Jegou, B. | bioRxiv Science

bioRxiv2023

Paracetamol/acetaminophen hepatotoxicity: new markers for monitoring the elimination of the reactive N-Acetyl-p-benzoquinone imine

Paracetamol/acetaminophen (N-acetyl-p-aminophenol, APAP) overdose is one of the most important causes of drug-induced liver injury worldwide. Hepatotoxicity induced by APAP is mainly caused by the production of N-acetyl-p-benzoquinone imine (NAPQI), a highly reactive intermediate formed predominantly via the cytochrome P450 2E1. Here, we used human studies and in vitro models to demonstrate that NAPQI-derived thiomethyl metabolites identified using high-resolution mass spectrometry could serve to monitor NAPQI detoxification and elimination in patients (after intake at recommended dose or after intoxication), and to study inter-individual variability in NAPQI production. Using in vitro human models, we showed that these thiomethyl metabolites are directly linked to NAPQI detoxification since they are mainly formed after exposure to glutathione-derived conjugates via an overlooked pathway called the thiomethyl shunt. These long-term thiomethyl metabolites have great potential in future clinical studies in order to provide a more reliable history of APAP ingestion in case of acute intoxication or to study underlying causes involved in APAP-induced hepatotoxicity. One Sentence SummaryThiomethyl metabolites are new markers to monitor the elimination of the toxic N-acetyl-p-benzoquinone imine after therapeutic use or intoxication.

pharmacology and toxicology↗

bioRxiv2020

Potential for virus endogenization in humans through testicular germ cell infection: the case of HIV

Viruses have colonized the germ line of our ancestors at several occasions during evolution, leading to the integration in the human genome of viral sequences from over 30 retroviral groups and a few non-retroviruses. Among the recently emerged viruses infecting humans, several target the testis (eg HIV, Zika and Ebola viruses). Here we aimed to investigate whether human testicular germ cells (TGCs) can support integration by HIV, a contemporary retrovirus that started to spread in the human population during the last century. We report that albeit alternative receptors enabled HIV-1 binding to TGCs, HIV virions failed to infect TGCs in vitro. Nevertheless, exposure of TGCs to infected lymphocytes, naturally present in the testis from HIV+ men, led to HIV-1 entry, integration and early protein expression. Similarly, cell-associated infection or bypassing viral entry led to HIV-1 integration in a spermatogonial cell line. Using DNAscope, HIV-1 and SIV DNA were detected within a few TGCs in the testis from one infected patient, one rhesus macaque and one African Green monkey in vivo. Molecular landscape analysis revealed that early TGCs were enriched in HIV early co-factors up to integration and had overall low antiviral defenses when compared with testicular macrophages and Sertoli cells. In conclusion, our study reveals that TGCs can support the entry and integration of HIV upon cell-associated infection. This could represent a way for this contemporary virus to integrate our germline and become endogenous in the future, as happened during human evolution for a number of viruses. ImportanceViruses have colonized the host germ line at many occasions during evolution to eventually become endogenous. Here we aimed at investigating whether human testicular germ cells (TGCs) can support such viral invasion by studying HIV interactions with TGCs in vitro. Our results indicate that isolated primary TGCs express alternative HIV-1 receptors allowing virions binding but not entry. However, HIV-1 entered and integrated in TGCs upon cell-associated infection, and produced low level of viral proteins. In vivo, HIV-1 and SIV DNA was detected in a few TGCs. Molecular landscape analysis showed that TGCs have overall weak antiviral defenses. Altogether, our results indicate that human TGCs can support HIV-1 early replication including integration, suggesting potential for endogenization in the future generations.

microbiology↗