Abstract
Abstract
Background and Purpose
Sinapine thiocyanate (ST) has effects in treating respiratory diseases. Its action in hypoxic pulmonary hypertension (HPH) remains poorly understood. We evaluated the potential of ST on HPH and its molecular mechanism.
Experimental Approach
ST was evaluated on a rat model HPH. Single‐cell RNA sequencing (scRNA‐seq) identified ST‐modulated cell clusters. ST regulation on endothelial dysfunction‐induced neutrophil migration
in vivo
and
in vitro
was studied. Molecular docking, cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) analysis were used to identify targets of ST. The molecular mechanism by which ST modulates endothelial cell dysfunction through gene silencing experiments was also investigated.
Key Results
ST significantly reduced pulmonary arterial pressure in HPH rats and alleviated pathological changes in lung tissue. scRNA‐seq showed that ST markedly decreased the proportion of neutrophils, down‐regulated the expression of their cell migration‐related genes and the gene expression of chemokines in endothelial cells.
In vivo
experimental indicated that ST reduced neutrophil infiltration in lung tissue and lowered inflammatory cytokine levels in bronchoalveolar lavage fluid. Further
in vitro
studies indicated that ST reduced neutrophil migration by inhibiting hypoxia‐induced endothelial dysfunction. ST inhibited P65 phosphorylation‐mediated endothelial dysfunction by targeting chloride intracellular channel 4 (CLIC4). Inhibiting CLIC4 activation through blocking the cascade reaction of CLIC4 up‐regulation and activation induced by pro‐inflammatory cytokines. Silencing endothelial cell CLIC4 abolishes ST inhibitory effects on inflammatory cytokine expression and regulatory impact on P65 activation.
Conclusions and Implications
ST targeted CLIC4 inhibits NF‐κB p65 activation would have therapeutic effects against HPH.