Tuft cell acetylcholine is released into the gut lumen to promote anti-helminth immunity.

Upon parasitic helminth infection, activated intestinal tuft cells secrete interleukin-25 (IL-25), which initiates a type 2 immune response during which lamina propria type 2 innate lymphoid cells (ILC2s) produce IL-13. This causes epithelial remodeling, including tuft cell hyperplasia, the function of which is unknown. We identified a cholinergic effector function of tuft cells, which are the only epithelial cells that expressed choline acetyltransferase (ChAT).

Characterization of social behavior in young and middle-aged ChAT-IRES-Cre mouse.

The cholinergic system is an important modulator of brain processes. It contributes to the regulation of several cognitive functions and emotional states, hence altering behaviors. Previous works showed that cholinergic (nicotinic) receptors of the prefrontal cortex are needed for adapted social behaviors.

Acetylcholine production by group 2 innate lymphoid cells promotes mucosal immunity to helminths.

Innate lymphoid cells (ILCs) are critical mediators of immunological and physiological responses at mucosal barrier sites. Whereas neurotransmitters can stimulate ILCs, the synthesis of small-molecule neurotransmitters by these cells has only recently been appreciated. Group 2 ILCs (ILC2s) are shown here to synthesize and release acetylcholine (ACh) during parasitic nematode infection.

Hyperfunction of muscarinic receptor maintains long-term memory in 5-HT4 receptor knock-out mice.

Patients suffering from dementia of Alzheimer's type express less serotonin 4 receptors (5-HTR(4)), but whether an absence of these receptors modifies learning and memory is unexplored. In the spatial version of the Morris water maze, we show that 5-HTR(4) knock-out (KO) and wild-type (WT) mice performed similarly for spatial learning, short- and long-term retention. Since 5-HTR(4) control mnesic abilities, we tested whether cholinergic system had circumvented the absence of 5-HTR(4).

Silencing of choline acetyltransferase expression by lentivirus-mediated RNA interference in cultured cells and in the adult rodent brain.

RNA interference (RNAi) is a potent mechanism for local silencing of gene expression and can be used to study loss-of-function phenotypes in mammalian cells. We used RNAi to knockdown specifically the expression of choline acetyltransferase (ChAT), the enzyme of acetylcholine biosynthesis, both in cultured cells and in the adult brain. We first identified a 19-nucleotide sequence in the coding region of rat and mouse ChAT transcripts that constitutes a target for potent silencing of ChAT expression by RNAi.

Sodium butyrate modifies the stabilizing complexes of tyrosine hydroxylase mRNA.

Multiple mechanisms regulate the expression of the tyrosine hydroxylase (Th) gene, which encodes the rate-limiting enzyme in the biosynthesis of catecholamines. Sodium butyrate (SOB), a physiological histone deacetylase (HDAC) inhibitor, was reported to stimulate the Th gene promoter activity in reporter gene assays. However, the expression of the endogenous Th gene in PC12 cells was reported to be either stimulated or inhibited by SOB.

Differential expression and regulation of the high-affinity choline transporter CHT1 and choline acetyltransferase in neurons of superior cervical ganglia.

Previous studies revealed that leukemia inhibitory factor (LIF) and retinoic acid (RA) induce a noradrenergic to cholinergic switch in cultured sympathetic neurons of superior cervical ganglia (SCG) by up-regulating the coordinate expression of choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter. Here, we examined the effect of both factors on high-affinity choline uptake (HACU) and on expression of the high-affinity choline transporter CHT1. We found that HACU and CHT1-mRNA levels are up-regulated by LIF and down-regulated by RA in these neurons.

Quantification of transcriptional activities of reporter gene constructs in primary cultures of sympathetic neurons.

Primary cultures of sympathetic neurons provide an attractive cellular model for investigating the mechanisms of neurotransmitter phenotypic plasticity. However, it has not been possible to transfect these neurons by conventional techniques, and this has been a major impediment to molecular investigations of neuronal gene expression in this system. Here, reporter plasmids were transferred into the nuclei of cultured sympathetic neurons by microinjection.

More than one way to toy with ChAT and VAChT.

Expression of choline acetyltransferase (ChAT) and of the vesicular acetylcholine transporter (VAChT) is required for the acquisition and the maintenance of the cholinergic phenotype. The ChAT and VAChT genes have been demonstrated to share a common gene locus and this suggests a coordinate regulation of their expression. In the present work, we examined the effects of several differentiating treatments on the modulation of ChAT and VAChT expression at the mRNA and protein levels in growing and differentiating NG108-15 cells.

Is RE1/NRSE a common cis-regulatory sequence for ChAT and VAChT genes?

Choline acetyltransferase (ChAT), the biosynthetic enzyme of acetylcholine, and the vesicular acetylcholine transporter (VAChT) are both required for cholinergic neurotransmission. These proteins are encoded by two embedded genes, the VAChT gene lying within the first intron of the ChAT gene. In the nervous system, both ChAT and VAChT are synthesized only in cholinergic neurons, and it is therefore likely that the cell type-specific expression of their genes is coordinately regulated.

The cholinergic locus: ChAT and VAChT genes.

The gene encoding the vesicular acetylcholine transporter has been localized within the first intron of the gene encoding choline acetyltransferase and is in the same transcriptional orientation. These two genes, whose products are required for the expression of the cholinergic phenotype, could therefore be coregulated. The promoters of both genes have been identified.

Specific vesicular acetylcholine transporter promoters lie within the first intron of the rat choline acetyltransferase gene.

The sequence encoding the vesicular acetylcholine transporter (VAChT) has recently been localized within the first intron of the choline acetyltransferase (ChAT) gene in various species. In rat, we previously identified a class of VAChT mRNAs that may originate from the same promoter region as two ChAT mRNAs. Here, we demonstrate by a detailed analysis of the 5'-noncoding region of the VAChT gene, that two specific VAChT promoters lie within the first intron of the ChAT gene.

Coregulation of two embedded gene products, choline acetyltransferase and the vesicular acetylcholine transporter.

The gene encoding the vesicular acetylcholine transporter (VAChT) has recently been localized within the first intron of the gene encoding choline acetyltransferase (ChAT) and is in the same transcriptional orientation. These two genes, whose products are required for the expression of the cholinergic phenotype, could therefore be coregulated. We thus tested the effects on VAChT gene expression of the cholinergic differentiation factor/leukemia inhibitory factor and retinoic acid, both of which induce ChAT activity and increase ChAT mRNA levels in cultured sympathetic neurons.

A unique gene organization for two cholinergic markers, choline acetyltransferase and a putative vesicular transporter of acetylcholine.

Choline acetyltransferase (ChAT) is the biosynthetic enzyme of acetylcholine. In mammalian tissues, it is encoded by multiple mRNAs with different 5'-ends. This diversity results from the alternative usage of three promoters and from differential splicing events.

Regulation by CDF/LIF and retinoic acid of multiple ChAT mRNAs produced from distinct promoters.

The cholinergic differentiation factor/leukaemia inhibitory factor (CDF/LIF) and retinoic acid (RA) induce in sympathetic neurones, a switch from the noradrenergic to the cholinergic neurotransmitter phenotype. In particular, these molecules alter the activities of the biosynthetic enzymes choline acetyltransferase (ChAT), tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH). Recently, five rat ChAT mRNA species have been identified although no data have yet been reported concerning their production and regulation in sympathetic neurones.

Retinoic acid induces cholinergic differentiation of cultured newborn rat sympathetic neurons.

Many studies provide evidence that retinoic acid (RA), an endogenous derivative of vitamin A, plays a role in the development of the nervous system. We now report that RA controls the neurotransmitter phenotype of post-mitotic rat sympathetic neurons in cell culture. RA added to the culture medium increased the specific activity of choline acetyltransferase (ChAT) and the level of acetylcholine (ACh).

An adenovirus vector for gene transfer into neurons and glia in the brain.

The efficient introduction of genetic material into quiescent nerve cells is important in the study of brain function and for gene therapy of neurological disorders. A replication-deficient adenoviral vector that contained a reporter gene encoding beta-galactosidase infected rat nerve cells in vitro and in vivo. beta-Galactosidase was expressed in almost all sympathetic neurons and astrocytes in culture.

Tyrosine hydroxylase regulation in neurotransmission and neuroplasticity.

The modulation of neurotransmitter synthesis is a fundamental mechanism influencing neurotransmission and neuronal plasticity during development. The regulation of the tyrosine hydroxylase (TH) has been used to elucidate specific adaptative responses in neurons. Trans-synaptic impulse activity elicits sort- and long-term changes in the activity of TH.

Promoter elements of the rat choline acetyltransferase gene allowing nerve growth factor inducibility in transfected primary cultured cells.

Choline acetyltransferase, the enzyme responsible for the synthesis of acetylcholine, provides a convenient index for cholinergic neurons. Using a previously identified rat cDNA clone, we have isolated several corresponding genomic clones and have characterized a 1,902-bp fragment that contains part of the first noncoding exon as well as promoter sequences. The promoter activity of this fragment was tested, taking advantage of the recently developed lipopolyamine-mediated DNA transfer method, which allows transfection of primary neurons.