A small-molecule HSP90 inhibitor, NVP-HSP990, alleviates rotavirus infection

Rotavirus (RV) infection remains a leading cause of hospitalization and mortality among infants and young children. Despite global implementation of RV vaccines, hundreds of thousands of infants and young children still succumb to this disease each year due to ineffective treatment. In this study, we demonstrated that NVP-HSP990, a novel small-molecule heat shock protein 90 (HSP90) inhibitor, inhibited RV infection with a fascinatingly higher selectivity index compared to conventional HSP90 inhibitors like geldanamycin and its derivative tanespimycin (17-allylamino-17-demethoxygeldanamycin [17-AAG]). NVP-HSP990 effectively inhibited RV replication in vitro without blocking the initial establishment of infection. NVP-HSP990 restored host gene expression in most KEGG pathways disrupted by RV infection in Caco-2 cells, except some inflammatory pathways (such as IL-17 and TNF pathways). NVP-HSP990 significantly inhibited RV-induced activation of the MAPK pathway and prevented the disruption of tight junctions in Caco-2 cells. More importantly, NVP-HSP990 effectively suppressed RV infection in BALB/c suckling mice and significantly alleviated RV-induced diarrhea.IMPORTANCERotavirus (RV) infection poses a global health threat with an urgent need for targeted antiviral therapies. Here, we identified NVP-HSP990 as a next-generation HSP90 inhibitor with exceptional translational potential against RV infection. Compared to conventional HSP90 inhibitors, NVP-HSP990 demonstrated markedly enhanced anti-RV selectivity. NVP-HSP990 effectively reversed dysregulation of key host pathways in RV infection while selectively modulating pro-inflammatory responses, thereby balancing antiviral and immunopathological outcomes. NVP-HSP990 also blocked MAPK-driven tight junction disruption to preserve intestinal barrier integrity. As a result, NVP-HSP990 significantly alleviated the severity of RV-induced diarrhea. Given its excellent oral efficacy and systemic penetration previously reported, NVP-HSP990 emerges as a promising HSP90-targeted candidate capable of addressing both intestinal and possible extraintestinal RV infections, which also repositions HSP90 inhibition as a viable strategy in RV management.