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Found 37684 matches. Displaying 7081-7090
Liesch J, Bellani LL, Vosshall LB
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Functional and Genetic Characterization of Neuropeptide Y-Like Receptors in Aedes aegypti

PLOS NEGLECTED TROPICAL DISEASES 2013 OCT; 7(10):? Article e2486
Background: Female Aedes aegypti mosquitoes are the principal vector for dengue fever, causing 50-100 million infections per year, transmitted between human and mosquito by blood feeding. Ae. aegypti host-seeking behavior is known to be inhibited for three days following a blood meal by a hemolymph-borne humoral factor. Head Peptide-I is a candidate peptide mediating this suppression, but the mechanism by which this peptide alters mosquito behavior and the receptor through which it signals are unknown. Methodology/Principal Findings: Head Peptide-I shows sequence similarity to short Neuropeptide-F peptides (sNPFs) that have been implicated in feeding behaviors and are known to signal through Neuropeptide Y (NPY)-Like Receptors (NPYLRs). We identified eight NPYLRs in the Ae. aegypti genome and screened each in a cell-based calcium imaging assay for sensitivity against a panel of peptides. Four of the Ae. aegypti NPYLRs responded to one or more peptide ligands, but only NYPLR1 responded to Head Peptide-I as well as sNPFs. Two NPYLR1 homologues identified in the genome of the Lyme disease vector, Ixodes scapularis, were also sensitive to Head Peptide-I. Injection of synthetic Head Peptide-I and sNPF-3 inhibited host-seeking behavior in non-blood-fed female mosquitoes, whereas control injections of buffer or inactive Head Peptide-I [Cys10] had no effect. To ask if NPYLR1 is necessary for blood-feeding-induced host-seeking inhibition, we used zinc-finger nucleases to generate five independent npylr1 null mutant strains and tested them for behavioral abnormalities. npylr1 mutants displayed normal behavior in locomotion, egg laying, sugar feeding, blood feeding, host seeking, and inhibition of host seeking after a blood meal. Conclusions: In this work we deorphanized four Ae. aegypti NPYLRs and identified NPYLR1 as a candidate sNPF receptor that is also sensitive to Head Peptide-I. Yet npylr1 alone is not required for host-seeking inhibition and we conclude that other receptors, additional peptides, or both, regulate this important behavior.
Fins JJ
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Disorders of Consciousness and Disordered Care: Families, Caregivers, and Narratives of Necessity

ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION 2013 OCT; 94(10):1934-1939
By their nature, care decisions for patients with severe disorders of consciousness must involve surrogates. Patients, so impaired, have lost their decision-making capacity and the ability to direct their own care. Surrogates-family members, friends, or other intimates-must step in and make decisions about ongoing care or its withdrawal. This article shares the narrative experiences of these surrogate decision makers as they encounter the American health care system and accompany patients from injury through rehabilitation. Through their perspectives, the article considers challenges to ongoing care and rehabilitation that are a function of a prevailing medical infrastructure and reimbursement framework better suited to patients with acute care needs. Specific attention is paid to the ethical challenges posed by reimbursement strategies such as "medical necessity" as well as those proposed for the Affordable Care Act. The argument concludes that when it comes to care for a disorder related to consciousness, its provision is not discretionary, and its receipt is not an entitlement but a civil right. (c) 2013 by the American Congress of Rehabilitation Medicine
Tian Y, Chang JC, Fan EY, Flajolet M, Greengard P
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Adaptor complex AP2/PICALM, through interaction with LC3, targets Alzheimer's APP-CTF for terminal degradation via autophagy

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2013 OCT 15; 110(42):17071-17076
The hallmarks of Alzheimer's disease (AD) are the aggregates of amyloid-beta (A beta) peptides and tau protein. Autophagy is a major cellular pathway leading to the removal of aggregated proteins. We have reported recently that autophagy was responsible for amyloid precursor protein cleaved C-terminal fragment (APP-CTF) degradation and amyloid beta clearance in an Atg5-dependent manner. Here we aimed to elucidate the molecular mechanism by which autophagy mediates the degradation of APP-CTF and the clearance of amyloid beta. Through affinity purification followed by mass spectrum analysis, we identified adaptor protein (AP) 2 together with phosphatidylinositol clathrin assembly lymphoid-myeloid leukemia (PICALM) as binding proteins of microtubule-associated protein 1 light chain 3 (LC3). Further analysis showed that AP2 regulated the cellular levels of APP-CTF. Knockdown of AP2 reduced autophagy-mediated APP-CTF degradation. Immunoprecipitation and live imaging analysis demonstrated that AP2 and PICALM cross-link LC3 with APP-CTF. These data suggest that the AP-2/PICALM complex functions as an autophagic cargo receptor for the recognition and shipment of APP-CTF from the endocytic pathway to the LC3-marked autophagic degradation pathway. This molecular mechanism linking AP2/PICALM and AD is consistent with genetic evidence indicating a role for PICALM as a risk factor for AD.
Rodriguez JM, Wolfrum S, Robblee M, Chen KY, Gilbert ZN, Choi JH, Teupser D, Breslow JL
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Altered Expression of Raet1e, a Major Histocompatibility Complex Class 1-Like Molecule, Underlies the Atherosclerosis Modifier Locus Ath11 10b

CIRCULATION RESEARCH 2013 OCT 12; 113(9):1054-1064
Rationale: Quantitative trait locus mapping of an intercross between C57.Apoe(-/-) and FVB.Apoe(-/-) mice revealed an atherosclerosis locus controlling aortic root lesion area on proximal chromosome 10, Ath11. In a previous work, subcongenic analysis showed Ath11 to be complex with proximal (10a) and distal (10b) regions. Objective: To identify the causative genetic variation underlying the atherosclerosis modifier locus Ath11 10b. Methods and Results: We now report subcongenic J, which narrows the 10b region to 5 genes, Myb, Hbs1L, Aldh8a1, Sgk1, and Raet1e. Sequence analysis of these genes revealed no amino acid coding differences between the parental strains. However, comparing aortic expression of these genes between F1.Apoe(-/-) Chr10SubJ((B/F)) and F1.Apoe(-/-) Chr10SubJ((F/F)) uncovered a consistent difference only for Raet1e, with decreased, virtually background, expression associated with increased atherosclerosis in the latter. The key role of Raet1e was confirmed by showing that transgene-induced aortic overexpression of Raet1e in F1.Apoe(-/-) Chr10SubJ((F/F)) mice decreased atherosclerosis. Promoter reporter constructs comparing C57 and FVB sequences identified an FVB mutation in the core of the major aortic transcription start site abrogating activity. Conclusions: This nonbiased approach has revealed Raet1e, a major histocompatibility complex class 1-like molecule expressed in lesional aortic endothelial cells and macrophage-rich regions, as a novel atherosclerosis gene and represents one of the few successes of the quantitative trait locus strategy in complex diseases.
Dhingra N, Gulati N, Guttman-Yassky E
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Mechanisms of Contact Sensitization Offer Insights into the Role of Barrier Defects vs. Intrinsic Immune Abnormalities as Drivers of Atopic Dermatitis

JOURNAL OF INVESTIGATIVE DERMATOLOGY 2013 OCT; 133(10):2311-2314
Atopic dermatitis (AD) is a common inflammatory skin disease characterized by wet, oozing, erythematous, pruritic lesions in the acute stage and xerotic, lichenified plaques in the chronic stage. It frequently coexists with asthma and allergic rhinitis, sharing some mechanistic features with these diseases as part of the "atopic march." Controversy exists as to whether immune abnormalities, epidermal barrier defects, or both are the primary factors responsible for disease pathogenesis. In AD patients, there is often a coexisting irritant contact dermatitis (ICD) or allergic contact dermatitis (ACD) that is sometimes clinically difficult to distinguish from AD. ACD shares molecular mechanisms with AD, including increased cellular infiltrates and cytokine activation (Gittler et aL, 2013). In this issue, Newell et aL (2013) used an experimental contact sensitization model with dinitrochlorobenzene (DNCB) to gain insight into the unique immune phenotype of AD patients.
Banta AB, Chumanov RS, Yuan AH, Lin HL, Campbell EA, Burgess RR, Gourse RL
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Key features of sigma(S) required for specific recognition by Crl, a transcription factor promoting assembly of RNA polymerase holoenzyme

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2013 OCT 1; 110(40):15955-15960
Bacteria use multiple sigma factors to coordinate gene expression in response to environmental perturbations. In Escherichia coli and other.-proteobacteria, the transcription factor Crl stimulates sigma(s) -dependent transcription during times of cellular stress by promoting the association of sigma(5) with core RNA polymerase. The molecular basis for specific recognition of sigma(5) by Crl, rather than the homologous and more abundant primary sigma factor sigma(70), is unknown. Here we use bacterial two-hybrid analysis in vivo and p-benzoylphenylalanine cross-linking in vitro to define the features in s S responsible for specific recognition by Crl. We identify residues in s S conserved domain 2 (sigma(S) (2)) that are necessary and sufficient to allow recognition of sigma(70) conserved domain 2 by Crl, one near the promoter-melting region and the other at the position where a large nonconserved region interrupts the sequence of sigma(70.) We then use luminescence resonance energy transfer to demonstrate directly that Crl promotes holoenzyme assembly using these specificity determinants on sigma(5). Our results explain how Crl distinguishes between sigma factors that are largely homologous and activates discrete sets of promoters even though it does not bind to promoter DNA.
Stadler SC, Vincent CT, Fedorov VD, Patsialou A, Cherrington BD, Wakshlag JJ, Mohanan S, Zee BM, Zhang XS, Garcia BA, Condeelis JS, Brown AMC, Coonrod SA, Allis CD
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Dysregulation of PAD4-mediated citrullination of nuclear GSK3 beta activates TGF-beta signaling and induces epithelial-to-mesenchymal transition in breast cancer cells (vol 110, pg 11851, 2013)

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2013 OCT 1; 110(40):16283-16283
Eder M, Carter-Edwards L, Hurd TC, Rumala BB, Wallerstein N
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A Logic Model for Community Engagement Within the Clinical and Translational Science Awards Consortium: Can We Measure What We Model?

ACADEMIC MEDICINE 2013 OCT; 88(10):1430-1436
The Clinical and Translational Science Award (CTSA) initiative calls on academic health centers to engage communities around a clinical research relationship measured ultimately in terms of public health. Among a few initiatives involving university accountability for advancing public interests, a small CTSA workgroup devised a community engagement (CE) logic model that organizes common activities within a university-community infrastructure to facilitate CE in research. Whereas the model focuses on the range of institutional CE inputs, it purposefully does not include an approach for assessing how CE influences research implementation and outcomes. Rather, with communities and individuals beginning to transition into new research roles, this article emphasizes studying CE through specific relationship types and assessing how expanded research teams contribute to the full spectrum of translational science. The authors propose a typology consisting of three relationship typesengagement, collaboration, and shared leadershipto provide a foundation for investigating community-academic contributions to the new CTSA research paradigm. The typology shifts attention from specific community-academic activities and, instead, encourages analyses focused on measuring the strength of relationships through variables like synergy and trust. The collaborative study of CE relationships will inform an understanding of CTSA infrastructure development in support of translational research and its goal, which is expressed in the logic model: better science, better answers, better population health.
Cabantous S, Nguyen HB, Pedelacq JD, Koraichi F, Chaudhary A, Ganguly K, Lockard MA, Favre G, Terwilliger TC, Waldo GS
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A New Protein-Protein Interaction Sensor Based on Tripartite Split-GFP Association

SCIENTIFIC REPORTS 2013 OCT 4; 3(?):? Article 2854
Monitoring protein-protein interactions in living cells is key to unraveling their roles in numerous cellular processes and various diseases. Previously described split-GFP based sensors suffer from poor folding and/or self-assembly background fluorescence. Here, we have engineered a micro-tagging system to monitor protein-protein interactions in vivo and in vitro. The assay is based on tripartite association between two twenty amino-acids long GFP tags, GFP10 and GFP11, fused to interacting protein partners, and the complementary GFP1-9 detector. When proteins interact, GFP10 and GFP11 self-associate with GFP1-9 to reconstitute a functional GFP. Using coiled-coils and FRB/FKBP12 model systems we characterize the sensor in vitro and in Escherichia coli. We extend the studies to mammalian cells and examine the FK-506 inhibition of the rapamycin-induced association of FRB/FKBP12. The small size of these tags and their minimal effect on fusion protein behavior and solubility should enable new experiments for monitoring protein-protein association by fluorescence.
Gorlich A, Antolin-Fontes B, Ables JL, Frahm S, Slimak MA, Dougherty JD, Ibanez-Tallon I
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Reexposure to nicotine during withdrawal increases the pacemaking activity of cholinergic habenular neurons

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2013 OCT 15; 110(42):17077-17082
The discovery of genetic variants in the cholinergic receptor nicotinic CHRNA5-CHRNA3-CHRNB4 gene cluster associated with heavy smoking and higher relapse risk has led to the identification of the midbrain habenula-interpeduncular axis as a critical relay circuit in the control of nicotine dependence. Although clear roles for alpha 3, beta 4, and alpha 5 receptors in nicotine aversion and withdrawal have been established, the cellular and molecular mechanisms that participate in signaling nicotine use and contribute to relapse have not been identified. Here, using translating ribosome affinity purification (TRAP) profiling, electrophysiology, and behavior, we demonstrate that cholinergic neurons, but not peptidergic neurons, of the medial habenula (MHb) display spontaneous tonic firing of 2-10 Hz generated by hyperpolarization-activated cyclic nucleotide-gated (HCN) pacemaker channels and that infusion of the HCN pacemaker antagonist ZD7288 in the habenula precipitates somatic and affective signs of withdrawal. Further, we show that a strong, alpha 3 beta 4-dependent increase in firing frequency is observed in these pacemaker neurons upon acute exposure to nicotine. No change in the basal or nicotine-induced firing was observed in cholinergic MHb neurons from mice chronically treated with nicotine. We observe, however, that, during withdrawal, reexposure to nicotine doubles the frequency of pacemaking activity in these neurons. These findings demonstrate that the pacemaking mechanism of cholinergic MHb neurons controls withdrawal, suggesting that the heightened nicotine sensitivity of these neurons during withdrawal may contribute to smoking relapse.