Inhibitory effects of GT0918 on acute lung injury and the molecular mechanisms of anti-inflammatory response

Coronavirus disease 2019 (COVID-19) has caused the public health crisis in the whole world. Anti-androgens block severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry and protect against severe clinical COVID-19 outcomes. GT0918, a novel androgen receptor antagonist, accelerated viral clearance and increased recovery rate in outpatients by blocking SARS-CoV-2 infection though down-regulating ACE2 and TMPRSS2 expression. Further clinical study showed that GT0918 reduced mortality rate and shortened hospital stay in hospitalized COVID-19 patients. GT0918 also exhibits protective efficacy in severe COVID-19 patient in critical care. However, the mechanism of GT0918 treatment for severe COVID-19 disease is unknown. Here, we found GT0918 decreased the expression and secretion of proinflammatory cytokines through NF-{kappa}B signaling pathway. The acute lung injury induced by LPS or Poly(I:C) was also attenuated in GT0918-treated mice, compared with vehicle control group. Moreover, GT0918 elevated the NRF2 protein level but not mRNA transcription activity. GT0918 induced proinflammatory cytokines downregulation was partially dependent on NRF2. In conclusion, our data demonstrate that GT0918 reduced cytokine release and suppressed inflammatory responses through inhibiting NF-{kappa}B signaling and activating NRF2. GT0918 is not only effective for treatment of mild to moderate COVID-19 patients, but also a potential therapeutic drug for severe COVID-19 patients by reducing the risk of cytokine storm and acute respiratory distress syndrome.