Publicación: PERI/EPICELLULAR PROTEIN DISULFIDE ISOMERASE-A1 ACTS AS AN UPSTREAM ORGANIZER OF CYTOSKELETAL MECHANOADAPTATION IN VASCULAR SMOOTH MUSCLE CELLS
Fecha
2019
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AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
Resumen
ALTHOUGH REDOX PROCESSES CLOSELY INTERPLAY WITH MECHANORESPONSES TO CONTROL VASCULAR REMODELING, REDOX PATHWAYS COUPLING MECHANOSTIMULATION TO CELLULAR CYTOSKELETAL ORGANIZATION REMAIN UNCLEAR. THE PERI/EPICELLULAR POOL OF PROTEIN DISULFIDE ISOMERASE-A1 (PECPDIA1) SUPPORTS POSTINJURY VESSEL REMODELING. USING DISTINCT MODELS, WE INVESTIGATED WHETHER PECPDIA1 COULD WORK AS A REDOX-DEPENDENT ORGANIZER OF CYTOSKELETAL MECHANORESPONSES. IN VASCULAR SMOOTH MUSCLE CELLS (VSMCS), PECPDIA1 IMMUNONEUTRALIZATION IMPAIRED STRESS FIBER ASSEMBLY IN RESPONSE TO EQUIBIAXIAL STRETCH AND, UNDER UNIAXIAL STRETCH, SIGNIFICANTLY PERTURBED CELL REPOSITIONING PERPENDICULARLY TO STRETCH ORIENTATION. DURING CYCLIC STRETCH, PECPDIA1 SUPPORTED THIOL OXIDATION OF THE KNOWN MECHANOSENSOR ?1-INTEGRIN AND PROMOTED POLARIZED COMPARTMENTALIZATION OF SULFENYLATED PROTEINS. USING TRACTION FORCE MICROSCOPY, WE SHOWED THAT PECPDIA1 ORGANIZES INTRACELLULAR FORCE DISTRIBUTION. THE NET CONTRACTILE MOMENT RATIO OF PLATELET-DERIVED GROWTH FACTOR-EXPOSED TO BASAL VSMCS DECREASED FROM 0.90 ± 0.09 (IGG-EXPOSED CONTROLS) TO 0.70 ± 0.08 AFTER PECPDI NEUTRALIZATION ( P < 0.05), TOGETHER WITH AN ENHANCED COEFFICIENT OF VARIATION FOR DISTRIBUTION OF FORCE MODULES, SUGGESTING INCREASED NOISE. MOREOVER, IN A SINGLE CELL MODEL, PECPDIA1 NEUTRALIZATION IMPAIRED MIGRATION PERSISTENCE WITHOUT AFFECTING TOTAL DISTANCE OR VELOCITY, WHEREAS SIRNA-MEDIATED TOTAL PDIA1 SILENCING DISABLED ALL SUCH VARIABLES OF VSMC MIGRATION. NEITHER EXPRESSION NOR TOTAL ACTIVITY OF THE MASTER MECHANOTRANSMITTER/REGULATOR RHOA WAS AFFECTED BY PECPDIA1 NEUTRALIZATION. HOWEVER, CYCLIC STRETCH-INDUCED FOCAL DISTRIBUTION OF MEMBRANE-BOUND RHOA WAS DISRUPTED BY PECPDI INHIBITION, WHICH PROMOTED A NONPOLARIZED PATTERN OF RHOA/CAVEOLIN-3 CLUSTER COLOCALIZATION. ACCORDINGLY, FRET BIOSENSORS SHOWED THAT PECPDIA1 SUPPORTS LOCALIZED RHOA ACTIVITY AT CELL PROTRUSIONS VERSUS PERINUCLEAR REGIONS. THUS, PECPDI ACTS AS A THIOL REDOX-DEPENDENT ORGANIZER AND NO
