Annual/Termination Reports:

[07/21/2010] [06/17/2011] [05/29/2012] [07/01/2013] [10/14/2014] [07/30/2014]

Report Information

Participants

Brief Summary of Minutes

Accomplishments

Accomplishments<br /> Washington State University (Dodson), Objectives 1,2,3,4,5,6,7,8,9,10. Cell physiology of mature adipocytes during a return to a state of proliferation-competency and evaluation of daughter progeny cells. Pig-derived mature adipocytes were isolated, purified and proliferative-competent progeny cells were allowed to undergo population expansion to insure cycling of all cells through the cell cycle. Progeny cells were then plated at equal numbers, in triplicate, and provided reduced levels of serum-containing media, without any differentiation-induction treatment (no DMI) and monitored for conversion to lipid-assimilating adipocytes. Cultures were terminated, RNA was preserved and is in the process of being evaluated for microRNA. Significance. Less than 30 microRNA species have been identified (to date) for the pig. This research will add to this number and help determine if microRNA plays any role in conversion of proliferative-competent cells into lipid-assimilating cells, in vitro. Results. In progress. Funding. This work is being completed in conjunction with researchers in Canada (Dr.'s LeLuo Guan, Weiwu Jin, Priya Mir, and Steve Moore), China (Dr. Jie Chen), the USA (Dr.'s Hausman, Poulos and Fernyhough) and at WSU (Dr. Zhihua Jiang). Collaborative Efforts:1. I am trying to make an effort to involve as many members of this group into the collective writing of data papers, review papers, opinion papers, and grants. In order to survive (in the future) these types of efforts will be demanded. I am willing to "spear-head" such efforts. 2. I am trying to become efficient at nominating individuals (of this group) for a variety of awards. Why? Many individuals of this group have already received numerous awards. This group will need such continued efforts in the future to demonstrate National/International prominence.<br /> University of California, Davis. (Sainz) Objectives. 1,2,3,4. Our group has continued work on two fronts: mathematical modeling of adipocyte hyperplasia and hypertrophy in beef cattle, and experimental analyses of the factors affecting these processes. The modeling work has benefited from collaboration with a group in Australia with access to a large dataset comprising several genetic groups and nutritional management strategies. Work is ongoing to fit our models to a subset of those data, and to use the remainder to challenge the models. Experimentally, we have been working on optimal protocols for sampling and analysis of bovine muscle for determination of adipocyte cellularity. Sampling bias is the major source of variation when estimating adipocyte size and number. A sampling technique should be developed to reduce sampling bias and increase the precision when estimating adipocyte cellularity. Currently our laboratory is developing such technique.<br /> Ohio State University (Lee), objectives 1,2,3,4,5,6,7,8,9,10. Enhancing growth rates with larger muscle mass, reduction of subcutaneous fat, and enhanced intramuscular fat will be beneficial to livestock producers and the consumer. We have focused on discovery of novel factors and understanding their roles in adipose tissue and muscle development. We have employed DNA microarray to discover new candidate genes for fat accretion in food-animals and human obesity. To further evaluate whether these genes are strong candidates for the obesity condition, we recently developed a series of experimental methods for a rapid high throughput screening. Using our unique approach, we have selected several candidate genes as a high priority group to intensively study the role of these candidate genes in adipocyte development and obesity. Adipose triglyceride lipase (ATGL), a newly discovered lipase, hydrolyzes the first ester bond of stored triglycerides which releases nonesterified-free fatty acids. However, the role of ATGL in fat accretion and development has not been studied in the avian species. Recently, we have cloned and sequenced the ATGL cDNAs for chickens, turkeys and quails. In 2009, we completed the study on the expression of the ATGL gene in adipose tissue during the developmental process, in response to hormonal stimuli and nutritional status. We are also working on the effect of overexpression of ATGL in adipose tissue on adipose development and lipid metabolism in transgenic birds. Currently, our collaborative team put a great effort on the grant proposal to integrate microarray, proteomic, bioinformatic and functional genomic analyses into an adipomic approach to understand the fundamentals of adipose tissue biology. <br /> Iowa State University (Beitz), objectives 1,2,3,5,6,9. High concentrations of saturated fatty acids (SFA) in human diets are known to increase plasma cholesterol concentrations and as a result, increase the risk of developing cardiovascular diseases, the number one cause of death worldwide. Separate SFA, however, do not have the same effect on plasma cholesterol concentrations. Palmitic (16:0) and myristic (14:0) acids, for example, can raise plasma cholesterol concentrations much higher than other SFA. Bovine milk is one of the primary sources of SFA in human diets and the concentration of palmitic (16:0) acid in milk is the highest compared with the other fatty acids. So, the main objective of our project was to develop genetic markers allowing for the selection of animals that can produce milk with healthier fatty acid profile. The candidate gene approach was used to address the objective. Genes involved in milk triacylglycerol (TAG) biosynthesis, fatty acid uptake into mammary gland and fatty acid transport inside the mammary epithelial cells, and transcriptional regulation of some lipogenic genes were selected for the study. DNA sequencing was used to discover single nucleotide polymorphisms (SNPs) in the genes of interest and after genotyping 550 cows for the discovered SNPs, haplotype reconstruction was performed to test the association of genetic polymorphisms with milk fatty acid composition. The phenotypic data were comprised of milk samples collected for each cow once a month throughout a 305 d lactation period with subsequent analysis of all the milk samples for fatty acid composition by using gas chromatography. The glycerol-3-phosphate acyltransferases-1 and -4 (GPAT1 and GPAT4), 1-acylglycerol-3-phosphate acyltransferase-1 (AGPAT1), and phosphatidate phosphatase (LPIN1) genes from the TAG biosynthetic pathway were studied to test the association of the polymorphisms in those genes with milk fatty acid composition. The polymorphisms in GPAT4 gene were significantly associated with the concentrations of capric (10:0), lauric (12:0), palmitic (16:0), oleic (18:1c9), and linoleic (18:2c9, c12) acids and as a consequence with the concentrations of SFA, unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), SFA/UFA ratio, C16 and C18 desaturation indices and atherogenic index (AI). As compared with the effects of diacylglycerol acyltransferase-1 (DGAT1) A232K mutation on milk fatty acid composition, the size of the effects of GPAT4 polymorphisms was bigger for AI, concentrations of SFA, UFA, MUFA, SFA/UFA ratio, concentrations of capric (10:0), lauric (12:0), linoleic (18:2c9, c12) acids, CLA (18:2c9, t11), and C18 desaturation index. The effects of GPAT1 polymorphisms were associated with the concentrations of caproic (6:0), caprylic (8:0), capric (10:0), tridecylic (13:0), margaric (17:0), myristoleic (14:1c9), palmitoleic (16:1c9) acids, C14 and C16 desaturation indices. The size of the effects of GPAT1 polymorphisms on the concentrations of caproic (6:0), caprylic (8:0), tridecylic (13:0), margaric (17:0) acids, and C14 and C16 desaturation indices was bigger compared with the size of the effects of DGAT1 A232K mutation. The polymorphisms in AGPAT1 gene were associated with PUFA, caproic (6:0), margaric (17:0), myristoleic (14:1c9) acids, and CLA (18:2c9, t11) concentrations. The polymorphisms in LPIN1 gene were associated with only myristoleic (14:1c9) acid concentration and C14 desaturation index.The isoform A6 of solute carrier family 27 (SLC27A6) and fatty acid binding proteins 3 and 4 (FABP3 and FABP4) genes involved in fatty acid uptake into mammary gland and fatty acid transport inside the mammary epithelial cells were studied to test the association of the polymorphisms in those genes with milk fatty acid composition. The concentrations of capric (10:0), lauric (12:0), myristic (14:0), and palmitic (16:0) acids in milk were significantly associated with the polymorphisms in SLC27A6 gene. The AI, concentrations of SFA, UFA, MUFA, and SFA/UFA ratio were affected by SLC27A6 genetic polymorphisms as well as a consequence of the association with medium-chain fatty acids and palmitic (16:0) acid. The size of the effects of the SLC27A6 genetic polymorphisms on the concentrations of MUFA, capric (10:0) and lauric (12:0) acids were bigger compared with the size of the effects caused by DGAT1 A232K mutation. The effects of SLC27A6 genetic polymorphisms on other traits such as AI, the concentrations of SFA, UFA, palmitoleic (16:1c9) acid, and the SFA/UFA ratio were very close in size to those observed for DGAT1 A232K mutation. The concentration of myristic (14:0) acid was affected by SLC27A6 polymorphisms to a greater extend compared with the effects of fatty acid synthase g. 17924 A>G mutation. The polymorphisms in FABP3 gene were associated with pentadecylic (15:0) and oleic (18:1c9) acid concentrations and the elongation index. The FABP4 genetic polymorphisms were associated with SFA, UFA, MUFA, PUFA, linoleic (18:2c9, c12) acid concentrations and SFA/UFA ratio.The sterol regulatory element binding protein-1c (SREBP-1c) is involved in the transcriptional regulation of lipogenesis and its proteolytic activation is controlled by SREBP cleavage-activating protein (SCAP) and insulin-induced genes (Insig) that are all part of so called the SREBP pathway. The effects of SREBP genetic polymorphisms were associated with the concentrations of myristic (14:0), myristoleic (14:1c9) acids, and C14 desaturation index. The effects of Insig-1 genetic polymorphisms were associated with the concentrations of MUFA, PUFA, yristoleic (14:1c9), palmitic (16:0), linoleic (18:2c9, c12) acids, and C16 desaturation index. There were no associations of SCAP genetic polymorphisms with milk fatty acid composition.In conclusion, we were able to identify genetic polymorphisms in GPAT4, GPAT1, and SLC27A6 genes that were associated with the differences in milk fatty acid composition and the size of those differences for certain fatty acids was the largest ever know even when compared with the effects of DGAT1 A232K mutation. The associations of the polymorphisms for the other genes were valuable as well. The results of this study provide the information about genetic polymorphisms that can be used to develop genetic markers for the selection of animals that will produce milk with the healthier fatty acid profile.<br /> <br /> North Carolina State University (Odle), objectives 1,2,3,8. Production of value-added pork by enrichment with omega-3 fatty acids.This study evaluated the impact of dietary docosahexaenoic acid (DHA) and linolenic acid (LN) on enrichment of n-3 fatty acids in pork when supplemented for the last 4 or 8 wk of the finisher period. Diets consisted of a corn-soybean meal based control supplemented with 0, 1.5 or 3.0% DHA-GOLD® (Martek Biosciences Corp, Columbia, MD) to supply 0, 0.27, or 0.54% DHA, respectively, or with 1.04% flax seed oil (Jedwards International, Quincy, MA) to supply 0.54% LN. Products were substituted for a saturated fat source (Fat Pack 100, Milk Specialties, Dundee, IL). Pigs (n=40, 67.7±1.1 kg BW) were housed individually and given ad libitum access to feed and water. Pigs were slaughtered at 115.6±5.4 kg BW and a 2.5 cm thick loin chop was collected from each pig. Chops were trimmed into retail cuts and subsequently ground to obtain a homogeneous sample. Fat was extracted and fatty acid concentrations were determined using gas-liquid chromatography. Fat supplements did not affect (P > 0.05) daily weight gain (0.90±0.15 kg), feed intake (2.77±0.65 kg) or gain:feed (0.36±0.06), but increased DHA accumulation linearly with diet concentration and with feeding duration (P < 0.05). Supplemental LN tended to increase (P = 0.08) loin LN at wk 8 only. We conclude that pork loin content of n-3 fatty acids can be markedly enriched in as little as four weeks of supplementation during the late finisher phase. Furthermore, DHA was enriched more efficiently than LN, and LN supplementation did not alter DHA, suggesting low elongation and/or desaturation. Docosahexaenoic acid does not increase insulin sensitivity in gilts.Dietary fish oil increased insulin sensitivity in several species including miniature pigs. Fish oil is rich in eicosapentaenoic acid (EPA, 20:5, n-3) and docosahexaenoic acid (DHA, 22:6, n-3). The objective was to measure insulin sensitivity in gilts consuming diets containing added DHA. Gilts were fed diets formulated to contain 0% DHA (Control, Cont; n=5) or 0.54% added DHA provided by DHAgold (Martek Biosciences Corp., Columbia, MD; n=7). Inclusion of DHAgold also provided 0.23% added docosapentaenoic acid (DPA, 22:5, n-6). Diets were fed for 6 wks before measurement of insulin sensitivity. Body weight at the time of sampling was 110.0 kg (SEM 7.3 kg) for gilts fed Cont and 111.4 kg (SEM = 6.0 kg) for gilts fed DHA. An i.v. glucose tolerance test (IVGTT; 1.25 g glucose/kg BW 0.75) and an i.v. insulin tolerance test (IVITT; 0.30 IU insulin/kg BW 0.75) were conducted on successive days. Blood samples were taken from indwelling jugular catheters at 30, 15, and 5 min before and 2.5, 5, 10, 15, 20, 30, 40, 50, 60, 75, and 90 min after infusion to measure concentrations of Gluc and Ins (IVGTT) or Gluc only (IVITT). Basal concentrations of Gluc and Ins did not differ between diets and were 5.06 and 4.82 mM Gluc; and 12.6 and 9.2 uIU/mL Ins for Cont gilts and DHA gilts, respectively. The area under the response curve (AUC) for Gluc response to the Gluc infusion (mM Gluc x 30 min) tended to be greater (P < 0.07) in gilts fed DHA (113.9) compared to Cont gilts (94.0). There was a tendency (P = 0.10) for greater Gluc half-life (min) in gilts fed DHA (9.96) than gilts fed Cont (8.52). The AUC for Ins response to the Gluc infusion and the AUC for Gluc response to the Ins infusion did not differ for the 2 groups and were 1002 and 1266 (uIU insulin/mL x 30 min) for Cont and DHA gilts, respectively, and 182 and 170 (mM Gluc x 90 min) for Cont and DHA gilts, respectively. Lack of response suggests that fish oil may not increase Ins sensitivity in these pigs, the response observed due to feeding fish oil is due to EPA rather than DHA, or the presence of DPA diminished the response.<br /> <br /> Purdue University (Ajuwon), objectives 1,2,3,4,6,8,10. Our research team has continued our work on the regulation of inflammation in adipose tissue. In 2009, we described the role of TLR2 in the adipocyte. Although adipocytes express multiple toll-like proteins, toll-like receptor 4 (TLR4) has been the most widely studied. However, obesity is accompanied by an increase in the expression of TLR2 as well, indicating that this receptor might be implicated in the metabolic impairments such as insulin resistance of the obese adipose tissue. Using a peptidoglycan model of TLR2 activation, we showed that adipocytes have a functional TLR2 signaling apparatus that when activated leads to the induction of inflammatory cytokines like interleukin 6 (IL-6) at the mRNA and protein levels. Another focus of our work is the role of extracellular matrix (ECM) proteins in adipose tissue expansion. We have determined that there is differential regulation of ECM proteins in adipose tissue; especially there are differences in the subcutaneous and the visceral depot. These differences are true in multiple species (mice, pigs and humans). We have also determined that adipocyte proliferation and apoptosis may be under the regulation of ECM proteins such as decorin and biglycan. In in vitro experiments these proteoglycans lead to induction of apoptosis in 3T3-L1 preadipocytes. Additionally, because inflammation is a major component of obesity, we examined the regulation of inflammation by biglycan. Biglycan led to a significant induction of IL-6 expression both in macrophages and adipocytes. The implication of these findings is that under conditions of adipose tissue expansion and increased expression of ECM proteins. Proteins such as biglycan and decorin may serve to limit adipose tissue expansion by inducing adipocyte apoptosis. Additionally, biglycan may contribute to the induction of inflammation that is observed in obesity. Although our work is mostly in adipose tissue, through collaboration with colleagues in the department of animal sciences at Purdue and elsewhere, we are studying the regulation of inflammation in the gastrointestinal tract as well with a view to establishing the link between gut inflammation and efficiency of animal growth which includes impact on adiposity. We have a few published abstracts in this area in 2009. Specifically, we have worked on the modulation of inflammation in the gastrointestinal tract by non-antibiotic products like yeast under conditions of mild immune stimulation with a coccidia vaccine. <br /> <br /> <br /> Texas A&M University (Smith), objectives 1,2,3,7. There is a growing interest in documenting the effect of diet on the ability to convert saturated fatty acids (SFA) to monounsaturated fatty acids (MUFA) by modulating expression of the stearoyl-CoA desaturase (SCD) gene. We proposed that if cattle were raised to a constant body weight, their MUFA:SFA ratio would be the same regardless of being calf-fed (CF) or yearling-fed (YF). Twenty-four Angus steers were slaughtered at weaning at 8 mo of age (n = 4), eight steers were assigned to the CF group and slaughtered at 12 mo of age (n = 4) or 16 mo of age (n = 4). Twelve steers were assigned to the YF group and slaughtered at 12 mo of age (n = 4), 16 mo of age (n = 4) and market weight (525 kg; n = 4). Data were analyzed statistically based on time on high-energy diet with terminal age as a covariate and orthogonal polynomial contrasts were tested on the main effects of group and time. Yield grades increased over time in all steers (P < 0.01), and YF steers had higher yield grades than CF steers (P = 0.05). Histological sections of the LM were also taken to visualize the intramuscular fat development, and indicated that both the number of lipid-filled cells and the size of the lipid-filled cells increased in the LM i.m. adipose tissue depots. The slip point temperatures of the s.c. adipose tissue lipids decreased for all groups as time on feed increased (P < 0.01). The concentration of cholesterol in the longissimus muscle tended to be less in YF steers than in CF steers (P = 0.06). A trained sensory panel detected no significant differences between palatability of flavor characteristics of cooked steaks from intermediate CF steers and terminal CF and YF steers (P > 0.05).Digesta linoleic acid (18:2n-6) increased with time on the corn based diet in both groups, whereas digesta a-linolenic acid (18:3n-3) decreased over time (P < 0.01). Similarly, plasma linoleic acid increased over time on the corn-based diet; the digesta and plasma increases in linoleic acid were consistent with the contribution of linoleic acid from the corn-based finishing diet. Plasma MUFA and a-linolenic acid decreased over time in the finishing diet, decreased, primarily in the CF group. The percentage of i.m. lipid from the longissimus muscle (LM) increased over time (P < 0.01), regardless of group. In s.c. adipose tissue, palmitoleic acid (16:1n-7) increased over time (P < 0.01), and oleic acid (18:1n-9) increased at a faster rate in CF than in YF steers (TxG, P = 0.05). Correspondingly, the s.c. adipose tissue MUFA:SFA ratio increased over time (P < 0.01) but was not different between groups (P = 0.26). The i.m. adipose tissue MUFA:SFA ratio was higher in CF than in YF steers (P = 0.04). There was a quadratic response in s.c. adipose tissue SCD gene expression over time (P < 0.01), in that gene expression declined after 4 mo on the finishing diet in both the CF and YF steers (Figure 1). In i.m. adipose tissue, SCD gene expression declined in CF steers between 12 and 16 mo of age, but did not change in YF steers. This coincided with a slowing of the rate of accumulation of marbling in the CF steers, and a gradual increase in marbling in YF steers. We conclude that corn feeding increases marbling development and i.m. adipose tissue SCD gene expression, which was not achieved in the YF steers of this study.<br /> <br /> USDA ARS, Athens (Hausman), objectives 1,2,3,4,5,6,7,8,9,10. In this study, total RNA was collected from abdominal adipose tissue samples obtained from ten broiler chickens at 3, 4, 5, and 6 weeks of age and prepared for real time RT-PCR analysis. Studies of the gene expression of cytokines and associated genes in chicken adipose tissue were initiated since it has been shown in many animal species that adipose tissue derived factors can dramatically influence growth and physiology. The influence of age on the expression of adipose tissue IL-15, IL-8, neuropeptide Y and GHR and LPR genes and several other cytokines was examined. Between 3 and 6 weeks of age LPR expression decreased (P < 0.05) with age while expression of IL-15 and GHR increased significantly (P < 0.05). Furthermore, IL-8 and visfatin expression increased (P < 0.001) between 4 and 6 weeks of age. This is the first demonstration of age related changes in cytokine gene expression in chicken adipose tissue. Gene expression of several cytokines was not detected in chicken adipose tissue including IL-6 and brain derived neurotrophic factor. Future studies are needed to elucidate the role of adipose tissue cytokines in growth and, possibly, disease resistance. <br /> <br /> USDA ARS, Davis (Adams), objectives 1,2,4,5,6. Our laboratory focuses on the biology of adipose tissue, with the ultimate goal of applying this knowledge toward strategies to improve public health via nutritional and physical activity interventions. One aspect that is important to adipose tissue function and ultimately, whole-body insulin sensitivity, is inflammation, since low-grade inflammation in white adipose tissue (WAT) is often associated with obesity and this plays a role in insulin resistance. Such inflammation might be impacted by nutrition (at least in monogastrics), i.e., via increasing intakes of anti-inflammatory phytonutrients, limiting dietary saturated fat intake, limiting calories and hence excess body fat. Dietary calcium has been hypothesized to reduce WAT inflammation, but strong evidence for this from multiple laboratories is lacking. Epidemiological studies and research in animal models support an inverse relationship between dietary Ca and dairy food consumption with adiposity. Proposed mechanisms of adiposity reduction by dairy include decreased digestibility of fats due to formation of indigestible Ca soaps and dietary Ca suppression of calcitriol that alters energy metabolism and thermogenesis. Bioactive components from dairy protein are thought to have additional synergistic effects. We compared the effects of a high Ca (HC) diet vs. HC with nonfat dry milk (NFDM) on obesity phenotypes, including adipose tissue inflammation. Adult male C57BL/6J mice fed an obesigenic, pro-inflammatory high fat diet (45% kcal; HF) were assigned (n=30/group) to one of three macronutrient-matched HF diets for 12 wks: control (0.5% Ca; CON), HC (1.5% Ca), or HC with NFDM. Surprisingly, body weight and fat were increased ~18% and ~19% in HC mice vs. CON (P<0.001); these parameters decreased ~13% and ~43% in NFDM mice (P<0.001). Feed efficiency was significantly increased ~10% in HC mice and reduced ~33% in NFDM mice vs. CON. NFDM mice had improved glucose tolerance compared to both CON (P<0.01) and HC mice (P<0.001). Markers of adipose inflammation track the obesity and glucose homeostasis phenotypes (i.e., significantly increased in obesity, lowered by NFDM). We conclude that anti-obesity effects of dairy foods are not mediated by increased dietary Ca in high fat fed mice, and that inflammation and obesity phenotypes are not negatively correlated with calcitriol levels in the blood.<br /> <br /> Washington State University (Dodson), objectives 1,3,4,7. During 2008/2009 we have devised methods to isolate and quantitatively evaluate the dedifferentiation of individual mature (lipid-laden) adipocytes from pig-derived (subcutaneous and intramuscular) adipose tissues. We have determined that pig-derived adipocytes must extrude substantial lipid from the cell prior to becoming proliferative-competent. This single observation (of the need to physically rid itself of a majority of cytosolic lipid) is different to what we had previously observed in similar beef cow adipocyte cultures. Significance. We have been criticized that this process may never occur in vivo. Whether it does or doesn't remains to be seen. Instead, this system may be used to identify regulators of the dedifferentiation process, which might (in the future) be exploited for in vivo work. This system (as we have devised it) is novel and our goals are quite simple: to determine the regulation of the potential for adipocytes to either expand their presence in adipose tissue, or to transdifferentiate into other types of cells. In fact, as these cells possess ability to re-proliferate, they may not be traditional adipocytes (as most traditional biologists may have once thought). We are keeping an open mind. Results to support our research. Progeny cells (from beef cows) do NOT express the same gene profile (during a process to re-induce differentiation) as do primary preadipocytes or SV cells (papers published). This work is done in conjunction with researchers in Canada and in China, and is presently funded by a small grant from the University of Alberta. <br /> <br /> West Virginia University (Barnes), objectives 1,2,10. The primary goal of our laboratory is to understand the mechanism(s) of action of dietary conjugated linoleic acid-induced body fat loss. We have utilized a model of enhanced CLA responsiveness in mice raised from weaning, for 6 weeks prior to CLA supplementation, on diets deficient in polyunsaturated fatty acids (coconut oil or fat free). This year we have also investigated the effect of CLA on feed intake and pork marbling. As well, we have investigated the effect of different sources of DHA on body composition and serum lipids. Use of a mouse model for conjugated linoleic acid-induced changes in adipose depots. Dietary conjugated linoleic acid (CLA) has been reported to decrease backfat and increase marbling in pigs. The objective of this study was to determine the effect of CLA on lipid accumulation in mouse muscle. Male mice (n=80) were fed 7% soy oil (SO) or coconut oil (CO) diets for 6 wk, then 0 or 0.5% CLA was added for 12 d. A body fat index was calculated and muscle lipid content was determined by ether extraction. Fatty acid ² -oxidation was indicated by determining the enzyme activity of carnitine palmitoyl-transferase (CPT)-1. Body fat was reduced by CLA (P < 0.05). CLA caused a 28% decrease (P < 0.01) in thigh muscle lipid and a non-significant (P = 0.22) 24% decrease in back muscle lipid. CPT-1 activity in thigh muscle was decreased by CLA (P < 0.01) in SO-fed mice (80.94 vs. 14.27 EU/ mg protein) but not in CO-fed mice (38.86 vs. 12.49 EU/ mg protein). <br /> <br /> University of Wyoming (Du, Rule), objectives 1,2,3,4,5,6,7,8,9,10. The interrelationship between diet, fetal growth and muscle and fat development are currently the focus of research at the University of Wyoming, Department of Animal Science relating to regulation of adipose tissue growth in meat animals, the focus of NCCC-021. Min Dus research addresses regulation of fetal muscle and adipose tissue development with AMPK as the focal point of this regulation. Dan Rules research has emphasized how diet, in particular grass fed beef, affects the lipid composition of muscle and adipose tissue of beef cattle. This years station report from the University of Wyoming will address these two areas. AMPK in regulation of fetal tissue development (Dr. Min Du). Fetal skeletal muscle development associated with myogenesis, adipogenesis and fibrogenesis from mesenchymal stem cells. We have continued to our effort to define the role of AMP-activated protein kinase (AMPK) in mesenchymal stem cell differentiation and fetal skeletal muscle development. Our studies show that AMPK activity is negatively associated with adipogenesis and fibrogenesis, but positively correlated with myogenesis. We also found that AMPK regulates mesenchymal stem cell differentiation through phosphorylating ²-catenin at Ser 552 which improves the stability and transcriptional activity of ²-catenin. Inhibition of AMPK enhanced adipogenesis. The Wnt/ ²-catenin signaling pathway is known to enhance myogenesis but inhibits adipogenesis. <br /> <br /> Auburn University (Bergen). We have continued to screen mRNA abundance in skeletal muscles and subcutaneous adipose tissues of key target genes involved with lipid accretion (PPAR³, fatty acid synthase, SREBP-1c, SCD), fat catabolism and the role of uncoupling proteins (PPAR±, Acyl CoA dehydrogenase,-beta oxidation, UCP) and protein metabolism (key genes in the proteasomal pathway) in cattle under varying production systems in the Southeast. Our current set of samples are from a heifer finishing study with a single 30 day Optaflexx supplementation starting at 300kg at 50 kg increments to 500 kg. . The results are still incomplete and will be available next year. Other efforts are to garner preliminary data for the new USDA/AFRI priorities in animal agriculture competitive grants program. We are mostly focused on adipocyte biology in vivo as related to climate change and high/low ambient temperatures. <br />

Publications

Impact Statements

1. Research advanced the understanding of the causes of childhood and adult obesity.
2. Better understanding of the impact and mechanism of fetal programming and effect on later onset obesity

Back to top

Report Information

Participants

Brief Summary of Minutes

Accomplishments

Washington Station (Dodson). 2010 was an interesting year for me. I spent considerable time working on collaborative projects, writing survey/review-type papers as a direct result of simply thinking about the "status" of the research field, and/or generating information about the productivity/impact of my research program for internal assessment. Considering the change in direction of some federal granting agencies, re-strategizing about where/how to submit grant proposals to a variety of granting agencies occupied much of my remaining time. Moreover, I tried to assemble interested individuals to work with me on a variety of collaborative projects in 2010--carried over to 2011. For the most part, however, I would consider my data-generating efforts to be minimal in 2010...especially considering that I was away from the laboratory for 2 months due to medical leave. Regardless, perhaps my best 2010/2011 accomplishment was to work with Sylvia, Gary and Werner to nominate specific members of this committee for ASAS awards for 2011.<br /> <br /> <br /> Georgia Station (Azain). Increased consumption of fructose has been suggested as a basis for increased rates of obesity in humans. Rodent studies have shown an increase in de novo lipogenesis and decreased insulin sensitivity in response to feeding high levels of fructose, but it is unclear if these effects occur in the same progression in humans. The use of the pig as a model for the human may be more appropriate than the rodent, as pigs and humans have similar GIT physiology and nutrient metabolism. Two experiments were conducted to determine if the source of dietary carbohydrate, with or without added fat, had an effect on body weight gain, glucose metabolism, or insulin response in growing pigs. In the first experiment, pigs (24 barrows, initial body weight 28 kg) were fed one of four diets where the source of carbohydrate was varied: 1) 20% starch; 2) 10% glucose + 10% starch; 3) 10% fructose + 10% starch; and 4) 20% fructose for 9 weeks. An intravenous glucose tolerance test (i.v.GTT) and response to meal (RTM) test were conducted at the end of 9 wks. Blood was analyzed for glucose, fructose, insulin, leptin, TG, and cholesterol concentrations. Dietary treatment had no effect on growth performance or carcass characteristics. Pigs fed the 10% fructose diet tended to have the lowest glucose area under the curve during the GTT (P=0.07). Otherwise, there were no differences in glucose tolerance, insulin, or other metabolites. Serum fructose concentrations after the RTM test were elevated in pigs fed fructose diets. <br /> Experiment 2 was conducted as a 3 x 2 factorial with main effects of carbohydrate source (Starch, Glucose, Fructose) and fat level (0 vs 10%). Pigs (24 barrows, initial body weight 71 kg) were fed one of six experimental diets for 9 weeks. As in the first experiment, there were no differences in growth rate or carcass characteristics. As would be expected, there was a main effect of dietary fat to reduce feed intake. There was a CHO x Fat interaction for serum glucose and insulin during the GTT. Compared to the other dietary treatments, pigs fed fructose with high fat had an elevated glucose area under the curve during the GTT (CHO x Fat interaction, P< 0.01). This same group had a lower insulin response (CHO x Fat, P < 0.05). As in experiment 1, serum fructose after the RTM test was elevated in the fructose fed pigs. It is likely that studies of longer duration are needed to determine if these changes are indicative of insulin resistance. The work demonstrates that pigs can be a viable model to test long-term effects of dietary carbohydrates on metabolism and body composition.<br /> <br /> <br /> Alabama Station (Bergen). During the past year we have continued our focus on the molecular determinants of depot specific adipose accretion in beef cattle. We have continued to analyze expression patterns of putative and novel regulatory genes responsible for lipid and protein metabolism in economically relevant tissues. In one study weve examined the effect of days on feed and Beta-agonist administration on gene expression patterns in finishing heifers (see abstract below). In another study we looked at the effects of forage finishing on the expression of key regulatory factors in beef steers using serial adipose and skeletal muscle biopsies during the finishing phase. In general we have determined that depot-specific, temporal changes in gene expression may contribute to phenotypic variation in overall and intramuscular adiposity.<br /> <br /> <br /> The Effect Of Days On Feed and Beta-Agonist Administration On The Expression Of Adipocyte-Specific Regulatory Genes in Skeletal Muscle and Adipose Tissue of Finishing Heifers. FASEB J. April 2011 25 (Meeting Abstract Supplement) 985.4 <br /> <br /> <br /> The development of marbling (Intramuscular fat; IMF) is an economically relevant trait that is mediated at the molecular level of adipose tissue metabolism. The objective of the current research was to evaluate adipose-specific regulatory genes in skeletal muscle IMF, and adipose depots of finishing heifers. Gastrocnemius Muscle (GM), Longissimus Dorsi Muscle (LM), and subcutaneous adipose tissue (AT) were collected after heifers were on feed for 79, 121, and 163 days and treated with (BAA) or without (Control) beta-agonist for the final 30d of feeding, respectively. Quantitative Real-Time PCR was used for gene expression analysis. Pref-1 expression was highest in the initial slaughter group (P<0.05), and decreased as time on feed increased. LM showed decreased Pref-1 expression relative to GM indicating an increased IMF adipogenic capacity in this muscle depot. BAA treatment appeared to decrease Pref-1 expression in both LM and GM. Subcutaneous AT showed increased Pref-1 expression relative to LM (P<0.05) when treatments within slaughter groups were combined, but when individual tissues and treatments were compared, there was no difference between LM and AT (P>0.05), while the GM showed higher expression (P<0.05) relative to AT and LM. This study showed a temporal Pref-1 expression pattern that appears to be consistent with the paradigm of late development of the IMF depot.<br /> <br /> <br /> The effects of compensatory growth on gene expression patterns in the loin muscle and subcutaneous adipose tissue of forage fed beef. <br /> <br /> The purpose of this project was to determine the effects of different levels of growth on beef steers. To this end 48 steers were subjected to one of four feeding regimens consisting of either dormant pasture or growing ryegrass for different durations during the trial period (See figure below). Skeletal muscle (Longissimus dorsi) and adipose tissue biopsy samples were collected every 42 days (d42, d84, and d126) for gene expression analysis. Loin muscle, gastrocnemius muscle, and subcutaneous fat samples were also collected at slaughter to determine depot specific patterns of gene expression as affected by different levels of available energy during the forage-finishing period. Data analysis for this study is currently underway.<br /> <br /> <br /> Ohio Station (Lee). We found that amounts of ATGL protein could not perfectly reflect lipolytic activities, suggesting other regulatory mechanisms are involved in these processes. We demonstrated that ATGL-medicated lipolysis is regulated by modulation of other proteins, an activator and inhibitor of ATGL protein in chicken adipose tissue. The genes encoding activator and inhibitor proteins (CGI-58 and G0S2 genes) were successfully cloned for chickens, turkeys and quail and reported in the Genbank. The hormonal, developmental and nutritional regulation of these genes in adipose tissue was performed to relate the function of these genes in lipolysis of the avian species (JAS papers). We are currently working on generation of transgenic quail expressing these genes under the adipose-specific promoter to study interaction of these genes in the regulation of lipolysis. <br /> <br /> <br /> We recently cloned bovine ATGL cDNA for several different breeds and characterize the ATGL gene expression in various cattle tissues. We also investigated the expression of genes involved in lipid metabolism in the muscle of cattle fed a flaxseed supplement (FS). We found supplemented animals had a greater triglyceride content in the muscle compared with unsupplemented, increasing marbling. Dietary supplementation, with flaxseed meal containing a greater amount of omega-3 fatty acids, alters muscle fat content with associated changes in the expression of genes (A-FABP, ATGL and SCD1) involved in lipid metabolism within the skeletal muscle. The results from these studies were published in Lipids.<br /> <br /> <br /> In general, genomic imprinting is an important regulatory mechanism of gene expression either from the maternal or paternal allele. Dlk1, a gene responsible for muscle hypertrophy of callipyge sheep, is an imprinted gene that is expressed from the paternal allele in mammals. Like other imprinted genes found in the cluster, Dlk1 is found in the conserved synteny of the imprinted gene cluster, called the Dlk1-Dio3 cluster in mammals. However, the imprinting status of Dlk1 in the avian species has not been reported and conservation of the chicken orthologue of the mammalian imprinted gene cluster has not been studied yet. The objective of this experiment was to clone Dlk1 cDNAs for turkeys and quail, and to determine the genomic structure of the cluster in the chicken and the imprinting status of avian Dlk1 genes. Our data clearly demonstrated the avian Dlk1 genes are expressed from both the paternal and maternal allele and are not subject to genomic imprinting. We provide evidence supporting the evolvement of genomic imprinting only in mammals after the divergence of mammals and birds (PS paper). In addition, transgene expression between different founders of quail can be regulated by methylation status of the transgene (Mol. Biotechnol.) <br /> <br /> <br /> I have been leading the collaborative work in the area of brown adipose tissue metabolism during cold stress. This study focuses on the cellular signaling events, as well as the gene expression changes associated with the alterations to lipid metabolism in the brown adipose tissue of mice when they are exposed to extreme cold. This research has significant implications in the study of human obesity and diabetes; activation of the heat generating system within mammals increases metabolic inefficiency, thus, allowing the burning of fat to create heat (Lipids paper).<br /> <br /> <br /> West Virginia Station (Barnes). The primary goal of our laboratory is to understand the mechanism(s) of action of dietary conjugated linoleic acid-induced body fat loss. We have utilized a model of enhanced CLA responsiveness in mice raised from weaning, for 6 weeks prior to CLA supplementation, on diets deficient in polyunsaturated fatty acids (coconut oil). As well, we have investigated the effect of different sources of DHA on body composition and serum lipids and the effect of CLA on pork marbling. Major findings from this years work include: 1. CLA increases lipolysis in coconut oil-fed mice more rapidly than in soy oil-fed mice, 2 Algal oil must be fed at a greater dietary DHA concentration than fish oil to achieve equal tissue DHA concentrations. And a dose of algal oil that resulted in greater tissue DHA concentration was required to achieve similar reductions in serum triacylglycerol and cholesterol, 3. Increases in loin lipid content in CLA-fed pigs may involve increased intramuscular adipocyte size.<br /> <br /> <br /> Time-dependent effect of conjugated linoleic acid-induced body fat loss and lipolysis in coconut oil fed mice. SiriManasa Ippagunta and Kimberly M. Barnes<br /> To be presented at Experimental Biology, April 10, 2011 Abst #109.2.<br /> Dietary conjugated linoleic acid (CLA) causes a body fat loss that is enhanced when mice are fed coconut oil (CO). The objective was to determine if there is a time-dependent effect of CLA feeding on lipolysis. Male mice (ICR; n=80; 3wk-old) were fed 7% SO or CO diets for 6wk then 0 or 0.5% CLA for 3, 7, 10 or 14d. A body fat index (BFI) was calculated and lipolysis was determined ex vivo by NEFA and glycerol release from adipose tissue. The relative expression of perilipin and phosphorylated perilipin (P-perilipin) were determined by western blotting. The BFI was reduced by CO on d7 (P<0.01), and by both CLA (P<0.05) and CO (P<0.05) on d14. NEFA release was increased by CLA in CO-fed mice (1.84 vs 7.93 µmol/g; P<0.01) but not in SO-fed mice (1.64 vs 2.03 µmol/g) on d7 but on d14 CLA increased NEFA release in both CO (2.83 vs 6.16 µmol/g) and SO-fed mice (2.01 vs 4.99 µmol/g). Glycerol release was increased by CLA in CO-fed mice but not in SO-fed mice on d3 and d7 (P<0.05). P-perilipin was not altered by diet but total perilipin tended to be increased by CLA in CO-fed mice (P=0.055) on d7. Therefore CLA-induced lipolysis may occur more rapidly in CO vs SO-fed mice but appears to be transitory.<br /> <br /> Effect of high docosahexaenoic acid-algal oil on body fat and serum lipids in mice<br /> Abigail G. Shelton, Ralph A. Pietrofesa, Michael Azain, and Kimberly M. Barnes <br /> To be presented at Experimental Biology, April 10, 2011 Abst #586.5.<br /> Algal oil (AO) contains a high content of docosahexaenoic acid (DHA) but no eicosapentaenoic acid (EPA), unlike fish oil (FO) which has both DHA and EPA. AO, fed at equal DHA levels, was not as effective as FO at reducing body fat or serum lipids. Our objective was to determine the dose response of AO vs FO on body fat and serum lipids. Male mice (ICR; n=94; 9-wk-old) were fed a 12% lipid diet containing 0 (soy oil; SO), 10 (FO or AO-10), 20 (AO-20), 35 (AO-35), or 50 (AO-50) g/kg DHA for 2 or 4 wks. A body fat index (BFI) was calculated, serum lipids, adipose fatty acid profile, and proximate composition of the carcasses were determined. At 2 wk FO-fed mice were leaner (p<0.01) than SO-fed mice, with all AO-fed mice intermediate. No differences in body composition were observed at 4 wk. FO and all AO doses reduced (p<0.05) serum triglycerides and cholesterol at 2 wk but only AO-35, AO-50, and FO reduced (p<0.001) cholesterol at 4 wk. Tissue DHA was similar between FO, AO-10, and AO-20-fed mice, with AO-35 and AO-50-fed mice having greater (p<0.001) tissue DHA. Therefore, algal oil appears to not be as effective as fish oil in decreasing body fat and serum lipids. <br /> <br /> <br /> Iowa Station (Beitz). The current study was designed to identity polymorphisms in the genes involved in milk lipid biosynthesis to provide animal breeders with tools that allow selection of animals producing milk with healthier fatty acid composition. High concentrations of saturated fatty acids (SFA) in human diets are known to increase plasma cholesterol concentrations and, as a result, increase the risk of developing cardiovascular diseases (CVD), the number one cause of death worldwide. Because bovine milk is one of the primary sources of SFA and individual atherogenic fatty acids such as palmitic (16:0) and myristic (14:0) in human diets the improvement of the healthfulness of milk through selection becomes one of the primary measures that has been taken with the intention of decreasing the incidence of CVD among humans.<br /> <br /> <br /> The candidate gene approach was used to address the objectives of the study. Genes involved in milk triacylglycerol (TAG) biosynthesis, fatty acid uptake into mammary gland and fatty acid transport inside the mammary epithelial cells, and transcriptional regulation of some lipogenic genes were investigated. DNA sequencing was used to discover single nucleotide polymorphisms (SNPs) in the genes of interest. After genotyping animals on the study for the discovered SNPs, the intragenic haplotypes were reconstructed and tested for the association with milk fatty acid composition.<br /> <br /> <br /> The glycerol-3-phosphate acyltransferases-1 and -4 (GPAT1 and GPAT4), 1-acylglycerol-3-phosphate acyltransferase-1 (AGPAT1), and phosphatidate phosphatase (LPIN1) genes from the TAG biosynthetic pathway were studied in the first set of experiments to test the associations of the polymorphisms in those genes with milk fatty acid composition. The polymorphisms in GPAT4 were associated with large differences in atherogenic index (AI), concentrations of SFA, unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), SFA/UFA, concentrations of capric (10:0), lauric (12:0), palmitic (16:0), and oleic (18:1 c9 ) acids, CLA (18:2 c9, t11 ), C16 and C18 desaturation indices in milk. The size of the effects of GPAT4 polymorphisms for some of the traits was numerically at least the same or larger compared with the effect of DGAT1 A232K mutation, making the polymorphisms in GPAAT4 to be a very valuable tool for the improvement of the healthfulness of milk. Other polymorphisms significantly associated with the studied traits in the first set of experiments were in GPAT1 for milk fat percentage, concentrations of short- and medium-chain SFA, and myristoleic (14:1 c9 ) acid concentration, and in AGPAT1 for the concentrations of linoleic (18:2 c9, c12 ) acid and other UFA. The polymorphisms in GPAT1 can be used to select for animals producing milk with higher percentage of fat and desirable concentrations of short- and medium-chain SFA. The polymorphisms in AGPAT1 can be used to select for animals producing milk with higher concentration of UFA and linoleic (18:2 c9, c12 ) acid, in particular.<br /> <br /> In the second set of experiments, the polymorphisms in the solute carrier family 27 (SLC27A6), isoform A6 and fatty acid binding proteins-3 and -4 (FABP3 and FABP4) genes involved in fatty acid uptake into mammary gland and fatty acid transport inside the mammary epithelial cells were tested for the association with milk fatty acid composition. The haplotype effects of SLC27A6 were associated significantly with milk fat percentage, AI, the concentrations of SFA, UFA, MUFA, SFA/UFA, the concentrations of capric (10:0), lauric (12:0), myristic (14:0), and palmitic (16:0) acids. The size of the haplotype effects of SLC27A6 on the studied traits was large and numerically similar to the size of allelic effects of DGAT1 A232K mutation that makes the polymorphisms in SLC27A6 as valuable as the of DGAT1 A232K mutation to select for animals producing milk with higher fat percentage and healthier fatty acid composition. The haplotype effects of FABP4 were associated significantly with the concentrations of SFA, UFA, MUFA, PUFA, SFA/UFA, the concentrations of linoleic (18:2 c9, c12 ) acid, CLA (18:2 c9, t11 ), and C18 desaturation index.<br /> <br /> The sterol regulatory element binding protein-1c (SREBP-1c) is involved in the transcriptional regulation of lipogenesis and its proteolytic activation is controlled by SREBP cleavage-activating protein (SCAP) and insulin-induced genes (Insig) that are all part of the SREBP pathway. In the third set of experiments, the significant association of the overall haplotype effect of SREBP1 with the concentrations of myristic (14:0), myristoleic (14:1 c9 ) acids, and C14 desaturation index were detected. The overall haplotype effect of Insig1 was associated with the concentrations of PUFA and linoleic (18:2 c9, c12 ) acid. There were no significant associations with milk fatty acid composition determined for SCAP.<br /> In conclusion, we were able to identify polymorphisms in a number of genes that were associated significantly with milk fat percentage and fatty acid composition. The information about those polymorphisms can be used to select for animals producing healthier milk.<br /> <br /> <br /> Wyoming Station (Du). AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism; it is inhibited under obese conditions and is activated by exercise and by many anti-diabetic drugs. Emerging evidence also suggests that AMPK regulates cell differentiation including adipogenesis, but the underlying mechanisms are unclear. ²-Catenin is a key mediator of Wingless and Int (Wnt)/²-catenin signaling pathway, which is required for early embryonic development, cell proliferation, and differentiation, and activation of b-catenin signaling pathway inhibits adipogenesis. We postulate that AMPK regulates adipogenesis through cross-talk with Wnt/²-catenin signaling pathway. We previously observed that AMPK phosphorylates b-catenin, which enhances b-catenin stability. Here, we further show that AMPK also regulates b-catenin expression. <br /> <br /> <br /> Epigenetic modifications including histone acetylation and methylation, and DNA methylation, regulate gene transcription. Histone acetylation is regulated by histone acetyltransferase (HAT) and histone deacetylase (HDAC). HDAC5 belongs to the class IIa HDAC family, and acts as a conserved transcriptional repressor. HDAC5 interacts with myocyte enhancer factor-2 (MEF2) to target specific gene promoters. We identified a MEF2 binding site on the b-catenin promoter. These data prompted us to hypothesize that AMPK regulates b-catenin expression through phosphorylation of HDAC5. Here, we present data showing that AMPK phosphorylates HDAC5, which promotes its nuclear export, leading to the acetylation of histones that are bound to the b-catenin promoter and enhanced b-catenin expression<br /> <br /> <br /> In both C3H10T1/2 cells and mouse embryonic fibroblasts (MEFs), AMPK activity was positively correlated with b-catenin content. Chemical inhibition of HDAC5 increased b-catenin mRNA expression. HDAC5 over-expression reduced and HDAC5 knockdown increased H3K9 acetylation and cellular b-catenin content. HDAC5 formed a complex with myocyte enhancer factor-2 (MEF2) to down-regulate b-catenin mRNA expression. AMPK phosphorylated HDAC5, which promoted HDAC5 exportation from the nucleus; mutation of two phosphorylation sites in HDAC5, Ser 259 and 498, abolished the regulatory role of AMPK on b-catenin expression. In conclusion, AMPK promotes b-catenin expression through phosphorylation of HDAC5, which reduces HDAC5 interaction with the b-catenin promoter via MEF2. Thus, the data indicate that AMPK regulates cell differentiation and adipogenesis via cross-talk with the wingless and Int (Wnt)/b-catenin signaling pathway.<br /> <br /> <br /> Wyoming Station (Rule). Our hypothesis was dietary rumen-protected n -3 PUFA will increase concentrations of these fatty acids in tissues of grass-fed beef cattle. Forty half-blood LowLine Angus steers (290.5 ± 6.6 kg initial BW) were allotted to either a control (CON; no supplemental fat), saturated fatty acid Ca salt (SAT), or fish oil fatty acid Ca salt (N3) treatment in a completely randomized designed experiment. Beet pulp supplements that contained 7.6% molasses, 4.0% CaCO3 for CON, 4.4% mineral mix, and 1.8% Poloxalene were individually fed and formulated to provide 0.25% of BW as supplement and 2.0% of DM as fat for SAT and N3. Irrigated pasture consisted of 25% bromegrass, 25% wheatgrass, and 50% alfalfa (CP = 20.9%; 36.7 kg DM " head-1 " d-1), and was rotated weekly from June 1 through October 15, 2008 when steers were fed forage harvested from the same pastures until December 8. Blood was sampled at 45 and 93 d. Steers were shipped 137 km for slaughter at a commercial plant; liver was sampled upon evisceration. Twelve days post mortem, 100 g each of longissimus (12th rib), supraspinatus, and semitendinosus muscles were obtained. Fatty acids extracted from serum, liver, and muscles were analyzed by GLC with C13:0 as internal standard. In liver compared with CON, SAT caused increased (P < 0.01) C16:0, C18:0, C18:1 n-9, C18:2 n-6, C20:3 n-3, and C20:4 n-6, and decreased (P = 0.01) C18:3 n-3. Compared with CON, N3 supplementation resulted in greater (P < 0.01) C18:1 t-11, C20:5 n-3 (eicospentaenoic acid, EPA) and C22:6 n-3 (docoshexaenoic acid, DHA), and less (P < 0.01) C18:1 n-9, C18:2 n-6, C20:3 n-3, C20:4 n-6 in liver. In muscle, concentrations of C18:2 n-6 and C20:4 n-6 increased (P < 0.01) for SAT compared with CON. For each muscle, N3 resulted in greater (P < 0.01) EPA and DHA compared with CON. Serum concentrations of fatty acids reflected differences in supplemental intake of C16:0 and C18:1 n-9 of SAT, as well as EPA and DHA of N3. Overall, supplementation of N3 resulted in 86.4% and 85.6% increases in concentration of EPA + DHA in liver and muscle, respectively.<br /> <br /> <br /> Taiwan Station (Ding). My group emphasized on the regulation of genes related to adipose function and obesity. We have established the nutritional regulation of DHA on the expression of metabolism related genes. We have also delineated the mechanism by which PUFA regulate fat deposition. Several regulation cascades, ie., serum amyloid protein, FoxO, and C/EBPbeta were found to mediate the PUFA effects.<br /> <br /> <br /> <br /> Indiana Station (Purdue- Ajuwon). In 2010 our research team continued our work on the role of adipose tissue extracellular matrix in the regulation of adipose tissue function and on the factors that regulate the turnover of adipose tissue extracellular matrix during diet induced obesity. In 2010, we determined the changes in adipose tissue matrix proteoglycans and collagens in response to high fat diet, acute or chronic inflammation. Our finding is that acute inflammation does not play a major role in regulation ECM gene expression, even though it does lead to significant upregulation of inflammatory genes. However, obesity induced by high fat diet feeding leads to induction of extracellular matrix gene expression determined by RT-PCR. However, western blot analysis of collagen 1a1, a major adipose tissue collagen shows reduction in this protein in obesity in humans and mice, despite an upregulation of its mRNA level. This discordance between mRNA abundance and protein level suggests a high turnover of the protein that cannot be matched by the increased mRNA abundance. This study demonstrates the importance of ECM breakdown machinery, mediated by matrix metalloproteases and other matrix degrading enzymes, in regulating the abundance of ECM proteins. We have also determined that ECM proteoglycans such as decorin and biglycan play important roles in the regulation of preadipocyte proliferation and apoptosis. Both decorin and biglycan inhibit adipocyte proliferation. However, biglycan is more proapototic than decorin. The implication of this finding is that the abundance of specific ECM proteins may determine the overall ability of adipose tissue to enlarge via the regulation of the proliferation and apoptotic rates of preadipocytes. Finally, we determined the anti-inflammatory function of secretory leucocyte protease inhibitor (SLPI) in adipose tissue. We found out the SLPI is regulated by obesity and exerts anti-inflammatory function in adipocytes.<br /> <br /> <br />

Publications

Impact Statements

1. Research advanced the understanding of the genetic and nutritional regulation of adipocyte development and body composition.
2. Better understanding of the genes in regulation of lipid breakdown in adipose tissue and of lipid synthesis in milk.

Back to top

Report Information

Participants

Brief Summary of Minutes

Please see attached "Copy of Minutes" document for NCCC210's full annual report.

Accomplishments

Publications

Impact Statements

Back to top

Report Information

Participants

Brief Summary of Minutes

Please see attached "Copy of Minutes" file below for NCCC201's 2012/2013 annual report

Accomplishments

Publications

Impact Statements

Back to top

Report Information

Participants

Brief Summary of Minutes

See attached copy of minutes file below for NCCC210's 2013/2014 annual report.

Accomplishments

Publications

Impact Statements

Back to top

Report Information

Participants

Brief Summary of Minutes

NCCC210's 2014 annual report attached below.

Accomplishments

Publications

Impact Statements

Back to top