bluuebunny/crossref_metadata_2025 huggingface dataset:
The PDK1 Inhibitor Dichloroacetate Controls Cholesterol Homeostasis Through the ERK5/MEF2 Pathway
Authors: Khan Abrar Ul Haq , Allende-Vega Nerea , Gitenay Delphine , Gerbal-Chaloin Sabine , Gondeau Claire , Vo Dang-Nghiem , Belkahla Sana , Orecchioni Stefania , Talarico Giovanna , Bertolini Francesco , Bozic Milica , Valdivielso Jose M. , Bejjani Fabienne , Jariel Isabelle , Lopez-Mejia Isabel C. , Fajas Lluis , Lecellier Charles-Henri , Hernandez Javier , Daujat Martine , Villalba Martin
Published: August 2017

Controlling cholesterol levels is a major challenge in human health, since hypercholesterolemia can lead to serious cardiovascular disease. Drugs that target carbohydrate metabolism can also modify lipid metabolism and hence cholesterol plasma levels. In this sense, dichloroacetate (DCA), a pyruvate dehydrogenase kinase (PDK) inhibitor, augments usage of the glycolysis-produced pyruvate in the mitochondria increasing oxidative phosphorylation (OXPHOS). In several animal models, DCA decreases plasma cholesterol and triglycerides. Thus, DCA was used in the 70 s to treat diabetes mellitus, hyperlipoproteinemia and hypercholesterolemia with satisfactory results. However, the mechanism of action remained unknown and we describe it here. DCA increases LDLR mRNA and protein levels as well as LDL intake in several cell lines, primary human hepatocytes and two different mouse models. This effect is mediated by transcriptional activation as evidenced by H3 acetylation on lysine 27 on the LDLR promoter. DCA induces expression of the MAPK ERK5 that turns on the transcription factor MEF2. Inhibition of this ERK5/MEF2 pathway by genetic or pharmacological means decreases LDLR expression and LDL intake. In summary, our results indicate that DCA, by inducing OXPHOS, promotes ERK5/MEF2 activation leading to LDLR expression. The ERK5/MEF2 pathway offers an interesting pharmacological target for drug development.
MAP kinase-interacting serine/threonine kinase 2 promotes proliferation, metastasis, and predicts poor prognosis in non-small cell lung cancer
Authors: Guo Zhihua , Peng Guilin , Li Ermao , Xi Shaoyan , Zhang Yu , Li Yong , Lin Xiaodong , Li Guangqiu , Wu Qinian , He Jianxing
Published: August 2017

We hypothesized that MAP kinase-interacting serine/threonine kinase 2 (MNK2) may contribute to non-small cell lung cancer (NSCLC) development, and serve as a new therapeutic target. Immunohistochemical staining evaluated the correlation between MNK2 expression and clinicopathological features in 367 NSCLC cancer tissues. We determined the effects of MNK2 silencing in NSCLC cell lines in vitro and in vivo. RT-PCR and western blotting was used to examine the impact of MNK2 on ERK and AKT pathways. MNK2 was overexpressed in NSCLC cell lines and tumor tissues. Patients with MNK2 overexpression had lower OS rates (P < 0.001). High expression of MNK2 was correlated with lymph node metastasis (P = 0.008). MNK2 functioned as an independent prognostic factor for poor survival in patients with NSCLC (P = 0.003). MNK2 down-regulation inhibited proliferation, migration and invasion in vitro (P < 0.001), and reduced tumor growth and invasion in nude mice (P < 0.05). MNK2 enhanced phosphorylation of eIF4E, a downstream target of ERK and AKT pathways, which promoted NSCLC proliferation and invasion. We conclude that MNK2 overexpression in NSCLC is associated with proliferation, migration, invasion, and lower survival rates in patients via the phosphorylated eIF4E-mediated signaling pathway.
Carbonyl reductase 1 catalyzes 20β-reduction of glucocorticoids, modulating receptor activation and metabolic complications of obesity
Authors: Morgan Ruth A. , Beck Katharina R. , Nixon Mark , Homer Natalie Z. M. , Crawford Andrew A. , Melchers Diana , Houtman René , Meijer Onno C. , Stomby Andreas , Anderson Anna J. , Upreti Rita , Stimson Roland H. , Olsson Tommy , Michoel Tom , Cohain Ariella , Ruusalepp Arno , Schadt Eric E. , Björkegren Johan L. M. , Andrew Ruth , Kenyon Christopher J. , Hadoke Patrick W. F. , Odermatt Alex , Keen John A. , Walker Brian R.
Published: August 2017

Carbonyl Reductase 1 (CBR1) is a ubiquitously expressed cytosolic enzyme important in exogenous drug metabolism but the physiological function of which is unknown. Here, we describe a role for CBR1 in metabolism of glucocorticoids. CBR1 catalyzes the NADPH- dependent production of 20β-dihydrocortisol (20β-DHF) from cortisol. CBR1 provides the major route of cortisol metabolism in horses and is up-regulated in adipose tissue in obesity in horses, humans and mice. We demonstrate that 20β-DHF is a weak endogenous agonist of the human glucocorticoid receptor (GR). Pharmacological inhibition of CBR1 in diet-induced obesity in mice results in more marked glucose intolerance with evidence for enhanced hepatic GR signaling. These findings suggest that CBR1 generating 20β-dihydrocortisol is a novel pathway modulating GR activation and providing enzymatic protection against excessive GR activation in obesity.
Mild intracellular acidification by dexamethasone attenuates mitochondrial dysfunction in a human inflammatory proximal tubule epithelial cell model
Authors: Schirris T. J. J. , Jansen J. , Mihajlovic M. , van den Heuvel L. P. , Masereeuw R. , Russel F. G. M.
Published: August 2017

Septic acute kidney injury (AKI) associates with poor survival rates and often requires renal replacement therapy. Glucocorticoids may pose renal protective effects in sepsis via stimulation of mitochondrial function. Therefore, we studied the mitochondrial effects of dexamethasone in an experimental inflammatory proximal tubule epithelial cell model. Treatment of human proximal tubule epithelial cells with lipopolysaccharide (LPS) closely resembles pathophysiological processes during endotoxaemia, and led to increased cytokine excretion rates and cellular reactive oxygen species levels, combined with a reduced mitochondrial membrane potential and respiratory capacity. These effects were attenuated by dexamethasone. Dexamethasone specifically increased the expression and activity of mitochondrial complex V (CV), which could not be explained by an increase in mitochondrial mass. Finally, we demonstrated that dexamethasone acidified the intracellular milieu and consequently reversed LPS-induced alkalisation, leading to restoration of the mitochondrial function. This acidification also provides an explanation for the increase in CV expression, which is expected to compensate for the inhibitory effect of the acidified environment on this complex. Besides the mechanistic insights into the beneficial effects of dexamethasone during renal cellular inflammation, our work also supports a key role for mitochondria in this process and, hence, provides novel therapeutic avenues for the treatment of AKI.
Lactoferrin-derived Peptides Active towards Influenza: Identification of Three Potent Tetrapeptide Inhibitors
Authors: Scala Maria Carmina , Sala Marina , Pietrantoni Agostina , Spensiero Antonia , Di Micco Simone , Agamennone Mariangela , Bertamino Alessia , Novellino Ettore , Bifulco Giuseppe , Gomez-Monterrey Isabel M. , Superti Fabiana , Campiglia Pietro
Published: August 2017

Bovine lactoferrin is a biglobular multifunctional iron binding glycoprotein that plays an important role in innate immunity against infections. We have previously demonstrated that selected peptides from bovine lactoferrin C-lobe are able to prevent both Influenza virus hemagglutination and cell infection. To deeper investigate the ability of lactoferrin derived peptides to inhibit Influenza virus infection, in this study we identified new bovine lactoferrin C-lobe derived sequences and corresponding synthetic peptides were synthesized and assayed to check their ability to prevent viral hemagglutination and infection. We identified three tetrapeptides endowed with broad anti-Influenza activity and able to inhibit viral infection in a concentration range femto- to picomolar. Our data indicate that these peptides may constitute a non-toxic tool for potential applications as anti-Influenza therapeutics.
Inhibition of SHIP2 in CD2AP-deficient podocytes ameliorates reactive oxygen species generation but aggravates apoptosis
Authors: Saurus Pauliina , Tolvanen Tuomas A. , Lindfors Sonja , Kuusela Sara , Holthöfer Harry , Lehtonen Eero , Lehtonen Sanna
Published: August 2017

Lack of CD2-associated protein (CD2AP) in mice increases podocyte apoptosis and leads to glomerulosclerosis and renal failure. We showed previously that SHIP2, a negative regulator of the PI3K/AKT signalling pathway, interacts with CD2AP. Here, we found that the expression level and activity of SHIP2 and production of reactive oxygen species (ROS) are increased in cultured CD2AP knockout (CD2AP−/−) mouse podocytes. Oxidative stress was also increased in CD2AP−/− mouse glomeruli in vivo. We found that puromycin aminonucleoside (PA), known to increase ROS production and apoptosis, increases SHIP2 activity and reduces CD2AP expression in cultured human podocytes. PDK1 and CDK2, central regulators of AKT, were downregulated in CD2AP−/− or PA-treated podocytes. Downregulation of PDK1 and CDK2, ROS generation and apoptosis were prevented by CD2AP overexpression in both models. Notably, inhibition of SHIP2 activity with a small molecule inhibitor AS1949490 ameliorated ROS production in CD2AP−/− podocytes, but, surprisingly, further reduced PDK1 expression and aggravated apoptosis. AKT- and ERK-mediated signalling was diminished and remained reduced after AS1949490 treatment in the absence of CD2AP. The data suggest that inhibition of the catalytic activity of SHIP2 is beneficial in reducing oxidative stress, but leads to deleterious increase in apoptosis in podocytes with reduced expression of CD2AP.
Effects of biochar, waste water irrigation and fertilization on soil properties in West African urban agriculture
Authors: Häring Volker , Manka’abusi Delphine , Akoto-Danso Edmund K. , Werner Steffen , Atiah Kofi , Steiner Christoph , Lompo Désiré J. P. , Adiku Samuel , Buerkert Andreas , Marschner Bernd
Published: August 2017

In large areas of sub-Saharan Africa crop production must cope with low soil fertility. To increase soil fertility, the application of biochar (charred biomass) has been suggested. In urban areas, untreated waste water is widely used for irrigation because it is a nutrient-rich year-round water source. Uncertainty exists regarding the interactions between soil properties, biochar, waste water and fertilization over time. The aims of this study were to determine these interactions in two typical sandy, soil organic carbon (SOC) and nutrient depleted soils under urban vegetable production in Tamale (Ghana) and Ouagadougou (Burkina Faso) over two years. The addition of biochar at 2 kg m−2 made from rice husks and corn cobs initially doubled SOC stocks but SOC losses of 35% occurred thereafter. Both biochar types had no effect on soil pH, phosphorous availability and effective cation exchange capacity (CEC) but rice husk biochar retained nitrogen (N). Irrigation with domestic waste water increased soil pH and exchangeable sodium over time. Inorganic fertilization alone acidified soils, increased available phosphorous and decreased base saturation. Organic fertilization increased SOC, N and CEC. The results from both locations demonstrate that the effects of biochar and waste water were less pronounced than reported elsewhere.
Caveolin-1 Protects Retinal Ganglion Cells against Acute Ocular Hypertension Injury via Modulating Microglial Phenotypes and Distribution and Activating AKT pathway
Authors: Zhang Liwei , Xu Jiazhou , Liu Ran , Chen Wei , Chen Qishan , Hu Wenjie , Zhou Lan , Zhang Ruting , Xu Hongping , Lin Dongyue , Li Xuri , Tang Zhongshu
Published: August 2017

Glaucoma, a group of eye diseases, causes gradual loss of retinal ganglion cells (RGCs) and ultimately results in irreversible blindness. Studies of the underlying mechanisms of glaucoma and clinical trial are far from satisfactory. Results from a genome-wide association study have suggested that the CAV1/CAV2 locus is associated with glaucoma, but this association and its potential underlying mechanisms need to be confirmed and further explored. Here, we studied the function of caveolin-1 (Cav1) in an acute ocular hypertension glaucoma model. Cav1 deficiency caused an aggregated lesion in the retina. In addition, treatment with cavtratin, a membrane permeable Cav1 scaffolding domain peptide, enhanced RGC survival. After cavtratin treatment, microglial numbers decreased significantly, and the majority of them migrated from the inner retinal layer to the outer retinal layers. Furthermore, cavtratin promoted a change in the microglia phenotype from the neurotoxic pro-inflammatory M1 to the neuroprotective anti-inflammatory M2. In a molecular mechanism experiment, we found that cavtratin activated the phosphorylation of both AKT and PTEN in cultured N9 cells. Our data highlights the neuroprotective effect of Cav1 on acute ocular hypertension and suggests that Cav1 may serve as a novel therapeutic target for the treatment of glaucoma. We further propose that cavtratin is a therapeutic candidate for glaucoma clinical trials.
Scatter-plate microscope for lensless microscopy with diffraction limited resolution
Authors: Singh Alok Kumar , Pedrini Giancarlo , Takeda Mitsuo , Osten Wolfgang
Published: August 2017

Scattering media have always been looked upon as an obstacle in imaging. Various methods, ranging from holography to phase compensation as well as to correlation techniques, have been proposed to cope with this obstacle. We, on the other hand, have a different understanding about the role of the diffusing media. In this paper we propose and demonstrate a ‘scatter-plate microscope’ that utilizes the diffusing property of the random medium for imaging micro structures with diffraction-limited resolution. The ubiquitous property of the speckle patterns permits to exploit the scattering medium as an ultra-thin lensless microscope objective with a variable focal length and a large working distance. The method provides a light, flexible and cost effective imaging device as an alternative to conventional microscope objectives. In principle, the technique is also applicable to lensless imaging in UV and X-ray microscopy. Experiments were performed with visible light to demonstrate the microscopic imaging of USAF resolution test target and a biological sample with varying numerical aperture (NA) and magnifications.
Calaxin establishes basal body orientation and coordinates movement of monocilia in sea urchin embryos
Authors: Mizuno Katsutoshi , Shiba Kogiku , Yaguchi Junko , Shibata Daisuke , Yaguchi Shunsuke , Prulière Gérard , Chenevert Janet , Inaba Kazuo
Published: August 2017

Through their coordinated alignment and beating, motile cilia generate directional fluid flow and organismal movement. While the mechanisms used by multiciliated epithelial tissues to achieve this coordination have been widely studied, much less is known about regulation of monociliated tissues such as those found in the vertebrate node and swimming planktonic larvae. Here, we show that a calcium sensor protein associated with outer arm dynein, calaxin, is a critical regulator for the coordinated movements of monocilia. Knockdown of calaxin gene in sea urchin embryos results in uncoordinated ciliary beating and defective directional movement of the embryos, but no apparent abnormality in axoneme ultrastructure. Examination of the beating cycle of individual calaxin-deficient cilia revealed a marked effect on the waveform and spatial range of ciliary bending. These findings indicate that calaxin-mediated regulation of ciliary beating is responsible for proper basal body orientation and ciliary alignment in fields of monociliated cells.
A novel role of the soybean clock gene LUX ARRHYTHMO in male reproductive development
Authors: Liew Lim Chee , Singh Mohan B. , Bhalla Prem L.
Published: August 2017

The evening complex of ELF4-ELF3-LUX proteins is an integral component of a plant circadian clock. LUX ARRHYTHMO (LUX) is one of the key components of the evening complex, and that play a key role in circadian rhythms and flowering. Here, we report that diverged soybean LUX has the additional role in male reproductive development. We studied diurnal and circadian rhythms of soybean LUX (GmLUXa, GmLUXb, and GmLUXc) using qRT-PCR, and show its nuclear localisation by particle bombardment. Yeast-two hybrid (Y2H) studies indicate that both GmLUXb and GmLUXc form an evening complex with GmELF4b and GmELF3a, respectively. Ectopic expression of GmLUXb in Arabidopsis lux mutants can complement functions of AtLUX, whereas GmLUXc generates novel phenotypes of serrated leaves, stunted plants, shortened anther filament, and low seed set. Overall, our results suggest that the LUX gene has diverged in soybean where GmLUXb and GmLUXc share the role to control flowering time, but GmLUXc has evolved to regulate anther filament growth and seed set by regulating the Gibberellin hormone biosynthesis pathway.
Peptide-mediated delivery of donor mitochondria improves mitochondrial function and cell viability in human cybrid cells with the MELAS A3243G mutation
Authors: Chang Jui-Chih , Hoel Fredrik , Liu Ko-Hung , Wei Yau-Huei , Cheng Fu-Chou , Kuo Shou-Jen , Tronstad Karl Johan , Liu Chin-San
Published: August 2017

The cell penetrating peptide, Pep-1, has been shown to facilitate cellular uptake of foreign mitochondria but further research is required to evaluate the use of Pep-1-mediated mitochondrial delivery (PMD) in treating mitochondrial defects. Presently, we sought to determine whether mitochondrial transplantation rescue mitochondrial function in a cybrid cell model of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) disease. Following PMD, recipient cells had internalized donor mitochondria after 1 h, and expressed higher levels of normal mitochondrial DNA, particularly at the end of the treatment and 11 days later. After 4 days, mitochondrial respiratory function had recovered and biogenesis was evident in the Pep-1 and PMD groups, compared to the untreated MELAS group. However, only PMD was able to reverse the fusion-to-fission ratio of mitochondrial morphology, and mitochondria shaping proteins resembled the normal pattern seen in the control group. Cell survival following hydrogen peroxide-induced oxidative stress was also improved in the PMD group. Finally, we observed that PMD partially normalized cytokine expression, including that of interleukin (IL)-7, granulocyte macrophage–colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF), in the MELAS cells. Presently, our data further confirm the protective effects of PMD as well in MELAS disease.
The influence of the mating type on virulence of Mucor irregularis
Authors: Xu Wenqi , Liang Guanzhao , Peng Jingwen , Long Zhimin , Li Dongmei , Fu Meihua , Wang Qiong , Shen Yongnian , Lv Guixia , Mei Huan , Tsui Clement K. M. , Liu Weida
Published: August 2017

Mucor irregularis is an emerging fungal pathogen that cause cutaneous infection and could cause death. However, little is known about its mechanism of pathogenesis. There is evidence suggesting virulence vary with mating types in fungi, including the Mucorales. Here, we characterized the mating type locus of M. irregularis and the mating type ratio of 17 clinical isolates in China. Genomic data indicated M. irregularis is heterothallic having two mating types – bearing either SexP or SexM allele. Also, we employed a mice model to study the inflammation and pathological effects of different mating types. The comparison of the inflammatory response, cytokine profiles and Th-1, Th-2 and Th-17 cells numbers in each mating type treated mice showed that the severity and disease progress were enhanced in (+) mating type treated mice. One (+/0) mutant strain, with multiple mutations at the mating locus, had defects in sexual mating ability but appeared to be more virulent than the (−) mating type. Although (+) mating type appeared to be more virulent, most of our clinical isolates presented belonged to (−) mating type. Our findings support the involvement of MAT genes in sexual fertility, and the influence of mating type on the severity of cutaneous infection.
RETRACTED ARTICLE: Accelerated oral wound healing using a pre-vascularized mucosal cell sheet
Authors: Lee Jaewang , Kim Eun Hye , Shin Daiha , Roh Jong-Lyel
Published: August 2017

Cell sheets with pre-vascularization have recently been developed but remain relatively untested in oral wound healing. Therefore, we examined the potential utility of our newly developed pre-vascularized mucosal cell sheets in oral wound healing. Mucosal keratinocytes, fibroblasts, and endothelial progenitor cells were primarily cultured for in vitro cell expansion from mucosa and blood of Sprague-Dawley rats. Mucosal cell sheets were generated using cultured keratinocytes and plasma fibrin (K sheet) or keratinocytes and a mixture of fibrin, fibroblasts, and endothelial cells (PV sheet). Autologous sheets were transplanted on deep wounds in the buccal region of rats. The gross and histological characteristics of wound healing were compared among control wound, K sheet, and PV sheet groups. We successfully cultured and expanded keratinocytes, fibroblasts, and endothelial progenitor cells in vitro for generating mucosal cell sheets with or without pre-vascularization. In the in vivo oral wound model, compared with the control wound, the PV sheet group exhibited rapid wound closure more prominently than the K sheet group. The histological healing in the PV sheet group was similar to that in rat normal buccal mucosa without fibrosis. The pre-vascularized mucosal cell sheet exhibited in vivo efficacy in oral wound healing by promoting accelerated healing.
Impact of phenolic compounds in the acyl homoserine lactone-mediated quorum sensing regulatory pathways
Authors: Hossain Md. Akil , Lee Seung-Jin , Park Na-Hye , Mechesso Abraham Fikru , Birhanu Biruk Tesfaye , Kang JeongWoo , Reza Md. Ahsanur , Suh Joo-Won , Park Seung-Chun
Published: August 2017

Quorum sensing (QS) is a cell density-dependent regulation of virulent bacterial gene expression by autoinducers that potentially pertains in the epidemic of bacterial virulence. This study was initially designed to evaluate the effect of 5 phenolic compounds in the modulation of QS and virulence factors of Chromobacterium violaceum and Pseudomonas aeruginosa, and to determine the mechanisms of their effects. Biosensor strains were used to assess antibacterial and anti-QS effect of these compounds. Only methyl gallate (MG) among these compounds demonstrated profound anti-QS effect in the preliminary study, and thus only MG was utilized further to evaluate the effects on the synthesis and activity of acyl homoserine lactone (AHL) in C. violaceum and on the modulation of biofilm, motility, proteolytic, elastase, pyocyanin, and rhamnolipid activity in P. aeruginosa. Finally, the effect of MG on the expression of QS-regulated genes of P. aeruginosa was verified. MG suppressed both the synthesis and activity of AHL in C. violaceum. It also restricted the biofilm formation and other QS-associated virulence factor of P. aeruginosa. MG concentration-dependently suppressed the expression of lasI/R, rhlI/R, and pqsA of P. aeruginosa and was non-toxic in in vitro study. This is the first report of the anti-QS mechanism of MG.
Cryo-EM Studies of Drp1 Reveal Cardiolipin Interactions that Activate the Helical Oligomer
Authors: Francy Christopher A. , Clinton Ryan W. , Fröhlich Chris , Murphy Colleen , Mears Jason A.
Published: August 2017

Dynamins are mechano-chemical GTPases involved in the remodeling of cellular membranes. In this study, we have investigated the mechanism of dynamin-related protein 1 (Drp1), a key mediator of mitochondrial fission. To date, it is unclear how Drp1 assembles on the mitochondrial outer membrane in response to different lipid signals to induce membrane fission. Here, we present cryo-EM structures of Drp1 helices on nanotubes with distinct lipid compositions to mimic membrane interactions with the fission machinery. These Drp1 polymers assemble exclusively through stalk and G-domain dimerizations, which generates an expanded helical symmetry when compared to other dynamins. Interestingly, we found the characteristic gap between Drp1 and the lipid bilayer was lost when the mitochondrial specific lipid cardiolipin was present, as Drp1 directly interacted with the membrane. Moreover, this interaction leads to a change in the helical structure, which alters G-domain interactions to enhance GTPase activity. These results demonstrate how lipid cues at the mitochondrial outer membrane (MOM) can alter Drp1 structure to activate the fission machinery.
Functional association of cellular microtubules with viral capsid assembly supports efficient hepatitis B virus replication
Authors: Iwamoto Masashi , Cai Dawei , Sugiyama Masaya , Suzuki Ryosuke , Aizaki Hideki , Ryo Akihide , Ohtani Naoko , Tanaka Yasuhito , Mizokami Masashi , Wakita Takaji , Guo Haitao , Watashi Koichi
Published: August 2017

Viruses exploit host factors and environment for their efficient replication. The virus-host interaction mechanisms for achieving an optimal hepatitis B virus (HBV) replication have been largely unknown. Here, a single cell cloning revealed that HepAD38 cells, a widely-used HBV-inducible cell line, contain cell clones with diverse permissiveness to HBV replication. The HBV permissiveness was impaired upon treatment with microtubule inhibitor nocodazole, which was identified as an HBV replication inhibitor from a pharmacological screening. In the microtubule-disrupted cells, the efficiency of HBV capsid assembly was remarkably decreased without significant change in pre-assembly process. We further found that HBV core interacted with tubulin and co-localized with microtubule-like fibriforms, but this association was abrogated upon microtubule-disassembly agents, resulting in attenuation of capsid formation. Our data thus suggest a significant role of microtubules in the efficient capsid formation during HBV replication. In line with this, a highly HBV permissive cell clone of HepAD38 cells showed a prominent association of core-microtubule and thus a high capacity to support the capsid formation. These findings provide a new aspect of virus-cell interaction for rendering efficient HBV replication.
Abnormal Electroretinogram after Kir7.1 Channel Suppression Suggests Role in Retinal Electrophysiology
Authors: Shahi Pawan K. , Liu Xinling , Aul Bryce , Moyer Andrea , Pattnaik Akshita , Denton Jerod , Pillers De-Ann M. , Pattnaik Bikash R.
Published: August 2017

The KCNJ13 gene encodes the inwardly rectifying potassium channel, Kir7.1. Mutations in this gene cause childhood blindness, in which the a- and b-wave responses of electroretinogram (ERG) are abolished. The ERG a-wave is the light-induced hyperpolarization of retinal photoreceptors, and the b-wave is the depolarization of ON-bipolar cells. The Kir7.1 channel is localized to the apical aspects of retinal pigment epithelium (RPE) cells and contributes to a delayed c-wave response. We sought to understand why a defect in an RPE ion-channel result in abnormal electrophysiology at the level of the retinal neurons. We have established the expression of Kir7.1 channels in the mouse RPE. ERGs recorded after mice Kir7.1 suppression by shRNA, or by blocking with VU590, showed reduced a-, b- and c-wave amplitudes. In contrast, the Kir7.1 blocker had no effect on the ex-vivo isolated mouse retina ERG where the RPE is not attached to the isolated retina preparation. Finally, we confirmed the specificity of VU590 action by inhibition of native mouse RPE Kir7.1 current in patch-clamp experiment. We propose that mutant RPE Kir7.1 channels contribute directly to the abnormal ERG associated with blindness via alterations in sub-retinal space K+ homeostasis in the vicinity of the photoreceptor outer segment.
Closing the bandgap for III-V nitrides toward mid-infrared and THz applications
Authors: Lu Pengfei , Liang Dan , Chen Yingjie , Zhang Chunfang , Quhe Ruge , Wang Shumin
Published: August 2017

A theoretical study of InNBi alloy by using density functional theory is presented. The results show non-linear dependence of the lattice parameters and bulk modulus on Bi composition. The formation energy and thermodynamic stability analysis indicate that the InNBi alloy possesses a stable phase over a wide range of intermediate compositions at a normal growth temperature. The bandgap of InNBi alloy in Wurtzite (WZ) phase closes for Bi composition higher than 1.5625% while that in zinc-blende (ZB) phase decreases significantly at around 356 meV/%Bi. The Bi centered ZB InNBi alloy presents a change from a direct bandgap to an indirect bandgap up to 1.5625% Bi and then an oscillates between indirect bandgap and semi-metallic for 1.5625% to 25% Bi and finally to metallic for higher Bi compositions. For the same Bi composition, its presence in cluster or uniform distribution has a salient effect on band structures and can convert between direct and indirect bandgap or open the bandgap from the metallic gap. These interesting electronic properties enable III-nitride closing the bandgap and make this material a good candidate for future photonic device applications in the mid-infrared to THz energy regime.
Loss of NR2E3 represses AHR by LSD1 reprogramming, is associated with poor prognosis in liver cancer
Authors: Khanal Tilak , Choi Kwangmin , Leung Yuet-Kin , Wang Jiang , Kim Dasom , Janakiram Vinothini , Cho Sung-Gook , Puga Alvaro , Ho Shuk-Mei , Kim Kyounghyun
Published: August 2017

The aryl hydrocarbon receptor (AHR) plays crucial roles in inflammation, metabolic disorder, and cancer. However, the molecular mechanisms regulating AHR expression remain unknown. Here, we found that an orphan nuclear NR2E3 maintains AHR expression, and forms an active transcriptional complex with transcription factor Sp1 and coactivator GRIP1 in MCF-7 human breast and HepG2 liver cancer cell lines. NR2E3 loss promotes the recruitment of LSD1, a histone demethylase of histone 3 lysine 4 di-methylation (H3K4me2), to the AHR gene promoter region, resulting in repression of AHR expression. AHR expression and responsiveness along with H3K4me2 were significantly reduced in the livers of Nr2e3rd7 (Rd7) mice that express low NR2E3 relative to the livers of wild-type mice. SP2509, an LSD1 inhibitor, fully restored AHR expression and H3K4me2 levels in Rd7 mice. Lastly, we demonstrated that both AHR and NR2E3 are significantly associated with good clinical outcomes in liver cancer. Together, our results reveal a novel link between NR2E3, AHR, and liver cancer via LSD1-mediated H3K4me2 histone modification in liver cancer development.
CLEC14a-HSP70-1A interaction regulates HSP70-1A-induced angiogenesis
Authors: Jang Jihye , Kim Mi Ra , Kim Taek-Keun , Lee Woo Ran , Kim Jong Heon , Heo Kyun , Lee Sukmook
Published: August 2017

CLEC14a (C-type lectin domain family 14 member) is a tumor endothelial cell marker protein that is known to play an important role in tumor angiogenesis, but the basic molecular mechanisms underlying this function have not yet been clearly elucidated. In this study, using various proteomic tools, we isolated a 70-kDa protein that interacts with the C-type lectin-like domain of CLEC14a (CLEC14a-CTLD) and identified it as heat shock protein 70-1A (HSP70-1A). Co-immunoprecipitation showed that HSP70-1A and CLEC14a interact on endothelial cells. In vitro binding analyses identified that HSP70-1A specifically associates with the region between amino acids 43 and 69 of CLEC14a-CTLD. Competitive blocking experiments indicated that this interacting region of CLEC14a-CTLD significantly inhibits HSP70-1A-induced extracellular signal-regulated kinase (ERK) phosphorylation and endothelial tube formation by directly inhibiting CLEC14a-CTLD-mediated endothelial cell-cell contacts. Our data suggest that the specific interaction of HSP70-1A with CLEC14a may play a critical role in HSP70-1A-induced angiogenesis and that the HSP70-1A-interacting region of CLEC14a-CTLD may be a useful tool for inhibiting HSP70-1A-induced angiogenesis.
Oxygen Mapping of Melanoma Spheroids using Small Molecule Platinum Probe and Phosphorescence Lifetime Imaging Microscopy
Authors: Raza Ahtasham , Colley Helen E. , Baggaley Elizabeth , Sazanovich Igor V. , Green Nicola H. , Weinstein Julia A. , Botchway Stanley W. , MacNeil Sheila , Haycock John W.
Published: August 2017

Solid tumours display varied oxygen levels and this characteristic can be exploited to develop new diagnostic tools to determine and exploit these variations. Oxygen is an efficient quencher of emission of many phosphorescent compounds, thus oxygen concentration could in many cases be derived directly from relative emission intensity and lifetime. In this study, we extend our previous work on phosphorescent, low molecular weight platinum(II) complex as an oxygen sensing probe to study the variation in oxygen concentration in a viable multicellular 3D human tumour model. The data shows one of the first examples of non-invasive, real-time oxygen mapping across a melanoma tumour spheroid using one-photon phosphorescence lifetime imaging microscopy (PLIM) and a small molecule oxygen sensitive probe. These measurements were quantitative and enabled real time oxygen mapping with high spatial resolution. This combination presents as a valuable tool for optical detection of both physiological and pathological oxygen levels in a live tissue mass and we suggest has the potential for broader clinical application.
Membrane association of the bacterial riboregulator Hfq and functional perspectives
Authors: Malabirade Antoine , Morgado-Brajones Javier , Trépout Sylvain , Wien Frank , Marquez Ileana , Seguin Jérôme , Marco Sergio , Velez Marisela , Arluison Véronique
Published: August 2017

Hfq is a bacterial RNA binding protein that carries out several roles in genetic expression regulation, mainly at the post-transcriptional level. Previous studies have shown its importance in growth and virulence of bacteria. Here, we provide the direct observation of its ability to interact with membranes. This was established by co-sedimentation assay, cryo-transmission electron (cryo-TEM) and atomic force (AFM) microscopies. Furthermore, our results suggest a role for its C-terminus amyloidogenic domain in membrane disruption. Precisely, AFM images of lipid bilayers in contact with Hfq C-terminus fibrils show the emergence of holes with a size dependent on the time of interaction. Cryo-TEM observations also show that liposomes are in contact with clusters of fibrils, with occasional deformation of the vesicles and afterward the apparition of a multitude of tiny vesicles in the proximity of the fibrils, suggesting peptide-induced breakage of the liposomes. Finally, circular dichroism spectroscopy demonstrated a change in the secondary structure of Hfq C-terminus upon interaction with liposomes. Altogether, these results show an unexpected property of Hfq and suggest a possible new role for the protein, exporting sRNA outside of the bacterial cell.
Tillage and nitrogen fertilization enhanced belowground carbon allocation and plant nitrogen uptake in a semi-arid canola crop–soil system
Authors: Sarker Jharna Rani , Singh Bhupinder Pal , He Xinhua , Fang Yunying , Li Guangdi D. , Collins Damian , Cowie Annette L.
Published: August 2017

Carbon (C) and nitrogen (N) allocation and assimilation are coupled processes, likely influencing C accumulation, N use efficiency and plant productivity in agro-ecosystems. However, dynamics and responses of these processes to management practices in semi-arid agro-ecosystems are poorly understood. A field-based13CO2and urea-15N pulse labelling experiment was conducted to track how C and N allocation and assimilation during canola growth from flowering to maturity were affected by short-term (2-year) tillage (T) and no-till (NT) with or without 100 kg urea-N ha−1(T-0, T-100, NT-0, NT-100) on a Luvisol in an Australian semi-arid region. The T-100 caused greater (P < 0.05) belowground C allocation and higher (P < 0.05) translocation of soil N to shoots and seeds, compared to other treatments. Microbial N uptake was rapid and greatest in the fertilized (cf. non-fertilized) treatments, followed by a rapid release of microbial immobilized N, thus increasing N availability for plant uptake. In contrast, management practices had insignificant impact on soil C and N stocks, aggregate stability, microbial biomass, and13C retention in aggregate-size fractions. In conclusion, tillage and N fertilization increased belowground C allocation and crop N uptake and yield, possiblyviaenhancing root–microbial interactions, with minimal impact on soil properties.
Semi-transparent Perovskite Solar Cells Developed by Considering Human Luminosity Function
Authors: Kim Gyu Min , Tatsuma Tetsu
Published: August 2017

Semi-transparent solar cells draw a great deal of attention because their applications include, for instance, photovoltaic windows. General approach to semi-transparent cells is using thin active layers or island-type structures. Here we take human luminosity function into account, and develop solar cells that harvest photons in the wavelength regions in which human eyes are less sensitive to light. We used an organic-inorganic hybrid perovskite, which is sensitive to light particularly in the blue and deep-blue regions, and plasmonic silver nanocubes that enhance light harvesting in the red and deep-red ranges. In order to tune the plasmonic wavelength to that range, we took advantage of electrode-coupled plasmons (ECPs). We prepared non-plasmonic semi-transparent solar cells, and reduced the active layer thickness and introduced ECPs, so that the visual transparency index and power conversion efficiency of the cell were improved by 28% and 6%, respectively, of the initial values.
Broadband angle- and permittivity-insensitive nondispersive optical activity based on planar chiral metamaterials
Authors: Song Kun , Su Zhaoxian , Wang Min , Silva Sinhara , Bhattarai Khagendra , Ding Changlin , Liu Yahong , Luo Chunrong , Zhao Xiaopeng , Zhou Jiangfeng
Published: August 2017

Because of the strong inherent resonances, the giant optical activity obtained via chiral metamaterials generally suffers from high dispersion, which has been a big stumbling block to broadband applications. In this paper, we propose a type of planar chiral metamaterial consisting of interconnected metal helix slat structures with four-fold symmetry, which exhibits nonresonant Drude-like response and can therefore avoid the highly dispersive optical activity resulting from resonances. It shows that the well-designed chiral metamaterial can achieve nondispersive and pure optical activity with high transmittance in a broadband frequency range. And the optical activity of multi-layer chiral metamaterials is proportional to the layer numbers of single-layer chiral metamaterial. Most remarkably, the broadband behaviors of nondispersive optical activity and high transmission are insensitive to the incident angles of electromagnetic waves and permittivity of dielectric substrate, thereby enabling more flexibility in polarization manipulation.
Transglutaminase 2 regulates osteoclast differentiation via a Blimp1-dependent pathway
Authors: Kim Woo-Shin , Kim Haemin , Jeong Eui Man , Kim Hyung Joon , Lee Zang Hee , Kim In-Gyu , Kim Hong-Hee
Published: August 2017

Transglutaminase 2 (TG2) performs multiple reactions, including transamidation, and also plays a role in signal transduction as a GTP-binding protein. In this study, we reveal that TG2 controls osteoclast differentiation and bone homeostasis in mice. Osteoclasts specifically expressed the TG2 isoform among eight TG family members. Suppression in TG2 expression with siRNA led to increased osteoclast formation from primary mouse precursor cells in response to receptor activator of nuclear factor kappaB ligand (RANKL). This osteoclastogenic effect of TG2 knockdown was associated with enhanced induction of c-Fos and NFATc1 by RANKL. Moreover, TG2 knockdown up-regulated B lymphocyte-induced maturation protein 1 (Blimp1), which represses anti-osteoclastogenic genes, in a manner dependent on the NF-κB signaling pathway. To the contrary, TG2 overexpression inhibited osteoclast formation and the expression of osteoclastogenic genes. Consistent with these in vitro results, TG2 knockout mice exhibited lower trabecular bone mass and increased number of osteoclasts compared with wild-type mice. Taken together, our results provide strong evidence that TG2 plays an important role in bone metabolism by suppressing excessive osteoclastogenesis via the regulation of the NF-κB-Blimp1 signaling pathway.
Rate-limiting steps in transcription dictate sensitivity to variability in cellular components
Authors: Mäkelä Jarno , Kandavalli Vinodh , Ribeiro Andre S.
Published: August 2017

Cell-to-cell variability in cellular components generates cell-to-cell diversity in RNA and protein production dynamics. As these components are inherited, this should also cause lineage-to-lineage variability in these dynamics. We conjectured that these effects on transcription are promoter initiation kinetics dependent. To test this, first we used stochastic models to predict that variability in the numbers of molecules involved in upstream processes, such as the intake of inducers from the environment, acts only as a transient source of variability in RNA production numbers, while variability in the numbers of a molecular species controlling transcription of an active promoter acts as a constant source. Next, from single-cell, single-RNA level time-lapse microscopy of independent lineages of Escherichia coli cells, we demonstrate the existence of lineage-to-lineage variability in gene activation times and mean RNA production rates, and that these variabilities differ between promoters and inducers used. Finally, we provide evidence that this can be explained by differences in the kinetics of the rate-limiting steps in transcription between promoters and induction schemes. We conclude that cell-to-cell and consequent lineage-to-lineage variability in RNA and protein numbers are both promoter sequence-dependent and subject to regulation.
Regional genetic diversity for NNV grouper viruses across the Indo-Asian region – implications for selecting virus resistance in farmed groupers
Authors: Knibb Wayne , Luu Giang , Premachandra H. K. A. , Lu Ming-Wei , Nguyen Nguyen Hong
Published: August 2017

Grouper aquaculture around Asia is impacted by the nervous necrosis virus (NNV) and, in response, host resistance to this infection is being considered as a trait for selection. However efficient selection may be confounded if there are different genetic strains of NNV within and between regions and over years. This study uses statistical approaches and assessment of “characteristic attributes” (i.e. nucleotide positions that discriminate among strains) to assess whether published and new NNV RNA2 cds sequences show genetic differentiation over geography, host species and years. Rather clear evidence was found for regional strains of NNV. Interestingly, most of the geographic defining “characteristic attributes” were in codon position three, and not translated into differences for the protein capsid (i.e. they were synonymous variations), suggesting that while NNV strains were geographically isolated and had diverged in different regions for RNA sequences, selection had largely conserved the protein sequences among regions. The apparent selection constraint on the capsid protein may mitigate the risk that despite geographic subdivision, NNV strain variability will confound genetic selection for host resistance. The existence of regional Asian NNV strains may suggest that hatcheries are at risk from NNV not only from imported material but also from endemic reservoirs.
Iron-dependent reconfiguration of the proteome underlies the intracellular lifestyle of Brucella abortus
Authors: Roset M. S. , Alefantis T. G. , DelVecchio V. G. , Briones G.
Published: August 2017

Brucella ssp. is a facultative intracellular pathogen that causes brucellosis, a worldwide zoonosis that affects a wide range of mammals including humans. A critical step for the establishment of a successful Brucella infection is its ability to survive within macrophages. To further understand the mechanisms that Brucella utilizes to adapt to an intracellular lifestyle, a differential proteomic study was performed for the identification of intracellular modulated proteins. Our results demonstrated that at 48 hours post-infection Brucella adjusts its metabolism in order to survive intracellularly by modulating central carbon metabolism. Remarkably, low iron concentration is likely the dominant trigger for reprogramming the protein expression profile. Up-regulation of proteins dedicated to reduce the concentration of reactive oxygen species, protein chaperones that prevent misfolding of proteins, and proteases that degrade toxic protein aggregates, suggest that Brucella protects itself from damage likely due to oxidative burst. This proteomic analysis of B. abortus provides novel insights into the mechanisms utilized by Brucella to establish an intracellular persistent infection and will aid in the development of new control strategies and novel targets for antimicrobial therapy.
A natural chalcone induces apoptosis in lung cancer cells: 3D-QSAR, docking and an in vivo/vitro assay
Authors: Chen Gang , Zhou Di , Li Xue-Zheng , Jiang Zhe , Tan Chengyu , Wei Xiu-Yan , Ling Junhong , Jing Jing , Liu Fen , Li Ning
Published: August 2017

This study was to study the antitumor effect of lonchocarpin (34) from traditional herbal medicine Pongamia pinnata (L.) Pierre and to reveal the underlying mechanism. The cytotoxic activities of lonchocarpin were evaluated in 10 lung cancer cell lines and it exhibited 97.5% activity at a dose of 100 μM in the H292 cell line. A field-based quantitative structure-activity relationship (3D-QSAR) study of 37 flavonoids from P. pinnata was also performed, and the results obtained showed that the hydrophobic interaction could be the crucial factor for the antitumor activity of lonchocarpin. Molecular docking studies revealed that lonchocarpin bound stably to the BH3-binding groove of the Bcl-2 protein with hydrophobic interactions with ALA146. Also, lonchocarpin significantly reduced cell proliferation via modulating Bax/Caspase-9/Caspase-3 pathway. An apoptotic test using flow cytometry showed that lonchocarpin produced about 41.1% and 47.9% apoptosis after treatment for 24 h and 48 h, respectively. Moreover, lonchocarpin inhibited tumor growth in S180-bearing mice with an inhibition rate of 57.94, 63.40 and 72.51%, respectively at a dose of 25, 50 and 100 mg/kg. These results suggest that lonchocarpin is a potentially useful natural agent for cancer treatment.
Switching the unidirectional reflectionlessness by polarization in non-ideal PT metamaterial based on the phase coupling
Authors: Bai Ruiping , Zhang Cong , Gu Xintong , Jin Xing Ri , Zhang Ying Qiao , Lee YoungPak
Published: August 2017

An effective scheme on switching the exceptional point(EP) where unidirectional reflectionlessness occurs is firstly proposed in non-ideal PT metamaterial via the polarization of incident light. The unidirectional reflectionlessness could be effectively controlled only by adjusting the phase coupling of the two resonators which are consisted of two identical but vertically placed crosses and are excited by incident light as an effective gain. Besides, the unidirectional perfect absorber occurs in the vicinity of EP.