Influence of Ethanol on Darunavir Hepatic Clearance and Intracellular PK/PD in HIV-Infected Monocytes, and CYP3A4-Darunavir Interactions Using Inhibition and in Silico Binding Studies

LM11A-31, a modulator of p75 neurotrophin receptor, suppresses HIV-1 replication and inflammatory response in macrophages

Antiretroviral drugs have made significant progress in treating HIV-1 and improving the quality of HIV-1-infected individuals. However, due to their limited permeability into the brain HIV-1 replication persists in brain reservoirs such as perivascular macrophages and microglia, which cause HIV-1-associated neurocognitive disorders. Therefore, it is highly desirable to find a novel therapy that can cross the blood-brain barrier (BBB) and target HIV-1 pathogenesis in brain reservoirs. A recently developed 2-amino-3-methylpentanoic acid [2-morpholin-4-yl-ethyl]-amide (LM11A-31), which is a p75 neutrotrophin receptor (p75NTR) modulator, can cross the BBB. In this study, we examined whether LM11A-31 treatment can suppress HIV-1 replication, oxidative stress, cytotoxicity, and inflammatory response in macrophages. Our results showed that LM11A-31 (100 nM) alone and/or in combination with positive control darunavir (5.5 µM) significantly suppresses viral replication and reduces cytotoxicity. Moreover, the HIV-1 suppression by LM11A-31 was comparable to the HIV-1 suppression by darunavir. Although p75NTR was upregulated in HIV-1-infected macrophages compared to uninfected macrophages, LM11A-31 did not significantly reduce the p75NTR expression in macrophages. Furthermore, our study illustrated that LM11A-31 alone and/or in combination with darunavir significantly suppress pro-inflammatory cytokines including IL-1β, IL-8, IL-18, and TNF-α and chemokines MCP-1 in HIV-induced macrophages. The suppression of these cytokines and chemokines by LM11A-31 was comparable to darunavir. In contrast, LM11A-31 did not significantly alter oxidative stress, expression of antioxidant enzymes, or autophagy marker proteins in U1 macrophages. The results suggest that LM11A-31, which can cross the BBB, has therapeutic potential in suppressing HIV-1 and inflammatory response in brain reservoirs, especially in macrophages.

Darunavir Nanoformulation Suppresses HIV Pathogenesis in Macrophages and Improves Drug Delivery to the Brain in Mice

Although antiretroviral therapy (ART) can suppress peripheral HIV, patients still suffer from neuroHIV due to insufficient levels of ART drugs in the brain. Hence, this study focuses on developing a poly lactic-co-glycolic acid (PLGA) nanoparticle-based ART drug delivery system for darunavir (DRV) using an intranasal route that can overcome the limitation of drug metabolic stability and blood-brain barrier (BBB) permeability. The physicochemical properties of PLGA-DRV were characterized. The results indicated that PLGA-DRV formulation inhibits HIV replication in U1 macrophages directly and in the presence of the BBB without inducing cytotoxicity. However, the PLGA-DRV did not inhibit HIV replication more than DRV alone. Notably, the total antioxidant capacity remained unchanged upon treatment with both DRV or PLGA-DRV in U1 cells. Compared to DRV alone, PLGA-DRV further decreased reactive oxygen species, suggesting a decrease in oxidative stress by the formulation. Oxidative stress is generally increased by HIV infection, leading to increased inflammation. Although the PLGA-DRV formulation did not further reduce the inflammatory response, the formulation did not provoke an inflammatory response in HIV-infected U1 macrophages. As expected, in vitro experiments showed higher DRV permeability by PLGA-DRV than DRV alone to U1 macrophages. Importantly, in vivo experiments, especially using intranasal administration of PLGA-DRV in wild-type mice, demonstrated a significant increase in the brain-to-plasma ratio of DRV compared to the free DRV. Overall, findings from this study attest to the potential of the PLGA-DRV nanoformulation in reducing HIV pathogenesis in macrophages and enhancing drug delivery to the brain, offering a promising avenue for treating HIV-related neurological disorders.

An update on drug-drug interactions between antiretroviral therapies and drugs of abuse in HIV systems

INTRODUCTION

While considerable progress has been made in the fight against HIV/AIDS, to date there has not been a cure, and millions of people around the world are currently living with HIV/AIDS. People living with HIV/AIDS have substance abuse disorders at higher rates than non-infected individuals, which puts them at an increased risk of drug-drug interactions.

AREAS COVERED

Potential drug-drug interactions are reviewed for a variety of potential drugs of abuse, both licit and illicit. These drugs include alcohol, cigarettes or other nicotine delivery systems, methamphetamine, cocaine, opioids, and marijuana. Potential interactions include decreased adherence, modulation of drug transporters, or modulation of metabolic enzymes. We also review the relative incidence of the use of these drugs of abuse in People living with HIV/AIDS.

EXPERT OPINION

Despite considerable improvements in outcomes, disparities in outcomes between PLWHA who use drugs of abuse, vs those who do not still exist. It is of critical necessity to improve outcomes in these patients and to work with them to stop abusing drugs of abuse.

Novel HIV-1 capsid-targeting small molecules of the PF74 binding site

The PF74 binding site in HIV-1 capsid protein (CA) is a compelling antiviral drug target. Although PF74 confers mechanistically distinct antiviral phenotypes by competing against host factors for CA binding, it suffers from prohibitively low metabolic stability. Therefore, there has been increasing interest in designing novel sub-chemotypes of PF74 with similar binding mode and improved metabolic stability. We report herein our efforts to explore the inter-domain interacting indole moiety for designing novel CA-targeting small molecules. Our design includes simple substitution on the indole ring, and more importantly, novel sub-chemotypes with the indole moiety replaced with a few less electron-rich rings. All 56 novel analogs were synthesized and evaluated for antiviral activity, cytotoxicity, and impact on CA hexamer stability. Selected analogs were tested for metabolic stability in liver microsomes. Molecular modeling was performed to verify compound binding to the PF74 site. In the end, 5-hydroxyindole analogs (8,9 and 12) showed improved potency (up to 20-fold) over PF74. Of the novel sub-chemotypes, α- and β-naphthyl analogs (33 and 27) exhibited sub micromolar antiviral potencies comparable to that of PF74. Interestingly, although only moderately inhibiting HIV-1 (single-digit micromolar EC₅₀s), analogs of the 2-indolone sub-chemotype consistently lowered the melting point (T_m) of CA hexamers, some with improved metabolic stability over PF74.

Pharmacokinetic drug evaluation of ritonavir (versus cobicistat) as adjunctive therapy in the treatment of HIV

Introduction: Ritonavir and cobicistat are pharmacoenhancers used to improve the disposition of other HIV antiretrovirals. These drugs are, however, characterized by important pharmacokinetic differences.Areas covered: Here, the authors firstly update the available information on the pharmacokinetics of ritonavir and cobicistat. Subsequently, the review focuses on the description of drug-drug interactions (DDIs) involving cobicistat and comedications that might beneficiate from a shift-back to ritonavir. A MEDLINE Pubmed search for articles published from January 1995 to April 2019 was completed matching the term ritonavir or cobicistat with pharmacokinetics, DDIs, and pharmacology. Moreover, additional studies were identified from the reference list of retrieved articles.Expert opinion: Despite more than 20 years after its introduction on the market, ritonavir still represents a valid option for the treatment of selected HIV-infected patients. The large-scale switch to cobicistat may result in some unexpected DDIs not previously reported for ritonavir. Besides the issue of DDIs, additional advantage of ritonavir over cobicistat is its use in pregnancy, and its availability as single component of pharmaceutical formulations allowing the fine-tuning of antiretroviral regimens in patients with heavy polypharmacy when other unboosted-based therapeutic options cannot be used.

The role of cytochrome P450 2E1 on ethanol-mediated oxidative stress and HIV replication in human monocyte-derived macrophages

Background

Alcohol consumption is considered to be a major health problem among people living with HIV/AIDS. Our previous reports have shown that ethanol reduced intracellular concentrations of antiretroviral drugs elvitegravir and darunavir in the HIV-1-infected U1 cell line. Ethanol also increased HIV-1 replication despite the presence of elvitegravir. Our previous finding has also shown that the levels of cytochrome P450 enzyme 2E1 (CYP2E1) and oxidative stress in blood monocytes were induced, while the concentration of alcohol in the plasma was reduced in HIV-1-infected alcohol users compared to uninfected alcohol users. However, the role of CYP2E1 in ethanol-enhanced oxidative stress and HIV-1 replication is still unclear.

Methods

This study examined the chronic effects (14 days) of ethanol on HIV viral load, oxidative DNA damage, expression of CYP2E1, expression of antioxidant enzymes (AOEs), expression of reactive oxygen species (ROS) in human monocyte-derived macrophages (MDM). Further, to evaluate the role of CYP2E1 in mediating ethanol-induced viral replication, CYP2E1 siRNA and CYP2E1 selective inhibitor were used in the HIV-1-infected U1 cell line following ethanol treatment.

Results

Chronic ethanol exposure demonstrated an increase in oxidative DNA damage and CYP2E1 expression in both non-infected and HIV-1-infected MDM. Our results showed that ethanol chronic exposure increased HIV-1 replication by ~3-fold in HIV-1-infected MDM. This ethanol-enhanced HIV-1 replication was associated with an increased oxidative DNA damage, an increased expression of CYP2E1, and a decreased expression of antioxidant enzyme PRDX6. In HIV-1-infected U1 cell line, we observed a decreased viral replication (~30%) and a decreased DNA damage (~100%) after repression of CYP2E1 by siRNA, upon ethanol exposure. We also observed a decreased viral replication (~25%) after inhibition of CYP2E1 by using selective CYP2E1 inhibitor.

Conclusions

The data suggest that chronic ethanol exposure increases HIV-1 replication in MDM, at least in part, through CYP2E1-mediated oxidative stress. These results are clinically relevant to potentially find effective treatment strategies for HIV-1-infected alcohol users.

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Chronic EtOH exposure increased HIV-1 replication and oxidative DNA damage in MDM.

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Chronic EtOH exposure increased CYP2E1 expression in MDM.

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EtOH-enhanced HIV replication and DNA damage were prevented by CYP2E1 siRNA.

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Selective CYP2E1 inhibitor decreased HIV-1 replication upon ethanol exposure.