State-Dependent Inhibition of Nav1.8 Sodium Channels by VX-150 and VX-548.

Nav1.8 sodium channels (Nav1.8) are an attractive therapeutic target for pain because they are prominent in primary pain-sensing neurons with little expression in most other kinds of neurons.

A Kv2 inhibitor combination reveals native neuronal conductances consistent with Kv2/KvS heteromers.

KvS proteins are voltage-gated potassium channel subunits that form functional channels when assembled into heterotetramers with Kv2.1 ( ) or Kv2.2 ( ).

C-C Motif Chemokine Receptor 3-Mediated Extracellular Signal-Regulated Kinase 1/2 and p38 Mitogen-Activated Protein Kinase Signaling: Promising Targets for Human Airway Epithelial Mucin 5AC Induction by Eotaxin-2 and Eotaxin-3.

Introduction: Eotaxin-2 and -3 of the C-C chemokine subfamily function as potent chemoattractant factors for eosinophil recruitment and various immune responses in allergic and inflammatory airway diseases. Mucin 5AC (MUC5AC), a major gel-forming secretory mucin, is overexpressed in airway inflammation. However, the association between mucin secretion and eotaxin-2/3 expression in the upper and lower airway epithelial cells has not been fully elucidated.

Cannabidiol inhibits Na channels through two distinct binding sites.

Cannabidiol (CBD), a major non-psychoactive phytocannabinoid in cannabis, is an effective treatment for some forms of epilepsy and pain. At high concentrations, CBD interacts with a huge variety of proteins, but which targets are most relevant for clinical actions is still unclear. Here we show that CBD interacts with Na1.

Scanning mutagenesis of the voltage-gated sodium channel Na1.2 using base editing.

It is challenging to apply traditional mutational scanning to voltage-gated sodium channels (Nas) and functionally annotate the large number of coding variants in these genes. Using a cytosine base editor and a pooled viability assay, we screen a library of 368 guide RNAs (gRNAs) tiling Na1.2 to identify more than 100 gRNAs that change Na1.

Scalable generation of sensory neurons from human pluripotent stem cells.

Development of new non-addictive analgesics requires advanced strategies to differentiate human pluripotent stem cells (hPSCs) into relevant cell types. Following principles of developmental biology and translational applicability, here we developed an efficient stepwise differentiation method for peptidergic and non-peptidergic nociceptors. By modulating specific cell signaling pathways, hPSCs were first converted into SOX10 neural crest, followed by differentiation into sensory neurons.

Use-Dependent Relief of Inhibition of Nav1.8 Channels by A-887826.

Sodium channel inhibitors used as local anesthetics, antiarrhythmics, or antiepileptics typically have the property of use-dependent inhibition, whereby inhibition is enhanced by repetitive channel activation. For targeting pain, Nav1.8 channels are an attractive target because they are prominent in primary pain-sensing neurons, with little or no expression in most other kinds of neurons, and a number of Nav1.

Saponin attenuates diesel exhaust particle (DEP)-induced MUC5AC expression and pro-inflammatory cytokine upregulation via TLR4/TRIF/NF-κB signaling pathway in airway epithelium and ovalbumin (OVA)-sensitized mice.

Background: Diesel exhaust particle (DEP) is a harmful kind of particulate matter known to exacerbate pre-existing respiratory diseases. Although their adverse effects on airway pathologies have been widely studied, the mechanistic analysis of signaling pathways and potential targets in reducing DEP-induced mucin secretion and pro-inflammatory cytokine production remain elusive. We, for the first time, investigated the effects of Korean Red Ginseng (KRG) extracts on mucin overproduction and airway inflammation induced by DEP.

Cannabidiol activates neuronal Kv7 channels.

Cannabidiol (CBD), a chemical found in the plant, is a clinically effective antiepileptic drug whose mechanism of action is unknown. Using a fluorescence-based thallium flux assay, we performed a large-scale screen and found enhancement of flux through heterologously expressed human Kv7.2/7.

Developing nociceptor-selective treatments for acute and chronic pain.

Despite substantial efforts dedicated to the development of new, nonaddictive analgesics, success in treating pain has been limited. Clinically available analgesic agents generally lack efficacy and may have undesirable side effects. Traditional target-based drug discovery efforts that generate compounds with selectivity for single targets have a high rate of attrition because of their poor clinical efficacy.

Inhibition of inflammatory pain and cough by a novel charged sodium channel blocker.

Background And Purpose: Many pain-triggering nociceptor neurons express TRPV1 or TRPA1, cation-selective channels with large pores that enable permeation of QX-314, a cationic analogue of lidocaine. Co-application of QX-314 with TRPV1 or TRPA1 activators can silence nociceptors. In this study, we describe BW-031, a novel more potent cationic sodium channel inhibitor, and test whether its application alone can inhibit pain associated with tissue inflammation and whether this strategy can also inhibit cough.

Lidocaine Binding Enhances Inhibition of Nav1.7 Channels by the Sulfonamide PF-05089771.

PF-05089771 is an aryl sulfonamide Nav1.7 channel blocker that binds to the inactivated state of Nav1.7 channels with high affinity but binds only weakly to channels in the resting state.

Novel charged sodium and calcium channel inhibitor active against neurogenic inflammation.

Voltage-dependent sodium and calcium channels in pain-initiating nociceptor neurons are attractive targets for new analgesics. We made a permanently charged cationic derivative of an N-type calcium channel-inhibitor. Unlike cationic derivatives of local anesthetic sodium channel blockers like QX-314, this cationic compound inhibited N-type calcium channels more effectively with extracellular than intracellular application.

Can we predict when to start renal replacement therapy in patients with chronic kidney disease using 6 months of clinical data?

Purpose: We aimed to develop a model of chronic kidney disease (CKD) progression for predicting the probability and time to progression from various CKD stages to renal replacement therapy (RRT), using 6 months of clinical data variables routinely measured at healthcare centers.

Methods: Data were derived from the electronic medical records of Ajou University Hospital, Suwon, South Korea from October 1997 to September 2012. We included patients who were diagnosed with CKD (estimated glomerular filtration rate [eGFR] < 60 mL·min-1·1.

Lacosamide Inhibition of Nav1.7 Voltage-Gated Sodium Channels: Slow Binding to Fast-Inactivated States.

Lacosamide is an antiseizure agent that targets voltage-dependent sodium channels. Previous experiments have suggested that lacosamide is unusual in binding selectively to the slow-inactivated state of sodium channels, in contrast to drugs like carbamazepine and phenytoin, which bind tightly to fast-inactivated states. Using heterologously expressed human Nav1.

Sidedness of carbamazepine accessibility to voltage-gated sodium channels.

Voltage-gated sodium channels are inhibited by many local anesthetics, antiarrhythmics, and antiepileptic drugs. The local anesthetic lidocaine appears to be able to access its binding site in the sodium channel only from the membrane phase or from the internal face of the channel. In contrast, the antiepileptic drug carbamazepine was found to inhibit voltage-gated sodium channels only with external, but not internal, application, implying a major difference.

Modulation of neuronal sodium channels by the sea anemone peptide BDS-I.

Blood-depressing substance I (BDS-I), a 43 amino-acid peptide from sea anemone venom, is used as a specific inhibitor of Kv3-family potassium channels. We found that BDS-I acts with even higher potency to modulate specific types of voltage-dependent sodium channels. In rat dorsal root ganglion (DRG) neurons, 3 μM BDS-I strongly enhanced tetrodotoxin (TTX)-sensitive sodium current but weakly inhibited TTX-resistant sodium current.

Inhibition of neuronal voltage-gated sodium channels by brilliant blue G.

Brilliant blue G (BBG), best known as an antagonist of P2X7 receptors, was found to inhibit voltage-gated sodium currents in N1E-115 neuroblastoma cells. Sodium currents elicited from a holding potential of -60 mV were blocked with an IC(50) of 2 μM. Block was enhanced in a use-dependent manner at higher stimulation rates.

Functional modulation of AMP-activated protein kinase by cereblon.

Mutations in cereblon (CRBN), a substrate binding component of the E3 ubiquitin ligase complex, cause a form of mental retardation in humans. However, the cellular proteins that interact with CRBN remain largely unknown. Here, we report that CRBN directly interacts with the α1 subunit of AMP-activated protein kinase (AMPK α1) and inhibits the activation of AMPK activation.

Induction of cereblon by NF-E2-related factor 2 in neuroblastoma cells exposed to hypoxia-reoxygenation.

Cereblon is a protein encoded by the CRBN gene, which has been associated with human autosomal recessive nonsyndromic mental retardation. However, little is known about the regulation of CRBN expression. Following exposure of mouse neuroblastoma N2A cells to hypoxia/reoxygenation (H/R), mRNA and protein expression of CRBN were increased.

Myelin basic protein as a binding partner and calmodulin adaptor for the BKCa channel.

The activity and localization of large-conductance Ca2+ -activated K+ (BKCa) channels are known to be modulated by several different proteins. Although many binding partners have been identified via yeast two-hybrid screening, this method may not detect certain classes of interacting proteins such as low affinity binding proteins or multi-component protein complexes. In this study, we employed mass spectrometry to identify proteins that interact with BKCa channels.

Establishment of an assay for P2X7 receptor-mediated cell death.

The P2X7 receptor, an ATP-gated cation channel, induces cell death in immune cells and is involved in neurodegenerative diseases. Although the receptor plays various roles in these diseases, the cellular mechanisms involved are poorly understood and antagonists are limited. Here, the development of a cell-based assay for human P2X7 receptor is reported.

Identification and functional characterization of cereblon as a binding protein for large-conductance calcium-activated potassium channel in rat brain.

Large-conductance Ca2+-activated K+ (BK(Ca)) channels are activated by membrane depolarization and modulated by intracellular Ca2+. Here, we report the direct interaction of cereblon (CRBN) with the cytosolic carboxy-terminus of the BK(Ca) channel alpha subunit (Slo). Rat CRBN contained the N-terminal domain of the Lon protease, a 'regulators of G protein-signaling' (RGS)-like domain, a leucine zipper (LZ) motif, and four putative protein kinase C (PKC) phosphorylation sites.