bluuebunny/crossref_metadata_2025 huggingface dataset:
Human Papillomavirus 16 Infection Induces VAP-Dependent Endosomal Tubulation
Authors: Siddiqa Abida , Massimi Paola , Pim David , Broniarczyk Justyna , Banks Lawrence
Published: January 2018

Human papillomavirus (HPV) infection involves complex interactions with the endocytic transport machinery, which ultimately facilitates the entry of the incoming viral genomes into the
trans
-Golgi network (TGN) and their subsequent nuclear entry during mitosis. The endosomal pathway is a highly dynamic intracellular transport system, which consists of vesicular compartments and tubular extensions, although it is currently unclear whether incoming viruses specifically alter the endocytic machinery. In this study, using MICAL-L1 as a marker for tubulating endosomes, we show that incoming HPV-16 virions induce a profound alteration in global levels of endocytic tubulation. In addition, we also show a critical requirement for the endoplasmic reticulum (ER)-anchored protein VAP in this process. VAP plays an essential role in actin nucleation and endosome-to-Golgi transport. Indeed, the loss of VAP results in a dramatic decrease in the level of endosomal tubulation induced by incoming HPV-16 virions. This is also accompanied by a marked reduction in virus infectivity. In VAP knockdown cells, we see that the defect in virus trafficking occurs after capsid disassembly but prior to localization at the
trans
-Golgi network, with the incoming virion-transduced DNA accumulating in Vps29/TGN46-positive hybrid vesicles. Taken together, these studies demonstrate that infection with HPV-16 virions induces marked alterations of endocytic transport pathways, some of which are VAP dependent and required for the endosome-to-Golgi transport of the incoming viral L2/DNA complex.

IMPORTANCE
Human papillomavirus infectious entry involves multiple interactions with the endocytic transport machinery. In this study, we show that incoming HPV-16 virions induce a dramatic increase in endocytic tubulation. This tubulation requires ER-associated VAP, which plays a critical role in ensuring the delivery of cargoes from the endocytic compartments to the
trans
-Golgi network. Indeed, the loss of VAP blocks HPV infectious entry at a step after capsid uncoating but prior to localization at the
trans
-Golgi network. These results define a critical role for ER-associated VAP in endocytic tubulation and in HPV-16 infectious entry.
Determinants in the Ig Variable Domain of Human HAVCR1 (TIM-1) Are Required To Enhance Hepatitis C Virus Entry
Authors: Kachko Alla , Costafreda Maria Isabel , Zubkova Iryna , Jacques Jerome , Takeda Kazuyo , Wells Frances , Kaplan Gerardo , Major Marian E.
Published: January 2018

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis in humans. Several host molecules participate in HCV cell entry, but this process remains unclear. The complete unraveling of the HCV entry process is important to further understand viral pathogenesis and develop therapeutics. Human hepatitis A virus (HAV) cellular receptor 1 (HAVCR1), CD365, also known as TIM-1, functions as a phospholipid receptor involved in cell entry of several enveloped viruses. Here, we studied the role of HAVCR1 in HCV infection. HAVCR1 antibody inhibited entry in a dose-dependent manner. HAVCR1 soluble constructs neutralized HCV, which did not require the HAVCR1 mucinlike region and was abrogated by a mutation of N to A at position 94 (N94A) in the Ig variable (IgV) domain phospholipid-binding pocket, indicating a direct interaction of the HAVCR1 IgV domain with HCV virions. However, knockout of HAVCR1 in Huh7 cells reduced but did not prevent HCV growth. Interestingly, the mouse HAVCR1 ortholog, also a phospholipid receptor, did not enhance infection and a soluble form failed to neutralize HCV, although replacement of the mouse IgV domain with the human HAVCR1 IgV domain restored the enhancement of HCV infection. Mutations in the cytoplasmic tail revealed that direct HAVCR1 signaling is not required to enhance HCV infection. Our data show that the phospholipid-binding function and other determinant(s) in the IgV domain of human HAVCR1 enhance HCV infection. Although the exact mechanism is not known, it is possible that HAVCR1 facilitates entry by stabilizing or enhancing attachment, leading to direct interactions with specific receptors, such as CD81.

IMPORTANCE
Hepatitis C virus (HCV) enters cells through a multifaceted process. We identified the human hepatitis A virus cellular receptor 1 (HAVCR1), CD365, also known as TIM-1, as a facilitator of HCV entry. Antibody blocking and silencing or knockout of HAVCR1 in hepatoma cells reduced HCV entry. Our findings that the interaction of HAVCR1 with HCV early during infection enhances entry but is not required for infection support the hypothesis that HAVCR1 facilitates entry by stabilizing or enhancing virus binding to the cell surface membrane and allowing the correct virus-receptor positioning for interaction with the main HCV receptors. Furthermore, our data show that in addition to the phospholipid-binding function of HAVCR1, the enhancement of HCV infection involves other determinants in the IgV domain of HAVCR1. These findings expand the repertoire of molecules that HCV uses for cell entry, adding to the already complex mechanism of HCV infection and pathogenesis.
Paramyxovirus V Proteins Interact with the RIG-I/TRIM25 Regulatory Complex and Inhibit RIG-I Signaling
Authors: Sánchez-Aparicio Maria T. , Feinman Leighland J. , García-Sastre Adolfo , Shaw Megan L.
Published: January 2018

Paramyxovirus V proteins are known antagonists of the RIG-I-like receptor (RLR)-mediated interferon induction pathway, interacting with and inhibiting the RLR MDA5. We report interactions between the Nipah virus V protein and both RIG-I regulatory protein TRIM25 and RIG-I. We also observed interactions between these host proteins and the V proteins of measles virus, Sendai virus, and parainfluenza virus. These interactions are mediated by the conserved C-terminal domain of the V protein, which binds to the tandem caspase activation and recruitment domains (CARDs) of RIG-I (the region of TRIM25 ubiquitination) and to the SPRY domain of TRIM25, which mediates TRIM25 interaction with the RIG-I CARDs. Furthermore, we show that V interaction with TRIM25 and RIG-I prevents TRIM25-mediated ubiquitination of RIG-I and disrupts downstream RIG-I signaling to the mitochondrial antiviral signaling protein. This is a novel mechanism for innate immune inhibition by paramyxovirus V proteins, distinct from other known V protein functions such as MDA5 and STAT1 antagonism.

IMPORTANCE
The host RIG-I signaling pathway is a key early obstacle to paramyxovirus infection, as it results in rapid induction of an antiviral response. This study shows that paramyxovirus V proteins interact with and inhibit the activation of RIG-I, thereby interrupting the antiviral signaling pathway and facilitating virus replication.
Exploration of the Germline Genome of the Ciliate
Chilodonella uncinata
through Single-Cell Omics (Transcriptomics and Genomics)
Authors: Maurer-Alcalá Xyrus X. , Knight Rob , Katz Laura A.
Published: January 2018

Separate germline and somatic genomes are found in numerous lineages across the eukaryotic tree of life, often separated into distinct tissues (e.g., in plants, animals, and fungi) or distinct nuclei sharing a common cytoplasm (e.g., in ciliates and some foraminifera). In ciliates, germline-limited (i.e., micronuclear-specific) DNA is eliminated during the development of a new somatic (i.e., macronuclear) genome in a process that is tightly linked to large-scale genome rearrangements, such as deletions and reordering of protein-coding sequences. Most studies of germline genome architecture in ciliates have focused on the model ciliates
Oxytricha trifallax
,
Paramecium tetraurelia
, and
Tetrahymena thermophila
, for which the complete germline genome sequences are known. Outside of these model taxa, only a few dozen germline loci have been characterized from a limited number of cultivable species, which is likely due to difficulties in obtaining sufficient quantities of “purified” germline DNA in these taxa. Combining single-cell transcriptomics and genomics, we have overcome these limitations and provide the first insights into the structure of the germline genome of the ciliate
Chilodonella uncinata
, a member of the understudied class
Phyllopharyngea
. Our analyses reveal the following: (i) large gene families contain a disproportionate number of genes from scrambled germline loci; (ii) germline-soma boundaries in the germline genome are demarcated by substantial shifts in GC content; (iii) single-cell omics techniques provide large-scale quality germline genome data with limited effort, at least for ciliates with extensively fragmented somatic genomes. Our approach provides an efficient means to understand better the evolution of genome rearrangements between germline and soma in ciliates.

IMPORTANCE
Our understanding of the distinctions between germline and somatic genomes in ciliates has largely relied on studies of a few model genera (e.g.,
Oxytricha
,
Paramecium
,
Tetrahymena
). We have used single-cell omics to explore germline-soma distinctions in the ciliate
Chilodonella uncinata
, which likely diverged from the better-studied ciliates ~700 million years ago. The analyses presented here indicate that developmentally regulated genome rearrangements between germline and soma are demarcated by rapid transitions in local GC composition and lead to diversification of protein families. The approaches used here provide the basis for future work aimed at discerning the evolutionary impacts of germline-soma distinctions among diverse ciliates.
ATG8 Is Essential Specifically for an Autophagy-Independent Function in Apicoplast Biogenesis in Blood-Stage Malaria Parasites
Authors: Walczak Marta , Ganesan Suresh M. , Niles Jacquin C. , Yeh Ellen
Published: January 2018

Plasmodium
parasites and related pathogens contain an essential nonphotosynthetic plastid organelle, the apicoplast, derived from secondary endosymbiosis. Intriguingly, a highly conserved eukaryotic protein, autophagy-related protein 8 (ATG8), has an autophagy-independent function in the apicoplast. Little is known about the novel apicoplast function of ATG8 and its importance in blood-stage
Plasmodium falciparum
. Using a
P. falciparum
strain in which ATG8 expression was conditionally regulated, we showed that
P. falciparum
ATG8 (
Pf
ATG8) is essential for parasite replication. Significantly, growth inhibition caused by the loss of
Pf
ATG8 was reversed by addition of isopentenyl pyrophosphate (IPP), which was previously shown to rescue apicoplast defects in
P. falciparum
. Parasites deficient in
Pf
ATG8, but whose growth was rescued by IPP, had lost their apicoplast. We designed a suite of functional assays, including a new fluorescence
in situ
hybridization (FISH) method for detection of the low-copy-number apicoplast genome, to interrogate specific steps in apicoplast biogenesis and detect apicoplast defects which preceded the block in parasite replication. Though protein import and membrane expansion of the apicoplast were unaffected, the apicoplast was not inherited by daughter parasites. Our findings demonstrate that, though multiple autophagy-dependent and independent functions have been proposed for
Pf
ATG8, only its role in apicoplast biogenesis is essential in blood-stage parasites. We propose that
Pf
ATG8 is required for fission or segregation of the apicoplast during parasite replication.

IMPORTANCE
Plasmodium
parasites, which cause malaria, and related apicomplexan parasites are important human and veterinary pathogens. They are evolutionarily distant from traditional model organisms and possess a unique plastid organelle, the apicoplast, acquired by an unusual eukaryote-eukaryote endosymbiosis which established novel protein/lipid import and organelle inheritance pathways in the parasite cell. Though the apicoplast is essential for parasite survival in all stages of its life cycle, little is known about these novel biogenesis pathways. We show that malaria parasites have adapted a highly conserved protein required for macroautophagy in yeast and mammals to function specifically in apicoplast inheritance. Our finding elucidates a novel mechanism of organelle biogenesis, essential for pathogenesis, in this divergent branch of pathogenic eukaryotes.
Development and Validation of a Serologic Test Panel for Detection of Powassan Virus Infection in U.S. Patients Residing in Regions Where Lyme Disease Is Endemic
Authors: Thomm Angela M. , Schotthoefer Anna M. , Dupuis Alan P. , Kramer Laura D. , Frost Holly M. , Fritsche Thomas R. , Harrington Yvette A. , Knox Konstance K. , Kehl Sue C.
Published: January 2018

Approximately 100 cases of POWV disease were reported in the United States over the past 10 years. Most cases have occurred in the Northeast (52) and Great Lakes (45) regions (
https://www.cdc.gov/powassan/statistics.html
). The prevalence of POWV in ticks and mammals is increasing, and POWV poses an increasing threat in a greater geographical range. In areas of the Northeast and Midwest where Lyme disease is endemic, POWV testing is recommended for patients with a recent tick bite, patients with Lyme disease who have been treated with antibiotics, or patients with a tick exposure who have tested negative for Lyme disease or other tick-borne illnesses and have persistent symptoms consistent with posttreatment Lyme disease. Testing could also benefit patients with tick exposure and unexplained neurologic symptoms and chronic fatigue syndrome (CFS) patients with known tick exposure. Until now, diagnostic testing for Powassan virus has not been commercially available and has been limited to patients presenting with severe, neurologic complications. The lack of routine testing for Powassan virus in patients with suspected tick-borne disease means that little information is available regarding the overall prevalence of the virus and the full spectrum of clinical symptoms associated with infection. As
Ixodes scapularis
is the tick vector for Powassan virus and multiple other tick-borne pathogens, including the Lyme disease bacterium,
Borrelia burgdorferi
, the clinical presentations and long-term outcomes of Powassan virus infection and concurrent infection with other tick-borne disease pathogens remain unknown.
Prey Range and Genome Evolution of Halobacteriovorax marinus Predatory Bacteria from an Estuary
Authors: Enos Brett G. , Anthony Molly K. , DeGiorgis Joseph A. , Williams Laura E.
Published: January 2018

Predatory bacteria attack and digest other bacteria and therefore may play a role in shaping microbial communities. To investigate phenotypic and genotypic variation in saltwater-adapted predatory bacteria, we isolated
Halobacteriovorax marinus
BE01 from an estuary in Rhode Island, assayed whether it could attack different prey bacteria, and sequenced and analyzed its genome. We found that BE01 is a prey generalist, attacking bacteria from different phylogenetic groups and environments. Gene order and amino acid sequences are highly conserved between BE01 and the
H. marinus
type strain, SJ. By comparative genomics, we detected two regions of gene content difference that likely occurred via horizontal gene transfer events. Acquired genes encode functions such as modification of DNA, membrane synthesis and regulation of gene expression. Understanding genome evolution and variation in predation phenotypes among predatory bacteria will inform their development as biocontrol agents and clarify how they impact microbial communities.
Studying the Symbiotic Bacterium Xenorhabdus nematophila in Individual, Living
Steinernema carpocapsae
Nematodes Using Microfluidic Systems
Authors: Stilwell Matthew D. , Cao Mengyi , Goodrich-Blair Heidi , Weibel Douglas B.
Published: January 2018

This paper describes an experimental system for directly investigating population dynamics of a symbiotic bacterium,
Xenorhabdus nematophila
, in its host—the infective stage of the entomopathogenic nematode
Steinernema carpocapsae
. Tracking individual and groups of bacteria in individual host nematodes over days and weeks yielded insight into dynamic growth and topology changes of symbiotic bacterial populations within infective juvenile nematodes. Our approach for studying symbioses between bacteria and nematodes provides a system to investigate long-term host-microbe interactions in individual nematodes and extrapolate the lessons learned to other bacterium-animal interactions.
Antibiotic Treatments for Clostridium difficile Infection Are Associated with Distinct Bacterial and Fungal Community Structures
Authors: Lamendella Regina , Wright Justin R. , Hackman Jada , McLimans Christopher , Toole David R. , Bernard Rubio William , Drucker Rebecca , Wong Hoi Tong , Sabey Kate , Hegarty John P. , Stewart David B.
Published: January 2018

Using human fecal samples and including sequencing for both bacterial and fungal taxa, this study compared the conventional antibiotics used to treat
C. difficile
infection (CDI) from the perspective of the microbiome, which is particularly relevant, given the relationship between dysbiotic states and the development of CDI. Sequencing and imputed functional analyses suggest that
C. difficile
-directed antibiotics are associated with distinct forms of dysbiosis that may be influential in the course of CDI. Further, a role for fungal organisms in the perpetuation of the causal dysbiosis of CDI is discussed, suggesting a previously unappreciated, clinically relevant transkingdom interaction that warrants further study.
Stability of the Influenza Virus Hemagglutinin Protein Correlates with Evolutionary Dynamics
Authors: Klein Eili Y. , Blumenkrantz Deena , Serohijos Adrian , Shakhnovich Eugene , Choi Jeong-Mo , Rodrigues João V. , Smith Brendan D. , Lane Andrew P. , Feldman Andrew , Pekosz Andrew
Published: January 2018

One of the constraints on fast-evolving viruses, such as influenza virus, is protein stability, or how strongly the folded protein holds together. Despite the importance of this protein property, there has been limited investigation of the impact of the stability of the influenza virus hemagglutinin protein—the primary antibody target of the immune system—on its evolution. Using a combination of computational estimates of stability and experiments, our analysis found that viruses with more-stable hemagglutinin proteins were associated with long-term persistence in the population. There are two potential reasons for the observed persistence. One is that more-stable proteins tolerate destabilizing mutations that less-stable proteins could not, thus increasing opportunities for immune escape. The second is that greater stability increases the fitness of the virus through increased production of infectious particles. Further research on the relative importance of these mechanisms could help inform the annual influenza vaccine composition decision process.
Machine Learning Leveraging Genomes from Metagenomes Identifies Influential Antibiotic Resistance Genes in the Infant Gut Microbiome
Authors: Rahman Sumayah F. , Olm Matthew R. , Morowitz Michael J. , Banfield Jillian F.
Published: January 2018

The process of reconstructing genomes from environmental sequence data (genome-resolved metagenomics) allows unique insight into microbial systems. We apply this technique to investigate how the antibiotic resistance genes of bacteria affect their ability to flourish in the gut under various conditions. Our analysis reveals that strain-level selection in formula-fed infants drives enrichment of beta-lactamase genes in the gut resistome. Using genomes from metagenomes, we built a machine learning model to predict how organisms in the gut microbial community respond to perturbation by antibiotics. This may eventually have clinical applications.
Optimal Independent Pricing Strategies of Dual-Channel Supply Chain Based on Risk-Aversion Attitudes
Authors: Liu Zheng , Xu Qi , Yang Kun
Published: January 2018

Dual-channel supply chain system, channel optimization is influenced by channel attitude toward risk, in which risk is classified as general risk and interruption risk. To consider lead time may bring out supply conflicts, substitution effect of online channel and ratio of promotional cost are introduced and an independent model is developed. Based on that, the impact of interruption risk under risk-aversion attitude on both channels is further studied. Finally, it is proved how the risk attitude influences pricing and profit strategy.
A Novel Gating Approach to Alleviate Power and Ground Noise in Silicon Chips
Authors: Majumder Alak , Bhattacharjee Pritam , Das Tushar Dhabal
Published: January 2018

As the performing ability of a silicon chip relies on the power supply voltage, it must be configured using genuine power and ground bond pads for mitigating power and ground noise (PGN), which is directly boosted by the increasing peaks of instantaneous current [Formula: see text] and current ramp [Formula: see text]. To address the same, a novel and compact clock gating (CG) scheme is unveiled in this paper to effectively control the peak of [Formula: see text] and [Formula: see text], thereby subduing PGN. The new CG arrangement is simulated for 90[Formula: see text]nm Predictive Technology Model (PTM90), where it is observed that the scheme reduces 88.80% of [Formula: see text] and 84.19% of average [Formula: see text] in comparison to its no gating counterpart along with a reduction of 80.14% in average power dissipation. These results are found to be more prominent when the proposed circuit configuration is tested in 90[Formula: see text]nm Generic Process Design Kit (GPDK90), proclaiming 88.75% and 84.34% reduction in average [Formula: see text] and average power, respectively, to illustrate its capability of truncating PGN in silicon chips.
Design of Low-Power WiNoC with Congestion-Aware Wireless Node
Authors: Ouyang Yiming , Li Zhe , Xing Kun , Huang Zhengfeng , Liang Huaguo , Li Jianhua
Published: January 2018

As the key component of wireless network-on-chip (WiNoC), wireless router is required to handle a large number of data packets which could cause network congestion. The congestion not only reduces the network performance, but also results in additional power consumption. In this paper, a low-power WiNoC with congestion-aware wireless node is proposed. Firstly, flit counter unit and address resolution unit are added in wireless interface (WI), which can sense the congestion information and destination address information of each wireless node dynamically. Secondly, through the proposed congestion judgment algorithm, the congestion judgment unit in global network can judge the priority of each wireless node pair and set the highest-priority wireless node pair to use the channel resources preferentially. The mechanism can effectively alleviate the congestion of wireless nodes and ensure the stability of system performance. In addition, a sleep mechanism is utilized to switch off WI which fails in the wireless channel competition. Experimental results show that the proposed scheme can effectively improve the performance in terms of packets’ transmission latency and network throughput.
A Numerical Study of New Logistic Map
Authors: Khmou Youssef
Published: January 2018

In this paper, we propose a new logistic map based on the relation of the information entropy, we study the bifurcation diagram comparatively to the standard logistic map. In the first part, we compare the obtained diagram, by numerical simulations, with that of the standard logistic map. It is found that the structures of both diagrams are similar where the range of the growth parameter is restricted to the interval [0,e]. In the second part, we present an application of the proposed map in traffic flow using macroscopic model. It is found that the bifurcation diagram is an exact model of the Greenberg’s model of traffic flow where the growth parameter corresponds to the optimal velocity and the random sequence corresponds to the density. In the last part, we present a second possible application of the proposed map which consists of random number generation. The results of the analysis show that the excluded initial values of the sequences are (0,1).
The SLC22 Transporter Family: A Paradigm for the Impact of Drug Transporters on Metabolic Pathways, Signaling, and Disease
Authors: Nigam Sanjay K.
Published: January 2018

The SLC22 transporter family consists of more than two dozen members, which are expressed in the kidney, the liver, and other tissues. Evolutionary analysis indicates that SLC22 transporters fall into at least six subfamilies: OAT (organic anion transporter), OAT-like, OAT-related, OCT (organic cation transporter), OCTN (organic cation/carnitine transporter), and OCT/OCTN-related. Some—including OAT1 [SLC22A6 or NKT (novel kidney transporter)] and OAT3 (SLC22A8), as well as OCT1 (SLC22A1) and OCT2 (SLC22A2)—are widely studied drug transporters. Nevertheless, analyses of knockout mice and other data indicate that SLC22 transporters regulate key metabolic pathways and levels of signaling molecules (e.g., gut microbiome products, bile acids, tricarboxylic acid cycle intermediates, dietary flavonoids and other nutrients, prostaglandins, vitamins, short-chain fatty acids, urate, and ergothioneine), as well as uremic toxins associated with chronic kidney disease. Certain SLC22 transporters—such as URAT1 (SLC22A12) and OCTN2 (SLC22A5)—are mutated in inherited metabolic diseases. A new systems biology view of transporters is emerging. As proposed in the remote sensing and signaling hypothesis, SLC22 transporters, together with other SLC and ABC transporters, have key roles in interorgan and interorganism small-molecule communication and, together with the neuroendocrine, growth factor–cytokine, and other homeostatic systems, regulate local and whole-body homeostasis.
Acute small intestinal inflammation results in persistent lymphatic alterations
Authors: Rehal Sonia , Stephens Matthew , Roizes Simon , Liao Shan , von der Weid Pierre-Yves
Published: January 2018

Inflammatory bowel disease (IBD) has a complex pathophysiology with limited treatments. Structural and functional changes in the intestinal lymphatic system have been associated with the disease, with increased risk of IBD occurrence linked to a history of acute intestinal injury. To examine the potential role of the lymphatic system in inflammation recurrence, we evaluated morphological and functional changes in mouse mucosal and mesenteric lymphatic vessels, and within the mesenteric lymph nodes during acute ileitis caused by a 7-day treatment with dextran sodium sulfate (DSS). We monitored whether the changes persisted during a 14-day recovery period and determined their potential consequences on dendritic cell (DC) trafficking between the mucosa and lymphoid tissues. DSS administration was associated with marked lymphatic abnormalities and dysfunctions exemplified by lymphangiectasia and lymphangiogenesis in the ileal mucosa and mesentery, increased mesenteric lymphatic vessel leakage, and lymphadenopathy. Lymphangiogenesis and lymphadenopathy were still evident after recovery from intestinal inflammation and correlated with higher numbers of DCs in mucosal and lymphatic tissues. Specifically, a deficit in CD103+ DCs observed during acute DSS in the lamina propria was reversed and further enhanced during recovery. We concluded that an acute intestinal insult caused alterations of the mesenteric lymphatic system, including lymphangiogenesis, which persisted after resolution of inflammation. These morphological and functional changes could compromise DC function and movement, increasing susceptibility to further gastrointestinal disease. Elucidation of the changes in mesenteric and intestinal lymphatic function should offer key insights for new therapeutic strategies in gastrointestinal disorders such as IBD.

NEW & NOTEWORTHY Lymphatic integrity plays a critical role in small intestinal homeostasis. Acute intestinal insult in a mouse model of acute ileitis causes morphological and functional changes in mesenteric and intestinal lymphatic vessels. While some of the changes significantly regressed during inflammation resolution, others persisted, including lymphangiogenesis and altered dendritic cell function and movement, potentially increasing susceptibility to the recurrence of gastrointestinal inflammation.
Vx-809/Vx-770 treatment reduces inflammatory response to Pseudomonas aeruginosa in primary differentiated cystic fibrosis bronchial epithelial cells
Authors: Ruffin Manon , Roussel Lucie , Maillé Émilie , Rousseau Simon , Brochiero Emmanuelle
Published: January 2018

Cystic fibrosis patients exhibit chronic Pseudomonas aeruginosa respiratory infections and sustained proinflammatory state favoring lung tissue damage and remodeling, ultimately leading to respiratory failure. Loss of cystic fibrosis transmembrane conductance regulator (CFTR) function is associated with MAPK hyperactivation and increased cytokines expression, such as interleukin-8 [chemoattractant chemokine (C-X-C motif) ligand 8 (CXCL8)]. Recently, new therapeutic strategies directly targeting the basic CFTR defect have been developed, and ORKAMBI (Vx-809/Vx-770 combination) is the only Food and Drug Administration-approved treatment for CF patients homozygous for the F508del mutation. Here we aimed to determine the effect of the Vx-809/Vx-770 combination on the induction of the inflammatory response by fully differentiated primary bronchial epithelial cell cultures from CF patients carrying F508del mutations, following exposure to P. aeruginosa exoproducts. Our data unveiled that CFTR functional rescue with Vx-809/Vx-770 drastically reduces CXCL8 (as well as CXCL1 and CXCL2) transcripts and p38 MAPK phosphorylation in response to P. aeruginosa exposure through a CFTR-dependent mechanism. These results suggest that ORKAMBI has anti-inflammatory properties that could decrease lung inflammation and contribute to the observed beneficial impact of this treatment in CF patients.
Impact of HIV infection on α1-antitrypsin in the lung
Authors: Stephenson Sarah E. , Wilson Carole L. , Crothers Kristina , Attia Engi F. , Wongtrakool Cherry , Petrache Irina , Schnapp Lynn M.
Published: January 2018

Emphysema is one of the most common lung diseases in HIV+individuals. The pathogenesis of HIV-associated emphysema remains unclear; however, radiographic distribution and earlier age of presentation of emphysema in the lungs of HIV+patients are similar to deficiency of α1-antitrypsin (A1AT), a key elastase inhibitor in the lung. Reduced levels of circulating A1AT in HIV+patients suggest a potential mechanism for emphysema development. In the present study we asked if A1AT levels and activity in the bronchoalveolar lavage fluid (BALF) differ in HIV+and HIV−patients with and without emphysema. A1AT levels were measured by ELISA in plasma and BALF from a cohort of 21 HIV+and 29 HIV−patients with or without emphysematous changes on chest CT scan. To analyze A1AT function, we measured elastase activity in the BALF and assessed oxidation and polymerization of A1AT by Western blotting. Total A1AT was increased in the BALF, but not in the plasma, of HIV+compared with HIV−patients, regardless of the presence or absence of emphysema. However, antielastase activity was decreased in BALF from HIV+patients, suggesting impaired A1AT function. Higher levels of the oxidized form of A1AT were detected in BALF from HIV+than HIV−patients, which may account for the decreased antielastase activity. These findings suggest that, in the lungs of HIV+patients, posttranslational modifications of A1AT produce a “functional deficiency” of this critical elastase inhibitor, which may contribute to emphysema development.
Personalized medicine in CF: from modulator development to therapy for cystic fibrosis patients with rare CFTR mutations
Authors: Harutyunyan Misak , Huang Yunjie , Mun Kyu-Shik , Yang Fanmuyi , Arora Kavisha , Naren Anjaparavanda P.
Published: January 2018

Cystic fibrosis (CF) is the most common life-shortening genetic disease affecting ~1 in 3,500 of the Caucasian population. CF is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. To date, more than 2,000 CFTR mutations have been identified, which produce a wide range of phenotypes. The CFTR protein, a chloride channel, is normally expressed on epithelial cells lining the lung, gut, and exocrine glands. Mutations in CFTR have led to pleiotropic effects in CF patients and have resulted in early morbidity and mortality. Research has focused on identifying small molecules, or modulators, that can restore CFTR function. In recent years, two modulators, ivacaftor (Kalydeco) and lumacaftor/ivacaftor (Orkambi), have been approved by the U.S. Food and Drug Administration to treat CF patients with certain CFTR mutations. The development of these modulators has served as proof-of-concept that targeting CFTR by modulators is a viable therapeutic option. Efforts to discover new modulators that could deliver a wider and greater clinical benefit are still ongoing. However, traditional randomized controlled trials (RCTs) require large numbers of patients and become impracticable to test the modulators’ efficacy in CF patients with CFTR mutations at frequencies much lower than 1%, suggesting the need for personalized medicine in these CF patients.
Feasibility of phase-contrast cine magnetic resonance imaging for measuring blood flow in the sheep fetus
Authors: Duan An Qi , Darby Jack R. T. , Soo Jia Yin , Lock Mitchell C. , Zhu Meng Yuan , Flynn Lucy V. , Perumal Sunthara Rajan , Macgowan Christopher K. , Selvanayagam Joseph B. , Morrison Janna L. , Seed Mike
Published: January 2018

Phase-contrast cine MRI (PC-MRI) is the gold-standard noninvasive technique for measuring vessel blood flow and has previously been applied in the human fetal circulation. We aimed to assess the feasibility of using PC-MRI to define the distribution of the fetal circulation in sheep. Fetuses were catheterized at 119–120 days of gestation (term, 150 days) and underwent MRI at ∼123 days of gestation under isoflurane anesthesia, ventilated at a [Formula: see text] of 1.0. PC-MRI was performed using a fetal arterial blood pressure catheter signal for cardiac triggering. Blood flows were measured in the major fetal vessels, including the main pulmonary artery, ascending and descending aorta, superior vena cava, ductus arteriosus, left and right pulmonary arteries, umbilical vein, ductus venosus, and common carotid artery and were indexed to estimated fetal weight. The combined ventricular output, pulmonary blood flow, and flow across the foramen ovale were calculated from vessel flows. Intraobserver and interobserver agreement and reproducibility was assessed. Blood flow measurements were successfully obtained in 61 out of 74 vessels (82.4%) interrogated in 9 fetuses. There was good intraobserver [ R = 0.998, P < 0.0001; intraclass correlation (ICC) = 0.997] and interobserver agreement ( R = 0.996, P < 0.0001; ICC = 0.996). Repeated MRI measurements showed good reproducibility ( R = 0.989, P = 0.0002; ICC = 0.990). We conclude that PC-MRI using fetal catheters for gating triggers is feasible in the major vessels of late gestation fetal sheep. This approach may provide a useful new tool for assessing the circulatory characteristics of fetal sheep models of human disease, including fetal growth restriction and congenital heart disease.
Role of PTP1B in POMC neurons during chronic high-fat diet: sex differences in regulation of liver lipids and glucose tolerance
Authors: Aberdein Nicola , Dambrino Robert J. , do Carmo Jussara M. , Wang Zhen , Mitchell Laura E. , Drummond Heather A. , Hall John E.
Published: January 2018

Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of leptin receptor signaling and may contribute to leptin resistance in diet-induced obesity. Although PTP1B inhibition has been suggested as a potential weight loss therapy, the role of specific neuronal PTP1B signaling in cardiovascular and metabolic regulation and the importance of sex differences in this regulation are still unclear. In this study, we investigated the impact of proopiomelanocortin (POMC) neuronal PTP1B deficiency in cardiometabolic regulation in male and female mice fed a high-fat diet (HFD). When compared with control mice (PTP1B flox/flox), male and female mice deficient in POMC neuronal PTP1B (PTP1B flox/flox/POMC-Cre) had attenuated body weight gain (males: −18%; females: −16%) and fat mass (males: −33%; female: −29%) in response to HFD. Glucose tolerance was improved by 40%, and liver lipid accumulation was reduced by 40% in PTP1B/POMC-Cre males but not in females. When compared with control mice, deficiency of POMC neuronal PTP1B did not alter mean arterial pressure (MAP) in male or female mice (males: 112 ± 1 vs. 112 ± 1 mmHg in controls; females: 106 ± 3 vs. 109 ± 3 mmHg in controls). Deficiency of POMC neuronal PTP1B also did not alter MAP response to acute stress in males or females compared with control mice (males: Δ32 ± 0 vs. Δ29 ± 4 mmHg; females: Δ22 ± 2 vs. Δ27 ± 4 mmHg). These data demonstrate that POMC-specific PTP1B deficiency improved glucose tolerance and attenuated diet-induced fatty liver only in male mice and attenuated weight gain in males and females but did not enhance the MAP and HR responses to a HFD or to acute stress.
Venous collapse regulates intracranial pressure in upright body positions
Authors: Holmlund P. , Eklund A. , Koskinen L.-O. D. , Johansson E. , Sundström N. , Malm J. , Qvarlander S.
Published: January 2018

Recent interest in intracranial pressure (ICP) in the upright posture has revealed that the mechanisms regulating postural changes in ICP are not fully understood. We have suggested an explanatory model where the postural changes in ICP depend on well-established hydrostatic effects in the venous system and where these effects are interrupted by collapse of the internal jugular veins (IJVs) in more upright positions. The aim of this study was to investigate this relationship by simultaneous invasive measurements of ICP, venous pressure, and IJV collapse in healthy volunteers. ICP (monitored via the lumbar route), central venous pressure (peripherally inserted central catheter line), and IJV cross-sectional area (ultrasound) were measured in 11 healthy volunteers (47 ± 10 yr, mean ± SD) in 7 positions, from supine to sitting (0–69°). Venous pressure and anatomical distances were used to predict ICP in accordance with the explanatory model, and IJV area was used to assess IJV collapse. The hypothesis was tested by comparing measured ICP with predicted ICP. Our model accurately described the general behavior of the observed postural ICP changes (mean difference, −0.03 ± 2.7 mmHg). No difference was found between predicted and measured ICP for any tilt angle ( P values, 0.65–0.94). The results support the hypothesis that postural ICP changes are governed by hydrostatic effects in the venous system and IJV collapse. This improved understanding of postural ICP regulation may have important implications for the development of better treatments for neurological and neurosurgical conditions affecting ICP.
Diurnal pattern in skin Na+ and water content is associated with salt-sensitive hypertension in ETB receptor-deficient rats
Authors: Speed Joshua S. , Hyndman Kelly A. , Kasztan Malgorzata , Johnston Jermaine G. , Roth Kaehler J. , Titze Jens M. , Pollock David M.
Published: January 2018

Impairment in the ability of the skin to properly store Na+ nonosmotically (without water) has recently been hypothesized as contributing to salt-sensitive hypertension. Our laboratory has shown that endothelial production of endothelin-1 (ET-1) is crucial to skin Na+ handling. Furthermore, it is well established that loss of endothelin type B receptor (ETB) receptor function impairs Na+ excretion by the kidney. Thus we hypothesized that rats lacking functional ETB receptors (ETB-def) will have a reduced capacity of the skin to store Na+ during chronic high-salt (HS) intake. We observed that ETB-def rats exhibited salt-sensitive hypertension with an approximate doubling in the diurnal amplitude of mean arterial pressure compared with genetic control rats on a HS diet. Two weeks of HS diet significantly increased skin Na+ content relative to water; however, there was no significant difference between control and ETB-def rats. Interestingly, HS intake led to a 19% increase in skin Na+ and 16% increase in water content (relative to dry wt.) during the active phase (zeitgeber time 16) versus inactive phase (zeitgeber time 4, P < 0.05) in ETB-def rats. There was no significant circadian variation in total skin Na+ or water content of control rats fed normal or HS. These data indicate that ETB receptors have little influence on the ability to store Na+ nonosmotically in the skin during long-term HS intake but, rather, appear to regulate diurnal rhythms in skin Na+ content and circadian blood pressure rhythms associated with a HS diet.
Removal of interscapular brown adipose tissue increases aortic stiffness despite normal systemic glucose metabolism in mice
Authors: Grunewald Zachary I. , Winn Nathan C. , Gastecki Michelle L. , Woodford Makenzie L. , Ball James R. , Hansen Sarah A. , Sacks Harold S. , Vieira-Potter Victoria J. , Padilla Jaume
Published: January 2018

Brown adipose tissue (BAT) is considered protective against obesity and related cardiometabolic dysfunction. Indeed, activation of BAT improves glucose homeostasis and attenuates cardiovascular disease development. However, whether a reduction in BAT mass perturbs metabolic function and increases risk for cardiovascular disease remains largely unknown. To address this question, C57BL/6J male mice underwent a sham procedure or surgical bilateral excision of interscapular BAT (iBATx) and were fed a normal chow or a Western diet for 18 wk, creating four groups ( n = 10/group). Mice were housed at 25°C. As expected, the Western diet increased final body weight and adiposity; however, contrary to our hypothesis, iBATx did not potentiate adiposity independent of diet. Furthermore, iBATx did not affect indexes of glycemic control (HbA1c, fasting glucose and insulin, and glucose area under the curve during a glucose tolerance test) and produced minimal-to-no effects on lipid homeostasis. The absence of metabolic disturbances with iBATx was not attributed to regrowth of iBAT or a “browning” or proliferative compensatory response of other BAT depots. Notably, iBATx caused an increase in aortic stiffness in normal chow-fed mice only, which was associated with an increase in aortic uncoupling protein-1. Collectively, we demonstrated that, at 25°C (i.e., limited thermal stress conditions), a substantial reduction in BAT mass via iBATx does not disrupt systemic glucose metabolism, challenging the current dogma that preservation of BAT is obligatory for optimal metabolic function. However, iBATx caused aortic stiffening in lean mice, hence supporting the existence of an interplay between iBAT and aortic stiffness, independent of alterations in glucose homeostasis.
Dynamic changes in nitric oxide synthase expression are involved in seawater acclimation of rainbow troutOncorhynchus mykiss
Authors: Gerber Lucie , Jensen Frank B. , Madsen Steffen S.
Published: January 2018

Recent research has shown that nitric oxide (NO) produced by nitric oxide synthases (NOS) is an inhibitor of ion transporter activity and a modulator of epithelial ion transport in fish, but little is known on changes in the NOS/NO system during osmotic stress. We hypothesized that the NOS/NO system responds to salinity changes as an integrated part of the acclimation process. Expression and localization of nos1/Nos1 and nos2/Nos2 were investigated in gill, kidney, and intestine of freshwater (FW)- and seawater (SW)-transferred trout using quantitative PCR, Western blotting, and immunohistochemistry, along with expressional changes of major ion transporters in the gill. The classical branchial ion transporters showed expected expressional changes upon SW transfer, there among a rapid decrease in Slc26a6 mRNA, coding a branchial Cl−/[Formula: see text] exchanger. There was a major downregulation of nos1/ nos2/Nos2 expression in the gill during SW acclimation. A significant decrease in plasma nitrite supported an overall decreased Nos activity and NO production. In the middle intestine, Nos1 was upregulated during SW acclimation, whereas no changes in nos/Nos expression were observed in the posterior intestine and the kidney. Nos1 was localized along the longitudinal axis of the gill filament, beneath smooth muscle fibers of the intestine wall and in blood vessel walls of the kidney. Nos2 was localized within the epithelium adjacent to the gill filament axis and in hematopoietic tissues of the kidney. We conclude that downregulation of branchial NOS is integrated to the SW acclimation process likely to avoid the inhibitory effects of NO on active ion extrusion.
In vivo three-dimensional photoacoustic imaging of the renal vasculature in preclinical rodent models
Authors: Ogunlade Olumide , Connell John J. , Huang Jennifer L. , Zhang Edward , Lythgoe Mark F. , Long David A. , Beard Paul
Published: January 2018

Noninvasive imaging of the kidney vasculature in preclinical murine models is important for the assessment of renal development, studying diseases and evaluating new therapies but is challenging to achieve using existing imaging modalities. Photoacoustic imaging is a promising new technique that is particularly well suited to visualizing the vasculature and could provide an alternative to existing preclinical imaging methods for studying renal vascular anatomy and function. To investigate this, an all-optical Fabry-Perot-based photoacoustic scanner was used to image the abdominal region of mice. High-resolution three-dimensional, noninvasive, label-free photoacoustic images of the mouse kidney and renal vasculature were acquired in vivo. The scanner was also used to visualize and quantify differences in the vascular architecture of the kidney in vivo due to polycystic kidney disease. This study suggests that photoacoustic imaging could be utilized as a novel preclinical imaging tool for studying the biology of renal disease.
Hyperfiltration, urinary albumin excretion, and ambulatory blood pressure in adolescents with Type 1 diabetes mellitus
Authors: Lovshin Julie A. , Škrtić Marko , Bjornstad Petter , Moineddin Rahim , Daneman Denis , Dunger David , Reich Heather N. , Mahmud Farid , Scholey James , Cherney David Z. I. , Sochett Etienne
Published: January 2018

Adolescents with Type 1 diabetes mellitus (T1DM) are at risk for hyperfiltration and elevated urinary albumin-to-creatinine ratio (ACR), which are early indicators of diabetic nephropathy. Adolescents with T1DM also develop early changes in blood pressure, cardiovascular structure, and function. Our aims were to define the relationships between hyperfiltration, ACR, and 24-h ambulatory blood pressure over time in adolescents with T1DM. Normotensive, normoalbuminuric adolescents ( n = 98) with T1DM underwent baseline and 2-yr 24-h ambulatory blood pressure monitoring, glomerular filtration rate (eGFR) estimated by cystatin C (Larsson equation), and ACR measurements. Linear regression models adjusted for diabetes duration, sex, and HbA1c were used to determine associations. Hyperfiltration (eGFR ≥ 133 ml/min) was present in 31% at baseline and 21% at 2-yr follow-up. Hyperfiltration was associated with greater odds of rapid GFR decline (>3 ml·min−1·yr−1) [OR: 5.33, 95%; CI: 1.87–15.17; P = 0.002] over 2 yr. Natural log of ACR at baseline was associated with greater odds of hyperfiltration (OR: 1.71, 95% CI: 1.00–2.92; P = 0.049) and 2-yr follow-up (OR: 2.14, 95%; CI: 1.09–4.19; P = 0.03). One SD increase in eGFR, but not ln ACR, at 2-yr follow-up conferred greater odds of nighttime nondipping pattern (OR: 1.96, 95% CI: 1.06–3.63; P = 0.03). Hyperfiltration was prevalent at baseline and at 2-yr follow-up, predicted rapid decline in GFR, and was related to ACR. Elevated GFR at 2-yr follow-up was associated with nighttime nondipping pattern. More work is needed to better understand early relationships between renal hemodynamic and systemic hemodynamic changes in adolescents with T1DM to reduce future cardiorenal complications.