Published ahead of print on June 18, 2009, doi:10.1165/rcmb.2008-0265OC A more recent version of this article appeared on June 25, 2009
Submitted on July 16, 2008 Receptors for Advanced Glycation End-products (RAGE) Targeting Protects Against Hyperoxia-Induced Lung Injury in MicePaul R Reynolds1*,1 Internal Medicine, Pulmonary Division, University of Utah Health Sciences Center, Salt Lake City, Utah, United States; Physiology and Developmental Biology, Brigham Young University, Provo, Utah, United States, 2 Internal Medicine, Pulmonary Division, University of Utah Health Sciences Center, Salt Lake City, Utah, United States, 3 Medicine and Clinical Chemistry, University Clinics, Heidelberg, Germany * To whom correspondence should be addressed. E-mail: paul.reynolds{at}hsc.utah.edu.
Patients with acute lung injury (ALI) almost always require supplemental oxygen during treatment; however, elevated oxygen itself is toxic. Receptors for advanced glycation end-products (RAGE) are multiligand cell surface receptors predominantly localized to alveolar type I (ATI) cells that influence development and cigarette smoke-induced inflammation, but studies that address the role of RAGE in ALI are insufficient. In the present investigation, we test the hypothesis that RAGE signaling functions in hyperoxia-induced inflammation. RAGE null mice exposed to hyperoxia survived 3 days longer than age-matched wild-type mice. After four days in hyperoxia, RAGE null mice had less total cell infiltration into the airway, decreased total protein leak, diminished alveolar damage in H&E stained lung sections, and a lower lung wet-to-dry weight ratio. An inflammatory cytokine antibody array revealed decreased secretion of several pro-inflammatory molecules in lavage fluid obtained from RAGE knock out mice when compared to wild-type controls. Real time RT-PCR and immunoblotting revealed that hyperoxia induced RAGE expression in primary alveolar epithelial cells and immunohistochemistry identified increased RAGE expression in the lungs of mice following exposure to hyperoxia. These data reveal that RAGE targeting leads to a diminished hyperoxia-induced pulmonary inflammatory response. Further research into the role of RAGE signaling in the lung should identify novel targets likely to be important in the therapeutic alleviation of lung injury and associated persistent inflammation. Key words: ALI Inflammation RAGE Hyperoxia
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