Publications by authors named "William J Martin"

113 Publications

Screening strategies for identifying RNA- and ribonucleoprotein-targeted compounds.

Trends Pharmacol Sci 2021 Jun 29. Epub 2021 Jun 29.

European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs, Grenoble 38042, France. Electronic address:

The past few years have witnessed important breakthroughs in the identification of compounds that specifically bind and regulate RNAs and in optimizing them for therapeutic use. Here, we review successful and unsuccessful approaches in screening for RNA-targeted small molecules. We discuss advantages and disadvantages of the different screening techniques and variables that affect the outcome of RNA-screening projects. We also highlight key challenges that hamper the development of quality RNA ligands, especially the still-low availability of RNA-specific compound libraries and the poor understanding of RNA structural dynamics. We conclude that the development of new RNA-targeting drugs would greatly benefit from integration of the power of high-throughput screening technologies with improved biochemical, structural, and computational characterization of RNA targets.
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http://dx.doi.org/10.1016/j.tips.2021.06.001DOI Listing
June 2021

Differential effects of novel kappa opioid receptor antagonists on dopamine neurons using acute brain slice electrophysiology.

PLoS One 2020 29;15(12):e0232864. Epub 2020 Dec 29.

BlackThorn Therapeutics, San Francisco, CA, United States of America.

Activation of the kappa opioid receptor (KOR) contributes to the aversive properties of stress, and modulates key neuronal circuits underlying many neurobehavioral disorders. KOR agonists directly inhibit ventral tegmental area (VTA) dopaminergic neurons, contributing to aversive responses (Margolis et al. 2003, 2006); therefore, selective KOR antagonists represent a novel therapeutic approach to restore circuit function. We used whole cell electrophysiology in acute rat midbrain slices to evaluate pharmacological properties of four novel KOR antagonists: BTRX-335140, BTRX-395750, PF-04455242, and JNJ-67953964. Each compound concentration-dependently reduced the outward current induced by the KOR selective agonist U-69,593. BTRX-335140 and BTRX-395750 fully blocked U-69,593 currents (IC50 = 1.2 ± 0.9 and 1.2 ± 1.3 nM, respectively). JNJ-67953964 showed an IC50 of 3.0 ± 4.6 nM. PF-04455242 exhibited partial antagonist activity asymptoting at 55% blockade (IC50 = 6.7 ± 15.1 nM). In 3/8 of neurons, 1 μM PF-04455242 generated an outward current independent of KOR activation. BTRX-335140 (10 nM) did not affect responses to saturating concentrations of the mu opioid receptor (MOR) agonist DAMGO or the delta opioid receptor (DOR) agonist DPDPE, while JNJ-67953964 (10 nM) partially blocked DAMGO and DPDPE responses. Importantly, BTRX-335140 (10 nM) rapidly washed out with complete recovery of U-69,593 responses within 10 min. Collectively, we show electrophysiological evidence of key differences amongst KOR antagonists that could impact their therapeutic potential and have not been observed using recombinant systems. The results of this study demonstrate the value of characterizing compounds in native neuronal tissue and within circuits implicated in the neurobehavioral disorders of interest.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0232864PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7771853PMC
January 2021

Differential Modulation of Ventral Tegmental Area Circuits by the Nociceptin/Orphanin FQ System.

eNeuro 2020 Jul/Aug;7(5). Epub 2020 Oct 19.

UCSF Weill Institute of Neurosciences, Department of Neurology, University of California, San Francisco, San Francisco, CA 94143

The neuropeptide nociceptin/orphanin FQ (N/OFQ) can be released by stressors and is associated with disorders of emotion regulation and reward processing. N/OFQ and its receptor, NOP, are enriched in dopaminergic pathways, and intra-ventricular agonist delivery decreases dopamine levels in the dorsal striatum, nucleus accumbens (NAc), and ventral tegmental area (VTA). We used whole-cell electrophysiology in acute rat midbrain slices to investigate synaptic actions of N/OFQ. N/OFQ was primarily inhibitory, causing outward currents in both immunocytochemically identified dopaminergic (tyrosine hydroxylase positive (TH(+))) and non-dopaminergic (TH(-)) VTA neurons; effect at 1 μm: 20 ± 4 pA. Surprisingly, this effect was mediated by augmentation of postsynaptic GABAR currents, unlike the substantia nigra pars compacta (SNc), where the N/OFQ-induced outward currents were K channel dependent. A smaller population, 17% of all VTA neurons, responded to low concentrations of N/OFQ with inward currents (10 nm: -11 ± 2 pA). Following 100 nm N/OFQ, the response to a second N/OFQ application was markedly diminished in VTA neurons (14 ± 10% of first response) but not in SNc neurons (90 ± 20% of first response). N/OFQ generated outward currents in medial prefrontal cortex (mPFC)-projecting VTA neurons, but inward currents in a subset of posterior anterior cingulate cortex (pACC)-projecting VTA neurons. While N/OFQ inhibited NAc-projecting VTA cell bodies, it had little effect on electrically or optogenetically evoked terminal dopamine release in the NAc measured with fast scan cyclic voltammetry (FSCV). These results extend our understanding of the N/OFQ system in brainstem circuits implicated in many neurobehavioral disorders.
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http://dx.doi.org/10.1523/ENEURO.0376-19.2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7840174PMC
June 2021

Extracellular Vesicles Mediate Neuroprotection and Functional Recovery after Traumatic Brain Injury.

J Neurotrauma 2020 06 10;37(11):1358-1369. Epub 2020 Feb 10.

Regenerative Bioscience Center, University of Georgia, Athens, Georgia, USA.

The lack of effective therapies for moderate-to-severe traumatic brain injuries (TBIs) leaves patients with lifelong disabilities. Neural stem cells (NSCs) have demonstrated great promise for neural repair and regeneration. However, direct evidence to support their use as a cell replacement therapy for neural injuries is currently lacking. We hypothesized that NSC-derived extracellular vesicles (NSC EVs) mediate repair indirectly after TBI by enhancing neuroprotection and therapeutic efficacy of endogenous NSCs. We evaluated the short-term effects of acute intravenous injections of NSC EVs immediately following a rat TBI. Male NSC EV-treated rats demonstrated significantly reduced lesion sizes, enhanced presence of endogenous NSCs, and attenuated motor function impairments 4 weeks post-TBI, when compared with vehicle- and TBI-only male controls. Although statistically not significant, we observed a therapeutic effect of NSC EVs on brain lesion volume, nestin expression, and behavioral recovery in female subjects. Our study demonstrates the neuroprotective and functional benefits of NSC EVs for treating TBI and points to gender-dependent effects on treatment outcomes, which requires further investigation.
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http://dx.doi.org/10.1089/neu.2019.6443DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7249471PMC
June 2020

Systems immunology reveals a linked IgG3-C4 response in patients with acute rheumatic fever.

Immunol Cell Biol 2020 01 18;98(1):12-21. Epub 2019 Nov 18.

School of Medical Sciences, University of Auckland, Auckland, New Zealand.

Acute rheumatic fever (ARF) and chronic rheumatic heart disease (RHD) are autoimmune sequelae of a Group A streptococcal infection with significant global mortality and poorly understood pathogenesis. Immunoglobulin and complement deposition were observed in ARF/RHD valve tissue over 50 years ago, yet contemporary investigations have been lacking. This study applied systems immunology to investigate the relationships between the complement system and immunoglobulin in ARF. Patients were stratified by C-reactive protein (CRP) concentration into high (≥10 μg mL ) and low (<10 μg mL ) groups to distinguish those with clinically significant inflammatory processes from those with abating inflammation. The circulating concentrations of 17 complement factors and six immunoglobulin isotypes and subclasses were measured in ARF patients and highly matched healthy controls using multiplex bead-based immunoassays. An integrative statistical approach combining feature selection and principal component analysis revealed a linked IgG3-C4 response in ARF patients with high CRP that was absent in controls. Strikingly, both IgG3 and C4 were elevated above clinical reference ranges, suggesting these features are a marker of ARF-associated inflammation. Humoral immunity in response to M protein, an antigen implicated in ARF pathogenesis, was completely polarized to IgG3 in the patient group. Furthermore, the anti-M-protein IgG3 response was correlated with circulating IgG3 concentration, highlighting a potential role for this potent immunoglobulin subclass in disease. In conclusion, a linked IgG3-C4 response appears important in the initial, inflammatory stage of ARF and may have immediate utility as a clinical biomarker given the lack of specific diagnostic tests currently available.
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http://dx.doi.org/10.1111/imcb.12298DOI Listing
January 2020

Machine Learning Models Identify Multimodal Measurements Highly Predictive of Transdiagnostic Symptom Severity for Mood, Anhedonia, and Anxiety.

Biol Psychiatry Cogn Neurosci Neuroimaging 2020 01 30;5(1):56-67. Epub 2019 Jul 30.

Computational Psychiatry, BlackThorn Therapeutics, San Francisco, California.

Background: Insights from neuroimaging-based biomarker research have not yet translated into clinical practice. This translational gap may stem from a focus on diagnostic classification, rather than on prediction of transdiagnostic psychiatric symptom severity. Currently, no transdiagnostic, multimodal predictive models of symptom severity that include neurobiological characteristics have emerged.

Methods: We built predictive models of 3 common symptoms in psychiatric disorders (dysregulated mood, anhedonia, and anxiety) from the Consortium for Neuropsychiatric Phenomics dataset (N = 272), which includes clinical scale assessments, resting-state functional magnetic resonance imaging (MRI), and structural MRI measures from patients with schizophrenia, bipolar disorder, and attention-deficit/hyperactivity disorder and healthy control subjects. We used an efficient, data-driven feature selection approach to identify the most predictive features from these high-dimensional data.

Results: This approach optimized modeling and explained 65% to 90% of variance across the 3 symptom domains, compared to 22% without using the feature selection approach. The top performing multimodal models retained a high level of interpretability that enabled several clinical and scientific insights. First, to our surprise, structural features did not substantially contribute to the predictive strength of these models. Second, the Temperament and Character Inventory scale emerged as a highly important predictor of symptom variation across diagnoses. Third, predictive resting-state functional MRI connectivity features were widely distributed across many intrinsic resting-state networks.

Conclusions: Combining resting-state functional MRI with select questions from clinical scales enabled high prediction of symptom severity across diagnostically distinct patient groups and revealed that connectivity measures beyond a few intrinsic resting-state networks may carry relevant information for symptom severity.
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http://dx.doi.org/10.1016/j.bpsc.2019.07.007DOI Listing
January 2020

Therapeutic Approaches for NOP Receptor Antagonists in Neurobehavioral Disorders: Clinical Studies in Major Depressive Disorder and Alcohol Use Disorder with BTRX-246040 (LY2940094).

Handb Exp Pharmacol 2019 ;254:399-415

BlackThorn Therapeutics, San Francisco, CA, USA.

Conventional antidepressants increase the efflux of biogenic amine neurotransmitters (the monoamine hypothesis of depression) in the central nervous system (CNS) and are the principle drugs used to treat major depressive disorder (MDD). However, the lack of efficacy in some patients, the slow onset of action, and the side effect profiles of existing antidepressants necessitate the exploration of additional treatment options. The discovery of the nociceptin/orphanin FQ peptide NOP receptor (N/OFQ-NOP receptor) system and its characterization in preclinical biological and pharmacological stress-related conditions supports the potential antidepressant and anti-stress properties of a NOP receptor antagonist for the treatment of neurobehavioral disorders. BTRX-246040 (formerly LY2940094) was designed to test this hypothesis in the clinic. A small clinical proof of concept study demonstrated efficacy of BTRX-246040 in MDD patients. In this study, BTRX-246040 (40 mg, p.o.) significantly reduced negative bias as assessed by the facial recognition test within 1 week of treatment and decreased depression symptoms after 8 weeks. BTRX-246040 also reduced depression symptoms in a second trial with heavy alcohol drinkers. Given the comorbidity of MDD and alcohol use disorder, a compound with such effects in patients could be a valuable addition to the medications available. A proof of concept study showed efficacy of BTRX-246040 in reducing heavy drinking and increasing the probability of abstinence in individuals diagnosed with alcohol dependence. In addition, plasma levels of gamma-glutamyl transferase were decreased by BTRX-246040 compared to placebo control implying improvement in liver function. Collectively, the clinical data reviewed within this chapter suggest that BTRX-264040 functions to normalize dysfunction in reward circuits. The overall efficacy and safety of this compound with a novel mechanism of action are encouraging of further clinical development. BTRX-246040 is currently under development for MDD by BlackThorn Therapeutics.
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http://dx.doi.org/10.1007/164_2018_186DOI Listing
July 2019

Dysregulated IL-1β-GM-CSF Axis in Acute Rheumatic Fever That Is Limited by Hydroxychloroquine.

Circulation 2018 12;138(23):2648-2661

Divisions of Inflammation (M.L.K., W.J.M., J.L.K., I.P.W.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.

Background: Acute rheumatic fever (ARF) and rheumatic heart disease are autoimmune consequences of group A streptococcus infection and remain major causes of cardiovascular morbidity and mortality around the world. Improved treatment has been stymied by gaps in understanding key steps in the immunopathogenesis of ARF and rheumatic heart disease. This study aimed to identify (1) effector T cell cytokine(s) that might be dysregulated in the autoimmune response of patients with ARF by group A streptococcus, and (2) an immunomodulatory agent that suppresses this response and could be clinically translatable to high-risk patients with ARF.

Methods: The immune response to group A streptococcus was analyzed in peripheral blood mononuclear cells from an Australian Aboriginal ARF cohort by a combination of multiplex cytokine array, flow cytometric analysis, and global gene expression analysis by RNA sequencing. The immunomodulatory drug hydroxychloroquine was tested for effects on this response.

Results: We found a dysregulated interleukin-1β-granulocyte-macrophage colony-stimulating factor (GM-CSF) cytokine axis in ARF peripheral blood mononuclear cells exposed to group A streptococcus in vitro, whereby persistent interleukin-1β production is coupled to overproduction of GM-CSF and selective expansion of CXCR3CCR4CCR6 CD4 T cells. CXCR3CCR4CCR6 CD4 T cells are the major source of GM-CSF in human CD4 T cells and CXCL10, a CXCR3 ligand and potent T helper 1 chemoattractant, was elevated in sera from patients with ARF. GM-CSF has recently emerged as a key T cell-derived effector cytokine in numerous autoimmune diseases, including myocarditis, and the production of CXCL10 may explain selective trafficking of these cells to the heart. We provide evidence that interleukin-1β amplifies the expansion of GM-CSF-expressing CD4 T cells, which is effectively suppressed by hydroxychloroquine. RNA sequencing showed shifts in gene expression profiles and differentially expressed genes in peripheral blood mononuclear cells derived from patients at different clinical stages of ARF.

Conclusions: Given the safety profile of hydroxychloroquine and its clinical pedigree in treating autoimmune diseases such as rheumatoid arthritis, where GM-CSF plays a pivotal role, we propose that hydroxychloroquine could be repurposed to reduce the risk of rheumatic heart disease after ARF.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.118.033891DOI Listing
December 2018

Hierarchy of transcriptomic specialization across human cortex captured by structural neuroimaging topography.

Nat Neurosci 2018 09 6;21(9):1251-1259. Epub 2018 Aug 6.

Department of Physics, Yale University, New Haven, CT, USA.

Hierarchy provides a unifying principle for the macroscale organization of anatomical and functional properties across primate cortex, yet microscale bases of specialization across human cortex are poorly understood. Anatomical hierarchy is conventionally informed by invasive tract-tracing measurements, creating a need for a principled proxy measure in humans. Moreover, cortex exhibits marked interareal variation in gene expression, yet organizing principles of cortical transcription remain unclear. We hypothesized that specialization of cortical microcircuitry involves hierarchical gradients of gene expression. We found that a noninvasive neuroimaging measure-MRI-derived T1-weighted/T2-weighted (T1w/T2w) mapping-reliably indexes anatomical hierarchy, and it captures the dominant pattern of transcriptional variation across human cortex. We found hierarchical gradients in expression profiles of genes related to microcircuit function, consistent with monkey microanatomy, and implicated in neuropsychiatric disorders. Our findings identify a hierarchical axis linking cortical transcription and anatomy, along which gradients of microscale properties may contribute to the macroscale specialization of cortical function.
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http://dx.doi.org/10.1038/s41593-018-0195-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6119093PMC
September 2018

ERS/ATS workshop report on respiratory health effects of household air pollution.

Eur Respir J 2018 01 4;51(1). Epub 2018 Jan 4.

University of California School of Public Health, Berkeley, CA, USA.

Exposure to household air pollution (HAP) from solid fuel combustion affects almost half of the world population. Adverse respiratory outcomes such as respiratory infections, impaired lung growth and chronic obstructive pulmonary disease have been linked to HAP exposure. Solid fuel smoke is a heterogeneous mixture of various gases and particulates. Cell culture and animal studies with controlled exposure conditions and genetic homogeneity provide important insights into HAP mechanisms. Impaired bacterial phagocytosis in exposed human alveolar macrophages possibly mediates several HAP-related health effects. Lung pathological findings in HAP-exposed individuals demonstrate greater small airways fibrosis and less emphysema compared with cigarette smokers. Field studies using questionnaires, air pollution monitoring and/or biomarkers are needed to better establish human risks. Some, but not all, studies suggest that improving cookstove efficiency or venting emissions may be associated with reduced respiratory symptoms, lung function decline in women and severe pneumonia in children. Current studies focus on fuel switching, stove technology replacements or upgrades and air filter devices. Several governments have initiated major programmes to accelerate the upgrade from solid fuels to clean fuels, particularly liquid petroleum gas, which provides research opportunities for the respiratory health community.
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http://dx.doi.org/10.1183/13993003.00698-2017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418845PMC
January 2018

Executive Summary of the NHLBI Workshop Report: Leveraging Current Scientific Advancements to Understand Sarcoidosis Variability and Improve Outcomes.

Ann Am Thorac Soc 2017 Dec;14(Supplement_6):S415-S420

5 Division of Lung Diseases, National Heart, Lung, and Blood Institute, Bethesda, Maryland.

Sarcoidosis is a systemic granulomatous disease that primarily affects the lung; it is associated with significant disparities, more commonly impacting those in the prime of their lives (age 20-50 yr, with a second peak after age 60 yr), black individuals, and women. However, the burden of disease, the ability to diagnose and prognose organ involvement and course, as well as specific treatment options, management options, and disease pathogenesis remain poorly understood. As a result, the National Heart, Lung, and Blood Institute undertook a sarcoidosis workshop, "Leveraging Current Scientific Advancements to Understand Sarcoidosis Variability and Improve Outcomes," to help address these issues by defining the scientific and clinical priorities to improve sarcoidosis care. The overarching recommendations from this workshop are outlined in the following summary and detailed in the accompanying articles. The recommendations included establishing collaborations and networks to conduct research based on consensus definitions of disease phenotypes and standards of care, and to provide clinical outreach to areas with a burden of disease to improve care. These collaborative networks would also serve as the hub to conduct clinical trials of devastating phenotypes (e.g., cardiac, neurologic, and fibrotic disease) not only for treatment but to enhance our understanding of the burden of disease. In addition, the networks would be used to leverage state-of-the-art "omics" and systems biology research, as well as other studies to advance understanding of disease pathogenesis, and development of biomarkers and therapeutic targets, with a goal to translate this information to improve care of individuals with sarcoidosis.
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http://dx.doi.org/10.1513/AnnalsATS.201707-563OTDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5802571PMC
December 2017

AAV-mediated transfer of FKRP shows therapeutic efficacy in a murine model but requires control of gene expression.

Hum Mol Genet 2017 05;26(10):1952-1965

INSERM, U951, INTEGRARE Research Unit, Généthon, Evry, F-91002, France.

Limb Girdle Muscular Dystrophies type 2I (LGMD2I), a recessive autosomal muscular dystrophy, is caused by mutations in the Fukutin Related Protein (FKRP) gene. It has been proposed that FKRP, a ribitol-5-phosphate transferase, is a participant in α-dystroglycan (αDG) glycosylation, which is important to ensure the cell/matrix anchor of muscle fibers. A LGMD2I knock-in mouse model was generated to express the most frequent mutation (L276I) encountered in patients. The expression of FKRP was not altered neither at transcriptional nor at translational levels, but its function was impacted since abnormal glycosylation of αDG was observed. Skeletal muscles were functionally impaired from 2 months of age and a moderate dystrophic pattern was evident starting from 6 months of age. Gene transfer with a rAAV2/9 vector expressing Fkrp restored biochemical defects, corrected the histological abnormalities and improved the resistance to eccentric stress in the mouse model. However, injection of high doses of the vector induced a decrease of αDG glycosylation and laminin binding, even in WT animals. Finally, intravenous injection of the rAAV-Fkrp vector into a dystroglycanopathy mouse model due to Fukutin (Fktn) knock-out indicated a dose-dependent toxicity. These data suggest requirement for a control of FKRP expression in muscles.
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http://dx.doi.org/10.1093/hmg/ddx066DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6251615PMC
May 2017

Passive transfer of interferon-γ over-expressing macrophages enhances resistance of SCID mice to Mycobacterium tuberculosis infection.

Cytokine 2017 07 24;95:70-79. Epub 2017 Feb 24.

Research Service, VA Medical Center - Nebraska/Western Iowa, Omaha, NE, United States; Departments of Internal Medicine and Microbiology and Immunology, University of Nebraska Medical Center, Omaha, NE, United States; Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, NE, United States.

Infection with Mycobacterium tuberculosis (M.tb) is associated with increased deaths worldwide. Alveolar macrophages (AMs) play a critical role in host defense against infection with this pathogen. In this work we tested the hypothesis that passive transfer of normal AMs, IFN-γ activated AMs, or macrophages transduced to over-express IFN-γ into the lungs of immunosuppressed SCID mice, where resident macrophages are present but not functional, would enhance alveolar immunity and increase clearance of pulmonary M.tb infection. Accordingly, SCID mice were infected with M.tb intratracheally (I.T.), following which they received either control macrophages or macrophages overexpressing IFN-γ (J774A.1). The extent of M.tb infection was assessed at 30days post-M.tb infection. SCID mice administered macrophages over-expressing IFN-γ showed a significant decrease in M.tb burden and increased survival compared to J774A.1 control macrophages or untreated mice. This was further associated with a significant increase in IFN-γ and TNF-α mRNA and protein expression, as well as NF-κB (p65) mRNA, in the lungs. The increase in IFN-γ and TNF-α lung levels was inversely proportional to the number of M.tb organisms recovered. These results provide evidence that administration of macrophages overexpressing IFN-γ inhibit M.tb growth in vivo and may enhance host defense against M.tb infection.
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http://dx.doi.org/10.1016/j.cyto.2017.02.009DOI Listing
July 2017

Structural Roles of Noncoding RNAs in the Heart of Enzymatic Complexes.

Biochemistry 2017 Jan 29;56(1):3-13. Epub 2016 Dec 29.

Department of Biochemistry, Vanderbilt University , Nashville, Tennessee 37232, United States.

Over billions of years of evolution, nature has embraced proteins as the major workhorse molecules of the cell. However, nearly every aspect of metabolism is dependent upon how structured RNAs interact with proteins, ligands, and other nucleic acids. Key processes, including telomere maintenance, RNA processing, and protein synthesis, require large RNAs that assemble into elaborate three-dimensional shapes. These RNAs can (i) act as flexible scaffolds for protein subunits, (ii) participate directly in substrate recognition, and (iii) serve as catalytic components. Here, we juxtapose the near atomic level interactions of three ribonucleoprotein complexes: ribonuclease P (involved in 5' pre-tRNA processing), the spliceosome (responsible for pre-mRNA splicing), and telomerase (an RNA-directed DNA polymerase that extends the ends of chromosomes). The focus of this perspective is profiling the structural and dynamic roles of RNAs at the core of these enzymes, highlighting how large RNAs contribute to molecular recognition and catalysis.
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http://dx.doi.org/10.1021/acs.biochem.6b01106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5742481PMC
January 2017

Airway delivery of interferon-γ overexpressing macrophages confers resistance to Mycobacterium avium infection in SCID mice.

Physiol Rep 2016 11 17;4(21). Epub 2016 Nov 17.

College of Public Health, The Ohio State University, Columbus, Ohio.

Mycobacterium avium (M. avium) causes significant pulmonary infection, especially in immunocompromised hosts. Alveolar macrophages (AMs) represent the first line of host defense against infection in the lung. Interferon gamma (IFN-γ) activation of AMs enhances in vitro killing of pathogens such as M. avium We hypothesized that airway delivery of AMs into the lungs of immunodeficient mice infected with M. avium will inhibit M. avium growth in the lung and that this macrophage function is in part IFN-γ dependent. In this study, normal BALB/c and BALB/c SCID mice received M. avium intratracheally while on mechanical ventilation. After 30 days, M. avium numbers increased in a concentration-dependent manner in SCID mice compared with normal BALB/c mice. Airway delivery of IFN-γ-activated BALB/c AMs or J774A.1 macrophages overexpressing IFN-γ into the lungs of SCID mice resulted in a significant decrease in M. avium growth (P < 0.01, both comparisons) and limited dissemination to other organs. In addition, airway delivery of IFN-γ activated AMs and macrophages overexpressing IFN-γ increased the levels of IFN-γ and TNF-α in SCID mice. A similar protective effect against M. avium infection using J774A.1 macrophages overexpressing IFN-γ was observed in IFN-γ knockout mice. These data suggest that administration of IFN-γ activated AMs or macrophages overexpressing IFN-γ may partially restore local alveolar host defense against infections like M. avium, even in the presence of ongoing systemic immunosuppression.
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http://dx.doi.org/10.14814/phy2.13008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5112490PMC
November 2016

G-quadruplex RNA binding and recognition by the lysine-specific histone demethylase-1 enzyme.

RNA 2016 08 8;22(8):1250-60. Epub 2016 Jun 8.

Department of Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0146, USA.

Lysine-specific histone demethylase 1 (LSD1) is an essential epigenetic regulator in metazoans and requires the co-repressor element-1 silencing transcription factor (CoREST) to efficiently catalyze the removal of mono- and dimethyl functional groups from histone 3 at lysine positions 4 and 9 (H3K4/9). LSD1 interacts with over 60 regulatory proteins and also associates with lncRNAs (TERRA, HOTAIR), suggesting a regulatory role for RNA in LSD1 function. We report that a stacked, intramolecular G-quadruplex (GQ) forming TERRA RNA (GG[UUAGGG]8UUA) binds tightly to the functional LSD1-CoREST complex (Kd ≈ 96 nM), in contrast to a single GQ RNA unit ([UUAGGG]4U), a GQ DNA ([TTAGGG]4T), or an unstructured single-stranded RNA. Stabilization of a parallel-stranded GQ RNA structure by monovalent potassium ions (K(+)) is required for high affinity binding to the LSD1-CoREST complex. These data indicate that LSD1 can distinguish between RNA and DNA as well as structured versus unstructured nucleotide motifs. Further, cross-linking mass spectrometry identified the primary location of GQ RNA binding within the SWIRM/amine oxidase domain (AOD) of LSD1. An ssRNA binding region adjacent to this GQ binding site was also identified via X-ray crystallography. This RNA binding interface is consistent with kinetic assays, demonstrating that a GQ-forming RNA can serve as a noncompetitive inhibitor of LSD1-catalyzed demethylation. The identification of a GQ RNA binding site coupled with kinetic data suggests that structured RNAs can function as regulatory molecules in LSD1-mediated mechanisms.
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http://dx.doi.org/10.1261/rna.057265.116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931117PMC
August 2016

From Design to Dissemination: Implementing Community-Based Participatory Research in Postdisaster Communities.

Am J Public Health 2016 07 19;106(7):1235-42. Epub 2016 May 19.

At the time of the study, Maureen Lichtveld, Faye Grimsley, LuAnn White, Natasha Barlow, Shannon DeGruy, and Dorothy Paul were with the School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA. Suzanne Kennedy, Rebecca Z. Krouse, and Herman Mitchell were with Rho Federal Systems Division Inc, Chapel Hill, NC. Jane El-Dahr was with the Department of Pediatrics, Tulane University School of Medicine, New Orleans. Keith Bordelon and Richard D. Cohn were with the Constella Group, LLC, Durham, NC. Yvonne Sterling was with the Health Sciences Center School of Nursing, Louisiana State University, New Orleans. Stacey Denham, Claire Hayes, Margaret Sanders, Mosanda M. Mvula, and Kevin U. Stephens were with the New Orleans Health Department, New Orleans. Eleanor Thornton was with Visionary Consulting Partners, LLC, Fairfax, VA. Patricia Chulada and William J. Martin II were with the National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC.

Objectives: To review how disasters introduce unique challenges to conducting population-based research and community-based participatory research (CBPR).

Methods: From 2007-2009, we conducted the Head-off Environmental Asthma in Louisiana (HEAL) Study in the aftermath of Hurricane Katrina in a Gulf Coast community facing an unprecedented triple burden: Katrina's and other disasters' impact on the environment and health, historic health disparities, and persistent environmental health threats.

Results: The unique triple burden influenced every research component; still, most existing CBPR principles were applicable, even though full adherence was not always feasible and additional tailored principles govern postdisaster settings.

Conclusions: Even in the most challenging postdisaster conditions, CBPR can be successfully designed, implemented, and disseminated while adhering to scientific rigor.
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http://dx.doi.org/10.2105/AJPH.2016.303169DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4984744PMC
July 2016

Adapting and implementing an evidence-based asthma counseling intervention for resource-poor populations.

J Asthma 2016 Oct 6;53(8):825-34. Epub 2016 Apr 6.

d New Orleans Health Department , New Orleans , Louisiana , USA.

Objective: To report implementation strategies and outcomes of an evidence-based asthma counseling intervention. The Head-off Environmental Asthma in Louisiana (HEAL) intervention integrated asthma counseling (AC) capacity and addressed challenges facing children with asthma in post-disaster New Orleans.

Methods: The HEAL intervention enrolled 182 children (4-12 years) with moderate-to-severe persistent asthma. Recruitment occurred from schools in the Greater New Orleans area for one year. Participants received home environmental assessments and tailored asthma counseling sessions during the study period based on the National Cooperative Inner City Asthma Study and the Inner City Asthma Study. Primary (i.e., asthma symptoms) and secondary outcomes (i.e., healthcare utilization) were captured. During the study, changes were made to meet the demands of a post-hurricane and resource-poor environment which included changes to staffing, training, AC tools, and AC sessions.

Results: After study changes were made, the AC visit rate increased by 92.3%. Significant improvements were observed across several adherence measures (e.g., running out of medications (p = 0.009), financial/insurance problems for appointments (p = 0.006), worried about medication side-effects (p = 0.01), felt medications did not work (p < 0.001)). Additionally, an increasing number of AC visits was modestly associated with a greater reduction in symptoms (test-for-trend p = 0.059).

Conclusion: By adapting to the needs of the study population and setting, investigators successfully implemented a counseling intervention that improved participant behaviors and clinical outcomes. The strategies for implementing the AC intervention may serve as a guide for managing asthma and other chronic conditions in resource-poor settings.
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http://dx.doi.org/10.3109/02770903.2016.1155219DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5040354PMC
October 2016

Extracellular Vesicles from Trypanosoma brucei Mediate Virulence Factor Transfer and Cause Host Anemia.

Cell 2016 Jan;164(1-2):246-257

Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA. Electronic address:

Intercellular communication between parasites and with host cells provides mechanisms for parasite development, immune evasion, and disease pathology. Bloodstream African trypanosomes produce membranous nanotubes that originate from the flagellar membrane and disassociate into free extracellular vesicles (EVs). Trypanosome EVs contain several flagellar proteins that contribute to virulence, and Trypanosoma brucei rhodesiense EVs contain the serum resistance-associated protein (SRA) necessary for human infectivity. T. b. rhodesiense EVs transfer SRA to non-human infectious trypanosomes, allowing evasion of human innate immunity. Trypanosome EVs can also fuse with mammalian erythrocytes, resulting in rapid erythrocyte clearance and anemia. These data indicate that trypanosome EVs are organelles mediating non-hereditary virulence factor transfer and causing host erythrocyte remodeling, inducing anemia.
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http://dx.doi.org/10.1016/j.cell.2015.11.051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4715261PMC
January 2016

Women and Lung Disease. Sex Differences and Global Health Disparities.

Am J Respir Crit Care Med 2015 Jul;192(1):11-6

9 University of Pennsylvania, Philadelphia, Pennsylvania.

There is growing evidence that a number of pulmonary diseases affect women differently and with a greater degree of severity than men. The causes for such sex disparity is the focus of this Blue Conference Perspective review, which explores basic cellular and molecular mechanisms, life stages, and clinical outcomes based on environmental, sociocultural, occupational, and infectious scenarios, as well as medical health beliefs. Owing to the breadth of issues related to women and lung disease, we present examples of both basic and clinical concepts that may be the cause for pulmonary disease disparity in women. These examples include those diseases that predominantly affect women, as well as the rising incidence among women for diseases traditionally occurring in men, such as chronic obstructive pulmonary disease. Sociocultural implications of pulmonary disease attributable to biomass burning and infectious diseases among women in low- to middle-income countries are reviewed, as are disparities in respiratory health among sexual minority women in high-income countries. The implications of the use of complementary and alternative medicine by women to influence respiratory disease are examined, and future directions for research on women and respiratory health are provided.
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http://dx.doi.org/10.1164/rccm.201409-1740PPDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4511423PMC
July 2015

Respiratory risks from household air pollution in low and middle income countries.

Lancet Respir Med 2014 Oct 2;2(10):823-60. Epub 2014 Sep 2.

Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, USA. Electronic address:

A third of the world's population uses solid fuel derived from plant material (biomass) or coal for cooking, heating, or lighting. These fuels are smoky, often used in an open fire or simple stove with incomplete combustion, and result in a large amount of household air pollution when smoke is poorly vented. Air pollution is the biggest environmental cause of death worldwide, with household air pollution accounting for about 3·5-4 million deaths every year. Women and children living in severe poverty have the greatest exposures to household air pollution. In this Commission, we review evidence for the association between household air pollution and respiratory infections, respiratory tract cancers, and chronic lung diseases. Respiratory infections (comprising both upper and lower respiratory tract infections with viruses, bacteria, and mycobacteria) have all been associated with exposure to household air pollution. Respiratory tract cancers, including both nasopharyngeal cancer and lung cancer, are strongly associated with pollution from coal burning and further data are needed about other solid fuels. Chronic lung diseases, including chronic obstructive pulmonary disease and bronchiectasis in women, are associated with solid fuel use for cooking, and the damaging effects of exposure to household air pollution in early life on lung development are yet to be fully described. We also review appropriate ways to measure exposure to household air pollution, as well as study design issues and potential effective interventions to prevent these disease burdens. Measurement of household air pollution needs individual, rather than fixed in place, monitoring because exposure varies by age, gender, location, and household role. Women and children are particularly susceptible to the toxic effects of pollution and are exposed to the highest concentrations. Interventions should target these high-risk groups and be of sufficient quality to make the air clean. To make clean energy available to all people is the long-term goal, with an intermediate solution being to make available energy that is clean enough to have a health impact.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5068561PMC
http://dx.doi.org/10.1016/S2213-2600(14)70168-7DOI Listing
October 2014

Older age at rheumatoid arthritis onset and comorbidities correlate with less Health Assessment Questionnaire-Disability Index and Clinical Disease Activity Index response to etanercept in the RADIUS 2 registry.

J Clin Rheumatol 2014 Sep;20(6):301-5

From the *University of California Los Angeles, Los Angeles, CA; †PharmaNet/i3 Strategic Resourcing, Tampa, FL; ‡Amgen Inc, Thousand Oaks, CA; and §VA Greater Los Angeles Geriatrics Research, Education and Clinical Center, Los Angeles, CA.

Background: Controversy exists in understanding the effects of age at onset and comorbidities in predicting rheumatoid arthritis (RA) response to biologic therapy.

Objective: The objective of this study was to investigate the influence of age at onset and number of comorbidities on Health Assessment Questionnaire-Disability Index (HAQ-DI) and Clinical Disease Activity Index (CDAI) responses in active RA patients after 6 months of treatment with etanercept.

Methods: One thousand eight hundred ninety-nine RA patients were assessed after 6 months of etanercept therapy. Patients met the following inclusion criteria: initiated etanercept, continued therapy for at least 6 months, and were not in CDAI low disease activity (LDA) at baseline (CDAI ≤10.0). Changes in HAQ-DI and CDAI scores over 6 months were analyzed across age of onset quintiles. Multivariate regression models evaluated the independent association between both age at onset and number of comorbidities with change in HAQ-DI/CDAI scores or achieving LDA, while accounting for other covariates.

Results: Significant improvements in HAQ-DI and CDAI scores were observed in all age-onset groups, although HAQ-DI improvements were less in older-onset patients. Results of multiple linear regression demonstrated that younger age at onset, higher baseline HAQ-DI/CDAI score, rheumatoid factor positivity, shorter disease duration, and fewer comorbidities at baseline were independently associated with improvement in both HAQ-DI and CDAI scores. Similarly, achieving CDAI LDA after 6 or more months of etanercept was associated with younger age at onset, higher baseline CDAI, shorter disease duration, and fewer comorbidities.

Conclusions: These patients with older-onset RA and more comorbidities clinically improved with etanercept, but had lower odds of achieving CDAI LDA. Age of onset and number of comorbidities may be important in determining RA tumor necrosis factor inhibitor response.
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http://dx.doi.org/10.1097/RHU.0000000000000152DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4560341PMC
September 2014

Pharmacologic characterization of GSK-961081 (TD-5959), a first-in-class inhaled bifunctional bronchodilator possessing muscarinic receptor antagonist and β2-adrenoceptor agonist properties.

J Pharmacol Exp Ther 2014 Oct 6;351(1):190-9. Epub 2014 Aug 6.

Theravance, Inc., South San Francisco, California.

The objective of the present studies was to characterize the pharmacologic properties of GSK-961081 [TD-5959; (R)-1-(3-((2-chloro-4-(((2-hydroxy-2-(8-hydroxy-2-oxo-1,2-dihydroquinolin-5-yl)ethyl)amino)methyl)-5-methoxyphenyl)amino)-3-oxopropyl) piperidin-4-yl [1,1'-biphenyl]-2-ylcarbamate], a novel first-in-class inhaled bifunctional compound possessing both muscarinic antagonist (MA) and β2-adrenoceptor agonist (BA) properties (MABA). In competition radioligand binding studies at human recombinant receptors, GSK-961081 displayed high affinity for hM2 (Ki = 1.4 nM), hM3 muscarinic receptors (Ki = 1.3 nM) and hβ2-adrenoceptors (Ki = 3.7 nM). GSK-961081 behaved as a potent hβ2-adrenoceptor agonist (EC50 = 0.29 nM for stimulation of cAMP levels) with 440- and 320-fold functional selectivity over hβ1- and hβ3-adrenoceptors, respectively. In guinea pig isolated tracheal tissues, GSK-961081 produced smooth muscle relaxation through MA (EC50 = 50.2 nM), BA (EC50=24.6 nM), and MABA (EC50 = 11 nM) mechanisms. In the guinea pig bronchoprotection assay, inhaled GSK-961081 produced potent, dose-dependent inhibition of bronchoconstrictor responses via MA (ED50 = 33.9 µg/ml), BA (ED50 = 14.1 µg/ml), and MABA (ED50 = 6.4 µg/ml) mechanisms. Significant bronchoprotective effects of GSK-961081 were evident in guinea pigs via MA, BA, and MABA mechanisms for up to 7 days after dosing. The lung selectivity index of GSK-961081 in guinea pigs was 55- to 110-fold greater than that of tiotropium with respect to systemic antimuscarinic antisialagogue effects and was 10-fold greater than that of salmeterol with respect to systemic β2-adrenoceptor hypotensive effects. These preclinical findings studies suggest that GSK-961081 has the potential to be a promising next-generation inhaled lung-selective bronchodilator for the treatment of airway diseases, including chronic obstructive pulmonary disease.
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http://dx.doi.org/10.1124/jpet.114.216861DOI Listing
October 2014

Estimating the number of low-income americans exposed to household air pollution from burning solid fuels.

Environ Health Perspect 2014 Aug 9;122(8):806-10. Epub 2014 May 9.

Georgetown University School of Medicine, Georgetown University, Washington, DC, USA.

Background: Exposure to household air pollution (HAP) from inefficient biomass and coal stoves kills nearly 4 million people every year worldwide. HAP is an environmental risk associated with poverty that affects an estimated 3 billion people mostly in low- and middle-income countries.

Objectives: Our goal was to estimate the number of low-income Americans exposed to potentially health-damaging concentrations of HAP.

Methods: We mapped county-level data for the percentage of households using wood, coal, and/or coke as their primary heating fuel along with percent of the population below the federal poverty level. Using U.S. Census data and the likelihood of fugitive emissions as reported in the literature, we estimated the number of low-income Americans potentially exposed to HAP.

Results: Solid fuel is the primary heating source for > 2.5 million U.S. households, or 6.5 million people. The mapping exercise showed several rural areas, primarily in the northern and western regions, that have high levels of solid-fuel use and poverty. We then identified 117 counties with high co-incident poverty and solid-fuel use as high-priority counties for research into potential health risks from HAP. We estimate that between 500,000 and 600,000 low-income people in the United States are likely exposed to HAP from burning solid fuels within their homes.

Conclusion: HAP occurs within the United States and should be further investigated for adverse health risks, especially among those living in areas with rural poverty.
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http://dx.doi.org/10.1289/ehp.1306709DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4123020PMC
August 2014

Relative contributions of norepinephrine and serotonin transporters to antinociceptive synergy between monoamine reuptake inhibitors and morphine in the rat formalin model.

PLoS One 2013 30;8(9):e74891. Epub 2013 Sep 30.

Departments of Pharmacology, Theravance Inc., South San Francisco, California, United States of America.

Multimodal analgesia is designed to optimize pain relief by coadministering drugs with distinct mechanisms of action or by combining multiple pharmacologies within a single molecule. In clinical settings, combinations of monoamine reuptake inhibitors and opioid receptor agonists have been explored and one currently available analgesic, tapentadol, functions as both a µ-opioid receptor agonist and a norepinephrine transporter inhibitor. However, it is unclear whether the combination of selective norepinephrine reuptake inhibition and µ-receptor agonism achieves an optimal antinociceptive synergy. In this study, we assessed the pharmacodynamic interactions between morphine and monoamine reuptake inhibitors that possess different affinities and selectivities for norepinephrine and serotonin transporters. Using the rat formalin model, in conjunction with measurements of ex vivo transporter occupancy, we show that neither the norepinephrine-selective inhibitor, esreboxetine, nor the serotonin-selective reuptake inhibitor, fluoxetine, produce antinociceptive synergy with morphine. Atomoxetine, a monoamine reuptake inhibitor that achieves higher levels of norepinephrine than serotonin transporter occupancy, exhibited robust antinociceptive synergy with morphine. Similarly, a fixed-dose combination of esreboxetine and fluoxetine which achieves comparable levels of transporter occupancy potentiated the antinociceptive response to morphine. By contrast, duloxetine, a monoamine reuptake inhibitor that achieves higher serotonin than norepinephrine transporter occupancy, failed to potentiate the antinociceptive response to morphine. However, when duloxetine was coadministered with the 5-HT3 receptor antagonist, ondansetron, potentiation of the antinociceptive response to morphine was revealed. These results support the notion that inhibition of both serotonin and norepinephrine transporters is required for monoamine reuptake inhibitor and opioid-mediated antinociceptive synergy; yet, excess serotonin, acting via 5-HT3 receptors, may reduce the potential for synergistic interactions. Thus, in the rat formalin model, the balance between norepinephrine and serotonin transporter inhibition influences the degree of antinociceptive synergy observed between monoamine reuptake inhibitors and morphine.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0074891PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3787017PMC
May 2014

Science is dispassionate, we are told.

Authors:
William J Martin

Ann Am Thorac Soc 2013 Aug;10(4):358-9

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http://dx.doi.org/10.1513/AnnalsATS.201306-167EDDOI Listing
August 2013