Dipyrromethane based receptors for anions

This thesis is principally concerned with the synthesis of a range of dipyrromethane based receptors and their ability to bind anions, in particular carboxylates of amino acid derivatives.Chapter I provides a general introduction to the field of Supramolecular Chemistry and its applications. In this chapter a series of receptors for anions are presented their properties discussed. A particular attention is given to the aromatic heterocycles based receptors and to enantioselective receptors.Chapter II describes the synthesis of a series of acyclic receptors which are the results of subsequent modifications of a simple tweezer, based on a dipyrromethane unit coupled with two butyl amines, previously studied by the group.1 The binding properties with a series of anions are presented and, for the chiral receptors, the binding properties with Nprotected amino acids were investigated.Chapter III describes the synthesis and the binding properties of a series of macrocycles obtained by modifications of the tweezer receptors. The binding properties of the macrocyclic receptors with a series of anions and amino acids are also presented

Modifying Rap1-signalling by targeting Pde6δ is neuroprotective in models of Alzheimer’s disease

Background: Neuronal Ca2+ dyshomeostasis and hyperactivity play a central role in Alzheimer's disease pathology arid progression. Amyloid-beta together with non-genetic risk-factors of Alzheimer's disease contributes to increased Ca2+ influx and aberrant neuronal activity, which accelerates neurodegeneration in a feed-forward fashion. As such, identifying new targets and drugs to modulate excessive Ca2+ signalling and neuronal hyperactivity, without overly suppressing them, has promising therapeutic potential. Methods: Here we show, using biochemical, electrophysiological, imaging, and behavioural tools, that pharmacological modulation of Rap1 signalling by inhibiting its interaction with Pde6 delta normalises disease associated Ca2+ aberrations and neuronal activity, conferring neuroprotection in models of Alzheimer's disease. Results: The newly identified inhibitors of the Rap1-Pde6 delta interaction counteract AD phenotypes, by reconfiguring Rapt signalling underlying synaptic efficacy, Ca2+ influx, and neuronal repolarisation, without adverse effects in-cellulo or invivo. Thus, modulation of Rap1 by Pde6 delta accommodates key mechanisms underlying neuronal activity, and therefore represents a promising new drug target for early or late intervention in neurodegenerative disorders. Conclusion: Targeting the Pde6 delta-Rap1 interaction has promising therapeutic potential for disorders characterised by neuronal hyperactivity, such as Alzheimer's disease

Clinical Features, Cardiovascular Risk Profile, and Therapeutic Trajectories of Patients with Type 2 Diabetes Candidate for Oral Semaglutide Therapy in the Italian Specialist Care

Introduction: This study aimed to address therapeutic inertia in the management of type 2 diabetes (T2D) by investigating the potential of early treatment with oral semaglutide. Methods: A cross-sectional survey was conducted between October 2021 and April 2022 among specialists treating individuals with T2D. A scientific committee designed a data collection form covering demographics, cardiovascular risk, glucose control metrics, ongoing therapies, and physician judgments on treatment appropriateness. Participants completed anonymous patient questionnaires reflecting routine clinical encounters. The preferred therapeutic regimen for each patient was also identified. Results: The analysis was conducted on 4449 patients initiating oral semaglutide. The population had a relatively short disease duration (42%  60% of patients, and more often than sitagliptin or empagliflozin. Conclusion: The study supports the potential of early implementation of oral semaglutide as a strategy to overcome therapeutic inertia and enhance T2D management

Synthesis and anion-binding properties of new disulfonamide-based receptors

The synthesis of disulfonamide receptor scaffolds for anion binding is reported. Acyclic receptors are found to tightly bind acetate in MeCN-d3 with dominant 1:1 stoichiometry, a smaller, sequential 1:2 (H+G) association is also found. Constraint of the disulfonamide receptor into macrocycles serves to eliminate the 1:2 binding stoichiometry and X-ray crystal structures of several macrocyclic receptors allow rationalisation of their affinity for acetate binding. l-Valine derived macrocycles maintain tight 1:1 binding of acetate (Ka1:1 &gt;104 M?1) in MeCN-d3 and display preference for oxyanion binding in more competitive MeCN-d3/2% H2O.<br/

Modifying Rap1-signalling by targeting Pde6δ is neuroprotective in models of Alzheimer's disease

BACKGROUND: Neuronal Ca2+ dyshomeostasis and hyperactivity play a central role in Alzheimer's disease pathology and progression. Amyloid-beta together with non-genetic risk-factors of Alzheimer's disease contributes to increased Ca2+ influx and aberrant neuronal activity, which accelerates neurodegeneration in a feed-forward fashion. As such, identifying new targets and drugs to modulate excessive Ca2+ signalling and neuronal hyperactivity, without overly suppressing them, has promising therapeutic potential. METHODS: Here we show, using biochemical, electrophysiological, imaging, and behavioural tools, that pharmacological modulation of Rap1 signalling by inhibiting its interaction with Pde6δ normalises disease associated Ca2+ aberrations and neuronal activity, conferring neuroprotection in models of Alzheimer's disease. RESULTS: The newly identified inhibitors of the Rap1-Pde6δ interaction counteract AD phenotypes, by reconfiguring Rap1 signalling underlying synaptic efficacy, Ca2+ influx, and neuronal repolarisation, without adverse effects in-cellulo or in-vivo. Thus, modulation of Rap1 by Pde6δ accommodates key mechanisms underlying neuronal activity, and therefore represents a promising new drug target for early or late intervention in neurodegenerative disorders. CONCLUSION: Targeting the Pde6δ-Rap1 interaction has promising therapeutic potential for disorders characterised by neuronal hyperactivity, such as Alzheimer's disease

Analysis of Outcomes in Ischemic vs Nonischemic Cardiomyopathy in Patients With Atrial Fibrillation A Report From the GARFIELD-AF Registry

IMPORTANCE Congestive heart failure (CHF) is commonly associated with nonvalvular atrial fibrillation (AF), and their combination may affect treatment strategies and outcomes