Search results for "Acetyltransferase"
showing 10 items of 170 documents
Cigarette smoke extract activates human bronchial epithelial cells affecting non-neuronal cholinergic system signalling in vitro.
2010
Abstract Aims Acetylcholine (ACh) is synthesized by Choline Acetyl-Transferase (ChAT) that exerts its physiological effects in airway epithelial cells via muscarinic receptor (MR) activation. We evaluate the effect of ACh stimulation on human bronchial epithelial cells (16-HBE) and test whether cigarette smoke extract (CSE) can modify the basal cellular response to ACh affecting the non-neuronal cholinergic system signalling. Main methods ACh stimulated 16-HBE were tested for ACh-binding, Leukotriene B 4 (LTB 4 ) release and ERK1/2 and NFkB pathway activation. Additionally, we investigated all the aforementioned parameters as well as ChAT and MR proteins and mRNA expression and endogenous A…
The phototransduction cascade in the isolated chick pineal gland revisited.
2003
It is well established that the isolated chick pineal gland is directly light sensitive and that melatonin synthesis of the gland can be inhibited by exposing the gland to light during scotophase. Since not all the steps of the phototransduction cascade have been clarified to the same extent as in the retina, we have treated isolated chick pineal glands with 90 min of light during scotophase and with drugs that affect key-components of vertebrate phototransduction, i.e., cyclic guanosine monophosphate (cGMP) phosphodiesterase 6 (PDE6), cGMP levels and cGMP-gated calcium channels. The endpoint measured was the activity of the rate-limiting enzyme of melatonin synthesis, arylalkylamine N-acet…
Release of non-neuronal acetylcholine from the human placenta: difference to neuronal acetylcholine
2001
The synthesis and release of non-neuronal acetylcholine, a widely expressed signaling molecule, were investigated in the human placenta. This tissue is free of cholinergic neurons, i.e. a contamination of neuronal acetylcholine can be excluded. The villus showed a choline acetyltransferase (ChAT) activity of 0.65 nmol/mg protein per h and contained 500 nmol acetylcholine/g dry weight. In the absence of cholinesterase inhibitors the release of acetylcholine from isolated villus pieces amounted to 1.3 nmol/g wet weight per 10 min corresponding to a fractional release rate of 0.13% per min. The following substances did not significantly modify the release of acetylcholine: oxotremorine (1 micr…
The non-neuronal cholinergic system in humans: expression, function and pathophysiology.
2003
Acetylcholine, a prime example of a neurotransmitter, has been detected in bacteria, algae, protozoa, and primitive plants, indicating an extremely early appearance in the evolutionary process (about 3 billion years). In humans, acetylcholine and/or the synthesizing enzyme, choline acetyltransferase (ChAT), have been found in epithelial cells (airways, alimentary tract, urogenital tract, epidermis), mesothelial (pleura, pericardium), endothelial, muscle and immune cells (mononuclear cells, granulocytes, alveolar macrophages, mast cells). The widespread expression of non-neuronal acetylcholine is accompanied by the ubiquitous presence of cholinesterase and receptors (nicotinic, muscarinic). …
Cigarette smoke alters non-neuronal cholinergic system components inducing MUC5AC production in the H292 cell line.
2013
Abstract Cigarette smoke extract (CSE) affects the expression of Choline Acetyl-Transferase (ChAT), muscarinic acetylcholine receptors, and mucin production in bronchial epithelial cells. Mucin 5AC (MUC5AC), muscarinic acetylcholine receptor M3, ChAT expression, acetylcholine levels and acetylcholine binding were measured in a human pulmonary mucoepidermoid carcinoma cell line (H292) stimulated with CSE. We performed ChAT/RNA interference experiments in H292 cells stimulated with CSE to study the role of ChAT/acetylcholine in MUC5AC production. The effects of Hemicholinium-3 (HCh-3) (50 μM) (a potent and selective choline uptake blocker) and Tiotropium bromide (Spiriva ® ) (100 nM), alone o…
Neurochemistry of identified motoneurons of the tensor tympani muscle in rat middle ear
2008
The objective of the present study was to identify efferent and afferent transmitters of motoneurons of the tensor tympani muscle (MoTTM) to gain more insight into the neuronal regulation of the muscle. To identify MoTTM, we injected the fluorescent neuronal tracer Fluoro-Gold (FG) into the muscle after preparation of the middle ear in adult rats. Upon terminal uptake and retrograde neuronal transport, we observed FG in neurons located lateral and ventrolateral to the motor trigeminal nucleus ipsilateral to the injection site. Immunohistochemical studies of these motoneurons showed that apparently all contained choline acetyltransferase, demonstrating their motoneuronal character. Different…
Chick embryo retina development in vitro: the effect of insulin.
1995
In this paper we study the development of chick embryo retina cultured in vitro and the effects exerted by insulin. Retinas were removed from 7-day embryos and cultured in serum- and hormone-free medium for 7 additional days. Under these conditions retinal cells survived and underwent cholinergic differentiation, as previously ascertained by Hausman et al. (Dev. Brain Res., 1991, 59: 31-37). However, a great retardation of development was noted compared to uncultured control, 14-day retina. In fact both wet weight and DNA and protein content increased much slower than in ovo and the tubulin content decreased below even the starting value. In addition, although after 7 days in culture retina…
The histone acetyltransferase MOF activates hypothalamic polysialylation to prevent diet-induced obesity in mice
2014
Overfeeding causes rapid synaptic remodeling in hypothalamus feeding circuits. Polysialylation of cell surface molecules is a key step in this neuronal rewiring and allows normalization of food intake. Here we examined the role of hypothalamic polysialylation in the long-term maintenance of body weight, and deciphered the molecular sequence underlying its nutritional regulation. We found that upon high fat diet (HFD), reduced hypothalamic polysialylation exacerbated the diet-induced obese phenotype in mice. Upon HFD, the histone acetyltransferase MOF was rapidly recruited on the St8sia4 polysialyltransferase-encoding gene. Mof silencing in the mediobasal hypothalamus of adult mice prevented…
Comprehensive analysis of interacting proteins and genome-wide location studies of the Sas3-dependent NuA3 histone acetyltransferase complex
2014
Highlights • We characterise Sas3p and Gcn5p active HAT complexes in WT and deleted TAP-strains. • We confirm that Pdp3p interacts with NuA3, histones and chromatin regulators. • Pdp3p MS-analysis reveals its phosphorylation, ubiquitination and methylation. • Sas3p can substitute Gcn5p in acetylation of histone H3K14 but not of H3K9. • Genome-wide profiling of Sas3p supports its involvement in transcriptional elongation.