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Tranganida A, Hall AJ, Armstrong HC, Moss SEW, Bennett KA. Consequences of in vitro benzyl butyl phthalate exposure for blubber gene expression and insulin-induced Akt activation in juvenile grey seals. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120688. [PMID: 36402420 DOI: 10.1016/j.envpol.2022.120688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/27/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Plastic and plasticiser pollution of marine environments is a growing concern. Although phthalates, one group of plasticisers, are rapidly metabolised by mammals, they are found ubiquitously in humans and have been linked with metabolic disorders and altered adipose function. Phthalates may also present a threat to marine mammals, which need to rapidly accumulate and mobilise their large fat depots. High molecular weight (HMW) phthalates may be most problematic because they can accumulate in adipose. We used blubber explants from juvenile grey seals to examine the effects of overnight exposure to the HMW, adipogenic phthalate, benzyl butyl phthalate (BBzP) on expression of key adipose-specific genes and on phosphorylation of Akt in response to insulin. We found substantial differences in transcript abundance of Pparγ, Insig2, Fasn, Scd, Adipoq and Lep between moult stages, when animals were also experiencing differing mass changes, and between tissue depths, which likely reflect differences in blubber function. Akt abundance was higher in inner compared to outer blubber, consistent with greater metabolic activity in adipose closer to muscle than skin, and its phosphorylation was stimulated by insulin. Transcript abundance of Pparγ and Fasn (and Adipoq in some animals) were increased by short term (30 min) insulin exposure. In addition, overnight in vitro BBzP exposure altered insulin-induced changes in Pparγ (and Adipoq in some animals) transcript abundance, in a tissue depth and moult stage-specific manner. Basal or insulin-induced Akt phosphorylation was not changed. BBzP thus acted rapidly on the transcript abundance of key adipose genes in an Akt-independent manner. Our data suggest phthalate exposure could alter seal blubber development or function, although the whole animal consequences of these changes are not yet understood. Knowledge of typical phthalate exposures and toxicokinetics would help to contextualise these findings in terms of phthalate-induced metabolic disruption risk and consequences for marine mammal health.
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Affiliation(s)
- Alexandra Tranganida
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, KY16 8LB, UK; Division of Health Science, School of Applied Sciences, Abertay University, Dundee, DD1 1HG, UK
| | - Ailsa J Hall
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, KY16 8LB, UK
| | - Holly C Armstrong
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, KY16 8LB, UK; Division of Health Science, School of Applied Sciences, Abertay University, Dundee, DD1 1HG, UK; School of Psychology and Neuroscience, University of St Andrews, KY16 9JP, UK
| | - Simon E W Moss
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, KY16 8LB, UK
| | - Kimberley A Bennett
- Division of Health Science, School of Applied Sciences, Abertay University, Dundee, DD1 1HG, UK.
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Palato LM, Pilcher S, Oakes A, Lamba A, Torres J, Ledesma Monjaraz LI, Munoz C, Njoo E, Rinauro DJ, Menefee KA, Tun A, Jauregui BL, Shapiro S, Nossiff OH, Olivares E, Chang K, Nguyen V, Nogaj LA, Moffet DA. Amyloidogenicity of naturally occurring full-length animal IAPP variants. J Pept Sci 2019; 25:e3199. [PMID: 31231935 DOI: 10.1002/psc.3199] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 12/15/2022]
Abstract
The aggregation of the 37-amino acid polypeptide human islet amyloid polypeptide (hIAPP), as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of human pancreatic β-islet cells in type 2 diabetes. hIAPP is considered to be one of the most amyloidogenic proteins known. The quick aggregation of hIAPP leads to the formation of toxic species, such as oligomers and fibers, that damage mammalian cells (both human and rat pancreatic cells). Whether this toxicity is necessary for the progression of type 2 diabetes or merely a side effect of the disease remains unclear. If hIAPP aggregation into toxic amyloid is on-path for developing type 2 diabetes in humans, islet amyloid polypeptide (IAPP) aggregation would likely need to play a similar role within other organisms known to develop the disease. In this work, we compared the aggregation potential and cellular toxicity of full-length IAPP from several diabetic and nondiabetic organisms whose aggregation propensities had not yet been determined for full-length IAPP.
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Affiliation(s)
- Larry M Palato
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Shannon Pilcher
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Alissa Oakes
- Department of Biology, Mount Saint Mary's University, Los Angeles, CA
| | - Arleen Lamba
- Department of Biology, Mount Saint Mary's University, Los Angeles, CA
| | - Jaris Torres
- Department of Biology, Mount Saint Mary's University, Los Angeles, CA
| | | | - Crystabel Munoz
- Department of Biology, Mount Saint Mary's University, Los Angeles, CA
| | - Edward Njoo
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Dillon J Rinauro
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | | | - Angela Tun
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Betssy L Jauregui
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Sarah Shapiro
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Olivia H Nossiff
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Eileen Olivares
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Kevin Chang
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Viviane Nguyen
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
| | - Luiza A Nogaj
- Department of Biology, Mount Saint Mary's University, Los Angeles, CA
| | - David A Moffet
- Department of Chemistry and Biochemistry, Loyola Marymount University, Los Angeles, CA
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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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Crocker DE, Wenzel BK, Champagne CD, Houser DS. Adult male northern elephant seals maintain high rates of glucose production during extended breeding fasts. J Comp Physiol B 2017; 187:1183-1192. [DOI: 10.1007/s00360-017-1098-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/15/2017] [Accepted: 04/06/2017] [Indexed: 10/19/2022]
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Bennett KA, Turner LM, Millward S, Moss SEW, Hall AJ. Obtaining accurate glucose measurements from wild animals under field conditions: comparing a hand held glucometer with a standard laboratory technique in grey seals. CONSERVATION PHYSIOLOGY 2017; 5:cox013. [PMID: 28413683 PMCID: PMC5386009 DOI: 10.1093/conphys/cox013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/18/2017] [Accepted: 01/30/2017] [Indexed: 05/30/2023]
Abstract
Glucose is an important metabolic fuel and circulating levels are tightly regulated in most mammals, but can drop when body fuel reserves become critically low. Glucose is mobilized rapidly from liver and muscle during stress in response to increased circulating cortisol. Blood glucose levels can thus be of value in conservation as an indicator of nutritional status and may be a useful, rapid assessment marker for acute or chronic stress. However, seals show unusual glucose regulation: circulating levels are high and insulin sensitivity is limited. Accurate blood glucose measurement is therefore vital to enable meaningful health and physiological assessments in captive, wild or rehabilitated seals and to explore its utility as a marker of conservation relevance in these animals. Point-of-care devices are simple, portable, relatively cheap and use less blood compared with traditional sampling approaches, making them useful in conservation-related monitoring. We investigated the accuracy of a hand-held glucometer for 'instant' field measurement of blood glucose, compared with blood drawing followed by laboratory testing, in wild grey seals (Halichoerus grypus), a species used as an indicator for Good Environmental Status in European waters. The glucometer showed high precision, but low accuracy, relative to laboratory measurements, and was least accurate at extreme values. It did not provide a reliable alternative to plasma analysis. Poor correlation between methods may be due to suboptimal field conditions, greater and more variable haematocrit, faster erythrocyte settling rate and/or lipaemia in seals. Glucometers must therefore be rigorously tested before use in new species and demographic groups. Sampling, processing and glucose determination methods have major implications for conclusions regarding glucose regulation, and health assessment in seals generally, which is important in species of conservation concern and in development of circulating glucose as a marker of stress or nutritional state for use in management and monitoring.
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Affiliation(s)
- Kimberley A. Bennett
- Division of Science, School of Science, Engineering and Technology, Abertay University, DundeeDD1 1HG, UK
- Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, PlymouthPL4 8AA, UK
| | - Lucy M. Turner
- Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, PlymouthPL4 8AA, UK
| | - Sebastian Millward
- Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, PlymouthPL4 8AA, UK
| | - Simon E. W. Moss
- NERC Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, FifeKY16 8LB, UK
| | - Ailsa J. Hall
- NERC Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, FifeKY16 8LB, UK
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Bennett KA, Hughes J, Stamatas S, Brand S, Foster NL, Moss SEW, Pomeroy PP. Adiponectin and Insulin in Gray Seals during Suckling and Fasting: Relationship with Nutritional State and Body Mass during Nursing in Mothers and Pups. Physiol Biochem Zool 2015; 88:295-310. [PMID: 25860828 DOI: 10.1086/680862] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Animals that fast during breeding and/or development, such as phocids, must regulate energy balance carefully to maximize reproductive fitness and survival probability. Adiponectin, produced by adipose tissue, contributes to metabolic regulation by modulating sensitivity to insulin, increasing fatty acid oxidation by liver and muscle, and promoting adipogenesis and lipid storage in fat tissue. We tested the hypotheses that (1) circulating adiponectin, insulin, or relative adiponectin gene expression is related to nutritional state, body mass, and mass gain in wild gray seal pups; (2) plasma adiponectin or insulin is related to maternal lactation duration, body mass, percentage milk fat, or free fatty acid (FFA) concentration; and (3) plasma adiponectin and insulin are correlated with circulating FFA in females and pups. In pups, plasma adiponectin decreased during suckling (linear mixed-effects model [LME]: T = 4.49; P < 0.001) and the early postweaning fast (LME: T = 3.39; P = 0.004). In contrast, their blubber adiponectin gene expression was higher during the early postweaning fast than early in suckling (LME: T = 2.11; P = 0.046). Insulin levels were significantly higher in early (LME: T = 3.52; P = 0.004) and late (LME: T = 6.99; P < 0.001) suckling than in fasting and, given the effect of nutritional state, were also positively related to body mass (LME: T = 3.58; P = 0.004). Adiponectin and insulin levels did not change during lactation and were unrelated to milk FFA or percentage milk fat in adult females. Our data suggest that adiponectin, in conjunction with insulin, may facilitate fat storage in seals and is likely to be particularly important in the development of blubber reserves in pups.
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Affiliation(s)
- K A Bennett
- Marine Biology and Ecology Research Centre, School of Marine Science and Engineering, Plymouth University, Portland Square, Drake Circus, Plymouth, Devon PL4 8AA, United Kingdom; 2Natural Environment Research Council Sea Mammal Research Unit, Gatty Marine Laboratories, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife KY16 8LB, United Kingdom
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Czech-Damal N, Geiseler S, Hoff M, Schliep R, Ramirez JM, Folkow L, Burmester T. The role of glycogen, glucose and lactate in neuronal activity during hypoxia in the hooded seal (Cystophora cristata) brain. Neuroscience 2014; 275:374-83. [DOI: 10.1016/j.neuroscience.2014.06.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 06/11/2014] [Accepted: 06/12/2014] [Indexed: 10/25/2022]
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Bennett KA, MacMillan IS, Hammill M, Currie S. HSP70 Abundance and Antioxidant Capacity in Feeding and Fasting Gray Seal Pups: Suckling Is Associated with Higher Levels of Key Cellular Defenses. Physiol Biochem Zool 2014; 87:663-76. [DOI: 10.1086/676935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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