Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Conceptional Design of Self-Assembling Bisubstrate-like Inhibitors of Protein Kinase A Resulting in a Boronic Acid Glutamate Linkage

The spontaneous esterification of boronic acids with polyols provides a promising opportunity to generate self-assembled bisubstrate-like inhibitors within the binding pocket of cAMP-dependent protein kinase (PKA). As a first substrate component, we designed amino acids, which have either a boronic acid or ribopyranose side chain and introduced them to the substrate-like peptide protein kinase inhibitor (PKI). The second component was derived from the active-site inhibitor Fasudil, which was functionalized with phenylboronic acid. NMR spectroscopy in dimethylsulfoxide proved spontaneous reversible condensation of both components. Reinforced by the protein environment, both separately bound substrates were expected to react via boronic-ester formation bridging the two binding sites of PKA. Multiple crystal structures of PKA with bound PKIs, positionally modified with residues such as a ribopyranosylated serine and threonine or a phenylboronic acid attached to lysine via amide bonds, were determined with the phenylboronic acid-linked Fasudil. Although PKA accepts both inhibitors simultaneously, the expected covalent attachment between both components was not observed. Instead, spontaneous reaction of the terminal boronic acid group of the modified Fasudil with the carboxylate of Glu127 was detected once the latter residue is set free from a strong salt bridge formed with arginine by the original peptide inhibitor PKI. Thus, the desired self-assembly reaction occurs spontaneously in the protein environment by an unexpected carboxylic acid boronate complex. To succeed with our planned self-assembly reaction between both substrate components, we have to redesign the required reaction partners more carefully to finally yield the desired bisubstrate-like inhibitors in the protein environment

Advanced Molecular Tweezers with Lipid Anchors against SARS-CoV‑2 and Other Respiratory Viruses

The COVID-19 pandemic caused by SARS-CoV-2 presents a global health emergency. Therapeutic options against SARS-CoV-2 are still very limited but urgently required. Molecular tweezers are supramolecular agents that destabilize the envelope of viruses resulting in a loss of viral infectivity. Here, we show that first-generation tweezers, CLR01 and CLR05, disrupt the SARS-CoV-2 envelope and abrogate viral infectivity. To increase the antiviral activity, a series of 34 advanced molecular tweezers were synthesized by insertion of aliphatic or aromatic ester groups on the phosphate moieties of the parent molecule CLR01. A structure-activity relationship study enabled the identification of tweezers with a markedly enhanced ability to destroy lipid bilayers and to suppress SARS-CoV-2 infection. Selected tweezer derivatives retain activity in airway mucus and inactivate the SARS-CoV-2 wildtype and variants of concern as well as respiratory syncytial, influenza, and measles viruses. Moreover, inhibitory activity of advanced tweezers against respiratory syncytial virus and SARS-CoV-2 was confirmed in mice. Thus, potentiated tweezers are broad-spectrum antiviral agents with great prospects for clinical development to combat highly pathogenic viruses

Advanced Molecular Tweezers with Lipid Anchors against SARS-CoV‑2 and Other Respiratory Viruses

The COVID-19 pandemic caused by SARS-CoV-2 presents a global health emergency. Therapeutic options against SARS-CoV-2 are still very limited but urgently required. Molecular tweezers are supramolecular agents that destabilize the envelope of viruses resulting in a loss of viral infectivity. Here, we show that first-generation tweezers, CLR01 and CLR05, disrupt the SARS-CoV-2 envelope and abrogate viral infectivity. To increase the antiviral activity, a series of 34 advanced molecular tweezers were synthesized by insertion of aliphatic or aromatic ester groups on the phosphate moieties of the parent molecule CLR01. A structure-activity relationship study enabled the identification of tweezers with a markedly enhanced ability to destroy lipid bilayers and to suppress SARS-CoV-2 infection. Selected tweezer derivatives retain activity in airway mucus and inactivate the SARS-CoV-2 wildtype and variants of concern as well as respiratory syncytial, influenza, and measles viruses. Moreover, inhibitory activity of advanced tweezers against respiratory syncytial virus and SARS-CoV-2 was confirmed in mice. Thus, potentiated tweezers are broad-spectrum antiviral agents with great prospects for clinical development to combat highly pathogenic viruses