Pseudo-allergic reactions (PARs) widely occur upon application of drugs or functional foods. Anti-pseudo-allergic ingredients from natural products have attracted much attention. This study aimed to investigate anti-pseudo-allergic compounds in licorice. The anti-pseudo-allergic effect of licorice extract was evaluated in rat basophilic leukemia 2H3 (RBL-2H3) cells. Anti-pseudo-allergic compounds were screened by using RBL-2H3 cell extraction and the effects of target components were verified further in RBL-2H3 cells, mouse peritoneal mast cells (MPMCs) and mice. Molecular docking and human MRGPRX2-expressing HEK293T cells (MRGPRX2-HEK293T cells) extraction were performed to determine the potential ligands of MAS-related G protein-coupled receptor-X2 (MRGPRX2), a pivotal target for PARs. Glycyrrhizic acid (GA) and licorice chalcone A (LA) were screened and shown to inhibit Compound48/80-induced degranulation and calcium influx in RBL-2H3 cells. GA and LA also inhibited degranulation in MPMCs and increase of histamine and TNF-α in mice. LA could bind to MRGPRX2, as determined by molecular docking and MRGPRX2-HEK293T cell extraction. Our study provides a strong rationale for using GA and LA as novel treatment options for PARs. LA is a potential ligand of MRGPRX2.
Animals ; Anti-Allergic Agents/therapeutic use* ; Calcium/metabolism* ; Cell Degranulation ; Glycyrrhiza ; HEK293 Cells ; Humans ; Hypersensitivity/drug therapy* ; Mast Cells/metabolism* ; Mice ; Mice, Inbred C57BL ; Molecular Docking Simulation ; Nerve Tissue Proteins/metabolism* ; Rats ; Receptors, G-Protein-Coupled/metabolism* ; Receptors, Neuropeptide/therapeutic use*

PURPOSE: High-fat (HF) feeding induces hypothalamic leptin resistance via the activation of toll-like receptor 4 (TLR4). TLR4 deficiency confers resistance to diet-induced obesity. Udenafil, an anti-impotence drug, inhibits TLR4 in airway epithelial cells in vitro. In this study, we evaluated whether udenafil suppressed the hypothalamic expression of TLR4 and reduced body weight. MATERIALS AND METHODS: The hypothalamic expression of TLR4, phosphodiesterase 5 (PDE5), nuclear factor-κB (NF-κB), and myeloid differentiation primary response gene 88 (Myd88) was analyzed by real-time polymerase chain reaction after treating mice for 2 days with udenafil (0, 12, 120, or 600 µg/d). Furthermore, the hypothalamic expression of TLR4, pro-opiomelanocortin (POMC), and neuropeptide Y (NPY) was analyzed after 9 days' treatment with udenafil and/or leptin. We also measured body weight and food intake following 9 days of udenafil and/or leptin treatment in control- and HF-fed mice. RESULTS: Udenafil suppressed hypothalamic TLR4 mRNA expression dose-dependently. The changes were associated with decreased PDE5, NF-κB, and Myd88 expression. Udenafil treatment for 9 days reduced body weight and caloric intake in HF-fed mice. This may have been associated with the suppression of NPY expression that was elevated by HF feeding. POMC expression was not affected by udenafil. However, udenafil did not augment the effects of leptin on the reduction of body weight and caloric intake in HF-fed mice. CONCLUSIONS: These results suggested that udenafil reduced body weight by suppressing hypothalamic TLR4 mRNA expression in HF-fed mice and the combination effect of udenafil and leptin was additive rather than synergistic.
Animals ; Body Weight ; Cyclic Nucleotide Phosphodiesterases, Type 5 ; Eating ; Energy Intake ; Epithelial Cells ; Hypothalamus ; In Vitro Techniques ; Leptin ; Mice ; Neuropeptide Y ; Obesity ; Pro-Opiomelanocortin ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Toll-Like Receptor 4 ; Toll-Like Receptors

To study the expression and distribution of neuropeptide Y (NPY) and long leptin receptor (OB-Rb) in the gastrointestinal tract of giant panda, samples of three animals were collected from the key laboratory for reproduction and conservation genetics of endangered wildlife of Sichuan province, China conservation and research center for the giant panda. Paraffin sections of giant panda gastrointestinal tissue samples were observed using hematoxylin-eosin staining (HE) and strept actividin-biotin complex immunohistochemical staining (IHC). The results show that the intestinal histology of three pandas was normal and no pathological changes, and there were rich single-cell and multi-cell mucous glands, long intestinal villi and thick muscularis mucosa and muscle layer. Positive cells expressing NPY and OB-Rb were widely detected in the gastrointestinal tract by IHC methods. NPY positive nerve fibers and neuronal cell were widely distributed in submucosal plexus and myenteric plexus, especially in the former. They were arranged beaded or point-like shape. NPY positive cells were observed in the shape of ellipse and polygon and mainly located in the mucous layer and intestinal glands. OB-Rb positive cells were mainly distributed in the mucous layer and the laminae propria, especially the latter. These results confirmed that NPY and OB-Rb are widely distributed in the gut of the giant panda, which provide strong reference for the research between growth and development, digestion and absorption, and immune function.
Animals ; China ; Intestines ; metabolism ; Neuropeptide Y ; genetics ; metabolism ; Receptors, Leptin ; genetics ; metabolism ; Ursidae ; genetics ; metabolism

Animal studies indicate that gonadal steroids have prominent neuroprotective effects in several models of experimental traumatic brain injury (TBI). Neuromedin U (NMU) and neuromedin S (NMS) are regulatory peptides involved in inflammatory and stress responses, and modulation of the gonadotropic axis. Since steroid hormone levels change during the estrous cycle, we sought to determine whether variations in ovarian hormones would affect blood-brain barrier (BBB) permeability and brain levels of NMS, NMU, and neuromedin S receptor 2 in experimental TBI. Two groups (proestrus and nonproestrus) of female rats underwent diffuse TBI. At 24 hrs after TBI, results showed a significantly decrease in BBB permeability in traumatic-proestrus animals (TBI-P) in comparison to traumatic nonproestrus (TBI-NP) rats. Western blot analyzes demonstrated an enhanced expression of prepro-NMS in TBI-P compared with that in the TBI-NP group. Likewise, TBI-P rats exhibited significantly higher NMUR2 gene expression compared with those of TBI-NP, whereas no significant difference in brain NMU content was seen between sham and traumatic animals. Our findings indicate that diffuse TBI induces an increase in prepro-NMS and neuromedin S receptor 2 expression in traumatic-proestrus rats which may mediate the anti-edematous effects of gonadal hormones in proestrus rats following trauma.
Neuropeptides ; Receptors, Neuropeptide

Neuropeptide Y (NPY), a sympathetic neurotransmitter, is highly associated with baroreflex dysfunction and multiple cardiac diseases such as diabetic myocardiopathy. In the present study, we aimed to explore the role of peripheral NPY Y1 receptor (Y1R) and Y2 receptor (Y2R), which are dominantly present in peripheral cardiovascular control, in baroreflex sensitivity (BRS) of streptozotocin (STZ)-induced diabetic rats. Peripheral Y1R and Y2R were antagonized by specific antagonists (BIBP 3226 and BIIE 0246, respectively) from subcutaneously implanted ALZET mini-osmotic pump in STZ-induced diabetic rats for 4 weeks. Then baseline systolic blood pressure, heart rate, cardiac function, BRS, plasma NPY and lipid levels were evaluated. We found that STZ led to increased plasma NPY and lipid level. And the STZ-increased lipid levels were reduced by BIBP 3226 and BIIE 0246. BIBP 3226 ameliorated the aberrant BRS, but had little effect on the impaired cardiac function of the STZ rats. BIIE 0246 alleviated sodium nitroprusside (SNP)-induced but not phenylephrine (PE)-induced aberrant baroreflex control of heart rate in the STZ rats. In addition, BIIE 0246 alleviated the bradycardia, but further impaired cardiac contractility in the STZ rats. These results suggest that peripheral Y1R and Y2R play different roles in STZ-induced impairment of BRS.
Animals ; Arginine ; analogs & derivatives ; pharmacology ; Baroreflex ; Benzazepines ; pharmacology ; Blood Pressure ; Bradycardia ; Diabetes Mellitus, Experimental ; drug therapy ; physiopathology ; Heart Rate ; Myocardial Contraction ; Neuropeptide Y ; blood ; Rats ; Receptors, Neuropeptide Y ; antagonists & inhibitors ; Streptozocin

OBJECTIVE: Lin28 has been known to control the proliferation and pluripotency of embryonic stem cells. The purpose of this study was to determine the downstream effectors of Lin28 in mouse embryonic stem cells (mESCs) by RNA interference and microarray analysis. METHODS: The control siRNA and Lin28 siRNA (Dharmacon) were transfected into mESCs. Total RNA was prepared from each type of transfected mESC and subjected to reverse transcription-polymerase chain reaction (RT-PCR) analysis to confirm the downregulation of Lin28. The RNAs were labeled and hybridized with an Affymetrix Gene-Chip Mouse Genome 430 2.0 array. The data analysis was accomplished by GenPlex 3.0 software. The expression levels of selected genes were confirmed by quantitative real-time RT-PCR. RESULTS: According to the statistical analysis of the cDNA microarray, a total of 500 genes were altered in Lin28-downregulated mESCs (up-regulated, 384; down-regulated, 116). After differentially expressed gene filtering, 31 genes were selected as candidate genes regulated by Lin28 downregulation. Among them, neuropeptide Y5 receptor and oocyte-specific homeobox 5 genes were significantly upregulated in Lin28-downregulated mESCs. We also showed that the families of neuropeptide Y receptor (Npyr) and oocyte-specific homeobox (Obox) genes were upregulated by downregulation of Lin28. CONCLUSION: Based on the results of this study, we suggest that Lin28 controls the characteristics of mESCs through the regulation of effectors such as the Npyr and Obox families.
Animals ; Chimera ; Down-Regulation ; Embryonic Stem Cells ; Genes, Homeobox ; Genome ; Humans ; Mice ; Neuropeptide Y ; Neuropeptides ; Oligonucleotide Array Sequence Analysis ; Receptors, Neuropeptide Y ; RNA ; RNA Interference ; RNA, Small Interfering ; Statistics as Topic

The present study was to investigate the effects of diltiazem, a ghrelin receptor agonist, on food intake and gastrointestinal functions in rats. Rats were intragastrically administered with diltiazem solution (daily 16 mg/kg, 30 mg/kg or 80 mg/kg, 30 d), and the rats with saline as control. To detect the effects of diltiazem on food intake and body weight, the average daily food intake and body weight were recorded, and the serum metabolic hormones of plasma growth hormone (GH) and neuropeptide Y (NPY) were tested by radioimmunoassay. By means of the spectrophotometer and the modified Mett's method, the effects of diltiazem on rat's gastrointestinal function and pepsin activity were tested, respectively. In addition, the gastric juice's acidity of rats was detected by titration and the secretion amount was calculated. The results showed that the food intake and body weight were maximally promoted by diltiazem at the dose of 30 mg/kg daily (30 d). The average daily food intake and body weight were significantly increased, and the serum concentrations of GH and NPY were also remarkably increased in diltiazem-treated groups compared with those in control group. The results also showed that the gastric emptying rate, gastric acid secretion and the activity of pepsin were significantly increased in diltiazem-treated group compared with those in control group. These results suggest that diltiazem induces enhancement of eating, in the same time, it can also stimulate the gastrointestinal function and regulate growth of rat.
Animals ; Body Weight ; drug effects ; Diltiazem ; pharmacology ; Eating ; drug effects ; Female ; Gastric Emptying ; drug effects ; Gastrointestinal Motility ; drug effects ; Gastrointestinal Tract ; physiology ; Growth Hormone ; blood ; Neuropeptide Y ; blood ; Rats ; Rats, Sprague-Dawley ; Receptors, Ghrelin ; agonists

OBJECTIVETo look for the evidences of motilin receptor expression on interstitial cells of Cajal (ICC) of the rabbit.

METHODSmooth muscle segments with ICC were isolated from the small intestine of 10-day old rabbits. The tissue segments equilibrated in Ca(2+)-free Hanks' solution were dispersed with an enzyme solution containing collagenase type II and then Ficoll density centrifugation was used to dissociate ICC. The cells were suspended and cultured in the M199 medium. The c-kit antibody was applied to distinguish the cultured ICC. The motilin receptor was identified by immunocytochemical assay with GPR38 antibody, c-kit antibody and hoechst 33342 combined to label ICC. Cells cultured for a few days were sorted for ICC with c-kit stained green fluorescent through flow cytometry. The total RNA and proteins extracted from the sorted ICC were respectively used to verify motilin receptor on the ICC by reverse-transcriptase polymerase chain reaction (RT-PCR) and Western blotting.

RESULTWe had successfully dissociated and cultured ICC of rabbit small intestine in vitro. Fluorescent staining with c-kit antibody confirmed that the culture ICC was successful. Triple-labeled immunofluorescent staining had detected the motilin receptor on membrane of ICC. Flow cytometry analysis showed that the ratio of c-kit positive cell in the cultured cells was 64.3%. The number of sorted ICC was 6.7 × 10(5) and 5.6 × 10(6). The results of RT-PCR and Western blot confirmed that the ICC had motilin receptor expression.

CONCLUSIONOur study demonstrated presence of motilin receptor on ICC of the rabbit. The present results may suggest that ICC play an important role in gastrointestinal movement induced by motilin.

Animals ; Cells, Cultured ; Interstitial Cells of Cajal ; metabolism ; Intestine, Small ; cytology ; Rabbits ; Receptors, Gastrointestinal Hormone ; metabolism ; Receptors, Neuropeptide ; metabolism

The regulation of growth hormone (GH) secretion is, to a larger extent, controlled by three hypothalamic hormones: GH-releasing hormone (GHRH), somatostatin, and ghrelin. Each binds to G protein-linked membrane receptors through which signaling occurs. We used a series of genetic and transgenic animal models with perturbations of individual compounds of the GH regulatory system to study somatotrope signaling. Impaired GH signaling is present in the lit mouse, which has a GHRH receptor (GHRH-R) mutation, and the dw rat, which has a post-receptor signaling defect. Both models also have impaired response to GH secretagogues (GHS), implying an interaction between the two signaling systems. The spontaneous dwarf rat (SDR), in which a mutation of the GH gene results in total absence of the hormone, shows characteristic changes in the hypothalamic regulatory hormones due to an absence of GH feedback and alterations in the expression of each of their pituitary receptors. Treatment of SDRs with GHRH and a GHS has allowed demonstration of a stimulatory effect GHRH on GHRH-R and GHS-R, and somatostatin receptor type 2 (sst2) expression and an inhibitory effect on sst5 expression. GH also modifies the expression of these receptors, though its effects are seen at later time periods and appear to be indirect. In the absence of GH negative feedback, both hypothalamic and pituitary expression is altered to favor stimulation of GH synthesis and release. However, in the presence of GH negative feedback, both hypothalamic and pituitary expression is altered to favor suppression of GH synthesis and release. Loss of liver insulin-like growth factor I (IGF-I) feedback on the hypothalamic-pituitary system increases GH secretion, which, in turn, stimulates liver growth. Depletion of liver-derived IGF-I increases the expression and sensitivity of pituitary GHRH-R and GHS-R. The major site of action of liver-derived IGF-I in the regulation of GH secretion is at the pituitary level. Neuropeptide Y (NPY) is not required for basal regulation of the GH axis. NPY is required for fasting-induced suppression of GHRH and SRIH expression. NPY is also required for fasting-induced augmentation of pituitary GHS-R mRNA. Overall, the results indicate a complex regulation of GH secretion in which somatotrope receptor, as well as ligand expression, exerts an important physiological role.
Animals ; Animals, Genetically Modified ; Axis ; Ghrelin ; Growth Hormone ; Hypothalamus ; Insulin-Like Growth Factor I ; Liver ; Membranes ; Mice ; Neuropeptide Y ; Rats ; Receptors, Neuropeptide ; Receptors, Pituitary Hormone-Regulating Hormone ; Receptors, Somatostatin ; RNA, Messenger ; Somatostatin

Accumulating evidence indicates an important role of hippocampal dendrite atrophy in the development of depression, while neuropeptide Y (NPY) participates in hippocampal dendrite growth. The present study was aimed to investigate the relationship between NPY and nitric oxide synthase (NOS) in chronic unpredictable mild stress (CUMS)-induced depression. CUMS-induced depression model was established in Sprague-Dawley rats. Intrahippocampal microinjections of NPY, NPY-Y1 receptor antagonist GR231118 and non-specific NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME) were respectively adopted by rat brain stereotaxic coordinates. The behavioral observations were conducted by sucrose consumption test, open field test and forced swimming test. The expressions of NPY, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in hippocampus were detected by immunohistochemistry. The results showed that, compared with the control group, rats receiving CUMS for 21 d or intrahippocampal microinjection of GR231118 showed a significant reduction in body weight and depression-like behavior, which included reductions in sucrose preference, locomotor activity, rearing and grooming in open field test, and increased duration of immobility in forced swimming test. Moreover, the expression of NPY significantly decreased (P<0.01), while the expressions of nNOS and iNOS increased obviously in the hippocampal dentate gyrus (DG) and CA3 regions (P<0.01). Intrahippocampal microinjections of NPY prevented the depression-like behavioral changes induced by CUMS and decreased the expressions of nNOS and iNOS in the hippocampal DG and CA3 regions (P<0.01). Intrahippocampal microinjections of GR231118 reduced behavioral ability of the rats dramatically and significantly increased the expressions of hippocampal nNOS and iNOS (P<0.01). Intrahippocampal microinjections of L-NAME suppressed the depression-like behavioral changes induced by CUMS or intrahippocampal microinjection of GR231118. In conclusion, reduced expression of NPY and increased expression of NOS in hippocampus may make significant contributions to CUMS-induced depression. These results suggest that the antidepressant function of NPY associates with down-regulation of NOS expression in hippocampus, possibly mediated via NPY-Y1 receptor.
Animals ; Antidepressive Agents ; pharmacology ; Behavior, Animal ; drug effects ; Depression ; Down-Regulation ; Hippocampus ; drug effects ; Microinjections ; NG-Nitroarginine Methyl Ester ; pharmacology ; Neuropeptide Y ; pharmacology ; Nitric Oxide Synthase Type I ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Peptides, Cyclic ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Neuropeptide Y ; antagonists & inhibitors