bluuebunny/crossref_metadata_2025 huggingface dataset:
Photocatalytic Protein Damage by Silver Nanoparticles Circumvents Bacterial Stress Response and Multidrug Resistance
Authors: Shi Tianyuan , Wei Qiuxia , Wang Zhen , Zhang Gong , Sun Xuesong , He Qing-Yu
Published: May 2019

Although silver nanoparticles (AgNPs) are well known for their antibacterial properties, the mechanism by which they kill bacterial cells remains a topic of debate. In this study, we uncovered the bactericidal mechanism of AgNPs, which is induced by light. We tested the efficacy of AgNPs against a panel of antimicrobial-resistant pathogens as well as
Escherichia coli
under conditions of light and darkness and revealed that light excited the AgNPs to promote protein aggregation within the bacterial cells. Our report makes a significant contribution to the literature because this mechanism bypasses microbial drug resistance mechanisms, thus presenting a viable option for the treatment of multidrug-resistant bacteria.
What are the barriers and challenges faced by adolescents when searching for sexual health information on the internet? Implications for policy and practice from a qualitative study
Authors: Patterson Susan Patricia , Hilton Shona , Flowers Paul , McDaid Lisa M
Published: May 2019

Objectives

As sexual health information is increasingly presented digitally, and adolescents are increasingly seeking sexual health information on the internet, it is important to explore the challenges presented by this developing source of information provision. This study examined the key barriers and challenges faced by young people when accessing and using sexual health information online.

Methods

A novel qualitative approach was used which combined paired interviews with real-time online activities. A purposive sample of 49 young people aged between 16 and 19 years and diverse in terms of gender, sexuality, religion and socio-demographic background were recruited from areas across Scotland. Data analysis comprised framework analysis of conversational data (including pair interactions), descriptive analysis of observational data, and data integration.

Results

This study highlighted practical and socio-cultural barriers to engagement with online sexual health content. Key practical barriers included difficulty filtering overabundant content; limited awareness of specific, relevant, trusted online sources; difficulties in finding locally relevant information about services; and difficulties in navigating large organisations’ websites. Key socio-cultural barriers included fear of being observed; wariness about engaging with visual and auditory content; concern about unintentionally accessing sexually explicit content; and reticence to access sexual health information on social networking platforms or through smartphone applications. These practical and socio-cultural barriers restricted access to information and influenced searching practices.

Conclusion

This study provides insights into some of the key barriers faced by young people in accessing and engaging with sexual health information and support online. Reducing such challenges is essential. We highlight the need for sexual health information providers and intervention developers to produce online information that is accurate and accessible; to increase awareness of and promote reliable, accessible sources; and to be sensitive to young people’s concerns about ‘being seen’ accessing sexual health information regarding audio-visual content and platform choice.
A molecular approach to identifying the relationship between resource use and availability in Eurasian otters (Lutra lutra)
Authors: Hong Sungwon , Gim Jeong-Soo , Kim Hyo Gyeom , Cowan Phil E. , Joo Gea-Jae
Published: May 2019

In South Korea, the Eurasian otter (Lutra lutra (Linnaeus, 1758)), a semi-aquatic carnivore, is found mainly in lower order streams that tend to have a low abundance of preferred prey fish species. To investigate the relationship between resource use and availability, we used DNA barcoding to identify otter diet items in 24 otter spraints (faeces) from 16 sites along the Nakdong River basin from 4 to 6 June 2014. At these sites fish availability was assessed using scoop nets and casting nets. Fish formed the bulk of otter diet, which included also frogs, mammals, and reptiles. By DNA barcoding (success rate: 72.38%), we identified 79 prey items from 105 bone remains. The diet comprised mostly fish, but frogs, mammals, and reptiles were also identified. The fish fauna and otter diet composition differed significantly. Across the study sites, members of the Cyprinidae dominated in netted samples, but occurred less frequently in otter diet. Because most Cyprinidae are fast swimmers, otters also fed on benthic fishes and frogs, suggesting limited foraging flexibility in otters and specialization on more slowly moving prey.
Chapter 12 A 251 Ma diorite clast from a Maitai Group conglomerate and a
c.
259 Ma microdiorite sill intruding the Productus Creek Group, Southland, New Zealand: note
Authors: Mortimer N. , Turnbull R. E. , Robertson A. H. F. , Campbell H. J.
Published: May 2019

We present the results of U–Pb dating of zircons of two Late Permian igneous rocks from the Dun Mountain–Maitai and Brook Street terranes of New Zealand's South Island. A conglomerate clast of hornblende diorite from the Early–Middle Triassic Stephens Subgroup, Maitai Group, gives an age of 251.1 ± 1.6 Ma. A sample of hypabyssal andesite–microdiorite (Weetwood Formation) that intrudes the Late Permian Productus Creek Group of the Brook Street Terrane gives an age of 258.8 ± 7.9 Ma. The intermediate and subalkaline geochemistry of the two samples is not distinctive of specific tectonic settings, but their ages match plutons of the I-type, subduction-related Longwood Suite of the nearby Median Batholith. Assuming that correlation with the Longwood Suite is correct, the Weetwood sample increases the known areal extent of intrusion of the Longwood Suite; and the Stephens Subgroup Formation clast is consistent with a detrital link between Gondwana and the Dun Mountain–Maitai Terrane by the Middle Triassic. However, because of uncertainties regarding the timing of magmatism along other parts of the Gondwana margin, the data in this paper do not establish any specific provenance links.
Chapter 4 Geological development and regional significance of an oceanic magmatic arc and its sedimentary cover: Permian Brook Street Terrane, South Island, New Zealand
Authors: Robertson Alastair H. F. , Palamakumbura Romesh
Published: May 2019

The
c.
450 km-long Brook Street Terrane (pre-Alpine Fault displacement) sheds light on processes of arc magmatism and related sedimentation. A very thick (up to 15 km) succession accumulated south of the Alpine Fault in the Takitimu Mountains during the Early Permian. Predominant arc-flank talus is intercalated with basic extrusive and intrusive igneous rocks. Volcaniclastic sediments mainly accumulated by mass-flow and turbidity current processes. The sediments were mostly derived from differentiated, arc-core, basaltic–andesitic rocks, contrasting with less evolved arc-flank flows and minor intrusions. Some igneous rocks are mildly enriched, supporting an extensional back-arc setting. After volcanism ended, Middle–Late Permian mixed carbonate–volcaniclastic gravity-flow deposits were derived from a non-exposed carbonate platform. Other volcanogenic successions in the south (Bluff, Riverton) represent smaller eruptive centres. In contrast, north of the Alpine Fault (e.g. Nelson), volcanism began with mostly felsic tuffaceous gravity-flow deposits, followed by extrusion/intrusion of clinopyroxene-rich, primitive magmas, related to arc rifting, and ended with an accumulation of a mixed basic–felsic volcaniclastic forearc apron. Taking account of regional comparisons, the Early Permian arc is interpreted as having formed adjacent to Gondwana (on accreted or trapped oceanic lithosphere), whereas the lithologies north of the Alpine Fault represent contrasting Late Permian continental arc magmatism.
Chapter 11 Geochemistry used to infer source characteristics and provenance of mudrocks of the Permian–Triassic Maitai Group and the associated Patuki Melange, South Island, New Zealand
Authors: Palamakumbura Romesh , Robertson Alastair H. F.
Published: May 2019

Chemical and mineralogical evidence is reported, first for mudrocks from the Mid-Permian–Mid-Triassic Maitai Group and, secondly, for Late Permian(?) mudrocks from the structurally underlying Patuki Melange. Weathering and alteration indices indicate increased source weathering and aluminosilicate input stratigraphically upwards in the Maitai Group. The Maitai Group exhibits an upward change from a relatively enriched continental magmatic arc source (and related country rocks) during the Late Permian, to a relatively depleted continental magmatic arc source (and related country rocks) during the Triassic. The melange mudrocks have a similar provenance to the Late Permian mudrocks of the Maitai Group. The melange mudrocks are, however, generally less altered, probably because of additional, local, ophiolite-related input. Red iron-rich mudrocks accumulated widely in two Triassic Maitai Group formations and also locally in the Patuki Melange. The iron oxide was derived by continental weathering under warm conditions, and then accumulated relatively slowly under oxidizing seafloor conditions. The chemical evidence, as a whole, indicates sources for all of the mudrocks similar to the Median Batholith and associated country rocks, or non-exposed equivalents along the SE Gondwana active continental margin. Accumulation took place during a change from an icehouse to a hothouse world.
Chapter 10 Sedimentary geochemistry used to infer the provenance of Permian–Triassic marine sandstones related to the SE Gondwana active continental margin, South Island, New Zealand
Authors: Robertson Alastair H. F. , Palamakumbura Romesh
Published: May 2019

Major, trace and rare earth element data for sandstones and conglomerates from the Mid-Permian–Mid-Triassic Maitai Group are compared with other tectonostratigraphic units, using discrimination diagrams and comparisons with potential source terranes. Maitai Group sandstones reveal a mainly ophiolitic–oceanic-arc source during the Mid-Permian, followed by a mixed continental margin-arc–terrigenous source during the Late Permian. Latest Permian–Early Triassic sandstones mainly came from little-evolved continental margin-arc extrusives, tending to more evolved (but variable) during the Triassic. Source volcanism of the Murihiku Terrane sandstones was magmatically evolved relative to the Maitai Group generally (except during the Late Triassic). The Maitai Group and Murihiku Terrane are restored as proximal and more distal parts, respectively, of the SE Gondwana forearc basin. The localized Willsher Group shows some Maitai Group affinities. Sandstones in two melanges that formed in an outer forearc–subduction trench setting mainly indicate a mixed terrigenous–continental margin-arc source, similar to the Late Permian Maitai Group. The Caples Terrane, a Triassic accretionary prism, received detritus from little-evolved, to evolved continental margin-arc volcanics and terrigenous sources. Much of the arc-related material in all units is compatible with derivation from the latest Permian–Triassic Median Batholith, or a lateral equivalent along the SE Gondwana active margin.
Chapter 13 Permian–Triassic felsic tuffs in South Island, New Zealand: significance for oceanic and active continental margin subduction
Authors: Robertson Alastair H. F. , Palamakumbura Romesh , Campbell Hamish J.
Published: May 2019

Felsic tuffs play an important role in the Permian–Triassic geology of the Eastern Province in South Island. In the Brook Street Terrane, primary felsic tuff is minor in the south (e.g. Takitimu Mountains) but abundant in the north (Grampian Formation, Nelson area). Felsic fallout tuff dominates one interval of the Maitai Group (Early Triassic Kiwi Burn Formation), south of the Alpine Fault, but is otherwise mainly redeposited by gravity flows. The Murihiku Terrane is characterized by two main intervals of felsic fallout tuff, the Middle Triassic Gavenwood Tuffs and the Late Triassic Bare Hill Tuff Zone, south of the Alpine Fault (e.g. Hokonui Hills and south Otago coast). Counterparts north of the Alpine Fault (Richmond Group) are mainly reworked, with terrigenous admixtures. Tuffaceous sediments are also abundant in the late Middle–early Late Triassic Willsher Group (south Otago coast). Based on combined field, petrographical, semi-quantitative X-ray diffraction (XRD) and chemical evidence, the felsic tuffs of the Brook Street Terrane in the south are interpreted as small-scale eruptions of fractionated oceanic-arc-type magmas. In contrast, the Triassic felsic tuffs of the Murihiku Terrane, Willsher Group and Maitai Group erupted violently and episodically in proximal to distal segments of the SE Gondwana continental margin.
Chapter 3 Biostratigraphic age review of New Zealand's Permian–Triassic central terranes
Authors: Campbell Hamish J.
Published: May 2019

This contribution considers the fossil content of the three Eastern Province ‘central’ terranes discussed within this Memoir, namely the Brook Street Terrane, the Dun Mountain–Maitai Terrane and the Murihiku Terrane, and reviews the evidence and/or arguments for the current interpretation of their age ranges as determined from fossils. It also briefly considers the Permian–Triassic record of the Western Province. There has been limited new palaeontological discovery in the past few decades but there has been significant new taxonomic and biostratigraphic analysis of New Zealand Permian faunas in light of new research in eastern Australia. This enables refinement of age correlations and greater confidence in the age significance of the New Zealand Permian record.
Chapter 15 Construction of a Paleozoic–Mesozoic accretionary orogen along the active continental margin of SE Gondwana (South Island, New Zealand): summary and overview
Authors: Robertson Alastair H. F. , Campbell Hamish J. , Johnston Mike R. , Palamakumbra Romesh
Published: May 2019

The Western Province is a fragment of the
c.
500 Ma SE Gondwana active continental margin. The Eastern Province is a terrane assemblage, which is partly stitched by the Median Batholith. Fragments of the batholith are preserved in the adjacent Drumduan and Brook Street terranes. Permian arc magmatism of the Brook Street Terrane involved both oceanic and continental margin settings. The Permian (
c.
285–275 Ma) supra-subduction zone Dun Mountain ophiolite records subduction initiation and subsequent oceanic-arc magmatism. The Permian Patuki and Croisilles melanges represent detachment of the ophiolitic forearc and trench–seamount accretion. The Murihiku Terrane, a proximal continental margin forearc basin, received detritus from the Median Batholith (or equivalent). The south coast, Early–Late Triassic Willsher Group is another proximal forearc basin unit. The sediments of the Dun Mountain–Maitai Terrane (Maitai basin) represent a distal segment of a continental margin forearc basin. The Caples Terrane is a mainly Triassic trench accretionary complex, dominantly sourced from a continental margin arc, similar to the Median Batholith. The outboard (older) Torlesse and Waipapa terranes are composite subduction complexes. Successively more outboard terranes may restore farther north along the SE Gondwana continental margin. Subduction and terrane assembly were terminated by collision (at
c.
100 Ma), followed by rifting of the Tasman Sea Basin.
Hydraulic evaluation of a dewatering scheme in shallow aquifers in Kuwait
Authors: Aliewi Amjad , Al-Qallaf Habib , Rashid Tariq , Al-Odwani Ali
Published: May 2019

In heavily populated residential areas lacking adequate subsurface drainage, leakage from urban water supplies and wastewater discharge causes groundwater levels in underlying shallow aquifers to rise. This may have serious consequences for the stability of building foundations, roads and natural landforms. This paper evaluates the performance of a dewatering scheme comprising of 15 vertical wells in two residential areas in Kuwait. The hydraulic effectiveness is evaluated from pumping tests and preliminary numerical modelling. The results show that the scheme can keep the water table at the desired levels over a limited area. The maximum predicted nodal drawdowns after one year of pumping at 16 835 m
3
d
–1
were 4.2 and 5.24 m in the two areas. Further investigations are proposed with the objective of optimizing pumping rates.
The Social Structure of Time: Emerging Trends and New Directions
Authors: Cornwell Benjamin , Gershuny Jonathan , Sullivan Oriel
Published: May 2019

Research on time use has seen several major developments in recent years. These include the adoption of exciting new technologies (e.g., smartphones, wearable Global Positioning System devices) that track behavior in real time, as well as a growing international database—the Multinational Time Use Study—that has surpassed one million days’ worth of harmonized time-diary data. These developments are transforming our understanding of the social patterning of everyday behavior. This article provides updates about this area of work, including recent findings regarding foundational sociological issues such as trends in gendered divisions of household labor and over-time, cross-national aggregate estimates of time spent on paid work and leisure. We also highlight new approaches to the study of time use. This includes an overview of advances in the collection and analysis of time-stamped behavioral data, as well as a discussion of methodological advances in the analysis of the temporal sequential structure of everyday activities.
miR-125a-5p: a novel regulator of SLC26A6 expression in intestinal epithelial cells
Authors: Anbazhagan Arivarasu N. , Priyamvada Shubha , Borthakur Alip , Saksena Seema , Gill Ravinder K. , Alrefai Waddah A. , Dudeja Pradeep K.
Published: May 2019

Putative anion transporter 1 (PAT1, SLC26A6), an intestinal epithelial Cl−/[Formula: see text] exchanger, also plays a key role in oxalate homeostasis via mediating intestinal oxalate secretion. Indeed, Slc26a6-null mice showed defect in intestinal oxalate secretion and high incidence of kidney stones. Recent emergence of PAT-1 as a novel therapeutic target for nephrolithiasis warrants detailed understanding of the mechanisms of PAT-1 regulation in health and disease. Therefore, we investigated the regulation of PAT-1 expression by microRNAs (miRNA), as they have been shown to play key role in modulating expression of other ion transporters. In silico analysis of PAT-1 3′-untranslated region (UTR) revealed potential binding sites for several miRNAs, suggesting the role of miRNAs in modulating PAT1 expression. miRNAs showing highest context scores (125a-5p, 339-5p, 423-5p, 485-5p, and 501-3p) were selected as candidates for their effects on the activity of a 263-bp PAT-1 3′-untranslated region (UTR) fragment cloned into pmirGLO vector upstream of luciferase. The 3′-UTR activity was measured by dual luciferase reporter assay in Caco-2, T-84, HT-29, and SK-CO15 cells. Transient transfection of PAT-1 3′-UTR significantly decreased the relative luciferase activity compared with the empty vector suggesting binding of potential miRNA(s) to the PAT-1 3′-UTR. Among all the selected candidates, cotransfection with miRNA mimics 125a-5p and 423-5p further decreased PAT-1 3′-UTR activity. Furthermore, increasing miR-125a-5p abundance via mimic transfection in Caco-2 cells decreased both mRNA and protein levels of PAT-1. Our results demonstrate a novel regulatory mechanism of intestinal PAT-1 expression via miR-125a-5p that could be of therapeutic importance in disorders associated with decreased PAT-1 expression and function.
MicroRNA-140 inhibits skeletal muscle glycolysis and atrophy in endotoxin-induced sepsis in mice via the WNT signaling pathway
Authors: Liu Li , Li Tian-Mei , Liu Xue-Ru , Bai Yi-Ping , Li Jie , Tang Ni , Wang Xiao-Bin
Published: May 2019

Sepsis is a systemic inflammatory response syndrome resulting from infection. This study aimed at exploring the role of microRNA-140 (miR-140) in septic mice. Wnt family member 11 (WNT11) was verified to be a target gene of miR-140 after bioinformatic prediction and dual luciferase reporter gene assay. Importantly, miR-140 negatively regulated WNT11. We initially induced the model of sepsis by endotoxin, and then ectopic expression and knockdown experiments were performed to explore the functional role of miR-140 in sepsis. Additionally, cross-sectional areas of muscle fiber, lactic acid production, 3-methylhistidine (3-MH) and tyrosine (Tyr) production in extensor digitorium longus (EDL) muscles, and serum levels of inflammatory factors were examined. The effect of miR-140 on the expression of WNT signaling pathway-related and apoptosis-related factors in skeletal muscle tissue was determined. The experimental results indicated that upregulated miR-140 or silenced WNT11 increased cross-sectional areas of muscle fiber while decreasing lactic acid production, skeletal muscle cell apoptosis [corresponding to downregulated B cell lymphoma 2 (Bcl-2)-associated X protein (Bax) and caspase-3 and upregulated Bcl-2], and the proteolytic rate of Tyr and 3-MH. Also, overexpressed miR-140 or silenced WNT11 reduced inflammation as reflected by decreased serum levels of IL-6, IL-10, and TNF-α. Furthermore, overexpression of miR-140 was shown to suppress the activation of the WNT signaling pathway, accompanied by decreased expression of WNT11, β-catenin, and GSK-3β. Taken together, upregulation of miR-140 could potentially inhibit skeletal muscle lactate release, an indirect measure of glycolysis, and atrophy in septic mice through suppressing the WNT signaling pathway via inhibiting WNT11 expression.
β3-Adrenoceptor agonists inhibit purinergic receptor-mediated contractions of the murine detrusor
Authors: Fong Zhihui , Griffin Caoimhín S. , Hollywood Mark A. , Thornbury Keith D. , Sergeant Gerard P.
Published: May 2019

β3-Adrenoceptor (β3-AR) agonists are used to treat overactive bladder syndrome; however, their mechanism of action has not been determined. The aims of this study were to compare the effects of β3-AR agonists on cholinergic versus purinergic receptor-mediated contractions of the detrusor and to examine the mechanisms underlying inhibition of the purinergic responses by β3-AR agonists. Isometric tension recordings were made from strips of murine detrusor and whole cell current recordings were made from freshly isolated detrusor myocytes using the patch-clamp technique. Transcriptional expression of exchange protein directly activated by cAMP (EPAC) subtypes in detrusor strips was assessed using RT-PCR and real-time quantitative PCR. The β3-AR agonists BRL37344 and CL316243 (100 nM) inhibited cholinergic nerve-mediated contractions of the detrusor by 19 and 23%, respectively, but did not reduce contractions induced by the cholinergic agonist carbachol (300 nM). In contrast, BRL37344 and CL316243 inhibited purinergic nerve-mediated responses by 55 and 56%, respectively, and decreased the amplitude of contractions induced by the P2X receptor agonist α,β-methylene ATP by 40 and 45%, respectively. The adenylate cyclase activator forskolin inhibited purinergic responses, and these effects were mimicked by a combination of the PKA activator N6-monobutyryl-cAMP and the EPAC activator 8-pCPT-2′- O-methyl-cAMP-AM (007-AM). Application of ATP (1 μM) evoked reproducible P2X currents in isolated detrusor myocytes voltage-clamped at −60 mV. These responses were reduced in amplitude in the presence of BRL37344 and also by 007-AM. This study demonstrates that β3-AR agonists reduce postjunctional purinergic responses in the detrusor via a pathway involving activation of the cAMP effector EPAC.
Caveolin-1 scaffolding domain peptide prevents hyperoxia-induced airway remodeling in a neonatal mouse model
Authors: Vogel Elizabeth R. , Manlove Logan J. , Kuipers Ine , Thompson Michael A. , Fang Yun-Hua , Freeman Michelle R. , Britt Rodney D. , Faksh Arij , Yang Binxia , Prakash Y. S. , Pabelick Christina M.
Published: May 2019

Reactive airway diseases are significant sources of pulmonary morbidity in neonatal and pediatric patients. Supplemental oxygen exposure in premature infants contributes to airway diseases such as asthma and promotes development of airway remodeling, characterized by increased airway smooth muscle (ASM) mass and extracellular matrix (ECM) deposition. Decreased plasma membrane caveolin-1 (CAV1) expression has been implicated in airway disease and may contribute to airway remodeling and hyperreactivity. Here, we investigated the impact of clinically relevant moderate hyperoxia (50% O2) on airway remodeling and caveolar protein expression in a neonatal mouse model. Within 12 h of birth, litters of B6129SF2J mice were randomized to room air (RA) or 50% hyperoxia exposure for 7 days with or without caveolin-1 scaffolding domain peptide (CSD; caveolin-1 mimic; 10 µl, 0.25 mM daily via intraperitoneal injection) followed by 14 days of recovery in normoxia. Moderate hyperoxia significantly increased airway reactivity and decreased pulmonary compliance at 3 wk. Histologic assessment demonstrated airway wall thickening and increased ASM mass following hyperoxia. RNA from isolated ASM demonstrated significant decreases in CAV1 and cavin-1 in hyperoxia-exposed animals while cavin-3 was increased. Supplementation with intraperitoneal CSD mitigated both the physiologic and histologic changes observed with hyperoxia. Overall, these data show that moderate hyperoxia is detrimental to developing airway and may predispose to airway reactivity and remodeling. Loss of CAV1 is one mechanism through which hyperoxia produces these deleterious effects. Supplementation of CAV1 using CSD or similar analogs may represent a new therapeutic avenue for blunting hyperoxia-induced pulmonary damage in neonates.
Flow cytometric analysis of the leukocyte landscape during bleomycin-induced lung injury and fibrosis in the rat
Authors: Kloth Christina , Gruben Nele , Ochs Matthias , Knudsen Lars , Lopez-Rodriguez Elena
Published: May 2019

Bleomycin-induced lung injury and fibrosis is a well-described model to investigate lung inflammatory and remodeling mechanisms. Rat models are clinically relevant and are also widely used, but rat bronchoalveolar lavage (BAL) cells are not fully characterized with flow cytometry due to the limited availability of antibodies for this species. We optimized a comprehensive time-dependent flow cytometric analysis of cells after bleomycin challenge, confirming previous studies in other species and correlating them to histological staining, cytokine profiling, and collagen accumulation analysis in rat lungs. For this purpose, we describe a novel panel of rat surface markers and a strategy to identify and follow BAL cells over time. By combining surface markers in rat alveolar cells (CD45+), granulocytes and other myeloid cells, monocytes and macrophages can be identified by the expression of CD11b/c. Moreover, different activation states of macrophages (CD163+) can be observed: steady state (CD86−MHC-IIlow), activation during inflammation (CD86+,MHC-IIhigh), activation during remodeling (CD86+MHC-IIlow), and a population of newly recruited monocytes (CD163−α-granulocyte−). Hydroxyproline measured as marker of collagen content in lung tissue showed positive correlation with the reparative phase (CD163−cells and tissue inhibitor of metalloproteinases (TIMP) and IL-10 increase). In conclusion, after a very early granulocytic recruitment, inflammation in rat lungs is observed by activated macrophages, and high release of IL-6 and fibrotic remodeling is characterized by recovery of the macrophage population together with TIMP, IL-10, and IL-18 production. Recruited monocytes and a second peak of granulocytes appear in the transitioning phase, correlating with immunostaining of arginase-1 in the tissue, revealing the importance of events leading the changes from injury to aberrant repair.
Role of fibroblast growth factor 23 and klotho cross talk in idiopathic pulmonary fibrosis
Authors: Barnes Jarrod W. , Duncan Dawn , Helton Scott , Hutcheson Samuel , Kurundkar Deepali , Logsdon Naomi J. , Locy Morgan , Garth Jaleesa , Denson Rebecca , Farver Carol , Vo Hai T. , King Gwendalyn , Kentrup Dominik , Faul Christian , Kulkarni Tejaswini , De Andrade Joao A. , Yu Zhihong , Matalon Sadis , Thannickal Victor J. , Krick Stefanie
Published: May 2019

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial pneumonia that mainly affects the elderly. Several reports have demonstrated that aging is involved in the underlying pathogenic mechanisms of IPF. α-Klotho (KL) has been well characterized as an “age-suppressing” hormone and can provide protection against cellular senescence and oxidative stress. In this study, KL levels were assessed in human plasma and primary lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF-FB) and in lung tissue from mice exposed to bleomycin, which showed significant downregulation when compared with controls. Conversely, transgenic mice overexpressing KL were protected against bleomycin-induced lung fibrosis. Treatment of human lung fibroblasts with recombinant KL alone was not sufficient to inhibit transforming growth factor-β (TGF-β)-induced collagen deposition and inflammatory marker expression. Interestingly, fibroblast growth factor 23 (FGF23), a proinflammatory circulating protein for which KL is a coreceptor, was upregulated in IPF and bleomycin lungs. To our surprise, FGF23 and KL coadministration led to a significant reduction in fibrosis and inflammation in IPF-FB; FGF23 administration alone or in combination with KL stimulated KL upregulation. We conclude that in IPF downregulation of KL may contribute to fibrosis and inflammation and FGF23 may act as a compensatory antifibrotic and anti-inflammatory mediator via inhibition of TGF-β signaling. Upon restoration of KL levels, the combination of FGF23 and KL leads to resolution of inflammation and fibrosis. Altogether, these data provide novel insight into the FGF23/KL axis and its antifibrotic/anti-inflammatory properties, which opens new avenues for potential therapies in aging-related diseases like IPF.
Maternal high-fat diet alters lung development and function in the offspring
Authors: Heyob Kathryn M. , Mieth Saya , Sugar Sophia S. , Graf Amanda E. , Lallier Scott W. , Britt Rodney D. , Rogers Lynette K.
Published: May 2019

The effects of maternal obesity on lung development have been recognized, and speculation is that these diseases are not simply because of accelerated pulmonary decline with aging but with a failure to achieve optimal lung development during early life. These studies tested the hypothesis that maternal obesity alters signaling pathways during the course of lung development that may affect life-long pulmonary health. Adult female mice were fed 60% fat [high-fat diet (HFD)] or 10% fat [control diet (CD)] for 8 wk before mating and through weaning. Pup lung tissues were collected at postnatal days ( PN) 7, 21, and 90 (after receiving HFD or CD as adults). At PN7, body weights from HFD were greater than CD but lung weight-to-body weight ratios were lower. In lung tissues, NFκB-mediated inflammation was greater in HFD pups at PN21 and phospho-/total STAT3, phospho-/total VEGF receptor 2, and total AKT protein levels were lower with maternal HFD and protein tyrosine phosphatase B1 levels were increased. Decreased platelet endothelial cell adhesion molecule levels were observed at PN21 and at PN90 in the pups exposed to maternal HFD. Morphometry indicated that the pups exposed to maternal or adult HFD had fewer alveoli, and the effect was additive. Decreases in pulmonary resistance, elastance, and compliance were observed because of adult HFD diet and decreases in airway resistance and increases in inspiratory capacity because of maternal HFD. In conclusion, maternal HFD disrupts signaling pathways in the early developing lung and may contribute to deficiencies in lung function and increased susceptibility in adults.
Extrinsic acidosis suppresses glycolysis and migration while increasing network formation in pulmonary microvascular endothelial cells
Authors: Lee Ji Young , Onanyan Mher , Garrison Ian , White Roderica , Crook Maura , Alexeyev Mikhail F. , Kozhukhar Natalya , Pastukh Viktoriya , Swenson Erik R. , Supuran Claudiu T. , Stevens Troy
Published: May 2019

Acidosis is common among critically ill patients, but current approaches to correct pH do not improve disease outcomes. During systemic acidosis, cells are either passively exposed to extracellular acidosis that other cells have generated (extrinsic acidosis) or they are exposed to acid that they generate and export into the extracellular space (intrinsic acidosis). Although endothelial repair following intrinsic acidosis has been studied, the impact of extrinsic acidosis on migration and angiogenesis is unclear. We hypothesized that extrinsic acidosis inhibits metabolism and migration but promotes capillary-like network formation in pulmonary microvascular endothelial cells (PMVECs). Extrinsic acidosis was modeled by titrating media pH. Two types of intrinsic acidosis were compared, including increasing cellular metabolism by chemically inhibiting carbonic anhydrases (CAs) IX and XII (SLC-0111) and with hypoxia. PMVECs maintained baseline intracellular pH for 24 h with both extrinsic and intrinsic acidosis. Whole cell CA IX protein expression was decreased by extrinsic acidosis but not affected by hypoxia. When extracellular pH was equally acidic, extrinsic acidosis suppressed glycolysis, whereas intrinsic acidosis did not. Extrinsic acidosis suppressed migration, but increased Matrigel network master junction and total segment length. CRISPR-Cas9 CA IX knockout PMVECs revealed an independent role of CA IX in promoting glycolysis, as loss of CA IX alone was accompanied by decreased hexokinase I and pyruvate dehydrogenase E1α expression and decreasing migration. 2-deoxy-d-glucose had no effect on migration but profoundly inhibited network formation and increased N-cadherin expression. Thus, we report that while extrinsic acidosis suppresses endothelial glycolysis and migration, it promotes network formation.
Unaltered V̇o2 kinetics despite greater muscle oxygenation during heavy-intensity two-legged knee extension versus cycle exercise in humans
Authors: Koga Shunsaku , Okushima Dai , Poole David C. , Rossiter Harry B. , Kondo Narihiko , Barstow Thomas J.
Published: May 2019

Relative perfusion of active muscles is greater during knee extension ergometry (KE) than cycle ergometry (CE). This provides the opportunity to investigate the effects of increased O2 delivery (Q̇o2) on deoxygenation heterogeneity among quadriceps muscles and pulmonary oxygen uptake (V̇o2) kinetics. Using time-resolved near-infrared spectroscopy, we hypothesized that compared with CE the superficial vastus lateralis (VL), superficial rectus femoris, and deep VL in KE would have 1) a smaller amplitude of the exercise-induced increase in deoxy[Hb + Mb] (related to the balance between V̇o2 and Q̇o2); 2) a greater amplitude of total[Hb + Mb] (related to the diffusive O2 conductance); 3) a greater homogeneity of regional muscle deoxy[Hb + Mb]; and 4) no difference in pulmonary V̇o2 kinetics. Eight participants performed square-wave KE and CE exercise from 20 W to heavy work rates. Deoxy[Hb + Mb] amplitude was less for all muscle regions in KE ( P < 0.05: superficial, KE 17–24 vs. CE 19–40; deep, KE 19 vs. CE 26 μM). Furthermore, the amplitude of total[Hb + Mb] was greater for KE than CE at all muscle sites ( P < 0.05: superficial, KE, 7–21 vs. CE, 1–16; deep, KE, 11 vs. CE, −3 μM). Although the amplitude and heterogeneity of deoxy[Hb + Mb] were significantly lower in KE than CE during the first minute of exercise, the pulmonary V̇o2 kinetics was not different for KE and CE. These data show that the microvascular Q̇o2 to V̇o2 ratio, and thus tissue oxygenation, was greater in KE than CE. This suggests that pulmonary and muscle V̇o2 kinetics in young healthy humans are not limited by Q̇o2 during heavy-intensity cycling.
GHRH-mediated GH release is associated with sympathoactivation and baroreflex resetting: a microneurographic study in healthy humans
Authors: Meusel Moritz , Herrmann Magdalena , Machleidt Felix , Franzen Klaas F. , Krapalis Alexander F. , Sayk Friedhelm
Published: May 2019

Previous research suggested substantial interactions of growth hormone (GH) and sympathetic nervous activity. This cross talk can be presumed both during physiological (e.g., slow-wave sleep) and pathological conditions of GH release. However, microneurographic studies of muscle sympathetic nerve activity (MSNA) and assessment of baroreflex function during acute GH-releasing hormone (GHRH)-mediated GH release were not conducted so far. In a balanced, double-blind crossover design, GHRH or placebo (normal saline) were intravenously administered to 11 healthy male volunteers. MSNA was assessed microneurographically and correlated with blood pressure (BP) and heart rate (HR) at rest before (pre-) and 30–45 (post-I) and 105–120 min (post-II) after respective injections. Additionally, baroreflex function was assessed via graded infusion of vasoactive drugs. GHRH increased GH serum levels as intended. Resting MSNA showed significant net increases of both burst rate and total activity from pre- to post-I and post-II following GHRH injections compared with placebo (ANOVA for treatment and time, burst rate: P = 0.028; total activity: P = 0.045), whereas BP and HR were not altered. ANCOVA revealed that the dependent variable MSNA was not affected by the independent variables mean arterial BP (MAP) or HR (MAP: P = 0.006; HR: P = 0.003). Baroreflex sensitivity at baroreflex challenge was not altered. GHRH-mediated GH release is associated with a significant sympathoactivation at central nervous sites superordinate to the simple baroreflex feedback loop because GH induced a baroreflex resetting without altering baroreflex sensitivity.
A simple method to monitor hepatic gluconeogenesis and triglyceride synthesis following oral sugar tolerance test in obese adolescents
Authors: Carreau Anne-Marie , Jin Eunsook S. , Garcia-Reyes Yesenia , Rahat Haseeb , Nadeau Kristen J. , Malloy Craig R. , Cree-Green Melanie
Published: May 2019

Hepatic energy metabolism is a key element in many metabolic diseases. Hepatic anaplerosis provides carbons for gluconeogenesis (GNG) and triglyceride (TG) synthesis. We aimed to optimize a protocol that measures hepatic anaplerotic contribution for GNG, TG synthesis, and hepatic pentose phosphate pathway (PPP) activity using a single dose of oral [U−13C3]glycerol paired with an oral sugar tolerance test (OSTT) in a population with significant insulin resistance. The OSTT (75 g glucose + 25 g fructose) was administered to eight obese adolescents with polycystic ovarian syndrome (PCOS) followed by ingestion of [U-13C3]glycerol at t = 180 or t = 210 min. 13C-labeling patterns of serum glucose and TG-glycerol were determined by nuclear magnetic resonance. 13C enrichment in plasma TG-glycerol was detectable and stable from 240 to 390 min with the [U-13C3]glycerol drink at t = 180 min(3.65 ± 2.3 to 4.47 ± 1.4%; P > 0.4), but the enrichment was undetectable at 240 min with the glycerol drink at t = 210 min. The relative contribution from anaplerosis was determined at the end of the OSTT [18.5 ±3.4% ( t = 180 min) vs. 16.0 ± 3.5% ( t = 210 min); P = 0.27]. [U-13C3]glycerol was incorporated into GNG 390 min after the OSTT with an enrichment of 7.5–12.5%. Glucose derived from TCA cycle activity was 0.3–1%, and the PPP activity was 2.8–4.7%. In conclusion, it is possible to obtain relative measurements of hepatic anaplerotic contribution to both GNG and TG esterification following an OSTT in a highly insulin-resistant population using a minimally invasive technique. Tracer administration should be timed to allow enough de novo TG esterification and endogenous glucose release after the sugar drink.
Hydrogen peroxide inhibits neurons in the paraventricular nucleus of the hypothalamus via potassium channel activation
Authors: Dantzler Heather A. , Matott Michael P. , Martinez Diana , Kline David D.
Published: May 2019

The paraventricular nucleus (PVN) of the hypothalamus is an important homeostatic and reflex center for neuroendocrine, respiratory, and autonomic regulation, including during hypoxic stressor challenges. Such challenges increase reactive oxygen species (ROS) to modulate synaptic, neuronal, and ion channel activity. Previously, in the nucleus tractus solitarius, another cardiorespiratory nucleus, we showed that the ROS H2O2induced membrane hyperpolarization and reduced action potential discharge via increased K+conductance at the resting potential. Here, we sought to determine the homogeneity of influence and mechanism of action of H2O2on PVN neurons. We recorded PVN neurons in isolation and in an acute slice preparation, which leaves neurons in their semi-intact network. Regardless of preparation, H2O2hyperpolarized PVN neurons and decreased action potential discharge. In the slice preparation, H2O2also decreased spontaneous excitatory postsynaptic current frequency, but not amplitude. To examine potential mechanisms, we investigated the influence of the K+channel blockers Ba2+, Cs+, and glibenclamide on membrane potential, as well as the ionic currents active at resting potential and outward K+currents ( IK) upon depolarization. The H2O2hyperpolarization was blocked by K+channel blockers. H2O2did not alter currents between −50 and −110 mV. However, H2O2induced an outward IKat −50 mV yet, at potentials more positive to 0 mV H2O2, decreased IK. Elevated intracellular antioxidant catalase eliminated H2O2effects. These data indicate that H2O2alters synaptic and neuronal properties of PVN neurons likely via membrane hyperpolarization and alteration of IK, which may ultimately alter cardiorespiratory reflexes.
Cardiac hypertrophy in mice submitted to a swimming protocol: influence of training volume and intensity on myocardial renin-angiotensin system
Authors: Soares Douglas dos Santos , Pinto Graziela Hünning , Lopes Amanda , Caetano Daniel Sturza Lucas , Nascimento Thaiane Gomes , Andrades Michael E. , Clausell Nadine , Rohde Luis E. Paim , Leitão Santiago Alonso Tobar , Biolo Andreia
Published: May 2019

Exercise promotes physiological cardiac hypertrophy and activates the renin-angiotensin system (RAS), which plays an important role in cardiac physiology, both through the classical axis [angiotensin II type 1 receptor (AT1R) activated by angiotensin II (ANG II)] and the alternative axis [proto-oncogene Mas receptor (MASR) activated by angiotensin-(1–7)]. However, very intense exercise could have deleterious effects on the cardiovascular system. We aimed to analyze the cardiac hypertrophy phenotype and the classical and alternative RAS axes in the myocardium of mice submitted to swimming exercises of varying volume and intensity for the development of cardiac hypertrophy. Male Balb/c mice were divided into three groups, sedentary, swimming twice a day without overload (T2), and swimming three times a day with a 2% body weight overload (T3), totaling 6 wk of training. Both training groups developed similar cardiac hypertrophy, but only T3 mice improved their oxidative capacity. We observed that T2 had increased levels of MASR, which was followed by the activation of its main downstream protein AKT; meanwhile, AT1R and its main downstream protein ERK remained unchanged. Furthermore, no change was observed regarding the levels of angiotensin peptides, in either group. In addition, we observed no change in the ratio of expression of the myosin heavy chain β-isoform to that of the α-isoform. Fibrosis was not observed in any of the groups. In conclusion, our results suggest that increasing exercise volume and intensity did not induce a pathological hypertrophy phenotype, but instead improved the oxidative capacity, and this process might have the participation of the RAS alternative axis.
A study of sirolimus and mTOR kinase inhibitor in a hypomorphic Pkd1 mouse model of autosomal dominant polycystic kidney disease
Authors: Holditch Sara J. , Brown Carolyn N. , Atwood Daniel J. , Lombardi Andrew M. , Nguyen Khoa N. , Toll Harrison W. , Hopp Katharina , Edelstein Charles L.
Published: May 2019

Autosomal dominant polycystic kidney disease (PKD) is characterized by cyst formation and growth, which are partially driven by abnormal proliferation of tubular cells. Proproliferative mechanistic target of rapamycin (mTOR) complexes 1 and 2 (mTORC1 and mTORC2) are activated in the kidneys of mice with PKD. Sirolimus indirectly inhibits mTORC1. Novel mTOR kinase inhibitors directly inhibit mTOR kinase, resulting in the inhibition of mTORC1 and mTORC2. The aim of the present study was to determine the effects of sirolimus versus the mTOR kinase inhibitor torin2 on cyst growth and kidney function in the Pkd1 p.R3277C ( Pkd1RC/RC) mouse model, a hypomorphic Pkd1 model orthologous to the human condition, and to determine the effects of sirolimus versus torin2 on mTORC1 and mTORC2 signaling in PKD1−/− cells and in the kidneys of Pkd1RC/RC mice. In vitro, both inhibitors reduced mTORC1 and mTORC2 phosphorylated substrates and negatively impacted cellular metabolic activity, as measured by MTT assay. Pkd1RC/RC mice were treated with sirolimus or torin2 from 50 to 120 days of age. Torin2 was as effective as sirolimus in decreasing cyst growth and improving loss of kidney function. Both sirolimus and torin2 decreased phosphorylated S6 protein, phosphorylated eukaryotic translation initiation factor 4E-binding protein 1, phosphorylated Akt, and proliferation in Pkd1RC/RC kidneys. In conclusion, torin2 and sirolimus were equally effective in decreasing cyst burden and improving kidney function and mediated comparable effects on mTORC1 and mTORC2 signaling and proliferation in the Pkd1RC/RC kidney.
Deficiency of T-type Ca2+ channels Cav3.1 and Cav3.2 has no effect on angiotensin II-induced hypertension but differential effect on plasma aldosterone in mice
Authors: Thuesen Anne D. , Finsen Stine H. , Rasmussen Louise L. , Andersen Ditte C. , Jensen Boye L. , Hansen Pernille B. L.
Published: May 2019

T-type Ca2+ channel Cav3.1 promotes microvessel contraction ex vivo. It was hypothesized that in vivo, functional deletion of Cav3.1, but not Cav3.2, protects mice against angiotensin II (ANG II)-induced hypertension. Mean arterial blood pressure (MAP) and heart rate were measured continuously with chronically indwelling catheters during infusion of ANG II (30 ng·kg−1·min−1, 7 days) in wild-type (WT), Cav3.1−/−, and Cav3.2−/− mice. Plasma aldosterone and renin concentrations were measured by radioimmunoassays. In a separate series, WT mice were infused with ANG II (100 ng·kg−1·min−1) with and without the mineralocorticoid receptor blocker canrenoate. Cav3.1−/− and Cav3.2−/− mice exhibited no baseline difference in MAP compared with WT mice, but day-night variation was blunted in both Cav3.1 and Cav3.2−/− mice. ANG II increased significantly MAP in WT, Cav3.1−/−, and Cav3.2−/− mice with no differences between genotypes. Heart rate was significantly lower in Cav3.1−/− and Cav3.2−/− mice compared with control mice. After ANG II infusion, plasma aldosterone concentration was significantly lower in Cav3.1−/− compared with Cav3.2−/− mice. In response to ANG II, fibrosis was observed in heart sections from both WT and Cav3.1−/− mice and while cardiac atrial natriuretic peptide mRNA was similar, the brain natriuretic peptide mRNA increase was mitigated in Cav3.1−/− mice ANG II at 100 ng/kg yielded elevated pressure and an increased heart weight-to-body weight ratio in WT mice. Cardiac hypertrophy, but not hypertension, was prevented by the mineralocorticoid receptor blocker canrenoate. In conclusion, T-type channels Cav3.1and Cav3.2 do not contribute to baseline blood pressure levels and ANG II-induced hypertension. Cav3.1, but not Cav3.2, contributes to aldosterone secretion. Aldosterone promotes cardiac hypertrophy during hypertension.