Limits...
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

RVFV luciferase assay development. Vero cells were either untreated or preincubated with DMSO or 10 μM curcumin for 1 h prior to infection with MP12 ΔNSs-Luc (MOI 0.1, 1.0, or 10). After 1 h infection, virus inoculum was removed, cells washed and media containing respective treatments was added back to cells. Twenty-four hours post infection (hpi), luciferase activity was measured and graphed in relative luminescence units (RLU). The average and standard deviation of three biological replicates are plotted.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4495339&req=5

Figure 1: RVFV luciferase assay development. Vero cells were either untreated or preincubated with DMSO or 10 μM curcumin for 1 h prior to infection with MP12 ΔNSs-Luc (MOI 0.1, 1.0, or 10). After 1 h infection, virus inoculum was removed, cells washed and media containing respective treatments was added back to cells. Twenty-four hours post infection (hpi), luciferase activity was measured and graphed in relative luminescence units (RLU). The average and standard deviation of three biological replicates are plotted.

Mentions: In order to determine which of 420 FDA-approved drugs were effective at inhibiting RVFV infection, a high throughput assay was first optimized. The reporter virus, RVFV MP12-Luc, which encodes for Renilla luciferase in place of NSs (a non-structural protein that is not essential for virus replication), was utilized to measure virus replication. Vero cells were left untreated or pre-treated with DMSO or curcumin for 1 h prior to infection. Curcumin was used as a positive control for inhibition, since it has been shown to decrease RVFV infection (Narayanan et al., 2012). After pre-treatment, cells were infected with MP12-Luc at a MOI of 0.1, 1.0 or 10. One hour following infection, media containing the respective treatment was added back and cells cultured until 24 h post-infection (hpi). At this time, cells were lysed and relative luminescence determined. In both untreated and DMSO samples, there was an increase in luminescence relative to MOI. As expected, curcumin treatment decreased RVFV infection to levels that were almost undetectable (Figure 1). Z′ factors were calculated for each of the MOIs tested. The Z′ factor is used to assess the quality of an assay in order to predict if it would be useful in a high-throughput setting. A Z′ factor of 1.0 is ideal and cannot be exceeded; between 0.5 and 1.0 denotes an excellent assay; between 0 and 0.5 denotes a marginal assay; and a Z′ factor less than 0 indicates that there is too much overlap between the positive and the negative controls for the assay to be useful (Zhang et al., 1999). Based on our results, the condition chosen for the high-throughput assay was MOI 0.1 since infection at this MOI resulted in the highest Z′ factor (Z′ = 0.89).


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)

RVFV luciferase assay development. Vero cells were either untreated or preincubated with DMSO or 10 μM curcumin for 1 h prior to infection with MP12 ΔNSs-Luc (MOI 0.1, 1.0, or 10). After 1 h infection, virus inoculum was removed, cells washed and media containing respective treatments was added back to cells. Twenty-four hours post infection (hpi), luciferase activity was measured and graphed in relative luminescence units (RLU). The average and standard deviation of three biological replicates are plotted.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495339&req=5

Figure 1: RVFV luciferase assay development. Vero cells were either untreated or preincubated with DMSO or 10 μM curcumin for 1 h prior to infection with MP12 ΔNSs-Luc (MOI 0.1, 1.0, or 10). After 1 h infection, virus inoculum was removed, cells washed and media containing respective treatments was added back to cells. Twenty-four hours post infection (hpi), luciferase activity was measured and graphed in relative luminescence units (RLU). The average and standard deviation of three biological replicates are plotted.
Mentions: In order to determine which of 420 FDA-approved drugs were effective at inhibiting RVFV infection, a high throughput assay was first optimized. The reporter virus, RVFV MP12-Luc, which encodes for Renilla luciferase in place of NSs (a non-structural protein that is not essential for virus replication), was utilized to measure virus replication. Vero cells were left untreated or pre-treated with DMSO or curcumin for 1 h prior to infection. Curcumin was used as a positive control for inhibition, since it has been shown to decrease RVFV infection (Narayanan et al., 2012). After pre-treatment, cells were infected with MP12-Luc at a MOI of 0.1, 1.0 or 10. One hour following infection, media containing the respective treatment was added back and cells cultured until 24 h post-infection (hpi). At this time, cells were lysed and relative luminescence determined. In both untreated and DMSO samples, there was an increase in luminescence relative to MOI. As expected, curcumin treatment decreased RVFV infection to levels that were almost undetectable (Figure 1). Z′ factors were calculated for each of the MOIs tested. The Z′ factor is used to assess the quality of an assay in order to predict if it would be useful in a high-throughput setting. A Z′ factor of 1.0 is ideal and cannot be exceeded; between 0.5 and 1.0 denotes an excellent assay; between 0 and 0.5 denotes a marginal assay; and a Z′ factor less than 0 indicates that there is too much overlap between the positive and the negative controls for the assay to be useful (Zhang et al., 1999). Based on our results, the condition chosen for the high-throughput assay was MOI 0.1 since infection at this MOI resulted in the highest Z′ factor (Z′ = 0.89).

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