Publications search

Found 37769 matches. Displaying 4591-4600
Yan J, Anderson C, Viets K, Tran S, Goldberg G, Small S, Johnston RJ
Show All Authors

Regulatory logic driving stable levels of defective proventriculus expression during terminal photoreceptor specification in flies

DEVELOPMENT 2017 MAR; 144(5):844-855
How differential levels of gene expression are controlled in post-mitotic neurons is poorly understood. In the Drosophila retina, expression of the transcription factor Defective Proventriculus (Dve) at distinct cell type-specific levels is required for terminal differentiation of color- and motion-detecting photoreceptors. Here, we find that the activities of two cis-regulatory enhancers are coordinated to drive dve expression in the fly eye. Three transcription factors act on these enhancers to determine cell-type specificity. Negative autoregulation by Dve maintains expression from each enhancer at distinct homeostatic levels. One enhancer acts as an inducible backup ('dark' shadow enhancer) that is normally repressed but becomes active in the absence of the other enhancer. Thus, two enhancers integrate combinatorial transcription factor input, feedback and redundancy to generate cell type-specific levels of dve expression and stable photoreceptor fate. This regulatory logic may represent a general paradigm for how precise levels of gene expression are established and maintained in post-mitotic neurons.
Ungar B
Show All Authors

Patch testing of food allergens promotes Th17 and Th2 responses with

EXPERIMENTAL DERMATOLOGY 2017 MAR; 26(3):272-275
Kushnir VA, Darmon SK, Shapiro AJ, Albertini DF, Barad DH, Gleicher N
Show All Authors

Utilization of third-party in vitro fertilization in the United States

AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY 2017 MAR; 216(3):? Article 266.e1-e10
BACKGROUND: The use of in vitro fertilization that includes third-party in vitro fertilization is increasing. However, the relative contribution of third-party in vitro fertilization that includes the use of donor oocytes, sperm, or embryo and a gestational carrier to the birth cohort after in vitro fertilization is unknown. OBJECTIVE: The purpose of this study was to examine the contribution of third-party in vitro fertilization to the in vitro fertilization birth cohort over the past decade. STUDY DESIGN: This retrospective analysis investigated 1,349,874 in vitro fertilization cycles that resulted in 421,525 live births and 549,367 liveborn infants in the United States from 2004-2013. Cycles were self-reported by fertility centers to a national registry: Society for Assisted Reproductive Technologies Clinic Outcome Reporting System. RESULTS: Third-party in vitro fertilization accounted for 217,030 (16.1%) of all in vitro fertilization cycles, 86,063 (20.4%) of all live births, and 115,024 (20.9%) of all liveborn infants. Overall, 39.7% of third-party in vitro fertilization cycles resulted in a live birth, compared with 29.6% of autologous in vitro fertilization cycles. Use of third-party in vitro fertilization increased with maternal age and accounted for 42.2% of all in vitro fertilization cycles and 75.3% of all liveborn infants among women > 40 years old. Oocyte donation was the most common third-party in vitro fertilization technique, followed by sperm donation. Over the study period, annual cycle volume and live birth rates gradually increased for both autologous in vitro fertilization and third-party in vitro fertilization (P <. 0001 for all). Live birth rates were the highest when multiple third-party in vitro fertilization modalities were used, followed by oocyte donation. CONCLUSION: Third-party in vitro fertilization use and efficacy have increased over the past decade, now comprising > 20% of the total in vitro fertilization birth cohort. In women who are > 40 years old, third-party in vitro fertilization has become the dominant treatment.
Andrade EC, Musante V, Horiuchi A, Matsuzaki H, Brody AH, Wu T, Greengard P, Taylor JR, Nairn AC
Show All Authors

ARPP-16 Is a Striatal-Enriched Inhibitor of Protein Phosphatase 2A Regulated by Microtubule-Associated Serine/Threonine Kinase 3 (Mast 3 Kinase)

JOURNAL OF NEUROSCIENCE 2017 MAR 8; 37(10):2709-2722
ARPP-16 (cAMP-regulated phospho-protein of molecular weight 16 kDa) is one of several small acid-soluble proteins highly expressed in medium spiny neurons of striatum that are phosphorylated in response to dopamine acting via D1 receptor/protein kinase A (PKA) signaling. We show here that ARPP-16 is also phosphorylated in vitro and in vivo by microtubule-associated serine/threonine kinase 3 (MAST3 kinase), an enzyme of previously unknown function that is enriched in striatum. We find that ARPP-16 interacts directly with the scaffolding A subunit of the serine/threonine protein phosphatase, PP2A, and that phosphorylation of ARPP-16 at Ser46 by MAST3 kinase converts the protein into a selective inhibitor of B55 alpha-and B56 delta-containing heterotrimeric forms of PP2A. Ser46 of ARPP-16 is phosphorylated to a high basal stoichiometry in striatum, suggestive of basal inhibition of PP2A in striatal neurons. In support of this hypothesis, conditional knock-out of ARPP-16 in CaMKII alpha :: cre/floxed ARPP-16/19 mice results in dephosphorylation of a subset of PP2A substrates including phospho-Thr75-DARPP-32, phospho-T308-Akt, and phospho-T202/Y204-ERK. Conditional knock-out of ARPP-16/19 is associated with increased motivation measured on a progressive ratio schedule of food reinforcement, yet an attenuated locomotor response to acute cocaine. Our previous studies have shown that ARPP-16 is phosphorylated at Ser88 by PKA. Activation of PKA in striatal slices leads to phosphorylation of Ser88, and this is accompanied by marked dephosphorylation of Ser46. Together, these studies suggest that phospho-Ser46-ARPP-16 acts to basally control PP2A in striatal medium spiny neurons but that dopamine acting via PKA inactivates ARPP-16 leading to selective potentiation of PP2A signaling.
Bournazos S, Ravetch JV
Show All Authors

Attenuated Vaccines for Augmented Immunity

CELL HOST & MICROBE 2017 MAR 8; 21(3):314-315
Live attenuated vaccines are more immunogenic and have the capacity to elicit long-lasting immune responses. In two recent studies, Wang et al. (2017) and Si et al. (2016) describe strategies for the generation of live attenuated influenza viruses, which elicited robust humoral, mucosal, and cellular immunity against diverse virus strains.
Simunovic M, Brivanlou AH
Show All Authors

Embryoids, organoids and gastruloids: new approaches to understanding embryogenesis

DEVELOPMENT 2017 MAR 15; 144(6):976-985
Cells have an intrinsic ability to self-assemble and self-organize into complex and functional tissues and organs. By taking advantage of this ability, embryoids, organoids and gastruloids have recently been generated in vitro, providing a unique opportunity to explore complex embryological events in a detailed and highly quantitative manner. Here, we examine how such approaches are being used to answer fundamental questions in embryology, such as how cells self-organize and assemble, how the embryo breaks symmetry, and what controls timing and size in development. We also highlight how further improvements to these exciting technologies, based on the development of quantitative platforms to precisely follow and measure subcellular and molecular events, are paving the way for a more complete understanding of the complex events that help build the human embryo.
Johnson ZL, Chen J
Show All Authors

Structural Basis of Substrate Recognition by the Multidrug Resistance Protein MRP1

CELL 2017 MAR 9; 168(6):1075-1085.e9
The multidrug resistance protein MRP1 is an ATP-binding cassette (ABC) transporter that confers resistance to many anticancer drugs and plays a role in the disposition and efficacy of several opiates, antidepressants, statins, and antibiotics. In addition, MRP1 regulates redox homeostasis, inflammation, and hormone secretion. Using electron cryomicroscopy, we determined the molecular structures of bovine MRP1 in two conformations: an apo form at 3.5 angstrom without any added substrate and a complex form at 3.3 angstrom with one of its physiological substrates, leukotriene C-4. These structures show that by forming a single bipartite binding site, MRP1 can recognize a spectrum of substrates with different chemical structures. We also observed large conformational changes induced by leukotriene C-4, explaining how substrate binding primes the transporter for ATP hydrolysis. Structural comparison of MRP1 and P-glycoprotein advances our understanding of the common and unique properties of these two important molecules in multidrug resistance to chemotherapy.
Sagner M, McNeil A, Puska P, Auffray C, Price ND, Hood L, Lavie CJ, Han ZG, Chen Z, Brahmachari SK, McEuien BS, Soares MB, Balling R, Epel E, Arena R
Show All Authors

The P4 Health Spectrum - A Predictive, Preventive, Personalized and Participatory Continuum for Promoting Healthspan

PROGRESS IN CARDIOVASCULAR DISEASES 2017 MAR-APR; 59(5):506-521
Chronic diseases (i.e., noncommunicable diseases), mainly cardiovascular disease, cancer, respiratory diseases and type-2-diabetes, are now the leading cause of death, disability and diminished quality of life on the planet. Moreover, these diseases are also a major financial burden worldwide, significantly impacting the economy of many countries. Healthcare systems and medicine have progressively improved upon the ability to address infectious diseases arid react to adverse health events through both surgical-interventions and pharmacology; we have become efficient in delivering reactive care (i.e., initiating interventions once an individual is on the verge of or has actually suffered a negative health event). However, with slowly progressing and often 'silent' chronic diseases now being the main cause of illness, healthcare and medicine must evolve into a proactive system, moving away from a merely reactive approach to care. Minimal interactions among the specialists and limited information to the general practitioner and to the individual receiving care lead to a fragmented health approach, non-concerted prescriptions, a cattered follow-up and a suboptimal cost-effectiveness ratio. A new approach in medicine that is predictive, preventive, personalized and participatory, which we label here as "P4" holds great promise to reduce the burden of chronic diseases by harnessing technology and an increasingly better understanding of environment-biology interactions, evidence-based interventions and the underlying mechanisms of chronic diseases. In this concept paper, we propose a 'P4 Health Continuum' model as a framework to promote and facilitate multi-stakeholder collaboration with an orchestrated common language and an integrated care model to increase the healthspan. (C) 2016 Elsevier Inc. All rights reserved.
Ungar B, Garcet S, Gonzalez J, Dhingra N, da Rosa JC, Shemer A, Krueger JG, Suarez-Farinas M, Guttman-Yassky E
Show All Authors

An Integrated Model of Atopic Dermatitis Biomarkers Highlights the Systemic Nature of the Disease

JOURNAL OF INVESTIGATIVE DERMATOLOGY 2017 MAR; 137(3):603-613
Current atopic dermatitis (AD) models link epidermal abnormalities in lesional skin to cytokine activation. However, there is evolving evidence of systemic immune activation and detectable abnormalities in nonlesional skin. Because some of the best single correlations with severity (Scoring of AD, or SCORAD) are detected not only in lesional but also nonlesional skin and blood, more complex biomarker models of AD are needed. We thus performed extensive biomarker measures in these compartments using univariate and multivariate approaches to correlate disease biomarkers with SCORAD and with a combined hyperplasia score [ thickness and keratin 16 (K16) mRNA] at baseline and after cyclosporine A treatment in 25 moderate to severe AD patients. Increases in serum cytokines and chemokines (IL-13, IL-22, CCL17) were found in AD versus healthy individuals and were reduced with treatment. SCORAD correlated with immune (IL-13, IL-22) and epidermal (thickness, K16) measures in lesional and, even more strongly, in nonlesional AD. Serum cytokines also had higher correlations with nonlesional markers at baseline and with treatment. Multivariate U statistics improved baseline and treatment-response SCORAD correlations. Nonlesional models showed the strongest correlations, with further improvement upon integration of serum markers. Even better correlations were obtained between biomarkers and the hyperplasia score. Larger cohorts are needed to confirm these preliminary data.
The necessity of identifying novel methods to combat infections caused by antibiotic resistant bacteria is increasing each year. Recent advancements in the development of peptidoglycan hydrolases (e.g. lysins) from bacterial viruses (bacteriophages) have revealed the efficiency of this class of enzymes in treating serious bacterial infections. Though promising results have been obtained regarding the lethal action of lysin on bacterial pathogens both in vitro and in vivo, an often-overlooked factor in these studies is precisely identifying their peptidoglycan cleavage site. This knowledge would be useful for following the activity of the enzyme during development, without the need for whole-organism lytic assays. However, more importantly, it would enable the selection of lysins with different cleavage activities that would act synergistically for enhanced efficacy. Here, we have developed two new methods to accurately identify the cleavage site of lysins using liquid chromatography mass spectrometry (LC-MS) on peptidoglycan-like fluorophore-quencher modified synthetic peptides, as well as determining the enzymatic action and kinetics of the enzymes on modified peptides in a Forster resonance energy transfer (FRET) assay. These methods should facilitate progress within the lysin field, accelerating the development of therapeutic lysins to combat antibiotic resistant bacterial infections.