LDN down-regulation of LPS induced ERK1/2 phosphorylation.
ERK1 and ERK2 mitogen-activated protein kinases (MAPK) play a critical
role in the regulation of cell proliferation and differentiation in
response to mitogens and other extracellular stimuli. Mitogens and
cytokines that activate MAPK in cells have been shown to activate virus
replication8. The cytokine storm is a well-known
factor that is increasing the severity and mortality in
COVID195–7. Moreover, the phosphorylation status of
ERK1/2 is positively correlated with virus load and reduced ERK1/2
phosphorylation suppressed viral replication significantly, thus reduced
viral load8. We pre-treated the cells with LDN and
exposed to LPS for 18 hours. As shown in Fig.1D . the
phosphorylation of ERK 1/2 was increased after LPS exposure which was
significantly suppressed by LDN treatment (Fig 1D ). This
finding suggests that LDN can acts as an inhibitor for ERK1/2 activation
and may reduce the infectivity of virions.