Role of KCNK3 Dysfunction in Dasatinib-associated Pulmonary Arterial Hypertension and Endothelial Cell Dysfunction.

Pulmonary arterial (PA) 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. We discovered a gene (Potassium channel subfamily K member 3; coding for outward K channel) variant in a patient with dasatinib-associated PAH and investigated the impact of this variant on KCNK3 function. Additionally, we assessed the effects of dasatinib exposure on KCNK3 expression. In control human PA smooth muscle cells (hPASMCs) and human pulmonary endothelial cells (hPECs), we evaluated the consequences of knockdown on cell migration, mitochondrial membrane potential, ATP production, and tube formation. Using mass spectrometry, we determined the KCNK3 interactome. Patch-clamp experiments revealed that the variant represents a loss-of-function variant. Dasatinib contributed to PA constriction by decreasing KCNK3 function and expression. In control hPASMCs, knockdown promotes mitochondrial membrane depolarization and glycolytic shift. Dasatinib exposure or knockdown reduced the number of caveolae in hPECs. Moreover, knockdown in control hPECs reduced migration, proliferation, and tubulogenesis. Using proximity labeling and mass spectrometry, we identified the KCNK3 interactome, revealing that KCNK3 interacts with various proteins across different cellular compartments. We identified a novel pathogenic variant in and showed that dasatinib downregulates KCNK3, emphasizing the relationship between dasatinib-associated PAH and KCNK3 dysfunction. We demonstrated that a loss of KCNK3-dependent signaling contributes to endothelial dysfunction in PAH and glycolytic switch of hPASMCs.