Our long-term goal is to identify how chronic kidney disease (CKD) influences the cellular and molecular mechanisms underlying arteriovenous fistula (AVF) failure in patients with CKD. For many patients with CKD, hemodialysis is the preferred method of treatment;there are ~470,000 patients receiving hemodialysis treatments in U.S. The success of hemodialysis treatments requires a functioning arteriovenous access (AVF). However, in the 2 years following creation of the AVF, nearly 50% of the fistulas fail, generally due to neointima hyperplasia of vascular smooth muscle cells (SMCs). The costs of preventing or correcting AVF failure exceed $1 billion per year! Therefore, understanding the mechanisms underlying the development of the neointima could lead to a directed therapeutic strategy. We created a model of AVF in CKD mice that mimics events occurring in patients. In mice with CKD, we have uncovered clues to neointima formation in AVF. First, there is increased expression of FSP-1 in BM cells and FSP-1-positive cells and inflammatory cells in our mouse model of AVFs. Second, there is evidence of endothelial-mesenchymal transition (EnMT) in failed AVFs from CKD patients. Third, CKD activates Notch signaling and specifically, the RBP- J: transcription factor. Thus, we hypothesize that CKD-induced activation of Notch/RBP-J that promotes EnMT resulting in endothelial barrier dysfunction with infiltration of inflammatory and BM cells, leading to neointima formation. To test our hypothesis, we will create AVF in CKD and combined it with transgenic approaches. This will allow us: 1) to determine if CKD-induced EnMT accelerates endothelial barrier dysfunction and neointima formation in AVFs. 2) To identify how BM-derived cells expressing FSP-1 increase neointima formation in AVFs during CKD. 3) To investigate if RBP-J: contributes to neointima formation in CKD. Thus, our results will directly address the mechanism by which the presence of CKD accelerates neointima formation and AVF failure. In summary, results from our proposed experiments could provide a new paradigm for understanding mechanisms underlying the clinically relevant, costly problem of the failing dialysis access related to neointima formation.

Public Health Relevance

Hemodialysis requires a well-functioning arteriovenous fistula (AVF), but ~50% of AVFs fail within 2 years and their reconstruction is very costly (~$1 billion/y) To identify why AVF failure is so commonly, we created a model of AVF in mice to evaluate the influence of kidney failure and take advantage of mouse genetic models. Our proposal builds on new information that implicates specific molecular mechanisms leading to AVF failure suggesting potential therapeutic targets.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK095867-02
Application #
8635348
Study Section
Pathobiology of Kidney Disease Study Section (PBKD)
Program Officer
Flessner, Michael Francis
Project Start
2013-03-15
Project End
2018-01-31
Budget Start
2014-02-01
Budget End
2015-01-31
Support Year
2
Fiscal Year
2014
Total Cost
$340,388
Indirect Cost
$122,888
Name
Baylor College of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
Liang, Ming; Liang, Anlin; Wang, Yun et al. (2014) Smooth muscle cells from the anastomosed artery are the major precursors for neointima formation in both artery and vein grafts. Basic Res Cardiol 109:431
Wang, Yun; Liang, Anlin; Luo, Jinlong et al. (2014) Blocking Notch in endothelial cells prevents arteriovenous fistula failure despite CKD. J Am Soc Nephrol 25:773-83
Liang, Anlin; Wang, Yun; Han, Guofeng et al. (2013) Chronic kidney disease accelerates endothelial barrier dysfunction in a mouse model of an arteriovenous fistula. Am J Physiol Renal Physiol 304:F1413-20