In the last three decades, the therapeutic utility of blocking lipid mediator generation in humans has become evident in a wide range of inflammatory disorders including asthma and arthritis. Animal studies have shown that certain diets, which alter the amount or types of fatty acid consumed, can reduce arachidonic acid (AA) metabolism and ameliorate several events associated with inflammation. However, dietary studies in humans have been less effective in both regards. After re-examining many of the previously-described dietary studies in humans utilizing well-defined diets (prepared and fed in a GCRC) and precise measurement techniques (GC/MS), we have found that in vivo supplementation of low to moderate fat diets with gammalinolenic acid (GLA) results in a marked decrease in the dihomogammalinolenic acid to AA ratio in neutrophil glycerolipids and a sharp reduction in the capacity of neutrophils to synthesize leukotrienes. These exciting findings support the central hypothesis of this proposal that specific dietary strategies (e.g., strategies which accumulate close structural analogs of AA in cellular glycerolipids) induce significant reductions in AA metabolism in human inflammatory cells resulting in anti- inflammatory effects.
Specific aims :
The aims of this proposal are designed to answer several key question within our central hypothesis: 1. What is the mechanism(s) leading to changes in fatty acids and AA metabolism after GLA supplementation?; 2. Do other (than the neutrophil) key inflammatory cells undergo similar changes in AA metabolism in response to dietary fatty acids?; 3. Can already-developed or newly- proposed strategies be used on a long term basis?; 4. Can these dietary strategies be utilized to treat inflammatory disorders such as asthma? Research design and methods: Negative ion chemical ionization GC/MS will provide very sensitive and selective assays for the measurements of polyunsaturated fatty acid and AA metabolites as well as a means to monitor the in vivo metabolism of fatty acids. The GCRC will provide precisely defined research meals to subjects in all dietary studies. Health relateness: Answering these fundamental questions will shed critical light on the feasibility of utilizing dietary fatty acids to regulate AA metabolism and related clinical disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI042022-01A1
Application #
2690549
Study Section
Nutrition Study Section (NTN)
Project Start
1998-07-10
Project End
2003-05-31
Budget Start
1998-07-10
Budget End
1999-05-31
Support Year
1
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Wake Forest University Health Sciences
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
041418799
City
Winston-Salem
State
NC
Country
United States
Zip Code
27106
Monjazeb, Arta M; High, Kevin P; Connoy, Abbie et al. (2006) Arachidonic acid-induced gene expression in colon cancer cells. Carcinogenesis 27:1950-60
Monjazeb, Arta M; High, Kevin P; Koumenis, Constantinos et al. (2005) Inhibitors of arachidonic acid metabolism act synergistically to signal apoptosis in neoplastic cells. Prostaglandins Leukot Essent Fatty Acids 73:463-74
High, K P; Sinclair, J; Easter, L H et al. (2003) Advanced age, but not anergy, is associated with altered serum polyunsaturated fatty acid levels. J Nutr Health Aging 7:378-84
Clay, Carl E; Monjazeb, Arta; Thorburn, Jacqueline et al. (2002) 15-Deoxy-delta12,14-prostaglandin J2-induced apoptosis does not require PPARgamma in breast cancer cells. J Lipid Res 43:1818-28
Monjazeb, A M; Clay, C E; High, K P et al. (2002) Antineoplastic properties of arachidonic acid and its metabolites. Prostaglandins Leukot Essent Fatty Acids 66:5-12
Fonteh, A N; Marion, C R; Barham, B J et al. (2001) Enhancement of mast cell survival: a novel function of some secretory phospholipase A(2) isotypes. J Immunol 167:4161-71
High, K P (2001) Nutritional strategies to boost immunity and prevent infection in elderly individuals. Clin Infect Dis 33:1892-900
Clay, C E; Atsumi, G I; High, K P et al. (2001) Early de novo gene expression is required for 15-deoxy-Delta 12,14-prostaglandin J2-induced apoptosis in breast cancer cells. J Biol Chem 276:47131-5
Clay, C E; Namen, A M; Atsumi, G et al. (2001) Magnitude of peroxisome proliferator-activated receptor-gamma activation is associated with important and seemingly opposite biological responses in breast cancer cells. J Investig Med 49:413-20
Barham, J B; Edens, M B; Fonteh, A N et al. (2000) Addition of eicosapentaenoic acid to gamma-linolenic acid-supplemented diets prevents serum arachidonic acid accumulation in humans. J Nutr 130:1925-31

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