|
|
||||||||
Department of Medicine, Division of Newborn Medicine, Childrens Hospital and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115
Abstract
An increasing number of studies implicate heme oxygenase-1 (HO-1) in the regulation of inflammation. Although the mechanisms involved in this cytoprotection are largely unknown, HO-1 and its enzymatic products, carbon monoxide and bilirubin, downregulate the inflammatory response by either attenuating the expression of adhesion molecules and thus inhibiting leukocyte recruitment or by repressing the induction of cytokines and chemokines. In the present study we used genetically engineered mice that express high levels of a human cDNA HO-1 transgene in lung epithelium to assess the effect of HO-1 on lung inflammation. Two separate models of inflammation were studied: hypoxic exposure and lipopolysaccharide (LPS) challenge. We found that both mRNA and protein levels of specific cytokines and chemokines were significantly elevated in response to hypoxia in the lungs of wild-type mice after 2 and 5 days of exposure but significantly suppressed in the hypoxic lungs of transgenic mice, suggesting that inhibition of these cytokines was caused by overexpression of HO-1. However, LPS treatment resulted in a very pronounced increase in mRNA levels of several cytokines in both wild-type and transgenic mice. Despite the high mRNA levels, significantly lower cytokine protein levels were detected in the bronchoalveolar lavage of HO-1 overexpressing mice compared with wild type, indicating that HO-1 leads to repression of cytokines in the airway. These results demonstrate that HO-1 activity operates through distinct molecular mechanisms to confer cytoprotection in the hypoxic and the LPS models of inflammation.
Key Words: sepsis shock hypoxia adhesion molecule
This article has been cited by other articles:
![]() |
C.-F. Chen and C.-H. Cheng Regulation of Cellular Metabolism and Cytokines by the Medicinal Herb Feverfew in the Human Monocytic THP-1 Cells Evid. Based Complement. Altern. Med., March 1, 2009; 6(1): 91 - 98. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Patil, L. Bellner, G. Cullaro, K. H. Gotlinger, M. W. Dunn, and M. L. Schwartzman Heme Oxygenase-1 Induction Attenuates Corneal Inflammation and Accelerates Wound Healing after Epithelial Injury Invest. Ophthalmol. Vis. Sci., August 1, 2008; 49(8): 3379 - 3386. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z.-W. Xia, C.-E Li, Y.-X. Jin, Y. Shi, L.-Q. Xu, W.-W. Zhong, Y.-Z. Li, S.-C. Yu, and Z.-L. Zhang Reduction of Bilirubin by Targeting Human Heme Oxygenase-1 Through siRNA Experimental Biology and Medicine, April 1, 2007; 232(4): 495 - 502. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. E. Fredenburgh, M. A. Perrella, and S. A. Mitsialis The Role of Heme Oxygenase-1 in Pulmonary Disease Am. J. Respir. Cell Mol. Biol., February 1, 2007; 36(2): 158 - 165. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. R. Stenmark, K. A. Fagan, and M. G. Frid Hypoxia-Induced Pulmonary Vascular Remodeling: Cellular and Molecular Mechanisms Circ. Res., September 29, 2006; 99(7): 675 - 691. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Zager, A. C. M. Johnson, S. Lund, and S. Hanson Acute renal failure: determinants and characteristics of the injury-induced hyperinflammatory response Am J Physiol Renal Physiol, September 1, 2006; 291(3): F546 - F556. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. P. Carter, C. Garat, and M. Imamura Continual emerging roles of HO-1: protection against airway inflammation Am J Physiol Lung Cell Mol Physiol, July 1, 2004; 287(1): L24 - L25. [Full Text] [PDF] |
||||
![]() |
H. Chiu, C. R. Gardner, D. M. Dambach, J. A. Brittingham, S. K. Durham, J. D. Laskin, and D. L. Laskin Role of p55 tumor necrosis factor receptor 1 in acetaminophen-induced antioxidant defense Am J Physiol Gastrointest Liver Physiol, November 1, 2003; 285(5): G959 - G966. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |