A Germline-Targeting Chimpanzee SIV Envelope Glycoprotein Elicits a New Class of V2-Apex Directed Cross-Neutralizing Antibodies

HIV-1 and its SIV precursors share a broadly neutralizing antibody (bNAb) epitope in variable loop 2 (V2) at the envelope glycoprotein (Env) trimer apex. Here, we tested the immunogenicity of germ line-targeting versions of a chimpanzee SIV (SIVcpz) Env in human V2-apex bNAb heavy-chain precursor-expressing knock-in mice and as chimeric simian-chimpanzee immunodeficiency viruses (SCIVs) in rhesus macaques (RMs). Trimer immunization of knock-in mice induced V2-directed NAbs, indicating activation of V2-apex bNAb precursor-expressing mouse B cells. SCIV infection of RMs elicited high-titer viremia, potent autologous tier 2 neutralizing antibodies, and rapid sequence escape in the canonical V2-apex epitope. Six of seven animals also developed low-titer heterologous plasma breadth that mapped to the V2-apex. Antibody cloning from two of these animals identified multiple expanded lineages with long heavy chain third complementarity determining regions that cross-neutralized as many as 7 of 19 primary HIV-1 strains, but with low potency. Negative stain electron microscopy (NSEM) of members of the two most cross-reactive lineages confirmed V2 targeting but identified an angle of approach distinct from prototypical V2-apex bNAbs, with antibody binding either requiring or inducing an occluded-open trimer. Probing with conformation-sensitive, nonneutralizing antibodies revealed that SCIV-expressed, but not wild-type SIVcpz Envs, as well as a subset of primary HIV-1 Envs, preferentially adopted a more open trimeric state. These results reveal the existence of a cryptic V2 epitope that is exposed in occluded-open SIVcpz and HIV-1 Env trimers and elicits cross-neutralizing responses of limited breadth and potency. IMPORTANCE An effective HIV-1 vaccination strategy will need to stimulate rare precursor B cells of multiple bNAb lineages and affinity mature them along desired pathways. Here, we searched for V2-apex germ line-targeting Envs among a large set of diverse primate lentiviruses and identified minimally modified versions of one chimpanzee SIV Env that bound several human V2-apex bNAb precursors and stimulated one of these in a V2-apex bNAb precursor-expressing knock-in mouse. We also generated chimeric simian-chimpanzee immunodeficiency viruses and showed that they elicit low-titer V2-directed heterologous plasma breadth in six of seven infected rhesus macaques. Characterization of this antibody response identified a new class of weakly cross-reactive neutralizing antibodies that target the V2-apex, but only in occluded-open Env trimers. The existence of this cryptic epitope, which in some Env backgrounds is immunodominant, needs to be considered in immunogen design.

Miat and interacting protein Metadherin maintain a stem-like niche to promote medulloblastoma tumorigenesis and treatment resistance

Long noncoding RNAs (lncRNAs) play essential roles in the development and progression of many cancers. However, the contributions of lncRNAs to medulloblastoma (MB) remain poorly understood. Here, we identify Miat as an lncRNA enriched in the sonic hedgehog group of MB that is required for maintenance of a treatment-resistant stem-like phenotype in the disease. Loss of Miat results in the differentiation of tumor-initiating, stem-like MB cells and enforces the differentiation of tumorigenic stem-like MB cells into a nontumorigenic state. Miat expression in stem-like MB cells also facilitates treatment resistance by down-regulating p53 signaling and impairing radiation-induced cell death, which can be reversed by therapeutic inhibition of Miat using antisense oligonucleotides. Mechanistically, the RNA binding protein Metadherin (Mtdh), previously linked to resistance to cytotoxic therapy in cancer, binds to Miat in stem-like MB cells. Like the loss of Miat, the loss of Mtdh reduces tumorigenicity and increases sensitivity to radiation-induced death in stem-like MB cells. Moreover, Miat and Mtdh function to regulate the biogenesis of several microRNAs and facilitate tumorigenesis and treatment resistance. Taken together, these data reveal an essential role for the lncRNA Miat in sustaining a treatment-resistant pool of tumorigenic stem-like MB cells.

A Unique Spectrum of Spontaneous Tumors in Dino Knockout Mice Identifies Tissue-Specific Requirements for Tumor Suppression

Here, we report that Dino, a lncRNA required for p53 signaling, suppresses spontaneous tumorigenesis in mice. Dino^−/− mice develop significantly more malignant tumors than Dino^+/+ littermate controls, consisting predominantly of sarcomas, B cell lymphomas and additional rare tumors. While the prevalence of lymphomas and sarcomas in Dino^−/− mice is similar to that of mice with p53 loss, important distinctions emerged. p53-null mice predominantly develop T cell lymphomas; however, no spontaneous T cell lymphoma was observed in Dino^−/− mice. Rather than being a phenocopy of the p53-null tumor spectrum, spontaneous tumors in Dino^−/− mice resemble the spectrum of human cancers in which DINO is recurrently silenced by methylation in a manner that is mutually exclusive with TP53 alterations, suggesting that similar tissues in human and mouse require DINO for tumor suppression. Consistent with a tissue-specific role for Dino in tumor suppression, loss of Dino had no impact on the development of radiation-induced T cell lymphoma and oncogene-driven medulloblastoma, tumors that are accelerated by the loss of p53. Taken together, these data indicate that Dino serves as a potent tumor suppressor molecule specific to a select subset of tissues in mice and humans.

Protective mitochondrial fission induced by stress-responsive protein GJA1-20k

The Connexin43 gap junction gene GJA1 has one coding exon, but its mRNA undergoes internal translation to generate N-terminal truncated isoforms of Connexin43 with the predominant isoform being only 20 kDa in size (GJA1-20k). Endogenous GJA1-20k protein is not membrane bound and has been found to increase in response to ischemic stress, localize to mitochondria, and mimic ischemic preconditioning protection in the heart. However, it is not known how GJA1-20k benefits mitochondria to provide this protection. Here, using human cells and mice, we identify that GJA1-20k polymerizes actin around mitochondria which induces focal constriction sites. Mitochondrial fission events occur within about 45 s of GJA1-20k recruitment of actin. Interestingly, GJA1-20k mediated fission is independent of canonical Dynamin-Related Protein 1 (DRP1). We find that GJA1-20k-induced smaller mitochondria have decreased reactive oxygen species (ROS) generation and, in hearts, provide potent protection against ischemia-reperfusion injury. The results indicate that stress responsive internally translated GJA1-20k stabilizes polymerized actin filaments to stimulate non-canonical mitochondrial fission which limits ischemic-reperfusion induced myocardial infarction.

A genome-scale CRISPR interference guide library enables comprehensive phenotypic profiling in yeast

BACKGROUND

CRISPR/Cas9-mediated transcriptional interference (CRISPRi) enables programmable gene knock-down, yielding loss-of-function phenotypes for nearly any gene. Effective, inducible CRISPRi has been demonstrated in budding yeast, and genome-scale guide libraries enable systematic, genome-wide genetic analysis.

RESULTS

We present a comprehensive yeast CRISPRi library, based on empirical design rules, containing 10 distinct guides for most genes. Competitive growth after pooled transformation revealed strong fitness defects for most essential genes, verifying that the library provides comprehensive genome coverage. We used the relative growth defects caused by different guides targeting essential genes to further refine yeast CRISPRi design rules. In order to obtain more accurate and robust guide abundance measurements in pooled screens, we link guides with random nucleotide barcodes and carry out linear amplification by in vitro transcription.

CONCLUSIONS

Taken together, we demonstrate a broadly useful platform for comprehensive, high-precision CRISPRi screening in yeast.

Auxiliary trafficking subunit GJA1-20k protects connexin-43 from degradation and limits ventricular arrhythmias

Connexin-43 (Cx43) gap junctions provide intercellular coupling, which ensures rapid action potential propagation and synchronized heart contraction. Alterations in Cx43 localization and reductions in gap junction coupling occur in failing hearts, contributing to ventricular arrhythmias and sudden cardiac death. Recent reports have found that an internally translated Cx43 isoform, GJA1-20k, is an auxiliary subunit for the trafficking of Cx43 in heterologous expression systems. Here, we have created a mouse model by using CRISPR technology to mutate a single internal translation initiation site in Cx43 (M213L mutation), which generates full-length Cx43, but not GJA1-20k. We found that GJA1M213L/M213L mice had severely abnormal electrocardiograms despite preserved contractile function, reduced total Cx43, and reduced gap junctions, and they died suddenly at 2 to 4 weeks of age. Heterozygous GJA1M213L/WT mice survived to adulthood with increased ventricular ectopy. Biochemical experiments indicated that cytoplasmic Cx43 had a half-life that was 50% shorter than membrane-associated Cx43. Without GJA1-20k, poorly trafficked Cx43 was degraded. The data support that GJA1-20k, an endogenous entity translated independently of Cx43, is critical for Cx43 gap junction trafficking, maintenance of Cx43 protein, and normal electrical function of the mammalian heart.

Analysis of muntjac deer genome and chromatin architecture reveals rapid karyotype evolution

Closely related muntjac deer show striking karyotype differences. Here we describe chromosome-scale genome assemblies for Chinese and Indian muntjacs, Muntiacus reevesi (2n = 46) and Muntiacus muntjak vaginalis (2n = 6/7), and analyze their evolution and architecture. The genomes show extensive collinearity with each other and with other deer and cattle. We identified numerous fusion events unique to and shared by muntjacs relative to the cervid ancestor, confirming many cytogenetic observations with genome sequence. One of these M. muntjak fusions reversed an earlier fission in the cervid lineage. Comparative Hi-C analysis showed that the chromosome fusions on the M. muntjak lineage altered long-range, three-dimensional chromosome organization relative to M. reevesi in interphase nuclei including A/B compartment structure. This reshaping of multi-megabase contacts occurred without notable change in local chromatin compaction, even near fusion sites. A few genes involved in chromosome maintenance show evidence for rapid evolution, possibly associated with the dramatic changes in karyotype.

cBIN1 Score (CS) Identifies Ambulatory HFrEF Patients and Predicts Cardiovascular Events

BACKGROUND

Cardiac Bridging Integrator 1 (cBIN1) is a membrane deformation protein that generates calcium microdomains at cardiomyocyte t-tubules, whose transcription is reduced in heart failure, and is released into blood. cBIN1 score (CS), an inverse index of plasma cBIN1, measures cellular myocardial remodeling. In patients with heart failure with preserved ejection fraction (HFpEF), CS diagnoses ambulatory heart failure and prognosticates hospitalization. The performance of CS has not been tested in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

CS was determined from plasma of patients recruited in a prospective study. Two comparative cohorts consisted of 158 ambulatory HFrEF patients (left ventricular ejection fraction (LVEF) ≤ 40%, 57 ± 10 years, 80% men) and 115 age and sex matched volunteers with no known history of HF. N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations were also analyzed for comparison. CS follows a normal distribution with a median of 0 in the controls, which increases to a median of 1.9 (p < 0.0001) in HFrEF patients. CS correlates with clinically assessed New York Heart Association Class (p = 0.007). During 1-year follow-up, a high CS (≥ 1.9) in patients predicts increased cardiovascular events (43% vs. 26%, p = 0.01, hazard ratio 1.9). Compared to a model with demographics, clinical risk factors, and NT-proBNP, adding CS to the model improved the overall continuous net reclassification improvement (NRI 0.64; 95% CI 0.18-1.10; p = 0.006). Although performance for diagnosis and prognosis was similar to CS, NT-proBNP did not prognosticate between patients whose NT-proBNP values were > 400 pg/ml.

CONCLUSION

CS, which is mechanistically distinct from NT-proBNP, successfully differentiates myocardial health between patients with HFrEF and matched controls. A high CS reflects advanced NYHA stage, pathologic cardiac muscle remodeling, and predicts 1-year risk of cardiovascular events in ambulatory HFrEF patients. CS is a marker of myocardial remodeling in HFrEF patients, independent of volume status.

Machine Learning for Predicting Complications in Head and Neck Microvascular Free Tissue Transfer

OBJECTIVES/HYPOTHESIS

Machine learning (ML) is a type of artificial intelligence wherein a computer learns patterns and associations between variables to correctly predict outcomes. The objectives of this study were to 1) use a ML platform to identify factors important in predicting surgical complications in patients undergoing head and neck free tissue transfer, and 2) compare ML outputs to traditionally employed logistic regression models.

STUDY DESIGN

Retrospective cohort study.

METHODS

Using a dataset of 364 consecutive patients who underwent head and neck microvascular free tissue transfer at a single institution, 14 clinicopathologic characteristics were analyzed using a supervised ML algorithm of ensemble decision trees to predict surgical complications. The relative importance values of each variable in the ML analysis were then compared to logistic regression models.

RESULTS

There were 166 surgical complications, which included bleeding or hematoma in 30 patients (8.2%), fistulae in 25 patients (6.9%), and infection or dehiscence in 52 patients (14.4%). There were 59 take-backs (16.2%), and six total (1.6%) and five partial (1.4%) flap failures. ML models were able to correctly classify outcomes with an accuracy of 65% to 75%. Factors that were identified in ML analyses as most important for predicting complications included institutional experience, flap ischemia time, age, and smoking pack-years. In contrast, the significant factors most frequently identified in traditional logistic regression analyses were patient age (P = .03), flap type (P = .03), and primary site of reconstruction (P = .06).

CONCLUSIONS

In this single-institution dataset, ML algorithms identified factors for predicting complications after free tissue transfer that were distinct from traditional regression models.

LEVEL OF EVIDENCE

2c Laryngoscope, 2020.

Building Community Capacity for Qualitative Research to Improve Pregnancy Intention Screening

BACKGROUND

Community-based participatory research (CBPR), with an emphasis on co-learning and collaboration, holds promise for exploring the pregnancy intention (PI) screening needs of Latina patients and their health care providers. We describe a CBPR partnership exploring PI screening processes at a federally qualified health center in New York City, and lessons learned related to community participation, training, and collaboration between partners.

METHODS

Stakeholders convened a community advisory board (CAB) to carry out CBPR. The CAB administered a biannual process evaluation to assess members' experiences with the project.

RESULTS

Despite challenges, the CAB prioritized community participation, training, and collaboration. At three time points, members reported gaining research skills (93%, 100%, 100%), and believing in the project's potential to improve PI screening (100%, 100%, 100%).

CONCLUSIONS

Building capacity for CBPR requires providing iterative training, navigating discrepancies between CAB members' interests and training needs, facilitating the meaningful participation of members with limited time and/or technical skills, and ensuring an equitable division of labor.

Primary care providers' responses to pregnancy intention screening challenges: community-based participatory research at an urban community health centre

BACKGROUND

Incorporating pregnancy intention screening into primary care to address unmet preconception and contraception needs may improve delivery of family planning services. A notable research gap exists regarding providers' experiences conducting this screening in primary care.

OBJECTIVE

To explore primary care providers' perceived challenges in conducting pregnancy intention screening with women of reproductive age and to identify strategies to discuss this in primary care settings.

METHODS

This qualitative study emerged from a 2017 community-based participatory research project. We conducted semi-structured, in-depth interviews with 10 primary care providers who care for women of reproductive age at an urban federally qualified health centre. Analysis consisted of interview debriefing, transcript coding and content analysis with the Community Advisory Board.

RESULTS

Across departments, respondents acknowledged difficulties conducting pregnancy intention screening and identified strategies for working with patients' individual readiness to discuss pregnancy intention. Strategies included: linking patients' health concerns with sexual and reproductive health, applying a shared decision-making model to all patient-provider interactions, practicing goal setting and motivational interviewing, fostering non-judgmental relationships and introducing pregnancy intention in one visit but following up at later times when more relevant for patients.

CONCLUSIONS

Opportunities exist for health centres to address pregnancy intention screening challenges, such as implementing routine screening and waiting room tools to foster provider and patient agency and sharing best practices with providers across departments by facilitating comprehensive training and periodic check-ins. Exploring providers' experiences may assist health centres in improving pregnancy intention screening in the primary care setting.

Association of a Novel Diagnostic Biomarker, the Plasma Cardiac Bridging Integrator 1 Score, With Heart Failure With Preserved Ejection Fraction and Cardiovascular Hospitalization

Importance

Transverse tubule remodeling is a hallmark of heart failure. Cardiac bridging integrator 1 (cBIN1) is a circulating membrane scaffolding protein that is essential for transverse tubule health, and its plasma level declines with disease.

Objective

To determine if a cBIN1-derived score can serve as a diagnostic biomarker of heart failure with preserved ejection fraction (HFpEF).

Design, Setting, and Participants

In this cohort study, the cBIN1 score (CS) was determined from enzyme-linked immunoabsorbent assay-measured plasma cBIN1 concentrations from study participants in an ambulatory heart failure clinic at Cedars-Sinai Medical Center. Consecutive patients with a confirmed diagnosis of heart failure with preserved ejection fraction (HFpEF; defined by a left ventricular ejection fraction ≥50%) were recruited from July 2014 to November 2015 and compared with age-matched and sex-matched healthy volunteers with no known cardiovascular diagnoses and participants with risk factors for heart failure but no known HFpEF. Baseline characteristics and 1-year longitudinal clinical information were obtained through electronic medical records. Data analysis occurred from November 2016 to November 2017.

Main Outcomes and Measures

The analysis examined the ability of the CS and N-terminal pro-B-type natriuretic peptide (NT-proBNP) results to differentiate among patients with HFpEF, healthy control participants, and control participants with risk factors for heart failure. We further explored the association of the CS with future cardiovascular hospitalizations.

Results

A total of 52 consecutive patients with a confirmed diagnosis of HFpEF were enrolled (mean [SD] age, 57 [15] years; 33 [63%] male). The CS values are significantly higher in the patients with HFpEF (median [interquartile range (IQR)], 1.85 [1.51-2.28]) than in the 2 control cohorts (healthy control participants: median [IQR], -0.03 [-0.48 to 0.41]; control participants with risk factors only: median [IQR], -0.08 [-0.75 to 0.42]; P < .001). For patients with HFpEF, the CS outperforms NT-proBNP when the comparator group was either healthy control participants (CS: area under curve [AUC], 0.98 [95% CI, 0.96-1.00]; NT-proBNP level: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001) or those with risk factors (CS: AUC, 0.98 [95% CI, 0.97-1.00]; NT-proBNP: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001). Kaplan-Meier analysis of 1-year cardiovascular hospitalizations adjusted for age, sex, body mass index, and NT-proBNP levels reveals that patients with HFpEF with CS greater than or equal to 1.80 have a hazard ratio of 3.8 (95% CI, 1.3-11.2; P = .02) for hospitalizations compared with those with scores less than 1.80.

Conclusions and Relevance

If further validated, the plasma CS, a marker of transverse tubule dysfunction, may serve as a biomarker of cardiomyocyte remodeling that has the potential to aide in the diagnosis of HFpEF.

Abstract 544: Gja1-20k Uses the Actin Cytoskeleton to Promote Both Mitochondrial Fission and Fusion

Connexin (Cx) 43 is encoded by the GJA1 gene and GJA1-20k has been identified as an N-terminal truncation of Cx43 generated endogenously by internal translation initiation in heart and other organs. We’ve previously identified that GJA1-20k, which increases with ischemic injury, can organize actin networks and also is strongly co-localized with mitochondria, utilizing the cytoskeleton to preserve mitochondrial distribution during stress. Mitochondrial distribution and morphology are associated with metabolic function, and thus we are interested in how GJA1-20k affects mitochondrial shape and connectivity. We transfected GFP-tagged GJA1-20k plasmids into HEK293T cells and assessed mitochondrial distribution and morphology by fluorescence microscopy. Mitochondria exposed to GJA1-20k are smaller, more circular, and more distributed than mitochondria exposed to a control plasmid. Quantitative image analysis indicates an increase in mitochondrial count but no increase in mitochondrial area, indicating greater mitochondrial fission in the presence of GJA1-20k. Paradoxically, acute disruption of actin with Latrunculin A decreased mitochondrial count, yet increased mitochondrial area, indicating acute fusion. Mitochondrial fusion was also observed by live cell imaging, and with high doses of GJA1-20k. Latrunculin A did not affect mitochondrial morphology in cells without GJA-20k. Together these data suggest that GJA1-20k, a mitochondrial and actin associated scaffold, has multiple effects on mitochondrial morphology. At baseline GJA1-20k promotes mitochondrial-actin association, promoting fission and cellular distribution. Yet, GJA1-20k also promotes mitochondrial membrane-membrane association that, in the presence of actin disruption, resulting in mitochondrial fusion. These data suggest GJA1-20k not only organizes mitochondria under physiologic conditions, but during ischemia, it promotes mitochondrial fusion, enhancing tissue survival during stress.

A systematic literature review of the enabling environment elements to improve implementation of water safety plans in high-income countries

Effective risk management helps ensure safe drinking water and protect public health. Even in high-income countries, risk management sometimes fails and waterborne disease, including outbreaks, occur. To help reduce waterborne disease, the WHO Guidelines for Drinking Water Quality recommend water safety plans (WSPs), a systematic preventive risk management strategy applied from catchment to consumer. Since the introduction of WSPs, international guidelines, national and state legislation, and local practices have facilitated their implementation. While various high-income OECD countries have documented successes in improving drinking water safety through implementing WSPs, others have little experience. This review synthesizes the elements of the enabling environment that promoted the implementation of WSPs in high-income countries. We show that guidelines, regulations, tools and resources, public health support, and context-specific evidence of the feasibility and benefits of WSPs are elements of the enabling environment that encourage adoption and implementation of WSPs in high-income countries. These findings contribute to understanding the ways in which to increase the uptake and extent of WSPs throughout high-income countries to help improve public health.

Cx43 Isoform GJA1-20k Promotes Microtubule Dependent Mitochondrial Transport

Connexin 43 (Cx43, encoded by GJA1) is a cell-cell communication gap junction protein expressed in all organ systems. It was recently found that GJA1 mRNA undergoes alternative translation to generate N-terminal truncated isoforms, of which GJA1-20k is the most abundant. Here we report a surprising finding that, unlike full length GJA1-43k, GJA1-20k has a strong tropism for mitochondria. Exploring function, we found that GJA1-20k appears to be an organelle chaperone and that overexpression of GJA1-20k is sufficient to rescue mitochondrial localization to the cell periphery upon exposure to hydrogen peroxide, which effectively limits the network fragmentation that occurs with oxidative stress. By high-resolution fluorescent imaging and electron microscopy, we determined that GJA1-20k is enriched at the interface between mitochondria and microtubules, appearing to load organelles for transport. Mutagenesis experiments revealed that although the microtubule-binding domain (MTBD) in GJA1-20k is not necessary for protein localization to mitochondria, the MTBD is essential for GJA1-20k to facilitate mitochondrial transport and maintain mitochondrial localization at the periphery. These results reveal an unexpected role for the alternatively translated isoform of the Cx43 gap junction protein, GJA1-20k, which is to facilitate microtubule-based mitochondrial transport and to maintain mitochondrial network integrity during cellular stress.

Abstract 426: Cx43 Isoform GJA1-20k Promotes Microtubule Dependent Mitochondrial Transport

Traditionally, the role of Connexin 43 (Cx43, encoded by GJA1) has been studied in the context of forming gap junctions to mediate cell-cell communication. Cx43 has been implicated in multiple non-canonical roles including metabolic health. It was recently found that GJA1 mRNA undergoes alternative translation to generate truncated C-terminal isoforms, of which GJA1-20k is the most abundant. We examined the relationship between GJA1-20k and mitochondria. Using live cell imaging and organelle markers, we report that, unlike full length GJA1-43k, GJA1-20k has a powerful tropism for mitochondria of all the cell types examined. Mitochondrial enrichment of GJA1-20k was confirmed using biochemical fractionation in transfected cells. High-resolution imaging and immunogold electron microscopy revealed that GJA1-20k is enriched at the interface between mitochondria and microtubules suggesting a role in mitochondrial trafficking. The interaction between GJA1-20k and the microtubules was further confirmed using co-immunoprecipitation. Exploring function, we found that exogenous GJA1-20k is sufficient to rescue mitochondrial localization to the cell periphery upon exposure to hydrogen peroxide, effectively limiting network fragmentation with oxidative stress. Furthermore, we found that the GJA1-20k microtubule-binding domain is unnecessary for mitochondrial localization, but is essential for mediating mitochondrial trafficking and maintaining the integrity of the mitochondrial network and its localization at the cell periphery upon oxidative stress. GJA1-20k enriches in mitochondria and facilitates microtubule-based mitochondrial trafficking, preserving organelle network integrity upon oxidative stress. GJA1-20k provides a means by which otherwise traditional Cx43 can play diverse non-canonical roles. GJA1-20k has therapeutic potential to prevent mitochondrial fragmentation in situations of cellular stress.

Abstract 367: Plasma Based cBIN1 Correlates with Myocardial Health in Heart Failure with Reduced Ejection Fraction

Background: Acquired heart failure (HF) originates with failing heart muscle, yet it is currently not possible to assay the biochemical health of cardiomyocytes. A key pathophysiology of HF is weakened calcium transient under the regulation of a membrane deformation protein bridging integrator 1 (BIN1). BIN1 decreases with HF and is blood available. We hypothesized that a recently cloned cardiac BIN1 isoform (cBIN1, BIN1+13+17) can be selectively measured to diagnose heart muscle health.

Methods: Expression of cBIN1 in human heart and plasma was determined by immunoprecipitation, western blotting, and mass spectrometry analysis. A cBIN1 specific ELISA was developed using the combination of anti-BIN1 exon 17 (clone 99D from Sigma) and 13 (gift from Sarcotein Diagnostics) antibodies. Plasma cBIN1 concentration was then measured in a large clinical cohort of HFrEF (N=180) patients and compared to a sex and age matched cohort of healthy volunteers. Plasma cBIN1 concentration was also compared to NT-proBNP for its ability to detect patients with HFrEF.

Results: Biochemistry and mass spectrometry confirms that cBIN1 is expressed in human myocardium. An ELISA assay selects for the cBIN1 isoform which significantly reduced in HFrEF (3.0±0.3, n=286, mean±SEM, ng/ml, p<0.001) versus matched healthy volunteers (3.0±0.3, n=340). Low plasma cBIN1 diagnoses HFrEF with a ROC area under the curve of 0.92. cBIN1 ROC characteristics are additive to those of NT-proBNP. In addition, low plasma cBIN1 predicts future cardiovascular hospitalization and death over a 12 month follow-up period.

Conclusions: A cBIN1 specific ELISA can quantify cBIN1 in human plasma. Low plasma cBIN1 diagnoses diseased heart muscle in HFrEF patients and predicts future hospitalization and death.

An inducible long noncoding RNA amplifies DNA damage signaling

Long noncoding RNAs (lncRNAs) are prevalent genes with frequently precise regulation but mostly unknown functions. Here we demonstrate that lncRNAs guide the organismal DNA damage response. DNA damage activated transcription of the DINO (Damage Induced Noncoding) lncRNA via p53. DINO was required for p53-dependent gene expression, cell cycle arrest and apoptosis in response to DNA damage, and DINO expression was sufficient to activate damage signaling and cell cycle arrest in the absence of DNA damage. DINO bound to p53 protein and promoted its stabilization, mediating a p53 auto-amplification loop. Dino knockout or promoter inactivation in mice dampened p53 signaling and ameliorated acute radiation syndrome in vivo. Thus, inducible lncRNA can create a feedback loop with its cognate transcription factor to amplify cellular signaling networks.

Water safety plans: bridges and barriers to implementation in North Carolina

First developed by the World Health Organization, and now used in several countries, water safety plans (WSPs) are a multi-step, preventive process for managing drinking water hazards. While the beneficial impacts of WSPs have been documented in diverse countries, how to successfully implement WSPs in the United States remains a challenge. We examine the willingness and ability of water utility leaders to implement WSPs in the US state of North Carolina. Our findings show that water utilities have more of a reactive than preventive organizational culture, that implementation requires prioritization of time and resources, perceived comparative advantage to other hazard management plans, leadership in implementation, and identification of how WSPs can be embedded in existing work practices. Future research could focus on whether WSP implementation provides benefits such as decreases in operational costs, and improved organization of records and communication.

Inflammation in arthritis induces expression of BMP3, an inhibitor of bone formation

OBJECTIVES

Inflammation in diseases such as rheumatoid arthritis (RA) stimulates osteoclast-mediated articular bone erosion and inhibits osteoblast-mediated bone formation, leading to a net loss of bone. Pro-inflammatory cytokines and antagonists of the Wnt signalling pathway have been implicated in the inhibition of osteoblast differentiation and activity in RA, contributing to the erosive process and impairing erosion healing. Importantly, osteoblast differentiation and function are also regulated by the osteogenic bone morphogenetic protein (BMP) signalling pathway, which is antagonized by BMP3. We therefore examined the potential role of BMP3 in inflammatory arthritis.

METHOD

Two murine models of RA, K/BxN serum transfer arthritis (STA) and antigen-induced arthritis (AIA), were used to establish the temporal expression of BMP3 and the cellular sources of BMP3 mRNA and protein in inflammatory arthritis. To determine the effects of inflammation on the expression of BMP3 in osteoblasts, murine calvarial osteoblasts were treated with pro-inflammatory cytokines and BMP3 expression was assessed.

RESULTS

In both murine models of RA, BMP3 mRNA and protein are highly expressed by osteoblasts lining inflammation-bone interfaces late in the course of arthritis. Synovial tissues are not a significant source of BMP3. BMP3 expression is induced in osteocalcin-expressing osteoblasts in vitro following stimulation by tumour necrosis factor (TNF).

CONCLUSIONS

These data implicate BMP3 as a novel factor that may act locally to contribute to the erosive process and inhibit the repair of articular bone in RA through inhibition of osteoblast differentiation and function.

An examination of the potential added value of water safety plans to the United States national drinking water legislation

National and sub-national governments develop and enforce regulations to ensure the delivery of safe drinking water in the United States (US) and countries worldwide. However, periodic contamination events, waterborne endemic illness and outbreaks of waterborne disease still occur, illustrating that delivery of safe drinking water is not guaranteed. In this study, we examined the potential added value of a preventive risk management approach, specifically, water safety plans (WSPs), in the US in order to improve drinking water quality. We undertook a comparative analysis between US drinking water regulations and WSP steps to analyze the similarities and differences between them, and identify how WSPs might complement drinking water regulations in the US. Findings show that US drinking water regulations and WSP steps were aligned in the areas of describing the water supply system and defining monitoring and controls. However, gaps exist between US drinking water regulations and WSPs in the areas of team procedures and training, internal risk assessment and prioritization, and management procedures and plans. The study contributes to understanding both required and voluntary drinking water management practices in the US and how implementing water safety plans could benefit water systems to improve drinking water quality and human health.

Understanding the Views of Those Who Care for Patients With Cancer on Advance Care Planning and End-of-life Care

An electronic survey was used to assess the views of a diverse nationwide cohort of health care professionals regarding advance care planning and end-of-life care. A total of 645 responses were received. If diagnosed with a serious incurable illness with limited life expectancy, 97% would want to discuss their prognosis, 74% would refuse cardiopulmonary resuscitation, and 72% favored supportive/comfort care to more aggressive life-prolonging treatments. However, prognosis was thought to be discussed with only 52% of such patients, and just 5% thought doctors were either very or extremely successful at explaining advanced life-sustaining treatments to patients. Greater than 90% believed these discussions should best occur when a patient is thought to have one or more years to live and 80% thought they are best initiated in the outpatient setting.

Innate type 2 response to Alternaria extract enhances ryegrass-induced lung inflammation

BACKGROUND

Exposure to the fungal allergen Alternaria alternata as well as ryegrass pollen has been implicated in severe asthma symptoms during thunderstorms. We have previously shown that Alternaria extract induces innate type 2 lung inflammation in mice. We hypothesized that the innate eosinophilic response to Alternaria extract may enhance lung inflammation induced by ryegrass.

METHODS

Mice were sensitized to ryegrass allergen and administered a single challenge with A. alternata extract before or after final ryegrass challenges. Levels of eosinophils, neutrophils, Th2 cells, innate lymphoid cells (ILC2), interleukin (IL)-5 and IL-13 in bronchoalveolar lavage (BAL) as well as inflammation and mucus were assessed.

RESULTS

Mice receiving ryegrass sensitization and challenge developed an eosinophilic lung response. A single challenge with Alternaria extract given 3 days before or 3 days after ryegrass challenges resulted in increased eosinophils, peribronchial inflammation and mucus production in the airways compared with ryegrass-only challenges. Type 2 ILC2 and Th2 cell recruitment to the airways was increased after Alternaria extract exposure in ryegrass-challenged mice. Innate immune challenges with Alternaria extract induced BAL eosinophilia, Th2 cell recruitment as well as ILC2 expansion and proliferation.

CONCLUSIONS

A single exposure to Alternaria extract in ryegrass-sensitized and -challenged mice enhances the type 2 lung inflammatory response, including airway eosinophilia, peribronchial infiltrate, and mucus production, possibly through Th2 cell recruitment and ILC2 expansion. If translated to humans, exposure to both grass pollen and Alternaria may be a potential cause of thunderstorm-related asthma.

Assessing the microbial quality of improved drinking water sources: results from the Dominican Republic

Millennium Development Goal Target 7c (to halve between 1990 and 2015 the proportion of the global population without sustainable access to safe drinking water), was celebrated as achieved in 2012. However, new studies show that we may be prematurely celebrating. Access to safe drinking water may be overestimated if microbial water quality is considered. The objective of this study was to examine the relationship between microbial drinking water quality and drinking water source in the Puerto Plata region of the Dominican Republic. This study analyzed microbial drinking water quality data from 409 households in 33 communities. Results showed that 47% of improved drinking water sources were of high to very-high risk water quality, and therefore unsafe for drinking. This study provides evidence that the current estimate of safe water access may be overly optimistic, and microbial water quality data are needed to reliably assess the safety of drinking water.

Impaired induction of allergic lung inflammation by Alternaria alternata mutant MAPK homologue Fus3

The fungal allergen Alternaria alternata is associated with development of asthma, though the mechanisms underlying the allergenicity of Alternaria are largely unknown. The aim of this study was to identify whether the MAP kinase homologue Fus3 of Alternaria contributed to allergic airway responses. Wild-type (WT) and Fus3 deficient Alternaria extracts were given intranasal to mice. Extracts from Fus3 deficient Alternaria that had a functional copy of Fus3 introduced were also administered (CpFus3). Mice were challenged once and levels of BAL eosinophils and innate cytokines IL-33, thymic stromal lymphopoeitin (TSLP), and IL-25 (IL-17E) were assessed. Alternaria extracts or protease-inhibited extract were administered with (OVA) during sensitization prior to ovalbumin only challenges to determine extract adjuvant activity. Levels of BAL inflammatory cells, Th2 cytokines, and OX40-expressing Th2 cells as well as airway infiltration and mucus production were measured. WT Alternaria induced innate airway eosinophilia within 3 days. Mice given Fus3 deficient Alternaria were significantly impaired in developing airway eosinophilia that was largely restored by CpFus3. Further, BAL IL-33, TSLP, and Eotaxin-1 levels were reduced after challenge with Fus3 mutant extract compared with WT and CpFus3 extracts. WT and CpFus3 extracts demonstrated strong adjuvant activity in vivo as levels of BAL eosinophils, Th2 cytokines, and OX40-expressing Th2 cells as well as peribronchial inflammation and mucus production were induced. In contrast, the adjuvant activity of Fus3 extract or protease-inhibited WT extract was largely impaired. Finally, protease activity and Alt a1 levels were reduced in Fus3 mutant extract. Thus, Fus3 contributes to the Th2-sensitizing properties of Alternaria.

Colloid and Interfacial Chemistry at Stuttgart University

The research work carried out in our group can be referred to as “Colloid and Interfacial Chemistry”. We subdivide this rather broad research area into four main topics which are covered by the projects presented in this overview. The surfaces we study are surfactant-loaden water-air surfaces, the films are mainly free-standing thin foam films of less than 100 nm thickness, and the foams are 3D aqueous foams whose stability and drainage we investigate. As regards the topic “Complex Fluids” we study lyotropic liquid crystalline phases and microemulsions. In the past, we were able to establish two new tuning parameters for the formation and destruction of lyotropic liquid crystals, while current research focuses on the lyotropic mesomorphism of new surfactants and of surfactant mixtures. Apart from lyotropic liquid crystals microemulsions are a central theme in the group. Due to their unique properties and fascinating structure variety microemulsions offer a great potential as templates for the synthesis of new functional materials, which is a further research topic in our group. These studies involve the gelation of and the polymerisation in microemulsions preserving their nanostructure to create high surface area polymers. Currently, we also use microemulsions as tailor-made nano-compartmented reaction media. The studied reactions are either enzyme-catalysed conversions of substrates or the reduction of metal salts to synthesize mono- or bimetallic nanoparticles. In this context we focus on bicontinuous and water-in-oil droplet microemulsions. Last but not least we also synthesize new surfactant structures such as inositol-based surfactants and explore the properties.

Sanitation: a global estimate of sewerage connections without treatment and the resulting impact on MDG progress

Progress toward the sanitation component of Millennium Development Goal (MDG) Target 7c was reassessed to account for the need to protect communities and the wider population from exposure to human excreta. We classified connections to sewerage as "improved sanitation" only if the sewage was treated before discharge to the environment. Sewerage connection data was available for 167 countries in 2010; of these, 77 had published data on sewage treatment prevalence. We developed an empirical model to estimate sewage treatment prevalence for 47 additional countries. We estimate that in 2010, 40% of the global population (2.8 billion people) used improved sanitation, as opposed to the estimate of 62% (4.3 billion people) from the WHO/UNICEF Joint Monitoring Programme (JMP), and that 4.1 billion people lacked access to an improved sanitation facility. Redefining sewerage-without-treatment as "unimproved sanitation" in MDG monitoring would raise the 1990 baseline population using unimproved sanitation from 53% to 64% and the corresponding 2015 target from 27% to 32%. At the current rate of progress, we estimate a shortfall of 28 percentage points (1.9 billion people) in 2010 and a projected 27 percentage point shortfall in 2015.

Sanitation: a global estimate of sewerage connections without treatment and the resulting impact on MDG progress

Progress toward the sanitation component of Millennium Development Goal (MDG) Target 7c was reassessed to account for the need to protect communities and the wider population from exposure to human excreta. We classified connections to sewerage as "improved sanitation" only if the sewage was treated before discharge to the environment. Sewerage connection data was available for 167 countries in 2010; of these, 77 had published data on sewage treatment prevalence. We developed an empirical model to estimate sewage treatment prevalence for 47 additional countries. We estimate that in 2010, 40% of the global population (2.8 billion people) used improved sanitation, as opposed to the estimate of 62% (4.3 billion people) from the WHO/UNICEF Joint Monitoring Programme (JMP), and that 4.1 billion people lacked access to an improved sanitation facility. Redefining sewerage-without-treatment as "unimproved sanitation" in MDG monitoring would raise the 1990 baseline population using unimproved sanitation from 53% to 64% and the corresponding 2015 target from 27% to 32%. At the current rate of progress, we estimate a shortfall of 28 percentage points (1.9 billion people) in 2010 and a projected 27 percentage point shortfall in 2015.