Aoyagi, H. | Search bioRxiv

bioRxiv2026

Vorapaxar and aripiprazole suppress hepatitis B virus replication through distinct host signaling pathways

Background & AimsCurrent nucleos(t)ide analogs efficiently suppress hepatitis B virus (HBV) replication but have limited effects on viral transcription from covalently closed circular DNA (cccDNA) and integrated HBV DNA. We aimed to identify clinically applicable compounds that directly inhibit HBV transcription by screening FDA-approved drugs. Approach & ResultsScreening of 1,470 FDA-approved compounds using an HBV enhancer I/X promoter reporter system identified vorapaxar and aripiprazole as potent inhibitors of viral promoter activity. Both compounds suppressed HBV replication in HBV-producing cells, HBV-infected HepG2-hNTCP cells, and primary human hepatocytes. Aripiprazole reduced hepatocyte nuclear factor 4 (HNF4) protein levels through an ERK/JNK-dependent pathway and inhibited HBV core promoter activity, whereas vorapaxar acted independently of HNF4. Both compounds suppressed enhancer I/X promoter activity through inhibition of STAT3 signaling. Vorapaxar inhibited PAR-1-mediated SRC, EGFR, and STAT3 activation, while aripiprazole suppressed SRC-STAT3 signaling independently of EGFR. PAR-1 activation enhanced HBV transcription, whereas PAR-1 knockdown reduced promoter activity and viral RNA expression. Both compounds also reduced HBV replication in human liver chimeric mice at clinically relevant exposure levels without apparent severe toxicity. ConclusionsVorapaxar and aripiprazole suppress HBV transcription and replication through distinct host signaling pathways. These findings identify PAR-1-STAT3 signaling as a previously unrecognized regulator of HBV transcription and suggest that host-targeting approaches may complement current therapies by suppressing viral gene expression from both cccDNA and integrated HBV DNA. Impact and implicationsCurrent nucleos(t)ide analogues effectively suppress HBV reverse transcription but have limited effects on viral transcription from cccDNA and integrated HBV DNA, highlighting the need for therapies targeting viral gene expression. We identify PAR-1- STAT3 signaling as a previously unrecognized regulator of HBV transcription and demonstrate that two clinically approved drugs, vorapaxar and aripiprazole, suppress HBV replication through distinct host signaling pathways. These findings are relevant to researchers developing host-targeting antivirals and to clinicians seeking complementary therapeutic strategies beyond current nucleos(t)ide analogue therapy. Although further clinical validation and combination studies are required, our results provide a rationale for repurposing approved drugs and for developing transcription-targeting therapies that may complement existing treatments for chronic hepatitis B. HighlightsO_LIVorapaxar and aripiprazole suppress HBV through distinct host pathways. C_LIO_LIBoth drugs inhibit HBV replication in vitro and in humanized liver mice. C_LIO_LIPAR-1 inhibition reduces HBV transcription by blocking SRC/EGFR/STAT3 signaling. C_LIO_LIPAR-1-STAT3 signaling is a novel regulator of HBV transcription. C_LIO_LIHost-targeting antiviral therapy complements current HBV treatment. C_LI

pharmacology and toxicology↗

bioRxiv2023

Proteomic characterization of aging-driven changes in the mouse brain by co-expression network analysis

Brain aging causes a progressive decline in functional capacity and is a strong risk factor for dementias such as Alzheimers disease. To characterize age-related proteomic changes in the brain, we used quantitative proteomics to examine brain tissues, cortex and hippocampus, of mice at three age points (3, 15, and 24 months old), and quantified more than 7,000 proteins in total with high reproducibility. We found that many of the proteins upregulated with age were extracellular proteins, such as extracellular matrix proteins and secreted proteins, associated with glial cells. On the other hand, many of the significantly downregulated proteins were associated with synapses, particularly postsynaptic density, specifically in the cortex but not in the hippocampus. Our datasets will be helpful as resources for understanding the molecular basis of brain aging.

molecular biology↗

bioRxiv2021

In Vitro Proliferation and Long-Term Preservation of Functional Primary Rat Hepatocytes in Cell Fibers

Primary hepatocytes are essential cellular resource for drug screening and medical transplantation. Since culture systems for them have already succeeded in reconstituting the biomimetic microenvironment, acquiring additional capabilities both to expand primary hepatocytes and to handle them easily would be expected as progress to the next stage. This paper describes a culture system for primary rat hepatocytes that is equipped with scalability and handleability relying on cell fiber technology. Cell fibers are cell-laden core-shell hydrogel microfibers; in the core regions, cells are embedded in extracellular matrix proteins, cultured three-dimensionally, and exposed to soluble growth factors in the culture medium through the hydrogel shells. By encapsulating primary rat hepatocytes within cell fibers, we first demonstrated they increase in number while keeping their viability and their hepatic specific functions for up to thirty days of subsequent culture. Then, we demonstrated the potency of the primary rat hepatocytes that proliferate in cell fibers not only as cell-based sensors to detect drugs that damage hepatic functions and hepatocellular processes but also as transplants to improve the plasma albumin concentrations of congenital analbuminemia. Therefore, our culture system could serve for innovating strategies and promising developments in applying primary hepatocytes to both pharmaceutical and medical fields.

bioengineering↗