Mice lacking the VIP gene show airway hyperresponsiveness and airway inflammation, partially reversible by VIP

Division of Adult Psychiatry, University of California, Los Angeles, Los Ángeles, California, United States
AJP Lung Cellular and Molecular Physiology (Impact Factor: 4.08). 12/2006; 291(5):L880-6. DOI: 10.1152/ajplung.00499.2005
Source: PubMed


The mechanisms leading to asthma, and those guarding against it, are yet to be fully defined. The neuropeptide VIP is a cotransmitter, together with nitric oxide (NO), of airway relaxation, and a modulator of immune and inflammatory responses. NO-storing molecules in the lung were recently shown to modulate airway reactivity and were proposed to have a protective role against the disease. We report here that mice with targeted deletion of the VIP gene spontaneously exhibit airway hyperresponsiveness to the cholinergic agonist methacholine as well as peribronchiolar and perivascular cellular infiltrates and increased levels of inflammatory cytokines in bronchoalveolar lavage fluid. Immunologic sensitization and challenge with ovalbumin generally enhanced the airway hyperresponsiveness and airway inflammation in all mice. Intraperitoneal administration of VIP over a 2-wk period in knockout mice virtually eliminated the airway hyperresponsiveness and reduced the airway inflammation in previously sensitized and challenged mice. The findings suggest that 1) VIP may be an important component of endogenous anti-asthma mechanisms, 2) deficiency of the VIP gene may predispose to asthma pathogenesis, and 3) treatment with VIP or a suitable agonist may offer potentially effective replacement therapy for this disease.

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Available from: Anthony M Szema, May 12, 2014
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    • "First studies evaluating the endogenous role of VIP were performed in transgenic mice harboring a chimeric VIP gene which showed reduced brain VIP content and deficiencies in learning abilities supporting an important function for VIP in vivo [6]. Recently, it has been described that VIP-deficient mice display certain physiological abnormalities [7], [8] and exhibit reduced mortality and impaired proinflammatory responses to lipopolysaccharide-induced endotoxemia [9], suggesting that defects in the innate arm of immunity may occurs in the chronic absence of VIP. Numerous reports have focused on the effects of VIP treatment. "
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    ABSTRACT: Suitable biomarkers are essential for the design of therapeutic strategies in personalized medicine. Vasoactive intestinal peptide (VIP) has demonstrated immunomodulatory properties in autoimmune murine and ex vivo human models. Our aim was to study serum levels of VIP during the follow-up of an early arthritis (EA) cohort and to analyze its value as a biomarker predicting severity and therapeutic requirements. Data from 91 patients on an EA register were analyzed (76% rheumatoid arthritis (RA), 24% undifferentiated arthritis, 73% women, and median age 54 years; median disease duration at entry, 5.4 months). We collected per protocol sociodemographic, clinical, and therapeutic data. VIP levels were determined by enzyme immunoassay in sera harvested from the 91 patients (353 visits; 3.9 visit/patient) and from 100 healthy controls. VIP values below the 25(th) percentile of those assessed in healthy population were considered low. To determine the effect of independent variables on VIP levels, we performed a longitudinal multivariate analysis nested by patient and visit. A multivariate ordered logistic regression was modeled to determine the effect of low VIP serum levels on disease activity at the end of follow-up. VIP concentrations varied considerably across EA patients. Those fulfilling the criteria for RA had the lowest values in the whole sample, although no significant differences were observed compared with healthy donors. Disease activity, which was assessed using DAS28, inversely correlated with VIP levels. After a two-year follow-up, those patients with low baseline levels of VIP displayed higher disease activity and received more intensive treatment. Patients who are unable to up-regulate VIP seem to have a worse clinical course despite receiving more intense treatment. Therefore, measurement of VIP levels may be suitable as a prognostic biomarker.
    Full-text · Article · Jan 2014 · PLoS ONE
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    • "Of relevance, genetic deletion of VIP in mice causes not only characteristic hallmarks of chronic airway disease including airway hyperresponsiveness and peribronchial inflammation, but also moderate pulmonary arterial hypertension and considerable pulmonary vascular remodelling [47], [48]. Along these lines, VIP has been found to relax human pulmonary vascular smooth muscle cells [49], to reverse leukotriene D4-induced contraction in isolated pulmonary arteries [50], and to counteract the pulmonary vasoconstrictor response to U46619 in cats [51]. "
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    ABSTRACT: Stable analogs of vasoactive intestinal peptide (VIP) have been proposed as novel line of therapy in chronic obstructive pulmonary disease (COPD) based on their bronchodilatory and anti-inflammatory effects. We speculated that VIP analogs may provide additional benefits in that they exert vasodilatory properties in the lung, and tested this hypothesis in both ex vivo and in vivo models. In isolated perfused mouse lungs and in an in vivo rat model, pulmonary blood vessels were preconstricted by hypoxia and hemodynamic changes in response to systemic (ex vivo) or inhaled (in vivo) administration of the cyclic VIP analog RO 25-1553 were determined. In mouse lungs, RO 25-1553 reduced intrinsic vascular resistance at normoxia, and attenuated the increase in pulmonary artery pressure in response to acute hypoxia. Consistently, inhalation of RO 25-1553 (1 mg·mL(-1) for 3 min) caused an extensive and sustained (> 60 min) inhibition of the pulmonary arterial pressure increase in response to hypoxia in vivo that was comparable to the effects of inhaled sildenafil. This effect was not attributable to systemic cardiovascular effects of RO 25-1553, but to a lung specific reduction in pulmonary vascular resistance, while cardiac output and systemic arterial hemodynamics remained unaffected. No adverse effects of RO 25-1553 inhalation on pulmonary gas exchange, ventilation-perfusion matching, or lung fluid content were detected. Our findings demonstrate that inhaled delivery of the stable VIP analog RO 25-1553 induces a potent and sustained vasodilatory effect in the pulmonary circulation with no detectable adverse effects. Therapeutic inhalation of RO 25-1553 may provide vascular benefits in addition to its reported anti-inflammatory and bronchodilatory effects in COPD, yet caution is warranted given the overall poor results of vasodilator therapies for pulmonary hypertension secondary to COPD in a series of recent clinical trials.
    Full-text · Article · Sep 2013 · PLoS ONE
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    • "A larger variation in right ventricle dimensions compared to that of the left ventricle may result from the heterogeneity in expression of the asthma phenotype that is seen among the homozygous VIP knockout mice [7]. Asthma-like features and pulmonary hypertension co-exist in this strain [7]. "
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    ABSTRACT: Vasoactive Intestinal Peptide (VIP), a pulmonary vasodilator and inhibitor of vascular smooth muscle proliferation, is absent in pulmonary arteries of patients with idiopathic pulmonary arterial hypertension (PAH). We previously determined that targeted deletion of the VIP gene in mice leads to PAH with pulmonary vascular remodeling and right ventricular (RV) dilatation. Whether the left ventricle is also affected by VIP gene deletion is unknown. In the current study, we examined if VIP knockout mice (VIP(-/-)) develop both right (RV) and left ventricular (LV) cardiomyopathy, manifested by LV dilatation and systolic dysfunction, as well as overexpression of genes conducive to heart failure. We examined VIP(-/-)and wild type (WT) mice using Magnetic Resonance Imaging (MRI) for evidence of cardiomyopathy associated with biventricular dilation and wall thickness changes. Lung tissue from VIP(-/-) and WT mice was subjected to whole-genome gene microarray analysis. Lungs from VIP(-/-) mice showed overexpression of cardiomyopathy genes: Myh1 was upregulated 224 times over WT, and Mylpf was increased 72 fold. Tnnt3 was increased 105 times and tnnc2 181 fold. Hearts were dilated in VIP(-/-) mice, with thinning of LV wall and increase in RV and LV chamber size, though RV enlargement varied. Weights of VIP(-/-) mice were consistently lower. Critically-important heart failure-related genes are upregulated in VIP(-/-) mice associated with the spontaneous cardiomyopathy phenotype, involving both left and right ventricles, suggesting that loss of the VIP gene orchestrates a panoply of pathogenic genes which are detrimental to both left and right cardiac homeostasis.
    Full-text · Article · May 2013 · PLoS ONE
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