The rockefeller university

Gestational ex posure to a fat-rich diet, while elevating maternal circulating fatty acids, increases in the offspring's hypothalamus and amygdala the proliferation and density of neurons that express neuropeptides known to stimulate consummatory behavior. To understand the relationship between these phenomena, this study examined in the brain of postnatal offspring (day 15) the effect of prenatal fat exposure on the transcription factor, peroxisome proliferator-activated receptor (PPAR) beta/delta, which is sensitive to fatty acids, and the relationship of PPAR beta/delta to the orexigenic neuropeptides, orexin, melanin-concentrating hormone, and enkephalin. Prenatal exposure to a fat-rich diet compared to low-fat chow increased the density of cells immunoreactive for PPAR beta/delta in the hypothalamic paraventricular nucleus (PVN), perifornical lateral hypothalamus (PFLH), and central nucleus of the amygdala (CeA), but not the hypothalamic arcuate nucleus or basolateral amygdaloid nucleus. It also increased co-labeling of PPAR beta/delta with the cell proliferation marker, BrdU, or neuronal marker, NeuN, and the triple labeling of PPAR beta/delta with BrdU plus NeuN, indicating an increase in proliferation and density of new PPAR beta/delta neurons. Prenatal fat exposure stimulated the double-labeling of PPAR beta/delta with orexin or melanin-concentrating hormone in the PFLH and enkephalin in the PVN and CeA and also triple-labeling of PPAR beta/delta with BrdU and these neuropeptides, indicating that dietary fat increases the genesis of PPAR beta/delta neurons that produce these peptides. These findings demonstrate a close anatomical relationship between PPAR beta/delta and the increased proliferation and density of peptide-expressing neurons in the hypothalamus and amygdala of fat-exposed offspring. (C) 2016 Elsevier Inc. All rights reserved.

Purpose of review Over the last several years, novel immunologic pathways pivotal in the development of the pathobiology of psoriasis and psoriatic arthritis (PsA) have been revealed. These discoveries catalyzed a search for new treatment targets resulting in many new therapies that are now available for patients with psoriatic disease. Recent findings Helper T cells that secrete interleukin-17 (TH17) along with CD8+ cells, innate lymphocyte cells, and gamma delta T cells are important in the pathogenesis of psoriasis and PsA. Recently, agents that target interleukin-17, the interleukin-17 receptor, and interleukin-23 (antip19) have been approved or are in clinical trials. Apremilast, a new oral agent, was approved for the treatment of psoriasis and PsA. Secukinumab, an interleukin-17A antibody, has been approved for treatment of psoriasis and PsA in the United States. It is effective with a good safety profile. Ixekizumab, another anti-interleukin-17A antibody, is currently in clinical trials and brodalumab, an interleukin-17 receptor antagonist, was removed from clinical trials because of safety concerns despite demonstrated efficacy in psoriasis and PsA. Targeting interleukin-23 with antibodies to p19 is another approach with encouraging results in psoriasis. Apremilast, an oral agent, approved to treat psoriasis and PsA demonstrates moderate efficacy with an excellent safety record. The role of tofacitinib in psoriatic disease remains to be determined pending a safety review in psoriasis and completion of PsA trials.

The neuron specific RNA-binding proteins NOVA1 and NOVA2 are highly homologous alternative splicing regulators. NOVA proteins regulate at least 700 alternative splicing events in vivo, yet relatively little is known about the biologic consequences of NOVA action and in particular about functional differences between NOVA1 and NOVA2. Transcriptome-wide searches for isoform-specific functions, using NOVA1 and NOVA2 specific HITS-CLIP and RNA-seq data from mouse cortex lacking either NOVA isoform, reveals that NOVA2 uniquely regulates alternative splicing events of a series of axon guidance related genes during cortical development. Corresponding axonal pathfinding defects were specific to NOVA2 deficiency: Nova2-/- but not Nova1-/- mice had agenesis of the corpus callosum, and axonal outgrowth defects specific to ventral motoneuron axons and efferent innervation of the cochlea. Thus we have discovered that NOVA2 uniquely regulates alternative splicing of a coordinate set of transcripts encoding key components in cortical, brainstem and spinal axon guidance/outgrowth pathways during neural differentiation, with severe functional consequences in vivo.

Background: Caregiver burden associated with caring for women with ovarian cancer has received limited focus. However, these patients often have complex needs, requiring a high level of care at home and imposing substantial burdens on caregivers. Objectives: This pilot study assessed the level of caregiver burden experienced by the primary caregivers of patients with end-stage ovarian cancer and identified variables associated with caregiver burden. Methods: Caregiver burden was assessed using the Caregiver Reaction Assessment. Fifty caregivers completed an anonymous and voluntary survey. Pearson correlations and independent samples t tests were used to analyze data. Findings: Most participants were Caucasian, married or living with a partner, and college graduates, with an annual household income of less than $90,000. Caregiver ages ranged from 29-81 years. Participants agreed most with the self-esteem scale, indicating they had pride in caring for their loved ones. Disrupted schedules and financial problems were the most burdensome factors in providing care. Because financial issues affected caregiver burden, nurses should facilitate interdisciplinary support. Future research is needed to determine the impact of nurse-led interventions to reduce caregiver burden.

Due to their central role in essential physiological processes, potassium channels are common targets for animal toxins. These toxins in turn are of great value as tools for studying channel function and as lead compounds for drug development. Here, we used a direct toxin pull-down assay with immobilised KcsA potassium channel to isolate a novel KcsA-binding toxin (called Tx7335) from eastern green mamba snake (Dendroaspis angusticeps) venom. Sequencing of the toxin by Edman degradation and mass spectrometry revealed a 63 amino acid residue peptide with 4 disulphide bonds that belongs to the three-finger toxin family, but with a unique modification of its disulphide-bridge scaffold. The toxin induces a dose-dependent increase in both open probabilities and mean open times on KcsA in artificial bilayers. Thus, it unexpectedly behaves as a channel activator rather than an inhibitor. A charybdotoxin-sensitive mutant of KcsA exhibits similar susceptibility to Tx7335 as wild-type, indicating that the binding site for Tx7335 is distinct from that of canonical pore-blocker toxins. Based on the extracellular location of the toxin binding site (far away from the intracellular pH gate), we propose that Tx7335 increases potassium flow through KcsA by allosterically reducing inactivation of the channel.

In vivo imaging provides unprecedented access to the dynamic behavior of cellular and subcellular structures in their natural context. Performing such imaging experiments in higher vertebrates such as mammals generally requires surgical access to the system under study. The optical accessibility of embryonic and larval zebrafish allows such invasive procedures to be circumvented and permits imaging in the intact organism. Indeed the zebrafish is now a well-established model to visualize dynamic cellular behaviors using in vivo microscopy in a wide range of developmental contexts from proliferation to migration and differentiation. A more recent development is the increasing use of zebrafish to study subcellular events including mitochondrial trafficking and centrosome dynamics. The relative ease with which these subcellular structures can be genetically labeled by fluorescent proteins and the use of light microscopy techniques to image them is transforming the zebrafish into an in vivo model of cell biology. Here we describe methods to generate genetic constructs that fluorescently label organelles, highlighting mitochondria and centrosomes as specific examples. We use the bipartite Gal4-UAS system in multiple configurations to restrict expression to specific cell-types and provide protocols to generate transiently expressing and stable transgenic fish. Finally, we provide guidelines for choosing light microscopy methods that are most suitable for imaging subcellular dynamics.

Spermatogonial stem and progenitor cells (SSCs) generate adult male gametes. During in vitro expansion, these unipotent murine cells spontaneously convert to multipotent adult spermatogonial-derived stem cells (MASCs). Here we investigate this conversion process through integrative transcriptomic and epigenomic analyses. We find in SSCs that promoters essential to maintenance and differentiation of embryonic stem cells (ESCs) are enriched with histone H3-lysine4 and -lysine 27 trimethylations. These bivalent modifications are maintained at most somatic promoters after conversion, bestowing MASCs an ESC-like promoter chromatin. At enhancers, the core pluripotency circuitry is activated partially in SSCs and completely in MASCs, concomitant with loss of germ cell-specific gene expression and initiation of embryonic-like programs. Furthermore, SSCs in vitro maintain the epigenomic characteristics of germ cells in vivo. Our observations suggest that SSCs encode innate plasticity through the epigenome and that both conversion of promoter chromatin states and activation of cell type-specific enhancers are prominent features of reprogramming.

N-methyl-D-aspartate receptors (NMDARs) are gluta-mate-gated, calcium-permeable ion channels that mediate synaptic transmission and underpin learning and memory. NMDAR dysfunction is directly implicated in diseases ranging from seizure to ischemia. Despite its fundamental importance, little is known about how the NMDAR transitions between inactive and active states and how small molecules inhibit or activate ion channel gating. Here, we report electron cryo-microscopy structures of the GluN1-GluN2B NMDA receptor in an ensemble of competitive antagonist-bound states, an agonist-bound form, and a state bound with agonists and the allosteric inhibitor Ro25-6981. Together with double electron-electron resonance experiments, we show how competitive antagonists rupture the ligand binding domain (LBD) gating "ring,'' how agonists retain the ring in a dimer-of- dimers configuration, and how allosteric inhibitors, acting within the amino terminal domain, further stabilize the LBD layer. These studies illuminate how the LBD gating ring is fundamental to signal transduction and gating in NMDARs.

Cell motion inside dense tissues governs many biological processes, including embryonic development and cancer metastasis, and recent experiments suggest that these tissues exhibit collective glassy behavior. To make quantitative predictions about glass transitions in tissues, we study a self-propelled Voronoi model that simultaneously captures polarized cell motility and multibody cell-cell interactions in a confluent tissue, where there are no gaps between cells. We demonstrate that the model exhibits a jamming transition from a solidlike state to a fluidlike state that is controlled by three parameters: the single-cell motile speed, the persistence time of single-cell tracks, and a target shape index that characterizes the competition between cell-cell adhesion and cortical tension. In contrast to traditional particulate glasses, we are able to identify an experimentally accessible structural order parameter that specifies the entire jamming surface as a function of model parameters. We demonstrate that a continuum soft glassy rheology model precisely captures this transition in the limit of small persistence times and explain how it fails in the limit of large persistence times. These results provide a framework for understanding the collective solid-to-liquid transitions that have been observed in embryonic development and cancer progression, which may be associated with epithelial-to-mesenchymal transition in these tissues.