2006 Annual Report
1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
This project is aligned with the National Program 107 N Human Nutrition. The amount and type of dietary fatty acids play an important role in health maintenance and disease prevention. Different fatty acids and their metabolites regulate signal transduction, gene expression, cell growth, differentiation, and death. Excessive intake of omega-6 fatty acids found in most seed oils has the potential to increase inflammatory diseases, while omega-3 fatty acids found in marine and some seed oils (flax, perilla, and walnuts) have strong anti-inflammatory effects; ratio between the dietary omega-6 and omega-3 fatty acids influences the development and progression of several human chronic diseases including cardiovascular disease (CVD), diabetes, arthritis, lupus, inflammatory bowel disease, and many others. CVD alone is responsible for more than one-half of all the deaths in USA and many European countries. Overall goal of our studies is to determine the effects of dietary fatty acids on immune and inflammatory responses and on risk factors of chronic diseases. Specific objectives are: 1. Determine effects of DHA supplementation on risk factors for CVD in hypertriglyceridemic men. 2. Determine effects of omega-6 and omega-3 fatty acids on proliferation and differentiation of granulocytic precursor cells, and elucidate the mechanisms involved. 3. Determine whether different dietary fatty acids modulate the activation of Toll-like receptors, downstream signaling pathways, target gene expression and consequent cellular responses. Specific aim 1 will involve DHA supplementation of hypertriglyceridemic men, and monitoring its effects on a number of conventional and novel markers for CVD, markers for diabetes, and gene expression. Specific aims 2 & 3 will involve feeding diets with different fatty acid compositions to animal models, and adding fatty acids to cultured cells. Results obtained will provide the information needed to determine dietary requirements for long chain PUFA, specific dietary fatty acid based therapies for the prevention and management of inflammatory conditions. This is expected to improve quality of life and may open new avenues for agricultural products. Understanding the mechanisms by which different dietary fatty acids improve health or cause diseases, may identify the metabolic sites that may be regulated by drug therapies as well.
2.List by year the currently approved milestones (indicators of research progress)
Subject recruitment, fatty acid supplementation, and sample collection.
Continue with that listed for year 1 and start sample and data analysis.
Conduct experiments with promyelocytic cell lines.
Determine relative potency of n-3 PUFAs as compared with n-6 PUFAs in inhibiting the activation of toll like receptors (TLR) and if different TLRs are differently modulated by fatty acids.
Sample and data analysis, and preparation of manuscripts.
Analyze data from experiments with cell lines and prepare manuscripts, conduct experiments with mice.
Analyze samples and data from the mice study, and prepare manuscripts.
Whether TLR4 induced activation of downstream signaling pathways and target gene expressions are also altered by fatty acids.
4a.List the single most significant research accomplishment during FY 2006.
DHA supplementation reduced the risk for cardiovascular disease (CVD) in hypertriglyceridemic men. Hypertriglyceridemia increases number of small dense low density lipoprotein particles and inflammation which are important independent risk factors for CVD. In a study conducted in the laboratory of Dr Darshan S. Kelley at the WHNRC Davis, CA, in collaboration with Dr David Siegel of the Mather VA Medical Center, 34 hypertriglyceridemic men (45-65 y) were randomly divided into 2 equal groups receiving the supplement (7.5 g DHA oil providing DHA 3 g/d) or placebo (7.5 g olive oil) for 90 days. Fasting and postprandial blood samples were collected before, middle and end of the supplementation phase and analyzed for the concentration of various risk factors CVD. Results showed that DHA supplementation significantly reduced circulating triglycerides, number of atherogenic small dense LDL particles and the inflammatory marker C reactive protein. Thus, overall DHA reduced the risk for CVD. This accomplishment addresses Component 4, Nutrients Requirements; Component 5, Health Promoting Properties of Plant and Animal Foods, and Component 7, Health Promoting Intervention Strategies for Targeted Populations of National Program 107, Human Nutrition.
4b.List other significant research accomplishment(s), if any.
Supplementing Mouse diet with t10, c12-CLA drastically altered tissue fatty acid composition. This study was conducted in the laboratory of Dr Darshan S. Kelley at the WHNRC Davis, CA. Eight wk old female mice were fed either a control diet or a diet in which 0.5% corn oil was replaced with an equivalent amount of the CLA for 8 wks. In addition to the development of a fatty liver, CLA supplementation caused dramatic changes in the fatty acid composition of other tissues. It reduced the heart DHA concentration by 25% and increased it by 700% in spleen; it also caused a 95% reduction in spleen arachidonic acid concentration. These changes in fatty acid metabolism caused by CLA may have serious health consequences. This accomplishment addresses Component 5, Health Promoting Properties of Plant and Animal Foods and Component 6, Prevention of Obesity and Disease Relationship between Diet, Genetics and Lifestyle of National Program 107, Human Nutrition.
Bing sweet cherries reduced the plasma concentration of inflammatory markers in healthy men and women. This study was conducted in the laboratory of Dr Darshan S. Kelley at WHNRC Davis, CA, in collaboration with Dr Adel Kader of UCD. Eighteen healthy men and women consumed Bing Sweet cherries (280 g/d for 28 d). Fasting blood samples were collected before and after the consumption of cherries and plasma concentrations of inflammatory makers determined. Cherry consumption reduced the plasma concentration of CRP, NO, and RANTES by 18-25%. These are important markers for inflammatory disease including CVD and arthritis. Results suggest cherry consumption may reduce the risk for inflammatory diseases. This accomplishment addresses Component 5, Health Promoting Properties of Plant and Animal Foods of National Program 107, Human Nutrition.
Differential Modulation of Toll-like Receptor-Mediated Inflammatory Responses by Fatty Acids. Dietary saturated fatty acids enhanced but n-3 polyunsaturated fatty acids (PUFAs) inhibited inflammatory responses induced by the activation of Toll-like receptors in animal studies. To determine functional consequence of these effects, Daniel Hwang's group (Western Human Nutrition Research Center, Davis, CA) investigated whether saturated fatty acids and n-3 PUFAs similarly modulate immune responses. The results showed that saturated fatty acids activate but n-3 PUFAs inhibit dendritic cell activation and antigen specific T-lymphocyte activation. These results suggest that immune responses can be differentially modulated by types of dietary fatty acids. This accomplishment addresses Component 4, Nutrient Requirements and Component 5, Health Promoting Properties of Plant and Animal Foods of National Program 107, Human Nutrition.
Inhibition of Toll-like Receptor-Mediated Inflammatory Responses by Plant Polyphenols. Many plant Polyphenols (resveratrol, curcumin, epigallocatechin) are known to possess anti-inflammatory effects. Daniel Hwang's group (Western Human Nutrition Research center, Davis, CA) investigated whether certain plant polyphenols inhibit Toll-like receptor-induced inflammation in in vitro studies using macrophage and B-lymphocyte cell lines. The results suggest that the anti-inflammatory effects of plant polyphenols are mediated at least in part by inhibiting Toll-like receptor -mediated signaling pathways that are important to induce sterile inflammation associated with increased risk of development of chronic diseases. Since enhanced inflammation is considered as one of important etiological conditions in development of many chronic diseases, these results suggest that certain plant polyphenols may have preventive potency against development of chronic inflammatory disease. This accomplishment addresses Component 5, Health Promoting Properties of Plant and Animal Foods of National Program 107, Human Nutrition.
4c.List significant activities that support special target populations.
Results from the DHA and cherry studies discussed above can be quite helpful for the obese and dyslipidemic subjects.
We have not been able to start the human study with citrus liminoids because of the unexpected problems with the purification of the liminoids. Purification of this product is handled by our collaborators at WRRC. We understand the problems have been identified and progress is being made with purification. We hope enough material will be available to start with 4 subjects in August 2007.
Our USDA-NRI grant(2001-35200-10721) was completed and terminated in December, 2004.
The main goal of the grant was to investigate the mechanism by which dietary n-3 fatty acids suppress tumor cell growth. The major finding of the results from the studies was that dietary n-3 fatty acids suppress PPAR delta which is implicated to promote cell proliferation, and thereby inhibit cell proliferation.
5.Describe the major accomplishments to date and their predicted or actual impact.
This is a new CRIS and the report is for its third year; hence there are no major accomplishments to report other than those listed under question 4. Our previous CRIS also dealt with the health effects of dietary fatty acids and the accomplishments listed are for the expired CRIS. Research conducted under the expired CRIS showed that increasing total fat intake inhibited several aspects of human immune status. If total fat intake was held constant, increasing the intake of omega-3 fatty acids reduced a number of markers for inflammation (numbers of circulating granulocytes, inflammatory cytokines and eicosanoids), while omega-6 fatty acids had the opposite effects. Omega-3 fatty acids are now used in the management of several inflammatory diseases including, CVD, arthritis, asthma, and adult respiratory distress syndrome or ARDS. We have also shown that the ratio between saturated and unsaturated fatty acids was more critical than the amount of dietary fat in determining serum cholesterol levels. Our studies conducted with CLA supplementation showed no benefit, but several potential risks to humans. Results from our studies have been used by health organizations for making recommendations regarding fatty acid intake.
This accomplishment addresses Component 4, Nutrient Requirements; Component 5, Health Promoting Properties of Plant and Animal Foods, and Component 7, Health Promoting Intervention Strategies for Targeted Populations of National Program 107, Human Nutrition.
6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
Anti-inflammatory effects of cherries, a broadcast by VOA, June 8, 2006
RSSL-PHARMA, Food e-news regarding the results from our Cherry study on May 17, 2006
ARS news "cherries pack an anti-inflammatory punch," May 11, 2006.
Healing Foods-cherries AARP, March/April 2006
There have been interviews with some other magazines/ news letters that will be published in near future.
Invited as a speaker for the symposium on Dietary Lipids and Cell Membrabne
Structure/Function in Immunity and Inflammation. EB meeting, San Francisco, April 3, 2006
Invited as a speaker at the World Nutra 2005, Anaheim, CA. October 16, 2005
(Dietary modulation of inflammation and beyond)
Kelley, D.S., Rasooly, R., Jacob, R.A., Kader, A.A., Mackey, B.E. 2006. CONSUMPTION OF BING SWEET CHERRIES LOWERS CIRCULATING CONCENTRATIONS OF INFLAMMATION MARKERS IN HEALTHY MEN AND WOMEN. Journal of Nutrition. 136:981-986, 2006.
Kelley, D.S., Bartolini, G.L., Newman, J.W., Vemuri, M., Mackey, B.E. 2006. FATTY ACID PROFILES OF LIVER, ADIPOSE TISSUE, SPLEEN, AND HEART OF MICE FED DIETS CONTAINING T10, C-12-, AND C9, T11-CONJUGATED LINOLEIC ADIC. Prostaglandins Leukotrienes and Essential Fatty Acids. 74:331-338.
Youn, H.S., Lee, J.Y., Fitzgerald, K.A., Young, H., Akira, S., Hwang, D.H. 2005. SPECIFIC INHIBITION OF MYD88-INDEPENDENT SIGNALING PATHWAYS OF TOLL-LIKE RECEPTOR 3 AND 4 BY RESVERATROL: MOLECULAR TARGETS ARE TBK1 IN TRIF COMPLEX. Journal of Immunology. 175:3339-3346, 2005.
Lee, J.Y., Lowell, C.A., Lemay, D.G., Youn, H.S., Rhee, S.H., Sohn, K.H., Jang, B., Ye, J., Chung, J.H., Hwang, D.H. 2005. THE REGULATION OF THE EXPRESSION OF INDUCIBLE NITRIC OXIDE SYNTHASE BY SRC-FAMILY TYROSINE KINASE MEDIATED THROUGH MYD88-INDEPENDENT SIGNALING PAYWAYS OF TOLL-LIKE RECEPTOR 4. Biochemical Pharmacology, 70:1231-1240.
Youn, H.S., Saitoh, S.I., Miyake, K., Hwang, D.H. 2006. INHIBITION OF HOMODIMERIZATION OF TOLL-LIKE RECEPTOR 4 BY CURCUMIN. Biochemical Pharmacology. 72(2006):62-69.
Lemay, D.G., Hwang, D.H. Genome-wide identification of peroxisome proliferator response elements using integrated computational genomics. Journal of Lipid Research. 47:1583-1587, 2006.