COVID-19 is caused by being infected by the new Severe Acute Respiratory Syndrome (SARS-CoV-2), for which there is no current vaccine or approved therapeutic treatment.
The infection by SARS-CoV-2 causes a dramatic increase in the levels of cytokines, generally termed a “cytokine storm”. It is this cytokine storm that causes the respiratory problems and multi-organ failures associated with severe COVID-19 cases.
The SARS-CoV-2 virus “captures” a membrane located enzyme called ACE2, whose primary function is to degrade the protein Angiotensin II (Ang II). This cuases an increase in Ang II levels which results in the activation of the IL-6/JAK/STAT signaling route. It is the continuous activation of this signaling route that leads to the cytokine storm.
For this reason, inhibitors of the IL-6/JAK/STAT signaling route might be potential treatments for COVID-19 cases. Currently, clinical trials have been initiated with an IL-6 antibody (Siltuximab) and a JAK1-2 inhibitor (Ruxolitinib). A reported inhibitor of STAT3 activation, the natural product Silibinin, is also currently recruiting patients in Spain for a clinical study.