The Antimalaria Drug Artesunate Inhibits Porcine Reproductive and Respiratory Syndrome Virus Replication by Activating AMPK and Nrf2/HO-1 Signaling Pathways

Abstract

Porcine Reproductive and Respiratory Syndrome virus (PRRSV) causes significant economic losses to the pork industry worldwide. Currently, vaccine strategies provide limited protection against PRRSV transmission, and no effective drug is commercially available. Therefore, there is an urgent need to develop novel antiviral strategies to prevent PRRSV pandemics. This study showed that artesunate (AS), one of the antimalarial drugs, potently suppressed PRRSV replication in Marc-145 cells and ex vivo primary porcine alveolar macrophages (PAMs) at micromolar concentrations. Furthermore, we demonstrated that this suppression was closely associated with AS-activated AMPK (energy homeostasis) and Nrf2/HO-1 (inflammation) signaling pathways. AS treatment promoted p-AMPK, Nrf2 and HO-1 expression, and thus inhibited PRRSV replication in Marc-145 and PAM cells in a time- and dose-dependent manner. These effects of AS were reversed when AMPK or HO-1 gene was silenced by siRNA. In addition, we demonstrated that AMPK works upstream of Nrf2/HO-1 as its activation by AS is AMPK-dependent. Adenosine phosphate analysis showed that AS activates AMPK via improving AMP/ADP:ATP ratio rather than direct interaction with AMPK. Altogether, our findings indicate that AS could be a promising novel therapeutics for controlling PRRSV and that its anti-PRRSV mechanism, which involves the functional link between energy homeostasis and inflammation suppression pathways, may provide opportunities for developing novel antiviral agents. Importance Porcine reproductive and respiratory syndrome virus (PRRSV) infections have been continuously threatened the pork industry worldwide. Vaccination strategies provide very limited protection against PRRSV infection, and no effective drug is commercially available. We show that artesunate (AS), one of the antimalarial drugs, is a potent inhibitor against PRRSV replication in Marc-145 cells and ex vivo primary porcine alveolar macrophages (PAMs). Furthermore, we demonstrate that AS inhibits PRRSV replication via activation of AMPK-dependent Nrf2/HO-1 signaling pathways, revealing a novel link between energy homeostasis (AMPK) and inflammation suppression (Nrf2/HO-1) during viral infection. Therefore, we believe that AS may be a promising novel therapeutics for controlling PRRSV, and its anti-PRRSV mechanism may provide a potential strategy to develop novel antiviral agents.

Brequinar inhibits African swine fever virus replication in vitro by activating ferroptosis

“…PAMs were cultured in 24-well plates for 4 h. As previously published [ 33 ], ASFV (MOI = 1) and brequinar were mixed at 37°C for 1 h, and then separation of ASFV and brequinar by ultrafiltration centrifugation. ASFV particles collected in the ultrafiltration tube were washed twice with pre-cooled fresh culture medium, and then resuspended and added to the PAMs.…”

Theaflavin inhibits African swine fever virus replication by disrupting lipid metabolism through activation of the AMPK signaling pathway in virto

“…Previous studies have shown that TF upregulates the AMPK pathway ( Qu et al., 2021 ), and Long et al. found that artesunate disrupts PRRSV proliferation by activating the AMPK signaling pathway ( Long et al., 2022 ). Meanwhile, Xie and colleagues found that activated AMPK inhibits HBV replication by promoting the degradation of autophagy ( Xie et al., 2016 ).…”

“…Emerging evidence suggests that promoting AMPK expression can inhibit viral replication. For example, Long and colleagues demonstrated that artesunate inhibited PRRSV replication in MARC-145 and PAMs by upregulating the AMPK signaling pathway ( Long et al., 2022 ). Moreover, Singh and colleagues also found that an AMPK agonist inhibited ZIKV replication, and the activation of AMPK enhanced the expression of antiviral-specific factors ( Singh et al., 2020 ).…”

Toosendanin activates caspase-1 and induces maturation of IL-1β to inhibit type 2 porcine reproductive and respiratory syndrome virus replication via an IFI16-dependent pathway

“…However, the vaccines usually provide limited protection against PRRS infection [5,6] due to high mutation rate of PRRSV and that the circulation of multiple subtypes [7]. Some compounds may act as potential anti-PRRSV agents, such as artesunate [8], glycyrrhizin [9], xanthohumol [10], platycodin D [11], (−)-epigallocatechin-3-gallate [12], and flavaspidic acid AB [13]. Nevertheless, no effective drugs are commercially available for the treatment of PRRSV infection.…”