Non-heme iron protein: a potential target of nitric oxide in acute cardiac allograft rejection. Proc Natl Acad Sci U S A 2003 Mar 18;100(6):3125-30
Date
03/08/2003Pubmed ID
12624190Pubmed Central ID
PMC152257DOI
10.1073/pnas.0636938100Scopus ID
2-s2.0-0037453062 (requires institutional sign-in at Scopus site) 31 CitationsAbstract
We examined iron nitrosylation of non-heme protein and enzymatic activity of the Fe-S cluster protein, aconitase, in acute cardiac allograft rejection. Heterotopic transplantation of donor hearts was performed in histocompatibility matched (isografts: Lewis --> Lewis) and mismatched (allografts: Wistar-Furth --> Lewis) rats. On postoperative days (POD) 4-6, Western blot analysis and immunohistochemistry revealed inducible nitric-oxide synthase (iNOS) protein in allografts but not isografts. EPR spectroscopy revealed background signals at g = 2.003 (for semiquinone) and g = 2.02 and g = 1.94 (for Fe-S cluster protein) in isografts and normal hearts. In contrast, in allografts on POD4, a new axial signal at g = 2.04 and g = 2.02 appeared that was attributed to the dinitrosyl-iron complex formed by nitrosylation of non-heme protein. Appearance of this signal occurred at or before significant nitrosylation of heme protein. Iron nitrosylation of non-heme protein was coincidental with decreases in the nonnitrosylated Fe-S cluster signal at g = 1.94. Aconitase enzyme activity was decreased to approximately 50% of that observed in isograft controls by POD4. Treatment with cyclosporine blocked the (i) elevation of plasma nitrate + nitrite, (ii) up-regulation of iNOS protein, (iii) decrease in Fe-S cluster EPR signal, (iv) formation of dinitrosyl-iron complexes, and (v) loss of aconitase enzyme activity. Formation of dinitrosyl-iron complexes and loss of aconitase activity within allografts also was inhibited by treatment of recipients with a selective iNOS inhibitor, l-N(6)-(1-iminoethyl)lysine. This report shows targeting of an important non-heme Fe-S cluster protein in acute solid organ transplant rejection.
Author List
Pieper GM, Halligan NL, Hilton G, Konorev EA, Felix CC, Roza AM, Adams MB, Griffith OWMESH terms used to index this publication - Major topics in bold
Aconitate HydrataseAnimals
Cyclosporine
Electron Spin Resonance Spectroscopy
Enzyme Inhibitors
Graft Rejection
Heart Transplantation
Hemeproteins
Immunosuppressive Agents
Lysine
Nitric Oxide
Nitric Oxide Synthase
Nitric Oxide Synthase Type II
Nonheme Iron Proteins
Rats
Rats, Inbred Lew
Rats, Inbred WF
Rats, Sprague-Dawley
Transplantation, Homologous
Transplantation, Isogeneic
