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Larsen SB, Cowley CJ, Fuchs E
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Epithelial cells: liaisons of immunity

CURRENT OPINION IN IMMUNOLOGY 2020 FEB; 62(?):45-53
The surface and lining tissues of our body are exposed to the external environment, and as such these epithelial tissues must form structural barriers able to defend against microbes, environmental toxins, and mechanical stress. Their cells are equipped to detect a diverse array of surface perturbations, and then launch signaling relays to the immune system. The aim of these liaisons is to coordinate the requisite immune cell response needed to preserve and/or restore barrier integrity and defend the host. It has been recently appreciated that epithelial cells learn from these experiences. Following inflammatory exposure, long-lived stem cells within the tissue retain an epigenetic memory that endows them with heightened responsiveness to subsequent encounters with stress. Here, we review the recent literature on how epithelial cells sense signals from microbes, allergens, and injury at the tissue surface, and transmit this information to immune cells, while embedding a memory of the experience within their chromatin.
Shrestha P, Ayata P, Herrero-Vidal P, Longo F, Gastone A, LeDoux JE, Heintz N, Klann E
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Cell-type-specific drug-inducible protein synthesis inhibition demonstrates that memory consolidation requires rapid neuronal translation

NATURE NEUROSCIENCE 2020 FEB; 23(2):281-292
A chemogenetic approach was developed for cell-type-specific drug-inducible protein synthesis inhibition in mice. It was used to show that consolidation of long-term aversive memories requires rapid neuronal protein synthesis in the amygdala. New protein synthesis is known to be required for the consolidation of memories, yet existing methods of blocking translation lack spatiotemporal precision and cell-type specificity, preventing investigation of cell-specific contributions of protein synthesis. Here we developed a combined knock-in mouse and chemogenetic approach for cell-type-specific drug-inducible protein synthesis inhibition that enables rapid and reversible phosphorylation of eukaryotic initiation factor 2 alpha, leading to inhibition of general translation by 50% in vivo. We use cell-type-specific drug-inducible protein synthesis inhibition to show that targeted protein synthesis inhibition pan-neuronally and in excitatory neurons in the lateral amygdala (LA) impaired long-term memory. This could be recovered with artificial chemogenetic activation of LA neurons, although at the cost of stimulus generalization. Conversely, genetically reducing phosphorylation of eukaryotic initiation factor 2 alpha in excitatory neurons in the LA enhanced memory strength but reduced memory fidelity and behavioral flexibility. Our findings provide evidence for a cell-specific translation program during consolidation of threat memories.
Patke A, Young MW, Axelrod S
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Molecular mechanisms and physiological importance of circadian rhythms

NATURE REVIEWS MOLECULAR CELL BIOLOGY 2020 FEB; 21(2):67-84
Animal circadian rhythms are controlled by central and peripheral molecular clocks, whose components generate oscillations in their own abundance and activity. Insights into how these clocks time the function of organs and tissues is increasing our understanding of animal physiology. To accommodate daily recurring environmental changes, animals show cyclic variations in behaviour and physiology, which include prominent behavioural states such as sleep-wake cycles but also a host of less conspicuous oscillations in neurological, metabolic, endocrine, cardiovascular and immune functions. Circadian rhythmicity is created endogenously by genetically encoded molecular clocks, whose components cooperate to generate cyclic changes in their own abundance and activity, with a periodicity of about a day. Throughout the body, such molecular clocks convey temporal control to the function of organs and tissues by regulating pertinent downstream programmes. Synchrony between the different circadian oscillators and resonance with the solar day is largely enabled by a neural pacemaker, which is directly responsive to certain environmental cues and able to transmit internal time-of-day representations to the entire body. In this Review, we discuss aspects of the circadian clock in Drosophila melanogaster and mammals, including the components of these molecular oscillators, the function and mechanisms of action of central and peripheral clocks, their synchronization and their relevance to human health.
Mighty J, Zhou J, Benito-Martin A, Sauma S, Hanna S, Onwumere O, Shi C, Muntzel M, Sauane M, Young M, Molina H, Cox D, Redenti S
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Analysis of Adult Neural Retina Extracellular Vesicle Release, RNA Transport and Proteomic Cargo

INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE 2020 FEB; 61(2):? Article 30
PURPOSE. Extracellular vesicles (EVs) contain RNA and protein cargo reflective of the genotype and phenotype of the releasing cell of origin. Adult neural retina EV release, RNA transfer, and proteomic cargo are the focus of this study. METHODS. Adult wild-type mouse retinae were cultured and released EV diameters and concentrations quantified using Nanosight. Immunogold transmission electron microscopy (TEM) was used to image EV ultrastructure and marker protein localization. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze retinal cell transcripts present in EVs. Super-resolution microscopy was used to image fluorescent (green) RNA and (red) lipid membrane labeled EVs, released by adult retina, and internalized by isolated retinal cells. Mass spectrometry was used to characterize the proteomes of adult retina and EVs. RESULTS. Adult neural retina released EVs at a rate of 1.42 +/- 0.08 x 10(8)/mL over 5 days, with diameters ranging from 30 to 910 nm. The canonical EV markers CD63 and Tsg101 localized to retinal EVs. Adult retinal and neuronal mRNA species present in both retina and EVs included rhodopsin and the neuronal nuclei marker NeuN. Fluorescently labeled RNA in retinal cells was enclosed in EVs, transported to, and uptaken by co-cultured adult retinal cells. Proteomic analysis revealed 1696 protein species detected only in retinal cells, 957 species shared between retina and EVs, and 82 detected only in EVs. CONCLUSIONS. The adult neural retina constitutively releases EVs with molecular cargo capable of intercellular transport and predicted involvement in biological processes including retinal physiology, mRNA processing, and transcription regulation within the retinal microenvironment.
Islam MS, Zhou Y, Liang L, Nime I, Yan T, Willias SP, Mia MZ, Bei WC, Connerton IF, Fischetti VA, Li JQ
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Application of a Broad Range Lytic Phage LPST94 for Biological Control of Salmonella in Foods

MICROORGANISMS 2020 FEB; 8(2):? Article 247
Salmonella, one of the most common food-borne pathogens, is a significant public health and economic burden worldwide. Lytic phages are viable alternatives to conventional technologies for pathogen biocontrol in food products. In this study, 40 Salmonella phages were isolated from environmentally sourced water samples. We characterized the lytic range against Salmonella and among all isolates, phage LPST94 showed the broadest lytic spectrum and the highest lytic activity. Electron microscopy and genome sequencing indicated that LPST94 belongs to the Ackermannviridae family. Further studies showed this phage is robust, tolerating a wide range of pH (4-12) and temperature (30-60 degrees C) over 60 min. The efficacy of phage LPST94 as a biological control agent was evaluated in various food products (milk, apple juice, chicken breast, and lettuce) inoculated with non-typhoidal Salmonella species at different temperatures. Interestingly, the anti-Salmonella efficacy of phage LPST94 was greater at 4 degrees C than 25 degrees C, although the efficacy varied between different food models. Adding phage LPST94 to Salmonella inoculated milk decreased the Salmonella count by 3 log(10) CFU/mL at 4 degrees C and 0.84 to 2.56 log(10) CFU/mL at 25 degrees C using an MOI of 1000 and 10000, respectively. In apple juice, chicken breast, and lettuce, the Salmonella count was decreased by 3 log(10) CFU/mL at both 4 degrees C and 25 degrees C after applying phage LPST94 at an MOI of 1000 and 10,000, within a timescale of 48 h. The findings demonstrated that phage LPST94 is a promising candidate for biological control agents against pathogenic Salmonella and has the potential to be applied across different food matrices.
Becher T, Riascos-Bernal DF, Kramer DJ, Almonte VM, Chi J, Tong T, Oliveira-Paula GH, Koleilat I, Chen W, Cohen P, Sibinga NES
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Three-Dimensional Imaging Provides Detailed Atherosclerotic Plaque Morphology and Reveals Angiogenesis After Carotid Artery Ligation

CIRCULATION RESEARCH 2020 FEB 28; 126(5):619-632
Rationale: Remodeling of the vessel wall and the formation of vascular networks are dynamic processes that occur during mammalian embryonic development and in adulthood. Plaque development and excessive neointima formation are hallmarks of atherosclerosis and vascular injury. As our understanding of these complex processes evolves, there is a need to develop new imaging techniques to study underlying mechanisms. Objective: We used tissue clearing and light-sheet microscopy for 3-dimensional (3D) profiling of the vascular response to carotid artery ligation and induction of atherosclerosis in mouse models. Methods and Results: Adipo-Clear and immunolabeling in combination with light-sheet microscopy were applied to image carotid arteries and brachiocephalic arteries, allowing for 3D reconstruction of vessel architecture. Entire 3D neointima formations with different geometries were observed within the carotid artery and scored by volumetric analysis. Additionally, we identified a CD31-positive adventitial plexus after ligation of the carotid artery that evolved and matured over time. We also used this method to characterize plaque extent and composition in the brachiocephalic arteries of ApoE-deficient mice on high-fat diet. The plaques exhibited inter-animal differences in terms of plaque volume, geometry, and ratio of acellular core to plaque volume. A 3D reconstruction of the endothelium overlying the plaque was also generated. Conclusions: We present a novel approach to characterize vascular remodeling in adult mice using Adipo-Clear in combination with light-sheet microscopy. Our method reconstructs 3D neointima formation after arterial injury and allows for volumetric analysis of remodeling, in addition to revealing angiogenesis and maturation of a plexus surrounding the carotid artery. This method generates complete 3D reconstructions of atherosclerotic plaques and uncovers their volume, geometry, acellular component, surface, and spatial position within the brachiocephalic arteries. Our approach may be used in a number of mouse models of cardiovascular disease to assess vessel geometry and volume.
Pulina MV, Hopkins M, Haroutunian V, Greengard P, Bustos V
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C99 selectively accumulates in vulnerable neurons in Alzheimer's disease

ALZHEIMERS & DEMENTIA 2020 FEB; 16(2):273-282
Introduction: The levels and distribution of amyloid deposits in the brain does not correlate well with Alzheimer's disease (AD) progression. Therefore, it is likely thatamyloid precursor protein and its proteolytic fragments other than amyloid b (Ab) contribute to the onset of AD. Methods: We developed a sensitive assay adapted to the detection of C99, the direct precursor of b-amyloid. Three postmortem groups were studied: control with normal and stable cognition; patients with moderate AD, and individuals with severe AD. The amount of C99 and A beta was quantified and correlated with the severity of AD. Results: C99 accumulates in vulnerable neurons, and its levels correlate with the degree of cognitive impairment in patients suffering from AD. In contrast, A beta levels are increased in both vulnerable and resistant brain areas. Discussion: These results raise the possibility that C99, rather than A beta plaques, is responsible for the death of nerve cells in AD.
Smith KK, Keyte AL
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Adaptations of the Marsupial Newborn: Birth as an Extreme Environment

ANATOMICAL RECORD-ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY 2020 FEB; 303(2):235-249
At birth a mammalian neonate enters an extreme environment compared to the intrauterine environment in which it has grown. This transition may be particularly extreme in marsupials because they are born at an exceedingly altricial state, after an exceptionally short gestation. Their stage of development must be considered embryonic by almost any criteria. Yet at this very early stage of development marsupials must travel to the teat, attach and suckle, and have basic functioning of all major physiological systems. In this article, we review the adaptations of the marsupial neonate for survival at an embryonic state, showing that the neonate exhibits a mosaic of accelerations and delays of various tissues and organs as well as several special adaptations to produce the functioning newborn. We then discuss the development of the craniofacial region, the body axis and limbs in order to detail some of the major changes to development leading to this uniquely configured neonate. We show that marsupial development arises out of a variety of heterochronies (changes in relative timing of events) and heterotopies (changes in location of specific developmental events) at the genetic, cellular and organ level. We argue that these data support hypotheses that many of the specific patterns seen in marsupial development arise from the basic constraint of embryonic energetic and tissue resources. Finally ideas on the evolutionary context of the marsupial developmental strategy are briefly reviewed. Anat Rec, 2019. (c) 2018 Wiley Periodicals, Inc. Anat Rec, 303:235-249, 2020. (c) 2018 American Association for Anatomy
Freiwald WA
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The neural mechanisms of face processing: cells, areas, networks, and models

CURRENT OPINION IN NEUROBIOLOGY 2020 FEB; 60(?):184-191
Since its discovery, the face-processing network in the brain of the macaque monkey has emerged as a model system that allowed for major neural mechanisms of face recognition to be identified - with implications for object recognition at large. Populations of face cells encode faces through broad tuning curves, whose shapes change over time. Face representations differ qualitatively across faces areas, and we not only understand the global organization of these specializations, but also some of the transformations between face areas, both feed-forward and feed-back, and the computational principles behind face representations and transformations. Facial information is combined with physical features and mnemonic features in extensions of the core network, which forms an early part of the primate social brain.
Paller AS, Bansal A, Simpson EL, Boguniewicz M, Blauvelt A, Siegfried EC, Guttman-Yassky E, Hultsch T, Chen Z, Mina-Osorio P, Lu YF, Rossi AB, He XY, Kamal M, Graham NMH, Pirozzi G, Ruddy M, Eckert L, Gadkari A
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Clinically Meaningful Responses to Dupilumab in Adolescents with Uncontrolled Moderate-to-Severe Atopic Dermatitis: Post-hoc Analyses from a Randomized Clinical Trial

AMERICAN JOURNAL OF CLINICAL DERMATOLOGY 2020 FEB; 21(1):119-131
BackgroundAtopic dermatitis is a chronic inflammatory condition with substantial burden and limited treatment options for adolescents with moderate-to-severe disease. Significantly more patients treated with dupilumab vs. placebo achieved Investigator's Global Assessment 0/1 at week 16.ObjectiveThe objective of this study was to assess the impact of dupilumab treatment vs. placebo on the achievement of clinically meaningful improvements in atopic dermatitis signs, symptoms and quality of life.MethodsR668-AD-1526 LIBERTY AD ADOL was a randomized, double-blinded, parallel-group, phase III clinical trial. Two hundred and fifty-one adolescents with moderate-to-severe atopic dermatitis received dupilumab 300 mg every 4 weeks (q4w; n=84), dupilumab 200 or 300 mg every 2 weeks (q2w; n=82), or placebo (n=85). A post-hoc subgroup analysis was performed on 214 patients with Investigator's Global Assessment >1 at week 16. Measures of atopic dermatitis signs, symptoms, and quality of life were assessed. Clinically meaningful improvement in one or more of three domains of signs, symptoms, and quality of life was defined as an improvement of >= 50% in Eczema Area and Severity Index, >= 3 points in Peak Pruritus Numerical Rating Scale, or >= 6 points in the Children's Dermatology Life Quality Index from baseline.ResultsOf patients receiving dupilumab q2w, 80.5% [66/82] experienced clinically meaningful improvements in atopic dermatitis signs, symptoms, or quality of life at week 16 (vs. placebo, 20/85 [23.5%], difference 57.0% [95% confidence interval 44.5-69.4]; q4w vs. placebo, 53/84 [63.1%], difference 39.6% [95% confidence interval 25.9-53.3]; both p<0.0001). Results were similar in adolescents with Investigator's Global Assessment >1 at week 16 (q2w, 46/62 [74.2%] vs. placebo, 18/83 [21.7%], difference 52.5% [95% confidence interval 38.5-66.6]; q4w, 38/69 [55.1%] vs. placebo, difference 33.4% [95% confidence interval 18.7-48.1]; both p<0.0001).ConclusionsDupilumab provided clinically meaningful improvements in signs, symptoms, and quality of life in adolescents with moderate-to-severe atopic dermatitis among patients with Investigator's Global Assessment >1 at week 16. Treatment responses should be interpreted in the context of such clinically relevant patient-reported outcome measures.