First in Class Dual Non-ATP-Competitive Glycogen Synthase Kinase 3ß/Histone Deacetylase Inhibitors as a Potential Therapeutic to Treat Alzheimer's Disease.

Despite recent FDA approvals, Alzheimer's disease (AD) still represents an unmet medical need. Among the different available therapeutic approaches, the development of multitarget molecules represents one of the most widely pursued. In this work, we present a second generation of dual ligands directed toward highly networked targets that are deeply involved in the development of the disease, namely, Histone Deacetylases (HDACs) and Glycogen Synthase Kinase 3ß (GSK-3ß). The synthesized compounds are highly potent GSK-3ß, HDAC2, and HDAC6 inhibitors with IC50 values in the nanomolar range of concentrations. Among them, compound 4 inhibits histone H3 and tubulin acetylation at 0.1 µM concentration, blocks hyperphosphorylation of tau protein, and shows interesting immunomodulatory and neuroprotective properties. These features, together with its ability to cross the blood-brain barrier and its favorable physical-chemical properties, make compound 4 a promising hit for the development of innovative disease-modifying agents.

PROTAC-Induced Glycogen Synthase Kinase 3ß Degradation as a Potential Therapeutic Strategy for Alzheimer's Disease.

Glycogen synthase kinase 3ß (GSK-3ß) is a serine/threonine kinase and an attractive therapeutic target for Alzheimer's disease. Based on proteolysis-targeting chimera (PROTAC) technology, a small set of novel GSK-3ß degraders was designed and synthesized by linking two different GSK-3ß inhibitors, SB-216763 and tideglusib, to pomalidomide, as E3 recruiting element, through linkers of different lengths. Compound 1 emerged as the most effective PROTAC being nontoxic up to 20 µM to neuronal cells and already able to degrade GSK-3ß starting from 0.5 µM in a dose-dependent manner. PROTAC 1 significantly reduced the neurotoxicity induced by Aß25-35 peptide and CuSO4 in SH-SY5Y cells in a dose-dependent manner. Based on its encouraging features, PROTAC 1 may serve as a starting point to develop new GSK-3ß degraders as potential therapeutic agents.

Structure-Based Optimization of 1,2,4-Triazole-3-Thione Derivatives: Improving Inhibition of NDM-/VIM-Type Metallo-ß-Lactamases and Synergistic Activity on Resistant Bacteria.

The worldwide emergence and dissemination of Gram-negative bacteria expressing metallo-ß-lactamases (MBLs) menace the efficacy of all ß-lactam antibiotics, including carbapenems, a last-line treatment usually restricted to severe pneumonia and urinary tract infections. Nonetheless, no MBL inhibitor is yet available in therapy. We previously identified a series of 1,2,4-triazole-3-thione derivatives acting as micromolar inhibitors of MBLs in vitro, but devoid of synergistic activity in microbiological assays. Here, via a multidisciplinary approach, including molecular modelling, synthesis, enzymology, microbiology, and X-ray crystallography, we optimized this series of compounds and identified low micromolar inhibitors active against clinically relevant MBLs (NDM-1- and VIM-type). The best inhibitors increased, to a certain extent, the susceptibility of NDM-1- and VIM-4-producing clinical isolates to meropenem. X-ray structures of three selected inhibitors in complex with NDM-1 elucidated molecular recognition at the base of potency improvement, confirmed in silico predicted orientation, and will guide further development steps.

Strigolactones as Broad-Spectrum Antivirals against ß-Coronaviruses through Targeting the Main Protease Mpro.

The current SARS-CoV-2 pandemic and the likelihood that new coronavirus strains will emerge in the immediate future point out the urgent need to identify new pan-coronavirus inhibitors. Strigolactones (SLs) are a class of plant hormones with multifaceted activities whose roles in plant-related fields have been extensively explored. Recently, we proved that SLs also exert antiviral activity toward herpesviruses, such as human cytomegalovirus (HCMV). Here we show that the synthetic SLs TH-EGO and EDOT-EGO impair ß-coronavirus replication including SARS-CoV-2 and the common cold human coronavirus HCoV-OC43. Interestingly, in silico simulations suggest the binding of SLs in the SARS-CoV-2 main protease (Mpro) active site, and this was further confirmed by an in vitro activity assay. Overall, our results highlight the potential efficacy of SLs as broad-spectrum antivirals against ß-coronaviruses, which may provide the rationale for repurposing this class of hormones for the treatment of COVID-19 patients.

Lack of interaction of the fluorosurfactant C6O4 with human renal transporters: In vitro/in silico analysis.

C6O4 is a water soluble perfluoroether carboxylic acid ammonium salt used as surfactant in the synthesis of fluoropolymers. Available experimental data in rats exposed by the oral route indicate it is eliminated in urine. Previous studies with various linear perfluorocarboxylic acids have suggested that these compounds are substrates of renal membrane transporters in rats and humans, and that the interaction with basal and apical membrane transporters can influence the elimination kinetic by these organisms and explain, in part, the observed differences in the respective half-lives. In particular, apical transporters may contribute to the reuptake of these exogenous compounds from the tubule lumen. The present study was designed to investigate the uptake of C6O4 in two renal cell lines transiently transfected with the human apical membrane transporters, organic anion transporter 4 (OAT4), and urate transporter 1 (URAT1). The uptake of the linear perfluorohexanoic acid (PFC6) was evaluated in parallel. While the uptake of the conjugated steroid estrone-3-sulfate (E3S), a known substrate for renal transporters, and of PFC6 was clearly observed in both cell types transfected with either OAT4 or URAT1, no significant uptake of C6O4 was measured under the same test conditions. The results of the transporter's functionality measured in vitro were consistent with molecular docking simulations. Both outward and inward models of the transporters showed a reduced interaction between C6O4 and URAT1 or OAT4. In contrast, more stable interactions were predicted for PFC6 and PFOA, as well as for the E3S substrate, as shown by the respective docking scores reflecting the binding strength and by the poses assumed in the transporter channels. Altogether, the in vitro and in silico modeling results showed a low reuptake potential and limited interactions of C6O4 molecule with two human apical membrane transporters, contrasting with the more efficient reuptake of PFC6 from the tubule lumen. These results suggest reabsorption from the proximal tubule by apical renal transporters is not likely to interfere with the elimination pathway of C6O4 in humans.