CYP2E1 metabolizes ethanol leading to production of reactive oxygen species (ROS) and acetaldehyde, which are known to cause not only liver damage but also toxicity to other organs. However, the signaling pathways involved in CYP2E1 regulation by ethanol are not clear, especially in extra-hepatic cells. This study was designed to examine the role of CYP2E1 in ethanol-mediated oxidative stress and cytotoxicity, as well as signaling pathways by which ethanol regulates CYP2E1 in extra-hepatic cells. In this study, we used astrocytic and monocytic cell lines, because they are important cells in central nervous system . Our results showed that 100 mM ethanol significantly induced oxidative stress, apoptosis, and cell death at 24 h in the SVGA astrocytic cell line, which was rescued by a CYP2E1 selective inhibitor, diallyl sulfide (DAS), CYP2E1 siRNA, and antioxidants (vitamins C and E). Further, we showed that DAS and vitamin C abrogated ethanol-mediated (50 mℳ) induction of CYP2E1 at 6 h, as well as production of ROS at 2 h, suggesting the role of oxidative stress in ethanol-mediated induction of CYP2E1. We then investigated the role of the protein kinase C/c-Jun N-terminal kinase/specificity protein1 (PKC/JNK/SP1) pathway in oxidative stress-mediated CYP2E1 induction. Our results showed that staurosporine, a non-specific inhibitor of PKC, as well as specific PKCζ inhibitor and PKCζ siRNA, abolished ethanol-induced CYP2E1 expression. In addition, inhibitors of JNK (SP600125) and SP1 (mithramycin A) completely abrogated induction of CYP2E1 by ethanol in SVGA astrocytes. Subsequently, we showed that CYP2E1 is also responsible for ethanol-mediated oxidative stress and apoptotic cell death in U937 monocytic cell lines. Finally, our results showed that PKC/JNK/SP1 pathway is also involved in regulation of CYP2E1 in U937 cells. This study has clinical implications with respect to alcohol-associated neuroinflammatory toxicity among alcohol users.

In January 2020, Chinese health agencies reported an outbreak of a novel coronavirus-2 (CoV-2) which can lead to severe acute respiratory syndrome (SARS). The virus, which belongs to the coronavirus family (SARS-CoV-2), was named coronavirus disease 2019 (COVID-19) and declared a pandemic by the World Health Organization (WHO). Full-length genome sequences of SARS-CoV-2 showed 79.6% sequence identity to SARS-CoV, with 96% identity to a bat coronavirus at the whole-genome level. COVID-19 has caused over 133,000 deaths and there are over 2 million total confirmed cases as of 15 April 2020. Current treatment plans are still under investigation due to a lack of understanding of COVID-19. One potential mechanism to slow disease progression is the use of antiviral drugs to either block the entry of the virus or interfere with viral replication and maturation. Currently, antiviral drugs, including chloroquine/hydroxychloroquine, remdesivir, and lopinavir/ritonavir, have shown effective inhibition of SARS-CoV-2 in vitro. Due to the high dose needed and narrow therapeutic window, many patients are experiencing severe side effects with the above drugs. Hence, repurposing these drugs with a proper formulation is needed to improve the safety and efficacy for COVID-19 treatment. Extracellular vesicles (EVs) are a family of natural carriers in the human body. They play a critical role in cell-to-cell communications. EVs can be used as unique drug carriers to deliver protease inhibitors to treat COVID-19. EVs may provide targeted delivery of protease inhibitors, with fewer systemic side effects. More importantly, EVs are eligible for major aseptic processing and can be upscaled for mass production. Currently, the FDA is facilitating applications to treat COVID-19, which provides a very good chance to use EVs to contribute in this combat.

Introduction Substance abuse is a common problem among HIV-infected individuals. Importantly, addictions as well as moderate use of alcohol, smoking, or other illicit drugs have been identified as major reasons for non-adherence to antiretroviral therapy (ART) among HIV patients. The literature also suggests a decrease in the response to ART among HIV patients who use these substances, leading to failure to achieve optimal virological response and increased disease progression. Areas covered This review discusses the challenges with adherence to ART as well as observed drug interactions and known toxicities with major drugs of abuse, such as alcohol, smoking, methamphetamine, cocaine, marijuana, and opioids. The lack of adherence and drug interactions potentially lead to decreased efficacy of ART drugs and increased ART, and drugs of abuse-mediated toxicity. As CYP is the common pathway in metabolizing both ART and drugs of abuse, we discuss the possible involvement of CYP pathways in such drug interactions. Expert opinion We acknowledge that further studies focusing on common metabolic pathways involving CYP and advance research in this area would help to potentially develop novel/alternate interventions and drug dose/regimen adjustments to improve medication outcomes in HIV patients who consume drugs of abuse.

Background ATP-binding cassette (ABC) proteins and cytochrome P450 (CYP) enzymes regulate the bioavailability of HIV-1 antiretroviral therapeutic (ART) drugs, non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs). They are also involved in regulating, and responding to, oxidative stress in various tissues and organs including liver. The present study is designed to assess the effect of alcohol on the ABCC1 and CYP enzymes involved in the metabolism of NNRTIs and PIs (CYP2B6, CYP2D6, CYP3A4) and oxidative stress (CYP1A1, CYP2A6, CYP2E1) in U937 macrophages. The U937 cell line has been utilized as an in vitro model of human macrophages. Methods The expression levels of the ABCC1 and CYP enzymes in U937 macrophages were characterized in terms of mRNA quantification, protein analysis, and assays for functional activity. In addition, oxidative stress was monitored by measuring the activities of oxidative stress marker enzymes and production of reactive oxygen species (ROS). Results The order of mRNA expression in U937 macrophages was ABCC1 ~ CYP2A6 > CYP3A4 ~ CYP2E1 ~ CYP1A1 > CYP2D6 > CYP2B6. Alcohol (100 mM) increased the mRNA levels of ABCC1 and CYP2A6 (200%), CYP2B6 and CYP3A4 (150%), and CYP2E1 (400%) compared with the control. Alcohol caused significant upregulation of ABCC1, CYP2A6, CYP2E1, and CYP3A4 proteins (50-85%) and showed >50% increase in the specific activity of CYP2A6 and CYP3A4 in U937 macrophages. Furthermore, alcohol increased the production of ROS and significantly enhanced the activity of oxidative stress marker enzymes, superoxide dismutase and catalase in U937 macrophages. Conclusions Our study showed that alcohol causes increases in genetic and functional expressions of ABCC1 and CYP enzymes in U937 macrophages. This study has clinical implications in alcoholic HIV-1 individuals, because alcohol consumption is reported to reduce the therapeutic efficacy of NNRTIs and PIs and increases oxidative stress.

Importance of the field: Cytochrome P450 enzymes comprise a superfamily of heme monooxygenases that are of considerable interest for the: 1) synthesis of novel drugs and drug metabolites, 2) targeted cancer gene therapy, 3) biosensor design, and 4) bioremediation. However, their applications are limited because cytochrome P450, especially mammalian P450 enzymes, show a low turnover rate and stability, and require a complex source of electrons through cytochrome P450 reductase and NADPH. Areas covered in this review: In this review, we discuss the recent progress towards the use of P450 enzymes in a variety of above-mentioned applications. We also present alternate and cost-effective ways to perform P450-mediated reaction, especially using peroxides. Furthermore, we expand upon the current progress in P450 engineering approaches describing several recent examples that are utilized to enhance heterologous expression, stability, catalytic efficiency, and utilization of alternate oxidants. What the reader will gain: The review will provide a comprehensive knowledge in the design of P450 biocatalysts for potentially practical purposes. Finally, we provide a prospective on the future aspects of P450 engineering and its applications in biotechnology, medicine, and bioremediation. Take home message: Because of its wide applications, academic and pharmaceutical researchers, environmental scientists, and health care providers are expected to gain current knowledge and future prospects of the practical use of P450 biocatalysts.