metathesaurus is one of the three UMLS knowledge sources, containing medical terms and their relationships. Due to the rapid increase in the number of medical terms recently, the current construction of UMLS Metathesaurus, which heavily depends on lexical tools and human editors, is error-prone and time-consuming. This paper takes advantages of the emerging deep learning models for learning to predict the synonyms and non-synonyms between the pairs of biomedical terms in the Metathesaurus. Our learning approach focuses a subset of specific terms instead of the whole Metathesaurus corpus. Particularly, we train the models with biomedical terms from the Disorders semantic group. To strengthen the models, we enrich the inputs with different strategies, including synonyms and hierarchical relationships from source vocabularies. Our deep learning model adopts the Siamese KG-LSTM (Siamese Knowledge Graph - Long Short-Term Memory) in the architecture. The experimental results show that this approach yields excellent performance when handling the task of synonym detection for Disorders semantic group in the Metathesaurus. This shows the potential of applying machine learning techniques in the UMLS Metathesaurus construction process. Although the work in this paper focuses only on specific semantic group of Disorders, we believe that the proposed method can be applied to other semantic groups in the UMLS Metathesaurus.

Synthesis of triphenylpyridines via an oxidative cyclization reaction using Sr-doped LaCoO3 perovskite as a recyclable heterogeneous catalyst.

An La0.6Sr0.4CoO3 strontium-doped lanthanum cobaltite perovskite was prepared via a gelation and calcination approach and used as a heterogeneous catalyst for the synthesis of triphenylpyridines via the cyclization reaction between ketoximes and phenylacetic acids. The transformation proceeded via the oxidative functionalization of the sp3 C-H bond in phenylacetic acid. The La0.6Sr0.4CoO3 catalyst demonstrated a superior performance to that of the pristine LaCoCO3 as well as a series of homogeneous and heterogeneous catalysts. Furthermore, the La0.6Sr0.4CoO3 catalyst was facilely recovered and reused without considerable decline in its catalytic efficiency. To the best of our knowledge, the combination of ketoximes with easily available phenylacetic acids is novel.

Proteolysis of CCN1 by plasmin: functional implications.

Plasmin is shown to play a crucial role in many pathophysiologic processes primarily through its ability to degrade extracellular matrix (ECM) and/or mobilizing growth factors that are sequestered in the ECM. Cysteine-rich 61 (CCN1) is a matricellular protein of which expression is up-regulated in cancer and various vascular diseases. The present study was undertaken to investigate whether plasmin liberates CCN1 from the ECM and whether the released growth factor modulates endothelial cell migration. Treatment of breast carcinoma cells (MDA-MB-231) with plasmin released a truncated form of CCN1 (28 kDa) into the overlying medium. Experiments with recombinant CCN1 confirmed that plasmin effectively cleaves CCN1. Thrombin and other clotting/fibrinolytic proteases are ineffective in cleaving CCN1. Further studies revealed that the conditioned medium of plasmin-treated carcinoma cells supports endothelial cell migration and that antibodies specific to CCN1 blocked this enhancing effect. These data were the first to show that plasmin can liberate a pluripotent matrix signaling protein, CCN1, from the ECM. Because both CCN1 and the components of the plasmin generation system are present in tumor cells and a variety of other cells, the proteolysis of CCN1 by plasmin may play a role in many pathophysiologic processes, including tumor cell-mediated angiogenesis.

Examination of Bottled Water for Nontuberculous Mycobacteria.

The objective of this study was to examine bottled water for the presence of nontuberculous mycobacteria as a potential source of infection in AIDS patients. Twenty brands of bottled water commonly used in the Los Angeles area were tested for the presence of nontuberculous mycobacteria. The three brands most commonly used in the Los Angeles area were tested most frequently. Sixty-nine samples were filtered and the filters were treated using cetylpyridinium chloride, sodium hydroxide, or oxalic acid (or a combination of these) as decontaminants to remove background flora. An aliquot of each sample was untreated. The filters were placed on selective Middlebrook 7H10 agar plates containing 500 µg of cycloheximide per ml. Plates were examined at 3 and 8 weeks. No acid-fast organisms were found. Although no nontuberculous mycobacteria were observed in any samples tested, before recommending the use of bottled water as an alternative to tap water by high-risk patients, the possible presence of other contaminants must be considered.