Positioning of tofacitinib in treatment of ulcerative colitis: a global perspective.

INTRODUCTION: Tofacitinib has emerged as a useful drug for the treatment of ulcerative colitis (UC). AREAS COVERED: There is an unmet need for cost-effective, non-immunogenic drugs with a safe adverse effect profile to treat patients with ulcerative colitis. In the present review, we evaluate the available literature to inform the appropriate positioning of tofacitinib in the current drug landscape and identify subsets where its use should be done with caution. EXPERT OPINION: Tofacitinib is helpful in the treatment of patients where the standard conventional or biological therapies have failed or were not tolerated. With lower costs of the generic drug than the biologicals (or biosimilars), it could be an important therapy in low- to middle-income countries. The risk of infections, especially Herpes Zoster and tuberculosis, needs to be addressed before initiation. Tofacitinib should be avoided in patients with venous thromboembolism and cardiovascular disease risk factors. Due to limited evidence, the use is not recommended in pregnancy, while it should be used with caution in elderly citizens. Future trials should look into the head-to-head comparison of tofacitinib with biologicals. The role of tofacitinib in acute severe colitis needs evaluation with comparative trials with current standards of care.

Design and Fabrication of a Gas Sensor Based on a Polypyrrole/Silver Nanoparticle Film for the Detection of Ammonia in Exhaled Breath of COVID-19 Patients Suffering from Acute Kidney Injury.

One of the serious complications of COVID-19 is acute kidney injury (AKI), leading to a decrease in kidney function and even death. The concentration of ammonia (NH3) in the exhaled breath (EB) of COVID-19 patients suffering from AKI symptoms will be significantly increased. In this work, the detection of breath NH3 was performed at gold interdigital electrodes modified with a soluble polypyrrole microparticle and silver nanoparticle film (Au-IDEs/S-PPyMPs/AgNPs) as a noninvasive chemiresistor gas sensor. The response behavior of unmodified and modified gas sensors toward NH3 and other interfering compounds was studied. The Au-IDEs/S-PPyMPs/AgNPs exhibited NH3 detection in the linear dynamic range of 1.00-19.23 ppm, with a limit of detection of 0.12 ppm. Finally, the fabricated gas sensor was used to monitor the NH3 concentration in the EB of COVID-19 patients suffering from AKI symptoms. For this purpose, the gas sensor was validated in 19 EB samples (seven COVID-19-positive patients, four COVID-19-negative patients, and eight post-COVID-19 patients). The gas sensor was directly exposed to the EB samples, followed by recording the changes in electrical resistance via a low-cost digital multimeter. The sensing mechanism was explained as the interaction between breath NH3 and sensing materials. The breath NH3 concentrations have a desirable correlation (R2 = 0.8463) with the estimated glomerular filtration rate (eGFR) values in COVID-19-positive patients. The fabricated gas sensor can distinguish COVID-19-positive patients suffering from AKI symptoms from COVID-19-negative patients and post-COVID-19 patients. The present work can pave the way for the development of a simple and efficient analytical approach for COVID-19 patients with AKI without the need for sample pretreatment.

An electrochemical paper-based hydrogel immunosensor to monitor serum cytokine for predicting the severity of COVID-19 patients.

Analysis of cytokines levels in human serum is critical as it can be a "symptom diagnostic biomarker" in COVID-19, giving real-time information about human health status. Here, we present the construction and performance of a low-price immunosensor (∼US$0.428 per test) based on microfluidic paper-based system to detect cytokine for predicting the health status of COVID-19 patients. Interleukin-6 (IL-6) was selected as the detection model for the close relationship between IL-6 and COVID-19. The assay, which we integrated into foldable paper system, leverages the magnetic immunoassay, the streptavidin-horseradish peroxidase (HRP) associated with tetramethyl benzidine/hydrogen peroxide (TMB/H2O2) to amplify the signal for electrochemical readout. To improve the sensitivity of cytokine detection, a hybrid of gold nanoparticles (AuNPs) and polypyrrole (PPy) hydrogel was modified on the working electrode to increase the conductivity and improve the electron transfer rate. With our prototypic origami paper-based immunosensor operated in differential pulse voltammetry (DPV) mode, we achieved excellent results with a dynamic range from 5 to 1000 pg/mL and a lower detection limit (LOD) of 0.654 pg/mL. Furthermore, we evaluated the capability of the clinical application of the proposed immunosensor using human serum samples from a hospital. The results indicate that our proposed immunosensor has great potential in early diagnosing high-risk COVID-19 patients.

Oligonucleotide-Recognizing Topoisomerase Inhibitors (OTIs): Precision Gene Editors for Neurodegenerative Diseases?

Topoisomerases are essential enzymes that recognize and modify the topology of DNA to allow DNA replication and transcription to take place. Topoisomerases are divided into type I topoisomerases, that cleave one DNA strand to modify DNA topology, and type II, that cleave both DNA strands. Topoisomerases normally rapidly religate cleaved-DNA once the topology has been modified. Topoisomerases do not recognize specific DNA sequences, but actively cleave positively supercoiled DNA ahead of transcription bubbles or replication forks, and negative supercoils (or precatenanes) behind, thus allowing the unwinding of the DNA-helix to proceed (during both transcription and replication). Drugs that stabilize DNA-cleavage complexes with topoisomerases produce cytotoxic DNA damage and kill fast-dividing cells; they are widely used in cancer chemotherapy. Oligonucleotide-recognizing topoisomerase inhibitors (OTIs) have given drugs that stabilize DNA-cleavage complexes specificity by linking them to either: (i) DNA duplex recognizing triplex forming oligonucleotide (TFO-OTIs) or DNA duplex recognizing pyrrole-imidazole-polyamides (PIP-OTIs) (ii) or by conventional Watson-Crick base pairing (WC-OTIs). This converts compounds from indiscriminate DNA-damaging drugs to highly specific targeted DNA-cleaving OTIs. Herein we propose simple strategies to enable DNA-duplex strand invasion of WC-OTIs giving strand-invading SI-OTIs. This will make SI-OTIs similar to the guide RNAs of CRISPR/Cas9 nuclease bacterial immune systems. However, an important difference between OTIs and CRISPR/Cas9, is that OTIs do not require the introduction of foreign proteins into cells. Recent successful oligonucleotide therapeutics for neurodegenerative diseases suggest that OTIs can be developed to be highly specific gene editing agents for DNA lesions that cause neurodegenerative diseases.

Vonoprazan Triple and Dual Therapy for Helicobacter pylori Infection in the United States and Europe: Randomized Clinical Trial.

BACKGROUND & AIMS: Novel, effective treatments for Helicobacter pylori infection are needed. This study evaluated the efficacy of vonoprazan, a potassium-competitive acid blocker, vs standard treatment on H pylori eradication in the United States and Europe. METHODS: In a randomized, controlled, phase 3 trial, treatment-naïve adults with H pylori infection were randomized 1:1:1 to open-label vonoprazan dual therapy (20 mg vonoprazan twice daily; 1 g amoxicillin 3 times daily), or double-blind triple therapy twice a day (vonoprazan 20 mg or lansoprazole 30 mg; amoxicillin 1 g; clarithromycin 500 mg) for 14 days. The primary outcome was noninferiority in eradication rates in patients without clarithromycin- and amoxicillin-resistant strains (noninferiority margin = 10%). Secondary outcomes assessed superiority in eradication rates in clarithromycin-resistant infections, and in all patients. RESULTS: A total of 1046 patients were randomized. Primary outcome eradication rates (nonresistant strains): vonoprazan triple therapy 84.7%, dual therapy 78.5%, vs lansoprazole triple therapy 78.8% (both noninferior; difference 5.9%; 95% confidence interval [CI], -0.8 to 12.6; P < .001; difference -0.3%; 95% CI, -7.4 to 6.8; P = .007, respectively). Eradication rates in clarithromycin-resistant infections: vonoprazan triple therapy 65.8%, dual therapy 69.6%, vs lansoprazole triple therapy 31.9% (both superior; difference 33.9%; 95% CI, 17.7-48.1; P < .001; difference 37.7%; 95% CI, 20.5-52.6; P < .001, respectively). In all patients, vonoprazan triple and dual therapy were superior to lansoprazole triple therapy (80.8% and 77.2%, respectively, vs 68.5%, difference 12.3%; 95% CI, 5.7-18.8; P < .001; difference 8.7%; 95% CI, 1.9-15.4; P = .013). Overall frequency of treatment-emergent adverse events was similar between vonoprazan and lansoprazole regimens (P > .05). CONCLUSION: Both vonoprazan-based regimens were superior to proton pump inhibitor-based triple therapy in clarithromycin-resistant strains and in the overall study population. CLINICALTRIALS: gov; NCT04167670.

Sunitinib-Induced Congestive Heart Failure in a Patient with Gastrointestinal Stromal Tumor.

Common cardiovascular toxicities of sunitinib mainly include hypertension, QT prolongation, left ventricular dysfunction (LVD) and less frequently, congestive heart failure (CHF). Here, we report the case of a 67-year-old woman who developed heart failure after 24 months of sunitinib. Our case highlights the importance of strict and regular cardiovascular monitoring during sunitinib. It also shows that the reintroduction of sunitinib with maintaining heart failure treatment can be safe. The exact mechanisms of this cardiotoxicity have not been understood. There is no protective therapy available. Therefore, further investigations are needed in these areas. Medical specialists who prescribe and treat patients with sunitinib should be aware of the possible occurrence of these conditions and perform regular checkup of sunitinib-treated patients.

Tofacitinib in paediatric dermatoses: a narrative review.

Tofacitinib has revolutionized the treatment of numerous dermatological conditions in different age groups. However, evidence for its effectiveness, safety and tolerability in the paediatric population is limited. We performed a literature search, which showed that oral tofacitinib is a reliable option in refractory juvenile dermatomyositis, severe alopecia areata, atopic dermatitis and psoriasis. Topical tofacitinib is an effective option in vitiligo and halo naevus. The risk-benefit ratio should be assessed prior to consideration of this molecule. In this narrative review, we have attempted to present a summary of the evidence of using tofacitinib (oral and topical) in paediatric dermatoses.

Interpatient variability in the pharmacokinetics of remdesivir and its main metabolite GS-441524 in treated COVID-19 subjects.

BACKGROUND: Remdesivir is the first antiviral drug against SARS-CoV-2 approved for use in COVID-19 patients. OBJECTIVES: To study the pharmacokinetic inter-individual variability of remdesivir and its main metabolite GS-441524 in a real-world setting of COVID-19 inpatients and to identify possible associations with different demographic/biochemical variables. METHODS: Inpatients affected by SARS-CoV-2 infections, undergoing standard-dose remdesivir treatment, were prospectively enrolled. Blood samples were collected on day 4, immediately after (C0) and at 1 h (C1) and 24 h (C24) after infusion. Remdesivir and GS-441524 concentrations were measured using a validated UHPLC-MS/MS method and the AUC0-24 was calculated. At baseline, COVID-19 severity (ICU or no ICU), sex, age, BMI and renal and liver functions were assessed. Transaminases and estimated glomerular filtration rate (e-GFR) were also evaluated during treatment. Linear regression, logistic regression and multiple linear regression tests were used for statistical comparisons of pharmacokinetic parameters and variables. RESULTS: Eighty-five patients were included. The mean (CV%) values of remdesivir were: C0 2091 (99.1%) ng/mL, C1 139.7 (272.4%) ng/mL and AUC0-24 2791 (175.7%) ng·h/mL. The mean (CV%) values of GS-441524 were: C0 90.2 (49.5%) ng/mL, C1 104.9 (46.6%) ng/mL, C24 58.4 (66.9) ng/mL and AUC0-24 1976 (52.6%) ng·h/mL. The multiple regression analysis showed that age (P < 0.05) and e-GFR (P < 0.01) were independent predictors of GS-441524 plasma exposure. CONCLUSIONS: Our results showed a high interpatient variability of remdesivir and GS-441524 likely due to both age and renal function in COVID-19 inpatients. Further research is required to understand whether the pharmacokinetics of remdesivir and its metabolites may influence drug-related efficacy or toxic effect.

Real-world evidence of the effectiveness and safety of generic tofacitinib in rheumatoid arthritis patients: a retrospective, single-centre analysis from Western India.

Generic tofacitinib has been available in India for more than a year and is widely used in rheumatoid arthritis (RA) therapy. There is scarce real-world data on its effectiveness and safety from India, especially given infection endemicity. We retrospectively analysed records (demographic and clinical information, haematology and biochemistry, adverse events) of patients prescribed generic tofacitinib from a single centre in Mumbai, India. Disease activity was calculated using the disease activity score-28 and erythrocyte sedimentation rate (DAS28-ESR) and other tools, and we used paired T-tests for significant response. We defined clinical tofacitinib failure as a composite outcome, including clinician's decision to change to an alternative disease-modifying anti-rheumatic drug (DMARD) or flare after self-withdrawal. We performed logistic regression and survival analysis for determinants of clinical failure. We reviewed records of 102 patients (92 female; median age: 53 years) with mean RA duration of 146 months. Thirteen had prior treatment with innovator tofacitinib. There was significant improvement in disease activity parameters at a mean duration of 186 days. No serious adverse events were reported; 4 patients had tuberculosis and 19 patients had mild COVID-19 while on treatment. Clinical failure was seen in 25 patients, and mean time to failure on survival analysis was 357 days. No baseline characteristic predicted clinical failure. Generic tofacitinib showed good effectiveness and a tolerable adverse effect profile, despite tuberculosis endemicity and COVID-19. Setting up registries would be valuable in gaining more data on generic tofacitinib. Key Points • There is scarce data from India regarding the use of tofacitinib in rheumatoid arthritis, despite widespread use. • In this retrospective analysis of 102 patients at a single centre, we found tofacitinib monotherapy was efficacious and tolerable. • Tuberculosis was detected in four and nineteen patients had mild covid.

Biotransformation and transplacental transfer of the anti-viral remdesivir and predominant metabolite, GS-441524 in pregnant rats.

BACKGROUND: Remdesivir was the first prodrug approved to treat coronavirus disease 2019 (COVID-19) and has the potential to be used during pregnancy. However, it is not known whether remdesivir and its main metabolite, GS-441524 have the potential to cross the blood-placental barrier. We hypothesize that remdesivir and predominant metabolite GS-441524may cross the blood-placental barrier to reach the embryo tissues. METHODS: To test this hypothesis, ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) coupled with multisite microdialysis was used to monitor the levels of remdesivir and the nucleoside analogue GS-441524 in the maternal blood, fetus, placenta, and amniotic fluid of pregnant Sprague-Dawley rats. The transplacental transfer was evaluated using the pharmacokinetic parameters of AUC and mother-to-fetus transfer ratio (AUCfetus/AUCmother). FINDINGS: Our in-vivo results show that remdesivir is rapidly biotransformed into GS-441524 in the maternal blood, which then readily crossed the placenta with a mother-to-fetus transfer ratio of 0.51 ± 0.18. The Cmax and AUClast values of GS-441524 followed the order: maternal blood > amniotic fluid > fetus > placenta in rats. INTERPRETATION: While remdesivir does not directly cross into the fetus, however, its main metabolite, GS-441524 readily crosses the placenta and can reside there for at least 4 hours as shown in the pregnant Sprague-Dawley rat model. These findings suggest that careful consideration should be taken for the use of remdesivir in the treatment of COVID-19 in pregnancy. FUNDING: Ministry of Science and Technology of Taiwan.

Novel pyrrolopyrimidine derivatives: design, synthesis, molecular docking, molecular simulations and biological evaluations as antioxidant and anti-inflammatory agents.

Current medical approaches to control the Covid-19 pandemic are either to directly target the SARS-CoV-2 via innovate a defined drug and a safe vaccine or indirectly target the medical complications of the virus. One of the indirect strategies for fighting this virus has been mainly dependent on using anti-inflammatory drugs to control cytokines storm responsible for severe health complications. We revealed the discovery of novel fused pyrrolopyrimidine derivatives as promising antioxidant and anti-inflammatory agents. The newly synthesised compounds were evaluated for their in vitro anti-inflammatory activity using RAW264.7 cells after stimulation with lipopolysaccharides (LPS). The results revealed that 3a, 4b, and 8e were the most potent analogues. Molecular docking and simulations of these compounds against COX-2, TLR-2 and TLR-4 respectively was performed. The former results were in line with the biological data and proved that 3a, 4b and 8e have potential antioxidant and anti-inflammatory effects.

Time trends for drug specific adverse events in patients on sunitinib; implications for remote monitoring.

INTRODUCTION: Sunitinib is a multi-targeted receptor tyrosine kinase inhibitor used to treat metastatic renal cell carcinoma (mRCC). Patients on sunitinib do require regular in-person appointments to monitor for adverse events (AEs). Given the Covid-19 pandemic, regular in-person visits expose patients to an increased risk of infection in addition to potentially preventable travel costs. This study investigated the feasibility of implementing a remote monitoring strategy for patients being treated with sunitinib for mRCC by examining the time trends of AEs. MATERIALS AND METHODS: In this retrospective chart review of patients with a diagnosis of mRCC, 167 patients received sunitinib during their treatment. The time between initiation of treatment and the first AE was recorded. The AEs were categorized according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5. Survival analysis was used to calculate the time-to-AE. RESULTS: Of the 167 patients identified, 145 experienced an AE (86.8%). Hypertension was the most common AE with 80% of AEs were ≤ Grade 2. Incidence of AE dropped by 91% after 3 months follow up and a further 36% after 6 months. The cumulative incidence of AEs were 87.8%, 94.6% and 98.0%, at 3, 6 and 9 months respectively. The severity of AEs observed were 39.3%, 38.6%, 20.7%, 1.4%,0% of Grade 1-5 events respectively. A trend of grade migration to less severe grades was also shown over time, with percentage of Grade ≥ 3 toxicity dropping from 22% between 0-3 months to 14% beyond 6 months follow up. CONCLUSIONS: The role of remote monitoring for mRCC patients on sunitinib remains relevant now with new waves of the Covid-19 pandemic, triggered by novel variants. The majority of AEs observed were of low severity ≤ Grade 2, with a trend of reduced AE frequency and severity most prevalent beyond 3 months of follow up. This data appears to support the implementation of a remote monitoring strategy 3 months after initiation of treatment.

SARS-CoV-2 Causes Lung Inflammation through Metabolic Reprogramming and RAGE.

Clinical studies indicate that patients infected with SARS-CoV-2 develop hyperinflammation, which correlates with increased mortality. The SARS-CoV-2/COVID-19-dependent inflammation is thought to occur via increased cytokine production and hyperactivity of RAGE in several cell types, a phenomenon observed for other disorders and diseases. Metabolic reprogramming has been shown to contribute to inflammation and is considered a hallmark of cancer, neurodegenerative diseases, and viral infections. Malfunctioning glycolysis, which normally aims to convert glucose into pyruvate, leads to the accumulation of advanced glycation end products (AGEs). Being aberrantly generated, AGEs then bind to their receptor, RAGE, and activate several pro-inflammatory genes, such as IL-1b and IL-6, thus, increasing hypoxia and inducing senescence. Using the lung epithelial cell (BEAS-2B) line, we demonstrated that SARS-CoV-2 proteins reprogram the cellular metabolism and increase pyruvate kinase muscle isoform 2 (PKM2). This deregulation promotes the accumulation of AGEs and senescence induction. We showed the ability of the PKM2 stabilizer, Tepp-46, to reverse the observed glycolysis changes/alterations and restore this essential metabolic process.

Comparative bioavailability study following a single dose intravenous and buccal administration of remdesivir in rabbits.

As remdesivir, the first FDA-approved drug for SARS-CoV-2 infection, can be used only for hospitalized patients due to intravenous administration, there is an urgent need of effective oral antiviral formulations to be used at early stage of infection in an outpatient setting. The present paper reports on the comparative pharmacokinetics of the electrospun nanofiber remdesivir/sulfobutyl ether beta-cyclodextrin formulation after intravenous and buccal administration. It was postulated that oral transmucosal administration avoids remdesivir from metabolic transformation and intact remdesivir can be detected in plasma, but only the active metabolite GS-441524 could be experimentally detected at a significantly lower plasma level, than that provided by the intravenous route. In buccally treated animals, the metabolite GS-441524 appeared only at 1 h after treatment, while in intravenously treated animals, GS-441524 was possible to quantify even at the first time-point of blood collection. Further optimization of formulation is required to improve pharmacokinetics of remdesivir-sulfobutyl ether beta-cyclodextrin formulation upon buccal administration.

Antifungal Activity of Fibrate-Based Compounds and Substituted Pyrroles That Inhibit the Enzyme 3-Hydroxy-methyl-glutaryl-CoA Reductase of Candida glabrata (CgHMGR), Thus Decreasing Yeast Viability and Ergosterol Synthesis.

Due to the emergence of multidrug-resistant strains of yeasts belonging to the Candida genus, there is an urgent need to discover antifungal agents directed at alternative molecular targets. The aim of the current study was to evaluate the capacity of three different series of synthetic compounds to inhibit the Candida glabrata enzyme denominated 3-hydroxy-methyl-glutaryl-CoA reductase and thus affect ergosterol synthesis and yeast viability. Compounds 1c (α-asarone-related) and 5b (with a pyrrolic core) were selected as the best antifungal candidates among over 20 synthetic compounds studied. Both inhibited the growth of fluconazole-resistant and fluconazole-susceptible C. glabrata strains. A yeast growth rescue experiment based on the addition of exogenous ergosterol showed that the compounds act by inhibiting the mevalonate synthesis pathway. A greater recovery of yeast growth occurred for the C. glabrata 43 fluconazole-resistant (versus fluconazole-susceptible) strain and after treatment with 1c (versus 5b). Given that the compounds decreased the concentration of ergosterol in the yeast strains, they probably target ergosterol synthesis. According to the docking analysis, the inhibitory effect of 1c and 5b could possibly be mediated by their interaction with the amino acid residues of the catalytic site of the enzyme. Since 1c displayed higher binding energy than α-asarone and 5b, it is the best candidate for further research, which should include structural modifications to increase its specificity and potency. The derivatives could then be examined with in vivo animal models using a therapeutic dose. IMPORTANCE Within the context of the COVID-19 pandemic, there is currently an epidemiological alert in health care services due to outbreaks of Candida auris, Candida glabrata, and other fungal species multiresistant to conventional antifungals. Therefore, it is important to propose alternative molecular targets, as well as new antifungals. The three series of synthetic compounds herein designed and synthesized are inhibitors of ergosterol synthesis in yeasts. Of the more than 20 compounds studied, two were selected as the best antifungal candidates. These compounds were able to inhibit the growth and synthesis of ergosterol in C. glabrata strains, whether susceptible or resistant to fluconazole. The rational design of antifungal compounds derived from clinical drugs (statins, fibrates, etc.) has many advantages. Future studies are needed to modify the structure of the two present test compounds to obtain safer and less toxic antifungals. Moreover, it is important to carry out a more in-depth mechanistic approach.

Synthesis Strategies and Medicinal Value of Pyrrole and its Fused Heterocyclic Compounds.

In the last several decades, interest in pyrrole and pyrrolopyrimidine derivatives has increased owing to their biological importance, such as anti-tumor, anti-microbial, anti-inflammatory, anti-diabetic, anti-histaminic, anti-malarial, anti-Parkinson, antioxidant and anti-viral effects, specially recently against COVID-19. These tremendous biological features have motivated scientists to discover more pyrrole and fused pyrrole derivatives, owing to the great importance of the pyrrole nucleus as a pharmacophore in many drugs, and motivated us to present this article, highlighting on the different synthetic pathways of pyrrole and its fused compounds, specially pyrrolopyrimidine, as well as their medicinal value from 2017 till 2021.

Inhibitors of Anti-apoptotic Bcl-2 Family Proteins Exhibit Potent and Broad-Spectrum Anti-mammarenavirus Activity via Cell Cycle Arrest at G0/G1 Phase.

Targeting host factors is a promising strategy to develop broad-spectrum antiviral drugs. Drugs targeting anti-apoptotic Bcl-2 family proteins that were originally developed as tumor suppressors have been reported to inhibit multiplication of different types of viruses. However, the mechanisms whereby Bcl-2 inhibitors exert their antiviral activity remain poorly understood. In this study, we have investigated the mechanisms by which obatoclax (OLX) and ABT-737 Bcl-2 inhibitors exhibited a potent antiviral activity against the mammarenavirus lymphocytic choriomeningitis virus (LCMV). OLX and ABT-737 potent anti-LCMV activity was not associated with their proapoptotic properties but rather with their ability to induce cell arrest at the G0/G1 phase. OLX- and ABT-737-mediated inhibition of Bcl-2 correlated with reduced expression levels of thymidine kinase 1 (TK1), cyclin A2 (CCNA2), and cyclin B1 (CCNB1) cell cycle regulators. In addition, small interfering RNA (siRNA)-mediated knockdown of TK1, CCNA2, and CCNB1 resulted in reduced levels of LCMV multiplication. The antiviral activity exerted by Bcl-2 inhibitors correlated with reduced levels of viral RNA synthesis at early times of infection. Importantly, ABT-737 exhibited moderate efficacy in a mouse model of LCMV infection, and Bcl-2 inhibitors displayed broad-spectrum antiviral activities against different mammarenaviruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our results suggest that Bcl-2 inhibitors, actively being explored as anticancer therapeutics, might be repositioned as broad-spectrum antivirals. IMPORTANCE Antiapoptotic Bcl-2 inhibitors have been shown to exert potent antiviral activities against various types of viruses via mechanisms that are currently poorly understood. This study has revealed that Bcl-2 inhibitors' mediation of cell cycle arrest at the G0/G1 phase, rather than their proapoptotic activity, plays a critical role in blocking mammarenavirus multiplication in cultured cells. In addition, we show that Bcl-2 inhibitor ABT-737 exhibited moderate antimammarenavirus activity in vivo and that Bcl-2 inhibitors displayed broad-spectrum antiviral activities against different mammarenaviruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our results suggest that Bcl-2 inhibitors, actively being explored as anticancer therapeutics, might be repositioned as broad-spectrum antivirals.

Zwitterionic Polymer Electroplating Facilitates the Preparation of Electrode Surfaces for Biosensing.

Surface chemistry critically affects the diagnostic performance of biosensors. An ideal sensor surface should be resistant to nonspecific protein adsorption, yet be conducive to analytical responses. Here a new polymeric material, zwitterionic polypyrrole (ZiPPy), is reported to produce optimal surface condition for biosensing electrodes. ZiPPy combines two unique advantages: the zwitterionic function that efficiently hydrates electrode surface, hindering nonspecific binding of hydrophobic proteins; and the pyrrole backbone, which enables rapid (<7 min), controlled deposition of ZiPPy through electropolymerization. ZiPPy-coated electrodes show lower electrochemical impedance and less nonspecific protein adsorption (low fouling), outperforming bare and polypyrrole-coated electrodes. Moreover, affinity ligands for target biomarkers can be immobilized together with ZiPPy in a single-step electropolymerization. ZiPPy-coated electrodes are developed with specificity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The prepared sensor detects SARS-CoV-2 antibodies in human saliva down to 50 ng mL-1 , without the need for sample purification or secondary labeling.

Obatoclax inhibits SARS-CoV-2 entry by altered endosomal acidification and impaired cathepsin and furin activity in vitro.

Coronavirus disease 2019 (COVID-19) caused by the emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has set off a global pandemic. There is an urgent unmet need for safe, affordable, and effective therapeutics against COVID-19. In this regard, drug repurposing is considered as a promising approach. We assessed the compounds that affect the endosomal acidic environment by applying human angiotensin-converting enzyme 2 (hACE2)- expressing cells infected with a SARS-CoV-2 spike (S) protein-pseudotyped HIV reporter virus and identified that obatoclax resulted in the strongest inhibition of S protein-mediated virus entry. The potent antiviral activity of obatoclax at nanomolar concentrations was confirmed in different human lung and intestinal cells infected with the SARS-CoV-2 pseudotype system as well as clinical virus isolates. Furthermore, we uncovered that obatoclax executes a double-strike against SARS-CoV-2. It prevented SARS-CoV-2 entry by blocking endocytosis of virions through diminished endosomal acidification and the corresponding inhibition of the enzymatic activity of the endosomal cysteine protease cathepsin L. Additionally, obatoclax impaired the SARS-CoV-2 S-mediated membrane fusion by targeting the MCL-1 protein and reducing furin protease activity. In accordance with these overarching mechanisms, obatoclax blocked the virus entry mediated by different S proteins derived from several SARS-CoV-2 variants of concern such as, Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2). Taken together, our results identified obatoclax as a novel effective antiviral compound that keeps SARS-CoV-2 at bay by blocking both endocytosis and membrane fusion. Our data suggested that obatoclax should be further explored as a clinical drug for the treatment of COVID-19.