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Martin-Acebes, M. A.

Publications and source records attributed to Martin-Acebes, M. A..

3 recordsLinked to original sources

Sirtuin 1 Is Required for Optimal Mammarenavirus Multiplication

Mammarenaviruses (MaAv) cause persistent infections in diverse rodent reservoirs worldwide and several are zoonotic pathogens with an important public-health burden in their endemic regions. Moreover, the globally distributed MaAv lymphocytic choriomeningitis virus (LCMV) is an underrecognized pathogen of clinical significance in congenital infections and immunocompromised individuals. The lack of FDA-approved vaccines or antivirals for MaAv infections underscores the urgent need for novel anti-MaAv therapeutic strategies. Neutral sphingomyelinase 2 (nSMase2) was recently identified as a host factor contributing to LCMV multiplication, and its inhibitor cambinol exhibits dose-dependent antiviral activity against LCMV but the underlying mechanisms remain undefined. Here, we show that cambinol disrupts multiple stages of the LCMV life cycle. Cambinol inhibits the pH-dependent fusion event mediated by MaAv glycoprotein, a step required for completion of virus cell entry. It also reduces viral ribonucleoprotein (vRNP)-directed genome replication and transcription and impairs the budding activity of the virus matrix Z protein. Cambinol also inhibits sirtuins 1 and 2 (Sirt-1 and Sirt-2), two NAD+-dependent protein deacetylases with pleiotropic roles in cellular metabolism and stress responses, raising the question of whether cambinol anti-LCMV activity reflects nSMase2 inhibition alone or also involves sirtuin-dependent pathways. LCMV multiplication was significantly reduced in SIRT1, but not SIRT2, knockout (KO) cells, uncovering a pro-viral role for Sirt-1 in the LCMV life cycle. Consistent with this finding, LCMV vRNP activity and production of infectious progeny were reduced in SIRT1 KO cells. These findings identify Sirt-1 as a host factor required for optimal LCMV multiplication. Sirt-1 inhibitors are in clinical development for oncological and neurological indications, raising the possibility of repurposing Sirt-1 inhibitors as host-directed antivirals (HDAs) against human pathogenic MaAv. Abstract figure O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/740332v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@d53c5forg.highwire.dtl.DTLVardef@16ea861org.highwire.dtl.DTLVardef@1f09addorg.highwire.dtl.DTLVardef@1472e6b_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

Mammarenavirus-Induced Remodeling of the Cellular Lipid Landscape Reveals Sphingolipid Metabolism as a Novel Target for Antiviral Intervention

Several mammarenaviruses (MaAv) cause severe and often life-threatening disease in humans and represent major public health threats in their endemic regions. Lassa (LASV) and Junin (JUNV) MaAv, endemic to Western Africa and the Argentine Pampas, respectively, are etiologic agents of viral hemorrhagic fevers associated with high morbidity and mortality. In addition, the globally distributed MaAv lymphocytic choriomeningitis virus (LCMV) is an underrecognized human pathogen capable of causing severe congenital disease and fatal infections in immunocompromised individuals. Despite their public health importance, no FDA-approved vaccines or virus-specific antiviral therapies exist to prevent and treat human MaAv infections. Current treatment relies on the off-label use of ribavirin whose therapeutic efficacy remains controversial. These findings underscore the urgent need to develop effective antiviral strategies against human pathogenic MaAv. Here, we investigated the impact of LCMV infection on host lipid metabolism using an integrated transcriptomic and lipidomic approach. Our data reveal extensive time-dependent remodeling of the cellular lipid landscape, with particularly prominent alterations in sphingolipid and fatty acid metabolic pathways. Functional interrogation of these pathways using pharmacological inhibitors identified acetyl-CoA carboxylase (ACC) and neutral sphingomyelinase 2 (nSMase2) as host factors contributing to efficient viral replication. Notably, inhibition of nSMase2 reduced infectious virus production by 2 logs of infectious virus. Our findings showed that LCMV reprograms host lipid metabolism to facilitate infection and identified sphingolipid turnover as a promising target for host-directed antiviral strategies against MaAv infections.

microbiology↗

Pharmacological elevation of cellular dihydrosphingomyelin provides a novel antiviral strategy against West Nile virus infection

Flavivirus life cycle is strictly dependent on cellular lipid metabolism. Polyphenols like gallic acid and its derivatives are promising lead compounds for new therapeutic agents as they can exert multiple pharmacological activities, including the alteration of lipid metabolism. The evaluation of our own collection of polyphenols against West Nile virus, a representative medically relevant flavivirus, led to the identification of N,N'-(dodecane-1,12-diyl)bis(3,4,5-trihydroxybenzamide) and its 2,3,4-trihydroxybenzamide regioisomer as selective antivirals with low cytotoxicity and high antiviral activity (EC50 of 2.2 and 0.24 M, respectively in Vero cells; EC50 of 2.2 and 1.9 M, respectively in SH-SY5Y cells). These polyphenols also inhibited the multiplication of other flaviviruses, namely Usutu, dengue, and Zika viruses, exhibiting lower antiviral or negligible antiviral activity against other RNA viruses. The mechanism underlying their antiviral activity against WNV involved the alteration of sphingolipid metabolism. These compounds inhibited ceramide desaturase (Des1) promoting the accumulation of dihydrosphingomyelin (dhSM), a minor component of cellular sphingolipids with important roles on membrane properties. Addition of exogenous dhSM, or Des1 blockage by using the reference inhibitor GT-11, confirmed the involvement of this pathway in WNV infection. These results unveil the potential of novel antiviral strategies based on the modulation of the cellular levels of dhSM and Des1 activity for the control of flavivirus infection.

microbiology↗