Read by QxMD icon Read


Daniela Ponce-Balbuena, Guadalupe Guerrero-Serna, Carmen R Valdivia, Ricardo Caballero, F J Díez-Guerra, Eric N Jiménez-Vázquez, Rafael J Ramirez, Andre Monteiro da Rocha, Todd J Herron, Katherine F Campbell, B C Willis, Francisco J Alvarado, Manuel Zarzoso, Kuljeet Kaur, Marta Pérez-Hernández, Marcos Matamoros, Héctor H Valdivia, Eva Delpón, José Jalife
<u>Rationale:</u> In cardiomyocytes, NaV 1.5 and Kir2.1 channels interact dynamically as part of membrane bound macromolecular complexes. <u>Objective:</u> To test whether NaV 1.5 and Kir2.1 preassemble during early forward trafficking and travel together to common membrane microdomains. <u>Methods and Results:</u> In patch-clamp experiments, co-expression of trafficking deficient mutants Kir2.1Δ314-315 or Kir2.1R44A/R46A with wildtype (WT) NaV 1.5WT in heterologous cells reduced INa , compared to NaV 1...
March 7, 2018: Circulation Research
Nhat-Tu Le, Jun-Ichi Abe
No abstract text is available yet for this article.
March 3, 2018: Journal of the American Heart Association
Ibra S Fancher, Sang Joon Ahn, Crystal Adamos, Catherine Osborn, Myung-Jin Oh, Yun Fang, Catherine A Reardon, Godfrey S Getz, Shane A Phillips, Irena Levitan
BACKGROUND: Hypercholesterolemia-induced decreased availability of nitric oxide (NO) is a major factor in cardiovascular disease. We previously established that cholesterol suppresses endothelial inwardly rectifying K+ (Kir) channels and that Kir2.1 is an upstream mediator of flow-induced NO production. Therefore, we tested the hypothesis that suppression of Kir2.1 is responsible for hypercholesterolemia-induced inhibition of flow-induced NO production and flow-induced vasodilation (FIV)...
March 3, 2018: Journal of the American Heart Association
Ji-Yong Kang, Daichi Kawaguchi, Lei Wang
Deciphering neuronal networks governing specific brain functions is a longstanding mission in neuroscience, yet global manipulation of protein functions pharmacologically or genetically lacks sufficient specificity to reveal a neuronal protein's function in a particular neuron or a circuitry. Photostimulation presents a great venue for researchers to control neuronal proteins with high temporal and spatial resolution. Recently, an approach to optically control the function of a neuronal protein directly in neurons has been demonstrated using genetically encoded light-sensitive Unnatural amino acids (Uaas)...
2018: Methods in Molecular Biology
Kuihao Chen, Dongchuan Zuo, Sho-Ya Wang, Haijun Chen
Spontaneous rhythmic action potential or pacemaking activity of pacemaker cells controls rhythmic signaling such as heartbeat. The mechanism underlying the origin of pacemaking activity is not well understood. In this study, we created human embryonic kidney (HEK) 293 cells that show pacemaking activity through heterologous expression of strong inward rectifier K+ channels (Kir2.1), hyperpolarization-activated cyclic nucleotide-gated nonselective cation channels (HCN2), and voltage-gated Na+ or Ca2+ channels (Nav1...
January 12, 2018: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Shinya Yamada, Man-Cai Fong, Ya-Wen Hsiao, Shih-Lin Chang, Yung-Nan Tsai, Li-Wei Lo, Tze-Fan Chao, Yenn-Jiang Lin, Yu-Feng Hu, Fa-Po Chung, Jo-Nan Liao, Yao-Ting Chang, Hsing-Yuan Li, Satoshi Higa, Shih-Ann Chen
BACKGROUND: Myocardial infarction increases the risk of heart failure (HF) and atrial fibrillation. Renal denervation (RDN) might suppress the development of atrial remodeling. This study aimed to elucidate the molecular mechanism of RDN in the suppression of atrial fibrillation in a HF model after myocardial infarction. METHODS AND RESULTS: HF rabbits were created 4 weeks after coronary ligation. Rabbits were classified into 3 groups: normal control (n=10), HF (n=10), and HF-RDN (n=6)...
January 22, 2018: Journal of the American Heart Association
Wei Wu, Hang Yao, Helen W Zhao, Juan Wang, Gabriel G Haddad
Chronic mountain sickness (CMS) or Monge's disease is a disease in highlanders. These patients have a variety of neurologic symptoms such as migraine, mental fatigue, confusion, dizziness, loss of appetite, memory loss and neuronal degeneration. The cellular and molecular mechanisms underlying CMS neuropathology is not understood. In the previous study, we demonstrated that neurons derived from CMS patients' fibroblasts have a decreased expression and altered gating properties of voltage-gated sodium channel...
January 17, 2018: Neuroscience
Pan Pan Xia, Lian Jing Li, Run Di Qi, Jiao Jiao Shi, Wei Zhu Ju, Ming Long Chen
OBJECTIVE: Hypertension is a significant risk factor for atrial fibrillation (AF). The role of pulmonary vein (PV) remodeling in the mechanistic association between hypertension and AF is not definitive. In this study, we aimed to identify changes in the electrophysiology and histology in PVs in two-kidney, one-clip (2K1C) hypertensive rats. METHODS: Fifty male Sprague-Dawley rats were classified into the 2K1C and sham-operated groups. The systolic blood pressure was measured every 2 weeks...
January 17, 2018: Anatolian Journal of Cardiology
Ravi Vaidyanathan, Hanora Van Ert, Kazi T Haq, Stefano Morotti, Samuel Esch, Elise C McCune, Eleonora Grandi, Lee L Eckhardt
BACKGROUND: In human cardiac ventricle, IK1 is mainly comprised Kir2.1, but Kir2.2 and Kir2.3 heterotetramers occur and modulate IK1. Long-QT syndrome-9-associated CAV3 mutations cause decreased Kir2.1 current density, but Kir2.x heterotetramers have not been studied. Here, we determine the effect of long-QT syndrome-9-CAV3 mutation F97C on Kir2.x homo- and heterotetramers and model-associated arrhythmia mechanisms. METHODS AND RESULTS: Super-resolution microscopy, co-immunoprecipitation, cellular electrophysiology, on-cell Western blotting, and simulation of Purkinje and ventricular myocyte mathematical models were used...
January 2018: Circulation. Arrhythmia and Electrophysiology
Junghoon Ha, Yu Xu, Takeharu Kawano, Tyler Hendon, Lia Baki, Sumanta Garai, Andreas Papapetropoulos, Ganesh Thakur, Leigh D Plant, Diomedes E Logothetis
Inwardly rectifying potassium (Kir) channels establish and regulate the resting membrane potential of excitable cells in the heart, brain and other peripheral tissues. Phosphatidylinositol 4,5-bisphosphate (PIP2) is a key direct activator of ion channels, including Kir channels. The gasotransmitter carbon monoxide has been shown to regulate Kir channel activity by altering channel-PIP2 interactions.  Here, we tested in two cellular models the effects and mechanism of action of another gasotransmitter, hydrogen sulfide (H2S), thought to play a key role in cellular responses under ischemic conditions...
January 9, 2018: Journal of Biological Chemistry
Cunjin Luo, Kuanquan Wang, Henggui Zhang
A gain-of-function KCNJ2 D172N mutation in KCNJ2-encoded Kir2.1 channels underlies one form of short QT syndrome (SQT3), which is associated with increased susceptibility to arrhythmias and sudden death. Anti-malarial drug chloroquine was reported as an effective inhibitor of Kir2.1 channels. Using biophysically-detailed human ventricle computer models, this study assessed the effects of chloroquine on SQT3. The ten Tusscher et al. model of human ventricular cell action potential was modified to recapitulate functional changes in the inward rectifier K+ current (IK1) due to heterozygous and homozygous forms of the D172N mutation...
December 5, 2017: Oncotarget
Kuihao Chen, Dongchuan Zuo, Zheng Liu, Haijun Chen
Strong inward rectifier K+ channels (Kir2.1) mediate background K+ currents primarily responsible for maintenance of resting membrane potential. Multiple types of cells exhibit two levels of resting membrane potential. Kir2.1 and K2P1 currents counterbalance, partially accounting for the phenomenon of human cardiomyocytes in subphysiological extracellular K+ concentrations or pathological hypokalemic conditions. The mechanism of how Kir2.1 channels contribute to the two levels of resting membrane potential in different types of cells is not well understood...
December 27, 2017: Pflügers Archiv: European Journal of Physiology
M Salih, C M J van Kinschot, R P Peeters, W W de Herder, E J J Duschek, J van der Linden, C van Noord
Thyrotoxic periodic paralysis (TPP) is a complication of hyperthyroidism among Asians, characterised by sudden onset of hypokalaemia and muscle paralysis. Several factors may contribute to a delay in diagnosis, including the subtlety of hyperthyroidism, the transient nature of the events and the rarity of this disease in the West. As life-threatening arrhythmias may occur during an attack, awareness among physicians is necessary for early recognition and treatment. Advances have been made in understanding the pathophysiological mechanism leading to hypokalaemia, which include recently identified mutations of the inwardly rectifying potassium channel Kir2...
October 2017: Netherlands Journal of Medicine
Ya-Jun Gui, Tao Yang, Qiong Liu, Cai-Xiu Liao, Jing-Yuan Chen, Ya-Ting Wang, Jia-Hui Hu, Dan-Yan Xu
Purpose: Soluble epoxide hydrolase inhibitors (sEHIs) had been demonstrated to produce cardioprotective effects against ischemia-induced lethal arrhythmias, but the exact mechanisms remain unknown. The present study was designed to investigate whether the beneficial effects of sEHIs are related to regulation of microRNA-1, which was a proarrhythmic factor in the ischemic heart. Methods: A mousemyocardial infarction (MI) model was established by ligating the coronary artery...
November 7, 2017: Oncotarget
Xu Huang, Si Hyung Lee, Hongli Lu, Kenton M Sanders, Sang Don Koh
KEY POINTS: Interstitial cells of Cajal (ICC) from murine colonic muscles express genes encoding inwardly rectifying K+ channels. Transcripts of Kcnj2 (Kir2.1), Kcnj4 (Kir2.3), Kcnj14 (Kir2.4), Kcnj5 (Kir3.4), Kcnj8 (Kir 6.1) and Kcnj11 (Kir6.2) were found in colonic ICC. A conductance with properties consistent with Kir2 channels was observed in ICC but not in smooth muscle cells (SMC). Despite expression of gene transcripts, G-protein gated K+ channel (Kir3) and KATP (Kir6) currents were not resolved in ICC...
February 1, 2018: Journal of Physiology
Seonil Kim, Jiayi Shou, Sinedu Abera, Edward B Ziff
Dieting induces depression and anxiety among other emotional symptoms. Animal models indicate that repeated access to palatable foods such as sugar induces depression and anxiety-like behavior when the food is no longer available. However, the neurobiological mechanisms of how dietary restriction influences mood have not been fully understood. We used the two-bottle sucrose choice paradigm as an overeating and withdrawal model. Withdrawal after lengthy sucrose overeating elicited depression and anxiety-like behavior, which was reversed by sucrose reinstatement...
March 1, 2018: Neuropharmacology
Raquel G Utrilla, Paloma Nieto-Marín, Silvia Alfayate, David Tinaquero, Marcos Matamoros, Marta Pérez-Hernández, Sandra Sacristán, Lorena Ondo, Raquel de Andrés, F Javier Díez-Guerra, Juan Tamargo, Eva Delpón, Ricardo Caballero
Cardiac Kir2.1 and Nav1.5 channels generate the inward rectifier K+ (IK1 ) and the Na+ (INa ) currents, respectively. There is a mutual interplay between the ventricular INa and IK1 densities, because Nav1.5 and Kir2.1 channels exhibit positive reciprocal modulation. Here we compared some of the biological properties of Nav1.5 and Kir2.1 channels when they are expressed together or separately to get further insights regarding their putative interaction. First we demonstrated by proximity ligation assays (PLAs) that in the membrane of ventricular myocytes Nav1...
2017: Frontiers in Physiology
Yan Bai, Zhenli Su, Hanqi Sun, Wei Zhao, Xue Chen, Pengzhou Hang, Wenliang Zhu, Zhimin Du
BACKGROUND/AIMS: High-fat diet (HFD) causes cardiac electrical remodeling and increases the risk of ventricular arrhythmias. Aloe-emodin (AE) is an anthraquinone component isolated from rhubarb and has a similar chemical structure with emodin. The protective effect of emodin against cardiac diseases has been reported in the literature. However, the cardioprotective property of AE is still unknown. The present study investigated the effect of AE on HFD-induced QT prolongation in rats. METHODS: Adult male Wistar rats were randomly divided into three groups: control, HFD, and AE-treatment groups...
October 20, 2017: Cellular Physiology and Biochemistry
Roselle Gélinas, Nabil El Khoury, Marie-A Chaix, Claudine Beauchamp, Azadeh Alikashani, Nathalie Ethier, Gabrielle Boucher, Louis Villeneuve, Laura Robb, Frédéric Latour, Blandine Mondesert, Lena Rivard, Philippe Goyette, Mario Talajic, Céline Fiset, John David Rioux
BACKGROUND: Long-QT syndrome is a potentially fatal condition for which 30% of patients are without a genetically confirmed diagnosis. Rapid identification of causal mutations is thus a priority to avoid at-risk situations that can lead to fatal cardiac events. Massively parallel sequencing technologies are useful for the identification of sequence variants; however, electrophysiological testing of newly identified variants is crucial to demonstrate causality. Long-QT syndrome could, therefore, benefit from having a standardized platform for functional characterization of candidate variants in the physiological context of human cardiomyocytes...
October 2017: Circulation. Cardiovascular Genetics
Alice A Royal, Andrew Tinker, Stephen C Harmer
The slow delayed-rectifier potassium current (IKs) is crucial for human cardiac action potential repolarization. The formation of IKs requires co-assembly of the KCNQ1 α-subunit and KCNE1 β-subunit, and mutations in either of these subunits can lead to hereditary long QT syndrome types 1 and 5, respectively. It is widely recognised that the KCNQ1/KCNE1 (Q1/E1) channel requires phosphatidylinositol-4,5-bisphosphate (PIP2) binding for function. We previously identified a cluster of basic residues in the proximal C-terminus of KCNQ1 that form a PIP2/phosphoinositide binding site...
2017: PloS One
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"