The Impact of Contemporary Antiretroviral Drugs on Atherosclerosis and Its Complications in People Living With HIV: A Systematic Review.

With the advent of modern antiretroviral therapy (ART), human immunodeficiency virus (HIV) infection has been modified into a chronic manageable condition, prolonging the lifespan of people living with HIV (PLHIV). This has resulted in an increased non-AIDS-related morbidity in the HIV-infected population. Our aim is to study the role of contemporary ART in tackling the risk of atherosclerosis and cardiovascular disease (CVD) in PLHIV. We searched through the databases of PubMed, PubMed Central, and Cochrane Library for pertinent articles using the medical subject headings (MeSH) "HIV infection", "Atherosclerosis", and "Antiretroviral agents". The articles published in the past five years were retrieved, screened for relevance, and assessed for quality before being included in the review. This review was performed following the PRISMA 2020 guidelines. The results indicate that the incidence of dyslipidemia with integrase strand transfer inhibitors (INSTIs) is greater than with non-nucleoside reverse transcriptase inhibitors (NNRTIs) and lesser than with protease inhibitors (PIs). INSTIs are indispensably associated with weight gain and obesity. High triglyceride (TG) and oxidized low-density lipoproteins to low-density lipoproteins (oxLDL/LDL) ratio levels and low high-density lipoprotein (HDL) levels are seen in patients taking PIs. A higher incidence of hypertension and metabolic syndrome (MetS) was noticed with INSTIs compared to NNRTIs. PI intake for >5 years increases the risk of subclinical atherosclerosis. Increased risk of myocardial infarction with INSTIs was observed in a study, while another study reported decreased risk. HIV infection independently increases the risk for atherosclerosis and CVD. Although contemporary ART decreases this enhanced risk, it inherently increases the risk for abnormal lipid profile, MetS, weight gain, and obesity. Further research into the risk of atherosclerosis and CVD with newer ART drugs is essential for decoding the underlying mechanisms and preventing adverse cardiac outcomes in PLHIV.

Lopinavir and ritonavir act synergistically with azoles against Candida auris in vitro and in a mouse model of disseminated candidiasis.

INTRODUCTION AND OBJECTIVES: The emergence of Candida auris has created a global health challenge. Azole antifungals are the most affected antifungal class because of the extraordinary capability of C. auris to develop resistance against these drugs. Here, we used a combinatorial therapeutic approach to sensitize C. auris to azole antifungals. METHODS AND RESULTS: We have demonstrated the capability of the HIV protease inhibitors lopinavir and ritonavir, at clinically relevant concentrations, to be used with azole antifungals to treat C. auris infections both in vitro and in vivo. Both lopinavir and ritonavir exhibited potent synergistic interactions with the azole antifungals, particularly with itraconazole against 24/24 (100%) and 31/34 (91%) of tested C. auris isolates, respectively. Furthermore, ritonavir significantly interfered with the fungal efflux pump, resulting in a significant increase in Nile red fluorescence by 44%. In a mouse model of C. auris systemic infection, ritonavir boosted the activity of lopinavir to work synergistically with fluconazole and itraconazole and significantly reduced the kidney fungal burden by a 1.2 log (∼94%) and 1.6 log (∼97%) CFU, respectively. CONCLUSION: Our results urge further comprehensive assessment of azoles and HIV protease inhibitors as a novel drug regimen for the treatment of serious invasive C. auris infections.

AI-Aided Search for New HIV-1 Protease Ligands.

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.

Atazanavir Resensitizes Candida auris to Azoles.

Candida auris represents an urgent health threat. Here, we identified atazanavir as a potent drug capable of resensitizing C. auris clinical isolates to the activity of azole antifungals. Atazanavir was able to significantly inhibit the efflux pumps, glucose transport, and ATP synthesis of all tested isolates of C. auris. In addition, the combination of itraconazole with atazanavir-ritonavir significantly reduced the burden of azole-resistant C. auris in murine kidneys by 1.3 log10 (95%), compared to itraconazole alone.

A Systematic Review Exploring the Effect of Human Immunodeficiency Virus on Cardiac Diseases.

Human immunodeficiency virus (HIV) primarily affects the immune systems, which, if progressed, will lead to acquired immunodeficiency syndrome (AIDS). Currently, there is no effective cure for the disease, and patients are affected lifelong, but there are antiretroviral medications that can control the disease's symptoms and progression. In addition, taking precautions during sexual contact, especially in the male homosexual population, while handling the patient's bodily fluids such as blood and saliva, and during childbirth by an infected mother is necessary to prevent the transmission of the virus. We used 15 studies, including systematic reviews and meta-analyses, observation studies, randomized clinical trials, and comprehensive reviews, to determine how HIV interferes with heart disease, increasing morbidity and mortality. We have used specific inclusion and exclusion criteria, focusing on specified age groups within a particular timeline. Some of the included studies found that many side effects from antiretroviral drugs can impact heart conditions, along with HIV, while others did not show a strong correlation between HIV and some heart diseases. In conclusion, after reviewing the literature, the results are inconclusive. More extensive trials focusing on the impact HIV has on heart disease are required to establish a strong correlation between HIV and heart disease to prevent morbidity and mortality.

Discovery of Novel HIV Protease Inhibitors Using Modern Computational Techniques.

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.

Switching from a Non-Protease inhibitor-Based Regimen To the Fixed Dose Combination of Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide in Clinical Practice.

Background: The primary objective of this study was to estimate the proportion of people living with HIV (PLWH) who switched from a non-protease inhibitor (PI)-based regimen [integrase strand transfer inhibitor (InSTI)-based or non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen] to darunavir, cobicistat, emtricitabine, tenofovir alafenamide (D/C/F/TAF). Methods: This was a retrospective study on PLWH treated with a non-PI regimen in January 2017, who switched to D/C/F/TAF or to another antiretroviral therapy (ART) within November 2019. Follow-up was from the start date of D/C/F/TAF until the last available visit or discontinuation for any reason of this regimen. Virological failure (VF) was defined as 2 consecutive HIV-RNA values >50 copies/mL. Characteristics were reported as median (interquartile range) or frequency (%). A univariate Poisson regression model was used to measure the incidence rate of switch to D/C/F/TAF. Changes in laboratory parameters during D/C/F/TAF were assessed by univariate mixed linear models. Results: Overall, 3076 PLWH were included; 83% were male, median age at ART switch was 50 (42-56) years and median time on ART was 5.2 (0.3-13.0) years. PLWH had a median follow-up of 4.76 (3.70-6.38) years; during 17,099 person-years of follow-up (PYFU), 423/3076 (14%) participants discontinued the non-PI-based regimen and 106/423 (25%) switched to D/C/F/TAF, with an overall incidence rate of switch to D/C/F/TAF of 6.2 per 1000-PYFU (95% CI: 5.0-7.4). Among PLWH who switched to D/C/F/TAF, the ongoing regimen was based on NNRTIs in 37 (35%) and on InSTIs in 69 (65%). Main reasons leading to switch to D/C/F/TAF included neuropsychiatric adverse events (37%), VF (26%) and Kaposi sarcoma progression (5%). Conclusion: In the last years, a non-negligible proportion of patients on an NNRTI- or an InSTI-based regimen switched to D/C/F/TAF.

HIV protease inhibitor nelfinavir is a potent drug candidate against echinococcosis by targeting Ddi1-like protein.

BACKGROUND: Alveolar echinococcosis (AE), which is caused by larval Echinococcus multilocularis, is one of the world's most dangerous neglected diseases. Currently, no fully effective treatments are available to cure this disease. METHODS: In vitro protoscolicidal assay along with in vivo murine models was applied in repurposing drugs against AE. Genome-wide identification and homology-based modeling were used for predicting drug targets. RNAi, enzyme assay, and RNA-Seq analyses were utilized for investigating the roles in parasite survival and validations for the drug target. FINDINGS: We identified nelfinavir as the most effective HIV protease inhibitor against larval E. multilocularis. Once-daily oral administration of nelfinavir for 28 days resulted in a remarkable reduction in parasite infection in either immune-competent or immunocompromised mice. E. multilocularis DNA damage-inducible 1 protein (EmuDdi1) is predicted as a target candidate for nelfinavir. We proved that EmuDdi1 is essential for parasite survival and protein excretion and acts as a functionally active protease for this helminth. We found nelfinavir is able to inhibit the proteolytic activity of recombinant EmuDdi1 and block the EmuDdi1-related pathways for protein export. With other evidence of drug efficacy comparison, our results suggest that inhibition of EmuDdi1 is a mechanism by which this HIV proteinase inhibitor mediates its antiparasitic action on echinococcosis. INTERPRETATION: This study demonstrates that nelfinavir is a promising candidate for treating echinococcosis. This drug repurposing study proves that the widely prescribed drug for AIDS treatment is potent in combating E. multilocularis infection and thus provides valuable insights into the development of single-drug therapy for highly prevalent co-infection between HIV and helminth diseases. FUNDING: This work was supported by the National Natural Science Foundation of China (31802179), the Natural Science Foundation of Gansu Province, China (No. 21JR7RA027), and the State Key Laboratory of Veterinary Etiological Biology (No. SKLVEB2021YQRC01).

Molecular Mechanisms of HIV Protease Inhibitors Against HPV-Associated Cervical Cancer: Restoration of TP53 Tumour Suppressor Activities.

Cervical cancer is a Human Papilloma virus-related disease, which is on the rise in a number of countries, globally. Two essential oncogenes, E6 and E7, drive cell transformation and cancer development. These two oncoproteins target two of the most important tumour suppressors, p53 and pRB, for degradation through the ubiquitin ligase pathway, thus, blocking apoptosis activation and deregulation of cell cycle. This pathway can be exploited for anticancer therapeutic interventions, and Human Immunodeficiency Virus Protease Inhibitors (HIV-PIs) have attracted a lot of attention for this anticancer drug development. HIV-PIs have proven effective in treating HPV-positive cervical cancers and shown to restore impaired or deregulated p53 in HPV-associated cervical cancers by inhibiting the 26S proteasome. This review will evaluate the role players, such as HPV oncoproteins involved cervical cancer development and how they are targeted in HIV protease inhibitors-induced p53 restoration in cervical cancer. This review also covers the therapeutic potential of HIV protease inhibitors and molecular mechanisms behind the HIV protease inhibitors-induced p53-dependent anticancer activities against cervical cancer.

Dyspnea and Pulmonary Function Among Participants in the Multicenter AIDS Cohort Study Using Protease Inhibitors: A Cross-Sectional Study.

People living with HIV (PLWH) have a higher prevalence of respiratory symptoms than people without human immunodeficiency virus (HIV). Antiretroviral therapy has been associated with worsened airflow limitation. This cross-sectional study assessed respiratory health impairment among PLWH and its association with protease inhibitor use using data from Multicenter AIDS Cohort Study visits between April 1, 2017 and March 31, 2018. Participants completed the St. George's Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) dyspnea scale, spirometry, and diffusion capacity measurement. Visit data were compared among PI users, non-PI users, and men without HIV. Binary and ordinal logistic models were used to determine the associations between HIV status, PI use, and covariates with primary outcomes of dichotomized SGRQ and mMRC dyspnea scores. Of PI users, 57/177 (32.2%) self-reported pulmonary disease compared with 132/501 (26.4%) of non-PI users and 105/547 (19.2%) men without HIV. Of PI users, 77/177 (45.3%) had SGRQ scores ≥10, while 171/501 (34.7%) of non-PI users and 162/549 (29.9%) of people living without HIV had SGRQ scores ≥10 (p = .001). Adjusted models found an association between PI use and SGRQ score ≥10 [odds ratio (OR) 1.91 (95% confidence interval [CI] 1.29-2.82), ref: HIV negative and OR 1.50 (95% CI 1.01-2.22) ref: non-PI users]. A similar association was found with mMRC scores and PI use [OR 1.79 (95% CI 1.21-2.64), ref: HIV negative and OR 1.53 (95% CI 1.04-2.25), ref: non-PI users]. PI use is associated with worse respiratory health status, increased dyspnea, and an increased prevalence of self-reported pulmonary disease.

The Pseudo-Symmetric N-benzyl Hydroxyethylamine Core in a New Series of Heteroarylcarboxyamide HIV-1 Pr Inhibitors: Synthesis, Molecular Modeling and Biological Evaluation.

Here, we report the synthesis, enzyme inhibition and structure-activity relationship studies of a new potent class of HIV-1 protease inhibitors, which contain a pseudo-symmetric hydroxyethylamine core and heteroarylcarboxyamide moieties. The simple synthetic pathway furnished nine compounds in a few steps with high yields. The compounds were designed taking into account our previous results on other series of inhibitors with different substituents at P' and P'' and different ways of linking them to the inhibitor core. Potent inhibitory activity was obtained with nanomolar IC50 values measured with a standard fluorimetric test in 100 mM MES buffer, pH 5.5, containing 400 mM NaCl, 1 mM EDTA, 1 mM DTT and 1 mg/ml BSA. Compounds 9a-c, containing the indole ring in P1, exhibited an HIV-1 protease inhibitory activity more powerful than darunavir in the same assay. To obtain molecular insight into the binding properties of these compounds, docking analysis was performed, and their binding properties were also compared.

Evaluation of Platelet Activation by HIV Protease Inhibitors - The HIV-PLA II Study.

BACKGROUND: In the past, protease inhibitors (PIs) and the reverse transcriptase inhibitor abacavir were identified increasing the risk for thromboembolic complications and cardiovascular events (CVE) of HIV infected patients taking a combination antiretroviral therapy (cART). Results of the previous HIV-PLA I-study lead to the assumption that platelet activation could play a substantial role in increasing CVE risks. METHODS: The open label, monocentric HIV-PLA II-study investigated HIV-1-infected, therapy-naïve adults (n=45) starting with cART, consisting either of boosted PI (atazanavir, n= 6, darunavir, n=11), NNRTI (efavirenz, n=14) or integrase inhibitor (raltegravir, n=14), each plus tenofovir/emtricitabine co-medication. Main exclusion criteria were tobacco smoking, the intake of NSAIDs or abacavir or past CVE. Platelet adhesive molecule p-selectin (CD62P) and FITC anti-human Integrin α-IIb/Integrin ß-3 (CD41/CD61) antibody (PAC-1) binding, monocyte CD11b/monocyte-associated CD41 expression and the endogenous thrombin potential (ETP) were assessed ex vivo-in vitro at baseline, weeks 4, 12 and 24. Therapy regimens were blinded to the investigators for laboratory and statistical analyses. RESULTS: CD11b and ETP showed no significant changes or differences between all study groups. In contrast, the mean + SD mean fluorescence units (MFI) of CD62P and PAC-1 increased significantly in patients taking PI, indicating an enhanced potential for thrombocyte activation and aggregation. CONCLUSION: CD62P expression, detecting the ɑ-platelet degranulation of pro-inflammatory and pro-thrombotic factors and adhesive proteins, and PAC-1 expression, representing a marker for conformation changes of the GIIb/IIIa receptor, increased significantly in patients taking HIV protease inhibitors. The findings of this study revealed a yet unknown pathway of platelet activation, possibly contributing to the increased risk for CVE under HIV protease inhibitor containing cART. CLINICAL TRIAL REGISTRATION NO: DRKS00000288.

Prescribing intranasal steroids in HIV-positive patients: systematic review of the literature.

BACKGROUND: There are significant drug-drug interactions between human immunodeficiency virus antiretroviral therapy and intranasal steroids, leading to high serum concentrations of iatrogenic steroids and subsequently Cushing's syndrome. METHOD: All articles in the literature on cases of intranasal steroid and antiretroviral therapy interactions were reviewed. Full-length manuscripts were analysed and the relevant data were extracted. RESULTS: A literature search and further cross-referencing yielded a total of seven reports on drug-drug interactions of intranasal corticosteroids and human immunodeficiency virus protease inhibitors, published between 1999 and 2019. CONCLUSION: The use of potent steroids metabolised via CYP3A4, such as fluticasone and budesonide, are not recommended for patients taking ritonavir or cobicistat. Mometasone should be used cautiously with ritonavir because of pharmacokinetic similarities to fluticasone. There was a delayed onset of symptoms in many cases, most likely due to the relatively lower systemic bioavailability of intranasal fluticasone.

Repositioning Lopinavir, an HIV Protease Inhibitor, as a Promising Antifungal Drug: Lessons Learned from Candida albicans-In Silico, In Vitro and In Vivo Approaches.

The repurposing strategy was applied herein to evaluate the effects of lopinavir, an aspartic protease inhibitor currently used in the treatment of HIV-infected individuals, on the globally widespread opportunistic human fungal pathogen Candida albicans by using in silico, in vitro and in vivo approaches in order to decipher its targets on fungal cells and its antifungal mechanisms of action. Secreted aspartic proteases (Saps) are the obviously main target of lopinavir. To confirm this hypothesis, molecular docking assays revealed that lopinavir bound to the Sap2 catalytic site of C. albicans as well as inhibited the Sap hydrolytic activity in a typically dose-dependent manner. The inhibition of Saps culminated in the inability of C. albicans yeasts to assimilate the unique nitrogen source (albumin) available in the culture medium, culminating with fungal growth inhibition (IC50 = 39.8 µM). The antifungal action of lopinavir was corroborated by distinct microscopy analyses, which evidenced drastic and irreversible changes in the morphology that justified the fungal death. Furthermore, our results revealed that lopinavir was able to (i) arrest the yeasts-into-hyphae transformation, (ii) disturb the synthesis of neutral lipids, including ergosterol, (iii) modulate the surface-located molecules, such as Saps and mannose-, sialic acid- and N-acetylglucosamine-containing glycoconjugates, (iv) diminish the secretion of hydrolytic enzymes, such as Saps and esterase, (v) negatively influence the biofilm formation on polystyrene surface, (vi) block the in vitro adhesion to epithelial cells, (vii) contain the in vivo infection in both immunocompetent and immunosuppressed mice and (viii) reduce the Sap production by yeasts recovered from kidneys of infected animals. Conclusively, the exposed results highlight that lopinavir may be used as a promising repurposing drug against C. albicans infection as well as may be used as a lead compound for the development of novel antifungal drugs.

ACE2, TMPRSS2, and L-SIGN Expression in Placentae From HIV-Positive Pregnancies Exposed to Antiretroviral Therapy-Implications for SARS-CoV-2 Placental Infection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binding receptor ACE2 and the spike protein priming protease TMPRSS2 are coexpressed in human placentae. It is unknown whether their expression is altered in the context of HIV infection and antiretroviral therapy (ART). METHODS: We compared mRNA levels of SARS-CoV-2 cell-entry mediators ACE2, TMPRSS2, and L-SIGN by quantitative polymerase chain reaction in 105 placentae: 45 from pregnant women with HIV (WHIV) on protease inhibitor (PI)-based ART, 17 from WHIV on non-PI-based ART, and 43 from HIV-uninfected women. RESULTS: ACE2 levels were lower, while L-SIGN levels were higher, in placentae from WHIV on PI-based ART compared to those on non-PI-based ART and to HIV-uninfected women. TMPRSS2 levels were similar between groups. Black race was significantly associated with lower expression of ACE2 and higher expression of L-SIGN. ACE2 levels were significantly higher in placentae of female fetuses. CONCLUSIONS: We identified pregnant women of black race and WHIV on PI-based ART to have relatively lower expression of placental ACE2 than those of white race and HIV-uninfected women. This may potentially contribute to altered susceptibility to COVID-19 in these women, favorably by reduced viral entry or detrimentally by loss of ACE2 protection against hyperinflammation.

Repositioning HIV protease inhibitors and nucleos(t)ide RNA polymerase inhibitors for the treatment of SARS-CoV-2 infection and COVID-19.

AIMS: SARS-CoV-2 is a single-stranded RNA virus which is part of the ß-coronavirus family (like SARS 2002 and MERS 2012). The high prevalence of hospitalization and mortality, in addition to the lack of vaccines and therapeutics, forces scientists and clinicians around the world to evaluate new therapeutic options. One strategy is the repositioning of already known drugs, which were approved drugs for other indications. SUBJECT AND METHOD: SARS-CoV-2 entry inhibitors, RNA polymerase inhibitors, and protease inhibitors seem to be valuable targets of research. At the beginning of the pandemic, the ClinicalTrials.gov webpage listed n=479 clinical trials related to the antiviral treatment of SARS-CoV-2 (01.04.2020, "SARS-CoV-2," "COVID-19," "antivirals," "therapy"), of which n=376 are still accessible online in January 2021 (10.01.2021). Taking into account further studies not listed in the CTG webpage, this narrative review appraises HIV protease inhibitors and nucleos(t)ide RNA polymerase inhibitors as promising candidates for the treatment of COVID-19. RESULTS: Lopinavir/ritonavir, darunavir/cobicistat, remdesivir, tenofovir-disoproxilfumarate, favipriravir, and sofosbuvir are evaluated in clinical studies worldwide. Study designs show a high variability and results often are contradictory. Remdesivir is the drug, which is deployed in nearly 70% of the reviewed clinical trials, followed by lopinavir/ritonavir, favipiravir, ribavirine, and sofosbuvir. DISCUSSION: This review discusses the pharmacological/clinical background and questions the rationale and study design of clinical trials with already approved HIV protease inhibitors and nucleos(t)ide RNA polymerase inhibitors which are repositioned during the SARS-CoV-2 pandemic worldwide. Proposals are made for future study design and drug repositioning of approved antiretroviral compounds.

Molecular dynamics simulation of docking structures of SARS-CoV-2 main protease and HIV protease inhibitors.

In this paper we investigate 10 different HIV protease inhibitors (HPIs) as possible repurposed-drugs candidates against SARS-CoV-2. To this end, we execute molecular docking and molecular dynamics simulations. The in silico data demonstrated that, despite their molecular differences, all HPIs presented a similar behavior for the parameters analyzed, with the exception of Nelfinavir that showed better results for most of the molecular dynamics parameters in comparison with the N3 inhibitor.

Analysis of the efficacy of HIV protease inhibitors against SARS-CoV-2's main protease.

BACKGROUND: The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in millions of infections worldwide. While the search for an effective antiviral is still ongoing, experimental therapies based on repurposing of available antivirals is being attempted, of which HIV protease inhibitors (PIs) have gained considerable interest. Inhibition profiling of the PIs directly against the viral protease has never been attempted in vitro, and while few studies reported an efficacy of lopinavir and ritonavir in SARS-CoV-2 context, the mechanism of action of the drugs remains to be validated. METHODS: We carried out an in-depth analysis of the efficacy of HIV PIs against the main protease of SARS-CoV-2 (Mpro) in cell culture and in vitro enzymatic assays, using a methodology that enabled us to focus solely on any potential inhibitory effects of the inhibitors against the viral protease. For cell culture experiments a dark-to-bright GFP reporter substrate system was designed. RESULTS: Lopinavir, ritonavir, darunavir, saquinavir, and atazanavir were able to inhibit the viral protease in cell culture, albeit in concentrations much higher than their achievable plasma levels, given their current drug formulations. While inhibition by lopinavir was attributed to its cytotoxicity, ritonavir was the most effective of the panel, with IC50 of 13.7 µM. None of the inhibitors showed significant inhibition of SARS-CoV-2 Mpro in our in vitro enzymatic assays up to 100 µM concentration. CONCLUSION: Targeting of SARS-CoV-2 Mpro by some of the HIV PIs might be of limited clinical potential, given the high concentration of the drugs required to achieve significant inhibition. Therefore, given their weak inhibition of the viral protease, any potential beneficial effect of the PIs in COVID-19 context might perhaps be attributed to acting on other molecular target(s), rather than SARS-CoV-2 Mpro.

Potent Synergistic Interactions between Lopinavir and Azole Antifungal Drugs against Emerging Multidrug-Resistant Candida auris.

The limited therapeutic options and the recent emergence of multidrug-resistant Candida species present a significant challenge to human medicine and underscore the need for novel therapeutic approaches. Drug repurposing appears as a promising tool to augment the activity of current azole antifungals, especially against multidrug-resistant Candida auris In this study, we evaluated the fluconazole chemosensitization activities of 1,547 FDA-approved drugs and clinical molecules against azole-resistant C. auris This led to the discovery that lopinavir, an HIV protease inhibitor, is a potent agent capable of sensitizing C. auris to the effect of azole antifungals. At a therapeutically achievable concentration, lopinavir exhibited potent synergistic interactions with azole drugs, particularly with itraconazole against C. auris (fractional inhibitory concentration index [ΣFICI] ranged from 0.04 to 0.09). Additionally, the lopinavir/itraconazole combination enhanced the survival rate of C. auris-infected Caenorhabditis elegans by 90% and reduced the fungal burden in infected nematodes by 88.5% (P < 0.05) relative to that of the untreated control. Furthermore, lopinavir enhanced the antifungal activity of itraconazole against other medically important Candida species, including C. albicans, C. tropicalis, C. krusei, and C. parapsilosis Comparative transcriptomic profiling and mechanistic studies revealed that lopinavir was able to significantly interfere with the glucose permeation and ATP synthesis. This compromised the efflux ability of C. auris and consequently enhanced the susceptibility to azole drugs, as demonstrated by Nile red efflux assays. Altogether, these findings present lopinavir as a novel, potent, and broad-spectrum azole-chemosensitizing agent that warrants further investigation against recalcitrant Candida infections.