Antiviral therapies that impede virus entry are attractive because they act on the first phase of the infectious cycle. Drugs that target pathways common to multiple viruses are particularly desirable when laboratory-based viral identification may be challenging, e.g., in an outbreak setting. We are interested in identifying drugs that block both Ebola virus (EBOV) and Lassa virus (LASV), two unrelated but highly pathogenic hemorrhagic fever viruses that have caused outbreaks in similar regions in Africa and share features of virus entry: use of cell surface attachment factors, macropinocytosis, endosomal receptors, and low pH to trigger fusion in late endosomes. Toward this goal, we directly compared the potency of eight drugs known to block EBOV entry with their potency as inhibitors of LASV entry. Five drugs (amodiaquine, apilimod, arbidol, niclosamide, and zoniporide) showed roughly equivalent degrees of inhibition of LASV and EBOV glycoprotein (GP)-bearing pseudoviruses; three (clomiphene, sertraline, and toremifene) were more potent against EBOV. We then focused on arbidol, which is licensed abroad as an anti-influenza drug and exhibits activity against a diverse array of clinically relevant viruses. We found that arbidol inhibits infection by authentic LASV, inhibits LASV GP-mediated cell-cell fusion and virus-cell fusion, and, reminiscent of its activity on influenza virus hemagglutinin, stabilizes LASV GP to low-pH exposure. Our findings suggest that arbidol inhibits LASV fusion, which may partly involve blocking conformational changes in LASV GP. We discuss our findings in terms of the potential to develop a drug cocktail that could inhibit both LASV and EBOV. IMPORTANCE Lassa and Ebola viruses continue to cause severe outbreaks in humans, yet there are only limited therapeutic options to treat the deadly hemorrhagic fever diseases they cause. Because of overlapping geographic occurrences and similarities in mode of entry into cells, we seek a practical drug or drug cocktail that could be used to treat infections by both viruses. Toward this goal, we directly compared eight drugs, approved or in clinical testing, for the ability to block entry mediated by the glycoproteins of both viruses. We identified five drugs with approximately equal potencies against both. Among these, we investigated the modes of action of arbidol, a drug licensed abroad to treat influenza infections. We found, as shown for influenza virus, that arbidol blocks fusion mediated by the Lassa virus glycoprotein. Our findings encourage the development of a combination of approved drugs to treat both Lassa and Ebola virus diseases. FIG 2 Comparative effects of arbidol on infection by MLV pseudoviruses bearing LASV or other viral glycoproteins: LASV, LCMV, and Junin GP (A) and LASV GP and influenza virus HA (B). MLV pseudoviruses bearing LASV GP, LCMV GP, Junin GP, or WSN influenza HA and NA were prepared as described in Materials and Methods. BSC-1 cells were pretreated with the indicated concentrations of arbidol and then processed an...

Influenza A viruses, which are further subtyped on the basis of antigenic differences in external hemagglutinin and neuraminidase glycoproteins, and influenza B viruses are prominent among the viral causes of respiratory diseases and can cause a wide spectrum of illness. Each year these viruses are responsible for recurrent epidemics, frequently in association with genetic variation. There is a requirement for sensitive and rapid diagnostic techniques in order to improve both the diagnosis of infections and the quality of surveillance systems. A new three-dimensional biochip platform (Flow-Thru Chip; MetriGenix) was used to develop a rapid and reliable molecular method for the typing and subtyping of influenza viruses. Oligonucleotide probes immobilized in microchannels of a silicon wafer were selected to recognize multiple fragments of the influenza A virus matrix protein gene; the influenza B virus NS gene; the H1, H3, and H5 hemagglutinin genes; and the N1 and N2 neuraminidase genes. Biotinylated amplicons resulting from either multiplex or random reverse transcription-PCR were hybridized to arrayed oligonucleotides on the influenza virus chip before they were stained with horseradish peroxidase-streptavidin and were imaged by use of a chemiluminescent substrate. The chip analysis procedure, from the time of pipetting of the sample into the chip cartridge to the time of analysis of the results, was performed in less than 5 h. The random PCR exhibited a higher level of performance than the multiplex PCR in terms of the specificity of product hybridization to the influenza virus chip. Analysis of influenza A viruses (H1N1, H3N2, H1N2, and H5N1) and influenza B viruses showed that this microarraybased method is capable of the rapid and unambiguous identification of all types and subtypes of viruses by use of random PCR products. The redundancy of the probes designed for each gene selected yielded an additional criterion of confidence for the subtyping of viruses which are known for antigenic variations in some of their components.

One important goal in cardiology is to prevent necrotic cell death in the heart. Necrotic cell death attracts neutrophils and monocytes into the injured myocardium. The consequences are fibrosis, remodelling and cardiac failure. The renin-angiotensin system promotes the development of cardiac failure. Recently, alternative renin transcripts have been identified lacking the signal sequence for a cotranslational transport to the endoplasmatic reticulum. These transcripts encode for a cytosolic renin with unknown functions. The expression of this alternative transcript increases after myocardial infarction. We hypothesized that cytosolic renin plays a role in survival and death of cardiomyocytes. To test this hypothesis, we overexpressed secretory or cytosolic renin in H9c2 cardiomyblasts and determined the rate of proliferation, necrosis and apoptosis. Proliferation rate, as indicated by BrdU incorporation into DNA, was reduced by secretory and cytosolic renin (cells transfected with control vector: 0.33 ± 0.06; secretory renin: 0.12 ± 0.02; P < 0.05; cytosolic renin: 0.15 ± 0.03; P < 0.05). Necrosis was increased by secretory renin but decreased by cytosolic renin (LDH release after 10 days from cells transfected with control vector: 68.5 ± 14.9; secretory renin: 100.0 ± 0; cytosolic renin: 25.5 ± 5.3% of content, each P < 0.05). Mitochondrial apoptosis, as indicated by phosphatidylserin translocation to the outer membrane, was unaffected by secretory renin but increased by cytosolic renin (controls: 23.8 ± 3.9%; secretory renin: 22.1 ± 4.7%; cytoplasmatic renin: 41.2 ± 3.8%; P < 0.05). The data demonstrate that a cytosolic renin exists in cardiomyocytes, which in contradiction to secretory renin protects from necrosis but increases apoptosis. Non-secretory cytosolic renin can be considered as a new target for cardiac failure.

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