Soluble ectodomain of neuroligin 1 decreases synaptic activity by activating metabotropic glutamate receptor 2

Synaptic cell adhesion molecules represent important targets for neuronal activity-dependent proteolysis. Postsynaptic neuroligins (NLs) form trans-synaptic complexes with presynaptic neurexins (NXs). Both NXs and NLs are cleaved from the cell surface by metalloproteases in an activity-dependent manner, releasing a soluble extracellular fragment and membrane-tethered C-terminal fragment. The cleavage of NL1 depresses synaptic transmission, but the mechanism by which this occurs is unknown. Metabotropic glutamate receptor 2 (mGluR2) are located primarily at the periphery of presynaptic terminals, where they inhibit the formation of cyclic adenosine monophosphate (cAMP) and consequently suppress the release of glutamate and decrease synaptic transmission. In the present study, we found that the soluble ectodomain of NL1 binds to and activates mGluR2 in both neurons and heterologous cells, resulting in a decrease in cAMP formation. In a slice preparation from the hippocampus of mice, NL1 inhibited the release of glutamate from mossy fibers that project to CA3 pyramidal neurons. The presynaptic effect of NL1 was abolished in the presence of a selective antagonist for mGluR2. Thus, our data suggest that the soluble extracellular domain of NL1 functionally interacts with mGluR2 and thereby decreases synaptic strength

pTEVAR of an aorto-esophageal fistula in esophageal cancer: Case report and review of the literature

An aorto-esophageal fistula (AEF) is a rare and life-threatening situation, associated with aneurysms, foreign bodies, infiltrating tumors, and radiotherapy. The ideal management is unclear. Open surgery of AEF has a high mortality and morbidity. Thoracic endovascular aortic repair (TEVAR) of an AEF is an effective and safe emergency treatment for these patients. We describe a case of AEF due to esophageal cancer successfully treated the first time by total percutaneous TEVAR (pTEVAR). A 70-year-old male patient presented with massive hematemesis at the emergency department. The patient had a known history of esophageal cancer previously treated by radiochemotherapy which was completed 3 days before. Emergency upper gastrointestinal endoscopy failed to stop the bleeding. Subsequent contrast-enhanced computed tomography revealed an aorto-esophageal fistula and emergency pTEVAR was performed. The bleeding stopped directly after stent graft placement and the patient was discharged after 10 days later. He died 3 months after pTEVAR from cancer progression. pTEVAR is an effective and safe treatment option for AEF. It can be applied as a first-line treatment and offers the potential to improve survival in the emergency setting

Modular Platform for the Development of Recombinant Hemoglobin Scavenger Biotherapeutics

Cell-free hemoglobin (Hb) is a driver of disease progression in conditions with intravascular or localized hemolysis. Genetic and acquired anemias or emergency medical conditions such as aneurysmal subarachnoid hemorrhage involve tissue Hb exposure. Haptoglobin (Hp) captures Hb in an irreversible protein complex and prevents its pathophysiological contributions to vascular nitric oxide depletion and tissue oxidation. Preclinical proof-of-concept studies suggest that human plasma-derived Hp is a promising therapeutic candidate for several Hb-driven diseases. Optimizing the efficacy and safety of Hb-targeting biotherapeutics may require structural and functional modifications for specific indications. Improved Hp variants could be designed to achieve the desired tissue distribution, metabolism, and elimination to target hemolytic disease states effectively. However, it is critical to ensure that these modifications maintain the function of Hp. Using transient mammalian gene expression of Hp combined with co-transfection of the pro-haptoglobin processing protease C1r-LP, we established a platform for generating recombinant Hp-variants. We designed an Hpβ-scaffold, which was expressed in this system at high levels as a monomeric unit (mini-Hp) while maintaining the key protective functions of Hp. We then used this Hpβ-scaffold as the basis to develop an initial proof-of-concept Hp fusion protein using human serum albumin as the fusion partner. Next, a hemopexin-Hp fusion protein with bispecific heme and Hb detoxification capacity was generated. Further, we developed a Hb scavenger devoid of CD163 scavenger receptor binding. The functions of these proteins were then characterized for Hb and heme-binding, binding of the Hp–Hb complexes with the clearance receptor CD163, antioxidant properties, and vascular nitric oxide sparing capacity. Our platform is designed to support the generation of innovative Hb scavenger biotherapeutics with novel modes of action and potentially improved formulation characteristics, function, and pharmacokinetics

Identification of Brain-Specific Treatment Effects in NPC1 Disease by Focusing on Cellular and Molecular Changes of Sphingosine-1-Phosphate Metabolism

Niemann–Pick type C1 (NPC1) is a lysosomal storage disorder, inherited as an autosomal-recessive trait. Mutations in the Npc1 gene result in malfunction of the NPC1 protein, leading to an accumulation of unesterified cholesterol and glycosphingolipids. Beside visceral symptoms like hepatosplenomegaly, severe neurological symptoms such as ataxia occur. Here, we analyzed the sphingosine-1-phosphate (S1P)/S1P receptor (S1PR) axis in different brain regions of Npc1−/− mice and evaluated specific effects of treatment with 2-hydroxypropyl-β-cyclodextrin (HPβCD) together with the iminosugar miglustat. Using high-performance thin-layer chromatography (HPTLC), mass spectrometry, quantitative real-time PCR (qRT-PCR) and western blot analyses, we Int. J. Mol. Sci. 2020, 21, 4502; doi:10.3390/ijms21124502 www.mdpi.com/journal/ijms Int. J. Mol. Sci. 2020, 21, 4502 2 of 31 studied lipid metabolism in an NPC1 mouse model and human skin fibroblasts. Lipid analyses showed disrupted S1P metabolism in Npc1−/− mice in all brain regions, together with distinct changes in S1pr3/S1PR3 and S1pr5/S1PR5 expression. Brains of Npc1−/− mice showed only weak treatment effects. However, side effects of the treatment were observed in Npc1+/+ mice. The S1P/S1PR axis seems to be involved in NPC1 pathology, showing only weak treatment effects in mouse brain. S1pr expression appears to be affected in human fibroblasts, induced pluripotent stem cells (iPSCs)-derived neural progenitor and neuronal differentiated cells. Nevertheless, treatment-induced side effects make examination of further treatment strategies indispensabl

Photoaging smartphone app promoting poster campaign to reduce smoking prevalence in secondary schools: the Smokerface Randomized Trial: design and baseline characteristics

Introduction: Smoking is the largest cause of preventable death globally. Most smokers smoke their first cigarette in early adolescence. We took advantage of the widespread availability of mobile phones and adolescents’ interest in appearance to develop a free photoaging app which is promoted via a poster campaign in secondary schools. This study aims to evaluate its effectiveness regarding smoking prevalence and students’ attitudes towards smoking. Methods and analysis A randomised controlled trial is conducted with 9851 students of both genders with an average age of 12 years in grades 6 and 7 of 126 secondary schools in Germany. At present, cigarette smoking prevalence in our sample is 4.7%, with 4.6% of the students currently using e-cigarettes (1.6% use both). The prospective experimental study design includes measurements at baseline and at 6, 12 and 24 months postintervention via a questionnaire plus a random cotinine saliva sample at 24 months postintervention. The study groups consist of randomised schools receiving the Smokerface poster campaign and control schools with comparable baseline data (no intervention). The primary end point is the difference of change in smoking prevalence in the intervention group versus the difference in the control group at 24 months follow-up. Longitudinal changes in smoking-related attitudes, the number of new smokers and quitters and the change in the number of never-smokers will be compared between the two groups as secondary outcomes. Ethics and dissemination Ethical approval was obtained from the ethics committee of the University of Gießen and the ministries of cultural affairs, both in Germany. Results will be disseminated at conferences, in peer-reviewed journals, on our websites and throughout the multinational Education Against Tobacco network. Trial registration number NCT02544360, Pre-results