Influenza-A virus (IAV) infects yearly an estimated one billion people worldwide, resulting in 300,000-650,000 deaths. Preventive vaccination programs and
antiviral medications represent the mainstay of
therapy, but with unacceptably high morbidity and mortality rates, new targeted therapeutic approaches are urgently needed. Since inflammatory processes are commonly associated with measurable changes in the cell membrane potential (Em), we investigated whether Em hyperpolarization via
TREK-1 (K2P2.1) K+ channel activation can protect against influenza-A virus (IAV)-induced
pneumonia. We infected mice with IAV, which after 5 days caused 10-15%
weight loss and a decrease in spontaneous activity, representing a clinically relevant
infection. We then started a 3-day intratracheal treatment course with the novel
TREK-1 activating compounds
BL1249 or ML335. We confirmed
TREK-1 activation with both compounds in untreated and IAV-infected primary human alveolar epithelial cells (HAECs) using high-throughput fluorescent imaging plate reader (FLIPR) assays. In mice,
TREK-1 activation with
BL1249 and ML335 counteracted IAV-induced histological
lung injury and decrease in lung compliance and improved BAL fluid total
protein levels, cell counts, and inflammatory
IL-6, IP-10/CXCL-10, MIP-1α, and TNF-α levels. To determine whether these anti-inflammatory effects were mediated by activation of alveolar epithelial
TREK-1 channels, we studied the effects of
BL1249 and ML335 in IAV-infected HAEC, and found that
TREK-1 activation decreased IAV-induced inflammatory
IL-6, IP-10/CXCL10, and CCL-2 secretion. Dissection of
TREK-1 downstream signaling pathways and construction of
protein-
protein interaction (PPI) networks revealed NF-κB1 and
retinoic acid-inducible gene-1 (RIG-1) cascades as the most likely targets for
TREK-1 protection. Therefore,
TREK-1 activation may represent a novel therapeutic approach against IAV-induced
lung injury.