KCNK3 channel dysregulation in PAH

Introduction. Pulmonary arterial hypertension (PAH) is a severe cardiopulmonary disease that may be triggered by exposure to drugs such as dasatinib or facilitated by genetic predispositions. The incidence of dasatinib-associated PAH is estimated at 0.45%, suggesting individual predispositions. The mechanisms of dasatinib-associated PAH are still incomplete. This study studied the link between dasatinib and KCNK3 and the consequences of dasatinib exposure or KCNK3 knockdown in pulmonary endothelial cells (PECs) and pulmonary arterial smooth muscle cells (PASMC). Methods. We discovered a KCNK3 gene variant in a patient with dasatinib-associated PAH and investigated the impact of this variant on KCNK3 function using patch-clamp analysis. Additionally, we assessed the effects of dasatinib exposure on KCNK3 expression and function in human and rat pulmonary arteries. In control-human PASMCs and PECs (hPASMCs and hPECs), we evaluated the consequence of KCNK3 knockdown on cell migration, mitochondrial membrane potential, ATP production, and in vitro tube formation. Using mass spectrometry, we determined the KCNK3 interactome. Results. Patch-clamp revealed that the identified KCNK3 variant represents a loss-of-function variant. Dasatinib contributed to pulmonary artery constriction by decreasing KCNK3 function and expression. In control-hPASMCs, KCNK3 knockdown promotes mitochondrial membrane depolarization and glycolytic shift. Additionally, dasatinib exposure or KCNK3 knockdown reduced the number of caveolae in PECs. Moreover, KCNK3 knockdown in control-hPECs reduced migration, proliferation, and in vitro tubulogenesis. Lastly, using proximity ligation assay and mass spectrometry, we identified the KCNK3 interactome revealing that KCNK3 interaction with various proteins across different cellular compartments could impact these cellular functions. Conclusion. We identified a novel pathogenic variant in the KCNK3 gene, suggesting that KCNK3 gene variations could also influence the development of dasatinib-associated PAH. Our results support that one of the mechanisms of action of dasatinib-associated PAH results from the downregulation of KCNK3.