Obesity and Metabolism Research Unit

Davis, CA, United States

Obesity and Metabolism Research Unit

Davis, CA, United States
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Mostaedi R.,University of California at Davis | Lackey D.E.,Obesity and Metabolism Research Unit | Adams S.H.,Obesity and Metabolism Research Unit | Adams S.H.,University of California at Davis | And 3 more authors.
Obesity Surgery | Year: 2014

Background: Pharmacotherapy is considered the primary treatment modality for diabetes mellitus (DM), hypertension (HTN), and dyslipidemia (DYS). We sought to investigate the status of DM, HTN, and DYS in patients who seek bariatric surgery. Methods: Demographic and comorbidity history were prospectively collected on 1,508 patients referred for bariatric consultation at a single institution from February 2008 to March 2012. We utilized published consensus guidelines (GL) to benchmark the efficacy of standard pharmacotherapy for these metabolic diseases, and 881 patients met the study design criteria. Results: Most patients exhibited at least one form of metabolic dysregulation (pre-DM or DM, 75.8 %; pre-HTN or HTN, 91.1 %; pre-DYS or DYS, 84.0 %; metabolic syndrome, 76.0 %). The majority of patients either did not meet GL treatment goals (DM, 45.7 %; HTN, 39.5 %; DYS, 22.3 %) or were previously undiagnosed (DM, 15.8 %; HTN, 13.7 %; DYS, 41.7 %). Non-GL pharmacotherapy was significantly less effective than GL pharmacotherapy at achieving treatment goals for DM (31.8 vs 53.2 %, p < 0.001) and HTN (43.6 vs 63.2 %, p = 0.007). Patients with concurrent DM, HTN, and DYS (35.5 %) were less likely than patients with only one or two of these metabolic diseases to achieve GL treatment goals for HTN (38.1 vs 72.6 %, p < 0.001) and DYS (55.7 vs 73.8 %, p = 0.002). Only 8.0 % of these patients achieved treatment goals for all three metabolic comorbidities. Conclusions: In this patient group, DM, HTN, and DYS were poorly compensated, even when pharmacotherapy was consistent with published GL. This may be due to disease burden in bariatric surgery candidates or to inadequate medical management prior to presentation. © 2014 Springer Science+Business Media New York.

McCoin C.S.,University of California at Davis | Knotts T.A.,Obesity and Metabolism Research Unit | Knotts T.A.,University of California at Davis | Ono-Moore K.D.,Obesity and Metabolism Research Unit | And 3 more authors.
American Journal of Physiology - Endocrinology and Metabolism | Year: 2015

Acylcarnitines, important lipid biomarkers reflective of acyl-CoA status, are metabolites that possess bioactive and inflammatory properties. This study examined the potential for long-chain acylcarnitines to activate cellular inflammatory, stress, and death pathways in a skeletal muscle model. Differentiated C2C12 myotubes treated with L-C14, C16, C18, and C18:1 carnitine displayed dose-dependent increases in IL-6 production with a concomitant rise in markers of cell permeability and death, which was not observed for shorter chain lengths. L-C16 carnitine, used as a representative long-chain acylcarnitine at initial extracellular concentrations ≥25 μM, increased IL-6 production 4.1-, 14.9-, and 31.4-fold over vehicle at 25, 50, and 100 μM. Additionally, L-C16 carnitine activated c-Jun NH2-terminal kinase, extracellular signalregulated kinase, and p38 mitogen-activated protein kinase between 2.5- and 11-fold and induced cell injury and death within 6 h with modest activation of the apoptotic caspase-3 protein. L-C16 carnitine rapidly increased intracellular calcium, most clearly by 10 μM, implicating calcium as a potential mechanism for some activities of long-chain acylcarnitines. The intracellular calcium chelator BAPTA-AM blunted L-C16 carnitine-mediated IL-6 production by >65%. However, BAPTA-AM did not attenuate cell permeability and death responses, indicating that these outcomes are calcium independent. The 16-carbon zwitterionic compound amidosulfobetaine-16 qualitatively mimicked the L-C16 carnitineassociated cell stress outcomes, suggesting that the effects of high experimental concentrations of long-chain acylcarnitines are through membrane disruption. Herein, a model is proposed in which acylcarnitine cell membrane interactions take place along a spectrum of cellular concentrations encountered in physiologicalto- pathophysiological conditions, thus regulating function of membrane- based systems and impacting cell biology. © 2015 the American Physiological Society.

Thomas A.P.,University of California at Davis | Dunn T.N.,University of California at Davis | Drayton J.B.,University of California at Davis | Oort P.J.,Obesity and Metabolism Research Unit | And 2 more authors.
Nutrition and Metabolism | Year: 2012

Background: High dietary calcium (Ca) is reported to have anti-obesity and anti-inflammatory properties. Evidence for these properties of dietary Ca in animal models of polygenic obesity have been confounded by the inclusion of dairy food components in experimental diets; thus, effect of Ca per se could not be deciphered. Furthermore, potential anti-inflammatory actions of Ca in vivo could not be dissociated from reduced adiposity. Methods. We characterized adiposity along with metabolic and inflammatory phenotypes in diet-induced obese (DIO) mice fed 1 of 3 high fat diets (45% energy) for 12 wk: control (n = 29), high-Ca (n = 30), or high-Ca + nonfat dry milk (NFDM) (n = 30). Results: Mice fed high-Ca + NFDM had reduced body weight and adiposity compared to high-Ca mice (P < 0.001). Surprisingly, the high-Ca mice had increased adiposity compared to lower-Ca controls (P < 0.001). Hyperphagia and increased feed efficiency contributed to obesity development in high-Ca mice, in contrast to NFDM mice that displayed significantly reduced weight gain despite higher energy intake compared to controls (P < 0.001). mRNA markers of macrophages (e.g., CD68, CD11d) strongly correlated with body weight in all diet treatment groups, and most treatment differences in WAT inflammatory factor mRNA abundances were lost when controlling for body weight gain as a covariate. Conclusions: The results indicate that high dietary Ca is not sufficient to dampen obesity-related phenotypes in DIO mice, and in fact exacerbates weight gain and hyperphagia. The data further suggest that putative anti-obesity properties of dairy emanate from food components beyond Ca. © 2012 Thomas et al; licensee BioMed Central Ltd.

Grapov D.,University of California at Davis | Grapov D.,Obesity and Metabolism Research Unit | Adams S.H.,University of California at Davis | Adams S.H.,Obesity and Metabolism Research Unit | And 4 more authors.
PLoS ONE | Year: 2012

Type 2 diabetes has profound effects on metabolism that can be detected in plasma. While increases in circulating non-esterified fatty acids (NEFA) are well-described in diabetes, effects on signaling lipids have received little attention. Oxylipins and endocannabinoids are classes of bioactive fatty acid metabolites with many structural members that influence insulin signaling, adipose function and inflammation through autocrine, paracrine and endocrine mechanisms. To link diabetes-associated changes in plasma NEFA and signaling lipids, we quantitatively targeted >150 plasma lipidome components in age- and body mass index-matched, overweight to obese, non-diabetic (n = 12) and type 2 diabetic (n = 43) African-American women. Diabetes related NEFA patterns indicated ~60% increase in steroyl-CoA desaturase activity and ~40% decrease in very long chain polyunsaturated fatty acid chain shortening, patterns previously associated with the development of nonalcoholic fatty liver disease. Further, epoxides and ketones of eighteen carbon polyunsaturated fatty acids were elevated >80% in diabetes and strongly correlated with changes in NEFA, consistent with their liberation during adipose lipolysis. Endocannabinoid behavior differed by class with diabetes increasing an array of N-acylethanolamides which were positively correlated with pro-inflammatory 5-lipooxygenase-derived metabolites, while monoacylglycerols were negatively correlated with body mass. These results clearly show that diabetes not only results in an increase in plasma NEFA, but shifts the plasma lipidomic profiles in ways that reflect the biochemical and physiological changes of this pathological state which are independent of obesity associated changes.

Bedinger D.H.,XOMA | Bedinger D.H.,University of California at Davis | Goldfine I.D.,XOMA | Corbin J.A.,XOMA | And 3 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2015

The monoclonal antibody XMetA is an allosteric partial agonist of the insulin receptor (IR), which activates the metabolic Akt kinase signaling pathway while having little or no effect on the mitogenic extracellular signal-regulated kinase (ERK) signaling pathway. To investigate the nature of this selective signaling, we have conducted a detailed investigation of XMetA to evaluate specific phosphorylation and activation of IR, Akt, and ERK in Chinese hamster ovary cell lines expressing either the short or long isoform of the human IR. Insulin activated both pathways, but the phosphorylation of Akt was more sensitive to the hormone than the phosphorylation of ERK. Maximally effective concentrations of XMetA elicited phosphorylation patterns similar to 40-100 pM insulin, which were sufficient for robust Akt phosphorylation, but had little effect on ERK phosphorylation. These data indicate that the preferential signaling of XMetA is due to an innate difference in pathway sensitivity of Akt versus ERK responses to IR activation and partial agonism by XMetA, rather than a separate pathwaybiased mechanism. The metabolic selectivity of partial IR agonists like XMetA, if recapitulated in vivo, may be a desirable feature of therapeutic agents designed to regulate blood glucose levels while minimizing undesirable outcomes of excessive IR mitogenic activation.

Aguer C.,University of Ottawa | McCoin C.S.,University of California at Davis | McCoin C.S.,Obesity and Metabolism Research Unit | Knotts T.A.,Obesity and Metabolism Research Unit | And 11 more authors.
FASEB Journal | Year: 2015

Insulin resistance may be linked to incomplete fatty acid b-oxidation and the subsequent increase in acylcarnitine species in different tissues including skeletal muscle. It is not known if acylcarnitines participate in muscle insulin resistance or simply reflect dysregulated metabolism. The aims of this study were to determine whether acylcarnitines can elicit muscle insulin resistance and to better understand the link between incomplete muscle fatty acid β-oxidation, oxidative stress, inflammation, and insulin-resistance development. Differentiated C2C12, primary mouse, and human myotubes were treated with acylcarnitines (C4:0, C14:0, C16:0) or with palmitate with or without carnitine acyltransferase inhibition by mildronate. Treatment with C4:0, C14:0, and C16:0 acylcarnitines resulted in 20-30% decrease in insulin response at the level of Akt phosphorylation and/or glucose uptake. Mildronate reversed palmitate-induced insulin resistance concomitant with an ∼25% decrease in short-chain acylcarnitine and acetylcarnitine secretion. Although proinflammatory cytokines were not affected under these conditions, oxidative stress was increased by 2-3 times by short- or long-chain acylcarnitines. Acylcarnitine-induced oxidative stress and insulin resistance were reversed by treatment with antioxidants. Results are consistent with the conclusion that incomplete muscle fatty acid β-oxidation causes acylcarnitine accumulation and associated oxidative stress, raising the possibility that these metabolites play a role in muscle insulin resistance. © FASEB.

PubMed | Copenhagen University, Massachusetts General Hospital, University of California at Davis, Obesity and Metabolism Research Unit and National Institute of Nutrition And Seafood Research
Type: Journal Article | Journal: The Journal of nutritional biochemistry | Year: 2015

Introduction of vegetable ingredients in fish feed has affected the fatty acid composition in farmed Atlantic salmon (Salmo salar L). Here we investigated how changes in fish feed affected the metabolism of mice fed diets containing fillets from such farmed salmon. We demonstrate that replacement of fish oil with rapeseed oil or soybean oil in fish feed had distinct spillover effects in mice fed western diets containing the salmon. A reduced ratio of n-3/n-6 polyunsaturated fatty acids in the fish feed, reflected in the salmon, and hence also in the mice diets, led to a selectively increased abundance of arachidonic acid in the phospholipid pool in the livers of the mice. This was accompanied by increased levels of hepatic ceramides and arachidonic acid-derived pro-inflammatory mediators and a reduced abundance of oxylipins derived from eicosapentaenoic acid and docosahexaenoic acid. These changes were associated with increased whole body insulin resistance and hepatic steatosis. Our data suggest that an increased ratio between n-6 and n-3-derived oxylipins may underlie the observed marked metabolic differences between mice fed the different types of farmed salmon. These findings underpin the need for carefully considering the type of oil used for feed production in relation to salmon farming.

PubMed | University of Arkansas for Medical Sciences, Obesity and Metabolism Research Unit, University of California at Davis and University of California at Irvine
Type: Journal Article | Journal: American journal of physiology. Renal physiology | Year: 2016

Patients and animals with chronic kidney disease (CKD) exhibit profound alterations in the gut environment including shifts in microbial composition, increased fecal pH, and increased blood levels of gut microbe-derived metabolites (xenometabolites). The fermentable dietary fiber high amylose maize-resistant starch type 2 (HAMRS2) has been shown to alter the gut milieu and in CKD rat models leads to markedly improved kidney function. The aim of the present study was to identify specific cecal bacteria and cecal, blood, and urinary metabolites that associate with changes in kidney function to identify potential mechanisms involved with CKD amelioration in response to dietary resistant starch. Male Sprague-Dawley rats with adenine-induced CKD were fed a semipurified low-fiber diet or a high-fiber diet [59% (wt/wt) HAMRS2] for 3 wk (n = 9 rats/group). The cecal microbiome was characterized, and cecal contents, serum, and urine metabolites were analyzed. HAMRS2-fed rats displayed decreased cecal pH, decreased microbial diversity, and an increased Bacteroidetes-to-Firmicutes ratio. Several uremic retention solutes were altered in the cecal contents, serum, and urine, many of which had strong correlations with specific gut bacteria abundances, i.e., serum and urine indoxyl sulfate were reduced by 36% and 66%, respectively, in HAMRS2-fed rats and urine p-cresol was reduced by 47% in HAMRS2-fed rats. Outcomes from this study were coincident with improvements in kidney function indexes and amelioration of CKD outcomes previously reported for these rats, suggesting an important role for microbial-derived factors and gut microbe metabolism in regulating host kidney function.

PubMed | Sutter Medical Center Sacramento, California Animal Health and Food Safety Laboratory, Obesity and Metabolism Research Unit and University of California at Davis
Type: Journal Article | Journal: PloS one | Year: 2016

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and hospital admission in infants. An analogous disease occurs in cattle and costs US agriculture a billion dollars a year. RSV causes much of its morbidity indirectly via adverse effects of the host response to the virus. RSV is accompanied by elevated prostaglandin E2 (PGE2) which is followed by neutrophil led inflammation in the lung. Ibuprofen is a prototypical non-steroidal anti-inflammatory drug that decreases PGE2 levels by inhibiting cyclooxygenase.We hypothesized that treatment of RSV with ibuprofen would decrease PGE2 levels, modulate the immune response, decrease clinical illness, and decrease the histopathological lung changes in a bovine model of RSV. We further hypothesized that viral replication would be unaffected.We performed a randomized placebo controlled trial of ibuprofen in 16 outbred Holstein calves that we infected with RSV. We measured clinical scores, cyclooxygenase, lipoxygenase and endocannabinoid products in plasma and mediastinal lymph nodes and interleukin (Il)-4, Il-13, Il-17 and interferon- in mediastinal lymph nodes. RSV shedding was measured daily and nasal Il-6, Il-8 and Il-17 every other day. The calves were necropsied on Day 10 post inoculation and histology performed.One calf in the ibuprofen group required euthanasia on Day 8 of infection for respiratory distress. Clinical scores (p<0.01) and weight gain (p = 0.08) seemed better in the ibuprofen group. Ibuprofen decreased cyclooxygenase, lipoxygenase, and cytochrome P450 products, and increased monoacylglycerols in lung lymph nodes. Ibuprofen modulated the immune response as measured by narrowed range of observed Il-13, Il-17 and IFN- gene expression in mediastinal lymph nodes. Lung histology was not different between groups, and viral shedding was increased in calves randomized to ibuprofen.Ibuprofen decreased PGE2, modulated the immune response, and improved clinical outcomes. However lung histopathology was not affected and viral shedding was increased.

Duran A.T.,California State University, Fullerton | Gertz E.,Obesity and Metabolism Research Unit | Judelson D.A.,California State University, Fullerton | Haqq A.M.,University of Alberta | And 3 more authors.
Pediatric Exercise Science | Year: 2015

Prader-Willi Syndrome (PWS), the best characterized form of syndromic obesity, presents with abnormally high fat mass. In children, obesity presents with low-grade systemic inflammation. This study evaluated if PWS and/or nonsyndromic obesity affected cytokine responses to intermittent aerobic exercise in children. Eleven children with PWS (11 ± 2 y, 45.4 ± 9.5% body fat), 12 children with obesity (OB) (9 ± 1 y, 39.9 ± 6.8% body fat), and 12 lean (LN) children (9 ± 1 y, 17.5 ± 4.6% body fat) participated. Children completed 10 2-min cycling bouts of vigorous intensity, separated by 1-min rest. Blood samples were collected preexercise (PRE), immediately postexercise (IP), and 15, 30, and 60 min into recovery to analyze possible changes in cytokines. In all groups, IL-6 and IL-8 concentrations were greater during recovery compared with PRE. PWS and OB exhibited higher IL-6 area under the curve (AUC) than LN (p < .01 for both). PWS demonstrated higher IL-8 AUC than LN (p < .04). IL-10, TNF-α, and IFN-γ did not change with exercise (p > .05 for all). Results indicate that children with PWS respond with increased Il-6 and IL-8 concentrations to acute exercise similarly to controls. Excess adiposity and epigenetic modifications may explain the greater integrated IL-6 and IL-8 responses in PWS compared with controls. © 2015 Human Kinetics, Inc.

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