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Shibao C, Peche VS, Williams IM, Samovski D, Pietka TA, Abumrad NN, Gamazon E, Goldberg IJ, Wasserman D, Abumrad NA. Microvascular insulin resistance associates with enhanced muscle glucose disposal in CD36 deficiency. medRxiv 2024:2024.02.16.24302950. [PMID: 38405702 PMCID: PMC10889024 DOI: 10.1101/2024.02.16.24302950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Dysfunction of endothelial insulin delivery to muscle associates with insulin resistance. CD36, a fatty acid transporter and modulator of insulin signaling is abundant in endothelial cells, especially in capillaries. Humans with inherited 50% reduction in CD36 expression have endothelial dysfunction but whether it is associated with insulin resistance is unclear. Using hyperinsulinemic/euglycemic clamps in Cd36-/- and wildtype mice, and in 50% CD36 deficient humans and matched controls we found that Cd36-/- mice have enhanced systemic glucose disposal despite unaltered transendothelial insulin transfer and reductions in microvascular perfusion and blood vessel compliance. Partially CD36 deficient humans also have better glucose disposal than controls with no capillary recruitment by insulin. CD36 knockdown in primary human-derived microvascular cells impairs insulin action on AKT, endothelial nitric oxide synthase, and nitric oxide release. Thus, insulin resistance of microvascular function in CD36 deficiency paradoxically associates with increased glucose utilization, likely through a remodeling of muscle gene expression.
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Affiliation(s)
- Cyndya Shibao
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville TN
| | - Vivek S. Peche
- Department of Medicine, Division of Nutritional Sciences and Obesity Research, Washington University School of Medicine, St. Louis, MO
| | - Ian M. Williams
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville TN
| | - Dmitri Samovski
- Department of Medicine, Division of Nutritional Sciences and Obesity Research, Washington University School of Medicine, St. Louis, MO
| | - Terri A. Pietka
- Department of Medicine, Division of Nutritional Sciences and Obesity Research, Washington University School of Medicine, St. Louis, MO
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville TN
| | - Eric Gamazon
- Department of Medicine, Division of Genetic Medicine, Vanderbilt University, Nashville, TN
| | - Ira J. Goldberg
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, New York University Grossman School of Medicine, New York, NY
| | - David Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville TN
| | - Nada A. Abumrad
- Department of Medicine, Division of Nutritional Sciences and Obesity Research, Washington University School of Medicine, St. Louis, MO
- Department of Cell Biology & Physiology, Washington University School of Medicine, St. Louis, MO
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2
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Ertuglu LA, Deger SM, Alsouqi A, Hung A, Gamboa J, Mambungu C, Sha F, Siew E, Abumrad NN, Ikizler TA. A randomized controlled pilot trial of anakinra and pioglitazone for protein metabolism in patients on maintenance haemodialysis. J Cachexia Sarcopenia Muscle 2024; 15:401-411. [PMID: 38178557 PMCID: PMC10834322 DOI: 10.1002/jcsm.13395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/17/2023] [Accepted: 11/02/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Chronic inflammation and insulin resistance are highly prevalent in patients on maintenance haemodialysis (MHD) and are strongly associated with protein energy wasting. We conducted a pilot, randomized, placebo-controlled trial of recombinant human interleukin-1 receptor antagonist (IL-1ra) and pioglitazone to explore the safety, feasibility and efficacy for insulin-mediated protein metabolism in patients undergoing MHD. METHODS Twenty-four patients were randomized to receive IL-1ra, pioglitazone or placebo for 12 weeks. Changes in serum inflammatory markers and insulin-mediated protein synthesis, breakdown and net balance in the whole-body and skeletal muscle compartments were assessed using hyperinsulinaemic-hyperaminoacidemic clamp technique at baseline and Week 12. RESULTS Among 24 patients, median (interquartile range) age was 51 (40, 61), 79% were African American and 21% had diabetes mellitus. All patients initiated on intervention completed the study, and no serious adverse events were observed. There was a statistically significant decrease in serum high-sensitivity C-reactive protein in the pioglitazone group compared with placebo, but not in the IL-1ra group. No significant differences in the changes of whole-body or skeletal muscle protein synthesis, breakdown and net balance were found between the groups. CONCLUSIONS In this pilot study, there were no statistically significant effects of 12 weeks of IL-1ra or pioglitazone on protein metabolism in patients on MHD. CLINICALTRIALS gov registration: NCT02278562.
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Affiliation(s)
- Lale A Ertuglu
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Serpil Muge Deger
- Department of Nephrology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Aseel Alsouqi
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
- Now with Department of Medicine, Division of Hematology and Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Adriana Hung
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, USA
- Veterans Administration Tennessee Valley Healthcare System, Nashville, TN, USA
| | - Jorge Gamboa
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Cindy Mambungu
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Feng Sha
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Edward Siew
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, USA
- Veterans Administration Tennessee Valley Healthcare System, Nashville, TN, USA
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - T Alp Ikizler
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, USA
- Veterans Administration Tennessee Valley Healthcare System, Nashville, TN, USA
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Sundaresan S, Johnson C, Dixon KB, Dole M, Kilkelly D, Antoun J, Flynn CR, Abumrad NN, Tamboli R. Intraduodenal nutrient infusion differentially alters intestinal nutrient sensing, appetite, and satiety responses in lean and obese subjects. Am J Clin Nutr 2023; 118:646-656. [PMID: 37661107 PMCID: PMC10517208 DOI: 10.1016/j.ajcnut.2023.06.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 06/02/2023] [Accepted: 06/12/2023] [Indexed: 09/05/2023] Open
Abstract
BACKGROUND Intestinal nutrient sensing regulates food intake and energy metabolism by acting locally and relaying nutritional status to the brain. It is unclear whether these mechanisms are altered in obese humans. OBJECTIVES We aimed to investigate differences in duodenal nutrient sensing in humans with or without obesity and the effects of transiently blocking vagal transmission on nutrient sensing, hunger, and appetite. METHODS In a single-blinded, randomized, cross-over design, subjects with or without obesity (n = 14 and n = 11, respectively) were infused intraduodenally with saline or a combination of glucose and oleic acid for 90 min (glucose load: 22.5 g, 1 kcal/min; oleic acid load: 10 g, 1 kcal/min) in the presence or absence of local anesthetic (benzocaine). Blood was sampled at 10-min intervals (120-240 min) and 15-min intervals until termination of the study for measurements of gut hormones, insulin, leptin, and C-peptide. Hunger and satiety sensations were scored using the visual analog scale, and hepatic glucose production and glucose oxidation rates were measured. RESULTS Duodenal nutrient infusion in lean subjects led to a 65% drop in acyl ghrelin release and robustly increased cholecystokinin 8 (CCK-8) release (65%; P = 0.023); benzocaine infusion delayed this response (2-factor repeated-measures analysis of variance, P = 0.0065). In contrast, subjects with obesity had significantly blunted response to nutrient infusion, and no further effects were observed with benzocaine. Additionally, significant delays were observed in peptide YY (3-36), pancreatic polypeptide, glucose inhibitory peptide, and glucagon-like peptide 1 (7-36) response. No significant interactions were found between body mass index (BMI) or baseline hormone levels and areas under the curve for hormones except CCK-8 (BMI, P = 0.018; baseline CCK, P = 0.013). Nutrient-induced hunger and satiety sensations were impeded by benzocaine only in the lean cohort. Hunger and satiety sensations in subjects with obesity were not responsive to nutrient entry into the duodenum, and no additional effects were observed by blocking neural signaling. CONCLUSION Nutrient-induced gut hormone release and response to transient vagal blockade are significantly blunted in subjects with obesity. This trial was registered at clinicaltrials.org as NCT02537314.
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Affiliation(s)
- Sinju Sundaresan
- Department of Physiology, Midwestern University, Downers Grove, IL; Department of Surgery, Vanderbilt University Medical Center, Nashville, TN.
| | - Connor Johnson
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Kala B Dixon
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Michael Dole
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Donna Kilkelly
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Joseph Antoun
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Charles Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Robyn Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
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4
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Rathmacher JA, Fuller JC, Abumrad NN, Flynn CR. Inflammation Biomarker Response to Oral 2-Hydroxybenzylamine (2-HOBA) Acetate in Healthy Humans. Inflammation 2023; 46:1343-1352. [PMID: 36935449 PMCID: PMC10025056 DOI: 10.1007/s10753-023-01801-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/28/2023] [Accepted: 03/02/2023] [Indexed: 03/21/2023]
Abstract
Inflammation is associated with the formation of reactive oxygen species (ROS) and the formation of lipid-derived compounds, such as isolevuglandins (IsoLGs), malondialdehyde, 4-hydroxy-nonenal, and 4-oxo-nonenal. The most reactive of these are the IsoLGs, which form covalent adducts with lysine residues and other cellular primary amines leading to changes in protein function, immunogenicity, and epigenetic alterations and have been shown to contribute to a number of inflammatory diseases. 2-Hydroxybenzylamine (2-HOBA) is a natural compound found in buckwheat seeds and reacts with all IsoLG adducts preventing adduct formation with proteins and DNA. Therefore, 2-HOBA is well positioned as an agent for the prevention of inflammatory-prone diseases. In this study, we examined the potential beneficial effects of 2-HOBA on oxidative stress and inflammatory biomarkers in two cohorts of healthy younger and older adults. We utilized the Olink® targeted inflammation panel before and after an oral 15-day treatment regimen with 2-HOBA. We found significant relative changes in the plasma concentration of 15 immune proteins that may reflect the in vivo immune targets of 2-HOBA. Treatment of 2-HOBA resulted in significant increased levels of CCL19, IL-12β, IL-20Rα, and TNFβ, whereas levels of TWEAK significantly decreased. Ingenuity Pathway Analysis identified canonical pathways regulated by the differentially secreted cytokines, chemokines, and growth factors upon 2-HOBA treatment and further points to biofunctions related to the recruitment, attraction, and movement of different immune cell types. In conclusion, 2-HOBA significantly altered the protein biomarkers CCL19, IL-12β, IL-20Rα, TNFβ, and TWEAK, and these may be responsible for the protective effects of 2-HOBA against reactive electrophiles, such as IsoLGs, commonly expressed in conditions of excessive oxidative stress. 2-HOBA has a role as a IsoLG scavenger to proactively improve immune health in a variety of conditions.
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Affiliation(s)
- John A Rathmacher
- MTI BioTech, Inc, Iowa State University Research Park, Ames, IA, USA
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | | | - Naji N Abumrad
- MTI BioTech, Inc, Iowa State University Research Park, Ames, IA, USA
- Metabolic Technologies, LLC, Missoula, MT, USA
- Department of Surgery, Vanderbilt University Medical Center, MRBIV Room 8465A, Nashville, TN, 37232, USA
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, MRBIV Room 8465A, Nashville, TN, 37232, USA.
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5
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Flynn CR, Tamboli RA, Antoun J, Sidani RM, Williams B, Spann MD, English WJ, Welch EB, Sundaresan S, Abumrad NN. Caloric Restriction and Weight Loss Are Primary Factors in the Early Tissue-Specific Metabolic Changes After Bariatric Surgery. Diabetes Care 2022; 45:1914-1916. [PMID: 35724307 PMCID: PMC9346980 DOI: 10.2337/dc22-0069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/03/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate changes in insulin sensitivity, hormone secretion, and hepatic steatosis immediately after caloric restriction, vertical sleeve gastrectomy (VSG), and Roux-en-Y gastric bypass (RYGB). RESEARCH DESIGN AND METHODS Obese subjects were assessed for 1) insulin sensitivity with hyperinsulinemic-euglycemic clamp with glucose tracer infusion, 2) adipokine concentrations with serum and subcutaneous adipose interstitial fluid sampling, and 3) hepatic fat content with MRI before and 7-10 days after VSG, RYGB, or supervised caloric restriction. RESULTS Each group exhibited an ∼5% total body weight loss, accompanied by similar improvements in hepatic glucose production and hepatic, skeletal muscle, and adipose tissue insulin sensitivity. Leptin concentrations in plasma and adipose interstitial fluid were equally decreased, and reductions in hepatic fat were similar. CONCLUSIONS The improvements in insulin sensitivity and adipokine secretion observed early after bariatric surgery are replicated by equivalent caloric restriction and weight loss.
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Affiliation(s)
- Charles Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Robyn A Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Joseph Antoun
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Reem M Sidani
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Brandon Williams
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Matthew D Spann
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Wayne J English
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - E Brian Welch
- Department of Radiology and Radiologic Sciences, Vanderbilt University Medical Center, Nashville, TN
| | - Sinju Sundaresan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
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6
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Banan B, Wei Y, Simo O, Tso P, Abumrad NN, Flynn CR, Sundaresan S, Albaugh VL. Intestinal Lymph Collection via Cannulation of the Mesenteric Lymphatic Duct in Mice. J Surg Res 2020; 260:399-408. [PMID: 33261855 DOI: 10.1016/j.jss.2020.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 10/22/2020] [Accepted: 11/01/2020] [Indexed: 10/22/2022]
Abstract
BACKGROUND We have optimized a technique for cannulation of mesenteric lymph duct (MLD) in mice. Mice have low rates of intestinal lymph production; the MLDs are smaller and associated with fragile vasculature. Previous protocols for lymph collection based on the open lymph fistula model were associated with low success rates in mice. Bariatric surgery procedures worsen success rates due to postoperative adhesions and GI rearrangement. We have used this procedure to collect mesenteric lymph from mice undergoing bile diversion from gall bladder to ileum (GB-IL). HYPOTHESIS We hypothesize that peptide YY (PYY) levels in mesenteric lymph will increase following nutrient delivery in mice undergoing bile diversion from gall bladder to ileum (GB-IL). METHODS AND RESULTS We observe that cannulation of the MLD using a needled-catheter maintains lymph vessel integrity, prevents excessive lymph leakage, and is less traumatic, leading to high success rates (>95%). PYY levels in mesenteric lymph after GB-IL were significantly higher post nutrient infusion. The procedure takes approximately 20 min; small rodent surgical experience and practice are required for success. CONCLUSIONS Intestinal lymph can be collected from mice, including those undergoing bariatric surgical procedures with high success rates by cannulation of the mesenteric lymph duct.
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Affiliation(s)
- Babak Banan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Yan Wei
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; Beijing Shijitan Hospital, Capital Medical University, China
| | - Ornella Simo
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Patrick Tso
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Charles Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Sinju Sundaresan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Physiology, Midwestern University, Chicago, Illinois.
| | - Vance L Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
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7
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Pitchford LM, Driver PM, Fuller JC, Akers WS, Abumrad NN, Amarnath V, Milne GL, Chen SC, Ye F, Roberts LJ, Shoemaker MB, Oates JA, Rathmacher JA, Boutaud O. Safety, tolerability, and pharmacokinetics of repeated oral doses of 2-hydroxybenzylamine acetate in healthy volunteers: a double-blind, randomized, placebo-controlled clinical trial. BMC Pharmacol Toxicol 2020; 21:3. [PMID: 31907026 PMCID: PMC6945443 DOI: 10.1186/s40360-020-0382-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/31/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND 2-Hydroxybenzylamine (2-HOBA) is a selective dicarbonyl electrophile scavenger being developed as a nutritional supplement to help protect against the development of conditions associated with dicarbonyl electrophile formation, such as the cognitive decline observed with Mild Cognitive Impairment or Alzheimer's disease. METHODS This study evaluated the safety, tolerability, and pharmacokinetics of repeated oral doses of 2-HOBA acetate (500 or 750 mg) administered to healthy volunteers every eight hours for two weeks. The effects of 2-HOBA on cyclooxygenase function and cerebrospinal fluid penetrance of 2-HOBA were also investigated. RESULTS Repeated oral administration of 2-HOBA was found to be safe and well-tolerated up to 750 mg TID for 15 days. 2-HOBA was absorbed within 2 h of administration, had a half-life of 2.10-3.27 h, and an accumulation ratio of 1.38-1.52. 2-HOBA did not interfere with cyclooxygenase function and was found to be present in cerebrospinal fluid 90 min after dosing. CONCLUSIONS Repeated oral administration of 2-HOBA was found to be safe and well-tolerated. These results support continued development of 2-HOBA as a nutritional supplement. TRIAL REGISTRATION Studies are registered at ClinicalTrials.gov (NCT03555682 Registered 13 June 2018, NCT03554096 Registered 12 June 18).
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Affiliation(s)
- Lisa M. Pitchford
- MTI BioTech, Inc., Ames, IA 50010 USA
- Department of Kinesiology, Iowa State University, Ames, IA 50010 USA
| | - Patricia M. Driver
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | | | - Wendell S. Akers
- Department of Pharmaceutical Sciences, Lipscomb University College of Pharmacy, Nashville, TN 37204 USA
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Venkataraman Amarnath
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Ginger L. Milne
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Sheau-Chiann Chen
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Fei Ye
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - L. Jackson Roberts
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - M. Benjamin Shoemaker
- Department of Medicine, Division of Cardiology, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - John A. Oates
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232 USA
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - John A. Rathmacher
- MTI BioTech, Inc., Ames, IA 50010 USA
- Department of Animal Science, Iowa State University, Ames, IA 50010 USA
| | - Olivier Boutaud
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
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Shibao CA, Abumrad NA, Abumrad NN, Parsa D, Celedonio JE, Scudder SK, Breier NC. Abstract P3011: Role of CD36 in Insulin Mediated Microvascular Vasodilation in African Americans. Hypertension 2019. [DOI: 10.1161/hyp.74.suppl_1.p3011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
CD36 is a membrane protein involved in fatty acids uptake that is expressed in the endothelium, which has been associated with endothelial dysfunction in African Americans (AA). One in four AA is G-allele carriers for coding CD36 SNP rs3211938, which results in ~50% reduction in its expression. We reported that potentiating nitric oxide action (NO) with sildenafil restored endothelial dysfunction in conduit arteries in G-allele carriers. In this study, we tested the hypothesis that in G-allele carriers, sildenafil would improve insulin-induced microvascular recruitment (MBV) in response to fat infusion. We recruited 25 healthy AA (17 non-carriers [ages 34 ± 7.4] and eight G-allele carriers [42 ± 7.4 yrs]). Subjects underwent three visits: Visit 1: Saline infusion and hyperinsulinemic euglycemic clamp (HIE clamp). Visit 2: Lipid infusion and HIE clamp and Visit 3: Lipid infusion and HIE clamp after a four-week sildenafil treatment (60 mg/day). During each visit, the subjects underwent an assessment of MBV at baseline (bsl), after 3-hour insulin (Ins) infusion (40mu/m
2
/min) and after Ins and L-arginine (10mg/kg/min) for 30 min. infusion (Ins+L-arg). Ins+L-arg (saline day) increased the % change in MBV in both groups. However, this increase was less in carriers as compared to non-carriers (13.6±42.4 and 38.9±74.4),
Fig. A.
Intralipid (IL) infusion increased MBV but only in non-carriers,
Fig. B
. Treatment with sildenafil in the presence of IL infusion induced a decline in MBV in G-allele carriers
Fig. C
. In conclusion, healthy AAs with CD36 deficiency had a poor insulin-induced microvascular recruitment and appeared to be worsened by potentiating NO function with sildenafil.
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Affiliation(s)
| | | | | | - Dena Parsa
- Vanderbilt Univ. Med Cntr, Nashville, TN
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9
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Gregory JM, Smith TJ, Slaughter JC, Mason HR, Hughey CC, Smith MS, Kandasamy B, Greeley SAW, Philipson LH, Naylor RN, Letourneau LR, Abumrad NN, Cherrington AD, Moore DJ. Iatrogenic Hyperinsulinemia, Not Hyperglycemia, Drives Insulin Resistance in Type 1 Diabetes as Revealed by Comparison With GCK-MODY (MODY2). Diabetes 2019; 68:1565-1576. [PMID: 31092478 PMCID: PMC6692813 DOI: 10.2337/db19-0324] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/07/2019] [Indexed: 12/11/2022]
Abstract
Although insulin resistance consistently occurs with type 1 diabetes, its predominant driver is uncertain. We therefore determined the relative contributions of hyperglycemia and iatrogenic hyperinsulinemia to insulin resistance using hyperinsulinemic-euglycemic clamps in three participant groups (n = 10/group) with differing insulinemia and glycemia: healthy control subjects (euinsulinemia and euglycemia), glucokinase-maturity-onset diabetes of the young (GCK-MODY; euinsulinemia and hyperglycemia), and type 1 diabetes (hyperinsulinemia and hyperglycemia matching GCK-MODY). We assessed the contribution of hyperglycemia by comparing insulin sensitivity in control and GCK-MODY and the contribution of hyperinsulinemia by comparing GCK-MODY and type 1 diabetes. Hemoglobin A1c was normal in control subjects and similarly elevated for type 1 diabetes and GCK-MODY. Basal insulin levels in control subjects and GCK-MODY were nearly equal but were 2.5-fold higher in type 1 diabetes. Low-dose insulin infusion suppressed endogenous glucose production similarly in all groups and suppressed nonesterified fatty acids similarly between control subjects and GCK-MODY, but to a lesser extent for type 1 diabetes. High-dose insulin infusion stimulated glucose disposal similarly in control subjects and GCK-MODY but was 29% and 22% less effective in type 1 diabetes, respectively. Multivariable linear regression showed that insulinemia-but not glycemia-was significantly associated with muscle insulin sensitivity. These data suggest that iatrogenic hyperinsulinemia predominates in driving insulin resistance in type 1 diabetes.
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Affiliation(s)
- Justin M Gregory
- Ian Burr Division of Pediatric Endocrinology and Diabetes, Vanderbilt University School of Medicine, Nashville, TN
| | - T Jordan Smith
- Ian Burr Division of Pediatric Endocrinology and Diabetes, Vanderbilt University School of Medicine, Nashville, TN
| | - James C Slaughter
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN
| | - Holly R Mason
- Diet, Body Composition, and Human Metabolism Core, Vanderbilt University, Nashville, TN
| | - Curtis C Hughey
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Marta S Smith
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Balamurugan Kandasamy
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism and the Kovler Diabetes Center, The University of Chicago, Chicago, IL
| | - Siri Atma W Greeley
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism and the Kovler Diabetes Center, The University of Chicago, Chicago, IL
| | - Louis H Philipson
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism and the Kovler Diabetes Center, The University of Chicago, Chicago, IL
| | - Rochelle N Naylor
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism and the Kovler Diabetes Center, The University of Chicago, Chicago, IL
| | - Lisa R Letourneau
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism and the Kovler Diabetes Center, The University of Chicago, Chicago, IL
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN
| | - Alan D Cherrington
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Daniel J Moore
- Ian Burr Division of Pediatric Endocrinology and Diabetes, Vanderbilt University School of Medicine, Nashville, TN
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Engelhardt BG, Savani U, Jung DK, Powers AC, Jagasia M, Chen H, Winnick JJ, Tamboli RA, Crowe JE, Abumrad NN. New-Onset Post-Transplant Diabetes Mellitus after Allogeneic Hematopoietic Cell Transplant Is Initiated by Insulin Resistance, Not Immunosuppressive Medications. Biol Blood Marrow Transplant 2019; 25:1225-1231. [PMID: 30738170 PMCID: PMC6559863 DOI: 10.1016/j.bbmt.2019.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 02/01/2019] [Indexed: 12/12/2022]
Abstract
New-onset post-transplant diabetes mellitus (PTDM) occurs frequently after allogeneic hematopoietic cell transplant (HCT). Although calcineurin inhibitors and corticosteroids are assumed to be the cause for hyperglycemia, patients developing PTDM have elevated fasting C-peptide levels before HCT and before immunosuppressive medications. To determine if PTDM results from established insulin resistance present before transplant, we performed oral glucose tolerance tests (OGTTs) and measured whole body, peripheral, and hepatic insulin sensitivity with euglycemic hyperinsulinemic clamps before and 90 days after HLA-identical sibling donor HCT in 20 patients without pretransplant diabetes. HCT recipients were prospectively followed for the development of new-onset PTDM defined as a weekly fasting blood glucose ≥ 126 mg/dL or random blood glucose ≥ 200 mg/dL. During the first 100 days all patients received calcineurin inhibitors, and 11 individuals (55%) were prospectively diagnosed with new-onset PTDM. PTDM diagnosis preceded corticosteroid treatment. During the pretransplant OGTT, elevated fasting (87 mg/dL versus 101 mg/dL; P = .005) but not 2-hour postprandial glucose levels predicted PTDM diagnosis (P = .648). In response to insulin infusion during the euglycemic hyperinsulinemic clamp, patients developing PTDM had lower whole body glucose utilization (P = .047) and decreased peripheral/skeletal muscle uptake (P = .031) before and after transplant, respectively, when compared with non-PTDM patients. Hepatic insulin sensitivity did not differ. Survival was decreased in PTDM patients (2-year estimate, 55% versus 100%; P = .039). Insulin resistance before HCT is a risk factor for PTDM independent of immunosuppression. Fasting pretransplant glucose levels identified PTDM susceptibility, and peripheral insulin resistance could be targeted for prevention and treatment of PTDM after HCT.
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Affiliation(s)
- Brian G Engelhardt
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
| | - Ujjawal Savani
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dae Kwang Jung
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Alvin C Powers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, VA Tennessee Valley Healthcare, Nashville, Tennessee
| | - Madan Jagasia
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Heidi Chen
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jason J Winnick
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Robyn A Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - James E Crowe
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
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11
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Flynn CR, Albaugh VL, Abumrad NN. Metabolic Effects of Bile Acids: Potential Role in Bariatric Surgery. Cell Mol Gastroenterol Hepatol 2019; 8:235-246. [PMID: 31075353 PMCID: PMC6664228 DOI: 10.1016/j.jcmgh.2019.04.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 02/08/2023]
Abstract
Bariatric surgery is the most effective and durable treatment for morbid obesity, with an unexplained yet beneficial side effect of restoring insulin sensitivity and improving glycemia, often before weight loss is observed. Among the many contributing mechanisms often cited, the altered handling of intestinal bile acids is of considerable therapeutic interest. Here, we review a growing body of literature examining the metabolic effects of bile acids ranging from their physical roles in dietary fat handling within the intestine to their functions as endocrine and paracrine hormones in potentiating responses to bariatric surgery. The roles of 2 important bile acid receptors, Takeda G-protein coupled receptor (also known as G-protein coupled bile acid receptor) and farnesoid X receptor, are highlighted as is downstream signaling through glucagon-like polypeptide 1 and its cognate receptor. Additional improvements in other phenotypes and potential contributions of commensal gut bacteria, such as Akkermansia muciniphila, which are manifest after Roux-en-Y gastric bypass and other emulations, such as gallbladder bile diversion to the ileum, are also discussed.
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Affiliation(s)
- Charles R. Flynn
- Correspondence Address correspondence to: Charles R. Flynn, PhD, 1161 21st Avenue S, CCC-2308 MCN, Nashville, Tennessee 37232-2730. fax: (615) 343-6456.
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12
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Dunn JP, Abumrad NN, Patterson BW, Kessler RM, Tamboli RA. Brief communication: β-cell function influences dopamine receptor availability. PLoS One 2019; 14:e0212738. [PMID: 30849082 PMCID: PMC6407783 DOI: 10.1371/journal.pone.0212738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 02/10/2019] [Indexed: 11/19/2022] Open
Abstract
We aim to identify physiologic regulators of dopamine (DA) signaling in obesity but previously did not find a compelling relationship with insulin sensitivity measured by oral-minimal model (OMM) and DA subtype 2 and 3 receptor (D2/3R) binding potential (BPND). Reduced disposition index (DI), a β-cell function metric that can also be calculated by OMM, was shown to predict a negative reward behavior that occurs in states of lower endogenous DA. We hypothesized that reduced DI would occur with higher D2/3R BPND, reflecting lower endogenous DA. Participants completed PET scanning, with a displaceable radioligand to measure D2/3R BPND, and a 5-hour oral glucose tolerance test to measure DI by OMM. We studied 26 age-similar females without (n = 8) and with obesity (n = 18) (22 vs 39 kg/m2). Reduced DI predicted increased striatal D2/3R BPND independent of BMI. By accounting for β-cell function, we were able to determine that the state of insulin and glucose metabolism is pertinent to striatal D2/3R BPND in obesity. Clinical Trial Registration Number: NCT00802204.
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Affiliation(s)
- Julia P. Dunn
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Veterans Administration St. Louis Health Care System, St. Louis, Missouri, United States of America
- * E-mail:
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Bruce W. Patterson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Robert M. Kessler
- Department of Radiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Robyn A. Tamboli
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
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13
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Albaugh VL, Banan B, Antoun J, Xiong Y, Guo Y, Ping J, Alikhan M, Clements BA, Abumrad NN, Flynn CR. Role of Bile Acids and GLP-1 in Mediating the Metabolic Improvements of Bariatric Surgery. Gastroenterology 2019; 156:1041-1051.e4. [PMID: 30445014 PMCID: PMC6409186 DOI: 10.1053/j.gastro.2018.11.017] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/19/2018] [Accepted: 11/01/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS Bile diversion to the ileum (GB-IL) has strikingly similar metabolic and satiating effects to Roux-en-Y gastric bypass (RYGB) in rodent obesity models. The metabolic benefits of these procedures are thought to be mediated by increased bile acids, although parallel changes in body weight and other confounding variables limit this interpretation. METHODS Global G protein-coupled bile acid receptor-1 null (Tgr5-/-) and intestinal-specific farnesoid X receptor null (FxrΔ/E) mice on high-fat diet as well as wild-type C57BL/6 and glucagon-like polypeptide 1 receptor deficient (Glp-1r-/-) mice on chow diet were characterized following GB-IL. RESULTS GB-IL induced weight loss and improved oral glucose tolerance in Tgr5-/-, but not FxrΔ/E mice fed a high-fat diet, suggesting a role for intestinal Fxr. GB-IL in wild-type, chow-fed mice prompted weight-independent improvements in glycemia and glucose tolerance secondary to augmented insulin responsiveness. Improvements were concomitant with increased levels of lymphatic GLP-1 in the fasted state and increased levels of intestinal Akkermansia muciniphila. Improvements in fasting glycemia after GB-IL were mitigated with exendin-9, a GLP-1 receptor antagonist, or cholestyramine, a bile acid sequestrant. The glucoregulatory effects of GB-IL were lost in whole-body Glp-1r-/- mice. CONCLUSIONS Bile diversion to the ileum improves glucose homeostasis via an intestinal Fxr-Glp-1 axis. Altered intestinal bile acid availability, independent of weight loss, and intestinal Akkermansia muciniphila appear to mediate the metabolic changes observed after bariatric surgery and might be manipulated for treatment of obesity and diabetes.
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Affiliation(s)
- Vance L. Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Babak Banan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Joseph Antoun
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Yanhua Xiong
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Yan Guo
- Department of Cancer Biology, Vanderbilt University, Nashville, TN
| | - Jie Ping
- Department of Cancer Biology, Vanderbilt University, Nashville, TN
| | - Muhammed Alikhan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | | | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
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14
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Savani UB, Jung DK, Crowe JE, Abumrad NN, Powers AC, Jagasia M, Cornell RF, Goodman S, Kassim AA, Culos KAA, Gatwood KS, Byrne MT, Engelhardt BG. New-Onset Post-Transplant Diabetes Mellitus after Allogeneic Hematopoietic Celltransplant Is Initiated By Insulin Resistance, Not Iatrogenesis. Biol Blood Marrow Transplant 2019. [DOI: 10.1016/j.bbmt.2018.12.443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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15
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Pitchford LM, Rathmacher JA, Fuller JC, Daniels JS, Morrison RD, Akers WS, Abumrad NN, Amarnath V, Currey PM, Roberts LJ, Oates JA, Boutaud O. First-in-human study assessing safety, tolerability, and pharmacokinetics of 2-hydroxybenzylamine acetate, a selective dicarbonyl electrophile scavenger, in healthy volunteers. BMC Pharmacol Toxicol 2019; 20:1. [PMID: 30611293 PMCID: PMC6321651 DOI: 10.1186/s40360-018-0281-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 12/20/2018] [Indexed: 02/01/2023] Open
Abstract
Background 2-Hydroxybenzylamine (2-HOBA) is a selective scavenger of dicarbonyl electrophiles that protects proteins and lipids from being modified by these electrophiles. It is currently being developed for use as a nutritional supplement to help maintain good health and protect against the development of conditions associated with dicarbonyl electrophile formation, such as the cognitive decline associated with Mild Cognitive Impairment and Alzheimer’s disease. Methods In this first-in-human study, the safety, tolerability, and pharmacokinetics of six ascending single oral doses of 2-HOBA acetate were tested in eighteen healthy human volunteers. Results Reported adverse events were mild and considered unlikely to be related to 2-HOBA. There were no clinically significant changes in vital signs, ECG recordings, or clinical laboratory parameters. 2-HOBA was fairly rapidly absorbed, with a tmax of 1–2 h, and eliminated, with a t1/2 of approximately 2 h. Both tmax and t1/2 were independent of dose level, while Cmax and AUC increased proportionally with dose level. Conclusions 2-HOBA acetate was safe and well-tolerated at doses up to 825 mg in healthy human volunteers, positioning it as a good candidate for continued development as a nutritional supplement. Trial registration This study is registered at ClinicalTrials.gov (NCT03176940). Electronic supplementary material The online version of this article (10.1186/s40360-018-0281-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - John A Rathmacher
- Metabolic Technologies, Inc., Ames, IA, 50010, USA.,Department of Animal Science, Iowa State University, Ames, IA, 50010, USA
| | | | | | | | - Wendall S Akers
- Department of Pharmaceutical Sciences, Lipscomb University College of Pharmacy, Nashville, TN, 37204, USA.,Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Venkataraman Amarnath
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Patricia M Currey
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - L Jackson Roberts
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.,Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - John A Oates
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.,Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Olivier Boutaud
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
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16
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Deger SM, Hewlett JR, Gamboa J, Ellis CD, Hung AM, Siew ED, Mamnungu C, Sha F, Bian A, Stewart TG, Abumrad NN, Ikizler TA. Insulin resistance is a significant determinant of sarcopenia in advanced kidney disease. Am J Physiol Endocrinol Metab 2018; 315:E1108-E1120. [PMID: 29894202 PMCID: PMC6336962 DOI: 10.1152/ajpendo.00070.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Maintenance hemodialysis (MHD) patients display significant nutritional abnormalities. Insulin is an anabolic hormone with direct effects on skeletal muscle (SM). We examined the anabolic actions of insulin, whole-body (WB), and SM protein turnover in 33 MHD patients and 17 participants without kidney disease using hyperinsulinemic-euglycemic-euaminoacidemic (dual) clamp. Gluteal muscle biopsies were obtained before and after the dual clamp. At baseline, WB protein synthesis and breakdown rates were similar in MHD patients. During dual clamp, controls had a higher increase in WB protein synthesis and a higher suppression of WB protein breakdown compared with MHD patients, resulting in statistically significantly more positive WB protein net balance [2.02 (interquartile range [IQR]: 1.79 and 2.36) vs. 1.68 (IQR: 1.46 and 1.91) mg·kg fat-free mass-1·min-1 for controls vs. for MHD patients, respectively, P < 0.001]. At baseline, SM protein synthesis and breakdown rates were higher in MHD patients versus controls, but SM net protein balance was similar between groups. During dual clamp, SM protein synthesis increased statistically significantly more in controls compared with MHD patients ( P = 0.03), whereas SM protein breakdown decreased comparably between groups. SM net protein balance was statistically significantly more positive in controls compared with MHD patients [67.3 (IQR: 46.4 and 97.1) vs. 15.4 (IQR: -83.7 and 64.7) μg·100 ml-1·min-1 for controls and MHD patients, respectively, P = 0.03]. Human SM biopsy showed a positive correlation between glucose and leucine disposal rates, phosphorylated AKT to AKT ratio, and muscle mitochondrial markers in controls but not in MHD patients. Diminished response to anabolic actions of insulin in the stimulated setting could lead to muscle wasting in MHD patients.
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Affiliation(s)
- Serpil M. Deger
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jennifer R. Hewlett
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
- 2Florida Atlantic University, Charles E. Schmidt College of Medicine, Boca Raton, Florida
| | - Jorge Gamboa
- 3Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Charles D. Ellis
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
- 4Vanderbilt Center for Kidney Diseases, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Adriana M. Hung
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
- 5Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Edward D. Siew
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
- 4Vanderbilt Center for Kidney Diseases, Vanderbilt University Medical Center, Nashville, Tennessee
- 5Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Cindy Mamnungu
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Feng Sha
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
- 4Vanderbilt Center for Kidney Diseases, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Aihua Bian
- 4Vanderbilt Center for Kidney Diseases, Vanderbilt University Medical Center, Nashville, Tennessee
- 6Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Thomas G. Stewart
- 4Vanderbilt Center for Kidney Diseases, Vanderbilt University Medical Center, Nashville, Tennessee
- 6Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Naji N. Abumrad
- 7Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - T. Alp Ikizler
- 1Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
- 4Vanderbilt Center for Kidney Diseases, Vanderbilt University Medical Center, Nashville, Tennessee
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17
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Fuller JC, Pitchford LM, Abumrad NN, Rathmacher JA. Subchronic (90-day) repeated dose oral toxicity study of 2-hydroxybenzylamine acetate in rabbit. Regul Toxicol Pharmacol 2018; 100:52-58. [PMID: 30359704 DOI: 10.1016/j.yrtph.2018.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/05/2018] [Accepted: 10/20/2018] [Indexed: 11/25/2022]
Abstract
2-hydroxybenzylamine (2-HOBA), a naturally occurring compound found in buckwheat, has potential for use as a nutrition supplement due to its ability to protect against the damaging effects of oxidative stress. In a series of rodent toxicity studies, 2-HOBA acetate was well-tolerated and did not produce any toxic effects over 28 or 90 days of repeated oral administration. However, it remained necessary to test the potential toxicity of 2-HOBA acetate in a non-rodent species. In this investigation, 2-HOBA acetate was orally administered to male and female New Zealand White Rabbits for 90 days at doses of 100, 500, and 1000 mg·kg BW-1·day-1 (n = 5 per sex/group). As previously observed in rodents, 2-HOBA acetate administration was well tolerated. No toxic effects of 2-HOBA acetate were detected in body weight, feed consumption, hematology, blood chemistry, urine chemistry, organ weights, gross pathology or histopathology. Based on these findings, the no-observed-adverse-effect-level of 2-HOBA acetate in rabbits was determined to be 1000 mg·kg BW-1·day-1, which was the highest dose tested. These results provide further support for the safety of 2-HOBA acetate administration.
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Affiliation(s)
| | | | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
| | - John A Rathmacher
- Metabolic Technologies, Inc., Ames, IA, 50010, USA; Department of Animal Science, Iowa State University, Ames, IA, 50010, USA.
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18
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Fuller JC, Pitchford LM, Abumrad NN, Rathmacher JA. Subchronic (90-day) repeated dose toxicity study of 2-hydroxybenzylamine acetate in rats. Regul Toxicol Pharmacol 2018; 99:225-232. [PMID: 30266239 DOI: 10.1016/j.yrtph.2018.09.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/20/2018] [Accepted: 09/23/2018] [Indexed: 11/16/2022]
Abstract
2-Hydroxybenzylamine (2-HOBA), a naturally occurring compound found in buckwheat, can protect cells and tissues from oxidative stress. In this study, 2-HOBA acetate was orally administered to male and female rats for 90 consecutive days at doses of 100, 500, and 1000 mg·kg BW-1·d-1 (n = 20 per sex/group). Subchronic administration of 2-HOBA was well tolerated at all dose levels. 2-HOBA-treated male rats were slightly heavier in the last weeks of the study, but this difference was very small (<5%), did not show a dose-response relationship, and was not observed in female rats. Similarly, some statistically significant changes in serum biochemistry and hematology parameters were noted, but these were not considered to be of biological or toxicological significance. Sporadic differences in organ weights were observed between groups, but all were small (<10%) and unlikely to indicate toxicity. The incidence of histopathological lesions was similar between treated and control groups across all organs. Based upon these findings, the no-observed-adverse-effect level was determined to be ≥ 1000 mg·kg BW-1·d-1, which was the highest dose tested. These results further support no toxicity associated with oral consumption of 2-HOBA acetate in rats and the continued development of 2-HOBA as a dietary supplement or functional food.
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Affiliation(s)
| | | | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
| | - John A Rathmacher
- Metabolic Technologies, Inc, Ames, IA 50010, USA; Department of Animal Science, Iowa State University, Ames, IA, 50010, USA.
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19
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Pitchford LM, Smith JD, Abumrad NN, Rathmacher JA, Fuller JC. Acute and 28-day repeated dose toxicity evaluations of 2-hydroxybenzylamine acetate in mice and rats. Regul Toxicol Pharmacol 2018; 98:190-198. [PMID: 30075181 DOI: 10.1016/j.yrtph.2018.07.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/27/2018] [Accepted: 07/28/2018] [Indexed: 11/30/2022]
Abstract
2-hydroxybenzylamine (2-HOBA), a compound naturally found in buckwheat, has been shown to protect cells and tissues from the damaging effects of oxidative stress. The purpose of this report was to evaluate 2-HOBA in preclinical oral rodent toxicity studies. This report includes the results from three oral toxicity studies in rodents: a preliminary 28-day feeding study in mice, a 14-day acute oral toxicity study in rats, and a 28-day repeated dose oral toxicity study in rats. The preliminary mouse feeding study showed no adverse effects of 2-HOBA at concentrations up to 0.456% by weight in feed, but decreased food intake and weight loss were observed at 1.56% 2-HOBA in the diet, likely due to poor palatability. In the acute dosing study, 2000 mg/kg BW 2-HOBA resulted in mortality in one of the six tested female rats, indicating a median lethal dose of 2500 mg/kg BW. In the 28-day repeated oral dose study, small differences were observed between 2-HOBA treated and control group rats, but none of these differences were determined to be of toxicological significance. Together, these studies support the lack of toxicity of oral administration of 2-HOBA acetate at doses up to 1000 mg/kg BW d-1 in rodents.
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Affiliation(s)
| | - Jodi D Smith
- Department of Veterinary Pathology, Iowa State University College of Veterinary Medicine, Ames, IA 50010, USA.
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - John A Rathmacher
- Metabolic Technologies, Inc, Ames, IA 50010, USA; Department of Animal Science, Iowa State University, Ames, IA 50010, USA.
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20
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Reddy IA, Smith NK, Erreger K, Ghose D, Saunders C, Foster DJ, Turner B, Poe A, Albaugh VL, McGuinness O, Hackett TA, Grueter BA, Abumrad NN, Flynn CR, Galli A. Bile diversion, a bariatric surgery, and bile acid signaling reduce central cocaine reward. PLoS Biol 2018; 16:e2006682. [PMID: 30048457 PMCID: PMC6061973 DOI: 10.1371/journal.pbio.2006682] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 06/21/2018] [Indexed: 01/22/2023] Open
Abstract
The gut-to-brain axis exhibits significant control over motivated behavior. However, mechanisms supporting this communication are poorly understood. We reveal that a gut-based bariatric surgery chronically elevates systemic bile acids and attenuates cocaine-induced elevations in accumbal dopamine. Notably, this surgery reduces reward-related behavior and psychomotor sensitization to cocaine. Utilizing a knockout mouse model, we have determined that a main mediator of these post-operative effects is the Takeda G protein-coupled bile acid receptor (TGR5). Viral restoration of TGR5 in the nucleus accumbens of TGR5 knockout animals is sufficient to restore cocaine reward, centrally localizing this TGR5-mediated modulation. These findings define TGR5 and bile acid signaling as pharmacological targets for the treatment of cocaine abuse and reveal a novel mechanism of gut-to-brain communication.
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Affiliation(s)
- India A. Reddy
- Neuroscience Program, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Nicholas K. Smith
- Neuroscience Program, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Kevin Erreger
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Dipanwita Ghose
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Christine Saunders
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Daniel J. Foster
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Brandon Turner
- Neuroscience Program, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Amanda Poe
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Vance L. Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Owen McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Troy A. Hackett
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Brad A. Grueter
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Charles Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
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Abstract
Obesity prevalence continues to increase worldwide, as do the numerous chronic diseases associated with obesity, including diabetes, non-alcoholic fatty liver disease, dyslipidemia, and hypertension. The prevalence of bariatric surgery also continues to increase and remains the most effective and sustainable treatment for obesity. Over the last several years, numerous prospective and longitudinal studies have demonstrated the benefits of bariatric surgery on weight loss, mortality, and other chronic diseases. Even though the mechanisms underlying many of these beneficial effects remain poorly understood, surgical management of obesity continues to increase given its unmatched efficacy. In this commentary, we discuss recent clinical advancements as well as several areas needed for future research, including indications for bariatric and metabolic surgery, determination of responders and non-responders, metabolic surgery in non-obese individuals, and the evolving role of bariatric surgery in adolescents.
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Affiliation(s)
- Vance L Albaugh
- Department of Surgery, MCN CC-2308, Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Naji N Abumrad
- Department of Surgery, MCN CC-2308, Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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22
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Shibao CA, Celedonio JE, Tamboli R, Sidani R, Love-Gregory L, Pietka T, Xiong Y, Wei Y, Abumrad NN, Abumrad NA, Flynn CR. CD36 Modulates Fasting and Preabsorptive Hormone and Bile Acid Levels. J Clin Endocrinol Metab 2018; 103:1856-1866. [PMID: 29546316 PMCID: PMC6446573 DOI: 10.1210/jc.2017-01982] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 03/07/2018] [Indexed: 01/16/2023]
Abstract
CONTEXT Abnormal fatty acid (FA) metabolism contributes to diabetes and cardiovascular disease. The FA receptor CD36 has been linked to risk of metabolic syndrome. In rodents CD36 regulates various aspects of fat metabolism, but whether it has similar actions in humans is unknown. We examined the impact of a coding single-nucleotide polymorphism in CD36 on postprandial hormone and bile acid (BA) responses. OBJECTIVE To examine whether the minor allele (G) of coding CD36 variant rs3211938 (G/T), which reduces CD36 level by ∼50%, influences hormonal responses to a high-fat meal (HFM). DESIGN Obese African American (AA) women carriers of the G allele of rs3211938 (G/T) and weight-matched noncarriers (T/T) were studied before and after a HFM. SETTING Two-center study. PARTICIPANTS Obese AA women. INTERVENTION HFM. MAIN OUTCOME MEASURES Early preabsorptive responses (10 minutes) and extended excursions in plasma hormones [C-peptide, insulin, incretins, ghrelin fibroblast growth factor (FGF)19, FGF21], BAs, and serum lipoproteins (chylomicrons, very-low-density lipoprotein) were determined. RESULTS At fasting, G-allele carriers had significantly reduced cholesterol and glycodeoxycholic acid and consistent but nonsignificant reductions of serum lipoproteins. Levels of GLP-1 and pancreatic polypeptide (PP) were reduced 60% to 70% and those of total BAs were 1.8-fold higher. After the meal, G-allele carriers displayed attenuated early (-10 to 10 minute) responses in insulin, C-peptide, GLP-1, gastric inhibitory peptide, and PP. BAs exhibited divergent trends in G allele carriers vs noncarriers concomitant with differential FGF19 responses. CONCLUSIONS CD36 plays an important role in the preabsorptive hormone and BA responses that coordinate brain and gut regulation of energy metabolism.
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Affiliation(s)
- Cyndya A Shibao
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Correspondence and Reprint Requests: Charles Robb Flynn, PhD, Department of Surgery, MRBIV Room 8465A, 2213 Garland Avenue, Vanderbilt University Medical Center, Nashville, Tennessee 37232. E-mail: ; or Cyndya Shibao, MD, Department of Medicine, Division of Medicine, 562 Preston Research Building, Vanderbilt University Medical Center, Nashville, Tennessee 37232. E-mail:
| | - Jorge E Celedonio
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Robyn Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Reem Sidani
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Latisha Love-Gregory
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St. Louis, Missouri
| | - Terri Pietka
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St. Louis, Missouri
| | - Yanhua Xiong
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Yan Wei
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of General Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Nada A Abumrad
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, St. Louis, Missouri
| | - Charles Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
- Correspondence and Reprint Requests: Charles Robb Flynn, PhD, Department of Surgery, MRBIV Room 8465A, 2213 Garland Avenue, Vanderbilt University Medical Center, Nashville, Tennessee 37232. E-mail: ; or Cyndya Shibao, MD, Department of Medicine, Division of Medicine, 562 Preston Research Building, Vanderbilt University Medical Center, Nashville, Tennessee 37232. E-mail:
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23
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Savani U, Jung DK, Crowe JE, Abumrad NN, Powers AC, Jagasia M, Cornell RF, Goodman S, Kassim AA, Culos KA, Gatwood KS, Byrne MT, Engelhardt BG. Metabolic Complications Precede Alloreactivity and are Characterized by Changes in Th1/Th17 Immunity. Biol Blood Marrow Transplant 2018. [DOI: 10.1016/j.bbmt.2017.12.185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Deger SM, Hung AM, Gamboa JL, Siew ED, Ellis CD, Booker C, Sha F, Li H, Bian A, Stewart TG, Zent R, Mitch WE, Abumrad NN, Ikizler TA. Systemic inflammation is associated with exaggerated skeletal muscle protein catabolism in maintenance hemodialysis patients. JCI Insight 2017; 2:95185. [PMID: 29202452 DOI: 10.1172/jci.insight.95185] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/12/2017] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Systemic inflammation and muscle wasting are highly prevalent and coexist in patients on maintenance hemodialysis (MHD). We aimed to determine the effects of systemic inflammation on skeletal muscle protein metabolism in MHD patients. METHODS Whole body and skeletal muscle protein turnover were assessed by stable isotope kinetic studies. We incorporated expressions of E1, E214K, E3αI, E3αII, MuRF-1, and atrogin-1 in skeletal muscle tissue from integrin β1 gene KO CKD mice models. RESULTS Among 129 patients with mean (± SD) age 47 ± 12 years, 74% were African American, 73% were male, and 22% had diabetes mellitus. Median high-sensitivity C-reactive protein (hs-CRP) concentration was 13 (interquartile range 0.8, 33) mg/l. There were statistically significant associations between hs-CRP and forearm skeletal muscle protein synthesis, degradation, and net forearm skeletal muscle protein balance (P < 0.001 for all). The associations remained statistically significant after adjustment for clinical and demographic confounders, as well as in sensitivity analysis, excluding patients with diabetes mellitus. In attempting to identify potential mechanisms involved in this correlation, we show increased expressions of E1, E214K, E3αI, E3αII, MuRF-1, and atrogin-1 in skeletal muscle tissue obtained from an animal model of chronic kidney disease. CONCLUSION These data suggest that systemic inflammation is a strong and independent determinant of skeletal muscle protein homeostasis in MHD patients, providing rationale for further studies using anticytokine therapies in patients with underlying systemic inflammation. FUNDING This study was in part supported by NIH grants R01 DK45604 and 1K24 DK62849, the Clinical Translational Science Award UL1-TR000445 from the National Center for Advancing Translational Sciences, the Veterans Administration Merit Award I01 CX000414, the SatelliteHealth Normon Coplon Extramural Grant Program, and the FDA grant 000943.
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Affiliation(s)
- Serpil M Deger
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA.,CSRD&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease
| | - Adriana M Hung
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA.,CSRD&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease
| | | | - Edward D Siew
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA.,CSRD&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease
| | - Charles D Ellis
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease
| | - Cindy Booker
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA.,CSRD&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease
| | - Feng Sha
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA
| | - Haiming Li
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA
| | - Aihua Bian
- Department of Biostatistics, VUMC, Nashville, Tennessee, USA
| | | | - Roy Zent
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease
| | - William E Mitch
- Selzman Institute for Kidney Health, Baylor College of Medicine, Department of Medicine, Houston, Texas, USA
| | | | - T Alp Ikizler
- Division of Nephrology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee, USA.,CSRD&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease
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25
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Dunn JP, Abumrad NN, Kessler RM, Patterson BW, Li R, Marks-Shulman P, Tamboli RA. Caloric Restriction-Induced Decreases in Dopamine Receptor Availability are Associated with Leptin Concentration. Obesity (Silver Spring) 2017; 25:1910-1915. [PMID: 28944597 PMCID: PMC5718041 DOI: 10.1002/oby.22023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/16/2017] [Accepted: 08/21/2017] [Indexed: 11/08/2022]
Abstract
OBJECTIVE It has been previously reported that early after Roux-en-Y-gastric bypass, dopamine (DA) type 2 and 3 receptor (D2/3R) binding potential (BPND ) was decreased from preoperative levels. The current study aimed to determine whether calorie restriction without weight loss modifies D2/3R BPND and whether such changes are explained by neuroendocrine regulation. METHODS Fifteen females with obesity (BMI = 39 ± 6 kg/m2 ) were studied before and after ∼10 days of a very-low-calorie-diet (VLCD). Outcome measures included fasting insulin, leptin, acyl ghrelin, and glucose, and insulin sensitivity and disposition index were estimated using the oral-minimal model (OMM) method. Participants underwent positron emission tomography scanning with the displaceable radioligand [18 F]fallypride to estimate available regional D2/3R levels. Regions of interest included the caudate, putamen, ventral striatum, hypothalamus, and substantia nigra (SN). RESULTS With the VLCD, weight decreased slightly (-3 kg). Insulin, glucose, and leptin decreased significantly, but there was no change in acyl ghrelin or measures from OMM. SN D2/3R BPND decreased significantly, with trends toward decreased levels in the remaining regions. The decrease in leptin concentration strongly predicted the change in D2/3R BPND in all regions (all P ≤ 0.004). CONCLUSIONS In obesity, reductions in regional D2/3R availability after VLCD are suggestive of increased endogenous DA competing with the radioligand. Changes in regional D2/3R availability were associated with decreases in leptin concentrations that occurred before clinically significant weight loss.
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Affiliation(s)
- Julia P. Dunn
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
- Veterans Administration St. Louis Health Care System, St. Louis, Missouri, U.S.A
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Robert M. Kessler
- Department of Radiology, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Bruce W. Patterson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Rui Li
- Department of Radiology, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Pamela Marks-Shulman
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Robyn A. Tamboli
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
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26
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Tamboli RA, Antoun J, Sidani RM, Clements BA, Eckert EA, Marks-Shulman P, Gaylinn BD, Williams DB, Clements RH, Albaugh VL, Abumrad NN. Metabolic responses to exogenous ghrelin in obesity and early after Roux-en-Y gastric bypass in humans. Diabetes Obes Metab 2017; 19:1267-1275. [PMID: 28345790 PMCID: PMC5568950 DOI: 10.1111/dom.12952] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 03/22/2017] [Accepted: 03/23/2017] [Indexed: 12/11/2022]
Abstract
AIMS Ghrelin is a gastric-derived hormone that stimulates growth hormone (GH) secretion and has a multi-faceted role in the regulation of energy homeostasis, including glucose metabolism. Circulating ghrelin concentrations are modulated in response to nutritional status, but responses to ghrelin in altered metabolic states are poorly understood. We investigated the metabolic effects of ghrelin in obesity and early after Roux-en-Y gastric bypass (RYGB). MATERIALS AND METHODS We assessed central and peripheral metabolic responses to acyl ghrelin infusion (1 pmol kg-1 min-1 ) in healthy, lean subjects (n = 9) and non-diabetic, obese subjects (n = 9) before and 2 weeks after RYGB. Central responses were assessed by GH and pancreatic polypeptide (surrogate for vagal activity) secretion. Peripheral responses were assessed by hepatic and skeletal muscle insulin sensitivity during a hyperinsulinaemic-euglycaemic clamp. RESULTS Ghrelin-stimulated GH secretion was attenuated in obese subjects, but was restored by RYGB to a response similar to that of lean subjects. The heightened pancreatic polypeptide response to ghrelin infusion in the obese was attenuated after RYGB. Hepatic glucose production and hepatic insulin sensitivity were not altered by ghrelin infusion in RYGB subjects. Skeletal muscle insulin sensitivity was impaired to a similar degree in lean, obese and post-RYGB individuals in response to ghrelin infusion. CONCLUSIONS These data suggest that obesity is characterized by abnormal central, but not peripheral, responsiveness to ghrelin that can be restored early after RYGB before significant weight loss. Further work is necessary to fully elucidate the role of ghrelin in the metabolic changes that occur in obesity and following RYGB.
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Affiliation(s)
- Robyn A. Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Joseph Antoun
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Reem M. Sidani
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - B. Austin Clements
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Emily A. Eckert
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Pam Marks-Shulman
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Bruce D. Gaylinn
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia, Charlottesville, VA
| | | | - Ronald H. Clements
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Vance L. Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN
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27
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Abstract
Bariatric surgery, specifically Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), are the most effective and durable treatments for morbid obesity and potentially a viable treatment for type 2 diabetes (T2D). The resolution rate of T2D following these procedures is between 40 and 80% and far surpasses that achieved by medical management alone. The molecular basis for this improvement is not entirely understood, but has been attributed in part to the altered enterohepatic circulation of bile acids. In this review we highlight how bile acids potentially contribute to improved lipid and glucose homeostasis, insulin sensitivity and energy expenditure after these procedures. The impact of altered bile acid levels in enterohepatic circulation is also associated with changes in gut microflora, which may further contribute to some of these beneficial effects. We highlight the beneficial effects of experimental surgical procedures in rodents that alter bile secretory flow without gastric restriction or altering nutrient flow. This information suggests a role for bile acids beyond dietary fat emulsification in altering whole body glucose and lipid metabolism strongly, and also suggests emerging roles for the activation of the bile acid receptors farnesoid x receptor (FXR) and G-protein coupled bile acid receptor (TGR5) in these improvements. The limitations of rodent studies and the current state of our understanding is reviewed and the potential effects of bile acids mediating the short- and long-term metabolic improvements after bariatric surgery is critically examined.
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MESH Headings
- Animals
- Bile Acids and Salts/metabolism
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/microbiology
- Diabetes Mellitus, Type 2/pathology
- Diabetes Mellitus, Type 2/surgery
- Enterohepatic Circulation
- Gastrectomy
- Gastric Bypass
- Gastrointestinal Microbiome/physiology
- Gene Expression Regulation
- Glucose/metabolism
- Homeostasis/physiology
- Humans
- Insulin Resistance
- Obesity, Morbid/metabolism
- Obesity, Morbid/microbiology
- Obesity, Morbid/pathology
- Obesity, Morbid/surgery
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Rodentia
- Signal Transduction
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Affiliation(s)
- Vance L Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Babak Banan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Hana Ajouz
- American University of Beirut, Beirut, Lebanon
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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Arnold AC, Garland EM, Celedonio JE, Raj SR, Abumrad NN, Biaggioni I, Robertson D, Luther JM, Shibao CA. Hyperinsulinemia and Insulin Resistance in Dopamine β-Hydroxylase Deficiency. J Clin Endocrinol Metab 2017; 102:10-14. [PMID: 27778639 PMCID: PMC5413093 DOI: 10.1210/jc.2016-3274] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/21/2016] [Indexed: 12/30/2022]
Abstract
CONTEXT Dopamine β-hydroxylase (DBH) deficiency is a rare genetic disorder characterized by failure to convert dopamine to norepinephrine. DBH-deficient patients lack sympathetic adrenergic function and are therefore predisposed to orthostatic hypotension. DBH-deficient mice exhibit hyperinsulinemia, lower plasma glucose levels, and insulin resistance due to loss of tonic sympathetic inhibition of insulin secretion. The impact of DBH deficiency on glucose homeostasis in humans is unknown. CASE DESCRIPTION We describe the metabolic profile of an adolescent female DBH-deficient patient. The patient underwent genetic testing, cardiovascular autonomic function testing, and evaluation of insulin secretion and sensitivity with hyperglycemic clamp under treatment-naive conditions. All procedures were repeated after 1 year of treatment with the norepinephrine prodrug droxidopa (300 mg, 3 times a day). Genetic testing showed a homozygous mutation in the DBH gene (rs74853476). Under treatment-naive conditions, she had undetectable plasma epinephrine and norepinephrine levels, resulting in sympathetic noradrenergic failure and orthostatic hypotension (-32 mm Hg supine to seated). She had high adiposity (41%) and fasting plasma insulin levels (25 μU/mL), with normal glucose (91 mg/dL). Hyperglycemic clamp revealed increased glucose-stimulated insulin secretion and insulin resistance. Droxidopa restored plasma norepinephrine and improved orthostatic tolerance, with modest effects on glucose homeostasis. CONCLUSIONS We provide evidence for impairment in cardiovascular autonomic regulation, hyperinsulinemia, enhanced glucose-stimulated insulin secretion, and insulin resistance in a DBH-deficient patient. These metabolic derangements were not corrected by chronic droxidopa treatment. These findings provide insight into the pathophysiology and treatment of DBH deficiency and into the importance of catecholaminergic mechanisms to resting metabolism.
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Affiliation(s)
- Amy C. Arnold
- Department of Neural and Behavioral Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
- 2Division of Clinical Pharmacology and
| | | | | | - Satish R. Raj
- 2Division of Clinical Pharmacology and
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 2T9, Canada
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232; and
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29
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Knuth ND, Johannsen DL, Tamboli RA, Marks-Shulman PA, Huizenga R, Chen KY, Abumrad NN, Ravussin E, Hall KD. Erratum: Metabolic adaptation following massive weight loss is related to the degree of energy imbalance and changes in circulating leptin. Obesity (Silver Spring) 2016; 24:2248. [PMID: 27670403 PMCID: PMC6330887 DOI: 10.1002/oby.21634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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30
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Deger SM, Hung AM, Ellis CD, Booker C, Bian A, Chen G, Abumrad NN, Ikizler TA. High Dose Omega-3 Fatty Acid Administration and Skeletal Muscle Protein Turnover in Maintenance Hemodialysis Patients. Clin J Am Soc Nephrol 2016; 11:1227-1235. [PMID: 27281699 PMCID: PMC4934832 DOI: 10.2215/cjn.04150415] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 03/03/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Protein energy wasting and systemic inflammation are prevalent in maintenance hemodialysis (MHD) patients. Omega-3 (ω-3) fatty acids have anti-inflammatory properties and have been shown to improve protein homeostasis. We hypothesized that administration of high-dose (2.9 g/d) ω-3 would be associated with decreased muscle protein breakdown in MHD patients with systemic inflammation. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS This is a substudy from a randomized, placebo-controlled study (NCT00655525). Patients were recruited between September 2008 and June 2011. Primary inclusion criteria included signs of chronic inflammation (average C-reactive protein of ≥5 mg/L over three consecutive measurements), lack of active infectious or inflammatory disease, no hospitalization within 1 month prior to the study, and not receiving steroids (>5 mg/d) and/or immunosuppressive agents. The primary outcomes were forearm muscle and whole body protein breakdown and synthesis before and after the intervention. The patients received ω-3 (n=11) versus placebo (n=9) for 12 weeks. Analysis of covariance was used to compare outcome variables at 12 weeks. Models were adjusted for a propensity score that was derived from age, sex, race, baseline high sensitivity C-reactive protein, diabetes mellitus, and fat mass because the groups were not balanced for several characteristics. RESULTS Compared with placebo, ω-3 supplementation was significantly associated with decreased muscle protein breakdown at 12 weeks (-31, [interquartile range, -98--13] versus 26 [interquartile range, 13-87] µg/100 ml per min; P=0.01), which remained significant after multivariate adjustment (-46, [95% confidence interval, -102 to -1] µg/100 ml per min). ω-3 Supplementation resulted in decreased forearm muscle protein synthesis while the rate in the placebo group increased; however, there is no longer a statistically significant difference in skeletal muscle protein synthesis or in net protein balance after multivariate adjustment. There was no statistically significant effect of ω-3 supplementation on whole body protein synthesis or breakdown. CONCLUSIONS High-dose ω-3 supplementation over 12 weeks in MHD patients with systemic inflammation was associated with attenuation of forearm muscle protein breakdown but did not influence skeletal muscle protein synthesis, skeletal muscle net protein balance or any component of the whole-body protein balance. These results should be interpreted cautiously given the imbalance in the two groups and the short duration of the intervention.
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Affiliation(s)
- Serpil Muge Deger
- Divisions of *Nephrology, and
- Clinical Science Research and Development, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Adriana M. Hung
- Divisions of *Nephrology, and
- Clinical Science Research and Development, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee
| | | | | | | | | | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - T. Alp Ikizler
- Divisions of *Nephrology, and
- Clinical Science Research and Development, Veterans Administration Tennessee Valley Healthcare System, Nashville, Tennessee
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31
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Shibao CA, Celedonio JE, Ramirez CE, Love-Gregory L, Arnold AC, Choi L, Okamoto LE, Gamboa A, Biaggioni I, Abumrad NN, Abumrad NA. A Common CD36 Variant Influences Endothelial Function and Response to Treatment with Phosphodiesterase 5 Inhibition. J Clin Endocrinol Metab 2016; 101:2751-8. [PMID: 27144937 PMCID: PMC4929841 DOI: 10.1210/jc.2016-1294] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
CONTEXT The scavenger receptor CD36 influences the endothelial nitric oxide-cGMP pathway in vitro. Genetic variants that alter CD36 level are common in African Americans (AAs), a population at high risk of endothelial dysfunction. OBJECTIVE To examine if the minor allele (G) of coding CD36 variant rs3211938 (G/T) which reduces CD36 level by approximately 50% influences endothelial function, insulin sensitivity (IS), and the response to treatment with the nitric oxide-cGMP potentiator sildenafil. DESIGN IS (frequently sampled iv glucose tolerance) and endothelial function (flow mediated dilation [FMD]) were determined in age- and body mass index-matched obese AA women with or without the G allele of rs3211938 (protocol 1). Effect of chronic sildenafil treatment on IS and FMD was tested in AA women with metabolic syndrome and with/without the CD36 variant, using a randomized, placebo-controlled trial (protocol 2). SETTING Two-center study. PARTICIPANTS Obese AA women. INTERVENTION A total of 20-mg sildenafil citrate or placebo thrice daily for 4 weeks. MAIN OUTCOME IS, FMD. RESULTS G allele carriers have lower FMD (P = .03) and cGMP levels (P = .01) than noncarriers. Sildenafil did not improve IS, mean difference 0.12 (95% confidence interval [CI], -0.33 to 0.58; P = .550). However, there was a significant interaction between FMD response to sildenafil and rs3211938 (P = .018). FMD tended to improve in G carriers, 2.9 (95% CI, -0.9 to 6.8; P = .126), whereas it deteriorated in noncarriers, -2.6 (95% CI, -5.1 to -0.1; P = .04). CONCLUSIONS The data document influence of a common genetic variant on susceptibility to endothelial dysfunction and its response to sildenafil treatment.
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Affiliation(s)
- Cyndya A Shibao
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Jorge E Celedonio
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Claudia E Ramirez
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Latisha Love-Gregory
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Amy C Arnold
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Leena Choi
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Luis E Okamoto
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Alfredo Gamboa
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Italo Biaggioni
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Naji N Abumrad
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Nada A Abumrad
- Department of Medicine (C.A.S., J.E.C., C.E.R., A.C.A., L.E.O., A.G., I.B.), Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232; Department of Medicine (L.L.-G., N.A.A.), Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110; Department of Biostatistics (L.C.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232; and Department of Surgery (N.N.A.), Vanderbilt University School of Medicine, Nashville, Tennessee 37232
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Tamboli RA, Sidani RM, Garcia AE, Antoun J, Isbell JM, Albaugh VL, Abumrad NN. Jejunal administration of glucose enhances acyl ghrelin suppression in obese humans. Am J Physiol Endocrinol Metab 2016; 311:E252-9. [PMID: 27279247 PMCID: PMC4967145 DOI: 10.1152/ajpendo.00082.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 05/26/2016] [Indexed: 01/03/2023]
Abstract
Ghrelin is a gastric hormone that stimulates hunger and worsens glucose metabolism. Circulating ghrelin is decreased after Roux-en-Y gastric bypass (RYGB) surgery; however, the mechanism(s) underlying this change is unknown. We tested the hypothesis that jejunal nutrient exposure plays a significant role in ghrelin suppression after RYGB. Feeding tubes were placed in the stomach or jejunum in 13 obese subjects to simulate pre-RYGB or post-RYGB glucose exposure to the gastrointestinal (GI) tract, respectively, without the confounding effects of caloric restriction, weight loss, and surgical stress. On separate study days, the plasma glucose curves obtained with either gastric or jejunal administration of glucose were replicated with intravenous (iv) infusions of glucose. These "isoglycemic clamps" enabled us to determine the contribution of the GI tract and postabsorptive plasma glucose to acyl ghrelin suppression. Plasma acyl ghrelin levels were suppressed to a greater degree with jejunal glucose administration compared with gastric glucose administration (P < 0.05). Jejunal administration of glucose also resulted in a greater suppression of acyl ghrelin than the corresponding isoglycemic glucose infusion (P ≤ 0.01). However, gastric and isoglycemic iv glucose infusions resulted in similar degrees of acyl ghrelin suppression (P > 0.05). Direct exposure of the proximal jejunum to glucose increases acyl ghrelin suppression independent of circulating glucose levels. The enhanced suppression of acyl ghrelin after RYGB may be due to a nutrient-initiated signal in the jejunum that regulates ghrelin secretion.
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Affiliation(s)
- Robyn A Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Reem M Sidani
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Anna E Garcia
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Joseph Antoun
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - James M Isbell
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Vance L Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
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Abstract
Obesity and its associated medical conditions continue to increase and add significant burden to patients, as well as health-care systems, worldwide. Bariatric surgery is the most effective treatment for severe obesity and its comorbidities, and resolution of diabetes is weight loss-independent in the case of some operations. Although these weight-independent effects are frequently described clinically, the mechanisms behind them are not well understood and remain an intense area of focus in the growing field of metabolic and bariatric surgery. Perceptions of the mechanisms responsible for the beneficial metabolic effects of metabolic/bariatric operations have shifted from being mostly restrictive and malabsorption over the last 10 to 15 years to being more neuro-hormonal in origin. In this review, we describe recent basic and clinical findings of the major clinical procedures (adjustable gastric banding, vertical sleeve gastrectomy, Roux-en-Y gastric bypass, and biliopancreatic diversion) as well as other experimental procedures (ileal interposition and bile diversion) that recapitulate many of the metabolic effects of these complex operations in a simpler fashion. As the role of bile acids and the gut microbiome on metabolism is becoming increasingly well described, their potential roles in these improvements following metabolic surgery are becoming better appreciated. Bile acid and gut microbiome changes, in light of recent developments, are discussed in the context of these surgical procedures, as well as their implications for future study.
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Affiliation(s)
- Vance L Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, USA
| | - C Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, USA
| | - Robyn A Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, USA
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, USA
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Garcia AE, Kasim N, Tamboli RA, Gonzalez RS, Antoun J, Eckert EA, Marks-Shulman PA, Dunn J, Wattacheril J, Wallen T, Abumrad NN, Flynn CR. Lipoprotein Profiles in Class III Obese Caucasian and African American Women with Nonalcoholic Fatty Liver Disease. PLoS One 2015; 10:e0142676. [PMID: 26599819 PMCID: PMC4657895 DOI: 10.1371/journal.pone.0142676] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/26/2015] [Indexed: 12/15/2022] Open
Abstract
Triglyceride content in the liver is regulated by the uptake, production and elimination of lipoproteins, and derangements in these processes contribute to nonalcoholic fatty liver disease (NAFLD). Previous studies show a direct relationship between intrahepatic fat and production of apolipoprotein B100 (apoB100) containing particles, VLDL and LDL, but little consensus exists regarding changes in lipoprotein production in the development of simple steatosis (SS) versus nonalcoholic steatohepatitis (NASH). Further, ethnic variations in lipoproteins among SS and NASH are unknown as is how such variations might contribute to the differential prevalence of disease among Caucasians versus African Americans. In this study, we assessed plasma lipoprotein profiles by nuclear magnetic resonance (NMR) spectroscopy in 70 non-diabetic class III obese females recruited from the surgical weight loss clinic. Of these, 51 females were stratified by biopsy-staged NAFLD severity (histologically normal, SS, or NASH). NASH females displayed increased circulating triglycerides and increased VLDL particle number and size relative to those with histologically normal livers, while total and large LDL concentration decreased in SS versus NASH and correlated with increased insulin resistance (via HOMA2-IR). When Caucasian women were examined alone (n = 41), VLDL and triglycerides increased between normal and SS, while total LDL and apoB100 decreased between SS and NASH along with increased insulin resistance. Compared to Caucasians with SS, African American women with SS displayed reduced triglycerides, VLDL, and small LDL and a more favorable small to large HDL ratio despite having increased BMI and HOMA2-IR. These findings suggest that ApoB100 and lipoprotein subclass particle number and size can delineate steatosis from NASH in obese Caucasian females, but should be interpreted with caution in other ethnicities as African Americans with SS display relatively improved lipoprotein profiles. This may reflect variation in the relationship between dyslipidemia and NAFLD progression across gender and ethnicity.
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Affiliation(s)
- Anna E. Garcia
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Nader Kasim
- Le Bonheur Children’s Foundation Research Center, Memphis, Tennessee 38103, United States of America
| | - Robyn A. Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Raul S. Gonzalez
- Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Joseph Antoun
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Emily A. Eckert
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Pamela A. Marks-Shulman
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Julia Dunn
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Julia Wattacheril
- Columbia University College of Physicians and Surgeons, New York, New York, United States of America
| | - Taylor Wallen
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States of America
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Charles Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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Albaugh VL, Flynn CR, Cai S, Xiao Y, Tamboli RA, Abumrad NN. Early Increases in Bile Acids Post Roux-en-Y Gastric Bypass Are Driven by Insulin-Sensitizing, Secondary Bile Acids. J Clin Endocrinol Metab 2015; 100. [PMID: 26196952 PMCID: PMC4570157 DOI: 10.1210/jc.2015-2467] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
CONTEXT Roux-en-Y gastric bypass (RYGB) is the most effective treatment for morbid obesity and resolution of diabetes. Over the last decade, it has become well accepted that this resolution of diabetes occurs before significant weight loss; however, the mechanisms behind this effect remain unknown and could represent novel therapeutic targets for obesity and diabetes. Bile acids have been identified as putative mediators of these weight loss-independent effects. OBJECTIVE To identify the longitudinal changes in bile acids after RYGB, which may provide mechanistic insight into the weight loss-independent effects of RYGB. DESIGN Observational study before/after intervention. SETTING Academic medical center. PATIENTS/PARTICIPANTS Samples were collected from morbidly obese patients (n = 21) before and after RYGB. INTERVENTION RYGB. MAIN OUTCOME MEASURES Seventeen individual bile acid species were measured preoperatively and at 1, 6, 12, and 24 months postoperatively. Anthropometric, hormonal, and hyperinsulinemic-euglycemic clamp data were also examined to identify physiological parameters associated with bile acid changes. RESULTS Fasting total plasma bile acids increased after RYGB; however, increases were bimodal and were observed only at 1 (P < .05) and 24 months (P < .01). One-month increases were secondary to surges in ursodeoxycholic acid and its glycine and taurine conjugates, bacterially derived bile acids with putative insulin-sensitizing effects. Increases at 24 months were due to gradual rises in primary unconjugated bile acids as well as deoxycholic acid and its glycine conjugate. Plasma bile acid changes were not significantly associated with any anthropometric or hormonal measures, although hepatic insulin sensitivity was significantly improved at 1 month. CONCLUSIONS Overall findings suggest that bacterially derived bile acids may mediate the early improvements at 1 month after RYGB. Future studies should examine the changes in specific bile acid chemical species after bariatric procedures and bile acid-specific signaling changes.
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Affiliation(s)
- Vance L Albaugh
- Department of Surgery (V.L.A., C.R.F., R.A.T., N.N.A.), Vanderbilt University Medical Center, Nashville, Tennessee 37232; Rosalind Franklin University (S.C.), North Chicago, Illinois 60064; and Department of Biochemistry (Y.X.), Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Charles Robb Flynn
- Department of Surgery (V.L.A., C.R.F., R.A.T., N.N.A.), Vanderbilt University Medical Center, Nashville, Tennessee 37232; Rosalind Franklin University (S.C.), North Chicago, Illinois 60064; and Department of Biochemistry (Y.X.), Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Steven Cai
- Department of Surgery (V.L.A., C.R.F., R.A.T., N.N.A.), Vanderbilt University Medical Center, Nashville, Tennessee 37232; Rosalind Franklin University (S.C.), North Chicago, Illinois 60064; and Department of Biochemistry (Y.X.), Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Yi Xiao
- Department of Surgery (V.L.A., C.R.F., R.A.T., N.N.A.), Vanderbilt University Medical Center, Nashville, Tennessee 37232; Rosalind Franklin University (S.C.), North Chicago, Illinois 60064; and Department of Biochemistry (Y.X.), Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Robyn A Tamboli
- Department of Surgery (V.L.A., C.R.F., R.A.T., N.N.A.), Vanderbilt University Medical Center, Nashville, Tennessee 37232; Rosalind Franklin University (S.C.), North Chicago, Illinois 60064; and Department of Biochemistry (Y.X.), Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Naji N Abumrad
- Department of Surgery (V.L.A., C.R.F., R.A.T., N.N.A.), Vanderbilt University Medical Center, Nashville, Tennessee 37232; Rosalind Franklin University (S.C.), North Chicago, Illinois 60064; and Department of Biochemistry (Y.X.), Vanderbilt University Medical Center, Nashville, Tennessee 37232
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Sharifnia T, Antoun J, Verriere TGC, Suarez G, Wattacheril J, Wilson KT, Peek RM, Abumrad NN, Flynn CR. Hepatic TLR4 signaling in obese NAFLD. Am J Physiol Gastrointest Liver Physiol 2015; 309:G270-8. [PMID: 26113297 PMCID: PMC4537925 DOI: 10.1152/ajpgi.00304.2014] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 06/11/2015] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease occurs frequently in the setting of metabolic syndrome, but the factors leading to nonalcoholic steatohepatitis (NASH) are not fully understood. This study investigated Toll-like receptor 4 (TLR4) signaling in human liver with the goal of delineating whether activation of this pathway segregates those with nonalcoholic fatty liver from those with NASH. Experiments were performed using liver biopsy tissue obtained from class III obese subjects undergoing bariatric surgery, and extended to an immortalized human hepatocyte HepaRG cell line and primary human hepatocytes. The bacterial endotoxin lipopolysaccharide (LPS) and total free fatty acid levels were significantly increased in plasma of NASH patients. TLR4 mRNA levels were significantly increased in subjects with NASH compared with NAFL as was interferon regulatory factor (IRF) 3 in the myeloid differentiation factor 88-independent signaling pathway. In HepaRG cells, nuclear factor-κB (NF-κB) nuclear translocation and functional activity increased following treatment with the fatty acid, palmitate, and following exposure to LPS compared with hepatocytes stimulated with a lipogenic treatment that induced de novo lipogenesis. Palmitate and LPS induction of NF-κB activity was partially attenuated by chemical- or small-interfering RNA-mediated inhibition of TLR4. Expression of TLR4 and its downstream mediators was upregulated with palmitate and LPS. Similar results were observed using primary human hepatocytes from a lean donor. Interestingly, NF-κB activity assays showed obese donor hepatocytes were resistant to chemical TLR4 inhibition. In conclusion, TLR4 expression is upregulated in a large cohort of NASH patients, compared with those with NAFL, and this occurs within the setting of increased LPS and fatty acids.
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Affiliation(s)
- Torfay Sharifnia
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Joseph Antoun
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Thomas G. C. Verriere
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Giovanni Suarez
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Julia Wattacheril
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Keith T. Wilson
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; ,3Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Richard M. Peek
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Naji N. Abumrad
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Charles R. Flynn
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
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Kim SH, Wu SY, Baek JI, Choi SY, Su Y, Flynn CR, Gamse JT, Ess KC, Hardiman G, Lipschutz JH, Abumrad NN, Rockey DC. A post-developmental genetic screen for zebrafish models of inherited liver disease. PLoS One 2015; 10:e0125980. [PMID: 25950913 PMCID: PMC4423964 DOI: 10.1371/journal.pone.0125980] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/27/2015] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease such as simple steatosis, nonalcoholic steatohepatitis (NASH), cirrhosis and fibrosis. However, the molecular pathogenesis and genetic variations causing NAFLD are poorly understood. The high prevalence and incidence of NAFLD suggests that genetic variations on a large number of genes might be involved in NAFLD. To identify genetic variants causing inherited liver disease, we used zebrafish as a model system for a large-scale mutant screen, and adopted a whole genome sequencing approach for rapid identification of mutated genes found in our screen. Here, we report on a forward genetic screen of ENU mutagenized zebrafish. From 250 F2 lines of ENU mutagenized zebrafish during post-developmental stages (5 to 8 days post fertilization), we identified 19 unique mutant zebrafish lines displaying visual evidence of hepatomegaly and/or steatosis with no developmental defects. Histological analysis of mutants revealed several specific phenotypes, including common steatosis, micro/macrovesicular steatosis, hepatomegaly, ballooning, and acute hepatocellular necrosis. This work has identified multiple post-developmental mutants and establishes zebrafish as a novel animal model for post-developmental inherited liver disease.
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Affiliation(s)
- Seok-Hyung Kim
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
- * E-mail:
| | - Shu-Yu Wu
- Department of Biology, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Jeong-In Baek
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Soo Young Choi
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Yanhui Su
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Charles R. Flynn
- Department of Surgery, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Joshua T. Gamse
- Department of Biology, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Kevin C. Ess
- Department of Pediatrics, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Gary Hardiman
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Joshua H. Lipschutz
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
- Department of Medicine, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, 29401, the United States of America
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Don C. Rockey
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
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Knuth ND, Johannsen DL, Tamboli RA, Marks-Shulman PA, Huizenga R, Chen KY, Abumrad NN, Ravussin E, Hall KD. Metabolic adaptation following massive weight loss is related to the degree of energy imbalance and changes in circulating leptin. Obesity (Silver Spring) 2014; 22:2563-9. [PMID: 25236175 PMCID: PMC4236233 DOI: 10.1002/oby.20900] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 08/20/2014] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To measure changes in resting metabolic rate (RMR) and body composition in obese subjects following massive weight loss achieved via bariatric surgery or calorie restriction plus vigorous exercise. METHODS Body composition and RMR were measured in 13 pairs of obese subjects retrospectively matched for sex, body mass index, weight, and age who underwent either Roux-en-Y gastric bypass surgery (RYGB) or participated in "The Biggest Loser" weight loss competition (BLC). RESULTS Both groups had similar final weight loss (RYGB: 40.2 ± 12.7 kg, BLC: 48.8 ± 14.9 kg; P = 0.14); however, RYGB lost a larger proportion of their weight as fat-free mass (FFM) (RYGB: 30 ± 12%, BLC: 16 ± 8% [P < 0.01]). In both groups, RMR decreased significantly more than expected based on measured body composition changes. The magnitude of this metabolic adaptation was correlated with the degree of energy imbalance (r = 0.55, P = 0.004) and the decrease in circulating leptin (r = 0.47, P = 0.02). CONCLUSIONS Calorie restriction along with vigorous exercise in BLC participants resulted in preservation of FFM and greater metabolic adaption compared to RYGB subjects despite comparable weight loss. Metabolic adaptation was related to the degree of energy imbalance and the changes in circulating leptin.
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Affiliation(s)
- Nicolas D. Knuth
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | | | | | | | | | - Kong Y. Chen
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Naji N. Abumrad
- Vanderbilt University School of Medicine, Nashville, TN, 37232
| | - Eric Ravussin
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
| | - Kevin D. Hall
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
- To whom correspondence should be addressed: Kevin D. Hall, Ph.D., National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, 12A South Drive, Room 4007, Bethesda, MD 20892,
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Reddy IA, Wasserman DH, Ayala JE, Hasty A, Abumrad NN, Galli A. Striatal dopamine homeostasis is altered in mice following Roux-en-Y gastric bypass surgery. ACS Chem Neurosci 2014; 5:943-51. [PMID: 25068716 PMCID: PMC4324416 DOI: 10.1021/cn500137d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 07/25/2014] [Indexed: 12/13/2022] Open
Abstract
Roux-en-Y gastric bypass (RYGB) is an effective treatment for obesity. Importantly, weight loss following RYGB is thought to result in part from changes in brain-mediated regulation of appetite and food intake. Dopamine (DA) within the dorsal striatum plays an important role in feeding behavior; we therefore hypothesized that RYGB alters DA homeostasis in this subcortical region. In the current study, obese RYGB-operated mice consumed significantly less of a high-fat diet, weighed less by the end of the study, and exhibited lower adiposity than obese sham-operated mice. Interestingly, both RYGB and caloric restriction (pair feeding) resulted in elevated DA and reduced norepinephrine (NE) tissue levels compared with ad libitum fed sham animals. Consequently, the ratio of NE to DA, a measure of DA turnover, was significantly reduced in both of these groups. The RYGB mice additionally exhibited a significant increase in phosphorylation of tyrosine hydroxylase at position Ser31, a key regulatory site of DA synthesis. This increase was associated with augmented expression of extracellular-signal-regulated kinases ERK1/2, the kinase targeting Ser31. Additionally, RYGB has been shown in animal models and humans to improve insulin sensitivity and glycemic control. Curiously, we noted a significant increase in the expression of insulin receptor-β in RYGB animals in striatum (a glucosensing brain region) compared to sham ad libitum fed mice. These data demonstrate that RYGB surgery is associated with altered monoamine homeostasis at the level of the dorsal striatum, thus providing a critical foundation for future studies exploring central mechanisms of weight loss in RYGB.
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Affiliation(s)
- India A. Reddy
- Vanderbilt University Department
of Molecular Physiology
and Biophysics, Vanderbilt Brain Institute, Vanderbilt University Department
of Surgery, and Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - David H. Wasserman
- Vanderbilt University Department
of Molecular Physiology
and Biophysics, Vanderbilt Brain Institute, Vanderbilt University Department
of Surgery, and Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Julio E. Ayala
- Diabetes
and Obesity Research Center, Sanford-Burnham
Medical Research Institute at Lake Nona, Orlando, Florida 32827, United States
| | - Alyssa
H. Hasty
- Vanderbilt University Department
of Molecular Physiology
and Biophysics, Vanderbilt Brain Institute, Vanderbilt University Department
of Surgery, and Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Naji N. Abumrad
- Vanderbilt University Department
of Molecular Physiology
and Biophysics, Vanderbilt Brain Institute, Vanderbilt University Department
of Surgery, and Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Aurelio Galli
- Vanderbilt University Department
of Molecular Physiology
and Biophysics, Vanderbilt Brain Institute, Vanderbilt University Department
of Surgery, and Vanderbilt Mouse Metabolic Phenotyping Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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41
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Magkos F, Tamboli RA, Abumrad NN, Klein S. The battle of the bulge: defense versus offense. Am J Clin Nutr 2014; 100:991-2. [PMID: 25240068 DOI: 10.3945/ajcn.114.096529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Faidon Magkos
- From the Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO (FM and SK), and the Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN (RAT and NNA).
| | - Robyn A Tamboli
- From the Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO (FM and SK), and the Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN (RAT and NNA)
| | - Naji N Abumrad
- From the Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO (FM and SK), and the Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN (RAT and NNA)
| | - Samuel Klein
- From the Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St Louis, MO (FM and SK), and the Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN (RAT and NNA)
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Hung AM, Booker C, Ellis CD, Siew ED, Graves AJ, Shintani A, Abumrad NN, Himmelfarb J, Ikizler TA. Omega-3 fatty acids inhibit the up-regulation of endothelial chemokines in maintenance hemodialysis patients. Nephrol Dial Transplant 2014; 30:266-74. [PMID: 25204316 DOI: 10.1093/ndt/gfu283] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Chronic systemic inflammation is common in patients with chronic kidney disease on dialysis (CKD5D) and has been considered a key mediator of the increased cardiovascular risk in this patient population. In this study, we tested the hypothesis that supplementation of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) will attenuate the systemic inflammatory process in CKD5D patients. METHODS The design was a randomized, double-blinded, placebo controlled pilot trial (NCT00655525). Thirty-eight patients were randomly assigned in a 1 : 1 fashion to receive 2.9 g of eicosapentaenoic acid (C20:5, n-3) plus docosahexaenoic acid (C22:6, n-3) versus placebo for 12 weeks. The primary outcome was change in pro-inflammatory chemokines measured by lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs). Secondary outcomes were changes in systemic inflammatory markers. Analysis of covariance was used to compare percent change from baseline to 12 weeks. RESULTS Thirty-one patients completed 12 weeks and three patients completed 6 weeks of the study. Median age was 52 (interquartile range 45, 60) years, 74% were African-American and 79% were male. Supplementation of ω-3 PUFAs effectively decreased the LPS-induced PBMC expression of RANTES (Regulated upon Activation, Normal T cell Expressed and Secreted) and MCP-1 (Monocyte Chemotactic Protein-1; unadjusted P = 0.04 and 0.06; adjusted for demographics P = 0.02 and 0.05, respectively). There was no significant effect of the intervention on serum inflammatory markers (C-reactive protein, interleukin-6 and procalcitonin). CONCLUSIONS The results of this pilot study suggest that supplementation of ω-3 PUFAs is beneficial in decreasing the levels of endothelial chemokines, RANTES and MCP-1. Studies of larger sample size and longer duration are required to further evaluate effects of ω-3 PUFAs on systemic markers of inflammation, other metabolic parameters and clinical outcomes, particularly cardiovascular outcomes in CKD5D patients.
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Affiliation(s)
- Adriana M Hung
- CSR&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, TN, USA Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Cindy Booker
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Charles D Ellis
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Edward D Siew
- CSR&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, TN, USA Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Amy J Graves
- Division of Biostatistics, Vanderbilt University, Nashville, TN, USA
| | - Ayumi Shintani
- Division of Biostatistics, Vanderbilt University, Nashville, TN, USA
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University, Nashville, TN, USA
| | | | - Talat Alp Ikizler
- CSR&D, Veterans Administration Tennessee Valley Healthcare System, Nashville, TN, USA Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
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43
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Tamboli RA, Breitman I, Marks-Shulman PA, Jabbour K, Melvin W, Williams B, Clements RH, Feurer ID, Abumrad NN. Early weight regain after gastric bypass does not affect insulin sensitivity but is associated with elevated ghrelin. Obesity (Silver Spring) 2014; 22:1617-22. [PMID: 24777992 PMCID: PMC4077938 DOI: 10.1002/oby.20776] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 03/25/2014] [Accepted: 04/14/2014] [Indexed: 01/06/2023]
Abstract
OBJECTIVES We sought to determine: (1) if early weight regain between 1 and 2 years after Roux-en-Y gastric bypass (RYGB) is associated with worsened hepatic and peripheral insulin sensitivity, and (2) if preoperative levels of ghrelin and leptin are associated with early weight regain after RYGB. METHODS Hepatic and peripheral insulin sensitivity and ghrelin and leptin plasma levels were assessed longitudinally in 45 subjects before RYGB and at 1 month, 6 months, 1 year, and 2 years postoperatively. Weight regain was defined as ≥5% increase in body weight between 1 and 2 years after RYGB. RESULTS Weight regain occurred in 33% of subjects, with an average increase in body weight of 10 ± 5% (8.5 ± 3.3 kg). Weight regain was not associated with worsening of peripheral or hepatic insulin sensitivity. Subjects with weight regain after RYGB had higher preoperative and postoperative levels of ghrelin compared to those who maintained or lost weight during this time. Conversely, the trajectories of leptin levels corresponded with the trajectories of fat mass in both groups. CONCLUSIONS Early weight regain after RYGB is not associated with a reversal of improvements in insulin sensitivity. Higher preoperative ghrelin levels might identify patients that are more susceptible to weight regain after RYGB.
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Affiliation(s)
- Robyn A. Tamboli
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
| | - Igal Breitman
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
| | | | - Kareem Jabbour
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
| | - Willie Melvin
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
| | - Brandon Williams
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
| | - Ronald H. Clements
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
| | - Irene D. Feurer
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
- Biostatistics, Vanderbilt University School of Medicine, Nashville TN
| | - Naji N. Abumrad
- Departments of Surgery Vanderbilt University School of Medicine, Nashville TN
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44
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Savage SW, Zald DH, Cowan RL, Volkow ND, Marks-Shulman PA, Kessler RM, Abumrad NN, Dunn JP. Regulation of novelty seeking by midbrain dopamine D2/D3 signaling and ghrelin is altered in obesity. Obesity (Silver Spring) 2014; 22:1452-7. [PMID: 24415718 PMCID: PMC4037348 DOI: 10.1002/oby.20690] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 11/01/2013] [Accepted: 12/19/2013] [Indexed: 12/02/2022]
Abstract
OBJECTIVE To investigate the relationship of novelty seeking traits (NS) with midbrain dopamine (DA) receptors and acyl ghrelin levels (AG) in normal weight (NW) and obese females.NS predict addictive behaviors and are hypothesized to contribute to eating behaviors. In healthy, NS are negatively associated with DA receptors in the substantia nigra (SN). The influence of obesity on the regulation of NS by DA signaling and AG was hypothesized. METHODS PET scanning to measure DA type 2/type 3 receptor (D2/D3R) binding potential (BPND ) in the SN was used. Participants completed Tridimensional Personality Questionnaire-Novelty-Seeking Scale (TPQ-NS) and AG were measured. RESULTS In eight NW and 19 obese (BMI 22 vs 38 kg/m(2) ), TPQ-NS (16 vs 15) and SN D2/D3R BPND (2.48 vs 2.66) were similar, while AG higher (256 vs 60, P < 0.01), respectively. D2/D3R BPND and TPQ-NS had a negative relationship in NW (r = -0.7) but not in obese (P > 0.10). AG and TPQ-NS were positively correlated in NW (r = 0.9) but not in obese (P > 0.10). D2R BPND and AG were negatively correlated in NW (r = -0.8) but positively in obese (r = 0.6). CONCLUSION Obese do not maintain posited regulatory relationships for NS to either midbrain D2/D3R availability or AG present in NW. Also opposite relationships exist for NW and obese between SN D2/D3R availability and AG. The altered regulation of NS in obesity needs to be further explored.
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Affiliation(s)
- Shane W. Savage
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Psychiatry
| | - David H. Zald
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Psychiatry
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Radiology
- Vanderbilt University, Department of Psychology, Nashville, Tennessee
| | - Ronald L. Cowan
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Psychiatry
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Radiology
| | | | | | - Robert M. Kessler
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Radiology
| | - Naji N. Abumrad
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Surgery
| | - Julia P. Dunn
- Vanderbilt University School of Medicine, Nashville, Tennessee, Department of Medicine
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45
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Breitman I, Isbell JM, Saliba J, Jabbour K, Flynn CR, Marks-Shulman PA, Laferrère B, Abumrad NN, Tamboli RA. Effects of proximal gut bypass on glucose tolerance and insulin sensitivity in humans. Diabetes Care 2013; 36:e57. [PMID: 23520381 PMCID: PMC3609508 DOI: 10.2337/dc12-1722] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Igal Breitman
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - James M. Isbell
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jabbar Saliba
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Kareem Jabbour
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Charles Robb Flynn
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | - Blandine Laferrère
- New York Obesity Nutrition Research Center, Columbia University, St. Luke's Roosevelt Hospital Center, New York, New York
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Robyn A. Tamboli
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
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Abstract
Morbid obesity is linked to increased incidences of glucose intolerance, Type 2 diabetes mellitus, cardiovascular diseases, various forms of liver disease, and specific forms of cancer. Treatment of obesity by lifestyle modifications (i.e. changes in diet and exercise) and drug therapy is generally ineffective. Bariatric surgery is currently the most effective means of treating obesity and related disorders. We as well as others have developed surgical procedures for application to genetic mouse models that mimic an array of human bariatric surgical procedures used in the treatment of obesity. The application of bariatric surgery to genetic mouse models will broaden our understanding of the role of the gut in metabolic disease. Models that have been developed include gastric banding, sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB) with a complete exclusion of the stomach, duodenal-jejunal bypass (DJB) and biliopancreatic diversion (BPD). The detailed methods of these procedures are provided.
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Affiliation(s)
- Deng Ping Yin
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, USA ; Department of Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Kelli L Boyd
- Department of Pathology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA ; Department of Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Phillip E Williams
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, USA ; Department of Diabetes Research Training Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, USA ; Department of Diabetes Research Training Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA ; Department of Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA ; Department of Diabetes Research Training Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Rathmacher JA, Fuller JC, Baier SM, Abumrad NN, Angus HF, Sharp RL. Adenosine-5'-triphosphate (ATP) supplementation improves low peak muscle torque and torque fatigue during repeated high intensity exercise sets. J Int Soc Sports Nutr 2012; 9:48. [PMID: 23046855 PMCID: PMC3483284 DOI: 10.1186/1550-2783-9-48] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/03/2012] [Indexed: 01/08/2023] Open
Abstract
Background Intracellular concentrations of adenosine-5’-triphosphate (ATP) are many times greater than extracellular concentrations (1–10 mM versus 10–100 nM, respectively) and cellular release of ATP is tightly controlled. Transient rises in extracellular ATP and its metabolite adenosine have important signaling roles; and acting through purinergic receptors, can increase blood flow and oxygenation of tissues; and act as neurotransmitters. Increased blood flow not only increases substrate availability but may also aid in recovery through removal of metabolic waste products allowing muscles to accomplish more work with less fatigue. The objective of the present study was to determine if supplemental ATP would improve muscle torque, power, work, or fatigue during repeated bouts of high intensity resistance exercise. Methods Sixteen participants (8 male and 8 female; ages: 21–34 years) were enrolled in a double-blinded, placebo-controlled study using a crossover design. The participants received either supplemental ATP (400 mg/d divided into 2 daily doses) or placebo for 15 d. After an overnight fast, participants underwent strength and fatigue testing, consisting of 3 sets of 50 maximal knee extensions performed on a Biodex® leg dynamometer. Results No differences were detected in high peak torque, power, or total work with ATP supplementation; however, low peak torque in set 2 was significantly improved (p < 0.01). Additionally, in set 3, a trend was detected for less torque fatigue with ATP supplementation (p < 0.10). Conclusions Supplementation with 400 mg ATP/d for 15 days tended to reduce muscle fatigue and improved a participant’s ability to maintain a higher force output at the end of an exhaustive exercise bout.
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Affiliation(s)
- John A Rathmacher
- Department of Animal Science, Iowa State University, Ames, IA, 50010, USA.
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Gamboa A, Okamoto L, Arnold A, Raj S, Abumrad NN, Diedrich A, Biaggioni I. Abstract 475: Autonomic Blockade Improves Obesity-Associated Insulin Resistance. Hypertension 2012. [DOI: 10.1161/hyp.60.suppl_1.a475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A hallmark of obesity is the development of insulin resistance. Increased secretion of insulin is an initial compensatory mechanism and is thought to contribute to sympathetic activation in an attempt to restore energy balance. We have previously shown, however, that sympathetic activity has no beneficial effect on resting energy expenditure in obesity. On the contrary, we hypothesize that sympathetic activation contributes to insulin resistance providing a negative feedback loop. To test this hypothesis we determined insulin sensitivity (hyperinsulinemic euglycemic clamp) in obese subjects (30<BMI<40 kg/m2) during intact and during pharmacologically induced autonomic blockade (trimethaphan 4 mg/min IV infusion). Blood pressure was clamped during autonomic blockade by concomitant titrated IV infusion of the NOS inhibitor L-NMMA. Eleven obese subjects (41±3.6 years, 35±0.8 kg/m2, 144±4/90±4 mm Hg) were studied on two separate occasions randomly assigned. Seven were found to be insulin resistance and four to be insulin sensitive (GIR>4.5 mg/kg/min). There were no differences in age, total fat percentage, blood pressure or muscle sympathetic activity between groups. GIR increased during autonomic blockade only among subjects with insulin resistance (2.96±0.54 to 4.03±0.67 mg/kg/min for the intact and blocked days, p=0.018, figure group A). No improvement was seen in the insulin sensitive group (6.08±0.88 to 5.99±1.34 mg/kg/min for the intact and blocked days, p=0.5, Group B). Our results support the concept that sympathetic activation has a detrimental effect on glucose utilization in obesity, and provides the rational to explore it as a therapeutic target.
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Nair S, Al-Hendy A, Tamboli RA, Marks-Shulman PA, Abumrad NN. Increased COMT expression in PCOS biology. Mol Cell Endocrinol 2012; 355:188-9. [PMID: 22342814 DOI: 10.1016/j.mce.2012.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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50
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Dunn JP, Kessler RM, Feurer ID, Volkow ND, Patterson BW, Ansari MS, Li R, Marks-Shulman P, Abumrad NN. Relationship of dopamine type 2 receptor binding potential with fasting neuroendocrine hormones and insulin sensitivity in human obesity. Diabetes Care 2012; 35:1105-11. [PMID: 22432117 PMCID: PMC3329842 DOI: 10.2337/dc11-2250] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Midbrain dopamine (DA) neurons, which are involved with reward and motivation, are modulated by hormones that regulate food intake (insulin, leptin, and acyl ghrelin [AG]). We hypothesized that these hormones are associated with deficits in DA signaling in obesity. RESEARCH DESIGN AND METHODS We assessed the relationships between fasting levels of insulin and leptin, and AG, BMI, and insulin sensitivity index (S(I)) with the availability of central DA type 2 receptor (D2R). We measured D2R availability using positron emission tomography and [(18)F]fallypride (radioligand that competes with endogenous DA) in lean (n = 8) and obese (n = 14) females. Fasting hormones were collected prior to scanning and S(I) was determined by modified oral glucose tolerance test. RESULTS Parametric image analyses revealed associations between each metabolic measure and D2R. The most extensive findings were negative associations of AG with clusters involving the striatum and inferior temporal cortices. Regional regression analyses also found extensive negative relationships between AG and D2R in the caudate, putamen, ventral striatum (VS), amygdala, and temporal lobes. S(I) was negatively associated with D2R in the VS, while insulin was not. In the caudate, BMI and leptin were positively associated with D2R availability. The direction of associations of leptin and AG with D2R availability are consistent with their opposite effects on DA levels (decreasing and increasing, respectively). After adjusting for BMI, AG maintained a significant relationship in the VS. We hypothesize that the increased D2R availability in obese subjects reflects relatively reduced DA levels competing with the radioligand. CONCLUSIONS Our findings provide evidence for an association between the neuroendocrine hormones and DA brain signaling in obese females.
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Affiliation(s)
- Julia P Dunn
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
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