bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms and Modulation of Pituitary Adenylate Cyclase‐Activating Protein‐Induced Calcium Mobilization in Human Neutrophils
Authors: HARFI ISSAM , SARIBAN ERIC
Published: August 2006

Abstract: The neuropeptide pituitary adenylate cyclase‐activating protein (PACAP) acts via the G protein–coupled receptor vasoactive intestinal peptide (VIP)/PACAP receptor‐1 to induce phospholipase C (PLC)/calcium and mitogen‐activated protein kinase(MAPK)‐dependent proinflammatory activities in human polymorphonuclear neutrophils (PMNs). In this article, we evaluate other mechanisms that regulate PACAP‐evoked calcium transients, the nature of the calcium sources, and the role of calcium in proinflammatory activities. Reduction in the activity of PMNs to respond to PACAP was observed after cell exposure to inhibitors of the cAMP/protein kinase A (PKA), protein kinase C (PKC), and PI3K pathways, to pertussis toxin (PTX), genistein, and after chelation of intracellular calcium or after extracellular calcium depletion. Mobilization of intracellular calcium stores was based on the fact that PACAP‐associated calcium transient was decreased after exposure to (a) thapsigargin (Tg), (b) xestospongin C (XeC), and (c) the protonophore carbonyl cyanide 4‐(trifluoromethoxy)phenylhydrazone; inhibition of calcium increase by calcium channel blockers, by nifedipine and verapamil, indicated that PACAP was also acting on calcium influx. Such mobilization was not dependent on a functional actin cytoskeleton. Homologous desensitization with nanomoles of PACAP concentration and heterologous receptors desensibilization by G protein–coupled receptor agonists were observed. Intracellular calcium depletion modulated PACAP‐associated ERK but not p38 phosphorylation; in contrast, extracellular calcium depletion modulated PACAP‐associated p38 but not ERK phosphorylation. In PACAP‐treated PMNs, reactive oxygen species production and CD11b membrane upregulation in contrast to lactoferrin release were dependent on both intra‐ and extracellular calcium, whereas matrix metalloproteinase‐9 release was unaffected by extracellular calcium depletion. These data indicate that both extracellular and intracellular calcium play key roles in PACAP proinflammatory activities.
Protective Role for Plasmid DNA‐Mediated VIP Gene Transfer in Non‐Obese Diabetic Mice
Authors: HERRERA JUAN LUIS , FERNÁNDEZ‐MONTESINOS RAFAEL , GONZÁLEZ‐REY ELENA , DELGADO MARIO , POZO DAVID
Published: August 2006

Abstract:  Studies focused on the development of diabetes in NOD mice—a model for human type 1 diabetes—have revealed that an autoimmune inflammatory process is produced by the effect of Th1 cells and their secreted cytokines. DNA vaccination has been shown to be an effective method for modulating immunity in viral infections and experimental autoimmune diseases, including diabetes. VIP's immunomodulatory properties are partly mediated by skewing the pattern of cytokines from a proinflammatory response to an anti‐inflammatory response. Using gene delivery to express VIP, we interfered in the immune process leading to diabetes in prone, cyclophosphamide‐treated NOD mice. Our results extend the role of VIP in the control of immunoregulatory networks and open new perspectives for immunointervention through VIP‐based gene therapy.
Inhibition of Self‐Renewal and Induction of Neural Differentiation by PACAP in Neural Progenitor Cells
Authors: HIROSE MEGUMI , HASHIMOTO HITOSHI , IGA JUNKO , SHINTANI NORIHITO , NAKANISHI MEGUMI , ARAKAWA NAOHISA , SHIMADA TAKESHI , BABA AKEMICHI
Published: August 2006

Abstract: Several lines of evidence have suggested roles for pituitary adenylate cyclase‐activating polypeptide (PACAP) in the developing nervous system. Previously, we showed that mRNA for PACAP, vasoactive intestinal peptide (VIP), and their three receptor subtypes, is differentially expressed in embryonic stem (ES) cells, ES cell‐derived, neural stem cell‐enriched cultures, and differentiated neurons, by using the five steps of thein vitroneuronal culture model of ES cell differentiation. Here, we examined the effects of PACAP on self‐renewal and cell lineage determination of neural progenitor/stem cells. PACAP inhibited the basic fibroblast growth factor‐induced proliferation (self‐renewal), as assessed by neurosphere formation. PACAP increased microtubule‐associated protein 2‐positive neurons without affecting the number of cells positive for the neural stem cell marker nestin, astrocyte marker glial fibrillary acidic protein, and oligodendrocyte marker CNPase. These results suggest that PACAP inhibits self‐renewal but, instead, induces early neuronal differentiation of neural progenitor cells.
PACAP Stimulates the Release of Interleukin‐6 in Cultured Rat Müller Cells
Authors: SEKI T. , HINOHARA Y. , TAKI C. , NAKATANI M. , OZAWA M. , NISHIMURA S. , TAKAKI A. , ITHO H. , TAKENOYA F. , SHIODA S.
Published: August 2006

Abstract: We have investigated thein vivoeffect of PACAP on rat Müller cells that are the predominant glial element in the retina. Müller cells were treated with PACAP38, either alone or in the presence of the PACAP‐selective antagonist, PACAP6–38. Cellular proliferation was determined by measuring the incorporation of bromodeoxyuridine, while interleukin‐6 (IL‐6) levels in the culture medium were examined using a B9 cell bioassay. In cultured rat Müller cells, the expression of PACAP receptor (PAC1‐R) was assessed with immunohistochemistry using a PAC1‐R‐specific antiserum. PACAP stimulated IL‐6 production in Müller cells at a concentration as low as 10−12M, which was not sufficient to induce cell proliferation. This elevation of IL‐6 production was significantly inhibited by PACAP6–38. These data suggest that Müller cells are one of the target cells for PACAP, stimulating the release of IL‐6, and providing a mechanism whereby PACAP exerts a significant neuroprotective effect in the retina.
Identification of Repressor Element 1 in Secretin/PACAP/VIP Genes
Authors: LEE LEO T.O. , LEE VIEN H.Y. , YUAN PAULA Y. , CHOW BILLY K.C.
Published: August 2006

Abstract:  Repressor element 1 (RE‐1) is a negative, cis‐acting regulatory element that interacts with the transcription factor RE‐1‐silencing transcription factor (REST). REST represses gene expression by two repressor domains that recruit other factors including mSin3 and CoREST. RE‐1 has been identified in an increasing number of neuronal‐specific genes, and recently, functional REST sites have also been discovered in VIP and PACAP genes. In the present article, we demonstrated for the first time that RE‐1 sites are present in the 5′ flanking regions of several secretin/PACAP/VIP genes by in silico analysis. This observation suggests that RE‐1/REST is a common negative regulatory pathway of this peptide family.
Retinoic Acid‐Induced Human Secretin Gene Expression in Neuronal Cells Is Mediated by Cyclin‐Dependent Kinase 1
Authors: LEE LEO T.O. , TAN‐UN K.C. , CHOW BILLY K.C.
Published: August 2006

Abstract:  Previously, we found that secretin transcript levels were induced by all‐trans retinoic acid (RA) in a neuroblastoma cell model, SH‐SY5Y. In this article, this RA‐dependent upregulation process was further investigated. In the cyclin‐dependent kinase 1 (Cdk1) inhibitor‐treated cells, the RA‐dependent induction of secretin gene expression was inhibited. Together with our previous works, we propose here that the RA responsiveness of the secretin promotor is mediated by two different pathways. The first pathway is by changing the expression levels of NFI‐C and Sp proteins while the second pathway is by modifying the phosphorylation status of both NFI‐C and Sp proteins via Cdk1.
PAC1 Receptor
Authors: MARTÍNEZ CARMEN , ARRANZ ALICIA , JUARRANZ YASMINA , ABAD CATALINA , GARCÍA‐GÓMEZ MARÍA , ROSIGNOLI FLORENCIA , LECETA JAVIER , GOMARIZ ROSA P.
Published: August 2006

Abstract: Septic shock is a systemic response to severe bacterial infections, generally caused by Gram‐negative bacterial endotoxins, with multiple manifestations such as hypotension, tissue injury, disseminated intravascular coagulation, and multi‐organ failure. All these effects, are induced by the generation of pro‐inflammatory and vasodilator mediators, cell adhesion molecules, coagulation factors, and acute‐phase proteins. Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase‐activating polypeptide (PACAP) are two immunopeptides with anti‐inflammatory properties exerted through type 1 and 2 VIP receptors (VPAC1 and VPAC2, respectively), and PACAP receptor (PAC1). The present results recapitulate the protective role of PAC1 in an experimental model of lethal endotoxemia using a knockout for the PAC1 receptor. Our results demonstrate that VIP and PACAP decrease lipopolysaccharide (LPS)‐induced interleukin‐6 (IL‐6) production, neutrophil infiltration and intercellular adhesion molecule‐1 (ICAM‐1), vascular cell adhesion molecule‐1 (VCAM‐1), and fibrinogen expression through PAC1 receptor, providing an advantage to design more specific drugs complementing standard intensive care therapy in septic shock.
Effects of Pituitary Adenylate Cyclase‐Activating Polypeptide and Vasoactive Intestinal Polypeptide on Food Intake and Locomotor Activity in the Goldfish,Carassius auratus
Authors: MATSUDA KOUHEI , MARUYAMA KEISUKE , NAKAMACHI TOMOYA , MIURA TOHRU , SHIODA SEIJI
Published: August 2006

Abstract: We investigated the effects of intracerebroventricular (ICV) and intraperitoneal (IP) administration of pituitary adenylate cyclase‐activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) on food intake in the goldfish,Carassius auratus. Cumulative food intake was significantly decreased by ICV injection of PACAP or VIP. Similarly, IP administration of PACAP or VIP induced a significant decrease in food intake. ICV injection of PACAP or VIP also induced a significant decrease in locomotor activity. These results suggest that PACAP and VIP may be involved in the regulation of feeding in goldfish.
Functional Splice Variants of the Type II G Protein–Coupled Receptor (VPAC2) for Vasoactive Intestinal Peptide in Mouse and Human Lymphocytes
Authors: MILLER ALLISON L. , VERMA DEEPTI , GRINNINGER CAROLA , HUANG MEI‐CHUAN , GOETZL EDWARD J.
Published: August 2006

Abstract:  A PCR‐based search for splice variants of the VPAC2 G protein–coupled receptor for vasoactive intestinal peptide (VIP) revealed: (a) a short‐deletion variant in mouse lymphocytes termed VPAC2de367–380, that lacks 14 amino acids in the seventh transmembrane domain, and (b) a long‐deletion variant in human lymphocytes termed VPAC2de325–438(i325–334), that lacks 114 amino acids beginning with the carboxyl‐terminal end of the third cytoplasmic loop and has 10 new carboxy‐terminal amino acids. VPAC2de367–380 binds VIP normally, but shows reduced VIP‐evoked signaling and effects on immune functions, whereas VPAC2de325–438(i325–334) shows reduced binding affinity for VIP and a complex pattern of functional differences. These splice variants may modify the immunoregulatory contributions of the VIP–VPAC2 axis.
Comparative Anatomy of PACAP‐Immunoreactive Structures in the Ventral Nerve Cord Ganglia of Lumbricid Oligochaetes
Authors: MOLNAR LASZLO , POLLAK EDIT , BOROS AKOS , REGLÖDI DORA , TAMÁS ANDREA , LENGVARI ISRVAN , ARIMURA AKIRA , LUBICS ANDREA
Published: August 2006

Abstract: By means of a whole mount immunocytochemical approach, the distribution patterns of pituitary adenylate cyclase‐activating polypeptide (PACAP)‐27 and PACAP‐38 were identified in the ventral nerve cord (VNC) ganglia of the earthwormsEisenia fetidaandLumbricus terrestris. Each PACAP form appears to occur in a distinct neuron population. Positions of these populations, as well as numbers and sizes of the constituting neurons do not essentially differ between the two species. The data suggest that in Lumbricid Oligochaetes, PACAP‐27 and PACAP‐38 neuron populations may mediate distinct physiological processes.
Breast Cancer VPAC1 Receptors
Authors: MOODY TERRY W. , JENSEN ROBERT T.
Published: August 2006

Abstract:  VIP receptors were investigated in breast cancer biopsy specimens. Twenty biopsy specimens bound 125I‐VIP with high affinity. Also, each of the 20 biopsy specimens had high amounts of VPAC1 receptor mRNA. MCF‐7 cells have VPAC1 receptors that bound the VIP chemotherapeutic conjugate, (Ala2,8,9,19,24,25,27 Nle17, Lys28)VIP‐L2‐camptothecin, with high affinity. VIP chemotherapeutic conjugates may be useful agents to inhibit the growth of breast cancer.
Lack of Trimethyltin (TMT)‐Induced Elevation of Plasma Corticosterone in PACAP‐Deficient Mice
Authors: MORITA YOSHIKO , YANAGIDA DAISUKE , SHINTANI NORIHITO , OGITA KIYOKAZU , NISHIYAMA NORITO , TSUCHIDA RIE , HASHIMOTO HITOSHI , BABA AKEMICHI
Published: August 2006

Abstract: Accumulating evidence implicates pituitary adenylate cyclase‐activating polypeptide (PACAP) in a number of stress responses. By using PACAP‐deficient mice, PACAP has been shown to have anin vivorole in the regulation of the sympathoadrenal axis, but a role in regulating the hypothalamo‐pituitary‐adrenal (HPA) axis has not been fully addressed. To elucidate the role of endogenous PACAP in HPA axis regulation during pathological conditions, mice lacking theAdcyap1gene encoding the neuropeptide PACAP (Adcyap1−/−) were injected with trimethyltin (TMT), a neurotoxin known to induce neuronal damage and several systemic responses including elevated plasma corticosterone levels. In wild‐type controls, TMT induced transient decreases in water and food intake, with a concomitant decrease in body weight; however, no significant changes were observed inAdcyap1−/−mice. Basal corticosterone levels were not significantly different between the mutant and wild‐type mice. TMT induced a marked elevation of plasma corticosterone above basal levels in wild‐type mice but no significant increase was seen inAdcyap1−/−mice. The present article suggests that PACAP is involved in the corticosterone release in some pathological conditions but not in the basal state.
Changes in PACAP Levels in the Central Nervous System after Ovariectomy and Castration
Authors: NEMETH JOZSEF , TAMAS ANDREA , JOZSA RITA , HORVATH JUDIT E. , JAKAB BALAZS , LENGVARI ISTVAN , ARIMURA AKIRA , LUBICS ANDREA , REGLÓDI DORA
Published: August 2006

Abstract: The aim of the present article was to investigate the influence of gonadectomy on pituitary adenylate cyclase‐activating polypeptide (PACAP) levels in different brain areas. In males, there seems to be an inverse relationship between gonadotropins and PACAP in the brain in the acute phase of castration: PACAP levels decreased in almost all brain areas examined within the first week after castration. In females, such pattern was observed in the hypothalamus, brain stem, and temporal cortex. In the pituitary, levels decreased only on the first day after ovariectomy, and later, as in the thalamus, increases were observed. Although the pattern of change showed gender differences, our results provide further evidence that levels of gonadotropins and possibly gonadotropin‐releasing hormone influence PACAP levels and that PACAP is involved in the regulation of gonadal functions.
Effects of Pituitary Adenylate Cyclase‐Activating Polypeptide, Vasoactive Intestinal Polypeptide, and Somatostatin on the Release of Thyrotropin from the Bullfrog Pituitary
Authors: OKADA REIKO , YAMAMOTO KAZUTOSHI , ITO YOICHI , CHARTREL NICOLAS , LEPRINCE JEROME , FOURNIER ALAIN , VAUDRY HUBERT , KIKUYAMA SAKAE
Published: August 2006

Abstract: The recent development of a specific radioimmunoassay for amphibian (bullfrog,Rana catesbeiana) thyrotropin (TSH) has made it possible to study the effects of various neuropeptides on the release of TSH from the pituitaryin vitro. Up to now, corticotropin‐releasing factor of bullfrog origin has been shown to have a potent TSH‐releasing activity, whereas gonadotropin‐releasing hormone and TSH‐releasing hormone exhibit a moderate TSH‐releasing effect on the adult, but not larval, pituitary. In the present study, the effects of pituitary adenylate cyclase‐activating polypeptide (PACAP), vasoactive intestinal polypeptide (VIP), and somatostatin (SS) on thein vitrorelease of TSH from the bullfrog pituitary were investigated. Both frog (R. ridibunda) PACAP‐38 and PACAP‐27 caused a concentration‐dependent stimulation of the release of TSH from dispersed pituitary cells during a 24‐h culture. The PACAP‐38‐ and PACAP‐27‐induced TSH release was suppressed by a simultaneous application of PACAP6–38. Application of high concentrations of PACAP6–38 alone caused a slight but significant stimulatory effect on the release of TSH. Frog VIP also stimulated TSH release from pituitary cells concentration‐dependently. Frog SS1 (homologous to mammalian somatostatin‐14) and SS2 (homologous to mammalian cortistatin) did not affect the basal release of TSH but caused a concentration‐dependent suppression of the PACAP‐38‐induced release of TSH. These results suggest the involvement of multiple neuropeptides in the regulation of the release of TSH from the amphibian pituitary.
The Three‐Dimensional Structure of the N‐Terminal Domain of Corticotropin‐Releasing Factor Receptors
Authors: PERRIN MARILYN H. , GRACE CHRISTY R. R. , RIEK ROLAND , VALE WYLIE W.
Published: August 2006

Abstract:  The corticotropin‐releasing factor (CRF) receptors, CRF‐R1 and CRF‐R2, belong to the B1 subfamily of G protein–coupled Receptors (GPCRs), including receptors for secretin, growth hormone‐releasing hormone (GHRH), vasoactive intestinal peptide (VIP), pituitary adenylate cyclase‐activating polypeptide (PACAP), calcitonin, parathyroid hormone (PTH), glucagon, and glucagon‐like peptide‐1 (GLP‐1). The peptide ligand family comprises CRF, Ucn 1, 2, and 3. CRF plays the major role in integrating the response to stress. Additionally, the ligands exhibit many effects on muscle, pancreas, heart, and the GI, reproductive, and immune systems. CRF‐R1 has higher affinity for CRF than does CRF‐R2 while both receptors bind Ucn 1 equally. CRF‐R2 shows specificity for Ucns 2 and 3. A major binding domain of the CRFRs is the N terminus/first extracellular domain (ECD1). Soluble proteins corresponding to the ECD1s of each receptor bind CRF ligands with nanomolar affinities. Our three‐dimentional (3D) nuclear magnetic resonance (NMR) structure of a soluble protein corresponding to the ECD1 of CRF‐R2β (1) identified its structural fold as a Sushi domain/short consensus repeat (SCR), stabilized by three disulfide bridges, two tryptophan residues, and an internal salt bridge (Asp65–Arg101)
. Disruption of the bridge by D65A mutation abrogates ligand recognition and results in loss of the well‐defined disulfide pattern and Sushi domain structure. NMR analysis of the ECD1 in complex with astressin identified key amino acids involved in ligand recognition. Mutation of some of these residues in the full‐length receptor reduces its affinity for CRF ligands. A structure‐based sequence comparison shows conservation of key amino acids in all the B1 subfamily receptors, suggesting a corresponding conservation of a Sushi domain structural fold of their ECD1s.
VIP and Tolerance Induction in Autoimmunity
Authors: ROSIGNOLI F. , TORROBA M. , JUARRANZ Y. , GARCÍA‐GÓMEZ M. , MARTINEZ C. , GOMARIZ R.P. , PÉREZ‐LEIRÓS C. , LECETA J.
Published: August 2006

Abstract:  Vasoactive intestinal peptide (VIP)
is a potent anti‐inflammatory agent with immunoregulatory properties, skewing the immune response to a Th2 pattern of cytokine production. Here, we studied the effect of treatment with VIP in the development of diabetes in nonobese diabetic (NOD)
mice, an animal model of type 1 diabetes. Mice treated with VIP from 4 weeks of age did not develop diabetes and showed milder insulitis than nontreated mice. The protective mechanism of VIP was associated with a reduction in the circulating levels of Th1 cytokines. In the pancreas of VIP‐treated animals, regulatory T cell markers predominate, as indicated by the upregulation of FoxP3 and transforming growth factor‐β (TGF‐β), and the downregulation of the transcription factor, T‐bet. These findings indicate that VIP restores tolerance to pancreatic islets by promoting the local differentiation and function of regulatory T cells.
Complexing Receptor Pharmacology
Authors: SEXTON PATRICK M. , MORFIS MARIA , TILAKARATNE NANDA , HAY DEBBIE L. , UDAWELA MADHARA , CHRISTOPOULOS GEORGE , CHRISTOPOULOS ARTHUR
Published: August 2006

Abstract: The most well‐characterized subgroup of family B G protein–coupledreceptors (GPCRs) comprises receptors for peptide hormones, such as secretin, calcitonin (CT), glucagon, and vasoactive intestinal peptide (VIP). Recent data suggest that many of these receptors can interact with a novel family of GPCR accessory proteins termedreceptor activity modifying proteins (RAMPs). RAMP interaction with receptors can lead to a variety of actions that include chaperoning of the receptor protein to the cell surface as is the case for the calcitonin receptor‐like receptor (CLR) and the generation of novel receptor phenotypes. RAMP heterodimerization with the CLR and related CT receptor is required for the formation of specific CT gene‐related peptide, adrenomedullin (AM) or amylin receptors. More recent work has revealed that the specific RAMP present in a heterodimer may modulate other functions such as receptor internalization and recycling and also the strength of activation of downstream signaling pathways. In this article we review our current state of knowledge of the consequence of RAMP interaction with family B GPCRs.
VIP Protects Th2 Cells by Downregulating Granzyme B Expression
Authors: SHARMA VIKAS , DELGADO MARIO , GANEA DOINA
Published: August 2006

Abstract:  Selective differentiation of Th1/Th2 effectors contributes to cell‐ or antibody‐mediated immunity. Vasoactive intestinal peptide (VIP) induces Th2 responses by promoting Th2 differentiation and survival. Here we investigate the mechanisms of VIP‐induced Th2 survival. Microarray and protein data indicate that VIP prevents the upregulation of granzyme B (GrB) in Th2, but not Th1 effectors. This is the first report of GrB expression and of its involvement in activation‐induced apoptosis of T helper cells. The enhanced responsiveness of Th2 cells to VIP is probably due to the higher expression of VIP receptors and alternative signaling pathways. This study identifies GrB as a new significant player in Th1/Th2 activation‐induced cell death, and characterizes the mechanisms for the protective effect of VIP on Th2 survival.
Pleiotropic Functions of PACAP in the CNS
Authors: SHIODA SEIJI , OHTAKI HIROKAZU , NAKAMACHI TOMOYA , DOHI KENJI , WATANABE JUN , NAKAJO SHIGEO , ARATA SATORU , KITAMURA SHINJI , OKUDA HIROMI , TAKENOYA FUMIKO , KITAMURA YOSHITAKA
Published: August 2006

Abstract:  Pituitary adenylate cyclase‐activating polypeptide (PACAP) is a pleiotropic neuropeptide that belongs to the secretin/glucagon/vasoactive intestinal peptide (VIP) family. PACAP prevents ischemic delayed neuronal cell death (apoptosis) in the hippocampus. PACAP inhibits the activity of the mitogen‐activated protein kinase (MAPK) family, especially JNK/SAPK and p38, thereby protecting against apoptotic cell death. After the ischemia‐reperfusion, both pyramidal cells and astrocytes increased their expression of the PACAP receptor (PAC1‐R). Reactive astrocytes increased their expression of PAC1‐R, released interleukin‐6 (IL‐6) that is a proinflammatory cytokine with both differentiation and growth‐promoting effects for a variety of target cell types, and thereby protected neurons from apoptosis. These results suggest that PACAP itself and PACAP‐stimulated secretion of IL‐6 synergistically inhibit apoptotic cell death in the hippocampus. The PAC1‐R is expressed in the neuroepithelial cells from early developmental stages and in various brain regions during development. We have recently found that PACAP, at physiological concentrations, induces differentiation of mouse neural stem cells into astrocytes. Neural stem cells were prepared from the telencephalon of mouse embryos and cultured with basic fibroblast growth factor. The PAC1‐R immunoreactivity was demonstrated in the neural stem cells. When neural stem cells were exposed to PACAP, about half of these cells showed glial fibrillary acidic protein (GFAP) immunoreactivity. This phenomenon was significantly antagonized by a PAC1‐R antagonist (PACAP6‐38), indicating that PACAP induces differentiation of neural stem cell into astrocytes. Other our physiological studies have demonstrated that PACAP acts on PAC1‐R in mouse neural stem cells and its signal is transmitted to the PAC1‐R‐coupled G protein Gq but not to Gs. These findings strongly suggest that PACAP plays very important roles in neuroprotection in adult brain as well as astrocyte differentiation during development.
The Prenatal Expression of Secretin Receptor
Authors: SIU FRANCIS K.Y. , SHAM M.H. , CHOW BILLY K.C.
Published: August 2006

Abstract:  Secretin is a classical gastrointestinal peptide while its neuroactive functions in the central nervous system have recently been consolidated. In the past, there was little information regarding the expression of secretin receptor in prenatal development. In this article, using mouse embryos and by in situ hybridization, secretin receptor transcripts were detected in several developing brain regions including the cerebellar primordium and choroid plexus. In the developing intestine, secretin receptor is present in the epithelial lining of the villi and the inner circular muscle. Interestingly, the transcripts for secretin receptor were also detected in the epicardium and myocardium of the developing heart as well as the glomerulus and collecting duct in the developing kidney. Taken together, our data suggest a potential pleiotrophic role of secretin during embryonic development.
Characterization of the New Photoaffinity Probe (Bz2‐K24)‐VIP
Authors: TAN YOSSAN‐VAR , COUVINEAU ALAIN , LACAPERE JEAN JACQUES , LABURTHE MARC
Published: August 2006

Abstract:  Site‐directed mutagenesis and molecular modeling demonstrated that the N‐terminal ectodomain of the VPAC1 receptor is a major site of vasoactive intestinal peptide (VIP) binding. Previous studies with the [Bpa6]‐VIP and [Bpa22]‐VIP probes (substitution with the photoactivable Bpa for the residues 6 and 22 in VIP) showed spatial approximation between the amino acids 6 and 22 of VIP and the 104‐108 and 109‐119 sequences within the N‐terminal ectodomain of the receptor, respectively. Here, we characterize the new probe (Bz2‐K24)‐VIP (substitution with the photoreactive Bz2‐K for the residue 24 in VIP). After photolabeling and sequential digestions of the receptor, the 121‐133 sequence of the N‐terminal ectodomain was identified as the site of interaction. The N‐terminal ectodomain of the VPAC1 receptor is therefore an affinity trap for the central part of VIP, at least between residues 6 and 24.
PACAP Receptor (PAC1‐R) Expression in Rat and Rhesus Monkey Thymus
Authors: TOKUDA N. , ARUDCHELVAN Y. , SAWADA T. , ADACHI Y. , FUKUMOTO T. , YASUDA M. , SUMIDA H. , SHIODA S. , FUKUDA T. , ARIMA A. , KUBOTA S.
Published: August 2006

Abstract: The expression of PACAP receptor (PAC1‐R) was investigated in the thymus of rats and rhesus monkeys. In the rat thymus, PAC1‐R positive cells were found in the intermediate type of thymic epithelial cells of the medulla. PAC1‐R‐positive cells were also seen in the thymic medulla of the rhesus monkey. The thymus showed unusual structures in some rhesus monkey dams (F0) and offspring (F1) exposed to 2, 3, 7, 8‐tetrachlorodibenzo‐p‐dioxin (TCDD). Additionally, in these rhesus monkeys, PAC1‐R expression was different from that in the control thymus.
Involvement of Protein Kinase C in the PACAP‐Induced Differentiation of Neural Stem Cells into Astrocytes
Authors: WATANABE JUN , OHNO FUSAKO , SHIODA SEIJI , KIKUYAMA SAKAE , NAKAYA KAZUYASU , NAKAJO SHIGEO
Published: August 2006

Abstract: Expression of members of the conventional protein kinase C (cPKC) family in the differentiation of mouse neural stem cells (NSCs) induced by pituitary adenylate cyclase‐activating polypeptide (PACAP) was investigated. In particular, expression of the α and β subtypes of cPKC in NSCs was observed. In response to activation by PACAP, cPKCβ transiently increased twofold by day 2 and returned to basal levels by day 4, suggesting that cPKCβ might be responsible for the differentiation process.
Role of Two Genes Encoding PACAP in Early Brain Development in Zebrafish
Authors: WU SHENG , ADAMS BRUCE A. , FRADINGER ERICA A. , SHERWOOD NANCY M.
Published: August 2006

Abstract:  To study the role of pituitary adenylate cyclase‐activating polypeptide (PACAP) in early brain development, we examined PACAP and its receptors for first expression and then separately knocked down the two forms of PACAP in zebrafish where development is rapid and observable. We injected morpholinos (antisense oligonucleotides) into fertilized eggs to block PACAP. Morphological changes in the brain were observed in embryos at 27 h post fertilization (hpf). Using in situ hybridization of early brain marker genes, we found that the most striking effects were an increase in pax2.1 expression in eye stalks associated with absence of either form of PACAP or an increase in eng2 and fgf8 in the midbrain–hindbrain boundary after loss of PACAP2. These marker genes are among the earliest factors in the formation of the midbrain–hindbrain boundary, an early organizing center. We suggest that PACAP is a target gene with feedback inhibition on pax2.1, eng2, or fgf8 in specific brain areas. In the hindbrain, the absence of either form of PACAP had little effect, as shown by expression of ephA4 and meis1.1. During midbrain development, our evidence suggests that PACAP1 can activate mbx. In both the diencephalon and/or forebrain, lack of PACAP1 or PACAP2 led to an increase in fgf8, again suggesting a suppressive effect of PACAP during development on these important genes that help to define cells in the forebrain. The early expression of transcripts for PACAP and its receptors by 0.5–6 hpf make both PACAP1 and PACAP2 candidates for factors that influence brain development.
A Role for Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) in Detrusor Hyperreflexia after Spinal Cord Injury (SCI)
Authors: ZVARA PETER , BRAAS KAREN M. , MAY VICTOR , VIZZARD MARGARET A.
Published: August 2006

Abstract:  Intrathecal administration of the PAC1 receptor antagonist, PACAP6‐38 (10 nM), significantly (P≤ 0.05) reduced intermicturition, threshold and micturition pressures in chronic (3–6 weeks) spinal cord injured rats but intravesical administration (100–300 nM) was without effect. Intrathecal PACAP6‐38 reduced the number and amplitude of nonvoiding bladder contractions observed after spinal cord injury (SCI). PACAP may contribute to detrusor hyperreflexia induced by SCI and PACAP antagonists may be a novel approach to reduce detrusor hyperreflexia after SCI.
Hospital Disaster Preparedness in Los Angeles County
Authors: Kaji Amy H. , Lewis Roger J.
Published: August 2006

Background

There are no standardized measures of hospital disaster preparedness or hospital “surge capacity.”

Objectives

To characterize disaster preparedness among a cohort of hospitals in Los Angeles County, focusing on practice variation, plan characteristics, and surge capacity.

Methods

This was a descriptive, cross‐sectional survey study, followed by on‐site verification. Forty‐five 9‐1‐1 receiving hospitals in Los Angeles County, CA, participated. Evaluations of hospital disaster plan structure, vendor agreements, modes of communication, medical and surgical supplies, involvement of law enforcement, mutual aid agreements with other facilities, drills and training, surge capacity (assessed by monthly emergency department diversion status, available beds, ventilators, and isolation rooms), decontamination capability, and pharmaceutical stockpiles were assessed by survey.

Results

Forty‐three of 45 hospital plans (96%) were based on the Hospital Emergency Incident Command System, and the majority had protocols for hospital lockdown (100%), canceling elective surgeries (93%), early discharge (98%), day care for children of staff (88%), designating victim overflow areas (96%), and predisaster “preferred” vendor agreements (96%). All had emergency medical services–compatible radios and more than three days' worth of supplies. Fewer hospitals involved law enforcement (56%) or had mutual aid agreements with other hospitals (20%) or long‐term care facilities (7%). Although the vast majority (96%) conducted multiagency drills, only 16% actually involved other agencies in their disaster training. Only 13 of 45 hospitals (29%) had a surge capacity of greater than 20 beds. Less than half (42%) had ten or more isolation rooms, and 27 hospitals (60%) were on diversion greater than 20% of the time. Thirteen hospitals (29%) had immediate access to six or more ventilators. Less than half had warm‐water decontamination (42%), while approximately one half (51%) had a chemical antidote stockpile and 42% had an antibiotic stockpile.

Conclusions

Among hospitals in Los Angeles County, disaster preparedness and surge capacity appear to be limited by a failure to fully integrate interagency training and planning and a severely limited surge capacity, although there is a generally high level of availability of equipment and supplies.
Characteristics of Medical Surge Capacity Demand for Sudden‐impact Disasters
Authors: Stratton Samuel J. , Tyler Robin D.
Published: August 2006

Objectives

To describe the characteristics of the demand for medical care during sudden‐impact disasters, focusing on local U.S. communities and the initial phases of sudden‐impact disasters.

Methods

Established databases and published reports were used as data sources. Data were obtained to describe the baseline capacity of the U.S. medical system. Information for the initial phases of a sudden‐impact disaster was sought to allow for characterization of the length of time before a U.S. community can expect arrival of outside assistance, the expected types of medical surge demands, the expected time for the peak in medical‐care demand, and the expected health system access points.

Results

The earliest that outside assistance arrived for a community subject to a sudden‐impact disaster was 24 hours, with a range from 24 to 96 hours. After sudden‐impact disasters, 84% to 90% of health care demand was for conditions that were managed on an ambulatory basis. Emergency departments (EDs) were the access point for care, with peak demand time occurring within 24 hours. The U.S. emergency care system was functioning at relatively full capacity on the basis of data collected for the study that showed that annually, 90% of EDs were boarding admitted inpatients, and 75% were diverting ambulances.

Conclusions

As part of planning for sudden‐impact disasters, communities should be expected to sustain medical services for 24 hours, and up to 96, before arrival of external resources. For effective medical surge‐capacity response during sudden‐impact disasters, there should be a priority for emergency medical care with a focus on ambulatory injuries and illnesses.
Sarcolemmal ion currents and sarcoplasmic reticulum Ca2+content in ventricular myocytes from the cold stenothermic fish, the burbot(Lota lota)
Authors: Shiels Holly A. , Paajanen Vesa , Vornanen Matti
Published: August 2006

The burbot (Lota lota) is a cold stenothermic fish species whose heart is adapted to function in the cold. In this study we use whole-cell voltage-clamp techniques to characterize the electrophysiological properties of burbot ventricular myocytes and to test the hypothesis that changes in membrane currents and intracellular Ca2+ cycling associated cold-acclimation in other fish species are routine for stenothermic cold-adapted species. Experiments were performed at 4°C, which is the body temperature of burbot for most of the year, and after myocytes were acutely warmed to 11°C, which is in the upper range of temperatures experienced by burbot in nature. Results on K+ channels support our hypothesis as the relative density of K-channel conductances in the burbot heart are similar to those found for cold-acclimated cold-active fish species. IK1 conductance was small (39.2±5.4 pS pF-1 at 4°C and 71.4±1.7 pS pF-1 at 11°C)and IKr was large (199±27 pS pF-1 at 4°C and 320.3±8 pS pF-1 at 11°C) in burbot ventricular myocytes. We found high Na+-Ca2+ exchange(NCX) activity (35.9±6.3 pS pF-1 at 4°C and 58.6±8.4 pS pF-1 at 11°C between -40 and 20 mV),suggesting that it may be the primary pathway for sarcolemmal (SL)Ca2+ influx in this species. In contrast, the density(ICa, 0.81±0.13 pA pF-1 at 4°C, and 1.35±0.18 pA pF-1 at 11°C) and the charge(QCa, 0.24±0.043 pC pF-1 at 4°C and 0.21±0.034 pC pF-1 at 11°C) carried by the l-type Ca2+ current was small. Our results on sarcolemmal ion currents in burbot ventricular myocytes suggest that cold stenothermy and compensative cold-acclimation involve many of the same subcellular adaptations that culminate in enhanced excitability in the cold.
Acclimation to different thermal conditions in a northerly wintering shorebird is driven by body mass-related changes in organ size
Authors: Vézina François , Jalvingh Kirsten M. , Dekinga Anne , Piersma Theunis
Published: August 2006

Seasonal acclimatization and experimental acclimation to cold in birds typically results from increased shivering endurance and elevated thermogenic capacity leading to improved resistance to cold. A wide array of physiological adjustments, ranging from biochemical transformations to organ mass variations, are involved in this process. Several studies have shown that improved cold endurance is accompanied by increases in summit metabolic rate(Msum), a measure of maximal heat production and an indicator of the level of sustainable thermogenic capacity. However, improved endurance to cold can also be achieved without significant changes in Msum. The same is true for basal metabolic rate (BMR),which is known to increase in association with cold acclimatization or acclimation in some species but not in others. We investigated cold acclimation in a migrant shorebird known for extreme physiological flexibility, the red knot (Calidris canutus, the northerly wintering subspecies islandica). We measured BMR and Msumover two months in birds caught in the wild and transferred to experimentally controlled conditions representative of aspects of their seasonal thermal environment (two groups at constant 25°C, one group at constant 4°C and two groups experiencing variable outdoor temperatures). Birds maintained in both cold and variable ambient temperatures showed a 14-15% higher body mass, 33-45% higher food intake, and 26% and 13% elevations in BMR and Msum, respectively, compared with birds kept at thermoneutrality. These results, together with data on alimentary tract size and pectoral muscle thickness measured by ultrasonography, suggest that red knots acclimate to cold primarily through modulation of (lean) body mass components. Heavier individuals have larger muscles, which allow higher maximal heat production and better thermal compensation. Cold acclimation effects on BMR are most probably due to changes in the size of visceral organs, although not the alimentary tract in this specific case. The liver,known for its thermogenic capacity, is a probable candidate. Overall, our results indicate that relatively small changes in body mass and muscle size allow enough reserve capacity in terms of heat production to cope with typical wintering ambient temperature variations as measured on the red knot's wintering grounds.
Molecular and cellular characterization of a new aquaporin, AQP-x5,specifically expressed in the small granular glands ofXenopusskin
Authors: Kubota Makoto , Hasegawa Takahiro , Nakakura Takashi , Tanii Haruna , Suzuki Masakazu , Tanaka Shigeyasu
Published: August 2006

A new toad aquaporin (AQP) cDNA was cloned from a cDNA library constructed from the ventral skin of Xenopus laevis. This AQP (XenopusAQP-x5) consisted of 273 amino acid residues with a high sequence homology to mammalian AQP5. The predicted amino acid sequence contained the two conserved Asn-Pro-Ala motifs found in all major intrinsic protein (MIP) family members and six putative transmembrane domains. The sequence also contained a mercurial-sensitive cysteine and a putative phosphorylation motif site for protein kinase A at Ser-257. The swelling assay using Xenopus oocytes revealed that AQP-x5 facilitated water permeability. Expression of AQP-x5 mRNA was restricted to the skin, brain, lungs and testes. Immunofluorescence and immunoelectron microscopical studies using an anti-peptide antibody (ST-156)against the C-terminal region of the AQP-x5 protein revealed the presence of immunopositive cells in the skin, with the label predominately localized in the apical plasma membrane of the secretory cells of the small granular glands. These glands are unique both in being close to the epidermal layer of the skin and in containing mitochondria-rich cells with vacuolar H+-ATPase dispersed among its secretory cells. Results from immunohistochemical experiments on the mucous or seromucous glands of several other anurans verified this result. We conclude that the presence of AQP-x5 in the apical plasma membrane of the small granular glands suggests its involvement in water secretion from the skins. The physiological roles of the AQP-x5 protein in the small or mucous glands are discussed.
Regulation of osmotic stress transcription factor 1 (Ostf1) in tilapia(Oreochromis mossambicus) gill epithelium during salinity stress
Authors: Fiol Diego F. , Chan Stephanie Y. , Kültz Dietmar
Published: August 2006

Mechanisms of induction of osmotic stress transcription factor 1 (Ostf1)were analyzed in gill epithelium of tilapia exposed to salinity stress. Experiments with primary cultures of gill epithelial cells revealed that hyperosmotic Ostf1 induction was independent of systemic factors. In addition,the synthetic glucocorticoid receptor agonist dexamethasone did not affect Ostf1 levels, arguing against cortisol being the signal for Ostf1 induction during hyperosmotic stress. Exposure of primary gill cell cultures to a hyperosmotic agent that is cell permeable and non-hypertonic (glycerol) did not trigger Ostf1 induction. However, when gill cells were exposed to hypertonicity (either in the form of NaCl or other forms) Ostf1 was rapidly and significantly induced. Analysis of hnRNA and mRNA levels revealed that Ostf1 upregulation in gill cells of intact fish and primary cultures of gill epithelial cells was mediated by transient mRNA stabilization. In addition to the initial transient mRNA stabilization a subsequent transcriptional induction of Ostf1 was observed. In cultured gill cells increase in Ostf1 mRNA synthesis was stable and very potent, whereas in gill cells of intact fish this increase was transient. This observation suggests positive feedback by Ostf1 or one of its targets and negative feedback by systemic factors on Ostf1 transcription.

We conclude that Ostf1 induction in gill epithelial cells of tilapia exposed to salinity stress (1) is independent of cortisol or other systemic factors; (2) depends on hypertonicity as the signal; and (3) is based on transient mRNA stabilization. Moreover, our data on primary cell cultures show that systemic signals are necessary to prevent sustained transcriptional induction of Ostf1 during hyperosmotic stress, indicating feedback regulation and a high degree of complexity of osmosensing and signaling networks in euryhaline fishes.
Beauty in the eye of the beholder: the two blue opsins of lycaenid butterflies and the opsin gene-driven evolution of sexually dimorphic eyes
Authors: Sison-Mangus Marilou P. , Bernard Gary D. , Lampel Jochen , Briscoe Adriana D.
Published: August 2006

Although previous investigations have shown that wing coloration is an important component of social signaling in butterflies, the contribution of opsin evolution to sexual wing color dichromatism and interspecific divergence remains largely unexplored. Here we report that the butterfly Lycaena rubidus has evolved sexually dimorphic eyes due to changes in the regulation of opsin expression patterns to match the contrasting life histories of males and females. The L. rubidus eye contains four visual pigments with peak sensitivities in the ultraviolet (UV;λ max=360 nm), blue (B; λmax=437 nm and 500 nm, respectively) and long (LW; λmax=568 nm) wavelength range. By combining in situ hybridization of cloned opsinencoding cDNAs with epi-microspectrophotometry, we found that all four opsin mRNAs and visual pigments are expressed in the eyes in a sex-specific manner. The male dorsal eye, which contains only UV and B (λmax=437 nm)visual pigments, indeed expresses two short wavelength opsin mRNAs, UVRh and BRh1. The female dorsal eye, which also has the UV and B (λmax=437 nm) visual pigments, also contains the LW visual pigment, and likewise expresses UVRh, BRh1 and LWRh mRNAs. Unexpectedly, in the female dorsal eye, we also found BRh1 co-expressed with LWRh in the R3-8 photoreceptor cells. The ventral eye of both sexes, on the other hand, contains all four visual pigments and expresses all four opsin mRNAs in a non-overlapping fashion. Surprisingly, we found that the 500 nm visual pigment is encoded by a duplicate blue opsin gene, BRh2. Further, using molecular phylogenetic methods we trace this novel blue opsin gene to a duplication event at the base of the Polyommatine+Thecline+Lycaenine radiation. The blue opsin gene duplication may help explain the blueness of blue lycaenid butterflies.
Decreased expression of myogenic transcription factors and myosin heavy chains inCaenorhabditis elegansmuscles developed during spaceflight
Authors: Higashibata Akira , Szewczyk Nathaniel J. , Conley Catharine A. , Imamizo-Sato Mari , Higashitani Atsushi , Ishioka Noriaki
Published: August 2006

The molecular mechanisms underlying muscle atrophy during spaceflight are not well understood. We have analyzed the effects of a 10-day spaceflight on Caenorhabditis elegans muscle development. DNA microarray, real-time quantitative PCR, and quantitative western blot analyses revealed that the amount of MHC in both body-wall and pharyngeal muscle decrease in response to spaceflight. Decreased transcription of the body-wall myogenic transcription factor HLH-1 (CeMyoD) and of the three pharyngeal myogenic transcription factors, PEB-1, CEH-22 and PHA-4 were also observed. Upon return to Earth animals displayed reduced rates of movement, indicating a functional defect. These results demonstrate that C. elegans muscle development is altered in response to spaceflight. This altered development occurs at the level of gene transcription and was observed in the presence of innervation,not simply in isolated cells. This important finding coupled with past observations of decreased levels of the same myogenic transcription factions in vertebrates after spaceflight raises the possibility that altered muscle development is a contributing factor to spaceflight-induced muscle atrophy in vertebrates.