Publications search

Infection of animal cells by numerous viruses is detected and countered by a variety of means, including recognition of nonself nucleic acids. The zinc finger antiviral protein (ZAP) depletes cytoplasmic RNA that is recognized as foreign in mammalian cells by virtue of its elevated CG dinucleotide content compared with endogenous mRNAs. Here, we determined a crystal structure of a protein-RNA complex containing the N-terminal, 4-zinc finger human (h) ZAP RNA-binding domain (RBD) and a CG dinucleotide-containing RNA target. The structure reveals in molecular detail how hZAP is able to bind selectively to CG-rich RNA. Specifically, the 4 zinc fingers create a basic patch on the hZAP RBD surface. The highly basic second zinc finger contains a pocket that selectively accommodates CG dinucleotide bases. Structure guided mutagenesis, cross-linking immunoprecipitation sequencing assays, and RNA affinity assays show that the structurally defined CG-binding pocket is not required for RNA binding per se in human cells. However, the pocket is a crucial determinant of high-affinity, specific binding to CG dinucleotide-containing RNA. Moreover, variations in RNA-binding specificity among a panel of CG-binding pocket mutants quantitatively predict their selective antiviral activity against a CG-enriched HIV-1 strain. Overall, the hZAP RBD RNA structure provides an atomic-level explanation for how ZAP selectively targets foreign, CG-rich RNA.

The evolution and global transmission of antimicrobial resistance have been well documented for Gram-negative bacteria and health care-associated epidemic pathogens, often emerging from regions with heavy antimicrobial use. However, the degree to which similar processes occur with Gram-positive bacteria in the community setting is less well understood. In this study, we traced the recent origins and global spread of a multidrug-resistant, community-associated Staphylococcus aureus lineage from the Indian subcontinent, the Bengal Bay clone (ST772). We generated whole-genome sequence data of 340 isolates from 14 countries, including the first isolates from Bangladesh and India, to reconstruct the evolutionary history and genomic epidemiology of the lineage. Our data show that the clone emerged on the Indian subcontinent in the early 1960s and disseminated rapidly in the 1990s. Short-term outbreaks in community and health care settings occurred following intercontinental transmission, typically associated with travel and family contacts on the subcontinent, but ongoing endemic transmission was uncommon. Acquisition of a multidrug resistance integrated plasmid was instrumental in the emergence of a single dominant and globally disseminated clade in the early 1990s. Phenotypic data on biofilm, growth, and toxicity point to antimicrobial resistance as the driving force in the evolution of ST772. The Bengal Bay clone therefore combines the multidrug resistance of traditional health care-associated clones with the epidemiological transmission of community-associated methicillin-resistant S. aureus (MRSA). Our study demonstrates the importance of whole-genome sequencing for tracking the evolution of emerging and resistant pathogens. It provides a critical framework for ongoing surveillance of the clone on the Indian subcontinent and elsewhere. IMPORTANCE The Bengal Bay clone (ST772) is a community-associated and multidrug-resistant Staphylococcus aureus lineage first isolated from Bangladesh and India in 2004. In this study, we showed that the Bengal Bay clone emerged from a virulent progenitor circulating on the Indian subcontinent. Its subsequent global transmission was associated with travel or family contact in the region. ST772 progressively acquired specific resistance elements at limited cost to its fitness and continues to be exported globally, resulting in small-scale community and health care outbreaks. The Bengal Bay clone therefore combines the virulence potential and epidemiology of community-associated clones with the multidrug resistance of health care-associated S. aureus lineages. This study demonstrates the importance of whole-genome sequencing for the surveillance of highly antibiotic-resistant pathogens, which may emerge in the community setting of regions with poor antibiotic stewardship and rapidly spread into hospitals and communities across the world.

Persistent alterations of proopiomelanocortin (Pomc) and mu-opioid receptor (Oprm1) activity and stress responses after alcohol are critically involved in vulnerability to alcohol dependency. Gene transcriptional regulation altered by alcohol may play important roles. Mice with genome-wide deletion of neuronal Pomc enhancer1 (nPE1(-/-)), had hypothalamic-specific partial reductions of beta-endorphin and displayed lower alcohol consumption, compared to wildtype littermates (nPE1(+/+)). We used RNA-Seq to measure steady-state nuclear mRNA transcripts of opioid and stress genes in hypothalamus of nPE1(+/+) and nPE1(-/-) mice after 1-day acute withdrawal from chronic excessive alcohol drinking or after water. nPE1(-/-) had lower basal Pomc and Pdyn (prodynorphin) levels compared to nPE1(+/+), coupled with increased basal Oprm1 and Oprk1 (kappa-opioid receptor) levels, and low alcohol drinking increased Pomc and Pdyn to the basal levels of nPE1(+/+) in the water group, without significant effects on Oprm1 and Oprk1. In nPE1(+/+), excessive alcohol intake increased Pomc and Oprm1, with no effect on Pdyn or Oprk1. For stress genes, nPE1(-/-) had lowered basal Oxt (oxytocin) and Avp (arginine vasopressin) that were restored by low alcohol intake to basal levels of nPE1(+/+). In nPE1(+/+), excessive alcohol intake decreased Oxt and Avpi1 (AVP-induced protein1). Functionally examining the effect of pharmacological blockade of mu-opioid receptor, we found that naltrexone reduced excessive alcohol intake in nPE1(+/+), but not nPE1(-/-). Our results provide evidence relevant to the transcriptional profiling of the critical genes in mouse hypothalamus: enhanced opioid and reduced stress gene transcripts after acute withdrawal from excessive alcohol may contribute to altered reward and stress responses.

Background: The development of imaging-based biomarkers has the potential to overcome major challenges in the accurate and reproducible assessment of disease severity and response to novel therapies in Hidradenitis Suppurativa (HS). Understanding the advantages and limitations of existing non-invasive imaging modalities in dermatological disease will aid in the development of hypotheses and inform the design of future studies. Methods: A scoping review was performed using Medline, Embase, Web of Science Databases and evaluation of "gray literature" until June 30, 2019. Citations were examined according to pre-defined inclusion and exclusion criteria. Citations were reviewed by two independent reviewers. Narrative Synthesis was used to summarize data, structured by imaging modality. Results: Non-invasive imaging modalities, such as ultrasound, MRI, RCM, EIS, OCT, and MIT, were identified. Only ultrasound, MRI and MIT have been used in HS. Image modalities vary in image depth, resolution, cost, accessibility and correlation with known aspects of disease activity in HS. Discussion and Conclusion: The benefits and limitations of each imaging modality are products of cost, accessibility, validity and reliability. An additional hurdle to the development of image-based biomarkers in HS is a lack of established analytical benchmarks that can be correlated with existing biological, inflammatory and clinical parameters. This review has identified potential imaging biomarkers, as well as relevant analytical benchmarks that reflect the presence or absence of disease. Further investigation work is needed to analytically and clinically validate these imaging variables in order to identify potential imaging biomarkers in HS.

Disruption of intestinal microbial communities appears to underlie many human illnesses, but the mechanisms that promote this dysbiosis and its adverse consequences are poorly understood. In patients who received allogeneic hematopoietic cell transplantation (allo-HCT), we describe a high incidence of enterococcal expansion, which was associated with graft-versus-host disease (GVHD) and mortality. We found that Enterococcus also expands in the mouse gastrointestinal tract after allo-HCT and exacerbates disease severity in gnotobiotic models. Enterococcus growth is dependent on the disaccharide lactose, and dietary lactose depletion attenuates Enterococcus outgrowth and reduces the severity of GVHD in mice. Allo-HCT patients carrying lactose-nonabsorber genotypes showed compromised clearance of postantibiotic Enterococcus domination. We report lactose as a common nutrient that drives expansion of a commensal bacterium that exacerbates an intestinal and systemic inflammatory disease.

Following oxycodone conditioned place preference (CPP) in naive female and male Sprague Dawley rats, delta-and mu-opioid receptors (DORs and MORs) redistribute in hippocampal CA3 pyramidal cells and GABAergic interneurons in a manner that would promote opioid-associative learning processes, particularly in females. MORs and DORs similarly redistribute in CA3 and hilar neurons following chronic immobilization stress (CIS) in females, but not males, essentially "priming" the opioid system for oxycodone-associative learning. Following CIS, only females acquire oxycodone CPP. The present study determined whether sex and CIS differentially affect the levels of phosphorylated MORs and DORs (pMORs and pDORs) in the hippocampus following oxycodone CPP as phosphorylation is important for opioid receptor internationalization and trafficking. In naive oxycodone-injected (Oxy) female rats, the density of pMOR-immunoreactivity (ir) was increased in CA1 stratum oriens and CA3a,b strata lucidum and radiatum compared to saline-injected (Sal)-females. Additionally, the density of pDOR-ir increased in the pyramidal cell layer and stratum radiatum of CA2/3a in Oxy-males compared to Sal-males. In CIS females that acquire CPP, pDOR-ir levels were increased in the CA2/3a. These findings indicate only rats that acquire oxycodone CPP have activated MORs and DORs in the hippocampus but that the subregion containing activated opioid receptors differs in females and males. These results are consistent with previously observed sex differences in the hippocampal opioid system following Oxy-CPP.

Modern biomedical scientists are often trapped in silos of knowledge and practice, such as those who study brain structure, function and behavior, on the one hand, and body systems and disorders, on the other. Scientists and physicians in each of those silos have not often paid attention to the brain-body communication that leads to multi-morbidity of systemic and brain-related disorders [eg. depression with diabetes or cardiovascular disease]. Outside of biomedicine, social scientists have long recognized the impact of the social and physical environment on individuals and populations but have not usually connected these effects with changes in underlying biology. However, with the rise of epigenetics, science and the public understanding of science is leaving an era in which the DNA sequence was thought to be "destiny" and entering an era where the environment shapes the biology and behavior of individuals and groups through its interactive effects on brain and body. It does so, at least in part, by shaping epigenetically the structure and function of brain and body systems that show a considerable amount of adaptive plasticity throughout development and adult life. This results in substantial individual differences even between identical twins. These individual differences are produced epigenetically by the two-way interaction between the brain and hormones, immune system mediators and the autonomic nervous system. Disorders, then, are often multimorbid involving both brain and body, such as depression with diabetes and cardiovascular disease. It is therefore imperative to incorporate into "precision medicine" a better understanding of how these differences affect the efficacy of pharmacological, behavioral and psychosocial interventions. This article presents an overview of this new synthesis, using as an example emerging evidence about the linkages between systemic inflammation, insulin resistance and mental health and neurodegenerative diseases. (C) 2019 Published by Elsevier Inc.

Conductance in voltage-gated ion channels is regulated by membrane voltage through structural domains known as voltage sensors. A single structural class of voltage sensor domain exists, but two different modes of voltage sensor attachment to the pore occur in nature: domain-swapped and non-domain-swapped. Since the more thoroughly studied Kv1-7, Nav and Cav channels have domain-swapped voltage sensors, much less is known about non-domain-swapped voltage-gated ion channels. In this paper, using cryo-EM, we show that KvAP from Aeropyrum pernix has non-domain-swapped voltage sensors as well as other unusual features. The new structure, together with previous functional data, suggests that KvAP and the Shaker channel, to which KvAP is most often compared, probably undergo rather different voltage-dependent conformational changes when they open.