Nearly 600,000 patients in the US have end stage renal disease (ESRD), a population expected to double in the next decade. The long-term goal of this current proposal and research program is to improve the care of patients with ESRD, the vast majority of who use long-term hemodialysis as their mode of renal replacement therapy. These patients require highly functioning vascular access for optimal therapeutic adequacy. Hemodialysis vascular access failure is frequently from venous stenosis secondary to neointimal hyperplasia (VNH). Our preliminary data demonstrate that outflow veins treated with AMSCs plus bevacuzimab have a significant increase in lumen vessel area and a decrease in the ratio of neointima/media + adventitia compared to controls. This effect is associated with a reduction in PPAR-? gene expression. Furthermore, we show that bevacuzimab localizes to the endothelium and not the adventitia where AMSCs are transplanted and thus will not disrupt AMSC function. VEGF-A staining of this tissue demonstrates a reduction in sub-endothelial VEGF- A where bevacuzimab is localized. We used THP-1 monocytes (cell line from acute monocytic leukemia patients) to simulate the in vivo findings of monocyte to macrophage differentiation under hypoxia, which shows that THP-1 monocytes differentiate to macrophages via an increase in PPAR-?. When monocytes are co-cultured with AMSCs plus bevacuzimab and subjected to hypoxic stress, there is a decrease in differentiation to macrophages with a reduction in PPAR-? gene expression compared to controls. In aggregate, these data support the following CENTRAL Hypothesis, which will be tested in the present revised competitive renewal: Adventitial transplantation of AMSCs to the outflow vein of AVF combined with bevacuzimab therapy reduces PPAR-? gene expression in monocytes leading to decreased macrophage differentiation and subsequent VNH formation. To test our hypothesis, we have developed three specific aims:
SPECIFIC AIM 1 : Evaluate the efficacy of AMSCs combined with bevacizumab on reducing VNH using murine and porcine models. Optimal bevacizumab combination with AMSCs will be determined in a murine model and next validated in a preclinical porcine model of AVF with CKD. The pathological and radiological evaluation will be carried out in the tissue samples to assess long-term patency and vascular remodeling.
SPECIFIC AIM 2 : Determine in vitro role(s) of AMSCs combined with bevacuzimab on reducing hypoxia-induced up-regulation of PPAR-? in monocytes leading to a reduction in macrophage differentiation. Initially, the effect of hypoxia on expression of PPAR-? in monocytes will be examined. Next, experiments will be conducted using co-culture with AMSCs to override the negative effect of PPAR-? caused by hypoxia followed by administering bevacuzimab. The outcomes will include the expression of genes responsible for inflammation and vascular remodeling as well as cellular function. These results will be validated in tissue samples from Aim 1.
SPECIFIC AIM 3 : Assess in vivo role(s) of PPAR-? using genetic approaches on VNH formation. We will use monocyte specific conditional knockout of PPAR-? in mice with AVF and CKD and examine the effect on venous stenosis formation with gene and protein expression of pro-inflammatory cytokines. Next, we will determine the role(s) of bevacuzimab plus monocyte specific conditional knockout of PPAR-? mice on VNH.

Public Health Relevance

Nearly 600,000 patients in the United States have end stage renal disease (ESRD), a population expected to double in the next decade. The long-term goal of this current proposal and my research program is to improve the care of patients with ESRD, the vast majority of who use long-term hemodialysis as their mode of renal replacement therapy. Our decades of clinical experience with dialysis access combined with the extensive body of literature demonstrate that venous stenosis formation is the ?Achilles heel? to long-term durability of arteriovenous fistula. Our strong preliminary data suggest that adipose derived mesenchymal stem cells therapy combined with bevacuzimab at the time of fistula creation may represent the solution dialysis patients desperately need to increase durability and prolong vascular access function. The results from this proposal will show that we can achieve long-term protection from venous stenosis formation and thus facilitate designing future clinical trials in dialysis access patients.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL098967-06A1
Application #
9185109
Study Section
Medical Imaging Study Section (MEDI)
Program Officer
Reid, Diane M
Project Start
2010-02-01
Project End
2020-04-30
Budget Start
2016-07-01
Budget End
2017-04-30
Support Year
6
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Mayo Clinic, Rochester
Department
Type
DUNS #
006471700
City
Rochester
State
MN
Country
United States
Zip Code
55905
Yang, Binxia; Kilari, Sreenivasulu; Brahmbhatt, Akshaar et al. (2017) CorMatrix Wrapped Around the Adventitia of the Arteriovenous Fistula Outflow Vein Attenuates Venous Neointimal Hyperplasia. Sci Rep 7:14298
Miller, Andrew J; Takahashi, Edwin A; Harmsen, William S et al. (2017) Treatment of Superficial Femoral Artery Restenosis. J Vasc Interv Radiol 28:1681-1686
Takahashi, Edwin A; Kallmes, David F; Fleming, Chad J et al. (2017) Predictors and Outcomes of Postcontrast Acute Kidney Injury after Endovascular Renal Artery Intervention. J Vasc Interv Radiol 28:1687-1692
Brahmbhatt, Akshaar; Misra, Sanjay (2016) The Biology of Hemodialysis Vascular Access Failure. Semin Intervent Radiol 33:15-20
Yang, Binxia; Brahmbhatt, Akshaar; Nieves Torres, Evelyn et al. (2016) Tracking and Therapeutic Value of Human Adipose Tissue-derived Mesenchymal Stem Cell Transplantation in Reducing Venous Neointimal Hyperplasia Associated with Arteriovenous Fistula. Radiology 279:513-22
Janardhanan, Rajiv; Yang, Binxia; Kilari, Sreenivasulu et al. (2016) The Role of Repeat Administration of Adventitial Delivery of Lentivirus-shRNA-Vegf-A in Arteriovenous Fistula to Prevent Venous Stenosis Formation. J Vasc Interv Radiol 27:576-83
Heideman, Paul P; Rajebi, Mohammad Reza; McKusick, Michael A et al. (2016) Impact of Chronic Kidney Disease on Clinical Outcomes of Endovascular Treatment for Femoropopliteal Arterial Disease. J Vasc Interv Radiol 27:1204-14
Brahmbhatt, Akshaar; Misra, Sanjay (2016) Techniques in Vascular and Interventional Radiology Drug Delivery Technologies in the Superficial Femoral Artery. Tech Vasc Interv Radiol 19:145-52
Lee, Timmy; Misra, Sanjay (2016) New Insights into Dialysis Vascular Access: Molecular Targets in Arteriovenous Fistula and Arteriovenous Graft Failure and Their Potential to Improve Vascular Access Outcomes. Clin J Am Soc Nephrol 11:1504-12
Misra, Sanjay; Khosla, Ankaj; Allred, Jake et al. (2016) Mortality and Renal Replacement Therapy after Renal Artery Stent Placement for Atherosclerotic Renovascular Disease. J Vasc Interv Radiol 27:1215-24

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