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Altered AP-1/Ref-1 redox pathway and reduced proliferative response in iNOS-deficient vascular smooth muscle cells

Chyu, KY; Dimayuga, PC; Zhao, XN; Nilsson, Jan LU ; Shah, PK and Cercek, B (2004) In Vascular Medicine 9(3). p.177-183
Abstract
We previously reported that injury-induced medial vascular smooth muscle cell (VSMC) proliferation and neointima formation in carotid arteries of inducible nitric oxide synthase knockout ( iNOS KO) mice were significantly reduced compared with wild type (WT). However, the molecular pathway underlying such differences is not known. In this in vitro study, we discovered that the AP-1/Ref-1/thioredoxin signaling pathway is altered in aortic VSMC from iNOS KO mice, which leads to reduced growth response when compared with aortic VSMC from WT mice. After equal initial seeding, the cell number after 7 days in serum medium was less in iNOS KO cells compared with WT VSMC (1.2 +/- 0.6 x 10(5) vs 3.2 +/- 1.1 x 10(5); p < 0.05). Significantly more... (More)
We previously reported that injury-induced medial vascular smooth muscle cell (VSMC) proliferation and neointima formation in carotid arteries of inducible nitric oxide synthase knockout ( iNOS KO) mice were significantly reduced compared with wild type (WT). However, the molecular pathway underlying such differences is not known. In this in vitro study, we discovered that the AP-1/Ref-1/thioredoxin signaling pathway is altered in aortic VSMC from iNOS KO mice, which leads to reduced growth response when compared with aortic VSMC from WT mice. After equal initial seeding, the cell number after 7 days in serum medium was less in iNOS KO cells compared with WT VSMC (1.2 +/- 0.6 x 10(5) vs 3.2 +/- 1.1 x 10(5); p < 0.05). Significantly more iNOS KO cells remained in the G0/G1 phase compared with WT cells after 24-h serum treatment (82.6 +/- 13.7% vs 62.3 +/- 14.6%; p < 0.05) by cell-cycle analysis. Nuclear PCNA expression was also less in the iNOS KO cells, which was not affected by exogenous NO or superoxide. Superoxide generation after 24-h serum stimulation was less in the iNOS KO cells compared with WT cells. After 30-min serum stimulation, AP-1 DNA binding was reduced and a lack of increase in nuclear c-Jun protein was observed in iNOS KO VSMC. RT-PCR analysis confirmed a lack of inducible c-Jun mRNA after serum stimulation in the KO cells. In addition, KO cells had less nuclear reducing factor-1 (Ref-1) and serum-inducible thioredoxin protein expression. Reduced proliferative response of iNOS KO VSMC to serum treatment is associated with altered AP-1/Ref-1/thioredoxin pathway activation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
VSMC, Ref-1, proliferation, AP-1, thioredoxin, iNOS KO
in
Vascular Medicine
volume
9
issue
3
pages
177 - 183
publisher
SAGE Publications Inc.
external identifiers
  • pmid:15675181
  • wos:000226185300003
  • scopus:12344262038
ISSN
1477-0377
DOI
10.1191/1358863x04vm545oa
language
English
LU publication?
yes
id
1a6039c0-7908-4c43-b66e-2747a95931ed (old id 255526)
date added to LUP
2007-08-02 11:29:30
date last changed
2017-08-27 03:59:27
@article{1a6039c0-7908-4c43-b66e-2747a95931ed,
  abstract     = {We previously reported that injury-induced medial vascular smooth muscle cell (VSMC) proliferation and neointima formation in carotid arteries of inducible nitric oxide synthase knockout ( iNOS KO) mice were significantly reduced compared with wild type (WT). However, the molecular pathway underlying such differences is not known. In this in vitro study, we discovered that the AP-1/Ref-1/thioredoxin signaling pathway is altered in aortic VSMC from iNOS KO mice, which leads to reduced growth response when compared with aortic VSMC from WT mice. After equal initial seeding, the cell number after 7 days in serum medium was less in iNOS KO cells compared with WT VSMC (1.2 +/- 0.6 x 10(5) vs 3.2 +/- 1.1 x 10(5); p &lt; 0.05). Significantly more iNOS KO cells remained in the G0/G1 phase compared with WT cells after 24-h serum treatment (82.6 +/- 13.7% vs 62.3 +/- 14.6%; p &lt; 0.05) by cell-cycle analysis. Nuclear PCNA expression was also less in the iNOS KO cells, which was not affected by exogenous NO or superoxide. Superoxide generation after 24-h serum stimulation was less in the iNOS KO cells compared with WT cells. After 30-min serum stimulation, AP-1 DNA binding was reduced and a lack of increase in nuclear c-Jun protein was observed in iNOS KO VSMC. RT-PCR analysis confirmed a lack of inducible c-Jun mRNA after serum stimulation in the KO cells. In addition, KO cells had less nuclear reducing factor-1 (Ref-1) and serum-inducible thioredoxin protein expression. Reduced proliferative response of iNOS KO VSMC to serum treatment is associated with altered AP-1/Ref-1/thioredoxin pathway activation.},
  author       = {Chyu, KY and Dimayuga, PC and Zhao, XN and Nilsson, Jan and Shah, PK and Cercek, B},
  issn         = {1477-0377},
  keyword      = {VSMC,Ref-1,proliferation,AP-1,thioredoxin,iNOS KO},
  language     = {eng},
  number       = {3},
  pages        = {177--183},
  publisher    = {SAGE Publications Inc.},
  series       = {Vascular Medicine},
  title        = {Altered AP-1/Ref-1 redox pathway and reduced proliferative response in iNOS-deficient vascular smooth muscle cells},
  url          = {http://dx.doi.org/10.1191/1358863x04vm545oa},
  volume       = {9},
  year         = {2004},
}