Vasoactive Intestinal Peptide Receptor-1 Research Articles

Development of a New Enzyme-Linked Immunosorbent Assay (ELISA) for Measuring the Content of PACAP in Mammalian Tissue and Plasma.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a naturally occurring neuropeptide found in both the central and peripheral nervous systems of vertebrates. Recent studies have revealed the presence of PACAP and its corresponding receptors, namely, the pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1R), vasoactive intestinal peptide receptor 1 (VIPR1), and vasoactive intestinal peptide receptor 2 (VIPR2), in various structures implicated in migraine pathophysiology, including sensory trigeminal neurons. Human studies have demonstrated that when infused, PACAP can cause dilation of cranial vessels and result in delayed migraine-like attacks. In light of this, we present a novel ELISA assay that has been validated for quantifying PACAP in tissue extracts and human plasma. Using two well characterized antibodies specifically targeting PACAP, we successfully developed a sandwich ELISA assay, capable of detecting and accurately quantifying PACAP without any cross-reactivity to closely related peptides. The quantification range was between 5.2 pmol/L and 400 pmol/L. The recovery in plasma ranged from 98.2% to 100%. The increasing evidence pointing to the crucial role of PACAP in migraine pathophysiology necessitates the availability of tools capable of detecting changes in the circulatory levels of PACAP and its potential application as a reliable biomarker.

β-Arrestin-independent endosomal cAMP signaling by a polypeptide hormone GPCR

Many G protein-coupled receptors (GPCRs) initiate a second phase of stimulatory heterotrimeric G protein (Gs)-coupled cAMP signaling after endocytosis. The prevailing current view is that the endosomal signal is inherently β-arrestin-dependent because β-arrestin is necessary for receptor internalization and, for some GPCRs, to prolong the endosomal signal. Here we revise this view by showing that the vasoactive intestinal peptide receptor 1 (VIPR1), a secretin-family polypeptide hormone receptor, does not require β-arrestin to internalize or to generate an endosomal signal. β-Arrestin instead resolves the plasma membrane and endosomal signaling phases into sequential cAMP peaks by desensitizing the plasma membrane phase without affecting the endosomal phase. This appears to occur through the formation of functionally distinct VIPR1–β-arrestin complexes at each location that differ in their phosphorylation dependence. We conclude that endosomal GPCR signaling can occur in the absence of β-arrestin and that β-arrestin sculpts the spatiotemporal profile of cellular GPCR–G protein signaling through location-specific remodeling of GPCR–β-arrestin complexes.

Association of vasoactive intestinal peptide receptor 1 gene polymorphism with layer economic traits in Rhode Island Red chicken

The research work was conducted to determine allelic polymorphism of vasoactive intestinal peptide receptor-1 (VIPR-1) gene and its association with layer traits in Rhode Island Red (RIR) chicken. Blood samples were collected from pullets (n=111) belonging to five hatches. Data on body weight at 20 weeks of age (BW20) and layer economic traits, viz. age at sexual maturity (ASM), egg weight at 28 (EW28) and 40 weeks (EW40) of age, and egg production up to 40 weeks of age (EP40)) were recorded. Genomic DNA was isolated by phenol chloroform extraction method. Samples were amplified for product sizes of 364, 434 and 486 bp of VIPR-1 gene. Amplified regions were digested by TaiI, HhaI and TaqI restriction enzymes. Digested fragments of TaiI and HhaI revealed monomorphism, whereas TaqI showed polymorphism. Allelic frequencies for polymorphic locus were 0.98 (A) and 0.02 (B) and genotypic frequencies for AA and AB were 0.96 and 0.04, respectively. The BW20 and layer traits (ASM, EW28, EW40 and EP40) were analysed by least-squares analysis of variance taking sire as random and hatch as fixed effect. Average ASM and egg production up to 40 weeks of age were 135.19±1.15 days and 124.55±1.94 eggs, respectively. Least-square analysis of variance had revealed significant effect of hatch on ASM, EW28 and EP40. However, effect of TaqI-RFLP genotypes was non-significant on layer traits. Further investigations on a larger sample basis are suggested to confirm effect of this mutation on layer traits as molecular marker in RIR chicken.

Research Note: Association of VIPR-1 gene polymorphism with growth traits in meat type Japanese quail (Coturnix Japonica)

This study aimed to analyze the polymorphism of the vasoactive intestinal peptide receptor-1 (VIPR-1) gene and its association with growth traits in quail using the PCR-RFLP and sequencing techniques. Genomic DNA was extracted from blood samples of 36 female Savimalt (SV) quails and 49 female French Giant (FG) quails. Growth traits were measured and used for VIPR-1 gene analysis, as body weight (BW), tibia length (TL), chest width (CW), chest depth (CD), sternum length (SL), body length (BL), and tibia circumference (TC). The results showed that 2 SNPs (BsrD I and HpyCH4 IV) were detected in exon 4 to 5 and exon 6 to 7 of the VIPR-1 gene, respectively. The results of association showed that the BsrD I site was not significantly associated with growth traits at 3 or 5 wk of age in the SV strain (P < 0.05), while the BsrD I site was significantly associated with BL at 3 or 5 wk of age in FG (P < 0.05). The HpyCH4 IV site was significantly associated with TL, CW, CD, SL, and BL at 3 wk of age in the SV strain (P < 0.05), while the HpyCH4 IV site was significantly correlated with BW, CW, SL, and BL at 5 wk of age in SV (P < 0.05). The HpyCH4 IV site was significantly associated with TL and TC at 3 wk of age in FG (P < 0.05), while the HpyCH4 IV site was significantly associated with TC at 5 wk of age in FG (P < 0.05). Four haplotype combinations based on 2 SNPs showed significantly association with BW, CW, CD, SL, BL, and TC at 3 or 5 wk of age in SV (P < 0.05). There was not significant association between 3 haplotype combinations with growth trait at 3 or 5 wk of age in FG (P > 0.05). In conclusion, the VIPR-1 gene could be used as a molecular genetic marker to improve growth traits in quail.

1720P VIPR1 as a novel prognostic biomarker and its correlation with immune infiltrates in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is one of the deadliest cancers worldwide. Extensive efforts are made to search for new biomarkers to screen for immunotherapy candidates and predict the prognosis. The vasoactive intestinal peptide receptor-1 (VIPR1) has substantial but contradicting effects among different cancers. Herein, we analyzed the association of VIPR1 with immune inhibitory components to understand its immune landscape.

VIPR1 promoter methylation promotes transcription factor AP-2α binding to inhibit VIPR1 expression and promote hepatocellular carcinoma cell growth in vitro

To explore the transcriptional regulation mechanism and biological function of low expression of vasoactive intestinal peptide receptor 1 (VIPR1) in hepatocellular carcinoma (HCC). We constructed plasmids carrying wild-type VIPR1 promoter or two mutant VIPR1 promoter sequences for transfection of the HCC cell lines Hep3B and Huh7, and examined the effect of AP-2α expression on VIPR1 promoter activity using dual-luciferase reporter assay. Pyrosequencing was performed to detect the changes in VIPR1 promoter methylation level in HCC cells treated with a DNA methyltransferase inhibitor (DAC). Chromatin immunoprecipitation was used to evaluate the binding ability of AP-2α to VIPR1 promoter. Western blotting was used to assess the effect of AP-2α knockdown on VIPR1 expression and examine the differential expression of VIPR1 in the two cell lines. The effects of VIPR1 overexpression and knockdown on the proliferation, cell cycle and apoptosis of HCC cells were analyzed using CCK8 assay and flow cytometry. We also observed the growth of HCC xenograft with lentivirus-mediated over-expression of VIPR1 in nude mice. Compared with the wild-type VIPR1 promoter group, co-transfection with the vector carrying two promoter mutations and the AP-2α-over-expressing plasmid obviously restored the luciferase activity in HCC cells (P < 0.05). DAC treatment of the cells significantly decreased the methylation level of VIPR1 promoter and inhibited the binding of AP-2α to VIPR1 promoter (P < 0.01). The HCC cells with AP-2α knockdown showed increased VIPR1 expression, which was lower in Huh7 cells than in Hep3B cells. VIPR1 overexpression in HCC cells caused significant cell cycle arrest in G2/M phase (P < 0.01), promoted cell apoptosis (P < 0.001), and inhibited cell proliferation (P < 0.001), while VIPR1 knockdown produced the opposite effects. In the tumor-bearing nude mice, VIPR1 overexpression in the HCC cells significantly suppressed the increase of tumor volume (P < 0.001) and weight (P < 0.05). VIPR1 promoter methylation in HCC promotes the binding of AP-2α and inhibits VIPR1 expression, while VIPR1 overexpression causes cell cycle arrest, promotes cell apoptosis, and inhibits cell proliferation and tumor growth.

Generation of KS-133 as a Novel Bicyclic Peptide with a Potent and Selective VIPR2 Antagonist Activity that Counteracts Cognitive Decline in a Mouse Model of Psychiatric Disorders.

Worldwide, more than 20 million people suffer from schizophrenia, but effective and definitive new therapeutic drugs/treatments have not been established. Vasoactive intestinal peptide receptor 2 (VIPR2) might be an attractive drug target for the treatment of schizophrenia because both preclinical and clinical studies have demonstrated a strong link between high expression/overactivation of VIPR2 and schizophrenia. Nevertheless, VIPR2-targeting drugs are not yet available. VIPR2 is a class-B G protein-coupled receptor that possesses high structural homology to its subtypes, vasoactive intestinal peptide receptor 1 (VIPR1) and pituitary adenylate cyclase-activating polypeptide type-1 receptor (PAC1). These biological and structural properties have made it difficult to discover small molecule drugs against VIPR2. In 2018, cyclic peptide VIpep-3, a VIPR2-selective antagonist, was reported. The aim of this study was to generate a VIpep-3 derivative for in vivo experiments. After amino acid substitution and structure optimization, we successfully generated KS-133 with 1) a VIPR2-selective and potent antagonistic activity, 2) at least 24 h of stability in plasma, and 3) in vivo pharmacological efficacies in a mouse model of psychiatric disorders through early postnatal activation of VIPR2. To the best of our knowledge, this is the first report of a VIPR2-selective antagonistic peptide that counteracts cognitive decline, a central feature of schizophrenia. KS-133 may contribute to studies and development of novel schizophrenia therapeutic drugs that target VIPR2.

Overexpressing miR-122-5p Inhibits the Relaxation of Vaginal Smooth Muscle in Female Sexual Arousal Disorder by Targeting Vasoactive Intestinal Peptide Receptor 1.

IntroductionFemale sexual arousal disorder (FSAD) is a common issue causing physical and psychological pain, but it has no standard diagnostic criteria or treatment. So its pathogenesis desiderates to be explored.AimTo investigate the specific function of miR-122-5p in FSAD.Methods18 subjects were grouped into FSAD and normal control groups according to the Chinese version of the Female Sexual Function Index, and the expression levels of miR-122-5p and vasoactive intestinal peptide receptor 1 (VIPR1) protein in their tissue were verified through real-time quantitative polymerase chain reaction (qRT-PCR) and western blot (WB) analysis. Then in vitro experiment, miR-122-5p was overexpressed or inhibited in rat vaginal smooth muscle cells (SMCs). The relaxation of rat vaginal SMCs was reflected by the cell morphology, intracellular free cytosolic calcium ion (Ca2+) levels, cell proliferation and apoptosis, together with the cyclic adenosine monophosphate (cAMP) concentration and protein kinase A (PKA) activities. Additionally, the expression levels of relaxation-related proteins, including VIPR1, stimulatory G protein (Gs), adenylate cyclase (AC), and PKA, were detected based on WB analysis. Furthermore, a rescue experiment that simultaneously overexpressed or silenced miR-122-5p and VIPR1 was conducted, and all the indicators were evaluated.Main Outcomes MeasureThe expression level of VIPR1 and downstream proteins, cell morphology, cell proliferation and apoptosis, and intracellular free Ca2+ levels were examined.ResultsWe verified that women with FSAD had higher miR-122-5p and lower VIPR1 protein. Then overexpressing miR-122-5p decreased relaxation of rat vaginal SMCs, which was manifested as a contractile morphology of cells, an increased intracellular free Ca2+ concentration, and lower cAMP concentration and PKA activity. Moreover, by rescue experiments, we inferred that VIPR1 was the target of miR-122-5p and affected the relaxation function of vaginal SMCs.ConclusionmiR-122-5p regulates the relaxation of vaginal SMCs in FSAD by targeting VIPR1, ulteriorly providing an underlying diagnostic and therapeutic target for FSAD.Cong S, Gui T, Shi Q, et al. Overexpressing miR-122-5p Inhibits the Relaxation of Vaginal Smooth Muscle in Female Sexual Arousal Disorder by Targeting Vasoactive Intestinal Peptide Receptor 1. Sex Med 2021;9:100390.

Synbiotic yogurt containing konjac mannan oligosaccharides and Bifidobacterium animalis ssp. lactis BB12 alleviates constipation in mice by modulating the stem cell factor (SCF)/c-Kit pathway and gut microbiota

Synbiotic dietary supplements, as an effective means of regulating the gut microbiota, may have a beneficial effect on constipation. This study evaluated the effects of synbiotic yogurt containing konjac mannan oligosaccharides (KMOS) and Bifidobacterium animalis ssp. lactis BB12 (BB12) on constipated Kunming mice (the model group). Following administration of yogurt containing 2.0% KMOS and BB12 (YBK2.0), black fecal weight and number and gastrointestinal transit rate increased by 97.5, 106.3, and 55.7%, respectively, compared with the model group. Serum levels of excitability neurotransmitters (motilin, substance P, and acetylcholine) in the YBK2.0 group were increased by 139.7, 120.4, and 91.8%, respectively, and serum levels of inhibitory neurotransmitters (vasoactive intestinal peptide, nitric oxide, and acetylcholine) were decreased. Moreover, synbiotic yogurt supplementation significantly downregulated the expression of vasoactive intestinal peptide receptor 1 (VIPR1) and upregulated the expression of serotonin receptor 4 (5-HT4) in the colon, and enhanced the expression of the stem cell factor (SCF)/c-Kit pathway. Additionally, YBK2.0 treatment significantly regulated the community composition and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of gut microbiota, which were positively correlated with physiological parameters of constipation. Thus, supplementation with synbiotic yogurt composed of KMOS and BB12 could facilitate fecal excretion by regulating related pathways and the gut microbiota. These findings demonstrated that the synbiotic yogurt can be considered a functional food for alleviating constipation.

Immune-associated molecular occurrence and prognosis predictor of hepatocellular carcinoma: an integrated analysis of GEO datasets

ABSTRACT Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second most common cause of cancer-related deaths worldwide. As immune response failure is the main factor in the occurrence and poor prognosis of HCC, our study aimed to develop an immune-associated molecular occurrence and prognosis predictor (IMOPP) of HCC. To that end, we discovered a 4-gene immune-associated gene signature: C–C motif chemokine ligand 14 (CCL14), kallikrein B1 (KLKB1), vasoactive intestinal peptide receptor 1 (VIPR1), and cluster of differentiation 4 (CD4). When tested on three cohorts as an immune-associated molecular occurrence predictor (IMOP), it had high sensitivity, specificity, and area under the receiver operating characteristics curve. When tested as an immune-associated molecular prognosis predictor (IMPP), it stratified the HCC prognosis for overall survival (Kaplan–Meier analysis, log rank P = 0.0016; Cox regression, HR = 1.832, 95% CI = 1.173–2.859, P = 0.008) and disease-free survival (Kaplan-Meier analysis, log rank P = 0.0227). IMPP also significantly correlated with the clinicopathological characteristics of HCC; integrating it with clinicopathological characteristics improved the accuracy of a nomogram for overall survival prediction (C-index: 0.7097 vs. 0.6631). In HCC tumor microenviroments, the proportion of CD8+ T cells significantly differed between IMOP-stratified groups. We conclude that IMOPP can potentially predict the occurrence of HCC in high-risk populations and improve prognostic accuracy by providing new biomarkers for risk stratification. In addition, we believe that the IMOP mechanism may be related to its effect on the proportion of CD8+ T cells in tumor-infiltrating lymphocytes.

Association of polymorphisms of vasoactive intestinal peptide and its receptor with reproductive traits of turkey hens

The aim of this study was to identify variations of vasoactive intestinal peptide (VIP) and VIP receptor-1 (VIPR-1) genes that might be associated with turkey reproductive traits. One hundred twenty turkey hens were recorded for age at first egg (AFE), first egg weight (FEW), egg number (EN), total egg weight (TEW), laying period (LP), and broodiness. The DNA was isolated from blood samples and subjected to PCR amplification of the meleagrine VIP and VIPR-1 genes. The SNPs were detected by single-strand conformation polymorphism and the variant DNA fragments were sequenced. One mutation in 3’-UTR of VIP (G5846A) and two SNPs in intron 2 of VIPR-1 (C17687T and A17690T) were found, all of them novel. The associations of the three detected SNPs with the reproductive traits of turkeys were evaluated. The detected polymorphisms were used for marker-trait association analyses. The results of association analysis showed that G5846A on 3’ UTR of VIP has a significant association with LP, EN, TEW, and AFE. The G allele of G5846A was the favourable SNP allele for LP, EN, and TEW traits. The AA genotype of A17690T on intron 2 of VIPR-1 was significantly associated with higher LP, EN, and TEW. AGAA haplotype showed association with higher EN and TEW. These results suggest that the SNPs in 3’-UTR of VIP and intron 2 of VIPR-1 genes may influence egg production traits in turkey hens.Keywords: broodiness, candidate gene, egg production, single nucleotide polymorphism, VIPR-1

Mechanism of VIPR1 gene regulating human lung adenocarcinoma H1299 cells.

The vasoactive intestinal peptide receptor-1(VIPR1) has prominent growth effects on a number of common neoplasms. However, there were contradictions in the effect cross different cancers. We aimed to explore the effect of VIPR1 overexpression on a human lung adenocarcinoma cell line H1299. GEO dataset was used to screen differentially expressed genes in lung adenocarcinoma tissues. The expression of VIPR1 mRNA was determined in the cancer Genome Atlas (TCGA). Immunohistochemical analysis was performed to determine VIPR1 protein expression in lung adenocarcinoma and corresponding adjacent tissues (n = 22). Fluorescence real-time quantitative PCR detected the expression of VIPR1 in human normal lung epithelial cell line BEAS-2B and lung adenocarcinoma cell line H1299. Overexpression strategies were employed to assess functions of VIPR1 expression on several malignant phenotypes in H1299. The expression of VIPR1 was lower in lung adenocarcinoma tissues than that in adjacent tissues. Compared with the normal lung epithelial cells BEAS-2B, VIPR1 was down-regulated in lung cancer cells H1299 (P < 0.05). After the overexpression of VIPR1, we found that VIPR1 significantly inhibited growth, migration, and invasion of H1299 cells (P < 0.05). Our findings point out the tumor suppressor roles of VIPR1 in human LUAD pathogenesis.

Promoter methylation and H3K27 deacetylation regulate the transcription of VIPR1 in hepatocellular carcinoma

Vasoactive intestinal peptide receptor 1 (VIPR1) is observed to express differently in human malignancies. Here, we aim to reveal clinical significance and transcriptional regulation mechanism of VIPR1 in hepatocellular carcinoma (HCC). Using immunohistochemistry, pyrosequencing, quantitative real-time PCR (qPCR), decitabine (DAC)/4-phenylbutyricacid (PBA) treatment and chromatin immunoprecipitation (ChIP), we found the low expression of VIPR1 was correlated with poor histological differentiation and poor survival. The promoter region of VIPR1 was methylated and DNA methylation inhibited VIPR1 gene transcription. Deacetylation of H3K27 in the promoter of VIPR1 inhibited the transcription of VIPR1 in HCC. In conclusion, low expression of VIPR1 had an adverse prognostic impact on HCC, and such expression is at least partially mediated by epigenetic modification.

Enteromorpha and polysaccharides from enteromorpha ameliorate loperamide-induced constipation in mice

Slow-transit constipation(STC)is a disease characterized by functional gastrointestinal disorder. Common laxatives used in clinical practice against constipation such as Senna have side effects. Enteromorpha(EP)is a common marine alga, and the polysaccharide extracted from EP has been reported possessing anti-cancer and anti-inflammation effects. The aim of this study is to investigate the effects of EP and Polysaccharides from Enteromorpha (PEP) on loperamide induced constipated mice model and illustrating mechanism of action. We investigated the effect of EP and PEP on fecal water content, defecation frequency and gastrointestinal transit (GI) time of loperamide-induced STC mice. In addition, serum Nitric Oxide (NO) content and vasoactive intestinal peptide receptor1 (VIPR1) as well as serotonin receptor (5-HT4) expression in the distal colon were analyzed. Furthermore, we determined the role of EP and PEP on microbiota distribution using stool genomic 16S rRNA sequencing. EP and PEP significantly enhanced intestinal motility function, and alleviated constipation associated intestinal inflammation. Moreover, EP and PEP significantly decreased serum NO concentration, down-regulated VIPR1 expression and up-regulated 5-HT4 expression in distal colon. Genomic stool DNA MiSeq Sequencing Analysis of microbiota community structures and distribution revealed that intestinal microecological changes caused by constipation recovered after both EP and PEP treatment. Our results indicate that EP and PEP are potent natural products which could be suggested in constipation therapy strategies.

Association of VIPR-1 gene polymorphisms and haplotypes with egg production in laying quails.

The laying quail is a worldwide breed which exhibits high economic value. In our current study, the vasoactive intestinal peptide receptor-1 (VIPR-1) was selected as the candidate gene for identifying traits of egg production. A single nucleotide polymorphism (SNP) detection was performed in 443 individual quails, including 196 quails from the H line, 202 quails from the L line, and 45 wild quails. The SNPs were genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Two mutations (G373T, A313G) were detected in all the tested quail populations. The associated analysis showed that the SNP genotypes of the VIPR-1 gene were significantly linked with the egg weight of G373T and A313G in 398 quails. The quails with the genotype GG always exhibited the largest egg weight for the two mutations in the H and L lines. Linkage disequilibrium (LD) analysis indicated that G373T and A313G loci showed the weakest LD. Seven main diplotypes from the four main reconstructed haplotypes were observed, indicating a significant association of diplotypes with egg weight. Quails with the h1h2 (GGGT) diplotype always exhibited the smallest egg weight and largest egg number at 20 weeks of age. The overall results suggest that the alterations in quails may be linked with potential major loci or genes affecting reproductive traits.

Effects of VIP on Corneal Reconstitution and Homeostasis followingPseudomonas aeruginosaInduced Keratitis

Studies from our laboratory have demonstrated that vasoactive intestinal peptide (VIP) directly converts the normally susceptible C57BL/6J (B6) mouse to resistant after ocular infection through modulation of the inflammatory response. This study examines mechanisms by which VIP influences the healing phase following infection--specifically reconstitution of the extracellular matrix (ECM). B6 mice received daily intraperitoneal (IP) injections of VIP, while control mice were similarly injected with sterile phosphate buffered saline (PBS). Real-time RT-PCR, ELISA, and immunofluorescent staining were used to assess the effects of VIP treatment on ECM molecule expression after Pseudomonas aeruginosa-induced keratitis. We also compared the effect of VIP treatment on lipopolysaccharide (LPS)-stimulated B6- and BALB/c-derived fibroblasts. In vivo analyses revealed that VIP treatment of P. aeruginosa-infected B6 corneas led to a significant increase in ECM molecules associated with healing/homeostasis, while those associated with ECM degradation were significantly down-regulated when compared to wild-type (WT) controls. In vitro studies revealed that VIP treatment of lipopolysaccharide-stimulated fibroblasts derived from susceptible B6 and resistant BALB/c mice expressed distinct differences in ECM molecule expression, whereby the latter expressed higher levels of ECM molecules aimed at reconstitution. Furthermore, differential expression of VIP receptor-1/VIP receptor-2 (VIPR1/VIPR2) was observed between B6 and BALB/c after VIP treatment of LPS-stimulated fibroblasts. VIP treatment functions to enhance ECM reconstitution, which appears to be carried out in large part by fibroblasts via VIPR2. Overall, the data from this study suggest that VIP not only regulates disease pathogenesis, but also functions to restore integrity of the corneal stroma.

Different sympathetic pathways control the metabolism of distinct bone envelopes

Bone remodeling, the mechanism that modulates bone mass adaptation, is controlled by the sympathetic nervous system through the catecholaminergic pathway. However, resorption in the mandible periosteum envelope is associated with cholinergic Vasoactive Intestinal Peptide (VIP)-positive nerve fibers sensitive to sympathetic neurotoxics, suggesting that different sympathetic pathways may control distinct bone envelopes. In this study, we assessed the role of distinct sympathetic pathways on rat femur and mandible envelopes. To this goal, adult male Wistar rats were chemically sympathectomized or treated with agonists/antagonists of the catecholaminergic and cholinergic pathways; femora and mandibles were sampled. Histomorphometric analysis showed that sympathectomy decreased the number of preosteoclasts and RANKL-expressing osteoblasts in mandible periosteum but had no effect on femur trabecular bone. In contrast, pharmacological stimulation or repression of the catecholaminergic cell receptors impacted the femur trabecular bone and mandible endosteal retromolar zone. VIP treatment of sympathectomized rats rescued the disturbances of the mandible periosteum and alveolar wall whereas the cholinergic pathway had no effect on the catecholaminergic-dependent envelopes. We also found that VIP receptor-1 was weakly expressed in periosteal osteoblasts in the mandible and was increased by VIP treatment, whereas osteoblasts of the retromolar envelope that was innervated only by tyrosine hydroxylase-immunoreactive fibers, constitutively expressed beta-2 adrenergic receptors. These data highlight the complexity of the sympathetic control of bone metabolism. Both the embryological origin of the bone (endochondral for the femur, membranous for the mandibular periosteum and the socket wall) and environmental factors specific to the innervated envelope may influence the phenotype of the sympathetic innervation. We suggest that an origin-dependent imprint of bone cells through osteoblast–nerve interactions determines the type of autonomous system innervating a particular bone envelope.

Identification and optimization of small molecule antagonists of vasoactive intestinal peptide receptor-1 (VIPR1)

Identification, synthesis and structure–activity relationship of small-molecule VIPR1 antagonists encompassing two chemical series are described.

Genetic characterization of Red Junglefowl (Gallus gallus), Thai indigenous chicken (Gallus domesticus), and two commercial lines using selective functional genes compared to microsatellite markers

Genetic characterization among Red Junglefowl (GS, Gallus gallus spadiceus), Thai indigenous chicken (TIC, Gallus domesticus) and commercial lines has been widely used for studies of genealogical origin, genetic diversity, and effects of selection. We compared the efficiency of genetic characterization of chicken populations that had been under different intensities of selection using selective functional gene versus microsatellite marker analyses. We genotyped 151 chickens from five populations: Red Junglefowl, TIC and commercial lines (BR, broiler and WL, White Leghorn). Genetic structure analyses using six loci of five functional genes - corresponding to heat tolerance (heat shock protein 70, HSP70/C, HSP70/M), broodiness (vasoactive intestinal peptide receptor-1, VIPR-1), egg production-[24-bp indel (insertion or deletion) prolactin, 24bpPRL], ovulation rate (growth hormone receptor, GHR), and growth (insulin-like growth factor-1, IGF-1) - were compared with 18 microsatellite markers. PCR-RFLP and allele specific PCR were used for functional gene typing. A neighbor-joining tree from Nei's genetic distance was constructed to show genetic relationships. A similar pattern was found with both functional genes and microsatellites. Three groups consisting of BR, WL and TIC-GS-GG were formed. A principal component plot based on individual similarity using Dice's coefficient was also constructed to confirm the relationship. Different patterns were found when using functional genes versus microsatellites. A principal component plot with functional genes also gave three clusters consisting of BR, WL and TIC-GS-GG. A principal component plot using microsatellites gave four clusters, consisting of WL, GG, TIC, and BR-GS. Characterization of BR and GS differs from previous studies. We concluded that genetic characterization with appropriate functional genes is more accurate when differences in genetic make-up among populations are known. Genetic characterization using functional gene data was consistent in neighbor joining and principal component plot analyses, while genetic characterization using microsatellite data gave varied results depending on the analysis methodology.

Characterization and use of a rabbit-anti-mouse VPAC1 antibody by flow cytometry

Vasoactive intestinal peptide receptor-1 signaling in lymphocytes has been shown to regulate chemotaxis, proliferation, apoptosis and differentiation. During T cell activation, VPAC1 mRNA is downregulated, but the effect on its protein levels is less clear. A small number of studies have reported measurement of human VPAC1 by flow cytometry, but murine VPAC1 reagents are unavailable. Therefore, we set out to generate a reliable and highly specific α-mouse VPAC1 polyclonal antibody for use with flow cytometry. After successfully generating a rabbit α-VPAC1 polyclonal antibody (α-mVPAC1 pAb), we characterized its cross-reactivity and showed that it does not recognize other family receptors (mouse VPAC2 and PAC1, and human VPAC1, VPAC2 and PAC1) by flow cytometry. Partial purification of the rabbit α-VPAC1 sera increased the specific-activity of the α-mVPAC1 pAb by 20-fold, and immunofluorescence microscopy (IF) confirmed a plasma membrane subcellular localization for mouse VPAC1 protein. To test the usefulness of this specific α-mVPAC1 pAb, we showed that primary, resting mouse T cells express detectable levels of VPAC1 protein, with little detectable signal from activated T cells, or CD19 B cells. These data support our previously published data showing a downregulation of VPAC1 mRNA during T cell activation. Collectively, we have established a well-characterized, and highly species specific α-mVPAC1 pAb for VPAC1 surface measurement by IF and flow cytometry.