Read by QxMD icon Read

voltage gated potassium channel

Mohammad-Reza Ghovanloo, Mena Abdelsayed, Colin H Peters, Peter C Ruben
Skeletal muscle channelopathies, many of which are inherited as autosomal dominant mutations, include myotonia and periodic paralysis. Myotonia is defined by a delayed relaxation after muscular contraction, whereas periodic paralysis is defined by episodic attacks of weakness. One sub-type of periodic paralysis, known as hypokalemic periodic paralysis (hypoPP), is associated with low potassium levels. Interestingly, the P1158S missense mutant, located in the third domain S4-S5 linker of the "skeletal muscle", Nav1...
April 19, 2018: Scientific Reports
Cyrus S H Ho, Roger C M Ho, Amy M L Quek
Heavy metal poisoning is a rare but important cause of encephalopathy. Manganese (Mn) toxicity is especially rare in the modern world, and clinicians’ lack of recognition of its neuropsychiatric manifestations can lead to misdiagnosis and mismanagement. We describe the case of a man who presented with recurrent episodes of confusion, psychosis, dystonic limb movement and cognitive impairment and was initially diagnosed with anti-voltage-gated potassium channel (VGKC) complex limbic encephalitis in view of previous positive autoantibodies...
April 18, 2018: International Journal of Environmental Research and Public Health
Arturo Ponce, Aida Castillo, Lorena Hinojosa, Jacqueline Martinez-Rendon, Marcelino Cereijido
HEK293 cells are widely used as a host for expression of heterologous proteins; yet, little care has been taken to characterize their endogenous membrane components, including ion channels. In this work, we aimed to describe the biophysical and pharmacological properties of endogenous, voltage-dependent potassium currents (IKv). We also examined how its expression depends on culture conditions. We used the electrophysiological technique of whole-cell patch clamp to record ion currents from HEK293 cells. We found that HEK cells express endogenous, voltage-dependent potassium currents...
April 2018: Physiological Reports
Rishi Kumar Gupta, Dilip Kumar Swain, Vijay Singh, Mukul Anand, Soumen Choudhury, Sarvajeet Yadav, Atul Saxena, Satish Kumar Garg
Present study was undertaken to characterize the voltage gated potassium channel (Kv 1.1) in bull spermatozoa using sixty four ejaculates collected from four Hariana bulls. Functional characterization was undertaken using a selective blocker of Kv channel, 4-Aminopyridine (4-AP) while molecular presence of Kv on bull spermatozoa by immunoblotting and indirect immunofluorescence. Three sets of 100 μL diluted sperm samples namely-negative control (100 μL of sperm dilution medium (SDM) containing 10 × 106  cells), vehicle control (99 μL of SDM containing 10 × 106  cells, and DMSO- 1  μL) and 4-AP treatment group (99 μL of SDM containing 10 × 106  cells, and drug 1 μL 4-AP) were used in the study...
March 26, 2018: Theriogenology
Ya-Jean Wang, Chung-Pin Hsieh, Ming-Huan Chan, Tzu-Yi Chan, Linyi Chen, Hwei-Hisen Chen
OBJECTIVES: The antiepileptic activity of resveratrol has been revealed in various experimental models of epilepsy. The present study evaluated the effects of resveratrol on the seizures and hyperexcitable neuronal activity associated with activation of N-methyl-d-aspartic acid (NMDA) receptor and inhibition of voltage-gated potassium channels. METHODS: The effects of resveratrol on seizure thresholds, excitatory field potentials (EFPs) and action potentials induced by NMDA and 4-aminopyridine (4-AP) were monitored in mice, the mouse cortical slices and rat cortical neurons, respectively...
April 12, 2018: Nutritional Neuroscience
Malin Silverå Ejneby, Xiongyu Wu, Nina E Ottosson, E Peter Münger, Ingemar Lundström, Peter Konradsson, Fredrik Elinder
Dehydroabietic acid (DHAA) is a naturally occurring component of pine resin that was recently shown to open voltage-gated potassium (KV ) channels. The hydrophobic part of DHAA anchors the compound near the channel's positively charged voltage sensor in a pocket between the channel and the lipid membrane. The negatively charged carboxyl group exerts an electrostatic effect on the channel's voltage sensor, leading to the channel opening. In this study, we show that the channel-opening effect increases as the length of the carboxyl-group stalk is extended until a critical length of three atoms is reached...
April 6, 2018: Journal of General Physiology
Wei-Ting Chang, Sheng-Nan Wu
Telmisartan (TEL) is a non-peptide blocker of angiotensin II type-1 (AT1 ) receptor. However, the mechanisms through which this drug interacts directly with ion currents in hearts remain largely unclear. Herein, we aim to investigate the effects of TEL the on ionic currents and membrane potential of murine HL-1 cardiomyocytes. In whole-cell recordings, addition of TEL stimulated the peak and late components of voltage-gated Na+ currents (IN a ) with different potencies. The EC50 values required to achieve the stimulatory effect of this drug on peak and late IN a were 0...
April 4, 2018: Clinical and Experimental Pharmacology & Physiology
Christopher Dockendorff, Disha Manoj Gandhi, Ian H Kimball, Kenneth S Eum, Radda Rusinova, Helgi I Ingólfsson, Ruchi Kapoor, Thasin Peyear, Matthew W Dodge, Stephen F Martin, Richard Aldrich, Olaf S Andersen, Jon T Sack
Drugs do not act solely by canonical ligand-receptor binding interactions. Amphiphilic drugs partition into membranes thereby perturbing bulk lipid bilayer properties and possibly altering the function of membrane proteins. Distinguishing membrane perturbation from more direct protein-ligand interactions is an ongoing challenge in chemical biology. Herein, we present one strategy for doing so using dimeric 6-bromo-2-mercaptotryptamine (BrMT) and synthetic analogs. BrMT is a chemically unstable marine snail toxin that has unique effects on voltage-gated K+ channel proteins, making it an attractive medicinal chemistry lead...
April 4, 2018: Biochemistry
Rosa Angélica Castillo-Rodríguez, Víctor Manuel Dávila-Borja, Sergio Juárez-Méndez
Medulloblastoma is the most common type of solid brain tumor in children. This type of embryonic tumor is highly heterogeneous and has been classified into 4 molecular subgroups based on their gene expression profiles: WNT, SHH, Group 3 (G3) and Group 4 (G4). WNT and SHH tumors exhibit the specific dysregulation of genes and pathways, whereas G3 and G4 tumors, two of the more frequent subtypes, are the least characterized. Thus, novel markers to aid in the diagnosis, prognosis and management of medulloblastoma are required...
May 2018: Oncology Letters
Zhenbo Huang, Carlie A Hoffman, Brandon M Chelette, Nicolas Thiebaud, Debra A Fadool
It has long been recognized that olfaction and emotion are linked. While chemosensory research using both human and rodent models have indicated a change in emotion can contribute to olfactory dysfunction, there are few studies addressing the contribution of olfaction to a modulation in emotion. In mice, olfactory deficits have been linked with heightened anxiety levels, suggesting that there could be an inverse relationship between olfaction and anxiety. Furthermore, increased anxiety is often co-morbid with psychiatric conditions such as attention disorders...
2018: Frontiers in Behavioral Neuroscience
Min Seok Song, Su Min Park, Jeong Seok Park, Jin Ho Byun, Hee Jung Jin, Seung Hyun Seo, Pan Dong Ryu, So Yeong Lee
Voltage-gated potassium (Kv) channels, including Kv3.1 and Kv3.4, are known as oxygen sensors, and their function in hypoxia has been well investigated. However, the relationship between Kv channels and tumor hypoxia has yet to be investigated. This study demonstrates that Kv3.1 and Kv3.4 are tumor hypoxia-related Kv channels involved in cancer cell migration and invasion. Kv3.1 and Kv3.4 protein expression in A549 and MDA-MB-231 cells increased in a cell density-dependent manner, and the pattern was similar to the expression patterns of hypoxia-inducible factor-1α (HIF-1α) and reactive oxygen species (ROS) according to cell density, whereas Kv3...
April 2, 2018: International Journal of Molecular Sciences
Pedro Modesto Nascimento Menezes, Mariana Coelho Brito, Gabriela Olinda de Paiva, Carine Oliveira Dos Santos, Lenaldo Muniz de Oliveira, Luciano Augusto de Araújo Ribeiro, Julianeli Tolentino de Lima, Angélica Maria Lucchese, Fabrício Souza Silva
ETHNOPHARMACOLOGICAL RELEVANCE: Lippia origanoides H.B.K. is an aromatic species used in folk medicine to treat respiratory diseases, including asthma. AIM OF THE STUDY: The aim of this work was to evaluate the relaxing potential and mechanism of action of the L. origanoides (LOO) essential oil in isolated guinea-pig trachea MATERIALS AND METHODS: Leaves from L. origanoides were collected at experimental fields under organic cultivation, at the Forest Garden of Universidade Estadual de Feira de Santana...
March 30, 2018: Journal of Ethnopharmacology
Jingli Zhang, Fatin H Mohamad, Jia Hui Wong, Habsah Mohamad, Abdul Hadi Ismail, Abdul Aziz Mohamed Yusoff, Hasnah Osman, Kok Tong Wong, Zamzuri Idris, Jafri Malin Abdullah
Background: Bamboo shoot has been used as a treatment for epilepsy in traditional Chinese medicine for generations to treat neuronal disorders such as convulsive, dizziness and headaches. 4-hydroxybenzoic acid (4-hba) is a non-flavonoid phenol found abundantly in Dendrocalamus asper shoots (bamboo), fruits (strawberries and apples) and flowers. Kv1.4 is a rapidly inactivating Shaker -related member of the voltage-gated potassium channels with two inactivation mechanisms; the fast N-type and slow C-type...
February 2018: Malaysian Journal of Medical Sciences: MJMS
Vincent Portero, Ronald Wilders, Simona Casini, Flavien Charpentier, Arie O Verkerk, Carol Ann Remme
In cardiomyocytes, the voltage-gated transient outward potassium current (Ito ) is responsible for the phase-1 repolarization of the action potential (AP). Gain-of-function mutations in KCND3 , the gene encoding the Ito carrying KV 4.3 channel, have been associated with Brugada syndrome (BrS). While the role of Ito in the pro-arrhythmic mechanism of BrS has been debated, recent studies have suggested that an increased Ito may directly affect cardiac conduction. However, the effects of an increased Ito on AP upstroke velocity or sodium current at the cellular level remain unknown...
2018: Frontiers in Physiology
Iva Bozic, Katarina Tesovic, Danijela Laketa, Marija Adzic, Marija Jakovljevic, Ivana Bjelobaba, Danijela Savic, Nadezda Nedeljkovic, Sanja Pekovic, Irena Lavrnja
Kv1.3 is a voltage gated potassium channel that has been implicated in pathophysiology of multiple sclerosis (MS). In the present study we investigated temporal and cellular expression pattern of this channel in the lumbar part of spinal cords of animals with experimental autoimmune encephalomyelitis (EAE), animal model of MS. EAE was actively induced in female Dark Agouti rats. Expression of Kv1.3 was analyzed at different time points of disease progression, at the onset, peak and end of EAE. We here show that Kv1...
March 24, 2018: Neurochemical Research
Kylie A Beattie, Adam P Hill, Rémi Bardenet, Yi Cui, Jamie I Vandenberg, David J Gavaghan, Teun P de Boer, Gary R Mirams
Understanding the roles of ion currents is crucial to predict the action of pharmaceuticals and mutations in different scenarios, and thereby to guide clinical interventions in the heart, brain and other electrophysiological systems. Our ability to predict how ion currents contribute to cellular electrophysiology is in turn critically dependent on our characterisation of ion channel kinetics - the voltage-dependent rates of transition between open, closed and inactivated channel states. We present a new method for rapidly exploring and characterising ion channel kinetics, applying it to the hERG potassium channel as an example, with the aim of generating a quantitatively predictive representation of the ion current...
March 24, 2018: Journal of Physiology
Pilar de la Peña, Pedro Domínguez, Francisco Barros
Voltage-dependent KCNH family potassium channel functionality can be reconstructed using non-covalently linked voltage-sensing domain (VSD) and pore modules (split channels). However, the necessity of a covalent continuity for channel function has not been evaluated at other points within the two functionally independent channel modules. We find here that by cutting Kv11.1 (hERG, KCNH2) channels at the different loops linking the transmembrane spans of the channel core, not only channels split at the S4-S5 linker level, but also those split at the intracellular S2-S3 and the extracellular S3-S4 loops, yield fully functional channel proteins...
March 23, 2018: Pflügers Archiv: European Journal of Physiology
Qi Fei, Xiaodong Bai, Jisheng Lin, Hai Meng, Yong Yang, Ai Guo
Postmenopausal osteoporosis (PMOP) is a common skeletal disorder in postmenopausal women. The present study aimed to identify the key long non‑coding RNAs (lncRNAs) in PMOP through RNA sequencing. RNA sequencing was performed to obtain the expression profile of lncRNAs and mRNAs in blood samples of patients with PMOP and normal controls (NCs). Following the identification of differentially expressed mRNAs (DEmRNAs) and differentially expressed lncRNAs (DElncRNAs), the DElncRNA-DEmRNA co‑expression network was constructed...
March 19, 2018: International Journal of Molecular Medicine
Gucan Dai, Zachary M James, William N Zagotta
KCNH voltage-gated potassium channels (EAG, ERG, and ELK) play significant roles in neuronal and cardiac excitability. They contain cyclic nucleotide-binding homology domains (CNBHDs) but are not directly regulated by cyclic nucleotides. Instead, the CNBHD ligand-binding cavity is occupied by an intrinsic ligand, which resides at the intersubunit interface between the N-terminal eag domain and the C-terminal CNBHD. We show that, in Danio rerio ELK channels, this intrinsic ligand is critical for voltage-dependent potentiation (VDP), a process in which channel opening is stabilized by prior depolarization...
March 22, 2018: Journal of General Physiology
Christine Q Simmons, Christopher H Thompson, Bryan E Cawthon, Grant Westlake, Kathryn J Swoboda, Evangelos Kiskinis, Kevin C Ess, Alfred L George
Mutations in ATP1A3 encoding the catalytic subunit of the Na/K-ATPase expressed in mammalian neurons cause alternating hemiplegia of childhood (AHC) as well as an expanding spectrum of other neurodevelopmental syndromes and neurological phenotypes. Most AHC cases are explained by de novo heterozygous ATP1A3 mutations, but the fundamental molecular and cellular consequences of these mutations in human neurons are not known. In this study, we investigated the electrophysiological properties of neurons generated from AHC patient-specific induced pluripotent stem cells (iPSCs) to ascertain functional disturbances underlying this neurological disease...
March 19, 2018: Neurobiology of Disease
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"