Wilhelm Mosgoeller

Liposomal vasoactive intestinal peptide for lung application : Protection from proteolytic degradation

Inhalative administration of vasoactive intestinal peptide (VIP) is a promising approach for the treatment of severe lung diseases. However, the clinical use of VIP is limited by the fact that the peptide is prone to rapid degradation mechanisms and proteolytic digestion. Accordingly, VIP exhibits a very short period of activity in the lung. To overcome this problem, we have designed a liposomal drug delivery system for VIP and characterized it in terms of its potential to protect VIP from enzymatic cleavage. The proteolytic conditions of the lung, the target site of aerosolic administered VIP, were mimicked by bronchoalveolar lavage fluid (BALF), a lung surfactant solution, obtained by fiberoptic bronchoscopy. Thus, the stability of VIP was assessed by its resistance to enzymatic degradation in BALF, using a combination of high pressure liquid chromatography with mass spectrometry. We found that free VIP was rapidly digested, whereas liposomal-associated VIP remained intact. By fluorescence spectroscopic techniques using fluorescent-labelled VIP we got strong indications that the tight association of VIP with the lipid membrane is only minimally affected upon incubation with BALF. Loading capacity and stability of EtCy3-VIP loaded liposomes were measured by fluorescence fluctuation spectroscopy. Finally, the protective properties of the liposomes were also expressed in the maintained biological activity of the peptide incubated with BALF.

Involvement of endothelial NO in the dilator effect of VIP on rat isolated pulmonary artery

The endothelium and its interaction with smooth muscle play a central role in the local control of the pulmonary vasculature, and endothelial dysfunction is thought to contribute to pulmonary hypertension and chronic obstructive pulmonary disease. Vasoactive intestinal peptide (VIP), a 28-amino acid neuropeptide, relaxes the rat pulmonary artery, but there is controversy as to whether or not this action of VIP depends on the endothelium. The aim of this study, therefore, was to investigate the role of the endothelium and nitric oxide (NO), the major endothelium-derived relaxing factor, in the dilator action of VIP on the rat isolated pulmonary artery. Pulmonary artery preparations pre-contracted by the alpha(1)-adrenoceptor agonist L-phenylephrine were relaxed by VIP (0.003-1 microM) and acetylcholine (0.003-10 microM) in a concentration-dependent manner. Mechanical removal of the endothelium reduced the maximal response to VIP by about 50% and practically abolished the response to acetylcholine. Inhibition of NO synthesis by N(omega)-nitro-L-arginine methyl ester (0.5 mM) had a similar effect, abolishing the vasorelaxation caused by acetylcholine and attenuating the vasorelaxation caused by VIP by about 50%. From these data it is concluded that the relaxant action of VIP on the rat isolated pulmonary artery depends in part on the presence of the endothelium and that this part is mediated by endothelial NO.

VPAC receptor mediated tumor cell targeting by protamine based nanoparticles

The receptors for vasoactive intestinal peptide (VIP), VPAC1-, VPAC2-, and PAC1-receptor are overexpressed by various tumor cells. VIP can target these receptors and transport conjugates into the cell. However, the use of VIP for tumor cell targeting is hampered by the peptides short half-lives due to enzymatic degradation. Because protamine-based nanoparticles (proticles) protect the peptide and serve as peptide depot, we explored the potential of proticles as carrier for VIP-conjugated molecules. The VIP-loaded proticles were stable as shown by Fluorescence Correlation Spectroscopy. With Confocal Laser Scanning Microscopy, we observed VIP-loaded proticles to specifically target the tumor cells. The cell binding triggered the substance release and conjugate internalization of VIP-Cy3 in vitro and ex vivo by human tumors. We observed VIP releasing proticle depots distributed in rat tissue and human tumors. Our findings warrant further studies to explore the proticles potential to enable peptide-mediated targeting for in vivo and clinical applications.

Vasoactive intestinal peptide gene alterations in patients with idiopathic pulmonary arterial hypertension

Pulmonary arterial hypertension is a progressive disease, characterised by increased proliferation of pulmonary artery smooth muscle cells, vasoconstriction and remodelling of the vascular wall leading to right heart failure and death. The idiopathic form is rare (idiopathic arterial primary hypertension (IPAH); formerly PPH, MIM# 178600). Our group correlated a deficiency in vasoactive intestinal peptide (VIP; MIM# 192320) levels in serum and lung tissue with the pathogenesis of IPAH. The aim of this study was to investigate the relevance of genetic alterations in VIP to the development of IPAH. We screened 10 patients (age 4–66 years) for alterations in the coding, the noncoding regions and the enhancer region of the VIP gene by direct sequencing. In eight of 10 patients, we found alterations compared to the wild-type sequence. We detected nine alterations. In the noncoding regions, eight alterations were in the introns 1, 2, 3 and 4 (g.448G>A g.501C>T g.764T>C g.2267A>T g.2390C>T g.3144T>C g.3912A>G g.4857A>G). In the coding regions, a single alteration in the 3′ untranslated region in exon 7 (g.8129T>C) was observed in five patients. It appeared in 46% of the control group. The frequency of this alteration in the coding region of the VIP gene could therefore not be correlated with the appearance of IPAH. Apart from the importance of VIP signalling, genetic and/or environmental modifiers might therefore contribute to the development and perpetuation of the disease.

Vasoactive intestinal peptide (VIP) receptor expression in monocyte-derived macrophages from COPD patients.

Vasoactive intestinal peptide (VIP) is one of the most abundant molecules found in the respiratory tract. Due to its anti-inflammatory and bronchodilatatory properties, it has been proposed as a novel treatment for chronic obstructive pulmonary disease (COPD). The actions of VIP are mediated via three different G-protein-coupled receptors (VPAC1, VPAC2 and PAC1) which are expressed in the respiratory tract and on immunocompetent cells including macrophages. Alveolar macrophages (AM) are key players in the pathogenesis of COPD and contribute to the severity and progression of the disease. While VPAC1 has been reported to be elevated in subepithelial cells in smokers with chronic bronchitis, little is known about VPAC expression of AM in COPD patients. AM from COPD patients show a strong VPAC1 expression which exceeds VPAC2. A similar receptor expression pattern was also observed in lipopolysaccharide (LPS)-activated monocyte-derived macrophages (MDM) from healthy volunteers and COPD patients. VIP has been shown to down-regulate interleukin 8 (IL-8) secretion significantly in MDM after LPS stimulation. The response to VIP was similar in MDM from COPD patients and healthy volunteers. Our results indicate that VPAC1 up-regulation in macrophages is a common mechanism in response to acute and chronic pro-inflammatory stimuli. Although VPAC1 up-regulation is dominant, both receptor subtypes are necessary for optimal anti-inflammatory signaling. The high VPAC1 expression in AM may reflect the chronic pro-inflammatory environment found in the lung of COPD patients. Treatment with VIP may help to decrease the chronic inflammation in the lung of COPD patients.

The Vasoactive Intestinal Peptide Receptor Turnover in Pulmonary Arteries Indicates an Important Role for VIP in the Rat Lung Circulation

Abstract:  Vasoactive intestinal peptide (VIP) is a potent vasorelaxing peptide that plays a role in lung physiology and possibly in pulmonary hypertension. We investigated the turnover of the VIP receptors on rat pulmonary arteries ex vivo. There was evidence for a fast receptor turnover in pulmonary arteries, which underlines the important role of VIP for the regulation of pulmonary circulation and pulmonary pathology.

Mindfulness-based touch therapy and mindfulness practice in persons with moderate depression

The goal of the study was to explore the effects of mindfulness-based touch therapy, a passive body-therapy intervention, in combination with the practice of mindfulness as an active meditative discipline, in patients with moderate recurring or episodic depression. The method under study is seen as a possible adjunct to psychotherapy and psychopharmacotherapy. The degree of depression before and after the therapy phase was determined according to Hamiltons scale. The outcome was a highly significant improvement in depressive illness, with a general alleviation of depressed mood, reduction in feelings of guilt, in suicidal thoughts and in sleep maintenance insomnia; increase in motivation in carrying out everyday activities; reduction in feelings of anxiety at both psychological and somatic levels and easing of general somatic symptoms. The results show that the method under study can serve persons suffering from depression as an adjunct to conventional therapeutic measures.

Clinical Potential of VIP by Modified Pharmaco-kinetics and Delivery Mechanisms

Vasoactive intestinal peptide (VIP) conveys various physiological effects in the digestive tract, nervous and cardiovascular system, airways, reproductive system, endocrine system, and more. A family of specific membrane bound receptors, termed VPAC1, VPAC2, and PAC1, bind VIP and trigger the effects. Many of them are of clinical interest. To date more than two thousand publications suggest the use of VIP in diseases like asthma, erectile dysfunction, blood pressure regulation, inflammation, endocrinology, tumours, etc. Despite this considerable potential, the peptide is not regularly used in clinical settings. A key problem is the short half life of inhaled or systemically administered VIP due to rapid enzymatic degradation. This shortcomings could be overcome with stable derivates or improved pharmacokinetics. A promising strategy is to use biocompatible and degradable depots, to protect the peptide from early degradation and allow for controlled release. This review focuses on aspects of clinical applications of VIP and the idea to use formulations based on biodegradable particles, to constitute a dispersible VIP-depot. Smart particle systems protect the peptide from early degradation, and assist the sustainable cell targeting with VIP for therapeutic or imaging purposes.

New Nonradioactive Technique for Vasoactive Intestinal Peptide‐Receptor‐Ligand‐Binding Studies

Abstract:  We describe fluorescent‐labeled peptide (FLP) studies on living cells. The new technique is nonradioactive and it allows monitoring of the binding and internalization of Vasoactive Intestinal Peptide (VIP) in VIP receptor‐expressing cells. The technique is easy to perform and the observed reaction is peptide sequence specific.

Achtsame Massage und Achtsamkeitsschulung (Insightouch®) bei Depressionen, psychosomatischen und Bindungsstörungen

Hintergrund: Bindungsstörungen können das Auftreten von Angst und Depression begünstigen, lassen sich aber durch korrigierende emotionale Erfahrungen verändern. Eine Massage - insbesondere wenn beide, Masseur (m/w) und Klient, sich in einem Zustand der Achtsamkeit befinden - kann eine solche korrigierende Erfahrung vermitteln. In der vorliegenden Interventionsstudie wurden die Auswirkungen von Insightouch® - einer Kombination von achtsamkeitsbasierter Massage mit Achtsamkeitsschulung - untersucht. Teilnehmer und Methoden: Wir rekrutierten 36 Personen mit psychischen Beschwerden, geringer Bindungsfähigkeit und geringer Achtsamkeit. In Intervallen von 8 Wochen wurden mittels validierter Fragebögen Parameter wie psychosomatische Symptome (Brief Symptom Inventory), Bindungsqualitäten (Adult Attachment Scale) und Achtsamkeit (Freiburger Achtsamkeitsfragebogen) erhoben. Die Hälfte der Teilnehmer (Gruppe A) startete mit der 8-wöchigen Behandlungsphase; nach weiteren 8 Wochen ohne Behandlung wurde die Nachhaltigkeit der Behandlungswirkung dokumentiert. Die Teilnehmer der Gruppe B starteten mit einer 8-wöchigen Wartephase (Kontrollphase ohne Behandlung), gefolgt von der Behandlungsphase. Ergebnisse: Während sich nach der Kontrollphase keine signifikanten Änderungen zeigten, bewirkte die aktive Behandlung statistisch signifikante Besserungen der 1) Symptomatik, 2) Bindungsdefizite und 3) Achtsamkeit. Nach der 8-wöchigen Nachbeobachtungsphase waren die psychischen und die bindungsbezogenen Symptome weiter verbessert; die behandlungsbedingt erhöhte Fähigkeit zur Achtsamkeit blieb hoch. Schlussfolgerung: Insightouch als primär nonverbale Intervention erhöht die Bindungsfähigkeit, verbessert psychosomatische Symptome und erhöht nachhaltig die Fähigkeit zur Achtsamkeit.