Read by QxMD icon Read

Ion channel

Sharon M Moe
Calcium is an important ion in cell signaling, hormone regulation, and bone health. Its regulation is complex and intimately connected to that of phosphate homeostasis. Both ions are maintained at appropriate levels to maintain the extracellular to intracellular gradients, allow for mineralization of bone, and to prevent extra skeletal and urinary calcification. The homeostasis involves the target organs intestine, parathyroid glands, kidney, and bone. Multiple hormones converge to regulate the extracellular calcium level: parathyroid hormone, vitamin D (principally 25(OH)D or 1,25(OH)2D), fibroblast growth factor 23, and α-klotho...
September 15, 2016: Comprehensive Physiology
Sheng-Heng Chung, Chi-Hao Chang, Arumugam Manthiram
Sulfur exhibits a high theoretical capacity of 1,675 mA h g-1 via a distinct conversion reaction, which is different from the insertion reactions in commercial lithium-ion batteries. In consideration of its conversion-reaction battery chemistry, a custom design for electrode materials could establish the way for attaining high-loading capability while simultaneously maintaining high electrochemical utilization and stability. In this study, this process is undertaken by introducing carbon cotton as an attractive electrode-containment material for enhancing the dynamic and static stabilities of lithium-sulfur (Li-S) batteries...
October 26, 2016: ACS Nano
Devasena Ponnalagu, Harpreet Singh
Mitochondria are the "power house" of a cell continuously generating ATP to ensure its proper functioning. The constant production of ATP via oxidative phosphorylation demands a large electrochemical force that drives protons across the highly selective and low-permeable mitochondrial inner membrane. Besides the conventional role of generating ATP, mitochondria also play an active role in calcium signaling, generation of reactive oxygen species (ROS), stress responses, and regulation of cell-death pathways...
October 26, 2016: Handbook of Experimental Pharmacology
Seika Takayanagi-Kiya, Keming Zhou, Yishi Jin
Presynaptic ligand-gated ion channels (LGICs) have long been proposed to affect neurotransmitter release and to tune neural circuit activity. However, the understanding of their in vivo physiological action remains limited, partly due to the complexity in channel types and scarcity of genetic models. Here we report that C. elegans LGC-46, a member of the Cys-loop acetylcholine (ACh)-gated chloride (ACC) channel family, localizes to presynaptic terminals of cholinergic motor neurons and regulates synaptic vesicle (SV) release kinetics upon evoked release of acetylcholine...
October 26, 2016: ELife
M Koselski, A Olszewska, A Hordyjewska, T Małecka-Massalska, K Trebacz
Patch clamp recordings carried out in the inside-out configuration revealed activity of three kinds of channels: nonselective cation channels, small-conductance K(+) channels, and large-conductance anion channels. The nonselective cation channels did not distinguish between Na(+) and K(+). The unitary conductance of these channels reached 28 pS in a symmetrical concentration of 200 mM NaCl. A lower value of this parameter was recorded for the small-conductance K(+) channels and in a 50-fold gradient of K(+) (200 mM/4 mM) it reached 8 pS...
October 26, 2016: Physiological Research
Marta Tarkanovskaja, Kuno Kooser, Helena Levola, Ergo Nõmmiste, Edwin Kukk
Photofragmentation of small gas-phase acetamide clusters (CH3CONH2)n (n ≤ 10) produced by a supersonic expansion source has been studied using time-of-flight ion mass spectroscopy combined with tunable vacuum-ultraviolet (VUV) synchrotron radiation. Fragmentation channels of acetamide clusters under VUV photoionization resulting in protonated and ammoniated clusters formation were identified with the discussion about the preceding intramolecular rearrangements. Acetamide-2,2,2-d3 clusters were also studied in an experiment with a gas discharge lamp as a VUV light source; comparison with the main experiment gave insights into the mechanism of formation of protonated acetamide clusters, indicating that proton transfer from amino group plays a dominant role in that process...
September 28, 2016: Journal of Chemical Physics
I M Fuentes, J A Christianson
Ion channels are expressed throughout the gastrointestinal system and regulate nearly every aspect of digestion, including fluid secretion and absorption, motility, and visceral sensitivity. It is therefore not surprising that in the setting of functional bowel disorders, such as irritable bowel syndrome (IBS), ion channels are often altered in terms of expression level and function and are a target of pharmacological intervention. This is particularly true of their role in driving abdominal pain through visceral hypersensitivity (VH), which is the main reason IBS patients seek medical care...
November 2016: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
Hailong Yan, Tong Li, Yang Lu, Jinbing Cheng, Tao Peng, Jinyou Xu, Linying Yang, Xiangqiang Hua, Yunxin Liu, Yongsong Luo
In this article, ordered ZnO@ZnS core-shell structures have been produced on a stainless mesh by a two-step approach without using a template. ZnO nanorods fabricated by a chemical vapor method are transferred into a 50 ml autoclave for a second stage ion-exchange reaction followed by heating at 120 °C for 4-16 h. The ZnO core is prepared as the conducting channel and ZnS as the active material. Such unique architecture exhibits remarkable electrochemical performance with high capacitance and desirable cycle life...
October 26, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Steffen Syrbe, Boris S Zhorov, Astrid Bertsche, Matthias K Bernhard, Frauke Hornemann, Ulrike Mütze, Jessica Hoffmann, Konstanze Hörtnagel, Wieland Kiess, Franz W Hirsch, Johannes R Lemke, Andreas Merkenschlager
Mutations in SCN2A have been associated with benign familial neonatal-infantile seizures (BFNIS) as well as infantile-onset epileptic encephalopathy, such as Ohtahara syndrome (OS). We describe a family with 3 affected individuals carrying the novel SCN2A missense variant c.1147C>G, p.Q383E affecting a residue proximal to the highly conserved selectivity filter in the P-loop of the voltage-gated sodium channel (Nav1.2). All 3 individuals presented with seizures in early infancy. However, there were striking differences in the spectrum of clinical presentations, ranging from BFNIS to OS...
September 2016: Molecular Syndromology
Xiangyu Cai, Yandong Zhou, Robert M Nwokonko, Natalia A Loktionova, Xianming Wang, Ping Xin, Mohamed Trebak, Youjun Wang, Donald L Gill
Orai channels mediate store-operated Ca2+ signals crucial in regulating transcription in many cell types, and implicated in numerous immunological and inflammatory disorders. Despite their central importance, controversy surrounds the basic subunit structure of Orai channels, several biochemical and biophysical studies suggesting a tetrameric structure yet crystallographic evidence indicating a hexamer. We systematically investigated the subunit configuration of the functional Orai1 channel, generating a series of tdTomato-tagged concatenated Orai1 channel constructs (dimers to hexamers) expressed in CRISPR-derived Orai1-knockout HEK cells, stably expressing STIM1-YFP...
October 25, 2016: Journal of Biological Chemistry
Pritom Shah, Anne Cheasty, Caroline Foxton, Tony Raynham, Muddasar Farooq, Irene Farre Gutierrez, Aurore Lejeune, Michelle Pritchard, Andrew Turnbull, Leon Pang, Paul Owen, Susan Boyd, Alexandra Stowell, Allan Jordan, Niall M Hamilton, James R Hitchin, Martin Stockley, Ellen MacDonald, Mar Jimenez Quesada, Elisabeth Trivier, Jana Skeete, Huib Ovaa, Wouter H Moolenaar, Hamish Ryder
The autotoxin-lysophosphatidic acid (ATX-LPA) axis has been implicated in several disease conditions including inflammation, fibrosis and cancer. This makes ATX an attractive drug target and its inhibition may lead to useful therapeutic agents. Through a high throughput screen (HTS) we identified a series of small molecule inhibitors of ATX which have subsequently been optimized for potency, selectivity and developability properties. This has delivered drug-like compounds such as 9v (CRT0273750) which modulate LPA levels in plasma and are suitable for in vivo studies...
October 14, 2016: Bioorganic & Medicinal Chemistry Letters
Hui Ren, Nigel P Birch, Vinod Suresh
Robust and reproducible in vitro models are required for investigating the pathways involved in fluid homeostasis in the human alveolar epithelium. We performed functional and phenotypic characterisation of ion transport in the human pulmonary epithelial cell lines NCI-H441 and A549 to determine their similarity to primary human alveolar type II cells. NCI-H441 cells exhibited high expression of junctional proteins ZO-1, and E-cadherin, seal-forming claudin-3, -4, -5 and Na+-K+-ATPase while A549 cells exhibited high expression of pore-forming claudin-2...
2016: PloS One
Valentina Gallo, F Nicole Dijk, John W Holloway, Susan M Ring, Gerard H Koppelman, Dirkje S Postma, David P Strachan, Raquel Granell, Johan C de Jongste, Vincent W V Jaddoe, Herman T den Dekker, Liesbeth Duijts, A John Henderson, Seif O Shaheen
BACKGROUND: Animal data have suggested that the transient receptor potential ankyrin-1 (TRPA1) ion channel plays a key role in promoting airway inflammation in asthma and may mediate effects of paracetamol on asthma, yet confirmatory human data are lacking. To study associations of TRPA1 gene variants with childhood asthma and total IgE concentration, and interactions between TRPA1 and prenatal paracetamol exposure on these outcomes. METHODS: We analysed associations between 31 TRPA1 single nucleotide polymorphisms (SNPs) and current doctor-diagnosed asthma and total IgE concentration at 7...
October 25, 2016: Pediatric Allergy and Immunology
François Seghers, Xavier Yerna, Nadège Zanou, Olivier Devuyst, Rudi Vennekens, Bernd Nilius, Philippe Gailly
The renin - angiotensin system is a crucial blood pressure regulation system. It consists of a hormonal cascade where the rate-limiting enzyme is renin, which is secreted in blood flow by renal juxtaglomerular (JG) cells in response to low pressure in the renal afferent arteriole. In contrast, an increase in blood pressure results in a decreased renin secretion. This is accompanied by a transitory increase in [Ca(2+) ]i of JG cells. The inverse relationship between [Ca(2+) ]i and renin secretion has been called the "calcium paradox" of renin release...
October 25, 2016: Journal of Physiology
Zheng Zhang, Hannah A Ledford, Seojin Park, Wenying Wang, Sassan Rafizadeh, Hyo Jeong Kim, Wilson Xu, Ling Lu, Victor C Lau, Anne A Knowlton, Xiao-Dong Zhang, Ebenezer N Yamoah, Nipavan Chiamvimonvat
The normal function of ion channels depends critically on the precise subcellular localization and the number of channel proteins on the cell surface membrane. Small-conductance, Ca(2+) -activated K(+) channels (SK, KCa 2) are expressed in human atrial myocytes and responsible for shaping atrial action potentials. Understanding the mechanisms of SK channel trafficking may provide new insights into the regulation controlling the repolarization of atrial myocytes. We have previously demonstrated that the C and N termini of SK2 channels interact with actin-binding proteins, α-actinin2 and filamin A, respectively...
October 25, 2016: Journal of Physiology
N Szentandrassy, B Horvath, K Vaczi, K Kistamas, L Masuda, J Magyar, T Banyasz, Z Papp, P P Nanasi
Omecamtiv mecarbil (OM) is a myosin activator agent recently developed for treatment of heart failure. Although its action on extending systolic ejection time and increasing left ventricular ejection fraction is well documented, no data is available regarding its possible side-effects on cardiac ion channels. Therefore, the present study was designed to investigate the effects of OM on action potential morphology and the underlying ion currents in isolated canine ventricular myocytes using sharp microelectrodes, conventional patch clamp, and action potential voltage clamp techniques...
August 2016: Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society
Dilip Sharma, Jitendra Narain Singh, Shyam S Sharma
Mechanisms and pathways involving in diabetic neuropathy are still not fully understood but can be unified by the process of overproduction of reactive oxygen species (ROS) such as superoxide, endoplasmic reticulum (ER) stress, downstream intracellular signaling pathways and their modulation. Susceptibility of dorsal root ganglion (DRG) to internal/external hyperglycemic environment stress contributes to the pathogenesis and progression of diabetic neuropathy. ER stress leads to abnormal ion channel function, gene expression, transcriptional regulation, metabolism and protein folding...
October 21, 2016: Neuroscience Letters
Feng Wu, Nan Chen, Renjie Chen, Qizhen Zhu, Guoqiang Tan, Li Li
The lack of suitable nonflammable electrolytes has delayed battery application in electric vehicles. A new approach to improve the safety performance for lithium battery is proposed here. This technology is based on a nanogelator-based solid electrolyte made of porous oxides and an ionic liquid. The electrolyte is fabricated using an in situ method and the porous oxides serve as a nonflammable "nanogelator" that spontaneously immobilizes the ionic liquid. The electrolyte exhibits a high liquid-like apparent ionic conductivity of 2...
January 2016: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Hong-Jie Peng, Dai-Wei Wang, Jia-Qi Huang, Xin-Bing Cheng, Zhe Yuan, Fei Wei, Qiang Zhang
Owing to the conversion chemistry of the sulfur cathode, the lithium-sulfur (Li-S) batteries exhibit high theoretical energy density. However, the intrinsic mobile redox centers during the sulfur/Li2S-to-lithium polysulfides solid-to-liquid phase transition induce low sulfur utilization and poor cycling life. Herein, the Janus separator of mesoporous cellular graphene framework (CGF)/polypropylene membrane to promote the utilization of sulfur cathode is introduced. The porous polypropylene membrane serves as an insulating substrate in contact with lithium anode while CGFs that possess high electrical conductivity of 100 S cm(-1), a large mesopore volume of 3...
January 2016: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Ana Clara Aprotosoaie, Irina-Iuliana Costache, Anca Miron
Anethole is the main fragrance and bioactive compound of anise, fennel, and star anise spices and more than other 20 plant species. It is widely used as flavor agent in food industry and other industries, in cosmetics, perfumery, and pharmaceuticals. In the last few years, various studies have revealed multiple beneficial effects of anethole for human health, such as anti-inflammatory, anticarcinogenic and chemopreventive, antidiabetic, immunomodulatory, neuroprotective, or antithrombotic, that are mediated by the modulation of several cell signaling pathways, mainly NF-kB and TNF-α signaling, and various ion channels...
2016: Advances in Experimental Medicine and Biology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"