The human 7-transmembrane orphan receptor family MRGPRX: native expression and identification, development and pharmacological characterization of agonists and antagonists

The human MRGPRX receptors belong to the orphan 7-transmembrane receptors (7TMRs) within the Rhodopsin family of 7TMRs. The MRGPRX receptor subfamily is exclusively expressed in primates, which represents a hurdle for elucidating the (patho)physiological roles of these receptors. In this PhD thesis the four human MRGPRX receptors were pharmacologically investigated. The primary assay employed in this study was the β-arrestin assay using β-galactosidase complementation due to its high specificity for the expressed receptor. Additional assays including calcium mobilization and cAMP accumulation were also employed. MRGPRX1 is the best investigated member of the MRGPRX subfamily of 7TMRs. Our efforts were focused on screening several compound libraries in order to identify new antagonists for this receptor subtype. Only one compound, MIRA-1, was found to have an antagonistic activity at MRGPRX1 in the performed β-arrestin assays. However, the chemical structure (instable ester) and the steep concentration-response curve made us refrain from further investigation of this hit compound. Screening of further compound libraries should be performed in the future to identify ligands that are more suitable for drug development. MRGPRX2 was paired to the peptide agonist CST-14, but several other agonists have been described in the literature. However, no antagonists have been described so far. In our screening approach for antagonists using the β-arrestin assay several hits were identified, e.g. vitamin K3 (menadione) from a compound library. One hit from another compound library, designated CB8, with a tricyclic benzimidazole scaffold showed an IC50 value of 2.42 µM. It was decided to develop this hit further. Our efforts led to an establishment of structure-activity relationships (SARs) and to successive optimization of the parent compound. The best antagonist so far (CB63) exhibited an IC50 value of 6.38 nM. The mode of action of these antagonists was determined to be competitive versus CST-14. In addition, initial pharmacokinetic data of the best three antagonists were determined. Our results provide valuable tools for investigating the MRGPRX2 receptor. The MRGPRX3 receptor is an orphan receptor with no reported pharmacological tools for now. This receptor was cloned, and a β-arrestin cell line with high expression was established. Screening of all available compound libraries during the time of this thesis resulted in no hits. The MRGPRX3 receptor remains an enigmatic receptor. MRGPRX4 is an orphan receptor. The drug nateglinide was reported at the final stage of this thesis to act as a weak, non-selective agonist. Several screening and deorphanization approaches in the course of this thesis resulted in no progress until an artificial agonist was discovered. Related compounds were subsequently tested and initial SARs were established. Our efforts led to the optimization of both, efficacy and potency of the agonists. The best agonist with increased metabolic stability, showed EC50 values in the nanomolar range in both, β-arrestin and calcium mobilization assays. Using these agonists we demonstrated only Gq coupling for this 7TMR. Further synthesis resulted in an agonist which demonstrated increased efficacy with the best signal-to-noise ratio in the β-arrestin assay so far. For a deeper understanding of this receptor a search for a native cell line led us to stem cells differentiated to DRG-like neurons, and to the detection of MRGPRX4 in several lymphocyte subpopulations. The obtained information proved the expression and consequently a potential physiological role of MRGPRX4 in the immune system. Moreover, calcium mobilization assays showed a high signal with efficient Gq coupling. Screening for antagonists has also been carried out and several hits with different scaffolds have been identified. This opens up the door for the development of more potent and selective antagonists. All in all, the results of this thesis enrich our understanding of the so far not-well characterized MRGPRX receptor subfamily and provide important tools for future investigations

Synthesis and Design Strategies for the Development of Macroscopic Interplant Water Networks in Industrial Zones

Increased water scarcity problems, coupled with the immense scale of water-intensive industrial activities in the region demands for the development of optimal water reuse and recycling strategies in industrial cities. Hence, industrial water and wastewater management is a key research priority. As a result, several necessary aspects that have not been addressed previously in water integration methods have been considered in this work, by developing and implementing a framework which allows for improved applications of macroscopic water integration in complex industrial regions. The main components relevant to the planning of cost-effective water networks in a devised city plan have been captured with a focus on identifying cost-effective water allocations within an industrial city. Detailed information associated with water-using and water-consuming entities have been captured, using both flowrate and contamination information as well as site location information. Hence, a spatial representation that is capable of capturing an industrial city arrangement, has been developed to assist in water network design, an aspect which has often been overlooked in existing methods. Moreover, the presence of a number of different options during the selection process of appropriate treatment technologies, as well as the efficient placement of corresponding treatment facilities, have also been considered. In addition to the above aspects, two different pipeline merging representations that are capable of identifying cost-effective opportunities have also been captured in this work. Both approaches allow for the screening of less complex pipeline networks, by assembling together commonly existing pipe sections, in the course of determining optimal water networks. All methods were implemented and demonstrated using several industrial city layout scenarios, and each method was able to identify a number of optimal synergies

The Development of a Synthesis Approach for Optimal Design of Seawater Reverse Osmosis Desalination Networks

This work introduces a systematic seawater reverse osmosis (SWRO) membrane network synthesis approach, based on the coordinated use of process superstructure representations and global optimization. The approach makes use of superstructure formulations that are capable of extracting a globally optimal design as a performance target, by taking into consideration desired process conditions and constraints that are typically associated with reverse osmosis systems. Thermodynamic insights are employed to develop lean network representations so that any underperforming solutions can be eliminated a priori. This essentially results in considerable improvement of the overall search speed, compared to previously reported attempts. In addition, the approach enables the extraction of structurally different design alternatives. In doing so, distinct membrane network design classes were established by partitioning the search space, based on network size and connectivity. As a result, corresponding lean superstructures were then systematically generated, which capture all structural and operational variants within each design class. The overall purpose is thus to enable the extraction of multiple distinct optimal designs, through global optimization. This mainly helps provide design engineers with a better understanding of the design space and trade-offs between performance and complexity. The approach is illustrated by means of a numerical example, and the results obtained were compared to previously related work. As anticipated, the proposed approach consistently delivered the globally optimal solutions, as well as alternative efficient design candidates attributed to different design classes, with reduced CPU times. This work further capitalizes on the developed representation, by accounting for detailed water quality information, within the SWRO desalination network optimization problem. The superstructures were modified to incorporate models that capture the performance of common membrane elements, as predicted by commercially available simulator tools, e.g. ROSA (Dow) and IMSDesign (Hydranautics). These models allow tracing of individual components throughout the system. Design decisions that are supported by superstructure optimization include network size and connectivity, flow rates, pressures, and post treatment requirements. Moreover, a detailed economic assessment capturing all the significant capital and operating costs associated in SWRO processes, including intake, pre and post treatment has also been accounted for. These modifications were then illustrated using a case study involving four seawater qualities, with salinities ranging from 35 to 45 ppt. The results highlight the dependency of optimal designs on the feed water quality involved, as well as on specified permeate requirements

Fostering Giftedness and Creativity: Implementing Engineering by Design in Kuwait

The article offers information on a partnership between the International Technology & Engineering Educators Association (ITEEA) and the Sabah Al Ahmad Center for Giftedness and Creativity (SACGC) to support innovation and design education. The partnership is aimed towards the implementation of the Engineering byDesign (EbD) curriculum and contribute towards building a Kuwaiti society that fosters giftedness and creativity

The FKBP51 Inhibitor SAFit2 Restores the Pain-Relieving C16 Dihydroceramide after Nerve Injury

Neuropathic pain is a pathological pain state with a broad symptom scope that affects patients after nerve injuries, but it can also arise after infections or exposure to toxic substances. Current treatment possibilities are still limited because of the low efficacy and severe adverse effects of available therapeutics, highlighting an emerging need for novel analgesics and for a detailed understanding of the pathophysiological alterations in the onset and maintenance of neuropathic pain. Here, we show that the novel and highly specific FKBP51 inhibitor SAFit2 restores lipid signaling and metabolism in nervous tissue after nerve injury. More specifically, we identify that SAFit2 restores the levels of the C16 dihydroceramide, which significantly reduces the sensitization of the pain-mediating TRPV1 channel and subsequently the secretion of the pro-inflammatory neuropeptide CGRP in primary sensory neurons. Furthermore, we show that the C16 dihydroceramide is capable of reducing acute thermal hypersensitivity in a capsaicin mouse model. In conclusion, we report for the first time the C16 dihydroceramide as a novel and crucial lipid mediator in the context of neuropathic pain as it has analgesic properties, contributing to the pain-relieving properties of SAFit2

A succinate/SUCNR1-brush cell defense program in the tracheal epithelium

Host-derived succinate accumulates in the airways during bacterial infection. Here, we show that luminal succinate activates murine tracheal brush (tuft) cells through a signaling cascade involving the succinate receptor 1 (SUCNR1), phospholipase Cβ2, and the cation channel transient receptor potential channel subfamily M member 5 (TRPM5). Stimulated brush cells then trigger a long-range Ca2+ wave spreading radially over the tracheal epithelium through a sequential signaling process. First, brush cells release acetylcholine, which excites nearby cells via muscarinic acetylcholine receptors. From there, the Ca2+ wave propagates through gap junction signaling, reaching also distant ciliated and secretory cells. These effector cells translate activation into enhanced ciliary activity and Cl− secretion, which are synergistic in boosting mucociliary clearance, the major innate defense mechanism of the airways. Our data establish tracheal brush cells as a central hub in triggering a global epithelial defense program in response to a danger-associated metabolite

Step-by-step diagnosis and management of the nocebo/drucebo effect in statin-associated muscle symptoms patients: a position paper from the International Lipid Expert Panel (ILEP)

Statin intolerance is a clinical syndrome whereby adverse effects (AEs) associated with statin therapy [most commonly statin-associated muscle symptoms (SAMS)] result in the discontinuation of therapy and consequently increase the risk of adverse cardiovascular outcomes. However, complete statin intolerance occurs in only a small minority of treated patients (estimated prevalence of only 3-5%). Many perceived AEs are misattributed (e.g. physical musculoskeletal injury and inflammatory myopathies), and subjective symptoms occur as a result of the fact that patients expect them to do so when taking medicines (the nocebo/drucebo effect)-what might be truth even for over 50% of all patients with muscle weakness/pain. Clear guidance is necessary to enable the optimal management of plasma in real-world clinical practice in patients who experience subjective AEs. In this Position Paper of the International Lipid Expert Panel (ILEP), we present a step-by-step patient-centred approach to the identification and management of SAMS with a particular focus on strategies to prevent and manage the nocebo/drucebo effect and to improve long-term compliance with lipid-lowering therapy

Immediate and short-term effects of straw phonation in air or water on vocal fold vibration and supraglottic activity of adult patients with voice disorders visualized with strobovideolaryngoscopy : a pilot study

PURPOSE : The first purpose of this study was to investigate and compare the short-term effects after a semi-occluded vocal tract (SOVT) therapy session consisting of straw phonation (SP) in air or water on vocal fold vibration and supraglottic activity of adult patients with voice disorders, visualized with strobovideolaryngoscopy (SVL). The second purpose of this study was to investigate and compare immediate changes in the patients’ vocal fold vibration and supraglottic activity during SP in air or water, visualized with SVL. METHODS : Twelve adult patients with voice disorders (eight women and four men, mean age 52 years) were assigned randomly to one of two study groups: SP in air or SP in water. Immediately before and after a therapy session of 15 min, participants underwent a rigid SVL to determine the short-term effects of the SP session. At the posttherapy examination, flexible SVL while performing SP was added to determine the effects occurring during SP. The visual-perceptual ratings were performed blindly and in random order by three laryngologists, using the Voice-Vibratory Assessment with Laryngeal Imaging rating form for stroboscopy. RESULTS : Short-term effects after SP: After the SP-in-air session, the supraglottic mediolateral compression decreased significantly. The SP-in-water session led to significantly increased left vibrational amplitude. Immediate effects during SP: During SP in air, a significantly increased left amplitude and mucosal wave, and significantly decreased mediolateral supraglottic activity, were found. SP in water tended to decrease the vibrational amplitude during performance of the task. A trend toward higher anteroposterior supraglottic compression was observed during both SP in air and water, being more prominent in the latter. CONCLUSION : SP in air led to less false vocal fold adduction and consequently less hyperfunction. The small increment in anteroposterior supraglottic activity during SP in air and water might be related to epilarynx narrowing, an economic phenomenon associated with SOVT exercises. The effects on vibrational amplitude were rather ambiguous. The small reduction in amplitude during SP in water is expected to diminish vocal fold impact stress and therefore creates an ideal basis for voice therapy. The increment in amplitude and mucosal wave during SP in air might indicate insufficient supraglottic pressure to obtain the favorable effects of semi-occlusion. Whether or not the rise in amplitude after the SP-in-water session is due to voice efficiency or voice fatigue remains unknown. Future larger-scale investigation in subgroups of voice patients is needed to explore these hypotheses.http://www.journals.elsevier.com/journal-of-voicehj2023Speech-Language Pathology and Audiolog

Pooling and expanding registries of familial hypercholesterolaemia to assess gaps in care and improve disease management and outcomes : Rationale and design of the global EAS Familial Hypercholesterolaemia Studies Collaboration

Background: The potential for global collaborations to better inform public health policy regarding major non-hypercholesterolaemia (FH), a common genetic disorder associated with premature cardiovascular disease, is yet to be reliably ascertained using similar approaches. The European Atherosclerosis Society FH Studies Collaboration (EAS FHSC) is a new initiative of international stakeholders which will help establish a global FH registry to generate large-scale, robust data on the burden of FH worldwide. Methods: The EAS FHSC will maximise the potential exploitation of currently available and future FH data (retrospective and prospective) by bringing together regional/national/international data sources with access to individuals with a clinical and/or genetic diagnosis of heterozygous or homozygous FH. A novel bespoke electronic platform and FH Data Warehouse will be developed to allow secure data sharing, validation, cleaning, pooling, harmonisation and analysis irrespective of the source or format. Standard statistical procedures will allow us to investigate cross-sectional associations, patterns of real-world practice, trends over time, and analyse risk and outcomes (e.g. cardiovascular outcomes, all-cause death), accounting for potential confounders and subgroup effects. Conclusions: The EAS FHSC represents an excellent opportunity to integrate individual efforts across the world to tackle the global burden of FH. The information garnered from the registry will help reduce gaps in knowledge, inform best practices, assist in clinical trials design, support clinical guidelines and policies development, and ultimately improve the care of FH patients. (C) 2016 Elsevier Ireland Ltd.Peer reviewe

Efficacy and safety of bempedoic acid for the treatment of hypercholesterolemia: A systematic review and meta-analysis

Background Bempedoic acid is a first-in-class lipid-lowering drug recommended by guidelines for the treatment of hypercholesterolemia. Our objective was to estimate its average effect on plasma lipids in humans and its safety profile. Methods and findings We carried out a systematic review and meta-analysis of phase II and III randomized controlled trials on bempedoic acid (PROSPERO: CRD42019129687). PubMed (Medline), Scopus, Google Scholar, and Web of Science databases were searched, with no language restriction, from inception to 5 August 2019. We included 10 RCTs (n = 3,788) comprising 26 arms (active arm [n = 2,460]; control arm [n = 1,328]). Effect sizes for changes in lipids and high-sensitivity C-reactive protein (hsCRP) serum concentration were expressed as mean differences (MDs) and 95% confidence intervals (CIs). For safety analyses, odds ratios (ORs) and 95% CIs were calculated using the Mantel–Haenszel method. Bempedoic acid significantly reduced total cholesterol (MD −14.94%; 95% CI −17.31%, −12.57%; p < 0.001), non-high-density lipoprotein cholesterol (MD −18.17%; 95% CI −21.14%, −15.19%; p < 0.001), low-density lipoprotein cholesterol (MD −22.94%; 95% CI −26.63%, −19.25%; p < 0.001), low-density lipoprotein particle number (MD −20.67%; 95% CI −23.84%, −17.48%; p < 0.001), apolipoprotein B (MD −15.18%; 95% CI −17.41%, −12.95%; p < 0.001), high-density lipoprotein cholesterol (MD −5.83%; 95% CI −6.14%, −5.52%; p < 0.001), high-density lipoprotein particle number (MD −3.21%; 95% CI −6.40%, −0.02%; p = 0.049), and hsCRP (MD −27.03%; 95% CI −31.42%, −22.64%; p < 0.001). Bempedoic acid did not significantly modify triglyceride level (MD −1.51%; 95% CI −3.75%, 0.74%; p = 0.189), verylow-density lipoprotein particle number (MD 3.79%; 95% CI −9.81%, 17.39%; p = 0.585), and apolipoprotein A-1 (MD −1.83%; 95% CI −5.23%, 1.56%; p = 0.290). Treatment with bempedoic acid was positively associated with an increased risk of discontinuation of treatment (OR 1.37; 95% CI 1.06, 1.76; p = 0.015), elevated serum uric acid (OR 3.55; 95% CI 1.03, 12.27; p = 0.045), elevated liver enzymes (OR 4.28; 95% CI 1.34, 13.71; p = 0.014), and elevated creatine kinase (OR 3.79; 95% CI 1.06, 13.51; p = 0.04), though it was strongly associated with a decreased risk of new onset or worsening diabetes (OR 0.59; 95% CI 0.39, 0.90; p = 0.01). The main limitation of this meta-analysis is related to the relatively small number of individuals involved in the studies, which were often short or middle term in length. Conclusions Our results show that bempedoic acid has favorable effects on lipid profile and hsCRP levels and an acceptable safety profile. Further well-designed studies are needed to explore its longer-term safety