Patients with sepsis are highly susceptible to the development of nosocomial infection, particularly bacterial infection of the lung. While the exact mechanism(s) that contribute to sepsis-mediated immunosuppression remains unclear, dysregulation of monocyte/macrophage function is believed to play an important role in these phenomena. Recently, peroxisome proliferator-activated receptor-gamma (PPARy), a member of the nuclear receptor superfamily of ligand-dependent transcription factors, has been shown to inhibit the expression of inflammatory mediators from monocytes/macrophages and other leukocyte populations. The hypothesis of this proposal is that sepsis induced immunosuppression is mediated, in part, by PPARy. Furthermore, we postulate that inhibition of this ligand dependent transcription factor will reverse sepsis-induced changes in alveolar macrophage function, resulting in augmented lung antibacterial host defense. A murine model of cecal ligation and puncture (resulting in an abdominal sepsis syndrome) will be utilized to assess the following Specific Aims: I) to determine the time course and magnitude of PPARy expression in lung during the evolution of murine abdominal sepsis; II) to determine the functional significance of PPARy activation on effector cell functions of primary murine alveolar macrophages or murine alveolar macrophage cell lines; III) to identify the endogenous signals that regulate PPARy expression during the evolution of murine abdominal sepsis; and IV) to determine the effect of inhibition of PPARy on sepsis- induced alterations in alveolar macrophage function ex-vivo and susceptibility to Pseudomonas pneumonia in-vivo. Performance of the studies outlined will help define the role of PPARy as a mediator of sepsis-induced alveolar macrophage dysfunction, and may lead to the development of novel therapies to be employed in the treatment of patients with sepsis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08HL070068-04
Application #
6944326
Study Section
Special Emphasis Panel (ZHL1-CSR-M (F2))
Program Officer
Colombini-Hatch, Sandra
Project Start
2002-09-30
Project End
2007-08-31
Budget Start
2005-09-01
Budget End
2006-08-31
Support Year
4
Fiscal Year
2005
Total Cost
$132,658
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Khan, Farah I; Reddy, Raju C; Baptist, Alan P (2009) Pediatric Dyspnea Scale for use in hospitalized patients with asthma. J Allergy Clin Immunol 123:660-4
Narala, Venkata R; Smith, Monica R; Adapala, Ravi K et al. (2009) Curcumin is not a ligand for peroxisome proliferator-activated receptor-? Gene Ther Mol Biol 13:20-25
Reddy, Praveen K; Reddy, Srinivasa G; Narala, Venkata R et al. (2007) Increased yield of high purity recombinant human interferon-gamma utilizing reversed phase column chromatography. Protein Expr Purif 52:123-30
Keshamouni, Venkateshwar G; Reddy, Raju C; Arenberg, Douglas A et al. (2004) Peroxisome proliferator-activated receptor-gamma activation inhibits tumor progression in non-small-cell lung cancer. Oncogene 23:100-8
Reddy, Raju C; Keshamouni, Venkateshwar G; Jaigirdar, Shamsul H et al. (2004) Deactivation of murine alveolar macrophages by peroxisome proliferator-activated receptor-gamma ligands. Am J Physiol Lung Cell Mol Physiol 286:L613-9