Design and synthesis of protoberberine analogues to alleviate LPS-induced acute lung injury by targeting HCK and blocking the HCK-NLRP3 axis.

Acute lung injury (ALI) is associated with high morbidity and mortality, but its effective treatment is lacking. Here, we synthesized 71 protoberberine derivatives, of which 35 were new, and evaluated their anti-inflammatory activity in LPS-induced RAW264.7 cells. Compound 2d showed a decent potency in reducing not only nitric oxide (NO) level with the IC50 value of 6.52 μM, but also multiple pro-inflammatory cytokine levels, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6. Meanwhile, it alleviated the historical damages in lung and decreased TNF-α, IL-1β and IL-6 levels in serum and lung tissue on LPS-induced ALI in mice. Using activity-based protein profiling technology, we found that 2d directly targeted HCK protein, and subsequently diminished the expression of NLRP3, ASC, pro-caspase-1 and pro-IL-1β in both LPS-induced RAW264.7 cells and ALI murine model. Therefore, we consider protoberberine derivatives to be a promising class of anti-ALI agents, and HCK to be a key target of these compounds in the treatment of NLRP3 related inflammatory diseases.