PICK1 is Required for ASIC1‐Mediated Activation of NFATc3 in Pulmonary Arterial Smooth Muscle Cells

Abstract

The development of chronic hypoxia (CH)‐induced pulmonary hypertension is associated with increased pulmonary arterial smooth muscle cell (PASMC) Ca2+ influx through the acid sensing ion channel 1 (ASIC1) and subsequent ASIC1‐dependent activation of the Ca2+/calcineurin‐dependent transcription factor, nuclear factor of activated T‐cells isoform c3 (NFATc3). Both ASIC1 and calcineurin B have been shown to interact with protein interacting with C kinase 1 (PICK1) in neurons. Therefore, we hypothesize that PICK1 is a required scaffolding component facilitating the ASIC1‐dependent activation and nuclear translocation of NFATc3 in PASMC following CH. To test this hypothesis, we examined the interaction between PICK1/ASIC1/calcineurin B using the Duolink in situ proximity ligation assay. We found PICK1 interacts with both ASIC1 and calcineurin B in mouse PASMCs. We next determined the effect of CH (1 wk @ 380 mmHg) on PICK1 expression and found that CH increases the expression of PICK1 in mouse pulmonary arterial homogenates. We then examined the effect of PICK1 inhibition on endothelin‐1 (ET‐1; 100 nM) stimulated NFATc3 nuclear translocation. The PICK1 inhibitor, FSC231 (50 µM) abolished ET‐1 mediated nuclear translocation of NFATc3 in mouse PASMC. Together, these data show PICK1 is required for the ASIC1‐dependent activation and nuclear translocation of NFATc3 in PASMC. This ASIC1/PICK1/NFATc3 signaling complex may contribute to the vascular remodeling and increased vascular contractility associated with CH‐induced pulmonary hypertension.