SARS-CoV-2-ORF-3a Mediates Apoptosis Through Mitochondrial Dysfunction Modulated by the K⁺ Ion Channel

Coronavirus disease 2019 (COVID-19) causes pulmonary edema, which disrupts the lung alveoli-capillary barrier and leads to pulmonary cell apoptosis, the main cause of death. However, the molecular mechanism behind SARS-CoV-2‘s apoptotic activity remains unknown. Here, we revealed that SARS-CoV-2-ORF-3a mediates the pulmonary pathology associated with SARS-CoV-2, which is demonstrated by the fact that it causes lung tissue damage. The in vitro results showed that SARS-CoV-2-ORF-3a triggers cell death via the disruption of mitochondrial homeostasis, which is modulated through the regulation of Mitochondrial ATP-sensitive Potassium Channel (MitoK^ATP). The addition of exogenous Potassium (K⁺) in the form of potassium chloride (KCl) attenuated mitochondrial apoptosis along with the inflammatory interferon response (IFN-?) triggered by SARS-ORF-3a. The addition of exogenous K⁺ strongly suggests that dysregulation of K⁺ ion channel function is the central mechanism underlying the mitochondrial dysfunction and stress response induced by SARS-CoV-2-ORF-3a. Our results designate that targeting the potassium channel or its interactions with ORF-3a may represent a promising therapeutic strategy to mitigate the damaging effects of infection with SARS-CoV-2.