The basolateral amygdala (BLA) receives dense projections from cholinergic neurons of the basal forebrain. Acetylcholine can contributes to amygdala-dependent behaviors: formation and extinction of fear memory and appetitive instrumental learning. However, the cholinergic mechanism at the circuit level has not been defined yet. We demonstrated that cholinergic-induced di-synaptic inhibition of BLA pyramidal neurons exhibits a retrograde form of short-term synaptic inhibition, depolarization-induced suppression of inhibition (DSI). Activation of nicotinic receptors was sufficient to evoke action potentials in cholecystokinin (CCK)-positive inhibitory neurons, which strongly inhibit pyramidal neurons through their perisomatic synapses. Our cell type-specific monosynaptic retrograde tracing also revealed that CCK neurons are innervated by basal forebrain cholinergic neurons. Therefore, our data indicated that CCK inhibitory neurons mediate the cholinergic-induced di-synaptic inhibition of BLA pyramidal neurons.
Acetylcholine ; Action Potentials ; Basal Forebrain ; Basolateral Nuclear Complex ; Cholecystokinin ; Cholinergic Neurons ; Conditioning, Operant ; Iontophoresis ; Memory ; Neurons ; Pyramidal Cells ; Receptors, Nicotinic ; Synapses

This study aimed to elucidate the effect of tryptophan (Trp) on gut hormone secretion as well as the roles of the calcium-sensing receptor (CaSR) and its downstream signaling pathway in gut hormone secretion by assessing swine duodenal perfusion in vitro. Swine duodenum was perfused with Krebs-Henseleit buffer as a basal solution. Various concentrations (0, 10, and 20 mM) of Trp were applied to investigate its effect on gut hormone secretion. A CaSR antagonist was used to detect the involvement of CaSR and its signal molecules. The 20 mM Trp concentration promoted the secretion of cholecystokinin (CCK) and glucose-dependent insulinotropic peptide (GIP), elevated the mRNA level of CaSR, and upregulated the protein levels of CaSR, protein kinase C (PKC), and inositol trisphosphate receptor (IP3R). However, NPS 2143, an inhibitor of CaSR, attenuated the CCK and GIP release, reduced the mRNA level of CaSR, and decreased the protein levels of CaSR, PKC, and IP3R with 20 mM Trp perfusion. The results indicate that CCK and GIP secretion can be induced by Trp in swine duodenum in vitro, and the effect is mediated by CaSR and its downstream signal molecules PKC and IP3R.
Cholecystokinin ; Duodenum ; Gastric Inhibitory Polypeptide ; In Vitro Techniques ; Inositol ; Perfusion ; Protein Kinase C ; Receptors, Calcium-Sensing ; RNA, Messenger ; Swine ; Tryptophan

Photodynamic action, due to the rather limited lifetime (1 μs) and effective reactive distance of singlet oxygen (< 10 nm), could subcellular-specifically regulate different cellular functions. Photodynamic action could activate permanently cholecystokinin (CCK) 1 receptors, and sensitize or desensitize other G protein-coupled receptors. The emergence in recent years of genetically- encoded protein photosensitisers has enabled more precisely-targeted photodynamic modulation of subcellular organelles and functional proteins. Protein photosensitisers (such as KillerRed, miniSOG or SOPP) expressed on the plasma membrane, mitochondria, lysosomes or endoplasmic reticulum can modulate photodynamically subcellular functions and fine-tune protein activity by targeted photooxidation. With the newly emerged active illumination technique, simultaneous photodynamic action localized at multiple sites is now possible, and the contribution of subcellular regions to the whole cell or individual cells to a cell cluster could be quantitated. Photodynamic action with protein photosensitiser will be a powerful tool for nano-manipulation in cell physiology research.
Endoplasmic Reticulum ; Light ; Mitochondria ; Photosensitizing Agents ; Receptors, Cholecystokinin

<b>OBJECTIVEb>To investigate the effect of Chaiqin Chengqi Decoction (,CQCQD) on cholecystokinin receptor 1 (CCKR1)-mediated signal transduction of pancreatic acinar cell in rats with acute necrotic pancreatitis (ANP).

<b>METHODSb>Twenty-seven Sprague-Dawley rats were randomized into three groups: the control group, the ANP group, and the CQCQD group (9 in each group). ANP rats were induced by two intraperitoneal injections of 8% L-arginine (pH=7.0, 4.4 g/kg) over a 2-h period. Rats were treated with 1.5 mL/100 g body weight of CQCQD (CQCQD group) or physiological saline (control and ANP groups) at 2 h interval. And 6 h after induction, pancreatic tissues were collected for histopathological examination. Pancreatic acinar cells were isolated for determination of CCKR1 mRNA and protein expression, phospholipase C (PLC) and inositol-1,4,5-triphosphate (IP3), and determination of fluorescence intensity (FI) as a measure of intracellular calcium ion concentration [Ca(2+)]i.

<b>RESULTSb>The pancreatic histopathological score (6.2 ± 1.1) and the levels of PLC (1,187.2 ± 228.2 μg/mL) and IP3 (872.2 ± 88.4 μg/mL) of acinar cells in the ANP group were higher than those in the control (2.8 ± 0.4, 682.5 ± 121.8 μg/mL, 518.4 ± 115.8 μg/mL) and the CQCQD (3.8 ± 0.8, 905.3 ± 78.5 μg/mL, 611.0 ± 42.5 μg/mL) groups (P<0.05). [Ca(2+)]i FI for the ANP group (34.8±27.0) was higher than that in the control (5.1 ± 2.2) and CQCQD (12.6 ± 2.5) groups (P<0.05). The expression of pancreatic acinar cell CCKR1 mRNA in the ANP group was up-regulated (expression ratio=1.761; P=0.024) compared with the control group. The expression of pancreatic acinar cell CCKR1 mRNA in the CQCQD group was down-regulated (expression ratio=0.311; P=0.035) compared with the ANP group. The ratio of gray values of the CCKR1 and β-actin in the ANP group (1.43 ± 0.17) was higher than those in the control (0.70 ± 0.15) and CQCQD (0.79 ± 0.11) groups (P<0.05).

<b>CONCLUSIONSb>Pancreatic acinar cell calcium overload of ANP induced by L-arginine was related to the up-regulated expressions of pancreatic acinar cell CCKR1 mRNA and protein. CQCQD can down-regulate expressions of pancreatic acinar cell CCKR1 mRNA and protein to reduce the PLC and IP3 of pancreatic acinar cells, relieving the calcium overload and reducing the pathological changes in rats with ANP.

Acinar Cells ; drug effects ; metabolism ; Animals ; Blotting, Western ; Calcium ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Fluorescence ; Gene Expression Regulation ; drug effects ; Inositol 1,4,5-Trisphosphate ; metabolism ; Pancreas ; pathology ; Pancreatitis, Acute Necrotizing ; drug therapy ; pathology ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley ; Receptors, Cholecystokinin ; genetics ; metabolism ; Signal Transduction ; drug effects ; Type C Phospholipases ; metabolism

<b>OBJECTIVEb>To find the risk loci on cholecystokinin A receptor gene (CCKAR) - a schizophrenia candidate gene by using the deep sequencing and then analyze the variations.

<b>METHODSb>In the present study, 8 schizophrenia patients and 8 healthy controls were recruited. After DNA extraction from peripheral blood, we conducted deep sequencing on CCKAR region by HaloPlex Target Enrichment System (Agilent). We used Unphased software to exclude the false positive.

<b>RESULTSb>After deep sequencing, we got 103 loci, among which 30 were located in CCKAR gene. Besides, the SNP rs191275118 was found to be associated with schizophrenia.

<b>CONCLUSIONSb>A new variation that may be associated with schizophrenia was found. The deep sequencing is effective to find genetic variation.

Adult ; Case-Control Studies ; Female ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Receptor, Cholecystokinin A ; genetics ; Schizophrenia ; genetics ; Sequence Analysis, DNA

Fenofibrate is a selective peroxisome proliferator-activated receptor alpha (PPARalpha) activator and is prescribed to treat hyperlipidemia. The mechanism through which PPARalpha agonists reduce food intake, body weight, and adiposity remains unclear. One explanation for the reduction of food intake is that fenofibrate promotes fatty acid oxidation and increases the production of ketone bodies upon a standard experimental dose of the drug (100~300 mg/kg/day). We observed that low-dose treatment of fenofibrate (30 mg/kg/day), which does not cause significant changes in ketone body synthesis, reduced food intake in Long-Evans Tokushima (LETO) rats. LETO rats are the physiologically normal controls for Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which are obese and cholecystokinin (CCK)-A receptor deficient. We hypothesized that the reduced food intake by fenofibrate-treated LETO rats may be associated with CCK production. To investigate the anorexic effects of fenofibrate in vivo and to determine whether CCK production may be involved, we examined the amount of food intake and CCK production. Fenofibrate-treated OLETF rats did not significantly change their food intake while LETO rats decreased their food intake. Treatment of fenofibrate increased CCK synthesis in the duodenal epithelial cells of both LETO and OLETF rats. The absence of a change in the food intake of OLETF rats, despite the increase in CCK production, may be explained by the absence of CCK-A receptors. Contrary to the OLETF rats, LETO rats, which have normal CCK receptors, presented a decrease in food intake and an increase in CCK production. These results suggest that reduced food intake by fenofibrate treatment may be associated with CCK production.
Adiposity ; Animals ; Body Weight ; Cholecystokinin ; Diethylpropion ; Eating ; Epithelial Cells ; Fenofibrate ; Hyperlipidemias ; Ketone Bodies ; PPAR alpha ; Rats ; Rats, Inbred OLETF ; Receptor, Cholecystokinin A ; Receptors, Cholecystokinin

The paradigm for the control of feeding behavior has changed significantly. In this review, we present evidence that the separation of function in which cholecystokinin (CCK) controls short-term food intake and leptin regulate long-term eating behavior and body weight become less clear. In addition to the hypothalamus, the vagus nerve is critically involved in the control of feeding by transmitting signals arising from the upper gut to the nucleus of the solitary tract. Among the peripheral mediators, CCK is the key peptide involved in generating the satiety signal via the vagus. Leptin receptors have also been identified in the vagus nerve. Studies in the rodents clearly indicate that leptin and CCK interact synergistically to induce short-term inhibition of food intake and long-term reduction of body weight. The synergistic interaction between vagal CCK-A receptor and leptin is mediated by the phosphorylation of signal transducer and activator of transcription3 (STAT3), which in turn, activates closure of K+ channels, leading to membrane depolarization and neuronal firing. This involves the interaction between CCK/SRC/phosphoinositide 3-kinase cascades and leptin/Janus kinase-2/phosphoinositide 3-kinase/STAT3 signaling pathways. It is conceivable that malfunctioning of these signaling molecules may result in eating disorders.
Appetite ; Body Weight ; Cholecystokinin ; Eating ; Feeding and Eating Disorders ; Feeding Behavior ; Fires ; Hypothalamus ; Leptin ; Membranes ; Neurons ; Nodose Ganglion ; Phosphorylation ; Receptor, Cholecystokinin A ; Receptors, Leptin ; Rodentia ; Signal Transduction ; Solitary Nucleus ; Transducers ; Vagus Nerve

INTRODUCTION: Cholecystokinin (CCK) belongs to a group of endogenous molecules known as brain-gut neuropeptides and functions as a neuropeptide as well as a gut hormone. It remains unclear whether genetic variation of the CCK receptor plays a role in irritable bowel syndrome (IBS). The aim of this study was to determine and compare the allele and genotype frequencies of the CCK1 receptor polymorphisms between healthy controls and patients with IBS. METHODS: Genotyping of 80 patients with IBS (who met the Rome III criteria) and 76 healthy controls was performed. We performed PCR amplification for the CCK1 receptor intron 1 779 T > C and Exon 1 G > A. We confirmed polymorphisms by direct sequencing method. RESULTS: There was a significantly different trend for genotypic distributions of the CCK1 receptor polymorphism between patients with IBS and healthy controls (p for trend = 0.048). The CCK1 receptor intron 1 779 T >C polymorphic type was more common in patients with 'IBS-constipation predominant (IBS-C) and IBS-mixed (IBS-M) forms' (19/31, 61.3%) than healthy controls 32/76, 42.1% adjusted odd ratio 2.43, 95% Confidence interval 1.01-5.86). The genotypic distributions of the CCK1 receptor exon 1 polymorphism were not significantly different between the two groups (p for trend = 0.223). CONCLUSIONS: CCK1 receptor polymorphisms were associated with IBS. In particular, the CCK1 receptor intron 1 779 T > C polymorphic type was associated with 'IBS-C and IBS-M'. Further studies are needed in larger number of patients with an even distribution of IBS subtypes.
Alleles ; Cholecystokinin ; Exons ; Genetic Variation ; Genotype ; Humans ; Introns ; Irritable Bowel Syndrome ; Neuropeptides ; Polymerase Chain Reaction ; Receptors, Cholecystokinin ; Rome

<b>OBJECTIVEb>To explore the effect and mechanism of Poly I:C in inducing growth inhibition and apoptosis of human hepatocellular carcinoma SMMC-7721 cells.

<b>METHODSb>SMMC-7721 cells were treated with different doses of Poly I:C for 24, 48, and 72 h, and the cell growth inhibition rate was analyzed with CCK-8 assay. The cell cycle and the apoptosis were analyzed using flow cytometry with Annexin-V and PI staining, and quantitative RT-PCR analysis were used to detect the expression of TLR3, TRIF, and IFN-beta mRNA in cells.

<b>RESULTSb>In the cells exposed to Poly I:C at low, moderate, and high doses, the inhibitory rates was the highest in high-dose Poly I:C group, and at a given Poly I:C dose, prolonged exposure resulted in significantly increased cell growth inhibition rate (P<0.05). Flow cytometry showed that Poly I:C induced cell apoptosis in a time- and dose-dependent manner and significantly increased the percentage of G1-phase cells as compared with that in the control group. The mRNA level of TLR3, TRIF, and IFN-beta were also increased following Poly I:C treatment in comparison with the control group.

<b>CONCLUSIONb>Poly I:C can induce significant growth inhibition and apoptosis of SMMC-7721 cells in a dose- and time-dependent manner possibly by causing cell cycle arrest and TLR3 signaling pathway activation that leads to IFN-beta production and cell apoptosis.

Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Interferon-beta ; genetics ; metabolism ; Liver Neoplasms ; pathology ; Poly I-C ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Receptors, Cholecystokinin ; metabolism ; Signal Transduction ; Toll-Like Receptor 3 ; genetics ; metabolism

<b>AIMb>CCK is one of the strongest endogenous anti-opioid substances and suppresses morphine tolerance which results from long term use of morphine. This study explores the modulatory effect of CCK on pain formalin-induced.

<b>METHODSb>The effect of formalin-induced pain on CCK immunoreactivity in rat sensory neurons was observed through immunohistochemistry technique.

<b>RESULTSb>After 1 h of subcutaneous injection of formalin in one paw of rats, the number of positive neurons of CCK immunoreactivity in spinal cord neurons was obviously increased and greater than that of non-injection side (P <0.01). The semi-quantitative optical density average values of CCK immunoreactivity neurons were 0.397 +/- 0.014 and 0.295 +/- 0.007 in injection side and non-injection side respectively, the difference was obvious (P < 0.01). After 3 h of subcutaneous injection of formalin in one paw of rats, the semi-quantitative optical density average values of CCK immunoreactivity neurons were 0.366 +/- 0.009 and 0.303 +/- 0.005 in injection side and noninjection side respectively, the difference was significant (P < 0.01).

<b>CONCLUSIONb>Formalin-induced pain can significantly change semi-quantitative optical density average value of CCK immunoractivity in spinal cord neurons, this indicates CCK participates in modulation of pain.

Animals ; Cholecystokinin ; metabolism ; physiology ; Female ; Formaldehyde ; Male ; Neurons ; metabolism ; Pain ; chemically induced ; physiopathology ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Cholecystokinin ; metabolism ; physiology ; Spinal Cord ; metabolism ; pathology