Pharmacological Inhibition of Vanin Activity Attenuates Transplant Vasculopathy in Rat Aortic Allografts.
Transplantation 2017;
100:1656-66. [PMID:
27014792 DOI:
10.1097/tp.0000000000001169]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND
Development of transplant vasculopathy is a major cause of graft loss and mortality in solid organ transplant recipients. Previous studies in mice have indicated that vanin-1, a member of the vanin protein family with pantetheinase activity, is possibly involved in neointima formation. Here, we investigated if RR6, a recently developed vanin inhibitor, could attenuate development of transplant vasculopathy.
METHODS
Abdominal allogeneic aorta transplantation from Dark Agouti to Brown Norway rats was performed. Surface neointima was quantified 2 and 4 weeks after transplantation. Systemic vanin activity was measured, and allograft leukocyte infiltration, glutathione-synthesizing capacity, matrix metalloproteinase 9 expression and neointimal smooth muscle cell (SMC) proliferation were assessed by immunohistochemistry. In vitro, the effects of RR6 on SMC proliferation (water-soluble tetrazolium-1 assay) and cytokine-induced apoptosis (flow cytometry) were investigated.
RESULTS
RR6 treatment significantly reduced systemic pantetheinase activity during the 4-week follow-up period. RR6 attenuated neointima formation 4 weeks after transplantation. Neointimal SMC proliferation and medial SMC matrix metalloproteinase 9 expression were not altered by RR6. However, RR6 significantly reduced neointimal macrophage influx that was accompanied by increased GCLC messenger RNA expression. In vitro, RR6 inhibited platelet-derived growth factor-induced SMC proliferation and protected SMCs from TNF-α-induced apoptosis.
CONCLUSIONS
Pharmacological inhibition of vanin activity attenuates development of transplant vasculopathy. This was accompanied by reduced macrophage infiltration and increased glutathione-synthesizing capacity. In vitro, RR6 reduced SMC proliferation and apoptosis that was not confirmed in vivo. Further in-depth studies are warranted to reveal the underlying mechanism(s) of RR6-induced attenuation of transplant vasculopathy in vivo.
Collapse