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Repurposing FDA-approved drugs as therapeutics to treat Rift Valley fever virus infection.

Benedict A, Bansal N, Senina S, Hooper I, Lundberg L, de la Fuente C, Narayanan A, Gutting B, Kehn-Hall K - Front Microbiol (2015)

Bottom Line: Several drugs from varying compound classes, including inhibitors of growth factor receptors, microtubule assembly/disassembly, and DNA synthesis, were found to reduce RVFV replication.The hepatocellular and renal cell carcinoma drug, sorafenib, was the most effective inhibitor, being non-toxic and demonstrating inhibition of RVFV in a cell-type and virus strain independent manner.Computational modeling studies also support this conclusion. siRNA knockdown of Raf proteins indicated that non-classical targets of sorafenib are likely important for the replication of RVFV.

View Article: PubMed Central - PubMed

Affiliation: National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University Manassas, VA, USA.

ABSTRACT
There are currently no FDA-approved therapeutics available to treat Rift Valley fever virus (RVFV) infection. In an effort to repurpose drugs for RVFV treatment, a library of FDA-approved drugs was screened to determine their ability to inhibit RVFV. Several drugs from varying compound classes, including inhibitors of growth factor receptors, microtubule assembly/disassembly, and DNA synthesis, were found to reduce RVFV replication. The hepatocellular and renal cell carcinoma drug, sorafenib, was the most effective inhibitor, being non-toxic and demonstrating inhibition of RVFV in a cell-type and virus strain independent manner. Mechanism of action studies indicated that sorafenib targets at least two stages in the virus infectious cycle, RNA synthesis and viral egress. Computational modeling studies also support this conclusion. siRNA knockdown of Raf proteins indicated that non-classical targets of sorafenib are likely important for the replication of RVFV.

No MeSH data available.


Related in: MedlinePlus

Increase in rMP12 intracellular infectivity after sorafenib treatment. (A) HSAECs and (B) Huh7 cells infected with rMP12 (MOI 0.1) were either left untreated, or treated with DMSO, 10 μM sorafenib, or 82 μM ribavirin as described previously. Intra- and extracellular infectivity per infection as determined by plaque assay is plotted. (C) Total infectivity (i.e., sum of intra- and extracellular infectivity) per infection was determined. The percentage of intracellular infectivity relative to the total was plotted for all conditions. Means and standard deviations for four biological replicates are plotted. Two Way ANOVA comparing conditions within each cell background was performed utilizing the Holm-Sidak correction for multiple comparisons. Those comparisons that demonstrated significant differences between DMSO and the other conditions at their respective timepoints are shown. ***p ≤ 0.001, ****p ≤ 0.0001.
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Figure 5: Increase in rMP12 intracellular infectivity after sorafenib treatment. (A) HSAECs and (B) Huh7 cells infected with rMP12 (MOI 0.1) were either left untreated, or treated with DMSO, 10 μM sorafenib, or 82 μM ribavirin as described previously. Intra- and extracellular infectivity per infection as determined by plaque assay is plotted. (C) Total infectivity (i.e., sum of intra- and extracellular infectivity) per infection was determined. The percentage of intracellular infectivity relative to the total was plotted for all conditions. Means and standard deviations for four biological replicates are plotted. Two Way ANOVA comparing conditions within each cell background was performed utilizing the Holm-Sidak correction for multiple comparisons. Those comparisons that demonstrated significant differences between DMSO and the other conditions at their respective timepoints are shown. ***p ≤ 0.001, ****p ≤ 0.0001.

Mentions: To test whether viral egress was impacted, the amount of intra- and extracellular infectivity was examined at both early (8 hpi) and late (24 hpi) timepoints in both HSAEC and Huh7 cells after rMP12 infection (Figure 5). In addition to sorafenib treatment we also included ribavirin, a general inhibitor of viral RNA dependent RNA polymerases (Arias et al., 2008). Inclusion of ribavirin would allow us to account for inhibitor effects on viral RNA replication alone. In both cell types early in RVFV infection, both sorafenib and ribavirin treatment decreased the amount of intracellular infectivity by several orders of magnitude (Figures 5A,B). This results in a subsequent decrease in detectable virus in media supernatants (i.e., extracellular fraction). At 24 hpi, this pattern starts to alter. In the case of ribavirin the amount of intra- and extracellular virus increases slightly in HSAECs while in Huh7 cells levels remain comparable to the 8 h timepoint. Thus if the block to viral RNA replication alone starts to ease (as in the case of HSAEC cells) virus egress is not impeded. However, after treatment with sorafenib, an increase in the intracellular infectivity was observed especially in Huh7 cells. Comparatively, the percentage of intracellular infectivity (relative to the total infectivity) appears to shift with prolonged sorafenib treatment to a significant degree in Huh7 cells (Figure 5C). Collectively these data implicate two points within the RVFV lifecycle as targets for sorafenib inhibition, replication and egress.


Repurposing FDA-approved drugs as therapeutics to treat Rift Valley fever virus infection.

Benedict A, Bansal N, Senina S, Hooper I, Lundberg L, de la Fuente C, Narayanan A, Gutting B, Kehn-Hall K - Front Microbiol (2015)

Increase in rMP12 intracellular infectivity after sorafenib treatment. (A) HSAECs and (B) Huh7 cells infected with rMP12 (MOI 0.1) were either left untreated, or treated with DMSO, 10 μM sorafenib, or 82 μM ribavirin as described previously. Intra- and extracellular infectivity per infection as determined by plaque assay is plotted. (C) Total infectivity (i.e., sum of intra- and extracellular infectivity) per infection was determined. The percentage of intracellular infectivity relative to the total was plotted for all conditions. Means and standard deviations for four biological replicates are plotted. Two Way ANOVA comparing conditions within each cell background was performed utilizing the Holm-Sidak correction for multiple comparisons. Those comparisons that demonstrated significant differences between DMSO and the other conditions at their respective timepoints are shown. ***p ≤ 0.001, ****p ≤ 0.0001.
© Copyright Policy
Related In: Results  -  Collection

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Figure 5: Increase in rMP12 intracellular infectivity after sorafenib treatment. (A) HSAECs and (B) Huh7 cells infected with rMP12 (MOI 0.1) were either left untreated, or treated with DMSO, 10 μM sorafenib, or 82 μM ribavirin as described previously. Intra- and extracellular infectivity per infection as determined by plaque assay is plotted. (C) Total infectivity (i.e., sum of intra- and extracellular infectivity) per infection was determined. The percentage of intracellular infectivity relative to the total was plotted for all conditions. Means and standard deviations for four biological replicates are plotted. Two Way ANOVA comparing conditions within each cell background was performed utilizing the Holm-Sidak correction for multiple comparisons. Those comparisons that demonstrated significant differences between DMSO and the other conditions at their respective timepoints are shown. ***p ≤ 0.001, ****p ≤ 0.0001.
Mentions: To test whether viral egress was impacted, the amount of intra- and extracellular infectivity was examined at both early (8 hpi) and late (24 hpi) timepoints in both HSAEC and Huh7 cells after rMP12 infection (Figure 5). In addition to sorafenib treatment we also included ribavirin, a general inhibitor of viral RNA dependent RNA polymerases (Arias et al., 2008). Inclusion of ribavirin would allow us to account for inhibitor effects on viral RNA replication alone. In both cell types early in RVFV infection, both sorafenib and ribavirin treatment decreased the amount of intracellular infectivity by several orders of magnitude (Figures 5A,B). This results in a subsequent decrease in detectable virus in media supernatants (i.e., extracellular fraction). At 24 hpi, this pattern starts to alter. In the case of ribavirin the amount of intra- and extracellular virus increases slightly in HSAECs while in Huh7 cells levels remain comparable to the 8 h timepoint. Thus if the block to viral RNA replication alone starts to ease (as in the case of HSAEC cells) virus egress is not impeded. However, after treatment with sorafenib, an increase in the intracellular infectivity was observed especially in Huh7 cells. Comparatively, the percentage of intracellular infectivity (relative to the total infectivity) appears to shift with prolonged sorafenib treatment to a significant degree in Huh7 cells (Figure 5C). Collectively these data implicate two points within the RVFV lifecycle as targets for sorafenib inhibition, replication and egress.

Bottom Line: Several drugs from varying compound classes, including inhibitors of growth factor receptors, microtubule assembly/disassembly, and DNA synthesis, were found to reduce RVFV replication.The hepatocellular and renal cell carcinoma drug, sorafenib, was the most effective inhibitor, being non-toxic and demonstrating inhibition of RVFV in a cell-type and virus strain independent manner.Computational modeling studies also support this conclusion. siRNA knockdown of Raf proteins indicated that non-classical targets of sorafenib are likely important for the replication of RVFV.

View Article: PubMed Central - PubMed

Affiliation: National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University Manassas, VA, USA.

ABSTRACT
There are currently no FDA-approved therapeutics available to treat Rift Valley fever virus (RVFV) infection. In an effort to repurpose drugs for RVFV treatment, a library of FDA-approved drugs was screened to determine their ability to inhibit RVFV. Several drugs from varying compound classes, including inhibitors of growth factor receptors, microtubule assembly/disassembly, and DNA synthesis, were found to reduce RVFV replication. The hepatocellular and renal cell carcinoma drug, sorafenib, was the most effective inhibitor, being non-toxic and demonstrating inhibition of RVFV in a cell-type and virus strain independent manner. Mechanism of action studies indicated that sorafenib targets at least two stages in the virus infectious cycle, RNA synthesis and viral egress. Computational modeling studies also support this conclusion. siRNA knockdown of Raf proteins indicated that non-classical targets of sorafenib are likely important for the replication of RVFV.

No MeSH data available.


Related in: MedlinePlus