| |
|
|
|
|
|
|
|||
|
Blood, 1 January 2009, Vol. 113, No. 1, pp. 224-232. Prepublished online as a Blood First Edition Paper on September 23, 2008; DOI 10.1182/blood-2008-06-165746.
VASCULAR BIOLOGY Central role of Sp1-regulated CD39 in hypoxia/ischemia protection1 Department of Anesthesiology and Perioperative Medicine, University of Colorado Health Sciences Center, Denver; 2 Department of Anesthesiology and Intensive Care Medicine, University Hospital, Tübingen, Germany; 3 Mucosal Inflammation Program, Department of Medicine, University of Colorado Health Sciences Center, Denver; 4 Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; and 5 Gastroenterology Division, Department of Medicine, Beth Israel Deaconess Hospital and Harvard Medical School, Boston, MA Hypoxia is common to several inflammatory diseases, where multiple cell types release adenine-nucleotides (particularly adenosine triphosphate/adenosine diphosphate). Adenosine triphosphate/adenosine diphosphate is metabolized to adenosine through a 2-step enzymatic reaction initiated by CD39 (ectonucleoside-triphosphate-diphosphohydrolase-1). Thus, extracellular adenosine becomes available to regulate multiple inflammatory endpoints. Here, we hypothesized that hypoxia transcriptionally up-regulates CD39 expression. Initial studies revealed hypoxia-dependent increases in CD39 mRNA and immunoreactivity on endothelia. Examination of the human CD39 gene promoter identified a region important in hypoxia inducibility. Multiple levels of analysis, including site-directed mutagenesis, chromatin immunoprecipitation, and inhibition by antisense, revealed a critical role for transcription-factor Sp1 in hypoxia-induction of CD39. Using a combination of cd39–/– mice and Sp1 small interfering RNA in in vivo cardiac ischemia models revealed Sp1-mediated induction of cardiac CD39 during myocardial ischemia. In summary, these results identify a novel Sp1-dependent regulatory pathway for CD39 and indicate the likelihood that CD39 is central to protective responses to hypoxia/ischemia.
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Copyright © 2009 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||