Neuropéptidos, estrés y alergia / Neuropeptides, stress and allergy

Histophysiological and biochemical data are exposed supporting the close connection between the central nervous system (cortex limbic system hypothalamus hypophysis) and the endocrine one. Evidences that some neural peptides (opioid neuropeptides: ONP) have specific receptors in immune cells and on the other hand that these cells produce cytokines that influence the neurons are described. It seems reasonable that under acute or chronic stress situations both systems strongly interconnected to maintain the homeostasis. The acute stress influences the innate immune response meanwhile the chronic one seems to affect the adaptative or acquired mechanism specially at the cytotoxic level. Allergic patients are deeply worsened by acute and chronic stress considering that the mastocytes are the tarjet of numerous cytokines and ONP released during the unpleasant events. So, we recommend peace in the mind, faith in the heart and work in the hands.

Effect of vasoactive intestinal peptide receptor antagonist VIPhybrid on the development of form deprivation myopia in chicks / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of regulation of VIPhybrid, an unselective antagonist of vasoactive intestinal peptide receptors (VIPR), on the formation and development of form deprivation myopia (FDM) in chick and the expression of protein and mRNA of VIP on the retina and choroids of in chicks.@*METHODS@#Seventy-two 1-day-old yellow healthy leghorn chicks were assigned into 6 groups (12 in each group). Eyes in Group I were covered on the right as a blank control group. Eyes in GroupII were those eyes having been injected with 20 microL saline into vitreous cavity and then covered as a negative control group. Eyes in GroupIII,IV and V were injected with 20 microL VIPhybrid with low (3*10(-12) mol/L), middle (3*10(-10) mol/L) and high (3*10(-8) mol/L) dosage into vitreous cavity and then covered as experimental groups. The above groups had been continuously covered for 1 week. Eyes in Group VI were uncovered and uninjected as a normal control group. Diopter was detected using retinoscopic refraction. The eyeball axis was determined using ophthalmological ultra-A. The expression of protein and mRNA of VIP on retina-choroids-sclera were investigated by SP immunohistochemistry staining and RT-PCR.@*RESULTS@#Form deprivation for 1 week induced high myopia eyes and elongated eyeball axis in GroupI and GroupII, and there was no difference between the 2 groups (P>0.05). The diopter and eyeball axis were significantly reduced in Group III, IV, and V as compared with Group I and II (P<0.01), but the diopter was higher and the eyeball axis was longer than those of Group VI. The diopter and eyeball axis had negative correlation with the concentration gradient of VIPhybrid. The expressions of protein and mRNA of VIP in Group III, IV, and V were down-regulated as compared with those of Group I and I I(P<0.01)and also down-regulated with the increase of concentration of VIPhybrid.@*CONCLUSION@#VIPhybrid can decrease the development of FDM in chicks, which may provide a new pathway for drug therapy of myopia in human beings.

Analysis of Gene Expression Profile of AGS Cells Stimulated by Helicobacter pylori Adhesion

BACKGROUND/AIMS: Interactions between H. pylori and gastric epithelial cells contribute to gastric inflammation and epithelial damage. This study was performed to evaluate the gene expression profile of AGS cells by adhesion of H. pylori. METHODS: Changes in AGS cell gene expression induced by co-culturing with H. pylori (G69a strain) (4, 12, 24, 48 hours) were monitored using oligonucleotide microarray. Real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed for data validation by the Assay-on-Demand Gene Expression product method. RESULTS: A total of 270 (2.66%) and 19 genes (0.19%) were up-regulated in AGS cells by H. pylori adhesion. Gene ontology analysis showed that up-regulated genes were categorized into endolipidase activity (17 genes), receptor binding (17 genes), integrin binding (4 genes), and two down-regulated genes into GTP binding category. The expression levels of 20 up- and 5 down-regulated genes were quantified by real-time RT-PCR. Sixteen genes involving cytokine activity (IL8, IL1B, TNF), hydrolase activity (PTP4A1, ERCC1, CASP8, CASP7, ACIN1), VIP receptor activity (VIPR2), and neuropeptide Y receptor activity (GPR83) were confirmed to be up-regulated. Five genes, namely, ARF3, M17S2, DDB2, AWP1, and WTAP were confirmed to be down-regulated. CONCLUSIONS: Host genes are significantly changed by H. pylori adhesion, which might explain the gastroduodenal pathogenesis induced by H. pylori infection.

Quantitative variation of vasoactive intestinal polypeptide and its receptor in rat liver during development / 生理学报

Accumulated data have suggested that vasoactive intestinal polypeptide (VIP) and corresponding receptor (VIPR) are involved in the development of hematopoietic stem cells and liver growth. In the present study, radioimmunoassay, biomolecular interaction analysis and reverse transcriptation polymerase chain reaction were used to quantify VIP, VIPR and detect the subtype of VIPR in rat liver during development. VIP concentration of liver in fetal or neonatal rats was significantly lower than that of teens or adult rats (P<0.05). The binding capacities of VIPR in liver of immature rats were much greater than that of the adult rats (P<0.05). The tendency of change in VIP concentration was contrary to that of the binding capacity of VIPR in the liver of rats during development. VIPR-1 was expressed in rat liver in all phases of development. These results may be of benefit to the understanding of the mechanisms of liver growth and fetal liver hemopoiesis shift.

Temporal and spatial distribution of VIP, CGRP and their receptors in the development of airway hyperresponsiveness in the lungs / 生理学报

To explore the role of intrapulmonary neuropeptides in the development of airway hyperresponsiveness, we established an animal model of airway hyperresponsiveness (AHR) in rabbits by using ozone exposure. With the model, after test of the mechanics of respiration and bronchoalveolar lavage assay, the levels of vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) in the lungs were determined by radioimmunoassay, and the expression of mRNA coding receptors of these two neuropeptides was evaluated by reverse transcriptional-polymerase chain reaction (RT-PCR). At the same time, the distribution of VIP receptor-1 (VIPR1) and CGRP receptor-1 (CGRPR1) in lung tissues and its time-course were examined by in situ hybridization. The results showed: (1) in ozone-stressing groups, airway resistance increased significantly and typical inflammatory pathological changes were observed in pulmonary tissue slides, including neutrophil and eosinophil infiltration, mucus exudation and bronchial epithelial cells (BECs) shedding; (2) with elongation of ozone exposure, the levels of VIP and CGRP in the lungs increased at first, reaching a peak on d 2 to 4, then decreased slowly, and CGRP peaked somewhat earlier than VIP; (3) mRNA expression of the two neuropeptide receptors in the lungs changed in a similar manner like VIP and CGRP, but the high level of mRNA expression of VIPR1 lasted longer than that of CGRPR1; and (4) in situ hybridization for neuropeptide receptors demonstrated that, in unstressed control, VIPR1 and CGRPR1 positive cells appeared in the airway epithelium, pulmonary interstitial and focal areas of airway and vascular smooth muscles. With the elongation of ozone exposure, hybridization stained deeper and the majority of positive cells were located around the vessels and bronchus except a few in the alveoli. At 8 d, only a small number of positive cells were seen in the lungs. From the results, it is concluded that ozone-stressing can induce the development of AHR, in which VIP and CGRP may play important roles. That implies, through binding to CGRPR1, CGRP stimulates an early inflammation response which contributes in cleaning up of irritants, while VIP exerts a later dampening of pulmonary inflammation response. These two neuropeptides may play sequential and complementary roles in the development of AHR.

The Effect of Vasoactive Intestinal Peptide on Cord Blood CD34 (+) Cells / 대한소아혈액종양학회지

PURPOSE: We investigated the expression of vasoactive intestinal peptide (VIP), VIP receptor 1 (VPAC1), VIP receptor 2 (VPAC2) genes in the human umbilical cord blood CD34 cells, and the ability of VIP to stimulate human primitive as well as monopotent hematopoietic progenitors. METHODS: We isolated RNA from umbilical cord blood CD34 cells, and then performed RT-PCR, and sequencing. The umbilical cord blood CD34 cells were cultured with the various concentrations of VIP for burst-forming unit of erythrocyte (BFU-E), colony-forming unit of granulocyte/monocyte (CFU-GM), colony-forming unit of graulocyte/erythrocyte/monocyte/megakaryocyte (CFU-GEMM), and colony-forming unit of megakaryocyte (CFU-Mk). RESULTS: The RNA coding for VPAC1 was detected in human umbilical cord blood CD34 cells. VIP significantly stimulated the growth of CFU-GEMM and CFU-Mk. CONCLUSION: The present results suggest that VIP is an important neuropeptide in the early proliferation of human primitive as well as megakaryocyte progenitors.

Effects of vasoactive intestinal peptide on chemotaxis of bronchial epithelial cells / 生理学报

To investigate the influence of vasoactive intestinal peptide (VIP) on chemotaxis of bronchial epithelial cells (BECs). Rabbit chemotactic migration of primary BEC was assessed in a blind-well Boyden chamber. Radioimmunoassay and radio-ligand affinity analysis were used for determining VIP secretion and vasoactive intestinal peptide receptor (VIPR) expression. The results showed: (1) the method for determining chemotaxis of BECs by using insulin as chemotactic factor was stable and reproducible (r=0.9703, P<0.01). (2) VIP (0.001-1 micromol/L) elicited chemotaxis of BECs which was substantial and concentration-dependent. The effects of VIP were inhibited by W-7 and H-7 (P<0.01). (3) Heat stress enhanced the secretion of VIP (P<0.01) and upregulated the expression of VIPR on BECs (P<0.05). These results indicate that VIP in the lungs may play an important role in the repair of damaged epithelium, accelerating restoration of the airway to its normal state. Calmodulin and protein kinase C may be involved in the signal transduction of VIP effects.

Pre-clinical study on tumor vasoactive intestinal peptide receptor scintigraphy / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To develop a tumor imaging agent for vasoactive intestinal peptide (VPAC) receptor and evaluate its biological activity and pharmacokinetics of radiolabeled peptide.</p><p><b>METHODS</b>VIP(28) was modified at the carboxyl terminal by the addition of His-tag which was the chelating site of (99m)Tc(I) and the general purification tag for immobilized metal ion affinity chromatography. Biological activity of the modified VIP(28) analogue MY34 was examined in vitro by radiological cell-binding assay, rabbit internal anal sphincter (IAS) smooth muscle relaxing assay and immunocytochemical stain. The pharmacokinetics of this labeled peptide was examined in C57 mice.</p><p><b>RESULTS</b>MY34 could relax the IAS smooth muscle and bind VPAC receptors on tumor cell membranes. (99m)Tc- MY34, with a yield of about 90%, was stable enough for practical use. Both MY34 and VIP(28) could inhibit the binding between the labeled peptide and VPAC receptor. The pharmacokinetics of [(99m)Tc(H(2)O)(3)(CO)(3)]-MY34 was studied in mice conformed well with the two-compartment model (Wi = 1/C(2)), with a t(1)/(2alpha) of 16.35 min and a t(1)/(2beta) of 1013.56 min.</p><p><b>CONCLUSION</b>MY34 possesses physiological activities and specific receptor binding characteristics similar to those of natural VIP(28).</p>

Novel vip analogues: relative potency, duration of action and antagonism to relaxant effect of natural vip on guinea pig trachea

This study was performed on two novel VIP analogues; namely, [N1e17, A1a24, A1a25, Va126]-VIP-[1-27]-NH2 [analogue 1] and [Ser [SO3H]3, Nle17-VIP [analogue 2], which were obtained by undergoing certain changes in the amino acid sequence of the VIP molecule in a trial to reach a novel more stable, but still active form of VIP. Relative potency as well as duration of action of the two analogues was tested versus that of native VIP on isolated guinea pig tracheal strips placed in organ baths. Changes in smooth muscle tension were measured by isometric force transducers and recorded continuously. Analogue 1 was significantly more potent and had a significantly longer duration of action than natural VIP as a tracheal relaxant at the lower concentration range of 5 x 10-9 M to 5 x 10-8 M and its maximal relaxing effect was 72% of that of native VIP. Analogue 2 was significantly much less potent than natural VIP at all concentrations tested with maximal potency of only 11% of that of native VIP and showed shorter duration of action. However, it significantly reduced VIP-induced tracheal relaxation. The encouraging results with analogue 1 suggest its clinical trial in therapy of bronchial asthma. As VIP antagonists may potently inhibit the basal growth of cancer cells in vitro and certain tumors in vivo, especially lung carcinoma, analogue 2 may serve as a useful candidate in this respect. The interesting findings with the two analogues suggest further investigation to enhance their potency, whether agonistic [for analogue 1] or antagonistic [for analogue 2], at VIP receptors by additional changes in their molecules to improve the chance of possible clinical applications

The mechanism of gentisic acid-induced relaxation of the guinea pig isolated trachea: the role of potassium channels and vasoactive intestinal peptide receptors

We examined some of the mechanisms by which the aspirin metabolite and the naturally occurring metabolite gentisic acid induced relaxation of the guinea pig trachea in vitro. In preparations with or without epithelium and contracted by histamine, gentisic acid caused concentration-dependent and reproducible relaxation, with mean EC50 values of 18 æM and Emax of 100 percent (N = 10) or 20 æM and Emax of 92 percent (N = 10), respectively. The relaxation caused by gentisic acid was of slow onset in comparison to that caused by norepinephrine, theophylline or vasoactive intestinal peptide (VIP). The relative rank order of potency was: salbutamol 7.9 > VIP 7.0 > gentisic acid 4.7 > theophylline 3.7. Gentisic acid-induced relaxation was markedly reduced (24 + or - 7.0, 43 + or - 3.9 and 78 + or - 5.6 percent) in preparations with elevated potassium concentration in the medium (20, 40 or 80 mM, respectively). Tetraethylammonium (100 æM), a nonselective blocker of the potassium channels, partially inhibited the relaxation response to gentisic acid, while 4-AP (10 æM), a blocker of the voltage potassium channel, inhibited gentisic acid-induced relaxation by 41 + or - 12 percent. Glibenclamide (1 or 3 æM), at a concentration which markedly inhibited the relaxation induced by the opener of ATP-sensitive K+ channels, levcromakalim, had no effect on the relaxation induced by gentisic acid. Charybdotoxin (0.1 or 0.3 æM), a selective blocker of the large-conductance Ca2+-activated K+ channels, caused rightward shifts (6- and 7-fold) of the gentisic acid concentration-relaxation curve. L-N G-nitroarginine (100 æM), a NO synthase inhibitor, had no effect on the relaxant effect of gentisic acid, and caused a slight displacement to the right in the relaxant effect of the gentisic acid curve at 300 æM, while methylene blue (10 or 30 æM) or ODQ (1 æM), the inhibitors of soluble guanylate cyclase, all failed to affect gentisic acid-induced relaxation. D-P-Cl-Phe6,Leu17[VIP] (0.1 æM), a VIP receptor antagonist, significantly inhibited (37 + or - 7 percent) relaxation induced by gentisic acid, whereas CGRP (8-37) (0.1 æM), a CGRP antagonist, only slightly enhanced the action of gentisic acid.

Vasoactive Intestinal Peptide/Pituitary Adenylate Cyclase Activating Peptide Receptor Subtypes in Neuroblastoma, Stomach Cancer / 대한소아혈액종양학회지

PURPOSE: We analyzed the expression of vasoactive intestinal peptide (VIP), pituitary adenylate cyclase activating peptide (PACAP), VIP receptor 1 (VIPR1), VIP receptor 2 (VIPR 2) and PACAP receptor (PACAPR) genes in human neuroblastoma, neuroblastoma cell line, human stomach cancer, and human stomach cancer cell lines using RT-PCR and Sourthern hybridization. The results should permit identification of potential clinical applications for VIP and PACAP. METHODS: We isolated RNA from 1 neuroblastoma cell line, 8 stomach cancer cell lines, 13 neuroblastoma, and 10 stomach cancer tumor specimens. And then we performed RT-PCR, Sourthern hybridization, and sequencing. RESULTS: We detected the RNAs coding for VIP, VIPR1, VIPR2, PACAP, and PACAPR in 1, 11, 2, 12, and 13 out of 13 neuroblastoma tumor specimens, respectively. VIP and PACAPR RNA was expressed in SKNSH. VIPR1 RNA was expressed in 4 of 8 the stomach cancer cell lines and 6 of 10 stomach cancer tumor specimens. CONCLUSION: VIP/PACAP RNA and VIP/PACAP receptors RNA were expressed in SKNSH and neuroblastoma tumor specimens. VIPR1 was expressed in stomach cancer cell lines and tumor specimens. The present results suggested that VIP/PACAP analogues could be a candidate as the growth inhibitor of neuroblastoma and stomach cancer.

Effect of Vasoactive Intestinal Peptide on the Necrotic or Apoptotic Neuronal Death in Murine Cortical Cell Cultures

OBJECTIVE: The purpose of this study was to examine the effects of VIP on the apoptotic neuronal death induced by serum deprivation and the necrotic(excitotoxic) neuronal death by the exposure of NMDA in primary murine cortical cell cultures. MATERIALS AND METHODS: Near-pure neuronal cell cultures were prepared by plating fetal mice cortical cells onto polyethyleneimine-coated 24 well vessels. At 7 days in vitro(DIV), serum was removed from culture media for 24 hrs in near-pure neuronal cultures. Mixed cortical cell cultures containing both neurons and glia were prepared by plating fetal mice cortical cells onto an established monolayer of glia. At 12-14 DIV, excitotoxic neuronal death was induced by the addition of NMDA into the mixed cortical cultures. The neuronal cell death was assessed by either MTT or LDH assay after microscopic examination. RESULTS: Near-pure neuronal cell cultures deprived of serum undergo neuronal apoptosis marked by cell body shrinkage, chromatin condensation and DNA ladders. The apoptotic neuronal death following serum deprivation was significantly attenuated by the inclusion of a membrane-permeable cAMP analogue(8-bromo-cAMP; 100nM), an adenyl cyclase stimulator(forskolin; 10nM), a protein synthesis inhibitor(cycloheximide; 0.1ng/ml) or cell membrane depolarization(25mM KCl) during serum deprivation, but was not affected by the addition of an NMDA antagonist (MK-801; 10nM) or an antioxidant(trolox; 100nM). The inclusion of VIP(1, 3, 10nM) during deprivation also significantly prevented the neuronal death without dose-dependency. The neuroprotective effect of VIP(1nM) was not reversed by concomitant treatment with a VIP receptor antagonist([D-p-Cl-Phe6, Leu17]-VIP; 10, 30nM). Neuronglia co-cultures exposed to 300nM NMDA for 5 min produced neuronal death marked by cell body swelling. The neuronal death induced by the exposure of NMDA was markedly attenuated by MK-801 but not affected by 8-bromo-cAMP, forskolin, cycloheximide, high potassium or VIP. CONCLUSION: These results provide an evidence that VIP prevent apoptotic neuronal death induced by serum deprivation and suggest that VIP may have therapeutic potential for diseases in central nervous system linked to apoptotic neuronal death.

Mechanism of vasoactive intestinal polypeptide-induced catecholamine secretion from the rat adrenal medulla

The present study was attempted to investigate the effect of vasoactive intestinal polypeptide (VIP) on secretion of catecholamines (CA) and to establish whether there is the existence of a noncholinergic mechanism in adrenomedullary CA secretion from the isolated perfused rat adrenal gland. The perfusion into an adrenal vein of VIP (3 X 10-6 M) for 5 min or the injection of acetylcholine (ACh, 5.32 X 10-3 M) resulted in great increases in CA secretion. Tachyphylaxis to releasing effect of CA evoked by VIP was not observed by the repeated perfusion. The net increase in adrenal CA secretion evoked by VIP still remained unaffected in the presence of atropine or chlorisondamine. However, the CA release in response to ACh was greatly inhibited by the pretreatment with atropine or chlorisondamine. The releasing effects of CA evoked by either VIP or ACh were depressed by pretreatment with nicardipine, TMB-8, and the perfusion of Ca2+-free medium. Moreover, VIP- as well as ACh-evoked CA secretory responses were markedly inhibited under the presence of (Lys1, Pro2.5, Arg3.4, Tyr6)-VIP or naloxone. CA secretory responses induced by ACh and high K+ (5.6 X 10-2 M) were potentiated by infusion of VIP (3 X 10-6 M for 5 min). Taken together, these experimental results indicate that VIP causes CA release in a fashion of calcium ion-dependence, suggesting strongly that there exists a noncholinergic mechanism that may be involved in the regulation of adrenomedullary CA secretion through VIP receptors in the rat adrenal gland, and that VIP may be the noncholinergic excitatory secretagogue present in the chromaffin cells.