title: Nitric oxide may inhibit neointimal hyperplasia by decreasing isopeptidase T levels and activity in the vasculature.
abstract: OBJECTIVE
  Isopeptidase T is a cysteine protease deubiquitinating enzyme that hydrolyzes unanchored polyubiquitin chains to free monoubiquitin. Nitric oxide (NO) decreases 26S proteasome activity in vascular smooth muscle cells (VSMCs) and inhibits neointimal hyperplasia in animal models. As NO can cause S-nitrosylation of active-site cysteines, we hypothesize that NO inhibits isopeptidase T activity through S-nitrosylation. Because accumulation of polyubiquitin chains inhibits the 26S proteasome, this may be one mechanism through which NO prevents neointimal hyperplasia.
  
  
  METHODS
  To investigate our hypothesis, we examined the effect of NO on isopeptidase T activity, levels, and localization in VSMCs in vitro and in a rat carotid balloon injury model in vivo.
  
  
  RESULTS
  NO inhibited recombinant isopeptidase T activity by 82.8% (t = 60 minutes, P < .001 vs control). Dithiothreitol and glutathione (5 mmol/L) both significantly reversed NO-mediated inhibition of isopeptidase T activity (P < .001). NO caused a time-dependent increase in S-nitrosylated isopeptidase T levels in VSMCs, which was reversible with dithiothreitol, indicating that isopeptidase T undergoes reversible S-nitrosylation on exposure to NO in vitro. Although NO did not affect isopeptidase T levels or subcellular localization in VSMCs in vitro, it decreased isopeptidase T levels and increased ubiquitinated proteins after balloon injury in vivo.
  
  
  CONCLUSIONS
  Local administration of NO may prevent neointimal hyperplasia by inhibiting isopeptidase T levels and activity in the vasculature, thereby inhibiting the 26S proteasome in VSMCs. These data provide additional mechanistic insights into the ability of NO to prevent neointimal hyperplasia after vascular interventions.
authors: Division of Vascular Surgery, Northwestern University, Chicago, IL 60611, USA.
authors: Nick D
authors: ND
authors: Tsihlis
authors: Muneera R
authors: MR
authors: Kapadia
authors: Ashley K
authors: AK
authors: Vavra
authors: Walker D
authors: WD
authors: Flannery
authors: Christopher S
authors: CS
authors: Oustwani
authors: Qun
authors: Q
authors: Jiang
authors: Melina R
authors: MR
authors: Kibbe
mesh_terms: D000818:Animals; D020212:Carotid Artery Injuries / Q000201:enzymology* / Q000473:pathology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004229:Dithiothreitol / Q000494:pharmacology; D015536:Down-Regulation; D010450:Endopeptidases / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D006965:Hyperplasia; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D058426:Neointima; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000378:metabolism; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D013997:Time Factors; D054875:Ubiquitination; D057772:Vascular System Injuries / Q000201:enzymology* / Q000473:pathology
chemical_list: D020030:Nitric Oxide Donors; D011994:Recombinant Proteins; D009569:Nitric Oxide; D026423:S-Nitroso-N-Acetylpenicillamine; D010450:Endopeptidases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; C091939:ubiquitin isopeptidase; D005978:Glutathione; D004229:Dithiothreitol
references: Circulation. 2002 Jan 29;105(4):483-9
references: 11815432
references: Curr Opin Chem Biol. 2004 Dec;8(6):610-6
references: 15556404
references: J Biol Chem. 1992 Jan 15;267(2):719-27
references: 1309773
references: Circ Res. 2007 Oct 26;101(9):865-74
references: 17823377
references: FEBS Lett. 2002 Nov 20;531(3):469-74
references: 12435595
references: Nitric Oxide. 2009 Jun;20(4):279-88
references: 19233305
references: Am J Physiol Heart Circ Physiol. 2008 Dec;295(6):H2388-98
references: 18931034
references: Gene. 1998 Sep 14;217(1-2):101-6
references: 9841226
references: J Biol Chem. 1990 May 25;265(15):8354-7
references: 2160452
references: J Biol Chem. 2009 Feb 20;284(8):5030-41
references: 19098288
references: Nitric Oxide. 2012 Jun 30;27(1):50-8
references: 22561112
references: J Am Coll Surg. 1998 Sep;187(3):295-306
references: 9740187
references: J Vasc Surg. 2008 Jan;47(1):173-82
references: 18178471
references: J Vasc Surg. 2001 Dec;34(6):1016-22
references: 11743554
references: Science. 1989 Mar 24;243(4898):1576-83
references: 2538923
references: Circ Res. 2010 Mar 5;106(4):633-46
references: 20203313
references: Ann Vasc Surg. 2001 Nov;15(6):628-33
references: 11769143
references: Cell Mol Life Sci. 2008 Aug;65(15):2397-406
references: 18438605
references: Biochemistry. 1995 Nov 7;34(44):14535-46
references: 7578059
references: Circulation. 1997 Mar 4;95(5):1269-77
references: 9054859
references: Curr Opin Chem Biol. 2003 Oct;7(5):534-9
references: 14580555
references: Nat Struct Mol Biol. 2005 Aug;12(8):708-14
references: 16007098
references: Am J Physiol Cell Physiol. 2002 Mar;282(3):C625-34
references: 11832348
references: Mol Cell Biol. 1994 Aug;14(8):5501-9
references: 8035826
references: EMBO J. 1997 Aug 15;16(16):4826-38
references: 9305625
references: J Vasc Surg. 2000 Jun;31(6):1214-28
references: 10842159
references: Genome Res. 1996 Apr;6(4):314-26
references: 8723724
references: Circ Res. 2003 Apr 18;92(7):715-24
references: 12649263
references: Free Radic Biol Med. 2008 Jan 1;44(1):73-81
references: 18045549