title: Increased shear stress with upregulation of VEGF-A and its receptors and MMP-2, MMP-9, and TIMP-1 in venous stenosis of hemodialysis grafts.
abstract: Venous injury and subsequent venous stenosis formation are responsible for hemodialysis graft failure. Our hypothesis is that these pathological changes are in part related to changes in wall shear stress (WSS) that results in the activation of matrix regulatory proteins causing subsequent venous stenosis formation. In the present study, we examined the serial changes in WSS, blood flow, and luminal vessel area that occur subsequent to the placement of a hemodialysis graft in a porcine model of chronic renal insufficiency. We then determined the corresponding histological, morphometric, and kinetic changes of several matrix regulatory proteins including VEGF-A, its receptors, matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1, and TIMP-2. WSS was estimated by obtaining blood flow and luminal vessel area by performing phase-contrast MRI with magnetic resonance angiography in 21 animals at 1 day after graft placement and prior to death on day 3 (n = 7), day 7 (n = 7), and day 14 (n = 7). At all time points, the mean WSS at the vein-to-graft anastomosis was significantly higher than that at the control vein (P < 0.05). WSS had a bimodal distribution with peaks on days 1 and 7 followed by a significant reduction in WSS by day 14 (P < 0.05 compared with day 7) and a decrease in luminal vessel area compared with control vessels. By day 3, there was a significant increase in VEGF-A and pro-MMP-9 followed by, on day 7, increased pro-MMP-2, active MMP-2, and VEGF receptor (VEGFR)-2 (P < 0.05) and, by day 14, increased VEGFR-1 and TIMP-1 (P < 0.05) at the vein-to-graft anastomosis compared with control vessels. Over time, the neointima thickened and was composed primarily of alpha-smooth muscle actin-positive cells with increased cellular proliferation. Our data suggest that hemodialysis graft placement leads to early increases in WSS, VEGF-A, and pro-MMP-9 followed by subsequent increases in pro-MMP-2, active MMP-2, VEGFR-1, VEGFR-2, and TIMP-1, which may contribute to the development of venous stenosis.
authors.affiliation: Department of Radiology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA. misra.sanjay@mayo.edu
authors.forename: Sanjay
authors.initials: S
authors.lastname: Misra
authors.forename: Alex A
authors.initials: AA
authors.lastname: Fu
authors.forename: Alessandra
authors.initials: A
authors.lastname: Puggioni
authors.forename: Kamran M
authors.initials: KM
authors.lastname: Karimi
authors.forename: Jaywant N
authors.initials: JN
authors.lastname: Mandrekar
authors.forename: James F
authors.initials: JF
authors.lastname: Glockner
authors.forename: Luis A
authors.initials: LA
authors.lastname: Juncos
authors.forename: Bilal
authors.initials: B
authors.lastname: Anwer
authors.forename: Antonio M
authors.initials: AM
authors.lastname: McGuire
authors.forename: Debabrata
authors.initials: D
authors.lastname: Mukhopadhyay
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects* / Q000295:instrumentation; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D017364:Collagenases / Q000378:metabolism*; D003251:Constriction, Pathologic; D004195:Disease Models, Animal; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D007601:Jugular Veins / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D018810:Magnetic Resonance Angiography; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism*; D012039:Regional Blood Flow; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000378:metabolism / Q000628:therapy; D013314:Stress, Mechanical; D034421:Sus scrofa; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D042461:Vascular Endothelial Growth Factor A; D011138:Polytetrafluoroethylene; D040262:Receptors, Vascular Endothelial Growth Factor; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2; D017364:Collagenases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9