| First Author | Wei X | Year | 2020 |
| Journal | Circ Res | Volume | 127 |
| Issue | 2 | Pages | 249-265 |
| PubMed ID | 32233916 | Mgi Jnum | J:302677 |
| Mgi Id | MGI:6509409 | Doi | 10.1161/CIRCRESAHA.120.316752 |
| Citation | Wei X, et al. (2020) Endothelial Palmitoylation Cycling Coordinates Vessel Remodeling in Peripheral Artery Disease. Circ Res 127(2):249-265 |
| abstractText | RATIONALE: Peripheral artery disease, common in metabolic syndrome and diabetes mellitus, responds poorly to medical interventions and is characterized by chronic vessel immaturity leading to lower extremity amputations. OBJECTIVE: To define the role of reversible palmitoylation at the endothelium in the maintenance of vascular maturity. METHODS AND RESULTS: Endothelial knockout of the depalmitoylation enzyme APT-1 (acyl-protein thioesterase 1) in mice impaired recovery from chronic hindlimb ischemia, a model of peripheral artery disease. Endothelial APT-1 deficiency decreased fibronectin processing, disrupted adherens junctions, and inhibited in vitro lumen formation. In an unbiased palmitoylation proteomic screen of endothelial cells from genetically modified mice, R-Ras, known to promote vessel maturation, was preferentially affected by APT-1 deficiency. R-Ras was validated as an APT-1 substrate, and click chemistry analyses demonstrated increased R-Ras palmitoylation in cells with APT-1 deficiency. APT-1 enzyme activity was decreased in endothelial cells from db/db mice. Hyperglycemia decreased APT-1 activity in human umbilical vein endothelial cells, due, in part, to altered acetylation of the APT-1 protein. Click chemistry analyses demonstrated increased R-Ras palmitoylation in the setting of hyperglycemia. Altered R-Ras trafficking, increased R-Ras palmitoylation, and fibronectin retention were found in diabetes mellitus models. Loss of R-Ras depalmitoylation caused by APT-1 deficiency constrained R-Ras membrane trafficking, as shown by total internal reflection fluorescence imaging. To rescue cellular phenotypes, we generated an R-Ras molecule with an inserted hydrophilic domain to circumvent membrane rigidity caused by defective palmitoylation turnover. This modification corrected R-Ras membrane trafficking, restored fibronectin processing, increased adherens junctions, and rescued defective lumen formation induced by APT-1 deficiency. CONCLUSIONS: These results suggest that endothelial depalmitoylation is regulated by the metabolic milieu and controls plasma membrane partitioning to maintain vascular homeostasis. |
