Beneficial Effects of Remote Medical Care for Patients with Hereditary Hemorrhagic Telangiectasia during the COVID-19 Pandemic.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) needs high-quality care and multidisciplinary management. During the COVID-19 pandemic, most non-urgent clinical activities for HHT outpatients were suspended. We conducted an analytical observational cohort study to evaluate whether medical and psychological support, provided through remote consultation during the COVID-19 pandemic, could reduce the complications of HHT. METHODS: A structured regimen of remote consultations, conducted by either video-calls, telephone calls, or e-mails, was provided by a multidisciplinary group of physicians to a set of patients of our HHT center. The outcomes considered were: number of emergency room visits/hospitalizations, need of blood transfusions, need of iron supplementation, worsening of epistaxis, and psychological status. RESULTS: The study included 45 patients who received remote assistance for a total of eight months. During this period, 9 patients required emergency room visits, 6 needed blood transfusions, and 24 needed iron supplementation. This was not different from what was registered among the same 45 patients in the same period of the previous year. Remote care also resulted in better management of epistaxis and improved quality of life, with the mean epistaxis severity score and the Euro-Quality of Life-Visual Analogue Scale that were significantly better at the end than at the beginning of the study. DISCUSSION: Remote medical care might be a valid support for HHT subjects during periods of suspended outpatient surveillance, like the COVID-19 pandemic.

Fragment-Based Covalent Ligand Screening Enables Rapid Discovery of Inhibitors for the RBR E3 Ubiquitin Ligase HOIP.

Modification of proteins with polyubiquitin chains is a key regulatory mechanism to control cellular behavior and alterations in the ubiquitin system are linked to many diseases. Linear (M1-linked) polyubiquitin chains play pivotal roles in several cellular signaling pathways mediating immune and inflammatory responses and apoptotic cell death. These chains are formed by the linear ubiquitin chain assembly complex (LUBAC), a multiprotein E3 ligase that consists of 3 subunits, HOIP, HOIL-1L, and SHARPIN. Herein, we describe the discovery of inhibitors targeting the active site cysteine of the catalytic subunit HOIP using fragment-based covalent ligand screening. We report the synthesis of a diverse library of electrophilic fragments and demonstrate an integrated use of protein LC-MS, biochemical ubiquitination assays, chemical synthesis, and protein crystallography to enable the first structure-based development of covalent inhibitors for an RBR E3 ligase. Furthermore, using cell-based assays and chemoproteomics, we demonstrate that these compounds effectively penetrate mammalian cells to label and inhibit HOIP and NF-κB activation, making them suitable hits for the development of selective probes to study LUBAC biology. Our results illustrate the power of fragment-based covalent ligand screening to discover lead compounds for challenging targets, which holds promise to be a general approach for the development of cell-permeable inhibitors of thioester-forming E3 ubiquitin ligases.

A more detailed picture of the interactions between virtual screening-derived hits and the DNA G-quadruplex: NMR, molecular modelling and ITC studies.

The growing amount of literature about G-quadruplex DNA clearly demonstrates that such a structure is no longer viewed as just a biophysical strangeness but it is instead being considered as an important target for the treatment of various human disorders such as cancers or venous thrombosis. In this scenario, with the aim of finding brand new molecular scaffolds able to interact with the groove of the DNA quadruplex [d(TGGGGT)](4), we recently performed a successful structure-based virtual screening (VS) campaign. As a result, six molecules were found to be somehow groove binders. Herein, we report the results of novel NMR titration experiments of these VS-derived ligands with modified quadruplexes, namely [d(TGG(Br)GGT)](4) and [d(TGGGG(Br)T)](4). The novel NMR spectroscopy experiments combined with molecular modelling studies, allow for a more detailed picture of the interaction between each binder and the quadruplex DNA. Noteworthy, isothermal titration calorimetry (ITC) measurements on the above-mentioned compounds revealed that 2, 4, and 6 besides their relatively small dimensions bind the DNA quadruplex [d(TGGGGT)](4) with higher affinity than distamycin A, to the best of our knowledge, the most potent groove binder identified thus far.