bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brief Report: HIV Antibodies Decline During Antiretroviral Therapy but Remain Correlated With HIV DNA and HIV-Specific T-Cell Responses
Authors: Keating Sheila M. , Jones Richard Brad , Lalama Christina M. , Bosch Ronald J. , McMahon Deborah , Hampton Dylan , Cyktor Joshua , Eron Joseph J. , Mellors John W. , Busch Michael P. , Gandhi Rajesh T. ,   the ACTG 5321 Team
Published: April 2019

Background:
In people with HIV on antiretroviral therapy (ART), the relationship between HIV-specific immune responses and measures of HIV persistence is uncertain.

Methods:
We evaluated 101 individuals on suppressive ART in the AIDS Clinical Trials Group A5321 cohort. Cell-associated (CA) HIV DNA and RNA levels and HIV antibody concentrations and avidity to Env/p24 were measured longitudinally at years 1, 4, and 6–15 after ART initiation. Plasma HIV RNA by single copy assay and T-cell responses (IFN-γ ELISPOT) against multiple HIV antigens were measured at the last time point.

Results:
HIV antibody levels declined significantly with increasing time on ART (19%/year between year 1 and 4). HIV antibody levels correlated with T-cell responses to HIV Pol (r = 0.28, P = 0.014) and to Nef/Tat/Rev (r = 0.34; P = 0.002). HIV antibody and T-cell responses were positively associated with HIV DNA levels; for example, at the last time point (median 7 years on ART), r = 0.35 for antibody levels and HIV DNA (P < 0.001); r = 0.23 for Nef/Tat/Rev-specific T-cell responses and HIV DNA (P = 0.03). Neither antibody nor T-cell responses correlated with cell-associated HIV RNA or plasma RNA by single copy assay.

Conclusions:
In individuals on long-term ART, HIV-specific antibody and T-cell responses correlate with each other and with HIV DNA levels. The positive correlation between HIV immune responses and HIV DNA implies that the immune system is sensing, but not clearing, infected cells, perhaps because of immune dysfunction. Measuring immune responses to HIV antigens may provide insight into the impact of reservoir-reducing strategies.
Interactions of pharmaceutical companies with world countries, cancers and rare diseases from Wikipedia network analysis
Authors: Rollin Guillaume , Lages José , Serebriyskaya Tatiana S. , Shepelyansky Dima L. 
Published: April 2019

AbstractUsing the English Wikipedia network of more than 5 million articles we analyze interactions and interlinks between the 34 largest pharmaceutical companies, 195 world countries, 47 rare renal diseases and 37 types of cancer. The recently developed algorithm using a reduced Google matrix (REGOMAX) allows us to take account both of direct Markov transitions between these articles and also of indirect transitions generated by the pathways between them via the global Wikipedia network. This approach therefore provides a compact description of interactions between these articles that allows us to determine the friendship networks between them, as well as the PageRank sensitivity of countries to pharmaceutical companies and rare renal diseases. We also show that the top pharmaceutical companies in terms of their Wikipedia PageRank are not those with the highest market capitalization.
tRNAscan-SE 2.0: Improved Detection and Functional Classification of Transfer RNA Genes
Authors: Chan Patricia P. , Lin Brian Y. , Mak Allysia J. , Lowe Todd M. 
Published: April 2019

ABSTRACTtRNAscan-SE has been widely used for transfer RNA (tRNA) gene prediction for over twenty years, developed just as the first genomes were decoded. With the massive increase in quantity and phylogenetic diversity of genomes, the accurate detection and functional prediction of tRNAs has become more challenging. Utilizing a vastly larger training set, we created nearly one hundred specialized isotype-and clade-specific models, greatly improving tRNAscan-SE’s ability to identify and classify both typical and atypical tRNAs. We employ a new comparative multi-model strategy where predicted tRNAs are scored against a full set of isotype-specific covariance models, allowing functional prediction based on both the anticodon and the highest-scoring isotype model. Comparative model scoring has also enhanced the program’s ability to detect tRNA-derived SINEs and other likely pseudogenes. For the first time, tRNAscan-SE also includes fast and highly accurate detection of mitochondrial tRNAs using newly developed models. Overall, tRNA detection sensitivity and specificity is improved for all isotypes, particularly those utilizing specialized models for selenocysteine and the three subtypes of tRNA genes encoding a CAU anticodon. These enhancements will provide researchers with more accurate and detailed tRNA annotation for a wider variety of tRNAs, and may direct attention to tRNAs with novel traits.
Long-Term Exposure to Elevated Lipoprotein(a) Levels, Parental Lifespan and Risk of Mortality
Authors: Arsenault Benoit J. , Pelletier William , Kaiser Yannick , Perrot Nicolas , Couture Christian , Khaw Kay-Tee , Wareham Nicholas J. , Bossé Yohan , Pibarot Philippe , Stroes Erik S.G. , Mathieu Patrick , Thériault Sébastien , Boekholdt S. Matthijs 
Published: April 2019

ABSTRACTBackgroundElevated Lipoprotein(a) (Lp[a]) levels are associated with a broad range of atherosclerotic cardiovascular diseases (CVD). The impact of high Lp(a) levels on human longevity is however controversial. Our objectives were to determine whether genetically-determined Lp(a) levels are associated with parental lifespan and to assess the association between measured and genetically-determined Lp(a) levels and long-term all-cause and cardiovascular mortality.MethodsWe determined the association between a genetic risk score of 26 single nucleotide polymorphisms weighted for their impact on Lp(a) levels (wGRS) and parental lifespan (at least one long-lived parent; father still alive and older than 90 or father’s age of death ≥90 or mother still alive and older than 93 or mother’s age of death ≥93) in 139,362 participants from the UK Biobank. A total of 17,686 participants were considered as having high parental lifespan. We also investigated the association between Lp(a) levels and all-cause and cardiovascular mortality in 18,720 participants from the EPIC-Norfolk study.ResultsIn the UK Biobank, increases in the wGRS (weighted for a 50 mg/dL increase in Lp(a) levels) were inversely associated with a high parental lifespan (odds ratio=0.92, 95% confidence interval [CI]=0.89-0.94, p=2.7×10−8). During the 20-year follow-up of the EPIC-Norfolk study, 5686 participants died (2412 from CVD-related causes). Compared to participants with Lp(a) levels <50 mg/dL, those with Lp(a) levels ≥50 mg/dL had an increased hazard ratio (HR) for all-cause (HR=1.17, 95% CI=1.08-1.27) and cardiovascular (HR=1.54, 95% CI=1.37-1.72) mortality. Compared to individuals with Lp(a) levels below the 50th percentile of the Lp(a) distribution (in whom event rates were 29.8% and 11.3%, respectively for all-cause and cardiovascular mortality), those with Lp(a) levels equal or above the 95th percentile of the population distribution (≥70 mg/dL) had HRs of 1.22 (95% CI=1.09-1.37, event rate 37.5%) and 1.71 (95% CI=1.46-2.00, event rate 20.0%), for all-cause mortality and cardiovascular mortality, respectively.ConclusionsResults of this study suggest a potentially causal effect of Lp(a) on human longevity, support the use of parental lifespan as a tool to study the genetic determinants of human longevity, and provide a rationale for a trial of Lp(a)-lowering therapy in individuals with high Lp(a) levels.
Predicting the time of entry of nanoparticles in cellular membranes
Authors: Liu Changjiang , Elvati Paolo , Majumder Sagardip , Wang Yichun , Liu Allen , Violi Angela 
Published: April 2019

AbstractThe understanding of the molecular interactions between nanoparticles (NPs) and biological systems is crucial for the systematic advance in many high-impact fields, such as biomedicine and nanotechnology. A key aspect to understand and predict the biological effect of NPs, e.g., cytotoxicity, bioavailability, is their interaction with membranes, specifically the mechanisms that regulate passive transport, which controls the permeation of most small molecules. In this paper, we introduce a new streamlined theoretical model that is able to predict the interactions between NPs and biological membranes (average permeation time), by separating the NPs’ characteristics (i.e., size, shape, solubility) from the membrane properties (density distribution). This factorization allows the inclusion of data obtained from both experimental and computational sources, as well as rapid estimation of large sets of permutation in new membranes. We validated our approach, by comparing our prediction for the interactions between different carbonaceous NPs and lipid bilayers with both experiments of measuring graphene quantum dot leakage encapsulated in lipid vesicles and time of entry from MD simulations.
Modification of an atypical clathrin-independent AP-2 adaptin complex of Plasmodium falciparum reduces susceptibility to artemisinin
Authors: Henrici Ryan C. , Edwards Rachel L. , Zoltner Martin , van Schalkwyk Donelly A. , Hart Melissa N. , Mohring Franziska , Moon Robert W. , Nofal Stephanie D. , Patel Avnish , Flueck Christian , Baker David A. , John Audrey Odom , Field Mark C. , Sutherland Colin J. 
Published: April 2019

SummaryThe efficacy of current antimalarial drugs is threatened by reduced susceptibility of Plasmodium falciparum to artemisinin. In the Mekong region this is associated with mutations in the kelch propeller-encoding domain of pfkelch13, but variants of other parasite proteins are also thought to modulate the response to drug. Evidence from human and rodent studies suggests that the μ-subunit of the AP-2 adaptin trafficking complex is one such protein of interest. We generated transgenic Plasmodium falciparum parasites encoding the I592T variant of pfap2μ, orthologous to the I568T mutation associated with in vivo artemisinin resistance in P. chabaudi. When exposed to a four-hour pulse of dihydroartemisin in the ring-stage survival assay, two P. falciparum clones expressing AP-2μ I592T displayed significant and reproducible survival of 8.0% and 10.3%, respectively, compared to <2% for the 3D7 parental line (P = 0.0011 for each clone). In immunoprecipitation and localisation studies of HA-tagged AP-2μ, we identified interacting partners including AP-2α, AP-1/2β, AP-2σ and a kelch-domain protein encoded on chromosome 10 of P. falciparum, K10. Conditional knockout indicates that the AP-2 trafficking complex in P. falciparum is essential for the fidelity of merozoite biogenesis and membrane organisation in the mature schizont. We also show that while other heterotetrameric AP-complexes and secretory factors interact with clathrin, AP-2 complex subunits do not. Thus, the AP-2 complex may be diverted from a clathrin-dependent endocytic role seen in most eukaryotes into a Plasmodium-specific function. These findings represent striking divergences from eukaryotic dogma and support a role for intracellular traffic in determining artemisinin sensitivity in vitro, confirming the existence of multiple functional routes to reduced ring-stage artemisinin susceptibility. Therefore, the utility of pfkelch13 variants as resistance markers is unlikely to be universal, and phenotypic surveillance of parasite susceptibility in vivo may be needed to identify threats to our current combination therapies.
Reevaluation of the RNA binding properties of the Tetrahymena thermophila telomerase reverse transcriptase N-terminal domain
Authors: Palka Christina , Deshpande Aishwarya P. , Stone Michael D. , Collins Kathleen 
Published: April 2019

ABSTRACTTelomerase restores chromosome-capping telomeric repeats lost with each round of genome replication by DNA-templated DNA polymerases. The telomerase reverse transcriptase (TERT) N-terminal (TEN) domain is a peripheral, telomerase-specific, processivity-stimulatory addition to more conserved domains that encircle the active site cavity. Reports of ciliate, yeast, and mammalian telomerase TEN domain associations with the telomerase RNA subunit (TR) describe low affinity interactions of uncertain specificity. Unfortunately two cryo-EM structures of synthesis-paused telomerase holoenzymes lack sufficient resolution to discriminate molecular specificity of possible TR contact(s) with the TEN domain, and there is no assigned density for the TEN domain termini implicated in RNA binding. Furthermore, studies have revealed alternative secondary structures for TR regions that could interact with TERT prior to TR folding into active conformation. Informed by recent advances in knowledge of telomerase structure, we returned to the investigation of Tetrahymena thermophila TERT TEN domain interaction with TR. Instead of finding specificity for a particular TR sequence or structure, we discovered that the tagged TEN domain used in previous characterizations has trace contamination with a bacterial RNA-interacting protein not detectable by SDS-PAGE. By resolving this interference, we show that the TEN domain binds RNAs dependent on RNA length rather than sequence.
Proinflammatory and autoimmunogenic gut microbiome in systemic lupus erythematosus
Authors: Chen Bei-di , Jia Xin-miao , Xu Jia-yue , Zhao Li-dan , Ji Jun-yi , Wu Bing-xuan , Fei Yun-yun , Yang Hua-xia , Chen Hua , Zuo Xiao-xia , Li Hui , Pan Wen-you , Wang Xiao-han , Ye Shuang , Guo Dong-geng , Wang Li , Li Jing , Peng Lin-yi , Zheng Wen-jie , Zhang Wen , Zhang Feng-chun , Zhang Jian-min , He Wei , Cao Xue-tao , Liu De-pei , Wang Jun , Zhang Xuan 
Published: April 2019

AbstractSystemic lupus erythematosus (SLE), characterized by chronic inflammation and multi-organ damage, has been suggested to associate with gut dysbiosis, but knowledge is limited from small sample size and 16s rRNA-based studies. To shed new light on the role of microbiota in SLE development, we analyzed the fecal metagenome of 117 treatment-naïve SLE patients and 115 sex- and age-matched healthy controls (HC) by deep-sequencing; in addition, 52 of the aforementioned patients have post-treatment fecal metagenome for comparison. We found significant differences in microbial composition and function between SLE and HC, revealing multiple plausible contributing bacterial species and metabolic pathways in SLE. In-depth SNP-based analysis revealed an oral-microbiome origin for two marker species, strengthening the importance of bacterial translocation in disease development. Lastly, we confirmed experimentally that peptides of SLE-enriched species mimicking autoantigens such as Sm and Fas could trigger autoimmune responses, suggesting a potential causal role of gut microbiota in SLE.
Light environment drives the shallow to mesophotic coral community transition
Authors: Tamir Raz , Eyal Gal , Kramer Netanel , Laverick Jack H. , Loya Yossi 
Published: April 2019

AbstractLight quality is a crucial physical factor driving coral distribution along depth gradients. Currently, a 30 m depth limit, based on SCUBA regulations, separates shallow and deep mesophotic coral ecosystems (MCEs). This definition, however, fails to explicitly accommodate environmental variation. Here, we posit a novel definition for a regional or reef-to-reef outlook of MCEs based on the light vs. coral community-structure relationship. A combination of physical and ecological methods enabled us to clarify the ambiguity in relation to that issue. To characterize coral community structure with respect to the light environment, we conducted wide-scale spatial studies at five sites along shallow and MCEs of the Gulf of Eilat/Aqaba (0-100 m depth). Surveys were conducted by Tech-diving and drop-cameras, in addition to one year of light spectral measurements. We quantify two distinct coral assemblages: shallow (<40 m), and MCEs (40-100 m), exhibiting markedly different relationships with light. The depth ranges and morphology of 47 coral genera, was better explained by light than depth, mainly, due to the Photosynthetically Active Radiation (PAR) and Ultra Violet Radiation (1% at 76 m and 36 m, respectively). Branching coral species were found mainly at shallower depths i.e., down to 36 m. Among the abundant upper mesophotic specialist-corals,Leptoseris glabra,Euphyllia paradivisaandAlveoporaspp., were found strictly between 36-76 m depth. The only lower mesophotic-specialist,Leptoseris fragilis, was found deeper than 80 m. We suggest that shallow coral genera are light-limited below a level of 1.25% surface PAR and that the optimal PAR for mesophotic communities is at 7.5%. This study contributes to moving MCEs ecology from a descriptive-phase into identifying key ecological and physiological processes structuring MCE coral communities. Moreover, it may serve as a model enabling the description of a coral zonation world-wide on the basis of light quality data.
Cortical ensemble activity discriminates auditory attentional states
Authors: Yao Pan-tong , Shen Jia , Chen Liang , Ge Shaoyu , Xiong Qiaojie 
Published: April 2019

AbstractSelective attention modulates sensory cortical activity. It remains unclear how auditory cortical activity represents stimuli that differ behaviorally. We designed a cross-modality task in which mice made decisions to obtain rewards based on attended visual or auditory stimuli. We recorded auditory cortical activity in behaving mice attending to, ignoring, or passively hearing auditory stimuli. Engaging in the task bidirectionally modulates neuronal responses to the auditory stimuli in both the attended and ignored conditions compared to passive hearing. Neuronal ensemble activity in response to stimuli under attended, ignored and passive conditions are readily distinguishable. Furthermore, ensemble activity under attended and ignored conditions are in closer states compared to passive condition, and they share a component of attentional modulation which drives them to the same direction in the population activity space. Our findings suggest that task engagement changes sensory cortical representations across modalities in the same directions, and cross-modality attention may differentially modulates attended and ignored modalities.
Competence ofCorynebacterium glutamicumas a host for the production of type I polyketides
Authors: Kallscheuer Nicolai , Kage Hirokazu , Milke Lars , Nett Markus , Marienhagen Jan 
Published: April 2019

AbstractType I polyketide synthases (PKSs) are large multi-domain proteins converting simple acyl-CoA thioesters such as acetyl-CoA and malonyl-CoA to a large diversity of biotechnologically interesting molecules. Such multi-step reaction cascades are of particular interest for applications in engineered microbial cell factories, as the introduction of a single protein with many enzymatic activities does not require balancing of several individual enzymatic activities. However, functional introduction of type I PKSs into heterologous hosts is very challenging as the large polypeptide chains often do not fold properly. In addition, PKS usually require post-translational activation by dedicated 4’-phosphopantetheinyl transferases (PPTases). Here, we introduce an engineeredCorynebacterium glutamicumstrain as a novel microbial cell factory for type I PKS-derived products. Suitability ofC. glutamicumfor polyketide synthesis could be demonstrated by the functional introduction of the 6-methylsalicylic acid synthase ChlB1 fromStreptomyces antibioticus. Challenges related to protein folding could be overcome by translation fusion of ChlB1Sato the C-terminus of the maltose-binding protein MalE fromEscherichia coli. Surprisingly, ChlB1Sawas also active in absence of a heterologous PPTase, which finally led to the discovery that the endogenous PPTase PptACgofC. glutamicumcan also activate ChlB1Sa. The best strain, engineered to provide increased levels of acetyl-CoA and malonyl-CoA, accumulated up to 41 mg/L (0.27 mM) 6-methylsalicylic acid within 48 h of cultivation. Further experiments showed that PptACgofC. glutamicumcan also activate nonribosomal peptide synthetases (NRPSs), renderingC. glutamicuma promising microbial cell factory for the production of several fine chemicals and medicinal drugs.
Targeting RET Kinase in Neuroendocrine Prostate Cancer
Authors: VanDeusen Halena , Ramroop Johnny R. , Morel Katherine L. , Sheahan Anjali V , Sychev Zoi , Lau Nathan A. , Cheng Larry C. , Tan Victor , Li Zhen , Petersen Ashley , Lee John K. , Park Jung Wook , Yang Rendong , Coleman Ilsa , Witte Owen , Morrissey Colm , Corey Eva , Nelson Peter S. , Ellis Leigh , Drake Justin M. 
Published: April 2019

AbstractIncreased treatment of metastatic castration resistant prostate cancer (mCRPC) with second-generation anti-androgen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost androgen receptor (AR) signaling. AVPC tumors may also express neuroendocrine markers, termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing AR-negative to AR-positive prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-negative cell lines. Clinical NEPC and NEPC patient derived xenografts displayed upregulated RET transcript and RET pathway activity. Pharmacologically inhibiting RET kinase in NEPC models dramatically reduced tumor growth and cell viability in mouse and human NEPC models. Our results suggest that targeting RET in NEPC tumors with high RET expression and may be a novel treatment option.Statement of SignificanceThere are limited treatment options for patients with metastatic aggressive variant prostate cancer and none are curative. Here we identified aberrantly activated RET kinase signaling in multiple models of NEPC. Inhibiting RET restricted tumor growth, providing a novel approach for treating NEPC.
Cyclosporine A Directly Affects Human and Mouse B cell Migration in vitro by Disrupting a HIF-1α Dependent, O2 Sensing, Molecular Switch
Authors: Hilchey Shannon P , Palshikar Mukta G , Li Dongmei , Garigen Jessica , Cipolla Valantina , Thakar Juilee , Zand Martin S 
Published: April 2019

AbstractBackgroundHypoxia is a potent molecular signal for cellular metabolism, mitochondrial function, and migration. Conditions of low oxygen tension trigger regulatory cascades mediated via the highly conserved HIF-1α post-translational modification system. In the adaptive immune response, B cells (Bc) are activated and differentiate under hypoxic conditions within lymph node germinal centers, and subsequently migrate to other compartments. During migration, they traverse through changing oxygen levels, ranging from 1-5% in the lymph node to 5-13% in the peripheral blood. Interestingly, the calcineurin inhibitor cyclosporine A is known to stimulate prolyl hydroxylase activity, resulting in HIF-1α destabilization and may alter Bc responses directly. Over 60% of patients taking calcineurin immunosuppressant medications have hypo-gammaglobulinemia and poor vaccine responses, putting them at high risk of infection with significantly increased morbidity and mortality.ResultsWe demonstrate that O2 tension is a previously unrecognized Bc regulatory switch, altering CXCR4 chemokine receptor signaling in activated Bc through HIF-1α expression and controlling critical aspects of Bc migration. Our data demonstrate that calcineurin inhibition hinders this O2 regulatory switch in primary human Bc.ConclusionThis previously unrecognized effect of calcineurin inhibition directly on human Bc has significant and direct clinical implications.