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https://www.readbyqxmd.com/read/28634329/long-days-enhance-recognition-memory-and-increase-insulin-like-growth-factor-2-in-the-hippocampus
#1
Adriano Dellapolla, Ian Kloehn, Harshida Pancholi, Ben Callif, David Wertz, Kayla E Rohr, Matthew M Hurley, Kimberly M Baker, Samer Hattar, Marieke R Gilmartin, Jennifer A Evans
Light improves cognitive function in humans; however, the neurobiological mechanisms underlying positive effects of light remain unclear. One obstacle is that most rodent models have employed lighting conditions that cause cognitive deficits rather than improvements. Here we have developed a mouse model where light improves cognitive function, which provides insight into mechanisms underlying positive effects of light. To increase light exposure without eliminating daily rhythms, we exposed mice to either a standard photoperiod or a long day photoperiod...
June 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28628228/epigenetic-mechanisms-underlying-nmda-receptor-hypofunction-in-the-prefrontal-cortex-of-juvenile-animals-in-the-mam-model-for-schizophrenia
#2
Yelena Gulchina, Song-Jun Xu, Melissa A Snyder, Felice Elefant, Wen-Jun Gao
Schizophrenia (SCZ) is characterized not only by psychosis, but also by working memory and executive functioning deficiencies, processes that rely on the prefrontal cortex (PFC). Because these cognitive impairments emerge prior to psychosis onset, we investigated synaptic function during development in the neurodevelopmental methylazoxymethanol acetate (MAM) model for SCZ. Specifically, we hypothesize that NMDAR hypofunction is attributable to reductions in the NR2B subunit through aberrant epigenetic regulation of gene expression, resulting in deficient synaptic physiology and PFC-dependent cognitive dysfunction, a hallmark of SCZ...
June 19, 2017: Journal of Neurochemistry
https://www.readbyqxmd.com/read/28615147/hiv-specific-b-cell-frequency-correlates-with-neutralization-breadth-in-patients-naturally-controlling-hiv-infection
#3
Angeline Rouers, Jéromine Klingler, Bin Su, Assia Samri, Géraldine Laumond, Sophie Even, Véronique Avettand-Fenoel, Clemence Richetta, Nicodème Paul, Faroudy Boufassa, Laurent Hocqueloux, Hugo Mouquet, Christine Rouzioux, Olivier Lambotte, Brigitte Autran, Stéphanie Graff-Dubois, Christiane Moog, Arnaud Moris
HIV-specific broadly neutralizing antibodies (bnAbs) have been isolated from patients with high viremia but also from HIV controllers that repress HIV-1 replication. In these elite controllers (ECs), multiple parameters contribute to viral suppression, including genetic factors and immune responses. Defining the immune correlates associated with the generation of bnAbs may help in designing efficient immunotherapies. In this study, in ECs either positive or negative for the HLA-B*57 protective allele, in treated HIV-infected and HIV-negative individuals, we characterized memory B cell compartments and HIV-specific memory B cells responses using flow cytometry and ELISPOT...
May 31, 2017: EBioMedicine
https://www.readbyqxmd.com/read/28611595/mtorc1-is-a-local-postsynaptic-voltage-sensor-regulated-by-positive-and-negative-feedback-pathways
#4
Farr Niere, Kimberly F Raab-Graham
The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) serves as a regulator of mRNA translation. Recent studies suggest that mTORC1 may also serve as a local, voltage sensor in the postsynaptic region of neurons. Considering biochemical, bioinformatics and imaging data, we hypothesize that the activity state of mTORC1 dynamically regulates local membrane potential by promoting and repressing protein synthesis of select mRNAs. Our hypothesis suggests that mTORC1 uses positive and negative feedback pathways, in a branch-specific manner, to maintain neuronal excitability within an optimal range...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/28607146/epigenetic-transcriptional-memory-of-gal-genes-depends-on-growth-in-glucose-and-the-tup1-transcription-factor-in-saccharomyces-cerevisiae
#5
Varun Sood, Ivelisse Cajigas, Agustina D'Urso, William H Light, Jason H Brickner
Previously expressed inducible genes can remain poised for faster reactivation for multiple cell divisions, a conserved phenomenon called epigenetic transcriptional memory. The GAL genes in Saccharomyces cerevisiae show faster reactivation for up to seven generations after being repressed. During memory, previously produced Gal1 protein enhances the rate of reactivation of GAL1, GAL10, GAL2 and GAL7 These genes also interact with the nuclear pore complex (NPC) and localize to the nuclear periphery both when active and during memory...
June 12, 2017: Genetics
https://www.readbyqxmd.com/read/28587744/mathematical-comparison-of-memory-functions-between-mutual-activation-and-repression-networks-in-a-stochastic-environment
#6
A B M Shamim Ul Hasan, Hiroyuki Kurata
Biological memory is a ubiquitous function that can generate a sustained response to a transient inductive stimulus. To better understand this function, we must consider the mechanisms by which different structures of genetic networks achieve memory. Here, we investigated two competitive gene regulatory network models: the regulated mutual activation network (MAN) and the regulated mutual repression network (MRN). Stochasticity deteriorated the persistence of memory of both the MAN and the MRN. Mathematical comparison by simulation and theoretical analysis identified functional differences in the stochastic memory between the competitive models: specifically, the MAN provided much more robust, persistent memory than the MRN...
June 3, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28580133/the-elephant-shark-methylome-reveals-conservation-of-epigenetic-regulation-across-jawed-vertebrates
#7
Julian R Peat, Oscar Ortega-Recalde, Olga Kardailsky, Timothy A Hore
BACKGROUND: Methylation of CG dinucleotides constitutes a critical system of epigenetic memory in bony vertebrates, where it modulates gene expression and suppresses transposon activity. The genomes of studied vertebrates are pervasively hypermethylated, with the exception of regulatory elements such as transcription start sites (TSSs), where the presence of methylation is associated with gene silencing. This system is not found in the sparsely methylated genomes of invertebrates, and establishing how it arose during early vertebrate evolution is impeded by a paucity of epigenetic data from basal vertebrates...
2017: F1000Research
https://www.readbyqxmd.com/read/28537256/design-of-synthetic-epigenetic-circuits-featuring-memory-effects-and-reversible-switching-based-on-dna-methylation
#8
Johannes A H Maier, Raphael Möhrle, Albert Jeltsch
Epigenetic systems store information in DNA methylation patterns in a durable but reversible manner, but have not been regularly used in synthetic biology. Here, we designed synthetic epigenetic memory systems using DNA methylation sensitive engineered zinc finger proteins to repress a memory operon comprising the CcrM methyltransferase and a reporter. Triggering by heat, nutrients, ultraviolet irradiation or DNA damaging compounds induces CcrM expression and DNA methylation. In the induced on-state, methylation in the operator of the memory operon prevents zinc finger protein binding leading to positive feedback and permanent activation...
May 24, 2017: Nature Communications
https://www.readbyqxmd.com/read/28527130/pulse-generation-in-the-quorum-machinery-of-pseudomonas-aeruginosa
#9
Cicik Alfiniyah, Martin A Bees, A Jamie Wood
Pseudomonas aeruginosa is a Gram-negative bacterium that is responsible for a wide range of infections in humans. Colonies employ quorum sensing (QS) to coordinate gene expression, including for virulence factors, swarming motility and complex social traits. The QS signalling system of P. aeruginosa is known to involve multiple control components, notably the las, rhl and pqs systems. In this paper, we examine the las system and, in particular, the repressive interaction of rsaL, an embedded small regulative protein, employing recent biochemical information to aid model construction...
May 19, 2017: Bulletin of Mathematical Biology
https://www.readbyqxmd.com/read/28511826/use-of-hypnosis-meditation-and-biofeedback-in-dermatology
#10
Philip D Shenefelt
Hypnosis utilizes trance to access otherwise inaccessible repressed or unconscious memories and features of the psyche and control of physiology not attainable in the ordinary conscious waking state. Medical uses of hypnosis in dermatology include reducing discomfort from itching or skin pain, altering ingrained dysfunctional habits such as scratching, promoting healing of skin disorders, searching for psychosomatic aspects of skin disorders and alleviating them, and reframing cognitive and emotional dysfunctional patterns related to skin disorders...
May 2017: Clinics in Dermatology
https://www.readbyqxmd.com/read/28498984/inheritance-of-vernalization-memory-at-flowering-locus-c-during-plant-regeneration
#11
Miyuki Nakamura, Lars Hennig
Specific gene states can be transmitted to subsequent cell generations through mitosis involving particular chromatin (epigenetic) states. During reproduction of plants and animals, however, most epigenetic states are reset to allow development to start anew. Flowering is one of the critical developmental steps by which plants acquire their reproductive capacity. This phase transition is controlled by environmental signals and autonomous regulation. The FLOWERING LOCUS C (FLC) gene is a flowering repressor that is epigenetically silenced after long-term exposure to cold, ensuring flowering in the spring season...
May 11, 2017: Journal of Experimental Botany
https://www.readbyqxmd.com/read/28493559/mtor-referees-memory-and-disease-through-mrna-repression-and-competition
#12
REVIEW
Kimberly F Raab-Graham, Farr Niere
Mammalian target of rapamycin (mTOR) activity is required for memory and is dysregulated in disease. Activation of mTOR promotes protein synthesis; however, new studies are demonstrating that mTOR activity also represses the translation of mRNAs. Almost three decades ago, Kandel and colleagues hypothesised that memory was due to the induction of positive regulators and removal of negative constraints. Are these negative constraints repressed mRNAs that code for proteins that block memory formation? Herein, we will discuss the mRNAs coded by putative memory suppressors, how activation/inactivation of mTOR repress protein expression at the synapse, how mTOR activity regulates RNA binding proteins, mRNA stability, and translation, and what the possible implications of mRNA repression are to memory and neurodegenerative disorders...
May 11, 2017: FEBS Letters
https://www.readbyqxmd.com/read/28461702/bach-transcription-factors-in-innate-and-adaptive-immunity
#13
REVIEW
Kazuhiko Igarashi, Tomohiro Kurosaki, Rahul Roychoudhuri
BTB and CNC homology (BACH) proteins are transcriptional repressors of the basic region leucine zipper (bZIP) transcription factor family. Recent studies indicate widespread roles of BACH proteins in controlling the development and function of the innate and adaptive immune systems, including the differentiation of effector and memory cells of the B and T cell lineages, CD4(+) regulatory T cells and macrophages. Here, we emphasize similarities at a molecular level in the cell-type-specific activities of BACH factors, proposing that competitive interactions of BACH proteins with transcriptional activators of the bZIP family form a common mechanistic theme underlying their diverse actions...
May 2, 2017: Nature Reviews. Immunology
https://www.readbyqxmd.com/read/28443098/the-lysine-methyltransferase-g9a-in-immune-cell-differentiation-and-function
#14
REVIEW
Sebastian Scheer, Colby Zaph
G9a (KMT1C, EHMT2) is a lysine methyltransferase (KMT) whose primary function is to di-methylate lysine 9 of histone H3 (H3K9me2). G9a-dependent H3K9me2 is associated with gene silencing and acts primarily through the recruitment of H3K9me2-binding proteins that prevent transcriptional activation. Gene repression via G9a-dependent H3K9me2 is critically required in embryonic stem (ES) cells for the development of cellular lineages by repressing expression of pluripotency factors. In the immune system, lymphoid cells such as T cells and innate lymphoid cells (ILCs) can differentiate from a naïve state into one of several effector lineages that require both activating and repressive mechanisms to maintain the correct gene expression program...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/28432877/maternal-low-protein-diet-decreases-brain-derived-neurotrophic-factor-expression-in-the-brains-of-the-neonatal-rat-offspring
#15
Gurdeep Marwarha, Kate Claycombe-Larson, Jared Schommer, Othman Ghribi
Prenatal exposure to a maternal low-protein (LP) diet has been known to cause cognitive impairment, learning and memory deficits. However, the underlying mechanisms have not been identified. Herein, we demonstrate that a maternal LP diet causes, in the brains of the neonatal rat offspring, an attenuation in the basal expression of the brain-derived neurotrophic factor (BDNF), a neurotrophin indispensable for learning and memory. Female rats were fed either a 20% normal protein (NP) diet or an 8% LP 3 weeks before breeding and during the gestation period...
July 2017: Journal of Nutritional Biochemistry
https://www.readbyqxmd.com/read/28432781/cognitive-functioning-and-emotion-processing-in-breast-cancer-survivors-and-controls-an-erp-pilot-study
#16
Janine Wirkner, Mathias Weymar, Andreas Löw, Carmen Hamm, Anne-Marie Struck, Clemens Kirschbaum, Alfons O Hamm
Diagnosis and treatment of breast cancer is a very emotionally aversive and stressful life event, which can lead to impaired cognitive functioning and mental health. Breast cancer survivors responding with repressive emotion regulation strategies often show less adaptive coping and adverse outcomes. We investigated cognitive functioning and neural correlates of emotion processing using ERPs. Self-report measures of depression, anxiety, and fatigue, as well as hair cortisol as an index of chronic stress, were assessed...
April 22, 2017: Psychophysiology
https://www.readbyqxmd.com/read/28430857/repurposed-drugs-targeting-eif2-alpha-p-mediated-translational-repression-prevent-neurodegeneration-in-mice
#17
Mark Halliday, Helois Radford, Karlijn A M Zents, Collin Molloy, Julie A Moreno, Nicholas C Verity, Ewan Smith, Catharine A Ortori, David A Barrett, Martin Bushell, Giovanna R Mallucci
See Mercado and Hetz (doi:10.1093/brain/awx107) for a scientific commentary on this article.Signalling through the PERK/eIF2α-P branch of the unfolded protein response plays a critical role in controlling protein synthesis rates in cells. This pathway is overactivated in brains of patients with Alzheimer’s disease and related disorders and has recently emerged as a promising therapeutic target for these currently untreatable conditions. Thus, in mouse models of neurodegenerative disease, prolonged overactivation of PERK/eIF2α-P signalling causes sustained attenuation of protein synthesis, leading to memory impairment and neuronal loss...
June 1, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28428426/transgenerational-transmission-of-environmental-information-in-c-elegans
#18
Adam Klosin, Eduard Casas, Cristina Hidalgo-Carcedo, Tanya Vavouri, Ben Lehner
The environment experienced by an animal can sometimes influence gene expression for one or a few subsequent generations. Here, we report the observation that a temperature-induced change in expression from a Caenorhabditis elegans heterochromatic gene array can endure for at least 14 generations. Inheritance is primarily in cis with the locus, occurs through both oocytes and sperm, and is associated with altered trimethylation of histone H3 lysine 9 (H3K9me3) before the onset of zygotic transcription. Expression profiling reveals that temperature-induced expression from endogenous repressed repeats can also be inherited for multiple generations...
April 21, 2017: Science
https://www.readbyqxmd.com/read/28426734/study-of-deaths-by-suicide-of-homosexual-prisoners-in-nazi-sachsenhausen-concentration-camp
#19
Esther Cuerda-Galindo, Francisco López-Muñoz, Matthis Krischel, Astrid Ley
Living conditions in Nazi concentration camps were harsh and inhumane, leading many prisoners to commit suicide. Sachsenhausen (Oranienburg, Germany) was a concentration camp that operated from 1936 to 1945. More than 200,000 people were detained there under Nazi rule. This study analyzes deaths classified as suicides by inmates in this camp, classified as homosexuals, both according to the surviving Nazi files. This collective was especially repressed by the Nazi authorities. Data was collected from the archives of Sachsenhausen Memorial and the International Tracing Service in Bad Arolsen...
2017: PloS One
https://www.readbyqxmd.com/read/28410989/polycomb-repressive-complex-2-mediated-chromatin-repression-guides-effector-cd8-t-cell-terminal-differentiation-and-loss-of-multipotency
#20
Simon M Gray, Robert A Amezquita, Tianxia Guan, Steven H Kleinstein, Susan M Kaech
Understanding immunological memory formation depends on elucidating how multipotent memory precursor (MP) cells maintain developmental plasticity and longevity to provide long-term immunity while other effector cells develop into terminally differentiated effector (TE) cells with limited survival. Profiling active (H3K27ac) and repressed (H3K27me3) chromatin in naive, MP, and TE CD8(+) T cells during viral infection revealed increased H3K27me3 deposition at numerous pro-memory and pro-survival genes in TE relative to MP cells, indicative of fate restriction, but permissive chromatin at both pro-memory and pro-effector genes in MP cells, indicative of multipotency...
April 18, 2017: Immunity
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