Cardiac acetylcholinesterase and butyrylcholinesterase have distinct localization and function.

Cholinesterase (ChE) inhibitors are under consideration for use in the treatment of cardiovascular pathologies. A prerequisite to advancing ChE inhibitors into the clinic is their thorough characterization in the heart. The aim here was to provide a detailed analysis of cardiac ChE to understand their molecular composition, localization, and physiological functions.

An α7 nicotinic and GABA receptor-mediated pathway controls acetylcholine release in the tripartite neuromuscular junction.

Terminal Schwann cells (TSCs) are capable of regulating acetylcholine (ACh) release at the neuromuscular junction (NMJ). We have identified GABA as a gliotransmitter at mouse NMJs. When ACh activates α7 nicotinic ACh receptor (nAChRs) on TSCs, GABA is released and activates GABA receptors on the nerve terminal that subsequently reduce ACh release.

Unsupervised classification of plethysmography signals with advanced visual representations.

Ventilation is a simple physiological function that ensures the vital supply of oxygen and the elimination of CO. The recording of the airflow through the nostrils of a mouse over time makes it possible to calculate the position of critical points, based on the shape of the signals, to compute the respiratory frequency and the volume of air exchanged. These descriptors only account for a part of the dynamics of respiratory exchanges.

Unsupervised study of plethysmography signals through DTW clustering.

The study of plethysmography time series is crucial to better understand the breathing behavior of mice, in particular the influence of neurotoxins on the respiratory system. Current approaches rely on a few respiratory descriptors computed on individual breathing cycles that fail to account for the variety of breathing habits and their evolution with time. In this paper we introduce a new procedure for the automatic analysis of plethysmography signals.

Cholinesterases in Tripartite Neuromuscular Synapse.

The neuromuscular junction (NMJ) is a tripartite synapse in which not only presynaptic and post-synaptic cells participate in synaptic transmission, but also terminal Schwann cells (TSC). Acetylcholine (ACh) is the neurotransmitter that mediates the signal between the motor neuron and the muscle but also between the motor neuron and TSC. ACh action is terminated by acetylcholinesterase (AChE), anchored by collagen Q (ColQ) in the basal lamina of NMJs.

Sostdc1 is expressed in all major compartments of developing and adult mammalian eyes.

Purpose: This study was conducted in order to study Sostdc1 expression in rat and human developing and adult eyes.

Methods: Using the yeast signal sequence trap screening method, we identified the Sostdc1 cDNA encoding a protein secreted by the adult rat retinal pigment epithelium. We determined by in situ hybridization, RT-PCR, immunohistochemistry, and western blot analysis Sostdc1 gene and protein expression in developing and postnatal rat ocular tissue sections.

Respiratory failure triggered by cholinesterase inhibitors may involve activation of a reflex sensory pathway by acetylcholine spillover.

Respiration failure during exposure by cholinesterase inhibitors has been widely assumed to be due to inhibition of cholinesterase in the brain. Using a double chamber plethysmograph to measure various respiratory parameters, we observed long "end inspiratory pauses" (EIP) during most exposure that depressed breathing. Surprisingly, Colq KO mice that have a normal level of acetylcholinesterase (AChE) in the brain but a severe deficit in muscles and other peripheral tissues do not pause the breathing by long EIP.

Stoichiometry of the Heteromeric Nicotinic Receptors of the Renshaw Cell.

Neuronal nicotinic acetylcholine receptors (nAChRs) are pentamers built from a variety of subunits. Some are homomeric assemblies of α subunits, others heteromeric assemblies of α and β subunits which can adopt two stoichiometries (2α:3β or 3α:2β). There is evidence for the presence of heteromeric nAChRs with the two stoichiometries in the CNS, but it has not yet been possible to identify them at a given synapse.

The C5 Variant of the Butyrylcholinesterase Tetramer Includes a Noncovalently Bound 60 kDa Lamellipodin Fragment.

Humans with the C5 genetic variant of butyrylcholinesterase (BChE) have 30-200% higher plasma BChE activity, low body weight, and shorter duration of action of the muscle relaxant succinylcholine. The C5 variant has an extra, slow-moving band of BChE activity on native polyacrylamide gel electrophoresis. This band is about 60 kDa larger than wild-type BChE.

A selective and sensitive near-infrared fluorescent probe for acetylcholinesterase imaging.

Two near infra-red (NIR) fluorescent probes HupNIR1 and HupNIR2 based on the huprine scaffold and cyanine 5.0 dye have been synthesised and evaluated in situ for the detection of acetylcholinesterases in different tissues. As anticipated by the initial properties of huprine, both probes displayed a high affinity and selectivity for AChE toward BChE, with IC50 values in the nanomolar range and without any non-specific binding in the tissues.

Slow-binding inhibition of acetylcholinesterase by an alkylammonium derivative of 6-methyluracil: mechanism and possible advantages for myasthenia gravis treatment.

Inhibition of human AChE (acetylcholinesterase) and BChE (butyrylcholinesterase) by an alkylammonium derivative of 6-methyluracil, C-547, a potential drug for the treatment of MG (myasthenia gravis) was studied. Kinetic analysis of AChE inhibition showed that C-547 is a slow-binding inhibitor of type B, i.e.

Monoclonal antibodies to human butyrylcholinesterase reactive with butyrylcholinesterase in animal plasma.

Five mouse anti-human butyrylcholinesterase (BChE) monoclonal antibodies bind tightly to native human BChE with nanomolar dissociation constants. Pairing analysis in the Octet system identified the monoclonal antibodies that bind to overlapping and independent epitopes on human BChE. The nucleotide and amino acid sequences of 4 monoclonal antibodies are deposited in GenBank.

Dysfunctional Presynaptic M2 Receptors in the Presence of Chronically High Acetylcholine Levels: Data from the PRiMA Knockout Mouse.

The muscarinic M2 receptor (M2R) acts as a negative feedback regulator in central cholinergic systems. Activation of the M2 receptor limits acetylcholine (ACh) release, especially when ACh levels are increased because acetylcholinesterase (AChE) activity is acutely inhibited. Chronically high ACh levels in the extracellular space, however, were reported to down-regulate M2R to various degrees.

Comparison of 5 monoclonal antibodies for immunopurification of human butyrylcholinesterase on Dynabeads: KD values, binding pairs, and amino acid sequences.

Human butyrylcholinesterase (HuBChE) is a stoichiometric bioscavenger of nerve agents and organophosphorus pesticides. Mass spectrometry methods detect stable nerve agent adducts on the active site serine of HuBChE. The first step in sample preparation is immunopurification of HuBChE from plasma.

Schwann cells sense and control acetylcholine spillover at the neuromuscular junction by α7 nicotinic receptors and butyrylcholinesterase.

Terminal Schwann cells (TSCs) are key components of the mammalian neuromuscular junction (NMJ). How the TSCs sense the synaptic activity in physiological conditions remains unclear. We have taken advantage of the distinct localization of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at the NMJ to bring out the function of different ACh receptors (AChRs).

An effective solution for capturing the single twitch of muscle: application to monitor muscle relaxation.

In this study, a fast algorithm was developed to capture of train of four and to filter extra contraction and noises. A low pass filter created to filter extra contraction and high frequency noises. Then, a TCA algorithm designed to capturing of the single twitch of muscle.

Optimal detection of cholinesterase activity in biological samples: modifications to the standard Ellman's assay.

Ellman's assay is the most commonly used method to measure cholinesterase activity. It is cheap, fast, and reliable, but it has limitations when used for biological samples. The problems arise from 5,5-dithiobis(2-nitrobenzoic acid) (DTNB), which is unstable, interacts with free sulfhydryl groups in the sample, and may affect cholinesterase activity.

Reassessment of the role of the central cholinergic system.

The central cholinergic system is believed to be involved in the control of many physiological functions and is an important pharmacological target for numerous neurological pathologies. Here, we summarize our recent observations regarding this topic that we obtained by studying genetically modified mice devoid of particular cholinesterase molecular forms. Our results, collected from mice with deficits of functional cholinesterases in the brain, suggest that the increase in the level of acetylcholine (ACh) has an impact on cognition only in the situation when extracellular ACh is low.

Developmental adaptation of central nervous system to extremely high acetylcholine levels.

Acetylcholinesterase (AChE) is a key enzyme in termination of fast cholinergic transmission. In brain, acetylcholine (ACh) is produced by cholinergic neurons and released in extracellular space where it is cleaved by AChE anchored by protein PRiMA. Recently, we showed that the lack of AChE in brain of PRiMA knock-out (KO) mouse increased ACh levels 200-300 times.

Postsynaptic muscarinic m2 receptors at cholinergic and glutamatergic synapses of mouse brainstem motoneurons.

In many brain areas, few cholinergic synapses are identified. Acetylcholine is released into the extracellular space and acts through diffuse transmission. Motoneurons, however, are contacted by numerous cholinergic terminals, indicating synaptic cholinergic transmission on them.

Regulation of acetylcholinesterase activity by nitric oxide in rat neuromuscular junction via N-methyl-D-aspartate receptor activation.

Acetylcholinesterase (AChE) is an enzyme that hydrolyses the neurotransmitter acetylcholine, thereby limiting spillover and duration of action. This study demonstrates the existence of an endogenous mechanism for the regulation of synaptic AChE activity. At the rat extensor digitorum longus neuromuscular junction, activation of N-methyl-d-aspartate (NMDA) receptors by combined application of glutamate and glycine led to enhancement of nitric oxide (NO) production, resulting in partial AChE inhibition.

Monoclonal antibodies to mouse butyrylcholinesterase.

Our immunization strategy introduced recombinant mouse butyrylcholinesterase (BChE) to naïve BChE knockout mice. An extraordinarily strong immune reaction gave rise to a whole spectrum of antibodies with different properties. Two selective and highly efficient monoclonal anti-mouse BChE antibodies 4H1 (IgG1) and 4 C9 (IgG2a), with Kd values in the nanomolar range were generated.

Specific binding of collagen Q to the neuromuscular junction is exploited to cure congenital myasthenia and to explore bases of myasthenia gravis.

Acetylcholinesterase (AChE) at the neuromuscular junction (NMJ) is anchored to the synaptic basal lamina via a triple helical collagen Q (ColQ) in the form of asymmetric AChE (AChE/ColQ). The C-terminal domain of ColQ binds to MuSK, the muscle-specific receptor tyrosine kinase, that mediates a signal for acetylcholine receptor (AChR) clustering at the NMJ. ColQ also binds to heparan sulfate proteoglycans including perlecan.

Near-complete adaptation of the PRiMA knockout to the lack of central acetylcholinesterase.

Acetylcholinesterase (AChE) rapidly hydrolyzes acetylcholine. At the neuromuscular junction, AChE is mainly anchored in the extracellular matrix by the collagen Q, whereas in the brain, AChE is tethered by the proline-rich membrane anchor (PRiMA). The AChE-deficient mice, in which AChE has been deleted from all tissues, have severe handicaps.