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Debier C, Pirard L, Verhaegen M, Rzucidlo C, Tinant G, Dewulf C, Larondelle Y, Smith DR, Rees JF, Crocker DE. In vitro Lipolysis and Leptin Production of Elephant Seal Blubber Using Precision-Cut Adipose Tissue Slices. Front Physiol 2020; 11:615784. [PMID: 33362587 PMCID: PMC7758477 DOI: 10.3389/fphys.2020.615784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/20/2020] [Indexed: 11/13/2022] Open
Abstract
Adipose tissue plays key roles in energy homeostasis. Understanding its metabolism and regulation is essential to predict the impact of environmental changes on wildlife health, especially in fasting-adapted species. However, in vivo experimental work in wild vertebrates can be challenging. We have developed a novel in vitro approach of precision-cut adipose tissue slices from northern elephant seal (Mirounga angustirostris) as a complementary approach to whole animal models. Blubber biopsies were collected from 14 pups during early and late post-weaning fast (Año Nuevo, CA, United States), precision-cut into 1 mm thick slices and maintained in culture at 37°C for at least 63 h. The slices exhibited an efficient response to ß-adrenergic stimulation, even after 2 days of culture, revealing good in vitro tissue function. The response to lipolytic stimulus did not vary between regions of outer and inner blubber, but was higher at early than at late fast for inner blubber slices. At early fast, lipolysis significantly reduced leptin production. At this stage, inner blubber slices were also more efficient at producing leptin than outer blubber slices, especially in the non-lipolytic condition. This model will aid the study of adipose tissue metabolism and its response to environmental stressors in marine mammals.
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Affiliation(s)
- Cathy Debier
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Laura Pirard
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Marie Verhaegen
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Caroline Rzucidlo
- Department of Biology, Sonoma State University, Rohnert Park, CA, United States
| | - Gilles Tinant
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Clément Dewulf
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Yvan Larondelle
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Donald R Smith
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Jean-François Rees
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA, United States
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Bennett KA, Robinson KJ, Moss SEW, Millward S, Hall AJ. Using blubber explants to investigate adipose function in grey seals: glycolytic, lipolytic and gene expression responses to glucose and hydrocortisone. Sci Rep 2017; 7:7731. [PMID: 28798409 PMCID: PMC5552887 DOI: 10.1038/s41598-017-06037-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/06/2017] [Indexed: 02/02/2023] Open
Abstract
Adipose tissue is fundamental to energy balance, which underpins fitness and survival. Knowledge of adipose regulation in animals that undergo rapid fat deposition and mobilisation aids understanding of their energetic responses to rapid environmental change. Tissue explants can be used to investigate adipose regulation in wildlife species with large fat reserves, when opportunities for organismal experimental work are limited. We investigated glucose removal, lactate, glycerol and NEFA accumulation in media, and metabolic gene expression in blubber explants from wild grey seals. Glycolysis was higher in explants incubated in 25 mM glucose (HG) for 24 h compared to controls (C: 5.5 mM glucose). Adipose-derived lactate likely contributes to high endogenous glucose production in seals. Lipolysis was not stimulated by HG or high hydrocortisone (HC: 500 nM hydrocortisone) and was lower in heavier animals. HC caused NEFA accumulation in media to decrease by ~30% relative to C in females, indicative of increased lipogenesis. Lipolysis was higher in males than females in C and HG conditions. Lower relative abundance of 11-β-hydroxysteroid dehydrogenase 1 mRNA in HG explants suggests glucose involvement in blubber cortisol sensitivity. Our findings can help predict energy balance responses to stress and nutritional state in seals, and highlight the use of explants to study fat tissue function in wildlife.
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Affiliation(s)
- Kimberley A Bennett
- Division of Science, School of Science Engineering and Technology, Abertay University, Bell St, Dundee, DD1 1HG, UK.
- Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK.
| | - Kelly J Robinson
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 8LB, UK
| | - Simon E W Moss
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 8LB, UK
| | - Sebastian Millward
- Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK
| | - Ailsa J Hall
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 8LB, UK
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Interactions Between Oil Substrates and Glucose on Pure Cultures of Ruminal Lipase-Producing Bacteria. Lipids 2013; 48:749-55. [DOI: 10.1007/s11745-013-3793-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 03/05/2013] [Indexed: 10/26/2022]
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Abstract
Diabetes and obesity present a mounting global challenge. Clinicians are increasingly turning to mechanism-based mathematical models for a quantitative definition of physiological defects such as insulin resistance, glucose intolerance and elevated obesity set points, and for predictions of the likely outcomes of therapeutic interventions. However, a very large range of such models is available, making a judicious choice difficult. To better inform this choice, here we present the most important models published to date in a uniform format, discussing similarities and differences in terms of the decisions faced by modellers. We review models for glucostasis, based on the glucose-insulin feedback control loop, and consider extensions to long-term energy balance, dislipidaemia and obesity.
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Chiappe de Cingolani GE. Cyclic AMP, cyclic GMP and glucose utilization by diabetic rat fat cells. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1983; 91:1-8. [PMID: 6192778 DOI: 10.3109/13813458309106472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Fat cells from epididymal adipose tissue from normal and streptozotocin-diabetic rats were studied to determine glucose utilization and cyclic nucleotide levels. Diabetic rat fat cells present a higher cAMP content (P less than 0.05) compared with controls. Addition of insulin decreases within 10-min incubation the cAMP content in both normal and diabetic cells (P less than 0.05). However, the value obtained in the latter remains by 25% higher than that of normal cells not exposed to insulin. No changes in cGMP were detected. Pretreatment of the diabetic animals during two days with propranolol (1 mg kg body wt-1 day-1) induces the decrease to normal levels of the fat cell cAMP content. However, it persists the impairment on glucose utilization observed in fat cells from diabetic animals. It seems that the increase in the intracellular amount of cAMP found in fat cells from diabetic rats is not involved, at least directly, to the impaired glucose utilization found in the diabetic state. Furthermore, through an unknown mechanism, pretreatment with propranolol can induce a drop in fat tissue cAMP toward normal values without normalizing glucose utilization.
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Wong EH, Loten EG. The antilipolytic action of insulin on adrenocorticotrophin-stimulated rat adipocytes. The roles of adenosine 3',5'-monophosphate and the protein kinase dependent on adenosine 3',5'-monophosphate. EUROPEAN JOURNAL OF BIOCHEMISTRY 1981; 115:17-22. [PMID: 6262080 DOI: 10.1111/j.1432-1033.1981.tb06191.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The extent to which a fall in cellular cyclic AMP could account for the antilipolytic action in rat epididymal adipocytes incubated with adrenocorticotrophic hormone was studied. The antilipolytic effect, measured by suppression of glycerol release, was always associated with a decrease in cyclic AMP, but the magnitude of the fall was modified by several factors. For example, it was greater when the cAMP level was high, as when it is at its peak after hormone stimulation, or when cell concentrations are low. Glucose did not modify appreciably the insulin effect on the nucleotide level. The inhibitory effects of insulin on corticotrophin-stimulated lipolysis and cyclic AMP levels were detectable at the concentrations of 1 microU/ml and were biphasic, with maximal effects at 10-100 microU/ml. Protein kinase activity ratio was similarly affected. Activity of cyclic-AMP-dependent protein kinase conformed closely to the level of cyclic AMP. There was no indication that insulin modified the sensitivity of the kinase to cyclic AMP. Insulin did not alter the relationship of cellular cyclic AMP levels to glycerol when adipocytes were incubated with various concentrations of corticotrophin. This was true, irrespective of whether measurements were made when cyclic AMP was on the upward rise after hormone stimulation, or on the decline. The curves obtained with and without insulin were superimposable. It is concluded that the inhibitory action of insulin on lipolysis in fat cells can be fully accounted for by a decrease in cyclic AMP.
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Ruiz G, Sobrino F, Goberna R. In vitro glucose reversal of the inhibitory effect of fasting on epinephrine-induced lipolysis. Biochem Biophys Res Commun 1981; 98:15-20. [PMID: 6260098 DOI: 10.1016/0006-291x(81)91863-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Fain JN, Shepherd RE. Hormonal regulation of lipolysis: role of cyclic nucleotides, adenosine, and free fatty acids. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1979; 111:43-77. [PMID: 218431 DOI: 10.1007/978-1-4757-0734-2_3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Wing DR, Paton WD. An effect of cannabis treatment in vivo on noradrenaline-stimulated lipolysis in rat adipocytes. J Pharm Pharmacol 1978; 30:802-3. [PMID: 32252 DOI: 10.1111/j.2042-7158.1978.tb13400.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Fredholm BB, Belfrage E, Blaschke E. Changes in ATP and cyclic nucleotide levels during sympathetic nerve stimulation in canine subcutaneous adipose tissue in situ. ACTA PHYSIOLOGICA SCANDINAVICA 1977; 99:313-22. [PMID: 192046 DOI: 10.1111/j.1748-1716.1977.tb10384.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Subcutaneous adipose tissue in fed, female dogs was isolated. Biopsies of the tissue (30-150 mg) were taken and rapidly frozen in liquid nitrogen before, during and after nerve stimulation (3-4 Hz). In unstimulated adipose tissue the levels of ATP1 were 74+/-7 nmol/g, of cyclic AMP 90 +/- 12 pmol/g and of cyclic PGMP 18 +/- 3 pmol/g (mean+/-S.E.). During sympathetic nerve stimulation the levels of ATP and cyclic GMP fell by 30 and 50% respectively (p less than 0.01), while the cyclic AMP content increased by 50% (p less than 0.05). After nerve stimulation there was a marked increase in glycerol release, and the levels of all three nucleotides returned to control. The fall in ATP during nerve stimulation was essentially eliminated by prior adrenergic alpha-receptor blockade. It is concluded that 1) sympathetic nerve stimulaton induces a rapid, reversible fall in tissue ATP content, which may be related to hypoxia secondary to the vasoconstriction, and 2) lipolytic responses to sympathetic nerve stimulation in vivo are preceeded by small increases in the tissue cyclic AMP level, and a 3-fold increase in the cyclic AMP/cyclic GMP ratio.
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Birnbaum RS, Goodman HM. Studies on the mechanisms of epinephrine stimulation of lypolysis. Biochim Biophys Acta Gen Subj 1977; 496:292-301. [PMID: 189836 DOI: 10.1016/0304-4165(77)90311-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The time course for epinephrine stimulation of lypolysis, cyclic AMP accumulation and activation of protein kinase was studied in adipose tissue from hypophysectomized rats. Triglyceride breakdown, as assessed by glycerol release, increased rapidly in response to epinephrine, maintained a constant rate as long as the hormone was present, and decreased rapidly to basal values when the hormone was removed. Cyclic AMP accumulation was transient peaking within 3 min of exposure to epinephrine and then declining to levels indistinguishable from basal by 9 min. Protein kinase activity in extracts also peaked at 3 min and thereafter declined to a level approximately 25% greater than resting activity. Peak levels of cyclic AMP, steady state levels of protein kinase activity and the rate of glycerol production were all related in a dose dependent manner to the concentration of epinephrine. These observations suggest that the spike in cyclic AMP levels may be necessary to trigger the activation of lipolysis, but was not sufficient to sustain an accelerated rate of triglyceride breakdown. Continued activation of protein kinase, however, may be essential to sustained lipolysis.
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Schimmel RJ. Adenosine 3',5'cyclic monophosphate in adipose tissue of diabetic rats. Biochim Biophys Acta Gen Subj 1976; 451:363-71. [PMID: 187224 DOI: 10.1016/0304-4165(76)90131-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Normal male rats were made chronically diabetic by injection of alloxan or acutely diabetic by injection of anti-insulin serum. The concentration of cyclic AMP in epididymal adipose tissue was increased approximately 2 1/2-fold 24 h after alloxan administration and up to 7-fold 72 h post-alloxan. Treatment of alloxan-diabetic rats with insulin for 4 h completely suppressed lipolysis but only partially suppressed cyclic AMP levels; 6 h following insulin treatment cyclic AMP levels were normal. When segments of the epididymal fat bodies were incubated in vitro the high cyclic AMP levels were not maintained but instead decreased spontaneously. Addition of insulin to the incubation media decreased lipolysis in tissues of diabetic rats to levels measured in tissues of normal rats and accelerated the decline in cyclic AMP levels but did not return cyclic AMP levels to normal. Rats rendered acutely insulin deficient by injection of anti-insulin serum showed increased plasma glucose and free fatty acid levels and increased adipose tissue free fatty acid, and cyclic AMP levels 30 min following injection of the antiserum. Plasma glucagon levels increased but not until 2 h following anti-insulin serum, thereby excluding the possibility that an increment in plasma glucagon is the primary stimulus for the acceleration of lipolysis in diabetes. These data are consistent with the view that control of adipose tissue cyclic AMP levels in situ is an important physiologic action of insulin.
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Mersmann H, Phinney G, Brown L, Arakelian M. Factors influencing the lipolytic response in swine (Sus domesticus) adipose tissue. ACTA ACUST UNITED AC 1975. [DOI: 10.1016/0306-3623(75)90052-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Schwabe U, Schönhöfer PS, Ebert R. Facilitation by adenosine of the action of insulin on the accumulation of adenosine 3':5'-monophosphate, lipolysis, and glucose oxidation in isolated fat cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1974; 46:537-45. [PMID: 4368715 DOI: 10.1111/j.1432-1033.1974.tb03647.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Knight BL. Adenosine 3',5'-cyclic phosphate, lipolysis and oxygen consumption in brown adipose tissue from newborn rabbits. Effect of cervical sympathectomy and of noradrenalin and theophylline in vitro, and the partial purification of an adenosine 3',5'-cyclic phosphate-dependent protein kinase. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 343:287-96. [PMID: 4365193 DOI: 10.1016/0304-4165(74)90093-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Stein JM, Hales CN. The effect of insulin on 32Pi incorporation into rat fat cell phospholipids. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 337:41-9. [PMID: 4433545 DOI: 10.1016/0005-2760(74)90038-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Smith U. Studies of human adipose tissue in culture. 3. Influence of insulin and medium glucose concentration on cellular metabolism. J Clin Invest 1974; 53:91-8. [PMID: 4808648 PMCID: PMC301442 DOI: 10.1172/jci107564] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Explants of human adipose tissue were maintained in culture for 1 wk in different glucose concentrations with or without the addition of insulin. After this period of time the explants were carefully washed and then subjected to short-term incubations in the same glucose concentration and in the absence of insulin. With this experimental design the influence of long-term exposure to insulin and different glucose concentrations on adipose tissue metabolism could be studied. The results of these studies show that an increase in the glucose concentration of the culture medium enhanced the basal as well as the catecholamine-stimulated lipolysis in the short-term incubations. The presence of insulin in the culture medium enhanced the lipolytic process as well. Analogous results were obtained with the cellular rate of glucose conversion to triglycerides in the short-term incubations. The stimulating effects of insulin and glucose were most pronounced in the larger adipose cells possibly due to their enlarged surface areas. The data suggest that the metabolism of adipose tissue as revealed by short-term studies may be profoundly influenced by the antecedent biochemical environment.
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