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Warfel JD, Elks CM, Bayless DS, Vandanmagsar B, Stone AC, Velasquez SE, Olivares-Nazar P, Noland RC, Ghosh S, Zhang J, Mynatt RL. Rats lacking Ucp1 present a novel translational tool for the investigation of thermogenic adaptation during cold challenge. Acta Physiol (Oxf) 2023; 238:e13935. [PMID: 36650072 DOI: 10.1111/apha.13935] [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: 07/05/2022] [Revised: 01/06/2023] [Accepted: 01/10/2023] [Indexed: 01/19/2023]
Abstract
AIM Valuable studies have tested the role of UCP1 on body temperature maintenance in mice, and we sought to knockout Ucp1 in rats (Ucp1-/- ) to provide insight into thermogenic mechanisms in larger mammals. METHODS We used CRISPR/Cas9 technology to create Ucp1-/- rats. Body weight and adiposity were measured, and rats were subjected to indirect calorimetry. Rats were maintained at room temperature or exposed to 4°C for either 24 h or 14 days. Analyses of brown and white adipose tissue and skeletal muscle were conducted via histology, western blot comparison of oxidative phosphorylation proteins, and qPCR to compare mitochondrial DNA levels and mRNA expression profiles. RNA-seq was performed in skeletal muscle. RESULTS Ucp1-/- rats withstood 4°C for 14 days, but core temperature steadily declined. All rats lost body weight after 14 days at 4°C, but controls increased food intake more robustly than Ucp1-/- rats. Brown adipose tissue showed signs of decreased activity in Ucp1-/- rats, while mitochondrial lipid metabolism markers in white adipose tissue and skeletal muscle were increased. Ucp1-/- rats displayed more visible shivering and energy expenditure than controls at 4°C. Skeletal muscle transcriptomics showed more differences between genotypes at 23°C than at 4°C. CONCLUSION Room temperature presented sufficient cold stress to rats lacking UCP1 to activate compensatory thermogenic mechanisms in skeletal muscle, which were only activated in control rats following exposure to 4°C. These results provide novel insight into thermogenic responses to UCP1 deficiency; and highlight Ucp1-/- rats as an attractive translational model for the study of thermogenesis.
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Affiliation(s)
- Jaycob D Warfel
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Carrie M Elks
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - David S Bayless
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Bolormaa Vandanmagsar
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Allison C Stone
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Samuel E Velasquez
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Paola Olivares-Nazar
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Robert C Noland
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Sujoy Ghosh
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
- Computational Biology and Program in Cardiovascular and Metabolic Disorders, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Jingying Zhang
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Randall L Mynatt
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
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Mynatt RL, Noland RC, Elks CM, Vandanmagsar B, Bayless DS, Stone AC, Ghosh S, Ravussin E, Warfel JD. Corrigendum to "The RNA binding protein HuR influences skeletal muscle metabolic flexibility in rodents and humans" [Metab. 97 (2019) 40-49]. Metabolism 2023; 138:155345. [PMID: 36410080 PMCID: PMC9847368 DOI: 10.1016/j.metabol.2022.155345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Randall L Mynatt
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Robert C Noland
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Carrie M Elks
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Bolormaa Vandanmagsar
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - David S Bayless
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Allison C Stone
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Sujoy Ghosh
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America; Computational Biology and Program in Cardiovascular and Metabolic Disorders, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Eric Ravussin
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Jaycob D Warfel
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America.
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Ghosh S, Wicks SE, Vandanmagsar B, Mendoza TM, Bayless DS, Salbaum JM, Dearth SP, Campagna SR, Mynatt RL, Noland RC. Extensive metabolic remodeling after limiting mitochondrial lipid burden is consistent with an improved metabolic health profile. J Biol Chem 2019; 294:12313-12327. [PMID: 31097541 PMCID: PMC6699851 DOI: 10.1074/jbc.ra118.006074] [Citation(s) in RCA: 16] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 04/29/2019] [Indexed: 01/19/2023] Open
Abstract
Mitochondrial lipid overload in skeletal muscle contributes to insulin resistance, and strategies limiting this lipid pressure improve glucose homeostasis; however, comprehensive cellular adaptations that occur in response to such an intervention have not been reported. Herein, mice with skeletal muscle-specific deletion of carnitine palmitoyltransferase 1b (Cpt1bM-/-), which limits mitochondrial lipid entry, were fed a moderate fat (25%) diet, and samples were subjected to a multimodal analysis merging transcriptomics, proteomics, and nontargeted metabolomics to characterize the coordinated multilevel cellular responses that occur when mitochondrial lipid burden is mitigated. Limiting mitochondrial fat entry predictably improves glucose homeostasis; however, remodeling of glucose metabolism pathways pales compared with adaptations in amino acid and lipid metabolism pathways, shifts in nucleotide metabolites, and biogenesis of mitochondria and peroxisomes. Despite impaired fat utilization, Cpt1bM-/- mice have increased acetyl-CoA (14-fold) and NADH (2-fold), indicating metabolic shifts yield sufficient precursors to meet energy demand; however, this does not translate to enhance energy status as Cpt1bM-/- mice have low ATP and high AMP levels, signifying energy deficit. Comparative analysis of transcriptomic data with disease-associated gene-sets not only predicted reduced risk of glucose metabolism disorders but was also consistent with lower risk for hepatic steatosis, cardiac hypertrophy, and premature death. Collectively, these results suggest induction of metabolic inefficiency under conditions of energy surfeit likely contributes to improvements in metabolic health when mitochondrial lipid burden is mitigated. Moreover, the breadth of disease states to which mechanisms induced by muscle-specific Cpt1b inhibition may mediate health benefits could be more extensive than previously predicted.
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Affiliation(s)
- Sujoy Ghosh
- Laboratory of Computational Biology, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808; Program in Cardiovascular and Metabolic Disorders and Center for Computational Biology, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
| | - Shawna E Wicks
- Talaria Antibodies, Inc., Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808; Gene Nutrient Interactions Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Bolormaa Vandanmagsar
- Gene Nutrient Interactions Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Tamra M Mendoza
- Gene Nutrient Interactions Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - David S Bayless
- Gene Nutrient Interactions Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - J Michael Salbaum
- Genomics Core Facility, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Stephen P Dearth
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996
| | - Shawn R Campagna
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996
| | - Randall L Mynatt
- Gene Nutrient Interactions Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808; Transgenic Core Facility, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Robert C Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808.
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Mynatt RL, Noland RC, Elks CM, Vandanmagsar B, Bayless DS, Stone AC, Ghosh S, Ravussin E, Warfel JD. The RNA binding protein HuR influences skeletal muscle metabolic flexibility in rodents and humans. Metabolism 2019; 97:40-49. [PMID: 31129047 PMCID: PMC6624076 DOI: 10.1016/j.metabol.2019.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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: 03/06/2019] [Revised: 05/04/2019] [Accepted: 05/21/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND Metabolic flexibility can be assessed by changes in respiratory exchange ratio (RER) following feeding. Though metabolic flexibility (difference in RER between fasted and fed state) is often impaired in individuals with obesity or type 2 diabetes, the cellular processes contributing to this impairment are unclear. MATERIALS AND METHODS From several clinical studies we identified the 16 most and 14 least metabolically flexible male and female subjects out of >100 participants based on differences between 24-hour and sleep RER measured in a whole-room indirect calorimeter. Global skeletal muscle gene expression profiles revealed that, in metabolically flexible subjects, transcripts regulated by the RNA binding protein, HuR, are enriched. We generated and characterized mice with a skeletal muscle-specific knockout of the HuR encoding gene, Elavl1 (HuRm-/-). RESULTS Male, but not female, HuRm-/- mice exhibit metabolic inflexibility, with mild obesity, impaired glucose tolerance, impaired fat oxidation and decreased in vitro palmitate oxidation compared to HuRfl/fl littermates. Expression levels of genes involved in mitochondrial fatty acid oxidation and oxidative phosphorylation are decreased in both mouse and human muscle when HuR is inhibited. CONCLUSIONS HuR inhibition results in impaired metabolic flexibility and decreased lipid oxidation, suggesting a role for HuR as an important regulator of skeletal muscle metabolism.
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Affiliation(s)
- Randall L Mynatt
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Robert C Noland
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Carrie M Elks
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Bolormaa Vandanmagsar
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - David S Bayless
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Allison C Stone
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Sujoy Ghosh
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America; Computational Biology and Program in Cardiovascular and Metabolic Disorders, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Eric Ravussin
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Jaycob D Warfel
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America.
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Vieira-Potter VJ, Lee S, Bayless DS, Scroggins RJ, Welly RJ, Fleming NJ, Smith TN, Meers GM, Hill MA, Rector RS, Padilla J. Disconnect between adipose tissue inflammation and cardiometabolic dysfunction in Ossabaw pigs. Obesity (Silver Spring) 2015; 23:2421-9. [PMID: 26524201 PMCID: PMC4701582 DOI: 10.1002/oby.21252] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [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: 05/17/2015] [Revised: 07/15/2015] [Accepted: 07/16/2015] [Indexed: 02/01/2023]
Abstract
OBJECTIVE The Ossabaw pig is emerging as an attractive model of human cardiometabolic disease because of its size and susceptibility to atherosclerosis, among other characteristics. The relationship between adipose tissue inflammation and metabolic dysfunction in this model was investigated here. METHODS Young female Ossabaw pigs were fed a Western-style high-fat diet (HFD) (n = 4) or control low-fat diet (LFD) (n = 4) for a period of 9 months and compared for cardiometabolic outcomes and adipose tissue inflammation. RESULTS The HFD-fed "OBESE" pigs were 2.5 times heavier (P < 0.001) than LFD-fed "LEAN" pigs and developed severe obesity. HFD feeding caused pronounced dyslipidemia, hypertension, and insulin resistance (systemic and adipose), as well as induction of inflammatory genes, impairments in vasomotor reactivity to insulin, and atherosclerosis in the coronary arteries. Remarkably, visceral, subcutaneous, and perivascular adipose tissue inflammation (via FACS analysis and RT-PCR) was not increased in OBESE pigs, nor were circulating inflammatory cytokines. CONCLUSIONS These findings reveal a disconnect between adipose tissue inflammation and cardiometabolic dysfunction induced by Western diet feeding in the Ossabaw pig model.
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Affiliation(s)
| | - Sewon Lee
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO
- Division of Sport Science & Sport Science Institute, Incheon National University, Incheon, South Korea
| | - David S. Bayless
- Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
| | | | - Rebecca J. Welly
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
| | | | - Thomas N. Smith
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
| | - Grace M. Meers
- Research Service, Harry S Truman Memorial VA Medical Center, Columbia, MO
| | - Michael A. Hill
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO
- Research Service, Harry S Truman Memorial VA Medical Center, Columbia, MO
| | - R. Scott Rector
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
- Research Service, Harry S Truman Memorial VA Medical Center, Columbia, MO
- Medicine-Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO
| | - Jaume Padilla
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO
- Child Health, University of Missouri, Columbia, MO
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6
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Crissey JM, Jenkins NT, Duncan KA, Thorne PK, Bayless DS, Vieira-Potter VJ, Scott Rector R, Thyfault JP, Harold Laughlin M, Padilla J. Adipose Tissue and Vascular Phenotypic Modulation by Voluntary Physical Activity and Dietary Restriction in Obese Insulin Resistant OLETF Rats. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000495621.27938.ed] [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: 11/21/2022]
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Crissey JM, Jenkins NT, Lansford KA, Thorne PK, Bayless DS, Vieira-Potter VJ, Rector RS, Thyfault JP, Laughlin MH, Padilla J. Adipose tissue and vascular phenotypic modulation by voluntary physical activity and dietary restriction in obese insulin-resistant OLETF rats. Am J Physiol Regul Integr Comp Physiol 2014; 306:R596-606. [PMID: 24523340 DOI: 10.1152/ajpregu.00493.2013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Adipose tissue (AT)-derived cytokines are proposed to contribute to obesity-associated vascular insulin resistance. We tested the hypothesis that voluntary physical activity and diet restriction-induced maintenance of body weight would both result in decreased AT inflammation and concomitant improvements in insulin-stimulated vascular relaxation in the hyperphagic, obese Otsuka Long-Evans Tokushima fatty (OLETF) rat. Rats (aged 12 wk) were randomly assigned to sedentary (SED; n = 10), wheel running (WR; n = 10), or diet restriction (DR; n = 10; fed 70% of SED) for 8 wk. WR and DR rats exhibited markedly lower adiposity (7.1 ± 0.4 and 15.7 ± 1.1% body fat, respectively) relative to SED (27 ± 1.2% body fat), as well as improved blood lipid profiles and systemic markers of insulin resistance. Reduced adiposity in both WR and DR was associated with decreased AT mRNA expression of inflammatory genes (e.g., MCP-1, TNF-α, and IL-6) and markers of immune cell infiltration (e.g., CD8, CD11c, and F4/80). The extent of these effects were most pronounced in visceral AT compared with subcutaneous and periaortic AT. Markers of inflammation in brown AT were upregulated with WR but not DR. In periaortic AT, WR- and DR-induced reductions in expression and secretion of cytokines were accompanied with a more atheroprotective gene expression profile in the adjacent aortic wall. WR, but not DR, resulted in greater insulin-stimulated relaxation in the aorta; an effect that was, in part, mediated by a decrease in insulin-induced endothelin-1 activation in WR aorta. Collectively, we show in OLETF rats that lower adiposity leads to less AT and aortic inflammation, as well as an exercise-specific improvement in insulin-stimulated vasorelaxation.
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Padilla J, Jenkins NT, Thorne PK, Lansford KA, Fleming NJ, Bayless DS, Sheldon RD, Rector RS, Laughlin MH. Differential regulation of adipose tissue and vascular inflammatory gene expression by chronic systemic inhibition of NOS in lean and obese rats. Physiol Rep 2014; 2:e00225. [PMID: 24744894 PMCID: PMC3966247 DOI: 10.1002/phy2.225] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [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: 01/06/2014] [Accepted: 01/07/2014] [Indexed: 12/22/2022] Open
Abstract
We tested the hypothesis that a decrease in bioavailability of nitric oxide (NO) would result in
increased adipose tissue (AT) inflammation. In particular, we utilized the obese Otsuka Long Evans
Tokushima Fatty rat model (n = 20) and lean Long Evans Tokushima Otsuka
counterparts (n = 20) to determine the extent to which chronic inhibition of
NO synthase (NOS) with
Nω‐nitro‐l‐arginine methyl
ester (L‐NAME) treatment (for 4 weeks) upregulates expression of inflammatory genes and
markers of immune cell infiltration in retroperitoneal white AT, subscapular brown AT, periaortic AT
as well as in its contiguous aorta free of perivascular AT. As expected, relative to lean rats
(% body fat = 13.5 ± 0.7), obese rats (% body fat = 27.2 ±
0.8) were hyperlipidemic (total cholesterol 77.0 ± 2.1 vs. 101.0 ± 3.3 mg/dL),
hyperleptinemic (5.3 ± 0.9 vs. 191.9 ± 59.9 pg/mL), and
insulin‐resistant (higher HOMA IR index [3.9 ± 0.8 vs. 25.2 ± 4.1]). Obese rats
also exhibited increased expression of proinflammatory genes in perivascular, visceral, and brown
ATs. L‐NAME treatment produced a small but statistically significant decrease in percent body
fat (24.6 ± 0.9 vs. 27.2 ± 0.8%) and HOMA IR index (16.9 ± 2.3 vs. 25.2
± 4.1) in obese rats. Further, contrary to our hypothesis, we found that expression of
inflammatory genes in all AT depots examined were generally unaltered with L‐NAME treatment
in both lean and obese rats. This was in contrast with the observation that L‐NAME produced a
significant upregulation of inflammatory and proatherogenic genes in the aorta. Collectively, these
findings suggest that chronic NOS inhibition alters transcriptional regulation of proinflammatory
genes to a greater extent in the aortic wall compared to its adjacent perivascular AT, or visceral
white and subscapular brown AT depots. We tested the hypothesis that a decrease in bioavailability of nitric oxide (NO) would result in
increased adipose tissue (AT) inflammation. Our findings suggest that chronic NOS inhibition alters
transcriptional regulation of proinflammatory genes to a greater extent in the aortic wall compared
to its adjacent perivascular AT, or visceral white and subscapular brown AT depots.
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Affiliation(s)
- Jaume Padilla
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri ; Child Health, University of Missouri, Columbia, Missouri ; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | | | - Pamela K Thorne
- Biomedical Sciences, University of Missouri, Columbia, Missouri
| | | | | | - David S Bayless
- Biomedical Sciences, University of Missouri, Columbia, Missouri ; Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Ryan D Sheldon
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri ; Harry S Truman Memorial VA Medical Center, Columbia, Missouri
| | - R Scott Rector
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri ; Harry S Truman Memorial VA Medical Center, Columbia, Missouri ; Internal Medicine-Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri
| | - M Harold Laughlin
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri ; Biomedical Sciences, University of Missouri, Columbia, Missouri ; Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
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Roberts MD, Bayless DS, Company JM, Jenkins NT, Padilla J, Childs TE, Martin JS, Dalbo VJ, Booth FW, Rector RS, Laughlin MH. Elevated skeletal muscle irisin precursor FNDC5 mRNA in obese OLETF rats. Metabolism 2013; 62:1052-6. [PMID: 23498898 PMCID: PMC3688677 DOI: 10.1016/j.metabol.2013.02.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [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: 10/25/2012] [Revised: 01/31/2013] [Accepted: 02/01/2013] [Indexed: 02/04/2023]
Abstract
OBJECTIVE There is debate as to whether fibronectin type III domain containing 5 (FNDC5) and its protein product irisin are therapeutic targets for obesity-associated maladies. Thus, we sought to examine FNDC5 mRNA within skeletal muscle of obese/diabetic-prone Otsuka Long-Evans Tokushima Fatty (OLETF) rats versus lean/healthy Long Evans Tokushima Otsuka (LETO) rats. We hypothesized that FNDC5 expression would be greater in obese (OLETF) versus lean (LETO) animals. MATERIALS/METHODS Triceps muscle of 30-32week old OLETF and LETO rats were assayed for FNDC5 and PGC1α mRNA levels. Body composition and circulating biomarkers of the OLETF and LETO rats were also correlated with skeletal muscle FNDC5 mRNA expression patterns in order to examine potential relationships that may exist. RESULTS OLETF rats exhibited twice the amount of triceps FNDC5 mRNA compared to LETO rats (p<0.01). Significant positive correlations existed between triceps muscle FNDC5 mRNA expression patterns versus fat mass (r=0.70, p=0.008), as well as plasma leptin (r=0.82, p<0.001). PGC1α mRNA levels were also highly correlated with FNDC5 mRNA (r=0.85, p<0.001). In subsequent culture experiments, low and high physiological doses of leptin had no effect on PGC1α mRNA or FNDC5 mRNA levels in C2C12 myotubes. Paradoxically, circulating irisin concentrations tended to be higher in a second cohort of LETO versus OLETF rats (p=0.085). CONCLUSION These results reveal a positive association between total body adiposity and skeletal muscle FNDC5 gene expression. Of interest, circulating irisin levels tended to be lower in OLETF rats. Further research is needed to examine whether other adipose tissue-derived factors up-regulate FNDC5 transcription and/or inhibit irisin biosynthesis from FNDC5.
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Affiliation(s)
- Michael D. Roberts
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
| | - David S. Bayless
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO USA
| | - Joseph M. Company
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
| | - Nathan T. Jenkins
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
| | - Jaume Padilla
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
| | - Thomas E. Childs
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
| | - Jeffrey S. Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
| | - Vincent J. Dalbo
- School of Medical and Applied Sciences, Institute of Health and Social Science Research, Central Queensland University, Rockhampton, Queensland AU
| | - Frank W. Booth
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO USA
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO USA
| | - R. Scott Rector
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO USA
- Internal Medicine – Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO USA
- Harry S Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - M. Harold Laughlin
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO USA
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO USA
- Address all correspondence to: M. Harold Laughlin, Ph.D, Department of Biomedical Sciences, University of Missouri-Columbia, 1600 E Rollins St, room E102, Columbia, MO, USA 65211, Phone: 573-882-7011, )
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Jenkins NT, Padilla J, Arce-Esquivel AA, Bayless DS, Martin JS, Leidy HJ, Booth FW, Rector RS, Laughlin MH. Effects of endurance exercise training, metformin, and their combination on adipose tissue leptin and IL-10 secretion in OLETF rats. J Appl Physiol (1985) 2012; 113:1873-83. [PMID: 23019312 DOI: 10.1152/japplphysiol.00936.2012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Adipose tissue inflammation plays a role in cardiovascular (CV) and metabolic diseases associated with obesity, insulin resistance, and type 2 diabetes mellitus (T2DM). The interactive effects of exercise training and metformin, two first-line T2DM treatments, on adipose tissue inflammation are not known. Using the hyperphagic, obese, insulin-resistant Otsuka Long-Evans Tokushima Fatty (OLETF) rat model, we tested the hypothesis that treadmill training, metformin, or a combination of these reduces the secretion of proinflammatory cytokines from adipose tissue. Compared with Long-Evans Tokushima Otsuka (LETO) control rats (L-Sed), sedentary OLETF (O-Sed) animals secreted significantly greater amounts of leptin from retroperitoneal adipose tissue. Conversely, secretion of interleukin (IL)-10 by O-Sed adipose tissue was lower than that in L-Sed animals. Examination of leptin and IL-10 secretion from adipose tissue in OLETF groups treated with endurance exercise training (O-EndEx), metformin treatment (O-Met), and a combination of these (O-E+M) from 20 to 32 wk of age indicated that 1) leptin secretion from adipose tissue was reduced in O-Met and O-E+M, but not O-EndEx animals; 2) adipose tissue IL-10 secretion was increased in O-EndEx and O-E+M but not in O-Met animals; and 3) only the combined treatment (O-E+M) displayed both a reduction in leptin secretion and an increase in IL-10 secretion. Leptin and IL-10 concentrations in adipose tissue-conditioned buffers were correlated with their plasma concentrations, adipocyte diameters, and total adiposity. Overall, this study indicates that exercise training and metformin have additive influences on adipose tissue secretion and plasma concentrations of leptin and IL-10.
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Affiliation(s)
- Nathan T Jenkins
- Department of 1Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA.
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