|
|
||||||||
INFLAMMATION/IMMUNITY/MEDIATORS
1Department of Surgery, Children's Hospital of Pittsburgh and the University of Pittsburgh School of Medicine, Pittsburgh; and 2Department of Hematology and Oncology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, 15213
Submitted 24 September 2002 ; accepted in final form 26 June 2003
Overproduction of nitric oxide (NO) or its toxic metabolite, peroxynitrite (ONOO-), after endotoxemia promotes gut barrier failure, in part, by inducing enterocyte apoptosis. We hypothesized that ONOO- may also inhibit enterocyte proliferation by disrupting the Src tyrosine kinase signaling pathway, thereby blunting repair of the damaged mucosa. We examined the effect of ONOO- on enterocyte proliferation and Src kinase activity. Sprague-Dawley rats were challenged with LPS or saline, whereas intestinal epithelial cell line cells were treated with ONOO- or decomposed ONOO- in vitro. Enterocyte proliferation in vivo and in vitro was measured by 5-bromo-2'-deoxyuridine (BrdU) or [3H]thymidine incorporation. Src kinase activity in cell lysates was determined at various times. LPS challenge in vivo and ONOO- treatment in vitro inhibited enterocyte proliferation. ONOO- treatment blunted the activity of Src and its downstream target, focal adhesion kinase, in a time-dependent manner. ONOO- blocked mitogen (FBS, EGF)-induced enterocyte proliferation and Src phosphorylation while increasing Src nitration. Thus ONOO- may promote gut barrier failure not only by inducing enterocyte apoptosis but also by disrupting signaling pathways involved in enterocyte proliferation.
cell signaling; focal adhesion kinase; nitrotyrosine; lipopolysaccharide
This article has been cited by other articles:
![]() |
S. Cetin, C. L. Leaphart, J. Li, I. Ischenko, M. Hayman, J. Upperman, R. Zamora, S. Watkins, H. R. Ford, J. Wang, et al. Nitric oxide inhibits enterocyte migration through activation of RhoA-GTPase in a SHP-2-dependent manner Am J Physiol Gastrointest Liver Physiol, May 1, 2007; 292(5): G1347 - G1358. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G Buret Mechanisms of epithelial dysfunction in giardiasis Gut, March 1, 2007; 56(3): 316 - 317. [Full Text] [PDF] |
||||
![]() |
K. Roxstrom-Lindquist, E. Ringqvist, D. Palm, and S. Svard Giardia lamblia-Induced Changes in Gene Expression in Differentiated Caco-2 Human Intestinal Epithelial Cells Infect. Immun., December 1, 2005; 73(12): 8204 - 8208. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Zamora, A. Grishin, C. Wong, P. Boyle, J. Wang, D. Hackam, J. S. Upperman, K. J. Tracey, and H. R. Ford High-mobility group box 1 protein is an inflammatory mediator in necrotizing enterocolitis: protective effect of the macrophage deactivator semapimod Am J Physiol Gastrointest Liver Physiol, October 1, 2005; 289(4): G643 - G652. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Rangasamy, J. Guo, W. A. Mitzner, J. Roman, A. Singh, A. D. Fryer, M. Yamamoto, T. W. Kensler, R. M. Tuder, S. N. Georas, et al. Disruption of Nrf2 enhances susceptibility to severe airway inflammation and asthma in mice J. Exp. Med., July 5, 2005; 202(1): 47 - 59. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |