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JLUpub ist das institutionelle Repositorium der Justus-Liebig-Universität.
JLUpub bietet Mitgliedern und Angehörigen der Universität die Möglichkeit neben wissenschaftlichen Dokumenten auch Forschungsdaten elektronisch zu veröffentlichen und dauerhaft zugänglich zu machen. Alle Veröffentlichungen erhalten einen Digital Object Identifier (DOI) und werden über nationale und internationale Bibliothekskataloge sowie Suchmaschinen nachgewiesen und auffindbar.
Neue Veröffentlichungen:
Molekulare, biochemische und klinische Untersuchungen zu Chronischer Prostatitis/Chronischem Beckenschmerzsyndrom in Hinblick auf Schmerz und Fertilität
(2024) Manthey, Marc Philipp
CP/CPPS stellt aufgrund der hohen Prävalenz eine Erkrankung mit enormer Bedeutung in der Urologie dar. Schmerzen und eine eingeschränkte Fertilität führen zu einem hohen Leidensdruck der Patienten. Trotz der hohen Prävalenz ist nur wenig über die Entstehung und Aufrechterhaltung der Symptomatik bekannt. Diese Tatsache verkompliziert das Stellen der Diagnose und die folgende Therapie ungemein. In den letzten Jahren rückte die neurogene Inflammation als Erklärungsmodell für CP/CPPS zunehmend in den Vordergrund. In dieser Arbeit wurden unterschiedliche Mediatoren aus dem Bereich der neurogenen Inflammation auf den drei Ebenen DNA, RNA und Protein untersucht. Die Studie gliedert sich in drei separate Abschnitte. Im ersten Teil führten wir Versuche an einer Gesamtkohorte von 267 Patienten und 151 Kontrollpersonen durch, um das heterogene Kollektiv von CP/CPPS-Patienten möglichst vollständig abzubilden. Anschließend bildeten wir hieraus im zweiten Teil der Studie eine Subkohorte mit Matching gegenüber dem Alter, um konfundierende Altersunterschiede zwischen den Kohorten auszuschließen. Im dritten Teil der Studie analysierten wir eine nach dem Faktor Schmerz selektionierte Subkohorte.
Wir untersuchten aus der Literatur vorbekannte Faktoren und solche, die im Kontext der Erkrankung vollkommen unerforscht waren. S100A12, RAGE, CALCA, CCL3, TNFα, TAC1R, NGF, PTGS2 und SLC6A4 fanden sich in CP/CPPS verändert und zeigten teils erhebliche Korrelationen mit dem Faktor Schmerz wie auch mit Markern der Fertilität. Besonders hervorzuheben sind S100A12 und der korrespondierende Rezeptor RAGE. S100A12 zeigte sich in CP/CPPS sowohl auf lokaler Ebene im Seminalplasma, als auch systemisch im Blut stark erhöht. Im Spermiogramm fanden sich erhebliche Korrelationen mit Markern der Inflammation, Fertilität und dem pH-Wert. Auch mit der klinischen Symptomatik fanden sich zahlreiche Korrelationen. Mit S100A12 schlagen wir einen potenziellen Biomarker vor, der mit Schmerz und Subfertilität in Zusammenhang zu stehen scheint. Hervorzuheben ist auch das Gen CALCA. Sowohl auf DNA- und RNA-Ebene zeigten sich in Patienten deutliche Veränderungen, die mit der Schmerz-symptomatik und Fertilitätsparametern korrelierten waren. Unsere Studie bietet eine solide Grundlage für weitere Studien zur Prüfung der Anwendbarkeit in Diagnostik und Therapie. Insbesondere CALCA und S100A12 scheinen hier vielversprechend zu sein.
Zusammengefasst lässt sich sagen, dass unsere Studie zahlreiche Veränderungen auf molekularer und biochemischer Ebene darstellen konnte, die sowohl mit der Schmerzsymptomatik und Subfertilität von CP/CPPS-Patienten in Verbindung gebracht werden können. Die Arbeit liefert tiefergehende Einblicke in die pathophysiologischen Prozesse von CP/CPPS und bietet eine solide Grundlage für weitere Untersuchungen.
Silyl Groups as Dispersion Energy Donors
(2024) König, Henrik Ferdinand
The introduction of silyl groups as protecting groups for alcohols has substantially changed synthetic organic chemistry. Although heavily utilized, some aspects of silyl groups, especially their potential to function as so called ‘dispersion energy donors’ in catalyst and functional material design remains mostly untapped, despite their generally greater polarizability and bulkiness in comparison to known carbon based dispersion energy donors.
In the first publication (section 2.1/2.2) of this work, we report an experimental and computational study on a rigid cyclooctatetraene molecular balance, a molecular system exhibiting a conformational equilibrium by means of which non covalent interactions can be quantified, substituted with common silyl protecting groups. We were able to quantify the relative steric demand of silyl groups and found conformational strain and Pauli exchange repulsion contributions to counteract significant stabilization from intramolecular London dispersion forces in the conformational equilibrium.
The second publication (section 2.3/2.4) addresses the London dispersion dominated attractive potential of bulky silyl groups by employing a similar cyclooctatetraene molecular balance. Strain build up was avoided by introducing rotatable spacers between the silyl groups and the balance scaffold. We found our experimental findings to be in line with our theoretical predictions on the potential of silyl groups to function as dispersion energy donors, despite entropy mitigating the net effect in this particular case.
In a third publication (section 2.5/2.6), we studied a cyclooctatetraene molecular balance featuring a spacer moiety and two hydroxy groups. We found the folded state of the balance to closely resemble the geometric arrangement of a cyclic water dimer transition state. By taking strain and solvation contributions into account, we were able to provide an estimate for the hydrogen bonding energy of the cyclic water dimer transition state, which proved to be in good agreement with high-level computational results. Furthermore, we were able to identify a significant contribution from London dispersion to the hydrogen bonding energy through computational energy decomposition analyses.
In the final chapter (section 2.7), we report the preparation of a set of phosphorescent platinum(II) phenylacetylide complexes substituted with bulky silyl groups, and their respective carbon counterparts. We studied their photophysical properties in solution and thin film, and thus were able to identify the ideal silyl group substitution pattern for application in a pure blue hyperfluorescent device. Our experimental findings agreed well with the computational conclusions. So we are able to interrogate the details of the calculations to understand the interplay of London dispersion controlled aggregation and the electronic effects of the silyl groups resulting in improvements in photophysical properties over the parent unsubstituted compound.
Concept study to develop a platform process for the production of antimicrobial peptides/proteins
(2023) Lappöhn, Carolin Anna
The increasing prevalence of antibiotic-resistant pathogens has created a demand for alternative treatments. However, the production of antimicrobial peptides and proteins (AMPs) in sufficient quantities for therapeutic use remains a significant bottleneck.
This study introduces an innovative platform technology for the heterologous production, purification, and detection of AMPs. The technology is based on a small fusion tag, called the C-tag, composed of four amino acids (EPEA) fused to the C terminus of AMPs. Notably, using a complex model AMP, we demonstrated for the first time that the C-tag enhances the expression of this AMP in Escherichia coli compared to the unmodified peptide. Further process intensification increased the yield by nearly 30-fold compared to previous attempts with the same AMP. The primary advantage of the tag is apparent during product purification, leading to > 85% recovery and ~80% purity in a single step without compromising product activity, thus eliminating the need to remove the tag in a cost-intensive additional process step.
In the subsequent parts of this study, we introduce, for the first time, an analytical immunoaffinity chromatography based on the C-tag. A detailed exploration of the critical process parameters using statistical optimization techniques enabled us to achieve 98.8 ± 0.1% analyte recovery. Validation of the method indicated high specificity, linearity, accuracy, and precision, underscored by a short sample analysis time, enabling high-throughput sample screening. Further characterization of the method revealed its limited ability to detect AMPs in acidic samples (pH < 2). Pretreatment strategies to overcome these limitations are discussed. Consequently, this study introduces a quantitative C-tag platform for the in-process monitoring of AMPs.
The Role of the Kinin System and the Effect of Des-Arginine9-Bradykinin on Coagulation and Platelet Function in Critically Ill COVID-19 Patients: A Secondary Analysis of a Prospective Observational Study
(2024) Edinger, Fabian; Edinger, Sophia; Schmidt, Götz; Koch, Christian; Sander, Michael; Schneck, Emmanuel
The effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the coagulation system is not fully understood. SARS-CoV-2 penetrates cells through angiotensin-converting enzyme 2 (ACE2) receptors, leading to its downregulation. Des-arginine9-bradykinin (DA9B) is degraded by ACE2 and causes vasodilation and increased vascular permeability. Furthermore, DA9B is associated with impaired platelet function. Therefore, the aim of this study was to evaluate the effects of DA9B on platelet function and coagulopathy in critically ill coronavirus disease 2019 (COVID-19) patients. In total, 29 polymerase-positive SARS-CoV-2 patients admitted to the intensive care unit of the University Hospital of Giessen and 29 healthy controls were included. Blood samples were taken, and platelet impedance aggregometry and rotational thromboelastometry were performed. Enzyme-linked immunosorbent assays measured the concentrations of DA9B, bradykinin, and angiotensin 2. Significantly increased concentrations of DA9B and angiotensin 2 were found in the COVID-19 patients. A negative effect of DA9B on platelet function and intrinsic coagulation was also found. A sub-analysis of moderate and severe acute respiratory distress syndrome patients revealed a negative association between DA9B and platelet counts and fibrinogen levels. DA9B provokes inhibitory effects on the intrinsic coagulation system in COVID-19 patients. This negative feedback seems reasonable as bradykinin, which is transformed to DA9B, is released after contact activation. Nevertheless, further studies are needed to confirm our findings.
A Novel Rat Model of Mild Pulmonary Hypertension Associated with Pulmonary Venous Congestion Induced by Left Pulmonary Vein Banding
(2024) Münks, Jonas; Yogeswaran, Athiththan; Antoine, Tobiah Kevin; Blumrich, Leonhard Anton; Dorfmüller, Peter; Ghofrani, Hossein Ardeschir; Assmus, Birgit; Schermuly, Ralph Theo; Sydykov, Akylbek
Pulmonary hypertension (PH) associated with left heart disease (PH-LHD) is the most common form of PH. In PH-LHD, changes in the pulmonary vasculature are assumed to be mainly caused by pulmonary venous congestion. However, the underlying mechanisms of this form of PH are poorly understood. We aimed to establish a model of PH associated with pulmonary venous congestion. Wistar–Kyoto rats underwent partial occlusion of the left pulmonary vein to induce pulmonary venous congestion or sham surgery and were assessed at various time points post-surgery (3, 6, 9, 12 weeks). In vivo cardiopulmonary phenotyping was performed by using echocardiography along with heart catheterization. Histomorphometry methods were used to assess pulmonary vascular remodeling (e.g., wall thickness, degree of muscularization). Left pulmonary vein banding (PVB) resulted in mildly elevated right ventricular systolic pressure and moderate right ventricular hypertrophy. In PVB rats, small- and medium-sized pulmonary vessels in the left lung were characterized by increased wall thickness and muscularization. Taken together, our data demonstrate that left PVB-induced pulmonary venous congestion is associated with pulmonary vascular remodeling and mild PH.