Safe, effective, and low-cost oral antiviral therapies are needed to treat those at high risk for developing severe COVID-19. To that end, we performed a high-throughput screen to identify non-peptidic, non-covalent inhibitors of the SARS-CoV-2 main protease (Mpro), an essential enzyme in viral replication. NZ-804 was developed from a screening hit through iterative rounds of structure-guided medicinal chemistry.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2024
We present the inaugural synthesis of a chiral teropyrene achieved through a four-fold alkyne benzannulation catalyzed by InCl, resulting in good yields. The product underwent thorough characterization using FT-Raman and FT-IR spectroscopies, demonstrating a close agreement with calculated spectra. X-ray crystallographic analysis unveiled a notable twist in the molecule's backbone, with an end-to-end twist angle of 51°, consistent with computational predictions.
View Article and Find Full Text PDFCellular sensitivity to ferroptosis is primarily regulated by mechanisms mediating lipid hydroperoxide detoxification. We show that inositol-requiring enzyme 1 (IRE1α), an endoplasmic reticulum (ER) resident protein critical for the unfolded protein response (UPR), also determines cellular sensitivity to ferroptosis. Cancer and normal cells depleted of IRE1α gain resistance to ferroptosis, while enhanced IRE1α expression promotes sensitivity to ferroptosis.
View Article and Find Full Text PDFBackground: A growing interest in long-term sequelae of COVID-19 has prompted several systematic literature reviews (SLRs) to evaluate long-COVID-19 effects. However, many of these reviews lack in-depth information on the timing, duration, and severity of these conditions.
Objectives: Our aim was to synthesize both qualitative and quantitative evidence on prevalence and outcomes of long-term effect of COVID-19 through an umbrella review.
The main aim of this study is to synthesize contrast microbubbles (MB) functionalized with engineered protein ligands using a microfluidic device to target breast cancer specific vascular B7-H3 receptor in vivo for diagnostic ultrasound imaging. We used a high-affinity affibody (ABY) selected against human/mouse B7-H3 receptor for engineering targeted MBs (TMBs). We introduced a C-terminal cysteine residue to this ABY ligand for facilitating site-specific conjugation to DSPE-PEG-2K-maleimide (M.
View Article and Find Full Text PDFOwing to condensed development processes, expanding evidence and differences in healthcare system characteristics, many COVID-19 guidelines differ in their quality and treatment recommendations, which has consequences for clinical practice. This review aimed to identify COVID-19 treatment guidelines, assess their quality and summarise their recommendations. Guidelines were identified for five therapies most commonly used among inpatients with COVID-19 (remdesivir, dexamethasone, tocilizumab, baricitinib and casirivimab/imdevimab) from 11 countries.
View Article and Find Full Text PDFExperimental studies exploring the effects of intranasal oxytocin are typically underpowered due to small samples. Open access to experimental data and procedures and the use of previously employed measures is critical to building more robust and replicable findings, especially in less studied areas of oxytocin research. In this paper, data is provided from a double-blind placebo-controlled crossover study exploring the effects of intranasal oxytocin (IN-OT: 24 IU) on social preference to romantic partners, parents, peers, and strangers.
View Article and Find Full Text PDFMolecular imaging using singlechain variable fragments (scFv) of antibodies targeting cancer specific antigens have been considered a non-immunogenic approach for early diagnosis in the clinic. Usually, production of proteins is performed within Escherichia coli. Recombinant proteins are either expressed in E.
View Article and Find Full Text PDFDehydrohalogenation, or elimination of hydrogen-halide equivalents, remains one of the simplest methods for the installation of the biologically-important olefin functionality. However, this transformation often requires harsh, strongly-basic conditions, rare noble metals, or both, limiting its applicability in the synthesis of complex molecules. Nature has pursued a complementary approach in the novel vitamin B-dependent photoreceptor CarH, where photolysis of a cobalt-carbon bond leads to selective olefin formation under mild, physiologically-relevant conditions.
View Article and Find Full Text PDFPancreatic ductal adenocarcinoma (PDAC) is often associated with a poor prognosis due to silent onset, resistance to therapies, and rapid spreading. Most patients are ineligible for curable surgery as they present with advanced disease at the time of diagnosis. Present diagnostic methods relying on anatomical changes have various limitations including difficulty to discriminate between benign and malignant conditions, invasiveness, the ambiguity of imaging results, or the inability to detect molecular biomarkers of PDAC initiation and progression.
View Article and Find Full Text PDFOral antiretroviral agents provide life-saving treatments for millions of people living with HIV, and can prevent new infections via pre-exposure prophylaxis. However, some people living with HIV who are heavily treatment-experienced have limited or no treatment options, owing to multidrug resistance. In addition, suboptimal adherence to oral daily regimens can negatively affect the outcome of treatment-which contributes to virologic failure, resistance generation and viral transmission-as well as of pre-exposure prophylaxis, leading to new infections.
View Article and Find Full Text PDFUnlabelled: Early detection of pancreatic ductal adenocarcinoma (PDAC) represents the most significant step toward the treatment of this aggressive lethal disease. Previously, we engineered a preclinical Thy1-targeted microbubble (MBThy1) contrast agent that specifically recognizes Thy1 antigen overexpressed in the vasculature of murine PDAC tissues by ultrasound (US) imaging. In this study, we adopted a single-chain variable fragment (scFv) site-specific bioconjugation approach to construct clinically translatable MBThy1-scFv and test for its efficacy in vivo in murine PDAC imaging, and functionally evaluated the binding specificity of scFv ligand to human Thy1 in patient PDAC tissues ex vivo.
View Article and Find Full Text PDFUltrasound molecular imaging (UMI) is enabled by targeted microbubbles (MBs), which are highly reflective ultrasound contrast agents that bind to specific biomarkers. Distinguishing between adherent MBs and background signals can be challenging in vivo. The preferred preclinical technique is differential targeted enhancement (DTE), wherein a strong acoustic pulse is used to destroy MBs to verify their locations.
View Article and Find Full Text PDFPurpose: Human B7-H3 (hB7-H3) is a promising molecular imaging target differentially expressed on the neovasculature of breast cancer and has been validated for preclinical ultrasound (US) imaging with anti-B7-H3-antibody-functionalized microbubbles (MB). However, smaller ligands such as affibodies (ABY) are more suitable for the design of clinical-grade targeted MB.
Experimental Design: Binding of ABY was confirmed with soluble and cell-surface B7-H3 by flow cytometry.
The synthesis of pyreno[]pyrene-based helicene hybrids was achieved in good yield via a four-fold alkyne benzannulation reaction that was promoted by Brønsted acid. The molecules are configurationally locked, allowing the enantiomers to be separated using chiral HPLC so that their photophysical and chiroptical properties, including circular dichroism and circularly polarized luminescence, could be studied.
View Article and Find Full Text PDFFront Cell Dev Biol
August 2019
The YAP1/Hippo and p53 pathways are critical protectors of genome integrity in response to DNA damage. Together, these pathways secure cellular adaptation and maintain overall tissue integrity through transcriptional re-programing downstream of various environmental and biological cues generated during normal tissue growth, cell proliferation, and apoptosis. Genetic perturbations in YAP1/Hippo and p53 pathways are known to contribute to the cells' ability to turn rogue and initiate tumorigenesis.
View Article and Find Full Text PDFSpectroscopic photoacoustic (sPA) molecular imaging has high potential for identification of exogenous contrast agents targeted to specific markers. Antibody-dye conjugates have recently been used extensively for preclinical sPA and other optical imaging modalities for highly specific molecular imaging of breast cancer. However, antibody-based agents suffer from long circulation times that limit image specificity.
View Article and Find Full Text PDFThe properties of nanographenes can be tuned by changing their shapes, therefore the development of new methods suitable for the synthesis of various nanographenes is highly desirable. Described herein is an intramolecular InCl /AgNTf -catalyzed regioselective domino benzannulation reaction of buta-1,3-diynes to build irregular nanographenes. Different nanographene compounds were easily obtained in moderate to high yields through careful design of the precursor compounds.
View Article and Find Full Text PDFA highly regioselective synthesis of 2,3-disubstituted chromen-4-one derivatives is accomplished from readily available internal alkynes and 2-methoxybenzoyl chlorides. The reaction proceeds via a domino intermolecular Friedel-Crafts acylation/intramolecular vinyl carbocation trapping (or oxa-Michael addition)/demethylation reaction sequence. This Lewis acid promoted method features relatively mild reaction conditions to synthesize a variety of 2,3-disubstituted chromen-4-one derivatives in one pot with up to 93% yield.
View Article and Find Full Text PDFWound healing is characterized by the production of large amounts of protein necessary to replace lost cellular mass and extracellular matrix. The unfolded protein response (UPR) is an important adaptive cellular response to increased protein synthesis. One of the main components of the UPR is IRE1, an endoplasmic reticulum transmembrane protein with endonuclease activity that produces the activated form of the transcription factor XBP1.
View Article and Find Full Text PDFAntimicrob Agents Chemother
January 2017
GS-9620 is a potent and selective oral Toll-like receptor 7 (TLR7) agonist that directly activates plasmacytoid dendritic cells (pDCs). GS-9620 suppressed hepatitis B virus (HBV) in animal models of chronic infection and transiently activated HIV expression ex vivo in latently infected peripheral blood mononuclear cells (PBMCs) from virally suppressed patients. Currently, GS-9620 is under clinical evaluation for treating chronic HBV infection and for reducing latent reservoirs in virally suppressed HIV-infected patients.
View Article and Find Full Text PDFBictegravir (BIC; GS-9883), a novel, potent, once-daily, unboosted inhibitor of HIV-1 integrase (IN), specifically targets IN strand transfer activity (50% inhibitory concentration [IC] of 7.5 ± 0.3 nM) and HIV-1 integration in cells.
View Article and Find Full Text PDFActivation of the IRE1α-XBP1 branch of the unfolded protein response (UPR) has been implicated in multiple types of human cancers, including multiple myeloma (MM). Through an in silico drug discovery approach based on protein-compound virtual docking, we identified the anthracycline antibiotic doxorubicin as an in vitro and in vivo inhibitor of XBP1 activation, a previously unknown activity for this widely utilized cancer chemotherapeutic drug. Through a series of mechanistic and phenotypic studies, we showed that this novel activity of doxorubicin was not due to inhibition of topoisomerase II (Topo II).
View Article and Find Full Text PDFThe CTLA4-Ig therapeutics abatacept and belatacept inhibit CD28-mediated T cell activation by binding CD80 (B7-1) and CD86 (B7-2) co-stimulatory ligands. Both compounds preferentially bind CD80, yet CD86 has been implicated as the dominant co-stimulatory ligand. Using directed evolution methods, novel CTLA4-Ig variants were created with selective CD86 binding affinity, a property that confers increased immunosuppressive potency and potentially improved efficacy and safety profiles.
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