Ziqing Luo

Background: Influenza A virus (IAV) is a major human pathogen, contributing to substantial morbidity and mortality during seasonal outbreaks and pandemics. Human infection with IAV can lead to pneumonia and acute respiratory distress syndrome (ARDS), and numerous clinical and basic research studies have established an association between IAV and pulmonary fibrosis (PF). However, the treatment of IAV-induced PF fibrosis has not been studied and discussed. Methods: An IAV-induced PF mouse model was established. Herbacetin (HBT) was identified as the most effective compound in the in vitro study of seven components of Rhodiola rosea L. (R. rosea L.). The effect of HBT on IAV-induced lung injury and PF was evaluated in vivo and in vitro. The binding between HBT and neuraminidase (NA) protein was investigated by biological layer interferometry (BLI) and cell thermal shift assay (CETSA). Results: Following IAV infection, the TGF-β/Smad3 pathway is activated, leading to the upregulation of fibrosis-related proteins that promote fibrosis. HBT exhibited a significant ability to reduce influenza virus-induced lung injury and fibrosis both in vitro and in vivo. Mechanistically, HBT binds to the NA protein of the influenza virus, reducing viral infection and the activation of the TGF-β/Smad3 pathway, thereby mitigating the formation of lung injury and PF. Conclusions: HBT represents a promising therapeutic agent for modulating influenza virus-induced lung injury and PF, marking a significant step toward the development of effective treatments for influenza-induced PF.

Zika virus (ZIKV) is an RNA-enveloped virus that belongs to the Flavivirus genus, and ZIKV infections potentially induce severe neurodegenerative diseases and impair male fertility. Palmitoylation is an important post-translational modification of proteins that is mediated by a series of DHHC-palmitoyl transferases, which are implicated in various biological processes and viral infections. However, it remains to be investigated whether palmitoylation regulates ZIKV infections. In this study, we initially observed that the inhibition of palmitoylation by 2-bromopalmitate (2-BP) enhanced ZIKV infections, and determined that the envelope protein of ZIKV is palmitoylated at Cys308. ZDHHC11 was identified as the predominant enzyme that interacts with the ZIKV envelope protein and catalyzes its palmitoylation. Notably, ZDHHC11 suppressed ZIKV infections in an enzymatic activity-dependent manner and ZDHHC11 knockdown promoted ZIKV infection. In conclusion, we proposed that the envelope protein of ZIKV undergoes a novel post-translational modification and identified a distinct mechanism in which ZDHHC11 suppresses ZIKV infections via palmitoylation of the ZIKV envelope protein.