Publications search

Found 37769 matches. Displaying 4571-4580
Kost RG, Leinberger-Jabari A, Evering TH, Holt PR, Neville-Williams M, Vasquez KS, Coller BS, Tobin JN
Show All Authors

Helping Basic Scientists Engage With Community Partners to Enrich and Accelerate Translational Research

ACADEMIC MEDICINE 2017 MAR; 92(3):374-379
Problem Engaging basic scientists in community-based translational research is challenging but has great potential for improving health. Approach In 2009, The Rockefeller University Center for Clinical and Translational Science partnered with Clinical Directors Network, a practice-based research network (PBRN), to create a community-engaged research navigation (CEnR-Nav) program to foster research pairing basic science and community-driven scientific aims. The program is led by an academic navigator and a PBRN navigator. Through meetings and joint activities, the program facilitates basic science-community partnerships and the development and conduct of joint research protocols. Outcomes From 2009-2014, 39 investigators pursued 44 preliminary projects through the CEnR-Nav program; 25 of those became 23 approved protocols and 2 substudies. They involved clinical scholar trainees, early-career physician-scientists, faculty, students, postdoctoral fellows, and others. Nineteen (of 25; 76%) identified community partners, of which 9 (47%) named them as coinvestigators. Nine (of 25; 36%) included T3-T4 translational aims. Seven (of 25; 28%) secured external funding, 11 (of 25; 44%) disseminated results through presentations or publications, and 5 (71%) of 7 projects publishing results included a community partner as a coauthor. Of projects with long-term navigator participation, 9 (of 19; 47%) incorporated T3-T4 aims and 7 (of 19; 37%) secured external funding. Next Steps The CEnR-Nav program provides a model for successfully engaging basic scientists with communities to advance and accelerate translational science. This model's durability and generalizability have not been determined, but it achieves valuable short-term goals and facilitates scientifically meaningful community-academic partnerships.
Yamaji M, Jishage M, Meyer C, Suryawanshi H, Evan, Yamaji M, Garzia A, Morozov P, Manickavel S, Mcfarland HL, Roeder RG, Hafner M, Tuschl T
Show All Authors

DND1 maintains germline stem cells via recruitment of the CCR4-NOT complex to target mRNAs

NATURE 2017 MAR 23; 543(7646):568-572
The vertebrate-conserved RNA-binding protein DND1 is required for the survival of primordial germ cells (PGCs), as well as the suppression of germ cell tumours in mice(1-5). Here we show that in mice DND1 binds a UU(A/U) trinucleotide motif predominantly in the 3' untranslated regions of mRNA, and destabilizes target mRNAs through direct recruitment of the CCR4-NOT deadenylase complex. Transcriptomic analysis reveals that the extent of suppression is dependent on the number of DND1-binding sites. This DND1-dependent mRNA destabilization is required for the survival of mouse PGCs and spermatogonial stem cells by suppressing apoptosis. The spectrum of target RNAs includes positive regulators of apoptosis and inflammation, and modulators of signalling pathways that regulate stem-cell pluripotency, including the TGFa superfamily, all of which are aberrantly elevated in DND1-deficient PGCs. We propose that the induction of the post-transcriptional suppressor DND1 synergizes with concurrent transcriptional changes to ensure precise developmental transitions during cellular differentiation and maintenance of the germ line.
Shima T, Matsui T, Jesmin S, Okamoto M, Soya M, Inoue K, Liu YF, Torres-Aleman I, McEwen BS, Soya H
Show All Authors

Moderate exercise ameliorates dysregulated hippocampal glycometabolism and memory function in a rat model of type 2 diabetes

DIABETOLOGIA 2017 MAR; 60(3):597-606
Aims/hypothesis Type 2 diabetes is likely to be an independent risk factor for hippocampal-based memory dysfunction, although this complication has yet to be investigated in detail. As dysregulated glycometabolism in peripheral tissues is a key symptom of type 2 diabetes, it is hypothesised that diabetes-mediated memory dysfunction is also caused by hippocampal glycometabolic dysfunction. If so, such dysfunction should also be ameliorated with moderate exercise by normalising hippocampal glycometabolism, since 4 weeks of moderate exercise enhances memory function and local hippocampal glycogen levels in normal animals. Methods The hippocampal glycometabolism in OLETF rats (model of human type 2 diabetes) was assessed and, subsequently, the effects of exercise on memory function and hippocampal glycometabolism were investigated. Results OLETF rats, which have memory dysfunction, exhibited higher levels of glycogen in the hippocampus than did control rats, and breakdown of hippocampal glycogen with a single bout of exercise remained unimpaired. However, OLETF rats expressed lower levels of hippocampal monocarboxylate transporter 2 (MCT2, a transporter for lactate to neurons). Four weeks of moderate exercise improved spatial memory accompanied by further increase in hippocampal glycogen levels and restoration of MCT2 expression independent of neurotrophic factor and clinical symptoms in OLETF rats. Conclusion/interprelation Our findings are the first to describe detailed profiles of glycometabolism in the type 2 diabetic hippocampus and to show that 4 weeks of moderate exercise improves memory dysfunction in type 2 diabetes via amelioration of dysregulated hippocampal glycometabolism. Dysregulated hippocampal lactate-transport-related glycometabolism is a possible aetiology of type-2-diabetes-mediated memory dysfunction.
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.
Most methicillin-resistant Staphylococcus aureus (MRSA) strains are resistant to beta-lactam antibiotics due to the presence of the mecA gene, encoding an extra penicillin-binding protein (PBP2A) that has low affinity for virtually all beta-lactam antibiotics. Recently, a new resistance determinant-the mecC gene-was identified in S. aureus isolates recovered from humans and dairy cattle. Although having typically low MICs to beta-lactam antibiotics, MRSA strains with the mecC determinant are also capable of expressing high levels of oxacillin resistance when in an optimal genetic background. In order to test the impact of extensive beta-lactam selection on the emergence of mecC-carrying strains with high levels of antibiotic resistance, we exposed the prototype mecC-carrying MRSA strain, LGA251, to increasing concentrations of oxacillin. LGA251 was able to rapidly adapt to high concentrations of oxacillin in growth medium. In such laboratory mutants with increased levels of oxacillin resistance, we identified mutations in genes with no relationship to the mecC regulatory system, indicating that the genetic background plays an important role in the establishment of the levels of oxacillin resistance. Our data also indicate that the stringent stress response plays a critical role in the beta-lactam antibiotic resistance phenotype of MRSA strains carrying the mecC determinant.
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.
Bieniasz P
Show All Authors

Repurposing a Bacterial Immune System to Discover Antiviral Targets

NEW ENGLAND JOURNAL OF MEDICINE 2017 MAR 30; 376(13):1290-1291
The effect of new, easy-to-use tools for editing cellular genomes in medicine and biomedical science is difficult to overstate. The new method uses programmable DNA-cutting machinery from a bacterial immune system (CRISPR [clustered regularly interspaced short palindromic repeats]–Cas9), which can be repurposed for use in nearly any type of cell. With the use of CRISPR guides (i.e., CRISPR RNA that guides Cas9 to a specific location in the human genome), the Cas9 enzyme can be targeted to inactivate or edit specific genes in cultured cells or in laboratory animals. Perhaps one day — if technical and ethical constraints are addressed — this method will be used to treat human disease.
Maciejowski J, de Lange T
Show All Authors

Telomeres in cancer: tumour suppression and genome instability

NATURE REVIEWS MOLECULAR CELL BIOLOGY 2017 MAR; 18(3):175-186
The shortening of human telomeres has two opposing effects during cancer development. On the one hand, telomere shortening can exert a tumour-suppressive effect through the proliferation arrest induced by activating the kinases ATM and ATR at unprotected chromosome ends. On the other hand, loss of telomere protection can lead to telomere crisis, which is a state of extensive genome instability that can promote cancer progression. Recent data, reviewed here, provide new evidence for the telomere tumour suppressor pathway and has revealed that telomere crisis can induce numerous cancer-relevant changes, including chromothripsis, kataegis and tetraploidization.
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.
Tangye SG, Pillay B, Randall KL, Avery DT, Phan TG, Gray P, Ziegler JB, Smart JM, Peake J, Arkwright PD, Hambleton S, Orange J, Goodnow CC, Uzel G, Casanova JL, Reyes SOL, Freeman AF, Su HC, Ma CS
Show All Authors

Dedicator of cytokinesis 8-deficient CD4(+) T cells are biased to a T(H)2 effector fate at the expense of T(H)1 and T(H)17 cells

JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY 2017 MAR; 139(3):933-949
Background: Dedicator of cytokinesis 8 (DOCK8) deficiency is a combined immunodeficiency caused by autosomal recessive loss-of- function mutations in DOCK8. This disorder is characterized by recurrent cutaneous infections, increased serum IgE levels, and severe atopic disease, including food-induced anaphylaxis. However, the contribution of defects in CD4(+) T cells to disease pathogenesis in these patients has not been thoroughly investigated. Objective: We sought to investigate the phenotype and function of DOCK8-deficient CD4(+) T cells to determine (1) intrinsic and extrinsic CD4 1 T-cell defects and (2) how defects account for the clinical features of DOCK8 deficiency. Methods: We performed in-depth analysis of the CD4(+) T-cell compartment of DOCK8-deficient patients. We enumerated subsets of CD4(+) T helper cells and assessed cytokine production and transcription factor expression. Finally, we determined the levels of IgE specific for staple foods and house dust mite allergens in DOCK8-deficient patients and healthy control subjects. Results: DOCK8-deficient memory CD4 1 T cells were biased toward a T(H)2 type, and this was at the expense of T(H)1 and T(H)17 cells. In vitro polarization of DOCK8-deficient naive CD4(+) T cells revealed the TH2 bias and TH17 defect to be T-cell intrinsic. Examination of allergen-specific IgE revealed plasma IgE from DOCK8-deficient patients is directed against staple food antigens but not house dust mites. Conclusion: Investigations into the DOCK8-deficient CD4(+) T cells provided an explanation for some of the clinical features of this disorder: the T(H)2 bias is likely to contribute to atopic disease, whereas defects in T(H)1 and T(H)17 cells compromise antiviral and antifungal immunity, respectively, explaining the infectious susceptibility of DOCK8-deficient patients.