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Background Critical drug-drug interactions (DDI) and hepatotoxicity complicate concurrent use of rifampicin and protease inhibitors. We investigated whether dose escalation of atazanavir/ritonavir could safely overcome the DDI with rifampicin. Methods DERIVE (NCT04121195, EDCTP) was a dose-escalation trial in people with human immunodeficiency virus (HIV) on atazanavir/ritonavir-based antiretroviral therapy (ART) in Uganda. Four intensive pharmacokinetic (PK) visits were performed: PK1 300/100 mg OD (baseline); PK2 300/100 mg OD with rifampicin 600 mg; PK3 300/100 mg twice a day (BID) with rifampicin 600 mg OD; PK4 300/100 mg BID with rifampicin 1200 mg OD. Dolutegravir 50 mg BID throughout the study period ensured participants remained protected from subtherapeutic atazanavir concentrations. The data were interpreted with noncompartmental analysis. The target minimum concentration was atazanavir's protein-adjusted IC90 (PA-IC90), 0.014 mg/L. Results We enrolled 26 participants (23 female) with median (range) age 44 (28–61) years and weight 67 (50–75) kg. Compared with PK1, atazanavir Ctau, and AUC were significantly reduced at PK2 by 96% and 85%, respectively. The escalation to BID dosing (PK3) reduced this difference in Ctau, and AUC24 to 18% lower and 8% higher, respectively. Comparable exposures were maintained with double doses of rifampicin. Lowest Ctau during PK1, PK3, and PK4 were 12.7-, 4.8-, and 8.6-fold higher than PA-IC90, respectively, whereas 65% of PK2 Ctau were below the limit of quantification (0.03 mg/L), hence likely below PA-IC90. No participant developed significant elevation of liver enzymes, reported a serious adverse event (SAE) or experienced rebound viraemia. Conclusions Twice daily atazanavir/ritonavir during rifampicin co-administration was well tolerated and achieved plasma concentrations above the target. Clinical Trials Registration NCT04121195. Registered on 09 October 2019, https://clinicaltrials.gov/ct2/show/NCT04121195. [ABSTRACT FROM AUTHOR]

Objective: This study investigates the role of Apoptotic Protease Activating Factor-1 (APAF-1) in CD4+ cell depletion among human immunodeficiency virus (HIV) patients. Materials and Methods: This is a cross-sectional study in which 105 participants were enrolled, including 60 confirmed HIV-positive patients and 45 HIV-negative controls. HIV-positive patients were further divided based on CD4+ cell counts: Group 1 (<200), Group 2 (200–499), and Group 3 (≥500). An enzyme-linked immunoassay was used to measure APAF-1 levels, and CD4+ T-cell counts were enumerated using a Cyflow counter. Independent student’s t-test, Kruskal-Wallis, and Spearman’s correlation were utilized as needed. Results: Results showed significant reductions in lymphocytes, platelets, red blood cells, hemoglobin, albumin, and CD4+ cell values among HIV-infected individuals compared to controls. Conversely, APAF-1 and total protein levels were elevated in HIV-positive patients. Among HIV-positive groups, those with CD4+ cell counts <200 exhibited the highest median serum APAF-1 concentration. However, these differences were not statistically significant when compared with the other seropositive groups with CD4+ cell counts between 200 and 499 (P = 0.6726) and CD4+ cell counts of 500 or greater (P = 0.4325). The control group had the lowest median SAPAF-1 concentration, significantly different from HIV-positive groups. Positive correlations were observed between CD4+ counts and lymphocytes, hemoglobin, and hypoalbuminemia, while negative correlations were found between these parameters and APAF-1 levels. Conclusion: APAF-1 is a host factor that potentially contributes to CD4+ cell depletion. Similarly, APAF-1, serum total protein, and albumin levels were found to be predictive of disease progression and could serve as valuable diagnostic biomarkers in the monitoring of HIV/AIDS. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The present study probes into the role and mechanism of ubiquitin specific peptidase 14 (USP14) in coronary heart disease (CHD)-triggered endothelial cell pyroptosis. METHODS: An in vitro CHD model was established by inducing human coronary artery endothelial cells (HCAECs) with oxidized low-density lipoprotein (ox-LDL). HCAECs were transfected with si-USP14, followed by evaluation of cell viability by CCK-8 assay, detection of lactate dehydrogenase (LDH) activity by assay kit, detection of USP14, miR-15b-5p, NLRP3, GSDMD-N, and Cleaved-Caspase-1 expressions by qRT-PCR or Western blot, as well as IL-1β and IL-18 concentrations by ELISA. Co-IP confirmed the binding between USP14 and NLRP3. The ubiquitination level of NLRP3 in cells was measured after protease inhibitor MG132 treatment. Dual-luciferase reporter assay verified the targeting relationship between miR-15b-5p and USP14. RESULTS: USP14 and NLRP3 were highly expressed but miR-15b-5p was poorly expressed in ox-LDL-exposed HCAECs. USP14 silencing strengthened the viability of ox-LDL-exposed HCAECs, reduced the intracellular LDH activity, and diminished the NLRP3, GSDMD-N, Cleaved-Caspase-1, IL-1β, and IL-18 expressions. USP14 bound to NLRP3 protein and curbed its ubiquitination. Repression of NLRP3 ubiquitination counteracted the inhibitory effect of USP14 silencing on HCAEC pyroptosis. miR-15b-5p restrained USP14 transcription and protein expression. miR-15b-5p overexpression alleviated HCAEC pyroptosis by suppressing USP14/NLRP3. CONCLUSION: USP14 stabilizes NLRP3 protein expression through deubiquitination, thereby facilitating endothelial cell pyroptosis in CHD. miR-15b-5p restrains endothelial cell pyroptosis by targeting USP14 expression. [ABSTRACT FROM AUTHOR]

The X-ray diffraction analysis of two polymorphs of sodium (cis)-N-((4-(2-(4-bromo-3-(3-chloro-5-cyanophenoxy)-2-fluorophenyl)acetamido)-3-chlorophenyl)sulfonyl)propioimide shows that the organic anion in them is in elongated and globular conformations. Both conformations are characterized by the absence of strong intramolecular interactions. According to the quantum chemical study, both the isolated anion in the globular conformation and the polymorph containing it are more thermodynamically stable, and the difference in free energies of the polymorphs increases with temperature, which is explained by the role of the entropy factor. The elongated conformation is stabilized in the crystal by interanionic Hal...π interactions and stacking interactions involving the phenyl groups. [ABSTRACT FROM AUTHOR]

The increasing incidence and dissemination of multidrug-resistant Candida auris represents a serious global threat. The emergence of pan-resistant C. auris exhibiting resistance to all three classes of antifungals magnifies the need for novel therapeutic interventions. We identified that two HIV protease inhibitors, atazanavir and saquinavir, in combination with posaconazole exhibited potent activity against C. auris in vitro and in vivo. Both atazanavir and saquinavir exhibited a remarkable synergistic activity with posaconazole against all tested C. auris isolates and other medically important Candida species. In a time-kill assay, both drugs restored the fungistatic activity of posaconazole, resulting in reduction of 5 and 5.6 log10, respectively. Furthermore, in contrast to the individual drugs, the two combinations effectively inhibited the biofilm formation of C. auris by 66.2 and 81.2%, respectively. Finally, the efficacy of the two combinations were tested in a mouse model of C. auris infection. The atazanavir/posaconazole and saquinavir/posaconazole combinations significantly reduced the C. auris burden in mice kidneys by 2.04- (99.1%) and 1.44-log10 (96.4%) colony forming unit, respectively. Altogether, these results suggest that the combination of posaconazole with the HIV protease inhibitors warrants further investigation as a new therapeutic regimen for the treatment of C. auris infections. [ABSTRACT FROM AUTHOR]

We focus on drug repurposing in the Ras signaling pathway, considering structural similarities of protein–protein interfaces. The interfaces formed by physically interacting proteins are found from PDB if available and via PRISM (PRotein Interaction by Structural Matching) otherwise. The structural coverage of these interactions has been increased from 21 to 92% using PRISM. Multiple conformations of each protein are used to include protein dynamics and diversity. Next, we find FDA-approved drugs bound to structurally similar protein–protein interfaces. The results suggest that HIV protease inhibitors tipranavir, indinavir, and saquinavir may bind to EGFR and ERBB3/HER3 interface. Tipranavir and indinavir may also bind to EGFR and ERBB2/HER2 interface. Additionally, a drug used in Alzheimer's disease can bind to RAF1 and BRAF interface. Hence, we propose a methodology to find drugs to be potentially used for cancer using a dataset of structurally similar protein–protein interface clusters rather than pockets in a systematic way. [ABSTRACT FROM AUTHOR]

This article, published in the journal Thoracic & Cardiovascular Surgeon, explores the potential benefits of inhibiting the cysteine protease cathepsin C (CatC) in improving graft function after heart transplantation (HTX) in rats. The study found that the CatC inhibitor BI-9740 decreased the activity of neutrophil serine proteases and improved graft function in terms of both systolic and diastolic function. Additionally, the inhibitor was associated with a shorter graft re-beating time. These findings suggest that pharmacological inhibition of CatC may be a promising approach to enhance graft outcomes after HTX. [Extracted from the article]

Background: HIV infection continues to be a global public health challenge, affecting approximately 1.7 million reproductive-aged women. Protease inhibitor-based highly active antiretroviral therapy (PI-HAART) has significantly reduced the risk of vertical transmission of HIV from mother to child. Nevertheless, concerns linger regarding the long-term effects, particularly on body composition, notably subcutaneous fat tissue (SFT). Although HIV-associated lipodystrophy syndrome (LS) has been well documented in adults and older children, its impact on fetuses exposed to PI-HAART remains underexplored. This study aims to evaluate SFT in the fetuses of HIV-pregnant women exposed to PI-HAART, assessing the potential clinical implications. Methods: We conducted a comparative study between HIV-pregnant women receiving PI-HAART and an HIV-negative control group. Fetometry measurements were obtained via 3D ultrasound. SFT in the fetal arm and thigh segments was assessed. Data were analyzed using lineal multivariate regression and receiver-operating characteristics (ROC)-curve analysis. Results: Fetuses exposed to PI-HAART exhibited a significant reduction in subcutaneous fat, particularly in the proximal third-middle union of the femur (coefficient: −2.588, p = 0.042). This reduction was correlated with lower newborn serum glucose levels (65.7 vs. 56.1, p = 0.007; coefficient: −1.277, p = 0.045). Conclusions: Our study sheds light on the connection between PI-HAART, fetal subcutaneous fat, and neonatal health. These findings might reveal the long-lasting effects of PI-HAART on newborns and children's well-being. Our results emphasize the need for a more balanced approach to managing pregnant women with HIV in developing countries and open new venues for research on the impact of intrauterine PI-HAART exposure on energy metabolism and fetal programming. [ABSTRACT FROM AUTHOR]

Human society is facing the threat of various viruses. Proteases are promising targets for the treatment of viral infections. In this study, we collected and profiled 170 protease sequences from 125 viruses that infect humans. Approximately 73 of them are viral 3-chymotrypsin-like proteases (3CLpro), and 11 are pepsin-like aspartic proteases (PAPs). Their sequences, structures, and substrate characteristics were carefully analyzed to identify their conserved nature for proposing a pan-3CLpro or pan-PAPs inhibitor design strategy. To achieve this, we used computational prediction and modeling methods to predict the binding complex structures for those 73 3CLpro with 4 protease inhibitors of SARS-CoV-2 and 11 protease inhibitors of HCV. Similarly, the complex structures for the 11 viral PAPs with 9 protease inhibitors of HIV were also obtained. The binding affinities between these compounds and proteins were also evaluated to assess their pan-protease inhibition via MM-GBSA. Based on the drugs targeting viral 3CLpro and PAPs, repositioning of the active compounds identified several potential uses for these drug molecules. As a result, Compounds 1–2, modified based on the structures of Ray1216 and Asunaprevir, indicate potential inhibition of DENV protease according to our computational simulation results. These studies offer ideas and insights for future research in the design of broad-spectrum antiviral drugs. [ABSTRACT FROM AUTHOR]

Objective: Toll-like receptor 4 (TLR4) is crucial in induction of innate immune response through recognition of invading pathogens or endogenous alarming molecules. Ligand-triggered dimerization of TLR4 is essential for the activation of NF-κB and IRF3 through MyD88- or TRIF-dependent pathways. Saquinavir (SQV), an FDA-approved HIV protease inhibitor, has been shown to attenuate the activation of NF-κB induced by HMGB1 by blocking TLR4-MyD88 association in proteasome independent pathway. This study aims to define whether SQV is an HMGB1-specific and MyD88-dependent TLR4 signaling inhibitor and which precise signaling element of TLR4 is targeted by SQV. Materials and Methods: PMA differentiated human THP-1 macrophages or reconstituted HEK293 cells were pretreated with SQV before stimulated by different TLR agonists. TNF-a level was evaluated through ELISA assay. NF-κB activation was analyzed using NF-κB SEAP reporting system. The levels of MyD88/TRIF pathways-related factors were examined by immunoblot. TLR4 endocytosis was assessed by immunocytochemistry. TLR4 dimerization was determined using immunoprecipitation between different tagged TLR4 and an in silico molecular docking experiment was performed to explore the possible binding site of SQV on its target. Results: Our data showed that SQV suppresses both MyD88- and TRIF-dependent pathways in response to lipopolysaccharide (LPS), a critical sepsis inducer and TLR4 agonist, leading to downregulation of NF-κB and IRF3. SQV did not suppress MyD88-dependent pathway triggered by TLR1/2 agonist Pam3csk4. In the only TRIF-dependent pathway, SQV did not alleviate IRF3 phosphorylation induced by TLR3 agonist Poly(I:C). Furthermore, dimerization of TLR4 following LPS or HMGB1 stimulation was decreased by SQV. Conclusion: We concluded that TLR4 receptor complex is one of the mammalian targets of SQV, and TLR4-mediated immune responses and consequent risk for uncontrolled inflammation could be modulated by FDA-approved drug SQV. [ABSTRACT FROM AUTHOR]

Even though SARS-CoV-2 was declared by WHO as constituting no longer a public health emergency, the development of effective treatments against SARS-CoV-2 infection remains a critical issue to prevent complications, particularly in fragile patients. The protease inhibitor nafamostat, currently used in Japan and Korea for pancreatitis, owing to its anticoagulant properties for disseminated intravascular coagulation (DIC), is appealing for the treatment of COVID-19 infection, because it potently inhibits the transmembrane protease serine 2 (TMPRSS2) that, after virus binding to ACE-2, allows virus entry into the cells and replication. Moreover, it could prevent the DIC and pulmonary embolism frequently associated with COVID-19 infection. The goal of the RAndomized Clinical Trial Of NAfamostat (RACONA) study, designed as a prospective randomized, double-blind placebo-controlled clinical trial, was to investigate the efficacy and safety of nafamostat mesylate (0.10 mg/kg/h iv for 7 days), on top of the optimal treatment, in COVID-19 hospitalized patients. We could screen 131 patients, but due to the predefined strict inclusion and exclusion criteria, only 15 could be randomized to group 1 (n = 7) or group 2 (n = 8). The results of an ad interim safety analysis showed similar overall trends for variables evaluating renal function, coagulation, and inflammation. No adverse events, including hyperkalemia, were found to be associated with nafamostat. Thus, the RACONA study showed a good safety profile of nafamostat, suggesting that it could be usefully used in COVID-19 hospitalized patients. [ABSTRACT FROM AUTHOR]

Ritonavir, a protease inhibitor, is used to treat HIV/AIDS. Rarely does it function as a stand-alone antiviral medication, instead enhancing the antiviral effects of other protease inhibitors. Ritonavir was first created to block the HIV protease, however, research suggests that it also blocks cytochrome P450-3A4. Due to its manner of action, ritonavir is currently being studied for use in treating several types of cancer. It is additionally used in concert with other drugs to treat the Hepatitis C infection. The indications, dose, administration, adverse event profile, modes of action, toxicity, and contraindications of ritonavir are covered in this review. These observations can lead to new therapeutic indications of protease inhibitors to treat several cancers however, substantial extensive research is to be needed before clinical approval. [ABSTRACT FROM AUTHOR]

The use of protease inhibitors in human immunodeficiency virus type 1 (HIV-1) treatment is limited by adverse effects, including metabolic complications. To address these challenges, efforts are underway in the pursuit of more potent and less toxic HIV-1 protease inhibitors. Repurposing existing drugs offers a promising avenue to expedite the drug discovery process, saving both time and costs compared to conventional de novo drug development. This study screened FDA-approved and investigational drugs in the DrugBank database for their potential as HIV-1 protease inhibitors. Molecular docking studies and cell-based assays, including anti-HIV-1 in vitro assays and XTT cell viability tests, were conducted to evaluate their efficacy. The study findings revealed that CBR003PS, an antibiotic currently in clinical use, and CBR013PS, an investigational drug for treating endometriosis and uterine fibroids, exhibited significant binding affinity to the HIV-1 protease with high stability. Their EC50 values, measured at 100% cell viability, were 9.4 nM and 36.6 nM, respectively. Furthermore, cell-based assays demonstrated that these two compounds showed promising results, with therapeutic indexes higher than 32. In summary, based on their favorable therapeutic indexes, CBR003PS and CBR013PS show potential for repurposing as HIV-1 protease inhibitors. [ABSTRACT FROM AUTHOR]

Nirmatrelvir/ritonavir (Paxlovid) is indicated in patients who are at high risk of progressing to severe COVID-19. Many of these patients are concomitantly prescribed various medications for other indications. Ritonavir has no activity against SARS-CoV-2, but, administered with nirmatrelvir, acts as a pharmacokinetic booster, increasing nirmatrelvir’s efficacy. Ritonavir can simultaneously change other medicines’ plasma levels, affecting their safety and therapeutic effects. Ritonavir’s potential to cause clinically significant interactions is well documented, as it has a long history of being used as a pharmacokinetic enhancer with other antiviral agents. Pharmacokinetic drug-drug interactions (DDIs) are a well-known phenomenon, but data on the clinical impact of Paxlovid DDIs is still insufficient. Ritonavir in the treatment of COVID-19 is only administered for 5 days; therefore, uncertainty exists on how the coadministration of various medicines should be managed. Numerous Paxlovid DDIs can lead to serious adverse drug reactions; therefore, careful analysis of all concomitantly prescribed medicines is essential to ensure treatment safety. This article aims to summarise currently available information on Paxlovid DDIs that may be relevant for general practitioners. It explains the main mechanisms leading to pharmacokinetic interactions and possible options for DDIs management. The authors indicate sources of information that may be helpful to prescribers when weighing the benefits and risks of Paxlovid co-administration with other medicines. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the studies described in this mini review article was to identify nontoxic compounds that could prevent or suppress the radiation induced malignant transformation of cells and be useful as human cancer preventive agents. Conclusions: (1) Many different types of potential anticarcinogenic substances were evaluated initially for their abilities to prevent or suppress radiation induced malignant transformation in vitro, and certain anticarcinogenic protease inhibitors (APIs) were observed to be the most powerful anticarcinogenic agents at suppressing this surrogate endpoint biomarker of radiation carcinogenesis. (2) Within the category of APIs, those that inhibited the activity of chymotrypsin were effective at far lower molar concentrations than other APIs. The soybean-derived protease inhibitor known as the Bowman-Birk inhibitor (BBI) is a particularly powerful chymotrypsin inhibitor that is able to prevent radiation induced transformation in vitro (at concentrations down to nanomolar levels) as well as radiation induced carcinogenesis in vivo without toxicity. (3) There were many other unusual characteristics of APIs that led to the selection of one of these APIs, BBI, as the most appropriate compound for us to develop as a human cancer preventive agent. As one example, the APIs have an irreversible effect on carcinogenesis, while the effects are reversible for most anticarcinogenic agents when they are removed from carcinogenesis assay systems. (4) Numerous studies were performed in attempts to determine the potential mechanisms by which the APIs could prevent or suppress radiation induced carcinogenesis in in vitro and in vivo systems, and the results of these studies are described in this review article. The APIs and the proteases which interact with them appear to play important roles in radiation carcinogenesis. (5) Preparations for human trials using BBI began decades ago. The cost of preparing purified BBI was far too high to consider performing human trials with this agent, so BBI Concentrate (BBIC), a soybean extract enriched in BBI, was developed for the specific purpose of performing human trials with BBI. BBIC achieved Investigational New Drug (IND) Status with the Food and Drug Administration in April, 1992, and human BBIC trials began at that time. (6) Several human trials were performed using BBIC and they indicated many potentially beneficial health effects produced by BBIC administration to people in various forms (e.g. tablets). 7) It is hypothesized that BBI takes the place of a-1-antichymotrypsin, an important regulatory compound in the human body, and helps to maintain homeostasis. [ABSTRACT FROM AUTHOR]

Background: Brensocatib is an oral, selective, reversible inhibitor of dipeptidyl peptidase-1 (DPP-1), responsible for activating neutrophil serine proteases (NSPs) including neutrophil elastase (NE), proteinase 3 (PR3), and cathepsin G (CatG). In chronic inflammatory lung diseases such as non-cystic fibrosis bronchiectasis (NCFBE), neutrophils accumulate in the airways resulting in excess active NSPs that cause damaging inflammation and lung destruction. Methods: The 24-week WILLOW trial (NCT03218917) was a randomized, double-blind, placebo-controlled, parallel-group trial in patients with NCFBE conducted at 116 sites across 14 countries. In this trial, treatment with brensocatib was associated with improvements in clinical outcomes including time to first exacerbation, reduction in exacerbation frequency and a reduction in NE activity in sputum. An exploratory analysis of NE activity in white blood cell (WBC) extracts and NE, PR3 and CatG activity in sputum was conducted to further characterize brensocatib's effect and identify potential correlated effects. Results: NE, PR3 and CatG activities were reduced in sputum and NE activity was reduced in WBC extracts in a dose-dependent manner after four weeks of brensocatib treatment, with a return to baseline four weeks after the end of treatment. Brensocatib produced the greatest reduction in the sputum activity of CatG, followed by NE and then PR3. Positive correlations among the sputum NSPs were observed both at baseline and in response to treatment, with the strongest correlation among the sputum NSPs for NE and CatG. Conclusions: These results suggest a broad anti-inflammatory effect of brensocatib underlying its clinical efficacy observed in NCFBE patients. Trial registration: The study was approved by the corresponding ethical review boards of all participating centers. The trial was approved by the Food and Drug Administration and registered at clinicaltrials.gov (NCT03218917) on July 17, 2017 and approved by the European Medicines Agency and registered at the European Union Clinical trials Register (EudraCT No. 2017-002533-32). An independent, external data and safety monitoring committee (comprising physicians with pulmonary expertise, a statistician experienced in the evaluation of clinical safety, and experts in periodontal disease and dermatology) reviewed all adverse events. [ABSTRACT FROM AUTHOR]

Background The Russian invasion of Ukraine forced migration for safety, protection, and assistance. Poland is the primary sheltering country for Ukrainian refugees, providing support including medical care, which resulted in the rapid ∼15% increase in the number of followed-up people with human immunodeficiency virus (HIV) (PWH) in the country. Here, we present the national experience on HIV care provided for refugees from Ukraine. Methods Clinical, antiretroviral, immunological, and virologic data from 955 Ukrainian PWH entering care in Poland since February 2022 were analyzed. The dataset included both antiretroviral-treated (n = 851) and newly diagnosed (n = 104) patients. In 76 cases, protease/reverse transcriptase/integrase sequencing was performed to identify drug resistance and subtype. Results Most (70.05%) of the patients were female, with a predominance of heterosexual (70.3%) transmissions. Anti–hepatitis C antibody and hepatitis B antigen were present in 28.7% and 2.9% of the patients, respectively. A history of tuberculosis was reported in 10.1% of cases. Among previously treated patients, the viral suppression rate was 89.6%; 77.3% of newly HIV diagnosed cases were diagnosed late (with lymphocyte CD4 count <350 cells/μL or AIDS). The A6 variant was observed in 89.0% of sequences. Transmitted mutations in the reverse transcriptase were found in 15.4% treatment-naive cases. Two patients with treatment failure exhibited multiclass drug resistance. Conclusions Migration from Ukraine influences the characteristics of HIV epidemics in Europe, with an increase in the proportion of women and hepatitis C coinfected patients. Antiretroviral treatment efficacy among previously treated refugees was high, with new HIV cases frequently diagnosed late. The A6 subtype was the most common variant. [ABSTRACT FROM AUTHOR]

The availability of drugs capable of blocking the replication of microorganisms has been one of the greatest triumphs in the history of medicine, but the emergence of an ever-increasing number of resistant strains poses a serious problem for the treatment of infectious diseases. The search for new potential ligands for proteins involved in the life cycle of pathogens is, therefore, an extremely important research field today. In this work, we have considered the HIV-1 protease, one of the main targets for AIDS therapy. Several drugs are used today in clinical practice whose mechanism of action is based on the inhibition of this enzyme, but after years of use, even these molecules are beginning to be interested by resistance phenomena. We used a simple artificial intelligence system for the initial screening of a data set of potential ligands. These results were validated by docking and molecular dynamics, leading to the identification of a potential new ligand of the enzyme which does not belong to any known class of HIV-1 protease inhibitors. The computational protocol used in this work is simple and does not require large computational power. Furthermore, the availability of a large number of structural information on viral proteins and the presence of numerous experimental data on their ligands, with which it is possible to compare the results obtained with computational methods, make this research field the ideal terrain for the application of these new computational techniques. [ABSTRACT FROM AUTHOR]

Human Immunodeficiency Virus type 1 protease (HIV-1 PR) is one of the most challenging targets of antiretroviral therapy used in the treatment of AIDS-infected people. The performance of protease inhibitors (PIs) is limited by the development of protease mutations that can promote resistance to the treatment. The current study was carried out using statistics and bioinformatics tools. A series of thirty-three compounds with known enzymatic inhibitory activities against HIV-1 protease was used in this paper to build a mathematical model relating the structure to the biological activity. These compounds were designed by software; their descriptors were computed using various tools, such as Gaussian, Chem3D, ChemSketch and MarvinSketch. Computational methods generated the best model based on its statistical parameters. The model's applicability domain (AD) was elaborated. Furthermore, one compound has been proposed as efficient against HIV-1 protease with comparable biological activity to the existing ones; this drug candidate was evaluated using ADMET properties and Lipinski's rule. Molecular Docking performed on Wild Type, and Mutant Type HIV-1 proteases allowed the investigation of the interaction types displayed between the proteases and the ligands, Darunavir (DRV) and the new drug (ND). Molecular dynamics simulation was also used in order to investigate the complexes' stability allowing a comparative study on the performance of both ligands (DRV & ND). Our study suggested that the new molecule showed comparable results to that of darunavir and maybe used for further experimental studies. Our study may also be used as pipeline to search and design new potential inhibitors of HIV-1 proteases. [ABSTRACT FROM AUTHOR]

Gastroesophageal reflux disease (GERD) significantly impacts patient quality of life and is a major risk factor for the development of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Proton pump inhibitors (PPIs) are the standard-of-care for GERD and are among the most prescribed drugs in the world, but do not protect against nonacid components of reflux such as pepsin, or prevent reflux-associated carcinogenesis. We recently identified an HIV protease inhibitor amprenavir that inhibits pepsin and demonstrated the antireflux therapeutic potential of its prodrug fosamprenavir in a mouse model of laryngopharyngeal reflux. In this study, we assessed the capacity of amprenavir to protect against esophageal epithelial barrier disruption in vitro and related molecular events, E-cadherin cleavage, and matrix metalloproteinase induction, which are associated with GERD severity and esophageal cancer. Herein, weakly acidified pepsin (though not acid alone) caused cell dissociation accompanied by regulated intramembrane proteolysis of E-cadherin. Soluble E-cadherin responsive matrix metalloproteinases (MMPs) were transcriptionally upregulated 24 h post-treatment. Amprenavir, at serum concentrations achievable given the manufacturer-recommended dose of fosamprenavir, protected against pepsin-induced cell dissociation, E-cadherin cleavage, and MMP induction. These results support a potential therapeutic role for amprenavir in GERD recalcitrant to PPI therapy and for preventing GERD-associated neoplastic changes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plasmodium DDI1 protein is expressed in all major life cycle stages and is crucial for parasite development. • Infection of mice with DDI1 knock-down parasites confers immunity to subsequent infection. • Plasmodium DDI1 is associated with chromatin and DNA-protein crosslinks. • DDI1 knock-down parasites show enhanced susceptibility to HIV protease inhibitor lopinavir and antimalarial artemisinin. • Plasmodium DDI1 could be a therapeutic target for malaria control. DNA damage inducible 1 protein (DDI1) is involved in a variety of cellular processes including proteasomal degradation of specific proteins. All DDI1 proteins contain a ubiquitin-like (UBL) domain and a retroviral protease (RVP) domain. Some DDI1 proteins also contain a ubiquitin-associated (UBA) domain. The three domains confer distinct activities to DDI1 proteins. The presence of a RVP domain makes DDI1 a potential target of HIV protease inhibitors, which also block the development of malaria parasites. Hence, we investigated the DDI1 of malaria parasites to identify its roles during parasite development and potential as a therapeutic target. DDI1 proteins of Plasmodium and other apicomplexan parasites share the UBL-RVP domain architecture, and some also contain the UBA domain. Plasmodium DDI1 is expressed across all the major life cycle stages and is important for parasite survival, as conditional depletion of DDI1 protein in the mouse malaria parasite Plasmodium berghei and the human malaria parasite Plasmodium falciparum compromised parasite development. Infection of mice with DDI1 knock-down P. berghei was self-limiting and protected the recovered mice from subsequent infection with homologous as well as heterologous parasites, indicating the potential of DDI1 knock-down parasites as a whole organism vaccine. Plasmodium falciparum DDI1 (Pf DDI1) is associated with chromatin and DNA-protein crosslinks. Pf DDI1-depleted parasites accumulated DNA-protein crosslinks and showed enhanced susceptibility to DNA-damaging chemicals, indicating a role of Pf DDI1 in removal of DNA-protein crosslinks. Knock-down of Pf DDI1 increased susceptibility to the retroviral protease inhibitor lopinavir and antimalarial artemisinin, which suggests that simultaneous inhibition of DDI1 could potentiate antimalarial activity of these drugs. As DDI1 knock-down parasites confer protective immunity and it could be a target of HIV protease inhibitors, Plasmodium DDI1 is a potential therapeutic target for malaria control. [ABSTRACT FROM AUTHOR]

The 3C-like protease (also known as Mpro) plays a key role in SARS-CoV-2 replication and has similar substrates across mutant coronaviruses, making it an ideal drug target. We synthesized 19 thiazolidinedione derivatives via the Knoevenagel condensations and Mitsunobu reactions as potential 3C-like protease inhibitors. The activity of these inhibitors is screened in vitro by employing the enzymatic screening model of 3C-like protease using fluorescence resonance energy transfer. Dithiothreitol is included in the enzymatic reaction system to avoid non-specific enzymatic inhibition. Active inhibitors with diverse activity are found in this series of compounds, and two representative inhibitors with potent inhibitory activity are highlighted. [ABSTRACT FROM AUTHOR]

Introduction: The World Health Organization (WHO) has declared the novel coronavirus (COVID-2019) infection outbreak a global health emergency. Drug repurposing, which concerns the investigation of existing drugs for new therapeutic target indications, has emerged as a successful strategy for drug discovery due to the reduced costs and expedited approval procedures. Material and Methods: The crystal structure of a protein essential for virus replication has been filed in the Protein Data Bank recently. Based on this structure and existing experimental datasets for SARS-CoV2(COVID-19) we present results deriving from the virtual screening of a database of more than 1000 drugs in the DrugBank that have been approved by Food and Drug Administration (FDA). Results: Results showed that some of the known protease inhibitors currently used in HIV and Cancer infections might be helpful for the therapy of COVID-19 also. Results also showed that Levomefolic acid, or vitamin B9, is recommended therapy because of its oral sources and no side effects. Conclusion: Between all studied FDA-approved drug, VitaminB9 and Etoposide which used for HIV protease inhibitor, revealed strong interaction with protease binding pocket and placed well into the pocket even better than the lopinavir-ritonavir, and since this compound is FDA-approved and successfully passed various testing steps, therefor there is a hope that this drug, could be a potential drug to treating the COVID-19. [ABSTRACT FROM AUTHOR]

Background We describe trends in prevalence and identify factors associated with Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), syphilis, and Trichomonas vaginalis (TV) diagnosed in pregnancy among US people with human immunodeficiency virus (PWH) and evaluate associations of sexually transmitted infections (STIs) with preterm birth (PTB). Methods We included pregnant PWH enrolled in the Surveillance Monitoring for ART Toxicities dynamic cohort of the Pediatric HIV/AIDS Cohort Study network who delivered between 2010 and 2019. Multivariable log-binomial or Poisson generalized estimating equation models were used to estimate the association of calendar year with each STI, controlling for confounders; the association of demographic and clinical factors with each STI; and the association of each STI with PTB. Results The sample included 2241 pregnancies among 1821 PWH. Median age at delivery was 29.2 years; 71% of participants identified as Black or African American. STI prevalence was: CT 7.7%, NG 2.3%, syphilis 2.4%, and TV 14.5%; 30% had unknown TV status. There were no temporal changes in STI prevalence. Younger age and initial HIV viral load ≥400 copies/mL were associated with increased risk of CT, NG, and TV. Recreational substance use was a risk factor for NG, syphilis, and TV. No STI was associated with PTB. Conclusions Unlike nationwide trends, no changes in STI prevalence during the study period were observed. The large proportion with unknown TV status underscores the need for increased adherence to screening guidelines. STIs diagnosed during pregnancy in PWH were not associated with risk of PTB. [ABSTRACT FROM AUTHOR]

Studies on targeted antivirals for treatment of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the cause of the ongoing pandemic, are limited. PF‐07304814 (lufotrelvir) is the phosphate prodrug of PF‐00835231, a protease inhibitor targeting the 3C‐like protease of SARS‐CoV‐2. This phase 1 study evaluated the safety, tolerability, and pharmacokinetics (PK) of single ascending intravenous doses of lufotrelvir (continuous 24‐hour infusion of 50, 150, 500, or 700 mg) versus placebo in healthy volunteers (2 interleaving cohorts: 1, n = 8; 2, n = 7). Each dosing period was separated by a washout interval (≥5 days). Treatment‐emergent adverse events, PK, and biomarker concentrations were estimated from plasma/urine samples. Lufotrelvir was administered to 15 volunteers (mean [SD] age 39.7 [11.8] years). No serious adverse events, discontinuations, or deaths were reported. Mean maximum observed concentration of PF‐00835231 (active moiety; 97.0 ng/mL to 1288 ng/mL) were observed between median time to maximum concentration of 14 to 16 hours after the start of the lufotrelvir infusion. Near‐maximum plasma concentrations of PF‐00835231 were observed ≈6 hours after infusion start and sustained until infusion end. PF‐00835231 plasma concentrations declined rapidly after infusion end (mean terminal half‐life: 500 mg, 2.0 hours; 700 mg, 1.7 hours). Approximately 9%–11% of the dose was recovered in urine as PF‐00835231 across doses. A continuous, single‐dose, 24‐hour infusion of lufotrelvir (50–700 mg) was rapidly converted to PF‐00835231 (active moiety), with dose‐proportional PK exposures and no significant safety concerns. A daily, 24‐hour continuous infusion of 270 to 350 mg is expected to maintain PF‐00835231 concentration at steady state/above effective antiviral concentrations. Further studies exploring lufotrelvir efficacy in patients with coronavirus disease 2019 are ongoing. [ABSTRACT FROM AUTHOR]

Hepatitis C virus (HCV) is prevalent in people with mental health disorders, a priority population to diagnose and cure in order to achieve HCV elimination. This integrated analysis pooled data from 20 cohorts in seven countries to evaluate the real-world effectiveness of the pangenotypic direct-acting antiviral (DAA) sofosbuvir/velpatasvir (SOF/VEL) in people with mental health disorders. HCV-infected patients diagnosed with mental health disorders who were treated with SOF/VEL for 12 weeks without ribavirin as part of routine clinical practice were included. The primary outcome was sustained virological response (SVR) in the effectiveness population (EP), defined as patients with an available SVR assessment. Secondary outcomes were reasons for not achieving SVR, characteristics of patients with non-virological failures, adherence, and time from HCV RNA diagnosis to SOF/VEL treatment initiation. A total of 1209 patients were included; 142 did not achieve an SVR for non-virological reasons (n = 112; 83 lost to follow-up, 20 early treatment discontinuations) or unknown reasons (n = 30). Of the 1067 patients in the EP, 97.4% achieved SVR. SVR rates in the EP were ≥95% when stratified by type of mental health disorder and other complicating baseline characteristics, including active injection drug use and antipsychotic drug use. Of 461 patients with data available in the EP, only 2% had an adherence level < 90% and 1% had an adherence level < 80%; all achieved SVR. Patients with mental health disorders can be cured of HCV using a well-tolerated, pangenotypic, protease inhibitor-free SOF/VEL regimen. This DAA allows the implementation of a simple treatment algorithm, with minimal monitoring requirements and fewer interactions with central nervous system drugs compared with protease-inhibitor DAA regimens. [ABSTRACT FROM AUTHOR]

The human immunodeficiency virus type 1 (HIV-1) has continued to be a global concern. With the new HIV incidence, the emergence of multi-drug resistance and the untoward side effects of currently used anti-HIV drugs, there is an urgent need to discover more efficient anti-HIV drugs. Modern computational tools have played vital roles in facilitating the drug discovery process. This research focuses on a pharmacophore-based similarity search to screen 111,566,735 unique compounds in the PubChem database to discover novel HIV-1 protease inhibitors (PIs). We used an in silico approach involving a 3D-similarity search, physicochemical and ADMET evaluations, HIV protease-inhibitor prediction (IC50/percent inhibition), rigid receptor–molecular docking studies, binding free energy calculations and molecular dynamics (MD) simulations. The 10 FDA-approved HIV PIs (saquinavir, lopinavir, ritonavir, amprenavir, fosamprenavir, atazanavir, nelfinavir, darunavir, tipranavir and indinavir) were used as reference. The in silico analysis revealed that fourteen out of the twenty-eight selected optimized hit molecules were within the acceptable range of all the parameters investigated. The hit molecules demonstrated significant binding affinity to the HIV protease (PR) when compared to the reference drugs. The important amino acid residues involved in hydrogen bonding and п-п stacked interactions include ASP25, GLY27, ASP29, ASP30 and ILE50. These interactions help to stabilize the optimized hit molecules in the active binding site of the HIV-1 PR (PDB ID: 2Q5K). HPS/002 and HPS/004 have been found to be most promising in terms of IC50/percent inhibition (90.15%) of HIV-1 PR, in addition to their drug metabolism and safety profile. These hit candidates should be investigated further as possible HIV-1 PIs with improved efficacy and low toxicity through in vitro experiments and clinical trial investigations. [ABSTRACT FROM AUTHOR]

COVID-19 was caused by a novel coronavirus known as SARS-CoV-2. The COVID-19 disease outbreak has been avowed as a global pandemic by the World Health Organization at the end of March 2020. It leads to the global economic crash, resulting in the starvation of a large population belonging to economically backward countries. Hence, the development of an alternative medicine along with the vaccine is of the utmost importance for the management of COVID-19. Therefore, screening of several herbal leads was performed to explore their potential against SARS-CoV-2. Furthermore, viral main protease was selected as a key enzyme for performing the study. Various computational approaches, including molecular docking simulation, were used in the current study to find potential inhibitors of viral main protease from a library of 150 herbal leads. Toxicity and ADME prediction of selected molecules were also analysed by Osiris molecular property explorer software. Molecular dynamic simulation of the top 10 docked herbal leads was analysed for stability using 100 ns. Taraxerol (−10.17 kcal/mol), diosgenin (10.12 kcal/mol), amyrin (−9.56 kcal/mol), and asiaticoside (−9.54 kcal/mol) were among the top four herbal leads with the highest binding affinity with the main protease enzyme. Thus, taraxerol was found to be an effective drug candidate against the main protease enzyme for the management of COVID-19. Furthermore, its clinical effect and safety profile need to be established through an in vivo model. [ABSTRACT FROM AUTHOR]

The protease inhibitor, ritonavir, is a strong inhibitor of CYP 3A. The drug is used for management of the human immunovirus and is currently part of an oral antiviral drug combination (nirmatrelvir–ritonavir) for the early treatment of SARS‐2 COVID‐19‐positive patients aged 12 years and over who have recognized comorbidities. The CYP 3A enzyme system is responsible for clearance of numerous drugs used in anesthesia (e.g., alfentanil, fentanyl, methadone, rocuronium, bupivacaine, midazolam, ketamine). Ritonavir will have an impact on drug clearances that are dependent on ritonavir concentration, anesthesia drug intrinsic hepatic clearance, metabolic pathways, concentration‐response relationship, and route of administration. Drugs with a steep concentration‐response relationship (ketamine, midazolam, rocuronium) are mostly affected because small changes in concentration have major changes in effect response. An increase in midazolam concentration is observed after oral administration because CYP 3A in the gastrointestinal wall is inhibited, causing a large increase in relative bioavailability. Fentanyl infusion may be associated with a modest increase in plasma concentration and effect, but the large between subject variability of pharmacokinetic and pharmacodynamic concentration changes suggests it will have little impact on an individual patient, especially when used with adverse effect monitoring. It has been proposed that drugs that have no or only a small metabolic pathway involving the CYP 3A enzyme be used during anesthesia, for example, propofol, atracurium, remifentanil, and the volatile agents. That anesthesia approach denies children of drugs with considerable value. It is better that the inhibitory changes in clearance of these drugs are understood so that rational drug choices can be made to tailor drug use to the individual patient. Altered drug dose, anticipation of duration of effect, timing of administration, use of reversal agents and perioperative monitoring would better behoove children undergoing anesthesia. [ABSTRACT FROM AUTHOR]

Radiolabeled FSH1 peptides are potential specific probes for FSHR imaging. However, moderate uptakes and fast washout from the tumors may limit its widespread use. In this study, 68Ga labeled modified FSH1 analogs was prepared and the imaging properties were determined in the prostate cancer model with or without aprotinin. NOTA-MAL-FSH4 was synthesized and labeled with 68Ga. The pharmacokinetic profile of the peptide after co-administration with aprotinin was determined through metabolism analyses and microPET imaging. 68Ga-NOTA-MAL-FSH4 was successfully prepared. The IC50 value of displacement 68Ga-NOTA-MAL-FSH4 with FSH1 was 139.4 ± 1.16 nM. The PC-3 prostate tumor was visible after administration of the 68Ga labeled tracer. In vitro RP-HPLC analysis revealed that the average percentage of intact peptide in the plasma, liver and tumor was 8.30, 9.57 and 7.06% respectively. In presence of aprotinin, the amounts of intact peptide increased to 34.32%, 20.63% and 15.39% in the counterparts respectively. MicroPET imaging showed that the uptakes of PC-3 tumors at 60mins after co-administration of 100 μg, 200 μg or 400 μg enzyme inhibitors were 2.91 ± 0.21%ID/g, 3.89 ± 0.16%ID/g and 9.21 ± 0.22%ID/g respectively. With the aid of a serine protease inhibitor, the performance of the 68Ga labeled peptide was optimized, which may benefit further clinical application. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF) coatings on cells enhance viability in cytotoxic environments. Here, we show how protective multi-layered MOF bio-composite shells on a model cell system (yeast) enhance the proliferation of living cells exposed to hostile protease-rich environments via the dissolution of the shells and release of a protease inhibitor (antitrypsin). [ABSTRACT FROM AUTHOR]

The replication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is mediated by its main protease (Mpro), which is a plausible therapeutic target for coronavirus disease 2019 (COVID-19). Although numerous in silico studies reported the potential inhibitory effects of natural products including cannabis and cannabinoids on SARS-CoV-2 Mpro, their anti-Mpro activities are not well validated by biological experimental data. Herein, a library of minor cannabinoids belonging to several chemotypes including tetrahydrocannabinols, cannabidiols, cannabigerols, cannabichromenes, cannabinodiols, cannabicyclols, cannabinols, and cannabitriols was evaluated for their anti-Mpro activity using a biochemical assay. Additionally, the binding affinities and molecular interactions between the active cannabinoids and the Mpro protein were studied by a biophysical technique (surface plasmon resonance; SPR) and molecular docking, respectively. Cannabinoids tetrahydrocannabutol and cannabigerolic acid were the most active Mpro inhibitors (IC50 = 3.62 and 14.40 μM, respectively) and cannabigerolic acid had a binding affinity K D = 2.16 × 10 − 4 M). A preliminary structure and activity relationship study revealed that the anti- M pro effects of cannabinoids were influenced by the decarboxylation of cannabinoids and the length of cannabinoids' alkyl side chain. Findings from the biochemical, biophysical, and computational assays support the growing evidence of cannabinoids' inhibitory effects on SARS-CoV-2 Mpro. [ABSTRACT FROM AUTHOR]

Background: Data on the effectiveness and safety of dolutegravir-based antiretroviral therapy (ART) for human immunodeficiency virus type 1 (HIV-1) infection in pregnancy as compared with other ART regimens commonly used in the United States and Europe, particularly when initiated before conception, are limited.Methods: We conducted a study involving pregnancies in persons with HIV-1 infection in the Pediatric HIV/AIDS Cohort Study whose initial ART in pregnancy included dolutegravir, atazanavir-ritonavir, darunavir-ritonavir, oral rilpivirine, raltegravir, or elvitegravir-cobicistat. Viral suppression at delivery and the risks of infants being born preterm, having low birth weight, and being small for gestational age were compared between each non-dolutegravir-based ART regimen and dolutegravir-based ART. Supplementary analyses that included participants in the Swiss Mother and Child HIV Cohort Study were conducted to improve the precision of our results.Results: Of the pregnancies in the study, 120 were in participants who received dolutegravir, 464 in those who received atazanavir-ritonavir, 185 in those who received darunavir-ritonavir, 243 in those who received rilpivirine, 86 in those who received raltegravir, and 159 in those who received elvitegravir-cobicistat. The median age at conception was 29 years; 51% of the pregnancies were in participants who started ART before conception. Viral suppression was present at delivery in 96.7% of the pregnancies in participants who received dolutegravir; corresponding percentages were 84.0% for atazanavir-ritonavir, 89.2% for raltegravir, and 89.8% for elvitegravir-cobicistat (adjusted risk differences vs. dolutegravir, -13.0 percentage points [95% confidence interval {CI}, -17.0 to -6.1], -17.0 percentage points [95% CI, -27.0 to -2.4], and -7.0 percentage points [95% CI, -13.3 to -0.0], respectively). The observed risks of preterm birth were 13.6 to 17.6%. Adjusted risks of infants being born preterm, having low birth weight, or being small for gestational age did not differ substantially between non-dolutegravir-based ART and dolutegravir. Results of supplementary analyses were similar.Conclusions: Atazanavir-ritonavir and raltegravir were associated with less frequent viral suppression at delivery than dolutegravir. No clear differences in adverse birth outcomes were observed with dolutegravir-based ART as compared with non-dolutegravir-based ART, although samples were small. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others.). [ABSTRACT FROM AUTHOR]

Objective: To compare the incidence of hypertension in people living with HIV receiving integrase strand transfer inhibitor (INSTI)‐based antiretroviral therapy (ART) versus non‐nucleoside reverse transcriptase inhibitors (NNRTIs) or boosted protease inhibitors (PIs) in the RESPOND consortium of HIV cohorts. Methods: Eligible people with HIV were aged ≥18 years who initiated a new three‐drug ART regimen for the first time (baseline), did not have hypertension, and had at least two follow‐up blood pressure (BP) measurements. Hypertension was defined as two consecutive systolic BP measurements ≥140 mmHg and/or diastolic BP ≥90 mmHg or initiation of antihypertensives. Multivariable Poisson regression was used to determine adjusted incidence rate ratios (aIRRs) of hypertension, overall and in those who were ART naïve or experienced at baseline. Results: Overall, 4606 people living with HIV were eligible (INSTIs 3164, NNRTIs 807, PIs 635). The median baseline systolic BP, diastolic BP, and age were 120 (interquartile range [IQR] 113–130) mmHg, 78 (70–82) mmHg, and 43 (34–50) years, respectively. Over 8380.4 person‐years (median follow‐up 1.5 [IQR 1.0–2.7] years), 1058 (23.0%) participants developed hypertension (incidence rate 126.2/1000 person‐years, 95% confidence interval [CI] 118.9–134.1). Participants receiving INSTIs had a higher incidence of hypertension than those receiving NNRTIs (aIRR 1.76; 95% CI 1.47–2.11), whereas the incidence was no different in those receiving PIs (aIRR 1.07; 95% CI 0.89–1.29). The results were similar when the analysis was stratified by ART status at baseline. Conclusion: Although unmeasured confounding and channelling bias cannot be excluded, INSTIs were associated with a higher incidence of hypertension than were NNRTIs, but rates were similar to those of PIs overall, in ART‐naïve and ART‐experienced participants within RESPOND. [ABSTRACT FROM AUTHOR]

To evaluate the inhibitory effect of a novel mussel-inspired monomer (N -(3,4-dihydroxyphenethyl)methacrylamide (DMA) on the soluble and matrix-bound proteases. The inhibitory effect of DMA (0, 1, 5, and 10 mM) and 1 mM chlorhexidine (CHX) dissolved in 50% ethanol/water on soluble recombinant human matrix metalloproteinases (rhMMP-2, −8, and −9), as well as cysteine cathepsins (B and K) were evaluated using both fluorometric assay kits and molecular docking. The effect of CHX and DMA on matrix-bound proteases was examined by in situ zymography, and the fluorescence intensity and relative area were calculated by Image J software. All data obtained were analyzed by one-way ANOVA followed by Tukey test (α = 0.05). The anti-proteolytic ability of DMA increased in a dose-dependent manner except that of rhMMP-9. Inhibitory effect of 1 mM DMA against rhMMP-2, − 8, − 9, as well as cathepsin B and K was all significantly lower than 1 mM CHX (p < 0.05). The molecular docking analysis was in good agreement with the experimental results, that the binding energy of DMA was lower than CHX for all proteases. In situ zymography revealed that all DMA- and CHX-treated groups significantly inactivated the matrix-bound proteases, with a dramatic reduction of the fluorescence intensity and relative area compared with the control group (p < 0.05). Under the prerequisite condition that the overall inhibitory performance on matrix-bound proteases was comparable by DMA and CHX, the more selective property of DMA could avoid inducing potential negative effects by suppressing MMP-9 when applied in dental treatment compared with CHX. [Display omitted] • Anti-proteolytic ability of DMA increased in a dose-dependent manner except MMP-9. • The binding mechanism of DMA toward proteases was simulated by molecular docking. • CHX was a broad-spectrum inhibitor, while DMA selectively inhibited MMP-2 and − 8. • DMA manifested comparable inhibitory effect as CHX on matrix-bound proteases. [ABSTRACT FROM AUTHOR]

Studies have previously demonstrated the importance of serine proteases in Leishmania. A well-known serine protease inhibitor, TPCK, was used in the present study to evaluate its in vitro and in vivo antileishmanial effects and determine its mechanism of action. Despite slight toxicity against mammalian cells (CC50 = 138.8 µM), TPCK was selective for the parasite due to significant activity against L. amazonensis and L. infantum promastigote forms (IC50 = 14.6 and 31.7 µM for L. amazonensis PH8 and Josefa strains, respectively, and 11.3 µM for L. infantum) and intracellular amastigotes (IC50 values = 14.2 and 16.6 µM for PH8 and Josefa strains, respectively, and 21.7 µM for L. infantum). Leishmania parasites treated with TPCK presented mitochondrial alterations, oxidative stress, modifications in lipid content, flagellar alterations, and cytoplasmic vacuoles, all of which are factors that could be considered as contributing to the death of the parasites. Furthermore, BALB/c mice infected with L. amazonensis and treated with TPCK had a reduction in lesion size and parasite loads in the footpad and spleen. In BALB/c mice infected with L. infantum, TPCK also caused a reduction in the parasite loads in the liver and spleen. Therefore, we highlight the antileishmanial effect of the assessed serine protease inhibitor, proposing a potential therapeutic target in Leishmania as well as a possible new alternative treatment for leishmaniasis. [ABSTRACT FROM AUTHOR]

Background: Tenofovir disoproxil fumarate, particularly when given with a ritonavir-boosted PI, reduces bone mineral density (BMD) and increases bone turnover markers (BTMs). Ritonavir-boosted atazanavir plus lamivudine is a feasible simplified option. We evaluated whether switching from a triple ritonavir-boosted PI plus tenofovir disoproxil fumarate to a two-drug regimen of lamivudine plus ritonavir-boosted atazanavir would improve BMD.Methods: Single-arm pilot study. Virologically suppressed patients on tenofovir disoproxil fumarate plus lamivudine or emtricitabine plus ritonavir-boosted PI with low BMD, without previous resistance mutations and/or virological failure to study drugs were switched to 100/300 mg of ritonavir-boosted atazanavir plus 300 mg of lamivudine once daily. The primary endpoint was BMD change by DXA at Week 48.Results: There were 31 patients, 4 (13%) female, and median age was 40 years. Seven participants (22.5%) had osteoporosis. At 48 weeks, mean (SD) changes in spine and hip BMD were +0.01 (0.03) (P = 0.0239) and +0.013 (0.03) g/cm2 (P = 0.0046), respectively. Mean (SD) T-score changes were +0.1 (0.23) (P = 0.0089) and +0.25 (0.76) (P = 0.0197), respectively. N-telopeptide and urine tenofovir disoproxil fumarate toxicity markers showed significant improvements. One participant withdrew from the study and two were lost to follow-up. There were no virological failures, or serious or grade 3-4 adverse events.Conclusions: Switching from a tenofovir disoproxil fumarate plus ritonavir-boosted PI triple therapy to a lamivudine plus ritonavir-boosted atazanavir two-drug regimen in virologically suppressed HIV-infected adults with low BMD was safe, increased low BMD and reduced plasma markers of bone turnover and urine markers of tenofovir disoproxil fumarate toxicity over 48 weeks. [ABSTRACT FROM AUTHOR]

Amongst our patients, the addition of Kaletra has led to a partial response in half of the cases, and 5 of the 12 patients achieved stable disease who were otherwise progressing on CFZ-based treatment. As per IMWG criteria, six (50%) of the patients achieved a partial response (PR) to treatment, five patients (42%) achieved stable disease (SD), whilst one had disease progression (PD) despite therapy. Treatment failure resulted from progression for 6 patients (50%), treatment cessation for two patients (17%), and death for two patients (17%). [Extracted from the article]

Saquinavir was the first protease inhibitor developed for HIV therapy, and it changed the standard of treatment for this disease to a combination of drugs that ultimately led to increased survival of this otherwise deadly condition. Inhibiting the HIV protease impedes the virus from maturing and replicating. With this in mind, since the start of the COVID-19 outbreak, the research for already approved drugs (mainly antivirals) to repurpose for treatment of this disease has increased. Among the drugs tested, saquinavir showed promise in silico and in vitro in the inhibition of the SARS-CoV-2 main protease (3CLpro). Another field for saquinavir repurposing has been in anticancer treatment, in which it has shown effects in vitro and in vivo in several types of cancer, from Kaposi carcinoma to neuroblastoma, demonstrating cytotoxicity, apoptosis, inhibition of cell invasion, and improvement of radiosensibility of cancer cells. Despite the lack of follow-up in clinical trials for cancer use, there has been a renewed interest in this drug recently due to COVID-19, which shows similar pharmacological pathways and has developed superior in silico models that can be translated to oncologic research. This could help further testing and future approval of saquinavir repurposing for cancer treatment. [ABSTRACT FROM AUTHOR]

Brensocatib, an investigational first‐in‐class, small‐molecule, orally bioavailable, selective, and reversible dipeptidyl peptidase 1 inhibitor that blocks activation of neutrophil serine proteases, is currently under clinical development for the treatment of bronchiectasis and other chronic inflammatory diseases. In a 2‐part phase 1 study, the safety, tolerability, and pharmacokinetics of brensocatib were evaluated in healthy Japanese and White adults. In part A, participants received single and multiple once‐daily doses of brensocatib (10, 25, or 40 mg) or placebo after an overnight fast. In part B, participants received a single oral dose of brensocatib 40 mg on days 1 and 8, with or without food in a crossover fashion. Following a single dose and at steady state, brensocatib exposure was dose dependent, with low to moderate interindividual variability; systemic exposure between Japanese and White participants was similar. Elimination half‐life of brensocatib ranged from 22 to 28 hours, resulting in ≈2‐fold accumulation in maximum plasma concentration and area under the plasma concentration–time curve at steady state. In both ethnic groups, the presence of food slightly delayed brensocatib absorption with time to maximum plasma concentration increased by 0.7 to 1.7 hours, but it had no significant effect on brensocatib exposure (maximum plasma concentration and area under the plasma concentration–time curve). Brensocatib was well tolerated in Japanese and White participants. The most frequently reported treatment‐emergent adverse events were headache and skin exfoliation. No clinically significant vital signs, laboratory abnormalities, or evidence of renal toxicity were observed. The results from this study demonstrate that brensocatib can be administered with or without food and that dose adjustment is unnecessary for Japanese patients when receiving brensocatib treatment. [ABSTRACT FROM AUTHOR]

This article, titled "Retraction: Human Epididymis Protein-4 (HE-4): A Novel Cross-Class Protease Inhibitor," was retracted by the editors of PLoS ONE due to concerns raised about the integrity of the images in Figures 1 and 7. The concerns centered around similarities between certain bands and markers in the figures, despite representing different experimental conditions. The corresponding author acknowledged the similarities but disputed that the indicated areas were identical. Alternative experimental results and images provided did not resolve the concerns. Some authors disagreed with the retraction and stood by the findings, while others did not respond or could not be reached. [Extracted from the article]

The resistance of HIV-1 protease (PR) mutations seriously affects the efficiency of current drugs in the clinical treatment of AIDS. Therefore, it is important to understand the resistance mechanism of mutated residues for the development of PR inhibitors. In this work, the mechanism of G48M mutant PR to inhibitors Saquinavir and Atazanavir was studied by using molecular dynamics simulation combined with free energy prediction. The analysis results showed that, compared with the WT PR, the distance of the flap tip from the protease catalytic binding site and the dihedral angles in the flap regions in the mutant type complexes was changed. These changes resulted in a significant reduction in the occupancy of most of the hydrogen bonds in the mutant complex and the interaction energy of key residues with the inhibitor, which is the main reason for the resistance of the mutation to these inhibitors. This study can provide important guidance for the design of effective inhibitors against HIV-1 PR. [ABSTRACT FROM AUTHOR]

The action of proteases can be controlled by several mechanisms, including regulation through gene expression; post-translational modifications, such as glycosylation; zymogen activation; targeting specific compartments, such as lysosomes and mitochondria; and blocking proteolysis using endogenous inhibitors. Protease inhibitors are important molecules to be explored for the control of proteolytic processes in organisms because of their ability to act on several proteases. In this context, plants synthesize numerous proteins that contribute to protection against attacks by microorganisms (fungi and bacteria) and/or invertebrates (insects and nematodes) through the inhibition of proteases in these organisms. These proteins are widely distributed in the plant kingdom, and are present in higher concentrations in legume seeds (compared to other organs and other botanical families), motivating studies on their inhibitory effects in various organisms, including humans. In most cases, the biological roles of these proteins have been assigned based mostly on their in vitro action, as is the case with enzyme inhibitors. This review highlights the structural evolution, function, and wide variety of effects of plant Kunitz protease inhibitors, and their potential for pharmaceutical application based on their interactions with different proteases. [ABSTRACT FROM AUTHOR]

Although several proteasome subunits have been shown to bind ubiquitin (Ub) chains, many ubiquitylated substrates also associate with 26S proteasomes via "shuttling factors." Unlike the well-studied yeast shuttling factors Rad23 and Dsk2, vertebrate homologs Ddi2 and Ddi1 lack a Ub-associated domain; therefore, it is unclear how they bind Ub. Here, we show that deletion of Ddi2 leads to the accumulation of Ub conjugates with K11/K48 branched chains. We found using affinity copurifications that Ddi2 binds Ub conjugates through its Ub-like domain, which is also required for Ddi2 binding to proteasomes. Furthermore, in cell extracts, adding Ub conjugates increased the amount of Ddi2 associated with proteasomes, and adding Ddi2 increased the binding of Ub conjugates to purified proteasomes. In addition, Ddi2 also contains a retroviral protease domain with undefined cellular roles. We show that blocking the endoprotease activity of Ddi2 either genetically or with the HIV protease inhibitor nelfinavir increased its binding to Ub conjugates but decreased its binding to proteasomes and reduced subsequent protein degradation by proteasomes leading to further accumulation of Ub conjugates. Finally, nelfinavir treatment required Ddi2 to induce the unfolded protein response. Thus, Ddi2 appears to function as a shuttling factor in endoplasmic reticulum-associated protein degradation and delivers K11/K48-ubiquitylated proteins to the proteasome. We conclude that the protease activity of Ddi2 influences this shuttling factor activity, promotes protein turnover, and helps prevent endoplasmic reticulum stress, which may explain nelfinavir's ability to enhance cell killing by proteasome inhibitors. [ABSTRACT FROM AUTHOR]

This paper describes the structure-based design and synthesis of two novel square-planar trans-N2O2 Cu(II) complexes [Cu(L1)2] (1) and [Cu(L2)2] (2) of 2-((Z)-(4-methoxyphenylimino)methyl)-4,6-dichlorophenol (L1H) and 2-((Z)-(2,4-dibromophenylimino)methyl)-4-bromophenol (L2H) as potential inhibitors against the main protease of the SARS-CoV-2 and HIV viruses. Copper complexes (1) and (2) crystallize in a monoclinic crystal system with P21/n and P21/c space groups, respectively [a = 12.4630(12) Å, b = 9.2765(10) Å, c = 12.6425(13) Å, α = 90°, β = 111.863°, γ = 90° and Z = 2 for [Cu(L1)2] (1); a = 10.1185(13) Å, b = 10.9809(12) Å, c = 12.5803(13) Å, α = 90°, β = 103.795°, γ = 90°, and Z = 2 for [Cu(L2)2] (2)]. Single crystal X-ray diffraction studies revealed that both complexes exhibit square-planar geometry (τ = 0). Quantum computational calculations were used for the structure–property relationship. Detailed structural and non-covalent supramolecular interactions in the complexes were investigated by single crystal structure analysis and computational approaches. Hirshfeld surface and 2D fingerprint plots were explored in the crystal structure of the complexes. The strength of the interaction and 3D topology of the crystal packing are visualized through an energy framework. Further, inspired by recent developments to find a structure-based drug design for inhibitors of the SARS-CoV-2 main protease, molecular docking of the copper complexes with the SARS-CoV-2 main protease for COVID-19 was performed. The X-ray crystallographic structures of the main protease of the SARS-CoV-2 virus (PDB ID: 6XBG) and HIV virus (PDB ID: 1JLE and 1UUD) were retrieved from the protein data bank and used as receptor proteins. The molecular docking calculations of complexes (1) and (2) with SARS-CoV-2 virus revealed binding affinities of −9.8 kcal mol−1 and −9.4 kcal mol−1 with inhibition constants of 2.912 μM and 2.813 μM, respectively, at the inhibition binding site of the receptor protein. Besides this, molecular docking against HIV-1 reverse transcriptase (PDB ID: 1JLE) and HIV-1 TAR RNA (PDB ID: 1UUD) were also studied. The molecular docking results also showed that copper complexes with HIV-1 and HIV-1 RNA exhibited good binding affinities and inhibition constants at the binding site of the receptor protein. It was observed that the binding affinities of the copper complexes towards SARS-CoV-2 were comparatively higher than towards the HIV virus. Overall, an in silico molecular docking study suggests the potential role of copper complexes as antivirus drug candidates targeting the SARS-CoV-2 Mpro and HIV protease inhibitors. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we report an iridium‐catalyzed asymmetric hydrogenation of hydantoin and thiazolidinedione derived exocyclic alkenes using our developed BiphPHOX as a ligand. The transformation shows good functional group tolerance, and gives the hydrogenated products with excellent yields (up to 99%) and enantioselectivities (up to 98% ee). A gram‐scale reaction was also carried out, and provided the hydrogenated product in excellent yield with no erosion in enantioselectivity. Finally, the transformation of the hydrogenated product provided an efficient approach for the synthesis of the intermediate of a HIV protease inhibitor. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome 2 (SARS-CoV-2), has been one of the most devastating pandemics of recent times. The lack of potent novel antivirals had led to global health crises; however, emergence and approval of potent inhibitors of the viral main protease (Mpro), such as Pfizer's newly approved nirmatrelvir, offers hope not only in the therapeutic front but also in the context of prophylaxis against the infection. By their nature, RNA viruses including human immunodeficiency virus (HIV) have inherently high mutation rates, and lessons learnt from previous and currently ongoing pandemics have taught us that these viruses can easily escape selection pressure through mutation of vital target amino acid residues in monotherapeutic settings. In this paper, we review nirmatrelvir and its binding to SARS-CoV-2 Mpro and draw a comparison to inhibitors of HIV protease that were rendered obsolete by emergence of resistance mutations, emphasizing potential pitfalls in the design of inhibitors that may be of important relevance to the long-term use of novel inhibitors against SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Blumea balsamifera (L.) DC is a medicinal plant widely used against various ailments throughout Asian and African cultures. The reported efficacy of B. balsamifera and its phytochemicals against respiratory disorders suggests that it can be a potential therapeutic against the coronavirus disease 2019 (COVID-19), which is also a respiratory disease. This potential was demonstrated through an in silico assessment utilizing B. balsamifera phytochemicals and targeting the severe acute respiratory syndrome-coronavirus-2 main protease (SARS-CoV-2 Mpro), an enzyme that plays an important role in the infection process by SARS-CoV-2. The general strategy implemented was termed phytochemical mining in tandem with virtual screening (PM-VS). Data gathering of B. balsamifera phytochemicals reported in the literature was first conducted (PM stage) followed by VS through automated molecular docking of multiple ligands. The present study obtained the most comprehensive phytochemical record and organization of B. balsamifera phytochemicals (a total of 331). Surprisingly, 113 of the unique phytochemicals were promising SARS-CoV-2 Mpro inhibitors, of which 12 were re-discovered antiviral drugs from the plant. The promising inhibitors also reveal interesting in silico drug absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. Further analysis of the promising phytochemicals and their interactions with SARS-CoV-2 Mpro hints at the phenylpropanoid moiety (Ph-C3-) as a potential pharmacophore of the target enzyme. This study illustrated the utility of PM-VS in the preliminary stages of drug discovery and development; however, further studies (e.g. exhaustive VS and definitive "ex silico" experiments) are needed to confirm the present finding. [ABSTRACT FROM AUTHOR]