Monocyte chemoattractant Proteins and Vascular Injury

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PROJECT SUMMARY/ABSTRACT In 2017, ~750K Americans were diagnosed with end-stage kidney disease (ESKD), which rises 3% yearly. 87% will have renal replacement therapy with hemodialysis (HD), with preferred vascular access through arteriovenous fistula (AVF). AVFs have ~62% year patency due to venous stenosis (VS) and neointimal hyperplasia (VNH) causing reduced blood flow and suboptimal HD which is treated with percutaneous transluminal angioplasty (PTA) at >$3B/yr. Monocyte and macrophage recruitment occurs to the injured vessel wall after PTA of stenotic arteriovenous fistulas (AVF) through increased expression of MCP-1 leading to VS/VNH. Bindarit is an oral selective inhibitor of MCP-1, - 2, and -3 and we encapsulated it in polylactic-co-glycolic acid (PLGA) nanoparticles embedded in a thermosensitive Pluronic F127 hydrogel (BN NP) for periadventitial delivery to the outflow vein to test in this proposal. Scanning electron microscope and dynamic light scattering were used to characterize the BN NP and control nanoparticles (NP C). Liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used to study drug release kinetics. Immediately after PTA, in a murine model of AVF stenosis, BN NP or NP C was administrated to the periadventitia of outflow veins. Animals were sacrificed 3 and 21 days later for gene expression, histomorphometric, and immunohistochemical analyses. Doppler ultrasound was performed weekly. There was no difference in the size and storage modulus of BN NP compared controls. Pharmacokinetic analysis demonstrated increased drug release from BN NP when compared to controls. BN NP treated vessels had reduced MCP-1, MCP-2 and MCP-3 gene and protein levels, reduced CCR2, increased FABP4/IL8, macrophage/monocyte abundance, proinflammatory cytokines, reduced CD4 (+) cells, reduced endothelial inflammation, and venous fibrosis resulting in positive vascular remodeling and improved patency with reduced VS/VNH. There was increased peak velocity 21 days after PTA in the BN NP group. Periadventitial administration of BN NP to the outflow vein after PTA results in decreased VS/VNH. Central Hypothesis. Periadventitial delivery of Bindarit NPs to AVF outflow vein after PTA decreases Mcp-1, -2, -3, CCR2 expression with increased FABP4/IL8 leading to less immune, macrophage cell infiltration with reduction in smooth muscle cells, fibrosis, and VS/VNH. We propose three specific aims: Aim 1: Determine how Bindarit NPs reduce MCP-1, -2, and -3 leading to decreased monocyte to macrophage differentiation, migration, proliferation, leukocyte chemoattraction by endothelial cells and inflammatory cytokine expression. Aim 2: Assess the role(s) of Bindarit NPs on CCR2 and FABP4/IL8 on reducing VS/VNH after PTA of stenotic AVFs. Aim 3: Ascertain the safety and efficacy of Bindarit NPs on reducing VS/VNH after PTA in pigs with CKD.